WI0700012_Application_20021007

4
Response to NCDENR Comments
Renewal Application for Injection Well Permit
W10700012
Tank Farm Remedial Action System
PCS Phosphate Company
Aurora Phosphate Operations
Aurora, North Carolina
A&A ENGINEERING, INC.
8008 S. Orange Avenue
Orlando, Florida 32809
Phone [phone]
FAX [phone]

A&A ENGINEERING, INC.
October 1, 2002
File Number 02-051
PCS Phosphate Company, Inc.
P.O. Box 48
Aurora, North Carolina 27806
Attention: Mr. D. Daniel Winstead III
Subject: Response to NCDENR Comments, Renewal Application for Injection Well Permit
WI0700012, Tank Farm Remedial Action System, Aurora Phosphate Operations,
Aurora, North Carolina
Gentlemen:
As requested, we have reviewed the attached letter from the North Carolina Department of
Environment and Natural Resources (NCDENR), Division of Water Quality, Groundwater Section
dated February 19, 2002 from Mr. Evan O. Kane, Program Manager, Underground Injection
Control, to your Mr. Winstead conceming the Croatan Formation injection and withdrawal well
system portion of the tank farm remedial action system at the Aurora Phosphate Operations. The
Groundwater Section states that it has the following concerns about the performance of the
injection and withdrawal well system:
• the injection well system may be causing contaminants to migrate into previously
uncontaminated portions of the Croatan Formation or other aquifers; and
• the injection and withdrawal well system may not be achieving the predicted
remediation goals.
This letter presents an overview of the history of development of the remedial action plan and
remedial action design implemented in the tank farm with the approval of the Groundwater Section
of the then Division of Environmental Management, and reviews the performance of the remedial
action system to -date as documented by ten years of performance monitoring.
History of Tank Farm Remedial Actions
In accordance with the requirements of a notice of noncompliance issued on August 8,1988 by the
then Division of Environmental Management (DEM), in response to a May 1988 leak incident at
Tank 008, PCS Phosphate Company, Inc. (then Texasgulf, Inc.) retained Ardaman & Associates,
Inc. to: (i) characterize groundwater conditions in the tank farm and extent of impacts from the leak
incident; and (ii) prepare a remedial action plan with corrective actions to remediate the
groundwater impacts. Tank 008 (see Figure 1-1 in Attachment I) was an above -ground, rubber -
lined, phosphoric acid storage tank containing 54 percent phosphoric acid (-53% P205 or —12%
as P, with, among other constituents, 2.6% SO4, 0.5%F and <0.01 % CI).
8008 S. Orange Avenue, Odando, Florida 32809 • Phone [phone] • FAX [phone]

c
PCS Phosphate Company, uric.
File Number 02-051
-2-
Preliminary Contamination Assessment and Remedial Action Plan
The preliminary contamination assessment and remedial action plan for the tank farm were issued
on September 7, 1988 and October 10, 1988, respectively. The objectives of the remedial action
plan submitted to the DEM were to: (i) remove the source of the leak (Tank 008) addressed in the
notice of noncompliance; (ii) minimize and contain future spills from tanks and associated pumps
and pipelines in the tank farm (source control); (iii) pump contaminated groundwater from the
surficial soils underlying the tank farm; and (iv) protect the adjacent Pamlico River barge slip from
significant impacts from contaminants in the surficial soils. The following remedial actions were
undertaken to achieve these objectives.
• Tank 008 was repaired to remove the source of the leak addressed in the notice of
noncompliance.
• New containment facilities were installed below the existing tank farm main east -to -
west pipe rack and phosphoric acid and super phosphoric acid tanks to minimize
and contain future spills.
• An estimated 1.7 million gallons of contaminated groundwater (pH=2.0 to 4.5 and
conductivity = 2,700 to 20,500 pmhos/cm) in the surficial soils underlying the pipe
rack and tanks were removed by temporary construction well -point systems from
July through November 1988 in conjunction with installation of the new containment
facilities. This volume was equivalent to the amount of groundwater initially
contained within the surficial sands within the center 150-foot (north -south) by 500-
foot (east -west) section of the tank farm along the pipe rack and phosphoric acid
storage tanks likely dewatered by the well -point systems.
• The quality of groundwater within the surficial aquifer flowing northward from the
tank farm towards the Pamlico River barge slip was monitored at two well clusters
(designated MWTF-2 and MWTF-3) to determine if additional remedial measures
were needed to protect the Pamlico River from significant impacts. The Pamlico
River contains brackish water with high conductivity (-30,000 pmhos/cm), total
dissolved solids (-20,000 mg/I), chloride (>10,000 mg/I) and sulfate (-1,500 mg/I
concentrations), and low phosphorus (-0.2 mg/I) and fluoride (<1 mg/I)
concentrations.
Supplemental Remedial Action Plan
In accordance with the requirements of a notice of violation issued by the DEM on September 1,
1989, in response to a June 1989 underground drain line leak incident in the tank farm, a
supplemental remedial action plan was subsequently issued on October 31, 1989. The
supplemental remedial action plan presented: (i) an overview of reported leak incidents at the tank
farm and status of the actions undertaken in accordance with the October 1988 remedial action
plan; (ii) a description of the hydrogeology of the tank farm; (iii) a characterization of groundwater
quality in the tank farm based upon three quarterly sampling events in 1989; and (iv) a
supplemental remedial action plan to contain and actively clean-up (as requested by the DEM in
the September 1989 notice of violation) groundwater underlying the tank farm.

PCS Phosphate Company; inc.
File Number 02-051 -3-
Based upon field testing and groundwater monitoring conducted for the supplemental remedial
action plan, the following prevailing hydrogeologic conditions were identified in the tank farm at the
time of the leak incidents. The generalized subsurface stratigraphy previously developed for the
tank farm is depicted on Figure 2-3 in Attachment I.
Surficial Sand Laver: The direction of groundwater flow was north -northwestward (Figure 2-4 in
Attachment I) with a gradient of about 0.005 feet/foot and relatively slow horizontal seepage
velocity of about 2 feet/year. Concentrations of phosphorus, fluoride and sulfate (major
constituents in phosphoric acid) in upgradient monitor well (MWTF-1A) were relatively low
indicating that groundwater impacts did not exist in the surficial sand south of the tank farm (Figure
3-1 in Attachment I). At downgradient well -point sampling location WPTF-1A, immediately adjacent
to the pipe rack and storage tanks, the phosphorus, sulfate and dissolved solids concentrations
were elevated. At further downgradient monitor wells MWTF-2A and MWTF-3A, some 250 to 350
feet north of the pipe rack and storage tanks, total phosphorus concentrations were low (only 0.15
and 0.22 mg/I) and sulfate was only slightly elevated (308 mg/I) at MWTF-2A. Accordingly, in 1989,
impacts from phosphoric acid leaks/spills did not occur at monitor wells MWTF-2A and MWTF-3A,
which was expected given the relatively slow 2 feet/year horizontal seepage velocity in this layer.
Confined Sand Laver: The direction of groundwater flow in the confined sand layer (Figure 2-5 in
Attachment I) was generally northward to north -northeastward, with a gradient of about 0.01
feet/foot and a horizontal seepage velocity of about 300 feet/year. At upgradient monitor well
MWTF-1 B, the phosphorus, fluoride and sulfate groundwater concentrations were relatively low,
indicating that impacts did not exist in the confined sand layer south of the tank farm (Figure 3-2
in Attachment I). At downgradient well -point sampling location WPTF-1C, immediately adjacent
to the pipe rack and storage tanks, phosphorus, sulfate and dissolved solids groundwater
concentrations were elevated. Elevated phosphorus, sulfate and dissolved solids concentrations
also existed at further downgradient monitor wells MWTF 2B and MWTF-3B. Pumping tests
performed in the tank farm indicated leakance values for the clayey layers above and below the
confined sand layer of 0.0045 and 0.0009 gal/day/ft3, respectively. For the prevailing hydraulic
head differences across the clayey layers above and below the confined sand at the time of the
leaks of 2 to 3 and 5 to 6 feet, respectively, corresponding natural recharge rates of 2 to 3 gpm and
about 1 gpm over the 8-acre tank farm area were calculated.
Croatan Formation: The direction of groundwater flow in the Croatan formation at the time of the
leak incidents (Figure 2-6 in Attachment I) was opposite the direction of flow in the overlying
surficial sand and confined sand layers, and was generally south -southeastward with a gradient
of about 0.0023 feet/foot and relatively slow horizontal seepage velocity of about 3 feet/year. At
downgradient monitor well MWTF-1 C, the phosphorus, sulfate and dissolved solids concentrations
were relatively low, indicating that groundwater impacts did not exist in the Croatan formation in
the southern portion of the tank farm (Figure 3-3 in Attachment I). At upgradient monitor wells
MWTF-2C and MWTF-3C and well -point sampling location WPTF-1 D, the phosphorus, sulfate, and
dissolved solids concentrations were elevated. At these locations, the phosphorus concentrations
were generally lower (except at WPTF-1 D) than occurred in the overlying confined sand layer, but
the sulfate and dissolved solids concentrations were somewhat greater. Because the direction of
groundwater flow in the Croatan formation was south -southeastward, away from monitor wells
MWTF-2C and MWTF-3C, it was expected that impacts in the Croatan formation at these wells
occurred from downward seepage from the overlying confined sand layer.

PCS Phosphate Company, "inc.
File Number 02-051 -4-
In order to contain groundwater in the confined sand layer and any potential future leaks/spills into
the surficial sand layer, the supplemental remedial action plan included the installation of an
approximately 750-foot long soil-bentonite cut-off wall along the north side of the tank farm. The
cut-off wall was excavated through the surficial and confined sand layers and keyed into the top
of the clayey sand to plastic clay layer underlying the confined sand layer (Figure 4-2 in
Attachment I). The cut-off wall was installed to curtail and capture the northward flow of
groundwater within the surficial aquifer across the tank farm. Groundwater flow that was naturally
occurring across the tank farm was collected in a ditch in the surficial sand layer along the inside
of the cut-off wall, and by a series of seven withdrawal wells spaced on 100-foot centers in the
confined sand layer along the inside of the cut-off wall.
Modifications to Supplemental Remedial Action Plan
Upon review of the supplemental remedial action plan, the DEM in their letter of December 8,1989
requested some modifications to the plan. Responses to these concerns were addressed at a
meeting in their Washington, North Carolina regional office on January 18, 1990 and documented
in our letter of March 6, 1990 titled "Response to Deficiencies Noted by the DEM Concerning the
Tank Farm Supplemental Remedial Action Plan and Proposed Revised Remedial Action Plan".
The revised remedial action plan was essentially the same as presented in the October 1989
remedial action plan except that an injection and withdrawal well system was added in the Croatan
Formation to also actively clean-up groundwater in that formation from tank farm leaks/spills. The
revised remedial action plan was approved by the DEM on March 19, 1990. The design report for
the revised remedial action system was issued on July 31, 1990 and forwarded to the DEM.
Performance of Confined Sand Layer Withdrawal Well System
The confined sand layer withdrawal well system was designed to maintain a maximum piezometric
water elevation between wells of about 2 feet (MSL), creating a "low -point" in the potentiometric
surface of the confined sand layer along the inside (i.e., south side) of the cut-off wall. The
resulting zone of capture of the withdrawal wells encompassed the 700-foot by 500-foot (8-acre)
tank farm area. The withdrawal well system was designed to operate at 12 to 13 gpm, with flows
varying from about 1 gpm at the center well (SWW-4) to about 3 gpm at the two end wells (SW W-1
and SWW-7).
The confined sand layer withdrawal wells have been in operation since August 1991. Over the
11-year operating period, an estimated 40 million gallons of water have been withdrawn from the
confined sand layer. The typical potentiometric surface of the confined sand layer based upon
2001 and 2002 water level readings is presented on Figure 1. Water levels in the eleven
piezometers used to monitor the performance of the withdrawal well system are plotted on
Figures 2, 3 and 4. The reported withdrawal well system flow rates from 1998 through 2002 are
plotted on Figure 5. Groundwater quality at the seven withdrawal wells from quarterly sampling is
presented on Figures 6 through 12. Groundwater concentrations of total dissolved solids, sulfate
and total phosphorus measured in April 2002 are shown on Figures 13,14 and 15. A review of the
monitoring data indicates the following performance of the confined sand layer withdrawal well
system.

PCS Phosphate Company, plc.
File Number 02-051
-5-
• The typical 2001-2002 potentiometric surface of the confined sand layer (Figure 1)
shows that the withdrawal well system is operating satisfactorily to capture
groundwater within the limits of the tank farm. The withdrawal wells also capture
groundwater from outside the limits of the tank farm beyond the east and west ends
of the cut-off wall. Water level monitoring over the last seven years (Figures 2, 3
and 4) indicates that the water levels have remained relatively stable, varying about
±0.5 feet at each piezometer location, and that the general directions of flow have
remained relatively stable.
• The withdrawal rate was consistent with the design flow rate of 12 to 13 gpm
through the third quarter of 2000 (Figure 5). The withdrawal rate declined to 8 to
10 gpm in late 2000 through 2001, but the reduction did not adversely reduce the
zone of capture.
• Sampling at the seven withdrawal wells (Figures 6 through 12) indicates that the
withdrawal well system is still capturing groundwater with concentrations exceeding
the target clean-up levels for total dissolved solids and sulfate of 500 and 250 mg/I,
respectively. Consistent decreasing monotonic trends in constituent concentrations
are not generally apparent at the withdrawal wells. Typical concentrations
measured at the withdrawal wells and overall changes in concentration since the
start of pumping are listed below.
Parameter
Range of Change in
Concentration
Current Typical
Concentration
pH (std. units)
nc to +0.7
6.0 to 6.5
TDS (mg/I)
-250 to +375
750 to 1,750
SO4 (mg/I)
nc to +250
200 to 750
Total P (mg/I)
-100 to +30
50 to 100
CI (mg/I)
nc to -75
50 to 100
Where: nc denotes no change.
Although some reductions in constituent concentrations have occurred, the total
dissolved solids and sulfate concentrations are still above the target clean-up values
of 500 and 250 mg/I, respectively, and total phosphorus concentrations are still
elevated.
• Generalized contours of total dissolved solids, sulfate and total phosphorus in the
confined sand layer in April 2002 are shown on Figures 13, 14 and 15. The
measured concentrations indicate that groundwater with total dissolved solids,
sulfate and total phosphorus concentrations over 2000 mg/I, over 1000 mg/I and
over 100 mg/I, respectively, still exists within the confined sand layer below the tank
farm.

Gam/ 3--an as .-
r, _., d c\1/4.-
PCS Phosphate Company, inc.
File Number 02-051 -6-
Performance monitoring of the confined sand layer withdrawal well system indicates that the
system is performing its intended function. The withdrawal well system zone of capture
encompasses the tank farm area, is preventing contaminants from phosphoric acid spills/leaks from
leaving the limits of the tank farm, and continues to remove groundwater with elevated dissolved
solids, sulfate and phosphorus concentrations. Groundwater will continue to be removed by the
withdrawal well system until groundwater with dissolved solids and sulfate concentrations above
target clean-up levels in the overlying surficial sand layer and confining layer have been removed.
At the expect echar to of 2 gpm, operation of the confined sand layer withdrawal well
system will be - fired for on the order of another 10 years, although the actual time will be
determined by hen the target clean-up levels are achieved.
otV
ti
•t So
Performance of Croatan ormation Injection and Withdrawal Well System
The Croatan Formation injection and withdrawal well system was designed to operate with the
water level in the injection wells at Elevation 12 to 15 feet (MSL) and the water level between the
withdrawal wells at Elevation -1 feet (MSL). The injection system was designed to operate at 19
gpm, with flows varying from about4 gpm at the two end wells (CIW-1 and CIW-7) to about 2 gpm
at the center well (CIW-4). The withdrawal well system was designed to operate at 6 gpm, with
flows varying from about 3/4 gpm at the center well (CWW-4) to about 1 gpm at the two end wells
(CWW-1 and CWW-7).
The Croatan Formation withdrawal wells have been in operation since late September 1992. Over
the approximate 10-year operating period, an estimated 34 million gallons of fresh water has been
injected into the Croatan Formation. An estimated 23 million gallons of groundwater has been
removed by the withdrawal wells.
The typical potentiometric surface map of the Croatan Formation based upon 2001 and 2002 water
level readings is shown on Figure 16. Water levels in the four piezometers used to monitor the
performance of the injection/withdrawal well system are plotted on Figure 17. The reported
injection and withdrawal well flow rates from 1998 through 2002 are plotted on Figure 18.
Groundwater quality at the seven withdrawal wells from quarterly sampling is presented on Figures
19 through 25. Groundwater concentrations of total dissolved solids and sulfate measured in April
2002 are shown on Figures 26 and 27. A review of the monitoring data indicates the following
performance of the Croatan Formation injection/withdrawal well system.
• The typical 2001-2002 potentiometric surface of the Croatan Formation (Figure 16)
shows that the injection/withdrawal well system is operating satisfactorily to capture
groundwater within the limits of the tank farm. The withdrawal wells also capture
groundwater from north of the tank farm and from beyond the east and west ends
of the line of withdrawal wells. The injected fresh water flows northward toward the
withdrawal wells as well as southward and radially outward from the two ends wells
(CIW-1 and CIW-7). About one-third to onelf of the injected water is captured
by the withdrawal wells. The remaining injection water flows away, mostly
southward, from the tank farm. Water level monitoring over the last seven years
(Figure 17) indicates that the water levels have decreased as the injection rate
19z,,,, declined. The relative elevation of the water levels in the piezometers remained
ynNF
<%3q-;

PCS Phosphate Company, inc.
File Number 02-051
-7-
consistent, however, indicating that the direction of flow toward the withdrawal wells
was maintained.
• The injection and withdrawal rates have averaged about 7 and 5 gpm, respectively,
over the operating period based upon reported total injection and withdrawal
volumes of 34 and 23 million gallons. More recently, over the last 41/2years (Figure
18), the injection and withdrawal rates have averaged 9 and 6 gpm, respectively.
The average withdrawal rates have been consistent with the design rate of 6 gpm.
The average injection rates have been 40 to 50% of the design rate. The
performance of the injection wells has been satisfactory at the lower injection rates
since the zone of capture of the withdrawal wells still encompasses the tank farm.
• Sampling at the seven withdrawal wells (Figures 19 through 25) indicates that the
withdrawal well system is still capturing groundwater with concentrations exceeding
target clean-up levels for total dissolved solids and sulfate. Decreases in
constituent concentrations are apparent, however, at wells CW W-3, CWW-4, CW W-
5 and CWW-6. General changes in concentrations at the withdrawal wells are listed
below.
Well
Parameter
TDS
(moil)
SO4
(mq/I)
CI
(mg/I)
CwW-1
AC
+250
+1350
-25
C
1750
750
75
CWW-2
AC
-250
nc
nc
C
2000
750
100
CWW-3
AC
-375
-300
+95
C
1875
550
175
CW W-4
AC
-250
-50
+25
C
2000
650
125
CWW-5
AC
-750
-300
-50
C
1500
450
75
CW W-6
AC
-625
-200
-25
C
1375
450
100
CW W-7
AC
nc
+100
-25
C
750
200
75
Where: nc = No change; AC = Change in concentration over operating period;
and C = Current concentration.
As shown, total dissolved solids and sulfate concentrations have decreased 250 to
750 mg/I and 50 to 300 mg/I, respectively, at wells CWW-2 through CWW-6. The
overall average total dissolved solids and sulfate concentrations at the center five
withdrawal wells are currently about 1800 and 570 mg/I, respectively, versus initial
average concentrations of 2200 and 750 mg/I. Chloride concentrations have
generally not increased, indicating that the withdrawal wells have not caused

PCS Phosphate Company, inc.
File Number 02-051 -8-
brackish water to enter the Croatan formation below the tank farm. Phosphorus
concentrations have generally decreased slightly, and currently average about 5
mg/I, versus about 5 to 10 mg/I initially.
• Generalized contours of total dissolved solids and sulfate in the Croatan Formation
in April 2002 are shown on Figures 26 and 27. The measured concentrations
indicate that groundwater with total dissolved solids and sulfate concentrations over
3000 and 1500 mg/I, respectively, still exists within the Croatan Formation below the
tank farm. �t- `-C G1) La
The water level in the Croatan Formation is lower than the water level in the overly ng aquifers, and
hence, groundwater in the Croatan Formation cannot migrate upward into overlying aquifers. The
injection well system has caused the potentiometric water level in the Croatan Formation below the
tank farm to rise by about 1 to 4 feet. The hydraulic head difference between the Croatan
Formation and underlying Castle Hayne aquifer, across the 100-foot thick Yorktown-Pungo River
aquitard, has typically been between 20 and 30 feet in the tank farm area over the last 10 years.
Hence, the small rise in the potentiometric water level in the Croatan Formation of 1 to 4 feet is
minor in comparison to the prevailing hydraulic head difference across the aquitard, and did not e.1
result in an appreciable increase in the amount of downward recharge toward the Castle Hayne
aquifer. Operation of the injection well system, therefore, has not caused any significant migration
of groundwater from the Croatan Formation into other overlying or underlying aquifers.
The injection/withdrawal well system is being operated such that the zone of capture of the
withdrawal wells encompasses the tank farm. Hence, groundwater below the tank farm cannot
migrate into previously uncontaminated portions of the Croatan Formation. Groundwater at the line
of injection wells, prior to operation of the system, was not impacted by spills/leaks from the tank
farm and was characterized (at monitor well MWTF-1 C) by total dissolved solids, sulfate, chloride
and total phosphorus concentrations of 540, 65, 55 and 0.3 mg/I, respectively. Hence, groundwater u
initially abutting the south side of the tank farm that was caused to flow away from the tank farm
by the injection wells, and not captured by the withdrawal wells, was not contaminated. The
injection wells, therefore, did not cause contaminants in the Croatan Formation below the tank farm
to migrate horizontally into previously uncontaminated portions of the formation.
After approximately 10 years of operation, the total dissolved solids and sulfate concentrations at
the withdrawal wells have decreased on average from 2200 to 1800 mg/I and 750 to 570 mg/I,
respectively. For the reduced overall average injection and withdrawal rates of 7 and 5 gpm,
respectively, and accounting for 1 gpm of recharge from the overlying soils, a reduction in total
dissolved solids concentration of about 800 mg/I, from 2200 to 1400 mg/I, and a reduction in sulfate
concentration of 450 mg/I, from 750 to 300, mg/I, would have been expected after 10 years of
operation. Although the decrease in total dissolved solids and sulfate concentrations have been
less, about 40 to 50%, than originally expected at the withdrawal wells, the system is still
beneficially causing the clean-up of groundwater in the Croatan Formation. It is anticipated that
an additional 10 to 15 years of system operation will be required to reach target clean-up levels,
although the actual time operation of the system is required will be determined by the performance
of the system.
s.�

PCS Phosphate Company,, nic.
File Number 02-051
-9-
Conclusions and Recommendations
A review of the operation and performance of the tank farm remedial action system, as
documented by 10 years of monitoring data, yields the following findings.
• The confined sand layer withdrawal well system is performing its intended function.
The withdrawal well system zone of capture encompasses the tank farm area, is
preventing groundwater impacted by phosphoric acid leaks/spills from leaving the
limits of the tank farm, and continues to remove groundwater with elevated
dissolved solids, sulfate and phosphorus concentrations.
• The confined sand layer withdrawal well system will need to be operated until
groundwater with elevated dissolved solids and sulfate concentrations in the
overlying surficial sand and confining layers has been removed. It is expected that
operation of the confined sand layer withdrawal well system will be required for on
the order of another 10 years. The actual time of operation will be determined by
when target clean-up levels for dissolved solids and sulfate are achieved.
• The Croatan Formation injection/withdrawal well system is being operated
satisfactorily, and is performing its intended function with the zone of capture of the
withdrawal wells encompassing the tank farm area. Hence, groundwater below the
tank farm cannot migrate laterally into previously uncontaminated portions of the
Croatan Formation. Groundwater initially abutting the south side of the tank farm
that was caused to flow away from the tank farm area by the injection wells was not
contaminated.
• The potentiometric water level in the Croatan Formation is lower than the water
level in the overlying aquifers (i.e., confined sand and surficial sand layers). Hence,
the injection system is not causing groundwater in the Croatan Formation to migrate
upward into overlying aquifers. The injection well system also has not caused any
appreciable increase in the amount of downward recharge toward the Castle Hayne
aquifer.
• Operation of the injection well system at injection rates less than the design rate is
satisfactory, and can continue as long as water level monitoring demonstrates that
the zone of capture continues to encompass the tank farm area.
• The Croatan Formation injection/withdrawal well system will need to be operated
for an additional 10 to 15 years. The actual time of operation will be determined by
when target clean-up levels for dissolved solids and sulfate are achieved.
• The location and number of existing piezometers and monitor wells were selected
and are adequate to document that the Croatan Formation injection/withdrawal well
system is being operated satisfactorily and that the zone of capture of the
withdrawal wells encompasses the tank farm.

i
PCS Phosphate Compan},',;:.,.
File Number 02-051
-10-
The demonstration of the above findings, based upon the performance monitoring information
presented in this report, should be sufficient to address the issues raised by Underground Injection
Control concerning operation of the injection wells.
The following continued monitoring is recommended based upon review of the performance
monitoring data.
• Continue daily (on normal work -day) recording of injection and withdrawal flow
rates.
• Continue quarterly water level measurements in piezometers, monitor wells and
withdrawal wells.
• Reduce groundwater quality sampling in all wells from quarterly to twice per year.
The reduction in groundwater sampling is justified since 10 years of monitoring has
demonstrated that the declines in groundwater concentrations will be relatively slow,
and that twice per year sampling will be adequate to monitor the long-term clean-up
of groundwater.
We trust this report will satisfy the concerns of Underground Injection Control. Please contact us
if you have any questions or require additional information.
Very truly yours,
A&A ENGINEERING, INC.
Thomas S. Ingra,PP.E.
Senior Proje Manager
tn:E. Garlanger, Ph.D., P.E.
Principal .
North.Carolina Registration No. 9046
TSI/JEG/td
TAProJects120D21o2-051\Response Ltr to NCDENR Comments.t.wpd

PCS PHOSPHATE ENV AF
PAGE 02/03
e2/22/2002 14:45 2523224444
oFW TeR
9_
-i
•-c
NGchael P. Easley. Governor
- � William G. Mask., Seactary
North Carolina Department of Environmentand Nahual Resources
Gregory 1, Thorpe, Ph.D,
Acting Director
Division of Water Quality
GROUNDWATER SECTION
February 19,2002
Mr. Daniel Winstead
PCS Phosphate
P.O. Box 48
Aurora, North Carolina 27806
RE: Renewal application for Injection Well Permit WI0700012
Dear Mr. Winstead:
In the process of reviewing your application for renewal of the subject permit, we have developed some
concerns about the injection well system you are operating. In order for us to perform a complete review and
approve your permit application, we will need additional information from you regarding the injection well
system.
Our first concern is that the injection well system may be causing contamination to migrate into previously
uncontaminated portions of the Croatan Formation or other aquifers. A review of information submitted to the
Groundwater Section by PCS and its predecessor, TexasGulf, shows that the full extent of contamination and
the hydraulic impact of the injection and extraction system have never been delineated. In order to determine
whether or not the injection system is compromising other portions of the Croatan Formation or other aquifers,
please provide the following information:
• Horizontal and vertical extent of dissolved solids and sulfate contamination (including overlying
aquifers) to below 2L standards
• Potentiometric surface maps of the Croatan formation showing the full extent of altered groundwater
heads caused by the injection and extraction system.
Second, we are concemed that the injection -extraction system is not achieving the predicted remediation goals.
The Remedial Action Plan submitted in 1989 for this system estimated a clean-up time of 20 years. A review of
extraction well sample results submitted to the Groundwater Section since system start-up in 1991 doesnot
show any consistent decreases in the level of contamination in the Croatan Formation. In order to clarify the
purpose and effectiveness of this system, please provide an assessment of the current effectiveness of the
system and re -assessment of the length of time required to achieve clean-up of groundwater in the Croatan
Formation.
N. C. Division of Water Quality 1636 Mail Service Cana Raleigh, NC 27699-1636 [phone]
Groundwata Section 1 800 623-7748
Customer Service

02/22/2002 14 4s 252324444; PCS PHOSPHATE ENV;AF
Pa�e
Mr. Danny Winstead, PCS Phosphate
•
PAGE'03a9-
We look forward to receiving your response so that we may perform a proper review of your pelt& application.
If you have any questions regarding this request please contact me at [phone] or [e-mail].
Sincerely,
Evan 0. Kane
ProgramManager
Underground Injection Control
cc: Willie Hardison, Washington Regional Office
UIC-CO files
N. C. Division of Water Quality 1636 Mail Serviec Cents Raleigh, NC 27699.1636 (919) 733-3u1
Groundwater Section
Customs Service
1800623-774B

CADD FILE: T:\CORPORATE\02\02-051\02051-01.DWG DATE: 08/27/02 REVISED BY: BTW
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11.2 SPILL LOCATIONS
SPZ-2
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CUT-OFF WALL
e1.0sw
SWW-3 E—
MWTF-2B \
PRE -PUMPING WL04.5'
rn
sww-s
qe 1.^
1.0 E SPW
1.9'
2'
APR. 2002 WL•2.7' I
SPZ 8
1 25'
L J
J
POTENTIOMETRIC
WATER LEVEL IN
�SO
-.—LIMITS OF
TANK FARM -,
1.4
6'
7'
4' �\
0
O(x
O
SPZ-5 SPZ-F
1.9' 1.2 a
swW-e e 1.4.
9.4
2
MWTF-3B'�
PRE -PUMPING WL•3.8'
rTn
12.1
J
sww-7• V 4.5'
SPZ--A
u
APR. 2002 WL•1.9'
A
12.1 5
MWTF-IBm "10.9
PRE -PUMPING WL41.4'
APR. 2002 WL•9A'
Pr) 01'00
O
17.6
FLOW
DIRECTIOrTh
x 17.1
, 105.
17.7.
GROUND SURFACE
IN FEET (MSLI
8.6
O 75 150
SCALE:—T'•150'
LEGEND
• PIEZOMETER
O MONITOR WELL
e WITHDRAWAL WELL
OUTFALL
CANAL
WL-4'
12.9
TYPICAL 2001-2002 CONFINED SAND LAYER POTENTIOMETRIC SURFACE

ELEVATION, FT (MSL)
ELEVATION, FT (MSL)
ELEVATION, FT (MSL)
ELEVATION, FT (MSL)
8
7
6
5
4
3
2
1
7
6
5
4
6
5
4
3
•
TYPICAL WATER LEVEL 6.0' ± 0.5'
•
PIO
r�.
SPZ-1
•
{
--
M.
•
TYPICAL WATER LEVEL 2.9' + 0.5'
I .,
SPZ-2
•
•
TYPICAL WATER LEVEL 5.6' ± 0.5''
•,.
r<.
0.4
SPZ-3
•
•
w
•
TYPICAL WATER LEVEL 4.8' + 0.5'
SPZ-4
O!%
1996 1997
1998
1999 1 2000
2001
2002
WATER LEVELS IN CONFINED SAND LAYER
AT PIEZOMETERS SPZ-1 THROUGH SPZ-4
RENEWAL OF INJECTION WELL PERMIT
TANK FARM REMEDIAL ACTION PLAN
PCS PHOSPHATE COMPANY
AURORA, NORTH CAROLINA
DRAWN BY. KSP aan Q I DAEE. 08/26/02
FEE NO.: FIGURE.
02.051 2

1
ELEVATION, FT (MSL)
ELEVATION, FT (MSL)
ELEVATION, FT (MSL)
ELEVATION, FT (MSL)
4
3
2
1
3
2
1
0
3
2
1
- i•
11
•
1-1- I II 111111
-TYPICAL WATER LEVEL 2.3' ± 0.5 - --
•
4/10
•
SPZ-5
0
7
6
5
4
3
•.
•
J—
—TYPICAL WATER LEVEL 1.9' ± 0.5'
•`
•
SPZ-6
•
-r-
4
s�.
•
c
TYPICAL WATER LEVEL 1.5' ± 0.5'
;M
SPZ-7
i
t rr-
•
TYPICAL WATER LEVEL 5.2 ± 0.5'--s-
SPZ-8
L.J
•
1996
1997 1 1998 1 1999
2000
2001
2002
WATER LEVELS IN CONFINED SAND LAYER
AT PIEZOMETERS SPZ-5 THROUGH SPZ-8
RENEWAL OF INJECTION WELL PERMIT
TANK FARM REMEDIAL ACTION PLAN
PCS PHOSPHATE COMPANY
AURORA, NORTH CAROLINA
DRAWN BY: KSP,
NM NO.:
02-051
lat. 08/26/02
3

ELEVATION, FT(MSL)
ELEVATION, FT (MSL)
4
3
2
1
8
7
6
5
4
co
3
Z
O
2
1
TYPICAL WATER LEVEL 2.7' + 0.5' t +
_�
E
:.. SPZ-9
•
i'
•
rosa
TYPICAL WATER LEVEL 6.7 + 0.5'
•
SPZ-10
•
41,
••
1 I'1 I-:::'.::�
"TYPICAL WATER LEVEL 2.3' + 0.5'
•
�So
eta
SPW
1996
1997
1998
1999
2000
2001
2002
WATER LEVELS IN CONFINED SAND LAYER
AT PIEZOMETERS SPZ-9, SPZ-10 AND SPW
RENEWAL OF INJECTION WELL PERMIT
TANK FARM REMEDIAL ACTION PLAN
PCS PHOSPHATE COMPANY
AURORA, NORTH CAROLINA
o. BY: KSP Y: �IA� I DAIS08/26/02
FILE No.:
OMEN BY pr \ 4
02-051 I N.�7 Y�.i.

FLOW RATE (gpm)
20
16
12
8
4
2
•. •t •.
••
I_
DESIGN FLOW RATE: 12+013 gpm
•'••
•..,
•
•
•.••
•i
•
••
•
Er
1998
1999
2000
2001
2002
CONFINED SAND LAYER
WITHDRAWAL WELL SYSTEM FLOW RATE
RENEWAL OF INJECTION WELL PERMIT
TANK FARM REMEDIAL ACTION PLAN
PCS PHOSPHATE COMPANY
AURORA, NORTH CAROLINA
D WNBY: KS aic
FIEND.:
02-051
lonh. 08/26/02
FIGURE:
5

•
a N
❑
w
u_
W
O E
Z
O
0 E
L
U
0
n.
O
❑
J O "o
O E
J
(Ono
H~ 1,000
0
3
5
5
4
•
•••
•• •
I i I
• • '•
•
•
• I
• •
••
_."..;
3,500
3,000
2,500
2,000
1.500
1,000
500
J
•
El I
•, •
1 t
,
•
-•
•
•
•
•
I
2,500
TOTAL PHOSPHORUS
E
0
co
1,500
500
1,000
750
500
250
0
•
•
• •I
•
•
el! ... . •
• •
wino
•.•
•
•
••
• •;
•
•
•
•
300
200
co
d 100
•
•
•
•
•
•
•
•
•
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•
• •I
0• •
200
150
100
50
ti
•
III
•
••
• • I
•
• i • •
•
•
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
SUMMARY OF WATER QUALITY AT SWW-1
RENEWAL OF INJECTION WELL PERMIT
TANK FARM REMEDIAL ACTION PLAN
PCS PHOSPHATE COMPANY
AURORA, NORTH CAROUNA
FILE
NO.: : KSP IaEa: 15: loos 09/17/02
02-051 y�1' B1(Q�'(4.u0/A, FIGURE: 6
Y

L_.
8
7
0
W 2 e
u_ ca.
7.*
• •
•
•
•
•
• 1
• i b
• •
• •
cri
5
LL)
0
Q 4,000
ET
3,500
7 E 3.000
Zy asap
V2 2,000
U 3 1,500
LL
U 1,000
a 500
CO
0 2,500
w
J 2,000
• O E
J 1,500
❑ O a)
J (/) 0
FH 1,000
O -
• •
• • • •
Y
•.
♦°
•
♦
co
co
E
E
0
CO
CC
0
O E
0 0
O
0
O E
U
•
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• ;
!
•
•.
0
•:
•
• .
Pi •
•
•
0; •
•
•
•
1.
750
500
250
900
200
100
200
150
100
50
•
d
•
• •
•
• •
•
•I
•
•
rr
•
r-!
♦
0
•
•
• • • •
•.
•
•
•
•
•. •
•!
•
•
•.
■
•
r
•.
• • •
••
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
SUMMARY OF WATER QUALITY AT SWW-2
RENEWAL OF INJECTION WELL PERMIT
TANK FARM REMEDIAL ACTION PLAN
PCS PHOSPHATE COMPANY
AURORA, NORTH CAROLINA
0aartor: KSP IBY: 0>1E 09/17/02
FIE NO.: � _ 1 FIGURE: 7
02451

f ,
TOTAL DISSOLVED
J
7
0
w a
w
0
4.000
3,500
E 3,000
Z y 2.500
(O,) L 2,000
3 1,500
lL
V 1.000
500
rn
2.500
4
2,000
O
E 1,500
N O
U
0
CC
10
= C
0 E
0_ a
O
w
0
O E
0
500
•I
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fi
•
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1
•
•
Li •
•
•
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l
•
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I
I
•
•
•
•
•
• I I
•! +I
•I
1
i
750
500
250
0
300
200
100
r
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1
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I
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1
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200
150
100
50
•
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III
1
0
•'•
I
••
•r
•.••
•
•
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
SUMMARY OF WATER QUALITY AT SWW-3
RENEWAL OF INJECTION WELL PERMIT
TANK FARM REMEDIAL ACTION PLAN
PCS PHOSPHATE COMPANY
AURORA, NORTH CAROLINA
muvmer: KSP j�(0a0/�yy � IwT3 09/17/02
m2x 02-051 �I V: MORE: 8

w
TAL DISSOL
0
w
LL
U
4,000
3,500
0 0 3,
Z 2,500
Ut 2,000
E 1.500
L
1,000
d500
O E
Ow 1.500
0) ❑
- 1,000
5
7
ae
5
4
•
I•
•
T
•I
6
•
•. •
IJ I
I
•
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II
I
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•
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111
0
-4
2,500
2,000
500
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•
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I
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c 750
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500
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o
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0 U
250
'II
•
r•
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•
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•
t •
y
•I
• •
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•
I
•• •
•
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300
200
100
200
150
100
50
•
•
1
•
1
•
•
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:
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•: I
7'.
•
a a
-I-
••
1 _ 0 •
•
•
•
. • •
•f
• •• •
• • I
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
SUMMARY OF WATER QUALITY AT SWW-4
RENEWAL OF INJECTION WELL PERMIT
TANK FARM REMEDIAL ACTION PLAN
PCS PHOSPHATE COMPANY
AURORA, NORTH CAROLINA
DM BY: KSP OFEcq•rst 1. 091n/02
FE 02-051 9�j"�I'.r�� FIGURE' 9

a
U
Z 0
O L
O E
Li 3
W
CO
0
(J zoo°
1/1 • E 1.500
• O
Quo
0
5
7
-1.
•I
•
The
.L
0-
•
1 1
ill
•
1
••
•
I_
•••
•
•
i I
—.•1
•
4
O.00D
.i-1.....
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1
I_j_--.
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_i..-..'it
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I
3,500
•''
Y!-�•
I
1 :
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• ; 1
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a
250
I •
•
• • or
L-_
•
i-
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1•
I •
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••
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r-
•
r
r
500
TOTAL PHOSPHORUS
Ol
E
a
750
•
I •�
•..
•
•1
•
•
•
•
I 1 !
500
200
100
1
•
E
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lI
•
I_.-
•-•-1-
•li1
200
150
100
50
I I _{
I
1
L1
•
1
•
•11:
•
•.-i --•._s i i ¥ io
••r
•I•
•• E
t i..._r_
1.
II
i
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
SUMMARY OF WATER QUALITY AT SWW-5
RENEWAL OF INJECTION WELL PERMIT
TANK FARM REMEDIAL ACTION PLAN
PCS PHOSPHATE COMPANY
AURORA, NORTH CAROLINA
DRAWN °r: KSP luaaao° lw15. 09/17102
02-051
FILE•: 0 1

0
-J
LL
W
0
Q 4.000
0 9,500
OE 3.000
Z 0 2,500
VE 2,000
is _ 1.500
LL
U
d500
1n
o 2,500
w
J
C
co w m
N J E 1,500
❑ en
_1N CI t.oa7
O
9
7
0. e
1
4 1•
i !
♦ 1 1
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I
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H-f
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E
1
I
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1
Li
11
■
• .
r 1 .
• I •
•
FL.
1
1
1
I I7
• ` •
5
4
500
1,000
750
500
250
-1-
149.
1110-1.
•
•
•
L-L-
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1
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1 1-7 i
rl I
r}••
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1
1
1
1
1
•• 4 1
1
•
1
•
1 • L. •
♦
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200
50
0
T
1
•
•
1 •.
1
• • • •
r•I
1
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1
•
•
1
♦
• _ •
•
•
1
i• •
••
L
•! 1
1
1
-1 1
F
1
1991
1992
1993
1994
1995
1996
1997
1998
1999 2000
2001
2002
SUMMARY OF WATER QUALITY AT SWW-6
RENEWAL OF INJECTION WELL PERMIT
TANK FARM REMEDIAL ACTION PLAN
PCS PHOSPHATE COMPANY
AURORA, NORTH CAROLINA
u3nxwer: KSP acme. yMf �7W1IwTE. 09/17/02
02-051 ! 1.01�-_I ��awe. 11

0
O_
LL
W
0
LQ 9,000
9,500
E 9,000
1-1
Z m 2,500
Ot
U 2,000
1,500
U isoo
0- 500
CO
2,500
LLJ
J
2,000
C E
O U 1,wo
m 0
1,000
Q
8
7
•
5
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•
1 • • •
• I 6 •
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or 6
a.
•
1 i i
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W
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E
a
co
9
500
1,000
750
500
250
• • • •
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•
•
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• • • 6
•.
0
•
'.
•
I•
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I.•
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• 0 0 k.
• : • i
••
• • •....•
co
900
CC
0
2
2 E zao
a a 100
O
❑ o
O E
= U
U
200
150
100
50
•MiI
• • •
• •
• • • L
••
•
•
•
•
9
•
1 •
•
• • •
•
•
1 • •
• • y
•
• • • •
•
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
SUMMARY OF WATER QUALITY AT SWW-7
RENEWAL OF INJECTION WELL PERMIT
TANK FARM REMEDIAL ACTION PLAN
PCS PHOSPHATE COMPANY
AURORA, NORTH CAROLINA
aavmer: KSPa<�a0�n+ Iwur. 09/17/02
02-051 - 1 "` 12

CADD FILE: T:\CORPORATE\02\02-051\02051-13.DWG DATE: 08/2S/02 REVISED BY: BTW
Np
0
A
GJ
zm
» F
aoir
O so
a= ; 0
0
z•0
oxm00
xmza
ao
Z
mc0c
O
m
2z zr
s<-am
a9
y
SPZ-2
8WW-1 1640
1444
8PZ-
1780
14&ieJr
53g"'a/.0
L
rn
CUT-OFF WALL v
8WW-5 8PZ-5
980
184463 sw
1772 L
w-a L
1888
SPW
L 2240
'
S860
2eo , r
TIONS row
‘',„'x11.4 10p0 1
>MWTTF-1
28:
SPZ-8
1350
Fin n xlo.e
TOTAL DISSOLVED
O O
SOLID$
�U IN m9/I
I 166 I I
0
rrn
12.1
SPZ-8
899
e 8Ww-7 "
Eilza
8PZ-10
820
17.6
x 11.3
8.6x
APRIL 2002 CONFINED SAND LAYER GENERALIZED TOTAL
DISSOLVED SOLIDS CONCENTRATION CONTOURS
0
A
u
75
150
SCALE:—1"4150'
LEGEND
O PIEZOMETER
O MONITOR WELL
e WITHDRAWAL WELL
OUTFALL
CANAL
12.9

1PAI
CADD FILE: T:\CORPORATE\02\02-051\02051-14.DWG DATE: OB/28/02 REVISED BY: BTW
o�^
Ns
m
g
a
-1
SPZ-3
933
SPZ-1
SPZ-2
1171
PZ-
SWW-1 e
692E SWW-2
999
838
500
8WW-3 ES W-4 L
487 :05
73
o ill `SPILL LOCATIONS
\SOS
LIMITS OF
TANK FARM
15 %I`i :
11 waft
SNL-
1225
0
0
SWW-5 SPZ-6 9PZ-6
848 e933 654
8WW-8e
890
1 .4
8PW
113
5
250
0
SWW-7
212
e
004 CONCCEN IA 10 12.1
INmk III ,
MW3TS-1B
00 0
0
0
R10.8
0
u
rrn K 11.3
12.1
CP
SPZ-8
484
17.6
• 17.1
10.5�
0
76
150
SCALE:—1".150'
LEGEND
O PIEZOMETER
O MONITOR WELL
e WITHDRAWAL WELL
SPZ- 0
Ir '780
I
OUTFALL
CANAL
12.9
APRIL 2002 CONFINED SAND LAYER GENERALIZED SULFATE CONCENTRATION CONTOURS

CADD FILE: T:\CORPORATE\02\02-051\02051-15.DWG DATE: 08/2B/02 REVISED BY: BTW
g
01
0
0
N
SPZ
200
i31�3 ry�iL:+C•y
SABRES,L
v
SPZ-2
27
]❑
CUT-OFF WALL —
sww-1-.p' e
9 118[ SWW-2 SWW-3
51004 60 80
ai 0
u
11.2.
100
J
SWW-5
39
0
SPZ-5 SPZ-6
89 28 (1
e n sww-e e
SWW-4 23
50
107
rR1
12.
J
SPZ-9
/ 188
SPILL LOCATIONS
—LIMITS OF
TANK FARM
5
-4N 1
.00
x11.4
M
SPW
85
0
o'°
WTF-1B�
8.3
000
�00
.10.8
TO- TAL• L
PHOSPHOROUS
UWOm
0
W-7
52
u
SPZ-8
2.1
r 11.3
.72.2
11 1
SPZ- 0
29
17.6
8.6.
APRIL 2002 CONFINED SAND LAYER GENERALIZED
TOTAL PHOSPHOROUS CONCENTRATION CONTOURS
0
76
150
SCALE:—1"0150'
LEGEND
O PIEZOMETER
O MONITOR WELL
e WITHDRAWAL WELL
OUTFALL
CANAL
K 12.9

CADD ALE: T:\CORPORATE\02\02-051\02051-16.DWG DATE: 08/28/02 REVISED BY: BTW
Ng
0�
gMWTF 2Cbat a+i"a;l i1;F
.P.RE=PUMPING
APB: 2002 WL-€0.1
ilia �' it ":
CPZ-2 0
-0.2
x11.2 SPILL LOCATIONS
CIW-2
1
14
--LIMITS OF
TANK FARM
MWTF-3C = I
PRE -PUMPING WL4-0.8
APR. 2002 WL.0
0
u
O
i \ _
CWW-4-1.5 CWW-8
--1.0 -2.4 'min
2.27WW-6 2. rm
-0.5
DIRECTION
POTENTIOMETRIC WATER 12.1
ELEVATION IN FEET (MSL)
1o.8 • CIW-7
MWTF-1C rn
PRE -PUMPING WL--1.3
APR. 2002 WLr2.9
rrn x11.3
12.
J o
CWW-7 f�
l n
17.6
8.6
17.7
WL-+14' IN1
INJECTION WELLS (TYP.)
A
0
150
SCALE:—1"-150'
LEGEND
O PIEZOMETER
O MONITOR WELL
Q WITHDRAWAL WELL
S INJECTION WELL
OUTFALL
CANAL
WL-4'
12.9
1-1
AVERAGE 2001-2002 CROATAN FORMATION POTENTIOMETRIC SURFACE

ELEVATION, FT (MSL)
ELEVATION, FT (MSL)
ELEVATION, FT (MSL)
4
3
2
1
0
2
1
0
1
INJECTION FLOW RATE (gpm)
12-14
9-10
6-8
8-10
12+
- r-• •
•
•M:
-t-
4•7-
4-
1-
•
•
-r
-f
N
•,,
a
•_
CPZ-1
s.
1—
4
•
. f
•
•
•-
.•-
•
r-
•
•
S.
•-
L�
0i itt
CPZ-2
fel
1
• i
3
2
1
0
2
2 - 1
z 0
0
w
-2
•
w
et
•: :-•
f
CPZ-3
—
M
latt
•.
1-
_a-
L_
1
•
•
•i'•-
-J_
•
•
H
-i-
E
40
•-1
rr
.$
•.
CPW
4_
4
el
•`
1996
1997
1998
1999
2000
2001
2002
WATER LEVELS IN CROATAN FORMATION AT
AL OF INJECTION WELL PERMIT
PIEZOMETERS CPZ-1 THROUGH CPZ-3 AND CPW TANKV FARM REMEDIAL ACTION PLAN
PCS PHOSPHATE COMPANY
AURORA, NORTH CAROLINA
DRAWN BY: KSP Icy j(9 IwTE. 09/17/02
`°F"°` r-I ROWE
02-051 17°

FLOW RATE (gpm)
20
16
12
8
4
2
120
100
80
a. 60
40
20
DESIGN INJECTION
° i RATE - 19 gpm
0000.. j--o--- ___
° on.
•
• ;
O INJECTION FLOW RATE, Qi
• WITHDRAWAL FLOW RATE, Qw
i••I •••.: i•
•••i •• •t
DESIGN WITHDRAWAL
..-...-RATE = 6 gpm..................
•
0
••
o0I
••di
0
°0 0
• °
oc'••
0 0 0
0
••
• • •
•
0
••• •
• •
00
•
•
•
00
••
•
■
■ ■ I■
•
■
■
•• j DESIGN (Qw / Qi) = 32%
■
■
•
•
•
■ ■
■
■
■1 •
■ 0.
1998
1999
2000
2001
2002
CROATAN FORMATION
WITHDRAWAL AND INJECTION FLOW RATES
RENEWAL OF INJECTION WELL PERMIT
TANK FARM REMEDIAL ACTION PLAN
PCS PHOSPHATE COMPANY
AURORA, NORTH CAROLINA
MAMMY. KSP I caner �1 Iw,E 08/26/02
oz-osi CL -1 twin` 18

8
7
4
•
•,
•
TI
•
•41
+I
I
•
•
1
w
U
3.500
j 3.000
ZN 2.500
O o
U E 2,000
U
LT a 1,500
w
a 1•
❑ 2.500
((J
0) ❑
0 O Co
1.500
J O 0
I 1,000
O
nct E
re
m U
TOTAL PHOSPHORUS
500
750
I
1
•
•
1
fly
Li f-
T
• ••
•
•
I.
1
r
•
• • 1
250
0
50
•
•
•'
•;
• • 1 •
1
•
1
•
•
_
1
(
• •
•_ —•
I
L
•
••
_
t
t
•
i=
l
c.
30
E
0_ 20
10
-r"
L
1t
300
W 250
❑ c
Q O1 200
O E
150
U U
50
0
• •
•
•_L
• - • •
r
•
•
•
• • • s
••,
•__
•_.
.4.... __L.
1
•
--
1
1-
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
SUMMARY OF WATER QUALITY AT CWW-1
RENEWAL OF INJECTION WELL PERMIT
TANK FARM REMEDIAL ACTION PLAN
PCS PHOSPHATE COMPANY
AURORA, NORTH CAROUNA
uuwxer KSP now Sr,2. 09/17/02
FeF 02-051 L. ROAR 19

1
1L
0
8
7
IA • 6
IA a
5
4
1-
•
L_
1_
••I •
• •
•
•
•••0
!II
? I
•I•
r
• •
r
I
U
3,500
3.000
❑ • V
z 2.500
O o
U E
lL 3 1,500
U
a
rn
CI 2.500
W
O c 2.000
2 E
V% J E 1.500
O O 0
H)- 1.o00
O
SOO
1,000
W
750
E
• 6 500
0
In CO
TOTAL PHOSPHORUS
250
0
i
i
I
T
•
(
I
•
•
•
• ? •
•
•
•
1.
Lam.
• I
rr y
• I
•
..".-...--.---,
•
•
H.
1
i
• • • •
• • •
• I. J•
11
•:
• i I
•
••
0-
50
40
0) 30
E
0_ 20
10
--_{._ I._.-.......
300
O — 250
Q - 200
O E
_ ; 150
0
100
50
0
• '
1.
1
r-1 F
•
•
•
•
•_I
•.
LI
•
a
•
-1"-
• tI
-222
-7
I
••
• •
1
•
•
1;
•
L
•a
•
••
•
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
SUMMARY OF WATER QUALITY AT CWW-2
RENEWAL OF INJECTION WELL PERMIT
TANK FARM REMEDIAL ACTION PLAN
PCS PHOSPHATE COMPANY
AURORA, NORTH CAROLINA
oSAWN BY: KSP
f•E No.:
02+051
ammo]/02
�1'pY1 Imo. oPE:9/120
Dear: 20

•
8
7
4
W
0
3.500
• 3,000
E
ZN 2,500
O O
U E 2.000
it a 1.s00
0
0
W
0
W
• 2.000
CD J • E 1.s00
o O o
Q �I1.o03
0
600
1,000
a E
J
c
(n 1 0)
TOTAL PHOSPHORUS
2,500
I
•
T7
•
1 •
•
II
i
••
}_
II
•
•
F.
•
•
H
II
f74
•'-
1
P •
1
1 i
•
1
+-
1
•is
1
LI
•
1
•1
1
r
I.
•
I
•
, •
I
••
I_i
•
• a 7 •
-••
IT I
1.000
750
500
250
•
50
▪ 30
E
d 20
10
1.-
L_L
---r-'-
I
E •
•
•
300
o— u3
Q �O 200
O E
U U
150
100
s0
0
1_1
r'r
I i i
1
111
o
1
•
;0.
•
•
T
0
•
t
•
1992
1993
1994
}
1995
1996
I
1997
1998
—i-i:{---
1999
2000
IJ
2001
2002
SUMMARY OF WATER QUALITY AT CWW-3
RENEWAL OF INJECTION WELL PERMIT
TANK FARM REMEDIAL ACTION PLAN
PCS PHOSPHATE COMPANY
AURORA, NORTH CAROLINA
o033333Pill (WOE. 09/17/02
^ -)i-) "rum` 21
CRAM BY: KSP
RENO.:
02-051

TOTAL DISSOLVED
O
W =
u_ a
6
7
6
5
4
•
1• I
•
•
i•
•
• L
•
•
/•
1i -
� * j
H
• • I. 1
•
r
1_..
0
Q 3,500
3,000
E
ZN 2,500
O o
O E 2.000
LT_ a 1,500
w
a_
1n
1,000
2.500
DE
j v 1,500
O 0
co
- 1,000
500
I
i—
F 1 1
1
• i • •
I
}
• '•i
• •
I
• -1
•
•
•
r
•
• •
I t
L
1-
•
•ry
i
•
• r •.•_
I
•
W
I - co 150
Q E
500
- 1n rn
250
0
•
I -
50
90
30
20
10
1.
I.•-. •-•-_'•
I
r
•
I 1
•-
•
LL
L.
300
250
200
150
100
50
0
-4
1992
•1
•
1993
••
I
1994
••
1995
1996
�i• IWOSC
1997
1998
•
G
1909
2000
2001
2002
SUMMARY OF WATER QUALITY AT CWW-4
RENEWAL OF INJECTION WELL PERMIT
TANK FARM REMEDIAL ACTION PLAN
PCS PHOSPHATE COMPANY
AURORA, NORTH '" CAROLINA
DRAWN BY: KSP a€a0'n:/'rJ' 1I¢112 09/17/02
02-051 ►_

8
7
4
I•.
•
•
•
•
•
I'rj
I
•
L.
L
i
L L
IiI
w
U
O 3,500
1.
0 3,000
D
ZN 2.500
O o
U E 2,000
LT. 3 1,500
0
a
co
0
2,000
E
2 0
_ j 1,500
❑ O 2, 1,000
0
1, 0
�.1
2,500
500
I 1 I
{
i I
H
•
•
a L..
I I
�T-
1
I
l {±
•
0
L._`.....1
_4
••
•
7-
1 •
4 -I
•0
•
0-
0_
•
•
1--1
•
•
I•
TL
• • •
-
1,000
1- rn 750
J E
V 500
�_O
TOTAL PHOSPHORUS
EE
a
I
.r''i.
I
• 7 •
•.
0-
0
250
50
40
30
20
10
0
i_
1 I
_
+
•
•
-
I
r
: ;--•
�..,
•
;-
I ' ;
--,-t---
rt 1
ITII-1-
_�_.
.�._
._-._._
i
r ._.__
T
1 i
I
{'
1
300
w 250
O E 200
.J = 150
U
C.)
100
50
0
_...a
{
{
1
f
}
_..I a-
,--.
.....
1
a
•
I
1 tt
Jr-
1-4 1
1I-:
1992
1993
1994
1995
_4
1996
1997
1998
1999
2000
2001
2002
SUMMARY OF WATER QUALITY AT CWW-5
RENEWAL OF INJECTION WELL PERMIT
TANI< FARM REMEDIAL ACTION PLAN
PCS PHOSPHATE COMPANY
AURORA, NORTH CAROLINA
DRAWN BY: KSP C000 BY:
.E 00.1
02-051
IoAlt 09/17/02
FIGURE: 23

8
7
❑
w a 6
5
w 4
0
Lrt
3.000
D
❑ V 2,500
O o
U E 2,000
LU3 1,500
U
0_ 1•
co
❑ 2500
w
OJ 0)c 2,000
CQ ❑ E
O U to 1,500
I- 1, 0 0
0
I
4
•
1
•
•
•
r
•
•
1
_1....-1.._;
Ih_
I I 1
rr
•
•
•_ ..... .
I•_•
I
•-
r
•
•
• I •
•
•1
•
•
rt
•-i
3.500
500
1,000
H750
_1 UEI
500
- n—b(
to
250
TOTAL PHOSPHORUS
0
• • _
1I
•
r
ill
•
•
•: • •
J
• • 0 •
•
•
•
L
5o
4o
�p 30
d 20
10
r
•_s
•
Arint•--
•
i-
• • s
•
•
• im
•
••
300
100
50
0
I
i
1
1
•
•
• • • •
•!._•..
••I.1-
_1
• ••
•0
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
SUMMARY OF WATER QUALITY AT CWW-6
RENEWAL OF INJECTION WELL PERMIT
TANK FARM REMEDIAL ACTION PLAN
PCS PHOSPHATE COMPANY
AURORA, NORTH CAROLINA
DRAWN BY: KSP
FIE N0.:
02.051
lams. 09/17/02
F1GUPE:

8
7
w • = 8
u_ a
5
4
0
• 3,500
0 9,000
Z- 2.500
O o
U E 2.000
ll 3 1,500
W 1,000
n.
W
W
J
0 CO
❑ O
J w
H
0
• 1 • ; i
r
•
•
I ••
• • i
•
•
i_
H
J_
H
1-11u
1
I 1
LL
2,500
I I
_
r
_..._
2,000
— 1,500
cn
~ 1.000
500
s
•••
•_I
•
•
II
1-
1'
•
•
1itt
•
i•
•• • »J
L_t
rr-:
•
!I
1_r
•
I- �
E
J 500
-0—
co N
TOTAL PHOSPHORUS
01
E
0
250
50
40
30
20
10
300
100
so
0
0
y
I
is.
1
'
• •a
rt
_
_I -1
11 :
- 1
_
1 I-
I
-t-
I
{
IH±
I_4
f
•
_ _ •
•
f I
L i-
I
0
1 _•
•
F
1
L.
•
I 1
{
1 _
I
•-t
iIL.
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
SUMMARY OF WATER QUALITY AT CWW-7
FLE :
02-051
RENEWAL OF INJECTION WELL PERMIT
TANK FARM REMEDIAL ACTION PLAN
PCS PHOSPHATE COMPANY
AURORA, NORTH CAROLINA
DRUM BY: KSP I CHECKED }] TM I DAIL 09/17/02
wit FIGURE: 25

CADD FILE T:\CORPORATE\02\02-051\02051-26.DWG DATE: 08/28/02 REVISED BY: BTW
CPA
-n
(n
m
m
C
N
CPZ-1
3900
0
CPZ-2 2420'
CWW-2
�2100
TOTAL DISSOLVED
SOLIDS IN mg/I•
—
-JDo �.
CIW-2
S
LIMITS OF
TANK FARM -,
IW-4 C
4831 M 488 1C -CIW-8
00 00 0 ID.e• C480'
000
0
CW W-T
u
T+1 x1L3
12.1
0
17.6
INJECTION WATER
8.6
TDS CONCENTRATION
1 I .le.e 11 I I—
APRIL 2002 CROATAN FORMATION GENERALIZED TOTAL
DISSOLVED SOLIDS CONCENTRATION CONTOURS
12.9
0
76
150
SCALE: — 1'-150'
LEGEND
O PIEZOMETER
O MONITOR WELL
Q WITHDRAWAL WELL
• INJECTION WELL

L
CADD FILE T:\CORPORATE\02\02-05 \02051-27.DW0 DATE 08/28/02 REVISED BY: B1W
CPZ-1
1888
CWW-2 CWW-3
718 784 631
114141000
"112 SPILL LOCATION
9CIW-3
L
u
WW-4 CWW-6
854 46p
SO4 CONCENTRATION
INI mg/I
II I "1z.2 I I
rrn
12.1
CWW-7
218 r-i
C7
17.6
8.6
INJECTION WATER
304 CONCENTRATION
APRIL 2002ICROATAN FORMATION GENERALIZED
SULFATE CONCENTRATION CONTOURS
0 76 150
MS
SCALE—1"•150'
LEGEND
0 PIEZOMETER
C MONITOR WELL
Q WITHDRAWAL WELL
INJECTION WELL
OUTFALL
CANAL
12.9
r1

1
1
Attachment I
Figures from October 31, 1989 Supplemental Remedial Action Plan
Figure
Title
1-1
Tank Farm Site Plan
2-3
Generalized Subsurface Stratigraphy
2-4
Water Table Elevation in Surficial Sand Layer
2-5
Potentiometric Surface Map for Confined Sand Layer
2-6
Potentiometric Surface Map for Croatan Formation
3-1
Groundwater Quality in Surficial Sand Layer
3-2
Groundwater Quality in Confined Sand Layer
3-3
Groundwater Quality in Croatan Formation
4-2
Schematic Cross Section of Cut-0ff Wall and
Dewatering Well Containment System

If
•15
E:Ar:s.111 s1.11),
------, ..... .----------
MONITOR WELL. " •••"
...... ----CLUSTER MWTF-2C-•
\
(/—) not Sut.Fort
1 TA11K 1 1
1
1
MONITOR WELL
" • ... " ----• - . .
%'\ / / STAGE 1 WELL -POINT
r \\
i $111-FIE I j sulkun I DEWATERING SYSTEM
• • 1 • -Toix 71 TAim a 7 (OPERATED FROM
.,,
\‘ 07/12/88 THROUGH
1 c TANK 008 re— —
--(LEAK INCIDgRT —
REPORTED 05/310M)
\se
(0,1\1 I
) 1
001a-
. LI
- ; I
SPA 1
1 SPA 1
1 MAW I
I 1 i 5- ANT f
LOCATION OIUNDERGROUND - 1- • ---1:1
1 6/
DRAIN LINE LEAK INCIDENT li ,
(LEAK INCIDENT REPORTED 06/05/89
100 200
SCALE 1-150
/Th.
(/11107) ( 019 )
\ • i
STAGE SWELL -POINT
DEWATERING SYSTEM
(OPERATED FROM 09/13/88
THROUGH 11/01188); riAck
/s1 (1,PICAL;
-MONITOR WELL
CLUSTER MWTF-1
rip r:.,• (-) )
[ : • ... '''' ''''
f icy!)
1 '
-0,0. •
TANK FARM SITE PLAN
0
art Ardaman & Associates, Inc.
Consulting Enginnrs in Soil Median's;
Foundations. and Materials Tasting
•.;.••••,,:r4••
SUPPLEMENTAL REMEDIAL ACTION PLAN
TANK FARM AREA
TEXASGULF INC.
PHOSPHATE OPERATIONS
AURORA, NORTH CAROUNA
N24568
FIGURE 1-1
DPA
IY: RBE
ILE NO.
88-089
OlICRED BY: F 9/22/139
IY:

a
MWon•1 � *1 MH!TFJ
, r rw.�ivw:.xswn —t
•
'WPTF-1
i
SCALE -.IT.
Oji J ® Ji
•
�•NWTT.1
KEY MAP

AC-4t SUP
1"--*
Its.1110
I yrk '11.01-P
I
MWTF 2A ,
"
MWTF-3A
7 N
i 0
7 ( "1 ) I StILHISI 74
" '1.'1R \ l' SII.A.POSI ;
N....._/: k TANS I -lb.. 1 ,%"ts,, I 1
\ :ASA S 7
1§ /te
,,, ''.?
\ i I
- .,..., _,,,,,, , , ,„ s
I I
Ctir
s I
SPA
I PI AUL ,
L—
!, I
100 200
SCALE 111-150'
SSA
P1 i1
"I' MWTF-1A
EL 9.44'
F .
L. WATER TABLE ELEVATION .2 -
IN FEET AMSL) IS MEASURED 4,7:22
IN APRIL 19BBig(C19 (C.“;)
WATER TABLE ELEVATION IN
SURFICIAL SAND LAYER
OtS
1
‘2, i
11
CUPICALI
eery! Ardaman & Associates Inc.
22,
Consulting Engineers in Soil Mechanics.
Foundations. and Matariels Testing
SUPPLEMENTAL REMEDIAL ACTION PLAN
TANK FARM AREA
TEXASGULF INC.
PHOSPHATE OPERATIONS
AURORA, NORTH CAROUNA
N24568
FIGURE 2-4
OMII BY:
FILE Na
88-089

NAR[E OUP
MWTF 28
E1...A.66.1.-L-ei2_.'.
Er ( \ SULFURN
us
�� TANK 1
\ j
F
irallib
'EQi'i.i2['a
I t
MWTF-36
EL' 3.67{-
PR
4.0,
1 `iUl ON
TANK 3
1 ,cs 1! t, ; o jn< „ i rt:: 1 (•,'r 1 O
om
I_ ib..1
3PA j
j PLANT
MWTF-1 B
i L--. �. � EL 8.66'
It rii.0 i
: i Ci �j
ry.. —1 _.. ...�.. ._.
i
100 200
SCALE 1°-150'
I
{ozo (o20
1' (Ot�.
o21
01s
0
i�.
POTENTIOMETRIC SURFACE MAP
FOR CONFINED _SAND LAYER
— PIP_ PACK
(TYPICAL)
PIEZOMETRIC WATER
ELEVATION IN FEET (MSL)
IN APRIL 1989
®� Ardaman & Associates, Inc.
Consulting Engineers In Soil Myth .la,
.,'t,» ✓, by Foundations, and Materials Toting
SUPPLEMENTAL REMEDIAL ACTION PLAN
TANK FARM AREA
TEXASOULF INC.
PHOSPHATE OPERATIONS
AURORA, NORTH CAROLINA
RA YM v:
ABE IOW
one 11 ern: 8/22/a9
N2A568
FIGURE 2-5
'ILI PIO.
88-088

9AHSE SLIP
.. MWT.F....2C.. _
1 �
( pm � so ;curt s
l % 1 TAM 1 )
II
_..I
o9
11-. II- o0
cy r�
fot•
yI (x0 {;ux •an,; -RY 1 ot:; t o
t 'I SPA 1 t....-"
1 1 1 PLANT , SPA i
1 r FlSNI' i
PIEZOMETRIC WATER t / i-...-.--
ELEVATION IN FEET (MSL)+ �*1 ' I-•"'
IN JULY 11989 p �� j(.1 MWTF-1C
It 1 r .. I j_ ..._.` iS EL.-2,19'
MWTF-SC
f
j c;,,T � SUtit tin
iANK2 ) TANKS
0 100 200
SCALE 1"-150'
c1�
/ 1
ra! i
POTENTIOMETRIC SURFACE MAP
FOR CROATAN FORMATION
PIPE HACK
(TYPICAL)
- airy Ardaman & Associates, Inc.
Consulting Enginrn In Soil MadunILa,
Foundations, and Materials Testing
SUPPLEMENTAL REMEDIAL ACTION PLAN
TANK FARM AREA
TEXASOULF INC.
PHOSPHATE OPERATIONS
AURORA, NORTH CAROIJNA
DRAM" BY: RBE Ieaeum IT: 15
1 laAYt 9/22/B9
f ILI NO. Ma0V1 Yt
8S-089.�,�
N24668
FIGURE 2-6

0APOS SLIP
pH • = 6.4
P - 0.15
F=0.18 ,,
SO4=306
TDS 5'973 t IAA run
TOC= 1I MAK I
........WPTF-1A�
pH=°6.*•....�
P = 87..0
!j F=0.23 _
SO4 = 1,862', •
Co?) \ (TDs:=r35_oa' ( \
`✓ \TOO =;12;'f '
SO.;= 98
sitTOS '>F 796'i s:,,m
TOC 8.3 TMO( 3
(OPT i 0i911'
0i.�
I o34 )
SPA I
PLA'ST
S MWTF-1A
6.8
. .. a........; P = 0.40
F=0.71
i i .,. SO4 = 74
I TOR i 325 (c„
t. I i TOC ............... `..
dos,)
Ot
......... PIPE PACK
(TYPICAL)
GROUNDWATER QUALITY IN SURFICIAL SAND LAYER
100 200
SCALE 1"-150'
EMT7 Ardaman & Associates, Inc.
to .ultinr EnVrr=n In Sou M.n.Ia,
Foundations. and Mamlalt Tatino
SUPPLEMENTAL REMEDIAL ACTION PLAN
TANK FARM AREA
TEKASOULF INC.
PHOSPHATE OPERATIONS
AURORA, NORTH CAROUNA
CONCENTRATIONS IN mg/I
N2A668
FIflURF. 3.1

11
tAr1fiE 81.111
MWTF-2E092
• pH 6.4
P es.62
S0.41. on- /
TDS r1497. t Su&Jtj
TOCr 9.7 -taw
1
lJ
<1 u
4— _I
.... _•-., -.• •-.. ,.•
s MW17-3B
7 SC144 512).
IDS IF 154iF
SULFUR
I • IAN1T9C " TANK 3
pH 6:1
P =34:5".;
I SO te7'
) 11'1' trCIS .71= TM 1 ( cr,
I 1:Pql= ‘N 2
i I
SPA
PLANT /
1 •
..... ...-5
0,7) ot9 t
Nn
.... —)
051
MWTF-16
pH = 5.6
P = 0.19
F = 0.27
. SO4 = 17
I (1;:) IDS rd." (02.0
r-, t • IOC •--1
Lir\ loie;\ to) 612) (of-)
015
0
„ .......... PIPE PACK
(TYPICAL}
GROUNDWATER QUALITY IN CONFINED SAND LAYER
100 200
SCALE — 1"-150
CONCENTRATIONS IN mg/I
Ardaman & Associates, Inc.
no%Consulting Engineers In Soil Mechanics,
Foundations. end Materials Testing
SUPPLEMENTAL REMEDIAL ACTION PLAN
TANK FARM AREA
TECASGULF INC.
PHOSPHATE OPERATIONS
AURORA, NORTH CAROUNA
N24568
FIGURE 3-2
onA
111.1 NO.
88-089.

• .S
1
11
ti r(.117.:t
P = 15.6 _
F = 0.17 / \
SO, = an. ,
TDS =123311 skLy or;
TOG = 13 I TANK i 1
ato,
r•IttAl
P = 34.3-g
F = 0.37
SO„ ''"
727:,
IDS. = /1084i
/"•
SPA
;41.Actl'
! '
11 I
II M1NTF-1C
pR = 6.9
F = 0.38
!IDS
1:1,1)
•
P = 342/.
.,•
Sej = 6472,/
,stp JOS I= 2003:-• stmckin
I IOC 104
TANK 1
1.- 4
Ct7j Cos )
i6 saELY23,.s1
.1
GROUNDWATER QUALITY IN CROATAN FORMATION
100 200
SCALE — 1-150
CONCENTRATIONS IN mg/I
war is Ardaman & Associates, Inc.
Consulting Engineers in Soil Machanka.
Foundations. and Mandell Tatting
SUPPLEMENTAL REMEDIAL ACTION PLAN
TANK FARM AREA
TEXASGULF INC.
PHOSPHATE OPERATIONS
AURORA, NORTH CAROIJNA
"A RBE /DIECICIDOWIPA IOAM 9/22/89
F88-089 Anson Fat MO.
rifle irg=

rtl
I
0
-10
-20
-30
Z
0
H -40
J
W -S0
DRAWN IT:
!M Ardaman & Associates, Inc.
G.driw EE j..n i. Sfl, NttMM_,,
F.SBui., .. I t.Su Tat*
SUPPLEMENTAL REMEDIAL ACTION PLAN
TANK FARM AREA
TEXASGULf INC.
PHOSPHATE OPERATIONS
AURORA, NORTH CAROLINA
RBE lamaose: 'DATE: 9/22/89
N24561
FILE NO.
88-088
FIGURE 4-2

Z
O
UL
0
-10
-20
-30
-40
-50
SOIL-BENTONITE
CUT-OFF WALL
PAMUCO RIVER
BARGE SUP
DEWATERING WELLS
DRAINAGE DITCH
SULFUR TANKS
FINE SAND TO'CIAYEF FINE SANG
CLAYEY FINE SAND TO
SANDY PLASTIC CLAY
PHOSPHORIC
ACID TANKS
CLAYEY FINE SAND TO PLASTIC CLAY
WITH SOME SHELL FRAGMENTS /
1
0 100
HORIZONTAL DISTANCE
200
300
400
500
600
SCHEMATIC CROSS SECTION OF CUT-OFF WALL
AND DEWATERING WELL CONTAINMENT SYSTEM
700
FEET
I♦� Ardaman & Associates, Inc.
wispyGsoIDN Equsn I SIU, HT*r.pdgy,
Foundation, e1 A1EtFrib Tat*
SUPPLEMENTAL REMEDIAL ACTION PLAN
TANK FARM AREA
TE%ASOULF INC.
PHOSPHATE OPERATIONS
AURORA, NORTH CAROLINA
N24568
DN.MNEv: RBE lammo ''1 IDArE: 9/22189
FILE NO.
88489
.V,N
FIGURE 4-2