Water pollution

Pollution that affects our rivers, lochs and wetlands  is often characterised in two different forms:

Point source pollution can come from sewage treatment works, factories and input from fish farms. Such 'end of pipe' discharges are regulated by the Scottish Environment Protection Agency    and the impact of such discharges continues to lessen with improved regulation. However recent estimates are that point source pollution still continues to adversely affect 15 and 11% of river and loch water bodies respectively.

Diffuse source pollution can arise from run-off of soil, nutrients and pesticides caused by farming and forestry, contaminated run-off from our towns and cities, and deposition of acid pollutants from the air. Recent estimates are that diffuse source pollution is adversely affecting 25 and 17% of river and loch water bodies respectively.

The impacts of pollution can be a loss of biodiversity, the silting of fish spawning grounds, as well as adverse effects to our own health.

Most points and diffuse source pollution is regulated by SEPA under the Controlled Activities Regulations  . Scottish Natural Heritage works with SEPA to ensure that pollution does not adversely affect the nature and landscapes of our fresh waters. Examples of this include supporting a number of initiatives to reduce pollution in particular catchments such as Loch Leven, River Dee and Loch Lomond. We are also working with SEPA to raise awareness of the risk diffuse pollution causes in two particularly vulnerable catchments: Loch of Strathbeg in Grampian and the River South Esk in Angus. Scottish Natural Heritage also intends to undertake further work to identify the source of pollution that are currently affecting a number of important lochs that are notified as Sites of Special Scientific Interest.

Airborne pollutants also pose a considerable risk to our fresh waters, and other habitats. To raise awareness of this issue and to help understand its effects, we support the Air Pollution Information Service  .

As pollution can affect different species in different ways, Scottish Natural Heritage has conducted research into the water quality needs of various species including freshwater pearl mussel.