DSHW-2011-008602 - 0901a06880274be9

April 12, 2011

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

RE: ATK Responses to Comments
Human Health Risk Assessment Protocol for OB/OD Operations
ATK Launch Systems - Promontory Facility
UTD009081357

Dear Mr. Gosen:

The Division of Solid and Hazardous Waste has completed its review of ATK’s response (dated February 28, 2011) to our second round of comments on the OB/OD Human Health Risk Assessment
(HHRA) Protocol. The additional information ATK has provided appears to adequately address the outstanding issues associated with specific comments 4, 5, 8 and 15.

However, there are a few changes that need to be made to the tables that were submitted with ATK’s last response to comments. These changes are discussed in the enclosed document.
Through the HHRA Protocol review process, it has been understood that the protocol document would be updated once all outstanding issues were resolved. Please make the requested changes
to the tables when updating the HHRA protocol document.

The Division requests that ATK submit the updated HHRA protocol document by May 2, 2011. If you have any questions, please contact Jeff Vandel at [phone].

Sincerely,

ORIGINAL DOCUMENT SIGNED BY SCOTT T. ANDERSON ON 4/12/2011
Scott T. Anderson, Director
Division of Solid and Hazardous Waste

STA\JV\tjm

Enclosure

c: Paul Hancock, ATK Launch Systems
Blair Palmer, ATK Launch Systems
Lloyd Berentzen, MBA, Health Officer, Bear River Health Department
Cheryl Overstreet, Region 8, USEPA

TN201100384 2
Review of ATK Responses (dated February 28, 2011) to DSHW Comments on the Human Health Risk Assessment Protocol for OB/OD Operations
ATK Launch Systems - Promontory Facility

The information presented by ATK in its last response to Division comments appears to adequately address the outstanding issues associated with specific comments 4, 5, 8 and 15. However,
it appears that some of the information presented in the three tables ATK provided needs to be updated or changed to be consistent with the responses ATK has given to comments 4 and
8 and our understanding of how the risk assessment will be conducted. In addition, the Division requests a few other changes be made to the tables as discussed below:

Table 2 – Summary of Receptors and Exposure Pathways

Table 2 indicates that a Future Industrial Worker will be evaluated at the location of maximum on-site impact. However, the table does not address the future hypothetical resident/farmer
that will be addressed at the location of maximum impact, or deposition (assumed to be on-site). In the response to comments 4 and 8, ATK has indicated that exposures to the future
hypothetical resident/farmer “will be evaluated based on the exposure point concentrations calculated by OBODM from the maximum annual deposition area.” Please revise Table 2, or Table
x, to include the future, hypothetical resident/farmer evaluated at the location of maximum deposition.

In addition, Table 2 should indicate that risk from inhalation will be evaluated for resident and farmer receptors and industrial workers that work outside and acute risk (for inhalation)
will be evaluated for all receptors based on a one-hour exposure.

Table x – Summary of On-Site Receptors

The Division asks that ATK include all receptor locations (e.g., Howell Dairy, Adams Ranch) in Table x, or another table if ATK prefers to separate on-site and off-site receptors. The
table should include the two new discrete receptors (Thatcher and Penrose) and the site of maximum deposition, as discussed above. As already shown on the table, please include each
receptor type (e.g., child farmer) that will be evaluated for each receptor location.

Table x – Exposure Assumptions

The averaging time for noncarcinogens and the exposure duration listed for the Farmer Adult do not agree with the values recommended in the 2005 HHRAP. The HHRAP recommends an averaging
time and exposure duration of 40 years for an adult farmer. Please revise the table entries to reflect the HHRAP recommended values or provide sufficient justification for using a value
of 30 years for these two parameters. In addition, please identify the source of the values listed in the table as it should be clear whether the values are recommended by the HHRAP
or are site-specific values requiring justification.

TN201100384 1

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
TN201100384 Printed on 100% recycled paper

Solid and Hazardous Waste Control Board
Kevin Murray, Chair
Kory Coleman, Vice-Chair
Michael D. Brehm, P.E.
Scott Bruce
Carlton Christensen
Jeff Coombs, MPH, LEHS
R. Ryan Dupont, Ph.D.
Larry A. Ellertson
Brad Mertz
Gary Mossor
John D Newman
Dennis Riding
Amanda Smith
Scott T. Anderson
Executive Secretary

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