FORMER RETAIL GASOLINE FACILITY
Conneaut Lake, Pennsylvania
During July 1991, our client closed three out-of-service underground storage tanks (USTs) and sought to characterize the area surrounding two previously closed-in-place USTs at their former Conneaut Lake, Pennsylvania Service Station. Analyses of the soil characterization samples indicated the presence of petroleum impacts in the tank excavation areas. Results of a subsurface investigation, conducted in October 1991, confirmed the presence of benzene, toluene, ethylbenzene, and total xylenes (BTEX) in both the soil and groundwater in the former tank areas. The results of a soil gas survey performed in March 1992 determined these compounds did not migrate beyond the property boundaries.
A Remedial Action Plan was submitted to the Pennsylvania Department of Environmental Protection (DEP) during January 1993 and implemented August 1993. A soil vapor extraction and air-sparge system was operated from August 1993 through October 1996. Dissolved-phase hydrocarbons in groundwater were significantly reduced site-wide. However, concentrations of benzene in groundwater at one monitoring well remained above the Act 2 Statewide Health Standards (SWHS) for Non-Residential Used (NR-U) Aquifers. The point of compliance for soil is the area of contamination that was delineated during the soil gas survey. The analytical data for soil samples collected during August 1995 remedial activities were below the July 1995 DEP SWHS for soil. During August 1998, an oxygen releasing compound (ORC™) was applied in the vicinity of the impacted monitoring well to increase the dissolved oxygen concentration in the groundwater and, thereby, accelerate the microbial decomposition of hydrocarbons in the groundwater. Subsequent groundwater monitoring results indicated that the contaminant plume had diminished.
Subsequent analytical data from these POC wells were compliant with the SWHS under Act 2. However, groundwater monitoring was continued by the previous consultant, even after the DEP-required 8 consecutive quarters was achieved. Based upon attainment at the POC and the diminishing plume observed at the aforementioned monitoring well, the CPEG team prepared and submitted a Remedial Action Completion Report (RACR) for the site, including statistical trend analysis to support environmental site closure. DEP reviewed and approved the RACR, as submitted.
Total cost of project: $12,000
CPEG Business Solutions… Yield Advantages
Once the CPEG team was awarded the project, a strategy to obtain environmental site closure was quickly formulated and implemented. The CPEG solution included no new site investigation, yielded site closure with minimal costs, eliminated client legal liability, and saved our client thousands of dollars associated with continued compliance monitoring. These tasks included:
- Submitting a request under the Freedom of Information Act (FOIA) and conducting a review of DEP Files to obtain adequate background information.
- Assessing the content of the previously submitted reports and associated data to determine if sufficient information was available to close the site under DEP’s Chapter 245 regulations.
- Preparing the Remedial Action Completion Report in accordance with DEP’s Chapter 245 regulations using available data.
- Obtaining DEP Approval of Site Closure and Release of Liability at the subject site by preparing and submitting only one report.