FRESHWATER POLLUTION

What constitutes pollution? Any

substance which doesn’t belong in the water and causes harm.

Sources of Pollution Pollution can come from a variety of

sources. Point sources: A specific source of

pollution which can be easily identified. Non-point Sources: A widely spread out

source of pollution which cannot be easily identified.

Pollution in the Food chain

Human Wastes

Cities and urban areas produce huge amounts of waste materials.

Most wastes are filtered and removed with water treatment plants.

Serious flooding can cause drains to overflow and spill into surface water.

Industrial Wastes

Many factories and industries produce large amounts of waste. Chemicals: Toxic wastes may leak into

the soil and freshwater. Smoke and Exhaust: Smokestacks can

release various pollutants into the atmosphere along with water and carbon dioxide.

Heat Pollution: Water used to cool factory machinery can runoff into rivers and warm them.