Under the Water Resources Act 1991, it's an offence to cause or knowingly permit any poisonous, noxious or polluting material, or any solid waste to enter controlled waters. Where pollution is highly likely the Environment Agency can prevent entry, remover pollutants, mitigate the effects of pollution and restore the quality of the controlled waters in question. The offender is liable for all the expenses involved in these activities.

Under section 85 of the Water Resources Act 1991, anyone found guilty of polluting controlled waters or of contravening the conditions of a consent or of failing to obtain a consent to discharge may face the following penalties:

• On summary conviction: a fine of up to £20 000 and /or imprisonment for up to 3 months.
• On indictment: an unlimited fine and/or imprisonment for up to 2 years.