Physical Characteristics Indicators

Color

Natural waters may have yellow-green color; other colors may indicate substantial pollution or pipe corrosion; aesthetically unacceptable. Color makes water unpleasant for use. Organic matter very frequent contributes to color. Even very small amounts of it can result in an unacceptable color.

Odour

These are usually caused by complex organic substances of natural or organizational origin, and are responsible for most of the complaints. Here if wastewater has a distinctive “rotten egg” odour, hydrogen sulfide gas is present. A major cause of taste and odour problems is metabolites produced through actinomycetes, algae, and other microorganisms.

Temperature

Causes of temperature change involve weather, removal of shading stream, bank vegetation, and impoundments, discharge of urban storm water, cooling water, and groundwater inflows to the stream. Temperature affects various physical, biological and chemical characteristics such as amount of oxygen that can be dissolved within water, metabolic rates of animals, rate of photosynthesis of plants and the sensitivity of organisms to toxic wastes, parasites, and diseases. Thermal pollution is an increase in temperature caused by adding relatively warm water to cooler stream water. The warm water could be stormwater running off warmed urban surfaces, like as streets and parking lots that are frequent constructed of black, heat-absorbing asphalt. Turbidity within water raise the amount of heat absorbed from sunlight. Measurement of temperature modification could help detect sources of thermal pollution and suggest the size of habitat for organisms that are more sensitive to temperature variation.