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I BAYSTATE ENVIRONMENTAL CONSULTANTS I N: I DRAFT FINAL REPORT I I I DIAGNOSTIC/FEASIBILITY STUDY FOR THE MANAGEMENT OF I LOST LAKE / KNOPF'S POND I
PREPARED FOR THE I TOWN OF GROTON AND THE I MASSACHUSETTS DIVISION OF WATER POLLUTION CONTROL I UNDER MGL CHAP. 628 I MASSACHUSETTS CLEAN LAKES PROGRAM I I BAYSTATE ENVIRONMENTAL CONSULTANTS, INC I 296 NORTH MAIN STREET I EAST LONGMEADOW, MASSACHUSETTS I
I DRAFT REPORT I APRIL 1989 I I I
I I PROJECT SUMMARY
I Lost Lake / Knopp's Pond and its watershed was the subject of a Phase I Diagnostic/Feasibility Study, conducted under the M.G.L. Chapter 628 Clean Lakes Program. This study was performed I by the firm of Baystate Environmental Consultants, Inc. for the Town of Groton. The Diagnostic/Feasibility study's primary goals were to determine the historic and present water quality conditions in the lake, identify the major sources of nutrient I loadings in the watershed and provide appropriate recommendations for improvement of the water resource. The major problems of concern were decreasing water quality and recreational impairment I caused by dense beds of aquatic macrophytes. The period of sampling and data collection was from October 1987 to September I 1988. The results of the Diagnostic portion of the study indicated that Lost Lake / Knopp's Pond is a mesotrophic lake verging on eutrophic status, which is impacted by its increasing I residential watershed. Phosphorus was the most important limiting nutrient for primary production in Lost Lake / Knopp's Pond. Phosphorus was found to be entering f rom ^a-1-^ a number of I sources^x^ The three most important being Martin' sTond Brook (46%), groundwater (24%) and and unnamed tributary (17%). The biological community which exists under these conditions contains a diverse but overabundant macrophyte population and an average I to fair fish community, overpopulated by panfish. /• - Feasibility portion of the studv^onsidered and I eliminated lake management options not appropriate or feasible for Lost Lake / Knopp's Pond. The recommended options were construction of a pond underdrain to allow controlled drawdowns I for macrophyte control, application of benthic (bottom) barriers to provide localized relief from macrophytes at the town beach and private residences and a comprehensive education program on watershed management. This education program stresses I improvement of surface water quality through adoption of best management practices and improvement of local residents' environmental awareness. Protection of groundwater through I enforcement of local ordinances and increased maintenance and pumping of abutter' s septic systems are also included. Implementation of all the management options would reduce the I phosphorus budge^fby 19 to 29%. A detailed description and cost estimate for each recommended alternative is provided. Costs of the recommended management options total to approximately $185,000 with local support (Groton) of about $60,000. I majority of the funds are being sought from the MA Clean-^Lakes I Program. I I I I TABLE OF CONTENTS
I PAGE I PART I. DIAGNOSTIC EVALUATION 1 Introduction 3 I Data Collection Methods 5 Lake and Watershed Description and History 9 Lake Description 9 I Watershed Description 13 Watershed Geology and Soils - -16 I Historical Lake and Land Use 20 Limnological Data Base 25 Flow and Water Chemistry 25 Supplemental Water Quality Sampling 45 I Tributary Sampling 45 Littoral Interstitial Porewater Sampling 50 Well Sampling 50 I Bacteria 53 Phytoplankton 56 Macrophytes 61 ZooplanKton 67 I Macroinvertebrates 67 Fish 71 Sediment Analysis 72 I Comparison with Other Studies 76 Questionnaire Survey 87 I Hydrologic Budget 93 Nutrient Budget 107 Phosphorus 107 I Nitrogen 117 I Diagnostic Summary 119 I PART II. FEASIBILITY ASSESSMENT 121 Evaluation of Management Options 123 Available Techniques 123 I Evaluation of Viable Techniques 128 I I
I iii I PAGE I Water Level Control 133 Elements of a Drawdown Program 133 • Installation of a Pond Drain 135 I Installation of a Permanent Siphon 138 Installation of a Temporary Siphon 145 Anticipated Impacts of a Drawdown 148 I Costs, Permits and Summary 152 • Macrophyte Bottom Barriers 153 • Elements of Program 153 | Anticipated Impact of Improvements on Lost Lake / Knopp's Pond 155 . Costs, Permits and Summary 155 I Watershed Management - Improving Surface Water Quality 159 Elements of Program 159 I Land Use Controls 159 I Adoption of Best Management Practices " 165 Residents' Environmental Practices 167 • Anticipated Impact of Program 171 • Costs, Permits and Summary 171 Watershed Management - Groundwater Protection and I Management 173 • Elements of Program 173 Land Use Controls 175 • On-site Wastewater Disposal Systems 177 | Alternative Technologies for Septic Systems 178 Mitigation of Impacts by Existing Septic Systems 180 H Anticipated Impact of the Groundwater Protection and I Management " 183 * Costs, Permits and Summary 183 Recommended Management Approach 185 I Discussion of Recommended Options . 186 Anticipated Impacts of Proposed Management Actions 187 • Monitoring Program 189 I Funding Alternatives 193 Contact Agencies 195 Environmental Evaluation 199 Environmental Notification Form 199 i Comments by Interested Parties 199 Relation to Existing Plans and Projects 199 • Feasibility Summary 201 References 205 i i i 1 1 PAGE APPENDICES : 1 Appendix A - Educational Information About Land and Wastewater Management for Minimization of Ground Water Pollution 1 and Best Management Practices Appendix B - Environmental Notification Form i Appendix C - Comments by Interested Parties and Sample Survey Questionnaire Appendix D - Data and Calculations i• - 1. Water Quality Data 2. Biological Data 3. Calculation Sheets and Useful i Conversions i Appendix E - General Aquatic Glossary i i i ~ i • i i i i i i i - -: 1 1 LIST OF TABLES 1 PAGE Table 1 Characteristics of Lost Lake / Knopp's Pond and Watershed 10 Table 2 Values of Monitored Parameters in the Lost Lake / Knopp's 1 Pond System 26 Table 3 Tributary Water Quality Data in the Lost Lake / Knopp's 1 Pond System 48 Table 4 Lost Lake / Knopp's Pond Porewater Quality Data 52
1M Table 5 Well Water Quality Data in the Lost Lake / Knopp's Pond Watershed 55 I Table 6 List of Aquatic Macrophytes in Lost Lake / Knopp's Pond 66 I Table 7 EEC Fishery Survey Results 74 Table 8 Lost Lake / Knopp's Pond Sediment Calculations 80 I Table 9 Chemical Characteristics of Lost Lake / Knopp's Pond Sediment 81 Table 10 Historic Water Quality Data from the Lost Lake / Knopp's I Pond System. 84 Table 11 Summary of Questionnaire Responses for the Lost Lake / Knopp's Pond Study Area 88 I Table 12 Precipitation Data for the Groton, Mass. Area 96 I Table 13 Hydrologic Budget for Lost Lake / Knopp's Pond 104 Table 14 Nutrient Export Coefficients 109 I Table 15 Nutrient Load Generation 110 Table 16 Equations and Variables for Load Derivation 111 I Table 17 Phosphorus Load to Lost Lake / Knopp's Pond Based on Models 112 Table 18 Phosphorus and Nitrogen Mass Flows in the Lost Lake / I Knopp's Pond System 114 Table 19 Nutrient Loads to Lost Lake / Knopp' s Pond Based on I Empirical Data 116 I Table 20 Lake Restoration and Management Options 124 I
I Vll I PAGE I Table 21 Sequence of Construction Activities Associated with the Installation of a Bottom Drain at Lost Lake / Knopp's Pond 139 I Table 22 Costs Associated with Installation of Pond Drain 141 Table 23 Sequence of Construction Activities Associated with the i Installation of a Permanent Siphon at Lost Lake / Knopp's Pond 144 I Table 24 Costs Associated with Installation of Permanent Siphon 146 Table 25 Zoning and Developmental Options 160 i Table 26 Best Management Practices Categories 166 Table 27 Typical Alternative Equipment and Technologies for On-site i Wastewater Management. 179 Table 28 Anticipated Impacts of Proposed Management Actions on the Phosphorus Budget for Lost Lake / Knopp's Pond 188 i Table 29 Costs of Three Year Monitoring Program Associated with Management Options 190 i Table 30 Local Costs of Recommended Management Options 194 i Table 31 Potential Funding Sources for the Proposed Restoration of Lost Lake / Knopp's Pond 196 Table 32 Permits and Approvals 202 i Table 33 Summary of Management Actions, Implementation Schedule and Associated Costs 203 i i i i i i i
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LIST OF FIGURES 1 PAGE Figure 1 Location of Sampling Stations at Lost Lake / Knopp's Pond, 1 Groton, Mass. 6 Figure 2 Bathymetric Map of Lost Lake / Knopp's Pond 11 1 Figure 3 Hypsographic Curve of Lost Lake / Knopp's Pond 12 Figure 4 Lost Lake / Knopp's Pond Watershed (with, sub-drainage 1 basins) 14 Figure 5 General Features of the Lost Lake / Knopp's Pond Watershed 15 1 Figure 6 Land Use Classification in the Lost Lake / Knopp's Pond Watershed 17 1 Figure 7 Soil Type Classifications in the Lost Lake / Knopp's Pond Watershed 18 1 Figure 8 Temperature and Dissolved Oxygen Depth Profiles; 1987-88. 31 Figure 9 Tributary Sampling Sites in the Lost Lake / Knopp's Pond 1 Watershed 46 1 Figure 10 Locations of LIP Sampling Sites in Lost Lake / Knopp's Pond 51 Figure 11 Well Sampling Sites in the Lost Lake / Knopp's Pond Watershed 54 1 Figure 12 Lost Lake / Knopp's Pond Phytoplankton - Cell Numbers and Cell Volumes 55 1 Figure 13 Typical Vegetative Transects in Lost Lake / Knopp' s Pond 62 Figure 14 Distribution of Aquatic Macrophytes in Lost Lake / 1 Knopp's Pond 63 Figure 15 Benthic Cover by Aquatic Macrophytes in Lost Lake / 1 Knopp's Pond 68 Figure 16 Zooplankton Size Distribution in Lost Lake / Knopp's Pond 69 1 Figure 17 Fishery Survey Nets in Lost Lake / Knopp's Pond 73 Figure 18 Soft Sediment Depth in Lost Lake / Knopp's Pond 77 1 19 1 Figure Location of Historical Sampling Sites 83 1 1 I PAGE I Figure 20 Schematic Lake Hydrologic Budget 94 Figure 21 Comparison of study year precipitation to 30 year average 97 I Figure 22 Location of Seepage Meters in Lost Lake / Knopp's Pond 99 Figure 23 Groundwater Table Topography in the Lost Lake / Knopp's I pond Watershed 101 Figure 24 Schematic Lake Phosphorus Budget 108 I Figure 25 Groton Center Sewer District 131 Figure 26 Lost Lake Dam Plan, Elevation Views and Sections 134 I Figure 27 Proposed Dam Underdrain - Top view 136 I Figure 28 Proposed Dam Underdrain - Profile 137 Figure 29 Proposed Permanent Siphon - Top View 142 i Figure 30 Proposed Permanent' Siphon - Profile 143 Figure 31 Proposed Temporary Siphon - Profile 147 i Figure 32 Application of Benthic Barrier 154 i Figure 33 Location of Proposed Benthic Barrier Application at Sargisson Beach 157 Figure 34 Town Zoning in the Lost Lake / Knopp's Pond Watershed 163 i Figure 35 Open Space and Conservation Lands in the Lost Lake / Knopp's Pond Watershed. 164 i Figure 36 Site Constraints for Selecting Best Management Practices 169 Figure 37 potential Well Sites and Recharge Zones in the Lost i Lake / Knopp's Pond Watershed. 174 Figure 38 Water Resources Protection Overlay Districts, Groton MA. 176 i i i i i i PART I. DIAGNOSTIC STUDY I I INTRODUCTION
The establishment of the Massachusetts Clean Lakes Program I under Chapter 628 of the Acts of 1981 enabled many municipalities to acquire funding for study and restoration of their lakes. As an environmentally aware and concerned community, the Town of I Groton applied for a grant for a Phase I Diagnostic/Feasibility study of Lost Lake / Knopp's Pond. After being awarded the grant, the Town contracted Baystate Environmental Consultants, I Inc. to conduct the study. Concern over the present and future status of Lost Lake / Knopp's Pond has prompted the request for a study. The water I quality impacts of development activities in the Lost Lake / Knopp's Pond watershed were not quantified. The recreational status of Lost Lake / Knopp's Pond has been perceived to have I deteriorated over the past years. Mitigation of present negative influences on the lake and planning to preserve recreational I value to this heavily used water resource were desired. I I I I I I I I I I I I 4 I I I DATA COLLECTION METHODS i Previous studies of Lost Lake / Knopp's Pond and water bodies in the watershed were reviewed, as were historical records of lake water quality. Maps prepared by the United States Geological Survey (USGS) and the Soil Conservation Service (SCS) were used to initially assess watershed characteristics and I establish hydrologic connections. Of particular use were the USGS (1979) Ayer Quadrangle Sheets from the 7.5 minute series, the Public Works Bedrock Geologic Map (Zen, 1983), and the soil survey reports prepared by SCS. Land use and vegetation cover I maps were obtained from the (University of Massachusetts, 1975) Massachusetts Map Down program. Contemporary land use information was provided by infrared (1985 survey) aerial I photography obtained from the National Cartographic Information Center (NCIC) . Additional information came from maps provided by the Groton Conservation Commission. Areal measurements were made I with a Planix Electronic Planimeter. Determinations made from maps were verified by field inspection by staff engineers and biologists. I Historical lake and land use were investigated through conversations with watershed residents, newspaper and technical and field inspection. Conversations with members of the Groton I Clean Lakes Committee and Knopp' s Pond and Lost Lake Watershed Association were especially useful. Ms. Majorie Eger provided excellent liaison with the latter and the Town of Groton. I Coordination with the Groton Conservation Commission and Planning Board was through Ms. Michele Collette. Mr. Kenn Thompson was very helpful in providing access for BEC boats at Knopp's Pond. I The Lost Lake / Knopp's Pond bathymetric map was prepared with an Uniden fathometer and compared to that made by the Massachusetts Division of Water Pollution Control (MDWPC) 1984). I Soft sediment depth was assessed visually by teams using SCUBA and snorkeling gear and by driving a probe to first refusal. Notes were made about the underlayment and other characteristics. These measurements were performed by divers in conjunction with I the macrophyte check. A comprehensive monitoring and investigative research program I was instituted to assess the physical, chemical, and biological • characteristics of Lost Lake / Knopp's Pond. Regular sampling stations were selected from field inspection. These stations are I described and shown in Figure 1. The in-lake stations were regularly sampled at surface and bottom stations and at the metalimnion when stratification was in evidence. All stations were sampled monthly during October 1987 to March 1988 and I approximately biweekly between April and September 1988. I I I Figure 1. Location of Sampling Stations in Lost Lake / Knopp's Pond.
KP-2
KP-7
6 I Fifteen parameters were routinely assessed at all sampling I locations. Details of sample collection and processing methodology are given in the Appendix. Temperature and dissolved oxygen levels were measured with Yellow Springs Instrument (YSI) model 57 meter, with vertical profiles obtained at the in-lake I stations (0.5m intervals). The pH was measured with an Orion model SA250 pH meter. Conductivity was assessed with a YSI model 33 meter. A four liter water sample was taken at each sampling I location and transported to Arnold Greene Testing Laboratories in Natick, MA for analysis of suspended solids, turbidity, total alkalinity, chlorides, total Kjeldahl nitrogen, nitrate nitrogen, ammonia nitrogen, total phosphorus, and orthophosphorus by I accepted standard methods (e.g., Kopp and McKee, 1979; APHA et al., 1985). Separate bacterial samples collected for fecal coliform and fecal streptococci analyses were performed by Arnold I Greene Testing Laboratories by standard methods (membrane filter technique). I Flow was assessed at all stream stations, using either the float method or Gurley Standard flow meter where appropriate. A 20 cm Secchi disk was lowered on the shady side of the boat to evaluate water transparency at the in-lake stations. Analyses of I chlorophyll concentration and features of the phytoplankton and zooplankton communities were made for those locations as well. Phytoplankton samples were obtained from a depth integrated I epilimnetic composite sample, while zooplankton samples were collected by oblique tow on an 80 micron mesh net. Phytoplankton samples were preserved with Lugol's solution and zooplankton I samples were preserved with a formalin solution. Plankton samples were analyzed microscopically for species composition, relative abundance and biomass. The size distribution of the zooplankton was also assessed, and all data were recorded and I tallied using a microcomputer routine developed by EEC and Cornell University personnel. I Sediment samples were obtained from the in-lake stations with an Ekman benthic dredge. Samples were analyzed by Arnold Greene Testing Laboratories for total Kjeldahl and nitrate nitrogen, total phosphorus, organic/inorganic fraction, heavy metals (Cd, I Cr, Cu, Fe, Mn, Pb, Zn), and oil and grease. Macrophyte species composition and areal extent of cover were I assessed by visual inspection during bottom transects by SCUBA divers. The distribution of summer bottom cover was mapped, noting dominant species in each area. . Qualitative notes were made on the subsurface density, composition, and -distribution of I macrophyte stands by the diver. Determination and mapping of macrophyte characteristics were made in August, 1987 and I rechecked in August 1988. I I
I 7 I Ground water seepage measurements were made with seepage meters, according to the method outlined in Mitchell et al. • (I988a). These seepage meters are essentially portions of | standard 55-gallon drums which are fitted with a spout and bags to measure the incoming or exiting water in the bounded benthic _ area. The seepage meters were placed in transects at regular • intervals (75-123 m) around the lake to determine the actual ™ amount of inflow or outflow. By fitting transect flow values to a linear equation and integrating, the inflow or outflow per unit • of shoreline length can be computed for each segment of I shoreline. Alternatively, an average flow value per transect was sometimes employed. Total inflow and outflow were calculated as • the sum of appropriate shoreline segments (see Appendix for I calculation sheet). Seepage at Lost Lake / Knopp's Pond was sampled during two periods : August-September 1987 and June 1988.
Pore water for chemical analysis was obtained by inserting a P littoral interstitial porewater (LIP) sampler into a substrate and:gently suction pumping the pore water out of the sediment . • with flexible tubing, an intermediate trap and a hand pump. The | apparatus is a modified pointed stainless steel tube mini-well with sampling ports and protective brass screens. Details of the _ LIP sampling device and methods are available in Winter et al., I 1988; Mitchell et al, 1988b). Water was extracted from twenty m sites at regular intervals around the periphery of Lost Lake / Knopp's Pond. At each location, 3-5 sub-samples were taken and I composited. Sampling of the porewater was done in June 1988. I The porewater was analyzed for the nutrient and general parameters outlined above. m A questionnaire survey was performed to assess the preferences and practices of watershed residents. Questionnaires were prepared and distributed by -Qroton Lakes Committee and BEG • personnel. Although emphasis was placed on properties near the • lake, Groton residences up to 1000 m from Lost Lake / Knopp's Pond and additional households in the watershed were surveyed. Responses were tallied and interpreted by BEC personnel. i i i i i i i 8 I I LAKE AND WATERSHED DESCRIPTION AND HISTORY I Lake Description Lost Lake / Knopp's Pond is located in the Town of Groton, I Middlesex County, Massachusetts. It lies in the Merrimack River Basin at latitude 42 degrees and 36 minutes and longitude 71 Degrees and 32 minutes (MDWPC, 1986) . The shape of Lost Lake / I Knopp's Pond is very irregular and contains several small islands (Figure 1). The lake has an area of approximately 83 hectares (205 acres). The shoreline length is approximately 10.85 km (6.74 mi) . The sinuous nature of the shoreline and embayments is I reflected by the high value for shoreline development of 3.36 (Table 1) . [Note that a perfect circle would have a value of 1.0]. The maximum distance in any one direction (or longest I fetch) is 1.55 km (0.96 mi). Lost Lake / Knopp's Pond consists of two very different lake I basins. Knopp's Pond has a roughly rhomboid configuration, consisting of three separate basins connected by shallower areas (Figure 2) . These basins represent the original natural ponds, before enhancement of the flowage through impoundment. The I deepest point in Knopp's Pond was determined to be 9.0 m (29.5 ft) at normal pool elevation (214 ft above sea level), located within the northeastern deep basin. The shape of Lost Lake is I much more linear. There is a small basin at the northern end just upstream of the outlet structure. Depths approaching 5 m (15 ft) have been measured here. Otherwise, the depth of the I bottom of Lost Lake is generally about 2 m (6-7 ft) . The depth-areal relationship shown by the hypsographic curve projects a rather uniform decrease in area to 3 m (10 ft) , and a I rapid decrease at greater depths (Figure 3) . The full volume of the lake was calculated to be 1,843,000 cu. m (or 1,495 acre- feet) . The lake level drops 0.6m (2 ft) over the course of a I season, based on the presence/absence of two stop-logs placed in the outlet structure. These stop-logs are placed in late April and removed in October. There was no appreciable outlet flow during periods when the lake was filling to the summertime level I (late April - early May). The major tributary is Martin's Pond Brook (designated KP-2) which flows throughout the year. The lesser tributary (KP-1) was observed flowing from winter to early I summer (December through June). Movement of a permanent groundwater seepage flow to Knopp's Pond (KP-7) was sampled from March.1988 to the end of the sampling year. It apparently flows throughout the year, according to several abutters. Based on I available data about surface water and ground water flows, an annual average input of 8.8 cu.m/min (5.2 cubic feet per second) is expected (for details consult Hydrologic Budget section). I Thus, the average detention time for water in Lost Lake / Knopp's I Pond is 0.40 yr or 146 days. I I I
TABLE 1 I CHARACTERISTICS OF LOST LAKE / KNOPF'S POND AND ITS WATERSHED I Lake Measures Location: Town of Groton, Middlesex Cty, 42°35'40" lat. 71°31'45"long I Area: 83.0 ha (205 acres) Depth: Mean 1.8 m (5.9 ft.) I Maximum 9.0 m (30 ft)
Volume: 1,843,000 m3 (1,495 acre-ft.) Detention Time Mean 0.405 yr (148 days) I Range 0.155 - 2.92 yr ~(57"-L-f067 day's)" Maximum Length 1.55 km (0.96 mi) I Maximum Width 0.73 km (0.46 mi) Shoreline Length 10.85 km (6.74 mi) Shoreline Development 3.36 I Watershed Measures Area (Excluding LL/KP) 1158 ha (4.46 sq. mi I Watershed Area/Lake Area 14:1 Land Use: I % Forest 49.3 % Residential 24.8 % Agricultural 10.5 6.6 I % Open % Marsh /Wetland 5.7 % Water (w/o LL/KP) 1.5 % Recreational 1.4 I % Commercial 0.3 I I I I I I 10 I LOST LAKE / KNOP'S POND Bathymetric Map ( contours in 1 meter intervals )
I I I I I 100 m I I Figure 2. Bathymetric Map of Lost Lake / Knopp's Pond. 1 Lo5j Figure 3i Hypsographic Curve of Lost Lake / Knopp's Pond. l l l l - • .-...--_-.-.-. - ! l Hypsographic Curve of Lost Lafce/Knopp's Pond - l 0 ; l -2- l 1 -4- w "& / i •*o -6- i -8- i( -10 i l 0 20 40 60 80 100 % area deeper than given deptb l
- ' l * i i i i 12 i I Lost Lake / Knopp's Pond is accessible to the public through I a town-owned boat launch off Whiley Road. There are several public and private swimming beaches for residents and non- residents. The larger of these two is located at the southeast side of Knopp's Pond and is called Sargisson Beach. There is I considerable land owned by the Groton Conservation Trust around I the lakes. Watershed Description I The watershed of Lost Lake / Knopp's Pond covers an area of 1158 ha (4.46 sq. mi), which is located entirely in the town of Groton (Figure 4) . Measurements were based on information from the United States Geological Survey topographic map (7.5 minute I series) of Ayer {USGS, 1977) . The surface watershed area to lake- area ratio is approximately 14:1. The large watershed area—means that much of the nutrient load is derived from the watershed. The I functional watershed boundaries are roughly Whiley Road, Lost Lake Drive, Schoolhouse Road, the road north of Martin's Pond, west of Shattuck Street, Route 40, Lover's Lane, Whitman Road, south to Boston Road, the eastern end of Indian Hills Road, I southeast to Sandy Pond Road and encompassing the Four Corners area (Figure 5). I While information from the topographic map can delineate the surface drainage area, the area of ground water influence is not so easily traced. The general topography of the surface I watershed is very variable with flat (0-3%) and steep slopes in the watershed. The soils surrounding Lost Lake and Knopp's Pond are mostly loamy sands (primarily Quonset) . Infiltration of surface precipitation into the ground water is likely to be I appreciable. The ground water watershed of Lost Lake / Knopp's Pond may I differ substantially from the surface watershed. The major portion of the watershed to the northwest consists of prominent geographic features (drumlins) surrounded by extensive wetland areas. These till drumlins are akin to islands floating in a I swampy sea. To the south of Knopp's Pond, the surface is pockmarked by numerous depressions or kettleholes. Ground water flow in shallow strata moving toward Lost Lake / Knopp's I Pond would be intercepted by these hydrological features and temporarily detained. It is quite possible that the movement of the ground water in the deeper strata is different (overall I regional drainage moves in a northeasterly direction). However, influence of this deep ground water on Lost Lake / Knopp's Pond is apt to be slight, as the region of contribution to a lake is I usually located in the 0 to 2 m water depth. I I I Figure 4. Lost Lake / Knopp's Pond Watershed.
Sub-Drainage Basins.
A = Martin's Pond Brook.
B = Unnamed tributary.
C = Direct drainage.
Scale = 1 : 25,000 I I Figure 5. General Features of the Lost Lake / Knopp's Pond Watershed. I I I I I I I I I I I I I I I I I I The composition of most of Lost Lake / Knopp's Pond watershed is a mixture of land uses (Figure 6). The major land uses are M forested (49.3%), residential (24.8%), and agriculture (10.5). • This constitutes 84.6% of the watershed (Figure 5). Other important land uses and their respective percent of the watershed • are: open area, 6.6%; wetland areas, 5.7%; open water (other than | Lost Lake / Knopp's Pond), 1.5%; recreational, 1.4%; and commercial, 0.3%. _
Watershed Geology and Soils ' The Lost Lake / Knopp's Pond watershed is largely the result •I of late Pleistocene (i.e., Wisconsin) glaciation. The local bedrock tend toward high-grade migmatitic schists and gneisses of • the "Nashoba" group (Stone and Peper, 1983). For example, there I are local granite quarries just to the west of the ancient Clinton-Newberry fault line (Caldwell and Cook, 1981). However the .effect on these bedrock materials on water quality is largely I reduced by their depth and the influence of the Quartenary • geology of the area. The features of the Lost Lake / Knopp's Pond morphosequence are dictated by the extent and location of • events in the late Wisconsin glaciation about 13,000 years ago. | These major glacial features include: sinuous meltwater deposits (eskers), rounded till deposits (drumlins), and depressions • (kettles) in pitted, outwash plain. All three are found in I abundance within the Lost Lake / Knopp's Pond watershed. The — high ridges near the lakes are good examples of eskers. A concentration of drumlins is- found on the western margin of the I watershed, stretching in a line from the Indian Hills to Gibbet I Hill. The area to the south and southwest of Knopp's Pond contains numerous small depressions or kettles. • The meltwater deposits in question are primarily glaciolacustrine (lake-derived) in origin. In the Groton area, glacial Lake Nashua and the Shawsheen-Merrimack Basin lakes were • the two predominant influences. These were lowland glacial lakes • impounded by the north-sloping valleys along the margin of the retreating ice sheet. Typical deposits resulting from these • features consist of 1 to 4 m of fluvial topset gravel and sand, | which overlie 5-12 m thick layers of sand, pebbly sand and silt (Stone and Peper, 1983). These deposits are responsible for the _ largely sandy composition of the watershed soils. I The soil classifications for this portion of Middlesex County are still unpublished. However, the major soil groups in the I Lost Lake / Knopp's Pond watershed were identified by personnel I of the Soil Conservation Service. The soil types and their locations are shown in Figure 7. The major soils in the • watershed are: Quonset loamy sand, Bernardston silt loam, Whitman I and Woodbridge fine sandy loams, and Swansea and Freetown mucks. i i 6 LOST LAKE / KNOPF'S POND WATERSHED I (approximate scale = 1 : 23,000) I Key to Land Uses = Orchard I = Pasture = Row crops = Commercial I H = Forest = Goir course I = Residential (low) = Residential (med.) 3 = open I = Recreational = Wetland I = Open water I I I I I I I I I I I Figure 6. Land Use Classification of the Lost Lake / Knopp's Pond Watershed.
I 17 Figure 7. Soil Type Classifications in the Lost Lake / Knopp's Pond Watershed.
Approximate Scale 1 : 28,000.
I 8 I I FIGURE 7 (CONT.) I SOIL CLASSIFICATION IN THE LOST LAKE / KNOPF'S POND WATERSHED I Designation Description Bb Bearnardston silt loam Be Bearnardston silt loam, very stony I Bd Birdsail silt loam Ca Canton fine sandy loam Cb Canton very stony fine sandy loam I Cc Canton extremely stony fine sandy loam Ch Chatfield-Hollis rock outcrop complex Fm Freetown muck Fp Freetown muck ponded I MX Montauk very stony fine sandy loam Pd Paxton-urban land complex Qn Quonset loamy sand I Ra Raynham very fine sandy loam Rd Ridgebury fine sandy loam Re Ridgebury very stony fine sandy loam Sc Scitico silt loam I Sd Sudbury fine sandy loam Sg Scituate fine sandy loam Sh Scituate extremely stony fine sandy loam I Sw Swansea muck Ud Udorthents, stony Wb Warwick finds sandy loam I Wh Whitman fine sandy loam Wn Windsor loamy sandy Wt Woodbridge fine sandy loam I Wx Woodbridge very stony fine sandy loam I I I I I I I
I 19 I Many of these soils are characterized by their extreme permeability, which can be 50 cm/hr or more (SCS, 1986). This • has two important implications for the Lost Lake / Knopp's Pond | system. There is considerable percolation of precipitation into th§ ground water and nutrients can move rapidly within the ground « water zone. I Historical Lake and Land Use i The records of Lost Lake / Knopp's Pond are tied to the history of Groton. There is historical mention of hydrological • features in deeds recorded soon after the first grant of the | Groton Plantation (also called Petapawag) in 1655. Among these eatly settlers was one James Knap (or Knop), whose lands were — demarcated in the 1660's (Green, 1885). The small pond located I on these lands came to be known as Knap's or Knop's or Knopp's ™ Pond. Knopp's Pond originally occupied only the deepest northeastern basin. There was inlet from an adjacent pond to the • south, Springy Pond. The outlet stream of Knopp's Pond flowed I northerly through Cow Pond Meadows to Cow Pond (a.k.a. Whitney's Pond). These meadows are mentioned in town records dating from • 16$4. The outlet of Cow Pond was Cow Pond Brook which flows into I Massapoag Pond and, eventually, the Merrimack River.
In Cow Pond Meadows the stream arising out of Knopp's Pond I joined by a small tributary arising from the west. This ™ tributary passed through a hydrologic feature known as Way Pond in colonial times, and drained the area known as Indian Meadows • (south of Indian Hills ?) by Butler (1848) . While it may have at | on§ time been referred to as Way Pond Brook (Green, 1912), the current topographic map does not show a name for this tributary. _ The other major stream draining to Cow Pond Meadows was the * outlet of Martin's Pond (another pond named after an early Groton settler). Martin's Pond Brook presently drains this pond to the • southeast. It joins another stream, formerly known as Brown • Loaf Brook (May, 1976), near the old site of school-house #9 (Butler, 1848). Records indicate that the drainage from Martin's • Pond Brook originally passed to the west into James Brook via I Half Moon Meadows, north of Gibbet Hill. Thus, drainage from this pond was diverted from the Nashua to the Merrimack River watershed. This stream has had its present course since the late I 1700's (Butler, 1948; Green, 1912; May, 1976). • The hydropower potential of these streams was soon tapped by • local inhabitants in several enterprises. The stretch of land | between Cow Pond Meadows and Cow Pond was the site of a dam and associated saw-mill, which was succeeded by a paper-mill. This _ paper-mill was taken down about the end of the Civil War (Green, I 1912). •i i 20 I At some point in the nineteenth century, possibly around the late 1860's, the water rights to Knopp's Pond were apparently I secured by the Harbor Manufacturing Company, a mill concern based in Nashua, New Hampshire. This company used the waters of the Merrimack and wanted to insure a more seasonally constant water I supply for its mills. A wooden dam was constructed at the narrowest constriction between Knopp's Pond and Cow Pond Meadows to impound the waters of Knopp's Pond. It remains are still I clearly visible beneath the water surface of the water at this location. This impoundment enlarged the size of Knopp's Pond, backflooding Springy Pond and making a direct surface connection between the two. Reports of abundant stumps on the shores of I Knopp's Pond indicate that forested areas were impacted (MA DFW, 1911). "A map of the area from the 1880's indicates the increased size of Knopp's Pond relative to Duck Pond (Green, 1885). The I enlarged pond occupied about 55 acres (MA DFW, 1911; Green, 1912) Near the end of the nineteenth century (1896-1897), I additional water rights were secured by Vale Mills of Nashua, New Hampshire. A second dam was constructed at the highlands between the outlet at the northern end of Cow Pond Meadows. This created a large body of water in Cow Pond Meadows, latter referred to as I Lost Lake or Mountain Lakes. The owners and controllers of the water rights were mentioned in MA DFW notes (1928) to be Gardner- Beardsall Corporation. Some later mention is made of water I rights owned by International Paper Box Machine Co, but the date of this correspondence was not available (MA, I960). It was before World War I that the building of cottages on I both Lost Lake and Knopp's Pond commenced. By 1911, there were sufficient cottage owners to complain about the occasional draining of Lost Lake (presumably for downstream water power) . I Foul odors and poor appearance were the chief complaint. These may have been produced by the decomposition of. organic material left in the meadows at the time of flooding. Another complaint was the worry that the drained areas were breeding places for I 1 mosquitos and "much malaria is caused" (MA DFW, 1911). Needless to say malaria is not a common problem in New England, and this concern was more likely linked to the American public's awareness I of "yellow fever" at the on-going Panama Canal construction, then to any local occurence of this disease. I The expansion of the railroads had an influence on Lost Lake / Knopp's Pond and its development as a summer resort. The Ayer - Lowell Street Railway or trolley car followed the present Route I 2 and passed about a mile to the south (MA DFW, 1-911) . Alternatively, there was the Stony Brook Railroad stopping at North Littleton Station, just 2 miles to the south. With this increased ease of access, holiday and summer excursions from I Boston and the suburbs became more frequent. I I
I 21 I The popularity of Lost Lake / Knopp's Pond as a vacation spot led to rapid development of the area, particularly the northern • end. Real estate developers sub-divided larger tracts into small | lots which they sold for summer homes. The major sub-division was owned by the Lost Lake Development Co. (Collins, 1985). — These undeveloped lots were widely advertised and could often be I purchased relatively cheaply. The name Mountain Lakes or Lost * Lake was coined by these developers, undoubtedly to provide more distinction to the waterbody than Cow Pond Meadows could provide. •
It was during these period (1900's to the 1920's) that many of the buildings in the watershed were built. Primitive "camps" • were improved by their owners into summer cottages. However, as I there were few building codes or standards for sanitary facilities during those days, these cottages were built with insufficient concern or acreage for protection of the ground I water. In this somewhat haphazard fashion, Lost Lake / Knopp's • Pond developed as a popular summer resort. Much of the lands surrounding the lake were converted from forested to part-time • residential. | The Great Depression led to a reshuffling of property rights _ in the Lost Lake / Knopp's Pond watershed. One critical event I was the bankruptcy of the Lost Lake Development and the ™ foreclosure of the property by the Highland Trust Company in 1932 (Collins, 1985). This bank subsequently failed and the property • assets were distributed by the Commissioner of Banks. ' I Acquisition of the water and flooding rights to Lost Lake was obtained by Groton Ridges Lakes, Inc. in 1934, This corporation • owns the dam and right to maintain it (Collins, 1985). Other I properties were later conveyed to the Groton Conservation Trust, including roads and common areas. The dam is now reportedly owned by the Lost Lake Water Committee, of which the Groton Woods I Baptist Camp owns about 80% of the shares (National Dam • Inspection Program, 1980). This group is provides the designated caretaker for its maintenance, •
The Depression also caused a fundamental demographic change to the Lost Lake / Knopp's Pond area. Economic circumstances « forced the conversion of many of the summer cottage to full time I homes (a trend which continues to this day) . These conversions • only proved how woefully inadequate the existing sanitary systems were to year-round usage, particularly in the steep, excessively- • drained soils characteristic of the watershed. In other cases, I the cabins were virtually abandoned, and left to decay. The present condition of this area still reflects this mosaic of • improved cottages co-existing with poorly-maintained or failing • structures. The present uses of Lost Lake / Knopp's Pond are mainly I swimming, boating, fishing and skating. Swimming is a very iB i 22 I popular activity is swimming due to the usually clear water conditions. There is a public beach maintained on the lake, a I large institutional beach (Grotonwood), a "locals"'beach, and numerous small private beaches. The public beach is Sargisson Beach, located on the southeast shore of Knopp's Pond. This I beach is opened for use during the summer months, and swimming lessons are conducted there. The Grotonwood beach is located on the western shore of Lost Lake, and is used by the guests of the I camp. Another small beach is located at the northern end of Lost Lake near the outlet structure. This beach, locally nicknamed "Baby Beach", has limited access and is used only for local resident bathing. A floating dock usually is placed just I offshore during the summer. Fishing is a very popular spring and summer activity, due to I state stocking and the easy access to the lake off Route 119. A developed boat launch, originally created by the Squannacook Rod and Gun Club (MA DFW, 1960) is located on the northeast side of I Lost Lake, in a secluded cove. Trout are stocked in the spring, and this is the period of greatest fishing activity. An aerial Creel survey (4/22/77 through 6/25/77) indicated about 11,500 hours of angling activity (MDFW, 1978). Declining trout catches I and increased competition for the water surface reduces the popularity of boat fishing in the summer. However, shoreline fishing for panfish is popular throughout the summer. Recent I recommendations for improvement of the fishery included increased Signage and acquisition of an additional boat ramp at the Southern end (MDFW, 1978). [Note: More historical and technical I details about the fishery are given in the Fish section]. Boating is a preferred activity and ranges from powered boats to rowboats or canoes to sailboats. Water skiing down the I length of Lost Lake is a popular activity. Restriction of this activity in Knopp's Pond is mandated by the placement of two low speed (6 mph) checkpoints, marked by warning buoys. Despite this I precaution there have been boating accidents (eg. September 1987) on the lake, mostly due to high operating speeds and the restricted line-of-sight causes by the many small coves. Activity tends to be concentrated in the late afternoon and I evening hours, as well as the weekend.Small sailboats are occasionally seen on the lake, and jetskis are in evidence. There is a rental boat livery on the southern end of Knopp's Pond I which provides rowboats. Activities during the winter months center generally upon ice-fishing and skating. The good access to the-lake and large I fish population makes this a popular and "substantial" ice fishery (MDFW, 1978) . Skating areas are established on the ice I during the winter months. I I I I While the lake was and continues to be the center of many recreational activities, concerted efforts to manage the lakes • have only recently emerged. An attempt to reduce the weed growth | was made in summer 1987, when the Massachusetts Clean Lakes Program funded a plant harvesting via hydroraking. This was done _ in public areas and was available informally for private areas. I In the past/ individual abutters may have practiced some • management of their shorelines. With regard to chemical control, fisheries records indicate that rotenone was sprayed in 1960 to • assess and control the fish population as part of a reclamation I effort (MDFW, 1960). No other chemicals were knowingly introduced into the lake as part of any subsequent program. m i i i i i i i i i i i i i 24 I I
I LIMNOLOGICAL DATA BASE Limnological data were collected for one year in an effort I to assess pond conditions and evaluate temporal and spatial variability in physical, chemical and biological parameters. Through this data collection, Baystate Environmental Consultants, I Inc. (BEC) seeks to understand the Lost Lake / Knopp's Pond ecosystem and to identify those factors which are critical to its maintenance. A considerable data base is generated through the course of this yearlong monitoring, not all of which is of equal I importance. It is necessary to distinguish between the critical items and those of more general interest or minimal utility in the management of the system. Therefore, in the interest of I brevity, most raw data has been incorporated into the appendices of this report. Included in these appendices are calculation sheets which detail the derivation of useful values and other I information of secondary importance. I Flow and Water Chemistry The waters of Lost Lake / Knopp's Pond are a composite of the dilute mixture of chemical substances introduced by the I weathering of rock in the watershed, from seasonal precipitation, and from cultural use of the landscape (e.g., housing) including the infrastructure (e.g., roads) which supports this culture. The importance of these various source to Lost Lake / Knopp' s I Pond is dependent on both their concentration and the measured volume of water containing these substances which flows into the pond. Flow characteristics are thus of major potential I importance in any system. Lost Lake / Knopp's Pond is a combination of three natural ponds enhanced by flowage created by the impoundment of the I waters of three surfaces-tributaries : Martin's Pond Brook, an unnamed tributary andfajjjemergent seepage flow locally referred to as "Redwater". The flow of these—tributaries during the study I year was determined by (£iine-weightiji,g-^bo compensate for the different amounts of days -betwe'en sampling dates (Table 2) . The most important of these, Martin's Pond Brook (KP-2) had a mean I flow of 3.8 cu. m/min. (2.2 cfs) . The unnamed tributary (KP-1) had a mean flow of 1.6 cu. m/min. (0.94 cfs), while Redwater (KP- 7) added 0.3 cu. m/min. (0.18 cfs). The summed total of these tributaries was 5.7 cu. m/min. The measured mean outflow (KP-6) I was 5.2 cu m/min. t There are additional water inputs from other sources I including direct precipitation, stormwater drain flows, overland flows, and groundwater seepage. Losses from the pond include evaporation and outseepage. Derivation of groundwater, I precipitation and stormwater inputs, as well as evaporative I losses, are detailed in the Hydrologic Budget of this report. 25 TABLE 2. WILUES OF MONITORED PARAHETERS IH THE LOST LfiKE / KNOWS POHD SVSTEH O987-1988>.
PARAHETER UHirS VALUE TVPC KP-1 KP-2 KP-3s KP-3n KP-3b KP-1s KP-1b KP-Ss KP-5b KP-fc Kf-7
FLOH CU.H/HIH HEAH O> 1.6 3,8 5.2 .3 HAXIHUH 1.9 11.6 11.6 1.1 HI HI HUH 0.0 .3 .3 .1
TOTftL PHOSPHORUS Ufi/L HEAH C2> 61 88 39 17 10 36 11 11 12 ("•171 • 5? HAKIHUH 260 190 70 70 80 80 90 81 90 110" 111 HI HI HUH 15 10 10 10 10 10 10 10 10 10 HI
ORTHOPIIOSPHORUS UG/L HERN C2> 13 31 12 18 13 13 11 11 11 12 27 HAXIHUH 22 11O 30 30 26 30 33 19 10 29 80 HI HI HUH 10 10 10 10 10 10 10 10 io 10 10
AHHONiR NITROGEN HG/L HERN C2> .02 .09 .02 .01 .02 .02 .02 .01 .02 (ToT) .03 HAXI HUH .05 .78 .06 .01 .06 .06 .01 .21 .01 las -11 HI HI HUH .01 -01 .01 .01 .01 .01 .01 .01 -01 .01 -Ol
HITRRTE HITROGEN HG/L HEAH C2) .05 .23 .05 .02 .05 .01 .03 .05 .05 &} .02 HRXIHUH .08 .17 .13 .02 .12 .11 .10 .28 .22 ^33 -OS HI HI HUH .02 .02 .01 .02 .01 .01 .01 .01 .01 -Ol -O2
TOTRL KJElDflllL N1TROGEH HG/L HEAH C2> .13 .52 .27 .30 .37 .31 .13 .36 .16 .35 .21 HAKIHUH .61 1.30 .37 .35 1.10 .16 .98 .55 l.l .60 .11 HO HI HI HUH .32 .32 .10 .23 .18 .22 .26 .25 .32 .21 ,0/ CT» N1TROGEN:PHOSPHORUS RATIO HONE HEAH 35 25 23 16 31 28 36 31 21 31 18 HflXIHUn 85 130 57 20 111 61 106 121 121 152 83 HI HI HUH 3 8 7 11 9 12 11 11 11 8 5
TEHPERATURE CELSIUS HAKIHUH 19.0 26.5 29.1 26.3 19.0 29.9 29.2 29.6 23.1 29.9 19.2 MI HI HUH -1.1 -3.5 0.0 11.3 2.0 -.5 2.9 0.0 2.5 -1 7.9
DISSOLVED OXVGEN HG/L HEAN 11-1 9.0 9.5 9.9 2.1 9.5 6.5 9.7 5.1 9.1 7.1 HAXI HUH 15.7 13.3 12.7 12.8 7.1 13.1 9.6 11.7 13.8 15.2 9.2 HI HI HUH 8.8 5.9 7.1 7.3 .1 7.2 .6 7.1 .2 6.5 S.I
D.O. SATURATION Z HEAH 95 82 91 115 20 91 61 91 12 41 7O HAKIHUH 108 102 1 12 129 52 116 101 119 106 120 81 • HI HI HUH 80 57 62 101 1 70 3 76 2 55 1.'
HG/L HEAN C2> 1.6 2.2 2.7 Gl-Fl G.-il .9 6.5 TOTRL SUSPENDED SOLIDS (JTv (5.1}
TURBIDITV N.T.U. HEAN 1.7 2.0 1.2 1.7 2.5 1.3 1.6 1.2 1.5 1.1 11.7 HAXIHUH 1.2 9.0 3.1 3.1 11.0 3.0 5.0 2-0 3.1 1-3 S3.Q HIHIHtlH .6 .5 .1 .6 .5 .3 .1 .1 .3 .5 1.7
CONDUCTIVITY UHHOS/CH HERH C2> 18 172 153 152 151 111 119 112 138 137 110 HAXIHUH 89 265 188 182 190 183 188 102 183 101 139 HI HI HUH 39 132 SO 87 92 59 101 68 SO 1OS 81 TABLE 2 CCO(ITINUED)
PflRHHETER UNITS VflLUE TVPE KP-1 KP-3s KP-3* Kp-3b KP-13 KP-1b KP-5s KP-6 KP-?
pit MEAN <3> 6.2 6.1 6.2 6.5 6.2 6.3 6.3 6.1 6.1 6.1 6. "5 S.U. HflKIHUH 7.0 7.2 7.1 7.0 7.2 7.3 7.2 7.5 7.1 7. '5 HI HI HUH 5.7 6.-| 5.7 6.2 5.5 5.6 5.6 5.6 5.6 5.6 5..;
TOTAL ALKALI HI TV HG/L HEM C2> 8.0 27.1 26.8 28.1 28.1 21.S 21.9 21.1 25.7 25.2 11 5 itnxinun 11.0 52.0 32.0 30.0 31.0 33.0 29.0 30.0 32.0 31.0 23. O HI HI HUH 5.2 23.0 21.0 25.0 22.0 11.0 19.0 11.0 IB. 5 17.0 1 1 -ID
CHLORIDE HG/L. HEfW C2> 5.8 29.9 27 .8 26.6 27.6 25.3 25.1 21.1 25.6 25.7 21. ;2 HflKIHUH 11 36 31 30 32 32 31 30 30 30 3.2 HI HI HUH 3 22 21 23 22 11 21 17 18 17 11 -~- — -~^ TOTAL IRON HG/L HEAN C2> .30 -20 £Tf) .11 -«\ /Cio) .15\ (To?) TTifi .09 HAKIHUH .68 -75 ( Ttw .19 t rr? .11 \ Iris .21\ .28 \4P-1O, HI HI HUH .21 -11 \02 .09 __Ifl2>* V.,02 .03 ) [.02 -Q?J .02 .3:3
FECAL COLIFORH H/100HL HEAN <1> 13 .^__ . — —9 — 9 , 9 _U5 HfWIHUH 210~ IQCIO 10 10 10 20 35O HI HI HUH 10 1 0 o 0 0 10
FECAL STREPTOCOCCI H/100HL MEAN <1> 153 1Q75 30 38 63 96 81 nnxiniiH BOOOO 75000 1000 rooo 150OO 27000 3500U no HI HI HUH 10 10 10 0 0 10 H3 CIILOROrilfLL fl UG/L HEAN 1-9 1.6 2.1 HflXJHUH 1.1 3.6 1.1 HI HI HUH .8 .6 .6
SECCHI DISK TRflHSPftRENCV METERS MEAN 1.5 2.2 2.S HflXIHUH 5.7 2.8 1.3 HI HI HUM 3.1 i.a 2.8
NOTES
<1> TIHE-HEIGIITEO (WERAGE. (2) TRIBUTflRIES
I 29 I tributaries were roughly the same, at 0,24 to 0.52 mg/1. In addition, lake values of Kjeldahl nitrogen exhibited slightly • higher values during the summer, indicative of the increased | phytoplankton biomass.
The nitrogen : phosphorus ratio, calculated as {(TKN + I nitrate nitrogen / total phosphorus ) x 2.21}, indicates potential shifts in the chemical resources important to the primary producers. The annual mean surface in-lake ratio range I was about 23 to 34 : 1 (Table 2) . The bottom stations had a I slightly higher range of values from 34 to 36 : 1, which is due to the higher TKN levels found there, and tributary values were comparable {18 to 35 :1) to surface values. i / These ratios have important implications for the lakes and _ ( their responding biological communities. Values greater than 17 • :1 can be indicative of phosphorus-deficient ponds, while-those " lower can be indicative of nitrogen-deficient ponds (Smith, . 1982). The values from the in-lake stations are quite often • \below the 17:1 standand. This occurs more often in the summer I * i months, which corresponds to periods of low nitrate and ammonia ^^^ llevels. . The low levels of nutrients in Lost Lake / Knopp's Pond support the hypothesis that this is a nutrient-limited system?, The ratios suggest that control may switch between nitrogen and I phosphorus-limitation. Nutrient ratios alone do not provide • conclusive proof of limiting factors, since other potentially limiting factors such as grazing or light availablity may be • contributing. Further, the bioavailability of the phosphorus for | uptake may be decreased by the high iron content of the waters, . since iron is a natural binder ("chelator") of phosphorus _ compounds (Stauffer, 1981) . Another consideration is that the . I level of laboratory detectability for total phosphorus is 10 ug/1 * or less. For calculation and averaging purposes this was always assumed to be 10 ug/1, despite the fact that is may very well be • considerably lower. Therefore, the derived ratios would tend to | overestimate phosphorus availability. Since the ratios are not well below 17 :1 and given the factors discussed above, it seems • likely that phosphorus is the primary control of biological I growth in the water column of this system. It should be realized that the macrophytes are less dependent on water column concentrations and may be subsidizing their growth with uptafce' • from the sediments. Empirically, phosphorus is the most • appropriate target element for control in a lake management program. It is far easier to reduce or eliminate phosphorus inputs than to attempt to control other possible influences. i The temperature of water in Lost Lake / Knopp's Pond _ demonstrated a typical temperate zone seasonal pattern (Figure I 8a-l). The study year started in October with water temperatures • nearly uniform from top to bottom (Figure 8a-c); a condition termed isothermal. This indicates that the pond was in a state • of autumnal turnover (mixing) at the time. Cooling of the pond ~' . I i i 1 Temperature and Dissolved Oxygen Profiles: KP-3 : 10-12/87.
1 f^^^^J 1 Temperature Profile for KP-3: 10-12/87 1 (slafm aot sanplerf oa f 2/17/87 (toe t* ice coorfftw*s) T 1 1 - 2- I 1 3- /I -o- 10/22 Depth(») 4- f | * tf/19 1 3- / t 1 6- 7- / / f Ti 8- i i 1IH 0 5 10 15 teapgratore (Je^rees Celsius) 1 Knopp's Pond Percent Saturation Profile (KP-3); 10-12/87 • (station not sampled on 12/07/87 due to ice conditions) * 0 1 r / 2- I / 1 I „ 4- f ' -a- 10/22 4epthCn) & I -*- 11/19
1 6-
1 8,^^-^-—-^^•^ •
1 10- r • ( * 20 40 60 QQ 100 percent oxygen s^lui 4liwu
- 1
I *" - fr— - ^4H Figure 8b.Temperature and Dissolved Oxygen Profiles; KP-4 : 10-12/87. Ih^B&BM - Temperature Profile Tor KP-4; 10-12/87 i (statio* Mt sampled OB 12/17/87 dw t. ice CMdftitts) 0- — i 1 1
, 1- M i -o- 10/22 Depth (0) 11 -•- 11/19 i 2- II i
,3 1 i 10 15 i 0 5 Te^ert^,» (degrees Cebivs) i Lost Lake Percent Saturation Profile (KP-4); 10-12/87 (station not sampled oa 12/07/87 doe to ice conditions) i 0 . _ " — - •*• i
, 1 -a- 10/22 i / -*- 11/19 depth Cm) f i 2 / i • 3 i 60 80 100 i percent oxygen salui aliun
' i i
32 I Figure 8c. Temperature and Dissolved Oxygen Profiles; KP-5 : 10-12/87.
Temperature Profile for KP-5; 10-12/87
H
DeptfcGa) -a- tO/22 -*- 1!/t9 * 12/17
10 15 Tpmpfratw* Celsivs)
Lost Lake Percent Saturation Profile (KP-5); 10-12/87
depth (m) •Q- 10/22 -»- 11/19
90 - 100 110
33 Figure Bd. Temperature and Dissolved Oxygen Profiles; KP-3 : 1-3/88.
Temperature Profile for KP-3; 1-3/88 (station Mt sampled M 3/14/88 fee t« ic*
1- 2-
3- -Q- 2/25 4- -t- 1/21 5-
6-
7-
8 10 15 Tenpcratve Celstas)
Dissolved Oxygen Saturation Profile for KP-3; 1-3/88
-a- 1/21 -*- 2/25 Depth (m)
100
34 Figure 8e. Temperature and Dissolved Oxygen Profiles; KP-4 : 1-3/38.
Temperature Profile for KP-4; 1-3/88 (statiM Mt sanpfe* M 3/14/88 4*e t* ic*
1 -
-Q- 2/25 •*• 1/21
2-
10 15 Cekws)
Dissolved Oxygen Saturation Profile for KP-4; 1-3/88
0.0
0.5-
1/21 2/25 Deptfa (ra) 1.0 -
40 60 80 100
percent saturattea
35 ^ • 1^m1 Fimin* ftf. • pa: Temperature and Dissolved Oxygen Profiles; KP-5 ; 1-3/88. 1sMfa^J "
Temperature Profile for KP-5; 1-3/88 i (static Mt saa*M •• 3/14/88 *w to i» c«Miti**s) 0- X i J
1 - i \\ OepttO.) -Q- 2/25 i \ -*- 1/21 i 3- \ i 4 _ 0 5 10 15 TMnperatar* (rfe^rwrs Celsws) Dissolved Oxygen Saturation Profile for KP-5; 1-3/88 i
c - p - i 1 - i -o- 1/21 T -*- 2/25 2 Depth (m) ' / i
3- i ---•^r^*'"''^ *-" •
j i 0 20 40 60 80 100 i percent satvatm - i i 36 i I I Figure 8g. Temperature and Dissolved Oxygen Profiles; KP-3 : 4-6/88. I i Temperature Profile for KP-3; 4-6/88 i -o- 4/4 •+• 4/14 i Depth («) •*- 5/9 -*• 5/23 * 6/8 i -Q- 6/20 i i
i Dissolved Oxygen Saturation Profile for KP-3; 4-6/88 i o
i -Q- 4/4 -«- 4/14 •*- 5/9 i •»• 5/23 -* 6/8 i -o 6/20 i i 120 140 i i i 37 Figure 8h. Temperature and Dissolved Oxygen Profiles; KP-4 : 4-6/88.
Temperature Profile for KP-4; 4-6/88
UJU" —i i
OJ5- . i 1 -a- 4/4 • I 1 -*• 4/14 1.0- i i i M , •*- 5/9 / -o- 3/23 Depth 1 * 6/8 i 1.5- il : ' -o- 6/20 2.0- - i J IT i .. .,- —i i . i —* 0 5 10 15 20 25 30
Te«iperatvre (degrees Cefefes)
Dissolved Oxygen Saturation Profile for KP-4; 4-6/88
0.0
-a- 4/4 -«- 4/14 -*- 3/3 -o- 5/23 -* 6/8 -o- 6/20
100 120 I I Figure 8i. Temperature and Dissolved Oxygen Profiles: KP-5 : 4-6/88. I
I Temperature Profile Tor KP-5; 4-6/88 I 0.0 I I I I 10 15 20 30 I (decrees Crisias) I Dissolved Oxygen Saturation Profile for KP-5; 4-6/88 I 0,0 I
I Depth (») I I I 120 I
I 39 I Figure 8j. Temperature and Dissolved Oxygen Profiles; KP-3 : 7-9/88. i i Temperature Profile for KP-3; 7-9/88. i i Depth (») i i i i Dissolved Oxygen Saturation Profile for KP-3; 7-9/88 i i
Depth (m) i i i 6 100 120 140 i situi *\mm i i i 40 i 1 T^ H * .JLjflj Figu re 8k. Temperature and Dissolved Oxygen Profiles; KP-4 : 7-9/88. EF*1 1 *HSfcfll 1 1 Temperature Profile for KP-4; 7-9/88. u -
1 J \ / 1 1- / ' •Q- 7/6 -^ 7/19 D^ttC») i 11 ' J 1 -*- 8/11 1 -o- 8/25 • » 9/8 2- , , 11 ) ! -o- 9/26 1 • 1 11 • ' i 3- 1 0 5 10 15 20 25 30 1 TI€1U|UT If f^IB I € flmmrmmiIQCfl LtJr UVISIBf^mlrn*20
1 Dissolved Oxygen Saturation Profile for KP-4; 7-9/88
0- ti 1 / ] i. 1 Jr 1•
, H* 7/6 1 < 1 \™) \ // / -^ 7/19 r / \ J ->«- 8/11 D^ttC.) \ i f -<^ 8/25 /\ » 9/8 2- 1 i -n- 9/26 ^*" ? J ^->•^-^ / 1 / ^^^ 3- • i • I • i • i i 1•P 0 20 40 60 80 100 120 pm*«t safcratiM 1 '. 1 1 I .1 i Figure 81. Temperature and Dissolved Oxygen Profiles; KP-5 ; 7-9/88.
Temperature Profile for KP-5; 7-9/88
1 -
•a- 7/6 2- -^ 7/19 Depth (n) -»• 8/11 -*• 8/25 * 9/8 -a- 9/26
4-
10 15 20 25 Tenperatort (degrees Celsivs)
Dissolved Oxygen Saturation Profile for KP-5; 7-9/88 o
Dcpttfo)
120 I waters continued in October through December:. Two of the I stations (KP-3, KP-4) were inaccessibl^2^due to poor ice conditions during the December sampling.
Ice cover was present at all stations by the time of the I January sampling. During this period there is a tendency towards inverse stratification as cooler water is perched over warm water (Figure 8d-f). This is due to the greater density of water near I 4 degrees Celsius. By the time of the March sampling the ice was in poor condition (preventing in-pond sampling) . The vernal or spring turnover was marked by mixing of the water column from top I to bottom. With the increasing solar insolation (April through June) , the upper waters of Lost Lake / Knopp' s Pond begin to warm and I become increasingly differentiated from the bottom waters. This is clearly shown for stations KP-3 and KP-5 (Figure 8g-i) , but is not seen at station KP-4. Stratification is less observable at I the KP-4 station because of the shallowness there. The process of seasonal thermal stratification produces a warm upper layer of water (epilimnion) separated from cold bottom waters I (hypolirnnion) by a region of rapid temperature change with depth (thermocline) . By the beginning of June, thermal stratification was well developed in Lost Lake / Knopp's Pond. I During late summer and early fall (July through September) , the warming of the upper waters continued to climb, reaching a seasonal maxima in early August (Figure 8j-l) . The pond began to . I rapidly cool off in late August aided by precipitation (see Hydrologic Budget). The erosion of the summer thermocline was nearly complete by late September. Tjie^ cooling of the water < temperature and the fall rains [would be \expected to lead to the I fall turnover and completion of^the yearly cycle. Oxygen in the water column of Lost Lake / Knopp's Pond I displayed seasonal variation due to water temperature change and biotic activity (Figure 8a^-l) . The amount of oxygen which will dissolve in water is dependent on temperature, dissolved I substances and atmospheric pressure. The relation of the actual oxygen level to the maximum possible concentration is called the percent saturation and/reveals much about pond metabolism. I During the fall, /oxygen levels were a little below saturation; a situation due to the decomposition of organic material either produced or brought into the lakes during the I fall rains (Figure 8^-c). There is an oxygen-poor condition in the bottom waters ofi' KP-3 and to a lesser extent at KP-5. During periods of ice cover in the winter, this oxygen debt became_more severe due to decompositional activity and lack of^communicatiog I with the atmosphere] (Figure ~8d-f) . With ice-out and-t-he-vernal turnover, oxygenrwould be presumed, to be well mixed throughout the water column, I ~/T —X\ ff^ ;>/ I j I I In early spring, the oxygen content in the water is roughly uniform from top to bottom (Figure 8g-i). As the season progresses, two changes occur in the oxygen profile. The first I is the progressive decrease in oxygen levels in the bottom samples as thermal stratification" takes place. Oxygen saturation values are below 20% by the end of June. The second trend is toward greater than 100% oxygen saturation (or super-saturation) I seen at the thermocline. This is caused by oxygen production arising from the photosynthetic activity taking place in the water column. At KP-3, the greatest summer oxygen levels were I seen at depths of about 4 to 5 m. Density differences produced very stable water conditions. Accumulation of particulate matter and remineralization produces localized abundances of nutrients. I The transmission of light to this depth is sufficient to sponsor plant growth. Subsequently, these conditions lead to an accumulation of active phytoplankton. Photosynthetic activity by these algae account for the greater than expected levels of I oxygen. This mid-water or metalimnetic oxygen maxima was also observed to a lesser degree at KP-5. The end of the yearly cycle is indicated by the cooling of the lake terajfjer|£ures (Figure 8j- I 1) . This fall or autumnal overturn led to a more equal distribution of oxygen distribution throughout the water column. ^ I Other chemical parameters monitored on a routine basis included total suspended solids, turbidity, specific conductance, pH, total alkalinity and chloride (Table 2). Chlorophyll a and Secchi disk transparency are discussed in the phytoplankton I section and bacteria is considered separately. Total suspended solids exhibited in-lake surface means of I 2.0^to 2.3 mg/1, with the bottom samples containing higher totals (2.^ to 5.1 mg/1) of particulate matter from sinking, etc. The major tributaries had means of 1.6 to 2.2 mg/1, while Redwater n was greatest at 6.5 mg/1. Some of the particulate material fromnv/1' I this station is undoubtedly iron precipitates. ^ Turbidity is related to the transparency of the water, which I is influenced by the presence of dissolved organic materials and particulate matter, both organic (phytoplankton, detritis) and inorganic (silts and clays). Martin's Pond Brook and the unnamed I tributary had a turbidity of 1.7 to 2.0 JTU. Redwater (KP-7) had less clarity, with a turbidity mean of 11.7 JTU. In the lake, turbidity was about 1.2 JTU on the surface, with greater found at deeper waters. I Specific conductance (conductivity) is an indirect measure of the dissolved solids and chemical fertility of water. Low I fertility is usually indicated by conductivity values less than 100 umhos/cm (USEPA, 1976). The conductivity values of Martin's Pond Brook was 172 umhos/cm. Redwater was lower at 110 umhos/cm, while the unnamed tributary was the lowest at 48 umhos/cm. The I in-lake values ranged from 137 to 154 umhos/cm. From^thls^index, Lost Lake / Knopp's Pond would be considered to have moderate chemical concentrations, but the exact nature of these chem-icals I I n 44 •I I is not determined by/triis measurement. There was a decrease in I conductivity in the/surface waters going from Knopp's Pond to Lost Lake fco—fehe-=out-3ret.Thi s would be expected if there was a dilution effect or/the biota were taking up nutrients from the I waters as they pass by. Total alkalinity provides a measure of the buffering capacity of Lost Lake / Knopp's Pond. Values in-lake were very I consistently in the range of 24.4 to 28.4 mg/1. Martin's Pond Brook was also in this range. The unnamed tributary and Redwater had lower alkalinities 8.0 and 14.3 mg/1, respectively. The I amount of buffering capacity, the ability of the pond to withstand acidic or basic additions without pH change, would be considered fair-to-good. /Subsequently, this lake system is unlikely to experience • the^-rapid acidification observed in some I lakes subjected to "acid rain". \ A \ WA^ The pH of the tributaries, as well as the waters of Lost I Lake / Knopp's Pond.were all essentially acidic, that is, below the midpoint (7.0) of the pH scale. The adjusted annual means ranged from 6.1 to 6.5. The overall range for observations was I 5.6 to 7.6 (Table 2). This are normal levels for a lake and tributary system that is derived from wetlands. Chloride was measured in the Lost Lake / Knopp's Pond I system. Martin's Pond Brook had a concentration of about 30 mg/1. The unnamed tributary had an annual mean of about 5.8 mg/1. The lakes levels were at 24 to 28 mg/1. This is I wou^i^e^expected under non-urbanized conditions (25 mg/1) , -ancL. w.ell_be-3rGw^,the—:limits—recommended^fo-r—dri-n-k-ing-wat'e'f{'2'5,'0~~nEfyiTT~ There is no real problem with chloride in these waters, but the influence of roadsalting is slightly discernible in the winter j 7 I months. valuesUin the Lost Lake / Knopp's Pond system ranged I from a high of 4.57i mg/1 in Redwater, to 0.30-0.33 mg/1 in the other tributaries, and in-lake val.ue.s__of_ 0.09 to 0.14 mg/1. one exception is the high value(J0.39 mg/irh at the deep station I 2"] of KP-3, which is due to the elevated~~cbncentrations from inputs Je""^"'>of groundwater and Redwater. These levels^ of iron are
I 45 p?r ^ tm&"W
f5W—^— Figure 9. Tributary Sampling Sites in the Lost Lake / Knopp's Pond Watershed.
-JL- = Tributary Sampling Site. I KP-T5); other sites were located along the unnamed tributary (KP- I T6) as well as in a kettlehole along Shelter's Road (KP-T7) and one at Duck Pond (KP-T8). Water quality data from these samples are shown in Table 3. I The KP-T1 site was just upstream of the culvert crossing of the outflow of Martin's Pond Brook at Martin's Pond Rd., near Chestnut Hill Rd. The stream channel was relatively uniform and I bottom free of excess organic debris. The stream channel has a partial canopy of overhanging vegetation. The area around this station is a combination of residential land use on the uplands I with surrounding wet lowlands. Flow in the channel at this point was about 1.7 cu. m/min. Following Martin's Pond Brook downstream, the flow meanders I through an extensive wetland. There are several horse pastures along Schoolhouse Rd., some of which abut the stream to the rear. The next tributary sampling station (KP-T2) was established at I the crossing at Lowell Rd. (Rte. 40), where a concrete culvert drains the wetland area. At this point, the stream corridor is more open and grassed. Flow at this point was about 0.5 cu. I m/min in October (the seasonally driest period), and 4.1 cu. m/min. in December, 1988. To the west of this station, there is a tributary to I Martin's Pond Brook which arises in the valley to the south of Gibbet Hill. This tributary crosses Lowell Rd. and enters the wetland area drained via KP-T2. At the north end of the highway I culvert, sampling station KP-T3 was established. Flow was considerable (2.55 cu. m/min.) and the water had a slight odor. Land use in the area above this point is a combination of I agricultural and wetlands. After its crossing with Lowell Rd., Martin's Pond Brook flowjin a southeasterly direction, northeast of Brown Loaf Hill, I and into an extensive wetland area. Another tributary has a confluence with the northern waters in this wetland. Two sampling stations were placed on this stream. The uppermost one I (KP-T4) was located at the crossing on Ames Rd., south of Prospect Hill and about 400 ft to the north of Rte. 119. This culvert had a sluggish flow of 0.34 cu. m/min in December. The flow enters a wetland just below this station. Just upstream of I KP-T4, there was a small pool that had an apparent algal bloom, observed in December. I The next tributary sampling site (KP-T5) was at the Gay Rd. crossing of the southwest tributary ("Prospect Hill") to Martin's Pond Brook (Figure 9) . This was just upstream of the marshy wetland described above, and bordered by scattered residences. I The amount of flow was barely detectable/ measured at 0.02 cu. m/min. in October. I The water chemistry of Martin's Pond Brook changed going I from upstream to downstream. Martin's Pond Brook is the
I 47 Table 3. I TRIBUTARY WATER QUALITY DATA IN THE LOST LAKE / KNOPF'S POND WATERSHED. (FALL 1988K' I STATIONS KP-T1 KP-T2 KP-T2 KP-T3 KP-T4 KP-T5 KP-T6 KP-T7 KP-T8 WTE 12/1/88 10/20/88 12/1/88 12/1/88 12/1/88 10/20/88 10/20/88 10/20/88 10/20/88 PARMETER _ FLOU (CU.M/MIN) 1.70 .51 4.08 2.55 .34 .17 .02 - I TEMPERATURE (DEG. 3.4 7.0 3.0 2.8 4.2 7.1 7.8 11.3 10.5 DIS. OXYGEN (MG/L) 9.4 6.9 9.5 9.2 9.9 8,8 5.1 9.8 6.4, PH (S.U.) 6.2 7.0 6.5 6.6 6.6 7.1 ,6r8~~) 6.9 48 I I combination o/f three tributary flows; the outlet of Martin's Pond I Brook, the Gibbett Hill tributary and the Prospect Hill tributary. /The first two were more important with regard to hydrologic/contributions, with the latter contributing only a I small amoumt of flow. With regard to nutrients inputs, the Gibbet Hilly tributary was^k^an important source of nitrogen and phosphorus. YUsoj^ig^the December chloride concentrations (Cl is biologically Conservative, hence a good indicator of stream I mixing), the concentration at KP-T2 represented the mixing of waters of KP-T1 and KP-T3 (within 3%) . The higher levels of phosphorus, nitrogen, conductivity and chloride at KP-T3 are I probably linked with agricultural land use and associated runoff. Nitrogen levels at the Prospect Hill tributary were somewhat elevated, as well, but phosphorus levels were relatively low. Of the three contributing flows, the Gibbet Hill area was an I important determinant of high nutrient levels in Martin's Pond Brook- The influence of these nutrient sources to Lost Lake is somewhat mitigated by the intervening wetlands between the upper I watershed and the lake. The high density of residences nearer the lake is also a potential source of nutrients to Martin's Pond Brook. Still, it should be noted that the values found at KP-T2 I in December are similar to the average annual levels (Table 2) found at regular station KP-2, located near Lost Lake. Water from the upper reaches of the unnamed tributary (KP- I T6) were also sampled. The steam channel at the Route 119 crossing had little_flow (Q.Og^cu. m/min.). Analyses of this water indicated£^latrvely higlpnitrate and phosphorus levels, ? I high c ondu ct ivTt^a'n'd""hl-gh-ctfl o r i del eve 1 s as compared to the annuar~~me~a~ns(Table 2) . It is possible that these levels are more linked to localized roadside runoff than to upstream land I use. Water from the kettlehole at Laurel Cove (KP-T7) and Duck Pond (KP-T8) exhibited generally better water quality than other I tributaries. The reduced levels of nitrogen and phosphorus are indicative of concentrations in the groundwater around these locations. There is no direct surface connection between these I sites and Knopp's Pond. However there is little doubt that there is a hydrologic connection through the groundwater. When the pond surface water level was lowered in the fall following removal of flashboards, a corresponding drop in elevation was I observed at local kettleholes. The Duck Pond water was very acidic and indicated the influence of the wetlands on the eastern side of that waterbody. Comparing the Duck Pond water with I Redwater shows the influence that passage through the soil and possible local septic systems (fiav^ on the overall water chemistry. In general, the higlTTiron content of these isolated ponds would decrease the export of phosphorus loadings to Lost * I Lake / Knopp's Pond. 1 ' I to I b. Littoral Interstitial Porewater Sampling During June 1988, a series of 2Y littoral interstitial I porewater (LIP) samples were taken/at the locations indicated on Figure 10. The results of the water quality analyses are shown • in Table 4. Total phosphorus /values are in the range of 170 to I 590 ug/1, with a mean of 308 ((+53}/ug/l. These phosphorus values were very variable and likely^to-^reflect a combination of soil conditions (low oxygen, redox potential) and land use. • Functionally, these high levels do not necessarilytranslate ^^_ • directly into groundwater loading rates. Thi^-^s^^ecaifie^ as the """ groundwater moves into the lake it becomes oxygenated. Under • well-oxygenated conditions, some amount of the soluble phosphorus | will rapidly become chemically-bound to iron and precipitate out of solution. „,. .. /tq~^ ^^ •_ A more interpretable^pattern is shown by the nitrogen fractions. Other a~na3:ys~e~§ have shown that it is useful to add the ammonia and nitrate^values together to produce a single value I (designated the "nitrogen index"). This index simply indicates • soluble nitrogen levels in the porewater. The majority of nitrogen leached from septic systems is ammonia. This is • generally converted to .nitrate, depending on the local soil | conditions (moisture, [02]/ pH, etc.) and availability of nitrifying bacteria. For example, effluent NH- is converted to _ NOo in well-oxygenated, basic or neutral soils. However, the • soils around the Lost Lake /Knopp's Pond vicinity are acidic in • nature and the ground water table is high, therefore conversion to nitrate may be less effective. • It is possible to classify LIP sampling sites according to whether this "nitrogen index" (i.e., NH- + NO-) is low (<0.10 • mg/1), medium (0.10-0.50 mg/1) or high T>0.50 mg/1). LIP sites _ • which are classified low are PW-1, 2, 7, 11, 18, and 19 (refer to ™ Figure 10). Medium nitrogen index values were found at sites PW- 3, 4, 5, 6, 10, 12, 15, 17, and 20. High nitrogen index values . I were found at sites PW-8, 9, 13, 14, 16, and 21. If a map of • residential housing density or proximity is considered, there is a general positive correspondence between housing density and • nitrogen index. Given the patterns of seepage established I earlier, this is indirect evidence of septic system e^-fi^ent ^A^dc^-v*- jnay^giLi^fex>'Tte^exjwat-e.3?s-^a£>L'ost Lake / Knopp's Pond. Further, areas of dense filamentous algal growth correspond to areas of I high nitrogen index at two different locations (PW-14, 16). " c. Well Sampling /^t^/^ ' I S^ • Well samples were taken foir an additional measure of groundwater quality. Data fro'm this source is somewhat more • open to interpretation, as the locations of the wells differ with I regard to depth and distance from the lake. However, they can be compared to results fromxthe LIP samples to help estimate groundwater loadings. (j83&er from individual drinking water well5 -"" I sagvp'les were collected in -January 1989 for analysis. The i 50 i I Figure 10. Locations of LIP Sampling Sites in Lost Lake / Knopp's Pond. I I I I I I I I I I I I I I Lost Lake / Knopp's Pond I } cm = 100m I I I Table 4. LOST Lf)KE/W3PP'S POND PQRE-NflTER SflMPLES (06/27-30/88> PHRRMETER UN ITS STflTIOH/UfiLUES Pll-l PM-2 Pll-3 PH-4 PN-5 PH-6 PH-7 PM-8 PI 1-9 PM-10 PW-1 1 PU-12 OHTHO P LOST uru-EyKi-npps pom POPE HHTER SRHPLES PW-13 PN-14 PM-15 Pll-1 6 Pll- 1 7 PM-18 PM-19 PH-20 PH-21 QRTffO P I Bacteria Fecal coliform (FC) and fecal streptococci (ra) were I 'assessed during this study (Table 2). These bacteria come from the digestive tract of all warm-blooded animals, human and non- human, and do not in themselves represent a serious health threat. However, as they are often accompanied by other I pathogens, they are considered indicators of potential health |A hazard if present in substantial numbers. The FC values obtained J£ during this study were below the Massachusetts standards for ^Y^ I contact recreation, which are 200/lOOml for multiple geometric /nD*i means and 400/100 ml for single samples (or 10% of monthly / /* * samples) . Geometric mean^-o^ffn^pond stations wa-s—14 to 23/100 / I ml. The tributaries were higher at 81-197/100 ml-, with Martin's Pond Brook having the fewest counts. Values for fecal streptococci were much higher than coliform I counts, but there are no^bathing standards for streptococci. Geometric means in the pond were 821 to 965/100 ml and the outlet was at 1109/100 ml. The tributaries were even higher, with a I range from 2153 to 4675/100 ml. Potential sources of bacteria in I the latter stations are probably wildlife. Higher values of FS I 53 Figure 11. Well Sampling Sites in the Lost Lake / Knopp's Pond Watershed. •JL- = Well Sampling Site. - Scale = 1 : 25,000 I Table 5. VEIL WATER QUALITY DATA IN THE LOST LAKE / KNOPF'S POND WATERSHED. STATIONS KP-Wl KP-W2 KP-W3 KP-W4 KP-W5 KP-W6 I DATE 01/19/89 01/19/89 01/19/89 01/19/89 01/19/89 01/19/89 PARAMETER PH (S.U.) 5.8 5.4 5.4 5.5 5.7 5.8 I COND. (UMHOS/CM) 212 135 48 238 72 (3491 NB3-N (MG/L) .05 .03 .06 .05 .01 ^fc N03-N (MG/L) .19 .23 1.10 1.56 .16 ( 1 * O i TKN (MG/L) .06 .17 .16 .07 .09 • v f ORTHO-P (UO/L) <10 <10 I 55 I were seen throughout the year, with spring months the time of — least counts. I FC : FS ratios may give some indication of the origin of observed bacteria/ as ratios associated with human-derived • bacterial assemblages are considerably higher than those I associated with non-human sources. THe FC:FS ratio for humans is more than 4,0, whereas the ratio for domestic animals is less s • than 1.0 (Tchobanolgous and Schroder, 1985)« If ratios are -^ I obtained in the ranges of 1 to 2, interpretation is less certain. The confidence of this interpretation is also less sure when FC counts are low (<200/100 ml). This would exclude some of the I routine Lost Lake / Knopp's Pond data from consideration. • However, the tendency towards much greater FS counts in the same sample yield the conclusion that the human septage is not responsible for the observed counts. i Phytoplankton / Phytoplankton, or microscopic algae suspended in the water column, are an important component of aquatic food webs, but may I also impart detectable color, odor, and taste to pond water as • well as a reduction in water clarity. Phytoplankton abundance is often determined by measuring the concentration of chloropKyll a., • the main pigment used in photosynthesis. It is the same pigment J that makes grass and leaves green. Chlorophyll a_ usually represents 0.5 to 2% of total phytoplankton biomass and has been _ correlated with production and standing crop at various levels of • the food web, water clarity, and phosphorus concentration (e.g., • Jones and Bachmann 1976, Oglesby and Schaffner 1978, Hanson and Leggett 1982, Vollenweider 1982). i Measured chlorophyll concentrations in Lost Lake / Knopp's Pond ranged from 0.8 to 4.4 ug/1 at station KP-3, 0.6 to 3.6 ug/1 _ at KP-4S, and from 0.6 to 4.1 ug/1 at station KP-5S. The mean • annual values were 1.9, 1.6 and 2.1 ug/1, respectively. Based on m equations which relate chlorophyll a. concentration to total phosphorus concentrations, expected chlorophyll a. values in the • pond would range from 2.6 to 20.7 ug/1, with a mean value of 9.9 I ug/1- (Jones and Bachman 1976, Oglesby and Schaffner 1978) . For equations and calculations see Appendix. • These predicted values are greater than those observed in Lost Lake / Knopp's Pond. Several possible explanations explain this discrepancy. Most importantly, there is potential .^ I competition for nutrients between the algae and^^/rootegT} —-"^ • aquatic macrophytes. The availability of the total^'phosphorus may be reduced by complexing with organic compounds typical of • wetland drainage. These organic compounds also reduce the | transmission of light due to the brown color of the water and may decrease photosynthetic growth. The influence of high iron _ content in precipitating out phosphorus is likely (Stauffer, I 1981). The observed levels of zooplankton suggest that grazing i™ 56 i I may be important, so that algae" are being cropped fast enough to I prevent complete utilization of the available phosphorus and conversion into algal biomass. I Chlorophyll a values are often considered indicators of the trophic state of a pond. Fitting a pond or reservoir into any classification system is a subjective process with no single parameter capable of fully "defining" the trophic status of a I pond. However, chlorophyll a_ levels are among the more telling parameters. The mean and range of chlorophyll a. values from stations KP-3S, KP-4S and KP-5S correspond to an oligotrophic or I poorly fertilized condition (Wetzel 1983) . This finding should be compared to other parameters, including total phosphorus and total plant biomass, including macrophytes. ,, ^.$1 I Chlorophyll and non-living suspended sol-ras are important determinants of water clarity. Secchi dis« transparency, a measure of water clarity, ranged from 3-A to 5.7 m at KP-3S with I a mean depth of 4.5 m, and 2.8 to 4.3 rrf at KP-5S, also with a mean of 3.5 m (Table 2). -In case -o^/KP-4S, the Secchi disk _ usually touched the bottom sediments, preventing an accurate I assessment of water clarity. The predicted mean value for transparency, based on the observed mean chlorophyll values, was 6.7 m (Oglesby and Schaffner 1978, Vollenweider 1982). I The nature of the phytoplankton community varied with time over the course of the study year and included members from seven major algal divisions. The seasonal patterns of abundance as I cell numbers and as biomass are shown for stations KP 3-5 in Figure I2a-c. I The most persistent taxa were (Bacillariophyceae) , with golden-brown algae {Chrysophytes) , cryptophytes (Cryptophyceae) , green algae (Chlorophyceae) , and blue-green algae (Cyanophyta) being seasonally important. I Euglenoids (Euglenophyta) and dinof lagellates (Pyrrophyta) were never abundant, but the latter was occasionally an important component of total algal biomass due to the very large sizes' of I the individual cells. f Phytoplankton composition and succession differed slightly at each of the three in-lake stations. At Knopp' s Pond (KP-3) , I there were two peaks of diatoms corresponding roughly to the periods of fall and spring turnover. Chrysophytes and cryptophytes were important in winter and early spring, with I secondary maxima in late summer and fall. Blue-greens most abundant from mid-summer to the onset of ice-cover, but were unimportant in terms of biomass. On the other hand, I dinof lagellates were an appreciable part of the summer biomass. In contrast, in Lost Lake (KP-5) the Chrysophytes and cryptophytes were more dominant during the fall and winter and green algae (J*asP important in summer. At the connection between I Lost Lake anoknopp' s Pond (KP-4) , the pattern observed contained I elements of botih KP-3 and KP-5. I 57 Figure 12a. Phytoplankton Cell Numbers and Biomass at Station KP-3. KP-3 PHYTQPLANKTON-CELL NUMBERS 10° T 0 30 60 90 120 150 180 210 240 270 300 330 360 OCT NOV DEC JAN FEB MAR APR MAY JUNE JULY AUG SEPT CD Diatoms • CMorophytes KP-3 PHYTOPLANKTON-BIOMASS El Chrysophytes E3 Cryptophytes D Cyarwpftytes ? 10*, 102, 101. 10° 58 Figure 12b. Phytoplankton Cell Numbers and Biomass at Station KP-4. KP-4 PHYTOPLANKTON-CELL NUMBERS i r I i i Ir 0 30 60 90 120 150 180 210 240 270 300 330 360 OCT NOV DEC JAN FEB MAR APR MAY JUNE JULY AUG SEPT UJ Diatoms • CMorophytes M Dry sophy tes KP-4 PHYTOPLANKTQN-BIOriASS E3 Cryptophytes G Cyanophytes ? JO3 J O ffl O* r——i "i" i r 1 T t v 0 30 60 90 120 150 180 210 240 270 300 330 360 OCT NOV DEC JAN FEB MAR APR MAY JUNE JULY AUG SEPT 59 Figure 12c. Phytoplankton Cell Numbers and Biomass at Station KP-5. KP-5 PHYTQPLANKTON-CELL NUMBERS 10° ( r 30 60 90 1 20 1 80 21 0 240 270 300 330 360 OCT NOV DEC JAN FEE MAR APR MAY JUNE JULY AUG SEPT CQ Diatoms • Chlorophytes M Chnjsophytes 0 Cnjptophytes KP-5 PHYTOPLANKTON-BIOnASS n Cyawohgtes 10° 0 30 60 90 120 150 180 210 240 270 300 330 360 OCT NOV DEC JAN FEB MAR APR MAY JUNE JULY AUG SEPT 60 I The seasonal progression of dominants/was diatoms and I cryptophytes (spring to early summer^, diatoms and blue-green algae (summer through fall), diatoms and chrysophytes (late fall) and flagellated forms during ice-cover. However, the I nature of the phytoplankton in ariy specific pond reflects the response of the plankton community to changing physical, chemical, anci biotic factors which may be specific to that year I ol I Chlorophytes, I Knopp's Pond Macrophyte Composition 0 < *» K1 Kfov? p f«r-i f-v r .a<~pnT*i*^i r"' T^ *n J I o*rT \—^^T" '^r''V * I \O*L' •,* I W V 4 *.* * * ^'iA— V.VWU A SJftl*i, «S. i—-Jj C L-s-^*\v-' J i^ j I k} I I I I I I I I I I I I Scale : 1" = 400 I I I Figure 14b. Distribution of Aquatic Macrophytes in Upper Lost Lake. I I Upper Lost Lake Macrophyte Composition (abbreviations according to Lost,Ls&e"7~ I I I I I EC p ny Cd * V 73 P9 nv- Cd P* V y, MhPs/ I V Ps BG u 3UV J Cd l V EC P.< V UP I * *"F. V / JPSV •wl.js. Pr No v« p. "PFO v FG / -TTX^ «o I v iid /-, ,?3 ^ *>£$*>% No . „ t_J v EC EcFG **/ fPa Hyv Pr v». P^ 'NoPs Eri I Cd lUpN 3F3/ Ps ^^4 ?3 »^i "•*•'•' ' '*lf***£\ mMgm*BV#f&z&\ I Scale ; T = 400' I I I I I Figure 14c. Distribution of Aquatic Macrophytes in Lower Lost Lake. I Lower Lost. Lake Macrophyte Composition I (abbreviations according to Lo^-l I I I I I I I I I I I I I I Scale : J" = I I 65 Tabie 6. List of Aquatic Macrophytes in Lost Lake / Knopp's Pond. I I Abbreviation Plant Species Bluegreen algal mat I Brasenia scnreberi Qetnra alnif olia Ceratophyllum demersum I Cnamaedaphne calyculata Cephalantnus occidentalis I Qiarasp. Decodon verticillatus I Elodea canadensis Heocharis robbinsii Filamentous green algae I Gratiola lutea Lythrum salicaria I Megalodonta beckii Myriopnyilum heteropnyllum MyriophyUum sp. I Najas ftesiiis Nitella flesiiis I Huphar microphyllum Nymphaea odorata I Huphar sp. Pontederia cordata Potamogeton gramineus I Po Polygonum sp. Ps Potamogeton robbinsii I Sa /Sagitaria sp._^— ' Sp ( S. T Typha latif olia I Utricularia purpurea Utricularia vulgaris . I U 1 Utricularia sp. * 1 Utricularia sp. *2 I V Vaiisneria americana Vc Vaccinium sp. I I 66 I I The density of these plants is indicated in Figure 15. . i Macrophyte density was generally 75-100% coverage throughout all of Lost Lake, grading to lower densities only in the deeper portions of Knopp's Pond. An exception to this pattern i the northeast end of the Lost Lake near the boat launch/There, a combination of recent harvesting (summer 1987) and high turbidity led to a decrease in plant coverage. In the deep basin in Knopp's Ponoythere was a cje^lflrlte sharp delineation of i vegetation at a depth of about 4.5 m, probably due to a combination of low light and steep slope. i Wetland species were confined to more natural shorelines of Lost Lake / Knopp's Pond along the length of the lake. The annual fluctuation in water level may restrict establishment of i species to more organic bottom substrates. Theje are two contiguous wetlands of more than a few acres^"(Figure 4) . The wetland at the inlet of Martin's Pond Brook (KP-2) is the more complex and species-rich of the two, and would be expected to i provide better animal habitat. The other wetland is associated i with the deep basin of Knopp's Pond. Zooplankton Zooplankton are of interest beca-trse they represent the i linkage between the bottom of the^ood base and higher trophic levels, namely planktiverous fistt. Zooplankton were sampled twice during the year, at periods corresponding to spring (May) and i summer (July). Samples wer,e taken at stations KP-3 and KP-5. Examination of these/stTrveyJ show that the zooplankton community of Lost Lake / Knopp'vs_Bona includes copepods, rotifers and i cladocerans at moderate densities {Figure 16) . Important copepod taxa included Diaptomus, Mesocyclops, and Epischura. The important members of the cladoceran community included Eubosmina, Ceriodaphnia, Diaphanosoma, and Daphnia species, D_. galeata being i the most prominent. Rotifers were more numerous at the shallower Lost Lake station. i The zooplankters in Knopp's Pond increased in average size from 0.57 to 0.67 mm between May and July. The average size distribution in the summer suggests a healthy zooplankton population, of sufficient size to be useful as a forage food for i fish. In contrast, the average size of a zooplankter in Lost Lake starts out in spring at 0.40 mm but declines to 0.36 mm by July. This summer standing stock is small-sized and is evidence i of more intensive fish predation (Mills et al., 1987) . The differences in zooplankton probably relate to the presence of. i greater macrophytes and associated panfish at the Lost Lake site. Macroinvertebrates i The invertebrates of Lost Lake / Knopp's Pond were i qualitatively sampled by dip net and visual observation. A i 67 Figure 15. Benthic Cover by Aquatic Macrophytes in Lost Lake / Knopp's Pond. i i i i i i i i i i i i i i i i i i 68 i Figure 16a. Zooplankton Size Distribution in Lost Lake / Knopp's Pond. ZOOFLfiNKTQN SIZE DISTRIBUTION IN KNOPP'S POND ON HflY 9,1388 14- 12 10- ZOOPLANKTON LENGTH DISTRIBUTION 8 FOR SAMPLES COLLECTED FROM «• KNOPP'S POND IN 1988 4' PERCENT OF INDIVIDUALS 2 KNOPP'S KNOPP'S m LI!NGTH POND POND ,1 ,2 .3 .4 .5 -S .7 .8 .91.01.11.21.31.41.51.61.71,31,92.0 (MM) 050988 071988 LENGTH CflTcGORY IN MM .1 0.0 0.0 .2 9.8 2.3 .3 15.4 7.8 .4 15.4 10.2 .5 15.4 15.6 .6 5.6 14.1 .7 9.1 12.5 .8 14.7 14.1 .9 5,6 9.4 1.0 2.8 7.0 1.1 2.1 4.7 ZOOPLflNKTOH SIZE DISTRIBUTION IN 1.2 1.4 1.6 KNOPP'S POND ON JULY 19,1988 1.3 1.4 .8 1.4 1.4 0.0 1.5 0.0 0.0 1.6 0.0 0.0 1.7 0.0 0.0 1.8 0.0 0.0 1.9 0.0 0.0 2.0 0.0 0.0 TOTAL 100.0 100.0 MEAN (MM) .57 .67 .1 .2 .3 .4 .5 .6 .7 .8 .91.01.11.21.31.41.51.61.71.81.92.0 LENGTH CflTEGORY IN MM 69 Figure 16b. Zooplankton Size Distribution in Lost Lake / Knopp's Pond. ZOOPLRNKTON SIZE DISTRIBUTION IN LQSTLRKEGNMRY9,I988 22! m IK] 14-hm ZOOPLANKTON LENGTH DISTRIBUTION FOR SAMPLES COLLECTED FROH LOST LAKE IN 1988 VffiVM m I PERCENT OF INDIVIDUALS m LOST LOST .1 .2 .3 -4 .5 .5 .7 .8 .31.01.11.21.31,41.51.61.71.81.92.0 LENGTH LAKE LAKE LENGTH CfllEGflRY IN MM (MM) 050988 071988 .1 13.9 5.4 .2 17.2 26.1 .3 20.5 33.3 .4 14.8 10.8 .5 9.0 9.9 .6 6.6 3.6 .7 9.8 5.4 .8 2.5 1.8 .9 - 1.6 1.8 ZOOPLflHKTOH 3IZE DISTRIBUTION IN 1.0 1.6 1.8 LOST LflKE ON JULY 19,1988 1.1 .8 0.0 1.2 .8 0.0 1.3 0.0 0.0 1. 4 0.0 0.0 1.5 .8 0,0 30 1.6 0.0 0.0 1.7 0.0 0.0 J 1.8 0.0 0.0 20 1.9 0.0 0.0 2.0 0.0 0.0 16 TOTAL 100.0 100.0 MEAN (MM) .40 .36 .2 .3 ,4 .5 .6 .7 .8 .9 i.Oi,n.2!.3M1.5i.61.7I.B1.92.fl LENGTH CRTEGORY IN MM 70 I number of surface dwelling insects were found including water I striders (Gerridae) , and whirligig beetles (Gyrinnidae) . Insect's in the macrophytes included dragonfly nymphs (Anax, Libellu.^^) , damselfly nymphs (Coenagrionidae), and mayflies (Baetidae,A Ephemerellidae) . Other invertebrate inhabitants included I amphipods (Gammaridae) , isopods, snails (Planorbidae), leeches (Erpobdellidae) , oligachaetes (Oligochaeta) . I Of particular interest was the report of a sighting in Knopp's Pond of freshwater jellyfish, Craspedacusta sowerbyi. This hydrozoan is the only species of freshwater jellyfish found I in North America (only 4 species in the world) . Its appeararroe— is relatively unpredictable (reported in Knopp's Pond during the 60's) and its ^cologjp poorly understood. Due to its small size I (about 4 mm) , itf~is~~~easily overlooked. I Fish Records of the Massachusetts Division of Fisheries^and Wildlife (MDFW) on Lost Lake / Knopp's Pond go back to 1911. I Fish mentioned in that report include stocked white perch (Morone americana) , yellow perch (Perca flavescens) , bullhea/d (Ictalurus spp.), pickerel (Esox niger) and sunfish. -$fcQc3c-£?ig ^records indicate stocking of smallmouth bass (Micropterus dolomieu), I largemouth bass (Micropterus salmoides), walleye (Stizostedion vitreum), white and yellow perch, brown bullhead (Ictalurus nebulosa), black crappie (Pomoxis nigromaculatus), and bluegill I (Lepomis macrochirus) (MDFW, 1960). Sampling was conducted by Fish and Wildlife in 1945, when the species list included : yellow perch, pumpkinseed (Lepomis I gibbosus), brown bullhead, chain pickerel, creek chubsucker (Erimyzon oblongus), golden shiner (Notemigonus crysoleucus) , bluegill (Lepomis macrochirus) , black crappie and white perch. I Catch effort was measured at 5.2 fish per gillnet hour; with yellow perch and golden shiner predominating. Further sampling in 1952 found a similar species composition, but included I smallmouth bass and american eel (Anguilla rostrata). Yellow perch and. bluegill were most numerous. _ ).*&* " The pond was "reclaimed" by rotenone, a cti@m±cal used to I eradicate fish in the treated water. This^allows recolonization by surviving fish or by stocked fishrT^'^'mis procedure is commonly used in an attempt to shift a fishery's proportion of I game fish to pan or trash fish'T The^reclamation 'of Lost Lake in 1960 indicated a standing crop-of-"122 Ibs per acre, which consisted mainly of bluegills and pumpkinseeds. Stocking of largemouth bass and chain pickerel was recommended following I reclamation; and some stocking was apparently done. Further fish survey efforts (1962, 1975, 1976) indicated that yellow perch, bluegill, lake chubsucker (Erimyzon succeta), and golden shiners I quickly I I 7 regained prominence. The stocking of trout in sprng and fall _ also became a major factor in development of a "two-story" I • The fish population was most recently sampled by the MDFW in • 1978 using electrofishing and experimental gillnets. Of the 229 | fish collected, eight species were represented in reasonable numbers : largemouth bass, chain pickerel, yellow perch, • bluegill/ pumpkinseed, brown bullhead, golden shiner, and creek I chubsucker. The 1978 survey also identified two species of minor importance; the yellow bullhead (Ictalurus natalis) and the brindled shiner (Notropis bifrenatus). I Analysis of the gamefish sampled indicated that the bass had good growth rates for the young age classes but merely average • growth rates thereafter (MDFW, 1978). Chain pickerel had below | average growth and condition factors. The yellow perch fishery appeared underfished, and they were growing below the state _ average. Pumpkinseed had better than average growth rates, while • bluegills had average growth rates. The brown bullhead fishery • appeared to be in good condition. Recommendations in the 1978 report include stocking of 3,000 trout each spring and 500 trout • each fall. _ • BEG conducted a f-drshery su-rvey on October 21, 1988. This ^ m - consisted of two 300'(sgiLJr and four lOO'-yhet sets. The location | of these nets and hauls is shown on Figure 17. The survey collected 179 fish including brown trout, largemouth bass, chain pickerel, yellow perch, bluegill, pumpkinseed, golden shiner, • brown and yellow bullhead, and lake chubsucker. The numbers and ' average size of these specimens, organized by lake, are shown on Table 7. The dominant species in terms of numbers and biomass • were yellow perch and golden shiner. Trout were restricted to | the Knopp's Pond basin. Growth rates of yellow perch, bluegill, largemouth bass and chain pickerel were considered poor to _ average. Pumpkinseed growth rates were considered to be average I to good. — Observations by EEC personnel during the study year indicate • that fishing is a very popular activity, particularly fishing for I trout in the spring. Summer fishing, primarily for bass, is intensely pursued. Most of the fishing is from boats, as there • are limited shoreline fishing opportunities. Ice fishing I activity was observed during winter visits, but is not very popular, possibly due to the secluded nature of the public parking. Veteran Lost Lake / Knopp's Pond fishermen indicated • that rainbow trout and largemouth bass were the favored game fish • during the open water season. i Sediment Analysis The depth of the ^s aft sediment in Lost Lake / Knopp's Pond I was mapped in August 0/1987.] The sediment layer was measured by i* i Figure 17. Fishery Survey Nets in Lost Lake / Knopp's Pond (10/88) I I I I I I 73 Table 7a. BEC Fishery Survey results from Knopp's Pond. KNOPFS POHD FISH SURVEV. C10/20/88> Ho. HT . Erinyzon sucetta Laka Chub Sucker 5 2,3 1.1 10.0 208 160 H/ft Esox niger Chain Pickerel 7 1.8 6.0 8.0 35? 25? nVG-GWin Ictalurus natal 15 Vail OH Bullhead 11 2.0 12.0 B.? 215 113 H/fl Ictalurus nobulosus Broun Bullhoad 6 2.0 5.0 &.? 2?5 333 H/fl Leponis gibbosus Pi.mpkin Scad 5 -? 1.1 3.0 101 MO nUG-lKKjti Leponis nacrochirus Bluagill 5 .9 1.1 1.0 192 130 POOP. Hicroptarus salnoidcs Largenouth Bass 5 1.8 1.1 e.o 2P6 360 POOR-HUG Hoteni gonus crysol aucas Goldan Shinar 1? 3.6 39.0 3P.6 236 133 H/fl Pftrca f 1 avascans ValloM Parch 21 2.? 20.0 12.0 209 113 POOR- HUG -^jSalrio irutta Brown Trout 2 1.6 295 H/fi TOTI1L 120 22.0kg loo:; 100;; Table 7b. BEC Fishery Survey results from Lost Lake. LOST LfttCE FISH SURVEV. 00/21/88* No. Z OF Z OF hEHH HERH GROHrtl FISH SPECIES COttttOH HfiHE CflUGHT cnuonr TOTOL Ho. rOTflL HT. LENGTH (nn) unrE Eririyzon sucetta Lake Chub Sucker 6.0 2.5 10.0 21.0 26?. 0 11?. 0 H/H ESOK nigar Chain Pickerel 5.0 1.0 8.5 8.3 29?. 0 200.0 POOR Ictalurus natal is V«llou BuUheacI 16.0 2.8 2?.1 23.3 20?. 0 1?5.0 H/fl Leponis gibbosua Punpkin Seed 1-0 1.7 169.0 ftVG-GOOO Leponis nacrochirus Bluagill 2.0 3.1 185.0 POCIR-WG Hicroplarus salnoidas Larganouth Bass 3.0 1.1 5.0 11.6 2?6.0 16?. 0 POOR Hottmigonus crgsolaucas Golden Shiner 6.0 1.7 10.0 11.2 238.0 283.0 H/fl Perca flavescens VelloM Perch 20.0 2.6 31.0 21.6 221.0 130,0 rociR-nw; TOTflL 59.0 12kg 100;: 1002 (Jl I SCUBA divers pushing a metal rod into the bottom to the depth of first refusal. Notes were made about the nature of the I underlying substratum. The depth of the sediments is shown in I Figure 18. The total amount of sediment in the pond was calculated at approximately 1,643,000 cu. m (2,152,000 CY) . For calculations of the sediment totals see Table 8. i \ Sediment samples were taken from the pond at two locations • _ /(Figure 18) via an Ekman benthic dredge in March 1989. The deep I /hole at both Knopp's Pond (KP-3) and Lost Lake (KP-5) were • sampled. The chemical characteristics and physical properties of these samples are shown in Table 9. Overall, the sediment • properties were roughly similar between thev two locations. | £cy2_ C^Av^v^Xy^ Using the criteria developed by the State 'of Massachusetts • (MA DWPC, 1983), the sediment's from the Knopp's Pond site would • be classified-as Category (One) (cleanest classification) for chemical constituents and Type C (high organic content) for physical characteristics. The sediments from the Lost Lake site I hah d highehiher lealead afld^zTUi^eontenadzintnt that placelaced itt inn Category CateorTo^ x'^uA, • (al-^pther heavy metals tested were Category One) . The#£- higher levels^ probably reflect the^Ji-i'g'her^lev.e-l-Sx-o^motorboat and • ad'j"acent automotive activity around Lost Lake. The Lost Lake | sediment was also a Type C sediment, reflecting the contribution of organic material, probably decomposing macrophytes, in the _ formation of these highly organic bottom mucks (gyttja). I Between the two sites, both were high in iron and manganese; particularly in the case of the Lost Lake site. This is • indicative of groundwater influence in the lake system. Due to I this elevated iron content and acidic conditions, liberation of phosphorus from the sediments is probably slight to negligible. • Comparison with other studies Lost Lake / Knopp's Pond has been assessed for water quality • in an informal sense by the observations and data reported in conjunction with the many Fisheries and Wildlife 'surveys (MDFW, ' • 1911; 1960; 1978) . The earliest report (1911) mentions little but | a Secchi disk transparency of 3.1 m (10.3 ft) and a thermocline about 5.8m (19 ft) in August. The aquatic vegetation in Knop's(f Pond was reported as being abundant in flowed areas with the A predominant forms species of Chara, Nuphar spp. and aquatic • grasses. There was no littoral vegetation reported in the deep ("natural") portion of the pond. The 1960 report' does not • describe the pond, but mentions that a portion of the water (13% | by volume) was capable of supporting trout during the critical summer months. The most recent fishery survey, conducted in • 1978, summarized water quality information. The lake's pH was • reported as 6.8 to 7.0 during the summer months. The lake had a buffering capacity of 23 mg/1 and a total hardness of 40 mg/1. The specific conductivity was 120 in the summertime. The volume • of trout water was estimated at 2-4%, during 1976-7 (MDFW, 1978). • i 76 i I Figure 18a. Soft Sediment Depths in Knopp's Pond. I ( All contours given in meters ) I I I I I I 2.O I I I I I I I I I 400 FT I I 77 Figure 18b. Soft Sediment Depths in Upper Lost Lake. I contours given in meters ) I I 78 Figure 18c. Soft Sediment Depths in Lower Lost Lake. ( All contours given in meters ) 1.0 2.0 400 ft 79 I Table 8. Lost Lake / Knopp's Pond Sediment Calculations. Soft Sediment Depth of Upper Lost Lake. _ 23 I Area (ha) Depth Range (m) 2 m m. ™ 5.37 0-1.0 0.5 53,700 26,850 i 4.62 1.0-2.0 1.5 46,200 69, 300 i 4.60 2.0-3.0 2.5 46,000 115,000 '9.07 > 3.0 3.5 90,700 317,450 i 528,600 m3 i Soft Sediment Depth of Lower Lost Lake. 2 3 Area (ha) Depth Range (m) Z m m i 5.62 0-1.0 0.5 56,200 28,100 i 3.93 1.0-2.0 1.5 39,300 58,950 4.18 2.0-3.0 2.5 41,800 104,500 i 9.95 > 3.0 3.5 99,500 348,250 i 539,800 m3 Soft Sediment Depth of Knopp's Pond. i 2 3 Area (ha) Depth Range (m) Z m ^ i 8.63 0-1.0 0.5 86,300 43,150 8.17 1.0-2.0 1.5 81,700 122,550 i 4.03 2.0-3.0 2.5 40,300 100,750 i 8.80 >3.0 3.5 88,000 308,000 574,450 m3 i Sediment Totals : 1,642,850 m' i 2,152,134 CY i 80 I I I TABLE 9 CHEMICAL AND PHYSICAL CHARACTERISTICS I OF LOST LAKE / KNOPP' S POND SEDIMENTS {collected on March 23, 1989) • Parameter (mg/kg unless otherwise noted) KP-3 Cadmium • Chromium Copper I Iron Lead I Manganese • Sine Total Kjeldahl Nitrogen I Total Phosphate i Total Volatile Solids {%) i i i i i i I Lost Lake / Knopp's Pond was surveyed by the Massachusetts Division of Water Pollution Control in June 1911, July 1981, and • June 1985 (MDWPC, 1977; 1981, 1985). Five sampling stations were | established. (Figure 19): at the deep holes in Knopp's Pond and Lost Lake (comparable to KP-3, KP-5 in the EEC study), at the « entrance of Martin's Pond Brook (= KP-2) and the unnamed • tributary (= KP-1), and the outlet (= KP-6). Water quality data m from these surveys are shown in Table 10. Note that the tributaries were only flowing during the 1977 visit, and the I outlet was active only during the 1977 and 1981 surveys. I Summer temperature profiles in Knopp's Pond indicated a • thermocline at about 4 to 5 m with Secchi disk transparencies of J 3 to 5 m (MDWPC, 1977; 1981; 1985). A metalimnetic oxygen maxima was observed in both June 1977 and 1985. The August 1981 profile — did not contain this phenomenon, presumably due to the decreased I transparency (SDT = 3 m) . Oxygen decreased below 6 m and bottom • levels were low. Specific conductance was measured at 110-120 umhos/cm in 1977 and 1981, and was higher (132-158 umhos/cm) in • 1985. The outlet values were comparable with the in-lake surface | samples. Nitrogen values, including ammonia-nitrogen and nitrate- • nitrogen were generally low in the tributaries and lake (£0.25 mg/1) . Total kjeldahl nitrogen did not exceed 1.2 mg/1. Total phosphorus in the epilimnion was generally low (10-40 ug/1) and I increased slightly with depth (the hypolimnion was 20-100 ug/1). • This is probably due to the near-anoxic and reducing conditions found at the bottom. A similar trend was found with iron and • manganese values in Knopp's Pond, presumably for similar reasons. | The phosphorus levels found in these waters indicate a low to moderately fertilized pond. Silica was found at moderate levels _ (1-8 mg/1) in the Lost Lake / Knopp's Pond system. I Other chemical parameters were measured throughout the system. Chloride levels ranged from 15 to 20 rag/1 in the lakes • and tributaries, with the exception of the unnamed tributary (6 I mg/1) . Hardness was measured mostly in the range of 37 to 44 mg/1, with the unnamed tributary slightly lower (22 mg/1). Total • alkalinity was measured at 21 to 36 mg/1. The pH values ranged I from 6.2-6.6 on the bottom to 7.0-7.9 at the surface, indicating the influence of biological productivity. Comparison of these values with the present study does not indicate any significant I changes in these parameters. • The amount of chlorophyll a. found in June -1985 was • relatively low at 1.7 to 2.6 ug/1. The important identified | phytoplankton species were Asterionella, Cyclotella, Dictyosphaerium, Chroomonas, Anacystis, and Euglena (MDWPC, 1977; _ 1985) . Fecal coliform were detected at low levels (<5-10/lOOml) • in the two lakes, and at higher levels elsewhere. • The macrophyte survey conducted by the State in 1977 • identified 10 aquatic and wetland species (MDWPC, 1977) . These | i 82 I Figure 19. Location of Historical Sampling Sites. Lost Lake / Knopp's Pond i i i 8 1 Table 10 1 HISTORIC WAXES QUALITY DATA FROM THE LOST LAZE / KNOPP'S POND SYSTEM 1 sampling Sites (see Figure for locations) 1 Site : 1 i 11111 1 Date code : 2 3 12312 Parameters 1 Depth (m) 0 0 1.5 1.5 1.5 9.0 7.5 Temperature (°C) 23.6 21.9 21.4 15.5 17.4 10.3 9.0 Dissolved oxygen (mg/l) 7.4 9.3 8.2 7.1 6.2 6.2 4.4 1 pH (standard units) 7.2 6.7 7.0 7.1 6.2 6.6 6.4 Conductivity (umhos/cm) 110 146 120 110 133 110 110 1 Total Alkalinity Cmg/l) 30 26 22 25 29 26 21 Hardness (mg/l) 44 41 41 43 39 35 42 Total Susp. Solids (mg/l) 0.0 0.0 0.5 1.0 0.0 1.5 1.0 1 Total Solids (mg/l) soo 100 116 94 94 102 96 KH3-N(mg/l) 0.0 i 0,14 0.0 0.03 0.01 0.06 0.04 1 N03-N(mg/l) 0.1 0.1 0.0 0.1 0.0 0.02 0. i Kjeldahl-NHrogen (mg/l) 0.31 0.55 0.40 0.24 0.44 0.72 0.30 Total phosphate (ug/l) 10 40 30 10 30 20 10 1 Chloride (mg/l) 15 20 19 17 19 14 15 iron (mg/l) 0.04 - 0.05 0.0 - 0.17 0.11 1 Manganese (mg/l) 0.01. - 0.01 0.01 - 0.20 0.24 Total Coliform(*/100ml) 50 10 60 - - - 1 Fecal CoWorm(*/100 ml) 10 <5 _ - - _ Date Codes : 1 = 6/27/77; 2=7/13/81; 3 = 6/25/85. 1 84 1 1 1 1 Table 10 (cont.) 1 Lost Lake / Knopp's Pond Sampling Sites (see Figure for locations) Site: l 2 2 2 2 2 3 1 Date code: 323 1 2 3 1 Parameters 1 Depth (m) 3.0 0 0 1.5 1.1 1.1 0 Temperature (°C) 11.6 26.5 22. 21.5 21.5 20.4 n/a 1i^V Dissolved oxygen (mg/1) /^O-^-J 7.4 8.5 7.5 5.2 5.0 n/a ^~^^\ 1 pH (standard units) 4.4 7.9 6.6 7.2 6.2 6.1 6.5 Conductivity (umhos/cm) 153 310 132 115 110 133 76 1 Total Alkalinity (mg/1) 36 30 22 25 25 25 21 Hardness (mg/1) 31 41 40 39 41 37 32 Total Susp. Solids (mg/1) 0.44 1.0 0.0 0.5 2.5 1.5 2.5 1 Total Solids (mg/1) 133 94 93 106 96 98 63 NH3-N(mg/l) 0.10 0.01 0.05 0.04 0.01 0.05 0.14 0.0 0.10 1 N03-N(mg/l) 0.0 0. 1 0. 1 0.0 0.01 Kjeldahl-Nitrogen (mg/1) 1.2 0.43 0.6 0.63 0.40 0.69 0.40 Total phosphate ( u.g/1 ) n^ 00) 30 40 20 20 40 50 1 Chloride (mg/1) 17 17 20 17 15 19 6 Iron (mg/1) - 0.08 0.13 0.07 1.0 1 Manganese (mg/1) - 0.03 0.01 0.02 0.25 Total Coliform(*/ 100 ml) - 20 30 30 400 1 Fecal Coliforml*/ 100 ml) - <5 <5 S 15 1^H Date Codes : 1 =6/27/77; 2 =7/13/81; 3 = 6/25/85. 1 1 P.* i i Table 10 (cent.) Lost Lake/ Knopp's Pond Sampling Sites (see Figure for locations) Site : 4 5 5 Date code : J 1 2 i Parameters Depth (m) 0 0 0 i Temperature (°C) n/a n/a 26.0 Dissolved oxygen (mg/1) n/a n/a 7.7 i pH (standard units) 6.6 6.3 7.8 i Conductivity (^mhos/cm) 125 120 110 Total Alkalinity ( mg/1) 30 23 27 i Hardness (mg/1) 42 39 41 Total Susp. Solids (mg/1) 1.0 1.5 1.0 i Total Sol ids (mg/1) 156 102 100 i• NH3-N(mg/l) 0.05 0.02 0.01 N03-N (mg/1) 0.0 0.0 0.10 i Kjeldahl- Nitrogen (mg/1) 0.62 0.52 0.45 Total phosphate (ug/1) 170 40 10 i Chloride (mg/1) 16 16 17 Iron (mg/1) 0.5 0.13 0.02 Manganese (mg/1) 0.05 0.10 0.02 i Total Coliform(*/ 100 ml) 400 800 20 Fecal Coliform(*/ 100 ml) 120 100 <5 i Date Codes : 1 = 6/27/77; 2 =7/1 3/81; 3 = 6/25/85. i i 86 i I included: Valisneria americana, Potomogeton spp., Elodea, I Utricularia, Ceratophyllum, Myriophyllum, Nymphaea odorata, Nuphar, and Brasenia. The pattern of density was described as very dense (75-100%) . The dramatic expansion of Myriophyllum spp. is documented in the change in distribution of this plant I between 1977 and the 1985 survey. In 1977, its distribution was limited to the southwestern embayment of Lost Lake. By 1985, it had spread into every cove and was ubiquitous throughout the two I lakes. Other genera noted in the 1985 survey included: Peltandra, Iris, Lemna, Typha and Chara. I " Comparing these results with the BEG study conducted in" \ August 1987; a greater diversity of macrophyte densities was ^ found. A total of 34 plant and algal types were identified in "£he EEC study, with general but not complete agreement with the I previous survey. The important plant genera found in the EEC study were the same as in 1985. However, that BEG survey indicates more "understory" Utricularia in conjunction with I Myriophyllum beds in Lost Lake. The greater number of plants found in the BEG survey is related to seasonal and methodological I differences. Questionnaire Survey I A watershed resident questionnaire was distributed by mail throughout the Lost Lake / Knopp' s Pond watershed with the cooperation of the Lost Lake / Knopp' s Pond Watershed I Association. Questionnaires were also distributed and collected at all three public meetings. Responses to this questionnaire are helpful in evaluating the preferences and practices of potential pond users. Approximately 250 questionnaires were I distributed and 71 responses were completed for a 28% return rate. The majority of the respondees were from Groton and many were lake abutters. Thus, the survey has a high representation I of the abutting residences which are likely to have the greatest influence on the lake. I Approximately 90% of the responding households were permanent year-round residences (Table 11) . Approximately 62% of the houses are within 100 ft of Lost Lake or Knopp' s Pond. The average occupancy rate was 2.7 persons per household. The range I of household occupants was from 1 to 6 persons per dwelling. The usage rate of Lost Lake / Knopp' s Pond was about evenly I divided between daily (32%), weekly (39%) and monthly (29%). The clearly preferred recreational activity was swimming (33%) , followed by boating (20%), canoeing (14%) and fishing (14%). Other recreational activities identified were sailing, skating, I water skiing, bird watching, walking on the shore, and jet- skiing. I Drinking water needs were met by well water (91%), town water I (6%), or bottled (3%). Washing water needs were met by well I 87 I I TABLE 11 I SUMMAR1ARYY OF QUESTIONNAIRE KttSiWNS&'RESPONSES tUFOKR THTatEs m LOST LAKE / KNOPF'S POND STUDY AREA • # responding 71 I % responding 28% • Per sons /household. • Mean 2.7 | Range 1-6 Residency (months/yr) I Mean 10.4 ™ Range 2-12 Property distance from lake (ft) • 0-100' 62% 100-500' 19% • > 500' 19% _ Daily 32% • Weekly 39% • Monthly 29% Preferred activities " | Swimming 33% Boating 20% — Canoeing 14% • Fishing 13% • Sailing 7% Skating 5% ' • Water skiing • 5% I Walking 2% Jet-skiing 1% • Drinking water source On-site well 91% Town water 6% I Store water 3% • Washing water source • On-site well . 89% Town water 9% Store water - 1% Lake water 1% I I 88 I TABLE 11 (Continued) Waste disposal system Tank and leachfield 89% Cesspool 11% On-site disposal system Age (yrs) Mean 17.3 Range 1-40 Distance from lake (ft) 0-50' 18% 50-100' 31% 100-200' 20% > 250' 31% Years since last inspection/pumping Mean 3.0 Range 1-20 On-site wells Type Driven point 44% Artesian 42% Shallow 14% Depth (ft) Mean 93 Range 12-300 Distribution : < 20' 27% 20-50' ' 27% 50-100' 19% > 100' 27% Distance from lake 0-50' 42% 50-100' 14% 100-250' 19% > 250' 25% Years since last testing Mean 3.9 Range 1-12 Well location relative to waste disposal system Upslope 29% Downslope 29% Equal elevation 42% 89Q I TABLE 11 (Continued) — Distance from disposal system from well 0-50' 23% • 50-100' 51% I 100-250' 23% > 250 3% g Problems with either well or disposal system Yes 12% No 88% i Washing machine on the premises Yes 76% • • No 24% | Garbage grinder (disposal) on premises _ Yes 16% • No 84% • Non-phosphate detergent used • Clothes 47% • Dishes 57% Lawn Fertilization i Yes 16% No 84% i i i i i i i i i 90 I water (89%), town water (9%), store water (1%) or lake water I (1%) . : The drinking water wells tended to be a mixture of driven point '(44%), artesian (42%) or shallow jet (14%), The average depth was 93 feet, but many (42%) were shallow (<20 ft). Nearly half were within 50 ft of the lake. The average time since the I well water was tested averaged about three years. Frequent testing seems in order as 30% were located downslope of on-site I sanitary facilities. All the respondees relied on on-site wastewater disposal systems, the majority of which are a tank and leachfield system I (89%) . Alternatively, cesspools were used for disposal of wastes. These septic systems tended to be older, with a mean of 17.3 years and a range of 1 to 40 years. About two-thirds were within 250 ft of the lake, and three-fourths were within 100' of I the lot drinking well. The average time span since the systems have been inspected or pumped was 3.0 years; with a range of less I than 1 to 20 years. A majority of the households have washing machines (76%), while /g^much fewer had garbage grinders (16%) . Of those using I washing machines on the premises, about (47%) used a non- phosphate containing detergent. About 57% of the dishwashing detergents reported were non-phosphate. Lawn fertilization was I practiced by about a sixth of the respondees (16%). I I I I I I I I I I I I I I I HYDROLOGIC BUDGET The hydrology of Lost Lake / Knopp's Pond is determined by I runoff from the watershed, direct precipitation onto the lake system and contributions from groundwater inseepage. Losses to the lake systems occur through outlet flow, evaporation, and I outseepage. The elements of a hydrologic balance are indicated in Figure 21. In the case of Lost Lake / Knopp's Pond, there are no point-source discharges, such as storm drains and no I consumptive withdrawals of lake water. Several different methods were used to estimate surface tributary flow in the Lost Lake / Knopp's Pond system. One I calculation of mean flow was determined by using the total area of the watershed and applying yield coefficients, factors which relate the amount of flow to the unit area. The yield I coefficients of Sopper and Lull (1970) suggested a mean flow ranging from 7.6 to 11.4 cu. m/min.(4.5-6.7 cfs). A second method uses the expected runoff production, which in New England averages between 51-61 cm/yr or 20"-24"/yr {Higgins and Colonell, I 1971) . if this amount of runoff is derived from the Lost Lake / Knopp's Pond watershed (1157.4 ha) and gains from direct precipitation and evaporative losses are included, then flows of I 11.7 to 13.9 cu.m/min. (6.9-8.2 cfs) are expected. [For details on all hydraulic calculations see the Appendix.] I Several factors need to be taken into consideration when evaluating these estimates. These factors include topography, soils and underlying deposits, and prevailing land use. The Lost Lake / Knopp's Pond watershed is characterized by glacial till I drumlins and large wetlands to the west. These features would suggest more runoff into the swamps and streams. In addition groundwater movement would be intercepted by these large surface I water features. As the wetland/streams approach Lost Lake, they coalesce into more well-defined channels and stream valleys. In general, these characteristics would decrease the amount of groundwater recharge in these areas. The wetlands are also the I sites of increased evapotranspiration during the summer months. Closer to the lakes, steep slopes characterized by eskers and I kettleholes are prominent and the soils tend to be very permeable. In these areas, located mostly to the south and east of the lakes, groundwater recharge would be expected to occur. I Land use (predominantly forested with low density residential and agricultural) would further encourage recharge. Groundwater seepage to the lake should be greater along these shorelines. Located in these areas are numerous kettleholes, which are I seasonally flooded. During the study year, water levels in these ponds around Lost Lake / Knopp's Pond fluctuated roughly in relation to the lake surface elevation, suggesting a hydrologic I linkage through the groundwater. I Figure 20. Schematic Lake Hydrologic Budget. LAKE WATER BUDGET PRECIPITATION EVAPORATION j > TRIBUTARY INFLOWS WITHDRAWALS DIRECT RUNOFF CHANGE IN STORAGE SURFACE OUTFLOW 0} POINT-SOURCE DISCHARGES GROUNDWATER INFLOWS GROUNDWATER OUTFLOWS Taken from United States Environmental Protection Agency (1988) The Lake and Reservoir Restoration Guidance Manual. Washington, D.C. I Actual measurements of water inputs to Lost Lake / Knopp's I Pond included assessment of the flow in the inlet tributaries (Figure 1, Table 2), determination of direct precipitation inputs, and estimates of groundwater seepage. Each of these I hydrologic inputs is considered in detail below. The time-weighted average flow of the major tributary (Martin's Pond Brook or KP-2) was 3.8 cu. m/min.(2.2 cfs) . This I stream drains much of the northwestern portion of the watershed (Figure 5) . This tributary was flowing throughout the study year. Flow in this input was variable (flow range was 0.3 to I 11.6 cu.m/min) and was notable for its brown color, due to its association with wetlands. Other tributary flows included the unnamed stream (KP-1) I entering the southwest corner of Lost Lake and the emergent seepage flow from the Duck Pond region or Redwater (KP-7) . The time-weighted averages of these streams were rated at 1.6 and 0.3 I cu.m/min, respectively. The small tributary (KP-1) was the most variable flow source, with a range of flows from 0 to 4.9 cu.m/min. (0-2.9 cfs). It was active from December 1987 through early June, 1988, after which it dried up. Redwater (KP-7) was I sampled from March 1988 through the end of the study year. Although not observed earlier, it is apparently a year-round feature, based on local residents' reports and the groundwater I derivation of its flow. The range of flows for this input was 0.1 to 0.5 cu.m/min. (0.06-0.3 cfs). I Precipitation data reported to the National Oceanic and Atmospheric Administration (NOAA) is routinely tabulated and provided to requesting parties. Using precipitation data (NOAA 1987;1988) for nearby (5.1 miles away) Dunstable MA, a total of I precipitation of 98 cm (38.6") was measured for the period October 1987 to September 1988 (Table 12). Since the pond area is 83.0 ha, the average contribution of direct precipitation is I estimated at 1.5 cu.m/min. (0.9 cfs). The total for the study year is compared to the long-term, thirty-year average (NOAA, 1986) in Figure 21. I The measured outflow as surface water averaged 5.2 cu. m/min. (3.1 cfs) This seemed rather small when compared to other estimates of watershed flows (see above). A careful inspection I of field notes revealed that at least two of the sampling days (4/18/88; 5/23/88) occurred when the flashboards were installed in the spring and the lake system was filling. Since there was a I somewhat dry spring, this filling probably took longer than usual, it is possible that the outflow mean may be underestimated. I The fall sampling schedule terminated in September before the I flashboards (2 ft head) were removed from the outlet I I 95 i Table 12. Precipitation Data for the Groton, MA area. i* i PRECIPITATION IN THE GROTON AREA (OCTOBER 1987-SEPTEMBER 1988) (data from Dunstable, MA unless noted; Source: NOAA, 1987/1988) 1 Month Precipitation (cm) ~" October 7.01 * 1 November 8.00 December 5.56 | January 6.86 • February 9.14 " March 1 April 8.66 May 11.66 - 1 June 4.90 July 13.59 ' August 10.13 • September 5.82 Study Year Total =97.68 1 * data incomplete from Dunstable; _. i i i 96 i Figure 21. Comparison of Study Year Precipitation to Thirty Year Average. H 30 yr avg. D Study Yr Oct Nov Dec Jan Feb Mar Apr May Jun Ju! Aug Sep Months 97 I structure. The amount of storage provided by these flashboards is considerable (>400 ac-ft). If this storage component is I calculated at an additional flow, it would be equal to 0.95 • cu.m/min (0.56 cfs). Evaporation was calculated at 1.1 cu. m/min. {0.65 cfs) based on an average evaporative rate of 69 • cm/yr. {Higgins and Colonell, 1971) . The long axis of Lost Lake | (its fetch) would provide good opportunity for wind action and increased evaporation. . Groundwater was assessed by three different methodologies : ™ direct observation with seepage meters, calculation via Darcy's equation, and as the difference of totaled inputs and outputs. • Seepage was measured in meters placed around the periphery of the I lake (Figure 22a,b) following the procedure of Mitchell et al. (1988) . Seepage was measured during a period in August - • September 1987 and in June 1988. In addition, a permanently I installed seepage meter (seepage meter "0" in Figure 22b) was monitored three times during the summer. Seepage into the lake was measured at 1.28 to 1.76 cu.m/min, • while seepage out of the lake was measured at 0.06 to 0.14 cu.m/min. The net groundwater fluxes measured were 1.23 to 1.62 • cu. m/min. (0.72 to 0.95 cfs), respectively. There was a | seasonal difference in the pattern of seepage (Figure 22a,b,), which may be related to differences in the groundwater table • elevation or level of the lake. In late August 1987 (when the I groundwater table would be expected to be lower) most of the seepage into the lake system is located along the southern shoreline and around Knopp's Pond (Figure 22a). There was some I limited outseepage in southeast corner of Springy Pond, moving in I the general direction of Carmichael Swamp. This direction is the historical route of drainage during some post-glacial periods • (Geoscience, 1983). It is also possible that groundwater from • the southeastern Knopp's Pond watershed is lost to the Spectacle Pond system, due to low summer groundwater tables caused by intensive pumping (BEG, 1987). In contrast, according to seepage I measurements made in June 1988, Lost Lake received more influx of B groundwater, notably along the eastern shoreline. Outseepage occurred at the northeast corner of upper Lost Lake, by the • outflow (Figure 22b). Overall, a median value of 1.52 cu. m/min | (0.89 cfs) was assumed as the net seepage rate. For sample calculations and derivation of seepage totals see Appendix. _ The general configurations of groundwater table elevation • contours are given in Figure 23, along with the expected direction of groundwater movement. Note that in'the northwest • portion of the watershed, groundwater contours lead to discharge I into surface hydrologic features, such as Martin's Pond Brook. As the contours approach Lost Lake, they indicate a rather broad • based seepage movement with the greatest hydraulic gradient along • the western and southern shoreline. Groundwater movement from the east has a lesser hydraulic gradient. Along the southeast corner of the watershed, the groundwater table contours "flatten • out". Here, the direction of groundwater flow is less H predictable and could go either toward or away from Knopp's Pond. i 96 I IFigure 22a. Location of Seepage Meters in Lost Lake / Knopp's Pond August 20-26, 1957 I Composite Seepage Rates = 0 to 10 l/sq.m/day 51-52 I = 10 to 20 l/sq.m/day = 20 to 40 l/sq-m/day I s > 40 l/sq.m/day I I 43-44 I I I 39-40 I 37-38 I 15-16 I 33-34 I 13-14 I Lost Lake / Knopp's Pond I 1 CIQ = 100 m I 27-38 I I 99 I Figure 22b.Location of Seepage Meters in Lost Lake / Knopp's Pond I on June 27-30, 1956 Composite Seepage Rates I —» = 0 to 10 l/sq.m/day = 10 to 20 t/sq.m/day = 20 to 40 l/sq.m/day I = > 40 1/sq.m/day f JY I 23-24 I I I 35-36 I I I I 5-6 I I Lost Lake / Knopp's Ponci I 1 cm= 100m I I I CO I I I Figure 23. Groundwater Table Topography in the I Lost Lake / Knopp's Pond Watershed. I I N I Scale = 1 : 25,000 T I I I I I I I I Groundwater Table Elevations I in feet above sea level. I Dashed lines indicate surface drainages. I Arrows indicate preferred movement of groundwater. I (Taken from IEP, 1983) I \J I Another method of calculating groundwater involving Darcy's equation uses information about the soil types, water table, and • the area of potential seepage to estimate fluxes. Flow is a I product of the hydraulic conductivity, hydraulic gradient and cross-sectional area perpendicular to the groundwater flow • direction (Q - K * I * A). Hydraulic conductivity can be | estimated from the published transmissivity values (Geoscience, 1983) . If an average saturated zone thickness of 25 ft is _ assumed (calculated from depth of bedrock and water table I elevations), and transmissivity is equal to 15,000 cu. ft/day; ™ hydraulic conductivity is equal to 60 cu. ft/day/sq. ft. Alternatively, conductivity may be estimated by the soil type. I There are several soil types in the Lost Lake / Knopp's Pond I watershed (see Soils and Geology section), but Quonset loamy sands are predominant around most of the lake's shoreline. • Estimated hydraulic permeability for this soil type can be I greater than 40 ft /day (SCS, 1988). A range of 40 to 60 cu ft/day/ sq. ft. provides a reasonable set of values for calculation purposes. I The hydraulic gradient was estimated at several locations along the shoreline by looking at the change in groundwater • contours as a function of linear distance. This analysis was | limited to areas surrounding the lakes, as more distant gradients were not included due to the interception of groundwater by H surface streams. The average hydraulic gradient generated was • 0.02 ft/ft. The length of potential seepage was assumed to be approximately 20,000 ft, due to the long, irregular shoreline. The depth of the seepage into the lake was assumed to be the I depth of the saturated zone or 25 ft. Calculating groundwater I flow using Darcy's equation produces an estimate of 3.10 to 4.64 cu. m/min. (1.82-2.73 cfs) . This is two to three times the amount estimated by direct measurement using the seepage meters. i The last way to calculate groundwater is the most direct, — simply add all the inputs and subtract them from the summed • outputs and the difference is groundwater. This assumes that the • hydraulic budget is balanced (inputs = outputs) for the study year. This may not be a valid assumption, as lake level • fluctuated throughout the water year and (through natural and | man-made actions) did not return to its initial starting conditions. However, if the water outputs are corrected for the _ amount of storage, the lake is assumed to be roughly in balance I during the study year. Assuming a balanced water budget * groundwater can be estimated by difference. The total inputs and outputs of Lost Lake / Knopp's Pond were/ respectively, 8.65 cu. I m/min. (5.1 cfs) to 7.35 cu. m/min. (4.3 cfs). The difference I between the two is 1.3 cu. m/min. (0.8 cfs). This estimate indicate that there is more net recharge of the groundwater table below the lakes that discharge into the lake. i There are several potential reasons why the three estimates _ disagree. Seepage meters may underestimate groundwater seepage, I since they are restricted to water depths of 3 m or less and • cannot measure deep inflow. This may or may not be a limitation i 102 I due to deep bottom mucks which greatly reduce the amount of I seepage due to low permeability characteristics. Secondly, seepage meters are placed around the periphery of the lake at regular intervals, but may miss localized "hot spots" of I significant inflow. Alternatively, the measurement of groundwater by calculation may be an overestimate. Use of a 25 ft zone to estimate the I depth of groundwater contribution along the major zones of groundwater seepage (south, west) may be unrealistic. At these shorelines in question, the bottom slopes rapidly to 5 to 7 ft of I water depth (Figure 2} . At the toe of this slope, soft sediment depths are generally greater than 3 m (10 ft) of organic muck (Figure 18), which is likely to impede seepage. If water was not able to enter the lake it is possible that this water would I "underflow" the lake, moving in a generally northern direction towards Whitney Pond. If, for example, the area of groundwater seepage was restricted to a depth of 7 ft instead of 25 ft, the I estimate of groundwater flow based on calculations becomes 0.87 to 1.30 cu.m/min (0.51- 0.76 cfs). This is much more comparable I to the totals estimated by the seepage meters. The distinction between categories of groundwater and surface tributaries is also often indistinct. For example, Redwater is derived from seepage that briefly surfaces before it enters I Knopp's Pond. Thus, this water could be accounted in both groundwater calculations and surface measurements. If so, it would be included twice in the water budget, and the I contributions of groundwater slightly overestimated. The same is true to a smaller extent of KP-1 and KP-2, since it is difficult to estimate how much of the calculated groundwater they I intercept. Finally, there is the possibility of error in the overall water balance, such that estimation by difference is inaccurate. I Surface measurement of outflow did not take into account any diffuse seepage through the dam. There was some indirect evidence of this seepage as there was some observed leakage and I the ground below the dam was often waterlogged. However, this did not seem to be a large amount. Evaporation may also be underestimated, since water moving toward the lake system pops up in numerous kettleholes along the groundwater movement front. I With each kettlehole basin, the functional water surface for potential evapotranspiration is increased over the conservative I estimate of just using the Lost Lake / Knopp's Pond surface area. TO summarize, the range of calculations for groundwater influx include those for direct seepage measurements, 1.28 - 1.76 cu. m/min; calculated from soil maps, 3.10 - 4.64 cu. m/min; and I estimated by difference, -1.30 cu m/min. The mean value for these three methods is 1.36 cu. m/min. However, the method of calculating by difference seems too low. For the purposes of I calculation a groundwater flux of 1,52 cu. m/ min was assumed. This is the median of the observed seepage meter range and is I comparable to the estimate produced by assumption of a I 103 i i i TABLE 13 HYDROLOGIC BUDGET FOR LOST LAKE / KNOPF'S POND i Inputs cu.m/min % of Total Unnamed tributary (KP-1) 1.6 18.6 i Martin's Pond Brook (KP-2) 3.8 43.9 "Redwater" (KP-7) 0.25 2.9 Precipitation (Direct Input) 1.5 17.3 i Groundwater (Direct Input) 1.5 • 17.3 Totals 8.65 100.0 i Outputs i Outlet (KP-6) 5.2 60.1 Evaporation • 1.1 12.7 i Groundwater (outseepage) 0.1 1.2 Storage 0.95 11.0 Diffuse Losses 1.3 15.0 1 Totals 8.65 100.0 Years Days I^B Detention Time 0.405 ' 148 1 Response Time 0.086-0.258 94-157 1 1 1 104 1 I groundwater contribution depth of 7 ft instead of 25 ft. The I value of this number is tempered by the factors discussed above. It seems likely that some amount of potential groundwater underflows the lake, moving to the north. This is important to consider if dredging is proposed, as removal of sediment depth I may lead to increased groundwater influx. Based on the average inflows through the system in 1987-88 I (8.65 cu. m/min.)/ the detention time for water in Lost Lake / Knopp's Pond is 0.405 yr, or 148 days. Basically the water in the lake is exchanged or flushed 2 and one/half times a year. I For calculations of detention times see Appendix. The response time, calculated according to Dillon and Rigler (1975) indicates how much detention time is needed for the I potential impact of an episodic pollutant load to be completely realized. For Lost Lake / Knopp's Pond, the response time ranges from 0.086 to 0.258 yr, or 94 to 157 days. These values are well I within the range for detention time for Lost Lake / Knopp's Pond. This suggests that most if not all of the impact of a pollutant will be felt by the system before it passes out. Pollutants will I have sufficient time to evoke a biological response. There is some variation associated with the pollutant response time, and it should not be strictly applied in a management content. However, it is clear that nutrients and other substances entering I Lost Lake / Knopp's Pond in the summer experience sufficient residence time to have maximal impact on water quality of the system. The clearest expression of this biological response is I the luxuriant macrophyte growths. I I I I I I I I I 0 06 I I I NUTRIENT BUDGET I Phosphorus A phosphorus budget takes into account the loadings of I nutrient entering a lake ("sources") and the fates of those nutrients ("sinks"). The elements of a phosphorus budget are schematically shown in Figure 24. I Export coefficients for phosphorus can be used in conjunction with land use data to estimate the load generation in the Lost Lake / Knopp's Pond watershed. The best of a wealth of I literature values for areal phosphorus export have been summarized by Reckhow et al. (1980), and values can be selected from the range presented after evaluation of specific watershed I traits such as vegetative features, soil types, and housing density. Chosen export coefficients and corresponding justification I are presented in Table 14. The coefficients, corresponding land areas and the results of their multiplication are given in Table 15. Based on this analysis 655 kg of phosphorus are generated in I the watershed each year. Not all of this phosphorus reaches Lost Lake / Knopp's Pond, as some of the load passes through the soil and is adsorbed or complexed. The detention of water in wetlands I will diminish phosphorus export (via biological uptake), as well. Another modeling approach to quantifying inputs involves use of empirical equations which rely on in-lake concentrations and I hydrological parameters of the system to estimate the load to the lake. A set of five equations was applied to the Lost Lake / Knopp's Pond system (Table 16). Appropriate values for I corresponding variables and the calculated phosphorus loads are presented in Table 17. Loads ranged from 185 to 587 kg P/yr, with most equations predicting from 220 to 260 kg/yr. It should be recognized that these models are applicable to a large number I of lakes, and do not presume to describe the behavior in any one lake (Wetzel, 1983). One assumption of the models rarely approached in real lakes is that of complete and instantaneous I mixing of the nutrient load throughout the lake. ' The complex morphometry of Lost Lake / Knopp's Pond and the limited mixing of waters between the two basins are two complicating factors. Therefore the results from these models should be applied with I caution. Vollenweider (1968) established loading criteria based on I system morphology and hydrology; a phosphorus load of less than 174 kg/yr would be considered permissible under this scheme, I while a load in excess of 349 kg/yr would be deemed critical. I 07 Figure 24. Schematic Lake Phosphorus Budget. LAKE PHOSPHORUS BUDGET PRECIPITATION & DUSTFALL MIGRANT WATERFOWL TRIBUTARY INFLOWS WITHDRAWALS DIRECT RUNOFF CHANGE IN STORAGE SURFACE OUTFLOW o POINT-SOURCE 00 DISCHARGES GROUNDWATER INFLOWS GROUNDWATER OUTFLOWS & SHORELINE SEPTIC TANKS NET SEDIMENTATION Taken from : United States Environmental Protection Agency (1988) The Lake and Reservoir Restoration Guidance Manual. Washington, D.C. I I I I TABLE 14 I NUTRIENT EXPORT COEFFICIENTS FOR LAND USES AND OTHER SOURCES IN THE WATERSHED OF LOST LAKE / KHOPP'S POND. EXPORT COEFFICIENT (KG/HA/TC) I NUTRIENT SOURCE NITROGEN PHOSPHORUS SELECTION CRITERIA LAND OSE: Forest 2.46 .21 Median value selected. Residential Light Density 50 1.10 Large lots, maintained buffer areas. I Crowded lots, poor facilities maintenance, Medium Density 97 1.91 Coni&ercial 50 1.10 Median value selected Agricultural Pasturage 8.65 1.50 Includes fallow & active grazing. I Tilled Areas 9.00 2.24 Isolated fields, median value applied. Orchards 14.30 .91 Mixed agricultural designation. Recreation/Park 5.15 .81 Seasonally heavy use at beach. Golf Course 8.65 1.5 Heavy fertilizer use. I Open 33 .48 Abandoned fielos, power easements, etc. Wetland 46 .21 Median value selected. Vatw (w/o LL/KP) 0 0 No net export assumed. OTHER SOURCES: Atmospheric Deposition 9.16 .24 Mostly forested with resid, & agric. mix. I Groundwater Localized importance Aquatic Birds LOO .14 Assume density of 0.50 bird/yr/ha I Internal Loading Anoxic area a: deep holes. I I I I I I I I 09 I I I TABLE 15 I NUTRIENT LOAD GENERATION BY SOURCES IN THE WATERSHED OF LOST LAKE / KNOPF'S POND. I EXPORT COEFFICIENT (KG/HA/YR) LOAD GENERATED (KG/YR) nJJUWnJJUJ HKLn NUTRIENT SOURCE (HECTARES) NITROGEN PHOSPHORUS NITROGEN PHOSPHORUS LAND USE: I Forest 509.1 2.46 .21 1252 107 Residential Light Density 235.9 5.50 1.10 1297 259 Medium Density 20.4 9.97 1.91 203 39 I Commercial 3.4 5.50 1.10 19 4 Agricultural Pasturage 69 8.65 1.50 597 i04 Tilled Areas 12.3 9.00 2.24 111 28 Orchards 26.9 14.30 .91 385 24 I Recreation/Park 3.7 5.15 .81 19 3 Golf course 10.1 8.65 1.5 87 15 Open 67.9 3.33 .48 226 33 Wetland 58.7 2.46 .21 144 12 I OTHEWateR SOURCESr Cw/o: LL/KP). 15.4 Atmosoheric Deposition 82.5 9.16 .24 756 20 Groundvater * 959 93 Waterfovi (kg/bird/yr) 42 1,00 .14 42 6 I Internal Loading * 0 16 TOTAL 4845 ess I I I I I I i I I I I I I TABLE 16 EQUATIONS AND VARIABLES FOR DERIVING PHOSPHORUS I LOAD ESTIMATES FROM IN-LAKE CONCENTRATIONS Kirchner & Dillon, 1975 (K-D) TP=Total P as ug/1 in spring TP=L(1-R) /Z(F) 2 I L=TP(Z) (F)/ (1-Rp) L=P load as mg P/m /yr Vollenweider, 1975 (V) Z=mean depth as m TP=L/(Z)(S+F) I L=TP(2)(S+F) F=flushing/yr Chapra, 1975 (C) Pin=Flow weighted average input I TP=L(1-R)/(Z) (F) concentration of phosphorus L=TP(Z) (F) /(1-R) Pout=Flow weighted average Larsen & Mercier, 1975 (L-M) output concentration of phosphorus I TP=L(1-R L-TP(Z) S=effluent TP/influent TP I Jones & Bachmann, 1976 (J-B) qs=Areal water load=Z{F) m/yr TP=0.84 L/{2) (0.65+F) L=TP(Z)(0.65+F)/0.84 Vs=Settling velocity=Z(S) m I R=Retention coefficient (phosphorus) =(P in - P out)/P in I Rp=Retention coefficient (water load) I =Vs/(Vs+qs) (Vs defined - 13.2) I I I I I I I I I TABLE 17 PHOSPHORUS LOAD TO LOST LAKE / KNOPF'S POND • BASED ON MODELS EMPLOYING IN-LAKE CONCENTRATIONS * Variable Parameter Value I TP [ug/1] 40 Z [m] - 1.8 • F [yr } 2.41 § Pin 81 Pout 47 S=P out/P in 0.58 • qs=Z (F) [m/yr] 4.47 " R=(P in - P out)/P in 0.42 Rp=13.2/13.2+qs 0.74 • RLM=1/(1+F ) 0.39 • 2 Predicted Load (g/m /yr) • By Each Model I K-D 0.705 V 0.219 • C 0.306 • L-M 0.290 J-B 0.267 • Predicted Load (kg/yr) | By Each Model K-D 585 V 182 I C 254 L-M 241 J-B 221 I Vollenweider Criteria I Permissible Load g/m2/yr 0.21 I kg/yr 174 Critical Load i g/m2/yr 0.42 _ kg/yr 349 • i i I Of the five models considered above, all five predict a current I loading above the permissible and one predicts loading exceeding the critical load. This suggests that the mesotrophic conditions prevalent in Lost Lake / Knopp's Pond could easily worsen with I little additional phosphorus. The most reliable approach involves direct measurement, although not all inputs are amenable to this approach. A I combination of empirical data or export coefficients was therefore applied. The mass flow of total phosphorus past monitored stations was calculated based on sample concentrations I (Table 18) with appropriate time- and flow-weighting. The biggest source of total phosphorus was Martin's Pond Brook (KP- 2), followed by the unnamed tributary (KP-1) and Redwater (KP-7). I In addition to the surface water inputs, groundwater, atmospheric deposition and wildlife, principally waterfowl, must also be considered. Using a value for phosphorus deposition I (0.24 kg P/ha) representative of forest-rural land use area (Scheuler, 1987), a direct precipitation-induced load of 20 kg/yr is calculated. Wildlife inputs are hard to quantify, but a I density of 1/2 bird equivalent per hectare of lake (a bird equivalent equals a year long residence by a waterfowl) is assumed since this lake is not a major nesting/feeding ground and is frequented by solitary wading birds. Given an average figure I of 0.135 kg P/bird/yr; this density adds another 6 kg phosphorus altogether (Brezonik, 1973). For calculations of deposition and I wildlife inputs see Appendix. The amount of phosphorus entering via groundwater was not directly monitored, but can be estimated from available information. Since phosphorus is quickly adsorbed in horizontal I groundwater movements across the landscape, we restricted focus to the potential contribution of septic systems to the phosphorus budget of Lost Lake / Knopp's Pond. The amount of phosphorus I generated from this portion of the watershed can be estimated using residential unit density, average unit population, average residence time and per capita phosphorus loading values. Most of I these factors can be fine-tuned to the Lost Lake / Knopp's Pond situation by adjusting the factors according to the survey responses from the lake abutters. The predicted estimate of phosphorus entering the lakes ranges from 46.2 to 138.8 kg/yr, I with a median figure of 93 kp P/yr. The assumptions and calculations are explicitly stated in the Appendix. I An alternative way of estimating the amount of phosphorus loading from the groundwater is to multiply the estimated seepage to the lakes (see Hydrologic Budget) by the concentration of I phosphorus in the littoral groundwater. The amount of seepage entering the lake was estimated to be 1.52 cu. m/min. As an I estimate of phosphorus moving through the groundwater, the mean I I I I TABLE 18 I NITROGEN AND PHOSPHORUS MASS FLCW IN THE LOST LAKE / KNGPP'S POND SYSTEM • MASS FLOW PAST GIVEN STATION (KG/YR) I PARaiSETER KP-1 KP-2 KP-7 KP-6 Total Phosphorus 64 175 8 170 Orthophosphorus 11 67 4 41 I Ammonia Nitrogen 14 174 10 152 Nitrate Nitrogen 40 466 3 368 I Total Kjeldahl Nitrogen 359 1041 33 1224 Total Nitrogen 399 1507 36 1592 I all yearly totals are both time- and flow-weighted, • i i i i i i i i i i I orthophosphorus concentration in the LIP samples {Table 4) was I used. With these values a total of 47 kg P/yr was calculated. This is a rough approximation, since orthophosphate is only part of the total soluble phosphorus fraction and the LIP samples were only made once during the study year. However, this value agrees I with the lower value predicted by the per capita calculation so the two figures are within the same range. Since the estimate made on the per capita basis seems to be reasonable, and I represents potential loadings it was decided to adopt this value. If the median value of the range or 93 kg P/yr is used, this constitutes about 24% of the total phosphorus loading to the I lake. The amount of phosphorus entering the water column via remineralization in the bottom sediments was calculated. Oxygen I levels in the bottom waters of the deep basin in Knopp' s Pond were sufficiently low enough to produce the reducing conditions required for phosphorus release to the water column. In I addition, there was a trend of increasing phosphorus with depth such as would be expected with phosphorus release from sediments. The amount of phosphorus realized from this benthic I remineralization was estimated to be 16 kg/yr. For calculations involving the remineralization of benthic phosphorus see the Appendix. I A summary of the phosphorus inputs is shown in Table 19. The inputs contributed from all the various sources considered above account for a loading of 382 kg/yr. Comparing this value to the I amount of phosphorus leaving the outlet (170 kg/yr), there is a sizeable discrepancy (212 kg) ; indicating that Lost Lake / Knopp's Pond is a sink for phosphorus (55% retention). This is not too surprising given the very dense coverage of macrophytes I on the lakes' bottoms. Some of this retained phosphorus could be passed out as organic particles later in the year when the water level was lowered, but is more likely to be deposited within the I lake. This store of phosphorus in the sediments provides the nutrient basis for future macrophytes. I The "standing stock" of phosphorus in the water column is estimated at 182 kg P (in-lake concentration x lake volume x flushing rate). Thus/ it appears the lake.is removing some of the phosphorus inputs before they are fully mixed into the lake I waters. Wetland extensions near the outfall of Martin's Pond Brook may reduce nutrient inputs. The dense macrophyte cover may act as a living "biofilter" removing phosphorus from groundwater I as it passes through root systems. The biological availability of phosphorus may be reduced by complexation with tannic and humic compounds. Phosphorus can also leave the lake in seasonal outseepage, be removed as caught fish or settle out as particles. I The high levels of iron in the lake waters would promote the I formation of iron-phosphorus complexes that either precipitate or I I D I I TABLE 19 I NUTRIENT LOADS TO LOST LAKE / KNOPF'S POND BASED ON EMPIRICAL DATA AND SELECTED EXPORT COEFFICIENTS I Total Phosphorus Total Nitrogen % of % of I kg/yr total kg/yr total Source I Unnamed Tributary (KP-1) 64 16.8 399 10.8 Martin's Pond Brook (KP-2 175 45.8 1507 40.7 I "Redwater" (KP-7) 8 2.1 36 1.1 Ground Water I (Direct Input) 93 24.3 959 25.9 Atmospheric Deposition I (Direct Input) 20 5.2 756 20.4 Bird Inputs (Direct Input) 1.6 42 1.1 I Internal Load (Anoxic Loading) 16 4.2 0.0 0.0 I Total 382 100 3,699 100 I I I I I I I I I are not available to sponsor algal growth. In other words, the I value of 382 kg P/yr represents the sum of potential phosphorus loadings to the lake, but one which may not be realized, due to the factors discussed above. Empirically, it provides a useful index of the lake's overall trophic state. Further, the I quantification of the relative importance of the various sources can be used to formulate cost-effective management options. I The levels of phosphorus found in Lost Lake / Knopp's Pond are important for the overall trophic level of the lake. The waters of Lost Lake / Knopp's Pond are generally clear with minor summer algal blooms. It would be classified as a mesotrophic I lake based on its nutrient status. However, its in situ biological characteristics do not show the full impact of the nutrient loadings {perhaps due to the mitigating factors I discussed above). However, reduction of phosphorus inputs is still a key to the maintenance and improvement of water quality I in Lost Lake / Knopp's Pond. Nitrogen I Derivation of the nitrogen budget was approached in the same manner as the phosphorus budget. Lack of analogous equations for calculating nitrogen loads from in-lake concentrations precluded I the use of that method. Export coefficients and resulting loads are given in Tables 14 and 15. Mass flow of three nitrogen forms and total nitrogen past monitored stations are presented in Table I 18. A breakdown of the total nitrogen loadings by the source is shown in Table 19. From export coefficients it is estimated that 4,845 kg of I nitrogen are generated in the Lost Lake / Knopp's Pond watershed each year. The fraction of this load reaching the pond is largely dependent on the form of nitrogen generated; nitrates I move rapidly through sandy soils, while organic nitrogen (TKN - ammonia nitrogen) is more likely to arrive from surface runoff. Organic nitrogen fractions (particularly TKN) are the most I important form of nitrogen in the system. With the addition of atmospheric deposition, wildlife inputs and groundwater contributions, the total nitrogen load to Lost I Lake / Knopp's Pond was 3,699 kg/yr. This range is comparable for the amount of predicted nitrogen generated by the watershed. The amount of nitrogen retained by the watershed is approximately I 24%. The measured output of total nitrogen was decidedly lower at 1592 kg/yr. Thus the lake apparently retains a portion of the nitrogen going through the system (57%). However, unlike phosphorus which has no atmospheric form, nitrogen can be lost to I the system by bacterial metabolism and production of nitrogen I gas. I I I I 7 I On an annual basis, the magnitude of the nitrogen load suggests that phosphorus will be in relatively shorter supply for I plant growth in Lost Lake / Knopp's Pond. Therefore, phosphorus • would be the logical target of lake management actions. This does not mean that nitrogen should be ignored. The tendency of • nitrogen sources to be linked to other pollutants suggests that | an overall management program should address nitrogen inputs. It is unlikely, however, that control of nitrogen alone (if _ possible) would yield any detectable benefits in Lost Lake / • Knopp's Pond. i* i i i i i i i i i i i i i i I I I DIAGNOSTIC SUMMARY I Lost Lake / Knopp's Pond in Groton, MA is situated in a moderately-large watershed which occupies most of the southeastern corner of the town. The surface watershed is marked I by glacial features including drumlins, eskers and kettlehole depressions. Land use in the watershed is primarily forested (49%) with residential (25%) and agricultural (11%) applications also important. The watershed is a critical influence on the I nature of Lost Lake / Knopp's Pond due to its hydrologic and nutrient contributions. The effect of lakeside properties are manifested 'cfSsg.^-in the form of septic system effluent and - I diffuse runoff. Lost Lake / Knopp' s Pond is a continuous waterbody formed by I three natural ponds enhanced by flowage from the impoundment of tributary streams. The major tributary is Martin's Pond Brook, which provides 44% of the water in the lake system on an annual basis.- An unnamed tributary entering at the southwest corner of I Lost Lake and Redwater contribute 19% and 3%, respectively. Groundwater and direct precipitation are equally important at 17% and account for the remainder. Total flow through the system was I msasjur^ed at 8.65 cu. m/min. Flow through the system results in a/slow) flushing, with a mean hydraulic retention time of 148 I On an annual basis, phosphorus is in relatively shorter supply than nitrogen in Lost Lake / Knopp's Pond. Phosphorus enters the lake system through a number of sources including the I tributaries : Martin's Pond Brook, 46%; the unnamed tributary, 17%; and Redwater 2%. Other sources include benthic remineralization (4%) , aquatic wildlife (2%) , and atmospheric I deposition (5%) . Groundwater and the loadings from adjacent septic systems account for the remaining 24%. The total phosphorus load to Lost Lake / Knopp's Pond is 382 kilograms per year. Nitrogen loadings are much higher, approximately 9 times I greater, but phosphorus still remains the element of best control for water quality. I The overall nutrient status of Lost Lake / Knopp's Pond would be considered mesotrophic, based on its chemical and biological characteristics. Growths of aquatic macrophytes are extensive with very high densities and biomass accumulations I occurring at depths less than 14 feet throughout the lake system. The extent of this growth interferes with surface recreation and shoreline fishing by mid-summer. In addition, the "two-tiered" I fishery, while moderately productive, is overcrowded with less desirable pan and rough fish. Presently, swimming, fishing, and I boating are the most popular activities on the lake system. I 19 I There are summer hypolimnetic oxygen deficits in the deepest holes. While limited in water volume affected, these anoxic I conditions may present some stress to fish life there, I particularly stocked trout which gravitate to these colder waters in summer. The water transparency is generally good during the • summer months. Phytoplankton levels are less prevalent than I expected, probably due to competition for nutrients with the macrophytes and lowered bioavailability of phosphorus due to _ cornplexing with iron. • Lost Lake / Knopp's Pond provides a popular and accessible water resource for Groton. The phosphorus load entering the lake • system is above a desirable level, and factors within the I watershed will need to be managed to improve water quality. However, good environmental practices and reduction of the • nutrient inputs by shoreline residents are equally essential for I any management plan that hopes to increase recreational function to the lake system. i i i i i i i i i i i 20 PART II. FEASIBILITY ASSESSMENT 121 I I I EVALUATION OF MANAGEMENT OPTIONS I Available Techniques The number of techniques available for lake and watershed I management is not limitless (Table 20) . However, the potential combination of these techniques and level of their application do result in a great number of possible management approaches. Each lake 'must be considered a unique system, thus an effective I restoration and management program must be tailored to a specific waterbody (Wagner and Oglesby, 1984). I Improvement to conditions in Lost Lake / Knopp' s Pond will be linked to control of nutrient inputs to the lake combined with localized treatment of nuisance water weeds. Since this can be I done in many ways, there exists many potential lake management options that need to be evaluated. The lake and watershed characteristics of Lost Lake / Knopp's Pond and nature of problems there immediately eliminate some alternatives from I further consideration, however. These easily rejected alternatives are considered below. I Dredging refers to the removal of sediment from the bottom of a lake or pond. Dredging is an effective means to reduce macrophyte infestation by removal of existing plants and organic sediment layers and helps limit future growth by increasing I depth. The importance of the additional depth is in the reduction of lightc^peHetrance^to the bottom dwelling plants/ this limits or severely reduces their growth. It is a very expensive lake restoration technique, but one. which is relatively long- lasting. In the case of Lost Lake, dredging is not recommended as a means of plant elimination due to the large amount of I sediment to be removed, coupled with the absence of good dewatering basins adjacent to the lake. For example, to dredge Lost Lake of the sediment necessary to control plant populations via light limitation (dredging to depths greater than 3.5 m) I would require the removal of > 70.0,000 cu. m at a cost likely to exceed $7,000,000. Even if the majority of the project expense is covered by the t^assachu^se"f-trs~Cl'ean~Lak'e's^Progr.am, the size of I Groton's portion (25%) is likely to severel"y~~Eest the town's financial resources. Other more economical ways to deal with the plant biomass need to be considered. I Biocidal chemicals and dyes are inappropriate here. Biocides are considered by EEC to be an ecologically unsound management tool in all but a very restricted class of applications. Recent I literature on lake management does not even consider biocides as management tools (e.g., Cooke et al., 1986). The low level of phytoplankton, the popularity of swimming areas, and the local I wells and downstream public water supply (Whitney Pond), are factors arguing against application of herbicides. I 23 I I TABLE 20 I LAKE JRESTQRA3TCN AND CPTCCNS Technique Descriptive Notes I A. In-Lake Level Actions performed within a water body. I 1. Dredging Removal of sediments under wet or dry conditions, I 2. Macrophyte Harvesting Removal of plants by mechanical means. 3. Biocidal Chemical Treatment Addition of inhibitory substances And Dyes intended to eliminate target species. I 4. Water Level Control Flooding or drying of target areas to aid or eliminate target species. I 5. Hypolimnetic Aeration Mechanical maintenance of oxygen levels Or Destratification and prevention of stagnation. I 6. Hypolimnetic Withdrawal Removal of oxygen poor, nutrient rich bottom waters. I 7. Bottom Sealing/Sediment Physical or chemical obstruction of Treatment plant growth, nutrient exchange, and/or oxygen uptake at the sediment-water I interface. 8. Nutrient Inactivation Chemical comlexing and precipitation of undesirable dissolved substances. I 9. Dilution And Flushing Increased flow to minimize retention of undesirable materials. I 10. Biomanipulation/Habitat Facilitation of biological interactions Management to alter ecosystem processes. I B, Watershed Level Approaches applied to the _drainage area of a water body. I 1. Zoning/Land Use Planning Management of land to minimize deleterious iirpacts on water. I 2. Stormwater/Wastewater Routing of pollutant flows away from a Diversion target water body. 3. Detention Basin Use Lengthening of time of travel for I And Maintenance pollutant flows and facilitation of natural purification processes. I I I I I TABLE 20 (continued) I 4. Provision Of Sanitary Community level collection and treatment Sewers of wastewater to remove pollutants. I 5. Maintenance And Upgrade Proper operation of localized systems Of On-Site Disposal Systems and maximal treatment of wastewater to remove pollutants. I 6. Agricultural Best Application of techniques in forestry, Management Practices animal, and crop science intended to I minimize impacts. 7. Bank And Slope Stabilization Erosion control to reduce inputs I of sediment and related substances. 8. Increased Street Sweeping Frequent removal of potential runoff pollutants from roads. I 9. Behavioral Modifications Actions by individuals. a. Use Of Non-Phosphate Elimination of a major wastewater I Detergents. phosphorus source. b. Eliminate Garbage Grinders Reduce load to treatment system. c. Minimize Lawn Fertilization Reduce potential for nutrient loading I to a water body. d. Restrict Motorboat Activity Reduce wave action, vertical mixing, and I sediment resuspension. e. Eliminate Illegal Dumping Reduce organic pollution, sediment loads I and potentially toxic inputs to a water I body. I I I I I I Hypolimnetic aeration of^ciestratification is the mechanical introduction of oxygen or warmer waters into the bottom layers in I an attempt to increase t'he oxygen level of those waters. While • Lost Lake / Knopp's Pond^doe's have oxygen poor waters in the deeper basins, this constitutes a minor portion of the total lake • volume. The amount of anoxic phosphorus remineralization that | oxygenation would prevent is a small proportion of the total phosphorus budget (see Nutrient Budget section). The costs _ associated with either this option or hypolimnetic withdrawal I (selective removal of bottom waters) would be high due to the ^ need for sophisticated aeration technology and the distance from the outlet. Neither is justifiable in terms of the improvements • imparted to the lake system by elimination of this small portion I of the phosphorus budget. Nutrient inactivation could be used to help prevent I remobilization of phosphorus from the bottom sediments. The technique relies on the use of aluminum salts to induce t ^ phosphorus precipitation from the water column or binding ^ • (inactivation} in the sediments. This technique usually requ-arres • repetitive applications to be effective. This treatment i-smost successful for lakes in which the tributary nutrient inputs have • been much reduced and the recycling of nutrients from/phosphorus- | rich sediments continues to supply large amounts of^the growth- limiting factor (Cooke et al., 1986). However,^the water column — is low on dissolved phosphorus, application of alum would provide I little quantitative reduction. Further, the high iron content of ™ the waters already seems to be very effectively locking up some of the incoming phosphorus biochemically .*-It makes little sense • to substitute an expensive, repetitive chemical treatment to I produce the same sequestering of phosphorus that is being done by natural means. ^ $4- IJUXfl'~6wve. •&£%? • Dilution and flushing are also not viable solutions for Lost Lake / Knopp's Pond. While it is possible that the pond's eutrophication problems would be lessened from quicker movement I of its waters, particularly in the summer, other sources of good • quality water are not easily diverted or obtainable for such a scheme, /^specially since water levels are seasonally quite low ^^" • in thi's part of Groton, This solution is simply not practical | for Lost Lake / Knopp's Pond. Biomanipulation is an attempt to influence lake conditions I through the removal or introduction of more favorable species. • It is a new and still largely experimental technique, and not without risk to the ecosystem (Wagner/ 1985) . The nature of • conditions at Lost Lake / Knopp's Pond and its nearness to . I downstream aquatic resources do not make it a good candidate for an attempt at biotic manipulation. Replacement of the nuisance • macrophytes with more desirable types is uncertain and a loss of I their functional utility may result. The macrophyte community is already sufficiently diverse and constitutes good habitat cover types, though atpundesirablyfhigh densities. While long range /^ • i i I improvement in Lost Lake / Knopp' s Pond might be aimed at improving the recreational fishery, the basic conditions under I which Lost Lake / Knopp's Pond exists would not be changed by _ biotic introductions. Biomanipulation attempts are therefore not I recommended at this stage. Often the most effective lake management options are those which are applicable to a lake's watershed and not directly to i the lake. This is also the case for the Lost Lake / Knopp's Pond watershed area. Of course, not all watershed options make sense for the Lost Lake / Knopp's Pond system. Considering these i watershed options {Table 20) , it is apparent that several of these management techniques would be inappropriate or ineffective for Lost Lake / Knopp's Pond. i Stormwater diversion is not an issue here, since no storm drains are routed into the lake. This is beneficial for the protection of water quality in Lost Lake / Knopp's Pond, and i development of storm drainage leading directly into the lake should be discouraged. i The use of a detention basin to increase the time available for sedimentation and purification is not very useful in this watershed. The existing wetlands in the western portion of the Martin's Pond Brook watershed already provide natural detention" i along the watercourse. There is also a good quality wetland at the confluence of Martin's Pond Brook with Lost Lake. The other two tributaries do not pass through wetlands but there is little i land near their confluences that is available for this purpose. Their nutrient and sediment loads do not justify the expenses of creating detention basins in upstream channels or at the lake. For these reasons, the use of a detention basin is not i recommended means for improvement of tributary water quality. Bank and slope stabilization is of importance to lakeside i residents to prevent unwanted sediments from filling the basin. There is noJXpresent danger of substantial bank collapse, although there are locations along the shoreline that suffer the effects of wave action and variable water levels. However, these i problems areas can best be addressed by individual lot owners and is ultimately their responsibility. Information about the proper stabilization cribbing and shoreline protection can be included i in a general educational package about good environmental practices (see section on environmental practices). Increasing I the-frequency of street sweeping in the watershed is a moot /^ i point, as the town of Groton does not own a street sweeper. ) Thus, at a first cut, the following techniques are eliminated /va from further consideration: dredging, biocides, hypolimnetic s/r i withdrawal or aeration, nutrient inactivation, dilution and - flushing, biomanipulation, stormwater diversion, detention basins, bank and slope stabilization, and increased street . i sweeping. A critical examin.ation of the remaining techniques ^ 1 i will further reduce the number of viable options. i 27 I Evaluation of Viable Techniques The techniques considered at this stage are ones that are somewhat appropriate for improving conditions in Lost Lake / Knopp's Pond, but may_Jpe__r_ejje.c.ted__for_riot being as effective as • other alternatives t^r^prohlbitive incolTb for the final results. I These techniques include macrophyte-haxvesting, water level control, bottom barriers, zoning bylaws, building of sanitary sewers, septic system improvements, agricultural best management I practices, and various behavorial modifications. Whenever • possible, it is preferable to spend dollars to reduce or remove factors leading to lake degradation rather than merely treat lake conditions in isolation. i In Lost Lake / Knopp's Pond there is extensive coverage of • the bottom by macrophytes (Figure 14} . These macrophytes area, \A^\^ I suite of submerged species such as Myriophyllum, whicKj:iasr~~~ proliferated throughout much of the littoral area. Reduction or elimination of selected macrophyte beds would be beneficial. I This can be achieved through harvesting or the use of bottom I barriers. Macrophyte harvesting refers to the direct mechanical removal | of nuisance aquatic vegetation to permit the desired use of the water or littoral area. Basic types of harvesting include mowing, tillage and suction and diver-operated dredging and hydraulic washing equipment (Cooke et al., 1986). The conventional (and least costly) method used is the cutting and harvesting of the summer growth of macrophytes. }&&&£recently a -*^ • more selective method referred to as hydro-raking has been | popularized. Briefly, harvesting has the advantages of immediate removal • of the nuisance plants and the nutrients they contain, which are subject to release upon plant senescence, as well as direct targeting of problem areas with little hazard to other biota. M The harvesting activities do not preclude concurrent lake use in I other areas and are usually acceptable to local lake ordinances. Further, the operating costs are less expensive than many other • forms of physical control. . I The disadvantages of harvesting need to be considered as well. These include the labor and energy to remove the cut I vegetation from the lake. Effective harvesting is usually B delayed until the nuisance plant biomass is maximal and carbohydrate storage in the roots has already peaked (producing • the following year's growth) . A high cost can be associated with | mobilization (just getting machine to and from the lake), and there are operational costs and delays connected with machinery _ breakdown. Obstacles in the water may prevent conventional I harvesting in those areas, and only a relatively small area can * be treated by an individual machine. Conventional harvesting is effective at removing present vegetation but does little to • i i I affect the roots and seed beds which are the sources of future I macrophyte problems. A program of macrophyte harvesting was conducted in Lost Lake in 1987 using both a conventional harvester and a hydro-rake. I The effectiveness of this harvesting program seems to have been variable; with some residents quite pleased with the harvest, while others were disappointed with the overall results and the I debris associated with the process. In any case, state .^g^S^i^g^-are not available for routine harvesting, so the annual costs of harvesting would have to be borne by the town of I Groton, Again, it makes sense to consider restoration options which do not have ar/long-term need for annual operation dollars. Given these considerations, another method of plant removal I worth considering is the deployment of bottom barriers. A bottom barrier consists of a layer of synthetic material that is laid directly over the bottom and weeds. It effectively compresses I and shades aquatic macrophytes to suppress their growth. The screen is positioned in shallow water by hand, but a diver may be necessary for application to deeper waters. It must be weighted I (e.g., cinder blocks) or staked down. A major advantage of these screens is that they are reusable. They can be retrieved from the water, washed, dried and stored for use in succeeding years. With proper care, five seasons of use can be expected. Given the I costs associated with this short-term management^plan and the • desirability of shoreline areas e-£—gel .at Ij^QJ^y^bpen water, this technique does provide localized benefits and should be I considered. Water level control is another way in which macrophyte density can be lessened, through a program of drawdown of the I water surface. This requires .some way in which the lake can be drained to a selective depth. The present dam structure lacks the means to withdraw water. However, the nature of the dam and I its elevation relative to the downstream channel may allow installation of either a pond underdrain or siphoning equipment. Once such an improvement is made, the operating costs associated I with this option are small, an important consideration for any long-term lake management tool. sources of nutrient loading need to be regulated as I well. "An important nutrient source is the effluent from septic systems in the watershed, particularly along the shorelines of the two lakes. The lack of sanitary sewer lines in these areas i dictates that these systems are the only viable way of getting rid of human wastes. Since the performance of these systems is very variable depending on the condition and frequency of inspection/maintenance, this area is one in which particular I attention should be paid. An educational program designed to explain the relationship between septic systems and the lakers advisable, including the importance of upgrading and maintaining I septic systems on a regular schedule. I I 29 i Zoning and land use planning is often a very effective way to guide and control the extent and density of development in a I watershed. In the case of Lost Lake / Knopp's Pond, considerable B non-developed land exists in portions of the watershed. If not carefully managed, changes in land use and accompanying • infrastructure will have negative impacts on future lake water | quality. Therefore, revisions to existing zoning bylaws or strengthening of local ordinances designed to protect aquatic _ resources are potential lake restoration options. Watershed I control thus becomes a means to reduce or mitigate existing or ™ future loadings to the lake, or even prevent these loadings by placing restrictions on development. • Development of a sanitary sewer in the Lost Lake / Knopp's Pond watershed is needed due to the recent extension and • intensification of residential development around the Lost Lake / I Knopp's Pond area. At this time, sanitary sewer lines are just being introduced into the major thoroughfares of Groton Center (Figure 25). Future expansion of this system to the Lost Lake / I Knopp's Pond area is recommended. This represents the best • technical solution for eliminating loadings due to on-site septic systems. However, sewer extension can encourage further • development in the area, so careful planning is necessary or the | t, potential benefit to Lost Lake / Knopp's Pond will be lost or o^ "• ^diminished. Funding for this type of improvement falls outside « V jthe jurisdiction of the Clean Lakes Program and must be sought I *£;. ^elsewhere in state funding programs (Division of Water Pollution * (control, Construction Grants Program). Therefore, while extension of a sanitary sewer is a recommended option, it serves —"" B little purpose to consider it in detail in this report. Further^ | discussion of restoration options will be restricted to those } y items for which Clean Lakes funding is possible. — ^ • Agricultural best management practices are needed in those portions of the watershed having land uses devoted to that purpose. Agriculture has a high potential for negative lake I effects, due to export of sediments and nutrients during runoff • events. Good environmental stewardship of the land is required to minimize these impacts on lake water quality. • In a similar fashion, environmentally-wise practices need to be exercised by lakeshore residents, as their impact on the lake is _ so immediate. These practices should include the use of I phosphorus-free detergents, reduction in lawn fertilization, B removal of hazardous materials from adjacent kettleholes, etc. These all help reduce non-point sources of pollution going into B the Lost Lake / Knopp's Pond. | Thus, afterxfeviewing viable techniques and in light of the • characteristic's of the system, the recommended in-lake management B techniques (Ts) macrophyte reduction through bottom barriers and water level control. At the watershed level the preferred options include: zoning/by-law revision, maintenance and upgrade B of septic systems, agricultural best management practices, and behavorial modifications of watershed occupants. i 130 i PROPOSED B' DIA. SANITARY SEWERS WITH MANHOLES __, INTERCEPTOR SEWER TO BE CONSTRUCTED UNDER 70/30 GRANT PROGRAM GROTON CENTER SEWER DISTRICT GROTOH, I I I I I 132 I I I WATER LEVEL CONTROL I Elements of a Drawdown Program Lost Lake / Knopp's Pond is an appropriate site to use water I level to control the distribution and abundance of nuisance macrophytes. A winter drawdown of lake level would expose sediments underlying areas of high macrophyte density, and making the plants vulnerable to the combined effects of freezing, I dessication, and ice-scour. Several of the major nuisance species in Lost Lake / Knopp's Pond, including Myriophyllum, Potamogeton robbinsii, Utricularia, Nuphar and Nymphaea, have I been shown to usually decrease in abundance following a winter drawdown (Cooke et al., 1986). However, not all macrophytes are negatively affected by a winter drawdown. The response of one of I the other major macrophyte species, Elodea, has been more variable. Given the existing coverage of vunerable plant species t seems worthwhile to exgerimgnt—Sfith an experimental drawdown I and evaluate the results. The Lost Lake / Knopp's Pond Dam is a concrete and earthen embankment approximately 10' high and 80' long. (Hayden et al., I 1980) . The exact date of construction is not known, but it is likely that this structure was built in the period 1900-1920. In the center of the dam is a 7 ft concrete spillway discharging into a downstream pool which passes under Lost Lake Drive via a I 4.5 ft metal culvert and into Whitney Pond. There is no other regulating outlet on the spillway. A general plan, taken from I the Dam Safety Inspection Report of 1980 is shown- in Figure 26. Use of the present spillway to conduct a drawcJown provides limited removal of water. The spillway has a normal summer I (recreational) pool elevation of 21-4 ft (above SL) which can be lowered to 212 ft by removal of (twb^wooden flashboards. The normal procedure is for a representative of Grotonwoods Camp to install the flashboards in the spring and remove them in the I fall. Thus, the vertical extent of this drawdown is limited to 0.67 m {2 ft), which exposes only a small portion of the pond I bottom and very little of the macrophyte beds. While no draining device exists, there is the topographical possibility of removing more water passively. The elevation of I the streambed at the toe of the dam is 2Q6+_ ft. The streambed elevation declines further away from the dam, with an invert elevation of 200+_ ft on the culvert on Lost Lake Drive (Hayden et al., 1980) . This means there is a minimum head difference of 6 I ft near the dam, which increases downstream. With a 1.6 m (5 ft) drawdown about 55% of the bottom would be exposed. This would include most of southern and northeastern Lost Lake, and I northwest Knopp's Pond, save the middle channels where the groundwater and streamflow would^tendT) Two ways in which the I 133 ELEVATION VIEW HLflN VltW (WOUND f—^ _ SURFACE"^ /- 1 (j '.9" / V7~^~~i-' ^' -^wATcn 32 3 y* / . .;l_-^2->^ Q) (5* 3 C *^^ ' ' ' • •" l~ "1 m 3 ^-CONC. WALL SECTION B-B f< sy ,H - «•-*-• S- 1 f^- * y-STOPLOGS S?• o <~ / ' i. i iii~r < - / ,jjj i^ .'. ; I< ?»C / / ^^<' • •. ^^':'-' ." L»HE / W 2: CHANNEL J v_rn«rK a 3 . BOTTOM -^ ^-COKCfiETE £/) -' hAYDL-*k HARDING & BUCHANAN. inC us ARMT ENGJ^CER Div new ESGL^ 0 SECTION A-A r-»> NATIONAL PROGRAM OF INSPECTION OF NON-FED DAf- o' 3 LOST LAKE DAM W PLAN a ELEVATION VIEWS a SECTIONS GROTON MA^iCM.jie r 7 •-. I ,o- -.- .:. i PLAN DEVELOPED FROU ON-3ITE INSPECTION I level of drawdown could be achieved include installation of a I bottom pond drain on the existing dam structure or construction of siphoning apparatus. I Installation of a Pond Drain One potential way to dewater Lost Lake / Knopp's Pond is I through installation and use of an underdrain. This would be a permanent feature constructed in the existing dam allowing the lake level to be dropped for winter drawdown, removal of trash I from beach areas and routine maintenance of docks and shore facilities. The principal advantages of such a system are ease of operation, flexibility of scheduling and low maintenance I costs . The main element of this restoration would be the placement of a pipe of sufficient diameter into the dam at an elevation and I grade sufficient to provide drawdown capability to at least five feet. While there are many potential ways to approach this problem, one preliminary engineering approach is shown in Figure I 27. A profile diagram is given in Figure 28. Note that these are schematic diagrams only, and the indicated locations and elevations are estimates which will require field verification. , Properties lines have not be included and will need to be al.so>^ I checked. As indicated in the drawings, approximately 50 linear feet of I 18" ductile iron pipe is placed at a 1.5% grade through the eastern wingwall, approximately 10 ft away from the central spillway. This avoids excessive drilling and minimize disturbance to the present spillway structure. The inlet is I located at a low point in the .pond bottom (minimum elevation of 206 +; ft) . The pipe is routed through a maintenance man-hole with an exit invert elevation of 206 +_ ft and is returned to the I stream* channel at elevation 205 +_ ft. The outlet pipe is secured by a headwall and a rip-rap splash pad used to reduce downstream erosion. A pond drain shut-off valve would be installed and I operated from the top of the wingwall. The location of this shutoff value is identified in a top view of the project (Figure 27) . In order to install this structure, a temporary siphon will be needed to draw down the pond for the construction work on the I upstream side of the dam. Alternatively a coffer dam can be constructed, but this— 3raAaly-e-fee much more coatly i. — ff^J **. -*/*-*-^ I The temporary siphon would consist of 2 or 3 'poly vinyl chloride (PVC) pipes of one foot diameter. Pipe material should be inexpensive due to the temporary nature of this set-up. This system will need pump assistance to start the siphon with a valve I at the top of system. There may also be a need for pumping if I the water level is too low that the siphon cannot be maintained. I I 135 Figure 27. Proposed Pond Underdrain - Top View. .£. Ol/l = * 2-05.0 FJP-EAP 136 •77 (5' C "^ (D ro oo •o -^ o o O ZJ Q. C a3 I The siphoning/and pumping must be continuous during installationJto keep the work area dry. This might involve some channeling of bottom material to route water away from the work I area to siphon pipe or pump intake. An approximate sequence of construction activities is shown in Table 21. Field verification of engineering data and I topographic information is the initial step. Engineering design and finalization of specifications will following, along with filing and approval of all appropriate environmental permits. I The construction phase begins with the drawdown of the lake system. This is followed by the drilling of the wingwall and installation of the drain pipe and valve. Excavation and I treatment of the downslope area would proceed next. The final phase is restoration of the area and removal of the temporary siphon/pump. <—-^Th e tasks and expenses associated with the installation of a pond^jirainare indicated in Table 22.JfNote that there is~a~tlTre'e~ - yea'r i"n f 1 atTorT"f cL'ctoT~b'a*3 e"d~o"rTThe likely delays involved in getting/Phase II /funds under/ the Clean Lakes Program under the fiscal striat.ion ythrs not funcl able u g Clean Lalces Program Installation of a Permanent Pond Siphon ' 6~ An alternative method of drawinc^dbwn Lost Lake / Knopp' s Pond is to install a permanent sipnoning apparatus. This has the advantages of minor structural/alteration to the existing dam, lower construction costs and/less extensive permitting required. The difference between the v€emporary siphon proposed in the pond drain installation is that^fcfeis would be made of more durable materials and would be left\as a permanent feature associated with the outlet structure. Some disadvantages of this system is the greater man-power needs ito operate and monitor its performance, its susceptibility to the elements and appearance A schematic design of a potential permanent siphon arrangement is shown in Figures 29 and 30. The permanent siphon would consist of either steel or ductile iron. Ductile iron is cheaper and less susceptible to damage due to acid waters/ but is quite heavy and would require more effort to install. The steel is more expensive, but lighter and easier to install. The pipe diameter is projected to be one foot in diameter. An approximate sequence of construction is given in Table 23. As with the temporary siphon, this system will require in-line pump installation to assist with the initiation and continuance of the siphon. There may also be a need for pumping if the water level is too low that the siphon cannot be maintained. The siphoning 138 I I I TABLE 21 I Sequence of Construction Activities Associated with the I Installation of a Bottom Drain at Lost Lake / Khopp' s Pond Dam Field Study and Survey - Confirm all dimensions and measurements of structural elements and existing topography above and below the dam. I - Assess condition of dam for structural integrity of proposed alterations. - Determine exact location and depths of deep point within lake. I - Confirm locations of properties lines, easements, etc. - Review hydrological information to determine best period for construction. Select timeframe which balances least disturbance I to the environment ifofeEgstf, recreational activities .and in-lake flows. - Gather additional information required for filing appropriate I environmental permits. Engineering Design - Develop engineering plans, detailed specifications for I construction and pipe installation activities, and bid documents. - File and secure approval for necessary environmental permits (for list, see permits table). I - Attend necessary coordination meetings and public hearings. - Assist in the construction bidding process and evaluate bids with recommendation for award. - Provide periodic construction observation services, review shop I drawings, and conduct water quality monitoring. - Prepare final report. I Temporary Siphon for Drawdown - Clear area as needed for installation of siphon, establish erosion controls for entire site - Install erosion controls for downstream outlet. I - Install siphon and pumps. - Initiate siphoning to drawdown and maintain lake level; supplement I with pumps as necessary, In-lake and Dam Construction - - Prepare access to wingwall in pond for concrete coring equipment. I - Drill hole in wingwall for drain pipe. - Install pipe in channel and seal wingwall. - Install cutoff diaphragms to eliminate leakage alongside pipe. - Install shut-off valve fn pipe and wingwall. I - Backfill trench through dam. - Riprap area near inlet structure on upstream side. I - Close valve and allow pond to fill. I 139 I I TABLE 21 Sequence of Construction Activities (continued) Downstream Construction I - Prepare site by clearing, establish erosion controls. - Trench the downslope area. • - Install lower reach of pipe, headwall, manhole and pipe from | headwall. - Backfill trench, riprap areas near outlet, as shown on plans. • Restoration - Grade areas as shown on construction documents. - Remove sediments in riprap outlet area. I - Loam and seed disturbed areas • - Test pond drain for performance and water-tightness. - Disassemble and remove the temporary siphon/pump structure. i i i i i i i i i i i 140 I I I TABLE 22 I COSTS ASSOCIATED WITH INSTALLATION OF PCND DRAIN Under>Clean Item or Task Estimated Cost ($) Lakes Program I Engineering and Design 15000 Field Inspection and Survey 5000 Temporary Erosion Controls 1500 I Installation of Temporary Drawdown Clearing of construction areas 1500 Piping (120 LF of 1 ft diameter I PVC piping, @ $10/LF) 1200 Elbow joints (4) @ $50/joint 200 Control Valves (2) @ $100/valve 200 Pumps with generators 6000 I Clamps to hold piping 300 Labor costs (assumes 6 day, 3-man crew to install) @ $1200/day ^200 I Sub-total 16600 Inlet Construction 4000 Dam Construction I Clearing to access drilling rig 1000 Drilling through wingwall 3000 Sealant and cutoff 2000 Pipe materials (80 LF of 18" I iron pipe, @ $80/LF 6400 Shut-off valve " 5000 Labor costs (assumes 10 day, 3-man I crew to install) @ $1200/day 12000 Sub-total 29400 Downstream Activities Excavation (50 CY @ $50 /CY 2500 I Box trench, Manhole, Headwall 3000 Rip-rap for outlet area 1500 Labor costs (assumes 5 day, 3-man I crew to install) @ $1200/day 6000 Sub-total 1300. Restoration of Areas 2500 I Environmental Permits 5000 Post-construction Monitoring (3-yr) 6600 75_ Sub-total 98600 Ten percent contigency fund 9900 I Inflation factor (3 yrs @ 7%/yr) 22800 I PRXJECT TOTAL $131,300 I I I4f v[Z Figure 29. Proposed Permanent Siphon - Top View. ESTIMATED BOTTOM • ESf. £U* 206.0* COt*.. VACUUM PUMP VA OVUM OM WALL 142 (Q C -t Air- COCH O T3 O 0> a(D (2-i itV PoMUfe IFOM 3 0) aDt D ffir- PAP AND TD neer •a o i T3 O—i (D* UFTAH& Of I I TABLE 23 I Sequence of Construction Activities Associated with the • Installation of Permanent Siphon at Lost Lake / Kncpp's Pond Dam • Field Study and Survey i - Confirm all dimensions and measurements of structural elements and existing topography above and below the dam. • - Assess condition of dam for structural integrity of proposed | alterations. - Determine exact location and depths of deep point within lake. - Confirm locations of properties lines, easements, etc. I - Review hydrological information to determine best period for • construction. Select timeframe which balances least disturbance to the environment Jdib^rest, recreational activities.and in-lake "~^~ • flows. ~ (/&* J | - Gather additional information required for filing appropriate environmental permits. • Engineering Design - Develop engineering plans, detailed specifications for construction and siphon installation activities, and bid • documents. • - File and secure approval for necessary environmental permits (for list, see permits table) . • - Attend necessary coordination meetings and public hearings. | - Assist in the construction bidding process and evaluate bids with recommendation for award. _ - Provide periodic construction observation services, review shop • drawings, and conduct water quality monitoring. • - Prepare final report. Siphon Installation | ..- Clear area as needed for installation of siphon, establish erosion controls for site. « - Install concrete block. • - Assemble siphon pipes, mounting on structure while assembling. ™ - Install additional equipment such as pumps, aircock, gauge, etc. Excavation I - Prepare upstream site for inlet installation. - Install riprap plunge pool and channel for downstream outlet. • Restoration - Grade areas as shown on construction documents. _ - Remove sediments in riprap outlet area. I - Loam and seed disturbed areas i^ 44 i I and pumping must be continuous during the pipe installation to I keep the work area dry. This might involve some channeling of bottom material to route water away from the work area topsiphon • pipe or pump intakeTH r~ 7* | The period of use of the siphon may well be restricted to fall and early winter, as the possibility of freezing may hinder its usage later during certain months. Typically, the deeper i water that is drawn off will be at temperatures above freezing, but very cold air temperatures could freeze this water in the emergent pipes under low flows. To prevent damage to the pipes i and pumping apparatus, siphoning should not be postponed too late in the autumn, n i ,The costs associated with installing a permanent siphon are shown__in Table_24^^/As^gi.th-t-he—pend—dreTin,,. theSLikelydeESpB" cau"seci~by a/present lack of' funding in/the CleanJLakes Program ( (and resulting ba/cklog of/projects) Ls considered through /an i Vinflation/factorA " " i Installation of a Temporary Siphon A third alternative to the problem of lowering the water level elevation in Lost Lake and Knopp's Pond is the simplest and i least expensive. This alternative is the installation of a temporary siphon at Lost Lake dam. A schematic diagram of the temporary siphon is shown in Figure 31. Installation consists of i using the materials and procedures outlined in the pond underdrain construction sequence. The estimated cost would be approximately $12,000. This figure is based on the fact that i pumps would not be necessary to supplement the siphon (as is necessary in the pond underdrain installation to keep the lakeside construction area dry). It is quite possible that the $12,000 figure can be decreased by the use of local construction i firms to obtain materials or services at lower cost. Permit requirements would probably be restricted to a Wetland Notice of i Intent. This option is favored (te-several c<^t&icte^a%3?oins. Of the two permanent features, the pona underdrain is recommended over the permanent siphon for ease of operation, lowered maintenance and i j^nmunity^from climactic effects. Even so, the effect of lowered TaTce~~level needs to be evaluated, particularly with regard to private drinking water wells. The temporary siphon can be used i to assess the scope of this problem, and provide an early definitive answer to the feasibility of a permanent structure. i Secondly, the delay associated with installation of a pond underdrain is likely to be two years,/or greater, based on the i current fiscal status of the Clean L'ake^Phase II funding levels. i i 145 I I TABLE 24 I COSTS ASSOCIATED WITH INSTAIIATICN OF A PEE&BNENT SIPHCN I Under Clean Item or Task Estimated Cost($)_ Lakefe Program I Engineering and Design 8000 Field Inspection and Survey 5000 Temporary Erosion Control 1500 Installation of Siphon I Clearing of construction areas 1000 Piping (140 LF of 12" diameter ductile iron piping, @ $60/LF) 8400 I Installation of pipe @ $10/LF 1400 Elbow joints (6) @ $50/joint 300 Flared ends (4) @ $40/end 200 I Concrete Block for Pipe 500 Control Box 1000 Control Valves (2) @ $300/valve 600 Vacuum Pump 2000 I Clamps to hold piping 500 Labor costs (assumes 8 day, 3-man crew to install) @ $1200/day ' 9600 I Sub-total '25500 Preparation of inlet and outlet Excavation and rip-rap at inlet 3000 I Downstream Rip-rap. . 1000 Sub-total 4000 I Restoration of Areas 1500 Environmental Permits 5000 I Post-construction Monitoring 6600 Sub-total 57100 I Ten percent contigency fund 5700 I Inflation factor (3 yrs @ 7%/yr) 13200 PROJECT TOTAL $76,000 I I 146 I •n (5' c—i O •o O 3 •a o-^ D) • 3- O T3 "i O I The temporary siphon allows an effective way in which some of the benefits of drawdown can be obtained within one year^.^The " ~~-N. I ljh^e^tctl-nt'y"oT~iro'S"t~^a1ce~~/'"Khopp'~s~Po"nci~to-tje—awaTBecl a Phase II )' I grant/s'fibuld^r;^ recogmTzececojg K as this Anticipated Impacts of a Drawdown There are several potential problems associated with I conduefeing—a^drawdown of Lost Lake / Knopp's Pond. These are the V (sustainatn^lity* of the drawdown, the refilling of the pond in the spring, the impact on abutting wells, the impact on the fish, the • impact on the neighboring wetlands, and the effects on downstream | resources. The effects of the/sV" proposed project also neeol5to be —" Jed with respect to restoration of the lake water quality. m The amo6nt£xff water to be parsed over the dam to reach a - I drawdown depth of 5 feet is a substantial amount. Therefore, removal of this water needs tc/be phased over a periodj^time to — • minimize downstream impacts. //-Calculations indicate that a | drawdown period of six weeks would be needed to drain the pond down to an elevation of 207jH ft while still passing normal autumn • inflows (for calculations see Appendix) . The recommended period I of drawdown would be the late October to November, during the period of low groundwater. reverse problem connected with a winter drawdown is the • required assurance that once drained, the lake can be refilled. AS Lost Lake / Knopp's Pond is largely an impoundment, refilling K to a full pool simply becomes a matter of shutting off the | underdrain or breaking the siphons and allowing tributary inputs to accumulate. The flushing time of Lost Lake / Knopp's Pond _ indicates that a refilling period of less than two months can be I expected if all spring inflows are retained. Both the drawdown ™ and the refilling are recommended to be stretched out over a two month period, so that downstream flows are moderated. The timing ] • of the return of full pool size should be such that maximum ' | depths are obtaining)in time for spring stocking of trout. Exploring this problem a little further, the effect of I extended drought on the refilling period was considered. The i i 148 i I I projected minimum flow for the Lost Lake / Knopp' s Pond watershed for a period of 120 days is 1.29 cu. m/min with a two year recurrence period; and 0.63 cu. m/min. for a 10 year recurrence interval. In terms of the time needed to fill the lake with these flows, the two year low flow dictates 164 days, while the I 'ten year figure requires 391 days. Under these hypothetical flow regimes, the lake would take 3 to 13 months to regain its former I water level. However it should be emphasized that these are hypothetical values, and that such low flows are unlikely to be encountered I for such extended periods (i.e., the period to refill takes much longer than the 120 day drought period, and greater flows would be expected) . Further, these very low flows normally occur during the late summer and early fall. The period of refill for I Lost Lake / Knopp' s Pond is in the late winter and early spring, times of high recharge to lakes. Under typical precipitation for the months of March through May, based on 30 years of records I (NOAA, 1986) , an expected refill time of 31 to 36 days is estimated. The calculations and assumptions for these estimates I are given in the Appendix. The third potential problem involves the impact of the drawdown on shallow wells in homes abutting the pond. Results from the questionnaire survey indicate that about 34% of these I wells are less than 20 ft in depth, while 60% are less than 50 ft. If the water level is dropped by 1.5 m, there is the potential for^'iohknown number of households to experience some I loss in well production capacity. It is unlikely that many wells would go dry or that demand would exceed production. Yet, the potential for supply impairment exists and would need to be ^,rt carefully evaluated. Empirically, an experimental drawdown Tto I various depths and determination of the number of wells affected at each foot of drawdown provides the best criteria for evaluating the scope of this problem. Al-tSrnatively, since I October is a period of low groundwater/^tabj/es, winter drawdown could be postponed to late November or eaasly December, which are wetter periods. The problem with defay'^is that more basal flows will have to be passed, so that some exce'ss draining capacity I be needed. The fourth potential problem is a negative impact to the I fishery of Lost Lake / Knopp' s Pond. The decreased area and depth of the remaining standing water increase the possibility of oxygen depletion under the ice. This could lead to a winter I fishkill and reduced numbers in the spring. Currently, the fish community at Lost Lake / Knopp' s Pond is heavily populated by panfish. Improvement of the fishery through the reduction of macrophytes is likely to outweigh the adverse effects of the I drawdown. However, determination of the frequency of a winter I drawdown for lake management should take this into account. I I 149 I The effect of the drawdown on the wetlands is another potential problem. The area most affected by the drawdown would I be the wetlands marking the entry point of Martin's Pond Brook I into the lake. However, most of this wetland should be kept well supplied with water by basal streamflow, although some • dessication of marginal wetlands can be expected. During an I experimental drawdown, the impact on these areas can be ' ascertained and the need for mitigating measures evaluated. _ The impact of drawdown on downstream resources is one of . ' concern to homeowners in the areas to the north of Lost Lake. The immediate downstream resource is a narrow pool formed by a • widening of the outlet flow of Lost Lake. The amount of capacity . I of this area is considerable and it will be able to handle the additional flow amounts proposed without flooding. A large • culvert (4.5 ft diameter) passes the flow under Lost Lake Drive I which is on an embankment. Below the road, the flow enters a channel which enters Whitney Pond and its adjacent wetland areas. The combination of Whitney Pond and its associated wetlands I should provide sufficient storage and temporary detention of • these higher than normal flows. At the outlet of Whitney, the flow of Cow Pond Brook is | passed under Rte. 40 (Lowell Rd.) via an aperture at the base of the highway crossing (see Figure 5) . The size of this opening is _ relatively small (roughly 6 ft wide by 3.5 ft deep), and under I high flows this point is a constriction subject to water backing * up. Continuing further downstream, the flow goes into an extensive wetland (Burnt Swamp) and under a simple bridge over • Cow Pond Brook at Wharf Rd. This area provides additional^-— ^"~ I storage and detention space. Beyond this structure is additional wetland area that has few residences in close proximity to Cow • Pond Brook, and consequently, little concern about increased I stream flows. Cow Pond Brook eventually empties into Massapoag £, Pond, a large waterbody trisected by Groton, Dunstable and fTyngsborough. Interestingly, this pond is slated to undergo a I (water level drawdown in 1989 as a means to control peripheral • ^weeds and aid shoreline maintenance (pers. comm.- Mr. C. v, ... * .-An important consideration/is that the projected j.*™..*. ^drawdown flows from Lost Lake^/are well within the normal range of _ " the annual flow regime. The projected drawdown flow is • approximately 12 cu. m/min., a little less than that expected • during the months of March through May. Note that the opening under Rte. 40 at Cow Pond Brook is capable of passing greater • than 70 cu. m/min before the opening is submerged and water I starts to back up. Further, these drawdown flows will be , scheduled during a period of the year i^t) which groundwater tables ^ • and lake storage should be at a minimum. In a practical sense, I the drawdown consists of passing normal spring flows during the i i 150 I driest part of the year. While some caution needs to be I exercised in any drawdown procedure, there is no reason to anticipate flooding under normal weather conditions. Another important feature for safeguarding downstream I resources is the capability of stopping the siphoning procedure and downstream flows at very short notice. This may be necessary if a large storm or series of storms occur. It is suggested that I staff gauges be installed at the culvert at Lost Lake Drive and the passageway of Cow Pond Brook at Rte. 40. These can be easily monitored during the siphoning period to check whether water I levels are rising faster than anticipated, or to monitor the combined effects of rain and drawdown flows. . A potential procedural matter came to light during the third I public meeting. That is the question whether a fall drawdown violates the current zoning prohibition on increased runoff. It is not likely that such a drawdown would be construed as.there is I nol/ increase in surface runoff connected with this drawdown, just the release of some of this natural runoff. However, this is a question which should be examined by the town's a'ttorney to make sure that the letter and intent of the zoning^ordihrances are I respected. Water quality should be typically good during the drawdown. I There may be some slightly increased suspended sediment as some bottom areas are exposed. Fine sediment particles may be enter Whitney Pond and increases its turbidity. However, this does not I threaten the drinking water supply as this turbidity will be filtered out by the intervening soil layers. One additional consequence of the drawdown would be the I potential for removal of oxygen poor water from the deep hole in upper Lost Lake. While there is nor a^pronounced oxygen deficit occuring in the northern basin during summer, removal of this I water can only be beneficial. Two results of this lowered oxygen is loss of fish habitat for coldwater fish (e.g., trout), and the potential for anoxic remineralization of phosphorus. I Selective removal of bottom water via an underdrain or siphon would provide a means to induce replacement and mixing with the more oxygen-laden upper waters. The impact of this oxygen-poor I water on downstream resources is likely to be mitigated by the aeration and turbulence created by the splash pad and the mixing in the natural riffle areas downstream. Overall, this should I just be regarded as an additional benefit and not an important justification in itself. The anticipated impact of the winter drawdown is a reduction I in the littoral nuisance macrophytes in 55% of the area of Lost I Lake / Knopp's Pond. It is likely that this program will not I I 151 i significantly change the nutrient loadings of the pond, but should decrease the phosphorus budget by approximately 5%. This decrease is associated with reduced macrophyte pumping and, i increased oxidation of exposed sediments. Some increased turbidity downstream may result from streamflow carving through drawdown sediments due to resuspension of fine silts and clays. i However, significant transport of sediment is not likely due to the standing pool in upper Lost Lake that exists near the dam. i Costs, Permits and Summary The projected costs of a drawdown are variable, depend/ng on the method w^^^lo>?Sjar_e^\pa^s%i^'(underdrain or siphons) ,Jj The major costs are^onnected with the installation and materials, as the actual operational costs are rather minor requiring o_nly_a i daily adjustment of the drawdown device .^ypresently, this maintenance would be required within the^-duties of current Grotonwoods employees. However, it is likely that Grotonwood will insist as a condition of any agreement"^ or changes in the i dam the stipulation that the town of Groton would assume ownership and responsibility for the dam. Therefore, the maintenance and operation of the dam^wouliJ need^cp to be included i in future town budgets. Pending some—so'rtx of agreement, the costs of operation and maintenance are not ^directly figured in the construction budgets of the alternative\>ptiops. i 'A third alternative that should be considered is the use of temporary siphoning to test the problems connected with the drawdown of Lost Lake and Knopp's Pond. This utilizes the i procedure of temporary siphoning outlined in the sequence for the installation of the pond drain. This could be used as the first attempt to determine the effects on lakeside wells and overall i operational ease. It is the least expensive option <^th~e7test the impact of a drawdown. Development of this plan is particularly appealing i^T^e^Clean Lakes Program funding—i a de 1 ayed—oa=-rr-tri.jed —for th-Q i Several permits are required for these projects,^and this is reflected in the associated costs. There is fefe^ge'heroisrevie w i by state programs (Natural Heritage Program, Historical Commission, aaffi fMEP-A7 unit^-of information generated in this study, .a^-j^eJJL-r)s. r.natagfe-^wr^itthe Division of Fisheries and Wildlife'. For the7 alterations to the dam structure the following i permits are likely to be required: a Notice of Intent under the Massachusetts Wet/lands Protection Act with an Order of Conditions^ a Division of Waterways (Chap. 91)application«and a i DWPC Water Qualify Certificate. Review of 'this project tfy the Army Corps of Engineers will\ need-to determine Section 404 applicability (although thisXis notyikely to be required). The i addresses of these agencies are giver^ in Table 32 i i 52 i I I I MACROPHYTE BOTTOM BARRIERS I Elements of Program One relatively inexpensive technique to allow some measure of I relief from the nuisance aquatic plants would be the deployment of bottom barriers. A bottom barrier consists of a layer of synthetic material that is laid directly over the bottom and weeds. It effectively compresses and shades aquatic macrophytes I so as to suppress their growth. In doing so, it opens up areas of relatively open water for recreational purposes. I There are several commercial products (e.g., Aquascreen, Dartek, Texel) that form a sheet to cover the developing macrophytes and stunt or kill them by shading. These products I were recently reviewed {Cooke et al., 1986). Other slightly less expensive but possible effective barriers may also be locally available. I The screen is dense enough to reduce light to low levels, yet permeable to gases underneath (which prevents gas buildup and "ballooning" of the cover to the surface). Usually, the screen I is placed over the macrophyte beds in early spring and taken up again in mid-summer before the major swimming season. The timing of this application deprives the macrophytes of light during their most crucial growth period. The plants may continue to I grow after the screen is taken, up but usually they are stunted and fewer in number. In some test situations this retardation of growth has been effective in controlling plant levels for a I second season or more after the initial application. The screen is positioned in shallow water by hand, but a I diver may be necessary for application in deeper waters. It must be weighted (e.g., cinder blocks) or staked down (Figure 32). A major advantage of these screens is that they are reusable. They can be retrieved from the water, washed, dried and stored for use I in succeeding years. With proper care, five seasons or more of use can be expected. I Use of a screening technique is not without its disadvantages. Decomposition of plant material underneath may decrease available oxygen and add nutrients to the lake. Habitat for reproduction by certain fish species is reduced. If not I properly weighted or staked, the screen may come loose and shift from the desired area. For Lost Lake / Knopp's Pond the effects of decomposition would be negligible and ample fish nesting areas I are found in the areas not subject to screening. I I 53 APPLICATION OF BENTHIC BARRIER 4P7IOUAL FLQRT BOTTOM CQVER I In considering using this technique for macrophyte control, I there is a tradeoff between labor cost, effectiveness of plant suppression, and screen longevity. .For best conservation of the material, the screen should be applied in spring, e.g., late April and taken up in mid-June. A second scheme would be to I place the screen in April and keep it in until fall (Labor Day) . This would subject the screen to damage by swimmers or boats and is not likely to last as long. The last option is simply to I place the barrier in and leave it there permanently. This means the screen will be exposed to recreational damage, winter conditions, and eventual sedimentation providing new substrate I for macrophytes. This will likely lessen the effective lifetime of the screen. Better maintenance access to the screen would be possible during a winter drawdown. Realistically^however, retrieval of the screens from the treated areas (Jrijz ke a I decision of individual homeowners. Therefore some screens can be expected to be retrieved yearly and some will be/left in I permanently. Anticipated Impact of Improvements on Lost Lake / Knopp/ s Pond I This option will have a beneficial impact on the recreational enhancement of Lost Lake / Knopp's Pond. Two specific improvements will be in swimming and fishing accessibility. I Areas treated with a bottom barrier will be relatively free of nuisance macrophytes. There is the possibility of macrophytes floating (e.g. Utricularia) into swimming areas, but this is not I likely to be a great problem. Fishing will be improved by the attraction of fish to the edge habitats created, as well as improved ease of casting. I This option will not significantly alter the phosphorus budget or trophic status of Lost Lake / Knopp's Pond. Some reduction of sediment phosphorus release mediated by macrophytes I may be realized but is unlikely to register as a detectable change in water quality. By opening portions of bottom to increased circulation, movement of water in some stagnant areas I is re-neQuragcd. I Costs, Permits and Summary Typical costs for a bottom barrier (e.g. Aquascreen) are approximately $15,700 per acre (1989 prices) including the rods I to pin the barrier to the bottom. Installation costs are not included. The screens come in 100 foot rolls of 14 foot width and cost about $500/roll. I For an individual lakeside property owner, the amount of screening necessary to suppress growth in weed-choked areas is estimated at 2 rolls (2,800 sq. ft). To cover this area at I current prices would cost approximately $1,000. If a four-to- I I 155 I five year life expectancy is used, the price per year is about $200-250, although installation costs would have be figured in. • It is possible that cheaper prices could be obtained through a I housing supply wholesaler. Installation costs could be saved if lake abutters cooperated in putting down the screen themselves. • Considerable savings are also possible if adjacent owners shared | the cost of materials and installation by creating a large common open space along their property boundary lines. _ The most efficient way for bottom barrier material to become ™ available to the shoreline residents of Lost Lake / Knopp' s Pond is for the Town of Groton to act as a purchasing agent for the • material. It is suggested that the town make a large purchase | (e.g., $20,000 worth) of bottom barrier material and sell to Jr f* individual residents at cost. The advantage of this approach isj^ ^ m a substantial savings to the individual homeowners if the ^s fp** • material is purchased in bulk. The town of Groton _ca_n act^as a clearinghouse for information on application. {This amount* of material provides sufficient basis to test the effe'clTiveness and • popularity of this program. If judged satisfactory such a • program can be repeated in response to demand. One particularly useful field demonstration wis^the use of | Aquascreen at Sargisson Beach (Figure 33) . The shallows of the beach are covered by imported sand, which gives way to -areas of _ nuisance macrophytes. The areas of macrophyte infestation, • estimated at about 15,000 sq. ft could be treated with a bottom * barrier. This has two advantages, it allows ^%y/ inter ested_ _ ^^ parties to "test" the product at their leisure, ^nd THis portion^ • rgf—fh)a~~pu'rcha-se—i-s—;£andabie-^mggr~tiie~ngarggnt~Clean Lakes ! regulations"^/—Th-e^cbst~^"f-t-hl"s~"treatment is e~s~fi"mal:eS""~at~ ~$1>, 000 . L_J_\——-"The permi^t requirements for bottom barriers are not •• extensive. Under the Wetlands Protection Act an Abbreviated or Full Notice of Intent will be required from the Groton Conservation Commission. Typically, the Conservation Commission • issues Orders of Conditions regarding the installation of this " • material. The bottom barriers should be viewed as a short-term lake i management option, to provide some measure of localized macrophyte control until benefits of/nutrient reduction are achieved. Use of the-,macr-Ophyte^bottom bar.r-i-er.s would^airre-liorate' I fc''' unt''f these water— qu"alit " y issues are ^— -^ . I• I I I I Figure 33. Proposed Application of Benthic Barriers at Sargisson Beach. Benthic barriers at Pubiic Be 157 158 I I I WATERSHED MANAGEMENT I IMPROVING SURFACE WATER QUALITY Elements of Program I The concept of the drainage watershed is a critical one, both from the viewpoint of present lake condition and future planning. Presently over 85% of the phosphorus comes into the lake system by either surface tributaries or groundwater. Reduction of I loadings in either category will reduce the eutrophication of Lost Lake / Knopp's. Often the adoption of practices that decrease pollutant stress on one, will also have a beneficial I effect on the other. Watershed management of both surface and groundwater quality are addressed in two separate sections in this report, but the means to promote both is more easily I achieved by packaging this information in a single source. In both sections, attentions is focused on both "macro" (town zoning) and "micro" (individual practices) decision-making. I Several lake management options for Lost Lake / Knopp's Pond involve some sort of change in the watershed, often concerning modification of existing land uses or practices. These include I land use controls, agricultural and residential best management practices, and changes in watershed resident practices. These are by no means independent entities, as all interact with each I other, but each is addressed below on an individual basis. I Land Use Controls Protection of lake water quality through zoning ordinances involves possible changes of local regulations intended to provide for more comprehensive protection of Lost Lake / Knopp's I Pond. A strategic approach attempts to protect water quality through careful planning and decision-making about present and future land use in the watershed. Groton could potentially I designate sensitive areas for either re-zoning, protection from development, or accompanying strict orders of conditions for development. The tools in this case are zoning ordinances, I establishment of environmental setbacks and development options. Examples of these options are given in Table 25. The personnel connected with making these decisions are the local Planning Boards, Zoning Board of Appeals, Board of Selectmen, Conservation I Commission, the town planner, parks and recreation department and citizens groups (e.g., nature conservancy groups). Influencing local technical and strategic decisions are regional issues which I transcend property boundaries; -Aquifer and lake watershed management and protection are two examples of these issues. Regional planning agencies (e.g. Montachusett Regional Planning Commission) , or lake districts, are appropriate groups to provide I coordination at this scale. I 159 Table 25. Zoning and Developmental Options (USEPA, 1988). DEFINITION I TOPIC Zoning The regulation of building types, densities, and uses permitted in dis- tricts established by law. I Special Permits/ Administrative permits for uses that are generally compatible with a Special Excep- particular use zone, but that are permitted only if certain specified stan- tions/Conditional dards and conditions are met. Use Permits I Variances Administrative permits for uses that are generally compatible with a particular use zone, but that are permitted only if certain specified standards and condition are met. I Floating Zones Use zones established in the text of a zoning ordinance, but not mapped until a developer proposes and the legislative body adopts such a zone for a particular site. I Conditional An arrangement whereby a jurisdiction extracts promises to limit the Zoning future use of land, dedicate property, or meet any other conditions. The arrangement is either stated in general terms in the zoning ordinance or I imposed on a case-by-case basis by the legislative or administrative body, prior to considering a request for a rezoning. Contract Zoning An arrangement whereby a jurisdiction agrees to rezone specified land I parcels subject to the landowner's execution of restrictive covenants or other restrictions to dedicate property or meet other conditions stated in the zoning ordinance or imposed by the legislative or admini- strative body. I Cyclical Rezoning The pericdic, concurrent ccnsic'sration of all pending rezoning applica- tions, generally as part oi an ongoing rezoning program, focusing upon one district at a time. I Comprehensive Provisions that require all zoning actions, and all other government Plan' actions authorizing development, to be consistent with an indepen- Consistency dently adopted comprehensive plan. I Requirement Zoning Ratification of legislatively approved land use changes by popular vote, Referendum before such changes become law. I Prohibitory Zoning The exclusion of all multifamily, mobile, modular, industrialized, prefab- ricated, or other "undesirable" housing types from an entire jurisdiction, or from most of the jurisdiction. I Agricultural The establishment of "permanent" zones with large (that is multiacre) Zoning/Large Lot minimum lot sizes and/or a prohibition against all nonagricultural deveJ- Zoning/Open opment (with the exception of single-family residences and, possibly Space Zoning selected other uses). I Phased Zoning/ The division of an area into (1) temporary holding zones closed to most Holding Zones/ nonagricultural uses and/or with large minimum lot sizes, and (2) ser- Short-Term Ser- vice areas provided with urban services and open for development in I vice Area the near term (for example 5 years). Performance An arrangement whereby all or selected uses are permitted in a dis- Zoning/Perform- trict if they are in compliance with stated performance standards, that I ance Standards is, if they meet stated community and environmental criteria on pollu- tion, hazards, public service demands, etc. Flexible Zoning/ Freedom from minimum lot size, width, and yardage regulations, I Cluster Zoning/ enabling a developer to distribute dwelling units over individual lots in Density Zoning any manner the developer desires, provided (usually) that the overall density of the entire subdivision remains constant I I I60 I I Table 25. Zoning and Developmental Options - continued (USEPA, 1988). I TOPIC DEFINITION Planned Unit A conditional useorfloating zone regulated through specific design Development standards and performance criteria, rather than through the traditional I (PUD) lot-by-lot approach of conventional subdivision and zoning controls. Subdivision Procedures for regulating the division of one parcel of land into two or Regulations more parcels—usually including a site plan review, enactions, and the I application of aesthetic, bulk, and public facility design standards. Minimum Lot Size The prohibition of development on lots below a minimum size, Minimum Lot Size A limitation on the maximum number of dwelling units permitted on a lot, I Per Dwelling Lot based on the land area of that tot (usually applied to muto'family housing). Minimum Lot Size A limitation on the maximum number of rooms (or bedrooms) permitted on Per Room a lot, based on the land area of that lot (usually applied to multifamily I housing). Setback, Front- The prohibition of development on lots without minimum front, rear, or side age, and Yard yards or below a minimum width. I Regulations Minimum Floor The prohibition of development below a minimum building size. I Area Height Restriction The prohibition of development above a maximum height. Roor Area Ratio The maximum square footage of total floor area permitted for each square I (FAR) foot of land area. Land Use Intensity Reguiations that limit the maximum amount of permitted floor space and I Rating require a minimum amount of open space (excluding parking areas) and recreation space, and a minimum number of parking spaces (total and spaces reserved for residents only). I Adequate Public The withholding of development permission whenever adequate public Facilities facilities and services, and defined by ordinance, are lacking, unless the Ordinance facilities and services are supplied by the developer. I Permit Allocation The periodic allocation of a restricted (maximum) number of building per- • System " mils or other development permits first to individual districts within a juris- diction and then to particular development proposals. I Facility Allocation The periodic allocation of existing capacity in public facilities, especially in System sewer and water lines and arterial roads, to areas where development is desired while avoiding areas where development is not desired. I Development A temporary restriction of development through the denial of building Moratorium/ permits, rezonings, water and sewer connections, or other develop- Interim Develop- ment permits until planning is completed and permanent controls and ment Controls incentives are adopted, or until the capacity of critically overburdened I public facilities is expanded. Special Protec- Areas of local, regional, or State-wide importance—critical environ- tion Districts/ mental sreas (for example, wetlands, shorelands with steep slopes); I Critical Areas/ areas with high potential for natural disaster (for example, floodplains Environmentally and earthquake zones); and areas of social importance (for example, Sensitive Areas historical, archaeological, and institutional districts)—protected by a special development review and approval process, sometimes involv- I ing State-approved regulations. I I I The existing zoning classifications for the Lost Lake / Knopp's Pond watershed in Groton are shown in Figure 34. In the I upper Martin's Pond Brook and the unnamed tributary watersheds I the major types of zoning are R-A, residential-agricultural and C, conservancy district. To the west of Lost Lake there is a • considerable tract of institutional properties associated with J Grotonwood, and to a much lesser degree, the Stone Environmental School, However, this is "not an officially designated zoning _ type. Along Lost Lake Drive, several lots are zoned Bl, business • district. In this area there is also some official open space. • At the Four Corners area, there is significant amounts of B-l business district • Recognition and management of the watershed and sub-drainage basins is necessary to improve or protect tributary water • quality. Each sub-drainage basin should be evaluated to see I whether potential threats to the well being of Lost Lake / Knopp's Pond water quality exist. Existing threats should be eliminated or mitigated. The rationale behind any resulting I restrictions is that where water quality is concerned , it is • much more cost effective to extend regulatory protection now than pay for a costly clean-up program (or repetition of such) later. • This has been recognized in Groton by the designation of water | resource districts, in conjunction with groundwater protection. These districts are useful entities to insure surface water . quality as well. I The acquisition of open space land and "greenbelts" along major tributary streams is an effective way to protect lake water • quality. In addition to providing recreational space, these I areas reduce nutrient and sediment loadings to Lost Lake / Knopp's Pond, and are consistent with other town goals (e.g., • aquifer protection) . Fortunately in the watershed, most of the I wetlands and much of - the stream watercourses are already zoned as conservancy districts (Figure 35). The Conservation Commission has the expertise and means to select and preserve additional • environmentally sensitive areas. Generally grants for acquiring • conservation or open space land are available through the Federal Land and Water Conservation Fund (EOEA, Federal Pass Through) or • the Massachusetts Self-Help Program (M.G.L. Chap. 132) . Given | the high amount of control over existing wetlands, no immediate land acquisitions are recommended. _ For the Martin's Pond Brook watershed, another somewhat • useful program is the Division of Fisheries and Wildlife 's Riverways Program, better known as "Adopt-a-Stream". This • program aids in the protection of natural stream corridors • through assistance in public education and technical expertise. Given the large watershed area of Martin's Pond Brook, this m program may act as the nucleus to a citizen's coalition group. I Martin's Pond Brook is particularly important due to its vicinity i i I6Z I I Figure 34. Town Zoning in Lost Lake / Knopp's Pond Watershed. I I I I I , SEE DETAIL iy- 9-V° ~>Sllfil8v I ii / *v *_£ j^/f4-a^'T I //?.•?/ /trfffi &£''•'*'£? I ^•^ .-<&y /$' ?t&\- 'e^Wf • f-X^&J^ "** . "^V> I 3J rfw /ff!Ty"*''iT^"i iVT^T . H ? .- our^AJj / ^ c, jft^il^^. •---r^^rWO0^6«x5^XX9^ST^i^^^ff 1-^*-i) _^ J C^^^>^X^-M240:^ —~*-:--L.--.\ v s~ * ••)• I l{ » ".; 1 ( ^ i. f^-^7 I ^q^lS^A l h^&^.•'•'K. \ (>"fy/ if"I r. f i^\- ^\ I 163 I I I I I I I I I I I I I I CT I- - - I Groton Conservation Trust I cc Illllllll Groton Conservation Commission GR Town of Groton Figure 35. Open Space and Conservation Lands ir I M ^ bsX\l Commonwealth of Massachusetts the Lost Lake / Knopp's Pond Watershed NE f*y%*3 New England Forestry Foundation : I PR txVi-" 3 Private Conservation Restriction t" - loon' PREPAID BY EDWARD A MASON FOR THE GROTON CONSERVATION TRUST— Revised January 1987 • I — 1 o.)U i ^1 2.8" == 1 mile 164 i I to the Whitney and Baddacook Pond well fields along it stream I corridor. Information about this program is included in the Appendix. I Acquisition of land for agricultural preservation is another potentially important land use decision in the Lost Lake / Knopp's watershed. Land can be retained for agricultural I purposes through several programs including the Agricultural Preservation Restrictions Act (M.G.L. Chap. 780), the Farmland Tax Assessment Act (M.G.L. Chap. 61A) , and the Massachusetts Farm and Land Conservation Lands Trust. At the local level, creation I of agricultural preservation districts or enablement of transfer of development rights are ways that agriculture and its life style can be preserved within a town. These decisions are related I to the town's perception of its image and future cultural inheritance. With regard to agricultural preservation and water quality I in Lost Lake / Knopp's Pond, no recommendation can be easily made. In the long term, agricultural land use usually has a greater potential for export of nutrients and sediment that I residential land use. This does not mean that a well-managed farm will inevitably export more nutrients and sediment than a large residential sub-division. The reverse may be true, I particularly during construction of the latter. However, as the disturbed land is revegetated and stabilized, loadings from residential areas decline, while agriculture provides an annual disturbance of the land and application of fertilizers, I herbicides, and pesticides. If best management practices are judiciously applied, thought, both types of land use can be made I compatible with good water quality. Adoption of Best Management Practices I Addressing these non-point sources is a complex issue, containing both technical and strategic solutions. The technical approach combines elements of nutrient and sediment control, I under what is broadly termed "Best Management Practices" or BMP's. A best management practice (BMP) is defined as "a practice or combination of practices that has been determined by I the Massachusetts DEQE to be the most effective and practicable means of preventing or reducing the amount of pollution generated by non-point sources to a level compatible with water quality goals" (Massachusetts River Basin Planning Program, 1984). A I partial listing of these BMP's is given in Table 26. These BMP's are an effective way to mitigate or eliminate nutrient loadings or sediment under existing conditions. Information and I supervision for implementing these BMP's typically comes from the local Conservation Commission, town engineer or sanitarian, I regional SCS or USDA staff. I I 165 Table 26- Best Management Practises Categories. I I BEST MANAGEMENT PRACTICE CATEGORIES 1. Animal Waste Management 9. Grassed Waterways I a. Waste SCorage Pond 10. Diversions & Terraces b. Waste Storage Structure I c. Waste Treatment Lagoon 11. Rehabilitate System d. Strearabank Fencing a. Septic Systems b. Saver Lines I 2. Pasture Management c. Upgrade Runoff Controls a. Prevent Overgrazing ••b. Pasture Planting 12. Extended Detention Ponds I c. Windbreak 13. Wet Pond/Harsh 3. Conservation Tillage I 14. Infiltration Trench/Basin a.. No-Till b. Ridge-Till a. Dry Wells c.'Strip-Till I d. Mulch-Till 15. Porous Pavement e. Reduced-Tiil 19. Oil/Grit Separators. I 4. Cover Cropping 20. Stormwater In-Line Storage a. Off Season Planting I b. Rotate crops with Sod 21. Grade Stabilization 5. Contour Farming a. Streambank. Stabilization I a. Contour Strip Cropping System 22. Dredging 6. Nutrient Management 23. Tight Tank Bylaw I a. Application Rate Control a. Septage Receiving Facilities b. Eliminate Fall Applications -'- c. Soil and-'Manure Testing 24. Physical/Chemical Treatment I -d. Animal Waste Storage a. Package Treatment Plants 7. Pest Management b. Capping I c. Incineration a. Use Lass Persistent/Volatile d. Filtration Pesticides b. Application Timing/Method Control 25. Education I c. Use of Resistant Crop Varieties a. Septic System 8. Filter Strips b. Lawn Care I c. Boat Septage Handling a. Grass d. Waterfowl b. Forested I I 166 I I The most important source of nutrients to Lost Lake / Knopp's I Pond is from the Martin's Pond Brook sub-drainage basin, where they are derived from a variety of land uses. Reduction of these largely non-point sources has the greatest potential for I improving the water quality and trophic status of Lost Lake / Knopp's Pond. The sub-drainage basins of the unnamed tributary and Redwater also contribute to the pond, but neither has the size or flow of the Martin's Pond Brook basin. Considering the I relative size of the nutrient inputs and the location of the tributary inlets, the priority for clean-up should be the Martin's Pond Brook watershed followed by the unnamed tributary I watershed. The watershed of Redwater is so small as to be negligible. I The tributary water quality survey conducted in the diagnostic study (Figure 10, Table 4) suggested that agricultural practices in the northwest portion of the Martin's Pond Brook watershed export were responsible for relatively greater nutrient I totals. This area is the most appropriate one in which to concentrate efforts of promotion of best management practices. However, their adoption is also recommended for the entire Lost I Lake / Knopp's Pond watershed. The application of agricultural best management practices (BMP's) is highly desirable but can provide an economic burden to I the farmer that is not easily borne and may, in fact, lead to a less desirable state of affairs for the watershed (overdevelopment). Currently, there a diversity of programs, but I limited money available for implementation, and the economic status of many farms preclude intensive individual action. Further, the economic pressure and monetary incentives to sell I farmland for residential developments that exist in Groton do not encourage adoption of additional costs on the area's remaining farmers. I At this time, a less stringent approach is suggested; that of gradual education and adoption of BMP's through propagation of information on alternative farming methods which are both I economically beneficial to the small farmer and represent good stewardship of the land. These practices are also beneficial in reducing the effects of cultural eutrophication and sedimentation in Lost Lake / Knopp's Pond. Information on BMP'S and watershed I erosion protection is available from the United States Soil Conservation Service (SCS) , whose nearest field office is in Acton, MA., the Cooperative Extension Service, University of I Massachusetts, Amherst, and the New England Small' Farms Institute, Belchertown. A description of the more relevant BMP's I is listed in the Appendix (USEPA, 1988) . Another fertile area for adoption of BMP's is with regard to I residential development, both in the Martin's Pond Brook I I 167 I watershed and Knopp's Pond watershed. Treatment of septage and _ storm drainage are two important factors determining water I quality. Sanitary sewers are preferable to on-site wastewater • management ("septic") systems, but are not currently available throughout the watershed. If septic systems are used, their • proper care and maintenance is important for the minimization of I pollutant loading to the groundwater (see section on On-Site Wastewater Management). • The careful management of stormwater runoff is getting increasing attention with the growing awareness of the need to manage not only for flood protection, but for water quality, as I well (Schueler, 1987). There are many alternatives to simply • routing runoff from impervious surfaces to the nearest watercourse. These include use of: filter strips, grassed • swales, detention ponds (both dry and wet), infiltration trenches | and leaching basins. Selection of the most appropriate BMP is always dependent on site-specific characteristics such as the _ amount of storm flow, distance from wetland resources, depth and • nature of the soils, proximity to aquifer recharge zones, and * maintenance considerations. A matrix illustrating some of the factors used in the screening the appropriateness of BMP's is I shown in Figure 36. I Incorporation of these runoff BMP's is already being • practiced in some regions of Groton. For example, storm runoff | is dictated to be "recharged on site to the maximum extent practicable" in both the Primary and Secondary Water Resource Districts (Section 5.9.5; Zoning By-Laws, Town of Groton). I Recharge is a useful option for other parts of Groton, although • soil permeability is the critical factor in determining applicability to a site. Future development in the watershed, • such as in the Four Corners and. Brown Loaf areas should | incorporate the BMP's to the "maximum extent practicable". Residents Environmental Practices i This refers to adjacent residents' practices that are I potentially detrimental to water quality in Lost Lake / Knopp's I Pond. These practices include: unwise application of fertilizer, pesticides and herbicides to lawns and grounds; • pouring of waste oils, paints, solvents, etc. into local I kettleholes, lack of maintenance of shoreline; inadequate disposal of pet residue and dumping of trash or organic materials such as leaves or lawn clippings. Rectification'of these I practices is addressed by an educational program teaching the • tenets of ecologically sound "urban housekeeping". The target of the educational program should be the entire town, but most • especially the residents in close proximity to Lost Lake / | Knopp's Pond. I I 163 igure 36. Site Constraints for Selection of Best Management Practices. EXTENDED DETENTION POND > o • > o WET POND 3 OO03O INFILTRATION TRENCH INFILTRATION BASIN POROUS PAVEMENT OOOOOOOO WATER QUALITY INLET • •OO0OO-O GRASSED SWALE O O 3 3 • '•.O O FILTER STRIP PRECLUDE THE USE OF A BMP 3 CAN BE OVERCOME w/CAREFUL SITE DESIGN A GENERALLY NOT A RESTRICTION 169 I The increasing popularity of treatment of lawns by commercial fertilizing companies (e.g., ChemLawn) has negative • impacts for the water quality of the adjacent pond. Runoff from I lawns carries large amounts of fertilizer/ pesticides and herbicides into the storm gutters and eventually, into the lake. • In the case of abutting residences, delivery is directly to the | lakes. While not denying citizens the right to a greener lawn, the effect of these practices should be emphasized. Particularly _ in the case of commercial application, the amount and type of I chemicals, as well as the form and timing of application is ™ determined by a company which has no vested interest in' preserving water quality, only in "guaranteeing" results. • Residents should realize that the price of a greener lawn may I well include a greener lake. In more practical terms, the better the condition of the lake, the higher the resale value of the mm abutting homes. I Fertilizer management considers the proper timing and amount of fertilizer to optimize plant growth with minimal impact on the I pond (USEPA, 1988) Alternatively, substitution of low-phosphorus m compounds (e.g. Lakeside) or organic fertilizers (which do not leach out as easily) can be tried, a further step is • "naturalistic landscaping". Naturalistic landscaping reduces | the size of the lawn, replanting buffer strips with wetland shrubs and trees more capable of better nutrient and sediment _ control under low maintenance conditions. (Lake Cochuiate I Watershed Association, 1984). * Another important feature of this program is the reduction in • the practice of watershed residents using adjacent kettleholes m and like depression as a convenient dumping place for automotive oils, hazardous household chemicals or related liquid waste, and m abandoned materials such as appliances. This practice is I widespread and indicates a lack of understanding of the groundwater connection between these depressions and Lost Lake / Knopp's Pond. Thoughtless introduction of noxious or hazardous I materials into kettlehole has the potential to undo most of the • benefits arising from proposed improvements to the lake. . Shoreline maintenance should be a regular part of the | outdoor cleaning done by abutting residents. If not done, the bank may be destabilized and slump; putting unwanted earthen _ materials into the pond. Here again, planting of a vegetated I buffer strip can be useful way to consolidate the bank, B Additional suggestions are to be found in the "Guidelines for Waterfront Owners" handout prepared by the Clean 'Lakes Committee. • Another area of concern it prevention of gullying due to | unregulated runoff from road surfaces. Elsewhere, containment construction for the keeping the bank intact appears to be « deteriorated. A careful inspection of unimproved road surfaces I will be needed, as well as timely maintenance or repairs. This i i 170 I is also true for shoreline to prevent significant erosion or I potential bank failure. Most areas will have to be addressed by I the individual abutters. Anticipated Impact of Program The amount of phosphorus reduction that can be expected from I this option is difficult to precisely predict. Watersheds such as Martin's Pond Brook would benefit from watershed management and agricultural BMP's. Overall, an estimated range of between 5 I and 10% of the phosphorus would be eliminated. The actual amount of phosphorus reduction realized will be a function of the intensity at which local officials pursue implementation of BMP's I "in existing and future regulated activities. The chemical impact of the adoption of environmentally- sound practices on the phosphorus budget will probably be slight I (<2.0%), but impact on people's attitudes is the more important gain. As adjacent residents become aware of the land-pond connection, the less likely they are to commit environmental I abuses. Further, effort spend by individual abutters to clean up their shoreline translates into a constituency who and are more likely to prevent future degradation of the pond. While the lake abutters have the most to directly gain by an improved pond, I all the citizens of Groton share the benefits in their use of - • I Lost Lake / Knopp's Pond and Sargisson Beach. Cost, Permits and Summary I All the programs identified above are interrelated, though obviously at different scales.of public awareness. The town must strike the balance" between controlled development and protection of natural resources. Education is necessary to reinforce the I notion that the events in any part of a watershed, however distant, will affect the water down below (Dunne and Leopold, I 1978). The amount of money recommended for this option ($12,000) is obviously inadequate to directly clean up such a large watershed. Future funding may be available to pay for the cost of clean-up I of existing problems {see below). What the proposed money is slated for is to develop education materials which supplement the existing brochure and handouts. These help coordinate the town's I and individual's efforts at reducing sediment and nutrient loadings into water resources. With an educational program, no I environmental permits are invoked. Overall, these issues should be addressed with educational I materials that can be included in a "packet" produced for the I I 71 I watershed and lakeside residents. Compliance of the public with environmentally-sound practices will not be complete, but this • addresses those residents who would observe the proper measures • if only they were aware of them. Development of an educational slide/video program for presentation at town meetings provides a • useful medium to approach watershed residents. This will be used | to complement existing educational brochures, such as "The Groton Guide for Homeowners" which is a useful compendium of good _ environmental practices. Additional printing or reproduction of I this pamphlet would be very cost-effective, and costs should be ™ picked up by the program. Distribution of educational materials can be handled through the town; with local conservation • commissions, planning boards, and/or recreation departments I likely candidates to serve as clearinghouses for such information. Signage at the Public Boat Launch and on Sargisson • Beach are also productive ways to educate about existing town by- | laws and reinforce environmental considerations. Promotion of Martin's Pond Brook for the "Adopt-a-stream" program should be considered. Sources of information include state and regional • clearinghouses (see Appendix) . B In the future, a proposed state program for the reduction of • non-point sources has much promise for the Lost Lake / Knopp's | Pond watershed. Major funding ($50 M) is being sought for the Massachusetts Nonpoint Source Program. The proposed program is « analagous to the Massachusetts Clean Lakes Program; with the • effort and monies being spent on the watershed lands rather than — the lakes of the Commonwealth. Unfortunately, passage of this proposed legislation in the near future is dubious, given the I present fiscal state of Massachusetts. If and when these monies I are made available, the Lost Lake / Knopp's Pond watershed should make an effort to obtain this funding. It should make a good • candidate for this funding due to the importance of non-point • sources to the lake system nutrient budget, the large size of the watershed, and the visibility of the pond as a recreational resource. It should be emphasized that this is a future option, I which is at least three or more years away from realization. i• i i i i i 172 I I I WATERSHED MANAGEMENT I GROUNDWATER PROTECTION AND MANAGEMENT Elements of the Program I Protection of groundwater resources is an important issue for the long-term maintenance of drinking water quality in Groton. As a drinking water source, groundwater has several advantages over surface water sources including: lower costs, less land I requirement, negligible evaporation losses and better consistency of water quality. However, if groundwater is poorly managed or becomes contaminated, its recovery time is very slow (if at all) I and clean-up costs are very expensive. Increasing residential density in the Lost Lake / Knopp's Pond watershed will lead to additional introduction of potential pollutants into the I groundwater system, and the need for increased vigilance. The proximity of the watershed to existing and future well sites makes this a particularly important issue for the town. I The Whitney Pond well is now the major source of drinking water in Groton Center, with the Baddacook well being used as primary back-up source. Major primary (direct) and secondary (indirect) I recharge zones serving these town wells have been identified in the Lost Lake / Knopp's Pond watershed (Figure 37), and the outlet flow of Lost Lake is one of the major sources of Whitney I Pond. In addition, the Shattuck well (a secondary back-up water source located off Gibbet Hill) and the Shelter's Rd. area (designated as a potential drilling site) are within the lake system watershed. Since these recharge zones and the Lost Lake / I Knopp's Pond watershed have so much overlap, protection of water quality, whether of groundwater or surface origin, has a double benefit. Recent incidents, such as the finding of volatile I organic compounds (i.e., trichloroethylene) in private wells near the Four Corners area (Stewart, 1987) underscore the vulnerability of groundwater drinking supplies. I In considering all the sources of nutrients to Lost Lake / Knopp's Pond, particular attention must also be paid to local groundwater inputs, including the wastewater disposal systems I around Lost Lake / Knopp's Pond. The amount of phosphorus entering the lake system via this route is estimated to be 93 kg P/yr (see Nutrient Budget) . This constitutes about 24% of all I contributions to the overall phosphorus budget. While the best way to eliminate this loading is to build sanitary sewer lines in the vicinity of Lost Lake / Knopp's Pond; this option is currently outside the scope of possible Clean Lakes Program I funding. However, there are options at the discretion of the individual homeowner which can sharply reduce his or her contribution to the "greening" of the lake. These are considered I in a later section. I ?p£ H^i^lf 4^^;-^^^^°'t'"t'/^tt''^; £C M5 ^ ^^sM^16l^ ^v C /H •-%•- Saddacooi-,- r ^Ste^a y/—,- .'^^T^Ski-#£.**• f^M^fe °°;.d ^4- ]-^^^P?<^^ ..S^^^jj^^^^pg^^: VX^S^^^^^I^' 1 ii;sya7^Ji*^=^>^-' r-' /VT=: ''^fev^S^l^r^l]3"^'<£^ Area 2 - Potential Municipal Well Sites Primary areas of recharge to municipal wells. Area 3 - Major aquifers, primary stratified drift recharge areas to area 2 & primary till recharge area to area 1. Area 4 - Secondary stratified drift recharge ^& areas. rjfc Figure 37. Potential Well Sites and Recharge Zones NR - Non-significant recharge areas. 0 in the Lost Lake / Knopp's Pond Watershed. Scale 1 ; 25,000. (After : IEP, 1983) A fty--~r^^ V'x^ 174 I I Land Use Controls Land use patterns are critical for protection of underlying groundwater quality. At the town level, the major determinant of I future land use is the zoning by-laws, Groton is to be commended for having existing by-laws designed for the specific purpose of protecting groundwater. These bylaws were passed in town meeting in March, 1984 (Article 38, Zoning By-Laws of Groton). I This Special Regulation; Section 5.9, established "Water Resource Protection Overlay Districts" for the protection and preservation of existing and potential groundwater supplies. Primary and I secondary water resources district were created as overlays on existing town zoning. The water resource districts in the Lost Lake / Knopp's Pond watershed are shown in Figure 38. I Of particular importance are the three primary water resources districts. These areas are associated with the Whitney Pond well site, the Baddacook Pond well site, and the Shelter's I Rd area. Much of the land around the first two is already zoned as conservancy districts or otherwise subject to public usage (Figure 35) . If appropriate, additional purchase of open space I plots in the aquifer recharge zones could be funded by the Massachusetts Aquifer Land Acquisition Program (M.G.L. Chap. 286). The Shelter's Rd location includes the southern shoreline of Knopp's Pond. Most of the remainder of the Lost Lake / I Knopp's Pond watershed is classed as secondary water resource . districts, including all other shoreline properties as well as lands south of Route 119. Among the latter is the 560 acre site I of the so-called "East Village", located east of Sandy Pond Rd. This proposed development calls for 240 residential units and considerable business and commercial space, with residential I wastes to be disposed of via community leach fields (Hartford, 1988) . While actual specifications of this proposed development are in the preliminary stages, it is safe to say that the mere size of this development presents considerable potential loading I to the groundwater in an area of high concern. Review of the Groton water resource by-laws reveals a clear I intent to protect groundwater resources, but no well-defined way to determine water quality. This is critical for the detection of negative impacts to the groundwater. Mathematical models of groundwater loading are sufficient for the planning stages, but I in practice the burden of proof of negative impacts lies in the installation and regular sampling of monitoring wells. This type of system is useful in that it detects degradation trends at an I early stage, when containment and rectification of the problem is relatively simple (and inexpensive). I The need for monitoring wells should be dictated by the scale of development. While usually unnecessary for single home I residences, monitoring wells should be installed in the I I 175 Figure 38. Water Resource Protection Overlay Districts, Groton, MA. 1 = Primary Water Resources District. 2 = Secondary Water Resources District. 176 I development of light industry, commercial properties or I residential sub-divisions. The proposed "East Village" sub- division provides a convenient example. Groundwater movement into the Knopp's Pond area (Primary Water Resource District) I could be monitored by a series of wells along the Rte.. 119 corridor. It will be necessary to site the wells carefully so that impacts from Rte. 119 are distinguishable (some upgradient, some downgradient) . In addition, water quality in the local I small kettlehole ponds should be.measured to provide additional information regarding any advance of contaminants towards Knopp's Pond. It is recommended that a site-specific groundwater I monitoring program be an integral part of any final design for large scale developments in Groton. Like adjacent towns {e.g. Littleton), the cost of installation and regular monitoring of I these wells should be borne by the developer, as part of the overall environmental mitigation program. Groundwater concerns are not restricted to the Four Corners I area. However, in the upper Lost Lake / Knopp's Pond watershed, the existence of extensive wetlands helps to protect water quality in the secondary districts before it comes into contact I with the primary water resource district. Proposed building in the developable tracts of land in these identified recharge zones should incur similar constraints (as described above), which must I be considered when evaluating their individual and collective impact to groundwater quality. I Qn-site Wastewater Disposal Systems The present residential density in most of the Lost Lake / I Knopp's Pond watershed ranges from low to moderate, but is increasing rapidly. Groton Center will be served by sewer lines which will go to a sewage pump station and via a force main to a treatment plant in Pepperell. It has been proposed that the Lost I Lake community be served by a pressure sewer system and package treatment plant (Montachusetts Regional Planning Commission, 1978) . Costs associated with that plan were over $2 million a I decade ago, and are likely to be unreasonably high today. Near the lake, many residential lots are quite small, due to their original development as summer camps (see Historical I section) . As a result of age and conversion to full-time residency there is a mosaic of households which still rely on either cesspools or undersized tank and leachfield systems. I Given the small lot sizes, moderate to steep relief and the region's soils, several areas are susceptible to septic system failures. Rehabilitation of such systems was likely to require I individual pumping off-lot to suitable leach fields (Montachusetts Regional Planning Commission, 1978). Some I improvement might also be possible through installation of so- I I 177 I called "alternative" septic systems. Less costly ways to reduce _ or mitigate the effects while using existing systems are the use I of non-phosphorus detergents and proper maintenance and ™ inspection of septic systems (Lee and Jones, 1986) . Alternative Technologies for Septic Systems. There are a number of options to consider when faced with a I failing or inadequate septic system. The first option is to apply the proper maintenance and see whether the system responds. If the system is still clearly failing to meet performance I standards (i.e., Title V) reconstruction of the system may become ' necessary. In some cases replacement of a cesspool with a conventional tank and leachfield may be sufficient. Typical • replacement costs can run from $2,000 to $5,000. In other cases | the size of the lot or the pitch of the land may make conventional systems ineffective. Pumping the effluent to _ another parcel is possible, but seems unrealistic for the Lost I Lake community given lot sizes and locations. If not further ™ land is available there are potential ways to enhance performance through the use of alternative equipment or technologies. Some I of these options are shown on Table 27. Other options include I such approaches as sealed ("tight") tanks, waterless composting toilets (e.g., Clivus Multrum), and combined treatment systems (e.g., RUCK systems). i There are advantages and disadvantages associated with each _ of these options. Water conserving devices reduce the overall • amount of flow to the septic system, although they do nothing to • reduce the loadings or treatment of solid wastes to the septic system. Such devices are useful in reducing the amount of liquid • wastes ("greywater") emanating from faucets and showers. These | help prolong the functional lifetime of a septic system and may be particularly useful if the lot is plagued by high groundwater _ tables. Pumping or "pressure-dosing" sewage effluent to the • leachfield requires additional land, energy and maintenance ™ costs. This would only be recommended if additional land is available further from the lake. In some locations around Lost • Lake, placement of leachfield back from the lake is less I advisable due to the proximity of primary water resource districts. Both holding tanks and waterless toilets essentially • store solid wastes for decomposition and disposal later. Holding I tanks may be the only option in small size lots that are close to the groundwater table, but their high installatipn and frequency of maintenance do not recommended them elsewhere. Composting I toilets suffer from the same problems, although they only store H the solid wastes ("blackwater"), and thus need less frequent maintenance or pumping. The RUCK system incorporates a separate • system from treatment of "blackwater" before the effluent rejoins | the "greywater" component for joint discharge into a leachfield. i i 178 I I I Table 27 TYPICAL ALTERNATIVE EQUIPMENT AND TECHNOLOGIES FOR I ONSITE WASTEWATER MANAGEMENT Item Remark Low flow appliances Water usage can be reduced by 2 I to 30 percent. Low-flow toilet {0.75 gal/flush) Water usage for flushing reduced by 85 percent over conventional I toilet (5 gal/flush). Air-assisted low-flow toilet Water usage .for toilet flushing I (0.5 gal/flush) reduced by 90 percent over conventional toilet (5 gal/flush). Air-assisted shower (0.5 to Water usage for shower reduced I 0.75 gal/min) by S7.5 percent over conventional shower (4 gal/min). I Well pumps (multistage turbine type, Used to pump small amounts of typically 0.25 to 0.5 hp) septic tank effluent to heights up to 600 ft. I Septic tank + sand filter + shallow Suitable for locations with high leachfields groundwater and for locations with limited soil depths (2.5 to 5.0 ft). I Septic tank + sand + pump filter Suitable for locations with high drip irrigation system - groundwater, for locations with limited soil depth (2.5 to 5.0 ft), and for locations with inadequate I open area for the placement of conventional leach fields. I Septic tank + mound system Suitable for locations with high groundwater and for locations with limited soil depths (2.5 to 5.0 ft). I Septic tank + pump + extra length Suitable for soils with percolation leachfield rates between 120 to 400 min/inch. Leachfield design based I on an application rate' of 0.05 to 0.1 gal/ft • day. I I I I 179 I The advantage of this system is the reduction in nitrogen and _ phosphorus obtained in the blackwater pretreatment. A further I advantage is the need for a smaller sized drain field on the lot. * This system has been installed in New England (including lake- side properties) and is being monitored by Massachusetts • authorities in order to set codes for their use. The major I disadvantage for the RUCK system is its high cost of approximately $12,000 to $16,000, but this may decrease as the system is more widely accepted and installed. i There is no single technology or system that will be _ appropriate for all situations in the Lost Lake / Knopp's Pond I watershed. As with any septic system design, the • characteristics of the site dictate the best practical design. Some of the common constraints in the area are small lot size and • high groundwater table. Under these circumstances, | technologically advanced systems may make the difference between a buildable and non-buildable lot, and is thus part of the price • of lakeside residence. On the other hand, retrofitting of older I systems is likely to be much more difficult to enforce, although there is sufficient authority in the Title V regulations to produce compliance (or eviction). The most successful approach I is likely to be one of cooperation and shared problem-solving • between the local health officials and the individual homeowners. i Mitigation of Impacts by Existing Septic Systems. Even with present septic systems and usage, there are ways to I mitigate some of the negative effects. Decreasing the use of • phosphorus-containing detergents is one of those ways. It is estimated that roughly one/third of phosphorus loadings to a • septic system is due to The Massachusetts Coalition of Lake and | Pond Associations is -currently promoting legislation on the state level which will ban the sale of phosphorus-laden detergents in • Massachusetts. Unfortunately, similar legislation has failed to I pass in the past. However, this does not preclude lake abutters from actively promoting this idea among their neighbors. Educational information that will facilitate is available from I several sources; for example, several booklets are available on I the relationship of detergents and fertilizers to lake quality (Lake Cochituae Watershed Association 1984 a, b, c), including • the "Groton Homeowners Guide" produced by the Groton Clean Lakes | Committee. Another reduction is possible from improved efficiency in I existing on-site wastewater units. Improving the operation of ™ on-site wastewater disposal systems has been the subject of considerable recent literature (e.g., Veneman 1986). The two • most critical site variables related to the performance of in- | ground disposal systems are the depth to groundwater and the type i i 130 I of soil below the system (Veneman 1986) . The greatest possible I vertical distance to groundwater and an intermediate percolation rate are desirable. While dilution-by groundwater may be substantial, conversion of pollutants to harmless or immobile I forms is often minimal once a substance enters the saturation zone. Slow movement of effluent through a large aerated zone of soil with high adsorptive capacity is the optimal situation, but I these conditions are not often achieved in practice. One major stumbling block is the need for the disposal system to handle the volume of waste delivered to it without causing a I back-up of flow. The slower percolation rates associated with some soils preclude their use for on-site systems, and most states have laws which set the minimum acceptable percolation I rate. Not many states set standards for the maximum percolation rate, however, and this causes many systems to be underdesigned. The actual percolation rate will be determined by the permeability of the biofilm layer which forms in the aerated soil I below the leaching area (Lavigne 1986), not just the soil permeability. When sized according to the percolation rate of highly permeable soils, leaching areas may be insufficient to I pass the design flow. Further, effluent passing into the highly permeable soil may move into the groundwater too quickly for effective removal of contaminants through soil adsorption I processes. Other important operational considerations are the detention time in the settling tank (preferably >1 day), waste delivery I rate (preferably continuous enough to maintain the microbial community but with breaks to regenerate soil capacities), and available leaching area (preferably as great as possible). Both I system design and maintenance-affect these parameters. .The movement of liquid through the pipes, chambers, and soils of the system is critical"to operation; clogging or flow restriction must be avoided. This involves not only proper design and I maintenance, but control over what is placed in the system as well. Solids such as disposable diapers and liquids such as greases should not be routed into on-site wastewater -disposal I systems (DiLibero 1986). If groundwater quality is to be improved and preserved, it is imperative that all disposal systems be properly maintained and I upgrades be encouraged. While regulatory procedures are typically inadequate to deal with enforcing maintenance codes (Janaros 1986), it is possible to mandate maintenance and enforce I the statute. Mandating system upgrades is usually more difficult as a consequence of grandfather clauses and a lack of appropriate I data on the impact of inadequate systems. One approach is for the town to pass a by-law requiring I septic system renovation or replacement when a property is sold I I 181 I or transferred to new owners. This would not penalize present M septic systems, but would mean that new owners would assume some I of the cost of cleaning up and maintaining water quality in Lost * Lake / Knopp's Pond. This does not seem unreasonable, as the new owners were likely attracted to the area by the proximity of the I lake, and improvements in this resource are likely to appreciate I local house values. Currently, the average maintenance interval for the units at I Lost Lake / Knopp's Pond is about 3 years. DiLibero (1986) has recommended an inspection interval of six months to two years, _ with cleaning and maintenance as warranted by inspection. I Stricter inspection and maintenance of septic systems might • improve efficiency (Veneman and Wright, 1986). These inspections would probably fall under the duties of the Groton Health • Department or Nashoba Valley Sanitarian. | Means of insuring regular inspection and maintenance of « septic systems in the town may need to be stressed. Inducements I or penalties to encourage timely pumping and maintenance of the septic systems may be used. Some ways of encouraging this are by offering a partial credit on local taxes or by linking the cost I or access to town privileges (e.g., use of town dump or beach) • with septic system maintenance. One alternative approach to implementing an effective | disposal system maintenance program involves taxing all residences for the cost of an annual inspection and pumping, and _ having the Town arrange for the service (much as with trash I collection or sanitary sewer operation. The cost of an annual • inspection and cleaning ranges from $90 to $150 in the northeastern United States, depending on geographic area and the • distance over which septage must, be transported for ultimate I disposal. The likely return in decreased nutrients to the lake has to I be weighed against an additional burden being placed on the town or region health officials. This is not to imply that some improvement is not possible, simply that it is likely to most I cost-effectively accomplished by educational means that by I attempting revision of existing town by-laws to enforce compliance. What is more important is that the relationship • between septic systems and lake quality be made exceedingly clear I to the lake abutters, so that they understand that how their actions affect the lake resource. . _ The legal methods described above are effective but may not • be palatable to the local population. People resent or resist efforts to force an expense on them, regardless of its ecological • benefit. Education of the local residents will be required to | popularize this idea. Again, this is best addressed by the use of i i 182 i I educational materials and the efforts of a group to actively I promote such knowledge. I Anticipated Impact of the Groundwater Protection and Management Program The amount of phosphorus reduction that can be expected from I this option is difficult to precisely predict. Over the long term, hook-up to sewer lines would eliminate the bulk of the groundwater loading due to septic systems. However, it is I unrealistic to expect that sanitary sewer lines will be available in the near future. Educational brochures and information can be expected to increase public awareness and watershed performance I in the short run (1-2 yr), but will need to be vigorously and continually pursued to keep the public participation viable. Improvement of septic system performance from 90% to 95% I phosphorus retention produces an additional slight reduction to the phosphorus budget. The apparent existing high efficiency of phosphorus retainage may be a joint product of septic system I performance and interception by the macrophyte cover. Using the 95% efficiency estimate, a reduction of 4"7 kg of phosphorus is projected. While this is a small amount it is an appreciable portion of the Lost Lake / Knopp's Pond phosphorus budget (12%). I This option, by itself, will not dramatically change water quality in Lost Lake / Knopp's Pond, but would bring the lake under the projected critical loading. Further if improvements in I existing systems could be coupled with removal of some of the cesspools in the area, a reduction of from 15% may be possible, with a best possible figure of 24% (total elimination of all I septic systems). I Cost, Permits '_and Summary An education program emphasizing the connection between the watershed and Lost Lake / Knopp's Pond is recommended. The I elements of this program should include information on the effects of septic systems on groundwater quality, the expected response of the lake (already seen) to decreased nutrient loadings, and the potential benefits (or loss thereof) accruing I to the local residents around Lost Lake / Knopp's Pond. Educational information regarding the impact of development on groundwater and good watershed practices which minimize that I impact are included in the Appendix. A useful pamphlet already tailored to be specific to Lost Lake / Knopp's Pond is available (i.e, Groton Homeowner's Guide). The real desire, however I intangible, is to instill a sense of responsibility for the water I leaving one's property, be it in a stream or a septic waste. I I 183 I Costs of such an educational program revolve around printing of additional pamphlets and distribution of this brochure. In • addition, a slide presentation can be put together that | illustrates the message. Town meetings, publicity connected with the fishing events, school excursions, poster boards at the • swimming beach, and Conservation Commission public meetings are I appropriate occasions to promulgate these concepts. A series of informational articles that address relevant issues of watershed management can be prepared. The release of these articles can be • timed to coincide with town meetings and summer recreational m season. These articles are often worth republishing at regular intervals to refresh older residents and inform newer ones. • The costs of this education program include expanding and reprinting of appropriate lake and watershed-related brochures _ (printing 1,000 copies at approximately $0.80/per brochure). I Preparation of an educational slide show and/or video (with • additional copies) can be expected to cost $3,500. Preparation of news articles is estimated at about $600. Making an education • poster board and appropriate signage for the town beach is slated | at about $1,000. The cumulative cost of this educational program is $6,000. The educational program does not require • environmental permits, per se, except those routinely required in I the Clean Lakes Program for granting of Phase II Implementation Funds. For these agencies and their addresses consult Table 31. In summary, groundwater protection and management is an I important facet for the management of the Lost Lake / Knopp's Pond, as it holds the greatest potential for reducing phosphorus • loadings in the important groundwater component. Since mandated | sewer connections often prove both unpopular and unenforceable, an educational program is recommended. This educational packet _ should address not only the groundwater to septic system I relationship, but include information on a variety of related ' environmental topics, stressing the impact common practices can have on nearby lakes and ponds. . _ • i i i i i i 184 i I I I RECOMMENDED MANAGEMENT APPROACH I After consideration of the lake and watershed characteristics and the available options for improving or preserving the existing conditions, the following actions are recommended for I the management of Lost Lake / Knopp's Pond. 1. Funds should be sought to install a dam underdrain to allow potential dewatering of Lost Lake by 5 feet, with I structure should be used to conduct a winter drawdown at regular intervals {2-3 years) to improve water quality and reduce the density of nuisance littoral macrophytes. This structure would also allow for a limited I hypolimnetic release in summertime. Initially, a temporary siphoning arrangement - should be used for an experimental drawdown to test effects of wells and I impacts on macrophyte beds. 2. Localized macrophyte relief can be provided by I installation of bottom barriers. A purchase of this material should be used for both public (Sargisson Beach) and private applications. The town can act as purchasing agent for bulk purchase discounts with lakeside residents I buying material from town as needed. 3. A surface water nutrient reduction program in the Lost I Lake / Knopp's Pond watershed to reduce nutrient loadings from diffuse runoff is recommended. Educational programs should be used to establish best management practices in I both residential and agricultural areas. This program should also promote the concepts of sound environmental practices for individual residences in the immediate vicinity of Lost Lake / Knopp's Pond; addressing such I topics as control of lawn runoff, dumping of hazardous materials in adjacent kettleholes, car maintenance, etc. I 4. Similarly, a groundwater management and protection program in the Lost Lake / Knopp's Pond watershed is recommended. Existing zoning by-laws protect the integrity of the groundwater in Groton, including I potential future water supplies, and should be vigorously enforced, with judicious implementation of groundwater monitoring. Educational materials and town involvement I for encouraging regular maintenance and inspection of septic systems is very important, including encouragement of newer technology septic systems and the use of non- I phosphorus detergents throughout the watershed. I I 185 I Discussion of Recommended Options Management option #1 provides a long-term management option | for controlling an number of problems in Lost Lake / Knopp's Pond. This include reduction of recycling within, control of w macrophytes in the lake, and maintenance of shoreline areas. I Given the time delay (2 to 3 years) associated with the implementation of funding (via Phase II) , it is highly recommended that the local authorities and townspeople conduct an I experimental drawdown of Lost Lake with a temporary siphon. This • allows evaluation of the impact of drawdown on nearby wells, downstream resources, macrophyte beds and local aesthetics. • Coordination will need to be made with Grotonwood, the Groton | Highway Department and the Groton Conservation Commission to plan, the timing of these water withdrawals. . - Option #2 provides localized relief from macrophytes in the ™ near future. The combined application to the public and private beaches allows partial funding for the public areas under the • Clean Lakes Program, while individual homeowners can create or | enlarge private access points or beaches. The application at the public beach provide an excellent demonstration of the • capabilities and "feel" of the the product to interested parties. I Option #3 and #4 involve development of an educational package to address a number of issues in the watershed. While I these issues have been sub-divided into "surface water" and • "groundwater" concerns, they really are the same issue, namely the reduction or elimination of diffuse non-point sources. It is • advantageous that the town has existing water resource zoning by- | laws and a relatively up-to date brochure {Groton Homeowner's Guide). This helps to reduce the cost of this option package. _ However, an educational program"has limits on its ability to " I redress current problems. Large expenses for watershed clean-up * would probably be sought from the proposed non-point source program, if and when it becomes available in the future. • Delay of the pond drain installation until Phase II funds are available seems likely due to the high costs involved. On the • other hand, delay in the dissimination and adoption of best I management practices in the watershed will be very costly if the majority of land use decisions are made in the next few years. The present period appears to be a critical point in time for the I watershed, as much land is being converted into residential I developments. Poor watershed management could cause water quality to deteriorate and reduce or even negate1improvements • eventually won elsewhere. Thus, while awaiting Clean Lakes | funding, a town-sponsored lake restoration program could be initiated. The elements of this low-cost restoration package _ would be temporary siphoning, some amount of benthic barriers, I and reprinting and distribution of the Groton Guide. i™ i 186 i I The costs of the full slate of lake management options, including installation of the pond drain total to $131,300. I Since approximately 75% of these expenses are assumed by the Clean Lakes Program, Groton's share is about $60,000. This may seem a large sum to raise at the local level, and clearly, it is I a step not likely taken. However, postponing or ignoring town expenditures will only lead to increased (sometimes precipitously) costs when restoration is attempted. Delay will I only increase what seems a large financial burden into a larger one. Decision-makers in Groton need to consider all these I factors when making the town's choices. Anticipated Impacts of Proposed Management Actions I The expected changes in the phosphorus budget of Lost Lake / Knopp's Pond following various management options is shown in Table 28. A reduction of 5-10% is anticipated through decreased watershed nutrient loadings following adoption of best management I practices. This amount may be even higher when a non-point source program is available. Increased efficiency of septic system maintenance and pumping will reduce from 8 to 12% of the I phosphorus budget. Water level drawdown can decrease the phosphorus budget by 5%, but is more important in improving recreation. Depending on the intensity with which the watershed I resident environmental practices education program is pursued, a reduction of 1-2% is expected. Control of macrophytes by bottom barriers affects a small area and does not change the phosphorus nutrient budget. Overall an expected reduction of 19-29% of the I present phosphorus budget is estimated. These improvements would reduce phosphorus levels to below I the the Vollenweider critical value for phosphorus loading. This says that water quality will change the trophic status of the lake to a more moderate or mesotrophic condition. It is important to remember that these estimates of trophic conditions I are just that. The Vollenweider analysis is less valid when the lake does not act like a completely mixed reaction (Dillon, 1975). The incomplete circulation between the two lakes violates I this condition. Further the large amount of macrophyte biomass is likely to act as a sink for much of the incoming phosphorus. At the same time, the very high iron content of the water and I sediments is going to make mobilization of phosphorus more difficult. Overall, there should be reasonably clear water in Knopp's Pond and lower Lost Lake and summer water quality in this I area should be better than the Vollenweider model indicates. I I I I (87 I I TABLE 28 I ANTICIPATED IMPACTS OF PROPOSED MANAGEMENT ACTIONS ON THE _ PHOSPHORUS BUDGET OF LOST LAKE / KNOPP'S POND • Total phosphorus load (kg/yr) . 382 • Calculated critical load (kg/yr) 2 349 • Calculated permissable load (kg/yr) v 174 Reduction necessary to reach critical load (%) 9 • Reduction.necessary to reach permissable load (%) 54 • Anticipated reduction {%) resulting from: Water level control 5% H Bottom barriers 0% • Watershed best management practices 5-10% Resident environmental practices 1-2% • Septic system maintenance 8-12% Groundwater management and protection 0%3 I• 4 Full mandated sewer hook-up [For comparison only] 24% . • Total anticipated phosphorus load reduction 19-29% i 1 - Load above which excessive productivity is expected on a frequent basis 2 - Load below which excessive productivity is expected only very rarely. 3 - Importance is based on reduction of future loadings. • 4 - Potential future action, but generally not an fundable options under the Clean Lakes Program. I i i i 188 i I I Monitoring Program A monitoring program will be necessary to assess the success of remedial actions and aid in the formulations of appropriate management policies. Specific objectives of the monitoring I program for Lost Lake / Knopp's Pond and its watershed include monitoring progress of in-lake water quality, evaluation of the effectiveness of the drawdown, and determination of water quality I throughout the watershed. The elements of the program and associated cost estimates are presented in Table 29. I Macrophyte density should be expressed as both percent cover and biomass per unit area for covered and uncovered locations. Field investigations in May (pre-treatment) and late August (post-treatment) are recommended for the first year to verify I diagnostic phase mapping and establish vegetative transects for later monitoring. I Monitoring will include surface water quality sampling during operations, as well as a three year post-treatment monitoring of the lake and watershed. The timing of the initial monitoring I should coincide with the pond drain construction operations to insure that excess suspended solids and turbidity are prevented from passing downstream. It is expected that most work will be done when the outlet flow is minimal to avoid passage of I suspended solids. Prevention of downstream problems is best accomplished by the cooperative planning of the project between the contractor and the environmental monitoring body, probably I the Groton Conservation Commission which will sets the Order of Conditions under which work may proceed. • Following construction of .the pond drain, a sampling program ™ of three in-lake stations should be maintained to ascertain resultant water quality. The suggested sampling is at the three surface water stations monitoring during the diagnostic phase I (KP-3s,KP-4s,KP-5s). Alternatively, the two deep basins at Lost Lake / Knopp's Pond (KP-3s,KP-5s) can be used, with an additional station for the bottom waters at Knopp's Pond (KP-3b). The timing ( of the samplings should be seasonally (i.e., 4 times/yr). Parameters of interest include: total and total filterable phosphorus, ammonia, nitrate and Kjeldahl nitrogen, pH, • •-• • conductivity, chlorophyll a_, and Secchi disk transparency. • Temperature-dissolved oxygen profiles should be included. In the second and third years, sampling would be restricted to the two • surface stations (KP-3s, KP-5s). Monitoring of the groundwater is included in the overall _ package to allow assessment of the success of groundwater • protection and management. Four wells (these may be chosen from ™ existing wells or monitoring wells installed in compliance with - i the water resource by-laws) are sampled twice a year, in spring i i 189 I TABLE 29 I COST OF THREE YEAR MOTORING PROGRAM ASSOCIATED WITH MANAGEMENT OPTIONS I Estimated Item or Task Cost ($) • First Year 1.) Macrophyte Monitoring • Field Evaluation of plant density; May and August 3 days @ $400/day. 1,200 2.) Ground water Assessment I Sampling of 4 wells (existing) @ 2 times/ year B Analysis for NO-,NH-,TKN,TP,TSP, Fe alkalinity, Cl, cond, pH and FC; @ $150/sample. 1,200 • 3.) In-Iake water quality monitoring | Sampling at 3 sites @ 4 times/year. Analysis for NO-,NH3,TKN,TP,TFP • alkalinity, Secchi, chlorophyll a., • TSS, cond, pH, FC; T, DO @ $185/sample. 2,220 ™ 4.) Tributary monitoring Sampling at 8 sites @ 1 times/year. I Analysis for NO,,NH3/TKN,TP,TFP I alkalinity, TSS, cond, pH, Cl, flow FC, FS ; @ $185/sample. 1,480 • 5.) Labor costs for monitoring | Six days @ S400/day 2,400 - First year total 8,500 _ Second Year 1.) Macrophyte Monitoring 1 inspection @$500. " 500 i 2.) Ground water Assessment Sampling of 4 wells @ 2 times/yr _ _ Analysis as above, @ $165/sample , ' 1,300 I 3.) In-lake WQ monitoring — Sampling at 2 sites 0 4 times/yr. Analysis"as above, @ $200/sample. 1,600 • 4.) Tributary monitoring I Sampling at 4 sites @ 1 times/year. Analysis as above @ $200/sample. ' 800 • 5.) Labor costs for monitoring . | Four days @ $450/day 1,300 Second year total " 5,500 _ Third Year (Items 1-5) Same as second year ; - - • - Third year total " ' 5,500 ': Total Costs $19,500 i i 190 i and fall, which correspond to the annual high and low groundwater level. Parameters of interest are those indicated on the table. This level of monitoring is recommended for all three years. Reduction of surface nutrient loadings in the watershed will be monitored by an annual sampling of eight tributary stations, corresponding roughly to those sampled during the diagnostic phase. The parameters to be sample on indicated on the table. The number of stations is reduced to 4 over the second and third year. 19 I I I FUNDING ALTERNATIVES I Several sources of funding may be available for management activities in the Lost Lake / Knopp's Pond watershed, but the Clean Lakes Program represents the single most important and I versatile source of support. The initial funding needs of the proposed project could best be met through the Massachusetts Clean Lakes Program. Other potential funding sources include the Federal Rivers and Harbors Program, Federal Land and Water I Conservation Fund, the Massachusetts Self Help Program, the Aquifer Lands Acquistion Program, and the Agricultural Preservation Restriction Program. These might be used for I acquisition of lands in the watershed, and improvement of the dam structure. Notes on potential funding sources are given in I Table 30. Up to 75% of the costs associated with capital investments in the management of the lake are reimbursable under the Clean Lakes Program. Maintenance and operation expenses are not I reimbursable, a real consideration in the choice of management alternatives. Expenses associated with actions covered by other programs are not reimbursable unless it can be demonstrated that I funds could not be obtained from the appropriate programs. The proposed groundwater and watershed education program is eligible for Clean Lakes funding. I At the present time the Massachusetts Clean "Lakes Program is limited by a fiscal spending cap. This spending cap provides for funding of ongoing lake restoration projects, or projects to I which it has prior commitments. Applications for Phase II funding may or may not be accepted in the next year. Given these circumstances and the potential for delays of up to three years before future state action, funding of initial restoration I options (temporary siphon, etc.) should be sought at the local I level. I I I I I 193 I TABLE 30 I POTENTIAL FUNDING SOURCES FOR THE PROPOSED RESTORATION OF LOST LAKE / KNOPP'S POND I Funding Source Level Notes I Massachusetts Clean Lakes 75% Sound Program; July 1 Program (Ch- 628 of the application deadline; Acts of 1981, DEQE) likely source. I Federal Clean Lakes Program 50% Financially deficient (sec. 314 of PL 92-500, USEPA) future funding possible. I Small Watershed Protection 50% Requires high cost benefit Program (PL 83-56, SCS) ratio. I Rivers and Harbors Program 50% Jan. 15 deadline; can be (Division of Waterways, DEM) applied to recreational enhancement. I Federal Land and Water 50% Acquisition of lands for Conservation Fund; outdoor recreation. Need to I Division of Conservation have up-to-date open space Services, EOEA (Federal plans. Funds available. Pass Through) I Mass. Urban Self Help (up to) Acquisition and development Chap..933, Acts of 1977 90% of parks and recreational lands for communities with I Cons, and Rec. Commissions Aquifer Lands Aquisition 100% for Monies available if public Program, Ch. 286, Sec 5 studies water supply wells are I and 20, Acts of 1982. under 50K; to be developed. (DEQE) total,250K I Agricultural Preservation 100% of Considerable funds have been Restriction Program (APR) purchase committed to this program, Ch. 780, Acts of 1977 of develop- (Food/Agriculture) ment rights. I Non-Point Source Pollution 75% Proposed legislation only Control Program $5 million annual budget I (DWPC) over ten year period. I I I 194 I I I I I CONTACT AGENCIES Funding by the Massachusetts Clean Lakes Program requires the review and approval of this document by the Division of Water Pollution Control, Division of Fisheries and Wildlife, and I Massachusetts Historical Commission. The petitioning organization (Town of Groton) must provide evidence of public access and a certificate of title to the project site. Zoning or I land use actions resulting from consideration of the information in this report may be subject to approval under Executive Order 215 (Fair Housing). Most activities would be coordinated by the I Groton Board of Selectmen and/or Conservation Commission. Permit requirements necessitate review and action by the Executive Office of Environmental Affairs (MEPA Unit) and the I Groton Conservation Commissions (regarding actions in water resource areas). Other agencies and the likely permit I requirements are indicated on Table 31. I I I I I I I I I I 95 Table 31. PERMITS RND OTHER flPPROvRL PROCESSES ASSOCIRTED HIrll THE PROPOSED HflHnGEHEhT ftCTIOHS PERHI r/CERfl FI CATE/LICEHSE/RPPROVFIL conrACT AGEHCV REVIEH TIhE flPPLICRDILITV TO tinHRGEMEMT nCTIOMS. HIIICII MUST BE OBTAINED riND ADDRESS COflVS> TeHporary Pernanent Pond Doiton Matershed Siphon Siphon Uiidar-drain Barriers Man-sgenont Title to Project Site Lakes Section, DMPC, DEQE Hone, subrtit w/oppl. X K Lynan School, Uestvieu 81dg. Uestborough, HR 01531 508-366-9181 I ntergot/erttnantal Rgreenenl Lakes Section, DUPC, DEQE Local Approval req'd Lynan School, Mestvieu Bldg. Uastborough, HR 01581 508-366-9181 Fair Housing CEO 2I5> Exec. Office Connuni tios/Daval - Hona, Cor.tact OECO 100 Canbridge St., RM for determination Boston, HR 02202 Connission Against Discrinination MR Conn. Against Discrimination 120 1 Hshburton Place Boston, Hfl 02108 Uago Rate Conpliance Bept. Labor and Industries Hone, subtiit ML thin 100 Canbridge St., llth Floor 15 days after work Boston, tin 02202 done. HO Env. Policy Ret CEHF Ex»c. Off. Env. flffairs CMEPO? 30 X 100 CAnbridga St., 20th Floor Boston, HA 02202 617-727-5830 Hatur^l Prograti Hfl Natural Heritage Prog., DFM Hi stori cal Cowiission Hfl Historical Co OpproM. 30 XX CO Boylston St. SubniI letter of Boston, HF) 02116 finding M/appl. 61?-^2?-85rO Div. Fisherias and Mildlifa Oiv. Fisheries and Wildlife 15 XX Field Headquarters Uestborough, Mil 01531 508-366-1^0 US ftrny Corps of Engrs conrncT REVIEU TIHE nPPUCRBILITV TO HfttinGEHENr ncriOHS. HIIICIl MUST DE rmo OPPRESS CimVS> Tartpor-sry Parnanant Pond Botton Hater shod Siphon Siphon Undor-dr.iin Carriers OVIPC Duality Pornits Soclion, DHPC, U-QE X X 1 Hi nl*.r St. Boston, HD 02100 M*-tlands Protection Ret Grolott Consarvati on Connission TOHH Hall Groton, Hfl X Pet-nit roquirad by agency. ? P«rnit n-ay or nay not bo required; agoticy HAlcas doternination. « If CIR raquirad, final Approval Mill not ba givo" until EIR is reviau ** Rovieu of projact by Appropriate agoncg initiated by this r«port. V*M Ho staLul-Oi-y linit, longest nhen EIR is rt-quirvd- I I I I I I I I ENVIRONMENTAL EVALUATION I Environmental Notification Form Appendix B contains the Environmental Notification Form (ENF) I which must be filed under the Massachusetts Environmental Policy Act (MEPA) . The MEPA unit will evaluate the proposed actions and their potential impacts and make a determination regarding the need for an impact study prior to implementation. The ENF also I serves as a useful summary document for the project. Preparation of a detailed Notice of Intent, which is filed with the Conservation Commission under the Wetlands Protection Act, may I satisfy questions likely to be raised by the MEPA unit staff. I Comments by Interested Parties Copies of this report were sent to the Groton Board of Selectmen, the Groton Conservation Commission, the Groton I Department of Public Works, the Groton Planning Department, the Groton Clean Lakes Committee, the Groton Recreation Department, the Division of Water Pollution Control, the Division of I Fisheries and Wildlife, the Massachusetts Historical Commission, and the Natural Heritage Program for review. Comments by these parties have been addressed in this report or appended to it (Appendix), as warranted. Written and verbal comments received I by citizens and agencies during the course of the project have also been addressed"and/or summarized. I Three public meetings were held by BEG, Inc. during the study period to inform interested parties of progress and solicit comments. Summaries of the comments and questions raised at the I first (11/12/87), second (7/20/88) and third (3/8/89) public meetings are given in the Appendix. Comments made by meeting participants have been incorporated into this report wherever possible. Review and comments by officials of Groton have been I similarly incorporated. I Relation to Existing Plans and Projects The proposed lake restoration and management plan is entirely I consistent with all stated objectives and community-sponsored activities in the watershed. The recommended procedures are consistent with the Groton Zoning Board, Groton Open Space and Recreation Plan (1987) and the existing Master Plan (Elliot, I 1963) which is currently under revision. I I 199 I The proposed in-lake actions will improve lake conditions without significant impact to downstream flows or water quality. • Construction of a permanent pond drain, prefaced by the I installation of a temporary siphon arrangement, with provide long-term management capabilities. Some amount of detailed study • will be necessary to assure downstream residents that water I levels will not be excessive. Since anticipated flows are in the range of normal spring runoff, flooding problems are not expected. Metering the flow of either the siphon or drain and I monitoring flows provide additional control of this operation. • Bottom barriers provides a means to extend control of • macrophytes at the public beach as well as relief to individual | homeowners. Adoption of best management practices in the watershed lead to improvement in surface water quality and helps • protect future abuses from developing. Individual practices in I the immediate vicinity of the shoreline need redressing with * regard to sound environmental stewardship of the land. Groundwater quality inputs to Lost Lake / Knopp's Pond will I benefit conscientious enforcement of the existing water resource I protection district zoning. This is particularly relevant in the case of anticipated major building in the watershed in the near • future. Another critical facet of groundwater improvement is | encouragement of septic system maintenance and/or replacement of inadequate systems. Future planning in the town of Groton should _ also encourage extension of residential sanitary sewer lines. iI i i i i i i i i 200 i I I I FEASIBILITY SUMMARY I An evaluation of possible management options at Lost Lake / Knopp's Pond was conducted and those alternatives which were not appropriate or feasible were eliminated. The remaining and I recommended options include: redesign and construction of a pond underdrain, installation of benthic barriers to provide localized macrophyte control, and institution of a watershed education and protection program addressing both surface and groundwater I sources. The cost of the recommended options and the local share required is given in Table 32. The tentative implementation I schedule and associated costs are presented in Table 33. The recommended options constitute a long-term lake and watershed management program. In the current budgeting climate I the restoration package is probably best sought for in two distinct steps. The first recommended step includes installation of a temporary siphon to evaluate the impact of a drawdown, purchase and application of benthic barrier material and I reprinting of the current available brochure detailing sound environmental practices for homeowners. Following a positive evaluation, the second and more lasting step is the construction I of a pond underdrain, additional purchase of benthic barriers is so merited and a more comprehensive watershed education program (slide/video) stressing reduction in watershed nutrient loading through a combined approach of best management practices, good I septic system maintenance and continued vigilance for- maintaining groundwater quality"through enforcement of existing town by-laws. A positive abutter attitude and good watershed practices are I essential for any management plan that hopes to protect and enhance the quality of the waters of Lost Lake / Knopp's Pond. A three year monitoring program is included for checking progress I and restoration success. Potential funding sources have been discussed, with the Massachusetts Clean Lake Program targeted as the likely primary I source for the lake restoration options. Other funding sources are available for improving dam facilities (Rivers and Harbors) if not through Clean Lakes. Land acquistion moves for aquifer or I agricultural land protection are also available. The recommended options will improve lake water and recreational quality in Lost Lake / Knopp's Pond. Groton can apply for Phase II funding for one, two or all of the options at its discretion and not I disqualify itself for future funding applications. I I I 201 i i TABLE 32 i LOCAL COSTS OF RECOMMENDED MANAGEMENT OPTIONS FOR LOST LAKE / KNOPP'S POND i Groton' s Options Available Funding Cost Share i Redesign of Outlet a. Temporary Town-sponsored $12,000 $12,000 Siphon b. Permanent Clean Lakes Program $76,000 $22,750 Siphon* Chap. 628 c.Pond Drain Clean Lakes Program $131,300 $36,575 i Installation Clean Lakes Program $20,500 $16,375 of bottom (partial funding for barriers Sargisson Beach) Watershed Mgrmt Clean Lakes Program $18,000 $4,500 i a . BMP ' s b. Env. Pract . _c. GW Protect. d. Septic Sys . Project Chap. 628 1• Monitoring a. Pond Drain " included above b. Bottom Barriers $3,400 i c. Watershed Mgmt $5,500 d. GW protection $4,000 $12, 900 $3,225 PROJECT TOTAL COSTS $182,700 ' $60,675 1 State funds requested under Chap. 628 $122,025 • 1 * Not recommended by BEG. i 202 i TABIE 33 OE JCIICHS, , KHD TiSSCCIWn-D COSTS Spring Summer Fall Winter . Spring Simmer Fall Winter Total lean/Task yr 1 Yr 1 Yr 1 Yr 1 Yr 2 Yr 2 Yr 2 Yr 2 Yr 3 Yr 4 Costs Grant Arrangements w/DEQE, Line up Potential Additional Funding Sources X X X Tenporary Siphon Permit Construct . Drawdown 1,000 5,500 5,500 12,000 Pond Underdrain Permits Survey and Engineer. Construct. Restoration 5,000 11,000 11,000 84,700 13,000 124,700 Bottom Barriers Permit Application 500 20,000 20,500 Watershed Mgmt Survey of Heeds Program Town Program Develop. Presentation 2,000 1,000 5,000 4,000 • 12,000 ro O Groundwater Mgmt Survey of Needs Program Town (>J Program Develop. Presentation 1,000 1,000 3,000 1,000 6,000 Monitoring 2,500 2,000 2,000 2,000 5,500 5,500 19,500 Total Cost ($) * 8,500 33,000 19,000 89,700 15,500 2,000 2,000 2,000 5,500 5,500 $182,700 * Temporary Siphon costs are included in Pond Under drain costs, so not counted twice. 204 I I I REb'EKENCES I APH&, AWWA, AND WPCF. 1985. Standard Methods for the Examination of Water and Wastewater (16th Edition) . Published jointly by the authoring I associations. ASAE. 1982. Proceedings of the Third National Symposium on Individual and Small Community Sewage Treatment. St. Josephs, MI. I Baystate Environmental Consultants, Inc. 1987. Diagnostic/Feasibility Study of Forge Pond, Westford MA.. East Longmeadow, MA.. I Brezonik, P.L. 1973. Nitrogen Sources and Cycling in Natural Waters. USEPA 660/3-73-002. Butler, C. 1848. History of the town of Groton. T.R. Marvin Publishers, I Boston. MA.. Caldwell, D.W. and G. Cook. 1981. Hydrology and water resources of Groton, I Massachusetts. Technical Report No. 1. Environmental Hydrogeology Center, Boston University, Boston, MA. I Chapra, S. 1975. Comment on: "An Empirical method of estimating the retention of phosphorus in lakes" by W.B. Kirchner and P.J. Dillon. Water Resour. Res. 11:1033-1034. I Collins, R.L. 1985. Letter to Ms. Marjorie Eger regarding status of water rights to Lost Lake and Knopp's Pond. I Cooke, G.D., E.B. Welch, S.A. 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Water Resour. Res. Ctr., Univ. Mass., Amherst, MA. « Higgins, G.R., and J.M. Colonell. 1971. " Hydrologic Factors in the • Determination of Watershed Yields. Water Resour. Res. Ctr., Univ. Mass., Amherst, MA. • Jones, J.R., and R.W. Bachmann. 1976. Prediction of phosphorus and chlorophyll levels in lakes. JWPCF 48:2176-2184. ' • Kirchner, W.B., and P.J. Dillon. 1975. An empirical method of estimating the retention of phosphorus in lakes. Water Resour. Res. 11:182-183. Kopp, J.F., and G.D. McKee. 1979. Methods for Chemical Analysis of Water I and Wastes. USEPA 600/4-79-020, Wash., D.C. Lake Cochituate Watershed Association. 1984. Fertilizers and Your Lake. | MDWPC Publ. # 13,808-ll-200-10-84-C.R. Larsen, D.P., and H.T. Mercier. 1976. Phosphorus retention capacity of • .lakes. J. Fish. Res. Bd. Canada 33:1742-1750. • Larsen, G.J. and B.D. Stone. 1980. Late Wisconsin Glaciation of New • England. Symposium Proceedings. Kendall-Hunt Publishing Company, Dubuque, IA. i 206 I Lee. G.F., and R.A. Jones. 1986. Evaluation of detergent phosphate bans on I water quality. Lakeline, Vol. 6, #1. NALMS, Washington, D.C. Martin, D.M., and D.R. Goff. 1972. The Role of Nitrogen in the Aquatic Environment. Contribution #2, Academy of Natural Sciences of I Philadelphia, PA. Martin, E.H. 1988. Effectiveness of an urban runoff detention pond - I wetlands system. J. Env. Engr. 114 : 810-827. Massachusetts Division of Fisheries and Wildlife. 1911. Fishery Survey of I Knop' s Pond. MDFW, Westborough, MA. Massachusetts Division of Fisheries and Wildlife. 1928. Fishery Survey of I Knop's Pond. MDFW, Westborough, MA. Massachusetts Division of Fisheries and Wildlife. 1960. Fishery Survey of I Knop's Pond. MDFW, Westborough, MA Massachusetts Division of Fisheries and Wildlife. 1978. Fishery Survey of Knop's Pond. MDFW, Westborough, MA. I 1977. Baseline Water Massachusetts Division of Water Pollution Control. Quality Studies of Lost Lake / Knopp's Pond. MDWPC, Westborough, I MA. Massachusetts Division of Water Pollution Control. 1981. Baseline Water Quality Studies of Lost Lake / Knopp's Pond. MDWPC, Westborough, I MA. Massachusetts Division of Water Pollution Control. 1985. Baseline Water Quality Studies of Lost Lake / Knopp's Pond. MDWPC, Westborough, I MA. Massachusetts Division of Water Pollution Control. 1979. Certification I for Dredging, Dredged Material Disposal, and Filling in Waters. 314 CMR, Vol. 12-534. ' - Massachusetts Division of Water Pollution Control. 1985. Massachusetts I Surface Water Quality Standards. Publication #14371-115-100-3-86-CR. Massachusetts River Basin Planning Program. 1984. Agricultural Water I Quality Study. United States Department of Agriculture and Massachusetts Agricultural Experiment Station. I May, V.A. 1976. A plantation named Petapawag. Some notes on" the history of Groton, Massachusetts, Edited and published by the Groton Historical Society, Groton, MA. I Mills, E.L., Green, D.M. and A.S. Schiavone, 1987. Use of zooplankton size to assess the community structure of fish population in I freshwater lakes. Trans. Am. Fish. Soc. 116 : 369-378. , I I 207 I Mitchell, D.F., Wagner, K.J. and C. Asbury. 1988. Direct ir.easurerr.ent of groundwater flow andd quality as a llaka e management tool. Lake and I Reservoir Management 4(1} : 169-178. Mitchell, D.F., Wagner, K.J., Monagle, W. and G.A.Eeluzo. 1989. "The • littoral interstitial porewater sainpler: doing "LIP" service to your I lake" . Presented at1 9th Annual North American Lakes Management Society meeting, St. Louis, MD, November 1988. m Montachusett Regional Planning Commission. 1978. Proposed Montachusett- • Nashua areawide water quality management plan summary and draft environmental impact statement. Fitchburg, MA. • Mbtts, W.S. 1985. Hydrogeology of West Holyoke and adjacent areas. Amherst, MA. » National Oceanographic and Atmospheric Administration. 1986. Climatography m of the United States, Number 20, Climatic Summaries for Selected .Sites, 1951-1980. NQAA, Asheville, NC. • National Oceanographic and Atmospheric Administration. 1987. Climatography of the United States, Number 21, Massachusetts. NQAA., Asheville, NC. • National Oceanographic and Atmospheric Administration. 1988. Climatography of the United States, Number 22, Massachusetts. NQAA, Asheville, NC. _ North American Lake Management Society. 1985. A Layman's Bibliography of • Lake Management. NALMS, Merrifield, VA. Nurnberg, G.K. 1984. The prediction of internal phosphorus load in lakes | with anoxic hypolimnia. Limnol. Oceanogr. 29:111-124. Oglesby, R.T., and W.R. Schaffner. 1978. Phosphorus loadings to lakes and I some of their responses: Part II: "Regression models of summer phytoplankton standing crops, winter total phosphorus, and transparency of New York lakes with known phosphorus loadings. . . I Limnol. Oceanogr. 23:135-145. " ' I Reckhow, K.H., M.N. Beaulac, and J.T. Simpson. 1980. Modeling Phosphorus • Loading and Lake Response under Uncertainty: A Manual and Compilation • of Export Coefficients. USEPA 440/5-80-011, Wash., D.C. Reynold, C.S. 1980. Phytoplankton periodicity :" its motivations, " " I mechanisms and manipulations. Ann. Report. Freshwater Biol. Assoc.. • 50: 60-75. - • " " , I Robert S. Means Company. 1989. Means Heavy Construction . Cost Data, 1989. | E. Norman Peterson Publishers, Kingston, MA.. Sawyer, C.N. -1947. Fertilization of lakes by agriculture and urban I drainage. N.E. Water Works Assn. .J. 61: 109-127. ."._., m Schueler, T.R. 1987. Controlling urban runoff : A practical manual for • planning and designing urban BMP's. Washington Metropolitan Water I Resources Planning Board. Washington, D.C. i 208 I Smith, V.H. 1982. The nitrogen and phosphorus dependence of algal biomass I in lakes: an empirical and theoretical analysis. Limnol. and Oceanog. 27:1101-1111. Soil Conservation Service. 1988. Soil Survey of Middlesex County, I Massachusetts, Eastern Part. Open File Report. United States Department of Agriculture and Massachusetts Agricultural Experiment I Station. Sopper, W.E., and H.W. Lull. 1970. Streamflow Characteristics of the Northeastern United States. Penn State Univ. Bull. 766, Univ. Park, I PA. Stauffer, R.E. 1981. Sampling strategies for estimating the magnitude and importance of internal phosphorus supplies in lakes. EPA-600/3-81- I 015. Corvallis Environmental Research Laboratory. USEPA, Washington, DC. I Stewart, R. 1987. "Well water contamination found in Gilson Rd. area". Groton Herald (9/4/87 issue) . Groton, MA. I Stone, B.D. and J.W. Peper 1982. Topographic control of the deglaciation of eastern Massachusetts: Ice lobation and the marine incursion. In Late Wisconsin Glaciation. G.J. Larson and B.D, Stone (eds.) . I Kendall-Hunt Publishing Ccnpany. Dubuque, IA. Tchobanoglous, G. and E.D. Schroeder. 1985. Water Quality. Addison-Wesley I Publishing Company, Reading, MA. United States Environmental Protection Agency. 1976. Quality Criteria for Water. USEPA, Washington, D.C. I United States Environmental Protection Agency- 1988. The Lake and Reservoir Restoration and Guidance Manual. Office of Water Criteria and I Standards Division. Non-Point Sources Branch. Washington, D.C. United States Geological Survey. 1979. Ayer Quadrangle Sheet, 7.5 Minute I Series. USGS, Bethesda, MD. United States Geological Survey. 1977. Limiting Values for Water Quality Alert System. USGS Circular, August 22, 1977. USGS, Trenton, NJ. I United States Geological Survey. 1984. Gazetter of Hydrologic Characteristics of Streams in Massachusetts - Merrimack River Basin. I USGS Water-Resources Investigations Report 84-4284. United States Geological Survey. 1987. Water Resources Data. Massachusetts - Rhode Island Water Year. USGS Water-Data Report MA- I RI-85-1. University of Massachusetts (1975), Land use and vegetative cover mapping. Ayer Quadrandangle. Massachusetts Map Down Program, University of I Massachusetts, Forestry and Wildlife Management, Amherst, MA. I I 209 I Vollenweider, R.A. 1968. Scientific Fundamentals of the Eutrophication of Lakes and Flowing Waters, with Particular Reference to Nitrogen and I Phosphorus as Factors in Eutrophication. Tech. Rept. to OECD, Paris, I France. Vollenweider, R.A. 1975. Input-output models with special references to the I phosphorus loading concept in limnology. Schweiz. Z. Hydrol. 37:53- Vollenwieder, R.A. 1982. Eutrophication of Waters: Monitoring, Assessment, i• and Control. OECD, Paris, France. Wagner, K.J. 1986. Biological management of a pond ecosystem to meet water | use objectives. Lake and Reservoir ftenagement 2: 53-61. Wagner, K.J., and R.T. Oglesby. 1984. Incompatibility of common lake I management objectives. Pages 97-100 in: Lake and Reservoir ™ Management. Proc. of the Third Annual Conf. NALMS. USEPA, Washington, D.C. I Wetzel, R.G. 1983. Limnology. 2nd edition. Saunders Co., Philadelphia, PA. . • Winter, T.C., LaBaugh, J.W. and D.O. Rosenberg. 1988. The design and use of a hydraulic potentiomanometer for direct measurement of _ differences in hydraulic head between groundwater and surface water. I Limnol. Oceanogr. 33: 1209-1214. ™ Zen, E. 1983. Bedrock Geologic Map. USGS and MA DPW, Boston, MA. • Zoning By-Laws of the Town of Groton, MA. i i i i i i i i zio SflHPlE COULECriOM (HID PROCESSIHG HETMODOtOGV FOR BEC SURVEVS RECOHHEHDED RECOMMEHnEn PftRfWETER COLLECTION/TEST TVPE STD. HETH EPfl MErHOO OTHER HETHOD SRttPLE SIZE SrtHPLE PftESERV. HOLDING TIME Hator aatipla collection General surface uater Grab 105 2.a DEQE StornM«t Grounduater Molls Grab 105 2.a SHOCF Poreuater Grab or conposite 105 2.afib MLB HI4HB Soap-ago Volunatric nun LEE Sediment sanpla collodion Cora or Ekrian grab U&L CI1.12 UftB Malar discharge Volunatric H6L CH.5 SCS ro Total phosphorus Colorinotrie •121 C,F 365.1--! H«L CH.? 100 Rafrigarata/froazo 10 Tot«l filtorablo phospttor us Coloritiotric n,C,F 365.1-1 HftL CH.? 100 Filter, 18 rafrigerata/frcraza Solubla r«activo phosphorus Colorinatric 121 R,F 365.1-3 H(tL at.7 100 Filter, 18 ro Mitrata nitrogen Colorinotrie 118 D 353.3 HftL CH.P 100 112501 to pll<2 Hnnonia nitrogen Colorinotrie 11? n,B 350.2 HfliL CH.? GOO II2S01 to pll<2 Total kjald^hl nitrogen Colorinatric 120 B 351.3 HfiL CH.? GOO H2S01 to pH<2 Jf.it Voriporatura Tharrti stor 212 170-1 H6L CH.2 Irntediato Dissolvod oxygen oloctrode 121 ft,B,C,F 360.142 MftL CH.6 or Uinklor litr«tion to O Cllinkler> SRHPLE COLLECrlOH UNO PROCESSING HETHODOLOGV FOR BEC SURVEVS RECOMMENDED RECOMMENDED coLLEcriOH/rEsr TVPE STD. HETH EPfl METHOD OTHER HEHIOD SRNPLE SIZE SflMPLE PRESERV. HOLniNG TIME Percent oxygen saturation Calculation iron TVDO UttL CH.6. Po ten ti one tr i c 123 150,1 H&L CH.8 2 Total alkalinity Titration 103 310.1 H&L CH.8 200 Refrigerate 21 Chloride Titralion 10? fl,B,C 325.3 HftL CH.? 100 Refrigerate «« Specific conductance Platinized electrode 205 120.1 HSL CH_? Refrigerate ^ Secchi disk transparency Visual HftL CH.2 Innediate P Turbidity Nopholonetrie loo.i 50 Darkness 21 ro rot*l solids 209 n 160.3 HftL CM.? 50O Refrigerate 160 Total volatile solids Gravimetric (ignited) 209 E 160.1 HSL CH.? 500 Refrigerate 168 Total suspended solids Gravimetric 209 B 160.1 HfiL CH_? 500 Refrigerate 168 (filtered/dried) (Irsenic fllonic absorption 303 E 206. 1S2 50 111103 to pll<2 6 MOIllftS Cadni UM filonic absorption 303 fl 213.1*2 50 MN03 to pH<2 6 rionths Chronion Rtonic absorption 303 fl 218. 1&2 50 MHO 3 to pH<2 6 nonlhs Copper fltonic absorption 303 fl 220.1H2 50 IIN03 to pM<2 6 months SftMPLE COLLECriOH nNO PROCESSIHG HETHODOLOGV FOR DEC SURVEVS RECOMMENDED RECOMMENDED COLLECTIOH/rESr TVPE STD. HETH EPft HETIIOD OTHER METHOD SfiHPLE SIZE SflMPLE PRESERV. HOLDING TIME Chr or as not«»d> Iron Rtonic absorption 303 A 236.182 50 HH03 to plK2 6 nonths Color!notrie 315 B Atonic Absorption 303 fl 239.152 50 IIM03 to [>H<2 6 nonths ntonic absorption 303 A 213. 50 IIH03 to pll<2 6 Months Mercury ntonic absorption 303 F < 215.1&2 500 IIH03 to pH<2 6 Months 215.5 Mickal ntonic absorption 303 ft 219.Ift2 50 HM03 to pll<2 6 tionths fttonic absorption 303 C 20&.152 5O HH03 to pll<2 nontl>3 Zinc ntonic absorption 303 289.112 50 IIH03 to pM<2 no — Oil Cxtractionygr-avinatric 503 n,C 113.1 1000 H2S01 to pll<2 Polijchlorinated biphonyls Gas chrotvatographic FR Pasticidas Organic content Gravinatric 209 E 160.1 Grain aiza distribution Gr«Vi notric HftL CM.5 UftB Sedinont settling faaturas Volunatric M&B Fecal coliforn Incubatad filtar 909 C B&H III.C.2 125 Riafrigcrata count Facal straptococci Incubated filtar 910 B B&li III.0.2 125 Rafrigorata plata count SRHPUE COLLECriOM flHO PROCESSING HErilODOLOGV FOR DEC SURVEVS RECOMMENDED RECOHHEMOED PfiRflHETER COLLECriON/TEST TVPE STO. HETH EPfl METHOD OTHER METHOD SftHPLE SIZE SftMPLE PRESERV. HOLDING TIME Chr or as notod) Chlorophyll a Entraction/absorption 1003 G.3 M Cll.2.5.2.1«t3 HftL CH.10 1000 Rofrigorata in dark Biological collodions Ptvjtopl ankton Grab or tuba conposito. 1002 B.2*3 H CH.2.2&3 UftL CH.10 Lugol's 6 nonths Zooplankton ISO UH tiash not toM 1002 B-2&1 H CH.2.213 M&L CH.ll For rial in 6 nonths Macrophijtas Eknan or nartual 1001 0-1 H CII.3 H»L CH.2O For-«al in 18 100-1 D-2a«b Hacroinv«rtabra.tQ3 D-nat or EkHan dradg« 1005 B.3.a.6 H Cll.1.3.2*3 U4L Of. 12 rtlcohol or fornalin 6 Months 1005 B.I H CH.1.1.W2 Fish Gill not, trap not 1006 fl.l.abd M CM.5.2.2,1 NJL CH.6, Alcohol or fornalin 6 Months or saino H CH.S.2.3 Phytopiankton abundance Microscopic call count 10O2 C.I UftL CH.10 1002 E-lfcl 1002 F.lt,2 1002 H-2 Zooplankton abundance/ Microscopic count 1002 C.I H CH.2.1H5.3 HftL CH.ll size distribution 1002 E.lfil 1002 F-? 1002 H.2 Hacrophyto abund-anca/ Visual 1001 B tl CII.3 U9L CH.20 distribution 100-1 C.I, 241 1001 D.341 Hacroiiwortobratei abundance Visual or Microscopic 1005 C H CH.1.1-5 UftL CI1.12 aK^nination Fish abundance/growth rata Visual and Microscopic 1006 B H CH.5.1 HJL CH-15ft16 scala oxanination Soft sedinant depth Probo to refusal DEQE Lake bathynotry Sonic fathottator H8L CH.l DEOE HorphoMatric laka foaturas Physical/calculation MftL Cll.l I i I I REFERENCES FOR METHODOLOGY: Unless otherwise given, Std. Method is from APHA-AWWA-WPCF 16th edition. I Unless otherwise given, EPA Method is from EPA-60Q/4-79-G2Q. Other references: B&W = Bordner and Winter, 1978. Microbiological Methods for Monitoring the I Environment. EPA-600/8-78-Q17, USEPA, Cincinnati, OH. DEQE = Department of Environmental Quality Engineering, Division of Water Pollution Control, 1988. Clean Lakes Program Guidelines. I Publication #15, 487-52-2QQ-2-88-CR, DEQE, DVPC, Westborough, MA. FR = Feaeral Register, 40 CFR, Part 136, Oct. 26, 1984. LSE = Lee. 1977. A device for measuring seepage flux in lakes and I estuaries, Limnol. Qceanogr, 22:140-147. MWA = Mitchell, Wagner and Asbury, 1988. Direct measurement of groundwater flow and quality as a lake management tool. Lake Reserv. Manage. 4:169-178, I MWMB = Mitchell. Wagner, Monagle and Beiuzo, 1989. The Littoral Interstitial Porewater Sampler: Paying "LI?" service to your lake. Lake Reserv. Manage. 5:fin press). I NJL = Nielsen, Johnson and Lampton, 1983. Fisheries Techniques. AFS. Bethesda, MD. P = Preisendorfer, 1986. Secchi disk science: Visual optics of natural waters. Limnol. Oceanogr. 31:909-926. I 5CS = Soil Conservation Service, 1975. Engineering Field Manual for Conservation Practices. USDA, SCS, Washington, DC. SMDCF = Scalf, McNabb, Dunlap, Cosby and Fryberger, 1981. Manual of I Groundwater Sampling Procedures. NWWA, Worthington, OH. W = V'eber, 1973. Biological Field and Laboratory Methods. EPA-600/4-73-OQ1, USEPA, Cincinnati, OH, I WLB = Winter, LeBaugh and Rosenberry, 1988. The design and use of a hydraulic potentiomanometer for direct measurement of differences in hydraulic head between grounowater and surface water. Limnol. Oceanogr. 33:1209-1214. I W&B = Walsh and Bemben, 1977. Disposal and Utilization of Hydraulically Dreaged Lake Sediments in Limited Containment Areas. Publication #92, Water Resour. Res. Center, UMASS, Amherst, MA. I W&L = Wetzel and Likens, 1979. Limnoiogical Analyses. W.B.•Saunders, I Philadelphia, PA. I I I 215 216 I I I I I I I APPENDIX A. • Educational Information About Land and Wastewater • Management for Minimization of Groundwater Pollution • and Watershed Best Management Practices. I I I I I I I I I I I I AN ANNOTATED BIBLIOGRAPHY OF USEFUL PUBLICATIONS Bolger, R.C. 1965. Ground Water. Educational Series £3. Commonwealth of I Pennsylvania, Dept. of Internal Affairs, Harrisburg, PA. Although slightly outdated, this prirr.er clearly explains processes and phenomena associated with ground water. A discussion of well develooinent I is included. Brown, K.W. 1980. An Assessment of the Impact of Septic Leach Fields, I Home Lawn Fertilization and Agricultural Activities on Ground Water Quality. K.W. Brown and Associates, College Station, TX. This technical document discusses the results of ground water I investigations in sandy soils. -The impacts of wastewater disposal, lawn fertilization, and agricultural activities on ground water resources are described in conceptual and experimental terms. A model for determining I the land area necessary to support a given activity without excessive I ground water pollution is presented and applied. Connecticut Department of Environmental Protection. 1984. A Watershed Management Guide for Connecticut Lakes. CTDE?, Water Compliance Unit, I Hartford, CT. The process of eutrophication is described and the importance of controling phosphorus is emphasized. Sources of information for evaluating I lake condition are presented. Sources of pollution are discussed and recommendations for controling inputs are given, including tips on I minimizing residential contributions. Klessig, L.L., N.W, Bouwes, and D.A. Yanggen. 1983. The Lake in Your I Community. Univ. of Wisconsin Extension Service, Madison, WI. This booklet describes lakes and lake processes, including natural aging and accelerated eutrophication. Management techniques, limitations, I and costs are given. The formation of lake management districts is discussed, and additional sources of information are listed. I Lake Cochituate Watershed Association. 1984a. Detergents and Your Lake. MDWPC Publ. # 13,810-21-200-10-84-C. R. I The role and behavior of phosphates irr the environment are discussed in layman's terms. The composition of detergents and the use of phosphate as a builder are described. Alternatives to phosphate detergents and I associated limits are discussed, and possible approaches to reducing detergent phosphorus inputs to the environment are described. Attempts at I legislating detergent phosphorus reductions are reviewed. The publication I concludes with a long (although incomplete} list of cleaning products and their phosphorus content. • Lake Cochituate Watershed Association. 1984b. Fertilizers and _ Your Lake. MDWPC Fubl. 3 13,3GS-11-200-1Q-84-C.R. • The use of fertilizers, their composition, and natural processes affecting them are described in layman's terms. Interactions with the I hydrologic cycle and the role of fertilizer in the eutrophication of I surface waters are explained. Fertilizer requirements for typical lawns are given, and the hazards of overfertilization are described. The • substitution of natural landscaping Cor maintenance-intensive lawns is I recommended wherever possible, and tips are given for achieving an attractive residential setting through appropriate plantings and selective _ controls. I Lake Cochituate Watershed Association. 1984c. Septic Systems • and Your Lake. MDWPC Publ. 3 13,807-14-2QO-10-84-C.R. I The proper management of septic systems and problems resulting from • improper design or lack of maintenance are described in layman's terms. I Alternatives to conventional wastewater disposal systems are discussed and techniques are suggested for repairing poorly functioning systems which represent a health hazard or threat to environmental quality. The relation • of system design and maintenance to ground water quality is emphasized. B North American Lake Management Society. 1985. Starting and Building and | Effective Lake Association. NALMS, Washington, D.C. This booklet describes types of organizational arrangements for " • managing a lake. Discussions include'the formulation of objectives, fund ™ raising, and organizational by-laws. North American Lake Management Society. 1985. A Layman's Bibliography of Lake Management. NALMS, Washington, D.C. • A lengthy list of popular articles and technical papers relevant to the management of lakes is presented, A breakdown by key words is provided. I Pastor, D., and C. Alleva (editors). 1986. Water: Life'Depends On It. • Reprints from the Citizens' Bulletin. CTDEP, Hartford, CT. | This.collection of articles deals with water and man's influence on it. One very informative article lists facts and fiction regarding water I supplies and notes conservation/pollution prevention methods. Other • - -- i • i i I articles introduce components of aquatic systems and describe their role in I system ecology. Veneman, P.L.M, , and W.R. Wright (Editors). 1986. On-Sits Sewage Disposal. I The Society of Soil Scientists of Southern New England, Storrs, CT. This collection of papers from a recent symposium covers the range of Itechnical, economic, social, and regulatory issues associated with on-site wastewater disposal. Conventional and advanced on-site treatment systems are described, maintenance recommedations are made, and the legal and regulatory options for dealing with ground water pollution are discussed. IWhile technical in nature, most presentations are clear and comprehensible. I I I I I I I I I I I I I I I SUMMARY OF KEY POINTS RELATING TO MAN'S INFLUENCE ON GROUND WATER Jjeteroents and Other Cleaning Acents | 1. Except where water contains excessive quantities of dissolved substances ("hard" water), phosphorus is an unnecessary component of cleaning • agents; clothes and dishes are unlikely to be detectably cleaner, and no I health hazard is created by the elimination of phosphorus from cleaning agents. . 2. Cleaning agents can contribute up to 75% of the phosphorus entering • disposal systems, and usually provide at least 30% of the phosphorus • input from households where phosphate detergents are used. 3. If a detergent does not contain phosphorus, it usually will state this • on the container. Most phosphate detergents list the weight fraction | comprised by phosphorus. Liquid cleaners tend to contain less phosphorus than powdered forms. • 4. Legislation calling for a ban on phosphate detergents or a restriction • of the allowable phosphorus content is currently being considered by the Commonwealth of Massachusetts. Support is needed. . Garbage Grinders • 1, Garbage grinders cause unnecessary loading of solids and nutrients to wastewater disposal systems, resulting in a need for more frequent • maintenance and a higher potential for system failure and ground water | pollution. 2. Composting of garbage is a much more environmentally sound method of _ disposal/ if done properly. • L_awn Fertilizers 1. If properly applied at an appropriate dosage, fertilizer can enhance a • lawn without gross ground water pollution, but some addition of I contaminants to the ground water must be expected. 2. Overfertilization or improper application of fertilizer - can be a major • source of ground water contamination by phosphorus, nitrogen, and - J biocidal compounds, resulting in a health hazard in many instances. 3. Maintenance of a lush green.lawn of one or a few species represents an unnecessary expenditure of time and resources to satisfy a questionable • perception of beauty or order. • 4. The use of many species of natural vegetation maintains potentially valuable diversity and requires less money and effort to maintain. To • the discerning eye, a natural landscape is far more attractive than a | close-cropped grass lawn. Recycling of nutrients in a natural landscape results in less ground water contamination. » On-Site Wastewater Disposal ™ 1. Improper placement of systems (choice of sites) is a major cause of system inefficiency and resultant ground water contamination. • 2. Improper installation or settling/upheaval can negate proper design and | siting of a system; care and forethought are critical elements of installation. • 3. A vertical distance of at least 6 ft between the point of discharge to • the soil and the ground water table is necessary to minimize i i i I environmentally tolerable cerf ormance of a system. I 4. Cesspools provide considerably less treatment of wastes than conventional systems, require more maintenance to operate properly, are more prone to failure, and can no longer be legally installed. I 5. For cesspools and conventional tank and leachfield systems/ treatment will be insufficient to control nitrogen release into the around water. More than 90% of the nitrogen put into the system will enter the ground water as potentially hazardous nitrate. Dilution of effluent by I percolating rain water or the ground water supply itself is necessary to avoid a health hazard. 6. Alternative treatment methods include systems which separate blackwater I (toilet wastes and garbage) and greywater (shower, sink, and washing machine water) and treat each appropriately/ systems that recirculate effluent for further treatment, and systems which have no effluent (holding tanks). While more expensive to install or maintain, these I systems have less environmental impact than conventional systems. Their use should be encouraged in environmentally sensitive or densely populated areas not served by a community sewerage system. I 7. An on-site wastewater treatment system functions in the same capacity as a municipal wastewater treatment plant, only at an individual site level. As with large treatment plants, maintenance of an on-site system I is essential to its proper operation. Failure to spend a little time and money on system inspection and maintenance can result in the need to repair or replace the system at a much larger cost to the owner and I environment. 8. On-site systems should be inspected every 6 months to 2 years, depending on the intensity of use. If the lower limit of the floating scum layer or upper limit of the settled sludge 'layer exceed design specifications I (too close to outlet port), removal of accumulated solids is needed. If the available volume in the settling tank provides less than a one-day detention time, solids removal is needed. I 9. To avoid clogging of pipes, large solids and solidifying substances should not be put into the system. Problem materials include diapers, sanitary napkins, cigarette butts, garbage, and greases. Clogging of leaching areas by such materials is a major cause of system failure. I 10. To avoid upsetting the biological balance of the system (an active microbial community is essential to proper function), caustic solutions, cleaning agents, and other potentially biocidal compounds should not be I put into the system. 11. Water conservation results in longer detention times in the settling tank, greater breakdown of inputs, less build-up of sludge, and lower maintenance costs. I 12. There are many alledged remedies and products available for the restoration of failed systems and for improving system treatment efficiency. Despite some potentially valid claims, _there is no hard I evidence that any of these actually works. The best solution to septic system problems is to prevent their occurrence. I Ground Water in General 1. There is no magic underground river or lake that supplies ground water. Percolation and infiltration of rain water is the only substantial I source of replenishment. Contaminants on the surface of the land or in the soil may be carried with percolating water into the ground water • supply. | Ground water moves and is replaced much more slowly than most surface waters. Creation of a ground water problem will therefore have a • longer-term impact than pollution of surface waters. I Where wells and septic systems are employed, some portion of the water consumed in each household is certainly derived from the wastewater of other households in the same subsurface drainage basin. Renovation of I wastewater prior to its entry into the ground water is therefore • critical to the prevention of health hazards. Placement and depth of a well and the water demand placed on it will • determine the corresponding zone of contribution. A shallow well with a | relatively great demand may have a zone of contribution that extends into the wastewater discharge area of the same or neighboring " • properties. Even proper treatment of wastes prior to discharge into the I soil may be insufficient to maintain appropriate ground water quality in such wells. Major sources of contamination (e.g., large motelsf housing complexes, • and landfills) may create an expanding, attenuating plume of polluted • ground water which moves vertically and horizontally away from the source in the down-gradient direction. The surface location and intake depth of wells in the area will determine which ones become i contaminated. i i i i i i i i i i i I I Best management practices (cont.) I Streamside Management Zones (Buffer strips): Considerations in streamside man- agement include maintaining the natural vegetation along a stream. limiting livestock access to the stream, and where vegetation has been removed planting buffer strips. Buffer strips are strips of plants (grass, trees, shrubs) between a stream and an area I being disturbed by man's activities that protects the stream from erosion and nutrient impacts. I CRITERIA REMARKS 1. Effectiveness a) Sediment Good to excellent, reported to reduce sediment from feedlots on 4 percent slope by 79 percent. I b) Nitrogen (N) Good to excellent, reported to reduce nitrogen from feedlots on 4 percent slope by 84 percent. c) Phosphorus (P) Good to excellent, reported to reduce phosphorus I from feedlots on 4 percent slope by 67 percent. d) Runoff Good to excellent, reported to reduce runoff from feed' lots on 4 percent slope by 67 percent. I 2. Capital Costs Good, moderate costs for fencing material to keep out livestock and for seeds or plants. 3. Operation and Excellent, minimal upkeep. I Maintenance 4. Longevity Excellent, maintain itself indefinitely. I 5. Confidence Fair, because of the lack of intensive scientific research. 6. Adaptability May be used anywhere. Limitations on types of plants I that may be used between geographic areas. 7. Potential Treatment With trees, shading may increase the diversity and Side Effects number of organisms, in the stream with the possible reduction in algae. I Conservation tillage, animal waste management, live* 8. Concurrent Land Management Practices stock exclusion, fertilizer management, pesticide management, ground cover maintenance, proper • construction, use, maintenance of haul roads and I skid trails. I Source : USEPA, 1988. I I I I I Best management practices (Cont.) I Maintain Natural Waterways: This practice disposes of tree tops and stash in areas away from waterways. Prevents the buildup of damming debris. Stream crossings are constructed to minimize imoacts on flow characteristics. I CRITERIA REMARKS 1. Effectiveness I a) Sediment Fair to good, prevents acceleration of bank and channel erosion. b) Nitrogen (N) Unknown, contribution would be from decaying debris. c) Phosphorus (P) Unknown, contribution wouid be from decaying debris. I d) Runoff Fair to good, prevents deflections or constrictions of stream water flow which may accelerate bank and channel erosion. I 2. Capital Cost Low, supervision required to ensure proper disposal of debris. I 3. Operation and Low, if proper supervision during logging is main- Maintenance tained, etherise S160-S800 per 100 ft stream. 4. Longevity Good. I 5. Confidence Good. 6. Adaptability Excellent. I 7. Potential Treatment None identified. Side Effects I 8. Concurrent Land Proper design and location of hauJ and skid trails; Management Practices Streamside management zones. I Grassed Waterways: A practice where broad and shallow drainage channels (natural or constructed) are planted with erosion-resistant grasses. CRITERIA REMARKS I 1. Effectiveness a) Sediment Good to excellent (60 to 80 percent reduction). b) Nitrogen (N) Unknown. I c) Phosphorus (P) Unknown. d) Runoff Moderate to good. I 2. Capital Cost Moderate. 3. Operation and Low, but may interfere with the use of large equipment. Maintenance I 4. Longevity Excellent. 5. Confidence Good. I 6. Adaptability Excellent. 7. Potential Treatment None identified. I Side Effects 8. Concurrent Land Conservative tillage, integrated pest management, Management Practices fertilizer management, animal wajste management. I Source : USEPA, 1988. I I I I I I Best management practices (cont.) Street Cleaning: Streets and parking lots can be cleaned by sweeping which removes large dust and dirt particles or by flushing which removes finer particles. Sweeping actually removes solids so pollutants do not reach receiving waters. Flushing just moves I the pollutants to the drainage system unless the drainage system is part of the sewer system. When the drainage system is part of the sewer system, the pollutants will be I treated as wastes in the sewer treatment piant. CRITERIA REMARKS 1. Effectiveness I a) Sediment Poor; not proven to be effective. b) Nitrogen (N) Poor, not proven to be effective. c) Phosphorus (P) Poor, not proven to be effective. I d) Runoff No effect. 2. Capital Costs High, because it requires the purchase of equipment by community. I 3. Operation and Unknown but reasonable vehicular maintenance Maintenance would be expected. I 4. Longevity Poor, have to sweep frequently throughout the year. 5. Confidence Poor. 6. Adaptability To paved roads, might not be considered a worthwhile I expenditure of funds in communities less than 10,000. 7. Potential Treatment Unknown. I Side Effects 8. Concurrent Land Detention/Sedimentation basins. Management Practices I Source : USEPA, 1988. I I 1 I I I Best management practices (cont.) I Porous Pavement: Porous pavemenl is asphalt without fine filling particles on a grave) base. CRITERIA REMARKS I 1. Effectiveness a) Sediment Good. b) Nitrogen (N) Good. I c) Phosphorus (P) Good. d) Runoff Good to excellent. I 2. Capital Costs Moderate, slightly more expensive than conventional surfaces. 3. Operation and Potentially expensive, requires regular street main- I Maintenance tenance program and can be destroyed in freezing climates. 4. Longevity Good, with regular maintenance {i.e., street cleaning), I in southern climates. In cold climates, freezing and expansion can destroy. 5. Confidence Unknown. I 6. Adaptability Excellent. 7. Potential Treatments Groundwater contamination from infiltration of soluble I Side Effects pollutants. 8. Concurrent Land Runoff detention/retention. Management Practices I Flood Storage (Runoff Detention/Retention): Detention facilities treat or filter out pollutants or hold water until treated. Retention facilities provide no treatment. Examples I of detention/retention facilities include ponds, surface basins, underground tunnels, excess sewer storage and underwater flexible or collapsible holding tanks. I CRITERIA REMARKS 1. Effectiveness a) Sediment Poor to excellent, design dependent. I b) Nitrogen (N) Very poor to excellent, design dependent. c) Phosphorus (P) Very poor to excellent, design dependent, d) Runoff Poorto excellent, design dependent. . I i 2. Capital Costs Dependent on type and size. Range from S100 to $1,000, per acre served, depending on site. These costs include capital costs and operational costs. I 3. Operation and Annual cost per acre of urban area served has ranged Maintenance from S10 toS!25 depending on site. 4. Longevity Good to excellent, should last several years. I 5. Confidence Good, if properly designed. 6. Adaptability Excellent. I 7. Potential Treatment Groundwater contamination with retention basins. Side Effects I 8. Concurrent Land Porous pavements. Use Practices Source : USEPA, 1988. I I I Best Management Practices (Cont.) Sediment Traps: Seaiment traps are temporary structures made of sandbags, straw I bales, or stone. Their purpose is to detain runoff for short periods of time so heavy sediment particles will drop out. Typically, they are applied within and at the periphery of disturbed areas. I CRITERIA REMARKS 1. Effectiveness a) Sediment Good, coarse particles. I b) Nitrogen (N) Poor c) Phosphorus (P) Poor. I d) Runoff Fair 2. Capital Cost Low 3. Operation and Low, require occasional inspection and prompt I Maintenance maintenance. 4. Longevity Poortoccod. I 5. Confidence Poor. 6. Adaptability Excellent. I 7. PotentialTreatment None identified. Side Effects 8. Concurrent Land Agricultural, silviculture or other construction best I Management Practices management practices couid be incorporated depending on situation. I Surface Roughening: On construction sites, the surface of the exposed soil can be roughened with conventional construction equipment to decrease water runoff and slow I the downhill movement of water. Grooves are cut along the contour of a slope to spread runoff horizontally and increase the water infiltration rate. I CRITERIA REMARKS 1. Effectiveness a) Sediment Good. I b) Nitrogen (N) Unknown. c) Phosphorus (P) Unknown. d) Runoff Good. I 2. Capital Cost Low, but requires timing and coordination. 3. Operation and Low, temporary protective measure. I Maintenance 4. Longevity Short-term. I 5. Confidence Unknown. 6. Adaptability Excellent. 7. Potential Treatment None identified. I Side Effects 8. Concurrent Land Nonvegetative soil stabilization. I Management Practices I Source : USEPA, 1988. Best Management Practices (Cont.) I Riprap: A layer or loose rock or aggregate placed over a soil surface susceptible to erosion. I CRITERIA REMARKS 1. Effectiveness a) Sediment Good, based on visual observations. I b) Nitrogen (N) Unknown. c) Phosphorus (P) Unknown. d) Runoff Poor. I 2. Capital Cost Low to high, varies greatly. 3. Operation and Low. Maintenance I 4. Longevity Good, with proper rock size. 5. Confidence Poor to good. I 6. Adaptability Excellent. 7. Potential Treatment In streams, erosion may start in a new, I Side Effects unprotected place. 8. Concurrent Land Streamsitie (lake) management zone. Management Practices I Interception or Diversion Practices: Designed to protect bottom land from hillside I runoff, divert water from areal sources of poilution such as barnyards or to protect Structures from runoff. Diversion structures are represented by any modification of the Surface that intercepts or diverts runoff so that the distance of flow to a channel system is increased. I CRITERIA REMARKS 1. Effectiveness I a) Sediment Fair to good (30 to 60 percent reduction). b) Nitrogen (N) Fair to good (30 to 60 percent reduction). c) Phosphorus (P) Fair to good (30 to 60 percent reduction). I d) Runoff Poor, not designed to reduce runoff but divert runoff. 2. Capital Cost Moderate to high, may entail engineering design and structures. I 3. Operation and Fair to good. Maintenance I 4. Longevity Good. 5. Confidence Poor to good, largely unknown. I 6. Adaptability Excellent. 7. Potential Treatment None identified. Side Effects I 8. Concurrent Land Since the technique can be applied under multiple Management Practices situations (i.e., agriculture, silviculture, construction) appropriate best management practices associated I with individual situations should be applied. Source : USEPA, 1988. I I I I I Best management practices (cont.) Range and Pasture Management; The objective of range and pasture management is to prevent overgrazing because of too many animals in a given area. Management I practices include spreading water supplies, rotating animals between pastures, spreading mineral and feed supplements or allowing animals to graze oniy when a particular plant I food is growing rapidly. CRITERIA REMARKS 1. Effectiveness a) Sediment Good, prevents soil compaction which reduces infiltra I tion rates. b) Nitrogen (N) Unknown. c) Phosphorus (p) Unknown. I d) Runoff Good, maintains some cover which reduces runoff rates. I 2. Capital Costs Low, but may have to develop additional water sources. 3. Operation and Low. Maintenance I 4. Longevity Excellent. 5. Confidence Good to excellent. Farmer must have a knowledge of stocking rates, vegetation types, and vegetative I conditions. 6. Adaptability Excellent. I 7. Potential Treatment None identified. Side Effects 8. Concurrent Land Livestock exclusion, riparian zone management and I Management Practices crop rotation. I Source : USEPA, 1988. I I I I I I I Best management practices (Cont.) I Haul Roads and SkidTrails: This practice is implemented prior to logging operations. It involves the appropriate site selection and design of haul road and skid trails. Haul roads and skid trails should be located away from streams and lakes. Recommended guidelines for gradient, drainage, soil stabilization, and filter strips should be followed. I Routes should be situated across slopes rather than up or down slopes. If the natural drainage is disrupted, then artificial drainage should be provided. Logging operations should be restricted during adverse weather periods. Other goods practices include ground covers (rock or grass) closing roads when not in use, closing roadways during I wet periods, and returning main haul roads to prelogging conditions when togging ceases. CRITERIA REMARKS I 1. Effectiveness a) Sediment Good if grass cover is used on haul roads (45 percent reduction); Excellent if crushed rock is used as ground cover (92 percent reduction). I b) Nitrogen (N) Unknown. c) Phosphorus (P) Unknown. d) Runoff Unknown. I 2. Capita/ Cost High, grass cover plus fertilizer S5.37/100 ft roadbed, crushed rock (6 in} S179.01 /100 ft roadbed. I 3. Operation and High, particularly with grass which may have to be Maintenance replenished routinely and may not be effective on highly traveled roads. I 4. Longevity Unknown. 5. Confidence Good for ground cover, poor for nutrients. I 6. Adaptability Good. 7. PotentialTreatment Potential increase in nutrients to water course if Side Effects excess fertilizers are applied. I 8. Concurrent Land Maintain natural waterways. Management Practices I Source ; USEPA, 1988. I I I I I I I Best management practices (cant.) Contour Farming: A practice where the farmer plows across the slope of the land. This practice is applicable on farm (and with a 2-8 percent slope. CRITERIA REMARKS 1 Effectiveness a) Sediment Good on moderate slopes (2 to 8 percent sfopes), fair en steep slopes (50 percent reduction). b) Nitrogen (N) Unknown. c) Phosphorus (P) Fair. d) Runoff Fair to good, depends on storm intensity. 2. Capital Costs No special effect. 3. Operation and No special effect Maintenance 4. Longevity Poor, it must be practiced every time the field is plowed. 5. Confidence Poor, not enough information. 6. Adaptability Good, limited by soil, climate, and slope of land. May not work with large farming equipment on steep slopes. 7, Potential Treatment Side effects not identified. Side Effects 8. Concurrent Land Fertilizer management, integrated pesticide manage- Management Practices ment, possibly streamside management. Contour Stripcropping: This practice is similar to contour farming where the farmer plows across the slope of the land. The difference is that strips of close growing crops or meadow grasses are planted between strips of row crops like corn or soybeans. Whereas contour farming can be used on 2-8 percent slopes, contour Stripcropping can be used on 8-15 percent slopes. CRITERIA REMARKS 1. Effectiveness a) Sediment Good, 8 to 15 percent slopes, provides the benefits of contour plowing plus buffer strips. b) Nitrogen (N) Unknown, assumed to be fair to good. c) Phosphorus (P) Unknown, assumed to be fair to good. d) Runoff Good to excellent. 2. Capital Costs No special effect unless farmer cannot use the two crops. 3. Operation and No special effect. Maintenance 4. Longevity Poor, must be practiced year after year. 5. Confidence Poor, not enough information. 6. Adaptability Fair to good, may not work with large farming equip- ment on steep slopes. 7. Potential Treatment Side effects not identified. Side Effects 8. Concurrent Land Fertilizer management, integrated pesticide Management Practices management. • • • Source : USEPA, 1988. Best management practices {cont.} Crop Rotation: Where a planned sequence of crops are planted in the same area of I land. For example, plow based crops are followed by pasture crops sucn as grass or legumes in two to four year rotations. CRITERIA REMARKS I 1. Effectiveness a) Sediment Good when fieid is in grasses or legumes I b) Nitrogen (N) Fair to good. c) Phosphorus (P) Fair to good. d) Runoff Good when field is in grasses or legumes. I 2. Capital Costs High if farm economy reduced. Less of a problem with livestock which can use plants as food. 3. Operation and Moderate, increased labor requirements. May be off- I Maintenance set by lower nitrogen additions to the soil when corn is planted after legumes, and reduction in pesticide application. I 4. Longevity Good. 5. Confidence Fair to good. I 6. Adaptability Good, but some climatic restrictions. 7. Potential Treatment Reduction in possibility of groundwater contamination. Side Effects I 8. Concurrent Land Range and pasture management. Management Practices I Terraces: Terraces are used where contouring, contour strip cropping, or conservation tillage do not offer sufficient soil protection. Used in long slopes and slopes up to 12 I percent; terraces are small dams or a combination of small dams and ditches that reduce the slope by breaking it into lesser or near horizontal slopes. CRITERIA REMARKS I 1. Effectiveness a. Sediment Fair to good b. Nitrogen (N) Unknown. I c. Phosphorus (P) Unknown. d. Runoff Fair, more effective in reducing erosion than total run- off volume. I 2. Capital Cost High initial costs. 3. Operation and Periodic maintenance cost, but generally offset by I Maintenance increased income. 4. Longevity Good with proper maintenance. I 5. Confidence Good to excellent. 6. Adaptability Fair, limited to long slopes and slopes up to 12 percent. I 7. PotentialTreatment If improperly designed or used with poor cultural and Side Effect management practices, they may increase soil erosion. 8. Concurrent Land Fertilizer and pesticide management. Management Practices I Source : USEPA, 1988. I I I Best management practices (cont.) Animal Waste Management: A practice where animal wastes are temporarily held in waste storage structures until they can be utilizec or safely disposed. Storage units can be constructed of reinforced concrete or coated steel. Wastes are also stored in earthen 1 ponds. CRITERIA REMARKS I 1. Effectiveness a) Sediment Not applicable. b) Nitrogen (N) Good to excellent. I c) Phosphorus (P) Good to excellent. d) Runoff Not applicable. 2. Capital Costs High because of the necessity of construction and I disposal equipment. 3. Operation and Unknown, I Maintenance 4. Longevity Unknown. I 5. Confidence Fair to excellent if properly managed. 6. Adaptability Good. 7. Potential Treatment The use of earthen ponds can possibly lead to ground- I Side Effects water contamination. 8. Concurrent Land Fertilizer management. I Management Practices Nonvegetative Soil Stabilization: Examples of temporary soil stabilizers include I mulches, nettings, chemical binders, crushed stone, and blankets or mats from textile material. Permanent soil stabilizers include coarse rock, concrete, and asphalt. The purpose of soil stabilizers is to reduce erosion from construction sites. I CRITERIA REMARKS 1. Effectiveness I a) Sediment Excellent. b) Nitrogen (N) Poor. c) Phosphorus (P) Poor. I d) Runoffs Poor on steep slopes with straw mulch, otherwise good 2. Capital Costs Low to high, depending on technique applied. 3. Operation and Moderate. I Maintenance 4. Longevity Generally a temporary solution until a more perma- nent cover is developed. Excellent for permanent'soil I stabilizer. - - 5. Confidence Good. I 6. Adaptability Excellent. 7. PotentialTreatment No effect on soluble pollutants. I Side Effects 8. Concurrent Land Runoff detention/retention. Management Practices I Source : USEPA, 1988, I GLEAN LAKES SUBCOMMITTEE • GUIDELINES FOR i&TEEFHOUT Oft"N£HS MAINTENANCE OF SHORELINE . | Ponds over 10 acres in their "natural state" are defined under _ Massachusetts law as Great Ponds, The waters of Great Ponds belong to the • people of the Commonwealth under the colonial ordinances of the 1640*s and ™ so does the land under the pond in its natural state. The public interest in Great Ponds is expressed in the waterways program under General Laws I Chapter 91* This statute is administered by the Division of Waterways, I Division of Environmental Quality Engineering. The Groton Conservation Commission is the municipal body charged f with administering this state law as well as the Wetlands Protection Act (Chapter 131> s. 40). Any work in wetlands adjacent to a pond or in it, — requires that the Conservation Commission be notified. I Examples of work' requiring the filing of a Notice of Intent with the state, through the Conservation Commission are: • • 1) Any structure in or within 100 ft. of a water body or wetland — - * "building or extending a wharf, pier, dam, well, road, bridge or other structure, or to drive piles, fill land, or excavate in or I over the waters of any Great Pond below natural high water mark, I or at or upon any outlet thereof..." (G.L. Ch. 91, Sec. 13 & 19) 2) Any other work requiring use of heavy equipment (tractors, " I bulldozers, bsckhoes, etc.); construction and maintenance where • there is potential for runoff or sedimentation into wetlands or water body. • Routine maintenance of shoreline includes the planting of bushes, raking and seeding, and does not require notifying the Conservation Commis- _ sion. No addition of sand to the waterfront, even small amounts, should be • made without first notifying the Conservation Commission. Long term maintenance of beaches will be addressed by the Diagnostic/Feasibility Study. - • BUILDINGS, ROADS & DRIVES . • Good planning and common sense construction will keep new buildings from disturbing natural scenery. Place new buildings well back from shorelines. I Plant shrubs and grass along borders of roads. . The root systems of trees and shrubs sbsorb water that would otherwise run onto pavement. • Hoads can become slippery and dangerous when wet; play areas can become I unusable. Avoid constructing roads or driveways that go directly downhill ~ I and toward the water. Curve and angle the road so that runoff will be ' * diverted before reaching the water. ~ • - - ;- - _..-..- Where there are steep banks, preserving the natural groundcover | is often more attractive^ often trouble-free and often more dependable than complicated and costly engineered projects. - ' - • _ i I GUIDELINES FOR ViATSRFRONT OWNERS -2- I MOTOR BOATS Keep boat engines well tuned. Gasoline spills evaporate but the oil in the mixture remains and can kill small animals and plants, reduce I dissolved oxygen in the water needed for fish life, and may introduce toxic lead compounds into plants and fish. In large amounts, the fuel can also create a health hazard for swimmers and contaminate drinking vater. I » SEPTIC SYSTEMS I Boards of health, plumbers and septic system servicers advise that septic tank? be checked and cleaned every 2 or 3 years. If soil absorbs too quickly, leachate passed through reaches the lake before being treated. If a leach bed is saturated, the ground above may puddle and the discharge I is no longer being pruified, although it may not necessarily back up. A simple "dye test" can be conducted to determine whether a system I is operating improperly end leaking sewage into the lake. Dye tablets are inexpensive and can be purchased from plumbing and supply stores. To per- form the test, put about five tablets in the toilet and flush. If the I toilet and the washing '.machine are connected to different systems, they should be tested separately. If sewage is being discharged directly into the lake, the dye will appear in the water immediately. Otherwise, the area around the septic system should be checked every day for about two weeks. I If the dye appears on the surface of the ground or in the water, the sewage disposal system is not operating properly. I Avoid phosphate detergents. The major portion of phosphates in sewage comes from household detergents, and the average person con-teributes 4 pounds of phosphorus (about 12 pounds of phosphate) into waste water each year. Phosphorus can generate 500 times its own weight in algae and other I .plants in a lake. The function^ of phosphates in laundry and dishwashing detergents I is to replace hand rubbing. This function can be accomplished by using soap plus washing soda (a water softener that removes calcium scum) and it is still an effective comgination for cleaning fabrics made of natural fibers. I If you switch from detergents to soap and washing soda, white clothes may yellow unless all detergent residue is removed. This is done by soaking in hot water containing 4 tablespoons of washing soda before first washing. I Automatic dishwasher detergents are particularly high in phosphate content. A mixture of washing soda with dishwater detergent is an effective I cleaning agent and works well in automatic dishwashers. I I MAY I I I PRESSURE TREATED LUMBER • Summary - June 1988 • I The increase in construction of waterfront retaining walls and docks using pressure treated lumber requires • updated information on its safety. The new Massachusetts | Audubon Helpline in Lincoln (1-800-541-3443) and to the MACC were productive. • Goggles and masks should be worn when working with p.t.l. It does not leach into fresh water in any significant amount. Contact with salt water causes leaching • and is not allowed in coastal waters. The Dept. of Public H Health is involved in the workers' "Right to Know" issue, but does not consider it a hazard beyond that, and there is • no current legislation governing its use in fresh water. It | is advisable, however to finish decks with two coats of polyurethane, particularly where there are children who play • on a surface and could rub or pick up splinters. • The commonly available treated lumber is labeled "Wolmanized" and is considered the safest to use. i An interesting note from Robert Margolius: Experimental work is being done with soaking lumber briefly • in boron, which permeates the wood completely (rather than | leaving the core still vulnerable to rot). It prevents insect and mildew damage by inhibiting insect digestion, _ causing starvation or suffication. This could be coming on I th1~hoe markem a y t o t+• in a= ffe auw mni-i-t-hmonthso . ^H I M. Eger I I I I I I I APPENDIX B. Environmental Notification Form. I ENVIRONMENTAL NOTIFICATION FORM I I 1. SUMMARY A. Project Identification 1. Project Name I Address/Location _ City/Town I 2. Project Proponent Address 3. Est. Commencement . Est. Completion Approx. Cost S . Status of Project Design Complete. I 4. Amount (if any) of bordering vegetated wetlands, salt marsh, or tidelands to be dredged, filled, removed, or altered (other than by receipt of runoff) as a result of the project. acres square feet. I 5. This project is categorically included and therefore requires preparation of an E3R Yes No ? B. Narrative Project Description '. I Describe project and site. I I I I I I I I Copies of the complete ENF may be obtained from (proponent or agent): Name: Firm/Agency: —, I Address: . Phone No '. 1986 THIS IS AN IMPORTANT NOTICE. COMMENT PERIOD IS LIMITED. I For Information, call (617) 727-5830 I P.2 C. List the State or Federal agencies from which permits or other actions have been/Wili be sought: I Agency Name Permit Date filed; Hie no. B I I D. Use any government agencies or programs from which the proponent will seek financial assistance for this project: • Agency Name Funding Amount | I I E. Areas of potential impact (compfete Sections It and III first, before completing this section). 1. Check all areas in which, in the proponent's judgment, an impact of this project may occur. Positive • impacts, as well as adverse impacts, may be indicated. . I Construction Long Term Impacts Impacts • Inland Wetlands ...... _— ______™ Coastal Wetlands/Beaches ...... ___ '> _ Tidelands...... _ !_.... _ H Traffic...... _ _ I Open Space/Recreation...... - - _ _ . _ Historical/Archaeological ...... - — -- _ _ mm Fisheries/Wildlife...... "...... _ _ • Vegetation/Trees...... -- - _ Agricultural Lands ...... _ - -- _ Water Pollution...... _ - _ _ * Water Supply/Use ...... ___ __ . _ I Solid Waste...... _ _ _ _ _ .. . Hazardous Materials ..... - ...... _ — -- _ Air Pollution ...... - ...... _ _ _ _ Noise ...... r ...... _ _ I Wind/Shadow...... " ...... , ...... _ ' _ Aesthetics ...... _ _ - - Growth Impacts ...... - - _ , - I Community/Housing and the Built Environment...... - - -- • . . -- Other (Sppcify) __ . -- . - . ---- . -- . - I 2. List the alternatives which have been considered. I I I I I P.3 I F. Has this project been filed with EOEA before? No Yes EOEA No. I G. WETLANDS AND WATERWAYS I 1. Will an Order of Conditions under the Wetlands Protection Act (c.131s.40) or a License ur.de'. the Waterways Act (c.9l) be required? Yes No 2. Has a local Order of Conditions been: I a. issued? Date of issuance ; DEQE File No. b. appealed? Yes ; No „ . 3. . Will 2 variance from the Wetlands or Waterways Regulations be required? Yes ; I No I II. PROJECT DESCRIPTION A. Map; site plan. Include an original 8Vz x 11 inch or larger section of the most recec: C-S.G.5. I 7.5 minute series scale topographic map with the project area location and boundaries c:e-2.-:> I shown. If available, attach a site plan of the proposed project. B. State total area of project: acres. Estimate the number of acres (to the nearest 1/10 acre) directly affected that are cur I 1. Developed ...... _ acres 6. Tidelands ...... acres 2. Open Space/ 7. Productive Resources Woodlands/Recreation _ acres Agriculture ...... acres I 3. Wetlands ...... _ . acres Forestry ...... acre* 4. Floodplain ...... _ . acres S. Other ...... acres I 5. Coastal Area ...... _ acres C. Provide the following dimensions, if applicable: I Existing Increase To:a: Length in miles Number of Housing Units I ' Number of Stories ../ " Gross Floor Area in square feet Number of parking spaces Total of Daily vehicle trips to and from site I (Total Trip Ends) Estimated Average Daily Traffic on road(s) serving site I 2. I 3 D, TRAFFIC PLAN. If the proposed project will require any permit for access to locaJ rc»ds or I state highways, attach a sketch showing the location and layout of the proposed P.4 III. ASSESSMENT OF POTENTIAL ADVERSE ENVIRONMENTAL IMPACTS Instructions: Explain direct and indirect adverse impacts, including thos« arising from general construction and operations. For every answer explain why significant adverse Impact is considered likely or unlikely to result. Positive impact may also be listed and explained. Also, state the source of information or oiher basis for the answers supplied. Such environmental information should be acquired at least in part by field inspection. A. Open Space and Recreation 1, Might the project affect the condition, use, or access to any open space and or recreation area? Explanation and Source: 2. Is the project site within 500 feet of any public open space, recreation, or conservation Ur.d? Explanation and Source: B. Historic and Archaeological Resources 1. Might any sire or structure of historic significance be affcctec bu the project? (Prior consultation with Massachusetts Historical Commission is advised.) Explanation and Source: 2, Might any archaeological site be affected by the project? (Prior consultation w-t'th Massachusetts Historical Commission is advised.) . « E.rp/anarion and Source: | I C. Ecological Effects . 1. Might the project significantly affect fisheries or wildlife, especiauv any rare or endangered • species? (Prior consultation with the Massachusetts Natural Heritage Program is advised). • Explanation and Source: I I I — I I P.5 2. Might the project significantly affect vegetation, especially any rare or endangered species I of plant? {Prior consultation with the Massachusetts Natural Heritage Program is advised.) (Estimate approximate number of mature trees to be removed: ) I Explanation and Source: I I 3. Agricultural Land. Has any portion of the site been in agricultural use uiihin the last 15 years? If yes, specify use and acreage. I Explanation and Source: I I D. Water Quality and Quantity 1. Might the project result in significant changes in drainage patterns? I Explanation and Source: I I 2. Might the project result in the introduction of any pollutants, including sediments, into marine waters, surface fresh waters or ground water? I Explanation and Source: I I 3. Does the project involve any dredging? No Yes Volume . If 10,000 cy or more, attach completed Standard Application Form for Water Quality Certification, I Part I (314 CMR 9.02(3), 9.90, DEQE Division of Water Pollution Control). I I I I P.6 4. Will any part of the project be located in flowed or filled tidelands. Great Ponds, or other waterways? (Prior consultation with the DEQE and CZM is advised.) Exp/onaff'on and Source; 5. Will the project generate or convey sanitary sewage? No Yes If Yes, Quantity: gallons per day Disposal by: (a) Onsite septic systems Yes No . • (b) Public sewerage systems (location; average and peak daily flows to | treatment works) Yes No Explanation and Source: • I 6. Might the project result in an increase in paved'or impervious surface over a sole source • aquifer or.an aquifer recognized as an important present or future source of water supply? Explanation and Source: m I 7. Is the project in the watershed of any surface water body used as a drinking water supply? • Explanation ancf Source: I I 8. Are there any public or private drinking water wells within a I/2-mile radius of the proposed M project? • • Explanation and Source; I I I I I I p.: I 9. Docs the operation of the project result in any increased consumption of water? Approximate consumption gallons per day. Likely water source(s) _ I Explanation and Source: I I E. Solid Waste and Hazardous Materials I. Estimate types and approximate amounts of waste materials generated, e.g., industrial, domestic, hospital, sewage sludge, construction debris from demolished structures. How/ I where will such waste be disposed of? I Exp/onoffon and Source: I 2. Might the project involve the generation, use, transportation, storage, release, or disposal I of potentially hazardous materials? I £xp/ona*fon ancf Source: 1 3. Has the site previously been used for the use, generation, transportation, storage, release, I or disposal of potentially hazardous materials? I Explanation and Source: I F. Energy Use and Air Quality I 1. Will space heating be provided for the project? If so, describe the type, energy source, and approximate energy consumption. I Explanation and Source: I I I P.S I 2. Will the project require process heat or steam? I( so, describe the proposed system, the fuel — type, and approximate fuel usage. I Exp/anation and Source: I I 3. Does the project include industrial processes that will release air contaminants to the M atmosphere? If so, describe the process (type, material released, and quantity released). • Explanation and Source; I I 4. Are there any other sources of air contamination associated with the project (e.g. automobue M traffic, aircraft traffic, volatile organic compound storage, construction dust}? • Explanation ana'Source: I I .,Are there any sensitive receptors (e.g. hospitals, schools, residential areas) which would t>€ M affected by air contamination caused by the project? • Explanation and Source: I I G. Noisrvoisee • im 1. Might the project result in the generation of noise? • (Include any source of noise during construction or operation, e.g., engine exhaust, p!^e driving, traffic.) > mm Explanation and Source: I I I I I P.9 I 2. Are there any sensitive receptors (e.g., hospitals, schools, residential areas) which would a/fecied by any noise caused by the project? I Explanation and Source: I I 3. Is the project a sensitive receptor, sited in an area of significant ambient noise? I Explanation and Source: I H. Wind and Shadow I 1. Might the project cause wind and shadow impacts on adjacent properties? I Explanation and Source: I • I. Aesthetics ™ I. Are there any proposed structures which might be considered incompatible with existing, adjacent structures in the vicinity in terms of size, physical proportion and scale, or significant differences in land use? I Explanation and Source: I I 2, Might the project impair visual access to waterfront or other scenic areas? I Explanation and Source: I I I I P.IO I IV. CONSISTENCY WITH PRESENT PLANNING I Discuss consistency with current federal, state and local land use, transportation, open space. recreation and environmental plans and policies. Consult with local or regional planning authorities where appropriate. I I I I I I V. FINDINGS AND CERTIFICATION I A. The public notice of environmental review has been/will be published in the foilow-in newspaper(s): I - Date Signature of Responsible Officer Date Signature of person preparing ENF (if different from above) I or Project Proponent Name (print or type? Name (print or type) I I Number Telephone Number I I I I I I I I I APPENDIX C. . Comments by Interested Parties and * Sample Survey Questionnaire. I I I I I I I I I I I I I IMPORTANT NOTICE FOR I HOMEOWNERS . AND ALL USERS • OF LOST LAKE/KNOPPS POND I I A Public Meeting will be held on Wednesday, 1 November 18, 1987 at 7:30 p.m. in the • Groton-Dunstable Secondary School Library. At this meeting, Baystate Environmental Consultants will • describe the Lost Lake/Knopps Pond Diagnostic Study. They will illustrate studies done to date • and discuss their significance. m Baystate will be interested in obtaining observations and additional information from the I audience, and will answer questions. This meeting is for all interested in the lake — homeowners and | all users. _ Please attend. i I Groton-Dunstable Secondary School Library I Wednesday, November 18,1987 7:30 p.m. i I TOWN OF GROTON I P. O. Box 669 GROTON. MASSACHUSETTS 01450 I OFFICE OF THE CONSERVATION COMMISSION I FIRST PUBLIC INFORMATIONAL MEETING DAVID MITCHELL, PhD, BAYSTATE ENVIRONMENTAL CONSULTANTS • LOST LAKE/KNOPPS POND, GROTON, MA - NOVEMBER 18, 1987 • The meeting was held in the Groton-Dunstable I Secondary School Library at 7:30 p.m. Dr. Mitchell distributed questionnaires to the attendees, the majority of _ whom were lakefront and watershed residents. Estimated • attendance was about 50 people. Clean Lakes Committee * members present were: Marjorie Eger, Berta Erickson, Edmund Guerard, Jerome Lapham and Kenn Thompson. Mrs. Eger I introduced Dr. Mitchell who gave a progress report on I studies made to date, and illustrated with slides which included areas of Lost Lake/Knopps Pond. • The tenor of the questions during the subsequent question/discussion period was largely concern about the prognosis for well-being of the lake. Following are 8 questions brought upduring this period: • Are there more springs in Knopps Pond than Lost Lake? • What would be the effect of a drawdown on Duck Pond? | (Change in groundwater level in the area). How far would water drop? (Impact of drawdown depends on « land contour.) I Nutrient value of acid precipitation? (Still plenty of alkalinity but this lake does have tendency toward acidity. Snow does have acid but lake gets chemicals I that leaves supply. Nitrate levels are not too high I in Lost Lake.) Doesn't low level of lake in early spring encourage weed • growth? (Lost Lake is not deep; it would requirean • increase of 5 feet to make a difference which would be minimal partly because growth is occurring even _ during the winter season. There are plants growing I on the. lake bottom in all but two locations -- the • deep hole in the Redwater area of Knopps Pond and in the channels. ' • Can you give some estimate of percentages where the | problems originate? (There still needs to be much more data.) (Plants can affect water positively -- • water must pass through the grass carpet which I filters it. Surface inputs are more important than groundwater inputs.) i I Baystate Dx Study Public Meeting I Nov. 18, 1987 — 7 — I If sewering were installed in the Lost Lake area, what would then become of the the lake? (Chemicals would be reduced. While Knopps Pond water is all right, the I chemicals are increasing. In the fifties the lake was cleared of weeds and trash fish with rotenone which suffocates fish.) The most major step, drawdown of the lake, is to eliminate I weeds? (Without knowing about its sediment, it is not the best solution. Drawdown is effective but is not cost effective.) I Will the sediment be analyzed? (Don't know yet.) Is the hydroraked material valuable? (It can be good compost.) I Can this compost be used for reclaiming a gravel pit? (It is good but transportation costs are high, so it can be worthwhile only when the project is close by. How can one control valisneria? (Harvesting is not an I effective method. Harvesting gives good results for water chestnuts but we don' t have them here. } Questions were asked about the natural evolution of a lake I [eutrophication], and answered by Dr. Mitchell. What might be the expected future of the life of the lake if nothing were done to it? (It has a relatively small I watershed without a serious threat of pollution to it. ) Phosphorus seems to be the main problem. (True, and this is readily controllable) I There are two major housing developments within the watershed; what would be their impact after construction is completed in about ten years? (The I projected uses of the land can justify certain zoning restrictions.) In answer to further questions about drawdown, Dr. Mitchell spoke of turnover time of a lake determining its I effectiveness; that the effect has to go down 4-5 feet, where the problem plants are, a drawdown depth which would affect most homes. Some intermittent I wells are to be tested to get an idea of the sources of groundwater. Drawdown would affect some plants more than others; it is not as useful with seed I plants. Which dominant plants would be affected by drawdown? (Milfoil, pond lily.) One resident expressed concern that state funded assistance I can mean great loss of local control but was I reassured by Dr. Mitchell that this is not so. I I I Baystate Dx Study Public Meeting • Nov. 18, 1987 I -3- Motorboat use -- does it have negative or positive effect? • (It depends on the type of plant; some plants are "scoured" away while others are chopped and scattered so growth is increased. In either case the effect is I fairly local.) • As for regulation of boating, Dr. Mitchell reminded people that it is a matter for local option and local • regulation. Different communities have their own | sets of rules depending on the major uses and preferences of residents. To earn state funding for « lake improvement, the greater the public use of a • lake, the more eligible the lake becomes for such funds. The existence of a new town well down stream, however, would not be likely to add to its point • earnings. Baystate has had much experience in locating funds for implementation and would be able to advise Groton if it decides to proceed to Phase II implementation. i At the conclusion of the meeting, lake resident Brett Stevens expressed much interest in the meeting and suggested • sending questionnaires to out of town seasonal residents as * well as notifying these residents of the next public meeting. Lakefront property owner and Laurel Cove resident I Kenneth Moody took a supply of questionnaires to distribute m among his neighbors. Charles Backus of Spruce Road, Lost Lake, expressed his interest intakinganactive part in • lake and conservation issues if there were a way of using • his service in the little time he has available working long hours six days a week. _ The meeting concluded at 9:30 p.m. I Marjorie Eger, Chmn. Clean Lakes Committee I I I I I I I CLEAN LAKES COMMITTEE I BAYSTATS ENVIRONMENTAL CONSULTANTS LOST LAKE/KNOPPS POND DIAGNOSTIC STUDY I SECOND PUBLIC MEETING, JULY 20, 1988, 7:30 P.M. I MINUTES Mrs. MarDorie Eger introduced Baystate Environmental - Consultants' Project Director David P. Mitchell, Ph.D., who I reported on the work performed thus far. Dr. Mitchell described some of procedures: Water analysis. I Seepage meters installed and monitored to determine water balance throughout the seasons. Sampling to determine quality of water. Sampling of sediment and for quality of the muck; I Measuring stratification of lake water; Plant count: species; analysis for heavy metals; biology(major food levels of the lake, beginning I with algae and animals feeding on algae and progressing to the larger aquatic life; Macrophytes (rooted aquatic plants above and below I the surface or Lost Lake/Knopps Pond. To carry out some of these procedures required: Snorkeling I Making transects -- mapping a grid of squares over the lake to insure total coverage; Researching old records to develop a history of fish in I the lake,-including judicious sampling of old fishing tales; I Talking with residents. Dr. Mitchell went on to share some statistics and general information at this point in the study, which has still the fall season before the study procedures are completed and I an analysis and final recommendations are made. His presentation included slides to illustrate techniques and procedures used. Then he showed slides of Lost Lake/Knopps I Pond, to illustrate its varied shoreline, the work currently being done and the conditions requiring improvement. Lost Lake/Knopps Pond has its greatest depth of 30-32 I feet in the Redwater section ands a general depth, of about 16 to 17 feet. Lost Lake was created in the late 1800's from the former Cow Pond Meadow and is more shallow, its deepest hole being off Rocky's Point. Martin's Pond brook is the major I tributary entering Lost Lake, and the swamp at its entrance is an effective wetland. An unnamed brook enters at its southern end. It flows from October to the spring and is dry during the I summer, The brown color of its water is not an indicator of pollution or of especially poor quality but of the loose vegetation carried in it. He noted that overall there is a I healthy population of a variety of fish. I I BAYSTATE ENVIRONMENTAL CONSULTANTS PUBLIC MEETING • JULY 20, 1288 I -2- Knopps Pond is the original natural water body and I receives its fresh water more from groundwater seepage and has • more groundwater flow. (The north end of Lost Lake is the area receiving least groundwater flow or seepage.) • Dr . Mitchell received questions from the audience: Where are the stagnation spots? [There are two kinds of « stagnation — (1) water not being pushed by incoming • water, and (2) water not subject to wave or wind action. This is an intricate lake and does not easily flush. Dr. Mitchell noted that Lost Lake has more • surface water tributaries and Knopps Pond has more m groundwater; they function like two different lakes.] Where are the springs throughout the lake? [In Springy • Pond, of course. But the cold.spots that one feels U while swimming are mostly because there is a thermal layering of the water and one is feeling the colder ^ bottom layer as it moves. There are not underwater • fountain type springs that could be mapped.] Dr. Mitchell described the reason for the dense macrophytes being uniform throughout the entire section of Lost Lake • was because of the lake's frying pan configuration. I Weed control is difficult because the whole lake area receives growth encouraging sunlight. Myriophyllum • (parrot feather) is the most troublesome to get rid of. • Does gasoline from motor boats affect wells? Some swimmers are aware of it floating on the surface and smell and _ even taste it. [This is a Board of Health concern but • it is a surface phenomenon and does not permeate the • lake or go into wells. Testing for hydrocarbons, as one person inquired about, is expensive and not generally • done, but Dr. Mitchell's informal opinion wasthatit | would not show up in well water tests.] FEASIBLE ALTERNATIVES IDENTIFIED: (Restoration techniques) I Drawdown. . A moderate drawdown would provide small exposure to lake bottom because much of the lake has steep sides. Prevention of nutrients from entering the lake (Aluminum • Suphate application). A member of the audience noted I the medical use of aluminum sulphate in treatment of arthritis, but Dr. Mitchell said that it can kill fish • with too heavy an application. It is generally applied gj as a one-shot binding process, not a continuing dosage as for arthritis.. _ i I i I BAYSTATS ENVIRONMENTAL CONSULTANTS PUBLIC MEETING I JULY 20, 1S83 -3- Careful land management in the watershed by preventing heavy I development in critical resource areas through Town bylaws and through Conservation Commission education of the public. Land usage in the watershed at this point I still is considered to classify has having moderate - residential development, where controls on future development can be effective. Member Larry Swezey of I the Grotdn Board of Health commented that the BOH has already doubled the state mandated limits for water and sewer setbacks and that there needs to be much more hard information to make a case for extending these limits I any further. Sewering. Without sewers, density has great influence on groundwater limits. In long term planning, the best I benefits would be gained from eventual sewering of the lake, area. Overall water quality now is good but is I tending toward mediocre. Dr. Mitchell said that the final report from the study will be sent to the town early in 1389, and will describe various restoration procedures. There are state funds I providing generally 75% of the cost of Phase II Implementation projects, such as modi fied drawdown. To carry out any plans requires efforts to raise townwide awareness of the importance I of lake use for everyone, ability to prioritize possibilities and support from town and state officials. It averages seven years from application through to completion before eventual I results. Dr. Mitchell's information generated another hour of I lively questioning which included the following concerns: Does a driven shallow well draw water from the lake? [Water flows toward the lake, so the well mostly would be I drawing on groundwater, although the ground below a shallow well could draw back lake water occasionally.] What is the rate and amount of water loss from the lake through evaporation? [Approximately half of the I rainfall entering the lake goes out again through evaporation and wind and wave action. It is the aim of this study to determine the lake's hydrologic budget and I the nutrient budget.] What causes the significant turbidity of the water, as noted this season? [.It is cloudiness of the water due to I algae as well as particles of sediment, coming after a rainstorm and recreational activity on the lake, I especially notable after weekends. I I JULY 20, 19 S3 g I Can there be any limitation on rate of boat use, since the lake has a state boat launch? fit is legal for the £own to • pass bylaws, and advisory signs may be placed at access • points. K_ Is it currently possible to lower the dam further? [It c'puld • be lowered two to three feet more but would not provide | significant relief because the vegetation would still be beyond the lowered shoreline. i}_ « What can homeowners do themselves for waterfront cleanup? - *'•> • [Raking Is useful where there is a gravel shore bottom ™ but it is not possible with loose, mucky bottom. It also depends on the plant whether hand raking is I effective — feathery milfoil being difficult.] I Is rock salt effective on milfoil? [It would make the lake salty before reaching the plants. The reason is similar • to why herabicides should not be used. Results are | quick but the nutrients released cancel their value and there are problems with residuals.] _ How much does acid rain affect the lake? [All rain now is • acidj. but the effect is not significant. Most lakes in . ™ this area are in fair condition, with an average DH of 6.3 to 6.7. " • Are the products of dredging useful? [The quality of the • residuals is a question. With hydraulic (suction) dredging, the material has to settle in a basin and is • too difficult to manage in large quantities. Dry I dredging requires the complete dredging of a drained lake or it is not cost effective.] Some membersofthe _ audience either experienced or familiar with this work, • believe it to be a reasonable choice because of the • rising value of the dredged material and the effectiveness of the results. • If dredging is feasible, what road blocks might be | encountered? [If the monetary obstacles can be overcome — and these include the costs related to analysis of g the sediments for chemicals and heavy metals — the • considerations are for location of wetlands and how much of the residuals consist of peat, which is not clean fill. . • Why is.there so much phosphorus coming from Martins Pond • Brook? [Probably from accumulation of things because it passes through more land and more varied land uses. . • I i i i i I I BAYSTATE ENVIRONMENTAL CONSULTANTS PU3IC MEETING . JULY 20, 1983 -5- I Among the significant elements entering the lake, phosphorus is of the greatest concern and can enter through tributaries. Point source discharges (i.e. street drains) or withdrawals I (i.e. town wells) would not apply for this lake. Chemical concentrations should be measured and can include what conies' in from septic systems, dust falling on the lake, waterfowl droppings, and their changes over the year. These all provide I the information for the resulting phosphorus budget. It is difficult to remove all the weed vegetation. Lost Lake would require expensive heavy dredging because sunlight reaches all I parts. It is more reasonable to try to reduce chemicals which may settle in the lake bottom. I There was considerable discussion about the effect of gasoline motors on the water. Consensus settled on some kind of regulation such as alternate days for the lake uses which may be incompatible, and for boating education, which has been I already initiated by the recently formed Groton Lakes Association by placement of some advisory signs on Lost Lake/Knopps Pond and with distribution of copies of state I boating regulations. This is more a political issue involving recreational choices and quality of life than a major issue in the diagnostic study, and Dr. Mitchell advised getting together I a committee of people representing all the lake use interests, to prioritize their recommendations and bring them to Town Meeting. I The attendance- list was 56, and an estimated ten persons more may have been present. A number of watershed residents filled out questionnaires about their household water uses and I lake recreational preferences, which will greatly assist Baystate in making the best recommendations possible for protection of lake quality. Completed questionnaires may also I be passed in later to any Clean Lakes Committee member or to the Conservation Commission office. I The meeting concluded at 10 p.m. I Respectfully submitted, I Mar jor'ie Eger, Chmn I I I I I I I I I Homeowners all users I of Lost La s Pond I I I A Public Meeting will be held on Uednesday, March 8th, 1983 at I 7:00 PM in the Groton-Dunstable Secondary School Library. The topic will be the results and recommendations stemming from the year-long study of Lost Lake/Kncpps Pond. Questionnaires regarding your recreational and household water usage will be available at the I meeting. This information, as well as your input and concerns will be included in the final recommendations. I Please plan to attend I I I I I I I PUBLIC MEETING I MARCH 8, 1989 I BAYSTATE ENVIRONMENTAL CONSULTANTS DIAGNOSTIC: STUDY The meeting convened at 7:00 p.m. in the Groton— Dunstable Secondary School Library. Clean Lakes Committee I Chairman Marjorie Eger introduced David Mitchell, Ph.D. of Bay state Environmental Consultants who described the work per formed over the four-season study of Lost Lake/Knopps Pond, I Accompanying Dr. Mitchel1 were EEC colleagues Kenneth Wagner and William McQonfcgle. Present also were DEQE Clean Lakes Program Project Director Steven Nathan, and Clean Lakes Committee members Jerome Lapham, Phi lip Trudeau, Dorothy I Woodle, Nancy Woodle and non-member attendees Deborah ?< Thomas Doyle. PRESENTATION I In describing the many causes for excessive weed growth in lakes, Dr. Mitchel1 pointed out the high proportion of phosphorus in the water coming from household uses such as I laundry and lawn fertilizer. But some comes from dust in the air and bird droppings, over which we have no control. Sedimentation fosters macrophytes, which are rooted flowering plants which in their turn restore sediments. I Reducing macrophyte density allows smal1er fish to be eaten more easiy by bigger fish, so that the si^e and number of game fish increase. I Integral to the lake is land use within the watershed. The Lost Lake/Knopps Pond watershed is 50/. forested, 25"/. residential , 15"/. agricultural , with the remainder open land, wetlands and recreational. The sur face watershed and I groundwater watershed areas for our lake fall within generally similar boundaries. Some groundwater moves toward Carmichael Swamp. Mar tins Pond Br ook pr ovi des SO"/, of the wat er feed i ng I into the lake. Dr. Mitchel1 1isted some of the remedial choices, such as hypolimnitic aeration or hypolimnitic withdrawal. I While Bay state does dredging, this lake is not considered a good candidate because of deep muck further out from shore — deeper than 10 feet. To remove bottom material might cost $7-8 million, and cost ratio to water quality I improvement is small. Drawdown would make accessible much bottom land; in many parts the lake depth is 5-7 feet. Some plants do not I respond wel 1 to drawdown but water level control merits serious consideration. At present there is about a 2 foot I change in water level from summer to winter. I I I I Clean Lakes Committee F'ubl i c Meeting March 3, 1989 • There are three ways to draw down: 1. Use gravity to draw down five or more feet • 2. Pond drain. This means essent iallyapluginthe | bottom, which for Lost Lake/Knopps Pond would mean an outlet placed through the dam structure. _ 3. Temporary siphon. This would mean water being sent over • the dam. ' * 557. of the entire sur f ac e ar ea woul d be dr awn down. Th i s is an inexpensive way to remove macrophytes and provides for I owner maintenance. I Bot t om bar r i er, sue h as aquasc r een, c an be i nst «11ed in speci fie water front areas for swimming or access to moorings. • Dr. Mitchel1 suggests that its purchase for Sargisson Beach • and probably Baby Beach, would be fundable by the state. Then, purchasing a bulk amount enough for property owners would enable them to purchase the material at the favorable • bulk price for their waterfronts. ™ Changeover of dam ownership could be part of a Phase II project. • Dr. Mitchell reviewed the town's position: | ** • The town has good groundwater control through bylaws, aquifer protection districts and conservancy areas. Aquifer » districts 1 and 2 provide good recharge but not enough for • ful1 protection of the water supply. Mitchel1 suggested the town can require that any new development maintain the drinkable quality of its water through monitoring welIs • located at property borders. Cars in the use of ferti1izers, • phosphorus and erosion control should be required both in agriculture and individual property maintenance. Land . • development should follow best management practices for runoff • from road surface and be made to maintain water quality. Dumping in kettle holes and into Knopps Pond, for example _ should be di sal 1 owed. • ** The recommended average septic tank pumping rate is ™ three years, but lakeside duel lings should do it every year. This can be promoted by offering a tax abatement with proof of tt pumping. There can be a ban on phosphorus, as in New York | State, One third of the phosporus in lake groundwater comes from household maintenance. « ** Redesign of dam and temporary siphon, at a cost of • approximately $76,000. ** Pond drain with one internal valve — a £180,000 expense, which with a state grant, would be a $'SO,000 expense • to the town. The town would then be responsible for • monitoring the valve throughout the seasons. Best next step - temporary drain, siphoning, town to pump out water gradually • so as to observe impact on wells cind weeds. • ** Education program - signs at beaches (i.e., change oil before, not at water front. > Rivers S< Harbors Act deals with m dams, but it has no money and there is a 2—3 year wait for • money under the state Clean Lakes Program. ™ I I I Clean Lakes Commi ttee Publi c Meet i ng March S, 13S9 I '-i o ** BRIEFLY — To c ommen ce r emed i a1 measur es as quic k1y as I possible,try to doo it on the local level. At an approximate $16,000 c ost over all: 1. Temporary siphon I 2. Bottom barriers 3. Education I DISCUSSION Bob Lewi s, a resident of Flavel 1 Road and member of the Piann i ng Board, feels that bot h his wel 1 and sept i c syst em have been affected by loss of water storage in the area of Cow I Pond Brook from back fi1 ling during development around Lowel1 Road, Lost Lake, and the two board system of lake level control. He beli eved that a 5 foot drawdown represented a I great amount of water and would require extreme caution in executing. Richard McLaughlin has 1ived near the dam and believes I the area can take this drawdown. Dr. Mitchell pointed out that timing of the drawdown would be at the season of lowest ground water, along with bleeding off the water gradually. Below the outlet is 1 sufficient capacity to allow passage of water over si x weeks, &t a volume no greater than already occurs at spring. It shoul d not a f f ec t Ulh i t ney Pond. But he did c aut i on t hat I mai ntai ni ng the water quali ty of Whi tney Pond was another compelling reason not to consider chemical methods of weed control on this LL/KF. I Lakefront resident Mrs. Alberta Dearborn wondered how the weeds would actually become reduced if they continually die down and restore the nutrient supply. Lost Lake resident Alex Woodle restated the question asking that by limiting the I Amount of phosphorus coming into the lake, how long could it work. Martins Fond Brook, with its extensive area of influence, is the main source of phosphorus and will be I difficult to control. He asked Dr. Mitchell whether an estimate could be made of the percentage of agricultural products as compared with septic system drainage into the lake. I Dr. Mi tchel 1 responded that not more than 25/C of the nutrients in the lake is from septage. He said that the government supports a non-point source reduction program for I the Clean Lakes Program which is now not funded but eventually wil 1 be. He said that control of runoff from Route 119 will I help. I I I I Clean Lakes Committee Public Meeting March 8. 1939 • -4- Jody Lapham, Clean Lakes Committee member and Knopps m Pond resident with a tight tank disposal system, asked i f • there were no action taken now, how long would it be before a new study is needed. Dr. Mitchell responded between three and five years, a short period because of the considerable • development already planned for the lake area. * Richard McLaughlin asked when can the town-initiated program start, and Dr. Mitchell responded October to • December, It needs moni toring, and a Notice of Intent and | permits are required before commencing. Grotcnwood Conference Center Director Edmund Guerard inquired about whose initiative H and responsibilities were involved in the siphoning project. • Dr. Mitchel1 said it is only done during dry conditions in October and when the groundwater is low. In answer to Bob Lewis' question whether, if the lake level were lowered, could • growth be taken to dump?, Dr. Mi tchel1 responded that the • fmaterial must be allowed to de-water for a period before it can be hauled to the landfill and there is no area on the lake • where this could be done. | Jody Lapham asked how one secures aqua screen on this silt bottomf and was informed that it has to be on a shore « with somet hi ng of a st ony hot t cm. • In response to Alex Woodless question what might be done about the valisneri a he finds so troublesome off his shore, he was told that it is a matter of targeting the most • serious weed nuisance and Eurasian milfoil is the target. • Baystate's Dr. Kenn Wagner said that Bendi k barrier is effective for valisneria. . !• Phi lip Trudeau of the Clean Lakes Committee added that • depending on the macrophytes, weed reduction can be accomplished in from 3-7 years. While the effect may be fish population reduction, it enables the larger fish to attain • greater size by easier access to feed on smaller fi sh. Lost • Lake/Knopps Pond is a two tier fishery: warm water with a 1arge number of bass and pi ckerel, and cool water where trout • can thrive. . | Mr. Lapham then inquired about the new Ruck system. Dr. Mitchel1 enumerated various solutions. The cheapest is to M pump the system regularly. Some homes have cesspools which • may need replacement with a new leach field. ™ Holding tanks are an expensive choice because they require much pumping and maintenance. ' • Clivus multrim and a gray water leach fieldisa I possibi1ity. I I I i I Lakes Committee Public Meetina I March 8, 19S9 The Ruck System, Dr. Mitchel1 explained, is a system I where solid waste is treated separately in a smal1 leach field, where wastewater gets rid of nitrogen and phosphorus, then joins gray water in a conventional leach field. A reduced I size leach field can be used. This can be especially suited to smaller Lost Lake/Knopps Pond lots. Responding to inquiries about liability, Dr. Wagner I said that it is a private project, with a company having total rights held publicly and subject to town vote. An example is Forge Pond in West ford and Littleton. Drawdowns had been conducted regularly by Abbot Mi 11 unti1 1955, so sediment I never built up at edges of the lake. When the mill closedf there was then no drawdown for 30 years, and now there is heavy weed growth. While there has been no signi fleant change I introduced to the lake, bureaucratic decisions have complicated the logical solution of resuming drawdowns: the state says there are contiguous wetlands to be protected, and Murray Printing Company now occupying the Abbot Mill building, I had been willing to conduct drawdowns until it realized this would limit its customary use of lake water for cool ing and for printing. I Richard Malagodi asked whether the Army Corps of Engineers would be involved and Dr. Wagner said it would, along with the Conservation Commission, DEQE? Division of I Waterways, Department of Environmental Management, etc., al1 of which take time to clear. In discussion as to how to monitor the pond water level t Dr. Mitchell suggested that a stick in a kettle hole I that generally contains water would be adequate.. Mr. Malagodi inquired about cost of instal1 ing aquascreen. Dr. Mitchell said 37 cents sq/ft.f the figure I generally being given is $15,COO/acre. But it is basic ally just fiberglas screen which he has obtained from Agway. Mr. Lewis suggested checking for possible further information with I the Rod and Gun Club of Lake Massapoag which is now actively working on their weed problem. Dr. Mitchell said the draft final report will be submitted in another month and would be subject to a three I month period of review and comment by town and state. I The meeting ended at 9:40 p.m. Respect fully submitted, I Marjcnjle Eger, ^recording I I I I I BAYSTATE ENVIRONMENTAL CONSULTANTS April 4, 1989 I NC Ms, Brona Simon State Archaeologist Technical Services Division I Massachusetts Historical Commission 80 Boyleston Street Scientists Boston, MA 02116 I Engineers Planners Dear Ms. Simon, Baystate Environmental Consultants (BEC), Inc., as I part of the review process for the Diagnostic /Feasibility Study for Lost Lake / Knopp's Pond, Groton are contacting the Massachusetts Historical I Commission for information regarding significant historic or archaeological resources in the vicinity of Lost Lake / Knopp's Pond. We request I that you forward your findings to us in letter form at your earliest convenience. We have enclosed a project summary detailing I suggested restoration options for the lake, as well as a locus map of the Lost Lake / Knopp's Pond watershed; taken from the USGS Ayer I topographic quadrangle map. Should your office need any additional information, please do not hesitate to contact me. I Thank you for your cooperation in this matter. Very truly yours, I BEC, Inc. I David F. Mitchell, Ph.D Asssociate I d.227 I I I 296 North Main Street East Longmeadow, MA 01028 (413) 525-3822 I An Sawol Oooortunitv E I I I BAYSTATE JNVIRONMENTAL CONSULTANTS April 3, 1989 NC Mr. Jay Copeland I Environmental Reviewer Massachusetts Natural Heritage Program Division of Fisheries and Wildlife I 100 Cambridge Street Scientists Boston, MA 02202 Engineers I Plonners Dear Mr. Copeland Baystate Environmental Consultants (EEC), Inc., as part of the review process for the Diagnostic /Feasibility Study for Lost Lake / Knopp's Pond, Groton are contacting the Massachusetts Natural Heritage Program for information regarding rare I species and ecologically significant natural communities in the vicinity of Lost Lake / Knopp's Pond. We request that you forward your findings I to us in letter form at your earliest convenience. We have enclosed a project summary detailing suggested restoration options for the lake, as I well as a locus map of the Lost Lake / Knopp's Pond watershed; taken from the USGS Ayer topographic quadrangle map. Should your office I need any additional information, please do not hesitate to contact me. I Thank you for your cooperation in this matter. Very truly yours, i BEC, Inc. i David F. Mitchell, Ph.D i Associate i d.227 i 296 North Main Street i East Longmeadow. MA 01028 525-3822 i An Equal Opoo"wf»'[v Employ*' I I Dear Watershed Resident: I As part of our effort to assess conditions and their causes in • your lake and watershed, Baystate Environmental Consultants, Inc. | requests that you fill out the attached questionnaire and return it to either the BEC office, Att. Lakes Section (address given m below), or the designated representative in your area. Your I cooperation will be greatly appreciated, and will contribute to our analysis of the lake and the development of a management strategy for it. All information will remain confidential; we I ask for a name and address only for follow-up/clarification H purposes, and will not release this information to anyone outside our office. If you are uncomfortable providing a name and • address,.simply leave that space blank. The results of the | questionnaire survey will be tallied and presented as a table in which responses to specific questions will be expressed as a _ number or percent of the total. For example, listings will • include the percent of respondents favoring each listed lake use, the average age of waste water disposal systems, and the percent of households using washing machines. No individual data will be I given. Again, it is very important that we receive enough I questionnaires to perform a valid analysis. Please assist us by taking the time to fill out this form and returning it. • Thank you for your cooperation, i for the EEC staff BEC, Inc. i Attention Lakes Section 296 North. Main Street » East Longmeadow, MA 01028 I (413) 525-3822 i i i i i i I QUESTIONNAIRE FOR WATERSHED RESIDENTS I Name Phone Street Address (Not Mailing) w Nearest Lake or Waterway Jl 1. Number of people in household? 2. Number of months in full time residency? I 3. Distance of property from lake? 4. Do you make use of the lake? I At Least Daily? At Least Weekly? Monthly or Less? 5. Preferred activities on the lake? i 1. 2. i 3.' 6. Where do you get your drinking water? 7. Where do you get your washing water? 8. Do you have an in-ground waste disposal system? i (If not, where are wastes disposed?) 9. If you have a well and/or in-ground waste disposal system: i a. -What kind of disposal system do you have (i.e. cesspool, tank and leachfield, pipe to lake, etc.)? i b. Approximate age of disposal system? c. Distance of disposal system from lake? i d. what kind of well do you have? i e. Approximate depth of well? i f. Distance of well from lake? i i i i g. Distance between well and disposal system? * h. Is well upslope, downslope, or alongside of • disposal system? • i. When was well water last tested? • j. When was disposal system last inspected/maintained? k. Any known problems (quantity or quality) with • well or disposal system? ™ 10. Do you use a washing machine on the premises? • 11. Do you use a garbage disposal on the premises? 12. What kind of detergent do you use? I a. For clothes? b. For dishes? I 13. Do you fertilize your lawn? 14. Do you have any questions or comments? Please feel free to use i space on this page or an additional sheet to respond. i i i i i i i i i i i I I I I I I I APPENDIX D. . Data and Calculations. 1. Water Quality Data. 2. Biological Data. 3. Calculation Sheets and Useful Conversions. 1. Water Quality Data. .*r \f 1 ^ n\>L *?* J?J Ats)r // 1 / FLCW (CFS) IN THE LDST^KE/KNOPP'^PCND SYSTEM FLCW (CU.M/MIN) IN THE LOST LAKE/KNOPP'S PtND SYSTEM I STATION KP-1 ( KP~? Up-6) (^KP-T) STATION KP-1 KP-2 KP-6 KP-7 • DATE v> v_y \U/ EteTE 10/22/87 0.0 3.5 .2 10/22/87 0.0 4.0 .3 11/19/87 0.0 2.6 4.6 11/19/87 fl.fl 4.4 7.8 112/17/87 1,8 6.8 11.3 12/17/87 3.1 11.6 19,2 01/21/88 1.1 1.6 3.0 01/21/88 1.9 2.7 5.0 _ 02/25/88 2.7 3.9 13.3 02/25/88 4.4 6.4 22.6 • 03/14/88 2.9 4.2 4.5 .1 03/14/88 4.9 7.1 7.4 .1 • 04/04/88 1.4 5.5 7.3 .2 04/04/88 2.4 9.3 12.4 .3 ™ 04/18/88 1.6 1.4 .2 .3 04/18/88 2.7 2.4 .3 .5 05/09/88 1.8 .9 .4 .2 05/09/88 3.1 1.5 .7 .4 05/23/88 2.0 .8 1.8 ,1 05/23/88 3.4 1.4 3.1 .3 06/08/88 1.2 2.1 .1 06/08/88 .5 2.0 3.4 .3 106/20/88 O~ .8 1.6 .1 06/20/88 0.0 1.4 2.7 .1 07/04/88 0.0 .1 .7 .1 07/06/88 0.0 .3 1.2 .2 .. 07/19/88 0.0 .2 1.6 .1 07/19/88 0.0 .3 2.7 .2 • 08/11/88 0.0 .1 .2 .1 08/11/88 0.0 .3 .3 .2 • 08/25/88 8.0 .2 .8 .1 08/25/88 0.0 .3 1.4 .1 09/08/88 0.0 .2 3.0 .1 09/08/88 0.0 .4 5.1 .2 09/26/88 0.0 .1 3.5 .1 09/24/88 0.0 .3 6.0 .1 MAXIMUM 2.9 6.8 13.3 .30 MAXIMUM 4.9 11.4 22.6 .51 MINIMUM 0.0 .1 .2 .05 MINIMUM 0.0 .3 .3 .09 — MEAN .9 1.9 3.3 .13 MEAN 1.5 3.2 5.7 .22 TEMPERATURE MAXIMLM 19.0 26.5 29.4 26.3 / 19.0 29.9 29.2 29.4 23.1 29.9 19.2 MINIMUM -1.4 -3.5 0.0 14.3 / 2.0 5 2.9 0.0 2.5 -1.0 7.7 MEAN 8.8 12.3 16.2 19.5 / 9.9 14.5 16.6 15.9 13.0 15.4 13.2 I I \ 1^' I ,-\ ^ 'S \ r^ // °rV* r1 L/ \ * . M&* > A f-/j /-/ Y^ I \ v^fiud-Tiv v / I I DISSOLVED OXYGEN •7 q -r I iu/21/37 9.7 i U i 7 ' . L' ^•'o 1 ! ,1 }?'i 11/19/87 12.3 2!? 13 14 1 >j I V* 12/17/87 15.0 13i3 14.7 isis 15.2 01/21/88 15.7 12.0 12.7 7 .5 i? q 11.2 -3.5 12.3 02/25/88 p o 10,4 7 ^T I 03/14/83 1L4 10.1 12.3 7.4 n 04/04/38 9.5 S.9 11.4 1.3 1G .Q 7.6 11.1 11.8 9.5 6.9 04/18/88 10,6 11.3 1< 1 i .^ V 5,3 10 .7 7.8 11.0 1.6 9.0 i , £• n / i Q5/G9/S8 7 .O 8,6 10.3 2,6 9 9.6 9.6 5.8 8.9 7 *•! c c 0 1 / . D 7 7 I 05/23/88 8.3 7.8 1,7 8 IT 3.5 8.4 06/09/SS 9.5 7.8 9,0 11.3 \ • cO &.5 7^5 9.0 4.8 9.0 O.I 06/20/S8 6.6 8.2 11.0 273 7.4 ^Vo) 7.9 i .2 8.0- i' . / 1 ^ r. 07/06/88 8.8 9.4 li.O li^ 9 • / 47fr 9.8 '. . i 9,5 8.4 T '"J •7 C 1 07/19/S3 7.0 7.7 7.6 "^ - 7 3.6 l' • X. /Tl^ ^ I 08/11/88 5.9 7.4 9.3 c^r^ i.6 7.3 7.1 \.3./ 7,3 6 is 7 i o -• 08/25/88 8.2 7.7 7 ^ 1T5 S .6 7.3 4,2- 6.5 09/08/88 Q 0 8.3 /^T" \ 9 .7 9.5 8. '4 Co 8.8 sir 0?/26/8S sis S.i (^ s .^ 7 ^ 7.6 o.t i< . / 5,9 I MAXIMUM 15.7 13.3 12.7 12.8 ^^. 4• tI dr. .4 7.4 14.7 13.8 15.2 S'.2 MINIMUM 8.8 5.9 7.4 7,3 .4 7 .2 .6 7.1 •y 6.5 c; i MEAN U. 4 9.0 Q c 9.9 2.4 9 .5 7.2 9.7 siT 9.4 7.4 I I I I I I I I I I I I I PH I MAXIMUM .08 .47 .13 .02 .12 .11 .10 .28 .22 .33 .05 MINIMUM .02 .02 .01 .02 .01 .01 .01 .01 .01 .01 .02 I MEAN .05 .15 .04 .02 .04 .03 .03 .05 .04 .05 .02 I ORTHOPHOSPHORUS (UG/L) IN THE LOST LAXE/KNOPP'S POND SYSTEM STATION KP-1 KP-2 KP-3S KP-3W KP-3B XP-4S KP-4B XP-5S IP-SB XP-6 KP-7 DATE I 10/22/87 48 10 10 10 10 10 10 10 11/19/87 10 10 10 10 • 10 10 10 10 12/17/87 10 50 10 20 10 01/21/88 10 51 10 10 10 10 10 10 02/25/88 14 10 10 13 13 10 14 16 I 03/14/88 10 20 10 10 OV04/88 10 20 10 10 10 10 10 10 10 04/18/88 22 31 20 17 13 33 49 22 29 75 05/18/88 22 33 16 26 10 17 22 24 16 12 05/23/88 10 10 10 10 10 10 20 10 20 10 I 06/09/88 10 10 10 30 10 10 10 10 10 10 10 06/20/88 60 10 20 10 10 10 10 10 10 30 07/06/88 70 30 30 20 30 30 20 40 20 50 07/19/88 ^9(L 10 20 20 30 10 20 20 10 80 10 10 10 40 I 08/11/88 (140y) 10 10 10 10 10 08/25/88 ^80 10 10 10 10 10 10 10 10 09/08/88 40 10 10 10 10 10 10 10 10 I 09/26/88 40 10 10 10 10 10 10 10 20 MAXIMUM 22 140 30 30 26 30 33 49 40 29 80 MINIMUM 0 10 0 0 0 0 0 0 0 10 I MEAN 13 46 12 18 13 13 14 15 15 13 21°8 I I I TOTAL PHOSPHORUS (UG/L) IN THE LOST LAKE/KNOPP'S POND SYSTEM STATION XP-1 XP-2 KP-3£' KP-3H KP-33 KP-4S KP-4B XP-5S KP-53 £P-6 ZP-7 DATE 10/22/87 96 2' 15 16 42 10 29 19 11/19/87 50 1C 20 10 10 20 30 30 12/17/87 30 70 40 60 60 01/21/88 61 150 5< 72 42 65 42 30 02/25/88 40 66 IS 22 39 38 45 63 03/14/88 260 46 29 21 04/04/88 17 185 2* 23 ' ' 23 26 " 21 22 22 04/18/88 53 84 4" 49 37 47 84 32 43 cr4f> 05/18/88 47 74 4: 62 21 34 47 47 33 ^25 05/23/88 30 10 1C 30 30 10 30 10 50 20 06/09/88 15 40 3Gr> 40 10 30 50 40 40 40 06/20/88 130 ,71 1 40 20 60 60 40 90 cifb 90 07/06/88 80 (40 40 40 30 30 20 40 50 80-, 07/19/88 150 70 70 80 80 80 60 60 70 CllO) 08/11/88 190 50 1 40 40 30 30 40 ^40 60 Q40> 08/25/88 120 k5C J 20 30 20 ;io> ' 10) — ClO) 110) 09/08/88 60 2C 40 30 30 30 40 30 50 09/26/88 170 70 60 60 90 80 80 60 70 MAXIMUM 260 190 70 70 80 80 90 84 90 110 141 MINIMUM 15 10 10 40 10 10 10 10. 10 10 10 MEAN 61 98 ,40^ 46 38 ^36) 41 42 45 63 ^ NITROGEN TO PHOSPHORUS RATIOS IN THE LOST LAKE / KNOPF'S POND SYSTEM. STATION KP-I KP-2 KP-3S KP-3M KP-3B KP-4S KP-4B KP-5S KP-5B KP-6 KP-7 DATE 10/22/87 19 34 - 60 55 22 106 38 38 11/19/87 17 51 31 64 64 34 46 22 12/17/87 34 19 (15) 15 13 01/21/88 20 25 16 10 15 04 21 27 02/25/88 24 32 44 31 32 39 • 29 26 03/14/68 3 32 30 29 04/04/88 56 9 21 114 27 29 37 31 16 04/18/88 21 18 /1 3-1 14 22 47 d4\ 77 34 7 05/18/88 22 19 U2/ 9 37 27 \l) 16 25 20 05/23/88 49 130 57 27 26 106 21 84 22 10 06/09/88 85 29 1?~ 14 69 26 18 21 34 26 15 06/20/88 8 C7? 20 22 Cl4> 15 16 10 8 8 07/06/88 15 20 20 20 27 30 & 28 16 7 07/19/88 13 C\O 11 10 02) 15 I CHLORIDE (MG/L) IN THE LOST LAKE/KNOPF'S POND SYSTEM STATION KP-1 KP-2 XP-3S KP-3M KP-3b KP-4S KP-4b KP-5S KP-5b KP-6 KP-7 DATE I 10/22/87 34.0 26.0 22.0 32.0 22.0 28.0 26.0 28.0 11/19/87 29.0 27.0 27.0 26.0 26.0 26.0 27.0 26.0 12/17/87 3.4 29.0 25.0 25,0 26.0 01/21/88 11.0 30.0 22.0 28.0 25.0 26.0 29.0 30.0 I 02/25/88 4.5 30.0 21.0 26.0 14.0 17.0 30.0 28.0 03/14/88 5.1 26.0 21.0 17.0 04/04/88 3.0 30.0 32.0 25.0 18.0 18.0 18.0 21.0 32.0 04/18/88 10.0 36.0 28.0 27.0 23.0 22.0 23.0 23.0 19.0 27 ;0 05/09/88 6.9 32.0 27.0 27.0 19.0 23.0 22.0 21.0 21.0 20.0 I 05/23/88 5.0 32.0 27.0 26.0 24.0 23.0 21.0 23.0 21.0 25.0 06/09/20 6.8 28.5 28.5 25.0 28.5 24.0 25.0 21.3 25.0 21.3 25.0 06/20/88 29.6 28.2 28.5 26.4 23.5 24.2 24.9 24.9 24.9 26.0 07/06/88 30.0 26.7 26.4 24.2 23.1 24.5 22.7 22.0 24.2 14.1 I 07/19/88 22.0 24.0 23,0 23.0 26.0 21.0 26.0 21.0 24.0 11.0 08/11/88 30.0 30.0 30.0 30.0 28.0 29.0 26.0 29.0 17.0 26.0 08/25/88 30.0 32.0 32.0 30.0 29.0 27.0 27.0 29.0 17.0 09/08/88 29.0 30.0 29.0 28.0 26.0 27.0 26.0 26.0 15.0 I 09/26/88 33.0 34.0 32.0 30.0 31.0 30.0 30.0 30.0 23.0 MAXIMUM 11.0 36.0 34.0 30.0 32.0 32.0 31.0 .30.0 30.0 30.0 32.0 MINIMUM 3.0 22.0 21.0 23.0 22.0 14.0 21.0 17.0 18.0 17.0 11.0 I MEAN 6.2 30.0 27.7 26.6 27.1 24.6 25.1 24.2 25.1 24.3 21.4 I TOTAL IRON (MG/L) IN THE LOST LAKE/KNGPP'S POND SYSTEM I STATION KP-1 KP-2 KP-3S KP-3M KP-3b KP-4S KP-4b KP-5S KP-5b KP-6 KP-7 DATE 10/22/87 .44 .12 .14 .08 .44 .03 .05 .03 I 11/19/87 - .17 .11 .24 .02 .03 .02 .24 .02 12/17/87 .26 .11 .02 .02 .02 01/21/88 .36 .28 .02 .02 .02 .02 .06 .02 02/25/88 .23 .12 .09 .04 .15 .05 .05 .09 03/14/88 .21 .17 ^ .16 .38 I 04/0 4/88 .23 .15 .07 > .05 .09 .07 .23 5 ^-i- ^ 04/18/88 .25 .23 .15 d^L- .12 .21 .11 .11 .15 FSCAL COLIFORH (N/100 ML) IN THE LOST LAEE/HiQPP'S POND SYSTEM I STATION KP-1 KP-2 KP-3S KP-4S KP-5S KP-6 KP-7 DATE 10/22/87 4 10 10 10 10 I 11/19/87 20 0 0 0 0 12/17/87 90 10 10 , 01/21/88 10 (1000) 10 10 10 10 02/25/88 10 ^20 10 10 10 10 I 03/14/88 10 10 10 10 04/04/88 10 10 10 10 10 /JO 10 04/18/88 10 10 10 10 10 10 10 05/09/88 10 10 10 10 10 10 10 05/23/88 10 10 10 10 10 20 10 I 09/09/88 210 10 10 10 10 10 10 06/20/88 40 10 10 10 10 10 07/06/88 dP°-^> 10 10 10 10 20 07/19/88 20 10 10 10 10 10 I 08/11/88 90 10 10 10 10 350 08/25/88 270 10 10 10 10 10 09/08/88 90 10 10 10 10 40 I 09/26/88 80 10 10 10 10 10 MAXIMUM 210 1000 10 10 10 20 350 MINIMUM 10 4 0 0 0 0 10 MEAN 41 205 9 9 9 10 39 I GEOMETRIC MEAN 18 43 9 9 9 9 15 I FECAL STREPTOCOCCI (N/iOQ ML) IN THE LOST LAI£/KNOPP'S POND SYSTEM STATION KP-1 KP-2 KP-3S KP-4S KP-5S KP-6 KP-7 DATE I 10/22/87 75000 50 50 420 11/19/87 6000 20 0 0 50 12/17/87 1000 62000 2000 2000 01/21/88 1000 53000 960 210 150 110 02/25/88 . 1000 1900 1000 1000 15000 13000 I 03/14/88 1000 6000 5000 650 04/04/88 10000 35000 1000 7000 4000 27000 35000 04/18/88 80000 40000 40 3000 10000 26000 13000 05/09/88 10 10 10 10 10 10 10 I 05/23/88 10 10 10 10 10 10 10 06/09/88 10 10 - 10 10 10 10 10 06/20/88 90 10 10 10 10 10 07/06/88 390 10 10 10 10 30 07/19/88 420 10 * 70 10 10 10 I 08/11/88 420 10 10 10 10 2000 08/25/88 5000 10 10 50 10 20 09/08/88 100 10 10 10 10 30 I 09/26/88 50 10 10 10 10 10 MAXIMUM 80000 75000 1000 7000 15000 27000 35000 MINIMUM 10 10 10 0 0 10 10 MEAN 10448 15856 198 714 1865 4309 3907 I GEOMETRIC I I I I I Fecal Coliform : Streptococci Relationship (from Tchobanoglous and Schroeder, 1985 I I Th* Ratio of F*cal CoTrforrm to Fecal Streptoctxci It has been observed that the quantities of fecal coliforms and fecal streptococci that are discharged by humans are significantly different I from the quantities discharged by animals. Therefore, it has been sug- gested that the ratio of the fecal coliform (FC) count to the fecal streptococci (FS) count in a sample can be used to show whether the suspected contamination derives from human or from animal wastes I [3.14]. Typical data on the ratio of FC to FS counts for humans and various animals are reported in Table 3.8. The FC/FS ratio for humans is more than'4.0, whereas the ratio for domestic animals is less than 1.0. I If ratios are obtained in the range of 1 to 2, interpretation is uncertain. The foregoing interpretations are subject to the following con- straints: I 1. The sample pH should be between 4 and 9 to exclude any adverse effects of pH on either group of microorganisms. 2. At least two counts should be made on each sample. I 3. To minimize errors due to differential death rates, samples should not be taken farther downstream than 24 hr of flow time from the suspected source of .pollution. I 4. Only the fecal coliform count obtained at an incubation temperature of 44°C is to be used to compute the ratio [3.14], I TABLE 3.8 I Estimated Per Capita Contribution of Indicator Microorganism* from Human . Beings and Some Animals AVERAGE INDICATOR AVERAGE I ORGANISM DENSITY PER g COm-RIBUTTONPER OF FECES CAPITA/24 hr Fecal Fecal Fecal Fecal coliform, streptococci, coliform, streptococci, RATIO I ANIMAL 10s 10* 10* 10* FC/FS Human 13.0 3.0 2,000 450 4.4 Chicken 1.3 3.4 240 620 0.4 I Cow 0.23 1.3 5,400 31,000 0.2 Duck 33.0 54.6 11,000 18,000 0.6 Pig 3.3 84.0 8,900 230,000 0.04 Sheep 16.0 I 38.0 18,000 43,000 0.4 Turkey 0.29 2.8 130 1,300 0.1 Source: From Ref. [3.14J. I 3.14. Mara. D. D., (1976), Sewage Treatment in Hot Climates, John Wiley and Sons, Chkhester, England. I I I I I CHLOROPHYLL (UG/L) IN THE LOST LAKE/KNOPP'S POND SYSTEM STATION KP-3 KP-4 KP-5 DATE 10/22/87 2.1 1.9 I 11/19/87 .8 3.4 12/17/87 1,8 01/21/88 1.1 .6 .6 02/25/88 1.3 .1 .7 I 04/04/88 1.8 1.8 4.1 0 VI 8/88 1.7 i.9 3.3 05/09/88 .84 2.4 2.1 05/23/88 1.9 1.5 2.5 06/08/88 2.9 2.5 2.9 I 3.3 06/20/88 1.4 2.2 07/06/88 2.1 1.9 1.5 07/19/88 1.5 3.6 1.5 08/11/88 4.4 1.1 2.6 I 08/25/88 2.0 1.1 1.8 09/08/88 1.3 .9 1.5 I 09/26/88 1.3 1.2 1.6 MAXIMUM 4.4 3.6 4.1 MINIMUM .8 .6 .6 I MEAN 1.9 1.6 2.1 I I I I I I I I I I I kP-3 092633 Xr-4 092603 KP-5 092698 TAXCN CELLS/ML TAXCN CELLS/ML TAXOH CELLS/ML 3AC1LLARIOPHYTA SACILLAfliOPHYTA I BACILLARIOFHYTA 7.4 FrasjlUrla 221.7 Cyclotelld fragllarla ' .£ PI euros i^na 3.7 Syneara 3,S CHLCRCPHYTA Synedra 3.7 TiOstlarU 25.4 Tabeilarla [3.7 I Qocyatla IS. 8 CHLOKOPHYTA Quadrlgula 63.3 CHLOROPHYTA Ouadr \svit 29,0 CYANOPHYTA Pedlaatrura 22.4 CHRYSOPHYTA Aphanocapaa 182*. 6 CHRYSOPHYTA I Chroococcua <7.5 Oircnul Ina 3.6 Hlcrocyatla ,s^4f4^-~ Dlnobryon 26.1 DlnoDryon 18.1 ( } Other golden algae 174.2 ^-~ '-^ OtYPTQPHYTA TOTAL 6644.8 CRYPTOPHYTA Cryptomonaa 18.7 I eAClLLARIOPHYTA 221.7 Other cryptophytes 47.t CTAHOPHYTA CHLOROPHYTA 79.2 CYANOPHYTA Aph«nocapsa 261. 8 UVANQPHYTA 6343.9 Anabaena 65. 3 Aphinocapa* 700.4 I TOTAL 362.7 EUGLENOPHYTA TAXCN OC/L BACILIARIOPHYTA 33.6 Euglen* 3.6 SACILLARIOPHYTA CHLORDPHYTA 22.4 I PYRRHOPHYTA Fragllarla 443.5 CHRYSOPHY7A 26.1 Csratlum 3.6 CHLQKJPtfYTA CRYPTOPHYTA 18.7 Clenodlnlum 3.6 Qocyatla 47.5 CYANOPHYTA 26!. S TOTAL 1165.2 I Quatirigula 12.6 BACILLARIOPHYTA 36.3 CTANQPUYTA TAXOT UG/t CHLOROPffYTA 29.0 Aphanocapaa 34.6 BACILLARIOPFiYTA CHRYSOPHYTA 196.0 I Chcoococcua .4 Hicrocyatla 44.7 Cyclotella 18.7 CRYPTOPHYTA 47.1 Pleyrosl^na 11.9 TOTAL 603.5832 Syneara 2.9 CYANOPKTTA 845.7 Tabs 11 an a 56.1 EUCLEMOPHYTA I BACILLARIOPHYTA 443. S 3.6 CHLOROPHYTA CHLCROPHYTA 60.1 PYRRHOPKYTA 7.2 Pea last rum 4.4 CYANOPHYTA 99.8 TAXON UG/L CHRYSOPHYTA I BACILLARIOPHYTA Dlnotsryon 78. S Fragi larla 14.5 CRYPTOPHYTA Synedra 2.9 - Tabellarla 457.3 Cryptomonis 18.7 I , CHLOROPHYTA CYANOPHYTA Ouadriguta S.3 Aphanocapaa 7.8 CHRYSOPHYTA I TOTAL 197.342 Oironul Ina .7 Dlnobryon 54.4 BACILLARIOPHYTA 89.7 Other golden algae 87.1 CHtOPOPKVTA •<.« CSYPTOPHYTA I CHRYSOPHYTA 73.5 Other cryptophytes 47.1 CRYPTOPHYTA 18.7 CTANOPHYTA CYAHOPHYTA 7.3 Anabaena 202.5 I Aphanocapaa 23.4 EUGLEHOPHYTA Euglena t.e I PYRRHOPHYTA CcralJvn 871. 2 Glenodlniun 10.8 TOTAL 1779.9 I BACaLARlOPHYTA 474.8 CHU3ROPHYTA 5.8 CHRYSOPHYTA 142.2 I CRYPTOPHYTA 47.1 aANOPHYTA 2^3.7 EUGLEHOPHYTA 1.8 I PYRRHOPKYTA 882.0 I TAXOJ ' CELLS/ HL TAXCM CELLS/ML TAXCN CELLS/ HL I BACILLARIQPHYTA CHLOROPHYTA BACILLARIOPHYTA Asterlonei la 27.3 Anklatrodesnus 1.4 Synrdra 1.7 C/clotella 16.3 Fragl larta 50.9 CRYPTOPHYTA CHLOROPHYTA CHLOROPHYTA I Cryptoraonaa 1.4 Anlclstrodesnus 1.7 Other cryptophytea 1.4 Oocyatla 5.4 CHRYSOPHYTA CYANOPHYTA CHRYSOPHYTA Chromul Ina 17.1 Anaoaena 20.9 Chrcntul Ina I 1.8 CaYPTOPHYTA HJCLENOPHYTA CYANOPHYTA Crypt croon as 29.0 Phacua 1.4 78. 6 Chroococeua 14.5 Other cryptophytes CYANOPHYTA I TOTAL 26.8 TOTAL 116.4 Chroococcua 13.6 CHLOROPHYTA 1.4 BACILLARIOPHYTA 94.6 EUGLENOPHYTA CRYPTOPHYTA 2.? CHLOROPHYTA 5.4 I Tr ache 1 ananas 3.4 CYANOPKYTA 20.8 CHRYSOPHYTA i.a PYRRHOPHYTA EUGLENOPHYTA 1.4 CYANOPHYTA 14.5 I Glenodlnlum 1.7 TAXON UGVL TOTAL 147.0 TAXON UG/L CHLOROPHYTA BACILLARIQPHYTA 1.7 BACILLARIOPHYTA Ankistrodesmua .7 1.7 I Aaterlonella 19.1 CHLOROPHYTA 40.9 CyclotelU . CHYPTOPHYTA CHRYSOPHYTA 17.1 FragllarU 101.? Crypt croonaa 1.4 CRYPTOPHYTA 107.7 CHLOROPHYTA Other cryptophytea 1.4 I CYANOPKYTA 13.6 Oocystls 2.1 CYANOPHYTA EUGLENOPHYTA 3.4 CHRYSOPHYTA Anaoaena 64.6 PYRRHOPHYTA 1.7 I Chr omul Ina .3 EUGLENOPHYTA CYANOPHYTA Phacus .4 TAXON UG/L Chroococcua 5.8 TOTAL 63.8 BACILLARIOPHYTA I TOTAL 170.3 CHLOROPtfYTA .7 Synedra 76.9 BACILLARIOPHYTA 161.9 CRYPTOPHYTA 2.9 CHLOROPHYTA CHLOROPHYTA I 2.1 CYANOPHYTA 64.6 Ank I strode sou 9 .6 CHRYSOPHYTA .3 EUGLENOPHYTA .4 CHRYSOPHYTA CYANOPHYTA 5.8 ChromuHna 3.4 I CRYPTOPHYTA Crypt oroonas 29.0 Other cryptophytea 76.6 I CYAtfOPHYM Chroococcua 5.4 EUGLENOPHYTA I Trachelomonaa 3.4 PYRRHOPHYTA Glenodlnlum 42.7 I TOTAL 240.5 BACILLARIOPHYTA 76.9 I CHLOROPHYTA .8 CHRYSOPHYTA 3.4 CRYPTOPHYTA 107.7 I CYANOPKYTA 5.4 EOCLENOPHYTA 3.4 I PYRRHOPHYTA 42.7 I TA.XCN CiLLi^L 8ACILLASIOPHYTA I Cyctctei la 4.C CKSYSCPHTTA I Giromullna 4.2 Dlnooryon SOI. 9 Kallomonas A. 2 Synura 66. S CRYPTGPHYTA I 21.4 TOTAL 604.3 I BACILURIOPKYTA 4.2 CHRYSOPHYTA 579.1 CSYPTOPHYTA 21.4 I TAXON UG/L I CyclotslU tO. 7 CHRYSOPHTTA Chconutlna .3 I DlnoOryon lSaS.7 flallomonaa 2.1 Synura 137.2 CHYPTOPHYTA I 21.4 TOTAL 1S73.2 I 3ACIlLARrOPHYTA 10.7 CHRYSOPHYTA 1646.0 CRYPTOPKYTA 21.4 I I I I I I I I I I \F-3 11196"? c ) TAXGN CELLS/ML TAXCN CELLS/TIL BACILLARICPKYTA BACILLARIQPHYTA Asterlonel la 6.6 Aaterlonel la 13. S Cyclotella 3.3 Cvclotella 10.2 Fragl I aria 511,5 CHLOROPHYTA Synedra 3.4 Splrcgyra 19.8 CHLOROPHYTA CHRYSOPHYTA HougeotU 3.4 Sceneoegrnus 27.2 Dlnooryon 1970.1 Synura 112.2 CHYPTOPHYTA CRYPTOPHYTA Crypt craonag 37.5 Cryp tomon as 26.4 CYANOPHYTA CYANOPHYTA Aphanocapaa 586. S Chroococcus 134.1 Oaclllatorla 396 EUGLENOPKYTA EUGLEHOPKYTA Trache 1 omanas 3.4 Phacus 3.3 PYRRHQPKYTA PYRRHOPHYTA PerldlnJum 3.4 Perldlnluo 3.3 TOTAL 1384. 4 TOTAL 2541 BACILLAR10PKYTA 538.7 BACILLARIOPHYTA 9.9 CHLOROPKYTA 30.6 CHLOROPHYTA 19.8 CRY?TQ?Hm 37.5 CHRYSOPHYTA 2082.3 CYAKOPHYTA 770.6 CRYPTOPHYTA 26.4 EUGLENOPKYTA 3.4 CYAKOPHYTA 396 PYRRHQPHYTA 3.4 EUGLENQPHYTA 3.3 PYRRHOPHYTA 3.3 TAXOH UG/L BACILLARIOPHYTA TAXOH UG/L Astertonel 1 a 9.5 BACILLARICPHYTA C/clotella 2S.5 FragtUria 1023 Aaterlonel la 4.6 Synedra 27.2 Cyctotella 8.2 CHLOROPHYTA CHLOROPHYTA Mougeotla 53.5 Splrogyra 3960 Scenedearous 2.7 CHRYSOPHYTA CRYPTOPHYTA HI notary on 59(0.3 Crypt omonag 37,5 Synura 224.4 CYAKOPHYTA CRYPTOPKYTA Aphanocapaa 17.5 Cryptcmonas 26.4 Giroococcua 52.3 CYAHOPHYTA EUGLENOPHYTA Oscillatorta 3.9 Trache 1 cmonaa 3.4 EUGLENOPHYTA PYRRHOPHYTA Phaeua .9 Perldlnluo 632 PYRRHOPHYTA TOTAL 1934.5 Perldlnlun 660 10799.9 BACILLARIOPHYTA 108S. 4 TOTAL 12.8 CHLOROPHYTA S6.2 BACILLARIOPHYTA 3960 CRYPTOPHYTA 37.5 CHLOROPHYTA 6134.7 CYANOPHYTA 69.9 CHSYSOPBYTA 25. 4 EUGLENOPHYTA 3.4 CRYPTOPHYTA 3.9 PYRRHOPKYTA 682 CYANOPHYTA EUGLENOPHYTA .9 PYRRHOPKYTA 660 KP-3 102297 K?-5 102237 C5U.S/ML TAXON CELLS/ML TAXDN I BACILLARICPHYTA BACILLAHIOPHYTA Aaterlonel la 7.7 Cyclotel U 3.6 Havicula 3.8 Fragllarla 68.9 Syneora 3.3 flsloalra 10. 3 Synedra 3.6 I CHLCROPHYTA CHLOROPKYTA Scenedesnua 30.3 Oocyatls 21.7 CHRYSCPHYTA I CflRYSDPHYTA Dtnoacron 442.7 DlnoOryon 61.7 Synur» 108.9 CRYPTOPHYTA Cryptoroonaa 38.5 CRYPTQPHYTA I Cryptoaonas 7.2 CYANOPKYTA CYANOPHYTA Aphanocapaa 231 OsclllatocU 500.5 AnaOaena 29.0 I Aphanocapaa 526.3 EUGLENOPHYTA Mlcrocyatla 399.3 Euglena 3.3 Tracholcmonaa 3.8 TOTAL 1241.4 I 1266.6 BACILLARIOPHYTA 87.1 TOTAL 6ACILLARIOPHYTA 15.4 CHLOROPHYTA 21.7 CHLOROPHYTA 30.8 CHRYSOPHYTA 170.6 I CHRYSOPHYTA 442.7 CRYPTOPHYTA 7.2 CYANOPHYTA 954.6 CRYPTOPHYTA 38.5 CYANOPKYTA 731.5 I 7.7 TAXQN UG/L EUCLENOPHYTA BACILLARICPHYTA TAXDN UG/L I Cyclatella 18. 1 Fragi laria 137.9 Melo3tra 26.1 BACILLARIOPHYTA Synedra 29.0 Asterlonella 5.3 CHLOROPHYTA Navlcula 19.2 I Synedra 30.8 OocysCla 65.3 CHLOROPHYTA CHRYSQPHYTA - Scenedeanus 3.0 DSnoOryon 185.1 I Synura 217.8 CHRYSOPHYTA 1328.2 CRYPTOPHYTA Dlnobryon Cryptonnnas 7.2 CRYPTOPHYTA I CYANOPHYTA CrypComonas 38.5 Anabaena 90.0 CYANOPHYTA Aphanocapaa 5.2 Hlcrocyatla 3.9 Aphanocapaa 6.9 Osclllatoria 10.0 I TOTAL 786.0 EUGLENOPKYTA BAC1LURIQPHYTA 211.2 EuQlena 1.9 Trache 1 cmonaa 3.8 I CHLOTOPHYTA 65.3 CHRYSOPHYTA 402.9 TOTAL 1447.9 CRYPTOPKYTA 7.2 BACILLARIOPHYTA 55.4 I CTANOPHYTA 99.2 CHLOROPHYTA 3.0 CHRYSOPHYTA 1328.2 CRYPTOPHYTA 38.5 I CYANOPHYTA 16.9 EUGLENOPKYTA 5.7 I I I KP-3 Q;;588 KP-4 022539 K?-s az;sa8 I TAXCN CELLS/HL TAXCN CELLS/ML TAXON CILLS/'HL BACILURIQPHYTA BACILLARIQPHYTft CHHYSOPKYTA Aatericnel la 10.3 FraglUrU 44. 5 Dlnooryon 3.7 Cyc tote 1 !a H.5 Hsloaira 33. 6 Hal lemon a a 3.7 I frag liar la 47.1 Havlcula 2.9 Syneara 3.6 SurlrelU S.9 CRYPTCPHYTA SyneOr* 2.9 CHYPTOPHYTA Cryptccnonas 22.4 CSYPTOPKYTA Other cryptophyteg 108.4 Crypt emonaa 7.2 I Other cryptcphytes 14. S Crypt anon a s SO. 4 Other eryptophytes 44. S TOTAL 133. 3 CYANOPHYTA CYANOPKYTA CHRYSOPHYTA 7.4 Chrooeoccua 25. 4 I HlcrocyaCla 326.7 CRYPTOPHYTA 130.9 TOTAL 123.4 TOTAL 516.7 BACILLAR1QPHYTA 76.2 TAXON UG/L BACILLARIOPHYTA 95.0 I CRYPTOPKYTA 21.7 CHRYSQPHYTA CRYPTOPHYTA 95.0 CYANOPKYTA 25.4 DlnoDryon 11.2 CYANOPHYTA 326.7 Hal looionas i.a CRYPTOPHYTA I TAXON UG/L TAXON UG/L Cryptomonaa 35. S 8ACILLARIQPKYTA Other cryptophytea 108.4 BACILLARIOPHYTA Aaterlonella 7.S Cyclotella 36.3 FragllarU 13.3 TOTAL 157.0 I 11.5 Fragtlarla 94.3 Hsloalra 5 /near » 2.9 Kavicula 2.9 CHRYSOPKYTA 13.0 Surlrella 4158 CRYPTQPHYTA Synedra 2.3 CRYPTOPHYTA 143.9 I Cryptcmon*9 7.2 CRYPTOPHYTA Other cryptophytes 14.5 Crypt cmonas 50.4 CYAHOPHYTA Other cryptophytea 44.5 I Chroococcus 10.1 CYANOPHYTA Nlcrocyatls 3.2 TOTAL 173. t TOTAL 4286.6 I BACtLLABIOPHYTA 141.2 BACILLARIOPHYTA 41S8.2 CRYPTOPHYTA 21.7 CRYPTOPHYTA 95.0 CYAHOPHm 10.1 I , CYANOPHYTA 3.2 - I I I I I I I I KP-3 040488 KP-t 04C488 KP-5 0-10488 TAXCN CELLS/ML 7AXCS CELLS/ML TAXCH CEILS/HL BACILLAHIOPHYTA BACILLARIOPHYTA I BACILLABIOPHYTA Asterlcnel la 13.5 Cyclotella 12.7 Fragl larla 7.7 Cycloteila 38.4 Fragilarla 35.0 Syneara 30.8 Jragl larla 20,3 Gcmph enema 3.1 Tabellarla 38.5 Tabellarla 9,0 Synecra 9.5 I Tabel larla 12.7 CHLOROPHYTA CHLORQPHYTA CHLORCPHHA Scenedesnus IS. 4 Other green algae 4.5 Scentctesnua 12.7 CHRYSOPHYTA CHRYSOPHYTA I CHRYSOPHYTA Dlnobryon 2fl4.Q Dlnobryon •12.9 DlnoOryon 79.7 CRYPTOPHYTA C3YPTOPHYTA CRYPTOPHYTA Cryptanofiaa 261.9 Crypt etnonas 33,7 I Other crvptophytea 277.2 Other cryptophytes 122,0 Cryptcntonaa 204.1 Other cryptophytea 312.6 PYRRHOPHYTA TOTAL Z84.7 PYRRHCPHYTA Glenixiinium 7.7 I BACILLARIOPHYTA 81.3 Glenodlnlun 3.1 TOTAL 843.1 CHLOROPHYTA 4.5 TOTAL 685.8 BACILLARIOPHYTA 77 CHRYSOPHYTA «,9 BACILLARIOPKYTA 73.3 CHLOROPKYTA 15.4 I CRYPTOPfOTA 155.9 CHLOROPKYTA 12.7 CHRYSOPHYTA 204.0 CHRYSOPHYTA 79.7 CRYPTOPHYTA 539 TAXON UG/L I CSYPTOPHYTA SIS. 7 ' PYRRHOPHYTA 7.7 BACILLARIOPHYTA pyRRttOP«YTA 3.1 Aaterlonella -).4 Cyclotella 96.0 TAXON UG/L Fraqllarla 40.6 I Tabellarla 162.7 TAXOH UG/L BACILURICPHYTA C.HLOROPHYTA 2ACILLARICPHYTA FragliarU 15.4 Sfnedra 246.4 Other green alga* 4.5 Cyclotella 31.9 Tabel tar la S93 10.5 I F ragl larla CHRYSOPHYTA Gomphonema 10.2 CHLOROPHYTA Synedra 76.5 Dlnobryon 123.8 TaO«llarla 229.6 Scenedesnu3 23.1 CRYPTOPHYTA CULOSOPHYTA CHRYSOPHYTA I Crypt oraonaa 33.9 Scenedesmja 1.2 Dlnobryon 612.1 Other cryptophytes 122.0 CHRYSOPHYTA CRYPTOPKYTA TOTAL 598.2 DlnoOryon 239.2 Crypt otnonaa 288.7 I Other cryptophytes 277.2 BACILLARIOPHYTA 308.9 CRYPTOPHYTA PYRRHOPKYTA CHLCROPHYTA 4.5 Ccyptoroonas 226.4 Other cryptophytea 312.6 Glenodlnlum 137.0 CHRYSOPHYTA 129.8 I PYRRHOPHYTA CRYPTOPKYTA 1SS.9 TOTAL 2273.0 Glenodfnfuin 77.7 BACILLARIOPHYTA 954.8 I TOTAL 1218.2 CKLOROPHYTA 23.1 BACILLARIOPHYTA 3S8.8 CHRYSOPHYTA 612.1 CHLCROPHYTA 1.2 CSYPTOPHYTA 565.9 I CHRYSOPHYTA 239.2 PYRRHOPHYTA 137.0 CRYPTOPHYTA 539.1 PYRRHOPHYTA 79.7 I I I I I I TAXCN CZLLS^L TAXCN CSLLS/HL TAXCH cs:ia-«L 3ACILLARIOPHYTA BAC:iLAR!OPHYTA Agterlonel la 23.1 Astirlonel la 6.3 Aster lonei la 3C.3 Cyclctel U 61.5 Cccccneia 3.4 C/ciotel la 3.0 Synecra 3.8 Cyc!o;el la 3.4 Fragilaria TD.a I Cvrae 1 1 a 3.4 SvneoTa 3.0 CHSYSOPHYTA Fragilaria 30. 6 Taael larla 13.4 Navlcula 6.S Chrorajl Ina 3.3 lite i 1 ar i a 6.3 CHLCRCPHYTA Dlncorvon 92.4 Kalloncnaa 3.3 CKICSCPSYTA Hougeot la 27.7 I p-diaatrum 24.5 Other golden alc.ae 1193.5 Kougeot la 13.6 Scenecesnua 12.3 CSYPTCPHYTA Sceneaesnua 13. 6 CHBYSCPHYTA Crypt crccnaa 46.2 CHRYSOPHYTA I Dlnonryon 591.3 CYANOPfiYTft Dlnccryon 248.9 Other golden algae 748.4 Cther golden algae 521.7 Chroococcua 65. 4 CRYPTCPHYTA CaYPTDPHYTA PYRRHOPKYTA Cryptomonaa 77 I Cryptomonaa 71.6 Other cryptophytea 77 Glenodlnlum 3. a Other crypCopKytes 93.3 EUGLINCPHYTA PYRSHOPHYTA • TOTAt, 1497.6 Trachelomonaa 3.0 Glenodlnlum 3.4 I PYRRHOPHYTA BACILLARIOPHYTA 88.5 Glenodlnlum 3.0 CHHYSOPKYTA 1293.6 TOTAL 1033.2 C3YPTOPHYTA 46.2 BACILLARIOPHYTA 61.3 I TOTAL 1690.9 CHLOROPHYTA 27.2 CYANOPHYTA 65.4 BACILLARIOPHYTA 126.2 CHHYSOPKYTA 770.6 PYRRHOPHYTA 3. a CHLOROPHYTA 64.6 CSYPTCPKYTA 170.5 I CHRYSOPHYTA 1339.8 TAXCN UG/L PYRRHOPHYTA 3.4 CXYPTCPKYTA 1S4 3ACILLARIOPHYTA EUGLEMOPH^TA 3.0 Aaterlonella 16.1 TAXON UG/L I PYRRHOPHYTA 3.0 Cyclotella 154 Syneara 3.0 BACILLARICPKYTA CHRYSCPSYTA Aaterlonella 4.7 Cccconeia 3.4 TAXON UG/L I Chromul ina .7 Cyclotel la 6.5 BACILLARICPHYTA Dlnooryon 277.2 Cymtje 1 1 a 5.1 Hal lemon as 1.9 Fragt larla 61.3 Asterionella 21.5 Other sol den algae 595.7 Nfl vi cal a 34.1 Tabellarla 20.4 Cyclote! la 7.7 141.8 CRYPTOPHYTA Fragl iaria I CHLOROPHYTA Syneora 2.4 55.4 Cryptcmanas 59.6 Tabe 1 1 ar 1 a Houqeotla 214.1 QAHGPHYTA Sceneflesr.ua 20.4 CHLCROPHYTA 435.2 Chroococcus 26.1 CHRYSOPHYtA Kougeotla I Ped last run 4.9 Seenedeamua 1.2 PYRRHOPHYTA Dtnooryon 746.7 Other golden algae 260.8 Gienoolnlun 96.2 CHRYSOPHYTA CSYPTCPHYTA Dlnobryon 1774.0 I 374.2 TOTAL • • 1232 Cryptononas 95.4 Other golden alyae Other cryptophytea 98.8 BACILLARIOPKYTA 173.2 CRYPTOPHYTA PYRRHOPHYTA CHKYSQPSYTA 876.6 Cryptcmonas 77 I Glenodlnlua 36.1 Other cryptophytea 77 CRYPTOPHYTA 59.6 EOGLZNOPHYTA CYANOPKYTA 26.1 TOTAL 1610.5 Trache 1 omonas 46.2 PYRRHOPHYTA 96.2 BACILLARIOPHYTA 137.7 I PYRRHOPHYTA CHLQROPHYTA 234.6 Glenodlntum 32.6 CHRYSOPHYTA 1007.6 TOTAL 3051.3 194.3 I CSYPTOPKYTA BACILLARIOPHYTA 223.8 36.1 PYSRHOPHYTA CHt-QRCPHYTA 441.3 1 CHRYSOPHYTA 2148.3 I 154 CRYPTOPHYTA EUGLENOPKYTA 46.2 I PYRRHOPHYTA 32.6 I KP-3 050989 KP-4 05Q988 KP-S Qsa^ea TAXON :LLS/HL TAXCN C5LL5/HL TAXON CELL5/KL BACILLARIOPHYTA BACILLARICPHYTA flACILLARIOPHYTA Cyclotella 65.4 Aaterionel U 23.1 Asterlonel la 29.9 Synedra 3.8 Cyclotella 3.7 CHLOROPHYTA Synedra 11.2 CHLOROPHYTA Tabel larla 14.9 Cruel gen la 15.4 Cruel genU 15.4 Oocystls 11.5 CHLOROPHYTA Pedlaatrua 61.6 CHRYSOPKYTA Scenedesnug 46.2 Costnarlum 3.7 Stauraatrua 3.8 Cruel gen la 29.9 Blnobryon 315.7 Other green algae 30.8 Eudorlna 119.6 Klrchnerlel la 29.9 CSYPTOPHYTA CHRYSOPHYTA Mougeotla 33.6 Scenedesmua 14.9 Cryptomonas 30.8 Chromul Ina 3.8 Other cryptophytea 80.8 Dlnobryon 465.8 CHRYSOPHYTA CRYPTOPHYTA Chromullna 7.4 TOTAL 512.0 Dlnobryon 280.5 Crypt Oman as 77 ttatlaaanaa 7.4 BACILLARIOPHYTA 69.3 Other cryptophytea 89.5 CRYPTOPHYTA CHLOROPHYTA 15.4 TOTAL 827.7 Cryptomonas 48.6 CHRYSOPHYTA 315.7 Other cryptophytea 82.2 BACILLARIOPHYTA 23.1 CRYPTOPHYTA 111.6 CYANOPHYTA CHLOROPHYTA 169.4 Oaclllatorla 224.4 CHRYSOPHYTA 469.7 TAXON UG/L CRYPTOPHYTA 165.5 TOTAL 942.4 BACILLARIOPKYTA BACILLARrOPHYTA 59.8 CyclotelU 163.6 Synedra 3.0 TAXON UG/L CHLOROPHYTA 231.8 CHLOROPHYTA BACELLARIOPHYTA CHRYSOPHYTA 295.4 Cruel gen I a 1.5 Aaterionel la 16.1 CRYPTOPHYTA 130.9 CKRYSOPHYTA CHLGROPKYTA CYANOPHYTA 224.4 Dlnobryon 947.1 Cruel gen la 1.5 Oocystla 4.6 CRYPTOPHYTA Red last rum 55.4 TAXON UG/L Scenedesmua 4.6 Cryptoraonas 44.2 Staurastrum 46.2 BACILLARIOPHYTA Other cryptophytes 80.8 Other green algae 309 Asterlonel la 20.9 CHRYSOPHYTA Cyclotelta 9.3 TOTAL 1240.4 Synedra 89.7 Chromullna .7 Tabs 11 aria 269.2 BACILLARIOPHYTA 166.7 D I not) r yon 1397,5 CHLOROPHYTA CRYPTOPHYTA CHLOROPHYTA 1.5 Cosmarlun 29.9 2.9 CHRYSOPHYTA 947.1 Crypt anon a 9 90.4 Cruel gen la Other cryptophytea 88.5 Eudorlna 1SS.5 Elrchnerlel la 5.9 CRYPTOPHYTA 125.1 Hougeotla 528.4 TOTAL 2013.9 Scenedeamus 1.4 BACILLARIOPHYTA 16.1 CHRYSOPHYTA CHLOROPHYTA 420.4 Chromul Ina 1.4 Dtnobcyon 841.5 CHRYSOPHYTA 1398.3 MaJlomonas 3.7 CHYPTOPHYTA 179.0 CRYPTOPHYTA Cryptomonaa 48.6 Other cryptophyteg 82.2 CYANOPHYTA Oscillator la 44.8 TOTAL 2136.2 BACILLARIOPHYTA 389.3 CHLOROPHYTA 724.4 I - CHRYSOPHYTA 846.7 CRYPTOPHYTA 130.9 CYANOPHYTA 44.8 I I I ( l.s'-s ij^^^io J ---- — KP-3 051338 KP-4 C5Z2S3 C£LL£.'"L TAXON CELLS/ML TAXCJJ CiLLSHL TAXDN BACILLARIOPHYTA I BACILLARIOPHYTA BACULARICPHYTA 11.3 Agterlonei la 7.2 CvclOteMa a.i Cyclotel la Cyclotella lai.s Fragi larla 9.1 CHLORQPHYTA Fragl larU 39.9 Tabe Maria 32.5 Synedra 3.6 I Eudorina 3S4.3 CKC.C5CPKYT?, CHLQROPHYTA OocysUa 31.6 Eudorina 32.5 CHRYSOPHYTA Eudor I na 203.2 Oocystla IS. 2 Staurastruia 4.0 11.3 CHRYSOPHYTA Chromul Ina 427.6 CHRYSCPHYTA Other golden algae Dlnobryon '10.3 Synura 58. 0 Chronul Ina 4.0 CRYPTOPKYTA 130.2 Synura Crypt omonaa 257.4 CSYPTQPHYTA Other golden algae 252.3 Other cryptophyles 132.1 Crypt croon as 90.7 CHYPTOPHYTA Other cryptophytea 43.5 PYRRHOPHYTA Cryptonnnaa 166.8 3.9 CYANOPHYTA Other cryptophytea 113.9 Perldlnlura Anabaena 79.9 CYANOPHYTA TOTAL 1290.9 Anaba«na 69.1 TOTAL 718.7 BACILLARIOPHYTA 11.8 PYRRHOPKYTA 8ACILLARIOPHYTA 232.3 CHLOROPHYTA 396 Csratlura 4.Q CHRYSOPHYTA 439.5 CHLOROPHYTA 203.2 Glenodlnlun 4.0 439.5 CHRYSOPHYTA 68.9 CRYPTOPHYTA 846.5 TOTAL 3.9 CRYPTOPHYTA 134.3 PYRRHOPHYTA BACILLAHIOPHYTA 48. S CYANOPHYTA 79.8 CHLOROPHYTA 52.9 TAXON UG/L TAXOH VG/L CHRYSOPHYTA 386.6 BACILLAHIOPHYTA BACILLARIOPHYTA CRYPTOPHYTA 230. 3 Cyelote! la 29.7 Asterlone) la 5.0 CYANOPHYTA 69.1 Cyclotella 453.7 CHLOROPHYTA Fragl larla 79.8 PYRRHOPHYTA 8.1 Synedra 29.0 Eudorina 473.6 Oocyatis 12.6 CHLOfiOPHYTA CHRYSOPHYTA TAXOH UG/L £udor I na 264.2 Chremul Ina it. a BACILLARIOPHYTA CHRYSOPHYTA Other golden algae 427.6 Cyclotella 20.3 CRYPTOPHYTA Dlnobryon 163.3 Fragllaria 16.2 Synura 116.1 < Tabellarla 586.0 Cryptomonas 257.4 Other cryptophytes 1S2.1 CRYPTOPHYTA CHLOROPHYTA PYRRHOPHYTA CryptoRtonas 90.7 Eudorina 42.3 Other cryptophytes 43.5 Oocystla 6.5 Perldlnlum 178.2 Staurastrum 48. 8 CYANOPHYTA CHRYSOPHYTA Anabaena 247.5 TOTAL 1573.3 4.0 Chromul Ina BACILLARIOPHYTA 29.7 Synura 250.4 TOTAL 1493.3 Other golden aigae 252.3 CHLOROPHYTA 486.2 BACILLARIOPHYTA 567.7 CRYPTOPHYTA CHRYSOPHYTA 439.5 CHLOROPHYTA 264.2 Cryptomonas 166.8 CSYPTOPHYTA 439.5 Other cryptophytes 113.9 CHRYSOPHYTA 279.5 PYRRHOPHYTA 178.2 CYANOPHYTA CRYPTOPHYTA 134.3 Anabaena 303.6 CYANOPHYTA 247.5 PYRRHOPHYTA Ceratlum 976.8 Clenodlnlum 43.1 TOTAL 2841.6 BACILLARIOPHYTA 622.7 CHLOROPHYTA 97.6 CHRYSOPHYTA 516.8 CRYPTOPHYTA 280.8 CYANOPHYTA 303.6 PYRRHOPHYTA 1019.9 •).(•- J vou^ca } V _^ TAXCSI —~~^*^ \x*m^^ CELLS/ HL 7AXCH— -"^ CSLLS/ KL CELLS, .^i. 3ACILURIOPHYTA BACILLARIGPHYTA 3ACILU3lCPtTi7A I Asterlonei la Asterlonel la 10.3 Cyciotel la 75.0 133.3 C/clotella Cyclotella 566.2 Fraqi larli 30.6 30.3 Fragi larla S3.-I Mavicula 3.4 NavlcuU 3.6 CHLOROPHYTA CHICROPH^TA AnldstrocJesnjus 25.? I CHLOROPHYTA Anklscroflssraua 3. A Oocystla 23.1 EuCortna 27.2 Eudorlna 58.0 CHRYSOPHYTA Qocystla 21.7 Ouaorigula 27.2 Quadrlgula 43. S Sceneaesnus 13.6 Dlnooryon 1153.3 I CKRYSOPHYTA CHRYSOPHYTA CRYPTOPHYTA Chrorcul in* 25. < Dlnotiryon 262.5 Cryptomonas 96.2 Other cryptophytes 60. 8 CRYPTOPHYTA CRYPTOPHYTA I CYANOPHYTA Crypt omonas 18. 1 CCYptaaoats 92.0 Other cryptophytes 71.6 Anabaena 88.5 CYANOPHYTA CYANOPHYTA Chroococcua 92.4 AnaOaena 68.9 Anabaena 37. S EUGLENOPHYTA I Oaci 1 latorla 762.3 Chroococcus 54,5 Trachelcmonas 15. 4 1662.5 PYRRHOPHYTA TOTAL PYRRHOPHYTA Ceratlum 3.4 664.2 BACILLARIOPHYTA 3.3 I Ceratlum CHLOROPKYTA 123. < TOTAL 702.4 TOTAL 1747.9 CHRYSOPHYTA 25.4 BACILLARIOPHYTA 109.1 BACILLARIOPHYTA [61.7 CRYPTQPHYTA 18,1 I CtiLOROPHYTA 71.6 CHLOROPHYTA 50.0 CYANOPHYTA 831.2 CHRYSOPHYTA 262.5 CHRYSOPHYTA 1158.3 CRYPTOPHYTA 163.6 CRYPTOPHYTA 177.1 I TAXON UG/L CYANOPHYTA 92.0 CYANOPHYTA 180.9 SACILLABIOPHYTA PYERHOPKYTA 3.4 EUGCCfJOPKYTA 15.4 Asterlonella 7.6 PYRRHOPHYTA 3.8 CycloteMa MIS. 7 I Fragi larU 166.9 TAXOH UG/l Navlcula 3.6 TAXOH UG/L BACILLARIOPHYTA BAClLLASlOPWfTf, CHLORQPKYTA • Aster lone Ma 9{.fi CyclotelU 187.5 Eudorlna 75.5 Cyclotella 77 I Oocyst Is 8.7 FraglUrU 61.3 Ouadrlguia 8.7 Kavlcula 3.4 CHLOROPHYTA CHLOROPHYTA CHRYSOPHYTA Ankl strode smus 13.4 Oocyatls 9.2 Ankistrodeanua 1.7 I ChrcmuUna 5,0 Eudor 1 na 35.4 CHRYSOPHYTA CRYPTOPHYTA Ouidrlgula 5.4 Scenedesnua 20.4 Dlnobryon 3476. S Crypt ornon« 18.1 CHRYSOPHYTA CRYPTOPHYTA I CYANOPHVTA D 1 noOryon 787.7 Cryptomonaa 96.2 Anabaena 213.8 Other cryptophytes BO. 3 Osclllatorla 15.2 CflYPTOPHYTA CYANOPHYTA Crypt oownas 139.8 I TOTAL 1939.1 Other cryptophytes 71.6 Anabaena 274.5 Chrooccxrcua 36.9 BACILLARIOPHYTA 1593.9 CYANOPHYTA EUCCEWOPHYTA Anabaen* 116.2 CHCOROPtfyTA 92.? Chroococcua .5 Trache 1 omonaa 31. 6 I CHRYSOPHYTA 5.0 PYRRHQPHYTA PYRRHOPHYTA CRYPTOPKYTA 18.1 Cera t Sum 818.4 Ceratlum 924 CYAHOPHVTA 229.0 5162.0 I TOTAL TOTAL 2249.7 BACILURIOPHYTA 163.6 BACILURIOPHYTA 252.3 CHLORQPHYTA 22.7 CHLOROPHYTA 63.0 I CHRYSOPHYTA 3476,5 CHRYSOPHYTA 787.7 CRYPTOPHYTA 177.1 CSYPTOPHYTA 211. 4 CYANOPHYTA 311.4 CYAHOPHYTA 116.8 I HKTLEHOPHYTA 51.5 PYRRHOPHYTA 816.4 PYRRHOPHYTA 924 I I \F-J :d;aaa ' 062Z-B5 KP-5 oozcaa TAXCN CELLS' KL TAXON C;LLS/.U TAXCN CILLS/ML I BACILLARIOPHYTA BACILLARIOPHYTA BACILLARIOPHYTA Agcenonel U -(7.1 CyeloteUa 10.8 Crclotella 8.! Cvclotella 736.9 Heloslra 29.1 Fragi Una 232.3 CHLOROPHYTA I PI euros i^na 3.6 CHLOROPHYTA Cosnar 1 un 3.6 CHLOEOPHYTA Sceneaesmua 14.5 Eudonna 65.1 Ogaarigula 53.0 CBYPTOPSYTA CRYPTOPHYTA I CfiRYSQPHYTA Cryptomonas 170. S Cryptononas 248.2 Other cryptcphytes 138.7 Other cryptophytea 187.2 Dinooryon 90.7 PYRRHCPHYTA CYANOPHYTA CRYPTQPHYTA I Ceratlum 10.8 Chroococcus 89.5 Cryptononas 43.5 PYRRHOPHYTA CYANOPHYTA TOTAL 399.3 Glenodinlum 4.0 Anabaena 47.1 BACILLARIOPHnA 10.8 I Qiroococcua so. a CHLOROPHYTA 18.1 TOTAL 630.8 PYRRHOPHYTA CRYPTOPHYTA 359.3 BACILLARIOPHYTA 36.6 Ceratlum 3.6 I PYRRHOPHYTA 10.8 CHLOROPHYTA $5.1 TOTAL 13H.O CRYPTOPHYTA 43S.4 BACILLARIOPHYTA 1020.0 TAXON UG/L CYANOPHYTA 89.5 I CHLOROPHYTA 58.0 BACILLARIOPHYTA PYRRHOPHYTA 4.0 CHRYSOPHYTA 90.7 CyclotelU 27.2 CRYPTOPHYTA «.S CHLOROPHYTA TAXON UG/L I CYANOPHYTA 98.0 Cosflwrlura 29.0 BACILLARIOPHYTA Scenedeaniua 1.4 PYRRHOPHYTA 3.6 Cyclotel la 20.3 CRYPTOPHYTA Heloslra 68,3 Cryptcxnonaa 170.6 CHLOROPHYTA I TAXON UG/L Other cryptophytes 186.7 Eudorlna 84.6 BACILLAHIOPHYTA PYRRHOPHYTA CRYPTOPHYTA Aatertonella 33.0 Cera ti urn 2S13.S CrelotelU 1342.2 Cr yp Ccmonaa 248.2 I 187.2 Fragilarla 464.6 Other cryptophytes PI euros Igna 11.6 TOTAL 3030.6 CYftNOPHYTA CHLOROPHYTA BACILLARIOPHYTA 27.2 Chroococcus 35. 8 I Quaorigula 11. 6 CHLOROPHYTA " 30.4 PYRRHOPHYTA CKRYSOPHYTA CRYPTOPHYTA 359.3 Glenodlnlum 43.1 OlnoOryon 272.2 PYRRHOPHYTA 2SI3.6 I CRYFTOPKYTA TOTAL 687.8 Crypt omonaa 43.5 BACILLARIOPHYTA 88.7 CfANOPHYTA CHLOROPHYTA 84 .5 I CRYPTOPHYTA 435.4 Anaoaena 146.2 Chroococcus 20.3 CYANOPHYTA 35.3 PYRRHOPHYTA PYRRHOPHYTA 43.1 I Ceratlum 871.2 TOTAL 3716.7 I BACILLARIOPHYTA 23S1.S CHLOROPHYTA 11.6 CHRYSOPHYTA 272.2 I CRYPTOPHYTA 43.5 CYANOPHYTA 166.5 I PYRRHOPHYTA 971.2 I I : CRYPTOPHYTA 45.9 TAXQN UG/L TAXON UG/L CYANOPHYTA 434.7 I BACILLARIOPHYTA BACILLARIOPHYTA PYRRHOPHYTA 20.? Asterionel la 9. S Cyelot*l la 536. 8 Asterionel la 5.6 Frag! larla 63.3 Cyclotella 10.1 Synedra 3.2 TAXON UG/L I CHLOROPKYTA CHLOROPHYTA BACILLARIOPHYTA Scenedesrnus 1.4 Other green algae 337.9 Scenedesmug 1.6 Aaterlone! la 8.7 Synedra 6.6 I CRYPTOPHYTA CHRYSOPHYTA CHLOROPHYTA Other cryptophytea 45. 7 Dlnobryon ini.i Anki strodesmua 2.0 Eudorlna 86.9 CYAHOPHYTA CRYPTOPHYTA I Aphanocapsa 13.9 Cryptomonaa 56.9 CHRYSOPHYTA Chroococcua 2.2 Other cryptophytes 28.4 Chrccnul Ina 1.6 PYRRHOPHYTA PYRRHOPHYTA Dlnobryon 9154.2 Ceratlum 2534. 4 Cera C 1 \aa 293(3.4 CRYPTOPHYTA I Glenodlniuin 86.2 Perldlnlum 366.3 Cryptomonaa 45.9 TOTAL 3S4S.fi CYANOPHYTA BACILLAHIOPHYTA 610.0 TOTAL 4600.3 Her 1 smoped 1 a 53.5 I 3.3 CHLOROPHYTA 339.3 BACILLARIOPHYTA 19.1 Oaclllataria PYRRHOPHYTA CRYPTOPHHA 45.7 CHLOROPHYTA 1.6 Cerattum 2006.4 CYAKOPKYTA 16.1 CHRYSOPHYTA 1111.1 Clenodlnlura 132.9 I PYRRHOPHYTA 2534.4 CRYPTOPHYTA 85.4 PYRRHOPHYTA 3382.? TOTAL 11502. S BACILLARIOPHYTA 15.4 I CHLOROPHYTA 89.0 CHRYSOPHYTA 9155.8 CRYPTOPHYTA 45.9 I CYANOPKYTA 56.8 PYRRHOPHYTA 2139-3 I I I TAXCH " CELLS/HL TAXCN " CELLS/ML TAXCN ^ •-"""CELLS-1 "L I BACJLUHJQPHYTA aACILLARIOPKYTA CHLOROPHYTA Cyclotella 8.3 FraglUria 24.4 Ankiatroaesmua 3.4 Fragi larta 37. S Eucorlna 245.5 Syneora 4.1 CHLOSCPHYTA Other green algae 27.2 I CHLOBOPHYTA Scsnetiesmus 16.2 CHRYSCPHYTA Cocystls 16.7 CHRYSOPHYTA Chrcmul Ina 23.8 Dinooryon 44.3 CHRYSOPKYTA DlnoOryon 36.6 CSYPTOPWyTA I ChronuUna 4.1 CRYPTDPHYTA Dinoaryon 62,7 Crypt cmonas 20.4 Cryptomonag 16.2 CRYPTOPHYTA CYANOPHYTA CYANOPHYTA Crypt Down a 3 20.9 / ~~\ Aphanothece 231.3 I Aphanothece .U 953. 63 Chroococcus 313.7 CYANOPHYTA Chroococcug 97.6 Merianopedl* 130.2 PYRRHOPHYTA AnaDaena 25. 0 Klcrocygtla 447.7 Chroococcua 33. 4 Ceratlum 3.4 I Merlsmopedla 585. 2 PYRSHOPHYTA Gtenodlnlun 3.4 Hlcrocystls 376.2 PhormlQlum 317.6 Cera Ci urn 12.2 Glenodlnlun 12,2 TOTAL 917.2 PYRRHOPHYTA CHLOROPHYTA 276.2 I Cera tl am 8,3 TOTAL 2747.2 Clenodlnlum 12.5 CHRYSOPHYTA 68.2 BACILURIOPHYTA 24.4 CRYPTOPHYTA 20.4 TOTAE, tStJ.l CHLOSOPHYTA 16-2 CYANOPHYTA S4S.6 I CHRYSOPKYTA 36-6 BACILLARIOPKYTA 50.1 PYRRHOPHYTA 6.8 CHLOROPHYTA 16.7 CRYPTOPHYTA [6.2 CHRYSOPHYTA S6.3 CYANOPHYTA <^27.2') I TAXON UG/L CRYPTOPHYTA 20.9 PYRRHOPHYTA 24-4 CHLOROPHYTA CYANOPHYTA 1337.6 Anklstrodesmus 1.7 PYRRHOPHYTA 20.9 TAXCN UC/L Eudorlna 319.1 I Other green algae 272.8 BACILLARIOPHYTA CHRYSOPHYTA 7AXOH VG/L Ffagilarla 7.3 Chrotnul Ina 4.7 I BAC1LLARIOPHYTA CHLOROPHYTA Dlnobryon 132.9 Cyclotella 20.9 SceneCesmus 1.6 CRYPTOPHYTA Fragllaria 75. 2 Syne or a 33.4 CHRYSOPHYTA Cryptomonas 20.4 I CHLOROPHYTA Dlnobryon 109.8 CYANOPHYTA Oocystls 50.1 CRYPTOPHYTA Aphanothece 6.9 Chrcococcua 3.1 CHRYSOPHYTA CrypComonaa 16.2 PYRRHOPHYTA 1 ChromuMfla .8 CYANOPHYTA D 1 nooryon 188.1 Ceratlun eta. 4 Aphanothece 53.6 Glenodlnluni 10.2 CRYPTOPHYTA Chroococcus 39,0 Her ianopedla 26. 0 I Cryptomonas 20.9 Mlcrocyatla 4.4 TOTAL 1S90.6 CYANOPHYTA PYRRHOPHYTA CHLOROPHYTA 593. S Anabaena 77.7 Ceratiun 2930.4 CHRYSOPHYTA 137.7 Chroococcus 13.3 Glenodlnlum 67.5 I Herlsmopedla . 117.0 CRYPTOPHYTA 20.4 Mlcrocyatla 3.7 Phonnldlun 6.3 TOTAL 3261.2 CYANOPHYTA 10. 0 PYRRHOPHYTA BACILLARIOPHYTA 7.3 PYRRHOPHYTA 828.6 I Ceratlun 2006.4 CHLOROPHYTA 1.6 Glenodlnlun 132.9 CSRYSOPHYTA 109.8 TOTAL 2747.1 CRYPTOPHYTA 16.2 I BACILLARIOPKYTA 129.5 CYAHOPHYTA 128.2 CHLOROPHYTA 50. 1 PyRRHOPHYTA 2977.7 I CHRYSOPHYTA 188.9 CRYPTOPHYTA 20.9 CYANOPHYTA 218.2 I PYHRHOPHYTA 2139.3 I 7AXCN CELLS/fIL TAXCN CELLS'^ TAX CM CiLLS'HL BACtLLARlOPHYTA BACILLARIQPHYTA BACILURIOPHYTA MHoaira 31.6 I Fragi larla 71.6 Cyclotella 4.0 Syneflra 3.4 CHLCROPHYTA CHLOROPHYTA CHRYSOPHYTA Anxiatrodesmua •1.0 Anktatrodesnua 3.5 Dinobryon 102.3 Cuoorlna 130.2 Eu dor Ina 34. -S I Stauraatrum 7.0 CYANOPHYTA CHRYSOPHYTA CHRYSOPHYTA Aphanocapaa /3171.3 \ Chrcnul Ina 4.0 Dl noCryon 77.4 Chroococcua / 709.2 Dinobryon 28.4 Hal lemon as 3.5 I Hlcrocyatla / 1790.2 / Oscillatorla 180.7 / CSYPTOPKYTA CRYPTOPHYTA Phonal dlum V.122.7 / Cryptomonaa 32. S Crypt omonaa 42.2 PYRRHOPHYTA CYANOPHYTA CYANOPHYTA i Ceratluro 6.8 ~- Aphanothecs /'480.2>. Anabaena 193. S" Chroococcua ' 284.9 ) r 95.0 ~> Chroococcus V — 1 1 TOTAL Klcrocystls 488.4 / HlcrocyatlS \ 492.8^, ("----_'—- s BACILLARIOPHYTA 7S.Q PYRRHOPHYTA EUGLENOPHYTA i CHRYSOPHYTA 102.3 Glenodtnlum 16.2 Tr ache 1 omonaa 7.0 CYANOPHYTA 5974.3 PYRRHOPHYTA TOTAL f^ —1473.3 - \ ^~_ ^ Gl tnodlnlum 7.0 i PYRRHOPHYTA 6.8 BACILLARIOPHYTA 4.0 TOTAL (/1045.4-- 134.3 CHLOROPHYTA SACILUfflOPHYTA 31.6 TAXON UG/L CHRYSOPHYTA 32.5 CHLOROPHYTA 95.0 i BACILLARIOPHYTA CRYPTOPHYTA 32.5 CHRYSOPHYTA 80.9 Fragi larla 143.2 CYANOPHYTA 1253.5 Synedra 2.7 CRYPTOPHYTA 42.2 CHRYSOPHYTA PYRRHOPHYTA 16.2 781.4 i CYANOPHYTA Dinobryon 306.9 EUGLEHOPKYTA 7.0 TAXON UG/L CYANOPHYTA PYSRHOPHYTA 7.0 Aphanocapaa 95.1 BACILLAHIOPHYTA i TAXON UG/L Chroococcua 7.0 10. 1 Mlcrocyatla 17.9 Cyclotella BACILURIOPHYTA QacM latorla 3.6 CHLOROPHYTA Phorraidlura 2.4 Meioalra 9.5 i Anklatrodesmus 2.0 PYRRHOPHYTA CHLOROPHYTA Eudorlna 169.3 Cera t i urn 1636.8 Ankiatrodesmua 1.7 CHRYSOPHYTA Eudorlna 109.8 Staurastrum 84.4 TOTAL 2215.8 Chromullna .4 i Dinooryon 85.4 CHRYSOPHYTA BACILLARIOPHYTA 145.9 CSYPTOPKYTA Dinobryon 232.3 CHRYSOPHYTA 306.9 Hal lomonaS 14.0 Crypt omonaa 32. S i CYANOPHYTA 126.2 CYANOPHYTA CRYPTOPHYTA PYRRHOPHYTA 1636.8 Aphanothece 96.0 Crypt oman as 42.2 Chroococcua 113.9 Mlcrocyatla 4.8 CYANOPHYTA i 77.4 PYRRHCPHYTA Anabaena Chroococcus 38.0 28.3 Glenodlnlum 48.8 Mlcrocystla EUGLENOPHYTA i TOTAL 563.6 Trachelomonas 37.3 BACELLARIOPHYTA 10.1 PYRRHOPHYTA CHLOROPHYTA 171.3 Glenotilnlun 74.6 i CHRYSOPHYTA as. a" TOTAL 749.9 CRYPTOPHYTA 32.5 BACILLARIOPHYTA 9.5 CYANOPHYTA 214.8 CHLOflOPHYTA 196.0 i PYRRHOPHYTA 48.3 CHHYSOPHYTA 246.4 CRYPTOPHYTA 42.2 CYANOPHYTA 143.7 i EUGLENOPHYTA 37.3 PYRRHOPHYTA 74.6 i i TAXCN CELLS/ HL TAXCN CELLS/ML TAXON CELLS/ fIL I BACILLARIOPHYTA CRYPTCPHYTA BACILLARIOPHYTA Fragi Uria 85.4 Cryptocnonas 94.3 Gyrogj^a 3.S Other cryptophytes 39.9 Melosira 36.3 CHLOROPHYTA Other diatoms 10. 8 CYANOPHYTA f Ouadr iguia 48.8 CHLOROPHYTA Hicrocygtis 12S2.3 CHRYSOPHYTA Ankistrodesmus 3.6 EUGLE.10PHYTA Dlnoorycn 101.7 CHRYSOPHYTA I Trachs 1 omonas 3.6 CRYPTOPHYTA Chrcmui ina 3.6 PYSRHOPHYTA Cryptonionag 44.7 CRYPTOPHYTA Glenodlnium 3.6 I CYANOPHYTA Cryptomonas 112.5 sr ~^ Aphanocapsa \ TOTAL 1393.9 CYANOPHYTA Chroococcug { 675.6 Mlcrocygtlg \ 1465.2 ,' CRYPTOPHYTA 134.3 Anabaena 94.3 Phormidiura V 48.8 / Chroococcus 163.3 1 \^^y CYAHOPHYTA 1252.3 Hlcrocystls 308.5 TOTAL {^4546.1 EUGLENOPHYTA 3.6 EUGLENOPHYTA BACILLARIOPHYTA 85.4 PYRRHOPHYTA 3.6 Phacug 7.2 Trachelomonas 3.6 i CHLOROPHYTA 48.8 PYRRHOPHYTA CHRYSOPHYTA 101.7 TAXON UG/L Glenodinlum 3.6 CRYPTOPHYTA 44.7 CRYPTOPHYTA TOTAL 751.4 CYAHOPHYTA i 4265.3 Cryptomonas 94.3 BACILLARIOPHYTA 50.8 Other cryptophytss 39.9 CYANOPHYTA CHLOPOPHyTA 3.6 TAXON UG/L CHRYSOPHYTA 3.6 Mlcrocystia 12.5 i BACILLARIOPHYTA EUGLENOPHYTA CRYPTOPHYTA 112.5 Fragi 1 aria 170.9 566.2 Trachelononag 3.6 CYANOPHYTA CHLOSOPHYTA i PYRRHOPHYTA EUGLENOPHYTA 10.8 Ouadr 1 gu 1 a 9.7 PYRRHOPHYTA 3.6 Glenodlnium 10.8 CHRYSOPHYTA TAXON UG/L Dlnooryon 305.2 TOTAL 161.3 i BACILLARIOPHYTA CRYPTOPHYTA CRYPTOPHYTA 134.3 Gyros ioma 25.4 44.7 87.1 Cryptcmonaa CYANOPHYTA 12.5 Melosira Other aiatoms 103.9 CYANOPHYTA EUGLENOPHYTA 3.6 i CHLOROPHYTA Aphanocapsa 62.2 PYRRHOPHYTA 10.8 Chroococcus 92.4 Ankistrodesmus 1.8 Mlcrocystls 14.6 i Phormidium .9 CHRYSOPHYTA Chromul Ina 3.6 TOTAL 701.0 CRYPTOPHYTA BACILLARICPHYTA 170.9 Cryptomonas 112. 5 i CHLDROPHYTA 9.7 CYANOPHYTA CHRYSOPHYTA 305.2 Anabaena 292.5 CRYPTOPHYTA 44.7 Chroococcus IB. 6 MicrocyaCis 3.0 i CYANOPHYTA 170.3 EUGLENOPHYTA Phacus 21.7 i Trachelomonas •19.2 PYRRHOPHYTA Glenodlnium 10.8 i TOTAL 705.5 BACILLARIOPHYTA 221.4 CHLOROPHYTA 1.8 i CHRYSOPHYTA 3.6 CRYPTOPHYTA 112.5 CYANOPHVTA 314.2 i aiGLENOPHYTA 41.0 i PYRRHOPHYTA 10.8 TAXCN CELLS/ML TAXCN Ctll^l TAXON CELLS XI MCIIUWOPH™ SACILURrCPHYTA BACILLAfltOPKm I Asterlonella 11.3 Syreara 3.9 Tabel Url4 3.6 frag! I aria 106.9 TaDel laria 7.9 CHLOROPHYTA CHLOSCPHYTA CHCCROPHYTA Anklstrodesnua 7.2 Quadrlgula 3t.6 Scenedesmus 15.8 Eudorlna 14.5 i Pedlaatrun 58.0 CHRYSOPKYTA CHRYSOPHYTA Dlnobryon 23.7 Olnobryon 257.4 Chrcmul Ina 10.3 CRYPTOPHYTA CRYPTOPHYTA Dlnobryon 21.7 i Cryptonwaa 7S.2 CcYptomonts 39.5 CRYPTOPHYTA Other cryptophytes 51.4 Other cryptophytea 19.8 Cryptomonas 65.3 CYANOPHYTA i TOTAL 344.5 CYANOPHYTA Aphanoc-apsa 3405.5 Chroococcua 91.0 BACILLARIOPHYTA 11.8 Aphanocapaa 163.3 Hlcrocystla 435.6 Chroococcua 65.3 Phamidlun 55.4 CHLOROPHYTA IS. 8 Herlamopedla 58.0 Htcrocrstls 272.2 i EUGL2NOPBYTA CfffiySOPHYTA 257.4 EUGLENOPHYTA Trachelcmonaa 11. 8 CRYPTOPHYTA 59.4 Phacua 3.6 Trachelononaa 10.3 TOTH 4300.5 i TAXOH UG/L BACILLARIOPHYTA 118. 8 TOTAL 755.0 BACILLAHIOPHYTA CHLOROPHYTA 31.6 BACILLARIOPHYTA 3.6 Synedra 178.2 i CHRYSOPKYTA 23.7 Tab* Maria 23.7 CHLORCPKYTA 79.8 CRYPTQPHYTA 126.7 CHLOROPHYTA CHRYSOPHYTA 32.6 CYANDPHY7A 3987.7 Sc^dM^s J.S CRYPTOPHYTA 65.3 i EUGLENOPHYTA 11. 8 CHRYSOPHYTA CYANOPHYTA 559.0 Dlnobryon 772.2 EUGLENOPHYTA 14.5 TAXON UG/L CRYPTQPHYTA i BACILLARIOPHYTA Cryptomonaa 39.6 TAXON UG/L Other cryptophytea 19.3 Asterlonel la 8.3 BACILLAR1QPHYTA Fragl 1 art a 213.8 TOTAL 1035.1 Tibet larU 65.3 i CHLQGOPHYTA BACILLARIOPHYTA 201.9 CHLOROPHYTA Quadrlgula 6.3 CHLOROPHYTA 1.5 Anklatrodesmua 3.5 CHRYSOPKYTA Eudorlna 18.8 CHRYSOPHYTA 772.2 Fed L 13 1 rum 11.6 i Olnooryon 71.2 CHY?TOPHYTA 59.4 CHRYSOPHYTA CRYPTOPHYTA Chrccnul Ina 10.8 Cryptononaa 75.2 Dlnobryon 65.3 Other cryptophytea 51.4 i CRYPTOPHYTA CYANOPHYTA Cryptomonaa 65.3 Aphanocapaa 102.1 Chroococcus 36.4 CYANOPHYTA i Mlcrocystls 4.3 Phornldlum 1.1 Aphanocapsa 4.9 Chroococcus 26.1 EUGLEHQPHYTA Kerlsmopetjla 11.6 Hlcrocyatis a. i Trachelomonaa - 11.8 • i EUGLEHOPHYTA TOTAL 582.4 Phacua . 10.8 Trache 1 omonaa 10.8 BACILLARIOPHYTA 222.1 i CHLOROPHYTA 6.3 TOTAL 313. S CHRYSOPKYTA 71.2 BACILLARIOPHYTA 65.3 CSyPTOPHYTA 125.7 CHLOfiOPHYTA 34.1 i CYANOPHYTA 144.0 CHRYSOPHYTA 76.2 EUGLENOeHYT* 11.8 CRYPTOPHYTA 65.3 CYANOPHYTA 50,8 i EUGLENOPHYTA 21.7 i i I Knopp's Pond Zooplankton. KNOPF'S POND 050988 KNOPF'S PCHD 071988 TAXON «/L TAXON I ROTIFERA ROTIFERA tCellicoUla .8 Asplanchna 1.7 Keratel la .5 I COPEPODA Polyarthra .3 Mesocyclops 1.6 COPEPODA Dl apterous 4.1 Epischura .2 Mesocyclops 3-0 Naup I L I 4.7 CUaptomus 1.8 I Nauplll 1.7 CLADOCERA CLADOCERA Ceriodaphnia .5 Daphnia amblgua 1.3 Ceriodaphnia 1.0 I Daphnia galeata 1.1 Daphnia amblgua 3.0 Dlaphanosoma .3 Daphnia galeata 3.3 EuOosmlna 6.4 Dlaphanosoma 1.2 Slda .2 TOTAL 21.4 TOTAL 18.1 I ROTIFERA .8 ROTIFERA 2.5 COPEPODA 10.7 COPEPODA 6.5 CLADOCERA 9.8 I CLADOCERA 8.9 TAXON UG/L I TAXON UG/L ROTIFEHA ROTIFERA Sell Icottla .1 Asplanchna 1.7 i COPEPODA Keratel la .1 Polyarthra .1 Mesocyclops 2.1 DlapEcmug 1.9 COPEPOOA Epischura 3.4 i Nauplll 12.4 Heaocyclops 3.7 Diaptomus .8 CLADOCERA Naup 1 1 i 4.5 Ceriodaphnia 1.3 CLADOCERA Daphnia amOigua 2.1 i Daphnia galeata 6.8 Ceriodaphnia 2.8 Dlaphanosoma 2.4 Daphnia amOigua 4.8 Eubosmina 19.2 Daphnia galeata 19.4 Dlaphanosoma 8.2 i TOTAL 51.9 Sida 1.2 ROTIFERA .1 TOTAL 47.6 COPEPODA 19.9 ROTIFERA 1.8 i CLADOCERA 31.9 COPEPODA 9.2 i CLADOCERA 36.6 i i i i i Lost Lake Zooplankton. LOST LAKE 050988 LOST LAKE 071988 a/L. I TAXON s/l TAXOK ROTIFERA ROTIFERA Asplanchna .-1 Asplanchna 2.3 Kellicottla 4. a I Keratella .9 COPEPODA Polyacthra .5 ffffsocyclops 1.0 COPEPOOA Diaptomua 2.8 Hauplli .a I Hesocyclops 4.0 Dlaptomja .7 CLADOCERA Epischura .0 Naupilt 2.6 Cerlodaphnia .6 Chydorus ,3 l CLADOCERA Daphnla galeata .3 Diaphanosoma 1.0 Ceriodaphnla .4 ' Eubosmina iS.8 Chydorus .2 Leptodora .1 Daphnia amblgua .1 Sida .2 l Daphnla galeata .3 Diapbanosoma .1 TOTAL 2S.7 Eubosmlna 1.6 ROTIFERA 2.3 TOTAL 17.2 COPEPODA 4.7 I ROTIFERA 6.8 CLADOCERA 18.6 COPEPODA 7.1 CLADOCERA 2.9 l TAXON UG/L ROTIFERA TAXON UG/L l Asplanchna 2.3 ROTIFERA COPEFODA Asp ) anchna .4 Kelllcottla .1 Hesocyclops 1.3 1.3 l Kerateila .1 Diaptomus Polyarthra .1 Haufl 1 i 2.3 COPEPODA CLADOCERA Mesocyciops 5.0 Ceriodaphnla 1.6 l Diaptomus .3 Chydorus .3 Epischura 1.0 Daphnia galeata 2.0 Nauplll 6.9 Diaphanosoma 6.7 Eubosmina 47.2 CLADOCERA Leptodora 14.5 l SI da 1.2 Csriodaphnia 1.2 Chydorus .2 TOTAL 8t. I Daphnla amblgua .2 Daphnla galeata 1.8 ROTIFERA 2.3 Dlaphanosoma l .5 Eu&osmlna 5.0 COPEPODA 5.0 TOTAL 23.3 CLADOCERA 73.7 ROTIFERA .8 l COPEPQDA 13.4 CLADOCERA 9.1 l i l l l l I I I I I 3. Calculation Sheets and I Useful Conversions. i i i i i i i i i i i i I I HXDROLCGIC CALCULATIONS FOR LOST LAKE / KNAP'S PO3D. I 1.) Unit Watershed Area Mathod. a.) Watershed Areas (ha) : Unnamed tributary 141.6 Martin's Pond Brook 627.7 Direct drainage I via kettleholes 330.2 via slopes 41.3 via wetlands 16.6 I 1,157.4 ha = 4.46 sq. mi. I b.) Use yield coefficients (Sopper and Lull, 1970) with watershed area, Low yield estimate = 1.7 cu. m/min / sq. mi. I High yield estimate = 2.55 cu. m/min / sq. mi. Low estimate = 1.7 x 4.46 sq. mi. = 7.6 cu. m/min. I High estimate = 2.55 x 4.46 sq. mi. = 11.4 cu. m/min. I Range of flow estimates = 7.6 - 11.4 cu. m/min. 2.) Runoff Estimate Method. a.) Assume that certain portion of the precipitation (study year ppt I = 0.98 m/yr.) is runoff that flows into surface tributaries. Add direct precipitation to pond and subtract evaporative loss. The runoff estimates used are from Higgins and Colonell (1971) . I 6 b.) High runoff range = 0.61 m/yr x 1,157.4 ha = 7.060 x 10 m/yr. Low runoff range = 0.51 m/yr x 1,157.4 ha = 5.903 x 10 m/yr. I c.) Precipitation on Lost Lake / Knopp's Pond (10/87-9/88) : I 0.98 m/yr x 83 ha = 8.134 x 105 m3/yr. d.) Evaporation losses from Lost Lake / Knopp's Pond : I 0.69 m/yr x 83 ha = 5.727 x 105 m3/yr. e . ) Calculations : I 7,060,000 + 813,400 - 572,700 = 7,300,700 my'yr.' 5,903,000 + 813,400 - 572,700 = 6,143,700 irT/yr. I Range of flow estimates = 11.7 - 13.9 cu. m/min. I I I I I Hydrologic Calculations for Lost Lake / Knopp's Pond. I Lost Lake / Knopp7s Pond Detention Time Assume that flow through the system = 8.65 cu.m/min (Table 12) • Assume lake volume equals 1,843,000 cu.m (Table 1) • lyfean annual output = 4,546,440 cu.m/yr 1,843,000 cu.m = 0.405 yr x 365 day/yr = 148 days I 4,546,440 cu.m/yr * Lost Lake / Knopp's Pond Response Time I In 2 Half Life Response Time = Where: t 1/2 = half life concentration time (yr) for Lost Lake / Knopp's Pond. T = lake residence time (yr) 0 . 6931 • Z = average lake depth fm) t 1/2 = 1 12 = °-°86 yr • 0.405 + 1.8 The lake's response time is estimated at 3x-5x the concentration half life of | Lost Lake / Knopp's Pond or (0.086 x 3 or 5 = 0.258 or 0.430 yr) 94 - 157 days. i i i i i i i i I Calculation of Groundwater Inputs into Lost lake / Knopp's Pond I Based on Seepage tfeter Efeasurements I Procedure and Assumptions: 1. Place seepage meters at regular intervals around the periphery of the lake. Get groundwater seepage rates from I meters. 2. Measure distance (m) between adjacent seepage meter transect I locations. Determine shoreline lengths between the midpoints between meter transects. This gives a shoreline distance with the seepage transect approximately centered. Assume that all I seepage in this shoreline length is uniform. 3. Estimate distance from shoreline that seepage flows will occur. This is somewhat subjective, but takes into account I shoreline relief, slope of bottom, and nature and depth of bottom sediments. I 4. Determine seepage flows along the transect into lake. This can be done by assuming a linear or exponential function from shoreline to farthest distance. Since this is usually based only on 2 data points, an exponential function, although I theoretically better, can lead to extreme values, and is usually not used. If a linear function is assumed, the amount of seepage is integrated over the length of the I seepage distance. This value can be divided by the length of the seepage distance to give an average seepage rate. Note that if the two seepage meters are placed about equidistantly I from themselves and the ends of the seepage distance, averaging of their seepage rates approximates the linear function method. I 5. Calculate the hydrologic contribution of each shoreline length and convert to flow measurements. Sum flow contributions from all shoreline lengths to get total yearly I groundwater seepage to the lake. 6. Calculations : I Shoreline length x transect length x average seepage rate x time units I = Groundwater seepage flow along shoreline length. Sum all groundwater seepage from all shoreline segments. I = Groundwater seepage flow to the lake. Sample Calculation : 3 I 75 m x 25 m x 5 1/sq. m/day x 1 cu.m/10 1 x day/24 hr x hr/60 min I = 0.0065 cu.m/min. [GW flow from one shoreline length] . I I LOST LAKE/KNOPFS PGND SEEPAGE Volume r ' - - ' r- r-n I time" change i Date \>leter It shore CM) (KR> (L) (1»D) 08/20/87 1 2.4 4.2S 1.73 v =••> "5 7 9 4.13 1.52 32131 I O 2.4 4,13 .97 21.1? 4 6.7 3.?5 2.54 58.02 5 2.1 3.92 2.45 56 . 39 6 10. S 3.58 2.69 67.80 c;c: I 7 2.4 4.73 10.49 8 9.8 4.82 . £ J 4.68 9 4.0 4.75 6.3 11.97 10 4. SO .13 2.44 *H 11 w' i r 4.55 .19 3.77 I 12 15.2 4.66 .02 .40 08/21/87 13 1.8 6.28 2.67 38,36 14 7.6 6.17 1.36 19.8? n^ 15 3.0 6.17 . £u 5.26 I 16 7.2 6.03 .81 12.12 17 3.4 6.10 .42 6.21 18 4.6 3.97 5.20 78. 6? 1? 2.4 5.10 .98 17,33 20 9.1 4. 85 .99 5.3? I 21 4.S 5,00 1.38 24.90 22 9.8 4.93 -.01 -.18 23 1.8 4.85 1.45 26.97 88/22/87 24 S.S 4. 35 .06 1.17 I 25 3.0 *5 5 '• -.50 -14.41 26 1^.2 3,25 -.OS -2,22 £(' 2.7 3.00 -.45 -13.33 28 22.? 2.9? 1.73 54,07 27' 1.8 "i C>7 .50 15.1? I 7 7= 9 no 28' 7.3 L. . Uu 68.24 if?' 2.4 2,93 i iU 8.62 30 6.7 2.90 .36 11.20 31 1.3 2,85 .35 11.24 I 32 6.1 2.63 1.23 42.20 33 1.5 ? 7.i, .25 8.17 08/25/87 34 10.4 2J3 -.07 -2.31 37 1.2 3.16 .52 14.85 38 5.6 2 ?' .5? 18.23 I 39 2.1 2.97 .12 3.4^ 40 9.5 2.?2 .08 2.63 41 - 2.6 2 '.70 .42 14.04 42 9.0 L*> . JROQ .31 10.84 I 43 9,5 3.23 .06 1.65 44 9.9 3.13 -.2? -B.3<5 45 1.7 3.20 .23 6.46 46 8.5 3.93 .28 8.34 47 2.3 3.22 1.10 31.10 I 08/26/87 48 6.? 3.02 .0? 2.69 4? 1.7 3.08 .87 25.49 50 5.9 3.10 .73 21.25 51 2.3 2.92 15 4.63 I 52 7.9 2.77 .14 4.56 53 1.7 3.00 .16 4.81 54 8.1 2.30 .31 9.9? 55 2.1 3.58 99 5.54 56 8.5 3.38 .34 9.96 I 57 2.1 3.48 .18 4.67 58 10.7 ' 3.30 .10 2.73 59 1.4 3.36 1.12 30.08 60 11.3 3. 23 .18 4.?5 I I I I I I LOST UKE/KNOFPS PCND SEEFASE (32) Seapaca Dist. Tfcm time chanoe Seepaqe Date Meter 3 shore 01) Assumptions: i 1. Basal flow during proposed period of drawdown ,(Oct-Nov) assumed • to be 3.5+ cfs; based on tributary flows (KP1 + KP2 + KP3) during | study year 1987-1988. 2. Groundwater seepage in lake estimated as 1.0+ cfs; based on actual I seepage meter rates (0.92 average seepage) and groundwater maps. 3. Combined flows needed to pass = 3.5 + 1.0 - 4.5 cfs i 4. Assume drawdown of 5 ft from top of spillway. Hypsographic curve indicates a lowered pool surface area of 45% of normal pool. • 5. Normal pool area =82.5 hectares, depth = 1.6 m (5 ft) Drawdown volume = [(0.55) x (825,000)] x 1.6 = 726,000 cu. m _ 6. Drawdown of pool over six weeks. ™ 726,000 cu. m /42 days x 1/24 x 1/60 = 12.0 cu m/min. 12 cu. m/min x cfs/1.7 cu. m/min = 7.1 cfs • 7. Total flow needed to pass basal flows and draw pool down 5 ft over a six week period = 4.5 + 7.1 cfs = 11.6 cfs, round to 12 cfs. • i i i i i i i I Calculation of Amount of Piping Needed to I Dewater Lost Lake / Knopp's Pond Calculations from Bernoulli's Equation: v = [(2 g h) / 1 + K + (f I/O)]172 2 1 where : g = 32 ft/ sec K = minor loss coefficent = 1.2 (2 x 0.6; due to "bends" in pipe) L = 75' D = 1.0 I f = friction factor =0.02 H = (3 to 8'} Velocity calculations for range of head differentials: I V = [(2 x 32 x 3) / 1 + 1.2 + {0.02 x 75)/1.0]1/2 = 7 fps 1 /? v = [<2 x 32 x 8) / 1 + 1.2 + (0.02 x 75)/1.0]1/z « 11 fps - * Range = 7 to 11 fps, assume median =9.0 fps I Calculation of flow through 1 foot diameter pipe: • Q = pipe cross-section X velocity Q = (3.14/4) x (l.O)2 x 9.0 = 7 cf s since 12 cfs is needed to be passed; need 2 pipes or • 2 X 7 = 14 cfs for drawdown over six week period. Check for cavitation: i i i i i i JOB- BAYSTATE ENVIRONMENTAL CONSULTANTS, INC. SHEET NO. OF — 296 North Main Street CALCULATED BY. DATE. EAST LONGMEADOW, MASSACHUSETTS 01028 (413) 525-3822 CHECKED 8Y DATE. SCALE -7U*~ f/ /* L*t & On i* -_ 0-f.t. J /e /*> AJ ft 10 63 M /Mm BO l*w .10 12-0 4«* 3.06 ^9 ff Wtft^«Ajr..kiJt <-/ ..^ A/ a taXYA. 0_5Z% US£- 52-J AijU. tC/ tv'A^X /O M/dl rtlH.1V -H°W CA Cu ../.ilk **/' yt^Ay^i Ta^^L^L^^t JL, 000 (LW. ^ «i*n.*iM 0#t*_ /- ir^g^/i J> .3fe.r »¥_1 L -Way /V,0- l Int. OHw Hoi OWI1. I I I Calculation of Phosphorus Loading by Atmospheric Deposition and Wildlife I Atmospheric Deposition An atmospheric deposition factor of 0.24 kg P/ha/yr was used, due to the I combination of forested, agricultural and residential land use in the watershed. The area of the lake is approximately equal to 83 hectares. Thus, direct atmospheric deposition = 0.24 kg P/ha/yr x 83 ha = 19.9 kg I P/yr. Wildlife Deposition I The prevailing wildlife in the lake is waterfowl. Observations during the study year noted few resident ducks, geese and herons. There are reports of migratory flocks, especially Canadian geese. Assume a yearly density of 0.5 I birds per hectare over the year, or 42 birds. Using a mean value of 0.135 kg P/bird/yr, the wildlife input = 42 birds x 0.135 kg P/bird/yr = 5.7 kg I P/yr. I Calculation of Internal Phosphorus Trad from Bottom Sediments. 1. From information from dissolved oxygen profiles (Figure 8); anoxia (assume I for DO concentrations of 2.0 mg/1 or less) persists at or below 7.0 m of depth between May 23 and September 24 (126 days) . Assume anoxia at depths at or below 7.0 m for this period. I 2. From hypsographic chart (Figure 3), estimate the area of lake system affected (>^ 7 m) as 5% of surface 'area: I 0.05 x 83 ha x 10,000 sq. m ha = 41,500 sq. m 3. An empirical determination of phosphorus release from anoxic sediments in I Knopp's Pond was made using a period (June 9 - July 19,1988) when water column is very stable. Assumptions are that no diffusion, mixing or uptake is occurring. Total phosphorus values in hypolimnion increased from 10 to 80 ug I P/l 42 days. Over a square meter of deep water you have 2000 1 of hypolimnion. Totaling increases in phosphorus gives you 140 mg P/sq. m/42 days. These values translate to 3.13 mg P/sq. m/day. A remineralization release rate of 6.2 mg I P/sq. m/day is assumed. 4. Total phosphorus load from bottom sediments is: I 41,500 sq. m x 3.13 mg P/sq. m/day x 1 kg/1,000,000 mg x I 126 days = 16.4 kg/yr. I I Calculation of Phosphorus and Nitrogen Loading by Septic Systems _ into Lost Lake / Knopp's Pond • Assumptions: i 1, .Approximately 250 residences within 500 ft of Lost Lake or Knopp's Pond are • involved (200 shown on 1979 USGS map, active growth in the area.) Virtually I all are serviced by on-site wastewater systems. 2, Average unit residency = 2.6 people/residency (Table 11, this report). I 3, Residency span factor = 0.80 some summer-only residences (Table 11) . 4, Average P loading coefficient = 1.78 kg/resident/yr. | Selection of coefficient from range of 0.74-3.0 kg/resident/yr (Brown and Associates, 1980). Average number of phosphorus detergent users, low number _ of garbage grinders. (Mean value selected). I Average N loading coefficient - 4.61 kg/resident/yr. Selection of coefficient from range of 18.- 2.0 kg/resident/yr (Brown and • Associates, 1980) . (Median value selected) . I 5, Septic system efficiency of phosphorus retention can range from 60-99% • Distance of systems from lake is short (avg. distance - 140 ft), but depth J to water table and good maintenance records help compensate. Use a range of 85% to 95% reduction of effluent. Septic system efficiency of nitrogen retention ranges from 50-70%, but slow percolation into groundwater would place this middle of range. Calculations i Phosphorus-loading : 250 residences x 2.6 people/residences x 0.80 residency factor x 1.0 septic i system usage factor x 1.78 kgP/person/yr x 0.05 - 0.15 phosphorus retention factor = range of 46.2 - 138.8 kgP/yr possible. • Nitrogen-loading : 250 residences x 2.6 people/residences x 0.80 residency factor x 1.0 septic I system usage factor x 4.61 kgN/person/yr x 0.40 nitrogen retention factor = range of 959 kgN/yr possible. i i i i I I I Lost Lake / Khcpp's Pond Determination of Permissible and Critical Loading I Phosphorus Vollenweider Loading Analysis Z/ = 1.8 = 4.44 where: Z = mean depth (m) I td 0.405 td = detention time (yr) Area of Lost Lake / Knopp's Pond = 83.0 ha = 830,000 sq.m I for permissible (oligotrophic) loading: 0.21 g P/sq.m/yr x 830,000 sq.m = 174 kg P/yr I for critical (eutrophic) loading: I 0.42 g P/sq.m/yr x 830,000 sq.m = 349 kg P/yr Lost Lake / Khofp7 s Pond Phospfaorias/Qilorcphyll/SeccM disk transparency. I Prediction of chlorophyll (chl) from average in-lake total phosphorus (P) I . concentration (Vblleriweider, 1982) [chl] = .28 [P] °"96 in-lake (KP-3,4,5) TP = 39 ug/1 (range = 10-84} I for TP" = 39; chl a = 9.9 ug/1 TP = 10; chl a = 2,6 ug/1 I TP - 84; chl a_ = 20.7 ug/1 Compare with actual Lost Lake / Knopp' s Pond mean chlorophyll value of 1.9 ug/1 and a range of 0.6 - 4.4 ug/1 I Prediction of Secchi disk transparency from chlorophyll a. values [from Vollenweider (1982) ] -0.51 I [Secchi] =9.33 [chl] in-lake [chl a] =1.9 ug/1 range = 0.6 - 4.4 ug/1 I with chl a = 1.9; SDT = 6.7 m chl a = 0.6; SDT = 12.1 m chl _a = 4.4; SDT = 4.4 m I Compare with actual Knopp's Pond mean Secchi disk transparency of 4.5 m and a range of 3.4 - 5.7 m. [Note that this analysis does not use data from Lost Lake, as too many measurements were "to the bottom", which means that I they would go further had they not be intercepted by the bottom.] I I I USEFUL CONVERSIONS I Multiply... bv. . . to obtain... I Acre (ac) 0.4047 Hectare (ha) Acre (ac) 43,560 Square Feet (sq.ft) I Acre (ac) 4,047 Square Meters (sq.m) Acre (ac) 0.00156 Square Miles (sq.mi) Acre Feet (af) 1613.3 Cubic Yards (cy) Centimeters (cm) 0.3937 Inches (in) I Cubic Feet (cu.ft) 0.0283 Cubic Meters (cu.m) Cubic Feet (cu.ft) 0.0370 Cubic Yards (cy) Cubic Feet (cu.ft) 7.4805 Gallons (gal) I Cubic Feet (sq.ft) 28.32 Liters (1) Cubic Feet/Second (cfs) 1.7 Cubic Meters/Minute (cu.m/min) Cubic Feet/Second (cfs) 6463 Million Gallons/Day (mgd) I Feet (ft) 3048 Meters (m) Feet (ft) 0001894 Mile (mi) Kilograms (kg) 205 Pounds (Ib) Kilometers (km) 6214 Miles (mi) I Liters (1) 2642 Gallons (gal) Liters (1) 057 Quarts (qt) Meters (m) 094 Yards (yd) I Milligrams/Liter (mg/1) 0 Parts Per Million (ppm) Micrograms/Liter (ug/1) 0 Parts Per Billion (ppb) Square Kilometers (sq.km) 3861 Square Miles (sq.mi) I Square Meters (sq.m) Hectares (ha 0.0001 I I I I I I I I I APPENDIX E. General Aquatic Glossary. I I GENERAL AQUATIC GLOSSARY Abiotic - Pertaining to any non-biological factor or influence, I such as geological or meteorological characteristics. Acid precipitation - Atmospheric deposition (rain, snow, dryfall) of free or combined acidic ions, especially the nitrates, sulfates and oxides of nitrogen and sulfur fumes from industrial I smoke stacks. Adsorption - External attachment to particles, the process by I which a molecule becomes attached to the surface of a particle. Algae - Aquatic single-celled, colonial, or multi-celled plants, I containing chlorophyll and lacking roots, stems, and leaves-. Alkalinity - A reference to the carbonate and bicarbonate concentration in water. Its relative concentration is indicative I of the nature of the rocks within a drainage basin. Lakes in sedimentary carbonate rocks are high in dissolved carbonates (hard-water lakes) whereas lakes in granite or igneous rocks are I low in dissolved carbonate (soft-water lakes). Ammonia Nitrogen - A form of nitrogen present in sewage and is also generated from the decomposition of organic nitrogen. It I can also be formed when nitrites and nitrates are reduced. Ammonia is particularly important since it has high oxygen and chemical demands, is toxic to fish in un-ionized form and is an I important aquatic plant nutrient because it is readily available. Anadromous - An adjective used to describe types of fish which I spawn in freshwater rivers but spend most of their adult lives in the ocean. Before spawning, anadromous adult fish ascend the rivers from the sea. I Anoxic - Without oxygen. Aphotic Zone - Dark zone, below the depth to which light I penetrates. Generally equated with the zone in which most photosynthetic algae cannot survive, due to light deficiency. Aquifer - Any geological formation that contains water, I especially one that supplies wells and springs; can be a sand and gravel aquifer or a bedrock aquifer. I Artesian - The occurrence of groundwater under sufficient pressure, to rise above the upper surface of the aquifer. I Assimilative Capacity - Ability to incorporate inputs into the system. With lakes, the ability to absorb nutrients or other I potential pollutants without showing extremely adverse effects. I I I Attenuation - The process whereby the magnitude of an event is _ reduced, as the reduction and spreading out of the impact of I storm effects or the removal of certain contaminants as water • moves through soil. Background Value - Value for a parameter that represents the | conditions in a system prior to a given influence in space or time. — Bathymetry - The measurement of depths of water in oceans, seas, or lakes or the information derived from such measurements. Benthic Deposits - Bottom accumulations which may contain bottom- • dwelling organisms and/or contaminants in a lake, harbor, or stream bed. __ • Benthos - Bottom-dwelling organisms living on, within or attached to the sediment. The phytobenthos includes the aquatic _ macrophytes and bottom-dwelling algae. The zoobenthos (benthic I fauna) includes a variety of invertebrate animals, particularly ' larval forms and molluscs. Benthic - Living or occupying space at the bottom of a water | body, on or in the sediment. Best Management Practices - (BMP's) State-of-the-art techniques I and procedures used in an operation such as farming or waste disposal in order to minimize pollution or waste. Bio-available - Able to be taken up by living organisms, usually B refers to plant uptake of nutrients. Biocide - Any agent, usually a chemical, which kills living | organisms. Biological Oxygen Demand - The BOD is an indirect measure of the B organic content of water. Water high in organic content will B consume more oxygen due to the decomposition activity of bacteria in the water than water low in organic content. It is routinely • measured for wastewater effluents. Oxygen consumption is | proportional to the organic matter in the sample. Biota - Plant (flora) and animal (fauna),. life. B Biotic - Pertaining to biological factors or influences, concerning biological activity. i Bloom - Excessively large standing crop of algae, usually visible to the naked eye. " " • i i i I Bulk Sediment Analysis - Analysis of soil material or surface I deposits to determine the size and relative amounts of particles Composing the material. I CFS - Cubic feet per second, a measure of flow. Chlorophyll - Major light gathering pigment of all photosynthetic organisms imparting the characteristic color of green plants. I Its relative measurement in natural waters is indicative of the concentration of algae in the water. I Chlorophyte - Green algae, algae of the division Chlorophyta. Chrysophyte - Golden or golden-brown algae, algae of the division I Chrysophyta. Color - Color is determined by visual comparison of a sample with known concentrations of colored solutions and is expressed in I standard units of color. Certain waste discharges may turn water to colors which cannot be defined by this method; in such cases, the color is expressed qualitatively rather than numerically. I Color in lake waters is related to solids, including algal cell concentration and dissolved substances. Combined Sewer - A sewer intended to serve as both a santiary I sewer and a storm sewer. It receives both sewage and surface runoff. I Composite Sample - A number of individual samples collected over time or space and "composited into one representative sample. I Concentration - The quantity of a given constituent in a unit of volume or weight of water. Conductivity - The measure of the total ionic concentration of I water. Water with high total dissolved solids (TDS) level would have a high conductance. A conductivity meter tests the flow of electrons through the water which is heightened in the presence I of electrolytes (TDS). Confluence - Meeting point of two rivers or streams. I Conservative Substance - Non-interacting substance, undergoing no kinetic reaction; chlorides and sodium are approximate examples. I Cosmetic - Acting upon symptoms or given conditions without correcting the actual cause of the symptoms or conditions. I Cryptophyte - Small, flagellated algae of variable pigment composition, algae of the division Cryptophyta, which is often I placed under other taxonomic divisions. I I I Cyanophyte - Bluegreen algae/ algae of the division Cyanophyta, • actually a set of pigmented bacteria. I Decomposition - The metabolic breakdown of organic matter, releasing energy and simple organic and inorganic compounds which I may be utilized by the decomposers themselves (the bacteria and I fungi) . Deoxygenation - Depletion of oxygen in an area, used often to | describe possible hypolimnetic conditions, process leading to anoxia. _ Diatom - Specific type of chrysophyte, having a siliceous ' frustule (shell) and often elaborate ornamentation, commonly found in great variety in fresh or saltwaters. Often placed in • its own division, the Bacillariophyta. | Dinoflagellate - Unicellular algae, usually motile, having _ pigments similar to diatoms and certain unique features. More • commonly found in saltwater. Algae of the division Pyrrhophyta. m Discharge Measurement - The volume of water which passes a given location in a given time period, usually measured in cubic feet •I per second (cfs) or cubic meters per minute {m /min) . Dissolved Oxygen (P.O.) - Refers to the uncombined oxygen in | water which is available to aquatic life. Temperature affects the amount of oxygen which water can contain. Biological _ activity also controls the oxygen level. D.O. levels are I generally highest during the afternoon and lowest just before • sunrise. Diurnal - Varying over the day, from day time to night. i Domestic Wastewater - Water and dissolved or particulate • substances after use in any of a variety of household tasks, " I including sanitary systems and washing operations. Drainage Basin - A geographical area or region which is so sloped • and contoured that surface runoff from streams and other natural I watercourses is carried away by a single drainage system by gravity to a common outlet. Also referred to as a watershed or • drainage area. The definition can also be applied to subsurface g flow in groundwater. ~ " Dystrophic - Trophic state of a lake in which large quantities of I nutrients may be present, but are generally unavailable (due to' • organic binding or other causes) for primary production. Often associated with acid bogs. • i i i I Ecosystem - A dynamic association or interaction between I communities of living organisms and their physical evironment. Boundaries are arbitrary and must be stated or implied. I Elutriate - Elutriate refers to the washings of a sample of material. Epilimnion - Upper layer of a stratified lake. Layer that is I mixed by wind and has a higher average temperature than the hypolimnion. Roughly approximates the euphotic zone. I Erosion - The removal of soil from the land surface, typically by runoff water. I Eskar - A winding, narrow ridge of sand or gravel deposited by a stream flowing under glacial ice. Euglenoid - Algae similar to green algae in pigment composition, I but with certain unique features related to food storage and cell wall structure. Algae of the division Euglenophyta. I Eutrophic - High nutrient, high productivity trophic state generally associated with unbalanced ecological conditions and poor water quality. I Eutrophication - Process by which a body of water ages, most often passing from a low nutrient concentration, low productivity state to a high nutrient concentration, high productivity stage. I Eutrophication is a long-term natural process, but it can be greatly accelerated by man's activities. Eutrophication as a I result of man's activities is termed cultural eutrophication. Evapotranspiration - Process by which water is lost to the atmosphere from plants. I Fauna - A general term referring to all animals. Fecal Coliform Bacteria - Bacteria of the coli group that are I present in the intestines or feces of warm-blooded animals. They are often used as indicators of the sanitary quality of the water. In the laboratory they are defined as all organisms which produce blue colonies within 24 hours when incubated at 44.5°(> I 0.2 C on M-FC medium (nutrient medium for bacterial growth). Their concentrations are expressed as number of colonies per 100 I ml of sample. Fecal Streptococci Bacteria - Bacteria of the Streptococci group found in intestines of warm-blooded animals. Their presence in I water is considered to verify fecal pollution. They are characterized as gram positive, cocciod bacteria which are . I capable of growth in brain-heart infusion broth. In the I I I laboratory they are defined as all the organisms which produce _ red or pink colonies within 48 hours at 35 C+_ 1.0 C on KF medium • (nutrient medium for bacterial growth). Their concentrations are ™ expressed as number of colonies per 100 ml of sample. Flora - A general term referring to all plants. i Food Chain - A linear characterization of energy and chemical • flow through organisms such that the biota can be separated into I functional units with nutritional interdependence. Can be expanded to a more detailed characterization with multiple _ linkage, called a food web. I French (or Pit) Drain - Water outlet which allows fairly rapid removal of water from surface, but then allows subsurface • percolation. Generally consists of sand and gravel layers under | grating or similar structure, at lowest point of a sloped area. Water runs quickly through the coarse layers, then percolates • through soil, often without the use of pipes. The intent is the I purification of most percolating waters. * Grain Size Analysis - A soil or sediment sorting procedure which • divides the particles into groups depending on size so that their I relative amounts may be determined. Data from grain size analyses are useful in determining the origin of sediments and • their.behavior in suspension. I Groundwater - Water in the soil or underlying strata, subsurface water. i Hardness - A physical-chemical characteristic of water that is commonly recognized by the increased quantity of soap required to • produce lather. It is attributable to the presence of alkaline | earths (principally calcium and magnesium) and is expressed as equivalent calcium carbonate (CaCO-J . m Humus - Humic substances form much of the organic matter of I™ sediments and water. They consist of amorphous brown or black colored organic complexes. I Hydraulic Detention Time - Lake water retention time, amount of time that a random water molecule spends in a water body; time • that it takes for water to pass from an inlet to an outlet of a • water body. Hydraulic Dredging - Process of sediment removal' using a floating I dredge to draw mud or saturated sand through a pipe to be • deposited elsewhere. . - Hydrologic Cycle - The circuit of water . movement from the atmosphere to the earth and return to the atmosphere through I I I various stages or processes such as precipitation, interception, runoff, infiltration, percolation, storage, evaporation, and transpiration. Hypolimnion - Lower layer of a stratified lake. Layer that is mainly without light, generally equated with the aphotic zone, and has a lower average temperature than the epilimnion. Impervious - Not permitting penetration or percolation of water. Intermittent - Non-continuous, generally referring to the occasional flow through a set drainage path. Flow of a discontinuous nature. Kame - A short, steep ridge or hill of stratified sand or gravel deposited in contact with glacial ice. Kjeldahl Nitrogen - The total amount of organic nitrogen and ammonia "in a sample, as determined by the Kjeldahl method, which involves digesting the sample with sulfuric acid, transforming the nitrogen into ammonia, and measuring it. Leachate - Water and dissolved or particulate substances moving out of a specified area, usually a landfill, by a completely or partially subsurface route. Leaching - Process whereby nutrients and other substances are removed from matter (usually soil or vegetation) by water. Most often this is a chemical replacement action, prompted by the quality of the water. Lentic -..Standing, having low net directional motion. Refers 'to lakes and impoundments. Limiting Nutrient - That nutrient of which there is the least quantity, in relation to its importance to plants. The limiting nutrient will be the first essential compound to disappear from a productive system, and will cause cessation of productivity at that time. The chemical form in which the nutrient occurs and the nutritional requirements of the plants involved are important here. Limnology - The comprehensive study of lakes, encompassing physical, chemical and biological lake conditions. Littoral Zone - Shallow zone occurring at the ed'ge of aquatic^ ecosystems, extending from the shoreline outward to a point where rooted aquatic plants are no longer found. Loading - Inputs into a receiving water that may exert a detrimental effect on some subsequent use of that water. I Lotic - Flowing, moving. Refers to streams or rivers. _ Macrofauna - A general term which refers to animals which can be ' seen with the naked eye. Macrophyte - Higher plant, macroscopic plant, plant of higher | taxonomic position than algae, usually a vascular plant. Aquatic macrophytes are those macrophytes that live completely or • partially in water. May also include algal mats under some I definitions. Mesotrophic - An intermediate trophic state, with variable but I moderate nutrient concentrations and productivity. • Metalimnion - The middle layer of a stratified lake, constituting • the transition layer between the epilimnion and hypolimnion and | containing the thermocline. Mixis - The state of being mixed, or the process of mixing in a I lake. • MGD - Million gallons per day, a measure of flow. • Micrograms per Liter (ug/1? - A unit expressing the concentration of chemical constituents in solution as mass (micrograms) of • solute per unit volume (liter) of water. One thousand micrograms I per liter is equivalent to one milligram per liter. Nitrate - A form of nitrogen that is important since it is the I end product in the aerobic decomposition of nitrogenous matter. • Nitrogen in this form is stable and readily available to plants. Nitrite - A form of nitrogen that is the-oxidation product of | ammonia. It has a fairly low oxygen demand and is rapidly converted to nitrate. The presence of nitrite nitrogen usually _ indicates that active decomposition is taking place (i.e., fresh • contamination) . ™ Nitrogen - A macronutrient which occurs in the forms of organic • nitrogen, ammonia nitrogen, nitrite nitrogen and nitrate | nitrogen. Form of nitrogen is related to a successive decomposition reaction, each dependent on the preceding one, and « the progress of decomposition can be determined in terms of the I relative amounts of these four forms of nitrogen. Nitrogen fixation - The process by which certain'bacteria and • bluegreen algae make organic nitrogen compounds (initially NH.-f-) • from elemental nitrogen (N~) taken from the atmosphere or dissolved in the water.- • i i i I Non-point Source - A diffuse source of loading, possibly I localized but not distinctly definable in terms of location. Includes runoff from all land types. I Nutrients - Are compounds which act as fertilizers for aquatic organisms. Small amounts are necessary to the ecological balance of a waterbody, but excessive amounts can upset the balance by causing excessive growths of algae and other aquatic plants. I Sewage discharged to a waterbody usually contains large amounts of carbon, nitrogen, and phosphorus. The concentration of carbonaceous matter is reflected in the B.O.D. test. Additional I tests are run to determine the concentrations of nitrogen and phosphorus. Storm water runoff often contributes substantial nutrient loadings to receiving waters. I Oligotrophic - Low nutrient concentration, low productivity trophic state, often associated with very good water quality, but not necessarily the most desirable stage, since often only I minimal aquatic life can be supported. Organic - Containing a substantial percentage of carbon derived I from living organisms; of a living organism. Outwash - Sand and gravel deposited by meltwater streams in front I of glacial ice. Overturn - The vertical mixing of major layers of water caused by seasonal changes in temperature. In temperate climate zones I overturn typically occurs in spring and fall. Oxygen Deficit - A situation in lakes where respiratory demands for oxygen become greater than its production via photosynthesis I or its input from the drainage basin, leading to a decline in oxygen content. I Periphyton - Attached forms of plants and animals, growing on a substrate. I £H - A hydrogen concentration scale from 0 (acidic) to 14 (basic) used to characterize water solutions. Pure water is neutral at pH 7.0. I Phosphorus - A macronutrient which appears in waterbodies in combined forms known as ortho- and poly-phosphates and organic phosphorus. Phosphorus may enter a waterbody in agricultural I runoff where fertilizers are used. Storm water runoff from highly urbanized areas, septic system leachate, and lake bottom sediments also contribute phosphorus. A critical plant nutrient I which is often targeted for control in eutrophication prevention I plans. I I I Photic Zone - Illuminated zone, surface to depth beyond which • light no longer penetrates. Generally equated with the zone in I which photosynthetic algae can survive and grow, due to adequate light supply. Photosynthesis - Process by which primary producers make organic • molecules (generally glucose) from inorganic ingredients, using light as an energy source. Oxygen is evolved by the process as a • byproduct. | Phytoplankton - Algae which are suspended, floating or moving . only slightly under their own power in the water column. Often • this is the dominant algal form in standing waters. ™ Plankton - The community of suspended, floating, or weakly • swimming organisms that live in the open water of lakes and I rivers. Point Source - A specific source of loading, accurately definable • in terms of location. Includes effluents or channeled discharges that enter natural waters at a specific point. Pollution - Undesirable alteration of the physical, chemical or • biological properties of water, addition of any substance into water by human activity that adversely affects its quality. • Prevalent examples are thermal, heavy metal and nutrient | pollution. Potable - Usable for drinking purposes, fit for human I consumption. ™ Primary Productivity (Production) - Conversion of inorganic • matter to organic matter by photosynthesizing organisms. The I creation of biomass by plants. Riffle Zone - Stretch of a stream or river along which I morphological and flow conditions are such that rough motion of the water surface results. Usually a shallow rocky area with rapid flow and little sediment accumulation. I Riparian - Of, or related to, or bordering a watercourse. Runoff - Water and its various dissolved substances or - J particulates that flows at or near the surface of land in an unchanneled path toward channeled and usually recognized _ waterways (such as a stream or river). I Saturation Zone - Volume of soil in which all pore spaces are filled with water; the volume below the water table. ... I i i i I Secchi Disk Transparency - An approximate evaluation of the I transparency of water to light. It is the point at which a black and white disk lowered into the water is no longer visible. Secondary Productivity - The growth and reproduction {creation of I biomass) by herbivorous (plant-eating) organisms. The second level of the trophic system. I Sedimentation - The process of settling and deposition of suspended matter carried by water, sewage, or other liquids, by gravity. It is usually accomplished by reducing the velocity of I the liquid below the point at which it can transport the suspended material. Sewage (Wastewater) - The waterborne, human and animal wastes I from residences, industrial/commercial establishments or other places, together with such ground or surface water as may be I present. Specific Conductance - Yields a measure of a water sample's capacity to convey an electric current. It is dependent on I temperature and the concentration of ionized substances in the water. Distilled water exhibits specific conductance of 0.5 to 2.0 micromhos per centimeter, while natural waters show values from 50 to 500 micromhos per centimeter. In typical New England I lakes. Specific Conductance usually ranges from 100-300 micromhos per cm. The specific conductance yields a generalized measure of I the inorganic dissolved load of the water. Stagnant - Motionless, having minimal circulation or flow. Standing Crop - Current quantity of organisms, biomass on hand. I The amount of live organic matter in a given area at any point in time. I Storm Sewer - A pipe or ditch which carries storm water and surface water, street wash and other wash waters or drainage, but I excludes sewage and industrial wastes. Stratification - Process whereby a lake becomes separated into two relatively distinct layers as the result of temperature and density differences. Further differentation of the layers I usually occurs as the result of chemical and biological processes. In most lakes, seasonal changes in temperature will reverse this process after some time, resulting in the mixing of I the two layers. Stratified Drift - Sand, gravel or other materials deposited by a glacier or its meltwater in a layered manner, according to I particle size. I I I I Substrate - The base of material on which an organism lives, such as cobble, gravel, sand, muck, etc. • Succession - The natural process by which land and vegetation patterns change, proceeding in a direction determined by the • forces acting on the system. I Surface Water - Refers to lakes, bays, sounds, ponds, reservoirs, springs, rivers, streams, creeks, estuaries, marshes, inlets, I canals, oceans and all other natural or artificial, inland or " coastal, fresh or salt, public or private waters at ground level. Suspended Solids - Those which can be removed by passing the | water through a filter. The remaining solids are called dissolved solids. Suspended solids loadings are generally high « in stream systems which are actively eroding a watershed. I Excessive storm water runoff often results in high suspended * solids loads to lakes. Many other pollutants such as phosphorus are often associated with suspended solids loadings. I Taxon (Taxa) - Any hierarchical division of a recognized classification system, such as a genus or species. • Taxonomy - The division of biology concerned with the classification and naming of organisms. The classification of — organisms is based upon a hierarchical scheme beginning with • Kingdom and progressing to the Species level or even lower. • Thermocline - Boundary level between the epilimnion and • hypolimnion of a stratified lake, variable in thickness, and | generally approximating the maximum depth of light penetration and mixing by wind. _ Till - Unstratified, unsorted sand, gravel, or other material * deposited by a glacier or its meltwater. Trophic Level - The position in the food chain determined by the I number of energy transfer steps to that level; 1 = producer; 2 = herbivore; 3, 4, 5 = carnivore. • Trophic State - The stage or condition of an aquatic system, characterized by biological, chemical and physical parameters. Turbidity - The measure of the clarity of a water sample. It is I expressed in Nephelometric Turbidity Units which are related to the scattering and absorption of light by the water sample. • Volatile Solids - That portion of a sample which can be burned off, consisting of organic matter, including oils and grease. _ i i i I _ Water Quality - A term used to describe the chemical, physical, • and biological characteristics of water, usually with respect to • its suitability for a particular purpose or use. Watershed - Drainage basin, the area from which an aquatic system ( receives water. Zone of Contribution - Area or volume of soil from which water is I drawn into a well. Zooplankton - Microscopic animals suspended in the water; • protozoa, rotifers, cladocera, copepods and other small i invertebrates. i i i i i i i i i i i i i SUBSTATE AGREEMENT FOR DIAGNOSTIC/FEASIBILITY STUDY OF LOST LAKE/KNDPS POND Attachment A The Project SHTTION I A.I Tnis attachment is incorpors-ed by reference into the foregoing Substate Agreement by Paragrapns 1.1, 1.3, 3.1, and 3.2. A. 2 General Oojective and Description of Project Ths Grantee shall complete a diagnostic/feasibility study of Lost Lake/ Knops Pond, hereinafter, referred to as the lake/pond. The scope of work to be completed under this Substate Agreement for the study is specified in this Attachment. A. 3 Description of Discrete Reimbursable Project Tasks The following constitutes tne scope of «ork to be completed by the Grantee under this Substate Agreement. A.3.1 Diagnostic Study. For tne tasks listed below all data shall be reported in metric units. .1 A description of the historical lake recreational uses up to the / /; present, the public accesses to the lake/pond, and the suitability of tne accesses to the recreational uses of the lake/pond by the general public. (.2 .An identification and review of all available reports, studies and data which relate to lake/pond and/or its watershed. The review shall determine trie applicability of such information to the diagnostic/feasibility study and all significant findings and information shall be incorporated into the draft Final Report and Final Report. The review shall include, but not oe limited, to the following reports and documents: "• a) Municipal Groundv,-=ter Resource Analysis and Protection Study, Groton, Massachusetts. March 2, 1933 by ISP, Inc. i b) Facilities Planning Report for Groton, Massachusetts. EPA Project No. C250750-01 September 1932 by Dufresne-Henry. ' c) Water Resources ar.d Hydrology of Groton, 1975 by D.W. Caldwell, Ph.D. / d) Lost Lake/Knops Pond Baseline Water Quality Survey Data: 1977, 1985. Massachusetts Division of Water Pollution Control, Technical Services Branch, Westborough, Mass. e) Study of Sewerage Needs: Evaluation of Alternatives for Groton, MA. Prepared for the Montachusetts Regional Planning Commission as part of the Montachusett-Nashua 208. Prepared by Anderson-Nicnols & Co. July 1977 f} Land Use Element: Summary Statement, Montachusett Regional Planning Corrmission. January 1973 ? J g) Montachusett-Nashua Arsawide Water Quality Management Plan Sumnary and Environmental Impact Statement. Jan. 1979. Prepared by Montachusett Regional Planning Commission, Fitchburg, MA for the U.S. Environmental Protection Agency-, Region 1. 7 tj) Water Quality Management Plan for the Nashua River Basin. A Summary Report for the Town of Groton. Prepared by the Nasnua River Program. 1974 or 1975. .3 An identification and description of the lake/pond and its watershed. The watershed description should include an accurate delineation of its boundary, area, topography, and development. A description and map of the land uses in the watershed including any historical activities that may have adversely affected the . // (g) turbidity (Nephelometric turbidity units) (n) conductivity (i) chlorides (j) total Kjeldahl-nitrogen (JO ammonia nitrogen (1) nitrate nitrogen (m) total pnosphorus (n) fecal coiiform and fecal streptococci bacteria (o) Secchi disk transparency (p) phytoplankton identification (minimum to genus level) (g) chlorophyll a (r) discharge (either instantaneous or tine integrated) Parameters a-q (above) shall be measured at three inlake locations: at each of the deepest depressions constituting the major basins in Lost Lake and Knops Pond and at a centrally located station in the Lost Lake basin. The two tributaries (Martin's Pond Brook and an unnamed stream entering on the western shore) and the outlet shall be sampled for parameters a-n and r (above). The three (3) in-lake stations shall oe sampled, at a minimum, in the epilimnion, metaiimnion, and hypolimnion during periods of , stratification. At other times, samples shall be collected near the top and near the bottom of the water column. Bacteria sampling shall be from the surface only. Phytoplankton and chlorophyll a samples shall be deptn integrated to the limit of the euphotic zone (Secchi disk depth x 3) or to 1.0 meter above the lake/pond bottom when the entire water column is eupnotic. Depth-integrated samples shall not extend into an anoxic zone, however. The in-lake stations, tributaries, and outlet shall be surveyed .for the above parameters on a biweekly schedule from March to fall circulation and monthly for the remainder of the year. Alkalinity, however, snail be sampled on a monthly schedule tnroughout the year. Upon completion of a subset of sampling, the Grantee and the Division may agree to substitute replacement parameters, to add a parameter, or to delete a parameter... In the event that this discretion is exercised, the Suostate Agreement and the Contract shall be amended accordingly. 11 A thorough investigative survey shall be completed on each of tne two tributary systems to Lost Lake/Knops Pond to accurately determine the quality and quantity of point and non-point nutrient and/or pollutant loads entering the tributaries. 12 A macrophyton survey shall be conducted during mid-August and shall be in sufficient detail to describe the areal coverage of total macrophyton and the frequency of occurrence of individual genera/species. The data shall be reported in a format compatible with the Division's Pond and Lake Information System (PALIS). 13 A discussion and evaluation of current fishery data available from the Massachusetts Division of Fisheries and wildlife shall include, but not be limited to, the following pararneters: (a) species composition (b) relative abundance C (c) growth rates for selected species populations (d) proportzibnal stock density for game species (e) status of recreational fishery If fishery data is acquired from another source, tnen the method(s) of collection shall be described. At least one wet weather survey shall be performed on all tribu- taries to Lost Lake/Knops Pond. During the storm event a composite sample shall be taken at each tributary. All composite samples shall include the first hydraulic flush and shall extend for a cumulative period of two hours, or one hour after peak hydraulic flow, whichever is the shorter time period. Parameters measured shall include, at a minimum, the following: (a) suspended solids (b) conductivity (c) total Kjeldahl-nitrogen (d) ammonia nitrogen (e) nitrate nitrogen (f) total pnosphorus (g) chloride (h) fecal coliform and fecal straptcccci bacteria * .15 A field investigation shall be performed to identify and locate ^ all storm drains that discharge directly, or proximaily, into the lake/pond and a map shall oe drawn that indicates the location of each storm drain. The construction, size, and the area drained by^ each storm drain shall be determined. Tne Grantee shall notify the Project Officer if actively flowing storm drains are located so that the scope of work can be modified, if needed." If actively flowing storm drains are found qualitative and quantitative data shall be generated during at least two (2) separate storm events. During the first storm event only, a flow- yjeighted composite sample shall be taken at each of the actively flowing storm drains discharging directly into the lake/pond. All flow-weighted composite samples shall include the first hydraulic flush and shall extend for a cumulative period of two hours, or one hour after peak hydraulic flow, 'whichever is the shorter time period. For the remaining storm event, sampling shall be on either two (2) storm drains or 10% of the active storm drains, whichever is the higher number. Selection of thesa storm drains shall oe made in consultation with the Division. In both storm events, discrete saiTiples shall be collected over a timed interval. The first hydraulic flush shall be sampled, and thereafter individual samples shall oe collected at ten (10) minute intervals for the first thirty (30) minutes and then at fifteen (15) minute inter- vals for a cumulative period of trfo (2) hours, or one (1) hour after peak hydraulic flow, whichever is the shorter time period. Sampling of storm drains should coincide with routine sampling of the inlet(s). Parameters measured shall include, at a minimum, the following: (a) suspended solids (b) conductivity (c) total Kjeldahl-nitrogen (d) arrmonia nitrogen (e) nitrate nitrogen (f) total phosphorus (g) chloride (h) fecal coiiform and fecal streptococci bacteria Heavy metals shall be determined from separate flow-weigh ted composite samples collected from the storm drains during each of the two (2) storm events. Each composite sample shall include the first hydraulic flush and shall extend for a cumulative period of two hours, or one hour after peak hydraulic flow, whichever is the shorter time period. The following heavy metals must be quan- tified for each composite sample: (a) cadmium (b) chromium (c) copper (d) iron (e) lead (f) manganese (q) zinc In addition to the parameters listed above, instantaneous discharge shall oe monitored for each storm drain. On-site volumetric measurement of rainfall (i.e., rain gauge) shall be measured as well. .16 An accurate inventory of on-site wastevjater disposal practices within 300 m (aoout 1,000 ft) of the lakeshore shall be developed. Tne inventory of each on-site system shall include, at a minimum, the type of. system, distance from the lakeshore, numoer of people per unit, number of days of use per year, age of the system, and / i/ types of appliances used (i.e., dishwasher, disposal, etc.). This J £>(C inventory shall be used in conjunction with direct measurements and indirect calculations, as approved by the Division, to determine the extent of loading from on-site wastewater systems to the lake pond. Information on the wastewater problems in the Lost Lake area as presented in the 1982 Facilites Planning Report by Dufresne-Henry (and other reports) shall be compared to current information and data collected as a result of this task. The degree of degradation and/or improvement of water quality in historic and current problem areas shall be discussed and evaluated. \ .17 At the in-lake stations, the bottom sediments must be sampled on at least one occasion and analyzed for the following: (1) total nitrogen I , (2) total phosphorus 7 O^~ (3) organic/inorganic fraction (loss on ignition) (4) heavy metals (cnromium, manganese, iron, copper, zinc, cadmium, and lead) (5) other parameters as deemed necessary by the Division to meet aporopriate permit requirements. ,o \.18 If dredging is recommended as a feasible alternative then the '^ bottom sediments shall be sampled at each proposed site on at least one occasion. Sediment core samples to the depth of proposed dredging shall be taken and analyzed for the following parameters: (1) total nitrogen (2) total phosphorus (3) organic/inorganic fraction (loss on ignition) (4) heavy metals (arsenic, cadmium, chromium, copper, iron, lead, manganese, mercury, nickel, vanadium, and zinc) (5) oil and grease (6) any other hazardous or toxic material as deemed necessary by the Division to meet appropriate permit requirements. A map depicting tne depth and physical characteristics of sediments in the lake/pond shall be generated. Sediment depth measurements shall be made by driving a probe to first refusal. These depth flieasurementsshal l be taken in a quantity and manner descriiDed in A.3.1.6 of this Appendix in areas rfhere the rfatar depth is 6.1 m (20 feet) or less. The sediment assessment shall yield information necessary to complete an application for certification required under the "Regulations for Water Quality Certification for Dredging, Dredged Materials Disposal, and Filling in the Waters of the Commonwealth" and to complete an application for an Army Corps of Engineers 404 Permit. \ ,19 Sampling, sample preservation and analytical methodology shall be conducted in conformance with the Division's Standard Operating Procedure and EPA's Methods for Chemical Analysis of Water and Wastes, or other references approved by the Division. A list of the field and laboratory methods used in tnis study shall be included in an appendix to the draft Final Report and Final Report. The field methods shall include a list of instrumentation and sampling techniques as well as sample handling, storage, and reservation. ,20 The diagnostic data collected and developed under this project shall be keyed to disk or tape, or punched on cards, so tnat it can be entered into the Division's Pond and Lake Information Systsrn (PALIS). The Grantee should contact the Division's Electronic Data Processing Section in Westoorough prior to che transfer of data and/or for specific information on format. ,21 An Environmental Notification Form must be prepared and it shall include a description of each of the proposed alternatives that are recommended in the Final Report. The Environmental Notifi- cation Form shall include the following attachments: a) site plan; and b) locus map of proposed project. Blank Environmental Notification Forms are available from: Dick Foster Executive Office of Environmental Affairs Massachusetts Environmental Policy Act Unit 100 Cambridge Street, 20th floor Boston, MA 02202 A.3.2 Feasibility Study .1 This study shall include an identification and discussion of the alternatives considered for pollution control, restoration, presarvation, or maintenance. Justification of the reasonable J and feasible selected alternate vets) that address the in-lake and ^K watershed problems and their causes, whether tney are in-lake or watershed based, shall be included. The study shall also include a discussion of reasons for rejecting alternatives. .2 Tne selection of alternatives(s) shall be followed by a discussion of technical feasibility, cost-effectiveness and anticipated water quality and recreational improvements. In this regard a , nutrient budget analysis, selected in consultation with the J Division, shall be performed using data generated from the diagnostic study to evaluate the alternative(s). The discussion shall include an analysis of the impact that the selected alternative^) will have on the annual nutrient budget. . 3j The study shall include a detailed description specifying what activities would be undertaken and identifying responsibilities J among various groups and agencies to implement each selected alternative. Preliminary engineering drawings and specifications shall be provided to show the basic construction aspects of the project, if construction is part of the selected alternative. The study shall include a discussion of the anticipated effects of the selected alternative(s) on tributary, la-lake, and downstream fish and wildlife resources. A discussion of activities to mitigate any adverse effects shall be included along with estimates of their respective costs. Comments on the proposed project by the Division of Fisheries and Wildlife and the local consarvation commission shall be included in the Final Report. If the selected alternatives involve in-lake chemical treatment, the study shall include a detailed discussion specifying the short-term and long-term effects of such treatment. A discussion of activities to mitigate any adverse effects shall be included along with estimates of their respective costs. If the selected alternatives involve lake drawdown, or construction of a lake drawdown structure, the study snail include a detailed discussion specifying the immediate and y long-term effects of this alternative on wetlands, fisheries, and wells of abutters to the lake. A discussion of activities to mitigate any adverse effects shall be included along with estimates of their respective costs. .7 If any type of dredging is proposed, the study shall include a detailed discussion of the steps that will be taken to minimize any immediate and long-term adverse effects of this selected alternative. Answers to the following questions shall be provided in the discussion: a) where will the dradge spoils be y deposited; b) how will the dredge spoils be transported to the site of deposition; c) how will the dredge spoils be de-watered and where will this process occur; and d) will there be any problem(s) in securing the necessary permits and licenses for such activities? .8 A comprehensive watershed management plan for the control of point and non-point sources of nutrients and pollutants shall be developed. A comprehensive list of alternatives for controlling nutrients and other major pollutants specific to the lake/pond watershed shall be compiled. For the Lost Lake/Knops Pond Watershed this list shall include, but not be limited to, alter- natives for controlling input of nutrients and major pollutants' from: underground storage tanks, agricultural practices, on site 7 waste disposal practices, motor boat usage, and current building zone practices. Each alternative shall be assessed for technical feasibility and cost-effectiveness. Specific alternatives shall be recorrmended to control all point and non-point sources of nutrients and/or pollutants to the lake/pond. .9 A list of local, state and federal permits, licenses, and other / governmental approvals necessary for the implementation of the ^J selected alternatives (s) as well as the identification of those responsible for the filing and approval of same shall be included in the feasibility study. .10 A task by task cost breakdown of the recommended implementation (Phase II) project shall oe developed and it shall include an estimate of the operation and maintenance costs over the life of tne project. The cost breakdown shall include the monitoring program described in Paragraph A.3.2.13. .11 A detailed description of funding sources and ho;/ they may be obtained for the implementation project shall be presented, y particularly for items which are ineligible for funding under the Chapter 623 Massachusetts Clean Lakes Program. .12 A proposed milestone work schedule for the completion of the implementation (Pnase II) project shall be developed. The milestone schedule shall include the monitoring program stated in / Paragraph A.3.2.13. Details of the schedule shall show when each v task should be completed; how the task relates to other tasks; what person,-group, or agency shall perform the task; and -the approximate cost of each task in the vrork schedule. .13 An implementation (Pnase II) monitoring program shall be developed. Tne first element of the monitoring program shall be y conducted during the project implementation period to ensure that desired objectives are achieved. This is particularly important • > * • X for construction or in-lake treatment projects to provide sufficient data for the project officer to redirect the project, if necessary. The second element shall be a three year A 1^ post-implementation or post-construction monitoring phase to evaluate project effectiveness. The monitoring program(s) shall be individually tailored to the specific implementation alternative^) and shall detail the sampling stations, sampling schedule, and parameters. ,14 A discussion of the public participation used in the development and review of the selected alternative(s) shall be included. A minimum of tiro public meetings are required. Tne first should be an informational meeting early in the diagnostic study program. The second should be conducted to present findings and recommended alternatives prior to developing the final altarnative(s). Discussion of the public participation shall include major public comments on the proposed aiternative(s) and the responses to said comments. A minimum of five (5) working . days notice of public meetings shall be given to the Division project officer, so that he/she stay attend. .15 All tasks listed abova in Paragraphs A.3.2.1 through A.3.2.14 of this Attachment shall be developed to the level of detail / necessary for them to be used in conjunction with a Phase II •J implementation Project application under the Massachusetts Clean Lakes Program (Chapter 623). A.3.3 Quarterly Progress Reports. The Grantee shall submit quarterly progress reports for the periods commencing July 1, October 1, January 1, and April 1. The Grantee shall submit such quarterly reports on or before the tenth (10th) calendar day following the last working day of the quarterly period for which the report is submitted. Each such quarterly report, at a minimum, shall in- clude the following: .1 a report of work progress relative to the milestone schedule in Section II of Attachment A and difficulties encountered during the previous three (3) months;. .2 a report of all water quality monitoring data gathered pursuant to this Agreement along with an analysis of such data to reveal the existing water quality of the lake; .3 a brief discussion of tne project findings appropriate to the work conducted during tne subject quarterly period; and .4 a report of expenditures in the subject quarterly period, those anticipated in the following quarterly period, the total expen- ditures durioo the project to date, and a thorough explanation of any discrepancies between the total expenditures to date and the projected expenditures as submitted in the Proposed Spending Plan. This explanation must include a revised Spending Plan. A.3.4 Final Report. The Grantee shall prepare and submit to the Division a Final Report that shall document project activities over the entire period of the study and wtiich shall describe the achievements of the study with respect to stated project purposes and objectives. The Final Report shall fully con- form to all requirements set forth in Section I of Attachment A of this Agree- ment. The diagnostic component of the Final Report shall also contain an interpretative and analytical discussion of all relevant data gathered under this Agreement and any prior investigations of the lake. The Final Report. shall include an abstract of less than two pages that presents the major results of the diagnostic study and the selected feasible alternative!3). The Grantee shall submit three (3) copies of the draft Final Report on'or before February 29, 1983. Upon receipt of comments suomitted on the draft Final Report by the Division, the Grantee shall forthwith revise the draft Final Report in accordance with the Division's comments and submit to the * Division .in final form ten (10) bound copies of the Final Report, thus revised, on or before May 31, 1933. The ten copies of the Final Report must be accompanied by a microfiche copy of tne Final Report suitable for use on a 3M Model 800 Microfiche Reader-Printer. A.3.5 Standard Operating Procedures. Sampling, sample preservation and analytical methodology shall be conducted in ccnformance with the Division'5 Standard Operating Procedures and EPA's Methods for Chemical Analysis of Water and Wastes, or other references approved oy the Division. A list of,_the fisld and laboratory methods used in this study shall be included in an appendix to the draft Final Report and Final Report. The field methods shall include a list of instrumentation and sampling techniques as well as sample handling, storage, and preservation. A.3.6 Palis. The diagnostic data collected and developed under this project shall be keyed to disk or tape, or punched on cards, so that it can be entered into the Division's Pond and lake Information System (PALIS). The Grantee should contact the Division's Electronic Data Processing Section in Westoe-rough prior to the transfer of data and/or for specific information on format. A.4 Milestone Schedule. The trork shall be performed by the Grantee in accordance with the Project Milestone Schedule set forth in Section II of this Attachment. The first month of the schedule shall begin with the date of commenceinsnt of this Agreement.