Crops contain high concentrations of Nitrate when excess fertilizer is used.

Also, excess fertilizer increases run-off (which is not beneficial to waterways) as the nutrients are not readily absorbed.

Of particular concern are hazardous waste dumps and landfills, and, in agriculture, excess fertilizer, improperly stored animal manure, and biocides (e.g. pesticides, fungicides, insecticides and herbicides).

They say that this sort of application economy goes a long way toward lawn health - but also keeps excess fertilizer out of the water system since less is lost to the environment through runoff.

Causes include water pollution from sewage or runoff from farms (carrying excess agricultural fertilizer).

Cities and industrial sites use rivers as sewers; excess fertilizer and pesticides from farms leach into canals and streams.

Switch grass cleans water as well as air; its wide-spreading roots filter out pesticides, herbicides and excess fertilizer before they reach the waterways.

Nitrates enter the stream system from excess fertilizers applied to land uses in the drainage basin and may also be present in septic wastes improperly entering the creek.

In most cases of excess nitrate concentrations in aquatic systems, the primary source is surface runoff from agricultural or landscaped areas that have received excess nitrate fertilizer.

This has a direct effect on soil particles, along with excess fertilizers and other chemicals, washing into local waterways, damaging water quality and harming aquatic life.