DSHW-2003-006496 - 0901a068801600d0

May 28, 2003

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

RE: ATK Thiokol Propulsion's April 25, 2003 Report on the Uptake of Perchlorate by Plants Adjacent to Contaminated Springs at the Promontory Facility - EPA ID #UTD009081357

Dear Mr. Hancock:

The Division of Solid and Hazardous Waste (the Division) has reviewed the ATK Thiokol Propulsion (Thiokol) report on the potential risk to human health from the ingestion of beef from
cattle that have consumed vegetation and water contaminated with perchlorate.

Based on the information provided by Thiokol, potential exposure to humans via beef contaminated with perchlorate is likely below both the USEPA’s interim and proposed perchlorate reference
doses (0.0005 and 0.00003 mg/kg-day). However, there are some points, described in the following comments, that need to be addressed in order to make the information provided by Thiokol
complete. The Division requests that Thiokol address these comments and resubmit the document.

In addition, due to the high degree of uncertainty in this analysis, the investigation and conclusions should be reevaluated as new information becomes available.

1. The conclusion that a cattle to human exposure route is a very low probability of concern is dependent on an extremely limited dataset for perchlorate concentrations in plants.
The sample results provided by the U.S Fish and Wildlife Service may not adequately define the extent of perchlorate in vegetation. Future characterization efforts at Thiokol should
include additional samples of vegetation.

2. The vegetation and water samples were not collected or analyzed by the State of Utah as indicated by the text. U.S. Fish and Wildlife Service provided the results. Please correct
the text.

3. Attachment 3. Beef Ingestion Rate. A beef ingestion rate of 0.813 g/kg-day fresh-weight (FW) was derived from data for the U.S. population and may underestimate beef consumption
for local ranchers. A more appropriate data set is likely the beef ingestion rate for home produced beef presented in Table 13-36 of the USEPA (1997) Exposure Factors Handbook. The
90th percentile consumption rate for homegrown beef is 2.54 g/kg-day FW and the mean is 1.07 g/kg-day FW based on weighted averages for ages 6 through 69 and adjusted for cooking and
preparation losses. Please reevaluate the beef ingestion rate to ensure that the values used are conservative.

4. Attachment 3. Cattle Water Consumption. The proposed water ingestion rate for cattle is 15 gallons/day and may underestimate water consumption for the summer months. The Virginia
Cooperative Extension (http://www.ext.vt.edu/news/periodicals/livestock/aps-99_09/aps-0110.html) estimates water consumption for an 1100 lb. cow at 90 F to be 17.6 gallons and a rule
of thumb for water consumption is 1.5 gallons for every 100 lbs. The Michigan State University Extension Service estimates two gallons for every 100 lbs (http://www.msue.msu.edu/msue/imp/modaa/23310001.html)
for hot weather resulting in a daily consumption rate of 24 gallons for a 1200 lb. cow. A lactating cow may require nearly twice as much water as a non-lactating cow. The Utah State
Extension Service notes that water intake increases with increasing TDS (http://extension.usu.edu/publica/agpubs/ah/beef28.pdf). Please reevaluate the water consumption rate for cattle.

5. Attachment 3. Cattle Grass Consumption. The proposed grass consumption rate of 13.6 kg/day is equal to about 30 lbs, not 19.4 lbs as listed (calculations are correct because they
are based on 13.6 kg).

6. Attachment 3. Please remove the “confidential” footnotes.

7. Attachment 3, p. 2. Total perchlorate intake for the cow is calculated by adding the intake from water and feed, not multiplying (results are correct; equation is incorrect).

8. Attachment 3, p. 2. Please document how the perchlorate steady-state plasma concentration was calculated.

9. Attachment 4. Please document how the perchlorate concentration in the muscle was calculated.

10. What are local ranching practices for beef raised for personal consumption? Do local ranchers slaughter cattle without supplementing their feed with grain?

Please address the above comments within 30 days of the date of this letter. If you should have any questions, please contact Jeff Vandel at 538-9413. Thank you for your cooperation.

Sincerely,

Original Document Signed by Dennis R. Downs on 5/29/03

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

DRD\jv\kk

c: John C. Bailey, M.D., M.S.P.H., Health Officer/Director, Bear River Health Dept.
Susan Jew, Director, Environmental Services, ATK Thiokol Propulsion

U:\SHW\HWB\JVANDEL\WP\Thiokol\TN200301387
file to: Thiokol

May 28, 2003
Page 2

Michael O. Leavitt
Governor
Dianne R. Nielson, Ph.D.
Executive Director
Dennis R. Downs
Director

Department of Environmental Quality
Division of Solid and Hazardous Waste
288 North 1460 West
P.O. Box 144880
Salt Lake City, Utah 84114-4880
[phone]
[phone] Fax
[phone] T.D.D.
www.deq.utah.gov