CT Water: Reservoir Comes Up Clean In Wake Of Hockanum River Warning

VERNON, CT — Drinking water from the Shenipsit Lake Reservoir has come up clean in the wake of state environmental officials putting out a warning about fish consumption from catches in the Hockanum River.

Shenipsit Lake, the primary reservoir in the region, sits in parts of Tolland, Vernon and Ellington and has a capacity of 5 billion gallons. Lab results from samples collected at the end of last week came in over the weekend and were released Sunday.

"PFAS was not detected in water samples collected from the reservoir or in the treated drinking water leaving the treatment plant," Connecticut Water Co. officials said.

Late Friday afternoon, the Connecticut Department of Public Health and the state Department of Energy and Environmental Protection issued a "consumption advisory" for fish caught in the Hockanum River. The advisory was based on elevated levels of per- and polyfluorinated alkyl substances, or PFAS, in fish tissue samples collected from the Hockanum River in Vernon.

Based on locations identified by the DEEP, health officials are recommending not eating fish from:

• The Hockanum River starting below the Shenipsit Lake dam (Tolland Avenue in Vernon) to the Connecticut River, including the riverine impoundments of Papermill Pond (including Pitney Park, in Vernon)
• Union Pond in Manchester
• Several small impoundments or ponds on the Hockanum River (East Hartford)
• The Tankerhoosen River (from the Hockanum River upstream to the dam at Main Street)

The Hockanum River and its tributaries are located in the towns of Vernon, Manchester, Ellington and East Hartford. The reservoir sits just upstream of the troubled area.

DPH officials said they are working closely with the DEEP, which determined the locations where the fish advisory has been based on their fisheries expertise and knowledge of the case details.

Surface water samples collected with fish tissue in Vernon below Shenipsit Lake met drinking water guidelines, officials said, and therefore the advisory does not apply to Shenipsit Lake, nor does it affect the public drinking water supply, officials said before the latest tests came in.

Connecticut Water officials released a preliminary statement Friday:

"Shenipsit Lake Reservoir is upstream of the Hockanum and is not affected by the “Do Not Eat Fish” order issued by DPH and DEEP. The agencies’ order does not apply to fish in Shenipsit Lake and does not affect the planned opening of the Shenipsit Lake recreation program this Saturday, April 9.

"Connecticut Water tested the water produced by and delivered to customers from the Rockville Drinking Water Treatment Facility for PFAS in 2019 and no detectable levels of PFAS were found. There is robust treatment technology at that facility designed to meet state and federal drinking water quality standards.

"Further, a study of land use in the watershed area of the Shenipsit Lake conducted in 2019 did not identify any land use activities that are typically associated with PFAs. The company owns nearly 1,300 acres of pristine watershed land and conducts regular watershed inspections to protect the drinking water source. However, there have been a number of documented uses along the Hockanum River south of the Shenipsit Lake that could be potential sources of PFAs.

"Out of an abundance of caution, and to give customers additional confidence, Connecticut Water has conducted additional PFAS sampling and testing of the water within Shenipsit Lake Reservoir and from the water delivered from the Rockville treatment facility and results are expected early next week."

State officials said the last drinking water sample collected by Connecticut Water Company showed no PFAS above laboratory limits, officials said. The fish consumption advisory is based on fish tissue results recently received and validated. Fish samples were collected in September 2021 in Vernon, between Route 74 and Dart Hill Road. In total, 30 fish representing three species—American Eel, Fallfish and White Sucker—were analyzed for PFAS concentrations, officials said. Tissue samples showed PFAS at concentrations above levels considered by DPH to be safe for human consumption. PFAS concentrations in White Sucker were somewhat lower than the other species tested, officials said.

The advisory is based on a limited sample size and is issued with an "abundance of caution," officials said.
The Hockanum River statistics were compiled by a consultant retained by the DEEP as part of a large, statewide study to evaluate the presence of PFAS in the state's waste receiving waters.
The study was initiated in response to the Governor's Interagency PFAS Action Plan, which recommended evaluating PFAS levels in fish harvested from Connecticut waters. The study is ongoing, with final results expected by the end of 2022. DEEP officials said the agency plans to conduct additional monitoring along the Hockanum River to better understand the water quality conditions and potential sources of the PFAS.

DPH and DEEP officials emphasized that while fish in the Hockanum River are not safe for consumption, recreational activities such as catch-and-release fishing and boating are safe.

The DEEP stocked the Hockanum River with 2,059 trout earlier this spring (March 4 and 23) before receiving the data showing elevated PFAS levels in river fish in the area.

Long term exposure to PFAS may be associated with increased levels of cholesterol and liver enzymes, a change in immune response, an increased chance of high blood pressure and/or pre-eclampsia during pregnancy, and an increased chance of thyroid disease, developmental defects, and cancer, especially kidney and testicular cancers.