Science

ACRWC Rallies to Monitor E.coli

Due to COVID-19 and related factors, Addison County River Watch Collaborative (ACRWC) almost put the lid on all monitoring activities this year. Once Governor Scott “opened the spigot” a bit in June, however, the organization decided to do at least minimal monitoring of E.coli in Lewis Creek, Middlebury River, and the New Haven River. Funding for the planning of this effort came from the Otter Creek Natural Resources Conservation District which has a contract with the Vermont Department of Environmental Conservation to do tactical basin planning work, and funding for the lab work came from towns and private donors.

“Even as we had major concerns about involving our usual thirty or so volunteers in going out in teams to collect water quality samples, we also realized the public wants to have some sense of how the rivers are doing this summer,” said ACRWC managing director Matt Witten. “So, what we did was limit the work to just a handful of people on our board and focus on E.coli sampling at recreational sites.”

Monitoring once per month in July, August and September, the group is sampling for E.coli at six recreational sites around Addison County. The bottles of river water are then driven up to the Endyne lab in Williston. Results are reported from the lab the next day. Then, ACRWC staff Technical Coordinator Monica Przyperhart tabulates the results and sends them out to others to post on Front Porch Forum. Just this week, due to popular demand, River Watch also started monitoring for E.coli at one more recreational site on the New Haven River at DeMers Park.

Przyperhart said, “While it was disappointing to suspend our typical sampling this year, continuing with our E. coli project has provided a thread of continuity. This seems especially important in a year when so many people are looking to our local rivers to provide their summer fun, and health safely is on everyone’s minds. The lull in sampling has also provided an opportunity to focus on other tasks, such as improving our outreach materials and evaluating the benefits of new projects and partnerships.”

E.coli Results
E. coli is a bacteria found in the intestines of humans and other warm-blooded animals. It is used as an indicator of potential fecal contamination of waters. While most strains of E. coli are themselves not pathogenic, detection of E. coli suggests that other disease-causing pathogens may be present. The Vermont Department of Health sets a health-based safety standard for swimming of 235 organisms/100 mL.

Summary of results
E. coli concentrations exceeded health safety standards at the Tyler Bridge on Lewis Creek and at the Shard Villa Road Bridge on the Middlebury River on both sampling days. Concentrations at all other sampling stations were below safety standards. All rivers were at low flow levels at the time of sampling. While rains from an August 4 storm had just begun to fall as samplers filled their containers with water, the rivers had not yet begun to swell, as they did later in the day. ACRWC’s final sample date of the season will be on September 1. For more information, contact Matthew Witten (mwitten@gmavt.net).