A DECADE'S worth of sewage and waste water has been running into the River Brent because a pipe was incorrectly connected.
Thames Valley Water was called in to replace a collapsed sewer in Queens Walk, Ealing, but found that a stretch of town houses were not properly connected to the sewerage system when built ten years ago, with waste, washing machine and dishwasher water running into the river.
Sarah Mills, environment management team leader for the Environment Agency, said: "Approximately eight to nine town houses have been found to be misconnected, which Thames Water have advised would have occurred when they were built around the year 2000.
"The waste from these properties was entering the surface water drain, which should carry only uncontaminated rainwater, as they will leave untreated to a local river, stream or soakaway.
"Normally waste pipes from a property are connected to the foul water drains, designed to carry contaminated waste water safely to the sewage works for treatment.
"The pollution from these houses may have caused minor, intermittent pollution to the River Brent but the dilution of the water will have minimised the impact."
Councillor John Popham, representing the Cleveland ward, said: "I am appalled that this error was made in the first place and that it has gone undetected for so long.
"What would have happened if the sewer further down Queens Walk had not collapsed?
"I welcome the fact that the problem is now being sorted out and that sewage is being removed from the Brent - but why did it happen?"
A Thames Water spokes-woman said the property developer would need to be found to foot the bill, adding: "Not connecting properties to our sewers causes serious environmental damage and is completely unacceptable.
"Our sewers are there for a reason - to take sewage to be treated at our sewage works and recycled safely to the environment.
"Taking care of the environment is a top priority for us."
Anyone who spots pollution in rivers should call the environment agency on 80 70 60.