Corporate Responsibility

Providing sustainable drainage.

We collect and treat sewage from our 15 million customers, using our sewer network to transport it to 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.

In this section of the report, read about how we’re continuing to work hard to make sure our sewerage network and sewage treatment sites are as resilient as possible - to protect our customers, communities and the environment from potential sewer flooding or pollution.

We highlight how we’re proactively maintaining and enhancing our sewer network to reduce the risk of sewer flooding and pollutions, including: installing sewer alarms; regularly cleaning, monitoring and repairing our network; raising awareness of misconnected drains; and communicating and engaging with customers about sewer abuse. Our ‘Bin it, don’t block it’ campaign highlights the dangers of flushing anything other than the three P’s – pee, poo and (toilet) paper – down the drains.

Heavy rain can also overwhelm our sewers, so for us, sustainable drainage means encouraging natural drainage as well as protecting, maintaining and enhancing our sewer network and treatment sites. Find out how, whenever possible, we take advantage of opportunities to deliver more sustainable drainage (SuDS) solutions to increase our sewer capacity and reduce and slow the flow of surface water into our network.

We also focus on our sewage treatment compliance and the “super sewer” designed to help stop sewer overflows and improve water quality in the River Thames by capturing tens of millions of tonnes of sewage every year from the most polluting combined sewer overflows built by the Victorians. You can find out more information on how we’ve been developing an approach for strategic long-term drainage and wastewater management planning in London. This strategy, called London 2100, will tackle a range of challenges including population growth, climate change, land locking of our sites, ageing assets and striving to meet tighter environmental standards.