DSHW-2015-003155 - 0901a068804f9050

Division of
Solid and Hazardous Waste
Fffi 1 8 2015
Orbital ATK %
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February 12,2015
8200-FY16-002
Scott T. Anderson, Director
Department of Environmental Quality
Division of Solid and Hazardous Waste
ATTN: Jeff Vandel
P.O. Box 144880
195 North 1950 West
Salt Lake City, Utah 84114-4880
RE: New SWMU # 682 Assessment Report, ATK Launch Systems Inc. Promontory Facility, EPA
ID#UTD009081357
Dear Mr. Anderson,
A new Solid Waste Management Unit (SWMU) was identified at the ATK Launch Systems
Promontory Facility. Notification of the new SWMU was provided in a November 6,2014 letter
to your office. The new SWMU is due to a perchlorate release at building M-115 and has the
designation of #682. A spill notification letter to the Division of Solid and Hazardous Waste
was sent July 28,2014 describing a release of approximately 100 gallons of water containing
perchlorate. Following the spill, excavations were conducted in order to remove the
contaminated soil. After the excavations, samples were collected to determine if the
concentrations were below levels of concern. It was found that the contamination had traveled
deeper into the soil profile; however, a buried building electrical conduit would not allow for
additional excavations or deeper sampling. Figure 1 shows the general area of the spill and the
perchlorate samples that were collected prior to the excavations and after the final excavation.
Options for further remediation of the spill are limited due to the buried conduit. One option
that was investigated was in situ biological treatment. Plans were developed to perform bench
test treatment using actual soil and perchlorate from the spill site in a column test. Samples were
collected from the area of the highest concentrations in the excavation as noted on Figure 1.
When these soil samples were analyzed prior to the testing it was found that the concentration
had dropped from approximately 1100 ppm to 10 ppm. The ATK onsite weather station has
logged that rain storms with a total of approximately 4.5 inches of precipitation had occurred
since the last excavation resulting in the potential for leaching and attenuation of the perchlorate
to occur. However, the bench testing was still conducted using the 10 ppm concentration in the
soil. Bio-reactor effluent from our onsite perchlorate treatment facility was used as an electron
donor to seed fresh amounts of the same donor material used in the reactor. During the bench
Orbital ATK, Inc. • 45101 Warp Drive, Dulles, VA 20166 • 703-406-5000
test it was found that there was an initial reduction of perchlorate but that it then it
appeared to stall. This indicated that the donor may not have been in high enough
concentrations
to totally degrade the perchlorate. Additionally, the perchlorate moved through the
column along with the added donor. Results of the testing are found in Attachment 1.
Additional bench testing is planned to determine if it is feasible to treat perchlorate in
situ. This will likely include using the bioreactor effluent mixed with a more persistent
donor such as lecithin or emulsified vegetable oil.
Current Exposure Risk Evaluation
Ground Water
There are three groundwater monitoring wells in the down gradient area of the spill site.
All were drilled at a significantly lower surface elevation than the hillside location of M-
115. These wells are intended to monitor any perchlorate originating from M-115 since it
is a historic perchlorate source area from motor washout in the 1960s. Figure 2 shows
the location of these wells. Based on these elevations, groundwater at well B-10 is 286
below M-115 in a perched aquifer. The other two well are completed in the regional
aquifer with water elevation at B-10 544 feet lower than M-115 and well B-l 566 feet
lower. HYDRUS modeling of the spill site will be conducted to determine where the
perchlorate has moved assuming current and projected normal rain fall. This will allow a
conclusion to be made on the potential for the perchlorate to reach groundwater.
Surface soils are currently less than the PRG residential values of 55 ppm, due to a
combination of the soil removal down to the electrical conduit and subsequent rainfall.
The HYDRUS model will be used to assess the depth at which the residual perchlorate
will move. Based on this HYDRUS modeling, other potential exposure pathway can be
assessed including excavation, plant uptake and ecological exposures.
The additional HYDRUS modeling information and risk assessment will be provided in a
follow-up report. If you have questions, or need additional information, please contact
Paul Hancock at [phone].
SoU
Sincerely,
George Gooch, Manager
ATK Launch Systems Environmental Services
Figure 1
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Location of Down Gradient Monitoring Wells at M-115
ATK Launch Systems Promontory Facility
M-115 Soil
Baseline data
sample
duplicate
triplicate
Attachment 1
ATK Launch Systems Nov. 5, 2014 Perchlorate Treatment Bench Test Data
Perchlorate Moisture Perchlorate
Day 3
Top Layer
Middle Layer
Bottom Layer
wet wt ppm
9.94
9.58
9.38
wet wt ppm
1.05
5.23
15.90
% Moisture
4.6%
4.6%
4.6%
ave
rsd
2s
% Moisture
10.4%
8.8%
6.9%
8.7%
dry wt ppm
10.42
10.04
9.83
10.10
2.9%
5.9%
dry wt ppm
1.17
5.73
17.08
% of Baseline
11.6%
56.8%
169.1%
Mass balance (mg)
1.04
1.00
0.98
% of total
34.4%
33.1%
32.5%
sum 3.03
Mass balance (mg)
0.12
0.57
1.71
100.0%
% of total
3.9%
18.9%
56.4%
Average
33.3%
Reduction
29.5%
14.4%
-23.0%
sum 2.40 79.2%
Day 7
Top Layer
Middle Layer
Bottom Layer
wet wt ppm
1.00
6.22
14.20
% Moisture
9.2%
8.4%
7.9%
8.5%
dry wt ppm
1.10
6.79
15.42
% of Baseline
10.9%
67.2%
152.7%
Mass balance (mg)
0.11
0.68
1.54
% of total
3.6%
22.4%
50.9%
Reduction
29.7%
10.9%
-17.6%
sum 2.33 76.9%
Day 11
Top Layer
Middle Layer
Bottom Layer
wet wt ppm
2.00
6.08
13.70
% Moisture*
8.3%
8.3%
8.3%
dry wt ppm
2.18
6.63
14.94
% of Baseline
21.6%
65.7%
148.0%
*moisture tesing not complete, estimated value
Mass balance (mg)
0.22
0.66
1.49
% of total
7.2%
21.9%
49.3%
sum 2.38
Reduction
26.1%
11.4%
-16.0%
78.4%