PARLIAMENTARY WRITTEN QUESTION
River Wandle: Sewage (26 October 2022)

The Environment Agency (EA) carries out regular ecological monitoring into the health of river ecosystems focussing on parameters including, aquatic invertebrates and plant communities, fish populations, and habitats. Examination of routine physico-chemical monitoring data for points on the River Wandle from 2010 to present day shows no significant decline in water quality, using the measures most often associated with sewage pollution (ammonia and dissolved oxygen). Data is collected monthly. The River Wandle is assessed as being at moderate ecological status under the Water Framework Directive.

Data obtained from invertebrate monitoring programmes provides the most relevant evidence of any ecological impacts from sewage inputs. The EA currently monitors two sites on the river Wandle. Data from these sites since 2000 has shown no evidence of any deterioration in ecological health.