DSHW-2007-008941 - 0901a06880162e0c

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

RE: Revised Work Plan for Corrective Measure Pilot Test to Evaluate Ex-Situ Remediation of Perchlorate Contaminated Soil
ATK Launch Systems - Promontory Facility, EPA I.D. #UTD009081357

Dear Mr. Gosen:

The Division of Solid and Hazardous Waste has completed its review of ATK’s new proposal for the remediation of the perchlorate contaminated soil piles at E-501. The new proposal modifies
the Corrective Measure Pilot Test that was approved on October 5, 2005. Based on the recent information provided by ATK, it is believed that the soil piles were not sufficiently anaerobic
during the previous test to promote degradation of the perchlorate.

The new work plan that was submitted focuses on the remediation process. The new plan for soil remediation is hereby approved. However, ATK must comply with all of the other aspects
of the original Corrective Measure Pilot Test. For example, the treatment goal, evaluation of the mobility of metals, method for determining if the treatment goal has been met, and
the reporting requirements remain in effect as stated in the approved Corrective Meaure Pilot Test Work Plan (September, 2005).

If you have any questions, please contact Jeff Vandel at [phone].

Sincerely,

ORIGINAL DOCUMENT SIGNED BY DENNIS R. DOWNS ON 7/20/07

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

DRD\JV\tm

c: J.E. Wells, ATK Launch Systems
Richard White, EarthFax Engineering, Inc.

July 20, 2007

TN200700806
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

Richard W. Sprott
Executive Director

DIVISION OF SOLID AND HAZARDOUS WASTE

Dennis R. Downs
Director

JON M. HUNTSMAN, JR.
Governor

GARY HERBERT
Lieutenant Governor