Greenfield, MA – As we enter the heat of the summer season, one of the most asked questions the Connecticut River Conservancy (CRC) gets is if rivers are clean enough for swimming, boating, and other recreation. There are two ways to know if rivers are likely clean. The first is to think about the recent weather. Rain picks up all sorts of pollutants as it flows across roads and parking lots, which are then flushed into rivers via storm drains. Additionally, heavy rain overwhelms our aging sewer and stormwater infrastructure, causing sewage and polluted stormwater to flow directly into rivers rather than back up into homes. For these reasons, CRC recommends river users stay out of the river for 24 to 48 hours after a heavy rain because bacteria levels could be high.

“It’s difficult to reduce stormwater runoff from roads and parking lots, but cities and towns along rivers are making significant investments to separate the outdated combined sewer overflows (CSOs) into separate sewer and stormwater systems that can better handle all the water,” says CRC Communications Director, Angela Chaffee. “These investments have made a tremendous difference in improving the health of rivers and protecting river users. Rivers are certainly much cleaner than they used to be.”

The second way to know if rivers are clean is to visit CRC’s “Is It Clean?” website located at to find bacteria test results for nearly 200 river access and recreation sites in Vermont, New Hampshire, Massachusetts, and Connecticut. The site is also available in Spanish at “It’s smart for river users to visit the ‘Is It Clean?’ website and pay attention to the bacteria test results so they know when it’s clean for swimming or boating,” notes Chaffee.

Each summer, CRC and more than 20 partner organizations deploy trained volunteers to collect water samples from popular boat launches and swimming holes. The samples are tested for E. coli bacteria, which could potentially make you sick and may suggest the presence of other waterborne illness-causing pathogens. Samples are typically collected at each site weekly or bi-weekly and test results are posted online 24-hours later. Water samples are collected from June through early October. Water sample results are color-coded and map-based so users can easily see where bacteria levels are high.

This information gives river users information they can use to make informed decisions and keep from getting sick. Yet, river conditions are constantly changing. That means a change in weather since the bacteria samples were collected will result in different bacteria levels at any site at a given time – rain tends to cause bacteria levels to increase while dry weather results in lower bacteria levels. The website provides bacteria data for the Connecticut River and more than 20 tributaries, including the Chicopee River and Deerfield Rivers in MA, the Scantic and Farmington Rivers in CT, the West and Black Rivers in VT, the Ashuelot River in NH, and many more.

About the Connecticut River Conservancy

Since 1952, Connecticut River Conservancy has been the voice for the Connecticut River watershed, from source to sea. They collaborate with partners across four states to protect and advocate for your rivers and educate and engage communities. They bring people together to prevent pollution, improve habitat, and promote enjoyment of your river and its tributary streams. Healthy rivers support healthy economies. To learn more about CRC, or to make a contribution to support this work, visit