Save The River’s Beach Watch Water Quality program tests the waters of nine popular swimming locations on the Upper St. Lawrence River. Water Quality is determined by the number of E. coli colonies per 100 milliliter (mL) sample. If a sample has a concentration of over 235 colonies or 126 colonies on average over five weeks, it is considered unhealthy by the New York State Health Department.
One of nine samples taken on Monday, July 7, 2025 came back with unsafe levels of E. coli. Sawmill Bay in Cape Vincent had a concentration of 1046.2 E. coli colonies in the 100mL sample. The other eight locations within the acceptable limit of E. coli on July 7 include Wilson’s Beach, Cape Vincent; Potters Beach, Grindstone; Frink Park, Clayton; Bathtub Bay, Picton Island; Round Island, Clayton; the T. I. Park Cove, Wellesley Island; the Lake of the Isles, Wellesley Island; and Scenic View Park, Alexandria Bay.
When a sample fails, the location it came from will close until a resample is taken and passes. River monitors with the Beach Watch program are volunteers who do not have authority to close beaches or swimming areas. The results are used to inform any possible stakeholders of potential health risks associated with water quality and to inform local and state authorities if a location fails.
The presence of E. coli signals that water is likely contaminated with feces, increasing your risk of exposure to pathogens that can cause illness. This risk is particularly high for young children, the elderly, and individuals with compromised immune systems. While common symptoms include gastrointestinal discomfort, skin rashes, and eye and ear infections, some potent strains can lead to severe and even life-threatening complications. Although most illnesses from swimming in contaminated water are mild and don’t require medical aenon, you should consult your physician if your symptoms are severe or persist.
In the interest of public health, Save The River asks residents to be cautious swimming in any location on the River 24 hours after a heavy rainfall event. Studies conducted on nearby urban river environments conclude that due to increased runoff, E. coli levels can become significantly elevated up to six times the normal level after storms with a total precipitation over 2 millimeters. (Urban Impacts on River Shoreline Microbiological Pollution, Dutka & Marsalek, 1993).
For the last 26 years, Save The River has sampled popular swimming locations every week throughout the summer. This year they will test every week from July 7 to August 27. The results of each test are posted on Save The River’s social media, the Save The River storefront located at 409 Riverside Drive, and on the Swim Guide mobile app and website at theswimguide.org.