DSHW-2007-008303 - 0901a06880162899 (4)

David P. Gosen, P.E.
Director, Environmental Services
ATK Launch Systems – Promontory
P.O. Box 707
Brigham City, UT 84302-0707

RE: Response to Comments on the Pilot-Test Work Plan to Evaluate Enhanced Anaerobic Bioremediation of Perchlorate and Solvent Contaminated Groundwater, ATK Launch Systems - Promontory
Facility, EPA I.D. #UTD009081357

Dear Mr. Gosen:

This letter is in regard to ATK’s plan to conduct a pilot test in the M-136 Burn Ground area in order to evaluate the in-situ groundwater treatment method as described in the Work Plan
referenced above. The Division of Solid and Hazardous Waste’s review of the original Work Plan generated a small number of questions and comments. These questions and comments were
provided to you on November 8, 2006.

A revised Work Plan and responses to the questions and comments were received from EarthFax Engineering on December 19, 2006. The Division has reviewed the revised Work Plan and responses
to comments that were submitted. Based on our review, it appears that our concerns have been addressed.

The ATK Liquid Thermal Treatment Area (M-136 Burn Grounds) Post-Closure Permit requires that corrective action be taken to cleanup contaminated groundwater at the facility. If the Pilot
Test is successful, this technology may be used to comply with this requirement.

In addition, based on internal communication with the Division of Water Quality (DWQ), Underground Injection Control (UIC), an “Authorization by Rule” status for the operation of the
injection well that will be utilized during the pilot test is forthcoming.

The Pilot Test Work Plan is hereby approved. Please notify Jeff Vandel of the Division seven days prior to implementing the work plan to allow for potential oversight of the effort.
Jeff may be contacted at [phone].

Sincerely,

ORIGINAL DOCUMENT SIGNED BY DENNIS R. DOWNS ON 1/23/07

Dennis R. Downs, Executive Secretary
Utah Solid and Hazardous Waste Control Board

DRD\JV\tm

c: Lloyd C. Berentzen, M.B.A., Health Officer/Director, Bear River Health Dept.
Carl Daly, USEPA Region VIII
Paul Hancock, ATK
Richard B. White, Earthfax Engineering

File to: ATK Launch Systems - Promontory

January 23, 2007
Page 2

January 23, 2007

TN200700100
288 North 1460 West • PO Box 144880 • Salt Lake City, UT 84114-4880 • phone [phone] • fax [phone]
T.D.D. [phone] • www.deq.utah.gov

State of Utah

Department of Environmental Quality

Dianne R. Nielson, Ph.D.
Executive Director

DIVISION OF SOLID AND HAZARDOUS WASTE
Dennis R. Downs
Director

JON M. HUNTSMAN, JR.
Governor

GARY HERBERT
Lieutenant Governor