How much raw sewage is released into rivers and the sea, and what are the rules?
Water companies in England released unprecedented amounts of raw sewage into the sea and rivers. While firms are allowed to discharge limited sewage during heavy rainfall, there is increasing evidence of “dry spills” that can harm the environment and pose health risks to swimmers.
Scale of Sewage Releases
The volume of sewage spills by water companies into England’s rivers and seas more than doubled in 2023. The Environment Agency reported 3.6 million hours of spills, up from 1.75 million hours in 2022. Water UK, the industry body, acknowledged this as “unacceptable” but attributed the spike to heavy rain and improved data collection. However, the Environment Agency emphasized that increased rainfall does not absolve companies from their legal responsibilities to manage storm overflows.
Causes of Sewage Discharges
The UK’s combined sewerage system carries both rainwater and wastewater in the same pipes, directing them to treatment works. During heavy rain, the system can overflow, discharging excess wastewater into natural water bodies through combined sewer overflows (CSOs). However, evidence indicates that some water companies also spill sewage in dry weather, which is illegal and results in undiluted waste entering waterways. A BBC investigation identified 388 potential “dry spills” in 2022 by Thames, Wessex, and Southern Water.
Government and Industry Responses
In April 2023, the government announced a plan to enhance water quality, proposing unlimited fines for polluters. Penalties from water companies are intended to be reinvested into a new Water Restoration Fund. Then-Environment Secretary Therese Coffey noted the complexity of stopping pollution overnight due to the extensive changes needed in the water system. Water UK has pledged nearly double the current spending to upgrade infrastructure and reduce discharges, which may lead to a £156 annual increase in customer bills.
Health Risks of Polluted Water
In May 2024, UK engineers and scientists warned of the health risks from human faeces in rivers, urging more frequent testing. Exposure to bacteria such as salmonella and E.coli, and viruses like hepatitis A, can cause serious health issues. Additionally, thousands of Devon residents were advised to drink bottled water after their supply was contaminated with the cryptosporidium parasite, potentially due to a faulty valve on private land.
Checking Water Quality
The Environment Agency monitors water quality at bathing sites weekly from May to September and provides daily pollution risk forecasts in some areas. Their website offers searchable water quality data. Campaign group Surfers Against Sewage also provides an interactive map with broader pollution risk warnings.
Overall Water Quality
Routine monitoring of sewage spills has only recently begun, making long-term trends hard to establish. However, overall water quality, including other pollution sources, has been tracked for decades. In May 2023, the Environment Agency reported that 16% of assessed surface waters in England achieved “good” ecological status, with significant disparities across different types of water bodies and regions.
Impact of Brexit on Water Quality
Post-Brexit, three French MEPs requested the European Commission to intervene against UK pollution in the Channel and North Sea, alleging a decline in standards. While the UK’s Environment Act 2021, which replaced EU laws, introduced measures to reduce sewage discharges, it remains to be seen how effective these will be in improving water quality.
