UK water companies received more than £340m in revenue last year from industrial and commercial wastewater, according to an investigation that questions how potentially harmful substances are monitored when businesses discharge waste through public sewage infrastructure.
The findings were published on 9 October by the Guardian, working with Watershed Investigations and River Action. The investigation assembled a database of around 26,000 trade-effluent consents to examine which businesses were permitted to send industrial wastewater into treatment works and how those arrangements were supervised.
The research also identified a maximum annual total of up to 608 billion litres under the consents examined. That figure represents a potential volume based on permitted discharges, not a measurement establishing that 608 billion litres actually entered treatment works during the year.
Trade-effluent consents are an established part of the water system. Businesses that produce liquid waste can apply to discharge specified material into public sewers, subject to conditions imposed by the relevant sewerage company. The existence of a consent is not evidence of unlawful disposal.
Under the Water Industry Act 1991, an application is required to describe the nature and composition of proposed discharges, their maximum quantities and flow rates. Water companies can attach conditions addressing those matters and the treatment of particular constituents before the material enters the network.
The investigation nevertheless raises questions about the information available to environmental authorities and the effectiveness of treatment when industrial chemicals enter facilities primarily designed to process domestic sewage. It found no comprehensive central register giving a comparable public view of the individual consents.
The database covers industrial activity ranging from power generation and pharmaceutical manufacturing to food production, hospitals, abattoirs and waste management. The potential pollutants differ by source, making the composition of individual discharges as important as their volume.
According to the investigation, many conventional wastewater treatment works rely on biological processes that are not designed to remove all industrial chemicals. Substances that survive treatment may leave through treated effluent, while others can be retained in sludge subsequently used on agricultural land.
The presence of an industrial chemical in an approved discharge does not establish that it reached a river or farmland at a harmful concentration. The environmental risk depends on the substance, its quantity, the treatment undertaken and the route by which any residual material is disposed of.
Financial records assembled for the investigation put United Utilities’ industrial wastewater revenue at £61.6m and Yorkshire Water’s at £48.8m in the year examined. The researchers cautioned that companies reported tankered waste income differently, limiting direct comparisons between operators.
The largest permitted volumes identified were associated with Thames Water, at 113 billion litres annually, United Utilities at 105 billion litres and Severn Trent Water at 79 billion litres. Those figures describe permissions recorded in the research rather than actual wastewater volumes verified as having passed through the plants.
Wastewater can reach treatment works through sewer connections or be delivered by tanker. The investigation highlighted concerns about tankered industrial waste, including landfill leachate, arriving at facilities such as Davyhulme near Manchester and Avonmouth near Bristol.
Water companies charge businesses for trade-effluent services, making wastewater treatment an established source of commercial revenue. The reported £340m is therefore not itself evidence of unlawful profit, although campaigners argue that financial incentives and insufficient transparency warrant closer scrutiny.
For industrial producers, trade-effluent arrangements are an operational and compliance decision. A consent identifies the conditions under which waste may enter the sewer, but businesses still need reliable information about the material they generate, appropriate controls before discharge and records demonstrating compliance with those conditions.
Waste handlers and utilities also face practical questions about sampling. A limited test can verify some parameters without establishing the absence of every possible contaminant. More demanding checks may be necessary for variable waste streams, particularly where tanker deliveries originate from different industrial processes.
The Environment Agency told the investigators that the framework had been developed more than 30 years earlier, before many concerns about persistent chemicals were well understood. It said work was under way to improve management of contaminants in wastewater.
Water UK argued that English water companies are legally obliged to accept qualifying trade effluent and that the charging framework is regulated. The trade body also called for stronger controls on harmful substances at source and for manufacturers to bear the costs of removing pollution.
United Utilities said it operated consent and monitoring procedures intended to protect public health and the environment, with tankered waste accepted only at designated sites. Those responses form part of the contested assessment of whether existing arrangements provide sufficient protection.
The applicable regulatory responsibilities differ across the UK’s nations. Ofwat oversees economic regulation in England and Wales, while environmental regulation is undertaken by different authorities; Scotland and Northern Ireland have their own arrangements. The investigation’s findings should not be interpreted as a single regulatory determination covering every operator.
The investigation provides a previously unavailable picture of the permissions and revenue associated with industrial wastewater. The next questions concern whether treatment facilities have adequate information about what they receive, how discharge conditions are enforced and whether the public can assess the potential environmental costs of the trade.
You must be logged in to post a comment.