THE company behind the major Poole Harbour oil spill previously leaked 40 barrels of hydrochloric acid, the Echo can reveal.

Anglo-French oil and gas company Perenco received two formal warnings from the Environment Agency (EA) in a ten-year period for incidents at its Wytch Farm facility in Purbeck.

In October 2020, around 6.25 cubic metres (40 barrels) of liquid – 28 per cent of which was hydrochloric acid – spewed into the site’s ‘moat’ storage system.

The EA said that although no offsite environmental impact was noted, the initial spillage had the “potential to be harmful to those working on site and the local environment”.

Following an internal investigation, it was determined that a short pipe coupling connected to the tank had corroded after coming into contact with the acid.

Dorset Echo: Wytch Farm across Poole Harbour. Image: Chris Skone-Roberts Wytch Farm across Poole Harbour. Image: Chris Skone-Roberts

According to EA documents, the root cause of the incident was believed to be a lack of equipment for acid jobs and a need for additional training for operatives involved in its use.

Perenco received a warning for the permit breach. 

In March 2013, the private firm was given a formal caution after the release of 14 cubic metres of crude oil and 560kg of gas that polluted water in the area along with vegetation and trees.

The cause was listed as several electrical failures.

Documents also reveal that the EA visited the Wytch Farm site in February – just one month before 200 barrels containing oil leaked from a pipeline on March 26, sparking the recent major incident declaration and clean-up operation.

Dorset Echo: Protest at Poole Quay on Monday, March 27, after oil spill in Poole Harbour.Protest at Poole Quay on Monday, March 27, after oil spill in Poole Harbour. (Image: Newsquest)

Perenco has operated the Wytch Farm site since December 2011 and its previous compliance is rated as ‘good’.

An EA spokesperson said: “An investigation has already begun into the cause of the pollution, which will include consideration of whether conditions of the environmental permit have been adhered to.

“If it is found that there have been breaches of the permit, appropriate enforcement proceedings would take place. As part of our investigation, we will be looking at what improvements the company can take to prevent future incidents such as this.”

The site is regulated by the EA which has issued several permits that cover 14 areas (including 11 well sites) in Poole Harbour.

The permits cover activities such as refining gas and collection of crude oil.

Protestors took to Poole Quay the day after the 2022 leak, demanding action against Perenco.