I c I I I I I I I I I I I I I I I I BAYSTATE ENVIRONMENTAL CONSULTANTS I N: I DRAFT FINAL REPORT I I I DIAGNOSTIC/FEASIBILITY STUDY FOR THE MANAGEMENT OF I LOST LAKE / KNOPF'S POND I PREPARED FOR THE I TOWN OF GROTON AND THE I MASSACHUSETTS DIVISION OF WATER POLLUTION CONTROL I UNDER MGL CHAP. 628 I MASSACHUSETTS CLEAN LAKES PROGRAM I I BAYSTATE ENVIRONMENTAL CONSULTANTS, INC I 296 NORTH MAIN STREET I EAST LONGMEADOW, MASSACHUSETTS I I DRAFT REPORT I APRIL 1989 I I I I I PROJECT SUMMARY I Lost Lake / Knopp's Pond and its watershed was the subject of a Phase I Diagnostic/Feasibility Study, conducted under the M.G.L. Chapter 628 Clean Lakes Program. This study was performed I by the firm of Baystate Environmental Consultants, Inc. for the Town of Groton. The Diagnostic/Feasibility study's primary goals were to determine the historic and present water quality conditions in the lake, identify the major sources of nutrient I loadings in the watershed and provide appropriate recommendations for improvement of the water resource. The major problems of concern were decreasing water quality and recreational impairment I caused by dense beds of aquatic macrophytes. The period of sampling and data collection was from October 1987 to September I 1988. The results of the Diagnostic portion of the study indicated that Lost Lake / Knopp's Pond is a mesotrophic lake verging on eutrophic status, which is impacted by its increasing I residential watershed. Phosphorus was the most important limiting nutrient for primary production in Lost Lake / Knopp's Pond. Phosphorus was found to be entering f rom ^a-1-^ a number of I sources^x^ The three most important being Martin' sTond Brook (46%), groundwater (24%) and and unnamed tributary (17%). The biological community which exists under these conditions contains a diverse but overabundant macrophyte population and an average I to fair fish community, overpopulated by panfish. /• - Feasibility portion of the studv^onsidered and I eliminated lake management options not appropriate or feasible for Lost Lake / Knopp's Pond. The recommended options were construction of a pond underdrain to allow controlled drawdowns I for macrophyte control, application of benthic (bottom) barriers to provide localized relief from macrophytes at the town beach and private residences and a comprehensive education program on watershed management. This education program stresses I improvement of surface water quality through adoption of best management practices and improvement of local residents' environmental awareness. Protection of groundwater through I enforcement of local ordinances and increased maintenance and pumping of abutter' s septic systems are also included. Implementation of all the management options would reduce the I phosphorus budge^fby 19 to 29%. A detailed description and cost estimate for each recommended alternative is provided. Costs of the recommended management options total to approximately $185,000 with local support (Groton) of about $60,000. I majority of the funds are being sought from the MA Clean-^Lakes I Program. I I I I TABLE OF CONTENTS I PAGE I PART I. DIAGNOSTIC EVALUATION 1 Introduction 3 I Data Collection Methods 5 Lake and Watershed Description and History 9 Lake Description 9 I Watershed Description 13 Watershed Geology and Soils - -16 I Historical Lake and Land Use 20 Limnological Data Base 25 Flow and Water Chemistry 25 Supplemental Water Quality Sampling 45 I Tributary Sampling 45 Littoral Interstitial Porewater Sampling 50 Well Sampling 50 I Bacteria 53 Phytoplankton 56 Macrophytes 61 ZooplanKton 67 I Macroinvertebrates 67 Fish 71 Sediment Analysis 72 I Comparison with Other Studies 76 Questionnaire Survey 87 I Hydrologic Budget 93 Nutrient Budget 107 Phosphorus 107 I Nitrogen 117 I Diagnostic Summary 119 I PART II. FEASIBILITY ASSESSMENT 121 Evaluation of Management Options 123 Available Techniques 123 I Evaluation of Viable Techniques 128 I I I iii I PAGE I Water Level Control 133 Elements of a Drawdown Program 133 • Installation of a Pond Drain 135 I Installation of a Permanent Siphon 138 Installation of a Temporary Siphon 145 Anticipated Impacts of a Drawdown 148 I Costs, Permits and Summary 152 • Macrophyte Bottom Barriers 153 • Elements of Program 153 | Anticipated Impact of Improvements on Lost Lake / Knopp's Pond 155 . Costs, Permits and Summary 155 I Watershed Management - Improving Surface Water Quality 159 Elements of Program 159 I Land Use Controls 159 I Adoption of Best Management Practices " 165 Residents' Environmental Practices 167 • Anticipated Impact of Program 171 • Costs, Permits and Summary 171 Watershed Management - Groundwater Protection and I Management 173 • Elements of Program 173 Land Use Controls 175 • On-site Wastewater Disposal Systems 177 | Alternative Technologies for Septic Systems 178 Mitigation of Impacts by Existing Septic Systems 180 H Anticipated Impact of the Groundwater Protection and I Management " 183 * Costs, Permits and Summary 183 Recommended Management Approach 185 I Discussion of Recommended Options . 186 Anticipated Impacts of Proposed Management Actions 187 • Monitoring Program 189 I Funding Alternatives 193 Contact Agencies 195 Environmental Evaluation 199 Environmental Notification Form 199 i Comments by Interested Parties 199 Relation to Existing Plans and Projects 199 • Feasibility Summary 201 References 205 i i i 1 1 PAGE APPENDICES : 1 Appendix A - Educational Information About Land and Wastewater Management for Minimization of Ground Water Pollution 1 and Best Management Practices Appendix B - Environmental Notification Form i Appendix C - Comments by Interested Parties and Sample Survey Questionnaire Appendix D - Data and Calculations i• - 1. Water Quality Data 2. Biological Data 3. Calculation Sheets and Useful i Conversions i Appendix E - General Aquatic Glossary i i i ~ i • i i i i i i i - -: 1 1 LIST OF TABLES 1 PAGE Table 1 Characteristics of Lost Lake / Knopp's Pond and Watershed 10 Table 2 Values of Monitored Parameters in the Lost Lake / Knopp's 1 Pond System 26 Table 3 Tributary Water Quality Data in the Lost Lake / Knopp's 1 Pond System 48 Table 4 Lost Lake / Knopp's Pond Porewater Quality Data 52 1M Table 5 Well Water Quality Data in the Lost Lake / Knopp's Pond Watershed 55 I Table 6 List of Aquatic Macrophytes in Lost Lake / Knopp's Pond 66 I Table 7 EEC Fishery Survey Results 74 Table 8 Lost Lake / Knopp's Pond Sediment Calculations 80 I Table 9 Chemical Characteristics of Lost Lake / Knopp's Pond Sediment 81 Table 10 Historic Water Quality Data from the Lost Lake / Knopp's I Pond System. 84 Table 11 Summary of Questionnaire Responses for the Lost Lake / Knopp's Pond Study Area 88 I Table 12 Precipitation Data for the Groton, Mass. Area 96 I Table 13 Hydrologic Budget for Lost Lake / Knopp's Pond 104 Table 14 Nutrient Export Coefficients 109 I Table 15 Nutrient Load Generation 110 Table 16 Equations and Variables for Load Derivation 111 I Table 17 Phosphorus Load to Lost Lake / Knopp's Pond Based on Models 112 Table 18 Phosphorus and Nitrogen Mass Flows in the Lost Lake / I Knopp's Pond System 114 Table 19 Nutrient Loads to Lost Lake / Knopp' s Pond Based on I Empirical Data 116 I Table 20 Lake Restoration and Management Options 124 I I Vll I PAGE I Table 21 Sequence of Construction Activities Associated with the Installation of a Bottom Drain at Lost Lake / Knopp's Pond 139 I Table 22 Costs Associated with Installation of Pond Drain 141 Table 23 Sequence of Construction Activities Associated with the i Installation of a Permanent Siphon at Lost Lake / Knopp's Pond 144 I Table 24 Costs Associated with Installation of Permanent Siphon 146 Table 25 Zoning and Developmental Options 160 i Table 26 Best Management Practices Categories 166 Table 27 Typical Alternative Equipment and Technologies for On-site i Wastewater Management. 179 Table 28 Anticipated Impacts of Proposed Management Actions on the Phosphorus Budget for Lost Lake / Knopp's Pond 188 i Table 29 Costs of Three Year Monitoring Program Associated with Management Options 190 i Table 30 Local Costs of Recommended Management Options 194 i Table 31 Potential Funding Sources for the Proposed Restoration of Lost Lake / Knopp's Pond 196 Table 32 Permits and Approvals 202 i Table 33 Summary of Management Actions, Implementation Schedule and Associated Costs 203 i i i i i i i V1X1 i 1 LIST OF FIGURES 1 PAGE Figure 1 Location of Sampling Stations at Lost Lake / Knopp's Pond, 1 Groton, Mass. 6 Figure 2 Bathymetric Map of Lost Lake / Knopp's Pond 11 1 Figure 3 Hypsographic Curve of Lost Lake / Knopp's Pond 12 Figure 4 Lost Lake / Knopp's Pond Watershed (with, sub-drainage 1 basins) 14 Figure 5 General Features of the Lost Lake / Knopp's Pond Watershed 15 1 Figure 6 Land Use Classification in the Lost Lake / Knopp's Pond Watershed 17 1 Figure 7 Soil Type Classifications in the Lost Lake / Knopp's Pond Watershed 18 1 Figure 8 Temperature and Dissolved Oxygen Depth Profiles; 1987-88. 31 Figure 9 Tributary Sampling Sites in the Lost Lake / Knopp's Pond 1 Watershed 46 1 Figure 10 Locations of LIP Sampling Sites in Lost Lake / Knopp's Pond 51 Figure 11 Well Sampling Sites in the Lost Lake / Knopp's Pond Watershed 54 1 Figure 12 Lost Lake / Knopp's Pond Phytoplankton - Cell Numbers and Cell Volumes 55 1 Figure 13 Typical Vegetative Transects in Lost Lake / Knopp' s Pond 62 Figure 14 Distribution of Aquatic Macrophytes in Lost Lake / 1 Knopp's Pond 63 Figure 15 Benthic Cover by Aquatic Macrophytes in Lost Lake / 1 Knopp's Pond 68 Figure 16 Zooplankton Size Distribution