E.Coli ( Escherichia coli )

Fecal coliform bacteria are found in the feces of human beings and other warm-blooded animals. Fecal coliform by themselves are generally not pathogenic. Pathogenic organisms include bacteria, viruses and parasites that cause diseases and illnesses. They occur naturally in the human digestive tract and aid in the digestion of food. However, when a human being or other warm-blooded animal is infected with disease, pathogenic organisms are found along with fecal coliform bacteria.

If fecal coliform counts are high (over 200 colonies/100 ml of a water sample) in a river or lake, there is a greater chance that pathogenic organisms are also present. Swimmers in waters with high levels of fecal coliform have a greater chance of developing a fever, nausea or stomach cramps from swallowing disease-causing organisms, or from pathogens entering the body through cuts in the skin, the nose, mouth, or ears. Some examples of diseases and illnesses that can be contracted in water with high fecal coliform counts include typhoid fever, hepatitis, gastroenteritis, dysentery and ear infections.

pH

pH is the percentage of hydrogen ions (H+) in a solution. A solution is more acidic when it contains more hydrogen ions. The level of acidity of the water is important to the plant and animal life as most organisms are adapted to living in neutral conditions.

When emissions from tailpipes and smokestacks combine with water in the atmosphere, they form sulfuric and nitric acids, then fall to the earth as acid rain, snow, hail, and fog. This precipitation mixes with water already on the earth, in creeks, rivers, ponds and wetlands. Other pollutants carried by runoff from the land, also change the acidity of the water.

Water Temperature

The rates of biological and chemical processes depend on temperature. Temperature affects the oxygen content of water (oxygen levels become lower as temperature increases); the rate of photosynthesis by aquatic plants; the metabolic rates of aquatic organisms; and the sensitivity of organisms to toxic wastes, parasites, and diseases.

Causes of temperature change include weather, removal of shading streambank vegetation, impoundments (a body of water confined by a barrier, such as a dam), discharge of cooling water, urban storm water, and groundwater inflows to the stream.

Thermal pollution is a way that the temperature of water can increase. Thermal pollution is an increase in water temperature caused by adding relatively warm water to a body of water.

Thermal pollution can come from stormwater running off warmed urban surfaces (streets, sidewalks, parking lots) and industries that discharge warm water from their facilities.

Nitrate

Nitrate is the form of nitrogen available for plant growth. When plants and animals die and decompose, ammonia is produced. Bacteria usually turn the ammonia into nitrate (NO 3 ). Pollutants such as sewage or manure however, contain much higher levels of nitrates. High levels of nitrate may get into groundwater or streams from fertilized fields, lawns, and golf courses, from septic system effluent, or from runoff of manure.

Total Phosphorus

Phosphates are a plant nutrient that can also be a pollutant. Excess phosphates in water contribute to the growth of algae, similar to nitrates. Adding phosphates to a body of water can accelerate plant growth and eventually damage an ecosystem by draining the oxygen levels when the plants decompose.

The number of aquatic plants growing in a particular area is limited by the amount of phosphorous available. In an aquatic ecosystem, excess inorganic phosphate is rapidly taken up by algae and larger plants, resulting in algal blooms, increased biochemical oxygen demand and significant impacts on water quality. Phosphorous is introduced into the environment from human activities such as: human and animal wastes, fertilizers, industrial wastes and human disturbance of the land and its vegetation.

Total Suspended Solids

The amount of total suspended solids (TSS) found in water serves to determine its relative clarity. Suspended solids in the water which create turbid (murky) conditions reduce the transmission of light. Suspended solids are varied, ranging from clay, silt and plankton, to industrial wastes and sewage.

Water loses its ability to support a diversity of aquatic organisms, becoming warmer as suspended particles absorb heat from the sunlight and cause oxygen levels to fall. Photosynthesis decreases because less light penetrates the water, resulting in even further drops in oxygen levels.

The combination of warmer water, less light and oxygen depletion makes it impossible for some forms of aquatic life to survive.

Suspended solids affect aquatic life in other ways as well. Suspended solids can clog fish gills, reduce growth rates, decrease resistance to disease and prevent egg and larval development. Particles of silt, clay and organic materials settle to the bottom, especially in areas of a river or stream that are slow moving. These settled particles could smother the eggs of fish and aquatic insects, as well as suffocate newly hatched insect larvae. Material that settles into the spaces between rocks makes these microhabitats unsuitable for mayfly and stonefly nymphs, caddisfly larvae and other aquatic insects living there.