Sampling results from the second round of Friends of the Mad Riverís Mad River Watch volunteer water quality program show only some sites with favorable swimming conditions, with 11 of thirty-five sites testing above Vermont Health Departmentís water quality standard for E.coli in recreational waters. The standard was recently revised upwards, increasing from 77 to 235 colonies of E.coli per 100 mL water. E. coli is a type of coliform bacteria and is used as an indicator of pollution from human or animal waste and the potential presence of disease causing organisms. It is estimated that at the level of 235 colonies E.coli per 100 mL water, approximately 8 out of every 1,000 swimmers are likely to contract a water borne illness related to fecal contamination.
View table of results from 6-25-12 sampling (pdf)
Spring 2012 was relatively dry in contrast to a very wet Spring of 2011, which saw record breaking precipitation. At the time of sampling on Monday morning, the Mad River was low and rising. After an extended dry period with little precipitation, the flow had declined to approximately 40 cfs late on Sunday (as recorded at the USGS gage in Moretown), a level well below the median flow for that date. By Monday morning, with just over a tenth of an inch of rain falling overnight, the flow had increased to approximately 50 cfs. The flow continued to rise over the next few hours with continuing intermittent precipitation.
Mad River Watch data collected over the past 20+ years shows that rising flow results in rising E.coli levels. Keep in mind that when a rainstorm that turns the Mad Riverís waters brown with sediment there is also an increased health risk to swimmers. For more information about E. coli and the Mad River Watch program, to view our most recent complete data report Please visit the Friends of the Mad River website http://www.FriendsoftheMadRiver.org. Friends is a membership organization, and depends on the generous contributions of members to continue the Mad River Watch and other programs; learn how to become a member and donate securely online at our website.
Many thanks to this weekís Mad River Watch volunteers: Susy Deane, Mike Ware, Fran & Ben Plewak, Maxine Grad & Elan Shems and Dave Gould. Also, many thanks to Cyndee Button, our fabulous and hardworking volunteer Lab Coordinator.