2008 Water Quality results

2008 Water Quality results

September 12, 2008

2008 E. coli results are in!


Since 2001, the WRP has coordinated a Water Quality Monitoring Program to better understand potential threats to water quality and public health. During summer 2008, WRP staff and volunteers kept tabs at 26 sites throughout the watershed, including popular swimming holes and locations that have the potential to become contaminated. Every Wednesday from June through August, our volunteers measured water clarity and conductivity, and collected water samples that were tested for E. coli.

What is E. coli?

E. coli is a type of bacteria that lives in the intestines of all warm-blooded animals. E. coli is easy to test for, and is therefore used as an indicator for other disease-causing bacteria in the water. In other words, a high E. coli count reveals that a variety of disease-causing bacteria from numerous sources (leaking septic systems, animal waste, etc) are in the water and could make people sick.

We monitor E. coli by measuring the number of bacteria colonies/100 mL of water. During the summer months, we find that E. coli counts can fluctuate dramatically depending on weather and other factors. Because of this, the Environmental Protection Agency (EPA) recommends that a geometric mean (an average that evens out large variations in the data) be used instead of a simple average when considering multiple samples taken from the same site over time. At the end of each sampling season, we calculate the geometric mean of E. coli at each site for the year. This allows us to identify trends at sites over time. The EPA standard for the geometric mean is 126 colonies/100 mL sample.

2008 E. coli results

4 sites exceeded the geometric mean standard in 2008. This number is down from 2007, when 7 sites exceeded the geometric mean standard. See the table below for the 2008 geometric mean data. Note: sites above the geometric mean of 126 colonies/100 mL sample are marked with an asterick (*).

Main Stem sites

Watson Park – 72
West Hartford Bridge – 34
Mill Brook – 49
White Brook – 75
First Branch at VLS – 56
Payne’s Beach – 65
Fox Stand – 88
Vermont Castings Road – 49
Bethel Bridge – 44
Mouth of Locust Creek – 107
Silver Lake – 6
Gaysville Bridge – 36
Stony Brook – 45
Tweed River – 37
Peavine Park – 89
Lion’s Club Park, Rochester – 50
Hancock Branch – 15

First Branch sites

Cilley Bridge – 200*
Chelsea Rec Park – 268*

Second Branch sites

Dugout Road – 207*
East Hill Road – 123

Third Branch sites

Stock Farm Road – 119
Golf Course Bridge – 106
Thresher Road – 7
Ayer’s Brook – 294*
Adam’s Brook – 37

For more information about water quality in the White River, visit our program site.