Yorkshire Water fined for illegally discharging sewage

The Environment Agency has successfully prosecuted Yorkshire Water for illegally discharging sewage effluent into the Potter Carr Nature Reserve in Doncaster, in March 2017.

On 8 September 2021, at Sheffield Magistrates Court before District Judge Redhouse, the company was fined £150,000 and ordered to pay £36,506 costs.

It pleaded guilty to two charges at an earlier hearing; causing sewage sludge to enter a tributary of the Mother Drain and breach of permit condition relating to ammoniacal nitrogen levels in its final treated sewage effluent.

Representing the Environment Agency, Rebecca Chalkley told the court Yorkshire Water holds an environmental permit that authorises water discharges from Balby Sewage Treatment Works (STW) under a number of strict conditions.

On March 28 2017, Yorkshire Wildlife Trust reported that Mother Drain at the Potteric Carr Nature Reserve, which is a site of Special Scientific Interest (SSSI), had become discoloured and smelt of chemicals.

Environment Agency officials confirmed pollution of the Mother Drain. They saw small pieces of toilet paper floating in the water and sample results confirmed high levels of ammoniacal nitrogen in the water.

Due to the severity of the pollution the Environment Agency requested the Internal Drainage Board (IDB) to switch off a pump station, used for land drainage, to prevent polluted water passing downstream to the River Torne and they instructed abstractors to cease abstracting water. This included Doncaster Golf Club.

Once the Environment Agency contacted Yorkshire Water, it confirmed there was an issue at Balby Sewage Treatment Works.

Officers attended Balby Sewage Treatment Works on March 29 2017 and took a sample of treated sewage effluent which contained ammoniacal nitrogen above the permitted maximum limit.

During the site visit, Yorkshire Water explained a valve failure had led to a settlement tank on site draining sewage sludge inside a building and onto surrounding ground.

Later, the company explained the valve failure happened on Monday 27 March 2017 and it did not contact the Environment Agency because it thought effluent was contained on site.

The company further added electrical damage caused by the incident affected parts of the works and disrupted the biological treatment processes which resulted in a deterioration of the treated sewage effluent quality.

In response, Yorkshire Water placed aeration equipment in the Mother Drain, and the Environment Agency continued to investigate and monitor the effects of the pollution for over a week.

In court, District Judge Redhouse found the culpability of the utility company to be “high negligent” due to the fact the incident could have been avoided if there had been a drain survey at the site and if the valves had been checked.

An Environment Agency spokesman said: “Water companies are aware their activities have the potential for serious environmental impacts, and they know we will take appropriate action when they cause pollution.

“In this case Yorkshire Water has failed the environment, customers and the system of environmental laws the public puts its trust in.

“Polluters must pay, the Environment Agency will continue to do everything in its power to ensure that they do.”

A Yorkshire Water spokesman said: “In March 2017, a valve at our Balby sewage works failed and caused the site to flood.

“Unfortunately, this caused wastewater to discharge into Mother Drain. We commenced an immediate investigation into the matter and a clean-up operation of all affected areas.

“We, working closely with the Environment Agency, monitored the water quality so we could put the correct mitigation in place to protect the environment and worked with local stakeholders to mitigate and minimise any impact on them.

“We take our responsibility to look after the environment very seriously and are sorry this incident occurred.

“As the judge sentencing in this matter recognised, we have taken learnings on board and following the incident invested over £640,000 at Balby to upgrade the site and prevent this from happening again.”