Soil bioremediation projects

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Here are a few soil bioremediation projects utilizing Biodyne's products and services.

Asphalt Plant Diesel Contaminated Soil
This project involved approximately 6000 yd³ of diesel contaminated soil from an asphalt paving company. A 200' x 400' treatment cell with a 5' berm was constructed. The soil was placed into the treatment cell in two 1.5' lifts.
The microbes were grown on-site in "bug motels" in volumes sufficient to deliver no less than 100,000 cfu/gram of soil. The inoculum and mineral nutrients were added to water in a water wagon and delivered onto the soil.
The soil was aerated with a variety of equipment including discs, scarifier on a grader & soil stabilizer equipment. While flooding extended the treatment time, TRPH dropped from >4000 ppm to <5 ppm in approximately 12 months.

Asphalt Plant Diesel Contaminated Soil
Approximately 1200 yd³ of power screened, diesel contaminated soil from an asphalt paving company was placed in the treatment area in 1' to 1.5' depth. A spray irrigation system was constructed around the perimeter of the treatment area.
The microbial inoculum was grown on-site. The microbes and mineral nutrients were added to a water tanker and delivered by connecting the truck's delivery pump to the irrigation system.
The soil was mixed and aerated using a Bomag soil stabilizer. Not only was the TRPH reduced from >3500 ppm to <5 ppm in approximately 11 months, but underlying groundwater contamination was reduced to the point of no further action.

Fuel Tanker Highway Spill
Approximately 1000 yd³ diesel contaminated soil resulted from an overturned fuel tanker in a South Carolina highway accident. The soil was excavated and taken to a nearby farmer's field where the soil was placed in three windrows.
The microbial inoculum was grown on-site. The microbes and mineral nutrients were delivered using a hand-held wand connected to a mobile sprayer.
The soil was mixed by turning with the backhoe. The TRPH in the very clayey soil was reduced from >3300 ppm to <50 ppm in 12 months.

Gas Station Storage Tank Spill
Approximately 1000 yd³ diesel contaminated soil was excavated from around an underground fuel storage tank at an Ohio convenience store/gas station. The soil was excavated and initially landfarmed with a plow, then later transferred to an asphalt parking lot where it was placed in windrows for bioremediation.
The microbial inoculum was grown on-site. The microbes and mineral nutrients were delivered using a hand-held wand connected to an agricultural sprayer pulled behind a pickup truck. The soil was mixed/aerated immediately after spraying, initially with a plow, then with a windrow compost mixer.
The switch from landfarming to windrow mixing coupled with intervening winter months extended the project. Although some of the soil was incinerated to free up the property, TRPH levels in much of the soil were reduced from >4000 ppm to acceptable levels.

#2 Fuel Oil Pipeline Leak
Approximately 5000 yd³ diesel contaminated soil resulted from an underground #2 fuel oil pipeline leak at a South Carolina Public Works facility. The soil was excavated and staged nearby where the soil was placed on liners in windrows that were approximately 5' high and 16' across and some as much as 300' long.
The microbial inoculum was grown on-site. The microbes and mineral nutrients were placed in a 300-gallon polyethylene tank carried on a pickup truck and delivered using a hand-held wand connected to a gas power sprayer. The soil was mixed/aerated immediately after spraying using a compost mixer.
The soil was inoculated and mixed nearly once a week for twenty weeks, then allowed to sit over the winter months. The TRPH in the extremely clayey soil was reduced from >2000 ppm to <50 ppm in 12 months, notwithstanding almost no mixing and aeration during the last 6 months of the project.

Landfill Contaminated Soil Treatment Program
Petroleum contaminated soils resulting from a variety of origins were treated biologically at a county landfill facility as a pilot program over a three-year period. The soil was treated in a specified portion of the landfill and the resulting clean soil was ultimately used as clean cover material.
Since contaminated soil deliveries were sporadic, soils were stockpiled until enough had accumulated to treat. The microbes and mineral nutrients were placed in a water wagon or agricultural sprayer for delivery onto the contaminated material.
The soil was mixed and aerated regularly using a bulldozer. When the TRPH levels in the treated piles dropped to acceptable levels, the soils were used as cover thus allowing space for new contaminated soil. Most contaminated soils had low TRPH values, thus average treatment time was usually < 3 months.

Oil Pipeline Transfer Station Leak
About 100 yd³ of crude oil contaminated soil resulted from a pump seal leak at an oil pipeline pumping facility. Extensive underground piping in the area limited the amount of the contaminated soil that was excavated. This excavated soil was landfarmed. The remaining soil was treated in place.
The microbial inoculum was grown on-site. The microbes, mineral nutrients and surfactant were delivered using a 300-gallon polyethylene tank and pump connected to an irrigation system. The microbe/mineral mixture was delivered over the contaminated site from oscillating irrigation spray heads.
The excavated soil was landfarmed in a 1' lift approximately 30' wide and 150' long using a garden tiller to mix/aerate the soil. The TRPH in the excavated soil was reduced from >12,000 ppm to <50 ppm in 9 months, while the TRPH in the in situ soil was reduced to acceptable levels in about 12 months.

Underground Oil Transport Pipe Leak
About 200 gallons of crude oil leaking from a cross-Florida transport pipe contaminated surface soil in remote areas of the Everglades. The leak was pinpointed and repaired quickly and the contaminated surface soil was treated biologically by surface spraying and hand mixing where possible.
Because of the remote location of the contaminated site, the microbial inoculum was grown elsewhere, placed into a 300-gallon polyethylene tank and brought to the site via 4-wheel drive pickup truck.
A microbe/mineral nutrient/surfactant mixture was delivered through a hose using gravity feed. The inoculum was worked into the soil using a shovel. Visits to the site ranged between 3 and 4 weeks. The soil discoloration disappeared and the TRPH levels dropped to acceptable levels in approximately 4 months.