Hydraulic and Solute-Transport Properties 

and Simulated Advective Transport of 

Contaminated Ground Water in a FracturedRock Aquifer at the Naval Air Warfare 

Center, West Trenton, New Jersey, 2003

By Jean C. Lewis-Brown, Glen B. Carleton, and Thomas E. Imbrigiotta

U.S. Department of the Interior

U.S. Geological Survey

Prepared in cooperation with the U.S. DEPARTMENT OF THE NAVY

Scientific Investigations Report 2005-5049
U.S. Department of the Interior

P. Lynn Scarlett, Acting Secretary

U.S. Geological Survey

P. Patrick Leahy, Acting Director

U.S. Geological Survey, Reston, Virginia: 2006

For sale by U.S. Geological Survey, Information Services

Box 25286, Denver Federal Center

Denver, CO 80225

For more information about the USGS and its products:

Telephone: 1-888-ASK-USGS

World Wide Web: http://www.usgs.gov/

Any use of trade, product, or firm names in this publication is for descriptive purposes only and does not imply 

endorsement by the U.S. Government.

Although this report is in the public domain, permission must be secured from the individual copyright owners to reproduce any copyrighted materials contained within this report.
 iii

CONTENTS

Abstract. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Purpose and scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Hydrogeologic framework . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Site selection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Hydraulic and solute-transport properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Transmissivity and storage coefficient. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Field methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Analysis methods. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Estimated values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Longitudinal dispersivity and effective porosity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Field methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Analysis methods. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Estimated values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Simulated advective transport of contaminated ground water . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Travel time and velocity under ambient conditions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Discharge points during operation of pump-and-treat system. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Suggestions for additional work . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Summary and conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

References cited . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Appendix 1: Aquifer-test solution parameters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
iv 

FIGURES

Figure 1. Map showing location of the Naval Air Warfare Center and vicinity, West Trenton, New

Jersey, and extent of the grid of the ground-water-flow model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2

2.. Geologic section A-A’ showing bedding units and fault zone at the Naval Warfare Center, 

West Trenton, New Jersey . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

3. Map showing locations of wells used in aquifer tests and tracer tests, 2003, and line of 

section A-A’ at the Naval Air Warfare Center, West Trenton, New Jersey. . . . . . . . . . . . . . . . . . . . . . . . . . .6

4. Graphs showing observed drawdown in observation well 20BR during pumping of well BRP2,

July 1-3, 2003, and drawdown computed from three analytical solutions, Naval Air Warfare Center, 

West Trenton, New Jersey . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

5. Graphs showing observed drawdown in observation well 56BR during pumping of well 

BRP2, July 1-3, 2003, and drawdown computed from three analytical solutions, Naval Air Warfare 

Center, West Trenton, New Jersey . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

6. Graphs showing observed drawdown in observation well BRP3 during pumping of well 

15BR, June 26-30, 2003, and drawdown computed from three analytical solutions, Naval Air Warfare 

Center, West Trenton, New Jersey . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

7. Graphs showing observed drawdown in observation well 41BR during pumping of well

16BR, June 11-12, 2003, and drawdown computed from three analytical solutions, Naval Air Warfare 

Center, West Trenton, New Jersey . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

8. Graphs showing observed drawdown in observation well 53BR during pumping of well 

41BR, June 17, 2003, and drawdown computed from three analytical solutions, Naval Air Warfare 

Center, West Trenton, New Jersey . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

9. Graph showing observed bromide concentration in withdrawal well BRP2 resulting from

injection of bromide tracer at well 20BR at the Naval Air Warfare Center, West Trenton, New Jersey, 

and the dimensionless concentration computed from the analytical solution of Welty and Gelhar 

(1994) for a doublet tracer test with longitudinal dispersivity (αL) divided by distance between wells (L) 

of 0.07 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

10. Graph showing observed bromide concentration in withdrawal well 15BR resulting from

injection of bromide tracer at well BRP3 at the Naval Air Warfare Center, West Trenton, New Jersey, 

and the dimensionless concentration computed from the analytical solution of Welty and Gelhar 

(1994) for a doublet tracer test with longitudinal dispersivity (αL) divided by distance between wells (L) 

of 0.07 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

11. Graph showing observed bromide concentration in withdrawal well 16BR resulting from

injection of bromide tracer at well 41BR at the Naval Air Warfare Center, West Trenton, New Jersey, 

and the dimensionless concentration computed from the analytical solution of Welty and Gelhar 

(1994) for a doublet tracer test with longitudinal dispersivity (αL) divided by distance between wells (L) 

of 0.04 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

12. Map showing finite-difference grid for the ground-water-flow model, Naval Air Warfare Center, West 

Trenton, New Jersey, and vicinity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

13. Map showing simulated discharge locations of ground water at and near contaminated wells at the 

Naval Air Warfare Center, West Trenton, New Jersey (with no recovery wells pumped) . . . . . . . . . . 25

14. Map showing simulated discharge locations of ground water at and near contaminated wells at the 

Naval Air Warfare Center, West Trenton, New Jersey (with recovery-well network II or III in operation) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
 v

TABLES

Table 1. Bedding units at the Naval Air Warfare Center, West Trenton, New Jersey. . . . . . . . . . . . . . . . . . . . . . . . .3

2. Wells used in aquifer and tracer tests, Naval Air Warfare Center, West Trenton, New Jersey, 

2003 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

3. Pumping rates and duration of pumping at withdrawal wells during aquifer tests, Naval Air

Warfare Center, West Trenton, New Jersey, 2003 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

4. Pumping rates at recovery wells during aquifer tests, Naval Air Warfare Center, West Trenton,

New Jersey, 2003 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8

5. Assumptions and conditions inherent in solution methods used to analyze data from aquifer tests, 

Naval Air Warfare Center, West Trenton, New Jersey, 2003 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9

6. Transmissivity and storage coefficient estimated from aquifer-test data, Naval Air Warfare Center, 

West Trenton, New Jersey, 2003 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

7. Values of hydraulic conductivity estimated from aquifer tests, slug tests, and calibration of a digital 

model, Naval Air Warfare Center, West Trenton, New Jersey . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

8. Rates and duration of pumping at withdrawal wells and injection at injection wells during tracer 

tests, Naval Air Warfare Center, West Trenton, New Jersey, 2003 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

9. Pumping rates at recovery wells during tracer tests, Naval Air Warfare Center, West Trenton, 

New Jersey, 2003 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

10. Longitudinal dispersivity and effective porosity estimated from tracer-test data, Naval Air Warfare 

Center, West Trenton, New Jersey, 2003 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

11. Well-construction and location data for selected wells at the Naval Air Warfare Center, West 

Trenton, New Jersey. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

12. Travel time and average linear velocity of flow paths from contaminated wells at the Naval Air 

Warfare Center, West Trenton, New Jersey, under ambient flow conditions. . . . . . . . . . . . . . . . . . . . . . 22

13. Recovery wells in pump-and-treat system, Naval Air Warfare Center, West Trenton, New 

Jersey. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

14. Simulated discharge points of ground-water flow paths from contaminated wells at the Naval Air 

Warfare Center, West Trenton, New Jersey, during operation of pump-and-treat system. . . . . . . . . 28
vi 

Conversion Factors and Datum

Multiply By To obtain

Length

foot (ft) 0.3048 meter (m)

mile (mi) 1.609 kilometer (km)

Area

square foot (ft2) 929.0 square centimeter (cm2)

square foot (ft2) 0.09290 square meter (m2)

Volume

gallon (gal) 3.785 liter (L)

gallon (gal) 0.003785 cubic meter (m3)

gallon (gal) 3.785 cubic decimeter (dm3)

Flow rate

foot per minute (ft/min) 0.3048 meter per minute (m/min)

foot per day (ft/d) 0.3048 meter per day (m/d)

gallon per minute (gal/min) 0.06309 liter per second (L/s)

Mass

ounce, avoirdupois (oz) 28.35 gram (g)

Hydraulic conductivity

foot per day (ft/d) 0.3048 meter per day (m/d)

Transmissivity*

foot squared per day (ft2/d) 0.09290 meter squared per day (m2/d)

Vertical coordinate information is referenced to the North American Vertical Datum of 1988 

(NAVD 88). Historical data collected and stored as National Geodetic Vertical Datum of 1929 

(NGVD 29) have been converted to NAVD 88 for this publication.

Horizontal coordinate information is referenced to the North American Datum of 1983 (NAVD 83). 

Historical data collected and stored as North American Datum of 1927 (NAD 27) have been con- verted to NAD 83 for this publication.

Altitude, as used in this report, refers to distance above the vertical datum.

*Transmissivity: The standard unit for transmissivity is cubic foot per day per square foot times 

foot of aquifer thickness [(ft3/d)/ft2

]ft. In this report, the mathematically reduced form, foot 

squared per day (ft2

/d), is used for convenience.

Concentrations of chemical constituents in water are given either in milligrams per liter (mg/L) or 

in grams per liter (g/L).
Hydraulic and Solute-Transport Properties and Simulated 

Advective Transport of Contaminated Ground Water in a 

Fractured-Rock Aquifer at the Naval Air Warfare Center,

West Trenton, New Jersey, 2003

By: Jean C. Lewis-Brown, Glen B. Carleton, and Thomas E. Imbrigiotta

Abstract

Volatile organic compounds, predominantly trichloroethylene and its degradation products, have been detected in 

ground water at the Naval Air Warfare Center (NAWC), West 

Trenton, New Jersey. An air-stripping pump-and-treat system 

has been in operation at the NAWC since 1998. An existing 

ground-water-flow model was used to evaluate the effect of a 

change in the configuration of the network of recovery wells in 

the pump-and-treat system on flow paths of contaminated 

ground water. 

The NAWC is underlain by a fractured-rock aquifer composed of dipping layers of sedimentary rocks of the Lockatong 

and Stockton Formations. Hydraulic and solute-transport properties of the part of the aquifer composed of the Lockatong Formation were measured using aquifer tests and tracer tests. The 

heterogeneity of the rocks causes a wide range of values of each 

parameter measured. Transmissivity ranges from 95 to 1,300 

feet squared per day; the storage coefficient ranges from

9 x 10-5 to 5 x 10-3; and the effective porosity ranges from 

0.0003 to 0.002. 

The average linear velocity of contaminated ground water 

was determined for ambient conditions (when no wells at the 

site are pumped) using an existing ground-water-flow model, 

particle-tracking techniques, and the porosity values determined in this study. The average linear velocity of flow paths 

beginning at each contaminated well and ending at the streams 

where the flow paths terminate ranges from 0.08 to 130 feet per 

day. As a result of a change in the pump-and-treat system (adding a 165-foot-deep well pumped at 5 gallons per minute and 

reducing the pumping rate at a nearby 41-foot-deep well by the 

same amount), water in the vicinity of three 100- to 165-footdeep wells flows to the deep well rather than the shallower well.

Introduction

Volatile organic compounds (VOCs), predominantly 

trichloroethylene (TCE) and its degradation products cis-1,2-

dichloroethylene (DCE) and vinyl chloride (VC), are the primary contaminants of concern detected in ground water in the 

fractured-rock aquifer at the Naval Air Warfare Center 

(NAWC), West Trenton, N.J. (International Technology Corporation, 1994) (fig. 1). In June 1997, the highest concentrations of TCE, DCE, and VC detected in wells at the NAWC 

were 88, 52, and 21 mg/L, respectively (Lacombe, 2000). A 

pump-and-treat system consisting of six recovery wells and an 

air-stripping treatment system has been operating at the NAWC 

since 1998. The U.S. Geological Survey (USGS), in cooperation with the U.S. Department of the Navy, conducted an

11-year, multiphase hydrogeologic investigation of the NAWC. 

In earlier phases of the investigation, Lacombe (2000, 2002) 

determined the hydrogeologic framework, and Lewis-Brown 

and Rice (2002) developed a digital model to simulate, and 

evaluate the effects of various recovery-well networks on, 

ground-water flow at the NAWC. 

The purpose of the current phase of the investigation was 

to (1) estimate values of hydraulic and solute-transport properties of the fractured-rock aquifer, (2) estimate the velocity and 

travel time of contaminated ground water if the existing pumpand-treat system at the NAWC were replaced by a non-pumping 

remediation technique, and (3) evaluate the effect on flow paths 

of contaminated ground water of a change in the configuration 

of the network of recovery wells in the pump-and-treat system.

Values of transmissivity, storage coefficient, effective 

porosity, longitudinal dispersivity, and average linear velocity 

presented in this report can be used to investigate the feasibility 

of alternative, non-pumping remediation techniques at the 

NAWC. These values also can be used in investigations conducted at the NAWC as part of the USGS Toxic Substances 

Hydrology Program (TSHP) to identify the geochemical and 

microbiological processes that affect migration and natural 

attenuation of chlorinated solvents in fractured sedimentary 

rocks. These processes are being studied as part of the TSHP’s 

overall initiative to provide objective and reliable scientific 

information needed to develop policies and practices that help 

avoid exposure to toxic substances, mitigate environmental 

deterioration from contaminants, provide cost-effective cleanup 

and waste-disposal strategies, and reduce risk of future contamination.
I- 95

Area shown in figures 3,

13, and 14

NAWC

40

15'

00"

40

16'

00"

74 51'00" 74 50'00" 74 49'00" 74 48'00" 74 47'00" 74 46'00"

40

17'

00"

DELAWARE AND RARITAN CANAL

GOLD RUN

DELAWARE RIVER

REEDERS CREEK

ST1

ST2

WEST BRANCH

SHABAKUNK CREEK

Naval Air Warfare Center (NAWC)

Stream

Road

Fault trace at land surface

Extent of model grid

Unnamed stream 1

Unnamed stream 2

Unnamed stream 3

EXPLANATION 0 4,000 FEET

0 1,000 METERS

ST3

ST1

ST2

ST3

75°

41°

40°

39°

74°

0

0

10

10

20 MILES

20 KILOMETERS

MERCER

COUNTY

NEW JERSEY

Map

location

2 Hydraulic and Solute-Transport Properties at the Naval Air Warfare Center, West Trenton, New Jersey, 2003

Figure 1. Location of the Naval Air Warfare Center and vicinity, West Trenton, New Jersey, and extent of the grid of the ground-waterflow model.
Introduction 3

Purpose and Scope

This report presents estimates of the hydraulic and solutetransport properties of the fractured-rock aquifer at the NAWC. 

The velocity and travel time of contaminated ground water 

under the non-pumping conditions that would exist if the existing pump-and-treat system were replaced by a non-pumping 

remediation technique are estimated. The effect of a change in 

the configuration of the network of recovery wells in the pumpand-treat system on flow paths of contaminated ground water is 

evaluated. The estimates of velocity and travel time and the 

evaluation of effects on flow paths were made using an existing 

ground-water-flow model and effective-porosity values determined from the results of tracer tests.

This report documents the results of five aquifer tests and 

three tracer tests conducted at the NAWC during the summer of 

2003. The transmissivity and storage coefficient determined 

from each aquifer test are reported, as are the effective porosity 

and longitudinal dispersivity from each tracer test. These tests 

were conducted in five small (less than 3,000 ft2

) areas at the 

NAWC.

Hydrogeologic Framework

The hydrogeologic framework underlying the NAWC (fig. 

2) is described in detail by Lacombe (2000, 2002) and is summarized here. The NAWC is underlain by about 0 to 10 ft of 

unconsolidated sediments that are unsaturated much of the time. 

Dipping layers of fractured mudstone, siltstone, and sandstone 

of the Lockatong and Stockton Formations are beneath the 

unconsolidated sediments. Lacombe (2000) identified 16 bedding units (table 1) in the Lockatong and Stockton Formations 

at the NAWC. The units strike N. 60o E. to N. 70o E. and dip 15o

to 20o

 NW. Each bedding unit consists of several water-bearing 

zones alternating with confining zones. These bedding units 

generally are 20 to 35 ft thick and are differentiated primarily 

on the basis of lithologic characteristics. The 16 bedding units 

comprise a fractured-rock aquifer. Water is transmitted primarily through fractures and joints in the rocks. Shallow rocks 

(less than about 40-70 ft deep) are more weathered and more 

fractured than deeper, more competent rocks.

A fault (fig. 2) cuts through the bedding units and acts as a 

nearly impermeable boundary to ground-water flow. The fault 

is at or near the contact between the Stockton and Lockatong 

Formations. The fault strikes about N. 70o E. and dips about 40o 

SE. In rock cores collected from the fault zone, the rocks are 

weathered extensively and fractured, and the fractures are completely filled with clay. Dry clay as much as 60 ft thick was 

found in rock cores from some parts of the fault zone. Abundant 

clay in the fault zone and the absence of drawdown in wells on 

the south side of the fault when wells on the north side were 

pumped indicate that the fault is a boundary to ground-water 

flow (Lacombe, 2000).

Table 1. Bedding units at the Naval Air Warfare Center, West Trenton, New Jersey.

[Modified from Lacombe, 2000]

Geologic unit Bedding unit Predominant lithology

Lockatong Formation L23 Mudstone, light to dark gray, laminated, slightly calcareous

L22 Mudstone, dark gray and green-gray

L21 Mudstone, gray, platy, massive, interbedded, medium hard

L20 Mudstone, gray

L19 Mudstone, gray, hard to medium hard, with calcareous and soft 

brown mudstone seams

L18 Siltstone and mudstone, light to dark olive green or black, massive, 

bioturbated; some strata finely laminated; strongly calcareous

L17 Mudstone, red-brown to green-gray brown

L16 Mudstone, argillite, and shale, light green to gray and black

L15 Mudstone, red-brown and green-gray, soft, slightly broken, massively 

bedded, calcareous

L14 Mudstone, dark gray to green-gray

L13 Mudstone, dark gray

Stockton Formation S15 Sandstone, brown, medium hard

S14 Sandstone, gray-white, medium hard

S13 Mudstone, red, hard, massive

S12 Sandstone, gray-white

S11 Mudstone, red
S-11

S-12

S-13 S-14

0 200 400 600 800 

-300

180

-250-200-150-100

-50

0

50

100150

EXPLANATION

Land surfaceBase of unconsolidated sedimentsTop of competent bedrockBedding-unit contactLimit of fault zoneCenter of fault zoneBedding-unit number as defined by Lacombe (2000)

Fault zone

S-11, L-18

A 

DATUM IS NAVD 88 DISTANCE, IN FEET

ALTITUDE, IN FEET

VERTICAL EXAGGERATION x 1.5

UNCONSOLIDATED SEDIMENTS

WEATHERED BEDROCK

LOCKATONG FORMATION

STOCKTON FORMATION

SOUTH 

Direction of movement along fault

Figure 2. Geologic section A-A’ showing bedding units and fault zone at the Naval Warfare Center, West Trenton, New Jersey.
Hydraulic and Solute-Transport Properties 5

Site Selection

Pairs of existing wells were chosen for inclusion in the 

aquifer and tracer tests by using the following criteria: (1) The 

wells are open to the same bedding unit. (2) The wells are 

hydraulically connected--that is, the water level in one well 

decreases when the other well is pumped. (3) The distance 

between the wells is great enough to allow some measurable 

dispersion to occur, yet small enough to allow the tracer concentration to be measurable in the withdrawal well. (4) The 

injection well is hydraulically able to accept water, and the 

withdrawal well is able to withdraw water at a rate sufficient to 

allow injection of a mass of tracer large enough to result in 

detectable concentrations at the withdrawal well. (5) The withdrawal well is connected to the pump-and-treat system so the 

pumped water can be treated on site, as required by the N.J. 

Department of Environmental Protection (NJDEP). (6) The 

wells are open to the specific bedding units identified by 

Lacombe (2000) in which the highest concentrations of VOCs 

at the site have been detected (bedding units L17 and L19, fig. 

2).

Thirteen recovery wells are connected to the pump-andtreat system and were available to be used as withdrawal wells 

in the aquifer and tracer tests. Most of these wells are in bedding 

units L17 and L19. On the basis of results of an evaluation of 

water-level data, the hydrogeologic framework, and the proximity of potential observation and injection wells to the available recovery wells, eight wells were selected for aquifer and 

tracer testing (table 2). Five pairs of wells were used for aquifer 

testing. Recovery wells BRP2, 15BR, 16BR, and 41BR were 

used as withdrawal wells in the aquifer tests. When well BRP2 

was pumped, drawdown data in two observation wells, 20BR 

and 56BR, were analyzed. For purposes of this report, these two 

data sets are treated as separate aquifer tests, referred to as the 

BRP2-20BR aquifer test and the BRP2-56BR aquifer test, 

respectively. Similarly, the other three aquifer tests are referred 

to as the 15BR-BRP3 aquifer test, the 16BR-41BR aquifer test, 

and the 41BR-53BR aquifer test. Three pairs of wells were used 

for tracer testing. Recovery wells BRP2, 15BR, and 16BR were 

used as withdrawal wells in the tracer tests. For purposes of this 

report, the test in which well BRP2 was pumped while tracer 

was being injected into well 20BR is referred to as the BRP2-

20BR tracer test. Similarly, the other two tracer tests are 

referred to as the 15BR-BRP3 tracer test and the 16BR-41BR 

tracer test, respectively. The locations of the wells are shown in 

figure 3.

Aquifer testing was planned at all five well pairs listed in 

table 2. Tracer testing also was planned at each of these well 

pairs except the BRP2-56BR pair. This well pair was included 

in aquifer testing because, at the time the tests were conducted, 

well 56BR was a potential candidate for addition to the network 

of wells pumped in the pump-and-treat system. This well pair 

was not suitable for tracer testing, however, because the distance between the wells was too great to ensure that the tracer 

concentrations at the withdrawal well would be measurable.

Hydraulic and Solute-Transport Properties

The transmissivity, storage coefficient, longitudinal dispersivity, and effective porosity of the fractured-rock aquifer at 

the NAWC were estimated from the results of aquifer tests and 

tracer tests. The tests were conducted in parts of the aquifer 

composed of the Lockatong Formation, in the two bedding units 

(L17 and L19) in which the highest concentrations of VOCs 

have been detected.

Table 2. Wells used in aquifer and tracer tests, Naval Air Warfare Center, West Trenton, New Jersey, 2003.

Well Pair

Bedding unit 

(Lacombe, 

2000)

Open interval

of withdrawal 

well

(feet below land 

surface

Open interval of 

observation/

injection well 

(feet below land 

surface)

Horizontal 

distance

at land 

surface 

between 

wells

(feet)

Distance 

between 

mid-point 

of open 

intervals 

of wells 

(feet)

Withdrawal 

well

Observation/ 

injection well

BRP2 20BR L17 25 - 45 28 - 43 97 97

BRP21 56BR1 L17 25 - 45 140 - 165 253 279

15BR BRP3 L19 26 - 41 25 - 40 92 93

16BR 41BR L19 40 - 65 85 - 110 84 94

41BR2 53BR2 L19 85 - 110 95 - 120 138 139

1

 No tracer test was planned at this well pair.

2 A tracer test was planned but not conducted at this well pair because well 53BR overflowed when water was injected into it.
A

Fault zone - shows the fault contact at an altitude

of 150 feet above NAVD 88 (approximate land surface)

Line of section and identifier

Well used in aquifer tests and tracer tests

Well used only in aquifer tests

EXPLANATION

A

Gold Run (west branch)

BUILDING 40

BUILDING 41

SITE 1

BUILDING 42

BUILDING 21

BUILDING 22

0 100 200 300 FEET

0 50 METERS

A'

A'

Swamp

Building

Fence--approximate boundary of

Naval Air Warfare Center property

41BR

16BR

20BR

BRP2

15BR

BRP3

53BR

20BR

53BR

56BR

74 48'30"

74 48'45"

40 16'00" 40 16'15"

75

41

40

39

74

0

0

10

10

20 MILES

20 KILOMETERS

MERCER

COUNTY

NEW JERSEY

Map

location

6 Hydraulic and Solute-Transport Properties at the Naval Air Warfare Center, West Trenton, New Jersey, 2003

Figure 3. Locations of wells used in aquifer tests and tracer tests, 2003, and line of section A-A’ at the Naval Air Warfare Center, West 

Trenton, New Jersey.
Hydraulic and Solute-Transport Properties 7

Transmissivity and Storage Coefficient

Aquifer tests were conducted to estimate the transmissivity 

and storage coefficient of the fractured-rock aquifer in the area 

of each well pair for which subsequent tracer testing was 

planned. Three analytical methods were used to analyze data 

from each test.

Field Methods

Water levels in observation wells and withdrawal wells 

were recorded using down-hole pressure-transducer digital data 

recorders in six of the wells and float-type digital recorders in 

the other two wells. Generally, water levels were recorded at 5-

second intervals during the first 1 to 2 hours after pumps were 

turned on or off and at 1-minute intervals thereafter. Selected 

recovery wells used in the pump-and-treat system were used as 

withdrawal wells in the aquifer tests, and submersible pumps 

previously installed in the wells for use in the pump-and-treat 

system were used in the aquifer tests. The pumping rates at the 

withdrawal wells during the aquifer tests are listed in table 3. 

The pumping rates were monitored using flow meters installed 

at each well, and flow was adjusted as needed to maintain constant rates.

To avoid the possibility of changes in stress to the groundwater-flow system caused by unexpected shutdowns of recovery wells (for example, as a result of system malfunction), it 

would have been beneficial to shut down all of the recovery 

wells except the one used as a withdrawal well in the test. This 

was not done, however, in order to keep the pump-and-treat system operating to the maximum extent practicable in accordance 

with NJDEP regulations. Consequently, pumps in some recovery wells in the pump-and-treat system continued operating 

during the tests, but pumps in wells less than 600 ft from and 

open to the same bedding unit as the aquifer-test withdrawal 

well were shut down at least 24 hours prior to each test and 

remained off during the test. Recovery wells pumped during 

each aquifer test are listed in table 4.

Analysis Methods

Three analytical solutions were used to analyze data from 

each aquifer test:

1. the Neuman (1974) solution for an aquifer test in an 

unconfined aquifer,

2. the Theis (1935) solution for an aquifer test in a confined 

aquifer, and

3. the Hantush (1962) solution for an aquifer test in a 

wedge-shaped confined aquifer.

All three of these methods involve matching observed 

drawdown data from the test to drawdown computed from analytical solutions. Matching was performed using the computer 

program AQTESOLV (Duffield, 2000). Although shallow parts 

of the aquifer generally are considered to be unconfined and 

deeper parts are considered to be confined, the depth at which 

the transition from unconfined to confined conditions occurs is 

not clear (Lacombe, 2000). Consequently, solutions for both 

confined and unconfined aquifers were attempted for each well 

pair. The Hantush solution for a wedge-shaped confined aquifer 

was used because the hydraulic properties of the bedding units 

at the NAWC are assumed to be similar to those of a wedgeshaped aquifer. In a wedge-shaped aquifer, the transmissivity 

decreases as the wedge becomes thinner. In the bedding units at 

the NAWC, the transmissivity in each bedding unit is assumed 

to decrease with depth below land surface because the hydraulic 

conductivity decreases with depth (Lewis-Brown and Rice, 

2002). In well pairs in which the withdrawal well is open at a 

different depth than the observation well, the effect of decreasing hydraulic conductivity with depth is assumed to be similar 

to the effect of decreasing thickness in a wedge-shaped aquifer.

Table 3. Pumping rates and duration of pumping at withdrawal wells during aquifer tests, Naval Air Warfare Center, West Trenton, 

New Jersey, 2003.

Well pair

Bedding unit to which well pair is 

open (Lacombe, 2000)

Pumping rate

(gallons per minute)

Duration of pumping 

(minutes)

Withdrawal 

well

Observation 

well

BRP2 20BR L17 6.6 1,690

BRP2 56BR L17 6.6 1,690

15BR BRP3 L19 14.9 5,570

16BR 41BR L19 1.3 1,300

41BR 53BR L19 10.2 690
8 Hydraulic and Solute-Transport Properties at the Naval Air Warfare Center, West Trenton, New Jersey, 2003

Table 4. Pumping rates at recovery wells during aquifer tests, Naval Air Warfare Center, West Trenton, New Jersey, 2003.

[Pumping rates listed in this table are for additional wells being pumped during aquifer tests to maintain operation of the pump-and-treat system 

at the Naval Air Warfare Center; WW, well used as withdrawal well during the given aquifer test]

Recovery well

Bedding unit to which recovery 

well is open (Lacombe, 2000)

Pumping rate at recovery well (gallons per minute)

BRP2-20BR 

aquifer test and 

BRP2-56BR 

aquifer test

15BR-BRP3 

aquifer test

16BR-41BR 

aquifer test

41BR-53BR 

aquifer test

BRP2 L17 WW 0 6.6 6.6

20BR L17 0 0 8.5 8.5

48BR L17 0 13.5 13.5 13.5

56BR L17 0 0 0 0

15BR L19 0 WW 0 0

45BR L19 5.1 5.1 5.1 5.1

22BR S13 4.4 4.4 4.4 4.4

Each of the solutions is based on assumptions and conditions regarding the aquifer, the wells, and the stress on the aquifer. These assumptions and conditions and their applicability to 

the tests conducted in this study are listed in table 5. 

Water levels in observation wells were recorded for at least 

24 hours prior to each test to determine whether ambient waterlevel trends needed to be considered in the analysis of test data. 

The water level in well 53BR decreased at a rate of about 

0.00026 ft/min during the hour before the pump in well 41BR 

was turned on for the 41BR-53BR aquifer test. Although this 

rate is low, it is large enough to affect test results because total 

measured drawdown during the test was only 0.74 ft. During the 

690-minute test, the decline in water level attributable to ambient conditions was 0.18 ft. Consequently, the observed water 

levels in well 53BR were adjusted by subtracting the ambient 

water-level decline from the drawdown.

The water level in well 56BR decreased at a rate of about 

0.000017 ft/min during the 18-hour period before the pump was 

turned on in well BRP2 for the BRP2-56BR aquifer test. 

Although this rate is low, it is large enough to affect test results 

because total measured drawdown during the pumping phase of 

the test was only 0.60 ft. During the 1,690-minute pumping 

phase, the decline in water level attributable to ambient conditions was 0.029 ft. Consequently, the observed water levels in 

well 56BR were adjusted by subtracting the ambient waterlevel decline from the drawdown.

In the other three observation wells, water levels were stable for at least 1 hour prior to the start of the test. No adjustments were made to the drawdown data from these tests.

Some of the tests were affected by stress to ground-water 

flow caused by infiltration of precipitation after pumping 

began. During the 16BR-41BR aquifer test, precipitation began 

320 minutes after the beginning of the recovery phase; therefore, no data collected after that time were used in the analysis. 

During the 41BR-53BR aquifer test, precipitation began 690 

minutes after pumping began; therefore, no data collected after 

that time were used in the analysis and recovery data could not 

be analyzed. No precipitation occurred during the other three 

tests.

Estimated Values

The transmissivity and storage coefficient obtained from 

applying each analytical solution to each test are listed in table 

6. Transmissivity ranges from 95 to 1,300 ft2/d and storage 

coefficient ranges from 9 x 10-5 to 5 x 10-3. These broad ranges 

are caused by the heterogeneity of the fractured-rock aquifer. 

For most of the tests, however, the transmissivity and storage 

coefficients agreed reasonably well among the three analytical 

solutions. Because all of the aquifer tests were conducted at the 

NAWC, these transmissivity and storage-coefficient values 

cannot be assumed to be representative of the fractured-rock 

aquifer in other areas underlain by the Lockatong Formation. 

Although a value of specific yield can be derived from the Neuman (1974) solution, these specific-yield values are not listed in 

table 6 because the determination of specific yield from this 

solution is considered a dubious procedure (Van der Kamp, 

1985; Kruseman and deRidder, 1990). Values of specific yield 

and other parameters used in or derived from the aquifer-test 

analyses are presented in appendix 1. Plots of observed drawdown and drawdown computed using each of the three solutions 

are shown in figures 4 through 8.

The hydraulic conductivity of the fractured-rock aquifer 

formed by bedding units in the Lockatong Formation at the 

NAWC has been estimated previously from the results of slug 

testing individual wells and by calibration of a digital groundwater-flow model (Lewis-Brown and Rice, 2002). These two 

previous estimates and the estimates made on the basis of the 

small-scale aquifer testing described in this report (table 7)
Hydraulic and Solute-Transport Properties 9

Table 5. Assumptions and conditions inherent in solution methods used to analyze data from aquifer tests, Naval Air Warfare 

Center, West Trenton, New Jersey, 2003.

Assumption/condition (modified 

from Kruseman and deRidder, 

1990) Applicability to aquifer tests described in this report

Assumptions and conditions required for all solution methods used in this study

Aquifer has an infinite areal extent. The hydrogeologic framework described by Lacombe (2000) indicates that this assumption probably is valid over the small area influenced by each test.

Aquifer is homogeneous and isotropic.The hydrogeologic framework described by Lacombe (2000) indicates that this assumption probably is valid over the small area influenced by each test.

Prior to pumping, the piezometric 

surface is horizontal (or nearly so) 

over the area influenced by the test.

This assumption is valid. In the area influenced by each test, the slope of the piezometric 

surface was less than 1 degree prior to pumping.

The aquifer is pumped at a constant 

discharge rate.

In four of the tests (BRP2-20BR, BRP2-56BR, 15BR-BRP3, and 41BR-53BR tests), the 

pumping rate varied by less than 3 percent of the average pumping rate (total gallons 

pumped divided by pumping duration). This is considered a near-constant rate. In one test 

(16BR-41BR test), the average pumping rate was relatively low (1.33 gallons per minute). 

During the first 5 minutes of the test, the pumping rate varied from 0.94 to 3.00 gallons per 

minute. During the remainder of the test, the rate varied from 1.27 to 1.46 gallons per 

minute, a variability of 14 percent. Because the pumping rate was low, it was difficult to 

maintain it at a constant level. Although drawdown data from the later parts of each test 

were weighted more heavily in curve-matching than data from early parts of the tests, the 

14-percent variability in the later-time pumping rate is a concern. Consequently, the level 

of certainty associated with this test is lower than that associated with the other aquifer 

tests.

The withdrawal well penetrates the 

entire thickness of the aquifer.

This assumption probably is met. The reason for this requirement is to minimize the influence of parts of the aquifer that are above or below the well opening. The aquifer consists 

of many thin water-bearing zones alternating with thin confining zones. It is likely that one 

of the thin confining zones is at or near the top and bottom of each well opening and that 

the full-penetration assumption is adequately met.

The diameter of the withdrawal 

well is small so that storage in the 

well can be neglected.

The diameter of the open interval of the withdrawal wells is 6 inches. It is assumed that 

storage in the well can be neglected because of the small well diameter and because drawdown data from the later parts of each test were weighted more heavily in curve-matching 

than data from early parts of the tests, when well storage is more likely to affect drawdown.

Flow to the well is in unsteady 

state; that is, the drawdown differences with time are not negligible, 

nor is the hydraulic gradient constant with time.

This condition was met for all tests.

Additional assumptions and conditions required for the Theis solution method for a confined aquifer

The aquifer is confined. Whether the aquifer was unconfined or confined at each test location is unknown; therefore, solutions for both types of aquifers were attempted for each test.

The aquifer is of uniform thickness 

over the area influenced by the test.

The hydrogeologic framework described by Lacombe (2000) indicates that this assumption probably is valid.

The water removed from storage is 

discharged instantaneously with 

decline of water level.

It is assumed that this condition was met.
10 Hydraulic and Solute-Transport Properties at the Naval Air Warfare Center, West Trenton, New Jersey, 2003

Additional assumptions and conditions required for the Hantush solution method for a wedge-shaped confined aquifer

The aquifer is confined. (See the above explanation of the first condition pertaining to the Theis solution method.)

The water removed from storage is 

discharged instantaneously with 

decline of water level.

It is assumed that this condition was met.

The thickness of the aquifer varies 

exponentially in the direction of 

flow.

The effect of decreasing transmissivity with depth may mimic the effect of decreasing 

thickness with depth. In tests in which the withdrawal well and observation well are open 

to different depths, this assumption is assumed to be valid.

The rate of change in aquifer thickness in the direction of flow does 

not exceed 0.20.

Because the transmissivity, rather than the thickness, of the aquifer decreases, it is not possible to know whether the intended effect of this assumption is met.

Additional assumptions and conditions required for the Neuman solution method for an unconfined aquifer

The aquifer is unconfined. (See the above explanation of the first condition pertaining to the Theis solution method.)

The influence of the unsaturated 

zone on drawdown in the aquifer is 

negligible.

It is assumed that this condition is met.

The ratio of specific yield to earlytime storage coefficient is greater 

than 10.

It is assumed that this condition is met.

The diameter of the observation 

well is small; that is, storage in the 

well can be neglected.

The diameters of the open intervals of the observation wells are 4 to 6 inches. It is 

assumed that storage in the well can be neglected because of the small well diameters and 

because drawdown data from the later parts of each test were weighted more heavily in 

curve-matching than data from early parts of the tests, when well storage is more likely to 

affect drawdown.

Table 5. Assumptions and conditions inherent in solution methods used to analyze data from aquifer tests, Naval Air Warfare 

Center, West Trenton, New Jersey, 2003.

Assumption/condition (modified 

from Kruseman and deRidder, 

1990) Applicability to aquifer tests described in this report

represent conditions at three different scales within the heterogeneous aquifer. Hydraulic-conductivity estimates from slug 

testing represent the conditions in the small area around the 

tested well (probably less than 100 ft2). Hydraulic-conductivity 

estimates from the aquifer testing described in this report represent the conditions in the area of aquifer extending from the area 

around the withdrawal well to the area around the observation 

well (probably less than 1,500 ft2). Hydraulic-conductivity estimates from calibration of the digital model (table 7) represent 

mean conditions over the extent of the NAWC (about 0.15 mi2).

The hydraulic-conductivity values estimated from aquifer 

tests, slug tests, and calibration of the digital model are consistent with each other and reflect the heterogeneous character of 

the aquifer. In the two instances in which the comparison can be 

made, the hydraulic-conductivity values estimated from aquifer 

testing are consistent with the values estimated from slug testing in that the conductivity value obtained from the aquifer test 

at a given pair of wells falls between the conductivity values 

obtained from the slug tests conducted at the two individual 

wells (table 7). 

In many cases, the values of hydraulic conductivity 

derived from aquifer testing and slug testing are higher than the 

values obtained from calibration of the digital model (table 7). 

These higher values represent the hydraulic conductivity in several small areas, whereas the conductivity values used in the 

model represent the net effect of areas of high and low conductivity in the heterogeneous rocks. The aquifer tests all were conducted using recovery wells in the pump-and-treat system, 

which was designed to include wells from which the greatest 

amounts of water could be extracted--that is, wells for which 

slug testing had indicated high hydraulic conductivities. The 

median hydraulic conductivity (estimated from slug-test 

results) in areas near wells used in the aquifer tests is 47 ft/d, 

whereas the mean hydraulic conductivity in areas near all wells 

open to parts of the aquifer formed by rocks of the Lockatong 

Formation at the NAWC (also estimated from slug-test results) 

is 3.2 ft/d (Lewis-Brown and Rice, 2002). Consequently, conductivity values derived from aquifer and slug testing in areas 

near the pump-and-treat recovery wells are expected to be 

higher than those in the model and are consistent with previous 

results.

Table 5. Assumptions and conditions inherent in solution methods used to analyze data from aquifer tests, Naval Air Warfare 

Center, West Trenton, New Jersey, 2003--Continued.
Hydraulic and Solute-Transport Properties 11

Table 6. Transmissivity and storage coefficient estimated from aquifer-test data, Naval Air Warfare Center, West Trenton,

New Jersey, 2003.

[T, transmissivity; S, storage coefficient; all transmissivity values are in units of feet squared per day]

Withdrawal well Observation well

Bedding 

unit1

(Lacombe, 

2000)

Solution method

Well 

name

Depth of open 

interval

(feet below 

land surface)

Well 

name

Depth of open 

interval

(feet below 

land surface)

Theis solution for 

confined aquifers

Hantush solution 

for wedge-shaped 

confined aquifers

Neuman solution 

for unconfined 

aquifers

Top Bottom Top Bottom T S T S T S

BRP2 25 45 20BR 28 43 L17 990 2 x 10-4 790 3 x 10-4 540 2 x 10-4

BRP2 25 45 56BR 140 165 L17 650 6 x 10-4 2170 23 x 10-4 230 3 x 10-4

15BR 26 41 BRP3 25 40 L19 1,300 5 x 10-3 1,300 5 x 10-3 1,300 2 x 10-3

16BR 40 65 41BR 85 110 L19 210 9 x 10-5 2100 21 x 10-4 95 1 x 10-4

41BR 85 110 53BR 95 120 L19 420 4 x 10-3 350 3 x 10-3 240 3 x 10-3

1

All bedding units in which aquifer tests were conducted are in the Lockatong Formation. 2

In tests in which the withdrawal and observation wells are open at substantially different depths, the transmissivity and storage

 coefficients derived from the Hantush solution are assumed to represent the values of these parameters at some point between

 the two wells.

Table 7. Values of hydraulic conductivity estimated from aquifer tests, slug tests, and calibration of a digital model,

Naval Air Warfare Center, West Trenton, New Jersey.

[na, this well was not available for slug testing]

Withdrawal 

well

Observation

well

Geologic 

formation

Mean 

length of 

open 

intervals 

of withdrawal 

well and 

observation well

(feet)

Values from aquifer tests 

described in this report

Values from slug 

testing (Lewis-Brown 

and Rice, 2002)

Values from calibration 

of digital model (LewisBrown and Rice, 2002)

Transmissivity 

(median of 

values 

from three 

solution 

methods) 

(feet 

squared 

per day)

Hydraulic 

conductivity (transmissivity 

divided by 

mean length 

of open 

interval of 

withdrawal 

well and 

observation 

well)

 (feet per 

day)

Hydraulic 

conductivity near 

withdrawal 

well

(feet per 

day) 

Hydraulic 

conductivity near 

observation well 

(feet per 

day)

Hydraulic 

conductivity at 

location of 

withdrawal 

well 

(feet per 

day)1

Hydraulic 

conductivity at 

location of 

observation well 

(feet per 

day)1

BRP2 20BR Lockatong 17.5 790 45 3.3 49 9.4 9.4

BRP2 56BR Locaktong 22.5 230 10 3.3 na 9.4 0.4

15BR BRP3 Lockatong 15 1,300 87 na 140 9.4 9.4

16BR 41BR Lockatong 25 100 4.0 2.4 47 9.4 and 6.9 6.9 and 0.4

41BR 53BR Locaktong 25 350 14 47 na 6.9 and 0.4 6.9 and 0.4

1Hydraulic-conductivity values used in the digital model are depth-dependent. In parts of the aquifer composed of rocks of the Lockatong Formation, a 

hydraulic conductivity of 11.3 feet per day was used for rocks at depths of 26 to 50 feet below land surface; 4.0 feet per day was used for rocks 51 to 100 

feet below land surface; and 0.4 feet per day was used for rocks 101 to 300 feet below land surface.
0.1 1 10 100 1,000 10,000

DRAWDOWN, IN FEET 0.01

0.1

1

Observed

Computed from

Theis solution for

a confined aquifer

TIME, IN MINUTES

0.1 1 10 100 1,000 10,000

DRAWDOWN, IN FEET 0.01

0.1

1

Observed

Computed from

Hantush solution for

a confined, wedgeshaped aquifer

0.1 1 10 100 1,000 10,000

DRAWDOWN, IN FEET 0.01

0.1

1

Observed

Computed from

Neuman solution for

an unconfined aquifer

12 Hydraulic and Solute-Transport Properties at the Naval Air Warfare Center, West Trenton, New Jersey, 2003

Figure 4.Observed drawdown in observation well 20BR during 

pumping of well BRP2, July 1-3, 2003, and drawdown computed 

from three analytical solutions, Naval Air Warfare Center, West 

Trenton, New Jersey.

10 100 1,000 10,000

DRAWDOWN, IN FEET 0.01

0.1

1

Observed

Computed from

Theis solution for

a confined aquifer

TIME, IN MINUTES

10 100 1,000 10,000

DRAWDOWN, IN FEET 0.01

0.1

1

Observed

Computed from

Hantush solution for

a confined, wedgeshaped aquifer

10 100 1,000 10,000

DRAWDOWN, IN FEET 0.01

0.1

1

Observed

Computed from

Neuman solution for

an unconfined aquifer

Figure 5. Observed drawdown in observation well 56BR during 

pumping of well BRP2, July 1-3, 2003, and drawdown computed 

from three analytical solutions, Naval Air Warfare Center, West 

Trenton, New Jersey.
10 100 1,000 10,000

DRAWDOWN, IN FEET 0.01

0.1

1

Observed

Computed from

Theis solution for

a confined aquifer

TIME, IN MINUTES

1 100 1,000 10,000

DRAWDOWN, IN FEET 0.01

0.1

1

Observed

Computed from

Hantush solution for

a confined, wedgeshaped aquifer

10 100 1,000 10,000

DRAWDOWN, IN FEET 0.01

0.1

1

Observed

Computed from

Neuman solution for

an unconfined aquifer

10

1

1

Hydraulic and Solute-Transport Properties 13

Figure 6. Observed drawdown in observation well BRP3 during 

pumping of well 15BR, June 26-30, 2003, and drawdown computed 

from three analytical solutions, Naval Air Warfare Center, West 

Trenton, New Jersey.

10 100 1,000 10,000

DRAWDOWN, IN FEET 0.01

0.1

1

Observed

Computed from

Theis solution for

a confined aquifer

TIME, IN MINUTES

0.1 100 1,000 10,000

DRAWDOWN, IN FEET 0.01

0.1

1

Observed

Computed from

Hantush solution for

a confined, wedgeshaped aquifer

1 100 1,000 10,000

DRAWDOWN, IN FEET 0.01

0.1

1

Observed

Computed from

Neuman solution for

an unconfined aquifer

10

0.1

0.1 10

1

1

Figure 7. Observed drawdown in observation well 41BR during 

pumping of well 16BR, June 11-12, 2003, and drawdown computed 

from three analytical solutions, Naval Air Warfare Center, West 

Trenton, New Jersey.
100 1,000

DRAWDOWN, IN FEET 0.01

0.1

1

Observed

Computed from

Theis solution for

a confined aquifer

TIME, IN MINUTES

10 100 1,000

DRAWDOWN, IN FEET 0.01

0.1

1

Observed

Computed from

Hantush solution for

a confined, wedgeshaped aquifer

100 1,000

DRAWDOWN, IN FEET 0.01

0.1

1

Observed

Computed from

Neuman solution for

an unconfined aquifer

10

10

14 Hydraulic and Solute-Transport Properties at the Naval Air Warfare Center, West Trenton, New Jersey, 2003

Figure 8. Observed drawdown in observation well 53BR during 

pumping of well 41BR, June 17, 2003, and drawdown computed 

from three analytical solutions, Naval Air Warfare Center, West 

Trenton, New Jersey.

Longitudinal Dispersivity and Effective Porosity

Tracer tests can be used to determine solute-transport 

properties (longitudinal dispersivity and effective porosity) of 

an aquifer. Velocity is inversely and linearly related to effective 

porosity; therefore, if the volumetric flux of water is held constant, and the effective porosity is doubled, velocity is halved.

Tracer tests were planned for four pairs of wells at the 

NAWC site. The 41BR/53BR pair was not tested, however, 

because well 53BR overflowed when water was injected, even 

at an extremely low rate (0.3 gal/min).

Field Methods

Doublet tracer tests were conducted at three well pairs. 

This type of tracer test involves creating a stable flow field with 

injection of water into one well and withdrawal of water from a 

second well at the same rate as the injection. The withdrawal 

and injection rate for each tracer test is listed in table 8. After a 

steady-state flow field is established, the tracer is injected as 

nearly instantaneously as possible and water samples are collected from the withdrawal well to monitor the arrival time and 

concentration of the tracer. Doublet tests were conducted rather 

than single-well tests because they take less time, allow more 

control of the tracer flow path and concentration, and allow for 

continuation of the pump-and-treat operation during the tracer 

testing. Bromide was used as the tracer because it is nontoxic, 

conservative (not biodegradable and does not sorb to aquifer 

material), present in very low concentrations (<0.35 mg/L) in 

the native ground water, easy to detect, and inexpensive to measure with an ion-selective electrode.

Before each tracer test was begun, injection of tap water 

was begun at the injection well and withdrawal of water was 

begun at the withdrawal well at a rate equal to the injection rate. 

After the water level in both wells had stabilized, water samples 

were collected from each withdrawal well to obtain background 

bromide concentrations in the water withdrawn from the aquifer 

(0.343, 0.279, and 0.174 mg/L at withdrawal wells BRP2, 

15BR, and 16BR, respectively). The tracer test was then initiated by substituting water containing bromide at a concentration of about 1,000 mg/L for the tap water. The tracer was 

pumped into the injection well at a constant injection rate equal 

to the pumping rate from the withdrawal well (3.5 gal/min, 5.0 

gal/min, and 1.4 gal/min from wells BRP2, 15BR, and 16BR, 

respectively). Injection and withdrawal rates were held constant 

during each test. The injection flow rate was monitored using a 

flow meter near the well head and controlled by means of an inline valve.

During each tracer test, pumps in other recovery wells that 

are part of the pump-and-treat system at the site were either 

turned off or maintained at constant pumping rates for the duration of the test. Pumps in wells that could have interfered with 

flow paths at the test site were turned off; others were kept at a 

constant pumping rate. The pumping rates of all pumped wells 

were monitored during the tracer tests to ensure that they were 

constant. The pumping rate at each recovery well during each 

test is listed in table 9. 
Hydraulic and Solute-Transport Properties 15

Table 8. Rates and duration of pumping at withdrawal wells and injection at injection wells during tracer tests, Naval Air Warfare 

Center, West Trenton, New Jersey, 2003.

Well pair

Bedding unit 

(Lacombe, 2000)

Withdrawal and 

injection rate (gallons 

per minute)

Duration of 

withdrawal and 

Withdrawal well Injection well injection (minutes)

BRP2 20BR L17 3.5 9,000

15BR BRP3 L19 5.0 9,265

16BR 41BR L19 1.4 9,665

Table 9. Pumping rates at recovery wells during tracer tests, Naval Air Warfare Center, West Trenton, New Jersey, 2003.

[Pumping rates listed in this table are for additional wells being pumped during tracer tests to maintain operation of the pumpand-treat system at the Naval Air Warfare Center; WW, well used as withdrawal well during the given tracer test; IW, well used 

as injection well during the given tracer test]

Recovery well

Bedding unit 

(Lacombe, 2000)

Pumping rate (gallons per minute)

BRP2-20BR 

tracer test

15BR-BRP3 tracer 

test

16BR-41BR tracer 

test

BRP2 L17 WW 6.5 6.5

20BR L17 IW 0 8.5

48BR L17 0 13.5 0

56BR L17 0 0 0

15BR L19 0 WW 1.0

45BR L19 0 0 0

22BR S13 4.4 4.4 4.4

Water at the withdrawal wells was sampled at preset time 

intervals using two alternating automatic samplers connected to 

the discharge line by a pipe “T”. Preset time intervals ranged 

from 3 minutes near the beginning of a test to about 24 hours 

during the last days of each test. The samples were transferred 

in the field from the automatic-sampler bottles to polyethylene 

bottles. The automatic-sampler bottles were rinsed with deionized water in the field after they were emptied and before the 

next set of samples was collected. The samples were analyzed 

at the USGS New Jersey Water Science Center laboratory using 

a calibrated bromide-selective electrode.

The mass of bromide injected during each test was determined on the basis of four limiting factors: (1) Sufficient mass 

must be injected to yield measurable concentrations at the withdrawal well. This mass was estimated using the analytical solution of Welty and Gelhar (1994) for a doublet test in isotropic, 

homogeneous porous media. The analytical solution requires 

estimates of the very parameters measured with the tracer tests, 

longitudinal dispersivity and effective porosity. Therefore, values of these parameters determined at a nearby site (Carleton 

and others, 1999) were used for the calculations (effective 

porosity equal to 0.001 and a range of longitudinal-dispersivity 

values from 3 to 66 ft). A detailed description of techniques and 

equations used to estimate the mass required for input and to 

analyze the results is given by Carleton and others (1999). (2) 

Sufficient mass must be injected such that the peak concentration in the withdrawal well is at least 3 mg/L so as to provide 

adequate resolution on a graph of bromide concentration as a 

function of time. (3) The density of the injection solution must 

be low enough to prevent gravity-induced flow from significantly affecting the results; therefore, the concentration of the 

injection fluid was kept below 10 g/L, as suggested by Becker 

and Shapiro (2000). (4) The minimum possible mass that satisfied the above three requirements regarding the mass and concentration of bromide was used to minimize the injection time, 

because the theoretical injection time is instantaneous.

Carleton and others (1999) found that approximately a 

five-fold increase over the mass estimated from the analytical 

solution was required, probably because actual field conditions 

depart from the assumptions in the solution (including homogeneous porous media, no diffusion into the rock matrix, and 

instantaneous input of tracer). On the basis of the analytical 
16 Hydraulic and Solute-Transport Properties at the Naval Air Warfare Center, West Trenton, New Jersey, 2003

solution and the five-fold increase, the appropriate mass of 

injected bromide for the first test, the BRP2-20BR well pair, 

was determined to be 300 g. Because the measured peak bromide concentration during the first test was still lower than 

ideal, the masses for the next two tests were increased to more 

than five times the calculated value. The masses injected for the 

15BR-BRP3 and 16BR-41BR well pairs were 471 and 656 g, 

respectively.

Analysis Methods

The longitudinal dispersivity and effective porosity of the 

tested volumes of the fractured-rock aquifer were estimated 

using the observed bromide-concentration data from each of the 

three tracer tests and the analytical solution described by Welty 

and Gelhar (1994) and Carleton and others (1999). Background 

bromide concentrations (0.343, 0.279, and 0.174 mg/L at withdrawal wells BRP2, 15BR, and 16BR, respectively), as determined by analyzing water samples collected before the bromide 

was injected, were subtracted from the observed concentrations.

Observed data from each test were plotted as dimensionless bromide concentration (measured concentration divided by 

total mass injected) as a function of time and overlaid on multiple plots from the analytical solution. The plots from the analytical solution were generated with all parameters fixed except 

dispersivity. The analytical-solution plot whose rising limb best 

approximated the shape of the rising limb of the plots of 

observed concentration data indicated the estimated dispersivity of the aquifer in the areas around the injection and withdrawal wells. Observed bromide-concentration data and the 

analytical-solution plots for the three tests are shown in figures 

9 through 11. 

Although the match between the observed-data plots and 

the analytical-solution plots was good for the rising limb into 

the peak, the falling limbs were not well matched. In all cases, 

the falling limbs of the analytical-solution plots were substantially below those of the observed-data plots. The falling limbs 

of the observed-data plots probably match those of the analytical-solution plots poorly because the analytical solution is 

based on assumptions that are not strictly valid for the fracturedrock aquifer: that the aquifer is homogeneous and isotropic and 

that the tracer is not retarded by the formation. The processes of 

heterogeneous flow and matrix diffusion, both of which contradict the assumptions and affect solute transport, probably occur 

in the aquifer. For purposes of analyzing the small-scale aquifer 

tests described earlier, however, in which solute-transport properties are not measured, the aquifer can be assumed to be homogeneous and isotropic over the small volumes of aquifer 

affected by those tests. 

It is unknown which process (heterogeneous flow or 

matrix diffusion) is dominant in causing the offset of the 

observed-data plots from the analytical-solution plots. If diffusion of the bromide into and out of dead-end fractures and pores 

in the rock matrix is the dominant process causing the tailing of 

the falling limb, then the dispersivity estimates would produce 

reliable results when used in simulations of advective flow. If 

variable advective transport of the bromide in the heterogeneous fractured rock is the dominant process, as described by 

Becker and Shapiro (2003), the dispersivity estimates are questionable. Because the process causing the departure from the 

homogeneous, isotropic model has not been identified, the dispersivity estimates obtained from the tracer tests conducted in 

this study are questionable and cannot be used reliably in models simulating advective flow.

The effective porosity of the aquifer was estimated from 

the observed bromide-concentration data by solving the equation from Welty and Gelhar (1994): 

n = Qt

 tdHL2

where n is effective porosity,

Q is equal pumping and injection rates [L3t

-1],

t is time (obtained by finding the time on the observeddata plot corresponding to the dimensionless time 

chosen from the analytical-solution plot),

td is dimensionless time (obtained by choosing a dimensionless time on the analytical-solution plot),

H is aquifer thickness (assumed to be the length of the 

open interval of the withdrawal well) [L], and

L is the distance between the wells [L].

The effective-porosity estimates obtained from the tracer 

tests conducted in this study are considered to be more reliable 

than the dispersivity estimates. Effective porosity is determined 

from the time of arrival of peak bromide concentration, which 

is not affected substantially by diffusion into the rock matrix or 

the variable advective transport of the bromide in the heterogeneous fractured rocks.

Estimated Values

The estimates of longitudinal dispersivity and effective 

porosity obtained from analysis of the data from the three tracer 

tests conducted at the NAWC are presented in table 10. Because 

all three tests were conducted at the NAWC, they cannot be 

assumed to be representative of the fractured-rock aquifer in 

other areas underlain by the Lockatong Formation.

The tracer-test data indicate that both the longitudinal dispersivity and the effective porosity of shallow rocks (less than 

about 45 ft below land surface) are greater than those of deeper 

rocks. The estimated longitudinal dispersivities of the shallow 

and deep rocks are 7 and 4 ft, respectively; the estimated porosities of the shallow and deep rocks are 0.002 and 0.0003, respectively (table 10). The shallow rocks are more porous than the 

deeper rocks, probably because the degree of weathering and 

fracturing is greater in the shallow rocks.
TIME SINCE INJECTION OF TRACER BEGAN, IN MINUTES

100 1,000 10,000

BROMIDE CONCENTRATION, IN MILLIGRAMS 

PER LITER, DIVIDED BY MASS INJECTED, 

IN KILOGRAMS 

0.01

0.1

1

10

Observed

Computed from analytical solution

Hydraulic and Solute-Transport Properties 17

Figure 9. Observed bromide concentration in withdrawal well BRP2 resulting from injection of bromide tracer at well 20BR at the Naval 

Air Warfare Center, West Trenton, New Jersey, and the dimensionless concentration computed from the analytical solution of Welty and 

Gelhar (1994) for a doublet tracer test with longitudinal dispersivity (αL) divided by distance between wells (L) of 0.07.

  	 
 
 
  

  


 

  


    
 	

 












 

!"#$% &!" '(')*%+,') !)$%+!(

Figure 10. Observed bromide concentration in withdrawal well 15BR resulting from injection of bromide tracer at well BRP3 at the Naval 

Air Warfare Center, West Trenton, New Jersey, and the dimensionless concentration computed from the analytical solution of Welty and 

Gelhar (1994) for a doublet tracer test with longitudinal dispersivity (αL) divided by distance between wells (L) of 0.07.
TIME SINCE INJECTION OF TRACER BEGAN, IN MINUTES

100 1,000 10,000

BROMIDE CONCENTRATION, IN MILLIGRAMS 

PER LITER, DIVIDED BY MASS INJECTED, 

IN KILOGRAMS

0.1

1

10

100

Observed

Computed from analytical solution

18 Hydraulic and Solute-Transport Properties at the Naval Air Warfare Center, West Trenton, New Jersey, 2003

Figure 11. Observed bromide concentration in withdrawal well 16BR resulting from injection of bromide tracer at well 41BR at the Naval 

Air Warfare Center, West Trenton, New Jersey, and the dimensionless concentration computed from the analytical solution of Welty and 

Gelhar (1994) for a doublet tracer test with longitudinal dispersivity (αL) divided by distance between wells (L) of 0.04.

Table 10. Longitudinal dispersivity and effective porosity estimated from tracer-test data, Naval Air Warfare Center, West Trenton, 

New Jersey, 2003.

Injection well 

Withdrawal 

well 

Bedding unit 1 

(Lacombe, 

2000)

Depth of open interval of well 

(feet below land surface) Longitudinal 

dispersivity2

(feet)

Effective 

Injection well porosity

Withdrawal 

well 

20BR BRP2 L17 28 - 43 25 - 45 7 .002

BRP3 15BR L19 25 - 40 26 - 41 7 .002

41BR 16BR L19 85 - 110 40 - 65 4 .0003

1 All bedding units in which tracer tests were conducted are in the Lockatong Formation. 2 These longitudinal dispersivity values are questionable because some assumptions in the model used to determine the values are not met in 

this aquifer.

Simulated Advective Transport of 

Contaminated Ground Water

Ground-water flow at the NAWC under conditions in 

which no wells are pumped at the NAWC and in two different 

pumping scenarios was simulated using an existing model of 

steady-state ground-water flow at the site (Lewis-Brown and 

Rice, 2002). The modeled area extends beyond the NAWC to 

include streams to which ground water from the NAWC may 

flow (fig. 1). The model grid is variably spaced, with small (25- 

to 50-ft-wide) cells in the area representing the NAWC and 

larger cells near the model borders (fig. 12). The MODFLOW 

code (Harbaugh and others, 2000) was used for the simulation. 

Travel time, velocity, and discharge points of contaminated 

ground water were computed using the particle-tracking postprocessor MODPATH (Pollock, 1994) and the effective-porosity values determined in this study.
ST2

ST1

ST3

DELAWARE RIVER

Stream cell

Fault cell at land surface

Inactive model cell (all layers)

Stream or river

Canal

Road

NAWC property boundary

No-flow boundary

Unnamed stream 1

Unnamed stream 2

Unnamed stream 3

EXPLANATION 0 1,000 2,000 3,000 4,000 FEET

0 1,000 METERS

WEST BRANCH

SHABAKUNK CREEK

GOLD RUN

REEDERS CREEK

ST1

ST2

ST3

150

140

130

120

110

100

90

8070605040

30

20

10

ROW NUMBER

10

20

30

40

50

60

70

80

90

100

110

120

130

140

150

160

COLUMN NUMBER

40

15'

00"

40

16'

00"

74 50'00"

74 

47'

00"

74 51'00" 40 17'00" 74 49'00" 74 48'00"

Simulated Advective Transport of Contaminated Ground Water 19

Figure 12. Finite-difference grid for the ground-water-flow model, Naval Air Warfare Center, West Trenton, New Jersey, and vicinity.
20 Hydraulic and Solute-Transport Properties at the Naval Air Warfare Center, West Trenton, New Jersey, 2003

Travel Time and Velocity under Ambient Conditions

Travel time and velocity of contaminated ground water 

under ambient conditions (with no wells being pumped at the 

NAWC) were estimated by computing ground-water flow paths 

from each contaminated well to the stream where the water exits 

the ground-water system. Only advective flow is simulated with 

the model; the effects of density, dispersion, diffusion, dilution, 

and degradation of contaminants are not simulated. Therefore, 

it is not possible to determine with the model whether water 

from each contaminated well remains contaminated along its 

entire flow path. One particle was placed in the center of each 

model cell containing a contaminated well. Most (40) of the 58 

model cells containing contaminated wells are 25 x 25 ft in area; 

17 are 25 x 50 ft; and 1 is 50 x 50 ft. One point at the center of 

these small cells was considered to be an adequate representation of the volume of water at and near the well location. For 

purposes of this report, a well is contaminated if any sample collected from the well contained TCE, DCE, or VC in concentrations greater than the New Jersey maximum contaminant level 

(1, 70, and 2 μg/L, respectively (N.J. Department of Environmental Protection, 2002)). Construction and location data for 

contaminated wells and wells used in aquifer and tracer tests are 

listed in table 11. The travel time, velocity, and discharge point 

of each flow path are listed in table 12. The receiving stream for 

the flow path from each contaminated well is illustrated in figure 13.

The value of the effective porosity of the aquifer is a necessary component of the computation of travel time and velocity. In this study, the effective porosity was determined in three 

discrete parts of the aquifer. To rigorously determine travel 

times throughout the heterogeneous aquifer at the NAWC, it 

would be necessary to determine the effective porosity throughout the site by conducting at least two tracer tests in each of the 

16 bedding units at the NAWC. Because conducting that many 

tests was beyond the scope of this phase of the investigation, 

tests were conducted in the areas of greatest concern, which 

were the two bedding units in which the highest levels of contamination have been detected. For purposes of estimating 

travel time using the MODPATH particle tracker, the effective 

porosity of the aquifer was assumed to be 0.002 in rocks less 

than 45 ft below land surface and 0.0003 in deeper rocks, on the 

basis of the findings listed in table 10, with a margin of uncertainty of about one order of magnitude. The estimates of travel 

time and velocity presented in table 12 include this margin of 

uncertainty.

If values of effective porosity are assumed to be low, the 

travel time of contaminated ground water from a contaminated 

well to the receiving stream is shorter than if values of effective 

porosity are assumed to be high (table 12). Shorter travel times 

would result in a worst-case scenario for non-pumping remediation methods because less time would be available for processes such as dispersion, dilution, and degradation of contaminants to occur before the contaminated water reaches the 

stream. Short travel times would result in a best-case scenario, 

however, for the pump-and-treat remediation method currently 

being used at the NAWC, because the overall time required for 

clean-up would be shorter. Estimates of travel time computed 

from the ground-water-flow model, however, do not include the 

effects of density, dispersion, dilution, degradation, and, perhaps most importantly, diffusion of contaminants into and out 

of dead-end fractures in the rock matrix, a factor that may be at 

least as important as the velocity of the water in determining the 

effectiveness of remediation techniques.

Table 11. Well-construction and location data for selected wells at the Naval Air Warfare Center, West Trenton,

New Jersey.

[USGS, U.S. Geological Survey; WZ, weathered zone; --, not determined; latitude and longitude, in degrees, minutes, and seconds, are 

referenced to the North American Datum of 1983; altitude is referenced to the North American Vertical Datum of 1988]

Well 

name

USGS 

well 

number

New Jersey 

permit 

number Latitude Longitude

Altitude 

of land 

surface 

(feet)

Depth of open interval 

(feet below land 

surface)

Bedding 

unit 

(Lacombe, 

2000)

Geologic 

Top Bottom formation

2S 210493 27-09895-8 401607 744848 148.83 3 8 WZ Lockatong

6S 210495 27-09893-1 401604 744846 146.89 4 10 WZ Stockton

11S 210496 27-09888-5 401612 744834 158.83 8 23 WZ Lockatong

12S 210497 27-09889-3 401612 744832 157.83 10.5 20.5 WZ Lockatong

13S 210498 27-09890-7 401613 744831 158.36 10 20 WZ Lockatong

14S 210499 27-09891-5 401614 744830 162.90 14.5 24.5 WZ Lockatong

15S 210500 27-09918-1 401608 744847 148.73 3 13 WZ Lockatong

24S 210507 27-09927-0 401615 744849 168.39 5.5 15.5 WZ Lockatong

25S 210508 27-09925-3 401614 744848 167.81 3.5 18.5 WZ Lockatong

28S 210511 27-10962 401611 744833 156.31 10 25 WZ Lockatong

31S 210601 27-10963 401609.45 744834.97 149.73 10 20 WZ Lockatong

37S 210528 27-12681 401605 744836 147.35 6 16 WZ Stockton

39S 210529 27-12683 401605 744845 149.06 3 13 WZ Stockton

41S 210531 27-12685 401606 744849 149.49 3 13 WZ Lockatong

11MW1 210570 27-14458 401607.28 744834.37 152.16 8 22 WZ Stockton
Simulated Advective Transport of Contaminated Ground Water 21

12MW1 210580 27-15414 401608.99 744833.24 155.53 5 15 WZ Stockton

35MW1 210572 27-14459 401616.28 744847.56 168.92 7 25 WZ Lockatong

BRP1 210537 27-09937-7 401609 744844 149.73 20 60 L20 Lockatong

BRP2 210422 27-12419 401605 744849 149.37 25 45 L17 Lockatong

BRP3 210423 27-12420 401607 744850 149.53 25 40 L19 Lockatong

2BR 210545 27-10961-5 401612 744833 157.24 40 60 L20 Lockatong

4BR 210530 27-11938 401606 744844 149.97 24 39 L17 Lockatong

5BR 210424 27-11939 401605 744848 148.84 69 84 L15 Lockatong

7BR 210514 27-11941 401606 744847 148.65 38 53 L18 Lockatong

8BR 210515 27-11942 401610 744848 150.98 32 57 L22 Lockatong

9BR 210516 27-11948 401612 744848 152.13 19 44 L23 Lockatong

11BR 210427 27-11950 401614 744830 163.61 55 75 L21 Lockatong

12BR 210517 27-11951 401614 744833 161.78 56.5 71.5 L22 Lockatong

15BR 210520 27-11943 401607 744849 148.73 26 41 L19 Lockatong

16BR 210521 27-11954 401609 744842 149.42 40 65 L19 Lockatong

17BR 210522 27-11944 401608 744843 149.64 19 44 L19 Lockatong

20BR 210525 27-11945 401605 744850 149.77 28 43 L17 Lockatong

21BR 210526 27-11957 401614 744849 167.94 50 65 L23 Lockatong

22BR 210527 27-11946 401604 744844 147.37 24 49 S13 Stockton

23BR 210428 27-11947 401606 744844 149.90 65 90 L16 Lockatong

24BR 210429 27-12408 401606 744847 149.18 80 95 L16 Lockatong

25BR 210430 27-12409 401607 744849 148.61 75 100 L18 Lockatong

27BR 210432 27-12412 401604 744846 146.91 65 80 L13 Lockatong

29BR 210417 27-12427 401609 744848 149.81 85 100 L21 Lockatong

30BR 210434 27-12428 401608 744844 149.41 85 110 L18 Lockatong

31BR 210435 27-12429 401609 744835 150.66 35 45 L15 Lockatong

36BR 210440 27-12417 401608 744850 154.34 102 125 L19 Lockatong

37BR 210441 27-12418 401605 744833 142.76 60 75 S11 Stockton

38BR 210442 27-12411 401609 744845 149.61 100 115 L19 Lockatong

40BR 210533 27-13977 401606 744852 153.05 95 120 L18 Lockatong

41BR 210541 27-13978 401610 744842 149.30 85 110 L19 Lockatong

45BR 210542 27-13982 401610 744850 158.51 185 210 L19 Lockatong

46BR 210543 27-13983 401611 744846 149.73 196 221 L19 Lockatong

47BR 210538 27-14146 401609 744844 149.85 3 18 WZ Lockatong

48BR 210540 27-14149 401610 744835 159.84 82 100 L17 Lockatong

49BR 210536 27-14148 401609 744838 149.16 42 60 L17 Lockatong

50BR 210544 27-14147 401612 744829 157.28 60 80 L17 Lockatong

51BR 210548 27-14150 401613 744832 158.48 86 96 L20 Lockatong

53BR 210581 27-15279 401610.31 744839.55 147.43 95 120 L19 Lockatong

54BR 210575 27-15278 401608.13 744834.46 152.95 175 200 -- Lockatong

56BR 210579 27-15276 401608.05 744848.52 149.37 140 165 L17 Lockatong

60BR 210624 27-16879 401606.56 744851.19 153.39 70 85 L19 Lockatong

61BR 210627 27-16880 401609.24 744849.89 156.96 70 100 L19 Lockatong

65BR 210622 27-16883 401605.04 744844.45 149.36 15 40 L14 Lockatong

Table 11. Well-construction and location data for selected wells at the Naval Air Warfare Center, West Trenton,

New Jersey.

[USGS, U.S. Geological Survey; WZ, weathered zone; --, not determined; latitude and longitude, in degrees, minutes, and seconds, are 

referenced to the North American Datum of 1983; altitude is referenced to the North American Vertical Datum of 1988]

Well 

name

USGS 

well 

number

New Jersey 

permit 

number Latitude Longitude

Altitude 

of land 

surface 

(feet)

Depth of open interval 

(feet below land 

surface)

Bedding 

unit 

(Lacombe, 

2000)

Geologic 

Top Bottom formation

Table 11. Well-construction and location data for selected wells at the Naval Air Warfare Center, West Trenton,

New Jersey--Continued.
Table 12. Travel time and average linear velocity of flow paths from contaminated wells at the Naval Air Warfare Center, West Trenton, New Jconditions. [ WZ, weathered zone; L, Lockatong Formation; S, Stockton Formation; --, not determined] Well name Depth of open interval (feet below land surface) Bedding unit (Lacombe, 2000) Geologic formation Stream to which water discharges from the ground- water system Length of flow path from well to stream (feet) Travel time and average linear velo

 Assuming porosity equal to tracer-test results (0.002 in rocks less than 45 feet below land surface and 0.0003 in deeper rocks) Incorporating a ma

porosity values ob

r

Assuming porosity lower than tracer-te

results (0.0006 in rock

less than 45 feet belo

land surface and 0.0001 in deeper rocks

Top Bottom Travel time (days) Average linear velocity (feet per day) Travel time (days) Averag

linear velocity (feet pe

day) 

2S 3 8 WZ

L Gold Run (west branch) 263 16 16 4.8 55 

6S 4 10 WZ S Gold Run (west branch) 37.7 470 .080 140 .27 11S 8 23 WZ

L Delaware River 12,000 220 55 71 170 

12S 10.5 20.5 WZ

L Gold Run (west branch) 2,270 280 8.0 93 24 

13S 10 20 WZ

L Gold Run (main stem) 3,660 980 3.8 320 11 

14S 14.5 24.5 WZ

L West Branch Shabakunk Creek 3,840 390 10 130 30 

15S 3 13 WZ

L Gold Run (west branch) 480 41 12 12 40 

24S 5.5 15.5 WZ

L Reeders Creek 5,210 54 96 17 310 

25S 3.5 18.5 WZ

L Reeders Creek 5,400 65 83 20 270 

28S 10 25 WZ

L Gold Run (west branch) 1,430 260 5.6 81 18 

31S 10 20 WZ

L Gold Run (west branch) 839 1,600 .54 470 1.8 

37S 6 16 WZ S Gold Run (west branch) 363 35 11 10 35 39S 3 13 WZ S Gold Run (west branch) 175 460 .38 140 1.3 41S 3 13 WZ

L Gold Run (west branch) 149 5.7 26 1.7 87 

11MW1 8 22 WZ S Gold Run (west branch) 611 57 1 17 35 12MW1 5 15 WZ S Gold Run (west branch) 906 93 9.7 28 32 35MW1 7 25 WZ

L Reeders Creek 5,230 78 66 24 220 

BRP1 20 60 L20

L Gold Run (west branch) 725 18 40 5.4 130 

BRP2 25 45 L17

L Gold Run (west branch) 108 2.5 44 .74 150 

BRP3 25 40 L19

L Gold Run (west branch) 300 6.0 50 1.8 170 
2BR 40 60 L20 L Delaware River 12,300 700 18 230 53 4BR 24 39 L17 L Gold Run (west branch) 419 12 34 3.7 110 5BR 69 84 L15 L Gold Run (west branch) 130 1.8 71 .57 230 7BR 38 53 L18 L Gold Run (west branch) 382 7.4 52 2.2 170 8BR 32 57 L22 L Gold Run (west branch) 735 12 63 3.6 200 9BR 19 44 L23 L Reeders Creek 7,630 59 130 19 410 11BR 55 75 L21 L West Branch Shabakunk Creek 3,850 410 9.4 140 28 12BR 56.5 71.5 L22 L Delaware River 12,200 260 47 87 140 15BR 26 41 L19 L Gold Run (west branch) 319 8.6 37 2.6 120 16BR 40 65 L19 L Gold Run (west branch) 823 10 82 3.1 260 17BR 19 44 L19 L Gold Run (west branch) 658 18 37 5.4 120 20BR 28 43 L17 L Gold Run (west branch) 61.6 1.4 43 .43 140 21BR 50 65 L23 L Reeders Creek 5,570 101 55 34 170 22BR 24 49 S13 S Gold Run (west branch) 45.3 27 1.7 8.1 5.6 23BR 65 90 L16 L Gold Run (west branch) 455 6.2 73 1.9 230 24BR 80 95 L16 L Gold Run (west branch) 406 3.2 130 1.0 400 25BR 75 100 L18 L Gold Run (west branch) 389 3.9 100 1.2 320 27BR 65 80 L13 L Gold Run (west branch) 122 130 .91 44 2.8 29BR 85 100 L21 L Gold Run (west branch) 753 8.0 95 2.5 300 30BR 85 110 L18 L Gold Run (west branch) 660 15 43 4.6 140 31BR 35 45 L15 L Gold Run (west branch) 2,060 320 6.5 100 20 36BR 102 125 L19 L Gold Run (west branch) 541 7.5 70 2.3 230 37BR 60 75 S11 S Gold Run (west branch) 391 52 75 16 25 38BR 100 115 L19 L Gold Run (west branch) 882 8.4 100 2.7 330 40BR 95 120 L18 L Gold Run (west branch) 262 4.3 61 1.3 200 

Table 12. Travel time and average linear velocity of flow paths from contaminated wells at the Naval Air Warfare Center, West Trenton, New Jconditions.[ WZ, weathered zone; L, Lockatong Formation; S, Stockton Formation; --, not determined]

Well 

name

Depth of open 

interval (feet below 

land surface)

Bedding 

unit 

(Lacombe, 

2000)

Geologic 

formation

Stream to which water 

discharges from the groundwater system

Length of 

flow path 

from well 

to stream 

(feet)

Travel time and average linear velo

 Assuming porosity 

equal to tracer-test 

results (0.002 in rocks 

less than 45 feet below 

land surface and 

0.0003 in deeper rocks)

Incorporating a ma

porosity values ob

r

Assuming porosity 

lower than tracer-te

results (0.0006 in rock

less than 45 feet belo

land surface and 

0.0001 in deeper rocks

Top Bottom

Travel 

time 

(days)

 Average 

linear 

velocity 

(feet per 

day)

Travel 

time 

(days)

 Averag

linear 

velocity 

(feet pe

day)

Table 12. Travel time and average linear velocity of flow paths from contaminated wells at the Naval Air Warfare Center, West Trenton, New J

conditions--Continued.
41BR 85 110 L19 L Gold Run (west branch) 951 9.1 100 2.9 320 45BR 185 210 L19 L Delaware River 10,600 460 23 150 71 46BR 196 221 L19 L Delaware River 11,000 510 21 170 64 47BR 3 18 WZ L Gold Run (west branch) 675 34 20 10 66 48BR 82 100 L17 L Gold Run (west branch) 1,050 440 2.3 130 7.9 49BR 42 60 L17 L Delaware River 11,300 210 55 68 170 50BR 60 80 L17 L West Branch Shabakunk Creek 4,310 1,300 3.5 430 10 51BR 86 96 L20 L Gold Run (main stem) 6,920 2,300 2.1 770 9.0 54BR 175 200 -- L Gold Run (west branch) 2,450 260 11 83 30 56BR 140 165 L17 L Reeders Creek 7,300 96 79 30 240 60BR 70 85 L19 L Gold Run ( west branch) 192 4.2 46 1.3 150 61BR 70 100 L19 L Delaware River 10,500 120 73 41 260 65BR 15 40 L14 L Gold Run (west branch) 115 100 1.1 31 3.8 

Table 12. Travel time and average linear velocity of flow paths from contaminated wells at the Naval Air Warfare Center, West Trenton, New Jconditions. [ WZ, weathered zone; L, Lockatong Formation; S, Stockton Formation; --, not determined] Well name Depth of open interval (feet below land surface) Bedding unit (Lacombe, 2000) Geologic formation Stream to which water discharges from the ground- water system Length of flow path from well to stream (feet) Travel time and average linear velo

 Assuming porosity equal to tracer-test results (0.002 in rocks less than 45 feet below land surface and 0.0003 in deeper rocks) Incorporating a ma

porosity values ob

r

Assuming porosity lower than tracer-te

results (0.0006 in rock

less than 45 feet belo

land surface and 0.0001 in deeper rocks

Top Bottom Travel time (days) Average linear velocity (feet per day) Travel time (days) Averag

linear velocity (feet pe

day) 

Table 12. Travel time and average linear velocity of flow paths from contaminated wells at the Naval Air Warfare Center, West Trenton, New J

conditions--Continued.
Fault zone - shows the fault contact at an altitude

of 150 feet above NAVD 88 (approximate land surface)

EXPLANATION

BUILDING 40

BUILDING 41

BUILDING 42

BUILDING 21

BUILDING 22

0 100 200 300 FEET

0 50 METERS

36BR

45BR

9BR

12BR 51BR

2BR

48BR

49BR

38BR

20BR

15BR

40BR

BRP1

30BR 47BR

25S

11S

21BR

41S

2S

Fence--approximate boundary of

Naval Air Warfare Center property

11BR

11S

31BR

12S

25S

50BR

60BR

Contaminated well and identifier; simulated flow at and near this site discharges to:

Reeders Creek

Gold Run (west branch)

Gold Run (main stem)

Delaware River

West Branch of Shabakunk Creek

11BR

31BR

41BR

16BR

23BR

4BR

17BR

8BR

46BR

27BR 29BR

65BR

24BR

5BR

BRP2

7BR

56BR

BRP3

25BR

Extent of model grid

12S

14S

13S

6S

31S

37S

39S

28S

11MW1

15S

12MW1

37BR 54BR

61BR

35MW1

24S 22BR

Approximate distance to 

Reeders Creek 4,000 feet

Approximate distance to 

Delaware River 9,000 feet

Approximate distance to

Gold Run (main stem) 4,500 feet

Swamp

Building

Approximate distance to 

West Branch 

Shabakunk Creek 3,000 feet

I- 95

NAWC

40

15'

00"

40

16'

00"

74 51'00" 74 49'00" 74 47'00"

40

17'

00"

DELAWARE AND RARITAN CANAL

GOLD RUN

DELAWARE RIVER

REEDERS CREE

ST1

ST2

K

WEST BRANCH SHABAKUNK

0 4,000 FEET

0 1,000 METERS

ST3

Map location

CREEK

74 48'30"

74 48'45"

40 16'00" 40 16'15"

Gold Run (west branch)

Simulated Advective Transport of Contaminated Ground Water 25

Figure 13. Simulated discharge locations of ground water at and near contaminated wells at the Naval Air Warfare Center, West Trenton, 

New Jersey (with no recovery wells pumped).
26 Hydraulic and Solute-Transport Properties at the Naval Air Warfare Center, West Trenton, New Jersey, 2003

The wide range of velocities listed in table 12 (0.080 to 130 

ft/d if porosities of 0.002 and 0.0003 in the shallow and deep 

rocks, respectively, are used to calculate velocities) is a result of 

the heterogeneity of the aquifer. Hydraulic conductivity in the 

aquifer varies widely between the Lockatong and Stockton Formations, between faulted and nonfaulted rocks, and with depth 

(Lewis-Brown and Rice, 2002). Overall, the horizontal hydraulic conductivity used in the model varies from 0.001 to 11.3

ft/d, and the vertical hydraulic conductivity varies from 0.0001 

to 1.13 ft/d (Lewis-Brown and Rice, 2002).

Discharge Points during Operation of Pump-and-Treat 

System

The effect on ground-water flow of a recent (July 2004) 

change to the configuration of recovery wells in the pump-andtreat system at the NAWC was evaluated using the existing 

ground-water-flow model. The wells pumped in the former and 

current networks (networks II and III) are listed in table 13.

Network II was changed to network III by adding well 

56BR with a pumpage rate of 5 gal/min, and decreasing pumpage from well 15BR by the same amount. Well 56BR is near 

well 15BR but is deeper. The change was made to increase the 

amount of water pumped directly from the deeper, more contaminated part of the aquifer. Simulation results indicate that the 

change caused water in the areas of three deep wells (25BR, 

38BR, and 56BR) to be captured by well 56BR instead of flowing upward to well 15BR. The simulated discharge point of 

ground water at and near each contaminated well when each of 

these networks is operating is shown in figure 14 and listed in 

table 14.

Simulation results also indicate that the change from 

recovery-well network II to network III resulted in the additional, unexpected effect that water in the vicinity of well 49BR 

is captured by well 22BR instead of well BRP2. In the area near 

well 49BR, the model apparently is very sensitive to changes in 

the pumpage scheme. Consequently, it is uncertain which 

recovery well captures flow from this area, although it is nearly 

certain that the flow is captured by one of the wells. 

Suggestions for Additional Work

To determine more definitively the effectiveness of various configurations of recovery wells in the pump-and-treat system, it would be helpful to compute and illustrate the system’s 

capture area in each bedding unit. To compute the capture areas 

accurately, the current ground-water-flow model could be 

refined to represent the distribution of hydraulic conductivity at 

the site with greater precision. The hydraulic conductivity of 

wells determined from slug testing (Lewis-Brown and Rice, 

2002) could be used as a starting point in defining the distribution of conductivity; wells that have been installed since that 

testing and wells not available at that time also could be slug 

tested to obtain additional data points needed to improve the 

current understanding of the distribution of hydraulic conductivity. 

A solute-transport model could be developed and used to 

obtain information about the transport and fate of contaminants 

under both pump-and-treat and non-pumping remediation 

methods. The model could be used to compute the decrease in 

contaminant concentrations resulting from dispersion, dilution, 

degradation, and diffusion along flow paths originating at the 

NAWC. Additional tracer tests aimed at defining more rigorously the distribution of effective porosity and longitudinal dispersivity at the NAWC would be helpful in developing the solute-transport model.

Table 13. Recovery wells in pump-and-treat system, Naval Air Warfare Center, West Trenton, New Jersey.

Recovery well 

Bedding unit 

(Lacombe, 2000)

Depth of well opening 

(feet below land 

surface)

Pumping rate (gallons per minute)

Network II Network III

BRP2 L17 25 - 45 10.0 10.0

15BR L19 26 - 41 15.0 10.0

20BR L17 28 - 43 8.5 8.5

22BR S13 24 - 49 4.4 4.4

45BR L19 185 - 210 5.1 5.1

48BR L17 82 - 100 13.5 13.5

56BR L17 140 - 165 0 5.0
Fault zone - shows the fault contact at an altitude

of 150 feet above NAVD 88 (approximate land surface)

EXPLANATION

BUILDING 40

BUILDING 41

BUILDING 42

BUILDING 21

BUILDING 22

BARO

WELL

0 100 200 300 FEET

0 50 METERS

36BR

45BR

9BR

12BR 51BR

2BR

48BR

49BR

38BR

20BR

15BR

60BR

23BR

4BR

BRP1

47BR 30BR

25S

11S

21BR

41S

2S

Fence--approximate boundary of

Naval Air Warfare Center property

11BR

Recovery well and identifier

Contaminated well and identifier; simulated flow at and near this site discharges to:

Gold Run (west branch)

Recovery well

40BR

61BR

11BR

31BR

41BR

16BR

17BR

46BR

27BR

65BR

7BR

24BR

5BR

BRP2 BRP3

8BR

29BR

25BR

12MW1

22BR

Extent of model grid

54BR

50BR

37BR

12S

14S

13S

6S

31S

37S

39S 24S

28S

11MW1

35MW1

15S

12MW1

22BR

56BR

74 48'30"

74 48'45"

40 16'00" 40 16'15"

I- 95

NAWC

40

15'

00"

40

16'

00"

74 51'00" 74 49'00" 74 47'00"

40

17'

00"

DELAWARE AND RARITAN CANAL

GOLD RUN

DELAWARE RIVER

REEDERS CREE

ST1

ST2

K

WEST BRANCH SHABAKUNK

0 4,000 FEET

0 1,000 METERS

ST3

Map location

CREEK

Swamp

Building

Gold Run (west branch) 

Suggestions for Additional Work 27

Figure 14. Simulated discharge locations of ground water at and near contaminated wells at the Naval Air Warfare Center, West Trenton, 

New Jersey (with recovery-well network II or III in operation).
28 Hydraulic and Solute-Transport Properties at the Naval Air Warfare Center, West Trenton, New Jersey, 2003

Table 14. Simulated discharge points of ground-water flow paths from contaminated wells at the Naval Air Warfare Center, 

West Trenton, New Jersey, during operation of pump-and-treat system.

[WZ, weathered zone; gal/min, gallons per minute; --, not determined]

Well name

(flow path 

starting point)

Bedding unit 

(Lacombe, 2000)

Geologic 

formation Recovery-well network II1 Recovery-well network III2

2S WZ Lockatong Well 15BR Well 15BR

6S WZ Stockton Well 22BR Well 22BR

11S WZ Lockatong Well 48BR Well 48BR

12S WZ Lockatong Well 48BR Well 48BR

13S WZ Lockatong Well 48BR Well 48BR

14S WZ Lockatong Well 48BR Well 48BR

15S WZ Lockatong Well 15BR Well 15BR

24S WZ Lockatong Well 15BR Well 15BR

25S WZ Lockatong Well 15BR Well 15BR

28S WZ Lockatong Well 48BR Well 48BR

31S WZ Lockatong Well 48BR Well 48BR

37S WZ Stockton Gold Run (west branch) Gold Run (west branch)

39S WZ Stockton Well 22BR Well 22BR

41S WZ Lockatong Well BRP2 Well BRP2

11MW1 WZ Stockton Gold Run (west branch) Gold Run (west branch)

12MW1 WZ Stockton Gold Run (west branch) Gold Run (west branch)

35MW1 WZ Lockatong Well 15BR Well 15BR

BRP1 L20 Lockatong Well 15BR Well 15BR

BRP2 L17 Lockatong Well BRP2 Well BRP2

BRP3 L19 Lockatong Well 15BR Well 15BR

2BR L20 Lockatong Well 48BR Well 48BR

4BR L17 Lockatong Well BRP2 Well BRP2

5BR L15 Lockatong Well BRP2 Well BRP2

7BR L18 Lockatong Well 15BR Well 15BR

8BR L22 Lockatong Well 15BR Well 15BR

9BR L23 Lockatong Well 15BR Well 15BR

11BR L21 Lockatong Well 48BR Well 48BR

12BR L22 Lockatong Well 48BR Well 48BR

15BR L19 Lockatong Well 15BR Well 15BR

16BR L19 Lockatong Well BRP2 Well BRP2

17BR L19 Lockatong Well BRP2 Well BRP2

20BR L17 Lockatong Well 20BR Well 20BR

21BR L23 Lockatong Well 45BR Well 45BR

22BR S13 Stockton Well 22BR Well 22BR

23BR L16 Lockatong Well BRP2 Well BRP2

24BR L16 Lockatong Well BRP2 Well BRP2

25BR L18 Lockatong Well 15BR Well 56BR

27BR L13 Lockatong Well 22BR Well 22BR

29BR L21 Lockatong Well 15BR Well 15BR

30BR L18 Lockatong Well BRP2 Well BRP2

31BR L15 Lockatong Well 48BR Well 48BR

36BR L19 Lockatong Well 15BR Well 15BR

37BR S11 Stockton Gold Run (west branch) Gold Run (west branch)

38BR L19 Lockatong Well 15BR Well 56BR

40BR L18 Lockatong Well 20BR Well 20BR

41BR L19 Lockatong Well BRP2 Well BRP2

45BR L19 Lockatong Well 45BR Well 45BR

46BR L19 Lockatong Well 45BR Well 45BR

47BR WZ Lockatong Well BRP2 Well BRP2

48BR L17 Lockatong Well 48BR Well 48BR
Summary and Conclusions 29

49BR L17 Lockatong Well BRP2 Well 22BR

50BR L17 Lockatong Well 48BR Well 48BR

51BR L20 Lockatong Well 48BR Well 48BR

54BR -- Lockatong Well 22BR Well 22BR

56BR L17 Lockatong Well 15BR Well 56BR

60BR L19 Lockatong Well 20BR Well 20BR

61BR L19 Lockatong Well 45BR Well 45BR

65BR L14 Lockatong Well 22BR Well 22BR

1 Well 15BR pumped at 15 gal/min, 20BR at 8.5 gal/min, 22BR at 4.4 gal/min, 45 BR at 5.1 gal/min, 48BR at 13.5 gal/min, and BRP2 at 10 

gal/min 2 Well 15BR pumped at 10 gal/min, 20BR at 8.5 gal/min, 22BR at 4.4 gal/min, 45 BR at 5.1 gal/min, 48BR at 13.5 gal/min, 56BR at 5 gal/min, 

and BRP2 at 10 gal/min

Table 14. Simulated discharge points of ground-water flow paths from contaminated wells at the Naval Air Warfare Center, 

West Trenton, New Jersey, during operation of pump-and-treat system.

[WZ, weathered zone; gal/min, gallons per minute; --, not determined]

Well name

(flow path 

starting point)

Bedding unit 

(Lacombe, 2000)

Geologic 

formation Recovery-well network II1 Recovery-well network III2

Summary and Conclusions

Volatile organic compounds, predominantly trichloroethylene and its degradation products, have been detected in 

ground water in the fractured-rock aquifer at the Naval Air Warfare Center (NAWC), West Trenton, N.J. The U.S. Geological 

Survey (USGS), in cooperation with the U.S. Department of the 

Navy, has conducted an 11-year multiphase hydrogeologic 

investigation of the NAWC. The purpose of this phase of the 

investigation was to (1) estimate hydraulic and solute-transport 

properties of the aquifer, (2) estimate the velocity and travel 

time of contaminated ground water if the existing pump-andtreat system were replaced by a non-pumping remediation technique, and (3) evaluate the effect on ground-water flow of a 

change to the configuration of the network of recovery wells in 

the pump-and-treat system at the NAWC.

Hydraulic properties of the fractured-rock aquifer in the 

Lockatong Formation at the NAWC were measured using five 

aquifer tests and three tracer tests. The heterogeneous nature of 

the formation causes a wide range in values of each parameter. 

Transmissivity ranges from 95 to 1,300 ft2/d, storage coefficient from 9 x 10-5 to 5 x 10-3, effective porosity from 0.0003 

to 0.002, and longitudinal dispersivity from 4 to 7 ft. All of 

these values represent conditions at the NAWC and are not necessarily representative of other areas underlain by the Lockatong Formation. In addition, the validity of the longitudinal-dispersivity values is uncertain because the analytical-solution 

method used to determine them is based partly on the assumption that the tested aquifer is homogeneous and isotropic--an 

assumption that is not strictly valid for solute transport in the 

fractured-rock aquifer.

The velocity and travel time of ground water along flow 

paths from each contaminated well to the stream where the 

water eventually discharges under non-pumping conditions 

were computed using the effective-porosity values obtained 

from the tracer tests, an existing ground-water-flow model, and 

particle-tracking techniques. The wide range of estimated 

velocities (0.08 to 130 ft/d) is a result of the heterogeneity of the 

aquifer.

A pump-and-treat system consisting of a network of six 

recovery wells and an air-stripping treatment system has been 

in operation at the NAWC since 1998. The existing groundwater-flow model and particle-tracking techniques were used to 

estimate the effect on ground-water flow of changing the network by pumping an additional deep (165 ft deep) well at a rate 

of 5 gal/min while decreasing pumpage from a nearby shallower (41 ft deep) well by the same amount. Simulation results 

indicate that the change caused water in the areas around three 

deep contaminated wells to be captured by the new deep recovery well rather than flowing upward to the shallower well.

Acknowledgments

The authors thank Jeffrey Dale of the U.S. Department of 

the Navy, Charles Rogers of Foster Wheeler, Inc., and Christopher Francy of ECOR Solutions, Inc., for assistance in adjusting 

the pumpage distribution in the pump-and-treat system at the 

NAWC during aquifer and tracer testing. The assistance of Robert Rosman, Nicholas Smith, and Theodore Ehlke of the USGS 

in collecting field data and analyzing bromide-concentration 

data is appreciated.

Table 14. Simulated discharge points of ground-water flow paths from contaminated wells at the Naval Air Warfare Center, 

West Trenton, New Jersey, during operation of pump-and-treat system--Continued.
30 Hydraulic and Solute-Transport Properties at the Naval Air Warfare Center, West Trenton, New Jersey, 2003

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Becker, M.W., and Shapiro, A.M., 2000, Tracer transport in 

crystalline rock: Evidence of non-diffusive breakthrough 

tailing: Water Resources Research, v. 36, no. 7, p. 1677-

1686.

Becker, M.W., and Shapiro, A.M., 2003, Interpreting tracer 

breakthrough tailing from different forced-gradient tracer 

experiment configurations in fractured bedrock: Water 

Resources Research, v. 39, no. 1, p. SBH14-1 - SBH14-13.

Carleton, G.B., Welty, Claire, and Buxton, H.T., 1999, Design 

and analysis of tracer tests to determine effective porosity 

and dispersivity in fractured sedimentary rocks, Newark 

Basin, New Jersey: U.S. Geological Survey Water-Resources 

Investigations Report 98-4126A, 80 p.

Duffield, G.M., 2000, AQTESOLVE for Windows user’s 

guide: Reston, Virginia, HydroSOLVE, Inc., 164 p.

Hantush, M.S., 1962, Flow of ground water in sands of nonuniform thickness: 3. Flow to wells: Jour. Geophys. Res., v. 67, 

no. 4, p. 1527-1534.

Harbaugh, A.W., Banta, E.R., Hill, M.C., and McDonald, M.G., 

2000, Modflow-2000, the U.S. Geological Survey modular 

ground-water model—User guide to modularization concepts and the ground-water flow process: U.S. Geological 

Survey Open-File Report 00-92, 121 p.

Heath, R.C., 1983, Basic ground-water hydrology: U.S.

Geological Survey Water-Supply Paper 2220, 84 p.

International Technology Corporation, 1994, Remedial investigation report, installation restoration program, Naval Air 

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6 v.

Kruseman, G.P., and deRidder, N.A., 1990, Analysis and evaluation of pumping test data (2d

 ed.) Publication 47: 

Wageninger, the Netherlands, International Institute for Land 

Reclamation and Improvement, 370 p.

Lacombe, P.J., 2000, Hydrogeologic framework, water levels, 

and tricholoethylene contamination, Naval Air Warfare

Center, West Trenton, New Jersey, 1993-97: U.S. Geological 

Survey Water-Resources Investigations Report 98-4167,

139 p.

Lacombe, P.J., 2002, Ground-water levels and potentiometric 

surfaces, Naval Air Warfare Center, West Trenton, New Jersey: U.S. Geological Survey Water-Resources Investigations 

Report 01-4197, 38 p.

Lewis-Brown, J.C., and Rice, D.E., 2002, Simulated groundwater flow, Naval Air Warfare Center, West Trenton, New 

Jersey: U.S. Geological Survey Water-Resources Investigations Report 02-4019, 44 p.

Neuman, S.P., 1974, Effect of partial penetration on flow in 

unconfined aquifers considering delayed gravity response, 

Water Resources Research, v. 10, no. 2, p. 303-312.

New Jersey Department of Environmental Protection, 2002, 

Federal and New Jersey State primary and secondary drinking water standards as of January, 2002, accessed August 24, 

2004, on the World Wide Web at http://www.state.nj.us/dep/

watersupply/standard.htm. 

Pollack, D.W., 1994, User’s guide for MODPATH/MODPATH-PLOT, version 3: A particle-tracking post-processing 

package for MODFLOW, U.S. Geological Survey finite-difference ground-water flow model: U.S. Geological Survey 

Open-File Report 94-464, 6 chap.

Theis, C.V., 1935, The relation between the lowering of the piezometric surface and the rate and duration of discharge of a 

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Van der Kamp, G., 1985, Brief quantitative guidelines for the 

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Appendix 1 31

Appendix 1
32 Hydraulic and Solute-Transport Properties at the Naval Air Warfare Center, West Trenton, New Jersey, 2003

Appendix 1. Aquifer-test solution parameters.

Withdrawal 

well

Observation 

well

Neuman solution for an unconfined 

aquifer

Theis solution for 

a confined aquifer

Hantush solution for a 

confined, wedge-shaped 

aquifer

b (feet) Kz/Kr Sy β b (feet) Kz/Kr

b at 

withdrawal 

well 

(feet) r/a Kz/Kr

BRP2 20BR 20 0.0007 0.001 0.03 20 0.001 20 -0.06 0.001

BRP2 56BR 22.5 .002 .004 .2 22.5 .001 22.5 .6 .001

15BR BRP3 15 .01 .002 .8 15 .01 15 .01 .01

16BR 41BR 25 .002 .04 .03 25 .002 25 -.5 .002

41BR 53BR 25 .003 .04 .1 25 .001 25 .08 .01

Definition of terms:

b thickness of the saturated aquifer

Kz/Kr ratio of hydraulic conductivity in the vertical direction to hydraulic conductivity in the horizontal direction

Sy specific yield: ratio of the volume of water that drains under the influence of gravity to the volume of saturated rock 

(Heath, 1983)

β r2Kz/b2Kr, where

r is the radial distance from the withdrawal well to the observation well,

Kz is the hydraulic conductivity in the vertical direction,

b is the thickness of the saturated aquifer, and

Kr is the hydraulic conductivity in the horizontal direction (Kruseman and deRidder, 1990).

r/a radial distance (r) from the withdrawal well to the observation well divided by a constant defining the exponential variation of the aquifer thickness (a) (Kruseman and deRidder, 1990)