INVESTIGATION OF ALGAL BLOOMS AND POSSIBLE CONTROLS FOR CLIFF POND, NICKERSON STATE PARK, BREWSTER, MASSACHUSETTS BY WATER RESOURCE SERVICES, INC. JUNE 2014 IN COOPERATION WITH AQUATIC CONTROL TECHNOLOGY Contents Executive Summary ....................................................................................................................................... 1 Project Background and Need ...................................................................................................................... 3 Cliff Pond Features .................................................................................................................................... 3 Watershed Features .................................................................................................................................. 7 Designated Uses ........................................................................................................................................ 9 Rehabilitation Needs and Objectives ........................................................................................................ 9 Additional Data Needs ............................................................................................................................ 10 Study Approach and Methods .................................................................................................................... 10 Historic Data Review ............................................................................................................................... 10 Watershed Assessment........................................................................................................................... 10 In-Lake Investigations ............................................................................................................................. 11 Water Quality ...................................................................................................................................... 11 Sediment Assessment ......................................................................................................................... 11 Seepage Assessment ........................................................................................................................... 14 Water Depth Assessment ................................................................................................................... 16 Biological Assessments ....................................................................................................................... 16 Investigative Results ................................................................................................................................... 18 Historic Data Review ............................................................................................................................... 18 Watershed Assessment........................................................................................................................... 23 In-Lake Investigations ............................................................................................................................. 25 Bathymetric Assessment ..................................................................................................................... 25 Water Quality Data ............................................................................................................................. 25 Seepage Quantity Assessment ............................................................................................................ 35 Seepage Quality Assessment .............................................................................................................. 36 Sediment Distribution Assessment ..................................................................................................... 38 Sediment Quality Assessment............................................................................................................. 38 Aluminum Dose Testing ...................................................................................................................... 41 Plankton Analysis ................................................................................................................................ 42 Macrophyte and Mussel Analysis ....................................................................................................... 45 Fishery Assessment ............................................................................................................................. 45 Data Analysis and Interpretation ................................................................................................................ 48 Oxygen Demand ...................................................................................................................................... 48 Hydrologic Loading.................................................................................................................................. 50 Nutrient Loading ..................................................................................................................................... 52 Biological Status ...................................................................................................................................... 54 Diagnostic Conclusions ............................................................................................................................... 56 Management Options ................................................................................................................................. 60 Overview ................................................................................................................................................. 60 Oxygenation ............................................................................................................................................ 79 Phosphorus Inactivation ......................................................................................................................... 83 Conclusions and Recommendations ........................................................................................................... 84 References .................................................................................................................................................. 86 APPENDIX A. Monitoring Data for Cliff Pond .............................................................................................. 89 APPENDIX B: Calculations and Analyses ................................................................................................... 108 Tables Table 1. Locations of wastewater disposal facilities near Cliff Pond. .............................................................. 25 Table 2. Seepage measurements for Cliff Pond in 2013 ........................................................................................ 36 Table 3. Seepage quantity and quality for delineated shoreline segments ................................................... 37 Table 4. Results of sediment quality testing and aluminum dosing assays................................................... 40 Table 5. Fish captured by gear type in Cliff Pond, August 21, 2013 ................................................................. 46 Table 6. Average and range of length for fish captured in Cliff Pond, August 21, 2013 ........................... 47 Table 7. Oxygen demand in Cliff Pond .......................................................................................................................... 49 Table 8. Hydrologic load to Cliff Pond ........................................................................................................................... 51 Table 9. Nutrient loads to Cliff Pond .............................................................................................................................. 53 Table 10. Algae management options review ........................................................................................................... 61 Figures Figure 1. Cliff Pond and Nickerson State Park location on Cape Cod ................................................................. 4 Figure 2. Cliff Pond immediate area ................................................................................................................................. 5 Figure 3. Bathymetric map of Cliff Pond ........................................................................................................................ 6 Figure 4. Ground water contours on east Cape Cod (Cliff Pond shown as red square).............................. 7 Figure 5. Ground water contours and drainage boundary and surface water drainage boundary ...... 8 Figure 6. Erosion on slopes around Cliff Pond in 2013 ........................................................................................... 9 Figure 7. Map of water quality sampling stations .................................................................................................... 12 Figure 8. Map of sediment sampling stations ............................................................................................................ 13 Figure 9. Map of seepage stations ................................................................................................................................... 14 Figure 10. Map of littoral interstitial porewater sampling stations ................................................................