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

18 of the world's biggest river systems were covered  in detail during the WATCH programme
Support for sustainable freshwater management in river basins around the world
ECN Moor House in the North Pennines
Long-term multi-parameter monitoring to understand causes and consequences of environmental change
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 collaboration on a wide range of issues related to the freshwater environment - one of Scotland's most precious natural resources
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