29th August 2026
Publicly available verification and strategy documents (particularly the 2011 Site Completion Report by Urban Vision and related papers) set out the actual methods employed. The approach was primarily a cover / barrier system, supplemented by localised handling of asbestos and gas-protection measures in the buildings. Full “dig-and-dump” of the entire made ground was not used.
1. Main technique: Engineered Cover System
The core remediation strategy (detailed in UV/000174-01, December 2009, and verified in 2011) was the installation of a clean cover system across all soft landscaping areas. This created a physical barrier between site users (especially children) and the underlying made ground.
Minimum thicknesses specified and verified:
- Topsoil: minimum 150 mm
- Subsoil: minimum 250 mm
- Geotextile membrane or capillary break layer: minimum 100 mm
- Total clean cover: minimum 400 mm
What was actually achieved (verification results, 2011):
- Sports pitch area: average ~500 mm of imported clean material.
- Landscaped areas: average 300 mm topsoil over 300 mm of clean stone chippings (total meeting or exceeding the 400 mm requirement).
- The school buildings themselves were constructed on 300 mm of clean imported stone chippings.
Imported clean soils were chemically validated before placement. Statistical analysis of the imported material confirmed that key contaminants (including lead) were well below relevant assessment criteria.
2. Asbestos management
Small amounts of asbestos (including brown asbestos / amosite in some reports) were identified in site-won material.
A specific remedial plan was agreed with Stockport MBC Environmental Health and implemented by BAM Construction. This involved:
- Identification and segregation of asbestos-containing material.
- Hand-picking / careful removal of visible asbestos in affected areas.
- Appropriate off-site disposal of the contaminated fraction under licensed waste controls.
- Re-use of suitable (non-asbestos) site-won material where validated as acceptable.
Contemporary press reports (2010) noted contractors sifting material by hand when brown asbestos was encountered during preparation works.
3. Building gas / vapour protection
At the request of Stockport MBC Environmental Health, precautionary gas-protection measures were incorporated into the buildings because of updated radon guidance and the presence of made ground:
- Reinforced concrete cast in-situ floor slabs (suspended, non-suspended or raft).
- High-specification damp-proof membrane (at least 1200 g DPM).
No significant hazardous ground-gas elevations were recorded during monitoring, but the protection was installed as a precaution.
4. What was not done as the primary method
- Widespread deep excavation and off-site disposal of the bulk of the made ground (1.3–7.0 m thick in places) was avoided.
- Early ideas of simply fencing off “hotspots” and planting thorny shrubs were rejected.
- The strategy relied on breaking the pathway (cover system + hardstanding + building membranes) rather than removing the entire source.
Verification
The 2011 Site Completion Report confirmed that:
- The cover system met or exceeded the agreed thicknesses.
- Imported soils were chemically suitable.
- Asbestos had been appropriately managed. (Had it? See video evidence above).
- The works were in accordance with the approved Remediation Strategy and Stockport MBC Environmental Health requirements.
Summary
The dominant technique was a clean soil cover system (minimum 400 mm) over soft areas, combined with localised asbestos removal/hand-picking, re-use of validated site material where possible, and gas-protection membranes in the buildings. This is a common, cost-effective approach for former landfill/made-ground sites being redeveloped for sensitive uses such as primary schools, provided the cover remains intact and is properly maintained.
