Since the early 1990s, the importance of risk assessors and toxicologists in site cleanups, closures, and site reuse has expanded significantly. They have successfully assisted clients with expert application of science and new risk assessment tools, more realistic investigations, and site-specific risk assessments (to avoid impacts from generic standards) to develop Alternative Cleanup Standards (ACS), No Further Actions (NFAs), litigation assistance, etc.
Risk/Toxicology Case Studies
The range and benefits of recent ENSR risk assessment and toxicology efforts is illustrated in the following representative projects.
- Human health and ecological risk assessments were conducted for an abandoned paper mill complex adjacent to the Delaware and Musconetcong Rivers in New Jersey. Results of the assessments were integrated to develop ACS for PCBs and metals in soil. The ACS were accepted by the New Jersey Department of Environmental Protection, resulting in over $165,000 savings in remediation costs for the client, and potential site reuse.
- A highly controversial, inactive industrial facility in Louisiana, historically used for drilling fluid blending and storage operations, experienced releases to soil and groundwater. Due to exceedances of generic standards and the potential for impacts to sediment and surface water, a risk assessment was conducted. The results of ENSR's risk assessment supported a No Further Action decision based on continued industrial use of the site. This saved the client $3-6 million in cleanup costs, avoiding potentially costly litigation. The risk assessment was approved, based on one round of agency comments and with no significant changes. This was the first risk-based closure accepted by Louisiana under their Risk Evaluation Corrective Action Program.
- At one of the nation's largest Superfund sites, the Clark Fork River, ENSR's evaluation illustrated the absence of likely toxicity to river aquatic biota under current water quality conditions. The study was used by EPA to set copper water quality clean up goals protective of rainbow trout. And ENSR's proposed site-specific bulk sediment criteria were accepted and adopted by EPA, resulting in elimination of sediment removal as a remedial alternative for the river in the Feasibility Study. Remedial cost savings and documented reduced injury under the $600 million National Resource Damage claim by the State will potentially save the client millions of dollars in remediation costs and liability. Moreover, application and acceptance of ENSR's state-of-the-science sediment risk assessment studies by EPA protected the river from unnecessary damage from sediment removal remedial actions.
- ENSR represented the Water Heater Coalition in defense of potential toxicity of components used in water heaters. In a class action lawsuit, water heater manufacturers were sued for the possible toxic ingestion of decomposing polypropylene dip tubes. ENSR proved that the ingestion hazard from a potential exposure to polypropylene was insignificant. The successful disposition of the legal action for the Water Heater Coalition resulted in considerable financial savings and settlement of the lawsuit.
Risk/Toxicology Assessment Expertise
ENSR has one of the largest and most qualified risk assessment and toxicology staffs in the industry. For over 25 years, ENSR has helped clients use risk assessment and toxicology to control environmental compliance and remediation costs at over 2,200 facilities and sites throughout the world. The staff of more than 50 professionals includes: Board-Certified Toxicologists, Certified Ecologists, and University Faculty Affiliates, and over 20 Ph.D.s. ENSR's expert agency negotiations, risk communication skills, and innovative technical approaches have saved clients millions of dollars while protecting human health and the environment.