PRLAC Water Monitoring Program
What is it that we monitor?
Beginning in the summer of 2002, the Pemigewasset River Local Advisory Committee began monitoring the quality of the water at six sites along the river. The group was supplied with a testing kit and training through the NH Department of Environmental Services’ (NH DES) 
Volunteer River Assessment Program (VRAP). A seventh site along the Pemi has been added as well as sampling where the Mad, Newfound, and Smith Rivers enter the Pemi. Six river characteristics are measured: water temperature, pH, turbidity, dissolved oxygen (mg/L), dissolved oxygen (% saturation), and conductivity. In 2005 PRLAC was awarded a grant from Franklin Savings Bank to purchase water monitoring equipment that met NH DES standards. Since that time NH DES staff have supplied training, technical assistance and expendable supplies.
What follows are descriptions of these water characteristics as well as what effect they have on other water features as well as organisms living in the water. Where appropriate, information is also included about how a particular attribute is affected by other characteristics. The descriptions are followed by Table 1, which shows the NH DES Class A and Class B standards for each parameter and an interactive map with site specific data links. Descriptions of additional characteristics are included at the end of this page.
The Pemigewasset River is classified as a Class B River, fishable and swimmable, but not a source of public drinking water.
Results
- Our results are reported to NH DES and also US EPA. View reports, data, and maps on the NH DES Volunteer River Assessment Program (VRAP) for the Pemigewasset River.
- To view the 2020 Pemigewasset River Watershed Data, click here.
- To view the 2021 Pemigewasset River Watershed Data, click here.
Table 1: Abbreviated List of Water Quality Standards for New Hampshire Surface Waters
|
Parameter |
Class A Standard |
Class B Standard |
|
Temperature (a) |
No change in temperature, unless naturally occurring. |
Shall not impede designated uses. |
|
Dissolved Oxygen (DO) |
Minimum of 6.0 mg/l (based on any single sample). |
Minimum of 5.0 mg/l (based on any single sample)c, unless naturally occurring. |
|
Dissolved Oxygen (DO) |
Minimum of 75% saturation (based on daily average of all samples). |
Minimum of 75% saturation (based on daily average of all sam.ples)c, unless naturally occurring |
|
pH |
Shall be as naturally occurs. |
Within the range 6.5-8.0, unless due to natural causes. |
|
Conductivity (b) |
-- |
-- |
|
Turbidity |
Shall not exceed 0 NTU, unless naturally occurring. |
Shall not exceed naturally occurring conditions by more than 10 NTUs. |
|
E. coli (bacteria) |
Maximum of 47 cts/100ml (based on geometric mean of at least 3 samples over a 60-day period), unless naturally occurring. |
Maximum of 126 cts/100ml (based on geometric mean at least 3 samples over a 60-day period), unless naturally occurring. |
|
E. coli (bacteria) |
Maximum of 153 cts/100ml (based on any single sample), unless naturally occurring. |
Maximum of 406 cts/100ml (based on any single sample), unless naturally occurring. |
|
BOD5b |
-- |
-- |
|
Total Kjeldahl nitrogen (TKN) |
Shall contain no nitrogen unless naturally occurring. |
No quantitative standard exists. However, nitrogen should not occur in any concentration that would impair designated uses, unless naturally occurring. |
|
Nitrate (NO3) |
Shall contain no nitrogen unless naturally occurring. |
No quantitative standard exists. However, nitrogen should not occur in any concentration that would impair designated uses, unless naturally occurring. |
|
Total phosphorus (TP) |
Shall contain no phosphorus unless naturally occurring. |
No quantitative standard exists. However, phosphorus should not occur in any concentration that would impair designated uses, unless naturally occurring. |
(Source: NH DES)
Why Coliform Bacteria is Important: Total coliform bacteria are a collection of relatively harmless microorganisms that live in large numbers in the intestines of man and warm- and cold-blooded animals. They aid in the digestion of food. A specific subgroup of this collection is the fecal coliform bacteria, the most common member being Escherichia coli. These organisms may be separated from the total coliform group by their ability to grow at elevated temperatures and are associated only with the fecal material of warm-blooded animals.
Environmental Effects: The presence of fecal coliform bacteria in aquatic environments indicates that the water has been contaminated with the fecal material of man or other animals. At the time this occurred, the source water may have been contaminated by pathogens or disease producing bacteria or viruses which can also exist in fecal material. Some waterborne pathogenic diseases include typhoid fever, viral and bacterial gastroenteritis and hepatitis A. The presence of fecal contamination is an indicator that a potential health risk exists for individuals exposed to this water. Fecal coliform bacteria may occur in ambient water as a result of the overflow of domestic sewage or nonpoint sources of human and animal waste.
Why Nitrate, Nitrite, and Nitrogen Are Important: Nitrogen is one of the most abundant elements. About 80 percent of the air we breathe is nitrogen. It is found in the cells of all living things and is a major component of proteins. Inorganic nitrogen may exist in the free state as a gas N2, or as nitrate NO3-, nitrite NO2-, or ammonia NH3+. Organic nitrogen is found in proteins and is continually recycled by plants and animals.
Environmental Impact: Nitrogen-containing compounds act as nutrients in streams and rivers. Nitrate reactions [NO3-] in fresh water can cause oxygen depletion. Thus, aquatic organisms depending on the supply of oxygen in the stream will die. The major routes of entry of nitrogen into bodies of water are municipal and industrial wastewater, septic tanks, feed lot discharges, animal wastes (including birds and fish) and discharges from car exhausts. Bacteria in water quickly convert nitrites [NO2-] to nitrates [NO3-].
Why Phosphorus Is Important: Phosphorus is one of the key elements necessary for growth of plants and animals. Phosphorus in elemental form is very toxic and is subject to bioaccumulation. Phosphates (PO4---) are formed from this element. Phosphates exist in three forms: orthophosphate, metaphosphate (or polyphosphate) and organically bound phosphate. Each compound contains phosphorous in a different chemical formula. Ortho forms are produced by natural processes and are found in sewage. Poly forms are used for treating boiler waters and in detergents. In water, they change into the ortho form. Organic phosphates are important in nature. Their occurrence may result from the breakdown of organic pesticides, which contain phosphates. They may exist in solution, as particles, loose fragments, or in the bodies of aquatic organisms.
Environmental Impact: Rainfall can cause varying amounts of phosphates to wash from farm soils into nearby waterways. Phosphate will stimulate the growth of plankton and aquatic plants, which provide food for fish. This increased growth may cause an increase in the fish population and improve the overall water quality. However, if an excess of phosphate enters the waterway, algae and aquatic plants will grow wildly, choke up the waterway and use up large amounts of oxygen. This condition is known as eutrophication or over-fertilization of receiving waters. The rapid growth of aquatic vegetation can cause the death and decay of vegetation and aquatic life because of the decrease in dissolved oxygen levels.