Gas station risk assessment closure
On behalf of a local developer, Troy Risk successfully obtained a No-Further-Action certification from the State environmental agency IDEM in just several months.
The site historically operated as a gas station. Several subsurface investigations at the site confirmed that soil was impacted from an old petroleum release. The release was discovered in 1994 during collection of soil and groundwater samples from borings advanced in the gasoline tank pit. Uncertainty concerning the nature and extent of environmental impact and cost of remediation stymied development of the property for more than 12 years. A Corrective Action Plan that proposed on-site treatment of impacted soil was approved, but never implemented.
The scientists at Troy Risk had a different idea. Although soil was still impacted, groundwater impact had attenuated; we felt that this site was a good candidate for a non-default risk-based closure. Troy Risk prepared a plan that proposed minor soil excavation of a hot spot and utilized RISC TPH Fractionation methodology to identify a higher closure level. The advantage of TPH Fractionation is that a site-specific closure level can be developed, based on the specific toxicology of the petroleum impact at the subject site.
Upon IDEM’s approval of the plan, non-default closure levels were developed based on TPH Fractionation. In addition, a small excavation removed the remaining hot spot of impacted soil. Upon review of Troy Risk’s Completion Report, IDEM issued the developer a No-Further Action certification.