Unbiased evaluation has estimated that greater than half of Thames Water’s 351 sewage therapy works are at the moment working with out adequate capability to deal with the volumes of sewage they obtain.
Analysis carried out by the volunteer-led Oxford Rivers Enchancment Marketing campaign (ORIC) has recognized 181 therapy works falling wanting required capability. Of those, 94 have between 80–100% of the mandatory therapy capability, 70 function between 60–80%, and an alarming 17 websites perform at lower than 60%. In some circumstances, akin to Hanwell and Bourton-on-the-Water in Oxfordshire, amenities are estimated to be treating lower than half the sewage they obtain.
An absence of therapy capability results in untreated sewage discharges (storm overflows) taking place extra ceaselessly. A lot of the worst-performing works are discovered exterior of London in headwater streams and tributaries of the River Thames, the place uncooked or partially handled sewage is prone to be extra dangerous to the river ecosystem, as small waterbodies can’t dilute pollution successfully.
This seemingly complete analysis, spanning over two years, was based mostly on information secured through Environmental Data Requests from Thames Water and cross-referenced with inhabitants figures. Required therapy capacities had been calculated utilizing a strategy accepted by the Atmosphere Company. While not formally accepted by the regulators, these figures nonetheless give a sign of areas the place sewage works are dealing with capability points.
The findings at the moment are publicly accessible by means of a brand new interactive map on the Oxford Rivers Mission Portal. Environmental charity Thames21 has helped to develop the Oxford Rivers Mission Portal with its companions.
Commenting on the Oxford Rivers Enchancment Marketing campaign’s report, John Bryden, Head of Bettering Rivers at Thames21 and Regional Improvement Supervisor at The Rivers Belief, stated: “Thames Water’s underperforming sewage works should be upgraded to satisfy fashionable regulatory necessities — the place housing development is deliberate, upgrades to sewage works are wanted earlier than the event is constructed.
“Swift motion is required, notably in headwater streams. This could occur by means of a mixture of conventional gray options, like constructing larger therapy tanks, and lining sewers, and inexperienced options akin to sustainable drainage methods and therapy wetlands. By making this information public, we intention to empower communities, environmental teams, and native authorities to name for fast infrastructure upgrades.”
The publication of this map comes shortly after a significant Ofwat investigation, which discovered that in 2021 Thames Water breached environmental allow situations at 157 websites and was fined £104.5 million for failures to keep up and improve its belongings appropriately.
ORIC co-founder Mark Hull stated: “It’s astonishing that Thames Water seem to not know the therapy capability of 120 of their sewage works. It’s much more astonishing that of the remaining 181 works, over three quarters have tanks and pipes which might be too small to deal with all of the sewage arriving when it rains.
“This has precipitated a rising tide of uncooked sewage discharges into the River Thames over the six years since computerized monitoring. In 2020, 22 works discharged uncooked sewage for greater than 38 hours every week (a working week) however that determine had virtually doubled by 2024. In the meantime, the entire hours spent discharging uncooked sewage from these works with insufficient capability greater than doubled to 120,000 hours final 12 months.”
Tessa Fayers, Thames Water’s Waste and Bioresources Director, stated: “We all know how a lot individuals get pleasure from and respect rivers, which is why over the subsequent 5 years we’ll ship a file quantity of funding to deal with our ageing infrastructure and meet the calls for that include inhabitants development and local weather change.
“We’re dedicated to seeing waterways thrive, however we are able to’t do it alone. Farming, business, highway runoff, wildlife and more and more excessive climate additionally play a job in river well being. We consider that each one storm discharges to the surroundings, even when permitted, are unacceptable, nonetheless, it’s essential to do not forget that they system was traditionally designed on this strategy to stop sewage backing up into properties. This is a matter that can take a few years and important funding to resolve and is on the coronary heart of our Storm Overflow Motion Plan.
“Transparency is on the coronary heart of what we do, and we had been the primary water firm to publish an actual time information map on our web site displaying all storm overflows, earlier than it grew to become authorized requirement to take action.”
The map of all sewage works might be accessed, and the total dataset downloaded at https://oxfordrivers.ceh.ac.uk/information/casestudy-tw-stc.
