Portfolios Archive - Page 3 of 6

Ealing

The site located in Ealing was previously utilised as a truck MOT and servicing unit and the redevelopment objective was to construct a fire fighting training facility. Site investigation identified contamination as a potential risk to human health, development infrastructure and controlled waters therefore remediation work formed part of the planning conditions.

Ash Remediation Management were involved with the site from an early stage which allowed us to advise our client on numerous issues which ultimately expedited the site development programme. The scope of our involvement entailed remediation and earthworks and a summary of our package is detailed below:

Clean, degas and remove the two underground fuel tanks, associated pipe work and interceptors
Delineate the soils surrounding the historical on site fuel storage apparatus and determine the extent of any potentially contaminated soils
Excavate material that exceeds the re-use acceptability criteria and send for off-site remediation/regeneration
Excavate and break out the existing hard standings/concrete slab and any underlying hard materials. Process the product of the breakout to 6F2 classification
Validate through chemical testing the excavations previously containing the fuel storage apparatus
Carry out six rounds of groundwater monitoring

Ash Remediation Management completed their work programme ahead of schedule and all paperwork and regulatory documents were submitted under the cover of a project report. This allowed release of the remediation based planning conditions and successful continuation of the development.

Addlestone

Client – Independent Developer

Principal Contractor – Ash Remediation Management

Consulting Engineer – Geo Environmetal Group

Location – Addlestone

Contract Value – £50K

The former petrol filing station and motor repair garage is located in Addlestone, Surrey and a London Based property company purchased the site to enable its redevelopment into a small retail centre. However, owing to the sites previous use and its close proximity to a sensitive watercourse, remedial attention formed part of the planning conditions.

Ash Remediation Management were involved at the inception of the project and their initial responsibility was to take the lead role in the site investigation work. On completing the exploratory work as well as attaining regulator approval of their remediation strategy, Ash Remediation Management were awarded the contract to carry out the remedial phase of the project.

The scope of the remediation work is summarised as follows:

Removal of the underground storage tank (UST) and associated grossly contaminated soils
Formation of a cut off/interception trench and disposal of any grossly impacted soils
Abstraction of free product and contaminated groundwater from the UST and trench excavations
Further, periodic disposal of any free product and groundwater that accumulated in the UST or trench excavations

All materials removed from site were disposed of at appropriately licenced waste treatment facilities. The capabilities of these sites allowed treatment and regeneration of the material, an important factor in Ash Remediation Managements commitment to sustainability. Moreover, this ‘green’ route of disposal minimised our clients costs as tax expensive landfilling was avoided.

To supplement and verify the above, Ash Remediation Management designed a monitoring scheme. The regulator approved document involved the installation and sampling of a series of groundwater monitoring wells as well as the sampling of an adjacent watercourse.

On conclusion of the monitoring program Ash Remediation Management produced a report of the remedial work. This was submitted and agreed by the regulator allowing the release of the associated planning conditions.

North Shore

Client – Homes and Community Agency

Principal Contractor – Lumsden and Carroll

Consulting Engineer – Halcrow

Location – Stockton-on-Tees

Contract Value – £400K

The North Shore project is located on the north bank of the River Tees adjacent to the Infinity Footbridge in Stockton-on-Tees. Diesel oil based contamination had been detected in the River Tees and investigation identified the source as a number of underground fuel tanks. The diesel was migrating through the groundwater and Ash Remediation Management installed a groundwater treatment barrier to sever the pollution linkage pathway.

Each barrier system installed by Ash Remediation Management is bespoke and numerous design parameters are taken into account prior to installation. Variables considered include its position and depth in relation to the contaminant source, treatment capabilities and design life. These important design decisions are augmented with groundwater modelling and column testing. Prior to the installation of the North Shore barrier, the final design was agreed with the consulting engineer and Environment Agency.

The resulting design was applied using the soil mixing capabilities of a piling rig. The treatment slurry was produced in an automated batching plant and delivered to the rig via a semi automated pumping system. As the auger rotated slurry was injected through the modified drilling head and mixed with the surrounding media. During the mixing process the rig’s on board computer generated real time drilling data which enabled the driver to ensure equal dispersion and homogenisation of the slurry. Drilling data was recorded daily and used in the quality control process.

On completion of installation the regulator approved monitoring scheme commenced. Monitoring wells upstream and downstream of the barrier were sampled for a period of two years. Upstream wells provided data on water quality impacting upon the barrier and those installed downstream illustrated the quality of water migrating through.

The monitoring demonstrated the success of the barrier system and the associated report produced by Ash Remediation Management was approved the Environment Agency.

The project was completed on time, on budget with a zero accident record.

Welling

Ash Remediation Management successfully treated and removed Japanese Knotweed from a former industrial site in readiness for the development of a residential care home.

Stourbridge

Ash Remediation Management have recently completed a treatment and long term maintenance scheme on behalf of a medium sized construction company.

Liverpool

Ash Remediation Management were contacted by a landowner who suspected a Japanese Knotweed issue. Early intervention prevented further spread and the site was ‘Japanese Knotweed free’ after a single herbicide application.

Dudley

Ash Remediation Management were commissioned by Dudley Metropolitan Borough Council to control Japanese Knotweed at a sports college.

Croydon

Ash Remediation Management devised a successful treatment and long term maintenance programme to eradicate Japanese Knotweed from a housing development.

Brixton

Ash Remediation Management were contracted by a local authority in central London to control Japanese Knotweed at an infant school as part of a refurbishment contract.

Audley Gasworks

The former gasworks is located in Shropshire and it was purchased by a midlands based house builder. The site was polluted with typical gasworks contaminants (namely polycycic aromatic hydrocarbons (PAH), total petroleum hydrocarbons (TPH), lead and cyanide) and in order to comply with planning regulations a detailed remediation programme was undertaken.

Ash Remediation Management provided a full remediation scheme including chemical stabilisation/solidification, bioremediation and the removal of contaminated waters. This case study discusses the ex-situ bioremdiation aspect of the project.

Material undergoing ex-situ bioremediation was conditioned with agricultural fertilisers and compost. In order to control internal biopile conditions as well as environmental releases, a closed aeration system was utilised. Coupled to this was regular interpretive monitoring, used to optimise the efficiency of the biopile. A total of 1400m³ of material underwent a 15 week treatment programme and the bioremediated soils were used as subsoil in the residential and landscaped garden areas.

All phases of the project were achieved within budget and the bioremediation work was concluded 8 weeks inside the project deadline.