Thames Water has been fined £2.3 million after a stream was polluted by sewage.
A court heard failure to address equipment faults at a sewage-treatment plant in Oxfordshire made the incident “entirely foreseeable”.
Sewage with high levels of ammonia was released into Fawley Court Ditch at Henley-on-Thames in 2016, killing 1,144 fish and other water life.
Poor management at the plant was laid bare at Aylesbury Crown Court. Thames Water’s treatment works at Henley had no adequate monitoring in place to manage the risk of pollution, made worse by staff not responding to alarms highlighting faults in the process.
Judge Francis Sheridan said Thames Water should have reacted to the warnings “long before” they did. He added the pollution and the events leading up to it showed “high negligence” by the company.
The first Environment Agency officer on site on 23 April 2016 could smell the sewage in the brown water. Another witness reported a number of dead fish and sanitary products in the stream, near to where the pollution occurred.
The Environment Agency’s investigation showed ammonia levels in Fawley Court Ditch were, at worst, double the permitted limits.
Fish from 13 species died, including chub, gudgeon, dace, roach, perch, tench and pike. The stream took almost a year to recover, having lost almost all its fish to the pollution.
The court was told a number of faults at the plant had a significant effect on sewage treatment.
Machines to aerate effluent and reduce ammonia totals weren’t working. Probes measuring the standard of the treatment process were also out of order.
Officers found oxygen at the plant that helps control the treatment dangerously low 24 hours before the incident.
Alarms warning of problems were given a delayed response or none at all. Part of the sewage treatment process wasn’t even monitored in the week prior to the pollution.
Jackie Outhwaite, a land and water officer for the Environment Agency, led the investigation:
Thames Water could and should have prevented this pollution through better management of sewage-treatment.
Our investigation found the risk of pollution was increased by a lack of measures in place to prevent it. Thames Water’s failure to respond to warning alarms ultimately led to significant harm on water quality.
The Environment Agency’s enforcement action over several years and the pressure it has put on water companies has led to £30 billion of investment by the industry in water quality. The damage caused to the environment at Henley, however, shows water companies have a lot more to do to protect the environment.
Sitting at Aylesbury Crown Court on 26 February 2021, Judge Francis Sheridan fined Thames Water £2.3 million, ordering them to pay the Environment Agency’s costs of £87,944.
Thames Water pleaded guilty to one count of causing a discharge of partially-treated effluent into Fawley Court Ditch and Fawley Court Stream without an environmental permit between 21 and 24 April 2016. It was charged under regulation 12 (1) (b) of the Environmental Permitting (England & Wales) Regulations 2010.
This latest conviction brings the total amount of fines levied against Thames Water since 2017 to £24.4 million for 9 cases of water pollution across Oxfordshire, Berkshire and Buckinghamshire.