After a furnace maintenance visit, the home owner discovered a heating oil release to the basement. Approximately one-inch of standing oil was observed on the porous concrete/gravel basement floor and around the furnace. Vapors were noted in the basement and throughout the house. Observations during initial response activities indicated that most of the oil had soaked into the cracks in the concrete and alongside the brick retaining walls in the vicinity of the spill. The impacted area was approximately 20 feet by 20 feet.
ACE mobilized equipment to initiate spill clean-up activities, including scrubbing the concrete floor and brick walls with degreaser, removing previously place sorbent material, installing a vapor extraction fan to remove vapors from the affected area (and prevent migration into the house), and also conducted an application of microbes to assist with vapor issues. The MDE directed additional work to investigate soils beneath the concrete slab. Initially, soil cores were conducted through the concrete floor for the collection of field readings. The results of the field survey detected elevated readings as high as 900 parts per million by volume (ppm-v). Based on the elevated readings, soil excavation activities were planned.
Ace initiated soil excavation activities including breaking up the concrete and hand digging impacted soils beneath the foundation. A total of 8.8 tons of impacted soil was excavated and properly disposed. A total of five post-excavation samples were collected for analysis. Based on the analytical results, case closure was recommended and the case was closed.product and/or dissolved-phase recovery.