On 21 December 2018, Oxford Crown Court fined Thames Water £2 million following pollution of raw sewage into Oxfordshire steams.

The facts

The court heard that numerous management failings by Thames Water in their operation of a sewage pumping station had caused sewage from two villages to pollute two brooks at Milton-under-Wychwood, near Chipping Norton for up to 24 hours. On 8 and 9 August 2015, Idbury and Littlestock brooks, which lead into the River Evenlode, a tributary of the River Thames, were polluted by raw sewage. A backlog of raw sewage was forced into the water from a sewer pipe that was unable to hold it. Sewage also escaped from a manhole and flooded a residential front garden.

Environment Agency (EA) officers attended the incident and discovered that along a 50-metre stretch of water, all of the local population of nearly 150 bullhead fish had been killed. A member of the public also reported to the EA that there were dead fish in Idbury brook.

The court was told that in the six weeks prior to the incident, Thames Water had ignored over 800 high-priority alarms, which would have alerted staff to faults with the system and which required attention within a four-hour period. The company also failed to adequately investigate a further 300 alarms, all of which would have highlighted the problems with the pumping station. One alarm was deliberately deactivated during a night shift. The company had also allowed the sewage pumping station to operate with no automatically available standby pump for around 10 months in the year prior to the pollution.

Following investigation by the EA, it was found that Thames Water was aware that the pumping station had failed several times in the 12 months up to and including the incident in August 2015. These failures were neither addressed nor reported to the EA.

The decision

At an earlier hearing, the company pleaded guilty to breaching Regulation 12(1) (b) and 38(1) (a) of the Environmental Permitting (England and Wales) Regulations 2016.

Judge Peter Ross ruled that the incident amounted to a high-end, category three harm offence. He considered that Thames Water was “reckless” in its management and fined the company £2 million. However, the judge agreed to reduce the fine by £200,000 if the water company donated £200,000 to three local environmental charities within 56 days. He also ordered Thames Water to pay the full legal costs of £79,991.57.

In defence, Kerim Fuad QC told the court that Thames Water had invested £40 million in improving wastewater sites. He said that the company, which has an annual turnover of £2 billion, operates more than 4700 pumping stations and that there had not been an incident at the Milton-under-Wychwood site since 1993. He said:

“Any loss of fish or damage to the environment short or long term is extremely regrettable but the cause of this unfortunate event in many respects remains unknown.”

However, the judge rejected this argument. He said that the number of pumping sites was “irrelevant”, as the risk of pollution needed to be managed at each site, regardless of how many there were. He commented that:

It’s that failure to integrate the technological advances with human assessment, analysis and response which lies at the heart of the deficiencies that were created in this case.

In order to be operated effectively there had to be a proper integration of the technology and human resources, adequate training for the latter and a culture ensures that the exercise of judgment is still undertaken by human beings.

The judge considered that this culture led to the high number of alarms being ignored as a fault with the alarm system and not the pump system. Consequently, he considered that more effective management and training and the establishment of a proper culture would have prevented the incident, although he accepted improvements had been made since.

After the hearing, Robert Davis, who led the investigation for the EA, said:

This incident was foreseeable and avoidable. Thames Water didn’t recognise the increased risk to the environment, ignoring or failing to respond adequately to more than 1000 alarms.

These streams are normally a haven for kingfishers, grey herons, brown trout and other fish and invertebrates. Sewage poured into the water for 24 hours, having a terrible impact, killing fish and other water life.

We hope this prosecution sends a loud and clear message that the Environment Agency will not accept poor operation, management and maintenance of sewage pumping stations. Where we have evidence of offending and serious pollution incidents like here, we will take appropriate action to bring polluters to justice.


This is the latest large fine for the water company, following the record £20.3 million fine they received in 2017 for allowing 1.9 billion litres of sewage to be pumped into the River Thames. Indeed, Judge Ross noted the similarities between the failures in this case and the previous incident. He said:

Had lessons really been learned and implemented from the events in relation to the two previous convictions then this would not have happened.

It is a seriously aggravating feature in this case that the defendant allowed such management and cultural failings to continue to persist within the organisation.

While the size of the fine reflects both the seriousness of the harm caused and the large turnover of the company, the final point is noteworthy for all firms involved in potentially polluting activities. A “seriously aggravating feature” was the company’s failure to correct its management practices. The direct cause of the incident may be unclear, however the judge was concerned by the continuity of failings amid the general culture of the firm. It was that culture — which is irrespective to size of the firm — which was the driving factor behind the level of fine, and it is a lesson all firms should take note of.

Last reviewed 4 February 2019