The cost effectiveness of contaminated land remediation stategies

British Gas has a major programme of contaminated land remediation, reclaiming the sites of many former gasworks for other beneficial uses. On behalf of its customers and shareholders, the company must ensure that its approach to remediation is as cost-effective as possible, while meeting all environmental obligations. The development of two disured sites presented the opportunity to examine the cost benefit of remediation, both in terms of the level of site investigation needed to minimise unforeseen costs in the subsequent remediation phase, and to compare the relative costs of alternative remediation techniques. The case studies demonstrated a substantial cost benefit of an extensive site investigation prior to remediation works, while a comparative analysis of remediation techniques concluded that landfill was the least expensive, compared with bioremediation and soils washing. However, with the addition of the landfill tax, the costs of alternatives to landfill disposal become more comparable. As more experience is gained of the new techniques, costs should fall, helping to encourage a wider choice of cost-effective remediation approaches in the UK.