Rising pollution levels at Ewell Court Lake prompted the ‘dynamic duo’ to survey the 2,600 homes connected to the drains that take rainwater away from houses straight to the wildlife haven.
The investigation successfully identified a number of homes had mistakenly connected toilets and washing machines to surface water drains, instead of the sewer network.
These misconnected appliances were sending wastewater straight into the lake instead of the sewers, where it follows a different route to the local sewage treatment works.
Through a range of investigative methods, including household surveys, CCTV surveys and placing orange dye into toilets to trace where it flushes, Thames Water found 55 appliances in the area were wrongly installed, four of which were toilets.
Jasmine Killen, from Thames Water’s environment team, said:
“The thought of human waste, cooking fat and dirty water going straight into a lake at this beauty spot is frankly disgusting, so we’re really pleased our work here has paid off and we’ve tracked down those homes with misconnected drains.
“We’ve got a massive job still to do to trace more of these misconnections across our patch – so it’s really important that anyone having extensions built or carrying out plumbing work employs a reputable plumber and knows exactly where their wastewater is heading.”
Stephanie Ilsley, environment officer at the Environment Agency, added:
“The Environment Agency is really pleased that Thames Water’s hard work has helped clean up the flow of polluted water to the lake. Sewage and fats were regularly discharging into the watercourse and reducing the water quality for the wildlife and creating an unpleasant environment for visitors to the lake.
“To ensure that this doesn’t happen again in the future we encourage homeowners to check that they are connected right – you can find information on how to do this on the ConnectRight website.”
In the Thames Water region, plumbing mistakes result in up to one in 10 households misconnecting their waste appliances to the surface water system and in some parts of London this is as many as one in three homes.
This is the equivalent of almost two Olympic-size swimming pools of wastewater wrongly entering the region’s rivers and streams every day. The Thames Water misconnections team work in close partnership with the Environment Agency and local authorities to trace and reduce the number of misconnections, but it is predicted that there are at least another 60,000 misconnections still to be found.
