A water company whose careless operational practices decimated the aquatic life in an iconic urban river has today, Monday 26 January, been fined £125,000 and ordered to pay £21,335 in clean up and investigation costs.

Thames Water Utilities Limited, Britain’s largest water company, pleaded guilty at an earlier hearing to allowing a large quantity of industrial strength chlorine to spill into the River Wandle from its Beddington Sewage Treatment Works near Mitcham, South London in September 2007.

It took three days for Environment Agency officers, helped by members of the Wandle Trust and local angling clubs, to remove some two tonnes of dead fish from the river. An experienced Environment Agency officer at the scene said that it was the worst pollution incident he had ever dealt with.

Croydon Crown Court heard that on 17 September 2007 Environment Agency officers received reports from local residents and anglers of hundreds of dead and distressed fish in the River Wandle in the Mitcham area. The residents also reported a strong smell of chlorine, and the water turning a milky colour. Local people along the river attempted to rescue some of the distressed fish by transferring them from the river into buckets of clean water, but they were too late. One local man rescued a large number of eels, but found they were bleeding from the gills and they all later died.   

The pollution spread downstream for nearly 5km and had a catastrophic impact, killing the majority of the fish in the river, including chub, roach, dace, gudgeon, barbel and eel. It also bleached and killed much of the normally green vegetation that grows along the channel bed. It affected the Wandle’s highly valued recreational areas such as Poulter Park, Ravensbury Park and the National Trust site at Morden Hall Park.

The River Wandle is a well known chalk stream and tributary of the River Thames that flows through parts of Mitcham, Morden, Wimbledon and Wandsworth in South West London, cutting a green swathe through these heavily urbanised areas. Historically the river has suffered extreme pollution and was officially declared a sewer in the 1960s. But over the last 20 years it has become a vibrant rich habitat due to better environmental regulation, a fish stocking programme and huge local enthusiasm for the river which has resulted in a vast improvement of water quality.

Before the pollution in 2007 the Wandle had become well known as one of the best urban coarse fisheries in the country which supports wide a variety of species. It could take up to 10 years for the river to fully recover and the fish stocks to return to pre- incident standards.

Handing down the fine at Croydon Crown Court Ms Recorder Wickham described the incident as “A 5km tragedy for the River Wandle”.

Environment Officer Peter Ehmann – who was one of the first on the scene, said: “This pollution effectively wiped out 20 years of painstaking restoration work on the River Wandle. For many years individuals and organisations, including the Environment Agency and the Wandle Trust, have achieved great improvements to water quality and aquatic life in the Wandle. This incident is a major set back to all their hard work.”

A Thames Water Utilities Director was formally interviewed by Environment Agency officers on the 28 November 2007 and confirmed that sodium hypochlorite (chlorine) was released from Beddington Sewage Treatment Works during a cleaning operation of the tertiary treatment plant.

A Thames Water scientist on site noticed the strong smell of chlorine in the outlet channel and instructed the staff cleaning the plant to stop their work, before informing the site manager. The site manager decided that ‘very limited damage’ would occur to the environment and they would deal with the incident internally. The Environment Agency was not informed. It was not until members of the public reported the incident to Thames Water more than an hour and a quarter later that they realised the severity of the pollution.

After the sentencing Mr Ehmann said: “We are pleased that the court has recognised the gravity of this incident and hope that other operators to ensure they have appropriate procedures in place to better protect their local environment and community.”

Ed Mitchell, Head of Environmental Protection regulation at the Environment Agency said: “A pollution incident of this size and nature is rare now due to tighter and more effective environmental legislation, regulation and greater public awareness of the environment. However, we still take rigorous enforcement action against any company polluting the environment, no matter how large or small the scale of the incident.  We successfully prosecuted 176 companies in 2008, totaling over £2 million in fines. We successfully prosecuted 209 individuals; including 19 company directors.”

“The Environment Agency is putting pressure on water companies in England and Wales to invest more in maintenance to improve the environment and reduce the risk of pollution incidents. In 2007, water companies were responsible for one fifth of all serious pollution incidents – many of which were caused by poorly maintained, overloaded or ageing sewerage infrastructure.”

In sentencing Thames Water the Court took into account the company’s early guilty plea and its work with the Environment Agency on the River Wandle since the incident.

Thames Water Utilities Ltd appeared at Sutton Magistrates’ Court on Thursday 4th December 2008 and pleaded guilty to a single count of causing polluting matter, namely sodium hypochlorite, to enter controlled waters on 17th September 2007 contrary to sections 85(1) and 85(6) of the Water Resources Act 1991. The sodium hypochlorite entered the Beddington Main Effluent Carrier (MEC) from the Defendant’s Beddington Sewage Treatment Works (STW) before entering the River Wandle, a tributary of the River Thames.

Thames Water reported an annual turnover in 2008 of £165.818million. The fine imposed represents less than 0.1% of the company’s annual turnover. 

Thames Water has been prosecuted on many occasions by the Environment Agency, although there have been no pollution incidents from Beddington Sewage Works which have previously resulted in prosecution. However, the company does have several previous convictions, which arose from accidents involving chemicals at other sewage works.

The river Wandle supports a great variety of wildlife including chub, barbel and eel, it is also a very popular location for walkers. The popularity of the River Wandle has seen groups such as the Wandle Trust set up, whose purpose is to preserve the wildlife and habitat that it supports.    

Significant Environment Agency resources were deployed in the investigation and the cleanup of the incident. At the height of the incident 11 environment officers were on site.

Since the incident, Thames Water has pledged £500,000 over a five year period to support local environmental improvements and has paid compensation to local angling clubs of around £10,000.