Comparative Chemical and Physical Risk Assessment for Two Remedial Alternatives
- Challenge: A client needed to evaluate a former pesticide manufacturing Superfund site in northern New Jersey that had dioxin-contaminated soils. There was public concern that the completed on-site containment remedy would be less effective than an excavation/off-site incineration remedy and the USEPA was considering whether to change the existing remedy during the scheduled two-year review of the site.
- Approach: Cardno ChemRisk performed a screening-level comparative risk assessment for the two remedial alternatives: an on-site containment alternative and an excavation/of-site incineration alternative. Human health and ecological risks were considered.
- Findings: The assessment showed that the risks from an excavation/off-site incineration remedy were 10 times greater than those associated with on-site containment, and also resulted in more dispersed risk. Notably, the risk of an accident or fatality while contaminated materials were being transported for excavation/off-site incineration remedy was 1,000 times higher than the on-site containment remedy.
- Value: The USEPA Region 2 subsequently chose not to re-evaluate the remedy and continued with the onsite containment remedy, ensuring a sustainable solution. In addition, the approach and results were published in a peer-reviewed manuscript, which improved transparency and could be used to inform similar efforts in the future.