The Environment Agency started to monitor for perfluorooctance sulfonate (PFOS) in the vicinity of the site following the fire in order to give a better understanding of the impact of the incident on the environment.
The agency has been closely monitoring the River Ver, and have detected low levels of PFOS in the river both during and after the Buncefield incident. No evidence to date has been observed of any impact on fish or other wildlife in the river as a result of this contaminant.
Water samples have been taken from the network of groundwater boreholes both on the Buncefield site and in the surrounding area. These samples have also shown evidence of the presence of PFOS mainly at low levels or below the limit of detection. Two samples however showed elevated levels of PFOS at 4.5 and 5.9 micrograms/litre. Repeat testing of the sample giving the higher result, showed a much lower level of 0.20 micrograms/litre.
The latest results of this groundwater monitoring were the subject of an Environment Agency press release on Friday 12 May. Details can be found on the agency website at: http://www.environment-agency.gov.uk/news/1387272.
The agency has instigated a significant programme of work to further monitor the presence and extent of PFOS in both surface and ground waters in the environment around Buncefield. This programme will also look at background levels of PFOS in the wider environment in England and Wales.
The Environment Agency will continue to make public its findings as they emerge.