THE APPLICATION OF RISK ASSESSMENT TO CONTAMINATED LAND - THE BRITISHGAS EXPERIENCE

British Gas owns over 900 sites within the UK with a total land area i n excess of 5500 ha. Many of the sites are former gasworks, chemical w orks or associated holder stations. Although serious attempts were mad e to remove contamination during the last three decades, the operating and demolition standards previously considered to be adequate may no longer be acceptable and may have given rise to sites with the potenti al to contaminate adjacent land, surface waters and groundwater. As a result, further actions may now be required on these sites to reach ne w environmental standards, thereby reducing any chance there may be of legal liability on the Company. This paper describes the advantages a nd disadvantages of several qualitative and quantitative risk-assessme nt methods which can be used to prioritize potentially contaminated si tes for further investigation. The use of site investigation data to a ccurately target risk reduction in site remediation proposals is also discussed.