Bayside Beach closed last week for the second time this summer due to high E. coli levels in the water.

The town of Colchester takes water quality samples at 12 locations twice a week on Monday and Wednesday and sends them out for testing. The tests take 24 hours to complete, and the town receives the results the following morning. If E. coli levels are above 235 colony-forming units per 100 milliliters, the town warns the public of the unsafe conditions and retests the water.

“We’re essentially closing the beach out of an abundance of caution for us to get a test that indicates that it’s safe again,” explained Karen Adams, technical services manager of public works. “So we’re actually closing the beach after this issue might have even passed, but it’s the best technology available to us.”

The town has tested water since 1997 as well as researched patterns into when and why high E. coli levels occur. Adams said it’s normal for Colchester to see at least one beach closing per summer.

“We tend to have these elevated readings after when there’s been a period of dry weather that’s followed by rain,” Adams explained. “It’s called the first flush effect.”

Through DNA testing, both human and animal sources of E. coli have been identified in the water samples, Adams said.

“Any amount of human source is unacceptable,” she said, adding the town of Colchester is actively working on addressing the issue.

Human sources of E. coli can be traced back to failing on-site wastewater systems in Malletts Bay residences, public works director Bryan Osborne said. He explained the town conducted a large water quality study several years ago using an Environmental Protection Agency grant, which created a new integrated water resources management plan to address pollution in the bay.

“We did that because we care about Malletts Bay, and intuitively we know that there’s a problem there,” Osborne said. “We felt it was necessary to study that further so that we could be more definitive in exactly what the problem is and to what degree and how best to address it.”

The Malletts Bay sewer project is one of those solutions and has been in the works for several years. If approved, it would bring a municipal sewer system to area residents to replace the failing on-site systems.

Osborne is working to make the project affordable for residents by using grants, loans and possibly local option tax funds while effectively keeping wastewater out of the bay. The project would send Colchester’s wastewater to South Burlington’s treatment plant, he said.

While the sewer project will work on combating human sources of E. coli, Adams said she has been working on several projects to address animal sources of the bacteria in the bay. Currently, Colchester has a simple stormwater system that pipes runoff from roads and surfaces directly into the lake.

“Unfortunately it doesn’t do anything to intercept cigarette butts or dog waste or anything that’s sitting: oils, grease, all of that,” Adams explained. “Part of the projects I’ve been working on are designed to intercept that stormwater and filter it and treat it before it reaches the lake.”

Adams added while nothing can be done about wild animals, people can pick up after their dogs to help combat the issue.

The town has identified over $2 million in stormwater improvements needed in the Lakeshore area alone, Adams said. She added the town just received a $370,000 grant to work on the first of these projects, in the Shore Acres neighborhood.

While Colchester has made progress on dealing with its own water quality issues, some residents wonder whether other communities, like the city of Burlington, might be to blame.

In a July 11 press release, Burlington public works reported 3 million gallons of a fully-treated but non-disinfected mix of stormwater and wastewater was released into Lake Champlain after a heavy thunderstorm overflowed the treatment plant. This was the third dumping in two months at the site.

Adams is not convinced this affected Malletts Bay’s water quality, however, since the bay is geographically isolated from the dumping location, which was a half mile out into the lake.

“Every community in Vermont is dealing with these water quality challenges,” Adams said. “It would be a lot easier for staff like myself if there were a silver bullet that we could point our fingers at and say it’s their responsibility to fix the problem … it’s just not that simple.”