THE Environment Agency has been unable to find a direct source of sewage pollution entering Millbrook Lake despite investigating reports of suspected contamination.

However, the agency has stopped short of ruling out a pollution event, saying it cannot state with absolute certainty the lake has not been polluted.

The findings follow an investigation on September 9 after concerns were raised by residents about discoloured water and suspected sewage entering the lake.

Millbrook Parish Council thanked the Environment Agency for providing its report and residents for continuing to report their concerns.

Investigators inspected South West Water’s mapped surface water outfalls and the permitted combined sewer overflow (CSO), with particular attention given to the black corrugated pipe near Lower Anderton Road.

A sanitary pad was found close to the outfall, but investigators said there were no other typical signs of a chronic sewage problem, such as sewage fungus, sewage-related debris or persistent discolouration.

Water samples taken around the lake also returned negative results for ammonia, which would normally be expected if an active sewage pollution source was present.

The Environment Agency said extensive algal die-off and bleaching had been found around the lake margins and could be contributing to the reported unpleasant appearance and smell.

It also examined video footage showing light-brown water apparently entering the lake from the black pipe.

The agency said this could potentially be sediment-laden surface water runoff caused by soil disturbance from nearby property works, combined with recent rainfall.

South West Water carried out its own checks on August 17 and found the permitted CSO had not been active, while telemetry showed no recorded spills from wastewater assets during the period of concern.

No faults were identified with nearby infrastructure and subsequent site visits found no evidence of sewage pollution.

Despite the findings, the Environment Agency is urging residents to remain vigilant and report further incidents.