Question to the Department for Environment, Food and Rural Affairs:

To ask the Secretary of State for Environment, Food and Rural Affairs, what assessment he made on the extent of Sphaerotilus natans in rivers in England.

Sphaerotilus natans is an aquatic periphyton organism associated with polluted water. It forms colonies commonly known as "sewage fungus", but can be associated with different types of organic pollution such as from agriculture or some industrial effluents. The Environment Agency does not have a specific monitoring programme for sewage fungus itself, but it is used as an indicator of pollution when the Environment Agency responds to pollution incidents, and when it carries out wastewater treatment works or storm overflow inspections. If observed the presence of sewage fungus would usually be recorded by monitoring teams when carrying routine ecological and chemical monitoring. The extent of sewage fungus is often used in evidence as an indicator of gross pollution when taking action under the Environment Agency’s enforcement and sanctions policy.