DSHW-2006-007961 - 0901a068801620ef

December 1, 2006

Paul Hancock
Remediation Manager
ATK Launch Systems, Inc.
P.O. Box 707
Brigham City, Utah 84302-0707

Subject: ATK Launch Systems – Promontory Facility
Sampling Report for Hazardous Waste Management Unit (HWMU) I-10
(Final Closure Certification Report)

Dear Mr. Hancock:

This letter includes comments regarding the closure certification for the HWMU I-10 burn grounds. HWMU I-10 is about 900 ft2 in area and was used for open burning of small amounts of
waste. The ash and waste were removed from the area. A total of 15 samples, including three samples from within the main burn pit, were collected. Volatile organics, explosives and
mercury were identified as site contaminants, but the concentrations of these contaminants appear to be well below the EPA risk-based screening values as described in comments below:

The certification report was submitted before the Division adopted the risk-based closure standards rule (R315-101), and the report does not include human health or ecological risk assessments
or a soil to groundwater evaluation. However, the Division compared the analytical sample data in the report with EPA Region IX Preliminary Remediation Goals (PRGs) and soil to groundwater
screen values. This simple comparison indicates that, for the reported compounds, this site qualifies for residential use, and site soils are not a source of groundwater contamination
as defined in R315-101-3, but ATK should supply this information in table or other brief format for the chemicals of concern.

Please provide a brief evaluation in Table or other format of the potential for ecological risk as required in R315-101. Based on our evaluation of the data, it does not appear that
an ecological risk is present because: 1) the affected area is limited to 900 ft2 which limits the number of receptors that could be potentially effected, 2) the area does not have
unique or critical habitat, 3) the chemicals are not bioaccumulative, and 4) the concentrations of chemicals are relatively low (e.g., they should be compared to USEPA Region 5 EDQLs).

Please provide justification for not analyzing the samples in the area of the burn pit for products of incomplete combustion such as dioxin and polycyclic aromatic hydrocarbons (PAHs).
Many of these compounds have low toxicity values. It is noted that the site is small, waste and ash was removed, and dioxin and PAH have limited mobility in the environment. The Division
may collect a sample in the burn pit area for PAHs.

The Division also notes that soil samples were analyzed for perchlorate, and that this compound was not detected above the detection limit of 3 mg/kg. The PRG for perchlorate in soil
is 7.8 mg/kg (www.epa.gov/region09/waste/sfund/prg/files/04prgtable.pdf).

The Division notes that the report indicates VOCs and explosives were within “background” concentrations. For future reference, the Division considers all anthropogenic chemicals detected
at a site to be site related, and these contaminants must be included in risk assessments and soil screening evaluations. Clean (non-risk based) closure is only applicable in absence
of all site related contamination. A response to this comment is not necessary.

Submittal of responses to these comments rather than a revised closure certification document is recommended. The comment responses can be considered part of the final closure certification
report. Please provide the responses within 60 days of receipt of this letter.

If you have any questions, please contact David Larsen at [phone].

Sincerely

Original Document signed by Dennis R. Downs on 12/1/06

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

DRD/dcl/kk

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

December 1, 2006
Page 2

TN200601280.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