U.S. DEPARTMENT OF THE INTERIOR

U.S. GEOLOGICAL SURVEY

Water-Resources Investigations Report 00–4152

Geology, Hydrology, and Ground-Water Quality of 

the Galena-Platteville Aquifer in the Vicinity of the 

Parson’s Casket Hardware Superfund Site, 

Belvidere, Illinois

In cooperation with the Illinois Environmental Protection Agency
Geology, Hydrology, and Ground-Water Quality of 

the Galena-Platteville Aquifer in the Vicinity of the 

Parson’s Casket Hardware Superfund Site, 

Belvidere, Illinois

By Robert T. Kay

De Kalb, Illinois

2000

Water-Resources Investigations Report 00–4152

U.S. DEPARTMENT OF THE INTERIOR

U.S. GEOLOGICAL SURVEY

In cooperation with the Illinois Environmental Protection Agency
U.S. DEPARTMENT OF THE INTERIOR

BRUCE BABBITT, Secretary

U.S. GEOLOGICAL SURVEY

Charles G. Groat, Director

The use of firm, trade, and brand names in this report is for identification purposes only and does

not constitute endorsement by the U.S. Geological Survey.

For additional information write to:

District Chief

U.S. Geological Survey

221 North Broadway Avenue

Urbana, IL 61801

Copies of this report can be purchased from:

U.S. Geological Survey

Branch of Information Services

Box 25286

Denver, CO 80225-0286
Contents III

CONTENTS

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

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

Purpose and Scope....................................................................................................................................................... 3

Acknowledgments ....................................................................................................................................................... 3

Geology ................................................................................................................................................................................. 4

Hydrology.............................................................................................................................................................................. 13

Hydraulically Active Features ..................................................................................................................................... 14

Water Levels ................................................................................................................................................................ 15

Hydraulic Properties .................................................................................................................................................... 23

Ground-Water Quality ........................................................................................................................................................... 25

Volatile Organic Compounds....................................................................................................................................... 25

Natural Attenuation Parameters................................................................................................................................... 29

Summary and Conclusions .................................................................................................................................................... 32

References Cited.................................................................................................................................................................... 33

FIGURES

1. Map showing location of study area, boreholes, and water-supply wells in the vicinity of the Parson’s 

Casket Hardware Superfund site, Belvidere, Illinois.................................................................................................. 2

2. Generalized geologic column showing stratigraphy and hydrogeologic units in the vicinity of the Parson’s 

Casket Hardware Superfund site................................................................................................................................. 5

3-7. Diagrams showing natural-gamma, short-normal resistivity, fluid temperature, fluid-column resistivity, 

acoustic-televiewer, and flowmeter logs; stratigraphy; horizontal hydraulic conductivities; and total 

concentration of volatile organic compounds in the test intervals isolated with a packer assembly for 

boreholes in the vicinity of the Parson’s Casket Hardware Superfund site:

3. Borehole G124GP.............................................................................................................................................. 7

4. Borehole G130GP.............................................................................................................................................. 8

5. Borehole G133GP.............................................................................................................................................. 9

6. Borehole G134GP.............................................................................................................................................. 10

7. Borehole G136GP.............................................................................................................................................. 11

8-12. Diagrams showing:

8. Packer assembly and ground-water sampling pump in a borehole .................................................................... 17

9. Water-level altitude in wells G124GPD, G133GP, G134GPD, and G136GPD in the vicinity of the Parson’s 

Casket Hardware Superfund site, February 4-28, 2000 ..................................................................................... 18

10. Pumping totals for wells 00295 and 00296 combined and well BMW6 in the vicinity of the Parson’s 

Casket Hardware Superfund site, February 4-28, 2000 ..................................................................................... 19

11. Water-level altitude in wells G124GPD, G133GP, G134GPD, and G136GPD in the vicinity of the 

Parson’s Casket Hardware Superfund site, February 6-19, 2000....................................................................... 20

12. Water-level altitude in wells G124GPS, G134GPS, and G136GPS in the vicinity of the Parson’s 

Casket Hardware Superfund site, February 4-28, 2000 ..................................................................................... 21

13. Map showing concentration of trichloroethene in the deep unconsolidated aquifer in the vicinity of the 

Parson’s Casket Hardware Superfund site .................................................................................................................. 28

14. Diagram showing reductive dechlorination sequence for chlorinated ethenes........................................................... 29
IV Contents

TABLES

1. Borehole and well information, altitude of top of bedrock, and transmissivity data in the vicinity of the 

Parson’s Casket Hardware Superfund site, Belvidere, Illinois ............................................................................... 4

2. Altitude of subhorizontal fractures identified from televiewer logs in selected boreholes in the vicinity of the 

Parson’s Casket Hardware Superfund site .............................................................................................................. 13

3. Water levels measured during testing with a packer assembly under approximately hydrostatic conditions 

in the vicinity of the Parson’s Casket Hardware Superfund site, September 1999 ............................................... 16

4. Results of slug testing in test intervals isolated with a packer assembly in the vicinity of the Parson’s 

Casket Hardware Superfund site............................................................................................................................. 24

5. Results of analysis for volatile organic compounds in samples from test intervals isolated with a packer 

assembly in the vicinity of the Parson’s Casket Hardware Superfund site, September 1999................................. 26

6. Results of monitored natural attenuation parameter analyses in samples from test intervals isolated with a 

packer assembly in the vicinity of the Parson's Casket Hardware Superfund site, September 1999 ..................... 27
Contents V

CONVERSION FACTORS, VERTICAL DATUM, AND ABBREVIATED WATER-QUALITY UNITS

Temperature in degrees Celsius (°C) may be converted to degrees Fahrenheit (°F) as follows:

°F = (1.8 × °C) + 32

Sea level: In this report, "sea level" refers to the National Geodetic Vertical Datum of 1929 (NGVD

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.

Altitude, as used in this report, refers to distance above or below sea level.

*Hydraulic conductivity: Foot per day is the mathematically reduced term of cubic foot per day

times foot per square foot of aquifer cross-sectional area.

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

foot of aquifer thickness [(ft3

/d)/ft2]ft. In this report, the mathematically reduced form, foot squared

per day (ft2/d), is used for convenience.

Abbreviated water-quality units used in this report: Chemical concentration is given in metric

units. Chemical concentration is given in micrograms per liter (μg/L). Micrograms per liter is a unit

expressing the concentration of chemical constituents in solution as weight (micrograms) of solute

per unit volume (liter) of water. One thousand micrograms per liter is equivalent to one milligram

per liter (mg/L).

Abbreviations

μS/cm microSiemens per centimeter

mg/L milligrams per liter

μg/L micrograms per liter

Multiply By To obtain

Length

foot (ft) 0.3048 meter

mile (mi) 1.609 kilometer

Flow rate

gallon per minute (gal/min) 3.7685 liters per minute

Hydraulic conductivity*

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

Transmissivity**

foot squared per day (ft2/d) 0.09290 meter squared per day 
Introduction 1

Geology, Hydrology, and Ground-Water Quality of 

the Galena-Platteville Aquifer in the Vicinity of the 

Parson’s Casket Hardware Superfund Site, 

Belvidere, Illinois

By Robert T. Kay

Abstract

The geology, hydrology, and distribution 

of contaminants in the Galena-Platteville aquifer 

in the vicinity of the Parson’s Casket Hardware 

Superfund site in northeastern Belvidere, Ill., 

were characterized on the basis of data collected 

from boreholes using geophysical logging and 

packer assemblies. Horizontal flow in the GalenaPlatteville aquifer is affected by a network of 

subhorizontal fractures that are concentrated in the 

weathered part of the bedrock, vugs and fractures 

present from the bottom of the weathered bedrock 

to the top of a shaley layer at about 662 ft (feet) 

above sea level, and through a widespread subhorizontal fracture at about 524 ft. Inclined fractures 

provide pathways for vertical flow within the 

Galena-Platteville aquifer. Some fractures and 

flow pathways appear to be affected by the 

stratigraphy of the Galena-Platteville deposits.

Water-level data indicate the potential for 

downward flow within the Galena-Platteville 

aquifer. During periods when pumping in nearby 

municipal-supply wells is minimal or absent, the 

direction of flow through the fracture at about 

524 ft above sea level is south toward two 

industrial-supply wells. Flow through the fracture 

is toward the municipal-supply wells when they 

are being pumped. Flow in the upper part of the 

Galena-Platteville aquifer does not appear to be 

affected by pumping in nearby water-supply wells.

Chlorinated ethenes were the volatile 

organic compounds detected most often and at 

the highest concentration in the Galena-Platteville 

aquifer beneath northeastern Belvidere. Volatile 

organic compounds are migrating primarily to 

the southeast toward the Kishwaukee River, with 

components of movement to the north, east, and 

west. Volatile organic compound and monitored 

natural attenuation parameter data indicate reductive dechlorination of some chlorinated ethene 

compounds is occurring under either nitrate or 

iron-reducing conditions in the unconsolidated 

deposits and possibly the upper part of the GalenaPlatteville aquifer near the center of the plume. 

Oxidizing conditions appear to be present at least 

in the upper part of the aquifer beneath most of 

the study area, and the occurrence of reductive 

dechlorination in the Galena-Platteville aquifer 

beneath most of the area of investigation is not 

clearly indicated.

INTRODUCTION

Volatile organic compounds (VOC’s) have been 

detected in water from the Galena-Platteville aquifer 

beneath the Parson’s Casket Hardware Superfund site 

(hereafter referred to as the PCHSS) in the northeastern 

part of the city of Belvidere, in Boone County, Ill. 

(fig. 1). The extent of contamination in this fracturedbedrock aquifer has not been defined nor has the 

potential for contaminants to migrate to groundwater receptors, especially nearby industrial- and 

municipal-supply wells and the Kishwaukee River. 

The U.S. Geological Survey (USGS), in cooperation 

with the Illinois Environmental Protection Agency 

(IEPA), investigated the geology, hydrology, and 

distribution of contaminants in the Galena-Platteville 

aquifer in the vicinity of the PCHSS. The area of 

concern for this investigation (hereafter referred to 

as the study area) extends to the Kishwaukee River 
2 Geology, Hydrology, and Ground-Water Quality of the Galena-Platteville Aquifer in the Vicinity of the Parson’s Casket Hardware Superfund Site, 

Belvidere, Illinois

Figure 1. Location of study area, boreholes, and water-supply wells in the vicinity of the Parson’s Casket Hardware Superfund 

site, Belvidere, Ill.
Introduction 3

to the south, approximately Gardner Street to the west, 

Bonus Avenue to the east, and approximately 100 ft 

north of the northern part of the PCHSS (fig. 1).

This investigation was designed to determine 

the nature and extent of contaminants in the GalenaPlatteville aquifer in the vicinity of the PCHSS, to 

identify the pathways of contaminant migration 

through the aquifer and the potential receptors of 

the contaminated ground water, and to evaluate the 

potential for natural attenuation processes to eliminate 

contaminants from the aquifer or reduce their concentrations below regulatory levels. The information 

collected for this investigation will be used to assess 

remediation strategies at the PCHSS. In addition, 

the information obtained from this investigation 

can be used to determine the processes that affect 

the development of secondary-permeability features 

and the lateral continuity of these features in northeastern Belvidere.

The investigation comprised four principal 

efforts: 1) geophysical logging, 2) collecting waterlevel data, 3) aquifer testing, and 4) water-quality 

sampling. Natural-gamma, acoustic-televiewer, shortnormal and fluid-column resistivity, temperature, 

caliper, and heat-pulse flowmeter logs were run in 

boreholes G124GP, G130GP, G133GP, G134GP, and 

G136GP, which were drilled for this investigation 

(fig. 1, table 1) to determine stratigraphy; location, 

orientation, and extent of hydraulically active vugs 

and fractures; and directions of ground-water flow in 

the Galena-Platteville aquifer beneath the study area. 

After completion of borehole testing, wells G124GPS 

and G124GPD were installed in borehole G124GP, 

well G130GP was installed in borehole G130GP, 

well G133GP was installed in borehole G133GP, 

wells G134GPS and G134GPD were installed in 

borehole G134GP, and wells G136GPS and G136GPD 

were installed in borehole G136GP (table 1). Static 

water-level measurements were collected in the boreholes from 19 intervals isolated with a packer assembly 

to identify the vertical direction of ground-water flow 

in the Galena-Platteville aquifer in the study area. In 

six completed monitoring wells, static water levels 

were measured at 15-minute intervals for a total 

period of about 1 month to help identify the presence 

of pumping effects from nearby water-supply wells 

on water levels and flow directions in the GalenaPlatteville aquifer. Specific-capacity tests were 

done in each borehole and slug tests were done in 

16 test intervals isolated with a packer assembly to 

quantify the hydraulic properties of the GalenaPlatteville aquifer. Water samples were collected 

from 18 intervals isolated with a packer assembly 

to define ground-water quality and the spatial distribution of contaminants in the Galena-Platteville aquifer 

and to help evaluate the potential for natural attenuation of contamination in the aquifer beneath the study 

area.

Purpose and Scope

This report describes the results of an investigation that used packer assemblies and geophysical 

logging to characterize the geology, hydrology, and 

water quality of the Galena-Platteville aquifer beneath 

the study area in northeastern Belvidere, Ill. This work 

was done primarily in the summer and fall of 1999. The 

results of geophysical logging using conventional and 

heat-pulse flowmeter logs in six boreholes in the study 

area are presented in this report. In addition, the report 

presents the results of water-level monitoring in six 

completed monitoring wells, as well as water-level 

monitoring, aquifer testing, and water-quality sampling in as many as 19 test intervals isolated with a 

packer assembly in the six boreholes. This report 

identifies the pathways of ground-water flow and 

contaminant movement through the Galena-Platteville 

aquifer beneath the study area, the extent of the hydraulically active features transmitting the flow, and the 

potential for contaminant migration to ground-water 

receptors.

Acknowledgments

The author extends thanks to Jason Thorpe 

of the IEPA for his assistance with data collection. 

John Grabs and Ray Mastrolonardo of Tetra Tech 

EM Inc., Eric Runkel of the IEPA, James Grimes of the 

city of Belvidere, Gary Yunto of the Pillsbury Corporation, and Environmental Contractors of Illinois also are 

thanked for their assistance with the study. In addition, 

Mr. Allen Silver, Mr. and Ms. Wheeler, CamcarTextron Corporation, Belvidere Construction 

Company, and the city of Belvidere are thanked 

for allowing access to their property.
4 Geology, Hydrology, and Ground-Water Quality of the Galena-Platteville Aquifer in the Vicinity of the Parson’s Casket Hardware Superfund Site, 

Belvidere, Illinois

GEOLOGY

The geologic units of primary concern to this 

investigation are the Ordovician-aged dolomite deposits of the Platteville and Galena Groups (figs. 2-7). 

Quaternary glacial and glaciofluvial deposits unconformably overlie these deposits. Argillaceous dolomite 

and sandstone deposits of the Glenwood Formation and 

the St. Peter Sandstone underlie the Platteville and 

Galena dolomites. The stratigraphy of the St. Peter 

Sandstone, Glenwood Formation, and Platteville and 

Galena Groups in the study area was determined by 

personnel from the Illinois State Geological Survey 

(ISGS) on the basis of cores collected at the PCHSS 

(Mills and others, 1998). The stratigraphic nomenclature used in this report is that of the ISGS (Willman and 

others, 1975, p. 61-81) and does not necessarily follow 

the usage of the USGS.

The St. Peter Sandstone is a coarse-to-medium 

grained quartz arenite, characterized by a high percentage of well-rounded quartz grains (Mills and others, 

1998). The altitude of the top of the St. Peter Sandstone 

beneath the study area is about 420 ft above sea level. 

The Glenwood Formation overlies the St. Peter 

Sandstone and is composed of interbedded sandstone 

and argillaceous dolomite beneath the study area (Mills 

and others, 1998). Sandstone layers predominate at the 

base of the formation, and argillaceous dolomite layers 

predominate at the top of the formation. The altitude of 

the top of the Glenwood Formation beneath the study 

area is about 450 ft above sea level.

The Platteville and Galena Groups are the 

uppermost bedrock deposits beneath the study area 

and consist of fractured, vesicular to vuggy, partly 

cherty, partly argillaceous dolomite with numerous 

shale partings. The groups are lithologically similar 

and are subdivided into formations primarily on the 

basis of subtle variations in clay and silt content 

(Willman and Kolata, 1978). Because natural-gamma 

logs measure variations in the amount of naturalgamma radiation emitted by the rock surrounding 

the borehole, which typically is a function of the 

clay content of the rock, comparing stratigraphic 

Table 1. Borehole and well information, altitude of top of bedrock, and transmissivity data in the 

vicinity of the Parson’s Casket Hardware Superfund site, Belvidere, Ill.

[na, not available; -, altitude below sea level]

Borehole

or well

name

Latitude/longitude

Land-surface

altitude

(feet above

sea level)

Depth of

open

interval

(feet below

land surface)

Altitude

of open

interval

(feet above

sea level)

Bedrocksurface

altitude

(feet above

sea level)

Transmissivity

(feet squared

per day)

G124GP 42°16′11′′/88°50′13′′ 782 35-267 515-747 752 na

G130GP 42°16′12′′/88°49′57′′ 788 41-230 558-747 751 5,400

G133GP 42°15′54′′/88°50′09′′ 778 45-268 510-733 738 430

G134GP 42°15′59′′/88°50′03′′ 784 55-267 516-728 738 270

G136GP 42°16′01′′/88°50′18′′ 782 28-283 499-754 759 1,100

BMW4 42°15′47′′/88°50′36′′ 777 152-1,800 -1,023-625 732 na

BMW6 42°16′15′′/88°50′28′′ 782 110-868 -86-672 757 na

00295 42°15′43′′/88°49′44′′ 770 63-627 133-697 697 na

00296 42°15′42′′/88°49′52′′ 778 55-550 230-725 725 27,000

Well name Latitude/longitude

Altitude, top of

inner casing

(feet above

sea level)

Depth of

screened

interval

(feet below

land surface)

Altitude of

screened interval

(feet above

sea level)

G124GPS 42°16′11′′/88°50′13′′ 784.56 42.5-47.5 734.5-739.5

G124GPD 42°16′11′′/88°50′13′′ 784.58 258.5-263.5 518.5-523.5

G130GP 42°16′12′′/88°49′57′′ 786.36 220-225 563-568

G133GP 42°15′54′′/88°50′09′′ 777.53 249.5-254.5 523.5-528.5

G134GPS 42°15′59′′/88°50′03′′ 784.08 57.5-62.5 721.5-726.5

G134GPD 42°15′59′′/88°50′03′′ 783.93 255-260 524-529

G136GPS 42°16′01′′/88°50′18′′ 781.73 32.5-37.5 744.5-749.5

G136GPD 42°16′01′′/88°50′18′′ 781.61 255.5-260.5 521.5-526.5
Geology 5

Figure 2. Generalized geologic column showing stratigraphy and hydrogeologic units in the vicinity of the Parson’s 

Casket Hardware Superfund site, Belvidere, Illinois.

descriptions and natural-gamma logs by previous 

investigators (Mills and others, 1998) has enabled the 

natural-gamma signal of the formations that compose 

the Platteville and Galena Groups to be identified. 

Natural-gamma signals from logs with stratigraphic 

descriptions obtained during previous investigations 

were compared with the natural-gamma logs obtained 

during the current investigation to correlate the 

stratigraphy of the Galena-Platteville deposits 

throughout the study area.

Although not penetrated by any of the boreholes 

drilled for this investigation, the Pecatonica Formation 

is the basal deposit of the Platteville Group and consists 

of a gray-to-brown, mottled, vuggy, fine-to-medium 

crystalline dolomite with some shale partings. The 

Pecatonica Formation overlies the Glenwood Formation and is present from about 451-478 ft above sea 

level beneath the study area (Mills and others, 1998).

The Mifflin Formation is composed of interbedded light gray and light brown, very fine to coarsely 

crystalline dolomite with interbedded gray, black, red, 

and brown shale. The altitude of the Mifflin Formation 

is about 478-501 ft beneath the study area. The upper 

part of the Mifflin Formation is penetrated by borehole 

G136GP.

The Grand Detour Formation overlies the 

Mifflin Formation and is composed of gray, very fine 

to medium crystalline dolomite with mottles and shale 

partings in some members. The Grand Detour Formation is present at an altitude of about 501-547 ft above 

sea level beneath the study area. Parts of the Grand 

Detour Formation can be identified by the peaks in 

the natural-gamma logs at about 524 and 534 ft (figs. 3, 

5-7).

The Nachusa Formation overlies the Grand 

Detour Formation and is composed of mottled, brown 

and gray, fine to medium crystalline dolomite with 

some chert. The Nachusa Formation is present at an 

altitude of about 547-556 ft above sea level beneath the 

study area and corresponds to a low counts-per-second 

interval on the natural-gamma log between the upper 

part of the Grand Detour Formation and the lower part 

of the Quimbys Mill Formation (figs. 3, 5-7).

The Quimbys Mill Formation, the uppermost 

formation of the Platteville Group, is composed of 

gray, very fine to finely crystalline dolomite with 

thin shale partings and some chert. The Quimbys Mill 

Formation is present at an altitude of about 556-568 ft 

above sea level beneath the study area (figs. 3-7).
Geology 7

Figure 3. Natural-gamma, short-normal resistivity, fluid temperature, fluid-column resistivity, acoustic-televiewer, and flowmeter logs; stratigraphy; horizontal hydraulic conductivities; and total concentration of volatile organic compounds in the test intervals isolated with a 

packer assembly for borehole G124GP in the vicinity of the Parson’s Casket Hardware Superfund site, Belvidere, Ill. (See figure 1 for location of borehole.)
8 Geology, Hydrology, and Ground-Water Quality of the Galena-Platteville Aquifer in the Vicinity of the Parson’s Casket Hardware Superfund Site, 

Belvidere, Illinois

Figure 4. Natural-gamma, short-normal resistivity, fluid temperature, fluid-column resistivity, acoustic-televiewer, and flowmeter logs; stratigraphy; horizontal hydraulic conductivities; and total concentration of volatile organic compounds in the test intervals isolated with a 

packer assembly for borehole G130GP in the vicinity of the Parson’s Casket Hardware Superfund site, Belvidere, Ill. (See figure 1 for location of borehole.)
Geology 9

Figure 5. Natural-gamma, short-normal resistivity, fluid temperature, fluid-column resistivity, acoustic-televiewer, and flowmeter logs; stratigraphy; horizontal hydraulic conductivities; and total concentration of volatile organic compounds in the test intervals isolated with a 

packer assembly for borehole G133GP in the vicinity of the Parson’s Casket Hardware Superfund site, Belvidere, Ill. (See figure 1 for location of borehole.)
10 Geology, Hydrology, and Ground-Water Quality of the Galena-Platteville Aquifer in the Vicinity of the Parson’s Casket Hardware Superfund Site, 

Belvidere, Illinois

Figure 6. Natural-gamma, short-normal resistivity, fluid temperature, fluid-column resistivity, acoustic-televiewer, and flowmeter logs; stratigraphy; horizontal hydraulic conductivities; and total concentration of volatile organic compounds in the test intervals isolated with a 

packer assembly for borehole G134GP in the vicinity of the Parson’s Casket Hardware Superfund site, Belvidere, Ill. (See figure 1 for location of borehole.)
Geology 11

Figure 7. Natural-gamma, short-normal resistivity, fluid temperature, fluid-column resistivity, acoustic-televiewer, and flowmeter logs; stratigraphy; horizontal hydraulic conductivities; and total concentration of volatile organic compounds in the test intervals isolated with a 

packer assembly for borehole G136GP in the vicinity of the Parson’s Casket Hardware Superfund site, Belvidere, Ill. (See figure 1 for location of borehole.)
12 Geology, Hydrology, and Ground-Water Quality of the Galena-Platteville Aquifer in the Vicinity of the Parson’s Casket Hardware Superfund Site, 

Belvidere, Illinois

The basal deposit of the Galena Group in the 

study area is the Dunleith Formation (fig. 2). The 

Dunleith Formation is composed of cherty, gray-tobrown, medium to coarsely crystalline dolomite with 

some shale partings and mottling. The altitude of the 

Dunleith Formation is about 568-633 ft above sea level 

beneath the study area. The basal part of the Dunleith 

Formation can be identified on the natural-gamma logs 

by the elevated counts-per-second interval between 

about 572 and 597 ft (figs. 3-7). The Guttenburg 

Formation, which separates the Dunleith and Quimbys 

Mill Formations in much of Illinois, has been eroded 

away in the Belvidere area, and the Dunleith Formation 

unconformably overlies the Quimbys Mill Formation.

The Wise Lake Formation of the Galena Group 

overlies the Dunleith Formation and consists of tan 

and gray, vuggy, medium to thickly bedded, coarsely 

crystalline dolomite with some mottles. The Wise Lake 

Formation typically contains only small amounts of 

clay minerals (Willman and others, 1975). The contact 

between the Wise Lake Formation and the overlying 

Dubuque Formation (a brown to gray, medium to 

coarsely crystalline dolomite with shale partings) could 

not be identified in the cores collected during previous 

investigations at the PCHSS (Mills and others, 1998), 

and the two formations were not differentiated. The 

shaley layer at 662 ft above sea level is present throughout the study area.

Acoustic-televiewer logs measure the intensity 

of an acoustic signal reflected off the borehole wall 

(Keys, 1988). The log measures the amount of reflection of an oriented signal from the borehole wall over 

all 360 degrees at a given depth, providing an analog 

image of the borehole wall. Fractures, vugs, and other 

discontinuities in the borehole walls (such as a washout 

area where a shale parting has been eroded away) 

scatter the reflected signal and show up as dark areas 

on the logs (figs. 3-7). Because the signal is oriented, 

the depth, apparent thickness, and orientation of any 

fractures, vugs, and solution openings that intersect the 

borehole can be determined.

Vuggy intervals were detected at about 

684-704 and 724-734 ft at borehole G124GP, 

between 693-708 ft at borehole G130GP, between 

673-698 ft at borehole G133GP, above about 638 ft at 

borehole G134GP, and above about 662 ft at borehole 

G136GP (figs. 3-7). Televiewer logs run during previous investigations at the PCHSS indicate numerous 

vuggy intervals, including intervals at about 600-640 

and 682-702 ft at borehole T7 (Kay and others, 2000) 

and 570-604, 624-654, 672-706 ft above sea level at 

well G127GP (Mills, 1993a). A televiewer log run 

during a previous investigation in borehole G128GP, 

located about 0.50 mi from the PCHSS and about 50 ft 

from Belvidere Municipal Well 6 (BMW6) (fig. 1), 

indicates the presence of vugs throughout the borehole, 

with some apparent concentration at about 500-510, 

525-532, 540-560, 570-600, and 660-720 ft above sea 

level (Mills and others, 1998).

Acoustic-televiewer logs show numerous dark 

areas associated with subhorizontal fractures and 

perhaps washed out shale partings throughout the 

Galena-Platteville deposits (figs. 3-7, table 2). Almost 

all dark areas are associated with an increase in borehole diameter observed on the caliper logs (data not 

shown), which may be indicative of fractures. For the 

purposes of this discussion, all such features are 

assumed to be fractures. The subhorizontal fracture 

associated with the shaley bed at about 662 ft and the 

subhorizontal fracture near the bottom of the Dunleith 

and top of the Quimbys Mill Formations at about 564 ft 

were detected in each borehole drilled for this investigation, in addition to being detected at boreholes 

G127GP and G128GP. Subhorizontal fractures corresponding to argillaceous parts of the Grand Detour 

Formation were detected at about 524 ft above sea 

level in boreholes G124GP, G133GP, G134GP, and 

G136GP; and in boreholes G127GP, and G128GP 

(Mills and others 1998). Boreholes T7 and G130GP 

did not penetrate to 524 ft. Subhorizontal fractures 

were detected by televiewer logging at about 536, 579, 

596, 648, 683, 702, 725, 732, and 738-745 ft above sea 

level in four or more boreholes in and near the study 

area (table 2). A subhorizontal fracture was detected 

in the middle of the Mifflin Formation at about 482 ft 

during previous investigations at the PCHSS (Mills and 

others, 1998).

Development of subhorizontal fractures in the 

Galena-Platteville deposits appears to be affected by 

a variety of processes. Subhorizontal fractures in the 

upper 10-20 ft of the bedrock are likely to be present 

because of weathering and erosion of the bedrock 

surface, particularly during the Quaternary system. 

The presence of some deeper, more areally extensive 

fractures appear to be affected by the stratigraphy and 

lithology of the Galena-Platteville deposits. The apparent fracture associated with the shaley bed at an altitude 

of 662 ft, for example, is located throughout the study 

area and may be due to a washout of the shale. The 

apparent fracture at about 564 ft, near the contact 
Hydrology 13

between the Quimbys Mill and Dunleith Formations, 

may be related to an unconformity during the Ordovician system. The fracture above the shale bed in the 

Grand Detour Formation, which also was observed at 

the Byron Salvage Yard Superfund site 30 mi west of 

the study area (Kay and others, 1997), may be related 

to enhanced dissolution associated with preferential 

ground-water flow above the shale layer.

Inclined fractures were detected at borehole 

G133GP at about 550 and 715 ft above sea level 

(fig. 5). The shallow inclined fracture had a measured 

dip of 86 degrees and a strike of 19 degrees west of 

north. The trend of this fracture is toward the western 

boundary of the PCHSS. The deeper inclined fracture 

at borehole G133GP has a dip of about 88 degrees and 

a strike of 79 degrees west of north. Inclined fractures 

at boreholes T1 and T6 on the PCHSS had a strike of 

about 30 degrees east of north (Kay and others, 2000). 

These trends are consistent with a vertical-fracture 

orientation of 30 degrees east of north and a second set 

oriented about 75 degrees west of north measured at a 

quarry about 5 mi from the study area in southeastern 

Boone County (Foote, 1982).

Short-normal resistivity logs were consistent 

between boreholes and tended to be inversely related to 

the natural-gamma logs (figs. 3-7). Resistivity values 

lower than the typical values for each log were measured at the shaley bed at about 662 ft and argillaceous 

dolomite units at about 522, 536, and 579 ft above sea 

level. Low normal-resistivity values are typical of 

porous and poorly consolidated deposits (Keys, 1988).

The top of the bedrock surface in the study area 

is highest (about 759 ft above sea level) west of the 

PCHSS and decreases toward the south and east to 

an estimated altitude of less than 650 ft beneath the 

Kishwaukee River (Berg and others, 1984). The highly 

weathered interval is restricted primarily to the upper 

10-20 ft of the dolomite deposits.

Quaternary deposits unconformably overlie the 

bedrock throughout the study area. Quaternary deposits typically are less than 50 ft thick in the northern part 

of the study area, but thicken southward to an estimated 

150 ft beneath the Kishwaukee River (Berg and others, 

1984). Glaciofluvial sand-and-gravel deposits directly 

overlie the bedrock throughout most of the study area 

(Science Applications International Corporation, 1992, 

figs. 3-12 to 3-17). The sand-and-gravel deposits are 

overlain by silty clay with interspersed sand and gravel 

(Science Applications International Corporation, 1992, 

figs. 3-12 to 3-17).

HYDROLOGY

The hydrologic units of concern in the study 

area are the shallow unconsolidated aquifer, the 

unconsolidated semiconfining unit, the deep unconsolidated aquifer, the Galena-Platteville aquifer, the Glenwood semiconfining unit, and the St. Peter Sandstone 

aquifer (fig. 2). The shallow unconsolidated aquifer is 

composed of saturated sand-and-gravel deposits 

present in the southern part of the PCHSS (Science 

Applications International Corporation, 1992). This 

aquifer is not present in most of the study area. The 

unconsolidated semiconfining unit is composed of 

unconsolidated silt and clay deposits that overlie the 

deep unconsolidated aquifer. The deep unconsolidated 

aquifer is composed of saturated sand-and-gravel 

deposits that are in good hydraulic connection with the 

upper part of the underlying Galena-Platteville aquifer 

(Mills, 1993a). The Glenwood semiconfining unit is 

composed of argillaceous dolomite deposits in the 

Table 2. Altitude of subhorizontal fractures identified from televiewer logs in selected boreholes in the vicinity of the Parson’s Casket 

Hardware Superfund site, Belvidere, Ill.

[-, fracture not identified at this altitude; np, Galena-Platteville deposits not present at this altitude; bwl, below water level in borehole, presence of fracture 

cannot be verified by televiewer log]

Borehole

name Altitude of subhorizontal fracture, in feet above sea level

G124GP 744 - - - 723 703 684 - - 662 - - - - - - - 608 596 - 564 563 - 538 524

G130GP 743 738 736 732 727 703 - - - 664 - - - - - - - - - 581 565 - np np np

G133GP np np np 734 726 704 684 - - 665 - 653 - - - - - - 598 578 569 558 - 536 524

G134GP np np np np 723 - 683 680 675 663 - - - 639 - - 614 - 600 579 565 - - 534 524

G136GP np bwl bwl 732 - 702 - - - 662 660 - 648 - 630 624 - - 596 576 566 - - 534 522

G127GP - 738 - - - - 682 - - 660 - - - - - - - - - - 566 - 546 536 524

G128GP 744 742 - - - 707 682 - - 660 - - 645 643 - - - - - 579 562 - - 534 521

T7 745 - - 732 - 700 - - - 660 - - 649 - - - - - 598 578 np np np np np
14 Geology, Hydrology, and Ground-Water Quality of the Galena-Platteville Aquifer in the Vicinity of the Parson’s Casket Hardware Superfund Site, 

Belvidere, Illinois

upper part of the Glenwood Formation. The St. Peter 

Sandstone aquifer underlies the Glenwood semiconfining unit and is composed of the sandstones of the 

Glenwood and St. Peter Sandstone Formations. This 

investigation focused on the hydrology of the GalenaPlatteville aquifer. The hydrology of the other units is 

not discussed in this report, except as it pertains to the 

hydrology and water quality of the Galena-Platteville 

aquifer.

Hydraulically Active Features

Temperature logs measure the temperature of 

the fluid column in the borehole. Water temperature 

in the Galena-Platteville aquifer typically was between 

52 and 56°F and decreased with depth (figs. 3-7). 

Fluid-column-resistivity logs measure the capability 

of the water in the borehole to conduct electrical 

current and can show an inverse relation to the concentration of dissolved solids in the fluid column (Keys, 

1988). Fluid-column-resistivity values for the GalenaPlatteville aquifer ranged between 15 and 30 ohmmeters and increased overall with depth (figs. 3-7). 

Because variations in water quality with depth in a 

borehole can be caused by inflow (flow from the aquifer into the borehole) or outflow (flow from the borehole out to the aquifer), changes of temperature and 

fluid resistivity with depth in the borehole can indicate 

intervals of increased aquifer permeability. Both 

temperature and fluid-column-resistivity logs show 

abrupt changes at about 563 and 727 ft above sea level 

in borehole G124GP and possibly at about 743 ft in 

borehole G130GP. Both logs show a change in slope 

at about 660 ft in borehole G133GP and above about 

663-673 ft in borehole G134GP. These logs also show 

abrupt changes at about 524 and 567 ft and possibly a 

slight change at about 597, 662, and 707 ft in borehole 

G136GP.

Heat-pulse flowmeter logs measure the rate 

and direction of ground-water flow within a borehole 

induced by the variations in hydrostatic pressure within 

that part of the aquifer penetrated by the borehole. 

Commonly, depths where changes in the rate of flow 

occur are associated with features that have increased 

permeability. Inflow is identified by an increase in flow 

rate in the direction of flow. Outflow is identified by a 

decrease in the flow rate in the direction of flow.

Flow direction and aquifer permeability were 

characterized on the basis of data from flowmeter logs 

run under ambient-flow conditions (no pumping in the 

boreholes) in boreholes G124GP, G130GP, G133GP, 

G134GP, and G136GP and during pumping near the 

top of the water column in boreholes G124GP, 

G133GP, G134GP, and G136GP (Frederick Paillet, 

U.S. Geological Survey, written commun., 1999) 

(figs. 3-7). Flowmeter logging indicates groundwater flow was directed downward in the GalenaPlatteville aquifer at each borehole under ambientflow conditions.

Flowmeter logging under ambient-flow conditions in borehole G124GP indicated gradually increasing inflow associated with subhorizontal fractures and 

vugs from about 662 to 739 ft, inflow associated with a 

subhorizontal fracture at about 564 ft, and outflow 

through the subhorizontal fracture at about 524 ft 

(fig. 3). Flowmeter logging during pumping identified 

the same hydraulically active features, but highlighted 

the flow contributions from the subhorizontal fractures 

at 662 and 739 ft above sea level.

Flowmeter logging under ambient-flow conditions in borehole G130GP indicated inflow associated 

with the subhorizontal fracture at about 746 ft and 

outflow through the subhorizontal fracture at about 

564 ft (fig. 4). No other hydraulically active features 

were identified in this borehole.

Flowmeter logging under ambient-flow conditions in borehole G133GP indicated inflow associated 

with the subhorizontal fracture below the bottom of the 

casing at about 734 ft, gradually increasing inflow 

associated with vugs and subhorizontal and inclined 

fractures from about 665 to 734 ft and outflow through 

the subhorizontal fracture at about 524 ft (fig. 5). No 

flow was identified through the inclined fracture at 

about 550 ft. Flowmeter logging during pumping 

identified the same hydraulically active features.

Flowmeter logging under ambient-flow 

conditions in borehole G134GP indicated gradually 

increasing inflow associated with subhorizontal fractures and vugs from about 662 to 723 ft and outflow 

through the subhorizontal fracture at about 524 ft 

(fig. 6). Flowmeter logging during pumping identified 

the same hydraulically active features.

Water-level fluctuations in borehole G136GP 

prevented collection of acoustic-televiewer data from 

732 to 754 ft, so the features in this interval (vugs, 

fractures) could not be identified. However, flowmeter 

logging under ambient-flow conditions in borehole 

G136GP indicated inflow associated with unidentified 

features between about 740 ft and the bottom of the 

well casing at 754 ft. The large increase in flow over a 
Hydrology 15

short distance indicates these features probably are 

fractures. Gradually increasing inflow is associated 

with subhorizontal fractures and vugs from about 662 

to 740 ft above sea level. Outflow was through the subhorizontal fracture at about 524 ft (fig. 7). Flowmeter 

logging during pumping identified the same hydraulically active intervals but emphasized the presence of 

the flow contributions from the interval between about 

662 and 740 ft.

Borehole flow values measured during 

pumping in boreholes G124GP, G133GP, G134GP, 

and G136GP were similar to values measured under 

ambient conditions below about 662 ft. Differences 

between the amount of flow under ambient and 

pumping conditions generally increased with increasing altitude above 662 ft, indicating that the amount of 

drawdown induced by pumping was sufficient to divert 

a substantial amount of the downflow above 662 ft but 

had little affect below 662 ft. This pattern indicates the 

hydraulic head within the Galena-Platteville aquifer 

above 662 ft is substantially greater than the hydraulic 

head below 662 ft and that vertical hydraulic gradients 

in the aquifer above 662 ft are lower than vertical 

hydraulic gradients in the aquifer below 662 ft.

The depths of the hydraulically active features 

identified by the flowmeter logs generally are consistent with the depths of the hydraulically active features 

indicated by the temperature and fluid-resistivity logs. 

Results of the flowmeter logging obtained during the 

current investigation are partially consistent with the 

results of flowmeter logging done as part of previous 

investigations in boreholes in and near the study area 

(Mills, 1993b; Mills and others, 1998; Kay and others, 

2000). Flow was identified from shallow fractures 

near the top of the dolomite, vugs in the upper part 

of the bedrock, the shaley interval at 662 ft, and the 

subhorizontal fracture at about 524 ft during previous 

investigations at the PCHSS and at borehole G128GP. 

However, flow through the vugs in the upper part of the 

bedrock, where present, tended to be restricted to about 

682-692 ft in boreholes logged for previous investigations, and the amount of flow through the fracture at 

about 662 ft was higher for previous investigations than 

detected during the current investigation. In addition, 

flow measured through a vuggy interval between 640 

and 590 ft at boreholes T1-T7 during a previous investigation (Kay and others, 2000) was not detected in the 

boreholes drilled for this investigation. The results of 

the flowmeter logging indicate hydraulically active 

features consistently are present near the bedrock 

surface and at about 524 ft in the study area, but the 

presence and extent of hydraulic activity in the vuggy 

intervals and the other fractures is variable in the study 

area.

Water Levels

In September 1999, vertical variations in water 

levels within the Galena-Platteville aquifer were measured in discrete test intervals isolated with a packer 

assembly (table 3). The packer assembly consists of 

two 4-ft-long inflatable nitrile packers separated by 

10 ft of stainless-steel screen (fig. 8). The packer 

assembly was constructed so that water levels could be 

measured above, within, and below the test intervals 

after the packers were inflated and the water levels had 

equilibrated. Water levels above, within, and below the 

test intervals were not equal, which indicates that the 

packers were effectively isolating the test intervals 

from the rest of the borehole.

Test intervals isolated with the packer assembly 

consisted of representative intervals of boreholes 

G124GP, G130GP, G133GP, G134GP, and G136GP 

(table 3). The water-level altitude decreased consistently above, within, and below the packed intervals 

in each borehole, indicating the potential for downward 

flow within the Galena-Platteville aquifer throughout 

the study area. This interpretation is consistent with the 

results of the flowmeter logging. This interpretation 

also is consistent with the results of previous investigations in and near the study area, although transient 

upward flow occasionally was indicated during previous investigations (Mills and others, 1998; Kay and 

others, 2000).

Water levels in the test intervals open to the 

fracture at about 524 ft in boreholes G124GP, G133GP, 

G134GP, and G136GP typically were substantially 

lower than the water levels in the overlying intervals. 

Vertical variation of water levels in the test intervals 

at borehole G130GP, which does not penetrate the 

fracture at 524 ft, are substantially less than the vertical 

variation of water levels in the remaining boreholes. 

The low water levels near the bottom of the boreholes 

indicate pumping effects from Belvidere Municipal 

Well 4 (BMW4) and BMW6, and possibly other watersupply wells, are being transmitted through the fracture 

at 524 ft and also may indicate low vertical hydraulic 

interconnection within the Galena-Platteville aquifer.

Water levels in the test intervals open at or near 

the shaley layer at about 662 ft in boreholes G124GP, 
16 Geology, Hydrology, and Ground-Water Quality of the Galena-Platteville Aquifer in the Vicinity of the Parson’s Casket Hardware Superfund Site, 

Belvidere, Illinois

G133GP, and G136GP were within 2.5 ft of the water 

levels above the test interval but were more than 14 ft 

higher than the water levels below the test interval 

(table 3). The small difference in water levels above 

662 ft and the large difference in water levels below 

662 ft may indicate substantial pumping effects are not 

transmitted up to this altitude in these wells and vertical 

hydraulic interconnection (perhaps because of an 

increased density of vertical fractures or an extensive 

network of interconnected vugs) within the GalenaPlatteville aquifer is greater above the shaley layer than 

below the shaley layer.

Previous investigations in the vicinity of the 

PCHSS have established that water levels in the lower 

parts of the Galena-Platteville aquifer can fluctuate by 

more than 20 ft in response to individual pumping 

cycles at BMW4 and BMW6 (Mills and others, 1998; 

Kay and others, 2000) and perhaps other water-supply 

wells in Belvidere. Water levels were monitored in 

wells G133GP, G134GPS, G134GPD, G136GPS, and 

G136GPD from February 4-28, 2000, and in wells 

G124GPS and G124GPD from February 14-28, 2000, 

to establish the effects of pumping from water-supply 

wells on water levels and flow directions in the 

Galena-Platteville aquifer (figs. 9-12). Wells 

G124GPD, G133GP, G134GPD, and G136GPD are 

open to the subhorizontal fracture at about 524 ft above 

sea level. Wells G124GPS, G134GPS, and G136GPS 

are open near the top of the Galena-Platteville aquifer. 

Water levels in each well were measured simultaneously with calibrated pressure transducers and 

recorded with a datalogger every 15 minutes. Periodic 

water-level measurements using electric tapes indicated the transducers were giving accurate waterlevel readings.

Pumping schedules during the monitoring period 

are not representative of typical conditions. During 

periods of normal operations, BMW4 is pumped 

frequently for periods of tens of minutes, whereas 

BMW6 is pumped less frequently but often for more 

than 100 minutes. BMW4 was not in operation during 

the monitoring period, whereas BMW6 was pumped 

frequently each day for periods of tens of minutes. 

Industrial-supply wells 00295 and 00296 south of the 

Table 3. Water levels measured during testing with a packer assembly under approximately hydrostatic 

conditions in the vicinity of the Parson’s Casket Hardware Superfund site, Belvidere, Ill., September 1999

[na, not applicable; <, less than; nt, measurement not taken]

Borehole

name

Date of

measurement

Altitude of

test interval

(feet above

sea level)

Water-level altitude (feet above sea level)

Open borehole

before packer

inflation

Above test

interval

In test

interval

Below

test interval

G124GP September 10, 1999 737-747 742.75 na 757.03 <754

G124GP September 10, 1999 716-747 nt na 748.68 745.87

G124GP September 10, 1999 658-668 747.25 760.38 758.40 743.87

G124GP September 10, 1999 556-566 nt 758.11 752.51 731.49

G124GP September 10, 1999 518-540 nt 756.23 726.45 na

G124GP September 11, 1999 518-540 nt 758.95 731.55 na

G130GP September 8, 1999 742-747 nt na 763.48 761.72

G130GP September 10, 1999 626-636 nt 763.41 756.79 751.15

G130GP September 10, 1999 558-576 751.46 nt 750.07 na

G133GP September 14, 1999 726-733 732.57 na 756.35 747.41

G133GP September 14, 1999 667-677 735.80 752.26 751.05 732.16

G133GP September 15, 1999 667-677 736.22 757.11 755.93 728.62

G133GP September 15, 1999 522-532 nt 751.58 730.18 nt

G134GP September 16, 1999 718-728 nt na 753.12 748.35

G134GP September 16, 1999 692-702 nt 753.28 753.02 748.30

G134GP September 17, 1999 628-638 nt 753.89 743.51 732.81

G134GP September 17, 1999 516-537 748.07 752.24 728.41 na

G136GP September 20, 1999 742-754 749.30 na 763.61 <759

G136GP September 20, 1999 667-677 nt 763.83 761.5 732.81

G136GP September 21, 1999 637-647 nt 763.57 741.33 733.17

G136GP September 21, 1999 520-530 736.57 759.55 729.18 729.12
Hydrology 17

Figure 8. Packer assembly and ground-water sampling pump in a borehole.
18 Geology, Hydrology, and Ground-Water Quality of the Galena-Platteville Aquifer in the Vicinity of the Parson’s Casket Hardware Superfund Site, 

Belvidere, Illinois

Figure 9. Water-level altitude in wells G124GPD, G133GP, G134GPD, and G136GPD in the vicinity of the Parson’s 

Casket Hardware Superfund site, Belvidere, Ill., February 4-28, 2000.
Hydrology 19 Figure 10. Pumping totals for wells 00295 and 00296 combined and well BMW6 in the vicinity of the Parson’s Casket Hardware Superfund site, Belvidere, Ill., February 4-28, 2000.
20 Geology, Hydrology, and Ground-Water Quality of the Galena-Platteville Aquifer in the Vicinity of the Parson’s Casket Hardware Superfund Site, 

Belvidere, Illinois

Figure 11. Water-level altitude in wells G124GPD, G133GP, G134GPD, and G136GPD in the vicinity of the Parson’s Casket Hardware Superfund site, Belvidere, Ill., February 6-19, 2000.
Hydrology 21

Figure 12. Water-level altitude in wells G124GPS, G134GPS, and G136GPS in the vicinity of the Parson’s Casket 

Hardware Superfund site, Belvidere, Ill., February 4-28, 2000.
22 Geology, Hydrology, and Ground-Water Quality of the Galena-Platteville Aquifer in the Vicinity of the Parson’s Casket Hardware Superfund Site, 

Belvidere, Illinois

river (fig. 1) are pumped continuously during the week 

but pump less water during the weekend. All watersupply wells are open from the upper part of the 

Galena-Platteville aquifer to a depth of 550 ft for 

well 00296, 627 ft for well 00295, 868 ft for well 

BMW6, and 1,800 ft for well BMW4 (table 1). 

Water is pumped from primarily the St. Peter 

Sandstone aquifer in wells 00296 and 00295. Water 

is pumped from primarily the St. Peter Sandstone and 

Ironton-Galesville aquifers in well BMW6. Water is 

pumped from primarily the St. Peter Sandstone, Ironton-Galesville, and Mt. Simon aquifers in well BMW4. 

The subhorizontal fracture at about 524 ft appears to be 

present at well BMW6 (Mills, 1993b; Mills and others, 

1998). Data are unavailable to determine if this fracture 

is present at well BMW4 or wells 00295 and 00296.

Water-level trends were similar in wells 

G124GPD, G133GP, G134GPD, and G136GPD 

(figs. 9, 11). Changes in water level in the wells 

in the 15 minutes between measurements were often 

greater than 1 ft. During the monitoring period, water 

levels in each well varied from about 719 to 741 ft 

above sea level. Water-level changes of this magnitude 

cannot be attributed to natural phenomena and likely 

are caused by the effects of pumping and the cessation 

of pumping in the water-supply wells.

Data from a USGS streamflow-gaging station 

(number 05438500) on the Kishwaukee River about 

2 mi downstream from the study area indicate the stage 

of the river ranged from about 739.5 to 742.5 ft above 

sea level during February 2000. The station is about 

0.5 mi downstream from a dam with about 5 ft of fall 

(Patrick Mills, U.S. Geological Survey, written 

commun., 2000). During February 2000, the stage of 

the Kishwaukee River at the study area upstream from 

the dam, therefore, must have been at least 5 ft higher 

than the stage measured at the streamflow-gaging 

station or about 744.5 to 747.5 ft above sea level. The 

stage of the Kishwaukee River was higher than the 

water-level altitude in the subhorizontal fracture at 

about 524 ft, indicating water in the deeper part of the 

Galena-Platteville aquifer near the PCHSS does not 

discharge to the Kishwaukee River.

Water levels were compared to daily pumping 

totals measured at wells 00295 and 00296 combined 

and well BMW6 (Gary Yunto, Pillsbury Corporation, 

written commun., 2000; James Grimes, city of 

Belvidere, written commun., 2000)(fig. 10). Although 

the wells were not pumped continuously for the entire 

monitoring period, pumping is assumed to be continuous. Comparison of water levels (fig. 9) and pumpage 

(fig. 10) indicate water levels typically decreased 

during periods of increased pumping in the watersupply wells and typically increased during periods 

of decreased pumping. No clear differentiation can 

be made between the effects of pumping in wells 

00295 and 00296, and BMW6.

Comparison of the water-level altitude in the 

wells open to the fracture at 524 ft above sea level 

indicates water-level fluctuations within a given 

time span tended to be largest at well G124GPD and 

more moderate in wells G133GP, G134GPD, and 

G136GPD (figs. 9, 11). Because of the variability in 

the water-level fluctuations, the relative water-level 

altitude in these wells changed frequently during the 

monitoring period and, therefore, flow directions 

through the fracture were variable.

During periods of high water levels, the waterlevel altitude in well G124GPD was often more than 

0.5 ft higher than in well G136GPD and the water-level 

altitude in well G136GPD was often about 0.5 ft higher 

than in wells G133GP and G134GPD, which tended to 

have similar water levels. These water-level trends 

indicate that during periods when pumping from the 

water-supply wells had a smaller effect on water levels, 

flow through the fracture in the Galena-Platteville 

aquifer at about 524 ft typically was from the PCHSS 

south toward the Kishwaukee River and wells 00295 

and 00296.

At 27,375 minutes into the monitoring period, 

when the lowest water levels were recorded, the waterlevel altitude in wells G124GPD, G133GP, G134GPD, 

and G136GPD were 720.13, 718.91, 719.70, and 

719.01 ft above sea level, respectively, indicating 

overall flow toward the Kishwaukee River at this time. 

During most of the periods of low water levels, however, the water-level altitude in well G136GPD was 

0.5-3 ft higher than in well G124GPD and less than 

1.5 ft higher than the water-level altitude in wells 

G134GPD and G133GP (fig. 11). These trends in water 

level indicate that during periods of pumping from well 

BMW6, a cone of depression is transmitted through 

the fracture at 524 ft. The magnitude of the cone of 

depression is large enough to overcome the natural 

gradient in this fracture at well G124GPD and perhaps 

well G136GPD, reversing the (presumed) natural 

direction of flow toward the south and inducing flow to 

the north toward BMW6. The extent of the area of 

reversal in the flow direction would likely be affected 

by the duration of pumping in well BMW6 and the 
Hydrology 23

pumping cycles in the other nearby water-supply wells 

but could potentially include all of the area beneath the 

PCHSS. It is possible that flow would be induced 

toward well BMW4 when well BMW4 is pumped.

The large water-level response in the wells 

open to the fracture at about 524 ft above sea level 

to the pumping cycles observed during the current 

and previous investigations indicates this fracture is 

hydraulically connected to wells BMW4 and BMW6 

and may be hydraulically connected to wells 00295 and 

00296 and other water-supply wells south of the river. 

During periods of comparatively high water levels, 

flow through the fracture appears to be toward the 

Kishwaukee River and wells 00296 and 00295. Comparatively high water levels in the fracture at about 

524 ft appear to result from smaller amounts of pumping in well BMW6, and perhaps other water-supply 

wells. During periods of comparatively low water 

levels associated with larger amounts of pumping 

in well BMW6, flow through the fracture at about 

524 ft appears to be toward well BMW6.

Water levels near the top of the GalenaPlatteville aquifer in wells G124GPS, G134GPS, 

and G136GPS varied by less than 1 ft during the 

monitoring period (fig. 12). Water levels in these wells 

showed a less than 0.30 ft of decline from the start of 

the monitoring until about 27,000 minutes, then rose by 

more than 0.2 ft, presumably in response to recharge 

from precipitation and snowmelt. Water levels in the 

wells open near the top of the aquifer showed no correlation with pumping in the water-supply wells and 

typically were 15 to 25 ft higher than water levels in 

the wells open to the fracture at about 524 ft. This 

result is consistent with the results of the water-level 

monitoring using the packer assembly and indicates 

the potential for downward flow within the aquifer and 

poor vertical hydraulic connection between the upper 

part of the aquifer and the fracture at 524 ft above sea 

level. Water levels in the shallow part of the GalenaPlatteville aquifer were greater than the estimated stage 

of the Kishwaukee River during the monitoring period, 

indicating the potential for water in the shallow part of 

the aquifer to discharge to the river.

Hydraulic Properties

The transmissivity of the Galena-Platteville 

aquifer at boreholes G130GP, G133GP, G134GP, 

and G136GP was calculated to range from 270 to 

5,400 ft2

/d on the basis of an analysis of the specificcapacity data obtained during purging of the boreholes 

(Walton, 1962) (table 1). These transmissivity values 

are based on numerous simplifying assumptions and 

should be considered rough estimates of the aquifer 

as a whole at the location of the boreholes. Details of 

the assumptions and methods used for analysis of the 

specific-capacity data are described in Kay and others 

(1994).

Transmissivity and horizontal hydraulic conductivity were calculated from data collected during slug 

testing in 16 discrete intervals isolated with a packer 

assembly at boreholes G124GP, G130GP, G133GP, 

G134GP, and G136GP (figs. 3-7; table 4). Packer 

assemblies (fig. 8) were used to isolate an interval 

of the borehole from the rest of the aquifer so that the 

hydraulic properties of the features (fractures and 

vugs) in the isolated intervals could be determined.

Slug-test data for the 742-747 ft test interval 

in borehole G130GP and the 522-532 ft test interval 

in borehole G133GP were analyzed on the basis 

of the oscillatory-response technique of van der 

Kamp (1976). Slug-test data from the remaining 

test intervals were analyzed on the basis of the 

technique of Bouwer and Rice (1976). Details of the 

methods used for collection and analysis of the slugtest data are described in Kay and others (2000). 

Horizontal-hydraulic-conductivity values are estimated from the transmissivity values by assuming 

an aquifer thickness equal to the thickness of the 

packed interval.

In the boreholes drilled for this investigation, 

calculated values for horizontal hydraulic conductivity 

of the test intervals within the upper 20 ft of the 

bedrock surface (742-747 ft in borehole G130GP, 

726-733 ft in borehole G133GP, and 718-728 ft in 

borehole G134GP) ranged from 0.61 to 360 ft/d. 

These values generally are consistent with the range 

of 0.054-170 ft/d for this interval calculated during 

previous investigations within the study area (Mills and 

others, 1998; Kay and others, 2000). The geometric 

mean horizontal hydraulic conductivity for the 12 slug 

tests done in the upper 20 ft of the bedrock for current 

and previous investigations in the study area is calculated to be 3.5 ft/d.

Horizontal-hydraulic-conductivity values 

calculated for the five test intervals open to the 

Galena-Platteville aquifer from more than 20 ft below 

the bedrock surface to the base of the shaley bed at 

about 662 ft ranged from 0.26 to 0.92 ft/d. These values 

are consistent with the range of 0.067-10 ft/d for this 
24 Geology, Hydrology, and Ground-Water Quality of the Galena-Platteville Aquifer in the Vicinity of the Parson’s Casket Hardware Superfund Site, 

Belvidere, Illinois

interval calculated during previous investigations 

(Mills, 1993b; Kay and others, 2000). The calculated 

geometric mean of the horizontal-hydraulic-conductivity values for the 28 slug tests done in this interval for 

current and previous investigations in the study area is 

0.36 ft/d.

Horizontal-hydraulic-conductivity values 

calculated from three slug tests done in the 525-662 ft 

interval of the boreholes drilled for this investigation, 

excluding the fracture at about 564 ft in boreholes 

G124GP and G130GP, ranged from 0.38 to 0.79 ft/d. 

These values are consistent with a range of 0.036-

0.80 ft/d calculated from this interval during previous 

investigations. The mean horizontal hydraulic conductivity for the 29 slug tests done in this interval within 

the study area was calculated to be 0.29 ft/d.

During this investigation, horizontal-hydraulicconductivity values calculated from the two slug tests 

done in the 564-ft fracture were 2.9 and 21 ft/d. These 

values are consistent with the values of 0.036 and 

15 ft/d calculated from this interval during previous 

investigations. The mean horizontal-hydraulicconductivity value calculated from the four slug 

tests open to the fracture at about 564 ft within the 

study area was calculated to be 2.4 ft/d.

Horizontal-hydraulic-conductivity values calculated from the three slug tests done in the fracture at 

about 524 ft during this investigation were 5.3, 5.7, and 

200 ft/d. These values generally are consistent with the 

values of 0.13 and 180 ft/d calculated from this interval 

during previous investigations (Mills and others, 

1998). The mean horizontal-hydraulic-conductivity 

value for the five slug tests done in this interval within 

the study area was calculated to be 11 ft/d.

Geophysical logging and aquifer testing done 

during the current investigation, combined with the 

results of previous investigations (Mills, 1993b; 

Mills and others, 1998; Kay and others, 2000) indicate 

horizontal flow in the Galena-Platteville aquifer can be 

divided into five zones in the vicinity of the PCHSS. 

Zone 1 is present in the upper 20 ft of the bedrock 

throughout the study area. Flow in zone 1 is through 

the weathered fractures in the upper part of the bedrock 

surface. This zone, as a whole, is highly permeable. 

Zone 2 is about 60-80 ft thick and extends from the 

bottom of the most weathered part of the bedrock to the 

top of the shaley layer at about 662 ft above sea level. 

This zone corresponds to undifferentiated parts of the 

Dubuque and Wise Lake Formations in the study area. 

Horizontal flow in zone 2 is through primarily lowpermeability fractures and vugs, with the exception of 

the fracture at 662 ft, which has variable permeability. 

Zone 3 extends from the bottom of the shaley layer at 

662 ft to immediately above the fracture at about 524 ft 

Table 4. Results of slug testing in test intervals isolated with a 

packer assembly in the vicinity of the Parson’s Casket Hardware 

Superfund site, Belvidere, Ill.

[nc, not calculated]

Borehole

name

Altitude of

test interval

(feet above

sea level)

Depth of

test interval 

(feet below

land surface)

Horizontal

hydraulic

conductivity

(feet per day)

Transmissivity

(feet squared

per day)

G124GP 556-566 218-228 21 nc

G124GP 518-540 243-267 5.26 nc

G130GP 742-747 41-46 360 1,800

G130GP 668-678 110-120 .92 nc

G130GP 658-668 120-130 .36 nc

G130GP 626-636 152-162 .38 nc

G130GP 558-576 212-230 2.9 nc

G133GP 726-733 45-52 6.33 nc

G133GP 667-677 101-111 .76 nc

G133GP 522-532 246-256 5.7 570

G134GP 718-728 55-65 .61 nc

G134GP 692-702 81-91 .26 nc

G134GP 628-638 145-155 .79 nc

G134GP 516-537 246-266 200 nc

G136GP 667-677 105-115 .39 nc

G136GP 637-647 135-145 .57 nc
Ground-Water Quality 25

above sea level and corresponds to the lower part of the 

undifferentiated Dubuque and Wise Lake Formations 

to the upper part of the Grand Detour Formation. 

Horizontal flow in zone 3 is through primarily lowpermeability vugs and fractures, with the exception 

of the fracture at about 564 ft, which has variable 

permeability in the study area. Zone 4 corresponds 

to the subhorizontal fracture near the argillaceous part 

of the Grand Detour Formation at about 524 ft. This 

permeable fracture appears to be present throughout 

the study area and appears to be hydraulically well 

connected to wells BMW4 and BMW6. Zone 5 corresponds to the interval from the bottom of zone 4 to the 

top of the Glenwood semiconfining unit. Zone 5 has 

not been extensively investigated, but flow appears to 

be through low-permeability vugs and fractures, with 

the exception of a subhorizontal fracture in the lower 

part of the Mifflin Formation at about 480 ft above sea 

level (Mills and others, 1998). The permeability of this 

fracture is highly variable within the study area.

In addition to the horizontal flow, vuggy intervals appear to transmit vertical flow in the aquifer. 

Some inclined fractures in the Galena-Platteville 

aquifer provide pathways for vertical flow within and 

between zones 1-4, and perhaps zone 5. Inclined fractures appear to be less permeable with depth (Kay and 

others, 2000), which in combination with the distribution of vugs in the upper part of the aquifer may explain 

why the aquifer above the shaley bed at 662 ft appears 

to have more vertical hydraulic interconnection than 

the aquifer below 662 ft.

GROUND-WATER QUALITY

In each borehole, water samples were collected 

from test intervals isolated with the packer assembly 

(tables 5, 6). An attempt to collect a sample from the 

560-570 ft interval of borehole G136GP was unsuccessful because of the low permeability of this interval. 

Temperature, pH, oxidation-reduction potential (ORP), 

specific conductance, and dissolved oxygen concentration were measured during purging using a calibrated 

water-quality monitor with an attached flow-through 

cell. Using a Hach colorimeter, iron(II) concentrations 

were measured in the field immediately after sample 

collection. All samples were analyzed for concentrations of VOC’s and monitored natural attenuation 

(MNA) parameters. The MNA parameters analyzed 

are methane, ethane, ethene, nitrate, alkalinity, 

chloride, total organic carbon, and iron. The samples 

were collected in September 1999 using a low-capacity 

sampling pump constructed with Teflon and stainlesssteel parts. All samples were collected after at least 

three packed-interval volumes were purged from the 

sample interval, and the samples were preserved, 

stored, shipped, and analyzed in accordance with the 

approved Sampling and Analysis Plan (SAP) for the 

investigation (U.S. Geological Survey, written commun., 1999). Quality-assurance and quality control 

samples; duplicates; and matrix-spike, trip-blank, and 

pump-blank samples were collected as required by the 

SAP. All equipment was decontaminated as required by 

the SAP. Compounds considered to be present because 

of field or laboratory contamination are not presented 

in this report. Where a duplicate sample was collected, 

the highest reported concentration is presented. Results 

of analysis of duplicate samples typically were similar 

to the results of the original-sample analysis. Results of 

analysis of samples collected in April 2000 from the 

monitoring wells completed in boreholes G124GP, 

G130GP, G133GP, G134GP, and G136GP (Ray 

Mastrolonardo, Tetra Tech EM, Inc., written commun., 

2000) were consistent with the results of the analyses 

of the samples collected using the packer assembly.

Volatile Organic Compounds

The total concentration of volatile organic 

compounds (TVOC’s) in water samples collected 

for this investigation ranged from below the practical 

detection limit of about 1 μg/L to 526 μg/L (table 5). 

VOC’s were detected over the entire thickness of the 

aquifer accessible by the boreholes.

The highest concentrations of VOC’s were 

detected at borehole G134GP, near the lateral center of 

the plume in the deep unconsolidated aquifer (fig. 13). 

Lower VOC concentrations were detected around the 

periphery of the plume at boreholes G124GP, G130GP, 

G133GP, and G136GP. The distribution of VOC’s in 

the Galena-Platteville aquifer indicates the bulk of 

the plume is migrating to the southeast toward the 

Kishwaukee River. This distribution of VOC’s and the 

results of the water-level monitoring indicate there also 

are components of flow to the north, east, and possibly 

west in the Galena-Platteville aquifer.

Trichloroethene (TCE) was the VOC detected 

at the highest concentration in the samples from 

boreholes G124GP, G130GP, and G134GP and most 

of the test intervals in borehole G133GP (table 5). 

Tetrachloroethene (PCE) was the VOC detected at 
26 Geology, Hydrology, and Ground-Water Quality of the Galena-Platteville Aquifer in the Vicinity of the Parson’s Casket Hardware Superfund Site, 

Belvidere, Illinois

Table 5. Results of analysis for volatile organic compounds in samples from 

test intervals isolated with a packer assembly in the vicinity of the Parson’s 

Casket Hardware Superfund site, Belvidere, Ill., September 1999

[Compound detected: C2S, carbon disulfide; TCA, 1,1,1-trichlorethane; TCE, trichloroethene; 

PCE, tetrachloroethene; TOL, toluene; 1,2DCE, total 1,2-dichloroethene; 

1,1DCE, 1,1-dichloroethene; 1,1DCA, 1,1-dichloroethane; 4M2P, 4-Methyl-2-Pentone; 

EB-ethylbenzene; XYL, xylene; J, estimated concentrations below detection limit; 

<, less than; ND, not detected]

Borehole

name

Altitude of

test interval

(feet above

sea level)

Volatile organic

compound

detected/concentration

(micrograms per liter)

Total concentration

of volatile organic

compounds

(micrograms per liter)

G124GP 716-747 C2S/17J, TCA/6J, TCE/19,

PCE/2J, TOL/2J

46

658-668 TCE/7J 7

556-566 TCE/4J 4

518-540 TCA/1J, TCE/6J 7

G130GP 742-752 ND <1

558-576 TCE/4J 4

G133GP 726-733 1,2DCE/5J, TCA/4J,

TCE/8J, PCE/11

28

667-677 TCE/1J 1

522-532 1,2DCE/3J, TCA/2J,

TCE/6J, PCE/4J

15

G134GP 718-728 1,1DCE/11J, 1,1DCA/13J,

1,2DCE/9J, TCA/72,

TCE/390, 4M2P/15J,

PCE/12J, TOL/4J

526

692-702 ND <1

662-672 1,1DCE/6J, 1,1DCA/7J,

1,2DCE/5J, TCA/46,

TCE/240, 4M2P/17J,

PCE/8J, TOL/3J

332

628-638 1,1DCE/4J, 1,1DCA/4J,

1,2DCE/4J, TCA/23,

TCE/150, PCE/6J

191

516-537 1,1DCE/4J, 1,1DCA/4J,

1,2DCE/4J, TCA/26,

4M2P/10, TCE/180,

PCE/6J, TOL/7J, EB/1J,

XYL/3J

245

G136GP 742-754 1,2DCE/6J, TCA/1J,

TCE/3J, PCE/16

26

667-677 1,1DCE/2J, PCE/5J 7

637-647 ND <1

520-530 1,2DCE/3J, TCE/1J,

PCE/6J, XYL/1J

11
Ground-Water Quality 27

Table 6. Results of monitored natural attenuation parameter analyses in samples from test intervals isolated with a packer 

assembly in the vicinity of the Parson's Casket Hardware Superfund site, Belvidere, Ill., September 1999

[U, compound not detected and detection limit; J, estimated concentration; na, not analyzed]

Borehole

name

Altitude

of test

interval

(feet above

sea level)

Total

organic

carbon

(milligrams

per liter)

Temperature 

(degrees

Celsius)

Specific

conductance

(microSiemens

per centimeter)

pH

(standard

units)

Oxidationreduction

potential

(millivolts)

Dissolved

oxygen

(milligrams

per liter)

Total

nitrogen

as nitrate

(milligrams

per liter)

G124GP 716-747 0.62U 12.56 759 6.96 19 2.71 3.0

658-668 .62U 11.85 745 6.88 -35 .60 .21

556-566 .62U 11.87 669 7.00 -39 .59 .042J

518-540 .62U 11.74 700 6.83 -2 1.00 .37

G130GP 742-747 .62U 12.47 899 6.78 95 8.34 11.5

558-576 .62U 12.04 811 6.84 -8 .63 8.8

G133GP 726-733 .62U 13.98 741 6.87 68 6.35 4.8

667-677 .62U 12.82 599 6.95 -53 .40 .011U

522-532 .62U 13.02 646 6.90 -4 1.72 2.3

G134GP 718-728 .62U 14.26 801 7.00 -90 .56 .011U

692-702 .62U 13.5 635 6.96 -86 .66 .011U

662-672 .62U 12.63 764 7.00 -54 .30 1.2

628-638 .62U 12.63 743 7.01 -4 .18 1.1

516-537 .62U 12.5 648 6.95 -40 .26 .18

G136GP 742-754 .62U 13.89 913 6.81 102 7.55 6.4

667-677 .62U 13.43 901 6.77 68 .44 3.8

637-647 .62U 12.81 551 6.76 11 .52 .011U

520-530 .62U 13.25 723 6.79 68 4.57 4.1

Borehole

name

Altitude

of test

interval

(feet above

sea level)

Iron (II)

(milligrams

per liter)

Sulfate

(milligrams

per liter)

Methane

(milligrams

per liter)

Alkalinity

(milligrams

per liter)

Chloride

(milligrams

per liter)

Ethane

(milligrams

per liter)

Ethene

(milligrams

per liter)

G124GP 716-747 0.50 74.1 0.075U 366 11.9 0.075U 0.075U

658-668 .90 95.0 .075U 366 17.8 .075U .075U

556-566 .60 61.9 .075U 363 13.8 .075U .075U

518-540 .70 81.2 .075U 363 14.4 .075U .075U

G130GP 742-747 .10 26.4 .075U 324 26.9 .075U .075U

558-576 .60 31.2 .075U 304 21.7 .075U .075U

G133GP 726-733 .80 44.4 .075U 324 49.9 .075U .075U

667-677 .75 44.7 .075U 337 16.2 .075U .075U

522-532 .50 41.1 .075U 332 30.0 .075U .075U

G134GP 718-728 1.80 103.0 .075U 388 47.7 .075U .075U

692-702 1.40 59.8 .075U 338 27.4 .075U .075U

662-672 .60 78.0 .075U 398 47.6 .075U .075U

628-638 na 85.0 .075U 378 48.1 .075U .075U

516-537 .80 63.0 .075U 352 27 .075U .075U

G136GP 742-754 .20 41.9 .075U 342 93.5 .075U .075U

667-677 .10 78.8 .075U 354 80.4 .075U .075U

637-647 .10 36.9 .075U 349 15.8 .075U .075U

520-530 .25 51.1 .075U 342 69.4 .075U .075U
28 Geology, Hydrology, and Ground-Water Quality of the Galena-Platteville Aquifer in the Vicinity of the Parson’s Casket Hardware Superfund Site, 

Belvidere, Illinois

Figure 13. Concentration of trichloroethene in the deep unconsolidated aquifer in the vicinity of the Parson’s Casket Hardware 

Superfund site, Belvidere, Ill. (modified from Science Applications International Corporation, 1993, fig. 3-15).
Ground-Water Quality 29

the highest concentrations at borehole G136GP and 

the shallowest test interval in borehole G133GP. 

Trichloroethane (TCA) was detected in samples from 

every borehole except G130GP. Concentrations of 

TCE or PCE exceed the U.S. Environmental Protection 

Agency (USEPA) Maximum Contaminant Level 

(MCL) of 5 μg/L (U.S. Environmental Protection 

Agency, 1996) in at least one sample from every borehole except G130GP. Both 1,1- and 1,2-dichloroethene 

(collectively referred to as DCE) and dichloroethane 

(DCA) compounds were detected in the samples from 

boreholes G133GP, G134GP, and G136GP. DCE and 

DCA compounds were not detected in the samples 

from boreholes G124GP and G130GP.

TCE was detected in soils at the PCHSS, 

whereas PCE was absent (Science Applications 

International Corporation, 1998), indicating that 

much of the TCE in the ground water is derived 

from the source material at the PCHSS. The presence 

of PCE in ground water in the study area indicates that 

the PCHSS is not the only source of VOC’s in the study 

area. The predominance of PCE over TCE in boreholes 

G133GP and G136GP in the western part of the study 

area may indicate a source of VOC’s in ground water 

west of the PCHSS.

Natural Attenuation Parameters

One important mechanism for natural 

attenuation of chlorinated ethenes and ethanes is 

biodegradation through the process of reductive 

dechlorination. Reductive dechlorination is the 

microbiologically mediated removal of a chlorine atom 

from the chlorinated ethene or chlorinated ethane 

molecule and replacement of the chloride atom with 

a hydrogen atom (fig. 14). Reductive dechlorination 

typically occurs by sequential dechlorination from 

PCE to TCE to DCE to vinyl chloride, to ethene or 

water, carbon dioxide, and chloride (fig. 14). Ethene 

may break down into ethane or methane. The reductive 

dechlorination process for the chlorinated ethane 

compounds is analogous with sequential dechlorination from TCA to DCA to chloroethane to ethanol to 

carbon dioxide.

DCE, DCA, vinyl chloride, and chloroethane 

were detected in ground-water samples collected 

during the current or previous investigations in the 

study area (Science Applications International 

Corporation, 1992; Mills and others, 1998; and Kay 

and others, 2000). DCE and DCA were detected in 

the unconsolidated and Galena-Platteville aquifers 

throughout the study area, whereas vinyl chloride 

and chloroethane were detected only in the shallow 

unconsolidated aquifer and only beneath the PCHSS. 

The absence of DCA, vinyl chloride, and chloroethane 

in the soils at the PCHSS (Science Applications 

International Corporation, 1998) indicates biodegradation of TCE, TCA, and perhaps PCE by reductive 

dechlorination is occurring within the study area. The 

absence of PCE in the soils at the PCHSS indicates 

most of the TCE in ground water in the study area is 

derived from dissolution of TCE in soils and waste 

materials.

Figure 14. Reductive dechlorination sequence for chlorinated ethenes.
30 Geology, Hydrology, and Ground-Water Quality of the Galena-Platteville Aquifer in the Vicinity of the Parson’s Casket Hardware Superfund Site, 

Belvidere, Illinois

Reductive dechlorination requires both electron 

acceptors and an adequate supply of electron donors. 

In an uncontaminated aquifer, native organic carbon is 

used as an electron donor and dissolved oxygen is used 

first as an electron acceptor. After dissolved oxygen is 

consumed, anaerobic organisms typically use nitrate, 

ferric iron oxyhydroxide, sulfate, and finally carbon 

dioxide as electron acceptors. Chlorinated ethenes and 

ethanes compete as electron acceptors in aquifers 

where chlorinated ethenes and ethanes are present in 

sufficient concentrations. The rate of dechlorination 

decreases as the degree of chlorination decreases so 

that PCE is more readily degraded than TCE. TCE is 

more readily degraded than DCE compounds. DCE 

compounds are more readily degraded than vinyl 

chloride. Reductive dechlorination occurs under 

nitrate- and iron-reducing conditions but is most 

rapid and affects the widest range of compounds under 

sulfate reducing and methanogenic conditions. In addition to degradation by reductive dechlorination, vinyl 

chloride can be used as an electron donor and broken 

down to produce carbon dioxide, water, and chloride 

ion. Use of vinyl chloride as an electron donor can 

occur under iron-reducing conditions (Bradley and 

Chapelle, 1997).

Samples from the Galena-Platteville aquifer 

were analyzed for a variety of chemical parameters 

that affect the degree of biodegradation or indicate 

the presence of biodegradation. These parameters 

were used to indicate if biodegradation of chlorinated 

ethenes and ethanes by reductive dechlorination is 

occurring, the locations where biodegradation may 

be occurring, and the degree to which the compounds 

are being degraded.

Organic carbon, the primary electron donor 

in a ground-water system, was not detected in the test 

intervals isolated with a packer assembly (table 6). The 

absence of detectable concentrations of organic carbon 

is likely to be limiting the amount of biodegradation 

of the chlorinated ethenes and ethanes in the GalenaPlatteville aquifer. However, the small amounts of 

toluene, xylene, and ethylbenzene (table 5) also may be 

serving as electron donors in the aquifer (Wiedemeier 

and others, 1998).

Water temperatures in the test intervals isolated 

with a packer assembly ranged from 11.74 to 14.26°C 

(table 6). These values are below 20°C. Above 20°C, 

the biochemical process is accelerated (Wiedemeier 

and others, 1998). Temperatures tended to decrease 

with increasing depth in the aquifer. Temperatures 

were lowest overall in boreholes G124GP and 

G130GP, were intermediate in borehole G134GP, 

and were highest in boreholes G133GP and G136GP. 

These patterns are consistent with the information 

obtained from the temperature logging.

Specific conductance is a measure of the 

capability of a solution to conduct electricity. Although 

specific conductance is not directly correlated to the 

potential for natural attenuation, specific conductance 

typically is related directly to the concentration of ions 

in a solution. Specific conductance of the water in the 

test intervals isolated with a packer assembly ranged 

from 551 to 913 μS/cm (table 6), the mean value 

(the geometric mean value of the geometric mean 

values from each borehole) was 737 μS/cm. Specificconductance values generally decreased with increasing depth. Specific-conductance values at borehole 

G133GP averaged nearly 75 μS/cm below the mean 

and specific conductance values at borehole G130GP 

averaged more than 110 μS/cm above the mean.

pH values of water samples in the test intervals 

isolated with a packer assembly ranged from 6.76 to 

7.01 units (table 6) with a geometric mean value of 

6.88. These values are within the optimal range of 

6-8 pH units for microbial degradation of chlorinated 

ethenes and ethanes (Wiedemeier and others, 1998). 

pH values showed no clear correlation with TVOC 

concentrations. However, the five test intervals with 

the highest concentrations of TVOC’s had higher pH 

values than most of the other test intervals.

The ORP of ground water is a measure of 

electron activity and an indicator of the relative 

tendency of a solution to accept or transfer electrons. 

Reductive dechlorination is possible at ORP values 

below 50 millivolts and is likely at ORP values below 

-100 millivolts (Wiedemeier and others, 1998). These 

values are not absolute but reflect the tendency for 

reductive dechlorination to occur more readily under 

increasingly reducing conditions. ORP values of the 

water in the test intervals isolated with a packer 

assembly ranged from -90 to 102 millivolts (table 6). 

All values at borehole G134GP were negative, whereas 

all values at borehole G136GP were positive. For 

the remaining boreholes, the shallowest interval was 

positive and all of the deeper intervals were negative. 

With the exception of borehole G134GP, ORP values 

were highest in the shallowest packed interval. ORP 

concentrations in the water from the Galena-Platteville 

aquifer tested for this investigation showed no clear 

correlation with concentrations of TVOC’s; however, 
Ground-Water Quality 31

ORP values decreased as TVOC concentrations 

increased above 40 μg/L.

The anaerobic bacteria required for reductive 

dechlorination cannot function at dissolved oxygen 

concentrations greater than about 0.5 mg/L (Wiedemeier and others, 1998). Therefore, dissolved-oxygen 

concentrations greater than 0.5 mg/L tend to suppress 

reductive dechlorination. Concentrations of dissolved 

oxygen in water from the test intervals isolated with a 

packer assembly ranged from 0.18 to 8.34 mg/L 

(table 6). The highest concentrations of dissolved 

oxygen tended to be present in the shallowest test intervals within a given borehole, and the lowest overall 

concentrations were observed at borehole G134GP. 

Dissolved oxygen concentrations showed no clear 

correlation with TVOC concentrations; however, 

dissolved oxygen concentrations decreased as TVOC 

concentrations increased above 40 μg/L.

After dissolved oxygen has been depleted from 

the aquifer, nitrate may be used as an electron acceptor 

for anaerobic biodegradation of organic carbon, including VOC’s. Nitrate concentrations greater than 1 mg/L 

may reduce the amount of dechlorination by competing 

with the chlorinated ethenes and ethanes as an electron 

acceptor (Wiedemeier and others, 1998). Concentrations of nitrogen as nitrate in samples from the test 

intervals isolated with a packer assembly ranged from 

below the detection limit of 0.011 mg/L to 11.5 mg/L 

(table 6). Except for borehole G134GP, nitrogen as 

nitrate concentrations were highest in the uppermost 

interval of the boreholes, lowest in the intermediate 

intervals, and intermediate in the lowermost interval. 

The geometric mean of the concentrations of nitrogen 

as nitrate were as much as an order of magnitude higher 

in borehole G130GP (10.6 mg/L) than concentrations 

in the other boreholes (less than 1.0 mg/L) and 

exceeded the USEPA MCL of 10 mg/L in the shallowest sample (U.S. Environmental Protection Agency, 

1996). Concentrations of nitrogen as nitrate were 

substantially lower in borehole G134GP than in the 

other boreholes. Nitrate concentrations showed no 

clear correlation with TVOC concentrations; however, 

nitrate concentrations decreased as TVOC concentrations increased above 40 μg/L.

Iron(III) may be used as an electron acceptor 

during anaerobic biodegradation of VOC’s and other 

forms of organic carbon, resulting in the reduction of 

iron(III) to iron (II), which may be soluble in water 

(Wiedemeier and others, 1998). Concentrations of 

iron(II) in excess of 1 mg/L may be used as indicators 

of anaerobic degradation of vinyl chloride. Concentrations of iron(II) in samples collected with the packer 

assembly for this investigation ranged from near the 

detection limit of 0.1 mg/L to 1.8 mg/L and showed no 

clear trends with depth (table 6). Iron(II) concentrations were highest in borehole G134GP, intermediate 

at boreholes G124GP and G133GP, and lowest in boreholes G130GP and G136GP. Iron(II) concentrations in 

the water from the Galena-Platteville aquifer tested for 

this investigation showed no clear correlation to TVOC 

concentrations but were highest in the sample with the 

highest TVOC concentrations.

Sulfate may be used as an electron acceptor 

for anaerobic biodegradation after dissolved oxygen 

and nitrate have been depleted from the VOC plume. 

Sulfate concentrations greater than 20 mg/L may 

reduce the amount of dechlorination by competing 

with the chlorinated ethenes and ethanes as an electron 

acceptor (Wiedemeier and others, 1998). Sulfate 

concentrations in the samples collected from the test 

intervals isolated with the packer assembly ranged 

from 26.4 to 103 mg/L and showed no clear trends with 

depth (table 6). Sulfate concentrations were highest in 

boreholes G124GP and G134GP, intermediate in boreholes G133GP and G136GP, and lowest in borehole 

G130GP. Sulfate concentrations showed an overall 

increase with increasing TVOC concentrations.

Concentrations of methane in samples collected 

from the test intervals isolated with a packer assembly 

were below the detection limit of 0.075 mg/L (table 6). 

The absence of methane indicates strongly reducing 

conditions, which are most favorable for reductive 

dechlorination, are not present in the aquifer. In addition, methane is one of the ultimate breakdown products from reductive dechlorination and the absence of 

methane in the aquifer indicates reductive dechlorination is not resulting in the breakdown of the chlorinated 

ethenes and ethanes to their nontoxic end products.

Concentrations of alkalinity in the samples 

collected from the test intervals isolated with a packer 

assembly varied from 304 to 398 mg/L (table 6). 

Alkalinity concentrations show no clear trends with 

depth or location. Carbon dioxide, one of the end 

products produced from the complete degradation 

of chlorinated ethenes and ethanes, can interact 

with carbonate minerals in the aquifer to increase 

ground-water alkalinity; therefore, alkalinity concentrations that are more than twice the background 

concentrations may indicate areas where biodegradation is occurring (Wiedemeier and others, 1998). 
32 Geology, Hydrology, and Ground-Water Quality of the Galena-Platteville Aquifer in the Vicinity of the Parson’s Casket Hardware Superfund Site, 

Belvidere, Illinois

Alkalinity concentrations showed a general increase 

with increasing concentrations of TVOC’s but 

increased by less than a factor of two.

Chloride concentrations in the samples collected 

from the test intervals isolated with a packer assembly 

ranged from 11.9 to 93.5 mg/L, nearly an order of 

magnitude (table 6). Chloride concentrations show no 

clear trends with depth but were highest in borehole 

G136GP; intermediate in borehole G134GP; and 

lowest in boreholes G133GP, G124GP, and G130GP. 

Chloride is one of the end products of reductive dechlorination and tends to be elevated relative to background 

concentrations at an aquifer in which dechlorination of 

substantial amounts of VOC’s is occurring. Chloride 

concentrations in the samples collected for this investigation did not show a correlation with TVOC concentrations. Concentrations of TVOC’s are less than 

1.0 mg/L, and concentrations of chloride exceed 

10 mg/L. Therefore, the lack of correlation between 

concentrations of TVOC’s and chloride does not 

necessarily indicate that dechlorination is not occurring 

in the aquifer.

Concentrations of ethane and ethene in 

samples collected from the test intervals isolated 

with a packer assembly were below the detection 

limit of 0.075 mg/L. Ethane and ethene concentrations 

greater than 0.01 mg/L (which is less than the detection 

limit) are considered indicative of dechlorination of the 

less chlorinated compounds (Wiedemeier and others, 

1998).

Data from previous investigations indicate 

reductive dechlorination of TCE to DCE to vinyl 

chloride and TCA to DCA to chloroethane is occurring 

in the shallow unconsolidated aquifer beneath the 

PCHSS. The VOC and MNA parameters indicate 

reductive dechlorination of PCE, TCE, and TCA to 

DCE and DCA is occurring under either nitrate or 

iron-reducing conditions in the unconsolidated aquifer 

and, perhaps, the upper part of the Galena-Platteville 

aquifer hydraulically upgradient of borehole G134GP. 

This borehole monitors the approximate center of the 

VOC plume emanating from the PCHSS and, apparently, another source area. Whether substantial 

reductive dechlorination is occurring in the GalenaPlatteville aquifer in the vicinity of borehole G134GP 

is not clearly indicated. Oxidizing conditions appear 

to be present at least in the upper part of the GalenaPlatteville aquifer at boreholes G124GP, G130GP, 

G133GP, and G136GP, and reductive dechlorination in 

the Galena-Platteville aquifer at these boreholes is not 

clearly indicated. Reductive dechlorination appears to 

be limited by a lack of organic carbon in the GalenaPlatteville aquifer.

Although the data collected during this 

investigation do not clearly indicate DCE or DCA 

are degrading by reductive dechlorination in the 

Galena-Platteville aquifer, it is possible that DCE 

is being dechlorinated to form vinyl chloride and 

vinyl chloride is being mineralized to carbon dioxide 

through electron donor reactions in the iron-reducing 

part of the unconsolidated deposits and, perhaps, the 

Galena-Platteville aquifer. The absence of detectable 

concentrations of vinyl chloride in the samples 

collected for this investigation may be attributed to 

a lack of production of this compound or, less likely, 

rapid degradation of this compound that prevents its 

accumulation.

SUMMARY AND CONCLUSIONS

The U.S. Geological Survey, in cooperation with 

the Illinois Environmental Protection Agency, used 

packer assemblies in conjunction with geophysical 

logging to characterize the geology, hydrology, and 

distribution of contaminants in the fractured-bedrock 

aquifer in the vicinity of the Parson’s Casket Hardware 

Superfund site in northeastern Belvidere, Ill. The 

bedrock aquifer beneath this part of Belvidere is 

composed of dolomite of the Galena and Platteville 

Groups and is referred to as the Galena-Platteville 

aquifer. This information will be used to assess 

possible remediation scenarios at the site.

Horizontal flow in the Galena-Platteville aquifer 

in the study area can be divided into five zones. Flow in 

zone 1 is through the weathered fractures in the upper 

20 ft (feet) of the bedrock surface. These fractures tend 

to be highly permeable. Zone 2 ranges from about 60 to 

80 ft thick and extends from the bottom of the most 

weathered part of the bedrock to the top of the shaley 

layer at about 662 ft above sea level. This zone corresponds to undifferentiated parts of the Dubuque and 

Wise Lake Formations in the study area. Horizontal 

flow in zone 2 is through primarily low-permeability 

fractures and vugs, with the exception of the fracture at 

662 ft, which has variable permeability. Zone 3 extends 

from just below the shaley layer at 662 ft to immediately above the fracture at 524 ft and corresponds to the 

lower part of the undifferentiated Dubuque and Wise 

Lake Formations through the upper part of the Grand 

Detour Formation. Horizontal flow in zone 3 is through 
References Cited 33

primarily low-permeability vugs and fractures, with 

the exception of the fracture at about 564 ft, which has 

variable permeability in the study area. Zone 4 corresponds to the subhorizontal fracture in the argillaceous 

part of the Grand Detour Formation at about 524 ft. 

This permeable fracture appears to be present throughout the study area and is hydraulically well connected 

to wells BMW4 and BMW6. Zone 5 corresponds to the 

interval from the bottom of zone 4 to the top of the 

Glenwood semiconfining unit. Zone 5 has not been 

extensively investigated but flow appears to be through 

low-permeability vugs and fractures, with the exception of a subhorizontal fracture in the lower part of the 

Mifflin Formation at about 480 ft. This fracture has 

highly variable permeability in the study area. Vugs 

and inclined fractures provide pathways for vertical 

flow within the Galena-Platteville aquifer.

The fractures in the upper 10-20 ft of the bedrock 

at any borehole are likely to be present because of 

weathering and erosion of the bedrock surface. The 

presence of most of the deeper subhorizontal fractures 

appears to be affected by the stratigraphy and lithology 

of the Galena-Platteville deposits.

Water-level data indicate the potential for 

downward flow within the Galena-Platteville aquifer 

throughout the study area. The direction of flow in the 

fracture at about 524 ft above sea level is variable. Flow 

through the fracture is toward the south during periods 

of higher water levels in the fracture that appear to 

occur when pumping in well BMW6 is minimal or 

absent. Flow through the fracture is to the north during 

periods of low water levels in the fracture that appear 

to occur when BMW6 is being pumped and may be 

toward the southwest when well BMW4 is being 

pumped. Water levels in the upper part of the GalenaPlatteville aquifer do not appear to be affected by 

pumping in any of the water-supply wells. Water-level 

data indicate water in the shallow part of the GalenaPlatteville aquifer has the potential to flow into the 

Kishwaukee River and water in the deeper part of the 

aquifer will flow beneath the river.

The total concentration of VOC’s in water 

samples collected from the test intervals isolated with 

the packer assembly ranged from below the practical 

detection limit of 10 μg/L (micrograms per liter) to 

526 μg/L. Chlorinated ethenes were the VOC’s 

detected most often and at the highest concentration. 

VOC’s were detected over the entire sampled depth of 

the aquifer. The lateral center of the VOC plume in the 

Galena-Platteville aquifer is migrating from the 

PCHSS and, apparently, another source area southeast 

toward the Kishwaukee River. There appear to be components of plume movement in the aquifer to the north 

and west.

Reductive dechlorination appears to be occurring under either nitrate or iron-reducing conditions in 

the overlying unconsolidated deposits and, perhaps, the 

upper part of the Galena-Platteville aquifer hydraulically upgradient of borehole G134GP. However, there 

is no clear indication that reductive dechlorination is 

occurring in the Galena-Platteville aquifer in the area 

of the boreholes drilled for this investigation. Reductive dechlorination in the Galena-Platteville aquifer 

appears to be limited by a lack of organic carbon in the 

aquifer.

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HARDWARE SUPERFUND SITE, BELVIDERE, ILLINOIS—U.S. Geological Survey Water-Resources Investigations Report 00–4152

Kay—GEOLOGY, HYDROLOGY, AND GROUND-WATER QUALITY OF THE GALENA-PLATTEVILLE AQUIFER IN THE VICINITY OF THE PARSON’S CASKET 

U.S. GEOLOGICAL SURVEY

221 NORTH BROADWAY AVE.

URBANA, ILLINOIS 61801