Brussels demands fines over London and Whitburn sewage
Britain faces large fines for breaching European Union law on water treatment after plants in London and north east England dumped raw sewage into waterways.
The European Court of Justice has the power to impose fines of thousands of euros per day, but has yet to decide what the fine will be.
Under a 1991 EU law, Britain was obliged to meet new standards for treating waste water.
The court said it has not.
"The United Kingdom has failed to fulfil its obligations under (the) directive," the Luxembourg-based court said.
It said plants in Whitburn in Wearside and in London had dumped sewage in local waterways.
London's sewer system, much of which dates back to Victorian times, discharges raw waste into the River Thames when rainfall overwhelms the 19th-Century tunnels.
"So far as concerns the treatment plants of the collecting system for London... their capacity is sufficient in dry weather but not sufficient in the slightest in the case of rainfall," the court said.
Britain said it had already taken steps to fix the problem and that it was complying with EU regulations.
The court rejected its argument.
"A member state may not plead practical or administrative difficulties in order to justify non-compliance with the obligations and time limits laid down by a directive.
"The same holds true of financial difficulties, which it is for the member states to overcome by adopting appropriate measures," it said.
A Defra spokesman said the department was "disappointed" by the court's findings as it is working on "major improvements to sewage and treatment systems in London".
He added: "We will study the judgement carefully to ensure we solve all of the breaches."
A £4bn tunnel dubbed the "super-sewer" has been commissioned in London, underneath the Thames, in an attempt to solve the capacity problem.
In 2010, the European Commission asked the European Court of Justice to impose a lump sum fine of 15 million euros on Belgium for water violations, and a daily fine of 62,000 euros.