Project: School Lane, Mistley Maltings
Client: Major House Builder
Contract Value: £17,050

Knight Environmental Limited provided a complete programme of technical support including remedial design, liaison with the regulatory authorities, completion of the remedial works and validation testing at the site at the former Maltings site at School Lane, Mistley.

The site investigation identified concentrations of arsenic and elevated levels of hydrocarbons above screening levels in localised areas. Asbestos containing material was visually identified at the same site, and fibres were detected by laboratory analysis.

Knight Environmental Limited undertook remedial works in May 2004 at the School Lane Maltings Site, Mistley, Essex. The key objectives of the remediation can be summarised as follows:-

Limit the direct exposure of future residents and ground workers to ground contamination.

Reduce the risk to construction materials from ground contamination to acceptable levels.

Reduce the risk to future planting in landscaped areas from ground contamination.

Zonal removal of localised areas identified in the site investigation to be chemically impacted and subsequent backfilling with chemically acceptable inert soils was believed to be the most practicable remediation option to reduce the risks to human receptors. Furthermore, as a result of the elevated level of carbon dioxide, gas protection measures were implemented. This part of the works is to be carried out during the construction works.

The following key operations formed the basis of the site works required to decontaminate the site:-

1. Remove localised areas of impaction by excavation and disposal of contaminated soil to prescribed depth below ground level.

2. Validation of the excavated areas of impaction.

The remediation scheme was approved by Regulatory Authorities prior to the commencement of the works.