‘Higher than acceptable’ levels of bacteria in greater New Haven area rivers



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Recent river testing revealed higher than acceptable levels of bacteria, and a dramatic contrast between test results from samples taken on dry and rainy days.

River Advocates of South Central Connecticut conducted two days of bacteria testing along the lower Quinnipiac River, West River and Mill River.

The monitoring efforts can indicate whether sections of the rivers are impaired for recreational use, including swimming. Urban rivers in south central Connecticut have been listed as impaired for recreation and aquatic life, according to a 2020 integrated water quality report from the state Department of Energy and Environmental Protection.

State Rep. Mary Mushinsky, River Advocates executive director, and a group of testing volunteers presented the findings Wednesday at Wharton Brook State Park on the North Haven-Wallingford line. 

The bacteria are indicators of the presence of untreated human or animal sewage, but are not dangerous in themselves, said Mushinsky, who represents Wallingford.

Testing took place Sept. 8, a dry day without previous rainfall, and Sept. 24, after more than an inch of rainfall — urbanized rivers often show different results on dry versus wet days, according to a statement from River Advocates.

Trained volunteers collected river and stream samples at 20 monitoring sites in Wallingford, Cheshire, North Haven, Hamden and New Haven, spanning three watersheds that end in New Haven Harbor and Long Island Sound.

Regional Water Authority labs in New Haven analyzed the freshwater samples for contamination indicator bacteria Escherichia coli, or E. coli.

Environmental Monitoring Laboratory of Wallingford analyzed the brackish — mixed seawater and freshwater — samples collected near the harbor for the bacteria enterococcus.

The volunteers used a grip pole and sterile bottles to collect the samples, kept the samples chilled in a cooler and brought them to the labs within six hours — early enough in the day that lab scientists could grow and analyze the bacteria.

On Sept. 8, the dry day, streams and rivers were found in “surprisingly good condition,” according to the statement, and met the standards for designated swimming areas. The West River and lower Quinnipiac River and their streams were suitable for public recreation, however the brackish sites in New Haven failed.

“The likely reason is the continued use of combined sewer overflow systems in older cities like New Haven,” according to the statement. “Sewage and storm water share the same pipes under the city. They are slowly being separated, but the expense means the timetable is slow.”

Bacteria limits of E. coli in water for recreational uses is less than 1 colony forming unit (CFU) per 100 milliliters (ml), less than 235 CFU per 100 ml, less than 410 CFU in non-designated swimming areas and less than 576 CFU for all other recreation except swimming.

Bacteria limits of enterococcus in water for swimming is less than 104 CFU.

On Sept. 24, the rainy day, only a single location in Hamden met the standards for a non-designated swimming area. All other sites showed “massive and widespread failure” to meet recreational standards. In fact, the bacteria counts exceeded the mathematical limit of the test.

“Rainfall carries human and animal waste into the area’s rivers and streams because the landscape has been changed from forest and soil to extensive pavement and piping,” according to the statement. “Our area rivers are unsafe on rainy days for contact recreation and are therefore still impaired.”

The Community Foundation for Greater New Haven’s Quinnipiac Fund and the Greater New Haven Green Fund supported the monitoring project.

Testing sites in Wallingford along the Quinnipiac River included the Fireworks Island canoe launch at Quinnipiac River Linear Trail, the Harry O. Haakonsen Fishway on River Road, Wharton Brook at Doolittle Park and Allen Brook at the intersection of Northfield and Pond Hill roads.

Testing sites in North Haven along the Quinnipiac River included Pine Brook, near 59 Todd Drive South off Hartford Turnpike, the Muddy River, off Route 103, and the Sackett Point Road boat launch.

Testing sites in Cheshire along the Mill River included Willow Brook, at Cornwall Avenue along the Cheshire-Farmington Canal Heritage Trail, and 257 Fenn Road.

Jeff Nelson, Cheshire Land Trust board member who volunteered to monitor the Mill River, said Wednesday that the group had known about the water pollution from human and animal waste, but he’s concerned with other factors, like chemical runoff from residential fertilizers.

“There are a lot of yards that have no riparian barrier, which is that wild growth between your lawn and the riverbed that is ideally 30 feet,” Nelson said. “That affects the fisheries down below, and what the Water Authority has to treat … Like a lot of areas with lead pipes in places, it’s expensive to change and existing structures.”

Meriden flooding

In Meriden, floodwaters from the heavy rains of Tropical Storm Elsa on July 9 submerged blocks-long sections of Hanover Street, Cook Avenue, Pratt Street and State Street in up to 2 ½ feet of water.

Ten days later, city officials reported an estimated 1.37 million gallons of combined rain and untreated wastewater was discharged into the Quinnipiac River as a result of the heavy rainfall during the storm, spilled from the city’s sewer treatment plant on Evansville Avenue.

Officials did not report water contamination or elevated bacteria levels as a result of the event.

In North Haven, DEEP closed the swimming area at Wharton Brook in August due to high bacteria counts in August.

LTakores@record-journal.com203-317-2212Twitter: @LCTakores



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