Bio-Rem Case History

A New Jersey Resort/Hotel was preparing to expand their facilities. The engineering contractor found a 10,000-gallon fuel oil underground storage tank installed by a previous owner which, once removed, was found to have released product into the surrounding soils and ground water. The contaminated soils were excavated down to ground water level of 8 to 10 feet. With more than 2 feet of free petroleum product in the ground water, further definition was necessary, so the excavation was backfilled, and wells were installed to delineate the contamination and to remove the free product.

Concurrently, the city had initiated the repair of some nearby underground municipal steam lines, requiring the ground water level to be drawn down from 8 feet to 18 feet below ground surface. This draw down resulted in a smearing of the soil with free product, effectively rendering any product recovery system useless. In addition, the resort owner had an aggressive timetable for the expansion project, which included the installation of extensive underground utilities in the affected area, as shown in the diagram.

Bio-Rem, Inc.’s Augmented In-Situ Subsurface Bioremediation ProcessÔ was selected to treat the contaminated soil and ground water. Because the product, Bio-Rem formulation H-10, does not require supplemental oxygen or nutrients to successfully degrade petroleum products in soil and ground water, it was especially well suited for the remediation of this site. Bio-Rem H-10 was propagated on site and applied to the array of borings installed by

the engineer in the affected area. A vapor-space survey using a Photo Ionization Detector (PID) was performed to determine baseline levels at the monitoring points.

As a means of field monitoring, routine PID testing was performed on several of the borings and wells. (Some borings were no longer accessible due to construction.) At several of the chosen points, the PID levels increased over the course of the first few weeks. The elevated PID levels indicated the product was working effectively, as the heavier hydrocarbons in the fuel oil were being broken down into lighter constituents with a higher vapor content. (See the graph below.) The PID readings dropped rapidly over time, indicating biodegradation was proceeding. Additionally, the NJDEP requested that methane monitoring be done concurrently with the PID monitoring, to determine whether any anaerobic bacterial degradation was occurring. All methane readings indicated non-detect levels.

After only one month, the soil was extensively investigated for evidence of free product, and soil contaminants exceeding Impact to Ground Water Criteria, using twenty-three (23) GeoProbeÒ locations in the former tank field. No free product was found in the soil. Contaminant levels were so low that the NJDEP issued No Further Action for soil at the site.

Two months after treatment was completed, the nearby dewatering operation was discontinued, and ground water level recovered to its normal depth. Water samples were taken from all monitoring wells to measure contaminant levels, and to determine whether the plume had spread beyond the original location. Testing results confirmed that all wells were in compliance with Class II-A Ground Water Quality Criteria (GWQC) except for one monitoring well with elevated Benzene of five (5) Parts per Billion. (GWQC for Benzene is 1 PPB.) The NJDEP granted that no more active remediation needed to be done on the ground water, and that a Classification Exception Area be applied.

The ground water will be tested again within the month, and Benzene levels are expected to fall below Class II-A GWQC, at which time the case will be closed.

Complete bioremediation of this site was expected to take nine (9) months. Soil was clean less than two (2) months after application of H-10, and ground water is expected to take a total of five (5) months to reach Class II-A ground water standards. Due to the non-intrusive effectiveness of Bio-Rem H-10, the owner was able to continue the construction project during the remediation process without any delays or obstructions to progress.