A water firm has been hit with a record breaking £1million fine after toxic sewage waste swamped part of the Grand Union Canal.
Sewage effluent from the Thames Valley treatment works at Tring leaked into the Wendover Arm of the canal over a nine month period from July 2012 and April 2013.
The waste had overflowed into the canal after poorly performing sewage inlet screens at the plant became blocked with wipes and other non-flushable items that people had put down their toilets.
This led to sewage debris and sewage sludge being discharged into the canal.
The Environment Agency received complaints from the Canal and Rivers Trust and from the general public about the pollution and, when officers visited the site, they discovered sewage debris including panty liners and ear buds.
On one occasion officers worked with Thames Water, to arrange for aeration to be installed at the outfall into the Grand Union Canal, as a precautionary measure to increase the levels of oxygen in the water to protect plant and fish life.
In May last year, the water firm pleaded guilty to two charges under the Environment Permitting Regulations 2010 and, on Monday at St Albans Crown Court, the firm was fined and ordered to pay prosecution cots of £18,113 and a victim surcharge of £120.
The £1million fine is the highest ever penalty for a water company in a prosecution brought by the Environment Agency.
Speaking following the court hearing a spokesman for Thames Water said: “We take our responsibilities to the environment extremely seriously and very much regret this incident. We have since invested heavily in Tring sewage works to further improve resilience and protect the Grand Union Canal.
“We have also reviewed our procedures to reduce the chance of anything like this happening again, including upgrades to the inlet screens which were the cause of the pollution when they became blocked with wipes and other non-flushable items.”
The Wendover Arm, which is 6.7 miles long and opened in 1799, was originally designed to supply water to the summit level of the Grand Junction Canal but it has been unnavigable since 1897. It is currently being reconstructed by charity group the Wendover Arm Trust and phase one of the project - the first 1.3miles from the junction at Bulbourne - was completed and reopened in 2005.
Thames Water has a permit to discharge treated effluent from the Tring Sewage Treatment Works into the Wendover Arm but conditions of the Environment Permit, set by the Environment Agency, aim to prevent any negative impact upon the canal itself and activities such as boating and fishing.
Environment Agency officer Emily Rowland said: “We welcome the court’s decision to penalise Thames Water for serious breaches of its Environmental Permit, which led to pollution of the Grand Union Canal. We take these types of incidents very seriously and will do everything within our powers to safeguard the environment and people affected, and that includes holding to account those whose actions put the environment at risk”.
Partially treated sewage can contain polluting matter such as suspended solids, high levels of iron and aluminium.
Suspended solids have the potential to smother organisms and plant life in rivers and cover the spawning grounds of fish, while aluminium and iron can have toxic impacts on macro-invertebrates.
Routine samples of the discharge at the Wendover Arm taken on 31 January 2013 contained high levels of iron and aluminium, and showed a high chemical oxygen demand.
Thames Water told the court that since the incidents it had spent £30,000 on replacing the inlet screens at Tring. It company co-operated with the Environment Agency in its investigation and has taken steps to avoid further incidents.