Value: £6.5 million
Remediation of the site involved the excavation, on site treatment and disposal of segregated wastes, excavation of over 110,000m³ of material and bioremediation of 20,000m³ of material.
The former Clough Road Gas Works in Hull covered an area of 17ha located only 20 metres from the River Hull. Site investigations had identified contamination to soils and groundwater by gas production by-products including tar, poly-aromatic hydrocarbons (PAHs), ammonia, spent oxide, phenol, cyanide, TPH and heavy metals.
The remedial works were undertaken over a 72 week programme together with groundwater treatment. Following excavation, the voids were backfilled using a combination of imported materials and site-sourced materials, with the intention of maximising recycling wherever possible. The project also required the off-site disposal of up to 40,000m³ of material contaminated with “Blue Billy”; however, due to a process of careful segregation this was reduced by 50%. Any asbestos containing materials were subsequently classified and treated or disposed of following a quantitative assessment.