States still digging for lasting solution to deal with Pfos soil
INVESTIGATIONS are still under way to find a permanent way to deal with Pfos-contaminated soil at the airport, after the five-year licence for the current measures ran out last year.
Pfos was used as a firefighting foam at Guernsey Airport, but it does not degrade in the soil and it had been found to leach into St Saviour’s Reservoir, which supplies Guernsey’s drinking water.
While it is not believed to be in concentrations that will harm islanders’ health, it was decided that soil contaminated with the chemical needed to be removed.
In 2012, more than 14,000 tonnes of contaminated soil were removed from around the airfield.
Ports general manager Colin Le Ray said the soil had been stored in the specially constructed sealed cells at the entrance to airport, which ensure the chemical cannot leak out.
‘The cell containing the contaminated soil is subject to regular monitoring to ensure that the chemical is contained,’ he said.
‘In addition, a dedicated groundwater treatment plant was also constructed in 2012, within the airfield. This removes any traces of Pfos that may still be present on the site to prevent it entering the streams that supply St Saviour’s Reservoir.’
All these measures have been overseen and licensed by the Office of Environmental Health and Pollution Regulation.
The licence was valid for only five years, while a permanent solution was found to either treat the soil or dispose of it.
‘However, the cell itself was constructed with a 20-year life, and the routine monitoring shows that the chemical is now securely contained,’ Mr Le Ray said.
‘A second, smaller cell was also created in 2015, adjacent to the original containment cell.
‘This has been used to store an estimated 2,500 tonnes of Pfos contaminated soil from a field on Forest Road, where an aircraft crashed in 1999.
‘This is subject to the same waste management licence.’
Specialist Pfos consultants are investigating a number of options for permanently dealing with all this material.
‘Some of these rely on emerging treatment processes, hence the reasons why this process has been ongoing for some time,’ Mr Le Ray said.
‘These are continuing to be assessed along with the OEHPR, which ultimately will have to approve any solution.
‘Finding a good permanent solution at a reasonable cost are the key objectives.
‘£3m. was set aside within the budget for the Airport 2040 redevelopment, but the final cost will depend on the treatment option that is chosen.
‘That could include export for disposal in a hazardous waste landfill site, or some form of soil remediation process to remove the chemical.’
Mr Le Ray said in the interim the waste management licence had been extended to allow the assessment work to continue.
‘The monitoring of groundwater around the containment cell and the treatment of water before leaving the site are therefore ongoing.’
