DSHW-2005-008903 - 0901a0688016644c

Paul Hancock, Manager
Environmental Remediation
ATK Thiokol Inc. – Promontory
P.O. Box 707
Brigham City, UT 84302-0707

RE: Review of the Pilot Test Work Plan for Perchlorate Remediation at the ATK Thiokol – Promontory Facility, EPA ID #009081357

Dear Mr. Hancock:

The Division of Solid and Hazardous Waste has completed its review of the Pilot Test Work Plan that was prepared by Kleinfelder Inc. and submitted to our office on June 28, 2005. According
to the Work Plan, the objective of the Pilot Test is to assess an in situ method for the remediation of groundwater contaminated with perchlorate. The remediation method involves the
application of a “vapor amendment” consisting of ethyl acetate and nitrogen into the saturated zone via a sparging well.

The Thiokol Liquid Thermal Treatment Area (M-136 Burn Grounds) Post-Closure Permit requires that corrective action be taken for contaminated groundwater at the facility. It is stated
in the Work Plan that if the Pilot Test is successful, this technology could be used to remediate groundwater contaminated with perchlorate at the Promontory and Bacchus facilities.

In a letter addressed to you dated July 6, 2005, the Division of Water Quality approved the construction and operation of the sparge well (classified as a Class V injection well) in
accordance with the Utah UIC Program Rules. The Pilot Test Work Plan is hereby approved, provided that manganese is added to the list of analytes that will be monitored for before,
during and after the vapor amendment is injected.

Please be advised that contaminated groundwater that is accumulated through the installation or operation of the sparging well must be managed as hazardous waste due to the listed constituents
that are contained in the groundwater. In addition, the sparge well must be constructed and

maintained in accordance with applicable components of the RCRA Groundwater Monitoring Technical Enforcement Guidance Document (Post-Closure Permit condition VI.E.1.).

If you have any questions regarding this issue, please contact Jeff Vandel of our office.

Sincerely,

ORIGINAL DOCUMENT SIGNED BY DENNIS R. DOWNS ON 8/3/05

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

DRD\JV\ts

c: Lloyd C. Berentzen, M.B.A., Health Officer/Director, Bear River Health Dept.
Nancy Morlock, USEPA Region VIII

File to: ATK Thiokol Inc. - Promontory

August 3, 2005
Page 2

August 3, 2005

TN200501039.doc
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