The state water quality standard for recreational waters measures E. coli bacteria, an indicator of pollution from human or animal waste. Sixteen of 37 sampling sites tested were in violation of Vermont's water quality standard of 77 colonies per 100 milliliters of water. The bacterial pollution developed as water levels in the low river began to rise at approximately 8:15 a.m.
Flow readings at the USGS gage in Moretown (http://waterdata.usgs.gov/nwis/uv/?&site_no=04288000) increased from a low of 32 cubic feet per second (cfs) at 8 a.m. on August 6 to a high of 72 cfs recorded at 9:30 p.m. that same day. Some Mad River Watch samples were collected while the river flow was still low and declining (LD) and E. coli levels were low, while others were collected just after the river began to rise (LR).
With an increase in water flow like this, higher E. coli levels result as the land surface is "washed" and bacteria is flushed into the brooks and river. Water levels may rise over the weekend if forecasted storms amount to significant precipitation.
Water temperatures in the Mad River are still hospitable for brook trout, who can generally tolerate temperatures below 75 degrees. Above these temperatures trout will seek colder waters in the smaller tributaries.
For more information about E. coli and the Mad River Watch program or to report a river-related illness call Friends of the Mad River at 496-9127. Thanks to this week's Mad River Watch volunteers Kirstin and Eleanor Reilly, Kathryn and Pam Barnes, Patti and Cyril Greene-Swift, Katie Sullivan, Kinny Perot and Jay Meadows.
{loadnavigation}
