Health and Educational Services
CommTank was hired to remove a 1,000-gallon underground storage tank (UST) containing fuel oil from the property of Health and Educational Services in Salem Mass. During the removal process it was discovered that the tank had been leaking while in operation. In order to evaluate the subsurface conditions in the area of the former UST, the LSP recommended that CommTank advance four soil borings. Based on the results, we were then hired to conduct soil excavation activities within the area of the former UST, and the site was reported to the Massachusetts Department of Environmental Protection (MADEP).
In order to evaluate subsurface conditions down gradient of the former leaking UST, twelve monitoring wells were installed on the neighboring property. Based on measurements taken from the monitoring wells, groundwater was determined to be 20 feet below existing-grade. The extent of fuel oil impact to soil and groundwater was delineated, and the results showed fuel oil migration via the groundwater, to the neighboring property. To handle this migration the remediation plan consisted of installing a number of vertical inoculation wells in the area of the petroleum-impacted soil and groundwater on both properties. Because of the geological (relatively dense soils) and logistical (beneath a portion of the basement of the neighboring property) constraints, CommTank proposed the use of enhanced fluid recovery (EFR) following the injection of a petroleum surfactant. This method was an ideal remedial alternative for this fuel oil release because of the prevalence of separate phase product. Once the product levels were reduced, CommTank implemented a hydrogen peroxide injection program within the vertical injection well network outlined in the remediation plan. This remedial action was used to "flush" residual absorbed petroleum from the underlying basement soils as well as "polish" and reduce dissolved phase petroleum constituents to concentrations which met or exceeded the current MCP standards.
The following is a summary of services provided for the remediation of the Health and Educational Services site.
1. Removal of the underground storage tank.
2. Evaluation of subsurface soil conditions and groundwater impact.
3. Petroleum contaminated soil excavation and removal.
4. Delineation of the area impacted by the petroleum leak.
5. Installation of recovery wells and injection points.
6. Extraction of contaminants from recovery wells using a high vacuum system.
7. Residual contaminants oxidized using a hydrogen peroxide and iron solution.