Wednesday, September 21, 2016

Addison County Riverwatch Collaborative Sept. 7 Sampling Results

Here are results from the Addison County River Watch's study of the Middlebury River and Otter Creek:
E.coli Results – Middlebury River and Otter Creek, September 7, 2016
The Addison County River Watch Collaborative sampled three stations on the Middlebury River and two stations on the Otter Creek on September 7th. The readings are as follows:
Station MIR 10.6: Natural Turnpike in Ripton 2.02 org/100mL
Stations MIR 5.7: Middlebury Gorge 3.04 org/100mL
Station MIR 1.5: Seeley Swim Hole, Shard Villa Rd. 866.44 org/100mL
Station OTR 7.3: Vergennes Falls 41.35
Station OTR 18: Weybridge Twin Bridges 4.05
E. coli is one type of fecal coliform bacteria found in the intestines of humans and other warm-blooded animals. It is used as an indicator of potential fecal contamination of waters. While most strains of E. coli are themselves not pathogenic, detection of E. coli suggests that other disease-causing pathogens may be present. The Vermont Department of Health sets a health-based safety standard for swimming of 235 organisms/100 mL.
E.coli concentrations exceeded the health standard of 235 at the Seeley Swimming Hole.
In general, area rivers were flowing at very low levels on September 7, due to persistent hot weather and lack of substantial rain. Flows are lower than normal for this time of year, due to dry conditions in the months of May, June, July and August. It is not uncommon for E.coli counts to become elevated under these conditions due to high temperatures (proliferation of bacteria) and lower dilution effects from runoff for those sources of E.coli that may be more localized (e.g., septic, agricultural ditches, beaver dams, water fowl).
This was our last sampling date of the season. Sampling will resume in April of 2017. We are very grateful to our group of volunteer samplers this year!! They make this effort possible. Contact Heidi Willis ( with questions.
(thanks to Heidi Willis for letting me share this)

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