WI0800040_Correspondence_19980223

0/24/98 TUE 08:58 FAX [phone] DE&S AUSTIN
Zoo'
DATE: Marcr. , 1998
TO:
Mr. Marcus Geist
North Carolina DEHNR
FROM: John Londercan
PHONE: 919-715 B e6
FAX: [phone]
;F-11' 3
PHONE: [phone]
RE: Letter to Dr. Williams of the North Carolina Department of Health and
Human Services on Arsenic in Calcium Chloride Sources and Potential
Impact Lo
CC: NA
Number of pages including cover sheet:
Comments:
Duke Engineering & Services, Inc.
9111 Research Boulevard
Austin, Texas 78758
Telephone: [phone]
Facsimile: [phone]
DE&ES
Duke Engineering &Services

03724/98 TUE 08:58 FAX [phone]
DE&S AUSTIN J002
❑E&S
Dukeffigineming&Stmikes
9111 Research Boulevard
Austin, TX 78758
March 19, 1998
Dr. Luanne Williams
North Carolina Department of Health and Human Services
Occupational and Environmental Epidemiology Section
P.O. Box 29601
Raleigh, North Carolina 27626-0601
512 425-2000
Fax [phone]
RE: Additional Information Requested to Do Risk Assessment For a Proposed
Partitioning Interwell Tracer Test at Site 88, Building HP 25, Camp Lejeune, North
Carolina
Dear Dr. Williams:
We initially forwarded information to support a risk assessment, as referenced above, on
November 19, 1997 and December 12, 1997. One of the injectates discussed was calcium
chloride. We have since discovered that the calcium chloride salt contains a maximum of 3
nig/L arsenic. When a 1,000 mg/L calcium chloride injectate solution is prepared, this will
imply a maximum arsenic concentration in the injectate of 3 ug/L.
The injection/extraction operations will be performed only in the shallow aquifer. This
aquifer consists of approximately ten feet of saturated fine sand and silt found at a depth
of 8 to 18 feet below ground surface. There is a competent clay layer at the base of the
aquifer which separates in from the underlying Castle-Hayne aquifer. The clay layer is
able to support a head difference of 8 feet between the aquifers.
The calcium in the injectate prevents the deflocculation of clay minerals present in the
aquifer. If calcium is not used, fines are mobilized in the aquifer which then lodge in pore
spaces small enough to capture them. This leads to a significant degradation in hydraulic
conductivity making the injection/extraction operations required to remediate the shallow
aquifer impractical. The purpose of this letter is to provide further information on the
food grade calcium chloride we propose to use.
Sources for Calcium
We have investigated numerous grades and sources for calcium. The purest grade of
calcium we have found in the quantities required for this work is food grade. None of the
sources for calcium we found state a maximum possible concentration of arsenic less than

08/24/98 TUE 08:59 FAX [phone]
DE&S AUSTIN Q]003
DE iS
Dareagmeeri &Serr ices
3 mg/L. This criteria is apparently based on the Food Chemical Codex limit stipulated for
food grade calcium chloride. Additional sources for calcium chloride investigated are
calcium sulfate and calcium carbonate. A copy of the page from the Food Chemicals
Codex for food grade calcium chloride showing the 3 mg/L maximum permissible
concentration of arsenic is attached.
Water Supply Wells
There are no active water supply wells located within a one mile radius of the work site.
The nearest active water supply well is HP-642 which is located approximately 1.5 miles
east of the site.
There are no private wells within the confines of Camp Lejeune and none are allowed. All
water on base is supplied by the Camp Lejeune water distribution system (analogous to a
municipal water supply system).
The closest off -base property and hence the nearest possible private well, is
approximately 4 miles from Site 88 to the northeast.
Surface Water
The New River, located approximately 3,000 feet west of the site, is the nearest surface
water.
Estimated Maximum Downgradient Dissolved Arsenic Concentrations
The ground water flow direction in the vicinity of Building HP25 is to the southwest. To
estimate the maximum concentrations of arsenic which may be found downgradient of the
demonstration area, it was assumed that the demonstration would last for three months
and that during that entire period of operation, 0.5 gallons of injectate with a dissolved
arsenic concentration of 3 ug/L would be lost to the aquifer every minute of continuos
injection/extraction operations. The analytical solution of De Josselin De Jongl was used.
The analysis determined that once natural ground water movement has displaced the
plume a distance of 100 meters down gradient (southwest), the maximum arsenic
concentration will be approximately 0.06 ug/L. Given the natural ground water gradient
at the site and the relatively low hydraulic conductivity of the sediments, it is estimated
that it will take approximately 10 years to reach the peak concentration at that distance.
By the time the plume has been displaced 900 meters, or the approximate distance to the
New River, it is estimated that the maximum arsenic concentration will be 0.006 ug/L. A
worksheet showing the assumptions of the analyses and resultant data curves is attached.
Once again, any arsenic introduced into the aquifer will be carried by natural ground water
flow toward the southwest. The nearest public supply well is located some 1.5 miles east
I De Josselin De Jong, G. 1958. Longitudinal and transverse diffusion in granular deposits. Transactions,
American Geophysical Union 39, no. 1:67.

0i/24/98 TUE 09:00 FAX [phone] DE&S AUSTIN
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DE
Ddieigineethig&Sentes
(generally upgradient) of the site. The nearest possible private water supply well is no
closer than 4 miles to the northeast.
Collection of Ground Water Samples for Arsenic Analysis
Ground water samples were collected from two wells installed in the shallow aquifer at the
demonstration area on November 17, 1997. The detection limit for the analyses was 100
ug/L. Both samples were non -detect for arsenic.
To monitor the possible impact of the injection of arsenic associated with the calcium
chloride we propose to inject, we suggest the collection of ground water samples from
four wells in the demonstration area before injection operations are begun. We then
propose to collect samples from the same wells after 4 weeks of injection and then at the
end of the PITT (9 weeks). The samples would be analyzed for the presence of dissolved
arsenic using SW 846 method 206.2. This is a graphite furnace method for water samples.
The detection limit is 5 us/L.
We propose collecting ground water samples from the wells in the demonstration area
instead of from wells downgradient for two reasons. The first is that with the relatively
low hydraulic conductivity of the shallow aquifer (as discussed above), arrival of any
dissolved arsenic at downgradient wells will not be immediate. The travel time for a peak
concentration from the demonstration area to a point just forty feet away would be
approximately one year. The second is that the wells in the demonstration area where the
injection takes place should exhibit the highest concentrations and therefore provide the
best estimate of any potential impact.
Conservative Interwell Tracer Test (CITT1
A CITT is planned prior to the full partitioning interwell tracer test. The CITT we
propose will consist of injecting a solution of either isopropyl alcohol or methanol mixed
at 1,000 mg/L and sodium fluorescein mixed at 200 mg/L. The concentrations of these
compounds would be reduced by continued extraction operations after their introduction
to average concentrations of 1 to 5 mg/L in the demonstration area. The analysis of
maximum concentrations which would be found downgradient, as presented in our letter
to you of December 12, 1997, would be valid for these compounds as well.
The results of the CITT will be incorporated into the final design of the PITT. We had
originally hoped to use a solution of 10,000 mg/L calcium chloride to perform the CITT
but have abandoned that idea in favor of using the compounds discussed above due to
discovery that the calcium chloride salt contains a maximum of 3 mg/L arsenic.

63/24/98 TUE 09:01 FAX [phone] DE&S AUSTIN
lJ005
DE€'S
Duke ilom th sprwas
I would like to thank you for your attention to this matter. If there are any questions or if
more information is required, please call me.
Sincerely,
John T. Londe an
Senior Hydro eologist
cc:
Ms. Laura Yeh, Naval. Facilities Engineering Service Center
Ms. Dianne Reid, North Carolina DEEINR
Mr. David J. Lown, North Carolina DEHNR
Mr. Marcus Geist, North Carolina DEHNR
Ms. Kate Landman, Naval Facilities Engineering Command
Mr, Mick Senus, AC/S EMD Camp Lejeune
Mr. Matthew Batman, Baker Environmental
Mr. Fred Holzmer, Duke Engineering and Services

03/24/98 TUE 09:01 FAX [phone] DE&S AUSTIN
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03/24/98 TUE 09:04 FAX [phone]
DE&S AUSTIN 0 007
VVAIS Document Retrieval Page 1 of 2
[Code of Federal Regulations]
[Title 21, Volume 3, Parts 170 to 199]
[Revised as of April 1, 1997]
From the U.S. Government Printing Office via GPO Access
[CITE: 21CFR184.1193]
[Page 460-4611
TITLE 21--FOOD AND DRUGS
CHAPTER I --FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES
PART 184--DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE --Table o
Subpart B--Listing of Specific Substances Affirmed as GRAS
Sec. 184.1193 Calcium chloride.
(a) Calcium chloride (CaCl<INF>2</INF><t-bullet>2H<INF>2</INF>O, CAS
Reg. No. 10035-04-8) or anhydrous calcium chloride (CaCl<INF>2,</INF>
CAS Reg. No. 10043-52-4) may be commercially obtained as a byproduct in
the ammonia -soda (Solvay) process and as a joint product from natural
salt brines, or it may be prepared by substitution reactions with other
calcium and chloride salts.
(b) The ingredient meets the specifications of the Food Chemicals
Codex, 3d Ed. (1982), p. 47, which is incorporated by reference. Copies
are available from the National Academy Press, 2101 Constitution Ave.
NW., Washington, DC 20418, or available for inspection at the Office of
the Federal Register, 800 North Capitol Street, NW., suite 700,
Washington, DC 20408.
(c) The ingredient is used as an anticaking agent as defined in
sec. 170.3(0)(1) of this chapter; antimicrobial agent as defined in
Sec. 170.3(0)(2) of this chapter; curing or pickling agent as defined in
Sec. 170.3(o)(5) of this chapter; firming agent as defined in
Sec. 170.3(o)(10) of this chapter; flavor enhancer as defined in
Sec. 170.3(0)(11) of this chapter; humectant as defined in
Sec. 170.3(0)(16) of this chapter; nutrient supplement as defined in
Sec. 170.3(0)(20) of this chapter; pH control agent as defined in
sec. 170.3(0)(23) of this chapter; processing aid as defined in
Sec. 170.3(o)(24) of this chapter; stabilizer and thickener as defined
in Sec. 170.3(0)(28) of this chapter; surface-active agent as defined in
Sec. 170.3(0)(29) of this chapter; synergist as defined in
Sec. 170.3(o)(31) of this chapter; and texturizer as defined in
Sec. 170.3(o)(32) of this chapter.
(d) The ingredient is used in foods at levels not to exceed current
good manufacturing practices in accordance with Sec. 184.1(b)(1).
Current good manufacturing practices result in a maximum level, as
served, of 0.3 percent for baked goods as defined in Sec. 170.3(n)(1) of
this chapter and for dairy product analogs as defined in
Sec. 170.3(n)(10) of this chapter; 0.22 percent for nonalcoholic
beverages and beverage bases
[[Page 461]]
as defined in Sec. 170.3(n)(3) of this chapter; 0.2 percent for cheese
as defined in Sec. 170.3(n)(5) of this chapter and for processed fruit
and fruit juices as defined in Sec. 170.3(n)(35) of this chapter; 0.32
percent for coffee and tea as defined in Sec. 170.3(n)(7) of this
chapter; 0.4 percent for condiments and relishes as defined in
Sec. 170.3(n)(8) of this chapter; 0.2 percent for gravies and sauces as
defined in Sec. 170.3(n)(24) of this chapter; 0.1 percent for commercial
jams and jellies as defined in Sec. 170.3(n)(28) of this chapter; 0.25
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03/24/98 TUE 09:05 FAX [phone] DE&S AUSTIN
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WAIS Document Retrieval Page 2 of 2
percent for meat products as defined in Sec. 170.3(n)(29) of this
chapter; 2.0 percent for plant protein products as defined in
Sec. 170.3(n)(33) of this chapter; 0.4 percent for processed vegetables
and vegetable juices as defined in Sec. 170.3(n)(36) of this chapter;
and 0.05 percent for all other food categories.
(e) Prior sanctions for this ingredient different from the uses
established in this section do not exist or have been waived.
[47 FR 27808, June 25, 1982, as amended at 61 FR 14247, Apr. 1, 1996]
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Zj 009
Assumptions:
Rates of over injection 0.5 gpm 96.25 ft^3/day
injection duration 3 month 90 clays
Porosity 0.3
Uniformed thickness 8 ft
Conductivity 0.0005 cm/s
Hydraulic gradient 0.014
DL= 1 m21d
D3= 0.1 meld
Co 3 ppb
Assuming no retardation and degradation
Calculations:
Total Volume injected 64795.5 gals 8662.5 ft'
Source Size 3609.375 ft2 335.3 m2
Source Radia 10.33135 m
Darcy velocity =K*I 7.00E-06 cm/s 0.006048 mid
seepage velocity =K"I/porosity 2.3333E-05 cm/s 0.02016 mid
The following figure shows the results based on the analytical equation from
De Josselin De Jong (1958), The equation can also be found in the text book by Fetter(1993).
Time (years) or Distance (in)
1000.0
10.0
1.0
10.000
1.000
0
0.100
8
1
0.010
0.1 I i 1 0.001
0 100 200 300 400 500 600 700 800 900
Distance from the source(m)
Time required to reach this distance (years) - - Plume x dimension (m)
-NNW --Plume ydimension (m)
- Peak Concentration (ppb)
References:
(1) De Josselin De Jong, G. 1958. "Longitudinal and Transverse Diffusion In Granular Deposits"
Trans, American Geophysical Union 39, no. 1:67
(2) FetterC.W. 1093. Contaminant Hydrogeoiogy, Macmillan Publishing Company.