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6.13.12 Mad River Watch Results this week
By: friendv3 (friendv3) 2012.06.14

Mad River Watch kicked off its 27th season of water quality monitoring this Monday as volunteers headed to sites throughout the watershed to collect samples. The Mad River Watch program will conduct water testing every two weeks throughout the summer; results are reported in the newspaper and on signs at various swim holes.

Download a pdf of the results 

Trained volunteers with the Mad River Watch monitoring program collect samples at 36 sites throughout the watershed.  The samples are analyzed in the Friends of the Mad River lab for E.coli bacteria.  E.coli is an indicator of fecal contamination and the potential presence of fecal-borne pathogens such as Giardia and Cryptosporidium. E.coli is used to determine the approximate level of exposure to pathogens swimmers will encounter in a given water body. 

Until this year, the Vermont State Department of Health used a standard of 77 colonies of E.coli per 100 ml of water to determine whether beaches and swimming areas are “safe” was.  This year, the DOH announced that it is revising its standard to be in line with the US Environmental Protection Agency’s standard, currently 235 colonies E.coli/100ml.  Vermont’s standard of 77 was considered conservative nationally.  According to studies conducted at swim beaches, it is estimated that approximately 8 out of every 1,000 swimmers may contract a water borne disease recreating in water at the EPA standard (235).  Interestingly, the Vermont Department of Environmental Conservation is not changing their water quality standard, and will continue to use 77.

Through an ongoing partnership program with the VT State water quality lab, samples from 18 of the sites are also analyzed for phosphorus and turbidity. Phosphorus and turbidity are indicators of erosion and related sediment and nutrient pollution; data from this monitoring program can be used to focus restoration efforts and erosion control projects.

The June 11th Mad River Watch sampling results predictably showed very low levels of E.coli throughout the watershed, with the highest levels being well below the new standard of 235 at 62 colonies E.coli/100mL water.  At the time when the samples were collected, it had not rained in several days, and the water level was low (~110 cubic feet per second flow in Moretown; lower than average).  Typically, E.coli levels in the Mad River are low until a rain event washes pollutants into the river.  As dry weather returns and the river flow lessens, the E.coli levels also decline.

Many people are wondering about swimming in the river after the Great Flood of 2011 (a.k.a. Irene).  From a water quality perspective, the water is relatively safe for swimming if it has not rained recently, as explained above.  The dissolved & suspended pollutants washed in to the river during Irene are long gone.  That being said, there could be dangerous debris lurking at your favorite hole—metals, trees and other junk that have washed into the river could create a hazard.  Please look before you leap—observe any changes to the depth of the water (is it as deep as it was late year?) and look out for junk in the river before jumping in.

In addition to collecting water samples, volunteers in the Mad River Watch program also collect information about the pH level, temperature, and look for the presence of invasive species, particularly Didymo (rock snot).  Unfortunately, volunteers detected tow areas where Rock Snot is blooming in the watershed:  in the Mad River mainstem in Warren village and in the Mill Brook.  Rock Snot is considered to be an invasive species, which means that it can be transported into new habitats and “take over”.  Rock Snot is of concern as it forms dense mats of unsightly algae in fast moving, clean water.  Scientists fear that Didymo may impact fisheries.  For more information about Didymo and ways to prevent its spread, visit the Vermont Department of Environmental Conservation website:

Many thanks to this week’s Mad River Watch volunteers: Michael Ware, Fran & Gary Plewak, Susy Deane, Dave Gould, and Maxine Grad!  We would also like to thank Cyndee Button who has returned as the 2012 Mad River Watch Lab Coordinator, and is generously volunteering her time.

Please consider supporting the Mad River Watch and Friends of the Mad River with a membership donation.  You can join securely online at

For more information about E. coli and the Mad River Watch program, or to report a river-related illness call Caitrin at (802) 496-9127. 

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