case study - muck spreading
Ref: W02b

Muck spreading

On an ordinary day in Spring 2002, many farmers in a river catchment were spreading farm-yard manure and slurry on their fields. They were not doing anything wrong, but unfortunately a sudden turn in the weather helped cause a pollution incident.

There was an unexpected storm and a very intense rainfall, which had not been forecast. The rain washed all the newly spread manure off the dry land and into the river. In manure there is a chemical called Ammonia, this was released into the river, as a result the amount of oxygen in the river fell. Oxygen is very important for the survival of fish and other water dwelling animals; a decrease in oxygen levels is bad for their survival.

Fish in a clean river

The Environment Agency pumped the worst of the polluted water on to the land. Floating booms were used to stop manure floating farther down stream. The chemical hydrogen peroxide was also used to cope with the high oxygen demand of the polluted water. Visit the Environment Agency’s website for more information about how pollution in rivers is dealt with.

Fish that were suffering from the reduction in oxygen levels were taken out of the polluted parts of the river and moved to the unpolluted tributaries nearby.