Water quality refers to the biological, chemical and physical makeup of the water. There are always natural changes in water quality, but industrialisation, population growth, climate change and land-use change have meant more pollutants are entering water systems than ever before. These pollutants alter entire ecosystems and present a danger to human health.

This pollution can be very sudden and dramatic - the BP oil spill made headlines for months. Other pollution, however, is sometimes harder to spot. Nitrogen and phosphorous, for example, quietly enter the environment as by-products of industrial processes. The resulting nutrient-rich water system can actually be harmful for aquatic life, with algae using up all the oxygen and creating ‘dead zones’.  

There is also the financial cost and the toll on human health. Nitrogen pollution alone costs Europe an estimated £60-280 billion per year, and about 10 million Europeans drink water with unsafe levels of nitrate.

CEH work on water quality


Monitoring sites

Research facilities

Pair of arctic charr
Process-based understanding of how lakes function, generating knowledge for lake managers
CEH scientists carrying out restoration research at a lake in Scotland
CEH scientists will present at the Meeting in Granada, Spain
An algal bloom and boats
Projects to improve the quality of water bodies for drinking water and recreational use
Analytical chemistry laboratory at Wallingford
Providing high quality chemistry data for the Thames Initiative Project
Scottish Freshwater Group logo
Promoting awareness of current issues and research related to the freshwater environment in Scotland
PROTECH model graph
Assesses phytoplankton for lake management
Cows by Esthwaite Water
International lakes research (March 2014 e-conference)
Soil water measurement
Simulates the resulting reactions of metals entering water and soil systems
Pair of arctic charr
Identifying causes of the decline of Arctic charr
Scientist photographing algae on Loch Flemington
Managing regime shifts in a shallow eutrophic lake
Algal bloom in Esthwaite Water
Lake remediation by top-down and bottom-up management
Coldingham Loch
Managing cyanobacterial blooms by aeration