The criminal offence of water pollution is defined as the entry of poisonous, noxious or polluting matter. This covers most inland and coastal waters (including groundwaters). The law has therefore clearly established the principle that such entry should be the exception and, where it is necessary, must be controlled.

The Department for Environment, Food and Rural Affairs DEFRA have included a copy of the Economic Instruments for Water Pollution (External Link) website on their website.

Their website also has a Section on Water Quality (External Link). This section provides links to material on quality of the water environment - rivers, lakes, estuaries, coastal waters and groundwater. This includes issues such as sewage treatment and disposal, bathing waters, dangerous substances, nitrates from agricultural sources, and economic instruments for water pollution.