MIDDLEBURY — As residents seek respite from scorching summer temperatures at local swimming holes, pesky rumors about water cleanliness — or lack thereof — can inject unease into otherwise bliss-filled afternoons. Talk of waterborne E. coli is particularly quick to cause alarm.
Thanks to the Addison County River Watch Collaborative, though, swimmers wary of foul waters can find monthly updates on E. coli levels in local waters that can help determine which swimming holes are safest.
River Watch’s latest E. coli testing results were made available July 11 and posted on Front Porch Forum. Per the results, one swimming hole on the Middlebury River (at the Middlebury Gorge at the east end of East Middlebury village) and two on the New Haven River (at Sycamore Park and Bartlett’s falls) had E. coli levels far below the maximum for safe swimming.
One location on the Middlebury River, at Shard Villa Road bridge, was deemed a low-level health concern, according to River Watch Managing Director Matt Witten.
Although the results were optimistic, Witten suggested that swimmers still be careful during summer months when high temperatures can lead to increases in the number of bacterial colonies, even in moving water.
“If you compare this to some of the readings we got on some of the other rivers, it’s really not so bad,” he said. “[But] with a summer like this when it’s hot and there’s not much rain … we get higher readings and that mostly has to do with the water getting so warm that it encourages these colonies of bacteria. It’s a good idea to consult River Watch and base your splashing and swimming in water off of that.”
E. coli is a relatively common bacteria found in the intestines and fecal matter of animals and humans, according to the U.S. Centers for Disease Control. Most strains are harmless, but some pose serious health risks. In agriculture-rich Addison County, where bacteria borne by animal feces are washed into moving bodies of water, River Watch checks E. coli levels monthly with the goal of keeping residents informed about swimming safety as well as maintaining ecosystem health.
Hannah Gokaslan, a Middlebury College student working at the college this summer, said that worries about presence of E. coli often creep in when she visits favorite swimming spots, such as the gorge in East Middlebury.
“I get concerned if I accidentally swallow some water while swimming,” she said. “Rumors (about certain swimming holes having E. coli) definitely circulate. Sometimes I’ll get paranoid and convince myself the water isn’t clean even if I don’t really know that that’s the case.”
Jennifer Cyr, director of Jennifer Cyr Family Childcare in Middlebury, said that she recognizes concerns about waterborne bacteria, but tries not to let them prevent her and her children from enjoying the outdoors.
“I think the benefit of time outdoors outweighs the risk of E. coli,” she said. “I can say that because I haven’t dealt with it, but I choose not to let it stop us.”
In evaluating E. coli levels, River Watch measures most probable number (mpn) of E. coli bacterial organisms per 100 ml of water at each of the four popular swimming locations. Per the Vermont Department of Health’s water quality standards, formed in compliance with the Environmental Protection Agency findings, water with an E. coli mpn greater than 235 presents health risks to swimmers. The four swimming holes were scored as follows:
•  Middlebury River at Shard Villa Road bridge: 238 mpn.
•  Middlebury River at Middlebury Gorge: 28 mpn.
•  New Haven River at Sycamore Park: 66 mpn.
•  New Haven River at Bartlett’s Falls: 17 mpn.
According to Witten, local streams and rivers become inundated with E. coli after heavy rainfall, when runoff sweeps animal feces and other vessels for bacteria into streams and rivers. Swimmers should avoid even fast-moving streams right after rainfall, he said.
Witten added that although the recent testing showed that E. coli levels were low across the board, swimmers should be aware of the potential for illness that’s present even when bacteria levels barely exceed the norm, such as at Shard Villa Road.
“At Shard Villa, with the standard being exceeded, that’s like if you were to have a yellow to orange to red warning system, that would be yellow,” he said. “This is probably OK … but it’s probably a good idea to be aware of it and have your kids keep their mouths out of the water and that sort of thing.”