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Pemigewasset River Local Advisory Committee (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).
Six river characteristics were measured: water temperature, pH, turbidity, dissolved
oxygen (mg/L), dissolved oxygen (% saturation), and conductivity. 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. By clicking on the highlighted text, you can view the monitoring results for each characteristic. 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. Our results have been reported to NH DES. View reports, data, and maps on the NH DES Volunteer River Assessment Program (VRAP) for the Pemigewasset River. Why Water Temperature is Important Definition: Lowland streams, known as "warmwater" streams, are different from mountain or spring fed streams that are normally cool. Effect on: Often summer heat can cause fish kills in ponds because high temperatures reduce available oxygen in the water. Affected by: Natural seasonal fluctuations, sunlight/shade, vegetation, some human activity, such as industrial effluent and cooling water. Why pH is Important Definition: pH is a measure of the acidic or basic (alkaline) nature of a solution. The concentration of the hydrogen ion [H+] activity in a solution determines its pH. The pH scale ranges from 0 to 14, with 7.0 considered neutral. Natural waters are generally between a pH of 6.0 to 9.0. Waters with pH less than 6 occur naturally, but below pH 4.0 acidic conditions exist. Effect on: Dissolved oxygen (DO) is indirectly affected by changes in 
pH. The toxicity of many compounds can be altered if pH changes, because pH
alters chemical and biological reactions and processes. Changes in pH are predominantly
related to the health of aquatic organisms, especially fish and invertebrates.
Affected by: The pH of water can be directly affected by temperature and the presence of algae. Why Turbidity is Important Definition: Turbidity is an expression of the clarity of water. It describes how light penetrates the water. Turbidity is commonly measured in NTUs (nephelometric turbidity units). Effect on: Turbidity greatly affects conductivity and may affect the types of aquatic life in water. Affected by: The amount and type of suspended sediments in the water will greatly affect the turbidity. Why Dissolved Oxygen is Important Definition: Dissolved oxygen (DO) is a measure of the amount of oxygen in a quantity of water. It is often recorded in two ways: milligrams/liter (mg/l) and percent saturation. The first is an absolute measure of dissolved oxygen, while the second compares the amount of oxygen present relative to the maximum amount that could dissolve at a particular temperature. Adequate dissolved oxygen is necessary for good water quality. Oxygen is a necessary element to all forms of life. Natural stream purification processes require adequate oxygen levels in order to provide for aerobic life forms. As dissolved oxygen levels in water drop below 5.0 mg/l, aquatic life is put under stress. The lower the concentration, the greater the stress. Effect on: DO effects aquatic organisms. It is the most important constituent for protection and propagation of fish and aquatic life. Generally, cold water fish are less tolerant to low DO levels than warm water fish. Total dissolved gas concentrations in water should not exceed 110 percent. Concentrations above this level can be harmful to aquatic life. Affected by: The amount of oxygen that dissolves in water depends on the water temperature, atmospheric pressure, and surface area of water exposed to the atmosphere. DO levels are also affected by nutrients (nitrogen and phosphorus) and algae. Why Conductivity is Important Definition: Conductivity is a numerical expression of the ability of water to carry an electrical current. It provides an estimate of the total dissolved materials present in water. Effect on: No direct effects on other parameters. Affected by: Conductivity is affected by temperature and pH. Conductivity is also affected by changes in flow, suspended sediment, and turbidity. Table 1: Abbreviated List of Water Quality Standards for New Hampshire Surface Waters
(Source: NH DES) 
OTHER TESTS 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. Visit the PRLAC overview. Visit the Pemigewasset Watershed Resource Co-occurrence Mapping and Analysis page. Adapted from "Introduction to Water Quality" NRCS/USDA, March 1998, Kentucky’s Water Watch website http://www.state.ky.us/nrepc/water/wcparint.htm and Water Watch http://www.vic.waterwatch.org.au/fortheteacher/manual/sect4b.htm |
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