Draycott Gas Works, Collis House. 2013 – 14
Ivy House Environmental were contacted by the owner of Collis House to advise on the remediation of their property, which was to be determined under Part IIA contaminated land legislation by the local authority. Site investigations at their property had previously confirmed the presence of high concentrations of cyanide, lead, petroleum hydrocarbons, PAH’s and arsenic in topsoil across the gardens and in land around the plot.
The rural location of the house and the presence of the client’s family during the works meant that the remediation project was not going to be straight forward. Due to the primary access being across a Grade II Listed railway bridge, with weight and width limits, the logistics and costs involved in a conventional dig and dump operation were highly restrictive; the bulk excavation of contaminated soils and made ground from the gardens would also generate a significant amount of contaminated dust, which would pose a significant risk to the family and their neighbours.
Our Skillset Provided: Part IIA, Gas Works, Remediation, CL:AIRE MMP
Eventually, after much discussion with the client and the local authority is was decided to leave the contamination in-situ and to cap it under a newly landscaped garden. The design was inspired by the client’s Spanish property and centred on the use of patterned concrete to landscape the garden and the re-use of contaminated spoil in raised beds capped with permeable concrete. Lawns were created using permeable concrete as a base under imported topsoil and turf and the driveway was capped with recycled aggregates under a geotextile and gravel cover.
The zero-waste brief was directed by the CL:AIRE Materials Management Plan (MMP) and the works were approved at all stages by the local authority’s contaminated land officer. The remediation works were designed and managed by Ivy House, who worked alongside the patterned concrete contractor in implementing a unique and innovative remediation project. The works created a stunning and safe garden for the client, whose family now live in a safe environment.