List of Parameters

Parameter	Potential Impacts	Potential Causes
Ammonia-N (NH₃-N)	Elevated levels of ammonia can injure or kill aquatic life, such as fish and invertebrates. In fish, even low concentrations of ammonia can damage sensitive tissues such as gills, deplete natural resistances to bacterial infections, and hinder reproductive capacities and growth.	Ammonia occurs naturally as a by-product of protein metabolism and decomposition. Ammonia can also enter a water body from runoff of fertilizers, livestock waste, and discharges of untreated sewage and industrial wastewater.
Chloride (Cl^-)	Although small amounts of chlorides are essential to proper cell function in plants and animals, large concentrations of chlorides can damage aquatic life physiology and hinder reproductive fertility and growth.	Chlorides occur naturally from the weathering and erosion of sedimentary rocks. Agricultural runoff, industrial wastewater, petroleum industrial activities, salt water intrusions, and effluent from wastewater treatment facilities are sources of chlorides.
Chlorophyll-a	Chlorophyll-a, a photosynthetic pigment found in green plants, is an indicator of the presence of algae in water. It is used to monitor the biological productivity of lakes and streams.	Elevated levels of nutrients could result in an overabundance of algae.
Dioxin	Dioxin is a family of polychlorinated chemicals. a carcinogen, it is detrimental to animal and human health.	Dioxin is present in the waste from the paper bleaching process and from the combustion of chlorinated compounds.
Dissolved Oxygen (DO)	Oxygen is the most important component for the survival of aquatic life. Dissolved Oxygen is essentially the amount of oxygen available in water. Low dissolved oxygen can suffocate aquatic species.	Elevated levels of organic nutrients can cause an overabundance of bacteria and algae, which depletes oxygen from water. Human-caused increases in water temperature industrial discharges can also lower the capacity for water to hold oxygen.
E. coli and Enterococci Bacteria	Escherichia coli (E. coli) and enterococci are bacterial indicator species for the presence of fecal matter, pathogenic bacteria, and viruses. E. coli is the indicator bacteria for freshwater, while enterococci are used as an indicator in saltwater.	Malfunctioning or failing on-site sewage facilities (OSSFs), untreated domestic sewage, improper disposal of grease, and runoff from agricultural and livestock activities can cause an overabundance of bacteria and other pathogenic organisms.
Flow Instantaneous Flow (Quantitative) Flow Severity (Qualitative)	Flow conditions affect water quality. Aquatic species are adapted to specific instream flow patterns. Low flow events, associated with hot summer months, can severely alter a stream habitat. High flow events, such as those associated with heavy rain, can also disrupt an aquatic habitat.	Drought or heavy rain events can disrupt normal flow patterns. Impediments such as fallen trees, beaver dams, or man-made dams can disrupt or alter in-stream flow.
Nitrogen Nitrate-N (NO₃-N) Nitrite-N (NO₂-N)	An abundance of nutrients can increase plant and algal growth. Bacteria use oxygen in the decomposition of plant matter, which can reduce dissolved oxygen. Nitrites are an intermediate form of Nitrogen can cause brown blood disease in fish by preventing the transfer of oxygen by hemoglobin. Nitrites can also adversely affect human health.	Nutrient sources are usually found in runoff from fertilizers and livestock facilities. They are also present in the effluent of wastewater treatment facilities.
pH	Aquatic organisms have evolved to live in a specific range of pH. Biological and chemical processes can be altered or affected if the pH drops or rises over certain thresholds. Fish species cannot survive if the pH drops below 4 or rises above 12.	Runoff from mining operations and discharges of industrial wastewater can alter the pH of a water body.
Phosphorus Total Phosphate-P	Most phosphorus compounds found in water are phosphates. Orthophosphate is consumed by aquatic plants and organisms and is considered the limiting factor for aquatic plant growth. High or excessive levels of orthophosphate results in higher yield in growth. Excessive plant growth can cause eutrophication, (the natural aging progression of a water body) which can decrease dissolved oxygen.	Phosphates occur naturally from the decomposition of organisms and the weathering of rock material. It can also result from fertilizer runoff.
Polychlorinated biphenyls (PCBs)	PCBs are acutely toxic, and can disrupt endocrine and neural processes in aquatic life and humans.	PCBs are found in dielectric fluids used in transformers, capacitors, and coolants.
Salinity	Salinity is the measurement of conductive ions in the water. High levels of sodium sulfate and magnesium sulfate produce a laxative effect in drinking water. High levels of total dissolved solids can cause an unpleasant taste in potable water.	Weathering or erosion of rocks, salt mining, and salt water intrusions are sources of increased salinity.
Secchi Transparency	Secchi transparency is used to calculate the depth at which natural light can penetrate the water column. It also used as a measurement of eutrophication.	An abundance of algae and plants or excessive levels of total suspended solids can decrease the ability for light to transmit through the water column.
Specific Conductance	Specific conductance is the measure of the water’s capacity to carry an electrical current. It is indicative of the amounts of total solids present in a water body.	The conductivity of water is increased by the presence of salt-forming substances such as sulfate, chloride, and sodium.
Sulfate (SO₄^2-)	In the absence of oxygen and with a pH below 8, bacteria can reduce sulfate ions to sulfide ions. Sulfide ions can cause serious and unpleasant odor problems. Sulfates in sediment can also alter soil composition and hinder or prevent growth of native plants.	Sulfate is derived from rocks and soils containing gypsum, iron sulfides, and organic compounds. Sulfur-containing fossil fuels, heavy industrial activities, and some fertilizers are also potential sources for sulfates.
Temperature	The types of aquatic life that can survive in a water body are dependent upon water temperature. Water temperature can affect levels of dissolved oxygen. Water with a high temperature has less capacity to hold oxygen. As the water temperature drops, cold-blooded animals such as fish can become more susceptible to pathogenic stress or shock, which can lead to infections or death.	Releases of water from reservoirs can contribute to drops in temperature. Temperatures can increase with the removal of flora from riparian areas or from the release of heated water from industrial activities.
Total Dissolved Solids (TDS)	Elevated amounts of total dissolved solids can be corrosive to sewer and plumbing fixtures. High TDS may also affect the aesthetic quality of water.	Elevated amounts of TDS occur naturally from salt deposits, salt water intrusions, and sedimentary rock high in carbonate. Salt mining, petroleum exploration, potable water treatments, wastewater discharges, and chemical, stormwater, or fertilizer runoff can increase the amounts of TDS.
Total Suspended Solids (TSS)	An increase in the amount of total suspended solids can decrease the ability for light to penetrate through the water column. This can decrease the productivity of aquatic plants. As excessive amounts of TSS settle and become sediment, benthic habitats can be altered or destroyed.	High erosion events, usually coinciding with the removal of riparian floral species and severe flow events, can create excess levels of total suspended solids. Unsound agricultural practices can also contribute to soil erosion into waterways.