The 3M manufacturing plant at Zwijndrecht in Antwerp province was the scene of an incident in February this year, when a quantity of sodium hydroxide, a caustic chemical, was accidentally released into the soil, Gazet van Antwerpen has revealed.
The plant is at the centre of an ongoing investigation into the pollution of the surrounding ground with PFOS, a chemical hazardous to human health. Residents within a perimeter of 15km have already been advised to avoid eggs laid by hens in the area, as well as vegetables grown in local soil.
The release of sodium hydroxide involved about 43 cubic metres of the chemical, about four times the capacity of a cement mixer truck. The incident was confirmed to the paper by OVAM, the Flemish waste management agency.
The incident took place on 14 February; OVAM was notified on 4 March. According to the company, the incident was caused by thawing of frozen pipes. A quantity of the chemical could be recovered, according to a company spokesperson.
OVAM brought in an expert to assess the damage, who immediately imposed protective measures on 3M to last until the end of August, while a decision is taken as to what needs to follow.
“Depending on the findings of the remediation expert, it is possible, among other things, to excavate the contaminated soil, install a water purification system, excavate and have the contaminated soil processed, and so on,” said the spokesperson.
Sodium hydroxide (NaOH), also known as lye or caustic soda, is a highly caustic alkali which can cause chemical burns. It is used in the manufacture of paper, textiles. Soaps and detergents, and as a drain cleaner.
If released into a water-course, it reduces the acidity of the water and can be hazardous to aquatic life.
The paper also reported that the incident had never been reported to the Flemish environmental inspection service, who only became aware when reporters approached them with questions.
“We have further investigated this and 3M is required by regulations to report such an incident,” said spokesperson Brigitte Borgmans.
“The company has only reported the fact to OVAM. We will draw up an official complaint for their not reporting to us. The further processing itself (soil investigation and remediation) is carried out by OVAM.”