Results are in from this first sampling week of Friends of the Mad River's 30th year monitoring water quality in the Mad River watershed!
Sampling results show all swimhole sites with favorable swimming conditions. Only one of the 36 sites - High Bridge Brook where it goes in a culvert under Joslin Hill Road - tested above Vermont’s Department of Health’s water quality standard in recreational waters (235 bacteria colonies per 100 ml of water). This non-swimhole site recorded an all-time high of 727 E. coli colonies per 100 ml on June 16. This is either an anomaly or evidence of a water quality problem; we’ll keep our eye on this site throughout the summer.
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.
After several days of rain, this weekend brought a welcome spell of dry weather and sunny skies. Down from a peak at 1010 cubic feet per second (cfs) on June 13, the flow conditions came closer to average throughout the watershed. At the time of sampling Monday morning, June 16, the flow condition of the Mad River was high and declining (HD) at about 304 cfs, as measured at the USGS gage in Moretown. Median flow for this date is 130 cfs.
Many thanks to this week’s Mad River Watch volunteers: Michael Ware, Fran & Gary Plewak, Dave Gould, Susy Deane, Cyndee Button and Cathy Glick. Also, sincere thanks to Cyndee Button, our volunteer Lab Coordinator, to Dotty Kyle and Eric Brattstrom for transporting samples to the DEC Lab in Burlington, and to Sally Boudreau for posting MRW data at swim holes.
For more information about E. coli and the Mad River Watch program, click here.
To view our most recent complete data report, click here.
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.