U.S. Department of the Interior

U.S. Geological Survey

Scientific Investigations Report 2010–5261

Prepared in cooperation with the 

Pennsylvania Department of Environmental Protection, 

Eastern Pennsylvania Coalition for Abandoned Mine Reclamation, and 

Dauphin County Conservation District

Water Budgets and Groundwater Volumes for Abandoned 

Underground Mines in the Western Middle Anthracite 

Coalfield, Schuylkill, Columbia, and Northumberland 

Counties, Pennsylvania—Preliminary Estimates with 

Identification of Data Needs
Cover. Details of figures 9, 16, and 17 showing features of the groundwater-flow model used to determine water budgets and 

groundwater volumes.
Water Budgets and Groundwater Volumes 

for Abandoned Underground Mines in 

the Western Middle Anthracite Coalfield, 

Schuylkill, Columbia, and Northumberland 

Counties, Pennsylvania—Preliminary 

Estimates with Identification of Data Needs

By Daniel J. Goode, Charles A. Cravotta III, Roger J. Hornberger, 

Michael A. Hewitt, Robert E. Hughes, Daniel J. Koury,and Lee W. Eicholtz

Prepared in cooperation with the

Pennsylvania Department of Environmental Protection, 

Eastern Pennsylvania Coalition for Abandoned Mine Reclamation, and 

Dauphin County Conservation District

Scientific Investigations Report 2010–5261

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: 2011

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reproduce any copyrighted materials contained within this report.

Suggested citation:

Goode, D.J., Cravotta, C.A., III, Hornberger, R.J., Hewitt, M.A., Hughes, R.E., Koury., D.J., and Eicholtz, L.W., 2011, 

Water budgets and groundwater volumes for abandoned underground mines in the Western Middle Anthracite Coalfield, Schuylkill, Columbia, and Northumberland Counties, Pennsylvania—Preliminary estimates with identification of 

data needs: U.S. Geological Survey Scientific Investigations Report 2010–5261, 54 p.
iii

Contents

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

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

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

Previous Investigations........................................................................................................................2

Hydrogeologic Setting .........................................................................................................................4

Streamflow and Groundwater Relations ...................................................................................................9

Streamflow and Mine-Discharge Data .............................................................................................9

Mine-Pool Water-Level Data ............................................................................................................16

Multicolliery Unit Concept.................................................................................................................16

Simulated Water Budgets and Effects of Pumping Changes ...............................................................22

Conceptual Model...............................................................................................................................22

Model Development ...........................................................................................................................22

Computer Code and Grid ..........................................................................................................22

Boundary Conditions.................................................................................................................25

Recharge from Precipitation...........................................................................................25

Streams...............................................................................................................................25

Coal Mines .........................................................................................................................25

Wells ................................................................................................................................25

Aquifer Properties .....................................................................................................................27

Model Adjustments.............................................................................................................................27

Weighting of Measurements ...................................................................................................27

Adjusted Model Parameters....................................................................................................27

Preliminary Results of Model Simulations......................................................................................31

Current Conditions.....................................................................................................................31

Increased Pumping in Gilberton Area ...................................................................................35

Example of Additional Model Adjustments ...........................................................................35

Limitations of the Preliminary Model Results ................................................................................38

Estimated Groundwater Volume and Distribution ..................................................................................38

Uncertainty in Estimates of Mine-Pool Volume ............................................................................39

Alternative Method for Determining Volume ................................................................................42

Identification of Data Needs .....................................................................................................................42

Summary........................................................................................................................................................44

References Cited..........................................................................................................................................45
iv

Figures

1–2. Maps showing—

1. Surface drainage, selected municipalities, and study-area boundary within

Schuylkill, Columbia, and Northumberland Counties, Pennsylvania ..........................3

2. Principal bedrock units and sites within Shamokin and Mahanoy Creek Basins,

Schuylkill, Columbia, and Northumberland Counties, Pennsylvania, where 

mine discharges and streamflow were measured by the U.S. Geological Survey 

in 1999–2001..........................................................................................................................5

3. Cross sections showing structural geology of the Western Middle Anthracite 

Coalfield, Schuylkill, Columbia, and Northumberland Counties, Pennsylvania..................6

4. Map showing simplified structural contours of the Buck Mountain coalbed used to 

develop the groundwater-flow model of the Western Middle Anthracite Coalfield, 

Schuylkill, Columbia, and Northumberland Counties, Pennsylvania ...................................7

5. Graph showing total annual precipitation during 1941 to 2008 for Mahanoy City and 

Tamaqua, Pennsylvania.............................................................................................................10

6–9. Maps showing—

6. Estimated streamflow yields of surface drainage sub-basins within Shamokin

and Mahanoy Creek Basins, Schuylkill, Columbia, and Northumberland 

Counties, Pennsylvania, 1999–2001 ................................................................................12

7. Approximate locations of principal collieries, barrier pillars, and tunnels 

within the Western Middle Anthracite Coalfield, Schuylkill, Columbia, and 

Northumberland Counties, Pennsylvania......................................................................13

8. Conceptual multicolliery hydrogeologic units and locations of associated

groundwater-level, mine-discharge, and streamflow data used to develop the

groundwater-flow model of the Western Middle Anthracite Coalfield, Schuylkill,

Columbia, and Northumberland Counties, Pennsylvania............................................19

9. Finite-difference grid and location of mined area, stream cells, and pumpingwell cells for the groundwater-flow model of the Western Middle Anthracite 

Coalfield, Schuylkill, Columbia, and Northumberland Counties, Pennsylvania.......23

10. Cross sections of finite-difference grid along (A) row 36 and (B) column 170 for the

groundwater-flow model of the Western Middle Anthracite Coalfield, Schuylkill,

Columbia, and Northumberland Counties, Pennsylvania.....................................................25

11–12. Maps showing—

11. Altitude of the bottom of model layer 3 for the groundwater-flow model of 

the Western Middle Anthracite Coalfield, Schuylkill, Columbia, 

and Northumberland Counties, Pennsylvania ..............................................................26

12. Locations of high- and low-permeability barriers between mines for the

groundwater-flow model of the Western Middle Anthracite Coalfield, 

Schuylkill, Columbia, and Northumberland Counties, Pennsylvania ........................28

13. Bar graph showing composite scaled sensitivity of hydraulic parameters used in the

groundwater-flow model of the Western Middle Anthracite Coalfield, Schuylkill,

Columbia, and Northumberland Counties, Pennsylvania.....................................................29
v

14–15. Plots showing—

14. Relation between observed and simulated groundwater levels simulated by 

use of the groundwater-flow model of the Western Middle Anthracite Coalfield, 

Schuylkill, Columbia, and Northumberland Counties, Pennsylvania ........................30

15. Relation between observed and simulated base-flow gain or loss 

simulated by use of the groundwater-flow model of the Western Middle 

Anthracite Coalfield, Schuylkill, Columbia, and Northumberland Counties, 

Pennsylvania ......................................................................................................................30

16–19. Maps showing—

16. Water-table altitude for current conditions simulated by use of the groundwaterflow model of the Western Middle Anthracite Coalfield, Schuylkill, Columbia, 

and Northumberland Counties, Pennsylvania ..............................................................32

17. Areas contributing precipitation recharge to mine discharges, pumping wells, 

and streams for current conditions simulated by use of the groundwater-flow 

model of the Western Middle Anthracite Coalfield, Schuylkill, Columbia, and

Northumberland Counties, Pennsylvania......................................................................33

18. Rate of volumetric recharge from streams for current conditions simulated by 

use of the groundwater-flow model of the Western Middle Anthracite

Coalfield, Schuylkill, Columbia, and Northumberland Counties, Pennsylvania.......34

19. Regional steady-state drawdown in layer 3 with increased pumping of minepool water in the Gilberton area and areas contributing recharge from 

precipitation to different discharges simulated by use of the groundwater-flow 

model of the Western Middle Anthracite Coalfield, Schuylkill, Columbia, and 

Northumberland Counties, Pennsylvania......................................................................36

20–21. Screen captures showing—

20. Modifications to mine-barrier hydraulic conductivity for alternative 

groundwater-flow model for the Western Middle Anthracite Coalfield, 

Schuylkill, Columbia, and Northumberland Counties, Pennsylvania ........................37

21. Generalized dip angles for use in estimating mine-pool volumes using a

hydrogeologic model for the Western Middle Anthracite Coalfield, Schuylkill,

Columbia, and Northumberland Counties, Pennsylvania............................................41

22. Schematic cross section of flooded mine complex showing the groundwater table

in overlying, mined coalbeds and the portion of the surface area of the mined

coalbed where water-table storage capacity is effective...................................................43
vi

Tables

1. Average thicknesses and relative altitudes of economically important coalbeds 

above the Buck Mountain coalbed in the Western Middle Anthracite Coalfield in 

eastern Pennsylvania...................................................................................................................8

2. Site descriptions and estimated streamflow yields for surface drainage sub-basins 

within Shamokin and Mahanoy Creek Basins, Schuylkill, Columbia, and 

Northumberland Counties, Pennsylvania, 1999–2001...........................................................11

3. Site descriptions and flow rates of abandoned mine discharges in the Western 

Middle Anthracite Coalfield, Schuylkill, Columbia, and Northumberland Counties, 

Pennsylvania, 1999–2001 ...........................................................................................................50

4. Name, year of closure, estimated area, and altitude of deepest mining of collieries 

in the Western Middle Anthracite Coalfield, Schuylkill, Columbia, 

and Northumberland Counties, Pennsylvania .......................................................................17

5. Locations of boreholes and altitudes of groundwater used to estimate volume 

of water stored in underground mines and to adjust the groundwater-flow model 

of the Western Middle Anthracite Coalfield, Schuylkill, Northumberland, 

and Columbia Counties, Pennsylvania ....................................................................................53

6. Names, areas, estimated discharge, and measured discharge from multicolliery 

hydrologic units in the Western Middle Anthracite Coalfield in eastern 

Pennsylvania ...............................................................................................................................18

7. Parameters used in the groundwater-flow model of Western Middle Anthracite 

Coalfield, Schuylkill, Columbia, and Northumberland Counties, Pennsylvania................29

8. Water budget for current conditions simulated by use of the groundwater-flow 

model of the Western Middle Anthracite Coalfield, Schuylkill, Columbia, 

and Northumberland Counties, Pennsylvania .......................................................................31

9. Water budget for increased pumping from mine pool in Gilberton area simulated 

by use of the groundwater-flow model of the Western Middle Anthracite Coalfield, 

Schuylkill, Columbia, and Northumberland Counties, Pennsylvania .................................37

10. Estimated storage volumes and discharges of groundwater by flooded underground 

mines in the Western Middle Anthracite Coalfield, Schuylkill, Northumberland, and 

Columbia Counties, Pennsylvania............................................................................................40

11. Estimated storage volumes and average residence times of groundwater in the 

mine pools considering different porosities for mined coalbeds in the Western 

Middle Anthracite Coalfield, Schuylkill, Northumberland, and Columbia Counties, 

Pennsylvania, 1999–2001 ...........................................................................................................41
vii

Conversion Factors and Datums

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

square mile (mi2) 2.590 square kilometer (km2) 

Volume

gallon (gal) 0.003785 cubic meter (m3) 

gallon (gal) 3.785 cubic decimeter (dm3) 

million gallons (Mgal) 3,785 cubic meter (m3)

billion gallons (Bgal) 3,785,000 cubic meter (m3)

cubic foot (ft3) 0.02832 cubic meter (m3) 

acre-foot (acre-ft) 1,233 cubic meter (m3)

Flow rate

cubic foot per second (ft3/s) 0.02832 cubic meter per second (m3/s)

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

gallon per day (gal/d) 3.785 liter per day (L/d)

million gallons per day (Mgal/d) 0.04381 cubic meter per second (m3/s)

inch per year (in/yr) 2.54 centimeter per year (cm/yr)

mile per hour (mi/h) 1.609 kilometer per hour (km/h) 

Hydraulic conductivity

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

Vertical coordinate information is referenced to the National Geodetic Vertical Datum of 1929 

(NGVD 29).

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.
(This page intentionally left blank.)
Water Budgets and Groundwater Volumes for Abandoned 

Underground Mines in the Western Middle Anthracite 

Coalfield, Schuylkill, Columbia, and Northumberland 

Counties, Pennsylvania—Preliminary Estimates with 

Identification of Data Needs 

Daniel J. Goode1, Charles A. Cravotta III1, Roger J. Hornberger2, Michael A. Hewitt3, Robert E. Hughes3, 

Daniel J. Koury4,and Lee W. Eicholtz1

Abstract

This report, prepared in cooperation with the Pennsylvania Department of Environmental Protection (PaDEP), the 

Eastern Pennsylvania Coalition for Abandoned Mine Reclamation, and the Dauphin County Conservation District, provides 

estimates of water budgets and groundwater volumes stored in 

abandoned underground mines in the Western Middle Anthracite Coalfield, which encompasses an area of 120 square miles 

in eastern Pennsylvania. The estimates are based on preliminary simulations using a groundwater-flow model and an 

associated geographic information system that integrates data 

on the mining features, hydrogeology, and streamflow in the 

study area. The Mahanoy and Shamokin Creek Basins were 

the focus of the study because these basins exhibit extensive 

hydrologic effects and water-quality degradation from the 

abandoned mines in their headwaters in the Western Middle 

Anthracite Coalfield. Proposed groundwater withdrawals from 

the flooded parts of the mines and stream-channel modifications in selected areas have the potential for altering the 

distribution of groundwater and the interaction between the 

groundwater and streams in the area.

Preliminary three-dimensional, steady-state simulations 

of groundwater flow by the use of MODFLOW are presented 

to summarize information on the exchange of groundwater 

among adjacent mines and to help guide the management of 

ongoing data collection, reclamation activities, and water-use 

planning. The conceptual model includes high-permeability 

mine voids that are connected vertically and horizontally 

1 USGS Pennsylvania Water Science Center.

2 Independent consultant (deceased).

3 Eastern Pennsylvania Coalition for Abandoned Mine Reclamation.

4 Pennsylvania Department of Environmental Protection.

within multicolliery units (MCUs). MCUs were identified 

on the basis of mine maps, locations of mine discharges, and 

groundwater levels in the mines measured by PaDEP. The 

locations and integrity of mine barriers were determined 

from mine maps and groundwater levels. The permeability of 

intact barriers is low, reflecting the hydraulic characteristics of 

unmined host rock and coal. 

A steady-state model was calibrated to measured groundwater levels and stream base flow, the latter at many locations 

composed primarily of discharge from mines. Automatic 

parameter estimation used MODFLOW-2000 with manual 

adjustments to constrain parameter values to realistic ranges. 

The calibrated model supports the conceptual model of highpermeability MCUs separated by low-permeability barriers 

and streamflow losses and gains associated with mine infiltration and discharge. The simulated groundwater levels illustrate 

low groundwater gradients within an MCU and abrupt changes 

in water levels between MCUs. The preliminary model results 

indicate that the primary result of increased pumping from the 

mine would be reduced discharge from the mine to streams 

near the pumping wells. The intact barriers limit the spatial 

extent of mine dewatering. Considering the simulated groundwater levels, depth of mining, and assumed bulk porosity of 11 

or 40 percent for the mined seams, the water volume in storage 

in the mines of the Western Middle Anthracite Coalfield was 

estimated to range from 60 to 220 billion gallons, respectively. 

Details of the groundwater-level distribution and the 

rates of some mine discharges are not simulated well using the 

preliminary model. Use of the model results should be limited 

to evaluation of the conceptual model and its simulation using 

porous-media flow methods, overall water budgets for the 

Western Middle Anthracite Coalfield, and approximate storage 

volumes. Model results should not be considered accurate for 

detailed simulation of flow within a single MCU or individual 

flooded mine. Although improvements in the model calibration 

were possible by introducing spatial variability in permeability 
2 Water budgets and groundwater volumes for abandoned mines in the Western Middle Anthracite Coalfield, Pa

parameters and adjusting barrier properties, more detailed 

parameterizations have increased uncertainty because of the 

limited data set. 

The preliminary identification of data needs includes 

continuous streamflow, mine discharge rate, and groundwater 

levels in the mines and adjacent areas. Data collected when the 

system is responding to hydrologic stresses such as recharge 

or pumping changes would provide information on hydraulic 

barrier integrity and groundwater/surface-water exchanges; the 

latter would also be informed by tracer studies and streambed 

surveys. Use of transient simulations, calibrated with transient 

measurements, is suggested to provide an independent estimate of the storage capacity of the mines.

Introduction

Although once a scene of vital coal-mining activity, 

landscapes containing legacy anthracite mines in eastern 

Pennsylvania presently are among the most disturbed and economically depressed in the northeastern United States. Once 

thriving towns such as Mahanoy City, Gilberton, Centralia, 

Ashland, Shamokin, and Trevorton in the Western Middle 

Anthracite Coalfield of Schuylkill, Columbia, and Northumberland Counties (fig. 1) have declined in population by half 

or more since 1920 (Marsh, 1987). The extensively mined 

areas surrounding the towns are characterized by eroded 

mounds of thinly vegetated waste coal and rock, abandoned 

open pits, cropfalls and other subsidence features, intermittent 

(losing) streambeds downstream of perennial streams, and 

discharges of contaminated groundwater from flooded mines. 

Resource and business managers recognize that economic 

revitalization of the region will require environmental restoration and access to land and water resources (21st Century 

Environment Commission, 1998). Although Shamokin Creek, 

Mahanoy Creek, and most other parts of the study area drain 

to the Susquehanna River, an area along the southeast boundary drains to the Schuylkill River (fig. 1). Water in these river 

basins is in great demand. Extensive, flooded underground 

mines have been identified as potential sources of large 

volumes of water needed for proposed energy-production 

facilities and other commercial uses (Veil and others, 2003). 

However, widespread usage of the mine water could affect 

streamflow and aquatic ecosystems of the basins that drain the 

coalfield. Therefore, groundwater modeling was proposed as a 

method for estimating present groundwater and surface-water 

interactions and for evaluating potential effects of large-scale 

water extraction and land-reclamation activities in the area.

This study, conducted by the U.S. Geological Survey 

(USGS) in cooperation with the Pennsylvania Department of 

Environmental Protection (PaDEP), the Eastern Pennsylvania 

Coalition for Abandoned Mine Reclamation (EPCAMR), and 

the Dauphin County Conservation District (DCCD), provides 

estimates of the water budgets and the volumes of groundwater in the abandoned underground mines of the Western 

Middle Anthracite Coalfield. The study utilized available geographic, geologic, and hydrologic information to develop conceptual and numerical groundwater-flow models to describe 

the hydrologic framework for the mines. The Western Middle 

Anthracite Coalfield was studied because data were available on the locations, volumes, and quality of groundwater 

discharged from the underground mines; the streamflow and 

aquatic quality of affected streams; the depth to groundwater 

within the flooded mines; and the depth of mining. Proposed 

large-volume withdrawals of water from the underground 

mines and potential for decreased infiltration from proposed 

stream-channel modifications could affect the volumes and 

quality of water in the streams and discharged by the mines. 

Purpose and Scope

This report describes data on the distribution and flow of 

surface water and groundwater and summarizes the results of 

computations of the water budgets and volumes for flooded 

underground mines on the basis of preliminary simulations 

of groundwater flow for the Western Middle Anthracite 

Coalfield. The report describes the study area, model construction, selected data used to adjust hydrologic parameters, 

and simulations of water budgets and groundwater/surfacewater interactions. Preliminary simulations are presented for 

(1) present conditions and (2) a water table lowered by pumping operations associated with thermoelectric power production. The purpose of reporting on the results of preliminary 

simulations is to evaluate the conceptual model and use of 

porous-media-flow approximations and to help guide ongoing 

data collection, reclamation strategies, and post-mining landuse and water-use planning for the Mahanoy and Shamokin 

Creek Basins. The preliminary simulations may be revised as 

additional details on the area hydrology become available.

Previous Investigations

Historical summaries of the surface-water and groundwater resources of the Western Middle Anthracite Coalfield study 

area are found in reports by Ash and others (1949, 1953a, 

1953b) and Ash and Link (1953). These reports describe the 

hydrological conditions during a critical period after World 

War II when several large underground mines were actively 

pumping large volumes of groundwater to avoid flooding 

and remain productive. Reed and others (1987) described the 

water resources of the study area for the post-mining, stable 

groundwater conditions during the mid-1970s. Growitz and 

others (1985), Wood (1996), Cravotta and Kirby (2004), 

and Cravotta (2005) described the flow and water quality of 

abandoned mine discharges (AMD) and associated streams 

in the Mahanoy and Shamokin Creek drainage basins for the 

post-mining conditions. Becher (1991) evaluated the longterm streamflow characteristics of Shamokin Creek near 

Shamokin, which was influenced by sustained discharges of 

AMD, and of nearby streams that were not affected by mining. 
Introduction 

3

Study area

76°10' 76°20' 76°30' 76°40' 76°50'

40°50'40°40'

0 5 MILES0 5 KILOMETERS

PENNSYLVANIA EXPLANATION

Streams from U.S. Geological Survey National Hydrography Data Set, 2009, 1:100,000Shaded relief prepared from U.S. Geological Survey National Elevation Data Set, 2004

SCHUYLKILL RIVER DRAINAGE

STREAMPOPULATION CENTER

Catawissa CreekMahanoy CreekMahantango CreekRoaring CreekShamokin CreekSchuykill River

SUSQUEHANNA RIVER DRAINAGE COUNTY BOUNDARY

STUDY-AREA BOUNDARY

Ashland

Sunbury

Shamokin

Trevorton

Gilberton

Pottsville

Mount Carmel

Mahanoy City

Ashland

Sunbury

Shamokin

Trevorton

Gilberton

Pottsville

Mount Carmel

Mahanoy City

SCHUYLKILL

COUNTY

NORTHUMBERLAND

COUNTY

LUZERNE

COUNTY

SNYDER

COUNTY

MONTOUR

COUNTY

UNION

COUNTY

COLUMBIA

COUNTY

SCHUYLKILL

COUNTY

NORTHUMBERLAND

COUNTY

LUZERNE

COUNTY

SNYDER

COUNTY

MONTOUR

COUNTY

UNION

COUNTY

COLUMBIA

COUNTY

DAUPHIN COUNTY

Centralia uS qs

eu hanna

vi R

re

Centralia uS qs

eu hanna

vi R

re

Figure 1. Surface drainage, selected municipalities, and study-area boundary within Schuylkill, Columbia, and Northumberland Counties, Pennsylvania.
4 Water budgets and groundwater volumes for abandoned mines in the Western Middle Anthracite Coalfield, Pa

The annual base-flow yield estimates of Becher (1991) and 

additional computations by Risser and others (2005) generally 

can be interpreted to indicate annual groundwater recharge in 

the basin. 

Hydrogeologic Setting

The Western Middle Anthracite Coalfield covers an 

area of approximately 120 mi2 in the Appalachian Mountains 

section of the Ridge and Valley Physiographic Province of 

northeastern Pennsylvania (Berg and others, 1989; Eggleston 

and others, 1999). This area is characterized by northeastsouthwest trending ridges that bound narrow valleys (fig. 1). 

Because of their steep slopes and thin rocky soils, the ridges 

are sparsely developed and are largely forested. In contrast, the valleys are covered by extensive areas of barren or 

thinly vegetated “abandoned mine lands.” Although some 

small towns such as Centralia were developed near mines on 

uplands, the larger municipalities, such as Shamokin, Mount 

Carmel, Ashland, and Mahanoy City, were established in 

the valleys (fig. 1) near large mines, railheads, or water gaps 

(Marsh, 1987). 

Complexly folded and faulted coal-bearing sedimentary 

rocks underlie the study area. The Western Middle Anthracite 

Coalfield is a synclinal basin, or “canoe-shaped” structure, that 

has been subdivided by parallel faults into a series of parallel 

sub-basins (figs. 2, 3, and 4). Devonian and Mississippian age 

rocks are exposed along the ridges, whereas the coal-bearing 

Pennsylvanian age rocks are exposed on the valley sides and 

underlie the valleys (figs. 2 and 3) (Berg and others, 1980; 

Wood and others, 1986). In the study area, a total of 24 coalbeds within the Llewellyn and Pottsville Formations have been 

mined to depths exceeding 2,500 ft below land surface (Wood 

and others, 1986; Reed and others, 1987; Eggleston and 

others, 1999). The coalbeds, with average thicknesses from 

2.0 to 7.4 ft (table 1), are interbedded with shale, siltstone, 

sandstone, and conglomerate; limestone has not been mapped 

locally (Wood and others, 1986). 

From about 1840 until 1966, when the last underground 

mine (Maysville Mine) in the study area closed, an estimated 

1.6 billion short tons of anthracite had been mined from the 

coal basins in the Western Anthracite Middle Coalfield, leaving 3.6 to 3.9 billion short tons unmined (Reed and others, 

1987; Eggleston and others, 1999). Most of the coal was 

removed by underground-mining methods. On average, about 

20 percent of the mined coalbed consisted of shale partings, 

referred to as noncoal waste (table 1). Considering the quantities of coal and refuse, the total volume of mined rock was 

approximately 41 billion cubic feet. Reed and others (1987) 

estimated that 25 billion cubic feet of underground void volume was created, which, because of subsidence and backfilling, is approximately 60 percent of the total rock mined. This 

void volume is equivalent to excavating the entire 120-mi2

area of the Western Middle Anthracite Coalfield to a depth 

of 7.5 ft. A large fraction of this void volume has been filled 

by groundwater. 

Most anthracite mines were developed as large underground complexes or “collieries,” where shafts and tunnels 

connected multiple coalbeds underlying the valleys. The 

underground mining was conducted by the “room-and-pillar” 

or “breast-and-pillar” method, with about half of the coal left 

to support the roof during the first stage (Reed and others, 

1987; Eggleston and others, 1999). After a coalbed had been 

first mined, the pillars commonly were removed by retreat 

mining from near the mine boundary toward the mine shaft. 

Along the mine boundaries, unmined walls of coal, or “barrier 

pillars,” usually were left intact to prevent explosions and fires 

from affecting adjacent mines and to control flooding. The 

intact barrier pillars acted as underground dams, preventing 

the flow of groundwater from adjacent mines (Ash and others, 

1949; Reed and others, 1987). However, some barrier pillars 

had been partially mined or breached (Ash and others, 1953a). 

Groundwater in the study area is recharged by infiltration 

of local precipitation. Because direct runoff from the mined 

land can be intercepted by surface openings to the mines and 

because vegetation tends to be sparse in areas covered by mine 

waste, groundwater recharge generally is greater in mined 

areas than in unmined areas (Ash and Link, 1953; Becher, 

1991). According to Ash and Link (1953), approximately 

90 percent of the water in the underground mines (active and 

idle) originated as general surface seepage; the remaining 

10 percent originated as seepage through streambeds within 

the study area. 

When the underground mines were active, seepage water 

had to be removed to prevent flooding. If the mine workings 

were at a higher altitude than adjacent valley bottoms, water 

could be removed by drainage tunnels from the mines to the 

adjacent valleys. In the study area, the Doutyville Tunnel, 

Helfenstein Locust Gap Tunnel, and Centralia Mine Tunnel 

convey water from mines underlying the Shamokin Creek 

Basin to the adjacent Mahanoy Creek Basin (Reed and others, 

1987). However, many of the mines in the study area were 

800 to 1,000 ft below the valleys (Ash and others, 1949; Reed 

and others, 1987). Thus, pumping was required to dewater the 

deep workings of most mines. On average, 1,000 gal/min had 

to be pumped for each square mile of surface area underlain 

by mine workings (Ash and others, 1953b). All the large 

underground mines in the study area had closed by 1966, 

partly because of the cost of pumping (Reed and others, 1987). 

After closure, the underground workings below stream levels 

flooded producing “mine pools” and eventually established a 

new water table. 

When the underground mines were active, flumes were 

constructed to convey some streams across the mines, or the 

stream channels were lined, to reduce leakage and to reduce 

the costs of removing groundwater from the mines. Upon 

closure of the mines, neglected flumes and stream channels 

resumed leaking, and some streams were lost completely into 

open mine pits or other openings. Presently (2010), upper 

Mahanoy Creek, North Mahanoy Creek, Waste House Run, 

and Lost Creek in the Mahanoy Creek Basin and upper Shamokin Creek and Locust Creek in the Shamokin Creek Basin 
Introduction 

5

STUDY AREA

A

A’

B

B’

uS

qs

eu hanna

i R

ev r

CATAWISSA CREEK

BASIN ROARING CREEK

BASIN

MAHANTANGO CREEK

BASIN

SCHUYLKILL RIVER

BASIN

MAHANOY CREEK

BAS NI

SHAMOKIN

CREEK BASIN uS qs eu hanna

i R

ev r

CATAWISSA CREEK

BASIN ROARING CREEK

BASIN

MAHANTANGO CREEK

BASIN

SCHUYLKILL RIVER

BASIN

MAHANOY CREEK

BAS NI

SHAMOKIN

CREEK BASIN

EXPLANATION

MONITORING SITES

PRINCIPAL BEDROCK UNITS

PennsylvanianMississippianMississippian and DevonianDevonianDevonian and SilurianSilurian

STUDY-AREA BOUNDARYBASIN BOUNDARYLINE OF SECTION—Shown in figure 3STREAMStreamflowMine discharge

Streams from U.S. Geological Survey National Hydrography Data Set, 2009, 1:100,000Shaded relief prepared from U.S. Geological Survey, National Elevation Data Set, 2004

0 5 MILES0 5 KILOMETERS

PENNSYLVANIA

A A’

76°10' 76°20' 76°30' 76°40' 76°50'

40°50'40°40'

Principal bedrock units and sites within Shamokin and Mahanoy Creek Basins, Schuylkill, Columbia, and Northumberland Counties, Pennsylvania, where mine 

80). Lines of section indicate approximate 

Figure 2.discharges and streamflow were measured by the U.S. Geological Survey in 1999–2001. Geologic units are from Berg and others (19

B-B’ shown in figure 3. and locations of cross sections A-A’ 
6 Water budgets and groundwater volumes for abandoned mines in the Western Middle Anthracite Coalfield, Pa

Altitude, in feet above National Geodetic Vertical Datum of 1929

2,0001,5001,000

500

0

-500

-1,000

2,0001,5001,000

500

0

-500

-1,000

A A’

B B’

Bend in

section

Bend in

section

Bend in

section

Bend in

section

Kehleys Run Mine Kohinoor Mine West Shenandoah Mine Gilberton Mine Kehleys Run Mine Kohinoor Mine

Knickerbocker Mine North Mahanoy Mine Mahanoy City Mine Tunnel Ridge Mine

EXPLANATION

MINE WASTE—Includes such waste from mining and breaker operationsCOALBED AND COALBED NUMBER—Solid line designates mined section. Buck Mountain coalbed shown in red. Shading indicates mine fill-in pitsFAULT LINE—Arrows show relative movement.MINE GANGWAY

2

0 600 METERS

0 2,000 FEET

ored line is the Buck 

Structural geology of the Western Middle Anthracite Coalfield, Schuylkill, Columbia, and Northumberland Counties, Pennsylvania. Coalbed Figure 3.

number and name are listed in table 1. Solid lines indicate coal has been mined; dashed lines indicate coal is unmined. Red-col

agner (1955), and cross-section B-B’ was modified from Danilchik and others Mountain coalbed. Cross section A-A’ was modified from Kehn and W

(1955). 
Introduction 

7

STUDY AREA

76°10' 76°20' 76°30' 76°40' 76°50'

40°50'40°40'

2,000

1,000

0

0

500

-500

0 500

1,000

1,000

500 2,000

2,000

500

2,000

1,000

0

0

500

-500

0 500

1,000

1,000

500 2,000

2,000

500

0 5 MILES0 5 KILOMETERS

EXPLANATION

STUDY-AREA BOUNDARYBUCK MOUNTAIN STRUCTURE CONTOUR, SMOOTHED— Contour interval, in feet above National Geodetic Vertical Datum of 1929, is variable

500

PENNSYLVANIA

estern Middle Anthracite Coalfield, Schuylkill, Simplified structural contours of the Buck Mountain coalbed used to develop the groundwater-flow model of the W Figure 4.

Columbia, and Northumberland Counties, Pennsylvania.
8 Water budgets and groundwater volumes for abandoned mines in the Western Middle Anthracite Coalfield, Pa

Table 1. Average thicknesses and relative altitudes of economically important coalbeds above the Buck Mountain 

coalbed in the Western Middle Anthracite Coalfield in eastern Pennsylvania.

[n.d., no data. Shaded rows indicate coalbeds that typically were mined, accounting for more than 90 percent of the coal production]

Coalbed 

number1 Coalbed name

Average 

thickness 

of coalbed 

(feet) 2

Relative altitude 

above base of Buck 

Mountain coalbed 

(feet)

Average percentage 

of noncoal waste 

in coalbed3

20 Rabbit Hole 4.6 1,705 n.d.

19 Tunnel 5.5 1,480 n.d.

18 Peach Mountain or Spahn 6.2 1,410 16.1

17 Little Tracy 4.4 1,315 14.3

16 Tracy 3.7 1,250 24.8

15 Little Diamond 4.3 1,150 20.1

14 Diamond 4.6 1,065 23.8

13 Little Orchard 4.8 945 22.9

12 Orchard 5.5 840 26.2

11 Primrose 6.2 705 15.2

10 1/2 Rough 4.0 600 14.0

10 Holmes 5.9 460 12.8

9 1/2 Four Foot 3.7 435 19.0

9 Mammoth Top Split 7.4 315 13.9

8 1/2 Mammoth Middle Split 7.0 285 10.9

8 Mamoth Bottom Split 6.4 270 15.4

7 Skidmore 4.6 190 25.4

6 Seven Foot 4.0 65 25.9

5 Buck Mountain 6.4 0 22.1

4 Coal D (Little Buck Mountain) 2.3 -110 22.8

3 Coal C (Whites) 2.6 -160 8.5

- Coal B 2.0 -260 n.d.

2 1/2 Coal A 3.8 -355 16.6

2 Lykens Valley no. 4 4.4 -485 19.1

1

 Coalbed numbers and names adapted from U.S. Geological Survey coal-investigation maps (Arndt and others, 1963a, 1963b; Danilchik and others, 1955, 1962; Haley and others, 1953, 1954; Kehn and Wagner, 1955; Maxwell and Rothrock, 1955; Rothrock and others, 

1950, 1951a, 1951b, 1953).

2

 Average coalbed thickness and altitudes adapted from Eggleston and others (1999).

3

 Average percentage of noncoal refuse computed from tables in USGS coal-investigation maps.

lose all or most of their flow to underground mines during dry 

periods (Cravotta and Kirby, 2004; Cravotta, 2005). 

In lower reaches of the basin, local streams commonly 

gain groundwater discharged from the flooded mines. This 

groundwater, generally referred to as AMD, is an important 

component of base flow to the local streams (Becher, 1991). 

The AMD emanates from mine openings, fractures in stream 

channels, and other topographically low points overlying the 

mine complexes. Because the AMD is widely contaminated 

with dissolved sulfate, iron, and manganese that originated 

from the weathering of rocks exposed by mining, the water 

quality in streams within and downstream of the mined areas 

is degraded (Cravotta and Kirby, 2004; Cravotta, 2005). 

Despite its degraded quality, the mine-pool water has 

been utilized locally since the early 1980s for thermoelectric 

power generation and associated coal preparation. According 

to Veil and others (2003), the three largest users of mine-pool 

water in the basin are Gilberton Power Company (950 gal/min 

from the Gilberton Mine), Schuylkill Energy Resources 

(1,100 gal/min from the Maple Hill Mine), and Wheelabrator Frackville Energy Co. (600 gal/min from the Morea 

Mine). These users must treat the groundwater to remove 
Streamflow and Groundwater Relations 9

dissolved iron and other contaminants. Although some of the 

water is recycled or recharged back to the mine pool, part 

is evaporated and lost from the basin. Other industries have 

expressed interest in additional consumptive use of the minepool water (Veil and others, 2003; Susquehanna River Basin 

Commission, 2005). 

Streamflow and Groundwater 

Relations

To document streamflow and groundwater relations and 

to update previous water-resources assessments of the study 

area by Ash and others (1949) and Reed and others (1987), the 

most recent available data on streamflow, AMD discharges, 

and mine-pool water levels were compiled and evaluated for 

the current study. The spatial relations among streams, AMD 

discharges, and mine-pool water levels within sub-basins in 

the study area were examined using maps and a geographic 

information system (GIS). 

Streamflow and Mine-Discharge Data

Continuous streamflow was measured by USGS for 

Shamokin Creek near Shamokin during 1953–1982 (Becher, 

1991). This long-term, continuous record immediately downstream from the mined part of the basin is useful to estimate 

groundwater recharge (Risser and others, 2005); however, 

continuous streamflow data were not available elsewhere in 

the study area. Flow rates of AMD sources were measured 

monthly by USGS at selected locations in the study area during 1975–1977 (Growitz and others, 1985; Reed and others, 

1987). However, because rainfall during 1975–1977 was 

nearly 20 percent higher than average for the area (fig. 5), 

many of the reported AMD flow rates during this period were 

a factor of two or more greater than values measured at the 

same sites during 1991 (Wood, 1996) and 1999–2001 (Cravotta and Kirby, 2004; Cravotta, 2005). 

For this study, the synoptic data on streamflow and 

mine-discharge rates that were collected by USGS during 

stable base-flow conditions in 1999–2001 at 49 stream sites 

and 78 AMD sites in the Shamokin and Mahanoy Creek 

Basins (Cravotta and Kirby, 2004; Cravotta, 2005) were used 

to indicate spatial variability within the area. For each stream 

basin, one round of measurements over a 2-day period was 

conducted during low base-flow conditions, and a second 

round was conducted during high base-flow conditions. The 

location of each site was determined by global positioning 

system (GPS), and the surface altitude and surface drainage 

area upstream from each site were determined using USGS 

topographic quadrangle maps or the USGS StreamStats web 

application (U.S. Geological Survey, 2009). The site locations 

are shown in figure 2; site descriptions are given in tables 2 

and 3. (Table 3 at end of report.)

To estimate the long-term average base-flow conditions 

at each site for this study, the average of the low and high 

base-flow measurements in 2000–2001 for the Mahanoy Creek 

Basin was used, and only the high base-flow measurement 

at each site in 2000 for the Shamokin Creek Basin was used. 

The low base-flow measurements for the Shamokin Creek 

Basin were conducted during near-drought conditions in 1999 

(fig. 5). However, streamflow of Shamokin Creek near Shamokin during the high base-flow measurements in 2000 approximated the long-term average (Cravotta and Kirby, 2004). To 

normalize the streamflow values among sub-basins within 

the entire study area, the base-flow yield was computed by 

dividing the estimated streamflow for each site by its upstream 

surface drainage area (table 2). 

The estimated base-flow yields for the sub-basins in the 

study area exhibited a wide range of values (0 to 81 in/yr) 

(table 2) compared to the average base-flow yields reported 

for continuously gaged streams throughout Pennsylvania 

(6 to 27 in/yr) (Risser and others, 2005) and compared to the 

long-term records of annual precipitation for the area (30 to 

74 in/yr) (fig. 5). Locally anomalous base-flow yields (fig. 6) 

result from substantial streamflow losses and gains associated 

with the underground mines that extend beneath local surface 

drainage divides (fig. 7). The sub-basins that exhibited low 

yields (less than or equal to 9 in/yr) were in the headwaters 

areas of Shamokin and Mahanoy Creeks (figs. 5 and 6). With 

the exception of Crab Run (site S21), which was diverted 

for irrigation, the sub-basins with low yields lost streamflow 

by leakage to, or capture by, underground mines. With the 

exception of Rattling Run (site S18), the sub-basins with high 

yields (26 to 81 in/yr) gained base flow from one or more large 

sources of AMD. Downstream from the sub-basin areas underlain by mines, because the losses and gains in the mined area 

cancelled out over the larger basin, the streamflow yields were 

normal compared to other gaged streams in Pennsylvania. 

Despite drier than normal rainfall conditions in 1999–

2001 (fig. 5), the synoptic data of 1999–2001 are considered 

to represent average steady-state base flow for the area. The 

base-flow yields estimated for the lower and middle reaches 

of Shamokin Creek (18.0 to 22.6 in/yr) and the lower reaches 

of Mahanoy Creek (17.0 to 19.7 in/yr) (table 2) compare well 

with the average base-flow yield of 17.6 in/yr (8.1 to 27.8 in/yr 

during 1955–1982) computed by Becher (1991) and averages 

of 18.8 and 21.0 in/yr computed by Risser and others (2005)5

for Shamokin Creek near Shamokin. 

5

Risser and others (2005) used two automated streamflow-hydrograph-analysis methods—PART and RORA (Rutledge, 1998)—to compute groundwater 

recharge from the long-term streamflow record at Shamokin Creek at Shamokin (01554500). The value of 18.8 in/yr was estimated with the computer 

model, PART, whereas the value of 21.0 in/yr was estimated using RORA. 
10 Water budgets and groundwater volumes for abandoned mines in the Western Middle Anthracite Coalfield, Pa

20

30

40

50

60

70

80

Precipitation, in inches

19401950196019701980199020002010

A

B

C

D

EXPLANATION

AVERAGE PRECIPITATION AT TAMAQUA, PA, OVER INVESTIGATION

 PERIOD—Endpoints denotes start and end of investigation period

Mahanoy City

Tamaqua

ANNUAL PRECIPITATION

Ash and others, 1949

Growitz and others, 1985; Reed and others, 1987

Cravotta and Kirby, 2004; Cravotta, 2005

This report

A

B

C

D

Figure 5. Total annual precipitation during 1941 to 2008 for Mahanoy City and Tamaqua, Pennsylvania. Data for 

Mahanoy City during 1972–2008 and Tamaqua are from National Climatic Data Center (2010). Data for Mahanoy City 

during 1941–1952 are from Ash and Link (1953). Horizontal line segments indicate the average annual precipitation at 

Tamaqua for time periods of previous investigations by Ash and others (1949), Growitz and others (1985), Reed and 

others (1987), Cravotta and Kirby (2004), and Cravotta (2005), plus unpublished data collected by the Pennsylvania 

Department of Environmental Protection (this report).
Streamflow and Groundwater Relations 11

Table 2. Site descriptions and estimated streamflow yields for surface drainage sub-basins within Shamokin and Mahanoy Creek 

Basins, Schuylkill, Columbia, and Northumberland Counties, Pennsylvania, 1999–2001

[USGS, U.S. Geological Survey; mi2, square miles; ft3/s, cubic feet per second; in/yr, inches per year]

Local 

identification 

number

Local name

USGS 

station 

number

Latitude Longitude

Drainage 

area 

(mi2)

Streamflow 

(ft3/s)

Yield 

(in/yr)

SC02 Shamokin Creek at Atlas 01554300 40.7914 -76.4408 7.58 0.54 0.97

SC03C N Branch Shamokin Creek at Mount Carmel 01554273 40.8040 -76.4347 4.14 7.40 24.3

SC03D N Branch Shamokin Creek nr Mount Carmel 01554280 40.7988 -76.4366 5.34 14.0 35.6

LC4 Locust Creek at Locust Gap 01554452 40.7808 -76.4480 5.51 1.80 4.44

EX5 Unn Trib to Shamokin Cr at Excelsior 01554456 40.7724 -76.4963 2.30 1.90 11.2

SC06 Shamokin Creek at Ranshaw 01554460 40.7835 -76.5221 24.9 34.0 18.6

QR7 Quaker Run nr Kulpmont 01554462 40.7870 -76.4997 1.52 5.50 49.2

QR8 Quaker Run at Ranshaw 01554465 40.7841 -76.5224 3.68 22.0 81.2

BM9 Big Mtn Mine No. 1 Slope nr Shamokin 01554469 40.7768 -76.5394 1.48 4.10 37.6

SC10 Shamokin Creek at Shamokin 01554471 40.7916 -76.5532 31.7 59.0 25.3

COR11 Coal Run at Shamokin 01554478 40.7916 -76.5532 6.18 1.50 3.30

SC11 Shamokin Creek ab Carbon Run at Shamokin 01554479 40.7893 -76.5629 38.3 3.90 1.38

TR41 Unn Trib to Carbon Run nr Shamokin 01554481 40.7728 -76.6129 1.14 0.92 11.0

CR1 Carbon Run nr Trevorton 01554482 40.7708 -76.6256 0.69 0.24 4.72

CR12 Carbon Rn at Shamokin 01554489 40.7893 -76.5629 8.71 18.0 28.1

FR13 Furnace Run at Shamokin 01554490 40.7893 -76.5629 1.63 0.80 6.67

SC14 Shamokin Creek at Uniontown 01554492 40.8022 -76.5675 49.1 88.0 24.3

SC15 Shamokin Creek nr Shamokin 01554500 40.8104 -76.5841 54.2 90.0 22.6

SC16 Shamokin Creek at Sunbury 01554578 40.8581 -76.7752 136 180 18.0

S01 Mahonoy Creek at Buck Mountain 0155521012 40.8264 -76.0893 0.81 0.00 0.00

S03 Mahanoy Creek nr Mahanoy City 0155521021 40.8158 -76.1232 2.67 0.34 1.70

S04 Mahanoy Creek at Mahanoy City 0155521023 40.8155 -76.1253 2.85 4.45 21.2

S05 Unn Trib to N Mahanoy Creek at Shoemakers 0155521037 40.8324 -76.1262 0.84 0.12 1.94

S06 North Mahanoy Creek at Mahanoy City 0155521049 40.8156 -76.1405 5.95 4.35 9.93

S07 Waste House Run at Yatesville 0155521080 40.8331 -76.1641 0.97 0.72 10.1

S08 Wastehouse Run at St. Nicholas 01555211 40.8048 -76.1769 3.50 0.00 0.00

S09 Mahanoy Creek at Gilberton 0155521140 40.7997 -76.2083 17.9 7.40 5.62

S10 Mahanoy Creek at Girardville 01555212 40.7922 -76.2733 20.8 20.0 13.0

S11 Kehly Run at Shenandoah Heights 0155521206 40.8361 -76.1970 1.00 0.87 11.8

S12 Lost Creek at Lost Creek 0155521332 40.8148 -76.2418 1.06 0.57 7.30

S13 Shenandoah Creek at Lost Creek 0155521334 40.8068 -76.2468 8.90 1.60 2.44

S14 Shenandoah Creek at Girardville 0155521339 40.7959 -76.2757 12.1 8.80 9.88

S15 Centralia Mine Tunnel Trib at Ashland 0155521346 40.7873 -76.3179 37.0 3.15 1.15

S16 Mahanoy Creek at Ashland 0155521356 40.7764 -76.3394 42.8 69.0 21.9

S17 Mahanoy Creek at Gordon 0155521369 40.7568 -76.3403 44.7 79.1 24.0

S18 Rattling Run at Gordon 0155521486 40.7490 -76.3377 2.64 5.80 29.8

S19 Little Mahanoy Creek at Gordon 0155521488 40.7541 -76.3424 11.0 18.4 22.9

S20 Unn Trib to Mahanoy Creek at Lavelle 01555228 40.7536 -76.3726 5.53 3.71 9.10

S21 Crab Run at Taylorville 01555232 40.7462 -76.3915 3.38 1.31 5.24

S22 Mahanoy Creek at Mowry 01555234 40.7525 -76.3972 69.5 103 20.1

S23 Mahanoy Creek nr Gowen City 01555240 40.7404 -76.5486 82.8 152 25.0

S24 Zerbe Run at Trevorton 0155524529 40.7813 -76.6828 3.41 4.31 17.2

S25 Unn Trib to Zerbe Run at Trevorton 0155524558 40.7796 -76.6837 4.61 4.74 14.0

S26 Zerbe Run nr Dornsife 01555246 40.7559 -76.7544 13.1 17.3 17.9

S27 Mahanoy Creek nr Dornsife 0155525004 40.7317 -76.7941 120 174 19.7

S28 Schwaben Creek at Red Cross 0155525061 40.7160 -76.7794 22.6 15.0 9.03

S29 Mouse Creek at Urban 0155525069 40.6894 -76.7714 2.77 2.40 11.8

S30 Mahanoy Creek nr Herndon 01555251 40.7245 -76.8155 155 198 17.4

S31 Mahanoy Creek at Herndon 01555252 40.7262 -76.8375 158 198 17.0
12 Water budgets and groundwater volumes for abandoned mines in the Western Middle Anthracite Coalfield, Pa STUDY AREA

uS qs

eu hanna

i R ev r

uS qs

eu hanna

i R ev r

EXPLANATION

ESTIMATED STREAMFLOW YIELDS PER YEAR, IN INCHES

LESS THAN OR EQUAL TO 99.01–26GREATER THAN 26

LOCAL SUBBASIN IDENTIFIER— Sub-basin description shown in table 2BASIN BOUNDARYSUB-BASIN BOUNDARYSTUDY-AREA BOUNDARYSTREAM

Streams from U.S. Geological Survey National Hydrography Data Set, 2009, 1:100,000Shaded relief prepared from U.S. Geological Survey National Elevation Data Set, 2004

LC4

0 5 MILES0 5 KILOMETERS

PENNSYLVANIA

S31

S30

S27

SC16

S23

S22

S17

S16

SC15

SC14

S15

SC11

SC10 SC6

S28

S10

S09

S26

S14

S19

S13

SC2

CR12

S06

S20

LC4 S25

QR8

S18

EX5

SC3D COR11

S24

S21

SC3C

S04

S29

S03 S08

QR7 FR13

BM9

S12

S07 S11 S05

TR41

S01

CR1

S31

S30

S27

SC16

S23

S22

S17

S16

SC15

SC14

S15

SC11

SC10 SC6

S28

S10

S09

S26

S14

S19

S13

SC2

CR12

S06

S20

LC4 S25

QR8

S18

EX5

SC3D COR11

S24

S21

SC3C

S04

S29

S03 S08

QR7 FR13

BM9

S12

S07 S11 S05

TR41

S01

CR1

76°10' 76°20' 76°30' 76°40' 76°50'

40°50'40°40'

Estimated streamflow yields of surface drainage sub-basins within Shamokin and Mahanoy Creek Basins, Schuylkill, Columbia, and Northumberland Counties, Figure 6.

Pennsylvania, 1999–2001.
Streamflow and Groundwater Relations 13

NORTH FRANKLIN

SCOTT

BEAR VALLEY ROCK SLOPE ENTERPRISE

CAMERON

GLEN BURN

CORBIN

BURNSIDE BIG MOUNTAIN

LOCUST GAP

HICKORY RIDGE

NEILSON

LUKE FIDLER

HENRY CLAY - STIRLING

NATALIE

COLBERT

ROYAL OAK

MAYSVILLE NOS. 1 & 2

EXCELSOR

BUCK RIDGE NO. 2

GREENBACK

NORTH FRANKLIN

SCOTT

BEAR VALLEY ROCK SLOPE ENTERPRISE

CAMERON

GLEN BURN

CORBIN

BURNSIDE BIG MOUNTAIN

LOCUST GAP

HICKORY RIDGE

NEILSON

LUKE FIDLER

HENRY CLAY - STIRLING

NATALIE

COLBERT

ROYAL OAK

MAYSVILLE NOS. 1 & 2

EXCELSOR

BUCK RIDGE NO. 2

GREENBACK

76°30' 76°35' 76°40'

40°48'40°46'40°44'

Streams from U.S. Geological Survey National Hydrography Data Set, 2009, 1:100,000

STUDY AREA

PENNSYLVANIA

Shaded area shown in figure

S t u d y a r e a

0 2 MILES0 2 KILOMETERS

EXPLANATION

BARRIER PILLARSTUDY-AREA BOUNDARYTUNNELSTREAM

estern Middle Anthracite Coalfield, Schuylkill, Columbia, and Northumberland 

B-B’ shown in figure 3.

Approximate locations of principal collieries, barrier pillars, and tunnels within the W Figure 7.

Counties, Pennsylvania. Lines of section indicate approximate locations of cross sections A-A’ and 
14 Water budgets and groundwater volumes for abandoned mines in the Western Middle Anthracite Coalfield, Pa

BAST

POTTS

LOCUST GAP

SAYRE

ALASKA

NATALIE

SCOTT

ENTERPRISE

RICHARDS

RELIANCE

LOGAN

CORBIN

LOCUST RUN

PENNSYLVANIA

HAMMOND

HICKORY RIDGE

TUNNEL

GREENOUGH

GIRARD

COLBERT

RAVEN RUN

MERRIAM

CONTINENTAL

CENTRALIA

SIOUX NO. 1

MAYSVILLE

NOS. 1 & 2

MIDVALLEY

NOS. 1 & 2

PRESTON NO. 3

BIG

MOUNTAIN

PACKER NO. 5

MIDVALLEY NOS. 3 & 4

EXCELSOR

MORRIS RIDGE

BUCK RIDGE

NO. 2

BAST

POTTS

LOCUST GAP

SAYRE

ALASKA

NATALIE

SCOTT

ENTERPRISE

RICHARDS

RELIANCE

LOGAN

CORBIN

LOCUST RUN

PENNSYLVANIA

HAMMOND

HICKORY RIDGE

TUNNEL

GREENOUGH

GIRARD

COLBERT

RAVEN RUN

MERRIAM

CONTINENTAL

CENTRALIA

SIOUX NO. 1

MAYSVILLE

NOS. 1 & 2

MIDVALLEY

NOS. 1 & 2

PRESTON NO. 3

BIG

MOUNTAIN

PACKER NO. 5

MIDVALLEY NOS. 3 & 4

EXCELSOR

MORRIS RIDGE

BUCK RIDGE

NO. 2

BAST

POTTS

LOCUST GAP

SAYRE

ALASKA

NATALIE

SCOTT

ENTERPRISE

RICHARDS

RELIANCE

LOGAN

CORBIN

LOCUST RUN

PENNSYLVANIA

HAMMOND

HICKORY RIDGE

TUNNEL

GREENOUGH

GIRARD

COLBERT

RAVEN RUN

MERRIAM

CONTINENTAL

CENTRALIA

SIOUX NO. 1

MAYSVILLE

NOS. 1 & 2

MIDVALLEY

NOS. 1 & 2

PRESTON NO. 3

BIG

MOUNTAIN

PACKER NO. 5

MIDVALLEY NOS. 3 & 4

EXCELSOR

MORRIS RIDGE

BUCK RIDGE

NO. 2

76°20' 76°25' 76°30'

40°48'40°46'

Streams from U.S. Geological Survey National Hydrography Data Set, 2009, 1:100,000

STUDY AREA

PENNSYLVANIA

Shaded area shown in figure

S t u d y a r e a

0 2 MILES0 2 KILOMETERS

EXPLANATION

BARRIER PILLARSTUDY-AREA BOUNDARYTUNNELSTREAM

estern Middle Anthracite Coalfield, Schuylkill, Columbia, and Northumberland 

B-B’ shown in figure 3.—Continued

Approximate locations of principal collieries, barrier pillars, and tunnels within the W Figure 7.

Counties, Pennsylvania. Lines of section indicate approximate locations of cross sections A-A’ and 
Streamflow and Groundwater Relations 15

B

B'

A

A'

76°5' 76°10' 76°15'

40°50'40°48'40°46'

STUDY AREA

PENNSYLVANIA

Shaded area shown in figure

S t u d y a r e a

Streams from U.S. Geological Survey National Hydrography Data Set, 2009, 1:100,000

0 2 MILES0 2 KILOMETERS

EXPLANATION

BARRIER PILLARSTUDY-AREA BOUNDARYTUNNELSTREAMLINE OF SECTION—Shown in figure 3

A A’

BAST

MOREA

MAPLE HILL

HAMMOND

PRIMROSE

GILBERTON

RAVEN RUN

PARK

NOS. 1 & 2

GIRARD

TUNNEL RIDGE

CONTINENTAL

ST. NICHOLAS

WM. PENN

LAWRENCE

MAHANOY CITY

PACKER

NO. 2

WESTON

PARK NOS. 3 & 4

INDIAN RIDGE

PACKER NO. 5

PRESTON NO. 3

NORTH MAHANOY

VULCAN - BUCK MOUNTAIN

WEST

SHENANDOAH

KNICKERBOCKER

KEHLEY RUN

EAST BEAR RIDGE

PACKER NO. 4

PACKER NO. 3

WEST BEAR

RIDGE

KOHINOOR

BOSTON RUN

BAST

MOREA

MAPLE HILL

HAMMOND

PRIMROSE

GILBERTON

RAVEN RUN

PARK

NOS. 1 & 2

GIRARD

TUNNEL RIDGE

CONTINENTAL

ST. NICHOLAS

WM. PENN

LAWRENCE

MAHANOY CITY

PACKER

NO. 2

WESTON

PARK NOS. 3 & 4

INDIAN RIDGE

PACKER NO. 5

PRESTON NO. 3

NORTH MAHANOY

VULCAN - BUCK MOUNTAIN

WEST

SHENANDOAH

KNICKERBOCKER

KEHLEY RUN

EAST BEAR RIDGE

PACKER NO. 4

PACKER NO. 3

WEST BEAR

RIDGE

KOHINOOR

BOSTON RUN

estern Middle Anthracite Coalfield, Schuylkill, Columbia, and Northumberland 

B-B’ shown in figure 3.—Continued

Approximate locations of principal collieries, barrier pillars, and tunnels within the W Figure 7.

Counties, Pennsylvania. Lines of section indicate approximate locations of cross sections A-A’ and 
16 Water budgets and groundwater volumes for abandoned mines in the Western Middle Anthracite Coalfield, Pa

Mine-Pool Water-Level Data

A total of 69 named underground mines or collieries 

covering an estimated area of more than 85 mi2 were developed within the Western Middle Anthracite Coalfield, with 

individual areas ranging from 0.20 mi2 for the Kohinoor Mine 

to 5.52 mi2 for the Bear Valley Rock Slope (table 4, fig. 7). 

The bottom altitude of the mines, obtained from the lowest 

gangway details shown on mine maps, ranged from -587 ft for 

the Luke Fiddler Mine to 983 ft for the Natalie Mine (table 4). 

The approximate locations of colliery boundaries and associated barrier pillars and tunnels were obtained from unpublished and published maps (Ash and others, 1949, 1953a; 

Gannett Fleming Corddry and Carpenter, Inc., 1972; Sanders 

& Thomas, Inc., 1975; Reed and others, 1987) and used to create GIS files. The GIS and associated digital files on the mine 

locations were only approximate because the source maps 

lacked coordinates and relevant projection information. 

To account for spatial variations in the depth of mined 

coal and the location of coalbeds relative to the water table 

within the mines, the structure contour of the Buck Mountain 

coalbed was digitized from published USGS coal-investigation 

maps (Arndt and others, 1963a, 1963b; Danilchik and others, 

1955, 1962; Haley and others, 1953, 1954; Kehn and Wagner, 

1955; Maxwell and Rothrock, 1955; Rothrock and others, 

1950, 1951a, 1951b, 1953). Because of overturned folds, faulting, and other geologic complexities (fig. 3), the structure-contour base was generalized and simplified (fig. 4). The generalized structure contour of the Buck Mountain coalbed retained 

the regional geometry of the coal basin and was used in this 

study along with values for thickness and relative altitudes of 

other coal beds (table 2) and the maximum depth of mining 

(table 4) in the study area to estimate the approximate volume 

of coal and associated rock that had been mined. 

Unpublished water-level data, measured by PaDEP during 1982–2003 for 46 boreholes in mine pools of the Western 

Middle Anthracite Coalfield (table 5, at end of report; fig. 7), 

were used to indicate the potential for the collieries to be 

flooded and interconnected, the potential directions of groundwater flow, and, ultimately, the volumes of water flowing and 

stored within the mine pools (water budget). Because of the 

extended period and variable seasons of the measurements, 

the average water levels for 1982–2003 are considered to 

represent steady-state groundwater levels. The measurements, 

which were conducted quarterly during 1982–2000 and annually during 2001–03, represent a wide range of rainfall and 

associated hydrologic conditions (fig. 5). Although a few of 

the boreholes exhibited stable water levels, with minimum and 

maximum values about +/- 5 ft of the average, most exhibited 

variations in water levels of +/- 10 to +/- 30 ft of the average (table 5). Flowing boreholes are indicated by a maximum 

groundwater altitude equal to the borehole surface altitude. 

Generally, the most stable water levels were associated with 

flowing boreholes within the valleys, whereas the least stable 

water levels were associated with boreholes in mines along the 

perimeter of the study area. Reed and others (1987) measured 

the water level and water quality in most of these boreholes 

during 1975–77. Despite higher rainfall conditions during 

this earlier study (fig. 5), the range of water levels reported by 

Reed and others (1987) was similar to that recorded for the 

same boreholes in 1982–2003. 

Multicolliery Unit Concept

Because all workings within a mine are connected to 

the mine shaft, directly or by horizontal tunnels, the waterlevel altitudes tend to be uniform within a flooded colliery. 

Where barrier pillars are intact, adjacent collieries can form 

distinctive mine pools with water levels that differ by many 

tens of feet on either side of the barrier. However, if a barrier 

pillar between adjacent collieries was breached, and water 

can flow readily between the collieries, the water levels in 

these adjoining mines tend to be uniform. Where multiple 

collieries are interconnected, discharge is commonly from a 

single AMD source at a topographically low point within this 

“multicolliery” unit (MCU). Generally, the upper limit of the 

water level in a MCU would be controlled by the altitudes of 

breaches in barrier pillars or the approximate surface altitude 

for the primary AMD outlet in the downgradient direction. 

The 69 mapped collieries in the study area were grouped 

as 17 named mine pools or MCUs (table 6, fig. 8) on the 

basis of previously identified mine pools and barrier pillars 

(Ash and others, 1949, 1953a) and on the basis of the uniformity of recently measured groundwater levels and the relative flow rates of primary AMD outlets. Using an approach 

analogous to the computation of the base-flow yield, where 

streamflow was divided by the upstream drainage area, an 

approximate discharge rate for each MCU was computed by 

multiplying the area of the MCU by a specified recharge rate 

of 18.0 in/yr (table 6). Given this recharge over the total area 

of the mines, the corresponding discharge would be 114 ft3/s 

or 51,300 gal/min, with estimated discharge ranging from 

0.92 ft3/s for the Preston MCU to 17.85 ft3/s for the Scott 

MCU. This computation assumes that all the water discharging 

from the mines originates as recharge within the MCU area 

and is proportional to the area; it excludes possible inflows by 

stream leakage to the MCU from outside the area and possible flow to or from adjacent MCUs. The computed discharge 

rate for 14 of the 17 MCUs was within the range of the low 

and high values measured during 1999–2001 for the AMD 

sources within or associated with the MCU area (table 6). This 

general agreement supports the MCU concept. The computed 

discharge for the Girard MCU was smaller than measured, 

possibly because flow to the Girardville Seepage, the primary 

AMD outlet, originates from outside the MCU. In contrast, 

the computed discharges for the Packer MCU and Potts & 

Tunnel Mine MCU were slightly larger than the measured 

values because some of the AMD associated with these units 

was not measured. For example, Cravotta (2005) suggested 

that unsampled discharge from the Tunnel Mine was likely to 

enter the streambed of Mahanoy Creek, thus accounting for 
Streamflow and Groundwater Relations 17

Table 4. Name, year of closure, estimated area, and altitude of deepest mining of collieries in the Western Middle Anthracite Coalfield, 

Schuylkill, Columbia, and Northumberland Counties, Pennsylvania.

[ft, feet above National Geodetic Vertical Datum of 1929; mi2, square miles; n.d., no data]

Colliery name Year 

closed1

Altitude 

of 

deepest 

mining 

(ft)

Area 

(mi2

)

Multicolliery unit 

(MCU) name

Park Nos. 1 & 2 1953 891 1.45 Vulcan

Park Nos. 3 & 4 n.d. 855 1.09 Vulcan

Primrose n.d. 616 1.22 Vulcan

Vulcan-Buck Mountain 1932 349 0.91 Vulcan

North Mahanoy n.d. 833 0.66 Packer

Knickerbocker 1953 534 0.53 Packer

Maple Hill 1954 278 1.65 Packer

Mahanoy City 1953 515 0.68 Packer

Kehley Run n.d. 546 0.36 Packer

Indian Ridge 1932 661 0.85 Packer

Kohinoor 1953 232 0.20 Packer

West Shenandoah n.d. 180 0.71 Packer

Wm. Penn 1946 104 0.67 Packer

Packer No. 4 n.d. 168 0.39 Packer

Packer No. 3 n.d. 335 0.34 Packer

Packer No. 2 n.d. 218 0.53 Packer

Packer No. 5 1959 74 0.83 Packer

Hammond 1954 -78 1.40 Packer

W. Bear Ridge 1938 131 0.37 Girard

Girard n.d. 444 0.59 Girard

Tunnel Ridge 1931 370 1.09 Gilberton

St. Nicholas 1928 128 0.79 Gilberton

Boston Run n.d. 158 0.22 Gilberton

Gilberton 1938 -100 0.90 Gilberton

Lawrence 1938 130 0.53 Gilberton

East Bear Ridge n.d. 674 0.49 Gilberton

Weston 1959 438 0.87 Weston

Continental n.d. 741 0.94 Centralia

Centralia n.d. 701 0.64 Centralia

Logan n.d. 914 0.92 Centralia

Bast 1934 23 2.77 Bast

Preston No. 3 n.d. 265 0.69 Preston

Midvalley Nos. 3 & 4 n.d. 953 0.67 Midvalley

Midvalley Nos. 1 & 2 n.d. 622 2.22 Midvalley

Tunnel 1891 191 0.66 Potts & Tunnel

Colliery name Year 

closed1

Altitude 

of 

deepest 

mining 

(ft)

Area 

(mi2

)

Multicolliery unit 

(MCU) name

Potts 1934 9 2.39 Potts & Tunnel

Morris Ridge n.d. 828 0.35 Scott

Sayre n.d. 574 2.12 Scott

Sioux No. 1 n.d. 419 0.78 Scott

Pennsylvania n.d. 79 1.47 Scott

Richards n.d. 581 1.64 Scott

Natalie 1929 983 2.55 Scott

Greenough 1926 587 1.04 Scott

Scott 1928 -62 1.38 Scott

Germantown (Locust Run) 1960 727 1.34 Locust Gap

Germantown (Merriam) n.d. 574 0.71 Locust Gap

Locust Gap 1955 371 4.87 Locust Gap

Reliance 1953 -93 1.35 Maysville-Corbin

Alaska 1954 474 2.48 Maysville-Corbin

Enterprise 1935 777 2.33 Maysville-Corbin

Excelsor 1935 777 0.27 Maysville-Corbin

Corbin n.d. 324 0.92 Maysville-Corbin

Buck Ridge No. 2 n.d. 258 0.36 Maysville-Corbin

Buck Ridge No. 1 1900 53 0.35 Maysville-Corbin

Maysville Nos. 1 & 2 1966 333 1.23 Maysville-Corbin

Hickory Ridge 1929 132 1.51 Cameron

Luke Fidler 1929 -587 1.05 Cameron

Colbert 1929 203 0.64 Cameron

Neilson 1900 -578 0.76 Cameron

Glen Burn n.d. 139 1.57 Cameron

Cameron 1928 -351 1.73 Cameron

Big Mountain n.d. 305 1.62 Big Mountain

Burnside 1932 184 1.22 Sterling

Bear Valley Rock Slope 1939 394 5.52 Sterling

Henry Clay-Stirling n.d. 19 1.87 Sterling

Royal Oak 1906 616 0.79 Sterling

North Franklin 1929 308 4.68 North Franklin

Morea n.d. n.d. 1.92 Morea

Raven Run n.d. 982 1.04 Raven Run

1

 Year of closure reported by Reed and others (1987). All mines closed by 1966, including those where the year is indicated as “n.d.”
18 Water budgets and groundwater volumes for abandoned mines in the Western Middle Anthracite Coalfield, Pa

Table 6. Names, areas, estimated discharge, and measured discharge from multicolliery hydrologic units in the Western Middle 

Anthracite Coalfield in eastern Pennsylvania.

[MCU, multicolliery unit; AMD, abandoned mine discharge; mi2, square miles; ft3/s, cubic feet per second]

MCU name MCU area 

(mi2)

Estimated 

discharge1

(ft3/s)

Measured discharge2

(ft3/s) AMD site identification number3

Minimum Maximum

Vulcan 4.67 6.19 2.64 14.07 M03+M02

Packer3 11.69 15.49 8.76 15.06 M05+M07+M12+M13+M08+M09

Girard 0.96 1.27 2.73 4.10 M11

Gilberton 4.02 5.33 0 10.83 M04

Centralia 2.49 3.3 2.43 3.86 M19

Bast 2.77 3.67 2.7 6.90 M21+M20+M18

Preston 0.69 0.92 0.67 2.23 M17

Midvalley 2.89 3.83 3.24 7.80 SR05B+SR05A+SR04+SR02

Potts & Tunnel 3.05 4.04 0.77 1.96 M24+M25+M22+M23+M26+M27

Scott 11.35 15.04 9.43 25.66 SR19+SR06+SR31+SR55

Locust Gap 6.91 9.16 8.28 20.72 M29+M31

Maysville-Corbin 9.29 12.3 9.36 20.45 SR12+SR15+SR11+SR21

Cameron 7.26 9.62 5.27 10.02 SR53+SR51A+SR51+SR52+SR36A+SR20

Big Mountain 1.62 2.15 0.51 3.60 SR23

Stirling 9.4 12.45 2.04 15.42 SR49+SR48+SR42+SR22A+SR22B

North Franklin 4.68 6.2 2.56 6.45 M32

Morea 1.92 2.54 1.4 15.00 USGS162

1

 Estimated discharge was computed as the product of MCU area, assumed recharge rate of 18.0 inches per year, and conversion factor of 0.07362.

2

 Measured minimum and maximum discharge was computed as the sum of the minimum or maximum measured discharges, respectively, for sites identified in table 3.

3

 Although initially considered separate MCUs, the Weston Mine and Raven Run Mine were included with the Packer MCU for consistency with Reed and 

others (1987). Some AMD sources associated with these mines could not be measured as reported by Cravotta (2005).
Streamflow and Groundwater Relations 19

NORTH FRANKLIN

SCOTT

STIRLING

CAMERON

MAYSVILLE-CORBIN

BIG MOUNTAIN

LOCUST GAP

NORTH FRANKLIN

SCOTT

STIRLING

CAMERON

MAYSVILLE-CORBIN

BIG MOUNTAIN

LOCUST GAP

55

53

52

50

43

42

40

38

36

35

15

E31

37A

13B

12A

M31

M32

SR21

SR15

SR23

SR53

SR49

SR12

SR19

SR51A

M31

M32

SR21

SR15

SR23

SR53

SR49

SR12

SR19

SR51A

76°30' 76°35' 76°40'

40°48'40°46'40°44'

Streams from U.S. Geological Survey National Hydrography Data Set, 2009, 1:100,000

STUDY AREA

PENNSYLVANIA

EXPLANATION

MONITORING SITES

STUDY-AREA BOUNDARYSTREAM

 Water-level borehole and identifierStreamgageMine discharge and identifier

Shaded area shown in figure

S t u d y a r e a

0 2 MILES0 2 KILOMETERS

M31

36

-level, mine-discharge, and streamflow data used to develop the groundwater- Conceptual multicolliery hydrogeologic units and locations of associated groundwater Figure 8.

flow model of the Western Middle Anthracite Coalfield, Schuylkill, Columbia, and Northumberland Counties, Pennsylvania.
20 Water budgets and groundwater volumes for abandoned mines in the Western Middle Anthracite Coalfield, Pa 55 50 49 48 36 35 33 3231 28 27 25 24 17 16 15 10 E31 47A 37A 30A 26A 13B PENNSYLVANIA SHAFT

SCOTT

BAST

MAYSVILLE-CORBIN

CENTRALIA

LOCUST GAP

CAMERON

MIDVALLEY

PACKER

GIRARD

POTTS & TUNNEL

PRESTON

MIDVALLEY

SCOTT

BAST

MAYSVILLE-CORBIN

CENTRALIA

LOCUST GAP

CAMERON

MIDVALLEY

PACKER

GIRARD

POTTS & TUNNEL

PRESTON

MIDVALLEY

M17

M31

M20

M26

M21

M19 M11

M12

M29

SR21

SR15

SR55

SR12

SR19

SR05B

M13

M17

M31

M20

M26

M21

M19 M11

M12

M29

SR21

SR15

SR55

SR12

SR19

SR05B

M13

76°20' 76°25' 76°30'

40°48'40°46'

BIG

MOUNTAIN

Streams from U.S. Geological Survey National Hydrography Data Set, 2009, 1:100,000

STUDY AREA

PENNSYLVANIA

EXPLANATION

MONITORING SITES

STUDY-AREA BOUNDARYSTREAM

 Water-level borehole and identifierStreamgageMine discharge and identifier

Shaded area shown in figure

S t u d y a r e a

0 2 MILES0 2 KILOMETERS

M31

30A

-level, mine-discharge, and streamflow data used to develop the groundwater- Conceptual multicolliery hydrogeologic units and locations of associated groundwater Figure 8.

flow model of the Western Middle Anthracite Coalfield, Schuylkill, Columbia, and Northumberland Counties, Pennsylvania.—Continued
Streamflow and Groundwater Relations 21

PACKER

VULCAN

BAST GILBERTON

MOREA

GIRARD

CENTRALIA

PRESTON

PACKER

VULCAN

BAST GILBERTON

MOREA

GIRARD

CENTRALIA

PRESTON

8

7

6

5

3

2

9A

4A

1B

57

46

25

24

21

10 58A

47A

18B

11A

M17

M20

M03

M02

M19

M12

M11

M13

M17

M20

M03

M02

M19

M12

M11

M13

76°5' 76°10' 76°15'

40°50'40°48'40°46'

Streams from U.S. Geological Survey National Hydrography Data Set, 2009, 1:100,000

STUDY AREA

PENNSYLVANIA

EXPLANATION

MONITORING SITES

STUDY-AREA BOUNDARYSTREAM

 Water-level borehole and identifierStreamgageMine discharge and identifier

Shaded area shown in figure

S t u d y a r e a

0 2 MILES0 2 KILOMETERS

58A

M13

-level, mine-discharge, and streamflow data used to develop the groundwater- Conceptual multicolliery hydrogeologic units and locations of associated groundwater Figure 8.

flow model of the Western Middle Anthracite Coalfield, Schuylkill, Columbia, and Northumberland Counties, Pennsylvania.—Continued
22 Water budgets and groundwater volumes for abandoned mines in the Western Middle Anthracite Coalfield, Pa

increased metals loads in Mahanoy Creek at Ashland (S16) 

compared to the sum of metals loading from upstream AMD 

sources. Groundwater modeling could indicate potential for 

AMD to discharge within streams or other locations. 

Simulated Water Budgets and Effects 

of Pumping Changes

The focus of this investigation is on the groundwater 

accumulated within high-permeability mine workings, flow 

restrictions through barrier pillars between mines, and the 

localized discharge of AMD from the flooded mines to 

streams, pumping wells, or AMD outflows. Given this focus, 

a groundwater-flow model was developed to simulate groundwater flow through the mines and to compute water budgets in 

the Western Middle Anthracite Coalfield. The numerical model 

was based on a simplified conceptual model of the hydrogeologic system, which can be refined iteratively through evaluation of modeling results and additional data collection. 

Conceptual Model

A simplified conceptual model of steady-state recharge, 

movement, and discharge of groundwater was used to guide 

development of the corresponding numerical groundwaterflow model of the study area. The groundwater system is 

conceptualized as a three-dimensional aquifer recharged by 

uniform infiltration of precipitation and seepage of streamflow 

in losing stream reaches. The complex geologic structure of 

the study area is conceptualized as a layered system with different hydraulic properties for the layers. For purposes of this 

preliminary study, the fractured-rock formations are conceptualized as having a sufficient density of secondary openings 

(interconnected voids) to approximate a porous medium at the 

scale of the investigation. These assumptions ignore many of 

the complexities of the actual groundwater system. Thus, this 

model should not be used for detailed simulation of flow in 

individual mines or estimates of hydraulic properties of individual mine barriers, for example. However, this preliminary 

model tests the conceptual model and illustrates the use of 

such a model to estimate large-scale water budgets and storage 

volumes. The conceptual model includes high-permeability 

flooded mine voids separated by low-permeability barriers, 

with recharge to the mines from vertical infiltration through 

overlying strata.

Three model layers are used to represent the groundwater flow system from the land surface down to the deepest 

mined coal seams. The top model layer 1 represents weathered 

fractured rock and the overlying soil (regolith) and mine spoil. 

Model layer 2 represents potentially less-weathered fractured, 

unmined rock above the mined strata. The properties of these 

two layers are further assumed to be uniform throughout the 

study area, except for a potential difference between properties 

in mined and unmined areas. 

The mined strata are included within layer 3, with uniform hydraulic properties within a mine and abrupt changes in 

hydraulic properties between mined and unmined areas. The 

permeability is assumed to be negligible beneath the deepest 

mined coal seams. 

Many complex features that may exist in the study area 

are not included in this simplified conceptual model. For 

example, transient perched zones have been observed in similar hydrogeologic settings (Callaghan and others, 1998) where 

shallow fracture zones may be temporarily saturated following recharge events. These features may delay and re-direct 

recharge to the deep saturated zone, especially where uncased 

open boreholes exist. For the steady-state model used here, 

recharge is simply conceptualized as a constant vertical flux to 

the saturated zone. 

Mine-pool discharges are conceptualized as conduits that 

originate in the flooded mines (model layer 3) and discharge 

to the streams (layer 1) at the land surface. In cases where 

tunnels or other features route water from the mine location to 

a surface discharge at a distal location, the interaction between 

water in the conduit and in the aquifer is ignored along 

that path.

 Groundwater discharge is simplified by considering 

only discharge to streams, wells, and simulated mine discharges. Although some groundwater discharges as evapotranspiration along the riparian zone of streams, this sink was 

not considered. 

Model Development

A numerical model was used to simulate three-dimensional groundwater flow in the study area. Simulations were 

conducted under steady-state conditions. Steady-state simulations give results that represent the groundwater/surfacewater relations for conditions of average annual groundwater 

recharge and discharge. Transient changes caused by seasonal 

variations in recharge or changes in pumping rates or locations 

were not simulated, although steady-state conditions with 

alternative pumping rates were simulated. 

Computer Code and Grid

The finite-difference computer code MODFLOW-2000 

(Harbaugh and others, 2000) was used with the parameter estimation program (Hill and others, 2000) and the particle-tracking program MODPATH (Pollock, 1994) to simulate threedimensional groundwater flow and display results. A graphical 

user interface linked to Argus Numerical Environments was 

used for pre- and post-processing of data (Winston, 2000). 

The study area was divided into a finite-difference grid 

(figs. 9 and 10) with 3 layers, 70 rows, and 337 columns. 

The horizontal dimensions of the cells were uniformly 656 ft 
Simulated Water Budgets and Effects of Pumping Changes 23

COLUMNS

ROWS

76°10' 76°20' 76°30' 76°40' 76°50'

40°50'40°40'

STUDY AREA

EXPLANATION

0 5 MILES0 5 KILOMETERS

PENNSYLVANIA

D

D'

C'

C

FINITE-DIFFERENCE GRID

Active cells underlain by mined areaActive cells underlain by unmined areaInactive cellsStream cells

STUDY-AREA BOUNDARY

Mine-discharge cellsPumping-well cells

estern Middle Anthracite Coalfield, Finite-difference grid and location of mined area, stream cells, and pumping-well cells for the groundwater-flow model of the W Figure 9.

Schuylkill, Columbia, and Northumberland Counties, Pennsylvania.
24 Water budgets and groundwater volumes for abandoned mines in the Western Middle Anthracite Coalfield, Pa

C C’

EEK CR Y NO A MAH

K CREE SHAMOKIN

LOCUST GA

P

“HELFENSTEIN” TUNNE

L

D D’

SHAMOKIN

RTON GILBE

VERTICAL EXAGGERATION X 10

VERTICAL EXAGGERATION X 10

2,0001,8001,6001,4001,2001,000

800600400200

Altitude, in feet above NGVD 29 Altitude, in feet above NGVD 29 2,000 1,000

0

-1,000-2,000

0 5 MILES0 5 KILOMETERS

0 1 MILE0 1 KILOMETER

estern Middle Anthracite Coalfield, Schuylkill, -flow model of the W column 170 for the groundwater row 36 and (B) Cross sections of finite-difference grid along (A)

races of sections are shown in figure 9.

Figure 10.Columbia, and Northumberland Counties, Pennsylvania. T
Simulated Water Budgets and Effects of Pumping Changes 25

(column width) by 663 ft (row height) in horizontal dimension6

.The model grid was constructed with rows aligned with 

the regional structure of the synclinal geologic units in the 

area (fig. 2). 

The altitude of the top of each model cell in layer 1 was 

set equal to the altitude of land surface on the basis of the 

USGS 30-m digital elevation model (DEM). The thickness 

of all cells in model layer 1 was 16.4 ft. Layer 1 represents 

shallow weathered rock and mine spoil in the study area. 

Model layer 2 is also 16.4 ft thick and represents underlying, unmined bedrock that overlies layer 3. Although data on 

the extent of weathering and fracturing of unmined bedrock 

were not available for this preliminary study, the associated 

hydrological characteristics of the unmined strata are likely to 

be highly variable (for example, Wyrick and Borchers, 1981; 

Callaghan and others, 1998). Preliminary simulations indicated that without water-level measurements in shallow parts 

of the formation, the properties of layers 1 and 2 could not be 

independently identified; therefore, the properties of layer 2 

were assumed for this preliminary model to be the same as 

layer 1. With additional information, this same grid could be 

used with a more-refined conceptual model of the shallow 

strata. Model layer 3 represents the coal-bearing strata, much 

of which has been mined using underground room-and-pillar 

mining techniques. 

The thickness of layer 3, representing coal-bearing strata 

within underground mines, is computed from the depth of 

mining. The top of layer 3 is at the same altitude as the bottom of layer 2. The bottom of layer 3 (fig. 11) was specified 

as either 16.4 ft below the top, or the bottom altitude of the 

deepest mined strata, whichever was lower. The smoothed 

contour map of the structural contours for the Buck Mountain 

coal seam represents the modeled altitude of deepest mining 

in the study area (fig. 4) except where mine map information 

indicates that the deepest mined strata was above the Buck 

Mountain seam.

Boundary Conditions

A no-flow boundary was implicitly specified at the bottom of the model and along the outer boundary of the active 

model cells. The outer boundary of active model cells was 

manually digitized at topographic ridges and stream locations 

outside the Western Middle Anthracite Coalfield. In many 

locations, especially in the western part of the model area, 

the boundary was specified along ridgelines running outside 

valleys adjacent to the coal-area syncline. In the eastern part of 

the model area, the active area was extended to include small 

streams draining away from the mined area. Thus, groundwater flow can discharge beneath the local basin boundary 

to nearby streams, or to local streams within the mined area, 

depending on model hydraulic conductivity and relative 

stream altitudes. However, it is implicitly assumed that no 

groundwater flows across the outside no-flow boundary of 

the model. 

Recharge from Precipitation

Recharge to the saturated zone from local precipitation 

was simulated as a uniform flux across the top of each cell. 

Recharge may actually be greater in mined areas because of 

the focusing effect of surface pits and waste-pile dams, but 

for this preliminary modeling, the recharge value was not 

varied spatially. 

Streams

Streams were simulated by use of the STR package in 

MODFLOW-2000 (Prudic, 1989), which allows streams to 

gain or lose water and accounts for the flow in each stream 

cell (fig. 9) so that losses cannot exceed the simulated streamflow. The stream stage was set equal to the altitude of land 

surface from the USGS 30-m DEM. The top of the streambed 

was assumed to be equal to the stream stage, and the bottom 

of the streambed was 3.28 ft below the stream stage. Stream 

width was simulated as 3.28 ft for all stream cells. These 

stream dimensions are not representative of the real stream 

channels but are used for convenience in these preliminary 

simulations. As assumed in the simplest computational method 

available in the STR package (Prudic, 1989), the stream stage 

does not depend on the simulated streamflow. The hydraulic 

conductivity of the streambed was adjusted (see discussion on 

Model Adjustments).

Coal Mines

Groundwater discharge from the mines was simulated 

with STR cells in model layer 3 (fig. 9). The altitudes of the 

STR heads are set to the altitude for the discharge (table 3). 

These STR cells then route water to the stream network 

in model layer 1 at the location of the discharge. In some 

cases, the location of the STR cell in the model is somewhat 

removed from the surface location of the discharge, especially 

when the discharge is from a tunnel that extends from the mine 

to a stream. The model simulates the flow from the mine into 

the STR boundary, and then that flow is modeled as a tributary 

flow to a surface stream in model layer 1. However, in these 

cases, flow in the tunnel, or in vertical conduits routing water 

to the surface, and interaction with local groundwater outside 

the conduit, is not explicitly simulated. MODFLOW numerical algorithms do not require that STR cells and tributaries 

be in adjacent model cells or layers. This simple approach is 

considered a preliminary approximation of the complex flow 

paths that may occur between the flooded mine and the location of the surface discharge.

Wells

Four pumping wells were simulated to withdraw water 

from the mine pool for industrial use. These wells are simulated as specified fluxes from model cells in layer 3 (fig. 9). 

6

 The model was constructed in length units of meters, which are reported in 

feet for this report, resulting in values that may seem unusual or may convey 

more precision than warranted.
26 Water budgets and groundwater volumes for abandoned mines in the Western Middle Anthracite Coalfield, Pa STUDY AREA 76°10' 76°20' 76°30' 76°40' 76°50' 40°50' 40°40' -500–0 1–500 501–1,000 1,001–1,500 1,501–2,000 2,001–2,030 ALTITUDE OF THE BOTTOM OF MODEL LAYER 3, IN FEET ABOVE NATIONAL GEODETIC VERTICAL DATUM OF 1929

2,000

1,000

0

0

500

-500

0

500

1,000

1,000

500

2,000

2,000

500

0 5 MILES0 5 KILOMETERS

EXPLANATION

STUDY-AREA BOUNDARYBUCK MOUNTAIN STRUCTURE CONTOUR, SMOOTHED—Contour interval, in feet above National Geodetic Vertical Datum of 1929, is variable

500

PENNSYLVANIA

estern Middle Anthracite Coalfield, Schuylkill, Columbia, and Northumberland -flow model of the W Altitude of the bottom of model layer 3 for the groundwater Figure 11.

Counties, Pennsylvania.
Simulated Water Budgets and Effects of Pumping Changes 27

The two pumping wells associated with the Gilberton shaft are 

located within a single model cell and thus are simulated as a 

single pumping well in the model. 

Aquifer Properties

Initial estimates of aquifer properties used in the model 

were based on a preliminary model with homogeneous properties. All parts of the aquifer are assumed to be isotropic in 

the horizontal and vertical. All parameter values were subsequently changed during the model-adjustment procedures 

described in the Model Adjustments section. 

The MCU concept is reflected in the structure of the 

parameters for hydraulic properties of the model. The model 

structure includes a separate zone of hydraulic conductivity for the aquifer formed by flooded coal mines and separate zones for shallow parts of the formation in mined and 

unmined areas. 

Barriers and unmined rock between MCUs may 

have very low permeability. Barriers are modeled using 

the Horizontal-Flow Barrier (HFB) package for MODFLOW-2000 (Hsieh and Freckleton, 1993). Barrier locations 

(fig. 12) were determined from mapped barriers, observed 

water-level differences between MCUs, and preliminary 

model-simulation results. 

Model Adjustments

Model adjustment is a process in which aquifer properties are changed to improve the match between the simulated 

water levels and flows of the model and the measured water 

levels and flows in the physical system. Aquifer properties and 

recharge in the model were adjusted by use of the parameterestimation program that is integrated into MODFLOW-2000 

(Hill and others, 2000) and by manual adjustments. Values 

of recharge, hydraulic conductivity, and streambed hydraulic 

conductivity in the model were adjusted by trying to match 

measurements of (1) average water levels in 42 observation 

wells monitored by PaDEP (table 5) and (2) streamflow measured by USGS (Cravotta and Kirby, 2004; Cravotta, 2005) 

at 33 locations (table 2). Additional historical data from other 

sources and from new field studies could be incorporated to 

refine values of aquifer properties, as well as refine barrier 

locations, discharge locations and altitudes, and other aspects 

of the model.

Weighting of Measurements

In the parameter-estimation program, residuals (computed as the difference between observed and simulated 

values) in streamflow were multiplied by a weighting factor, 

primarily to convert discharge rates to the same units as waterlevel measurements. The value of the weighting factor was 

chosen so that the sum of weighted residuals for the streamflow measurements would be about the same magnitude as for 

the sum of weighted residuals for water-level data from wells. 

Streamflow residuals, in cubic meters per day, were each multiplied by 0.001, yielding about half of total model error due to 

flow errors.

For preliminary model simulations, none of the waterlevel measurements were weighted (weighting factor =1). This 

is a limitation of the preliminary work that could affect estimates of hydraulic parameters and limits the usefulness of the 

uncertainty estimates from the model-calibration procedures. 

Adjusted Model Parameters

Eight parameters were used to represent hydrologic properties in the model (table 7). Five parameters were used to estimate the aquifer hydraulic conductivity, and two parameters 

were used for streambed vertical hydraulic conductivity. The 

uniform recharge rate was defined by parameter RECH. Each 

parameter was either assigned a value or it was optimized 

by the parameter-estimation process in MODFLOW-2000. 

Model adjustments focused on parameters that, when changed, 

caused the greatest proportional change in simulated water 

levels and flow, which are indicated by their composite scaled 

sensitivities (fig. 13). The composite scaled sensitivity is the 

rate of change in the parameter-estimation optimization objective function for incremental changes in the parameter value, 

normalized by the optimum parameter value. Thus, the overall 

model error changes the most for (proportional) changes in 

parameters with the highest composite scaled sensitivities 

(Hill and others, 2000). Changes to the values of parameters 

that have low composite scaled sensitivity will cause small 

changes in the model error. Values for KM, STR, and RECH 

were optimized by MODFLOW-2000, and the others were 

assigned values on the basis of the initial automatic parameter-estimation trials. These manually adjusted values were 

specified for parameters for which the automatic procedure 

yielded unrealistically low or high values and for insensitive parameters that did not substantially affect model error. 

Parameter K1 had a relatively high composite scaled sensitivity, but it was also correlated with RECH, KM, and STR, and 

for this reason its value was manually assigned after several 

initial optimizations. 

The adjusted values of hydraulic conductivity used in 

the model are shown in table 7. Parameters K1 and K3 were 

manually limited to reasonable values. Model error was 

relatively insensitive to K3, probably because all groundwaterlevel measurements were in mined areas and this parameter is 

applicable in deep unmined areas. Although the sensitivity to 

K1, the hydraulic conductivity of shallow parts of the aquifer 

above the mine layer, is relatively large, automatic calibration 

yielded an unrealistically low value of the hydraulic conductivity of shallow aquifers, resulting in groundwater levels 

well above land surface. Use of measurements of shallow 

aquifer groundwater levels would likely yield a much better 

estimate of this parameter. Model error was minimized with 

low values of these parameters, but K1 was set high enough 

to prevent excessively high water-levels in unmined areas. If 
28 Water budgets and groundwater volumes for abandoned mines in the Western Middle Anthracite Coalfield, Pa STUDY AREA EXPLANATION

0 5 MILES0 5 KILOMETERS

PENNSYLVANIA

COLUMNS

ROWS

76°10' 76°20' 76°30' 76°40' 76°50'

40°50'40°40'

FINITE-DIFFERENCE GRID

Active cells underlain by mined areaActive cells underlain by unmined areaInactive cells

HORIZONTAL FLOW BARRIERS

Low permeabilityHigh permeabilitySTUDY-AREA BOUNDARY

estern Middle Anthracite Coalfield, Schuylkill, Columbia, Locations of high- and low-permeability barriers between mines for the groundwater-flow model of the W Figure 12.

and Northumberland Counties, Pennsylvania.
Simulated Water Budgets and Effects of Pumping Changes 29

Table 7. Parameters used in the groundwater-flow model of Western Middle Anthracite Coalfield, Schuylkill, Columbia, and 

Northumberland Counties, Pennsylvania.

[ft/d, feet per day; in/yr, inches per year; AUTO, automatic calibration; MAN, manual limit based on preliminary automatic calibration]

Parameter 

name Description Model layer Adjusted value (ft/d, except as indicated)

Estimation 

method

K1 Hydraulic conductivity of overburden and shallow weathered 

rocks 1 and 2 3.28 MAN

K3 Hydraulic conductivity of deep unweathered, unmined rocks Unmined parts of 3 0.0033 MAN

KM Hydraulic conductivity of deep unweathered, mined coal 

strata Mined parts of 3 77.9 AUTO

STR Streambed hydraulic conductivity of natural streams 1 1.95 AUTO

STRC Streambed hydraulic conductivity of coal-mine discharges 3 656 MAN

KB_LOW Hydraulic conductivity of low-permeability barriers that 

restrict flow between MCUs 3 3.28 x 10-4 MAN

KB_HIGH Hydraulic conductivity of high-permeability barriers that do 

not restrict flow between MCUs 3 3.28 MAN

RECH Uniform recharge to groundwater 1 19.1 in/yr AUTO

8.09

0.051

8.56

1.95

0.99

2.28

0.068

22.8

Composite scaled sensitivity 100.00

10.00

1.00

0.10

0.01 K1 K3 KM STR STRC KB(LOW) KB(HIGH) RECH

Hydraulic parameter

Figure 13. Composite scaled sensitivity of hydraulic parameters 

used in the groundwater-flow model of the Western Middle 

Anthracite Coalfield, Schuylkill, Columbia, and Northumberland 

Counties, Pennsylvania. (See table 2 for definition of parameters.) 

K1 is reduced much further, simulated water levels outside the 

model area would be well above land surface in many areas. 

Automatic calibration procedures were used to identify 

the optimum value of parameter KM, the hydraulic conductivity of the flooded coal mines, KM = 77.9 ft/d. This high 

value supports the conceptual model of high permeability, or 

little resistance to flow, and hence little water-level variability, within flooded mines. For comparison, Saad and Cravotta 

(1991) estimated the hydraulic conductivity of coal-mine spoil 

as 10 to 100 ft/d using a cross-sectional flow model. In contrast, Harlow and LeCain (1993) reported a median transmissivity value of about 0.1 ft2

/d for unmined coal seams, which 

would correspond, for a 3-ft seam, to a hydraulic conductivity value of about 0.03 ft/d. Thus, the hydraulic conductivity 

estimated in the present study for the flooded coal-mine layer 

in the model is orders of magnitude larger than the hydraulic 

conductivity of unmined coal. 

Model results indicate that some barriers are restrictive 

for flow between MCUs, while other mapped barriers do not 

substantially restrict flow. Model error is lowest for a very low 

value of KB_LOW of 3.28 x 10-4 ft/d and a very high value of 

KB_HIGH of 3.28 ft/d. The value used here for intact barriers 

is much lower than estimates by McCoy and others (2006) of 

0.12 to 0.59 ft/d for intact bituminous coal barriers. Harlow 

and LeCain (1993) report unmined coal seam hydraulic conductivities of as low as 10-4 ft/d, as tabulated by McCoy and 
30 Water budgets and groundwater volumes for abandoned mines in the Western Middle Anthracite Coalfield, Pa

others (2006, p. 280). An example of the effect of changing 

barrier hydraulic conductivity is discussed below. A systematic 

test was not done to see how results would change for different designations, or model structures, of which barriers are 

intact and which are not. 

The streambed vertical hydraulic conductivity for the 

natural streams in model layer 1, STR, is estimated to be 

1.95 ft/d. This value is large enough that the differences 

between the aquifer water levels in the stream cells and the 

stream altitudes are less than 5 ft. Most available information 

about this parameter is from other regional model studies. Lewis-Brown and others (2005) noted that “the vertical 

hydraulic conductivity of a streambed is difficult to measure in 

the field” and estimated a parameter value of 1 ft/d for a model 

of flow in a fractured-rock aquifer in the Passaic Formation of the Newark Basin. Carleton and Gordon (2007) used 

streambed vertical hydraulic conductivities of 0.13 to 26 ft/d 

for a model of flow in a carbonate valley. Risser (2006) used 

streambed vertical hydraulic conductivities of up to 500 ft/d 

for streams in an area with carbonate rocks known to exhibit 

karstic features. 

STRC, the streambed vertical hydraulic conductivity for 

mine discharges in model layer 3, was set at a limiting value, 

656 ft/d. Model error was minimized with higher values but 

was only slightly smaller because model error is insensitive 

to this parameter. However, calibration does indicate that 

this value should be large. This value is similar to the highest 

value, 500 ft/d, used by Risser (2006) for surface streams in a 

carbonate valley underlain by karst. 

Automatic calibration procedures were also used to 

estimate the recharge rate (RECH) of 19.1 in/yr. This estimate 

compares well with the long-term estimates of recharge of 

18.8 to 21.0 in/yr computed by Risser and others (2005) and 

17.6 in/yr computed by Becher (1991) on the basis of streamflow hydrograph analysis for Shamokin Creek near Shamokin. 

These recharge estimates also compare well with the baseflow yields estimated for the middle and lower reaches of 

Shamokin Creek (18.0 to 22.6 in/yr) and the lower reaches of 

Mahanoy Creek (17.0 to 19.7 in/yr) (table 2). 

Simulated and observed water levels are compared in 

figure 14. Steady-state groundwater levels simulated by the 

model are compared to the average of the mine-pool waterlevel data (table 5). The model simulates the regional differences in groundwater altitude reasonably well with a rootmean-square error of 11.2 ft; however, the differences between 

simulated and observed water levels are as large at 100 ft 

(fig. 14), probably because of local heterogeneity of the formations and mines. Note that most boreholes exhibited temporal 

variations in water level of 20 to 60 ft (table 4). This suggests 

that the preliminary model should be used with caution for 

making predictions at the local scale.

Streamflow simulated by the model was compared to 

measured flow from the synoptic surveys of 1999–2001 

(fig. 15). The simulated rate that water is gained or lost in 

streams is sensitive, in part, to the hydraulic conductivity of 

the streambed. A single value of streambed hydraulic conductivity was used for the entire model area for streams in model 

layer 1. Streams in model layer 3 represent mine discharges 

Simulated

water level, in feet

Observed water level, in feet

600 700 800 900 1,000 1,100 1,200 1,300 1,400

1,400

1,300

1,200

1,100

1,000

900

800

700

600

L I N E O F E Q U A L I T Y

Figure 14. Relation between observed and simulated 

groundwater levels simulated by use of the groundwater-flow 

model of the Western Middle Anthracite Coalfield, Schuylkill, 

Columbia, and Northumberland Counties, Pennsylvania. 

Simulated stream gain, in cubic feet per second

Observed stream gain, in cubic feet per second

-10 0 10 20 30 40 50 60

60

50

40

30

20

10

0

-10

L I N E O F E Q U A L I T Y

Figure 15. Relation between observed and simulated base-flow 

gain (>0) or loss (<0) simulated by use of the groundwater-flow 

model of the Western Middle Anthracite Coalfield, Schuylkill, 

Columbia, and Northumberland Counties, Pennsylvania. 
Simulated Water Budgets and Effects of Pumping Changes 31

and are modeled with a separate value of streambed hydraulic 

conductivity, which is also uniform for the entire model area. 

The simulated stream base-flow gains do not match the 

observed values as well as the groundwater levels. The two 

large observations are reproduced fairly well, indicating that 

the model reasonably matches the overall recharge and base 

flow for the model area. However, local gains and losses 

on smaller streams are not well matched, probably because 

of local heterogeneity that is not well characterized in the 

preliminary model. 

Preliminary Results of Model Simulations

Preliminary results from modeling simulations are 

described in this section. Simulations were conducted for 

three cases: (1) current conditions, (2) increased pumping in 

the Gilberton area, and (3) an example of additional model 

adjustments to simulate a specific mine-discharge rate that 

was not reproduced by the calibrated model. 

Current Conditions

Groundwater flow in the study area was simulated under 

steady-state conditions corresponding to average recharge 

and pumping, and conditions reflected by the streamflow and 

water-level measurements used for model calibration. The 

simulated water-table surface is shown in figure 16. Water 

levels are relatively flat within simulated MCUs and relatively steep outside the mined area. Large hydraulic gradients 

also occur across many simulated barriers between MCUs. 

These results are generally consistent with observed waterlevel data where more than one well is available within a 

single MCU. However, no water-level information outside 

the mined area, or in shallow parts of the aquifer, was used 

for this preliminary study. 

The results of the groundwater-flow model include 

contribution areas for discharges. The source of water for the 

system is recharge from the water table and streamflow loss, 

and different areas contribute recharge to different discharges. 

Forward particle tracking using MODPATH (Pollock, 1994) 

determined the ultimate discharge locations of parcels of water 

originating at the top of each cell in the top layer of the model. 

In general, areas near streams contribute recharge to streams, 

and areas upgradient from pumping wells contribute water to 

the wells. Mine discharges capture substantial amounts of the 

groundwater in the mined areas (fig. 17). 

A water budget for the aquifer system was computed 

from the model results (table 8). On average, most recharge in 

the study area discharges as base flow to streams, but 41.1 percent discharges from mine outflows, and about 1.5 percent 

discharges from pumping wells. Model limitations, including few hydraulic parameters, result in simulated discharges 

that do not match measured discharges at many locations. 

For example, the largest measured discharge in the Shamokin 

Creek Basin, at the Scott Ridge Mine Tunnel (table 3, SR19, 

9.4 to 19 ft3/s), is simulated as zero discharge in the calibrated 

model. The next section presents an example of modifying 

model parameters to provide better resolution of particular 

model results. 

The stream reaches that were simulated as providing 

recharge to the aquifer (base-flow loss) and receiving discharge from the aquifer (base-flow gain) for current conditions 

are shown in figure 18. The data are shown as shading of finite 

difference cells according to the rate of volumetric recharge 

to the groundwater system from the stream; base-flow gain 

is shown as negative recharge and base-flow loss is shown as 

positive recharge. Reaches that were neither gaining nor losing 

reaches are dry; these are indicated by no shading of the finite 

difference cell where the stream is located. 

Outside the mined area, nearly all streams are gaining 

in the steady-state model. Minor areas of simulated loss may 

Table 8. Water budget for current conditions simulated by use of the groundwater-flow model of the Western 

Middle Anthracite Coalfield, Schuylkill, Columbia, and Northumberland Counties, Pennsylvania.

Source of inflow Rate 

(cubic feet per second)

Recharge 350.3

Source of outflow Rate 

(cubic feet per second) Percent of total outflow

Net discharge to streams, excluding mine discharges 197.5 56.4

Stream gains 205.1

Stream losses 7.5

Mine discharge 147.3 42.1

Pumping wells 5.4 1.5
32 Water budgets and groundwater volumes for abandoned mines in the Western Middle Anthracite Coalfield, Pa STUDY AREA 76°10' 76°20' 76°30' 76°40' 76°50' 40°50' 40°40' 1,201–1,300 1,301–1,400 1,401–1,500 1,501–1,600 1,601–1,700 1,701–1,800 1,801–2,120 SIMULATED WATER LEVELS IN THE COAL-MINE LAYER, IN FEET ABOVE NATIONAL GEODETIC VERTICAL DATUM OF 1929 498–600 601–700 701–800 801–900 901–1,000 1,001–1,100 1,101–1,200 EXPLANATION STUDY-AREA BOUNDARY

0 5 MILES0 5 KILOMETERS

PENNSYLVANIA

estern Middle Anthracite Coalfield, Schuylkill, Columbia, and -flow model of the W ater-table altitude for current conditions simulated by use of the groundwater W Figure 16.

Northumberland Counties, Pennsylvania.
Simulated Water Budgets and Effects of Pumping Changes 33 STUDY AREA

76°10' 76°20' 76°30' 76°40' 76°50'

40°50'40°40'

SIMULATED AREA CONTRIBUTINGGROUNDWATER RECHARGE TO:

Mahanoy basin streamsShamokin basin streamsRoaring and Catiwissa basin streamsSchuylkill basin streamsPumping wellsMine discharges

EXPLANATION

0 5 MILES0 5 KILOMETERS

PENNSYLVANIA

STUDY-AREA BOUNDARY

-flow model of Areas contributing precipitation recharge to mine discharges, pumping wells, and streams for current conditions simulated by use of the groundwater Figure 17.

the Western Middle Anthracite Coalfield, Schuylkill, Columbia, and Northumberland Counties, Pennsylvania.
34 Water budgets and groundwater volumes for abandoned mines in the Western Middle Anthracite Coalfield, Pa STUDY AREA 76°10' 76°20' 76°30' 76°40' 76°50' 40°50' 40°40' -1.2669 – -0.4000 -0.3999 – -0.1250 -0.1249 – -0.0400 -0.0399 – 0.0000 0.0001 – 0.0400 0.0401 – 0.0854 STREAM LOCATION OF MINE DISCHARGE RECHARGE TO GROUNDWATER FROM STREAMFLOW IN CUBIC FEET PER SECOND STUDY-AREA BOUNDARY EXPLANATION

0 5 MILES0 5 KILOMETERS

PENNSYLVANIA

estern Middle Anthracite Rate of volumetric recharge from streams (base-flow loss) for current conditions simulated by use of the groundwater-flow model of the W Figure 18.

Coalfield, Schuylkill, Columbia, and Northumberland Counties, Pennsylvania. Discharge to streams (base-flow gain) is shown as negative volumetric recharge.
Simulated Water Budgets and Effects of Pumping Changes 35

be related to inaccurate stream altitudes in the model, which 

were estimated from the 30-m DEM. In contrast, many areas 

of stream loss are simulated within the mined area. Streamflow in headwater streams originating outside the mined area 

is lost to the aquifer above the mines as the stream flows 

into the mined area. This captured streamflow mostly flows 

to mine discharges, which flow back into streams, and some 

flows to pumping wells. However, the streamflow loss may 

not necessarily return to the same stream network when it 

eventually discharges. 

Increased Pumping in Gilberton Area 

The groundwater-flow model can be used to simulate the 

impact of changes in hydrologic conditions, such as changes 

in pumping from wells. Increased pumping will lower water 

levels in the vicinity of the pumping well. The magnitude and 

spatial extent of water-level decrease, or “drawdown,” in the 

aquifer is controlled by the aquifer properties and groundwater 

boundary conditions. The increased groundwater discharge to 

the well will be balanced by reductions in other discharges or 

increases in recharge. In this study, recharge from precipitation 

is assumed to be unaffected by pumping, but stream baseflow loss (recharge from streams) can increase with increased 

pumping. Thus, increased pumping will be balanced by 

decreases in mine discharges and net discharge to streams. 

The groundwater flow in the basin was simulated under 

steady-state conditions with an increase of pumping withdrawals in the Gilberton area of 7 Mgal/d, which has been approved 

by the Susquehanna River Basin Commission (2005) for a 

proposed coal gasification and liquefaction facility. All other 

model parameters and input were the same as the currentconditions case. The simulations indicate that, when compared 

to current conditions, increased pumping in the Gilberton area 

has an effect on regional groundwater levels and on locations 

of source zones for mine discharges and, to a lesser extent, 

streamflow. The rates of discharge to AMD and net discharge 

to streams are also reduced. 

The simulated drawdown in regional groundwater levels 

from current conditions caused by the increased pumping 

of 7 Mgal/d in the Gilberton area is shown in figure 19. The 

largest decline is centered near the Gilberton shaft, where the 

pumping takes place. The shape and extent of the area of influence reflects the high hydraulic conductivity of the MCUs and 

the restriction to flow across mine barriers. Drawdown gradients are steepest at mine-barrier locations. Although figure 

19 shows only the area with a simulated drawdown of 1 ft or 

more, the influence of the groundwater withdrawal extends to 

the boundaries of the model area at steady state. 

The areas contributing recharge from precipitation to 

gaining streams, mine discharges, and pumping wells are also 

shown in figure 19. The total area of recharge from precipitation flowing to the pumping wells is increased. Some of 

the water that would have discharged as mine outflows or as 

streamflow is now flowing to the pumping well. Changes in 

the source areas extend beyond the pumped MCUs. These 

changes in source and discharge relations reflect the complex 

three-dimensional patterns of groundwater flow in the highly 

heterogeneous mine and barrier aquifer system. 

The simulated water budget with increased pumping in 

the Gilberton area is shown in table 9. Compared to the budget 

for current conditions (table 8), the differences are increased 

discharge to pumping wells, reductions in discharges to mine 

discharges and streams, and a small increase in streamflow loss. 

Most of the increased flow to the pumping well is balanced by a 

reduction in discharge from mine outflows. 

Example of Additional Model Adjustments

Although the preliminary groundwater-flow model qualitatively reproduces many features of the actual flow system, such 

as mine outflows and dry, losing, and gaining stream segments, 

some of the observed hydrological features are not well-reproduced. For example, the model simulated no discharge at the 

Scott Ridge Mine Tunnel; however, this is the largest observed 

discharge in the Shamokin Creek Basin. This section presents 

an example of how model parameters and structure could be 

further adjusted to better match specific observed features. By 

changing the model structure and adding new parameters, it is 

likely that the overall model error could also be further reduced. 

However, additional adjustments, other than that illustrated 

here as an example, were beyond the scope of this study.

To better match the observed flow at the Scott Ridge Mine 

Tunnel, an alternative model with modified mine barriers and 

mine hydraulic conductivity was constructed. Changes to the 

model were (1) barrier hydraulic conductivity reduced from 

KB_HIGH to KB_LOW for barriers between the Natalie and 

Hickory Ridge collieries; (2) barrier hydraulic conductivity 

increased from KB_LOW to KB_HIGH for the Scott, Pennsylvania, and Sioux No. 1 collieries; and (3) hydraulic conductivity of model layer 3, representing mined strata, increased to 

3,280 ft/d. The locations of these changes are shown on figure 

20. The preprocessor provided full control of the model parameters and structure and included a graphical user interface for 

changing other model features, such as pumping rates at wells, 

and well locations. 

This example shows that the model parameters can be 

further refined to better match specific observed features. After 

refinement, the simulated discharge at the Scott Ridge Mine 

Tunnel was 17.6 ft3/s, compared to the observed discharge 

rate of 17.5 ft3/s. The preliminary model for current conditions 

described above did not simulate any mine discharge at this 

model location. 

It should be noted, that overall, the model error was 

increased by the changes for this example to match the discharge from the Scott Ridge Mine Tunnel because water 

levels and discharges also changed at other model locations. 

Future refinement of the model could focus on modification 

of model parameters and structure that improved the match 

to specific model features while also reducing overall model 

error. However, these refinements were not pursued for this 

preliminary model. 
36 Water budgets and groundwater volumes for abandoned mines in the Western Middle Anthracite Coalfield, Pa

1

2

2

2

3

3

3

4 4

6 7

7

8

10

9

5

5

1

1

76°8' 76°10' 76°12' 76°14' 76°16'

40°50'40°48'40°46'

EXPLANATION

SIMULATED AREA CONTRIBUTING GROUNDWATER RECHARGE TO:

Mahanoy basin streamsRoaring and Catiwissa basin streamsSchuylkill basin streams

Pumping wellsMine discharges

STUDY-AREA BOUNDARYLINE OF EQUAL DRAWDOWN, IN FEETLOCATION OF PUMPING WELL

5

76°8' 76°10' 76°12' 76°14' 76°16'

40°50'40°48'40°46'

BASE ENDING ZONES ENDING ZONES WITH INCREASED PUMPING BY GILBERTON

0 2 MILES0 2 KILOMETERS

0 2 MILES0 2 KILOMETERS

Regional steady-state drawdown in layer 3 with increased pumping of mine-pool water in the Gilberton area and areas contributing recharge from precipitation 

-flow model of the Western Middle Anthracite Coalfield, Schuylkill, Columbia, and Northumberland Counties, 

Figure 19.to different discharges simulated by use of the groundwaterPennsylvania. 
Simulated Water Budgets and Effects of Pumping Changes 37

Table 9. Water budget for increased pumping from mine pool in Gilberton area simulated by use of the groundwater-flow model of 

the Western Middle Anthracite Coalfield, Schuylkill, Columbia, and Northumberland Counties, Pennsylvania.

Source of inflow Rate

(cubic feet per second)

Recharge 350.3

Source of outflow Rate

(cubic feet per second)

Percent of 

total outflow

Change in percent of 

total outflow1

Net discharge to streams, excluding mine discharges 196.2 56 -0.4

Stream gains 203.9

Stream losses 7.7

Mine discharge 137.9 39.4 -2.7

Pumping wells 16.2 4.6 3.1

1

 Change in percent of total outflow from current-conditions scenario (table 8).

Barrier hydraulic conductivity 

increased from KB_LOW to KB_HIGH

Aquifer hydraulic conductivity 

increased to 3,280 feet per day

Scott Ridge Mine 

Tunnel discharge

AMD discharges

Barrier hydraulic conductivity 

reduced from KB_HIGH to KB_LOW

Streams

Figure 20. Modifications to mine-barrier hydraulic conductivity for alternative groundwater-flow model for the Western Middle 

Anthracite Coalfield, Schuylkill, Columbia, and Northumberland Counties, Pennsylvania. This annotated screenshot of the model 

preprocessor shows mine barriers with low (blue and light blue lines) and high (red and orange lines) hydraulic conductivity, mine-pool 

discharge locations, streams, and a color map of model layer 3, the mine layer, showing unmined areas (blue shading), mined areas 

(green shading), and mined areas with aquifer hydraulic conductivity increased to 3,280 feet per day (red shading). Use of tradenames 

for identification only. 
38 Water budgets and groundwater volumes for abandoned mines in the Western Middle Anthracite Coalfield, Pa

Limitations of the Preliminary Model Results

Because the purpose of this report was to develop a 

preliminary model of groundwater flow, the limitations of the 

results presented are substantial and need to be recognized. 

Portions of this section are drawn directly from the report by 

Risser (2006), which describes a similar preliminary model 

study. Fundamentally, the study was conducted with readily available data sets and was designed to be a “first cut” 

for demonstrating the usefulness of groundwater modeling 

for simulating current conditions and the potential effects of 

increased pumping from the mine pool. A thorough evaluation 

of the conceptual model, analysis of model sensitivity, and 

determination of the effects of boundary conditions has not 

been conducted.

The groundwater-flow model is based on a simplified 

conceptualization of steady-state groundwater flow in aquifers characterized by mining voids and fractured bedrock. 

Although there was reasonably good agreement between measured and simulated water levels and groundwater discharge 

as viewed on a regional perspective, the poor agreement of 

measured water levels when viewed at the local scale may be 

an indication that the extreme heterogeneity of the flooded 

mines, barriers, and overlying fractured rock is not being well 

represented by the model at the local scale.

Several important assumptions were made about groundwater recharge in the preliminary modeling that directly affect 

the water budgets and size of the simulated areas contributing 

groundwater recharge to the pumping wells. Recharge to the 

groundwater system was assumed to be spatially and temporally uniform. Groundwater recharge rates probably vary in 

the study area, especially between mined areas, surface mine 

pits and spoil piles, and undisturbed areas. In addition, the 

magnitude of groundwater recharge to the fractured rocks and 

mine pools from infiltration of streamflow is not well known, 

but the streamflow data suggest that locally, streamflow leakage is a major source of recharge in some areas. 

Results of model simulations were shown to be most 

sensitive to recharge, hydraulic conductivity of the shallow 

parts of the aquifer, and effective hydraulic conductivity of the 

flooded mines and barriers. The effect of changing values for 

these hydrologic properties was not thoroughly tested in this 

preliminary study. Use of water levels from wells outside the 

mined area, and from shallow parts of the aquifer, are suggested to improve the model accuracy in these areas. 

Because the model is steady-state, no information is 

available from the simulations about the storage capacity of 

the mine pools. The storage coefficient represents the change 

in water volume stored in the aquifer due to a change in the 

hydraulic head. Transient (non-steady-state) simulation of 

the effects of seasonal changes in recharge or changes in 

pumping rates, along with measurements of contemporaneous changes in water levels and streamflow, could be used to 

estimate the effective storage coefficient for the mine pool and 

fractured-rock aquifer. Analysis of precipitation, continuous 

water levels, and continuous discharge rates can also be used, 

at least qualitatively, to characterize mine-pool storage (for 

example, Hawkins and Dunn, 2007; Sahu and others, 2009). 

Calibration of this groundwater-flow model using similar transient data could provide a quantitative estimate of the storage 

capacity of the mine pool, independent of estimates of porosity 

or thickness of mine openings after subsidence. 

The data used for adjustment of the model were of variable quality, but for preliminary simulations, the strategy was 

to use available data on mine-pool water levels and representative streamflow measurements. Mine-discharge flow rates 

were not used for model calibration. The only weighting of 

measurements was that to account for different units of measurement between water levels and flows, and this was done 

so that the total model error was approximately half due to 

water-level errors and half due to flow errors. A more rigorous 

weighting of the observed data may help provide better results 

for aquifer parameters. Measurements at additional locations 

could allow for additional detail in the model parameters, such 

as having multiple zones of hydraulic conductivity. Model 

calibration indicated that the spatial variability in aquifer 

parameters is not well defined. 

An inherent limitation of the model is in the assumption 

that the hydraulic properties of fractures and flooded mines are 

represented by an equivalent set of hydraulic properties for a 

porous medium. The continuum approach is usually adequate 

for simulating steady-state groundwater flux at large scales 

incorporating numerous fractures but may be invalid at the 

local scale if only a few discrete fractures or conduits control groundwater flow paths. In the groundwater-flow model, 

mine pools having high transmissivity has been theorized and 

were simulated explicitly in the model; however, many other 

zones of preferential flow may exist that were not explicitly 

included. In particular, discrete flow paths from underground 

mines to surface discharges are approximated as stream 

boundary conditions within the mines, and without explicit 

simulation of flow to surface discharges, which may occur 

through small high-permeability features. 

Estimated Groundwater Volume and 

Distribution

For the current study, the total volume of water in the 

mine pools of the Western Middle Anthracite Coalfield was 

estimated to be 220 Bgal, or 675,000 ac-ft, which is 3.1 

times greater than the estimate of Reed and others (1987) and 

5.8 times greater than the estimate of Ash and others (1949). 

For all these estimates, the porosity factor of 0.40, or 40 

percent of the original volume of coalbeds within the flooded 

mine area, is used to account for unmined coal within the 

mine workings (pillars) plus subsidence, backfilling, and other 
Estimated Groundwater Volume and Distribution 39

factors that cause the mine-pool volume (water-filled void 

volume) to be less than the volume of coal and associated rock 

that was originally mined. 

Ash and others (1949) reported that the underground 

mine pools of the Western Middle Anthracite Coalfield 

contained approximately 38 Bgal, or 117,000 ac-ft, of water 

(table 10). For this estimate, Ash and others (1949, p. 41–43) 

multiplied the estimated cumulative thickness of all the 

coalbeds mined within the mine-pool area by the factor of 

0.40. At the time of this estimate, extensive areas were not 

flooded because more than a dozen underground mines were 

using large pumps to dewater the active workings. After these 

remaining mines closed and the abandoned workings filled 

with water, establishing a new groundwater table, Reed and 

others (1987) estimated the underground mines contained 

approximately 71 Bgal, or 218,000 ac-ft, of water. In their 

updated estimate of the volume of the mine pools of the 

Western Middle Anthracite Coalfield, Reed and others (1987) 

adopted the estimates of Ash and others (1949) for collieries where the water level had remained constant from 1949 

to 1975, or increased the volume estimate if the water level 

in 1975 was greater than that in 1949. Although they did not 

explain how the updated volumes were computed, the estimate 

of mine-pool volume by Reed and others (1987) is 38 percent 

of the total volume of underground voids (25 billion cubic 

feet = 187 Bgal) reported for the coalfield. 

The current estimate of the mine-pool volume was 

computed using the groundwater-flow model and a simplified 

conceptual model of the coal-bearing strata and the geologic 

structure of the study area. The preprocessor used for construction of the groundwater-flow model was used as a computational GIS to discretize the coalfield into three-dimensional 

finite difference blocks. The coalbeds and noncoal interbeds 

were included in model layer 3. The cumulative thickness of 

the coalbeds beneath the water table and within the mined 

zone was computed to estimate the mine-pool volume. The 

altitude of the water table, computed by the groundwater 

model described above, is the model-simulated hydraulic head 

in model layer 3 and varies from cell to cell across the area. 

To account for variability in the depth or altitude of the 

mined coal within the study area, only the coalbeds above the 

bottom of the Buck Mountain coalbed (fig. 4) or the deepest 

mining in a MCU (table 4), whichever was a higher altitude, 

were considered. Thus, the mine-pool volume does not include 

mined strata above the water table, and it does not include 

groundwater in deep, unmined strata. 

Although the thicknesses of the coalbeds and strata 

between the coalbeds were assumed to be uniform throughout the study area (table 1), an adjustment factor was used to 

account for variations in the dip of the strata. To convert the 

thickness of a dipping bed to a vertical thickness, the thickness 

was divided by the cosine of the dip angle. For the preliminary calculations presented here, the dip angle was approximated from the generalized structure contours (fig. 4), and 

the assumed dip angle is shown in figure 21. The actual dip is 

highly variable because of the complex geologic structure. A 

refined hydrogeologic model incorporating additional details 

could be constructed from cross sections and mine maps, but 

that effort was beyond the scope of the present study. 

If a porosity factor smaller than 40 percent was used, the 

volume estimate would decrease proportionally. For example, 

Hawkins and Dunn (2007) described a bituminous mine with 

11 percent water-filled porosity, despite reported extraction of 

63 percent of the coal within the mine area. Using a porosity 

factor of 0.11 instead of 0.40, the current estimate of the minepool volume would be 60 Bgal (table 11), which is smaller 

than that estimated by Reed and others (1987). 

Using the estimated volumes and outflow rates for the 

MCUs in the study area, the average estimated groundwater 

residence times within each of the MCUs were estimated to 

range from 0.50 to 6.5 years for a porosity of 0.40 or from 

0.14 to 1.9 years for a porosity factor of 0.11 (table 11). 

Because the residence time is the volume divided by the outflow rate, the residence time for a given outflow rate decreases 

proportionally with the volume or porosity. Reed and others 

(1987) demonstrated that the water discharged from the mines 

in the study area becomes more mineralized as it moves from 

one mine to the next, suggesting progressively longer traveltime and longer contact with rocks. These authors also demonstrated that groundwater within the flooded mines of the study 

area tends to be stratified, with less mineralized (younger) 

water in upper sections and more mineralized (older) water 

in deeper sections of boreholes. Thus, although the average 

residence time is useful to indicate the typical turnover time 

of water stored in a MCU, the actual residence times of the 

molecules of water in any volume may be widely distributed. 

Water residing in the rock matrix, or in low-permeability 

fractures, may be moving very slowly, or only by diffusion, 

whereas water in open voids or high-permeability fractures 

may move many feet in a single day. 

Uncertainty in Estimates of Mine-Pool Volume 

Estimation of the mine-pool volume for the study area 

requires knowledge of the volumetric porosity and the geometric configuration of the flooded mine workings. Uncertainty in 

the data on the volumes of mine voids, the groundwater levels 

in all the mines, and the depth and extent of mining leads to 

uncertainty in the estimate of the mine-pool volume. Ash and 

others (1949) justified an estimate of 0.40 for the water-filled 

fraction of the abandoned mines during the period of active 

mining. However, as explained by Hawkins and Dunn (2007), 

the actual porosity of the flooded, abandoned mine workings 

could be much smaller than initial estimates of coal removed 

because of post-mining subsidence. Thus, given the uncertainty in the porosity factor, the volume of water stored in the 

underground mines is estimated to range from 60 to 220 Bgal. 
40 Water budgets and groundwater volumes for abandoned mines in the Western Middle Anthracite Coalfield, Pa Table 10. Estimated storage volumes and discharges of groundwater by flooded underground mines in the Western Middle Anthracite Coalfield, Schuylkill, Northumberland, and Columbia Counties, Pennsylvania. [MCU, multicolliery unit; AMD, abandoned mine discharge; ft, feet; Mgal, million gallons; ft3/s, cubic feet per second] MCU name Principal colliery name Ash and others (1949) Reed and others (1987) This report, measured1 This report, estimated2 Water level in principal colliery (ft) MCU volume (Mgal) Water level in principal colliery (ft) Discharge to AMD sources (ft3/s) MCU volume (Mgal) Water level in principal colliery (ft) Discharge to AMD sources (ft3/s) Range of water levels in MCU (ft) Discharge to AMD sources (ft3/s) MCU volume (Mgal) Vulcan Vulcan Buck Mountain 1,250 2,396 1,253 7.4 2,543 1,252 8.4 1,262–1,668 10.2 6,721 Gilberton Gilberton 975 6,668 1,102 9.2 9,780 1,100 11.9 1,069–1,198 18.6 11,756 Girard Girard 986 1,424 n.d. 8 1,424 n.d. 3.4 982–1,069 1.1 4,203 Packer Packer No. 5 74 2,796 957 51.6 16,244 956 11.9 969–1,678 15.9 38,730 Centralia Centralia 1000 301 n.d. 11 301 n.d. 3.1 938–1,070 0 1,026 Preston Preston No. 3 948 571 n.d. 2.6 571 n.d. 1.5 934–963 1.3 2,764 Bast Bast 757 3,679 908 7.5 3,679 908 1.5 903–1,005 14.2 8,701 Potts & Tunnel Potts 251 653 999 4.8 794 1,002 1.37 904–1,000 0 14,603 Locust Gap Locust Gap 1,173 145 892 17.4 1,750 n.d. 14.5 713–1,011 31.7 10,305 Midvalley Midvalley Nos. 3 and 4 1,212 490 1,212 6.5 489 n.d. 5.5 1,072–1,403 2.7 3,545 Scott Scott and Scott Ridge 886 7,142 999 17.8 8,128 1,000 17.5 963–1,144 0 30,809 Maysville-Corbin Maysville Nos. 1 & 2 333 2,102 855 3.3 13,319 852 17.3 789–1,037 12.3 25,040 Cameron Cameron 443 2,251 714 9.8 3,880 736 7.6 680–1,060 21.4 24,151 Big Mountain Big Mountain 869 823 n.d. 2 825 n.d. 2.1 790–900 0 3,319 Stirling Henry Clay - Stirling 770 5,208 778 11.2 5,213 780 8.7 763–889 14.6 23,679 North Franklin North Franklin 870 1,597 870 8.3 1,597 873 4.5 848–891 3.2 7,805 Morea Morea n.d. n.d. n.d. n.d. n.d. n.d. n.d. 1,433–1,559 0 2,679 TOTAL: 38,245 197 70,538 120.8 147.3 219,835

1 Measured values based on average water levels or sum of discharges for MCU (see tables 5 and 6).2 Estimated values based on results of preliminary, calibrated steady-state model of groundwater flow for the study area.
Estimated Groundwater Volume and Distribution 41

Default dip angle is 30 degrees

Uniform dip angle inside contours

Figure 21. Generalized dip angles for use in estimating mine-pool volumes using a hydrogeologic model for the Western Middle 

Anthracite Coalfield, Schuylkill, Columbia, and Northumberland Counties, Pennsylvania. This screenshot of the model preprocessor 

shows uniform dip angle zones and the color map is the altitude of the bottom of the Buck Mountain Formation from low (blue shading) 

to high (red shading). 

Table 11. Estimated storage volumes and average residence times of groundwater in the mine pools considering different porosities 

for mined coalbeds in the Western Middle Anthracite Coalfield, Schuylkill, Northumberland, and Columbia Counties, Pennsylvania, 

1999–2001.

[MCU, multicolliery unit; ft3/s, cubic feet per second; Bgal, billion gallons; yr, year]

MCU name

Total 

outflow 

rate 

(cfs)

Outflow rate to: Porosity factor = 0.40 Porosity factor = 0.11

Wells 

(ft3/s)

Mine 

discharges 

(ft3/s)

Other 

MCUs or 

aquifer 

(ft3/s)

Mine water 

volume 

(Bgal)

Average 

residence 

time of water 

(yr)

Mine water 

volume 

(Bgal)

Average 

residence 

time of water 

(yr)

Vulcan 15.34 0 10.16 5.18 6.7 1.9 1.9 0.5

Packer 51.51 1.83 15.91 33.77 38.7 3.2 10.7 0.9

Girard 6.21 0 1.09 5.12 4.2 2.9 1.2 0.8

Gilberton 36.01 2.67 18.62 14.72 11.8 1.4 3.2 0.4

Centralia 9.61 0 0 9.61 1 0.5 0.3 0.1

Bast 18.29 0 14.24 4.05 8.7 2 2.4 0.6

Preston 2.99 0 1.31 1.68 2.8 3.9 0.8 1.1

Midvalley 6.85 0 2.73 4.12 3.5 2.2 1 0.6

Potts & Tunnel 9.01 0 0 9.01 14.6 6.9 4 1.9

Scott 33.02 0 0 33.02 30.8 4 8.5 1.1

Locust Gap 39.46 0 31.68 7.78 10.3 1.1 2.8 0.3

Maysville-Corbin 40.91 0 12.27 28.64 25 2.6 6.9 0.7

Cameron 48.88 0 21.45 27.43 24.2 2.1 6.6 0.6

Big Mountain 4.74 0 0 4.74 3.3 3 0.9 0.8

Stirling 33.31 0 14.64 18.67 23.7 3 6.5 0.8

North Franklin 5.92 0 3.22 2.7 7.8 5.6 2.2 1.5

Morea 4.3 0.89 0 3.41 2.7 2.6 0.7 0.7

TOTAL 366.36 5.39 147.32 213.65 219.8 60.5
42 Water budgets and groundwater volumes for abandoned mines in the Western Middle Anthracite Coalfield, Pa

Alternative Method for Determining Volume 

An alternative method for characterizing storage properties of the mine complex including the porosity would be 

through calibration of a transient model of groundwater flow 

(Goode and Senior, 2000; Sahu and others, 2009). Changes 

in hydrologic conditions, such as changes in pumping rate of 

a well, will cause changes in water levels in the aquifer. The 

magnitude and rate of water-level changes are dependent on 

the flow properties, such as hydraulic conductivity, and the 

storage properties, generally the storage coefficient. Thus, 

calibration of a transient model to measured water levels after 

a change in pumping rate can identify both the hydraulic conductivity and the storage coefficient. This is conceptually the 

same as use of the Theis equation to estimate hydraulic conductivity and storage coefficient from analysis of water-level 

drawdown after a step change in pumping rate (for example, 

Freeze and Cherry, 1979; Driscoll, 1986; Kruseman and de 

Ridder, 1990). 

The storage coefficient is the ratio of the change of water 

volume in a unit volume of aquifer divided by the change in 

water level or hydraulic head. Under confined conditions, the 

storage coefficient is small and reflects the storage of water by 

compression of the solid matrix of the aquifer, which causes 

an increase in the volumetric porosity. Under unconfined or 

water-table conditions, the storage coefficient is the specific 

yield, which approximates the porosity for coarse-grained 

porous media. In this case, water is stored by the filling of pore 

space above the water table as that surface rises. The storage 

coefficient for unconfined conditions is generally orders of 

magnitude larger than that for confined conditions. 

In a flooded coal mine in dipping strata, the water table 

occurs at a “beach” where the mine voids above this level are 

filled with air and the voids below this level are filled with 

water (fig. 22). As the groundwater level rises, void space is 

filled with water. The storage coefficient is large at the beach, 

reflecting the ratio of voids to solid rock, and very small below 

the beach level where the workings are already saturated. In 

addition, storage between the mined layers is small because of 

the small primary porosity and low hydraulic conductivity of 

the unmined rocks. In the schematic illustration (fig. 22), the 

area of the multicolliery aquifer system that can effectively 

store water at the water table in the mine pool is a small part of 

the total area. In the case of the multicolliery mine complexes 

in the Western Middle Anthracite Coalfield, the overall storage coefficient would reflect all the beaches that occur in the 

interconnected mine workings within the MCU. 

Analogous to conducting an aquifer test, data collection 

for use in a model for estimation of storage properties would 

include continuous water levels and measurement of pumping rates and other discharges such as streams. Ideally, the 

aquifer system would be relatively stable for an antecedent 

time period. The pumping rate could then be changed and held 

constant for several days. On the basis of the model results 

presented here, measurable water-level changes for such a test 

would only occur in the well-connected voids within a single 

MCU. Calibration of a transient groundwater-flow model to 

such data could provide an estimate of the overall storage 

coefficient for the MCU. This would characterize the rate of 

change in volume of water stored per unit change in water 

level. Integrating this over the total mine from the lowest 

mined level to the current water level would yield the total 

volume of water stored in the MCU. 

Identification of Data Needs 

The following data needs are identified for improving the 

understanding of regional groundwater flow in the Western 

Middle Anthracite Coalfield. Portions of this section are drawn 

directly from the report by Risser (2006), which describes a 

similar study including identification of data needs.

1. Continuous streamflow and mine-discharge monitoring—Long-term continuous monitoring of streamflow in 

Shamokin and Mahanoy Creeks would provide a record 

of the response of the basins to natural climate and landuse changes. Continuous monitoring captures events, such 

as storms, that are impossible to record with synoptic 

measurements. Streamgages installed as pairs upstream 

and downstream from segments that gain base flow from 

multiple or diffuse mine discharges or that are prone to 

leakage would allow a determination of gains and losses 

between streamgages.

2. Synoptic streamflow and mine-discharge measurements—The simulated effect of a large pumping well 

on the groundwater system is related to the potential for 

groundwater discharges and streamflow to be captured. 

Data used for calibration of the model were collected during a period when the pump in the Gilberton Mine shaft 

was not being operated. Measurements of streamflow 

and mine discharges during periods of pumping near the 

average annual base-flow conditions would provide better 

flow targets for adjusting parameters in the steady-state 

model. 

3. Water-level data—Synoptic measurements of groundwater levels in boreholes and wells in areas bordering the 

mine pools would improve knowledge of the water-table 

configuration and provide better groundwater-level data 

for model adjustments. Ideally, the altitudes of all wells 

should be surveyed so that an accurate datum is available. Continuous monitoring of water levels in wells near 

streams and groundwater extraction sites would provide a 

record of the transient response to natural and anthropogenic events.
Identification of Data Needs 43

Area of water table

storage capacity

“Beach” at altitude of

Mine Pool groundwater table

M

I

N

E

D

C O A L B E D

M

I N E D

C O A L B E D

Discharging

shaft

L a n d

s u r f a c e

Not to scale

Water table

Figure 22. Schematic cross section of flooded mine complex showing the groundwater table in overlying, mined coalbeds 

and the portion of the surface area of the mined coalbed where water-table storage capacity is effective. For practical 

purposes, the porosity of unmined strata surrounding the mined coalbeds is considered negligible compared to that of the 

mined coalbed. Any change in water-table elevation reflects differences in the available storage capacity of the mined 

coalbed, which varies as a function of the geologic structure (geometry).
44 Water budgets and groundwater volumes for abandoned mines in the Western Middle Anthracite Coalfield, Pa

4. Water-use data—Incorporation of historical water withdrawals and discharges would provide a more complete 

accounting of all terms in the basin water budget. Other 

data on groundwater pumping for industrial supply and 

streamflow could be incorporated.

5. Streambed surveys—Surveys of the changes in streamflow and hydraulic gradient beneath stream channels 

would help establish the extent of gaining and losing 

reaches under differing hydrologic conditions and season. 

These surveys can be conducted with a potentiomanometer as described by Winter and others (1988). 

6. Tracer studies—Tracer studies are the best method for 

determining the direction and velocity of groundwater 

flow. Tracer studies could be conducted on losing reaches 

of tributaries to Mahanoy Creek or at individual cropfalls 

or other loss points identified as possible contributing 

areas for water extracted from the mine pool. 

7. Continuous groundwater measurements during 

stepped pumping tests or recharge events—Continuous 

measurements of changes in groundwater levels during 

short-term, transient events would support the calibration of transient simulations to provide an independent 

estimate of mine-pool storage capacity.

The additional measurements and analysis during transient 

conditions would help to determine water storage, improve 

simulations of water budgets, and evaluate the relation 

between groundwater and surface water. 

Summary

Streamflow and mine-discharge data were evaluated relative to contributing areas to explore possible relations between 

surface water and groundwater in the 120-mi2 area of the 

Western Middle Anthracite Coalfield. Within this area, a total 

of 24 coalbeds, with average thicknesses from 2.0 to 7.4 ft, 

have been mined to depths exceeding 2,500 ft below land surface. Most of the coal was removed by underground-mining 

methods that created an extensive network of interconnected 

underground voids separated by unmined coal barriers along 

mine boundaries. After closure, low-lying sections of the mine 

workings flooded, creating vast underground mine pools that 

discharge to the surface at topographically low points or from 

abandoned drainage tunnels. 

The Mahanoy and Shamokin Creek Basins were the focus 

of the study because these basins exhibit extensive hydrologic 

effects and water-quality degradation from the abandoned 

mines in their headwaters in the Western Middle Anthracite 

Coalfield. Base-flow yields on the basis of synoptic streamflow measurements in 1999–2001 indicate that upstream parts 

of Mahanoy and Shamokin Creeks lose water to the underground mines, but adjacent or downstream sections of Mahanoy and Shamokin Creeks gain base flow. Stream locations 

with anomalously large yields capture recharge from adjacent 

basins through the mine pools. 

On the basis of mapped mine boundaries, measured 

groundwater levels, and measured discharge volumes for large 

sources of abandoned mine drainage (AMD), the 69 mapped 

mines were grouped as 17 named mine pools or multicolliery hydrologic units (MCUs). The mines that were grouped 

as a single MCU generally exhibited similar groundwater 

levels consistent with a high degree of horizontal and vertical 

interconnections and high permeability. Intact barrier pillars or 

unmined rock with low permeability separates the MCUs and 

helps focus groundwater discharge to one or more large AMD 

outflows associated with each MCU. 

A three-dimensional steady-state groundwater-flow 

model and an associated geographic information system were 

used to integrate data on the mining features, hydrogeology, 

and streamflow in the Western Middle Anthracite Coalfield. 

The preliminary model has very few parameters and does 

not reflect the actual spatial variability of aquifer properties 

but was used to test the multicolliery hydrologic model and 

to illustrate the use of porous-media approximations for this 

highly complex groundwater system. The numerical groundwater model was developed using MODFLOW-2000 and calibrated to measured water levels and stream base flow, the latter composed primarily of mine discharge at many locations. 

The calibrated model was used to evaluate the movement of 

groundwater among adjacent mines. Preliminary simulations 

were conducted for (1) current conditions and (2) a water table 

lowered by expanded pumping from the Gilberton Mine pool. 

Expansion of pumping at Gilberton will lower the water levels, especially close to Gilberton. The simulated water budget 

indicates that most of the additional pumping is balanced by a 

reduction in discharges from mines to streams. The simulated 

groundwater levels illustrate shallow groundwater gradients 

within an MCU and abrupt changes in water levels between 

MCUs. Given the simulated groundwater levels, depth of mining, and porosity estimates ranging from 11 to 40 percent for 

the mined rocks, the water volume in storage in the mines was 

estimated to range from 60 to 220 Bgal, respectively. 

The calibrated model supports the conceptual model of 

the high-permeability MCUs separated by low-permeability 

barriers and streamflow losses and gains associated with 

mine-pool infiltration and discharge. However, details of the 

water-level distribution and the locations and rates of some 

discharges are not well simulated using the preliminary model. 

Although example model adjustments showed that improvements in the model calibration were possible by introducing 

spatial variability in permeability parameters and adjusting barrier properties, more detailed parameterizations have 

increased uncertainty because of the limited data set. The 

preliminary model results indicate that the primary result of 
References Cited 45

increased pumping from the mine pool would be reduced mine 

discharge to streams near the pumping wells. The intact barriers limit the spatial extent of mine dewatering. The model and 

associated estimate of mine-pool volume could be improved 

with additional water-level and streamflow measurements. 

Water budgets and mine pool volume estimates could be 

improved with additional hydrologic data including streamflow, mine discharge rates, water levels in mines and other 

parts of the groundwater system, and water-use data. Streamflow, mine discharge, and water levels can be measured continuously with available technology, and such data could substantially improve the understanding of hydraulic connections 

between mine areas, especially in combination with changes 

in pumping or large recharge events. Use of transient simulations, calibrated with transient measurements, is suggested to 

provide an independent estimate of mine-pool storage capacity. Streambed surveys and tracer studies could provide additional information about groundwater/surface-water exchanges 

and the impact of mine voids on base-flow generation. 

References Cited

21st Century Environment Commission, 1998, Report of the 

Pennsylvania 21st Century Environment Commission: 

Pennsylvania Department of Environmental Protection, 92 

p., accessed April 6, 2010, at http://www.21stcentury.state.

pa.us/2001/report.pdf.

Arndt, H.H., Danilchik, Walter, and Wood, G.H., Jr., 1963a, 

Geology of anthracite in the western part of the Shamokin 

quadrangle, Northumberland County, Pennsylvania: U.S. 

Geological Survey Coal Investigations Map C-47.

Arndt, H.H., Wood, G.H., Jr., and Danilchik, Walter, 1963b, 

Geology of anthracite in the southern part of the Trevorton 

quadrangle, Northumberland County, Pennsylvania: U.S. 

Geological Survey Coal Investigations Map C-48.

Ash, S.H., Eaton, W.L., Hughes, K., Romischer, W.M., and 

Westfield, J., 1949, Water pools in Pennsylvania anthracite 

mines: U.S. Bureau of Mines Technical Paper 727, 78 p. 

Ash, S.H., Hower, C.S., Kennedy, D.O., and Lesser, W.H., 

1953b, Mine pumping plants, Anthracite region of Pennsylvania: U.S. Bureau of Mines Bulletin 531, 151 p. 

Ash, S.H., Kennedy, D.O., Link, H.B., and Romischer, W.M., 

1953a, Barrier pillars in the Western Middle Field: U.S. 

Bureau of Mines Bulletin 521, 92 p. 

Ash, S.H., and Link, H.B., 1953, Surface-water seepage into 

anthracite mines in the Western Middle Field: U.S. Bureau 

of Mines Bulletin 532, 26 p. 

Becher, A.E., 1991, Groundwater resources in and near the 

anthracite basins of Schuylkill and adjacent counties, Pennsylvania: Pennsylvania Geological Survey, 4th ser., Water 

Resources Report 64, 59 p., 1 plate.

Berg, T.M., Barnes, J.H., Seven, W.D., Skema, V.K., Wilshusen, J.P., and Yannicci, D.S., 1989, Physiographic provinces 

of Pennsylvania: Pennsylvania Geological Survey, 4th ser., 

Map 13, scale 1:2,000,000. 

Berg, T.M., Edmunds, W.E., Geyer, A.R., Glover, A.D., 

Hoskins, D.M., MacLachlan, D.B., Root, S.I., Sevon, W.D., 

and Socolow, A.A., comps., 1980, Geologic map of Pennsylvania: Pennsylvania Geological Survey, 4th ser., Map 1, 

scale 1:250,000, 3 sheets.

Callaghan, Thomas, Fleeger, G.M., Barnes, Scott, and Dalberto, Albert, 1998, Groundwater flow on the Appalachian 

Plateau of Pennsylvania, in Brady, K.B.C., Smith, M.W., 

and Schueck, J., eds., Coal mine drainage prediction and 

pollution prevention in Pennsylvania: Pennsylvania Department of Environmental Protection, 5600-BK-DEP2256, 

p. 2.1–2.39. 

Carleton, G.B., and Gordon, A.D., 2007, Hydrogeology of, 

and simulation of ground-water flow in, the Pohatcong Valley, Warren County, New Jersey: U.S. Geological Survey 

Scientific Investigations Report 2006–5269, 66 p.

Cravotta, C.A., III, 2005, Effects of abandoned coal-mine 

drainage on streamflow and water quality in the Mahanoy 

Creek basin, Schuylkill, Columbia, and Northumberland 

Counties, Pennsylvania, 2001: U.S. Geological Survey 

Scientific Investigations Report 2004–5291, 60 p., 

4 appendixes. 

Cravotta, C.A., III, and Kirby, C.S., 2004, Effects of abandoned coal-mine drainage on streamflow and water quality 

in the Shamokin Creek basin, Northumberland and Columbia Counties, Pennsylvania, 1999–2001: U.S. Geological 

Survey Water-Resources Investigations Report 03–4311, 

58 p. 

Danilchik, Walter, Arndt, H.H., and Wood, G.H., Jr., 1962, 

Geology of anthracite in the eastern part of the Shamokin 

quadrangle, Northumberland County, Pennsylvania: U.S. 

Geological Survey Coal Investigations Map C-46.

Danilchik, Walter, Rothrock, H.E., and Wagner, H.C., 1955, 

Geology of anthracite in the western part of the Shenandoah 

quadrangle, Pennsylvania: U.S. Geological Survey Coal 

Investigations Map C-21.

Driscoll, F.G., 1986, Groundwater and wells (2nd ed.): St. 

Paul, Minn., Johnson Division, 1,089 p.
46 Water budgets and groundwater volumes for abandoned mines in the Western Middle Anthracite Coalfield, Pa

Eggleston, J.R., Kehn, T.M., and Wood, G.H., Jr., 1999, 

Anthracite, in Schultz, C.H., ed., The geology of Pennsylvania: Pennsylvania Geological Survey, 4th series, Special 

Publication 1, p. 458–469. 

Freeze, R.A., and Cherry, J.A., 1979, Groundwater: Englewood Cliffs, N.J., Prentice-Hall, Inc., 604 p.

Gannett Fleming Corddry and Carpenter, Inc., 1972, Operation Scarlift project no. SL-113—Mine drainage abatement 

measures for the Shamokin Creek Watershed: Harrisburg, 

Pa., Gannett Fleming Corddry and Carpenter, Inc.

Goode, D.J., and Senior, L.A., 2000, Simulation of aquifer tests and groundwater flowpaths at the local scale in 

fractured shales and sandstones of the Brunswick Group 

and Lockatong Formation, Lansdale, Montgomery County, 

Pennsylvania: U.S. Geological Survey Open-File Report 

00–97, 46 p.

Growitz, D.J., Reed, L.A., and Beard, M.M., 1985, Reconnaissance of mine drainage in the coal fields of eastern Pennsylvania: U.S. Geological Survey Water-Resources Investigations Report 83–4274, 54 p.

Haley, B.R., Arndt, H.H., Rothrock, H.E., and Wagner, H.C., 

1953, Geology of anthracite in the western part of the 

Ashland quadrangle, Pennsylvania: U.S. Geological Survey 

Coal Investigations Map C-13. 

Haley, B.R., Arndt, H.H., Rothrock, H.E., and Wagner, H.C., 

1954, Geology of anthracite in the eastern part of the 

Ashland quadrangle, Pennsylvania: U.S. Geological Survey 

Coal Investigations Map C-14.

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

M.G., 2000, MODFLOW-2000, the U.S. Geological Survey 

modular groundwater flow model—User guide to modularization concepts and the groundwater flow process: U.S. 

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

Harlow, G.E., Jr., and LeCain, G.D., 1993, Hydraulic characteristics of, and ground-water flow in, coal-bearing rock 

of southwestern Virginia: U.S. Geological Survey WaterSupply Paper 2388, 37 p. 

Hawkins, J.W., and Dunn, M., 2007, Hydrologic characteristics of a 35-year-old underground mine pool: Mine Water 

and the Environment, v. 26, p. 150–159.

Hill, M.C., Banta, E.R., and Harbaugh, A.W., 2000, MODFLOW-2000, the U.S. Geological Survey modular 

groundwater flow model—User guide to the observation, 

sensitivity, and parameter-estimation processes and three 

post-processing programs: U.S. Geological Survey OpenFile Report 00–184, 209 p.

Hsieh, P.A., and Freckleton, J.R., 1993, Documentation of a 

computer program to simulate horizontal-flow barriers using 

the U.S. Geological Survey modular three-dimensional 

finite-difference ground-water flow model: U.S. Geological 

Survey Open-File Report 92–477, 32 p.

Kehn, T.M., and Wagner, H.C., 1955, Geology of anthracite in 

the eastern part of the Shenandoah quadrangle, Pennsylvania: U.S. Geological Survey Coal Investigations Map C-19.

Kruseman, G.P., and de Ridder, N.A., 1990, Analysis and 

evaluation of pumping test data: Wageningen, the Netherlands, International Institute for Land Reclamation and 

Improvement, Publication 47, 377 p.

Lewis-Brown, J.C., Rice, D.E., Rosman, Robert, and Smith, 

N.P., 2005, Hydrogeological framework, ground-water quality, and simulation of ground-water flow at the Fair Lawn 

Well Field superfund site, Bergen County, New Jersey: 

U.S. Geological Survey Scientific Investigations Report 

2004–5280, 109 p.

Marsh, Ben, 1987, Continuity and decline in the anthracite 

towns of Pennsylvania: Annals of the Association of American Geographers, v. 77, p. 337–352. 

Maxwell, J.A., and Rothrock, H.E., 1955, Geology of anthracite in the western part of the Delano quadrangle, Pennsylvania: U.S. Geological Survey Coal Investigations Map 

C-25.

McCoy, K.J., Donovan, J.J., and Leavitt, B.R., 2006, Horizontal hydraulic conductivity estimates for intact coal barriers between closed underground mines: Environmental & 

Engineering Geoscience, v. 12, no. 3, p. 273–282.

National Climatic Data Center, 2010, U.S. Department of 

Commerce, National Environmental Satellite, Data, and 

Information Service, accessed February 22, 2010, at http://

www.ncdc.noaa.gov/oa/ncdc.html.

Pollock, D.W., 1994, User’s guide for MODPATH/MODPATH-PLOT, VERSION 3—A particle tracking postprocessing package for MODFLOW, the U.S. Geological 

Survey finite-difference groundwater flow model: U.S. 

Geological Survey Open-File Report 94–464, 249 p.

Prudic, D.E., 1989, Documentation of a computer program to 

simulate stream-aquifer relations using a modular, finite-difference, groundwater flow model: U.S. Geological Survey 

Open-File Report 88–729, 113 p.

Reed, L.A., Beard, M.M., and Growitz, D.J., 1987, Quality of 

water in mines in the western middle coal field, anthracite 

region, east-central Pennsylvania: U.S. Geological Survey 

Water-Resources Investigations Report 64, 51 p.
References Cited 47

Risser, D.W., 2006, Simulated water budgets and groundwater/surface-water interactions in Bushkill and parts 

of Monocacy Creek watersheds, Northampton County, 

Pennsylvania—A preliminary study with identification 

of data needs: U.S. Geological Survey Open-File Report 

2006–1143, 31 p.

Risser, D.W., Conger, R.W., Ulrich, J.E., and Asmussen, M.P., 

2005, Estimates of groundwater recharge based on streamflow-hydrograph methods—Pennsylvania: U.S. Geological 

Survey Open-File Report 2005–1333, 30 p.

Rothrock, H.E., Wagner, H.C., and Haley, B.R., 1950, Geology of anthracite in the west-central part of the Mount 

Carmel quadrangle, Pennsylvania: U.S. Geological Survey 

Investigations Map C-3.

Rothrock, H.E., Wagner, H.C., Haley, B.R., and Arndt, H.H., 

1951a, Geology of anthracite in the southwestern part of the 

Mount Carmel quadrangle, Pennsylvania: U.S. Geological 

Survey Investigations Map C-7.

Rothrock, H.E., Wagner, H.C., Haley, B.R., and Arndt, H.H., 

1951b, Geology of anthracite in the east-central part of the 

Mount Carmel quadrangle, Pennsylvania: U.S. Geological 

Survey Coal Investigations Map C-10.

Rothrock, H.E., Wagner, H.C., Haley, B.R., and Arndt, H.H., 

1953, Geology of anthracite in the southeastern part of the 

Mount Carmel quadrangle, Pennsylvania: U.S. Geological 

Survey Coal Investigations Map C-12.

Rutledge, A.T., 1998, Computer programs for describing the 

recession of ground-water discharge and for estimating 

mean ground-water recharge and discharge from streamflow 

data—Update: U.S. Geological Survey Water-Resources 

Investigations Report 98–4148, 43 p. 

Saad, D.A., and Cravotta, C.A., III, 1991, Modeling of 

ground-water flow along a cross section through a reclaimed 

surface coal mine in western Pennsylvania (abs.), in Proceedings of the 1991 National Meeting of the American 

Society for Surface Mining and Reclamation, May 14-17, 

1991, Durango, Co.: Princeton, W.Va., American Society for 

Surface Mining and Reclamation, p. 545. (Also available at 

http://www.techtransfer.osmre.gov/NTTMainSite/Library/

proceed/asmr91/session6.pdf)

Sahu, Parameswar, Lopez, D.L., and Stoertz, M.W., 2009, 

Using time series analysis of coal mine hydrographs to 

estimate mine storage, retention time, and mine-pool 

interconnection: Mine Water and the Environment, v. 28, 

p. 194–205.

Sanders & Thomas, Inc., 1975, Operation Scarlift project no. 

SL-197, Mahanoy Creek mine drainage pollution abatement 

project: Harrisburg, Pa., Sanders & Thomas, Inc. Engineers, 

125 p., 1 appendix, 2 plates. 

Susquehanna River Basin Commission, 2005, WMPI PTY, 

L.L.C.—Groundwater withdrawal of 7.000 mgd (30-day 

average) and consumptive water use of up to 3.470 mgd 

(peak day) for the gasification and liquefaction of coal 

waste, and for the ancillary generation of steam and electricity, Mahanoy and West Mahanoy Townships, Schuylkill 

County, Pennsylvania: Docket No. 20050905, September 

14, 2005, accessed April 21, 2010, at http://www.srbc.net/

wrp/Details.aspx?ID=3065.

U.S. Geological Survey, 2004, National elevation data set, 

accessed April 4, 2009, at http://ned.usgs.gov/.

U.S. Geological Survey, 2009, Pennsylvania StreamStats, 

accessed November 22, 2009, at http://water.usgs.gov/osw/

streamstats/pennsylvania.html.

Veil, J.A., Kupar, J.M., and Puder, M.G., 2003, Use of mine 

pool water for power plant cooling: Argonne National Laboratory, final report to U.S. Department of Energy National 

Energy Technology Laboratory under contract W-31-109-

Eng-38: 62 p., accessed February 20, 2010, at http://www.

netl.doe.gov/technologies/coalpower/ewr/pubs/mine%20

pool%20report%20FINAL_1.pdf)

Winston, R.B., 2000, Graphical user interface for MODFLOW, Version 4: U.S. Geological Survey Open-File 

Report 00–315, 27 p.

Winter, T.C., LaBaugh, J.W., and Rosenberry, D.O., 1988, The 

design and use of a hydraulic potentiomanometer for direct 

measurement of differences in hydraulic head between 

groundwater and surface water: Limnology and Oceanography, v. 33, no. 5, p. 1,209–1,214.

Wood, C.R., 1996, Water quality of large discharges in the 

anthracite region of eastern Pennsylvania: U.S. Geological 

Survey Water-Resources Investigations Report 95–4243, 

68 p.

Wood, G.H., Jr., Kehn, T.M., and Eggleston, J.R., 1986, Deposition and structural history of the Pennsylvania Anthracite 

region, in Lyons, P.C., and Rice, C.L., eds., Paleoenvironmental and tectonic controls in coal-forming basins of the 

United States: Geological Society of America Special Paper 

210, p. 

Wyrick, G.G., and Borchers, J.W., 1981, Hydrologic effects 

of stress-relief fracturing in an Appalachian valley: U.S. 

Geological Survey Water-Supply Paper 2177, 51 p.
48 Water budgets and groundwater volumes for abandoned mines in the Western Middle Anthracite Coalfield, Pa

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 49

Tables 3 and 5
50 Water budgets and groundwater volumes for abandoned mines in the Western Middle Anthracite Coalfield, Pa

Table 3. Site descriptions and flow rates of abandoned mine discharges in the Western Middle Anthracite Coalfield, Schuylkill, 

Columbia, and Northumberland Counties, Pennsylvania, 1999–2001.—Continued

[USGS, U.S. Geological Survey; ft, feet above National Geodetic Vertical Datum of 1929; ft3/s, cubic feet per second; colored shading identifies sites with 

maximum discharge greater than 1 ft3/s and are considered in numerical flow model: yellow, Shamokin Creek; green, Mahanoy Creek; red, Schuylkill River]

Local 

identification 

number

Local name USGS station 

number Latitude Longitude Altitude (ft)

Discharge1

Minimum 

(ft3/s)

Maximum 

(ft3/s)

Shamokin Creek Basin

SR01 N Branch Shamokin Creek at Aristes 01554200 40.8247 -76.3576 1,760 0.01 0.2

SR02 Mid Valley Mine seep 404917076222101 40.8218 -76.3727 1,520 0.04 0.1

SR03 Unn Trib to N Branch Shamokin Creek 01554220 40.8221 -76.3735 1,520 0.01 0.08

SR04 Mid Valley Mine Tunnel 4 404905076235501 40.8181 -76.3990 1,290 0.5 1.3

SR05A Mid Valley Mine Tunnel overflow 01554260 40.8137 -76.4042 1,220 0 1.4

SR05B Mid Valley Mine Tunnel 404848076242401 40.8135 -76.4060 1,220 2.7 5

SR06 Sayre-Sioux Mine discharge 404757076231201 40.7992 -76.3867 1,200 0.02 0.02

SR08 Locust Gap Mine discharge SR08 404546076270201 40.7631 -76.4507 1,280 0 0.68

SR10 Locust Gap Mine discharge SR10 404554076264701 40.7650 -76.4466 1,260 0.01 0.04

SR11 Alaska Mine seep 404656076265001 40.7822 -76.4474 1,060 0 0.25

SR12 Excelsior Mine pit overflow 404625076293701 40.7738 -76.4934 970 7.2 14

SR13 Locust Gap Mine seep SR13 404549076295301 40.7635 -76.4981 1,440 0.02 0.02

SR15 Corbin Water Level Drift 404646076305301 40.7795 -76.5142 890 0.92 2.5

SR19 Scott Ridge Mine Tunnel 404739076291901 40.7921 -76.4891 1,000 9.4 19

SR20 Colbert Mine breach 404726076294101 40.7907 -76.4967 970 1.6 1.9

SR21 Maysville Mine Borehole 404703076305201 40.7842 -76.5176 850 0.56 4.3

SR22A Royal Oak Mine seep SR22A 404657076320501 40.7824 -76.5350 790 0.01 0.22

SR22B Royal Oak Mine seep SR22B 404657076320502 40.7824 -76.5348 790 0.01 0.9

SR23 Big Mountain Mine No. 1 slope 404619076321901 40.7714 -76.5376 970 0.51 3.6

SR28 Henry Clay Stirling Mine seep SR28 404634076322301 40.7761 -76.5397 800 0.01 0.14

SR29 Royal Oak Mine discharge 404643076323801 40.7788 -76.5439 880 0.26 0.5

SR30 Royal Oak Mine seep SR30 404641076323701 40.7781 -76.5439 790 0.01 0.01

SR31-3 Greenough Mine discharge 404838076281001 40.8107 -76.4695 1,300 0.01 0.04

SR36A Luke Fiddler Mine discharge 404725076323501 40.7905 -76.5431 800 0 0

SR36B Royal Oak Mine discharge SR36B 404724076324201 40.7903 -76.5452 750 0.01 0.02

SR37 Bear Valley Mine discharge SR37 404631076373001 40.7755 -76.6253 1,110 0 0.01

SR38A Bear Valley Mine seep SR38A 404754076372801 40.7817 -76.6255 1,180 0.03 0.04

SR39 Bear Valley strip pool overflow 404642076373001 40.7785 -76.6248 1,010 0.01 0.07

SR40B Bear Valley Mine discharge SR40B 404636076373501 40.7770 -76.6266 1,020 0 0.04

SR40C Bear Valley Mine discharge SR40C 404637076373401 40.7772 -76.6261 1,020 0.01 0.08

SR41 KMK Coal Co. No. 14 404622076364601 40.7730 -76.6129 910 0 0.01

SR42 Bear Valley Mine N Mtn Tunnel 404618076365901 40.7720 -76.6157 930 0.4 1.1

SR43 Bear Valley Mine discharge SR43 404618076361001 40.7718 -76.6030 940 0 0.04
Table 3. Site descriptions and flow rates 51

Table 3. Site descriptions and flow rates of abandoned mine discharges in the Western Middle Anthracite Coalfield, Schuylkill, 

Columbia, and Northumberland Counties, Pennsylvania, 1999–2001.—Continued

[USGS, U.S. Geological Survey; ft, feet above National Geodetic Vertical Datum of 1929; ft3/s, cubic feet per second; colored shading identifies sites with 

maximum discharge greater than 1 ft3/s and are considered in numerical flow model: yellow, Shamokin Creek; green, Mahanoy Creek; red, Schuylkill River]

Local 

identification 

number

Local name USGS station 

number Latitude Longitude Altitude (ft)

Discharge1

Minimum 

(ft3/s)

Maximum 

(ft3/s)

Shamokin Creek Basin

SR44 Bear Valley Mine discharge SR44 404628076361201 40.7746 -76.6036 890 0.02 0.02

SR45 Henry Clay Stirling Mine discharge 404625076352701 40.7737 -76.5909 850 0 0.01

SR46 Bear Valley Mine seep SR46 404614076351101 40.7709 -76.5870 850 0.01 0.2

SR47 Bear Valley Mine discharge SR47 404614076351001 40.7708 -76.5862 850 0 0.03

SR48 Henry Clay Stirling Mine seep SR48 404643076344701 40.7790 -76.5789 900 0.02 0.2

SR49 Henry Clay Stirling Mine pump slope 404037076340701 40.7773 -76.5681 790 1.6 13

SR51 Cameron Mine discharge SR51 404731076334601 40.7938 -76.5650 730 0.02 0.67

SR51A Cameron Mine Drift 404737076335501 40.7938 -76.5647 710 1.2 2.3

SR52 Cameron Mine discharge SR52 404735076333401 40.7939 -76.5650 730 0.14 0.14

SR53 Cameron Mine Air Shaft 404744076335901 40.7964 -76.5657 710 2.3 5

SR54 Cameron Mine seep 404748076335701 40.7968 -76.5660 800 0.01 0.01

SR55 Richards Shaft Mine Drift 404817076261201 40.8056 -76.4350 1,070 0 6.6

SR56 Mid Valley Mine discharge 404848076241801 40.8134 -76.4052 1,220 0 0.01

Mahanoy Creek Basin

M01 Vulcan-Buck Mountain Mine Morris Tunnel 404916076071701 40.8160 -76.1237 1,290 0 0

M02 Vulcan-Buck Mountain Mine seepage 404858076072501 40.8160 -76.1237 1,290 0 8.79

M03 Vulcan-Buck Mountain Mine boreholes 404855076073501 40.8154 -76.1260 1,259 2.64 5.28

M04 Gilberton Mine Pump2 404801076123401 40.8004 -76.2091 1,135 0 10.83

M05 Weston Mine surface areas seepage 404830076144901 40.8084 -76.2466 1,030 0 0.01

M07 Weston Mine Lost Cr borehole 404825076144901 40.8070 -76.2466 1,030 0.03 0.38

M08 Hammond Mine Seepage 404805076162001 40.8007 -76.2725 1,000 0 0.27

M09 Hammond Mine Connerton Village boreholes3 404806076160401 40.8017 -76.2678 990 0 2.3

M11 Girard Mine seepage 404730076160601 40.7918 -76.2680 1,005 2.73 4.1

M12 Packer #5 Mine borehole 404740076162201 40.7945 -76.2724 972 3.62 5.27

M13 Packer #5 Mine breach 404739076162801 40.7943 -76.2741 965 5 5.8

M17 Preston Mine #3 Tunnel overflow 404725076173401 40.7904 -76.2924 960 0.67 2.23

M18 Bast Mine Tunnel 404729076180801 40.7919 -76.3013 950 0.4 0.67

M19 Centralia Mine tunnel 404727076192601 40.7909 -76.3236 1,090 2.43 3.86

M20 Bast Mine Overflow site 404711076190901 40.7864 -76.3188 910 0 2.23

M21 Bast Mine Oakland Tunnel 404706076195401 40.7851 -76.3313 900 2.3 4

M22 Tunnel Mine seepage to ditch from bank 404655076195301 40.7828 -76.3315 900 0.03 0.03

M23 Tunnel Mine discharge from spoil bank 404650076200201 40.7804 -76.3339 900 0.03 0.03

M24 Tunnel Mine drain pool area and storage 404645076201201 40.7791 -76.3365 930 0.09 0.13
52 Water budgets and groundwater volumes for abandoned mines in the Western Middle Anthracite Coalfield, Pa

Table 3. Site descriptions and flow rates of abandoned mine discharges in the Western Middle Anthracite Coalfield, Schuylkill, 

Columbia, and Northumberland Counties, Pennsylvania, 1999–2001.—Continued

[USGS, U.S. Geological Survey; ft, feet above National Geodetic Vertical Datum of 1929; ft3/s, cubic feet per second; colored shading identifies sites with 

maximum discharge greater than 1 ft3/s and are considered in numerical flow model: yellow, Shamokin Creek; green, Mahanoy Creek; red, Schuylkill River]

Local 

identification 

number

Local name USGS station 

number Latitude Longitude Altitude (ft)

Discharge1

Minimum 

(ft3/s)

Maximum 

(ft3/s)

Mahanoy Creek Basin

M25 Tunnel Mine Orchard Drift overflow 404648076202301 40.7800 -76.3398 900 0.04 0.04

M26 Potts Mine West breach 404634076221901 40.7762 -76.3716 979 0.36 1.44

M27 Potts Mine East breach 404624076221501 40.7734 -76.3705 990 0.22 0.29

M28 Lavelle Mine Lavelle slope 404558076240501 40.7661 -76.4014 1,180 0.01 0.23

M29 Locust Gap Mine Helfenstein Tunnel 404504076261201 40.7512 -76.4363 710 7.29 17.2

M30 Locust Gap Mine Helfenstein seepage 404515076265201 40.7542 -76.4478 1,130 0 0.09

M31 Locust Gap Mine Doutyville tunnel 404435076283801 40.7431 -76.4769 730 0.99 3.52

M32 N. Franklin Mine drift and borehole 404617076404401 40.7715 -76.6786 875 2.56 6.45

M33 N. Franklin Mine seepage 404636076405801 40.7768 -76.6825 840 0 0.03

M34 N. Franklin Mine bank seepage 404617076405201 40.7715 -76.6808 880 0 0.02

Schuylkill River Basin

MC01 Morea Mine Strip Pool Overflow 404657079105501 40.7825 -76.1819 1,400 1.4 15

1

 Abandoned mine discharge (AMD) sites in the study area were described in previous reports by the U.S. Geological Survey (Growitz and others, 1985; 

Reed and others, 1987; Wood, 1996; Cravotta and Kirby, 2004; Cravotta, 2005). Minimum and maximum discharge values for sites in the Shamokin and 

Mahanoy Creek Basins are based on two measurements during 1999–2001 (Cravotta and Kirby, 2004; Cravotta, 2005) and for the site in the Schuylkill River 

Basin on two measurements in 1979 and 1990 (Wood, 1996).

2

 During August 2000 and March 2001, when other AMD and stream sites in the Mahanoy Creek Basin were sampled by the U.S. Geological Survey, the 

Gilberton Mine Pump was not operating and the discharge was dry (Cravotta, 2005). Reed and others (1987, p. 13) indicated that the Gilberton Mine Pump 

operates 40 percent of the time, and thus estimated the flow as 40 percent of the measured value of 23 ft3/s. The value of 10.83 ft3/s indicated for “maximum 

flow rate” during the 1999–2001 study period corresponds to a discharge rate of 7 million gallons per day, which approximates the long-term annual average 

on the basis of pumping records for 1985–1998 (Susquehanna River Basin Commission, 2005). In 1979 and 1990, the USGS measured discharges of 23 and 

7.8 ft3/s, respectively, for the Gilberton pump (Wood, 1995).

3

 During 2000–2001, the Hammond Mine Connerton Village boreholes could not be accessed (Cravotta, 2005). On the basis of Reed and others (1987), 

values above were estimated as 8.5 times the flow measured for the Hammond Mine seepage.
Table 5. Locations of boreholes and altitudes of groundwater 53

Table 5. Locations of boreholes and altitudes of groundwater used to estimate volume of water stored in underground mines and to adjust the groundwater-flow model of the Western Middle Anthracite Coalfield, Schuylkill, Northumberland, and Columbia Counties, Pennsylvania.—Continued[USGS, U.S. Geological Survey; PaDEP, Pennsylvania Department of Environmental Protection; ft, feet above National Geodetic Vertical Datum of 1929; n.d., no data]

Local identification number1

Mine pool name Latitude Longitude Name of lowest coalbed2 Borehole altitude (ft) Groundwater altitude (ft) USGS PaDEP Bottom Surface Average Minimum Maximum

SC 319 1B Mahanoy City 40.8165 -76.1409 Skidmore (V) 1,075 1,232 1,132 1,107 1,166SC 317 2 Maple Hill 40.8101 -76.1790 Orchard 1,062 1,205 1,133 1,107 1,167SC 300 3 Vulcan-Buck Mtn 40.8156 -76.1263 Mammoth (V) 1,106 1,259 1,252 1,248 1,259SC 299 4A Tunnel Ridge 40.8105 -76.1534 Mammoth (V) 999 1,199 1,151 1,120 1,178SC 302 5 St. Nicholas 40.8047 -76.1785 Little Buck Mtn. (V) 879 1,161 1,132 1,105 1,156SC 318 6 Weston 40.8081 -76.2466 Diamond (V) 731 1,023 1,021 1,018 1,023SC 315 7 Kohinoor 40.8217 -76.2104 Mammoth (V) 1,093 1,243 1,123 1,097 1,149SC 316 8 Gilberton 40.8007 -76.2088 Mammoth (V) 863 1,148 1,100 1,095 1,119SC 305 9A West Bear Ridge 40.7937 -76.2529 Mammoth (V) 898 1,138 1,068 1,044 1,092SC 313 10 Packer No. 5 40.7945 -76.2741 Four-Foot (V) 724 972 956 952 960SC 303 11A Indian Ridge 40.8235 -76.1979 Mammoth (V) 928 1,283 1,120 1,093 1,145

NU 147 12A Burnside 40.7662 -76.5572 Primrose 676 976 800 779 846NU 153 13B Buck Ridge No. 1 40.7878 -76.5181 Little Orchard 550 939 820 810 831NU 155 15 Scott 40.7917 -76.4835 Top Split Mammoth (V) 938 1,061 1,000 993 1,015

NU 111 16 Reliance 40.7916 -76.4260 Holmes (V) 856 1,063 998 984 1,024

NU 127 17 Sayre-Sioux 40.7974 -76.4029 Mammoth (V) 871 1,089 1,008 995 1,038

SC 314 18B Park Nos. 1 & 2 40.8266 -76.1385 Seven-Foot (V) n.d. 1,333 1,257 1,237 1,276SC 297 21 Knickerbocker 40.8304 -76.1489 Buck Mtn. (V) 1,028 1,479 1,135 1,110 1,174SC 308 24 Locust Run-Germantown 40.7924 -76.3227 Mammoth 836 986 976 973 979SC 320 25 Bast 40.7870 -76.3159 Diamond 633 913 908 906 911SC 309 26A Tunnel 40.7838 -76.3311 Little Tracy 622 897 886 884 888

27 Centralia 40.8047 -76.3361 n.d. n.d. 1,451 1,017 1,012 1,025

CO 65 28 Potts 40.7776 -76.3790 Little Diamnond 655 1,044 1,002 978 1,025

NU 142 30A Richards Shaft 40.8086 -76.4441 Buck Mtn. 825 1,287 1,175 1,108 1,225NU 128 31 Greenough 40.8063 -76.4646 Whites 944 1,395 1,090 1,073 1,141

E31 Luke Fiddler 40.7955 -76.5293 n.d. n.d. 945 736 718 769

NU 137 32 Scott 40.7957 -76.4670 Bot Split Mammoth 814 1,143 999 993 1,015NU 150 33 Alaska 40.7800 -76.4468 Four-Foot (V) 853 1,077 1,004 992 1,030NU 130 34 Locust Gap 40.7711 -76.4416 Skidmore (V) 686 1,198 892 884 900NU 122 35 Colbert 40.7947 -76.5207 Buck Mtn 687 917 735 716 774
54 Water budgets and groundwater volumes for abandoned mines in the Western Middle Anthracite Coalfield, Pa Table 5. Locations of boreholes and altitudes of groundwater used to estimate volume of water stored in underground mines and to adjust the groundwater-flow model of the Western Middle Anthracite Coalfield, Schuylkill, Northumberland, and Columbia Counties, Pennsylvania.—Continued [USGS, U.S. Geological Survey; PaDEP, Pennsylvania Department of Environmental Protection; ft, feet above National Geodetic Vertical Datum of 1929; n.d., no data] Local identification number1 Mine pool name Latitude Longitude Name of lowest coalbed2 Borehole altitude (ft) Groundwater altitude (ft) USGS PaDEP Bottom Surface Average Minimum Maximum NU 149 36 Enterprise 40.7715 -76.4868 Skidmore 871 1,060 963 959 1,010 NU 154 37A Maysville 40.7857 -76.5132 Orchard 502 873 852 849 857 NU 148 38 Luke Fiddler 40.7906 -76.5386 Primrose 354 804 751 739 758 NU 144 40 Henry Clay-Stirling 40.7770 -76.5688 Little Orchard 500 780 780 779 780 NU 146 42 Bear Valley 40.7675 -76.5869 Rough 610 946 785 757 800 NU 129 43 North Franklin 40.7708 -76.6771 Bot Split Mammoth (V) 530 877 873 870 877 SC 304 46 Lawrence 40.7980 -76.2249 Four-Foot (V) 958 1,154 1,100 1,092 1,117 SC 307 47A Hammond 40.8054 -76.2641 Skidmore Leader (V) 858 1,060 1,009 1,001 1,040 NU 134 48 Richards Water Level 40.8124 -76.4518 Whites 980 1,435 1,198 1,172 1,213 NU 135 49 Natalie 40.8166 -76.4605 Lykens Valley (V) 970 1,503 1,098 1,084 1,142 NU 131 50 Hickory Ridge 40.8040 -76.4961 Buck Mtn 779 1,139 1,054 1,044 1,061 NU 151 52 Royal Oak 40.7891 -76.5400 Orchard 449 774 764 747 771 NU 145 53 Neilson 40.7845 -76.5588 Orchard 562 739 729 713 732 NU 136 55 Excelsior 40.7739 -76.4988 Top Split Mammoth n.d. 982 948 940 969 SC 312 57 William Penn 40.8076 -76.2371 Primrose (V) 754 1,049 1,032 1,012 1,049 SC 331 58A Lawrence 40.7928 -76.2437 n.d. n.d. 1,112 1,095 1,088 1,112 NU 132 PShaft Pennsylvania 40.8025 -76.4483 Little Buck Mtn. (V) 615 1,144 999 992 1,008 NU 133 RShaft Richards Shaft 40.8059 -76.4377 Little Buck Mtn. (V) 315 1,164 1,081 1,075 1,088

1 USGS identification numbers used by Reed and others (1987). PaDEP identification numbers used by Pennsylvania Department of Environmental Protection, Bureau of Abandoned Mine Reclamation.2 Description of borehole reported by Reed and others (1987). “V” indicates that mine void was encountered at bottom of borehole.
For additional information, write to:

Director

U.S. Geological Survey

Pennsylvania Water Science Center

215 Limekiln Rd.

New Cumberland, PA 17070

or visit our Web site at:

http://pa.water.usgs.gov/

Document prepared by the West Trenton Publishing Service Centers
Goode and others—Water budgets and groundwater volumes for abandoned mines in the Western Middle Anthracite Coalfield, Pa—Scientific Investigations Report 2010–5261

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