£800,000 fine for water pollution

Passing by

In May 2016 an Environment Agency (EA) employee was walking her dogs near the Row Brook at Acton Burnell, Shrewsbury when she noticed an unpleasant odour. She discovered a ditch full of raw sewage and raised the alarm.

A fat blockage was identified at the inlet of the adjacent sewage treatment plant, and this appeared to be causing the flow to head towards the storm overflow system rather than passing through the normal treatment stream. However, when an EA officer returned to the treatment plant three days later, raw sewage was still being discharged into the brook.

Note. Sewage treatment plants usually have storm tanks which receive excess flow during wet weather. When full, the system will allow liquid to pass through the receiving watercourse. This liquid should be free of solid waste but otherwise untreated. As there is dilution during flood events the risk is small. However, if the storm discharge system is used when water courses are not in high flow, the environmental damage can be significant.

Those responsible for sewage treatment therefore have a duty to ensure that storm tanks are kept empty when not in use, and that they are only used when absolutely necessary.

Permit compliance

A review of flow data indicated that the problems at Acton Burnell were not short term. Between November 2014 and May 2016, Severn Trent Water Ltd (S) had allowed at least 3.8m litres of raw sewage to enter the brook from its site. The prolonged breach of the company’s environmental permit had polluted the brook for 250 metres downstream, negatively impacting its ecology.

It emerged that the expansion of a nearby school meant that the sewage works did not have the capacity to treat all the waste it received, and an upgrade was in the planning stages.

Consequences

As an immediate action, S set up a system to tanker away the excess sewage. By doing this, the EA was satisfied that S was able to run the plant in accordance with its environmental permit.

The company pleaded guilty to three charges including: (1) the illegal discharge; (2) “failing to operate and maintain a grass plot treatment facility” ; and (3)“failing to provide a labelled sampling point” .

It was fined £400,000 on both the first and second charges, with no separate penalty for the third. Additionally, S was ordered to pay £70,420 in costs.

Tip. It was found that S knew of the capacity issue from 2011. If you are operating a sewage treatment plant, regularly review its operational capacity, identify and resolve problems arising, and plan ahead to cope with changes in sewage characteristics or volume, either of which could affect your ability to comply with your permit.

Tip. Contingency plans should be in place to meet the permit requirements in the event of foreseeable problems such as high flow or plant failure.