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A Changing Approach to Water Pollution Prosecution


Environmental offences have received large-scale media attention following images of beaches, rivers and lakes visibly polluted by sewerage deposits which has adversely impacted recreation, tourism, local businesses and wildlife habitats. Political pressure has risen, causing the government to look to implement real change within environmental prosecutions.

The government has increased funding for the Environment Agency (EA). Of this increase, £2.2m is to be provided for water company enforcement activity alone. Furthermore, there is to be change in the way fines are utilised by the EA. Funds are now going to be ‘ring-fenced’ for Defra so they can be invested directly back into environmental and water quality improvement projects.

The Environment Agency has urged courts to impose much higher fines for serious and deliberate pollution incidents within the Environmental Performance Assessment (July 2022).

The most recent figures from the Environment Agency show that whilst there has been an overall decrease in the number of environmental prosecutions against water companies, there have been some substantial fines. This suggests that the focus is on prosecuting the more serious offences which incur the higher fines.   

  • In 2017, there was a successful prosecution against Thames Water for six separate cases involving major pollution of water sites over a four-year period. This resulted in a fine of £19.75m.
  • In 2021, Southern Water was prosecuted for a large-scale discharge of untreated sewage across 17 sites over a 6-year period. A fine of £90m was received, which is the largest fine recorded for this type of offence.

The courts have justified imposing such high fines by pointing to culpability, harm and aggravating features. 

The acts must be deliberate to fit into the highest category for culpability. HHJ Sheridan commented in the Thames Water case that the defendant’s conduct was “foreseeable and preventable” and that the company involved had “scant regard for the law”.

Category 1 level harm is defined within the sentencing guidelines as “dangerous” and “widespread” with “major adverse or lasting effects”. The area polluted by Southern Water involved 16–21 billion litres and had a visible impact on beaches, affecting both the public and wildlife alike. This the court found constituted the maximum level of harm and resulted in the largest recorded fine of this nature to date.

Repeat offending is a key aggravating feature in these cases. Thames Water appealed their fine on the grounds that the amount was excessive. The Court of Appeal upheld the fine and emphasised that this was not the first time the company had committed such a breach. Not only did this prosecution itself encompass six separate cases over a four-year period, but Thames Water had received a number of other recent prosecutions for environmental breaches. Johnson J commented that “there is no evidence that the defendant took any notice of the penalties imposed or the court’s remarks”.

What can we expect in the future?

1. Larger civil fines:

The Environment Agency is able to issue variable monetary payments, which are civil fines that are often faster to conclude and more cost-effective than going through the criminal court process. On Monday 3 October 2022, the Environment Secretary announced proposals to increase the limit on civil penalties from £250k to £250m per breach. This is due to be discussed in spring 2023. If the changes are implemented, we may see more civil fines being imposed by the Environment Agency.

2. Criminal prosecutions against individuals

The Environmental Performance Assessment (July 2022) identified that the fines imposed were much lower than the salaries of the chief executives and board members of the water companies. The Environment Agency has called for prison sentences for chief executives and board members whose firms are responsible for the worst pollution. This opinion has been positively echoed by some politicians and media, suggesting we may see more environmental prosecutions against individuals in the future.


Melissa Ingram

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