Underground Heating Oil Tank Removal and Soil Evaluation at a Rural Property

At a rural residential property in central Virginia, Pollard Environmental evaluated conditions around an existing (in-use) heating oil underground storage tank after an inspection identified petroleum-saturated soils next to the tank. The removal was required to better understand remaining environmental conditions at the property and to assess risk to human health and the environment.

During the investigation and subsequent underground oil tank removal, the team observed soil conditions that appeared consistent with a previous heating oil release documented at the same location under an earlier regulatory case. Records indicated that the prior case had been closed after corrective action in 2012, including soil over-excavation and a groundwater investigation. Based on field observations during the current tankclosure process and excavation, the remaining impacted soils appeared to be associated with that earlierrelease rather than a newly identified condition.

Pollard Environmental carried out additional soil excavation below the tank area and extended the excavation vertically to the bedrock surface at approximately 11.5 to 12 feet below grade. This deeper over-excavation was performed to remove petroleum-contaminated material to the extent practicable and to better define the remaining subsurface conditions. Sampling and laboratory analysis showed that residual petroleumconcentrations in the remaining soils were well below petroleum-saturation levels, indicating that risk to theenvironment is low.

Although the soil results were favorable, the property also includes a nearby domestic water supply well, which remains the main human health consideration because of its proximity to the historical release area. Available sampling and analytical data indicated no identified impact to that well at the time of evaluation. Even so, because groundwater is the most relevant potential exposure pathway at this location, a current groundwater investigation was considered warranted to more fully assess any remaining risk to human health.

This project shows the importance of careful underground heating oil tank removal, soil evaluation, and practical environmental site care at residential properties with a known release history. By combining targeted excavation, confirmation sampling, and attention to the nearby water supply, the work helped clarify site conditions, reduce uncertainty, and support informed next steps for protection of human health and groundwater quality.