Former Retail Gasoline Station

The Plan

This project originally came to HCR under the Low Score Site Initiative (LSSI) program. The project site is a former retail station that once utilized multiple underground storage tanks (USTs) for gasoline, used oil, diesel and kerosene. The tanks were previously removed, however HCR uncovered 4 unknown USTs during excavation work. HCR was able to work with the client to properly abandon and remove the steel tanks.

The Work

The scope included the removal of a canopy, abandonment of a shallow monitoring well and source removal of approximately 400 cubic yards of soil. The extent of the excavation was approximately 50’x35’x10’. Dewatering points were installed along the perimeter of the excavation and the groundwater effluent was treated before disposal. Prior to backfilling the excavation, Oxygen Release Compound Advanced (ORC-A) was added to the open pit. Installation of the replacement canopy was conducted after well installation activities were completed. Safety challenges were encountered, which included a water line that was in direct conflict with the proposed canopy columns on the north side. The line was eventually re-routed around the columns. Discharge of the treated groundwater was problematic initially, due to pedestrian and vehicular traffic. To reduce the risk of injury from slip, trip and fall hazards, the discharge hose was run on the interior of the site fencing, eventually discharging in the southeast corner. The water ran across the sidewalk to the storm drain in the street.