Corporate Responsibility

Providing sustainable drainage.

We collect and treat sewage from our 15 million customers. We use our sewer network to transport this sewage for treatment at one of our 351 sewage treatment works. Wherever possible the solid elements of sewage (what we call sludge) are used to produce renewable energy while the accompanying water is treated to a high standard and recycled safely to rivers and streams.

For us, sustainable drainage means encouraging natural drainage and protecting, maintaining and enhancing our sewer network and treatment sites. We’re continuing to work hard to make sure our sewerage network and treatment sites are as resilient as possible - to protect our customers, communities and the environment from potential sewer flooding or pollution. Whenever possible, we take advantage of opportunities to deliver more sustainable drainage solutions.

Maintaining our network.

Preventing flooding from our sewers is a priority for us. We’re taking a proactive approach by investing in and managing our network more efficiently – including installing sewer alarms and regularly cleaning, monitoring and repairing our network. We’re also working with council environmental health departments and the WaterUK Sewerage Network Abuse Prevention (SNAP) group to reduce sewer abuse by cutting the amount of wet wipes, fat, oil and grease that ends up going down the drain.

Heavy rain can also overwhelm our sewers, so we’ve made significant investment in flooding alleviation schemes, increasing our capacity and installing sustainable drainage systems (SuDS) to reduce and slow the flow of surface water into our pipes. We’ve also developed drainage strategies for areas previously impacted by sewer flooding, and introduced an advanced flood warning system to identify potential areas and reduce any impacts.

Improving London's rivers.

We’ve made really exciting progress with our major engineering schemes designed to help stop sewer overflows and improve water quality in both the River Thames and River Lee.

When they’re completed, the Thames Tideway Tunnel and the Lee Tunnel will capture tens of millions of tonnes of sewage every year from the most polluting combined sewer overflows built by the Victorians.