Long Term Data Analysis and Management of Lake Pocotopaug
Beginning in 2014, our firm was selected to perform an intensive review of various lake nitrogen and phosphorus loading models. As part of this project, we were responsible for analyzing a long term water quality data set, as well as collecting current monitoring data. Lake Pocotopaug was plagued by persistent seasonal cyanobacteria blooms despite two Alum treatments performed in 2000-2001. Our research evaluated the increase in volume and seasonal persistence of anoxic water over time, as well as an incremental increase in watershed development. Statistical analysis revealed that cyanobacteria blooms are stimulated by phosphorus and nitrogen derived from a combination of internal sediment loading and external stormwater inputs. Hydrologic data also indicates that cyanobacteria blooms coincide with lake stagnation and severely reduced summer flushing. Since 2014, we have continued to monitor the lake at least monthly from April through October, all while guiding Town personnel and lake residents through the uphill battle of watershed protection, stormwater improvements, and water quality improvement. We successfully prepared an EPA-approved Nine Elements Watershed-Based Lake Management Plan in 2016 and have since overseen a number of Low Impact Development (LID) stormwater retrofits in the Pocotopaug watershed. Since 2014, our role has been to increase communication between Town departments and to guide watershed improvement projects funded in part by the Clean Water Act Section 319 Nonpoint Source Pollution Grant Program.
Internal Loading & Cyanobacteria Bloom Mitigation at Bolton Lake
Our firm was called upon to evaluate the causes of a cyanobacteria bloom at Lower Bolton Lake in eastern Connecticut. Our work compelled the CT DEEP/DPH to publish guidance on harmful cyanobacteria blooms in recreational waters in 2013. Since that time, we have continued to work with the Towns of Bolton, Vernon, and Coventry, as well as the CT DEEP and multiple homeowner associations to ensure good water quality. We are also responsible for ongoing aquatic plant management at all three of the Upper, Middle, and Lower Bolton Lakes chain. Our most recent work, has involved on going watershed stormwater monitoring aimed at reducing erosion and nutrient loading to the lakes. In recent years, we have conducted multiple resident monitoring training sessions to allow local stakeholders to participate in the ongoing data collection process. We work closely with the Friends of Bolton Lakes, who cares deeply about water quality preservation and prevention of new invasive species.
West Hill Pond Seepage Survey & Lake Management
From 2015-2018, NEAR conducted a detailed analysis of historic and updated water quality data for West Hill Pond (261-acres) in New Hartford, CT. Sampling included monthly water quality sampling from two lake stations, all tributaries, and the outlet dam culverts. NEAR exampled the results of two stormwater sampling events and also conducted two extensive lakeshore seepage surveys, during both “Dry” and “Storm” conditions. The perimeter seepage surveys were organized to coincide with a required 6ft drawdown in order to repair the lake’s dam. During this survey, NEAR identified locations of groundwater inputs and septic system impairment. This data was used to create a long-term monitoring and management plan for West Hill Pond, which is the last publicly accessible oligotrophic lake in the state of CT. NEAR continues to work for the West Hill Pond Association and has since helped them establish a resident monthly water quality monitoring program. All data was compiled into various nutrient loading models including LLRM.
Long Term Data Collection and Management of Lake Oscawana
The Town of Putnam Valley (NY) has employed our firm since the early 2000’s to collect ongoing water quality data and to assess the efforts to control invasive aquatic Eurasian milfoil. Beginning in 2016, we increased our tributary monitoring to begin to pinpoint areas within the watershed that may have outdated or improperly functioning onsite wastewater treatment systems. New research and data interpretation has lead to Town septic system pump-out ordinances and many complete rebuilds of failing systems. As recently as 2019, our firm has coordinated and published an updated Lake Management Plan, which includes both in-lake and watershed nutrient management to prevent cyanobacteria blooms, as well as custom tailored aquatic plant management recommendations.