May 1987 EPA-700 8-87-015
SEPA
Hazardous Waste Ground-Water
Task Force
Evaluation of the
IT Panoche Facility
Benicia, CA
US Environmental Protection Agency
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EPA-7008-87-015
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
HAZARDOUS WASTE GROUND WATER TASK FORCE
GROUND WATER MONITORING EVALUATION
IT PANOCHE DISPOSAL FACILITY
BENICIA, CALIFORNIA
May 1987
Hannibal Joma
Project Leader
U.S. Environmental Protection Agency
Region 9
U.S. Environmental Protection Agency
77 West Jackson Boulevard, 12th floor
Chicago, IL 60604-3590
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CONTENTS
I. Executive Summary
A. INTRODUCTION 1
B. OBJECTIVES 1
C. INVESTIGATION METHODS
1. Sampling Program 2
2. Records Review 2
3. Facility Inspection 3
4. Facility Sampling Audit and Laboratory Evaluation 3
D. TASK FORCE PARTICIPANTS AND ROLES 4
F. SUMMARY OF FINDINGS AND CONCLUSIONS 4
1. Contamination in Ground Water and Potential Impact
on Surface Water and Soil 5
1.1 Statistical Analysis Results 5
1.2 HWGWTF Analysis Results 5
2. Compliance with §265 and §264 (40 C.F.R.)
2.1 Evaluation of Construction of Monitoring Wells 8
2.2 Evaluation of Detection and Assessment
Monitoring 8
2.3 Evaluation of Upgradient Background Wells 10
2.4 Ground Water Sampling and Analysis 10
3. Additional Information Requirements, §270(40 C.F.R.)
3.1 Hydrogeologic Characterization 11
4. Compliance with Superfund Off-Site Policy 13
5. Facility Sampling and Laboratory Audits
5.1 Results of HWGWTF Sampling Audit 14
5.2 Results of HWGWTF Laboratory Audits 15
•
II. DATA REVIEW
A. SITE DESCRIPTION AND ADJACENT WATER/LAND USE 17
B. WASTE MANAGEMENT UNITS AND FACILITY OPERATIONS 17
1. Background 18
2. Wastes Managed by the Facility 19
3. Surface Impoundments 20
4. Landfills 20
5. Bio-Areas 21
6. Waste Piles 22
7. Drum Buria/1' .A^eas ,,* •-, , ,,*,,,,, , = t> 22
8. Current Status "of .".Operattprii ; at/'the Facility
8.1 Landfill Expansion;'* /, ']t*' ei\ 22
8.2 Drum Burial' iCrea A.sfse"sVmVnt'' 25
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C. SITE PHYSIOGRAPHIC SETTING, TOPOGRAPHY 25
D.. SITE" GEOLOGIC/HYDROGEOLOGIC, AND STRUCTURAL SETTINGS
1. Geological Setting 26
2. Hydrogeologic Setting 28
3. Structural Geology 30
3.1 Need for Additional Fault Investigations 30
E. GROUND WATER'MONITORING SYSTEM 33
1. Well Design and Development/Well Information 34
2. Evaluation of Detection Ground Water Monitoring
System 45
2.1 Construction Evaluation 45
2.2 Location Evaluation 47
3. Aquifer Test/Identification of Lower Boundary 48
F. CONTAMINANT PLUMES, FACILITY'S ASSESSMENT MONITORING
PLANS 50
1. Area West, Southwest of Ponds 12-16 51
2. North Drum Burial Area 53
3. Ponds 0, P and Q Area 54
4. Area South of Ponds 1 and 2 54
G. EVALUATION OF FACILITY'S ASSESSMENT PLANS
1. Ponds 12 Through 16 55
1.1 Additional EPA Requests 56
2. South of Ponds 1 and 2 57
2.1 Additional EPA Requests 53
3. Ponds 0, P, Q, and Solid Waste Management Unit 61 59
3.1 Additional EPA Requests 59
4. North Drum Burial Area 61
5. South of Pond 8 Series 61
6. Summary of Evaluations Regarding Detection and
Assessment Monitoring 62
H. SUMMARY OF STATISTICAL ANALYSIS PERFORMED ON FACILITY'S
DATA, AND PWGWTF SAMPLING RESULTS
1. Ground Water Statistical Results 63
2. HWGWTF Ground Water Sampling Results 65
3. HWGWTF Surface Water and Soil Sampling Results 66
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I. REVISIONS REGARDING SAMPLING AND ANALYSIS PLANS
J.
1. -Ground Water Sampling and Analysis
2. Surface Water and Soil Sampling
EVALUATION OF STATISTICAL METHODOLOGY PROPOSED BY
IT CORPORATION FOR THE PANOCHE FACILITY
REFERENCES
ATTACHMENTS
Attachment A
Attachment B
Attachment C
Attachment D
Attachment E
Attachment F
67
68
68
69
TABLES
Table 1
Table 2
Table 3
Table 4
Table 5
Table 6
Table 7
FIGURES
Figure 1
Figure 2
IT Panoche Sampling and Documentation Report
IT Panoche Ground Water Sampling Audit
IT Panoche Laboratory Audit Report
Review of the Statistical Methodology Proposed by
IT Corporation for the Panoche Facility
Chronology of Ground Water Enforcement Actions
Ground Water Investigations Underway at IT Panoche
Pursuant to RWQCB Cleanup and Abatement Order.
Addiditonal Activities Required by EPA as a Result
of the Task Force Report.
Beneficial Water Use in the Vicinity of IT Panoche Facility
General Characteristics and the Wells in Each Cluster
ANOVA Test Results for the Indicator Parameters Between
Background Well (MW-16) and Other Selected Wells
Average Concentrations (mg/L) of Selected Indicators in
Wells MW-16, MW-35 Through MW-39
HWGWTF Ground WAter Monitoring Data, August 1986
HWGWTF Surface Water Quality Data, August 1986
HWGWTF Soil Quality Data, August 1986
Site Location Map
Borehole Location Map (including Location of Waste
Management Units)
Figure 3 Expansion Project Plan
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Figure 4 .. Project Cross-Section
Figure 5 Regional Physiographic Map
Figure 6 Geologic Map of the Panoche Facility
Figures 7A-7E Geologic Cross-Sections
Figure 8 January Ground Water Contour Map
Figure 9 August Ground Water Contour Map
Figure 10 Watershed Boundaries
Figure 11 Top of the Unweathered Bedrock Contour Map
Figure 12 Air Photo Lineament Interpretation Map
Figure 13 Log of Trench T-79
Figure 14 Log of Trench T-43
Figure 15 Typical Shallow Well Construction
Figure 16 Typical Deep Well Construction
Figure 17 Seeps and Soil Samples Location Map
Figure 13 Location of Proposed Wells at the North Drum Burial Area
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I. EXECUTIVE SUMMARY
A. Introduction
Resource Conservation and Recovery Act (RCRA P.L. 95-580),
regulates the operation of hazardous waste treatment, storage
and disposal facilities (TSDFs). Regulations promulgated pur-
suant to RCRA (40 C.F.R. Parts 260 through 265, effective on
November 19, 1980 and subsequently modified) address hazardous
waste site operations including monitoring of ground water to
ensure that hazardous waste constituents are not released to
the environment. The regulations for TSDFs are implemented
(for EPA administered programs) through the hazardous waste
permit program as outlined in 40 C.F.R. Part 270.
The Administrator of the Environmental Protection Agency
(EPA) established a Hazardous Waste Ground Water Task Force
(Task Force) to evaluate the level of compliance with ground
water monitoring requirements at commercial off-site TSDFs and
address the causes of poor compliance. The Task Force is com-
prised of personnel from the EPA Headquarters core team, the
Regional Offices and the States.
B. Objectives
The primary objectives of the inspection at IT Panoche were
to evaluate:
" Compliance with the regulations in 40 C.F.R., Part 265,
Subpart F, "Interim Status Standards for Ground Water
Monitoring", and potential compliance with the rules set
forth in Part 264, "Standards for Owners and Operators
of Hazardous Waste Treatment, Storage, and Disposal
Facilities" and Part 270, Subpart B, Section 270.14(c),
"Additional Information Requirements."
*
* Potential contamination in the ground water.
0 Compliance with ground water aspects of the Superfund
off-site policy.
The IT Panoche facility has received wastes from Superfund
Sites where response actions are being conducted under the Com-
prehensive Environmental Response, Compensation and Liability
Act (CERCLA - P. L. 96-510). Under current policy, specific
land disposal units used for Superfund Wastes must be in compli-
ance with the Part 265 ground water monitoring requirements,*
and new provisions of Superfund Amendments and Reauthorization
Act of 1986 (SARA).
* May 6, 1985 memorandum from Jack McGraw on "Procedures for
Planning and Implementing Off-site Response" or constituents
that have migrated from the waste management area to the
upper-most aquifer underlying the facility.
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.. More specific objectives of the investigation were to determine
if:
1. The ground water monitoring system can immediately detect
any statistically significant amounts of hazardous waste
2. Designated RCRA monitoring wells are properly located and
constructed (to the extent possible).
3. IT Panoche has developed and is following an adequate plan
and procedures for ground water sampling and analysis.
4. Required analyses have been conducted on samples from the
designated RCRA monitoring wells.
5. The ground water quality assessment program plan is
adequate.
6. Recordkeeping and reporting procedures for ground water
monitoring are adequate.
To accomplish these objectives, the Task Force investiga-
tion was divided into several discrete phases. These included,
a ground water and soil sampling program, laboratory audits, a
sampling audit, facility inspection and a complete record review.
C. Investigation Methods
1. Sampling Program
The sampling program (from August 13, 1966 through
August 29, 1986) involved ground water sampling of 32
facility wells, 6 ground water seeps, and one soil sam-
pling. Peter Rubenstein of EPA Region 9 Field Inspections
Section conducted the sampling with the Task Force sampling
contractor Versar Inc. Sampling documentation report is
included as attachment A of this report*
2. Records Review
Records were reviewed at IT Panoche to verify infor-
mation currently in Government files and to supplement
them with any new information. The facility records were
reviewed regarding waste types and volumes received,
design and construction of waste management units, and
ground water monitoring.
Specific documents and records of interest included
the ground water sampling and analysis plan, the ground
water quality assessment program, analytical results from
past ground, water sampling, monitoring well location,
construction data and logs, reports of site hydrogeological
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conditions, site operation plans, facility permits, unit
'design reports, position description, and qualifications
of selected personnel including experience and training
(relating to the required ground water monitoring), and
operating records showing the general types and quantities
of waste disposed of at the facility and their locations.
3. Facility Inspection
The facility inspection (concurrent with sampling
event) assessed the waste management operations and pollu-
tion control practices, including surface drainage and
leachate management. The inspection also included identi-
fication of pre-RCRA (i.e., before November 19, 1980) waste
management units and their potential impact on ground water
quality. The locations of all designated RCRA monitoring
wells, their depths, construction materials and security
were verified.
4. Facility Sampling Audit and Laboratory Evaluation
Another field investigation portion of this program
was the audit of the facility's sampling procedures.
During the first two weeks of May, 1986, the facility
conducted their required quarterly sampling for RCRA and
State permitting. Task Force personnel observed and
critiqued the facility's sampling and shipping procedures
during that time. The sampling audit report for this
portion of the program is included as attachment B.
Laboratory audits of two of the facility's off-site
labs were conducted by regional chemist, Kevin Wong. The
first audit was conducted on IT's predisposal waste
analysis lab,, located at the IT Vine Hill Facility in
Martinez, California, on March 3rd and 4th, 1986. The
second audit was conducted at IT's laboratory in Pittsburg,
Pennsylvania, on May 12th and 13th, 1986. The last audit
was conducted on IT Panoche oil-site lab on August 27th,
1986. The lab audit reports are included as attachment C
of this report.
The off-site laboratories were evaluated regarding
their respective responsibilities under the ground water
sampling and analysis plan and predisposal waste analysis.
Analytical equipment and methods, quality assurance
procedures, and documentation were examined for adequacy.
Laboratory records were evaluated for completeness,
accuracy, and compliance with State and Federal require-
ments. The ability of each laboratory to produce quality
data for the required analyses, and its past documented
history of doing so, were evaluated.
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D. Task Force Participants and Roles
Dan Sullivan - EPA HQ, Core Team Representative.
Peter Rubenstein - EPA Region IX, Sampling Program Leader.
Kevin Wong - EPA Region IX, Audited On-site and Off-site
Facility Laboratories.
Donn Zuroski - EPA Region IX, Sample Team Member.
Hannibal Joma - EPA Region IX, Project Leader.
Darcy Higgins, John Hatcher, Alicia Fleitas, Don Paquete,
Mark McElroy, Dan Campbell, Randy Vanhoozer - Versar Inc.,
Sample Team Members.
Additionally, Dennis Parfit, SWRCB - Patti Barni, DOHS, and
Wil Bruhns, RWQCB were present on-site occasionally during
the interviews of the facility's personnel.
E. Summary of Findings and Conclusions
The results .of the HWGWTF investigation at the IT Panoche
Facility are discussed in the following paragraphs. The
evaluations deal with the primary objectives of the investigation
which were:
1. Contamination in the ground water.
2. Compliance with "Interim Status Requirements", $265
(40 C.F.R.), and "Standards for Owners and Operators of
' Hazardous Waste Treatment, Storage and Disposal Facilities",
§264 (40 C.F.R.).
3. Compliance with "Additional Information Requirements",
§270 (40 C.F.R.).
4. Compliance with Superfund off-site policy.
5. Facility sampling and laboratory audits.
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1. Contamination in Ground Water and Potential Impact on Surface
Water and Soil;
1.1 Statistical Analysis Results
The results of statistical analysis performed on IT's
data, by EPA's contractor, indicate that relative to the
background, the ground water in the alluvium and weathered
bedrock is contaminated and there is a possibility that ground
water in the upper unweathered bedrock is contaminated as
well. Statistical analysis shows that 29 wells, screened in
alluvial and/or weathered bedrock, are contaminated by indi-
cator parameters (chloride, sulfate, total organic carbons,
total organic halogens/ and specific conductance), and various
heavy metals. These wells are: MW-1, MW-2B, MW-7, MW-10,
MW-13, MW-14, MW-17, MW-21, MW-22, MW-25, MW-26, MW-27, MW-28,
MW-29, MW-31, MW-34, MW-41, MW-43, MW-45, MW-46, MW-47, MW-48,
MW-49, MW-51, MW-52, MW-53, MW-56, C2 and C6.
Contamination of ground water in the upper unweathered
bedrock is implied by the data but not proven due to lack of
sufficient number of deep monitoring wells downgradient from
the waste management units for adequate correlations.
The analysis indicates MW-35 and MW-37, which are
screened in upper unweathered bedrock, show evidence of
chloride contamination. Monitoring well MW-39, which is
screened in deep unweathered bedrock, shows elevated levels
of sulfate, TOG, TOX and specific conductance relative to
the background well (MW-16).
1.2 HWGWTF Analysis Results;
Ground Water Sampling Results
GWTF data confirm the above results and, additionally, the
analyses indicate monitoring wells MW-11, MW-46, MW-7, MW-49,
MW-48 and MW-51 show positive results for volatile organics.
' MW-7 indicated 0.0069 ppm of tetrachloroethene;
' MW-11 indicated 0.0038 ppm of chloroform, 0.0012 ppm
of 1,2-dichloroethane, 0.0015 ppm of trans-1,2-
dichloroethene, 0.0038 ppm of 1,2-dichloropropane,
0.0093 ppm of 4-methyl-2-pentanone, 0.0018 ppm
of 1,1,1-trichloroethane, 0.0084 ppm of TCE and
0.0016 ppm of 1,2-dibromoethane.
• MW-46 indicated 0.0072 ppm of 1,2-dichloroethane,
0.0056 ppm of trans-l,2-dichloroethene and
0.0054 ppm of TCE.
• MW-48 indicated 0.0066 ppm of TCE;
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*-- MW-49 indicated 0.0019 ppm of chloroform and
0 MW-51 indicated 0.11 ppm of tetrachloroethene.
In addition some of these wells tested positive for
other volatile organic compounds like benzene, carbon
tetrachloride, 1,1 dichloroethane and freon at levels
below the generally accepted detection limits.
All the wells (31 monitoring wells, one piezometer)
that were sampled by GWTF showed at least one inorganic
indicator or heavy metal value above background (except
MW-9A). The maximum concentrations were:
- chloride: 36,200 ppm MW-49
- TOX: 0.675 ppm MW-49
- Nitrate nitrogen: 67.50 ppm MW-46
- Sulfate: 1,130 ppm MW-39
- Amonia nitrogen: 2.10 ppm MW-36
- Bromide: 60 ppm MW-21
- TOG: 212 . ppm MW-17
With respect to metals, the following is a list of the
maximum concentrations detected for metals where the background
value was exceeded:
- Barium: 6.29 ppm MW-49
- Calcium: 9,590 ppm MW-49
- Cadmium: 0.134 ppm MW-49
- Cobalt: 0.758 ppm MW-49
- Copper: 0.107 ppm MW-49
- Magnesium: 4,490 ppm MW-49
- Manganese: 880 ppm MW-49
- Nickel: 1.64 ppm MW-49
- Potassium: 21.8 ppm MW-49
- Vanadium: 0.129 ppm MW-49
- Aluminum.: 16.60 ppm MW-47
- Iron: 15.40 ppm MW-47
- Sodium: 1,100 ppm MW-17
- Selenium: 0.029 ppm MW-14
- Arsenic: 0.03 ppm MW-8
- Lead: 0.004 ppm MW-4
- Silver: 0.042 ppm MW-1
Five of the wells sampled by the GWTF (MW-4, 8, 11, 42
and 50) were grouped as wells with generally low chloride
concentrations by the statistical analysis. However, the
more recent GWTF results (relative to IT's data used for
statistical analysis) indicate that these wells show at least
one indicator parameter or heavy metal value above background
concentrations. In addition, MW-11, showed positive results
for volatile organics (as it was discussed earlier).
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Surface Water and Soil Sampling Results;
Six surface water (seep) samples were collected at the
vicinity of the site, outside of the waste management area.
Two seeps (#1 and #2) were collected in the quarry approximately
1800 feet east of the facility. Seep #3 was taken from a
tributary northwest of seep #2 approximately 1000 feet away.
Seep #4 was taken roughly 1000 feet downgradient from MW-22.
Seep #5 was collected 250 feet west of MW-4 in a tributary,
and seep #6 was collected from a tributary north of MW-4,
roughly .JL 2 00 feet away.
Samples from the seeps indicated some concentrations
for indicator parameters (e.g., chloride up to 360 ppm), and
metals (e.g., aluminum up to 55 ppm, chromium up to 0.054 ppm).
At one location (seep 15) 0.36 ppm of Bis(2-Ethyl-hexyl)
phthalate was detected also. However, due to lack of back-
ground upgradient surface water data, no conclusion about
contamination can be reached from this data.
Three soil samples' (two duplicates and one attempted
background sample) were collected from one location, in
a tributary, approximately 340 feet east of the eastern
facility fence where monitoring well's MW-27, MW-47 and
MW-5 are located.
The duplicate soil samples indicated some levels
of volatile organics (e.g., 2 butanone:0.014 ppm, and
toluene: 0.007 ppm). The GWTF attempted to collect a back-
ground sample, which was found to contain measurable levels
of total xylene (0.169 ppm), ethyl benzene (0.066 ppm) and
other organics. Therefore, it could not be used as a
background sample. The soil samples also indicated some
level of concentrations for metals (e.g., aluminum up
to 17.2 ppm, barium up to 0.341 ppm).
In general, adequate assessment of the seep and soil
sampling data, obtained by HWGWTF, is not possible due to
having only one sample data point, and lack of background
data. Therefore no definite conclusions regarding contami-
nation can be made. However, due to the detection of
pollutants in both the soil and surface water seeps, a
surface water and soil sampling investigation is needed
at the areas where seeps and soil samples were collected
by the GWTF.
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2. Compliance with §265 and §264 (40 C.F.R.)
2.1 Evaluation of Construction of Monitoring Wells;
The results of the GWTF investigation indicate that the
majority of existing monitoring wells at the Panoche Facility
are constructed properly. However, there are several wells
at which design adequacy needs to be further investigated.
Several of the., monitoring wells produced high to very high
turbid ground water samples. These wells are: MW-4, MW-7,
MW-11, MW-14, MW-22, MW-25, MW-29, MW-31, MW-47, and MW-49.
These wells need to be redeveloped and if the turbidity is
due to improper construction, they should be replaced. The
following monitoring wells need to be replaced because of
inadequate construction: MW-17 and MW-18 south of ponds 12
through 13A, and MW-15 which is located at the southwest
corner of pond 17.
2.2 Evaluation of Detection and Assessment Monitoring;
Evaluation of the facility's detection and assessment
ground water monitoring indicates that additional wells at
the compliance points (§264.99(b) 40 C.F.R.) and downgradient
from the waste management units are needed. The major
deficiencies of the assessment and detection monitoring
systems are:
* lack of sufficient and adequate shallow wells with
appropriate screen intervals for detection of volatile
organics,
* lack of sufficient wells to effectively monitor all
the possible flow paths (relatively extensive faults
and fractures),
* lack of sufficient wells at several locations,
specifically south of ponds 1 and 2, south of pond 2B
and west of ponds 12 through 13A, to monitor the full
length of the aquifer, and
* lack of sufficient wells to determine the rate and
extent of the plumes (vertically and horizontally)
within reasonable time period and to accurately define
waste constituents in ground water.
Therefore, it is necessary to expand on the existing
assessment monitoring systems throughout the facility and
also include two additional areas to the assessment program.
One area is south of pond 8 series (SB-4 cluster) where
evidence of organic vapors (20-30 ppm) in the deepest piezo-
meter (SB-4A, 271 feet deep) have been detected by photovac
organic vapor analyser while taking water level measurements.
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This could be indicative of contaminant migration down into
the deep unweathered bedrock. The facility should investigate
the area and confirm the air monitoring results (at the
well heads) performed by the GWTF. If the results are
positive, the facility should submit plans regarding the
installation of assessment monitoring wells, and geologic/
hydrogeologic investigation of the area (including fault II).
The other area is the upper drying area 61 located at the
facility boundary southeast of ponds 0, P, and Q. This
diked waste management unit was used for the dewatering of
waste sludges. Several wells downgradient, east southeast
and souih of this unit are contaminated. These wells are
MW-47, MW-27, and MW-4S. Unit 61 has not been addressed
by the facility in their assessment program. Therefore, EPA
is requesting these two areas to be added to the existing
assessment monitoring plans at the site.
The expansion of the overall assessment monitoring,
requested by EPA, asks for installment of several additional
monitoring wells at the contaminated areas. These areas are
south, southwest, west and northwest of ponds 12 through 16;
east of ponds O, P, Q; east, southeast and south of upper
drying area 61; south of ponds 1, 2 and rainwater collection
pond 2B; and south of pond 8 series.
Rain water collection pond 2B is located at the southern
part of the facility in a drainage area where most of the
ground water discharges. As the ground water discharges
into the central and south-central part of the site, it
becomes contaminated due to contact with sludges that exist
beneath the area. Some of this contaminated ground water
might be discharging into pond 2B (a non-RCRA unit).
Therefore, the facility with the aid of piezometers and
monitoring wells should provide vertical and horizontal flow
nets and determine whether the ground water beneath the pond
has vertically upward gradient. Also, as part of the assess-
ment program for this area, the facility should collect some
samples from the sediments and/or sludges at the bottom of
pond 2B. A complete GC/MS analysis should be performed
utilizing methods 8240 and 8250 (SW-846) for volatile and
Semi-volatile organics. EP toxicity test should also be
performed on the samples.
It should be noted that the number and location of
monitoring wells proposed by GWTF are not by any means final,
and the proposal does not imply that it will make the assess-
ment monitoring systems complete. Further along assessment
program there might be a need for additional monitoring wells
in order to be able to fully define the periphery of the plumes.
The proposed locations and screen intervals are chosen primarily
based on complex and extensive faulting and folding structures
at the facility/proximities, and lack of adequate and effective
ground water monitoring in specific areas.
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2.3 Evaluation of Upgradient Background Wells;
The only acceptable upgradient background well is MW-16
which is located at the most northern part of the facility,
at the highest elevation relative to all other monitoring
wells and the waste management units.
EPA does not consider the locations of other background
wells (proposed, by the facility) to be adequate for this
purpose. These wells are MW-23, MW-22 and MW-20.
Monitoring well MW-23 is located in a depression and
natural discharge zone east-southeast, and relatively down-
gradient of the north drum burial area. MW-22 is located in
a tributary outside of the waste management area boundary and
downgradient from ponds, 0, P and Q. This well apparently
has detected the edges of the plume which has originated from
ponds 0, P, and Q. Monitoring well MW-20 (2500 feet south of
the facility) has somewhat different ground water quality
compared to MW-16, therefore it should not be used as a back-
ground well representing the ambient water quality at the
site.
It is recommended that the facility should install
additional upgradient background well(s) in the vicinity of
MW-16 or higher up the elevation. The additional upgradient
well(s) could be screened in weathered and also deep
unweathered bedrock at different locations so that more
information regarding spatial and vertical variability in
ground water quality would be collected.
2.4 Ground Water Sampling and Analysis;
In order to assess fully whether annual seasonal variation
is occuring samples from all the wells should be obtained
during the months of February, April, July, October and
December. The sampling plan should be revised to include the
Appendix VIII or IX compounds so that the maximum concentration
of hazardous waste constituents at the contaminated areas be
defined.
In addition, metals, e.g., As, Cd, Cr, Cu, Pb and Zn
should be analyzed by graphite furnance techniques rather
than atomic absorption or inductively coupled plasma methods.
This will lower the detection limit and allow the introduction
of match for statistical analysis.
There are some geochemical processes which control the
mobility of certain parameters and which should be identified
in a future analysis. Anaerobic reactions, disproportionation
reactions (which may result in one product being oxidized,
the other reduced), protonation reactions (which may affect
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the PH of the ground water) and chelation reactions (which
may increase the solubility of cations through complication
with organic acids)( are reactions which will tend to enhance
metal solubility. In addition, previous studies (Baedecker
and Back, 1979) have shown that acetic acid can contribute
a significant proportion of the alkalinity (as organic acid
anions). Therefore, the alkalinity of ground water at the
facility should be included in future statistical comparisions
and acetic acid analyzed in future sampling rounds. The mean
alkalinity (414 ppm) is significantly higher than that found
in MW-16 (367 ppm). Also, turbidity for all wells should be
measured during each sampling phase.
The levels of concentrations of contaminants and hazardous
waste constituents should be defined at the compliance points,
and at the points of exposures (for contaminations outside
of the facility boundary). Appendix VIII or IX compounds
will be sampled twice a year, during dry and wet seasons, for
3 years. The water levels for all the monitoring wells and
piezometers should be recorded during every sampling phase,
and the depth of wells should be sounded and recorded.
3. "Additional Information Requirements, $270 (40 C.F.R.)
3.1 Hydrogeologic Characterization
There are several areas at the fault zones where further
investigations are needed since not enough data exist to
identify the nature of these fault zones, their relationship
with the waste management units and their hydrogeological
characteristics.
One area of concern is the fault which apparently inter-
sects both'faults I (previously fault A) and VI (previously
fault H), trends in an east-westerly direction, traversing
through pond Q and continues along the drainage east-northeast
of the facility, toward the Green Valley Fault. Monitoring
well MW-22, which has shown evidence of contamination, apparently
is located at or very close to the fault plane. Higher up
in elevation along the trend of this fault, approximately
400 feet east of 'pond Q, trench 79 is excavated. Log of
trench 79 indicates numerous short and discontinuous fractures
in alluvium/colluvium deposits of Holocene age immediately
above a sheared and fractured zone in bedrock. The origin of
these fractures needs to be explained to see whether they are
related to the displacement or shearing of bedrock. Also,
information regarding the hydraulic properties of this fault
is needed.
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Ldg of trench 43, approximately 300 feet northwest of
the north drum burial area indicates that the Domengine
Sandstone (pre-Quaternary of Eocene age), is deposited on
top of the residual soil mantle deposit. The residual soil
horizons at the site are usually dated as late Quaternary
(Holocene age), and mapped as units deposited on top of the
Holocene and early Quaternary alluvium deposits. Assuming
this specific soil horizon is the oldest relative to other
soil mantle deposits and of early Quaternary (approximately
2 m.y. old), the existance of the Domengine Sandstone (approx-
imately 45 m.y. old) on top of this soil horizon needs to
be explained by the facility. Since fault I passes beneath
the north drum burial area, and trench 43 is in the vicinity
of this fault, the facility should under more scrutiny,
investigate the fault zone, its hydraulic properties, and the
stratigraphy of the area by additional trechning and coring.
The other areas of concern where more investigations are
needed include:
* Suspected joint or fracture east of the facility
which apparently trends along a prominant drainage
and runs under the solid waste management unit 61;
* Southern portion of fault I in the vicinity of south
eastern boundary of the facility;
* Intersection of faults II and V, south of pond 2B,
and the fault plane and shear zone in that vincinity.
The existing data at certain locations at the site
indicate that the unweathered bedrock is hydraulically
connected to the upper weathered bedrock. Fluctuations of
the water level in deep wells (screened in unweathered bed-
rock) during wet seasons, and evidence of possible vertical
migration o£ contaminants into the unweathered bedrock (SB-4
cluster area, and ponds 12 through 13A area) reinforce this
possibility. In order to evaluate this further the facility
has proposed performing pump tests, at several locations
throughout the site. The proposed field test locations are:
* area immediately west of pond 13A (MW-35 & 36)
• area north-west of pond 14 (MW-38 & 39)
0 area south of pond 8 series (SB-4 cluster)
" area east of pond 1 (SB-5 cluster)
* area east of pond 2B dam (SB-3 cluster)
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In addition to the above locations, EPA is requesting
the facility to add two other locations to the pump test
program (including installation of two new deep wells).
These locations are:
0 area east of ponds 0, P, and Q (MW-50,51, and new
deep well)
0 area south of ponds 1 and 2 (MW-24,46, and new
deep well)
Also, at the locations proposed by the facility, EPA is
requesting the addition of some of the existing and new wells
to the pump tests; these additions are:
• new shallow well in the vicinity of MW-35,36
* monitoring well MW-10 and new shallow well, close to
SB-8, in the vicinity of MW-38, 39
* monitoring well MW-41 in-the vicinity of SB-5.
4. Compliance with Superfund Off-Site Policy;
The key provisions of the off-site policy require that:
* A facility chosen to receive hazardous substances
from CERCLA removal and remedial action, must not
have any significant violations or other physical
conditions which may pose a significant threat to
human health and the environment.
* A facility with significant violations or problems
may receive CERCLA waste only if the EPA or the'State
has a compliance agreement in place with the facility
tp correct all deficiencies and the unit used does
not cause or contribute to significant problems at
the facility.
* Land disposal facilities either: (1) meet the minimum
technical requirements (e.g., double liner etc.)
established by the Hazardous and Solid Waste Amendments
(HSWA) Of the 1984, or (2) establish that disposal in
the existing land disposal unit is protective of human
health and the environment.
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Farthermore, based on new provisions of Superfund Amend-
ments and Reauthorization Act of 1986 (SARA), CERCLA wastes
may be transfered to a land disposal facility only if the U.S.
EPA and the State determine that both of the following require-
ments are met:
8 The unit to which the hazardous substance or pollutant
or contaminant is transfered is not releasing any
hazardous waste, or constituent thereof, into the
ground water, surface water or soil.
* "All such releases from other units at the facility
are being controlled by a corrective action program
approved by the Administrator under Subtitle C of the
Solid Waste Disposal Act.
Based upon EPA's evaluation of available information,
IT Panoche facility is currently ineligible to receive wastes
for land disposal from response actions taken under CERCLA.
The facility fails to meet the above provisions according to
EPA's records (i.e. permit applications, enforcement actions,
inspection reports, and ground water monitoring data) and
results of HWGWTF investigaiton.
5. Facility Sampling and Laboratory Audits
5.1 Results of HWGWTF Sampling Audit;
The following are HWGWTF recommendations regarding the
inadequacies of facility's routine sampling procedures and
protocols:
* Field notes should identify all values used to
calculate purge volumes.
* The electrical water level sounders should be
calibrated on a regular basis.
* Well depth should be measured prior to purge on all
wells where there may be a silting problem.
* Braided ropes and cables used to raise and lower the
pumps and bailers can not be properly decontaminated
between wells. They should be used one time only or
replaced with a cable which can be adequately cleaned.
* The silicon tubing used in the bladder pumps should
be more carefully cut and placed on the pumps.
• Samples should be collected at the screened interval
whether the sample is collected with a pump or a
bailer.
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* The volatile parameters should be collected as soon
"as possible after the completion of the purge to
minimize the loss due to volatilization.
• Extractable organic samples should be collected in
amber bottles to minimize the effects of sunlight.
• TOG and TOX samples should be collected in separate
containers.
0 ^28203 should not be used as a preservative in any
of the organic samples collected at this site.
* The laboratories doing coliform and Cr+6 analyses for
IT Panoche should document date and time when the
analyses are initiated and completed. Chain-of-
custody should be documented for the coliform which
are transferred from one lab to another.
5.2 Results of HWGWTF Laboratory Audits
IT Analytical Services
The laboratory generally has a number of QA/QC areas
which need to be modified or improved upon. Although none
of these areas will singularly jeopardize the quality of
data generated by the laboratory, it is conceivable that,
in combination, they can cause significant problems. It
is therefore strongly recommended that these concerns be
addressed and corrected at the earliest opportunity. First
and foremost, laboratory management must finalize and imple-
ment their QA plan. Second, the laboratory should accelerate
its development of a centralized computer program, and develop
QC data acceptance limits. Lastly, documentation of records
needs to be maintained and reviewed. In summary/ if the
laboratory continues to maintain its current standard of
operation, positive attitude, and initiates the recommended
corrective action, it is expected that the laboratory can
satisfactorily analyze groundwater samples and generate data
of acceptable quality.
IT Vinehill Laboratory;
The focus of this audit was to ascertain whether the
IT Vinehill Laboratory has been conducting pre-disposal
analyses correctly, and to determine if data generated for
the IT Panoche facility is of adequate quality. In these
terms, it is felt that this laboratory has the appropriate
instrumentation, adequate facilities and qualified personnel
to satisfactorily conduct pre-disposal analyses. With the
exception of certain deficiencies, the laboratory generally
'utilizes the correct analytical procedures for pre-disposal
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analyses. Conceptually, the QA program is appropriately
comprehensive and quite detailed. However, although the
laboratory is organizationally stable and has established
a technically sound foundation, it is apparent that a number
of deficient areas need to be addressed. Specifically,
management needs to better diseminate their technical exper-
tise and QA philosophy to all laboratory staff. Also,
there appears to be a lack of consistency in the manner
the laboratory.conducts pre-disposal analyses versus truck
receiving analyses. This was clearly apparent based on the
discrepancies in truck receiving analyses summarized in EPA's
NEIC RCRA Compliance Inspection Report (Sept. 1986). Lastly,
greater emphasis has to be placed on ensuring that proper
documentation is maintained throughout each facet of analyses,
If discrepancies are noted, the laboratory should establish
a mechanism to either resolve these differences, or have a
system to substantiate the rationale for supporting these
discrepancies.
IT Panoche Fingerprinting Laboratory;
Despite the relatively small scale of operation existing
at the IT Panoche facility, there still exists a very
good standard of work performed by the staff chemist at
the laboratory. The profiles of waste currently deemed
acceptable for disposal at the site are well defined by IT,
therefore it is an unusual occurance for the laboratory to
receive a waste load which cannot be adequately characterized.
General laboratory practices are acceptable and staff are
well experienced. Based upon the findings of this audit,
fingerprinting data generated by this laboratory is expected
to be satisfactory specifically for the type of wasteloads
presently accepted at the site. However, should the quantity
and profile of future wasteloads increase or change as a
result of expanded disposal capacity at this site, then the
lab should be re-evaluated for any new additional screening
analyses. In addition, these modifications should be
adequately and appropriately reflected in a revised waste
analyses plan.
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II. DATA REVIEW
A. ,Site Description and Adjacent Water/Land Use
The Panoche Facility is situated two miles northeast of
the City of Benicia in Solano County (Figure 1). The facility,
which lies within an unnamed drainage, is located in a north-
west trending range of hills northwest of a tidal flat area
along Suisun Bay. Thick deposits of marine sedimentary rock
units underlie the facility.
Elevations at the Panoche Facility range from about 250
feet in, the bottom of the valley along the southern boundary to
about 840 feet along the northern boundary. Over 2,000 acres
surrounding the facility owned by IT Corporation. About 250
acres of the site are under interim status as a TSDF, but only
150 acres are being used for treatment, storage, and disposal
of hazardous waste.
The site occupies parts of three small drainage basins.
These basins are: The Paddy Creek Basin to the West, the lower
Sulphur Springs Creek Basin to the South, and the Goodyear
Slough Basin to the north and east. For the location of bene-
ficial water use and developed springs refer to Figure 1 (for
more information also see Table 1). The western part of the site
drains into Paddy Creek, which joins Sulphur Springs Creek below
the outlet of Lake Herman, and eventually discharges into the
Suisun Bay. Lake Herman which is located a little over a mile
southwest of the site boundary is part of the Upper Sulphur
Spring Creek Basin and is a backup water supply for Benicia.
The area receives about 17 inches of rain a year, and the
potential evaporation rate is about 66 inches per year.
Surface water flow is directly related to seasonal
variation in precipitation. The wet season usually extends
from November through March, and the remainder of the year is
generally dry.
Current and past water uses within about one mile of the
site include domestic water supply, range for live stock, and
quarrying. Surface water and ground water also support native
vegetation and wet lands. One mile of the site the total
domestic use is about one acre-foot per year (supplement to
Part B permit application) There is one user in Paddy Creek
Basin, and three houses and one stock well in Goodyear Slough.
There are no known users in Lower Sulphur Springs Creek.
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B. Waste-Management Units and Facility Operations
1. Background
The IT Panoche Facility consists of over two thousand
(2000) acres, which only 150 acres are being used for waste
management practices under interim status. The site consists
of solar evaporation ponds, ponds for neutralization, waste
piles, landfill and storage containers. The facility is
operating as a Class I waste disposal site under an interim
status document issued by CA DOHS under Section 25200.5 of the
California Health and Safety Code. Prior land use in this area
was livestock grazing. In 1968 the J&J Company began using the
land for waste disposal, and in 1974 IT Corporation acquired
the site.
When the initial RCRA permit application was filed
(August 8, 1983), the facility had forty-four (44) surface
impoundments, a landfill, three waste pile areas, and two land
spray areas. During the period of 1984 to present, most of
the ponds have been taken out of service and several have been
lined (Ponds 0 and P).
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2. Wastes Managed by the Facility
The table below lists the types and the amount of waste
which were handled from 1980-1985, in 1000's of tons:
Waste Group 1980 1981 1982 1983 1984 1985
Acids and Alkalines 45.8 37.2 18.9 17.3 18.3 17.1
Oily Wastes,'Floes, Paint 15.9 30.5 10.4 4.4 3.8 8.4
Pesticides 0 16.9 19.0 000
Heavy .Metal Sludges 9.4 14.5 2.0 10.1 11.3 16.2
Contaminated Soils 17.1 18.7 24.3 54.1 62.2 73.7
Other 7.9 6.7 9.1 57.3 120.1 53.9
Totals 96.2 124.5 83.7 143.2 215.7 169.3
The specific types of hazardous waste handled by IT Panoche
facility included Acid solutions with/without metals, alkaline
solutions with/without metals, aqueous solutions with organic
residues, metal sludges, spent catalyst organic and inorganic
solid wastes, halogenated and hydrocarbon solvents, waste and
mixed oil, pesticide rinse water, tank bottom and still bottom
wastes, polychlorinated biphenyls and material containing
PCB's, organic liquids/solids with halogens, organic liquids
with metals, phosphate and sulfer sludges, paint sludge, sewage
sludge, tetraethyl lead sludge, laboratory waste chemicals,
degreasing sludge, fly ash and bottom ash, bag house waste, gas
scrubber waste, empty pesticide containers, polymeric waste and
organic monomer waste. IT Panoche facility has also taken soil
contaminated with heavy metals, (e.g. lead, arsenic, copper,
cadmium), from superfund sites.
Solid wastes were disposed directly into the landfill, and
surface impoundments were normally used for solar evaporation,
infiltration and concentration of liquid wastes. According to
the facility, sometimes during extreme drying conditions such
as a high pressure system built up over the Great Basin area,
some liquids were discharged onto landfill or land treatment
areas which according to IT provided moisture to aid in main-
taining soil texture and compaction, as well as dust control.
The facility also asserts that liquid wastes that were dis-
charged into the landfill or land application areas were
"immediately" upon discharge mixed with "clay material" to
render them able to pass the free liquid test for hazardous
waste landfills.
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3. Surface Impoundments
None of the surface impoundments at the facility are lined,
except for ponds 0 and P. The only active surface impoundments,
which are accepting wastes are ponds 0, P, and ponds 17 and 18.
Ponds 0 and P (1,2,3) are retrofitted and are composed
of two linings consisting of an upper synthetic liner and a
lower composi-te synthetic/clay liner. A leak detection layer
is located between the two liners. All pond bottoms have
possitive drainage to the leak detection sumps. The types of
waste-disposed at these ponds are Titanium Oxide Acid waste,
which are produced as a result of paint pigment production.
Ponds 17 and 18 previously have received oil refinary
and petrochemical wastes, drilling muds and sewage sludges.
Pond 17 currently is used as a truck wash out area and pond
18 receives sludges that do not pass the paint filter tests.
Since November 1985 no surface impoundment has received
any off site waste (except 0, P, Q and 17, 18). All the other
ponds have been taken out of service, and are either capped or
they are in the process of stabilization and solidification.
Ponds 12-16 were dried, and according to the faci.lity, contami-
nated materials were excavated and disposed of in the landfill.
The ponds were then filled with local borrow material. The
other ponds, 4,5,6 and 19 series located in the central area,
were also stabilized, dried and then contaminated material were
disposed of in the landfill. The rest of the ponds south and
southwest of central area (1-3 and 7-11) and pond Q north-east
of the facility are in the process of stabilization and
solidification.
All the primary surface impoundments (ponds 12-18, and
0, P, Q) were designed to cascade by piping system to a series
of lower ponds which allowed the operator to maintain the
required pond freeboard and also served to increase the
surface area of liquid for solar evaporations. Due to this
cascading system there are no records of liquid waste transfer
from pond to pond.
There is also a final containment pond (pond 2B), which
is used to store stormwater runoff from non-disposal areas
within the site and also used to contain accidental spills
and overflows from waste ponds. This pond is located at the
southern end of the site in the main drainage basin south of
central area. An earth dam which its core is Keyed into the
bedrock contains this pond. The discharge of treated water
from pond 2B is covered under NPDES permit.
4. Landfills
Landfill areas include the "area 5" landfill whicn
occupies approximately 15 acres, and former landfill area
located south of pond 17 that was closed in October 1980
(approximately 5 acres).
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The area 5 landfill which was the only active unit for
receiving solids after October 1980, ceased accepting waste on
July 4th 1986. The Part A application submittals of November
1981 identifies the design capacity of the landfill to be 300
acre/ft. The revised Part A submitted the same year included
the future expansion of 12000 acre/ft. In the report of waste
discharge submitted in September 1985, the reported capacity
was 520 acre/ft and 12000 acre/ft (future expansion). In late
July 1986 IT met with CADHS regarding exceeding the allowed
design capacity and informed the agency that they have stopped
accepting waste for landfill disposal as of July 4th 1986.
The types of hazardous wastes accepted for landfill
disposal during the active period of the unit included solid
hazardous waste from industrial sources, de-watered sludges
from the bio-area, contaminated soils (including CERCLA
wastes), and contaminated sludges. There are no discrete
landfill cells, solid wastes were mixed with soil and applied
over the entire working face rather than deposited directly
into cells and covered. Run-on from the upper portions of the
canyon is diverted away from the landfill by a drainage channel
constructed at the northern limit of the waste disposal area.
Stormwater run-on is diverted to a side canyon and is impounded
in a stormwater retention pond (pond T).-A stormwater reten-
tion pond (pond N) is also maintained in the upper canyon
(designated N-Canyon). Run-off from active portions of the
landfill is collected in a subdrain system that previously
discharged to pond 6 series. From the time those ponds were
out of service, contact water is being directed to ponds 1
and LA.
5. Bio- Areas
There are seven disposal areas designated as bio-areas
1, 2, 3, 8, 13A, bio-spray area and upper drying area (area
61). Bio-area 1, was cleaned in 1983 and has not been used
since then. Liquids from pond 1 (contact water) were pumped
to a sprinkler system in the bio-spray area located in the
central area.
The bio-areas were diked and used for the dewatering of
waste sludges. Wet sludges from the petroleum refining indus-
try and sludges excavated from on-site ponds were deposited
inside the disposal areas, graded to promote drainage of free
liquids and allowed to dry prior to landfilling. Run-off from
sludges were collected in downslope collection sumps. The bio-
areas, should not be considered as land treatment areas, since
the reported function of these areas is to reduce the volume
of free liquids in the waste and not to make the waste less
hazardous or non-hazardous by biological degradation. According
to the facility, none of these bio-areas have been active since
late 1985.
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6. Waste Pile
Waste handling practices included the deposition of
waste material at a pre-designated unloading area. A waste
load received at the landfill site was mixed with previously
deposited waste material. The comingling of two or more
incompatible waste streams and not having adequate control on
the separation of these wastes had caused several incidents of
fires in the-waste pile area. One stock pile area (designated
17 p) is located at the former landfill area south of pond 17,
and has not received any waste since March 1986. The other
waste"pile areas (Q, P and PI) are currently used for drying
acid neutralization sludge/solid associated with ponds O and P.
7. Drum Burial Areas
There are five (5) closed drum burial areas at the facil-
ity. One area is located about 200 feet northwest of pond 18,
and is covered with top soil and vegetation. The other burial
cell areas are scattered throughout the site. One area is
south of pond 17 (from landfill) which is capped. One area is
adjacent to the area 5 landfill and pond 18. Another burial
area is located to the west of pond 1A (central area), and. one
is situated about 200 ft north of pond P. Approximately 4000
drums, are buried in 19 trenches at these burial areas.
For a detailed map and the location ot all the hazardous
waste management units see figure 2.
8. Current Status of Operations at the Facility
Currently the facility is involved in major technical
investigations regarding the landfill expansion project and
assessment of the drum burial areas.
8.1 Landfill Expansion
The proposed landfill will cover an area of 118 acres
and have a total volume of 20,070,000 cubic yards (12,440
acre-feet), including liners, leachate collection system, and
closure cover. It is anticipated that this configuration will
be achieved in approximately 35 years based on annual receipts
of 540,000 cubic yards. The foundation system will consist of
two major portions: bottom and slope, the liner system at
the "bottom" portion will consist of a minimum of 2 feet of
clay (permeability of 1x10-7 or lower) covered with secondary
synthetic liner, leak detection system, primary synthetic
liner, leachate collection system, geotextile and final soil
cover (minimum 6"), respectively. The liner system on side
"slopes" steeper than 3H:1V will consist of synthetic, and clay
liner with no leachate or leakage collection layers (slopes
less steep than 3H:1V will have the leachate collection system)
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The runoff control system in the expanding landfill will
be network of ditches which will collect water from each land-
fill bench. The system will divert water off the landfill and
will be discharged into either a retention pond or a natural
drainage channel. Runoff water from active areas of the
landfill will be discharged into pond 1 down gradient of the
landfill area.
The modified run-on control is a diversion-system which
should prevent surface water from the surrounding hillsides
from running onto the landfill. Water will be intercepted by
ditches and lined channels and divert laterally to discharge
into pond T. Pond N will be used as storage for reducing the
peak of the hydrograph. Following storms, the water in pond N
will be pumped out to the channel leading to pond T using
portable pumps.
The proposed landfill expansion will ultimately fill the site
to an elevation of approximately 640 feet. The foundation
including all the liner and drainage control systems will be
constructed on top of the bedrock, alluvium/colluvium, and
artificial fills (including waste), depending on the different
locations at the central area.
The physical setting of the landfill (as it was mentioned
earlier) is at the discharge area in the valley. Therefore, it
is recommended that the facility should consider and evaluate
the diversion of ground water in the N Canyon and along the
northern limits of the landfill. This diversion (e.g. cutoff
wall and drainage by gravity) will reduce the amount of ground
water discharge beneath the central area (future landfill)
considerably. This will reduce the amount of contaminated
ground water (by contact with sludge beneath the central area)
which has to be collected by the cutoff/collection trench,
proposed by the facility, north of pond 2B.
The other major component of the expansion^project is the
treatment/stabilization unit, and water management system.
The purpose of the treatment/stabilization unit is to pretreat
wastes prior to landfill disposal. The unit will treat and
stabilize both liquid and solid waste receipts by mixing waste
with neutralizing and stabilizing agents, such as lime, kiln
dust, and cement. The water management system will divert,
collect, convey and manage water originating as rainfall and
water used to decontaminate equipment. The system involves
drainage and sediment control structures and will consist
of collection sumps, storage tanks, surface impoundments
for storing water, or solar evaporation unit, and a water
treatment system. For the plan of the proposed facilities
and the project cross-section, see figures 3 and 4.
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"Eventually, the project construction will place the onsite
waste into the landfill. The following table identifies the
disposition of existing waste management units:
Waste Management
Units
61, 0, P, PI, P2, P3
Q, QP
1, 1A, 2, Bio2, 3,
Bio3, "4, 5, 6, LA,
6B, 6C, 7, 8, 8A,
8B, Bio8, 9, 9r, 10,
lOr, 11, llr, 16,
19, 19A, 19B, 19C,
19D, 20, 21, 22.
Area 5, 17, 17P, 18
Disposition
Closed by waste management unit
removal and disposal in lined
landfill.
Existing facilities removed and
retrofitted. Removed waste
disposed on lined landfill.
Closed in place.
The following table identifies the current waste manage-
ment units expected to continue in active operation pending
permits:
Waste Management
Unit ;_
Treatment Units;
* pH adjustment and Acid
neutralization units,
Baker tanks.
* Carbon treatment unit,
Baker tanks.
Surface Impoundments:
• Ponds 1, 1A, 2, 8, 17,
18 and Q.
Ponds O, P, Pl-3
Use
Waste Pile:
Waste pile QP
Storage, neutralization, metals
precipitation of acidic liquid/
sludges.
Storage and treatment of
potentially contaminated water.
Receipt of sludge waste and intra-
site transfer of sludge and liquid
waste; receipt of truck washout
water and contact water.
Receipt of liquid acid waste/-
receipt of sludge waste and intra-
site transfer of sludge and liquid
waste; receipt of truck washout
water and contact water.
Drying and stockpiling acid
neutralization sludge/solids
associated with Ponds 0 and P.
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Landrill;
0 Area 5 Disposal of solid waste.
8.2 Drum Burial Area Assessment
The facility has completed the preliminary assessment of
possible remedial actions regarding the five drum burial areas
at the site. ..The investigation weighs and compares the feas-
ability and risks involved in excavation and removal, and a no
action alternative which suggests the drums should stay buried.
Further investigations are underway and the regulatory agencies
are reviewing and deciding on possible remedial actions.
C. Site Physiographic Setting, Topography
The regional physiographic setting for the Panoche Faci-
lity includes the Coast Ranges and Great Valley of California
physiographic provinces (Figure 5). The Panoche Facility lies
entirely within the Coast Ranges province while the western
limit of the Great Valley province lies about 2 miles east of
the facility.
in the region of the facility the Coast Ranges Province is
about 50 miles wide. The province consist of a group ot nearly
parallel, northwest trending mountains, ranging in elevation
from 2,000 to 4,000 feet, with intervening valleys. Topography
rises abruptly at the western limits, with steep cliffs and
narrow wave-cut terraces along the coast. On the eastern limits,
the border with the Great Valley is also relatively abrupt. The
Suisun, San Pablo, and San Francisco Days are also prominent
features in the region of the Panoche Facility.
The Graat Valley of California Physiographic Province is
located directly east of the Coast Range, its western limit
being just east of the Panoche Facility. The northwest trending
valley is about 400 miles long from north to south and averages
about 50 miles in width. In the region of the facility the
Great Valley has elevations that range from sea level to less
than 400 feet and the valley surface general slopes towards
San Francisco Bay from the north, east, and south.
The group of low, northwesterly trending hills immediately
west and north of Suisun Bay defines the area for the site
vicinity. The western two-thirds of the site vicinity is
characterized by small hills, or low mountains, and intervening
valleys. Elevations in the vicinity range trom near sea level
in the area of Suisun Bay and Carquinez Straits to about 1,100
feet in the hills about 2 miles north of the Panoche Facility,
while more local relief is on the order of 500 to 600 feet.
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The eastern one-third of the vicinity is essentially flat lying,
occupied by Suisun and Grizzly Bays and their surrounding swamp
and salt water marshes, and elevations are near sea level.
Drainage pattern varies over the upland portion of the
site vicinity. The southwest flowing Paddy Creek drains the
vicinity at the western side of the Panoche Facility, and
joins the Sulphur Springs Creek drainage system downstream from
Lake Herman. 'The area to the north and east of the Panoche
Facility drains primarily east and northeast to the swampy
lowlands adjacent to Suisun Bay. Except tor the western-most
portion of the Panoche Facility that drains into Paddy Creek,
drainage from the facility is included with these eastern
drainage to Suisun Bay.
D. Site Geologic/Hydrogeologic, and Structural Settings
1. Geological Setting
The site, as mentioned earlier, is located at the head-
waters of an unnamed drainage valley which trends south-
easterly for about one and one half miles to the tidal flat
area of Suisun Bay. Elevations within the facility range
from 250 feet at the bottom of the valley to 840 feet along
the north property boundary. The surrounding terrain is
hilly with slope gradients locally as iiigh as 42 percent.
Prior to start of development of the Panoche facility
in 1968, the area was covered by a soil mantle supporting
a grassy vegetation. Natural bedrock exposures are found
only in some parts of intermittent stream channel bottoms
and along the tops of hills were resistant sandstone beds
are sometimes exposed. Geologic materials at the site are
divided into two major categories:
(1) Pre-Quaternary Units, and
(2) Quaternary deposits.
Two pre-Quaternary bedrock units are found at the site;
the Panoche Formation of Late Cretaceous age and the younger
Domengine Sandstone of Eocene age. The majority of the site
is underlain by the Panoche Formation, and a small area of
the facility, chiefly to the higher elevation, in the
northern part, is underlain by the Domengine Sandstone.
The Domengine Sandstone consists of very thickly
bedded to massive, uncemented, relatively clean, fine
grained quartz rich sand. The color is commonly white with
yellowish iron staining along fractures and joints. The
base of Domengine Sandstone is marked by thin interbed,
of greenish gray tuffaceous shale and carbonate cemented
sandstone containing oyster shell remains, indicating a
-------
-27-
mudh shallower marine environment than Panoche Formation.
The Domengine Sandstone overlies the Panoche formation.
The contact between the two formations forms an angular
unconformity, which indicates that the Domengine Sandstone
was deposited after deposition, deformation and folding of
the Panoche Formation. The Domengine Sandstone that may
have existed in the area of the facility largely has been
removed by erosion. It occurs as isolated outliers at
the higher- elevations at the facility, and it has not been
explored in the facility region. Also, its waterbearing
characteristics have not been investigated in detail.
The Panoche Formation consists of interbedded shales,
mudstones, siltstones, sandstones, and lenses of conglom-
erate that were deposited in a marine sedimentary basin.
Thickness of this formation has been estimated as 20,000
feet (Bishop, 1970) to 25,000 feet (Payne, 1962) in two
areas southwest of the site vicinity. On a regional scale,
the Panoche Formation has notable lateral variations in
lithology, caused by facies changes and topographic irregu-
larities within the depositional basin, induced by regres-
sions and transgressions of the late Cretaceous sea.
At the facility, weathering affects the Panoche For-
mation to a depth of 20 to 50 feet below the top ot the
bedrock. The severely weathered shale and shaly siltstones,
cored at the facility, typically exhibit heavy spheroidal
and concoidal fracturing and iron oxide staining. Panoche
Formation Sandstones also exhibit heavy iron oxide staining
locally. The weathered portions of the bedrock also are
characterized by open joint and bedding planes. Below about
40 to 50 feet, the majority of the rock is fresh. In some
places, the contact between weathered and unweathered rock
is abrupt but in many cases it occurs as a transition over
several feet.
Three types of Quaternary deposits are found in the
study area: Alluvium, mass movement deposits, and a resi-
dual soil mantle.
Alluvium is deposited primarily in the bottom of the
main drainage valleys. The alluvium consists of sandy clays
and silts with variable thicknesses of silty gravels with
cobbles at the base of the deposit. Quaternary alluvium was
found in the upper parts of MW-1,2B, 28, and 29 with thick-
nesses ranging from 2 1/2 to 20 feet.
Several mass movement deposits are mapped at the vicinity
of the facility boundry. These mass movements are identi-
fied on the basis of analyzing new sets of color and color
infrared aerial photographs and interpretation of the
preexisting subsurface data. Trench logs of some ot
-------
-28-
the landslide area exhibit slope parallel shear planes and
irregular bedding attitudes and shear patterns which are
indications of mass movements. Also at some of the areas
(areas underlying MW-17, MW-18, MW-19, MW-13, MW-26, and
MW-31) landslides are located above the fault zones (see
Figure 6). The fault zones are recognizable in boring and
trench logs by clay gouged zones and almost vertically
dipping bedding close to these zones. It is not clear
wheather -these landslides are triggered by the movement
along the faults or due to excess weight of weathered
material which exceeded its resistance to shearing (which
in--turn migh have been reduced by an accession of soil
water). Residual soil consists of highly plastic, clayey
silt and sand which grades into severely weathered bedrock.
The soil is thinnest along ridges and hill crests (one to
two feet thick) and becomes thicker at the base of slopes
or in saddles. The soil in most locations, is highly struc-
tured with prismatic soil columns produced by shrinking
and swelling of the soil during the dry and wet seasons.
The soil also contains evidence of slope-creep which is
imperceptible flow of colluvium. For geologic map and
cross sections, see figures 6 and 7A through 7E.
2. Hydrogeologic Setting
Two water bearing zones have been identified by the
facility. The principal water-bearing unit is the
weathered, uppermost zone of the Panoche Formation and in
some places, the overlying alluvium and fill. Ground water
also occurs at greater depths within the unweathered bed-
rock. The permeability tests have shown that water in this
zone is less mobile and, in terms of water storage per unit
volume of rock, comprises a much smaller supply. Field
permeability tests (packer tests) indicate that the
weathered bedrock has permeabilities in the range of 1X10-4
cm/sec to 6X10~6 cm/sec. The unweathered bedrock, depending
on interbedding and the extensiveness of the fractures, has
permeability valued ranging from < 1.8X10~5 cm/sec (shale
interbedded sandstone) to 2.2 x 10~9 cm/se c (clayey, silty
shale).
Ground water contour maps (see Figures 3 and 9)
reinforce the fact that the flow gradients in the shallow
weathered bedrock are generally parallel to the surface
topography.
The ground water contour maps generated by GWTF have
been constructed using the January and August water levels
of shallow monitoring wells and piezometers. These contour
maps indicate the approximate flow patterns during wet
(January) and dry (August) seasons. The bull's eyes on the
contour maps are probably due to mounding of the seepage due
-------
-29-
t<3- the leaking ponds. The mounding north-west of the maps
is where ponds O, P, and Q are located. The more extensive
mounding, on August contour map, is located in the central
and western part of the central area. During the wet
seasons in 1986 extremely heavy rain storms occured, Which
caused the ponds at IT Panoche to get overfilled. The
mounding seen on the map could be the reflection of the
excessive leakage of the ponds due to those rain storms.
Figure 10 snows the prominant hydrogeological divides.
These watershed boundaries influence the ground water flow
patterns which overally are in three directions. Most of
the ground water, flows through the central area and exits
the facility through the southern boundry and Pond 2B area;
the rest of the flow is toward east-southeast and west.
The watershed boundry that starts at southern most corner
of the facility and trends northeast, could be mostly
due to the fault II and partly due to the intersection of
fault II and V at southern corner of the facility (south
of Pond 2B). Figure 11 shows the elevations of top of the
unweathered bedrock beneath the facility. It is apparent
that these elevations overally follow the surface topography
which reinforces the general directions of the ground water
flow in the overlying weathered bedrock.
Ground water also occurs at deeper zones in unweathered
bedrock. The formation mainly consists of fresh clayey
matrix where the porosity is relatively high and the
specific yield is considerably low. Considering the higher
permeability values of the weathered bedrock (1 or more
orders of magnitude higher than unweathered bedrock) and
higher specific yield, most of the infiltration is being
confined to the weathered zone. However, the unweathered
Panoche Formation does yield small and large quantities of
water, mainly from fractured zones, throughout the facility.
Although these appear to be scattered zones as the explora-
tory borings indicate, hydraulic gradients at several loca-
tions (SB-4 and SB-5 clusters) between shallow and deep
piezometers, and fluctuation of water levels in deep wells
during wet seasons, indicate the unweathered bedrock might
be hydraulically connected to the weathered zone. If that
is so the unweathered bedrock is part of the uppermost
aquifer. Details of facility's proposal on determination of
base of the uppermost aquifer and fiPA's additional requests
are discussed in section E3. EPA has defined the uppermost
aquifer as the geologic formation, group of formations, or
part of a formation that is the aquifer nearest to the
ground surface and is capable of yielding a significant
amount of ground water to wells or springs (40 C.F.R.
§260.10) and may include fill material that is saturated.
If zones of saturation capable of yielding significant
amounts of water are interconnected, they all comprise the
uppermost aquifer.
-------
-30-
3. Structural Geology
..-•-•- As discussed earlier ground water contours and flow
gradients in the shallow weathered bedrock, are generally
parallel to the surface topography. The ground water
movement is also influenced by the faults and other
secondary fractures at the site. Faults are important
because clayey gouge zones can serve as ground water
barriers while the fractured rock along the fault can allow
more rapid ground water movement parallel to the fault
plane. The facility has conducted investigations which
consisted of borehole sampling, trench excavations, aerial
photo interpretation and literature search, and has identi-
fied numerous faults at or near the facility boundry.
Figures 6 and 12 provide the locations of these faults and
secondary fractures at the facility and their regional
settings. Six fault zones and their associated fractures
have been identified at the facility (I through VI).
These extensive faults are generally parallel to the Green
Valley Fault which its strike trends North-Northwest, and
at closest distance it is about 2,000 feet from northwest
corner of the facility.
Except for Green Valley-Concord fault, the age of
movements for the six continuous faults that traverse the
Panoche Facility, and those faults within 3,000 feet of the
facility permitted boundry, have not been assessed. The
difficulty is due to not being able to establish absolute
age for landslides, alluvial, and residual soil deposits.
According to the facility, the geomorphic and topographic
expression along the traces of the faults, historic and
recorded seismicity of the region, site vicinity and
facility, and trench exposures indicate that the faults
have disrupted the bedrock materials only, and it may be
interpreted that the faults through the facility probably
have not moved during the Holocene time.
3.1 Need for Additional Fault Investigations
There are some areas at the fault zones where
further investigations are needed since not enough
data exist to identify the nature of these fault
zones, their relationship with the waste management
units and their hydrogeological characteristics.
One area of concern is the zone associated with
fault I (see Figure 12). This fault apparently
intersects both faults I (previously fault A) and VI
(previously fault H), trends in an east-westerly
direction traversing through pond Q and continues
along the drainage north east of the facility, toward
Green Valley fault. The ground water contours indi-
cate that the flow would be parallel to this fault
-------
-31-
along the drainage where well MW-22 is located.
The boring log indicates highly fractured bedrock
(sandstone), with beddings dipping 60 degrees from
horizontal. This indicates that the fault might be
very close to this well (this is important because
MW-22 has shown evidence of contamination). Higher
up in elevation along the trend of this fault,
approximately mately 400 feet east of pond Q,
trench 79 was excavated. The log at trench 79
indicates numerous short and discontinuous fractures
in alluvium/colluvium deposits of holocene age
immediately above a sheared and fractured zone in
bedrock and filled with caliche salts. The origin
of these fratures are not explained, and since they
are directly above the fractured zone in the bedrock,
they might be related to the displacement and or
shearing of bedrock, however minor (see Figure 13).
Also, information regarding the hydrological
properties of this fault is needed.
Log of trench 43 (about 300 feet northwest of
the north drum burial area) indicates that the
Domengine Sandstone (Pre-Quaternary of Eocene age)
is deposited on top of the residual soil mantle
deposit (Figure 14, D on top of C). The residual
soil horizons at the site are usually dated as late
Quaternary (Holocene age), and mapped as units
deposited on top of the Holocene and early Quaternary
alluvium deposits. Assuming this specific soil
horizon is of early Quaternary (approximately
2 m.y. old), the existance of the Domengine Sandstone
deposit (approximately 45 m.y. old) on top of this
soil horizon needs to be explained. The available
data presents some discrepencies, gaps, and problems
which should be refined and explained. Since the
contaminant plume has been detected in this area,
and the most probable flow path is the drainage area
(along the fault), the facility should (under more
scrutiny) investigate the fault zone site hydraulic
properties, and the stratigraphy of the area by
additional trenching and coring.
The other area of concern is a suspected joint
or fracture east of the facility which apparently
trends along a prominent drainage and runs under the
solid waste management unit 61. It seems that well
MW-47, which has shown higher elevations of total
metals, than background, is located very close to
this suspected fracture. The boring log from MW-47
indicates fractured weathered shale, and a fractured
plan at depth of 29.5 feet in the fresh bedrock.
-------
-32-
Besides this boring, there is no other data to
evaluate this tracture. This fracture along tne
drainage could be a pathway for migration of contami-
nants, therefore it should be further investigated.
Another area where sufficient data does not
exist is the southern portion of fault I. Trenching
or boring should be done to expose the fault if
pos.sible and to investigate its relative age of
movement. According to the facility, trench 36 has
exposed the fault north of the facility, beyond the
boundry, and no evidence of faulting being extended
into the soil mantle layer, exists. However the
southern portion of the fault has not been investi-
gated. Since this is a major fracture that traverses
the entire site through the central area, it needs to
be investigated in more detail.
The last area of concern is the intersection
at two other major faults (II and V previously B and
E) at the facility, south of pond 2B (Figure 6).
This area is the main drainage location for the
entire central area. Recharge to the fill, alluvium
and weathered bedrock flows through this drainage.
Two monitoring wells MW-14 and MW-25 are located
about 400 feet and 600 feet down gradient from the
dam respectively. Not much of information regarding
these faults is available in the boring logs at
MW-14 and MW-25. Boring log of MW-25 indicates a very
soft sandy siltstone at about 44.5 feet in tne fresh
bedrock. The static water levels and the screen
intervals indicate that there is a saturated zone of
more than 60 feet, starting in weathered bedrock (9
feet below the ground surface) and extending 45 feet
down into the slightly weathered bedrock (MW-25 is
screened from 25 to 35 feet and MW-14 is screened
from 40 to 70 feet). The boring logs do not indicate
any significant latteral lithological changes between
these two wells and the gradient of ground water is
about 0.05. No data on the hydraulic conductivity at
this area is available. Considering the extensiveness
of the aquifer at this location and the existance of
two major fractures, it is necessary to perform
permeability tests and determine the rate of ground
water movement at this area. These faults, (II and
V, south of pond 2B) should be investigated by
coring, and if applicable by trenching and to deter-
mine whether MW-14 is monitoring the fault plane.
-------
-33-
E. Ground Water Monitoring System;
Since 1984 IT has been conducting extensive geological and
hydrogeological investigations at the requests of the regulatory
agencies. The activities have generated tremendous amount of
borehole logs from some 200 exploratory drillings, installation
of piezometers and monitoring wells. Over 80 trenches have
been excavated to identify the structural geology of the site.
During the GWTF investigation there were 56 monitoring wells
throughout the site.
The following table identifies the waste management units
and the set of monitoring wells associated with those units.
Figure 2 provides the locations of all the monitoring wells and
other geotechnical and geochemical bore holes.
Monitoring Well »
Waste Management Units
Location at the Site
24, 46, 52, 25, 14*,
8, 42
1, 1A, 2, Bio2, 3, Bio3
7, 8, 8A-C, 2B
4, 5, 6, 6A-C, 9, 9R, 10
10R, 11, 11A, 11R, 19,
19A-D, 20-22, existing
landfill.
Lower Valley Area
Central Area, Terrace
and Area 5 landfill
54, 2B, 17, 28, 33,
(35-37)*
12, 13, 13A
West - Southwest
10, 34, 4, 13, 26,
31, 38*,39*, 56
14, 15, 16. 13A
West
15, 11
17, 17P, 18, previous
landfill, previous drum
burial area
North - Northwest
40-49, 50, 51, 53,
55, 5, 7, 21, 27, 22
0, P, Q, previous solid
waste management unit 61
North - Northeast,
East
* Deep monitoring wells, screened in the fresh unweathered bedrock.
-------
-34-
1. Well Design and Development/Well Information
The wells at the facility were drilled initially with
8-inch O.D. hollow stem augers and were sampled at intervals of
five feet or less. Some of the wells were reamed with 12-inch
diameter hollow stem augers before casing installation. The
casings used are 4-inch, schedule 40 pvc with flush threaded
joints.
Since the monitoring wells at the site are producing
mainly from fracture flow in the weathered/unweathered bedrock,
the standard methods for sizing the filter pack and slots were
not considered to be applicable by the facility. Therefore,
wells were constructed using a standard design which according
to the facility had been effective based on past experience.
This design has utilized 0.020-inch manufactured slotted casing
and No.3 Monterey sand. The monitoring wells, after the instal-
lation of the well casing and filter pack, were sealed by 1 to 2
feet of bentonite pellets on top of the filter pack material,
and the remainder of spacing between well casing and the bore
hole were sealed by cement grout all the way to the ground
surface. A protective steel casing with a cap and lock were
installed at the end. Figures 15 and 16 show typical shallow
and deep well construction details.
Developing the monitoring well was performed utilizing the gator
(vacuum) truck to suck monitoring well dry. For wells that did
not clear up by this process, a surge block was used to create
surging motion to develop the sand pack around the well screen,
and also where appropriate an air compressor and metal pipe were
used to bubble air through water in the screen to develop the
sand pack.
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-------
-45-
Th e following monitoring wells have been replaced by new wells:
- MW-1, plugged and replaced by MW-54 (after GWTF investiga-
tion) .
MW-2A, plugged and replaced by MW-2B.
- MW-3/ being used as a piezometer, and is replaced by MW-26.
MW-6, being used as a piezometer, and is replaced by MW-27.
- MW^12, plugged and replaced by MW-53.
MW-19, plugged, no replacement.
- MW-30, plugged, and replaced by MW-33.
- MW-32, replaced by MW-34.
- MW-45, plugged and replaced by MW-52.
IT, after a recent review of the facility's ground water monitoring
system, has proposed additional wells for replacements and/or plug-
gings which are as follow:
Wells to be plugged, without replacement: C-3, C-4, C-5, and MW-18.
Wells to be replaced and then plugged: C-l, C-2, C-6.
Wells to be replaced and retained as peizometers: MW-41, iMW-48,
MW-53, and MW-56.
The facility should submit complete detail regarding the plugging
procedures including the new list of monitoring wells which have been
abandoned.
2. Evaluation of Detection Ground Water Monitoring System.
The results of the Ground Water Task Force investigation
indicate that majority of monitoring wells at the Panoche Faci-
lity are located and constructed properly. However, there are
several wells which their design adequacy need to be further
investigated. Also several locations throughout the site need
to be investigated and new monitoring wells installed. The
following discussions bring the inadequacies and problems to
attention, and recommendations which the facility should con-
sider and undertake.
2.1 Construction Evaluation
During the GWTF sampling event, some of the wells
indicated high to very high turbidity values ranging from
6.1 NTU to 102 NTU (maximum acceptable limit is 5 MTU).
-------
-46-
The facility should utilize the decision flow chart
(Figure 3-4, RCRA Ground Water Monitoring Technical
Enforcement Guidance Document) to evaluate well construc-
tion and development. If the end result indicated that
there are no organics in the turbid ground water samples,
then the wells are constructed and/or developed impro
redevelop the wells, using appropriate method(s) and if
the problem is not solved, the wells should be replaced.
The following table identifies these wells and their
turbidity values;
-' MW-4 Turbidity, NTU 25
MW-7 " " 60
MW-11 " " 25
MW-14 " " 20
MW-22 " " 36
MW-25 " " 28
MW-29 " " 102
MW-31 " " 36
MW-47 " " 38
MW-49 " " 6.1
There are four monitoring wells (MW-17, 18, 19 and
37) south of ponds, 12, 13 and 13A which are installed
in a drainage that runs south west. MW-17 is not an
acceptable monitoring well because it has 30 feet of
screen which is hand sawn and the slip couplings are
attached by metal screws. MW-18 has a gravel pack which
extends up to two feet below the surface, and the facility
has proposed to plugg it. MW-19 was damaged and it is
abandoned. The only acceptable well in this area is MW-37
which monitors the unweathered bedrock. Therefore,
several shallow monitoring wells should be installed to
replace some of these wells. The screen intervals should
monitor the upper and lower parts of the saturated zone.
The shallower wells must be screened at the ground water
level for adequate detection of volatile organics. It
should be brought to the attention that althought contami-
nation has been detected in this area (and further down-
gradient) the replacement of these monitoring wells are
imperative for the purpose of compliance point monitoring
and hence for demonstrating the effectiveness of the
future corrective actions.
Immediately to the southwest corner of pond 17, and
the old landfill (17P), there is monitoring well, MW-15.
This well has 50 feet of screen (from 12 to 62 feet)
which monitors two different lithologies. The top 20 feet.
is consisted of interbedded silty sandstone and clayey
siltstone, and the bottom 30 feet is sandy siltstone.
The depth to water typically is about 30 feet. Such a
long well screen will not be able to detect contaminants
concentrated at a particular depth. A contaminant may
-------
-47-
.be concentrated at a particular depth because of its
physical/chemical properties, and/or hydrologic factors.
In this situation, a longer well screen can permit
excessive amounts of dilution which may prevent the
detection of statistically significant changes in indicator
parameters. The diluted concentration of contaminants may
be below detection limits of the laboratory method being
used. However, it should be noted that the fluctuating
potentiometric surfaces at the site (couple of feet) and
also the low hydraulic conductivities, some times necessi-
tates the use of longer well screens at some locations at
t-he site. However, screens more than 20 feet are too long
to adequately detect contaminants and maintain chemical
resolution vertically. Therefore, MW-15 should be
replaced by two wells.
2.2 Location Evaluation
The site, as discussed earlier, has a very complex
geology which is caused by closely spaced fractures,
faults, tight folds and variable lithologies within three
dominant facies. The hydraulic gradient and the flow
paths are highly influenced by the complex structure of
the site, the adequate monitoring system should intercept
all the potential pathways for contaminant migrations.
Considering the above factors, the horizontal and vertical
spacings of some of the monitoring wells at the Panoche
Facility are not adequate.
South-southwest of pond 12, between MW-54 (previously
MW-1) and the cluster of wells that was just mentioned,
a distance of about 300 feet is not being monitored. The
ground water contours indicate relatively steep hydraulic
gradient (approximately 0.25) at this location, also the
existance of a relatively extensive fracture has been
revealed by trench T-l (see Figure 6). The fault
apparently runs parallel to the facility boundary and is
located in a saddle. Therefore, the fault plane in this
area needs to be monitored. If the saturated weathered
zone is up to 20 feet at this location one fully penetra-
ting well is sufficient. If the saturated zone is more
than 20 feet, two wells will be required, to monitor the
top and the bottom portions of the weathered bedrock.
The area west of pond 13A (the compliance point) is
being monitored by two deep wells, MW-35 and MW-36. These
wells are screened from 75-85 feet and 110-125 feet res-
pectively. During wet seasons, in well 35, depth to water
is typically 63 feet and during dry seasons it is about
66 feet. At well 36, depth to water during wet seasons is
about 81 feet and during dry seasons it is around 86 feet.
None of these two wells are monitoring the uppper portion
-------
-48-
of the aquifer at the water level, therefore they are not
adequate to detect volatile organics. The facility should
install one monitoring well close to wells 35 and 36 with
the screen interval monitoring the upper portion of the
aquifer.
There is one monitoring well, MW-16, which is accept-
able by. EPA as a background well. MW-16 is an upgradient
background well which is located at the most northern part
of the facility. It is completed in the upper unweathered
bedrock and the screen interval is from 29 to 44 feet.
During the dry season the water level is typically 10 to
12 feet, and in the wet seasons it rises to about 4 to 5
feet.
EPA does not consider the locations of other back-
ground wells (proposed by the facility) to be adequate
for this purpose. These wells are MW-23, MW-22 and MW-20.
Monitoring well MW-23 is located in the N Canyon,
a natural discharge area, and it is east-southeast and
relatively downgradient of the north drum burial area
(Figure 2).
Monitoring well MW-22 apparently has detected the
plume which has originated from ponds 0, P and Q.
Monitoring well MW-20 (2500 feet south of the facil-
ity) has somewhat different ground water quality compare
to MW-16, therefore it should not be used as a background
well representing the ambient water quality at the site.
It is recommended that the facility should consider
to install additional upgradient background well Is) in
the vicinity of MW-16 or higher up the elevation. The
additional upgradient well(s) could be screened in weathered
and also deep unweathered bedrock at different locations
so that more information regarding spatial and vertical
variability in ground water quality would be collected.
3. Aquifer Test/Identification of Lower Boundary
The identification of the lower boundary is an essential
facet of the physical characteristics of the upper-most aquifer
at the facility. Therefore, as part of the study and expansion
of ground water monitoring system, the facility has proposed to
further investigate and determine the base of the upper-most
aquifer, by compiling and evaluating reports of groundwater
occurance, existing permeability data, geochemistry of ground-
water in weathered and unweathered zones, and also by conducting
feild tests and installing additional wells. The field test
program would allow some initial evaluations of connections
-------
-49-
between water producing zones. The following table briefly
.describes the field test locations and new wells proposed by
the facility, and also the additional locations and monitoring
wells which EPA is requesting from the facility:
Well No.s
MW-35, 36, and
(New shallow well,
see P 48)*
MW-38, 39, 10*
(New shallow well
close to SB-8)*
Piezometer Nest
SB-4
Piezometer Nest
SB-5, and MW-41*
Completion Intervals
75-85, 110-125, and
(Top of the saturated
zone at G.W. level)
66-76, 129-158, 26-51,
and (Top of the saturated
zone at G.W. level)
34-44, 201-211 & 261-271
86-96, 119-129, 201-271,
and 26-36
Additional
Facility Proposal EPA Request
SB-3 & (new shallow 131-151 & 30-40 (proposed)
well)
MW 42 & (new deep
well)
MW-51*, 50*, (new
deep well)*
13-23 & (to be determined)
18-28, 18-28, (first water
bearing zone or fracture
in unweathered bedrock)
X
MW-24*, 46*, & (New 40-50, 51-61,
deepwell)* (to be determined)
* New wells, and/or existing wells which EPA is requesting to be
added to the pump or bailer tests.
The following paragraphs explain why the new locations
and installation of additional monitoring wells, for the field
tests, are requested by EPA:
The area east of ponds O, P and Q is monitored by several
shallow monitoring wells (MW-49, 50, 51, 53). There are no deep
wells for monitoring the unweathered bedrock specifically at
the fault VI zone. Based on the maps provided by the facility
MW-51 appears to be close or at the fault zone. Therefore, the
proposed new deep monitoring well (by EPA) at this location is
necessary for evaluation of any connection between weathered and
unweathered bedrock and the hydraulic conductivity values at the
fault zone.
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The area south of the central area, south of ponds, 1 and
2, has not been investigated adequately for the depth of the
uppermost aquifer, for identifying the fault zone (fault V)
accurately/ and for the geologic and hydrogeologic characteris-
tics of the unweathered bedrock. The facility should provide
information and adequate data regarding the extent of the upper-
most aquifer, any potential connection with deeper water bearing
zones, the characteristics of the fault zone and its exact trend
and location..
The scope of work for field tests will begin with slug
test on" each well. Following the slug tests, pumping tests
will be run in the deep wells to further evaluate possible
hydraulic connections and to measure water producing properties
of these zones. The pumping tests and the frequency of measure-
ments should be adequate enough to generate the "time-drawdown"
curve(s) for shallow and deep wells.
In brief, the proposed locations for new wells by EPA are
essential to reduce the existing data gaps, and better compre-
hend the possible pathways, where preferential flow might occur.
These wells will also provide more information regarding the
existing contaminant plumes and will be part of the assessment
monitoring system and delineation study of the plumes which are
discussed in the following sections.
F. Contaminant Plumes, Facility's Assessment Monitoring Plans
In February 1984, the facility notified CA RWQCB indicating
that contaminant have migrated offsite, down gradient from ponds
12-13 and remedial action was initiated. Data showed monitoring
wells MW-2A, MW-2B, MW-10, MW-13, MW-17, and MW-18 have been
effected and that contaminants have migrated outside of the
designated disposal areas, possibly from pond 12 through 16.
Also, the geotechnical information submitted in July 1984 and
subsequent water quality data from wells f MW-7 and MW-21 in
October 1984, indicated that wastes and/or waters that have
contacted wastes were present outside of the designated disposal
area. These wells are downgradient from ponds O, P, and Q,
therefore it appeared that these ponds are contributing to this
situation. Under the interim status groundwater monitoring
program the facility started the assessment of the ground water
contamination and remedial works.
According to the facility, remedial actions at ponds 12-16
commenced by not disposing liquid waste in those ponds any more,
and by drying and removal of all the sludge and capping the
ponds. Therefore, the head was eliminated and the source of the
plume was removed. A french drain system was also installed
south of ponds 12-13 to collect the seepage. The sludges were
also removed from ponds 0 and P and after double lining started
accepting liquid wastes. The facility also asserts that,
pond Q has not received any liquid wastes since November 1985.
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In order to determine the extent of contaminant migration
from the ponds. The facility have been conducting investiga-
tions which are atill on going. The investigations consisted
of excavation of trenches to locate and characterize suspected
fault zones. Characteristics of these zones at greater depths
were investigated with boreholes and continuous cores. Combina-
tion of geologic logging of the cores, borehole geophysical
logging and in situ permeability testing were used to evaluate
subsurface conditions and flow paths. The vertical extent of
chemical migration into the soil was investigated below the
ponds by drilling, sampling and chemical analyses. Also, in
mid-198-6 the facility identified another area, north drum burial
area, where contamination has been detected in ground water.
Analysis of samples taken by GWTF during field investigation,
have verified the existance of these contaminant plumes. Two
additional areas of concern (pond 8 series and SWMU 61) have
been identified by the GWTF where the facility should inves-
tigate and assess the problems. These two areas are discussed
in section G (Subsections 3 and 5).
1. Area West, Southwest of Ponds 12-16
The facility has conducted investigations to identify
the vertical and horizontal extent of the contaminant
migration.
Vertical extent of contaminant migration into the soil
beneath the ponds has been interpreted chiefly from the
results of the pond borings. Chloride concentrations were
interpreted by the facility to indicate the maximum depth
of chemical migration. Depths to the first samples with
concentrations at background levels are:
Pond 13 47 Feet
Pond 14 44 Feet
Pond 15 37 to 48 Feet (results from 3 borings)
Pond 16 33 Feet
Waste Pile 13A 36 to 48+ Feet (results from 2 borings)
A maximum depth for pond 12 was not determined because
of contamination of soil samples during sampling.
According to the facility, the maximum depths at which
elevated TOG and oil and grease concentrations were found
in the soil are as follows:
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TOC Oil and Grease
Pond 12 17 17
Pond 13 NE 22.5
Pond 14 0-22* 0-22*
Pond 15 . NE 0-13b
Pond 16 17.5 NE
Waste Pile 13A NE 13.5-19.5 (two borings)
NE - No elevated value
a = Elevated value found in one out of two borings.
b = Elevated value found in two out of three borings.
According to facility, because of high variability at metal
concentrations and lack of trends, a definite migration depth
for all metals could not be determined with certainty. However,
some conclusions were drawn from chemical results about the
vertical migration potential of various metals.
Elevated nickel and Zinc concentrations were found at 8.5
feet in pond 16. Elevated lead concentration were observed to
a maximum depth of 54 feet. However, the facility questions
the elevated value of lead at this depth since it is below the
maximum depth of chloride migration in pond 13.
Investigations performed by the facility to identify the
horizontal extent of the contaminant migrations have indicated
that the ground water has been affected by contaminants in
monitoring wells 17, 18, 2B, 23 and 29. The ground water
contamination was characterized by high concentrations of
parameters including chloride, and total disolved solids (TDS) .
As the ground water moves towards the west these parameters
show a decrease in concentrations. Further north, west of
pond 14, elevated chloride, sulfate and TDS are detected in
MW-13 and down gradient wells C-4, MW-31. South of pond 12,
wells C-2 and MW-1 (replaced by MW-54) show elevated values
of parameters including chloride, sulfates, and TDS.
Corrective measures have been taken by the facility
to remedy the seepage of contaminated fluid from ponds 12
through 16. In 1984, ponds 12 through 16 were drained and
bottom sludges were removed. The pond area, were capped with
two- to four-foot layer of compacted, clean, clayey fill to
prevent infiltration. In 1981, at the southwest toe of the
pond 12 dike, a 100 foot long subsurface drainage trench was
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installed, as part of the stability of the containment struc-
ture, to collect fluids seeping through dike material and
return these fluids to the pond. In April 1984 two other
subsurface drainage trenches were added, one located along
the toe of the containment dike on the northeast of ponds,
12 and 13, and the other along the south side of pond 12.
South west of ponds 12 and 13, a 12-inch diameter recovery
well with a submersible electric pump was installed in April
1985. The initial rate of recovery was 5.2 gallons per hour,
which it dropped to 0.5 gallons per hour after couple months.
2. North Drum Burial Area
In mid 1986, a field investigation was initiated to assess
the level and extent of leachate migration away from the burial
cells. Eight boreholes were drilled at the drum burial area.
Seven of them were positioned downdip and downslope of the
burial cells and one borehole (ND-7) was positioned upslope and
updip of the area to provide background information. Depths
of these boreholes were in the order of 34 to 39 feet except
in ND-7 were the borehole is 49 feet deep (Figure 2). The
results of the chemical analyses of the soil and rock composites
have detected low levels of certain volatile organic compounds
as well as low levels of some priority pollutant metals and
occasional traces of phathalates.
The results of priority pollutant metal analysis indicated:
Arsenic up to 43 ppm (ND-8)
Chromium up to 68 ppm (ND-8)
Copper up to 69 ppm (ND-3)
Lead up to 7 ppm (ND-4)
Nickel up to 84 ppm (ND-4)
Zinc up to 100 ppm (ND-4)
These results are less than the Total Threshold Limit
Concentration (TTLC) values.
Detected volatile organcis were:
• Carbon tetrachloride 1.3 ppm (ND-S)
• Chlorobenzene 0.013 ppm (ND-2)
• Chloroform 1.9 ppm (ND-8)
• 1,2-Dichloroethane .0185 ppm (ND-8)
• Trans-l,2-Dichloroethene 0.26 ppm (ND-8)
« 1,2-Dichloropropane 0.25 ppm, average value, (ND-8)
• Methylene chloride up to 66 ppm (ND-8)
• Tetrachloroethene up to 3 ppm (ND-8)
These concentrations were detected at depths of about
32 feet (ND-8) and 20 to 30 feet (ND-2).
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.Monitoring well, MW-11 and upgradient well MW-16 were
sampled also. Elevated amounts of chloride (250 ppm),
nitrate (22 ppm), TDS (1200 ppm), Spec. Cond. (1910 umhos/cm),
Sulfate (200 ppm) and TOG (4.25 ppm) in MW-11, relative to
MW-16, indicate that the ground water has been affected by
leachate from the north drum burial area.
3. Ponds 0, P and Q Area
The results of the preliminary investigation of the soil
chemical analytical work and ground water quality performed in
early 1985 indicated that soil and groundwater in the vicinity
of ponds 0, P, and Q have been contaminated. The following is
a summary of vertical and lateral extent of contamination
reported by the facility.
The soil samples indicated acidic pH values (2.05-4.30)
usually to a depth of about 21 feet. However, in PB-104 pH
value of 4.30 was identified at depth of 50 feet. Elevated
chloride concentrations and elevated trace element concentra-
tions were mostly related to areas and depths where acidic
pH values were observed.
Most of the soil samples from soil borings, showed alka-
line pH values ranging from 7.10 to 9.20. These alkaline pH
values were mostly observed at depths greater than 30 feet to
a maximum depth of 55 feet (PB-107).
Lateral extent of migration of plume chiefly was indicated
by elevated TDS (most notably chloride), and elevated levels of
specific conductance. South of the ponds as far as MW-42 has
been effected by plume migration. Monitoring well C-6, north-
east of the ponds area has shown moderately elevated chloride
and specific conductance values. These values showed decrease
in levels in MW-22, which is located downgradient from C-6.
Initial investigation of the pond 0, P, and Q area involved
drilling boreholes to obtain soil and rock samples in the pond
area and performing electromagnetic and resistivity surveys in
the area surrounding the ponds. Additional monitoring wells
were installed to monitor the effected ground water. The
ground water monitoring is still ongoing and the facility is
in the process of compiling and analyzing additional water
quality data.
4. Area South of Ponds 1 and 2
By letter to the Regional Water Quality Control Board
dated September 30, 1985, IT indicated that seepage to the land
surface had been detected in the area south of ponds 1 and 2.
The letter described a plan for installation of shallow collec-
tion trenches which were completed by April, 1986. Seepage was
later observed downslope from these trenches in the area between
trenches and unit 2B. The collection trenches were extended
and deepened during the fall of 1986 to capture this seepage.
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Monitoring wells MW-24 and MW-46, produced samples that
suggested mixing of ground water with leachate from waste
materials. Measured chloride concentrations in water samples
from alluvial fill, ranged from 1,400 to 3,000 ppm during the
period November, 1984 to April 1986. The range in measured
chloride concentrations in samples from MW-46, completed in
the base of the alluvial fill in the same location was 7,700
to 8,300 ppm during the period October, 1985 to April 1986.
The facility is in the process of determining the vertical
and horizontal extent of waste constituent migration in ground
water.. For the area south of ponds 1 and 2, the work will
involve identifying waste materials in the underlying fill in
addition to establishing effects on ground water quality. The
scope of work includes: Conducting electromagnetic and resis-
tivity surveys to outline areas of anamolous conductivity
values in ground water; auger six to eight boreholes between
ponds 1, 2, and 2B and taking core samples (every 5 feet) for
chemical analyses; converting selected boreholes to monitoring
wells, the wells will monitor the alluvial materials, weathered
bedrock, and unweathered bedrock.
G. Evaluation of Facility's Assessment Plans
1. Ponds 12 through 16
The facility in conjunction with the requirements of"
the RWQCB has proposed additional Investigation regarding
assessment of contamination plume in the vicinity of ponds 12
through 16. The investigations include:
1- Water quality analysis by comparisons of samples from
surface sampling, shallow and deep wells.
2- Review of fluid migration by further evaluation of
mechanics and paths of fluid migration. Most recent sub-
surface data will be combined with previous information
and new detailed cross sections, addressing potential
pathways, will be developed.
3- Hydrologic characteristics of the Paddy Creek watershed
will be evaluated further which will include evaluation
of seeps, springs, and surface and ground water quality.
4- Three new monitoring wells will be installed to inves-
tigate possible effects of plume migration on ground
water in the Paddy Creek drainage, these wells will be
placed:
• Upstream of the confluence of tributaries, that
originate in the ponds 12 through 16 area,
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' East side of Paddy Creek, few hundred feet downstream
Of MW-56,
* East side of Paddy Creek, downstream of the tributary
containing MW-28 and MW-29.
The proposed locations of the three monitoring wells in
the vicinity of Paddy Creek is suitable, however they are not
sufficient for delineation of the existing plume. Additional
monitoring wells should be installed in the effected area to
fully characterized the extent and rate of the contaminant
plume.
1.1 Additional EPA Requests;
The following paragraph identify the locations where EPA
is proposing the additional monitoring wells should be
installed.
* One shallow well should be installed downgradient
from MW-39 at the fault IV zone, approximately half
way between Paddy Creek and MW-39. The screen
interval should be placed at the ground water level
in the fractured bedrock.
* A monitoring well should be installed close to
shallow well MW-26, at the fault II zone. The
screen interval should be placed in the fractured
bedrock to monitor the fault plane (the screen
should be placed immediately below the MW-26 screen
interval). This new well will provide additional
information about fault II and its effect on hori-
zontal and vertical component of the ground water
flow.
* The shallow well proposed to be installed in the
vicinity of deep wells MW-35 and MW-36 (see P.48)
will provide information regarding the concentra-
tion and possible contamination of ground water by
volatile organics (MW-35 and MW-36 are not adequate
to detect volatile organic contaminants). The
screen for the shallow well should be placed at
the water table to monitor the top portion of the
saturated zone. (MW-35 monitors to interval from
75 to 85 feet and water level is usually at about
63 to 66 feet, therefore, about 10 to 12 feet of
the upper saturated zone is not being monitored).
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0 MW-33 in the dry season does not produce sufficient
amount of water for sampling. The screen interval
is from 23.5 to 33.5 feet and the depth to ground
water level fluctuates from 24 to 30 feet. Since
the location of this well is important for plume
delineation in the vicinity of Paddy Creek, another
monitoring well should be installed in this area.
The new well should monitor the deeper zone below
the clay gouge identified at the bottom of MW-33.
* The replacement wells in the vicinity of MW-17,
MW-18, and MW-19 (proposed by EPA, see P.46),
will provide information regarding the extent
and level of contaminants, specifically volatile
organics. In addition deep monitoring wells are
required to initiate the study of vertical extent
of ground water contamination in the proximities
of MW-17, MW-19 and also MW-2a and 2b.
* Proposed new monitoring well (proposed by EPA,
see P.47) west of MW-54 in the saddle where an
extensive fracture exists (in the vicinity of T-l
and T-S), should be included in the assessment
program regarding the extent of contamination from
ponds 12 through 13A. Another shallow monitoring
well (screened at the G.W. level) should be installed
south of MW-1 in the same tributary. MW-1 has shown
evidence of contamination therefore the extent of
the plume in this area must be investigated.
2. South of Ponds 1 and 2
The scope of work to investigate contaminant plume
south of ponds 1 and 2, proposed by the facility, include:
1- Containment of surface seeps south of ponds,
2- Conducting surface geophysis (EM and resistivity)
in the area between ponds 1 and 2 pond 2B.
3- Drilling 7 boreholes between ponds 1 and 2 and
pond 2B for geochemical analysis.
4- Converting 3 of the borings to wells capable of
monitoring the alluvium and weathered bedrock.
5- Defining the areal extent of solid waste materials
in the area and southward extent of waste constituent
migration in the ground water.
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2.1 Additional EPA Requests
None of the existing wells south of ponds 1 and 2, namely
MW-24, MW-46, and MW-52 are adequate for detection of volatile
organics in the ground water. All these wells monitor the
mid or lower portion of the saturated zone in the alluvial
deposits. In the vicinity of MW-24 and MW-46, 30 to 40 feet of
upper saturated zone is not being monitored. In the vicinity
of MW-52 the unmonitored upper portion is about 9 feet. There-
fore, several shallow wells south, southeast, and southwest of
ponds 1 and 2 (at the compliance point) are required to monitor
effectively for volatile organics. In addition deep monitoring
wells are required to monitor the weathered and unweathered
bedrock. Furthermore, the trend of fault V and its depth must
be identified and the fractured bedrock in the fault zone
should be monitored. In brief, the proposed 3 monitoring
wells are not sufficient to initiate the plume assessment and
to characterize the aquifer south of ponds 1 and 2. There is
indication that fault V strikes north northwest and passes
beneath pond 2. Fault II strikes northwest; it passes close
to southwest corner of pond 2 and runs parallel to pond 8
series. In addition couple other monitoring wells are required
to be installed downgradient from MW-52, MW-46 and/or MW-24,
closer to pond 2B.
Due to physical setting of the site most of the ground.
water discharges into the drainage basin in the central and
south of the facility. The ground water at this drainage area
becomes contaminated due to contact with sludges that exist
beneath the central area. The facility with the aid of piezo-
meters and monitoring wells should construct flow nets for the
area of pond 2B and determine whether the ground water beneath
this pond has vertically upward or downward gradients. If
there is an upward gradient, some of the contaminated ground
water might be discharging into the pond 2B. Therefore, as an
integral part of the assessment program for this area, the
facility should also collect some samples of the sediments
and/or sludges from the bottom of pond 2B. A complete GC/MS
analysis should be performed utilizing methods 3240 and 3250
(SW-S46) for volatile and semivolatile organics. EP toxicity
test should also be performed on the samples. Furthermore,
the assessment program for the area south of ponds 1 and 2
should be expanded to south of pond 2B. MW-25 and MW-14 have
both detected elevated levels of heavy metals, and indicator
chemicals (Table 5). None of these two wells are screened
at the water table, so they are not adequate for detecting
volatile organics. The facility should install shallow wells
south of pond 2B to further investigate the possible extent
and rate of the plume. Apparently wells 14 and 25 have begun
to detect the edge of the plume which has originated from the
central area and south of pond 1 and 2.
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3. Ponds 0, P, Q and Solid Waste Management Unit 61
The directions of contaminant migration from these ponds
(0, P, and Q) are toward south, southwest, southeast, and east
The proposed supplemental work on the ground water monitoring
program include:
1- Drilling deeper boreholes at 7 of the 12 original
locations: PB-102 through PB-106, MW-44 and MW-49
(For locations see Figure 2), and
2"- Replacement of wells C-6, MW-41, MW-48, MW-53, MW-12.
3. 1 Additional EPA Requests
Existing monitoring network south of ponds O, P,
and Q and the proposed supplemental work are adequate for
characterizing the extent of the plume, south of the ponds,
inside the facility boundry. East-southeast migration of
the plume is being monitored by monitoring wells MW-51 and
MW-50. The screens are placed in a way so that little more
than half of the lengths monitor the weathered bedrock and
the bottom protions monitor the unweathered bedrock (screen
intervals are from 18 to 28 feet), the peizometer level in
this area in dry seasons drops to approximate depths of 23
to 25 feet, which is almost at the contact of weathered and
unweathered bedrock. In MW-50 water table drops to about
26 feet, leaving only 2 feet of water column in the screen.
In brief, more monitoring wells are required in this area
to monitor the upper portion of the unweathered bedrock. A
well could be placed in the vicinity of MW-50, and screened
approximately from 25 to 30 feet.
Another set of monitoring wells are required in the
vicinity of PB-107, outside of the facility boundary, east of
MW-50. As discussed earlier (see P.54) alkaline pH values
(7.10 to 9.20) were observed at depths of .30 to 55 feet in
PB-107 The borehole is located almost on top of a ground water
divide, where the flow probably changes directions in two
opposite paths. One direction could be northeast towards the
tributary containing MW-22, and the other south-southwest,
toward MW-27, MW-6 and the tributary which originates in
this area. This tributary probably reflects the trend of a
possible fracture (Figure 12). One monitoring well should be
installed in each of these flow paths, northeast and southwest
of PB-107. The top of the screens should be placed at the
ground water level (in weathered or unweathered bedrock).
Another well should be installed at or close to PB-107 and
screened in the fracture zone where high pH values were
detected.
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. ; Tributary containing MW-22 is the reflection of a major
fracture that connects the Green Valley fault to fault I (pre-
viously A) at the facility (see Figure 12). Since MW-22 has
shown evidence of contamination, additional shallow monitoring
wells should be installed further downgradient from MW-22 in
the drainage for defining the horizontal extent of the plume
and for studying the rate of that plume.
Deep monitoring wells are required in the vicinity of
MW-49, and MW-51 to monitor the unweathered bedrock and to
define vertical extent of contamination in groundwater.
The deep well close to MW-51 will also provide information
regarding fault VI, fractured unweathered bedrock in that
zone, and possible connection between unweathered and upper
weathered bedrock.
Solid waste management unit (SWMU) 61, southeast of ponds
0, P, and Q has not been addressed by the facility in their
assessment program. This SWMU could be another or the main
source of contamination for monitoring wells MW-47, MW-48, and
MW-27. These wells are down gradient from SWMU 61, at the foot
of the ridge where SWMU 61 is located (see Figure 2). The
facility should investigate the possibility of this unit as a
source. Preliminary geochemical borings for sampling of the
soil beneath SWMU 61 is necessary. The ground water levels
should be noted and the gradient between the piezometric surface
beneath the SWMU and the monitoring wells MW-47, MW-S, MW-27,
and MW-48 must be established. The ground water chemistry
beneath the SWMU 61 and the above monitoring wells should be
correlated.
Potential directions for possible plume migration from
SWMU 61 would be toward south and southeast. Monitoring well
MW-48 is almost at the southern tip of the unit. Monitoring
wells MW-47, MW-5 are located east and downgradient from the
unit, and MW-27 is further downgradient, southeast of the unit.
The facility should assess the area and submit the results of
evaluation regarding SWMU 61 and the possibility of it being a
source of contamination for the mentioned monitoring wells.
Furthermore the extent of the existing contamination east and
south of this SWMU must be investigated. Additional shallow
monitoring wells are required to monitor: 1) the tributary
trending east between MW-5 and MW-27, and 2) the area turther
downgradient from MW-48, toward south, along the facility
boundary.
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4. North- Drum Burial Area
The geology and hydrogeology of this solid waste
management unit are not studied as well as other areas at the
Panoche facility. As discussed earlier a recent subsurface
investigation of the area was conducted to obtain preliminary
information. A total of eight boreholes were drilled, and
the facility has proposed to install a total of fifteen moni-
toring wells--inside and at the perimeter of the drum burial
area (Figure 18) to assess the extent of leachate into the
ground water. This system of wells will monitor both the
weathered and unweathered bedrock including the fault line
(fault I) which passess beneath the burial area. The boring
and monitoring wells will also provide information regarding:
Ground water levels to define flow directions and rates,
stratigraphy and piezometric heads on either side of the
fault line to assess the impacts of the fault on the hydro-
geologic regime, water quality data to define potential
contaminant migration.
The scope of work is adequate for preliminary assessment
program, although the facility has not defined specifically
how-deep the ground water monitoring wells will be installed
at various locations. One issue of concern is the location of
MW-23 which is located at the natural depression and drainage
area called the N canyon. The facility is considering MW-23
an upgradient background well relative to the facility's waste
management units. However, this well is located east-southeast
and relatively downgradient from the north drum burial area
(Figure 2). Since local and secondary ground water flow paths
from the burial area could effect the ground water at MW-23,
EPA will not accept this well as a suitable upgradient back-
ground well. Due to its location, MW-23 should be included
in the assessment monitoring program of the burial area.
5. South of Pond 8 Series
During the GWTF field investigation, as part of the pro-
gram, piezometer nest 4 (4A, 4B, 4C) were sounded for ground
water level recordings. Piezometer 4A is the deepest well.
It is screened from 261 to 271 feet, and the screened interval
is placed in shale with thin sandstone interbeds. Piezometer
4B is the intermediate well which is screened from 201 to 211
feet. It also is screened in the same lithology as 4A. Piezo-
meter 4C is the shallow well and is screened from 34 to 44 feet
in the shale. The top 1 or 2 feet of the screen is in the
limestone interbeded with shale.
Before the sounding, as part of the project plan, the
piezometers were screened, at the well head, for any organic
vapors using a photovac. After the well cap was removed, the
probe of the photovac was inserted into the well head and
readings were recorded. Piezometer 4A readings indicated
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high-values of organic vapors, 20-30 parts per million (ppm).
Well 4B reading indicated 2 ppm and well 4C, 1.5 ppm. The
photovacs were calibrated daily for background ambient air
which the values ranged from 0 to 0.5 ppm.
The high values of organic vapors in piesometer 4A indi-
cate that the ground water is contaminated and that contamina-
tion has possibly migrated vertically into the unweathered
bedrock to depths of 200 feet or more. These piezometers are
placed in one borehole and the specifics on the construction
of these wells are not available. Very little is known about
the geology and hydrogeology of this area, except the existence
of fault II which apparently runs very close to SB-4 cluster.
The facility should investigate the area and confirm the air
monitoring results (at the well heads) performed by the GWTF.
If the results are positive, a plan should be submitted regard-
ing geological and hydrogeological investigation of the area
including plans for installation of monitoring wells in clusters
and along the fault. Monitoring wells, the ones in cluster(s),
should not be placed in a single borehole.
6. Summary of Evaluations Regarding Detection and Assessment
Monitoring
In brief, evaluation of the facility's ground water
monitoring systems and the assessment program indicates that
additional wells at the compliance points ($244.99(b) 40 CFR)
and down gradient from the waste management units are neeaed
(as specified in the report). The major deficiency of the
detection monitoring system is the lack of adequate shallow
wells with appropriate screen intervals, for detection of
volatile organics. At several locations, specifically south of
ponds 1 and 2, south of pond 2B, and west of ponds 12 through
13A, where contamination has been detected, full length of the
saturated zone in alluvial deposits and weathered bedrock is
not being monitored. The assessment program (overall) lacks
sufficient monitoring wells to effectively and within reasonable
time period delineate the extent of the plumes (vertically and
horizontally), and to accurately define the concentrations of
hazardous waste constituents in ground water.
It should be noted that the number and location of
monitoring wells proposed by the GWTF are not by any means
final. Also, the proposal does not imply that it will make
the assessment monitoring systems, complete. Further along
the assessment program there might be a need for additional
monitoring wells in order to be able to fully define the
periphery of the plumes. The proposed locations and screen
intervals are chosen primarily based on complex and extensive
faulting and folding structures at the facility/proximities,
and lack of adequate and effective ground water monitoring in
specific areas. The exact locations and screen intervals are
subject to change depending on accessibility and variations
in field conditions.
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-63-
H. Summary of Statistical Analysis Performed on Facility's Data,
and HWGWTF Sampling Results
1. Ground Water Statistical Results
The following is a brief summary of the results of
statistical analysis performed on IT Panoche's ground water
data (1984-1986) by, Camp Dresser and McKee (CDM), EPA's
contractor*
0 Local seasonal precipitation patterns appear to be
correlative with changes in ground water levels within
the shallow aquifer and in deeper unweathered zone
which implies hydraulic connection between weathered
and unweathered bedrock. Time-series analysis of ground
water chemistry did not identify a seasonal pattern due
to insufficient data over an annual cycle during and
after periods of significant recharge.
" The number of parameters (35) measured in ground
water from the IT Panoche site was reduced to a more
manageable set by using correlation statistics and
factor analysis. Briefly, the goal of factor analysis
is to explain the relationships between variables by
the presence of a few factors. The objective of using
factor analysis was to select a set of indicator para-
meters which would describe most of the variance in
the data set.
0 Cluster analysis was employed to classify the IT vari-
ables into more or less homogeneous groups so that
inter- and intra-group relations become apparent.
Cluster analysis was used in conjunction with factor
analysis to select indicator parameters and to group
wells based on their water analyses. Five groups,
based on the specific conductivity and cl:SO4 ratio,
were distinguished. Table 2 summarizes the general
characteristics and the wells in each group.
* Analysis of variance (ANOVA) was used on the IT-Panoche
site data to test for differences in analyte populations
between specified wells. ANOVA techniques test for
differences in sample means by comparing them with the
variance. The ANOVA routine was less prone to false
positive conclusion error in this survey (probability
of error was 0.01). For the situation in which two
wells are compared, ANOVA is equivalent to the students
T-tests; both accept or reject the hypothesis identically
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-64-
MW-20 was compared with MW-16 to identity whether MW-20
could be used as a background well. The comparison
indicated TOX and TOG appear similar while Cl, Sp.
Cond., and 804 are representative of different popula-
tions (Table 2-8, Appendix B, CDM report). Based on
this analysis MW-20 should not be considered represen-
tative of ambient water quality conditions in the IT
Panoche watershed.
Well MW-14 (south of pond 2B) which represents cluster
1 was compared to the background well, MW-16. The
-analysis of variance (ANOVA, see Table 3) indicates
that TOC and TOX are similar while CA, Cl, SO4/ and Sp.
Cond. come from different polulations. This suggests
the existance of a subsurface C1/S04 plume. The con-
clusion is that the water quality of wells in cluster 1,
namely 2B, C6, MW-7, MW-13, MW-14, MW-17, MW-21, MW-28,
MW-45, MW-49, MW-53, and MW-56 are degraded significantly
from ambient water quality.
Comparison of background well (MW-16) with well MW-22,
cleanest water quality in cluster #3, indicates pre-
sence of contamination beyond the boundary of waste
management area. The ANOVA test (Table 3) indicated that
Ca, Cl and 804 differ while the Sp. Cond., TOC and TOX
are similar. By inference this suggests that all areas
represented in cluster #3 are contaminated by leachate.
These wells are MW-10, MW-22, MW-27, MW-25, MW-29, MW-34,
MW-41, MW-43, MW-46, MW-48, MW-51, and MW-52.
MW-31 was selected from cluster 14 for comparison with
the background (MW-16) water quality. The ANOVA results
indicate (Table 3) exceeding values for Chloride,
Spec. Cond., Ca, and TOC relative to the background.
The conclusions from this test are that the wells in
cluster #4 (MW-1, MW-26, MW-31, MW-47, and C2) exhibit
contamination and that chloride and some organic cons-
tituents migrating off site to the west and south.
Cluster 12 consists of the background well MW-16 and
four of the five deep unweathered bedrock wells (MW-36
through MW-39). These wells are characterized by a
specific conductivity generally between 1500-5000 us/cm
and generally low cl and SO4. Cluster #5 may be gene-
rally characterized by low concentrations of Cl and 804
and by a low Sp. Cond. (<1000 us/cm). Two wells from
clusters #2 and #5 (MW-39 and MW-35, respectively) were
compared with background conditions. The results indi-
cate the upper unweathered bedrock has significantly
more chloride than either background or deep unweathered
bedrock. This implies vertical migration of chloride
through alluvium and weathered bedrock in the vicinity
of ponds 13 and 13A based on the ground water chemistry
at wells MW-35 through MW-39 (see Table 4).
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-65-
2. HWGWTF. Ground Water Sampling Results
The following summary explains the analytical results for
the ground water samples collected by HWGWTF in August 1986.
' All wells that were sampled showed at least one inor-
ganic indicator or total metal value above background
(except MW-9A). The maximum concentration for chloride
was 36,200 ppm (MW-49), Sulfate up to 1,130 ppm (MW-39),
TOG up "to 212 ppm (MW-17), TOX up to 0.065 ppm (MW-49),
nitrate nitrogen up to 67.5 ppm (MW-46), amonia nitrogen
.up to 2.10 ppm (MW-36), and bromide up to 60 ppm (MW-21).
As for metals, in general, detection of relatively high
levels of aluminum up to 16.60 ppm (MW-47), barium up
to 6.29 ppm (MW-49), calcium up to 9,590 ppm (MW-49),
iron up to 15.4 ppm (MW-47), manganese up to 880 ppm
(MW-49), potassium up to 21.8 ppm (MW-49), sodium up
to 1,100 ppm (MW-17), vanadium up to 0.129 ppm (MW-49),
and magnesium up to 4,490 ppm (MW-49) were reported.
Chromium which has been identified as one of the indi-
cator chemicals by seasonality and statistical analysis,
show four low level hits: MW-9B (0.007 ppm), MW-17
(0.008 ppm), MW-39 (0.006 ppm), and MW-52 (0.006 ppm).
However, chromium data for 15 (15 out of 30) of the
monitoring wells were reported as unreliable according
to QA/QC. Therefore, due to insufficient data, adequate
assessment of chromium can not be conducted.
* Monitoring wells MW-7, MW-11, MW-46, MW-48, MW-49 and
MW-51 showed some level of concentration for volatile
organic compounds. Monitoring well MW-7 indicated
0.0069 ppm of tetrachloroethene. MW-11 indicated
0.0038 ppm of chloroform, 0.0012 ppm of 1,2-dichloro-
ethane, 0.0015 ppm of trans-1,2-dichloroethene, 0.0033
ppm of 1,2-dichloropropane, 0.0093 ppm of 4-methyl-2
pentanone, 0.0018 ppm of 1,1,1-Trichloroethane, 0.0084
ppm of TCE and 0.0016 ppm of 1,2-dibromoethane. MW-46
indicated 0.0072 ppm of 1,2-dichloroethane, 0.0056 ppm
of trans-1,2-dichloroethene and 0.0054 ppm of TCE.
MW-48 indicated 0.0066 ppm of TCE. MW-49 showed 0.0019
ppm of chloroform and MW-51 indicated 0.11 ppm of
tetrachloroethene. In addition these monitoring wells
showed positive estimated values for other volatile
organic compounds (Table 5).
* TOX and chloride which have been identified as indi-
cator chemicals by seasonality and statistical analysis
for wells MW-11 (Tox: 0.254 ppm, chloride: 293 ppm)
and MW-46 (Tox: 0.276 ppm, chloride: 11,300 ppm) fall
in the same range as the data obtained by IT Corpora-
tion for these two wells. Table 5 also shows that
wells MW-46 and MW-11 (respectively) have relatively
higher concentrations of nitrate nitrogen than other
wells sampled by HWGWTF.
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-66-
• Wells MW-7 and MW-49, for indicator chemicals, show
relatively high concentrations of chloride (MW-7:
14,300 ppm, MW-49: 36,200 ppm). These concentrations
also fall within the range of concentrations reported
for the IT Corporation data analysis. Furthermore,
both wells show some level of TOX concentration,
MW-7 (0.119 ppm), and MW-49 (0.675 ppm). TOX for
well MW-46 also falls within the range of the concen-
tration level reported by IT data.
In. brief, the statistical analysis of the IT Panoche
ground" water data indicates that monitoring wells in clusters
1, 3 and 4 are contaminated by the plumes. These wells are:
' Cluster 1: MW-7, MW-13, MW-14, MW-17, MW-21, MW-28,
MW-45, MW-49, MW-53, MW-56, MW-2B, C6
0 Cluster 3: MW-10, MW-22, MW-25, MW-27, MW-29, MW-34,
MW-41, MW-43, MW-46, MW-48, MW-51, MW-52
' Cluster 4: MW-1, MW-26, MW-31, MW-47, C2
The analysis of ground water samples taken by the HWGWTF
confirms the above results. Although, wells in clusters 2 and 5
are generally "cleaner" than the wells in the other clusters,
the more recent GWTF sampling results (relative to the facility
data used for statistical analysis) indicate several of the
monitoring wells in these two clusters are affected and that the
ground water quality has been degraded relative to the ambient
ground water. These monitoring wells are: MW-4 (cluster 5),
MW-11 (cluster 5), MW-24 (cluster 2), MW-36 (cluster 2), MW-39
(cluster 2), MW-42 (cluster 2) and MW-50 (cluster 5). The
statistical analyses have also indicated that MW-35 (cluster 2)
and MW-37 (cluster 5), which are screened in upper unweathered
bedrock, show evidence of chloride contamination.
3. HWGWTF Surface Water and Soil Sampling Results
Six surface water (seep) samples were collected at the
vicinity of the site. Two seeps (#1 and #2) were located in the
quarry approximately 1800 feet east of the facility. Seep ?3
was taken from a tributary northwest of seep #2 approximately
1000 feet away. Seep #4 was taken roughly 1000 feet downgra-
dient from MW-22. Seep #5 was collected 250 feet west of MW-4
in a tributary, and seep 6 was collected from a tributary north
of MW-4, roughly 1200 feet away.
In all samples but one (seep #3), estimated concentration
levels of acetone were detected. Relatively elevated levels
of chloride, nitrate nitrogen, and sulfate were detected in
almost all the samples (compare to background ground water
quality). As for metals, generally elevated levels of aluminum,
barium, calcium, iron, magnesium, manganese, potassium, and
sodium were detected for all samples.
-------
-67-
Three soil samples were collected from one location
approximately 840 feet east of MW-27 in a tributary (For
locations of seeps & soil samples see Figure 17). The soil
samples were analyzed for VOA, Semi VGA, TIC-Semi-VOA, and
total metals. The assumed background soil sample (MQ0870)
showed hits for 2-butanone, benzene, ethyl benzene, 1,1,1-TCE,
toluene, and total xylene. In general, all soil samples were
showing some l.evels of concentration of 2-butanone, and toluene.
As for metals, most of the metals analyzed for were detected
except antimony, cadmium, and thallium.
Almost all the wells, soils, and two of the seeps showed
greater than zero concentration of methylene chloride. How-
ever, most of concentration levels were indicated as estimated
values (J). This compound was also found in blank samples
indicated by flag B. Therefore, methylene chloride, based on
this round of sampling should not be considered as a chemical
of concern. Tables 5 through 7, present the complete analysis
results of ground water, surface water and soil samples.
I. Revisions Regarding Sampling and Analysis Plans
1. Groundwater Sampling and Analysis
In order to assess fully whether annual seasonal
variation is occuring, samples from all the wells should
be obtained during the months of February, April, July,
October and December. The sampling plan should be revised
to include the Appendix VIII or IX compounds so that the
maximum concentration of hazardous waste constituents at
the contaminated areas be defined.
Metals, e.g., As, Cd, Cr, Cu, Pb and Zn, should be
analyzed by graphite furnace techniques rather than atomic
absorption or inductively coupled plasma methods. This
will lower the detection limit and allow the introduction
of match for statistical analysis.
There are some geochemical processes which control
the mobility of certain parameters and which should be
identified in a future analysis. Anaerobic reactions,
disproportionation reactions (which may result in one
product being oxidized, the other reduced), protonation
reactions (which may affect the PH of the groundwater)
and chelation reactions (which may increase the solubility
of cations through complication with organic acids), are
reactions which will tend to enhance metal solubility.
In addition, previous studies (Baedecker and Back, 1979)
have shown that acetic acid can contribute a significant
proportion of the alkalinity (as organic acia anions).
Therefore, the alkalinity of groundwater at the IT Panoche
-------
-68-
facility should be included in future statistical compari-
sons and acetic acid analyzed in future sampling rounds.
The mean alkalinity (414 ppm) is significantly higher
than that found in MW-16 (369 ppm). Also, turbidity for
all wells should be measured during each sampling phase.
The levels of concentrations of contaminants
and hazardous waste constituents should be defined at
the compliance points, and at the points of exposures
(for contaminations outside the facility boundry).
Appendix VIII or IX compounds will be sampled twice a
year during dry and wet seasons for 3 years. The water
levels for all the monitoring wells and piezometers
should be recorded during every sampling phase, and the
depth of wells will be sounded and recorded.
2. Surface Water and Soil Sampling
Due to the detection of several inorganic indicators
and metal constituents in surface water, and also due
to the detection of some volatile organics in the soil
samples, a surface water and soil sampling investigation
is needed.
J. Evaluation of the Statistical Methodology Proposed by
IT Corporation for the Panoche Faciltiy.
Generally, the use of Analysis of Variance (ANOVA) offered
by IT Corporation and the interest in obtaining "true" replicate
samples are reasonable. However, the details of the ANOVA
approach are unacceptable because upgradient concentrations are
not compared with downgradient concentrations and because dif-
ferences among wells and individual well comparisons are not
tested as part of the approach.
The method which IT is proposing to use does not concider
contamination that might be present in the ground.water before
the ground water flows under the hazardous waste management
unit (HWMU) of concern.
IT proposes an ANOVA based method which will indicate
contamination when there is a significant well by time inter-
action. In simple terms this means that the HWMU will trigger
when there is an indication that all wells do not behave in the
same pattern relative to one another over time. The conclusion
is that using a significant well by time interaction as the
triggering threshold can result in both false positive and
false negative results at a higher than anticipated rate.
The more detailed evaluation of the facility's methodology
is included in attachment D of this report.
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-69-
REFERENCES
Data Analysis Report for Technical Support of IT Panoche Facility
Hazardous Waste Ground Water Task Force Investigation, Camp
Dresser & McKee, March 27, 1987.
Beneficial Use Study, IT Benicia Facility, Benicia, Solano County,
California, Leroy Crandall and Associates, May 13, 1985.
IT Panoche Ground Water Sample Plan, Peter Rubenstein, USEPA
Region 9, August 1986.
Project Plan, Hazardous Waste Ground Water Task Force, IT Panoche
Facility, Solano County, California, Hannibal Joma USEPA
Region 9, July 1986.
IT Panoche Laboratory Audit Report, Kevin W. Wong, USEPA Region 9,
September 1986.
IT Panoche Ground Water Sampling Audit, Peter Rubenstein, USEPA
Region 9, December 1986.
EPA Internal Memorandum on "Review of the Statistical Methodology
Proposed by International Technology Corporation for the
Panoche, California Hazardous Waste Disposal Site."
From Barnes Johnson to Hannibal Joma, March 27, 1987.
-------
ATTACHMENT A
-------
ATTACHMENT A
U.S.. Environmental Protection Agency
Region 9
National Ground Water Task Force
IT PANOCHE
SAMPLING AND DOCUMENTATION REPORT
Peter Rubenstein
February 1987
-------
TABLE OF CONTENTS
Page
Introduction 1
Field Work Completed
Modifications, and Clarifications of the
Sample Plan
Validity of Data Based on Field Conditions 11
Appendix A: IT Panoche Ground Water Sample Plan
Appendix B: Field Data Organized by Sampling Point
Appendix C; Documentation of EPA Samples Collected
at IT Panoche, 8/18/86 - 8/27/86
: The anocndicVs A, B, and C are not included in this
report. Tttey ar* available in the E.P.A's fHe.
-------
LIST OF TABLES
Table
EPA, VERSAR, and State of California
Personnel Participating in the 8/18 - 8/28
EPA Sampling Effort at IT Panoche.
Samples collected each day at IT Panoche,
sorted by agency, parameter, identifying
the sample f and the number of sample
containers per parameter.
Wells sampled by EPA with less than 3 casing 8
volumes removed during the purge process.
Wells sampled by EPA with a time lag of
greater than 3 hours between purge completion
and sample collection.
Wells sampled by EPA which included aliquots
for o-rganolead analysis.
Wells sampled by EPA which included aliquots
for Appendix 8 compounds.
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INTRODUCTION
The ground water sampling component of the Hazardous Waste
Ground Water Task Force investigation at IT Panoche was conducted
August 18-28, 1986. The major objective of the fieldwork was to
determine if contaminants could be detected in wells on the site.
EPA with its contractor, VERSAR, sampled 30 monitoring wells, 1
piezometer, and 7 seeps. A total of 53 samples; including Quality
Assurance replicates, performance evaluation, and blank samples
were collected by the EPA. The facility accepted an offer for
replicate samples. The California Regional Water Quality Control
Board (RWQCB) and Department of Health Services (DHS) declined an
offer for replicate samples.
The field activities were based upon a Sample Plan, dated
August, 1986 and prepared prior to the investigation. It is
included as Appendix A of this Documentation Report. Modifica-
tions to the Sample Plan protocols were made in the field when
necessary and were documented in the field notes of the EPA and
VERSAR personnel.
The EPA ground water samples were .shipped to Compu-Chem
Laboratory for organic analyses, Centec Laboratory for inorganic
analyses, and the CA DHS Hazardous Materials Laboratory in
Berkeley for analyses of the organolead and radionuclide para-
meters. The soil samples were shipped to California Analytical
Laboratory for inorganic analyses and Western Research Institue
for organic analyses.
The analytical results for the samples collected will not be
included in this report.
-------
FIELD WORK COMPLETED
A sampling audit was conducted in May, 1986 as part of the
overall Task Force Investigation. At that time an effort was
made to identify the location of the wells and to determine what
special purge or sampling equipment might be necessary to complete
the EPA sampling effort in August. Hannibal Joma, Donn Zuroski,
Randall Breeden, and Peter Rubenstein of EPA were escorted by the
IT Environmental Monitoring Team during this initial investigation.
The EPA and VERSAR sampling teams arrived on site on August
18, 1986, to begin the field investigation. Sampling was conducted
according to the methods and protocols specified in the EPA
Region 9 "IT Panoche Ground Water Sample Plan", dated August, 1986,
and included as Appendix A to this report.
Personnel from the EPA and agencies of the State of California
were also on site at various times during the samapling event to
assist and observe the field investigation. Table 1 identifies
all of the EPA,- VERSAR, and State of California personnel who
participated in this field effort.
On the first day in the field, August 18, the staging area
and equipment were set up and initial measurements of depth to
water were taken. Interface probes were used to determine if any
immiscible liquids were present as the wells were sounded.
Purge and Sampling of the wells began on August 18 and
all EPA fieldwork at the site was concluded on August 28.
IT Panoche assigned staff to escort the Task Force, unlock
the wells, and accompany the EPA and VERSAR personnel while at the
wellhead. After sampling was completed at each well IT personnel
relocked each well. As each sample set was packaged for shipment
IT personnel received custody of the appropriate replicates.
Table 2 summarizes the samples collected on a day by day
basis and sorted by agency. The samples are identified by well
location, sample number, and type of QA/QC sample when applicable.
Total depth, depth to water, the purge/sample sequence, purge and
sampling method, field parameters, and sample numbers are presented
in Appendix B of this documentation report.
-2-
-------
Table 1: EPA, VERSAR, and State of California Personnel
Participating in the 8/18 - 8/28 EPA Sampling Effort
at IT Panoche.
AGENCY
NAME
DATES ON SITE
EPA
Hannibal Joma
Peter- 'Rubenstein
Donn Zuroski
Dan Sullivan
Kevin Wong
Ted Bucklin
Anthony Montrone
Peter Usbee
Judy Cook
Daniel Horgan
Mitch Kaplan
Kathleen Shimroin
Frances Schultz
Barbara Walsh
William Weis
8/18 •
8/18 •
8/18 •
8/18 •
8/27
8/18,
8/18
8/18
8/22
8/22
8/22
8/22
8/22
8/22
8/22
8/27
8/28
8/27
8/27
8/28
VERSAR
Darcy Higgins
Dan Campbell
Alicia Freitas
John Hatcher
Mark McElroy
Don Paquette
Randal Vanhoozer
8/18
8/18
8/18
8/18
8/18
8/18
8/18
8/27
8/27
8/27
8/27
8/27
8/27
8/27
CA DHS
Ed Leivas
Patti Barni
8/18
8/18
SWRCB
Dennis Parfit
8/25
-3-
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VERSAR personnel did all of the EPA sample collection and
handling to insure that the actual procedures were consistent for
each sample. VERSAR provided all of the sampling equipment,
identified in an appendix to the Sample Plan (see Appendix A).
The equipment was decontaminated prior to shipment to the site
according to the protocols established in the "Revised Draft
Protocol For Ground-Water Inspections At Hazardous Waste Treatment,
Storage And Disposal Facilities" dated April 1986.
Immediately after filling the containers at a sampling point
VERSAR personnel would return to the staging area where they
measured turbidity and filtered and preserved those samples as
required. All samples were kept on ice from the moment of
collection.
The EPA and DHS samples/ identified in Table 2, were shipped
on the day of or day following collection. The samples were
shipped by Federal Express with next day delivery to the
laboratories.
The EPA samples were sent to the EPA Contract Lab Program
(CLP) and DHS laboratories for analysis. Centec Laboratory in
the CLP conducted the inorganic analytical procedures on the
ground water samples; total metals, phenols, cyanides, NH3, NC>3,
804, Cl, purgeable organic carbons (POC), purgeable organic
halides (POX), total organic carbons (TOO, and total organic
halides Cr,OX).- Compu-Chem laboratory in the CLP conducted all of
the organic analytical procedures on the water samples; Volatile
organic analyses (VOAs), extractable organic compounds, pesticides,
herbicides, and dioxin. California Analytical Laboratory in the
CLP conducted the inorganic analyses on the seep and soil samples.
Western Research Institute in the CLP conducted the organic
analyses on the seep and soil samples. The DHS laboratories in
Berkeley conducted the analyses for the organolead and radionucliide
parameters in the ground water samples. Custody of the IT replicate
samples was tansferred to the IT on the day of or the day following
collection.
Sample Traffic Reports, Chain of Custody Forms, Receipts for
Samples, and photographs were used as part of the documentation
of the EPA sampling effort. Appendix D includes copies of the
all of the documentation paperwork. These forms are arranged in
chronological order. The photographs are on file EPA Region 9.
-7-
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MODIFICATIONS AND CLARIFICATIONS TO THE SAMPLE PLAN
The procedures presented in the Sample Plan, Appendix A,
were modified in the field at some sampling points. These modi-
fications are identified below by appropriate section of the
Sample Plan.
Section 1
Piezometer SB-3 was added to the wells to be sampled because
of a notation in the drilling log that grease had been found in
the soils during the boring of the piezometer.
Replicate samples were not collected from any wells for
analysis by California state agencies.
Section 2.1
A safety survey was not conducted at a number of the wells
as they were initially inspected. There was only one set of
survey equipment and two teams. The second team did the initial
inspections and depth to water measurements while wearing
appropriate safety gear. Later, prior to beginning the purge
process, the wells were monitored with the appropriate safety
equipment and a decision made whether the Investigation teams
could downgrade to Level D safety protection. A determination
was made that Level D was appropriate at each well.
Section 3.2
The wells identified below in Table 3 did not have 3 casing
volumes of water purged from them prior to sampling. Asterisks
indicate those wells which were purged dry.
Table 3: Wells sampled by EPA with less than 3 casing
volumes removed during the purge process.
2B 22* 47*
7* 29* 48*
8* 41* 49
10* 42* 50*
14* 43* 51
16* 46* SB3*
-8-
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The time lag between the completion of the well purge and the
collection the of volatile samples from the wells identified in
Table 4 was greater than 3 hours.
Table 4: Wells sampled by EPA with a time lag of greater
than 3 hours between purge completion and sample
collection.
7
14
41
43
48
49
50
51
SB3
All purge water was put into drums for later disposal by the
site operators at IT Panoche.
Section 4
Many of the wells at the site did not recover as expected.
a result full parameter sets could not be collected from them.
The wells from which organolead aliquots were collected are
identified in Table 5. The wells from which Appendix 8 aliquots
were collected are identified in Table 6.
AS
Table 5: Wells sampled by EPA which included aliquots
for organolead analysis.
1
2B
7
11
39
41
42
43
46
48
49
52
Table 6: Wells sampled by EPA which included aliquots
for Appendix 8 compounds.
1
4
7
11
16
17
31
46
49
Section 4.1
Replicate samples were not collected for state agencies
-9-
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Section 4.2
The field parameters of pH, temperature, and electrical
conductivity (EC) were not collected in quadruplicate at the
start and upon completion of sampling at wells 20, 47, 48, and 51
due to a lack of water.
The pH at well 9B was estimated using pH paper due to
equipment failure. Turbidity was not measured at wells 42 and 50
Section 4.4
The pH at all 7 of the seeps was estimated using pH paper.
Section 7.0
The only field equipment used for ground water sampling
which needed to be decontaminated on site was the water level
indicator (sounder) and the PTFE-coated stainless steel cable
used with the bailers. As the lines were drawn out of the well
they were wiped with a Kimwipe* soaked with Hexane followed with
a Kimwipe* soaked with distilled water. The tip of the sounder
was rinsed with Hexane and distilled water at the completion of the
wipe. The cable and the sounders were stored in plastic bags
between sample* points.
Decontamination of the field equipment used in the seep and
soil sampling followed the proceedures in the "Revised Draft
Protocol For Ground-Water Inspections At Hazardous Waste Treatment,
Storage And Disposal Facilities."
Special Problems
Well 9B
VERSAR'a PTFE bailer came untied and fell to the bottom of
the well. The bottom section of the bailer with the check ball
broke on impact and separated from the rest of the bailer. All
components of the bailer were retrieved by VERSAR using fishing
hooks and nylon fishing line.
Well SB-3
VERSAR1s PTFE bailer came untied and fell to the bottom of
the well. The entire bailer was retrieved as one unit by VERSAR
using fishing hooks and nylon fishing line.
-10-
-------
VALIDITY OF DATA BASED ON FIELD CONDITIONS
The volatile organics data from samples collected from the
wells identified in Table 4 could be biased in a negative
direction due to the time elapsed between the completion of the
purge and the initiation of the sample collection.
-11-
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ATTACHMENT B
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ATTACHMENT B
U.S. Environmental Protection Agency
Region 9
Hazardous Waste Ground Water Task Force
IT PANOCHE
GROUND WATER SAMPLING AUDIT
Peter Rubenstein
December, 1986
-------
TABLE OP CONTENTS
Page
Introduction 1
Review of IT Panoche's
May, 1986 Sampling Effort 2
Review of IT Panoche's
Sampling and Analysis Plan 12
Actual Nay 1986 Sampling vs.
the Sample and Analysis Plan Protocols 18
Review of ERG's and Engineering Science's
Documentation 18
Recommendations • 19
Appendix 1: Photographs
NOTE: The appendix 1 is not included in this report
It is available in the E.P.A's file.
-------
INTRODUCTION
A Sampling Audit was conducted at the International
Technology Corporation Panoche Facility (IT Panoche) by the EPA
from May 1 through May 15. Samples were collected by the IT
Environmental Monitoring Team (EMT) and analyzed by the IT labo-
ratory in Pittsburg.r PA, the ERG Laboratory in Emeryville, CA and
the Engineering Science Laboratory in Berkeley, CA. Visits were
made to ERG and Engineering Science as part of the sampling audit
process to review the sample handling procedures and documenta-
tion provided by the laboratory.
The sampling audit is divided into five major sections: A
descriptive review of IT Panoche1s May 1986 sampling effort; a
review of IT Panoche's sampling and analysis plan; a comparison
of the actual May 1986 sampling effort vs. the sampling and
analysis plan protocols; a review of the ERG and Engineering
Science documentation; and recommended changes which should be
made to the sample and analysis plan and the actual protocols
being followed.
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-2-
IT PANOCHE'S MAY, 1986 SAMPLING EFFORT
Overview of the May 1986 Sampling Effort
Forty-five samples, plus 1 duplicate and 2 blanks
were collected by IT over a 10 day period. EPA representatives
observed all of the initial soundings and the the purge and
sampling at 14 monitoring wells. The purging of the wells was
initiated by IT from 1 to 2 days prior to sampling. The moni-
toring wells' were purged with submersible centrifugal pumps or
bailers and sampled with bladder pumps or bailers.
The sample containers for coliform and for hexavalent chro-
mium, Cr (VI), were provided by ERG (Engineering Science provided
the autoclaved coliform containers to ERG). All of the other
containers were provided by the IT Pittsburg laboratory. Preser-
vatives were added to the empty containers by the laboratories
before sending them to the facility.
Depth to water (DW) was measured at all wells on May 1 and 2
prior to initiation of the purge sequence. The centrigual pumps
and bailers used to purge the wells were decontaminated before
their use at the sampler's staging area on site.
After all of the sample containers were filled the field
water quality parameters were measured*. Temperature, specific
conductivity, and pH were measured in quadruplicate at each
sample point. Depth to water was measured at each point at the
completion of sampling. The sample containers were put into
coolers under ice and stored. The coliform and Cr (VI) samples
were hand carried to ERG on the day of sampling. The other
samples were repackaged for shipping the same day or the
following day by Federal Express.
This part of the audit report is divided into two major
sections; field documentation and sample collection.
FIELD DOCUMENTATION
Sample Labels
The sample containers were pre-labled by the laboratory as
to project name, project number, parameters, preservative, and
the filtering status. The field personnel filled in the sample
location, boring/well number, collectors name, and date (see
Figure 1). The parameters which had more than 1 bottle were
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-3-
TOC/TOX, collected in quadruplicate, extractable organics col-
lected in 2 bottles, anions and cations collected in 2 bottles,
and the The "Bottle of " section of the label was never
filled in.
Figure 1:
Project Name
Sample Location
Boring/ Well No._
Collector's Name
Sample Type: —
^^^M
Parameters
RftttU
IT CORPORATION
Prnjoct No
nat«
Ground Water Surface Water
Soil Sludge/Waste
_ Pr^flfwativa
nf Fi|t^rq4 Nonfilterffd
Sample Labels for parameters being analyzed by IT
Pittsburg
Field Logs
The IT EMT recorded initial water levels on an "IT Benicia
Facility Water Levels" worksheet (see Figure 2). Other field
notes were kept on a "Sampling Information Form" (see Figure 3).
The completed forms for the Nay 1986 sampling event, document
ITP-007K, are with the site investigation files in the Regional
Office.
The recorded time for the DTK measurements, purge sequence,
sample collection, and field water quality data collection was
not identified as to time initiated or time completed. The
calculated purge volume for each well was recorded on the upper
left corner of the approprite Sampling Information Form.
The formula and coefficients used to determine the purge
volume for each well are not given on the form nor in the Sample
and Analysis Plan. The depth to bottom values for calculating
the purge volume are not included on the data sheet.
A separate Sampling Information Form was not filled out for
the blanks or duplicate samples. However, the data sheets for
the wells at which they were collected have notations indenti-
fying them as the point of collection for that QC sample.
Chain of Custody/Sample Analysis Request
IT maintained a "Sample Identification/Field Chain of
Custody Record" for each sample set collected at a sample point
(see Figures 4 and 5). The sampling point was identified by well
number and type of QC sample. The 8 digit Field ID # identified
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-4-
IT BENICIA FACILITY WATER LEVELS
Job Number:
WELL DATE TIKE DEPTH' *" ELEVATION BY COMMENTS
MW-
MW-
MW-
MW-
MW-
MH
MW-
MW-
MW-
MW-
MW-
MW-
MW-
MW-
MW-
MW-
MW-
MW-
MH-
MW-
MW-
MW-
MW-
MW-
MW-
MW-
(1)Measured from index mark at top of PVC casing.
Figure 2: Data Sheet used by IT for recording waterlevels in
the monitoring wells prior to purge.
-------
-5-
FIGURC £-2
SAMPLING INFORMATION FORM
sm _ ** "°'
WELL ,
STATIC HATER LEVEL Depth*A> Date and Time By
EVACUATION
Set Pump I • ._ Oate and Time
Volume (gal) Oate and Time ty Appearance
Purge 1 __________
Purge 2 ______________
Purge 3 _____________
Pull Pump: Oate and Time By
SAMPLING
Set Pump I Oate and Time
FIELD WATER QUALITY DATA
Meter type Serial *
Appearance Odor
pH Specific Conductance
T1«e Hcter Reading Units
Temperature *C
WATER LEVEL Depth*1) Oate and TU
COMMENTS
from index nark at top of PVC casing.
Figure 3: Data sheet used tor record purge and sample collection
information.
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-6-
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the date awd time of collection (month » first 2 digits, day «
second 2 digits, time * last four digits).
The sampling crew made sure to sign over custody of the
samples from individual to individual as the work progressed,
including the individual who packaged the samples for shipment.
Physical custody of the samples was maintained in an adequate
manner.
Separate forms were filled out for the QC blanks and duplica-
ates. The wells at which these samples were collected are
identified on the forms but the type of QC sample is not.
FIELD WORK
Purge
A Water Level Indicator* was used to measure depth to water
at all of the wells (see Photo 1). The sounder calibration was
not checked as the equipment had been purchased just prior to the
sampling event. The depth to water was measured at all wells on.
Hay 1 and 2. The EMT used those measurements in conjunction with
the depth to bottom of the well design specifications to calcu-
late the casing volumes to be purged from each well. Depth to
bottom was not measured during the sampling event.
The wells were purged with submersible centrifugal pumps or
bailers (see Photos 2 and 3). The purge volume at each well was
measured using a 5 gallon bucket. The purge water was placed
into 55 or 30 gallon drums for later disposal by IT Panoche.
The EMT purged 5 casing volumes whenever possible to comply
with State of California Katz Act. Host of the wells had to be
purged in 2 or more episodes to remove the desired volume.
Sample Collection, Handling, and Preservation
All of the samples were collected using freshly decontami-
nated ISCO bladder pumps or teflon bailers (see Photo 4). The
cable which was used to raise and lower the sampling pumps was
not disposed of after sampling. Instead, it was decontaminated
with the pump or bailer and reused.
The bladder pumps were set just above the bottom of the
well, in the screened interval. The samples collected by bailer
were always collected from just below the water surface which,
for some wells, coincided with the screened interval.
The first 2 complete pump volumes were used to rinse the
bladder pumps prior to sampling. The first three bailer trips
-------
-9-
were used to rinse the bailers. The samples were then collected
with the general mineral aliquot collected first and the various
volatile organic aliquots collected last. The other sample
containers were not filled according to any predetermined
sequence. Table 1 identifies the sample aliquots and special
handling followed for each parameter.
The sample bottles were filled over a drum or bucket to
prevent potentially contaminated groundwater from being poured to
ground A perforated drum cover was used to support the sample
containers while they were being filled, generally over the drum
with the purge water (see Photos 5 and 6). There is a potential
for contamination of the TOX sample when samples are collected
over water containing contaminants. Occasionally empty and
filled bottles were set on the drum cover in spilled water and
were not adequately wiped off prior to packaging.
Extractable organic samples were occasionally collected in
clear bottles.
The TOC/TOX sample, which was collected in one container was
preserved with ^28203. The two parameters should be collected
in separate aliquots, placed in separate containers, and preser-
ved appropriately.
The metals samples were collected through an inline filter
utilized for that parameter only (see Photo 6). The filter
holders were decontaminated prior to use and a fresh filter was
put in place for each sample.
was used as a preservative for all of the organic
parameters. Its use is only appropriate when the sample contains
residual chlorine. None of the samples collected from IT Impe-
rial monitoring wells should contain residual chlorine.
The TOX sample should be the first parameter collected, not
the last, to minimize aeration effects.
All of the samples were cooled with blue ice immediately
after they were collected. The amount of blue ice used was not
always sufficient to keep the temperature of the samples down.
Field Parameters
After all containers were filled at a well, a Martek Mark X*
was used downhole to measure temperature, specific conductance,
and pH (see Photo 7). The parameters were measured in quad-
ruplicate and recorded on the field data sheets. One direct
reading of electrical conductivity, normalized to 25° C, was also
measured and recorded on the data sheets.
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-10-
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All of-the probes were calibrated daily prior to sample
collection according to the protocols given in the Martek ins-
truction manual* The pH probe was calibrated with buffer solu-
tions of pH 4 and 7. The sensor for conductivity was calibrated
with a 6680 umho KC1 solution The temperature sensor was checked
against a lab thermometer. The calibration information was
recorded in a calibration log kept at the equipment storage area.
Packaging
The coliform and Cr (VI) containers were set on ice and hand
carried to E-RG on the day of sample collection. The other sample
containers were iced as they were collected and repackaged in
vermiculite and re-iced on the day of shipment, the day of or the
day following sample collection. The samples were kept together
by and well and were accompanied by the Sample Identification/
Field Chain of Custody Record.
Decontamination
The EMT decontaminated their sampling equipment at their
staging area on the Panoche site (see Photos 8 - 10). The
plywood wash area was inadequate because the wood platform used
as a work area could never be properly decontaminated, even with
steam cleaning, and the water ran off into a roadside ditch which
empties into a runoff collection pond.
Subsequent to the sample audit, IT Panoche has constructed a
concrete wash/decontamination station for the EMT which will
enable them to clean their equipment while minimizing the poten-
tial for cross contamination of equipment as well as minimize the
movement across the site of contaminants in the wash and rinse
water.
A number of inadequacies in the IT decontamination process
were identified during the audit. Braided cables and ropes were
used for raising and lowering the bladder and submersible pumps.
The braids can not be completely cleaned. The exterior of the
hoses and cables for the pumps were steam cleaned while they were
coiled on spools. This prevents the inner coils from being
adequately decontaminated. The final distilled water rinse of
the sampling equipment was poured from a 5 gallon water bottle.
It was not directed by a nozzle or hose. This can lead to
inadequate rinsing of the equipment, especially to coiled lines
and hoses.
Fresh lengths of silicon tubing were cut and decontaminated
at the wash area for use in the ISCO pumps (see Photo 11). Crude
measurement of the silicon tube and rough knife cuts led to
occasional leaks in the bladder pumps in the field.
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-12-
REVIEW OF SAMPLING AND ANALYSIS PLAN
The Groundwater Sampling and Analysis Plan IT Corporation
Benicia Facility (dated 1/17/85), Attachment 4 to the
IT Panoche RCRA Part B application, was identified by the IT
samplers as their Sampling Plan.
The EPA review of the sampling and analysis plan follows
the organization of the plan itself.
Cleaning (Section 3.0, page 2)
This decontamination section does not include a discussion
on the decontamination of cables and lines used to haul the pumps
and bailers. There should also be discussion on the decontamina-
tion of the interior of the bladder pumps and the water lines.
Transportation and Storage (Section 3.2, page 3)
The section discusses newly cleaned PVC cases for transpor-
ting and storing pumps. There should be a discussion in the
section above on how the cases will be cleaned.
Evacuation of Well (Section 4.0, page 3)
This section mentions redevelopment of the wells if the
purged water is noted to be "highly turbid". More discussion is
required on how the determination will be made that the water is
so highly turbid that redevelopment of the well is necessary.
The "standard well development techniques" which will be used
need elaboration.
The use of a "gator" truck for well development needs to
be discussed more fully.
Eighteen hours is too great a time lag between purge and
sample collection. The EPA recommended maximum time lag is 3
hours. The pump used to collect the samples should be the same
used to evacuate at least the last casing volume from the well.
The purge, of at least the last casing volume should be at
a rate of flow which will match the well's recharge rate if it
is practical.
Volatile organics should be collected as soon as possible
after the completion of the purge.
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-13-
Monitorinq Well Water-Level Measurement (Section 5.1, page 4)
It will take more than 2 hours to take all of the measure-
ments at the site.
Well depth should be measured in addition to water level
prior to the purge. This is dicussed in Appendix C but not in
this section.
A second water level measurement should be taken at imme-
diately prior to sampling. The information gained from water
level measurements taken after sampling is not as useful.
Appendix C discusses the collection of water level measurements
prior to sampling. This conflicts with Appendix C.
The calibration of the "calibrated electric probe" should
be checked on a routine basis. The calibration schedule should
be identified in the Sampling and Analysis Plan. A calibration
log should be kept with the equipment or in the field notes for
the sampling event.
The use of "clean water" for the triple rinse of the probe
is not specific. The water type should be identified, i.e.,
distilled, deionized, or HPLC water.
Pump and Bailer Setting (Section 5.2, page 5-8)
The samples should be collected from the screened interval
regardless of whether a bailer or a pump is used.
A teflon coated stainless steel cable can be cleaned between
wells. Other materials should be discarded between sampling
points to prevent cross-contamination.
Appendix B does not include a Sampling Information Form. It
is given on page 6. There is no place on the form for electrical
conductivity normalized to 25* C.
Filling Sample Containers (Section 5.3, page 8-10)
Organic samples (volatiles, extractables, phenols, TOC, and
TOX) should be collected first, before major anions and cations,
especially when there might not be enough water to collect the
full parameter suite.
The rationale for when to rinse and when not to rinse sample
containers should be presented, either as an overall statement or
on a parameter by parameter basis.
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-14-
This section should include a reference to Table A-l rela-
tive to sample containers and preservation techniques.
The rationale for when to overfill, fill to the top, or
leave head space in the sample containers should be presented in
an overall statement or on a parameter by parameter basis. The
phrases "completely filled" or "filled completely" are not
precise enough. The Plan should state when containers will be
filled with no headspace, to the brim, or to the shoulder.
The rationale for when samples should be acidified in the
field should-be presented in an overall statement or on a para-
meter by parameter basis.
Phenols are listed in Table A-2. They should also be iden-
tified in this section and in Table A-l.
The only parameters identified in Section 5 which have
containers prepared with preservatives are cyanide, TOC/TOX and
sulfide. This is not consistent with Table A-l which identifies
preservatives for sulfide, trace metals, cyanide, TOC/TOX,
extractable organics, radium, gross alpha and gross beta,
nitrates, and coliform.
Based on the discussion in Section 4.0 turbidity is expected
to be a problem at some of the wells. It should be a parameter
which is measured in the field or at the sampling team's staging
area.
Trace Metals (Section 5.3.2, page 9)
These should be identified as dissolved (or filtered) trace
metals. The Plan should identify whether the samples will be
filtered in-line or with a vacuum.
The Plan notes that samples might have to filtered in the
IT Martinez laboratory if the turbidity is too great. The plan
should clarify whether or not the samples will be acidified prior
to filtration. If not, the Plan should specify what the interme-
diate sample container will be.
Non-Volatile Organics (Section 5.3.4, page 9)
The samples should be protected from sun light. Use of
amber bottles or aluminum foil around the bottles is recommended.
Cyanide (Section 5.3.6, page 9)
Table A-2 includes a discussion on the use of lead acetate
paper to determine if cadmium nitrate powder is needed to remove
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-15-
sulfide from the water. This should be discussed in greater
detail in the text.
Total Organic Carbon/Total Organic Halogens (Section 5.3.7,
page 9)
This section implies that TOC and TOX will be collected in
separate containers. Table A-l indicates that they will combined
in one container. They should be kept separate. TOX should be
placed in an amber bottle without preservatives and eliminating
head space. , TOC should be preserved with HC1 or
Field Water Quality Measurements (Section 6.0, page 10)
The plan should detail how the data will be collected when
downhole measurement is not possible.
Collection of Replicate Samples for Indicator Parameters (Section
7.0 .page 10-11)
This section of the Plan implies that TOC and TOX will be
collected in separate containers. Table A-l indicates that they
will be in the same container. They should be in separate con- .
tainers (see comments for Section 5.3.7)
The plan should identify the frequency at which the pH and
conductivity meter will be calibrated. A calibration log should
be kept with the equipment or in the field notes for the sampling
event.
Collection of Duplicate and Blank Samples (Section 8.0, page 11)
The use of travel blanks when volatile organic samples are
shipped is suggested.
Duplicate Samples (Section 8.1, page 11)
The use of a "unique identification number" implies that the
duplicate samples will be "blind" to the laboratory. This should
be stated explicitly one way or the other.
Field Methods Blank (Section 8.3 page 11)
The plan discusses the collection of a field methods blank
when the regular groundwater samples are only collected with a
submersible bladder pump. There is no discussion on the collec-
tion of the blank when regular sampling utilizes a teflon bailer.
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-16-
Sample Identification (Section 9.0, page 12)
Duplicates and blanks will not be blind samples according to
this numbering system. This may lead to QA/QC difficulties.
Sample Preservation (Section 10.0, page 13)
Each sample container should be placed in the ice chests as
soon as it is filled and not after the whole set as been filled.
This should be more explicit in the Plan.
Analytical Procedures (Section 12.0, page 14)
A regular schedule for calibration of the field instruments
should be identified in the Plan. This includes the probes used
for collecting water level measurements.
APPENDIX A
Table A-l
Trace metal samples should be acidified after filtration.
The acid used should be stated.
TOC and TOX samples have differing preservation requirements
and should not be placed in the same container with the same
preservative. TOX should be placed in an amber bottle without
preservatives and without head space. TOC should be preserved
with HC1 or H2SO4.
Extractable organics should be protected from sunlight. Use
of amber bottles or aluminum foil around the bottles is recom-
mended. Sodium Thiosulfate is not necessary as a preservative
with these samples. The Plan does not identify who adds preser-
vatives to this parameter.
Phenols are listed in Table A-2. They should also be listed
in Table A-l and Section 5.3.
APPENDIX B
Sample Identification (Section 1.0, page B-l)
There is no place on the form for specifying the preserva-
tion method utilized for eachparameter.
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-17-
Chain-of-Custody (Section 3.0, page B-3)
the use of custody seals or evidence tape to demonstrate
that the integrity of the samples has not been compromised should
be discussed in this section.
APPENDIX C
The material in this appendix either duplicates material
already included in the text or contradicts material in the text.
Section 1, Page C-l
This section calls for water level measurements prior to
sampling. Section 5.1 discusses the collection of water level
measurements after sampling. Appendix C conflicts with Section
5.1 of the text.
A stinger and vacuum truck should not be used to purge a
well.
Section 2, page C-l
The protocol for manual purging calls for purging until EC
has stabilized. The protocol for pump purging calls for the
purging of three casing volumes or until the well is completely
evacuated. The sample plan should discuss why there are sepa-
rate criteria for the two methods.
Section 3, pages C-l to C-2
The possibility of contaminants entering the well due to the
use of a stinger for purging is great enough that it should not
be considered as an acceptable purge method.
Section 4, page C-2
This section duplicates material already presented in the
Plan and is unnecessary.
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-18-
COMPARISON OP THE MAY 1986 SAMPLING VS.
THE SAMPLE AND ANALYSIS PLAN
The IT Environmental Monitoring Team follwed the Sampling
and Analysis Plan during the entire sampling effort with no
significant discrepencies noted.
REVIEW OF ERG'S AND ENGINEERING SCIENCE'S DOCUMENTATION
ERG, Emeryville is responsible for the analysis of Cr VI and
coliforms. Both parameters have short holding times. ERG has
contracted out the coliform work to Engineering Science in
Berkeley. As part of the sample audit the EPA visited ERG and
Engineering Science and reviewed the sample tracking and documen-
tation procedures used there.
Both the coliform and the Cr VI samples come to ERG with
notations as to the site and well number. The coliform samples
are renumbered with using an ERG numbering system and sent to
Engineering Science as blind samples.
Chain of Custody
Custody of all of the samples, which arrived at ERG, were
transferred with appropriate signatures on IT's chain of custody
records. Chain of custody was not documented for the coliform
samples which were then transfered to Engineering Sciences.
Hold Times
i
Hexavalent chromium has a 24 hour hold time. ERG begins its
analysis immediately upon receipt of the sample which prevents
the hold time from being exceeded.
Coliforms have a 6 hour hold time. Engineering Science sets
the samples in the incubator within shortly after receipt from
ERG. Engineering Science is not told when the sample was collec-
ted, does not always record when the sample was received nor when
it is placed into the incubator. The method hold times might
easily be exceeded by the time the coliform samples are placed
into the incubators. It would be difficult to determine based on
the records kept by Engineering Science.
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-19-
SUMMARY OF RECOMMENDATIONS
Field notes should identify all values used to calculate purge
volumes.
The electrical water level sounders, should be calibrated on a
regular basis.
Well depth should be measured prior to purge on all wells where
there may be a silting problem.
Braided ropes and cables used to raise and lower the pumps and
bailers can not be properly decontaminated between wells. They
should be used one time only or replaced with a cable which can
be adequately cleaned.
The silicon tubing used in the bladder pumps should be more
carefully cut and placed on the pumps.
Samples should be collected at the screened interval whether the
sample is collected with a pump or a bailer.
The volatile parameters should be collected as soon as possible
after the completion of the purge to minimize the loss due to
volatilization.
Extractable organic samples should be collected in amber bottles
to minimize the effects of sunlight.
TOC and TOX samples should be collected in separate containers.
N32$203 should not be used as a preservative in any of the
organic samples collected at this site.
The sample and analysis plan needs to be revised and updated.
The laboratories doing coliform and Cr+6 analyses for IT Panoche
should document date and time when the analyses are initiated
and completed. Chain-of-custody should be documented for the
conform which are transferred from one lab to another.
-------
ATTACHMENT C
-------
ATTACHMENT C
U.S.,Environmental Protection Agency
Region 9
National Ground Water Task Force
IT PANOCHE
LABORATORY AUDIT REPORT
Kevin W. Wong
September, 1986
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PART I
OFF-SITE GROUNDWATER ANALYSES LABORATORY
IT ANALYTICAL SERVICES
-------
INTRODUCTION
On May 12-13, 1986, a laboratory audit was conducted at IT
Analytical Services Laboratory (ITAS) in Export, PA, in support
of the Hazardous Waste Ground Water Task Force site investigation
at IT Panoche. The ITAS Lab is a commercial laboratory owned
and operated by the IT Corporation. As such, this laboratory
performs the majority of ground water analyses required of all of
IT RCRA sites in the nation. In particular, essentially all of
IT Panoche'.s groundwater samples are submitted to the ITAS Lab
for inorganic (except chromium +6 and coliform) and organic
chemistry analyses.
The major objectives of this audit were twofold: 1) To assess
the ITAS Laboratory's capabilities to conduct ground water
analyses, as well as their general ability to produce data of
acceptable quality, and 2) to investigate and assess the quality
of actual groundwater data generated specifically for the IT
Panoche site.
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II. OVERVIEW
The laboratory audit was conducted in three phases, as
discussed below.
The initial objective of this audit was to conduct an infor-
mation gathering session with laboratory management, at which
time the definitive purpose of the audit was explained. As an
integral aspect of the audit process, the laboratory director was
requested to describe the general organizational structure and
primary operations of the laboratory, including such factors as
the history of the laboratory, their overall analytical capabi-
lities, the credentials of key laboratory personnel, the descrip-
tions of analytical instrumentation, the extent of the labora-
tory's quality assurance/quality control (QA/QC) program, and the
laboratory's relationship with the IT Panoche Facility. To
substantiate the accuracy of the verbal information provided, all
relevant documentation describing these processes were requested,
and subsequently acquired. These documents are provided as
attachments to this report.
The next phase of the audit consisted of a comprehensive
walkthrough of the laboratory. At this stage, a number of inves-
tigatory steps were followed, including such activities as 1)
directing specific questions on various aspects of each organiza-
tion component of the laboratory to section supervisors and key
analysts, 2) recording visual observations of operational analy-
tical instrumentation, 3) reviewing laboratory bench and QA/QC
records, 4) noting general impressions of routine laboratory
operations, and 5) conducting follow-up interviews with key staff
and managers in order to acquire answers to specific areas requi-
ring clarification.
pnce all observations had been recorded and notes compiled,
and all requested documents received and reviewed, an exit
debriefing with management was conducted to discuss and summarize
all significant areas of concern. The primary intent of of this
exit interview was to identify those areas determined to be most
in need of improvement or upgrading, and to provide constructive
suggestions for rectifying deficiencies.
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DEFICIENCIES
QUALITY ASSURANCE PROGRAM
The quality assurance (QA) program in place at the time of
this audit was in general, adequate. There were, however, speci-
fic areas which were determined to be marginally acceptable.
These areas are summarized as noted below.
Documentation
There exists a noticable inconsistency in the manner in which
quality control data is monitored and maintained. This was
reflected by the lack of documentation regarding quality control
charts, temperature records and standard curves. Some of these
deficiencies may become self-correcting once the laboratory
establishes a centralized computer system. However, until such
time when this system is established and implemented, it is
recommended that the laboratory improve its method of QA record-
keeping and data documentation. It is likely that an improvement
in the mechanics and process will result in an easier transition
to a computerized system.
QC Acceptance Limits
The laboratory has not formally established QC acceptance
limits for surrogate/matrix spike recoveries or duplicate sample
analyses. At the time of this audit, the laboratory had only
been utilizing those limits established for EPA QC samples, or
had generally been attempting to use those limits established in
EPA's Contract Laboratory Program (CLP). Although the use of
these EPA limits is acceptable, it is still recommended that the
laboratory establish its own limits based on its own historical
analytical data base. The laboratory's direction toward establi-
shing a computerized data base will be quite helpful in retrieving
and manipulating data, and therefore should serve as a useful
tool in establishing data acceptance criteria.
SAMPLE RECEIPT AND STORAGE
Sample Storage
The laboratory does have by its own admission a significant
sample storage problem. The volume of analyses has created quite
a burden on sample management personnel, in attempting to main-
tain available storage space. At present, there is no separate
storage space dedicated to enforcement confidential or enforce-
ment sensitive samples. For purposes of proper chain-of-custody,
it is recommended that the laboratory explore the possibility of
allocating secure storage space for these type of samples. The
laboratory also does not currently have a specified containment
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area for samples received in a leaky condition, or for those
samples containing relatively high concentrations of chemical
contaminants. I was informed by laboratory personnel that con-
tainment hoods might be established in the future. Such an
addition would be helpful in protecting worker safety and in
minimizing the chances of laboratory-wide contamination. One
last area which could be improved involves the need to establish
a traceable QA/QC system for sample containers. Based on the
information provided by laboratory personnel, it does not appear
that the laboratory has a mechanism for tracing potential sources
of sample container contamination back to specific batches. It
is therefore recommended that the laboratory establish a system
for recording batch numbers of sample containers purchased through
their supplier, as well as a routine for conducting QC analyses
on random blank bottles.
GENERAL OBSERVATIONS
The laboratory in general appears to be well organized,
suitably equipped with adequate instrumentation, and staffed by
capable professionals. Management is quite knowledgable on an-
alytical procedures applicable to various environmental programs,
and has demonstrated an attempt to ensure that all staff also
become aware of these requirements. Management also appears to
display a conscientious effort to incorporate the appropriate
degree of QA/QC activities for each project, as was reflected in
the supervisors' routine practice of conducting daily project
update meetings. Certain instrumentation used in inorganic anal-
lyses (AAs and ICP) and organic analyses (GCs and GCMSs) are
"dedicated", and thus are used only for specific types of anal-
yses. In addition, the laboratory also has a number of backup
instrumentation in the event that primary instrumentation is not
available. The IT Corporation appears to have in place an exten-
sive external QA program, which also serves in ensuring that all
IT laboratories uniformly follow standard QA/QC practices.
- 4 -
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CONCLUSIONS
The laboratory generally has a number of QA/QC areas which
need to be modified or improved upon. Although none of these
areas will singularly jeopardize the quality of data generated by
the laboratory, it is conceivable that, in combination, they can
cause significant problems. It is therefore strongly recommended
that these concerns, as previously noted, be addressed and correc-
ted at the earliest opportunity. First and foremost, laboratory
management must finalize and implement their QA plan. Second,
the laboratory should accelerate its development of a centralized
computer program, and develop QC data acceptance limits. Lastly,
documentation of records needs to maintained and reviewed. In
summary, if the laboratory continues to maintain it current
standard of operation, positive attitude, and initiates the
recommended corrective action, it is expected that the laboratory
can satisfactorily analyze groundwater samples and generate data
of acceptable quality.
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PART II
-OFF-SITE HAZAFDOUS WASTE ANALYSES LABORATORY
IT VINEHILL LABORATORY
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I. INTRODUCTION
The IT Panoche facility utilizes an off-site laboratory
for the analyses of all hazardous waste samples prior to accep-
tance. These pre-disposal analyses are conducted by the IT
Vinehill laboratory located in Martinez, CA, to ensure that the
chemical and physical characteristics of the hazardous waste
loads are suitable for disposal at the Panoche site. The focus
of this audit was to determine whether these pre-disposal
analyses have been performed correctly, and to ascertain if the
laboratory has been following proper analytical and quality
assurance procedures. This audit did not concentrate on truck
receiving analyses specific to the operation and waste management
activities of the IT Vinehill facility. In conjunction with a
concurrent investigation by EPA's National Enforcement Investiga-
tion Center (NEIC), this audit was conducted in two phases over a
duration of three days. The first phase involved a discussion of
the availability of relevant laboratory documentation, the
applicability and accuracy of the facility's Waste Analyses Plan,
and other administrative matters. The second phase consisted of
a walkthrough of the laboratory, a discussion of analytical
methods, and a visual assessment of analytical instrumentation.
Specific comments and deficiencies regarding these activities are
summarized in subsequent sections of this report.
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.1. DEFICIENCIES
QUALITY ASSURANCE PROGRAM
In general, the QA program in place at the time of the audit
was adequate. There were, however, specific areas which were
determined to be deficient. These areas are summarized as noted
below.
Analytical Procedures
There appear to be a number of circumstances where the lab's
analysts depend on "best professional judgment" in conducting
analyses and assessing data. Although this approach may in most
instances be technically sound, the lab should have specific
documentation (i.e., standard operating procedures, procedural
guidance, etc.) to substantiate their decisions. Although a number
of lab analysts were interviewed, it was not entirely clear
whether the lab had established and followed a specific "decision
tree" process in conducting their analyses. As an example, there
were instances where the analytical procedures described by
particular analysts or section supervisors were actually incorrect
or inaccurate. Specifically, the spot test procedure described for
cyanide analyses was not consistent with the method sequence cited
within the laboratory's QA plan, and there was some confusion as
to how and why hydrocarbon vapor pressure (HCVP) hexane equivalents
correlate to ignitability criteria. These discrepancies may only
be reflective of one specific area within the lab (i.e., truck
receiving analyses) and not be characteristic of the lab's overall
capabilities, but nevertheless should be investigated as an area
needing improvement.
Discrepancies were also noted in the area of inorganic metals
analyses. At present, the lab .does not establish a multi-level
calibration curve during atomic absorption analyses (although this
is done for ICP analyses). As a result, it is unlikely that
linearity can be established over a certain calibration range,
and therefore questions regarding the accuracy of reported concen-
trations might be raised. It is therefore recommended that the
lab establish at least a three-point calibration curve and attempt
to "bracket" a concentration range.
Standard Operating Procedures
In terms of QA documentation, the IT laboratory has developed
a corporate-wide QA plan as well as a QA plan specific to the
operation of the Northern California (IT Vinehill) Laboratory.
However, it was not clearly apparent that all of the laboratory
personnel were familiar with the QA requirements outlined in
either of these documents. As an example, when questioned on the
existence of standard operating procedures (SOPs) for such areas
as truck sample receiving, pre-disposal receiving and glassware
washing, personnel could not readily refer to an existing SOP.
-------
In order that proper procedures are followed in a consistent
manner, it is recommended that management ensure that laboratory
personnel are routinely trained in familiarizing themselves with
changes in laboratory QA operations. This could be accomplished
via the use of formal training sessions, or through internal
a ud i t s.
[I. CONCLUSION
As stated previously, the focus of this audit was to ascer-
tain whether the IT Vinehill Laboratory has been conducting
pre-disposal analyses correctly, and to determine if data gene-
rated for the IT Panoche facility is of adequate quality. In
these terms, it is felt that this laboratory has the appropriate
instrumentation, adequate facilities and qualified personnel to
satisfactorily conduct pre-disposal analyses. With the exception
of certain deficiencies noted earlier, the laboratory generally
utilizes the correct analytical procedures for pre-disposal
analyses. Conceptually, the QA program is appropriately compre-
hensive and quite detailed. However, although the laboratory is
organizationally stable and has established a technically sound
foundation, it is apparent that a number of deficient areas need
to be addressed. Specifically, management needs to better dis-
eminate their technical expertise and QA philosophy to all
laboratory staff. Also, there appears to be a lack of consis-
tency in the manner the laboratory conducts pre-disposal analyses
versus truck receiving analyses. This was clearly apparent based
on the discrepancies in truck receiving analyses summarized in
EPA's NEIC RCRA Compliance Inspection Report (Sept. 1986).
Lastly, greater emphasis has to be placed on ensuring that proper
documentation is maintained throughout each facet of analyses.
If discrepancies are noted, the laboratory should establish a
mechanism to either resolve these differences, or have a system
to substantiate the rationale for supporting these discrepancies.
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PART III
ON-SITE WASTE ANALYSES LABORATORY
IT PANOCHE
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I. INTRODUCTION
On August 27, 1986, an audit was conducted of the on-site
waste disposal laboratory at IT Panoche. This laboratory is
responsible for performing confirmatory "fingerprinting" analyses
of all waste loads prior to acceptance and disposal at the facility.
Pre-disposal analyses are not conducted at IT Panoche, but rather
are the responsibility of the waste laboratory at IT Vinehill in
Martinez, California. This audit focused on the capability of the
IT Panoche laboratory to conduct the fingerprinting analyses
correctly.
II. FINDINGS
IT Panoche requires that pre-disposal analyses be performed
on each new waste load, or annually on those waste loads which
are submitted on a recurring basis by the same generator. RCRA
waste loads are typically bulk liquids received in vacumm trucks,
as containerized liquids are not accepted for disposal. The
laboratory performing these analyses is situated in a limited but
adequate space environment, and is essentially staffed by one
fulltime chemist. The chemist is responsible for managing the
operation of the laboratory.
As described by the chemist, the fingerprinting analyses
conducted"by the laboratory are consistent with the methods
identified in the facility's waste analyses plan. These methods
are quite standard, and include such tests as pH, acid or base
strength, density, and hydrocarbon vapor pressure determinations.
All aqueous phase samples are subjected to spot tests for cyanide,
sulfide, and phenols. Upon completion of the appropriate battery
of tests, the results are compared to the information generated
during the pre-disposal analyses. Waste loads are only accepted
if the chemist determines that the fingerprinting results reasonably
match that of the pre-disposal sample. If the loads do not match,
and are subsequently rejected, this information is then recorded
and documented.
III. CONCLUSION
Despite the relatively small scale of operation existing at
the IT Panoche facility, there still exists a very good standard
of work performed by the staff chemist at the laboratory. The
profiles of waste currently deemed acceptable for disposal at the
site are well defined by IT, therefore it is an unusual occurance
for the laboratory to receive a waste load which cannot be adequately
characterized. General laboratory practices are acceptable and
staff are well experienced. Based upon the findings of this audit,
fingerprinting data generated by this laboratory is expected to be
satisfactory specifically for the type of wasteloads presently
accepted at the site. However, should the quantity and profile
of future wasteloads increase or change as a result of expanded
disposal capacity at this site, then the lab should be re-evaluated
for any new additional screening analyses. In addition, these
modifications should be adequately and appropriately reflected in
a revised waste analyses plan.
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ATTACHMENT D
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\ UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
I WASHINGTON, D.C. 20460
OFFICE OF
POLICY, PLANNING AND EVALUATION
MEMORANDUM 27 March 1987
Subject: Review of the Statistical Methodology Proposed by International Technology
Corporation for the Panoche, California Hazardous Waste Disposal Site.
From: Barnes Johnson, Statistician
Statistical Policy Branch
To: Hannible Joma, Geologist
EPA Region IX
Hazardous Waste Ground-Water Task Force
The general sampling and statistical analysis approach, (specifically the interest in
obtaining "true" replicate samples and the use of Analysis of Variance (ANOVA)) offered by
International Technology Corporation (IT) are reasonable and should be encouraged. However,
the details of the ANOVA approach are unacceptable because upgradient concentrations are not
compared with downgradient concentrations and because differences among wells and individual
well comaprisons are not tested as part of the approach.
Lack of a Upgradient versus Downgradient Comparison
IT is proposing to use a method which does not consider contamination that might be
present in the ground-water before the ground-water flows under the hazardous waste
management unit (HWMU) of concern. A commercial facility, having many HWMUs under
independent evaluation and with possible relict contamination, risks triggering the IT proposed
test when there is no contamination emerging from the HWMU with a higher than expected
probability. Specifically, under the ANOVA testing scenario that IT has proposed (and that I
disagree with as discussed below) there may be a significant well by time interaction and
therefore a suggestion of contamination in the ground-water that actually has been caused by
external influences and not the HWMU. Upgradient ground-water concentration patterns.
although discussed, are not considered or evaluated in the proposed method and there may
actually be a "natural" well by time interaction that is not caused by the HWMU.
The only time that the upgradient data may not need to be considered is when there are
no upgradient concentrations of the indicator parameters measurable above the detection limit.
In this case, however, under the scenario of no leakage from the HWMU there are also few
downgradient concentrations above the detection limit which will make any conventional
ANOVA approach problematic.
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Lack of an Evaluation of Differences Among all Wells and Between Specific Wells
IT proposes an ANOVA based method which will indicate contamination when there is a
significant well by time interaction. In simple terms this means that the HWMU will trigger
when there is an indication that all wells do not behave in the same pattern relative to one
another over time. This concept is best expressed graphically. Figures 1A, IB, and 1C are
examples of hypothetical data that would trigger the interaction test proposed by IT. First
notice that in 1A, IB, and.1C the difference between wells 1 and 2 is not constant, therefore
the significant interaction. Also observe that in IA and IB there is question as to whether
there is actually contamination and if so in which well, maybe both wells, or maybe neither
well. In 1C it appears that well 2 is consistently greater than well 1 althought the difference
is decreasing (a plot similar to 1C, also with a significant well by time interaction, could have
been shown with the concentrations in wells 1 and 2 getting progressively farther apart). The
point is that a significant well by time interaction may or may not adequately indicate
contamination. Figure ID illustrates the situation where concentrations change over time but
the relationship between the wells does not change. In Figure ID there is not a significant
well by time interaction but well 2 could be contaminated. Figure IE demonstrates the most
startling scenario that might occur under the IT approach. In Figure IE there is clearly no
well by time interaction, however well 2 has consistently larger concnetrations than well 1.
Finally, Figure IF illustrates the situation where there is little or no interaction and probably
no statistically significant difference in concentration between the wells. The conclusion from
Figure 1 is that using a significant well by time interaction as the triggering threshold can
result in both false positives and false negative results at a higher than anticipated rate.
Suggestions for Improvement
As mentioned earlier the ANOVA approach is a reasonable construct for evaluating
contamination. However, IT has not gone far enough. Generally if a significant interaction is
not found then differnces among wells should be tested to guard against the situations in
Figures ID and IE. If no differences are seen among wells after finding no interaction then,
unless all the downgradient wells are contaminated, the site is probably not contaminating. If
there are differences among wells then differences between specific wells or groups of wells
should be evaluated, using contrasts or other such multiple comparison procedures, to determine
in which wells the contamination is located. If a significant well by time interaction is
found it is likely that at some time or at all times as illustrated in Figures 1A, IB, and 1C at
least one well has a larger concentration than the others. These can be evaluated by looking
at specific contrasts within the overall linear model. Plotting the data as illustrated in Figure
1 will help to focus the evaluation of specific well and time differences.
Finally, the attached article provides an ANOVA approach to the evaluation of environmental
change. The approach advocates the use of a before and after effect in the model which is in
some ways analagous to the upgradient/downgradient scenario in this situation.
attachment
cc: Mary Allen
John Warren
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WELL 1
WELL 2
I I
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Figure 1. Examples of Time Differences, Well
Differences, and Well by Time Interaction.
-------
ATTACHMENT E
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ATTACHMENT E
Chronology of Ground Water Enforcement Actions
Date Activity
March 1984 EPA conducts RCRA interim status inspections
May 1984 ., EPA notifies DHS & RWQCB of interim status
violations, including ground water monitoring
July 1984-- DHS refers case to the District Attorney for
Contra Costa County, Violations match EPA's
September 1984 EPA issues civil (administrative) complaint
to IT-Benicia for interim status violations,
including ground water monitoring
Many discussions with the EPA, State and IT occured during
this time period.
January 1985 RWQCB issues Cleanup and Abatement Order
No. 85-003, which supercedes the ISD ground
water monitoring waiver, orders compliance
with the Interim Status Document, and
requires assessment work.
July 1986 EPA and IT signed a Consent Agreement to
resolve the September 1984 complaint.
Ground water violations were withdrawn in
consideration of 1/85 RWQCB Cleanup and
Abatement Order.
September 86 RWQCB issues Cleanup and Abatement Order to
the Benicia facility to order further study
(assessment) of contaminant plumes in the
areas of surface impoundments 12 through 16,
surface impoundments O, P, and Q, and surface
impoundments 1 and 2. Monthly progress
reports to be submitted beginning January 1,
1987. Surface seeps in the area south of
ponds 1 and 2 are ordered to be contained
by November 14, 1986.
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ATTACHMENT F
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TABLES
-------
Table 1
Benficial Water Use In The Vicinity of IT Panoche Facility
(Source; Leroy Crandal And Associates, 1985)
Well No. Remarks
1 Evidence of old windmill at abandoned farm house. Stock pond
nearby.
2 Domestic Well (Stephen Thurlo, Box 2 Lake Herman Road, Benicia) -
Shallow dug well, 15* wide x 30' deep, stone and concrete lined,
wooden cover, no seal. Small electric submersible pump. Sampling
access OK. In swale near creek with heavy riparian growth.
3 Stock Well (neighbor said IT owned well) - 6* PVC casing with
electric submersible pump. Discharge to stock trough. 4"
open iron casing nearby, probably abandoned well. 2" lines,
gage shows 46 psi in pressure tank. Located in sandstone outcrop.
Has 3/4" or 1" measuring port in well cover, no pad, concrete
seal. No information on depth, age or construction.
4 Domestic Well (W.A. Brady. 1048 Lopes Road, Benicia) - Well
dug in 1867. It is stone lined with concrete collar and wood
. cover. No seal, 12' deep, about 10' across with electric pump
(10 gpm). Located in sag pond area within Green Valley Fault
Zone.
5 Gravel Pit Well (1060 Lopes Road, Benicia) - Neighbor reports it
to have been drilled in 1984 to a depth of 130 feet.
6 Domestic Well (Ben Villareal, no address, Lopes Road) - 8* drilled
well with steel casing. Electric submersible pump. No information
on depth. Approximately 22 years old.
7 Developed Spring (Harland Hall, Lopez Road. Benicia) - Well about
100 years old.
8 Quarry Well - Reported to be drilled about 5 years ago.
Unlocated Wells: Doshier Grayson Drilling (5365 Napa Valley Hwy.) reports to
have drilled 3 wells along Lopes Road. 1) Sweet Ranch Well is 200' deep,
bottomed in grey siltstone and sandstone and makes 50 gpm, 1981. Quarry
Wells: 12 bottomed in basalt at 250', 275gpm, 1980; 13 bottomed in grey clay
and grey rock. 300' deep, 20 gpm, locations unknown.
-------
Table 2 GENERAL CHARACTERISTICS AND THE WELLS IN EACH CLUSTER
Group
1
2
3
4
5
C1:S04
10:1
Variable
10:1
<2:1
Variable ratios
Low chloride
concentration
SpCond
>5000
1000-6000
<5000
>2000
<2000
Wells
MW7, MW14, MW21,-1*728, l*J4$. 1*749 ,
MW56, 2B, C6, MW-13, M^-17, IW-53
MW12, MW16, 1*724* 1*736, 1*737, MW38,
MW39, 1*742
MW10, 1*722, 1*725, 1*727, 1*729, 1*734,
1*741, 1*743, MM46, MH48, 1*751, 1*752
1*71, 1*726, 1*731, MW47, C2
MW4, 1*78, 1*711, MW15, 1*720, MN23,
MH33, 1*735, 1*750, Cl, C4
(Source; Camp Dresser & McKee, 1987)
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-------
TABLE 4 AVERAGE CONCENTRATIONS (mg/L) OF SELECTED INDICATORS IN WELLS
MW-16, MW-35 throunh MW-39
lut_. flW-16 MW-37 MW-35 MW-38
y Background Shallow Bedrock
Cl 110
S04 146
SpCond
(fS/cm)1400
TOC 1.8
TOX 0.1
155
85
1540
2
0.13
138
103
1407
2.9
0.1
38
99
1410
2.4
0.1
MW-39 MW-36
Deen Bedrock
67
270
2070
11
2.3
92
64
1500
4.3
0.1
(Source; Camp Dresser & McKee, 1987)
-------
Table 5
HWGWTF
Groundwater Monitoring Data
August 1986
(Source; Camp Dresser & McKee, 1987)
-------
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-------
Table 6
HWGWTF
Surface Water Quality Data
August 1986
(Source; Camp Dresser & McKee, 1987)
-------
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-------
Table 7
HWGWTF
Soil Quality Data
August 1986
(Source; Camp Dresser & McKee, 1987)
-------
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-------
ATTACHMENTS
-------
FIGURES
-------
^^ i T Y _
6000 FEET
•»
i
ASSESSOR'S PARCEL NUMBERS FOR IT PROPERTY
181-270-01 TO 04; 181-260-01,04 AND
05; 181-240-01,02 AND 03 i 80-030-01
AND 02.
REFERENCE--
FIGURE 1
SITE LOCATION MAP
IT CORPORATION PANOCHE FACILITY
7.5' U.S.O.S. TOPOGRAPHIC QUADRANGLES OF
BENICIA (1959), CORDELIA (1951), FAIRFIELD
SOUTH (1949) AND VINE HILL (1959), CALIFORNIA;
PHOTOREVISED: 1980, SCALE- l>24000
W3 • WELL OR DEVELOPED SPRING
"Do Not Seal* This Drawing
-------
o
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-------
c
TRENCH T-43
GEOLOGIC UNITS
A ORGANIC SOIL - Sandy silt (stn), brown, dry, loose, subhorizontal soil ped
fracturing near base of the unit.
B SOIL - Sandy silt.(sm), medium brown, dry, very loose, friable, many small
tubular voids (highly permeable), few prismatic soil fractures are developed
because of low shrink-swell potential.
C RESIDUAL SOIL - Clayey silt (mh), light gray, some orangish iron staining and
very extensive prismatic soil fracturing. At station 22, this unit grades into
a shale bedrock unit described in Unit E
D SANDSTONE BEDROCK - Moderately weathered, hard, heavily iron oxide stained;
contains siltstone interbeds.
E SHALE BEDROCK - Light gray to tan weathered, thinly bedded clayey siltstone
with heavy orangish brown, iron oxide staining along bedding plane surfaces.
F SANDSTONE BEDROCK - Whitish colored, massive to poorly bedded, medium fine-
grained, weathered sandstone.
GEOLOGIC NOTES
1 Iron-stained joint: N27eW, 63"SW dip.
2 Bedding: N44'E, 9*NW dip.
3 Soil-bedrock contact believed to approximate bedding direction: N29*E, 8*NW
dip.
4 Stone-line. Layer of coarse gravel lain down or concentrated during the soil
forming process.
-------
PROTECTIVE STEEL CASINO
WITH LOCKING CAP
Xj
CEMEN
(FINISH
PORTL
4 INCH
(FLUSH
BENTOt
NO. 1/2
NO. 3 N
(WASHC
4 INCH
INCH SI
(FLUSH
• ' 2 S
•***+
T BLOCK °
ED SURFACE SEAL ) v
4» SCH. 40 PVC BLANK
-THREADED END JOINTS)
JlTP PPI 1 PT1 . •? PT __^__
O MONTEREY SANO-1 FT. -
IONTEREY SAND - 2 FT.
•D)
6 SCH. 40 PVC 0.020
-THREADED END JOINTS)
••
/—THREADED END CAP— ^
— NO. 3 MONTEREY SAND -
— NO. 1/20 MONTEREY
SAND (1 FT.) *
- BENTONITE TO 1 FT. ABOV
TOP OF END PLUG
-N
END PLUG
Y////////.
^
• * •
itWM
1
^ 7~
= :
= H
i i
s s
r =
r s
/
'
"""• «
^N
• . i
^*M
TTT
8 IN.
~ MINIMUM "
rs
J-V*
— SLIP-ON PVC CAP
(VENT THE CAP. NOT
r
2-21/2FT. STICK-UP
. LAND SURF
2
I
I
O
>
J_
2
Z
i
FIGURE t
TYPICAL SHALLO
12 IN.
NOTE:
WITH 12 INCH AUGERS. THE END PLUG AT BOTTOM
AUGER 19 GENERALLY KNOCKED OUT AND LEFT IN
BOTTOM OF HOLE. WHEN USING THIS TECHNIQUE.
ADVANCE HOLE 2 FT. DEEPER AND SEAL OFF THE
PLUG WITH BENTONITE. SEE DIAGRAM •
CONSTRUCTION
IT CORPORATION BENICIA FACILITY
IT CORPORATION
-------
PROTECTIVE STEEL CASING
WITH LOCKING CAP
CEMENT BLOCK
(FINISHED SURFACE SEAL )
SLIP-ON PVC CAP
(VENT THE CAP. NOT THE CASING)
LAND SURFACE
1/9
2-2"* FT. STICK-UP
PORTLAND CEMENT
* BOREHOLE
* OUTER LINER CASINO
4"$ SCH. 40 PVC BLANK
(FLUSH-THREADED END
JOINTS)
BENTONITE PELLETS- 2 FT.
TOP OF UNWEATHERED ZONE
NO. 1/20 MONTEREY SANO-1 FT. - -
NO. 3 MONTEREY SAND -
TO 2 FT. ABOVE SCREEN
(WASHED)
4"0 SCH. 40 PVC 0.020
INCH SLOTTED SCREEN-
(FLUSH-THREADED END JOINTS)
THREADED END CAP
NO. 3 MONTEREY SAND
r.v.
•
i
B IN.
MINIMUM '
BOREHOLE
DIAMETER TO BE DETERMINED
BASED ON AVAILABLE
DRILLING APPARATUS
FIGURE 16
TYPICAL DEEP WELt CONSTRUCTION
IT CORPORATION BENICIA FACILITY
IT CORPORATION
-------
-------
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|