December 1986      EPA-700 8-87'
    Hazardous Waste Ground-Water
             Task Force
 Evaluation of IT CORPORATION Facility
      Imperial Valley, California
        xvEPA
    US Environmental Protection Agency

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                                                                  December 1986
                                       UPDATE
                         GROUND WATER TASK FORCE EVALUATION
                             IT IMPERIAL (WESTMORLAND)


     The United States Environmental Protection Agency's Hazardous Waste Ground
Water Task Force (Task Force), in conjunction with the State of California Depart-
ment of Health Services, State Water Resources Control Board, and Regional Water
Quality Control Board recently completed an evaluation of the ground water monitor-
ing program at the IT Imperial disposal facility near Westmorland, California.
The purpose of the investigation was to determine if the facility was in compliance
with applicable RCRA ground water monitoring requirements in the area of its surface
impoundments.

     IT Imperial is one of 58 facilities nationally which are being evaluated by
the Task Force.

     The evaluation concludes that the ground water monitoring program in the area
of the facility's surface impoundments is inadequate.  Specifically,

(1)  IT has not characterized the site hydrogeology sufficiently to establish a
     ground water monitoring system capable of detecting contaminant migration fron
     the surface impoundments,

(2)  Existing monitoring wells are located too far away from the surface impound-
     ments to be able to immediately detect leakage from the impoundments, and

(3)  The wells are not correctly designed arid constructed based on site-specific
     hydrogeologic conditions, resulting in routinely turbid and otherwise
     unrepresentative samples.

     Ground water samples were obtained during this investigation and IT's interim
status period monitoring data was reviewed to assess the quality of ground water
in the area of the surface impoundments.  However, given the deficiencies in the
monitoring program itself, the usefulness of the water quality data as an indication
of ground water contamination is seriously ccmprcmised.

     Although IT has performed some additional field work in the area of Pond 9,
IT has not provided additional hydrogeologic information to EPA since its July,
1986 site characterization report was submitted to EPA.  Therefore, EPA will, in
all likelihood, take enforcement action ordering IT to undertake the following
activities:

(1)  provide additional site characterization information to clearly-identify
     aquifer systems, and perform additional field work, as necessary, to fill
     data gaps,

(2)  install new monitoring wells,

(3)  revise sampling procedures,

(4)  sample new monitoring wells on an accelerated schedule and analyze for an
     expanded list of parameters and

(5)  perform a statistical evaluation of analytical data to determine if operation
     of the surface impoundments is affecting ground water quality.

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December 1986                       EPA-700 8-87-006
              HAZARDOUS WASTE GROUND-WATER
                       TASK FORCE
         Evaluation of IT CORPORATION Facility

              Imperial Valley, California
          U.S. Environmental Protection Agency

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 U.  S.  Environmental Protection Agency
              Region 9
  National Ground Water Task Force
            IT IMPERIAL

GROUND WATER MONITORING SYSTEM EVALUATION
           Kenneth Yelsey

           November, 1986

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                     Table of Contents
I. Executive Summary

   A. Introduction                                         1
   B. Objectives                                           1
   C. Reporting Format                                     2
   D. Task Force Participants/Roles                        3
   E. Summary of Findings                                  3
II. Data Review

   A. Site Description                                     5
   B. Waste Management Operations                          6
   C. Ground Water Monitoring System                       7
      1. Chronology of Well Installation                   7
      2. Monitoring Wells                                  8
      3. Chronology of Selected Ground Water Related       9
         Notices, Submittals, and Inspections
   D. Hydrogeology                                        10
      1. Site Geology                                     10
      2. Site Hydrogeology                                11
      3. Data Inconsistencies                             13
   E. Vadose Zone and Contaminant Migration               14
   F. Well Evaluation                                     16
      1. Well Ldcation                                    16
      2. Drilling and Development                         16
      3. Screen Specifications                            17
      4. Filter Pack, Sealant, and Casing Material        17
      5. Screen Placement                                 18
      6. Water Elevations, Water Quality, and             18
         Statistical Determinations
      7. Well Construction Details and Well               20
         Completion (Table 1)
      8. Well Information (Table 2)                       21
      9. Well Design (Table 3)                            22
     10. Conclusions                                      23
     11. Recommendations                                  23
   G. Analytical Resuults                                 24
   H. Facility Laboratory Analysis                        24
   I. Compliance with Ground Water Monitoring             25
   J. Summary of Recommendations and Concluding           25
      Remarks

      References                                          26
      Figures

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                      I.  EXECUTIVE SUMMARY
A. Introduction

     The Environmental Protection Agency (EPA) established a
Hazardous Waste Ground Water Task Force (Task Force) to evaluate
compliance with Resource Conservation and Recovery Act (RCRA)
ground water monitoring requirements at selected facilities
nationwide.  The Task Force comprises personnel from EPA Head-
quarters, EPA Regional Offices, and State Offices.  The following
report summarizes the Task Force investigation of January, 1986,
at the International Technology (IT) Corporation Imperial Valley
facility located near the town of Westmorland, California.

B. Objectives

     The objectives of the investigation were to determine compli-
ance with the following:

1)   Ground water monitoring requirements of 40 C.F.R. Part 265,
     Subpart F; and

2)   Ground water monitoring information requirements of 40 C.F.R.
     Part 270.14(c) of the RCRA Part B permit application.

     The Task Force investigation focused on the RCRA regulated
waste management units (i.e., the surface impoundments as opposed
to the recently constructed landfill) and included evaluations of
the following:

     a)  Site hydrogeology;

     b)  Monitoring well location,  construction, and design;

     c)  Sampling and analysis plans;

     d)  Ground water sampling procedures;  and

     e)  On-site and off-site facility analytical laboratories.

     To accomplish the objectives of the Task Force study, the
investigation was divided into three (3) phases;

1)   Sample Collection and Audit,

2)   Laboratory Audit, and

3)   Data Review.

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                               -2-
     The sample collection and audit phase consisted of EPA
directed sampling of selected facility wells and auditing of
facility sampling procedures.  The laboratory audit phase in-
cluded an evaluation of the facility's on-site laboratory and
off-site laboratories  (Martinez, CA and Pittsburgh, PA) for
analytical integrity and waste analysis protocol.  The data
review phase of the investigation consisted of evaluating infor-
mation submitted by the facility regarding the design and
operation of the ground water monitoring system  (e.g., ground
water quality data, hydrogeological reports, monitoring well
design information, etc.).

C. Reporting Format

     The results of the Task Force study are contained in seven
(7) reports which are  listed below and grouped according to the
appropriate phase of investigation.  Included is the name of the
report's preparer along with a brief description of the report's
content.

Phase I - Sample Collection and Audit

     1.  Sample Audit  by Peter Rubenstein - Evaluation of facility
         sampling procedures and plans.

     2.  Sample Collection by Kenneth Yelsey - Documentation of
         Task Force ground water sampling procedures.

Phase II - Laboratory  Audit  (facility)

     3.  Pittsburgh, PA Laboratory Audit by Kevin Wong - Audit
         of ground water analytical laboratory.

     4.  Martinez, CA  Laboratory Audit by Kevin Wong - Audit of
         off-site waste identification laboratory.

     5.  Imperial Laboratory Audit by Kevin Wong - Audit of on-
         site waste identification laboratory.

     6.  Ground Water  Data Evaluation by Kevin Wong - Validation
         of Task Force ground water sample analyses and sample
         data review.

Phase III - Data Review

     7.  Ground Water  Monitoring System Evaluation by Kenneth
         Yelsey - Review of  system adequacy.

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                               -3-


D. Task Force Participants/Roles

         Ken Yelsey - EPA Region IX/Project Leader

         Don Shosky - EPA Region VHI/Core Team representative

         Peter Rubenstein - EPA Region IX/Auditor of facility
                            sampling procedures

         Kevin Wong - EPA Region IX/Auditor of on-site and off-site
                      facility laboratories

         Darcy Higgins, John Hatcher, and Alicia Felitas - Versar,
         Inc./Sample Team members

     The State of California concurrently conducted a Comprehensive
Monitoring Evaluation (CME) of the site.  Participants included
John Anderson of the Regional Water Quality Control Board (Colorado
River Basin region) and Chuck Stultz of the Department of Health
Services (Los Angeles office).  Other representatives of the
State Water Resources Board, Department of Health Services, and
EPA were present on-site during the field investigation.  Con-
comitant activities during the field phase included a(n) RCRA
inspection, Preliminary Assessment/Site Investigation (PA/SI),
and overview of on-going landfill construction activities.


E. Summary of Findings (listed by report number)

1.  The facility followed the sampling procedures described in
the sample plan.  Some deficiencies were noted with sample
collection and preservation.

2.  The Task Force followed the sample collection protocol des-
cribed in the Project Plan.

3.  The Pittsburgh, PA analytical laboratory's protocol for ground
water analyses was adequate.

4.  The Martinez, CA analytical laboratory's protocol for pre-
disposal waste identification was generally adequate.  Some
deficiencies were noted though the review was limited.

5.  The IT Imperial laboratory's protocol for waste screening was
adequate given the current level of facility operations.

6.  Task Force water quality data was validated for quality
assurance.   Analytical results detected four (4) volatile organic
constituents (i.e., methylene chloride, acetone, chloroform/ and
carbon tetrachloride)  and one (1) extractable organic (bis 2-

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                          -4-
ethylhexyl).  The volatile organics were detected in blank
samples (i.e., equipment or performance evaluation)  indicat-
ing laboratory and/or field contamination.  Note that"chloroform
and carbon tetrachloride were detected in a facility blank sample
indicating test water or sampling equipment contamination.  The
e-xtractable organic compound was detected in well 17.  The
source of bis 2-ethylhexyl (a plasticizer) is unknown.   The
facility must investigate the source of this compound.   A rela-
tively high value (i.e., compared to other positive analyses) of
the indicator parameter TOC was detected in well 6A suggesting
the probable presence of unidentifiable organic compounds.  Inor-
ganic constituents were detected in the ground water.  Concentra-
tions varied within normal ranges.

7.  IT Imperial's ground water monitoring system for the surface
impoundments is inadequate.  Deficiencies were noted with site
characterization and well location and design.  A new detection
monitoring system is needed.

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                               -5-
                       II.  DATA REVIEW


A. Site Description

     The IT Imperial facility is located in Imperial County,
California.  The facility  is sited approximately  four  (4) miles
south of the Salton Sea and six (6) miles west of the  town of
Westmorland.  The IT facility is accessed by South Garvey Road
and State Highway 86 (Figures 1 and 2).

     The climate of the region  is arid, characterized  by hot, dry
summers and mild winters.   Precipitation averages less than five
(5) inches annually.  Evaporation rates average seventy-two to
eighty-four inches annually.

     The site is relatively flat, gently sloping  in a  northeast
direction (Figure 3).  Elevations at the site range from thirty-
seven feet below mean sea level to one hundred twenty-three feet
below mean sea level.  The site occupies six hundred forty acres.
The hazardous waste management units cover twenty acres.  The
site is dissected by several washes which trend in a northeast
direction.  Surface water flow is ephemeral in the washes.  The
site is bordered on all sides by publicly owned and BLM managed
land.  There are no drinking water supply wells in the area.  The
Westside Main Canal and the Trifolium Drainage Canal lie one-half
(1/2) mile northeast of the site (Figure 3).

     The IT Imperial facility is located in the physiographic
province known as the Salton Trough.   The Salton Trough is a
geological structural feature encompassing the Salton  Sea and
Imperial Valley.   The trough is associated with a regional rift
zone and is fault-bounded with mountain ranges bordering along
the east and west.

     Imperial Valley is a northwest-trending alluvial basin.
The valley is comprised of Cenozoic sediments of marine and non-
marine origin.  It is a seismically active region.  Numerous faults
lie within fifteen miles of the site (e.g., Superstition Hills,
Imperial, Brawley,  Coyote Creek, and Superstition Mountain faults).
See Figure 1.  The facility is located on Quaternary age lacustrine
deposits.  The sediments consist of partially indurated clays,
silts, and sands.  Some alluvium consisting of silty sands lies at
the surface and near surface.

     IT has been conducting an extensive site hydrogeological
characterization of the site at the request of the regulatory
agencies.  Activities have included the drilling of explora-
tory boreholes, installation of piezometers and monitoring wells,

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                               -6-


trenching, and sampling/testing of subsurface materials (i.e.,
dry densities, sieve analyses, Atterberg limits, and lab permeabil-
ities).  Work commenced in August, 1985, and was continuing at
the time of writing of this report.  IT had previously conducted a
number of geotechnical investigations which had focused on specific
waste management units.

B. Waste Management Operations

     IT Corporation operates a Class II-I waste disposal site.
The facility was issued a site permit in November, 1980, by the
California Department of Health Services.  The facility operates
four (4) RCRA regulated surface impoundments (Figure 4).  Wastes
were first received in 1981.  Two (2) partially constructed ponds
(numbers 4 and 6) located adjacent to the RCRA regulated ponds
have never been used for waste disposal.  The facility also
operates a container storage area (i.e., Baker tanks) located at
the south edge of pond 9.

     Three (3) non-RCRA waste management units (i.e., two ponds
and a solids disposal site) located in the northeastern section
of the site were utilized for geothermal waste disposal from 1981
until 1985.  The facility has recently constructed a RCRA landfill
at the former site of the ponds (Figure 4).  The facility also
intends to build an industrial waste treatment plant.

     The following is a listing of the wastes managed by the
facility.  The list, including corresponding alpha-numeric desig-
nations, refers to RCRA identification criteria.

Characteristic Wastes (ignitablity, corrosivity, and reactivity)
(D001 - D003)

Characteristic Wastes (EP toxicity)
(D004 - D011)

Petroleum Refining Wastes
(K048 - K051)

Spent Non-Halogenated Solvents
(F003 - F005)

Electroplating Wastewater Treatment Sludges
(F006)

Spent Pickle Liquor from Steel Finishing Operations
(K062)

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                               -7-
The following table summarizes waste disposal  activities  at  the
site as reported in the August, 1985, Part B application.
Approx.
Quantity
of RCRA
Wastes
Disposed
( tons)
6,552
6,552
2,309
6,188



Surface
Impoundment
Number
8
5
3
9



Commencement
of RCRA Waste
Disposal
12/26/1980
03/07/1981
02/06/1981
01/20/1984




Waste
Types
F006, D004-D011
F006, D004-D011
F006, D004-D011
F003, F005, K048
K049, K050, K051
Major waste types received at the facility  include  K051  for  pond
9 and waste D007 for ponds 5 and 8.  Note that wastes D001 - D003
and K062 are not listed.

The following table contains surface impoundment design  information,

     Surface
Impoundment
Number
3
5
8
9
Unit
Acreage
5.5
3.5
4.3
8.5
Design Volume
(gallons )
5,000,000
5,000,000
7,000,000
3,000,000
Depth
5
8
8
3
(feet)




The surface impoundments were constructed using native materials

C. Ground Water Monitoring System

           1. Chronology of Well Installation


January, 1981          - Wells 5, 6, 7, and 13

June, 1983             - Wells 8A, 8B, 8C, 9A, 9B, and 9C

August, 1983           - Wells 10B, 11B, 12,B, 14B, and 15B

March, 1985            - Wells 5, 6, 7, and 13 abandoned and
                         plugged (screened sections transected
                         two water-bearing zones)

January - April, 1985  - Wells 5A, 6A, 7A, 13A, 16, 17, and 18

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                               -8-
               2. Monitoring Wells (see Table 2)


Shallow aquifer wells  - 6A, 7A, 8B,  9B, 10B, 11B, 12B, 14B, 15B,

                         16, 17

Deep aquifer wells     - *5A, 8C, 9C, 13A, 18

     * denotes background well

Additional Notes:

     1)  Well classifications (i.e.,  shallow or deep) are based
         upon facility designations.

     2)  Wells 8A and 9A are dry.

     3)  Sixteen wells were identified in the August, 1985, and
         July, 1986, Part B submittals as RCRA ground water
         monitoring wells (Figure 5).  Nine  (9) of the wells were
         identified in the August, 1985, submittal as monitoring
         the surface impoundments and included the following:

                                 5A        8B
                                 ISA       8C
                                 18        9B
                                 6A        9C
                                 7A

         The remaining seven (7) wells were  installed to monitor
         ponds 1 and 2 and the  Solids Disposal Area  (per the
         August, 1985, Part B)  formerly located in the north-
         eastern corner of the  site.  These  wells were not eval-
         uated as part of this  review although samples were
         obtained from wells 10B, 12B,  15B,  and 17.  It should
         be noted that the facility has installed ten new wells
         around  the recently constructed landfill.

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                              -9-


         Chronology  of  Selected  Ground Water  Related  Notices,
                  Submittals,  and  Inspections


 November 11, 1980 - California  Department of Health  Services  (DOHS)
    issues hazardous waste  permit.

 April  29,  1981 - California Regional Water Quality Control  Board
    issues Waste Discharge  Requirement Order.

 March  27,  1984 - EPA conducts ground water inspection.

 August 20, 1984 - IT submits  Part B.

 May 1985  - IT submits  Proposed  Ground Water  Monitoring Program
   Technical Report

 June 20,  1985 - EPA issues Notice of Deficiency  (NOD).

 June,  1985 - IT submits As-Built Geologic Report, Landfill
   Construction.

August 13, 1985 - IT submits site characterization proposal.

 January,  1986 - Task Force and  State conduct ground  water
   inspections.

January, 1986 - IT submits Hydrogeologic Data Report for
   landfill.

March,  1986 - IT submits preliminary Monitoring Well Instal-
   lation Report for landfill.

April 21, 1986  - EPA issues NOD for the  landfill.

July 8, 1986  -  IT submits Site Characterization report.
     Note:  This  listing does not include Agency (i.e., State
           and Federal) reviews and comments.

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                               -10-


D. HYDROGEOLOGY

                    1. Site Geology

     IT has reported that the geology of the site consists pri-
marily of nearly flat-lying lake bed deposits overlain by a thin
veneer of eolian and alluvial-wash deposits (Figure 6).  The
alluvial deposits are composed of surface and near-surface sands
and silts.  Thicknesses range from thin  (i.e., a few inches) wash
deposits to thick (i.e., up to twenty feet) channel-fill deposits.
The lacustrine deposits are made of partially indurated and inter-
bedded clays, silts, and sands and comprise the major stratigraphic
sequence at the site.  The lacustrine sediments most likely
represent transgressive and regressive depositional episodes.
The facility has grouped the lake bed deposits into ten strat-
igraphic units (Figure 7) and are as follows:


  (QLl)  Very Thickly to Thickly Bedded Unit (consists of clays,
        silts, and silty sands);

  (QL2)  Thinly Laminated Clay;

  (QLB)  Massive Moderate Brown Clay;

  (QL4)  Thin-Bedded Silt and Clay;

  (QL5)  Ripple-Marked Sand;

  (C/Lg)  Massive Mottled Gray and Brown Clay;

  (QL7)  Thinly-Bedded Silt, Silty Sand, and Clay;

        Gray Silty Sand;

        Massive Clay; and

        Undif ferentiated Clay, Silt, and Silty Sand.
     The sediments dip gently (i.e., a few degrees) to the north-
east.  Minor broad folds may be locally observed.  Sand-filled
fractures observed in the field and recorded in stratigraphic
sections indicate remnant dessication features as  evidenced
by fracture configuration (including vertical extent) and sediment
orientation.  Soft-sediment deformation and buried stream channels
are localized features.  The occurrence and distribution of the
stream channel deposits are unknown.  The channel  deposit sediments
appear to be near-surface phenomena (i.e., less than twenty foot
depth) .

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                           -11-
     The facility has identified eight  (8) faults on-site  (Figure
6).  The faults trend north-south, are  generally  less  than  a  few
thousand feet in length, and are near-vertical in orientation
with the east side downthrown. Vertical off-set has  been estimated
to range from a few inches to tens of feet.  The  faults appear to
b_e secondary features related to regional  tectonics.   The  faults
transect the lake beds suggesting Quaternary displacement.  Two
(2) faults  (D and F) occur near the surface  impoundments.   Fault D
intersects the northern boundary of pond 9 and fault F trends
just west of the surface impoundments.  The  facility was invest-
igating the occurrence of fault D in pond  9 during the writing
of this report.

                   2. Site Hydrogeology

     The facility has reported that ground water  at  the site
occurs in two hydrostratigrapic units;  a shallow  unconfined unit
and a deep confined unit.  Identification  of the  aquifers has
been based upon stratigraphic data and  TDS values.  The shallow
aquifer has been correlated with stratigraphic unit 0^5 with  a
TDS value averaging  3000 mg/1.   The aquifer exhibits spatial
variability for occurrence and composition.  Permeability and
hydraulic conductivity are variable in  this anisotropic environ-
ment.  The aquifer is composed of silty and well-sorted fine
sands in the area of the landfill whereas  the same sediments have
been reported to be discontinuous or missing in the  southeastern
portion of the site.  The aquifer has been reported in the Site
Characterization report as being water-bearing only east of fault
C and north of the main wash (Figure 6).

     A review of boring logs in the area of  the surface impound-
ments confirms the spatial variability  of stratigraphic unit
OLS, especially from that described in  the comprehensive reports
detailing the hydrogeology in the landfill area.   The logs for
piezometers P-26, P-27, and P-32 indicate  a mostly silt and clay
composition for unit QLS   Water was indicated only in boring P-27
in a thin basal sand in unit QLS-   Borings DS-3 and DS-4 consist
entirely of fine-grained material.   Additionally,  low water yields
from wells 18, 6A, and 7A contrast with the relatively high yields
from the landfill wells.   Overall,  the unit has been described as
averaging between fifteen and twenty feet  thick,   lacking full
saturation, and generally occurring at a depth of  between thirty
and fifty feet across the site though it does outcrop at the
surface along the main wash.

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                           -12-


     Hydraulic gradients in the shallow aquifer have been estima-
ted by the facility to be northeasterly at eight feet per mile
(8 ft/mile) in the area of the landfill (Figure 8).  Recharge to
the shallow aquifer near the landfill has been attributed by the
facility in part to flow from the confined deep aquifer across
f-ault C where the sands of units Q^Q and 0^$ are in contact
(Figure 9), and vertically along the fault in areas of vertical
displacement between the same two units.  The main wash is believed
to be an additional recharge source.  IT has used water quality
results, water elevations, and stratigraphic relationships as sup-
porting evidence.  Note that infiltration from the main wash
would not appear large enough to compensate for the lower dissolved
solids content nor account for the homogeneous distribution of
TDS values found in the shallow aquifer.

     The deep aquifer is the major water-bearing unit and appears
to be present everywhere beneath the site.  The facility has
identified the deep aquifer as consisting of all saturated units
within and below stratigraphic unit OLS* though the sands of unit
QLS have been described as the main water-bearing zone.  The deep
aquifer is first encountered at a depth of around seventy-five to
eighty feet and consists of well-sorted fine sands with a thick-
ness of ten to twenty feet.  Latest reports (e.g., Site Character-
ization study) have indicated that this saturated zone may be the
uppermost expression of a vertically extensive regional ground-
water reservoir hundreds to thousands of feet thick.  The hydraulic
gradient has been estimated to be ten feet per mile sloping in a
northeasterly direction.  Water elevations have been reported to
range from one hundred thirty-five to one hundred fifty feet
below mean sea level  (Figure 10).  Fault C has been cited as
locally influencing flow within the deep aquifer by acting as
a hydraulic sink as flow occurs along and across the fault.
Hydraulic head has been reported to be distinctly higher in the
deep aquifer than in  the shallow aquifer near the landfill.  The
head difference is not as evident in the southeastern corner of
the site  (i.e., in the area of the surface impoundments).  TDS
values have been reported as averaging 5000 mg/1.  A withdrawal
well located near pond 9 is not in use.

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                               -13-
                    3. Data Inconsistencies

The following inconsistencies concern hydrogeologic data reported
by the facility:

1) Occurrence of the shallow ground water system.

     a) Shallow aquifer - Described in the Site Characterization
report as missing or thin and discontinuous in the southeastern
corner of the site  (i.e., area of the surface impoundments).  The
ground water contour map for the shallow aquifer contained in the
same report did not extend to this area.  The amended Part B
application identified the shallow aquifer as water-bearing north
of the main wash and surface impoundments.  However, all the
shallow aquifer wells and piezometers in the southeastern portion
of the site have had reportable ground water levels.

     b) Unit QLS - Described in the Site Characterization report
as consisting of sands with a thickness estimated to be fifteen
feet along the southern perimeter of the site.  The same report
described the sands as being absent in the southeastern corner of
the site.  Boring logs from the area described fine-grained sed-
iments .

2) Well Designation/Aquifer Identification (comments are based
upon cross sections contained in the July, 1986, Site Character-
ization report ) .

     a) Well 5A - Identified in Part B submittals as a deep aquifer
well.  The water level source designation in cross section H-H '
(Figure 14) was the shallow aquifer and in cross section E-E1
(Figure 12) it was  the main water body  (i.e., deep aquifer).
Based  upon water quality data (i.e., total dissolved solids), it
appears that well 5A monitors the deep aquifer and above inconsis-
tencies reflect errors in data reproducibility .

     b) Well 7A - Identified in Part B submittals as a shallow
aquifer well.  Cross section A-A1 (Figure 11) contained a deep
aquifer water level designation.  Well 7A was screened in unit
    which had been  identified with the deep aquifer system.
     c) Well 13A - Identified in Part B submittals as a deep
aquifer well.  The Site Characterization  report  indicated  a shallow
aquifer designation.  Well 13A was screened in units QLS and
Water quality data suggests  the well monitors  the  shallow
aquifer.

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                               -14-


     d) Piezometer P-26 was designated as a shallow aquifer well.
P-26 monitors unit QLS which had been identified as being part of
the deep aquifer system.

     It is not clear if the distinction between shallow wells
and main aquifer wells in the area of the surface impoundments
is based upon water quality data, water level information, or
stratigraphic information.  There does not appear to be sufficient
evidence to make such a distinction.

E. Vadose Zone and Contaminant Migration

     The unsaturated zone in the vicinity of the surface impound-
ments is composed of silts, clays, and sands as documented in the
boring logs of piezometers, monitoring wells, and exploratory
borings and results from cone penetrometer tests.  Reports
by LeRoy Crandall and Associates identified the presence of seeps
and damp areas along surface impoundment keyways.  The June 28,
1983, inspection report of pond 8 and the May 11, 1983, explora-
tory drilling report for ponds 4,5, and 8 indicated subsurface
fluid migration from the eastern embankment of pond 8.  Unsatur-
ated flow was occurring at shallow depths along sand lenses in
contact with the surface impoundment.  Fluid migration was
limited to the area adjacent to the surface impoundment.

     Borings DS-1 through DS-6 were drilled within and around the
surface impoundments to a depth of at least fifty feet as part
of a dike stability study conducted in 1985.  Two of the boring
logs (DS-3 and DS-4) described the silts and clays as being moist
to wet from surface to depth.   No other boring logs had been
similarly described for near surface moisture conditions.  Borings
DS-3 and DS-4 were located adjacent to ponds 5 and 3 which held
liquid wastes.  Although fluid loss was inevitable from the impoud-
ments as a result of moisture  flux across the pond bottoms, there
was insufficient data to determine the source of the moisture
conditions described in the lithologic logs.

     There is no unsaturated zone monitoring system for the
surface impoundments.   The impoundments are not lined.  The
thickness of the unsaturated zone exceeds thirty feet.  The
vadose zone consists of heterogeneous sediments.  In this
environment conventional saturated zone monitoring may not be
effective for detection purposes without a complementary vadose
zone monitoring system.

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                           -15-
     The facility has installed a neutron probe system to monitor
the vadose zone in the area of the landfill.  The neutron probe
system is designed to monitor relative moisture content after a
calibration period.  The system provides a vertical profile of
soil moisture conditions.   The facility selected this system over
in-situ sampling devices because of anticipated high negative
suction heads and resultant technical difficulties with sampling.

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                               -16-
F. Well Evaluation

                    1. Well Location
                    a) Distance from unit

     The wells are not at the point of compliance.  Downgradient
wells are located too far from the limit of the waste management
area for detection purposes.  The following distances were estima-
ted from the site geologic map contained in the Hydrogeologic
Characterization report (Figure 6).
Well Number Shortest Distance from Unit
13A
18
6A
7A
8B
8C
9B
9C
900'
150'
175'
300'
750'
750'
1250'
1250'
                 b) Upgradient classification

     Upgradient (background) well:  Well 5A appears to be upgra-
dient of the surface impoundments.  However, well 5A monitors
the deep aquifer and uncertainties regarding ground water occur-
rence and water quality in the area of the impoundments makes this
single well unacceptable for background statistical determinations
The facility has proposed that well 14B and later well 17 be used
as background wells for the shallow aquifer.  However,
are located downgradient of the waste management units
not been demonstrated that the wells are unaffected by
operations.

                 2. Development and Drilling

     Well development appears to have been inadequate based upon
the lack of well completion criteria and development method.
Decreased yields (e.g., wells 6A, 7A, and 18) may be due in part
to inadequate well development, particularly since the wells were
drilled and screened in fine-grained sediments.  The use of
hollow-stem augers as a drilling method was appropriate for
both wells
and it has
facility

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                               -17-


this environment (low-yielding and fine-grained sediments).

                   3. Screen Specifications

     Screen specifications for the monitoring wells are inadequate.
The following comments address screen design and observed problems
with well performance.

     1)  Sieve analyses were not conducted on the screened forma-
tion.  No correlation was made between sediment size and filter
pack/screen design.  Based upon grain size descriptions contained
in the lithologic logs and screen design considerations, it
appears that the slot size is not correct for this environment.

     2)  The same slot size was used despite the variation in
formational characteristics (e.g., well 5A was screened in
sands and well 18 in clays).

     3)  All of the wells produced turbid water during purging
and sampling.  Turbidity values for selected wells ranged from
31.7 Nephelometric Turbidity Units (NTU) in well 13A to 108.6 NTU
for well 5A.  NTU values above five (5) are considered high.

     4)  Sedimentation was evident in several wells as depth
to bottom recordings were substantially above depth of casing
figures (e.g., five feet in well 5A and thirteen feet in well
8C).  Sand-sized particles were withdrawn from a number of wells.
Filter pack material was removed from well 6A.

     5)  The use of slotted pipe may not be appropriate in this
environment due to the combination of low percent open area
provided by slots, the low yield of the aquifer, and the need
for adequate well development.

          4. Filter Pack, Sealant, and Casing Material

     Information was not provided on the selection of filter pack
specifications.  Determinations regarding the adequacy of filter
pack material were not possible since sieve analyses were not
conducted on the formation.  However, some of the aforementioned
problems with well performance and screen selection are symptomatic
of an inadequate filter pack.

     Bentonite pellets will not provide an adequate seal in
the wells.   The sealant is above the recorded formational
saturation levels.  The use of PVC as a screen material could
not be assessed given the lack of available information on
water quality, waste types, constituent mobility, and
recharge rates.

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                               -18-
                     5. Screen Placement

     Based upon boring log information (i.e., saturated/permeable
zones) and available ground water elevation data, vertical screen
placement appears to be adequate in relation to identifiable
flow zones with the exception of well 7A where a wet silty sand
(forty-eight foot depth) is not open to the well.  Correlation
is not obvious for wells 8C and 9C.  Water levels (May, 1985
and January, 1986) for wells 5A, 6A, 8B, 9B, and 13A fall
within screened intervals.  Reported wet/saturated conditions
(per boring logs) for wells 5A, 8C, 9B, and 18 coincide with
screened intervals (Table 2).  Saturated zone noted in log for
well 13A coincides with filter pack interval.  Additional
information on the occurrence and characteristics of the ground
water in the area of the surface impoundments is needed before
definitive conclusions can be made regarding vertical screen
placement.

              6. Water Elevations, Water Quality, and
                 Statistical Determinations

     Ground water elevations recorded by the Task Force generally
agree (i.e., most within one foot) with facility water levels of
May, 1985 and January, 1986, but not with June, 1986, levels.
The source of the discrepancies (up to ten feet) is unknown
although it may be due to changes in data reporting.  Note that
uncertainties with temporal variations and past measurement
techniques may impact comparative analyses.  Limited water
level information for the area of the impoundments makes qual-
itative trend determinations impossible.

     The survey datum used to record depth to water for each
well must be clearly identified.  The facility has reported
that the tops of the inner casings have been used as reference
points although the tops of the casings are not level.  Black
marks noticeable on the inside of some casings are assumed to
serve as reference datums.

     Historical water quality results for the facility's RCRA
wells indicate both temporal and spatial fluctuations in concen-
trations.  No correlation can be made as to trend or significance
of the data.  Maximum contaminant levels (MCLs) were exceeded
for several constituents.  It is not kn'own if the constituents
were noted by the facility.  Analytical results were available
for wells 5A, 8B, 8C, 9B, 9C, and 18.  It is not known what
water quality data has been generated for wells 6A and 7A.  The
following two lists contain; 1) sampling quarters used for data
evaluation and 2) parameters that exceeded MCLs:

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                          -19-
                       Sampling Quarters
       Well 5A
       Well 8B
       Well 8C
       Well 9B
       Well 9C -
       Well 13A
       Well 18 -
          2nd quarter
          1st quarter
          4th quarter
          4th quarter
           (excluding
            quarter
        '85
        '85
        '83
        '83
        4th
      '85 -
          4th quarter
           2nd quarter
          2nd quarter
        '84
         '85
        '85
            quarter
            quarter
            quarter
            quarter
            and 2nd
            sampling)
            quarter '85
'85
'85
'85
'85
through 4th
through 3rd
through 2nd
through 3rd
quarter '84
semi-annual
through 3rd
 and 3rd quarter '85
through 4th quarter '85
                  Parameters that exceeded MCLs
                                 '85
                                 '85
Well 5A - Pb, 4th quarter
          Hg, 3rd quarter
          gross alpha, 4th quarter
          Cr+6, 4th quarter '85
       Well 9B -
       Well 8B
       well 9C
          Cd,
          Cr,
          Pb,
4th quarter
4th quarter
4th quarter
'83
'83
'83
          gross beta, 1st and 3rd quarters '85
          gross beta, 2nd quarter '85
     The facility had not conducted statistical determinations
for wells 5A, 6A, 7A, 13A, and 18 at the time of the Task
Force investigation.   The wells were installed in 1985 and
had not been in operation for a year.   It is not known if
statistical data had  been generated for wells 8B, 8C, 9B, and
9C.  The facility also had not conducted complete suites
of required first year analyses for the wells.  Data omissions
ranged from single to multiple parameter(s)  per quarterly
reporting period (e.g., from fluoride  for well 18 in 4th quarter
'85 to most parameters for well 9C in  1st quarter '85).

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                               -20-


                           7. (Table 1)


Well Construction Details

     The following information on well design was derived from
well installation reports and Figures 4  and 5.

                     Wells 8B, 8C, 9B, and 9C

a)  Drilling Method - Twelve (12)-inch diameter hollow-stem flight
    auger.

b)  Well Casing Specification - Four (4)-inch diameter schedule
    40 PVC casing, 0.020 slotted screen  (no information on jointing)

c)  Annular Seal - Bentonite pellet seal overlain by cement grout
    (no information on material specifications  and installation
    procedures).

d)  Filter Pack - Washed filter sand (no specifications given).

e)  Well Integrity - Protective steel locking cap over PVC stick-
    up.  No cement surface pad.

                   Wells 5A, 6A, 7A, 13A, and 18

a)  Drilling Method - Ten (lO)-inch diameter continuous flight
    hollow-stem auger.

b)  Well Casing Specification - Four (4)-inch diameter schedule
    40 threaded-joint PVC casing, 0.020  slotted screen.

c)  Annular Seal - Bentonite pellet seal overlain by cement/ben-
    tonite grout (no information on material specifications and
    installation procedures).

d)  Filter Pack - Well 6A - #20 silica sand, Wells 18, 13A, & 5a -
    #3 monterey sand, Well 7A - #3 monterey & #20 silica sand.

e)  Well Integrity - Protective steel locking cap over PVC stick-
    up.  No cement surface pad.

Well Completion (i.e., development)

Wells 8B, 8C, 9B, and 9C - No information available.

Wells 5A, 6A, 7A, 13A, & 18 - Bailer and compressed air lines (air
jetting).  Distilled water added.  No records of sequence times,
amounts of water evacuated, water clarity, etc.

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              8.  (TABLE 2)
             WELL INFORMATION

(information excerpted from facility submittals)
Well Number
5A
6A
7A
13A
18
8B
8C
9B
9C
Depth
(ft.)
75
70
70
75
87
60
100
60
105
Elevation
(top of casing
as expressed
as BMSL in ft.)
-67.01
-89.14
-93.13
-71.57
-79.01
-95.57
-97.96
-103.68
[-103.98
Elevation of
Ground Surface
(expressed as
BMSL in ft.)





-99.62
-99.85
-105.60
-105.96
Designated
Deep (D) or
Shallow (S)
Aquifer Well
D
S
S
D
D
S
D
S
D
Borehole
Diameter
( inches )
10
10
10
10
10
10 5/8
10 5/8
10 5/8
10 5/8
Casing
I.D.
( inches )
4
4
4
4
4
4
4
4
4
Depth of
Casing
(ft.)
68
65
66
70
87
100
100
60
105
                                                                             I
                                                                             K>

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               9.  (TABLE 3)
                 WELL DESIGN

(information excerpted from facility sutmittals)
Well
Number
5A
13A
18
6A
7A
8B
8C
9B
9C
Depth
(ft.)
75
75
87
70
70
60
100
60
100
Screened
Interval
(depth
in ft.)
58-68
60-70
77-87
55-65
56-66
40-60
80-100
40-60
80-105
Medium
Screened
and
Strat.
Unit
sand
OLS
sand
QLS & Or.fi
clay
Or* - Qr.q
sand & clay
Or.5
clay
Qr.fi
silty sand
OL5
clay, sandy
silt and
silty sand
QusrQiA
sand with
sane silty &
clayey sand
OF.5
clay
QL6-QL8
Wet and/or
Saturated
Conditions
Noted in
Logs (depth
in ft.)
61
58
82
none indicated
48
98-100
(water level in
borehole  40')
as above
42-56
as above
Added Notes
Sand unit 52' - 67'
underlying clays
described as wet
to saturated
Sand unit 39' - 67'
Clay 67 - 68
Sand 68 - 75
Interbedded
sand 82 - 84.5
Sand 57 - 61
Sand 48 - 49.5
Silty sand 38 - 60

Clayey sand 56 - 62
Sand 62 - 70

Filter Pack
Interval
(depth in ft.)
56 - 73
56 - 75
72 - 87
53 - 67.5
52 - 68
no specs.
no specs.
no specs.
no specs.
                                                                             I
                                                                            10
                                                                            K>

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                            -23-
                       10. Conclusions

     The ground water monitoring system for the surface impound-
ments is not adequate for detection purposes.  The system would
fail based upon well location criteria alone regardless of
other evaluation criteria.  The wells are improperly designed,
constructed, and completed.  The uppermost aquifer has not
been defined.  A single statement in the Site Characterization
report describing the shallow aquifer as "missing or thin and
discontinuous" is inadequate.  The ground water analytical data
base is insufficient.

                     11. Recommendations

     The facility must define the uppermost aquifer including
composition, occurrence, saturated thickness, and hydraulic
characteristics.  Well design specifications must be based
upon site-specific hydrogeologic and waste management infor-
mation.  Sieve analyses and in-situ hydraulic testing (e.g.,
slug/pump tests) must be performed.  Monitoring wells must be
located in the vicinity of the waste management units.  A more
vigorous well development method and a better annular sealant
(e.g., granular bentonite with in-situ hydration) are needed.
Larger diameter wells may be necessary to enhance sampling and
development in the low yielding formations.  The method for
determining water levels for each well (including the use of
reference datums) must be identified.  Water level data should
be summarized for each well.  Temporal variations should be
delineated.  The facility should investigate the significance
of the anomalous moisture descriptions in the lithologic logs
and determinine the need and feasibility of an unsaturated zone
monitoring system in the area of the surface impoundments.
Soil-moisture calibration devices (e.g., neutron probe)  may not
be effective due to prior facility operations.

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                              -24-
G. Analytical Results

      Organic analyses indicated no conclusive evidence of
ground water contamination.  Five (5) organic compounds (i.e.,
four volatile and one extractable) were detected.  Two (2) of
the volatile compounds, methylene chloride and acetone, were
detected in all the blank samples indicating probable laboratory
contamination.  The third volatile organic, chloroform, was
detected in the performance evaluation blank and one equipment
blank.  The fourth volatile organic, carbon tetrachloride, was
detected in the aforementioned equipment blank.  The latter two
constituents were detected in a facility equipment blank indica-
ting probable test water or equipment contamination.  The
extractable organic compound, bis 2-ethylhexyl, was detected in
well 17.  The source of this plasticizer compound was unknown.
Unidentified organic compounds (i.e., TOC analyses) were
detected in a number of samples including a relatively high
value in well 6A.  Inorganic analyses were inconclusive.
Detected levels of inorganic constituents varied within normal
ranges.  Refer to Kevin Wong's report on sample data review for
more information.

     Comparisons between historical facility analytical results
and Task Force data indicated higher concentrations for a few
constituents (e.g., Fe, Mn, and Se) in Task Force samples.
Comparative results were determined for wells 5A, 8B, and 18.

H. Facility Laboratory Analysis

     The facility's ground water analytical laboratory in
Pittsburgh, PA was found to have acceptable practices.  The
data generated by the laboratory was generally considered to be
of acceptable quality.  Refer to Kevin Wong's report on the
Pittsburgh, PA laboratory for additional information.

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                              -25-


I. Compliance with Ground Water Monitoring


     The following is a summary list of potential RCRA violations
for selected requirements in 40 CFR 265 Subpart F - Ground Water
Monitoring and 270.14(c) - Permit Application


     a) 265.90 - An adequate ground water monitoring program
capable of determining the facility's impact on the uppermost
aquifer has not been implemented.

     b) 265.91 - The ground water monitoring wells are improperly
located and designed to ensure immediate detection of statistical-
ly significant amounts of hazardous constituents that migrate
from the waste management area to the uppermost aquifer.

     c) 265.92 - There is an insufficient analytical data base.
Analyses have not been conducted for all required parameters.
The sampling and analysis plan needs revising.

     d) 265.93 - Required statistical comparisons have not
been conducted.

     e) 270.14(c) - The uppermost aquifer' has not been adequately
defined including occurrence, extent, and hydraulic characteristics.


J. Summary of Recommendations and Concluding Remarks


     The facility must clearly delineate the occurrence and
characteristics of the uppermost aquifer in the area of the
surface impoundments.  A new detection monitoring system must
be installed by the facility.  Wells must be located in the
vicinity of the waste management units.  The number, location,
and design of the wells must be based upon site specific hydro-
geological and waste management criteria.  The sampling and
analysis plan needs to be revised.  Required analytical
and statistical data must be generated.  The impact of the
waste management units on ground water quality can not
be determined due to inappropriate well locations.

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                                -26-


                             References

          (All  listed  references are  unpublished  reports)

 1)  Emcon,  "Geotechnical  Investigation and  Design Study,  Geothermal
 Waste  Disposal  Facility,  Imperial County,"  December,  1982.

 2)  IT  Corporation,  "Hydrogeological  Data Report-Area  of  Proposed
 Landfill," January, 1986.

 3)  IT  Corporation,  "Proposal for Ground-Water and Unsaturated-Zone
 Monitoring Programs at IT Corporation's Imperial Valley  Landfill,
 January, 1986.

 4)  IT  Corporation,  "As-Built Geologic Report, Landfill Construction,
 IT  Corporation,  Imperial  Valley Facility,  Imperial  County,
 California," June,  1985.

 5)  IT  Corporation,  "Resource Conservation and Recovery Act  (RCRA)
 Permit Application  (Part  B), IT Corporation, Imperial Valley
 Facility, Westmorland, California," August  1, 1985.

 6)  IT  Corporation,  "Proposed Ground Water Monitoring  Program,
 Technical Report.   IT Corporation Imperial  Valley Facility", May
 1985.

 7)  IT  Corporation,  "Hydrogeologic Characterization", July 8, 1986.

 8)  IT  Corporation,  "Monitoring  Well Installation",  Preliminary
 Report, March,  1986.

 9)  IT  Corporation,  "Hydraulic Conductivity  Testing, Clay Test
 Fill - Phase II", June, 1986.

 10) LeRoy Crandall and Associates, "Report  of Geotechnical  Investi-
 gation, Proposed Class II-I Waste Disposal  Site, Westmorland District,
 Imperial Valley, California," January 9, 1980.

 11) LeRoy Crandall and Associates, "Fault Study," December  19, 1980.

 12) LeRoy Crandall and Associates, "Results of Permeability Deter-
mination, Pond No. 8,  Phase I," December 24, 1980.

 13) LeRoy Crandall and Associates, "Results of Permeability Deter-
mination, Pond No. 5,  Phase I,  January 9,  1981.

 14) LeRoy Crandall and Associates, "Results of Permeability Deter-
mination, Pond No. 3,  Phase I", January 15, 1981.

-------
                                -27-


 15)  LeRoy Crandall and Associates, "Completion  Report,  Monitoring
 Wells,  Imperial Valley Site", March 6, 1981.

 16)  LeRoy Crandall and Associates, "Report of Geotechnical  Evalu-
 ation,  Phase I Area, Immediately North of the Existing  Operation
 Area",  May 18, 1982.

 17)  LeRoy Crandall and Associates, "Verification of Clay Thickness
 and  Keyway Inspection, Pond No. 9", January 7,  1983.

 18)  LeRoy Crandall and Associates, "Results of Verification of Clay
 Thickness and Permeability Determination, Pond  No. 9",  December
 15,  1982.

 19)  LeRoy Crandall and Associates, "Results of Exploratory Drilling,
 Western Berm of Pond No. 4, Eastern Berm of Ponds Nos.  5 and 8,
 and Northern and Western Dikes of Ponds No. 8",  May 11, 1983.

 20)  LeRoy Crandall and Associates, "Results of  Inspection of Pond 8
Cutoff Wall  Keyway",  June 28,  1985.

 21) US EPA,  "RCRA Ground Water Investigation", March 27, 1984.

-------
     vurr    sun
                                                  EXPLANATION
                                                 Quaternary (Holoccne) alluvium.
                                                  dune tand. and lake dcpout*
                                                 Ccnooic nratincd rodu and
                                                  uiMrtModcd vo^cuucnxiui
                                                 Prt-Ononxc oy
-------
 - r     , ,-..     i t.1^: i :'_('
\   X-,     ^j-     ,i J ;,, ' WCMWi

vv  *, 's* "jL^iiifinESf
                                                 	l^	1


                                                I \        \ rlJB Y'"
                                                i             -ii  ^>
                                                                           Figure 2

                                                                        Location Map

                                                                     Source:  IT Corp. Part B

                                                                              7/8/86

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NI2
                                      Figure 3

                                   Vicinity Map
                                Source:  IT Corp.  Part B
                                          7/8/86

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U.S. Environmental Protection Agency
Region 5, Library (PL-12J)
77 West Jackson Boulevard, 12th Floor
        It  0604*3590

-------