The identification and subsequent treatment of contaminated land and groundwater is currently being regulated by the Environment Agency. The closure of gasworks sites during the late 1960s left areas of land contaminated with undesirable residues of the manufactured gas process, which were left to cause further pollution by leaching into surface and groundwater. The techniques available to remediate these contaminated media are numerous, but most tend to suffer from at least one major disadvantage, usually time or cost.