Rain storm brings E.coli levels up throughout the watershed
View results from 7/29/13 (pdf)
Mad River Watch volunteers collected water samples from 36
sites throughout the watershed early Monday morning. Results show 17 of 36 sites in violation of
Vermont water quality standards for recreational waters. The standard measures E.coli bacteria, which is found when there is fecal contamination
present. High E.coli levels in water indicate the likelihood of high levels of
water-borne pathogens, which can sicken swimmers. The Vermont Department of Health’s standard
for E.coli is 235 colonies per 100 ml
sample, which was recently revised upwards from a more conservative
The volume of water flowing in the river was high and
declining when the samples were collected.
A rain storm Sunday evening brought the water flow (as measured at the
stream gage in Moretown) up from 125 cubic feet per second (cfs) to a peak of
1,560 cfs early Monday. At the time of sampling, the flow was 1,110 cfs, while
the median flow for this date is 60 cfs.
Generally, E.coli levels rise
as rain washes pollutants in to the river; this was certainly the case on July
29th. Keep in mind that typically as the
flow subsides and the river becomes clear again, the E.coli levels also
A full report of sampling results for this and other dates
this summer can be found at the Friends of the Mad River website: www.FriendsoftheMadRiver.org.
Many thanks to our wonderful volunteer lab coordinator
Cyndee Button, and also to our cadre of dedicated volunteer sample
collectors. Volunteers this week
include: Chase Fortier, Fran & Gary
Plewak, Dave Gould, Mike Ware, Ann Felderman, Terry Reilly and Susy Deane.