Sampling results from the sixth and final round of Friends of the Mad River’s 2015 Mad River Watch (MRW) volunteer water quality program show no sites with unfavorable swimming conditions Monday morning after nearly two weeks without substantial rain.
The flow condition of the Mad River at the time of sampling Monday morning was low and steady (LS), measuring approximately 35 cubic feet per second (cfs) at the USGS flow gage in Moretown, down from only 51 cfs in the evening of August 20th after light rain. The median flow for August 24th is 102 cfs. None of the 36 sampling sites tested Monday above DOH/EPA safe E. coli level of 235 colonies per 100 mL of water.
Two other dates this summer also had a “low and steady” flow condition – July 13th and August 10th. On all three of these sampling dates, none of the 36 sites tested above suitable E. coli levels. On June 15th, however, when the water was “low and rising” after a storm, 10 sites violated these suitable levels. Remember that rains can cause E. coli levels to fluctuate, even on a daily basis, as water carrying pathogens moves down the watershed. You are your best protector - use common sense and let the high waters pass (along with the pollutants they carry) before jumping in!
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.
Many thanks to this week’s Mad River Watch volunteers: Paula and Charlie Baldwin, Susy Deane, Annie Macmillan, 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 and turbidity analysis, to Sally Boudreau for posting data at ten swimholes across the watershed, and to Maryellen Kinhan for completing the Wait House E. coli lab analysis. The Mad River Watch Program would not be possible without these dedicated volunteers!
Four years ago tomorrow, on August 28, 2011, Tropical Storm Irene dumped so much rain across our watershed that, at 10:15 that memorable Sunday evening, the USGS flow gage in Moretown peaked at 24,200 cubic feet per second (cfs), compared to the 35 cfs on Monday morning. Irene has since become a household name, leaving damage in its wake of a magnitude previously unimaginable. Now, four years later, our Mad River Valley community is still recovering from Irene – re-establishing our homes, businesses, and municipal facilities – and at the same time, we’re building our capacity to deal with whatever the future throws us. We’ve gone through a lot, come so far, and still have exciting and innovative work to be done.
For more information about E. coli and the Mad River Watch program, click here. To view our most recent complete data report, click here. Results are also available on Facebook (“Friends of the Mad River”) and on sign posts at swimholes across the Valley.
Friends of the Mad River is a community-supported organization committed to active and thoughtful stewardship of the Mad River and its 144 square mile watershed. We depend on the generous contributions of our members to continue the Mad River Watch and important resilience programs. It’s membership season, so please consider donating securely online at our website.