FP-1

BK-371

FP-2

BK-370

FP-7

BK-1324

WH-1

BK-366

WH-2

BK-367

BK-2515

BK-2511

BK-2512

BK-2513

BK-2514

APPROXIMATE SITE

BOUNDARY

U.S. Department of the Interior

U.S. Geological Survey

Scientific Investigations Report 2010–5054

In cooperation with the U.S. Environmental Protection Agency

Changes in Groundwater Flow and Volatile Organic 

Compound Concentrations at the Fischer and Porter 

Superfund Site, Warminster Township, Bucks County, 

Pennsylvania, 1993–2009
Cover. Location of stratigraphic units 2 and 3 at the Fischer and Porter Superfund Site, Warminster Township, Bucks 

County, Pennsylvania. 
Changes in Groundwater Flow and Volatile 

Organic Compound Concentrations at 

the Fischer and Porter Superfund Site, 

Warminster Township, Bucks County, 

Pennsylvania, 1993–2009

By Ronald A. Sloto

In cooperation with the U.S. Environmental Protection Agency 

Scientific Investigations Report 2010–5054

U.S. Department of the Interior

U.S. Geological Survey
U.S. Department of the Interior

KEN SALAZAR, Secretary

U.S. Geological Survey

Marcia K. McNutt, Director

U.S. Geological Survey, Reston, Virginia: 2010

For more information on the USGS—the Federal source for science about the Earth, its natural and living resources, 

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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.

Suggested citation:

Sloto, R.A., 2010, Changes in groundwater flow and volatile organic compound concentrations at the Fischer and Porter Superfund Site, Warminster Township, Bucks County, Pennsylvania, 1993–2009: U.S. Geological Survey Scientific 

Investigations Report 2010–5054, 115 p.
iii

Contents

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

Introduction.....................................................................................................................................................2

Purpose and Scope ..............................................................................................................................2

Well-Identification System..................................................................................................................2

Previous Investigations........................................................................................................................6

Methods of Investigation.....................................................................................................................6

Borehole Logs...............................................................................................................................6

Geophysical Logs................................................................................................................6

Heatpulse-Flowmeter Measurements ............................................................................6

Borehole Television Surveys.............................................................................................7

Aquifer-Isolation Tests................................................................................................................7

Water-Quality Sampling..............................................................................................................7

Hydrogeologic Setting .........................................................................................................................7

Geology..........................................................................................................................................7

Lithostratigraphic Model ..........................................................................................................10

Hydrology ....................................................................................................................................10

Changes in Groundwater Flow ..................................................................................................................16

Effect of Pumping the Fischer and Porter Remediation Wells ....................................................16

Effect of Pumping Public-Supply Wells...........................................................................................19

Horizontal Groundwater Gradients..................................................................................................19

Vertical Groundwater Gradients ......................................................................................................32

Changes in Volatile Organic Compound Concentration ........................................................................42

Horizontal Distribution of Volatile Organic Compounds ...............................................................42

Vertical Distribution of Volatile Organic Compounds....................................................................52

Migration of Volatile Organic Compounds......................................................................................64

Summary and Conclusions.........................................................................................................................67

Acknowledgments.......................................................................................................................................69

References Cited..........................................................................................................................................69

Appendix 1. Chemical Analyses.............................................................................................................71

Appendix 2. Borehole Geophysical Logs............................................................................................101

Appendix 3. Summary of Aquifer-Isolation Tests..............................................................................111
iv

Figures

1. Map showing location of the Fischer and Porter Superfund Site, Warminster

Township, Bucks County, Pennsylvania....................................................................................3

2. Map showing location of wells at the Fischer and Porter Superfund Site,

Warminster Township, Bucks County, Pennsylvania..............................................................4

3. Generalized sketch of straddle-packer assembly and sampling pump in a borehole......8

4. Map showing location of geologic sections at the Fischer and Porter Superfund

Site, Warminster Township, Bucks County, Pennsylvania...................................................11

5. Geologic section A-C at the Fischer and Porter Superfund Site, Warminster

Township, Bucks County, Pennsylvania..................................................................................12

6. Geologic section B-C at the Fischer and Porter Superfund Site, Warminster

Township, Bucks County, Pennsylvania..................................................................................13

7. Geologic section D-F at the Fischer and Porter Superfund Site, Warminster

Township, Bucks County, Pennsylvania..................................................................................14

8. Generalized lithostratigraphy, Fischer and Porter Superfund Site, Warminster

Township, Bucks County, Pennsylvania..................................................................................15

9. Map showing recovery of water levels in deep wells caused by the 1993–94

shutdowns of the remediation wells, Fischer and Porter Superfund Site,

Warminster Township, Bucks County, Pennsylvania............................................................17

10. Map showing recovery of water levels in intermediate-depth wells caused by the

1993–94 shutdowns of the remediation wells, Fischer and Porter Superfund Site,

Warminster Township, Bucks County, Pennsylvania............................................................18

11. Map showing change in water level in deep wells caused by the pumping of the

Warminster Heights supply wells, Fischer and Porter Superfund Site, Warminster

Township, Bucks County, Pennsylvania, 1993–94 .................................................................20

12. Map showing change in water level in intermediate-depth wells caused by the

pumping of the Warminster Heights supply wells, Fischer and Porter Superfund

Site, Warminster Township, Bucks County, Pennsylvania...................................................21

13. Map showing potentiometric surface measured in wells screened in the shallow

zone at the Fischer and Porter Superfund Site, Warminster Township, Bucks

County, Pennsylvania, September 15, 2006 ............................................................................23

14. Map showing potentiometric surface measured in wells screened in the shallow

zone at the Fischer and Porter Superfund Site, Warminster Township, Bucks

County, Pennsylvania, January 16–20, 2007...........................................................................24

15. Map showing potentiometric surface measured in wells screened in the shallow

zone at the Fischer and Porter Superfund Site, Warminster Township, Bucks

County, Pennsylvania, May 21–22, 2009..................................................................................25

16. Map showing potentiometric surface measured in wells screened in the

intermediate zone at the Fischer and Porter Superfund Site, Warminster Township,

Bucks County, Pennsylvania, September 15, 2006................................................................26

17. Map showing potentiometric surface measured in wells screened in the

intermediate zone at the Fischer and Porter Superfund Site, Warminster Township,

Bucks County, Pennsylvania, January 16–20, 2007...............................................................27

18. Map showing potentiometric surface measured in wells screened in the

intermediate zone at the Fischer and Porter Superfund Site, Warminster Township,

Bucks County, Pennsylvania, May 21–22, 2009......................................................................28

19. Map showing potentiometric surface measured in wells screened in the deep zone

at the Fischer and Porter Superfund Site, Warminster Township, Bucks County,

Pennsylvania, September 15, 2006...........................................................................................29
v

20. Map showing potentiometric surface measured in wells screened in the deep 

zone at the Fischer and Porter Superfund Site, Warminster Township, Bucks

County, Pennsylvania, January 16–20, 2007...........................................................................30

21. Map showing potentiometric surface measured in wells screened in the deep zone

at the Fischer and Porter Superfund Site, Warminster Township, Bucks County,

Pennsylvania, May 21–22, 2009 ................................................................................................31

22. Cross section showing water-level altitude and direction of groundwater flow

along section D-C, Fischer and Porter Superfund Site, Warminster Township,

Bucks County, Pennsylvania, September 15, 2006................................................................33

23. Cross section showing water-level altitude and direction of groundwater flow

along section D-C, Fischer and Porter Superfund Site, Warminster Township,

Bucks County, Pennsylvania, May 21–22, 2009......................................................................34

24. Cross section showing water-level altitude and direction of groundwater flow

along section D-C, Fischer and Porter Superfund Site, Warminster Township,

Bucks County, Pennsylvania, December 13, 1993.................................................................35

25. Cross section showing water-level altitude and direction of groundwater flow

along section D-C, Fischer and Porter Superfund Site, Warminster Township,

Bucks County, Pennsylvania, December 15, 1993.................................................................36

26. Cross section showing water-level altitude and direction of groundwater flow

along section E-C, Fischer and Porter Superfund Site, Warminster Township, Bucks

County, Pennsylvania, September 15, 2006 ............................................................................37

27. Cross section showing water-level altitude and direction of groundwater flow

along section E-C, Fischer and Porter Superfund Site, Warminster Township, Bucks

County, Pennsylvania, January 16–20, 2007...........................................................................38

28. Cross section showing water-level altitude and direction of groundwater flow

along section E-C, Fischer and Porter Superfund Site, Warminster Township, Bucks

County, Pennsylvania, December 13, 1993 .............................................................................39

29. Cross section showing water-level altitude and direction of groundwater flow

along section E-C, Fischer and Porter Superfund Site, Warminster Township, Bucks

County, Pennsylvania, December 15, 1993 .............................................................................40

30. Cross section showing water-level altitude and direction of groundwater flow

along section D-E, Fischer and Porter Superfund Site, Warminster Township, Bucks

County, Pennsylvania, December 13, 1993 .............................................................................41

31. Cross section showing water-level altitude and direction of groundwater flow

along section D-E, Fischer and Porter Superfund Site, Warminster Township, Bucks

County, Pennsylvania, January 16–20, 2007...........................................................................43

32. Diagram showing typical reaction pathway for the anaerobic degradation of

tetrachloroethylene and trichoroethylene by reductive dehalogenation.........................46

33. Graph showing concentration of trichloroethylene in monthly water samples from

wells BK-370 and BK-371 (Fischer and Porter 1 and 2), Fischer and Porter

Superfund Site, Warminster Township, Bucks County, Pennsylvania, 1997–2008...........46

34. Graph showing concentration of tetrachloroethylene in monthly water samples from

wells BK-370 and BK-371 (Fischer and Porter 1 and 2), Fischer and Porter

Superfund Site, Warminster Township, Bucks County, Pennsylvania, 1997-2008 ...........47

35. Graph showing concentration of trichloroethylene in monthly water samples from

well BK-1324 (Fischer and Porter 7), Fischer and Porter Superfund Site, Warminster

Township, Bucks County, Pennsylvania, 1997–2008 .............................................................47

36. Graph showing concentration of tetrachloroethylene in monthly water samples from 

well BK-1324 (Fischer and Porter 7), Fischer and Porter Superfund Site, Warminster 

Township, Bucks County, Pennsylvania, 1997–2008 .............................................................48
vi

37. Map showing concentration of trichloroethylene in water samples from wells

completed in the shallow zone, Fischer and Porter Superfund Site, Warminster

Township, Bucks County, Pennsylvania, 1996–2007 .............................................................49

38. Map showing concentration of tetrachloroethylene in water samples from wells

completed in the shallow zone, Fischer and Porter Superfund Site, Warminster

Township, Bucks County, Pennsylvania, 1996–2007 .............................................................50

39. Map showing concentration of cis-1,2-dichloroethylene and

trans-1,2-dichloroethylene in water samples from wells completed in the shallow

zone, Fischer and Porter Superfund Site, Warminster Township, Bucks County,

Pennsylvania, 2007 .....................................................................................................................51

40. Map showing concentration of trichloroethylene in water samples from on-site

wells completed in the intermediate zone and off-site wells completed in the deep

zone, Fischer and Porter Superfund Site, Warminster Township, Bucks County,

Pennsylvania, 1996–2009 ...........................................................................................................53

41. Map showing concentration of tetrachloroethylene in water samples from on-site

wells completed in the intermediate zone and off-site wells completed in the deep

zone, Fischer and Porter Superfund Site, Warminster Township, Bucks County,

Pennsylvnaia, 1996–2009 ...........................................................................................................54

42. Map showing concentration of cis-1,2-dichloroethylene and

trans-1,2-dichloroethylene in water samples from on-site wells completed in the

intermediate zone and off-site wells completed in the deep zone, Fischer and

Porter Superfund Site, Warminster Township, Bucks County, Pennsylvania, 2007.........55

43. Map showing concentration of trichloroethylene in water samples from wells

open to the deep zone, Fischer and Porter Superfund Site, Warminster Township,

Bucks County, Pennsylvania, 1996-2009 .................................................................................56

44. Map showing concentration of tetrachloroethylene in water samples from

wells open to the deep zone, Fischer and Porter Superfund Site, Warminster

Township, Bucks County, Pennsylvania, 1996–2009 .............................................................57

45. Map showing concentration of cis-1,2-dichloroethylene and

trans-1,2-dichloroethylene in water samples from wells open to the deep zone,

Fischer and Porter Superfund Site, Warminster Township, Bucks County,

Pennsylvania, 2007 .....................................................................................................................58

46. Map showing concentration of vinyl chloride measured in water samples from

wells at the Fischer and Porter Superfund Site, Warminster Township, Bucks

County, Pennsylvania, 2007 .......................................................................................................59

47. Cross section showing concentration of trichloroethylene in water samples from

wells along section A-C, Fischer and Porter Superfund Site, Warminster

Township, Bucks County, Pennsylvania, 1996–2007 .............................................................60

48. Cross section showing concentration of tetrachloroethylene in water samples

from wells along section A-C, Fischer and Porter Superfund Site, Warminster

Township, Bucks County, Pennsylvania, 1996–2007 .............................................................61

49. Cross section showing concentration of trichloroethylene in water samples from

wells along section B-C, Fischer and Porter Superfund Site, Warminster

Township, Bucks County, Pennsylvania, 1996–2007 .............................................................62

50. Cross section showing concentration of tetrachloroethylene in water samples

from wells along section B-C, Fischer and Porter Superfund Site, Warminster

Township, Bucks County, Pennsylvania, 1996–2007 .............................................................63

51. Map showing maximum concentration of trichloroethylene in groundwater

samples, Fischer and Porter Superfund Site, Warminster Township, Bucks County,

Pennsylvania, 1979–80 ...............................................................................................................65

52. Diagram showing location of stratigraphic units 2 and 3 at the Fischer and Porter

Superfund Site, Warminster Township, Bucks County, Pennsylvania...............................66
vii

Tables

1. Record of wells at the Fischer and Porter Superfund Site, Warminster Township,

Bucks County, Pennsylvania.......................................................................................................5

2. Volatile organic compounds analyzed in groundwater samples, Fischer and Porter

Superfund Site, Warminster Township, Bucks County, Pennsylvania, 2007–09.................9

3. Changes in water level caused by pumping of the Warminster Heights supply wells

and the shutdown of the Fischer and Porter remediation wells, Fischer and Porter

Superfund Site, Warminster Township, Bucks County, Pennsylvania...............................16

4. Water levels measured at the Fischer and Porter Superfund Site, Warminster 

Township, Bucks County, Pennsylvania, 2006–09 .................................................................22

5. Selected volatile organic compounds analyzed in groundwater, Fischer and Porter

Superfund Site, Warminster Township, Bucks County, Pennsylvania, 2007–09...............44
viii

Conversion Factors and Datums

Inch/Pound to SI

Multiply By To obtain

Length

inch (in.) 2.54 centimeter (cm)

inch (in.) 25.4 millimeter (mm)

foot (ft) 0.3048 meter (m)

mile (mi) 1.609 kilometer (km)

Area

acre 4,047 square meter (m2)

acre 0.4047 hectare (ha)

Volume

gallon (gal) 3.785 liter (L) 

gallon (gal) 0.003785 cubic meter (m3) 

Flow rate

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

Specific capacity

gallon per minute per foot 

[(gal/min)/ft)]

0.2070 liter per second per meter [(L/s)/m]

Hydraulic conductivity

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

Hydraulic gradient

foot per mile (ft/mi) 0.1894 meter per kilometer (m/km)

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

°F=(1.8×°C)+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).

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

Specific conductance is given in microsiemens per centimeter at 25 degrees Celsius (μS/cm at 

25 °C).

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

micrograms per liter (μg/L), or micrograms per kilogram (μg/kg).
Abstract

The 38-acre Fischer and Porter Company Superfund Site 

is in Warminster Township, Bucks County, Pa. Historically, 

as part of the manufacturing process, trichloroethylene (TCE) 

degreasers were used for parts cleaning. In 1979, the Bucks 

County Health Department detected TCE and other volatile 

organic compounds (VOCs) in water from the Fischer and 

Porter on-site supply wells and nearby public-supply wells. 

The Fischer and Porter Site was designated as a Superfund 

Site and placed on the National Priorities List in September 

1983. A 1984 Record of Decision for the site required the 

Fischer and Porter Company to pump and treat groundwater 

contaminated by VOCs from three on-site wells at a combined rate of 75 gallons per minute to contain groundwater 

contamination on the property. Additionally, the Record of 

Decision recognized the need for treatment of the water from 

two nearby privately owned supply wells operated by the 

Warminster Heights Home Ownership Association. In 2004, 

the Warminster Heights Home Ownership Association sold its 

water distribution system, and both wells were taken out of 

service. The report describes changes in groundwater levels 

and contaminant concentrations and migration caused by the 

shutdown of the Warminster Heights supply wells and presents 

a delineation of the off-site groundwater-contamination plume. 

The U.S. Geological Survey (USGS) conducted this study 

(2006–09) in cooperation with the U.S. Environmental Protection Agency (USEPA).

The Fischer and Porter Site and surrounding area are 

underlain by sedimentary rocks of the Stockton Formation of 

Late Triassic age. The rocks are chiefly interbedded arkosic 

sandstone and siltstone. The Stockton aquifer system is 

comprised of a series of gently dipping lithologic units with 

different hydraulic properties. A three-dimensional lithostratigraphic model was developed for the site on the basis of rock 

cores and borehole geophysical logs. The model was simplified by combining individual lithologic units into generalized 

units representing upward fining sedimentary cycles capped 

by a siltstone bed. These cycles were labeled units 1 through 

8 and are called stratigraphic units in this report. Groundwater 

in the unweathered zone mainly moves through a network of 

interconnecting secondary openings—bedding-plane fractures 

and joints. Groundwater generally is unconfined in the shallower part of the aquifer and confined or semiconfined in the 

deeper part of the aquifer.

The migration of VOCs from the Fischer and Porter Site 

source area is influenced by geologic and hydrologic controls. 

The hydrologic controls have changed with time. Stratigraphic 

units 2 and 3 crop out beneath the former Fischer and Porter 

plant. VOCs originating at the plant source area entered these 

stratigraphic units and moved downdip to the northwest. When 

the wells at and in the vicinity of the site were initially sampled in 1979–80, three public-supply wells (BK-366, BK-367, 

and MG-946) and three industrial-supply wells (BK-368, 

BK-370, and BK-371) were pumping. Groundwater contaminated with VOCs flowed downdip and then northeast along 

strike toward well BK-366, downdip toward well BK-368, and 

downdip and then west along strike toward well MG-946. The 

long axis of the TCE plume is oriented about N. 18° W. in the 

direction of dip. In 1979–80, the leading edge of the plume 

was about 3,500 feet wide. With the cessation of pumping of 

the supply wells in 2004, the size of the plume has decreased. 

In 2007–09, the plume was approximately 2,000 feet long and 

2,000 feet wide at the leading edge.

On the western side of the site, TCE and tetrachloroethylene (PCE) appear to be moving downdip though stratigraphic unit 3. The downdip extent of TCE and PCE migration 

extended approximately 550 feet off-site to the northwest and 

750 feet off-site to the north. TCE concentrations in water 

samples from wells at the western site boundary increased 

from 1996 to 2007. On the northern side of the site, TCE and 

PCE appeared to be moving downward and laterally though 

stratigraphic units 2, 3, and 4.

Groundwater-flow directions shifted to the northwest in 

the intermediate and deep zones after cessation of pumping 

of well BK-366 in 2004. The shutdown of the Warminster 

Changes in Groundwater Flow and Volatile Organic 

Compound Concentrations at the Fischer and Porter 

Superfund Site, Warminster Township, Bucks County, 

Pennsylvania, 1993–2009

By Ronald A. Sloto
2 Changes in Groundwater Flow and Volatile Organic Compound Concentrations, Fischer and Porter Superfund Site

Heights wells had little effect on the direction of groundwater 

flow in the shallow zone.

In 2007, TCE concentrations measured in water samples from the three remediation wells by the USGS ranged 

from less than 340 to 3,000 μg/L, and PCE concentrations 

ranged from less than 8.4 to 51 μg/L. TCE concentrations in 

water samples from the source-area remediation wells have 

decreased with time but remain highly variable. From 2001 to 

2008, the TCE and PCE concentrations in water samples from 

wells BK-370 and BK-371 showed a linear decreasing trend. 

TCE and PCE concentrations in water samples from well 

BK-1324 showed an exponentially decreasing trend.

In 2007, TCE concentrations measured in water samples 

from shallow wells ranged from less than 0.1 to 14,000 μg/L, 

and PCE concentrations ranged from less than 0.1 to 340 μg/L. 

The TCE and PCE plumes followed the hydraulic gradient in 

the shallow zone. In 2007, TCE concentrations measured in 

water samples from on-site intermediate-depth monitor wells 

ranged from less than 0.1 to 500 μg/L, and PCE concentrations ranged from 1.3 to 28 μg/L. The TCE and PCE plumes 

followed the hydraulic gradient in the intermediate zone and 

extended off-site to the north and northwest of the source area. 

Concentrations of TCE in water samples north and west of the 

source area increased from 1996 to 2007.

In 2007, the TCE concentrations measured in water 

samples from on-site monitor wells in the deep zone ranged 

from 1.1 to 86 μg/L, and PCE concentrations ranged from 

less than 0.1 to 8.4 μg/L. The TCE and PCE plumes generally 

followed the hydraulic gradient in the deep zone and extended 

off-site to the northwest of the source area. In general, 

concentrations of TCE in water samples from monitor wells 

outside the source area increased between 1996 and 2005 and 

decreased between 2005 and 2007; concentrations were less in 

2007 than in 1996.

Introduction

The Fischer and Porter Company Superfund Site is northeast of the intersection of County Line and Jacksonville Roads 

in Warminster Township, Bucks County, Pa. (figs. 1 and 2). 

County Line Road is the boundary between Bucks and Montgomery Counties. The site occupies approximately 38 acres. 

The main manufacturing facility was constructed in 1940–41. 

Historically, as part of the manufacturing process, three 

trichloroethylene (TCE) degreasers were operated for parts 

cleaning in the main building (CH2M Hill, Inc., 1998, p. 1–2).

In 1979, the Bucks County Health Department detected 

TCE and other volatile organic compounds (VOCs) in water 

from the Fischer and Porter on-site supply wells and from 

nearby public-supply wells operated by the Warminster 

Heights Home Ownership Association and Hatboro Borough. 

The Fischer and Porter Site was designated as a Superfund 

Site and placed on the National Priorities List in September 1983. A 1984 Record of Decision (ROD) for the site 

required the Fischer and Porter Company to pump and treat 

groundwater contaminated by VOCs from three on-site wells 

(wells FP-1, FP-2, and FP-7 on fig. 2) at a combined rate 

of 75 gal/min to contain groundwater contamination on the 

property. Additionally, the ROD recognized the need for treatment of the water from two nearby privately owned supply 

wells operated by the Warminster Heights Home Ownership 

Association (wells WH-1 and WH-2 on fig. 2).

A subsequent ROD issued in 1998 confirmed the contaminant plume was being contained by the combined action of 

the three Fischer and Porter remediation wells and supply well 

WH-1, which influenced the direction of groundwater flow 

and contaminant migration from the site. The 1998 ROD also 

recognized that there was no requirement for the continued 

operation of well WH-1 and, therefore, required re-evaluation 

of the remedy if that well ceased to operate. In 2004, the 

Warminster Heights Home Ownership Association sold its 

water distribution system to the Warminster Municipal Authority, and both Warminster Heights wells were taken out of 

service. Cessation of pumping of these wells caused changes 

to the groundwater-flow system in the vicinity of the Fischer 

and Porter Site. The U.S. Environmental Protection Agency 

(USEPA) requested the assistance of the U.S. Geological Survey (USGS) at the Fischer and Porter Site for the completion 

of the 5-year review initiated in 2004 at the site.

Purpose and Scope

This report presents water-level, water-quality, geophysical, geologic, and aquifer-test data collected for the Fischer 

and Porter Site and vicinity from 2004 to 2009. Water levels 

were measured in 20 on-site and 7 off-site wells. Samples for 

laboratory analysis were collected from 22 on-site and 8 offsite wells. As part of this study, five additional off-site monitor 

wells (wells BK-3042, BK-3043, BK-3044, BK-3045, and 

BK-3046 on fig. 2) were drilled for this study. Geologic logs, 

borehole geophysical logs (caliper, natural-gamma, singlepoint-resistance, fluid-resistivity, and fluid-temperature), and 

heatpulse-flowmeter measurements were collected and aquifer-isolation tests were conducted in these wells. The report 

describes changes in groundwater levels and VOC contaminant concentrations and migration caused by the shutdown of 

the Warminster Heights supply wells in 2004. It also presents a 

delineation of the off-site groundwater-contamination plume.

Well-Identification System

A cross-reference between site and USGS well-identification numbers is given in table 1. Locations of the wells are 

shown on figure 2.
Introduction 3

Figure 1. Location of the Fischer and Porter Superfund Site, Warminster Township, Bucks County, Pennsylvania.

 BUCKS

COUNTY

CHESTER

COUNTY

 LEHIGH

COUNTY

MONTGOMERY

COUNTY

 BERKS

COUNTY

DELAWARE

 COUNTY

PHILADE LPHIA

NORTHAMPTON

COUNTY

75 ̊40’ 75 ̊20’ 75 ̊00’ 74 ̊40’

39 ̊40’

40 ̊00’

40 ̊20’

40 ̊40’

NEW JERSEY

DELAWARE

0 5 10 20 KILOMETERS

0 5 10 15 20 MILES

15

FISCHER AND PORTER

SUPERFUND SITE

Base from U.S. Geological Survey digital data,1972,

1:2,000,000 Albers Equal-Area Conic Projection.

Standard parallels 29 ̊30’N, central meridian 75 ̊00’W. 

PENNSYLVANIA
4 Changes in Groundwater Flow and Volatile Organic Compound Concentrations, Fischer and Porter Superfund Site BK-2526 BK-2523 BK-1793 BK-2827 BK-2810 BK-2811 BK-371 FP-1 BK-370 FP-2BK-1324 FP-7 BK-1030 BK-366 WH-1BK-367 WH-2 BK-1795 BK-2514 BK-2527 BK-2515 BK-2528 BK-2521 BK-2511 BK-1731 BK-2512 BK-2522 BK-2513 BK-2525 BK-2524 BK-2809 BK-1796 BK-372 BK-3034 75 ̊5'40” 75 ̊5'20” 40 ̊11' 40 ̊11'10” APPROXIMATE SITE BOUNDARY 40 ̊11'20”75 ̊06’ BK-3046 BK-3045 MG-946 BK-3043 BK-3042 BK-3044 MG-2149 BK-368

Base from U.S. Geological Survey digital data,1972, 1:2,000,000 Albers Equal-Area Conic Projection. Standard parallels 29 ̊30’N, central meridian 75 ̊00’W. 

0 250 500 FEET

0 50 100 METERS

WELL AND IDENTIFICATION NUMBER –

top number is U.S. Geological Survey

identification number. Bottom numberis local identification number.

MONITOR WELLREMEDIATION WELLOPEN-HOLE WELLABANDONED WELL

BK-371FP-1

 BUCKSCOUNTY

MONTGOMERY

COUNTY

COUNTY LINE ROAD

JACKSONVILLE ROAD

Pennypack Creek

Figure 2. Location of wells at the Fischer and Porter Superfund Site, Warminster Township, Bucks County, Pennsylvania.
Introduction 5

Table 1. Record of wells at the Fischer and Porter Superfund Site, Warminster Township, Bucks County, Pennsylvania.

[USGS, U.S. Geological Survey; USEPA, U.S. Environmental Protection Agency; --, no data; bls, below land surface; OH, open hole; S, screened; D, abandoned]

USGS

identification

number

Owner or owner identification number Depth drilled

(feet)

Casing 

diameter 

(inches)

Open or screened 

interval

(feet bls)

Construction

BK-366 Warminster Heights WH-1 300 8 40–300 OH

BK-367 Warminster Heights WH-2 300 8 56–300 OH

BK-368 La Rosa 2 600 6 -- D

BK-370 Fischer and Porter FP-2 190 6 15–190 OH

BK-371 Fischer and Porter FP-1 474 8 -- OH

BK-372 Fischer and Porter FP-3 601 8 -- D

BK-1030 Warminster Municipal Authority -- 6 -- OH

BK-1324 Fischer and Porter FP-7 300 6 21.4–300 OH

BK-1731 USEPA 300 6 47–65 OH

BK-1793 Fischer and Porter FP-5 40 6 23.4–40 OH

BK-1795 Fischer and Porter FP-8 54 6 23–31 D

BK-1796 Fischer and Porter FP-12 146 6 78–146 D

BK-2511 USEPA 352 4 300–325 S

BK-2512 USEPA 303 4 237–257 S

BK-2513 USEPA 301 4 255–275 S

BK-2514 USEPA 292 8 217–252 S

BK-2515 USEPA 310 4 285–305 S

BK-2521 USEPA 229 4 237–257 S

BK-2522 USEPA 159 4 132–157 S

BK-2523 USEPA 53 4 23.5–43.5 S

BK-2524 USEPA 158 4 115–135 S

BK-2525 USEPA 80 4 31–51 S

BK-2526 USEPA 79 4 50–70 S

BK-2527 USEPA 201 4 157–187 S

BK-2528 USEPA 53.5 4 25–45 S

BK-2809 USEPA PH-3 120 4 18–120 D

BK-2810 USEPA PH-1 120 4 20–120 OH

BK-2811 USEPA PH-2 120 4 10–120 OH

BK-2827 USEPA PH-4 120 4 20–120 OH

BK-3034 -- 300 8 -- D

BK-3042 USEPA 285 2 220–260 S

BK-3043 USEPA 335 2 275–310 S

BK-3044 USEPA 362 10 20–362 D

BK-3045 USEPA 303 2 227–247 S

BK-3046 USEPA 355 2 280–310 S

MG-946 Hatboro Authority H-16 300 10 42–300 D

MG-2149 Delaware Valley Concrete Company -- -- -- OH
6 Changes in Groundwater Flow and Volatile Organic Compound Concentrations, Fischer and Porter Superfund Site

Previous Investigations

The geology and hydrology of the Stockton Formation in 

southeastern Pennsylvania was described by Rima and others 

(1962). In the Hatboro area, it was described by Sloto and 

others (1996). Sloto and Davis (1983) described the effect of 

urbanization on the water resources of Warminster Township. 

Groundwater studies at the Fischer and Porter Site include 

those by SMC Martin, Inc. (1980), BCM, Inc. (1986), Sloto 

and others (1995), CH2M Hill, Inc. (1998), and TetraTech 

EM, Inc. (2005).

Methods of Investigation

Data collected for this study include geophysical, geological, water-level, and water-quality data. A description of 

how the data were collected is presented below.

Borehole Logs

For this study, borehole logs were collected in wells 

BK-3042, BK-3043, BK-3044, BK-3045, and BK-3046. 

Borehole logs include geophysical logs, heatpulse-flowmeter 

measurements, and borehole television surveys.

Geophysical Logs

For this study, caliper, natural-gamma, single-pointresistance, fluid-resistivity, and fluid-temperature borehole 

geophysical logs and heatpulse-flowmeter measurements were 

collected in five boreholes (BK-3042, BK-3043, BK-3044, 

BK-3045, and BK-3046). Borehole geophysical logs are presented in appendix 2. The logs were used to locate water-producing fractures, determine the rate and direction of vertical 

movement of water in the borehole, and determine intervals to 

be isolated by straddle packers for the aquifer-isolation tests.

Caliper logs provide a continuous record of average 

borehole diameter, which is related to fractures, lithology, and 

drilling technique. Caliper logs were used to identify fractures 

and possible water-producing openings. Correlation of caliper 

logs with fluid-resistivity and fluid-temperature logs was used 

to identify water-producing and water-receiving fractures or 

fracture zones. The term fracture used in association with the 

caliper-log interpretations might identify a change in borehole 

diameter that may not necessarily indicate a bedding-plane 

separation, lithologic contact, or water-producing or waterreceiving zone but may simply indicate an enlargement of the 

borehole.

Natural-gamma logs, also called gamma-ray logs, record 

the natural-gamma radiation emitted from rocks penetrated 

by the borehole. Uranium-238, thorium-232, and the progeny 

of their decay series and potassium-40 are the most common emitters of natural-gamma radiation. These radioactive 

elements are concentrated in clays by adsorption, precipitation, and ion exchange. Fine-grained sediments, such as 

mudstone or siltstone, usually emit more gamma radiation 

than sandstone. Geophysical logging with a gamma probe can 

be conducted in the water-filled, dry, cased, or uncased parts 

of the borehole (Keys, 1990). However, casing reduces the 

gamma response. The gamma logs were used to help correlate 

lithologic units between boreholes.

Single-point-resistance logs record the electrical resistance between the borehole and an electrical ground at land 

surface. In general, resistance increases with grain size and 

decreases with borehole diameter, density of water-producing 

fractures, and increasing dissolved-solids concentration 

of borehole water (Keys, 1990). A water-filled borehole is 

required for single-point-resistance logs, and they are run 

only for the saturated part of the formation below the casing. 

Single-point-resistance logs were used to help correlate lithology between boreholes and to help identify water-producing 

fractures or fracture zones.

Fluid-resistivity logs measure the electrical resistance of 

the water in the borehole. Resistivity is the reciprocal of fluid 

conductivity, and fluid-resistivity logs reflect changes in the 

dissolved-solids concentration of the borehole water. Fluidresistivity logs were used to identify water-producing and 

water-receiving zones and to determine intervals of vertical 

borehole flow. Water-producing and water-receiving zones 

usually are identified by sharp changes in resistivity. Intervals 

of vertical borehole flow usually are identified by a lowresistivity gradient between a water-producing and a waterreceiving zone.

Fluid-temperature logs provide a continuous record of the 

vertical water-temperature variation in the borehole. Fluidtemperature logs were used to identify water-producing and 

water-receiving zones and to determine intervals of vertical 

borehole flow. Water-producing and water-receiving zones 

usually are identified by sharp changes in temperature, and 

intervals of vertical borehole flow are identified by little or no 

temperature gradient.

Heatpulse-Flowmeter Measurements

The direction and rate of borehole-fluid movement 

were measured with a high-resolution heatpulse flowmeter. 

Heatpulse-flowmeter measurements are presented in appendix 2. The heatpulse flowmeter operates by diverting nearly 

all flow to the center of the tool where a heating grid slightly 

heats a thin zone of water. If vertical borehole flow is occurring, the water moves up or down the borehole to one of two 

sensitive thermistors (heat sensors). When a peak temperature is recorded by one of the thermistors, a measurement of 

direction and rate is calculated by the computer collecting 

the logging data. The range of flow measurement for this tool 

is about 0.01 to 1.5 gal/min in an 8-in. diameter borehole. 

Heatpulse-flowmeter measurements may be affected by poor 

seal integrity between the borehole and the flowmeter. If the 

seal between the borehole and the heatpulse flowmeter is not 

complete, some water can bypass the flowmeter, resulting 

in flow measurements that are less than the actual rate. The 
Introduction 7

quantity of water bypassing the tool is a function of borehole 

size and shape and degree of fracturing. Although the heatpulse flowmeter is a calibrated tool, the data primarily are used 

as a relative indicator of water-producing zones.

Borehole Television Surveys

Borehole television surveys were conducted by lowering 

a waterproof video camera down the borehole and recording 

the image on video tape. The borehole television surveys were 

used to characterize water-producing fractures and to locate 

smooth sections of borehole to set the packers.

Aquifer-Isolation Tests

Because most groundwater flow and contaminant movement at the Fischer and Porter Site occurs in distinct waterbearing fractures rather than through primary openings in 

the rock, it is important to define the hydraulic and chemical 

characteristics of important, discrete water-bearing fractures. 

This characterization only can be performed by isolating each 

water-bearing fracture with straddle packers so that its properties can be separated from the other water-bearing fractures in 

the borehole. These tests are called aquifer-isolation tests and 

commonly are referred to as packer tests. Aquifer-isolation 

tests were conducted in five boreholes (BK-3042, BK-3043, 

BK-3044, BK-3045, and BK-3046). Data from aquifer-isolation tests are summarized in appendix 3.

The straddle-packer assembly (fig. 3) consisted of two 

inflatable rubber bladders (packers) about 4 ft long set on 

2-in.-diameter lift pipe with a pump set between the packers. 

The distance from the center of the upper packer to the center 

of the lower packer varied.

Several aquifer-isolation tests were conducted in each 

borehole. Intervals selected for aquifer-isolation tests were 

based on the borehole geophysical logs and borehole television surveys. The packer assembly was lowered to the selected 

depth in the borehole, and the packers were inflated against the 

borehole wall, isolating the selected interval. Exact depths to 

set packers were based on the location of smooth sections of 

borehole wall determined from the caliper logs and borehole 

television surveys. For the test of most intervals, both packers were inflated (B on fig. 3). For the test of the lowermost 

isolated interval in most boreholes, only the upper packer was 

inflated (A on fig. 3). For the test of the uppermost isolated 

interval in all boreholes, only the lower packer was inflated 

(C on fig. 3). Inflation of both packers created three intervals—an upper interval above the upper packer, the isolated 

interval between the packers, and a lower interval below the 

lower packer. Pressure in the packers was monitored continuously so that the packers always remained at maximum 

inflation. After the packers were inflated, water levels in each 

interval usually were allowed to stabilize before pumping 

began. Water levels were recorded above, below, and in the 

isolated interval.

During aquifer-isolation tests, measurements of water 

levels were made in each interval by calibrated pressure 

transducers and recorded by a digital data logger. Water levels 

initially were determined by electric measuring tapes; these 

water levels were used to calibrate the transducers. The transducers were set in measurement tubes open to the monitored 

intervals. The accuracy of the transducer in the isolated interval was ± 0.06 ft. The accuracy of the transducers used in the 

intervals above and below the isolated interval was ± 0.03 ft. 

Calibrated, in-line flowmeters were used to measure discharge. 

The water was treated by a granulated active carbon filtration 

system before discharge.

The specific capacity of each isolated interval was calculated by dividing the pumping rate by the drawdown. The specific capacity for each isolated interval is given in appendix 3. 

Water samples were collected prior to the end of each test by 

opening a sampling port in the discharge line before the flowmeter and the activated carbon treatment system. This caused 

the pumping rate to increase and the water level to decline. 

The specific capacity was determined using the drawdown just 

prior to sampling. Specific capacity is affected by the pumping 

rate and the length of pumping. In general, a higher pumping 

rate and (or) a longer pumping duration will result in a lower 

specific capacity.

Water-Quality Sampling

Water samples were collected for laboratory analysis for 

VOCs (table 2). Water-quality data are presented in appendix 1. Most wells were purged a minimum of three volumes 

before collecting the sample. Approximately two volumes 

were purged from wells WH-1 and WH-2. Well BK-3034 was 

flowing when sampled. Well MG-2149 was pumping when 

sampled. Sampled wells were purged until field determinations 

(dissolved oxygen, pH, specific conductance, and temperature) 

stabilized. Purge water was treated by a granulated active carbon filtration system before discharge. Samples were collected 

in 40-milliliter septum bottles, placed on ice, and shipped 

overnight to the USGS laboratory in Arvada, Colo.

Hydrogeologic Setting

The Fischer and Porter Site is in the Gettysburg-Newark 

Lowlands Section of the Piedmont Physiographic Province. 

The site and surrounding area are underlain by sedimentary 

rocks of the Stockton Formation of Late Triassic age.

Geology

The Stockton Formation is the basal unit of the Newark 

Supergroup rocks in the Triassic-Jurassic Newark Basin. The 

Stockton Formation is subdivided into three units called the 

lower arkose, middle arkose, and upper shale members by 

Rima and others (1962). The rocks that underlie the Fischer 

and Porter Site belong to the middle arkose member. The 
8 Changes in Groundwater Flow and Volatile Organic Compound Concentrations, Fischer and Porter Superfund Site

Figure 3. Generalized sketch of straddle-packer assembly and sampling pump in a borehole.

OPEN BOREHOLE BELOWISOLATEDINTERVAL

(NOT INFLATED)

LAND SURFACE

SAMPLING PUMPDISCHARGE LINE

DRILL STEM

CASING

SCREEN

OPEN BOREHOLE ABOVEISOLATEDINTERVAL

UPPER PACKER (INFLATED)SAMPLING PUMP

ISOLATEDINTERVAL 

LOWER PACKER (INFLATED) OPEN BOREHOLE 

BELOWISOLATEDINTERVAL

B BOTH PACKERS INFLATED

LAND SURFACE

SAMPLING PUMPDISCHARGE TUBE

DRILL STEM

CASING

TRANSDUCER ORWATER-LEVELMEASUREMENT TUBESUPPER PACKER (NOT INFLATED)SCREENSAMPLING PUMPLOWER PACKER (INFLATED)

C LOWER PACKER INFLATED

NOT TO SCALE

A UPPER PACKER INFLATED

TRANSDUCER ORWATER-LEVELMEASUREMENT TUBES

ISOLATEDINTERVAL 

WATER LEVEL WATER LEVEL

LAND SURFACE

SAMPLING PUMPDISCHARGE LINE

DRILL STEM

CASING

SCREEN

OPEN BOREHOLE ABOVEISOLATEDINTERVAL

UPPER PACKER (INFLATED)SAMPLING PUMP

ISOLATEDINTERVAL 

TRANSDUCER ORWATER-LEVELMEASUREMENT TUBES

LOWER PACKER 

WATER LEVEL
Introduction 9

Table 2. Volatile organic compounds analyzed in groundwater samples, Fischer and Porter Superfund Site, Warminster Township, 

Bucks County, Pennsylvania, 2007–09.

[CAS, Chemical Abstracts Service; μg/L, micrograms per liter]

CAS registry number Compound Reporting limit

(μg/L) Synonym or abbreviation

71-55-6 1,1,1-Trichloroethane 0.1 TCA

76-13-1 1,1,2-Trichlorotrifluoroethane .1 Freon 113

75-34-3 1,1-Dichloroethane .1 1,1-DCA

75-35-4 1,1-Dichloroethylene .1 1,1-DCE

95-50-1 1,2-Dichlorobenzene .1

107-06-2 1,2-Dichloroethane .2 1,2-DCA

156-59-2 cis-1,2-Dichloroethylene .1 cis-1,2-DCE

156-60-5 trans-1,2-Dichloroethylene .1 trans-1,2-DCE

78-87-5 1,2-Dichloropropane .1

541-73-1 1,3-Dichlorobenzene .1

106-46-7 1,4-Dichlorobenzene .1

123-91-1 1,4-dioxane1 2.88 p-dioxane

67-64-1 Acetone 1.8

71-43-2 Benzene .1

75-27-4 Bromodichloromethane .1

75-25-2 Bromoform .2

56-23-5 Carbon tetrachloride .2 Tetrachloromethane

108-90-7 Chlorobenzene .1

67-66-3 Chloroform .1

124-48-1 Dibromochloromethane .2 Chlorobromoform

75-71-8 Dichlorodifluoromethane .2 Freon 12

75-09-2 Dichloromethane .2 Methylene chloride

60-29-7 Diethyl ether .2

108-20-3 Diisopropyl ether .2

100-41-4 Ethylbenzene .1

637-92-3 Ethyl tert-butyl ether .1

79-20-9 Methyl acetate .4

994-05-8 Methyl-tert-pentyl ether .2

100-42-5 Styrene .1

75-65-0 Tert-butyl alcohol 1

637-92-3 Tert-butyl ethyl ether .04

1634-04-4 Tert-butyl methyl ether .2 MTBE

127-18-4 Tetrachloroethylene .1 PCE

108-88-3 Toluene .1

79-01-6 Trichloroethylene .1 TCE

75-69-4 Trichlorofluoromethane .2 Freon 11

75-01-4 Vinyl chloride .2 VC

108-38-3 m-Xylene .2

1

Sampled only for the remediation wells.
10 Changes in Groundwater Flow and Volatile Organic Compound Concentrations, Fischer and Porter Superfund Site

Stockton Formation is 6,000 ft thick near the Bucks and Montgomery County boundary; the middle arkose member accounts 

for 70 percent of its thickness. In the vicinity of the Fischer 

and Porter Site, the Stockton Formation strikes approximately 

N. 65° E. and dips approximately 9° NW. (Sloto and others, 

1992). The rocks are chiefly interbedded arkosic sandstone 

and siltstone.

Lithostratigraphic Model

The lithostratigraphic model of the Fischer and Porter 

Site was developed by Sloto and others (1995). Lithostratigraphic interpretations and correlations were based on the 

response of borehole geophysical logs collected in on-site 

boreholes to lithology. Because the lithologic units of the 

Stockton Formation grade, interfinger, and coalesce, none of 

the units could be used as marker beds within the lithostratigraphic sequence. The lithology was first interpreted from 

three continuous rock cores collected at the site. Subsequently, 

a best fit was made to construct the lithostratigraphic model 

using the borehole geophysical logs. The interpreted lithology 

of each borehole was initially developed from correlation with 

rock cores and then extended along strike or dip to the nextnearest borehole location to correlate lithostratigraphy. Some 

lithostratigraphic units correlate above or below the expected 

projection line, probably because of the lens-like structures 

characteristic of the alluvial-fan depositional environment. 

Correlations between boreholes generally are consistent with 

strike and dip but show some thinning and thickening of the 

units across the area. The accuracy of the correlations deteriorate near land surface because of the absence of singlepoint-resistance measurements and dampened natural-gamma 

response caused by casing. The lithostratigraphic model was 

extended off-site using borehole geophysical logs collected in 

the five off-site boreholes (appendix 2) drilled for this study.

The three-dimensional model of the lithostratigraphy developed by Sloto and others (1995, plates 1–3) was 

simplified by combining individual lithologic units into 

generalized sedimentary cycles. Some of the siltstone units 

are continuous under the entire site and can be traced from 

borehole to borehole. The areally extensive siltstone units 

are the tops of poorly defined, upward-fining sedimentary 

cycles. These cycles were labeled (unit 3, for example) and are 

called stratigraphic units in this report. Grouping individual 

beds into sedimentary cycles simplifies the geologic framework and more easily permits tracing of the lithology from 

borehole to borehole.

The interpreted generalized lithostratigraphy was projected along two lines (A-C and B-C) approximately parallel 

to the dip direction and one line (D-F) approximately parallel to strike (fig. 4). Section A-C extends southeastward from 

well BK-3046 to well BK-2514 (fig. 5). Section B-C extends 

southeastward from well BK-3044 to well BK-2514 (fig. 6). 

Section D-F extends northeastward from well BK-2511 to well 

BK-3042 (fig. 7). The cross sections were combined to form a 

fence diagram for the site (fig. 8).

Hydrology

The rocks of the Stockton Formation form a complex, 

heterogeneous, multiaquifer system. This aquifer system is 

comprised of a series of gently dipping lithologic units with 

different hydraulic properties. The groundwater system can be 

visualized as a series of beds with a relatively high transmissivity separated by beds with a relatively low transmissivity. 

The beds, a few inches to a few feet thick, act as a series of 

alternating aquifers and confining or semiconfining units that 

form a leaky, multiaquifer system. Each bed generally has different hydraulic properties, and permeability commonly differs 

from one bed to another. Lithology and hydraulic properties 

may change over short horizontal and vertical distances.

In the Stockton Formation, some groundwater moves 

through intergranular openings in the weathered zone that 

have formed as a result of weathering. In some places, permeability of the weathered zone may be poor because of a high 

percentage of clay derived from weathering of siltstone. Most 

of the groundwater moves through the unweathered zone 

through a network of interconnecting secondary openings—

bedding-plane fractures and joints. Beds within the Stockton 

Formation are hydraulically connected by steeply dipping 

joints that cross each other at various angles.

Some water-bearing openings may be slightly enlarged 

by circulating groundwater that has decomposed and disintegrated mineral constituents in the walls of fractures. Primary 

porosity that may have originally existed has been almost 

eliminated by compaction and cementation. Some water may 

move through intergranular openings in the rock below the 

weathered zone where the cement has been removed and the 

permeability has increased, but this generally is restricted to a 

few coarse-grained sandstone and conglomerate beds. Laboratory hydraulic conductivities were determined for a rock 

core collected 0.5 mi south of the Fischer and Porter Site. Red 

siltstone had a hydraulic conductivity of 5.14 × 10-7 ft/d; red, 

silty, fine-grained sandstone had a hydraulic conductivity of 

2.92 × 10-6 ft/d; gray, fine-grained sandstone had a hydraulic 

conductivity of 1.18 × 10-4 ft/d; and medium- to coarsegrained sandstone (with some cement removed) had a hydraulic conductivity of 0.19 ft/d (Sloto and others, 1996).

Groundwater generally is unconfined in the shallower 

part of the aquifer and confined or semiconfined in the deeper 

part of the aquifer. Differences in the ratio of vertical to horizontal hydraulic conductivity, as well as differences in vertical 

hydraulic conductivity within and among lithologic units, create confining conditions.

Boreholes may penetrate several water-producing zones 

with different hydraulic properties. Each water-producing 

zone usually has a different hydraulic head (water level). The 

head in a deep, open-hole borehole is the composite of the 

heads in the water-producing zones penetrated. This can cause 

heads in some boreholes to be different than heads in adjacent 

boreholes of different depths. Where differences in head exist 

between water-producing zones, water flows in the direction 

of decreasing head. Where the hydraulic head is greater than 
Introduction 11

Figure 4. Location of geologic sections at the Fischer and Porter Superfund Site, Warminster Township, Bucks County, 

Pennsylvania.

BK-1324

BK-2514

BK-2515

BK-2511

BK-2512

75°5'40” 75°5'20”

40°11'

40°11'10”

APPROXIMATE SITE

BOUNDARY

40°11'20”

75°6’

BK-3046

BK-3045

BK-3043

BK-3042

BK-3044

JACKSONVILLE ROAD

COUNTY LINE ROAD

0 250 500 FEET

0 50 100 METERS

BK-2511 WELL AND U.S. GEOLOGICAL SURVEY

WELL-IDENTIFICATION NUMBER

A C LINE OF GEOLOGIC SECTION

C

A

B

D

E

F

Base from U.S. Geological Survey digital data,1972, 1:2,000,000 Albers Equal-Area Conic Projection.

Standard parallels 29°30’N, central meridian 75°00’W.
12 Changes in Groundwater Flow and Volatile Organic Compound Concentrations, Fischer and Porter Superfund Site

Figure 5. Geologic section A-C at the Fischer and Porter Superfund Site, Warminster Township, Bucks County, Pennsylvania. Location of line of section shown on figure 4.

UNIT 7

BK-2515

BK-2511

BK-1324

C

BK-2514

UNIT 1

UNIT 4

UNIT 5

UNIT 6

UNIT 3

UNIT 8

BK-3045

BK-3046

UNIT 2

UNIT 3

UNIT 4

UNIT 5

UNIT 6

UNIT 1

UNIT 2

UNIT 3

UNIT 4

A

0 200 400 300 500 FEET 100

0 100 METERS 50

HORIZONTAL SCALE BK-2511 WELL-IDENTIFICATION NUMBER

UNIT 3 GENERALIZED STRATIGRAPHIC UNIT –

Each unit represents an upward-finingsedimentary sequence capped by a siltstoneunit

-100

-20-40-60-80

0

80604020

300280260240220200180160140120100

ELEVATION, IN FEET ABOVE NORTH AMERICAN VERTICAL DATUM OF 1988 -120 -140

D

VERTICAL EXAGGERATION X 2.7
Introduction 13 Figure 6. Geologic section B-C at the Fischer and Porter Superfund Site, Warminster Township, Bucks County, Pennsylvania. Location of line of section shown on figure 4.

BK-2514

BK-1324

UNIT 4

UNIT 5

UNIT 6

UNIT 8

UNIT 7

UNIT 1

UNIT 2

UNIT 3

UNIT 4

UNIT 5

BK-3043

UNIT 1

UNIT 5

UNIT 2

UNIT 3

UNIT 4

B

BK-3044

C

0 200 400 300 500 FEET 100

0 100 METERS 50

HORIZONTAL SCALE

BK-2512 WELL-IDENTIFICATION NUMBER

UNIT 3 GENERALIZED STRATIGRAPHIC UNIT –

Each unit represents an upward-finingsedimentary sequence capped by a siltstoneunit

-100

-20-40-60-80

0

80604020

300280260240220200180160140120100

ELEVATION, IN FEET ABOVE NORTH AMERICAN VERTICAL DATUM OF 1988 UNIT 3 UNIT 6

BK-2512

E

VERTICAL EXAGGERATION X 2.9
14 Changes in Groundwater Flow and Volatile Organic Compound Concentrations, Fischer and Porter Superfund Site

Figure 7. Geologic section D-F at the Fischer and Porter Superfund Site, Warminster Township, Bucks County, Pennsylvania. Location of line of section shown on figure 4.

D

F

WELL-IDENTIFICATION NUMBER

UNIT 5

-100

-20-40-60-80

0

80604020

300280260240220200180160140120100

BK-2511

UNIT 1UNIT 2UNIT 3UNIT 4

UNIT 6

BK-3042

ELEVATION, IN FEET ABOVE NORTH AMERICAN VERTICAL DATUM OF 1988 

0 200 400 300 500 FEET 100

0 100 METERS 50

HORIZONTAL SCALE

BK-2512

UNIT 3 GENERALIZED STRATIGRAPHIC UNIT –

Each unit represents an upward-finingsedimentary sequence capped by a siltstoneunit

VERTICAL EXAGGERATION X 2.7

BK-2512

E
Introduction 15Figure 8. Generalized lithostratigraphy, Fischer and Porter Superfund Site, Warminster Township, Bucks County, Pennsylvania.

FP-1BK-371

FP-2BK-370

FP-7BK-1324

WH-1BK-366

WH-2BK-367

BK-2515

BK-2511

BK-2512

BK-2513 BK-2514

APPROXIMATE SITEBOUNDARY

BK-2511 WELL AND IDENTIFICATION NUMBER

GENERALIZED STRATIGRAPHIC UNIT –Each unit represents an upward-finingsedimentary sequence capped by a siltstone unit

EXPLANATION

ABOVE UNIT 1

UNIT 1

UNIT 2

UNIT 3

UNIT 4

UNIT 5

UNIT 6

UNIT 7UNIT 8

N
16 Changes in Groundwater Flow and Volatile Organic Compound Concentrations, Fischer and Porter Superfund Site

the altitude of the top of the well casing, the well will flow. 

Boreholes that connect several water-producing zones may 

act as conduits for the transport of contaminants (Sloto and 

others, 1996).

Sloto and others (1995) divided the groundwater flow 

system into shallow, intermediate, and deep zones, which 

slightly overlap. The shallow zone is considered to be from 

land surface to less than about 100 ft below land surface, 

the intermediate-depth zone is considered to be about 100 to 

210 ft below land surface, and the deep zone is considered to 

be greater than about 210 ft below land surface.

Changes in Groundwater Flow

Pumping wells influence the groundwater system at and 

in the vicinity of the Fischer and Porter Site. As pumping patterns changed, the pattern of groundwater flow also changed.

Effect of Pumping the Fischer and Porter 

Remediation Wells

The combined groundwater pumping rate of the Fischer 

and Porter remediation-well system is approximately 

75 gal/min. Well FP-1 pumps 47 gal/min, well FP-2 pumps 

10 gal/min, and well FP-7 pumps 18 gal/min (CH2M Hill, 

Inc., 1998). The wells are pumped continuously. A temporary 

3-day shutdown of the remediation wells in 1993 (Sloto and 

others, 1995) had little effect (less than 1 ft of recovery) on 

shallow groundwater levels (table 3). Recovery was as great 

as 6.9 ft in the deep monitor wells (fig. 9) and 4.3 ft in the 

intermediate-depth wells (fig. 10). Recovery of water levels in 

the deep monitor wells was related to direction and distance 

from the recovery wells. Recovery was greater in the downdip 

than the updip direction. The direction of greatest recovery in 

the intermediate-depth wells was about N. 23° W., which was 

slightly west of the direction of dip.

Table 3. Changes in water level caused by pumping of the Warminster Heights supply wells and the shutdown of the Fischer and 

Porter remediation wells, Fischer and Porter Superfund Site, Warminster Township, Bucks County, Pennsylvania. From Sloto and others 

(1995, p. 35).

[USGS, U.S. Geological Survey; e, estimated]

USGS

well-identification

number

Screened or open interval

(feet below land surface)

Daily change in water level 

caused by pumping of

public-supply wells

(feet)

Recovery of water levels caused 

by shutdown of the Fischer and 

Porter remediation wells

(feet)

BK-1731 47–65 0.1 0.2 e

BK-1793 23–40 .3 .5 e

BK-1795 23–31 0 .2 e1, .4 e2

BK-1796 78–146 .5 2.8

BK-2511 300–325 .7 6.9

BK-2512 237–257 5.3 2.2

BK-2513 255–275 2.3 3.1

BK-2514 225–250 2.8 .8

BK-2515 285–305 .9 6.3

BK-2521 190–210 3.6 4.3

BK-2522 132–157 2.0 .1 e

BK-2523 23.5–43.5 1.7 .1 e

BK-2524 115–135 5.3 1.1

BK-2525 31–51 0 .0

BK-2526 50–70 0 .9 e2, 0 e3

BK-2527 157–187 2.6 3.3

BK-2528 25–45 .1 .4 e

1

Estimated for the December 13–15, 1993, shutdown.

2

Estimated for the May 16–19, 1994, shutdown.

3

Estimated for the April 27–29, 1994, shutdown.
Changes in Groundwater Flow 17

Figure 9. Recovery of water levels in deep wells caused by the 1993–94 shutdowns of the remediation wells, Fischer and Porter 

Superfund Site, Warminster Township, Bucks County, Pennsylvania. 

FP-1

BK-371

FP-2

BK-370

FP-7

BK-1324

BK-2514

BK-2515

BK-2511

BK-2512

BK-2513

75°5'40” 75°5'30” 75°5'20”

40°11'

40°11'10”

APPROXIMATE SITE

BOUNDARY

0 250 500 FEET

0 50 100 METERS

WATER-LEVEL RECOVERY CONTOUR – Shows recovery

of water level, in feet, caused by the shutdown of the Fischer 

and Porter remediation wells. Contour interval 1 foot. Dashed 

where inferred 

REMEDIATION WELL LOCATION – Symbol gives location of 

well. Number is well-identification number

FP-7

BK-1324

MONITOR WELL LOCATION – Symbol gives location 

of well. Top number is well-identification number. Bottom 

number is water-level recovery, in feet, caused by the 

shutdown of the Fischer and Porter remediation wells 

BK-2515

6.3

2.2

6.9

6.3

0.8

3.1

6

5

4

3

2

1

4

5

6

4 3

Base from U.S. Geological Survey digital data,1972, 1:2,000,000 Albers Equal-Area Conic Projection.

Standard parallels 29°30’N, central meridian 75°00’W.
18 Changes in Groundwater Flow and Volatile Organic Compound Concentrations, Fischer and Porter Superfund Site

Figure 10. Recovery of water levels in intermediate-depth wells caused by the 1993–94 shutdowns of the remediation wells, Fischer 

and Porter Superfund Site, Warminster Township, Bucks County, Pennsylvania. 

FP-1

BK-371

FP-2

BK-370

FP-7

BK-1324

75°5'40” 75°5'30” 75°5'20”

40°11'

40°11'10”

APPROXIMATE SITE

BOUNDARY

BK-2527

BK-2521

BK-2522

BK-2524

FP-12

BK-1796

0 250 500 FEET

0 50 100 METERS

WATER-LEVEL RECOVERY CONTOUR – Shows recovery

of water level, in feet, caused by the shutdown of the Fischer 

and Porter remediation wells. Contour interval 1 foot. Dashed 

where inferred 

REMEDIATION WELL LOCATION – Symbol gives location of

well. Number is well-identification number

FP-7

BK-1324

MONITOR WELL LOCATION – Symbol gives location of well. 

Top number is well-identification number. Bottom number is 

water-level recovery, in feet, caused by the shutdown of the

Fischer and Porter remediation wells 

BK-2521

4.3

2.2

4.3

3.3

1.1

2.8

3

4

2

4

3

3 4

4

3 2

4

1

1

Base from U.S. Geological Survey digital data,1972, 1:2,000,000 Albers Equal-Area Conic Projection.

Standard parallels 29°30’N, central meridian 75°00’W.
Changes in Groundwater Flow 19

Effect of Pumping Public-Supply Wells

The Warminster Heights supply wells (WH-1 and WH-2) 

stopped pumping around November 2004. When pumping, the 

wells exerted a considerable influence on water levels at the 

Fischer and Porter Site (table 3). The capacity of the pumps 

averaged 285 gal/min (CH2M Hill, Inc., 1998). Well WH-1 

penetrates stratigraphic units 1 through 5, and well WH-2 

penetrates stratigraphic units 4 through 8 (fig. 8). Pumping of 

the Warminster Heights wells had little effect on the shallow groundwater system (table 3); the water-level change 

was 1.7 ft in well BK-2523 and 0.3 ft or less in the other 

shallow wells. The pumping of well WH-2 affected only the 

southeastern part of the site and affected only well BK-2514 

(fig. 11). The pumping of well WH-1 caused a maximum daily 

fluctuation of 5.3 ft in the deep monitor wells (fig. 11) and the 

intermediate-depth wells (fig. 12). The pumping of well WH-1 

affected water levels most strongly along strike and downdip.

Horizontal Groundwater Gradients

Water-level data were collected by the USGS in 1993–94 

(Sloto and others, 1995) and in 2006–09 and by CH2M 

Hill, Inc. (1998) in 1996. During water-level-data collection 

in 1993–94 and 1996, the Warminster Heights wells were 

pumping. During water-level-data collection in 2006–09, the 

Warminster Heights wells were not pumping. Water levels 

measured at the Fischer and Porter Site for 2006–09 are presented in table 4.

Potentiometric-surface maps were published by Sloto and 

others (1995) for December 13, 1993, and May 3, 1994, with 

the Warminster Heights and Fischer and Porter remediation 

wells pumping. Potentiometric-surface maps were published 

by CH2M Hill, Inc. (1998) for March 18, 1996, with the 

Warminster Heights wells operating and the Fischer and Porter 

remediation wells not pumping, and for April 2, 1996, with the 

Warminster Heights wells and Fischer and Porter remediation 

wells FP-1 and FP-2 pumping. In 1993–94 (Sloto and others, 1995, p. 42) and 1996 (CH2M Hill, Inc., 1998, p. 3–18 

and 3–21), the direction of groundwater flow generally was 

towards the north.

For this study, water levels were measured in shallow 

wells on September 15, 2006 (fig. 13), January 16–20, 2007 

(fig. 14), and May 21–22, 2009 (fig. 15). The Fischer and 

Porter remediation wells were pumping on all three dates. On 

all three dates, the direction of groundwater flow was to the 

north-northwest. It is about the same direction as the previous (1993–94 and 1996) potentiometric-surface maps for the 

shallow zone. Horizontal gradients also were about the same. 

A groundwater divide to the north of the remediation wells 

is apparent on the shallow potentiometric-surface maps for 

September 2006, January 2007, and May 2009. This divide is 

caused by the pumping of the remediation wells. The shutdown of the Warminster Heights wells had little effect on the 

direction of groundwater flow in the shallow zone.

For this study, water levels were measured in intermediate-depth wells on September 15, 2006 (fig. 16), January 

16–20, 2007 (fig. 17), and May 21–22, 2009 (fig. 18). The 

potentiometric-surface maps for January 2007 and May 2009 

include water levels measured in the Warminster Heights 

wells. The Warminster Heights wells are open-hole wells, 

and the water level is a composite of the water levels in the 

water-bearing fractures penetrated by the well. The maps for 

2007 and 2009 (figs. 17 and 18) show the direction of groundwater flow is to the northwest. This differs from previously 

mapped groundwater-flow directions, which generally were to 

the north in 1993–94 (Sloto and others, 1995, p. 42) and 1996 

(CH2M Hill, Inc., 1998, p. 3–19 and 3–21) when Warminster 

Heights well WH-1 was pumping. The direction of groundwater flow in the intermediate-depth zone shifted from the 

north to the northwest after well WH-1 stopped pumping. The 

horizontal gradient on the northern side of the site was 0.023 

in January 2007 and May 2009. A horizontal hydraulic gradient could not be determined for September 2006. The horizontal hydraulic gradient on the northern side of the site was 

0.017 in March 1996 and 0.014 in April 1996. The horizontal 

hydraulic gradient on the northern side of the site was an order 

of magnitude less in December 1993 (0.005) and May 1994 

(0.003). The horizontal hydraulic gradient has become slightly 

steeper in the intermediate-depth zone since well WH-1 

stopped pumping.

For this study, water levels were measured in deep 

wells on September 15, 2006 (fig. 19), January 16–20, 2007 

(fig. 20), and May 21–22, 2009 (fig. 21). The map for January 

16–20, 2007, includes water levels measured in the Warminster Heights wells on February 22, 2007. The map for May 

21–22, 2009, includes water levels measured in the Warminster Heights wells and the new off-site monitor wells. On all 

three dates, the general direction of groundwater flow was 

to the northwest. A groundwater divide is apparent on the 

southeastern side of the site on the January 16–20, 2007, map 

(fig. 20). This divide approximately coincides with the topographic divide between tributaries to Pennypack Creek on the 

northwestern side of the divide and tributaries to Southampton 

Creek on the southeastern side of the divide.

The direction of groundwater flow in the deep zone was 

to the west and southwest in 1993–94 (Sloto and others, 1995, 

p. 42) and to the northeast toward Warminster Heights well 

WH-1 in 1996 (CH2M Hill, Inc., 1998, p. 3–19 and 3–21). 

After well WH-1 stopped pumping, the direction of groundwater flow changed to the northwest (fig. 21).

The horizontal hydraulic gradient in the deep zone is 

fairly flat on the north and northwestern sides of the site. On 

September 15, 2006, the difference in water-level altitude 

among the four deep monitor wells (BK-2511, BK-2512, 

BK-2513, and BK-2515) was only 0.91 ft, and the horizontal 

gradient was 0.002. On January 16–20, 2007, the difference 

in water-level altitude among the four deep monitor wells was 

1.61 ft, and the horizontal hydraulic gradient was 0.009. On 

May 21–22, 2009, the difference in water-level altitude among 

the four deep monitor wells was 4.97 ft, and the horizontal 
20 Changes in Groundwater Flow and Volatile Organic Compound Concentrations, Fischer and Porter Superfund Site

Figure 11. Change in water level in deep wells caused by the pumping of the Warminster Heights supply wells, Fischer and Porter 

Superfund Site, Warminster Township, Bucks County, Pennsylvania, 1993–94.

WH-1

BK-366

WH-2

BK-367

BK-2514

BK-2515

BK-2511

BK-2512

BK-2513

75°5'40” 75°5'30” 75°5'20”

40°11'

40°11'10”

APPROXIMATE SITE

BOUNDARY

0 250 500 FEET

0 50 100 METERS

WH-2

BK-367

WATER-LEVEL CONTOUR – Shows change in water level, in feet, 

caused by pumping of the Warminster Heights supply wells. 

Contour interval 1 foot. Dashed where inferred 

SUPPLY WELL LOCATION – Symbol gives location of 

well. Number is well-identification number

MONITOR WELL LOCATION – Symbol gives location of well. 

Top number is well-identification number. Bottom number is 

drawdown, in feet, caused by the pumping of the Warminster

Heights supply wells

BK-2514

2.8

5.3

0.7

0.9

2.8

2.3

3

2

5

1

4

2

1

2

3 4

5

2

1

1

4

Base from U.S. Geological Survey digital data,1972, 1:2,000,000 Albers Equal-Area Conic Projection. 

Standard parallels 29°30’N, central meridian 75°00’W. 
Changes in Groundwater Flow 21

Figure 12. Change in water level in intermediate-depth wells caused by the pumping of the Warminster heights supply wells, Fischer 

and Porter Superfund Site, Warminster Township, Bucks County, Pennsylvania.

WH-1

BK-366

WH-2

BK-367

75°5'40” 75°5'30” 75°5'20”

40°11'

40°11'10”

APPROXIMATE SITE

BOUNDARY

BK-2527

BK-2521

BK-2522

BK-2524

0 250 500 FEET

0 50 100 METERS

WH-2

BK-367

4 WATER-LEVEL CONTOUR – Shows change in water level, in feet, 

caused by pumping of the Warminster Heights supply wells. 

Contour interval 1 foot. Dashed where inferred 

SUPPLY WELL LOCATION – Symbol gives location of 

well. Number is well-identification number

MONITOR WELL LOCATION – Symbol gives location of well. 

Top number is well-identification number. Bottom number is 

drawdown, in feet, caused by pumping of the Warminster 

Heights supply wells

BK-2524

5.3

2.0

3.6

2.6

5.3

0.5 1

2

4

5

3

2

2

3

4

5

3

1

2

FP-12

BK-1796

Base from U.S. Geological Survey digital data,1972, 1:2,000,000 Albers Equal-Area Conic Projection. 

Standard parallels 29°30’N, central meridian 75°00’W. 
22 Changes in Groundwater Flow and Volatile Organic Compound Concentrations, Fischer and Porter Superfund Site

Table 4. Water levels measured at the Fischer and Porter Superfund Site, Warminster Township, Bucks County, Pennsylvania, 

2006–09.

[USGS, U.S. Geological Survey; >, greater than (well flowing); --. water level not measured]

USGS

well-identification

number

Water-level elevation (feet above NAVD 88)

September 15, 2006 January 16–20, 2007 May 21–22, 2009

BK-366 -- 1265.22 276.10

BK-367 -- 1258.99 276.99

BK-371 -- 228.35 234.92

BK-1030 -- 1257.45 >261

BK-1324 -- 203.70 261.02

BK-1731 271.78 273.27 272.75

BK-1793 275.96 277.88 277.63

BK-2511 266.74 270.98 267.55

BK-2512 265.83 269.37 267.61

BK-2513 266.44 270.94 272.52

BK-2514 271.27 274.95 272.26

BK-2515 266.72 270.08 267.68

BK-2521 263.62 267.57 269.54

BK-2522 261.11 259.33 270.08

BK-2523 256.88 259.61 265.90

BK-2524 269.22 273.59 277.24

BK-2525 272.21 273.20 274.45

BK-2526 279.82 286.47 284.37

BK-2527 259.45 263.30 277.53

BK-2528 273.94 275.42 275.04

BK-2810 267.11 271.17 272.63

BK-2811 273.16 274.61 274.26

BK-2827 272.74 277.02 265.05

BK-3042 -- -- 263.71

BK-3043 -- -- 256.35

BK-3045 -- -- 259.60

BK-3046 -- -- 209.96

1

Water level measured on February 22, 2007.
Changes in Groundwater Flow 23

Figure 13. Potentiometric surface measured in wells screened in the shallow zone at the Fischer and Porter Superfund Site, 

Warminster Township, Bucks County, Pennsylvania, September 15, 2006.

75°5'40” 75°5'30” 75°5'20”

40°11'

40°11'10”

APPROXIMATE SITE

BOUNDARY

BK-2526

BK-2523

FP-5

BK-1793

PH-4

BK-2827

PH-2

BK-2811

BK-2528

BK-1731

BK-2525

FP-1

FP-2 BK-371

BK-370

FP-7

BK-1324

0 250 500 FEET

0 50 100 METERS

271.78 275.96

256.88

272.21

279.82

273.94

273.16

270

275

LOCATION OF REMEDIATION WELL – Symbol

gives location of well. Number is 

well-identification number

LOCATION OF MONITOR WELL – Symbol

gives location of well. Bottom number is measured

water level in feet above North American Vertical 

Datum of 1988. Top number is well-identification

number 

BK-1731

271.78

FP-2

BK-370

WATER-LEVEL CONTOUR – Shows altitude of

the water table as defined by measured water

levels. Contour interval 5 feet. Dashed where 

inferred. Altitude in feet above North American

Vertical Datum of 1988 

260

270

275

272.74

270

265

260

270

265

260

Base from U.S. Geological Survey digital data,1972, 1:2,000,000 Albers Equal-Area Conic Projection.

Standard parallels 29°30’N, central meridian 75°00’W.
24 Changes in Groundwater Flow and Volatile Organic Compound Concentrations, Fischer and Porter Superfund Site

Figure 14. Potentiometric surface measured in wells screened in the shallow zone at the Fischer and Porter Superfund Site, 

Warminster Township, Bucks County, Pennsylvania, January 16–20, 2007.

75°5'40” 75°5'30” 75°5'20”

40°11'

40°11'10”

APPROXIMATE SITE

BOUNDARY

BK-2526

BK-2523

FP-5

BK-1793

PH-4

BK-2827

PH-2

BK-2811

BK-1030

BK-2528

BK-1731

BK-2525

FP-1

FP-2 BK-371

BK-370

FP-7

BK-1324

0 250 500 FEET

0 50 100 METERS

273.27 277.88

259.61

273.2

275.42

274.61

277.02

286.47

LOCATION OF REMEDIATION WELL – Symbol

gives location of well. Number is 

well-identification number 

LOCATION OF MONITOR WELL – Symbol

gives location of well. Bottom number is measured

water level in feet above North American Vertical 

Datum of 1988. Top number is well-identification 

number 

BK-1731

273.27

FP-2

BK-370

WATER-LEVEL CONTOUR – Shows altitude of

the water table as defined by measured water

levels. Contour interval 5 feet. Dashed where 

inferred. Altitude in feet above North American

Vertical Datum of 1988 

260

257.45

(2/22/07)

260

265

270

260

265

270

280

285

285

280

275

275

270

270

275

275

Base from U.S. Geological Survey digital data,1972, 1:2,000,000 Albers Equal-Area Conic Projection.

Standard parallels 29°30’N, central meridian 75°00’W.
Changes in Groundwater Flow 25

Figure 15. Potentiometric surface measured in wells screened in the shallow zone at the Fischer and Porter Superfund Site, 

Warminster Township, Bucks County, Pennsylvania, May 21–22, 2009.

75°5'40” 75°5'30” 75°5'20”

40°11'

40°11'10”

APPROXIMATE SITE

BOUNDARY

BK-2526

BK-2523

FP-5

BK-1793

PH-4

BK-2827

PH-2

BK-2811

BK-1030

BK-2528

BK-1731

BK-2525

FP-1

FP-2 BK-371

BK-370

FP-7

BK-1324

0 250 500 FEET

0 50 100 METERS

272.75 277.63

265.90

274.45

275.04

274.26

277.53

275

284.37

LOCATION OF EXTRACTION WELL – Symbol

gives location of well. Number is 

well-identification number 

LOCATION OF MONITOR WELL – Symbol

gives location of well. Bottom number is measured

water level in feet above North American Vertical 

Datum of 1988. Top number is well-identification

number 

BK-1731

272.75

FP-2

BK-370

WATER-LEVEL CONTOUR – Shows altitude of

the water table as defined by measured water

levels. Contour interval 5 feet. Dashed where 

inferred. Altitude in feet above North American 

Vertical Datum of 1988 

270

280

265

270

 <261

265

270

265

270

275

275

275

265

270

280

Base from U.S. Geological Survey digital data,1972, 1:2,000,000 Albers Equal-Area Conic Projection.

Standard parallels 29°30’N, central meridian 75°00’W.
26 Changes in Groundwater Flow and Volatile Organic Compound Concentrations, Fischer and Porter Superfund Site

Figure 16. Potentiometric surface measured in wells screened in the intermediate zone at the Fischer and Porter Superfund Site, 

Warminster Township, Bucks County, Pennsylvania, September 15, 2006.

263.62

261.11

269.22

259.45

267.11

0 250 500 FEET

0 50 100 METERS

FP-1

BK-371 FP-2

BK-370

FP-7

BK-1324

75°5'40” 75°5'30” 75°5'20”

40°11'

40°11'10”

APPROXIMATE SITE

BOUNDARY

PH-1

BK-2810

BK-2527

BK-2521

BK-2522

BK-2524

265

260

LOCATION OF REMEDIATION WELL – Symbol

gives location of well. Number is well-identification number 

FP-2

BK-370

WATER-LEVEL CONTOUR – Shows altitude of the potentiometric

surface as defined by measured water levels. Contour interval 5 feet. 

Altitude in feet above North American Vertical Datum of 1988 

260

LOCATION OF OPEN-HOLE MONITOR WELL – 

Symbol gives location of well. Bottom number is

measured water level in feet above North American Vertical 

Datum of 1988. Top number is well-identification number 

PH-1

BK-2810

267.11

BK-2521

263.62 LOCATION OF SCREENED 

MONITOR WELL – Symbol gives 

location of well. Bottom number is 

measured water level in feet above 

North American Vertical Datum of 1988. 

Top number is well-identification number 

260

265

ASSUMED CONE OF DEPRESSION AROUND REMEDIATION WELLS 

Base from U.S. Geological Survey digital data,1972, 1:2,000,000 Albers Equal-Area Conic Projection.

Standard parallels 29°30’N, central meridian 75°00’W.
Changes in Groundwater Flow 27

Figure 17. Potentiometric surface measured in wells screened in the intermediate zone at the Fischer and Porter Superfund Site, 

Warminster Township, Bucks County, Pennsylvania, January 16–20, 2007.

FP-1

BK-371

FP-2

BK-370

FP-7

BK-1324

WH-1

BK-366

WH-2

BK-367

75°5'40” 75°5'30” 75°5'20”

40°11'

40°11'10”

APPROXIMATE SITE

BOUNDARY

PH-1

BK-2810

BK-2527

BK-2521

BK-2522

BK-2524

267.57

259.33

263.3

265.2

258.99

260

260

265

270

265

260

265

(2/22/2007)

(2/22/2007)

265

270

0 250 500 FEET

0 50 100 METERS

WATER-LEVEL CONTOUR – Shows altitude of the potentiometric surface

as defined by measured water levels. Contour interval 5 feet. Dashed where

inferred. Altitude in feet above North American Vertical Datum of 1988 

260

LOCATION OF OPEN-HOLE WELL – Symbol gives 

location of well. Bottom number is measured water level in 

feet above North American Vertical Datum of 1988. Top 

number is well-identification number. Date is date of measurement 

PH-1

BK-2810

271.17

LOCATION OF REMEDIATION WELL – Symbol gives location of

well. Number is well-identification number 

FP-2

BK-370

BK-2521

267.57 LOCATION OF SCREENED MONITOR 

WELL – Symbol gives location of well. 

Bottom number is measured water level in feet 

above North American Vertical Datum of 1988. 

Top number is well-identification number 

260

265

273.59

271.17

270

270

ASSUMED CONE OF DEPRESSION AROUND REMEDIATION WELLS 

Base from U.S. Geological Survey digital data,1972, 1:2,000,000 Albers Equal-Area Conic Projection.

Standard parallels 29°30’N, central meridian 75°00’W.
28 Changes in Groundwater Flow and Volatile Organic Compound Concentrations, Fischer and Porter Superfund Site

Figure 18. Potentiometric surface measured in wells screened in the intermediate zone at the Fischer and Porter Superfund Site, 

Warminster Township, Bucks County, Pennsylvania, May 21–22, 2009.

FP-1

FP-2 BK-371

BK-370

FP-7

BK-1324

WH-1

BK-366

WH-2

BK-367

75°5'40” 75°5'30” 75°5'20”

40°11'

40°11'10”

APPROXIMATE SITE

BOUNDARY

PH-1

BK-2810

BK-2527

BK-2521

BK-2522

BK-2524

269.54

270.08

277.24

265.05

272.63

276.10

276.99

270

265

275

265

270

0 250 500 FEET

0 50 100 METERS

WATER-LEVEL CONTOUR – Shows altitude of the potentiometric surface

as defined by measured water levels. Contour interval 5 feet. Dashed where

inferred. Altitude in feet above North American Vertical Datum of 1988 

260

LOCATION OF OPEN-HOLE WELL – 

Symbol gives location of well. Bottom number is

measured water level in feet above North American Vertical 

Datum of 1988. Top number is well-identification number 

PH-1

BK-2810

271.17

LOCATION OF REMEDIATION WELL – Symbol gives location of 

well. Number is well-identification number 

FP-2

BK-370

BK-2521

269.54 LOCATION OF SCREENED MONITOR 

WELL – Symbol gives location of well.

Bottom number is measured water level

in feet above North American Vertical Datum of 

1988. Top number is well-identification number 

275

270

ASSUMED CONE OF DEPRESSION AROUND REMEDIATION WELLS 

Base from U.S. Geological Survey digital data,1972, 1:2,000,000 Albers Equal-Area Conic Projection.

Standard parallels 29°30’N, central meridian 75°00’W.
Changes in Groundwater Flow 29

Figure 19. Potentiometric surface measured in wells screened in the deep zone at the Fischer and Porter Superfund Site, 

Warminster Township, Bucks County, Pennsylvania, September 15, 2006.

FP-1

BK-371 FP-2

BK-370

FP-7

BK-1324

BK-2514

BK-2515

BK-2511

BK-2512

BK-2513

75°5'40” 75°5'30” 75°5'20”

40°11'

40°11'10”

APPROXIMATE SITE

BOUNDARY

266.74

265.83

266.44

271.27

266.72

266

268

266

270

266

266

266

0 250 500 FEET

0 50 100 METERS

BK-2511

266.74

WATER-LEVEL CONTOUR – Shows altitude of

the potentiometric surface as defined by measured

water levels. Contour interval 2 feet. Dashed where 

inferred. Altitude in feet above North American 

Vertical Datum of 1988 

268

FP-2

BK-370

LOCATION OF REMEDIATION WELL – Symbol

gives location of well. Number is well-identification

number

LOCATION OF SCREENED MONITOR 

WELL – Symbol gives location of well.

Bottom number is measured water level

in feet above North American Vertical Datum of 

1988. Top number is well-identification number 

268

270

ASSUMED CONE OF DEPRESSION AROUND REMEDIATION WELLS

Base from U.S. Geological Survey digital data,1972, 1:2,000,000 Albers Equal-Area Conic Projection.

Standard parallels 29°30’N, central meridian 75°00’W.
30 Changes in Groundwater Flow and Volatile Organic Compound Concentrations, Fischer and Porter Superfund Site

Figure 20. Potentiometric surface measured in wells screened in the deep zone at the Fischer and Porter Superfund Site, 

Warminster Township, Bucks County, Pennsylvania, January 16–20, 2007.

FP-1

BK-371

FP-2

BK-370

FP-7

BK-1324

WH-1

BK-366

WH-2

BK-367

BK-2514

BK-2515

BK-2511

BK-2512

BK-2513

75°5'40” 75°5'30” 75°5'20”

40°11'

40°11'10”

APPROXIMATE SITE

BOUNDARY

265.2

258.99

228.35

203.7

270.98

269.37

270.94

274.95

270.08

(2/22/2007)

(2/22/2007)

265

270

265

260

0 250 500 FEET

0 50 100 METERS

WATER-LEVEL CONTOUR – Shows altitude of the potentiometric surface

as defined by measured water levels. Contour interval 5 feet. Dashed 

where inferred. Altitude in feet above North American Vertical Datum of 1988 

270

BK-2511

270.98

LOCATION OF OPEN-HOLE WELL – 

Symbol gives location of well. Middle number 

is measured water level in feet above North 

American Vertical Datum of 1988. Lower number is date 

of measurement. Top number is well-identification 

number

LOCATION OF REMEDIATION WELL – Symbol gives

location of well. Bottom number is measured water level in

feet above North American Vertical Datum of 1988. Top number is

well-identification number 

FP-2

BK-370

203.70

LOCATION OF SCREENED 

MONITOR WELL – Symbol gives

location of well. Bottom number is

measured water level in feet above 

North American Vertical Datum of 1988. 

Top number is well-identification number 

WH-2

BK-367

258.99

(2/22/2007)

265

265

260

270

270

ASSUMED CONE OF DEPRESSION AROUND REMEDIATION WELLS 

270

270

270

Base from U.S. Geological Survey digital data,1972, 1:2,000,000 Albers Equal-Area Conic Projection.

Standard parallels 29°30’N, central meridian 75°00’W.
Changes in Groundwater Flow 31

Figure 21. Potentiometric surface measured in wells screened in the deep zone at the Fischer and Porter Superfund Site, 

Warminster Township, Bucks County, Pennsylvania, May 21–22, 2009.

WATER-LEVEL CONTOUR--Shows altitude of the potentiometric 

surface as defined by measured water levels. Contour interval 5 feet. 

Dashed where inferred. Altitude in feet above North American Vertical 

Datum of 1988 

270

LOCATION OF EXTRACTION WELL– Symbol gives location of well. 

Bottom number is measured water level in feet above North American 

Vertical Datum of 1988. Top number is well-identification number 

FP-2

BK-370

234.92

BK-2511

267.55

LOCATION OF SCREENED MONITOR WELL – 

Symbol gives location of well. Bottom number is

measured water level in feet above North 

American Vertical Datum of 1988. Top number is 

well-identification number 

LOCATION OF OPEN-HOLE MONITOR 

WELL – Symbol gives location of well. Bottom 

number is measured water level in feet above 

North American Vertical Datum of 1988. Top

number is well-identification number 

WH-2

BK-367

276.99

BK-2514

BK-2515

BK-2511

BK-2512

BK-2513

75°5'40” 75°5'20”

APPROXIMATE SITE

BOUNDARY

40°11'

40°11'10”

40°11'20”

BK-3046

BK-3045

BK-3043

BK-3042

JAC KSO NVIL LE R O AD

C O UNTY L INE R O AD

0 250 500 FEET

0 50 100 METERS

FP-1

BK-371

FP-2

BK-370

FP-7

BK-1324

WH-1

BK-366

WH-2

BK-367

276.1

276.99

234.92

261.02

267.55

267.61

272.52

272.26

267.68

270

270

275

275

209.96

256.35

263.71

259.6

260

260

265

265

255

255

EXPLANATION

ASSUMED CONE OF DEPRESSION AROUND REMEDIATION WELLS 

Base from U.S. Geological Survey digital data,1972, 1:2,000,000 Albers Equal-Area Conic Projection.

Standard parallels 29°30’N, central meridian 75°00’W.
32 Changes in Groundwater Flow and Volatile Organic Compound Concentrations, Fischer and Porter Superfund Site

gradient was 0.01. However, the difference in water-level 

altitude among three of the wells (BK-2511, BK-2512, and 

BK-2515) was only 0.13 ft.

The horizontal gradient on the northwestern side of the 

site was 0.010 in April 1996 (with the Warminster Heights 

wells and Fischer and Porter remediation wells FP-1 and FP-2 

pumping), 0.009 in March 1996 (with the Warminster Heights 

wells pumping and the Fischer and Porter remediation wells 

not pumping), and 0.004 in December 1993 and May 1994 

(with the Warminster Heights and the Fischer and Porter remediation wells pumping). In general, the horizontal hydraulic 

gradient on the northwestern side of the site has remained 

about the same.

Vertical Groundwater Gradients

Differences in water levels among the shallow, intermediate, and deep monitor wells at each monitor well cluster 

location indicate the presence of vertical head gradients. 

Measured heads (water-level elevations) were plotted on cross 

sections D-C, E-C, and D-E (locations of sections are shown 

on fig. 4). Along section D-C, the September 15, 2006, waterlevel measurements (fig. 22) showed a downward vertical 

hydraulic gradient from the shallow to the intermediate zone 

and an upward vertical hydraulic gradient from the deep to 

the intermediate zone (unit 3) at well clusters BK-1731-2521-

2511 and BK-2528-2527-2515. An upward vertical gradient 

in stratigraphic unit 3 indicates groundwater flow through this 

unit toward the remediation wells. At well cluster BK-2526-

2514, the vertical head gradient was downward. The January 

16–20, 2007, measurements showed an identical pattern. The 

measurements made on May 21–22, 2009 (fig. 23), show 

the same pattern except the vertical gradient was downward 

from stratigraphic unit 3 to stratigraphic unit 6 between wells 

BK-2521 and BK-2511.

Water levels were measured on December 13, 1993 

(fig. 24), when the Warminster Heights and Fischer and Porter 

remediation wells were pumping and on December 15, 1993 

(fig. 25), when the Warminster Heights wells were pumping and the Fischer and Porter remediation wells were not 

pumping (Sloto and others, 1996). When the Fisher and Porter 

remediation wells and Warminster Heights wells were pumping (fig. 24), the vertical head gradient was downward at all 

monitor well clusters. An upward vertical gradient in stratigraphic unit 3 indicates groundwater flows through this unit 

toward the remediation wells. On December 15, 1993, when 

the Warminster Heights wells were pumping and the Fisher 

and Porter remediation wells were not pumping (fig. 25), 

the vertical head gradient was downward at all monitor well 

clusters, and flow in stratigraphic unit 3 was away from the 

remediation wells.

Along section E-C, the September 15, 2006 (fig. 26), 

measurements showed an upward vertical hydraulic gradient 

at well cluster BK-2523-2522-2512 and a downward vertical hydraulic gradient at well cluster BK-2525-2524-2513. A 

groundwater divide (stagnation point) was present in the vicinity of well BK-2811, indicating that the pumping influence 

of the remediation wells did not reach well cluster BK-2525-

2524-2513. At well cluster BK-2526-2514, the vertical head 

gradient was downward.

Along section E-C, the January 16–20, 2007 (fig. 27), 

water-level measurements showed a downward vertical 

hydraulic gradient from the shallow to the intermediate zone 

and an upward vertical hydraulic gradient from the deep to the 

intermediate zone at well cluster BK-2523-2522-2512. At well 

cluster BK-2525-2524-2513, the vertical hydraulic gradient 

was upward from the intermediate zone to the shallow zone 

and downward from the intermediate zone to the deep zone. 

A groundwater divide (stagnation point) was present in the 

vicinity of well BK-2811, indicating the pumping influence 

of the remediation wells did not reach well cluster BK-2525-

2524-2513. At well cluster BK-2526-2514, the vertical head 

gradient was downward. This pattern is identical to the May 

21–22, 2009, measurements.

Water levels were measured on December 13, 1993 

(fig. 28), when the Warminster Heights and Fischer and Porter 

remediation wells were pumping (Sloto and others, 1996). 

The vertical hydraulic gradient was downward at well cluster 

BK-2523-2522-2512. At well cluster BK-2525-2524-2513, 

the vertical gradient was downward from the shallow zone to 

the intermediate zone, and the head was about the same in the 

deep and intermediate zones (the difference in head between 

the intermediate and deep zones was only 0.02 ft). A groundwater divide (stagnation point) was present between well 

BK-1324 and well cluster BK-2525-2524-2513, indicating the 

pumping influence of the remediation wells did not reach well 

cluster BK-2525-2524-2513. The vertical hydraulic gradient 

was downward from the shallow zone to the deep zone at well 

cluster BK-2526-2514.

Water levels were measured on December 15, 1993 

(fig. 29), when the Warminster Heights wells were pumping and the Fischer and Porter remediation wells were not 

pumping (Sloto and others, 1996). On December 15, 1993, 

the vertical gradient was downward from the shallow zone 

to the intermediate zone and upward from the deep zone to 

the intermediate zone at well cluster BK-2525-2524-2513. At 

well cluster BK-2523-2522-2512, the vertical head gradient 

was upward from the intermediate zone to the shallow zone 

and downward from the intermediate zone to the deep zone; 

however, the difference in head was only 0.32 ft between the 

shallow and intermediate zones and only 0.22 ft between the 

intermediate and deep zones. The vertical hydraulic gradient 

was downward from the shallow zone to the deep zone at well 

cluster BK-2526-2514.

Section D-E is approximately along strike at the northeastern boundary of the Fischer and Porter Site. Water levels 

were measured on December 13, 1993 (fig. 30), when the 

Warminster Heights and Fischer and Porter remediation 

wells were pumping and on December 15, 1993, when the 

Warminster Heights wells were pumping and the Fischer 

and Porter remediation wells were not pumping (Sloto and 
Changes in Groundwater Flow 33

Figure 22. Water-level altitude and direction of groundwater flow along section D-C, Fischer and Porter Superfund Site, Warminster 

Township, Bucks County, Pennsylvania, September 15, 2006. Wells BK-370 and BK-371 are projected to line of section. The location of 

section D-C is shown on figure 4.

BK-2515

BK-2521

UNIT 2

UNIT 5

UNIT 4

UNIT 3

UNIT 1

UNIT 6

BK-1731

BK-2511

BK-2526

UNIT 6

UNIT 5

UNIT 4

UNIT 3

UNIT 8

UNIT 7

FP-7 D C

-60

-40

-20

0

20

40

60

80

100

120

140

160

180

200

220

240

260

280

300

BK-2528

BK-2527

BK-1324

BK-2514

ELEVATION, IN FEET ABOVE NORTH AMERICAN VERTICAL DATUM OF 1988 

FP-1

BK-370 BK-371

FP-2

279.82

266.72

263.62

271.78

266.74

273.94

259.45

271.27

270 265 260 270

260

275

265

270

265

275

-160

-140

-120

-100

-80

OPEN-HOLE INTERVAL IN WELL

GENERALIZED DIRECTION OF GROUNDWATER FLOW

LINE OF EQUAL WATER-LEVEL ALTITUDE – 

Datum of 1988. Interval 5 feet. Dashed where

 

Altitude in feet above North American Vertical

inferred.

260

UNIT 1

BK-1731 WELL-IDENTIFICATION NUMBER

GENERALIZED STRATIGRAPHIC UNIT –

Each unit represents an upward-fining

sedimentary sequence capped by a 

siltstone unit

SCREENED INTERVAL IN WELL

ALTITUDE OF WATER LEVEL MEASURED 

IN WELL

271.78

0 200 400 FEET

HORIZONTAL SCALE

0 50 100 METERS

EXPLANATION

REMEDIATION WELLS

260

265
34 Changes in Groundwater Flow and Volatile Organic Compound Concentrations, Fischer and Porter Superfund Site

Figure 23. Water-level altitude and direction of groundwater flow along section D-C, Fischer and Porter Superfund Site, 

Warminster Township, Bucks County, Pennsylvania, May 21–22, 2009. Wells BK-370 and BK-371 are projected to line of section. The 

location of section D-C is shown on figure 4.

-160

-140

-120

-100

-80

BK-2515

BK-2521

UNIT 2

UNIT 5

UNIT 4

UNIT 3

UNIT 1

UNIT 6

BK-1731

BK-2511

BK-2526

UNIT 6

UNIT 5

UNIT 4

UNIT 3

UNIT 8

UNIT 7

FP-7

D C

-60

-40

-20

0

20

40

60

80

100

120

140

160

180

200

220

240

260

280

300

BK-2528

BK-2527

BK-1324

BK-2514

ELEVATION, IN FEET ABOVE NORTH AMERICAN VERTICAL DATUM OF 1988 

FP-1

BK-370 BK-371

FP-2

275.04

265.05

265

265

267.68

284.37

269.54

272.75

267.55

272.26

270 265 265 270 275

270 275

261.02

234.93

275

275

280

280

270

OPEN-HOLE INTERVAL IN WELL

GENERALIZED DIRECTION OF GROUNDWATER FLOW

LINE OF EQUAL WATER-LEVEL ALTITUDE –

Datum of 1988. Interval 5 feet. Dashed where

Altitude in feet above North American Vertical

inferred.

270

UNIT 1

BK-1731 WELL-IDENTIFICATION NUMBER

GENERALIZED STRATIGRAPHIC UNIT –

Each unit represents an upward-fining

sedimentary sequence capped by a 

siltstone unit

SCREENED INTERVAL IN WELL

ALTITUDE OF WATER LEVEL MEASURED 

IN WELL

0 200 400 FEET

HORIZONTAL SCALE

0 50 100 METERS

EXPLANATION

272.75

REMEDIATION WELLS

234.93 ALTITUDE OF PUMPING WATER LEVEL 

MEASURED IN REMEDIATION WELL

265
Changes in Groundwater Flow 35

Figure 24. Water-level altitude and direction of groundwater flow along section D-C, Fischer and Porter Superfund Site, Warminster 

Township, Bucks County, Pennsylvania, December 13, 1993. Water-level data from Sloto and others (1996). Wells BK-370 and BK-371 

are projected to line of section. The location of section D-C is shown on figure 4.

279.74

255.87

264.77

270.63

260.90

272.89

264.42

261.73

ELEVATION, IN FEET ABOVE NORTH AMERICAN VERTICAL DATUM OF 1988 

BK-2515

BK-2521

UNIT 2

UNIT 5

UNIT 4

UNIT 3

UNIT 1

UNIT 6

BK-1731

BK-2511

BK-2526

UNIT 6

UNIT 5

UNIT 4

UNIT 3

UNIT 8

UNIT 7

FP-7

-60

-40

-20

0

20

40

60

80

100

120

140

160

180

200

220

240

260

280

300

BK-2528

BK-2527

BK-1324

BK-2514

FP-1

BK-370 BK-371

FP-2

-160

-140

-120

-100

-80

260

265

260

275

270

275

260 270

265

260 265

270

270 265

D C

OPEN-HOLE INTERVAL IN WELL

LINE OF EQUAL WATER-LEVEL ALTITUDE –

Datum of 1988. Interval 5 feet. Dashed where

 

Altitude in feet above North American Vertical

inferred.

270

UNIT 1

BK-1731 WELL-IDENTIFICATION NUMBER

GENERALIZED STRATIGRAPHIC UNIT –

Each unit represents an upward-fining

sedimentary sequence capped by a 

siltstone unit

SCREENED INTERVAL IN WELL

ALTITUDE OF WATER LEVEL MEASURED 

IN WELL

0 200 400 FEET

HORIZONTAL SCALE

0 50 100 METERS

EXPLANATION

270.63

REMEDIATION WELLS

GENERALIZED DIRECTION OF GROUNDWATER FLOW
36 Changes in Groundwater Flow and Volatile Organic Compound Concentrations, Fischer and Porter Superfund Site

Figure 25. Water-level altitude and direction of groundwater flow along section D-C, Fischer and Porter Superfund Site, Warminster 

Township, Bucks County, Pennsylvania, December 15, 1993. Water-level data from Sloto and others (1996). Wells BK-370 and BK-371 

are projected to line of section. The location of section D-C is shown on figure 4.

279.18

262.28

267.07

270.58

262.14

272.80

269.20

261.81

265

265

270

275

270

275

265

270

ELEVATION, IN FEET ABOVE NORTH AMERICAN VERTICAL DATUM OF 1988 

BK-2515

BK-2521

UNIT 2

UNIT 5

UNIT 4

UNIT 3

UNIT 1

UNIT 6

BK-1731

BK-2511

BK-2526

UNIT 6

UNIT 5

UNIT 4

UNIT 3

UNIT 8

UNIT 7

FP-7

-60

-40

-20

0

20

40

60

80

100

120

140

160

180

200

220

240

260

280

300

BK-2528

BK-2527

BK-1324

BK-2514

FP-1

BK-370 BK-371

FP-2

-160

-140

-120

-100

-80

D C

OPEN-HOLE INTERVAL IN WELL

LINE OF EQUAL WATER-LEVEL ALTITUDE – 

Datum of 1988. Interval 5 feet. Dashed where

Altitude in feet above North American Vertical 

inferred.

270

UNIT 1

BK-1731 WELL-IDENTIFICATION NUMBER

GENERALIZED STRATIGRAPHIC UNIT –

Each unit represents an upward-fining

sedimentary sequence capped by a 

siltstone unit

SCREENED INTERVAL IN WELL

ALTITUDE OF WATER LEVEL MEASURED 

IN WELL

0 200 400 FEET

HORIZONTAL SCALE

0 50 100 METERS

EXPLANATION

270.58

REMEDIATION WELLS

GENERALIZED DIRECTION OF GROUNDWATER FLOW
Changes in Groundwater Flow 37

Figure 26. Water-level altitude and direction of groundwater flow along section E-C, Fischer and Porter Superfund Site, Warminster 

Township, Bucks County, Pennsylvania, September 15, 2006. Well BK-371 is projected to line of section. The location of section E-C is 

shown on figure 4.

E C

ELEVATION, IN FEET ABOVE NORTH AMERICAN VERTICAL DATUM OF 1988 -40

-20

0

20

40

60

80

100

120

140

160

180

200

220

240

260

280

300

BK-2522

BK-2525

UNIT 2

UNIT 5

UNIT 4

UNIT 3

UNIT 1

UNIT 6

UNIT 5

UNIT 4

UNIT 8

UNIT 7

BK-2512

BK-2523

BK-2524

BK-2513

FP-7

BK-1324

BK-2514

BK-2526 UNIT 3

PH-2 FP-1

BK-2811 BK-371

-160

-140

-120

-100

-80

-60

265

260 265 270 275

260

261.11

272.21

265.83

256.88

269.22

266.44

279.82

271.27

270

275

270

273.16

270

270

OPEN-HOLE INTERVAL IN WELL

LINE OF EQUAL WATER-LEVEL ALTITUDE – 

Datum of 1988. Interval 5 feet. Dashed where

Altitude in feet above North American Vertical 

inferred.

270

UNIT 1

BK-2523 WELL-IDENTIFICATION NUMBER

GENERALIZED STRATIGRAPHIC UNIT –

Each unit represents an upward-fining

sedimentary sequence capped by a 

siltstone unit

SCREENED INTERVAL IN WELL

ALTITUDE OF WATER LEVEL MEASURED 

IN WELL

0 200 400 FEET

HORIZONTAL SCALE

0 50 100 METERS

EXPLANATION

256.68

REMEDIATION WELLS

GENERALIZED DIRECTION OF GROUNDWATER FLOW
38 Changes in Groundwater Flow and Volatile Organic Compound Concentrations, Fischer and Porter Superfund Site

Figure 27. Water-level altitude and direction of groundwater flow along section E-C, Fischer and Porter Superfund Site, Warminster 

Township, Bucks County, Pennsylvania, January 16–20, 2007. Well BK-371 is projected to line of section. The location of section E-C is 

shown on figure 4.

E C

ELEVATION, IN FEET ABOVE NORTH AMERICAN VERTICAL DATUM OF 1988 -40

-20

0

20

40

60

80

100

120

140

160

180

200

220

240

260

280

300

BK-2522

BK-2525

UNIT 2

UNIT 5

UNIT 4

UNIT 3

UNIT 1

UNIT 6

UNIT 5

UNIT 4

UNIT 8

UNIT 7

BK-2512

BK-2523

BK-2524

BK-2513

FP-7

BK-1324

BK-2514

BK-2526 UNIT 3

PH-2 FP-1

BK-2811 BK-371

-160

-140

-120

-100

-80

-60

259.33

273.20

269.37

259.61

273.59

270.69

286.47

274.95

203.70

274.61

228.35

265

260 265 275 280 285

270

270 270

260

285

280

275

270

OPEN-HOLE INTERVAL IN WELL

GENERALIZED DIRECTION OF GROUNDWATER FLOW

LINE OF EQUAL WATER-LEVEL ALTITUDE – 

Datum of 1988. Interval 5 feet. Dashed where

 

Altitude in feet above North American Vertical 

inferred.

270

BK-2523 WELL-IDENTIFICATION NUMBER

UNIT 1 GENERALIZED STRATIGRAPHIC UNIT –

Each unit represents an upward-fining

sedimentary sequence capped by a 

siltstone unit

SCREENED INTERVAL IN WELL

ALTITUDE OF WATER LEVEL MEASURED 

IN WELL

0 200 400 FEET

HORIZONTAL SCALE

0 50 100 METERS

EXPLANATION

259.61

228.35 ALTITUDE OF PUMPING WATER LEVEL 

MEASURED IN REMEDIATION WELL

REMEDIATION WELLS

270
Changes in Groundwater Flow 39

Figure 28. Water-level altitude and direction of groundwater flow along section E-C, Fischer and Porter Superfund Site, Warminster 

Township, Bucks County, Pennsylvania, December 13, 1993. Water-level data from Sloto and others (1996). Well BK-371 is projected to 

line of section. The location of section E-C is shown on figure 4.

E C

ELEVATION, IN FEET ABOVE NORTH AMERICAN VERTICAL DATUM OF 1988 -40

-20

0

20

40

60

80

100

120

140

160

180

200

220

240

260

280

300

BK-2522

BK-2525

UNIT 2

UNIT 5

UNIT 4

UNIT 3

UNIT 1

UNIT 6

UNIT 5

UNIT 4

UNIT 8

UNIT 7

BK-2512

BK-2523

BK-2524

BK-2513

FP-7

BK-1324

BK-2514

BK-2526

UNIT 3

FP-1

BK-371

-160

-140

-120

-100

-80

-60

261.28

274.07

260.90

261.56

262.43

262.45

279.74

261.73

270

275

265

265

270

270

270 270 275

270

265

OPEN-HOLE INTERVAL IN WELL

LINE OF EQUAL WATER-LEVEL ALTITUDE – 

Datum of 1988. Intervcal 5 feet. Dashed where

Altitude in feet above North American Vertical 

inferred.

270

UNIT 1

BK-2523 WELL-IDENTIFICATION NUMBER

GENERALIZED STRATIGRAPHIC UNIT –

Each unit represents an upward-fining

sedimentary sequence capped by a 

siltstone unit

SCREENED INTERVAL IN WELL

ALTITUDE OF WATER LEVEL MEASURED 

IN WELL

EXPLANATION

261.56

0 200 400 FEET

HORIZONTAL SCALE

0 50 100 METERS

REMEDIATION WELLS

GENERALIZED DIRECTION OF GROUNDWATER FLOW
40 Changes in Groundwater Flow and Volatile Organic Compound Concentrations, Fischer and Porter Superfund Site

Figure 29. Water-level altitude and direction of groundwater flow along section E-C, Fischer and Porter Superfund Site, 

Warminster Township, Bucks County, Pennsylvania, December 15, 1993. Water-level data from Sloto and others (1996). Well BK-371 

is projected to line of section. The location of section E-C is shown on figure 4.

E C

ELEVATION, IN FEET ABOVE NORTH AMERICAN VERTICAL DATUM OF 1988 

-40

-20

0

20

40

60

80

100

120

140

160

180

200

220

240

260

280

300

BK-2522

BK-2525

UNIT 2

UNIT 5

UNIT 4

UNIT 3

UNIT 1

UNIT 6

UNIT 5

UNIT 4

UNIT 8

UNIT 7

BK-2512

BK-2523

BK-2524

BK-2513

FP-7

BK-1324

BK-2514

BK-2526

UNIT 3

FP-1

BK-371

-160

-140

-120

-100

-80

-60

262.36

273.75

262.14

262.04

265.19

265.97

279.18

261.81

265

265

275

270

270

265

275

265

OPEN-HOLE INTERVAL IN WELL

LINE OF EQUAL WATER-LEVEL ALTITUDE – 

Datum of 1988. Interval 5 feet. Dashed where

Altitude in feet above North American Vertical 

inferred.

270

UNIT 1

BK-2523 WELL-IDENTIFICATION NUMBER

GENERALIZED STRATIGRAPHIC UNIT –

Each unit represents an upward-fining

sedimentary sequence capped by a 

siltstone unit

SCREENED INTERVAL IN WELL

ALTITUDE OF WATER LEVEL MEASURED 

IN WELL

EXPLANATION

262.04

REMEDIATION WELLS

GENERALIZED DIRECTION OF GROUNDWATER FLOW
Changes in Groundwater Flow 41

Figure 30. Water-level altitude and direction of groundwater flow along section D-E, Fischer and Porter Superfund Site, 

Warminster Township, Bucks County, Pennsylvania, December 13, 1993. Water-level data from Sloto and others (1996). The 

location of section D-E is shown on figure 4.

BK-2522

BK-2512

BK-2523

BK-2521

UNIT 2

UNIT 5

UNIT 4

UNIT 3

UNIT 1

BK-1731

BK-2511

D E

-60

-40

-20

0

20

40

60

80

100

120

140

160

180

200

220

240

260

280

300

ELEVATION, IN FEET ABOVE NORTH AMERICAN VERTICAL DATUM OF 1988 

UNIT 6

270

270 266

264.77

270.63

260.90

261.28

260.90

261.56

262

268 264 262

266

268

264

GENERALIZED DIRECTION OF GROUNDWATER FLOW

LINE OF EQUAL WATER-LEVEL ALTITUDE – 

Datum of 1988. Interval 2 feet. Dashed where

Altitude in feet above North American Vertical 

inferred

270

UNIT 1

BK-1731 WELL-IDENTIFICATION NUMBER

GENERALIZED STRATIGRAPHIC UNIT –

Each unit represents an upward-fining

sedimentary sequence capped by a 

siltstone unit

SCREENED INTERVAL IN WELL

ALTITUDE OF WATER LEVEL MEASURED 

IN WELL

EXPLANATION

270.63

HORIZONTAL SCALE

0 100 200 FEET

0 25 50 METERS
42 Changes in Groundwater Flow and Volatile Organic Compound Concentrations, Fischer and Porter Superfund Site

others, 1996). For both dates, the groundwater-flow patterns 

were similar with groundwater flow from south to north and 

a downward vertical hydraulic gradient at both well clusters. 

Water levels measured on September 15, 2006, January 16–20, 

2007 (fig. 31), and May 21–22, 2009, also showed groundwater flow from south to north; however, the vertical hydraulic 

gradient between the deep zone and the intermediate zone was 

upward instead of downward in 2006 and 2007.

Changes in Volatile Organic Compound 

Concentration

Water samples for laboratory analysis for VOCs were collected from the remediation and monitor wells at the Fischer 

and Porter Site by CH2M Hill, Inc. (1998) in 1996, TetraTech 

EM, Inc. (2005) in 2005, and for this study in 2007 and 2009. 

Results of laboratory analyses are presented in appendix 1. 

Compounds of concern for water samples collected in 2007–

09 are summarized in table 5.

A light non-aqueous phase liquid (LNAPL) was found in 

remediation well FP-7 by Sloto and others (1995, p. 17) and in 

a nearby core hole. During water-level measurements, 6.4 ft of 

LNAPL was measured in well BK-2810 (PH-1) on September 

15, 2006, 3.7 ft was measured on January 19, 2007, and 3.4 ft 

was measured on May 22, 2009. The LNAPL in well FP-7 

was sampled by CH2M Hill, Inc. (1998) and was found to 

contain 520,000 μg/kg TCE and 65,000 μg/kg tetrachloroethylene (PCE). The LNAPL in well BK-2810 was sampled by 

TetraTech EM, Inc. (2005) and was found to contain an estimated concentration of 100,000 μg/kg of acetone; however, 

TCE and PCE were not reported as detected, and the detection 

limits were not given.

PCE and TCE can degrade into other organic compounds 

by anaerobic dehalogenation (fig. 32). The degradation of 

PCE produces TCE, and the degradation of TCE produces 

1-1,dichloroethylene (1,1-DCE), cis-1,2-dichloroethylene 

(cis-1,2-DCE), trans-1,2-dichloroethylene (trans-1,2-DCE), 

and vinyl chloride. An organic compound is reduced if a reaction leads to an increase in its hydrogen content or a decrease 

in its oxygen content; however, reduction reactions are more 

precisely defined in terms of electron transfers. An organic 

compound is reduced if it undergoes a net gain of electrons 

as the result of a chemical reaction (electron acceptor) and 

is oxidized if it undergoes a net loss of electrons (electron 

donor). Under aerobic conditions, oxygen commonly acts 

as the electron acceptor when present. When oxygen is not 

present (anaerobic or anoxic conditions), microorganisms 

can use organic compounds or inorganic anions as alternate 

electron acceptors. Generally, organic compounds present 

at a contaminated site represent potential electron donors to 

support microbial metabolism. However, halogenated compounds can act as electron acceptors and thus become reduced 

in the reductive dehalogenation process. Dehalogenation by 

reduction is the replacement of a halogen, such as chloride, on 

an organic molecule by a hydrogen atom (fig. 32) (Sims and 

others, 1991).

In 2007, TCE concentrations measured in water samples 

taken from the three remediation wells by the USGS ranged 

from less than 340 to 3,000 μg/L, and PCE concentrations 

ranged from less than 8.4 to 51 μg/L. TCE concentrations in 

water samples from the source-area remediation wells have 

decreased with time but remain highly variable. The discharge 

lines from wells BK-370 (FP-2) and BK-371 (FP-1) are 

plumbed together; therefore, samples represent a combined 

water sample from both wells. From August 1997 to June 

2001, the TCE and PCE concentrations in water samples 

from wells BK-370 and BK-371 showed an increasing trend, 

and from June 2001 to September 2008 showed a decreasing 

trend (figs. 33 and 34). TCE and PCE concentrations in water 

samples from well BK-1324 (FP-7) showed a decreasing trend 

(figs. 35 and 36).

Horizontal Distribution of Volatile Organic 

Compounds

In 2007, TCE concentrations measured in water samples 

from wells completed in the shallow zone ranged from less 

than 0.1 to 14,000 μg/L (fig. 37). The highest TCE concentration was in a water sample from well BK-2811 (PH-2), 

which is near the source area. The concentration of TCE in 

water samples from wells BK-2811 and BK-2827 (PH-4) for 

1996–2007 was variable. The TCE plume extends off-site to 

the north of the source area (fig. 37). The plume followed the 

hydraulic gradient in the shallow zone (fig. 14). Concentrations of TCE in water samples from well BK-2525 east of the 

source area decreased from 1996 to 2007. Concentrations of 

TCE in water samples from well BK-2528 west of the source 

area increased from 1996 to 2007.

In 2007, PCE concentrations ranged from less than 0.1 

to 340 μg/L (fig. 38). The highest PCE concentration was in 

a water sample from well BK-2811 (PH-2), which is near the 

source area; the PCE concentration in water samples from 

well BK-2811 for 1996–2007 was variable. The PCE plume 

extended off-site to the north of the source area (fig. 38). Concentrations of PCE in water samples from well BK-2827 east 

of the source area increased from 1996 to 2007.

In 2007, concentrations of degradation product 

cis-1,2-DCE ranged from less than 0.1 to 13,800 μg/L 

(fig. 39), and concentrations of degradation product 

trans-1,2-DCE ranged from less than 0.1 to 78 μg/L (fig. 39). 

Concentrations of cis-1,2-DCE were higher than concentrations of trans-1,2-DCE for all wells where the concentrations 

exceeded the detection limit. The highest concentrations of 

these compounds were in a water sample from well BK-2811 

(PH-2), which is near the source area. These compounds were 

formed by the breakdown of TCE, and the plume had the same 

configuration as the TCE plume.

VOC concentrations in water samples from off-site monitor wells BK-3042, BK-3043, BK-3045, and BK-3046 were 
Changes in Volatile Organic Compound Concentration 43

Figure 31. Water-level altitude and direction of groundwater flow along section D-E, Fischer and Porter Superfund Site, 

Warminster Township, Bucks County, Pennsylvania, January 16–20, 2007. The location of section D-E is shown on figure 4.

BK-2522

BK-2512

BK-2523

BK-2521

UNIT 2

UNIT 5

UNIT 4

UNIT 3

UNIT 1

BK-1731

BK-2511

D E

-60

-40

-20

0

20

40

60

80

100

120

140

160

180

200

220

240

260

280

300

ELEVATION, IN FEET ABOVE NORTH AMERICAN VERTICAL DATUM OF 1988 

UNIT 6

267.57

273.27

270.98

270

270

269.37

259.61

268

266 260

259.33

270

270

260

272 268

268

264 262

272

268

266

262

264

GENERALIZED DIRECTION OF GROUNDWATER FLOW

LINE OF EQUAL WATER-LEVEL ALTITUDE – 

Datum of 1988. Interval 2 feet. Dashed where 

Altitude in feet above North American Vertical 

inferred

270

UNIT 1

BK-1731 WELL-IDENTIFICATION NUMBER

GENERALIZED STRATIGRAPHIC UNIT –

Each unit represents an upward-fining

sedimentary sequence capped by a 

siltstone unit

SCREENED INTERVAL IN WELL

ALTITUDE OF WATER LEVEL MEASURED 

IN WELL

EXPLANATION

273.27

HORIZONTAL SCALE

0 100 200 FEET

0 25 50 METERS
44 Changes in Groundwater Flow and Volatile Organic Compound Concentrations, Fischer and Porter Superfund Site Table 5. Selected volatile organic compounds analyzed in groundwater, Fischer and Porter Superfund Site, Warminster Township, Bucks County, Pennsylvania, 2007–09.—Continued [Concentrations given in micrograms per liter. USGS, U.S. Geological Survey: E, estimated result less than reporting limit; <, less than] USGS well- identification number Sample date Site well- identification number Trichloro- ethylene Tetrachloro- ethylene 1,1,1-Trichloro- ethane 1,1-Dichloro- ethane 1,1-Dichloro- ethylene cis-1,2- Dichloro- ethylene trans-1,2- Dichloro- ethylene Vinyl chloride BK-366 3/37/2007 WH-1 6.2 0.6 0.3 <0.1 0.2 0.7 <0.1 <0.2 BK-367 2/22/2007 WH-2 .1 .2 < .1 < .1 < .1 < .1 < .1 < .2 BK-370 + BK-3711 1/19/2007 FP-1 + FP-2 3,000 51 <10 <10 12 24 <10 <20 BK-370 + BK-3711 2/18/2009 FP-1 + FP-2 280 12 .4 .7 1.9 54 .2 6.2 BK-1030 2/22/2007 WMA 7S 14 1.7 .1 .3 .2 7.4 < .1 < .2 BK-1324 1/19/2007 FP-7 340 8.4 7.5 6.3 6.3 320 2.6 40 BK-1324 2/18/2009 FP-7 240 10 3.8 4.2 5.4 170 1.5 17 BK-1731 1/16/2007 < .1 < .1 < .1 < .1 < .1 < .1 < .1 < .2 BK-1793 1/17/2007 FP-5 .2 E < .1 < .1 .8 < .1 .3 .1 .2 E BK-2511 1/16/2007 1.7 < .1 < .1 < .1 < .1 .3 < .1 < .2 BK-2512 1/18/2007 86 8.4 .3 .3 .5 12 .1 < .2 BK-2513 1/17/2007 2.3 .2 < .1 < .1 < .1 .7 < .1 < .2 BK-2514 1/16/2007 1.1 7.6 < .1 < .1 < .1 < .1 < .1 < .2 BK-2515 1/17/2007 28 .5 < .1 .5 1.1 E 13 .2 .3 E BK-2521 1/18/2007 100 5.3 .3 .6 1.1 E 13 .1 < .2 BK-2522 1/18/2007 500 28 <1 5.4 2.6 270 4.1 3.7 BK-2523 1/18/2007 20 2 < .1 .6 .1 E 7.7 < .1 < .2 BK-2524 1/17/2007 4.4 1.3 < .1 < .1 < .1 .1 < .1 < .2 BK-2525 1/17/2007 3.9 .7 < .1 2 < .1 1.2 < .1 < .2 BK-2526 1/16/2007 < .1 < .1 < .1 < .1 < .1 < .1 < .1 < .2 BK-2527 1/18/2007 240 12 .1 2.1 4.9 20 .2 .2 E BK-2528 1/18/2007 9.3 .2 < .1 .9 1 5.3 < .1 < .2 BK-2810 1/19/2007 PH-1 37 3.9 <1 <1 <1 9.2 <1 2.9 BK-2811 1/19/2007 PH-2 14,000 340 18 87 75 13,800 78 5,000
Changes in Volatile Organic Compound Concentration 45

Table 5. Selected volatile organic compounds analyzed in groundwater, Fischer and Porter Superfund Site, Warminster Township, Bucks County, Pennsylvania,2007–09.—Continued[Concentrations given in micrograms per liter. USGS, U.S. Geological Survey: E, estimated result less than reporting limit; <, less than]

USGS

wellidentification 

number

Sample date

Site

wellidentification 

number

Trichloroethylene Tetrachloro- ethylene 1,1,1-Trichloro- ethane 1,1-Dichloro- ethane 1,1-Dichloro- ethylene cis-1,2- Dichloro- ethylene trans-1,2- Dichloro- ethylene Vinyl chloride

BK-2827 1/17/2007 PH-4 7.4 23 .8 .7 .2 1.9 < .1 < .2

BK-3034 2/22/2007 83 7.4 0.3 0.8 0.8 27 0.2 <0.2BK-3042 2/9/2009 9.9 .1 < .1 .1 < .1 1.5 < .1 < .2BK-3043 2/9/2009 74 4.6 < .1 .5 .6 11 .2 < .2BK-3044 2/9/2009 < .1 < .1 < .1 < .1 < .1 < .1 < .1 < .1BK-3045 2/9/2009 71 3 .4 1 1.5 8.8 .2 < .2BK-3046 2/9/2009 < .1 .2 < .1 < .1 < .1 < .1 < .1 < .2MG-2149 8/15/2008 .64 .97 < .1 < .1 < .1 .22 < .1 < .2

1Combined sample. The wells are plumbed together. 
46 Changes in Groundwater Flow and Volatile Organic Compound Concentrations, Fischer and Porter Superfund Site

Figure 32. Typical reaction pathway for the anaerobic degradation of tetrachloroethylene and trichoroethylene by 

reductive dehalogenation.

C C

Cl

H H

Cl

C C

Cl

Cl H

Cl

C C

Cl

Cl Cl

Cl

TETRACHLOROETHYLENE

(PCE)

1,1-DICHLOROETHYLENE

(1,1-DCE)

VINYL CHLORIDE

(VC)

TRICHLOROETHYLENE

(TCE)

Cis-1,2-DICHLOROETHYLENE

(cis-1,2-DCE)

Trans-1,2-DICHLOROETHYLENE

(trans-1,2-DCE)

C C

Cl

Cl H

H

C C

H

Cl H

Cl

C C

H

H H

Cl

Figure 33. Concentration of trichloroethylene in monthly water samples from wells BK-370 and BK-371 (Fischer and Porter 

1 and 2), Fischer and Porter Superfund Site, Warminster Township, Bucks County, Pennsylvania, 1997–2008. Data provided by 

ABB, Inc.

0

1,000

2,000

3,000

4,000

5,000

6,000

1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008

TRICHLOROETHYLENE CONCENTRATION, IN MICROGRAMS PER LITER

TRICHLOROETHYLENE CONCENTRATION

TREND LINE 2001−08

TREND LINE 1997−2001
Changes in Volatile Organic Compound Concentration 47

Figure 34. Concentration of tetrachloroethylene in monthly water samples from wells BK-370 and BK-371 (Fischer and 

Porter 1 and 2), Fischer and Porter Superfund Site, Warminster Township, Bucks County, Pennsylvania, 1997-2008. Data 

provided by ABB, Inc.

SAMPLE ON 8/13/97

210 MICROGRAMS PER

LITER

0

25

50

75

100

125

1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008

TETRACHLOROETHYLENE CONCENTRATION, IN MICROGRAMS PER LITER

TETRACHLOROETHYLENE CONCENTRATION

TREND LINE 1997−2001

TREND LINE 2001−08

Figure 35. Concentration of trichloroethylene in monthly water samples from well BK-1324 (Fischer and Porter 7), Fischer 

and Porter Superfund Site, Warminster Township, Bucks County, Pennsylvania, 1997–2008. Data provided by ABB, Inc.

0

500

1,000

1,500

2,000

1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008

TRICHLOROETHYLENE CONCENTRATION, IN MICROGRAMS PER LITER

TRICHLOROETHYLENE CONCENTRATION

TREND LINE 1997−2008
48 Changes in Groundwater Flow and Volatile Organic Compound Concentrations, Fischer and Porter Superfund Site

Figure 36. Concentration of tetrachloroethylene in monthly water samples from well BK-1324 (Fischer and Porter 7), 

Fischer and Porter Superfund Site, Warminster Township, Bucks County, Pennsylvania, 1997–2008. Data provided by 

ABB, Inc.

0

20

40

60

80

1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008

TETRACHLOROETHYLENE CONCENTRATION, IN MICROGRAMS PER LITER

TETRACHLOROETHYLENE CONCENTRATION

TREND LINE 1997−2008
Changes in Volatile Organic Compound Concentration 49

Figure 37. Concentration of trichloroethylene in water samples from wells completed in the shallow zone, Fischer and Porter 

Superfund Site, Warminster Township, Bucks County, Pennsylvania, 1996–2007.

75°5'40” 75°5'30” 75°5'20”

40°11'

40°11'10”

APPROXIMATE SITE

BOUNDARY

BK-2526

BK-2523

FP-5

BK-1793

PH-4

BK-2827

PH-2

BK-2811

BK-1030

BK-2528

BK-1731

BK-2525

0 250 500 FEET

0 50 100 METERS

Base from U.S. Geological Survey digital data,1972, 1:2,000,000 Albers Equal-Area Conic Projection. 

Standard parallels 29°30’N, central meridian 75°00’W.

<0.1

0.2 E

20

3.9

9.3

14,000

7.4

1 <0.1

<0.5

<10

0.34 J

<10

<10

8 J

2 B

1,500

4 B

14

<0.5

5.2

27

2.7

22,000

14

BK-2523

WELL AND IDENTIFICATION NUMBER(S)

CONCENTRATION OF TRICHLOROETHYLENE

IN MICROGRAMS PER LITER – Number in green

is 1996 sample (from CH2M Hill, Inc. 1998); number 

in red is 2005 sample (from Tetra Tech EM, Inc., 2005);

number in blue is 2007 sample. <, less than; B, analyte

present in blank; E, estimated concentration; J, estimated 

concentration below minimum reporting level 

LINE OF EQUAL TRICHLOROETHYLENE CONCENTRATION – 

Data for 2007 used for contouring. Interval variable. Dashed 

where inferred 

10

14,000

1,500

22,000

FP-1

BK-371

FP-2

BK-370

3,000

3,000

1,900

7,600

BK-1324

FP-7

340

430

3,000

10

1

10

1

300

300

10

1
50 Changes in Groundwater Flow and Volatile Organic Compound Concentrations, Fischer and Porter Superfund Site

Figure 38. Concentration of tetrachloroethylene in water samples from wells completed in the shallow zone, Fischer and Porter 

Superfund Site, Warminster Township, Bucks County, Pennsylvania, 1996–2007.

75°5'40” 75°5'30” 75°5'20”

40°11'

40°11'10”

APPROXIMATE SITE

BOUNDARY

75°5'40” 75°5'30” 75°5'20”

40°11'10”

APPROXIMATE SITE

BOUNDARY

BK-2526

BK-2523

FP-5

BK-1793

PH-4

BK-2827

PH-2

BK-2811

BK-1030

BK-2528

BK-1731

BK-2525

0 250 500 FEET

0 50 100 METERS

Base from U.S. Geological Survey digital data,1972, 1:2,000,000 Albers Equal-Area Conic Projection.

Standard parallels 29°30’N, central meridian 75°00’W. 

<0.1

2

0.7

0.2

340

23

<0.1

<0.5

<10

<0.5

<10

<10

2 J

34 J

<10

13

0.43 J

1.9

<0.5

980 J

1.7

<0.1

<0.5

<10

LINE OF EQUAL TETRACHLOROETHYLENE CONCENTRATION – 

Data for 2007 used for contouring. Interval variable. Dashed where 

inferred 

10

BK-2523

WELL AND IDENTIFICATION NUMBER(S)

CONCENTRATION OF TETRACHLOROETHYLENE

IN MICROGRAMS PER LITER – Number in green

is 1996 sample (from CH2M Hill, Inc. 1998); number

in red is 2005 sample (from Tetra Tech EM, Inc., 2005);

number in blue is 2007 sample. <, less than; J,

estimated concentration below minimum reporting level 

340

34 J

980 J

FP-1

BK-371

BK-1324

FP-7

FP-2

BK-370

51

50

32

130

8.4

12J

51

300

1

1

1
Changes in Volatile Organic Compound Concentration 51

Figure 39. Concentration of cis-1,2-dichloroethylene and trans-1,2-dichloroethylene in water samples from wells completed in the 

shallow zone, Fischer and Porter Superfund Site, Warminster Township, Bucks County, Pennsylvania, 2007.

75°5'40” 75°5'30” 75°5'20”

40°11'

40°11'10”

APPROXIMATE SITE

BOUNDARY

BK-2526

BK-2523

FP-5

BK-1793

PH-4

BK-2827

PH-2

BK-2811

BK-1030

BK-2528

BK-1731

BK-2525

0 250 500 FEET

0 50 100 METERS

Base from U.S. Geological Survey digital data,1972, 1:2,000,000 Albers Equal-Area Conic Projection. 

Standard parallels 29°30’N, central meridian 75°00’W. 

<0.1

0.3

<0.1

<0.1

78

10

1

10

10,000

10 1

<0.1

1

<0.1

13,800

1.9

0.1

1.2

7.7

5.3

1

<0.1

<0.1

<0.1

7.4

<0.1

BK-2525

WELL AND IDENTIFICATION NUMBER(S)

CONCENTRATION IN MICROGRAMS PER 

LITER – Number in red is concentration of

cis-1,2-dichloroethylene; number in blue is

concentration of trans-1,2-dichoroethylene;

<, less than

10

0.3

0.1

LINE OF EQUAL CIS-1,2-DICHLOROETHYLENE 

CONCENTRATION – Interval variable.

Dashed where inferred

FP-1

BK-371 FP-2

BK-370

<10

24

BK-1324

FP-7

2.6

320

300
52 Changes in Groundwater Flow and Volatile Organic Compound Concentrations, Fischer and Porter Superfund Site

included with the on-site intermediate-depth wells because 

they are screened in the same lithostratigraphic units as the 

on-site intermediate-depth wells. For 2007–09, TCE concentrations measured in water samples from on-site intermediatedepth monitor wells ranged from less than 0.1 to 500 μg/L 

(fig. 40). The highest TCE concentration was in water samples 

from downgradient monitor well BK-2522. The TCE plume 

extended off-site to the north and northwest of the source area 

(fig. 40). The plume followed the hydraulic gradient in the 

intermediate zone (fig. 17). Concentrations of TCE in water 

samples from wells east of the source area (BK-2524 and 

BK-2810) decreased from 1996 to 2007. Concentrations of 

TCE in water samples north (BK-2522) and west (BK-2521 

and BK-2527) of the source area increased from 1996 to 2007.

For 2007–09, PCE concentrations measured in water 

samples from on-site intermediate-depth monitor wells ranged 

from 1.3 to 28 μg/L (fig. 41). The highest PCE concentration was in water samples from downgradient monitor well 

BK-2522. The PCE plume extended off-site to the north of the 

source area (fig. 41). The plume followed the hydraulic gradient in the intermediate zone (fig. 17). Concentrations of PCE 

in water samples from wells from 1996 to 2007 were variable.

For 2007–09, concentrations of degradation product 

cis-1,2-DCE measured in water samples from on-site intermediate-depth monitor wells ranged from less than 0.1 to 

270 μg/L (fig. 42), and concentrations of degradation product 

trans-1,2-DCE ranged from less than 0.1 to 4.1 μg/L (fig. 42). 

Concentrations of cis-1,2-DCE were higher than concentrations of trans-1,2-DCE where the concentrations exceeded the 

detection limit. The highest concentration of cis-1,2-DCE was 

in water samples from downgradient well BK-2522. These 

compounds were formed by the breakdown of TCE, and the 

plume had the same configuration as the TCE plume.

For 2007, the TCE concentrations measured in water 

samples from on-site deep monitor wells ranged from 1.1 to 

86 μg/L (fig. 43). The highest concentration of TCE was in 

water samples from downgradient monitor well BK-2512. The 

TCE plume extended off-site to the northwest of the source 

area (fig. 43) and generally followed the hydraulic gradient in 

the deep zone (fig. 21). Well BK-3034, which was flowing in 

2007, may have influenced groundwater flow and movement 

of TCE in the deep zone. In general, concentrations of TCE in 

water samples for deep monitor wells increased between 1996 

and 2005 and decreased between 2005 and 2007; concentrations were less in 2007 than in 1996.

For 2007, PCE concentrations measured in water samples 

from on-site deep monitor wells ranged from less than 0.1 to 

8.4 μg/L (fig. 44). The highest PCE concentration was in a 

water sample from downgradient monitor well BK-2512. The 

PCE plume extended off-site to the northwest of the source 

area (fig. 44) and generally followed the hydraulic gradient 

in the deep zone (fig. 20). Well BK-3034, which was flowing 

in 2007, may have influenced groundwater flow and movement of PCE in the deep zone. Concentrations of PCE in water 

samples for monitor wells outside the source area were less 

than 10 μg/L in 2007.

For 2007, concentrations of degradation product 

cis-1,2-DCE measured in water samples from on-site deep 

monitor wells ranged from less than 0.1 to 13 μg/L (fig. 45), 

and concentrations of degradation product trans-1,2-DCE 

ranged from less than 0.1 to 0.2 μg/L (fig. 45). Concentrations of cis-1,2-DCE were higher than concentrations of 

trans-1,2-DCE for all wells where the concentrations exceeded 

the detection limit. The highest concentrations of these compounds were in water samples from downgradient monitor 

well BK-2515. These compounds were formed by the breakdown of TCE, and the plume had the same configuration as the 

TCE plume.

In 2007, the vinyl chloride concentration measured in 

groundwater samples from all wells ranged from less than 0.2 

to 5,000 μg/L (fig. 46). The highest vinyl chloride concentration was in a water sample from monitor well BK-2811, which 

is near the source area. The presence of vinyl chloride indicates that reductive dehalogenation of TCE is occurring. Vinyl 

chloride was detected in water samples from 6 of the 24 wells 

sampled. Vinyl chloride was measured above the minimum 

detection limit (less than 0.2 μg/L) in water samples from one 

remediation well (FP-7), two shallow wells (FP-5 and PH-2), 

two intermediate-depth wells (PH-1 and BK-2522), and one 

deep well (BK-2515).

Vertical Distribution of Volatile Organic 

Compounds

The specific gravity of a substance is usually referenced 

to pure water, which is taken to be 1 gram per milliliter. TCE 

and PCE are heavier than water with a specific gravity of 1.46 

and 1.62, respectively; therefore, a spill or leak of sufficient 

magnitude is likely to move downward through the subsurface 

until lower-permeability features impede its progress. This 

commonly results in formation of a plume along a downward 

path in the aquifer.

TCE concentrations measured in water samples from 

wells along section A-C are shown on figure 47, and PCE 

concentrations are shown on figure 48. The highest TCE and 

PCE concentrations away from the source area were measured 

in water samples from wells BK-2521 and BK-2527, which 

are screened in stratigraphic unit 3. As of 2007, TCE and PCE 

appeared to be moving downdip through stratigraphic unit 3. 

The downdip extent of TCE and PCE migration extended 

approximately 550 ft off-site to the northwest and 750 ft 

off-site to the north. TCE concentrations in water samples 

from wells BK-2521 increased from 52 to 100 μg/L and from 

BK-2527 increased from 210 to 240 μg/L from 1996 to 2007.

TCE concentrations measured in water samples from 

wells along section B-C are shown on figure 49, and PCE 

concentrations are shown on figure 50. The highest concentrations of TCE away from the source area were in water samples 

from wells BK-2522 and BK-2512, which are screened in 

stratigraphic units 2, 3, and 4. The highest PCE concentration 

measured away from the source area was in water samples 
Changes in Volatile Organic Compound Concentration 53

Figure 40. Concentration of trichloroethylene in water samples from on-site wells completed in the intermediate zone and offsite wells completed in the deep zone, Fischer and Porter Superfund Site, Warminster Township, Bucks County, Pennsylvania, 

1996–2009.

75°5'40” 75°5'20”

40°11'

40°11'10”

APPROXIMATE SITE

BOUNDARY

40°11'20”

BK-3046 BK-3034

BK-3045

BK-3043

BK-3042

BK-3044

MG-2149 JAC KSO NVIL LE R O AD

C O UNTY L INE R O AD

Base from U.S. Geological Survey digital data,1972, 1:2,000,000 Albers Equal-Area Conic Projection. 

Standard parallels 29°30’N, central meridian 75°00’W. 

0 250 500 FEET

0 50 100 METERS

83

0.1

2J

6.2

43 74

0.6

<0.1

71

9.9

<0.6

FP-1

BK-371 FP-2

BK-370

FP-7

BK-1324

WH-1

BK-366

WH-2

BK-367

PH-1

BK-2810

BK-2527

BK-2521

BK-2522

BK-2524

100

4.4

240

37

340

100

10

3,000

3,000

400

400

130

720

230

210

490

390

430

3,000

3.7

55

84

52

1,900

7,600

500

100

100

400

400

10 50

1

1

1

10

50 50 10

100

50

FP-1

BK-371

WH-1

BK-366

BK-2511

WELL AND IDENTIFICATION 

NUMBER(S)

Monitor well 

Extraction well 

Open-hole well 

CONCENTRATION OF TRICHLOROETHYLENE

IN MICROGRAMS PER LITER – Number in green

is 1996 sample (from CH2M Hill, Inc. 1998); number

in red is 2005 sample (from Tetra Tech EM, Inc., 2005);

number in blue is 2007 sample; number in black is 2008–09

sample; <, less than; J, estimated concentration below minimum

reporting level 

10 LINE OF EQUAL TRICHLOROETHYLENE CONCENTRATION – 

Data for 2007–09 used for contouring. Interval variable. Dashed 

where inferred 

EXPLANATION

37

130

720

10
54 Changes in Groundwater Flow and Volatile Organic Compound Concentrations, Fischer and Porter Superfund Site

Figure 41. Concentration of tetrachloroethylene in water samples from on-site wells completed in the intermediate zone and 

off-site wells completed in the deep zone, Fischer and Porter Superfund Site, Warminster Township, Bucks County, Pennsylvania, 

1996–2009.

75°5'40” 75°5'20”

APPROXIMATE SITE

BOUNDARY

40°11'

40°11'10”

40°11'20”

BK-366

BK-367

BK-3046 BK-3034

BK-3045

BK-3043

BK-3042

BK-3044

MG-2149 JAC KSO NVIL LE R O AD

C O UNTY L INE R O AD

Base from U.S. Geological Survey digital data,1972, 1:2,000,000 Albers Equal-Area Conic Projection. 

Standard parallels 29°30’N, central meridian 75°00’W. 

0 250 500 FEET

0 50 100 METERS

4.6

0.97

0.2

3

0.1

<0.5

7.4

0.2

34

0.6

3J

1

1

FP-1

BK-371 FP-2

BK-370

FP-7

BK-1324

PH-1

BK-2810

BK-2527

BK-2521

BK-2522

BK-2524

5.3

1.3

12

2.9

10 

10

1

10

51

50

20

1.2 B

38 B

4.3 J

10

17 J

21 J

8.4

12 J

51

0.7

13

6 J

2 J

32

130

28

10

20

20

1

20

FP-1

BK-371

WH-1

BK-366

BK-2511

WELL AND IDENTIFICATION 

NUMBER(S)

Monitor well 

Extraction well 

Open-hole well 

CONCENTRATION OF TETRACHLOROETHYLENE

IN MICROGRAMS PER LITER – Number in green

is 1996 sample (from CH2M Hill, Inc. 1998); number 

in red is 2005 sample (from Tetra Tech EM, Inc., 2005);

number in blue is 2007 sample; number in black is 2008–09

sample; <, less than; B, analyte present in blank; J, estimated 

concentration below minimum reporting level 

51

32

130

10 LINE OF EQUAL TETRACHLOROETHYLENE CONCENTRATION – 

Data for 2007–09 used for contouring. Interval variable. Dashed 

where inferred 

EXPLANATION
Changes in Volatile Organic Compound Concentration 55

Figure 42. Concentration of cis-1,2-dichloroethylene and trans-1,2-dichloroethylene in water samples from on-site wells 

completed in the intermediate zone and off-site wells completed in the deep zone, Fischer and Porter Superfund Site, Warminster 

Township, Bucks County, Pennsylvania, 2007.

75°5'40” 75°5'20”

APPROXIMATE SITE

BOUNDARY

40°11'

40°11'10”

40°11'20”

BK-3046

BK-3045

BK-3043

BK-3042

BK-3044

MG-2149 JAC KSO NVIL LE R O AD

C O UNTY L INE R O AD

Base from U.S. Geological Survey digital data,1972, 1:2,000,000 Albers Equal-Area Conic Projection. 

Standard parallels 29°30’N, central meridian 75°00’W. 

0.22

<0.1

11

1.5

<0.5

1

<0.1

<0.1

0.2

<0.1

8.8

0.2

FP-1

BK-371

FP-2

BK-370

FP-7

BK-1324

WH-1

BK-366

WH-2

BK-367

BK-3034

PH-1

BK-2810

BK-2527

BK-2521

BK-2522

BK-2524

24

<10

<0.1

<0.1

2.6

320

0.2

27

0.7

<0.1

300

<0.1

9.2

<0.1

0.1

13

0.1

0.2

20

4.1

270

10

10

10

200

200

200

300

1

1

0 250 500 FEET

0 50 100 METERS

FP-1

BK-371

WH-1

BK-366

BK-2511

WELL AND IDENTIFICATION 

NUMBER(S)

Monitor well 

Extraction well 

Open-hole well 

CONCENTRATION IN MICROGRAMS PER LITER – 

Number in red is concentration of cis-1,2-dichloroethylene;

number in blue is concentration of trans-1,2-dichloroethylene;

<, less than 

2.6

320

10 LINE OF EQUAL CIS-1,2-DICHLOROETHYLENE 

CONCENTRATION – Interval variable. Dashed 

where inferred

EXPLANATION
56 Changes in Groundwater Flow and Volatile Organic Compound Concentrations, Fischer and Porter Superfund Site

Figure 43. Concentration of trichloroethylene in water samples from wells open to the deep zone, Fischer and Porter Superfund 

Site, Warminster Township, Bucks County, Pennsylvania, 1996–2009.

75°5'40” 75°5'20”

40°11'

40°11'10”

APPROXIMATE SITE

BOUNDARY

40°11'20”

BK-3046 BK-3034

BK-3045

BK-3043

BK-3042

BK-3044

MG-2149 JAC KSO NVIL LE R O AD

C O UNTY L INE R O AD

Base from U.S. Geological Survey digital data,1972, 1:2,000,000 Albers Equal-Area Conic Projection. 

Standard parallels 29°30’N, central meridian 75°00’W. 

0 250 500 FEET

0 50 100 METERS

82

0.1

2J

6.2

43 74

0.6

<0.1

71

9.9

<0.6

FP-1

BK-371

FP-2

BK-370

FP-7

BK-1324

WH-1

BK-366

WH-2

BK-367

340 10

3,000

3,000

430

3,000

1,900

7,600

100

100

10

50

1

1

1

10

50 10 50

100

 FP-1

BK-371

 WH-1

BK-366

BK-2511

WELL AND IDENTIFICATION 

NUMBER(S)

Monitor well 

Extraction well 

Open-hole well 

CONCENTRATION OF TRICHLOROETHYLENE

IN MICROGRAMS PER LITER – Number in green

is 1996 sample (from CH2M Hill, Inc. 1998); number 

in red is 2005 sample (from Tetra Tech EM, Inc., 2005);

number in blue is 2007 sample; number in black is 2008–09

sample; <, less than; B, analyte present in blank; J, estimated 

concentration below minimum reporting level 

10 LINE OF EQUAL TRICHLOROETHYLENE CONCENTRATION – 

Data for 2007–09 used for contouring. Interval variable. Dashed 

where inferred 

EXPLANATION

28

11

46

BK-2514

BK-2515

BK-2511

BK-2512

BK-2513

1.7

86

2.3

1.1

28

11

46

1B

82

190

1.4

3B

<0.5

8J

50

80

80

80

80
Changes in Volatile Organic Compound Concentration 57

Figure 44. Concentration of tetrachloroethylene in water samples from wells open to the deep zone, Fischer and Porter 

Superfund Site, Warminster Township, Bucks County, Pennsylvania, 1996–2009.

 FP-1

BK-371

 WH-1

BK-366

BK-2511

WELL AND IDENTIFICATION 

NUMBER(S)

Monitor well 

Extraction well 

Open-hole well 

CONCENTRATION OF TETRACHLOROETHYLENE

IN MICROGRAMS PER LITER – Number in green

is 1996 sample (from CH2M Hill, Inc. 1998); number 

in red is 2005 sample (from Tetra Tech EM, Inc., 2005);

number in blue is 2007 sample; number in black is 2008–09

sample; <, less than; J, estimated concentration below minimum

reporting level

51

32

130

10 LINE OF EQUAL TETRACHLOROETHYLENE CONCENTRATION – 

Data for 2007–09 used for contouring. Interval variable. Dashed 

where inferred 

EXPLANATION

75°5'40” 75°5'20”

APPROXIMATE SITE

BOUNDARY

40°11'

40°11'10”

40°11'20”

BK-3046 BK-3034

BK-3045

BK-3043

BK-3042

BK-3044

MG-2149 JAC KSO NVIL LE R O AD

C O UNTY L INE R O AD

Base from U.S. Geological Survey digital data,1972, 1:2,000,000 Albers Equal-Area Conic Projection.

Standard parallels 29°30’N, central meridian 75°00’W.

0 250 500 FEET

0 50 100 METERS

4.6

0.97

0.2

3

0.1

<0.5

7.4

0.2

34

0.6

3J

1

FP-1

BK-371 FP-2

BK-370

FP-7

BK-1324

5 

1

51

50

32

130

5

1

WH-1

BK-366

WH-2

BK-367

BK-2514

BK-2515

BK-2511

BK-2512

BK-2513

<0.1

8.4

0.2

7.6

0.5

0.1 J

1 J

<10

3 J

13

<0.5

<10

<0.5

<10

8.4

12 J

51

5

5 1
58 Changes in Groundwater Flow and Volatile Organic Compound Concentrations, Fischer and Porter Superfund Site

Figure 45. Concentration of cis-1,2-dichloroethylene and trans-1,2-dichloroethylene in water samples from wells open to the 

deep zone, Fischer and Porter Superfund Site, Warminster Township, Bucks County, Pennsylvania, 2007.

75°5'40” 75°5'20”

APPROXIMATE SITE

BOUNDARY

40°11'

40°11'10”

40°11'20”

BK-3046

BK-3045

BK-3043

BK-3042

BK-3044

MG-2149

Base from U.S. Geological Survey digital data,1972, 1:2,000,000 Albers Equal-Area Conic Projection. 

Standard parallels 29°30’N, central meridian 75°00’W. 

0.22

<0.1

11

1.5

<0.5

1

<0.1

<0.1

0.2

<0.1

8.8

0.2

FP-1

BK-371

FP-2

BK-370

FP-7

BK-1324

WH-1

BK-366

WH-2

BK-367

BK-3034

24

<10

<0.1

<0.1

2.6

320

0.2

27

0.7

<0.1

300

10

10

10

0 250 500 FEET

0 50 100 METERS

FP-1

BK-371

WH-1

BK-366

WELL AND IDENTIFICATION 

NUMBER(S)

Monitor well 

Extraction well 

Open-hole well 

CONCENTRATION IN MICROGRAMS PER LITER – 

Number in red is concentration of cis-1,2-dichloroethylene;

number in blue is concentration of trans-1,2-dichloroethylene; 

<, less than 

2.6

320

10 LINE OF EQUAL CIS-1,2-DICHLOROETHYLENE 

CONCENTRATION – Interval variable. Dashed 

where inferred

EXPLANATION

BK-2514

BK-2515

BK-2511

BK-2512

BK-2513

1

<0.1

<0.1

0.2

13

<0.1

0.3

<0.1

0.7

0.1

12

1

COUNTY LINE ROAD

JACKSONVILLE ROAD

BK-2511
Changes in Volatile Organic Compound Concentration 59

Figure 46. Concentration of vinyl chloride measured in water samples from wells at the Fischer and Porter Superfund Site, 

Warminster Township, Bucks County, Pennsylvania, 2007.

PH-2

BK-2811

FP-7

BK-1324

0 250 500 FEET

0 50 100 METERS

75°5'40” 75°5'30” 75°5'20”

40°11”

40°11'10”

APPROXIMATE SITE

BOUNDARY

Base from U.S. Geological Survey digital data,1972, 1:2,000,000 Albers Equal-Area Conic Projection. 

Standard parallels 29°30’N, central meridian 75°00’W. 

40

2.9

5,000

3.7

WELL WHERE VINYL CHLORIDE WAS NOT 

DETECTED – Detection limit is 0.2 microgram

per liter

WELL WHERE VINYL CHLORIDE WAS DETECTED –

Upper number(s) is well identification number(s) and lower

number is concentration of vinyl chloride in

micrograms per liter; E, estimated concentration 

5,000

PH-2

BK-2811

0.2E

FP-5

BK-1793

PH-1

BK-2810

0.3E

BK-2522

BK-2515
60 Changes in Groundwater Flow and Volatile Organic Compound Concentrations, Fischer and Porter Superfund Site

Figure 47. Concentration of trichloroethylene in water samples from wells along section A-C, Fischer and Porter Superfund Site, Warminster Township, Bucks County, Pennsylvania, 1996–2007. Wells BK-371 is projected to line of section. The lcoation of section A-C is shown on figure 4.

0 200 400 300 500 FEET 100

0 100 METERS 50

HORIZONTAL SCALE

BK-1324 FP-7

ELEVATION, IN FEET ABOVE NORTH AMERICAN VERTICAL DATUM OF 1988 -100 -20 -40 -60 -80

0

80604020

300280260240220200180160140120100

BK-2526

BK-2528

BK-1731

UNIT 1

UNIT 3UNIT 4UNIT 5UNIT 6UNIT 7UNIT 8

BK-3045

BK-3046

UNIT 2

UNIT 3UNIT 4

UNIT 5

UNIT 6

UNIT 1UNIT 2UNIT 3UNIT 4

A

C

BK-2521

BK-2511

BK-2527

BK-2515

BK-2514

BK-1731

UNIT 1

WELL-IDENTIFICATION NUMBER

GENERALIZED STRATIGRAPHIC UNIT –Each unit represents an upward-finingsedimentary sequence capped by a siltstone unit

SCREENED INTERVAL IN WELL

OPEN-HOLE INTERVAL IN WELL

CONCENTRATION OF TRICHLOROETHYLENEIN MICROGRAMS PER LITER – Number in greenis 1996 sample (from CH2M Hill, Inc. 1998); number in red is 2005 sample (from Tetra Tech EM, Inc., 2005);number in blue is 2007 sample; number in black is 2009sample. <, less than; B, analyte present in blank; J, estimated concentration below minimum reporting level 

LINE OF EQUAL TRICHLOROETHYLENE CONCENTRATION – Data from 2007–09 used for contouring. Interval variable. Dashed where inferred 

10

7,6001,9003,000

BK-371 FP-1

10

100

200

100

1

10

<0.5<0.1

4B

2.79.3 7,600 1,900

3,000

430

340

3,000

210

230

240

100

52

84

1.7

<0.5

8 J

4611

28

1B

1.1

<0.1

0.34J

<10

<10

1

10

10

10

100

1

300 200

71

<0.1

300

3,000

200

300

300

10

1

3,000
Changes in Volatile Organic Compound Concentration 61 Figure 48. Concentration of tetrachloroethylene in water samples from wells along section A-C, Fischer and Porter Superfund Site, Warminster Township, Bucks County, Pennsylvania, 1996–2007. Wells BK-371 is projected to line of section. The location of section A-C is shown on figure 4.

0 200 400 300 500 FEET 100

0 100 METERS 50

HORIZONTAL SCALE

ELEVATION, IN FEET ABOVE NORTH AMERICAN VERTICAL DATUM OF 1988 

BK-1324 FP-7

-100

-20-40-60-80

0

80604020

300280260240220200180160140120100

BK-2526 BK-2528

BK-1731

UNIT 1

UNIT 3UNIT 4UNIT 5UNIT 6UNIT 7UNIT 8

BK-3045

BK-3046

UNIT 2UNIT 3UNIT 4

UNIT 5

UNIT 6

UNIT 1UNIT 2UNIT 3UNIT 4

A

C

BK-2521

BK-2511

BK-2527

BK-2515

BK-2514

BK-371 FP-1

1

10

5

51

130

32 J

8.4

12 J

51

12

4.3 J

10

5.3

2.6 J

2 J

0.5

0.1 J

1 J

7.6

<10

<0.5<0.1

<10

<10

<0.5<0.1

1

1

5

5

1

1

50 10

<10

<0.5<0.1

0.2

<10

<0.5

5

10

1

3

0.2

10

BK-1731

UNIT 1

WELL-IDENTIFICATION NUMBER

GENERALIZED STRATIGRAPHIC UNIT –Each unit represents an upward-finingsedimentary sequence capped by a siltstone unit

SCREENED INTERVAL IN WELL

OPEN-HOLE INTERVAL IN WELL

51

32 J

130 CONCENTRATION OF TETRACHLOROETHYLENE

IN MICROGRAMS PER LITER – Number in greenis 1996 sample (from CH2M Hill, Inc. 1998); number in red is 2005 sample (from Tetra Tech EM, Inc., 2005);number in blue is 2007 sample; number in black is 2009sample. <, less than; J, estimated concentration below minimum reporting level 

LINE OF EQUAL TETRACHLOROETHYLENE CONCENTRATION – Data from 2007–09 used for contouring. Interval variable. Dashed where inferred 

10

1

50 10

10
62 Changes in Groundwater Flow and Volatile Organic Compound Concentrations, Fischer and Porter Superfund Site

Figure 49. Concentration of trichloroethylene in water samples from wells along section B-C, Fischer and Porter Superfund Site, Warminster Township, Bucks County, Pennsylvania, 1996–2007. Wells BK-371 and BK-2811 are projected to line of section. The location of section B-C is shown on figure 4.

ELEVATION, IN FEET ABOVE NORTH AMERICAN VERTICAL DATUM OF 1988 

BK-1324FP-7

UNIT 4

UNIT 5

UNIT 6

UNIT 3

UNIT 7

UNIT 8

BK-2522

BK-2512

BK-2523

BK-2526

BK-2514

-100

-20-40-60-80

0

80604020

300280260240220200180160140120100

BK-3043

UNIT 1

UNIT 5

UNIT 2

UNIT 3

UNIT 4

BK-3044

B

C

BK-2811PH-2

BK-371FP-1

20

1.1

<0.1

86

500

27

390490

<10

0.34J

190

82

1B

7,600

1,900

3,000

430

340

3,000 14,000

1,500

22,000

00 3

300

50

50

74

<0.5

<0.5

50

10

10

10

UNIT 1

BK-2512 WELL-IDENTIFICATION NUMBER

GENERALIZED STRATIGRAPHIC UNIT –Each unit represents an upward-finingsedimentary sequence capped by a siltstone unit

SCREENED INTERVAL IN WELLOPEN-HOLE INTERVAL IN WELL

CONCENTRATION OF TRICHLOROETHYLENEIN MICROGRAMS PER LITER – Number in greenis 1996 sample (from CH2M Hill, Inc. 1998); number in red is 2005 sample (from Tetra Tech EM, Inc., 2005);number in blue is 2007 sample; number in black is 2009sample. <, less than; B, analyte present in blank; J,estimated concentration below minimum reporting level 

LINE OF EQUAL TRICHLOROETHYLENE CONCENTRATION – Data from 2007–09 used for contouring. Interval variable. Dashed where inferred 

10

430344

3,000

0 200 400 300 500 FEET 100

0 100 METERS 50

HORIZONTAL SCALE

300

50

10

3,000

3,000

0 03

3,000

00 3

300

10

1

1

3,000
Changes in Volatile Organic Compound Concentration 63 Figure 50. Concentration of tetrachloroethylene in water samples from wells along section B-C, Fischer and Porter Superfund Site, Warminster Township, Bucks County, Pennsylvania, 1996–2007. Wells BK-371 and BK-2811 are projected to line of section. The location of section B-C is shown on figure 4.

ELEVATION, IN FEET ABOVE NORTH AMERICAN VERTICAL DATUM OF 1988 

LINE OF EQUAL TETRACHLOROETHYLENE CONCENTRATION – Data from 2007–09 used for contouring. Interval variable. Dashed where inferred 

BK-2512

UNIT 1

WELL-IDENTIFICATION NUMBER

GENERALIZED STRATIGRAPHIC UNIT –Each unit represents an upward-finingsedimentary sequence capped by a siltstone unit

SCREENED INTERVAL IN WELLOPEN-HOLE INTERVAL IN WELL

CONCENTRATION OF TETRACHLOROETHYLENEIN MICROGRAMS PER LITER – Number in greenis 1996 sample (from CH2M Hill, Inc. 1998); number in red is 2005 sample (from Tetra Tech EM, Inc., 2005);number in blue is 2007 sample; number in black is 2009sample. <, less than; J, estimated concentration below minimum reporting level 

BK-1324 FP-7

UNIT 3UNIT 4UNIT 5UNIT 6UNIT 7UNIT 8

BK-2522

BK-2512

BK-2523

BK-2526

BK-2514

-100

-20-40-60-80

0

80604020

300280260240220200180160140120100

BK-3043

UNIT 1UNIT 2UNIT 3UNIT 4UNIT 5

BK-3044

B

C

0 200 400 300 500 FEET 1000 100 METERS 50

HORIZONTAL SCALE

10

339

34 J

970

BK-2811 PH-2 BK-371 FP-1

2

7.3

<0.1

8.4

28

1.9

21 J17 J

<10

<0.5

13

3 J

<10

51

130

32 J

8.4

12 J

51 340

34 J

970

300 300

10

5

5

1

10

10

50

5

4.6

<0.5

<0.5

1

10

5

1

1

10 10 50

10

1
64 Changes in Groundwater Flow and Volatile Organic Compound Concentrations, Fischer and Porter Superfund Site

from well BK-2522, which is screened in stratigraphic units 2 

and 3. As of 2007, TCE and PCE appeared to be moving laterally and downward through stratigraphic units 2, 3, and 4.

Migration of Volatile Organic Compounds

The migration of VOCs from the Fischer and Porter Site 

is influenced by geologic and hydrologic controls. The hydrologic controls have changed with time.

Geologic controls include the strike and dip of bedding 

and permeability differences among beds. The bedding dips 

approximately 9° NW. (figs. 5 and 6). The direction of the 

bedding dip is approximately N. 25° W., which is perpendicular to strike (N. 65° E.). Rima and others (1962, p. 22) identified three systematic vertical joint sets. The most frequently 

occurring set was perpendicular to strike. The other two joint 

sets were parallel or nearly parallel to strike and at an angle of 

approximately 50° to strike. In the vicinity of the Fischer and 

Porter Site, these joint sets would be oriented at approximately 

N. 25° W., N. 65° E., and N. 15° E., respectively. Hydrologic 

controls include pumping and flowing wells at and in the 

vicinity of the Fischer and Porter Site.

The wells at and in the vicinity of the Fischer and Porter 

Site were initially sampled by SMC Martin, Inc. (1980) in 

1979–80. TCE concentrations were as high as 87,000 μg/L onsite and 350 μg/L off-site (fig. 51). At that time, wells BK-366 

(Warminster Heights 1), BK-367 (Warminster Heights 2), and 

MG-946 (Hatboro 16) were active public-supply wells, and 

wells BK-368 (La Rosa 2), BK-370 (Fischer and Porter 2), and 

BK-371 (Fischer and Porter 1) were active industrial-supply 

wells. Groundwater contaminated with VOCs flowed downdip 

and then northeast along strike toward well BK-366, downdip 

toward well BK-368, and downdip and then west along strike 

toward well MG-946.

Sometime between 1980 and 1990, wells BK-368 and 

MG-946 stopped pumping and were abandoned. In 1984, 

the Fischer and Porter supply wells BK-370 and BK-371, 

along with monitor well BK-1731, became remediation wells 

pumped continuously at a combined rate of 75 gal/min. The 

Warminster Heights wells continued to be pumped until 2004. 

Potentiometric-surface maps published by BCM, Inc. (1986, 

figs. 4–6) showed groundwater flow to the north toward 

Warminster Heights well WH-1.

In 1993, additional monitor wells were drilled at the 

Fischer and Porter Site by the USGS to provide detailed 

geologic, hydrologic, and water-quality data. Data from the 

intermediate-depth wells in 1993–94 (Sloto and others, 1995, 

p. 42) and 1996 (CH2M Hill, Inc., 1998, p. 3–19 and 3–21) 

indicated that the groundwater-flow direction generally was to 

the north when Warminster Heights well WH-1 was pumping. 

The direction of groundwater flow in the intermediate-depth 

zone was influenced by the pumping of well WH-1. Data from 

the deep wells indicated that the direction of groundwater flow 

was to the west and southwest in 1993–94 (Sloto and others, 

1995, p. 42) and to the northeast toward well WH-1 in 1996 

(CH2M Hill, Inc., 1998, p. 3–20 and 3–23).

The Warminster Heights wells stopped pumping in 2004. 

Potentiometric-surface maps constructed with data from both 

the intermediate and deep wells show the direction of groundwater flow shifted from the north to the northwest since well 

WH-1 stopped pumping.

Section E-C (fig. 4) is the closest section to the Warminster Heights wells. In 1993, groundwater gradients in the 

vicinity of wells BK-2514 and BK-2526 were towards the 

Fischer and Porter Site remediation wells and downward. 

In 2006–09, vertical groundwater gradients were toward the 

remediation wells. The downward gradient was still present, 

but it was less than when Warminster Heights well WH-2 

was pumping. On the west side of the Fisher and Porter Site 

near Warminster Heights well WH-1, the data generally were 

too variable to suggest a consistent change in the vertical 

gradient. Section D-E (fig. 4) is approximately along strike 

at the northwestern boundary of the Fischer and Porter Site. 

In 1993, groundwater flow was from south to north with a 

general downward vertical gradient. Water levels measured in 

2006–09 also showed groundwater flow from south to north; 

however, the vertical gradient between the deep and the intermediate zone was upward instead of downward. This reversal 

of the vertical hydraulic gradient likely was caused by cessation of pumping of well WH-1.

The movement of VOCs from the Fischer and Porter 

Site may have been influenced by well BK-3034. This unused 

300-ft deep open-hole well was in an overgrown, wooded area 

along Pennypack Creek. When this well was initially found 

about 1979, it was filled with rocks and debris and was not 

flowing. When the well was visited in 2007, it was still filled 

with rocks and debris, and it was flowing at an estimated 

20–30 gal/min. Cessation of local pumping likely caused the 

water level to rise above the top of the casing, and the well 

began flowing. It is not known how long the well flowed. 

When flowing, it acted as a withdrawal well. The well was 

abandoned (grouted shut) in 2008.

Stratigraphic units 2 and 3 crop out beneath the former 

Fischer and Porter plant (fig. 52). VOCs originating at the 

plant entered these stratigraphic units and moved downdip. 

The plume then spread out laterally along strike in response to 

pumping of public-supply wells. The long axis of the plume 

(fig. 40) is oriented about N. 18° W. in the direction of dip. 

This direction also coincides with the predominant joint set 

in the Stockton Formation (N. 25° W.) and it also is the direction of the hydraulic gradient in the intermediate and deep 

zones (fig. 21).

The leading edge of the plume spread laterally under 

hydraulic gradients created by the pumping of public-supply 

wells MG-946 and BK-366. In 1979–80, the leading edge of 

the plume was about 3,500 ft wide (fig. 51). With the cessation of pumping and the biodegradation of TCE and PCE, 

the size of the plume decreased. In 2007–09, the plume was 

approximately 2,000 ft long and 2,000 ft wide at the leading 

edge (fig. 40).
Changes in Volatile Organic Compound Concentration 65

Figure 51. Maximum concentration of trichloroethylene in groundwater samples, Fischer and Porter Superfund Site, Warminster 

Township, Bucks County, Pennsylvania, 1979–80. Data from SMC Martin, Inc. (1980).

Base from U.S. Geological Survey digital data,1972, 1:2,000,000 Albers Equal-Area Conic Projection. 

Standard parallels 29°30’N, central meridian 75°00’W. 

0 250 500 FEET

0 50 100 METERS

BK-1793

BK-370 BK-371

BK-1324

BK-366

BK-367

BK-1795

BK-372

75°5'40” 75°5'20”

40°11'

40°11'10”

APPROXIMATE SITE

BOUNDARY

40°11'20”

75°6'

MG-946

BK-368 JACKSONVILLE ROAD

COUNTY LINE ROAD

BK-371

WELL AND IDENTIFICATION NUMBER(S)

CONCENTRATION OF TRICHLOROETHYLENE

IN MICROGRAMS PER LITER – Number is

maximum concentration for 1979–80 from SMC

Martin, Inc. (1980) 

LINE OF EQUAL TRICHLOROETHYLENE 

CONCENTRATION – Interval variable. 

Dashed where inferred

300

140

Monitor well

Pumping well

30

10,000

300

87,000 14,000

96

45

2.9

350

30

30

30

300

2.6

140

15,000

540

300

BK-1795
66 Changes in Groundwater Flow and Volatile Organic Compound Concentrations, Fischer and Porter Superfund Site

Figure 52. Location of stratigraphic units 2 and 3 at the Fischer and Porter Superfund Site, Warminster Township, Bucks County, 

Pennsylvania.

FP-1

BK-371

FP-2

BK-370

FP-7

BK-1324

WH-1

BK-366

WH-2

BK-367

BK-2515

BK-2511

BK-2512

BK-2513

BK-2514

APPROXIMATE SITE

BOUNDARY

GENERALIZED STRATIGRAPHIC

UNIT – Each unit represents an 

upward-fining sedimentary 

sequence capped by a siltstone unit

UNIT 1

UNIT 8

UNIT 7

UNIT 6

UNIT 5

UNIT 4

UNIT 3

UNIT 2

EXPLANATION

N
Summary and Conclusions 67

Summary and Conclusions

The 38-acre Fischer and Porter Company Superfund 

Site is in Warminster Township, Bucks County, Pa. Historically, as part of the manufacturing process, trichloroethylene 

(TCE) degreasers were operated for parts cleaning. In 1979, 

the Bucks County Health Department detected TCE and 

other volatile organic compounds (VOCs) in water from the 

Fischer and Porter Site on-site supply wells and nearby publicsupply wells. The Fischer and Porter Site was designated as 

a Superfund Site and placed on the National Priorities List in 

September 1983. The U.S. Environmental Protection Agency 

(USEPA) requested the assistance of the U.S. Geological 

Survey (USGS) at the Fischer and Porter Site for the completion of the 5-year site review initiated in 2004. The purpose of 

this study was to describe changes in groundwater levels and 

VOC contaminant concentrations and migration caused by the 

shutdown of the Warminster Heights supply wells in 2004 and 

to delineate the off-site groundwater-contamination plume. As 

part of the current study, five additional off-site monitor wells 

were drilled and sampled. This study was done by the USGS 

in cooperation with the USEPA.

The Fischer and Porter Site and surrounding area are 

underlain by sedimentary rocks of the Stockton Formation of 

Late Triassic age. In the vicinity of the Fischer and Porter Site, 

the Stockton Formation strikes approximately N. 65° E. and 

dips approximately 9° NW. The rocks are chiefly interbedded 

arkosic sandstone and siltstone.

The rocks of the Stockton Formation form an aquifer 

system comprised of a series of gently dipping lithologic 

units with different hydraulic properties. The beds act as a 

series of alternating aquifers and confining or semiconfining 

units that form a leaky, multiaquifer system. Groundwater in 

the unweathered zone mainly moves through a network of 

interconnecting secondary openings—bedding-plane fractures 

and joints. Beds within the Stockton Formation are hydraulically connected by steeply dipping joints that cross each other 

at various angles. Groundwater generally is unconfined in the 

shallower part of the aquifer and confined or semiconfined in 

the deeper part of the aquifer. Boreholes may penetrate several 

major water-producing zones with different hydraulic properties and hydraulic heads. Where differences in head exist 

between water-producing zones, water in the borehole flows in 

the direction of decreasing head. Where the hydraulic head is 

greater than the altitude of the top of the well casing, the well 

will flow.

The three-dimensional lithostratigraphic model of the 

Fischer and Porter Site used in this report was developed by 

Sloto and others (1995) from lithostratigraphic interpretations and correlations based on the response to lithology of 

borehole geophysical logs collected in on-site boreholes. The 

lithostratigraphic model was extended off-site using borehole 

geophysical logs collected in five off-site boreholes drilled for 

this study. The lithostratigraphy was simplified by combining 

individual lithologic units into generalized sedimentary cycles. 

These cycles were labeled and are called stratigraphic units in 

this report.

The shutdown of the Warminster Heights wells had little 

effect on the direction of groundwater flow in the shallow 

zone (from land surface to approximately 100 ft below land 

surface). For this study, water levels were measured in shallow 

wells on September 15, 2006, January 16–20, 2007, and May 

21–22, 2009. For all three measurement sets, the direction of 

groundwater flow was to the north-northwest, which is about 

the same direction shown on previous (1993–96) potentiometric-surface maps for the shallow zone. Horizontal gradients 

also remained about the same.

For intermediate-depth wells (from approximately 100 to 

210 ft below land surface), the direction of groundwater flow 

was to the northwest in 2006–09. This differs from the previously mapped groundwater-flow direction, which generally 

was to the north in 1993–96 when Warminster Heights well 

WH-1 was pumping. The direction of groundwater flow in the 

intermediate-depth zone, which was influenced by the pumping of well WH-1, shifted from the north to the northwest and 

the horizontal hydraulic gradient became slightly steeper after 

well WH-1 stopped pumping.

For deep wells (greater than approximately 210 ft 

below land surface), the direction of groundwater flow was to 

the northwest in 2007–09. The direction of groundwater flow 

in the deep zone was to the west and southwest in 1993–94 

and to the northeast in 1996 toward well WH-1. After well 

WH-1 stopped pumping, the direction of groundwater flow 

shifted to the northwest. The horizontal hydraulic gradient 

in the deep zone has remained fairly flat on the northwestern 

side of the site.

Differences in water levels among the shallow, intermediate, and deep wells at each monitor-well cluster indicate the 

presence of vertical head gradients. Along section D-C, which 

is approximately parallel to the southwestern site boundary, 

when the Fisher and Porter remediation wells and Warminster Heights wells were pumping, the vertical head gradient 

was downward at all monitor-well clusters. Groundwater 

flow through stratigraphic unit 3 was toward the remediation 

wells. When the Warminster Heights wells were pumping and 

the Fisher and Porter remediation wells were not pumping, 

the vertical head gradient was downward at all monitor-well 

clusters, and flow in stratigraphic unit 3 was away from the 

remediation wells. Along section D-E, which is approximately 

along strike at the northwestern boundary of the Fischer and 

Porter Site, groundwater flow was from south to north with 

a downward vertical hydraulic gradient when the Warminster Heights wells were pumping. After the Warminster 

Heights wells stopped pumping, groundwater flow was still 

from south to north; however, the vertical hydraulic gradient between the deep and the intermediate zone was upward 

instead of downward.

In 2007, TCE concentrations measured by the USGS in 

water samples from the three remediation wells ranged from 

less than 340 to 3,000 micrograms per liter (μg/L), and PCE 

concentrations ranged from less than 8.4 to 51 μg/L. TCE 
68 Changes in Groundwater Flow and Volatile Organic Compound Concentrations, Fischer and Porter Superfund Site

concentrations have decreased with time but remained highly 

variable. From August 1997 to June 2001, the TCE and PCE 

concentrations in water samples from wells BK-370 and 

BK-371 showed an increasing trend, and from June 2001 to 

September 2008 showed a decreasing trend. TCE and PCE 

concentrations in water samples from well BK-1324 showed a 

decreasing trend over the same time period.

In 2007, TCE concentrations measured in water samples 

from wells completed in the shallow zone ranged from less 

than 0.1 to 14,000 μg/L, and PCE concentrations ranged from 

less than 0.1 to 340 μg/L. The highest TCE and PCE concentrations were in a water sample from well BK-2811, which is 

near the source area. The TCE and PCE plume extended offsite to the north of the source area. The migration of the plume 

was consistent with the hydraulic gradient in the shallow zone. 

Concentrations of TCE in water samples from well BK-2525 

east of the source area decreased from 8 to 3.9 μg/L from 1996 

to 2007. Concentrations of TCE in water samples from well 

BK-2528 west of the source area increased from 4 to 9.3 μg/L 

from 1996 to 2007. Concentrations of PCE in water samples 

from well BK-2827 east of the source area increased from less 

than 10 to 23 μg/L from 1996 to 2007.

VOC concentrations in water samples from off-site monitor wells BK-3042, BK-3043, BK-3045, and BK-3046 were 

included with the on-site intermediate-depth wells because 

they are screened in the same lithostratigraphic units as the 

on-site intermediate-depth wells. For 2007–09, TCE concentrations measured in water samples from on-site intermediatedepth monitor wells ranged from less than 0.1 to 500 μg/L, 

and PCE concentrations ranged from 1.3 to 28 μg/L. The 

highest TCE and PCE concentrations were in water samples 

from the downgradient monitor well BK-2522. The TCE and 

PCE plumes extended off-site to the north and northwest of 

the source area. The plumes followed the hydraulic gradient in the intermediate zone. Concentrations of TCE in water 

samples from wells BK-2524 and BK-2810 east of the source 

area decreased from 55 to 4.4 μg/L and 720 to 37 μg/L, 

respectively, from 1996 to 2007. Concentrations of TCE 

in water samples north (BK-2522) and west (BK-2521 and 

BK-2527) of the source area increased from 390 to 500 μg/L, 

52 to 100 μg/L, and 210 to 240 μg/L, respectively, from 1996 

to 2007. Concentrations of PCE in water samples from wells 

from 1996 to 2007 were variable.

In 2007, the TCE concentrations measured in water 

samples from on-site monitor wells completed in the deep 

zone ranged from 1.1 to 86 μg/L, and PCE concentrations 

ranged from 0.2 to 8.4 μg/L. TCE and PCE were detected in 

every deep well sampled. The highest concentrations of TCE 

and PCE were in water samples from downgradient monitor 

well BK-2512. The TCE and PCE plumes extended off-site 

to the northwest of the source area and generally followed the 

hydraulic gradient in the deep zone. Well BK-3034, which 

was flowing in 2007, may have influenced groundwater flow 

and movement of TCE and PCE in the deep zone. In general, 

concentrations of TCE in water samples for monitor wells 

outside the source area increased between 1996 and 2005 and 

decreased between 2005 and 2007; concentrations were less 

in 2007 than in 1996. Concentrations of PCE in water samples 

for monitor wells outside the source area were less than 

10 μg/L in 2007.

In 2007, the vinyl chloride concentration measured in 

groundwater samples from all wells ranged from less than 0.2 

to 5,000 μg/L. The presence of vinyl chloride indicated that 

reductive dehalogenation of TCE and PCE was occurring.

For wells along section A-C, which is approximately parallel to the southwestern site boundary, the highest TCE and 

PCE concentrations away from the source area were measured 

in water samples from wells BK-2521 and BK-2527, which 

are screened in stratigraphic unit 3. TCE and PCE appeared to 

be moving downdip though stratigraphic unit 3. The downdip 

extent of TCE and PCE migration extended approximately 

550 ft off-site to the northwest and 750 ft off-site to the north. 

TCE concentrations in water samples from wells BK-2521 and 

BK-2527 increased from 52 to 100 μg/L and 210 to 240 μg/L, 

respectively, from 1996 to 2007. For wells along section 

B-C, which is approximately parallel to the northeastern 

site boundary, the highest concentrations of TCE away from 

the source area were in water samples from wells BK-2522 

and BK-2524, which are screened in stratigraphic units 2 

and 3. The highest PCE concentration (28 μg/L) measured 

away from the source area was in a water sample from well 

BK-2522, which is screened in stratigraphic units 2 and 3. 

TCE and PCE appeared to be moving downward and laterally 

though stratigraphic units 2, 3, and 4.

The migration of VOCs from the Fischer and Porter Site 

source area is influenced by geologic and hydrologic controls. 

The hydrologic controls have changed with time. The wells at 

and in the vicinity of the Fischer and Porter Site were initially 

sampled in 1979–80. TCE concentrations were as high as 

87,000 μg/L on-site and 350 μg/L off-site. At that time, three 

public-supply wells (BK-366, BK-367, and MG-946) and 

three industrial-supply wells (BK-368, BK-370, and BK-371) 

were pumping. Groundwater contaminated with VOCs flowed 

downdip and then northeast along strike toward well BK-366, 

downdip toward well BK-368, and downdip and then west 

along strike toward well MG-946.

Sometime between 1980 and 1990, wells BK-368 and 

MG-946 stopped pumping and were abandoned. In 1984, 

the Fischer and Porter supply wells BK-370 and BK-371, 

along with monitor well BK-1731, became remediation wells 

pumped continuously at a combined rate of 75 gallons per 

minute. The Warminster Heights wells continued to pump 

until 2004. The direction of groundwater flow in the intermediate and deep zones was influenced by the pumping of well 

WH-1. Potentiometric-surface maps for 1986 showed groundwater flow to the north toward well WH-1. In 1993, additional 

monitor wells were drilled at the Fischer and Porter Site by the 

USGS. For the intermediate-depth wells, the groundwater-flow 

direction in 1993–96 generally was to the north when well 

WH-1 was pumping. For deep wells, the direction of groundwater flow was to the west and southwest in 1993–94 and to 

the northeast toward well WH-1 in 1996. After well WH-1 
References Cited 69

stopped pumping in 2004, the direction of groundwater flow 

in the intermediate zone shifted from the north to the northwest. In the deep zone, the direction of groundwater flow also 

shifted to the northwest.

The movement of VOCs from the Fischer and Porter 

Site may have been influenced by well BK-3034. In 2007, 

this unused 300-ft deep open-hole well was flowing at an 

estimated 20–30 gallons per minute. When flowing, the well 

acted as a withdrawal well. The well was abandoned (grouted 

closed) in 2008.

Stratigraphic units 2 and 3 crop out beneath the former 

Fischer and Porter plant. VOCs originating at the plant entered 

these stratigraphic units and moved downdip. The plume then 

spread out laterally along strike in response to pumping of 

public-supply wells. The long axis of the plume is oriented 

about N. 18° W. in the direction of dip. This direction also 

coincides with the predominant joint set in the Stockton 

Formation (N. 25° W.) and is the direction of the hydraulic 

gradient in the intermediate and deep zones. The leading edge 

of the plume spread laterally under hydraulic gradients created 

by the pumping of public-supply wells MG-946 and BK-366. 

In 1979–80, the leading edge of the plume was about 3,500 ft 

wide. With the cessation of pumping and the biodegradation 

of TCE, the size of the plume decreased. In 2007–09, the 

plume was approximately 2,000 ft long and 2,000 ft wide at 

the leading edge.

Acknowledgments

Permission from property owners to drill and test the 

additional off-site monitor wells is greatly appreciated. Access 

to wells for water-level measurements and samples was 

provided by John Engle of ABB, Inc.; Carol Gross; HavisShields, Inc.; and the Warminster Municipal Authority (Timothy Hagey and Philip Gardener). Assistance with groundwater 

sampling was provided by Leif Olson and Philip Bird of the 

USGS and Richard Sacks of Sigma Environmental Services, 

Inc. Borehole geophysical logging was done by Randall 

Conger of the USGS. Borehole television surveys were made 

by Philip Bird. Aquifer-isolation tests were conducted by Leif 

Olson, Randall Conger, and Philip Bird.

References Cited

BCM, Inc., 1986, Hydrogeological report for Fischer and 

Porter Company, Warminster, Pennsylvania: Plymouth 

Meeting, Pa., variously paginated.

CH2M Hill, Inc., 1998, Fischer and Porter Site remedial investigation report: Parsippany, N.J., variously paginated.

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

Water-Resources Investigations, book 2, chap. E-2, 149 p.

Rima, D.R., Meisler, Harold, and Longwill, Stanley, 1962, 

Geology and hydrology of the Stockton Formation in southeastern Pennsylvania: Pennsylvania Geologic Survey, 4th 

ser., Water Resources Report 14, 111 p.

Sims, J.L., Suflita, J.M., and Russell, H.H., 1991, Reductive 

dehalogenation of organic contaminants in soils and ground 

water: U.S. Environmental Protection Agency EPA/540/4-

90/054, 12 p.

Sloto, R.A., and Davis, D.K., 1983, Effect of urbanization on 

the water resources of Warminster Township, Bucks County, 

Pennsylvania: U.S. Geological Survey Water-Resources 

Investigations Report 82-4020, 72 p.

Sloto, R.A., Macchiaroli, Paola, and Conger, R.W., 1995, 

Geohydrology and vertical distribution of volatile organic 

compounds in ground water, Fischer and Porter Company 

Superfund Site, Warminster, Bucks County, Pennsylvania: 

U.S. Geological Survey Water-Resources Investigations 

Report 95-4220, 137 p.

Sloto, R.A., Macchiaroli, Paola, and Towle, M.T., 1992, Identification of a multiaquifer ground-water cross-contamination problem in the Stockton Formation by use of borehole 

geophysical methods, Hatboro, Pennsylvania: Proceedings, 

Symposium on the Application of Geophysics to Engineering and Environmental Problems, Oakbrook, Illinois, April 

26-29, 1992, Society of Engineering and Mineral Exploration Geophysicists, p. 21-35.

Sloto, R.A., Macchiaroli, Paola, and Towle, M.T., 1996, Geohydrology of the Stockton Formation and cross-contamination through open boreholes, Hatboro Borough and Warminster Township, Pennsylvania: U.S. Geological Survey 

Water-Resources Investigations Report 96-4047, 49 p.

SMC Martin, Inc., 1980, Hydrogeological study of Fischer 

and Porter company and vicinity, Warminster Township, 

Bucks County, Pennsylvania: King of Prussia, Pa., variously paginated.

Tetra Tech EM, Inc., 2005, Trip report for the Fischer and 

Porter Co. Site Warminster, Bucks County, Pennsylvania: 

Boothwyn, Pa., 17 p.
70 Changes in Groundwater Flow and Volatile Organic Compound Concentrations, Fischer and Porter Superfund Site
Appendix 1. Chemical Analyses 71

Table 1–1. Selected water-quality constituents measured in the field in water samples, Fischer and Porter Superfund Site, 

Warminster Township, Bucks County, Pennsylvania.

[mg/L, milligrams per liter; C, Celsius; μS/cm at 25°C, microsiemens per centimeter at 25 degrees Celsius]

USGS wellidentification 

number

Sample date

Site wellidentification 

number

pH

(standard units)

Dissolved oxygen

(mg/L)

Temperature

(°C)

Specific

conductance

(μS/cm at 25°C)

BK-366 3/37/2007 WH-1 7.4 4.0 14.3 639

BK-367 2/22/2007 WH-2 6.8 8.5 14.8 550

BK-1030 2/22/2007 WMA 7S 6.8 2.9 13.9 514

BK-1731 1/16/2007 6.5 .6 14.9 918

BK-1793 1/17/2007 FP-5 6.6 9.0 14.1 1,787

BK-2511 1/16/2007 8.1 3.1 13.3 266

BK-2512 1/18/2007 7.6 .6 12.4 600

BK-2513 1/17/2007 7.8 .6 12.2 371

BK-2514 1/16/2007 7.7 6.3 11.1 478

BK-2515 1/17/2007 8.8 .8 12.7 340

BK-2521 1/18/2007 7.7 1.5 13.7 638

BK-2522 1/18/2007 7.2 .2 12.8 800

BK-2523 1/18/2007 6.1 3.2 13.3 835

BK-2524 1/17/2007 6.9 7.5 12.2 637

BK-2525 1/17/2007 5.9 3.0 13.1 1,741

BK-2526 1/16/2007 6.2 7.0 12.3 478

BK-2527 1/18/2007 7.9 .3 13.8 599

BK-2528 1/18/2007 5.8 5.1 15.2 1,253

BK-2810 1/19/2007 PH-1 6.6 .5 14.5 1,005

BK-2811 1/19/2007 PH-2 6.6 .7 13.2 1,916

BK-2827 1/17/2007 PH-4 6.5 6.4 15.9 2,670

Appendix 1. Chemical Analyses
72 Changes in Groundwater Flow and Volatile Organic Compound Concentrations, Fischer and Porter Superfund Site Table 1–2. Volatile organic compounds analyzed in groundwater, Fischer and Porter Superfund Site, Warminster Township, Bucks County, Pennsylvania, 1979–2009.—Continued [Concentrationsw given in micrograms per liter; USGS, U.S. Geological Survey; --, not analyzed; <, less than; ND, not detected, detection limit not sepecified; B, compound reported in field blank; E, estimated concentration below minimum reporting level; D, diluted sample; J, estimated concentration below minimum reporting level. Source of data: 1, SMC Martin, Inc. (1980); 2, CH2M Hill, Inc. (1998); 3, Tetra Tech EM, Inc. (2005); 4, this study] USGS well- identification number Sample date Site well- identification number Source of data 1,1,1- Trichloro- ethane 1,1,2,2- Tetrachloro- ethane 1,1,2- Trichloro- trifluoro- ethane 1,1,2-Tri- chloro- ethane 1,1-Dichloro- ethane 1,1-Dichloro- ethylene 1,2-Dichloro- ethane BK-366 2/27/1980 WH-1 1 ND -- -- -- -- -- -- BK-366 10/79–3/80 WH-1 1 ND–5 -- -- -- -- -- -- BK-366 9/29/1993 WH-1 2 ND -- -- -- ND ND -- BK-366 3/37/2007 WH-1 4 0.3 -- 0.1 -- <0.1 0.2 <0.2 BK-367 10/8/1979 WH-2 1 -- -- -- -- -- -- -- BK-367 10/79–3/80 WH-2 1 ND–1.7 -- -- -- -- -- -- BK-367 9/29/1993 WH-2 2 ND -- -- -- ND ND -- BK-367 2/22/2007 WH-2 4 < .1 -- -- <0.1 < .1 < .1 < .2 BK-368 2/27/1980 La Rosa 2 1 15 -- -- -- -- -- -- BK-368 10/79–3/80 La Rosa 2 1 4.4–15 -- -- -- -- -- -- BK-370 11/8/1979 FP-2 1 7 -- -- -- -- -- -- BK-370 10/79–3/80 FP-2 1 ND–610 -- -- -- -- -- -- BK-371 11/6/1979 FP-1 1 -- -- -- -- -- -- -- BK-371 10/79–3/80 FP-1 1 ND–97 -- -- -- -- -- -- BK-372 11/8/1979 FP-3 1 38 -- -- -- -- -- -- BK-372 11/27/1979 FP-3 1 36 -- -- -- -- -- -- BK-370 + BK-371 9/29/1993 FP-1 + FP-2 2 -- -- -- -- ND 6 J -- BK-370 + BK-371 3/27/1996 FP-1 + FP-2 2 29 <10 -- 4 J <10 49 <10 BK-370 + BK-371 4/27/2005 FP-1 + FP-2 3 < .5 -- -- -- -- < .5 -- BK-370 + BK-371 1/19/2007 FP-1 + FP-2 4 <10 -- <10 <10 <10 12 <20 BK-370 + BK-371 2/18/2009 FP-1 + FP-2 4 .4 -- -- < .1 .7 1.9 < .2 BK-1030 2/22/2007 4 .1 -- -- < .1 .3 .2 < .2
Appendix 1. Chemical Analyses 73

Table 1–2. Volatile organic compounds analyzed in groundwater, Fischer and Porter Superfund Site, Warminster Township, Bucks County, Pennsylvania,1979–2009.—Continued[Concentrationsw given in micrograms per liter; USGS, U.S. Geological Survey; --, not analyzed; <, less than; ND, not detected, detection limit not sepecified; B, compound reported in fieldblank; E, estimated concentration below minimum reporting level; D, diluted sample; J, estimated concentration below minimum reporting level. Source of data: 1, SMC Martin, Inc. (1980);2, CH2M Hill, Inc. (1998); 3, Tetra Tech EM, Inc. (2005); 4, this study]

USGS

wellidentification 

number

Sample date

Site

wellidentification 

number

Source of 

data

1,1,1-

Trichloroethane

1,1,2,2-

Tetrachloroethane

1,1,2-

Trichlorotrifluoroethane 1,1,2-Tri- chloro- ethane 1,1-Dichloro- ethane 1,1-Dichloro- ethylene 1,2-Dichloro- ethane

BK-1324 2/27/1980 FP-7 1 3,300 -- -- -- -- -- --BK-1324 2/80–3/80 FP-7 1 1,300–4,600 -- -- -- -- -- --BK-1324 9/29/1993 FP-7 2 6 J -- -- -- ND 12 --BK-1324 3/1/1996 FP-7 2 45 -- -- -- -- 49 28BK-1324 4/27/2005 FP-7 3 15 J -- -- -- -- 18 J --BK-1324 1/19/2007 FP-7 4 7.5 -- <1 <1 6.3 6.3 <2BK-1324 2/18/2009 FP-7 3.8 -- -- < .1 4.2 5.4 < .2BK-1731 3/25/1996 2 <10 <10 -- <10 <10 <10 <10BK-1731 4/25/2005 3 < .5 -- -- -- -- < .5 --BK-1731 1/16/2007 4 < .1 -- < .1 < .1 < .1 < .1 < .2BK-1793 3/12/1980 FP-5 1 8 -- -- -- -- -- --BK-1793 2/80–3/80 FP-5 1 ND–8 -- -- -- -- -- --BK-1793 3/19/1996 FP-5 2 <10 <10 -- <10 2 J <10 <10BK-1793 4/25/2005 FP-5 3 < .5 -- -- -- -- < .5 --BK-1793 1/17/2007 FP-5 4 < .1 -- < .1 < .1 .8 < .1 < .2BK-1795 3/12/1980 FP-8 1 30 -- -- -- -- -- --BK-1795 2/80–3/80 FP-8 1 ND–30 -- -- -- -- -- --BK-1795 3/27/1996 FP-8 2 <10 <10 -- <10 <10 <10 <10BK-1796 3/27/1996 FP-12 2 <10 <10 -- <10 <10 2 J <10BK-2511 3/28/1996 2 <10 <10 -- <10 <10 <10 <10BK-2511 4/25/2005 3 < .5 -- -- -- -- < .5 --BK-2511 1/16/2007 4 < .1 -- < .1 < .1 < .1 < .1 < .2BK-2512 4/2/1996 2 1 J <10 -- <10 1 J 4 J <10BK-2512 4/26/2005 3 < .5 -- -- -- -- 1.2 J --BK-2512 1/18/2007 4 .3 -- < .1 < .1 .3 .5 < .2
74 Changes in Groundwater Flow and Volatile Organic Compound Concentrations, Fischer and Porter Superfund Site Table 1–2. Volatile organic compounds analyzed in groundwater, Fischer and Porter Superfund Site, Warminster Township, Bucks County, Pennsylvania, 1979–2009.—Continued [Concentrationsw given in micrograms per liter; USGS, U.S. Geological Survey; --, not analyzed; <, less than; ND, not detected, detection limit not sepecified; B, compound reported in field blank; E, estimated concentration below minimum reporting level; D, diluted sample; J, estimated concentration below minimum reporting level. Source of data: 1, SMC Martin, Inc. (1980); 2, CH2M Hill, Inc. (1998); 3, Tetra Tech EM, Inc. (2005); 4, this study] USGS well- identification number Sample date Site well- identification number Source of data 1,1,1- Trichloro- ethane 1,1,2,2- Tetrachloro- ethane 1,1,2- Trichloro- trifluoro- ethane 1,1,2-Tri- chloro- ethane 1,1-Dichloro- ethane 1,1-Dichloro- ethylene 1,2-Dichloro- ethane BK-2513 3/29/1996 2 <10 <10 -- <10 <10 <10 <10 BK-2513 4/26/2005 3 < .5 -- -- -- -- < .5 -- BK-2513 1/17/2007 4 < .1 -- <0.1 < .1 < .1 < .1 < .2 BK-2514 3/22/1996 2 <10 <10 -- <10 <10 <10 <10 BK-2514 1/16/2007 4 < .1 -- -- < .1 < .1 < .1 < .2 BK-2515 3/26/1996 2 <10 <10 -- <10 <10 2 J BK-2515 4/26/2005 3 < .5 -- -- -- -- .72 BK-2515 1/17/2007 4 < .1 -- < .1 < .1 .5 1.1 E BK-2521 3/25/1996 2 <10 <10 -- <10 <10 1 J <10 BK-2521 4/26/2005 3 < .5 -- -- -- -- 2.5 J -- BK-2521 1/18/2007 4 .3 -- < .1 < .1 .6 1.1 E < .2 BK-2522 4/1/1996 2 <10 <10 -- <10 7 J 7 J <10 BK-2522 4/26/2005 3 < .5 -- -- -- -- 8.8 J -- BK-2522 1/18/2007 4 <1 -- <1 <1 5.4 2.6 <2 BK-2523 4/26/2005 3 < .5 -- -- -- -- .39 J -- BK-2523 1/18/2007 4 < .1 -- < .1 < .1 .6 .1 E < .2 BK-2524 3/29/1996 2 <10 <10 -- <10 <10 1 J <10 BK-2524 4/26/2005 3 .12 J -- -- -- -- < .5 -- BK-2524 1/17/2007 4 < .1 -- < .1 < .1 < .1 < .1 < .2 BK-2525 3/29/1996 2 <10 <10 -- <10 5 J <10 <10 BK-2525 4/25/2005 3 < .5 -- -- -- -- < .5 -- BK-2525 1/17/2007 4 < .1 -- < .1 < .1 2 < .1 < .2 BK-2526 3/22/1996 2 <10 <10 -- <10 <10 <10 <10

BK-2526 4/25/2005 3 < .5 -- -- -- -- < .5 --BK-2526 1/16/2007 4 < .1 -- < .1 < .1 < .1 < .1 < .2
Appendix 1. Chemical Analyses 75

Table 1–2. Volatile organic compounds analyzed in groundwater, Fischer and Porter Superfund Site, Warminster Township, Bucks County, Pennsylvania,1979–2009.—Continued[Concentrationsw given in micrograms per liter; USGS, U.S. Geological Survey; --, not analyzed; <, less than; ND, not detected, detection limit not sepecified; B, compound reported in fieldblank; E, estimated concentration below minimum reporting level; D, diluted sample; J, estimated concentration below minimum reporting level. Source of data: 1, SMC Martin, Inc. (1980);2, CH2M Hill, Inc. (1998); 3, Tetra Tech EM, Inc. (2005); 4, this study]

USGS

wellidentification 

number

Sample date

Site

wellidentification 

number

Source of 

data

1,1,1-

Trichloroethane

1,1,2,2-

Tetrachloroethane

1,1,2-

Trichlorotrifluoroethane 1,1,2-Tri- chloro- ethane 1,1-Dichloro- ethane 1,1-Dichloro- ethylene 1,2-Dichloro- ethane

BK-2527 3/26/1996 2 <10 <10 -- <10 3 JD 7 J <10BK-2527 4/26/2005 3 < .5 -- -- -- -- 8.2 J --BK-2527 1/18/2007 4 .1 -- <0.1 < .1 2.1 4.9 .2BK-2528 3/26/1996 2 <10 <10 -- <10 <10 1 J <10BK-2528 4/26/2005 3 < .5 -- -- -- -- .27 J --BK-2528 1/18/2007 4 < .1 -- < .1 < .1 .9 1 < .2BK-2809 3/20/1996 PH-3 2 78 <10 -- 24 94 350 JD 10BK-2810 3/21/1996 PH-1 2 <50 <50 -- <50 <50 <50 <50BK-2810 5/18/2005 PH-1 3 < .5 -- -- -- -- < .5 --BK-2810 1/19/2007 PH-1 4 <1 -- <1 <1 <1 <1 <2BK-2811 3/19/1996 PH-2 2 140 <10 -- 21 100 220 JD <10BK-2811 4/26/2005 PH-2 3 < .5 -- -- -- -- 97 J --BK-2811 1/19/2007 PH-2 4 18 -- <10 <10 87 75 <20BK-2827 3/21/1996 PH-4 2 <10 <10 -- <10 <10 <10 < .2BK-2827 4/25/2005 PH-4 3 2.2 -- -- -- -- .77 JBK-2827 1/17/2007 PH-4 4 .8 -- < .1 < .1 .7 .2 < .2BK-3034 2/22/2007 4 .3 -- < .1 < .1 .8 .8 < .2BK-3042 2/9/2009 4 < .1 -- -- < .1 .1 < .1 < .2BK-3043 2/9/2009 4 < .1 -- -- < .1 .5 .6 < .2BK-3045 2/9/2009 4 .4 -- -- < .1 1 1.5 --

--

BK-3046 2/9/2009 4 < .1 -- -- < .1 < .1 < .1 < .2MG-946 11/1/1979 Hatboro-16 1 -- -- -- -- -- -- < .2MG-946 10/79–3/80 Hatboro-16 1 0.5–3.8 -- -- -- -- --MG-946 4/16/1992 Hatboro-16 4 .3 -- < .2 < .2 .2 < .2MG-2149 8/15/2008 4 < .1 -- -- < .1 < .1 < .1
76 Changes in Groundwater Flow and Volatile Organic Compound Concentrations, Fischer and Porter Superfund Site Table 1–2. Volatile organic compounds analyzed in groundwater, Fischer and Porter Site, Warminster Township, Bucks County, Pennsylvania, 1979–2009.—Continued [Concentrationsw given in micrograms per liter; USGS, U.S. Geological Survey; --, not analyzed; <, less than; ND, not detected, detection limit not sepecified; B, compound reported in field blank; E, estimated concentration below minimum reporting level; D, diluted sample; J, estimated concentration below minimum reporting level. Source of data: 1, SMC Martin, Inc. (1980); 2, CH2M Hill, Inc. (1998); 3, Tetra Tech EM, Inc. (2005); 4, this study] USGS well- identification number cis-1,2- Dichloro- ethylene trans-1,2- Dichloro- ethylene 1,2-Dichloro- ethylene (total) 1,2-Dichloro- propane trans-1,3- Dichloro propene 1,2-Dichloro- benzene 1,3-Dichloro- benzene 1,4-Dichloro- benzene BK-366 -- -- -- -- -- -- -- -- BK-366 -- -- -- -- -- -- -- -- BK-366 -- -- <8 -- -- -- -- -- BK-366 0.7 <0.1 .7 <0.1 -- <0.1 <0.1 <0.1 BK-367 -- -- -- -- -- -- -- -- BK-367 -- -- -- -- -- -- -- -- BK-367 -- -- ND -- -- -- -- -- BK-367 < .1 < .1 < .1 -- -- < .1 < .1 < .1 BK-368 -- -- -- -- -- -- -- -- BK-368 -- -- -- -- -- -- -- -- BK-370 -- -- -- -- -- -- -- -- BK-370 -- -- -- -- -- -- -- -- BK-371 -- -- -- -- -- -- -- -- BK-371 -- -- -- -- -- -- -- -- BK-372 -- -- -- -- -- -- -- -- BK-372 -- -- -- -- -- -- -- -- BK-370 + BK-371 -- -- 29 -- -- -- -- BK-370 + BK-371 -- -- 29 <10 <10 -- -- -- BK-370 + BK-371 40 J < .5 40 J -- -- -- -- -- BK-370 + BK-371 24 <10 -- <10 -- <10 <10 <10 BK-370 + BK-371 54 .2 -- .2 -- < .1 < .1 < .1 BK-1030 7.4 < .1 -- < .1 -- < .1 < .1 < .1
Appendix 1. Chemical Analyses 77

Table 1–2. Volatile organic compounds analyzed in groundwater, Fischer and Porter Site, Warminster Township, Bucks County, Pennsylvania, 1979–2009.—Continued[Concentrationsw given in micrograms per liter; USGS, U.S. Geological Survey; --, not analyzed; <, less than; ND, not detected, detection limit not sepecified; B, compound reported in fieldblank; E, estimated concentration below minimum reporting level; D, diluted sample; J, estimated concentration below minimum reporting level. Source of data: 1, SMC Martin, Inc. (1980);2, CH2M Hill, Inc. (1998); 3, Tetra Tech EM, Inc. (2005); 4, this study]

USGS

wellidentification 

number

cis-1,2-

Dichloroethylene

trans-1,2-

Dichloroethylene

1,2-Dichloroethylene

(total)

1,2-Dichloropropane trans-1,3- Dichloro propene 1,2-Dichloro- benzene 1,3-Dichloro- benzene 1,4-Dichloro- benzene

BK-1324 -- -- -- -- -- -- -- --BK-1324 -- -- -- -- -- -- -- --BK-1324 -- -- 140 -- -- -- -- --BK-1324 -- -- 1,800 2 J -- -- -- --BK-1324 400 <0.5 400 -- -- -- -- --BK-1324 320 2.6 <1 -- -- <1 <1 <1BK-1324 170 1.5 -- .4 -- < .1 < .1 < .1BK-1731 -- -- <10 <10 <10 -- -- --BK-1731 < .5 < .5 < .5 -- -- -- -- --BK-1731 < .1 < .1 < .1 < .1 -- <0.1 <0.1 <0.1BK-1793 -- -- -- -- -- -- -- --BK-1793 -- -- -- -- -- -- -- --BK-1793 -- -- 1 J <10 <10 -- -- --BK-1793 < .5 < .5 < .5 -- -- -- -- --BK-1793 .3 .1 .4 .3 E -- < .1 < .1 < .1BK-1795 -- -- -- -- -- -- -- --BK-1795 -- -- -- -- -- -- -- --BK-1795 -- -- <10 <10 <10 -- -- --BK-1796 -- -- 19 <10 <10 -- -- --BK-2511 -- -- <10 <10 <10 -- -- --BK-2511 < .5 < .5 < .5 -- -- -- -- --BK-2511 .3 < .1 .3 < .1 -- < .1 < .1 < .1BK-2512 -- -- 36 <10 <10 -- -- --BK-2512 11 < .5 11 -- -- -- -- --BK-2512 12 .1 12 .1 -- < .1 < .1 < .1
78 Changes in Groundwater Flow and Volatile Organic Compound Concentrations, Fischer and Porter Superfund Site Table 1–2. Volatile organic compounds analyzed in groundwater, Fischer and Porter Site, Warminster Township, Bucks County, Pennsylvania, 1979–2009.—Continued [Concentrationsw given in micrograms per liter; USGS, U.S. Geological Survey; --, not analyzed; <, less than; ND, not detected, detection limit not sepecified; B, compound reported in field blank; E, estimated concentration below minimum reporting level; D, diluted sample; J, estimated concentration below minimum reporting level. Source of data: 1, SMC Martin, Inc. (1980); 2, CH2M Hill, Inc. (1998); 3, Tetra Tech EM, Inc. (2005); 4, this study] USGS well- identification number cis-1,2- Dichloro- ethylene trans-1,2- Dichloro- ethylene 1,2-Dichloro- ethylene (total) 1,2-Dichloro- propane trans-1,3- Dichloro propene 1,2-Dichloro- benzene 1,3-Dichloro- benzene 1,4-Dichloro- benzene BK-2513 -- -- <10 <10 <10 -- -- -- BK-2513 0.63 <0.5 .63 -- -- -- -- -- BK-2513 .7 < .1 .7 < .1 -- <0.1 <0.1 <0.1 BK-2514 -- -- <10 <10 <10 -- -- -- BK-2514 < .1 < .1 < .1 < .1 -- < .1 < .1 < .1 BK-2515 -- -- 9 J <10 <10 -- -- -- BK-2515 8.7 .17 J 8.9 -- -- -- -- -- BK-2515 13 .2 13.1 < .1 -- < .1 < .1 < .1 BK-2521 -- -- 6 J <10 <10 -- -- -- BK-2521 15 <0.5 15 -- -- -- -- -- BK-2521 13 .1 13 .2 -- <0.1 <0.1 <0.1 BK-2522 -- -- 220 <10 <10 -- -- -- BK-2522 360 < .5 300 -- -- -- -- -- BK-2522 270 4.1 280 <1 -- <1 <1 <1 BK-2523 17 .40 J 17 -- -- -- -- -- BK-2523 7.7 < .1 7.7 < .1 -- < .1 < .1 < .1 BK-2524 -- -- 2 J <10 <10 -- -- -- BK-2524 .18 J < .5 .18 J -- -- -- -- -- BK-2524 .1 < .1 .1 < .1 -- < .1 < .1 < .1 BK-2525 -- -- 2 J <10 <10 -- -- -- BK-2525 1.0 < .5 1.0 -- -- -- -- -- BK-2525 1.2 < .1 1.2 < .1 -- < .1 < .1 < .1 BK-2526 -- -- <10 <10 <10 -- -- -- BK-2526 < .5 < .5 < .5 -- -- -- -- -- BK-2526 < .1 < .1 < .1 < .1 -- < .1 < .1 < .1
Appendix 1. Chemical Analyses 79

Table 1–2. Volatile organic compounds analyzed in groundwater, Fischer and Porter Site, Warminster Township, Bucks County, Pennsylvania, 1979–2009.—Continued[Concentrationsw given in micrograms per liter; USGS, U.S. Geological Survey; --, not analyzed; <, less than; ND, not detected, detection limit not sepecified; B, compound reported in fieldblank; E, estimated concentration below minimum reporting level; D, diluted sample; J, estimated concentration below minimum reporting level. Source of data: 1, SMC Martin, Inc. (1980);2, CH2M Hill, Inc. (1998); 3, Tetra Tech EM, Inc. (2005); 4, this study]

USGS

wellidentification 

number

cis-1,2-

Dichloroethylene

trans-1,2-

Dichloroethylene

1,2-Dichloroethylene

(total)

1,2-Dichloropropane trans-1,3- Dichloro propene 1,2-Dichloro- benzene 1,3-Dichloro- benzene 1,4-Dichloro- benzene

BK-2527 -- -- 21 <10 <10 -- -- --BK-2527 20 <0.5 20 -- -- -- -- --BK-2527 20 .2 20 .6 -- <0.1 <0.1 <0.1BK-2528 -- -- 3 J <10 <10 -- -- --BK-2528 1.5 < .5 1.5 -- -- -- -- --BK-2528 5.3 < .1 5.3 < .1 -- < .1 < .1 < .1BK-2809 -- -- 7,700 JD <10 <10 <10 <10 <10BK-2810 -- -- <50 <50 <50 <10 <10 <10BK-2810 120 1.1 J 120 -- -- -- -- --BK-2810 9.2 <1 -- <1 -- <1 <1 <1BK-2811 -- -- 17,000 D 22 <10 <10 <10 <10BK-2811 5,100 54 J 5,200 -- -- -- -- --BK-2811 13,800 78 -- 14.4 -- <10 <10 <10BK-2827 -- -- <10 <10 <10 <10 <10 <10BK-2827 54 < .5 54 -- -- -- -- --BK-2827 1.9 < .1 1.9 < .1 -- < .1 < .1 < .1BK-3034 27 .2 -- .2 -- < .1 < .1 < .1BK-3042 1.5 < .1 -- < .1 -- < .1 < .1 < .1BK-3043 11 .2 -- .2 -- < .1 < .1 < .1BK-3045 8.8 .2 -- .3 -- < .1 < .1 < .1BK-3046 < .1 < .1 -- < .1 -- < .1 < .1 < .1MG-946 -- -- -- -- -- -- -- --MG-946 -- -- -- -- -- -- -- --MG-946 -- < .2 -- < .2 -- < .2 < .2 < .2MG-2149 .22 < .1 -- < .1 -- < .1 < .1 < .1
80 Changes in Groundwater Flow and Volatile Organic Compound Concentrations, Fischer and Porter Superfund Site Table 1–2. Volatile organic compounds analyzed in groundwater, Fischer and Porter Site, Warminster Township, Bucks County, Pennsylvania, 1979–2009.—Continued [Concentrationsw given in micrograms per liter; USGS, U.S. Geological Survey; --, not analyzed; <, less than; ND, not detected, detection limit not sepecified; B, compound reported in field blank; E, estimated concentration below minimum reporting level; D, diluted sample; J, estimated concentration below minimum reporting level. Source of data: 1, SMC Martin, Inc. (1980); 2, CH2M Hill, Inc. (1998); 3, Tetra Tech EM, Inc. (2005); 4, this study] USGS well- identification number 1,4-Dioxane 2-Butanone 2-Hexanone 2-Methyl- 2-butanol 4-Methyl- 2-pentanone Acetone Benzene Bromo- dichloro- methane BK-366 -- -- -- -- -- -- -- -- BK-366 -- -- -- -- -- -- -- -- BK-366 -- -- -- -- -- ND -- -- BK-366 -- -- -- -- -- -- <0.1 <0.1 BK-367 -- -- -- -- -- -- -- -- BK-367 -- -- -- -- -- -- -- -- BK-367 -- -- -- -- -- ND -- -- BK-367 -- -- -- -- -- -- < .1 < .1 BK-368 -- -- -- -- -- -- -- -- BK-368 -- -- -- -- -- -- -- -- BK-370 -- -- -- -- -- -- -- -- BK-370 -- -- -- -- -- -- -- -- BK-371 -- -- -- -- -- -- -- -- BK-371 -- -- -- -- -- -- -- -- BK-372 -- -- -- -- -- -- -- -- BK-372 -- -- -- -- -- -- -- -- BK-370 + BK-371 -- -- -- -- -- -- -- -- BK-370 + BK-371 -- <10 <10 -- <10 <10 <10 <10 BK-370 + BK-371 -- -- -- -- -- -- < .5 -- BK-370 + BK-371 -- -- -- -- -- -- <10 <10 BK-370 + BK-371 <2.9 -- -- <0.6 -- <1.8 .05 E < .1 BK-1030 -- -- -- -- -- -- < .1 < .1
Appendix 1. Chemical Analyses 81

Table 1–2. Volatile organic compounds analyzed in groundwater, Fischer and Porter Site, Warminster Township, Bucks County, Pennsylvania, 1979–2009.—Continued[Concentrationsw given in micrograms per liter; USGS, U.S. Geological Survey; --, not analyzed; <, less than; ND, not detected, detection limit not sepecified; B, compound reported in fieldblank; E, estimated concentration below minimum reporting level; D, diluted sample; J, estimated concentration below minimum reporting level. Source of data: 1, SMC Martin, Inc. (1980);2, CH2M Hill, Inc. (1998); 3, Tetra Tech EM, Inc. (2005); 4, this study]

USGS

wellidentification 

number

1,4-Dioxane 2-Butanone 2-Hexanone 2-Methyl- 2-butanol 4-Methyl- 2-pentanone Acetone Benzene Bromo- dichloro- methane

BK-1324 -- -- -- -- -- -- -- --BK-1324 -- -- -- -- -- -- -- --BK-1324 -- -- -- -- -- ND -- --BK-1324 -- -- -- -- -- -- 2 J --BK-1324 -- -- -- -- -- -- < .5 --BK-1324 -- -- -- -- -- -- <1 <1BK-1324 5.7 -- -- <0.6 -- <1.8 .19 < .1BK-1731 -- <10 <10 -- <10 <10 <10 <10BK-1731 -- -- -- -- -- -- < .5 --BK-1731 -- -- -- -- -- -- < .1 < .1BK-1793 -- -- -- -- -- -- -- --BK-1793 -- -- -- -- -- -- -- --BK-1793 -- <10 <10 -- <10 <10 5 J <10BK-1793 -- -- -- -- -- -- 5.4 --BK-1793 -- -- -- -- -- -- <1.7 < .1BK-1795 -- -- -- -- -- -- -- --BK-1795 -- -- -- -- -- -- -- --BK-1795 -- <10 <10 -- <10 <10 <10 <10BK-1796 -- <10 <10 -- <10 6 B <10 <10

-- --

BK-2511 -- <10 <10 -- <10 <10 <10 <10BK-2511 -- -- -- -- -- -- < .5 --BK-2511 -- -- -- -- -- -- < .1 < .1BK-2512 -- <10 <10 -- <10 <10 <10 <10BK-2512 -- -- -- -- -- -- < .5 --BK-2512 -- -- -- -- -- -- < .1 < .1
82 Changes in Groundwater Flow and Volatile Organic Compound Concentrations, Fischer and Porter Superfund Site Table 1–2. Volatile organic compounds analyzed in groundwater, Fischer and Porter Site, Warminster Township, Bucks County, Pennsylvania, 1979–2009.—Continued [Concentrationsw given in micrograms per liter; USGS, U.S. Geological Survey; --, not analyzed; <, less than; ND, not detected, detection limit not sepecified; B, compound reported in field blank; E, estimated concentration below minimum reporting level; D, diluted sample; J, estimated concentration below minimum reporting level. Source of data: 1, SMC Martin, Inc. (1980); 2, CH2M Hill, Inc. (1998); 3, Tetra Tech EM, Inc. (2005); 4, this study] USGS well- identification number 1,4-Dioxane 2-Butanone 2-Hexanone 2-Methyl- 2-butanol 4-Methyl- 2-pentanone Acetone Benzene Bromo- dichloro- methane BK-2513 -- <10 <10 -- <10 12 B <10 <10 BK-2513 -- -- -- -- -- -- < .5 -- BK-2513 -- -- -- -- -- -- < .1 < .1 BK-2514 -- <10 <10 -- <10 <10 <10 <10 BK-2514 -- -- -- -- -- -- < .1 < .1 BK-2515 -- <10 <10 -- <10 7 B <10 <10 BK-2515 -- -- -- -- -- -- < .5 -- BK-2515 -- -- -- -- -- -- < .1 < .1 BK-2521 -- <10 <10 -- <10 <10 <10 <10 BK-2521 -- -- -- -- -- -- < .5 -- BK-2521 -- -- -- -- -- -- < .1 < .1 BK-2522 -- <10 <10 -- <10 <10 <10 <10 BK-2522 -- -- -- -- -- -- < .5 -- BK-2522 -- -- -- -- -- -- <1 <1 BK-2523 -- -- -- -- -- -- < .5 -- BK-2523 -- -- -- -- -- -- < .1 < .1 BK-2524 -- <10 <10 -- <10 5 B <10 <10 BK-2524 -- -- -- -- -- -- < .5 -- BK-2524 -- -- -- -- -- -- < .1 < .1 BK-2525 -- <10 <10 -- <10 7 B <10 <10 BK-2525 -- -- -- -- -- -- < .5 -- BK-2525 -- -- -- -- -- -- < .1 < .1 BK-2526 -- <10 <10 -- <10 <10 <10 <10 BK-2526 -- -- -- -- -- -- < .5 --

BK-2526 -- -- -- -- -- -- < .1 < .1
Appendix 1. Chemical Analyses 83

Table 1–2. Volatile organic compounds analyzed in groundwater, Fischer and Porter Site, Warminster Township, Bucks County, Pennsylvania, 1979–2009.—Continued[Concentrationsw given in micrograms per liter; USGS, U.S. Geological Survey; --, not analyzed; <, less than; ND, not detected, detection limit not sepecified; B, compound reported in fieldblank; E, estimated concentration below minimum reporting level; D, diluted sample; J, estimated concentration below minimum reporting level. Source of data: 1, SMC Martin, Inc. (1980);2, CH2M Hill, Inc. (1998); 3, Tetra Tech EM, Inc. (2005); 4, this study]

USGS

wellidentification 

number

1,4-Dioxane 2-Butanone 2-Hexanone 2-Methyl- 2-butanol 4-Methyl- 2-pentanone Acetone Benzene Bromo- dichloro- methane

BK-2527 -- <10 <10 -- <10 23 B <10 <10BK-2527 -- -- -- -- -- -- < .5 --BK-2527 -- -- -- -- -- -- < .1 < .1BK-2528 -- <10 <10 -- <10 4 B <10 <10BK-2528 -- -- -- -- -- -- < .5 --BK-2528 -- -- -- -- -- -- < .1 < .1BK-2809 -- <10 <10 -- <10 12 B 5 J <10BK-2810 -- <50 <50 -- <50 <50 <50 <50BK-2810 -- -- -- -- -- -- 1.8 J --BK-2810 -- -- -- -- -- -- <2.1 <1BK-2811 -- <10 <10 -- <10 8 B 14 <10BK-2811 -- -- -- -- -- -- < .5 --BK-2811 -- -- -- -- -- -- <10 <10BK-2827 -- <10 <10 -- <10 6 B <10 <10BK-2827 -- -- -- -- -- -- < .5 --BK-2827 -- -- -- -- -- -- < .1 < .1BK-3034 -- -- -- -- -- -- < .1 < .1BK-3042 -- -- -- -- -- -- < .1 < .1BK-3043 -- -- -- -- -- -- < .1 < .1BK-3045 -- -- -- -- -- -- < .1 < .1BK-3046 -- -- -- -- -- -- < .1 < .1MG-946 -- -- -- -- -- -- -- --MG-946 -- -- -- -- -- -- -- --MG-946 -- -- -- -- -- -- < .2 < .2MG-2149 -- -- -- -- -- -- < .1 < .1
84 Changes in Groundwater Flow and Volatile Organic Compound Concentrations, Fischer and Porter Superfund Site Table 1–2. Volatile organic compounds analyzed in groundwater, Fischer and Porter Site, Warminster Township, Bucks County, Pennsylvania, 1979–2009.—Continued [Concentrationsw given in micrograms per liter; USGS, U.S. Geological Survey; --, not analyzed; <, less than; ND, not detected, detection limit not sepecified; B, compound reported in field blank; E, estimated concentration below minimum reporting level; D, diluted sample; J, estimated concentration below minimum reporting level. Source of data: 1, SMC Martin, Inc. (1980); 2, CH2M Hill, Inc. (1998); 3, Tetra Tech EM, Inc. (2005); 4, this study] USGS well- identification number Bromoform Carbon disulfide Carbon tetrachloride Chloro- benzene Chloro- ethane Chloro- methane Chloroform Dichloro- difluoro- methane Dibromo- chloro- methane BK-366 -- -- -- -- -- -- ND -- -- BK-366 -- -- -- -- -- -- ND–0.4 -- -- BK-366 -- -- -- -- -- -- -- -- -- BK-366 <0.2 -- <0.2 <0.1 -- -- 0.5 -- <0.2 BK-367 -- -- -- -- -- -- -- -- -- BK-367 -- -- -- -- -- -- ND–0.3 -- -- BK-367 -- -- -- -- -- -- -- -- -- BK-367 < .2 -- < .2 < .1 -- -- .4 <0.2 < .2 BK-368 -- -- -- -- -- -- ND -- -- BK-368 -- -- -- -- -- -- ND–2.2 -- -- BK-370 -- -- -- -- -- -- -- -- -- BK-370 -- -- -- -- -- -- ND–8 -- -- BK-371 -- -- -- -- -- -- -- -- -- BK-371 -- -- -- -- -- -- -- -- -- BK-372 -- -- -- -- -- -- -- -- -- BK-372 -- -- -- -- -- -- -- -- -- BK-370 + BK-371 -- -- -- -- -- -- -- -- -- BK-370 + BK-371 <10 <10 <10 <10 <10 <10 4 J -- <10 BK-370 + BK-371 -- -- -- -- -- -- -- -- -- BK-370 + BK-371 <20 -- <20 <10 -- -- <10 <20 <20 BK-370 + BK-371 < .2 -- < .2 < .1 -- -- .3 < .2 < .2 BK-1030 < .2 -- < .2 < .1 -- -- 1 < .2 < .2
Appendix 1. Chemical Analyses 85

Table 1–2. Volatile organic compounds analyzed in groundwater, Fischer and Porter Site, Warminster Township, Bucks County, Pennsylvania, 1979–2009.—Continued[Concentrationsw given in micrograms per liter; USGS, U.S. Geological Survey; --, not analyzed; <, less than; ND, not detected, detection limit not sepecified; B, compound reported in fieldblank; E, estimated concentration below minimum reporting level; D, diluted sample; J, estimated concentration below minimum reporting level. Source of data: 1, SMC Martin, Inc. (1980);2, CH2M Hill, Inc. (1998); 3, Tetra Tech EM, Inc. (2005); 4, this study]

USGS

wellidentification 

number

Bromoform Carbon disulfide Carbon tetrachloride Chloro- benzene Chloro- ethane Chloro- methane Chloroform Dichloro- difluoro- methane Dibromo- chloro- methane

BK-1324 -- -- -- -- -- -- ND -- --

BK-1324 -- -- -- -- -- -- ND -- --BK-1324 -- -- -- -- -- -- -- -- --BK-1324 -- -- -- -- -- -- 2 J -- --BK-1324 -- -- -- -- -- -- -- -- --BK-1324 <2 -- -- <1 -- -- 1.1 <2 <2BK-1324 < .2 -- <0.2 < .1 -- -- .7 < .2 < .2BK-1731 <10 <10 <10 <10 <10 <10 <10 -- <10BK-1731 -- -- -- -- -- -- -- -- --BK-1731 < .2 -- < .2 < .1 -- -- < .1 <0.2 < .2BK-1793 -- -- -- -- -- -- .9 -- --BK-1793 -- -- -- -- -- -- ND–0.9 -- --BK-1793 <10 <10 <10 <10 <10 <10 <10 -- <10BK-1793 -- -- -- -- -- -- -- -- --BK-1793 < .2 -- < .2 < .1 -- -- < .1 < .2 < .2BK-1795 -- -- -- -- -- -- 2.1 -- --BK-1795 -- -- -- -- -- -- ND–2.1 -- --BK-1795 <10 <10 <10 <10 <10 <10 <10 -- <10BK-1796 <10 <10 <10 <10 <10 <10 <10 -- <10BK-2511 <10 <10 <10 <10 <10 <10 <10 -- <10BK-2511 -- -- -- -- -- -- -- -- --BK-2511 < .2 -- < .2 < .1 -- -- < .1 < .2 < .2BK-2512 <10 <10 <10 <10 <10 <10 <10 -- <10BK-2512 -- -- -- -- -- -- -- -- --BK-2512 < .2 -- < .2 < .1 -- -- .4 < .2 < .2
86 Changes in Groundwater Flow and Volatile Organic Compound Concentrations, Fischer and Porter Superfund Site Table 1–2. Volatile organic compounds analyzed in groundwater, Fischer and Porter Site, Warminster Township, Bucks County, Pennsylvania, 1979–2009.—Continued [Concentrationsw given in micrograms per liter; USGS, U.S. Geological Survey; --, not analyzed; <, less than; ND, not detected, detection limit not sepecified; B, compound reported in field blank; E, estimated concentration below minimum reporting level; D, diluted sample; J, estimated concentration below minimum reporting level. Source of data: 1, SMC Martin, Inc. (1980); 2, CH2M Hill, Inc. (1998); 3, Tetra Tech EM, Inc. (2005); 4, this study] USGS well- identification number Bromoform Carbon disulfide Carbon tetrachloride Chloro- benzene Chloro- ethane Chloro- methane Chloroform Dichloro- difluoro- methane Dibromo- chloro- methane BK-2513 <10 <10 <10 <10 <10 <10 <10 -- <10 BK-2513 -- -- -- -- -- -- -- -- -- BK-2513 < .2 -- < .2 < .1 -- -- < .1 <0.2 < .2 BK-2514 <10 <10 <10 <10 <10 <10 <10 -- <10 BK-2514 < .2 -- < .2 < .1 -- -- .4 < .2 < .2 BK-2515 <10 <10 <10 <10 <10 <10 <10 -- <10 BK-2515 -- -- -- -- -- -- -- -- -- BK-2515 < .2 -- < .2 < .1 -- -- < .1 < .2 < .2 BK-2521 <10 <10 <10 <10 <10 <10 <10 -- <10 BK-2521 -- -- -- -- -- -- -- -- -- BK-2521 < .2 -- < .2 < .1 -- -- .4 < .2 < .2 BK-2522 <10 <10 <10 <10 <10 <10 <10 -- <10 BK-2522 -- -- -- -- -- -- -- -- -- BK-2522 <2 -- <2 <1 -- -- 1.8 <2 <2 BK-2523 -- -- -- -- -- -- -- -- -- BK-2523 < .2 -- < .2 < .1 -- -- .2 < .2 < .2 BK-2524 <10 <10 <10 <10 <10 <10 <1 -- <10 BK-2524 -- -- -- -- -- -- -- -- -- BK-2524 < .2 -- < .2 < .1 -- -- .5 < .2 < .2 BK-2525 <10 <10 <10 <10 <10 <10 <10 -- <10 BK-2525 -- -- -- -- -- -- -- -- -- BK-2525 < .2 -- < .2 < .1 -- -- < .1 < .2 < .2 BK-2526 <10 <10 <10 <10 <10 <10 <10 -- <10 BK-2526 -- -- -- -- -- -- -- -- -- BK-2526 < .2 -- < .2 < .1 -- -- .1 < .2 < .2
Appendix 1. Chemical Analyses 87

Table 1–2. Volatile organic compounds analyzed in groundwater, Fischer and Porter Site, Warminster Township, Bucks County, Pennsylvania, 1979–2009.—Continued[Concentrationsw given in micrograms per liter; USGS, U.S. Geological Survey; --, not analyzed; <, less than; ND, not detected, detection limit not sepecified; B, compound reported in fieldblank; E, estimated concentration below minimum reporting level; D, diluted sample; J, estimated concentration below minimum reporting level. Source of data: 1, SMC Martin, Inc. (1980);2, CH2M Hill, Inc. (1998); 3, Tetra Tech EM, Inc. (2005); 4, this study]

USGS

wellidentification 

number

Bromoform Carbon disulfide Carbon tetrachloride Chloro- benzene Chloro- ethane Chloro- methane Chloroform Dichloro- difluoro- methane Dibromo- chloro- methane

BK-2527 <10 <10 <10 <10 <10 <10 <10 -- <10BK-2527 -- -- -- -- -- -- -- -- --

BK-2527 < .2 -- < .2 < .1 -- -- .3 <0.2 < .2BK-2528 <10 <10 <10 <10 <10 <10 <10 -- <10BK-2528 -- -- -- -- -- -- -- -- --BK-2528 < .2 -- < .2 < .1 -- -- < .1 < .2 < .2BK-2809 <10 <10 1J <10 11 <10 32 -- <10BK-2810 <50 <50 <50 <50 <50 <50 <50 -- <50BK-2810 -- -- -- -- -- -- -- -- --BK-2810 <2 -- <2 <1 -- -- <1 <2 <2BK-2811 <10 <10 1 J <10 <10 <10 58 -- <10BK-2811 -- -- -- -- -- -- -- -- --BK-2811 <20 -- <20 <10 -- -- 38 <20 <20BK-2827 <10 <10 <10 <10 <10 <10 <10 -- <10BK-2827 -- -- -- -- -- -- -- -- --BK-2827 < .2 -- < .2 < .1 -- -- < .1 < .2 < .2BK-3034 < .2 -- < .2 < .1 -- -- .6 < .2 < .2BK-3042 < .2 -- < .2 < .1 -- -- < .1 < .2 < .2BK-3043 < .2 -- < .2 < .1 -- -- .1 < .2 < .2BK-3045 < .2 -- < .2 -- < .1 -- .2 < .2 < .2BK-3046 < .2 -- < .2 < .1 -- -- .2 < .2 < .2MG-946 -- -- -- -- -- -- -- -- --MG-946 -- -- -- -- -- -- ND–0.4 -- --MG-946 < .2 -- < .2 < .2 -- < .2 .3 < .2 < .2MG-2149 < .2 -- < .2 < .1 -- -- < .1 < .2 < .2
88 Changes in Groundwater Flow and Volatile Organic Compound Concentrations, Fischer and Porter Superfund Site Table 1–2. Volatile organic compounds analyzed in groundwater, Fischer and Porter Site, Warminster Township, Bucks County, Pennsylvania, 1979–2009.—Continued [Concentrationsw given in micrograms per liter; USGS, U.S. Geological Survey; --, not analyzed; <, less than; ND, not detected, detection limit not sepecified; B, compound reported in field blank; E, estimated concentration below minimum reporting level; D, diluted sample; J, estimated concentration below minimum reporting level. Source of data: 1, SMC Martin, Inc. (1980); 2, CH2M Hill, Inc. (1998); 3, Tetra Tech EM, Inc. (2005); 4, this study] USGS well- identification number cis-1,3- Dichloro- propene Diethyl ether Diisopropyl ether Ethyl benzene Ethyl tert-butyl ether Methyl acetate Methylene chloride Styrene BK-366 -- -- -- -- -- -- -- -- BK-366 -- -- -- -- -- -- -- -- BK-366 -- -- -- -- -- -- ND -- BK-366 -- <0.2 <0.2 <0.1 <0.1 -- <0.2 <0.1 BK-367 -- -- -- -- -- -- -- -- BK-367 -- -- -- -- -- -- -- -- BK-367 -- -- -- -- -- -- 2 B -- BK-367 -- < .2 < .2 < .1 < .1 -- < .2 < .1 BK-368 -- -- -- -- -- -- -- -- BK-368 -- -- -- -- -- -- -- -- BK-370 -- -- -- -- -- -- -- -- BK-370 -- -- -- -- -- -- -- -- BK-371 -- -- -- -- -- -- -- -- BK-371 -- -- -- -- -- -- -- -- BK-372 -- -- -- -- -- -- -- -- BK-372 -- -- -- -- -- -- -- -- BK-370 + BK-371 -- -- -- -- -- -- 1 B -- BK-370 + BK-371 <10 -- -- <10 -- -- 3 B <10 BK-370 + BK-371 -- -- -- -- -- -- -- -- BK-370 + BK-371 -- <20 <20 <10 <10 -- <20 <10 BK-370 + BK-371 -- < .2 < .04 < .02 < .1 <0.4 < .2 < .1 BK-1030 -- < .2 < .2 < .1 < .1 -- < .2 < .1
Appendix 1. Chemical Analyses 89

Table 1–2. Volatile organic compounds analyzed in groundwater, Fischer and Porter Site, Warminster Township, Bucks County, Pennsylvania, 1979–2009.—Continued[Concentrationsw given in micrograms per liter; USGS, U.S. Geological Survey; --, not analyzed; <, less than; ND, not detected, detection limit not sepecified; B, compound reported in fieldblank; E, estimated concentration below minimum reporting level; D, diluted sample; J, estimated concentration below minimum reporting level. Source of data: 1, SMC Martin, Inc. (1980);2, CH2M Hill, Inc. (1998); 3, Tetra Tech EM, Inc. (2005); 4, this study]

USGS

wellidentification 

number

cis-1,3-

Dichloropropene Diethyl ether Diisopropyl ether Ethyl benzene Ethyl tert-butyl ether Methyl acetate Methylene chloride Styrene

BK-1324 -- -- -- -- -- -- -- --BK-1324 -- -- -- -- -- -- -- --BK-1324 -- -- -- -- -- -- 2 B --BK-1324 -- -- -- -- -- -- 18 B --BK-1324 -- -- -- -- -- -- -- --BK-1324 -- <2 <2 <1 <1 -- <2 <1BK-1324 -- < .2 < .04 .01 E -- <0.4 < .2 < .1BK-1731 <10 -- -- <10 -- -- <10 <10BK-1731 -- -- -- -- -- -- -- --BK-1731 -- <0.2 <0.2 < .1 <0.1 -- < .2 < .1BK-1793 -- -- -- -- -- -- -- --BK-1793 -- -- -- -- -- -- -- --BK-1793 <10 -- -- <10 -- -- <10 <10BK-1793 -- -- -- -- -- -- -- --BK-1793 -- < .2 < .2 < .1 < .1 -- < .2 < .1BK-1795 -- -- -- -- -- -- -- --BK-1795 -- -- -- -- -- -- -- --BK-1795 <10 -- -- <10 -- -- <10 <10BK-1796 <10 -- -- <10 -- -- 6 B <10

--

BK-2511 <10 -- -- <10 -- -- <10 <10BK-2511 -- -- -- -- -- -- -- --BK-2511 -- < .2 < .2 < .1 < .1 -- < .2 < .1BK-2512 <10 -- -- <10 -- -- <10 <10BK-2512 -- -- -- -- -- -- -- --BK-2512 -- < .2 < .2 < .1 < .1 -- < .2 < .1
90 Changes in Groundwater Flow and Volatile Organic Compound Concentrations, Fischer and Porter Superfund Site Table 1–2. Volatile organic compounds analyzed in groundwater, Fischer and Porter Site, Warminster Township, Bucks County, Pennsylvania, 1979–2009.—Continued [Concentrationsw given in micrograms per liter; USGS, U.S. Geological Survey; --, not analyzed; <, less than; ND, not detected, detection limit not sepecified; B, compound reported in field blank; E, estimated concentration below minimum reporting level; D, diluted sample; J, estimated concentration below minimum reporting level. Source of data: 1, SMC Martin, Inc. (1980); 2, CH2M Hill, Inc. (1998); 3, Tetra Tech EM, Inc. (2005); 4, this study] USGS well- identification number cis-1,3- Dichloro- propene Diethyl ether Diisopropyl ether Ethyl benzene Ethyl tert-butyl ether Methyl acetate Methylene chloride Styrene BK-2513 <10 -- -- <10 -- -- 2 B <10 BK-2513 -- -- -- -- -- -- -- -- BK-2513 -- <0.2 <0.2 < .1 <0.1 -- < .2 < .1 BK-2514 <10 -- -- <10 -- -- <10 <10 BK-2514 -- < .2 < .2 < .1 < .1 -- < .2 < .1 BK-2515 <10 -- -- <10 -- -- 5 B <10 BK-2515 -- -- -- -- -- -- -- -- BK-2515 -- < .2 < .2 < .1 < .1 -- < .2 < .1 BK-2521 <10 -- -- <10 -- -- 7 B <10 BK-2521 -- -- -- -- -- -- -- -- BK-2521 -- < .2 < .2 < .1 < .1 -- < .2 < .1 BK-2522 <10 -- -- <10 -- -- <10 <10 BK-2522 -- -- -- -- -- -- -- -- BK-2522 -- <2 <2 <1 <1 -- <2 <1 BK-2523 -- -- -- -- -- -- -- -- BK-2523 -- < .2 < .2 < .1 < .1 -- < .2 < .1 BK-2524 <10 -- -- <10 -- -- 3 B <10 BK-2524 -- -- -- -- -- -- -- -- BK-2524 -- < .2 < .2 < .1 < .1 -- < .2 < .1 BK-2525 <10 -- -- <10 -- -- 2 B <10 BK-2525 -- -- -- -- -- -- -- -- BK-2525 -- < .2 < .2 < .1 < .1 -- < .2 < .1 BK-2526 <10 -- -- <10 -- -- <10 <10 BK-2526 -- -- -- -- -- -- -- -- BK-2526 -- < .2 < .2 < .1 < .1 -- < .2 < .1
Appendix 1. Chemical Analyses 91

Table 1–2. Volatile organic compounds analyzed in groundwater, Fischer and Porter Site, Warminster Township, Bucks County, Pennsylvania, 1979–2009.—Continued[Concentrationsw given in micrograms per liter; USGS, U.S. Geological Survey; --, not analyzed; <, less than; ND, not detected, detection limit not sepecified; B, compound reported in fieldblank; E, estimated concentration below minimum reporting level; D, diluted sample; J, estimated concentration below minimum reporting level. Source of data: 1, SMC Martin, Inc. (1980);2, CH2M Hill, Inc. (1998); 3, Tetra Tech EM, Inc. (2005); 4, this study]

USGS

wellidentification 

number

cis-1,3-

Dichloropropene Diethyl ether Diisopropyl ether Ethyl benzene Ethyl tert-butyl ether Methyl acetate Methylene chloride Styrene

BK-2527 <10 -- -- <10 -- -- 8 B <10

BK-2527 -- -- -- -- -- -- -- --BK-2527 -- <0.2 <0.2 < .1 <0.1 -- < .2 < .1BK-2528 <10 -- -- <10 -- -- 5 B <10BK-2528 -- -- -- -- -- -- -- --BK-2528 -- < .2 < .2 < .1 < .1 -- < .2 < .1BK-2809 <10 -- -- <10 -- -- 280 JD <10BK-2810 <50 -- -- <50 -- -- <50 <50BK-2810 -- -- -- -- -- -- -- --BK-2810 -- <2 <2 <1 <1 -- <2 <1BK-2811 <10 -- -- <10 -- -- 10 B <10BK-2811 -- -- -- -- -- -- -- --BK-2811 -- <20 <20 <10 <10 -- <20 <10BK-2827 <10 -- -- <10 -- -- <10 <10BK-2827 -- -- -- -- -- -- -- --BK-2827 -- < .2 < .2 < .1 < .1 -- < .2 < .1BK-3034 -- < .2 < .2 < .1 < .1 -- < .2 < .1BK-3042 -- < .2 < .2 < .1 < .1 -- < .2 < .1BK-3043 -- < .2 < .2 < .1 < .1 -- < .2 < .1BK-3045 -- < .2 < .2 < .1 < .1 -- < .2 < .1BK-3046 -- < .2 < .2 < .1 < .1 -- < .2 < .1MG-946 -- -- -- -- -- -- -- --MG-946 -- -- -- -- -- -- -- --MG-946 < .2 -- -- < .2 -- -- < .2 < .2MG-2149 -- < .2 < .2 < .1 < .1 -- < .2 < .1
92 Changes in Groundwater Flow and Volatile Organic Compound Concentrations, Fischer and Porter Superfund Site Table 1–2. Volatile organic compounds analyzed in groundwater, Fischer and Porter Site, Warminster Township, Bucks County, Pennsylvania, 1979–2009.—Continued [Concentrationsw given in micrograms per liter; USGS, U.S. Geological Survey; --, not analyzed; <, less than; ND, not detected, detection limit not sepecified; B, compound reported in field blank; E, estimated concentration below minimum reporting level; D, diluted sample; J, estimated concentration below minimum reporting level. Source of data: 1, SMC Martin, Inc. (1980); 2, CH2M Hill, Inc. (1998); 3, Tetra Tech EM, Inc. (2005); 4, this study] USGS well- identification number Tert-butyl alcohol Tert-butyl ethyl ether Tert-butyl methyl ether (MTBE) Tert-pentyl methyl ether Tetrachloro- ethylene Toluene Trichloro- ethylene Trichloro- fluoro- methane BK-366 -- -- -- -- 5.7 -- 45 -- BK-366 -- -- -- -- 0.3–<7 -- 8.9–45 -- BK-366 -- -- -- -- 3 J -- 43 -- BK-366 -- -- <0.2 <0.2 .6 <0.1 6.2 <0.2 BK-367 -- -- -- -- 25 -- 3 -- BK-367 -- -- -- -- 13–33 -- 0.6–3 -- BK-367 -- -- -- -- 34 -- 2 J -- BK-367 -- -- < .2 < .2 .2 .1 .1 < .2 BK-368 -- -- -- -- 30 -- 350 -- BK-368 -- -- -- -- 14–30 -- 131–350 -- BK-370 -- -- -- -- 26,000 -- 87,000 -- BK-370 -- -- -- -- 430–26,000 -- 12,000–87,000 -- BK-371 -- -- -- -- 3 -- 14,000 -- BK-371 -- -- -- -- ND–190 -- 120–14,000 -- BK-372 -- -- -- -- 1.9 -- 2.6 -- BK-372 -- -- -- -- .5 -- ND -- BK-370 + BK-371 -- -- -- -- 4 J -- >1,500 -- BK-370 + BK-371 -- -- -- -- 130 <10 7,600 D -- BK-370 + BK-371 -- -- -- -- 32 J -- 1,900 -- BK-370 + BK-371 -- -- <20 <20 51 <10 3,000 <20 BK-370 + BK-371 <1 <0.04 .08 E 12 < .02 280 < .2 BK-1030 -- -- < .2 < .2 1.7 < .1 14 < .2
Appendix 1. Chemical Analyses 93

Table 1–2. Volatile organic compounds analyzed in groundwater, Fischer and Porter Site, Warminster Township, Bucks County, Pennsylvania, 1979–2009.—Continued[Concentrationsw given in micrograms per liter; USGS, U.S. Geological Survey; --, not analyzed; <, less than; ND, not detected, detection limit not sepecified; B, compound reported in fieldblank; E, estimated concentration below minimum reporting level; D, diluted sample; J, estimated concentration below minimum reporting level. Source of data: 1, SMC Martin, Inc. (1980);2, CH2M Hill, Inc. (1998); 3, Tetra Tech EM, Inc. (2005); 4, this study]

USGS

wellidentification 

number

Tert-butyl

alcohol

Tert-butyl

ethyl ether

Tert-butyl

methyl ether

(MTBE)

Tert-pentyl

methyl ether

Tetrachloroethylene Toluene Trichloro- ethylene Trichloro- fluoro- methane

BK-1324 -- -- -- -- 920 -- 15,000 --BK-1324 -- -- -- -- 450–920 -- 10,000–15,000 --BK-1324 -- -- -- -- -- -- >1,500 --BK-1324 -- -- -- -- 51 -- 3,000 --BK-1324 -- -- -- -- 12 J -- 430 --BK-1324 -- -- <2 <2 8.4 <1 340 <2BK-1324 <1 <0.04 .07 E < .04 10 .05 240 < .2BK-1731 -- -- -- -- <10 <10 <10 --BK-1731 -- -- -- -- < .5 -- < .5 --BK-1731 -- -- <0.2 <0.2 < .1 .2 < .1 <0.2BK-1793 -- -- -- -- 21 -- 140 --BK-1793 -- -- -- -- 21–39 -- 87–140 --BK-1793 -- -- -- -- <10 <10 2 B --BK-1793 -- -- -- -- < .5 -- < .5 --BK-1793 -- -- < .2 < .2 < .1 5.2 .2 E < .2BK-1795 -- -- -- -- 2.9 -- 330 --BK-1795 -- -- -- -- ND–2.9 -- 310–540 --BK-1795 -- -- -- -- <10 <10 8 J --BK-1796 -- -- -- -- 3 J <10 150 --

-- --

BK-2511 -- -- -- -- <10 <10 8 J --BK-2511 -- -- -- -- < .5 -- < .5 --BK-2511 -- -- < .2 < .2 < .1 1 1.7 < .2BK-2512 -- -- -- -- 13 <10 190 --BK-2512 -- -- -- -- 3.0 J -- 82 --BK-2512 -- -- < .2 < .2 8.4 .3 86 < .2
94 Changes in Groundwater Flow and Volatile Organic Compound Concentrations, Fischer and Porter Superfund Site Table 1–2. Volatile organic compounds analyzed in groundwater, Fischer and Porter Site, Warminster Township, Bucks County, Pennsylvania, 1979–2009.—Continued [Concentrationsw given in micrograms per liter; USGS, U.S. Geological Survey; --, not analyzed; <, less than; ND, not detected, detection limit not sepecified; B, compound reported in field blank; E, estimated concentration below minimum reporting level; D, diluted sample; J, estimated concentration below minimum reporting level. Source of data: 1, SMC Martin, Inc. (1980); 2, CH2M Hill, Inc. (1998); 3, Tetra Tech EM, Inc. (2005); 4, this study] USGS well- identification number Tert-butyl alcohol Tert-butyl ethyl ether Tert-butyl methyl ether (MTBE) Tert-pentyl methyl ether Tetrachloro- ethylene Toluene Trichloro- ethylene Trichloro- fluoro- methane BK-2513 -- -- -- -- <10 <10 3 B -- BK-2513 -- -- -- -- < .5 -- 1.4 -- BK-2513 -- -- <0.2 <0.2 .2 < .1 2.3 <0.2 BK-2514 -- -- -- -- <10 <10 1 B -- BK-2514 -- -- < .2 < .2 7.6 < .1 1.1 < .2 BK-2515 -- -- -- -- 1 J <10 46 -- BK-2515 -- -- -- -- .11 J -- 11 -- BK-2515 -- -- .8 < .2 .5 .5 28 < .2 BK-2521 -- -- -- -- 2 J <10 52 -- BK-2521 -- -- -- -- 2.6 J -- 84 -- BK-2521 -- -- < .2 <0.2 5.3 1.3 100 < .2 BK-2522 -- -- -- -- 21 J <10 390 -- BK-2522 -- -- -- -- 17 J -- 490 -- BK-2522 -- -- <2 <2 28 <1 500 <2 BK-2523 -- -- -- -- 1.9 -- 27 -- BK-2523 -- -- < .2 < .2 2 .5 20 < .2 BK-2524 -- -- -- -- 13 <10 55 -- BK-2524 -- -- -- -- .67 -- 3.7 -- BK-2524 -- -- < .2 < .2 1.3 < .1 4.4 < .2 BK-2525 -- -- -- -- 2 J <10 8 J -- BK-2525 -- -- -- -- .43 J -- 5.2 -- BK-2525 -- -- .4 < .2 .7 .1 3.9 < .2 BK-2526 -- -- -- -- <10 <10 <10 -- BK-2526 -- -- -- -- < .5 -- .34 J -- BK-2526 -- -- < .2 < .2 < .1 < .1 < .1 < .2
Appendix 1. Chemical Analyses 95

Table 1–2. Volatile organic compounds analyzed in groundwater, Fischer and Porter Site, Warminster Township, Bucks County, Pennsylvania, 1979–2009.—Continued[Concentrationsw given in micrograms per liter; USGS, U.S. Geological Survey; --, not analyzed; <, less than; ND, not detected, detection limit not sepecified; B, compound reported in fieldblank; E, estimated concentration below minimum reporting level; D, diluted sample; J, estimated concentration below minimum reporting level. Source of data: 1, SMC Martin, Inc. (1980);2, CH2M Hill, Inc. (1998); 3, Tetra Tech EM, Inc. (2005); 4, this study]

USGS

wellidentification 

number

Tert-butyl

alcohol

Tert-butyl

ethyl ether

Tert-butyl

methyl ether

(MTBE)

Tert-pentyl

methyl ether

Tetrachloroethylene Toluene Trichloro- ethylene Trichloro- fluoro- methane

BK-2527 -- -- -- -- 10 <10 210 D --BK-2527 -- -- -- -- 4.3 J -- 230 --BK-2527 -- -- <0.2 <0.2 12 .8 240 <0.2BK-2528 -- -- -- -- <10 <10 4 B --BK-2528 -- -- -- -- < .5 -- 2.7 --BK-2528 -- -- < .2 < .2 .2 1.6 9.3 < .2BK-2809 -- -- -- -- 470 JD 3 J 34,000 D --BK-2810 -- -- -- -- 38 B <50 720 --BK-2810 -- -- -- -- 1.2 B -- 130 --BK-2810 -- -- <2 <2 3.9 <1 37 <2BK-2811 -- -- -- -- 970 JD 1 J 22,000 D --BK-2811 -- -- -- -- 34 J -- 1,500 --BK-2811 -- -- <20 <20 340 <10 14,000 <20BK-2827 -- -- -- -- <10 <10 <10 --BK-2827 -- -- -- -- 13 -- 14 --BK-2827 -- -- .3 < .2 23 1.3 7.4 < .2BK-3034 -- -- < .2 < .2 7.4 < .1 83 < .2BK-3042 -- -- < .2 < .2 .1 < .1 9.9 < .2BK-3043 -- -- < .2 < .2 4.6 < .1 74 < .2BK-3045 -- -- < .2 < .2 3 < .1 71 < .2BK-3046 -- -- < .2 < .2 .2 < .1 < .1 < .2MG-946 -- -- -- -- -- -- 96 --MG-946 -- -- -- -- 1.6–6.3 -- 34–96 --MG-946 -- -- -- -- 2.9 < .2 12 < .2MG-2149 -- -- 1.2 < .2 .97 < .1 .64 < .2
96 Changes in Groundwater Flow and Volatile Organic Compound Concentrations, Fischer and Porter Superfund Site Table 1–2. Volatile organic compounds analyzed in groundwater, Fischer and Porter Site, Warminster Township, Bucks County, Pennsylvania, 1979–2009.—Continued [Concentrationsw given in micrograms per liter; USGS, U.S. Geological Survey; --, not analyzed; <, less than; ND, not detected, detection limit not sepecified; B, compound reported in field blank; E, estimated concentration below minimum reporting level; D, diluted sample; J, estimated concentration below minimum reporting level. Source of data: 1, SMC Martin, Inc. (1980); 2, CH2M Hill, Inc. (1998); 3, Tetra Tech EM, Inc. (2005); 4, this study] USGS well- identification number Vinyl chloride m- and p-xylene o-Xylene BK-366 -- -- -- BK-366 -- -- -- BK-366 ND -- -- BK-366 <0.2 <0.2 <0.1 BK-367 -- -- -- BK-367 -- -- -- BK-367 ND -- -- BK-367 < .2 < .2 < .1 BK-368 -- -- -- BK-368 -- -- -- BK-370 -- -- -- BK-370 -- -- -- BK-371 -- -- -- BK-371 -- -- -- BK-372 -- -- -- BK-372 -- -- -- BK-370 + BK-371 ND -- -- BK-370 + BK-371 <10 <10 -- BK-370 + BK-371 < .5 -- -- BK-370 + BK-371 <20 <20 <10 BK-370 + BK-371 6.2 < .02 < .02 BK-1030 < .2 < .2 < .1
Appendix 1. Chemical Analyses 97

Table 1–2. Volatile organic compounds analyzed in groundwater, Fischer and Porter Site, Warminster Township, Bucks County, Pennsylvania, 1979–2009.—Continued[Concentrationsw given in micrograms per liter; USGS, U.S. Geological Survey; --, not analyzed; <, less than; ND, not detected, detection limit not sepecified; B, compound reported in fieldblank; E, estimated concentration below minimum reporting level; D, diluted sample; J, estimated concentration below minimum reporting level. Source of data: 1, SMC Martin, Inc. (1980);2, CH2M Hill, Inc. (1998); 3, Tetra Tech EM, Inc. (2005); 4, this study]

USGS

wellidentification 

number

Vinyl chloride m- and p-xylene o-Xylene

BK-1324 -- -- --BK-1324 -- -- --BK-1324 8J -- --BK-1324 95 -- --BK-1324 55 -- --BK-1324 40 <2 <1BK-1324 17 .03 E .11BK-1731 <10 <10 --BK-1731 < .5 -- --BK-1731 < .2 < .2 <0.1BK-1793 -- -- --BK-1793 -- -- --BK-1793 <10 <10 --BK-1793 < .5 -- --BK-1793 .2 E < .2 < .1BK-1795 -- -- --BK-1795 -- -- --BK-1795 <10 <10 --BK-1796 1 J <10 --BK-2511 <10 <10 --BK-2511 < .5 -- --BK-2511 < .2 < .2 < .1BK-2512 <10 <10 --BK-2512 < .5 -- --BK-2512 < .2 < .2 < .1
98 Changes in Groundwater Flow and Volatile Organic Compound Concentrations, Fischer and Porter Superfund Site Table 1–2. Volatile organic compounds analyzed in groundwater, Fischer and Porter Site, Warminster Township, Bucks County, Pennsylvania, 1979–2009.—Continued [Concentrationsw given in micrograms per liter; USGS, U.S. Geological Survey; --, not analyzed; <, less than; ND, not detected, detection limit not sepecified; B, compound reported in field blank; E, estimated concentration below minimum reporting level; D, diluted sample; J, estimated concentration below minimum reporting level. Source of data: 1, SMC Martin, Inc. (1980); 2, CH2M Hill, Inc. (1998); 3, Tetra Tech EM, Inc. (2005); 4, this study] USGS well- identification number Vinyl chloride m- and p-xylene o-Xylene BK-2513 <10 <10 -- BK-2513 < .5 -- -- BK-2513 < .2 < .2 <0.1 BK-2514 <10 <10 -- BK-2514 < .2 < .2 < .1 BK-2515 <10 <10 -- BK-2515 .23 J -- -- BK-2515 .3 E < .2 < .1 BK-2521 <10 <10 -- BK-2521 < .5 -- -- BK-2521 < .2 < .2 <0.1 BK-2522 <10 <10 -- BK-2522 25 -- -- BK-2522 3.7 <2 <1 BK-2523 < .5 -- -- BK-2523 < .2 < .2 < .1 BK-2524 <10 <10 -- BK-2524 < .5 -- -- BK-2524 < .2 < .2 < .1 BK-2525 <10 <10 -- BK-2525 < .5 -- -- BK-2525 < .2 < .2 < .1 BK-2526 <10 <10 -- BK-2526 < .5 -- -- BK-2526 < .2 < .2 < .1
Appendix 1. Chemical Analyses 99

Table 1–2. Volatile organic compounds analyzed in groundwater, Fischer and Porter Site, Warminster Township, Bucks County, Pennsylvania, 1979–2009.—Continued[Concentrationsw given in micrograms per liter; USGS, U.S. Geological Survey; --, not analyzed; <, less than; ND, not detected, detection limit not sepecified; B, compound reported in fieldblank; E, estimated concentration below minimum reporting level; D, diluted sample; J, estimated concentration below minimum reporting level. Source of data: 1, SMC Martin, Inc. (1980);2, CH2M Hill, Inc. (1998); 3, Tetra Tech EM, Inc. (2005); 4, this study]

USGS

wellidentification 

number

Vinyl chloride m- and p-xylene o-Xylene

BK-2527 <10 <10 --BK-2527 < .5 -- --BK-2527 .2 E < .2 <0.1BK-2528 <10 <10 --BK-2528 < .5 -- --BK-2528 < .2 < .2 < .1BK-2809 920 JD 9 J --BK-2810 5 J <50 --BK-2810 29 J -- --BK-2810 2.9 <2 <1BK-2811 970 JD 1 J --BK-2811 2,700 -- --BK-2811 5,000 <20 <10BK-2827 <10 <10 --BK-2827 .49 J -- --BK-2827 < .2 < .2 < .1BK-3034 < .2 < .2 < .1BK-3042 < .2 < .2 < .1BK-3043 < .2 < .2 < .1BK-3045 < .2 < .2 < .1BK-3046 < .2 < .2 < .1MG-946 -- -- --MG-946 -- -- --MG-946 < .2 < .2 --MG-2149 < .2 < .2 < .1
100 Changes in Groundwater Flow and Volatile Organic Compound Concentrations, Fischer and Porter Superfund Site
Appendix 2. Borehole Geophysical Logs 101 Figure 2–1. Borehole geophysical logs for well BK-3042, Fischer and Porter Superfund Site, Warminster Township, Bucks County, Pennsylvania, July 16, 2008. 

CALIPER LOG

HOLE DIAMETER,

IN INCHES

NATURAL GAMMA,

IN COUNTS PER

SECOND

SINGLE POINT

RESISTANCE,

IN OHMS

FLUID

TEMPERATURE, IN

DEGREES CELSIUS

FLUID RESISTIVITY,

IN OHM-METERS

0

50

100150200250300

8 10 12 0 100 200 300 200 300 400 500 600 700 11.5 12.0 12.5 13.0 300 400 500 600

DEPTH, IN FEET BELOW LAND SURFACE

Appendix 2. Borehole Geophysical Logs
102 Changes in Groundwater Flow and Volatile Organic Compound Concentrations, Fischer and Porter Superfund Site Figure 2–2. Borehole geophysical logs for well BK-3043, Fischer and Porter Superfund Site, Warminster Township, Bucks County, Pennsylvania, July 15, 2008. 

DEPTH, IN FEET BELOW LAND SURFACE

0

50

100150200250300350

6 8 10 12 0 100 200 100 200 300 400 500 11 12 13 14 400 500 600 700 800

CALIPER LOG

HOLE DIAMETER,

IN INCHES

NATURAL GAMMA,

IN COUNTS PER

SECOND

SINGLE POINT

RESISTANCE,

IN OHMS

FLUID

TEMPERATURE, IN

DEGREES CELSIUS

FLUID RESISTIVITY,

IN OHM-METERS
Appendix 2. Borehole Geophysical Logs 103 Figure 2–3. Borehole geophysical logs for well BK-3044, Fischer and Porter Superfund Site, Warminster Township, Bucks County, Pennsylvania, July 16, 2008. 

DEPTH, IN FEET BELOW LAND SURFACE

0

50

100150200250300350400

7 8 9 10 11 12 0 100 200 300 100 200 300 400 500 600 12 13 14 400 500 600

CALIPER LOG

HOLE DIAMETER,

IN INCHES

NATURAL GAMMA,

IN COUNTS PER

SECOND

SINGLE POINT

RESISTANCE,

IN OHMS

FLUID

TEMPERATURE, IN

DEGREES CELSIUS

FLUID RESISTIVITY,

IN OHM-METERS
104 Changes in Groundwater Flow and Volatile Organic Compound Concentrations, Fischer and Porter Superfund SiteFigure 2–4. Borehole geophysical logs for well BK-3045, Fischer and Porter Superfund Site, Warminster Township, Bucks County, Pennsylvania, July 17, 2008.

DEPTH, IN FEET BELOW LAND SURFACE

0

50

100150200250300350

7 8 9 10 11 0 100 200 200 400 600 800 12 13 14 200 400 600 800 1,000

CALIPER LOG

HOLE DIAMETER,

IN INCHES

NATURAL GAMMA,

IN COUNTS PER

SECOND

SINGLE POINT

RESISTANCE,

IN OHMS

FLUID

TEMPERATURE,

IN DEGREES CELSIUS

FLUID RESISTIVITY,

IN OHM-METERS
Appendix 2. Borehole Geophysical Logs 105 Figure 2–5. Borehole geophysical logs for well BK-3046, Fischer and Porter Superfund Site, Warminster Township, Bucks County, Pennsylvania, July 17, 2008.

DEPTH, IN FEET BELOW LAND SURFACE

0

50

100150

200250300350400

7 8 9 10 0 100 200 300 400 600 800 12.0 12.5 13.0 400 500 600

CALIPER LOG

HOLE DIAMETER,

IN INCHES

NATURAL GAMMA,

IN COUNTS PER

SECOND

SINGLE POINT

RESISTANCE,

IN OHMS

FLUID

TEMPERATURE,

IN DEGREES CELSIUS

FLUID RESISTIVITY,

IN OHM-METERS
106 Changes in Groundwater Flow and Volatile Organic Compound Concentrations, Fischer and Porter Superfund Site

Figure 2–6. Heatpulse-flowmeter measurements for well BK-3042, Fischer and Porter Superfund Site, Warminster Township, Bucks 

County, Pennsylvania, July 17, 2008.

 HOLE DIAMETER, IN INCHES

DEPTH, IN FEET BELOW LAND SURFACE

0

50

100

150

200

250

300

6 8 10 12

1.0

2.6E

3.0

1.0

1.7E

1.6E

1.5E

1.6E

0.4E

1.7E

1.0

EXPLANATION

BOREHOLE-FLOW MEASUREMENT UNDER

NONPUMPING CONDITIONS – Circle at depth

of flow measurement. Number is measured flow

in gallons per minute. 

DIRECTION OF VERTICAL BOREHOLE FLOW –

Upward arrow indicates upward flow; downward

arrow indicates downward flow.

FLOW INTO BOREHOLE – Arrow pointing away

from caliper log indicates flow into borehole. 

FLOW OUT OF BOREHOLE – Arrow pointing 

towards caliper log indicates flow out of borehole. 

2.6E ESTIMATED BOREHOLE-FLOW MEASUREMENT 

UNDER NONPUMPING CONDITIONS – Circle at 

depth of flow measurement. Number is estimated

flow in gallons per minute. 
Appendix 2. Borehole Geophysical Logs 107

Figure 2–7. Heatpulse-flowmeter measurements for well BK-3043, Fischer and Porter Superfund Site, Warminster Township, 

Bucks County, Pennsylvania, July 15, 2008. 

 HOLE DIAMETER, IN INCHES

DEPTH, IN FEET BELOW LAND SURFACE

0

50

100

150

200

250

300

350

4 6 8 10 12

EXPLANATION

BOREHOLE-FLOW MEASUREMENT UNDER

NONPUMPING CONDITIONS – Circle at depth

of flow measurement. Rate of flow greater than 

upper limit of instrument.

DIRECTION OF VERTICAL BOREHOLE FLOW –

Upward arrow indicates upward flow.

FLOW INTO BOREHOLE – Arrow pointing away

from caliper log indicates flow into borehole. Flow 

inferred from fluid-temperature and fluid-resistivity

geophysical logs.

FLOW OUT OF BOREHOLE – Arrow pointing 

towards caliper log indicates flow out of borehole. 

Flow inferred from fluid-temperature and fluidresistivity geophysical logs.
108 Changes in Groundwater Flow and Volatile Organic Compound Concentrations, Fischer and Porter Superfund Site

Figure 2–8. Heatpulse-flowmeter measurements for well BK-3044, Fischer and Porter Superfund Site, Warminster Township, 

Bucks County, Pennsylvania, July 16, 2008.

 HOLE DIAMETER, IN INCHES

DEPTH, IN FEET BELOW LAND SURFACE

0.07

EXPLANATION

BOREHOLE-FLOW MEASUREMENT UNDER

NONPUMPING CONDITIONS – Circle at depth

of flow measurement. Number is measured flow

in gallon per minute. <, less than. 

FLOW INTO BOREHOLE – Arrow pointing away

from caliper log indicates flow into borehole. 

FLOW OUT OF BOREHOLE – Arrow pointing 

towards caliper log indicates flow out of borehole. 

0

50

100

150

200

250

300

350

400

4 6 8 10 12

0.07

0.03

0.03

0.03

0

0

0

<0.02

<0.02

DIRECTION OF VERTICAL BOREHOLE FLOW –

Upward arrow indicates upward flow.
Appendix 2. Borehole Geophysical Logs 109

Figure 2–9. Heatpulse-flowmeter measurements for well BK-3045, Fischer and Porter Superfund Site, Warminster Township, Bucks 

County, Pennsylvania, July 17, 2008. 

 HOLE DIAMETER, IN INCHES

0.6

EXPLANATION

BOREHOLE-FLOW MEASUREMENT UNDER

NONPUMPING CONDITIONS – Circle at depth

of flow measurement. Number is measured flow

in gallon per minute. 

FLOW INTO BOREHOLE – Arrow pointing away

from caliper log indicates flow into borehole.

FLOW OUT OF BOREHOLE – Arrow pointing 

towards caliper log indicates flow out of borehole. 

2.1E ESTIMATED BOREHOLE-FLOW MEASUREMENT 

UNDER NONPUMPING CONDITIONS – Circle at 

depth of flow measurement. Number is estimated

flow in gallons per minute. 

DIRECTION OF VERTICAL BOREHOLE FLOW –

Upward arrow indicates upward flow.

0

50

100

150

200

250

300

350

4 6 8 10 12

2.2E

0.6

DEPTH, IN FEET BELOW LAND SURFACE

1.9E

2.1E

1.2E

1.2E

0.4E

0.3E

0.3E

0.2E

0.2E

0.3E
110 Changes in Groundwater Flow and Volatile Organic Compound Concentrations, Fischer and Porter Superfund Site

Figure 2–10. Heatpulse-flowmeter measurements for well BK-3046, Fischer and Porter Superfund Site, Warminster Township, 

Bucks County, Pennsylvania, July 17, 2008. 

 HOLE DIAMETER, IN INCHES

EXPLANATION

DIRECTION OF VERTICAL BOREHOLE FLOW –

Upward arrow indicates upward flow; downward

arrow indicates downward flow.

FLOW INTO BOREHOLE – Arrow pointing away

from caliper log indicates flow into borehole. 

FLOW OUT OF BOREHOLE – Arrow pointing 

towards caliper log indicates flow out of borehole. 

2.6E ESTIMATED BOREHOLE-FLOW MEASUREMENT 

UNDER NONPUMPING CONDITIONS – Circle at 

depth of flow measurement. Number is estimated

flow in gallons per minute. 

0

50

100

150

200

250

300

350

400

5 6 7 8 9 10

DEPTH, IN FEET BELOW LAND SURFACE

1.5E

1.5E

3.9E

4.7E

5.9E

5.6E

6.2E

6.7E

7.0E

6.6E

2.3E

2.4E

0.8E

0.2E
Appendix 3. Summary of Aquifer-Isolation Tests 111

Figure 3–1. Aquifer-isolation test results for well BK-3042, Fischer and Porter Superfund Site, Warminster Township, Bucks County, 

Pennsylvania, July 29–30, 2008. 

[<, less than; –, no data, only one packer inflated]

ZONE 1

ZONE 2

ZONE 3

ZONE 4

TRICHLOROETHYLENE

(micrograms

per liter)

4.5

6.6

10

12

PUMPING RATE

(gallons per

minute)

11

<1

4.9

4.6

SPECIFIC

CAPACITY

(gallons per

minute per foot)

4.3

NOT

DETERMINED

18.8

3.6

 HOLE DIAMETER, IN INCHES

DEPTH, IN FEET BELOW LAND SURFACE

0

50

100

150

200

250

300

8 10 12

IN

ISOLATED

ZONE

2.55

171

0.26

1.27

ABOVE

ISOLATED

ZONE

–

0.05

0.40

0.19

BELOW

ISOLATED

ZONE

0.12

0.01

–

0.19

DRAWDOWN (feet) . 

Appendix 3. Summary of Aquifer-Isolation Tests
112 Changes in Groundwater Flow and Volatile Organic Compound Concentrations, Fischer and Porter Superfund Site

Figure 3–2. Aquifer-isolation test results for well BK-3043, Fischer and Porter Superfund Site, Warminster Township, Bucks County, 

Pennsylvania, July 22–24, 2008. A negative drawdown indicates a rise in water level during the test.

[–, no data, only one packer inflated]

0

50

100

150

200

250

300

350

6 8 10 12

ZONE 1

ZONE 2

HOLE DIAMETER, IN INCHES

DEPTH, IN FEET BELOW LAND SURFACE

ZONE 3

ZONE 4

ZONE 5

ZONE 6

8.9

4.1

4.6

4.6

3.7

4.1

25

24

27

10

4.2

6.9

16

84

91

77

40

68

TRICHLOROETHYLENE

(micrograms

per liter)

PUMPING RATE

(gallons per

minute)

SPECIFIC

CAPACITY

(gallons per

minute per foot)

IN

ISOLATED

ZONE

ABOVE

ISOLATED

ZONE

BELOW

ISOLATED

ZONE

0.35

0.54

0.19

0.17

0.40

0.97

–

0.08

0.09

0.05

0.22

0.11

-0.08

0.13

–

0.03

-0.16

-0.09

DRAWDOWN (feet) . 
Appendix 3. Summary of Aquifer-Isolation Tests 113

Figure 3–3. Aquifer-isolation test results for well BK-3044, Fischer and Porter Superfund Site, Warminster Township, Bucks County, 

Pennsylvania, July 25–28, 2008. A negative drawdown indicates a rise in water level during the test. 

[<, less than; –, no data]

0

50

100

150

200

250

300

350

400

7 8 9 10 11 12

ZONE 1

ZONE 2

ZONE 4

ZONE 3

3.3

<0.5

NO SAMPLE

<0.5

11.3

4.1

<0.5

4.6

1.1

NOT DETERMINED

1.1

1.0

HOLE DIAMETER, IN INCHES

DEPTH, IN FEET BELOW LAND SURFACE

TRICHLOROETHYLENE

(micrograms

per liter)

PUMPING RATE

(gallons per

minute)

SPECIFIC

CAPACITY

(gallons per

minute per foot)

IN

ISOLATED

ZONE

ABOVE

ISOLATED

ZONE

BELOW

ISOLATED

ZONE

10.37

4.12

–

4.10

–

0.13

–

1.92

-0.12

3.25

–

1.86

DRAWDOWN (feet) . 
114 Changes in Groundwater Flow and Volatile Organic Compound Concentrations, Fischer and Porter Superfund Site

Figure 3–4. Aquifer-isolation test results for well BK-3045, Fischer and Porter Superfund Site, Warminster Township, Bucks County, 

Pennsylvania, August 13–15, 2008. A negative drawdown indicates a rise in water level during the test. 

[<, less than; –, no data]

HOLE DIAMETER, IN INCHES

DEPTH, IN FEET BELOW LAND SURFACE

ZONE 1

0

50

100

150

200

250

300

350

6 8 10 12

ZONE 2

ZONE 3

ZONE 5

ZONE 4

ZONE 6

34.1

27.1

21.2

NO SAMPLE

85.5

44.3

10.5

3.5

2.2

<0.5

2.0

4.1

2.6

0.39

0.02

NOT DETERMINED

0.04

0.08

TRICHLOROETHYLENE

(micrograms

per liter)

PUMPING RATE

(gallons per

minute)

SPECIFIC

CAPACITY

(gallons per

minute per foot)

IN

ISOLATED

ZONE

ABOVE

ISOLATED

ZONE

BELOW

ISOLATED

ZONE

4.04

9.08

123.91

–

55.81

51.20

–

1.06

0.82

–

0.21

0.58

0.45

-0.17

-0.47

–

1.03

–

DRAWDOWN (feet) . 
Appendix 3. Summary of Aquifer-Isolation Tests 115

Figure 3–5. Aquifer-isolation test results for well BK-3046, Fischer and Porter Superfund Site, Warminster Township, Bucks County, 

Pennsylvania, July 31 and August 1, 2008. A negative drawdown indicates a rise in water level during the test. 

[<, less than; –, no data]

0

50

100

150

200

250

300

350

400

7 8 9 10

HOLE DIAMETER, IN INCHES

DEPTH, IN FEET BELOW LAND SURFACE

ZONE 1

ZONE 2

ZONE 3

ZONE 4

ZONE 5

NO SAMPLE

<0.5

<0.5

<0.5

<0.5

5.0

<0.5

3.0

3.6

4.0

0.99

NOT DETERMINED

0.18

0.15

0.17

TRICHLOROETHYLENE

(micrograms

per liter)

PUMPING RATE

(gallons per

minute)

SPECIFIC

CAPACITY

(gallons per

minute per foot)

IN

ISOLATED

ZONE

ABOVE

ISOLATED

ZONE

BELOW

ISOLATED

ZONE

5.07

–

16.61

23.95

23.17

–

–

-0.81

2.18

4.13

1

4.99

–

10.44

11.53

–

1

Drawdown caused by declining head after packer inflation 

 and not related to pumping.

DRAWDOWN (feet) . 

Prepared by the West Trenton Publishing Service Center.

For more information concerning this report, contact:

Director

U.S. Geological Survey

Pennsylvania Water Science Center

215 Limekiln Road

New Cumberland, PA 17070

dc_pa@usgs.gov

or visit our Web site at:

http://pa.water.usgs.gov
Sloto—Changes in Groundwater Flow and Volatile Organic Compound Concentrations, Fischer and Porter Superfund Site, 1993–2009—SIR 2010–5054