Test Results Show ‘Slightly Elevated’ E. Coli Levels in Parts of New Canaan Waterways

A half-dozen bacteria data collection sites in three New Canaan rivers turned up slightly elevated levels of E. coli following tests that commenced this spring, officials said last week. 

The results could indicate nitrogen in the water supply, according to members of the New Canaan Conservation Commission. 

“I am not looking at these streams and rivers as drinking water supply, but I am looking at them from a wildlife and biodiversity standpoint and I am trying to get a better feel on, are they getting too much nitrogen in the water?” Commission Chair Chris Schipper said during the appointed body’s Aug. 13 meeting, held via videoconference. “I assume E. coli is also related to nitrogen. And are there other chemicals getting into the water supply?”

The Commission referred to data collection and water quality tests from Harbor Watch, part of Westport-based nonprofit organization Earthplace. The group presented to the Commission last spring. The town approved a total of $25,000 for the professional services in the Commission’s budget for the current fiscal year.

Expanded Bacteria-Testing of New Canaan’s Rivers Proposed

Test results show that New Canaan’s waterways rank among the cleanest in the region, officials say. At seven E. coli data-testing sites located on New Canaan’s stretches of the Noroton and Rippowam Rivers—sites each tested at least 10 times from May to September last summer—officials found that just one location had a bacteria level that failed state criteria. And that one location—along Ponus Ridge, just below Collins Pond—was only “marginally failing” and within the margin of error, according to marine ecologist Dr. Sarah Crosby, director of Harbor Watch. “I am not overly concerned about there being an acute problem,” Crosby told members of the Conservation Commission during their regular meeting, held April 11 at Town Hall. Asked why New Canaan appears to have cleaner waterways than other towns in Fairfield County, Crosby said “a lot of it has to do with keeping infrastructure up-to-date.”

“A lot has to do with public understanding of things like septic maintenance, and the town regulations around septic systems can have a big impact, and then land use is a big part of it as well,” she said.