two people in site safety clothing and hard hats inspecting work done on a roof

Eastern Quarry

Castle Hill, Ebbsfleet, Kent

Castle Hill, Ebbsfleet, Kent

Client: Land Securities (Eastern Quarry Ltd)

Key Facts

  • 260 hectares
  • Situated to the east of Bluewater shopping centre and bordered by the A2
  • Former chalk quarry serving local cement production
  • Castle Hill forms the first of three villages, comprising 6 development phases, some of which are already host to occupied homes


Chalk excavation at the site began in the 1930s, and for over 70 years supplied nearby cement works via a network of tunnels. NHBC involvement began in 2005, with the Land Quality Service being commissioned prior to the commencement of earthworks that saw the quarry backfilled to create a development platform.

LQS engineers assessed the site investigations and geotechnical, and environmental assessments conducted by Arup, throughout the multi-phase earthworks programme. At key milestones throughout the project, Certificates of Land Quality were issued to indicate the stage of compliance with NHBC standards at the time of issue.

Contamination and geotechnical hazards

Very low quantities of made ground were found, and carbon dioxide, arising from reworked natural Thanet sand and Lambeth Group materials, was identified. The presence of both engineered and un-engineered site won-backfill resulted in variable depths of natural fill materials, all of which was engineer-filled to an end-product specification.

Remediation Strategy

  • A watching brief for contamination
  • Ground gas monitoring and detailed ground gas assessments
  • Gas protection measures in all dwellings
  • Engineered earthworks to an end-product specification


Up to 6,250 homes will be constructed in three new villages as part of the new Ebbsfleet Valley community, which will also host retail, leisure, educational and community facilities. The newly constructed Ebbsfleet International railway station provides access to London in fewer than 20 minutes.