Sampling results from the fifth round of Friends of the Mad River’s Mad River Watch (MRW) Program show one site with unfavorable swimming conditions as of Monday morning. Lareau Swimhole in Waitsfield results show 410 colonies of E. coli per 100 ML of water, well over the DOH/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 8 out of every 1,000 swimmers are likely to contract a water borne illness related to fecal contamination.
While the cause of this elevated E. coli is currently unknown, it may be due to people’s concentrated use of this site. It may also be due to contamination in our sampling or lab process. Please encourage fellow Lareau swimhole visitors to be good stewards of our water and use the porta-john and trash receptacles provided on the site, for the benefit of all.
This is the first site recorded above 235 colonies/100 ML this season. While this can be seen as positive news for the swimmers among us, consistently low E. coli levels don’t necessarily indicate a watershed without pollutants. In this case, they’re more of an indication of the dry weather patterns this summer and the resulting low river flow around MRW sampling days.
Rains carry sediments, nutrients, and pathogens from the land and into the river and streams, increasing E. coli levels (among other pollutant levels). During dry weather, the pollutants don’t reach waterways. After over a week without substantial rain, the flow condition of the Mad River at the time of sampling Monday morning was low and steady (LS) and flowing at 25 cubic feet per second (cfs) at the USGS flow gage in Moretown, lower even than its median for this date of 103 cfs.
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.
Many thanks to this week’s Mad River Watch volunteers: Charlie Baldwin, Richard Czaplinski, Susy Deane, Chase Fortier, Kinny Perot, Fran & Gary Plewak, and Michael Ware. Thanks to Susanne and George Schaefer who drove water samples to the DEC’s lab in Burlington for phosphorus, nitrogen, and turbidity analysis and to Sally Boudreau for posting data at swimholes across the watershed. The Mad River Watch Program would not be possible without these dedicated volunteers! Thanks also to Paula Baldwin who took over the helm as Lab Coordinator this year.
The river connects our Mad River Valley community and its clean water is a measure of our success as stewards of the land. For more information about E. coli and the Mad River Watch program and to view our most recent complete data report please 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 sign posts at swimholes across the Valley. Thanks to our members who make the Mad River Watch Program possible for the benefit of the whole watershed community!
If you appreciate the information we provide, please consider becoming a member or donating here.
August 8, 2016 data available here.