The bacteria monitoring program was launched in July 2012. Our volunteers monitor sites once per month from February to November using Coliscan© Easygel. Bacteria levels are one indicator used to determine if water is safe for swimming or other recreation. We monitor fecal bacteria levels, specifically Escherichia coli (E. coli), which are bacteria found in the intestines and fecal matter of warm blooded animals.
Click on a site on the map to see recent data collected by RCA Volunteers.
What do the scores mean? Bacteria scores reflect the number of E. coli colonies per 100 milliliters of water. The maximum allowable amount of E. coli bacteria in a single sample of water is 235 colonies per 100 milliliters. This standard is set by the VA Department of Environmental Quality. High counts of E. coli in a stream indicate that there is an elevated risk of illness from pathogenic organisms. Frequently Asked Questions about bacteria in the Rivanna Watershed