Edinburgh Sheriff Court heard that on 18 December 2019 the Belhaven Brewery Company Ltd had discharged approximately 8,000 litres of undiluted caustic solution into the public sewer when an automatic cleaning process went wrong.

The discharge of concentrated sodium hydroxide breached the consent limits set by Scottish Water to adequately treat the effluent and meet SEPA consent limits without adversely affecting the aquatic environment.

Belhaven halted discharges into the public sewer when they discovered what had happened and alerted Scottish Water.

Scottish Water technicians found that the caustic effluent had made its way into filtration tanks at the Dunbar waste water treatment works. The biological organisms in the tanks which treat incoming sewage had been destroyed by shock loading of the discharged caustic solution and caused them to foam and overflow onto the ground.

Scottish Water was forced to close down the treatment plant which discharges into the Biel Water, from where it drains into the Firth of Forth estuary.

They carried out a significant amount of work to reduce the volume of effluent flow reaching the treatment works, reduce spills to the environment and clean and replace essential filtration equipment.

SEPA were alerted and an Environmental Pollution Incident (EPI) was raised. 

On 20 December 2019 East Lothian Council took the decision to erect signs at Belhaven Bay Beach which warned of the risk of possible water contamination.  The signs advised against bathing in the sea or any nearby watercourses which flowed into the bay until further notice.  The signs remained in place until 4 February 2020.

Sara Shaw, head of wildlife and environmental crime unit, said: “Belhaven Brewery Company Limited accepted liability, pleading guilty to a contravention of the Sewerage (Scotland) Act 1968.

“This incident caused extensive damage to the treatment works requiring intensive intervention and remedial action to restore the treatment works and protect the environment. There was significant public concern regarding water contamination.

“The Crown Office & Procurator Fiscal Service takes a rigorous approach to the enforcement of environmental crime: we are committed to taking effective and appropriate prosecutorial action.”