DSHW-2006-001781 - 0901a0688013a66d

ATK
ALLIANT TECHSYSTEMS
ATK Thiokol Inc. Tel [phone]
P.O. Box 707 Fax [phone]
Brigham City, UT 84302-0707
12 April 2006
8200-FY07-006
Mr. Dennis R. Downs, Executive Secretary
State of Utah Q p
Department of Environmental Quality fy^ ^T^j-i/L
Division ofSolid and Hazardous Waste .^ . i CXr,
288 N. 1460 w APR H 2006
P.O. Box 144880 U IAH UIVISION OF
Salt Lake City, Utah 84114-4880 SOLID & HAZARDOUS WASTE
Dear Mr. Downs
ATTENTION: Jeff Vandel
Subject: Groundwater Contamination at Process Supply Well TCC3A, ATK Promontory
Facility, EPA ID #009081357
Our office has been in contact with your staff regarding the contamination that has been
monitored at the TCC3A process supply well. As you are aware, this well is the only water
source for the small, remote research and development area called Plant 3. A recent letter from
your office, dated March 27, 2006, requested information on how we will address this issue and
the potential for human exposure.
CuiTently, we are evaluating treatment options to remove the contamination. Details of the
system are still in development and will be provided to your office along with a schedule as they
are finalized. We anticipate that within the next 45 days more details will be resolved.
As staled previously, bottled drinking water has been supplied to this site for many years. This
was done initially because the natural TDS levels make it the water unpalatable. More recently,
since 1998, with the increase of contaminates in the water, source areas have been labeled to
designate them as non-drinking water sources. The other potential sources ofexposure are hand-
washing sinks, a shower and emergency eyewashes. Human exposure to these contaminates in
these situations has been evaluated with a conservative risk assessment. The results show that
these levels do not present an unacceptable risk to human health. The risk assessment is
attached. In the mean time we continue to caution employees at the location to minimize
personal use of the water.
The two septic drain fields at the site have been added to our SWMU list and will be
investigated. For your information, we have been investigating the fate of the perchlorate and
TCE in the two septic systems and initial results show that the perchlorate does degrade and we
also see degradation of the TCE. These results will be shared with your office as they are
finalized.
If you have any questions regarding this information, please direct them to myself at (435) 863-
3344.
Sincerely
r
Paul V Hancock, Manager
Environmental Remediation
April 12,2006
Paul Hancock
Manager, Environmental Remediation
ATK Thiokol Inc.
Promontory Facility
P.O. Box 707
Brigham City, UT 84302-0707
Subject: Human-Health Risk-Based Concentration Goals for Well TCC3A
Dear Paul:
Pursuant to your request, I have evaluated the human-health risks of perchlorate and
trichloroethylene ("TCE") as contained in water obtained from Well TCC3A at your Promontory
facility. Data collected from this well since March 1989 have indicated the following
concentrations of these constituents:
EarthFax
EarthFax
Engineering, Inc.
Engineers/Scientists
7324 So. Union Park Ave.
Suite 100
Midvale, Utah 84047
Telephone [phone]
Fox 801-56 M 861
wvrw.ecalhlax. com
Date
March 1989
September 1992
October 1992
December 1993
February 1996
May 1996
May 2001
October 2002
November 2005
Note: NS = not sampled
Perchlorate
(ug/L)
NS
NS
NS
NS
NS
NS
36
38
42.7
Trichloroethylene
(ug/L)
ND
0.85
ND
1.2
1.9
2.8
7.2
8.7
10.7
ND = not detected at method detection limit
ll is my understanding that this water is used in the Plant 3 area for process purposes as well as
showering and hand washing. It is further my understanding that access points to the water are
labeled to indicate that it is not to be ingested.
In a letter dated March 27, 2006, the Utah Division ofSolid and Hazardous Waste expressed
concern regarding the potential impacts to human health due to showering and hand washing.
Risk-based concentrations of perchlorate and TCE that are considered protective of human health
under the showering and hand washing scenario were calculated using the following equation:
C = -TRx BWxAT
TVxCFxSAxKxETxEFxED
where C = remediation goal at the specified risk level (mg/L)
Paul Hancock
April 12,2006
Page 2
TR = target risk level (dimensionless; TR = 10"^ excess individual lifetime cancer risk
or a hazard index of 1.0 for noncancer risks)
BW = adult body weight (kg)
AT = averaging time (days) = 70 yr x 365 days/yr for carcinogens
= ED X 365 days/yr for noncarcinogens
TV = absorbed toxicity value = SF (for carcinogens)
= 1/RfD for noncarcinogens
CF = units conversion factor (10 L/cm-m^)
SA = adult skin surface area (m^)
Kp = chemical permeability constant (cm/hr)
ET = exposure time (hr/day)
EF = exposure frequency (day/yr)
ED = exposure duration (yr)
SF = oral cancer slope factor (mg/kg-day)"'
RfD = oral reference dose (mg/kg-day)
The showering scenario was considered more conservative than hand washing since it involves
contact with more skin area for a longer period of time. Thus, the following exposure factors
were assumed for these calculations (see U.S. Environmental Protection Agency, 2004):
Adult skin surface area (SA) = 1.8 m
Reasonable maximum exposure time (ET) = 0.58 hr/day
Exposure frequency (EF) = 250 days/yr
Exposure duration (ED) = 25 yr
Based on these factors and appropriate reference doses and cancer slope factors, risk-based
concentrations under a showering and hand-washing scenario were calculated as follows (see
Attachment A):
Perchlorate = 6,900 ug/L
TCE= 210 ug/L
Hence, current concentrations of these constituents in well TCC3A are considered protective of
human health.
1 have appreciated the opportunity to provide this information. Please contact me if you have
any questions.
Sincerely,
Richard B. White, P.E.
President
Paul Hancock
April 12,2006
Page 3
References Cited
U.S. Environmental Protection Agency. 2004. Risk Assessment Guidance for Superfund -
Volume 1: Human Health Evaluation Manual (Part E, Supplemental Guidance for Dermal
Risk Assessment), Final. EPA/540/R/99/005. Office of Superfund Remediation and
Technology Innovation. Washington, D.C.
ATTACHMENT A
Risk-Based Concentration Calculation
PRGs FOR DERMAL PATHWAY
Source: WATER
Scenario: pHanp^hlngJnd^ls^^
Site: ?Promprftpy^Vyelfl3^^
Goveming equations:
Cancer PRG:
Noncancer PRG:
where C =
TR =
HQ =
BW =
AT =
SFo =
RfDo =
CF =
SA =
Kp =
ET =
EF =
ED =
Assumptions:
Target risk (TR) =
Target haz. quo. (HQ) =
Body v^eight (BW) =
Average lifetime =
Skin surface area (SA) =
Exposure time (ET) =
Exposure freq. (EF) =
Exposure dur. (ED) =
PRG calculation:
C = (TR X BW X AT) / (SFo x CF x SA x Kp x ET x EF x ED)
C = (HQ X BW X AT X RfDo) / (CF x SA x Kp x ET x EF x ED)
Concentration resultsing in the specified risk (mg/l)
Target cancer risk (unitless)
Target hazard quotient (unitless)
Body weight (kg)
Averaging time (days) = 70 yr x 365 for cancer risk, ED X 365 for noncancer risk
Oral cancer slope factor (mg/kg-day)-1
Oral chronic reference dose (mg/kg-day)
Units conversion factor (10 L/cm-m2)
Adult skin surface area (m2)
Chemical permeability constant (cm/hr)
Exposure time (hr/day)
Exposure frequency (days/yr)
Exposure duration (yr)
ai:00ET006
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Ref
kg
yr
m2
hr/day
days/yr
yr
•••-•1; 'P
^m 'M
^m i:2iS.
Contaminant
: Perch \6f3AeM^::i'S:'':'!^3^'f-
;Trlchl6retHyleneS:;Wf?^*^
ummmmmmmk \0m':S:^fWm^M^&^
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W.\i:fW^k#M:MM^^ii
^•^m Ammimm^^ri^ :^w?^}K^^^W0m^
^^M>:Mi^^:&iiMim
':^-':--^\-'y^: '-.rr:. '\-.''fr(-\'y:-T:^^^^
RfDo
(mg/kg-d)
^:7;OOE;004:
s6:00E^O03i
mm^m^
mmwM-•tfe^-^ii^/Slift
y;-.*-'?'^s.i^j
mM^im^
mmm^i
^\-^^ix;-. F^^ri-^]^'-'
Ref
sm S4^'
mm.
mB avSi
wm m'i;^
•km
'i-'"'ii-'!'
SFo
(mg/kg-d)-1
llliisiffi^fjj?
i1S10Ei002;
mmmim mm='m'i:i
mm'S'.m mmmm umrmm mm=M^i
•^Sli^Mii;
^:m^^mm
Ref
''MK
mtm
^mi
;,;••';•.•!. :..''j
Wi'^-J
g^W
ilf:i
^Mk
'•m
Kp
(cm/hr)
i,saB0:0O1^
MfS0:O12i
mm^m m&m!^i WM^f^'^I'
^WMify:
mK'smm W^mMM
^mmmm 'Mmms.
Ref
^m mm mm W^"}
*8§
Mi;
WL
Mm
vii;K
m^r
Noncancer PRG
(mg/l)
6.9E+000
4.9E+000
Cancer PRG
(mg/l)
No SFo
2.1E-001
References:
1. RAGS Part A, EPA 1989 (EPA/540/1-89/002)
2. RAGS Part E. EPA 2004 (EPA/540/R/99/005)
3. National Research Council, "Health Implications of Perchlorate Ingestion", 2005
4. Withdrawn value requested by UDSHW in a letter to ATK dated 1 Nov 2005