The 2017 West Hill Pond Report

Published in Spring of the year following the testing (year 2017) this report provides insights into the health of West Hill Pond and its watershed.

2017 Report on West Hill Pond [Report Size 3.3mb]

Recommendations

The overall water quality of West Hill Pond is excellent, but there are definite steps that residents and the Association can take to ensure that the lake is well managed. The lake is hovering on the higher side of its Oligotrophic classification, and if no efforts are put in place to maintain good water quality and low nutrient levels, then the lake’s overall health will slip into a less desirable Mesotrophic range, based on the CT Water Quality Standards.
Steps to Maintain Excellent Water Quality

1. Annual aquatic plant surveys to scan for a possible new infestation of invasive species, and to track plant cover such as the expansion of Large-leaf pondweed and filamentous algae.


2. Create a volunteer network for monitoring incoming boats at the State boat-ramp.


3. Volunteer sampling to be conducted at least monthly from April to November.


4. Follow-up with septic system inspections and entertain a mandatory septic pump-out requirement for homes within the watershed, specifically within 200-ft of the shoreline. Focus on Priority Areas outlined from “Dry” seepage sampling survey.


5. In areas of high stormwater nutrient concentrations identified by the “Wet” seepage survey, obtain records of Town-owned right of ways to explore potential stormwater management and infiltration systems. Maintenance to private and Town roads should have oversight from both the West Hill Pond Association and NEAR.


6. Monitor potential increases in anoxic boundary and internal loading. April and November sampling is critical to tracking long-term impacts of internal loading.


7. Beach maintenance should be included in the lake monitoring and management plan. The Town should use a silt fence to protect the beach from winter erosion.


8. All Town Inland Wetlands Commissioners should be educated on basic nutrient management and shoreline buffer zone practices.


9. The Association must follow up with the CT DEEP in regards to their fisheries management at the lake, specifically about their Smelt rearing program that may negatively impact fragile zooplankton populations and overall water clarity.

Water Quality Standards

Drawing attention to the comments on page 5 of the report … West Hill is currently classified as an Oligotrophic Lake … an important designation attained by very few lakes in the state in 2017. This rating is in jeopardy by the trends noted below.

The State of Connecticut Water Quality Standards (WQS) Section 22a-426-6 (a) define the “Lake Trophic Categories” based on ranges of Total Phosphorus, Total Nitrogen, Chlorophyll-a, and Secchi disk transparency, and/or (b) the percentage of the lake’s surface area covered by aquatic plants. The Connecticut Department of Energy and Environmental Protection (DEEP) uses these standards, as displayed in Table 1, to assess the quality of the state’s lakes and ponds. Based on these criteria, West Hill Pond is classified as oligotrophic, or low in nutrients and with very clear water. However, the 2015-2017 water quality sampling reveals that West Hill Pond’s spring and summer surface Total Phosphorus numbers range from 5-14 μg/L . Similarly, the spring and summer sampling from 2002-2017 revealed that 24% (6 of 25 total) 1-meter phosphorus measurements were >10 μg/L , indicating that the lake is hovering within the oligo-mesotrophic range in terms of surface phosphorus levels.

Based on the CT WQS (Table 1), the Total Nitrogen and Secchi disk transparency measurements of West Hill Pond also meet oligotrophic conditions. Yet similar to the Total Phosphorus fluctuations, testing results shown that there are some spring and summer months where nitrogen slightly exceeds the 200 μg/L defining range, and where Secchi clarity periodically falls below 6-meters.