Risk assessment and selection of remedial action alternatives the Volgermeerpolder case study

Abstract An attempt was made at risk assessment to evaluate the remedial options for the Volgermeerpolder hazardous waste disposal site located north of Amsterdam. The final remedial alternative selected by the responsible authorities consisted of an open dynamic barrier system aimed at manipulating groundwater flow. Several environmental pathways for the migration of hazardous chemicals were identified. A limited group of compounds was selected for evaluation by ranking their extent of contamination and toxicity. The major compounds selected were the chlorobenzenes, the hexachlorocyclohexanes, the chlorophenols, 2,3,7,8-TCDD, 2,3,7,8-TCDF and 2,3,4,7,8-PCDF. The risk evaluation process was focused on the relative level of risk for each route of exposure. Life time cancer risks and total site-specific acceptable daily intakes were calculated. It could be concluded that the final remedial alternative, which had been selected by the authorities and accepted by the public, is less effective than either complete excavation and removal of the waste or the complete isolation option, but offers sufficient protection for human health.