DSHW-2009-019293 - 0901a068801596ef

state ofUtah '^""le'^HX
DEPARTMENT OF ENVIRONMENTAL QUALITY
DIVISION OF SOLID AND HAZARDOUS WASTE
Michael O. Leavitt 9
Governor u
Dianne R. Nielson, Ph.D. "
Executive Director
Dennis R. Downs
Director
October 10, 1995
288 North 1460 West
P.O. Box 144880
Salt Lake City. Utah 84114-4880
[phone] Voice
[phone] Fax
[phone] T.D.D.
1
Mr. Joe D. Thompson, Director
Waste Management and Environmental Services
Thiokol Corporation
P.O. Box 689
Brigham City, UT 84302-0689
Re: Site Management Plan
M-186 Ponds
Dear Mr. Thompson:
In September 1994, the Division of Solid and Hazardous Waste (DSHW) received a request from
Thiokol to close in-place, two industrial wastewater ponds located at M-186. This request was to
close the ponds under the risked based closure rules found in R315-101 of the Utah Administrative
Code. After a preliminary review and comments by the DSHW, this report was resubmitted to the
Division on August 10, 1995.
The ponds, when sampled, had been found to contain trace amounts of 1,1,1 Trichloroethane (TCA)
and 1,1 Dichloroethane (DCA). A risk assessment was performed by Thiokol under R315-101. This
assessment found that the risk for exposure or harm to human health and the environment to be
extremely low. The Health Index, as specified in R315-101-1(3), was five to seven orders of
magnitude less than one. The toxicological information currently available for TCA and DCA is
limited in regards to carcinogenicity. Based on the information provided by Thiokol; the low
concentrations ofthese contaminants, coupled with the remote location of M-186, led the Executive
Secretary to agree with the risk assessment findings and grant approval of the Risk Assessment
Report.
R315-101-6 and 7 require Thiokol to prepare a Site Management Plan outlining how closure of the
M-186 ponds will be completed. This plan was included in the draft Risk Assessment Report. After
calculating the risks involved, Thiokol has chosen a "No Further Action" option. Thiokol plans to
remove and manage any storm water from the ponds and then backfill the ponds to grade with clean
native soils. The Executive Secretary reviewed this plan and granted draft approval on September
1, 1995.
As a result of draft approval of this plan, a public notice was given, and a 30-day public comment
period and a public hearing were held. The public comment period began on September 6, 1995 and
ended on October 5, 1995. The public hearing on Thiokol's proposed Site Management Plan was
held on October 2, 1995 at the Brigham City Library. There were no conmients submitted to the
Division regarding the Site Management Plan.
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The Executive Secretary hereby grants fmal approval for the Site Management Plan to close in-
place, the two industrial waste ponds located at M-186. Thiokol shall notify the Divison as to the
schedule for closure.
If you have any questions about this letter, please contact Otis Willoughby at 538-6170.
Sincerely,
Dennis R. Downs
Executive Secretary
Utah Solid and Hazardous Waste Control Board
DRD\OHW\ow
John C. Bailey, M.D., M.S.P.H., Health Officer/Department Director,
Bear River District Health Department
ADULT DCA CANCER
C: =
IR:
CF
Fl:
EF
ED
BW
AT
I: =
I = !
= 0.033724
= 100
:=lG-6
= 0.5
= 350
: = 24
:=70
: = 70-350
CIRCFnEFED
BWAT
?.259'10'^
WHERE:
C = Concentration of the chemical
IR = Ingestion Rate
CF = Conversion Factor
Fl = Fraction ingested frorn contaminated source
EF = Pathway specific exposure frequency
ED = Exposure Duration
BW = Body Weight
AT = Averaging time
I = Intake