There are three main sources of pollution going into the River:
1. Sewage – which accounts for about 1/3rd
2. Agricultural – which accounts for about 2/3rds
3. Road Runoff
The commonest effect of pollution from human and animal excrement is that growth of algae, often visible as a green covering on the surface of the water. This blocks sunlight from reaching through the water, which depresses all life forms. More intense pollution can cause depletion of oxygen levels which can cause fish die-offs.
River Guardians can help water quality by carrying out simple Testing.
If you find evidence of a pollution incident, it can be reported to the Environment Agency (EA) on their hotline number, 0800 807060. Do follow the case up with the EA, because there is often a revolving door relationship between the EA and polluters, and their record of firm action often leaves much to be desired.