Sources of diffuse water pollution

Agriculture

Pollution caused by agriculture can have serious effects on rivers, lakes, estuaries and coastal waters. Increases in nutrient levels can result in toxic algal blooms, resulting in adverse impacts on the food chain which supports fish, animals and birds.

A joint initiative between Defra, the Environment Agency and the Natural England partnership, is helping farmers tackle the causes of water pollution. The Catchment Sensitive Farming (CSF) initiative focuses at local level and pulls together farmers, farm advisers, conservation bodies, water companies, and a wide range of other interests.

Run-off from the impermeable surfaces of the urban or built environment can be highly polluting and can also increase the risk of flooding.

The run-off may carry a mix of polluting substances, such as toxic metals, pesticides, oils and hydrocarbons, sediments and oxygen-depleting substances. The majority of surface water discharges receive no treatment before entering rivers or streams and this can lead to poor water quality and ecological damage.

The Environment Agency is keen to promote the concept of more sustainable management of this run-off by installing 'softer' engineering systems, such as grassed swales and wetlands, as a means of controlling the rate of flow. We feel that these techniques, known as Sustainable Drainage Systems (SuDS), have much to offer to reduce pollution and flood risks.

Water pollution and small businesses

Small businesses can cause pollution for a number of reasons but it is often because they have limited funds to address environmental issues and are not fully aware of how their activities may impact on the environment.

Most pollution results from spillages, poor storage or poor handling of materials. Many incidents can easily be avoided, and small businesses have a vital role to play. The Environment Agency prosecutes offenders in the worst cases and it is committed to preventing pollution wherever it can. As part of this commitment it has produced a series of Pollution prevention guidance notes that address specific issues.

We treat discharges from abandoned mines are treated as diffuse because of the potential for widespread impacts and the uncertainties of where and when they may occur. There are two elements to the minewater pollution issue.

The first is a legacy from mines abandoned long ago. The second is the potential for pollution from mines abandoned more recently, which are currently refilling. The Environment Agency and the Coal Authority are among the organisations working closely together to address these two aspects. Both are commissioning studies into how groundwater refills in coalfields that are now closed, with a view to assessing the environmental risk that these pose for the future.