Bacterial Monitoring Campaign in the Upper Potomac Watershed

Photo by Susan Simonson

Brent Walls, Upper Potomac Riverkeeper, is a real leader in the use of technology to identify pollution problems in his watershed. In 2022, he and his associate, Catherine Gaudlip, technician at Hood College, embarked on a bacterial monitoring program to learn whether local waterways are safe for human contact.

He and Catherine, with the help of about a dozen volunteers, every Wednesday from Memorial Day through September, collected samples from five sites in the Upper Potomac River and four in Antietam Creek.Testing for E. coli, they had good news and bad. Most of the Potomac River sites were within public health standards for E. coli bacteria making these sites great for recreation. While most Antietam sites also had good water quality, at one site on Antietam Creek, the results were consistently over the bacteria limit and at levels that were alarmingly high. These excessive levels prompted a more focused monitoring project for Marsh Run, a tributary of the Antietam Creek.

The Marsh Run monitoring project identified the source of E.coli bacteria as human through DNA testing. The Marsh Run monitoring will continue in 2023 with cooperation from Washington County and Antietam Conococheague Watershed Association to identify funding solutions that address the bacteria pollution. The accompanying graph captures the results for E. coli.

As in the Lower Potomac, the day after collection and analysis, the results were posted on Swim Guide and forwarded to Chesapeake Monitoring Cooperative, which commits to supporting all partners, communities, and individuals who want to collect, share, interpret, and use water quality data to increase the understanding of Chesapeake Bay watershed health and envisions equitable access to water quality data for all communities.

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