With crisp fall temperatures in the air, Friends of the Mad River’s Mad River Watch (MRW) Program results from the sixth and final round of water sampling show four sites with unfavorable swimming conditions as of Monday morning, August 22. Tremblay Road Pines and Meadow Road bridge in Waitsfield as well as the village swim area and Ward Access in Moretown were well over the Vermont Department of Health/EPA accepted “swimmable” E. coli level of 235 colonies per 100 ML of water. It is estimated that at the level of 235 colonies E.coli per 100 ML water, approximately eight out of every 1,000 swimmers are likely to contract a waterborne illness related to fecal contamination.
After five sampling days without substantial rain, this is the first of the season that captured the impacts on the water quality of stormwater running off the landscape. Rains carry sediments, nutrients and pathogens from the land into the river and streams, increasing E. coli levels (among other pollutant levels). During dry weather, the pollutants don’t reach waterways. After an overnight rain, the flow condition of the Mad River at the time of sampling Monday morning was high and had just started declining (HD), flowing at 264 cubic feet per second (cfs) at the USGS flow gage in Moretown.
“All four E. coli violations occurred in the lower half of the watershed, consistent with historical trends that the lower watershed is more impaired for E. coli. Yet, it is also possible that pollutants from the upper watershed had already moved downstream and weren’t captured in our mid-morning sampling. The median for this date is 76 cfs,” said Corrie Miller, executive director of Friends of the Mad River.
“Friends of the Mad River’s E. coli sampling results are only a snapshot in time intended to give you a sense of the conditions that lead to high pathogen levels in the water so you can be informed. This weekend looks to be a wet one, so you and your good judgement are your best protector – use common sense and don't swim for at least 24 hours after a rain,” Miller added.
This week’s Mad River Watch volunteers included Richard Czaplinski, Susy Deane, Annie and Jula Fender, Annie and Hazel Plewak, Kinny Perot, Fran and Gary Plewak and Michael Ware. Susanne and George Schaefer who drove water samples to the lab in Burlington for phosphorus, nitrogen and turbidity analysis and Sally Boudreau posted data at 10 swim holes across the watershed. Paula Baldwin ended her first year at the helm of FMR’s lab.
For more information about E. coli and the Mad River Watch program and to view the most recent complete data report visit the Friends of the Mad River website at www.FriendsoftheMadRiver.org. Results are also available on Facebook (“Friends of the Mad River”) and on signposts at swim holes across The Valley.