Open-File Report 2006–1168

U.S. Department of the Interior

U.S. Geological Survey

Prepared in cooperation with the North Carolina Department of Environment and Natural

Resources, Division of Water Quality

Compilation of Water-Resources Data and

Hydrogeologic Setting for Four Research Stations

in the Piedmont and Blue Ridge Physiographic

Provinces of North Carolina, 2000–2004
Cover. 

1

2

3

1– North Carolina Department of Environment and Natural Resources, Division of Water Quality,

drillers installinga monitoring well (photograph by Donald J. Geddes, Jr., USGS)

2– Well cluster MW–S1 at the Upper Piedmont research station (photograph by Donald J. Geddes, 

Jr., USGS)

3– Data-collection platform at well cluster MW–2 at the Bent Creek research station (photograph 

by Brad A. Huffman, USGS)
Compilation of Water-Resources Data and 

Hydrogeologic Setting for Four Research 

Stations in the Piedmont and Blue Ridge 

Physiographic Provinces of North Carolina, 

2000–2004

By Brad A. Huffman, Cassandra A. Pfeifle, Melinda J. Chapman, Richard E. 

Bolich, Ted R. Campbell, Donald J. Geddes, Jr., and Charles G. Pippin

Prepared in cooperation with the North Carolina Department of Environment and 

Natural Resources, Division of Water Quality

Open-File Report 2006–1168

U.S. Department of the Interior

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

Dirk A. Kempthorne, Secretary

U.S. Geological Survey

P. Patrick Leahy, Acting Director

U.S. Geological Survey, Reston, Virginia: 2006

For product and ordering information:

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Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the 

U.S. Government.

Although this report is in the public domain, permission must be secured from the individual copyright owners to 

reproduce any copyrighted materials contained within this report.

Suggested citation:

Huffman, B.A., Pfeifle, C.A., Chapman, M.J., Bolich, R.E., Campbell, T.R., Geddes, D.J., Jr., and Pippin, C.G., 2006, 

Compilation of water-resources data and hydrogeologic setting for four research stations in the Piedmont and Blue 

Ridge Physiographic Provinces of North Carolina, 2000–2004: U.S. Geological Survey Open-File Report 2006–1168, 

102 p., available online at http://pubs.water.usgs.gov/ofr2006–1168
iii

Contents

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

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

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

Description of the Study Areas .........................................................................................................3

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

Methods of Data Collection ........................................................................................................................3

Well Construction ................................................................................................................................3

Well and Surface-Water Station Numbering System ....................................................................5

Borehole Geophysical Logging .........................................................................................................5

Continuous Monitoring .......................................................................................................................5

Periodic Water-Level Measurements ..............................................................................................6

Slug Tests ..............................................................................................................................................6

Water-Quality Sampling and Laboratory Analysis .........................................................................6

Statistical Analysis of Water-Quality Data ......................................................................................7

Lake Wheeler Road Research Station ......................................................................................................7

Site Description and Geology ............................................................................................................7

Well Construction ................................................................................................................................7

Water-Resources Data .....................................................................................................................11

Langtree Peninsula Research Station .....................................................................................................31

Site Description and Geology ..........................................................................................................31

Well Construction ..............................................................................................................................31

Water-Resources Data .....................................................................................................................37

Upper Piedmont Research Station ..........................................................................................................54

Site Description and Geology ..........................................................................................................54

Well Construction ..............................................................................................................................54

Water-Resources Data .....................................................................................................................61

Bent Creek Research Station ....................................................................................................................83

Site Description and Geology ..........................................................................................................83

Well Construction ..............................................................................................................................83

Water-Resources Data .....................................................................................................................83

Summary .....................................................................................................................................................101

References .................................................................................................................................................101

Figures

1. Map showing research stations selected for investigations as part of the cooperative 

U.S. Geological Survey-North Carolina Division of Water Quality PiedmontMountains Ground-Water Study in North Carolina ...............................................................2

2. Maps showing locations of Lake Wheeler Road research station, hydrogeologic 

units in Wake County, and geologic belts delineated in the Piedmont Physiographic 

Province of North Carolina .........................................................................................................4
iv

3. Aerial photograph overlaid with topographic features showing locations of well 

clusters, streamgaging station, climate station, and lines of section at the Lake 

Wheeler Road research station in Wake County, North Carolina .......................................8

4. Generalized hydrogeologic cross sections A–A’ and B–B’ along the well transects 

at the Lake Wheeler Road research station, North Carolina .............................................10

5. Geophysical logs of bedrock well MW–1D at the Lake Wheeler Road research 

station, North Carolina ..............................................................................................................12

6. Geophysical logs of transition-zone fractures (MW–1DUZ) in well MW–1D at the 

Lake Wheeler Road research station, North Carolina ........................................................13

7. Geophysical logs of transition-zone well MW–2T at the Lake Wheeler Road 

research station, North Carolina .............................................................................................14

8. Geophysical logs of bedrock well MW–2D at the Lake Wheeler Road research 

station, North Carolina ..............................................................................................................15

9. Geophysical logs of bedrock well MW–3D at the Lake Wheeler Road research 

station, North Carolina ..............................................................................................................16

10. Geophysical logs of bedrock well PW–1 at the Lake Wheeler Road research 

station, North Carolina ..............................................................................................................17

11. Graphs showing periodic ground-water levels recorded in well clusters (A) MW–1, 

(B) MW–2, (C) MW–3, and (D) the aquifer-test well and piezometers at the Lake 

Wheeler Road research station, North Carolina ..................................................................18

12. Graph showing hourly ground-water levels recorded in well cluster MW–1 and 

hourly stage recorded at the tributary site at the Lake Wheeler Road research 

station, North Carolina ..............................................................................................................19

13. Graph showing hourly ground-water levels recorded in bedrock wells MW–2D 

and MW–3D at the Lake Wheeler Road research station, North Carolina ......................20

14. Piper diagrams showing the water chemistry of samples from (A) regolith and 

transition-zone wells and the tributary site, and (B) bedrock wells at the Lake 

Wheeler Road research station, North Carolina ..................................................................21

15. Stiff diagrams showing major ion milliequivalents in water samples collected from 

(A) regolith wells and the tributary site, (B) transition-zone wells, and (C) openborehole bedrock wells at the Lake Wheeler Road research station, 

North Carolina, May 2002 .........................................................................................................22

16. Box plots showing the range, median, and quartile statistical values for (A) pH, 

(B) specific conductance, and (C) dissolved oxygen for wells and the tributary 

site during periodic sampling events at the Lake Wheeler Road research station, 

North Carolina ............................................................................................................................23

17. Box plots showing the range, median, and quartile statistical values for (A) calcium, 

(B) magnesium, and (C) sodium for wells and the tributary site during periodic 

sampling events at the Lake Wheeler Road research station, North Carolina ...............24

18. Box plots showing the range, median, and quartile statistical values for (A) bicarbonate, (B) chloride, and (C) sulfate for wells and the tributary site during periodic 

sampling events at the Lake Wheeler Road research station, North Carolina ...............25

19. Graphs showing hourly record of (A) temperature, (B) pH, (C) specific conductance, 

and (D) dissolved oxygen in well MW–1S in the shallow regolith at the Lake Wheeler 

Road research station, North Carolina, December 2002 through June 2004 ...................26

20. Graphs showing hourly record of (A) temperature, (B) pH, (C) specific conductance, 

and (D) dissolved oxygen in well MW–1I in the transition zone at the Lake Wheeler 

Road research station, North Carolina, December 2002 through June 2004 ...................27
v

21. Graphs showing hourly record of (A) temperature, (B) pH, (C) specific conductance, 

and (D) dissolved oxygen in well MW–1D in the bedrock at the Lake Wheeler Road 

research station, North Carolina, December 2002 through June 2004 .............................28

22. Graphs showing hourly record of (A) temperature, (B) pH, (C) specific conductance, 

and (D) dissolved oxygen in well MW–1DUZ during installation of an inflatable 

packer at the Lake Wheeler Road research station, North Carolina, July 2002 

through November 2003 ............................................................................................................29

23. Graphs showing 15-minute record of (A) temperature, (B) pH, (C) specific conductance, and (D) dissolved oxygen in the unnamed tributary at the Lake Wheeler Road 

research station, North Carolina, April 2002 through June 2004 .......................................30

24. Maps showing locations of Langtree Peninsula research station, hydrogeologic 

units in Iredell County, and geologic belts delineated in North Carolina .........................32

25. Aerial photograph and topographic map showing locations of well clusters, lake 

site, and lines of section at the Langtree Peninsula research station in Iredell 

County, North Carolina ..............................................................................................................33

26. Generalized hydrogeologic cross section A–A’ along the well transect at 

the Langtree Peninsula research station, North Carolina ..................................................34

27. Generalized hydrogeologic cross section B–B’ along the well transect at 

the Langtree Peninsula research station, North Carolina ..................................................35

28. Geophysical logs of bedrock well MW–1D at the Langtree Peninsula research 

station, North Carolina ..............................................................................................................38

29. Geophysical logs of bedrock well MW–2D at the Langtree Peninsula research 

station, North Carolina ..............................................................................................................39

30. Geophysical logs of bedrock well MW–4D at the Langtree Peninsula research 

station, North Carolina ..............................................................................................................40

31. Geophysical logs of bedrock well MW–5D at the Langtree Peninsula research 

station, North Carolina ..............................................................................................................41

32. Geophysical logs of bedrock well MW–6D at the Langtree Peninsula research 

station, North Carolina ..............................................................................................................42

33. Graphs showing periodic ground-water levels recorded in well clusters (A) MW–1, 

(B) MW–2, (C) MW–3, (D) MW–4, (E) MW–5, and (F) MW–6 at the Langtree 

Peninsula research station, North Carolina ..........................................................................43

34. Graph showing periodic ground-water levels recorded in piezometers at the 

Langtree Peninsula research station, North Carolina .........................................................44

35. Graph showing continuous hourly ground-water levels recorded in well cluster 

MW–2 at the Langtree Peninsula research station, North Carolina .................................45

36. Maps showing water-level altitudes measured in the shallow regolith at the 

Langtree Peninsula research station, North Carolina, for (A) September 23, 2003 

(maximum), and (B) October 18, 2002 (minimum) ..................................................................46

37. Piper diagrams showing the water chemistry of samples from (A) regolith and 

transition-zone wells and the lake site, and (B) open-borehole bedrock wells at 

the Langtree Peninsula research station, North Carolina ..................................................47

38. Stiff diagrams showing major ion milliequivalents in water samples collected 

from (A) regolith wells and the lake site, (B) transition-zone wells, and 

(C) open-borehole bedrock wells at the Langtree Peninsula research station, 

North Carolina, March 2003 .....................................................................................................48

39. Box plots showing the range, median, and quartile statistical values for (A) pH, 

(B) specific conductance, and (C) dissolved oxygen for wells and the lake site 

during periodic sampling events at the Langtree Peninsula research station, 

North Carolina ............................................................................................................................49
vi

40. Box plots showing the range, median, and quartile statistical values for (A) calcium, 

(B) magnesium, and (C) sodium for wells and the lake site during periodic sampling 

events at the Langtree Peninsula research station, North Carolina .................................50

41. Box plots showing the range, median, and quartile statistical values for 

(A) bicarbonate, (B) chloride, and (C) sulfate for wells and the lake site during 

periodic sampling events at the Langtree Peninsula research station, 

North Carolina ............................................................................................................................51

42. Graphs showing hourly record of (A) temperature, (B) pH, (C) specific conductance, 

and (D) dissolved oxygen in well MW–2S in the shallow regolith at the Langtree 

Peninsula research station, North Carolina ..........................................................................52

43. Graphs showing hourly record of (A) temperature, (B) pH, (C) specific conductance, 

and (D) dissolved oxygen in well MW–2D in bedrock at the Langtree Peninsula 

research station, North Carolina .............................................................................................53

44. Maps showing locations of Upper Piedmont research station, hydrogeologic units 

in Rockingham County, and geologic belts delineated in North Carolina ........................55

45. Aerial photograph overlaid with topographic features showing locations of well 

clusters, surface-water site, and line of section A–A’ along the northern 

transect at the Upper Piedmont research station in Rockingham County, 

North Carolina ............................................................................................................................56

46. Aerial photograph overlaid with topographic features showing locations of well 

clusters, streamgaging station, and line of section B–B’ along the southern 

transect at the Upper Piedmont research station in Rockingham County, 

North Carolina ............................................................................................................................57

47. Generalized hydrogeologic cross section A–A’ along the northern well transect 

at the Upper Piedmont research station, North Carolina ...................................................58

48. Generalized hydrogeologic cross section B–B’ along the southern well transect 

at the Upper Piedmont research station, North Carolina ...................................................59

49. Geophysical logs of bedrock well MW–N1D at the Upper Piedmont research 

station, North Carolina ..............................................................................................................62

50. Geophysical logs of bedrock well MW–N2D at the Upper Piedmont research 

station, North Carolina ..............................................................................................................63

51. Geophysical logs of bedrock well MW–N3D at the Upper Piedmont research 

station, North Carolina ..............................................................................................................64

52. Geophysical logs of bedrock well MW–N4D at the Upper Piedmont research 

station, North Carolina ..............................................................................................................65

53. Geophysical logs of bedrock well MW–S1D at the Upper Piedmont research 

station, North Carolina ..............................................................................................................66

54. Geophysical logs of bedrock well MW–S3D at the Upper Piedmont research 

station, North Carolina ..............................................................................................................67

55. Geophysical logs of bedrock well MW–S4D at the Upper Piedmont research 

station, North Carolina ..............................................................................................................68

56. Graphs showing periodic ground-water levels recorded in well clusters (A) MW–N1, 

(B) MW–N2, (C) MW–N3, and (D) MW–N4 along the northern transect at the Upper 

Piedmont research station, North Carolina ...........................................................................69

57. Graphs showing periodic ground-water levels recorded in well clusters (A) MW–S1, 

(B) MW–S3, and (C) MW–S4 along the southern transect at the Upper Piedmont 

research station, North Carolina .............................................................................................70

58. Graph showing periodic ground-water levels recorded in piezometers at the 

Upper Piedmont research station, North Carolina ...............................................................71
vii

59. Graph showing hourly ground-water levels recorded in well cluster MW–S4 and 

continuous stage at the streamgaging station at the Upper Piedmont research 

station, North Carolina, May 2003 through October 2004 ...................................................72

60. Graph showing hourly ground-water levels recorded in bedrock well MW–S3D 

at the Upper Piedmont research station, North Carolina, November 2003 

through March 2004 ..................................................................................................................73

61. Piper diagrams showing the water chemistry of samples from (A) regolith and 

transition-zone wells, and surface-water sites, and (B) transition-zone and 

open-borehole bedrock wells at the Upper Piedmont research station, 

North Carolina ............................................................................................................................74

62. Stiff diagrams showing major ion milliequivalents in water samples collected 

from (A) regolith wells and the surface-water sites (B) transition-zone wells, and 

(C) open-borehole bedrock wells at the Upper Piedmont research station, 

North Carolina, December 2002 ..............................................................................................75

63. Box plots showing the range, median, and quartile statistical values for (A) pH, 

(B) specific conductance, and (C) dissolved oxygen for wells and surfacewater sites during periodic sampling events at the Upper Piedmont research 

station, North Carolina ............................................................................................................76

64. Box plots showing the range, median, and quartile statistical values for (A) calcium, 

(B) magnesium, and (C) sodium for wells and surface-water sites during periodic 

sampling events at the Upper Piedmont research station, North Carolina .....................77

65. Box plots showing the range, median, and quartile statistical values for (A) bicarbonate, (B) chloride, and (C) sulfate for wells and surface-water sites during periodic 

sampling events at the Upper Piedmont research station, North Carolina .....................78

66. Graphs showing hourly record of (A) temperature, (B) pH, (C) specific conductance, 

and (D) dissolved oxygen in well MW–S4S in the shallow regolith at the Upper 

Piedmont research station, North Carolina ...........................................................................79

67. Graphs showing hourly record of (A) temperature, (B) pH, (C) specific conductance, 

and (D) dissolved oxygen in well MW–S4I in the transition zone at the Upper 

Piedmont research station, North Carolina ...........................................................................80

68. Graphs showing hourly record of (A) temperature, (B) pH, (C) specific conductance, 

and (D) dissolved oxygen in well MW–S4D in the bedrock at the Upper Piedmont 

research station, North Carolina .............................................................................................81

69. Graphs showing 15-minute record of (A) temperature, (B) pH, (C) specific conductance, and (D) dissolved oxygen in Wolf Island Creek at the Upper Piedmont 

research station, North Carolina .............................................................................................82

70. Maps showing locations of Bent Creek research station, hydrogeologic units in 

Buncombe County, and geologic belts delineated in North Carolina ...............................84

71. Aerial photograph overlaid with topographic features showing locations of well 

clusters, surface-water sites, and line of section A–A’ at the Bent Creek research 

station in Buncombe County, North Carolina ........................................................................85

72. Generalized hydrogeologic cross section A–A’ along the well transect at 

the Bent Creek research station, North Carolina .................................................................87

73. Geophysical logs of bedrock well MW–1D at the Bent Creek research station, 

North Carolina ............................................................................................................................88

74. Geophysical logs of bedrock well MW–2D at the Bent Creek research station, 

North Carolina ............................................................................................................................89

75. Geophysical logs of bedrock well MW–3D at the Bent Creek research station, 

North Carolina ............................................................................................................................90
viii

76. Geophysical logs of bedrock well MW–4D at the Bent Creek research station, 

North Carolina ............................................................................................................................91

77. Geophysical logs of bedrock well MW–5D at the Bent Creek research station, 

North Carolina ............................................................................................................................92

78. Geophysical logs of bedrock well MW–7D at the Bent Creek research station, 

North Carolina ............................................................................................................................93

79. Graphs showing periodic ground-water levels recorded in well clusters (A) MW–1, 

(B) MW–2, (C) MW–3, (D) MW–4, (E) MW–5, and (F) MW–7 at the Bent Creek 

research station, North Carolina .............................................................................................94

80. Piper diagrams showing the water chemistry of samples from (A) regolith and 

transition-zone wells and surface-water sites, and (B) open-borehole bedrock 

wells at the Bent Creek research station, North Carolina ..................................................96

81. Stiff diagrams showing major ion milliequivalents in water samples collected from 

(A) regolith wells and surface-water sites, (B) transition-zone wells, and (C) openborehole bedrock wells at the Bent Creek research station, North Carolina, 

April 2003 .....................................................................................................................................97

82. Box plots showing the range, median, and quartile statistical values for (A) pH, 

(B) specific conductance, and (C) dissolved oxygen for wells and surface-water 

sites during periodic sampling events at the Bent Creek research station, 

North Carolina ............................................................................................................................98

83. Box plots showing the range, median, and quartile statistical values for (A) calcium, 

(B) magnesium, and (C) sodium for wells and surface-water sites during 

periodic sampling events at the Bent Creek research station, North Carolina ..............99

84. Box plots showing the range, median, and quartile statistical values for (A) bicarbonate, (B) chloride, and (C) sulfate for wells and surface-water sites during periodic 

sampling events at the Bent Creek research station, North Carolina ............................100

Tables

1. Construction characteristics of monitoring wells and the surface-water site at 

the Lake Wheeler Road research station, North Carolina ....................................................9

2. Analytical results of slug tests in wells at the Lake Wheeler Road research 

station, North Carolina...............................................................................................................11

3. Construction characteristics of monitoring wells and the surface-water site at 

the Langtree Peninsula research station, North Carolina ..................................................36

4. Analytical results of slug tests in wells at the Langtree Peninsula research 

station, North Carolina...............................................................................................................37

5. Construction characteristics of monitoring wells and the surface-water site at 

the Upper Piedmont research station, North Carolina ........................................................60

6. Analytical results of slug tests in wells at the Upper Piedmont research 

station, North Carolina...............................................................................................................61

7. Construction characteristics of monitoring wells and the surface-water site at 

the Bent Creek research station, North Carolina .................................................................86

8. Analytical results of slug tests in wells at the Bent Creek research 

station, North Carolina ..............................................................................................................95
ix

Conversion Factors, Vertical Datum, Temperature, 

and Definitions 

Multiply By To Obtain

Length

inch (in.) 2.54 centimeter (cm)

foot (ft) 0.3048 meter (m)

mile (mi) 1.609 kilometer (km)

Area

acre 0.4047 hectare (ha)

square mile (mi2

) 2.590 square kilometer (km2)

Volume

gallon (gal) 3.785 liter (L)

Flow

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

Radioactivity

picocurie per liter (pCi/L) 0.037 becquerel per liter (Bq/L)

Pressure

pound per square inch (lb/in2

) 6.895 Kilopascal (kPa)

Vertical coordinates: Vertical coordinates in this report are referenced to the North American 

Vertical Datum of 1988 (NAVD 88).

Horizontal coordinates: Horizontal coordinates (latitude and longitude) in this report are 

referenced to the North American Datum of 1983 (NAD 83).

Temperature: In this report, water temperature is reported in degrees Celsius (°C), which can 

be converted to degrees Fahrenheit (°F) by using the following equation:

°F = (1.8 x °C) + 32

Water-quality measurements: 

 μS/cm microsiemens per centimeter at 25 °C 

 μg/L microgram per liter

 mg/L milligram per liter
x

Acronyms and abbreviations: 

BAT3 Bedrock-Aquifer Transportable Testing Tool

BCRS Bent Creek research station

DCP data-collection platform

DO dissolved oxygen

DWQ Division of Water Quality

GNF felsic gneiss hydrogeologic unit

GNM mafic gneiss hydrogeologic unit

GP geoprobe

GWSI Ground Water Site Inventory

IQR interquartile range

LPRS Langtree Peninsula research station

LWRRS Lake Wheeler Road research station

MII intermediate metaigneous hydrogeologic unit

MP measuring point

MW monitoring well

NCDENR North Carolina Department of Environment and Natural Resources

NCGS North Carolina Geological Survey

NCSU North Carolina State University

NWIS National Water Information System

OTV optical televiewer

PVC polyvinyl chloride

PW pumping well

PZ piezometer

PMREP Piedmont and Mountains Resource Evaluation Program

QTZ quartzite hydrogeologic unit

SC specific conductance

SOP standard operating procedure

SWETC Soil and Water Environmental Technology Center

UPRS Upper Piedmont research station

USGS U.S. Geological Survey

WL water level or augered well
Abstract

Water-resources data were collected to describe the 

hydrologic conditions at four research stations in the Piedmont 

and Blue Ridge Physiographic Provinces of North Carolina. 

Data collected by the U.S. Geological Survey and the North 

Carolina Department of Environment and Natural Resources, 

Division of Water Quality, from September 2000 through 

September 2004 are presented in this report. The locations and 

periods of data collection are as follows: the Lake Wheeler 

Road research station (Raleigh) from April 2001 to September 

2004, the Langtree Peninsula research station (Mooresville) 

from September 2000 to September 2004, the Upper Piedmont 

research station (Reidsville) from March 2002 to September 

2004, and the Bent Creek research station (Asheville) from 

July 2002 to September 2004. 

Data presented in this report include well-construction 

characteristics for 110 wells, periodic ground-water-level 

measurements for 96 wells, borehole geophysical logs for 23 

wells, hourly ground-water-level measurements for 12 wells, 

continuous-stage measurements for 2 streams, continuous 

water-quality measurements for 8 wells and 2 streams, 

periodic water-quality samples for 57 wells and 6 stream sites, 

slug-test results for 38 wells, and shallow ground-water-flow 

maps. In addition, the geology and hydrogeology at each site 

are summarized.

Introduction

In 1999, the U.S. Geological Survey (USGS) and the 

North Carolina Department of Environment and Natural 

Resources (NCDENR), Division of Water Quality (DWQ), 

began a multiyear cooperative study to measure ambient 

ground-water quality and describe the ground-water-flow 

systems at selected research stations in the Piedmont and Blue 

Ridge Physiographic Provinces of North Carolina (Daniel and 

Dahlen, 2002). The study is supported by the Piedmont and 

Mountains Resource Evaluation Program (PMREP), which 

was created by the North Carolina Legislature to ensure the 

long-term availability, sustainability, and quality of ground 

water in the State. The study was designed to be a 10-year, 

intensive field investigation at research stations established in 

representative hydrogeologic settings across the State. To date 

(2006), eight research stations have been selected for study 

in the Piedmont and Blue Ridge Physiographic Provinces 

(fig. 1), and wells have been installed at six of these research 

stations. Data from research stations in Raleigh, Mooresville, 

Reidsville, and Asheville are included in this report. These 

data are providing information to refine the historical 

conceptual ground-water-flow models for the Piedmont and 

Blue Ridge Physiographic Provinces in North Carolina and the 

Southeastern United States. 

One of the primary objectives of the PMREP in installing 

research stations in representative hydrogeologic settings 

is to evaluate the spatial and temporal variation of ambient 

ground-water levels and ground-water-quality data across 

the Piedmont and Blue Ridge Physiographic Provinces. The 

research stations generally consist of transects of monitoringwell clusters located parallel to an assumed flow path within a 

conceptual “slope-aquifer” system, described by LeGrand and 

Nelson (2004), from recharge to discharge areas. Well clusters 

are designed to monitor separate zones in the ground-water 

system, including the shallow regolith, transition zone, and 

deep bedrock (Chapman and others, 2005).

Purpose and Scope

The purpose of this report is to summarize data collected 

from September 2000 through September 2004 at four of 

Compilation of Water-Resources Data and Hydrogeologic 

Setting for Four Research Stations in the Piedmont and 

Blue Ridge Physiographic Provinces of North Carolina, 

2000–2004

By Brad A. Huffman1, Cassandra A. Pfeifle1, Melinda J. Chapman1, Richard E. Bolich2, Ted R. Campbell2, 

Donald J. Geddes, Jr. 2, and Charles G. Pippin2

1

U.S. Geological Survey, North Carolina Water Science Center.

2

North Carolina Department of Environment and Natural Resources, 

Division of Water Quality, Aquifer Protection Section.
Figure 1. Research stations selected for investigations as part of the cooperative U.S. Geological Survey-North Carolina Division of Water Quality Piedmont-Mountains GroundWater Study in North Carolina.

MACON

BUNCOMBE

IREDELL

ROCKINGHAM

WAKE 

Raleigh

Region

Mooresville

Region

2

6

Fall

Line 1

7

Asheville

Region

Winston-Salem

Region

4

5 8

3

4

VIRGINIA

SOUTH CAROLINA 

GEORGIA

TENNESSEE

Blue Ridge

Coastal Plain

84 

36 35 34 

83 82 81 80 79 78 77 76 

0 20 40 60 80 100 MILES 0 20 40 60 80 100 KILOMETERS 

Langtree Peninsula at Lake Norman (LPRS)North Carolina State University Lake Wheeler Road Field Laboratory (LWRRS)North Carolina State University Upper Piedmont Research Station (UPRS)Bent Creek Experimental Forest (BCRS)City of Highlands; Cullasaja WatershedRaleigh Hydrogeologic Research StationAllison Woods Hydrogeologic Research StationCoweeta Hydrogeologic Research Station

North Carolina Department of Environment and Natural Resources regional officesResearch station and numberWells completedWells not completed at the time of report preparation

12345678

Map number Research station

EXPLANATION

Figure 1. Research stations selected for investigations as part of the cooperative U.S. Geological Survey-North Carolina Division of Water Quality Piedmont-MountainsGround-Water Study in North Carolina.

Atlantic

Ocean

Piedmont

Base from digital files of:U.S. Department of Commerce, Bureau of Census, 1990 Precensus TIGER/Line Files-Political boundaries, 1991U.S. Environmental Protection Agency, River File 3U.S. Geological Survey, 1:100,000 scale 

   Water-Resources Data and Hydrogeologic Setting for Research Stations in the Piedmont and Blue Ridge, 2000–2004
the PMREP research stations. Data are presented for (1) 

Lake Wheeler Road research station in Raleigh (LWRRS), 

(2) Langtree Peninsula research station in Mooresville 

(LPRS), (3) Upper Piedmont research station in Reidsville 

(UPRS), and (4) Bent Creek research station in Asheville 

(BCRS). Descriptions of the regional surficial geology, 

research station design, well characteristics, borehole 

geophysical data, and ground-water-level data are included in 

separate sections of this report for each research station. 

Description of the Study Areas

The Piedmont and Blue Ridge Physiographic Provinces 

in North Carolina encompass about 30,544 square miles (mi2) 

in 65 counties. In 2000, the population of this area was about 

6.11 million, and the total ground-water use was estimated to 

be about 244 million gallons per day (U.S. Geological Survey, 

2005a). Ground water is the primary source of drinking 

water in most rural and some suburban areas of the State, 

whereas surface water is the primary drinking-water source 

in the metropolitan areas (Daniel and Dahlen, 2002). Most 

of the population lives in or near the metropolitan areas of 

Raleigh/Durham/Chapel Hill, Greensboro/Winston-Salem, 

and Charlotte, all of which are located in the Piedmont 

Physiographic Province (Chapman and others, 2005).

The geology of most of the Piedmont and Blue Ridge 

Provinces is complex. Rocks have undergone several 

episodes of intense metamorphism, folding, faulting, 

and igneous intrusion. In North Carolina, the regional 

sequences of rocks are grouped into belts (North Carolina 

Geological Survey, 1985; fig. 2). Although the rocks in 

these belts generally are similar with respect to lithology, 

more variation and complexity can be observed on a local 

scale. Daniel and Dahlen (2002) provided an overview of the 

major hydrogeologic units of the Piedmont and Blue Ridge 

Provinces in reference to the geologic belts of the State. 

The four research stations discussed in this report are in the 

Raleigh litho-tectonic belt (LWRRS), the Charlotte lithotectonic belt (LPRS), the Milton litho-tectonic belt (UPRS), 

and the Blue Ridge litho-tectonic belt (BCRS; fig. 2).

The humid, subtropical climate in the study areas is 

typical for the Southeastern United States. The average annual 

precipitation is 40 to 50 inches, which is distributed fairly 

evenly throughout the year. Hydrologic conditions in water 

years3

 2000–2002 were affected by drought conditions, water 

year 2003 was considered above normal, and water year 2004 

was considered normal (Weaver, 2005). 

Acknowledgments

The authors thank members of the North Carolina 

Department of Environment and Natural Resources and 

the USGS Resource Evaluation Program who continue to 

contribute to data collection and analysis for this project. 

PMREP members include Landon Davidson of the Asheville 

Regional Office, Aquifer Protection Section, and M. Carl 

Bailey and Walter T. Haven of the Raleigh DWQ Central 

Office Planning Branch. In addition, the authors thank the 

DWQ drillers for their support of data collection in the field, 

and the following individuals for their support of this project 

and assistance in facilitating field-site access: Sterling Martin, 

Manager of the Davidson College Lake Campus; Henry 

McNab, U.S. Forest Service, Bent Creek Experimental Forest; 

Ken Snyder, Manager of the North Carolina State University 

Lake Wheeler Road Field Laboratory; Joe French, Ph.D., 

Superintendent of the Upper Piedmont Research Station; and 

Jeff North, Director of the Betsy-Jeff Penn 4–H Educational 

Center. 

Methods of Data Collection

Activities described in this report support the 

investigative work of the overall regional PMREP. Datacollection methods used at each research station are 

summarized here and in the standard operating procedures 

(SOP) for the PMREP (North Carolina Department of 

Environment and Natural Resources, 2002).

Well Construction

The research stations generally consist of a topographic 

transect of monitoring-well clusters. Each transect includes 

well clusters located within a conceptual “slope-aquifer” 

system, described by LeGrand and Nelson (2004), from 

recharge (higher elevations, such as hilltops) to discharge areas 

(lower elevations, such as stream valleys). Well clusters are 

designed to monitor three separate zones in the ground-water 

system—the regolith, the transition zone between regolith and 

bedrock, and the deeper bedrock. The regolith zone includes 

soil residuum, alluvium, colluvium, and saprolite. The 

transition zone consists of partially weathered rock and open 

fractures near the top of bedrock. At some stations, shallow 

regolith wells were not installed because of greater depth to 

the water table. Piezometers were installed at some research 

stations to better describe horizontal and vertical ground-water 

flow and to conduct aquifer tests. To date (2006), 160 wells 

and piezometers have been installed at six research stations 

(fig. 1). Data from four research stations (110 wells and 

piezometers) are summarized in this report.

Well-construction methods are described in Chapman and 

others (2005). Well-construction data are given in tables and in 

the specific site-description sections of this report.

3

Water year is the period from October 1 through September 30 and is 

identified by the year in which the period ends. The 2004 water year, for 

example, was the period October 1, 2003, through September 30, 2004.

Methods of Data Collection 
Figure 2. Locations of Lake Wheeler Road research station, hydrogeologic units in Wake County, and geologic belts delineated in the 

Piedmont Physiographic Province of North Carolina (modified from North Carolina Geological Survey, 1985; Daniel and Payne, 1990).

Base from digital files of:

U.S. Department of Commerce, Bureau of Census,

 1990 Precensus TIGER/Line Files-Political boundaries, 1991

U.S. Environmental Protection Agency, River File 3

U.S. Geological Survey, 1:100,000 scale 

Lake Wheeler Road research station

HYDROGEOLOGIC UNITS

 (Daniel and Payne, 1990)

Coastal plain sediments (CPL)

Gneiss, felsic (GNF)

Gneiss, mafic (GNM)

Igneous, mafic intrusive (IMI)

Metaigneous, felsic (MIF)

Metaigneous, mafic (MIM)

Metavolcanic, felsic (MVF)

Triassic sedimentary rocks (TRI)

0 5 10 MILES

0 8 16 KILOMETERS

N

Falls

Lake

Neuse

River

Swift

Creek

Raleigh

Figure 2. Locations of Lake Wheeler Road research station, hydrogeologic units in Wake County, and geologic belts delineated 

in the Piedmont Physiographic Province of North Carolina (modified from North Carolina Geological Survey, 1985

and Daniel and Payne,1990.

Murphy Belt

Blue

Ridge

Belt

Chauga

Belt

Inner

Piedmont

Belt

Charlotte

Belt

Belt

Subbasin

Tr-DCB

Kings

Mtn.

Gold Hill

shear zone

CS

Belt

Milton

Sauratown Mtn.

ant.

SR Tr-DRB

Sauratown Mtn. ant.

SR

Tr-DCB

Tr-DRB

CS

CP

Sauratown Mountains anticlinorium

Smith River allochthon

Davie County Triassic basin

Dan River Triassic basin

Carolina Slate Belt

Western margin of Coastal Plain Province

Physiographic province boundary

Thrust fault with teeth on upthrown block

Piedmont Coastal Plain

Blue Ridge

CP

34

35

36

84 83 82 81 80 79 78 77 76

Tr-Wadesboro

CS

Brevard fault zone

CP

CP

TENNESSEE

VIRGINIA

SOUTH CAROLINA

GEORGIA

EXPLANATION

Carolina

Slate

Belt

Eastern

Slate

Belt

Raleigh

Sanford

-Durham

Wake

Co.

0 25 50 75 100 MILES

0 25 50 75 100 KILOMETERS

Atlantic

Ocean

EXPLANATION

MIF

GNM

CPL

CPL

GNF

MVF

TRI

TRI

MIM

MIM

IMI

CPL

CPL

MVF

MIM

CPL

MIF

MVF

MVF

MIF

MVF

GNF

   Water-Resources Data and Hydrogeologic Setting for Research Stations in the Piedmont and Blue Ridge, 2000–2004
Well and Surface-Water Station Numbering 

System 

Wells and surface-water stations installed by the USGS 

are given unique identification numbers based on geographic 

location. A latitude-longitude system is used for wells and a 

downstream-order system is used for surface-water stations. 

The latitude and longitude of each well cluster and the 

surface-water station at the LWRRS were determined by 

using a differential global positioning system receiver and are 

considered accurate to within a few feet (Chapman and others, 

2005).

Wells were assigned a 15-digit site number based on the 

latitude and longitude of each well or, in the case of this study, 

well cluster. The latitude and longitude constitute the first 13 

digits, respectively, and are followed by a 2-digit sequence 

number used to distinguish between wells at the same location. 

Each well in a cluster has the same site-identification number 

except for the last 2 digits. Typically, the assigned sequence 

numbers begin with 01 for the shallowest well and progress 

with well depth. Thus, the deeper the well, the higher the 

sequence number (Chapman and others, 2005). 

The wells in this study were also assigned a local 

identifier, which consists of a two-letter county code followed 

by a three-digit sequence number. For example, wells in Wake 

County are identified by the prefix “WK” followed by three 

numbers assigned sequentially. The station name includes 

the site identifier (Lake Wheeler Road research station), well 

descriptor, and number. The well descriptors used in this study 

are as follows: MW for monitoring well, PW for pumping 

well, PZ for piezometer, GP for geoprobe, and WL for water 

level. For the purpose of this study, GP and WL are the same 

as piezometers or aquifer-test wells. Following the well 

descriptor is a cluster number and a letter, which indicates the 

aquifer section or zone that is being monitored: S for shallow 

zone (regolith), I or T for transition zone, and D for deeper 

zone (bedrock). For example, well MW–1S is a monitoring 

well in cluster 1 and is completed in the shallow regolith zone 

(Chapman and others, 2005).

The downstream order number or station number 

assigned to a surface-water station is based on the location 

of the station in the downstream direction along the main 

stem of the stream. The first two digits of the 8- to 10-digit 

station number identify the hydrologic unit (U.S. Geological 

Survey, 1974, 1975) used by the USGS to designate the major 

drainage system. The next 6 digits indicate the downstream 

order within the major drainage system. An additional 2 digits 

are added at the end of the station number in areas of high 

station density (Chapman and others, 2005). 

Borehole Geophysical Logging 

Borehole geophysical logs were collected in three 

phases. The first phase of geophysical logging included 

the collection of traditional logs—caliper, natural gamma, 

electrical (resistance, short-normal, long-normal, and lateral 

resistivity), and fluid (temperature, fluid resistivity) logs. 

The second phase of logging included the measurement of 

vertical flow near fracture zones using a heat-pulse flowmeter, 

with a measurement range of about 0.01 to 1.5 gallons per 

minute (gal/min; U.S. Geological Survey, 2005b). Heat-pulse 

flowmeter logging was conducted under ambient and(or) 

stressed conditions. Stressed conditions were created by 

pumping the well at a constant rate depending on well yield 

or by drawing the water level down and logging during 

recovery. The third phase of logging included the collection of 

a borehole image using an oriented digital camera, the optical 

televiewer (OTV). The OTV data enable the identification 

of lithology type (felsic or mafic), rock-foliation orientation, 

and fracture orientation. The orientation data are displayed 

in tadpole plots, where dip angle is plotted as a circle and 

azimuth direction is plotted as a line segment. The OTV 

data were corrected for magnetic declination and borehole 

deviation (azimuth and inclination angle). All geophysical logs 

collected and reported here are referenced to feet below land 

surface (Chapman and others, 2005).

Continuous Monitoring 

Continuous monitoring of water levels, stream stage, 

and water quality were conducted at the four research stations 

included in this report. The periods of record for the data 

collection are described in the individual research station 

sections of the report. Data were collected at a specified 

interval (hourly or 15-minute) and transmitted by satellite 

every 4 hours to a USGS database for processing and then 

made accessible in the USGS National Water Information 

System (NWIS) database from the USGS North Carolina 

Water Science Center Web page http://waterdata.usgs.

gov/nc/nwis/. Ground-water levels were measured hourly at all 

sites by using a submersible pressure transducer or a float and 

tape system with an incremental encoder. Stream stage was 

measured every 15 minutes by using a gas-purge system and 

nonsubmersible pressure transducer. Water-quality samples 

were collected hourly in the wells and every 15 minutes at 

the surface-water sites by using multiparameter water-quality 

probes. Ground-water and surface-water data collected at the 

study sites during water years 2002–04 are published in USGS 

annual data reports (Howe and others, 2003, 2004, and 2005).

A network of continuous ground-water-level recording 

stations was established in 12 wells at 3 research stations. 

Both the pressure transducers and floats were checked 

periodically against a steel or electric tape to ensure accurate 

readings. Water-level data are stored in NWIS relative to feet 

below land surface. In this report, ground-water-level data are 

presented in feet above the North American Vertical Datum of 

1988 (NAVD 88). 

Continuous surface-water stage recorders were 

established on a stream at two research stations—LWRRS and 

UPRS. Fifteen-minute stage (water-level) data were obtained 

Methods of Data Collection 
using a gas-purge system. The system is equipped with a builtin compressor and nonsubmersible pressure transducer. An 

orifice mounted in the stream channel is connected by an air 

line to the gas-purge system, which is located in an instrument 

shelter on the bank. Every 15 minutes, the compressor purges 

any air that may be in the line, and the pressure transducer 

records a pressure reading. The reading then can be referenced 

to stage height by using the actual water level on an outside 

staff gage. Both the orifice and the outside staff gage are 

anchored in the stream with a 2-inch protective steel pipe. In 

this report, stage data are presented in feet above NAVD 88.

A network of continuous ground-water-quality stations 

was established in eight wells and at two surface-water 

stations. Water-quality data were collected hourly in wells 

and at 15-minute intervals at the surface-water sites by 

using multiparameter water-quality probes. The following 

water-quality properties were measured: water temperature, 

dissolved oxygen (DO), pH, and specific conductance (SC). 

The water-quality probes were inspected and cleaned at least 

once a month according to USGS guidelines (Wagner and 

others, 2006).

All of the water-quality probes and pressure transducers 

are connected to a data-collection platform (DCP) where the 

data are recorded and transmitted. Separate DCPs were used 

for the wells and for the streams. Each DCP was powered by 

a 12-volt battery and equipped with a solar panel to recharge 

the battery. Each DCP is housed in a sealed aluminum shelter 

and grounded with a copper wire for surge and lightning 

protection. Wiring is buried 6–12 inches below ground and is 

protected by flexible steel tubing. 

Periodic Water-Level Measurements

Periodic ground-water levels were measured monthly 

or bimonthly at all of the wells at each research station to 

identify seasonal ground-water trends in each of the three 

zones (regolith, transition zone, and fractured bedrock) and 

to qualitatively describe vertical hydraulic gradients between 

wells in each cluster. Measurements were made using either 

a steel tape or an electric water-level tape from a specified 

measuring point (MP) on top of the well casing. The MP and 

land surface at each well were surveyed, and the altitudes 

were tied in to a local surveyor’s concrete monument or an 

established benchmark in order to determine the MP and 

water-level altitude above NAVD 88. Typically, water levels 

are recorded in feet below land surface. Water-level data were 

entered into the USGS Ground Water Site Inventory (GWSI) 

database and are available online at http://nwis.waterdata.usgs.

gov/nc/nwis/gwlevels, and in USGS annual data reports (Howe 

and others, 2003, 2004, and 2005). In this report, periodic 

ground-water levels are presented in feet above NAVD 88.

Slug Tests

Rising and falling slug tests were performed on 38 of the 

monitoring wells installed as part of the PMREP to assess the 

hydraulic conductivity at the well-site locations. Either solid 

polyvinyl chloride (PVC) slugs or PVC bailers were used to 

displace water in the wells. The solid slug or bailer was rinsed 

with distilled water before use in each well. A submersible 

pressure transducer with an integrated electronic data logger 

was used to measure water-level fluctuations during each 

test. A laptop computer was used to monitor and download 

the transducer readings. Water-level data recorded on the 

transducer data logger were verified with manual water-level 

measurements.

When the solid slug was used, both falling (slug-in) and 

rising (slug-out) head data were analyzed. When a bailer was 

used, only rising (slug-out) head data were analyzed. The 

falling head slug test measured the rate at which water levels 

returned to static conditions after the introduction of the solid 

PVC slug. The rising head slug test measured the recovery of 

water levels to static conditions after the slug was removed. 

Efforts were made to avoid splashing effects during the 

introduction of the slug below the water level. The tests were 

terminated after water levels recovered to within 95 percent of 

the pre-test, static level. 

The slug-test data for this investigation were analyzed 

using the Bouwer and Rice (1976) method. The Bouwer 

and Rice method accounts for partial penetration effects and 

changing aquifer thickness (water-table conditions). A basic 

assumption of this analytical method is that the aquifer is 

representative of a porous media and is considered isotropic, 

having no directional variation in hydraulic properties within 

the zone being tested. Additional assumptions are that the 

effects of elastic storage can be neglected and that the position 

of the water table does not change during the slug test (Butler, 

1998). Spreadsheets developed by Halford and Kuniansky 

(2002) were used for analytical interpretations of slug-test data 

(Chapman and others, 2005).

Water-Quality Sampling and Laboratory 

Analysis

Water-quality samples were collected from each 

monitoring well and nearby stream or lake at each research 

station by following standard USGS protocols (Wilde 

and others, 1999). Sampling methods included the use of 

submersible pumps and peristaltic pumps. Water-quality 

properties (pH, SC, DO, and temperature) were monitored 

continuously using a multiparameter water-quality instrument 

and flowthrough chamber as ground water was removed from 

the well. Prior to sample collection, at least three well volumes 

of ground water were removed from the 4-inch diameter, 

shallow, screened wells tapping the regolith and transition 

zone. For the deeper, 6-inch diameter, open-borehole bedrock 

wells, extracting three volumes of ground water prior to 

 Water-Resources Data and Hydrogeologic Setting for Research Stations in the Piedmont and Blue Ridge, 2000–2004
sample collection was impractical when using the submersible 

sampling pumps. For these wells, a minimum of one volume 

of casing water was removed, and water-quality properties 

were allowed to stabilize prior to sample collection. Pumps 

were placed near the more dominant fracture zones (Chapman 

and others, 2005). Analytical results of the water-quality 

sampling are published in USGS annual data reports (Howe 

and others, 2003, 2004, and 2005). 

A multifunction Bedrock-Aquifer Transportable Testing 

Tool (BAT3; Shapiro, 2001) was used to collect waterquality samples at LWRRS and UPRS. The BAT3 allows 

discrete intervals of a borehole to be isolated hydraulically 

for geochemical sampling by using two inflatable packers 

that seal against the borehole wall; the spacing between the 

two packers defines the test interval in the borehole (Shapiro, 

2001). The equipment is configured with a submersible pump 

located between the packers to withdraw water from the test 

interval in order to collect water-quality samples. The length 

of the test interval and the depth at which water-quality 

samples are collected were determined on the basis of the 

location of fractures intersecting the borehole, as identified by 

using borehole geophysical logs. A complete discussion of the 

downhole components of the BAT3 and its operation is given 

in Shapiro (2001).

Water samples were analyzed by the USGS National 

Water Quality Laboratory in Denver, Colorado. The waterquality constituents analyzed include major ions, nutrients, 

metals, radon 222 (gas), and radiochemicals. Of these, only 

samples for major ions and nutrients were collected during 

each sampling event. Water samples for all other constituents 

were collected intermittently (Chapman and others, 2005).

Statistical Analysis of Water-Quality Data

Box plots, Piper diagrams, and Stiff diagrams were used 

to analyze the statistical and geochemical variability in the 

periodic water-quality data. Prior to the statistical analysis, a 

quality-assurance check was conducted on the water-quality 

data. A mass balance with less than 10-percent difference for 

the major cations and anions was considered acceptable, and 

only these data were used in the statistical analysis. 

Box plots statistically categorize data, identify outliers, 

and can be an effective means of comparing values between 

data sets. The box encompasses the interval between the first 

and third quartiles, also known as the interquartile range. 

The median is represented by a horizontal line within the 

rectangular box. The minimum and maximum values of the 

data set are represented by a whisker attached to a vertical line 

drawn from the first and third quartiles, respectively, to those 

values. A data point is a suspect outlier if it lies between 1.5 

and 3 times the interquartile range, and highly suspect outliers 

are data points that occur at more than 3 times the interquartile 

range (Sincich, 1993). 

Water-quality data also can be compared using Piper 

trilinear diagrams (Piper, 1953) and Stiff diagrams (Stiff, 

1951). In a Piper diagram, the percentages of cations are 

plotted in the left trilinear diagram, and the percentages of 

anions are plotted in the right trilinear diagram. The diamondshaped middle diagram plots the cations and anions together. 

Stiff diagrams show the dominant milliequivalent-per-liter 

concentrations of anions and cations present in the collected 

samples. In this report, water-quality data are presented by 

surface water and by ground-water-system zone (regolith, 

transition zone, and bedrock).

Lake Wheeler Road Research Station

Site Description and Geology

The Lake Wheeler Road research station (LWRRS) in 

Wake County was the first hydrogeologic research station 

installed as part of the North Carolina PMREP study (fig. 2). 

The LWRRS is located at the North Carolina State University 

(NCSU) Lake Wheeler Road Field Laboratory, which also 

includes the Soil and Water Environmental Technology 

Center (SWETC). The study area encompasses approximately 

7 acres, about 5 miles southwest of the center of Raleigh, NC. 

 The LWRRS lies in the Raleigh litho-tectonic belt in the 

eastern Piedmont Physiographic Province and is underlain 

by a metamorphosed felsic gneiss that is part of the Raleigh 

Formation (Parker, 1979; Heller, 1996; fig. 2). Felsic gneiss 

represents about 20 to 30 percent of the geologic setting of the 

Piedmont and Blue Ridge Provinces in North Carolina. The 

LWRRS was selected for study (Daniel and Dahlen, 2002) 

to evaluate the effects of felsic gneiss rock type and steeply 

dipping foliation on ground-water quality, the thickness and 

composition of the regolith, the thickness and characteristics 

of the transition zone, and the development and characteristics 

of bedrock fractures (Chapman and others, 2005). Work 

conducted from April 2001 to September 2004 at the LWRRS 

included the collection and logging of three soil and rock 

core samples totaling 453 feet (ft) and the installation of 10 

observation wells grouped into three clusters aligned along 

a transect. Three piezometers and one designated bedrock 

pumping well were installed for water-level and aquifer-test 

monitoring. Additional work included the installation of a 

real-time data-collection platform for continuous monitoring 

of water levels and water quality in one of the well clusters, 

monthly collection of water levels, semiannual sampling of 

wells, a 55-hour aquifer test in a bedrock well, slug tests, and 

borehole geophysical logging.

Well Construction

Three ground-water monitoring-well clusters were 

constructed, along with an aquifer-test well and three 

regolith piezometers (fig. 3). Well-cluster locations were 

Lake Wheeler Road Research Station 
selected to obtain water-quality and water-level data along a 

topographic transect in areas of recharge and discharge based 

on conceptual models developed for the slope-aquifer system 

(LeGrand and Nelson, 2004). During this study, 14 wells and 

piezometers were installed at the LWRRS (table 1). Criteria 

for well locations included topographic setting, accessibility, 

and site boundaries. Cross-section A–A', generally constructed 

along the well transect from well cluster MW–1 to well 

cluster MW–3, is depicted in figure 4A. Cross-section B–B', 

constructed along the well transect from PW–1 to an unnamed 

tributary, is depicted in figure 4B. Well cluster MW–3 is 

located in a conceptual recharge area, and well cluster MW–1 

is located in a discharge area near the unnamed tributary. 

Four other wells (PW–1, PZ–1, PZ–2, and PZ–3) were 

installed to provide additional data during aquifer tests and for 

hydrogeologic site characterization.

Each well cluster at the LWRRS consists of at least three 

wells—a shallow well to monitor ground-water conditions in 

the regolith, a transition-zone well to monitor ground-water 

conditions in partially weathered rock and open fractures near 

the top of bedrock, and a deeper well to monitor ground water 

in the fractured bedrock (fig. 4). Well-construction information 

is provided in table 1. Well cluster MW–2 contains a fourth 

well (MW–2T) completed in the transition zone. Also, an 

inflatable packer was installed in well MW–1D on July 16, 

2002, to monitor open fractures in the transition zone 

(MW–1DUZ) from 47 to 70 ft below land surface and in the 

bedrock lower fracture zone (MW–1DLZ) from 70 to 300 ft 

below land surface.

Figure 3. Aerial photograph overlaid with topographic features showing locations of well clusters, streamgaging station, 

climate station, and lines of section at the Lake Wheeler Road research station in Wake County, North Carolina.

Figure 3. Aerial photograph overlaid with topographic features showing

locations of well clusters, surface-water gage, climate station, and lines of

section at the Lake Wheeler Road research station in Wake County,

North Carolina.

PZ-2

PZ-3

MW-2

cluster

MW-2

PW-1

PZ-1

A

A‘

MW-3

cluster

A A'

EXPLANATION

PZ-1

MW-1

cluster

B‘

B

390

380

350

360

370

340

330

310

390

370

380

370

360

360

350

320

Hydrogeologic cross section

Altitude of land surface above

 NAVD 88. Contour interval

 10 feet

Unnamed tributary to Swift Creek

USGS streamgaging station

Climate station

Well and cluster number

Piezometer and number

Corehole and number

Wastewater training center

330

0 100 200 FEET

0 25 50 METERS

Base from:

1998 photograph from Wake County, North Carolina, GIS database

Contours 1993 USGS topographic sheet, Lake Wheeler Quadrangle, 1:24,000 scale

330

320

380

350

N

RAL-1

RAL-3

RAL-2

RAL-2

 Water-Resources Data and Hydrogeologic Setting for Research Stations in the Piedmont and Blue Ridge, 2000–2004
Table 1. Construction characteristics of monitoring wells and the surface-water site at the Lake Wheeler Road research station, North Carolina. 

[NAVD 88, North American Vertical Datum of 1988; MW, monitoring well; S, shallow; PVC, polyvinyl chloride casing; R, regolith; I or T, transition zone; D, deep; B, bedrock; PW, designated pumping well; Galv. Steel, galvanized steel; PZ, piezometer; na, not applicable; SW, surface water]

Site 

identification

Station name

(fig. 4)

Construction 

date

Land-surface 

altitude 

(feet above 

NAVD 88)

Casing 

material

Casing 

diameter 

(inches)

Screened interval or 

open borehole interval 

(feet below land surface) Screen type Zone monitored

from to

354356078403501 MW–1S 5/24/2001 334.38 PVC 4.0 5 20 0.01 slotted PVC R

354356078403502 MW–1I 5/29/2001 335.36 PVC 4.0 31.5 41.5 0.01 slotted PVC I

354356078403503 MW–1D 6/5/2001 338.62 PVC 6.0 47 302 Open hole B

354356078403504 MW–1DUZa 7/16/2002 338.62 PVC 6.0 47 75b Open hole T

354356078403505 MW–1DLZa 7/16/2002 338.62 PVC 6.0 75b 302 Open hole B

354359078403101 MW–2S 5/9/2001 362.00 PVC 4.0 20 40 0.01 slotted PVC R354359078403102 MW–2I 5/9/2001 361.19 PVC 4.0 40 50 0.01 slotted PVC I354359078403103 MW–2T 5/9/2001 360.44 PVC 6.0 50 80 Open hole T354359078403104 MW–2D 4/19/2001 359.77 PVC 6.0 81 601 Open hole B354404078403101 MW–3S 5/10/2001 375.02 PVC 4.0 20 35 0.01 slotted PVC R354404078403102 MW–3I 5/14/2001 375.49 PVC 4.0 45 60 0.01 slotted PVC I

354404078403103 MW–3D 5/16/2001 376.35 PVC 6.0 66 301 Open hole B354401078403401 PW–1 6/14/2001 358.07 Galv. Steel 6.0 62.5 302 Open hole B354400078403401 PZ–1 6/20/2001 354.87 PVC 2.0 30 50 0.01 slotted PVC R354402078403401 PZ–2 6/20/2001 359.09 PVC 2.0 17 37 0.01 slotted PVC R354400078403301 PZ–3 5/15/2003 358.83 PVC 2.0 32 47 0.01 slotted PVC R0208762750 Unnamed tributary 4/1/2002 326.87 na na na na na SW

aZone isolated from the open borehole using a single packer (UZ, upper zone; LZ, lower zone).bDepth of packer.

Lake Wheeler Road Research Station 
Figure 4. Generalized hydrogeologic cross sections A–A’ and B–B’ along 

the well transects at the Lake Wheeler Road research station, North Carolina 

(section locations are shown in figure 3).

Foliation

Foliation

Data collection

platform (DCP)

1S 1I 1D

MW-1

cluster

2D2T 2S2I

MW-2

cluster

3S

Land surface

3D3I

MW-3

cluster

Shallow regolith

Open

borehole

Well casing

MW-1DLZ

MW-1DUZ

Transition zone

Bedrock

Shallow regolith

Screen

Well casing

Screen

Bottom of MW-2D

at -241 feet

0 100 200 300 400 FEET

0 20 40 60 80 100 METERS

2S 2T 2D 2I

MW-2

cluster

Land surface

Open

borehole

Bedrock

PZ-2

PW-1

PZ-1 PZ-3

?

?

ALTITUDE, IN FEET ABOVE OR BELOW NAVD 88 ALTITUDE, IN FEET ABOVE OR BELOW NAVD 88

Vertical exaggeration = 2 times scale

B B'

Unnamed

tributary

? ? ?

Transition zone

Unnamed

tributary

0 100 200 300 400 FEET

0 20 40 60 80 100 METERS

400

350

300

250

200

150

100

50

0

Bottom of MW-2D

at -241 feet

400

350

300

250

200

150

100

50

0

Figure 4. Generalized hydrogeologic cross sections A - A’ and B - B‘ along well transects at the Lake Wheeler 

Road research station, North Carolina (locations of sections A - A’ and B - B’ shown in figure 3).

Vertical exaggeration = 2 times scale

A A'

-100

-200

-300

-100

-200

-300

10 Water-Resources Data and Hydrogeologic Setting for Research Stations in the Piedmont and Blue Ridge, 2000–2004
Water-Resources Data

Borehole geophysical logs were collected from all four 

bedrock wells and the transition-zone well MW–2T at the 

LWRRS. Data collected from these wells include caliper and 

natural gamma logs, short-normal and long-normal resistivity 

logs, fluid-temperature and fluid-resistivity logs, heat-pulse 

flowmeter data (both ambient and pumping conditions), and 

OTV images (figs. 5–10). 

Monthly water levels have been measured in all 14 wells 

at the LWRRS since July 2001 except well PZ–3, which has 

been measured since May 2003 (fig. 11). The period of record 

discussed in this report is from July 2001 through September 

2004. Ground-water altitudes at well cluster MW–1 ranged 

from about 332 to 334 ft in the shallow and transition zones 

and about 333 to 336 ft in the bedrock zone. The water-level 

altitudes in the bedrock zone were consistently higher than 

water-level altitudes in the shallow and transition zones at well 

cluster MW–1. Ground-water altitudes at well cluster MW–2 

ranged from about 331 to 335 ft in the shallow and transition 

zones and from about 328 to 330 ft in the bedrock zone. The 

water-level altitudes in the bedrock zone were consistently 

lower than water-level altitudes in the shallow and transition 

zones at well cluster MW–2. Ground-water altitudes at well 

cluster MW–3 ranged from about 348 to 352 ft in all three 

zones. The water-level altitudes in the shallow zone were 

consistently lower than water-level altitudes in the transition 

and bedrock zones at well cluster MW–3. Ground-water 

altitudes in the well PW–1 ranged from about 334 to 337 ft. 

Ground-water altitudes in the piezometers ranged from about 

340 to 343 ft in PZ–1 and PZ–3, and from about 344 to 348 ft 

in PZ–2. Detailed summaries of ground-water-level data 

recorded in the LWRRS wells for water years 2001–04 are 

published in USGS annual data reports for North Carolina 

(Howe and others, 2002, 2003, 2004, and 2005). 

Continuous ground-water levels were recorded in five 

wells, and stage was recorded in a nearby stream (unnamed 

tributary to Swift Creek, station 0208762750). Ground-water 

levels were recorded hourly in all three wells in cluster MW–1 

from December 2001 to June 2004 (fig. 12) and in bedrock 

wells MW–2D from May to September 2003 and MW–3D 

from February to September 2003 (fig. 13). Stage in the 

unnamed tributary was recorded at 15-minute intervals from 

April 2002 to September 2004. For purposes of comparison to 

well cluster MW–1, continuous stage in the unnamed tributary 

was plotted hourly from April 2002 to June 2004 (fig. 12).

Slug tests were conducted at the LWRRS in October 2001 

and February 2003 (Chapman and others, 2005). A 5-ft long, 

3-inch or a 3-ft long, 1.5-inch diameter PVC bailer or a 5-ft

long, 2.5-inch diameter solid PVC slug was used to displace 

water in the wells. The slug tests were conducted to obtain 

estimates of hydraulic conductivity in the aquifer zones tapped 

by the wells—the regolith, transition zone, and bedrock. The 

estimates obtained are representative of conditions in the 

immediate vicinity of the tested wells. The wells and intervals 

tested, and the hydraulic conductivity values are listed in 

table 2.

Table 2. Analytical results of slug tests in 

wells at the Lake Wheeler Road research 

station, North Carolina.

Well 

number

Screened/open 

interval (feet 

below land 

surface)

Hydraulic 

conductivity 

(feet per day)

Regolith wells

MW–1S 5–20 0.8

MW–2S 20–40 0.6

MW–3S 20–35 3.0

PZ–1 30–50 1.0

PZ–2 17–37 4.0

Transition-zone wells

MW–1I 31.5–41.5 1.2

MW–2I 40–50 0.5

MW–3I 45–60 0.7

MW–2T 50–80 0.2

Bedrock wells

MW–1D 47–302 0.3

MW–2D 81–60 1.1

MW–3D 66–301 0.04

PW–1 62.5–302 0.05

Water-quality samples were collected from the unnamed 

tributary and all wells (excluding PZ–1, PZ–2, and PZ–3) at 

the LWRRS. To date (2006), five sets of water-quality samples 

have been collected from well cluster MW–1, four sets each 

from well clusters MW–2 and MW–3 and from well PW–1, 

and three sets from the unnamed tributary. Water-qualitydata results are displayed in Piper diagrams for all sampling 

dates (fig. 14) and in Stiff diagrams for May 2002 (fig. 15). 

Major ion geochemistry in periodic ground-water-quality 

samples from the shallow and transition-zones and in the 

unnamed tributary samples is shown in figure 14A; major 

ion geochemistry in ground-water samples from the openborehole bedrock wells at the LWRRS is shown in figure 14B. 

Ranges of water-quality-data results for all sampling dates are 

displayed in box plots (figs. 16–18).

Continuous water-quality data were collected in four 

zones in the MW–1 cluster and in the unnamed tributary. 

Hourly data from wells MW–1S (shallow regolith), MW–1I 

(transition zone), and MW–1D (bedrock) were collected from 

December 2001 to June 2004 (figs. 19–21). An inflatable 

packer was installed in MW–1D to isolate a shallow fracture 

zone within the transition zone (MW–1DUZ; fig. 22) 

from July 2002 to November 2003. Fifteen-minute data 

were collected to measure temperature, pH, SC, and DO 

concentrations in the unnamed tributary from April 2002 

to June 2004 (fig. 23). Water temperature at well cluster 

Lake Wheeler Road Research Station 11
Figure 5. Geophysical logs of bedrock well MW–1D at the Lake Wheeler Road research station, North Carolina.

0

102030405060708090

100110120130140150160170180190200210220230240250260270280290300

0 90

Fracture/Foliation

Dip angle (degrees)

5 12

Caliper (inch)

Note: pump was 

set at 30 feet 

Res (FL) (OHM-M)

66 70

Temperature

(Degrees Fahrenheit)

110 120

0 0.2

0 1

Flow - pumping

Heat Pulse Flowmeter

(gal/min)

Flow - ambient 

DEPTH, IN FEET BELOW LAND SURFACE

DEPTH, IN FEET BELOW LAND SURFACE

0102030405060708090100110120130140150160170180190200210220230240250260270280290300

Optical Televiewer Image

0 600

Gamma Log (APIU)

PVC Casing

0 0 90 180 270

N E S W N

Res (64N) (OHM-M)

1,000 4,000

Res (16N) (OHM-M)

1,000 4,000

N

S

EW

Example of tadpoleshowing dip azimuth

*Image obtained

in 6-inch

diameter well 

Camera

Lines

Figure 5. Geophysical logs for bedrock well MW-1D at the Lake Wheeler Road research station, North Carolina.

Water-bearing

fractures

Ambient and

pumping inflow

EXPLANATION

Primary fractureSecondary fractureFoliationAmbientPumping

Water level

12 Water-Resources Data and Hydrogeologic Setting for Research Stations in the Piedmont and Blue Ridge, 2000–2004
Figure 6. Geophysical logs of transition-zone fractures (MW–1DUZ) in well MW–1D at the Lake Wheeler Road research 

station, North Carolina.

47

48

49

50

51

52

53

54

55

56

57

58

59

60

61

62

63

64

65

66

67

68

DEPTH, IN FEET BELOW LAND SURFACE

47

48

49

50

51

52

53

54

55

56

57

58

59

60

61

62

63

64

65

66

67

68

DEPTH, IN FEET BELOW LAND SURFACE

Note: pump was 

set at 30 feet 

Figure 6. Geophysical logs of transition-zone fractures (MW-1DUZ) in well MW-1D at the Lake 

Wheeler Road research station, North Carolina.

0 90 5 12

Fracture/Foliation

Dip angle (degrees) Caliper (inch)

Res (64N) (OHM-M)

1,000 4,000

Res (16N) (OHM-M)

1,000 4,000

0 0.2

0 1

Heat Pulse Flowmeter

(gal/min)

Flow - ambient

Flow - pumping

N

S

EW

Camera

Line

Example of tadpole

showing dip azimuth

*all indicate upflow

Optical Televiewer Image

0 0 90 180 270

N E S W N

*Image obtained 

in 6-inch 

diameter well

Primary fracture

Foliation

Ambient

Pumping

EXPLANATION

Water-bearing

fractures

Water-bearing

fractures

Ambient and

pumping inflow

Lake Wheeler Road Research Station 13
Figure 7. Geophysical logs of transition-zone well MW–2T at the Lake Wheeler Road research station, North Carolina.

48

50

52

54

56

58

60

62

64

66

68

70

72

74

76

78

DEPTH, IN FEET BELOW LAND SURFCAE

48

50

52

54

56

58

60

62

64

66

68

70

72

74

76

78

DEPTH, IN FEET BELOW LAND SURFACE

*Image obtained 

in 6-inch 

diameter well

Figure 7. Geophysical logs for transition-zone well MW-2T at the Lake Wheeler Road research

station, North Carolina.

Optical Televiewer Image

0 0 90 0 90 6 10  180 270

Fracture/Foliation

Dip angle (degrees) Caliper (inch)

0 400

Gamma Log (APIU)

Camera

Line

N E S W N

N

S

EW

Example of tadpole

showing dip azimuth

Secondary fracture

Primary fracture

Foliation

EXPLANATION

14 Water-Resources Data and Hydrogeologic Setting for Research Stations in the Piedmont and Blue Ridge, 2000–2004
Figure 8. Geophysical logs of bedrock well MW–2D at the Lake Wheeler Road research station, North Carolina.

Optical Televiewer Image

0 600

Gamma Log (APIU)

0 0 90 180 270

N E S W N

0 90

Fracture/Foliation

Dip angle (degrees)

6 7

Caliper (inch)

Res (64N) (OHM-M)

1,000 4,000

Res (16N) (OHM-M)

1,000 4,000

Res (FL) (OHM-M)

0 50

Temperature 

(Degrees Fahrenheit)

60 62

*Image obtained 

in 6-inch 

diameter well

0 1

Flow - pumping

0

50

100

150

200

250

300

350

400

450

500

550

600

DEPTH, IN FEET BELOW LAND SURFACEDEPTH, IN FEET BELOW LAND SURFACE

PVC Casing

Figure 8. Geophysical logs for bedrock well MW-2D at the Lake Wheeler Road research station, North Carolina. 

0

50

100

150

200

250

300

350

400

450

500

550

600

Flow - ambient

0 0.03

Heat Pulse Flowmeter 

(gal/min)

Camera

Line

N

S

EW

Example of tadpole

showing dip azimuth

Note: pump was 

set at 30 feet Secondary fracture

Primary fracture

Foliation

Ambient

Pumping

EXPLANATION

Water level

Ambient and

pumping inflow

Lake Wheeler Road Research Station 15
Figure 9. Geophysical logs of bedrock well MW–3D at the Lake Wheeler Road research station, North Carolina. DEPTH, IN FEET BELOW LAND SURFACE

DEPTH, IN FEET BELOW LAND SURFACE

PVC Casing

Figure 9. Geophysical logs for bedrock well MW-3D at the Lake Wheeler Road research station, North Carolina. 

0

20

40

60

80

100

120

140

160

180

200

220

240

260

280

300

0

20

40

60

80

100

120

140

160

180

200

220

240

260

280

300

Optical Televiewer Image

0 600

Gamma Log (APIU)

0 0 90 180 270

N E S W N

0 90

Fracture/Foliation

Dip angle (degrees)

6 7

Caliper (inch)

Res (64N) (OHM-M)

0 4,000

Res (16N) (OHM-M)

0 4,000

Res (FL) (OHM-M) Flow - pumping

55 65

Temperature 

(Degrees Fahrenheit)

40 80 0 0.5

Flow - ambient

0 0.02

Heat Pulse Flowmeter 

(gal/min)

*Image obtained 

in 6-inch 

diameter well

Camera

Line

N

S

EW

Example of tadpole

showing dip azimuth

Note: pump was 

set at 30 feet Secondary fracture

Primary fracture

Foliation

Ambient

Pumping

EXPLANATION

Water level

Water-bearing

fracture

Water-bearing

fracture

Ambient and

pumping inflow

Ambient and

pumping inflow

16  Water-Resources Data and Hydrogeologic Setting for Research Stations in the Piedmont and Blue Ridge, 2000–2004
Figure 10. Geophysical logs of bedrock well PW–1 at the Lake Wheeler Road research station, North Carolina. DEPTH, IN FEET BELOW LAND SURFACE

DEPTH, IN FEET BELOW LAND SURFACE

Galvinized

Steel Casing

Optical Televiewer Image

0 0 90 180 270

N E S W N

0 600

Gamma Log (APIU)

0 90

Fracture/Foliation

Dip angle (degrees)

6 7

Caliper (inch) Flow - ambient

0 0.02

Heat Pulse Flowmeter 

(gal/min)

Res (64N) (OHM-M)

0 4,000

Res (16N) (OHM-M)

0 4,000

Res (FL) (OHM-M)

50 70

Temperature 

(Degrees Fahrenheit)

58 62

0

20

40

60

80

100

120

140

160

180

200

220

240

260

280

300

0

20

40

60

80

100

120

140

160

180

200

220

240

260

280

300

Figure 10. Geophysical logs for bedrock well PW-1 at the Lake Wheeler Road research station, North Carolina. 

N

S

EW

Example of tadpole

showing dip azimuth

*Image obtained 

in 6-inch 

diameter well

Camera

Line

Secondary fracture

Primary fracture

Foliation

Ambient

EXPLANATION

Water level

Water-bearing

fracture

Lake Wheeler Road Research Station 17
Figure 11. Periodic ground-water levels recorded in well clusters (A) MW–1, (B) MW–2, (C) MW–3, and (D) the aquifer-test well and piezometers at the Lake Wheeler Road 

research station, North Carolina.

MW-1S MW-1I MW-1D MW-1D UZ MW-1D LZ 

MW-2S MW-2I MW-2T MW-2D 

MW-3S MW-3I MW-3D 

PW-1 PZ-1PZ-2PZ-3

337336335334333332331330

WATER-LEVEL ALTITUDE, IN FEET ABOVE NAVD 88

336335334333332331330329328327326

WATER-LEVEL ALTITUDE, IN FEET ABOVE NAVD 88

A. B.

354353352351350349348347

WATER-LEVEL ALTITUDE, IN FEET ABOVE NAVD 88

350348346344342340338336334332330

WATER-LEVEL ALTITUDE, IN FEET ABOVE NAVD 88

C. D.

JULY 1 OCT. 1 

2001

WATER 

YEAR

2002

WATER YEAR 

2003

WATER YEAR 

2004

WATER YEAR 

JAN. 1 APR. 1 JULY 1 OCT. 1 JAN. 1 APR. 1 JULY 1 OCT. 1 JULY 1 OCT. 1 JAN. 1 APR. 1 JULY 1 OCT. 1 

2001

WATER

YEAR

2002

WATER YEAR 

2003

WATER YEAR 

2004

WATER YEAR 

JAN. 1 APR. 1 JULY 1 OCT. 1 JAN. 1 APR. 1 JULY 1 OCT. 1 JULY 1 OCT. 1 JAN. 1 APR. 1 

JULY 1 OCT. 1 

2001

WATER 

YEAR

2002

WATER YEAR 

2003

WATER YEAR 

2004

WATER YEAR 

JAN. 1 APR. 1 JULY 1 OCT. 1 JAN. 1 APR. 1 JULY 1 OCT. 1 JULY 1 OCT. 1 JAN. 1 APR. 1 JULY 1 OCT. 1 

2001

WATER 

YEAR

2002

WATER YEAR 

2003

WATER YEAR 

2004

WATER YEAR 

JAN. 1 APR. 1 JULY 1 OCT. 1 JAN. 1 APR. 1 JULY 1 OCT. 1 JULY 1 OCT. 1 JAN. 1 APR. 1 

Figure 11. Periodic ground-water levels recorded in well clusters (A) MW-1, (B) MW-2, (C) MW-3, and (D) the aquifer-test wells at the Lake Wheeler Road research station, North Carolina.

18  Water-Resources Data and Hydrogeologic Setting for Research Stations in the Piedmont and Blue Ridge, 2000–2004
Figure 12. Hourly ground-water levels recorded in well cluster MW–1 and hourly stage recorded at the tributary site at the 

Lake Wheeler Road research station, North Carolina.

337

336

335

334

333

332

331

330

329

328

327

326

WATER-LEVEL ALTITUDE, IN FEET

2/11/1 4/13/1 6/1

2002 2003 2004

5/1 8/17/1 10/19/1 12/111/1 2/11/1 4/13/1 6/15/1 8/17/1 10/19/1 12/111/1 2/11/1 4/13/1 6/15/1 7/1

Figure 12. Hourly ground-water levels recorded in well cluster MW-1 and hourly stage recorded at the

surface-water site at the Lake Wheeler Road research station, North Carolina.

MW-1S

MW-1I

MW-1D

MW-1D UZ

MW-1D LZ

Unnamed tributary to

 Swift Creek

Lake Wheeler Road Research Station 19
Figure 13. Hourly ground-water levels recorded in bedrock wells MW–2D and MW–3D at the Lake Wheeler Road research station, 

North Carolina.

MW-3D

MW-2D

FEB. 6 MAR. 1 APR. 1 MAY 1 

2003

JUNE 1 JULY 1 AUG. 1 SEPT. 1 SEPT. 25 

Figure 13. Hourly ground-water levels recorded in bedrock wells MW-2D and MW-3D at the Lake Wheeler Road

research station, North Carolina.

353.0

352.5

352.0

351.5

351.0

350.5

350.0

MW-3D WATER-LEVEL ALTITUDE, IN FEET

332.0

331.5

331.0

330.5

330.0

329.5

329.0

MW-2D WATER-LEVEL ALTITUDE, IN FEET

20 Water-Resources Data and Hydrogeologic Setting for Research Stations in the Piedmont and Blue Ridge, 2000–2004
Figure 14. The water 

chemistry of samples from 

(A) regolith and transitionzone wells and the tributary 

site, and (B) bedrock wells 

at the Lake Wheeler Road 

research station, North 

Carolina.

Figure 14. Piper diagrams showing the water chemistry of samples from the (A) regolith and transition

-zone wells and the tributary site, and (B) bedrock wells at the Lake Wheeler Road research station,

North Carolina. 

MW-1D

MW-3D

PW-1

EXPLANATION

MW-1S 

MW-2S 

MW-3S 

TRIBUTARY 

MW-1I 

MW-2I 

MW-3I 

EXPLANATION

80

100

60

40

20

0

80

60

40

20

0

SULFATE PLUS CHLORIDE PLUS NITRATE 

80

100

60

40

20

20

0

40

60

80

0 100 100

60 40 20

CALCIUM

CATIONS 

100 80 0

20

40

60

80

100

20

40

60

80

0

20

40

60

80

MAGNESIUM

SODIUM PLUS POTASSIUM 

40 60 80

CHLORIDE PLUS NITRATE 

ANIONS

200 100

60 40 20

CALCIUM

CATIONS 

100 80

B.

A.

0 40 60 80

CHLORIDE PLUS NITRATE 

ANIONS

0 20 100

CARBONATE PLUS BICARBONATE 

0 0

20

0

40

60

80

100 100

20

40

60

80

100

20

40

60

80

0

20

40

60

80

SODIUM PLUS POTASSIUM 

CARBONATE PLUS BICARBONATE 

80

100

60

40

20

0

SULFATE 

80

100

60

40

20

0

MAGNESIUM

80

100

60

40

20

0

SULFATE 

CALCIUM PLUS MAGNESIUM 

80

100

60

40

20

80

60

40

20 SULFATE PLUS CHLORIDE PLUS NITRATE 

CALCIUM PLUS MAGNESIUM 

5/7/02

11/14/02

11/13/02

11/14/02

11/15/02

11/15/01

11/16/01

5/8/02

5/9/02

5/9/02

11/13/02

11/14/01

11/13/02

5/8/02

5/7/02

11/14/01

11/20/01

8/27/01

5/8/02

5/8/02

11/14/02

11/13/02

MW-1D UZ

MW-2T

** *

5/7/02 11/15/01

11/14/02

5/9/02

11/14/02

Lake Wheeler Road Research Station 21
Figure 15. Major ion milliequivalents in water samples collected from (A) regolith wells and the tributary site, (B) transition-zone wells, and (C) open-borehole bedrock wells at 

the Lake Wheeler Road research station, North Carolina, May 2002.

Ca

 Sodium 

Calcium

Magnesium

Ammonia, as Nitrogen 

A.

2 1 2 1

CATIONS ANIONS B.

2 1 2 1

CATIONS ANIONS

5 2.5 5 2.5

MILLIEQUIVALENTS PER LITER CATIONS ANIONS

C.

2 1 2 1

CATIONS ANIONS

 Sodium

Calcium

Magnesium

Nitrite plus Nitrate 

 Sodium 

Calcium

Magnesium

Nitrite plus Nitrate 

 Sodium

Calcium

Magnesium

Nitrite plus Nitrate 

 Sodium 

Calcium

Magnesium

Nitrite plus Nitrate 

 Sodium 

Calcium

Magnesium

Nitrite plus Nitrate 

 Sodium

Calcium

Magnesium

Nitrite plus Nitrate 

 Sodium Chloride

MW-1SMW-2SMW-3STRIBUTARY SITE 

MW-1IMW-2IMW-2T

MW-3DPW-1

MW-3IMW-1DUZ

Calcium Bicarbonate

Magnesium Sulfate

Nitrite plus Nitrate 

Chloride

Sulfate

Chloride

Sulfate

Chloride

Sulfate

Chloride

Sulfate

Chloride

Sulfate

Chloride

Sulfate

Chloride

Sulfate

 Sodium 

Calcium

Magnesium

Nitrite plus Nitrate 

 Sodium 

Calcium

Magnesium

Nitrite plus Nitrate 

 Sodium 

Calcium

Magnesium

Nitrite plus Nitrate 

Chloride

Sulfate

Chloride

Sulfate

Chloride

Sulfate

Nitrite plus Nitrate 

Ammonia, as Nitrogen 

Ammonia, as Nitrogen 

Ammonia, as Nitrogen 

Ammonia, as Nitrogen 

Ammonia, as Nitrogen 

Ammonia, as Nitrogen 

Ammonia, as Nitrogen 

Ammonia, as Nitrogen 

Ammonia, as Nitrogen 

Ammonia, as Nitrogen 

Bicarbonate

Bicarbonate

Bicarbonate

Bicarbonate

Bicarbonate

Bicarbonate

Bicarbonate

Bicarbonate

MILLIEQUIVALENTS PER LITER MILLIEQUIVALENTS PER LITER MILLIEQUIVALENTS PER LITER

Figure 15. Stiff diagrams showing major ion milliequivalents in water samples collected from (A) the regolith wells and the tributary site, (B) the intermediate-zoneand transition-zone wells, and (C) the open-borehole bedrock wells at the Lake Wheeler Road research station, North Carolina, May 2002.

Bicarbonate

Bicarbonate

22 Water-Resources Data and Hydrogeologic Setting for Research Stations in the Piedmont and Blue Ridge, 2000–2004
Figure 16. The range, median, and quartile statistical values for (A) pH, (B) specific conductance, 

and (C) dissolved oxygen for wells and the tributary site during periodic sampling events at the 

Lake Wheeler Road research station, North Carolina.

BEDROCK

(8)

TRANSITION

(9)

REGOLITH

(23)

TRIBUTARY

(3)

8

7

6

5

4

pH, IN STANDARD UNITS

700

600

500

400

300

200

100

0

SPECIFIC CONDUCTANCE, IN MICROSIEMENS PER 

CENTIMETER

10

8

6

4

2

0

DISSOLVED OXYGEN, IN MILLIGRAMS

PER LITER

Figure 16. The range, median, and quartile 

statistical values for (A) pH, (B) specific

conductance, and (C) dissolved oxygen for

wells and the tributary site during periodic

sampling events at the Lake Wheeler Road

research station, North Carolina.

A.

B.

C.

Upper detached

EXPLANATION

Lower detached

(8) Number of samples

Upper adjacent

Lower adjacent

Median

Interquartile range (IQR):

adjacent data are within

1.5 times the IQR, while

detached data are outliers.

75th percentile

25th percentile

Lake Wheeler Road Research Station 23
Figure 17. The range, median, and quartile statistical values for (A) calcium, (B) magnesium, 

and (C) sodium for wells and the tributary site during periodic sampling events at the Lake 

Wheeler Road research station, North Carolina.

BEDROCK

(8)

TRANSITION

(9)

REGOLITH

(23)

TRIBUTARY

(3)

120

100

80

60

40

20

0

CALCIUM, IN MILLIGRAMS PER LITER

12

10

8

6

4

2

0

MAGNESIUM, IN MILLIGRAMS PER LITER

31

26

21

16

11

6

1

SODIUM, IN MILLIGRAMS PER LITER 

Figure 17. The range, median, and quartile 

statistical values for (A) calcium, (B) magnesium, 

and (C) codium in the wells and the tributary 

site during periodic sampling events at the

Lake Wheeler Road research station,

North Carolina.

A.

B.

C.

Upper detached

EXPLANATION

Lower detached

Upper adjacent

Lower adjacent

Median

Interquartile range (IQR):

adjacent data are within

1.5 times the IQR, while

detached data are outliers.

75th percentile

25th percentile

(8) Number of samples

24 Water-Resources Data and Hydrogeologic Setting for Research Stations in the Piedmont and Blue Ridge, 2000–2004
Figure 18. The range, median, and quartile statistical values for (A) bicarbonate, (B) chloride, 

and (C) sulfate for wells and the tributary site during periodic sampling events at the Lake 

Wheeler Road research station, North Carolina.

BEDROCK

(8)

TRANSITION

(9)

REGOLITH

(23)

TRIBUTARY

(3)

300

250

200

150

100

50

0

BICARBONATE, IN MILLIGRAMS PER LITER

70

60

50

40

30

20

10

0

CHLORIDE, IN MILLIGRAMS PER LITER

300

250

200

150

100

50

0

SULFATE, IN MILLIGRAMS PER LITER 

Figure 18. The range, median, and quartile 

statistical values for (A) bicarbonate, (B) chloride, 

and (C) sulfate in the wells and the tributary 

site during periodic sampling events at the

Lake Wheeler Road research station,

North Carolina.

A.

B.

C.

Upper detached

EXPLANATION

Lower detached

Upper adjacent

Lower adjacent

Median

Interquartile range (IQR):

adjacent data are within

1.5 times the IQR, while

detached data are outliers.

75th percentile

25th percentile

(8) Number of samples

Lake Wheeler Road Research Station 25
Figure 19. Hourly record of (A) temperature, (B) pH, (C) specific conductance, and (D) dissolved oxygen in well MW–1S in the shallow regolith 

at the Lake Wheeler Road research station, North Carolina, December 2002 through June 2004.

No data

No data

D J F M A M J

2002 WATER YEAR 2003 WATER YEAR 2004 WATER YEAR

J A S O N D J F M A M J J A S O N D J F M A M J

5

4

3

2

1

DISSOLVED OXYGEN,

0

IN MILLIGRAMS 

PER LITER

300

250

200

150

100

50

SPECIFIC CONDUCTANCE,

IN MICROSIEMENS PER

CENTIMETER AT

25 DEGREES CELSIUS

18

17

16

15

14

13

12

WATER TEMPERATURE,

IN DEGREES CELSIUS

6.5

6.0

5.5

5.0

4.5

4.0

pH

A.

B.

C.

D.

Figure 19. Hourly record of (A) temperature, (B) pH, (C) specific conductance, and (D) dissolved oxygen in well MW-1S in the

shallow regolith at the Lake Wheeler Road research station, North Carolina, December 2002 through June 2004.

26  Water-Resources Data and Hydrogeologic Setting for Research Stations in the Piedmont and Blue Ridge, 2000–2004
Figure 20. Hourly record of (A) temperature, (B) pH, (C) specific conductance, and (D) dissolved oxygen in well MW–1I in the transition zone 

at the Lake Wheeler Road research station, North Carolina, December 2002 through June 2004. 

No data 

No data

No data 

No data 

D J F M A M J

2002 WATER YEAR 2003 WATER YEAR 2004 WATER YEAR 

J A S O N D J F M A M J J A S O N D J F M A M J

4

3

2

1

DISSOLVED OXYGEN, 

0

IN MILLIGRAMS

PER LITER 

250

200

150

100

50

16.3

16.2

16.1

16.0

15.9

15.8

15.7

WATER TEMPERATURE, 

IN DEGREES CELSIUS 

5.8

5.6

5.4

5.2

5.0

4.8

pH

A.

B.

C.

D.

Figure 20. Hourly record of (A) temperature, (B) pH, (C) specific conductance, and (D) dissolved oxygen in well MW-1I in the

intermediate zone at the Lake Wheeler Road research station, North Carolina, December 2002 through June 2004.

SPECIFIC CONDUCTANCE,

IN MICROSIEMENS PER

CENTIMETER AT

25 DEGREES CELSIUS

Lake Wheeler Road Research Station 27
Figure 21. Hourly record of (A) temperature, (B) pH, (C) specific conductance, and (D) dissolved oxygen in well MW–1D in the bedrock at the 

Lake Wheeler Road research station, North Carolina, December 2002 through June 2004 (packer was installed in July 2002; see figure 22 for 

missing data).

No data 

No data 

No data 

No data 

D J F M A M J

2002 WATER YEAR 2003 WATER YEAR 2004 WATER YEAR 

J A S O N D J F M A M J J A S O N D J F M A M J

1.2

1.0

0.8

0.6

0.4

0.2

DISSOLVED OXYGEN, 

0

IN MILLIGRAMS

PER LITER 

800

750

700

650

600

550

16.5

16.3

16.1

15.9

15.7

15.5

WATER TEMPERATURE, 

IN DEGREES CELSIUS 

6.4

6.2

6.0

5.8

5.6

5.4

pH

A.

B.

C.

D.

SPECIFIC CONDUCTANCE,

IN MICROSIEMENS PER

CENTIMETER AT

25 DEGREES CELSIUS

Figure 21. Hourly record of (A) temperature, (B) pH, (C) specific conductance, and (D) dissolved oxygen in well MW-1D in the

bedrock at the Lake Wheeler Road research station, North Carolina, December 2002 through June 2004 (packer installed in

July 2002, see fig. 22 for missing data).

28  Water-Resources Data and Hydrogeologic Setting for Research Stations in the Piedmont and Blue Ridge, 2000–2004
Figure 22. Hourly record of (A) temperature, (B) pH, (C) specific conductance, and (D) dissolved oxygen in well MW–1DUZ during installation 

of an inflatable packer at the Lake Wheeler Road research station, North Carolina, July 2002 through November 2003.

AUG.

2002 WATER YEAR 2003 WATER YEAR

JULY SEPT. OCT. NOV. DEC. JAN. FEB. MAR. APR. MAY JUNE JULY AUG. SEPT. OCT. NOV.

5

4

3

2

1

0

-1

DISSOLVED OXYGEN,

IN MILLIGRAMS 

PER LITER

800

700

600

500

400

300

16.6

16.5

16.4

16.3

16.2

16.1

16.0

15.9

15.8

15.7

15.6

15.5

WATER TEMPERATURE,

IN DEGREES CELSIUS

7.0

6.5

6.0

5.5

5.0

4.5

pH

A.

B.

C.

D.

SPECIFIC CONDUCTANCE,

IN MICROSIEMENS PER

CENTIMETER AT

25 DEGREES CELSIUS

Figure 22. Hourly record of (A) temperature, (B) pH, (C) specific conductance, and (D) dissolved oxygen in well MW-1DUZ

during installation of an inflatable packer at the Lake Wheeler Road research station, North Carolina, July 2002 through

November 2003.

Lake Wheeler Road Research Station 29
Figure 23. Fifteen-minute record of (A) temperature, (B) pH, (C) specific conductance, and (D) dissolved oxygen in the unnamed tributary at 

the Lake Wheeler Road research station, North Carolina, April 2002 through June 2004.

No data 

No data 

A M J

2002 WATER YEAR 2003 WATER YEAR 2004 WATER YEAR 

J A S O N D J F M A M J J A S O N D J F M A M J

30

20

10

0

DISSOLVED OXYGEN, 

-10

IN MILLIGRAMS

PER LITER 

500

400

300

200

100

0

-100

30

20

10

0

WATER TEMPERATURE, 

IN DEGREES CELSIUS 

9

8

7

6

5

4

3

pH

B.

A.

C.

D.

SPECIFIC CONDUCTANCE,

IN MICROSIEMENS PER

CENTIMETER AT

25 DEGREES CELSIUS

Figure 23. 15-minute record of (A) temperature, (B) pH, (C) specific conductance, and (D) dissolved oxygen in the

unnamed tributary at the Lake Wheeler Road research station, North Carolina, April 2002 through June 2002.

30 Water-Resources Data and Hydrogeologic Setting for Research Stations in the Piedmont and Blue Ridge, 2000–2004
MW–1 ranged from about 14 to 17 degrees Celsius (°C) in 

the shallow zone, from about 16 to 16.1 °C in the transition 

zone, and was a steady 16.1 °C in the bedrock zone. Specific 

conductance ranged from about 100 to 150 microsiemens 

per centimeter (μS/cm) at 25 °C in the shallow zone, from 

about 125 to 200 μS/cm in the transition zone, and from 

about 650 to 750 μS/cm in the bedrock zone. The pH ranged 

from about 5 to 5.5 in the shallow and transition zones, and 

from about 5.5 to 6.2 in the bedrock zone. Dissolved-oxygen 

concentrations ranged from about 2 to 4 milligrams per 

liter (mg/L) in the shallow and transition zones, and from 

about 0.2 to 1 mg/L in the bedrock zone (figs. 19–22). Water 

temperature in the unnamed tributary to Swift Creek ranged 

from 5 to 25 °C, SC ranged from about 50 to 300 μS/cm, pH 

ranged from about 5 to 6, and DO concentrations ranged from 

about 2 to 10 mg/L (fig. 23). 

Langtree Peninsula Research Station

Site Description and Geology

The first hydrogeologic research station installed in 

the DWQ Mooresville Region of North Carolina as part 

of the PMREP is the Langtree Peninsula research station 

(LPRS) in Iredell County (fig. 24). The LPRS is located on 

Lake Norman and the Davidson Community College Lake 

Campus (fig. 25). Lake Norman, a manmade reservoir, borders 

Langtree Peninsula to the north, west, and south. Work Creek 

and Davidson Creek border the peninsula to the north and 

south, respectively (fig. 25). The study area encompasses 

approximately 7 acres about 3.5 miles southwest of the center 

of Mooresville, NC (fig. 24).

The LPRS lies in the Charlotte litho-tectonic belt in 

the Piedmont Physiographic Province and is underlain by 

quartz diorite and biotite gneiss rock types. Regionally, the 

LPRS is representative of the intermediate metaigneous 

(MII) hydrogeologic unit (fig. 24), which represents about 

3 percent of the Piedmont and Blue Ridge Provinces in North 

Carolina (Daniel and Dahlen, 2002). The LPRS was selected 

to evaluate the effects of quartz diorite and massive (weakly 

foliated) biotite gneiss rock types with moderate to steeply 

dipping foliation on ground-water quality, thickness and 

composition of the regolith, thickness and characteristics of 

the transition zone, and the development and characteristics of 

bedrock fractures. Work conducted from September 2000 to 

September 2004 at the LPRS site included the collection and 

logging of nine soil and rock cores totaling 645 ft, installation 

of 18 observation wells grouped into six clusters aligned 

along two topographic transects (A–A' and B–B', figs. 26, 27, 

respectively), installation of 12 piezometers for water-level 

and aquifer-test monitoring, installation of a real-time DCP 

for continuous monitoring of water levels and water quality 

in a three-well cluster, monthly collection of water levels, 

semiannual sampling of wells and the lake, a 48-hour aquifer 

test, slug tests, and borehole geophysical logs.

Well Construction

Six ground-water monitoring-well clusters, each 

containing three wells, were constructed in addition to 

12 piezometers at the LPRS (fig. 25). The piezometers 

were assigned the prefix GP (geoprobe) or WL (augured), 

depending on the method of construction. Well-cluster 

locations were selected to obtain water-quality and waterlevel data along topographic transects encompassing areas of 

recharge and discharge based on conceptual models developed 

for the slope-aquifer system (LeGrand and Nelson, 2004). 

Criteria for well locations included topographic setting, 

accessibility, and site boundaries. During this study, a total 

of 32 wells (including piezometers) were installed at the 

LPRS (table 3). Cross section A–A' was constructed along 

the transect from well cluster MW–3 to well cluster MW–2 

(figs. 25, 26). Cross section B–B' was constructed along 

the transect from well cluster MW–6 to well cluster MW–1 

(figs. 25, 27). Well clusters MW–2 and MW–1 are located 

in a conceptual recharge area, and well clusters MW–3 and 

MW–6 are located in a discharge area near the lake. The 12 

piezometers were installed to provide aquifer-test data and to 

obtain detailed data to define the two-dimensional groundwater flow within the regolith.

Each well cluster at the LPRS consisted of at least three 

wells—a shallow well to monitor ground-water conditions in 

the regolith (except at well cluster MW–4); a transition-zone 

well to monitor ground-water conditions in partially weathered 

rock and open fractures near the top of bedrock; and a deeper 

bedrock well to monitor ground water in the fracturedbedrock aquifer (figs. 26, 27). Well-construction information 

is provided in table 3. Well MW–3D was abandoned in 

March 2002 due to casing collapse. Well MW–4S was 

drilled deeper in February 2002, which created an additional 

transition-zone well (4IA) at well cluster MW–4. Well MW–6I 

was abandoned in February 2002 due to well-construction 

problems, and MW–6IB was installed to replace it. Also, 

4-inch-diameter PVC liner casings were installed in bedrock 

wells MW–1D, MW–4D, and MW–6D in December 2001 

because of problems with leaky surface casings. The liners 

were installed to a depth just below the original 6-inch PVC 

surface casing and were grouted in place using cement and 

then sealed at the bottom with a butyl rubber boot. 

Langtree Peninsula Research Station  31
Figure 24. Locations of Langtree Peninsula research station, hydrogeologic units in Iredell County, and geologic belts delineated in North 

Carolina (modified from North Carolina Geological Survey, 1985; Daniel and Payne, 1990).

Base from digital files of:

U.S. Department of Commerce, Bureau of Census,

 1990 Precensus TIGER/Line Files-Political boundaries, 1991

U.S. Environmental Protection Agency, River File 3

U.S. Geological Survey, 1:100,000 scale 

SR Tr-DRB

Sauratown Mtn. ant.

SR

Tr-DCB

Tr-DRB

CS

CP

Sauratown Mountains anticlinorium

Smith River allochthon

Davie County Triassic basin

Dan River Triassic basin

Carolina Slate Belt

Western margin of Coastal Plain 

 Physiographic Province

Boundary between Blue Ridge and Piedmont

 Physiographic Provinces

Thrust fault with teeth on upthrown block

Piedmont Coastal Plain

Blue Ridge

34

35

36

84 83 82 81 80 79 78 77 76

Brevard fault zone

TENNESSEE

VIRGINIA

SOUTH CAROLINA

GEORGIA

EXPLANATION

0 25 50 75 100 MILES

0 25 50 75 100 KILOMETERS

Atlantic

Ocean

Langtree Peninsula research station

HYDROGEOLOGIC UNITS

(Daniel and Payne, 1990)

Gneiss, felsic (GNF)

Gneiss, mafic (GNM)

Igneous, felsic intrusive (IFI)

Igneous, mafic intrusive (IMI)

Metaigneous, felsic (MIF)

Metaigneous, intermediate (MII)

Metaigneous, mafic (MIM)

Metavolcanic, undifferentiated (MVU)

Quartzite (QTZ)

Iredell

Co.

N

Mooresville

GNF

GNM

MIF MIF

IFI

IMI

IMI

MIF

MII

MIM

MIM

MIM

MVU

QTZ

Lake

Norman

GNF

MIF

MIM MII

IFI

IFI

IFI

MIF

MVU

IFI

MVU MIM

IFI

Murphy

Belt

Blue

Ridge

Belt

Chauga

Belt

Inner

Piedmont

Belt

Charlotte

Belt

Belt

Subbasin

Tr-DCB

Kings

Mtn.

Gold Hill

shear zone

CS

Belt

Milton

Sauratown Mtn.

ant.

CP

Tr-Wadesboro

Carolina

Slate

Sanford

-Durham

CS

CP

CP

Belt

Eastern

Slate

Belt

Raleigh

EXPLANATION

Figure 24. Locations of Langtree Peninsula research station, hydrogeologic units in Iredell County, and geologic belts delineated in 

North Carolina (modified from NCGS, 1985; Daniel and Payne, 1990).

0 10 20 MILES

0 8 16 KILOMETERS

32 Water-Resources Data and Hydrogeologic Setting for Research Stations in the Piedmont and Blue Ridge, 2000–2004
DAVIDSON

COMMUNITY COLLEGE

LAKE CAMPUS

800

810

790

790

790

780

770

780

780

770

Figure 25. Aerial photograph and topographic map showing locations

of well clusters and lines of section at the Langtree Peninsula r esearch

station in Iredell County, North Carolina.

A A' EXPLANATION

Cross section

Altitude of land surface above

 NAVD 88. Contour interval 10 feet

Well cluster number

Piezometer and number

Buildings

Lake sampling site

800

0 200 400 FEET 

0 50 100 METERS 

Base from:

1998 photograph from Iredell County, North Carolina GIS database

Contours 1993 USGS topographic sheet, 

Lake Norman Quadrangle, 1:24,000 scale

A'

A

B'

B

N

MW-1

cluster

MW-4

cluster

MW-5

cluster

MW-3

cluster

0 5,000 10,000 FEET 

0 1,250 2,500 METERS 

Work Creek

Davidson Creek 

Lake Norman 

MW-6

cluster

MW-2

cluster

MW-2

GP-1

Woods

Woods

Lake

Norman

Pier

GP-7

GP-6 GP-8

GP-5

WL-2

WL-1

GP-2

GP-3

GP-4

GP-1

WL-3 WL-4

790

780

770

800

800

Langtree

Peninsula

Figure 25. Aerial photograph and topographic map showing locations of well clusters, lake site, and lines of section at the Langtree 

Peninsula research station in Iredell County, North Carolina.

Langtree Peninsula Research Station  33
Figure 26. Generalized hydrogeologic cross section A–A’ along the well transect at the Langtree Peninsula research station, North 

Carolina (section location is shown in figure 25).

Open borehole 

MW-3

cluster

MW-4 

cluster

MW-2 

cluster

4D 4IB 2S

2I

2D

Figure 26. Generalized hydrogeologic cross section A-A' along the well transect at the Langtree Peninsula research station, North Carolina

(section location shown in fig. 25).

Regolith

Transition zone 

Bedrock

A A'

Vertical exaggeration = 3.1 times scale

Well 

casing

Land surface

Data collection 

platform (DCP) 

900

800

700

600

500

400

300

ALTITUDE, IN FEET ABOVE NAVD 88

4IA/4S

4S

4IA

0 250 500 750 1,000 FEET

0 50 100 150 200 250 METERS

3I 3S

34 Water-Resources Data and Hydrogeologic Setting for Research Stations in the Piedmont and Blue Ridge, 2000–2004
Figure 27. Generalized hydrogeologic cross section B–B’ along the well transect at the Langtree Peninsula research station, North 

Carolina (section location is shown in figure 25).

Open borehole

MW-6

cluster

MW-5

cluster

MW-4

cluster MW-1

cluster

Regolith

210.04 feet

Intermediate zone regolith

Bedrock

B B'

Vertical exaggeration = 1.6 times scale

Well casing Land surface

Screen

900

800

700

600

500

400

300

6IB 6D 6S

5D 5I 5S

4D

4IB 1S1D1I

0 100 200 300 400 FEET

0 20 40 60 80 100 METERS

Figure 27. Generalized hydrogeologic cross section B-B' along the well transect at the Langtree Peninsula research station, North Carolina

 (section location shown in fig. 25).

GP-3

ALTITUDE, IN FEET ABOVE NAVD 88

GP-1

4IA/4S

4S

4IA

Lake

Transition zone

Langtree Peninsula Research Station  35
Table 3. Construction characteristics of monitoring wells and the surface-water site at the Langtree Peninsula research station, North Carolina. 

[NAVD 88, North American Vertical Datum of 1988; MW, monitoring well; S, shallow; PVC, polyvinyl chloride casing; R, regolith; I, transition zone; D, deep; B, bedrock; GP, geoprobe; WL, water level; na, not applicable; SW, surface water]

Site 

identification

Station 

name

Construction 

date

Land-surface 

altitude 

(feet above 

NAVD 88)

Casing 

material

Casing 

diameter 

(inches)

Screened interval or open 

borehole interval (feet 

below land surface)

Screen 

type

Zone 

monitored

from to

353141080524701 MW–1S 10/17/2000 812.57 PVC 4.0 28 38 0.01 slotted PVC

R

353141080524702 MW–1I 10/11/2000 812.65 PVC 4.0 38 53 0.01 slotted PVC I

353141080524703 MW–1D 11/13/2000 812.51 PVC 4.0 76 602 Open hole

B

353135080524201 MW–2S 12/13/2000 803.08 PVC 4.0 13 28 0.01 slotted PVC

R

353135080524202 MW–2I 12/13/2000 802.89 PVC 4.0 33 48 0.01 slotted PVC I353135080524203 MW–2D 11/13/2000 802.69 PVC 6.0 53 400 Open hole

B

353157080525301 MW–3S 1/24/2001 761.96 PVC 4.0 5 15 0.01 slotted PVC

R

353157080525302 MW–3I 1/24/2001 762.92 PVC 4.0 43 73 0.01 slotted PVC I353157080525303 MW–3Da 1/23/2001 761.62 PVC 6.0 90 400 Open hole

B

353145080524702 MW–4Sb 3/27/2001 802.39 PVC 4.0 23 38 0.01 slotted PVC

R

353145080524701 MW–4I B 3/26/2001 802.93 PVC 4.0 38 53 0.01 slotted PVC

R

353145080524704 MW–4I A 2/26/2002 802.39 PVC 2.0 40 55 0.01 slotted PVC I

353145080524703 MW–4D 3/21/2001 801.84 PVC 4.0 69 400 Open hole

B

353148080524701 MW–5S 3/27/2001 786.18 PVC 4.0 10 20 0.01 slotted PVC

R

353148080524702 MW–5I 3/27/2001 785.07 PVC 4.0 20 35 0.01 slotted PVC I

353148080524703 MW–5D 3/13/2001 784.73 PVC 6.0 40 400 Open hole

B

353151080524601 MW–6S 3/28/2001 765.32 PVC 4.0 8 18 0.01 slotted PVC

R

353151080524602 MW–6Ic 4/2/2001 764.59 PVC 4.0 20 35 0.01 slotted PVC I

353151080524604 MW–6I B 3/4/2002 765.73 PVC 4.0 15 30 0.01 slotted PVC I

353151080524603 MW–6D 3/6/2001 765.84 PVC 4.0 69 400 Open hole

B

353144080524601 GEOPROBE (GP) 1 9/13/2000 805.10 PVC 0.5 29 39 0.01 slotted PVC

R

353148080524901 GEOPROBE (GP) 2 9/21/2000 793.48 PVC 0.5 27 36 0.01 slotted PVC

R

353146080524601 GEOPROBE (GP) 3 10/3/2000 791.04 PVC 0.5 22 31 0.01 slotted PVC

R

353145080524401 GEOPROBE (GP) 4 9/19/2000 793.08 PVC 0.5 25 34 0.01 slotted PVC

R

353149080524801 GEOPROBE (GP) 5 10/3/2000 786.81 PVC 0.5 23 32 0.01 slotted PVC

R

353150080524701 GEOPROBE (GP) 6 10/4/2000 776.58 PVC 0.5 16 25 0.01 slotted PVC

R

353151080524701 GEOPROBE (GP) 7 10/4/2000 767.37 PVC 0.5 9 18 0.01 slotted PVC

R

353151080524501 GEOPROBE (GP) 8 10/10/2000 768.04 PVC 0.5 8 18 0.01 slotted PVC

R

353147080524401 AUGER (WL) 1 10/10/2000 784.27 PVC 1.0 20 30 0.01 slotted PVC

R

353148080524601 AUGER (WL) 2 10/9/2000 780.74 PVC 1.0 16 26 0.01 slotted PVC

R

353150080524501 AUGER (WL) 3 10/10/2000 770.46 PVC 1.0 10 20 0.01 slotted PVC

R

353149080524401 AUGER (WL) 4 10/10/2000 775.85 PVC 1.0 17 26 0.01 slotted PVC

R

0214262175 Lake Norman 9/3/2002 762.18 na na na na na SW

aWell was abandoned in March 2002.bWell was drilled deeper in February 2002.cWell was abandoned in February 2002.

36  Water-Resources Data and Hydrogeologic Setting for Research Stations in the Piedmont and Blue Ridge, 2000–2004
Water-Resources Data

Borehole geophysical logs were collected from five 

bedrock wells at the LPRS (figs. 28–32). Data collected from 

these wells include caliper, natural gamma, short-normal and 

long-normal resistivity logs; fluid-temperature and fluidresistivity logs; heat-pulse flowmeter data (both ambient and 

stressed conditions); and OTV images (figs. 28–32). Bedrock 

well MW–3D was abandoned early in the study, and no 

geophysical logs were collected. 

Monthly water levels were measured in all 32 wells 

(including piezometers) as well as at the surface-water site at 

Lake Norman at the LPRS. Water levels have been measured 

in well cluster MW–1 since January 2001, in well clusters 

MW–2 and MW–3 since February 2001, and in well clusters 

MW–4, MW–5, and MW–6 since May 2001 (fig. 33). Periodic 

water levels have been recorded in the piezometers (table 3) 

from September 2000 through September 2004 (fig. 34). 

Periodic lake levels were plotted against the ground-water 

levels recorded in well clusters MW–3 and MW–6 (figs. 33C 

and 33F, respectively). Well MW–1S was dry from January 

2001 through June 2003, and well MW–5S was dry from 

January 2001 through March 2003 and January 2004 through 

September 2004. Regolith well MW–4S and transition-zone 

well MW–6I were discontinued in February 2002. Groundwater altitudes at well cluster MW–1 ranged from about 770 to 

780 ft in the shallow and transition zones and about 762 to 

770 ft in the bedrock zone. Ground-water altitudes at well 

cluster MW–2 ranged from about 777 to 788 ft in the shallow 

and transition zones and about 774 to 786 ft in the bedrock 

zone. Ground-water altitudes at well cluster MW–3 ranged 

from about 752 to 758 ft in all three zones. Ground-water 

altitudes at well cluster MW–4 ranged from about 765 to 

775 ft in the shallow and transition zones and about 753 to 

760 ft in the bedrock zone. Ground-water altitudes at well 

cluster MW–5 ranged from about 760 to 768 ft in the shallow 

and transition zones and about 752 to 760 ft in the bedrock 

zone. Ground-water altitudes at well cluster MW–6 ranged 

from about 752 to 758 ft in the shallow and transition zones 

and about 753 to 760 ft in the bedrock zone. The water-level 

altitudes in the bedrock zone were consistently lower than 

water-level altitudes in the shallow and transition zones at well 

clusters MW–1, MW–2, MW–4, and MW–5 (fig. 33). The 

water-level altitudes in the bedrock zone were consistently 

higher than water-level altitudes in the shallow and transition 

zones at well cluster MW–6 (fig. 33). Ground-water altitudes 

in the piezometers ranged from about 753 to 777 ft (fig. 34). 

Detailed summaries of ground-water-level data recorded in the 

LPRS wells for water years 2001–04 are published in USGS 

annual data reports for North Carolina (Howe and others, 

2002, 2003, 2004, and 2005).

Ground-water levels were recorded hourly in three 

wells in cluster MW–2 from March 2001 to September 2004 

(fig. 35). Ground-water levels in bedrock well MW–2D 

decreased substantially in November 2002 likely as a result 

of the pumping of nearby water-supply wells and an imprint 

pattern under the seasonal fluctuations observed in the cluster 

MW–2 wells. 

Ground-water altitude maps were constructed for the 

two water-level extremes for the LPRS for the study period of 

October 18, 2002, to September 23, 2003 (fig. 36). Maximum 

and minimum water levels measured in the shallow regolith 

wells, and a grid of piezometers were used to construct these 

ground-water altitude maps for the shallow system.

Slug tests were conducted in eight wells at the LPRS in 

May 2002 and November 2003. A 5-ft long, 3.5-inch diameter 

PVC bailer was used to displace water in the wells. The slug 

tests were conducted to estimate hydraulic conductivity in the 

three aquifer zones tapped by the wells—the shallow regolith, 

transition zone, and bedrock. The wells and intervals tested 

and the hydraulic conductivity values are given in table 4.

Table 4. Analytical results of slug tests in wells 

at the Langtree Peninsula research station, 

North Carolina.

Well 

number

Screened/Open 

interval 

(feet below 

land surface)

Hydraulic 

conductivity 

(feet per day)

Regolith wells

MW–2S 13–28 5

MW–3S 5–15 2

MW–6S 8–18 3

Transition-zone wells

MW–1I 38–53 0.6

MW–3I 43–73 2

Bedrock wells

MW–2D 53–400 0.4

MW–5D 40–400 7

MW–6D 69–400 2

Two sets of water-quality samples were collected from 

most of the wells (excluding the piezometers) and at 2-ft (top 

sample) and 12-ft (bottom sample) depths in Lake Norman, 

once in August 2002 and again in March 2003. Wells MW–1S 

and MW–5S were not sampled because of low water levels 

(dry), and only one transition-zone well (MW–4I) was 

sampled at well cluster MW–4. Results of the water-quality 

data collected are depicted in Piper diagrams (fig. 37) for all 

sampling dates and in Stiff diagrams (fig. 38) for March 2003. 

Major ion geochemistry in periodic ground-water samples 

from the shallow regolith and transition zone and in the lake 

samples is shown in figure 37A, and major ion geochemistry 

in ground-water samples from the open-hole bedrock wells 

at the LPRS is shown in figure 37B. Major ion geochemistry 

in ground-water-quality samples collected in March 2003 is 

Langtree Peninsula Research Station  37
Figure 28. Geophysical logs of bedrock well MW–1D at the Langtree Peninsula research station, North Carolina.

0 90

Fracture/Foliation

Dip angle (degrees)

DEPTH, IN FEET BELOW LAND SURFACEDEPTH, IN FEET BELOW LAND SURFACE

6 8

Caliper (inch)

Res (64N) (OHM-M)

1,000 4,000

Res (16N) (OHM-M)

1,000 4,000

Res (FL) (OHM-M)

63 66

0 2,000

-0.03 0.03

-1 1

Flow - ambient

Heat Pulse Flowmeter

(gal/min)

Flow - pumping

0

25

50

75

100

125

150

175

200

225

250

275

300

325

350

375

400

425

450

475

500

525

550

575

600

0

25

50

75

100

125

150

175

200

225

250

275

300

325

350

375

400

425

450

475

500

525

550

575

600

Optical Televiewer Image

0 0 90 180 270

GAM(NAT) (API-GR)

0 400

Temperature

(Degrees Fahrenheit)

Figure 28. Geophysical logs for bedrock well MW-1D at the Langtree Peninsula research station, North Carolina.

N E S W N

Ambient

inflow

Pumping

inflow

*Image obtained

in 6-inch

diameter well 

Note: No fracture/

foliation orientations

below 300 feet because

of magnetometer

problems

Note: pump was 

set at 60 feet 

N

S

EW

Example of tadpole

showing dip azimuth

Secondary fracture

Primary fracture

Foliation

Ambient

Pumping

EXPLANATION

Water level

38  Water-Resources Data and Hydrogeologic Setting for Research Stations in the Piedmont and Blue Ridge, 2000–2004
0 0 90 0 90 6 7  180 270

Caliper (inch)

GAM(NAT) (API-GR)

55 62

255 270

RES (FL) (OHM-M)

0 100

340

360

380

400

20

0

40

60

80

100

120

140

160

180

200

220

240

260

280

300

320

340

360

380

400

20

0

40

60

80

100

120

140

160

180

200

220

240

260

280

300

320

Fracture/Foliation

Dip angle (degrees)

Temperature

(Degrees Fahrenheit)

-0.12 0.12

-0.5 0.5

Flow - ambient

Flow - pumping

Heat Pulse Flowmeter

(gal/min)

N

S

EW

Example of tadpole

showing dip azimuth

Figure 29. Geophysical logs for bedrock well MW-2D at the Langtree Peninsula research station, North Carolina.

Optical Televiewer Image

N E S W N

Note: pump was 

set at 35 feet 

Camera

Line

Secondary fracture

Primary fracture

Foliation

Ambient

Pumping

EXPLANATION

Water level

DEPTH, IN FEET BELOW LAND SURFACEDEPTH, IN FEET BELOW LAND SURFACE

*Image obtained

in 6-inch

diameter well 

Water-bearing

fracture Pumping

inflow

Ambient

inflow

Ambient

outflow

Figure 29. Geophysical logs of bedrock well MW–2D at the Langtree Peninsula research station, North Carolina.

Langtree Peninsula Research Station  39
Figure 30. Geophysical logs of bedrock well MW–4D at the Langtree Peninsula research station, North Carolina.

Res (FL) (OHM-M)

0 0 10  0 90 0 90 6 7  180 270

Caliper (inch) 

GAM(NAT) (API-GR)

Res (64N) (OHM-M) 

0 4,000

Res (16N) (OHM-M) 

0 4,000

62 63

-0.5 0.5

-0.04 0.04

Flow - ambient

Flow - pumping

0 100

250

225

275

300

325

350

375

400

25

0

50

75

100

125

150

175

200

250

225

275

300

325

350

375

400

25

0

50

75

100

125

150

175

200

Optical Televiewer Image Fracture/Foliation

Dip angle (degrees) 

Temperature

(Degrees Fahrenheit) 

N

S

EW

Example of tadpole

showing dip azimuth

Heat Pulse Flowmeter

(gal/min)

Figure 30. Geophysical logs for bedrock well MW-4D at the Langtree Peninsula research station, North Carolina.

N E S W N

DEPTH, IN FEET BELOW LAND SURFACEDEPTH, IN FEET BELOW LAND SURFACE

*Image obtained

in 6-inch

diameter well 

Pumping

inflow

Ambient

inflow

Ambient

outflow

Pumping

inflow

Ambient

outflow

Ambient

inflow

Water-bearing

fractures

Water-bearing

fracture

Note: pump was 

set at 52 feet 

Camera

Line

Secondary fracture

Primary fracture

Foliation

Ambient

Pumping

EXPLANATION

Water level

40 Water-Resources Data and Hydrogeologic Setting for Research Stations in the Piedmont and Blue Ridge, 2000–2004
Figure 31. Geophysical logs of bedrock well MW–5D at the Langtree Peninsula research station, North Carolina.

Heat Pulse Flowmeter

(gal/min)

0 90 6 7.5 

Dip angle (degrees) Caliper (inch) Res (16N) (OHM-M)

0 4,000

Res (64N) (OHM-M)

0 4,000

0 150

RES (FL) (OHM-M)

-1.5 1.5

-0.04 0.04

Flow - ambient

Flow - pumping

250

225

275

300

325

350

375

400

25

50

75

100

125

150

175

200

250

225

275

300

325

350

375

400

25

50

75

100

125

150

175

200

N

S

EW

Example of tadpole

showing dip azimuth

Figure 31. Geophysical logs for bedrock well MW-5D at the Langtree Peninsula research station,

 North Carolina.

Optical Televiewer Image

0 50

Gamma Log (APIU)

0 0 90 180 270

N E S W N

Water-bearing

fractures

*Image obtained

in 6-inch

diameter well 

61 63

Temperature

(Degrees Fahrenheit) 

Note: pump was 

set at 31 feet 

Camera

Line

Secondary fracture

Primary fracture

Foliation

Ambient

Pumping

EXPLANATION

Water level

DEPTH, IN FEET BELOW LAND SURFACE

Pumping

inflow

Ambient

outflow

Pumping

inflow

Pumping

inflow

DEPTH, IN FEET BELOW LAND SURFACE

Langtree Peninsula Research Station 41
Figure 32. Geophysical logs of bedrock well MW–6D at the Langtree Peninsula research station, North Carolina.

0

10

20

30

40

50

60

70

80

90

100

110

120

130

140

150

160

170

180

190

200

210

220

230

240

250

260

270

280

290

300

310

320

330

340

350

360

370

380

390

400

0

10

20

30

40

50

60

70

80

90

100

110

120

130

140

150

160

170

180

190

200

210

220

230

240

250

260

270

280

290

300

310

320

330

340

350

360

370

380

390

400

-0.03 0.03

N

S

W E

Example of tadpole

showing dip azimuth

Optical Televiewer Image

0 600

Gamma Log (APIU)

0 0 90 180 270

N E S W N

0 90

Fracture/Foliation

Dip angle (degrees)

6 8

Caliper (inch)

Res (64N) (OHM-M)

0 4,000

Res (16N) (OHM-M)

0 4,000

Res (FL) (OHM-M)

62 66

Temperature

(Degrees Fahrenheit)

0 10 -1 1

Flow - ambient

Flow - pumping

Heat Pulse Flowmeter

(gal/min)

Figure 32. Geophysical logs for bedrock well MW-6D at the Langtree Peninsula research station, North Carolina.

DEPTH, IN FEET BELOW LAND SURFACEDEPTH, IN FEET BELOW LAND SURFACE

*Image obtained

in 6-inch

diameter well 

Water-bearing

fractures

Pumping

inflow

Pumping

inflow

Ambient

outflow

Note: pump was 

set at 25 feet 

Secondary fracture

Foliation

Ambient

Pumping

EXPLANATION

Water level

42 Water-Resources Data and Hydrogeologic Setting for Research Stations in the Piedmont and Blue Ridge, 2000–2004
Figure 33. Periodic ground-water levels recorded in well clusters (A) MW-1, (B) MW-2, (C) MW-3, (D) MW-4, (E) MW-5, and

(F) MW-6 at the Langtree Peninsula research station, North Carolina.

780

775

770

765

760

755

759

758

757

756

755

754

753

752

751

770

768

766

764

762

760

758

756

754

752

750

1/1 4/1

Water Year 

2001

Water Year 

2002

Water Year 

2003 Water Year

2004

7/1 10/1 1/1 4/1 7/1 10/1 1/1 4/1 7/1 10/1 1/1 4/1 7/1 10/1

A.

790

788

786

784

782

780

778

776

774

772

770

1/1 4/1

Water Year 

2001

Water Year 

2002

Water Year 

2003

Water Year 

2004

7/1 10/1 1/1 4/1 7/1 10/1 1/1 4/1 7/1 10/1 1/1 4/1 7/1 10/1

B.

1/1 4/1

Water Year 

2001

Water Year 

2002

Water Year 

2003

Water Year 

2004

7/1 10/1 1/1 4/1 7/1 10/1 1/1 4/1 7/1 10/1 1/1 4/1 7/1 10/1

C.

780

775

770

765

760

755

750

1/1 4/1

Water Year 

2001

Water Year 

2002

Water Year 

2003

Water Year 

2004

7/1 10/1 1/1 4/1 7/1 10/1 1/1 4/1 7/1 10/1 1/1 4/1 7/1 10/1

D.

1/1 4/1

Water Year 

2001

Water Year 

2002

Water Year 

2003

Water Year 

2004

7/1 10/1 1/1 4/1 7/1 10/1 1/1 4/1 7/1 10/1 1/1 4/1 7/1 10/1

E.

762

760

758

756

754

752

750

1/1 4/1

Water Year 

2001

Water Year 

2002

Water Year 

2003

Water Year 

2004

7/1 10/1 1/1 4/1 7/1 10/1 1/1 4/1 7/1 10/1 1/1 4/1 7/1 10/1

F.

WATER-LEVEL ALTITUDE, IN FEET ABOVE NAVD 88

MW-1S

MW-1I

MW-1D

MW-1D (without liner)

MW-2S

MW-2I

MW-2D

MW-3S

MW-3I

MW-3D

Lake

MW-4S

MW-4IA

MW-4IB

MW-4D

MW-4D (without liner)

MW-5S

MW-5I

MW-5D

MW-6S

MW-6I

MW-6IB

MW-6D

MW-6D (without liner)

Lake

Figure 33. Periodic ground-water levels recorded in well clusters (A) MW–1, (B) MW–2, (C) MW–3, (D) MW–4, (E) MW–5, and (F) MW–6 at 

the Langtree Peninsula research station, North Carolina.

Langtree Peninsula Research Station 43
Figure 34. Periodic ground-water levels recorded in piezometers at the Langtree Peninsula research station, North Carolina 

(GP, geoprobe; WL, auger).

780

775

770

765

760

755

750

WATER-LEVEL ALTITUDE, IN FEET ABOVE NAVD 88

SEPT. DEC.

2000 2001

MAR. JUNE SEPT. DEC.

2002

MAR. JUNE SEPT. DEC.

2003

MAR. JUNE SEPT. DEC. MAR. JUNE SEPT.

2004

Figure 34. Periodic ground-water levels recorded in all piezometers at the Langtree Peninsula research station,

North Carolina.

GP1

GP2

GP3

GP4

GP5

GP6

GP7

GP8

WL1

WL2

WL3

WL4

44 Water-Resources Data and Hydrogeologic Setting for Research Stations in the Piedmont and Blue Ridge, 2000–2004
Figure 35. Continuous hourly ground-water levels recorded in well cluster MW–2 at the Langtree Peninsula research station, North 

Carolina.

Langtree Peninsula Research Station 45

MW-2S

MW-2I

MW-2D

790

788

786

784

782

780

778

776

774

772

770

WATER-LEVEL ALTITUDE, IN FEET ABOVE NAVD 88

MAR. MAY

2001

JULY SEPT. NOV. MAR. MAY

2002

JULY SEPT. NOV. MAR. MAY

2003

JAN. JAN. JULY SEPT. NOV. MAR.JAN. MAY

2004

JULY SEPT.

Figure 35. Continuous hourly ground-water levels recorded in well cluster MW-2 at the Langtree Peninsula research station,

North Carolina.
Figure 36. Water-level altitudes measured in the shallow regolith at the Langtree Peninsula research station, North Carolina, for (A) September 23, 2003 (maximum), and 

(B) October 18, 2002 (minimum).

<774.57

<774.57

Lake

Norman

Langtree

Rd.

0 800 FEET 200 400 6000 200 METERS 50 100 150

Base from digital files ofU.S. Geological SurveyDigital Raster Graph, Lake Norman Quad1:24,000

MW-3S753.26

Lake

Norman

Langtree

Rd.

0 800 FEET 200 400 6000 200 METERS 50 100 150

800

810

800

800

800

790

790

790

780

770

780

780 760

770

800

810

800

790

790

780

770

780

780

770

Base from digital files ofU.S. Geological SurveyDigital Raster Graph, Lake Norman Quad1:24,000

Line of equal ground-water-level altitude, in feet above NAVD 88. Contour interval is 5 feet.  Dashed where approximateLine of land-surface elevation, in feet above NAVD 88. Contour interval is 10 feetGround-water-level altitude, in feet above NAVD 88Well and well number

345

EXPLANATION

350

GP-7753.45

MW-6S753.35

MW-5S

753.37

GP-4761.36 GP-1

GP-6753.65

GP-5 GP-2

759.03

GP-3761.95

753.81

WL-2759.03 WL-1

757.62

WL-4754.03

MW-1S

MW-2S778.03

MW-3S756.59

GP-7758.45

MW-6S757.20

MW-5S767.25

GP-8757.22

GP-4769.74 GP-1

776.83

GP-6758.20

GP-5761.33

GP-2765.61

Lake stage altitude 756.52 feet Lake stage altitude 753.33 feet

GP-3769.67

WL-3758.88

WL-2765.49

WL-1764.54

WL-4759.11

MW-1S

779.07

MW-2S788.82

755

760

765

765

775

770

770

775

780

765

760

758.93

GP-6

A. B.

N

N

780

770

790

780

770

Figure 36. General ground-water altitude maps in the shallow regolith at the Langtree Peninsula research station,North Carolina, for (A) September 23, 2003 (maximum) and (B) October 18, 2002 (minimum).

WL-3

GP-8

Unfinished roadGround-water level was below well depth altitude, in feet above NAVD 88

760

785

780

dry

<754.81

<766.10

800

800

46  Water-Resources Data and Hydrogeologic Setting for Research Stations in the Piedmont and Blue Ridge, 2000–2004
Figure 37. The water 

chemistry of samples 

from (A) regolith and 

transition-zone wells 

and the lake site, and 

(B) open-borehole 

bedrock wells at the 

Langtree Peninsula 

research station, 

North Carolina.

MW-1D

MW-2D

EXPLANATION

MW-2S

MW-3S

MW-6S

EXPLANATION 80

100

60

40

20

0

80

60

40

20

0

SULFATE PLUS CHLORIDE PLUS NITRATE

80

100

60

40

20

20

0

40

60

80

0 100 100

60 40 20

CALCIUM

CATIONS

100 80 0

20

40

60

80

100

20

40

60

80

0

20

40

60

80

MAGNESIUM

SODIUM PLUS POTASSIUM

40 60 80

CHLORIDE PLUS NITRATE

ANIONS

200 100

60 40 20

CALCIUM

CATIONS

100 80

B.

A.

0 40 60 80

CHLORIDE PLUS NITRATE

ANIONS

0 20 100

CARBONATE PLUS BICARBONATE

0 0

20

0

40

60

80

100 100

20

40

60

80

100

20

40

60

80

0

20

40

60

80

SODIUM PLUS POTASSIUM

CARBONATE PLUS BICARBONATE

80

100

60

40

20

0

SULFATE

80

100

60

40

20

0

MAGNESIUM

80

100

60

40

20

0

SULFATE

CALCIUM PLUS MAGNESIUM 

80

100

60

40

20

80

60

40

20 SULFATE PLUS CHLORIDE PLUS NITRATE

CALCIUM PLUS MAGNESIUM 

Figure 37. Piper diagrams showing the water chemistry of samples from the (A) regolith, and 

transition-zone wells and the lake site, and (B) open-borehole bedrock wells at the

Langtree Peninsula research station, North Carolina.

Lake Norman, 12-foot depth (bottom sample)

Lake Norman, 2-foot depth (top sample)

MW-1I

MW-3I

MW-4I

MW-5I

MW-6IB

3/5/03

3/5/03

3/5/03

3/5/03

3/5/03

3/3/03

3/3/03

3/4/03

3/4/03

8/26/02

8/26/02

8/27/02

8/28/02 8/28/02

8/24/02

8/28/02

3/4/03

6/15/04

Langtree Peninsula Research Station 47
Figure 38. Major ion milliequivalents in water samples collected from (A) regolith wells and the lake site, (B) transition-zone 

wells, and (C) open-borehole bedrock wells at the Langtree Peninsula research station, North Carolina, March 2003.

2 1 2 1

A.

2 1 21

B.

5 2.5 2.5 5

C.

Sodium

Lake Norman

2-foot depth

(top sample)

Lake Norman

12-foot depth

(bottom sample)

Calcium

Chloride

Bicarbonate

Magnesium Sulfate

Sodium

MW-1I

Calcium

Chloride

Bicarbonate

Magnesium Sulfate

Sodium

MW-1D

Calcium

Chloride

Bicarbonate

Magnesium Sulfate

Sodium

MW-2D

Calcium

Chloride

Bicarbonate

Magnesium Sulfate

Sodium

MW-3I

Calcium

Chloride

Bicarbonate

Magnesium Sulfate

Sodium

MW-4I

Calcium

Chloride

Bicarbonate

Magnesium Sulfate

Sodium

MW-5I

Calcium

Chloride

Bicarbonate

Magnesium Sulfate

Sodium

MW-6I

Calcium

Chloride

Bicarbonate

Magnesium Sulfate

Ammonia,

as Nitrogen

Ammonia,

as Nitrogen

Ammonia,

as Nitrogen

Ammonia,

as Nitrogen

Ammonia,

as Nitrogen

Ammonia,

as Nitrogen

Ammonia,

as Nitrogen

Ammonia,

as Nitrogen

Ammonia,

as Nitrogen

Ammonia,

as Nitrogen

Ammonia,

as Nitrogen

Ammonia,

as Nitrogen

Sodium

Calcium

Chloride

Bicarbonate

Magnesium Sulfate

Sodium

MW-2S

Calcium

Chloride

Bicarbonate

Magnesium Sulfate

Sodium

MW-3S

Calcium

Chloride

Bicarbonate

Magnesium Sulfate

Sodium

MW-6S

Calcium

Chloride

Bicarbonate

Magnesium Sulfate

Figure 38. Stiff diagrams showing major ion milliequivalents in water samples collected from (A) the regolith wells

and the lake site, (B) the transition-zone wells, and (C) the open-borehole bedrock wells at the Langtree Peninsula

research station, North Carolina, March 2003.

Nitrite plus Nitrate 

Nitrite plus Nitrate 

Nitrite plus Nitrate 

Nitrite plus Nitrate Nitrite plus Nitrate 

Nitrite plus Nitrate 

Nitrite plus Nitrate 

Nitrite plus Nitrate 

Nitrite plus Nitrate 

Nitrite plus Nitrate 

Nitrite plus Nitrate 

MILLIEQUIVALENTS PER LITER MILLIEQUIVALENTS PER LITER MILLIEQUIVALENTS PER LITER

Nitrite plus Nitrate 

48  Water-Resources Data and Hydrogeologic Setting for Research Stations in the Piedmont and Blue Ridge, 2000–2004
Figure 39. The range, median, and quartile statistical values for (A) pH, (B) specific 

conductance, and (C) dissolved oxygen for wells and the lake site during periodic 

sampling events at the Langtree Peninsula research station, North Carolina.

shown in figure 38. Ranges of water-quality-data results for all 

sampling dates are displayed in box plots (figs. 39–41).

Water-quality data (temperature, pH, SC, and DO 

concentrations) were collected at hourly intervals in two zones 

in well cluster MW–2 at the LPRS. Hourly data were collected 

in MW–2S (shallow regolith) from August 2002 to July 

2003 (fig. 42) and in MW–2D (bedrock) from August 2002 

to March 2004 (fig. 43). Water temperature at well cluster 

MW–2 ranged from about 16.2 to 16.8 °C in the shallow zone 

and from about 16 to 16.1 °C in the bedrock zone. Specific 

conductance ranged from about 30 to 80 μS/cm in the shallow 

zone and from about 85 to 95 μS/cm in the bedrock zone. 

The pH ranged from about 5.6 to 6.3 in the shallow zone and 

from about 6.5 to 7.5 in the bedrock zone. Dissolved-oxygen 

concentrations ranged from about 5.7 to 7.4 mg/L in the 

shallow zone and from about 5 to 6 mg/L in the bedrock zone.

BEDROCK

(3)

REGOLITH

(6)

TRANSITION

ZONE

(11)

LAKE

(2)

8.0

7.5

7.0

6.5

6.0

5.5

5.0

pH, IN STANDARD UNITS

300

250

200

150

100

50

0

SPECIFIC CONDUCTANCE, IN MICROSIEMENS PER

CENTIMETER AT 25 DEGREES CELSIUS

11

9

7

5

3

1

DISSOLVED OXYGEN, IN MILLIGRAMS

PER LITER

Upper detached

EXPLANATION

Lower detached

Upper adjacent

Lower adjacent

Median

75th percentile

25th percentile

Figure 39. The range, median, and quartile

statistical values for (A) pH, (B) specific

conductance, and (C) dissolved oxygen for

wells and the lake site during periodic sampling

events at the Langtree Peninsula research station,

North Carolina.

A.

B.

C.

(11) Number of samples

Interquartile range (IQR):

adjacent data are within

1.5 times the IQR, while

detached data are outliers.

Langtree Peninsula Research Station 49
Figure 40. The range, median, and quartile statistical values for (A) calcium, 

(B) magnesium, and (C) sodium for wells and the lake site during periodic 

sampling events at the Langtree Peninsula research station, North Carolina.

BEDROCK

(3)

REGOLITH

(6)

TRANSITION

ZONE

(11)

LAKE

(2)

25

20

15

10

5

0

CALCIUM, IN MILLIGRAMS PER LITER

4

3

2

1

0

MAGNESIUM, IN MILLIGRAMS PER LITER

10

8

6

4

2

0

SODIUM, IN MILLIGRAMS PER LITER

Upper detached

EXPLANATION

Lower detached

Upper adjacent

Lower adjacent

Median

75th percentile

25th percentile

Figure 40. The range, median, and quartile

statistical values for (A) calcium, (B) magnesium,

and (C) sodium for wells and the lake site during

periodic sampling events at the Langtree Peninsula

research station, North Carolina.

A.

B.

C.

(11) Number of samples

Interquartile range (IQR):

adjacent data are within

1.5 times the IQR, while

detached data are outliers.

50 Water-Resources Data and Hydrogeologic Setting for Research Stations in the Piedmont and Blue Ridge, 2000–2004
Figure 41. The range, median, and quartile statistical values for (A) bicarbonate, 

(B) chloride, and (C) sulfate for wells and the lake site during periodic sampling 

events at the Langtree Peninsula research station, North Carolina.

BEDROCK

(3)

REGOLITH

(6)

TRANSITION

ZONE

(11)

LAKE

(2)

100

80

60

40

20

0

BICARBONATE, IN MILLIGRAMS PER LITER

16

12

8

4

0

CHLORIDE, IN MILLIGRAMS PER LITER 

25

20

15

10

5

0

SULFATE, IN MILLIGRAMS PER LITER

Upper detached

EXPLANATION

Lower detached

Upper adjacent

Lower adjacent

Median

75th percentile

25th percentile

Figure 41. The range, median, and quartile

statistical values for (A) bicarbonate,

(B) chloride, and (C) sulfate for wells and the

lake site during periodic sampling events at the

Langtree Peninsula research station,

North Carolina.

A.

B.

C.

(11) Number of samples

Interquartile range (IQR):

adjacent data are within

1.5 times the IQR, while

detached data are outliers.

Langtree Peninsula Research Station  51
Figure 42. Hourly record of (A) temperature, (B) pH, (C) specific conductance, and (D) dissolved oxygen in well MW–2S in the shallow 

regolith at the Langtree Peninsula research station, North Carolina.

2002 WATER YEAR 2003 WATER YEAR

AUGUST SEPTEMBER OCTOBER NOVEMBER DECEMBER JANUARY FEBRUARY MARCH APRIL MAY JUNE JULY

9.0

8.5

8.0

7.5

7.0

6.5

6.0

5.5

5.0

4.5

4.0

DISSOLVED OXYGEN, IN

MILLIGRAMS PER LITER

120

100

80

60

40

20

0

17.0

16.8

16.6

16.4

16.2

16.0

WATER TEMPERATURE,

IN DEGREES CELSIUS

7.0

6.8

6.6

6.4

6.2

6.0

5.8

5.6

5.4

5.2

5.0

pH

A.

B.

C.

D.

Figure 42. Hourly record of (A) temperature, (B) pH, (C) specific conductance, and (D) dissolved oxygen in well MW-2S in the 

shallow regolith at the Langtree Peninsula research station, North Carolina.

SPECIFIC CONDUCTANCE,

IN MICROSIEMENS PER

CENTIMETER AT

25 DEGREES CELSIUS

52 Water-Resources Data and Hydrogeologic Setting for Research Stations in the Piedmont and Blue Ridge, 2000–2004
Figure 43. Hourly record of (A) temperature, (B) pH, (C) specific conductance, and (D) dissolved oxygen in well MW–2D in bedrock at the 

Langtree Peninsula research station, North Carolina.

2002 WATER YEAR 2003 WATER YEAR 2004 WATER YEAR

AUG. SEPT. OCT. NOV. DEC. JAN. FEB. MAR. APR. MAY JUNE JULY AUG. SEPT. OCT. NOV. DEC. JAN. FEB. MAR.

8

7

6

5

4

3

DISSOLVED OXYGEN,

2

IN MILLIGRAMS 

PER LITER

120

110

100

90

80

70

16.3

16.2

16.1

16.0

15.9

15.8

WATER TEMPERATURE,

IN DEGREES CELSIUS

10.0

9.0

8.0

7.0

6.0

5.0

pH

A.

B.

C.

D.

Figure 43. Hourly record of (A) temperature, (B) pH, (C) specific conductance, and (D) dissolved oxygen in well MW-2D in

bedrock at the Langtree Peninsula research station, North Carolina.

SPECIFIC CONDUCTANCE,

IN MICROSIEMENS PER

CENTIMETER AT

25 DEGREES CELSIUS

Langtree Peninsula Research Station  53
Upper Piedmont Research Station

Site Description and Geology

The Upper Piedmont research station in Rockingham 

County is the first hydrogeologic research station installed 

in the DWQ Winston-Salem Region of North Carolina as 

part of the PMREP (fig. 44). The UPRS is an agricultural 

research farm owned and operated by North Carolina State 

University and the North Carolina Department of Agriculture. 

The research station is adjacent to a 4–H educational center, 

and together the properties form an approximately 850-acre 

tract of State-owned land. The hydrogeologic research station 

occupies parts of both properties (figs. 45, 46). The study 

area, which is in the upper Wolf Island Creek watershed, 

encompasses approximately 150 acres about 2 miles northwest 

of the center of Reidsville, NC. 

The UPRS lies in the Milton litho-tectonic belt in the 

western Piedmont Physiographic Province (fig. 44). The 

Milton Belt consists of heterogeneous gneisses and schists 

of metasedimentary and metaigneous origin. The geology 

of the study area consists of gently to moderately dipping 

amphibolite and interlayered felsic gneiss and amphibolite 

rock types. Regionally, the UPRS is located within the felsic 

gneiss (GNF) and mafic gneiss (GNM) hydrogeologic units 

(fig. 44). Felsic gneisses represent about 20 to 30 percent of 

the hydrogeologic settings in the Piedmont and Blue Ridge 

Provinces of North Carolina, whereas mafic gneisses represent 

about 18 percent (Daniel and Dahlen, 2002). The UPRS 

consists of two well-cluster transects, the northern (A–A') 

and southern (B–B'). Based on detailed geologic mapping 

by Horton and Geddes (in press) and geologic coring, 

the northern transect well clusters are located in areas of 

interlayered mica gneiss and schist, felsic gneiss, amphibolite, 

and mylonitic mica schist and gneiss; the southern transect 

well clusters are located in areas of felsic gneiss and 

amphibolite. Work that was conducted from March 2002 to 

September 2004 at the UPRS included the detailed geologic 

mapping and structural analysis of the upper Wolf Island 

Creek drainage basin (Horton and Geddes, in press), collection 

and logging of nine soil and rock cores totaling 1,100 ft of 

sample, installation of 19 observation wells grouped into 

seven clusters aligned along two transects, installation of 

14 piezometers for water-level and aquifer-test monitoring, 

installation of a real-time DCP for monitoring of water levels 

and water quality in a three-well cluster and in adjacent Wolf 

Island Creek, monthly collection of water levels, sampling 

of wells, a 48-hour aquifer test, slug tests, and borehole 

geophysical logs.

An interesting aspect of the UPRS is the local groundwater-flow system. The well transects were located to test the 

hypothesis of the control of the local geology (rock structure) 

on ground-water flow. The geologic structure dips consistently 

to the south and southeast across the study area. Land surface 

in the northern part of the study area slopes steeply toward 

the north (opposite the dip direction (cut slope)), while land 

surface in the southern part slopes gently toward the south (in 

the same direction as dip (dip slope)), permitting a comparison 

of dip-slope to cut-slope hydrogeologic settings. One transect 

of well clusters was installed down each slope (dip slope and 

cut slope) with the intent of studying differences in groundwater flow between the two transects (figs. 47, 48). The 

conceptual model of the site includes a relatively short flow 

path down the dip slope and a relatively longer (or torturous) 

flow path down the cut slope. 

Well Construction

Seven ground-water monitoring-well clusters that 

include two to four wells each as well as 14 piezometers 

were constructed (figs. 45, 46). All of the piezometers were 

installed near the northern transect. Well-cluster locations 

were selected to obtain water-quality and water-level data 

along two transects encompassing areas of recharge and 

discharge based on conceptual models developed for the slopeaquifer system (LeGrand and Nelson, 2004). Criteria for well 

locations included topographic setting, accessibility, and site 

boundaries. During this study, a total of 33 wells (including 

piezometers) were installed at the UPRS (table 5). Cross 

section A–A' was constructed along the northern transect from 

well cluster MW–N1 generally south along the cut slope to 

well cluster MW–N4 (fig. 47), and cross section B–B' was 

constructed along the southern transect from well cluster 

MW–S1 generally southeast along the dip slope to well cluster 

MW–S4 (fig. 48). Well clusters MW–N4 and MW–S1 are 

located in conceptual recharge areas, and well clusters 

MW–N1 and MW–S4 are located in discharge areas near 

streams. The 14 piezometers were installed to provide 

data during aquifer tests and for hydrogeologic site 

characterization. Six of the piezometers were installed in 

clusters of two (three clusters), each containing a shallow and 

transition-zone piezometer.

Each well cluster at the UPRS consists of two to four 

wells—a shallow water-level well to monitor ground-water 

conditions in the regolith, a transition zone well to monitor 

conditions in the partially weathered bedrock and open 

fractures near the top of bedrock, and a deeper bedrock well 

to monitor ground water in the fractured bedrock aquifer 

(figs. 47, 48). Well-construction information is provided in 

table 5. Well cluster MW–S3 contains an additional transitionzone well. Well clusters MW–N4, MW–N3, and MW–S1 do 

not contain regolith wells. Well clusters MW–N2, MW–N4, 

and MW–S4 (figs. 47, 48) each contain a well completed 

in the transition zone to monitor conditions in the partially 

weathered bedrock and open fractures in the upper part of the 

bedrock.

54 Water-Resources Data and Hydrogeologic Setting for Research Stations in the Piedmont and Blue Ridge, 2000–2004
Figure 44. Locations of Upper Piedmont research station, hydrogeologic units in Rockingham County, and geologic belts delineated in 

North Carolina (modified from North Carolina Geological Survey, 1985; Daniel and Payne, 1990).

Base from digital files of:

U.S. Department of Commerce, Bureau of Census,

 1990 Precensus TIGER/Line Files-Political boundaries, 1991

U.S. Environmental Protection Agency, River File 3

U.S. Geological Survey, 1:100,000 scale 

Upper Piedmont research station

HYDROGEOLOGIC UNITS

 (Daniel and Payne, 1990)

Gneiss, felsic (GNF)

Gneiss, mafic (GNM)

Igneous, felsic intrusive (IFI)

Metaigneous, felsic (MVF)

Metavolcanic, mafic (MVM)

Schist (SCH)

Triassic sedimentary rocks (TRI)

Northern

transect

Southern

transect

Figure 44. Locations of Upper Piedmont research station, hydrogeologic units in Rockingham County, and geologic belts delineated 

in North Carolina (modified from NCGS, 1985; Daniel and Payne, 1990).

0 5 10 MILES

0 8 16 KILOMETERS

Murphy Belt

Blue

Ridge

Belt

Chauga

Belt

Inner

Piedmont

Belt

Charlotte

Belt

Belt

Subbasin

Tr-DCB

Kings

Mtn.

Gold Hill

shear zone

CS

Milton

Belt

Sauratown Mtn.

ant.

SR

Tr-DRB

Sauratown Mtn. ant.

SR

Tr-DCB

Tr-DRB

CS

CP

Sauratown Mountains anticlinorium

Smith River allochthon

Davie County Triassic basin

Dan River Triassic basin

Carolina Slate Belt

Western margin of Coastal Plain Physiographic Province

Boundary between Blue Ridge and Piedmont

 Physiographic Provinces

Thrust fault with teeth on upthrown block

Piedmont Coastal Plain

Blue Ridge

CP

34

35

36

84 83 82 81 80 79 78 77 76

Tr-Wadesboro

CS

Brevard fault zone

CP

CP

Rockingham

Co.

Reidsville

TENNESSEE

VIRGINIA

SOUTH CAROLINA

GEORGIA

EXPLANATION

Carolina

Slate

Belt

Eastern

Slate

Belt

Raleigh

Sanford

-Durham

0 25 50 75 100 MILES

0 25 50 75 100 KILOMETERS

Atlantic

Ocean

N EXPLANATION

GNM

GNM

GNM

GNM

GNF

GNF

GNF

GNF

GNF

IFI

IFI

IFI

MVF

MVM

SCH

TRI

TRI

TRI SCH

SCH

SCH

IFI

IFI

GNF

Upper Piedmont Research Station  55
Figure 45. Aerial photograph overlaid with topographic features showing locations of well clusters, surface-water site, 

and line of section A–A’ along the northern transect at the Upper Piedmont research station in Rockingham County, North 

Carolina.

Figure 45. Aerial photograph overlaid with topographic features, showing

locations of well clusters and line of section A-A’ along the northern transect

at the Upper Piedmont research station in Rockingham County, North Carolina.

A A'

EXPLANATION

Cross section

Altitude of land surface above

 NAVD 88. Contour

 interval 20 feet

Well cluster and number

Piezometer and number

Surface-water sampling site

800

800

780

760

820

840

740

720

680

680

700

700

MW-N4

cluster

MW-N2

cluster

MW-N1

cluster

N

A

A’

0 200 400 FEET

0 50 100 METERS

Base from:

1998 photograph from Rockingham County, 

North Carolina GIS database contours 1993 

USGS topographic sheet, Southeast Eden Quadrangle, 1:24,000 scale

700

PZ-1

PZ-2 PZ-3

PZ-4

MW-N2

PZ-1

Carrol

Creek

56  Water-Resources Data and Hydrogeologic Setting for Research Stations in the Piedmont and Blue Ridge, 2000–2004
Figure 46. Aerial photograph overlaid with topographic features showing locations of well clusters, streamgaging station, 

and line of section B–B’ along the southern transect at the Upper Piedmont research station in Rockingham County, North 

Carolina.

Figure 46. Aerial photograph overlaid with topographic features showing

locations of well clusters, streamgaging station and line of section B-B’ along

the southern transect at the Upper Piedmont research station in Rockingham

County, North Carolina.

800

820

780

760

760

780

740

740

720

720

700

700

700

680

660

660

680

700

680

N

B'

B

0 400 800 FEET

0 100 200 METERS

B B'

EXPLANATION

Cross section

Altitude of land surface above

 NAVD 88. Contour interval 

 20 feet

Well cluster and number

USGS streamgaging station

800

Base from:

1998 photograph from Rockingham County, 

North Carolina GIS database contours 1993 

USGS topographic sheet, Southeast Eden Quadrangle, 1:24,000 scale

MW-S4

Wolf

Island

Cr.

MW-S1

cluster

MW-S3

cluster

MW-S4

cluster

Upper Piedmont Research Station  57
Figure 47. Generalized hydrogeologic cross section A–A’ along the northern well transect at the Upper Piedmont research station, North 

Carolina (section location is shown in figure 45; bedrock lithologies from Horton and Geddes, in press).

Felsic Gneiss

Mylonitic Mica Schist

and Gneiss

Mica Gneiss 

and

Schist

Carrol

Creek 1S 1I 1D

MW-N1

cluster

2S 2I

MW-N2

cluster

3I3D

MW-N3

cluster

4I4D

MW-N4

cluster

900

800

700

600

500

400

300

Figure 47 . Generalized hydrgeologic cross section A - A’ along the northern well transect at the Upper Piedmont research station,

North Carolina (Bedrock lithologies from Horton and Geddes, in press).

Open

borehole

A

A'

0 100 200 300 400 FEET Vertical exaggeration = 2.3 times scale

0 20 40 60 80 100 METERS

Foliation

ALTITUDE, IN FEET ABOVE NAVD 88

Well casing

Screen

2D

Land surface 

Regolith

Transition zone

Amphibolite

58  Water-Resources Data and Hydrogeologic Setting for Research Stations in the Piedmont and Blue Ridge, 2000–2004
Figure 48. Generalized hydrogeologic cross section B–B’ along the southern well transect at the Upper Piedmont research station, North 

Carolina (section location is shown in figure 46; bedrock lithologies from Horton and Geddes, in press).

900

800

700

600

500

400

300

200

Figure 48 . Generalized hydrgeologic cross section B - B’ along the southern well transect at the Upper Piedmont research station,

North Carolina (Bedrock lithologies from Horton and Geddes, in press).

Open

borehole

Screen

Well

casing

B

B'

0 100 200 300 400 FEET

0 20 40 60 80 100 METERS

Data collection 

platform (DCP) 

Vertical exaggeration =

2.8 times scale

Wolf

Island

Creek

Regolith

Transition zone

1I1D

MW-S1

cluster

3UI 3S3D3LI

MW-S3

cluster

4D4I4S

MW-S4

cluster

ALTITUDE, IN FEET ABOVE NAVD 88

Land surface 

Foliation

Felsic Gneiss

Amphibolite

Amphibolite

Upper Piedmont Research Station  59
Table 5. Construction characteristics of monitoring wells and the surface-water site at the Upper Piedmont research station, North Carolina. 

[NAVD 88, North American Vertical Datum of 1988; MW, monitoring well; S, shallow; PVC, polyvinyl chloride casing; R, regolith; I or T, transition zone; D, deep; GS, galvanized steel; B, bedrock; PZ, piezometer; na, not applicable; SW, surface water]

Site 

identification

Station 

name

Construction 

date

Land-surface 

altitude 

(feet above 

NAVD 88)

Casing 

material

Casing 

diameter 

(inches)

Screened interval or 

open borehole interval 

(feet below land 

surface)

Screen 

type

Zone 

monitored

from to

362334079421601 MW-N1S 4/9/2002 672.76 PVC 4.0 5 15 0.01 slotted PVC

R

362334079421602 MW-N1I 5/14/2002 672.27 PVC 4.0 50 65 0.01 slotted PVC I

362334079421603 MW-N1D 5/14/2002 672.51 GS 6.0 100 300 Open hole

B

362331079421601 MW-N2S 4/9/2002 672.48 PVC 4.0 3 13 0.01 slotted PVC

R

362331079421602 MW-N2I 5/21/2002 671.56 PVC 6.0 25 50 Open hole

T

362331079421603 MW-N2D 5/20/2002 671.91 GS 6.0 60 300 Open hole

B

362328079421701 MW-N3I 6/12/2002 770.44 PVC 4.0 15 30 0.01 slotted PVC I

362328079421702 MW-N3D 6/12/2002 770.26 GS 6.0 40 260 Open hole

B

362323079421201 MW-N4I 5/22/2002 839.63 PVC 6.0 44 70 Open hole

T

362323079421202 MW-N4D 5/29/2002 840.19 GS 6.0 80 300 Open hole

B

362240079411801 MW-S1I 5/1/2002 803.34 PVC 4.0 35 50 0.01 slotted PVC I

362240079411802 MW-S1D 5/1/2002 802.55 GS 6.0 61.5 301 Open hole

B

362231079410801 MW-S3S 4/10/2002 705.16 PVC 4.0 23 38 0.01 slotted PVC

R

362231079410802 MW-S3UI 4/24/2002 705.60 PVC 4.0 45 55 0.01 slotted PVC I

362231079310803 MW-S3LI 4/23/2002 705.60 PVC 4.0 63 73 0.01 slotted PVC I

362231079310804 MW-S3D 4/4/2002 705.48 GS 6.0 87.5 438 Open hole

B

362226079410101 MW-S4S 4/9/2002 659.50 PVC 4.0 5 15 0.01 slotted PVC

R

362226079410102 MW-S4I 3/26/2002 659.32 GS 6.0 25 35 Open hole

T

362226079410103 MW-S4D 3/25/2002 659.57 GS 6.0 77 380 Open hole

B

362335079421701 PZ-1 4/16/2003 675.95 PVC 2.0 40 50 0.01 slotted PVC

R

362334079421701 PZ-2 4/29/2003 673.02 PVC 2.0 14 24 0.01 slotted PVC

R

362334079421703 PZ-3 4/24/2003 672.17 PVC 2.0 29 39 0.01 slotted PVC

R

362334079421704 PZ-4 4/21/2003 672.25 PVC 2.0 21 31 0.01 slotted PVC

R

362332079421601 PZ-5 4/23/2003 671.62 PVC 2.0 16 26 0.01 slotted PVC

R

362332079421602 PZ-5I 8/12/2003 671.79 PVC 2.0 30 40 0.01 slotted PVC

R

362332079421603 PZ-5D 8/5/2003 671.72 PVC 2.0 70 90 0.01 slotted PVC

R

362331079421701 PZ-6 4/23/2003 672.91 PVC 2.0 8 13 0.01 slotted PVC

R

362331079421702 PZ-6I 8/13/2003 673.02 PVC 2.0 30 40 0.01 slotted PVC

R

362331079421703 PZ-6D 7/22/2003 673.04 PVC 2.0 70 90 0.01 slotted PVC

R

362332079421604 PZ-7 4/22/2003 671.43 PVC 2.0 14 19 0.01 slotted PVC

R

362331079421501 PZ-7I 8/13/2003 671.28 PVC 2.0 30 40 0.01 slotted PVC

R

362331079421502 PZ-7D 7/28/2003 671.48 PVC 2.0 75 95 0.01 slotted PVC

R

362332079421605 PZ-8 4/22/2003 672.21 PVC 2.0 14 24 0.01 slotted PVC

R

0207428225 Wolf Island Creek 12/23/2002 650 na na na na na SW

60 Water-Resources Data and Hydrogeologic Setting for Research Stations in the Piedmont and Blue Ridge, 2000–2004
Water-Resources Data

Borehole geophysical logs were collected from seven 

bedrock wells at the UPRS. Data collected from these wells 

include caliper, natural gamma, short-normal resistivity, and 

long-normal resistivity logs; fluid-temperature and fluidresistivity logs; heat-pulse flowmeter data (both ambient and 

stressed conditions); and OTV images (figs. 49–55). 

Monthly water levels were measured in all 33 wells at 

the UPRS. Water-level measurements have been recorded 

in well clusters MW–N1, MW–N2, MW–S1, MW–S3, and 

MW–S4 since May 2002, in well MW–N4 since June 2002, 

in well MW–N3 since August 2002 (figs. 56, 57), and in the 

piezometers since June 2003 (fig. 58). The period of record 

presented in this report is from May 2002 through September 

2004. Ground-water altitudes in well cluster MW–N1 for the 

bedrock zone (668 to 672 ft) were consistently higher than 

water-level altitudes in the regolith and transition zone (665 to 

667 ft). Water-level altitudes at well cluster MW–N2 in the 

regolith (665 to 672 ft) were consistently higher than waterlevel altitudes in the transition and bedrock zones (664 to 

668 ft). Ground-water altitudes at well cluster MW–N3 ranged 

from about 742 to 746 ft in the transition zone and about 

702 to 708 ft in the bedrock zone. Ground-water altitudes 

at well cluster MW–N4 ranged from about 802 to 815 ft in 

the transition zone and about 796 to 808 ft in the bedrock 

zone. The water-level altitudes in the transition zone were 

consistently higher than water-level altitudes in the bedrock 

zone at well clusters MW–N3 and MW–N4. Ground-water 

altitudes at well cluster MW–S1 ranged from about 772 to 

791 ft in the transition zone and about 778 to 791 ft in the 

bedrock zone. Ground-water altitudes at well cluster MW–S3 

ranged from about 678 to 685 ft in the regolith and transition 

zone and about 679 to 686 ft in the bedrock zone. Groundwater altitudes at well cluster MW–S4 ranged from about 

654 to 656 ft in all three zones. The water-level altitudes in 

the bedrock zone were consistently higher than water-level 

altitudes in the regolith and transition zone at well clusters 

MW–S1, MW–S3, and MW–S4. The water-level altitudes for 

the regolith were consistently higher than water-level altitudes 

in the transition zone at piezometer clusters PZ–5, PZ–6, and 

PZ–7. Ground-water altitudes in the piezometers ranged from 

about 666 to 671 ft. –Detailed summaries of ground-waterlevel data recorded in the UPRS wells for water years 2002–04 

are published in USGS annual data reports for North Carolina 

(Howe and others, 2003, 2004, 2005). 

Continuous ground-water levels were recorded in four 

wells, and stage was recorded in a nearby stream (Wolf Island 

Creek, station 0207428225) at the UPRS. Ground-water levels 

were recorded hourly in all three wells in well cluster MW–S4 

from May 2003 to October 2004 (fig. 59) and in bedrock well 

MW–S3D from November 2003 to March 2004 (fig. 60). 

Stage in Wolf Island Creek was recorded at 15-minute 

intervals from May 2003 to September 2004, and continuous 

stage was plotted hourly for comparison to well cluster 

MW–S4 (fig. 59). 

Slug tests were conducted in six wells at the UPRS 

during September 2002. A 5-ft long, 3.5-inch diameter PVC 

bailer was used to displace water in the wells. The slug tests 

were conducted to obtain estimates of hydraulic conductivity 

for the three aquifer zones tapped by the wells—the regolith, 

transition zone, and bedrock. The estimates obtained are 

representative of conditions in the immediate vicinity of the 

tested wells. The wells and intervals tested and the hydraulic 

conductivity values are given in table 6.

Table 6. Analytical results of slug tests in 

wells at the Upper Piedmont research station, 

North Carolina.

Well 

number

Screened/Open 

interval 

(feet below 

land surface)

Hydraulic 

conductivity 

(feet per day)

Regolith wells

MW-S4S 5–15 4

Transition-zone wells

MW-N2I 25–50 8

MW-S3LI 63–73 3

MW-S4I 25–35 10

Bedrock wells

MW-N2D 60–300 0.4

MW-S3D 87.5–438 0.8

Water-quality samples were collected from all wells, with 

the exception of the piezometers, and from Wolf Island Creek 

and Carrol Creek at the UPRS (figs. 45, 46). To date (2006), 

water-quality samples have been collected twice—once in 

December 2002 and again during February through April 

2004. During the second sampling event (February–April 

2004) the multifunction BAT3 (Shapiro, 2001) inflatable 

packer system was used in the bedrock wells to isolate fracture 

zones. Major ion geochemistry in periodic water-quality 

samples from the regolith, transition zone, and in surfacewater samples is shown in figure 61A; major ion geochemistry 

in periodic water-quality samples from the open bore-hole 

bedrock wells at the UPRS is shown in figure 61B. Major ion 

geochemistry in water-quality samples collected in December 

2002 at the UPRS is shown in figure 62. Ranges in values of 

major ion geochemistry and physical properties are shown in 

box plots in figures 63–65.

Continuous real-time water-quality properties were 

monitored in all three ground-water zones in well cluster 

MW–S4 and in Wolf Island Creek. Hourly data from 

MW–S4S (shallow regolith), MW–S4I (transition zone), 

and MW–S4D (bedrock) were collected from June 2003 

through September 2004 (figs. 66–68). Fifteen-minute data 

were collected in Wolf Island Creek from June 2003 through 

September 2004 (fig. 69). The water-quality data collected 

Upper Piedmont Research Station  61
Figure 49. Geophysical logs of bedrock well MW–N1D at the Upper Piedmont research station, North Carolina.

0

10

20

30

40

50

60

70

80

90

100

110

120

130

140

150

160

170

180

190

200

210

220

230

240

250

260

270

280

290

300

N

S

EW

Example of tadpole

showing dip azimuth

Secondary fracture

Primary fracture

Foliation

EXPLANATION

-0.03 0.03

Flow - ambient

Heat Pulse Flowmeter

(gal/min)

Optical Televiewer Image

0 600

Gamma Log (APIU)

0 90 180 270 0

N E S W N

0 90

Fracture/Foliation

Dip angle (degrees)

6 8

Caliper (inch)

Res (64N) (OHM-M)

1,000 4,000

Res (16N) (OHM-M)

1,000 4,000

Res (FL) (OHM-M)

51 57

Temperature

(Degrees Fahrenheit)

0 10

Figure 49. Geophysical logs for bedrock well MW-N1D at the Upper Piedmont research station, North Carolina.

Camera

Lines

Ambient

DEPTH, IN FEET BELOW LAND SURFACE

0

10

20

30

40

50

60

70

80

90

100

110

120

130

140

150

160

170

180

190

200

210

220

230

240

250

260

270

280

290

300

DEPTH, IN FEET BELOW LAND SURFACE

*Image obtained

in 6-inch

diameter well 

Note: pump was 

set at 65 feet 

Water level

Ambient

inflow

Ambient

outflow

62 Water-Resources Data and Hydrogeologic Setting for Research Stations in the Piedmont and Blue Ridge, 2000–2004
Figure 50. Geophysical logs of bedrock well MW–N2D at the Upper Piedmont research station, North Carolina.

0

10

20

30

40

50

60

70

80

90

100

110

120

130

140

150

160

170

180

190

200

210

220

230

240

250

260

270

280

290

300

N

S

EW

Example of tadpole

showing dip azimuth

-0.02 0.02

-1.5 1.5

Flow - ambient

Flow - pumping

Heat Pulse Flowmeter

(gal/min)

Optical Televiewer Image

0 700

Gamma Log (APIU)

0 90 180 270 0

N E S W N

0 90

Fracture/Foliation

Dip angle (degrees)

6 8

Caliper (inch)

Res (64N) (OHM-M)

0 4,000

Res (16N) (OHM-M)

0 4,000

Res (FL) (OHM-M)

60 64

Temperature

(Degrees Fahrenheit)

50 55

DEPTH, IN FEET BELOW LAND SURFACE

10

0

20

30

40

50

60

70

80

90

100

110

120

130

140

150

160

170

180

190

200

210

220

230

240

250

260

270

280

290

300

DEPTH, IN FEET BELOW LAND SURFACE

*Image obtained

in 6-inch

diameter well 

Note: pump was 

set at 40 feet 

Figure 50. Geophysical logs for bedrock well MW-N2D at the Upper Piedmont research station, North Carolina.

Camera

Line

Secondary fracture

Foliation

Ambient

Pumping

EXPLANATION

Water level

Pumping

inflow

Upper Piedmont Research Station  63
Figure 51. Geophysical logs of bedrock well MW–N3D at the Upper Piedmont research station, North Carolina.

0

10

20

30

40

50

60

70

80

90

100

110

120

130

140

150

160

170

180

190

200

210

220

230

240

250

260

0 90

Fracture/Foliation

Dip angle (degrees) 

N

S

EW

Example of tadpole 

showing dip azimuth 

-0.01 0.01

-1 1

Flow - ambient 

Flow - pumping Optical T eleviewer Image 

0 500

Gamma Log (APIU) 

0 90 180 270 0

N E S W N

6 9

Caliper (inch) 

Res (64N) (OHM-M) 

0 4,000

Res (16N) (OHM-M) 

0 3,000

Res (FL) (OHM-M) 

59 64

Temperature

(Degrees Fahrenheit) 

60 63

Heat Pulse Flowmeter

(gal/min)

Figure 51. Geophysical logs for bedrock well MW-N3D at the Upper Piedmont research station, North Carolina.

Water-bearing

fracture

Note: pump was 

set at 85 feet 

Secondary fracture

Foliation

Ambient

Pumping

EXPLANATION

Water level

DEPTH, IN FEET BELOW LAND SURFACE

0

10

20

30

40

50

60

70

80

90

100

110

120

130

140

150

160

170

180

190

200

210

220

230

240

250

260

DEPTH, IN FEET BELOW LAND SURFACE

*Image obtained

in 6-inch

diameter well 

Camera

Lines

Pumping

inflow

Pumping

inflow

64 Water-Resources Data and Hydrogeologic Setting for Research Stations in the Piedmont and Blue Ridge, 2000–2004
Figure 52. Geophysical logs of bedrock well MW–N4D at the Upper Piedmont research station, North Carolina.

0

10

20

30

40

50

60

70

80

90

100

110

120

130

140

150

160

170

180

190

200

210

220

230

240

250

260

270

280

290

300

0

10

20

30

40

50

60

70

80

90

100

110

120

130

140

150

160

170

180

190

200

210

220

230

240

250

260

270

280

290

300

N

S

EW

Example of tadpole 

showing dip azimuth 

-0.03 0.03

-0.1 0.1

Flow - ambient 

Flow - pumping (recovery) Optical T eleviewer Image 

0 1,000

Gamma Log (APIU) 

0 90 180 270 0

N E S W N

0 90

Fracture/Foliation

Dip angle (degrees) 

6 7

Caliper (inch) 

Res (64N) (OHM-M) 

0 4,000

Res (16N) (OHM-M) 

0 3,000

Res (FL) (OHM-M) 

61 64

Temperature

(Degrees Fahrenheit) 

60 70

Heat Pulse Flowmeter

(gal/min)

Camera

Lines

Figure 52. Geophysical logs for bedrock well MW-N4D at the Upper Piedmont research station, North Carolina.

DEPTH, IN FEET BELOW LAND SURFACEDEPTH, IN FEET BELOW LAND SURFACE

*Image obtained

in 6-inch

diameter well 

Note: pump was 

set at 65 feet 

Secondary fracture

Foliation

Ambient

Pumping (recovery)

EXPLANATION

Water level

Ambient

outflow

Pumping

inflow

Pumping

inflow

Upper Piedmont Research Station  65
Figure 53. Geophysical logs of bedrock well MW–S1D at the Upper Piedmont research station, North Carolina.

0

10

20

30

40

50

60

70

80

90

100

110

120

130

140

150

160

170

180

190

200

210

220

230

240

250

260

270

280

290

300

0

10

20

30

40

50

60

70

80

90

100

110

120

130

140

150

160

170

180

190

200

210

220

230

240

250

260

270

280

290

300

-0.02 0.02

-0.02 0.02

Flow - ambient 

0 400

Gamma Log (APIU) 

6 7

Caliper (inch) 

Res (64N) (OHM-M) 

2,300 4,000

Res (16N) (OHM-M) 

2,400 2,800

Res (FL) (OHM-M) 

60 62

Temperature

(Degrees Fahrenheit) 

32 34

Heat Pulse Flowmeter

(gal/min)

Figure 53. Geophysical logs for bedrock well MW-S1D at the Upper Piedmont research

 station, North Carolina.

DEPTH, IN FEET BELOW LAND SURFACEDEPTH, IN FEET BELOW LAND SURFACE

Note: pump was 

set at 40 feet 

Flow - pumping (recovery)

Ambient

Pumping (recovery)

EXPLANATION

Water level

66  Water-Resources Data and Hydrogeologic Setting for Research Stations in the Piedmont and Blue Ridge, 2000–2004
DEPTH, IN FEET BELOW LAND SURFACE

0

20

60

40

80

100

120

140

160

180

200

220

240

260

280

300

320

340

360

380

400

420

440

0 90

Fracture/Foliation

Dip angle (degrees) 

N

S

EW

Example of tadpole 

showing dip azimuth 

-0.05 0.05

-2 2

Flow - ambient 

Flow - pumping Optical T eleviewer Image 

0 600

Gamma Log (APIU) 

0 90 180 270 0

N E S W N

6 9

Caliper (inch) 

Res (64N) (OHM-M) 

0 4,000

Res (16N) (OHM-M) 

0 3,000

Res (FL) (OHM-M) 

60 63

Temperature

(Degrees Fahrenheit) 

47 57

Heat Pulse Flowmeter

(gal/min)

Figure 54. Geophysical logs for bedrock well MW-S3D at the Upper Piedmont research station, North Carolina.

*Image obtained

in 6-inch

diameter well 

Camera

Line

Note: pump was 

set at 70 feet Secondary fracture

Primary fracture

Foliation

Ambient

Pumping

EXPLANATION

Water level

0

20

40

60

80

100

120

140

160

180

200

220

240

260

280

300

320

340

360

380

400

420

440

DEPTH, IN FEET BELOW LAND SURFACE

Pumping

inflow

Pumping

inflow

Ambient

outflow

Ambient

inflow

Figure 54. Geophysical logs of bedrock well MW–S3D at the Upper Piedmont research station, North Carolina.

Upper Piedmont Research Station  67
Figure 55. Geophysical logs of bedrock well MW–S4D at the Upper Piedmont research station, North Carolina. DEPTH, IN FEET BELOW LAND SURFACE

0

20

60

40

80

100

120

140

160

180

200

220

240

260

280

300

320

340

360

380

DEPTH, IN FEET BELOW LAND SURFACE

0

20

60

40

80

100

120

140

160

180

200

220

240

260

280

300

320

340

360

380

0 90

Fracture/Foliation

Dip angle (degrees)

N

S

EW

Example of tadpole

showing dip azimuth

-0.01 0.01

-1.5 1.5

Flow - ambient

Flow - pumping Optical Televiewer Image

0 300

Gamma Log (APIU)

0 90 180 270 0

N E S W N

6 15

Caliper (inch)

Res (64N) (OHM-M)

0 4,000

Res (16N) (OHM-M)

0 3,000

Res (FL) (OHM-M)

58 62

Temperature

(Degrees Fahrenheit)

30 55

Heat Pulse Flowmeter

(gal/min)

Figure 55. Geophysical logs for bedrock well MW-S4D at the Upper Piedmont research station, North Carolina.

Camera

lines

Note: pump was 

set at 55 feet 

Secondary fracture

Primary fracture

Foliation

Ambient

Pumping

EXPLANATION

Water level

*Image obtained

in 6-inch

diameter well 

Pumping

inflow

68  Water-Resources Data and Hydrogeologic Setting for Research Stations in the Piedmont and Blue Ridge, 2000–2004
Figure 56. Periodic ground-water levels recorded in well clusters (A) MW–N1, (B) MW–N2, (C) MW–N3, and (D) MW–N4 along the northern transect at the Upper Piedmont 

research station, North Carolina.

MW-N1S MW-N1I MW-N1D 

MW-N2SMW-N2IMW-N2D

MW-N3IMW-N3D

MW-N4IMW-N4D

672671670669668667666665664663662750740730720710700690

674672670668666664662660820815810805800795790

WATER-LEVEL ALTITUDE, IN FEET ABOVE NAVD 88

A. B.

WATER-LEVEL ALTITUDE, IN FEET ABOVE NAVD 88

WATER-LEVEL ALTITUDE, IN FEET ABOVE NAVD 88 WATER-LEVEL ALTITUDE, IN FEET ABOVE NAVD 88 C. D. 2002 WATER YEAR 2003 WATER YEAR 2004 WATER YEAR 2002 WATER YEAR 2003 WATER YEAR 2004 WATER YEAR

2002

WATER YEAR 

2003

WATER YEAR 

2004

WATER YEAR 2002

WATER YEAR

2003

WATER YEAR

2004

WATER YEAR

Figure 56. Periodic ground-water levels recorded in well clusters (A) MW-N1, (B) MW-N2, (C) MW-N3, and (D) MW-N4 along the northern transect at the Upper Piedmontresearch station, North Carolina.

MAY

02

JULY

02

SEPT.

02

MAY

03

JULY

03

SEPT.

03

NOV.

02

JAN.

03

MAR.

03

MAY

04

JULY

04

SEPT.

04

NOV.

03

JAN.

04

MAR.

04

MAY

02

JULY

02

SEPT.

02

MAY

03

JULY

03

SEPT.

03

NOV.

02

JAN.

03

MAR.

03

MAY

04

JULY

04

SEPT.

04

NOV.

03

JAN.

04

MAR.

04

MAY

02

JULY

02

SEPT.

02

MAY

03

JULY

03

SEPT.

03

NOV.

02

JAN.

03

MAR.

03

MAY

04

JULY

04

SEPT.

04

NOV.

03

JAN.

04

MAR.

04

MAY

02

JULY

02

SEPT.

02

MAY

03

JULY

03

SEPT.

03

NOV.

02

JAN.

03

MAR.

03

MAY

04

JULY

04

SEPT.

04

NOV.

03

JAN.

04

MAR.

04

Upper Piedmont Research Station  69
Figure 57. Periodic ground-water levels recorded in well clusters (A) MW–S1, (B) MW–S3, and (C) MW–S4 along the southern transect at the Upper Piedmont research station, 

North Carolina.

MW-S3SMW-S3UIMW-S3LIMW-S3D MW-S1I

MW-S1D

MW-S4SMW-S4IMW-S4D

795790785780775770765

688686684682680678676

A. B.

657656655654653

C.

2002

WATER YEAR 

2003

WATER YEAR 

2004

WATER YEAR 

2002

WATER YEAR 

2003

WATER YEAR 

2004

WATER YEAR 

MAY 

02

JULY 

02

2002

WATER YEAR 

2003

WATER YEAR 

2004

WATER YEAR 

SEPT. 

02

MAY 

03

JULY 

03

SEPT. 

03

NOV. 

02

JAN.

03

MAR.

03

MAY 

04

JULY 

04

SEPT. 

04

NOV. 

03

JAN.

04

MAR.

04

MAY 

02

JULY 

02

SEPT. 

02

MAY 

03

JULY 

03

SEPT. 

03

NOV. 

02

JAN.

03

MAR.

03

MAY 

04

JULY 

04

SEPT. 

04

NOV. 

03

JAN.

04

MAR.

04

MAY 

02

JULY 

02

SEPT. 

02

MAY 

03

JULY 

03

SEPT. 

03

NOV. 

02

JAN.

03

MAR.

03

MAY 

04

JULY 

04

SEPT. 

04

NOV. 

03

JAN.

04

MAR.

04

WATER-LEVEL ALTITUDE, IN FEET ABOVE NAVD 88

WATER-LEVEL ALTITUDE, IN FEET ABOVE NAVD 88

Figure 57. Periodic ground-water levels recorded in well clusters (A) MW-S1, (B) MW-S3, and (C) MW-S4 along the southern transect at the Upper Piedmontresearch station, North Carolina.

WATER-LEVEL ALTITUDE, IN FEET ABOVE NAVD 88

70 Water-Resources Data and Hydrogeologic Setting for Research Stations in the Piedmont and Blue Ridge, 2000–2004
Figure 58. Periodic ground-water levels recorded in piezometers at the Upper Piedmont research station, North Carolina.

672

671

670

669

668

667

666

665

WATER-LEVEL ALTITUDE, IN FEET ABOVE NAVD 88

JUNE JULY AUG. SEPT. NOV. DEC. OCT. JAN. FEB.

2003

MAR. APR. MAY AUG. SEPT. 

2004

JUNE JULY OCT. 

Figure 58. Periodic ground-water levels recorded in piezometers at the Upper Piedmont research station,

North Carolina.

PZ-1

PZ-2

PZ-3

PZ-4

PZ-5

PZ-5I

PZ-5D

PZ-6

PZ-6I

PZ-6D

PZ-7

PZ-7I

PZ-7D

PZ-8

2003

WATER YEAR

2004

WATER YEAR

Upper Piedmont Research Station  71
Figure 59. Hourly ground-water levels recorded in well cluster MW–S4 and continuous stage at the streamgaging station at the Upper 

Piedmont research station, North Carolina, May 2003 through October 2004.

MW-S4S

MW-S4I

MW-S4D

Wolf Island Creek

WATER -LEVEL ALTITUDE, IN FEET ABOVE NAVD 88

Figure 59. Hourly ground-water levels recorded in well cluster MW-S4 and continuous stage at the streamgaging

station at the Upper Piedmont research station, North Carolina May 2003 through October 2004.

662

661

660

659

658

657

656

655

654

JUNE 1 JULY 1 AUG. 1 SEPT. 1 OCT. 1 NOV. 1 DEC. 1 JUNE 1 JULY 1 AUG. 1 SEPT. 1 OCT. 1 NOV. 1

2003 2004

MAY 1 JAN. 1 FEB. 1 MAR. 1 APR. 1 MAY 1

72 Water-Resources Data and Hydrogeologic Setting for Research Stations in the Piedmont and Blue Ridge, 2000–2004
Figure 60. Hourly ground-water levels recorded in bedrock well MW–S3D at the Upper Piedmont research station, North Carolina, 

November 2003 through March 2004.

NOVEMBER DECEMBER

2003 2004

JANUARY FEBRUARY MARCH

Figure 60. Hourly ground-water levels recorded in bedrock well MW-S3D at the Upper Piedmont research station,

North Carolina, November 2003 through March 2004.

685.5

685.0

684.5

684.0

WATER-LEVEL ALTITUDE, IN FEET ABOVE NAVD 88

683.5

Upper Piedmont Research Station  73
Figure 61. The water 

chemistry of samples 

from (A) regolith and 

transition-zone wells, and 

surface-water sites, and 

(B) transition-zone and 

open-borehole bedrock 

wells at the Upper Piedmont 

research station, North 

Carolina.

MW-N1D

MW-N2D

MW-N3D

MW-N4D

MW-S1D

MW-S4D

MW-N2I

MW-N4I

MW-S4I

EXPLANATION

Figure 61. Water chemistry of samples from the (A) regolith and transition-zone wells, and surface-water

sites, and (B) open-borehole bedrock wells at the Upper Piedmont research station, North Carolina.

MW-N1S

MW-N2S

MW-S3S

MW-S4S

EXPLANATION

80

100

60

40

20

0

80

60

40

20

0

SULFATE PLUS CHLORIDE PLUS NITRATE

80

100

60

40

20

20

0

40

60

80

0 100 100

60 40 20

CALCIUM

CATIONS

100 80 0

20

40

60

80

100

20

40

60

80

0

20

40

60

80

MAGNESIUM

SODIUM PLUS POTASSIUM

40 60 80

CHLORIDE PLUS NITRATE

ANIONS

200 100

60 40 20

CALCIUM

CATIONS

100 80

B.

A.

0 40 60 80

CHLORIDE PLUS NITRATE

ANIONS

0 20 100

CARBONATE PLUS BICARBONATE

0 0

20

0

40

60

80

100 100

20

40

60

80

100

20

40

60

80

0

20

40

60

80

SODIUM PLUS POTASSIUM

CARBONATE PLUS BICARBONATE

80

100

60

40

20

0

SULFATE

80

100

60

40

20

0

MAGNESIUM

80

100

60

40

20

0

SULFATE

CALCIUM PLUS MAGNESIUM 

80

100

60

40

20

80

60

40

20 SULFATE PLUS CHLORIDE PLUS NITRATE

CALCIUM PLUS MAGNESIUM 

Carrol Creek 

Wolf Island Creek 

MW-N1I

MW-N3I

MW-S1I

MW-S3UI

MW-S3LI

2/25/04

12/10/02

12/10/02

3/23/04

12/11/02

4/7/04 12/19/02

4/29/04 4/6/04

12/11/02

4/22/04

4/29/04

4/21/04

12/12/02

12/10/02

2/25/04

3/10/04

12/11/02

3/23/04

12/9/02

3/24/04

12/12/02

4/28/04

4/15/04

12/10/02

3/24/04

12/9/02

12/12/02

4/6/04

12/11/02

12/11/02

74 Water-Resources Data and Hydrogeologic Setting for Research Stations in the Piedmont and Blue Ridge, 2000–2004
Figure 62. Major ion milliequivalents in water samples collected from (A) regolith wells and the surface-water sites 

(B) transition-zone wells, and (C) open-borehole bedrock wells at the Upper Piedmont research station, North Carolina, 

December 2002.

2

A.

1 1 2

CATIONS ANIONS

Sodium Chloride

MW-N1S

Calcium Bicarbonate

Magnesium Sulfate

Sodium Chloride

MW-N2S

Calcium Bicarbonate

Magnesium Sulfate

Sodium Chloride

Carrol Creek

Calcium Bicarbonate

Magnesium Sulfate

Sodium Chloride

MW-S3S

Calcium Bicarbonate

Magnesium Sulfate

Sodium Chloride

Calcium Bicarbonate

Magnesium Sulfate

Sodium Chloride

Wolf Island Creek

Calcium Bicarbonate

Magnesium Sulfate

5

B.

2.5 2.5 5

CATIONS ANIONS

Sodium Chloride

MW-N1I

Calcium Bicarbonate

Magnesium

Ammonia, as Nitrogen Ammonia, as Nitrogen

Ammonia, as Nitrogen

Ammonia, as Nitrogen

Ammonia, as Nitrogen Ammonia, as Nitrogen

Ammonia, as Nitrogen Ammonia, as Nitrogen

Ammonia, as Nitrogen

Ammonia, as Nitrogen

Ammonia, as Nitrogen Ammonia, as Nitrogen

Ammonia, as Nitrogen Ammonia, as Nitrogen Ammonia, as Nitrogen

Ammonia, as Nitrogen

Ammonia, as Nitrogen

Ammonia, as Nitrogen Ammonia, as Nitrogen

Sulfate

Sodium Chloride

MW-N2I

Calcium Bicarbonate

Magnesium Sulfate

Sodium Chloride

MW-N4I

Calcium Bicarbonate

Magnesium Sulfate

Sodium Chloride

MW-S1I

MW-S4S MW-S3UI

Calcium Bicarbonate

Magnesium Sulfate

Sodium Chloride

Calcium Bicarbonate

Magnesium Sulfate

MW-S3LI Sodium Chloride

Calcium Bicarbonate

Magnesium Sulfate

MW-S4I Sodium Chloride

Calcium Bicarbonate

Magnesium Sulfate

5

C.

2.5 2.5 5

CATIONS ANIONS

Sodium Chloride

MW-N1D

Calcium Bicarbonate

Magnesium Sulfate

Sodium Chloride

MW-N2D

Calcium Bicarbonate

Magnesium Sulfate

Sodium Chloride

MW-N3D

Calcium Bicarbonate

Magnesium Sulfate

Sodium Chloride

MW-N4D

MW-S1D

Calcium Bicarbonate

Magnesium Sulfate

Sodium Chloride

Calcium Bicarbonate

Magnesium Sulfate

MW-S4D Sodium Chloride

Calcium Bicarbonate

Magnesium Sulfate

Figure 62 . Stiff diagrams showing major ion milliequivalents in water samples collected from (A) the regolith wells and the 

surface-water site, (B) the transition-zone wells, and (C) the open-borehole bedrock wells at the Upper Piedmont research

station, North Carolina, December 2002. 

Nitrite plus Nitrate 

Nitrite plus Nitrate 

Nitrite plus Nitrate 

Nitrite plus Nitrate 

Nitrite plus Nitrate 

Nitrite plus Nitrate Nitrite plus Nitrate 

Nitrite plus Nitrate 

Nitrite plus Nitrate 

Nitrite plus Nitrate 

Nitrite plus Nitrate 

Nitrite plus Nitrate 

Nitrite plus Nitrate 

Nitrite plus Nitrate 

Nitrite plus Nitrate 

Nitrite plus Nitrate 

Nitrite plus Nitrate 

Nitrite plus Nitrate 

Nitrite plus Nitrate 

MILLIEQUIVALENTS PER LITER MILLIEQUIVALENTS PER LITER MILLIEQUIVALENTS PER LITER

Upper Piedmont Research Station  75
Figure 63. The range, median, and quartile statistical values for (A) pH, (B) specific 

conductance, and (C) dissolved oxygen for wells and surface-water sites during periodic 

sampling events at the Upper Piedmont research station, North Carolina.

Interquartile range (IQR):

adjacent data are within

1.5 times the IQR, while

detached data are outliers.

BEDROCK

(19)

TRANSITION

(6)

REGOLITH

(16)

SURFACE

WATER

(4)

8.1

7.6

7.1

6.6

6.1

5.6

5.1

pH, IN STANDARD UNITS

500

400

300

200

100

0

12

10

8

6

4

2

0

DISSOLVED OXYGEN, IN MILLIGRAMS 

PER LITER 

(19) Number of samples

Upper detached

EXPLANATION

Lower detached

Upper adjacent

Lower adjacent

Median

75th percentile

25th percentile

A.

B.

C.

SPECIFIC CONDUCTANCE, IN MICROSIEMENS PER

CENTIMETER AT 25 DEGREES CELSIUS

Figure 63. The range, median, and quartile

statistical values for (A) pH, (B) specific 

conductance, and (C) dissolved oxygen for 

wells and surface-water sites during periodic

sampling events at the Upper Piedmont research 

station, North Carolina.

76  Water-Resources Data and Hydrogeologic Setting for Research Stations in the Piedmont and Blue Ridge, 2000–2004
Figure 64. The range, median, and quartile statistical values for (A) calcium, (B) magnesium, 

and (C) sodium for wells and surface-water sites during periodic sampling events at the Upper 

Piedmont research station, North Carolina.

Interquartile range (IQR):

adjacent data are within

1.5 times the IQR, while

detached data are outliers.

BEDROCK

(19)

TRANSITION

(6)

REGOLITH

(16)

SURFACE

WATER

(4)

50

40

30

20

10

0

CALCIUM, IN MILLIGRAMS PER LITER

20

15

10

5

0

MAGNESIUM, IN MILLIGRAMS PER LITER

80

60

40

20

0

SODIUM, IN MILLIGRAMS PER LITER

Figure 64. The range, median, and quartile

statistical values for (A) calcium, (B) magnesium,

and (C) sodium for wells and surface-water 

sites during periodic sampling events at the 

Upper Piedmont research station, North Carolina.

Upper detached 

EXPLANATION

Lower detached 

Upper adjacent 

Lower adjacent 

Median

75th percentile 

25th percentile 

A.

B.

C.

(19) Number of samples

Upper Piedmont Research Station  77
Figure 65. The range, median, and quartile statistical values for (A) bicarbonate, (B) chloride, 

and (C) sulfate for wells and surface-water sites during periodic sampling events at the Upper 

Piedmont research station, North Carolina.

Interquartile range (IQR):

adjacent data are within

1.5 times the IQR, while

detached data are outliers.

250

200

150

100

50

0

25

20

15

10

5

0

100

80

60

40

20

0

(19) Number of samples

BEDROCK

(19)

TRANSITION

(6)

REGOLITH

(16)

SURFACE

WATER

(4)

Upper detached 

EXPLANATION

Lower detached 

Upper adjacent 

Lower adjacent 

Median

75th percentile 

25th percentile 

A.

B.

C.

BICARBONATE, IN MILLIGRAMS PER LITER CHLORIDE, IN MILLIGRAMS PER LITER SULFATE, IN MILLIGRAMS PER LITER

Figure 65. The range, median, and quartile

statistical values for (A) bicarbonate, (B) chloride,

and (C) sulfate for wells and surface-water 

sites during periodic sampling events at the 

Upper Piedmont research station, North Carolina.

78  Water-Resources Data and Hydrogeologic Setting for Research Stations in the Piedmont and Blue Ridge, 2000–2004
Figure 66. Hourly record of (A) temperature, (B) pH, (C) specific conductance, and (D) dissolved oxygen in well MW–S4S in the shallow 

regolith at the Upper Piedmont research station, North Carolina.

No data 

No data 

JUNE JULY 

2003 WATER YEAR 2004 WATER YEAR 

AUG. SEPT. OCT. NOV. DEC. JAN. FEB. MAR. APR. MAY JUNE JULY AUG. SEPT. 

2.0

1.5

1.0

0.5

0

-0.5

DISSOLVED OXYGEN,

-1.0

IN MILLIGRAMS 

PER LITER

350

340

330

320

310

300

SPECIFIC CONDUCTANCE,

IN MICROSIEMENS PER

CENTIMETER AT 25

DGREES CELSIUS

18

17

16

15

14

13

12

11

10

9

WATER TEMPERATURE, 

IN DEGREES CELSIUS 

7.5

7.0

6.5

6.0

5.5

pH

A.

B.

C.

D.

Figure 66. Hourly record of (A) temperature, (B) pH, (C) specific conductance, and (D) dissolved oxygen in well MW-S4S

in the shallow regolith at the Upper Piedmont research station, North Carolina.

Upper Piedmont Research Station  79
Figure 67. Hourly record of (A) temperature, (B) pH, (C) specific conductance, and (D) dissolved oxygen in well MW–S4I in the transition 

zone at the Upper Piedmont research station, North Carolina.

JUNE JULY 

2003 WATER YEAR 2004 WATER YEAR 

AUG. SEPT. OCT. NOV. DEC. JAN. FEB. MAR. APR. MAY JUNE JULY AUG. SEPT. 

2.0

1.5

1.0

0.5

0

-0.5

DISSOLVED OXYGEN, 

-1.0

IN MILLIGRAMS

PER LITER 

330

320

310

300

290

280

270

15.0

14.5

14.0

13.5

13.0

12.5

WATER TEMPERATURE, 

IN DEGREES CELSIUS 

7.8

7.6

7.4

7.2

7.0

6.8

6.6

pH

A.

B.

C.

D.

SPECIFIC CONDUCTANCE,

IN MICROSIEMENS PER

CENTIMETER AT 25

DGREES CELSIUS

Figure 67. Hourly record of (A) temperature, (B) pH, (C) specific conductance, and (D) dissolved oxygen in well MW-S4I

in the transition zone at the Upper Piedmont research station, North Carolina.

80 Water-Resources Data and Hydrogeologic Setting for Research Stations in the Piedmont and Blue Ridge, 2000–2004
Figure 68. Hourly record of (A) temperature, (B) pH, (C) specific conductance, and (D) dissolved oxygen in well MW–S4D in the 

bedrock at the Upper Piedmont research station, North Carolina.

JUNE JULY 

2003 WATER YEAR 2004 WATER YEAR 

AUG. SEPT. OCT. NOV. DEC. JAN. FEB. MAR. APR. MAY JUNE JULY AUG. SEPT. 

2.0

1.5

1.0

0.5

0

DISSOLVED OXYGEN, 

-0.5

IN MILLIGRAMS

PER LITER 

420

400

380

360

340

320

300

280

14.85

14.80

14.75

14.70

14.65

14.60

WATER TEMPERATURE, 

IN DEGREES CELSIUS 

8.5

8.0

7.5

7.0

6.5

6.0

pH

A.

B.

C.

D.

SPECIFIC CONDUCTANCE,

IN MICROSIEMENS PER

CENTIMETER AT 25

DGREES CELSIUS

Figure 68. Hourly record of (A) temperature, (B) pH, (C) specific conductance, and (D) dissolved oxygen in well MW-S4D

in the bedrock at the Upper Piedmont research station, North Carolina.

Upper Piedmont Research Station  81
Figure 69. Fifteen-minute record of (A) temperature, (B) pH, (C) specific conductance, and (D) dissolved oxygen in Wolf Island Creek 

at the Upper Piedmont research station, North Carolina.

JUNE JULY 

2003 WATER YEAR 2004 WATER YEAR 

AUG. SEPT. OCT. NOV. DEC. JAN. FEB. MAR. APR. MAY JUNE JULY AUG. SEPT. 

15

10

5

DISSOLVED OXYGEN, 

0

IN MILLIGRAMS

PER LITER 

800

600

400

200

0

30

20

10

0

-10

WATER TEMPERATURE, 

IN DEGREES CELSIUS 

8.0

7.5

7.0

6.5

6.0

5.5

pH

A.

B.

C.

D.

SPECIFIC CONDUCTANCE,

IN MICROSIEMENS PER

CENTIMETER AT 25

DGREES CELSIUS

Figure 69. 15-minute record of (A) temperature, (B) pH, (C) specific conductance, and (D) dissolved oxygen in Wolf Island Creek

at the Upper Piedmont research station, North Carolina.

82 Water-Resources Data and Hydrogeologic Setting for Research Stations in the Piedmont and Blue Ridge, 2000–2004
were temperature, pH, SC, and DO concentrations. Water 

temperature at well cluster MW–S4 ranged from about 10.5 to 

16.5 °C in the shallow zone, from about 13.5 to 14.5 °C in 

the transition zone, and from about 14.7 to 14.8 °C in the 

bedrock zone. Specific conductance ranged from about 320 to 

340 μS/cm in the shallow zone, from about 290 to 320 μS/cm 

in the transition zone, and from about 300 to 400 μS/cm in 

the bedrock zone. The pH ranged from about 6.3 to 6.7 in the 

shallow zone, from about 6.8 to 7.6 in the transition zone, and 

from about 7.0 to 8.0 in the bedrock zone. Dissolved-oxygen 

concentrations ranged from about 0.1 to 0.5 mg/L in all three 

zones. Water temperature in Wolf Island Creek ranged from 

0 to 25 °C, SC ranged from about 100 to 200 μS/cm, pH 

ranged from about 6.5 to 7.5, and DO concentrations ranged 

from about 6 to 12 mg/L.

Bent Creek Research Station

Site Description and Geology

The first hydrogeologic research station installed in 

the DWQ Asheville Region of North Carolina as part of 

the PMREP is the Bent Creek research station (BCRS) in 

Buncombe County (fig. 70). The BCRS is located in the Bent 

Creek Experimental Forest, which is maintained by the U.S. 

Department of Agriculture Forest Service. The Bent Creek 

Experimental Forest is a 5,200-acre tract of land in the Bent 

Creek valley of the Pisgah National Forest that has been set 

aside for experimental and demonstration purposes. The 

BCRS, as defined for this study, consists of approximately 

260 acres about 8 miles southwest of the center of Asheville, 

NC.

The BCRS lies in the Blue Ridge litho-tectonic belt 

of the Blue Ridge Physiographic Province and is underlain 

by interlayered and metamorphosed sedimentary and mafic 

volcanic rock of the Ashe Metamorphic Suite (Merschat 

and Carter, 2002). Regionally, the hydrogeologic unit map 

constructed by Daniel and Dahlen (2002) shows the BCRS to 

be located in the quartzite (QTZ) hydrogeologic unit (fig. 70). 

Based on geologic coring at the site, however, the BCRS is 

underlain mainly by interlayered, migmatitic schist and(or) 

metagraywacke. As mapped by Merschat and Carter (2002), 

the dominant lithologies at land surface in the Bent Creek 

drainage basin are garnet-sillimanite-mica-bearing schist, 

garnet-sillimanite-mica-bearing metasiltstone, and garnetbearing metagraywacke. Amphibolite and metaconglomerate 

occur locally but are relatively sparse. Areas of high 

migmatization occur primarily in the southwestern part of 

the basin. Other rock bodies in the basin are considered to be 

minor, discontinuous, and localized. Strong foliation occurs 

in the schist and metasiltstone; weak or little foliation occurs 

in the metagraywacke and migmatite. Work that has been 

conducted from July 2002 to September 2004 at the BCRS 

includes the collection and logging of seven soil and rock 

cores totaling 830 ft, installation of 18 monitoring wells 

grouped into six clusters along a transect, installation of 

15 piezometers for water-level and aquifer-test monitoring, 

installation of a real-time DCP for continuous monitoring 

of water levels and water quality in a three-well cluster and 

the adjacent stream, monthly collection of water levels, 

semiannual sampling of wells, slug tests, 72-hour aquifer test, 

and borehole geophysical logs.

Well Construction

During this investigation, six ground-water monitoringwell clusters, consisting of three wells each along with 15 

piezometers were constructed at the BCRS (fig. 71; table 7). 

The piezometers were arranged in seven clusters, each 

consisting of one well in the shallow regolith and one well in 

the transition zone with the exception of PZ–3S, which was 

not paired with a transition-zone well. Well cluster locations 

were selected to obtain water-quality and water-level data 

along a topographic transect encompassing areas of recharge 

and discharge based on conceptual models developed for the 

slope-aquifer system (LeGrand and Nelson, 2004). Criteria 

for well locations included topographic setting, accessibility, 

and site boundaries. Cross section A–A' was constructed 

along the well transect from well cluster MW–7, located in 

a conceptual recharge area, to well cluster MW–2, located in 

a discharge area near two streams—Boyd Branch and Bent 

Creek (figs. 71, 72).

Each well cluster at the BCRS consists of three wells—a 

shallow water-level well to monitor ground-water conditions 

in the regolith, a transition-zone well to monitor ground-water 

conditions in the partially weathered rock and open fractures 

near the top of bedrock, and a deeper bedrock well to monitor 

ground water in the fractured bedrock aquifer (fig. 72). Wellconstruction information is provided in table 7. 

Water-Resources Data

Borehole geophysical logs were collected from all six 

bedrock wells at the BCRS. Data collected from these wells 

include caliper, natural gamma, short-normal and longnormal resistivity logs; fluid-temperature and fluid-resistivity 

logs; heat-pulse flowmeter data (both ambient and stressed 

conditions); and OTV images (figs. 73–78). 

Monthly water levels have been measured in all 18 

wells since February 2003 at the BCRS (fig. 79). The period 

of record discussed in this report is February 2003 through 

September 2004. Ground-water altitudes at well cluster 

MW–1 ranged from about 2,197 to 2,198 ft in the shallow 

zone, from about 2,197 to 2,199 ft in the transition zone, 

and from about 2,196 to 2,199 ft in the bedrock zone. The 

water-level altitudes in the transition zone were consistently 

higher than water-level altitudes in the shallow and bedrock 

zones at well cluster MW–1. Ground-water altitudes at well 

Bent Creek Research Station  83
Figure 70. Locations of Bent Creek research station, hydrogeologic units in Buncombe County, and geologic belts delineated in North 

Carolina (modified from North Carolina Geological Survey, 1985; Daniel and Payne, 1990).

0 10 20 MILES

0 8 16 KILOMETERS

Base from digital files of:

U.S. Department of Commerce, Bureau of Census,

 1990 Precensus TIGER/Line Files-Political boundaries, 1991

U.S. Environmental Protection Agency, River File 3

U.S. Geological Survey, 1:100,000 scale 

SR Tr-DRB

Sauratown Mtn. ant.

SR

Tr-DCB

Tr-DRB

CS

CP

Sauratown Mountains anticlinorium

Smith River allochthon

Davie County Triassic basin

Dan River Triassic basin

Carolina Slate Belt

Western margin of Coastal Plain Physiographic Province

Boundary between Blue Ridge and Piedmont

 Physiographic Provinces

Thrust fault with teeth on upthrown block

Piedmont Coastal Plain Blue Ridge

34

35

36

84 83 82 81 80 79 78 77 76

Brevard fault zone

TENNESSEE

VIRGINIA

SOUTH CAROLINA

GEORGIA

EXPLANATION

0 25 50 75 100 MILES

0 25 50 75 100 KILOMETERS

Atlantic

Ocean

EXPLANATION

Bent Creek research station

HYDROGEOLOGIC UNITS

(Daniel and Payne, 1990)

Gneiss, felsic (GNF)

Gneiss, mafic (GNM)

Metaigneous, felsic (MIF)

Metaigneous, mafic (MIM)

Quartzite (QTZ)

Igneous, mafic intrusive (IMI)

Figure 70. Locations of Bent Creek research station, hydrogeologic units in Buncombe County, and geologic belts delineated in 

North Carolina (modified from NCGS, 1985; Daniel and Payne, 1990).

N

Asheville

GNM

MIM

MIM

MIF

GNM

GNF

GNM

GNF

GNM

GNM

GNM

QTZ

IMI

QTZ

MIM

IMI

GNM

GNF

GNF

Murphy Belt

Blue

Ridge

Belt

Chauga

Belt

Inner

Piedmont

Belt

Charlotte

Belt

Belt

Subbasin

Tr-DCB

Kings

Mtn.

Gold Hill

shear zone

CS

Belt

Milton

Sauratown Mtn.

ant.

CP

Tr-Wadesboro

CS CP

Carolina

Slate

Belt

Eastern

Slate

Belt

Raleigh

Sanford

-Durham

Buncombe

County

CP

84 Water-Resources Data and Hydrogeologic Setting for Research Stations in the Piedmont and Blue Ridge, 2000–2004
Figure 71. Aerial photograph overlaid with topographic features showing locations of well clusters, surface-water sites, 

and line of section A–A’ at the Bent Creek research station in Buncombe County, North Carolina.

Figure 71. Aerial photograph, topographic features, locations of well clusters

and line of section at the Bent Creek research station in Buncombe County,

North Carolina.

2,680 2,600

2,440

2,400

2,480

2,440

2,480

2,400

2,560

2,600

2,680

2,280

2,320

2,280

2,280

2,360

2,200

A A'

EXPLANATION 

Cross section

Altitude of land surface above

 NAVD 88. Contour interval 

 is 40 feet

Well and cluster number

Piezometer and cluster number

USGS streamgaging station

Surface-water sampling site

2,520

A'

A

MW-7

cluster

MW-5

cluster PZ-8

cluster

PZ-6

cluster

PZ-5

cluster PZ-2

cluster

PZ-7

cluster

PZ-1

cluster

PZ-4

cluster

PZ-3

cluster

MW-4

cluster

MW-2

cluster

MW-2

PZ-4

MW-3 

cluster

MW-1

cluster

2,520

2,400

2,200

2,560

2,440

2,280

Base from:

1998 photograph from Buncombe County, 

North Carolina GIS database

Contours 1993 USGS topographic sheet, 

Dunsmore Mountain Quadrangle, 1:24,000 scale

Boyd

Branch

Bent

Cr.

0 800 1,600 FEET

0 200 400 METERS 

N

Bent Creek Research Station  85
Table 7. Construction characteristics of monitoring wells and the surface-water site at the Bent Creek Research Station, North Carolina.

[NAVD 88, North American Vertical Datum of 1988; MW, monitoring well; S, shallow; PVC, polyvinyl chloride casing; R, regolith; I, transition zone; D, deep; B, bedrock; PZ, piezometer; na, not applicable; SW, surface water]

Site 

identification

Station 

name

Construction 

date

Land-surface 

altitude 

(feet above 

NAVD 88)

Casing 

material

Casing 

diameter 

(inches)

Screened interval or open 

borehole interval (feet below 

land surface)

Screen 

type

Zone 

monitored

from to

352840082381001 MW–1S 10/17/2002 2,200.99 PVC 4.0 8 22 0.01 slotted PVC

R

352840082381002 MW–1I 10/16/2002 2,202.52 PVC 4.0 38 53 0.01 slotted PVC I

352840082381003 MW–1D 10/8/2002 2,201.77 PVC 6.0 55 221 Open hole

B

352854082380501 MW–2S 10/30/2002 2,190.69 PVC 4.0 5 20 0.01 slotted PVC

R

352854082380502 MW–2I 10/24/2002 2,191.72 PVC 4.0 21 36 0.01 slotted PVC I

352854082380503 MW–2D 10/22/2002 2,190.15 PVC 6.0 53 300 Open hole

B

352856082381201 MW–3S 10/3/2002 2,210.12 PVC 4.0 15 30 0.01 slotted PVC

R

352856082381202 MW–3I 10/3/2002 2,209.45 PVC 4.0 35 50 0.01 slotted PVC I

352856082381203 MW–3D 9/17/2002 2,209.07 PVC 6.0 61 300 Open hole

B

352808082382601 MW–4S 9/12/2002 2,259.66 PVC 4.0 7 22 0.01 slotted PVC

R

352808082382602 MW–4I 9/11/2002 2,258.80 PVC 4.0 26 41 0.01 slotted PVC I

352808082382603 MW–4D 8/29/2002 2,258.53 PVC 6.0 61 501 Open hole

B

352810082383501 MW–5S 8/8/2002 2,299.99 PVC 4.0 9 24 0.01 slotted PVC

R

352810082383502 MW–5I 8/22/2002 2,302.19 PVC 4.0 32 47 0.01 slotted PVC I

352810082383503 MW–5D 8/12/2002 2,304.84 PVC 6.0 62 300 Open hole

B

352827082383901 MW–7S 7/17/2002 2,368.23 PVC 4.0 10 25 0.01 slotted PVC

R

352827082383902 MW–7I 7/16/2002 2,369.04 PVC 4.0 30 50 0.01 slotted PVC I

352827082383903 MW–7D 7/9/2002 2,369.88 PVC 6.0 62 285 Open hole

B

352909082382801 PZ–1S 6/16/2004 2,260a PVC 2.0 12 17 0.01 slotted PVC

R

352909082382802 PZ–1I 6/15/2004 2,260a PVC 2.0 25 30 0.01 slotted PVC I

352907082382501 PZ–2S 6/22/2004 2,255a PVC 2.0 17 22 0.01 slotted PVC

R

352907082382502 PZ–2I 6/23/2004 2,255a PVC 2.0 54 59 0.01 slotted PVC I

352907082382401 PZ–3S 6/23/2004 2,254a PVC 2.0 17 22 0.01 slotted PVC

R

352904082382001 PZ–4S 6/24/2004 2,235a PVC 2.0 12 17 0.01 slotted PVC

R

352904082382002 PZ–4I 6/24/2004 2,235a PVC 2.0 25 30 0.01 slotted PVC I

352908082382701 PZ–5S 6/30/2004 2,260a PVC 2.0 12 17 0.01 slotted PVC

R

352908082382702 PZ–5I 6/30/2004 2,260a PVC 2.0 24 29 0.01 slotted PVC I

352909082382701 PZ–6S 7/13/2004 2,260a PVC 2.0 17 22 0.01 slotted PVC

R

352909082382702 PZ–6I 7/1/2004 2,260a PVC 2.0 29 34 0.01 slotted PVC I

352911082383101 PZ–7S 7/14/2004 2,275a PVC 2.0 8 13.5 0.01 slotted PVC

R

352911082383102 PZ–7I 7/20/2004 2,275a PVC 2.0 20 25 0.01 slotted PVC I

352912082382601 PZ–8S 7/14/2004 2,260a PVC 2.0 15 20 0.01 slotted PVC

R

352912082382602 PZ–8I 7/14/2004 2,260a PVC 2.0 29 34 0.01 slotted PVC I

0344789265 Boyd Branch 3/17/2004 2,190 na na na na na SW

aPiezometer altitudes from U.S. Geological Survey 7.5-minute topographic quadrangle map (+/– 10 feet).

86  Water-Resources Data and Hydrogeologic Setting for Research Stations in the Piedmont and Blue Ridge, 2000–2004
Figure 72. Generalized hydrogeologic cross section A–A’ along the well transect at the Bent Creek research station, North Carolina 

(section location is shown in figure 71).

Regolith

Transition zone

Bedrock

Open

borehole

Well

casing

A A'

0 300 600 900 1,200 FEET

0 60 120 180 240 300 METERS

2,500

2,400

2,300

2,200

2,100

2,000

1,900

1,800

7I 7S7D

5S5D5I

Land surface

4I4D4S

3S 3D3I 2I 2D2S

ALTITUDE, IN FEET ABOVE NAVD 88

Bent

Creek

MW-7

cluster

MW-5

cluster

MW-4

cluster

MW-3

cluster MW-2

cluster

Foliation

1,757.53 feet

Vertical exaggeration = 6.7 times scale

Bent Creek Research Station  87
Figure 73. Geophysical logs of bedrock well MW–1D at the Bent Creek research station, North Carolina.

Note: pump was 

set at 35 feet 

Flow - pumping 

-1.5 1.5

Flow - ambient

-1 1

Heat Pulse Flowmeter 

(gal/min)

0

102030405060708090

100110120130140150160170180190200210220

Optical Televiewer Image 

0 400

Gamma Log (APIU) 

0 0 90 180 270 

N E S W N

0 90

Fracture/Foliation

Dip angle (degrees) 

N

S

EW

Example of tadpole showing dip azimuth 

6 7

Caliper (inch) 

Res (64N) (OHM-M) 

0 4,000

Res (16N) (OHM-M) 

0 4,000

Res (FL) (OHM-M) 

58 61

Temperature

(Degrees Fahrenheit) 

50 250

Figure 73. Geophysical logs for bedrock well MW-1D at the Bent Creek research station, North Carolina.

Camera Line 

*Image obtained in 6-inch diameter well 

EXPLANATION

Primary fractureSecondary fractureFoliationAmbientPumping

Water level

DEPTH, IN FEET BELOW LAND SURFACE

DEPTH, IN FEET BELOW LAND SURFACE

0

10

20

3040506070

80

90100110120130140150160170

180190200210220

Water-bearing

fracture

Pumping

inflow

88  Water-Resources Data and Hydrogeologic Setting for Research Stations in the Piedmont and Blue Ridge, 2000–2004
Figure 74. Geophysical logs of bedrock well MW–2D at the Bent Creek research station, North Carolina.

0

10

20

30

40

50

60

70

80

90

100

110

120

130

140

150

160

170

180

190

200

210

220

230

240

250

260

270

280

290

300

DEPTH, IN FEET BELOW LAND SURFACE

0

10

20

30

40

50

60

70

80

90

100

110

120

130

140

150

160

170

180

190

200

210

220

230

240

250

260

270

280

290

300

DEPTH, IN FEET BELOW LAND SURFACE

N

S

EW

Example of tadpole

showing dip azimuth

-0.2 0.2

-0.4 0.4

Flow - ambient

Figure 74. Geophysical logs for bedrock well MW-2D at the Bent Creek research station, North Carolina.

Optical Televiewer Image

0 400

Gamma Log (APIU)

0 90 180 270 0

N E S W N

0 90

Fracture/Foliation

Dip angle (degrees)

6 7

Caliper (inch)

Res (64N) (OHM-M)

1,000 4,000

Res (16N) (OHM-M)

1,000 4,000

Res (FL) (OHM-M)

58 62

Temperature

(Degrees Fahrenheit)

37 42

Heat Pulse Flowmeter

(gal/min)

Camera Lines 

*Image obtained

in 6-inch

diameter well 

Ambient

inflow

Pumping

inflow

Note: pump was 

set at 35 feet 

Flow - pumping (recovery)

Secondary fracture

Foliation

Ambient

Pumping (Recovery)

EXPLANATION

Water level

Bent Creek Research Station  89
Figure 75. Geophysical logs of bedrock well MW–3D at the Bent Creek research station, North Carolina.

Heat Pulse Flowmeter

(gal/min)

Optical Televiewer Image

0 400

Gamma Log (APIU)

0 90 180 270 0

N E S W N

0 90

Fracture/Foliation

Dip angle (degrees)

6 7

Caliper (inch)

Res (64N) (OHM-M)

0 4,000

Res (16N) (OHM-M)

0 4,000

Res (FL) (OHM-M)

57 62

Temperature

(Degrees Fahrenheit)

50 200

0

10

20

30

40

50

60

70

80

90

100

110

120

130

140

150

160

170

180

190

200

210

220

230

240

250

260

270

280

290

300

DEPTH, IN FEET BELOW LAND SURFACEDEPTH, IN FEET BELOW LAND SURFACE

0

10

20

30

40

50

60

70

80

90

100

110

120

130

140

150

160

170

180

190

200

210

220

230

240

250

260

270

280

290

300

N

S

EW

Example of tadpole

showing dip azimuth

Secondary fracture

Primary fracture

Foliation

Ambient

Pumping (Recovery)

EXPLANATION

-0.02 0.02

-0.2 0.2

Flow - ambient

Flow - pumping (recovery)

Camera Line 

Figure 75. Geophysical logs for bedrock well MW-3D at the Bent Creek research station, North Carolina.

*Image obtained

in 6-inch

diameter well 

Pumping

inflow

Note: pump was 

set at 40 feet 

Water level

Ambient

outflow

90 Water-Resources Data and Hydrogeologic Setting for Research Stations in the Piedmont and Blue Ridge, 2000–2004
Figure 76. Geophysical logs of bedrock well MW–4D at the Bent Creek research station, North Carolina.

Optical Televiewer Image

0 400

Gamma Log (APIU)

0 90 180 270 0

N E S W N

0 90

Fracture/Foliation

Dip angle (degrees)

6 7

Caliper (inch)

Res (64N) (OHM-M)

0 4,000

Res (16N) (OHM-M)

0 4,000

Res (FL) (OHM-M)

57 62

Temperature

(Degrees Fahrenheit)

50 200

0

20

40

60

80

100

120

140

160

180

200

220

240

260

280

300

320

340

360

380

400

420

440

460

480

500

DEPTH, IN FEET BELOW LAND SURFACE

0

20

40

60

80

100

120

140

160

180

200

220

240

260

280

300

320

340

360

380

400

420

440

460

480

500

DEPTH, IN FEET BELOW LAND SURFACE

N

S

EW

Example of tadpole

showing dip azimuth

-0.02 0.02

-1.5 1.5

Flow - ambient

Flow - pumping

Figure 76. Geophysical logs for bedrock well MW-4D at the Bent Creek research station, North Carolina. 

Note: pump was 

set at 50 feet 

Heat Pulse Flowmeter

(gal/min)

Secondary fracture

Primary fracture

Foliation

Ambient

Pumping

EXPLANATION

Water level

Camera Line 

*Image obtained

in 6-inch

diameter well 

Pumping

inflow

Bent Creek Research Station  91
Figure 77. Geophysical logs of bedrock well MW–5D at the Bent Creek research station, North Carolina.

0

10

20

30

40

50

60

70

80

90

100

110

120

130

140

150

160

170

180

190

200

210

220

230

240

250

260

270

280

290

300

0

10

20

30

40

50

60

70

80

90

100

110

120

130

140

150

160

170

180

190

200

210

220

230

240

250

260

270

280

290

300

N

S

EW

Example of tadpole

showing dip azimuth

Secondary fracture

Foliation

EXPLANATION

-0.03 0.03

-0.2 0.2

Flow - ambient

Heat Pulse Flowmeter

(gal/min)

Ambient

Pumping (recovery)

Optical Televiewer Image

0 400

Gamma Log (APIU)

0 90 180 270 0

N E S W N

0 90

Fracture/Foliation

Dip angle (degrees)

6 7

Caliper (inch)

Res (64N) (OHM-M)

0 4,000

Res (16N) (OHM-M)

0 4,000

Res (FL) (OHM-M)

58 61

Temperature

(Degrees Fahrenheit)

130 140

Flow - pumping (recovery)

Figure 77. Geophysical logs for bedrock well MW-5D at the Bent Creek research station, North Carolina.

Note: pump was 

set at 22 feet 

Water level

Camera Lines 

DEPTH, IN FEET BELOW LAND SURFACEDEPTH, IN FEET BELOW LAND SURFACE

*Image obtained

in 6-inch

diameter well 

Pumping

inflow

92 Water-Resources Data and Hydrogeologic Setting for Research Stations in the Piedmont and Blue Ridge, 2000–2004
Figure 78. Geophysical logs of bedrock well MW–7D at the Bent Creek research station, North Carolina.

0

10

20

30

40

50

60

70

80

90

100

110

120

130

140

150

160

170

180

190

200

210

220

230

240

250

260

270

280

290

300

0

10

20

30

40

50

60

70

80

90

100

110

120

130

140

150

160

170

180

190

200

210

220

230

240

250

260

270

280

290

300

N

S

EW

Example of tadpole

showing dip azimuth

-0.05 0.05

-0.5 0.5

Flow - ambient

Flow - pumping

Figure 78. Geophysical logs for bedrock well MW-7D at the Bent Creek research station, North Carolina. 

Heat Pulse Flowmeter

(gal/min)

Optical Televiewer Image

0 500

Gamma Log (APIU)

0 90 180 270 0

N E S W N

0 90

Fracture/Foliation

Dip angle (degrees)

6 7

Caliper (inch)

Res (64N) (OHM-M)

0 4,000

Res (16N) (OHM-M)

0 4,000

Res (FL) (OHM-M)

58 62

Temperature

(Degrees Fahrenheit)

50 250

Secondary fracture

Foliation

Ambient

Pumping

EXPLANATION

Water level

DEPTH, IN FEET BELOW LAND SURFACEDEPTH, IN FEET BELOW LAND SURFACE

Camera Lines

*Image obtained

in 6-inch

diameter well 

Note: pump was 

set at 40 feet 

Pumping

inflow

Pumping

inflow

Bent Creek Research Station  93
Figure 79. Periodic ground-water levels recorded in well clusters (A) MW–1, (B) MW–2, (C) MW–3, (D) MW–4, (E) MW–5, and (F) MW–7 at 

the Bent Creek research station, North Carolina.

Figure 79. Periodic ground-water levels recorded in well clusters (A) MW-1, (B) MW-2, (C) MW-3, (D) MW-4, (E) MW-5, and 

(F) MW-7 at the Bent Creek research station, North Carolina.

2,200

2,199

2,198

2,197

2,196

2,204

2,203

2,202

2,201

2,200

2,199

2,297

2,296

2,295

2,294

2,293

2/1 4/1

Water Year 2003 Water Year 2004 

6/1 8/1 10/1 12/1 2/1 4/1 6/1 8/1 10/1 2/1 4/1 6/1 8/1 10/1 12/1 2/1 4/1 6/1 8/1 10/1

2/1 4/1 6/1 8/1 10/1 12/1 2/1 4/1 6/1 8/1 10/1 2/1 4/1 6/1 8/1 10/1 12/1 2/1 4/1 6/1 8/1 10/1

2/1 4/1 6/1 8/1 10/1 12/1 2/1 4/1 6/1 8/1 10/1 2/1 4/1 6/1 8/1 10/1 12/1 2/1 4/1 6/1 8/1 10/1

A.

2,187

2,186

2,185

2,184

2,183

2,182

B.

C.

2,254

2,253

2,252

2,251

2,250

2,249

2,248

2,247

2,246

2,245

D.

E.

2,360

2,359

2,358

2,357

2,356

2,355

F.

WATER-LEVEL ALTITUDE, IN FEET ABOVE NAVD 88

MW-1S

MW-1I

MW-1D

MW-2S

MW-2I

MW-3S

MW-3I

MW-3D

MW-4S

MW-4I

MW-4D

MW-5S

MW-5I

MW-5D

MW-7S

MW-7I

MW-7D

Water Year 2003 Water Year 2004 

Water Year 2003 Water Year 2004 Water Year 2003 Water Year 2004 

Water Year 2003 Water Year 2004 Water Year 2003 Water Year 2004 

94 Water-Resources Data and Hydrogeologic Setting for Research Stations in the Piedmont and Blue Ridge, 2000–2004
cluster MW–2 ranged from about 2,183 to 2,186 ft in the 

shallow and transition zones. The ground-water altitude for 

the bedrock zone at well cluster MW–2 was higher than the 

casing (flowing), and water-level altitudes were not accurately 

measured. Ground-water altitudes at well cluster MW–3 

ranged from about 2,201 to 2,203 ft in the shallow zone, from 

about 2,201 to 2,202.5 ft in the transition zone, and from 

about 2,200 to 2,201 ft in the bedrock zone. Ground-water 

altitudes at well cluster MW–4 ranged from about 2,250 to 

2,253 ft in the shallow zone, from about 2,249.5 to 2,252 ft 

in the transition zone, and from about 2,246 to 2,248 ft in the 

bedrock zone. Ground-water altitudes at well cluster MW–5 

ranged from about 2,294 to 2,297 ft in the shallow zone, from 

about 2,293.5 to 2,296 ft in the transition zone, and from about 

2,293 to 2,296 ft in the bedrock zone. Ground-water altitudes 

at well cluster MW–7 ranged from about 2,356.5 to 2,359 ft 

in the shallow zone and from about 2,356 to 2,357 ft in the 

transition and bedrock zones. The water-level altitudes for 

the shallow zone were consistently higher than water-level 

altitudes in the transition and bedrock zones at well clusters 

MW–3, MW–4, MW–5, and MW–7. Periodic water-level data 

collection in the piezometers, the collection of hourly groundwater levels and water quality at cluster MW–2, and the 

collection of 15-minute surface-water stage and water quality 

at Boyd Branch did not begin until late in water year 2004 and 

are not included in this report. Detailed summaries of groundwater-level data recorded in the BCRS wells for water years 

2003 and 2004 are published in USGS annual data reports for 

North Carolina (Howe and others, 2004, 2005). 

Slug tests were conducted in 11 wells at the BCRS 

in April and September 2004. Either a 5-ft long, 3-inch 

diameter solid PVC slug or a 5-ft long, 4-inch solid PVC 

slug was used to displace water in the wells. Slug tests were 

conducted to estimate hydraulic conductivity in the three 

aquifer zones tapped by the wells—the regolith, transition 

zone, and bedrock. The estimates obtained are representative 

of conditions in the immediate vicinity of the tested wells. A 

summary of hydraulic conductivity values is given in table 8.

Water-quality samples were collected from all wells 

(excluding the piezometers) and two streams (Boyd Branch 

and Bent Creek) at the BCRS during April 2003. Major ion 

concentrations by ground-water zone are displayed in Piper 

(fig. 80) and Stiff diagrams (fig. 81); ranges in values of major 

ion concentrations and physical properties are shown in box 

plots (figs. 82–84).

Continuous real-time data collection began in July 2004 

in all three wells in cluster MW–2 and in the nearby stream 

(Boyd Branch, station 0344789265), but not enough data 

have been collected to present in this report. Collection of 

continuous water-quality and water-level data in well cluster 

MW–2 began in August 2004. Continuous stage data in the 

stream have been recorded since March 2004, and waterquality data collection in the stream began in August 2004. 

Table 8. Analytical results of slug tests in 

wells at the Bent Creek research station, North 

Carolina.

Well 

number

Screened/Open 

interval

(feet below 

land surface)

Averagea

hydraulic 

conductivity

(feet per day)

Regolith wells

MW-1S 8–22 30

MW-2S 5–20 3

MW-3S 15–30 0.5

MW-4S 7–22 2

MW-5S 9–24 2

Transition-zone wells

MW-1I 38–53 10

MW-2I 21–36 5

MW-3I 35–50 5

MW-5I 32–47 10

Bedrock wells

MW-3D 61–300 0.04

MW-4D 61–501 0.2

a

Calculated from falling-head and rising-head slug 

tests.

Bent Creek Research Station  95
Figure 80. The water chemistry 

of samples from (A) regolith and 

transition-zone wells and surfacewater sites, and (B) open-borehole 

bedrock wells at the Bent Creek 

research station, North Carolina.

Figure 80. Piper diagrams showing the water chemistry of samples from the (A) regolith and

the surface-water site and (B) open-borehole bedrock wells at the Bent Creek research

station, North Carolina. 

MW-1D

MW-2D

MW-3D

MW-4D

MW-5D

MW-7D

EXPLANATION

MW-1S

MW-3S

MW-4S

MW-5S

MW-7I

EXPLANATION

80

100

60

40

20

0

80

60

40

20

0

SULFATE PLUS CHLORIDE PLUS NITRATE

80

100

60

40

20

20

0

40

60

80

0 100 100

60 40 20

CALCIUM

CATIONS

100 80 0

20

40

60

80

100

20

40

60

80

0

20

40

60

80

MAGNESIUM

SODIUM PLUS POTASSIUM

40 60 80

CHLORIDE PLUS NITRATE

ANIONS

200 100

60 40 20

CALCIUM

CATIONS

100 80

B.

A.

0 40 60 80

CHLORIDE PLUS NITRATE

ANIONS

0 20 100

CARBONATE PLUS BICARBONATE

0 0

20

0

40

60

80

100 100

20

40

60

80

100

20

40

60

80

0

20

40

60

80

SODIUM PLUS POTASSIUM

CARBONATE PLUS BICARBONATE

80

100

60

40

20

0

SULFATE

80

100

60

40

20

0

MAGNESIUM

80

100

60

40

20

0

SULFATE

CALCIUM PLUS MAGNESIUM 

80

100

60

40

20

80

60

40

20 SULFATE PLUS CHLORIDE PLUS NITRATE

CALCIUM PLUS MAGNESIUM 

MW-3I

4/22/03

4/22/03

4/22/03

4/23/03

4/23/03

4/23/03

4/21/03

4/21/03

4/21/03

4/22/03

4/23/03

4/21/03

4/21/03

4/23/03

Bent Creek 

Boyd Branch 

MW-1I

MW-2I

MW-4I

MW-5I

96  Water-Resources Data and Hydrogeologic Setting for Research Stations in the Piedmont and Blue Ridge, 2000–2004
Figure 81. Major ion milliequivalents in water samples collected from (A) regolith wells and surface-water sites, (B) transition-zone 

wells, and (C) open-borehole bedrock wells at the Bent Creek research station, North Carolina, April 2003.

0.25

A.

0.125 0 0.125 0.25 0.25 0.125 0 0.125 0.25 2 1 0 1 2

CATIONS ANIONS

Sodium Chloride

MW-1S

Calcium Bicarbonate

Magnesium Sulfate

Sodium Chloride

MW-3S

Calcium Bicarbonate

Magnesium Sulfate

Sodium Chloride

MW-4S

Calcium Bicarbonate

Magnesium Sulfate

Sodium Chloride

MW-5S

Calcium Bicarbonate

Magnesium Sulfate

Sodium Chloride

Bent Creek

Calcium Bicarbonate

Magnesium Sulfate

Sodium Chloride

Boyd Branch

Calcium Bicarbonate

Magnesium Sulfate

B. CATIONS ANIONS

Sodium Chloride

MW-1I

Calcium Bicarbonate

Magnesium Sulfate

Sodium Chloride

MW-2I

Calcium Bicarbonate

Magnesium Sulfate

Sodium Chloride

MW-3I

Calcium Bicarbonate

Magnesium Sulfate

Sodium Chloride

MW-4I

Calcium Bicarbonate

Magnesium Sulfate

Sodium Chloride

Calcium Bicarbonate

Magnesium Sulfate

Sodium Chloride

MW-7I

Calcium Bicarbonate

Magnesium Sulfate

MW-5I

Sodium Chloride

MW-1D

Calcium Bicarbonate

Magnesium Sulfate

Sodium Chloride

MW-2D

Calcium Bicarbonate

Magnesium Sulfate

Sodium Chloride

MW-3D

Calcium Bicarbonate

Magnesium Sulfate

Sodium Chloride

MW-4D

Calcium Bicarbonate

Magnesium Sulfate

Sodium Chloride

Calcium Bicarbonate

Magnesium Sulfate

Sodium Chloride

MW-7D

Calcium Bicarbonate

Magnesium Sulfate

MW-5D

C. CATIONS ANIONS

Figure 81. Stiff diagrams showing major ion milliequivalents in water samples collected from (A) the regolith wells

and surface-water site, (B) the intermediate-zone wells, and (C) the open-borehole bedrock wells at the Bent Creek

research station, North Carolina, April 2003.

MILLIEQUIVALENTS PER LITER MILLIEQUIVALENTS PER LITER MILLIEQUIVALENTS PER LITER

Calcium

Bent Creek Research Station  97
Figure 82. The range, median, and quartile statistical values for (A) pH, (B) specific 

conductance, and (C) dissolved oxygen for wells and surface-water sites during 

periodic sampling events at the Bent Creek research station, North Carolina.

BEDROCK

(2)

REGOLITH

(4)

TRANSITION

ZONE

(6)

SURFACE

WATER

(2)

7.5

7.0

6.5

6.0

5.5

5.0

4.5

pH, IN STANDARD UNITS

80

60

40

20

0

10

8

6

4

2

DISSOLVED OXYGEN, IN MILLIGRAMS PER LITER

0

(2) Number of samples

Upper detached

EXPLANATION

Lower detached

Upper adjacent

Lower adjacent

Median

75th percentile

25th percentile

A.

B.

C.

SPECIFIC CONDUCTANCE, IN MICROSIEMENS PER

CENTIMETER AT 25 DEGREES CELSIUS

Figure 82. The range, median, and

quartile statistical values for (A) pH, 

(B) specific conductance, and

(C) dissolved oxygen for wells and the

surface-water sites during periodic

sampling events at the Bent Creek

research station, North Carolina.

Interquartile range (IQR):

adjacent data are within

1.5 times the IQR, while

detached data are outliers.

98  Water-Resources Data and Hydrogeologic Setting for Research Stations in the Piedmont and Blue Ridge, 2000–2004
Figure 83. The range, median, and quartile statistical values for (A) calcium, 

(B) magnesium, and (C) sodium for wells and surface-water sites during 

periodic sampling events at the Bent Creek research station, North Carolina.

BEDROCK

(2)

REGOLITH

(4)

TRANSITION

ZONE

(6)

SURFACE

WATER

(2)

8

6

4

2

0

CALCIUM, IN MILLIGRAMS PER LITER MAGNESIUM, IN MILLIGRAMS PER LITER

1.4

1.2

1.0

0.8

0.6

0.4

6

5

4

3

2

1

0

SODIUM, IN MILLIGRAMS PER LITER

Upper detached

EXPLANATION

Lower detached

Upper adjacent

Lower adjacent

Median

75th percentile

25th percentile

A.

B.

C.

Figure 83. The range, median, and

quartile statistical values for (A) calcium, 

(B) magnesium, and (C) sodium for 

wells and the surface-water sites during

periodic sampling events at the Bent Creek

research station, North Carolina.

(2) Number of samples

Interquartile range (IQR):

adjacent data are within

1.5 times the IQR, while

detached data are outliers.

Bent Creek Research Station  99
Figure 84. The range, median, and quartile statistical values for (A) bicarbonate, 

(B) chloride, and (C) sulfate for wells and surface-water sites during periodic 

sampling events at the Bent Creek research station, North Carolina.

BEDROCK

(2)

TRANSITION

ZONE

(6)

SURFACE

WATER

(2)

REGOLITH

(4)

50

40

30

20

10

0

BICARBONATE, IN MILLIGRAMS PER LITER 

2.5

2.0

1.5

1.0

0.5

0

CHLORIDE, IN MILLIGRAMS PER LITER

8

6

4

2

0

SULFATE, IN MILLIGRAMS PER LITER

Upper detached

EXPLANATION

Lower detached

Upper adjacent

Lower adjacent

Median

75th percentile

25th percentile

A.

B.

C.

Figure 84. The range, median, and

quartile statistical values for 

(A) bicarbonate, (B) chloride, and

(C) sulfate for wells and the

surface-water sites during periodic

sampling events at the Bent Creek

research station, North Carolina.

(2) Number of samples

Interquartile range (IQR):

adjacent data are within

1.5 times the IQR, while

detached data are outliers.

100 Water-Resources Data and Hydrogeologic Setting for Research Stations in the Piedmont and Blue Ridge, 2000–2004
Summary

In 1999, the U.S. Geological Survey and the North 

Carolina Department of Environment and Natural Resources, 

Division of Water Quality, began a multiyear cooperative 

study to measure ambient ground-water quality and 

characterize the ground-water-flow system in the Piedmont 

and Blue Ridge Physiographic Provinces of North Carolina. 

To date (2006), data have been collected from 160 wells at six 

research stations. Data presented in this report include regional 

surficial geology, research-station design, well characteristics, 

borehole geophysical data, ground-water-quality data, and 

ground-water-level data from four stations (110 wells and 

piezometers). Data are presented for the Lake Wheeler Road 

research station (LWRRS, Raleigh) for the period April 2001 

to September 2004, for the Langtree Peninsula research 

station (LPRS, Mooresville) for the period September 2000 

to September 2004, for the Upper Piedmont research station 

(UPRS, Reidsville) for the period March 2002 to September 

2004, and for the Bent Creek research station (BCRS, 

Asheville) for the period July 2002 to September 2004. 

References

Bouwer, H. and Rice, R.C., 1976, A slug test for determining hydraulic conductivity of unconfined aquifers with 

completely or partially penetrating wells: Water Resources 

Research v. 12, no. 3, p. 423–428.

Butler, J.J., Jr., 1998, The design, performance, and analysis of 

slug tests: Boca Raton, FL, Lewis Publishers, 251 p. 

Chapman, M.J., Bolich, R.E., and Huffman, B.A., 2005, 

Hydrogeologic setting, ground-water flow, and groundwater quality at the Lake Wheeler Road research station, 

2001–03, North Carolina Piedmont and Blue Ridge Mountains Resource Evaluation Program: U.S. Geological Survey 

Scientific Investigations Report 2005–5166, 85 p.

Daniel, C.C., III, and Dahlen, P.R., 2002, Preliminary hydrogeologic assessment and study plan for a regional groundwater resource investigation of the Blue Ridge and Piedmont Provinces of North Carolina: U.S. Geological Survey 

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