Since the original Consent Order & Agreement between Sunoco and DEP in 1993, Sunoco and Evergreen have implemented several interim remedial actions at the refinery. Various remediation systems were installed in the facility in 1995 to prevent the migration of impacted groundwater offsite. Additional remediation systems have been installed since that time to either address source removal (removing petroleum product and contaminated groundwater at the source of the release on-site) and/or control the migration of impacted groundwater beyond the property boundary. Between 1993 and present, 25 remediation systems have been operated at the refinery by Sunoco/Evergreen.
Remediation activities have included, but are not limited to:
- Groundwater and/or product recovery via both vertical and horizontal wells, where product and/or groundwater impacted with hydrocarbons are removed from the subsurface;
- Oxygen injection into groundwater ,to aid in removal and/or breakdown of petroleum products in the subsurface;
- Sewer ventilation systems, or the removal of petroleum vapors from air in subsurface utilities; and
- Soil vapor extraction, or removing petroleum vapors from the subsurface.
Many of the remediation systems have been decommissioned over the years when they have achieved their intended purpose and/or other remedial alternatives have been selected. Evergreen currently operates nine remediation systems operating at the facility. In addition to remediation systems, areas of soil have been remediated at the facility via excavation and/or capping.
As discussed above, after the Fate and Transport RIR, Human Health Risk Assessment and Ecological Risk Assessments are completed, these interim remedies – along with potential additional remedies – will be evaluated and included in the Act 2 Cleanup Plan.