The effect of the following constituents on the streams are as follows:

Inorganic dissolved solids:

• The inorganic salts which are present in most industrials waste as well as in nature itself cause water to be hard and make a stream undesirable for industrial, municipal and agricultural usage.

• Salt laden water deposits scales on municipal water distribution pipeline increasing resistance to flow and lowering the overall capacity of the lines.

Suspended solids:

• They settle to the bottom or wash up on the banks and decompose causing odour& depleting the oxygen in the river water.

• Fish often die because of a sudden lowering of oxygen content of a stream

• Solids that settle to the bottom will cover their spawning grounds & inhibit propagation.

• Visible sludge creates unsightly condition & destroys the use of river for recreational purpose.

• This solid also increases the turbidity of the water courses.

Colour producing materials:-

• Colour is contributed by textile and paper-mills, tanneries, slaughter house and other industries is an indicator of pollution.

• Compounds present in water absorb certain wavelength of light and reflect the remainder.

• Colour interferes with the transmission of sunlight into the stream and therefore decreases photosynthetic action.

• It may also interfere with oxygen absorption from the atmosphere although no positive proof of this exists.

• Visible pollution often causes more troubles for industry than invisible pollution.