Ecologia successfully completed the remediation of an industrial site which included historical former use as a gas works and production of precast concrete. Due to its long industrial legacy the underlying soils and groundwater were contaminated with asbestos, petroleum hydrocarbons, metals and volatile organic compounds. A number of former underground gas work structures also remained on site including gas holder and tar tank.
Ecologia were involved in the very early stages of the site re-development project, assisting the client in assessing the extent of contamination and advising on the most effective remediation strategy to underpin the design of the site masterplan development.
Extensive LNAPL contamination was initially encountered on part of the site and the Client decided to undertake in-situ voluntary Multi Phase Extraction (MPE) remediation in advance of planning permission being granted. This reduced the uncertainty of timescales associated with the in-situ groundwater remediation. MPE remediation proved very successful with over 4,000 litres of LNAPL being removed during this stage of the remediation works.
The remediation works commenced in conjunction with the early stages of demolition works across the site. Ecologia’s solution was to apply an integrated approach comprising:
- Bulk Excavation
- Hot Spot Removal
- Complex Sorting and Screening
- Ex-situ soil biotreatment using engineered biopiles
- Off site disposal of unsuitable materials
- Water Treatment (contaminated waters dewatering operations)
Targeted hot spot removal and treatment of contaminated soils on site allowed for the maximum re-use of suitable site won soils achieving a significant cost saving in waste disposal and import costs.
A robust validation and verification scheme underpinned the remediation works and ensured that Regulatory sign off could be achieved swiftly. Material movements on site were tracked under a Material Management Plan (MMP) which also incorporated the transfer of naturally occurring soil onto site which was required to make up for material shortages following off site disposal of unsuitable soils.
The works were completed over a period of 14 months.
This collaborative approach with the Client proved to be very successful as the potential environmental liabilities associated with the site were fully understood thus minimising remediation costs by sharing risks on specific aspect of the programme and as well being fully aware of the remediation timescales.
On the basis of this approach Ecologia provided the necessary confidence and guarantees so that the Client could successfully divest the site whilst the works were still ongoing.