Case Studies

Case Study

Contaminated Soil Remediation
Effective Treatment of Volatile Petroleum Hydrocarbons in Soil
Site: Service Station

former mill

Table 1

Table 2

 

Site Summary

Operations at a service station in Massachusetts resulted in soil contaminated with volatile petroleum hydrocarbons (VPH) at concentrations exceeding the State’s risk-based cleanup standards. Fraction hydrocarbon analysis indicated the presence of weathered gasoline at concentrations over 1,000 mg/kg for each fraction. In particular, VPH concentrations for the C3 to C8 fractions were 1,130 mg/kg. A remedial plan was implemented deploying in-situ chemical oxidation via RegenOx™ to effectively destroy VPH in the subsurface. RegenOx was applied at the site in December 2005 using seven injection points within the source area.

Remedial Approach

Objective: Reduce VPH concentrations in source area soil to the cleanup goals. The pre-treatment contaminant concentrations and cleanup goals are shown in Table 1. A total of 1,200 pounds of RegenOx was applied to the vadose zone from 15 to 25 feet below ground surface. Approximately 170 pounds was applied into each injection point.

Results

See Table 2.

Conclusion

The weathered VPH contaminant mass was removed from the treatment area soil after only one RegenOx application. Post-remediation 5 months after application found no detectable VPH fractions in the soil. Follow-up sampling 1 month later confirmed the contaminant removal and site closure was granted by the regulatory agency in December 2006.

Please note that in most cases chemical oxidation typically requires multiple application events to obtain contaminant mass reductions of this magnitude.