UK water companies took more than £340m from industrial wastewater they permit and police themselves

In the trade-effluent system, the company that grants a permit is also the company paid to take the waste. Water companies issue and enforce the consents themselves, and environmental regulators have no direct role ^[22]. The companies earn revenue on what flows in ^[1]. An industry expert quoted by the Guardian said the companies had "a financial incentive to accept far more toxic material than they should" ^[14]. The same expert called the permit regime very old and not fit for purpose ^[5]. "Currently the Environment Agency doesn't know exactly how much of this waste is going into waterworks each year," the expert said ^[6].

Checks on arrival are basic. According to an Environment Agency officer, they can involve taking a sample and running a pH test that does not identify most contaminants ^[16]. The officer said that when a sample does turn out to contain something nasty, the waste has already gone by the time that is identified ^[16]. The officer's answer pointed back to whoever made the waste: "They should be seeking sufficient information from the producer of that waste to satisfy themselves so they can treat it properly." ^[17]

That last sentence matters most to the producer. A discharger's current position is sound in law, because water companies are required to take industrial wastewater and issue consents for it ^[2]. The same law lets them refuse applications ^[2]. An Environment Agency officer has now said on the record that "ignorance is no defence" ^[17]. I'd expect water companies to ask producers for more data before they grant a consent. The cost of documenting what goes down the drain would then shift toward the business that makes the effluent.

Scrutiny will not land evenly. Thames Water, United Utilities and Severn Trent together hold 297bn litres of permitted industrial effluent, about 49% of the 608bn litres a year the investigation counted ^[20]. Tankered waste is concentrated too. The officer and the expert both named United Utilities' Davyhulme works in Manchester and Wessex Water's Avonmouth as big receivers ^[19]. "You can see lines of tankers queueing outside Avonmouth," the expert said ^[19]. The officer said landfill leachate was the agency's "greatest concern" ^[15].

The revenue league table does not compare like with like. United Utilities reported the most from industrial waste, £61.6m, and Yorkshire Water £48.8m, but both counted tankered waste that some peers left out ^[4]. With no central register ^[21], a regulator wanting a baseline would have to start from a database built by journalists and a campaign group ^[8].

The pressure for change comes from outside the permit process. Industrial waste adds to the sewer overloading that triggers raw sewage spills ^[23]. Those spills have already drawn outrage, community protests and calls for nationalisation ^[23]. Amy Fairman, head of campaigns at River Action, said: "Industrial pollution must not become a lucrative business for water companies ... Polluters must be held to account and made to pay, rather than passing the costs and consequences down the line." ^[18]

The decision for a discharger this quarter is whether to document its own effluent before a water company asks. Spending now prepares it for stricter consents. Waiting saves money for as long as the current regime holds. The Guardian's report does not describe any government or Environment Agency proposal to change that regime. The longer horizon belongs to the expert, who said the UK needed a dedicated liquid-waste treatment sector to replace a "dilute and disperse" model ^[7].