San Antonio

New Braunfels

Boerne

Trinity aquifer

Edwards-Trinity aquifer

Edwards aquifer 

BEXAR COUNTY

COMAL COUNTY

KENDALL COUNTY

98 ̊06'30"

30 ̊07'30"

29 ̊52'00"

29 ̊36'30"

29 ̊21'00"

98 ̊22'00"

98 ̊53'00" 98 ̊37'30"

Study

area

Balcones

fault

zone

Camp Stanley

Storage Activity 

Modified from Pantea and others, 2014 

OKLAHOMA

TEXAS

Edwards-Trinity

aquifer

Edwards aquifer

Trinity

aquifer

Arbuckle-Simpson

aquifer

KENDALL

COUNTY

BEXAR

COUNTY

COMAL

COUNTY

GULF OF MEXICO

Map

area

EXPLANATION

Major aquifers

Edwards-Trinity

Edwards

Trinity

Study area 

Camp Stanley Storage Activity 

Arbuckle-Simpson

Municipal areas

0 5 10 MILES

0 5 10 KILOMETERS

Characterizing the Subsurface Geology In and Around 

the U.S. Army Camp Stanley Storage Activity, 

South-Central Texas

Figure 1. Location of the Camp Stanley Storage Activity 

study area, Bexar County, Texas (modified from Pantea and 

others, 2014).

The geologic framework and hydrologic 

characteristics of aquifers are important components 

for understanding the Nation’s subsurface geology 

and predicting its hydraulic budgets. Integrating 

surface lithostratigraphic and hydrostratigraphic 

mapping can help characterize the spatial distribution 

and hydraulic connectivity of an aquifer’s permeable 

zones. Three-dimensional (3D) geologic modeling of 

an aquifer system can quantitatively characterize the 

connectedness of rock units across fault and 

fracture zones and enable geoscientists to visualize 

the spatial relations between the saturated and 

unsaturated stratigraphic units. Three-dimensional 

geologic framework model data can also be integrated 

into groundwater flow models, such as those 

constructed using MODFLOW (Christenson and 

others, 2011; Blome and Smith, 2012). 

Several U.S. Geological Survey (USGS) projects, 

supported by the National Cooperative Geologic 

Mapping Program (NCGMP), have used multidisciplinary approaches over a 14-year period to reveal 

the surface and subsurface geologic frameworks of 

the Edwards and Trinity aquifers of central Texas and 

the Arbuckle-Simpson aquifer of south-central 

Oklahoma (fig. 1). Some of the project achievements 

include advancements in hydrostratigraphic mapping, 

3D subsurface framework modeling, and airborne 

geophysical surveys as well as new methodologies

that link geologic and groundwater flow models 

(Blome and others, 2007; Blome and Smith, 2012). 

One area where some of these milestones were 

achieved was in and around the U.S. Army Camp 

Stanley Storage Activity (CSSA), located in northwestern Bexar County, Texas, about 19 miles northwest of downtown San Antonio (fig. 1).

U.S. Department of the Interior

U.S. Geological Survey

Fact Sheet 2017–3090

February 2018

The authors show how the U.S. Geological 

Survey acquired new downhole 

geophysical and petrophysical data and 

constructed a 3D EarthVisionTM model 

to better understand the geological 

controls on groundwater flow and (or) 

direction in and around the U.S. Army 

Camp Stanley Storage Activity (CSSA).
Edwards aquifer (Edwards in the 

model)

Mapped 

hydrostratigraphic

units, colors keyed

 to fig. 6

Model 

hydrostratigraphic 

units, colors keyed 

to figs. 4, 7, 8

System

Edwards

Kainer Fm. Glen Rose Limestone

Lower Cretaceous

Pearsall Formation

Hammett

Shale

Cow Creek

Limestone

Bexar

Shale

Sligo Hosston

Group

Formation

Member Dolomitic Basal nodular

Edwards

Undefined Upper Middle Lower

Trinity

Trinity

Lower Glen Rose Upper Glen Rose

Thickness

(meters)

32–42

35

35

35–44

5–7.5

70–85

1.8–4.7

11

11.8

20.1

13.3

21.6

18.6

18.6

21.9

18

~35

~105

Aquifer Zone

Dolomitic (Kkd)

Basal nodular (Kkbn)

Cavernous (Kgrc)

Camp Bullis (Kgrcb)

Upper evaporite

 (Kgrue)

Fossiliferous (Kgrf)

A

B

C

D

E

F

Bexar

Cow Creek

Hammett

**

**

**

* **

* **

Confining unit

Lower evaporite

(Kgrle)

Upper Trinity aquifer (Upper_Glenrose in model)

**

Kirschberg Evaporite

(Kkke)

Bulverde (Kgrb)

Little Blanco (Kgrlb)

Twin Sisters (Kgrts)

Doeppenschmidt

(Kgrd)

Rust (Kgrr)

Not present

 *Not subdivided into members.

**Not mapped or subdivided hydrostratigraphically.

0 1,000 FEET

0 250 METERS

Plume 1

Plume 2

Parsons, 2017 

98 ̊38' 98 ̊37' 98 ̊36'

29 ̊43'

29 ̊42'

29 ̊41' EXPLANATION

PCE concentrations (μg/L)

1.4 (RL)

5 (MCL)

10

CSSA boundary

100

Camp Stanley encompasses approximately 4,000 acres and 

borders Camp Bullis, a much larger military base to the east and 

southeast. Between 1906 and 1907, six tracts of land were purchased 

by the U.S. Government and designated the Leon Springs Military 

Reservation. In October 1917, the installation was designated 

Camp Stanley. In 1933, Camp Stanley was selected as an ammunition 

depot, and its current mission remains the receipt, storage, issuance, 

and maintenance of ordnance, in addition to quality assurance testing 

and maintenance of military weapons and ammunition (Pearson and 

Murphy, 2004; U.S. Environmental Protection Agency [EPA], 2015).

Extended military operations at Camp Stanley since the early 

1900s have contaminated both the soils and groundwater in and off 

the base. Environmental investigations began at the CSSA in 1991 

after the Texas Department of Health discovered elevated levels of 

the dissolved cleaning solvents tetrachloroethane (PCE), trichloroethane 

(TCE), and cis-1,2-dichloroethylene (cis-1,2-DCE) above the 

regulatory maximum contaminant levels. Other volatile organic 

compounds (VOCs) were discovered in a sample from a CSSA well 

located near the center of the CSSA. Follow-up studies confirmed 

that VOC contamination in nearby wells had even higher contaminant 

concentrations. One source of solvent contamination, known as 

Plume 1 (fig. 2), was identified as a former oxidation pond. Another 

area of solvent contamination, known as Plume 2 (fig. 2), is located 

in the southwestern corner of the base (U.S. Army, 2001; EPA, 

2015). Starting in 1996, the first of 122 monitoring wells were 

installed (S.W. Pearson, Parsons, Austin, Texas, written commun., 

2017). For more information, go to the CSSA website at https://

www.stanley.army.mil/.

Figure 2. Camp Stanley Storage Activity (CSSA) plume concentrations 

(used with permission by Parsons, Austin, Texas. PCE, tetrachloroethylene;

 μg/L, microgram per liter; RL, reporting limit; MCL, maximum 

contaminant level). 

Figure 3. Lithostratigraphic and hydrostratigraphic correlation of mapped 

and modeled units in the Camp Stanley Storage Activity area (modified from 

Pantea and others, 2014). 

The release of these solvents resulted in the contamination of 

the Middle Trinity aquifer, which is the primary water source for 

the military base and surrounding areas. The lower member of the 

Glen Rose Limestone, and Bexar Shale and Cow Creek Limestone 

Members of the Pearsall Formation, form the Middle Trinity 

aquifer (fig. 3). The lower member of the Glen Rose Limestone 

was initially subdivided into six informal hydrostratigraphic 

units, known as units A–F (fig. 3) by Blome and Clark (2014). 

These informal units were later named and described by Clark 

and Morris (2015) as the Bulverde, Little Blanco, Twin Sisters, 

Doeppenschmidt, Rust, and Honey Creek hydrostratigraphic units 

(fig. 3). Locally, the underlying Bexar Shale Member serves as 

the lower confining unit between the water-bearing Glen Rose 

Limestone and the Cow Creek Limestone Member of the Pearsall 

Formation (Pearson and Murphy, 2004). 

Discussions with the CSSA Environmental Program Manager 

in 2009 led USGS personnel to coordinate several meetings with 

staff from the CSSA Environmental Office, the EPA, Parsons, and 

other CSSA cooperators. A number of topics were discussed at 

these meetings, and foremost among them was the need to better 

understand the local geology and the direction of contaminant flow 

both in the CSSA and residential areas south and west. Shortly 

thereafter, the USGS developed several Scope of Services Agreements 

(SOSAs) with the CSSA with the following objectives to be 

accomplished within a two-year period. 

Camp Stanley Storage Activity and Solvent Contamination
Upper Trinity

Middle Trinity

Lower Trinity

N

28

34

37

39

42

46

49

52

56

59

65

71

79

87

95

108

140

234

372

EXPLANATION

Apparent resistivity

ohm meters 115 kHz

0 1

1

2

2

3 KILOMETERS

0 3 MILES

The first objective identified was the construction of a 3D geohydrologic framework model 

using the 3D software called EarthVisionTM (EV). The interactive 3D model was built using 

surface hydrostratigraphic maps and subsurface borehole geophysical datasets of the base and 

areas west and south. A number of modifications were made to the SOSAs, which nearly 

doubled the size of the 3D model area. Included in the modifications was new field 

mapping to accurately locate all modeled faults and verify all well locations. The 

3D EV model (fig. 4) was completed in 2013 and contains 11 hydrostratigraphic 

units (fig. 3) in descending stratigraphic order: 1 model layer representing 

the Edwards aquifer; 2 model layers representing the Upper Trinity aquifer; 

and 9 model layers representing the Middle Trinity aquifer. The top of the 

Hammett Shale Member (fig. 3) is the lowermost model unit and was 

used to propagate and validate fault structures and drill-hole data.

Figure 4. Camp Stanley Storage Activity three-dimensional EarthVisionTM 

model showing model area, surface topology, subsurface model units, and fault 

structures (black near-vertical lines). Rocks of the Edwards aquifer (in pink) cap 

some of the hills in the southern part of the study area. View is from the east 

looking west (modified from Pantea and others, 2014).

Figure 5. Helicopter electromagnetic survey of the Camp Stanley Storage Activity and adjacent Camp Bullis, 

located just north of San Antonio, Texas. The highest electromagnetic frequency of 115 kilohertz (kHz) defines 

the geoelectric signatures of near surface strata (Smith and others, 2005).

Airborne Geophysics

The 3D EV model also incorporated 

geophysical data from the helicopter 

electromagnetic (HEM) survey of the CSSA 

and Camp Bullis (fig. 5) flown in December 

2003 (Smith and others, 2005). The objective 

for flying the HEM survey was to study the 

subsurface electrical resistivity of aquiferbearing geologic features. This survey also 

refined the location of mapped faults and 

suggested that many more unmapped faults 

exist. The higher order colors (reds) indicate 

resistive lithologies, such as limestone, 

whereas the lower order colors (blues) 

denote mudstone and shale. Heavy, wavy 

blue lines represent the major drainages of 

the study area, and the black lines denote 

the boundaries of the military bases. At the 

highest electromagnetic (EM) frequency 

(115 kHz), the exploration depth is only a 

few meters at most whereas the maximum 

exploration depth at the lowest frequency 

(400 Hz) is on the order of 100 meters.

1 Objective 1. Construction of the 3-D EV Model of the CSSA and Areas South and West
0 0.5 1 MILE

0 0.5 1 KILOMETER

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! ! ! ! ! !! ! ! !! !

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!! !

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!

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!!

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! !! ! ! ! !!!

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!!!

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!

! !

Kgrb

Kkke Kgrcb Kgruf Kgrc

Kgrc Kgrc

Kgrcb

Kgrcb

Kgrcb

Kgrlf Kgrcb

Kgrc

Kgrcb

Kgrcb Kgrlf

Kgrb Kgrlb

Kgruf

Kgrc

Kgruf

Kgrb

Kgrlf

Kgrb

Kgrlb

Kgrcb

Kgruf

Kgrcb

Kgrcb Kgrlb

Kgrcb

Kgruf

Kgrlf

Kgrlf

Kgruf

K Kgrlb grlf

Kgrlf

Kgrb

Kgrlf Kgrb

Kgrlf

Kgrlf

Kgrb

Kgrlf

Kgrlf

Kgrcb

Kgrlf

Kgrlf

Kgrlf

Kgruf

Kgruf

Kgrb

Kgrlf

Kgruf

Kgrcb

Kgrlf

Kgrb

Kgrlf

Kgrcb

Kgrb

Kgrue

Kgrlf

Kgrlf

Kgrlf

Kgrlf Kgrlf

Kgrlf

Kgrb

Kgrlf

Kgrb

Kgrlb

Kgrb

Kgrlf

Kgrb

Kgrts Kgrlb

Kgrd Kgrlb

Kgrr

Kgrlb Kgrd

98 ̊40'00" 98 ̊37'30"

29 ̊

42'

30"

29 ̊

40'

30"

MW35-LGR

B3-EXW02

I-10-4

MW36-LGR

CS-MW9-CC

CS-MW5-CC

Base modified from U.S. Geological Survey 1:24,000-scale digital data

Universal Transverse Mercator projection, zone 14

North American Datum of 1983

!

!

!

CS-MW5-CC

MW36-LGR

Kgrb

Kgrlb

Kgrts

Kgrd

Kgrr

Kkd

Kkke

Kkbn

Kgrc

Kgrcb

Kgrue

Kgruf

Kgrlf

Kgrle

Bulverde

Little Blanco

Twin Sisters

Doeppenschmidt

Rust

Kainer Formation

Edwards Group

Upper Glen Rose Limestone

Trinity Group

Lower Glen Rose Limestone

EXPLANATION

Hydrostratigraphic

member

Lower Cretaceous

Kirschberg Evaporite

Dolomitic

Basal nodular

Cavernous

Camp Bullis

Upper evaporite

Fossiliferous, upper

Fossiliferous, lower

Lower evaporite

Fault—Certain, 

dashed where inferred

Contact—Certain, 

dashed where inferred

Corbula bed

Camp Stanley 

Model 

Well with neutron log 

and map identifier

Well sampled for Helium Gas 

Injection Analysis and 

map identifier

Well

A

B

C

D

Edwards

Upper_GlenRose

EXPLANATION

E

F

Top_Bexar

Top_CowCreek

Top_Hammett

Fault

Geologic Mapping

The Lower Cretaceous geology of the CSSA area is characterized by 

alternating and intermixed sequences of shale, sandstone, carbonate, and 

evaporitic rocks assigned to the Trinity Group (Clark and others, 2016). 

The overlying Edwards Group contains carbonate, chert, and evaporitic 

rocks. The Trinity Group rocks were formed on a large, shallow marine 

carbonate platform (Commanche shelf), whereas Edwards Group rocks 

were formed in open marine to supratidal flat depositional environments.

The geologic map of northern Bexar County, Texas (Clark and 

others, 2009), was used to construct and constrain the CSSA 3D EV 

model (fig. 4). This map was later updated by Clark and others (2016) and 

describes and illustrates both the lithostratigraphy and hydrostratigraphy 

of the lower part of the Edwards aquifer down to the uppermost middle 

Trinity aquifer (fig. 6). Within the 3D EV model area, the lower part of 

the Edwards aquifer is present and includes the Dolomitic and Basal 

nodular hydrostratigraphic units. Rock outcrops associated with the 

Edwards aquifer cap only the hilltops south of the CSSA (fig. 6) and do 

not represent aquifer recharge areas within the 3D model area.

Figure 6. Geologic map of the Camp Stanley Storage 

Activity (CSSA) three-dimensional (3-D) model area (fig. 1) 

showing both lithostratigraphic and hydrostratigraphic units, 

mapped faults, and well locations (Clark and others, 2016). 

Red outline represents the CSSA boundary; blue-green 

outline represents the area encompassed by the CSSA 

3-D EarthVisionTM model of Pantea and others (2014).
Horst

Horst

Graben

N

A

B

C

D

Edwards

Upper_GlenRose

EXPLANATION

E

F

Top_Bexar

Top_CowCreek

Top_Hammett

Fault

N

~60 m

Fault Structures

Faults in northern Bexar County are part of the Miocene-age 

Balcones fault system historically called the Balcones fault zone 

(fig. 1). The southwest- to northeast-trending Balcones fault zone 

is an extensional system of normal en echelon faults that are 

downthrown to the southeast, and locally, high-angle normal faults 

are common. The CSSA 3D EV model (Pantea and others, 2014) 

revealed previously undetected horst and graben structures in the 

northeastern and southern parts of the study area. One graben was 

identified in the northeastern part of the study area and trends 

northeast to southwest (fig. 7). This graben structure 

may control or alter local groundwater flow as well

as flow direction.

Figure 7. Horst and graben structures in the northeastern 

part of the Camp Stanley Storage Activity model area. 

View is from the northeast looking southwest (Pantea 

and others, 2014).

Figure 8. View of faulted top of the Hammett Shale 

hydrostratigraphic model unit with cross section 

showing all hydrostatigraphic units in the 

three-dimensional EarthVisionTM model 

area (Pantea and others, 2014). 

View is towards the north; 

(m, meters).

In the CSSA model area, fault dips were interpreted to range 

from 52 to 75 degrees based on field mapping and drill-hole data 

(Clark, 2004). Although most fault displacements identified in the 

study area are 6 meters or less, a series of closely spaced faults 

near the southern boundary of the CSSA had greater displacements 

and one fault, located in the south-central part of the study area, 

exhibited up to 60 meters of displacement (fig. 8). 

1 Objective 1. Construction of the 3-D EV Model of the CSSA and Areas North and West
The USGS analyzed and interpreted borehole geophysical 

data from 12 wells logged by the USGS during 2012 to supplement 

existing borehole data under Objective 2. The geophysical data 

included nine wells located on the military facility and three off base. 

Of particular note was the logging of two wells, MW9-CC and 

MW5-LGR, by the USGS to depths of more than 470 and 450 feet, 

respectively. Refer to Blome and Clark (2014) for details on the 

Two cores from wells MW9-CC and MW5-LGR were 

provided by the CSSA and shipped to the USGS Core Research 

Center (Denver, Colorado) for storage, slabbing, and preparation 

for petrophysical analysis. Lithologic character and type of 

observed porosity for all Glen Rose Limestone hydrostratigraphic 

units were described by Blome and Clark (2014) following the 

porosity classification of Choquette and Pray (1970) and the 

classification system of Dunham (1962).

Under Objective 3, 55 core plugs from well MW5-LGR, 

from intervals representing the lower member of the Glen Rose 

Limestone (fig. 3), were submitted to Weatherford Laboratories, 

Inc., (Golden, Colorado) for helium-gas-injection porosity and 

permeability analyses. Gas injection (also called gas expansion) 

is one of the accepted methods for measuring core or plug 

porosity and permeability and is preferred when analyzing 

poorly consolidated samples. 

References

Blome, C.D., Faith, J.R., and Ozuna, G.B., 2007, Geohydrologic framework of the Edwards and Trinity aquifers,

south-central Texas: U.S. Geological Survey Fact Sheet 2006–3145, 6 p., accessed January 17, 2017, at 

https://pubs.usgs.gov/fs/2006/3145/.

Blome, C.D., and Smith, D.V., 2012, Evolution of 3-D geologic framework modeling and its application to 

groundwater flow studies: U.S. Geological Survey Fact Sheet 2012–3106, 6 p., accessed January 24, 2017, 

at https://pubs.usgs.gov/fs/2012/3106/.

Blome, C.D., and Clark, A.K., 2014, Key subsurface data help to refine Trinity aquifer hydrostratigraphic units, 

south-central Texas: U.S. Geological Survey Data Series 768, 1 sheet, accessed March 3, 2017, at 

https://doi.org/10.3133/ds768.

Choquette, P.W., and Pray, L.C., 1970, Geologic nomenclature and classification of porosity in sedimentary 

carbonates: American Association of Petroleum Geologists, v. 54, no. 2, p. 207–250.

Christenson, Scott, Osborn, N.J., Neel, C.R., Faith, J.R., Blome, C.D., Puckette, James, and Pantea, M.P., 2011, 

Hydrology and simulation of groundwater flow in the Arbuckle-Simpson aquifer, south-central Oklahoma: 

U.S. Geological Survey Scientific Investigations Report 2011–5029, 104 p., accessed June 6, 2017, at 

https://pubs.usgs.gov/sir/2011/5029/.

Clark, A.K., 2004, Geologic framework and hydrogeologic characteristics of the Glen Rose Limestone, 

Camp Stanley Storage Activity, Bexar County, Texas: U.S. Geological Survey Scientific Investigations Map 

2831, 1 sheet, scale 1:24,000, accessed April 19, 2017, at https://pubs.usgs.gov/sim/2005/2831/.

Clark, A.K., Golab, J.A., and Morris, R.R., 2016, Geologic framework and hydrostratigraphy of the 

Edwards and Trinity aquifers within northern Bexar and Comal Counties, Texas: U.S. Geological Survey 

Scientific Investigations Map 3366, 1 sheet, scale 1:24,000, pamphlet, 28 p., accessed May 3, 2017, at 

https://doi.org/10.3133/sim3366.

Clark, A.R., Blome, C.D., and Faith, J.R., 2009, Map showing the geology and hydrostratigraphy of 

the Edwards aquifer catchment area, northern Bexar County, south-central Texas: U.S. Geological 

Survey Open-File Report 2009–1008, 24 p., 1 pl., scale 1:24,000, accessed August 11, 2017, at 

https://pubs.usgs.gov/of/2009/1008/.

Dunham, R.J., 1962, Classification of carbonate rocks according to depositional texture, in Ham, W.E., ed., 

Classification of Carbonate Rocks Symposium: American Association of Petroleum Geologists Memoir 1, 

p. 108–121, http://archives.datapages.com/data/specpubs/carbona2/data/a038/a038/0001/0100/0108.htm.

Pantea, M.P., Blome, C.D., and Clark, A.K., 2014, Three-dimensional model of the hydrostratigraphy and 

structure of the area in and around the U.S. Army–Camp Stanley Storage Activity Area, northern 

Bexar County, Texas: U.S. Geological Survey Scientific Investigations Report 2014–5074, 13 p., accessed 

February 15, 2017, at https://doi.org/10.3133/sir20145074. 

Pearson, Scott, and Murphy, Brian, 2004, A case study of traditional and alternative monitoring techniques for 

solvent contamination within fractured bedrock: 2004 U.S. EPA/NGWA Fractured Rock Conference, State 

of the science and measuring success in remediation, Portland, Maine, p. 239–251, accessed April 3, 2017, 

at https://clu-in.org/products/siteprof/2004fracrockconf/cdr_pdfs/indexed/group1/239.pdf.

Smith, B.D., Cain, M.J., Clark, A.K., Moore, D.W., Faith, J.R., and Hill, P.L., 2005, Helicopter electromagnetic 

and magnetic survey data and maps, northern Bexar County, Texas: U.S. Geologic Survey Open-File 

Report 2005–1158, 119 p., accessed May 24, 2017, at https://pubs.usgs.gov/of/2005/1158/.

U.S. Army, 2001, Camp Stanley Storage Activity—Soil and groundwater contamination: U.S. Department of 

the Army Fact Sheet, no. 2, 2 p., accessed March 20, 2017, at http://www.stanley.army.mil/Volume1-6/

FactSheets/02.pdf.

U.S. Environmental Protection Agency [EPA], 2015, Statement of basis, RVRA corrective action, Camp 

Stanley Storage Activity, Boerne, Texas: U.S. Environmental Protection Agency, accessed March 21, 2017, 

at https://www.epa.gov/tx/federal-facilities-texas.

logging of these wells. Of the 12 wells, 4 were logged with a 

neutron geophysical tool to obtain effective porosity data. Neutron 

porosity measurements employ a neutron source to measure the 

hydrogen index in a reservoir, which is directly related to porosity 

in downhole formations. Borehole geophysical data collection 

included three mobilizations of logging equipment that were 

operated and maintained by the USGS (https://tx.usgs.gov/).

Porosity values (ambient, in porosity percent) for the lower 

member of the Glen Rose Limestone range from 6.0 percent 

to 30.2 percent, with a mean porosity value of 17.8 percent. 

Permeability values (to air, in millidarcys) were 0.0043 to 406 with 

a mean permeability of 14.7 (Blome and Clark, 2014). The helium 

injection porosity and permeability values and neutron geophysical 

log data will be used to construct future 3D property models for 

areas in and around the CSSA. Much of the funding for the CSSA 

3D modeling and downhole geophysical and petrophysical data 

was through shared funding from the USGS National Cooperative 

Geologic Mapping Program and the CSSA Environmental Program.

ISSN 2327-6916 (print) ISSN 2327-6932 (online) https://doi.org/10.3133/fs20173090

By Charles D. Blome and Allan K. Clark

Prepared in cooperation with Camp Stanley Storage Activity and Parsons Corporation

Contacts:

Charles D. Blome

U.S. Geological Survey

MS 980, Box 25046, DFC

Denver, CO 80225

cblome@usgs.gov

Allan K. Clark

U.S. Geological Survey

5563 DeZavala Road, Suite 290

San Antonio, TX 78249

akclark@usgs.gov

Acknowledgments

The authors would like to thank the following for their help and support 

on this project: the management and staff of the U.S. Army Camp Stanley 

Storage Activity Environmental Program and Parsons Corporation, 

Austin, Texas, for their help and support on this project. Special thanks 

goes to Scott Pearson (Parsons) and David V. Smith (USGS) for their helpful 

peer reviews, and to Diana Pedraza (USGS) for her help with the GIS 

and drafting of figures.

3

2

Objective 3. Porosity and Permeability Measurements

Objective 2. Downhole Geophysical Logging