Basewide Hydrogeologic Characterization
Case Study: Naval Air Weapons Stations
China Lake
U.S. Environmental Protection Agency
Office of Solid Waste and Emergency Response
Technology Innovation Office
Washington, D.C. 20460
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Notice
This material has been funded wholly by the United States Environmental Protection Agency
under Contract Number 68-W-02-034. Mention of trade names or commercial products does not
constitute endorsement or recommendation for use.
Comments or questions about this report may be directed to the United States Environmental
Protection Agency, Technology Innovation Office (5102G), 401 M Street, SW, Washington, D.C.
20460; telephone (703)603-9910.
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FOREWORD
Cost-effective cleanup (remediation) of hazardous waste sites cannot occur unless the type,
quantities, and locations of chemical contaminants present at the site are adequately determined
by a process called characterization. Sampling and chemical analysis of environmental media
(water, soil, sediment, etc.) is vital to designing a remediation regimen that will accomplish the
desired goal of reducing risk to human health and the environment. Unfortunately, site
characterization has historically been very costly and time consuming because the technological
options have been few and sometimes inefficient.
Recent technological advances promise better site characterization at less cost and in a shorter
time frame, yet adoption of new technologies into mainstream engineering practice is very slow.
Three widely acknowledged barriers to the adoption and use of innovative site characterization
technologies at hazardous waste sites are:
• Potential users lack personal awareness and/or experience with the technology.
• Potential users lack the established performance criteria needed to assess the applicability of
the technology for a prospective project, and
• Potential users lack the cost and performance information needed to efficiently plan the
project and allocate resources.
The collection and dissemination of cost and performance information is essential to overcoming
these barriers. While technology developers and vendors can be valuable sources of this
information, their claims often carry less weight than evaluations from colleagues who have used
the technology themselves. Case studies are a means by which technology users and impartial
observers may disseminate information about successful applications of innovative technologies
and add to the pool of knowledge that helps move a technology past the "innovative" stage, thus
significantly shortening the time required for widespread benefits to be realized. Case studies can
also be a rich source of feedback to researchers and developers seeking to improve or refine
technology performance under various site conditions.
Individual case studies may focus on a particular technology or on a characterization approach or
process. Case studies focused on process can provide education about how efficient
characterization strategies can be implemented on a site-specific basis, and thus can be valuable
adjuncts in training courses. For many reasons, case studies are valuable tools for the
environmental remediation community.
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Table of Contents
NOTICE ii
FORWARD iii
CASE STUDY ABSTRACT 1
EXECUTIVE SUMMARY 2
SITE INFORMATION 2
BACKGROUND 2
MEDIA AND CONTAMINANTS 4
PRELIMINARY CONCEPTUAL SITE MODEL 4
INTRUSIVE SAMPLING AND ANALYSIS TO REFINE THE CSM 5
RESULTS 7
CONCLUSIONS 8
REFERENCES 9
TABLES
1 SUMMARY BHC OBJECTIVES AND DATA COLLECTION ACTIVITIES
FIGURES
1 LOCATION MAP
2 CHINA LAKE CONCEPTUALIZATION OF GROUNDWATER IN THE INDIAN
WELLS VALLEY
3 SEDIMENT SEQUENCE - REGRESSIVE LACUSTRINE SEDIMENT SEQUENCE
4 HISTORIC SHORELINES
5 CONCEPTURALIZATION OF AN ALLUVIAL FAN-LACUSTRINE
SEDIMENTARY ENVIRONMENT
6 CONCEPTUALIZATION OF OWENS RIVER DETLA SEDIMENTARY
ENVIRONMENTS
7 CONCEPTUALIZATION OF DEPOSITIONAL ENVIRONDMENTS IN THE INDIAN
WELLS VALLEY
8 CONCEPTURAL BLOCK DIAGRAM OF INDIAN WELLS VALLEY
9 WATER FLOW CONCEPTUAL MODEL
10 BERENBROCK FIGURE
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CASE STUDY ABSTRACT
NAWS China Lake
Inyo and Kern County, California
Site Name and Location:
Naval Air Weapons Station China
Lake, Inyo County, California
Sampling & Analytical Technologies:
1. Isotope geochemistry;
2. Radon gamma spectroscopy (Teledyne Brown Engineering Environmental
Services)
3. Carbon, oxygen and deuterium mass spectrometry VG602 (Laboratory of
Isotope Geochemistry at The University of Arizona)
4. Tritium, quantulus 1220 LSC #2 (Laboratory of Isotope Geochemistry at
The University of Arizona)
5. Chlorine, modified VG 602C mass spectrometer # 2 (Laboratory of Isotope
Geochemistry at The University of Arizona)
6. Chlorine, low level beta counting (Teledyne Brown Engineering
Environmental Services)
7. Boron, VG336 thermal ionization mass spectrometer, (Laboratory of
Isotope Geochemistry at The University of Arizona)
8. Strontium, thermal ionization mass spectrometer (Geochron Laboratories,
Inc)
9. CFC, purge and trap capillary column gas chromatography (University of
Miami)
10.X-ray florescence and X-ray diffraction analysis (XRAL Laboratories)
11. Thin section petrographic analysis (DCM Science laboratory, Inc)
12.Physical property testing (A and P Engineering)
Period of Operation:
1943 to present. Supports
research and development of navel
air craft and ordnance.
Current Site Activities:
RI/FS and IRP work on 53 sites
Point of Contact:
Robert Howe
Tetra Tech EMI.
4940 Pearl East Circle
Suite 100
Boulder, CO 80301
(303) 441-7900
Media and Contaminants:
Groundwater and soils at NAWS
China Lake are contaminated with
chlorinated and aromatic solvents,
metals, and petroleum compounds.
Technology Demonstrator:
Number of Samples Analyzed during Investigation:
A soil sampling program from 12 bore holes produced the following: 40 samples collected for XRF analysis, 8 for
XRD analysis. A groundwater and surface water sampling program produced: 59 oxygen-18, deuterium, and
carbon-14 analysis, 36 tritium and sulfur 34 analysis, 38 strontium 87/86 analysis, 46 radon 222 analysis, 35 CFC
analysis, and 47 boron 11 analysis.
Cost Savings:
The cost savings using this approach are estimated at 50% of traditional methods
Results:
The China Lake CSM was used as a dynamic decision making tool during the basewide hydrogeologic
characterization of IWV. The construction of the CSM resulted in a better understanding of the system, which
sites pose the greatest risk, and which sites should be considered for no further action status.
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CHINA LAKE
EXECUTIVE SUMMARY
A geologic and hydrogeologic conceptual site model (CSM) was constructed for the Navel Air
Weapons Station (NAWS) China Lake in order to fulfill objectives set forth by the NAWS China
Lake record of decision (ROD). The objectives of developing a CSM for NAWS China Lake
were to: 1) gain a fundamental understanding of the geology and hydrogeology in and around the
facility; 2) locate groundwater recharge sources, groundwater flow directions, and travel times in
water bearing zones; 3) understand and map changes in groundwater quality (geochemistry), and
4) to identify areas were activities from the NAWS China Lake facility could be impacted water
quality in the Indian Wells Valley (IWV).
The overall objective of the program was to design a monitoring well network of wells to support
closure of the over 56 sites identified at the facility and protect groundwater quality and resources
in the area. The data collection design included the collection of data to support contaminant fate
and transport evaluations. Groundwater quality and changes in pieziometric surfaces over time
were evaluated to evaluate long-term trends in water quality with groundwater use. Any loss of
potable groundwater in IWV due to degrading water quality is given considerable attention
because IWV water supply is limited and demand for water is growing.
SITE INFORMATION
Naval Air Weapons Station (NAWS) China Lake
Kern and Inyo Counties, California
BACKGROUND
Most of the NAWS China Lake facility is located in IWV in the northern Mojave Desert of
California. IWV is located in the southwest corner of the Great Basin section of the basin and
range physiographic province (Figure 1). IWV is bordered on the west by the Sierra Nevada, on
the east by the Argus Range, on the north the Coso Range and on the south by the El Paso
Mountains, Rademacher Hills, and Spangler Hills (TtEMI 2001a).
Elevations in IWV vary from approximately 3,000 feet above mean sea level (msl) at the margins
of the valley to approximately 2,150 feet msl at the China Lake playa in the southeastern corner
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of the China Lake Complex. Elevations of the Sierra Nevada to the west exceed 9,000 feet msl,
the Coso range to the north average 6,500 feet msl, and the highest point in the Argus Range is
Maturango Peak at 8,839 feet msl (TtEMI 2001a).
IWV has an average annua! precipitation of 3 to 6 inches. Most precipitation occurs between
October and March, with December generally being the wettest month (TtEMI 2001a).
Prior to the development of this CSM, a conceptual model of the groundwater flow in
IWV (Figure 2) was proposed by Dutcher and Moyle 1973, Warner 1975, and
Berenbrock and Martin 1991. This earlier conceptual model was used as the starting
point for the development of the current CSM. However, this model suggested the
presence of a single unconfined system where water entered the system from the west and
flowed towards the center of the playa where it would discharge to the China Lake Playa.
With reversal of the gradient away from the playa, located near the center of the facility,
through pumping by surrounding residences and the local municipality, the historical
CSM suggested that the observed increases in total dissolved solids likely originated from
the base.
Site Logistics/Contacts
This section contains the basic contact information for the project, such as.
Lead Agency : U.S. Navy
Oversight Agency:
Remedial Project Manager: TTEMI Project Manager
Mr. Mike Cornell Mr. Richard Knapp
Department of the Navy Tetra Tech EM Inc.
Naval Facilities Engineering Command 6121 Indian School Road, N.E.
Southwest Division Suite 205
Code 5DEN.MC
1220 Pacific Hwy.
San Diego, CA 92132-5190
(619) 532-4208
Albuquerque, NM 87110
(505) 881-3283
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Quality Assurance Officer
Nars Ancog
Quality Assurance Officer
Department of the Navy
Naval Facilities Engineering Command
Southwest Division
Code 4EN3.NA
1220 Pacific Hwy.
San Diego, CA 92132-5190
(619) 532-2540
MEDIA AND CONTAMINANTS
The purpose of this section is to describe the types of contaminants present at the site,
and the characteristics of the matrices in which they are found. Include information on
the listed topics as needed to aid case study coherence:
Matrix Identification
Type of Matrix Sampled and Analyzed: Groundwater, surface water, and subsurface
soil.
PRELIMINARY CONCEPTUAL SITE MODEL
In the early stages of the construction of a revised CSM for NAWS China Lake, an extensive
literature review was conducted. Geologic, hydrogeologic, structural, and geochemical data was
uncovered for nearly 2000 existing wells in the area during the literature review. Data was used
from nearly 300 of these wells to create maps, cross-sections, and geochemical plots (Stiff and
Piper diagrams). Borehole logs when available were used to create geologic cross-sections,
structure contour, and isopach maps. Stiff and Piper diagrams were used to identify water types
based on the major ion chemistry. Geologic cross-sections helped identify the hydrogeologic
units present in IWV. A structure contour map was made on the top elevation of a low
permeability lacustrine clay dominated intermediate hydrolgeologic unit and an isopach map was
made of its thickness. The examination of these diagrams and maps helped the CSM team
identify the presence of three discrete geologic and hydrogeologic water bearing units in IWV
previously thought to be a single inter-connected system. The project team designated these
zones as the Shallow Hydrogeologic Zone (SHZ), the Intermediate Hydrogeologic Zone (IHZ),
and the Deep Hydrogeologic Zone (DHZ).
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Further study of the literature from surrounding areas also revealed that IWV is located in the
southwestern part of the Basin and Rasin Physiographic Province, IWV is a half-graben structural
depression bounded by pre-Tertiary igneous and metamorphic rocks that also underlie the basin.
Faulting of two major styles and ages are present and continue to keep the area tectonically
active. The structural depression is filled with consolidated continental deposits of Tertiary age
and over 1,500 feet of Pleistocene unconcolidated sediments that mostly represent alluvial fan,
alluvial, and lacustrine deposits.
The depositional environment changed dramatically during wetter periods of the Pleistocene.
During these wetter periods, much of the basin fill consisted of lacustrine sediments that were
related to glacial epochs, subsequent basin flooding, and ancestral Owens Lake overflow. While
the mid valley sediments are typically fine-grained and lacustrine, basin margin sediments are
more coarsely grained and more poorly sorted.
Based on historical and previous information available from the site geologic it was determined
that the IHZ was a potentially bounding clay sequence that could potentially restricted aquifer
interactions beneath the facility where combined lacustrine clay sequences were known to
exceeded 500 feet in thickness. These lake sediments, as shown in Figure 3, where identified by
the project team as representing an almost ideal regressive sequence that had come and gone
throughout the valley relatively rapidly. It became apparent to the project team, based on this
preliminary CSM that understanding the nature and extent of the IHZ would be crucial to
determining when and where the contaminated SHZ below the facility might have the potential to
impact water in the DHZ, which is the principal source of drinking water in the region.
Primary Contaminant Groups
The primary contaminant groups at NAWS China Lake are volatile organic compounds
(VOCs), polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs),
and metals.
INTRUSIVE SAMPLING AND ANALYSIS TO REFINE THE CSM
A total of 12 borings were initially continuously cored to depths that ranged from 473 to 798 feet
bgs. The detailed boring logs filled data gaps and allowed the CSM team to refine and add
certainty to the geologic and hydrogeologic understanding of the site. This new geologic data
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was combined with what was already known to create a number of figures used to communicate
the revised CSM to stakeholders. A map showing the estimated extent of the former Pleistocene
lakes that where responsible for the development of the IHZ (Figure 4), several cartoons showing
the relationship between the alluvial, lake, and delta sediments in IWV (Figures 5, -6, and 7)
where created to communicate the logic used by the project team to the residence of the area. A
geologic block diagram of IWV, Figure 8 (TtEMI 2001a) was also created detailing the primary
structural features in the region and their relationship to the geology and hydrogeologic zones .
The block diagram (Figure 8) is also a schematic representation of the geologic and
hydrogeologic features of IWV relevant to the CSM.
Geologic soil samples were collected during the drilling of the exploratory borings. The soil
samples were collected at regular and unspecified intervals when lithologic variations were
observed. In addition to standard geologic inspections soil samples were analyzed using X-ray
diffraction (XRD), X-ray florescence (XRF), thin section petrography, carbon-14 age dating, and
physical property testing. The XRF, XRD, and thin section petrography were used to identify the
mineralogy and chemical species present in the samples. This data was then used as constraints
in the geochemical modeling to determine groundwater residence times. The carbon-14 soil dates
were used to examine soil age versus depth profiles. Physical property testing for specific
gravity, percent moisture, dry density, bulk density and porosity was also performed to estimate
which water bearing units where likely to transmit or block flow.
Groundwater and surface waters were sampled for environmental isotopes. The isotopes sampled
in this study included: oxygen, deuterium, carbon, tritium, strontium, sulfur, chlorine, radon, and
the intrinsic tracer chlorofluorocarbon (CFC). These isotopes and intrinsic tracers were used to
identify groundwater flow paths, hydraulic connection between groundwater zones, recharge
sources, and groundwater age.
Groundwater elevations were measured in numerous wells across the site to develop
potentiometric surface maps. Water levels were measured on a quarterly basis to determine if the
groundwater surface elevation had any seasonal fluctuations. Potentiometric surface maps were
created for the shallow and deep hydrogeologic zones. These potentiometric surface maps were
used to indicate the directions of groundwater flow and to calculate flow gradients.
Potentiometric surface maps indicated areas within the study area where additional water level
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measurement would be needed to fill gaps in the potentiometric surface map coverage. From
these maps flow directions could be mapped and compared with the extent of the clay packages
South of the facility to determine where additional investigative work was required.
The new borehole data, isotopic signatures of the water samples, and the age dates of the water
and soil samples were used to refine the preliminary CSM. Geochemical modeling was performed
with NETPATH and WATEQ4F. WATEQ4F was used to calculate the saturation indexes,
chemical activities, and mineralogical phases present in the system. NETPATH was used to
calculate the travel times of four different plowpaths in IWV. Changes to the original CSM that
resulted from the sampling and analysis program included:
• The likely source of TDS to the DHZ in the area near the Town of Ridgecrest is from
deep water within the DHZ and not the contaminated SHZ beneath the facility
• The IHZ appears to be a barrier to communication between the SHZ and DHZ
• Most contaminated water beneath the facility is following towards the center of the playa
and away from areas where the IHZ pinches out to the south near Ridgecrest
• Limited communication between aquifers in the area between Ridgecrest and NAWS
China Lake is likely influenced by surface water trenches or discharges to the surface
(unlined drainage ditches and or impoundments)
• Groundwater age dates indicate that deep groundwater (DHZ) beneath the IHZ does not
likely discharge to the surface in the playa as predicted by the previous CSM for IWV.
• Water quality is highly variable across the basin, but is of the highest quality and quantity
along the western edge of the basin where fault system may not act to block the flow of
modern recharge.
Figure 9 is the revised schematic rendition of the IWV CSM (TtEMI 2001b). These findings
were contrary to those that had been made previously and have significantly impacted
prioritization of activities to be conducted at the nearly 100 sites located on the facility.
RESULTS
The CSM constructed during this study has met its objectives. The first objective was to gain a
fundamental understanding of the hydrogeology across the NAWS China Lake complex. An
extensive review of the existing data and literature was used to form a preliminary understanding
of the site hydrogeology. Additionally, the mapping of the SHZ's and DHZ's potentiometric
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surfaces and the geologic descriptions from exploratory borelogs were fundamental in
accomplishing this first objective.
An understanding of groundwater recharge zones, flow directions and travel times was also
gained through the potentiometric surface mapping. Additionally oxygen, deuterium, and
strontium isotopic analysis furthered the understanding of the groundwater recharge zones and
flow directions. Tritium, CFC and carbon-14 age dating of the groundwater were used to
estimate groundwater travel times. Groundwater travel times from recharge zones in the Sierra
Nevada to the well fields in IWV were estimated and used understand potential flow paths and
location of better quality water in the region.
Stiff and Piper plots of the major ion geochemistry of the ground and surface waters from IWV
were created to evaluate groundwater quality and to distinguish water types based on
geochemical characteristics. The influence of groundwater pumping on groundwater quality was
investigated by plotting groundwater elevations with oxygen and deuterium isotopic ratio values
versus time. This illustrated that as groundwater elevations in the DHZ declined the observed
deuterium values became more negative; indicating that groundwater pumping was pulling water
from greater depths rather than from the SHZ as shown in Figure 10 (TtEMI 2001b). This
finding was significant because most of the groundwater contamination is located in portions of
the SHZ.
Isotopic signatures of the shallow, intermediate, and deep hydrogeologic zones were identified by
creating scatter plots of the isotopic values versus the total concentration of the parameter or
versus the sample elevation. With the signatures of the different hydrologic zones identified, the
amount of mixing between zones was evaluated. This allowed the CSM team to evaluate the
impacts that the NAWS China Lake facility has had on the overall groundwater quality and
resources in the IWV region. In addition, the revised CSM will provide a basis for any further
fate and transport modeling or additional isotopic work to continue to refine the Navy's and the
public stakeholder's knowledge of the natural resource and environmental issues in the area.
CONCLUSIONS
This CSM has guided the project team's decisions and actions. Key decisions made during the
CSM process include the type and location of additional fieldwork. For example, the CSM was
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used to determine the location of additional borings, wells, and the screen interval of the wells.
The CSM was used as a dynamic tool to plan additional field activities. The next phase of this
project is to design a monitoring network to confirm and validate the present CSM. The data
returned from the planned monitoring network will be used to further revise the CSM and focus
monitoring and measurement activities to be conducted at the site.
A refined CSM will be able to identify hydraulic connection between hydrogeologic zones
and groundwater flow lines on a smaller scale that can be applied to individual sites included in
the Installation Restoration Program (IRP) within the NAWS China Lake complex. Site
prioritization and closure status of IRP sites will be determined by using the CSM as an
interactive, dynamic, decision-making tool. This will identify the IRP sites that need further
review. Sites requiring further action will continue in the process and will be evaluated based on
site closure criteria. Additionally, the CSM process will provide a clear vision on how to most
effectively allocate funds for the eventual closure of all IRP sites
REFERENCES
Berenbrock, C. and P. Martin. 1991. The ground-water flow system in Indian Wells
Valley, Kern, Inyo, and San Bernadino, Counties, California. U.S. Geological
Survey Open-File Report 89-4191. 56 Pages.
Dutcher, C.R., and Moyle, W.R., 1981, Geologic and hydrologic features of Indian Wells
Valley, California: U.S. Geologic Survey Water-Supply Paper2007, 50 p.
Hantush, M.S. 1964. Hydraulics of Wells. In: Advances in Hydroscience. V.T Chow
(editor) Volume I. Pages 281-432. Academic Press. New York.
Hurr, R.T. 1966. A New Approach for estimating Transmissibility from Specific
Capacity. Water Resources. Volume 2. Pages 657-664
PRC Environmental Management, Inc. (PRC). 1993. RI/FS Waste Management Plan,
NAWS China Lake, China Lake, California. Draft Final. October.
Tetra Tech EM Inc. (TtEMI). 2001a. Preliminary Basewide Hydrogeologic
Characterization Report. Navel Air Weapons Station China Lake, California.
June 2001.
Tetra Tech EM Inc. (TtEMI). 2001b. Internal Draft Preliminary Basewide Hydrogeologic
Characterization Report. Navel Air Weapons Station China Lake, California.
Addendum A. May 2001.
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Tetra Tech EM Inc. (TtEMI). 1998 c Remedial Investigation/Feasibility Study Draft
Final Quality Assurance Project Plan. NAWS China Lake. April 10.
Theis, C.V. 1935. The relation Between the Lowering of the Piezometric Surface and the
Rate and Duration of Discharge of a Well Using Groundwater Storage.
Transactions of the American geophysical Union. Volume 16. Pages 519-524.
U.S. EPA. EPA QA/G-5: EPA Guidance on Quality Assurance Project Plans. Office of
Research and Development, Quality Assurance Division. Washington, DC.
EPA/600/R-98/018. February 1998.
Warner, J.W., 1975, Ground-water quality in Indian Wells Valley, California: U.S.
Geological Survey Water Resources Investigations Report 8-75, 59 p.
Worthington, P.F. 1981. Estimation of the Transmissivity of thin Leaky-Confined
Aquifers from Single-Well Pumping Tests. Journal of Hydrology. Volume 49.
Pages 19-30.
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TABLE 1
SUMMARY BHC OBJECTIVES AND DATA COLLECTION ACTIVITIES
NAWS CHINA LAKE, CALIFORNIA
Stii«l\ Area
()hjedi\es
T\|K' nl° Data Aci|iiiml
Data ( nlk-iiiim and l;m|iK'iic\ of
Acquisition
Data Anal\sis Siiiiiniar\
Indian Wells
Valley
Determine number,
availability, and
condition of existing
groundwater monitoring
wells
Basewide inventory of
existing monitoring wells,
including data regarding well
locations, construction, and
well screen positions
Visual survey, existing records, and video
survey completed at selected wells to
determine usability
Determine usability and purpose of
each well according to study
definition of a usable well
Establish lithologic
definition and control
Borehole logs, downhole
geophysical logs, and
continuous core data
Leliter Area - 1 borehole drilled to the deep
aquifer system, approximately 500 feet in
depth
Continuously core and log
boreholes according to Unified Soil
Classification System
Main Base Area - 6 boreholes drilled to the
deep aquifer approximately 750 feet in depth
Conduct geophysical logging to
include spontaneous potential (SP),
resistivity, guard, gamma ray, and
caliper logs
Brown Road/Northwest Base Area - 1
borehole drilled to the deep aquifer,
approximately 650 feet in depth
Log, label, and archive continuous
core samples
Little Lake Fault Zone/Ridgecrest - 4
boreholes drilled to the deep aquifer,
approximately 750 feet in depth
Collect data in accordance with the
RI/FS QAPP (TtEMI 1998c) and
the QAPP
Existing well information as available
Construct stratigraphic sections to
establish lithologic definition and
control
Determine groundwater
mound sources at the
Main Gate area
Borehole logs, downhole
geophysical logs, continuous
core data, and long-term water
level monitoring data
Main Base Area - 6 boreholes; approximately
26 wells will be installed in the shallow,
intermediate, and deep aquifer systems; water
levels will be monitored for 2 years to cover 2
annual cycles of seasonal water use
Use stratigraphic information and
water level data trends to locate a
potential source for the existing
groundwater mound
Identify water bearing
zones (WBZ) and
hydrogeologic unit
correlation
Borehole logs, downhole
geophysical logs, and
continuous core data
All 12 boreholes in all 4 areas of Indian Wells
Valley; hydrostratigraphic sections will
illustrate hydrgeologic units (WBZs)
correlated laterally using both existing and
new data
Use stratigraphic and downhole
geophysical information to identify
and correlate WBZs
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TABLE 1 (Continued)
SUMMARY BHC OBJECTIVES AND DATA COLLECTION ACTIVITIES
NAWS CHINA LAKE, CALIFORNIA
Stii«l\ Area
()hjedi\es
l \|K' nl° Data Aci|iiiml
Data ( nlk-iiiim and l;m|iK'iic\ nf
Acquisition
Data Anal\sis Siiiiiniar\
Indian Wells
Valley
(Continued)
Define groundwater flow
directions
Water level measurements
Selected wells in Indian Wells Valley
identified for long-term water level
monitoring
Use long-term continuous water
level monitoring measurements to
identify groundwater flow
directions; establish seasonal
variation, effects of pumping and
trends with long-term data
Define groundwater
quality
Groundwater monitoring well
installation logs, results for
groundwater samples collected
during drilling, and quarterly
groundwater monitoring data
Installation of approximately 47 wells in
Indian Wells Valley; the quarterly
groundwater sampling program will include
approximately 60 selected wells
Use quarterly sampling results to
establish statistically-based
population distribution for specified
parameters
Define aquifer response
to annual cycles
Long-term water level
monitoring data
Quarterly water level monitoring in selected
wells, including existing IWVWD wells
Examine quarterly hydrographs foe
all wells monitored to identify and
correlate trends to annual pumping
rates
Define groundwater flow
direction
Long-term water level
monitoring data
Quarterly monitoring in selected wells
Examine quarterly flow directions
for selected wells and well clusters
to establish consistent flow trends
Evaluate radius of
influence of Navy supply
wells in Inyokern
Inventory of pumping records
from Navy, Inyokern
Community Services District,
and North American Chemical
Company
Existing pumping records, water levels,
aquifer hydraulic parameters
Determine radius of influence,
long-term effects, and provide
wellhead protection program data
Determine groundwater
age and travel times
Carbon -14 and Tritium
activities, and CFC
concentrations from
groundwater samples
Water samples will be collected one time from
selected wells and springs
Age date groundwater, determine
groundwater travel times and
estimate zones of recharge
Determine hydraulic
communication between
hydrogeologic zones
1bO, D, ,4S. B/Sr/ Sr, Rn, "CI.
36C1, and nB isotopic data
from surface and groundwater
Water samples will be collected one time from
selected wells and springs
Isotopic signatures from each
hydrgeologic zone will be analyzed
to determine if communication and
mixing is occurring between zones
Characterize
investigation-derived
waste (IDW)
Laboratory analytical data for
soil and groundwater samples
collected at borehole and well
locations
Drilling and purge water will be contained and
analyzed; unconfined soil and groundwater
will be discharged to the ground surface
Characterize and dispose of IDW
according to RI/FS Waste
Management Plan (PRC 1993)
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HWY
INDEPENDENCE
Naval Air Weapons Station
China Lake Complex
O LAS VEGAS
DARWIN
OLANCHA fi
LITTLE LAKE C
BROWN
TRONA
Naval Air Weapons Station
Randsburg Wash/Mojave B
Complex
INYOKERN
RIDGECREST
BAKERSFIELD
HWY
HWY
395
BARSTOW
HWY
LOS
ANGELES
SAN BERNARDINO
PACIFIC
OCEAN
SAN DIEGO
CASE STUDY
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AREA OF UNCONFINED GROUNDWATER
Area where groundwater flows toward deep
aquifers from shallow aquifers. Shallow wells
have higher head than deep wells.
RECHARGE
AREA OF SEMICONFINED GROUNDWATER
(BACKGROUND GROUNDWATER CHEMISTRY STUDY AREA)
Area where groundwater flows approximately
parallel to upper and lower aquifer boundaries.
Shallow and deep wells have approximately
the same head.
Area where groundwater flows upward toward
playa surface to be discharged to atmosphere.
Deep wells have higher head than shallow wells.
SHALLOW WATER LEVELS
DEEP WATER LEVELS
Shallow Aquifer
Deep Aquifer
RELATIVELY IMPERMEABLE SEDIMENTARY ROCKS
AREA OF
DISCHARGE
(Evapotranspiration)
SHALLOW WATER LEVELS
DEEP WATER LEVELS
BASEMENT ROCK
IMPERMEABLE CLAY
-GROUNDWATER FLOW
SOURCE: Redrawn and modified from Dntcher and Moyle (1973) and Berenbrock and Martin (1991)
CASE STUDY
CHINA LAKE - CONCEPTUALIZATION OF GROUNDWATER FLOW IN THE INDIAN WELLS VALLEY
FIGURE 2
-------
Examples of Lacustrine
Sequences in the
Geologic Record
Ideal Lake LISCS China Lake
Sequence (BHC Report) Sequence
(Pleistocene)
o
a
u
V
c
vW
\A/V
sAA/i
— istr/op
— SC/SP
SM
— WL/SM
a
/w
Lake Uinta
(Eocene)
v
c
£ t
""e
Off lJ
N/Vvf
5
~c
3
K/vv
LockaLong Frn
(Late Triassic)
NAA/1
H
(A
-*
0
1
&
c
3
V
03
qn
c
_Q
a
k'vVJ
w
Leqsin-3
USCS C ctleii-
I I Ptrmivtm unltl CW. CP. 5W iP
Uthomtratigraphie Unit*
I I Cie-'H Mild 4 OMrwtt
~ Tkm !0 mflCjJu'r' #ijn£
I 5cm dy *n & zioy
CD »'"* A <*jyi
I - i LirT»*i3ifwi'll
Sagirce Modi lied from ons Hiqri {1
-------
i
?M2PZm
%
14,060 yb
™**r\
TW> J* >"¦
° '•"* rrfefv-SB06
yfep
N
I W •" " ,u^'uy^/7—Ll#iH ^ i1*w
S J|
- ^,t— jlii ™,.a034F' V
Site 1a ft
10X170 yb
'"1\ \
TT37-S®
h 6,840 ybp
I _ ^^7 TTIWV-SB05
I' IMTERMBDWTtWELL .III 2®>060 yb
^S» I' ^|Eldarea ll
— imwv-SB02"
' / /. >w-''
OAiwy.
29,420 ybp
i,
CITY OF INYOKERN
TTIwv-SB
220 ybp
*
TTIWV-SB1J
^IcjTY of RIDGte
:(*, RIDQEC REST WELL
^pj:. FIELD AREA
LEGEND
/\# NAWS China Lake Boundary
/\/ Road
CHINA LAKE FIGURE
HISTORIC SHORELINES
NAWS CHINA LAKE, CALIFORNIA
/\/ Ground Surface Elevation
v (100 ft interval)
15000 Feet
/ w' Intermittent or Dry Drainage
IRP Site
SCALE: 1 inch = 15,000 feet
Historic Shoreline Highstands of China Lake
During Pleistocene Glaciations
Tioga, 10,000-25,000 ybp
(corresponds to the 2200' contour)
Kj Tahoe, 70,000-150,000 ybp
(corresponds to the 2300' contour)
a M Conjectural Older Pleistocene,
/V 150,000-1,000,000 ybp
(corresponds to the 2400' contour)
-------
Fan Head
Foot
Crystalline
Bedrock
Conceptualization of an Alluvial
Fan-Lacustrine Sedimentary Environment
CASE STUDY
CHINA LAKE - CONCEPTUAL ENVIRONMENTAL MODEL
FIGURE 5
-------
Sierra Nevada Front
Sierra Nevada Fans
t
Conceptualization of Owens River
Delta Sedimentary Environments
CASE STUDY
CHINA LAKE - CONCEPTUAL ENVIRONMENTAL MODEL
FIGURE 6
-------
- ' > , A, s * - ' * / J A
.. . i , , -X / - ¦ t ' \
* - - * *• >» * ' ^ "
jO ' »• '' ' ' *
r.*'- *'
v- • v-
t*
Q UU*?|J1NA*T /*H tlDWR. pm,,,
}»v] (juitwmajcit r« ctPDira
jo^j guMOtftWT ffljtss rwi strain
[aa?; QlKflMMtf «JJWWW OiPtrHlS
fgT] $u»itnrW9* .«£ij5T»wr oirosift
[aT| «M!SWi**f 3JW* MWMin
|"j71 ««*SSie CBAMOdlOISTI
SOUHf'iE t iguia h«r..«l oti yaologlci dsscflplw m ir, >(ml ami OIbbu t ISKii
CONCEPTUALIZATION OF
DEPOSITIONAI ENVIRONMENTS
IN THE INDIAN WELLS VALLEY
NAW3 CHINA lAKE, CALIFORNIA
CASE STUDY
CHINA LAKE - CONCEPTUAL MODEL OF DEPOSITIONAL ENVIRONMENTS
FIGURE 7
-------
CHMA LAKE SHOREUNES
v
LEGEND
A*UMAL/Wa.TA POJN P«3C£
p«ceaTA/i>aEnaME wcies (lew »cnuD>atjrr}
CMANM&/FMI r*CO {HCM HHMBWJtV)
ttlUVUt/FUM«t P*OE5 (INCLUDES POt-fMKTOCfUC SEDMCWni)
I _ (wsewiw awir* #wn nv>cn*EB
expLatttTW iowiss
APWtOMUAIf CONTACT
FAUt-t (AMOWS WDtCATT DRECTKN Of
MO ~TON, BAU. ON EKSMWTHBOIBJ BLOCK)
(AFTER ROOjtMWE *N0 2EUMER l«B7.
MO QSTOtCK 19B7)
CH0SS-5ECH0M
APPW2MWATC OCK*CAI*V OF RECESS PEAK,
AMQ TENA*A LAKE DCP09TS,
It,000 - 27.008 >bj> (ALSO MXUOES flCCENt L*KE
DCTCSTS, 3,000 - a,COO fie)
APPflOMiAll SEWRA teVAOA FSONT
sac ponc BOyWAn-r TOHsxiOfflur
f*D5T0<3>£
BLOCKS NOt TO S CMS
w - ivta BEKWT PHESEKT
BLOWS OEPET COWKiUDUS AKEAS
AND *K HOT SEPARATED ET> Am CWUNCC
CASE STUDY
CHINA LAKE - CONCEPTUAL BLOCK DIAGRAM OF INDIAN WELLS VALLEY
FIGURE S
-------
SIERRA NEVADA
MOUNTAINS
/ \
Southern cross section through Indian Wells Valley (absence of clay)
CASE STUDY
MOUNTAIN FRONT
RECHARGE
YOUNG WATER
EAST
ARGUS
RANGE
CHINA LAKE PLAYA
1)11/
no; i '"i
section through Indian Wells Valley (thick clay)
SIERRA NEVADA
MOUNTAINS
WEST
MOUNTAIN FRONT
RECHARGE
YOUNG WATER
ARGUS
RANGE
OLDER
YOUNGER GROUND WATER
GROUNDWATER
Middle
section through Indian Wells Valley (thm clay)
SIERRA NEVADA
OUNTAINS
MOUNTAIN FRONT
RECHARGE
YOUNG WATER
WEST
DRAWDOWN FROM
PRODUCTION
WELLS
LOCATION MAP
MAN WELLS VALLEY
RIDGECRESf / "" .r-
kfflNALAK^/^ ;
CHINA LAKE
LEGEND FOR FF-FF'
NOT TO SCALE
~
~
m
ALLUVIAL/DELTA PLAIN FACIES
SHALLOW HYDROGEOLOGIC ZONE (SHZ)
PRODELTA/LACUSTRINE FACIES (LOW PERMEABILITY)
CHANNEL/FAN FACIES (HIGH PERMEABILITY)
INTERMEDIATE HYDROGEOLOGIC ZONE (IHZ)
ALLUVIAL/FLUVIAL FACIES (HIGH PERMEABILITY)
DEEP HYDROGEOLOGIC ZONE (DHZ)
LEGEND FOR GG-GG' AND HH-HH'
~ YOUNG GROUNDWATER
_
—GROUNDWATER SURFACE
~
UNSATURATED ZONE
7\| BASEMENT COMPLEX WITH FRACTURES
(ALL DIAGRAMS)
CROSS-SECTION LINE
CHINA LAKE - WATER FLOW CONCEPTUAL MODEL
FIGURE 9
-------
-94
-96
-100
-102
-104
-106
-108
~ TtEMI (2000)
¦ Berenbrock (1986)
26S40E22P03
26S40E23D01
27S40E02J01 26S40E23D02
PT NAME
26S40E22P02
26S40E22P04
CHINA LAKE FIGURE 11
5D VALUES FROM BERENBROCK (1986)
VERSUS SD VALUES FROM TTEMI (2000)
NAWS CHINA LAKE, CALIFORNIA
CASE STUDY
CHINA LAKE - BERENBROCK FIGURE
FIGURE 10
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