DSHW-2005-006962 - 0901a06880165374

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

RE: 2005 Groundwater Monitoring at the ATK Thiokol Inc. – Promontory Facility
EPA I.D. #UTD009081357

Dear Mr. Hancock:

This letter is in response to your correspondence dated March 1, 2005 regarding the sampling of groundwater monitoring wells for 2005. The Division of Solid and Hazardous Waste has
reviewed the list of wells that Thiokol has proposed to sample this Spring and Fall. The Division agrees with Thiokol’s selection of wells to sample in 2005; however, there are two
issues concerning groundwater monitoring that may impact the proposed list. These issues are discussed below.

The Division has been contacted by Ray Adams and S.B.I. Engineers regarding groundwater contamination down-gradient of the Thiokol facility and the potential impact to private property.
S.B.I. Engineers have been retained by property owner Mike Stangl to look into this issue. Samples were last collected from private wells on the Adams property in July 2001, and the
Stangl property in May 2002. The Division recommends that private wells on the Adams and Stangl properties be sampled again this Spring. Split samples would be collected by the Division
and analyzed by the Utah Division of Laboratory Services for perchlorate and volatile organic compounds. Sampling of wells on the Adams and Stangl properties this Spring has been discussed
with your staff, and apparently Thiokol is in agreement with this plan.

The other issue that may affect the list of wells to sample this year concerns the groundwater flow and transport models that are currently being produced. The Division recommends that
Thiokol discuss potential data gaps with its contractor. Are there any key areas within the model domain where current data is needed to help characterize hydrologic conditions?

My staff will contact you regarding the details of sampling the Adams and Stangl wells and to inquire about data gaps in the groundwater models. Thank you for your cooperation. If
you have any questions regarding this letter, please contact Jeff Vandel at 538-9413.

Sincerely,

ORIGINAL DOCUMENT SIGNED BY DENNIS R. DOWNS ON 3/22/05

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

DRD\JV\ts

c: Lloyd C. Berentzen M.B.A.., Health Officer/ Bear River Health Dept.
Linda Bowling, USEPA Region VIII

TN200500431
File to: ATK Thiokol Inc. - Promontory

March 22, 2005
Page 2

March 22, 2005

TN200500431.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