John F Hunt Regeneration (JFHR) were contracted in August 2022 by Folkestone and Hythe District Council to undertake a package of remediation and civils works to prepare a 4.5- hectare Site known as ‘Biggins Wood’ for redevelopment.
The former landfill and brick works site will comprise of 660m² of commercial/office accommodation, 5,142m² of industrial/storage accommodation and 77 residential units.
Scope of Works
In summary, JFHR’s works comprised of:
- Ecological works to the satisfaction of the Local Planning Authority, including the installation of a reptile fence, construction of hibernaculas/log piles and reptile translocation,
- Relocation of builders merchants access and egress,
- Installation of tree protection fencing,
- Stripping the site of vegetation, shrubs, and unprotected trees in accordance with the Reptile Mitigation Strategy,
- Testing of sub formation on the proposed access road to allow for a complete highway design in accordance with the Kent Design Guide for Section 278 and Section 38 Agreements,
- Excavation, disposal, and initial treatment of invasive weed species, JKW & Mares Tail providing an Insurance Backed Guarantee and ongoing treatment strategy,
- Process and removal of inherited stockpiled materials and removal of Asbestos Containing Materials (ACM’s) assessed as NNLW working conditions,
- Remediation of the site to the satisfaction of the Local Planning Authority,
- Cut/fill to leave site levels within 250mm of existing ground levels, and
- Removal of contaminated materials.
Site History and Background
The Conceptual Site Model identified contaminants within the Made Ground, such as lead, arsenic, mercury, and Poly Aromatic Hydrocarbons (PAH). However, given the extent of the Made Ground and nature of the site, remediation was not considered viable. JFHR’s role was to mitigate the risk to human health through the management of pathways rather than through the mass remediation of the Made Ground which would have rendered the project economically unviable.
One of the biggest challenges of the site was that it was of particular ecological importance. Surveys identified the land supported Slow Worm and viviparous lizard populations which are legally protected under the Wildlife and Countryside Act 1981 (as amended).
Prior to any material movement, a series of tasks, listed below, were required to minimise the possibility of fatalities or injuring the reptiles from construction related activities.
Ecology
To facilitate the relocation and subsequent discharge of planning conditions associated with the translocation of reptiles. JFHR commissioned principal ecologists, Wardell Armstrong, to meet the supervisory requirements of the Reptile Mitigation Strategy. To ensure compliance and the success of the translocation, JFHR ground flailed all of the vegetation in the development area, installed 10no. new habitats through the construction of hibernaculas and log piles, and oversaw the installation and imaintenance of ~1km of reptile exclusion fencing to prevent the reptiles from re-entering the development site and causing a delay to the following construction phase. JFHR also managed and maintained a 60 day reptile capture programme, undertaken between September and November 2022. This resulted in the successful relocation of 221 reptiles to the new receptor sites constructed and installed by JFHR.
In addition to this, JFHR undertook the effective excavation, removal and treatment of Japanese Knotweed (JKW) and Marestail across four areas of the site under the supervision of a qualified ecologist. These works made allowance for ongoing management of previously impacted areas.
221 Reptiles successfully translocated.
5 Hibernaculas built.
5 Log piles constructed.
Management of Contaminant Pathways
In total, 1.96 tonnes of asbestos was handpicked, double-bagged and disposed of in an enclosed skip to a suitably licensed hazardous waste facility from 350m³ of inherited construction arisings to the east of the site. All contaminated material and works were managed in accordance with the Control of Asbestos Regulations (CAR) 2012 and JIWG CAR Soil Guidance.
The removal of this stockpile facilitated the final relevelling of the site within 250mm of existing ground levels across the development platform.
Supporting the Local Economy
Where possible, JFHR is committed to creating partnerships with local suppliers, reducing GHG emissions, and locally sourcing materials. Biggins Wood is an example of this commitment, with:
- 9.72 tonnes of concrete, brick/rubble and asphalt recovered from the cut and fill being transported to a recycling facility <80m from the site entrance.
- Construction materials procured from the builders’ merchants that shares the site’s entrance and relocation of their access/egress point to mitigate the impact of the construction works.
- A contract with the coachworks company to the east of the site to utilise part of their yard for the site welfare. Traditionally, the company would not have had any involvement in the scheme, but by building a relationship with them, they also received help to maintain their yard, and minimised transport on the roads by using the existing drainage and water supply instead of using tanker deliveries.