DSHW-2013-002295 - 0901a068803575c0

State of Utah
GARY HERBERT
Governor
GREG BELL
Lieutenant Governor
Department of
Environmental Quality
· Amanda Smith
Executive Director
DIVISION OF SOLID AND
HAZARDOUS WASTE
Scott T. Anderson
Director
March 14, 2013
Robert Ingersoll, Director
Environmental Services
ATK Launch Systems -Promontory
P.O. Box 707
Brigham City, UT 84302-0707
RE: M-136 Burn Grounds
Perchlorate Contamination in Groundwater
UTD009081357
Dear Mr. Ingersoll:
This letter is a follow-up to the meeting that was held with you and members of your staff at our
office on March 6, 2013. During the meeting, a number of issues were discussed that were
originally raised through the 2011 Operation and Maintenance Inspection, the 2011 Storm Water
Management Plan and the 2012 Compliance Evaluation Inspection. Collectively, these issues
revolve around one primary question. Are current operations at the M-136 Burn Grounds
contributing to the rising perchlorate concentrations that have been observed in wells C-1 and
D-4?
As discussed in our meeting, the Division believes it is appropriate for A TK to take the steps
necessary to answer this question so that corrective action may be taken, as needed, to prevent
further degradation of the soil or groundwater at the site. Therefore, the Division is requesting
that A TK submit a plan for approval that identifies the potential sources of perchlorate
contamination that will be investigated at the M-136 Burn Grounds. The plan should provide
details on how the potential source will be evaluated. The plan should also consider compiling
any existing data, as appropriate, as well as the collection of new data from the sampling of soil,
ash and surface water.
The Division also believes it is appropriate for A TK to conduct an interim measure to counteract
the increasing perchlorate trend in groundwater that has been established (local in-situ treatment
has been discussed). A plan for an interim measure may be submitted with the burn grounds
investigation plan or separately.
DSHW-2013-002295
195 North 1950 West • Salt Lake City, UT
Mailing Address: P.O. Box 144880 • Salt Lake City, UT 84114-4880
Telephone [phone] • Fax [phone] • T.D.D. [phone]
www.deq.utah.gov
Printed on 100% recycled paper
In addition, our comments on the Storm Water Management Plan that was submitted in April,
2011 are enclosed with this letter (these are the same comments that were emailed to ATK on
August 8, 2012). It is our opinion that storm water management is a component ofthe primary
question at hand, so a response to our comments and further information on this issue may be
included with the M-136 investigation plan.
If you have any questions, please call JeffVandel at [phone].
Scott T. Anderson, Director
Division of Solid and Hazardous Waste
STA/N/tjm
Enclosure
c: Paul Hancock, A TK, email
Blair Palmer, ATK, email
Grant Koford, EHS, Environmental Health Director, Bear River Health Department
Nancy Morlock, Region 8 EPA
DSHW -2013-002295 2
DIVISION OF SOLID AND HAZARDOUS WASTE COMMENTS
ATK-PROMONTORY
STORM WATER MANAGEMENT PLAN
1) Storm Drainage Design Calculations (M-136 and M-225)): It appears that the rational method is used
in Section 2 and the pertinent calculations for the rational method are also documented at the beginning of
Appendix A. However, at the end of Appendix A, the US Soil Conservation Service TR-55 method is
being presented without any introduction in the main text. Please clarify. We also suggest presenting
maps for areas M-136 and M-225, augmenting the existing Figures 2.12 and 2.2.1, clearly identifying with
different colors the areal extents of the run-on and run-off catchment areas and the accompanying ditches
(run-on) and infiltration areas (run-off).
2a) Run-On for M-136, Rational Method: Please explain what the Time of Concentration (T _C) is for the
25-year storm event. For bare-packed soils and sparsely vegetated soils, as observed at the site, the
literature recommends using a run-off coefficient between 0.2 and 0.4. Please explain your choice of0.5
for the run-off coefficient.
2b) Run-On for M-136: A field visit revealed that at least one culvert entry was "squashed" and also
blocked by vegetation, and did not appear to meet the minimum diameter opening requirement for a 25-
year storm event. Please make sure the run-on control system is in good operating condition at all times.
3) Infiltration Modeling using HYDRUS (M-136): While depth to groundwater is greater than 200 feet,
bedrock appears to be closer to the surface in areas where groundwater monitoring well data is available
(e.g., A-4, A-5, and D-6 with bedrock at a depth of about two feet at well A-5). In addition, it appears that
bedrock in this area may be significantly fractured. This observation appears to invalidate the assumptions
of the 1-D HYDRUS model, which assumes isotropic sandy loams, loamy sands, and sandy clays to 65 m
bgs. The Richards equation, as implemented in HYDRUS, does not seem to be applicable for macropore
flow conditions.
DSHW-2013-002295 1