HYDROGEOLOGY AND GROUND-WATER FLOW, 

FRACTURED MESOZOIC STRUCTURAL-BASIN 

ROCKS, STONY BROOK, BEDEN BROOK, AND 

JACOBS CREEK DRAINAGE BASINS, 

WEST-CENTRAL NEW JERSEY

by Jean C. Lewis-Brown and Eric Jacobsen

U.S. GEOLOGICAL SURVEY 

Water-Resources Investigations Report 94-4147

APPALACHIAN VALLEYS-PIEDMONT REGIONAL AQUIFER-SYSTEMS ANALYSIS

Wsst Trenton, New Jersey 

1995
U.S. DEPARTMENT OF THE INTERIOR 

BRUCE BABBITT, Secretary

US. GEOLOGICAL SURVEY

Gordon P. Eaton, Director

For additional information 

write to:

District Chief

U.S. Geological Survey, WRD 

810 Bear Tavern Road 

West Trenton, NJ 08628

Copies of this report can be 

purchased from:

U.S. Geological Survey

Earth Science Information Center

Open-File Reports Section

Box 25286, MS 517

Denver Federal Center

Denver, CO 80225
CONTENTS

Page

Abstract..........................................^

Introduction.......................................~^

Purpose and scope...................................................................................................................................... 2

Description of study area........................................................................................................................... 6

Location and extent...................................................................................................................... 6

Geologic setting............................................................................................................................ 6

Previous investigations............................................................................................................................10

Hydrogeology.......................................................................................................................................................... 10

Hydrogeologic framework.......................................................................................................................11

Hydraulic properties of aquifers............................................................................................................ 13

Spedfic capacity.......................................................................................................................... 15

Effect of lithology......................................................................................................... 15

Effect of depth............................................................................................................... 18

Transmissivity............................................................................................................................. 18

Storage coefficient....................................................................................................................... 18

Porosity........................................................................................................................................ 18

Ground-water flow.................................................................................................................................................20

Conceptual model of ground-water flow.............................................................................................. 20

Recharge and discharge areas................................................................................................... 23

Anisotropy of sedimentary aquifers........................................................................................ 24

Effect of diabase rocks................................................................................................................ 24

Source of water to wells............................................................................................................. 27

Simulation of ground-water flow........................................................................................................... 27

Description of digital model..................................................................................................... 27

Grid orientation and discretization........................................................................... 27

Boundary conditions................................................................................................... 29

Upper boundary and simulation of surface water................................... 29

Lateral boundaries......................................................................................... 31

Lower boundary............................................................................................32

Calibration of digital model...................................................................................................... 32

Water levels...................................................................................................................32

U.S. Geological Survey water-level data.................................................... 38

Well-completion-record data....................................................................... 39

Base flow....................................................................................................................... 40

Limitations of digital model..................................................................................................... 40

Prepumping water budgets..................................................................................................................... 41

Base flow and direct runoff .......................................................................................................41

Initial estimates ............................................................................................................41

Stony Brook drainage basin......................................................................... 41

Beden Brook and Jacobs Creek drainage basins .......................................44

Effect of anisotropy......................................................................................................44

Base-flow rates in the digital model.......................................................................... 45

Ground-water pumpage............................................................................................................45

Ground-water flow to and from adjoining drainage basins................................................48

Areal recharge............................................................................................................................. 49

Initial estimates............................................................................................................49

Effect of diabase rocks................................................................................................. 51

Effect of Hopewell Fault............................................................................................. 53

Areal recharge rates in the digital model................................................................. 53
CONTENTS-Continued

Page

Values of hydraulic conductivity and conductance from calibrated digital model........................ 53

Horizontal hydraulic conductivity in the direction of strike............................................... 55

Diabase rocks................................................................................................................55

Stockton Formation...................................................................................................... 55

Lockatong Formation..................................................................................................56

Passaic Formation........................................................................................................56

Fault zone...................................................................................................................... 56

Areas near streams.......................................................................................................56

Horizontal anisotropy ratio......................................................................................................57

Vertical hydraulic conductance................................................................................................ 57

Streambed hydraulic conductance...........................................................................................58

Vertical distribution of ground-water flow........................................................................................... 59

Summary and conclusions.....................................................................................................................................59

References cited.......................................................................................................................................................62

ILLUSTRATIONS

Figures 1-4. Maps showing:

1. The Appalachian Valleys-Piedmont Regional Aquifer-Systems Analysis study

area and physiographic provinces............................................................................. 3

2. Exposed Mesozoic basins in the eastern United States................................................... 4

3. Location of the study area.................................................................................................... 5

4. Geology of the study area, Stony Brook, Beden Brook, and Jacobs Creek drainage

basins, west-central New Jersey................................................................................. 8

5. Generalized geologic section through the study area, Stony Brook, Beden Brook, and

Jacobs Creek drainage basins, west-central New Jersey.................................................... 9

6. Generalized sections through the study area showing fracture patterns, Stony Brook,

Beden Brook, and Jacobs Creek drainage basins, west-central New Jersey.................. 12

a. Section parallel to strike of bedding 

b. Section parallel to dip of bedding

7. Fracture density in rock cores from wells 210359,190250, and 210290, west-central

New Jersey.............................................................................................................................. 14

8. Prepumping ground-water levels in and near the study area, Stony Brook,

Beden Brook, and Jacobs Creek drainage basins, west-central New Jersey.................. 21

9. Hydrographs of water levels in wells in the Stony Brook and Jacobs Creek drainage

basins, west-central New Jersey........................................................................................... 22

10. Schematic section showing hypothetical ground-water flow paths in the study area, 

Stony Brook, Beden Brook, and Jacobs Creek drainage basins, west-central New 

Jersey.......................................................................................................................................^

11. Map showing drawdown at end of aquifer test in Stony Brook drainage basin,

west-central New Jersey........................................................................................................ 26

12. Map showing discretization and orientation of digital-model grid and locations of 

model cells containing streams, Stony Brook, Beden Brook, and Jacobs Creek 

drainage basins, west-central New Jersey.......................................................................... 28

13. Schematic representation of model boundary conditions, layers, and zones of different 

hydraulic conductivity, Stony Brook, Beden Brook, and Jacobs Creek 

drainage basins, west-central New Jersey.......................................................................... 30

iv
ILLUSTRATlONS-Continued

Page

Rgure 14. Map showing location of water-level-measurement sites and difference between 

measured and simulated water levels, Stony Brook, Beden Brook, and 

Jacobs Creek drainage basins, west-central New Jersey.................................................. 35

15. Maps showing prepumping water levels in the study area, Stony Brook, Beden Brook, 

and Jacobs Creek drainage basins, west-central New Jersey:

a. Interpreted .................................................................................................................36

b. Simulated...................................................................................................................37

16. Diagrams showing simulated average-annual prepumping water budgets, 1954-91: 

a. Stony Brook drainage basin, west-central New Jersey, upstream from

streamflow-gaging station 01401000...................................................................... 42

b. Beden Brook drainage basin, west-central New Jersey....................................... 42

c. Jacobs Creek drainage basin, west-central New Jersey....................................... 42

17. Map showing base-flow-measurement sites, Stony Brook, Beden Brook, and Jacobs

Creek drainage basins, west-central New Jersey............................................................... 43

18. Map showing location of public supply, industrial, and commercial wells, Stony Brook,

Beden Brook, and Jacobs Creek drainage basins, west-central New Jersey..................47

TABLES

Table 1. Geologic units in the study area, Stony Brook, Beden Brook, and Jacobs Creek drainage

basins, west-central New Jersey.................................................................................................. 7

2. Yield, specific capacity, and specific capacity per foot of open hole of wells in and near 

the study area, Stony Brook, Beden Brook, and Jacobs Creek drainage basins, 

west-central New Jersey............................................................................................................. 16

3. Transmissivity and storage coefficient estimated from results of aquifer tests at selected

sites in the Newark Basin, New Jersey and Pennsylvania..................................................... 19

4. Records of selected wells in and near the Stony Brook, Beden Brook, and Jacobs Creek 

drainage basins, west-central New Jersey:

a. Data obtained from U.S. Geological Survey Ground-Water Site Inventory

data base...................................................................................................................... 66

b. Data obtained from published reports.......................................................................... 71

5. Measured and simulated water levels in selected wells in the study area, Stony Brook,

Beden Brook, and Jacobs Creek drainage basins, west-central New Jersey........................ 33

6. Reported ground-water pumpage exceeding 1 million gallons per year in the Stony Brook,

Beden Brook, and Jacobs Creek drainage basins, west-central New Jersey, 1987............. 46

7. Mean-monthly air temperature, potential evapotranspiration, and precipitation in the 

study area, Stony Brook, Beden Brook, and Jacobs Creek drainage basins, 

west-central New Jersey .............................................................................................................50

8. Ground-water-runoff rates in areas underlain by diabase rocks and areas underlain by all 

rock types in the Stony Brook, Beden Brook, and Jacobs Creek drainage basins, 

west-central New Jersey.............................................................................................................52

9. Simulated values of hoizontal hydraulic conductivity, vertical conductance, and streambed 

conductance factor in the Stony Brook, Beden Brook, and Jacobs Creek drainage 

basins, west-central New Jersey................................................................................................ 54
CONVERSION FACTORS AND VERTICAL DATUM

Multiply

inch (in.) 

foot (ft) 

mile (mi)

By 

Length

25.4

0.3048

1.609

To obtain

millimeter

meter

kilometer

foot per mile (ft/mi2)

Slope

0.1894 meter per kilometer

square mile (mi2 )

Area

2.590 square kilometer

foot per day (ft/d) 

inch per year (in./yr) 

cubic foot per day per

square foot times

foot of aquifer

thickness [[(ftVdJ/ftfyt] 

foot squared per day (ftVd) 

gallon per minute (gal/min) 

cubic foot per day (ftVd) 

cubic foot per second (ft3 /s)

Flow

0.3048

25.4

0.09294

0.09294

0.06308

0.02832

0.02832

meter per day 

millimeter per year 

cubic meter per day per

square meter times

meter of aquifer

thickness [[(m3 /d)/m2jm] 

meter squared per day 

liter per second 

cubic meter per day 

cubic meter per second

Sea level: In this report "sea level" refers to the National Geodetic Vertical Datum of 1929-a geodetic 

datum derived from a general adjustment of the first-order level nets of both the United States and 

Canada, formerly called Sea Level Datum of 1929.

VI
HYDROGEOLOGY AND GROUND-WATER FLOW, 

FRACTURED MESOZOIC STRUCTURAL-BASIN ROCKS, 

STONY BROOK, BEDEN BROOK, AND JACOBS CREEK 

DRAINAGE BASINS, WEST-CENTRAL NEW JERSEY

by Jean C. Lewis-Brown and Eric Jacobsen

ABSTRACT

This study was undertaken to characterize ground-water flow in the Stony Brook/ Beden 

Brook, and Jacobs Creek drainage basins in west-central New Jersey. The study area/ an 89- 

square-mile area/ is underlain by dipping beds of fractured siltstone/ shale/ and sandstone and 

by massive diabase sills. The density of fractures in all the rocks decreases with depth. Rocks on 

both sides of the major fault that extends through the study area are extensively fractured.

The average annual rates of precipitation and ground-water recharge in the study area 

are 45.07 inches and 8.58 inches, respectively. The rate of recharge to the diabase rocks is about 

one-half the rate of recharge to other rocks. Part of the surface runoff from the diabase rocks 

flows downslope and recharges the ground-water system where more permeable rocks crop out.

The decrease in the density of fractures with depth is reflected in specific-capacity data. 

The specific capacity per foot of open hole of wells that are less than 76 ft deep is two to six times 

greater than that of wells 76 to 100 ft deep. Because water-bearing units dip/ they are more 

extensive in the strike direction than in the dip direction/ and ground-water flow is skewed 

toward the strike direction. Ground-water divides generally coincide with surface-water 

divides/ and most ground-water flow in the study area follows short flow paths from the point of 

recharge to a nearby stream. Most ground-water flow in the study area occurs between the water 

table and 75 ft below land surface. When the system is unstressed/ only about 6 percent of the 

recharge at land surface reaches depths greater than 75 ft below land surface.

A three-dimensional digital model of steady-state/ prepumping ground-water flow was 

developed to test hypotheses concerning the geologic features that control ground-water flow in 

the study area. The decrease in the density of interconnected fractures with depth was simulated 

by dividing the model into two layers of different hydraulic conductivity. Over most of the 

model area, the upper layer represents the part of the system between the water table and 75 ft 

below land surface/ and the lower layer represents the part of the system deeper than 75 ft below 

land surface. The pinching out of water-bearing units in the dip direction at land surface and at 

depth was represented by setting the hydraulic conductivity in the dip direction 2 times lower 

than in the strike direction for the upper layer and 10 times lower than the strike direction for the 

lower layer. The vertical conductivity was slightly higher than the dip-direction horizontal 

conductivity. This model is appropriate for the analysis of ground-water flow in areas greater 

than about 0.5 square mile in size and if analysis of flow in discrete water-bearing units is not 

needed.
INTRODUCTION

This report is a result of the Appalachian Valleys-Piedmont Regional Aquifer-System 

Analysis (RASA) study. The Appalachian Valleys-Piedmont RASA is one of several regional 

investigations being conducted to assess the Nation's principal aquifer systems (Sun, 1986). The 

U.S. Geological Survey (USGS) began the RASA program in 1978, as mandated by Congress, and 

was given the task of "initiating a program to identify the water resources of the major aquifer 

systems within the United States.. .and... establish the aquifer boundaries, the quantity and 

quality of the water within the aquifer, and the recharge characteristics of the aquifer" (Sun, 1986, 

p. 2).

The objectives of the Appalachian Valleys-Redmont RASA include an identification of 

the major hydrogeologic terranes within the Valley and Ridge, Piedmont, Blue Ridge, and New 

England physiographic provinces (fig. 1) and a quantitative assessment of the components of the 

ground-water flow systems in typical areas within each major hydrogeologic terrane (Swain and 

others, 1991, p. 3).

The Mesozoic structural basins of the eastern United States comprise one of the major 

hydrogeologic terranes studied by the USGS as part of the Appalachian Valleys-Piedmont 

Regional Aquifer-Systems Analysis. The basins extend from Massachusetts to South Carolina 

(fig. 2). Aquifers in three of these basins-the Newark, Gettysburg, and Culpeper Basins are 

used extensively for ground-water supply. To characterize flow in these structural basins, an 

89 mi2 area of the Newark Basin in west-central New Jersey (fig. 3) was chosen for detailed study.

Ground water is the primary source of potable water in the study area. Water-supply 

systems serve Hopewell and Pennington Boroughs; most other residential and commercial users 

obtain their water from privately owned wells (Jacobsen and others, 1993, p. 4).

Effective management of ground-water supplies requires an understanding of the 

ground-water flow system. The flow system in Mesozoic-basin rocks, however, has been poorly 

understood because the hydrogeologic framework consists of layered clipping beds in which 

water flows primarily in a complex network of several types of fractures.

Purpose and Scope

This report describes ground-water flow in the Stony Brook, Beden Brook, and Jacobs 

Creek drainage basins, west-central New Jersey. The hydrogeologic framework is discussed, and 

the effects of geology and depth on hydrologic properties are evaluated on the basis of results of 

1,492 specific-capacity tests conducted in and near the study area. Transmissivity and storage 

coefficient estimated from results of 37 aquifer tests in the Newark Basin conducted before this 

study are also included. A conceptual model of the ground-water flow system that includes 

generalized ground-water flow paths and an identification of recharge and discharge areas is 

described. A map of prepumping water levels in 544 wells in and near the study area is 

included. The digital model that was used to analyze factors affecting ground-water flow in the 

study area and to test hypotheses developed in the conceptual model is described. An analysis 

of ground-water flow is presented, including the effect of diabase rocks on the ground-water 

flow system, the vertical distribution of ground-water flow, the source of water to wells, and the 

effect of anisotropy on base flow to streams. Average-annual water budgets for the Stony Brook, 

Beden Brook, and Jacobs Creek drainage basins also are included.
EXPLANATION

PHYSIOGRAPHIC PROVINCES 

WITHIN STUDY AREA

Valley and Ridge 

Piedmont

Blue Ridge and 

New England

100 200 MILES i

0 100 200 KILOMETERS 

I

Figure 1. The Appalachian Valleys-Piedmont Regional Aquifer-Systems 

Analysis study area and physiographic provinces. (From Swain and others, 

1991, figl.)
0 100 200 300 MILES

EXPLANATION

Mesozoic basins:

1.Wadesboro(N.C.-S.C.)

2. Sanford (N.C.)

3. Durham (N.C.)

4. Davie County (N.C.)

5. Dan River and Danville (N.C.-Va.)

6. Scottsburg (Va.)

7. Basins north of Scottsburg (Va.)

8. Farmville (Va.)

9. Richmond (Va.)

10. Taylorsville (Va.) 

11.Scottsville(Va.)

12. Barboursville (Va.)

13. Culpeper (Va.-Md.)

14. Gettysburg (Md.-Pa.)

15. Newark (N.J.-Pa.-N.Y.)

16. Pomperaug (Conn.)

17. Hartford (Conn.-Mass.)

18. Deerfield (Mass.)

100 200 300 400 KILOMETERS

Figure 2. Exposed Mesozoic basins in the eastern United States. (Modified 

from Froelich and Olsen, 1985, fig. 1.1.)
cn

N

I I

0 15 30 45 KILOMETERS

Base from U.S. Geological Survey digital data, 

1:2,000,000, 1972, Universal Transverse 

Mercator Projection, Zone 18

Base from U.S. Geological Survey, 1:24,000 quadrangles, 

Stockton, 1954; Lambertville, 1942; Hopewell, 1942; 

Pennington, 1954; Princeton, 1954; Rocky Hill, 1942

Figure 3. Location of the study area.
Description of Study Area

The study area is located in the southern part of the Newark Basin of New Jersey. It was 

chosen to typify the Mesozoic basins of the eastern United States because it contains most of the 

rock types and geologic structures prevalent in the basins, including the diabase intrusions and a 

major fault-the Hopewell Fault.

Location and Extent

The study area is located in west-central New Jersey and encompasses approximately 

89 mi2 in Mercer, Somerset, and Hunterdon Counties (fig. 3). It includes the entire Stony Brook 

and Jacobs Creek drainage basins and the part of the Beden Brook drainage basin upstream from 

U.S. Route 206. In this report, "Beden Brook drainage basin" refers specifically to the area 

contributing drainage to Beden Brook upstream from U.S. Route 206. The two larger basins, 

Stony Brook and Beden Brook, drain into the Raritan Bay. The smallest basin, Jacobs Creek, 

drains into the Delaware River.

The Boroughs of Hopewell, Pennington, Princeton, and Rocky Hill (fig. 3) border or lie 

within the study area. They are primarily residential communities that include or are 

surrounded by agricultural and wooded areas. Several corporate research facilities also are 

located within the area, but farms and woodlands still dominate the landscape.

The study area lies entirely within the Piedmont physiographic province. The 

topography consists of ridges and broad valleys; relief is greatest in the northwestern part and 

diminishes toward the southeast. Altitudes range from a high of 570 ft above sea level in the 

northwest to a low of about 20 ft above sea level at the mouth of Jacobs Creek.

Geologic Setting

The study area is underlain by three geologic units of the Newark Supergroup of Late 

Triassic and Early Jurassic age (table 1, figs. 4 and 5). Following deposition, the geologic rock 

units were intruded by diabase sills, tilted, fractured, and eroded. As a result of tilting, the units 

dip about 12 to 15 degrees toward the northwest and strike northeast (Vecchioli and Palmer, 

1962, p. 10).

The Stockton Formation, the oldest unit, crops out in the southeastern corner of the 

study area. In the study area, the Stockton Formation consists of red and gray arkosic sandstone 

interbedded with shale. It is overlain by the Lockatong Formation, which crops out to the 

northwest of the Stockton Formation. The Lockatong Formation consists mainly of alternating 

beds of siltstone and shale with minor amounts of fine-grained sandstone. Many of the siltstone 

and sandstone beds are extremely hard, chemically cemented siltstone and fine-grained 

sandstone (argillite) (Houghton, 1990, p. E8). Zones of sandy siltstone within the Lockatong 

Formation that are similar to the rocks in the overlying Passaic Formation were mapped as 

separate units by Lyttle and Epstein (1987). The Passaic Formation of Olsen (1980), which crops 

out in the central part of the study area, is composed of dull red shale interbedded with siltstone 

and occasional layers of sandstone (Barksdale and others, 1943, p. 141). Some zones of rocks 

similar to those of the Lockatong Formation have been mapped within the Passaic Formation 

(Lyttle and Epstein, 1987).
Table 1. Geologic units in the study area. Stony Brook. Beden Brook, and Jacobs Creek 

drainage basins, west-central New Jersey

[Modified from Lyttle and Epstein, 1987, sheet 2]

Geologic unit Age Lithology

Diabase Early Jurassic Dikes, sills, and sill-like intrusives. 

Fine- to coarse-grained (except very 

fine to fine-grained near chilled 

borders) diabase.

Passaic Formation of 

Olsen (1980)

Early Jurassic and 

Late Triassic

Thin- to thick-bedded shale, siltstone, 

and very fine to coarse-grained 

sandstone. Contains thin-bedded shale 

and siltstone similar to the rocks in 

the underlying Lockatong Formation.

Lockatong Formation

Stockton Formation

Late Triassic

Late Triassic

Laminated to thick-bedded siltstone and 

shale. Contains interbedded sandy 

siltstone similar to the rocks in the 

overlying Passaic Formation.

Thin- to thick-bedded, very fine- to 

coarse-grained sandstone, siltstone, 

and shale.
EXPLANATION

Diabase

Passaic Formation of Olsen (1980).

Contains strata (JTrpg) similar to the

rocks in the underlying Lockatong Formation

Lockatong Formation. Contains strata 

(Trlr) similar to the rocks in the overlying 

Passaic Formation

Trace of geologic section 

shown in figure 5

Generalized strike and 

dip of rock layers

Trace of fault 

210359 Well location and number

Stockton Formation

74°45'

190250

Pennington 

Mountain

40°20'

Trl Sourland Mountain

74°50'

40°25'

Hopewell Fault 

JTrp

210359

Study-area boundary

3 MILES

210028 0123 KILOMETERS

Figure 4. Geology of the study area, Stony Brook, Beden Brook, and Jacobs Creek 

drainage basins, west-central New Jersey. (Modified from Lyttle and Epstein, 1987, 

sheet 1.)

8
VERTICAL EXAGGERATION x 20

2 MILES

2 KILOMETERS

EXPLANATION

Diabase

Passaic Formation of Olsen (1980).

Contains strata (JTrpg) similar to the

rocks in the underlying Lockatong Formation

Lockatong Formation. Contains strata 

(Trlr) similar to the rocks in the overlying 

Passaic Formation

Stockton Formation

Lines of contact between geologic units

Trace of Hopewell Fault and 

relative movement along the 

fault

Figure 5. Generalized geologic section through the study area, Stony Brook, 

Beden Brook, and Jacobs Creek drainage basins, west-central New Jersey. 

(Location of section shown in fig. 4.)
The sequence of the three outcropping sedimentary geologic units-the Stockton, 

Lockatong, and Passaic Formations is repeated in the northwestern part of the study area as a 

result of the presence of the Hopewell Fault. The Hopewell Fault strikes northeast and dips 

about 30 degrees to the southeast (Ratcliffe and Burton, 1985, p. 38). When the fault occurred/ the 

rock formations on the southeastern side of the fault slid downward relative to the rocks on the 

northwestern side. After faulting, rocks on the upthrown side of the fault escarpment were 

eroded extensively. Today, land surface on the upthrown side of the fault is only about 200 ft 

higher than that on the downthrown side. Extensive erosion on the upthrown (northwestern) 

side of the fault resulted in the exposure of older geologic units and the repetition of outcropping 

formations.

The thicknesses of the Stockton, Lockatong, and Passaic Formations in the study area are 

estimated to be 5,000,6,000, and 14,000 ft, respectively. These estimates were made on the basis 

of outcrop widths (fig. 4) and an approximate average dip of 13.5 degrees to the northwest.

Diabase sills intruded into the sedimentary rocks in several places. The diabase is 

composed predominantly of very hard, fracture-resistant calcic plagioclase and augitic pyroxene 

(Houghton, 1990, p. El 8). Because of its pronounced resistance to erosion, the diabase forms the 

highest ridges in the study area.

When the diabase intruded, the surrounding sedimentary rocks were altered by heat and 

pressure to hard hornfels rocks. The hydraulic properties of the hornfels rocks resemble those of 

the argillite rocks of Lockatong Formation (Kasabach, 1966, p. 33). The width of the altered zone 

probably does not exceed a few hundred feet (Greenman, 1955, p. 33).

Previous Investigations

The geology and ground-water resources of Mercer County have been described by 

Vecchioli and Palmer (1962) and Widmer (1965). The geology and ground-water resources of 

Hunterdon County were described by Kasabach (1966). Vecchioli and others (1969) reported on 

the occurrence and movement of ground water in shales of the Brunswick Group at a site in the 

Stony Brook drainage basin. Gerhart and Lazorchick (1988) described ground-water resources in 

the Susquehanna River basin of Pennsylvania and Maryland, which includes part of the 

Gettysburg Mesozoic structural basin, and Laczniak and Zenone (1985) reported on groundwater resources in the Culpeper basin of Virginia and Maryland. A geologic map of the Newark 

quadrangle that includes the study area was compiled by Lyttle and Epstein (1987). BetzConverse-Murdoch, Inc. (1978), conducted a study of the effects of sewering and increased 

demand on ground-water resources in the northwestern part of Mercer County, New Jersey. 

Houghton (1990) reported on the hydrogeology of the Mesozoic rocks of the Newark Basin of 

New Jersey. Reading and Kurtz (1982) described the biology and chemistry of Beden Brook. 

Jacobsen and others (1993) conducted a study of surface- and ground-water quality, base-flow 

rates, and ground-water levels in the study area. Lewis (1992) reported on the effect of 

anisotropy on ground-water discharge to streams in the study area.

HYDROGEOLOGY

The distribution of fractures in the aquifers of the study area is the most important 

control on the rates and directions of ground-water flow because the fractures are the primary 

paths for ground-water movement and the primary reservoirs for ground-water storage in these 

rocks.

10
Hydrogeologic Framework

The aquifers in the study area consist of the fractured Mesozoic sedimentary rocks in the 

shallow parts of the Stockton, Lockatong, and Passaic Formations/ and diabase rocks. These 

geologic formations extend thousands of feet below land surface, but interconnected, waterbearing fractures are present only from land surface to a depth of about 500 ft. Although the 

lithology and extent of fracturing differ among the three sedimentary formations, all three are 

characterized by several layers of extensively fractured rocks that typically are 1 to 10 ft thick 

interbedded with layers of sparsely fractured rocks that typically are 30 to 100 ft thick 

(Houghton, 1990, p. E18). In extensively fractured layers, joints parallel to bedding predominate. 

In this report, the extensively fractured layers are termed "water-bearing units," and the sparsely 

fractured layers are termed "confining units." The term "aquifer" refers to the entire 500-ft-thick 

sequence of water-bearing units and confining units. The hydrogeologic framework of the study 

area is illustrated schematically in figures 6a (section oriented parallel to strike) and 6b (section 

oriented parallel to dip). Each of these generalized sections represents only a small (about 

1,000 ft wide and 500 ft deep) hypothetical part of the study area.

In the Stockton Formation, the water-bearing units are composed of sandstone and the 

confining units are composed of siltstone. In the Lockatong Formation, the water-bearing units 

are composed of fissile shale, and the confining units are composed of massive, thick-bedded 

argillaceous siltstone. The Lockatong Formation is one of the poorest sources of ground water in 

New Jersey but yields more water than the diabase rocks (Kasabach, 1966, p. 31). In the Passaic 

Formation, the water-bearing units are composed of fissile shale and siltstone, and the confining 

units are composed of massive siltstone.

In areas underlain by these sedimentary rocks, stream patterns and topography are 

controlled by the outcrop patterns of rock layers. Valleys are present where the more easily 

eroded, extensively fractured rocks crop out, whereas ridges are present where the less easily 

eroded, sparsely fractured rocks crop out. Consequently, a typical landform in the study area 

consists of long ridges and valleys parallel to the strike of the beds. Streams in the strike-aligned 

valleys generally flow into streams that are aligned parallel or subparallel to the dip of the beds. 

This is especially true in the northwestern part of the study area. This area is underlain by the 

Lockatong Formation (fig. 4). The dip-aligned streams probably follow the traces of welldeveloped vertical joints that cut across strike. The stream patterns in the study area (fig. 3) 

illustrate the tendency for many streams or stream segments to be aligned along strike 

(northeast) or along dip (northwest).

The diabase rocks are massive, hard, and sparsely fractured. Vertical fractures are spaced 

1.0 to 6.6 ft apart except at the fault, where they are more closely spaced (Houghton, 1990, 

p. E21). The range of orientations of fractures in the diabase sills typically is wider than that in 

sedimentary rocks (Houghton, 1990, p. El 8). Because fractures in the diabase are so widely 

spaced, many unsuccessful wells have been drilled into these rocks (Vecchioli and Palmer, 1962, 

p. 36).

Three types of fractures control ground-water flow in Mesozoic-basin aquifers-joints 

parallel to bedding, high-angle joints nearly perpendicular to bedding, and high-angle faults. 

Joints parallel to bedding serve as the primary flow paths in many of the water-bearing beds. In 

water-bearing units composed of fissile mudstone and shale, some bedding-plane fractures are 

less than 1 inch apart (Houghton, 1990, p. E25).

11
sw NE

Weathered 

zone

Waterbearing 

units

Confining <" 

units ^

Unconfined 

zone

Confined 

zone

a. Vertical section parallel to strike of bedding.

NW SE

Weathered 

zone

Waterbearing 

units

Confining*^ 

units ^

Unconfined 

zone

Confined 

zone

b. Vertical section parallel to dip of bedding.

EXPLANATION 

Fracture

 Approximate location of transition from 

unconfined to confined conditions

Figure 6. Generalized sections through the study area showing fracture patterns, Stony Brook, 

Beden Brook, and Jacobs Creek drainage basins, west-central, New Jersey.

12
High-angle joints provide interconnection between water-bearing units (Houghton, 1990, 

p. E24). High-angle joints are present in several orientations. The most common (principal) 

orientation of high-angle joints is northeast striking and southeast-dipping (Houghton, 1990, p. 

E23). Outcrop evidence indicates that these principal joints are extensive vertically and 

horizontally (Houghton, 1990, p. E23). Vertically, such joints commonly are continuous through 

massive (confining) units and terminate in shaly (water-bearing) units (Houghton, 1990, p E24). 

Other high-angle joints are found in up to three different directions at some locations.

The Hopewell Fault is typical of high-angle faults prevalent in the Mesozoic basins. 

Rocks on both sides of the fault are densely fractured. Many wells near the Hopewell Fault have 

higher yields than wells in similar unfaulted rock. These high yields indicate that the aquifers 

are more permeable in the fault zone than in surrounding areas.

Throughout the study area, the rocks near land surface are extensively weathered. In the 

weathered zone, circulating ground water has widened fractures and dissolved some of the 

intergranular cement in the sedimentary rocks, especially in the Stockton Formation (Houghton, 

1990, p. E22). Rocks below the weathered zone, which is generally about 75 ft thick, have no 

intergranular porosity.

The density of horizontal and vertical fractures decreases with depth. The number of 

fractures in rock cores from the Stockton, Passaic, and Lockatong Formations of the Newark 

Basin in New Jersey is shown in figure 7 (Dorothy Payne, U.S. Geological Survey, written 

commun., 1991). The locations from which the rock cores were collected are shown in figure 4. 

At all three locations, the density of fractures decreases with depth. An analysis of geologic logs 

of wells drilled in the Newark Basin of Pennsylvania also indicates that the density of fractures 

decreases with depth (Greenman, 1955, p. 25).

Interconnected, water-bearing fractures are estimated to be present only in rocks less 

than 500 ft below land surface. This estimate was based on the fact that extending well depths 

beyond 500 ft usually does not increase well productivity (Greenman, 1955, p. 25).

Unconfined conditions commonly exist in the uppermost zone of water-saturated 

subsoil, weathered and broken bedrock, and competent bedrock because pores and fractures in 

this material commonly are well-connected (Houghton, 1990, p E20). Below a certain depth, 

which varies from about 50 to 150 ft, confined conditions are caused by the presence of lowpermeability layers containing relatively few fractures (Houghton, 1990, p. E21).

Depth to bedrock in the study area generally is less than 10 ft. The material on top of the 

bedrock is unconsolidated clayey silt and sand made up of residual materials from the 

weathering of bedrock (Holman and others, 1954, p. 23,39,42, and 45).

Hydraulic Properties of Aquifers

Specific-capacity tests and aquifer tests have been performed in the aquifers of the 

Newark Basin to obtain estimates of hydraulic properties of the aquifers. Because tests were 

performed by using wells that are open to several water-bearing units, they provide information 

on the aquifer as a whole rather than on discrete water-bearing units.

13
NUMBER OF FRACTURES

50 

Ul 

Ul 

LL

Ul 

O

2

QC

O

z 

<

O

Ul 

CO

X

0. 

Ul

O

100 

150 

200-

250-

300

350 

400 

10

I

20 0 10

I

20 0 10 20

I

450^

Well 210359 Well 190250 Well 210290 

Stockton Formation Passaic Formation Lockatong Formation

Figure 7. Fracture density in rock cores from wells 210359, 190250, and 

210290, west-central New Jersey.

14
Specific Capacity

Results of specific-capacity tests of 1,492 wells in and near the study area were analyzed 

to determine the effects of lithology and depth on specific capacity of wells. All wells used in 

this analysis are domestic wells that are 6 inches in diameter. Public supply and industrial wells 

were excluded from the analysis because many of these wells are drilled by using methods that 

maximize yield, and many are located where yield is expected to be greatest. Consequently, 

these wells probably are not representative of average, or random, conditions. Most wells in the 

study area are 6 inches in diameter. Wells of other diameters were excluded from this analysis to 

eliminate the effect of well diameter on specific capacity.

The 1,492 wells include all wells listed in previously published reports (Vecchioli and 

Palmer, 1962 p. 48-108; Widmer, 1965, p. 52-59; and Kasabach, 1966, p. 58-127) that meet the 

above criteria and that are open to one of the aquifers in the study area. Wells in Mercer, 

Hunterdon, and Somerset Counties in the USGS Ground-Water Site Inventory data base also 

were included in the analysis. Although many of these wells are outside of the study area, they 

are in the same aquifers as those in the study area. The use of a larger number of wells than those 

in the study area alone (approximately 400) provided a sufficiently large sample for comparisons 

to be made among wells in various aquifers and wells of various depths (table 2).

Effect of lithology

A comparison of yield, specific capacity, and specific capacity per foot of open hole 

among the aquifers in the study area reveals that each aquifer has different hydraulic properties 

(table 2). Specific capacity per foot of open hole probably is a better measure of hydraulic 

properties than yield or specific capacity alone because the effect of the length of the open hole is 

taken into account and because the length of well openings in these wells ranges from 5 to 648 ft. 

Additionally, specific capacity per foot of open hole has been shown to be directly proportional 

to hydraulic conductivity (Theis and others, 1963). The median specific capacity per foot of open 

hole of wells in the Stockton, Lockatong, and Passaic Formations is 0.00545,0.00115, and 0.00393 

((gal/min)/ft)/ft (gallons per minute per foot per foot), respectively. For wells in diabase rocks, 

the median specific capacity per foot of open hole is 0.00143. The wells in diabase rocks included 

in this analysis were all wells that were completed and put into service. Many unsuccessful 

wells have been drilled into diabase rocks, however; if data for these unsuccessful wells were 

available and were included in the analysis, the median specific capacity per foot of open hole for 

diabase rocks probably would be much lower. These data indicate that the Stockton Formation is 

the most permeable aquifer in the region and diabase is the least permeable.

Specific-capacity data are available for 49 wells in hornfels rocks of the Passaic Formation 

located at the edges of diabase sills. The median specific capacity per foot of open hole of these 

wells is 0.00097 ((gal/min)/ft)/ft, much lower than that of the other wells in the Passaic 

Formation.

Data also are available for 18 wells in the part of the Passaic Formation containing 

Lockatong-like rocks. The median specific capacity per foot of open hole of these wells, is 

0.00130 ((gal/min)/ft)/ft.

15
Table 2. Yield, specific capacity, and specific capacity per foot of open hole of wells in and near the 

study area. Stony Brook. Beden Brook, and Jacobs Creek drainage basins, west-central New Jersey

[All wells are 6 inches in diameter and are used only for domestic purposes; gal/min, gallons per minute; 

ft, foot]

Depth of wells 

(ft)

Number of 

wells

Median yield 

(gal/min)

Median 

specific 

capacity 

[(gal/min)/ft]

Median specific 

capacity per 

foot of open hole 

[<(gal/min)/ft)/ft]

Wells in Stockton Formation

0-75 

76-100 

101-125 

126-150 

151-175 

176-200 

201-250 

251-300

301+

31

64

63

47

18

13

17

8

10

18.0

15.0

20.0

15.0

27.0

15.0

12.0

57.5

135.0

0.952

.620

.400

.300

.749

.324

.343

.434

1.530

0.03210

.01061

.00440

.00282

.00911

.00257

.00243

.00172

.00393

All wells 271 15.0 0.488 .00545

Wells in Lockatong Formation

0-75

76-100

101-125

126-150

151-175

176-200

201-250

251-300

301+

All wells

17

67

58

58

39

27

33

15

34

348

12.0

9.0

6.0

7.5

8.0

6.0

6.0

8.0

5.5

7.0

0.526

.233

.128

.161

.133

.066

.080

.088

.037

0.115

0.01240

.00370

.00167

.00140

.00086

.00039

.00042

.00032

.00011

.00115

16
study area, Stony Brook, Beden Brook, and Jacobs Creek drainaee basins. west-central New Tersev 

Continued

Depth of wells 

(ft)

Number of 

wells

Median yield 

(gal/min)

Median 

specific 

capacity 

[(gal/min)/ft]

Median specific 

capacity per 

foot of open hole 

[((gal/min)/ft)/ft]

Wells in Passaic Formation

0-75

76-100

101-125

126-150

151-175

176-200

201-250

251-300

301+

11

58

127

180

130

75

66

32

30

15.0

15.0

15.0

15.5

15.0

17.0

12.0

11.0

19.0

0.545

.500

.461

.667

.644

.345

.227

.129

.236

0.01520

.00771

.00536

.00601

.00471

.00223

.00109

.00051

.00076

All wells 709 15.0 0.462 0.00393

Wells in Passaic Formation-contact metamorphic zones

All wells 49 6.0 0.113 0.00097

Wells in Passaic Formation Lockatong-like strata

All wells 18 7.0 0.105 0.00130

Wells in diabase rocks

0-75

76-125

126+

All wells

25

39

33

97

8.0

5.0

5.0

5.0

0.208

.096

.040

0.109

0.00906

.00143

.00023

0.00143

17
Effect of depth

The specific-capacity data (table 2) indicate that hydraulic conductivity decreases as 

depth below land surface increases, and that the largest decrease in hydraulic conductivity 

occurs at about 75 ft below land surface. For wells up to 75 ft deep in the Stockton, Lockatong, 

and Passaic Formations, the specific capacity per foot of open hole is 2.0 to 3.4 times that of wells 

76 to 100 ft deep. For wells in the diabase rocks, the specific capacity per foot of open hole of 

wells up to 75 ft deep is 6.3 times that of wells 76 to 125 ft deep. Because the open intervals of 

wells that are 76 to 100 ft deep encompass the depths above as well as below 75 ft, the actual 

specific capacity per foot of open hole for the zone 76 to 100 ft below land surface must be much 

less than the specific capacity per foot of open hole for the entire open interval of the wells.

The decrease in specific capacity with depth is a result of the decrease in the density of 

fractures and the decrease in the effects of weathering. Although the most transmissive zone 

generally is between land surface and 75 ft below land surface, most wells are drilled deeper 

than 75 ft for two reasons. First, the additional well bore provides increased storage for water 

entering the well bore, and the increased storage augments the water supply. Second, the water 

obtained from the first 75 ft may not be sufficient, and the well is deepened so that additional 

water-bearing zones contribute water to the well.

Transmissivity

Estimates of transmissivity are summarized in table 3. These data are compiled from the 

literature and are based on results of aquifer tests conducted during previous studies. Estimates 

range from 100 to 4,700 ftVd for the Stockton Formation, and from 900 to 4300 ft 2/d for the 

Passaic Formation . No reports of aquifer tests in the Lockatong Formation or in diabase rocks 

are available. For most of these estimates, no information was given regarding the method used 

to estimate transmissivity from aquifer-test data. If the method was inappropriate for the type of 

aquifer, the estimated transmissivity may be higher or lower than the actual value. For example, 

if data on an anisotropic aquifer is analyzed by using methods applicable to isotropic aquifers, 

the estimated transmissivity could be either too high or too low depending on the location of the 

observation well relative to that of the pumped well. This may explain the wide ranges in 

transmissivity and storativity based on aquifer-test results.

Storage Coefficient

Reported storage coefficients estimated on the basis of results of aquifer tests in wells in 

the Stockton Formation range from 0.00001 to 0.367 (table 3). No estimates of storage coefficient 

have been reported for the other aquifers in the study area.

Porosity

The porosity of most rocks in the study area cannot be measured directly because it is due 

predominantly to fractures. Herpers and Barksdale (1951, p. 27) estimated that the volume of 

fractures in the upper 300 ft of the Passaic Formation was about 1 or 2 percent of the total rock 

volume, but the method used to estimate the volume of cracks is unknown. Rima and others 

(1962, p. 29) reported on laboratory tests on 12 samples of rock from the Stockton Formation in 

Pennsylvania. The porosity of those samples ranged from 7.1 to 30.6 percent. The depths from 

which these samples were obtained were not reported, but it is likely that they were from 

relatively shallow depths, where intergranular porosity is found in the Stockton Formation.

18
in the Newark Basin, New Jersey and Pennsylvania

[ft2 /d, square feet per day; -, no data available]

Location

Transmissivity 

(frVd)

Storage 

coefficient Remarks Reference

Stockton Formation

Phoenixville, Pennsylvania

Phoenixville, Pennsylvania

Phoenixville, Pennsylvania

Norristown, Pennsylvania

Norristown, Pennsylvania

Blue Bell, Pennsylvania

Doylestown, Pennsylvania

Doylestown, Pennsylvania

Doylestown, Pennsylvania

Langhorne, Pennsylvania

Chester County, Pennsylvania

Chester County, Pennsylvania

Middlesex County, New Jersey

New Jersey and Pennsylvania

New Jersey and Pennsylvania

Mercer County, New Jersey

2,400

2,000

2,100

3,100

3,200

130

1,100

2,100

1,900

3,100

1,460

260

1,750

100-4,700

700

1,100

0.0002

-

.002

.0007

.0013

-

.0002

.000

.0002

.0005

.000137

.367

.0002

.00001-.001

.00001

.0002

Mean, 2 tests, one well

Mean, 2 tests, one well

Mean, 2 tests, one well

One well

Mean, 2 tests, one well

One well

One well

One well

One well

One well

Pumped well open from 

68 to 124 feet below

land surface.

Pumped well open from 

152 to 184 feet below

land surface.

Pumped well open from 

30 to 81 feet below

land surface

"Few" tests

"Common" values

One well

1

1

1

1

1

1

1

1

1

1

1

1

2

3

3

4

Passaic Formation

Pennsylvania

Pennsylvania

Pennsylvania

900

1,200

4^00

-

-

-

-

Median, 19 wells

Mean, 19 wells

5

6

6

References:

1 - Rima and others, 1962

2 - Lewis and Spitz, 1987

3 - Barksdale and others, 1958

4 - Vecchioli and Palmer, 1962

5-Sutton, 1984

6 - Longwill and Wood, 1965

19
GROUND-WATER FLOW

Ground water in the study area flows through a complex network of fractures further 

complicated by the presence of nearly impermeable diabase rocks and very permeable fault 

zones. For this study, both a conceptual and a digital model of the flow system were used to 

determine flow-system characteristics and the effects of geologic features on the flow system.

Conceptual Model of Ground-Water Flow

A conceptual model of ground-water flow was developed on the basis of the 

hydrogeologic framework, measured water levels, specific-capacity data, and conclusions of 

previous investigations. A water-level map of the study area was constructed to help 

conceptualize ground-water flow, identify recharge and discharge areas, determine the effects of 

geology on the water-level configuration, and calibrate the digital model (fig. 8).

All of the wells used to draw the water-level map are listed in tables 4a and 4b (at end of 

report). Most of the wells are open to both unconfined and confined water-bearing units. 

Therefore, the water levels in these wells are composite heads that include the effects of heads in 

several water-bearing units. Only 48 wells are less than 75 ft deep-the approximate extent of the 

unconfined system-and only 6 wells are cased to a depth greater than 75 ft. Consequently, 

water-level data in both the unconfined and confined systems are insufficient for drawing 

potentiometric-surface maps. Although the map is not a water-table map or a map of the 

potentiometric surface of the confined system or of any single water-bearing zone, it indicates 

the general trend of water levels and was used in this study as an approximation of the 

configuration of the water-table surface.

Water-level altitudes in wells are controlled primarily by land-surface elevation. The 

water table is a subdued version of the topography; water levels in topographically high areas 

generally are a little deeper below land surface than water levels in lowlying areas. In 

topographically high areas, the measured water levels generally were 25 to 35 ft below land 

surface, whereas water levels in lowlying areas generally were 0 to 10 ft below land surface. In 

areas where few water-level data were available, contours were based on the assumption that 

this water-level trend prevails throughout the study area.

The 544 ground-water levels that were used to draw the map were measured over a period 

of 83 years (1907-89). Consequently, they represent water levels in different seasons and under 

different climatic conditions; however, temporal variability in water levels caused by seasonal 

and long-term climatic fluctuations is assumed to be negligible relative to the spatial variability 

caused by topography. Water-level data (fig. 9) from three wells in the study area indicate that 

the long-term seasonal and climatic variability in water levels is less than 15 ft. At well 210365 in 

the Stony Brook drainage basin, the range in water levels measured from February 1987 through 

September 1994 is 6.8 ft. In the area of this well, the water-table surface slopes about 45 ft/mi. 

Water levels in this well have been measured daily except for an 89-day period in 1988 and a 51- 

day period in 1993. At well 210088 in the Stony Brook drainage basin, the range in water levels 

measured from January 1968 through September 1994 is 17.2 ft. However, the sharp drops in the 

water levels in this well during 1987 and 1992 probably are the result of withdrawals from an 

irrigation well located 800 ft east of this well (Jacobsen and others, 1987, p. 16). Except for these 

sharp drops, the range in water levels during the period of record is only 4.0 ft. In the area of this 

well, the water-table surface slopes about 50 ft/mi. Since 1968, water levels in this well have 

been measured 1 to 12 times per year, except in 1976, when no measurements were made. At

20
40° 

30' ____________74° SO'____________________

1

EXPLANATION 

MUNICIPAL BOROUGHS

STUDY-AREA BOUNDARY AND DRAINAGE-BASIN 

DIVIDES FOR STONY BROOK, BEDEN BROOK, 

(UPSTREAM FROM U.S. ROUTE 206) AND 

JACOBS CREEK

WATER-LEVEL CONTOUR-Shows altitude of water 

levels in partially cased bedrock wells. Dashed where 

approximately located. Contour interval 50 feet. _ 

National Geodetic Vertical Datum of 1929 '

LOCATION OF WELL AT WHICH 

WATER LEVEL WAS MEASURED

74°451 74°40'

40°

251

40° 

201

* "I-N.

 > ~^« l|\?5« 350,:, ,^/iN-

/ I }* -s» __ j i - sk * !» , i ^* "

r\ ~ ....' i-<t ±r> '/.?/ '; l-/<~^

( W ^J .--' '

PN ^L-r e /

40° 

15'

(

/- x- x V 

/ s ^-^ -v- N >/x ' I ^ \ \ ___/ \

C 1 MILE 

C 1 KILOMETER

Figure 8. Prepumping ground-water levels in and near the study area, Stony Brook, 

Beden Brook, and Jacobs Creek drainage basins, west-central New Jersey.

21
230

220 - 210 - Qj 200 

in

HI CO

at OCDHI

LJJ

_ltr HI

190

180170

160

150

140130

i i i i i i i i i i

WELL 210365

V/WVAA

WELL 210289

WELL 210088

I I I I I I I I

1965 1970 1975 1980 

DATE

1985 1990 1995

Figure 9. Hydrographs of water levels in wells in the Stony Brook and Jacobs Creek drainage basins, west-central New Jersey.
well 210289 in the Jacobs Creek drainage basin, the range in water levels measured from 

December 1986 through September 1994 is 10.9 ft. In the area of this well, the water-table surface 

slopes about 60 ft/mi. Water levels in this well have been measured daily except for a 50-day 

and a 60-day period in 1987 and a 200-day period in 1989.

Reported water levels in each well in the study area were analyzed to determine whether 

they represent prepumping conditions. Water levels that were not considered representative of 

prepumping conditions were not used in drawing the water-level map. Only initial water 

levels levels measured at the time each well was constructed were considered potential 

prepumping water levels. The water level in each well was further analyzed to determine 

whether it was affected by nearby pumpage. If the water level in a given well was anomalously 

low relative to levels in nearby wells, and if the nearby wells had been constructed before the 

given well, the water level in the given well was assumed to have been lowered as a result of 

pumpage in the nearby wells. For purposes of this analysis, an anomalously low water level was 

defined as a water level that was more than 15 ft lower than surrounding water levels if no 

corresponding depression in land-surface elevation was present. The 15-ft criterion was chosen 

because differences less than 15 ft could be attributable to seasonal or climatic variability, as 

discussed in the preceding paragraph.

In applying this criterion, it was found that pumpage from domestic wells had lowered 

water levels only within a radius of about 500 ft. This situation occurred where two or more 

wells were installed on the same property and in a housing development where several wells 

were installed within 200 ft of each other. In each of these areas, the water level in the oldest well 

was the highest water level and was considered to be representative of prepumpage conditions. 

The newer wells in these areas were considered to be affected by pumpage. Similarly, it was 

found that only wells less than 4,000 ft from public supply, industrial, and commercial wells 

were affected by pumpage from those wells.

The water levels in nearly all of the 544 wells used to develop the water-level map (fig. 8) 

were measured by personnel from drilling companies at the time the wells were installed. 

Consequently, the conditions under which the measurements were made are unknown. Some of 

the measurements could have been made before the water level in the well stabilized and may, 

therefore, be nonstatic water levels. These water-level data were submitted by drilling 

companies to the New Jersey Department of Environmental Protection in well-completion 

records and later compiled in reports by Kasabach (1966), Vecchioli and Palmer (1962), and 

Widmer (1965) and in the USGS Ground-Water Site Inventory data base. Although some of the 

data probably are erroneous, the water-level map is assumed to adequately represent the water 

table for purposes of developing a conceptual model of ground-water flow.

Water levels in streams also were used in the water-level map. Water levels in streams in 

the study area were assumed to be equal to the water-table altitude under prepumping 

conditions. This assumption was based on base-flow data collected by Jacobsen and others 

(1993, p. 20) at 63 sites in the study area. All measured reaches except one, which is near a 

pumped public supply well, were gaining reaches.

Recharge and Discharge Areas

Ground-water recharge areas, as approximated from the water-level map, are at 

topographically high areas and discharge areas are at streams. In general, ground-water divides 

coincide with, or are slightly offset from, surface-water divides, and water follows short flow

23
paths through the shallow part of the system to the stream nearest the point of recharge. Some 

water does flow in the deep part of the flow system, however, as evidenced by a gradual increase 

in well yields as wells are deepened. The water in the deep part of the flow system is assumed to 

be water that recharges at topographic highs, such as areas underlain by diabase rocks, and then 

flows downward. When this water reaches lowlying areas, it flows upward to the shallow part 

of the flow system and discharges to major streams, such as Stony Brook, Beden Brook, Jacobs 

Creek, and the Delaware River. Hypothetical ground-water flow paths are shown in figure 10.

One area in which a ground-water divide is offset from the surface-water divide is at the 

western border of the study area, near Baldpate Mountain (fig. 8). In this area, the surface-water 

divide is delineated by a topographic high at the western edge of the Jacobs Creek drainage 

basin, but the ground water divide is farther west, at the crest of Baldpate Mountain, an area 

underlain by diabase rocks. The surface-water divide at the edge of the study area is at an 

altitude of about 240 to 260 ft, but the divide at Baldpate Mountain is at about 485 ft. Groundwater recharge at Baldpate Mountain flows east from the mountaintop under the divide at the 

study-area boundary and into the study area.

Anisotropy of Sedimentary Aquifers

Elliptical cones of depression around pumped wells are evidence of anisotropic 

conditions in Newark Basin aquifers. In the study area, for example, an aquifer test conducted 

by Vecchioli and others (1969, p. B155) resulted in 7.6 ft of drawdown 600 ft along strike from the 

pumped well and only 0.7 ft of drawdown 300 ft along dip from the pumped well (fig. 11). 

Similar elliptical cones of depression elsewhere in the Newark Basin have been described by 

Vecchioli (1967), Herpers and Barksdale (1951, p. 29-31), and Longwill and Wood (1965).

The anisotropic conditions observed in Newark Basin aquifers are a direct result of 

dipping interlayered water-bearing units and confining units. In the water-bearing units, water 

can flow long distances in the direction of the strike of the bedding without encountering 

barriers (fig. 6a). Water cannot flow long distances in the direction of dip, however, because each 

water-bearing unit contains fewer interconnected fractures as it deepens with dip, and at a depth 

of about 500 ft below land surface, all fractures are closed. Therefore, hydraulic conductivity is 

greater in the strike direction than in the dip direction.

In anisotropic systems, ground-water-flow directions are not necessarily perpendicular 

to lines of equal hydraulic head, as they would be in isotropic systems; rather, they are skewed in 

the direction of the highest hydraulic conductivity. Therefore, in the study area, lines drawn 

perpendicular to water-level contours do not accurately define ground-water flow paths except 

where they are parallel to the strike of the bedding. Elsewhere, ground-water flow paths are 

skewed away from those perpendicular lines toward the strike direction.

Effect of Diabase Rocks

Fractures are far more sparse in diabase rocks than in any of the other rocks in the study 

area. Low specific capacity per foot of open hole for wells in the diabase reflects this sparsity of 

fractures and is indicative of low hydraulic conductivity. Consequently, diabase rocks impede 

ground-water flow.

24
sw NE

ro

EXPLANATION

WEATHERED ROCKS-Unconsolidated sediments, 

extensively fractured rock layers, and sparsely fractured rock layers that are more permeable than the underlying rock layers

EXTENSIVELY FRACTURED ROCK LAYER 

(Water-bearing unit)

SPARSELY FRACTURED ROCK LAYER 

(Confining unit)

HYPOTHETICAL GROUND-WATER 

FLOW PATH

Unconfined 

zone

Confined 

zone

NOT TO SCALE VERTICAL SCALE GREATLY EXAGGERATED

Figure 10. Hypothetical ground-water flow paths in the study area, Stony Brook, 

Beden Brook, and Jacobs Creek drainage basins, west-central New Jersey. 

(Section is oriented parallel to the strike of rock layers.)
0 200 FEET

I ' f ' I

0 60 METERS

0.8

22

.0.7

0.7

EXPLANATION

 5 LINE OF EQUAL DRAWDOWN-lnterval 4 feet 

2^/ STRIKE AND DIP OF BEDDING 

.7.8 WELL LOCATION AND DRAWDOWN, IN FEET

NEW YORK

NEW JERSEY

Aquifer-test site

0 10 20 MILES0 10 20 KILOMETERS

Figure 11. Drawdown at end of aquifer test in Stony Brook drainage basin, west-central New Jersey. (Modified from Vecchioli and others, 1969)
Source of Water to Wells

Water flowing to a pumped well is derived primarily from the water-bearing units that 

are intersected by the well and secondarily from other water-bearing units by leakage through 

the confining units. If one or more of the water-bearing beds intersected by a well is connected to 

an updip surface-water body, the well probably derives a significant part of its flow from the 

stream by induced infiltration. Vecchioli and Palmer (1962, p. 32-34) found that the average yield 

of wells near surface water is about twice that of wells that are not near surface water.

Stream-discharge data indicate the possibility of induced infiltration near pumped wells 

along a reach of Stony Brook. Base-flow measurements made during August and November 

1987 (Jacobsen and others, 1993, table 4) indicate a loss of 0.16 ft3 /s between measurement sites 

01400920 and 01400940 (fig. 17, farther on) in August and a loss of 0.23 ftVs along the same reach 

in November. Although the apparent decrease in discharge along the reach could be due to the 

measurement uncertainty (R.D. Schopp, U.S. Geological Survey, oral commun., 1991), it is also 

possible that the loss resulted from pumpage of nearby Pennington Borough public supply wells 

(fig. 18, farther on).

Simulation of Ground-Water Flow

A digital model that simulates steady-state, prepumping conditions was used to test 

hypotheses concerning the effects of geologic features on ground-water flow in the study area. 

These features include the decrease in the density of fractures with depth, the anisotropy caused 

by dipping water-bearing rock strata, the nearly impermeable diabase sills, and the relatively 

permeable Hopewell Fault. The model was developed with sufficient detail to simulate these 

features, but not all of the local complexities of the hydrogeologic framework are simulated in 

the model. Consequently, the model was not designed as a tool for detailed quantification of flow 

at discrete points or for development of water policies and regulations for any part of the study 

area.

Description of Digital Model

A three-dimensional, finite-difference Fortran code (MODFLOW) developed by 

McDonald and Harbaugh (1988) was used for the simulation. The code was revised to allow for 

variable anisotropy ratios within each model layer. The anisotropy ratio is the hydraulic 

conductivity along model columns (the dip direction) divided by the hydraulic conductivity 

along model rows (the strike direction).

Grid orientation and discretization

The model grid (fig. 12) was oriented so that the model rows coincided with the strike of 

the geologic units to allow simulation of the difference in horizontal hydraulic conductivity in 

the strike and dip directions. The model was discretized into 122 rows, 150 columns, and 2 

layers. Of the 36,600 model cells, 19,838 are active. The inactive cells are outside the study area. 

Each model cell is 500 ft long and 500 ft wide. This horizontal discretization scheme allowed for 

adequate representation of each zone of different hydraulic conductivity. Each zone is at least 

two cells wide, and most are five or more cells wide.

The decrease in conductivity with depth was represented in the model by dividing the 

grid into two layers. The vertical discretization is based on the results of the analysis of specificcapacity data shown in table 2. The specific-capacity data indicate that specific capacity

27
EXPLANATION

o Model cell

 Model cell containing a stream 

simulated as a specific-head 

boundary with a semipermeable 

streambed

B Model cell containg a stream 

simulated as a flux boundary

74°45'

74°50'

40°25

40°20'

Study-area boundary

3 MILES

T I I I 

0123 KILOMETERS

Figure 12. Discretization and orientation of digital-model grid and locations of 

model cells containing streams, Stony Brook, Beden Brook, and Jacobs Creek 

drainage basins, west-central New Jersey.

28
decreases with depth below land surface, and that the largest decrease in specific capacity occurs 

at about 75 ft below land surface. Accordingly, model layer 1 is generally less than 75 ft thick and 

consists of the saturated portion of the interval between land surface and 75 ft below land 

surface. Model layer 2 consists of the depth interval from 76 ft to 500 ft below land surface.

Layer 1 was simulated as an unconfined aquifer and represents the part of the aquifer 

system in which fractures are much more abundant and interconnected than in the lower part of 

the system (figs. 6a and 6b). Layer 2 was simulated as a confined aquifer and represents the part 

of the aquifer system where water-bearing units are confined by interlayered confining units 

(figs. 6a and 6b). Each of the model layers spans several water-bearing and confining units.

In areas where land-surface elevation decreases abruptly, the bottom of model layer 1 is 

deeper than 75 ft below land surface. These areas are found at the edges of diabase sills, at the 

escarpment of the Hopewell Fault (fig. 8), and in the area northwest of the escarpment where 

streams have incised deeply into the rocks of the Stockton Formation. In these areas, the water 

table is farther below land surface than in other areas. The bottom of layer 1 was set deeper than 

75 ft below land surface in these areas so that the saturated thickness of layer 1 would be 

approximately constant throughout the study area. The altitude of the bottom of layer 1 for each 

model cell in these areas was set at the average altitude of the bottoms of the cells immediately 

upslope and downslope from the cell. The bottom of layer 1 reaches its maximum depth below 

land surface (208 ft) in a model cell located near the eastern edge of the diabase sill known as 

Pennington Mountain (fig. 4). The bottom of layer 1 is more than 75 ft below land surface in only 

8 percent of the model area, and more than 100 ft below land surface in only 2 percent of the area.

The bottom of model layer 2 is 500 ft below land surface throughout the model. The 

depth of 500 ft was chosen on the basis of reports that Newark Basin rocks deeper than 500 ft 

below land surface yield little or no water. A schematic representation of model layers and 

boundary conditions is shown in figure 13.

Boundary conditions

Model boundaries coincide with hydrologic boundaries. Except for the upper surface, 

most boundaries are no-flow boundaries.

Upper boundary and simulation of surface water. The upper boundary was simulated as a 

free surface to represent the water table with specified flux applied to represent areal recharge. 

The method by which the rate of areal recharge was determined is discussed in the section "Areal 

recharge," farther on.

Surface water was simulated in two ways. Except for the uppermost reaches, the three 

major streams-Stony Brook, Beden Brook, and Jacobs Creek-were simulated as headdependent-flux boundaries by using the "River module" of the MODFLOW model. In this 

module, the head in the stream is specified, and water flows between the aquifer and the stream 

through the streambed. The rate of flow between the aquifer and the stream is controlled by the 

head difference between the stream and the aquifer, the hydraulic conductivity and thickness of 

the streambed, and the length and width of the stream. The method by which these parameters 

were estimated is described in the section "Streambed hydraulic conductance," farther on.

29
FREE-SURFACE (WATER-TABLE) BOUNDARY 

NO-FLOW OR WITH FLUX (AREAL RECHARGE) 

SPECIFIED-FLUX 

BOUNDARY

0

HEAD-DEPENDENTFLUX AND 

SPECIFIED-FLUX 

BOUNDARIES 

(STREAMS)

NO-FLOW 

BOUNDARY 500

Z 

O

CC 

O

LL

O

<

CO 

CO

<

Q.

\

Z 

O

-I--

CC 

O

LL

CD

Z 

O

O 

O

\

Z 

O

CC 

O 

u.

O 

O

hco

NO-FLOW OR

SPECIFIED-FLUX

BOUNDARY

LAYER 1

LAYER 2

-NO-FLOW 

BOUNDARY

NO-FLOW BOUNDARY

Figure 13. Schematic representation of model boundary conditions, layers, 

and zones of different hydraulic conductivity, Stony Brook, Beden Brook, 

and Jacobs Creek drainage basins, west-central New Jersey.

30
The tributaries to and the uppermost reaches of Stony Brook, Beden Brook, and Jacobs 

Creek were modeled as specified-flux boundaries rather than head-dependent-flux boundaries. 

This was done because the model was found to be very sensitive to specified heads in streams, 

and the water level in these stream reaches falls as much as 20 ft over the length of a model cell. 

Therefore the average elevation of these stream reaches within a model cell is a poor 

representation of the stream elevation at all points in the cell. The method by which the flux to 

each model cell was determined is discussed in the section "Base flow and direct runoff," farther 

on.

The study area contains many lakes and ponds, none of which was assigned a boundary 

condition because all lakes and ponds are artificial and do not represent natural or prestressed 

conditions. Most of the ponds and small lakes were dug for irrigation or aesthetic purposes, and 

all of the larger lakes are dammed reaches of streams.

Lateral boundaries.-Lateral model boundaries coincide with the study-area boundary, 

which was defined by surface-water divides. In all but two areas, ground-water divides coincide 

with these surface-water divides, and no-flow cells were used in the model to represent the 

boundary. The two areas where ground-water divides do not coincide with surface-water 

divides are near Baldpate and Sourland Mountains (fig. 8). Water levels near Baldpate Mountain 

indicate that ground water flows from Baldpate Mountain eastward into the study area. There, 

layer 1 was simulated as a specified-flux boundary. The flux was placed only in layer 1 because 

Baldpate Mountain is just outside the model area. Consequently, the flow path from the 

mountaintop to the study area is relatively short and was assumed to be wholly in layer 1. To 

test the hypothesis that this flux occurs only in layer 1, the model was tested with some of the 

flux applied to layer 2. The model best simulated heads and base flow when flux was applied 

only to layer 1. The total amount of flow crossing this flux boundary was set at 104,500 ft /d 

distributed among 10 model cells at the model boundary. The method by which the amount of 

flux was determined is described in the section "Ground-water flow to and from adjoining 

drainage basins," farther on.

Flux also was applied at the model boundary in the area south of Sourland Mountain and 

north of Rock Brook (fig. 8) to simulate water flowing from Sourland Mountain into the study 

area. Sourland Mountain, which is underlain by diabase, extends northeast beyond the study 

area. Water that recharges the part of Sourland Mountain lying outside the study area probably 

flows southeast or south from the mountaintop toward the escarpment of the Hopewell Fault. 

After reaching the fault, which is much more permeable than the surrounding rocks, ground 

water probably flows along the fault southwest into the study area. The total amount of flow 

simulated crossing this flux boundary is 27,300 ft3/d distributed across five model cells in 

layer 1.

Ground water in the deep part of the system may flow out of the study area and 

eventually discharge to the Delaware River. No flux boundaries were applied to the model to 

simulate this type of flow, however. The model was tested with various amounts of flux leaving 

the western border of the model through layer 2, but the matches between measured and 

simulated heads and measured and simulated base flow to streams were not improved by this 

flux. Also, because no wells that are open only to layer 2 are located near the model boundary, 

no field evidence exists of flow out of the study area in the deep part of the aquifer system.

31
Lower boundary. The lower model boundary represents the depth below land surface at 

which ground-water flow is negligible. This depth was assumed to be 500 ft. The lower 

boundary was simulated as a no-flow boundary.

Calibration of Digital Model

All values of hydraulic properties initially used in the model were estimates. During 

model calibration, the initial estimates of horizontal hydraulic conductivity, anisotropy ratio, 

vertical conductance between model layers, and streambed conductance were adjusted until the 

model was an acceptable representation of the conceptual model. During calibration, it was 

assumed that no-flow boundaries adequately represent the actual flow system at the bottom of 

layer 2 and at the model perimeter except in the two small areas described in the preceding 

section, and no additional adjustments were made to the no-flow boundaries.

Determining the acceptability of the match between simulated and conceptual groundwater flow system is subjective. Although an attempt was made to match measured 

prepumping water levels and estimated base-flow rates as closely as possible, an exact match 

was not possible because many of the small-scale complexities of the geologic framework are not 

represented in the model. For example, in the model, hydraulic conductivity is constant over 

each outcropping geologic unit, whereas the actual conductivity probably varies because the 

spacing of interconnected fractures varies. Consequently, measured water levels in areas where 

the spacing between fractures differs from the average spacing will be outside the range of 

simulated water levels.

Water levels

Two sets of data were used to compare measured and simulated water levels. One data 

set consists of water levels measured by the USGS in October 1987, in 65 wells in the study area. 

In this report, this data set is referred to as the "U.S. Geological Survey water-level data." During 

model calibration, each of these 65 water levels was compared to model-generated heads (table 

5). Water levels in this data set are known to be accurate to within 0.01 ft because the methods 

used and the conditions under which the measurements were made are documented (Jacobsen 

and others, 1993, p. 8). Seasonal and long-term variability in water levels in this data set are 

minimal because all the water levels were measured within a 21-day period. During this period, 

2.05 inches of precipitation fell in the study area, but the water level in wells 210088 and 210365 

(fig. 4) rose only 1.59 ft and 0.67 ft, respectively. In addition, the levels in all 65 wells could be 

assumed to be static levels and representative of unstressed conditions because none of the wells 

are within 4,000 ft of industrial, commercial, or public supply wells. In addition, none of the 

measured wells or nearby domestic wells had been pumped for at least 1 hour prior to 

measurement. Well locations and the difference between measured and simulated water levels 

are shown in figure 14.

The other data set consists of the 544 water levels used to draw the water-level map 

(fig. 8). In this report, this data set is referred to as "well-completion-record data." As described 

in the section "Conceptual model of ground-water flow," the accuracy of individual water-level 

measurements in this data set and the conditions under which the measurements were made is 

unknown. Therefore, these water levels were not compared individually with model-generated 

heads for model calibration. Instead, the water-level map (fig. 8) was compared with a contour 

map of model-generated composite heads (fig. 15b) to compare measured and simulated water 

levels throughout the study area, including areas where data are sparse (dashed contours on 

figure 8). Figure 15a includes the same water- level contours as figure 8 drawn to the same scale 

as figure 15b so that the two sets of water-level contours can be compared directly.

32
Brook, and Jacobs Creek drainage basins.

New Jersey

well number

350053

350058

350057

210333

210341

350050

210329

350028

350055

210328

210355

350059

210297

210327

210332

190242

350049

210353

210326

210354

350052

210340

210336

350054

210298

210321

210352

210301

210295

210337

210300

190241

350060

210331

210357

210324

210356

210325

210292

210347

350048

350061

210296

210350

210349

210313

350056

350041

350051

Measured

water level

(feet above

sea level)

163

170

152

248

176

86

167

91

72

114

157

66

109

106

172

285

86

184

111

136

105

144

139

110

165

138

153

125

130

128

205

297

164

169

127

61

161

209

288

185

414

257

384

180

184

294

392

353

297

west-central New Jersev

Simulated

water level

(feet above

sea level)

Passaic Formation

125

136

122

224

162

74

162

86

68

111

154

68

112

109

176

290

92

191

119

145

115

155

151

122

179

152

167

144

154

152

Lockatong Formation

186

282

151

157

116

54

156

209

300

197

428

272

402

201

208

320

440

408

414

Simulated

water level

minus

measured

water level

(feet)

-38

-34

-30

-24

-14

-12

-5

-5

-4

-3

-3

2

3

3

4

5

6

7

8

9

10

11

12

12

14

14

14

19

24

24

-19

-15

-13

-12

-11

-7

-5

0

12

12

14

16

18

21

25

26

48

55

117

Water-levelmeasurement

date

10-15-87

10-14-87

10-14-87

10-05-87

10-23-87

10-06-87

10-05-87

10-14-87

10-03-87

10-05-87

10-05-87

10-14-87

10-03-87

10-05-87

10-05-87

10-06-87

10-14-87

10-06-87

10-05-87

10-05-87

10-15-87

10-05-87

10-05-87

10-15-87

10-14-87

10-05-87

10-05-87

10-05-87

10-05-87

10-05-87

10-05-87

10-06-87

10-14-87

10-06-87

10-05-87

10-05-87

10-05-87

10-06-87

10-06-87

10-05-87

10-14-87

10-14-87

10-05-87

10-06-87

10-06-87

10-06-87

10-15-87

10-15-87

10-14-87

33
Table 5. Measured and simulated water levels in selected wells in the study area. Stony Brook. Bedcn 

Brook, and Jacobs Creek drainage basins, west-central New Jersey Continued

New Jersey 

well number

Measured

water level

(feet above 

sea level)

Simulated

water level

(feet above 

sea level)

Simulated

water level

minus

measured

water level 

(feet)

Water-levelmeasurement 

date

210315

190239

210345

210346

210314

210334

210338

210302

210335

190240

210294

210344

210303

210265

210316

350047

323

370

289

254

207

238

262

321

280

421

Diabase rocks

272

339

258

228

188

225

261

325

284

460

-51

-31

-31

-26

-19

-13

-1

4

4

39

189 316 127 

Stockton Formation north of the Hopewell Fault

366 

314 

327 

3S6 

150

328

313

342

410

222

-38 

-1 

15 

24 

72

10-14-87 

10-06-87 

10-05-87 

10-05-87 

10-05-87

10-05-87 

10-05-87 

10-15-87 

10-05-87 

10-05-87

10-05-87

10-05-87 

10-05-87 

10-15-88 

10-15-87 

10-14-87

34
EXPLANATION

40°20'

Diabase

Passaic Formation of Olsen (1980).

Contains strata (JTrpg) similar to the

rocks in the underlying Lockatong Formation

Lockatong Formation. Contains strata 

(Trlr) similar to the rocks in the overlying 

Passaic Formation

Line of contact between 

geologic units

16 Well location and 

 measured minus simulated 

water level, in feet

Stockton Formation

74°45'

Trl

74°50'

40°25'

Study-area boundary

3 MILES

r I I I 

0123 KILOMETERS

Figure 14. Location of water-level-measurement sites and difference between measured 

and simulated water levels, Stony Brook, Beden Brook, and Jacobs Creek drainage 

basins, west-central New Jersey.

35
-250-----

EXPLANATION

INTERPRETED WATER-LEVEL CONTOUR-- 

Shows altitude of water level, in feet. 

Dashed where approximate. Contour 

interval 50 feet. Datum is sea level

STREAM

SURFACE-WATER DRAINAGE-BASIN BOUNDARY

74°45'

40°20'

74°50'

40°25

Study-area boundary

3 MILES

M I T

0123 KILOMETERS

Figure 15a. Interpreted prepumping water levels in the study area Stony Brook, 

Beden Brook, and Jacobs Creek drainage basins, west-central New Jersey.

36
-250-----

EXPLANATION

SIMULATED WATER-LEVEL CpNTOUR-- 

Shows altitude of water level, in feet. 

Dashed where approximate. Contour 

interval 50 feet. Datum is sea level

STREAM

SURFACE-WATER DRAINAGE-BASIN BOUNDARY

74°45'

40°20'

74°50'

Study-area boundary

3 MILES

0123 KILOMETERS

Figure 15b. Simulated prepumping water levels in the study area Stony Brook, 

Beden Brook, and Jacobs Creek drainage basins, west-central New Jersey.

37
To compare simulated heads in the two model layers to measured composite water levels, 

the simulated heads for layers 1 and 2 at each model-cell location were converted into a 

composite head. The following relation, described by Hearne (1985, p. 11), was used for the 

conversion:

b2K2

where hw = the composite simulated hydraulic head in the well; 

Jij = the simulated hydraulic head in model layer 1; 

h2 = the simulated hydraulic head in model layer 2;

b l - the saturated thickness of model layer 1, calculated by subtracting the altitude of the 

bottom of the layer from the simulated head;

b2 = 83 ft the average length of well opening in model layer 2. This equals the average 

depth of all domestic 6-inch-diameter wells in the study area (158 ft) minus the 

average depth below land surface of the top of model layer 2 (75 ft);

JCj = the hydraulic conductivity of model layer 1 in the strike direction; and 

K2 = the hydraulic conductivity of model layer 2 in the strike direction.

That is, the hydraulic head in the well is the weighted average of the hydraulic heads in each of 

the layers with which the well is in hydraulic connection. The weighting factor is the product of 

the thickness and the horizontal hydraulic conductivity of the layer.

For wells that are 75 ft deep or less, the measured water level was compared to the 

simulated head in layer 1 rather than to the composite head, and for wells that are cased from 

land surface down to at least 75 ft, the measured water level was compared to the simulated 

head in layer 2.

U.S. Geological Survey water-level data. For this data set, the model was considered 

adequately calibrated when measured water levels were simulated within the following limits:

-Within 25 ft in areas of low relief (about 100 ft). Low relief is found in areas underlain by 

the Passaic Formation and in the area underlain by the Stockton Formation at the 

southern boundary of the study area.

-Within 30 ft in areas underlain by the Lockatong Formation, where topographic relief is 

moderate (about 150 ft).

-Within 40 ft in areas of high topographic relief (about 200 ft). High relief is found in areas 

underlain by diabase rocks, at the escarpment of the Hopewell Fault, and in the area 

underlain by the Stockton Formation northwest of the fault, where streams are 

deeply incised.

38
A more rigorous calibration criterion was used in areas of low topographic relief than in 

areas of high topographic relief because areas of low topographic relief are also areas of low 

spatial variability in water levels as a result of the relation between the water table and 

topography. In areas of low, moderate, and high topographic relief, water levels vary about 5 to 

20 ft, about 10 to 40 ft, and about 40 to 100 ft, respectively, within individual model cells, whereas 

the digital model simulated only a single average head in each model cell.

Because actual water levels within a model cell can vary as much as 100 ft, the actual 

water level at various points in the cell can differ significantly from the average head in the cell, 

especially at the cell edges. For this reason, the location within a cell of each water-level 

measurement was determined, and the simulated water level for each site was estimated by 

linear interpolation between simulated water levels in adjacent cells. Even with these 

interpolated water levels, however, the model cannot adequately simulate water levels in area of 

high topographic relief, especially where the change in water levels is not linear.

The measured and simulated water levels in this water-level data set are listed in table 5. 

Composite simulated heads in 27 of the 30 wells in the Passaic Formation were within 25 ft of the 

measured heads. None of the 65 wells in which water levels were measured in October 1987 was 

in the part of the Stockton Formation that crops out south of the Hopewell Fault, so no direct 

comparisons can be made between measured and simulated water levels in this area. For wells 

in the Lockatong Formation, 16 of the 19 simulated water levels were within 30 ft of the 

measured water level. For wells in the Stockton Formation north of the Hopewell Fault and 

wells in the diabase rocks, 13 of the 16 simulated water levels were within 40 ft of the measured 

water level.

Well-completion-record data. The map of contoured water levels from the wellcompletion-record data set (fig. 15a) compared well with the map of contoured composite 

model-generated composite heads (fig. 15b) in most parts of the study area. Poor agreement was 

obtained, however, in the northeastern part of the study area, which is underlain mostly by 

diabase rocks. Water levels there range from about 330 to 550 ft (fig. I5a), but simulated water 

levels range from 450 to 750 ft (fig. 15b). Although water-level data in the area are sparse, and 

the interpreted water levels are approximate, actual water levels in this area most likely are less 

than 570 ft the highest land-surface elevation in the area because it is doubtful that wells in this 

area are flowing. The high simulated water levels could be caused by one of several factors. For 

example, a uniform recharge rate was applied to the entire diabase sill in this area; however, the 

rate of recharge to the crest of the sill may be lower than the rate to other parts of the sill. Also, 

some water that recharges at the ridge of the sill near the northern boundary of the model may 

flow north out of the model area.

The composite simulated heads in streams (fig. 15b) are higher than the stream stage (fig. 

15a) in many parts of the study area, partly as a result of a difference in the method used to 

determine water levels at stream locations for the two maps. The composite heads in the aquifer 

at stream locations in figure 15a are equal to stream stage. The water levels at stream locations in 

figure 15b are the average composite heads in the aquifer for the entire model cell in which the 

stream is located. In the model, because all of the streams in the study area are assumed to be 

gaining under prepumping conditions, the water level in the aquifer surrounding the stream is 

higher than the stream level. Consequently, the average head in model cells containing streams 

is higher than the actual stream level.

39
Base flow

The model was considered adequately calibrated with respect to base flow if the total 

simulated base flow in the part of the Stony Brook drainage basin upstream from streamflowgaging station 01401000 (fig. 17, farther on) was within 5 percent of the estimated average 

prepumping base flow, and if the total simulated base flows for the Beden Brook and Jacobs 

Creek drainage basins (ungaged basins) were within 15 percent of the estimated average baseflow rates. The calibration criterion for the gaged basin was more stringent than for the ungaged 

basins because the estimate of average-annual base flow is more accurate for gaged basins than 

for ungaged basins.

The estimated average prepumping base flows for the Stony Brook (upstream of the 

streamflow-gaging station), Beden Brook, and Jacobs Creek drainage basins are 2,280,000, 

1,800,000, and 874,000 ftVd, respectively. The methods used to estimate base flow are described 

in the "Base flow and direct runoff section (farther on).

Simulated total base flows for the Stony Brook (upstream from the streamflow-gaging 

station), Beden Brook, and Jacobs Creek drainage basins are 2,320,000,1,590,000, and 

789,000 ftVd, respectively. The simulated flow for each basin was determined by use of a 

computer program (ZONEBUDGET) that calculates subregional water budgets from cell-by-cell 

flow in the model (Harbaugh, 1990). For each basin, total simulated base flow was assumed to 

be the sum of the flow to streams simulated as constant-flux boundaries ("Well module" of 

MODFLOW) and the flow to streams simulated as head-dependent-flux boundaries ("River 

module" of MODFLOW) minus the flow from streams to the aquifer at head-dependent-flux 

boundaries.

For the part of the Stony Brook drainage basin upstream from the streamflow-gaging 

station, the simulated base flow is 1.75 percent higher than the estimated average prepumping 

base flow. For the Beden Brook and Jacobs Creek Basins, the simulated base flows are 11.7 and 

9.73 percent lower, respectively, than the estimated average prepumping base flows.

Limitations of Digital Model

Because the model necessarily is a simplified representation of the ground-water-flow 

system, its discretization limits its ability to simulate flow accurately. The vertical discretization 

of the model, in which two layers are used to represent the flow system, does not address the 

intricacy of the hydrologic framework. Ideally, each water-bearing unit would be represented by 

a separate model layer, but this is not feasible in a model that represents an area as large as the 

study area. First, the location and configuration of each water-bearing unit is not known and 

could be known only if many exploratory holes were drilled and logged. Second, far too many 

water-bearing units (approximately 125) are present in the study area for each to be modeled as a 

separate layer. Modeling this many units is not feasible because of the time required for each 

model run made during calibration and analysis.

In this model, the effect of the discontinuity of water-bearing units in the dip direction is 

simulated by assigning a lower hydraulic conductivity in the dip direction than in the strike 

direction. This representation of the flow system is adequate on a large scale but not in 

individual water-bearing units. For a local, or site-specific, problem, where the area of interest is 

less than about 0.5 mi2, precise determination of flow paths within and between individual

40
water-bearing units is necessary. For the purposes of this study, however analysis of the effects 

of relatively large-scale features on ground-water flow-the model is adequate.

The other complexity this model does not address is the variability of fracture spacing 

within each geologic unit. This limitation also precludes use of the model for site-specific 

problems but does not detract from its usefulness as a tool for studying the effects of large-scale 

geologic features on ground-water flow.

Prepumpinq Water Budgets

Ground-water budgets simulated with the digital model for all three surface-water 

drainage basins in the study area are shown in figure 16. The budget for the Stony Brook 

drainage basin pertains to the part of the basin upstream from streamflow-gaging station 

01401000, which is about 2 miles upstream of the point at which Stony Brook crosses the studyarea boundary (fig. 17). This gaging station has provided a continuous record of streamflow 

since October 1953. The part of the basin upstream from the gaging station consists of 44.5 mi2; 

the downstream part is 3.5 mi .

Initial estimates of base flow and areal recharge were made on the basis of records of 

streamflow, precipitation rates, and air temperature, and reported pumpage and sewage-outflow 

rates. Initial estimates of ground-water flow into the study area were made on the basis of the 

estimated amount of recharge to and direct runoff from the source areas of these flows. These 

initial estimates were adjusted within reasonable ranges during model calibration. The methods 

by which initial estimates were made and adjustments during model calibration are discussed in 

the following sections.

Base Flow and Direct Runoff

Base-flow rates are strongly affected by geologic and topographic features. The total base 

flow per unit area is significantly different among the three basins in the study area; the 

differences are attributable mostly to the areal distribution of diabase rocks.

Initial estimates

The initial estimate of average annual base flow in the Stony Brook drainage basin was 

based on streamflow at streamflow-gaging station 01401000. For the other two basins, which are 

not gaged, the estimates were made by developing correlations between flow at the gaged 

station and flow at the ungaged stations.

Stony Brook drainage basin. The initial estimate of base flow in the part of the Stony 

Brook drainage basin upstream from streamflow-gaging station 01401000 was made by using the 

streamflow-partitioning method described by Rutledge (1992), in which daily base flow is 

separated from direct runoff on the basis of daily changes in streamflow Estimated average base 

flow and direct runoff in the Stony Brook Basin are 8.08 in/yr (2,290,000 ft3 /d) and 11.8 in/yr 

(3,340,000 ft3 /d), respectively, for the period January 1954 through December 1991.

In the Stony Brook basin, a relatively high portion of streamflow is derived from direct 

runoff. For comparison, direct runoff to streams in the Coastal Plain of New Jersey is negligible 

(Martin, 1990, p. 59). The high rate of direct runoff in the study area is caused by both lithology 

and topographic features. The soils in the study area are rich in silt and clay, which impede 

infiltration of precipitation (Holman and others, 1954, p. 39,42,45), and the sloping topography 

enhances runoff.

41
(a)

GROUND-WATER SYSTEM

Ail values are in inches per year Budget deficit = 0.84 percent

(b)

GROUND-WATER SYSTEM

All values are in inches per year Budget deficit = 1.33 percent

(c)

GROUND-WATER SYSTEM

All values are in inches per year Budget deficit = 0.96 percent

Figure 16. Simulated average-annual prepumping water budgets, 1954-91: 

(a) Stony Brook drainage basin, west-central New Jersey, upstream from 

streamflow-gaging station 01401000, (b) Beden Brook drainage basin, 

west-central New Jersey, (c) Jacobs Creek drainage basin, west-central 

New Jersey.

42
EXPLANATION

01400920 Base-flow measurement site and 

A station number

Drainage-basin boundary

74°45'

74°50'

01401600

40°20'

01402800 0123 KILOMETERS

Figure 17. Base-flow-measurement sites, Stony Brook, Beden Brook, and 

Jacobs Creek drainage basins, west-central New Jersey.

43
The estimate of base flow derived from 1954-91 streamflow records was assumed to include 

sewage. After subtracting the 0.158 in/yr (44,700 ftVd) of average-annual sewage outflow 

introduced into streams in the basin, the estimated base flow for Stony Brook is 7.92 in/yr 

(2,240,000 ft3 /d). Prepumping base flow was assumed equal to 1954-91 average annual base flow 

plus ground-water pumpage, as discussed in the section on ground-water pumpage, below. The 

estimated prepumping base flow in the Stony Brook drainage basin is 8.06 in/yr 

(2,280,000 ft3 /d).

Beden Brook and Tacobs Creek drainage basins.-Because continuous records of 

streamflow are unavailable for the Beden Brook and Jacobs Creek Basins, average-annual base 

flow was estimated on the basis of several discharge measurements made under base-flow 

conditions during 1954-91. These measurements were made at station 01401600, which is located 

where Beden Brook crosses the study-area boundary, and station 01402800, at the mouth of 

Jacobs Creek (fig. 17). To estimate the 38-year average base flow at the two ungaged stations, 

statistical correlations between discharge at each of the ungaged stations-27 measurements at 

the Beden Brook station and 14 at the Jacobs Creek station-and discharge at the Stony Brook 

station were developed. The estimated average base flow, after subtracting sewage outflow, is 

10.1 in/yr (1,770,000 ftVd) in the Beden Brook Basin and 10.1 in/yr (855,000 ftVd) in the Jacobs 

Creek Basin. Prepumping base flow was 10.2 in/yr (1,800,000 ftVd) in the Beden Brook 

drainage basin and 10.3 in/yr (874,000 ftVd) in the Jacobs Creek drainage basin.

The estimated base-flow rates per unit area for the Beden Brook and Jacobs Creek Basins 

are higher than that of the Stony Brook Basin as a result of flow into the basins from 

topographically high areas underlain by diabase (Baldpate and Sourland Mountains) outside the 

study area.

Effect of anisotrony

Because anisotropy affects ground-water-flow directions, it affects flow paths to streams 

and the size and shape of the recharge area that contributes water to each stream. Lewis (1992) 

found that streams in the study area that are aligned along the dip of the rock layers receive some 

of the ground water that would have discharged to nearby streams aligned along strike if the 

system were isotropic.

Under isotropic, unconfined conditions, the area that contributes ground water to a 

stream is approximately equal to the stream's surface-water drainage area. Under the 

anisotropic conditions in the study area, however, ground-water flow paths are skewed toward 

the strike direction. For example, where a strike-aligned tributary flows into a dip-aligned 

stream, some of the water that would, under isotropic conditions, flow to the tributary instead 

flows along strike into the dip-aligned stream. Therefore, the area that contributes ground water 

to the dip-aligned stream is larger than the stream's surface-water drainage area, and the area 

that contributes ground water to a strike-aligned tributary is smaller than its surface-water 

drainage area. Consequently, in the study area, the amount of base flow per unit surface-water 

drainage area is larger for dip-aligned streams than for strike-aligned streams.

An analysis of simulated base flow in reaches of Stony Brook, Beden Brook, and Jacobs 

Creek that were simulated as head-dependent-flux boundaries illustrates the preferential 

discharge of ground water to dip-aligned stream reaches. Strike-aligned reaches comprised a 

total stream length of 61,300 ft and 142 model cells. Total base flow to these reaches was 530,000 

ft3 /d, which is equal to 8.65 ftVd per foot of stream length or 3,730 ftVd per model cell. Dip-
aligned reaches comprise a total stream length of 44,600 ft and 95 model cells. Total base flow to 

these reaches was 683,000 ft3 /d, which is equal to 15.3 ft3 /d per foot of stream length or 

7,190 ft3 /d per model cell. Therefore, dip-aligned stream reaches receive 1.77 times as much base 

flow per unit length as strike-aligned reaches, and 1.93 times as much base flow per model cell as 

strike-aligned reaches.

Base-flow rates In the digital model

The initial estimates of total average base flow in each drainage basin were used to 

determine of the initial flux rate applied to each stream cell that was simulated as a specified-flux 

boundary (fig. 12). For each drainage basin, the specified flux in each cell initially was estimated 

by distributing the total estimated base flow in the basin among all the stream cells in the basin 

on the basis of stream length. For each cell simulated as a specified-flux boundary, these initial 

estimates of base flow were adjusted to reflect variations in base flow caused by geologic 

features. For tributaries underlain by diabase rocks, the initial estimate of base flow was 

multiplied by 0.4 to reflect lower amounts of recharge in these areas. For tributaries aligned 

along the strike of the rock layers, the initial estimate of flux was multiplied by 0.8. For 

tributaries aligned along the dip, the initial estimate was multiplied by 1.2.

The total simulated prepumping base flow, including all stream cells simulated as 

specified-flux boundaries and as head-dependent-flux boundaries, is 2320,000 ftVd (8.19 in/yr) 

in the part of the Stony Brook Basin upstream from the streamflow-gaging station, 

1,590,000 ftVd (9.06 in/yr) for the Beden Brook basin, and 789,000 ft5/d (9.32 in/yr) in the Jacobs 

Creek Basin. The total simulated base flow in the part of the Stony Brook drainage basin 

downstream from the gaging station is 234,000 ft3 /d (10.4 in/yr).

In the Stony Brook drainage basin upstream from the streamflow-gaging station, 

1,140,000 ft3 /d was simulated as head-dependent flux and 1,180,000 ftVd was simulated as 

specified flux. In the Beden Brook drainage basin, a total of 352,000 ft3 /d of base flow was 

simulated as head-dependent flux and 1,240,000 ft3 /d was simulated as specified flux. In the 

Jacobs Creek drainage basin, a total of 339,000 ft3 /d of base flow was simulated as headdependent flux and 450,000 ft3 /d was simulated as specified flux. All stream reaches 

downstream from the Stony Brook streamflow-gaging station were simulated as headdependent-flux boundaries.

Ground-Water Pumpage

Reported ground-water pumpage in the study area for 1987 is 406.74 million gallons 

(table 6). The largest purveyors in the study area are Hopewell Borough, Pennington Borough, 

and Elizabethtown Water Company. Water pumped by Hopewell and Pennington Boroughs is 

used for domestic needs for residents of those two boroughs. Water pumped by Elizabethtown 

Water Company1 enters a large distribution system that extends well beyond the study area. 

Most of the water pumped from the study area by Elizabethtown Water Company probably is 

used outside the study area. The locations of wells listed in table 6 are shown in figure 18.

1 The use of company names in this report is for identification only and does not impute responsibility for any present or 

potential effects on the natural resources.

45
Table 6. Reported ground-water pumpage exceeding 1 million gallons per year in the Stony Brook. 

Beden Brook, and Jacobs Creek drainage basins, west-central New Jersey. 1987

[Data from NJ. Department of Environmental Protection; pumpage was reported as totals for each 

owner because withdrawal data for individual wells for 1987 are not available; USGS, U.S. Geological 

Survey; e, pumpage estimated by apportioning total reported 1987 pumpage for the purveyor on the 

basis of reported 1986 pumpage from individual wells]

USGS well 

number Well owner Geologic unit

Total pumpage 

(millions of 

gallons)

Stony Brook drainage basin upstream from streamflow-gaging station 01401000

210257 Hopewell Valley Golf Course Passaic

210090 Pennington Borough Passaic

210269 Pennington Borough Passaic

210373 Pennington Borough Passaic

210309 Educational Testing Service Lockatong

210308 Educational Testing Service Lockatong

210251 Educational Testing Service Lockatong

210242 Mobil Research and Development Corp. Passaic *i

210376 Mobil Research and Development Corp. Passaic /

210267 American Telephone and Telegraph Passaic 

210408 American Telephone and Telegraph Passaic

210250 American Telephone and Telegraph Passaic

210409 American Telephone and Telegraph Passaic 

2.27

e27.63

e23.74

e7.67

11.210

30.650

3.6

Stony Brook drainage basin downstream from streamflow-gaging station 01401000

210196

210288

210087

210189

210277

210275

210244

Elizabethtown Water Co. 

Elizabethtown Water Co.

Stockton "i 

Stockton J

183.56

Beden Brook drainage basin

Hopewell Borough 

Hopewell Borough 

Hopewell Borough

Stockton 

Stockton 

Passaic

lacobs Creek drainage basin

Pennington Borough 

Washington Crossing Water Co.

Passaic 

Passaic

73.710

e34.87 

7.831

46
EXPLANATION 

 Well location

Drainage-basin boundary

74°45'

\

74°50'

74°40'

40°25'

L

Hopewell 

 Borough 

weds

Washington Crossing 

Water Company 

well

I ^ / Hopewell VafleyV / , _ American Telephone - 

1 f ( Golf Course - ' -Tfand Telegraph Compai

/ \well ' -v. , '-; -' / ,- ,' *x wells ',;

* * * ' ' " " ^ ^ ' v " x , ' N /"" -" 

/ / / ' - , \ Mobil Research 

1 \ ' / * " / »and Development * 

' ( x -. \*' Corporation

. -' V-"-; lA/pllc ^ *

. ^ . > , . ' ' WtfllO -^

1 ' ") / ' -<'""^

40°20'-*=^. ' I * ,-'-*.o/ ,. . ;/ r 

', - . ^ - Pennjngtor) ' / . ' "^ 

/ . s* Borough,./'" / 

/ , f ' 1 wells f ^ .'

V ^.,: '.; " 7 . ' ^'f

CrnsKinn ' - / I /

" ' s ^ ' 'v

 - / * \ _, -

 Educational 

Testing Service wells '-'

';/ > .'/ -.

v.^ ,

(.. y

/

3 MILES

Elizabethtown 

Water Company 

wells

0 1 3 KILOMETERS

Figure 18. Public supply, industrial, and commerical wells in the study area, 

Stony Brook, Beden Brook, and Jacobs Creek drainage basins, west-central 

New Jersey.

47
Ground-water pumpage from the part of the Stony Brook drainage basin upstream from 

the streamflow-gaging station was 106.77 million gallons in 1987. This is equal to an average of 

0.14 in/yr over the gaged part of the basin. This pumpage included all of the water withdrawn 

by Educational Testing Service, Mobil Research and Development Corporation, Hopewell Valley 

Golf Course, American Telephone and Telegraph Company, and three of the Pennington 

Borough wells. Wells owned by the Elizabethtown Water Company are in the part of the Stony 

Brook drainage basin downstream from the gaging station.

Ground-water pumpage from the Beden Brook drainage basin was 73.710 million gallons 

in 1987. This pumpage consists of water withdrawn from the Hopewell Borough wells and is 

equal to an average of 0.154 in/yr over the basin area.

Ground-water pumpage from the Jacobs Creek drainage basin was 42.70 million gallons 

in 1987. This pumpage consists of water withdrawn from the Washington Crossing Water 

Company well and one of the Pennington Borough wells and is equal to an average of 

0.185 in/yr over the basin area.

Because average pumpage data are not available for the entire period 1954-91 for many of 

the purveyors, 1987 pumpage was added to the 1954-91 average-annual base flow to estimate 

prepumpage base flow. Average pumpage for 1954-91 is probably slightly lower than the 1987 

pumpage; however, the 1987 pumpage is considered to be an adequate estimate of the average 

pumpage because the 1987 pumpage is low compared to the overall water budget. Therefore, an 

overestimate of pumpage would not significantly affect the overall water budget.

Ground-Water Flow to and from Adjoining Drainage Basins

Small amounts of ground water flow across the surface-water drainage divides along 

parts of the study-area boundary near Baldpate and Sourland Mountains-and at drainagebasin divides within the study area. The amount of flow that crosses basin boundaries from 

outside the model area initially was estimated on the basis of the amount of recharge to and 

surface runoff from the source areas of these flows. The part of Sourland Mountain that is 

outside the study area is about 2 miles long and covers an area of about 1.2 mi2. Recharge to that 

part of the mountain is estimated to be about 31,400 ftVd on the basis of the average recharge 

rate to diabase rocks. The digital model best simulated measured heads when the rate was 

adjusted to 27,300 ft3 /d. This water probably is derived in total or mostly from recharge to 

Sourland Mountain because a stream there probably captures any surface runoff.

The part of Baldpate Mountain that slopes eastward toward the study area consists of 

about 0.75 mi2. Recharge to this part of the mountain is about 20,000 ftVd, on the basis of the 

average recharge rate to diabase rocks, and surface runoff is about 76,000 ftVd. Because no 

streams flow through the eastern part of Baldpate Mountain, all of the direct runoff from the 

mountain may infiltrate the more permeable Passaic Formation rocks adjacent to the mountain 

near the study-area boundary and flow into the study area along with the recharge to the eastern 

part of the mountain. Therefore, the initial estimate of flow crossing the model boundary in this 

area was 96,000 ft3 /d distributed over 10 model cells. During model calibration, this amount 

was increased to 104,000 ft3 /d.

Flow rates across drainage divides within the study area-between Jacobs Creek and 

Stony Brook and between Stony Brook and Beden Brook were derived directly from the 

calibrated digital model. Flow from the Beden Brook drainage basin to the Stony Brook drainage

48
basin amounts to 14,400 ft3 /d . Flow from the gaged part of the Stony Brook Basin consists of 

4,750 ft3 /d to the Jacobs Creek Basin and 7,860 fr/d to the part of the Stony Brook Basin 

downstream from the streamflow-gaging station. Most of the flow (90 percent) between these 

adjoining basins occurs in model layer 1 along short flow paths in areas where ground-water 

divides are offset slightly from surface-water divides. The small amount of interbasin flow in 

layer 2 is deep flow from topographically high areas (such as areas underlain by diabase rocks) to 

lowlying streams, such as the downstream reaches of Jacobs Creek and Stony Brook. This deep 

flow is depicted in figure 10 by the long flow lines.

Areal Recharge

The average areal recharge rate for each drainage basin was estimated from base flow. 

The average rates were then adjusted to account for differences in recharge rates to the different 

rock types in the study area.

Initial estimates

Initial estimates of areal recharge were made by two methods. One estimate was made 

with the assumption that recharge equals base flow to streams. For the part of the Stony Brook 

drainage basin upstream from the streamflow-gaging station, the recharge rate estimated in this 

way is 8.06 in/yr. For the Beden Brook and Jacobs Creek drainage basins, the average areal 

recharge estimated in this way are 10.2 and 10.3 in/yr, respectively.

The second initial estimate of areal recharge was made with the assumption that base 

flow equals precipitation minus evapotranspiration and direct runoff. This estimate was made 

only for the Stony Brook drainage basin because estimates of direct runoff, which are based on 

continuous streamflow data, are available only for that basin.

Mean-annual precipitation in the study area during the 30-year period 1951-80 was 45.07 

inches (table 7). Precipitation in the study area was estimated from the weighted average meanmonthly precipitation at the three weather stations nearest the study area. Weights assigned to 

each station were based on the part of the study area that is nearest the station-Lambertville, 

0.403; Flemington, 0.348; and Hightstown, 0.248.

Mean-annual evapotranspiration was estimated with the method described by 

Thornthwaite and Mather (1955). This method incorporates mean-monthly air temperature and 

number of hours of sunlight. The method provides an estimate of potential evapotranspirationthe total amount of evaporation and transpiration that could occur if there were a constant 

supply of water in the soil. The estimated potential evapotranspiration in the study area is 27.28 

in/yr. Mean-monthly estimates are listed in table 7. The Thornthwaite and Mather method does 

not take into account land use, soil type, or topography, all of which affect the ratio of direct 

runoff to precipitation. This ratio is relatively high in the study area~26 percent; consequently, 

the water available for evaporation and transpiration from the soil is relatively low. Therefore, 

the potential evapotranspiration rate estimated by using this method probably is higher than the 

actual evapotranspiration rate in the study area.

The estimated recharge rate for the Stony Brook Basin based on precipitation, potential 

evapotranspiration, and direct runoff is 5.98 in/yr, which is significantly lower than the estimate 

based on base flow Because the evapotranspiration rate used in the second estimate probably 

was too high, the estimate based on base flow is considered to be the more accurate of the two 

estimates.

49
Table 7. Mean-monthly air temperature, potential evapotranspiration, and precipitation in the study 

area, Stony Brook, Beden Brook,, and Jacobs Creek drainage basins, west-central New Jersey

[Mean-monthly air temperature and precipitation are for the 30-year period 1951-80 (National Oceanic 

and Atmospheric Administration, 1990). Mean-monthly temperature and precipitation for the study area 

were estimated from the weighted average mean-monthly air temperature and precipitation for the three 

weather stations nearest the study area. Weights assigned to each station are based on the part of the 

study area that is nearest the station-Lambertville, 0.403; Remington, 0.348; and Hightstown, 0.248]

	Mean-monthly Mean-monthly Mean-monthly 

	air temperature evapotranspiration precipitation 

Month (degrees Fahrenheit) (inches) (inches)

January 29.5 0 3.47

February 31.3 0 3.01

March 40.0 .52 4.09

April 50.8 1.75 3.82

May 60.6 3.28 3.67

June 69.7 4.88 3.46

July 74.5 5.59 4.27

August 73.4 5.02 4.67

September 66.0 3.54 3.86

October 54.7 1.89 3.31

November 44.2 .76 3.69

December 33.6 .05 3.75

Total 27.28 45.07

50
The estimated recharge rates are average rates for each basin. Within each basin, the 

recharge rate varies areally as a result of the presence of geologic and topographic features such 

as diabase rocks and the Hopewell Fault. These features and their effects on areal-recharge rates 

are discussed in the following sections.

Effect of diabase rocks

Diabase rocks significantly affect the areal distribution of recharge. Conceptually, areas 

underlain by diabase rocks were hypothesized to receive less areal recharge than areas underlain 

by the more permeable sedimentary aquifers. Infiltration and percolation of precipitation is 

hindered in areas underlain by diabase because the slopes are steeper in these areas than in other 

parts of the study area.

A comparison of base-flow rates in streams draining areas underlain by diabase rocks 

with base-flow rates in streams draining areas underlain by sedimentary rocks supports this 

hypothesis. In August and November 1987, base flow was measured at several sites throughout 

the study area (Jacobsen and others, 1993, p. 63-66). In each of the three surface-water drainage 

basins, base flow was measured at one site whose drainage area is wholly or mostly underlain by 

diabase rocks. Ground-water-runoff rates (base flow divided by drainage area) at these three 

sites were compared to those at the furthest station downstream at which base flow was 

measured on the same day or, at one station, the previous day. The stations furthest downstream 

were selected with the assumption that base flow at these sites would be approximately equal to 

average base flow in the basin. The base-flow and runoff data for these stations indicate that the 

ratio of runoff in areas underlain by diabase to runoff in areas underlain by all rock types is 

approximately 0.375 (table 8). The locations of the base-flow-measurement sites used in this 

analysis are shown in figure 17.

Some of the precipitation that does not infiltrate into the diabase rocks was assumed to 

run over land surface or through the unsaturated zone and subsequently infiltrate downslope in 

areas underlain by the more permeable rocks near the borders of the diabase sills. The total 

amount of additional recharge received by these areas was assumed to be equal to the difference 

between the total amount of recharge that would have been applied to the diabase areas if they 

were underlain by other rocks and the actual amount of recharge applied to the diabase rocks. 

For each diabase sill, the total amount of additional recharge was distributed evenly among cells 

surrounding the sill. The additional recharge was applied one cell away from the edge of each 

diabase sill to account for the relatively impermeable hornfels rocks that surround each sill.

For example, the diabase rocks that comprise Pennington Mountain (fig. 4) occupy an 

area of about 34,500,000 fr. If this area were underlain by one of the sedimentary aquifers, it 

would receive recharge at a rate of 8.20 in/yr (64,600 ftVd) rather than 4.11 in/yr (32,400 ft3 ). 

The difference-32,200 ft3~was assumed to be the water that flows overland or in the unsaturated 

zone and then enters the ground-water system when it reaches the sedimentary rocks. The 

additional recharge was distributed evenly among the 45 model cells surrounding Pennington 

Mountain. Consequently, 12.5 in/yr of recharge was added to the 8.20 in/yr that this area is 

assumed to receive directly from precipitation for a total recharge rate of 20.7 in/yr to the cells 

surrounding Pennington Mountain.

51
Table 8. Ground-water-runoff rates in areas underlain bv diabase rocks and in areas underlain bv all

rock tvoes in the Stonv Brook, Beden Brook, and Tacobs Creek drainage basins, west-central New

Jersey

[mi2, square miles; f\?/s, cubic feet per second; in/yr, inches per year]

Date of 

measurement

08/14/87 

08/13/87

11/20/87 

11/20/87

08/13/87 

08/13/87

11/19/87 

11/19/87

08/13/87 

08/13/87

11/19/87 

11/20/87

Station 

number

01400870 

01401000

01400870 

01401000

01401540 

01401600

01401540 

01401600

01402730 

01402800

01402730 

01402800

Rock 

type

Diabase 

All

Diabase 

All

Diabase 

All

Diabase 

All

Diabase 

All

Diabase 

All

Drainage 

area 

(mi2 )

2.60 

44.5

2.60 

44.5

3.84 

27.6

3.84 

27.6

1.84 

13.3

1.84 

13.3

Discharge 

(ftVs)

0.25 

12.8

1.25 

29.0

.07 

11.8

.20 

22.0

.31 

5.54

1.06 

11.6

Groundwater 

runoff 

(in/yr)

1.31 

3.90

6.53 

8.85

.247 

5.80

.707 

10.8

2.29 

5.65

7.82 

11.8

Ratio of 

runoff in

areas 

underlain 

by diabase 

to runoff 

in areas 

underlain 

by all 

rock types

0.336

.738

.043

.065

.405

.663

Average ratio of runoff in diabase to runoff in all rock types: 0.375

52
Effect of Hooewell Fault

The hydrologic system varies along the fault zone. The escarpment is steeper in the 

eastern part of the study area than in the western part, and a stream flows along the fault in the 

western part of the study area. These features affect the rate of recharge to the fault zone.

In the eastern part of the study area, the escarpment on the northwestern side of the 

Hopewell Fault was hypothesized to have a similar effect on recharge as the diabase rocks do, 

and the relatively permeable rocks in the fault zone enhance recharge. Recharge at the base of 

the escarpment is analogous to the flow of precipitation along a roof and into a drain along the 

side of a building. All of the direct runoff from precipitation that flows down the fault 

escarpment probably enters the ground-water system in the fault zone. This amounts to 

162,000 ft3 /d (64.4 in/yr) distributed among 44 cells at the foot of the escarpment.

The digital model best simulated measured heads and base flow when recharge was 

applied at the foot of the fault escarpment at a rate of 95 in/yr. The additional 31 in/yr of 

recharge at the fault zone probably is derived from precipitation that falls directly on the fault 

zone. The high permeability of the rocks in the fault zone probably results in little or none of this 

precipitation being lost to direct runoff. Also, less water is lost to evapotranspiration in the fault 

zone than in other parts of the study area because vertical conductivity in the fault zone is 

sufficiently high to allow much of the precipitation to flow down past the root zone before it can 

be used by vegetation.

In the western part of the study area, where the fault escarpment is less steep than in the 

eastern part, less runoff reaches the fault zone. Runoff that does reach the fault zone probably is 

captured by the stream that runs along the escarpment. Therefore, no additional areal recharge 

was simulated in the model along this part of the fault zone.

Areal recharge rates in the digital model

In the digital model, rates of recharge to diabase rocks and non-diabase rocks were 

assumed to be constant throughout the study area, except in the fault zone. The rates applied to 

the diabase and non-diabase rocks were 4.11 and 8.20 in/yr, respectively. Because the total area 

underlain by diabase rocks and non-diabase rocks varies from basin to basin, and because the 

recharge rate in the fault zone varies, the overall average recharge rate is different for each basin. 

The average rates of areal recharge for the Stony Brook (above the streamflow-gaging station), 

Beden Brook, and Jacobs Creek Basins are 8.25,9.11, and 8.11 in/yr, respectively, and the average 

rate over the entire study area is 8.58 in/yr.

Values of Hydraulic Conductivity and Conductance from Calibrated Digital Model

Hydraulic-conductivity zones in the model were established to coincide with the 

outcrops of geologic units (fig. 4) because lithology was found to be the major determinant of 

hydraulic conductivity. Simulated values of horizontal hydraulic conductivity, vertical 

conductance, and streambed conductance are listed in table 9.

The simulated values of horizontal hydraulic conductivity used in the model represent 

the hydraulic conductivity of each model layer as a whole rather than that of the individual 

water-bearing zones or confining units that comprise each model layer. Similarly, the verticalconductance values used in the model and reported in table 9 are based on the vertical hydraulic 

conductivity of each entire model layer.

53
Table 9. Simulated values of horizontal hvdraulic conductivitv. vertical conductance, and streambed

conductance factor in the Stonv Brook. Beden Brook, and Jacobs Creek drainaee basins, west-central

New Jersey 

[NA, not applicable; ft/d, feet per day; ft"1 , per foot]

Formation

or zone

Diabase

Diabasestream cells

Passaic

Passaic 

stream cells

PassaicLockatonglike strata

PassaicLockatonglike strata--

stream cells

Lockatong 

northern zone

Lockatongnorthem zonestream cells

Lockatong 

southern zone

Lockatong 

southern zonestream cells

LockatongPassaiclike strata

LockatongPassaic-like stratastream cells

Stockton -

northern zone

Stocktonnorthern zonestream cells

Stocktonsouthern zone

Stocktonsouthern zone

stream cells

Fault zone

1. Vertical conductance = -

i

Horizontal hydraulic conductivity

Layer 1 Layer 2

Strike Dip Strike Dip

direction direction direction Direction

(ft/d) (ft/d) (ft/d) (ft/d)

0.1 0.1 0.001 0.001

1.00 1.00 .01 .01

50 25 25 .025

500 250 2.5 .25

2 1 .01 .001

20 10 .1 .01

10 5 .05 .005

100 50 .5 .05

2 1 .01 .001

20 10 .1 .01

50 25 25 .025

500 250 2.5 .25

.50 .25 .0025 .00025

5 2.5 .025 .0025

17.5 8.75 .0875 .00875

175 87.5 .875 .0875

100 50 50 5

1

 where m, and m0 = thickness of layers 1

Wj/2 m2 /2 12 '

Vertical

conductance1

(ff1 )

7.00 x Iff5

7.00 x Iff4

3.74 x Iff4

3.74 x Iff3

5.50 x Iff6

5.50 x Iff5

3.00 x Iff5

3.00 x Iff4

5.50 x Iff6

5.50 x Iff5

3.74 x Iff4

3.74 x Iff3

3.00 x Iff6

3.00 x Iff5

1.72x10-*

1.72 x Iff3

7.00 x Iff2

Streambed

conductance

factor2

(ft/d)

NA

0.1

NA

1.5

NA

1.5

NA

1.5

NA

1.5

NA

1.5

NA

.1

NA

1.5

1.5

and 2, respectively, and

Xz,

2. Streambed-conductance factor =

KS W 

m

and Xz~ = vertical hydraulic conductivity of layers 1 and 2, respectively.

where K = hydraulic conductivity of the streambed material, 

W = width of the stream, and m = thickness of the streambed.
Except at the fault, the contacts between geologic units dip at the same angle as the rock 

layers-12 to 15 degrees to the northwest. Therefore, the actual contacts span a distance of about 

2,400 to 2,800 ft, or about four to six model cells, in the 500-ft thickness simulated by the model. 

For this reason, changes in conductivity at contacts were distributed over a four-cell width (two 

cells on each side of a contact) on a logarithmic scale. For example, at the contact between a zone 

in which the horizontal hydraulic conductivity in the strike direction is 175 ft/d and a zone in 

which the conductivity is 2 ft/d, the simulated hydraulic conductivities in the four cells nearest 

the contact are 175,39,9, and 2 ft/d.

Another reason for distributing the change in conductivity over a four-cell width at 

contacts is that all of the contacts are gradational rather than sharp. The contacts between the 

Stockton and Lockatong Formations and between the Lockatong and Passaic Formations 

represent gradual changes in lithology, whereas the contact formed by the Hopewell Fault is 

gradual because the extent of fracturing caused by faulting decreases with distance from the 

fault. Contacts at the edges of diabase sills are gradational because of the presence of altered 

rocks (hornfels) around the sills.

Horizontal Hydraulic Conductivity in the Direction of Strike

Horizontal hydraulic conductivity in the strike direction varies from 0.1 to 500 ft/d in 

layer 1 and from 0.001 to 50 ft/d in layer 2.

Diabase rocks

The simulated hydraulic conductivity of the diabase rocks in model layer 1 was 0.1 ft/d. 

This was the lowest value of hydraulic conductivity used in layer 1 and is consistent with the 

conceptual model of ground-water flow, in which the relatively impermeable diabase rocks 

impede ground-water flow.

The simulated hydraulic conductivity of the diabase rocks in layer 2 of the digital model, 

0.001 ft/d, is lower than the conductivity in layer 1 by a factor of 100. This difference reflects the 

decrease in permeability and the density of fractures with depth below land surface as 

determined from specific-capacity values and the numbers of fractures in rock cores.

Stockton Formation

Two zones of different conductivity in the Stockton Formation in the digital model 

coincide with the two areas in which the formation crops out at the southern border of the study 

area and on the northern side of the Hopewell Fault (fig. 4). The hydraulic conductivity used in 

layer 1 of the digital model for the Stockton Formation at the southern border of the study area 

(17.5 ft/d) is much higher than the value used for the area north of the fault (0.5 ft/d). The value 

used for the southern outcrop is more representative of the Stockton Formation than the one 

used for the northern outcrop because the Stockton Formation is reported to be the most 

permeable aquifer in the area. The low hydraulic conductivity of layer 1 in the northern outcrop 

of the Stockton Formation is a function of the depth below land surface (average 110 ft) of the 

bottom of layer 1 in this area. Consequently, model layer 1 in this area represents rocks that are, 

on average, less fractured and less permeable than the rocks in layer 1 elsewhere in the model.

In layer 2 of the digital model, the simulated hydraulic conductivity of the Stockton 

Formation was set lower than that of layer 1 by a factor of 200 to account for the decrease in 

permeability with depth.

55
Lockotong Formation

The Lockatong Formation was divided into thee zones of hydraulic conductivity in the 

digital model. Two of these zones coincide with the two areas in which the formation crops 

out-north of each of the two Stockton Formation outcrops (fig. 4). The third zone consists of the 

parts of the Lockatong Formation that are mapped as a separate geologic unit (Trlr) in figure 4 

This zone was assumed to have the same hydraulic properties as the Passaic Formation and was 

therefore was assigned the same hydraulic conductivity.

The principal (strike-direction) hydraulic-conductivity values used for the Lockatong 

Formation in model layer 1 are 2.0 ft/d near the southern border of the study area and 10.0 ft/d 

for the area north of the fault. Initially a value of 2.0 ft/d was assigned to both of these zones. 

During model calibration, however, a closer match between measured and simulated heads and 

base flow was achieved by increasing the value for the zone north of the fault to 10.0 ft/d. The 

difference in hydraulic conductivity in these two zones probably reflects a difference in lithology 

The northern zone may include some thin, unmapped zones of Passaic Formation-like rocks 

(Trlr) similar to those mapped in the southern band, which would cause the overall conductivity 

of the northern band to be higher than that of the southern band.

Simulated hydraulic conductivity of the Lockatong Formation was lower in layer 2 of the 

digital model than in layer 1 by a factor of 200-the same ratio as that used for the Stockton 

Formation.

Passaic Formation

Two zones of hydraulic conductivity were used for the Passaic Formation in the digital 

model. One of these zones consists of the two areas where Passaic Formation crops out-the 

large area south of the Hopewell Fault and the small area in the northwestern part of the study 

area (fig. 4). The principal (strike-direction) conductivity value used for these areas in model 

layer 1 is 50.0 ft/d (table 9). The second zone consists of the parts of the Passaic Formation that 

are mapped as a separate geologic unit (Trpg) in figure 4. This zone was assumed to have the 

same hydraulic conductivity as the southern zone of the Lockatong Formation (2.0 ft/d).

Simulated hydraulic conductivity of the Passaic Formation was lower in layer 2 of the 

digital model than in layer 1 by a factor of 200 the same ratio as that used for the Stockton and 

Lockatong Formations.

Fault zone

The hydraulic conductivity of the fault zone was assumed to be higher than that of the 

surrounding rocks on the basis of reports of wells with high yields and high specific capacities in 

the fault zone. The fault zone consists of a 1,000-ft-wide (two-model-cell-wide) area that extends 

through the model area from southwest to northeast (fig. 4) and through both model layers. 

Simulated heads in the digital model were nearest to measured heads when conductivities of 

100 ft/d and 50 ft/d were used for layer 1 and layer 2, respectively, of the fault zone.

Areas near streams

Streams in the study area generally follow the outcrops of water-bearing zones or joints. 

For this reason, the hydraulic conductivity of the aquifers was arbitrarily set higher in cells 

containing streams (fig. 12) than in other cells by a factor of 10 (table 9). Hydraulic conductivity

66
in cells in layer 2 underlying streams also were increased by a factor of 10 because the waterbearing zone in layer 1 was assumed to continue into layer 2.

Horizontal Anisotropy Ratio

The ratio of hydraulic conductivity in the strike direction to hydraulic conductivity in the 

dip direction (the anisotropy ratio) used in the model was 2:1 in layer 1 and 10:1 in layer 2 for all 

of the sedimentary aquifers and for the fault zone. The lower ratio used for layer 1 is related to 

the higher density of fractures and greater effects of weathering in the shallow part of the 

aquifers compared to deeper part of the aquifers. Rock layers that act as confining units are 

much more fractured near land surface than at depth. Consequently, the confining effect of these 

layers is diminished near land surface and anisotropy also is diminished. In addition, 

intergranular porosity of some of the shallow rocks makes them more isotropic than the 

underlying, less weathered rocks.

The diabase rocks are assumed to be isotropic because they are not layered and because 

the fracture pattern in diabase rocks is more random than in the sedimentary rocks. 

Consequently, an aniostropy ratio of 1:1 was assigned to model cells representing diabase rocks.

Vertical Hydraulic Conductance

Vertical-hydraulic-conductance values used in the digital model are listed in table 9. 

McDonald and Harbaugh (1988, p. 5-13) define the vertical conductance between two model 

layers that represent two adjacent hydrogeologic units whose vertical conductivities differ 

according to the equation

Vertical conductance = ml/2 ml/2 ' 

Kzl + Kz2

where ml and m2 = thicknesses of layers 1 and 2, respectively, and

Kzl and Kz2 = vertical hydraulic conductivities of layers 1 and 2, respectively.

As a first approximation, the vertical conductivity of the sedimentary aquifers and the 

fault zone was estimated to be equal to the horizontal hydraulic conductivity in the dip direction. 

The saturated thicknesses of layers 1 and 2 were approximated at 50 ft and 425 ft, respectively. 

During model calibration, simulated heads were found to be highly sensitive to changes in 

vertical conductance. In the calibrated model, all initial estimates of vertical conductance were 

increased by factors ranging from 1.28 for the Passaic Formation to 4.17 for the southern zone of 

the Stockton Formation. The resulting calibrated conductance values indicate that the vertical 

hydraulic conductivity of the Stockton, Lockatong, and Passaic Formations is slightly higher 

than the dip-direction horizontal conductivity The vertical conductance of cells containing 

streams and cells below streams in layer 2 was increased by a factor of 10 for the same reasons as 

those described for horizontal conductivity. The change in vertical conductance at geologic 

contacts was distributed over a four-cell width in the same way as was the change in horizontal 

hydraulic conductivity.

57
Streambed Hydraulic Conductance

In the digital model, all reaches of Stony Brook, Beden Brook, and Jacobs Creek except 

the uppermost reaches were simulated as head-dependent-flux boundaries by using the "River 

module" of the McDonald and Harbaugh (1988) flow model. The rate of flow between the 

streams and the aquifer is controlled by the head difference between the aquifer and the stream 

and by the hydraulic conductance of the stream-aquifer interconnection. McDonald and 

Harbaugh (1988, p. 6-5) define this hydraulic conductance according to the equation

ms 

where CRIV = the hydraulic conductance of the stream-aquifer interconnection,

Ks = the vertical hydraulic conductivity of the streambed material,

L = the length of the reach,

W = the width of the stream, and

ms = the thickness of the streambed.

Streambed material in the study area consists of clayey silt, silt, sandy silt, or fractured 

bedrock with one of these materials filling the fractures. As a first approximation, the hydraulic 

conductivity of the streambed material was assumed to be equal to the hydraulic conductivity of 

silt, about 0.1 ft/d (Heath, 1983, p. 13). The length of stream reach within each model cell was 

determined by digital scanning of topographic maps. The width of the three major streams was 

estimated at 20 ft in all reaches-the approximate average width of Stony Brook, Beden Brook, 

and Jacobs Creek at sites where stream discharge was measured. The thickness of the streambed 

was estimated to be 5 ft. Because the length of the stream within each model cell could be 

determined exactly, but the other parameters included in the conductance are estimates, the 

length of each reach was held constant during model calibration and a streambed conductance 

factor the product of the other three parameters was adjusted.

The initial estimate of streambed conductance factor was 0.4 ft/d. In the calibrated 

model, heads and base flow were best simulated when a streambed conductance factor of 

0.1 ft/d was applied to stream reaches underlain by the diabase rocks and by the Stockton 

Formation outcrop north of the Hopewell Fault. The streambed conductance factor applied at all 

other stream reaches was 1.5 ft/d. The relatively low streambed conductance factor for the 

diabase probably results from the presence of a relatively high percentage of clay in the 

streambed material. Diabase rocks weather to a more clayey material than do other rocks in the 

study area. The relatively low hydraulic conductivity for the part of the Stockton Formation that 

crops out north of the Hopewell Fault probably is caused by the low conductivity of the rocks 

underlying the streambed. Streams in this area are very deeply incised, and the rocks at depth 

are less extensively fractured than shallower rocks. The rocks underlying the streambed 

probably are less permeable than the streambed, so the hydraulic connection between the stream 

and the aquifer is controlled by the conductivity of the bedrock rather than by the conductivity of 

the streambed.

58
Vertical Distribution of Ground-Water Flow

In the conceptual model ground-water flow was hypothesized to occur mostly in the 

shallow part of the system because the decrease in the density of fractures with depth restricts 

flow in the lower part of the system. In the calibrated digital model, 94 percent of the recharge to 

layer 1 remains in layer 1 and discharges to streams near the point of recharge. The other 6 

percent of recharge flows downward from layer 1 to layer 2, flows a relatively long distance-up 

to a few miles-in layer 2, and then flows back into layer 1 and discharges to one of the major 

streams (Stony Brook, Beden Brook, or Jacobs Creek).

SUMMARY AND CONCLUSIONS

This study was undertaken as part of the Appalachian Valleys-Piedmont Regional 

Aquifer-Systems Analysis to characterize ground-water flow in the Mesozoic structural basins of 

the eastern United States. The study area consists of about 89 mi in the Newark Basin of New 

Jersey. Ground-water flow in the Mesozoic-basin rocks is controlled by a complex hydrogeologic 

framework consisting of dipping beds of fractured sedimentary rocks, massive diabase rocks, 

and faults.

The study area is underlain by three sedimentary rock formations the Stockton, 

Lockatong, and Passaic Formations and by diabase sills. The sedimentary formations all 

contain fractured siltstone, shale, and sandstone; the Lockatong Formation also contains beds of 

massive, sparsely fractured argillite. The three formations are differentiated on the basis of the 

proportion of each rock type present. In these sedimentary formations, extensively fractured 

water-bearing units are interlayered with sparsely fractured confining units. The diabase rocks 

are massive and very impermeable relative to other rocks in the study area. All of the formations 

are thousands of feet thick in the study area. The density of fractures in all of the rocks decreases 

with depth and, in rocks more than about 500 ft below land surface, fractures are so sparse that 

ground-water flow is negligible.

The Hopewell Fault is a major, near-vertical fracture that extends vertically though all of 

the formations and trends northeast through the study area. Rocks on both sides of the fault are 

extensively fractured.

The beds of the sedimentary rocks dip about 12 to 15 degrees to the northwest. 

Therefore, within the study area, each water-bearing unit extends only from its outcrop area 

downdip to a depth of about 500 ft below land surface, where the permeability is negligible. 

Along strike, however, each water-bearing unit is extensive. Because the water-bearing units are 

much more extensive in the strike direction than in the dip direction, ground-water flow is 

anisotropic, and ground-water-flow directions are skewed toward the strike direction. This 

causes dip-aligned streams to receive more base flow and strike-aligned streams to receive less 

base flow than they would if the system were isotropic. Between land surface and about 50 to 

150 ft below land surface, ground-water flow is unconfined because fractures are dense and 

interconnected. At greater depths, sparsely fractured beds impede flow enough to cause 

confined conditions.

The aquifers in the study area differ with respect to average specific capacity per foot of 

open hole. For the Stockton, Lockatong, and Passaic Formations and diabase rocks, the median 

specific capacity per foot of open hole is 0.00545,0.00115,0.00393, and 0.00143 ((gal/min)/ft)/ft, 

respectively. The decrease in the density of fractures with depth below land surface also is

59
reflected in specific-capacity data. The mean specific capacities per foot of open hole of wells that 

are less than 76 ft deep are two to six times greater-depending on geologic formation-than those 

of wells 76 to 100 ft deep. Reported transmissivities range from 100 to 4,700 ftVd for the 

Stockton Formation and from 900 to 4300 ftVd for the Passaic Formation. Storage coefficients 

estimated from results of aquifer tests range from 0.00001 to 0.367.

Water-level data for wells and streams in the study area indicate that ground-water 

divides generally coincide with surface-water divides and that most ground water discharges to 

streams near the point of recharge. Exceptions are found where water enters the ground-water 

system in topographically high areas underlain by diabase rocks and flows under one or more 

surface-water divides before discharging to a stream.

Because diabase rocks are very impermeable and resistant to erosion relative to other 

rocks in the study area, they form topographically high areas. The rate of areal recharge to these 

rocks is about one-half the rate of recharge to other rocks, and the surface-runoff rate is higher. 

Excess surface runoff flows downslope over land or in the unsaturated zone and enters the 

ground-water system where it encounters more permeable non-diabase rocks downslope.

Most ground-water flow in the study area occurs between the water table and 75 ft below 

land surface. When the system is unstressed, only about 6 percent of the recharge at land surface 

reaches depths greater than 75 ft below land surface.

Water that flows to pumped wells generally is derived mostly from the water-bearing 

units intersected by the well opening. Wells near surface-water bodies also derive a significant 

amount of water from the surface-water body by induced infiltration.

A three-dimensional finite-difference digital model of steady-state, prepumping groundwater flow in the study area was developed to test hypotheses concerning the hydrologic 

processes and geologic features that control ground-water flow. The decrease in hydraulic 

conductivity with depth was simulated by discretizing the model into two layers, with the 

conductivity of the upper layer much greater than that of the lower layer. The upper layer 

represents the unconfined part of the aquifer system and is generally less than 75 ft thick. The 

lower layer is generally 425 ft thick and represents the confined part of the system. Each model 

cell is 500 ft on each side. The lower boundary of the model and most of the lateral boundary 

were simulated as no-flow boundaries. Two small parts of the lateral boundary, where ground 

water flows into the model area from areas underlain by diabase rocks outside the model area, 

were simulated as spetified-flux boundaries. The upper model boundary is the water table, 

which was represented as a free surface. Areal recharge to the water table was simulated as 

specified flux. The main stems of Stony Brook, Beden Brook, and Jacobs Creek were simulated 

as head-dependent-flux boundaries. Tributaries to these streams are simulated as specified-flux 

boundaries.

The model was calibrated by adjusting horizontal hydraulic conductivity, vertical 

conductance, horizontal anisotropy, and streambed conductance until simulated water levels 

and base flow most nearly matched measured water levels and base flow. So that simulated 

heads could be compared to composite measured heads, the model-generated heads for the two 

layers were converted to a single composite head at each model cell on the basis of the saturated 

thickness and hydraulic conductivity of each layer.

60
The digital model was divided into zones of different hydraulic conductivity on the basis 

of the outcrop areas of geologic units. Because all of the contacts between zones are gradational, 

the change in hydraulic conductivity and vertical conductance was distributed over a four-cell 

width at each contact. Horizontal hydraulic conductivities of layer 1 in the strike direction were 

0.1 ft/d for the diabase rocks, 17.5 and 0.5 ft/d for the Stockton Formation, 2.0,10.0, and 50.0 ft/d 

for the Lockatong Formation, 2.0 and 50.0 ft/d for the Passaic Formation, and 100 ft/d in the 

Hopewell Fault zone. The horizontal conductivity of layer 2 was lower than the conductivity of 

layer 1 by a factor of 200, except in the diabase rocks, where the difference was a factor of 100, 

and in the fault zone, where the difference was a factor of 2. The ratio of conductivity in the 

strike direction to the conductivity in the dip direction was 2:1 in layer 1 and 10:1 in layer 2, 

except in the diabase rocks, which were assumed to be isotropic. The vertical conductivity in all 

of the rock units was slightly higher than the dip-direction horizontal conductivity.

The quantity of water in the aquifers of the study area is small relative to other 

hydrogeologic terranes. Average precipitation in the study area is 45.07 in/yr. Average groundwater recharge rates to the Stony Brook, Beden Brook, and Jacobs Creek drainage basins are 8.25, 

9.11, and 8.11 in/yr, respectively. Over the entire study area, the average recharge rate is 

8.58 in/yr.

The digital model developed for this study can be used to analyze the effect of various 

controls on the ground-water system only when the area of analysis is relatively large about 

0.5 mi2 or more. Because the model does not explicitly simulate individual water-bearing units, 

it cannot be used to analyze flow paths on a small or site-specific scale. Adequate analysis of 

ground-water flow on a local scale would require development of a ground-water-flow model 

that simulates flow in each water-bearing unit and consideration of additional geologic 

complexities in the study area, such as the dip of the water-bearing units and the discontinuity of 

water-bearing and confining units in the dip direction.

61
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Rutledge, A.T., 1992, Methods of using streamflow records for estimating total and effective 

recharge in the Appalachian Valley and Ridge, Piedmont, and Blue Ridge physiographic 

provinces, in Hotchkiss, W.R., and Johnson, A.I., eds., Regional aquifer systems of the 

United States-Aquifers of the southern and eastern States: Bethesda, Md., American 

Water Resources Association Monograph Series No. 17, p. 59-73.

Sun, R.J., 1986, Regional aquifer-system analysis program of the U.S. Geological SurveySummary of projects, 1978-84: U.S. Geological Survey Circular 1002,264 p.

Swain, L.A., Hollyday, E.F., Daniel, C.C., IE, and Zapecza, O.S., 1991, Plan of study for the

regional aquifer-system analysis of the Appalachian Valley and Ridge, Piedmont, and Blue 

Ridge physiographic provinces of the Eastern and Southeastern United States, with a 

description of study-area geology and hydrogeology: U.S. Geological Survey WaterResources Investigations Report 91-4066,44 p.

Sutton, P.G., 1984, Straddle packer sampling and testing of wells completed in the Triassic rocks 

of Pennsylvania, in Nielsen, D.M., and Curl, Mary, Proceedings of the Fourth National 

Symposium on Aquifer Restoration and Ground Water Monitoring, May 23-25,1984, 

Columbus, Ohio: National Ground Water Association, p. 244-254.

Theis, C.V., Brown, R.H., and Meyer, R.R., 1963, Estimating the transmissibility of aquifers from 

the specific capacity of wells: U.S. Geological Survey Water-Supply Paper 1536-1, 

p. 331-341.

Thornthwaite, G.W, and Mather, J.R., 1955, The water balance: Publications in Climatology, v. 8, 

p. 345-381.

Vecchioli, John, 1967, Directional hydraulic behavior of a fractured-shale aquifer in New Jersey, 

in Proceedings of the International symposium on hydrology of fractured rocks, 

Dubrovnik, Yugoslavia, 1965, v. 1: International Association of Science and Hydrology 

Publication 73, p. 318-326.

Vecchioli, John, Carswell, L.D., and Kasabach, H.F., 1969, Occurrence and movement of ground 

water in the Brunswick shale at a site near Trenton, New Jersey: U.S. Geological Survey 

Professional Paper 650-B, p. 154-157.

Vecchioli, John, and Palmer, M.M., 1962, Ground-water resources of Mercer County, N.J.: New 

Jersey Department of Conservation and Economic Development, Special Report 19,71 p.

64
REFERENCES CITED--Continued

Widmer, Kemble, 1965, Geology of the ground water of Mercer County: New Jersey Department 

of Conservation and Economic Development, Bureau of Geology and Topography, 

Geologic Report Series no. 7,115 p.

65
Table 4a. Records obtained from U.S. Geological Survey Ground-Water Site Inventory data base for selected wells in and n

Brook, and Jacobs Creek drainage basins, west-central New Jersey

[Altitudes in feet above sea level, rounded to nearest foot; top and bottom of open interval and depth to water rounded to near

rounded to nearest inch; , no data available; depth to water is depth reported at time of well construction; USGS, U.S. Geologi

Geologic-unit codes: PSSC Passaic Formation; LCKG-Lockatong Formation; SCKN-Stockton Formation; DIBS-Diabase rock

Use-of-water codes: C Commercial; H Domestic; I Irrigation; N--Industrial; P~Public supply; R~Recreation; T Institutional 

U~Unused; Z~Other]

USGS

well

number

190045

190050

190059

190060

190080

190233

190234

190239

190240

190241

190242

190244

190250

190251

190258

190267

190269

190278

190282

210028

210087

210088

210090

210132

210136

Use

of

water

H

H

I

I

H

C

H

H

H

H

H

H

U

U

H

H

H

H

H

U

P

U

P

N

P

Owner

EHRET, DONALD

HORSMAN, KEN

CARNAVALE CONSTRUCTION

CARNAVALE CONSTRUCTION

BRITTON. CHARLES

ARGUS INTERNATIONAL

PISARCIK, D

WASABAUGH, F

BLOMQUIST, ALBERT E

COLONIAL SPORTSMENS CLUB

HELEWA, JOSEPH

ANKNER.JOAN

US GEOLOGICAL SURVEY

US GEOLOGICAL SURVEY

GRIFFITHS, BRIAN

KOEPKE, HILBERT

CARRIER. WILLIAM

CARRIER, RONALD

LEWIS, FRANK J

STATE OF NJ

HOPEWELLBOROW

US GEOLOGICAL SURVEY

PENNINGTON WD

BELL TELE CO

WILDERSMTTH.J

Local well

number or

name

EHRET 1

REPLACEMENT-81

2-NURSERY

1 -GREENHOUSE

BRITTON 1

1

PISARCIK

WASABAUGH DOM

BLOMQUIST DOM

COLONIAL SM DOM&POOL

HELEWA 1

ANKNERDOM

WAMWELLTB20BS3

CORSALORDTB1OBS

GRIFFITHS DOM

KOEPKE 1

CARRIER 1

CARRIER DOM

LEWIS DOM

CIVIL DEFENSE

3-1965

HONEY BRANCH 10

PWD5D

BELL LAB 4

WEST WINDSOR TWP

Diameter 

of open 

interval

(inches)

6

6

6

-

6

6

6

6

6

6

6

3

4

6

6

6

6

6

6

8

6

8

8

Year of

construction

1978

1981

1965

1965

1959

1968

1978

1969

1951

1957

1966

1985

1989

1989

1985

1971

1965

1982

1966

1964

1965

1967

1967

1968

1960

Open interval 

(feet below land

surface)

Top

50

50

21

30

20

30

51

25

22

22

31

50

12

22

50

40

23

50

23

33

60

20

42

48

Bottom

160

350

200

405

200

100

100

42

146

192

400

300

428

299

250

310

122

350

60

300

237

150

400

200

252

Geologicunit

code

LCKG

LCKG

LCKG

LCKG

LCKG

PSSC

LCKG

DIBS

DIBS

LCKG

PSSC

PSSC

PSSC

PSSC

PSSC

PSSC

PSSC

LCKG

LCKG

LCKG

SCKN

PSSC

SCKN

PSSC

SCKN

Latitude

(degrees)

402530

402633

402150

402148

402153

402351

402446

402407

402426

402343

402335

402232

402146

402151

402247

402220

402140

402132

402157

401553

402335

402128

402000

401935

401935
o

Brook, and Tacobs Creek drainace basins, west-central New Jersey Continued

uses

well

number

210189

210196

210242

210244

210245

210250

210251

210252

210253

210256

210257

210258

210259

210260

210261

210262

210263

210264

210265

210266

210267

210268

210269

210270

210274

210275

210276

210277

210281

210283

210288

210289

210290

210291

210292

Use

of

water

P

P

N

P

S

C

c

H

H

C

C

H

H

H

H

H

H

H

H

T

C

H

P

C

H

P

H

P

H

T

P

U

z

H

H

Owner

HOPEWELLBOROWC

ELTZABETHTOWN WC

MOBIL RESEARCH LAB

HOPEWELL TWP MUA

AMERICAN CYANAMID CO

WESTERN ELECTRIC CO INC

EDUCATIONAL TESTING SERV

AMER. LEGION POST #339

STEFFANELLL. A

HOPEWELL VAL. GOLF CLUB

HOPEWELL VAL. GOLF CLUB

ROGASKI, BRIAN

MAZ3ARZ.STAN

CHYUN, YONG-CHOL

RULE, MARVIN

GURKA, JOHN

HOLCOMBE, JR, RUSSELL

OLSWFSKI, ANTHONY

ANDERSON, THOMAS

ST PETERS CHURCH

AT&T TECHNOLOGIES

SINCLAIR, PAUL

PENNINGTON BORO

EDUCATIONAL TESTING SERV

ELLIS, WILLIAM

PENNINGTON BORO

VAN NOTE, SHEILA

HOPEWELL BORO

POTTS, JAMES

NJ. HIGHFffiLDS CENTER

ELTZABETHTOWN WATER CO

BRISTOL-MYERS SQUIBB CO

US GEOLOGICAL SURVEY

ASTALOSH. FRANK

COLrVITA.SAM

Local well

number or

name

WELL1

2/STONY BROOK

MOBIL RESEARCH 2

WASH CROSSING EST

CYANAMID D-1959

RESEARCH LAB 3

ETS 2-NEW ETS 1

1 -LEGION HALL

REPLACEMENT-81

4-HANDPUMP

1 -STONY BROOK

ROGASKI 1

MAZIARZ1

CHYUN 1

RULE1

GURKA 1

HOLCOMBE 1

OLSWFSKI 1

ANDERSON FARM-1981

CHURCH 1

RESEARCH LAB 1

SINCLAIR 1

PENNINGTON WD 6

ETS3

ELLIS-1960

WD7

1-1985

4-LOUELLENST

RESIDENCE-1986

LINDBERGH-1931

STONY BROOK 3

100OBS

CORE HOLE B

ASTALOSH

COLTVTTA

Diameter 

of open 

interval

(inches)

6

6

8

12

6

6

6

6

6

6

6

6

6

6

6

6

6

_

6

-

6

10

6

8

6

6

10

8

3

6

6

Year of

construction

1914

1938

1980

1966

1959

1960

1956

1982

1981

1981

1967

1982

1982

1982

1977

1957

1977

1974

1981

1981

1960

1980

1957

1956

1960

1963

1985

1968

1986

1931

1913

1955

1986

1979

1980

Open interval 

(feet below land

surface)

Top

54

50

105

34

31

35

60

63

31

22

42

50

50

47

22

51

51

50

31

38

50

43

32

28

81

50

50

50

33

20

12

20

41

50

Bottom

250

306

600

235

169

400

223

400

250

100

200

350

250

500

277

135

120

285

275

100

400

150

273

282

90

300

233

380

425

350

353

300

187

200

175

Geologicunit

code

SCKN

SCKN

PSSC

PSSC

SCKN

PSSC

LCKG

DIBS

PSSC

PSSC

PSSC

PSSC

LCKG

LCKG

PSSC

PSSC

PSSC

PSSC

SCKN

LCKG

PSSC

SCKN

PSSC

PSSC

LCKG

PSSC

PSSC

PSSC

LCKG

LCKG

SCKN

LCKG

PSSC

PSSC

LCKG

Latitude

(degrees

402340

401935

402040

401846

401756

402142

402045

402252

402024

402156

402147

402244

402412

402355

402406

402358

402406

402243

402418

402217

402140

402135

401947

402045

401938

401905

401835

402314

402042

402451

401939

401753

401753

401910

402208
tlogical Survey Ground-Water Site Inventory data base for selected wells in an

o 

o>

Brook, and Tacobs Creek drainaee basins, west-central New Tersev-Continued

uses

well

number

210293

210294

210295

210296

210297

210298

210299

210301

210302

210303

210304

210305

210306

210308

210309

210310

210312

210313

210314

210315

210316

210317

210318

210319

210321

210322

210323

210324

210325

210326

210327

210328

210329

210330

210331

Use

of

water

T

H

H

H

H

H

H

H

H

H

H

I

H

C

C

T

H

H

H

H

H

I

H

I

H

H

H

H

C

H

H

H

H

C

H

Owner

DMST. FOR ADVANCED STUDY

KIEFER

LEICHT

MCAL1NDEN, MERRTTT

MTTCHELUN

SLATER

STANIAR, H B

STONE

WECHSLER

WEINROTH.R

WOODWARD, DON

KALES NURSERY

MOUNT, GARY

EDUCATIONAL TESTING SERV

EDUCATIONAL TESTING SERV

PRINCETON UNIVERSITY

ROBERTSON.TOM

RILEY.D

MOORE, SW

COHEN

GUNN, ROBERT W

HENDERSON.JOHN

FINE, SIDNEY

DILWORTH, J R

KENNEDY, W

SELTER. E

JONES, RONALD

KLEEPER, WILLIAM

SUSSMAN REALTY CO

MILEWSKI.JOHNP

STILSON.E

REINECKE. GEORGE A

MALEC.M

ROBEXCORP

PEUKAN HOUSING INC

Local well

number or

name

1

KEIFER

LEICHT

MCAIJNDEN

MTTCHELL

SLATER

STANIAR

STONE

WECHSLER

WEINROTH

WOODWARD DOMESTIC

KALE IRRIGATION

MOUNT DOMESTIC

ETS4-NEWETS2

NEWETS3R

GUYOTHALL1

ROBERTSON DOM

RILEYDOM1

MOORE DOM

COHEN DOM

GUNN DOM

HENDERSONFARM

FINE2

DILWORTH 1

KENNEDY DOM

SELTER 1

JONES DOM

KLEEPEN DOM

PARSONS BLDG

MILEWSKI1

STILSONDOM

REINECKE 1

MALECDOM

ROBEXCORP 3

PEUKAN HOUSING

Diameter 

of open 

interval

(inches)

10

6

6

6

6

6

6

6

6

6

6

8

6

8

8

6

6

6

6

6

6

6

6

6

6

6

6

6

6

6

6

6

6

6

8

Year of

construction

1963

1978

1979

1978

1978

1983

1980

1984

1969

1979

1985

1986

1965

1957

1964

1961

1972

1970

1980

1981

1983

1985

1966

1955

1983

1966

1984

1972

1984

1978

1983

1972

1984

1975

1974

Open interval 

(feet below land

surface)

Top

45

50

40

50

50

50

62

56

42

30

50

59

51

30

51

33

30

40

50

40

50

51

30

28

52

30

52

30

52

52

50

53

52

50

31

Bottom

305

220

130

250

205

175

215

200

290

115

120

260

98

248

303

150

118

160

165

300

240

140

247

130

150

248

150

135

190

300

160

118

150

190

200

Geologicunit

code

SCKN

DIBS

PSSC

LCKG

PSSC

PSSC

PSSC

PSSC

DIBS

SCKN

PSSC

LCKG

LCKG

LCKG

LCKG

SCKN

LCKG

LCKG

DIBS

DIBS

SCKN

PSSC

DIBS

LCKG

PSSC

LCKG

LCKG

LCKG

LCKG

PSSC

PSSC

PSSC

PSSC

PSSC

LCKG

Latitude

(degre

40195

40221

40212

40243

40181

40235

40214

40202

40220

40212

40214

40194

40195

40204

40204

40204

40211

40214

40222

40221

40244

40231

40200

40205

40204

40165

40170

40170

40175

40181

40182

40182

40184

40191

40193
o

Brook, and Jacobs Creek drainaee basins, west-central New Jersev-Continued

uses

well

number

210332

210333

210334

210335

210336

210337

210338

210339

210340

210341

210342

210344

210345

210346

210347

210349

210350

210352

210353

210354

210355

210356

210357

210358

210359

210360

210365

210366

210367

210368

210369

210370

210371

210373

210374

Use

of

water

H

H

H

H

H

H

H

H

H

C

H

H

H

H

H

C

H

H

C

H

H

H

H

U

U

H

U

U

H

H

H

H

H

H

U

Owner

MORRISON, R

TOWBIN.J

MATHER. SAMUEL D

RALPH, ELIZABETH K

JACOBELLI. CARL

GRAVEN, R

BACON, WESLEY

NELSON, J

SCOZZARI, VINCENT

HOPEWELL VAL. RAQUETBALL

EDGE.L

FAHERTY.J

MAYER.RUDY

LEWELLEN.WS

O-NEILUB

SUSSMAN REALTY

GRIFFIS.EARL

ALECH.BUD

STAGE DEPOT MOTEL

GILLESPIE, RICHARD

OLMLAND.L

YU.YS

JAFFIN, CHARLES

US GEOLOGICAL SURVEY

US GEOLOGICAL SURVEY

DUPEE, SAMUEL JR

AT&T

STATE OF NJ-NJGS

HOROWITZ, MILTON

BIRCH

POLANA.JASNA

WANG.SHU-SHENG

CIGNARELLA, RICHARD

PENNINGTON WATER DEPT

MOBIL RESEARCH & DEV.

Local well

number or

name

MORRISON DOM

TOWBIN1

MATHER DOM

RALPH 1

JACOBELLI DOM

GRAVEN DOM

BACON DOM

NELSON DOM

SCOZZARI DOM

H VALLEY RAQUETBALL

EDGE1

FAHERTY DOM

MAYERDOM

LEWELLEN DOM

ONEILLDOM

ANDREWS BLDG

GRIFFISDOM

ALECHDOM

STAGE DEPOT DOM

GILLESPIE DOM

OLMLANDDOM

YUDOM

JAFFIN DOM

PRNCTN 1-BRICK RD OB

PRNCTN 2-CHILL PL OB

DUPEE 1

AT&T NORTH OBS

WASH CRSPRK HOBS

HOROWITZDOM

BIRCH DOM

BOMB SHELTER

WANGDOM

CIGNARELLA DOM

PENNINGTON WD 8

MW2

Diameter 

of open 

interval

(inches)

6

6

6

6

6

6

6

6

6

6

6

6

6

6

6

6

6

6

10

6

6

6

6

4

4

6

6

6

6

6

6

6

6

10

6

Year of

construction

1962

1972

1976

1976

1984

1979

1978

1974

1979

1978

1969

1972

1980

1973

1973

1979

1979

1982

1970

1980

1972

1979

1981

1989

1989

1970

1989

1957

1948

1984

1957

1988

1965

1989

Open interval 

(feet below land

surface)

Top

24

36

95

38

52

51

75

30

51

42

40

44

61

50

52

31

40

52

20

31

31

50

50

24

28

40

--

50

51

22

40

24

59

61

70

Bottom

142

80

170

250

164

200

270

120

200

175

460

225

200

265

125

150

100

162

100

140

125

300

250

305

439

173

99

225

70

131

300

60

360

300

600

Geologicunit

code

PSSC

PSSC

DIBS

DIBS

PSSC

PSSC

DIBS

PSSC

PSSC

PSSC

PSSC

SCKN

DIBS

DIBS

LCKG

LCKG

LCKG

PSSC

PSSC

PSSC

PSSC

LCKG

LCKG

SCKN

SCKN

PSSC

PSSC

PSSC

SCKN

SCKN

LCKG

SCKN

LCKG

PSSC

PSSC

Lati

tude

(degre

40194

40201

40202

40203

4020

40204

40204

4020

4020

4020

4021

4021

4022

4022

4020

4017

4018

4019

4021

4019

4021

4020

4020

4020

4020

4022

4021

4018

4018

4019

4020

4020

4022

4020

4020
Brook,, and Tacobs Creek drainage basins, west-central New Tersev Continued

uses

well

number

210375

210376

210377

210381

210382

210408

210409

350016

350025

350026

350028

350040

350041

350043

350047

350048

350049

350050

350051

350052

350053

350054

350055

350056

350057

350058

350059

350060

350061

350062

Use

of

water

U

N

U

R

H

N

N

U

H

H

U

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

Owner

MOBIL RESEARCH & DEV.

SOCONY MOBIL OIL COMPANY

MOBIL TECHNICAL CENTER

HOPEWELL VAL GOLF CLUB

HOPEWELL VAL GOLF CLUB

AT&T TECHNOLOGIES

AT&T TECHNOLOGIES

NJ NEUROPSYCHIATRIC

GILLJCO. CARMEN

BALDING, JOHN

N J. NEUROPSYCHIATRIC

SMITH. WILLIAM L

DEMUND. WINIFRED

JAMES, LEONARD P

KRIK, GEORGE

RYAN, GEOFFREY T

FRENCH

HAGGON, WILLIAM

MARTIN

HYDAHL

MCBRIDE, GREGORY

MCNALLY

FELMEISTER

DILLIVIO

KEIFER, DAVID

DUDEK, LARRY

VOORHEES, WILLIAM

BERGMAN, JAMES

BUCCI, EDWARD

HOISINGTON, ELEANOR M

Local well

number or

name

MW1

1

MW3

HVGCRESTROOM2

HVGC CLUBHOUSE 1

AT&T FILM CENTER

AT&T WELL 2

EIGHT

GILLICO 1

BALDING 1

SEVEN

SOMERVILLE POULTRY

DEMUND 1

DOMESTIC 1

KIRKDOM

RYANDOM

FRENCH 1

HAGGON DOM & OFC

MARTIN DOM

HYLDAHL DOM

MCBRIDE DOM

MCNALLY DOM

FELMEISTER DOM

DILLIVIO DOM 1

KEIFER DOM

DUDEK DOM

VOORHEES 762

BERGMAN DOM

BUCCI DOM

HOISINGTON DOM

Diameter 

of open 

interval

(inches)

6

10

6

-

~

6

8

10

6

6

8

6

6

6

6

6

6

6

6

6

6

6

6

6

6

6

6

6

6

6

Year of

construction

1989

1962

1989

1959

1959

1948

1960

1963

1961

1984

1958

1970

1978

1965

1983

1985

1977

1986

1984

1986

1985

1984

1983

1980

1984

1984

1984

1987

1985

1984

Open interval 

(feet below land

surface)

Top

32

30

20

25

30

12

35

42

20

50

33

52

52

21

60

32

51

52

50

50

50

60

52

31

50

50

50

63

50

50

Bottom

600

426

600

180

400

185

300

300

160

200

303

155

200

117

145

165

180

260

300

175

200

160

275

200

250

180

420

200

230

225

Geologicunit

code

PSSC

PSSC

PSSC

PSSC

PSSC

PSSC

PSSC

SCKN

LCKG

PSSC

PSSC

PSSC

LCKG

PSSC

SCKN

LCKG

PSSC

PSSC

LCKG

PSSC

PSSC

PSSC

PSSC

LCKG

PSSC

PSSC

PSSC

LCKG

LCKG

LCKG

Latitude

(degrees)

402047

402049

402052

402139

402146

402128

402135

402509

402516

402438

402510

402545

402556

402601

402520

402539

402403

402443

402620

402342

402423

402450

402406

402559

402417

402438

402421

402259

402253

402302
Table 4b. Records 

central New Jersey

from published reports for selected wells in and near the Stony Brook. Beden Brook, and Jaco

[Altitudes in feet above sea level, rounded to nearest foot; -, no data available; casing lengths and well depths rounded to nearest foot. 

Geologic-unit codes: PSSC Passaic Formation; LCKG Lockatong Formation; SCKN Stockton Formation; DIBS Diabase rocks. 

Use-of-water codes: H domestic; I industrial. 

Well number identifies the reference from which the well data were obtained:

For well data obtained from Kasabach (1966): 

The first digit in the well number is 8.

The second and third digits indicate the Township in which the well is located: 05 East Am well, 14 West Amwell. 

The fourth, fifth, and sixth digits are the well number as listed in the cited report.

For well data obtained from Vecchioli and Palmer (1962): 

The first three digits are 900. 

The fourth, fifth, and sixth digits are the well number as listed in the cited report.

For well data obtained from Widmer (1965): 

First digit is 7.

The second and third digits indicate the Township in which the well is located: 05 West Windsor, 06 Princeton, 07 Lawrence, 08 E w

The fourth, fifth, and sixth digits are the well number as listed in the cited report.]

Well

number

Use

of

water Owner

Diameter

of

casing

(inches)

Year

of

construction

Casing

length

(feet)

Depth

of

well

(feet)

Geologicunit

code

Latitude

(degrees)

Longitude

(degrees)

Mercer County

705001

705003

705007

705009

705010

705040

705048

205056

705059

705066

H

I

H

I

I

I

H

I

I

H

Design for Living

American Cyanamid #3

Public Service

Springdale Warehouse Coup.

Paradise Pool

Princeton Water Co. B-4

Boyd

Heyden Chemical Company #1

Wildeimuthtfl

Levine

6

8

6

6

8&6

13.5 & 10

6

12

1957

1958

1959

1959

1954

1930

1928

1943

1926

1930

22

30

37

37

_

--

--

82

300

67

200

320

302

84

300

135

80

SCKN

SCKN

SCKN

SCKN

SCKN

SCKN

SCKN

SCKN

SCKN

SCKN

401808

401743

401956

401928

401824

402019

401842

401937

401942

401827

744019

744024

743830

743827

743952

743806

743948

743824

743812

744007
central New Tersev C

Well 

number

Use 

of 

water

wn^f'f*- rwr-- f T-IT ir ir-r- .-irj

bntinued

Owner

Diameter 

of 

casing 

(inches)

Year 

of 

construction

Casing 

length 

(feet)

Depth 

of 

well 

(feet)

Geologicunit 

code

Latitude 

(degrees)

Longitude 

(degrees)

Mercer County-Continued

705072

706001

706004 

706005 

706007

706008

706011

706012 

706013

706014

706015

706016 

706018

706019

706020

706021

706022 

706023 

706024

706028

706030 

706033

706034 

706035

706036

706037 

706039

706040

706042

706043 

706044

706046 

706049

706051

H

H

H 

H 

H

H

H

H 

H

H

H

I 

H

H

H

H

H 

H 

H

H

H 

H

H 

H

H

I 

H

H

H

H 

H

I 

H

H

Amabile

Chin

Italian Amer. Sportsmans Club 

Italian Amer. Sportsmans Club 

Humphreys

Lambert #5

Fox

Institute for Advanced Study 

Cashvan

Miller

Miller

Princeton Water Company 

Harris

Snedaker & Son

Vancleve

Hall

Flag 

Endersky 

Schl uter

Cresswell

Sayer 

Stokes

Princeton Quaker Meeting 

Eno

Lauck

Princeton Shopping Center 

Lambert #1

Behrens

Zullig

Geherty 

Cook

Rockwood Dairy 

Tuska

Swan

6

6

6 

6 

6

8

8

6 

6

6

6

12 

6

6

6

6

6 

6 

6

6

8 

6

6 

8

--

10 

6

6

6

6 

6

6 

6

6

1950

1958

1953 

1953 

1957

1955

1957

1956 

1959

1959

1959

1958 

1959

1954

1952

1951

1952 

1952 

1949

1925

1951 

1941

1953 

1943

1947

1952 

1949

1929

1954

1952 

1952

1938 

1948

1948

45

~

20

24 

27

32

29

22 

23

23

23

36 

24

24

18

_

15

23 

28

41

53

25

21 

30

--

38

27

-.

23

52 

57

8

23

86

85

400 

115 

163

452

77

150 

110

100

85

403 

108

175

95

100

97 

137 

155

167

174 

107

91 

190

158

393 

378

70

70

75 

270

85 

109

182

SCKN

DIBS

LCKG 

LCKG 

LCKG

LCKG

LCKG

SCKN 

SCKN

SCKN

SCKN

PSSC 

LCKG

PSSC

LCKG

DIBS

LCKG 

LCKG 

LCKG

DIBS

DIBS 

SCKN

SCKN 

SCKN

SCKN

PSSC 

LCKG

DIBS

DIBS

DIBS 

DIBS

LCKG 

SCKN

LCKG

401829

402260

402208 

402210 

402225

402029

402047

401952 

401917

401906

401916

402149 

402117

402041

402132

402223

402004 

402050 

402046

402246

402221 

401937

401935 

401922

401927

402154 

402025

402207

402222

402314 

402242

402123 

401958

402013

743919

744022

743910 

743919 

743836

744205

744100

744004 

744124

744125

744112

743946 

743824

744214

744205

744256

744158 

744215 

744218

744154

744133 

744143

744042 

744041

744129

743907 

744153

744019

744018

743903 

743959

743954 

744035

744155
central New Jersey Continued

Well 

number

Use 

of 

water Owner

Diameter 

of 

casing 

(inches)

Year 

of 

construction

Casing 

length 

(feet)

Depth 

of 

well 

(feet)

Geologicunit 

code

Latitude 

(degrees)

Lon

tud

(degr

Mercer County-Continued

706054

706055 

706058

706059 

706060

706061

706062

706064

706066 

706067

 >j 706071 

**» 706072

706073

706074

706075

707001 

707004 

707005

707007 

707008

707010

707015 

707025

707026

707027

707028

707029

707030

707031

707032

707034 

707041

707048 

707049

707050

H

I 

H

H 

H

H

H

H

H 

H

H 

H

H

H

H

I 

I 

H

H 

H

H

H 

H

H

H

H

H

H

H

H

H 

H

H 

H

H

Funkhouser

Princeton Water Company 

Salzman

Pretty Bik. Corporation Lot A 

Paiker

Bower

Howcll

Davidson

Cramer & Bogert 

Bond

Lambert #4 

Lambert #3

Lambert #2

Yates

Kilgore

Education Testing Service 

Education Testing Service 

Woods

Thompson 

Rusling

Cashvan

Campbell 

LaPlaca

Schleuter

Goldstine

Beacrafl

Hannah

Cowan

Katzenbach

Ballon

Goodridge 

Newman

Raymond 

Penrose

Button's Dairy

6

10 

6

6 

6

6

6

6

6 

6

8 

8

6

6

6

12 & 8 

12&8 

8&6

8&6 

8&6

6

6 

8&6

8

6

8&6

6

6

6

-

6

6 

6

8

1952

1915 

1947

1928 

1910

1952

1938

1951

1947 

1948

1949 

1948

1949

1926

1953

1957 

1956 

1956

1954 

1954

1959

1956 

1951

1951

1950

1951

1929

1929

1941

1930

1938 

1947

1953 

1953

1948

23

25

24

34

33

22

22

27

15

30

45 

50 

21

18 

28

38

32 

21

24

22

22

21

24

24

--

28

44 

35

26

141

304

87

140 

186

156

181

92

50 

202

267 

3%

287

160

252

248 

223 

350

100 

169

146

80

80

337

103

130

130

119

199

201

185 

90

106 

100

250

LCKG

SCKN 

DIBS

LCKG 

LCKG

LCKG

PSSC

PSSC

DIBS 

LCKG

LCKG 

LCKG

LCKG

LCKG

PSSC

LCKG 

LCKG 

LCKG

LCKG 

LCKG

SCKN

SCKN 

LCKG

LCKG

LCKG

LCKG

LCKG

LCKG

LCKG

LCKG

LCKG 

LCKG

LCKG 

LCKG

LCKG

402210

401934 

402216

402149 

402113

402214

402150

402144

402315 

402213

402015 

402017

402019

402150

402141

402112 

402105 

401945

401846 

401831

401853

401749 

402025

402036

401954

402021

402053

402038

401952

402042

402014 

401828

401845 

401854

401805

7438

7439

7440

7441

7438

7438

7438

7438

7439

7438

7441

7441

7441

7441

7438

7443

7443

7443

7442

7443

7441

7442

7443

7442

7443

7442

7442

7442

7442

7442

7442

7444

7442

7442

7444
central New Jersey-Continued

Well

number

Use

of

water Owner

Diameter

of

casing

(inches)

Year

of

construction

Casing

length

(feet)

Depth

of

well

(feet)

Geologicunit

code

Latitude

(degrees)

Longitude

(degree

Mercer County Continued

707057

707058

707059

707060

707061

707062

707065

707066

707067

707072

707080

707081

707091

707096

707097

707099

708001

708002

708003

708005

708006

708007

708008

708009

708010

708016

708030

708033

708035

708037

708038

708040

708041

708043

708050

H

H

H

H

H

H

H

H

H

H

I

H

H

H

H

H

H

H

H

H

H

H

H

H

I

H

H

H

H

I

I

H

H

H

H

Lauck

Luccarelli

Prickett

Hazeltine

LaPlaca

Kelly

Hutchinson

Hough ton

Mitchell

Hough ton

Clarksville Diner

Nadi

Fackler

Maruca

Lonska

Lovero

Penlee

Norton on

Jacobella

Barber

Fraulino

Dowdell

Walker

Duralski

Hampton Hill WC

George Brewster, Inc.

Lambert

Dowdell

Huff

Mercer County Airport

US Navy - Air Testing Station

Scott

Van Horn

Kittell

Jackson

6

6

4

6

6

6

6

6

6

6

8

6

6

6

6

6

6

6

6

8&6

10,8 & 6

10&8

8&6

6

8

8&6

6

6

6

8

8

6

6

6

6

1950

1952

1934

1949

1951

1952

1952

1953

1950

1934

1960

1929

1935

1961

1961

1962

1956

1954

1954

1949

1954

1955

1954

1956

1955

1959

1948

19--

1951

1943

1943

1954

1951

1951

1940

23

17

28

--

18

24

31

22

-

41

40

23

22

26

22

6

21

21

22

23

20

45

35

25

20

23

21

-

27

60

198

115

204

105

76

131

149

125

160

123

85

73

104

100

95

145

133

177

125

176

113

120

156

100

250

90

111

84

72

232

603

92

85

90

67

LCKG

SCKN

PSSC

LCKG

LCKG

PSSC

LCKG

LCKG

LCKG

LCKG

SCKN

SCKN

SCKN

LCKG

LCKG

LCKG

LCKG

LCKG

LCKG

LCKG

LCKG

LCKG

LCKG

LCKG

SCKN

LCKG

LCKG

SCKN

SCKN

SCKN

SCKN

SCKN

SCKN

SCKN

SCKN

401904

401913

402041

401942

402018

402059

401903

401849

401858

401854

401750

401725

401833

402006

401837

401801

401643

401714

401639

401623

401629

401633

401603

401629

401647

401614

401551

401632

401650

401700

401609

401640

401636

401647

401643

744214

744154

744328

744235

744303

744234

744248

744230

744249

744341

744102

744129

744224

744206

744417

744513

745044

745016

745057

745109

745060

745050

745044

745032

744644

744923

745032

745105

744822

744853

744830

744654

744710

744655

744716
Ol

central New Tersev Continued

Well

number

Use

of

water Owner

Diameter

of

casing

(inches)

Year

of

construction

Casing

length

(feet)

^ -**L--^_, **-,*** . L«J_

Depth

of

well

(feet)

__f*f^ntf~~f Iim^_ ^

Geologicunit

code

Latitude

(degrees)

Longitude

(degrees

Mercer County-Continued

708064

708073

708075

708087

708093

708094

708095

708100

708101

708102

708103

708106

708107

708108

708111

708112

708115

708116

708118

708120

708121

708123

708124

708125

709001

709002

709003

709004

709005

709006

709007

709008

709011

709013

709014

H

H

H

H

I

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

Buck

Kreiguer

Holmes

Peterson

State Hospital Dairy Farm

Harm on

Klim

McElwee

Trinity Church, Trenton

Russo

Landwehr Restaurant

Calvanelli

Kotovach

Perline

Brophy

Lentini

Tren-Deli Con

McLaughlin

Lentini & Grice

Genecey Company

Genecey Company

Statler Buildings

Jacobelli

Statler Buildings

Lake

McKelvy

Hodnett

Newbanks, Inc.

Hod son Hart

Harbourton Cemetery

Peimington Builders #2

Peimington Builders #1

Nickerson

Yazujian

Doll

6

6

6

6

12&8

6

6

6

--

6

6

6

6

6

8&6

8&6

6

8&6

6

6

6

6

6

6

8&6

6

8&6

8

10&6

6

8&6

8&6

8&6

6

6

1956

1952

1951

1953

1944

1948

1948

1951

1921

1956

1952

1951

1952

1952

1957

1958

1958

1957

1956

1956

1956

1957

1957

1957

1954

1956

1955

1960

1954

1960

1960

1954

1954

1955

1955

34

--

22

30

21

29

16

--

20

_

22

22

23

21

22

--

26

21

21

22

33

21

46

27

55

«

23

25

24

23

21

24

20

95

104

62

123

436

105

110

142

123

153

140

72

80

81

90

70

200

95

90

135

148

115

110

110

90

153

67

85

173

85

100

108

184

404

175

SCKN

LCKG

LCKG

LCKG

LCKG

LCKG

SCKN

LCKG

LCKG

LCKG

LCKG

LCKG

LCKG

LCKG

SCKN

SCKN

LCKG

LCKG

SCKN

LCKG

LCKG

LCKG

LCKG

LCKG

DIBS

SCKN

DIBS

SCKN

DIBS

LCKG

LCKG

LCKG

LCKG

DIBS

DIBS

401549

401622

401646

401636

401612

401660

401550

401649

401635

401633

401648

401658

401650

401648

401710

401703

401616

401624

401651

401708

401651

401624

401616

401712

402411

402238

402240

402215

402003

402101

402049

402049

401912

401952

401958

744934

745054

745037

745105

744933

745007

744913

745030

745059

745039

745048

745014

745014

745007

744659

744653

745031

744925

744707

745013

745014

745047

745037

745023

744821

744744

744619

744759

745132

745105

744816

744806

745123

745215

745214
lected wells in and near the Stony Brook. B< Bj

central New Jersey-Continued

Well

number

Use

of

water Owner

Diameter

of

casing

(inches)

Year

of

construction

Casing

length

(feet)

Depth

of

well

(feet)

Geologicunit

code

Latitude

(degrees)

Longitude

(degrees)

Mercer County Continued

709015

709016

709017

709019

709020

709025

709026

709027

709028

709029

709030

709032

709033

709034

709035

709036

709037

709038

709039

709040

709041

709042

709043

709044

709046

709047

709048

709049

709050

709051

709052

709053

709054

709055

709057

H

H

H

H

H

I

H

H

H

H

H

I

H

H

H

H

H

H

H

I

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

Grove

Whvte

Anderson

Hill

Hill

Anderson

Raswieler

MacDonald

Ogden Nursing Home

Howe Nurseries

Young

Howe Nurseries

Himes

Doherty

Barbour

Trenton Banking Company

Vickers

Blue Ribbon, Inc.

Toten

Blue Ribbon Water Company

Badinski #2

Shauer

Brookstone Builders

Pomeroy

Philco Company

Queenston Builders

Queenston Builders

Queenston Builders

Queenston Builders

Lane Farms, Inc.

Hutchinson

Potts

Toten

BhckweU

Carom

8&6

8&6

8&6

6

6

6

8&6

8&6

6

8&6

8&6

8&6

6

8&6

8

8&6

6

8&6

4&6

10&8

6

8&6

10&6

6

8&6

6

6

6

6

8

6

6

6

6

6

1957

1955

1960

1958

1958

1955

1955

1957

1961

1957

1955

1957

1954

1954

1961

1958

1955

1957

1954

1956

1961

1954

1960

1957

1957

1960

1960

1960

1960

1961

1956

1962

1962

1962

1951

21

30

24

22

22

30

24

21

24

22

23

23

23

23

32

21

21

23

80

35

24

23

63

36

33

24

27

24

24

46

22

29

21

34

15

190

262

60

300

380

138

124

112

200

205

240

228

230

142

150

147

80

100

202

159

92

150

91

211

100

100

125

185

116

373

85

89

125

350

130

LCKG

LCKG

PSSC

LCKG

LCKG

PSSC

PSSC

PSSC

LCKG

PSSC

PSSC

PSSC

PSSC

LCKG

LCKG

LCKG

LCKG

LCKG

LCKG

SCKN

LCKG

LCKG

DIBS

SCKN

DIBS

PSSC

PSSC

PSSC

PSSC

LCKG

LCKG

LCKG

LCKG

LCKG

PSSC

401913

401905

401924

401708

401708

402035

402019

401932

401728

401915

401907

401913

401907

401825

401704

401825

401741

401743

401737

401724

402008

402419

402221

402429

402212

402156

402156

402154

402147

402202

401825

402227

401705

401701

402234

745148

745137

744857

745126

745126

744544

744615

744603

745138

744710

744652

744635

744704

744742

745124

744717

744626

744647

744648

744622

744904

744528

744455

744456

744315

744554

744547

744542

744546

744942

744529

745022

745107

745112

744413
central New Tersev Continued

Well

number

Use

of

water Owner

Diameter

of

casing

(inches)

Year

of

construction

Casing

length

(feet)

Depth

of

well

(feet)

Geologicunit

code

Latitude

(degrees)

Longitude

(degrees)

Mercer County Continued

709058

709059

709060

709064

709065

709066

709067

709068

709069

709070

709071

709072

709073

709074

709075

709076

709077

709078

709079

709080

709081

709082

709083

709084

709086

709087

709088

709089

709093

709094

709095

709104

709105

709106

709107

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

I

H

H

H

H

Voorhees

CoUins

Badinski#3

Barna

Udy

Scarpati

Pierson

Snyder

VanSant

LaCross

Basil DiGtriseppe

Stover - now Wierdsma

Mulfoid

Wombwell

Bdlot

Choitey

Conoven

Cole

Chafey

Capner

Novohflsky

VanSant

Basil DiGiriseppe

Valenu

Denaci

Brooks

Totten, Robert

Swick

Kostar

Wood

National Dairy Products Co.

Panacek

Fern wood Mercer

Backus

Seckle - now Andenon

6

8

6

6

6

6

6

6

6

6

6

8

6

6

6

6

6

6

6

6

6

6

6

6

6

6

6

6

6

8

6

6

6

6

1948

1953

1961

1949

1958

1948

1952

1952

1952

1961

1961

1941

1951

1951

1950

1951

1951

1950

1949

1948

1949

1949

1961

1949

1949

1948

1961

1948

1950

1951

1929

1955

1953

1953

1956

23

21

24

53

24

20

20

10

21

26

24

32

22

26

31

32

18

53

25

34

22

23

25

40

20

20

42

20

24

66

-

155

208

100

93

110

282

81

82

139

100

163

168

75

114

140

118

76

271

75

140

119

79

100

75

214

129

124

190

151

130

188

110

62

85

150

PSSC

SCKN

LCKG

DIBS

SCKN

DIBS

SCKN

LCKG

PSSC

PSSC

PSSC

SCKN

DIBS

LCKG

SCKN

PSSC

LCKG

SCKN

SCKN

PSSC

LCKG

DIBS

PSSC

DIBS

LCKG

SCKN

LCKG

DIBS

LCKG

LCKG

PSSC

SCKN

LCKG

LCKG

LCKG

402344

402438

402014

402247

402418

402454

402313

402418

402352

401841

401841

402246

402235

402423

402350

402343

402460

402327

402408

402346

402427

402238

401836

402256

402439

402434

401825

402227

401727

401727

401806

402105

401731

401659

402424

744410

744447

744905

744637

744448

744710

744711

744617

744426

744609

744842

744723

744634

744531

744554

744450

744511

744653

744519

744441

744627

744639

744841

744642

744632

744430

744725

744654

744911

744903

744808

745022

744654

745120

744519
00

central New Terscv Continued

WeU

number

Use

of

water Owner

Diameter

of

casing

(inches)

Year

of

construction

Casing

length

(feet)

Depth

of

well

(feet)

Geologicunit

code

Latitude

(degrees)

Longitude

(degrees)

Mercer County Continued

709108

709109

709111

709113

709114

709115

709117

709118

709119

709120

709121

709122

709123

709124

709125

709126

709127

709129

709130

709131

709132

709133

709134

709136

709137

709138

709139

709140

709142

709143

709144

709145

709149

709150

709151

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

Bard

NJCED (Bear Tavern)

NJCED (Washington Grove)

Postley

Cioppi

Lake

Holcomb

Schire Deer Club

Hunt, Jr.

Engle

Meredith

City Service Oil Company

Culten

Keffer

Beemen

Hilbert

Lauter

Cooley

Ehret

Hayes

Jury

lUian

Antrobus

Bueschel

Banacei

Winkler

Wilson

Hoffiman

Van Dyke

Kettenbeig & son

Kettenbeig & Son

Tizik

Dayizak

Pierson

Katzenback

6

6

6

8

6

6

6

6

6

6

6

6

6

6

6

6

6

--

6

6

6

6

6

6

6

6

6

6

6

6

6

6

6

6

6

1950

1950

1929

1953

1956

1957

1958

1959

1960

1956

1956

1957

1949

1949

1948

1956

1950

1909

1951

1948

1948

1948

1958

1959

1953

1952

1951

1950

1950

1961

1961

1948

1959

1956

1956

22

30

40

32

20

43

27

20

25

24

23

26

24

42

21

21

22

--

20

22

21

22

20

22

23

43

21

26

25

20

24

23

46

28

145

165

144

397

68

66

65

65

250

173

150

140

135

215

165

124

160

121

150

181

143

121

200

170

110

204

119

110

50

100

100

104

90

52

115

PSSC

LCKG

PSSC

PSSC

LCKG

DIBS

LCKG

DIBS

LCKG

LCKG

PSSC

PSSC

PSSC

LCKG

LCKG

LCKG

LCKG

PSSC

LCKG

LCKG

LCKG

PSSC

DIBS

DIBS

LCKG

PSSC

PSSC

PSSC

DIBS

DIBS

LCKG

PSSC

SCKN

SCKN

SCKN

401747

401834

401749

401732

402053

402414

402256

402452

402234

402035

402019

401817

401804

401734

401825

402243

401826

401747

401651

401828

401827

401808

401950

402013

401655

401849

401934

401901

402028

402217

402212

401836

401717

402313

402318

744848

745050

745207

745056

745107

744813

744940

744700

745008

744416

744529

744659

745130

745141

745028

745046

745042

745152

745114

745032

745101

745124

745136

745227

745118

744716

744805

744812

744932

744702

744702

744725

744635

744654

744718
central New Tersev Continued

WeU

number

Use

of

water Owner

Diameter

of

casing

(inches)

Year

of

construction

Casing

length

(feet)

Depth

of

well

(feet)

Geologicunit

code

Latitude

(degrees)

Longi

tude

(degree

Mercer County-Continued

709152

709153

709154

709155

709156

709163

709164

709165

709166

709167

709168

709169

709170

709172

709173

709174

709179

709188

709191

709194

709195

709196

709197

709198

709199

709200

709201

709203

709204

709206

709207

709208

709210

709211

709212

H

H

H

H

H

H

H

H

H

H

H

H

H

I

I

I

I

H

H

H

H

H

H

H

H

H

H

H

H

I

I

I

H

H

H

Salnaggio

Comstock Architect

Prozeralick

Perry Preckwinkle

Rockwell

Reed, Jr.

Permington Quarry Company

Oldis

Palmer Nurseries

Holler

Himmekbock

Helpers

Hoagland

Permington Boro#l Perm. Mt.

Permington Boro #2 Perm. Mt.

Permington Boro #3 Del Ave

Permington Boro #8 Del. Ave.

Brookside Inn

Kurylo

Bind

Klein

Betjemaim

Kessler

Czaiko

Wilson

Maddox

Rose

Holden

Roebling

Pern Brook Club

Western Electric Company

Western Electric Company

Fauseet

Peimington Grance

Brace, Jr.

6

6

6

6

6

6

6

6

6

6

6

6

6

6

6

10

10

6

6

6

6

6

6

6

6

6

6

6

6

8

8

8

6

6

6

1948

1956

1955

1956

1938

1949

1951

1949

1929

1942

1953

1951

1950

1907

1907

1927

1954

1931

1951

1953

1953

1953

1936

1950

1936

1932

1948

1950

1957

1960

1957

24

1956

1955

41

22

31

20

31

31

39

22

130

30

21

20

20

~

57

43

--

40

22

14

22

--

37

116

64

23

26

35

42

150

22

22

126

137

32

120

127

171

45

250

225

256

100

109

128

186

159

657

178

%

100

70

150

150

112

126

249

180

LCKG

110

262

250

300

501

SCKN

126

120

PSSC

SCKN

DIBS

SCKN

PSSC

DIBS

PSSC

PSSC

PSSC

PSSC

PSSC

PSSC

LCKG

PSSC

PSSC

PSSC

PSSC

LCKG

LCKG

DIBS

DIBS

DIBS

PSSC

LCKG

LCKG

LCKG

402121

PSSC

LCKG

PSSC

PSSC

PSSC

402245

PSSC

PSSC

401837

402301

402406

402204

401951

402058

402102

401821

402112

402022

401840

402012

402044

402046

402046

401944

402003

402259

402208

402039

401958

401958

402006

402133

402046

402056

745132

402032

402113

402005

402138

402136

744756

402052

401945

744731

744736

744819

744855

744653

744919

744805

744914

744535

744501

744716

744749

744753

744847

744847

744751

744702

744913

745102

744935

745119

745204

745021

745100

745113

74512

236

745134

74512

744729

74434

74433

246

74474

74455
ells in and near the Stony Brook. Bcden Brook, and Jac

central New Jersey-Continued

Well

number

Use

of

water Owner

Diameter

of

casing

(inches)

Year

of

construction

Casing

length

(feet)

Depth

of

well

(feet)

Geologicunit

code

Latitude

(degrees)

Longi

tude

(degree

Mercer County Continued

709213

709214

709215

709218

709221

709222

709223

709227

709229

709230

709243

709244

709245

709246

709247

709248

709249

709253

709263

709289

709290

709293

709295

7092%

709297

709302

709303

709304

709334

709339

709341

709342

709345

709346

709348

H

H

H

I

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

I

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

Nelson

Nelson

Knowlton

Smith Machine Company

Martin

Tobiason

Burton

Schometzer

VonSchmidi

Bolz

Haldeman

Fabian

Funeisn

DiGaetano

Appelgate

Anderson

DiCocco, Honey Brock. Drive

Dolphin Shores

Narozniak

Washington Cross. Park Est

Piers on

VanKmanvich

Balain

Panecek

Roman

Utt

Expanded Living Search Avenue

McVeigh, Joseph

Wilson

Atlantic Gas Station

Murray

Neidercr

Shestko

Niewojna

Fosbrook

6

6

6

6

6

6

6

6

6

6

6

6

6

8

6

6

6

6

6

6

6

6

6

6

6

6

6

6

6

6

6

8

6

6

6

1955

1955

1955

1939

1951

1949

1950

1950

1951

1947

1951

1952

1950

1952

1951

1961

1961

1962

1949

1961

1951

1951

1950

1955

1956

1960

1961

1961

1949

1939

1949

1954

1961

1961

1961

21

22

32

-

39

34

21

22

30

27

21

21

28

21

30

22

25

34

31

20

22

20

23

22

31

12

22

--

43

25

28

22

26

115

131

150

150

148

184

85

120

71

133

91

95

130

114

135

250

148

124

111

500

143

130

132

110

125

118

140

200

125

105

115

85

130

93

300

PSSC

PSSC

PSSC

PSSC

LCKG

LCKG

LCKG

LCKG

PSSC

LCKG

LCKG

PSSC

PSSC

PSSC

PSSC

DIBS

PSSC

PSSC

PSSC

PSSC

PSSC

PSSC

PSSC

SCKN

LCKG

DIBS

PSSC

DIBS

LCKG

LCKG

DIBS

DIBS

LCKG

LCKG

LCKG

402007

402009

402012

402340

402226

402049

402227

401957

401807

401743

402058

401824

401854

401849

401941

402018

402040

401832

401806

401839

401902

401944

401908

402113

401914

401955

401835

401951

401826

401831

402007

401958

401826

401948

401901

744537

744526

744514

744523

744912

744759

744938

744758

744732

745136

744755

744621

74485

74472

744909

745301

74443

744603

744724

745034

74511

74485

74471

74500

745134

74512

74473

74515

74501

74472

74511

74514

74510

74492

74521
00

central New Jersey Continued

.Wen

number

Use

of

water Owner

Diameter

of

casing

(inches)

Year

of

construction

Casing

length

(feet)

Depth

of

well

(feet)

Geologicunit

code

Latitude

(degrees)

Longitude

(degrees

Mercer County Continued

709349

709350

709351

709352

709353

709354

709355

709356

709357

709358

709360

709361

709362

709363

709364

709365

709366

709367

709368

709369

709373

709375

709376

709378

709379

709380

709381

900004

900005

900006

900009

900010

900011

900012

900025

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

I

H

H

H

H

H

H

H

H

H

H

H

H

Potts (Howe Tract)

Bayard

Zigleniski

Kiefer

Koppach

Poleski

Whitcraft

Princeton Manor Construction

Thompson

Hunt - Builder

Bonano

Lord

Maul

Mudge

Mudge

Maul

Donigan, Jr.

Kerr

Moticha

Perlee - Orchard Avenue

Weitzman

DiCocco

Hopewell Borough Water Co.

Colonial Construction Company

Colonial Construction Company

Colonial Construction Company

Strano

Power

Hinkle

Majeski

Bear

Hansen

Arch

Sheridan, Jr.

Sutphen

6

6

6

6

6

6

6

6

6

6

6

6

6

6

6

6

6

6

6

6

6

6

6

6

6

6

6

6

6

6

6

6

6

6

6

1961

1961

1961

1957

1959

1957

1956

1959

1956

1957

1957

1961

1961

1960

1961

1961

1957

1958

1961

1956

1958

1960

1908

1958

1958

1958

1961

1953

1957

1953

1952

1954

1952

1954

1953

26

30

21

76

22

32

24

20

24

21

21

23

23

20

20

21

22

34

25

20

21

24

30

24

24

23

27

24

22

22

22

29

22

25

37

108

165

111

95

90

70

82

175

80

63

130

85

100

49

48

287

90

150

222

101

135

122

362

100

130

80

140

160

103

138

95

100

60

95

59

PSSC

PSSC

PSSC

DIBS

PSSC

DIBS

LCKG

PSSC

PSSC

DIBS

LCKG

LCKG

LCKG

LCKG

LCKG

PSSC

LCKG

PSSC

LCKG

LCKG

LCKG

PSSC

SCKN

PSSC

PSSC

PSSC

LCKG

PSSC

PSSC

PSSC

PSSC

DBS

LCKG

LCKG

DIBS

401916

402058

401947

402213

402222

402215

402437

402220

402256

402230

402308

402253

402242

402228

402222

401918

401751

401906

402212

401741

401726

402101

402349

402152

402150

402150

401728

401913

401860

401820

402020

402113

402220

402220

402233

744649

744647

744638

744421

744420

744427

744510

744332

744529

744536

744738

744952

745009

745007

745006

745221

744639

744658

744955

744635

744643

744541

744544

744535

744526

744517

744849

745127

745220

745113

745113

744927

745140

745047

744327
CD

ro

central New Jersey Continued

Well

number

Use

of

water Owner

Diameter

of

casing

(inches)

Year

of

construction

Casing

length

(feet)

Depth

of

well

(feet)

Geologicunit

code

Latitude

(degrees)

Longitude

(degrees

Mercer County Continued

900028

900030

900032

900033

900036

900044

900045

900066

900106

900108

900109

900112

H

H

H

H

H

H

H

I

H

H

H

H

Kianka

Western Electric Co., Inc.

Gulf Oil Company

Wicoff

Smith

Mraz

Kuller

Princeton Water Company

Reside

Underwood

Smith

Martin

6

6

6

6

6

6

6

12

6

6

6

6

1953

1948

1958

1953

1956

1954

1953

1945

1957

1950

1952

1952

23

12

35

22

32

22

22

69

23

22

20

24

100

185

150

94

105

125

135

300

100

133

220

80

PSSC

PSSC

PSSC

PSSC

PSSC

PSSC

PSSC

SCKN

PSSC

LCKG

LCKG

LCKG

402153

402127

402127

402047

401953

401927

402020

402020

401807

401727

401713

401713

744540

744353

744753

744807

744940

744540

744540

743807

744753

744900

745020

744647

Hunterdon County

805004

805012

805014

805031

805034

805035

805036

805038

805039

805045

805046

805049

805062

805063

805064

805065

805066

805067

805069

805071

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

Parrenzan

Alien, Jr.

Marino

Franke

Halychyn

Burton

Hoffman

Hoffman

Blomquist

Denmon

Smith

Palmatier

Ostrowski

Hannah

LaRowe

Adams

Cvetan

Siolli

Hart

Kresmer

6

6

6

6

6

6

6

6

6

6

6

6

6

6

6

6

6

6

6

6

1948

1951

1950

1948

1950

1954

1952

1947

1947

1954

1957

1954

1961

1962

1961

1962

1962

1962

1963

1961

34

32

37

25

28

40

15

13

20

18

14

24

23

22

23

23

23

43

20

12

154

226

351

100

99

48

100

42

119

55

103

88

202

90

102

93

305

58

193

112

LCKG

PSSC

DIBS

PSSC

PSSC

DIBS

DIBS

DIBS

DIBS

DIBS

DIBS

LCKG

DIBS

PSSC

DIBS

LCKG

LCKG

LCKG

LCKG

LCKG

402551

402614

402516

402522

402407

402348

402358

402401

402427

402435

402423

402552

402427

402411

402424

402534

402538

402358

402318

402539

744820

744806

744728

745121

745107

744917

744941

744934

744942

745112

744833

744746

745125

745119

745121

744859

744844

744840

744934

744732
Oo

CO

central New Tersev Continued

Well

number

Use

of

water Owner

Diameter

of

casing

(inches)

Year

of Casing

construe- length

tion (feet)

Depth

of

well

(feet)

Geologicunit

code

Latitude

(degrees)

Longitude

(degrees)

Hunterdon County-Continued

814030

814034

814035

814036

814042

814043

814044

814061

814070

814071

814072

814074

814075

814076

814077

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

Roebling

Yaid

Gayda

Skibinsky

S. Hunterdon Regional H.S.

Kollmer, Jr.

Steinmetz

Pawljuch

Arico

Hanley

Holcombe No. 1

Cripps

Mahan

Stoy

Kurylo

6

6

6

6

6

6

6

6

6

6

6

6

6

6

6

1932

1949

1949

1932

1958

1954

1957

1951

1961

1962

1962

1962

1962

1962

1954

32

60

-

26

19

22

20

23

18

30

18

24

21

24

127

129

70

108

250

97

200

100

100

94

105

110

48

125

71

LCKG

PSSC

PSSC

PSSC

PSSC

DIBS

DIBS

PSSC

DIBS

DIBS

DIBS

DIBS

DIBS

PSSC

DIBS

402119

402247

402452

402404

402316

402304

402257

402341

402321

402330

402356

402301

402248

402242

402405

745151

745201

745144

745119

745331

745254

745252

745047

745307

745257

745203

745259

745228

745222

745151

814083 Marino 1962 22 97 LCKG 402153 745212