CampbellReith was appointed by the London Borough of Havering (LBH) in 2010 to undertake a Part 2A contaminated land assessment of a former landfill site, which now forms the southern area of the Hornchurch Country Park. Prior to being used for sand and gravel extraction and subsequent landfilling, the site formed part of RAF Hornchurch. The adjacent river Ingrebourne and associated marshes are considered a Site of Special Scientific Interest (SSSI).
CampbellReith provided a desktop study and a detailed scope of recommended site investigation works which were subsequently used by LBH to procure funding from DEFRA. The investigation works were implemented to assess: ground gas risk to existing properties; risk of pollution to water courses from soils; risk to the general public (current and future users) from potentially contaminated soils and Unexploded Ordnance; and, risk to the neighbouring SSSI.
Following the investigation works, a comprehensive land quality report was produced for the purpose of Part 2A determination, which identified a potentially significant risk in relation to ground gas. Additional works were developed in 2013 and 2014 to further investigate this issue, using a combination of conventional gas monitoring, GasClam continuous monitors and soil spike monitoring.
GIS helped to illustrate the geotechnical findings and the likely distribution across site, as well as visualising gas migration and ingress routes which result from historic landfill.