Evaluation of Borehole Geophysical Logs 

at the Sharon Steel Farrell Works 

Superfund Site, Mercer County, 

Pennsylvania

by Steven D. McAuley

U.S. Department of the Interior 

U.S. Geological Survey

In cooperation with the U.S. Environmental Protection Agency

Scientific Investigations Report 2004-5193
ii 

U.S. Department of the Interior

Gale A. Norton, Secretary

U.S. Geological Survey

Charles G. Groat, Director

U.S. Geological Survey, Reston, Virginia: 2004

Only available on the World Wide Web at http://pa.water.usgs.gov/pa_pubs.html 

For more information about the USGS and its products: 

Telephone: 1-888-ASK-USGS 

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

endorsement by the U.S. Government.

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

Contents

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

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

Purpose and Scope. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Study Area Location and Physiography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Hydrogeologic Setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Borehole Geophysical Logs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Evaluation of Borehole Geophysical Logs and Well Screen Placement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

T-75 (MW10) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

MR-3310 (MW03D). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

MR-3311 (MW4) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

MR-3312 (MW7) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

MR-3313 (MW01D). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

References Cited. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Figures

1. Map showing location of Sharon Steel Farrell Works Superfund Site and boreholes

logged, near Farrell, Pennsylvania . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2

2. Borehole geophysical logs and water level in borehole T-75 (MW10), collected 

 on April 14, 2003, at Sharon Steel Farrell Works Superfund Site, near Farrell, Pennsylvania. . . . . . .5

3-4. Borehole geophysical logs, water level, and direction of borehole flow under nonpumping

conditions in:

 3. Borehole MR-3310 (MW03D), collected on April 14, 2003 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

4. Borehole MR-3311 (MW4), collected on April 15, 2003 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8

5. Borehole geophysical logs, water level, and direction of borehole flow under

nonpumping and pumping conditions in borehole MR-3312 (MW7), collected

on April 15, 2003 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9

6. Borehole geophysical logs and water level in borehole MR-3313 (MW01D), collected 

on April 15, 2003 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Table

1. Well-identification numbers, latitude and longitude location, depth logged, casing depth,

and geophysical logs collected. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
iv 

Conversion Factors and Datum

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

°F = (1.8 × °C) + 32

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

°C = 5/9 (°F - 32)

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

(NAVD 88).

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

Multiply By To obtain

Length

inch (in.) 2.54 centimeter (cm)

foot (ft) 0.3048 meter (m)

Area

acre 4,047 square meter (m2)

Volume

gallon (gal) 3.785 liter (L)

Flow rate

gallon per minute (gal/min) 0.06309 liter per second (L/s)
Evaluation of Borehole Geophysical Logs

at the Sharon Steel Farrell Works Superfund Site,

Mercer County, Pennsylvania

by Steven D. McAuley

Abstract

On April 14–15, 2003, geophysical logging was conducted 

in five open-borehole wells in and adjacent to the Sharon Steel 

Farrell Works Superfund Site, Mercer County, Pa. Geophysical-logging tools used included caliper, natural gamma, singlepoint resistance, fluid temperature, and heatpulse flowmeter. 

The logs were used to determine casing depth, locate subsurface 

fractures, identify water-bearing fractures, and identify and 

measure direction and rate of vertical flow within the borehole. 

The results of the geophysical logging were used to determine 

the placement of borehole screens, which allows monitoring of 

water levels and sampling of water-bearing zones so that the 

U.S. Environmental Protection Agency can conduct an investigation of contaminant movement in the fractured bedrock. 

Water-bearing zones were identified in three of five boreholes 

at depths ranging from 46 to 119 feet below land surface. Borehole MR-3310 (MW03D) showed upward vertical flow from 71 

to 74 feet below land surface to a receiving zone at 63-68 feet 

below land surface, permitting potential movement of ground 

water, and possibly contaminants, from deep to shallow zones. 

No vertical flow was measured in the other four boreholes.

Introduction

The Sharon Steel Farrell Works Superfund Site is in Mercer County, southwest of Farrell, Pa., at and near the border 

between Ohio and Pennsylvania (fig. 1). The site was a disposal 

area for slag and spent pickle liquor acid (an acidic bath solution, in this case containing hydrochloric, sulfuric, and chromic 

acid, used in industrial cleaning or processing) from the former 

Sharon Steel Corporation Farrell Works, located across the 

Shenango River. 

 Beginning about 1900, the Sharon Steel Corporation used 

the area across the Shenango River, west and southwest of the 

manufacturing plant, to dispose of blast furnace slag, electric 

arc furnace slag, basic oxygen furnace slag, and sludge. From 

1949 to 1981, millions of gallons of spent pickle liquor acid 

were dumped over the slag (CDM Federal Programs Corporation, 2001). It was thought that the acid would partially evaporate and then be neutralized by the slag. Ground-water contamination resulted from this activity. Contaminants detected in 

ground water included arsenic, lead, and chromium (CDM Federal Programs Corporation, 2001).

A Remedial Investigation/Feasibility Study (RI/FS), phase 

2, is being conducted at the Sharon Steel Farrell Works Superfund Site by TetraTech/Black & Veach (TT/B&V). The investigation was focused on the shallow unconsolidated sediments, 

but the U.S. Environmental Protection Agency (USEPA) identified a need to monitor the bedrock aquifer. As part of the 

RI/FS, TT/B&V installed five boreholes to monitor the hydraulic head (water level) and chemical quality of the bedrock aquifer beneath the site (Black & Veach Special Projects Corporation, 2002). Borehole geophysical logging of the five bedrock 

monitor wells was needed to identify water-bearing fractures 

and to determine optimal screen intervals for use by the USEPA 

in determining contaminant movement in the fractured bedrock.

Purpose and Scope

This report describes borehole geophysical logs collected 

by the U.S. Geological Survey (USGS) in five boreholes at the 

Sharon Steel Farrell Works Superfund Site during April 14-15, 

2003 (table 1). The results of borehole geophysical logging and 

flowmeter surveys performed by the USGS were used to 

(1) determine casing depth, (2) locate subsurface fractures, 

(3) identify water-bearing fractures, (4) identify zones of potential vertical flow within the borehole, (5) measure direction and 

rate of vertical borehole flow to monitor and evaluate contaminant movement, and (5) select the most appropriate depths to 

screen boreholes. This information will be used by the USEPA 

in conducting an investigation of contaminant movement in the 

fractured bedrock.
2 Evaluation of Borehole Geophysical Logs at the Sharon Steel Farrell Works Superfund Site, Mercer County, Pennsylvania

Figure 1. Location of Sharon Steel Farrell Works Superfund Site and boreholes logged, near Farrell, Pennsylvania.
Introduction 3

Study Area Location and Physiography

The Sharon Steel Farrell Works Superfund Site is within 

the glaciated section of the Appalachian Plateaus Physiographic 

Province in Mercer County, in western Pennsylvania, on 

400 acres of land within 100 ft of the Ohio border. The site is on 

the Sharon West 7.5-minute USGS quadrangle (fig. 1). The site 

occupies a transition zone between a commercial and industrial 

area to the north and west and the rural and residential areas to 

the west and south of the site. The eastern border of the site is 

formed by the Shenango River, which flows generally in a 

southeasterly direction. Approximately 100 acres of wetlands 

are within the site boundaries. The site is within the 100- and 

500-year floodplains of the Shenango River, and areas of the 

site west and south of the river are higher in elevation than areas 

north and east of the river by 100 ft or more. 

Hydrogeologic Setting

The site is underlain by unconsolidated deposits of sand, 

silt, and clay to depths of 65 to 120 ft. Four hydrostratigraphic 

units have been identified at the site (CDM Federal Programs 

Corporation, 2001). A shallow, unconsolidated aquifer composed of silt and sand occurs at 10 to 30 ft below land surface 

(bls). A silt and clay semi-confining unit underlies the shallow 

aquifer to 20 ft bls. A deep aquifer of sand and gravel, from 70 

to 120 ft bls, underlies the semi-confining unit, and bedrock 

underlies the deep aquifer below 120 ft bls. The bedrock consists of Mississippian age shales and sandstones of the Cuyahoga Group.

Ground water occurs and moves in the pore spaces of the 

unconsolidated sediments and fractures in the bedrock. 

Regional ground-water flow is generally from upland areas to 

valleys; thus, the site situated along the valley of the Shenango 

River is in an area of regional ground-water discharge. Locally, 

ground-water flow in the shallow, unconsolidated aquifer is to 

the east and southeast (CDM Federal Programs Corporation, 

2001). 

Borehole Geophysical Logs

The following geophysical logs were collected by the 

USGS: 

1. caliper, 

2. natural gamma, 

3. single-point resistance (electrical), 

4. fluid temperature, 

5. fluid velocity (heatpulse flowmetering) if borehole flow 

was indicated by the fluid-temperature logs.

Borehole geophysical logs provide information on location and orientation of fractures, water-producing and waterreceiving zones, intervals of vertical borehole flow, quantification of borehole flow, lithologic correlation, and borehole construction. 

Caliper logs record the average borehole diameter, which 

may be related to fractures, lithology, or drilling methods. Caliper logs can be used to identify fractures and possible waterproducing or water-receiving zones and correct other geophysical logs for changes in borehole diameter. Caliper logs also can 

be correlated with fluid-temperature logs and heatpulse flowmetering to further identify fractures and water-producing and 

water-receiving zones. 

The natural-gamma or gamma log measures the naturalgamma radiation (photons) activity, in counts per second, emitted from all rocks. The most common emitters of gamma radiation are uranium-238, thorium-232, their daughter elements, 

and potassium-40. These radioactive elements are concentrated 

in clays by adsorption, precipitation, and ion exchange. Finegrained sediments, such as shale or siltstone, usually emit more 

gamma radiation than sandstone, limestone, or dolomite. The 

gamma log can be collected in the fluid-filled, dry-cased, or 

uncased parts of a borehole. However, casing does reduce the 

gamma response. The gamma log is used to correlate geologic 

units between boreholes (Keys, 1990).

The single-point-resistance log records the electrical resistance of a formation between the probe in a water-filled borehole below casing and an electrical ground at land surface. Generally, electrical resistance increases with formation grain size 

and decreases with borehole diameter, water-producing fractures, and increasing concentration of dissolved solids of borehole water. The single-point-resistance log is used to correlate 

stratigraphy between boreholes and may help identify waterproducing zones (Keys, 1990). 

Table 1. Well-identification numbers, latitude and longitude location, depth logged, casing depth, and geophysical logs collected.

[Logs collected: C, caliper; G, natural gamma; R, single-point resistance;

T, temperature; V, heatpulse flowmeter]

U.S. 

Geological 

Survey 

wellidentification 

number 

(fig. 1)

Site 

number

Latitude/

longitude

(degrees, 

minutes, 

seconds)

Well 

depth 

logged 

(feet 

below 

land 

surface)

Casing 

depth

(feet 

below 

land 

surface) 

Logs 

collected

T-75 MW10 41°12′11′′/

80°31′24′′

76 46 C, G, R, T

MR-3310 MW03D 41°11′38′′/

80°30′21′′

113.7 63 C, G, R, T, V

MR-3311 MW4 41°11′38′′/

80°31′04′′

146 108 C, G, R, T, V

MR-3312 MW7 41°12′06′′/

80°30′50′′

77 20 C, G, R, T, V

MR-3313 MW01D 41°12′00′′/

80°30′28′′

119 119 C, G
4 Evaluation of Borehole Geophysical Logs at the Sharon Steel Farrell Works Superfund Site, Mercer County, Pennsylvania

A fluid-temperature log provides a continuous record of 

the vertical variation of temperature in the water in a borehole. 

Temperature logs are used to identify water-producing and 

water-receiving zones and to determine zones of vertical borehole flow. Intervals of vertical borehole flow are characterized 

by little or no temperature gradient (Williams and Conger, 

1990).

The direction and rate of borehole-water movement was 

determined by the use of a heatpulse flowmeter. The heatpulse 

flowmeter operates by heating a small volume of water between 

two sensitive thermistors (heat sensors) located the same distance from the heat source. A measurement of direction and rate 

is computed when a peak temperature is recorded by one of the 

thermistors. A flexible diverter is used to block the annular 

space around the tool to channel all flow through the measurement channel. The range of flow measurement is about 0.01-

1.5 gal/min in a 2- to 10-in.-diameter borehole (Conger, 1996; 

Keys, 1990).

Some heatpulse-flowmeter measurements may be influenced by (1) poor seal integrity between the borehole and heatpulse flowmeter and (2) contributions of water from storage 

within the borehole. If the seal between the borehole and flowmeter is not complete, some water can bypass the flowmeter, 

resulting in measurements of flow that are less than the actual 

rate. Although the heatpulse flowmeter is a calibrated probe, the 

data are used primarily as a relative indicator to identify waterproducing or water-receiving zones.

In this study, the heatpulse flowmeter was used to identify 

borehole flow under static (nonpumping) conditions at depths at 

which the fluid-temperature logs indicated the possibility of 

flow. An attempt also was made to repeat the flowmeter survey 

while pumping the borehole at a rate of less than 1 gal/min. The 

bedrock boreholes may have low yields (less than 1 gal/min); 

thus, drawdown may not stabilize and flowmetering under 

pumping conditions may not be possible. 

Evaluation of Borehole Geophysical Logs 

and Well Screen Placement 

Locations of boreholes logged are shown in figure 1. The 

locational, borehole-identification, and other data for boreholes 

logged are presented in table 1. 

T-75 (MW10)

The caliper log shows the total depth of the borehole is 

76 ft (fig. 2). The caliper log indicates the borehole is cased with 

4-in.-diameter casing to 46 ft bls. The water level in the borehole at the time of logging was 5.70 ft bls. The measuring point 

(MP) was the top of casing, 1.4 ft above land surface. The caliper log indicates a fracture from about 46.5 to 48.5 ft bls. The 

geologic log indicates silty clay with some coarse sand interbedded from surface to 27 ft bls, weathered shale from 27 to 

44 ft bls, and competent shale from 44 to 76 ft bls (Michael 

Napolitan, Black & Veach Special Projects Corporation, written commun., 2004). The gamma log shows a general increase 

in activity below 45 ft bls because the probe is reading in the 

open uncased part of the borehole. Variations in gamma activity 

from 45 ft bls to the bottom of the borehole probably indicate 

slight differences in sand content within the shale as described 

in the geologic log (Michael Napolitan, Black & Veach Special 

Projects Corporation, written commun., 2004). The singlepoint-resistance log shows decreased electrical resistance at 57 

and 68 ft bls. The single-point-resistance log is a mirror image 

of the gamma log in most places except for the interval from 

about 46 to 47 ft bls. This area may be too close to the casing 

bottom to get a correct reading from the single-point-resistance 

logging tool. The fluid-temperature log is likely showing the 

effect of cooling with depth from near-surface warming; the log 

then shows the effect of the geothermal gradient as temperature 

gradually increases. The heatpulse flowmeter was not run. 

A borehole screen placed from 44 to 54 ft bls would include the 

fracture from 46.5 to 48.5 ft bls.

MR-3310 (MW03D)

The caliper log shows the total depth of the borehole is 

113.7 ft bls (fig. 3). The bottom of the borehole was covered 

with a layer of thick mud. The borehole is cased with 4-in.-

diameter casing to 63 ft bls. The water level in the borehole at 

the time of logging was 1.3 ft bls. The MP was the top of casing, 

2.5 ft above land surface. The caliper log shows a series of fractures from 63 to 68, 71 to 74, and 79 to 82 ft bls. The geologic 

log of the borehole drilling shows silt and clay to 51 ft bls, 

mostly silty sand to 61 ft bls, sandstone to 81 ft bls, siltstone to 

89 ft bls, sandstone to 98 ft bls, and siltstone to 113 ft bls 

(Michael Napolitan, Black & Veach Special Projects Corporation, written commun., 2004). The gamma log shows increases 

in activity interspersed with decreases in activity from 60 to 

113 ft bls. This change in activity indicates silty zones in the 

sandstone and sandy zones in the siltstone. Over the interval 

from 60 to 98 ft bls, gamma activity generally increases. The 

single-point-resistance log is a mirror image of the gamma log. 

The fluid-temperature log generally shows an increase with 

depth. Sudden or sharp changes in temperature, however, occur 

at the fracture zones. Minor temperature increases are shown at 

71-74 and 79-82 ft bls, coinciding with fracture zones indicated 

by the caliper log, and also at 112 ft bls. Under nonpumping 

conditions, the heatpulse flowmeter measured upward flow at 

0.24 gal/min from the fracture at about 71-74 ft bls. Water exits 

the borehole at the fracture at 63-68 ft bls. No flow was measurable at 77, 86, 94, and 104 ft bls (fig. 3), although there was a 

minor turbulence at 94 ft bls. A borehole screen placed from 69 

to 75 ft bls would include the water-producing fracture at 71-

74 ft bls. If the water entering the borehole at the fracture opening from 71 to 74 ft bls is contaminated, cross-contamination of 

the receiving zone could occur. 
DEPTH, IN FEET BELOW LAND SURFACE

NATURAL GAMMA,

IN COUNTS PER 

SECOND

SINGLE-POINT 

RESISTANCE,

IN OHMS

E

Figure 2. Borehole geophysical logs and water level in borehole T-75 (MW10), collected on April 14, 2003, at Sharon Steel Farrell Works Su

Farrell, Pennsylvania (Geologic log from Black & Veach Special Projects Corporation, written commun. 2004). 

0 46

0

8010203040506070

0 100 200

HOLE DIAMETER,

IN INCHES

(CALIPER)

WATER 

TEMPERATURE, 

IN DEGREES CELSIUS

400 800 600 9 11 10

STAT

Lbgb

LITH

5.70

2

5.70

GEOLOGIC

LOG

SILTY CLAY 

WITH SOME 

COARSE SAND INTERBEDDED

WEATHERED 

SHALESHALE

END OF LOG
DEPTH, IN FEET BELOW LAND SURFACE

NATURAL GAMMA,

IN COUNTS PER 

SECOND

SINGLE-POINT 

RESISTANCE,

IN OHMS

HOLE DIAMETER,

IN INCHES

(CALIPER)

WATER 

TEMPERATURE, 

IN DEGREES CELSIUS

0 46

0

120

102030405060708090

100110

0 100 200 0 200 400 6 8 9

EXPLANATION

Figure 3. Borehole geophysical logs, water level, and direction of borehole flow under nonpumping conditions in borehole MR-3310 (MApril 14, 2003, at Sharon Steel Farrell Works Superfund Site, near Farrell, Pennsylvania (Geologic log from Black & Veach Special Projwritten commun. 2004).

2

0.24

1.3

NF

0.24NFNFNFNF

1.3

7

GEOLOGIC

LOG

TRACE SAND

AND ROCK 

FRAGMENTS 

SILTY 

CLAY 

SILTSTONE SILTSTONE 

SILT, 

SANDSTONE,

FINE TO MEDIUM

GRAINED

SANDSTONE,

FINE TO MEDIUM

GRAINED

SILTY SAND 

AND PEBBLES

STATIC WATER LEVEL—Measured in borehole at the time of geophysical 

logging, in feet below land surface. 

BOREHOLE-FLOW MEASUREMENT UNDER NONPUMPING 

CONDITIONS—Circle at depth of flow measurement. Number is measured flow, in gallon per minute. 

DIRECTION OF BOREHOLE FLOW UNDER NONPUMPING CONDITIONS

KNOWN (OR INFERRED) WATER-PRODUCING ZONE U

NONPUMPING CONDITIONS

KNOWN (OR INFERRED) WATER-RECEIVING ZONE UN

NONPUMPING CONDITIONS 

NO FLOW LITHOLOGIC CHANGE

SAND A

SANDSTON

SHAL

PARTIN

END OF LOG
Summary 7

MR-3311 (MW4)

The caliper log shows the total depth of the borehole is 

146 ft bls (fig. 4). The bottom of the borehole was covered with 

a layer of thick mud. The gamma, single-point-resistance, and 

fluid-temperature logs gave readings through the mud to about 

150 ft bls. The borehole is cased with 4-in.-diameter casing to 

108 ft bls. The water level in the borehole at the time of logging 

was 49.23 ft bls. The MP was the top of casing, 3.0 ft above 

land surface. The geologic log indicates sand, sandy silt, and 

silty sand to 100 ft bls, gravel with siltstone and sandstone fragments to 115 ft bls, and siltstone throughout the rest of the borehole (Michael Napolitan, Black & Veach Special Projects Corporation, written commun., 2004). The caliper log shows a 

fracture zone from 108 to 110 ft bls and minor fractures from 

112 to 116 ft bls. The gamma log shows increases in activity 

interspersed with decreases in activity from 111 ft bls to the 

borehole bottom. This change in activity indicates sandy zones 

within the siltstone, probably as interbedded sandstone. The 

single-point-resistance log mirrors the gamma log and indicates 

stratigraphic changes. The fluid-temperature log shows an 

increase in temperature with depth, indicating no vertical borehole flow. A slight change in the slope on the fluid-temperature 

log at 110 ft bls coincides with the major fracture zone indicated on the caliper log, which may indicate minor lateral borehole flow. The fluid-temperature log shows increasing temperature with depth that is indicative of the geothermal gradient. 

Under nonpumping conditions, the heatpulse flowmeter measured no flow at 130 ft bls. A screen set from 108 to 118 ft bls 

would include the major fractures from 108 to 116 ft bls.

MR-3312 (MW7)

The caliper log shows the total depth of the borehole is 

77 ft bls (fig. 5). The borehole is cased with 5-in.-diameter casing to 20 ft bls. The water level in the borehole at the time of 

logging was 7.36 ft bls. The MP was the top of casing, 

0.5 ft bls. The caliper log showed no apparent fracture zones. 

The geologic log indicates silty clay with traces of sand and 

gravel to 20 ft bls and shale from casing bottom to borehole bottom. The gamma log shows increases in activity interspersed 

with decreases in activity from 20 to 77 ft bls that indicate 

sandy zones interspersed within the shale. The single-pointresistance log exhibits an inverse relation with the gamma log. 

The changes in fluid temperature are gradual after initial 

changes from 20 to 23 ft bls, indicating the absence of waterproducing or water-receiving zones. Under nonpumping conditions, the heatpulse flowmeter measured no flow at 34 and 

56 ft bls. A low-volume pump was placed into the borehole at a 

depth of about 19 ft bls. The heatpulse flowmeter was set at 

34 ft bls. No flow was measured at any depth in the borehole. 

The water level did not stabilize even at pumping rates that 

averaged about 0.4 gal/min. Because the casing was below land 

surface and the borehole had no cap, rainwater may have filled 

up the borehole. Under present conditions, the borehole provides little useful information, does not clearly demonstrate a 

connection to a water-bearing zone, and could be abandoned 

and (or) plugged without loss of information about the flow system.

MR-3313 (MW01D)

The caliper log shows the total depth of the borehole is 

119 ft bls (fig. 6). The borehole is cased with 4-in.-diameter 

steel casing to 119 ft bls. The water level in the borehole at the 

time of logging was 5.88 ft bls. The MP was the top of casing, 

2.4 ft above land surface. A casing-depth indicator was run 

along the length of the casing and confirmed that the casing runs 

to 119 ft bls, the entire length of the borehole. The geologic log 

shows gravel to 4 ft bls, sandy silt and silt to 108 ft bls, gravel 

to 115.5 ft bls, and siltstone to 166 ft bls. The geologic log 

reports water at 10 gal/min at 122 ft bls. When drilling at 144 ft, 

the geologists log reports that the upper hole was collapsing. 

The entire hole below casing likely collapsed after the drilling 

tools were removed. Because the borehole was cased to the bottom, no fluid-temperature, single-point-resistance, or heatpulse-flowmeter logs were run. It is not necessary to set a screen 

in this borehole, and plugging of the hole would reduce the 

potential for migration of contaminants along the lower portion 

of the annular seal of the casing.

Summary

On April 14–15, 2003, the USGS, in cooperation with the 

USEPA, logged five boreholes drilled into the bedrock of the 

Mississippian-age Cuyahoga Group at the Sharon Steel Farrell 

Works Superfund Site, near Farrell, Pa. The borehole geophysical logging and flow measurements were conducted to 

(1) determine casing depth, (2) locate subsurface fractures, 

(3) identify water-bearing fractures, (4) identify zones of potential vertical flow within the borehole, (5) measure direction and 

rate of the vertical borehole flow to monitor and evaluate contaminant movement, and (6) select the most appropriate depths 

to screen boreholes. The USEPA will use this information to 

conduct an investigation of contaminant movement in the bedrock.

The boreholes logged ranged from 76 to 150 ft in depth. 

Water-bearing zones were indicated in three of the five boreholes and ranged in depth from 46 to 119 ft bls. Upward vertical 

flow from a water-bearing zone at 71-74 ft bls to a water-bearing zone at 63-68 ft bls was identified with the heatpulse flowmeter in borehole MR-3310 (MW03D) and could permit movement of ground water (and contaminants) from deeper bedrock 

to more shallow water-bearing zones. Optimal screen intervals 

ranged from 44 to 118 ft bls.
DEPTH, IN FEET BELOW LAND SURFACE

NATURAL GAMMA,

IN COUNTS PER 

SECOND

SINGLE-POINT 

RESISTANCE,

IN OHMS

HOLE DIAMETER,

IN INCHES

(CALIPER)

WATER 

TEMPERATURE, 

IN DEGREES CELSIUS

0 8 246 0 200 100

0

160

102030405060708090

100110120130140150

500 1,000 1,500 5 6

E

Figure 4. Borehole geophysical logs, water level, and direction of borehole flow under nonpumping conditions in borehole MR-3311 (MW4on April 15, 2003, at Sharon Steel Farrell Works Superfund Site, near Farrell, Pennsylvania (Geologic log from Black & Veach Special Projration, written commun. 2004).

STBONO LIT

49.23

49.23

NF

NF

GEOLOGIC

LOG

SAND

SAND 

SILTSTONE 

SANDY SILT 

SILTY SAND 

SANDY SILT 

GRAVEL,

SILTSTONE, AND 

SANDSTONE 

FRAGMENTS

NF

END OF LOG
DEPTH, IN FEET BELOW LAND SURFACE

NATURAL GAMMA,

IN COUNTS PER 

SECOND

SINGLE-POINT 

RESISTANCE,

IN OHMS

HOLE DIAMETER,

IN INCHES

(CALIPER)

WATER 

TEMPERATURE, 

IN DEGREES CELSIUS

1 7 3 5

80

5

1015202530354045505560657075

50 200 100 150 100 300 200 0 15 5 10

EX

Figure 5. Borehole geophysical logs, water level, and direction of borehole flow under nonpumping and pumping conditions in borehole M

collected on April 15, 2003, at Sharon Steel Farrell Works Superfund Site, near Farrell, Pennsylvania (Geologic log from Black & Veach SpeCorporation, written commun. 2004).

STATI

in gebe

BORE

MENOCOof 

NO FLNONPPUMP

0.4 

LITHO

NF

7.36

NF

NF

7.36

NF

NF

NP

P

0

GEOLOGIC

LOG

SILTY CLAY,

SHALE 

TRACE SAND, 

GRAVEL 

N

END OF LOG
10 Evaluation of Borehole Geophysical Logs at the Sharon Steel Farrell Works Superfund Site, Mercer County, Pennsylvania

Acknowledgments

The author thanks the U.S. Environmental Protection 

Agency (USEPA) Region III and TetraTech/Black & Veach 

Special Projects Corporation for providing information about 

the study site. Randall Conger and Theodore Buckwalter, both 

of the USGS, are acknowledged for conducting the borehole 

geophysical surveys.

References Cited

Black & Veach Special Projects Corporation, 2002, Draft sampling and analysis plan for Phase 2 Remedial Investigations, 

Sharon Steel–Farrell Works Superfund site, Mercer County, 

Pennsylvania, May 3, 2002: Response Action Contract 

No. 68-87-3-002.

CDM Federal Programs Corporation, 2001, Draft Phase 1 

investigation report for Sharon Steel Farrell Works, Farrell, 

Pennsylvania, April 26, 2001: Document No. 013-RICO03DX.

Conger, R.W., 1996, Borehole geophysical logging for waterresources investigations in Pennsylvania: U.S. Geological 

Survey Fact Sheet 218-95, 4 p.

Keys, W.S., 1990, Borehole geophysics applied to groundwater investigations: U.S. Geological Survey Techniques of 

Water-Resources Investigations, book 2, chap. E2, 150 p.

Williams, J.H., and Conger, R.W., 1990, Preliminary delineation of contaminated water-bearing fractures intersected by 

open-hole bedrock wells: Ground Water Monitoring 

Review, Fall 1990, p. 118-121.

DEPTH, IN FEET BELOW LAND SURFACE

NATURAL GAMMA,

IN COUNTS PER 

SECOND

0 6 4

0

130

10

20

30

40

50

60

70

80

90

100

110

120

20 100 40 60 80

EXPLANATION

Figure 6. Borehole geophysical logs and water 

level in borehole MR-3313 (MW01D), collected on 

April 15, 2003, at Sharon Steel Farrell Works Superfund Site, near Farrell, Pennsylvania (Geologic log 

from Black & Veach Special Projects Corporation, 

written commun., 2004).

STATIC WATER LEVEL—Measured 

in borehole at the time of geophysical logging, in feet below land 

surface. 

LITHOLOGIC CHANGE

5.88

2

5.88

HOLE DIAMETER,

IN INCHES

(CALIPER)

160

140

150

GEOLOGIC

LOG

GRAVEL

SANDY SILT

SILT

SANDY SILT

WITH PEBBLES

GRAVEL

SILTSTONE

BOREHOLE

COLLAPSED

BOREHOLE

COLLAPSED

BOREHOLE

COLLAPSED

END OF LOG PRIOR TO HOLE COLLAPSE