Accelerating Aerobic Biodegradation of GRO/DRO: A Five-Year Study (PDF)
Gasoline Range Organics (GRO) and Diesel Range Organics (DRO) contaminated the aquifer underlying a warehouse/equipment storage facility in Homer, AK. This contamination originated from leaks in underground storage tanks located in the northern section of the site. Groundwater flow at the site is controlled in large part by a finger drain running through the facility. This finger drain, cut four feet into the ground and filled with coarse gravel, is responsible for the majority of contaminant migration. This paper presents the results of a 5-year treatment program conducted by Hart Crowser using Oxygen Release Compound (ORC®). The goal of the treatment program was to remediate the entire range of hydrocarbon contamination (GRO and DRO). Treatment was focused along the length of the finger drain. Initially, Hart Crowser conducted a five-month pilot study to determine the ability of ORC to accelerate the aerobic biodegradation of GRO and DRO. After a successful pilot program, Hart Crowser went on to a full-scale application. At the beginning of the full-scale treatment, DRO concentrations averaged 87 mg/L and GRO concentrations averaged 14.5 mg/L. Benzene, toluene, ethylbenzene, and xylene (BTEX) concentrations averaged 4.4 mg/L. After approximately 5 years of treatment, DRO concentrations decreased by 90%, to an average of 8.3 mg/L. GRO concentrations decreased by 91%, to an average of 1.3 mg/L, and BTEX concentrations decreased by 89%, to an average of 0.5 mg/L.