Created on Thursday, 17 July 2008 06:11
Last Updated on Thursday, 17 July 2008 06:12
Water samples taken by Friends of the Mad River (FMR) volunteers on Tuesday morning, July 15, show favorable swimming conditions with three tested in violation of Vermont's water quality standards. Downstream sites 23, 27 and 29 were in violation of the Vermont standard (no more than 77 colonies of E. coli per 100 ml water).
The state water quality standard for recreational waters measures E. coli bacteria, an indicator of pollution from human or animal waste. High E. coli levels can pose a danger to swimmers since the presence of fecal borne pathogens is likely. At the time of sampling there were mostly favorable swimming conditions shown in the watershed, exhibited by relatively low E. coli levels. E. coli levels tend to rise when rain washes pollutants into the river.
The volume of water flowing in the Mad River was low and declining at the time of sampling. After a moderate storm moved through the area on Sunday, drier weather late Sunday and into Monday allowed water levels to begin to decline. At the time of sampling on July 15, the water level at the U.S. Geologic Survey station in Moretown was at approximately 83 cubic feet per second, which is below the mean value for this date (103 cubic feet per second).
After the discovery of the invasive nuisance algae didymo in the Mad River last week, Mad River Watch adapted the sampling protocol to include a brief assessment of didymo. Mad River Watch volunteers take steps to prevent the spread of didymo, including carrying a portable disinfection kit to use as they collect at different sites. The volunteers met this past Saturday with FMR coordinator Caitrin Noel for a brief introduction to didymo and how to identify it. The volunteers will make observations about the presence and abundance of didymo each time they visit their sampling sites, allowing us to track the algae over time.
Noel and the volunteers spotted didymo at the following sites this week: Warren Village near the Park and Ride, downstream of Riverwatch Lane, Riverside Park, Punch Bowl, and Lareau swim hole. Didymo is not a risk to swimmers or pets. For more information about didymo, visit www.FriendsoftheMadRiver.org
For more information about E. coli and the Mad River Watch program or to report a river-related illness call 496-9127. Noel thanked this week's Mad River Watch volunteers; samplers this week included Michael Ware, Patti and Cyril Greene-Swift, Elizabeth Walker, Montserrat Carbonell, Cathy Glick, and Pam and Kathryn Barnes. Cyndee Button posted results and did the lab work.