Water Quality Monitoring
Water quality monitoring has always been a priority of the PMNRCD and the PMWP. Focus groups and surveys in 2002 indicated a strong interest by the public in increased education about local water quality. Later, the Poultney Mettowee Basin Plan included 12 strategies directly related to water quality information, resulting from three years of a detailed public involvement process.
Since 2003, the Partnership has conducted a formal water quality monitoring program along the Poultney River. In 2005, the Partnership expanded this monitoring to include the Mettowee River, Flower Brook and Beaver Brook. In 2006, we added the Castleton River and the Hubbardton River.
This project began with the volunteer help of high school students from Middletown Springs, and is greatly dependent on the assistance of interested residents. A number of different water quality indicators are monitored including water temperature, water depth, turbidity, odors, algae growth, phosphorus concentration and bacterial contamination.
Since 2003, the Watershed Partnership has been awarded a laboratory services grant through a program designed by the State to help Vermont's many volunteer watershed associations and water quality monitoring groups . Samples are analyzed by the Vermont Department of Environmental Conservations (DEC) LaRosa Analytical Laboratory in Waterbury, Vermont. Due to rigorous data quality checks, data analyzed at the LaRosa Lab meets Federal data submission requirements and is used by the US Environmental Protection Agency (EPA).
Bacteria monitoring is used to show if water contains human pathogens that could elevate the risk of contracting a swimming-related illness. The Partnership's monitoring project is looking for contamination from bacteria called E. coli (Escherichia coli). The presence of E. coli is attributed to fecal contamination from untreated sewage or the feces of pets and livestock. According to a Vermont Water Quality Division Report, although not usually life threatening, E. coli is dangerous in high amounts because it can cause adverse health effects through bacterial infections. It is linked to increased gastrointestinal and upper respiratory tract disorders.
The US EPA water quality standards for swimming areas state that E. coli levels should not exceed 235 E. coli/100ml of water in a single sample. Vermont E. coli standards are more stringent than the US EPA recommendations. They recommend 77 E. coli/100ml of water (single sample) as the upper limit for swimming areas.
Hilary to add paragraph re: turbidity and phosphorus numbers
Water quality monitoring sites 2006 map
Table of results 2006
Link to 2003
2003 Sampling Sites map
2003 table of results
Link to 2004
Click link below to see full size map of 2003 and 2004
Preliminary Results for E. coli testing Summer 2004
Link to 2005
Water Quality Monitoring Sites 2005
Also want link to annual water quality newsletter put in adobe
Each link should include graphs and maps
Tom: What should we do for all of these results?? We have Turbidity and Total Phosphorus results, too And a report that we publish every year detailing the results. Can we link to all of this data?? Or the reports??
Why measure E. coli?
Source: Citizen's Guide To Bacteria Monitoring In Vermont Waters (Water Quality Division VT Department of Environmental Conservation, April 2003).
Bacteria monitoring is limited in the amount of information it can tell you. It is called bacteria monitoring because the amount of a certain bacteria is what is actually measured. The resulting measurement is used to infer the likelihood that the water contains human pathogens that would elevate the risk of contracting a swimming-related illness. This prediction is not without flaw, but it is the best available approach to date.
The primary indicator of fecal material in water used in most freshwater monitoring efforts is Escherichia coli. Since E. coli is a constituent found in the intestines of humans and other warm-blooded animals, when found in rivers, lakes, ponds, streams, or drinking water, it means that somehow fecal material has made its way into the water. E. coli is therefore used as an indicator of potential fecal contamination of the water. While some strains of E. coli are pathogenic in and of themselves, the presence of E. coli is used in monitoring programs to indicate that other fecally transmitted pathogens like live viruses, bacteria, protozoans or worms may also be present. While fecally-contaminated water may have pathogens present, many times pathogens cannot survive outside the intestines for long periods of time and therefore are not alive (Schaechter, 1992). To be prudent, it is assumed that if E. coli is present, live contagious viruses or pathogens may have been present in the source fecal material and thus may now be in the water.
How much E. coli is too much?
One of the things people love about Vermont is swimming in the great outdoors and enjoying the wide variety of wildlife with which we share our state. Naturally, some waste' from wildlife makes it into our waterbodies. But, this does not necessarily mean we are going to contract gastroenteritis or any other illness from swimming in these waters. The more fecal contamination that enters a waterbody, the more likely that human viruses and pathogens are going to be present. How do we know when the level of fecal contamination is high enough to increase our risk of illness to an unacceptable level? One way is to measure the amount of E. coli in swim waters and then record the number of people who become ill afterwards. This is repeated over and over under a wide range of E. coli measurements. The ensuing illness rate is then related to the amount of bacteria measured.
The U.S. Environmental Protection Agency (EPA) has used findings from epidemiological studies just like this to develop recommended criteria for water quality standards (U.S. EPA, 1986). EPA decided that 8 in 1,000 swimmers getting sick would be an acceptable level of risk, and set their most stringent single sample criterion at 235 E. coli organisms/100 milliliters (ml) of water, which corresponds to this illness rate. By the federal criterion, as long as E. coli derived from a single sample collection remains below 235 E. coli /100ml, waters are considered safe to swim in.
So the presence of E. coli indicates that there may be pathogens in the water that may make humans sick, but it is not an actual measurement of those pathogens. We tend to think that all bacteria are bad, but bacteria are as important a component of the ecosystem as they are of our own internal' fauna. Therefore, we must coexist with some level of fecal contamination in our waterbodies
In 1986, the United States Environmental Protection Agency published its national Ambient Water Quality Criteria for Bacteria document (EPA, 1986). States were strongly encouraged to adopt the criteria in the document or ones more stringent. In 2002, EPA issued updated guidance for implementing the 1986 criteria (EPA, 2002a). EPA recommends that States set their freshwater quality standard to correspond to an illness rate of 8 illnesses per one-thousand swimmers. EPA's studies (discussed above) tell us that a 5-sample geometric mean of 126 E. coli /100ml, or a single sample of 235 E. coli /100 ml, indicates a likely illness rate of 8 per 1000 swimmers. EPA will allow States to establish standards that correspond to illness rates up to 14 illnesses per thousand swimmers (five-sample geometric mean of 548 E. coli /100ml or a single sample in excess of 1,021 E. coli /100ml) for swimming in freshwater (see Section 4.1.1 of EPA, 2002a). States can use the geometric mean of at least five samples collected during a 30-day period, or use a single sample value, or a combination of both to determine whether a waterbody meets the criteria.
It is not until their adoption as part of a state's water quality standards that the criteria become legally binding (EPA, 1986). Vermont has adopted a water quality standard for E. coli bacteria for Class B waters that is far more strict than EPA's recommendation. Vermont's Class B standard is 77 E. coli /100ml in a single sample. This is the most stringent standard in the nation. Based on EPA's epidemiological studies, Vermont's standard level equates to an illness rate less than four per 1,000 swimmers.
To be precise about it, the meaning of Vermont's standard is as follows. At 77 E. coli /100 ml, we can be 75% certain that 3.4 persons in 1,000 will get sick, assuming that they are swimming at a beach with very heavy use, that is influenced by some level of waste discharge. To be 95% certain that 3.4 individuals per 1000 swimmers would become ill, the single sample value would increase to 187 E. coli /100 ml.
For a variety of reasons, the highly strict nature of Vermont's present standard produces an impractical situation in terms of assessing real risks to swimmers and determining where bacterial pollution is a real issue. In fact, recent local studies (Sargent and Morrisey, 2000; Moir, 2003) tell us that under moderate rainfall, E. coli will be found in waters running off of completely undisturbed, forested watersheds at levels in excess of 77 E. coli /100ml.
Note: It is the intent of the District and the Partnership to provide science-based information related to water quality to help inform and educate individuals so that they are able to then make their own decisions about these issues.
Poultney - Mettowee