fuel* *33oil
FINAL REPORT
Diagnostic/Feasibility Study LAKE BOON i Towns of Hudson/Stow, MA I I I I I I I I I I I FINAL REPORT I DIAGNOSTIC/FEASIBILITY STUDY i LAKE BOON • Hudson and Stow, Massachusetts i August 1987
Camp Dresser & McKee Inc. in association with i IEP, Inc. i i i i i i i i I TABLE OF CONTENTS
I SECTION CONTENTS PAGE NO.
SUMMARY I 1.0 INTRODUCTION 1-1 2.0 DIAGNOSTIC STUDY 2-1 I 2.1 General Description and Morphometry 2-1 2.1.1 Lake Boon Watershed 2-1 2.1.2 Public Access 2-2 2.1.3 Morphometry 2-5 I 2.1.4 History 2-5 2.1.5 Soils and Geology 2-9 2.1.6 Land Use 2-11 I 2.1.7 Wastewater Disposal 2-18 2.2 Limnologic Data 2-21 2.2.1 Lake Boon Water Quality 2-21 I 2.2.2 White Pond Water Quality 2-37 2.2.3 Phytoplankton 2-38 2.2.4 Aquatic Vegetation 2-42 I 2.2.5 Sediment Sampling 2-46 2.3 Hydrologic and Nutrient Budgets 2-49 2.3.1 Hydrologic Budget 2-49 I 2.3.2 Nutrient Budget 2-56 2.3.3 Trophic Status 2-61 I 3.0 FEASIBILITY STUDY 3.1 Introduction 3-1 I 3.2 Technology Identification and Screening 3-1 3.2.1 Reasons for Rejection of Alternatives 3-3 I 3.2.2 Alternatives for Further Consideration 3-6 3.3 Final Options 3-12 3.3.1 Option 1: Sewering and Dredging 3-12 3.3.2 Option 2: Weed Screens, Public Education, I and Septic System Measures 3-12 3.3.3 Option 3: Weed Harvester, Public Education and Septic System Measures 3-20 I 3.3.4 Option 4: Weed Harvesting, Limited Weed Screens, Public Education, and Septic System I Measures 3-22 I I I I I TABLE OF CONTENTS (continued)
I SECTION CONTENTS PAGE NO,
3.4 Proposed Project 3-23 I 3.4.1 Description 3-23 3.4.2 Cost Estimate 3-27 3.4.3 Schedule 3-27 I 3.4.4 Public Participation 3-27 3.4.5 Monitoring Program 3-30 3.4.6 Environmental Evaluation 3-30 I 3.4.7 Recreational Plan 3-31 I APPENDIX I I I I I I I I I I I I I * LIST OF FIGURES
I FIGURE NO. TITLE PAGE NO. M 1-1 Watershed Delineation 1-2 • 2-1 Sampling Stations, 1985-6 2-3 • 2-2 Public Access 2-4 2-3 Water Depth 2-6 • 2-4 Surficial Geology 2-10 2-5 Watershed Soils 2-12 | 2-6 Watershed Land Use 2-17 — 2-7 Sampling Stations 2-22 " 2-8 Phosphorus 2-30 • 2-9 Transparency 2-39 2-10 Phytoplankton 2-40 • 2-11 Aquatic Plant Distribution 2-43 2-lla Aquatic Vegetation Percent Coverage 2-45 | 2-12 Sediment Thickness 2-47 _ 2-13 Precipitation 2-52 • 2-14 Trophic State 2-63 • 3-1 Effect of Final Options on Trophic Status 3-24 i i i i i i i I LIST OF TABLES
I TABLE NO. TITLE PAGE NO, I 2-1 Morphoroetric Data 2-7 2-2 Areas of Generalized Soil Types 2-13 • 2-3 Soils of the Lake Boon Watershed 2-14 2-4 Land Use 2-16 • 2-5 Lake Boon Water Quality, Summary, 2-23 m DWPC, 1979-1980 I 2-6 Aquatic Macrophyte Survey 2-44 2-7 Sediment Analysis 2-50 | 2-8 Hydrologic Budget 2-51 2-9 Year of Study Hydrologic Budget 2-55 • 2-10 Nutrient Budget 2-57 M 3-1 Technology Screening , 3-2 3-2 Second Alternative Screening 3-7 • 3-3 Cost Estimates of Final Options 3-24 3-4 Cost Estimate of Proposed Project 3-28 • 3-5 Implementation Schedule 3-29 i i i i i i i i I I SUMMARY I 1. Lake Boon is a diverse waterbody with two larger open water basins, and several shallow, vegetated basins. The lake is a well-used recreational resource for the people of Hudson and Stow, supporting a Town bathing I beach and swimming, boating, and fishing activity throughout the year. I 2. Dense growth of floating leaved and submerged aquatic plants interfere with recreation in the shallow eastern basins of the lake, and shallower areas of the second basin. The primary nuisance species is Camboba, not a I native of the area. Water milfoil is another nuisance species present, but it does not appear to have expanded since the EWPC (1981) study. I However, it has the potential to expand rapidly. I 3. Moderate to high populations of blue-green algae occur during the summer, contributing to borderline transparency problems. Dissolved oxygen is limited in deeper waters during summer stratification, but is not of I sufficient magnitude to impact fisheries or phosphorus recycling. No I problems with bacterial contamination were noted. 4. Lake Boon has a low flushing rate with limited water inflows due to the I large volume of the lake compared to the area of the watershed, and the prevalence of groundwater storage in the watershed area.
I 5. The major controllable sources of phosphorus from the Lake Boon watershed is surface runoff from shoreline residential properties and nutrient I export from shoreline septic systems. The sandy character and high water I table of shoreline soils limit their function to attenuate phosphorus. 6. To address the main problem of dense aquatic vegetation and the secondary problem of reducing phosphorus in the water column, various combinations I of alternatives were developed. Four options were then evaluated in more I detail and the proposed project was then selected. I I I I I 7. The selected option includes the following components: a. One year only contracted hydroraking to provide interim relief from I nuisance aquatic vegetation. It may also have limited carryover benefits since hydroraking removes the roots of aquatic vegetation as well as upper portions. This will cost approximately $38,000. If I funded by the DEQE Clean Lakes Program at 75%, the Town's share will I be $9,500. b. The purchase of a medium sized weed harvester to be maintained and I operated by the towns of Hudson and Stow on an annual basis. This harvester will cut and remove nuisance aquatic vegetation, improving the recreational potential of Lake Boon. The weed harvester will cost I about $50,000, of which $12,500 is the Towns' share. Annual costs, which are not fundable under the Clean Lakes Program, will be I approximately $18,000. I c. The implementation of a watershed management plan to include a septic system pumping program; revisions to the Towns' by-laws on cesspool conversion; and a public education program. This portion of the I project is vital to the preservation of Lake Boon. Without it, the lake will deteriorate to a "pea soup" condition. This portion of the I project will cost $30,000 total, with $7,500 being the Towns' share. There will also be an annual cost of up to $10,000 for the first few I years of implementation. d. A 3-year monitoring program as required by the DEQE Clean Lakes I Program to determine the effectiveness of the project. This is estimated to cost about $50,000 total, of which $12,500 is the Towns' I share. 8. The total cost of the project is $168,000 including the state required I monitoring program, with the Towns' share $42,000. Annual costs will be I an additional $28,000. I I I 9. This project will not return Lake Boon to a "pristine" condition. However, without these preservation efforts, nuisance aquatic vegetation and algae blooms will increase rapidly over the next few years to a point where recreation is severely inhibited. This project should be implemented as soon as possible if the lake is to be preserved. I I 1.0 INTRODUCTION I Lake Boon is located in Hudson and Stow, Massachusetts (Figure 1-1), tributary to the Assabet River. The watershed includes land in the both towns, and is dominated by forest with dense residential I development surrounding the lake. I Historically, Lake Boon has been an important recreational resource for the residents of Stow and Hudson—swimming, boating, and fishing I are all popular activities. At one time, the cottages surrounding the lake were popular for summer vacations of Boston area residents, however, most I have been converted to year-round homes. In more recent years, the condition of the lake deteriorated because I of increased algae and aquatic plant growth, interfering with established recreational pursuits. Initial attempts to control weed I growth began in the 1960fs with chemical and mechanical controls. These were only marginally successful, and continued problems led to a 1978 study by the Metropolitan Area Planning Commission (MAPC). "A I Management Program for Lake Boon: Interim Report" was issued by MAPC in January 1979, and addressed land use and zoning issues in the I watershed. In 1979-1980, the Massachusetts Division of Water Pollution Control I (DWPC) conducted a year-long study of the lake. This effort included water quality monitoring, hydrologic and nutrient budgets, and an I analysis of potential management/restoration strategies. However, restoration measures for the lake were not fully evaluated. The I present study is designed to update the findings of the DWPC study, and to provide a more detailed analysis of feasible restoration techniques- The study began in the summer of 1985, and was partially I funded through the Massachusetts Clean Lakes Program (Chapter 628). I I I 1-1 I V.j#—*.:.*r~
CAMP DRESSER & FIGURE 1-1 SCALE IN FEET LAKE BOON DIAGNOSTIC FEASIBILITY STUDY McKEEINC. In association with TOWNS OF HUDSON AND STOW WATERSHED (D 0 500 1000 2000 IEP, INC. DELINEATION MASSACHUSETTS I Many of the requirements of the study are technical, and so I the use of a considerable amount of technical terminology is necessary. For reference, a glossary of terms is provided in Appendix A. Metric units I are required by contract, but English equivalents are given where possible. I I I I I I I I I I I I I I I 1-3 I I I 2.0 DIAGNOSTIC STUDY
I 2.1 GENERAL DESCRIPTIONS AND MORPHOMETRY I These descriptions represent subtasks A.3.1.a - g of the substate agreement, and give an overview of the lake and its watershed, as I well as forming a basis for further analyses. f 2.1,1 LAKE BOON WATERSHED Lake Boon is a 66 hectare (163 acre) lake located in the Towns of I Hudson and Stow. The watershed of Lake Boon includes 684 hectares (1690 acres) and ranges in elevation from 60 meters (190 feet) at the lake to 85 meters (280 feet) at the height of land. The watershed-to-lake I area ratio is 10.4:1. This is fairly small and suggests the influence of in-lake processes and low flushing rate in determining the character of the I lake. Much of the watershed is characterized by level or slightly sloping, I sandy areas with dry oak forests and red maple swamps. The lake can be divided into several basins for discussion purposes. The first basin is the deepest, northernmost basin, with the outlet I exiting on the west side. The second basin is intermediate in depth, located centrally in the lake and watershed. The third and fourth I basins, including the "stumps" area, are at the east end of the lake, and consist of shallow areas which were not part of the original I lake, but are flooded wetlands added to the lake when the water level was raised in the 1800's.
I The outlet is at an earthen dam over which Barton Road passes at the northwest corner of the lake. The structure consists of a 48" wide I concrete weir structure with about a three foot drop to a circular corrugated metal culvert, which empties on the west side of Barton I Road. Water levels may be adjusted one to three feet by flash boards I I 2-1 I I at the weir. The outlet stream consists of a marsh area, about 200 I feet wide, which empties into the Assabet River about 600 feet downstream of the lake outlet.
I inlet streams to Lake Boon are remarkably limited, hinting at the importance of groundwater in sustaining the lake. The sampling I stations for the lake are shown on Figure 2-1. The largest inlet (sampling station 4) enters the lake in a cove on the south side of I the second basin. Two minor inlets that flow only part of the time enter the lake at the east end (stations 3 and 6).
I No flow was ever observed during the course of our study at station 6. Given the buried condition of the culvert under Sudbury Road, and a the well developed upland vegetation along the "channel" west of Sudbury Road, it is doubtful that surface flows have entered the lake i here in recent years. Both stations 3 and 6 drain large wooded swamps upstream of the lake.
I White Pond, a natural kettle hole pond, is located to the southeast of Lake Boon (Figure 2-1) and was sampled during this study (Station i 7) because of the potential hydrologic connection between the two water bodies. White Pond has no surface inlets or outlets, and is maintained as a water supply by the Town of Maynard. Although White i Pond and its drainage area have been included in the watershed delineation for Lake Boon (EWPC, 1981), it is doubtful that this area a contributes water to Lake Boon as discussed in later sections. i i 2.1.2 PUBLIC ACCESS Lake Boon has public access at two points as shown on Figure 2-2. One is an unpaved boat ramp located off Sudbury Road in the southeast i portion of the lake. Another is the Stow Town beach off Sudbury Road on the east side of Lake Boon, which is also available for public i use. The Town beach does not have a formal boat launching area. The I i 2-2 i I I I I t t I I I t I I 1 I I
I SCALE IN FEET LAKE BOON CAMP DRESSER 4 FIGURE 2-1 DIAGNOSTIC FEASIBILITY STUDY McKEEINC. in association with 0 600 1000 2000 TOWNS OF HUDSON AND STOW SAMPLING STATIONS I CAMP DRESSER & McKEE INC. I in association with I IEP, INC. I LAKE BOON I Diagnostic Feasibility I Study TOWNS OF I HUDSON AND STOW I MASSACHUSETTS I I NORTH I SCALE IN FEET I 0 400 800 1200 I FIGURE 2-3 I WATER DEPTH I (IN METERS) I I I I I I Table 2-1 Morphometric Data I Area 163 acres 66 ha Maximum Depth feet 23 feet 7.0 m I Mean Depth 10.7 feet 3.3 ID I Volume 74,700,000 ft' 2,110,000 m: Watershed Area 1,440 acres 533 ha I Maximum Length 10,300 feet "3,140 m Maximum Vidth 1,640 feet 560 m I 9,530 m Shoreline Length 31,300 feet I Development of Shoreline 3.3 I Watershed to Lake Area Ratio 8.8 t I I I I I I I I land around 1660. Boon lived in the area until 1676 when he was t killed near the pond. In the 1840's, Amory Maynard purchased land on the Assabet River and I built a dam for his sawmill. In 1847, Boston searched for water supplies to meet growing population needs. Boon's Pond was I procured for this purpose, however it was never used. A payment for the water supply taken was received in the form of a dam built on f Bailey's Brook at Barton Road. This action enlarged Boon's Pond into a sizeable lake, now called Lake Boon. I Several summer cottages were built followed by many more as the lake became a center of recreation. Around the turn of the century* the I steamer, "princess" was in operation on the lake, bringing commuters from their summer cottages to nearby railways. Lake Boon was the I site of many parties and was used frequently by canoeists and rowboaters. I Although White Pond is located within the Lake Boon watershed, it has no known surface water connection to Lake Boon. No inlets or outlets I are known to exist, however, a ground water interaction between the two bodies of water is possible. Prior to 1889, White Pond had a large commercial ice cutting operation functioning on its shores, 0 according to Maynard Town Historian Ralph Sheridan. An ice house was situated next to the pond near an old railroad. In the mid 1880's I the Town of Maynard made an application to the Massachusetts legislature to acquire white Pond as a drinking water source to supply the Town's growing t population. A bill was passed on May 25, 1888 giving the rights of the pond to the Town of Maynard. By 1889, Maynard's water supply i system was completed and use of White Pond began. In response to the droughts of the 1960's Maynard managed to secure i an unused well inside the united States Army Reservation and pumped water from the well into White Pond, In 1965, the Maynard Public t Works Department leased the "Quirk Well" off of Old Marlborough Road i i 2-8 i I to use to pump into White Pond. Eventually in 1967 the Town took the well and land around it by eminent domain. Currently a pump house t next to White Pond pumps water from the pond which then enters a gravity I fed distribution system. In the 1950's and 1960's the permanent population continued to grew 1 on the shores of Lake Boon. Residents became aware of the increased aquatic plant growth which interfered with recreational activities. Weed control was attempted in small coves with an experimental 1 chemical treatment in the early 1960's. This attempt was unsuccessful and drew objections from residents with drinking water i wells on the shore. Next, the Lake Boon Commission purchased a weed harvester and used it several times to cut back the aquatic plant I growth. According to Dick Gelpke, who operated the harvester, these attempts were unsuccessful. Inadequacies of the collection device allowed cut plant pieces to float away and reroot. Since the 1960's I no aquatic plant management has been attempted. f Current recreational uses at Lake Boon include fishing, swimming, and boating. These activities are pursued at many private beach and dock areas I associated with cottages, and a public swimming beach on the first basin. Ice fishing is popular in the winter whereas motor boating and swimming are I probably the most popular summer activities. I 2.1.5 SOILS AND GEOLOGY Surficial geology of the Lake Boon watershed is shown in Figure 2-4. 1 The major glacial deposit in the watershed is the outwash plain. This area is characterized by low topography and sandy soils, infiltration of rainfall on these deposits is high with limited I surface runoff. Various other types of stratified sand and gravel deposits are found in the watershed including ice channel fill, karoe I plain, and kame terrace. These deposits are all coarse-grained with I high groundwater potential. I 1 2-9 I WATERSHED BOUNDARY f~] OUTWASH PLAIN C3 WATER E^ WETLANDS ETT?| BEDROCK OUTCROPS i&ral GROUND MORAINE ES53 ICE CHANNEL FILLING ESS KAME PLAIN UUPIII KAME AND KAME FIELD DRUML1NS - LAKE BOON CAMP DRESSER & FIGURE 2-4 SCALE IN FEET DIAGNOSTIC FEASIBILITY STUDY McKEE INC. SURFICIAL TOWNS OF HUDSON AND STOW in association with 0 500 1000 2000 MASSACHUSETTS IEP, INC. GEOLOGY I Ground moraine and drumlin till deposits are found at the southern I edge of the watershed. In contrast to stratified deposits, these deposits are compact and composed of a variety of grain sizes which I limit infiltration and increase surface runoff. Swamp deposits are found in depressions and along stream valleys in 1 the watershed where partially decayed organic matter has accumulated. These areas are frequently characterized by groundwater I discharge. The dominant soils of the Lake Boon watershed (Figure 2-5, Table 2-2) I are Hinckley and Windsor. Hinckley is most prevalent to the north and east of the watershed, while Windsor is found south of the lake. I Both of these soil series are well drained to excessively drained sandy soils. Paxton Series is the third most common soil type in the I watershed, formed in areas underlain by glacial till. Minor areas of other soil types include two gravel pits, one small filled area, and small pockets of Freetown and Scarboro muck located in the swamps. IV The Natick Laboratory Military Reservation is in the north of the I watershed. Soil mapping was completed for the reservation in November, 1985 by the U.S. Soil Conservation Service. This portion I of the Lake Boon watershed exhibits a great variety of soil types with the mucks and Hinckley soils being the most prevalent. Descriptions and limitations of soils found in the watershed are I listed in Table 2-3. I 2.1.6 LAND USE The land use data for the Lake Boon watershed (Table 2-4, Figure 2-6) I have been updated from the 1979 Study conducted by the Division of Water Pollution Control. From field checks, it was found that the I forested land in the watershed has decreased 8% since 1979 and that residential land has increased by the same amount. Industrial land I has also increased along Main Street and Parmenter Street to make up I I 2-11 I 1 FREETOWN AND SCARBORO MUCKS 2 HINCKLEY, MERRIMAC, SUDBURY, WINDSOR 3 DEERFJELD, PIPESTONE 4 BIRCHWOOD. PAXTON, POQUONOCK. RlDGEBURY, TiSBURY, WOODBRIDGE 5 CHATFIELD/HOLLIS 6 GRAVEL PITS 7 UDORTHENTS I WATER LAKE BOON CAMP DRESSERS FIGURE 2-5 SCALE IN FEET DIAGNOSTIC FEASIBILITY STUDY McKEE INC. TOWNS OF HUDSON AND STOW in association with WATERSHED D 0 500 1000 2000 IEP. INC. d MASSACHUSETTS SOILS 1 1 1 1 Table 2-2 Lake Boon, Areas of Generalized Soil Types Soil Types Acres Hectares 1 - 1 1 132 53 8% 2 90 365 53* I 3 50 20 3% 4 284 115 17% I 5 95 38 6% 1 6 4.0 1.6 >1% 7 4.0 1.6 >1% Water 218 88 13% Total 1,690 684 100% Potential of Reason for Hydrologic Soil for Septic Limitation Soil Name Class Texture Permeability Location System Use Ratinj Birchwood fine sandy loam rapid surface to two pockets in very low slow percolation over sandy loam slow substratum south of rate, high water watershed table Chatfield B friable loam with rapid one pocket medium depth to rock, /Hollis C/D with rock outcrops Southwest of slope State Forest Deerfield loamy fine sand over very one pocket south- high water table coarse sand rapid west of Marlbo- low Poor filter rough State capacity Forest Freetown Muck decomposed organic moderate small pockets very low water table at material over loamy to throughout surface mineral material rapid watershed Gravel Pits areas of excavation none one in North of N/A N/A unweathered sand & Sudbury Road gravel Hinckley gravelly sandy loam very Dominant soil medium to slope over loose stratified rapid North of Boons very high sands and gravel Pond in watershed Merrimac friable fine sandy rapid Pockets in Natick very high none loam over stratified lab reservation sand Paxton friable sandy loam moderate large pockets on very low slow percolation over firm fine sandy surface to outskirts of rate, stony, loam slow sub- watershed slope stratum Table 2-3 (continued) Pipestone loose loamy sand rapid one pocket south- high high water table west of Marlbo- rough State Forest Poquonock loose sandy loam rapid surface one pocket in very low slow percolation over firm sandy to slov sub- southwest rate, stony, loam stratum slope Ridgebury loose sandy loam rapid surface one pocket in very low slow percolation over firm sandy to slow sub- southwest rate, high water loam stratum table, stony Scarboro Muck mucky sandy loam very rapid one pocket in very low water table at over stratified south along the surface sand Maine & Boston RR Sudbury fine sandy loam rapid pockets in Natick low high water table over stratified lab reservation sand Tisbury friable very fine moderate pockets in Natick low high water table sandy loam over lab reservation stratified sand Udorthents varied (disturbed rapid to slow one small pocket variable variable soils) in Vest Vindsor loose loamy fine rapid dominant soil medium to slope sand south of Boons very high in watershed Voodbridge loose fine sandy moderate along southwest very low slow loam overfine surface to border of water- percolation sandy loam slov substratum shed rate, high water table slope Note: soils data adapted from Soil Conservation Service. Application of these data at specific sites is not appropriate without site-specific mapping. 1 1 E Table 2-A Lake Boon Land Use I ^^ Area Land Use Type (acre) (ha) % of Watershed 1 Forest 1061 429 63% Residential 301 122 1 Industrial 49 20 1 Wetlands 31 13 2% Open Land 30 12 1 Water 218 88 13% 1 TOTAL 1690 684 loo^: 1 1 1 1 1 1 1 1 1 1 F FORESTED 0 OPEN LAND R RESIDENTIAL i INDUSTRIAL & WETLAND LAKE BOON CAMP DRESSER & FIGURE 2-6 SCALE IN FEET DIAGNOSTIC FEASIBILITY STUDY McKEE INC. TOWNS OF HUDSON AND STOW in association with WATERSHED dD 0 50 100 500 MASSACHUSETTS IEP, INC. LAND USE I 3% of the total watershed. For a more detailed description of land I use, and information about zoning in the watershed area, the reader is referred to DWPC (1981) and MAPC (1979). Non-point source phosphorus loading as estimated from land use is discussed in the nutrient budget I section. I 2.1.7 WASTEWATER DISPOSAL I Background The Division of Water Pollution Control, in conjunction with I Environmental Devices Corporation, conducted a "septic snooper" survey along the shoreline of Lake Boon in August, 1979. This survey found I areas of high inorganic (conductance) background levels along the shore near Pine Point Road, Hunter Avenue, and Worcester Avenue. An I area of high organic (flourescence) background concentration was also observed off of Worcester Avenue. Four apparent septic leachate plumes were sampled off Pine Point Road, one of which showed high I nutrient concentrations. Five apparent plumes were sampled along Hunter and Worcester Avenues, two of which had elevated nutrient I concentrations, and one showed high fecal and total coliform levels. I In all, twenty-seven "plumes" were sampled around the lake, nine of which (33%) were located off of Pine Point Road and Hunter and Worcester Avenues. However, three of these nine "plumes" which showed I high Kjeldahl-nitrogen and total phosphorus values may have been I caused by bottom sediments (DPWC, 1981). The Boards of Health in the towns of Hudson and Stow were contacted to obtain available information on septic systems in the vicinity of Lake I Boon in their respective towns. Frank Krysa, Health Agent in Hudson, indicated that the Hunter Avenue and Worcester Road areas, in I particular, were the worst locations for problems with septic systems. Jack Wallace, Stow Health Agent, related that Pine Point Road was the I area with the most complaints about septic systems. Both cited the I I 2-18 I I Of the total of 537 properties identified, about 35% of homeowners I responded, (Stow - 40% and Hudson - 30%). The following results are based on the assumption that all the lots have residences on them, whether seasonal or year-round. Although the response is essentially I a self-selected sample, the extrapolations provide useful information I regarding possible influent sources to Lake Boon. Of the respondents, 47% pumped their system regularly (Stow 52% and I Hudson 40%), 13% never pumped (Stow 12% and Hudson 13%), while 29% only pumped when and if there were problems (Stow 29% and Hudson 29%). I 10% of the respondents had new systems and therefore did not pump yet. This implies that only half of the residents around the lake are I adequately maintaining their systems. The remainder deal with their systems when problems occur. However, according to the respondents, I only a small percentage (8%) reported any problems with the systems. These problems included odors, back-ups, slow running toilets and drains, and overflowing systems. More than a quarter of the total I respondents (27%) have cesspools (Stow 30% and Hudson 23%). I Finally, the questionnaire sought to determine what additives were placed in the septic systems; 24% of respondents use detergents I containing phosphates and 32% use commercial preparations in their septic tanks. I The state of repair and efficiency of the septic systems, and the additives placed in the system are important when considering possible I sources of contamination of the lake. An estimate of phosphorus loading derived from septic systems is included in the nutrient budget I section. I I I I 2-20 I I I 2.2 LIMNOLOGIC DATA 2.2.1 LAKE BOON WATER QUALITY I Water quality was monitored seasonally, over the course of a year during the present study to update and supplement the data collected I during the more intensive DWPC (1981) study. Sampling stations (Figure 2-7) were at similar locations for both studies. The results I of all analyses are included in Appendix A. A summary of EWPC data is listed in Table 2-5. I Sampling runs were conducted on 10/29/85, 1/28/86, 4/8/86, and 7/29/86. The lab reports may be found in Appendix A. The location I and characteristics of each of these stations are described below, I followed by a discussion of the data collected. As shown on Figure 2-7, the in-lake stations in Lake Boon are #1 and #2. The in-lake station in white Pond is #7. White Pond seems to have I no surficial inlets or outlets. The wetlands entering the lake were apparently cut off by man-made embankments. Station 1 is six meters I deep. Station 2 is 3 meters deep, and Station 7 is ten meters deep. Stations 3, 4 and 6 are inlets, and Station 5 is the outlet. Station I 3 is in the southernmost cove of the "stumps" basin of Lake Boon. It flows in from a vast swamp in the U.S. Military Reservation, under Sudbury Road, and then through a red maple swamp to the lake. A new I driveway has cut off this inlet where it enters the lake. A culvert was installed to permit drainage, but it was filled in by sand eroding I from the driveway. This may impede flow to some degree, although the I inlet was dry only during the first sampling round. Station 4 is located in the southern portion of the second basin. It flows from the Boston and Maine Railroad, under Parmenter Road, and I under Main Street into the cove. The stream was generally 6 to 8 feet I wide and 2 to 3 inches deep during sampling. I I 2-21 I I conversion of older seasonal summer cottages to year-round residences I as the predominant reason for problems. Health Department records on septic system installations, repairs, and I written complaints were reviewed in the two towns. In both, the earliest records date back to about 1964. The Stow files revealed I that out of about forty houses on Pine Point Road, only four lots had records of septic system installation/repair since 1967, and there I were two recorded instances of overflowing systems. Hudson records showed that twenty-two of eighty-six house lots (26%) along Worcester Avenue and Hunter Road had records of installation/repair since 1964. I There were no documented septic system failures in the Hudson files. I Assessors maps of the shoreline areas around Lake Boon in Hudson and Stow were obtained to determine the location of house lots within 300 I meters of the lake. This information was used to compile a mailing list for the questionnaire that was used to obtain further information I on septic systems. I Description and Results of Questionnaire The septic system survey (See Appendix A) was mailed to property I owners and residents around the lake and requested the following information: I 1. Address and length of residence 2. Age of house I 3. Number of residents 4. Type, age, location and condition of septic system I 5. Maintenance procedures and regularity of pumping 6. Problems encountered with the systems 7. Detergent used I 8. Source of water I 9. Water-related appliances I I 2-19 I I I I I I I I I I I I I I I I I SCALE IN FEET LAKE BOON CAMP DRESSER & FIGURE 2-7 DIAGNOSTIC FEASIBILITY STUDY McKEE INC. in association with 0 500 1000 2000 TOWNS OF HUDSON AND STOW SAMPLING STATIONS I 3) MASSACHUSETTS 1EP, INC. 1985-1986 I Table 2-5 Lake Boon Water Quality Summary, DWPC, 1979-1980 1A 1C 2A 2C 4 5 Ei range 8.6-6.4 7.2-6.6 7.4-6.3 7.6-6.9 6.9-5.6 8.2-6.3 mean 7.3 6.7 7.0 7.1 6.3 7.1 Conductivity range 104-85 106-78 102-87 106-92 86-60 100-88 mean 96.5 95.6 95.5 99.5 72 95.2 Chloride range 21-18 31-18 31-8.0 22-19 13-7.0 21-19 mean 20 24 20 20 10.4 19.6 Total Hardness range 17-14 20-14 17-14 17-15 15-11 17-13 mean 16 16.3 16 16 12.8 15 Total Alkalinity range 12-7 15-9 12-8 12-9 15-3 13-7 mean 10 11.6 10.2 10 6.8 10 Total Solids range 186-54 180-54 170-44 76-54 98-4 192-50 mean 86.6 85.3 88.6 67.5 62 92 Suspended Solids range 2.0-0 10-0 4.0-0 4.5-0 4.0-0 2.5-0 mean 1.0 3.2 1.8 1.6 1.9 1.1 Total Iron range 0.10-0.00 0.25-0.00 0.69-0.06 0.35-0.04 0.29-0.05 0.12-0.00 mean 0.06 0.08 0.19 0.17 0.66 0.06 Total Manganese range 0.04-0.00 0.49-0.01 0.06-0.00 0.12-0.00 0.24-0.05 0.04-0.00 mean 0.01 0.2 0.03 0.05 0.11 0.02 Table 2-5 Lake Boon (continued) Parameter •Station- 1A 15 2C Total Phosphorus range 0.10-0.03 0.09-0.00 0.15-0.03 0.07-0.04 0.11-0.02 0.15-0.01 mean 0.06 0.06 0.06 0.05 0.06 0.06 Total Kjeldahl range 0.88-0.65 1.3-0.59 0.80-0.48 0.81-0.43 0.74-0.29 0.91-0.37 mean 0.77 0.82 0.64 0.60 0.52 0.58 Nitrite range 0.2-0.0 0.1-0.0 0.1-0.0 0.1-0.00 0.5-0.2 0.6-0.0 mean 0.4 0.06 0.06 0.05 0.38 0.15 Ammonia N range 0.12-0.01 0.13-0.00 0.12^0.00 0.20-0.01 0.03-0.00 0.14-0.06 mean 0.06 0.05 0.04 0.12 0.01 0.05 Organic N range 0.87-0.53 1.27-0.46 0.75-0.42 0.80-0.23 0.73-0.23 0.84-0.29 mean 0.71 0.76 0.59 0.49 0.51 0.50 Total Coliform range 90-<5 1600-<5 3000-220 740-25 mean 23.3 273.3 985 97.2 Fecal Coliform range <5 900-<5 880-<5 30-<5 mean <5 155.0 223.7 8.3 Chlorophyll-A range 7.92-1.22 8.30-2.08 mean 4.68 4.85 Table 2-5 Lake Boon (continued) Parameter •Station- Secchi disk Transparency range 3.4-1.5 3.0-1.4 mean 2.6 2.0 Note: All concentrations are mg/1 except: pH~(std. units), conductivity (umhos/cm), coliforra (count per 100 ml), chlorophyll-a (mg/m ), and Secchi disk (m). I Station 6 is located in the northern cove of the "stumps" basin. The stream comes from a vast swamp in the U.S. Military Reservation, tinder I Sudbury Road, and into the lake. This inlet often had no apparent flow, but did have stagnant water which was rust colored. The muck at I the mouth of this inlet was deep (> 1m). I Station 5 is the outlet of the lake, which flows directly into the Assabet River. The outlet structure contains several flash boards I that could be useful in partially drawing down the lake. I An evaluation of the data is described below, I Dissolved Oxygen and Temperature Wide seasonal variations in water temperature influence a variety of biological and chemical water quality parameters including dissolved I oxygen. Vertical variation of water temperature is important because I temperature influences water density. During the summer months, increased solar radiation raises the water I temperature, especially surface waters. The warmer, less dense layer of water overlays colder, denser waters. Density differences limit mixing of upper and lower layers. In the summer, when water is I stratified into layers, low dissolved oxygen concentrations can result due to sediment oxygen demand and lack of oxygen mixing from surface I waters. I Extended periods of low oxygen are undesirable biologically and chemically. Aquatic life, including fish require oxygen for life processes. Nutrients can be released from bottom sediments into the I water column under low dissolved oxygen conditions, contributing to algae and clarity problems. Also, low dissolved oxygen concentrations I can cause offensive odors from hydrogen sulfide production. I I I 2-26 I I Dissolved oxygen measurements and temperature profiles performed at I each sampling date for in-lake stations indicate that Lake Boon is well oxygenated during most of the year. Station 1 showed strong thermal stratification during summer months in both studies. At I Station 1 at six meters depth, near anoxic (no oxygen) conditions occur during July and August. Station 2 is a much shallower basin (3 I m) and strong thermal stratification does not occur. Hypolimnetic oxygen levels generally exceed the 5 mg/1 standard guideline in the I rest of the year in both studies. In October, overturn had already occurred. In November, DWPC found that mixing had occurrd. During the winter sampling dates the normal pattern of inverse stratification I occurred with temperatures increasing with depth. Hypolimnetic oxygen concentrations in January were above the 5 mg/1 guideline for Class B I waters, implying that adequate oxygen was available for aquatic life I during ice cover. Nutrient Data I Phosphorus and nitrogen are essential elements for growth of algae and plants. Whichever of these is in lesser supply compared to demand is I the limiting nutrient, or the nutrient upon which the growth of algae/plants is dependent. In freshwater lakes, phosphorus is usually I the limiting nutrient. Nitrogen occurs in many different forms in water: organic nitrogen, I ammonia, nitrate, and nitrite. Sources of nitrogen in a pond are atmospheric from precipitation, nitrogen fixation by algae and inputs I from surface and groundwater drainage. Most nitrogen enters lake systems from terrestrial runoff. Nitrogen is a basic element vital to I the ecological balance of water. However, large amounts of nitrogen can lead to the proliferation of organisms such as algae. I Kjeldahl-nitrogen is a measure of ammonia and organic nitrogen. Recent sewage contamination, and decay of natural organic matter are I sources of Kjeldahl-nitrogen. Organic nitrogen pollution would be I I 2-27 I I suggested by Kjeldahl results greater than 1 ntg/1. Organic nitrogen I concentrations can be derived by subtracting ammonia values from total Kjeldahl values. No organic nitrogen pollution is evident at Lake I Boon from analyses from the present or historical studies. Ammonia is present naturally in waters due to the biological I degradation of organic matter. Larger amounts of ammonia usually do not stimulate excessive growth of aquatic life, but rather lead to I toxicity. Fish are especially susceptible to ammonia toxicity, although tolerance varies among species. Concentrations of ammonia greater than 0.02 mg/1 can be toxic for freshwater aquatic life {EPA, I 1976). Toxicity is dependent on pH as well as other variables such as temperature and ionic strength. Both studies of Lake Boon indicate I high ammonia levels, with no pattern of seasonality evident. Although these concentrations are elevated, no evidence of biological toxicity I has been noticed with other indexes (algal counts). Ammonia levels of greater than 0.02 mg/1 could be attributed to sewage inputs or anoxic I conditions, but cannot be directly traced in Lake Boon. Nitrate and nitrite are important components of the nitrogen cycle. I Nitrite is rapidly converted to nitrate during decomposition. Nitrate is the end product of aerobic decomposition of nitrogenous matter and I is readily available to plants in this form. Growing plants assimilate nitrate and convert it to protein. Common sources of nitrate are fertilizer, septic leachate, animal waste, automobile I exhaust, landfill leachate, natural soil organic matter, and I atmospheric fallout. Large concentrations of nitrate in combination with available I phosophorus can lead to nuisance algal blooms and dense roacrophyte stands. For domestic water supply 10 mg/1 nitrate nitrogen is the maximum recommended concentration for human health, (EPA, 1976). I Concentrations of nitrates below 90 mg/1 have no adverse effects on warm water fish (EPA, 1976). For eastern Massachusetts, 0.05 mg/1 is I considered the normal background level (MAPC, 1983). All data from I I 2-28 I I both studies of Lake Boon suggest that nitrate levels are normal for a I Massachusetts lake and should not be considered a nitrate toxicity problem. I Total phosphorus ranged from <0.01 to 0.30 mg/L, slightly higher than the ranges found by EWPC in unpolluted Massachusetts lakes, but within I the ranges found by COM in other developed lakes. The greatest concentrations of phosphorus were found at the eastern inlet (#3). I Figure 2-8 shows in-lake phosphorus data collected during the two studies. I The most significant form of phosphorus found in lakes is phosphate. Phosphate is a major nutrient required for plant and algal nutrition, I however, excessive concentrations can stimulate nuisance growth. Although phosphorus is not the sole cause of cultural eutrophication, I it is a key element required by freshwater plants, and generally is present in the least amount relative to demand. An increase in phosphate allows for the utilization by plants of other nutrients I already present. The phosphates can enter a lake system from several different sources including: sewage, industrial wastes, detergents, I fertilizers, and natural sources (rocks, soil and rain). As a general guideline for Massachusetts lakes, phosphorus I concentrations of greater than 0.025 mg/1 can contribute to nuisance aquatic growth (EPA, 1976). Phosphorus analyses are below problem I concentrations, however, CWPC data indicate average concentrations near problem levels (Figure 2-7). Whereas much variability is shown I in phosphorus concentrations, no seasonal patterns are evident from these data. Inlet stations in FIGURE 2-8 both studies do not indicate that large concentrations of phosphorus are entering the lake system I from the tributaries. I In-lake phosphorus concentrations measured during the present study were largely <.01 mg/1, within the range indicating oligotrophic I conditions (Wetzel, 1983). However, during the EWPC (1981) study, I I 2-29 I Figure 2-8A Lake Boon Phosphorus (mg/1) 1979-1960 LEGEND 0.14 1 \ 0.12 Sta. 1A 0.08-- - Sta. 1C j 0.06— ! | 0.04— Sta. 2A i i 0.02-- Sta. 2C Apr 24 Jun 06 Jul 17 Aug OB Nov 19 Feb 27 Mar 27 May 07 May 20 Jun IB Figure 2-BB. Lake Boon Phosphorus (m$1/1) 1985-1986 LEGEND 0.14- 0.12- 0.10- ~ 0.08-f- *— - Sta. 1C 0.06- H Sta. 2A 0.04- •^^ 0.02- , J\-^^:^.^:^-^-:^=ll:Il^ 1 Sta. 2C Oct 29 Jan 28 Apr 08 Jul 29 I concentrations of phosphorus averaged 0.06 rag/I, indicative of I mesotrophic to eutrophic conditions (Wetzel, 1983). Based on only four sampling rounds, there are insufficient data to conclude that Lake Boon has changed significantly in the five years between the two I studies. It is more likely that the four sampling rounds made during the present study are not representative of the in-lake conditions I over the whole year and/or meteorologic variability caused the year of I study to produce atypical water chemistry (Section 2.3.2). Iron I Iron is a trace element required by plants and animals to sustain life processes. Algal and plant growth can be limited by insufficient I quantities of iron especially under highly alkaline conditions. Iron plays a vital part in oxygen transport in all vertebrates and some invertebrate animals. Some forms of iron precipitate and can be I detrimental to fish and other aquatic life when suspended in water. Flocculants can settle on stream or lake bottoms destroying bottom I dwelling invertebrates, plants or fish eggs. Floes can also I consolidate to form pavement-like materials. Sources of iron pollution include industrial wastewaters, mine drainage waters and iron rich groundwaters. Iron concentrations I greater than 3.0 mg/1 for domestric and 1.0 mg/1 for freshwater life are considered high (EPA, 1976). All iron concentrations in both I studies are low enough to be of no danger to all forms of aquatic life. Levels of iron greater than 0.5 mg/1 are considered high for I Massachusetts lakes. Iron concentrations ranged from <0.02 to 7.2 mg/L, with the highest I levels found at stations #3 and #6, the eastern and northern inlets respectively. There was some difference between the concentrations I found at the bottom and surface of stations #1 and #2, the in-lake I stations, which during the same sampling runs showed some oxygen I I 2-31 I I deficit at the bottom. No difference in phosphorus concentrations was I found between the surface and bottom stations. Manganese is found in various salts and minerals and frequently is I found in association with iron compounds. Both plants and animals require this vital micro-nutrient. Plants use it to develop leaves I properly and to prevent yellowing. With domestic usage, large concentrations of manganese can cause staining of laundry and objectional tastes. Adverse effects of manganese may be intensified I when low concentrations of iron are also present. Manganese was measured only in the Division of Water Pollution Control's study and I should not be considered to be a problem in Lake Boon since I concentrations, were far below recommended levels. Suspended Solids, Dissolved Solids, Turbidity I Suspended solids are solid material in the water column that can be removed by filtration. Common sources of suspended solids are algae, I silt and clay particles. Erosional runoff results in high levels of suspended solids in water. Turbidity is a measurement of the clarity I of the water. Turbid water interferes with recreational activities and life processes of aquatic organisms. Swimming and diving can be dangerous in turbid waters with the possibility of unseen submerged I hazards. Fish and other aquatic life requirements can be altered due to the suspended materials in the water column or sedimentation to I the bottom. 1 Total suspended solids concentrations have generally been highest at inlet stations #3 and #6, with the highest concentration being 18 mg/L. Suspended solids greater than 5 mg/1 are considered problematic I (MAPC, 1983). However, Lake Boon suspended solids data from in-lake I stations do not indicate that water clarity is a problem. Dissolved solids are materials that cannot be filtered out of water. I Materials such as inorganic salts and small amounts of organic matter I I 2-32 I I which would remain in solution are included in this measurement. All I aquatic life must tolerate a range of dissolved solids concentrations in order to survive under natural conditions, but cannot tolerate I drastic changes in concentrations. Excessive dissolved solids are objectional in drinking water supplies due to physiological I effects and corrosion and encrustation of metallic surfaces. Dissolved solids concentrations ranged from 25 to 187 mg/L, well I within the 15,000 mg/L limit reported by EPA as unsuitable for most freshwater fish. They are also much lower than the EPA's drinking I water standard of 250 mg/1 (EPA, 1976), and are acceptable ranges without extreme variances for aquatic life in Massachusetts lakes. I The highest concentrations for both suspended and dissolved solids were found in samples collected on July 29, 1986. Turbidity I concentrations ranged from <2 (the detection limit) to 32 MTU. Levels were highest at station #6, the northern inlet, and station #3, the eastern inlet. Lowest turbidities were found at station 7, the I in-lake White Pond station. In contrast to total and dissolved solids concentrations, the highest turbidities were found during the January I sampling run. I Alkalinity and pH The buffering capacity of water is determined by the alkalinity and I reflects the stability of the pond's pH level. The pH and buffering capacity of a body of water have direct effects on aquatic organisms I and indirect effects on the toxicity and solubility of other compounds such as metals. A lake with high alkalinity resists I changes in pH. Often the alkalinity of a lake is influenced to a large degree by watershed characteristics such as depth of soils and I bedrock type. The Division of Water Pollution Control's 1981 study of Lake Boon I water quality found surface alkalinity for Station 1 averaged 10 mg/1 I I 2-33 I and surface Station 2 averaged 10.2 mg/1. Average alkalinities of 9.7 mg/1 and 8.6 mg/1 were found during this study at Station 1A and Station 2A. A general guideline of alkalinity values considers 20 mg/1 to indicate a well buffered lake (EPA, 1976). Considering inlet stations, alkalinity levels ranged from <1 to 16 mg/L in Lake Boon, below the 20 mg/L (minimum) level criteria used by EPA for aquatic life. This indicates relatively low buffering capacity for the lake and incoming surface streams. In particular, the eastern inlet station (13), and to a lesser degree the southern inlet station (#4), had very low levels of alkalinity. The pH value is determined by the concentrations of acids and bases dissolved in water. pH is the measure of the hydrogen ion concentration of a solution on an inverse logarithmic scale ranging from 0-14. A pH of 7 is neutral; less than seven is acidic whereas greater than 7 is alkaline. Most lakes have pH values between 6 and 9. The Division of Water Pollution Control's 1981 study found average pH values for Station 1A, Station 2A, inlet and outlet stations to be 7.3, 7.0, 6.3, and 7.1, respectively. Similar pH concentrations were found during this study. Although alkalinity values indicate low buffering capacity, measurements of pH have fluctuated within the expected natural range, implying that acidification is not currently a problem at Lake Boon. The one pH measurement of 5.7 at Station Z (Table Al) is by itself insufficient to indicate a pending problem. At these low alkalinity levels, however, LakeBoon is considered susceptible to changes in pH over time. Chloride and Conductivity Chloride is one of the major anions in water and sewage. Concentrations of chloride are influential in osmotic balances and ion exchange for aquatic life. Pollution sources, especially road salting, can modify natural concentrations and cause biological disruptions for aquatic organisms. 2-34 I In urbanized areas, roads are often salted heavily during winter I months to keep them free of ice. Chloride levels in Lake Boon indicate that road salting is not presently a pollution problem in this watershed. Concentrations of less than 20 mg/1 are low compared I to other Massachusetts lakes. I Conductivity is a measure of the ability of water to carry an electric current and is related directly to electrolytes in the water. I Dissolved solids are proportional to the conductivity levels. Pollution sources such as road salting and septic systems can increase conductivity levels. Both studies found low conductivity levels I compared to other Massachusetts lakes. Lake Boon's low conductivity levels indicate soft water with low levels of dissolved minerals in I the water column. I Bacteria The coliform bacteria group is used as an indicator of potential I wastewater contamination. Fecal coliform originate in the intestines of warm blooded animals. Total coliforms include fecal plus non-fecal I coliforms which originate in soil and decaying vegetation. Fecal bacterial counts should not exceed 200/100 ml (EPA, 1976). The I more fecal coliforms present, the greater degree of health risks associated with swimming, drinking or shellfishing. The IWPC analyses I showed problem levels at Station 2A and the inlet. Elevated fecal coliform levels occurred seasonally at Station 2A with highest counts I in July. The inlet station showed high fecal coliform counts throughout the season, however, with a peak in July. I The present study found high fecal counts only during July, On this date the counts were high in all stations whereas previous sampling I had not indicated any wide spread bacterial contamination. It is possible that the samples on this date were contaminated during I handling, or that the high counts may have been due to storm water I I 2-35 I I runoff. July 29 was the third in four consecutive rainy days. Total I coliform analyses from both studies reflect fecal coliform levels. Peaks in total coliform can be attributed to high fecal coliform plus I soil bacteria from rain runoff. I Transparency and Chlorophyll-a Measurements of biological, chemical, and physical parameters describe I the environment that influences the trophic condition of Lake Boon. The Secchi disk gives a physical measurement of the depth to which light penetrates the water column. Several factors affect Secchi disk I readings including water color, dissolved and particulate matter, phytoplankton (algae) and zooplankton densities, water surface and I weather conditions. I Chlorophyll a is a photosynthetic pigment found in all plants. Phytoplankton biomass and productivity can be estimated with this biological assessment. The relationship between chlorophyll a and I algal populations and densities aids in understanding nutrient loading in lakes. The water quality of Lake Boon can be best described by I comparing Secchi disk, chlorophyll a, algae, turbidity, and dissolved I and suspended solids analyses. Good to fair clarity is implied by Secchi Disk reading at Stations 1 and 2 in both studies. Readings are greater than the state minimum of I 4 feet (1.2 m) required for swimming areas (Commonwealth of Massachusetts, 1969) except at Station 2 in the summer, when readings I approached the four foot minimum (Figure 2-8). The lowest Secchi disk readings coincide with the highest chlorophyll a results suggesting I that reduced transparency is due to increased algal densities. Chlorophyll a results varied seasonally. In the summer, the peak I growth season of algae, chlorophyll a results were high reflecting the high counts of blue green algae, when algal populations were I increasing (spring) and decreasing (fall), chlorophyll a results were I I 2-36 I I con^ared with these environmental trends. The winter brings ice cover to Lake Boon and reduces light to algal populations. Chlorophyll a I 3 results reflect these changes. Chlorophyll a peaks of 16 mg/ta measured during the present study indicate mesotrophic lake conditions I (Wetzel, 1983). The peak concentrations measured during the EWPC (1981) study of 8 mg/m3 are indicative of borderline oligotrophic to I mesotrophic conditions. The fact that chlorophyll a peaks measured in 1979-1980 were about half of those measured in 1985-1986 is I nonconsistent with the lower phosphate concentrations and lower algal densities measured in 1985-1986. I 2.2.2 WHITE POND WATER QUALITY I White Pond is well oxygenated throughout the year, Hypolimnetic oxygen concentrations generally exceed 5 ffig/1, which is a guideline I used to indicate that adequate oxygen is available to support aquatic life and maintain the aesthetic quality of the water (EPA, 1976). Only in January does the dissolved oxygen level approach anoxic I conditions. A weak thermal stratification is evident in July, with decreasing temperature with depth. Aquatic life processes have an I adequate supply of dissolved oxygen year-round to meet their i requirements. A bathymetric map of the pond was not generated. Only a surface sample was collected at this station and comprehensive i temperature/dissolved oxygen profiles were not obtained. t In July excellent water clarity (6m) was noted. Tom Sheridan of Maynard Public Works reported infrequent algae problems. The last incidence of elevated algal populations occurred in 1983 and was i treated with copper sulfate. Microscopic examinations indicate that during most of the year algal densities had not reached nuisance i proportions. i i i 2-37 i 1 Species composition can have an influence on water quality. In I April algal counts reach a peak due to a bloonx of Dinobryon. This armored flagellate can cause a fishy odor and can clog filters or screens (Palmer, 1977). Low densities and the least diversity I occurred in January due to low solar radiation and ice cover. I Since White Pond is a public water supply, water quality is particularly important to public health and aesthetic qualities. I Maynard Public Works is responsible for maintaining good quality drinking water to Maynard residents. Occasionally turbidity has been a problem after rainstorms, according to Tom Sheridan of Maynard I Public Works. However, recent water quality has been high and no in-lake treatments have been conducted since 1983. Treatment in the I distribution system consists only of disinfection. I 2.2.3 PHYTOPLANKTON Phytoplankton are non-vascular, free-floating, photosynthetic I plants. These microscopic algae incorporate sunlight and nutrients to form plant matter, and exist as single cells, colonies or I filaments. Several factors affect distribution and abundance including concentrations of nitrogen and phosphorus, penetration and I intensity of light, and turbidity and suspended solids. Figure 2-9 shows transparency of the lake over the study. I Phytoplankton biomass and species composition are the best indications of water quality and trophic conditions (Vollenweider and I Kerekas, 1980). Both studies of biological productivity of Lake Boon exhibit similar seasonal trends (Figure 2-10). Elevations in algal I cell counts and chlorophyll a occur in July and August and the widest diversity of genera exists simultaneously. I Green algae is prevalent especially Spaerocystis and Chlamydomonas and other pigmented algae including Chrysococcus. A bloom of the I blue-green algae Anabaena also occurred. This bloom corresponded with I I 2-38 I Figure 2-9A Lake Boon Transparency (m) 1979-1960 LEGEND 3.0-f- a. | 5 Sta. 1 4*, 2.0- 1.5- 1.0-f- ' j 0.5— Sta. 2 Apr 24 Jun 06 Jul 17 Aug OB Nov 19 Figure 2-93. Lake Boon Transparency (m) 1985-1986 LEGEND 3.0- 2.5-- Sta. 1 2.o4- 1.5-- 1.0-- - Sta. 2 0.5-- Oct 29 Jan 28 Apr OB Jul 29 Figure 2-10A. Lake Boon Phytoplankton (cells/ml) 1979-1980 LEGEND ////jt'.A Diatom Blue-green 6reen l^il^ Flagellate Nov 19 07 Figure 2-1QB. Lake Boon Phytoplankton (cells/ml) 1985-1986 1400-r LEGEND 1200 W/7///\ Diatom 1000 Blue-green Green Other Oct 29 Jan 26 Apr OB Jul 29 I the highest chlorophyll-a and lowest transparency measured during the I study. However, no elevation of nutrient concentrations was noted on this date. Blue-green algae can fix nitrogen and are often I responsible for objectional odors and tastes. The DWPC data show similar community compositon but some different genera. f In the fall a depression in algal densities, diversities and chlorophyll a occurs which relates to the mixing layers of water. I Diatom populations are dominant in the fall, a typical pattern observed in many lakes. Winter brings the least photosynthetic activity of the year due to ice cover and decreased solar radiation. I A narrow range of diversity occurs with green algae the most common with frequent diatoms. The spring months bring increasing solar I radiation and water temperature which are more favorable conditions for algal populations. Densities and diversity increase with green I algae still most dominant. The dominant algae noted at Lake Boon by the DWPC in 1979 and 1980 I were the blue-green algae, Oscillatoria and Choroococcus. Several other phytoplankton also occurred in large numbers including the I diatom Tabellaria, a flagellete Uroglenopsis and an unidentified flagellete. These dominant algae did not occur regularly throughout I the year, but rather usually as "blooms" or population explosions. In 1985 and 1986, IEP found the dominant phytoplankton genera to be a blue-green alga, Anabaena, and two green algae, Spaerocystis and I Gloeocystis. The golden-brown algae Dinobryon also occurred frequently through the year of study. The phytoplankton numbers I measured in 1985-1986 were far lower than those measured in 1979-1980. Phytoplankton are useful indicators of lake fertility or trophic I condition. Certain genera of algae are indicative of nutrient concentrations in the water body. In both the DWPC and IEP studies, the dominant algae indicate eutrophic conditions (Wetzel, 1983). i Blue-green and green algae are commonly found in nutrient rich waters. i i i 2-41 i 1 I 2.2.4 AQUATIC VEGETATION A survey of the aquatic plants growing in Lake Boon was made on August 14, 1986. Figure 2-11 shows the distribution of the plants in 1 the lake; a complete list of plants is included in Table 2-6, along with an estimate of relative abundance of each by basin. The percent I coverage of aquatic plants is shown on Figure 2-11A. I In general, the plant species and distribution noted during the present study are similar to that documented by DWPC in 1979. Cabomba is the dominant nuisance species present. This plant is not I native to New England, but it has been introduced to many ponds in the region and often grows in dense underwater patches that detract I from recreational and wildlife values. I Cabomba is dominant in the third and fourth basins of the lake, whereas it has not been found in the first basin. Growth in the second basin appears to be highly variable from year to year. This I year, Cabomba is fairly sparse in the second basin except in the cove near Station 4 (Figure 2-11). Growth was more evenly spread I throughout the basin in 1979, and was noted in the central parts of I the basin during the water sampling round in October, 1985. A second potential nuisance species found in Lake Boon is water milfoil Myriophyllum heterophyllum. The only dense patch found in I 1986 was in the cove near the inlet at Station 4. Other than this area, water milfoil does not seem to have expanded its coverage since I the 1979 survey. I Aquatic plant growth in the third and fourth basins is dense, consisting of Cabomba along with native floating-leaved species such as yellow and white waterlily and watershield. These species I commonly form dense patches in shallow ponds in New England, especially in areas of flooded wetlands, which is the case with this I portion of Lake Boon. Unlike some of the introduced species, the I I 2-42 I CAMP DRESSER & McKEE INC. in association with IEP, INC. LAKE BOON LU Diagnostic Feasibility Study TOWNS OF HUDSON AND STOW MASSACHUSETTS NORTH SCALE IN FEET 620 1240 FIGURE 2-11 AQUATIC PLANT DISTRIBUTION August 14,1986 Table 2-6 Lake Boon, Aquatic Macrophyte Survey Genus/Species Common Name Occurrence by Basin 1 2 3 & 4 Brasenla schreberi Vatershield D Cabomba caroliniana Fanwort D D Chara sp. Musk-grass 0 C 0 Ceratophyllum sp. Coontail 0 Decodon sp. Swamp Loosestrife C Myriophyllum sp. tfater Milfoil D 0 Najas sp. Naiad D 0 Nitella sp. Stonewort D Nuphar sp. Spatterdock 0 0 Nymphaea sp. Vater-lily D Potomogeton amplifolius Pondweed 0 Potomogeton natans Pondweed 0 Potomogeton robbinsii Pondweed 00 0 tftricularia sp. Bladderwort C D a Dominant C = Common 0 Occasional KEY 0-25 25-50 50-75 75-100 ^ ^ /"^ C/5 O l11^ S o ^^ ^ I V^J ^* _. | » s 5' 80 5 S§ i CO CO ^ Q. to J^ 5 o g m ni SM a ;== =5 TI ^* i^^ J° < w 7; r, -. -<. m M O m 5 ^o « 5?SffiS 0 o V § Z, /^//T^r \ ^\ Hd pH\ (p-n1 *^*CD ^ m ± § Rgffi 171 H >i §P5' S w5 5*; " V J - O — ^/^ s: 5^ I < "• S 1 I wildlife value of these species is fairly high as they are important I sources of food for waterfowl and cover for fish (Martin et al, 1951). I Macrophyte growth in the first basin is sparse, dominated by Nitella, a macroscopic form of algae. At present, growth in this basin does not appear to present a problem for recreation as it is sparse and I low, confined to within a foot or so of the pond bottom. I 2.2.5 SEDIMENT SAMPLING Sediment thickness measurements were made at all test holes where f measured water depth was twenty feet or less. Most shoreline areas of the first and second basins showed little or no accumulated I sediment, with an exposed clean sand and gravel substrate (Figure 2-12). The eastern basins contain up to 12 feet (3.5 meters) or more I thickness of organic peat. These deposits are characteristic of wetland soils which most likely formed before the region was flooded by raising the dam in the 1800's. Little or no evidence of recent I sedimentation was noted. i On April 8, 1986, two sediment samples were collected with an Eckmann dredge. One sample was collected at each of the two in-lake stations and sent to the laboratory for analysis. The tests were chosen to characterize the sediment in terms of nutrient content, organic material, and heavy metal pollutants which would affect the potential i for dredging or removal of sediment from Lake Boon. i Several indices were used to put the results from Lake Boon into perspective. The Clarke Number (CN) is a standard index (McGinn, i 1981) used to evaluate concentrations of metals. This number represents the average concentration of an element in the earth's crust. Local variations within a factor of two or three can be i expected at specific sites. Sediments generally contain t concentrations less than the Clarke Number as they are composed of i i 2-46 i I I I CAMP DRESSER ''•*3-i- & McKEE INC. I in association with I IEP, INC. I H LAKE BOON Diagnostic Feasibility i Study TOWNS OF HUDSON AND STOW •i MASSACHUSETTS i i i NORTH i SCALE IN FEET 0 400 800 1200 NO MEASUREMENTS i >20 WATER DEPTH I FIGURE 2-12 i SEDIMENT i THICKNESS i I both mineral and organic matter. On the other hand, concentrations I in great excess of the Clarke Number can indicate pollution, EWPC (1978) has developed criteria for sediment chemistry to be used I in evaluating, and permitting proposed dredging projects. These criteria consider both physical (Class A, B and C) and metal pollutant (Class 1, 2, and 3) parameters. Finally, data from other IV lakes in Massachusetts surveyed by EWPC can be used to put these I results into perspective. Total volatile solids is a physical parameter which describes the I portion of sediment composed of organic material, primarily decaying plant remains. EWPC classifies sediment with >10% volatile solids as high in organic material. Generally, wetland soils have >10% organic I material, whereas upland soils have <10%. The Lake Boon samples i would therefore be considered to be high in organic matter (Table 6). Components of decaying organic material include phosphorus and I nitrogen which are primary plant nutrients. Total phosphate in the Lake Boon samples is low compared to an average of 1073 mg/kg for i sediment samples collected from Massachusetts lakes (EWPC, 1981a) whereas total nitrogen is above the average of 11,000 mg/kg. The nutrient content of this sediment becomes imporant when dissolved i oxygen levels in bottom waters are low creating favorable conditions for nutrient release. At Lake Boon, there is potential for this i process. i Oil and grease averaged 4840 mgAg or 0.48%. This is considered low by the EWPC classification «0.5% constitutes category A sediment) i and does not indicate any problems at Lake Boon with this parameter. The concentration of metals in the samples would place these i sediments in Class 3, requiring strict controls on dredging and disposal of these sediments. Analyses for chromium, iron, manganese, i and mercury all revealed low concentrations compared to DWPC i i 2-48 t I standards and the Clarke Number (Table 2-7). Copper, nickel, I vanadium, and zinc were detected at moderate levels. Elevated levels of arsenic, cadmium, and lead were noted. I Lead levels were comparable to those found by DWPC in Lake Boon in 1979 and, while elevated above the Clarke Number, are comparable to 1 levels detected in other lakes in the Commonwealth (Table 2-7). As this appears to be a regional phenomenon, it may reflect fallout of I lead from atmospheric pollution and runoff from street areas. Arsenic concentrations were seven times higher in 1986 then in 1979 I (DWPC, 1979). However, the only known potential source for this contamination is the chemical treatment of the lake in the 1960's I which likely included sodium arsenate. Cadmium levels were 12 to 275 times higher in 1986 then in 1979. No new source of this i contamination was identified in the watershed. Metal concentrations quoted in this discussion represent total metal i concentration in the sediment. These numbers do not reflect, and cannot be used to evaluate toxicity. A large portion of the metals i contained in sediments are bound to the sediment particles, or insoluble forms. Therefore an EP-toxicity test would yield lower s concentrations than a total metals test. i 2.3 HYDROLOGIC AMP NUTRIENT BUDGETS i 2.3.1 HYDROLOGIC BUDGET DWPC (1981) calculated an average annual hydrologic budget for Lake Boon based on local precipitation data, regional evaporation rates, i and stream gaging on the Assabet River at Waynard (Table 2-8). t Precipitation for the year is shown on Figure 2-13. i i i 2-49 t Table 2-7 Sediment Analyses, Lake Boon (concentrations in mg/kg, dry weight, except where noted) DWPC Clarke DWPC Station 1 Station 2 Classification Number Average Total Volatile Solids (%) 20.2 32.5 C Total Phosphate (mg/1) 309 492 1073 Total Kjeldahl-nitrogen (mg/1) 23,680 18,760 9792 Oil and Grease 4,200 5,480 A Arsenic ^66 74 3 Cadmium ^550 49 3 0.1 3.4 Copper 115 110 2 55 191 Chromium 54 33 1 100 42 Iron 45,000 16,000 56,000 35,388 Manganese 440 710 950 854 Lead 390 410 3 12.5 287 Nickel 48 66 2 Vanadium 130 <16 2 Mercury 0.14 0.20 1 Zinc 320 470 2 70 310 I 1 I Table 2-8 Lake Boon, Hydrologic Budget (DWPC, 1981) IVi A INPUTS million gallons/year million cubic meters/year Runoff (mostly ground water) 802 3.03 • Direct Precipitation 184 0.70 TOTAL 986 3.73 I OUTPUTS Outflow 873 3.30 f Evaporation (potential) 125 0.47 I TOTAL 998 3.77 I 6 I I I I I i i i * LEGEND X 8 -- 7 -- Normal 6 -- 5 4 3 2 1 0 Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep LAKE BOON FIGURE 2-13 DIAGNOSTIC FEASIBILITY STUDY PRECIPITATION TOWNS OF HUDSON AND STOW CAMP DRESSER & McKEE INC. fn association with IEP, INC. (INCHES) MASSACHUSETTS I Although seepage meters were used to assess groundwater flow into the I lake (CWPC, 1981), they did not provide sufficient data to allow an I estimate of the percent of runoff as groundwater flow, As groundwater monitoring was not part of the present study, we still do not have a good estimate of this number. However, the geology of I the watershed and field observations indicate that the vast majority I of runoff to Lake Boon is groundwater; stream flow is limited. The average annual outflow from the lake was found to be 3.7 cubic feet per second (cfs) (EWPC, 1981). Based on this flow, and the 1 volume of the lake, the retention time is 0.57 years and the flushing rate is 1.8 times per year. This means, if Lake Boon were empty, on I the average it would take 220 days to fill. This low flushing rate I reflects the large size of the lake in relation to its watershed. This flushing rate would be even lower if the White Pond area were not contributory to the Lake Boon watershed. About 190-195 million 1 gallons of water are pumped out of white Pond per year to augment Maynard's water" supply (Sheridan, personal communication.). Due to I pumping and meteorologic variations the water level of White Pond ranges from 183.5 feet to about 190 feet above sea level, whereas Lake I Boon's water surface is about 186 feet above sea level. Given this pumping rate, the similar elevations of the two water I bodies and the lack of an outlet on White Pond, it is doubtful that seepage from White Pond enters Lake Boon. In fact, it is likely that 1 groundwater flows toward White Pond along its entire perimeter. In this case, the Lake Boon watershed is 583 hectares (1440 acres). 1 Adjusting the hydrologic budget yields an average annual outflow of 3.2 cfs, and a flushing rate of 1.4 times per year. In any case, it is clear that the flushing rate for Lake Boon is very low and this I will be a critical factor in planning lake management. 1 I I 2-53 I I Precipitation data from the year of the EWPC study, long-term (30 I year) normals (NQAA, 1982) are shown in Figure 2-13. Review of these records shows that over the long term, precipitation is spaced evenly 1 through the year, but on any given year, precipitation may be very I unevenly distributed. Based on the meteorologic conditions of our I year of study, a hydrologic budget was calculated (Table 2-9). Total runoff from the watershed was calculated by comparing drainage I areas with the Nashoba Brook watershed in Acton, for which discharge data were available. The Nashoba Brook watershed was chosen because. It is most like the Lake Boon watershed in terms of geology, size, and 1 land-use of the areas gauged by U.S.G.S. (Wandle and Fontaine, 1984). Groundwater inputs to Lake Boon were calculated based on the geology I of the watershed (Figure 2-4), and assuming a recharge rate of 6 inches per year for till areas, and 15 inches per year for sand and I gravel areas. It was also assumed that all groundwater discharge from the watershed entered the lake; in other words, no groundwater passes beneath the lake. In actuality, some unknown amount of groundwater 1 probably does not enter the lake, and this estimate should be I considered to be on the high side. In order to present the groundwater budget on a monthly basis it was assumed that groundwater inputs were evenly spaced through the year. I This is probably a fair assumption as groundwater flows are somewhat buffered from short-term meteorologic fluctuations. The final I hydrologic input, direct precipitation, was calculated by multiplying I the lake area by the depth of precipitation each month. Hydrologic outputs from the lake include flow through the outlet I structure, evaporation and seepage. Seepage was assumed to occur only in the vicinity of the outlet, and based on that limited area would be orders of magnitude less than the other budget components. Evaporation i rates were estimated using mean monthly temperature data available for Bedford (NQAA, 1985, 1986), and the Thornthwaite method (Dunne and i Leopold, 1978). Even though this method is meant to estimate I i 2-54 i Table 2-9 Lake Boon, Year of Study Hydrologic Budget (millions of gallons) Surface Ground- Direct Total I Runoff water Precipitation Evaporation Outflow Out 1985 October 3.4 37.7 53.0 7.9 45.1 53.0 i November 82. 3 37.7 151.4 4.1 137.3 141.4 December 31.4 37.7 75.5 0.0 75.5 75.5 1986 i January 59,3 37.7 114.7 0.0 114.7 114.7 February 37.2 37.7 89.5 0.0 89.5 89.5 March 118.0 37.7 171.3 2.3 169.0 171.3 April 15.5 37.7 67.3 7.1 60.2 67.3 t 26.2 38.3 May 0.0 37.7 38.3 12.1 June 0.0 37.7 104.8 14.8 90.0 104 .*8 July 0.0 37.7 65.5 18.4 47.1 65.5 I August 0.0 37.7 40.9 16.8 24.1 40.9 September 0.0 37.7 13.2 13.2 0.0 13.2 888.7 985.4 i TOTAL 347.1 452.4 185.9 985.4 96.7 I t i i i I I i i I evapotranspiration on land areas, that it yields total evaporation I rates similar to published regional averages for lakes. Evaporation in central Massachusetts lakes averages 27 inches per year (Dunne and I Leopold, 1978). Outflow was calculated as the difference between total inflow and I evaporation, assuming that there were no changes in the water level in Lake Boon during the year of study. Outflow was also measured during I the water quality sampling rounds. Measured outflows were 2,25 cfs in October, 3.10 cfs for April, and 2.35 cfs for July. Whereas these values are in poor agreement with the estimated values, instantaneous I stream flow can be expected to vary greatly from the monthly mean. I Whereas 90% of the hydrologic outputs were outflow from the culvert at Barton Street, inflows were more evenly distributed between I groundwater (46%), surface runoff (35%), and direct precipitation (19%). Comparison of the total inflow with the lake volume yielded a flushing rate of 1.8 times per year, or a retention time of 0.57 years I (207 days). This flushing rate is somewhat higher than the rate calculated for the time period during the EWPC (1981) study. This may I in part explain the lower nutrient concentrations in-lake in 1985-1986 compared to 1979-1980. Also, there was little snow accumulation and low spring time precipitation during the present study, limiting the I high spring runoff period. I 2.3.2 NUTRIENT BUDGET I An average annual nutrient budget for Lake Boon was calculated using loading coefficients and the land use of Lake Boon's watershed. This method assumes that the phosphorus export to the lake can be predicted I by the type of land use in the watershed (EPA, 1980a). Based on land use in the Lake Boon watershed, 219 kg/^r of phosphorus are introduced I to the lake (Table 2-10). Due to year to year variability because of I meteorologic conditions and error in this type of method, a low and I I 2-56 I I I Table 2-lfJLake Boon, Nutrient Budget I A) Non-Point Source Loading I -Phosphorus Loading (kg/yr)- Land Use Lov Most Likely High X Vatershed X Loading 1 Residential 42 51 71 18 23 Industrial 21 53 60 3 24 1 Forest/Wetlands 37 73 110 65 34 Open Land 3 9 16 1 4 * Atmospheric 20 33 79 13 15 t 1 TOTAL 123 219 336 100* 100% B) Septic System Loading il^B No inputs 0 kg/yr t 1 Most likely** 375 kg/yr Vorst case 1500 kg/yr 1 C) Internal Release 6.5 kg/yr I ^accounts for direct precipitation onto vaterbodies I assumes 15% attenuation of phosphorus by soils I I I I I high estimate of the nutrient loading is shown along with the most I likely value. I The above estimates account for non-point source loading to the lake, i.e. diffuse runoff through groundwater and stream flow. Potential point sources of phosphorus to Lake Boon include all of the septic I systems within 10Q m from, the lake. Under tidal conditions, soils attentuate all of the phosphorus in septic effluent before it reaches I the lake. However, with systems less than 100 m from the lake, poor soil conditions, and aging systems, it is likely that some nutrients I do find their way to the lake. This was demonstrated through the septic survey and seepage meter data collected by EWPC (1981). I As a worst case, with no soil attenuation, 1.6 kg per year per person are exported from near-shore septic systems to the lake (EPA, 1980b). I Using this number, along with the results of the resident's questionnaire distributed during the present study, it is estimated I that a worst case loading from septic systems would be about 1,500 kg/yr (Table 2-10). A "most likely" estimate, assuming 75% efficiency of septic systems, yields 375 kg/yr delivered to the lake. This 75% I efficiency is based on knowledge of the soils and septic system I history in the Lake Boon area. Internal recycling of phosphorus may also make this nutrient available I for plant and algal growth. Release of phosphorus occurs under anoxic (no oxygen) conditions from decomposition of lake sediment. During summer stratification, near anoxic conditions occurred in the deeper I water of Lake Boon (Table A19), and slightly elevated concentrations of phosphorus were noted (Table All). About 6.5 kg of phosphorus were I released, calculated by multiplying the volume of the hypolimnion (bottom layer of the lake) by the difference in concentration of phosphorus in the hypolimnion versus the epilimnion (top layer of the I lake). This source of phosphorus to Lake Boon appears to be minor at the present time compared to non-point source and septic inputs (Table I 2-10). I I 2-58 I I Another method of estimating the phosphorus loading is with one of the I input-output models which have been developed. These estimate phosphorus loading based on inputs from the watershed and outputs of I sedimentation and outflow. The model developed by Vollenweider (1975) is: I L = TP (Z) (S + F) I L = phosphorus loading in mg/m /yr TP = total phosphorus in-lake in the spring in ug/1 Z = mean depth in meters I S = effluent phosphorus concentration/influent phosphorus concentration I F - flushing rate per year I This model was calibrated for Lake Boon for the spring of 1979 (EWPC 1981), I960 (CWPC 1981), and 1986 (present study) and yielded loading rates of 635, 159, and 60 kg/yr, respectively. Both the 1980 and 1986 I loading estimates based on in-lake phosphorus concentration are low compared to the estimate based on land use. However, the analyses for I the 1979 data indicate phosphorus loading levels (635 kg/yr) which are consistent with the most likely phosphorus loading estimated in Table I 2-10 (600 kg/yr). Assuming that non-point source loading based on land use is consistent from year to year suggests that substantial I septic system contributions occurred in 1979, but not in 1980 or 1986. A closer look at the meteorologic records from these three years I yielded an explanation for the wide variation in in-lake phosphorus levels. The spring is the most critical time of the year for I phosphorus loading to New England lakes. Runoff is generally highest because of snowmelt, high groundwater levels, and low evapotranspiration. Phosphorus loading is likewise concentrated in I the spring. During the four month period of January to April, total precipitation in the Lake Boon area was 23.4 inches in 1979, 12.4 I inches in 1980, and 12.2 inches in 1986, compared to a normal of 15.9 I I 2-59 I I inches. The two springs with lower than normal precipitation were the I years that phosphorus concentrations did not indicate input from septic systems. In contrast, in 1979 springtime precipitation was I about 50% greater than normal and phosphorus levels in-lake suggest a substantial contribution from shoreline septic systems. A high water table and high water level in-lake enhance leaching of nutrients from I shoreline disposal areas during these conditions. I 2.3.3 TROPHIC STATUS Basic measurements of biological, chemical and physical parameters I describe the environment that influences the trophic condition of Lake Boon. Lakes are classified into categories or trophic states by I depth, concentrations of dissolved oxygen and nutrients, transparency (water clarity), and biological productivity. Oligotrophic lakes have I high transparency, low nutrient concentrations, little sediment accumulation, and are well aerated throughout the water column. Mesotrophic lakes have reduced transparency, moderate nutrient I concentrations and biological productivity, increasing sediment accumulation, and some oxygen depletion in deep waters especially in I late summer and under ice cover. Eutrophic lakes have poor tranparency, excessive nutrients, rapid sediment accumulation and I increased biological productivity. The trophic state of Lake Boon was modeled using a method developed by I Dillon and Rigler (1975) which estimates trophic state based on mean depth, phosphorus loading and retention time. This model was I calibrated for Lake Boon under four scenarios including: I 1) the lake as it would have been under "pristine" conditions with a 100% forested watershed; • 2) the lake with present watershed land use and assuming no inputs I frofrramn septicpiiV^rc* systemse\7c^-*»me;» I I 2-61 I I 3) the lake with present watershed land use and most likely septic I loading; I 4) the lake with present land use and maximum possible septic loading. I Review of this model shows that at present Lake Boon falls in the borderline mesotrophic to eutrophic range (Figure 2-14). This is in I good agreement with observation made during the year of study including: I 1) oxygen depletion in the deepest basin in the summer; I 2) moderately high algal counts, especially blue-green algae; I 3) extensive aquatic plant growth in the shallow basins. Variations in septic loading will result in a range from highly I eutrophic to mesotrophic conditions at Lake Boon. The best estimate of present septic loading puts the lake in the mesotrophic range. I However -with aging of septic systems and saturation of shoreline soils with phosphorus the loading will over time approach the maximum I possible, placing Lake Boon in the highly eutrophic range. I I I I I I I 2-62 I I I I I I I I I I I I PRISTINE WATERSHED I I I0.01 10.0 1CG.C I MEAN DEPTH (m) L=AREAL PHOSPHORUS LOADING (g/m2/yr) R= PHOSPHORUS RETENTION COEFFICIENT (DIMENSIONLESS I T= HYDRAULIC RETENTION TIME (yr) I LAKE BOON FIGURE 2-14 DIAGNOSTIC FEASIBILITY STUDY CAMP DRESSER &McKEE INC. in association with DILLON/RIGLER TOWNS OF HUDSON AND STOW I IEP, INC. TROPHIC STATUS MASSACHUSETTS I I I 3.0 FEASIBILITY STUDY I 3.1 INTRODUCTION The primary problem in Lake Boon appears to be aquatic weed growth which interferes with recreation in the lake. The weed growth is heaviest in the I upper basin of the lake where depths are shallowest. The shallow depth, along with high nutrient levels in the sediments, seems to be the primary I cause of the weed growth. Removal of nutrients from the water column may, over time, reduce the aquatic weed problem. However, it is likely that significant aquatic weed problems will continue unless physical measures I are also taken. Secondary problems in Lake Boon include occasional oxygen depletion in the deepest basin of the lake, and occasionally moderate blue I green algae counts. I The renovation of Lake Boon is complicated by chemical constituents in the sediments of the lake and by the many shoreline drinking water wells. Specifically, although dredging would appear to be the logical choice of I alternatives for the renovation of the lake (by making it deeper), contaminants in the sediments may make dredging difficult. In addition, I some other types of lake treatment that might normally be used are not recommended for Lake Boon because of the shallow drinking water wells that I surround the lake, many very close to the lakeshore. These wells probably draw water nearly directly from the lake in some cases, and may be I indirectly affected by work on the lake. I 3.2 TECHNOLOGY IDENTIFICATION AND SCREEMING The full list of possible technologies considered for Lake Boon is I shown on Table 3-1. These technologies were evaluated using the following criteria for the first screening: I Effectiveness - capability to produce desired results I Recreational - ability to produce desired recreational improvements I I 3-1 I I I TABLE 3-1 I TECHNOLOGY SCREENING ALTERNATIVE SCREENING FACTORS COMMENTS I E R I Dredging Cost may prohibit, be hard I to implement because of contaminated sediments Aeration/Mixing Not effective, eliminate Hypolimnetic Withdrawal Not effective, eliminate I Sediment Blanket Retain Dilution Retain Drawdown Probably not implementable on I large scale due to effects on wells Weed Harvesting •*•+ Retain Chemical Treatment Probably not implementable I due to effects on wells Phos. Precipitation Probably not implementable _ due to effects on wells I Biological Treatment 0 0 Not effective, eliminate Diversions 0 0 0 Probably not effective, wait for nutrient budget eval. I Treatment of Inflows 0 0 0 Probably not effective, wait for nutrient budget eval. Sewering + •f + Cost may prohibit Septic System I Modifications Effectiveness minimal to moderate Septic System I By-Law/Zoning Meas. Effectiveness minimal to moderate Erosion Control Retain I Community Septic Sys. Effective location may be difficult I Wetlands Treatment Probably not effective E = Expected Effectiveness R = Recreational Improvement or Benefit I I « Implementability I I I I I Implementability - ability to be implemented under current regulations I and considering physical features of the lake I The matrix analyses, shown on Table 3-1, rates each technology based on (++) highly beneficial or excellent; ( + ) beneficial or good; (0) ineffective or neutral; (-) adverse or poor. Based on this, several I technologies were eliminated or modified as described below. I 3.2.1 REASONS FOR REJECTION OF ALTERNATIVE TECHNOLOGIES I The following technologies were eliminated from further consideration based on preliminary information. The reasons for rejection of each technology is also given. A discussion of technologies that I have been retained follows in section 3.2.2 "ALTERNATIVES FOR FURTHER I CONSIDERATION." I Aeration, Mixing, and Hypolimnetic withdrawal The purpose of aeration and mixing is usually to eliminate stratification from a lake, and thus prevent anaerobic conditions at the bottom and the I release of phosphorus from the sediments. Similarly, hypolimnetic withdrawal removes the poorer quality water from the bottom of the lake I first, discharging it downstream. In Lake Boon, near anoxic conditions occurred in deeper waters during summer stratification, and slightly elevated concentrations of phosphorus were noted. However, this condition I is estimated to contribute only about 6.5 kg phosphorus per year, which is a very minor part of the total phosphorus loading. For these reasons, it I is not expected that aeration or mixing would be effective at improving water quality in the lake or reducing phosphorus levels. These I technologies have therefore been eliminated. I Diversions The diversion of one or more inlet or stormdrain around a lake is I sometimes used if the flushing rate of the lake is too high, or if there I I 3-3 I I is one particularly high phosphorus inflow. In Lake Boon, the eastern I inlet, 13, tended to have the highest concentrations of nutrients and could be considered for diversion. However, the overall volume of water I contributed by this tributary is relatively minor. Further, the flushing rate of the lake is very low at present, and diversion of some of the flow would result in an even lower flushing rate for the lake. There are also I the obvious problems with diversion — great expense, and displacement of I problems downstream. I Treatment of Inflows The treatment of inflowing streams could be done by one of several methods — most commonly sedimentation basins or ponds. Actual water I treatment, or filtration using drinking water treatment processes, could also be used but is often prohibitively expensive. In general, the I inflowing streams to Lake Boon are primarily groundwater-based streams and none have substantial enough flow to warrant treatment. I Drawdown I "Drawdown programs are sometimes established in lakes to attempt to control aquatic vegetation. The theory is that overwinter drawdown will freeze I and kill the aquatic plants along the shoreline, reducing the problem for the next summer. Although drawdown might be effective in Lake Boon, it is also likely to affect local drinking water wells all around the I shoreline of the lake. Many of these are shallow dug wells within a few feet of Lake Boon, and, large water level fluctuations in Lake Boon would be I likely to affect the performance of these wells. Because of this, drawdown has been eliminated from consideration except as a minimal winter program I of 1-2' drawdown for shoreline cleanup. I Chemical Treatment Chemical treatment is sometimes used both for control of aquatic weeds and I algae. Although somewhat effective in the short-term, chemical treatment I I 3-4 I I does not alter the source of the problem. • It can also cause increased I nutrient problems by the release of nutrients from dead vegetation. Most importantly, however, the use of chemical treatment in Lake Boon is not recommended because of the shoreline drinking water wells. Chemical I treatment, including alum treatment to precipitate phosphorus, is I eliminated for this reason. I Biological Treatment There are a number of biological controls that have been used elsewhere, including techniques such as the introduction of weed-eating fish, I biomanipulation, and the use of aquatic plant pathogens. However, most of these methods are relatively experimental and probably not applicable to I Lake Boon. I For instance, grass carp have been used to control several types of vegetation, but they have not been successful with milfoil which is known to be present in Lake Boon. Assuming that the grass carp would eat I Camboba, the milfoil might potentially become an equally serious nuisance. Further, there is no way to contain the fish within the lake, and their I migration to other waterways is not desirable. I Biomanipulation includes "lake improvement procedures that alter the food web to favor grazing on algae by zooplankton, or that eliminate fish species that recycle nutrients." (Cooke, et al, 1986.) This might be I done by the removal of undesirable fish species and replacement with more desirable species. However, biomanipulation is geared more towards I control of algae than aquatic weeds, so it is probably not appropriate for Lake Boon. Similarly, aquatic plant pathogens and insect predators have I been developed for certain species of aquatic plants. However, no work has been done on the species that are a problem in Lake Boon. Biological controls will not be considered further in the evaluation for these I reasons. 1 I I 3-5 I I I Wetlands Treatment As with diversion and inflow treatment, wetlands treatment may not be I effective because none of the inflowing tributaries contribute a high enough proportion of the flow or pollutants to warrant specific treatment. I This technology has been eliminated from further consideration. I Community Septic Systems Another way to deal with septic systems around Lake Boon would be to I construct a community system, collecting wastewater from homes along the shoreline with transfer to a large central septic system for treatment. However, the most significant drawback to this alternative is that there is I no potential location for such a facility in the Lake Boon area. I 3.2.2 ALTERNATIVES FOR FURTHER CONSIDERATION I As shown on Table 3-2, the technologies that were not eliminated during the first screening were evaluated a second time, in this evaluation, several I new factors were considered, including: Complexity - difficulty of operation and maintenance I Flexibility - ability to adapt to changing conditions Experience - past success/failure of component options I Environmental - impacts on terrestrial and aquatic life I In-Lake Restoration Technologies The primary problem that in-lake technologies must address is aquatic I weeds. Algal problems have not been serious to date, although nutrient levels are moderate and the flushing rate of the lake is low indicating a I good potential for future algae problems. Dredging. Although dredging would be a relatively effective technology for I Lake Boon, the size of the lake makes complete dredging impractical and I I 3-6 I I I TABLE 3-2 I SECOND ALTERNATIVE SCREENING ALTERNATIVE EV COMMENTS I Dredging Cost prohibitive Sediment Blanket ++ Could be excellent on I limited scale Dilution Very complex, effects on wells difficult to I predict/unplugging specific culverts I retained Weed Harvesting Purchase of harvester cost-effective, but I operator would have to be designated Seweri ng Very high cost, I justification difficult Septic Modifications ++ Success dependent on I local factors Septic System ByLaw/Zoning Measures ++ Success dependent on I enforcement Erosion Control ++ Success dependent on I enforcement I Minimal Drawdown Program Only with very minimal I (1-2') drawdown I C = Complexity - difficulty of operation and maintenance F = Flexibility - ability to adapt to changing conditions EX = Experience - past success/failure of component options I EV * Environmental - impacts on the environment I I I I difficult to implement. In addition, dredging can cause sediment I resuspension and the release of materials adsorbed to the sediments. As a result, dredging may be very difficult to implement at Lake Boon because of the relatively high concentrations of some metals in the sediments. The I levels of contaminants in the sediments may make permitting difficult or impossible, and a location for dredge spoils disposal must be found. I However, the dredging alternative will be retained to use as a "benchmark" I for comparison purposes. Sediment Cover. As a method to control aquatic weeds, the use of a sediment blanket, or weed barrier, should be considered. The purpose of I the sediment cover is to either physically prevent weed growth from the bottom, or to block light penetration to the sediments to prevent weed I growth. One commercial type of material is Aquascreen, although several types of filter fabric material have been used for the same application f previously. High density 30 mil polyethylene or similar sheets of synthetic material would be placed in shallow areas and anchored with concrete blocks or weights. If solid sheets were used, small holes or I ports would have to be provided to vent gases found in the decomposing matter in the sediments. This method has an effect similar to dredging, I especially in the shallow water areas. I The advantages are that the sediments are not disturbed, so that the contaminants found in the Lake Boon sediments would not be released into the water column. This technology would also be quite flexible, since I the screens could be moved as necessary. Disadvantages are its relatively high expense to treat large areas, and the need for removing or cleaning I the screens each year (high complexity). Also, there is relatively little I experience with this method. Dilution. In Lake Boon, dilution could be used to improve water quality by adding large volumes of clean, nutrient-free water. The only available I source of clean water is likely to be groundwater pumped from somewhere nearby the lake. This would be likely to improve the trophic status of the I lake because it would increase the flushing rate. Presently, the lake has I I 3-8 I I a relatively slow flushing rate, which is the time it takes the water in I the lake to completely flow through. I Unfortunately, pumping groundwater in large volumes is very expensive and the aquatic weeds in Lake Boon can probably obtain adequate nutrients from the sediments, so dilution may not significantly affect the primary I problem in the lake. The effects of large-scale pumping of groundwater on local drinking water wells and groundwater patterns is also not known, and I would require extensive investigation prior to implementation. I However, one method specific to Lake Boon that would provide the same type of benefit would be cleaning or reopening the culvert on Sudbury Road and one just north of that. These two culverts are plugged and surface flow I does not go through them—instead the water ponds and probably goes through I as groundwater flow. Weed Harvesting. Weed harvesting can be done by one of several methods, I but the general idea is to cut and remove aquatic plants from the lake. It has the advantage of good flexibility, in that the area(s) of harvesting can be easily modified, and the harvesting can be done on an as-needed I basis. Another advantage is that there is a lot of experience with this method, and it is reliable and well-tested. The environmental impacts are I also very minimal, especially when compared with other weed control methods such as dredging. On the negative side, weed harvesting has a relatively I high operations and maintenance cost, or annual cost, although this can be minimized over the long-term by the purchase of a harvester. Additionally, I weed harvesting is usually required every year, sometimes twice per year. Hydroraking is another method of physically removing nuisance aquatic I vegetation. Unlike a weed harvester which simply cuts the plants with sickle bar type cutters, a Hydro-Rake actually rakes the lake bottom to I remove not only the stems and foliage but also the roots. The Hydro-Rake resembles a floating back-hoe with an 8 foot wide York Rake attached to the hoe arm rather than a convential back-hoe bucket. The Hydro-Rake can I remove weeds and much in water depth up to 12 feet deep versus a depth I I 3-9 I I limitation of 5 or 6 feet for a harvester. The Hydro-Rake has no on-board I storage therefore each rake-full must either be deposited directly on shore or onto a waiting transport barge. Several years of control have been obtained on vegetation with large tubers such as spatterdock and white I lilies. The Hydro-Rake is somewhat less effective on weeds such as water I milfoil and pondweed which have small hairlike roots. Although more effective than weed harvesting, Hydro-Raking is also more I expensive, costing between $1,500 and $3,000 per acre depending upon weed and bottom type as well as the disposal system. I Watershed Restoration Technologies I The major problem in Lake Boon is aquatic weeds. Algal problems are secondary and have not been serious. The moderate nutrient levels in the I lake are probably the primary cause for algal problems, and the removal of nutrients from the lake could be expected to reduce existing or future problems. However, it is not expected that a reduction in nutrient I levels in the water column by itself would significantly affect aquatic I weed problems. Watershed management strategies that reduce nutrients in Lake Boon should I therefore not be the only alternatives, but should be combined with in-lake strategies to deal with aquatic weeds more directly. Several I watershed restoration strategies are discussed below. Sewering. As mentioned previously, one of the suspected causes of nutrient I loading to the lake is septic systems located on poor soils around the shoreline. To address this problem, one method would be to sewer the area I and transport domestic sewage to a wastewater treatment plant. The major advantage of sewering is that septic systems and cesspools can be abandoned and this source of potential pollution is completely removed. I However, the placement of sewer lines is very expensive, and in addition, the sewage must be pumped to a wastewater treatment plant of some type with I the discharge of treated effluent elsewhere. I I 3-10 I I The Town of Hudson is partially sewered, but no plans to sewer the Lake I Boon area have been made, stow has no sewers at present. Assuming that all shoreline residences were connected to sewers, then the sewage would I still have to be treated somewhere regionally or in a package plant locally. The largest question with this method is the cost- effectiveness I of such a large expenditure compared with the benefits of removing a relatively small amount of nutrients from Lake Boon. 1 Septic System Modifications. An alternative to sewering would be to modify or replace existing septic systems and cesspools. Many of the systems I around Lake Boon were installed when the homes were summer homes, and may be undersized for year-round residences. This is currently controlled to I some extent through existing by-laws and ordinances, in that modifications or expansions of existing buildings require building permits and are supposed to meet certain septic system requirements. However, this does I nothing to address most of the systems surrounding the lake. I In most cases, replacement and cleaning of septic systems is the responsibility of the individual owners. Failing systems are first I identified, and then the Board of Health or other responsible agency orders the owner to take corrective measures, whether this means pumping I out the system, repairs, or complete replacement. Unfortunately, it is very difficult to identify undersized or failing I systems unless they are actually leaching out onto the ground. When this happens, neighbors may report odor problems, and the failed system is I identified this way. If breakout above ground has not occurred, failure or undersizing of the system will go undetected. In the Lake Boon area, this is particularly likely to happen since the soils have high I percolation rates, and breakouts are more likely to be seen where the soil has low permeability (high clay content) or hardpan layers. In other I words, nutrients from the septic systems surrounding the lake may be leaching into the groundwater and then entering the lake, but if so it is I probably because of the high percolation rates rather than actual failure I of the systems. I 3-11 I I One way to attempt to deal with potentially polluting systems would be to I establish a program for pumping the systems regularly. I Septic System Bylaw/Zoning Measures. Some measures are already in place to control septic systems in the watershed, but these pertain only to new systems for the most part. It is much more difficult to control existing I systems, however, one method to do so would be through Board of Health powers or new bylaws. First, however, specific systems must be identified, I and to do this, drinking water well sampling may be the most effective method. It would have the additional benefit of identifying any public I health problems from nitrates, and would define general phosphorus concentrations in groundwater flowing in the vicinity of the lake. I Erosion Control. Erosion in the Lake Boon watershed is not expected to be a significant problem for the most part because so little of the lake's I inflow comes from surface flow. However, certain problem areas have been noticed by area residents, and could be corrected relatively easily by I specific methods at each erosion site. I 3.3 FINAL OPTIONS I The following options have been derived from the technologies discussed above using various combinations of alternatives. Each of the options I attempts to deal with the most obvious problem, aquatic weeds, and to reduce nutrients in the lake's water column thus reducing potential algae I problems. I 3.3.1 OPTION 1 - SEWERING AND DREDGING I Description This option includes two main components: a) the sewering of I the Lake Boon shoreline, with transfer to the Hudson wastewater I I 3-12 I 1 I treatment plant about four miles away; and b) hydraulic dredging of Lake Boon with onsite dewatering and disposal. I Sewering of the Lake Boon shoreline would include the placement of lateral sewers along all streets within 300 meters of the shore of I the lake. Transfer to a trunkline would be by gravity to collection points where lift stations would be required. The main I trunk line would then transfer wastewater to the Hudson wastewater treatment plant slightly less than four miles away. Another pump I station would probably also be required. Full dredging of Lake Boon would involve hydraulic dredging since I the lake can only be drawn down to a limited extent due to near-shoreline drinking water wells. To dredge the lake to a I minimum ten foot depth throughout, Basin 3 would require almost complete dredging — or about 35 acres and 209,000 cubic yards (160,000 cubic meters). A 1:4 foot slope would be left at the I edges of the lake, and the liquid material would be pumped to a I location along the shoreline where dewatering would take place. 'Since the Town(s) do not own any areas that could be used, the land would have to be taken by eminent domain. About 25 acres I should be sufficient to locate a dewatering facility, storage area, and staging area — final disposal could also be on the I site,, with a minimum of about 14 acres (of the 25 acres) of land I required for disposal of materials from Basin 3. Basin 2 would require dredging of about 17 acres, or 74,000 cubic yards (57,000 cubic meters) to bring it to a minimum ten foot depth. Basin 1 I would require only minimal dredging of the perimeter, about 5 acres I maximum, or 15,000 cubic yards (11,000 cubic meters). The dewatering of the spoil from these two areas will probably require a I separate area from that used for Basin 3, due to the distance from dredging I areas. Assuming that one central dewatering area could be used for Basin 1 t 3-13. I I and 2, about 15 acres would have to be taken for the dewatering operation and staging, although the final disposal could probably be accomplished at I the 25 acre site used for dewatering/staging and disposal of materials from Basin 3. Dried materials would have to be trucked to the site from I the dewatering area, and it is assumed that the dredging and dewatering of Basin 3 would occur first so that the site would be available for disposal I of dry spoil from Basin 1 and 2 when those basins were dredged. I Cost Estimate Capital Cost. The sewering portion of Option 1 has a capital cost I estimated at $ 5,500,000, which represents construction of about 52,000 feet (10 miles) of laterals and a trunk line of about 16,000 feet (3 I miles). Individual tie-ins of homes are not included, since these would be at the owner's expense (about $2,000 per house). Land takings for the sewer line are also not included since these are unknown. The cost does I include construction of two pumping stations. I For the dredging portion of the option, the capital cost for dredging, dewatering, storage, and onsite disposal is estimated at about 4.5 million I dollars. The required land takings would cost an additional $500,000. The total capital cost of Option 1 is almost $11 million. Unfortunately, little or no funding is readily available for sewering projects at present, I and neither of the Towns involved has any plans for sewering the Lake Book I area. Operations and Maintenance Costs. While the dredging portion of the I alternative does not have any significant operations and maintenance costs, the disposal site would require closure and probably reseeding/replanting. Some form of leachate control would have to be left in place, although it I is unlikely that capping or leachate collection/treatment would be required. The sewering portion of the alternative would have an annual I cost of approximately $600,000 for treatment of the wastewater at the Huson WWPT, and the operation and maintenance of the pump stations. This I cost would not be eligible for funding. I I 3-14 I I Unit Costs. Option 1 as estimated above assumes full dredging and full I sewering of the area, since this would reduce unit costs substantially over dredging only a small portion of the lake or sewering only part of the i shoreline. Dredging unit costs are approximately $79,000 per average acre, including dewatering, disposal, etc. Downsizing of the sewering project to I include fewer houses could not be recommended because the most expensive components of the project would still be required, namely the trunkline and I pump stations. As a result, no unit costs can be given for sewering. 3.3.2 OPTION 2 - WEED SCREENS, PUBLIC EDUCATION, AND SEPTIC SYSTEM I MEASURES I Description This alternative includes two main components: a) the use of weed I screens or other bottom coverings in areas of dense aquatic macrophytes; and b) the implementation of septic system measures i to control and reduce septic system leachate entering Lake Boon. t The first portion of this option involves the use of weed screens to physically prevent weed growth or to block sunlight from the bottom of the lake in areas of normally dense macrophyte growth. i One commercial type of material is Aquascreen, although several types of filter fabric material have been used for the same i application previously. i The material, whether in rolls or blocks, is sunk to the bottom of the area for control, and then pinned or weighted down with blocks or weights. Divers may be used to secure the material in deeper i areas, and it may be rolled out from shore and weighted at intervals along its length. The material is put in place in i spring before macrophyte development is significant, and removed i and cleaned in the fall after use. i i 3-15 i I In Option 1, it was estimated that a total of 57 acres of Lake I Boon is less than 10 feet deep, and this same number could be used to estimate the acreage to be covered by weed screens. However, I because this option is repeated each year rather than being a one-time event, fewer acres could be covered with similar effects. In other words, it does not appear necessary to treat I areas with minimal macrophyte growth since these materials could be moved from year to year if desired. To cover the more dense I areas, about 45 acres would be involved. The second portion of this option involves the implementation of I septic system measures to reduce/control leachate impacts on the lake. Basically, there are two major problems associated with I septic systems in the Lake Boon area: a) many systems are old and undersized, with many cesspools; and b) even with new, approved I systems, the soils have a high percolation rate and little filtering capacity, so many pollutants probably pass through to the lake. As a result, an inspection program to identify failures I would produce little evidence. However, there are other ways to deal with the problem, including 1) frequent pumping of systems to I improve their efficiency; 2) requiring the upgrade of cesspools upon resale of housing; 3) developing a method of identifying and I controlling failing systems through private well sampling and subsequent Board of Health action; and 4) the implementation of a 1 public education program. These steps are described below. Step 1 - Institute a Septic System Pumping Program. From the I questionnaire, it was estimated that fewer than 47% of the homeowners around the lake pump their septic systems I regularly, it was also estimated that as many as 27% of homes may have cesspools. Based on this, it would appear that an annual pumping program would increase the frequency of maintenance of I existing septic systems, thereby increasing their efficiency significantly. It would also identify the locations of 1 cesspools. While many of the cesspools may be "grandfathered". I I 3-16 t I some may be illegal and a pumping program would identify these for I further action. f There are several methods to implement a pumping program, however, the most cost-effective appears to be the use of a user fee for homes within a given radius around the lake or within the entire I watershed if desired. The pumping service would be similar to a garbage collection service, where the Towns bid out for the I services of one or more pumping service vendors to go through the list of homes on an annual basis and pump each one. I At the end of the work, the vendor(s) would submit a ticket or other record for each home pumped recorded with the address, date, I depth of sludge, quantity of septage pumped, condition of the system, and the location of the system access cover. Systems that I could not be pumped for some reason would also be reported. Annual bills would then be sent out to each of the homes, while the addresses of those homes that could not be pumped or had other I serious problems would be sent to the Board of Health or other I designated agent for action. Under Title 5, the Town of residence is responsible for providing I a disposal site for septage. Assuming about 350 gallons per year per septic system and 500 homes, this would be approximately 175,000 gallons per year. A long-term agreement with a nearby I wastewater treatment plant such as the Hudson plant would be advantageous to both Towns and would be the preferred method of I disposal. I Because the entire area for pumping would be bid as a unit, or at the most, one unit per town, the cost savings to homeowners over hiring individual vendors should be significant. However, the i political and legal ramifications of a mandatory program should be i examined by the Town's counsel prior to implementation. i i 3-17 i I Step 2 - Require Cesspool/Septic System Upgrade Upon Resale. From the I pumping program, a large part of the failing, inefficient systems will be dealt with — resulting in a significant reduction I in phosphorus loadings to the lake. One problem that will remain, however, are the "grandfathered" cesspools. Since the questionnaire survey resulted in an estimate of 27% or more of the homes (about I 145) with cesspools, this could be a significant amount. I To deal with these, an amended by-law requiring the upgrade of cesspools upon resale could be adopted. In this way, cesspools I would gradually be converted into more efficient systems. One problem that should be noted is that many of these old systems are associated with very small lots that cannot meet Title 5 requirements. i In these cases, a variance from Title 5 should be requested, rather than t leaving the system as is. Step 3 - Institute a Private Well Sampling Program. In order i to monitor the effectiveness of the above programs in accordance with the Clean Lakes Program, a multi-year monitoring program must be set up. To monitor the effectiveness of the above i steps, and to implement a method by which residents can determine the status of their wells, a voluntary private well monitoring i program should be developed as a part of the overall program. i Interested residents would be required to sign up for the program for the full term (3-5 years) at some designated location such as the Town Halls. Specific wells would then be selected from the i homes volunteering, with special consideration going to homes with well records (depth, screening, etc.). The 25-50 wells would then i be sampled on a quarterly basis for nitrogen parameters and phosphorus. Any wells with higher than background concentrations would then be reported immediately to the Boards of Health for i further sampling from a public health perspective. i i i 3-18 i 1 Step 4 - Implement a Public Education Program. As the final step I in the implementation of this component, a public education program should be developed to attempt to reduce the phosphorus I loadings to septic systems and to reduce the phosphorus loading I from overland runoff. This could include pamphlets or flyers discussing methods to reduce phosphorus use with detergents and fertilizers, as well as I lists of available phosphorus-free products. As part of the educational program, the Towns could provide individual homeowners I with information relative to cesspool and septic system operation. I Cost Estimate Capital Costs. The purchase of weed screens for 45 acres of the I lake represents the greatest capital cost of this option, at about $450,000. Other capital costs associated with this option include I approximately $30,000 to: a) write amendments to the by-laws incorporating the pumping program and the requirements for I upgrading systems upon resale; b) develop a well-monitoring program; and c) development, printing, and distribution of public educational materials. An additional $125,000 would be required I for the 5 year well monitoring program. With 75% funding under the Clean Lakes Program, the capital cost would be $151,250 to the I Towns of Hudson and Stow. Operations and Maintenance. Annual costs associated with this t option are also mostly associated with weed screen portion of the option, since these must be removed and cleaned each fall and I replaced each spring. This operation and maintenance cost is estimated to be $25,000 per year. Some administrative costs will also be borne by the I Towns for the billing/collections, etc. associated with the pumping program, and for the enforcement of the new by-laws. A $10,000 per year allowance should be sufficient to cover these costs as well as continuing 1 public education activities. I I 3-19 I 1 Unit Costs. Although the cost of purchase and installation/removal of the I weed screens will be smaller for larger acreages, in general, the capital cost is about $10,000 per acre, with an additional $600 per year per acre to maintain (install, remove, and clean) the screens. The other costs 1 cannot be broken into units. I 3.3.3 OPTION 3 - WEED HARVESTER, PUBLIC EDUCATION, AND SEPTIC SYSTEM MEASURES I Description I This option combines the septic system measures discussed under Option 2 I and either contracted weed harvesting or the purchase of a harvester. Although Lake Boon has a surface area of approximately 163 acres, total aquatic vegetation encompasses no more than 50-60 acres. The majority of B this weed growth (approximately 30 acres) occurs throughout the third basin I where shoreline development is generally sparse. There are several manufacturers of mechanical weed harvesting equipment. i These weed harvesters cut the vegetation to a maximum water depth of between 5 and 7 feet. Widths of cut vary from about 4 feet up to 10 feet for the larger machines. Storage capacity on a large 410-800 Harvester is I 800 cubic feet or approximately 14,000 Ibs. maximum. A small to medium size harvester such as a model HS-200 unit, would be capable of easily I harvesting the 15-25 acres of nuisance vegetation at Lake Boon. This machine has a productivity of about a quarter acre an hour or two acres per l day. In fact, two cuttings (30-50 acres total) per summer would be desireable and could be managed. A two-man operating crew would be required. A number of municipalities (Wellesley, Harvard, Westminster and I others) have purchased and are now operating equipment. Another option I would be to contract weed harvesting or hydroraking. l I I 3-20 l I I Cost Estimate Capital. The purchase price a weed harvester as discussed above is about I $35,000. A trailer conveyor system for disposal of the vegetation is an additional $10,000. Since this full amount should be fundable under the I Clean Lakes Program, the Town's share would be $11,250. Contracted weed 1 harvesting or hydroraking would not have any capital cost. Adding in the approximate $155,000 cost associated with the implementation of septic system measures and the 5 year well monitoring program brings the I total capital cost of this option with the purchase of a weed harvester to $200,000, of which $50,000 would be the Town's share with Clean Lakes I funding. With no weed harvester purchase, the Town's capital cost would be $38,750 for the septic system measures and well monitoring. I Operations and Maintenance. As with Option 2, the annual cost of administration would be about $10,000. The $10,000 per year administrative I costs would be expected to decline over time. I The annual costs associated with the purchase of a weed harvester are estimated at about $15,000 (not fundable) which would include operation, fuel, repairs, etc. The total O&M for this option would then be $31,250. I A typical contracted rate for weed harvesting would be about $22,500, including disposal (assuming approximately 25 acres and two cuttings). I Contracted hydroraking, which may have some carry over benefits from year to year, would be about $37,500 per year including disposal (assumes one t cutting, 25 acres). Unit Costs. Using a 25 acre area, the purchased weed harvester would have I an approximate annual cost of about $625/acre, while contracted weed harvesting and hydroraking would have annual costs of $900/acre and I $1,500-2,000/acre respectively, including disposal. I I I 3-21 I I 3.3.4 OPTION 4 - WEED HARVESTING, LIMITED WEED SCREENS, PUBLIC EDUCATION, I AND SEPTIC SYSTEM MEASURES I Description I This option combines the weed harvesting and septic system measures from Option 3 with the use of weed screens by individuals or groups of individuals. Weed screens were described under Option 2, with the main I differences here being that the Town would purchase (at a discount) enough of the screen to cover about three acres. The town would then resell the I material to individual homeowners at cost. The purchase of the weed screens would not be fundable under the Clean Lakes Program. Purchasers would install, maintain and repair the screens at their own expense, using i the material around private docks and swimming areas. I The septic system measures would be the same as in Options 2 and 3 but contracted hydroraking could be substituted for the purchase of a weed 1 harvester. Because the weed screens would be used in individual areas, the acreage to be raked could probably be reduced to about 16 acres. In some I years, hydroraking might not be necessary. I Cost Estimate Capital Cost. The capital cost of this option would be $30,000 for the I weed screen purchase and $155,000 for the septic system measures and well monitoring implementation. With funding, the capital cost would be $68,750, much of which could be recovered from individuals buying the weed I screens. I Operations and Maintenance Annual costs would include $22,500 to $30,000 to hydrorake about 15 acres and $10,000/year administration costs for I septic system measures. I I I 3-22 I t Table 3-3 shows an overall cost comparison of the four final I options. Using this table, and the descriptions of the four final options, the Lake Boon Commission selected Option 3 with minor modifications based 1 on its cost-effectiveness and applicability to the local situation. This option, along with the modifications, is described in the next section. I 3.4 PROPOSED PROJECT I 3.4.1 DESCRIPTION I The recommended project consists of Option 3 - Weed Harvester and Watershed Management Plan plus contracted hydroraking for one year as a short-term, interim measure. However, Step 3 (the private well sampling 1 program) would not be included since this is ongoing as part of a separate I project. The first part of the project would consist of purchasing a weed harvester by the Towns of Hudson and Stow, Of the total surface I area of the lake of approximately 163 acres, dense aquatic vegetation encompasses only about 50-60 acres. The majority of I this dense growth, around 30 acres, occurs throughout the third I basin where shoreline development is generally sparse. Mechanical weed harvesting equipment, made by several I manufacturers, cuts the aquatic vegetation to a maximum water depth of between 5 and 7 feet. Cutting width varies from about 4 feet to about 10 feet for larger machines. A small to medium size I harvester would be capable of easily harvesting the 15-25 acres of nuisance I vegetation at Lake Boon. This machine has a productivity of about a quarter acre an hour or two acres per day. Two cuttings (30-50 acres total) per summer would be I desirable and could be managed. A two-man operating crew would be required. For operation of the harvester, the two towns could jointly hire I staff for summers, or interested lake residents could share in the I I 3-23 I [OPTIONS 2,":lrf^ i i i 0.01 1.0 10.0 MEAN DEPTH (m) i 100.0 i L: AREAL PHOSPHORUS LOADING (fl/m2/yr) R: PHOSPHORUS RETENTION COEFFICIENT i T: HYDRAULIC RETENTION TIME (yr) i LAKE BOON i CAMP DRESSER & DIAGNOSTIC FEASIBILITY STUDY McKEE INC. TOWNS OF HUDSON AND STOW in association with i MASSACHUSETTS IEP, INC. EFFECTS OF FINAL OPTIONS ON TROPHIC STATUS TAB I I COST ESTIMATES OF FINAL OPTIONS Iptlon No Component Capital Cost Annual Cost Share Capital Share Annual Cost (if any) I 1 § Sewering $ 5.500.000 $600.000 $1,375.000 $600,000 • Dredging 5,000,000 . 1,250,000 $79,000/acre I Total $10.500.000 $600,000 $2.625,000 ) 600, 000 2 • Weed Screens i 450,000 $ 25.000 $ 122,500 * 25,000 $lo;oOO/acre • Septic System Measures I (Steps 1. 2, 4) 30.000 10.000 7.500 10,000 (Step 3) 125,000 _ 31.250 . I Total $ 605,000 J 35.000 $ 151,250 $ 35.000 3A • Heed Harvester Purchase $ 45,000 $ 15.000 $ 11,250 $ 15.000 $625/acre/yr • Septic System Measures (Steps 1. 2, 4) 30,000 10.000 7,500 10.000 (Steps 3) 125,000 _.. 31.250 I Total $200.000 $ 25,000 $50,000 $ 25,000 3B t Contracted $ 22,500 $ 5,625 . Harvesting (22.500)1 i900/*cre/yr I (-25 acres) • Septic System 155,000 10,000 38,750 10.000 Measures I Total $ 155.000 $ 32.500 $ 35.750 $ 15,525 . (32.500)1 3C • HydroraUng $ 37,500 $ 9,375 $15DO-2000/acre I (25 acres) (37.500)1 per year • Septic System 155,000 10.000 38.750 10.000 Measures I - ,^_^^^^_ —n inrr-Ti ,-- Total 155.000 47.500 38,750 19.375 . (47.500}J I4^ t HycJroraklng $22,500-30,000 $5,625-7,500 . $1500-2000 (15 acres) • (22. 500-30, 000 r acre/per year t Weed Screen 30,000 . 30.0002 10,000/acre 1 Purchase • Septic System 155.000 10.000 36.750 10.000 I Measures Total $ 165,000 $32,5QQ-$4Q,000 $68,750 S15,625-$17,500 ($32.500-40.000) Contracted weed harvesting and hydroraklng are eligible for funding, but are not preferred uses for Clean Lakes nioney--generally receiving very low priority. I In the cost'of weed screen purchase would be offset by individual purchase from Towns I I I operation with a designated Town staff person in charge of maintenance and I operations. For the interim, a contractor should be hired to hydrorake for the first summer before the remainder of the project is in place. The second portion of this option involves the implementation of a Watershed Management Plan to reduce/control leachate impacts on I the lake by 1) frequent pumping of septic systems to improve their efficiency; 2) requiring the upgrade of cesspools upon resale of t housing; and 3) the implementation of a public education program. i These steps are described below. Institute a Septic System Pumping Program t It is estimated that fewer than 47% of the homeowners around the lake pump their septic systems regularly, and as many as 27% of i homes may have cesspools. Based on this, an annual pumping program would increase the frequency of maintenance of existing i septic systems, thereby increasing their efficiency significantly. i There are several methods to implement a pumping program, however, a voluntary pumping program has been the most commonly used. This i could be set up similar to a garbage collection service, where the Towns bid out for the services of one or more pumping service i vendors to go through a list of homes on an annual basis and pump each one. Since the program would be voluntary, interested i citizens would be required to sign up for the program. At the end of the work, the vendor(s) would submit a ticket or i other record for each home pumped recorded with the address, date, depth of sludge, quantity of septage pumped, condition of the i system, and the location of the system access cover. Systems that could not be pumped for some reason would also be reported. i Annual bills would then be sent out to each of the homes. i i 3-25 t I Under Title 5, the Town of residence is responsible for providing a disposal site for septage. Assuming about 350 gallons per year I per septic system and 500 homes, this would be approximately 17S,000 gallons per year. A long-terra agreement with a nearby I wastewater treatment plant such as the Hudson plant would be advantageous to both Towns and would be the preferred method of I disposal. Because the entire area for pumping would be bid as a unit, or at I the most, one unit per town, the cost savings to homeowners over I hiring individual vendors should be significant. Require Cesspool/Septic System Upgrade Upon Resale I From the pumping program, a large part of the failing, inefficient systems will be dealt with, resulting in a significant reduction I in phosphorus loadings to the lake. One problem that will remain, however, are the grandfathered cesspools. Since the questionnaire I survey resulted in an estimate of 27% or more of the homes (about 145) may have cesspools, this could be a significant amount. I To deal with these, an amended by-law requiring the upgrade of cesspools upon resale could be adopted, in this way, cesspools t would gradually be converted into more efficient systems. One problem that should be noted is that many of these old systems are i associated with very small lots that cannot accept full size septic systems that meet Title 5 requirements. In these cases, a variance from Title 5 should be requested, rather than leaving the i system as is. i Implement a Public Education Program i As the final step in the implementation of this component, a i public education program should be developed to attempt to reduce i i 3-26 t the phosphorus loadings to septic systems and to reduce the I phosphorus loading from overland runoff. I This could include pamphlets or flyers discussing methods to reduce phosphorus use in detergents and fertilizers, as well as I lists of available phosphorus-free products. As part of the educational program, the Towns could provide individual homeowners I with information relative to cesspool and septic system operation. I 3.4.2 COST ESTIMATE A cost summary for the proposed project is given on Table 3-4, along with a I breakdown of capital and annual costs. The annual costs associated with the purchase of a weed harvester are I estimated at about $18,000 (not fundable) which would include operation, fuel, repairs, etc. Some administrative costs will also be borne by the I Towns for the billing/collections, etc. associated with the pumping program, and for the enforcement of the new by-laws. A $10,000 per year I allowance should be sufficient to cover these costs as well as continuing public education activities, so the total annual cost would be $28,000 per 1 year. I 3.4.3 SCHEDULE The overall schedule for the project is shown in Table 3-5. I 3.4.4 PUBLIC PARTICIPATION V The first public meeting for the project was held April 2, 1986. Copies of the meeting agenda, public participation handout, the sign-in list, and • newspaper articles are attached in the Appendix. The final public meeting was held on July 15, 1987 to discuss the results of the study. Press I releases, meeting agendas, and newspaper articles from the second meeting i™ are also in the Appendix. i 3-27 i 1 1 1 TABLE 3-4 1 COST SUMMARY OF PROPOSED PROJECT 1 Lake Boon Diagnostic/Feasibility Study I Capital Annual Share Share Component Cost Cost Capital Annual 1 A. Hydroraking $38,000 $9,500(1) (1 year only) i B. Watershed Management $30,000 $10,000 $7,500 $10,000 i Plan'2' C. Weed Harvester Purchase $50,000 $18,000 $12,500 $18,000 i and Operation i TOTALS $118,000 $28,000 $29,500 $28,000 i DWPC 3 year Monitoring $50,000 $12,500 ftProgram $168,000 $42,000 i • i (1) Hydroraking is eligibl e for funding but is not a prefered use for DWPC Clean Lakes money and generally receives very low priority. i (2) Components include development of bylaws for cesspool conversion and a public education program (capital cost) and the administration of a i septic system pumping program and a continuing public education program. i i 1 1 TABLE 3-5 IMPLEMENTATION SCHEDULE 1 LAKE BOON PHASE II 1 Milestone Date Task Responsibility October 1, 1987 Deadline for approved Camp Dresser & Phase I Final Report McKee Inc. and I IEP, inc. January 30, 1988 Deadline for Prioritizing Division of Water I for Funding Pollution Control (DWPC) May 15, 1988 Deadline for Local Towns of Hudson 1 Match Commitment and Stow May 31, 1988 Deadline for Full Towns of Hudson 1 Program Requirements and Stow Compliance September 1, 1988 Substate Agreement/ DWPC 1 Phase II October 3, 1988 Issue Phase II Towns of Hudson 1 Request for Proposals and Stow October 28, 1988 Deadline for Proposals Towns of Hudson 1 and Stow November 30, 1988 Selection of Consultant Towns of Hudson for Phase II and Stow 1 January 2, 1989 . Begin Pumping Program Consultant Voluntary Sign-up . Begin Development of B By-Law Revisions . Begin Development of 1 Public Education Program February 2, 1989 Begin Public Education Consultant 1 Program, including advertisement of voluntary 1 sign-up for pumping program 1 1 1 I April 3, 1989 . Hire hydroraking Towns of Hudson f contractor and Stow . Compile list of homes for I pumping program and advertise for bids for I pumping contractor May 1, 1989 . Hire pumping contractor Towns of Hudson to begin work and Stow I . Implement by-law revisions . Continue public education I program January 1, 1990 Purchase Weed Harvester Towns of Hudson I and Stow March 1, 1990 Advertise for weed harvester Towns of Hudson I operating staff and Stow June 1, 1990 Begin operation of Town- Towns of Hudson I owned harvester and Stow I 1 I I I i I I 3.4.5 MONITORING PROGRAM The implementation monitoring program should begin when,the work begins on the Watershed Management Plan implementation, currently scheduled for I January 1989. Sampling should occur on a quarterly, or seasonal, basis for the three year post-implementation period running until January of 1992. I Parameters for sampling should include the following: I 1) temperature profiles within one meter intervals 2) dissolved oxygen profiles within one meter intervals 3) pH I 4) total alkalinity 5) suspended solids I 6) dissolved solids 7) conductivity I 8) Kjeldahl nitrogen 9) ammonia nitrogen 10) nitrate nitrogen I 11) total phosphorous 12) total and fecal coliform bacteria I 13) turbidity 14) flow rate (either instantaneous or time-integrated) I 15) chlorophyll a I 3.4.6 ENVIRONMENTAL EVALUATION Since the project does not involve any construction, the only environmental I effects are positive and relate to water quality improvements relative to I the no-action alternative. a. Historical Commission. No approval is required since no potential I historic or archaelogic resources could be impacted by the project. b. Evaluation of Chemical Treatment. Use of chemicals is not involved I in the proposed project. I I 3-30 I I I c. Dredging Evaluation. Dredging is not proposed. d. Effects on fish and wildlife, wetlands or wildlife habitat. The prevention of water quality deterioration over time will have generally I beneficial effects on aquatic resources. Although weed harvesting removes some aquatic vegetation that may be used as cover for fish, I only the densest areas of growth are to be harvested, leaving adequate I amounts of vegetation for cover. None of the components of the proposed project, including weed harvesting, require Conservation Commission review under the Wetlands I Act or MEPA and U.S. Fish and Wildlife Service review. I e. Downstream Effects. None I f. Mitigation Measures. None required. I 3.4.7 RECREATIONAL PLRN Although the possible development of a recreational plan for Lake Boon was I discussed in the proposal for this project, expansion of current recreational uses of the lake was not considered desirable by interested residents who attended the first public meeting or by the Lake Boon I Commission. Because of this, no formal recreational plan to expand I recreational use at Lake Boon is included at present. I I I 1 I I 3-31 I I I PUBLIC MEETING AGENDA I lay f* Jehn»on Auditorium, In th* WHkw Bulk). l. Th* Mriornune* waa part ol lh« Tuesday, March 25 , 1986 Page 3 I •tefl photo bj K Hearing is tomorrow on Lake Boon study HUDSON — The Lake Boon Com- Gamp Dresser and McHee of Boston is cludes excessive weed growth, will be mission wUl hold a public hearing In performing the Btudy. W7ien complete. neither short-term nor inexpensive, ac- I It will identify various sources of de- cording to Commission Chairman Alan the selectmen's office of Town Hall at clining water "quality In the lake and Kattelfe. 7:30 p.m.. tomorrow. The slate is funding the current study The hearing will provide the commis- suggest corrective measures. along with local aid from Hudson and sion, its advisory commutes:, and resi- At the hearing, firm engineers will Slow. dents ot Hudson and Stow with up-to- present Interim findings and recom- For further Information, contact Alan I mendations and wlil solicit Input from Kattelle. Hudson commissioner at 562- date findings of the Lake Boon study, which has been underway since last those In attendance 9184 or Donald Hawkes. Stow commis- I fail. Solutions to the problem, which in- sioner. 562-6630. I I Editorial Page 14 Wednesday. March 26 , 1986 I 'Boon or bust' drive must not die in April I The concern that runs deeply. If quietly. In Hudson. Stow and neighboring communJUes Tor correcting the weed and pollution prob- lems In Lake Boon could end next month. I But It shouldn't. Chances are that when technlcaJ experts from Camp. Dresser and McKee of Boston present their Interim report on the health of the lake at a public meeting April 2. the recommended "cure" will In- I volve a lot more time, money and disruption that anyone really wants to face up to. The report, commissioned with Hudson. Stow and state funds by the Lake Boon Com- mission, is likely to point out that the trou- I blesome excessive weed growth In the fa- vored recreational lake In the area Is a symptom. The real problem. moat'Ukely. will turn out to be a combination of chemical run- I off from above-ground fertilizers and lawn treatments, and underground nitrate sources like leaky septic systems or sewer pipfp. Fbdng all that, as Commission Chairman AJan Kattelle has already indicated, will be I neither quick nor cheap. That fact that could tend to take some of the vigor out .of the pub- lic zeal for cleaning up Lake Boon. It must • not though. I It's time to toughen public determination to go for the long haul and to see through the campaign to clean Lake Boon. Even if the word April 2 (Hudson Town Hail. 7:30 p.m.] Is that it will take more time and money than I anyone wanted, = "° — Correction HUDSON — Yesterday's edi- it poll tions fncorrecty staled thai the I Lake Boon Commission will meet tonight in the Hudson Town Hall The meeting Is scheduled for Wednesday. AprlJ I 2 I I I I Lake cleanup I progress aired By DONALD ST. JOHN available," Hawkes said. "The I ws Sia*- Write; current study is partly state- funded; they picked up 60 percent Engineering consultants wilJ of the cost, and Stow and Hudson I outline their progress in a "weed split the other 40 percent. study" and in trying to come up "In the implementation phase, with a plan to clean plant-choked it's a 90 percenl-10 percent split, so Lake Boon at a hearing Wednesday the state bears most of the I night. burden," he said "Of course, it The lake's problem is well- depends on the bidding process, known, meaning that potential and the magnitude of the final solutions will be a primary topic of recommendations." I discussion at the 7:30 p.m. meeting A recent report by the in Hudson Town Hall, said Lake Metropolitan District Commission Boon Commission member Donald aimea at identifying potential Hawkes of Stow. wa ter sources to a void future I "It's a natural process of shortages included Lake Boon. nitrogens leaching into the water But although Hawkes said the through the sandy soils of septic lake has never had a coiiform systems from nearby houses," bacteria or any other serious Hawkes said. "Basically, it creates health problem, the weed and I fertilizer." algae problem is first on its The process, known as agenda. eutrophication, creates a healthy "We'll probably have about three breeding ground for both green possible solutions on the table at I weeds and algae, which have made the fall hearing, down from maybe parts of the lake almost "useless" 10 at this Wednesday's." he said. for recreational boating and "One might be a gold-plated swimming, Hawkes said. solution, which would restore the I "The perceived problem of lake to pristine condition weeds is most noticeable in the "You might also have a Band- shallower ends," he said. The lake Aid approach, to do the minimum was man-made about 150 years you can. The third would be I ago, and some basins are shallower something in the middle — maybe than others, he said. something over a phased period, to Consultants from the Boston minimize the cost impact," engineering firm Camp Dresser Hawkes said. I and McKee and IEP of Northboro, The lake lies mostly within Stow, which have been studying the lake with about one-third of its area in and its water quality, will be Hudson. The membership of the present at the Wednesday hearing commission parallels this: two I and another one in the fall, Hawkes members come from Stow, one said. from Hudson. There, they will discuss findings However, the membership of a to date and hear ideas for a technical advisory commission I feasibility study of ways to clean reversed the weight toward Stow, Lake Boon. slanting two-to-one toward Hudson I "There will be state funding residents, Hawkes said. I I I I PUBLIC MEETING AGENDA DIAGNOSTIC/FEASIBILITY STUDY I LAKE BOON I I INTRODUCTION • STUDY COMPONENTS • Diagnostic Study Sampling and Analysis Septic System Survey I Feasibil ity Study I Alternative Identification Preliminary Screening Selection of Best Alternative • Proposed Project I FINDINGS TO DATE I LIST OF TECHNOLOGIES • ALTERNATIVES DEVELOPMENT i SUMMARY i OPEN DISCUSSION i i i I OVERVIEW I LAKE BOON I DIAGNOSTIC/FEASIBILITY .STUDY The purpose of this meeting is to present the results of work to date on the Lake Boon Diagnostic/Feasibility Study, and to describe some of the I methods that are available for correcting problems in the lake. Lake Boon has been studied extensively in the past. Because of this, only I a limited amount of new data is being collected to make sure that no significant changes have occurred since the last study and to provide more I detail in particular areas. The following results have been obtained: • Water quality results from this study have been generally consistent with those of the Division of Water Pollution Control study of 1979-80. However, the results from samples to be I collected during the growing season will be necessary to fully confi rm this. I • Aquatic weed problems appear to be the result of shallow depths, rich organic sediments and high nutrient levels. I • Two of the primary sources of nutrients to the lake that may be controllable are 1) runoff from roads and residences and 2} septic system leachate that enters the lake. I The main purpose of this study is to develop a plan for the restoration of Lake Boon. This plan must take into account the unique aspects of the I lake, and it must be practical and affordable. A number of technologies for lake restoration are presented on the next page, representing a wide range of cost and effectiveness. I Several feasible alternatives will be selected out of this list of alternative technologies. These that are selected will then be evaluated further and combined into three or four alternative "projects". These I "projects" which will represent a range of cost and degrees of effectiveness, will be presented at the second public meeting to be held next fall. Following public input, the proposed project can then he I selected. I I I I I I I LIST OF TECHNOLOGIES I PHYSICAL BIOLOGICAL » Dredging • Fish Removal and Restocking I • Weed Harvesting • Zooplankton Manipulation I • Aeration • Wetlands Treatment • Mixing I t Diversion of Stormdrains CHEMICAL • Treatment of Inflows • pH Adjustment I t Benthic Barriers • Algicides I t Sewer Inspection t Herbicides • Sewer Instal1ation • Chemical Precipitation I t Dilution • Light Blockage • Drawdown • Trace Chemical Addition I t Watershed Management • Flyash I • Power Boat Regulation CULTURAL I • Public Education Programs I I I I I I I LOCUS MAP LAKE BOON HUDSON MASSACHUSETTS I I I BASELINE DATA I Location of Sampling Stations I Lake Boon I I I I I I I I I I I I I I I I I I I I I I I I I I I WATER BODIES SEVERE LIMITATION I DUE TO SLOW PERC RATE SEVERE LIMITATION I DUE TO HIGH SLOPE SEVERE LIMITATION I DUE TO HIGH WATER TABLE FIGURE 2500 5000 FT, 1000 I LAKE BOON I I SOILS LIMITATIONS I TO SEPTIC SYSTEMS (J) I E ?n. I I MEETING MEMO I PUBLIC MEETING, LAKE BOON, HUDSON TOWN HALL April 2, 1986 7:30 p.m. I The meeting was opened and introductions were made by Mr. Alan Katelle of the Lake Boon Commission. About 35 persons were in attendance. The meeting was well advertised through newspaper ads and flyers distributed to I shoreline residents. Eileen Pannetier from Camp Dresser & McKee Inc. and Scott Bailey from IEP, Inc. presented the basic components of the Diagnostic/Feasibility study of Lake Boon as well as the results of the I study to date. Various types of technologies used on lakes were presented and the preliminary screening of alternatives was discussed. Alternative technologies not suitable for Lake Boon were eliminated, and the remaining alternatives were described. The presentation consisted of a slide show, I handouts, and a discussion period moderated by Mr. Katelle, A copy of the handout, the advertisements for the meeting, and the sign up sheet are I attached. Comments and questions raised during the discussion period are summarized below. I t We should look at scraping (dry dredging) of individual basins, possibly by draining one basin at a time. I . • Treatment of polluted inflows (from overland runoff) should be examined using some type of basin. I • Dredging will be too expensive, and harvesting only treats the symptoms, • Some questions were raised about the groundwater flows and reasons I for low flushing rate of the lake. Also questions on differences between soils considered suitable from the standpoint of lakes as opposed to soils that have rapid percolation rates and pass the I percolation tests. • There is some new information that should be obtained from SCS on I soils potential. Also new groundwater data from MAPC. • Methods and techniques that can be used by individual residents to improve their shoreline conditions should be addressed, such as I weed screens and other methods. • Interest in the use of dye was expressed but with many concerns I over the appearance of the dye and transparency problems. • White Pond should be compared for types and extent of vegetation I since it does not have the shoreline residences that Lake Boon has I and does not appear to have the same weed problems also. I I I I • Several residents felt that sewering of the shoreline homes was necessary as a long-time measure, others felt it would be too expensive. I • Dick Gelpke from the Lake Boon Commission mentioned that the progress reports were available for public review, and also had several comments on the most recent progress report, including: the I land use map needs some revisions to reflect new developments; the town line shown on several maps was relocated slightly and should be revised; it should be noted that Hudson enacted conversion by-laws I recently. • Don Hawkes of the Lake Boon Commission asked what would happen to the Lake if nothing is done, and the gradual filling in and further I eutrophication of the Lake was discussed. I I I I I I I I I I I I I I PRESS RELEASE FOR IMMEDIATE RELEASE For further information call: I Donald Hawkes - 562-6630 July .7, 1987 Alan Kattelle - 562-918U I Keith Myles - 562-6109 I LAKE BOON COMMISSION TO HOLD PUBLIC HEARING I Water quality and aquatic weed growth in Lake Boon, which has been studied I for nearly a year and a half, will be the focus of a public hearing to be held I at the Stow Town Hall, 7:30 P.M., Wednesday, July 15, 1987. The Lake Boon Commission oversees the local body of water, which lies partly in Stow and I partly in Hudson. The study, jointly funded by the state's Clean Lakes Program and both I towns, seeks to identify causes of deteriorating water quality and to recommend action which may be taken to improve the Lake's condition. Representatives of I the consulting firm of Camp, Dresser and McKee will present their findings to I concerned area residents/property owners. The Commission has also invited state officials and members of Boards and Commissions of both towns to hear the I findings and recommendations of the study. "The future of this recreational resource, as well as area property i values, depends upon the action taken as a result of this report," stated i Commission Chairman Donald Hawkes of Stow. "We hope to gain wide support for action which can improve, and then maintain, the water quality of Lake Boon," i * i -- 30 — i i I THE LAKE BOON COMMISSION HUDSON AND STOW, MASSACHUSETTS I LAKE BOON COMMISSIONERS: I Donald Hawkes - Stow Alan Kattelle - Hudson I Keith Myles - Stow I June, 1987 Dear Lake Boon Area Resident: I "Our lake is dying - parts of it will be a swamp in our lifetime." I "There's no problem with Lake Boon - just a few weeds." Do either of these paraphrased statements reflect an accurate picture of the condition of our valuable resource? As in the case of most general statements, the I truth probably lies somewhere in the middle. The Lake Boon Commission has spent a year and a half and a considerable sum of money in studying the lake's condition, and is now calling a public hearing to I hear the consultant's report and recommendations. Ample time will be available to discuss these issues. The next step in the process of moving toward a cleaner lake - one which will I be available to us as a recreational resource as well as increasing our property values - is to apply to the state for funding to begin to implement the study's findings. This will require appropriation by the Town Meetings of both Hudson and I Stow of 25* of the total funding sought. If we are to end up with any result from this long process except a consultant's final report left to gather dust on a shelf, we must have significant public support. Thus we urge all lake area residents I and/or property owners to attend the public hearing listed below. I Thank you for your support. I PUBLIC HEARING I Wednesday, July 15, 1987 - 7:30 P.M. Stow Town Hall I I I I I I I I I I I PUBLIC MEETING July 15, 1987 I Lake Boon Study ™ Towns of Hudson & Stow, Massachusetts I . and the Lake Boon Coirrnission i i i i i i i i I I I AGENDA I LAKE BOON DIAGNOSTIC/FEASIBILITY STUDY I Second Public Meeting I I. INTRODUCTION Lake Boon Commission I II. STUDY COMPONENTS Camp Dresser & McKee Inc and IEP, Inc. Diagnostic Study f Feasibility Study I III. PROPOSED PROJECT Camp Dresser & McKee Inc I and IEP, Inc. I IV. OPEN DISCUSSION Lake Boon Commission I I I I I I 1 I I I I • LAKE BOON DIAGNOSTIC STUDY GENERAL INFORMATION M o Data Collection o Watershed Description f o Recreational Description ^ o Geological Description i™ o Historical Account INVESTIGATIONS I o Physical Measurements o Water Quality Sampling ™ • o Storm Surveys • o Sediment Analyses i o Source Investigations i i i i i i FIGURE I I LAKE BOON WATERSHED I I I I I I I I I I I I I I I I 0 1000 2500 5000 FT I I I I I I I FIGURE 6 I SAMPLING STATIONS 1985-1986 I LAKE BOON I HUDSON/STOW. MA I I I I I I I I I I I I I 0 1000 2000 6000 FT. I I I I i LAKE BOON FEASIBILITY STUDY i ALTERNATIVE IDENTIFICATION AND EVALUATION i o Identification of All Possible Alternatives o Preliminary Screening I o Selection and Evaluation of Best Alternatives - Effects on Water Quality , - Overall Effectiveness I - Cost/Benefit Ratio i - Probability of Implementation DEVELOPMENT AND DETAILED EVALUATION OF PROPOSED PROJECT m o Cost Effectiveness • o Projected Water Quality/Recreational Improvements o Impacts on Annual Nutrient Budget • o Permitting and Monitoring Program i i i i i i i I I SUMMARY OF PROPOSED PROJECT I Lake Boon Diagnostic/Feasibility Study I Component Description I A. Hydroraklng Contracted for 1 year only. Consists of aquatic vegetation by uprooting. May have carryover I benefits to next year. Purpose 1s to provide I interim relief for aquatic weed problens. 1 B. Watershed Management Purpose is to reduce/control pollution 1n Lake Plan Boon over the long term. Steps include a voluntary pumping program for septic systems; new I Town bylaws requiring the upgrading of cesspools upon resale of housing; and the Implementation of 1 a public education program. I C. Weed Harvester Plan Weed harvester for annual summer use to be I purchased and operated for long-term control of I nuisance aquatic vegetation. 1 I I I I I I I I COST SUMMARY OF PROPOSED PROJECT I Lake Boon Diagnostic/Feasibility Study Capital Annual Share Share I Component Cost Annual Cost Capital A. Hydroraking $38,000 $9,500- I •ao nnnl 1 ' (1 year only) I B. Watershed Management $30,000 $10,000 $7,500 $10,000 I Plan'?' C. Weed Harvester Purchase $50,000 $18,000 $12,500 $18,000 I and Operation I TOTALS $118,000 $28,000 $29,500- $28,000 58,000 I (1) Hydroraking Is eligible for funding but is not a prefered use for DWPC I Clean Lakes money and generally receives very low priority. .(2) Components Include development of bylaws for cesspool conversion and a I public education program (capital cost) and the administration of a I septic system pumping program and a continuing public education program I 1 1 I I I I 1625 Trapelo Road I Wai than, MA 02154 I July 20, 1987 Mr. Donald Hawks, Chairman Lake Boon Commission I Stow, MA 01775 Dear Mr. Hawks: t We attended the public hearing held on July 15, 1987 and found the hearing to be both encouraging and informative. Long time residents of the lake, such as ourselves, fully realize that the life of Lake Boon I is limited if the weed problem/pollution is not reversed. We applaud the Commissions' efforts in seeking a solution to the weed I infestation. Likewise we endorse the program proposed by Camp, Dresser & Me Kee as a result ot their diagnostic/feasilility study. Implementation of such a program will serve as a major step toward the preservation of: I Lake Boon. Please plan on our support, financial and other, in your effort to preserve I this unique and beautiful body of water. I Very truly yours, Louise Butler I William C. Butler Hallock Point Road 568-8497 1 890-2828 cc: ' Eileen Pannener I Camp, Dresser & Me Kee I I I 1 I I I FORM DWPC-623-01 APPENDIX C I COMM3NWEALTH OF MASSACHUSETTS DEPARTMENT OF ENVIRONMENTAL QUALITY ENGINEERING I DIVISION OF WATER POLLUTION CONTROL CLEAN LAKES PROGRAM I REQUEST FOR ASSISTANCE I 1. State tha legal name of the lake or pond and its specific location. Lake Boon. Located in the northeastern portion of Hudson and the I southeastern portion of Stow, Massachusetts. 2. State tne ownership of the lake or pond. If «ater rights are privately I owned thefi tms must also oa stated. I Town of Hudson and Town of Stow. I 3. Describe in detail the public access area(s) inclading its locacion relative to the lake and public road.;ay. This description moot include a locus map I clearly indicating tne puolic access areats). Public access off Sudbury Road in Stow. Public beach off Sudbury Road for I Stow residents. 9 4. Descries tne recreational uses of the lake. Be sure to include historical usesH=.S;T, i fP differenf4 i r t-^i F-= n t- I Swimming, boating, fishing, skating. I 5. Describe the particular problems and nuisance conditions affecting trie I lake. I Excessive aquatic weed and algal growth. I I I I FORM DWPC-623-31 I 6. What type of project do you ssax to I Phase II Implementation I 7. Sucmitted by: I Camp Dresser & McKee Inc. for I Lake Boon Commission 53 Lakeside Avenue Applicant's Name (print or type) Address I Hudson, MA 01749 I Title City/Town (617) 562-3535 I Tel. to. I Signature Camp Dresser & McKee Inc> Return to: lakes Section, Division of Water Pollution Control, Lyman School, t Wescvie* Building, Westborougn, Massachusetts 01581 1 I I I I I I '•vs^j-"5^ •>^^1 ' ^\\r 3-=-_- v ;^^ rj^u _i— ~ " PUBLIC ACCESS HUDSON AND STOW 1/2 MASSACHUSETTS a MILE LAKE BOON LIMNOLOGIC DATA i I i I i I I I Table Al. Lake Boon, pH Analyses (standard units) I - - otation wuraoer - - - Date 1 2 3 4567 I surface bottom surface bottom I 10/29/85 6.8 6.8 6.9 7.0 NA 6.1 7.0 6.9 6.9 01/28/86 6.4 6.4 5.7 6.5 4.5 5.6 6.6 6.0 6.4 I 04/08/86 6.6 6.4 6.6 6.5 4.8 5.9 6.6 NA 6.6 07/29/86 7.4 6.3 7,1 6.6 4.7 5.9 7.2 NA 7.0 I NA = No sample taken , dry inlet I Table A2 , Total Alkalinity Analyses (mg/1) I Lake Boon I Date 1 2 3 4567 surface bottom surface bottom I 10/29/85 11 11 11 11 NA 8.8 11 9.4 10 01/28/86 7.0 8,9 3.5 9.3 <1 2.7 8.3 9.3 4.8 I 04/08/86 11 8.8 10 8.36 1.81 5.85 11 NA 9.04 I 07/29/86 9.9 16 9.9 12 2.2 6.4 9.9 NA 7.0 I NA = No sample taken, dry inlet I I I I I I I Table A3. Lake Boon, Total Suspended Solids Analyses (mg/1) I , IJ.UU »UUI.UtSL - - Date 1 2 4 5 6 7 I 1 surface bottom surface bottom I 10/29/85 6.0 0.8 <0.4 0.4 NA 2.0 1.6 1.6 0.8 01/28/86 1.6 1.2 2.4 6 5.3 4 2.4 18 0.4 I 04/08/86 <0.4 5.2 0.8 2 6.8 0.8 1.2 NA 3.6 I 07/29/86 4.0 8.0 5.2 7.0 16 5.0 4.5 NA 5.6 I NA = No sample taken, dry inlet I Table A4, Lake Boon, Total Dissolved Solids Analyses (mg/1) Station Number I Date I 1 3 4 5 6 7 surface bottom surface bottom I 10/29/85 49 25 49 49 NA 76 53 65 68 01/28/86 35 59 32 64 45 45 35 80 32 I 04/08/86 55 53 55 56 116 60 57 NA 62 I 07/29/86 108 63 67 71 187 124 61 NA 76 I NA = No sample taken, dry inlet I I I I Table A5. Lake Boon, Turbidity Analyses (KTU) — — — -- — — __o (.a*. J.uu iiuiuuei. — - — — — - — Date I 2 345 6 Z surface bottom surface bottom 10/29/85 2.5 2.5 <2 3.5 NA <2 <2 4 <2 01/28/86 <2 2 84 11 <2 <2 32 <2 04/08/86 <2 3 33 442 NA <2 07/29/86 4 2 24 2 2 <2 NA <2 NA = No sample taken, dry inlet Table A6. Lake Boon, Conductivity Analyses (umhos/cm) Date 1 1 145 i Z surface bottom surface bottom 10/29/85 93 93 93 91 NA 117 95 87 91 01/28/86 64 81 47 100 55 51 76 129 51 04/08/86 86 84 87 84 69 82 86 NA 79 07/29/86 91 96 94 96 80 137 96 NA 86 NA = No sample taken, dry inlet I I I Table A7. Lake Boon, Chloride Analyses (mg/1) I Dia.nun iNumutsi. - Date 1 2 3 4567 I surface bottom surface bottom 10/29/85 16 16 17 18 NA 21 16 16 16 I 01/28/86 17 21 11 24 13 13 22 39 14 I 04/08/86 18 18 19 18 15 15 19 NA 18 I 07/29/86 23 20 21 22 21 32 21 NA 17 I NA = No sample taken, dry inlet I Table A8 Lake Boon, Kjeldahl-Nltrogen Analyses (mg/1) Date 1 2 3 4567 I surface bottom surface bottom I 10/29/85 0.60 0.61 0.66 0.84 NA 0.48 0.64 0.75 0.65 01/28/86 0.28 0.35 0.91 0.52 0.84 0.70 0.86 0.91 0.67 I 04/08/86 0.25 0.21 0.24 0.32 3.4 0.25 0.26 NA 0.25 I 07/29/86 0.34 0.45 0.48 0.39 2.2 0.20 0.37 NA 0.16 I NA = No sample taken, dry inlet I I I I 1 1 1 Table A9. Lake Boon, Ammonia-Nitrogen Analyses (mg/1) 1^B Date 1 2 34567 surface bottom surface bottom 10/29/85 0. 13 0.21 <0. 10 <0. 10 NA <0. 10 <0. 10 <0. 10 <0. 1 1 01/28/86 <0.10 <0.10 0.14 <0.10 0.25 <0.10 <0.10 0.19 <0.10 04/08/86 0.014 0.015 <0.01 <0.01 0.011 0.042 <0.01 NA <0.01 07/29/86 <0.010 <0.010 <0.010 0.017 0.034 0.019 <0.010 NA <0.010 1 NA = No sample taken, dry inlet 1 Table A10. Lake Boon, Nitrate-Nitrogen Analyses (mg/1) 1 Date 1 2 34567 surface bottom surface bottom 1 10/29/85 0.05 0.09 0.08 0.08 NA 0.88 0.09 <0.012 <0.012 01/28/86 0.10 0.16 0.14 0.21 0.07 0.22 0.10 0.01 0.04 1 04/08/86 0.16 0.12 0.069 0.11 0.052 0.28 0.071 NA 0.026 07/29/86 0.08 0.14 0.13 0.03 0.10 1.4 0.03 NA 0.03 • 1 NA = No sample taken, dry inlet 11 11 11 11 11 I I I Table All. Lake Boon, Total Phosphorus Analyses (mg/1) I _ _ station Number - I Date 1 2 surface bottom surface bottom I 10/29/85 0.04 <0.01 <0.01 <0.01 NA * * 0.03 <0.01 01/28/86 <0.01 <0.01 0.01 <0.01 0.06 <0.01 <0.01 0.04 <0.01 I 04/08/86 <0.01 0.015 <0.01 0.011 0.30 0.014 0.013 NA <0.01 07/29/86 <0.01 0.03 0.01 <0.01 0.28 <0.01 <0.01 NA <0.01 I NA = No sample taken, dry inlet I * No analysis available due to lab error I Table A12. Lake Boon, Total Coliform Analyses (colonies/100 ml) I Station Number I Date I12342 3 5 6 7 10/29/85 0 0 NA 0 0 0 0 I 01/28/86 0 27 11 22 4 106 1 04/08/86 0 6 5 6 5 NA 1 I 07/29/86 <10 40 * 2,500 50 NA irooo I NA = No sample taken, dry inlet I * = confluent growth I I I I I I Table A13. Lake Boon, Fecal Collform Analyses (colonies/100 ml) I ------o La nun nuuiuei ------Date 1 23456 7 I 10/29/85 3 0 NA 0 1 1 0 I 01/28/86 0 24 1 A 0 0 4 I 04/08/86 0 2 0 4 2 NA 0 I 07/29/86 * * * * * NA * NA = No sample dry inlet I * = confluent growth I Table A14 . Lake Boon, Iron Analyses (mg/1) I Date 1 2 345 6 7 I surface bottom surface bottom 10/29/86 0.26 0.26 0.17 0.12 NA 0.30 0.15 0.43 * I 01/28/86 0.05 0.05 0.11 0.21 0.45 0.14 0.28 7.2 0.27 I 04/08/86 0.08 0.18 0.17 0.21 1.8 0.31 0.10 NA 0.14 07/29/86 <0.02 0.15 0.08 0.34 3.0 0.21 <0.02 NA <0.02 * = No analysis due to lab error I NA = No sample taken, dry inlet I I I I Table A15. Lake Boon, Chlorophyll-a (mg/m3) and Secchi Disc Transparency (m) Date Station 1 Station 2 Station 7 chlorophyll-a Secchi Disk chlorophyll-a Secchi Disk Secchi Disk 10/29/85 9.6 3.0 8.7 2.5 3.2 01/28/86 3.59 NA 5.45 NA NA 04/08/86 11.0 2.7 8.6 2.7 2.6 07/29/86 16 1.7 14 1.7 6.0 NA = Secchi disk not measured at ice cover I I I I Table A16. Lake Boon, Phytoplankton Analyses (cells/ml); Station 1 10/29/85 01/28/86 04/08/86 07/29/86 I Bacillariophyceae "diatoms" Amphora 13 I Asterionella 27 40 Cocconeis 80 Cyclotella 93 40 20 I Fragilaria 27 Navicula 13 40 80 Synedra 53 20 I Tabellaria ______60 Subtotal 199 107 120 180 I Chlorophyceae "green algae" Ankistrodesmus 27 40 I Arthrodesmus 80 Chlamydomonas 13 160 40 Chlorella 40 40 I Chlorococcum 13 Closteriopsis 53 40 , 40 20 Elakatothrix 67 40 40 I Gloeocystis 93 140 Pediastrum 20 20 Oocystis 20 60 Radiococcus 20 I Scenedesmus 13 13 120 Schroederia 60 20 Sphaerocystis 40 133 180 220 I Staurastrum 13 20 I Subtotal 239 319 640 760 Chrysophyceae "other pigmented algae" I Chrysococcus 200 Dinobryon 27 173 40 20 Mallomonas 13 __ — K _— — ; ===== I _ = = — — — — 5_K_S — _ = — — — — , I Subtotal 40 173 240 20 I I I I Table A16. (continued) Cryptophyceae I Cryptomonas pn ===BE=E=====S! CE = Subtotal o 80 Cyanophyceae "blue green algae" I Anabaena 27 20 840 Aphanocaspsafcolonies/ml) 27 20 Gloeotrlchia 20 I Oscillatoriaf filaments/ml) 13 Subtotal 67 20 880 I Euglenophyceae/Dinophyceae unidentified 13 Subtotal 0 13 0 0 I Total (cells/ml) 545 625 1020 1920 I Total genera 17 11 14 22 Note: Colonial and filamentous algae are counted as natural units/ml. Algae I that occur as single cells are counted as cells/ml. I I I I I I I 1 1 1 1 Table A17. Lake Boon, Phytoplankton Analyses (cells/ml); Station 2 10/29/85 01/28/86 04/08/86 07/29/86 Bacillariophyceae 1 "diatoms" Asterionella 20 Cocconeis 13 Cyclotella 40 Diatoma 33 Eunotia 27 Fragilaria 53 20 Navicula 40 27 Synedra 40 20 : Tabellaria 13 13 20 Subtotal 186 53 80 40 1 Chlorophyceae "green algae" Ankistrodesmus 60 Arthrodesmus 20 Carteria 40 Chlamydomonas 200 80 Chlorella 27 60 Closteriopsis 40 Closterium 27 Elakatothrix 60 Gloeocystis 120 Golenkinia 20 Oocystis 13 40 Sphaerocyctis 40 180 Subtotal 107 267 120 620 Chrysophyceae 1 "other pigmented algae" Chrysococcus 173 20 Dinobryon 60 80 1 Mallomonas 27 40 Unidentified 40 Subtotal 11 173 160 80 Cryptophyceae Cryptomonas 27 60 1 Subtotal 0 27 0 60 I I I Table A17. (continued) Cyanophyceae I "bluegreen algae" Anabaena 13 660 I Aphanocaspsa (colonies/ml ') 13 Subtotal 26 0 0 660 I Euglenophyceae/Dinophyceae Euglena 13 13 I unidentified 13 I Subtotal 13 26 0 0 Total (cells/ml) 359 519 360 1400 I Total genera U 9 9 13 I Note: Colonial and filamentous algae are counted as natural units/ml. Algae that occurs as single cells are counted as cells/ml. I I I I I I I I 1 1 1 Table A18, Vhite Pond, Phytoplankton Analyses (cells/ml); Station 7 1 10/29/85 01/28/B6 04/08/86 07/29/86 Bad liar iophyceae 1 "diatoms" Cyclotella 13 40 Diatoma 27 1 Fragllaria 13 Frustulia 13 Melosira 27 Navicula 40 93 80 120 1 Synedra 53 133 300 Tabellaria 27 60 1 Subtotal 200 239 480 120 Chlorophyceae 1 "green algae" Ankistrodesmus 20 . Anthrodesmus 20 13 1 Carteria 13 Chlamydomonas 120 13 Chlorella 13 140 146 1 Cl_oj_te_r_ i ops_l s 80 40 13 Euastrum 13 Oedogonium 40 1 Oocystis 53 . Scenedesmus 13 Sphaerocystis 53 1 Ulothrix 20 Unidentified 20 1 Subtotal 133 53 300 317 Chrysophyceae 1 "other pigmented algae" Centritractus 146 27 100 Chrysococcus 67 13 80 1 Dinobryon 226 1000 Mallornonas 13 Ochromonas • • 80 1 0 Subtotal 226 266 1260 Cr^ptophyceae 1 Cryptomonas 13 1 Subtotal 0 0 0 13 I I I Table A1B. (continued Cyanophyceae I "blue green algae" I Aphanocasp_sa (colonies/ml ) 13 Subtotal 13 0 0 0 I Unknown Unidentified 13 I Subtotal 13 0 0 0 I Total (cells/ml) 585 558 2080 450 I Total genera 15 8 14 10 I Note: Colonial and filamentous algae are counted as natural units/ml. Algae I that occur as single cells are counted as cells/ml. I I I I I I I I I I I Table A19. Lake Boon, Temperature (°C) - Dissolved Oxygen (mg/1) - Saturation (%) I In-Lake Station #1 - I Date Surface 1m 2m 3m 4m 5m 6m 10/29/85 12.8 12.8 12.8 12.8 12.8 12.8 12.5 8.9 8.8 8.8 8.7 8.7 8.7 8.8 I 84 83 83 82 82 82 82 01/28/86 0.2 2.1 4.3 4.5 4.7 4.7 4.7 11.6 8.9 7.5 6.8 6.6 6.3 6.1 I 80 65 58 53 51 49 47 04/08/86 10.0 10.0 10.0 10.0 10.0 10.0 9.0 I 10.2 10.2 10.2 10.2 10.2 10.2 7.8 90 90 90 90 90 90 87 07/29/86 26.0 26.0 26.0 26.0 24.2 21.6 18.9 I 8.9 8.8 8.8 9.9 5.0 0.7 8.9 I 109 109 107 107 116 57 7 I I I I I I I I I 1 1 1 Table A20. Lake Boon, Temperature (°C) - Dissolved Oxygen (wg/1) 1 Saturation (X) 1 Date Surface 1m 2m 3m 10/29/85 11.5 11.5 11.3 11.3 9.7 9.7 9.7 9.8 1 88 88 88 89 01/28/86 0.5 3.2 4.0 3.6 1 10.0 9.6 9.6 9.0 69 72 73 68 1 04/08/86 10.2 10.2 10.2 10.2 9.8 9.8 9.9 9.8 87 87 88 87 1 07/29/86 26.0 26.0 26.0 25.0 8.7 8.6 8.6 4.4 1 106 105 105 52 1 t 1 1 1 1 1 1 1 I I I Table A21. Lake Boon, Temperature (°C) - Dissolved Oxygen (mg/1) Saturation (X), Inlet and Outlet Stations I ------station Humuer - - - - Date 3 4 5 6 I 10/29/85 NA 10.7 11.1 8.9 NA 3.3 7.9 9.9 I NA 29 71 85 01/28/86 0.1 0.6 4.2 NA 11.0 12.6 8.8 NA I 75 90 68 NA 04/08/86 7.8 7.5 10.0 NA 6.8 8.9 10.3 NA I 57 73 91 NA 07/29/86 20,8 15.9 26.0 NA 3.0 8.2 8.4 NA I 82 102 NA 33 I NA - No sample taken, dry inlet I I I I I 1 I I I 1 1 I Table A22. Vhite Pond, Station 7 - Temperature (°C) - Dissolved Oxygen (mg/1) Saturation (£) 1•• Date Surface Mid depth Bottom 10/29/85 13.5 13.6 13.4 9.0 9.0 8.8 1 86 86 84 01/28/86 0.8 4.2 4.4 1 10.3 7.3 3.8 73 56 29 04/08/86 10.0 10.0 7.6 1 10.6 10.5 10.0 94 93 84 1 07/29/86 25.5 25.8 21.2 8.3 8.1 7.9 1 100 98 87 1 1 1 1 1 1 1 1 1 I I I I Table A23. Lake Boon, Flow Measurements (cfs) Date 3 (inlet) 4 (inlet) 5 (outlet) 6 (inlet) I 10/29/85 NF LF 0.024 NF 01/28/86 0.43 0.80 LF NF I 04/08/86 0.01 0.70 2.20 NF I 07/29/86 LF 0.06 1.10 NF LF • No measurement because of low flow velocity. I NF - No flow, inlet dry I I I I I I I I I I I I I I I I I I • GLOSSARY OF TERMS i I i i i i i i i i i I I GLOSSARY OF TERMS I Aeration - The mixing of air with water to increase dissolved oxygen I levels. Sometimes used in lakes to remove thermal stratification. Algae bloom - The sudden growth of algae, often resulting in nuisence I conditions. Aquatic habitat - A waterbody supporting plant and animal life. I AreaT - Pertaining to surface area. The "area!" extent is measured in acres, hectares, square feet, etc. Bathymetric - Pertaining to water depth. A bathymetric map is a contour I map of the pond or lake bottom. Bedrock geology - The consolidated rock that generally underlies surficial I deposits. Biological treatment - Manipulation of plant or animal life to effect I change, e.g., the use of weed-eating fish. Catch basin - A basin for the collection of storm runoff, often a concrete I box structure. Chemical stratification - Usually refers to layers of water having I different concentrations of a given chemical, e.g., chloride. Chemical treatment - The use of chemicals to control/reduce problems such as excessive aquatic weeds. I Conceptual design - Selection of the major components of a system. Cost-effectiveness - A measure of benefits received in relation to their I cost. Data management - Storage and retrieval of information. In this study it usually refers to computerized storage and manipulation of water quality I data. DEQE Standard Operating Procedures - Methods established by the State I Department of Environmental Quality Engineering for sample collection, etc. during lake studies. I Dewatering - Usually refers to the removal of water from dredged material. Drawdown - Lowering the water level of a pond or lake, usually over the I winter months. I I I I Dredging - Removal of bottom sediments from a waterbody. Erosion controj^ - The reduction of soil and sediment losses. In lake studies it usually refers to prevention of silt loading to the pond or t lake. Eutrophication - Refers to the process where the excessive addition of I nutrients, organic matter or silt to lakes increases biological production and decreases volume. I Exotic species - Species of animals or plants that are not native to an area. • Export coefficient - A number that characterizes the amount of nutrients * or pollutants that originate in a given area. i Fertilization - The addition of plant nutrients to the soil or water. Flushing rate - The number of times the water in a lake is replaced in a i given time. Genus (plural genera) - A group of related species. i Geohydrologist - A scientist that studies groundwater. Groundwater - Water that lies beneath the ground surface, filling cracks i and pores in rocks and soil. Hydraulic dredging - Sediment removal by pumping in a liquid slurry form, i Hydrogeologist - A scientist that studies groundwater. Hydrologic budget - A summary of the water that enters and leaves a system i such as a lake. Implementation project - The project proposed for Phase II funding under i the state DEQE Clean Lakes Program. In-lake management - The control of nutrients and pollutants after they enter a lake. i Infiltratlon - The movement of water into the soil. Input/output model - Usually refers to phosphorus models where inputs or i outputs can be modified to project future conditions under different scenarios. i Land use classification - The description of an area by major use such as residential or commercial land. Landscape architect - A design professional concerned with planning i outdoor areas. i i I Leachate plume - Contaminants transported by groundwater. Usually refers I to a "slug" having higher concentrations than the surrounding groundwater. W Limnologist - A scientist in the study of lakes. Macrophyte - A non-microscopic aquatic plant, such as a pond lily. I Mechanical dredging - Sediment removal with excavation equipment such as backhoes and draglines. I Mitigation - A reduction in severity of impacts. Mixing - Usually used in lakes to "break up" thermal stratification and • mix the layers of the lake. Model - A mathematical representation of a natural process such as eutrophication. - Their use is to establish existing conditions and then I project different future conditions. Morphometry - The physical properties of a lake such as surface area and I volume. Non-point sources - Sources of pollutants that occur over a large area, I such as overland runoff. Nutrient - Substances such as nitrogen and phosphorus required by plants for growth. I Nutrient budget - A summary of the sources and sinks of nutrients. Nutrient inactivation - Reduction of nutrient's availability for use by I aquatic plants. I Nutrient loading - The addition of nutrients to a waterbody. On-site wastewater disposal - Usually refers to an individual wastewater disposal system such as a septic tank. I Operation and maintenance - Activities required to maintain and operate a project, e.g., electricity, fuel, repairs, etc. needed to run a pump. I PALIS - The computerized data management system used by the Department of Environmental Quality Engineering to store and manage Massachusetts lakes data. I Parameter - A characteristic element. In lake studies it usually refers to chemical components of concern, e.g. phosphorus is a parameter of water i chemistry. Phosphorus - A mineral required by plants for growth. Usually the i limiting nutrient since it is not an abundant element. i Planimeter - An instrument for measuring areas on a map. i I Pcr'nt sources - Individual sources of pollutants such as discharge pipes. Preliminary design - Specification of the main capacities and materials of f a system. Pretreatment - Usually refers to the removal of pollutants before discharge I to a water body or treatment plant. Receiving body - A waterbody receiving discharges of pollutants. I Retention time - The calculated time required for a complete change of water in a lake. i Runoff - Precipitation that flows overland. Sample hold time - The maximum time a sample can be stored prior to i analysis. Sediment core - A sediment sample collected in a cylindrical tube to i represent vertical layers of sediment deposits. Sediment deposit - Accumulated soil and organic material on the bottom of i a waterbody. Sediment depth map - A lake contour map showing sediment depths or the depth of "muck" between the bottom of the water and a solid lake bottom. i Septic system - An on-site wastewater disposal system usually consisting of a septic tank and a drainfield. i " Septic system leachate - Wastewater, from which solids and grease have been removed, that is absorbed by the soil. Silt loading - The addition of fine soil particles to a water body, i usually from erosion. i Socioeconomic - Pertaining to people and the economy. Standard Methods - Specifications by the Environmental Protection Agency i for the analysis of water and wastewater. Storm drainage system - The catchbasins and pipes that collect and convey storm runoff. i Stormdrain - A pipe that conveys stormwater runoff. i Stratification -. The formation of layers :n a lake. Substrate - Usually refers to a growing medium for living organisms, e.g., i substrate for rooted aquatic vegetation. i i I • Subwatersheds - Areas of a watershed that drain to a particular area or point.There are usually several subwatersheds within a watershed. Surficial geology - Unconsolidated geologic deposits resulting from f weathering and glacial action. •' Terrestrial habitat - Land area that supports plant and animal life. Thermal stratification - The formation of distinct layers of water of m different temperatures. Usually occurs in deeper water bodies. Topographic - Pertaining to the shape and height of the land surface. i Tributary - A source of water to a waterbody, such as an inflowing stream, Trophic status - The type or degree of eutrophication. Unconsolidated sediment volume - The volume of sediment prior to dewatering and/or compaction. Water chemistry - Generally refers to the measurement of inorganic i compounds in water samples. i Watershed - The area that drains to a waterbody. Watershed management - Refers to control of nutrients or pollutants prior i to their entering a waterbody. i \ i i i i i i i I I I I I I I I REFERENCES I I I I I 1 I I f I I I- I I REFERENCES I Childs, Ethel B. 1983. History p^f Stow. Stov Historical Society Publishing Company, Stow, Massachusetts. I Commonwealth of Massachusetts, Department of Public Health. 1969. State Sanitary Code, Article VII. Minimum Standard fcir Bathing Beaches. Boston, Massachusetts. I Commonwealth of•Massachusetts, Division of Vater Pollution Control. 1978. Massachusetts Vat'er 'Quality Standards. Boston, Massachusetts. I Commonwealth of Massachusetts, Division of Vater Pollution Control. 1981. Boons Pond Diagnostic/Feasibility Study. Vestborough, Massachusetts. I Commonwealth of Massachusetts, Division of Uater Pollution Control, 1978. Massachuset ts Lake Classification Program. Vestborough, Massachusetts. Dillon, P.J, and F.H. Rigler. 1975. A simple method for predicting the I capacity of a lake for development based on lake trophic status. Journal of the Fisheries Research Board of Canada. No. 31:1519. I Martin, A.C., H.S. Zim, and A.L. Nelson, 1951. American Vildlife and Plants, A Guide _u> Wildlife Food Habits. Dover Publications, Inc. Nev York. I Kaynard Historical Commission. 1971. History o^ Maynard, Massachusetts. Metropolitan Area Planning Council. 1979. A Management Program for Lake Boon: I Interim Report. Metropolitan Area Planning Council, Boston, Massachusetts. Metropolitan Area Planning Council. 1983. Runoff and Recharge. Metropolitan Area Planning Council, Boston, Massachusetts. I Palmer, C.M. 1977. Algae and Vater Pollution. U.S. Environmental Protection Agency. I Soil Conservation Service (1985). Soil Potential Rating for Septic Absorption Fields, Middlesex and Essex Counties, Massachusetts. Littleton, I Massachusetts. United States Environmental Pvotection Agency. 1976. Quality Criteria For I Water. United States Government Printing Office, Washington, D.C. I I I I I I I REFERENCES (Cont.) United States Environmental Protection Agency. 1980. Modeling Phosphorus Loading and Lake Response Under Uncertainty: A Manual and Compilation of I Export Coefficients. United States Government Printing Office, Washington, D.C. EPA 440/5-80-011. I United States Environmental Protection Agency. 1980. Clean Lakes Program Guidance Manual. United States Government Printing Office, Washington, D.C. EPA-440/5-81-003. I Vollenveider, E.A. 1975. Input-output models vith special references to the phosphorus loading concept in limnology. Schueiz. Z. Hydrol. 37:53-62. I Vollenveider, R.A. and J.A. Kerekas. 1980. Background and Summary Results of the Organization for Economic Cooperation and Development Cooperative Program on Eutrophication. United States Environmental Protection Agency, I Washington, D.C. Commonwealth of Massachusetts, Division of Water Pollution Control, 1981a- Eagle Lake Diagnostic/Feasibility Study. Department of I Environmental Quality Engineering, Vestborough, MA. Dunne. T. and L.B. Leopold. (1978). Water in Environmental Planning, W.H. I Freeman and Co., San Francisco- National Oceanic and Atmospheric Administration. 1985, 1986. Climatological I Data, Nev England. Monthly Summaries. National Climatic Data Center, Asheville, NC. m Vandle, S.U., Jr. and R.A. Fontaine, 1984. Gazetteer of Hydrologic ™ Characteristics of Streams in Massachusetts - Herrimack River Basin. United States Geologic Survey, Boston. Water Resources Investigation Report I 84^4234. Vetzel, R.G. 1983. Limnology, Second Edition. Saunders College 1 Publishing, Philadelphia. I I I I I I I •* I M Is •hi K I LJT rv~i /~2 i II UlfcJ i i 4 k i k i SOUTHEASTERN REGJOMAL PLANNING AND ECONOMIC DEVELOPMENT DISTRICT Marion, Massachusetts 02738 .:• k* I I Town Kail Annex Marlon, MP. 02738 I I t I Septic System 1 Maintenance Programs i April 1980 i I I I I The preparation of this report was funded through a grant from I the Environmental Protection Agency. I I I A septic system maintenance program makes sound fiscal sense: It is an inexpensive alternative to expensive I septic system repair or an expanded public sewer system. Homes and other buildings that aren't served by the sewer system must utilize individual septic systems. The State Environmental Code requires that they meet I certain minimum requirements aimed at preventing groundwater contamination and other conditions which I may cause a nuisance or threat to public health. When septic systems are properly operated and maintained; they can provide years of trouble-free service. If ne- glected, however, they are likely to fail sooner, 1 leaving the homeowner with unsanitary overflows and expensive repairs. I A septic system maintenance program would help owners keep their systems in good working condition by regularly I pumping the wastes that can cause systems to fail. (Other conditions may also cause septic system failure. More information is provided in "Septic Systems - How They Work and How to Keep Them Working," prepared by SPREDD and available on request.) A septic system is a two-part sewage treatment and I disposal system composed of a septic tank and leaching field. Sewage generally flows by gravity into the septic tank, prom there, the liquid portion flows into the leaching field. Heavier solid particles settle to the bottom of the tank forming a layer of sludge. Bacteria break- down some of the organic solids into liquias. Altnough this process reduces sludge build-up in.the tank, over time it will accumulate. ™ Pumping a septic system removes this sludge and otner debris from the tank. This is important because these substances can clog the leaching field - and lead to - • septic system failure. A septic system maintenance program is a preventative approach. By pumping sludge before problems arise, i the owner need not worry about sudden septic system I failure caused by sludge back-up. 1 I maintenance programs t;*.G is divided Into four sections: I • The Introduction describes what a maintenance program is and why it's~appropriate to consider adopting I one. • Administrative Authority sets the legal basis for town meeting vote authorizing maintenance programs I and outlines the authority and duties of local boards of health. Since this is a new approach, footnotes show legal sources for further reference. I 6 Elements of Septic System Maintenance Program presents ways of handling records keeping, deter- mining collection routes and methods of treating i the septage that's generated. • The Appendix provides model by-laws for establishing i maintenance programs: - Municipal inspection and maintenance i - Municipal inspection, private maintenance - Private inspection and maintenance Each conmunity is different. The approach most-s.ji ted I for one CDtfrrunity will differ from another's. The by-laws presented are samples to show different k approaches and should be revised to meet local needs. Legal counsel should be sought to ensure consistency i with state laws and local regulations. SRPEDD strongly recommends that any septic system main- tenance program be adopted under a general by-law. This would give the board of health authority to imple- b ment the program in accordance with its duties under state, enabling legislation and Title Five, the Environ- mental Code. The by-law should direct the board of i .health to adopt rules and regulations to implement the program, SRPEDD suggests the sample by-law and regulations in fc Appendix A. Other samples (Appendices B and C) are provided to show the range of options. However, both are based solely on board of health regulations. I I TABLE OF CONTENTS A. INTRODUCTION l" i B. ADMINISTRATIVE AUTHORITY..;.. , 3 1. Statutory Authority of Board of Health 3 2. By-Law Authority of Board of Health 4 i 3. Authority from Rules and Regulations of Board of Hea 1 th 5 i C. ELEMENTS OF SEPTIC SYSTEM MAINTENANCE PROGRAM 6 I 1. Septage Collection 6 2. Septage Disposal 9 4 D. APPEND! CES 13 A. Municipal Inspection and Mainfenance 11 I B. Municipal Inspection, private Maintenance 15 • C. Private Inspection and Maintenance IS i k II k I k k k i ft Tii-rn^n,, (r-T AM I r.. in; i-JwU- I i Jli Homes and other buildings that aren't served by public I sewer systems must use individual septic systems. Title V, the State Environmental Code,- sets minimum standards for their type and capacity. The purpose of Title V is I to prevent groundwater contamination and other conditions causing a nuisance or threat to public health. The local board of health is the enforcement agency of I the Environmental Code. It's their duty to require proper maintenance of septic systems. I Municipalities may adopt a by-law establishing a Septic Systems Maintenance Program, a program of regular septic , tank inspections and pumping as a public service. The program should be administered according to the rules I and regulations of the board of health. A community may adopt one of three kinds of maintenance k programs: - municipal inspection with a publicly-owned pumping k service - municipal inspection with private pumping service - private inspection and privately-owned pumping k service. k The approach best-suited will vary from one coronunity to another depending on local conditions. i Adopting a septic system maintenance program is expected to benefit the public health and welfare and may eliminate the need for future capital expenditures to I extend municipal sewer systems. HGL 21A:13 State Environmental Code "The commissioner I of the- department of environmental quality engineering shall adopt...regulations...including...the disposal of sewage. Local boards of health shall enforce said k code in the same manner in which local health rules and regulations are enforced." Each local board of health is required to enforce the k state code...the primary purpose (of which) "is to prevent violations rather than punish past violations." Comm. v. Haddad 36-1 Mass. 795 (1974) I A town may adopt reasonable regulations relating to cesspools (etc.)...under Section 31 (Chap. Ill) or under Section 127 (Chap. 111). Holden v. Holden Suburban k Supply 343 Mass. 187 I i I- Massachusetts General Laws (Ch. 44:1) define sewage as wastewater from homes, public buildings, commercial or u industrial establishments, or any combination thereof, and includes any surface or groundwater that may be present therein. Sanitary sewage is any water-carried I putrescible waste resulting from the discharge of water closets, laundry tubs, washing machines, sinks, showers, I- dishwashers and other sources, The next sections discuss the board of health's legal authority to initiate a septic system maintenance program according to state enabling legislation, town I meeting approval of a by-law and board of health I- adoption of rules and regulations. I i! t i i i i i i i 1 I , ADMINISTRATIVE AUTHORITY I 1. Statutory Authority of Boards of Health Municipal boards of health are authorized by the I Massachusetts General Laws^ to adopt end enforce reasonable health regulations. Such regulations may. include Droyisi^n^ ±o_jneet the minimum requirements for seotiL system [painj-_pnr.ncp nf the s_taip environ- I mental Code.^ I Title 5 2,33 "Maintenance - Every aimer or agent of premises in which there are any private severs, individual, I sewage disposal systems^ or other means of seuzge disposal shall keep the severs and disposal syst'-'.ts in proper operational condition and shall hav.s_such uorks__cl#aned or rcraired at sush^tine _as_ orderc-d I b_ij th$ Board of Health. If the c;:ner or agent of the pi-sr.rises fails to comply uith such order_, the Board of Health may cause the vorks to be cleaned I or repaired and all erpens^s incurred to be paid by the ouner. S&jase disposal uorks shall be main- tained in a manner 'hat uill not create objection- able conditions or cause the uorks to become a 1 source of pollution to any of the va~ers of the Corvnonusa. I th. " i I NOTE; It is suggested that Section 2,19 be adopted into the rules and regulations of the board of health, by majority vote of the board and publication in i a local newspaper. (See HGL Ch. 111:31.-) _ The board of health has a general statutory authority and (I ' duty to "examine into all nuisances, sources of filth Ml1 andand ratine?causes; ooff ^icknessickness^ within its1; tnwtown,.n .... .whichh r.rr.c.y v. in its opinion, be injurious to the public health (and) I ,_. _ __ 'MGL Ch.* Ill - Section 31 - general regulatory powers -of board of health Section 127 - authority of board of health to adopt and I enforce regulations relative to house drainage. ^ 'Section 127A - enforcement of state environmental code Jl by boards of health. MGL 21A:13 - State Environmental Code - Title 5 - "Minimum Requirements for the Subsurface Disposal of « Sanitary Sewage" II II II i ir._'. i de-'./c/, remove or prever* the ssme ^3 the ';,se may require..." i 2. By-Law Authority of the Board of Health Septic system Inspections and periodic maintenance pumping may be authorized by a municipal by-law as a public service similar- to regular trash and solid waste collection from private property. Adopting such a by-law is authorized by the General The by-law should contain a purpose statement which includes the identification, prevention and removal of public and private nuisances by the board of health, as well as functional public service activities which might be performed by other municipal agencies. Assigning such a charge upon the board of health would support the board's statutory authority as an enforce- ment agency. 6 MGL Ch. Ill - Section 122 - board of health shall examine into, remove or prevent all nuisances. Section 123 - board may order removal of a nuisance Section 130 - maintenance of common nuisance may be enjoined - See Stone v. Heath 179 Mass. 385 •- The decision of the board of health that a nuisance exists establishes that as a fact, the jurisdiction of the board is summary in nature. Sectjoa^l3l..-. board_Jiay_£QX£r_Jnt_o_Jand to examine, rem_oye or prevent a nuisance. 'KGL Ch. 40 - Section 21 - Authority of town to aoopt general by-laws for the purpose of (1) directing and managing the prudential affairs of the town. Prudential Affairs: "Generally relative to power of towns to adopt by-laws regulating and managing in- ternal affairs including "that large class of mis- cellaneous subjects affecting the accommodation and convenience of the inhabitants, which have been placed under 'the municipal jurisdiction of towns by statute ' or by usage" Cox v. Segel 206"Mass. 380 "The town meeting is the legislative' body of the town and it may enact by-laws relating to a wide variety of matters" Op of the Justices 1971 Adv.-Shts 135 MGL 40:5 - Town may appropriate funds for the exercise of corporate powers including performance of the duties of the board of health - (etc.) and in genera-1 "for all other necessary charges" Necessary charges.- "matters where town has a duty to perform, an interest to protect, a right to defend..." Ducey v. Webster 237 Mass. 497 I TI-,O npr^i-o hv_iaw is adopted bv a ma.iority vote of the town meeting. It may provide ror the imposition of a duty upon the board of health, and impose penalties I for violations. Before such by-law takes effect, it must be approved by the attorney general or ninety days shall have elapsed without such approval. Notice by I publication at least two times is required (see Mass. G.L. Ch. 40:31, 32.). I The by-law would: - authorize the establishment of the septic system maintenance service as a municipal function, I - establish improper maintenance as a defined nuisance, - authorize the board of health to adopt and enforce the regulations necessary to carry out the purposes of the by-law, including fees and penalties. There J5 Specific StatUtpfV anthprity fnr mnmV-ip-- to provide and operate facilities tn rprp-iv/p anH dis"p0r2 OT pri vy-Ccsspooi and septic tank conterrs. TnTrrasK could be delegated to the municipal depart- ment of public works and funds appropriated for this purpose by the town meeting. (A suggested by-law is attached in the appendix.) 3. Authority from Rules and Regulations of the Board . of Health The board of health - as the municipal agency charged with enforcing and implementing the septic system maintenance program - should adopt rules and regulations to carry out these duties. Regulations may require revisions from tine to time tc meet special unforeseen or changing conditions. It is suggested that the enabling by-law contain general rather than specific provisions. This would avoid the necessity of special town meetings and attorney general "approval for procedural and administrative concerns which would be covered through board of health regula- tions. (Suggested rules and regulations are attached in me appendix. ) L F! EVENTS OF SEPTIC SYSTEM MAINTENANCE PROGRAM It Is suggested that unsewered portions of town be L divided into maintenance districts of approximately the same number of residences and then further sub- divided to establish inspection.and pumping schedules. L Proper septic system inspection may require complete pumping of the contents in order to determine structural conditions, excessive water flows, and buildup of solid matter. Thus the statutory public health function of the board of health will be combined with the public service pumping fuctions authorized by the local by- law. Central records should be kept on property location cards, rather than by property owners. These cards would show the location of the on-sfte septic disposal system and means of access, street address, lot number, owners name, and pumping and system maintenance infor- mation. (See sample card.) The records cards are designed so that, when folded, the property location information is uppermost for ease of filing and retrieval. The inspector does not remove the record cards from the board of health offices but carries a copy of the card into the field. Maintenance record information, system location information, notes and conments recorded on the field copy by the inspector are later transcribed onto the original cards so that a completed record of all systems is always available in the board of health offices. Septage collected under the maintenance program must be disposed of at an approved treatment and/or disposal facility. A town may appropriate money to exercise its corporate powers, including the performance of statutory and other duties of the board of health. Funds for the main- II tenance program should be included"in the board of health's annuai budget." 1. Septage Collection The basis of the septic system maintenance program is regular pumping and removal of septage, solids and floating scum from cesspools and septic tanks. This task cpuldbe accomplished by town-owned or privately Operated septage pumping and collection vehicles. Pumplhgs tnrougnout tne town would be scheduled so that all individually-owned sewage disposal facilities would be inspected and pumped approximately once every two Location Plan System description Street & Number Owner Assessors plan no. & lot Mair.t. Fecorc da-e comments TOWN OF MARION SEPTIC SYSTEM MAINT Record Card 1 . Location Plan j / /'- i^'-£-ti-.lA.' -^.,1 • -^ — -/^ "w". •' ' ^ 1 ••' ^ . -• C ^-C-r-_ -J~-:^~-''-J ----- • ' J.\\ \\ l._ ^- ^ v- \ v \\ \\\ v \v^ v\^j ' System description 1 • oo" -* ..--. / y . — • • _- ;'" •> - •1 1 1 fj Z .r '• • Street & Number 1• Owner • - .- -' • - Assessors plan no. & lot Maint. Record date comments inspector 1 ',•••--'• r - 1 • 1 TOWN OF MARION SEPTIC SYSTEM MAINT. I ' ' Sample Record Card 1 8 1 II years. The schedule would aiso be organized to allow for additional emergency pumpings - especially during L spring months - and provide flexibility during winter months when frozen ground may prevent opening systems. For municipal programs, the inspector/operator should be ti a town employee trained in septic disposal system con- struction and operation and capable of performing the required inspection and maintenance tasks. He should L also be an appointed health agent. Following collection, septage should be delivered to L' the town operated facilities for treatment and disposal. 2. Septage Disposal^ I An integral part of any septic system maintenance program is developing an economical and environmentally safe disposal process for the septage generated. There I are several treatment and disposal options for septage including: I - sewage treatment plant - septage treatment facility - composting 1 - lagoons All recently built sewage treatment plants^ are designed 1 to accept sepiage, which is aaaed into the wastewater flow. Although septage increases the operational problems and the sludge output of the sewage treatment I plant, it is the preferred treatment method by the state. However, operators are reluctant to accept septage for several reasons: - additional operational problems - additional sludge to process and dispose of I - possibility of getting a load of chemical waste whith could destroy the treatment process. Septane treatment facilities, designed to treat only I septage, produce a treated effluent arid sludge, both of which require an ultimate disposal solution. Usually the sludge is landfilled and the treated effluent is I discharged to water. Septage treatment facilities are expensive to construct, operate and maintain, though I not as expensive as some sewage treatment plants. Composting - a new and as of yet unused treatment and aisposal solution - has been used in other parts of the country. Presently three towns - Swansea, Rehoboth and I Seekonk - are participating in a septage composting project. The full-scale facility is being designed and I when completed should provide valuable information on I . environmentally sound treatment, and disposal scheme I Lagoons, which basically leach the liquid portion of '-* the septage into the ground, are temporary solutions 1 E at best. Few sites will meet DEQE requirements for lagoons due to the pollution potential of this treat- f ment method. Accordingly lagoons should no longer be iTP considered as a septage treatment/disposal option. V The most appropriate septage treatment method will vary '[-* for each community. Some communities without their own lk septage disposal facilities have agreements with neighboring communities for treating septage. Others I may have their own treatment plant or septage treat- ment facility. Septage treatment must be considered an essential element when designing a septic system maintenance program. r- 10 APPENDICES Sample By-Laws for Septic System Maintenance Programs I-' A. Municipal Inspection and Maintenance Inspection, Private Maintenance C. Private Inspection and Maintenance I I d. I te< I i I i it i i i I I A. Municipal Inspection and Maintenance A general by-law, adopted by majority town meeting vote, should contain the following provisions: 5 -1 awv I 1. Authority and direction to the board of implement a program of septic system inspection and maintenance, and a brief purpose statement including I the statutory authority of the board of health under Title Five of the State Environmental Code that septic I systems be kept in proper working order. 2. Provision that failure to maintain a proper, would be deemed a nuisance, and authority of the board of health to make inspections and to require that p/i-.v. I improperly maintained system be cleaned or repaired at the expense of the property owner. ar- j K;:/ I 3. Requirement that the board of health adopt rules and regulations to provide for: I - the issuance of necessary permits - necessary inspections I - maintenance of systems - pumpings and disposal of the contents and - the establishment of reasonable fees to be paid by I by owners of properties included in the program. This approach was prepared by 5RPEDD for the Town of I Marion. I I I t 1 I I 11 i 1 I' On-Site Sewage Disposal Systems 1. For the purpose of ensuring compliance with minimum standards for the health and safety of the inhabitants of the Town of t and to provide for the pumping and disposal of the contents of privies, cesspools and septic tanks as a i public service, it shall be the duty of the Board of Health to examine, remove or prevent nuisances due to improper qn- i site sewage disposal systems, and the Board of Health is directed and authorized to implement a program of septic system inspection and maintenance, and disposal of the contents of such septic systems as an alternative to the system of common sewers and for the protection of surface and groundwater resources of the town from pollution. 2. The Board of Health shall adopt and enforce rules and regula- tions relative to such a program of inspection, maintenance and disposal of the contents of privies, cesspools, and septic tanks within the town, to issue necessary permits, and to establish reasonable fees to defray the costs of such program - such fees to be paid by the owners of properties included in the program. 3. The Board of Health shall have express authority under this by-law to make inspections of on-site sewage disposal systems, failure to maintain a proper system may be deemed a nuisance, and the Board of. Health may require such system to be cleaned or repaired at the expense of the property owner. 12 SOUTHEASTERN REGir ^L PLANNING AND ECONOMIC DEVELOPMENT DISTRICT I _Town Hall Annex N ' Marion, MA 02738 I Suggested Rules and Regulations Board of Health I Septic System Maintenance Program and Disposal of Sewage I Section 1 - Authority 1.1. - These rules and regulations are adopted by the Board of I Health of the Town of { ) acting under the authority of Chapter 111 of the General Laws and Section ____ of the By-Laws of the Town of ( ) for the purposes" of a program of inspection and maintenance of cesspools and I septic tank systems and the collection and disposal of • the contents of such systems. 1 1.2. - To ensure compliance with the requirements of Title Five of the State Environmental Code, every owner, agent or occupant of premises in which there are private sewage disposal systems shall keep such systems in proper opera- I tional order including means of access for inspection and pumping, and shall have such systems cleaned or repaired at such times as ordered by the Board of Health.* (See I page 14.) Failure to comply with such orders, or to maintain such I a system in a manner which will prevent objectionable conditions may be deemed a nuisance injurious to the public health. I 2.0. - Inspection of Premises 2.1.-- For the purpose of determining the proper operation of on- I site sewage disposal systems within the Town of ( ), such systems shall be subject to inspection by'the Board of Health at intervals of not more than two years. I 2.2. - The Board of Health shall maintain a record of each system inspected, including the addres,s of the premises, name and address of the owner/occupant, description, and shall I keep a record of the condition of any system or component thereof on the inspection date. I 2.3. - The Board of Health shall report to the owner/occupant any system found to require improvement, repair, alteration or replacement and may make recommendations as to the I appropriate type and size of system required. I I 13 I I. ing und L-spcsai oi. Contents 3.1. - The contents of on-site sewage disposal systems within I. the Town of ( ) shall be pumped within two years of the effective date of these regulations , and every two years thereafter. Such pumping shall be made by municipal I. employees or private operators duly authorized by the Board of Health. Additional Dumpings may be made as deemed necessary by the I. Board of Health for the proper, operation of a septic tank system. I. 3.2. - Contents pumped from cesspools and septic tank systems shall be discharged at the municipal facilities operated by the Town of ( ) for this purpose. I (NOTE: A town may provide other arrangements by contact with another municipality.) I 3.0. - Enforcement -3.1. - Compliance with Title Five of the Stars Environmental I Code, and with these Rules and Regulations may be enforced by the Board of Health or by its duly authorized agents. I 5.0. - Fees 5.1. - As authorized by Section of the (Town) By-Laws, an annual fee of 5 shall be paid by all owners of I property within the Town of ( ) included in the program of inspection, collection and disposal of contents of septic systems. I Such charge shall constitute a debt due the town upon the rendering of an account thereof to the owner, his authorized I agent, or the occupant. *Titla 5 State Environmental Cede 2.29 Maintenance - Every ouner or agent of previses in uhich there are I any private severs, individual seuage disposal systems, or other means- of seuage disposal shall keep 'the severs and disposal systems in proper operational condition and shall have such works cleaned I CT repaired at such time as ordered by the Board of Health. If the owner or a.^ent of the premises fails to comply vith such order, the Board of Health may cause the i:orks to be cleaned or repaired and i all expenses incurred to be paid by the diner. Sewage disposal ucrks shall be maintained in a manner that u>ill not create objec- tionable conditions or cause the uorks to become a source of i pollution to any of the vaters of the Corrynomjealth. i i I 14 i Dy "* ' •--!• ]': - In this approach, the board of health would inspect ; '-:;r;!v i each septic system at least once every three • •;' years. If the health agent finds the system isn't working ;; i properly, the board would require that it be remedied. Each septic tank would be. pumped at least once every tnrethree years - or more frequentlrreque y if necessary to keep I the system working properly. Licensed septic tank pumpers would be responsible for issuing a receipt to owners showing the name, address i and date of pumping. The owner would sign the receipt. . The pumper would submit a copy to the board of health. These records would be used to show compliance with i the program. The records-keeping may be similar to the one presented previously. A process of a regular inspection program should be developed to keep track of which systems were inspected or pumped and when. (Source of the sample regulation is the Metropolitan i Area Planning Council.) COMMENT: The rules and regulations aaopted by the board of health are based entirely on the authority of Chapter 111 and Title Five of the Environmental Code and i specific reference should be made in a by-law rather than just establishing a septic system maintenance i program through board of health regulations. Without local acceptance of the program by adopting a by-law, the board may find it lacks funds to enforce its regulations because there is no general recognition of I the problem. This method does not provide for a fee system to cover costs. Instead, each individual would i be responsible for paying for pumping. Another option of the municipal inspection, private maintenance approach is used in Manchester, Massachusetts. i The town adopted a free pumping system paid for by the I town, participation in the program is voluntary. i i I § 15 i I I MODEL HEALTH BOARD REGULATIONS FOR TOWN INSPECTION, PRIVATE PUMPING I Section 1. Inspection of Systems f All on-site sewage disposal systems within the Town (City) of shall be inspected by the Board of Health within three years of the effective date of this ordinance and every three years thereafter to determine whether all components of the system f are operating properly and are not malfunctioning. I Section 2. Malfunctioning Systems Any system or component thereof which is found to be malfunctioning or a nuisance to public health, safety and welfare or to the quality i of surface waters or groundwaters shall be ordered remedied in accordance with Title 5 of the State Environmental Code. f Section 3. Septic Tank Pumpino The septic tanks of all on-site sewage disposal systems within the boundaries of the Town (City) of shall be purte: i within three years of the effective aate of this orainance, and ever.- third year thereafter. The Board of Health may require more fre;,u2nt pumpincs of any septic tank wherever it may find such coditional i pumping necessary to the proper operation of the septic tank system. Section 4. Proof of Corneli=nce fi All septic tank pumpers must be licensed in accordance with Title £ of the State Environmental Code. Septic tank pumpers shall issue to owners of the- septic tanks which they pump out a signed receipr. k showing the date of pumping, the name and address of the septic tank owner, and a description of the location and size of the septic t*M:. The owner shall sign the receipt, and the pumper snail submit a copy i to the Board of Health. The receipt shall serve as proof of compli- ance with this Article. i Section 5. * Site Investigation For any system which is serving an existing dwelling or structure and which must be upgraded, altered or replaced, a site investiga- i tion to determine the appropriate type and size of system in & accordance with Title 5 of tne State Environmental Code shall be conducted. k k 16 i L l Section 6. Health Board Report The Board of Health shall prepare a report for each system inspected, including the name and address of the on-site sewage disposal system owner, a description of the location and type of system, and whether I or not the system or any of its components is operating improperly. For any system found to be operating improperly, the report shall also include a copy of the site investigation report as described in I Section 5, t Section 7. Enforcement All violations of municipal and state health regulations and the State Plumbing and Environmental Code discovered during on-site sewage disposal system inspections shall be reported, and appro- I priate corrective and enforcement actions shall be taken by t*-s municipality. In absence of local enforcement, the state Depart^:.-;it. of Environmental Quality Engineering may take any action which the I d of Health is authorised to take. I i I i I I I t I I i 17 i I C. Private^, Inspect ion and Maintenance This approach is based on a septic system maintenance I. permit issued by the board of health. The process would be authorized by majority town meeting or city I council vote. The owner of any building served by a septic system would apply for a permit from the board of health. The application form would include the owner's name and L address and would "indicate that an authorized licensed septic system pumper inspected the septic system. I The form indicates whether the system was pumped or not. If the sludge volume is less than one-third the tank volume, pumping would not be necessary. t (Source of the model regulation is the Office of Local Assistance, Department of Community Affairs.) I COMMENTS: One original septic system permit should be enough. As occupants change, no new permits should 1 be needed. The board of health through its health agent has the • duty to make inspections. This autnority cannot be ™ delegated tc persons v;ho are not aaer.-.s of the board cf heal th . A septic tank pumper's permit does not provide authority to rna!;e d judgement on the conditions of a septic system In fact, the private person who has just been p£ia a fee I to perform a private serv.ee is the wrong person to i make such an inspection. I i i i 18 i MODEL BYLAW FOR PRIVATE INSPECTION AND MAINTENANCE OF ON-SITE SEWAGE DISPOSAL SYSTEMS Section 1. Purpose . .. f It is recognized that proper maintenance of septic tanks will increase ' the useful life of all on-site sewage disposal systems which rely on soil absorption of septic tank effluent. To further the purpose of increased life of such on-site disposal systems and to protect the health, safety and welfare of the inhabitants of the Town (City) of _ , "the Town (City) of _ hereby establishes a septic tank maintenance permit program, Section 2. Permit Required No owner may occupy, rent, lease, live in or reside in, either season- ally or permanently, any building, residence or other structure ser- viced by a private domestic sewage treatment and disposal syster. unless the owner has a valid septic tank maintenance permit for that syste~ I issued in his/her name by the Board of Health. Owner is defined to mean a natural person, corporation, the state or any subdivision thereo: I Section- 3. ' Fee A fee of S_ ashall accompany each application for a septic t tank maintenancee permit.. Section -. Permit Appl i cation Application for a septic tank maintenance permit shall be made to the Building Commissioner on forms supplied at the Town Clerk's office. All applications shall stats the owner's name and address, the address or location of the private sewer system and shell contain the following statement: I certify that, on _ day of _ , 19_ , I inspected the septic tan* located at ,tne address stated on this application* and I (check one"): _ _ pumped all sludge and scum out of the- septic tank, cr _ found that the volume of sludge and scum was less than 1/3 of the tank volume, and I did not pump the septic tank. Signature i Sanitary License Number f f IP '• - l'.' .• -.1. Section b. Usuance The Board of Health shall issue a permit to the applicant upon receipt of the fee and a completed application, properly sig by a person licensed to service septic tanks and stating his sanitary license number. The permit shell "Include on its face all information contained in the application and shall contain the date- of issuance. Section 6. Validity The permit issued under this section shall be valfd for a period cf two yeirs from the date of issuance. Section 7. Sale of Property When property containing a private domestic sev/er systsm is sc"id, i the new property owner, prior to occupying, renting, leasing or residing in th? building, residence or st.ru-ture served by tn; system, shsil r.cl.e a;slir.aticn for and receive a septic tr.ni: maintenance permit, Ko-vever, the syr.tem may oe used for a per ice* i r.ot to exceed 20 dsys after maMng applictfxr, for £ permit. i i i I k k fc I I I I i APPENDIX TO FINAL REPORT ( DIAGNOSTIC STUDY REVISIONS i i Internal Recycling The calculations used for the internal recycling estimate are.listed below. i Note, that this estimate is severely limited in that only one sampling round vas available during summer stratification. Difference in hypolimnetic and epilimnetic phosphorus = 0.03 mg/1 i Volume of hypolimnion » 175.85 acre feet (volume below 5.5 meters) i 0.03 mg 1 g 1 kg 175.85 acre feet 43560 ft2 28.32 1 6.5 kg X X __ X X X - m i 1 1000 mg 1000 g acre ft.yr i Non-Point Source Loading 1. The following coefficients were used in the Lake Boon Study: Non-Point Source Phosphorus Loading Coefficients (kg/ha/yr) Land Use Type Lov Most Likely High Residential 0.35 0.43 0.6 Industrial 1.06 2.67 3.0 Forest/Wetlands 0.1 0.2 0.3 Open Land 0.25 0.8 1.5 Atmospheric 0.3 0.5 , 1.2 2. These coefficents were chosen with two goals in mind. First was to use coefficients which were consistent with the watersheds reported on in EPA (1980a) that had watershed characteristics and localiities which were most similar to those at Lake Boon. The second goal was to choose coefficients which represented the entire range of loading conditions we felt were possible at Lake Boon, and not underestimate the range of phosphorus loading uncertainty. This method of choosing coefficients is as recommended in Chapter 2 of EPA (1980a). As a base for estimation we used "Figure 3A. Box Plots of Phosphorus Export Coefficients from Various Land Uses." This figure presents a statistical summary of coefficents from the literature search conducted in preparation of the publication. We chose the low, most likely and high coefficients based on the 25th percentile, median, and 75th percentile respectively from EPA (1980a), Figure 3a. The coefficients for "forest" were taken directly from this figure. However some land uses at Lake Boon I I I are not adequately described in this Figure. For example a box plot for "urban" land is given. We chose to represent this land use type as "residential" and "industrial" for the Lake Boon Watershed. Therefore, I Table 12 was used to choose coefficients for these more specific categories. In a similar manner, the coefficients for the other land use types were chosen by comparison vith watersheds listed in Tables 6-13 in I EPA (1980a). It must be emphasized that whereas this analysis can be an important planning tool, it should not be used by itself in evaluating lake I restoration, but in conjunction with other methods and indicators. 3. The loading estimates were not broken down into subbasins because of the I similarity in land use patterns around each basin - dense cottage development along the waterfront with forested land further back from the lake. There is no indication from water quality or biological data that loading varies greatly from basin to basin. As noted in the report, the I only difference in land use mapped in the present study compared to the DWPC 1979 estimate was an 8% decrease in forested land. This is due largely to scattered residential development as well as some industrial I development along Main Street and Parmenter Street. Septic System Inputs 1. Ordinarily, soils are very efficient filters for phosphorus from septic systems. However, at Lake Boon many of the septic systems consist of only cesspools, which are quite old and have no septic tanks. Therefore, solids are not removed, except by pumping, and can clog soil pores, reducing filtration. The sandy soils are also poor filters to begin vith, as noted in the discussion on soils. In addition, when many of these systems were installed, they vere only used for a few months of the year because of the seasonal nature of the cottages. Now, most of these cottages have been converted to year round residences with no corresponding upgrade of the sewage disposal systems. When these systems were new they may have filtered 100X of the phosphorus contained in wastewater. At some point in time, each system will approach OK efficiency as it is used over its capacity, soil pores are clogged, and soil adsorption sites become saturated with phosphorus. Based on the above, the 75% phosphorus removal efficiency was estimated for the present, with the knowledge that efficiency of each system is constantly decreasing with time unless a system is rebuilt or replaced. 2. Backup field testing of septic systems was not conducted because of a lack of data to guide selection of test locations. Review of Board of Health records in Hudson and Stow revealed only two documented failures in the last twenty years. Therefore we had no basis on which to choose specific homes for field testing. The evidence at Lake Boon is that the septic I E Pnc systems do not provide adequate filtration of nutrients, not that the septic systmes are failing. No map of severed areas was included because there are none in the watershed. There is no municipal sever at all in Stov. Municipal sewer in Hudson serves the dovntovn area, but is novhere near the Lake Boon watershed. Trophic Status 1. Calculations of "permissible" or "critical" loads of phosphorus was not specified in the scope of vork for this project. Although these vere calculated by DWPC (1981), the calculations were not included in the report so it is impossible to check them to see if they should be revised. 2. The loading figures used in the Dillon and Rigler (1975) model were those derived from the non-point source analysis as described in Table 2-10 and pages 2-61, and 2-62. Vollenveider 1975 model 1. The model chosen is based on refinements to models worked out by Vollenveider in the mid-1960's. This model relates flushing rate, sedimentation, mean depth and in-lake phosphorus concentration to an aerial phosphorus loading rate. This model vas developed in a series of modifications as documented by Vollenweider's publications of the 1960's and 1970's. The original models were developed on a group of Sviss lakes. However, over the years these were expanded in an attempt to identify universal relationships that describe basic processes in lakes. We chose this model for the Lake Boon analysis because (a) data vere available for all input parameters, (b) it is well known and widely used, (c) it is simple to use, and (d) it is based on simple principles that can be easily related from lake to lake. 2. The calculations used in the Vollenweider (1975) modelling are attached. Hydrologic Budget [Note: At this point the DWPC comments change format and are no longer numbered. Our responses are arranged in the same order as the comments in the DWPC letter.I 1. A table is attached which presents the hydrologic budget shown in Table 2-9 in m /sec. This was not included.in the Final Report frankly, because ve are not avare of anyone who uses m /sec. as a standard unit. Our flov rates were expressed in cubic feet per second because the U.S.G.S. (United States Geological Survey), who are responsible for compiling streamflow data in this country, use this unit. Millions of gallons per month (and I I I year) were used for the budget because this unit is commonly used by personnel operating lakes and reservoirs in the United States and is I easily understood by the layman. 2. The "220 days" on page 2-53 is a typographic error - this should read "208 I days". 3. This phrase can be reworded - "....a major component of runoff to Lake Boon is groundwater." I 4. The discussion of groundwater inputs is on page 2-54 not 2-53. The second statement that some groundwater may not enter the lake was not an assumption used in the calculations. It is merely a comment on the I validity of the assumption that all groundwater discharge from the watershed enters the lake. I 5. Table 2-8 was meant to be a summary of key features of the hydrologic budget presented by DVPC (1981). We did not intend to reprint the earlier work as the reader can obtain the earlier work if he is interested. The summary was presented in order to facilitate a comparison between the DWPC I (1981) study and the present study. 6. There is a typographic error on page 2-56 that is probably responsible for the confusion here. The sentence which reads "Measured outflows were 2.25 cfs..." should be "Calculated outflows were 2.25 cfs..." Calculated outflows were obtained in the hydrologic budget presented in Table 2-9. Flows were measured in field with either a pygmy flow meter or a bucket and stopwatch (Table A23). To clarify this difference, the outflows are summarized in the following table: Month Calculated Outflow Measured (instantaneous) Outflow (converted from Table 2-9) (from Table A23) October 1985 2.25 cfs 0.024 cfs April 1986 3.10 cfs 2.20 cfs July 1986 2.35 cfs 1.10 cfs 7. Ve recognized the differences noted between total phosphorus concentrations measured in the present study and by DVPC (1981). The difference is shown graphically in Figure 2-8. The discussion on pages 2-59 and 2-60 includes modelling using both data sets and explores differences in weather which may have influenced the phosphorus concentrations noted. The modelling of trophic status presented in Figure 2-14 is based on non-point source loading coefficients and is therefore not affected by phosphorus values measured in the present study. i E Pnc Ve did not dwell on discussion of White Fond in the Lake Boon report as there appears to be no hydrologic connection betveen White Pond and Lake Boon. Also, ve vere not able to obtain bathymetric data about White Pond so ve don't know if we were at the deep hole when samples were collected, or if there is more than one basin in White Pond. As White Pond is an active water supply for Maynard, and boats are not allowed on the pond, we did not expend a great deal of time on the pond. However, the complete dissolved oxygen-temperature data collected are listed below:. 10/29/85 01/28/86 04/08/86 07/29/86 DO Temp DO Temp DO Temp DO Temp 9.0 13.5 10.3 0.8 10.6 10 8.3 25.5 9.6 3.0 10.6 10 8.2 25.8 10.6 10 8.2 25.8 8.8 4.1 10.6 10 8.2 25.8 10.5 10 8.1 25.8 9.0 13.6 10.6 10 8.6 23.8 7.3 4.2 11.0 9 9.0 23.8 11.0 7.6 7.9 21.2 8.8 13.4 3.8 4.4 Dissolved Oxygen (DO) is in mg/1 Temperature is in C 9. In no way does the watershed to lake ratio imply whether watershed management is warranted or not. This discussion of watershed to lake ratio in the diagnostic section of the report is meant in terras of hydrology and influence on in-lake processes (sedimentation, nutrient-uptake). Obviously, the merit of watershed management is also dependent on cost effectiveness, availability of other management options, etc. - factors which have no part in the diagnostic section. RESPONSES TO COMMENTS OF RICHARD S. MCVOT, SEPTEMBER 30, 1987 Dr. McVoy's comments deal with documentation of calculations and assumptions used in construction of the hydrologic and nutrient budget. Several worksheets are attached which illustrate the calculations used. I I SEPnc I Table 2-9 Lake Boon, Year of Study Hydrologic Budget (cubic meters per second) I Surface Ground- Direct Total Total Runoff vat er Precipitation In Evaporation Outflov Out I 1985 October 0.0049 0.0543 0.0171 0.0764 0.0114 0.0650 0.0764 November 0.1186 0.0543 0.0452 0.2182 0.0059 0.1979 0.2038 I December 0.0452 0.0543 0.0092 0.1088 0 0.1088 0.1088 1986 I January 0.0855 0.0543 0.0255 0.1653 0 0.1653 0.1653 February 0.0536 0.0543 0.0210 0.1290 0 0.1290 0.1290 March 0.1700 0.0543 0.0225 0.2469 0.0033 0.2435 0.2469 April 0.0234 0.0543 0.0086 0.0970 0.0102 0.0868 0.0970 I May 0 0.0543 0.0092 0.0552 0.0174 0.0378 0.0552 June 0 0.0543 0.0588 0.1510 0.0213 0.1297 0.1510 July 0 0.0543 0.0300 0.0944 0.0265 0.0679 0.0944 I August 0 0.0543 0.0150 0.0589 0.0242 0.0347 0.0589 September 0 0.0543 0.0056 0.0190 0.0190 0 0.0190 I*. 0.0417 0.0543 0.0223 0.1183 0.0116 0.1067 0.1183 I I inc 6 Maple Street NorthDorough, MA 01532 393-8558 No Sheet J_ o(_3 Suttject 8y Date. Ckd. Rev._ -C u /;L-h*.UL .- 11. S t k r» - ic?inc.. 6 MJD!« Street Northborough, MA 01532 393-8558 I rii»nt Job No.. of Subject By Date. I A^irWt. Ckd Rev., I (B^/~N I UU 13,*, vjJ&shl. Ovc.- Yk/lo ^ t- u^t- rft-cW^x, "=• a.'itk*-^<- - I I J cJ --9' "• 7-7-7 4r ,3 ^''^;, ^ - - A fA^O^A. I , -tv iEP. , 6 Maple Street I Northborough. MA 01S32 3"~8558 Job No.. of Subject By Date. I Ckd.. I I I I I I P^^rtccg. t^KisJL W*- £v*f>"*4.S<* iX 2.G lAcU /D-v^JL^j1!" r^r T ' i -*-*•»__- | eii«il UAMAt^o-- nh Ho Sheet J-Qt /' Subject 1_ "y Date Tr>pk* AfllL * - t).'i I. JE -jbs- t i Bev. --u* A«. u c/j T U.6-OC-O / c^J 1 1^3. f-xyv^.-.'-^ ft 5T7 33 = ^ U — 2J3 Z. 3 3 <) 4- 0-33 2.0, icP. no 6 Maole Street I Northborough, MA OT532 393-8558 Client Job No. Sheet _L-. I Subject. By Date. I Cktf Re«._ I L *TP I L- 7^°V -^ i TP=: 1A I ,-K ;~ I ^-vT--* I I r I* L . I = 742 c. — (5.3) = 2.-M FEASIBILITY STUDY REVISIONS APPENDIX TO FINAL REPORT FEASIBILITY STUDY REVISIONS 1. Monitoring Program a. Monitoring stations and frequency. The in-lake stations (#1 and the outlet (|5), and the inlets (#3, #4, and #6), are the stations that should be monitored during the implementation and post-implementation period. All parameters listed in Section 3.4.5 except for flow rate and chlorophyll a should be measured at all stations, including top, middle, and bottom stations in-lake during periods of stratification, and top and bottom stations when the lake is not stratified (except fecal and total coliform bacteria which shall only be taken at the surface for in-lake and other stations. Chlorophyll a shall be taken at the in-lake stations only, depth integrated to the depth of light penetration. Flow rate shall be sampled at the inlets and outlets only. As specified in Section 3.4.5, sampling shall occur on a quarterly or seasonal basis for the three year post-implementation period running from March 1990 until October 1992 as listed below for a total of eleven sampling runs: - March, July, and October of 1990 - January, March, July, and October of 1991 - January, March, July, and October of 1992 b. Monitoring costs. See Revised Table 3-4 attached. c. Evaluate Hydroraking/Harvesting Effectiveness. The monitoring program shall also include mapping of aquatic macrophytes in Lake Boon on an annual basis during August of 1990, 1991, and 1992. Mapping shall be done to the same level of detail and scale as described in Section 2.2,4 of the Final Report (page 2-42 through 2-46), including udating of maps shown on Figure 2-11 and 2-11A, and Table 2-6. A description of the differences between original and updated maps shall be included. See also Table 3-4 as revised. 2. Trophic Status The proposed project consists of Option 3 - Weed Harvester Purchase; Watershed Management Plan; and interim contracted Hydroraking. The Watershed Management Plan consists of the implementation of a plan to reduce/control septic system leachate impacts on the lake by; 1) a septic system maintenance program that will encourage frequent pumping by homeowners via a public education program combined with cost discounts for pumping; 2) a requirement in the Town's bylaws that cesspools and other below standard systems be upgraded by the seller upon resale - inspection report would be filed with the Town; and 3) a public education program that will inform residents of the above measures as well as distribute general educational materials on the protection of water quality in the lake and the proper operation and maintenance of septic systems. While we recognize that weed harvesting/hydroraking and septic system maintenance programs are "maintenance options" and will not substantially change the trophic state of the lake, we would also like to respectfully point out that not all situations lend themselves to expensive construction projects that radically change the trophic state of the pond. In the case of Lake Boon, a large sewering and dredging project would indicate significant improvement in the trophic state, but cannot and will not ever be done because of a lack of funds and because of the lack of cost-effectiveness. Further, a sewering project in an area such as this would be very likely to cause serious growth impacts even though it might remove septic system pollutants. Finally, it should also be emphasized that these "maintenance options" will provide improvement in the lake's water quality by 1) reducing septic system leachate impacts on the lake; and 2) by removing macrophyte biomass from the system. 3. Trophic Status See revised Figure 3-1 attached. 4. Public Education Program All options shown in Table 3.3 include a public participation program. The purpose of the table is to compare differences in options. Table 3.4 specifies in footnote 2 that the Watershed Management Plan "...include(s) development of bylaws for cesspool conversion and a public education program (capital cost) and the administration of a septic system pumping program and a continuing public education program (annual cost). It is assumed that these would be conducted together and do not need separate costs. 5. Erosion Control From discussions with IEP, Inc. and our experience at Lake Boon, we do not agree that "...sedimentation is a significant problem at the mouth of some tributaries where silts and sands have accumulated to a depth..." instead, the weedy areas appear to be the greatest problem in areas that were previously wetlands until flooded by the higher dam. Rather than silts and sands as a base, most of these areas are underlain by organic materials — there are no deltas of significance. One resident did point out a couple of eroded areas in private driveways during the study, and recommendations for stabilizing lawns and yards could be a part of the public education program. 6. Impact of Vegetation Removal While clarity does seem to be lower in the lower basins of the lake where aquatic vegetation is least dense, the upper basins have much less populated shorelines and fewer septic systems that might contribute septic system leachate. Sediment sampling indicated that sufficient nutrients exist in sediments to encourage vegetative growth. We feel that it is unlikely that this littoral vegetation removes enough nutrients from septic system leachate to affect algal growth once harvesting/hydroraking begin. 7. Weed Harvesting a. Disposal of cut weed materials is usually very simple according to persons experienced in weed harvesting. The weeds may be composted or otherwise reused as mulch, etc., and should not be disposed where they will drain back into the lake. There are no permits required for weed disposal, and no scope requirement for siting particular disposal areas. b. Costs for disposal are included in overall cost per acre. c. No problems associated with harvesting the types of weeds that appear in the pond are expected. Cabomba and water milfoil are the species of concern since they can spread from fragments, as they apparently did during earlier harvesting attempts. Previous harvesting took place many years ago, however, and the weeds were simply cut without collection. More recently with modern equipment, these species have been harvested successfully elsewhere, and the provision for the collection of cut materials should minimize any problems. Dredging and Weed Screens The Lake Boon Commission specifically requested that the costs be presented in "unit costs" so that they could compare options with similar areal effectiveness. A per acre basis was chosen as the most easily related unit for consideration of diverse options. As described on page 3-13 through 3-15 for dredging, a dredging project for Lake Boon would involve not only the dredging itself but also dewatering, transportation, and disposal. This description then goes into some detail about how such a project might be accomplished at Lake Boon, with estimates of cubic yardage removal from each basin totalling 298,000 cubic yards — or about $15 per cubic yard with near on-site disposal. With offsite disposal and dredging smaller quantities, the total cost per cubic yard would be higher. The $79,000 per acre figure is a unit cost dividing the acres to be dredged in this scenario by the total cost to give the Commission an idea of how the dredging might compare to other options expressed in acre units. For weed screens, vendors estimated costs on a per acre basis, and we do not see. any reason why a per roll plus stakes, etc. cost would be more realistic or easier to deal with. 8. Sewering This statement refers to 1) the fact that putting in sewers does not immediately curtail septic system leachate generation and flow, since it takes years to get all residents hooked up, if they ever are, and the systems will continue to leach anyway for some time; and 2) the fact that one source of phosphorus (septic systems) is generally replaced with another (increased residential densities, housing construction in previously unsuitable areas such as areas with poor soils, high groundwater, and steep slopes). In other words, although you may be able to remove one source of phosphorus, many others will be created as a result of the growth impacts associated with sewering. TABLE 3-4 COST SUMMARY OF PROPOSED PROJECT Lake Boon Diagnostic/Feasibility Study Capital Annual Share Share Component Cost Cost Capital Annual A. Hydroraking $38,000 $9,500(1> (1 year only) B. Watershed Management $30,000 $10,000 $7,500 $10,000 Plan12' C. Weed Harvester Purchase $50,000 $18,000 $12,500 $18,000 and Operation TOTALS $118,000 $28,000 $29,500 $28,000 DWPC 3 year Monitoring Program -1990 $10,000 -1991 $15,000 -1992 $25,000 $50,000 $12,500 $168,000 $42,000 (1) Hydroraking is eligible for funding but is not a prefered use for CWPC Clean Lakes money and generally receives very low priority. (2) Components include development of bylaws for cesspool conversion and a public education program (capital cost) and the administration of a septic system pumping program and a continuing public education program. I 'l I I I I I I ti.OPTIONS 2, 3, 4 I I* II 0.01 1.0 10.0 MEAN DEPTH (m) 100.0 L: AREAL PHOSPHORUS LOADING (fl/m2/yr) R: PHOSPHORUS RETENTION COEFFICIENT T: HYDRAULIC RETENTION TIME (yr) * Condition expected I "Also resents LAKE BOON CAMP DRESSER & DIAGNOSTIC FEASIBILITY STUDY FIGURE 3-1 McKEElNC. TOWNS OF HUDSON AND STOW in association with MASSACHUSETTS IEP, INC, EFFECTS OF FINAL OPTIONS I ON TROPHIC STATUS APPENDIX TO FINAL REPORT LAKE BOON Diagnostic/Feasibility Study TOWNS OF HUDSON AND STOW, MASSACHUSETTS June, 1988 *• I I DIAGNOSTIC STUDY REVISIONS •