DSHW-2012-003152 - 0901a068802ce766

May 2, 2012
8200-FYl 3-007
Scott T. Anderson, Director
Department of Environmental Quality
Division of Solid and Hazardous Waste
ATTN: Jeff Yandel
P.O. Box 144880
195 North 1950 West
Salt Lake City, Utah 84114-4880
Division of
Solid and Hazardous Waste
MAY 0 3 2012
mZ'-0D5l5Z
RE: New SWMU # 680 Assessment Report, ATK Launch Systems Inc. Promontory Facility,
EPA ID# UTD009081357,
Dear Mr. Anderson,
This new Solid Waste Management Unit (SWMU) assessment report for SWMU #680 is
being submitted according to condition VI.H.2 of the Promontory Post Closure Permit.
If you have questions, or need additional information, please contact Paul Hancock at (435) 863-
3344.
Sincerely,
Paul V. Hancock, Manager
ATK Environmental Services
Division of
Solid and Hazardous Waste
MAY 0 3 2012
Assessment Report For New SWMU # 680
ATK Promontory
April 2012
New SWMU # 680
Assessment Report
ATK Promontory
April 2012
Assessment Report for New SWMU # 680 at ATK Promontory
Purpose
This new Solid Waste Management Unit (SWMU) assessment report is being submitted
according to condition VI.H.2 of the Promontory Post Closure Permit.
Background
On January 23, 2012, an inspection of a concrete trench in building M-705 at the
Promontory facility showed that there was a crack approximately two inches wide and
three inches long. This trench routinely receives perchlorate water with a concentration
in the hundreds to thousands of parts per million as part of the treatment processes in the
building. Processes discharging waste water to the trench were stopped and a repair was
made by the following day. The remainder of the trenches were inspected and found to
be in good condition. What caused the crack, how long it existed and what quantity of
perchlorate was released is uncertain.
M-705 is the waste water treatment facility that treats chemical constituents in waste
water from process buildings at Promontory. Waste water at M-705 is pumped and
moved from various process tanks through pipes and concrete trenches. The treated water
is then discharged under a UPDES permit to the receiving stream called Blue Creek. The
building was constructed in 1987 and consists of concrete walls and epoxy coated
concrete floors. M-705 is identified on a map in Attachment 2.
The waste water that is processed through the trench can contain water with thousands of
parts per million of perchlorate and high parts per billion levels of volatile organics used
at the facility typically including acetone, alcohol or citrus based cleaners, and ethyl
acetate.
Since M-705 is an active process building, and the release was underneath the building, it
was not practical or advisable to attempt to recover material or to do further physical
investigation.
Potential Migration Pathways
Given that the release area is under a concrete floor of the building there is no potential
for direct exposure to these constituents. There is a potential for constituents to migrate to
groundwater at the location. The perchlorate contaminated water would have the highest
mobility in the soil, therefore, an evaluation was made by modeling the potential for the
release to migrate to groundwater at the site and travel to the nearest down gradient well.
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New SWMU # 680
Assessment Report
ATK Promontory ,
April 2012
Hydrus Modeling
The potential for a process water release at M-705 to reach groundwater was investigated
using the Hydrus Model. This model is approved by EPA for assessing the soil to
groundwater pathway. Input parameters for the model consisted of the depth to
groundwater and the lithology of a nearby monitoring well J-1:
• estimated static water level at around 35m bgs
• divided the soil profile into four units: 0-lm - silty clay; l-7m - a hardpan type
clay; 7-30m - a clayey sand; 30-35m - a clay.
Additional conservative input parameters included an assumed constant source or head
of water, and no lateral dispersion. The modeled run time was 365 days.
The results of the model indicate that the wetting front would reach 17 meters.,
Attachment 1 contains the output file for this modeling.
While there is uncertainty as to how long the crack in the concrete trench allowed water
to leak into the soil below M-705, 365 days is considered to be a conservative
assumption.
Groundwater Modeling
In the event that the release may have migrated to the groundwater, modeling of the
groundwater at the location was conducted to determine a travel time for perchlorate to
reach the nearest down gradient monitoring well. There are three monitoring wells that
could be considered immediately down gradient of M-705 these are J-1, J-7 and J-8.
The Utah Division of Solid and Hazardous Waste approved groundwater model for
Promontory was used to calculate the travel time. Attachment 2 contains the report
which describes the modeling which was conducted by EarthFax Engineering. The
results of the model indicate that the first well to potentially see an increase in perchlorate
would be J-7 with at travel time of 10786 days or approximately 30 years.
Recommendations
Based on the results of this SWMU assessment, it does not appear likely that the release
would impact groundwater and if it did the time to reach a monitoring well and then
migrate to a potential exposure location such as pipe springs would be well in excess of
30 years. The ongoing groundwater monitoring program at the facility would detect any
significant increase of perchlorate or other constituents. These potential increases would
be reviewed to determine any impact to the results of the groundwater risk assessment
now in progress at the facility. Therefore, no fiirther action is recommended at the site.
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New SWMU # 680
Assessment Report
ATK Promontory
April 2012
The following observations have been made of stainless steel corrosion in the
Promontory monitoring wells.
• While sampling the wells with stainless steel screens, the purge water typically
has a high amount of particulate with a rusty red appearance, clearly indicating
corrosion. The samples are not filtered prior to collection in nitric acid fixed
bottles for analysis.
• Dedicated stainless steel pumps in the wells have stopped functioning after a few
years and when pulled they are highly corroded. The corrosion has been
identified as the cause of the pump malfiinction.
• In 2006, as part of a pilot test of perchlorate remediation, a down-hole camera
was placed in well B-6 to determine if corrosion was present in the well screens.
Heavy layers of corrosion were observed and subsequently the well was cleaned.
A comparison was made of the analytical data between the wells constructed with. PVC
screens with wells containing stainless steel screens. From this data it is evident that
corrosion of the stainless steel is the source of the high chromium and molybdenum. This
comparison is found in Attachment 1.
Investigation Plan
The monitoring wells using stainless steel screens were installed in phases starting with
the D series wells in 1986, followed by the A, B, C, E, F and LF series. The amount of
corrosion could be both a function of age and also the groundwater total dissolved solids
in the well. These variables will be part of the investigation. It is also possible that iron
fouling bacteria could be a factor to the corrosion; however, this is more difficult to
establish or investigate.
In 2007, prior to the start of a vegetable oil injection pilot test, several of the Diseries
wells screens were cleaned using a standard drinking water well cleaning process to
remove potential corrosion. While corrosion in these wells was not visually confirmed, it
3 I P a g e
New SWMU # 680
Assessment Report
ATK Promontory
April 2012
was determined to be an important precaution to ensure representative samples were
collected.
ATK has since procured a down hole camera that will be used to inspect the conditions of
the well screens in this investigation. The wells that will be investigated using a down
hole camera are listed in Table 1.
Table 1
Wells to be inspected Using Down-hole Camera
Well Basis for Inspection Notes
D-6 Cleaned in 2007, determine
how quickly corrosion
returns and condition of
oldest wells.
A-10 Next oldest well series; in
area of relatively low TDS
Analytical testing indicates
some of the highest
corrosion
B-4 Older well in area with
increasing TDS
E-6 Moderate aged well, in area
with increasing TDS
F-3 Relatively new well in area
with higher TDS
LF-2 Newest Stainless Steel
Well Series
The down-hole camera allows for videos or pictures to be collected. This visual
information as well as observations recorded in a log book will be assembled for each
well investigated. Once the investigation is completed, inferences can be made as to the
main contributor to the well screen corrosion and then further recommendations.
An unknown condition will be the camera visibility in wells containing high particulates
or rust. Other provisions or plan changes may need to be made in those cases. ATK will
contact the Utah Division of Solid and Hazardous Waste (DSHW) in those situations of
significant deviations in the plan.
4 I 1^ a g e
New SWMU # 680
Assessment Report
ATK Promontory
April 2012 •
Investigation Plan Schedule
Once approval of the plan is obtained from the DSHW the investigation will start. It is
anticipated that the investigation will be ongoing through September of 2012, with a
report completed in October 2012.
5 11^ a g e
New SWMU # 680 Assessment Report
ATK Promontory
April 2012
Attachment 1
Hydrus Model Output
New SWMU # 680 Assessment Report
ATK Promontory
April 2012
Attachment 2
Groundwater Modeling Report
April 16,2012
r ^ -^1 • • EarthFax
EarthFax
Mr. Paul Hancock Engineering, Inc.
P O Box 707 M/S 301 ..^"S^'T n"!'?
Brigham City, UT 84302-0707 ^^^^ SuSeToo
Midvale, Utah 84047
Phone [phone]
RE: Travel Time Calculation for M-705 at the Promontory Facility Fax [phone]
www.earthfax.com
Paul,
At the request of ATK, EarthFax Engineering, Inc. undertook a groundwater model and
contaminant transport simulation at the Promontory Facility in Promontory Utah. This
simulation was In response to a potential release of perchlorate contaminated water at
building M-705.
Model Simulation
The modeling was completed with a software package called Visual Modflow. A module
used in conjunction with Visual modflow for tracking particles called "MODPATH" was
used to project groundwater particles at the Promontory Facility. MODPATH is a particle
tracking post-processing package that was developed to compute three-dimensional
flowpaths using output from steady-state or transient ground-water flow simulations by
MODFLOW. MODPATH uses a semi-analytic particle tracking scheme that allows an
analytical expression of the particle's flow to be obtained within each finite-difference
grid cell. Particle paths are computed in MODPATH by tracking particles from one cell
to the next until the particle reaches a boundary, an internal sink/source, or satisfies
some other termination criterion. Data input for MODPATH is a combination of data files
and interactive keyboard input.
Output from steady-state or transient MODFLOW simulations is used in MODPATH to
compute paths for imaginary "particles" of water moving through the simulated ground-
water system. Once completed, the projected paths were exported in dxf format and
imported into AutoCad for visual display.
The calibrated and approved groundwater flow and contaminant transport model was
used to track particles from building M-705 for a period of approximately 30 years. For
this simulation, the solver was modified to get the model to converge in transient mode
and produce the particle track that was desired.
The particle track initially shows a westward flow path toward Blue Creek. This
migration is shown to take approximately 10620 days before it reaches a north-south
fracture (high conductivity zone). Once in the fracture (or high conductivity zone), the
particles quickly move south. Since Well J-1 is located east of M-705, the model results
in few contaminants reaching J-1. Well J-7 and J-8 are closer to the high conductivity
zone and will see increased contamination from any spill at M-705. However, because
the westward travel time to the high conductivity zone is so great, contaminants do not
reach J-7 and J-8 for 10786 and 10810 days, respectively.
The model does not consider dispersion or other factors, so that the travel path looks
only like a line along the high conductivity zone. Moreover, the fracture or high
conductivity zone is simplified in the model and may not be representative of actual
local conditions.
The attached figures show the particle track from the source (M-705) to the south end of
the facility for a period of 30 years.
Please let me know if you require additional information.
Sincerely,
Kris H Blauer
Hydrogeologist
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