Micro-Bac International, Inc.
#2 Fuel Oil In Situ Bioremediation
Project A Massachusetts residential property identified #2 fuel oil underneath the basement floor. The oil release came from a leaking above-ground storage tank located next to the foundation. A subsequent site investigation found TPH (total petroleum hydrocarbon) levels as high as 4,500 ppm in the soil underneath the basement floor.
Treatment Cost estimates to remove the foundation and basement floor, as well as the contaminated soil, ranged from $150,000 to $200,000. The owner selected bioremediation as an alternative solution for elimination of the fuel oil contamination. A series of six-inch diameter holes were drilled through the basement floor, and M-1000H*®, OSNF #1 nutrients and water were metered into the holes to assure thorough penetration and proper soil saturation. Moisture and nutrient levels were monitored and maintained. After five months, the TPH levels were reduced to less than 500 ppm, except in one small area where hard-pan soil lenses prevented proper saturation. The concrete floor was removed in this area, the soil broken up, and the area treated with bacteria and nutrients.
Results The contaminant levels in the problem area immediately started to drop following treatment, and by the end of seven months, that area also showed TPH values well below the target 500 ppm. The next month, confirmation testing showed that all areas complied with state clean-up standards. The total cost to remediate the site was less than $25,000.
TPH Results of Soil Contaminated with No. 2 Fuel Oil
| Date | Sampling Locations | |||||
|---|---|---|---|---|---|---|
| S-1 | S-2 | S-3 | S-4 | S-5 | S-3 | |
| 6/13/94 | 4,000 | ND | 2,600 | ND | 4,000 | 13 |
| 1/27/95 | BBP | BBP | BBP | BBP | BBP | BBP |
| 3/12/95 | 1,632 | 2,378 | 387 | 717 | 1,028 | ND |
| 4/6/95 | 1,632 | 1,270 | 240 | 800 | 249 | 5.7 |
| 7/25/95 | 349 | ND | ND | ND | ND | ND |
| 10/5/95 | 230 | 590 | ND | ND | 470 | 370 |
- BBP: Began bioremediation program
- ND: Not detected
Notes:
- All samples collected after the bioremediation program began (1/27/95) were tested for total petroleum hydrocarbons (TPH) using EPA method D-3328 (GC-FID). All reported concentrations shown above are in parts per million (ppm).
- Only one soil sample, collected on 7/25/95 at the S-1 location was tested for TPH to give a general indication of the bioremediation progress. The sample collected was taken after the soil (from existing grade to two feet below) under the concrete floor was roto-tilled.
- Soil samples collected on 10/5/95 are the results of the final testing program to determine if the average concentration of the remediated soil is below the Method 1 GW-1/S-1 of 500 ppm for TPH.
Information courtesy of CJH Environmental, Inc., Stoughton, MA.