Project: Prince Albert Road, West Mersea
Client: Sunny Side Homes Ltd
Contract Value: £6,730

Knight Environmental Limited provided a complete programme of technical support including additional site investigation, risk assessment and liaison with the regulatory authorities at a site located at Prince Albert Road, West Mersea.

The site investigation identified elevated concentrations of boron and water-soluble sulphate within the underlying Made Ground and within the underlying alluvium band in localised areas. Samples from the underlying groundwater identified slightly elevated boron and total petroleum hydrocarbons.

Some elevated gas levels were measured during monitoring visits to the site.

The elevated total petroleum hydrocarbons and boron levels were assessed to offer a potential of harm to end-users and planting on the site. The risk to groundwater was considered less problematical due to the site being outside of an identified groundwater protection zone, therefore the recommended remedial measures were:-

To raise the final levels by at least 0.6 metres with the fill material validated as being chemically suitable for use in garden areas.

Incorporation of gas protection measures within the development tomitigate the risked posed by land gases.

The assessment of the groundwater within the underlying strata revealed a medium risk to the Blackwater Estuary. It was recommended that a groundwater monitoring programme  (subject to the approval of the Environment Agency) be undertaken to monitor the groundwater plume.