Water quality and pollution management in the UK

Polluted or low-quality water reduces the amount available for use. This increases pressure on water resources, especially in areas where demand exceeds supply (water deficiency).

Although the quality of river water in the UK has increased significantly over time, there was a decrease in the overall number of water bodies awarded high or good surface water status between 2011 and 2016.  In 2011, 37% of surface water bodies were assessed under the Water Framework Directive (WFD) in the UK as being in high or good status, falling to 35% in 2016; the indicator is therefore assessed as declining in the short term.

Status classification of UK surface water bodies under the Water Framework Directive, 2009 to 2016. Source – DEFRA – http://jncc.defra.gov.uk/page-4250

The main reasons for this are:

• chemicals used in fertilisers on farms, such as nitrates and phosphates, are being washed into rivers and groundwater;
• pollution from vehicles enters water sources as the result of run-off when it rains;
• chemical and oil spills from factories pollute local water sources and groundwater;
• sewerage waste can also enter water bodies;
• water running through old mine workings and old industrial sites can pick up hazardous heavy metals. This is known as historical waste.

Nearly 50% of the groundwater used for public supply in the UK is affected by pollution. This has led to many sources being closed or has had to undergo expensive treatment to make them safe for public consumption.

Effects of Water Pollution in the UK

Water pollution has both environmental and social impacts:

• Pesticides are detrimental to aquatic wildlife.
• Fertilisers accelerate algae growth, causing eutrophication. This leads to a reduction in oxygen, adversely affecting wildlife.
• Elevated water temperatures can be fatal to aquatic life.
• Toxic waste contaminates wildlife, which may be passed on to humans consuming tainted shellfish or fish. This can result in birth defects and potentially cancer.
• Drinking water sources can become contaminated.
• Microbacteria in sewage propagate infectious diseases among aquatic life and humans. • Fishermen and the tourist sector, reliant on pristine water, face economic hardships.

Managing Water Quality and Pollution Levels in the UK

There is a range of strategies in place to support improving quality. This includes introducing regulations on the amount and type of pesticides and fertilisers that can be used. Also, drainage systems are improved to slow the movement of rainwater so that pollution can be broken down in the soil.

• UK legislation sets boundaries on the quantity and type of discharge from factories and farms into rivers. • Educational campaigns raise public awareness about proper disposal practices in sewage systems.
• Wastewater treatment facilities remove solid waste, bacteria, algae, and chemicals, rendering water safe for consumption.
• Investments in sewers and water mains help mitigate sewer overflows, spills, and accidents.
• Pollution traps, like reed beds, intercept and filter pollutants.
• Green roofs on buildings help purify rainwater, mitigate flooding, and combat climate change by absorbing carbon dioxide (CO2) from the atmosphere.