DEFINITION	PURPOSE OF TEST	NORMAL LEVELS	SOURCES
Alkalinity	A measure of a stream’s ability to resist changes in pH. It is often referred to as the buffering capacity of a stream, which is important because it allows a stream to neutralize acidic pollution or contamination.	It is the best measure of a stream’s sensitivity to acid inputs. Abrupt changes in alkalinity may signify pollution. Without neutralizing capacity, any acid added to a stream would cause an immediate change in pH.	Levels between 100 and 200 mg/L provide ideal buffering within a stream; endurable pH levels may be maintained at this level of alkalinity, and aquatic life may be protected from acidic shock; this occurs when there is a sudden decrease in pH that aquatic life cannot rapidly adapt to in order to survive.	Is greatly determined by the type of underlying bedrock and soil through which the water flows. High values may be caused by sewage and livestock waste. Values in excess of what bedrock types indicate as normal may be the result of sewage, livestock wastes, and/or the production of concrete. Very low readings may be due to heavy rains or other acidic contamination. Abrupt changes may signify pollution.
Aluminum	An element that rarely occurs in solution in natural water in concentrations greater than a few tenths or hundreds of a milligram per liter. The exceptions are mostly waters of a very low pH.	The dissolved aluminum in waters having low pH has a negative effect on fish and some other forms of aquatic life.	Water having a pH below 4.0 may contain several thousand milligrams of aluminum per liter. Occasional reported concentrations of 1.0 mg/L or more, having a neutral pH, and no unusual complexing ions, probably represents particulate matter.	Elevated aluminum concentrations have been observed in runoff and lake waters in areas affected by low pH precipitation.
Calcium	The most abundant of the alkaline-earth metals and is a major constituent of many common rock minerals. It is an essential element for plant and animal life and is a major component of the solutes in most natural water.		The average concentration of calcium in river water is between 13.4 and 14 mg/L.	Calcium is generally a predominant cation in river waters.
Chloride		The value of chloride, for the purpose of water quality monitoring, is its role as an indicator substance. Traced to its source, it often leads to other more serious problems.	Levels of 0-16 mg/L are considered normal, levels of 17-36mg/L are suspect, and levels greater than 36 mg/L are considered problematic. Above 400 mg/L may be toxic to aquatic life.	Is contained in rock and soil, the wastes of animals and stems from the decomposition of living things. Sources of abnormal readings could be from street salting, sewage, failing septic systems, landfills, and various industries.
Dissolved Oxygen	It is absorbed from the atmosphere and from the result of photosynthesis. Its concentration is related to the temperature and density of the water. A stream with running water will contain more dissolved oxygen than still water. Cold water holds more oxygen than warm water.	If more oxygen is consumed than produced, some organisms die due to low oxygen levels.	Some organisms require more oxygen than others and are more sensitive to sudden changes in DO than others. DEP standards are based upon the classification of the water body. Dissolved oxygen levels of at least 4-5 mg/L are needed to support a wide variety of aquatic life. Trout require at least 7 mg/L dissolved oxygen for unimpaired production. Spikes in dissolved oxygen may indicate sources of pollution. Because of its churning, running water will contain more DO than still water. Very few species can exist at levels below 3 mg/L.	Wastewater from sewage treatment plants, storm water runoff, and failing septic systems. Low values can sometimes be attributed to poorly-shaded water, which can cause warming. Plant life also influences the content. In areas of dense algae growth, DO levels are likely to drop significantly at night and increase excessively during the day. Respiration by aquatic animals and various chemical reactions consume DO in water.
Iron	Iron is an essential element in the metabolism of animals and plants. Although iron is the second must abundant metallic element on earth, concentrations in water are generally small.		A recommended upper limit for iron in public water supplies is 0.3 mg/L. Although iron is the 2^nd most abundant metallic element on earth, concentrations in water are generally small. If present in water in excessive amounts, however, it forms red oxyhydroxide precipitates.	Lower pH and higher iron concentration can occur in coalmine drainage water.
Manganese	It’s an essential element for both plant and animal life, and tends to deposit black oxide stains.	It is an undesirable impurity in water supplies.	The recommended upper limit in public water supplies is 0.05 mg/L. Manganese is often present to the extent of more than 1 mg/L in streams that have received acid drainage from coalmines.	Acid drainage from coal mines.
Nitrate	One of the forms of nitrogen found in aquatic ecosystems. Others include ammonia and nitrite. Nitrate is the most completely oxidized state of nitrogen commonly found in water, and is the most readily available state utilized for plant growth. Since nitrate plays a key role in stimulating plant growth, it is heavily used as a nutrient component of fertilizer.	High nitrate levels combined with phosphates cause excessive plant and algae growth, a deteriorating process called eutrophication. It causes changes in the types of plants and animals living in a stream, may lead to low dissolved oxygen, and may cause temperature increase. Higher concentrations in water are unsafe to drink due to the possible presence of altered forms of nitrite, which may cause serious illness to both humans and wildlife.	Unpolluted waters normally have less than 1 mg/L. The DEP water quality standard is 10 mg/L.	Fertilizer runoff resulting from improper application, failing septic systems, animal wastes from livestock confinement or manure storage areas, decomposing organic matter, and industrial discharges containing corrosion inhibitors.
Nitrogen	Exists in several forms in the aquatic environment.	At higher concentrations, water is unsafe to drink due to the possible presence of altered forms of nitrite, which may cause serious illness to both humans and wildlife.	Unpolluted water will normally have a nitrate level less than 1 mg/L. The DEP water quality standard for nitrate is 10 mg/L.	Sources of abnormally high readings could come from fertilizer runoff resulting from improper application, human and animal wastes from failing septic systems and livestock confinement areas, and decomposing organic matter.
Ortho-Phosphate	Just one form of phosphorus found in natural waters. Other forms of phosphorus found in natural waters that have not been tested include polyphosphates, and organically-bound phosphates	This is the tested form of phosphate because it is the form of phosphate used in fertilizer and applied to agricultural fields and residential lawns. Like nitrates, phosphates negatively impact water by causing accelerated rates of eutrophication.	Phosphate levels below 0.03 mg/L are generally considered to be unpolluted. Levels between 0.003 and 0.1 mg/L are sufficient to stimulate plant growth. The critical level for avoiding accelerated eutrophication is 0.1 mg/L. Levels above 0.1 mg/L are considered problem areas. There has not been a standard set for safe drinking water because humans can tolerate extremely high levels before it even takes effect on the digestive system.	Phosphates naturally found in water are derived from decomposing organic material and leaching of phosphorus-rich bedrock. Sources of abnormally elevated readings would come from fertilizer runoff, human and animal waste from failing septic systems, sewage treatment plants, livestock confinement areas, mass quantities of decomposing organic matter, industrial effluent, and detergent wastewater. Detergent wastewaters are responsible for about half of the phosphates polluting natural waters.
PH	It is based on a scale from 0 to 14. On this scale, 0 is the most acidic value, and 14 is the most alkaline value. Seven would be neutral. A change of 1 pH unit represents a 10-fold change in acidity or alkalinity. The range of freshwater is 2-12.	Variations in pH affect chemical and biological processes in water. Low pH increases availability of metals and other toxics for intake of aquatic life. It is critical to survival, growth, and reproduction of fish and macro invertebrates to maintain a constant pH. Exposure to very low or high pH may cause death or reproductive problems for fish and other aquatic life. Slight variations of pH on a daily basis or major changes over time can cause extreme stress to that species.	A range from 6.5 to 8.2 is optimal for most organisms. The DEP standard is between 6 and 9.	Dissolved minerals from rocks and soil contribute to pH, but reaction of dissolved carbon dioxide with water is a major determinant. Sources of abnormal acidic readings include acid mine drainage, industrial effluent, acid rain, sewage lagoons, and livestock containment areas. Sources of alkaline conditions include concrete plants, water treatment plants, and raw sewage
Phosphates	Organic phosphates are associated with living material and can be used by animals. It is an essential nutrient for plant and animal growth.	Slight increases may cause numerous undesirable effects, such as: accelerated plant growth, algae blooms, low dissolved oxygen levels, and death of certain aquatic organisms.	Phosphate levels below 0.03 mg/L are generally considered to be unpolluted. Levels between 0.03 and 0.1 mg/L are sufficient to stimulate plant growth. The critical level for avoiding severe impact is 0.1 mg/L.	Wastewater from sewage treatment plants, fertilizer runoff, faulty septic systems, livestock confinement and manure storage facilities.
Phosphorus	It’s an essential nutrient for plant and animal growth, and is normally in short supply in natural systems. There are many forms of phosphorus that exist, but pure elemental phosphorus is rare. Organic phosphates are associated with living material and can be used by animals, whereas inorganic phosphates are forms required by vegetation. It may be dissolved or suspended in a water body.	Slight increases may cause numerous undesirable effects, such as accelerated plant growth, algae blooms, low dissolved oxygen, and the death of certain aquatic organisms.	Phosphate levels below 0.03 mg/L are generally considered to be unpolluted. Levels between 0.03 and 0.1 mg/L are sufficient to stimulate plant growth. The critical level for avoiding severe impact is 0.1 mg/L.	It naturally exists in rocks, soil, and animal wastes. It can also come from wastewater from treatment plants, fertilizer runoff, faulty septic systems, livestock confinement areas or manure storage facilities, and detergent wastewater.
Potassium	An essential element in both plants and animals. The element is present in plant material and is lost by crop harvesting and removal, as well as by leaching and runoff acting on organic residues.	Maintenance of optimum soil fertility entails providing a supply of available potassium.	Concentrations more than a few tens of mg/L are unusual except in water having high dissolved-solids concentrations.	Sources of abnormal readings: Biological factors may be important in controlling the availability of potassium for solution in river and groundwater. At times of relatively high water discharge, many streams carry potassium concentrations nearly as high as they do at times of low discharge. This may be the result of soil leaching by runoff.
Redox Potential	The measure (in volts) of the affinity of a substance for electrons - its electronegativity - compared with hydrogen, which is set to zero. It is determined by the presence of inorganic dissolved solids, such as salts. Substances more strongly electronegative than hydrogen habe positive redox potentials.
Specific Conductance	The ability of water to conduct an electrical current, which is the measure of the quantity of ions in the water (typically measured in micromhos). It is determined by the presence of inorganic dissolved solids, such as salts.	Measurements outside the normal range for a stream may indicate the presence of a contaminant. These testing parameters serve as a check to make sure pollutants are not being overlooked that are not part of the regular sampling routine.	U.S. rivers range from 150 to 500 micromhos/cm. Conductivity beyond this range may not be suitable for certain fish and macro invertebrates. Almost any pollutant may cause a value falling outside the normal range for a site. Distilled water ranges from 0.5-3 micromhos/cm, whereas industrial effluent may be as high as 10,000 micromhos/cm.	Geologic formations have a great impact on the specific conductance of a stream. Carbonate bedrocks often yield high conductivity. Discharges to a stream can impact conductivity. Point-source discharges, as well as storm water runoff, may be contributors to excessive readings.
Sulfate	Sulfur is commonly found as a component of sedimentary and igneous rocks in the form of metallic sulfides. Sulfides are oxidized upon contact with aerated water, producing sulfate ions in solution.	Excessive levels in water may cause illness.	The drinking water standard for sulfate is 250 mg/L. Beyond this point, sulfate levels may cause illness in humans.	The combustion of fuel and ore-smelting processes are major anthropocentric causes of sulfate found in natural waters. Sulfides may also be present in soils that are oxidized through natural processes or organic waste treatment. Sulfate also occurs in evaporite sediments, such as anhydrite and gypsum. Excessively high sulfate readings are often associated with mine drainage. The oxidation of minerals like pyrite is the main culprit. High sulfate, as well as chloride concentrations, may be found in residual runoff from irrigated areas due to water that was lost through evapotranspiration.
Suspended Solids	Includes all particles in water that will not pass through a filter having openings of 0.45 microns in diameter. Typically, suspended solids include items such as soil, algal cells, and plant particles.	High levels may smother aquatic organisms.	It is recommended that suspended solids not exceed 25 mg/L. Unpolluted streams usually have concentrations less than 10 mg/L.	High suspended solids may occur below sewage treatment plants, construction sites and farms where erosion rates are high, various industries, and below algal-choked lakes.
Temperature	A key determinant of what species can survive in a particular environment.	Temperature preferences vary widely among species and all species are negatively impacted by rapid fluctuations in temperature.	Desired temperatures depend on the desired use of the water body. Life and reproductive necessities for trout are the target standards for water temperature. Growth is impaired in Brook Trout at temperatures above 19 degrees Celsius. Death will occur above 24 degrees. DEP standards dictate that a temperature no greater than 19 degrees Celsius is required to be a high quality, cold-water fishery. .	Discharges of coolant and wastewaters from industrial or utility plants, runoff from heated surfaces, and lack of stream cover to provide shade are among the top sources of thermal pollution.
Total Hardness	Calcium, magnesium, and carbonate are the major components of hardness, which is the amount of dissolved minerals in water. Minerals are dissolved from bedrock and soil as water passes through them. The calcium component of hardness is very important to aquatic life, as it is used for the cell walls of plants and the shells and bones of aquatic organisms. Hard water aids buffering capacity, as heavy metals and other toxic compounds may be more detrimental in soft water than in hard water.	Tests usually measure the calcium and magnesium carbonate concentration in a water sample. High levels of hardness can cause precipitation and deposition of calcium carbonate on the stream bottom, which disrupts normal stream activity. Water with high hardness may also cause plumbing problems.	Optimal values of hardness of aquatic life range from 100 to 200 mg/L. At levels above 250 mg/L, calcium carbonate will begin to precipitate. Hardness values should be slightly higher than alkalinity values. If there is a major difference between the two values, chloride and sulfate ions may be present.	High hardness values are often associated with limestone formations.
Total Solids	They include dissolved solids, suspended, and settleable solids. Dissolved solids are small enough to pass through a filter with holes about 2 microns (or 0.002 cm) in diameter. They are measured in mg/L and include silt, clay particles, plankton, algae, fine organic debris, and other particles.	It is tested because: aquatic organisms may shrink or swell depending on level of solids; organisms in low level solids water might swell due to water moving into its cells; and because this effect may cause organisms to float or sink in water columns to a level at which it is not adaptable.		They come from industrial discharges, sewage, fertilizer, road runoff, and soil erosion.
Turbidity	It is a measure of water clarity that measures how much the passage of light is restricted by suspended particles. It may affect the color of water.	We test it because: high levels may increase temperatures; it may lower dissolved oxygen levels; it can reduce photosynthesis; it can clog fish gills, which lowers growth rate and resistance to disease; and it can smother fish eggs and macro invertebrates.		It comes from suspended particles that include soil, algae, plankton, microbes, and other substances.
Zinc	It is essential in plant and animal metabolism. Modern industry has several applications for zinc and has helped to widely distribute it in water supplies.	Zinc can be considered an undesirable contaminant for some species of aquatic life.	Five mg/L is considered the upper limit for zinc because above this limit can be detected by taste. Concentrations in river water range from 5 to 45 mg/L.	Water is not a significant source of the element in the dietary sense. It has about the same abundance in crustal rocks as copper or nickel, and is thus fairly common. High levels in streams can mean that there is acid mine drainage.