PROJECT B-1
Ex Situ Treatment Projects (in Lifts or Bio-Piles)
Bulk Fuel Oil Terminal, Natick, MA
PROBLEM:
Petroleum hydrocarbon release during reconstruction of large bulk fuel oil terminal
A release of petroleum hydrocarbons to the environment was discovered
in June of 1996, during reconstruction of a large bulk fuel oil
terminal located in Natick, Massachusetts. The release was discovered
during the decommissioning and removal of underground storage tanks
(USTs) and above ground storage tanks (ASTs), ranging in size from 250
gallon capacity to 20,000 gallon capacity. The hydrocarbon components
in the soils were identified as No. 2 fuel oil and lubricating oil, at
concentrations which exceeded applicable Massachusetts cleanup
standards. Volatile organic compounds were not identified as
constituents of concern.
SOLUTION:
Ex situ bioremediation of contaminated soil, using MicroSorb® SC, Nutrients and Biocatalyst
Ex situ bioremediation of the contaminated soil was selected as
the most cost-effective response action. Approximately 3,000 cubic
yards of petroleum hydrocarbon-contaminated soils were placed within a
single, fully contained biotreatment bed, constructed solely of 6 ml
polyethylene bottom and sidewall liners, hay bales, and
silt/construction fencing to minimize construction costs associated
with piping, sumps, pumps, stock tanks, etc. Five control soil samples
were obtained from selected areas within the biotreatment bed and were
analytically tested to determine total petroleum hydrocarbon (THP)
concentrations prior to biological treatment. Since December, 1996, 25
pounds of MicroSorb® SC, MicroSorb®
Nutrients, and 165 gallons of MicroSorb® Biocatalyst
were combined with non-chlorinated water and directly applied to the
contaminated soil. Soil sampling and analytical testing were performed
periodically to monitor the efficacy of the biological treatment.
The results of the analytic testing are presented in the following table:
ANALYTICAL TEST DATA - TPH IN SOIL
(December 1996 through October 1997)
|
| Sample Station |
Sample Date |
TPH
(in ppm) |
Percent
Reduction |
Remarks |
| BTC-A |
12-2-96 |
5,100 |
- |
Control sample/before treatment |
| |
6-25-97 |
3,800 |
26 |
reduction in TPH |
| |
10-8-97 |
1,500 |
71 |
further reduction of TPH |
| BTC-B |
12-2-96 |
4,200 |
- |
Control sample/before treatment |
| |
6-25-97 |
3,300 |
22 |
reduction in TPH |
| |
10-8-97 |
1,430 |
66 |
further reduction of TPH |
| BTC-C |
12-2-96 |
5,500 |
- |
Control sample/before treatment |
| |
6-25-97 |
3,400 |
38 |
reduction in TPH |
| |
10-8-97 |
1,890 |
66 |
further reduction of TPH |
| BTC-D |
12-2-96 |
4,400 |
- |
Control sample/before treatment |
| |
6-25-97 |
2,500 |
43 |
reduction in TPH |
| |
10-8-97 |
1,340 |
70 |
further reduction of TPH |
| BTC-E |
12-2-96 |
3,100 |
- |
Control sample/before treatment |
| |
6-25-97 |
1,300 |
58 |
reduction in TPH |
| |
10-8-97 |
1,440 |
54 |
see Note below |
Average
Reduction |
|
4,460 |
65 |
overall reduction in TPH |
Note: Slight increase in TPH concentrations attributed to
presence of fatty acids which accumulate as natural byproducts of
bioremediation
RESULTS:
Overall average reduction in TPH levels of 65%: cost-to-date approximately $9 per cubic yard
The results of the analytical testing over the 10-month period since
treatment began indicated an overall average reduction in TPH levels
of 65%. Over 700 cubic yards of treated soil meet the most stringent
Massachusetts cleanup standards and were suitable for reuse
on-site. Estimated costs for disposal of the soil and a soil recycling
facility was approximately $60. per cubic yard. The cost-to-date for
the biological treatment of the soil has been approximately $9 per
cubic yard.
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