McGinty, Angela L. - UMBC

155 Pages·2003·4.24 MB·English

Geostatistical Analysis of the Impacts of Urbanization on Spring Water Quality

in Valley Creek Watershed, Chester County, Pennsylvania

A Thesis

Submitted to the Faculty

of

Drexel University

by

Angela Lea McGinty

in partial fulfillment of the

requirements for the degree

of

Master of Science in Environmental Engineering

September 2003
ii
ACKNOWLEDGMENTS

This research was accomplished with the help and support of many people in
my life. I could not have produced this body of work without their willingness to
believe in me.
I would first like to thank Dr. Claire Welty for giving me the opportunity to
work on this great project and to work with such great people. Her support and
guidance throughout the life of this project never failed. Without her dedication to
helping me find 172 springs, this endeavor could not have been undertaken.
I would also like to thank my committee members, Dr. Sue Kilham and Dr.
Weilin Huang for helping me along the way. Their flow of fresh ideas helped to
make this research truly multidisciplinary.
Much field work and lab analysis was needed in order to sample and analyze
these springs. This could not have been done without the help of the following
people: Challey Comer, Christy Wojculewski, Luanne Steffy, and Rob Ryan.
All of the people in the Watersheds group were an amazing source of help and
support in so many different ways. Thanks for making me feel like part of the team,
Dr. Claire Welty, Dr. Sue Kilham, Dr. Bob Brulle, Dr. Aaron Packman, Rob Ryan,
Luanne Steffy, Clay Emerson, and Jaclyn Dispensa. A final thanks to the National
Science Foundation for funding this project which gave me the opportunity to learn
so much and meet some amazing people.
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TABLE OF CONTENTS

LIST OF TABLES.........................................................................................................v

LIST OF FIGURES....................................................................................................vii

ABSTRACT.................................................................................................................ix

1. INTRODUCTION AND BACKGROUND..............................................................1

1.1 Valley Creek Watershed....................................................................................2

1.2 Geology and Soils..............................................................................................3

1.3 The Groundwater System..................................................................................9

1.3.1 General Features of Valley Creek Groundwater System.......................9

1.3.2 Diffuse versus Conduit Groundwater Flows in Fractured Rock
Aquifers................................................................................................11

1.3.3 Mineralogy and Groundwater Chemistry in Fractured Rock
Aquifers................................................................................................14

1.4 Land Use..........................................................................................................15

1.5 Comparison Semivariogram Study..................................................................18

1.6 Hypotheses to be Tested in MS Thesis............................................................21

1.6.1 Geostatistical Relationship Between Water Quality and Land
Use/Geology........................................................................................21

1.6.2 Shallow Versus Deep Groundwater Systems......................................23

2. METHODS AND PROCEDURES..........................................................................25

2.1 Spring Sampling Method.................................................................................25

2.2 Spring Water Analysis.....................................................................................26

2.3 Hardness Analysis............................................................................................27

2.4 Scatterplots.......................................................................................................27
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2.5 Factor Analysis................................................................................................28

2.6 Semivariogram Analysis..................................................................................29

3. RESULTS................................................................................................................35

3.1 Scatterplots.......................................................................................................35

3.2 Factor Analysis................................................................................................36

3.2 Semivariograms...............................................................................................37

3.3.1 Geology Indicator Semivariograms.....................................................38

3.3.2 Land Use Indicator Semivariograms...................................................44

3.3.3 Water Quality Semivariograms............................................................48

3.3.4 Cross-semivariograms..........................................................................49

3.4 Temperature and Hardness..............................................................................55

3.5 Temporal Spring Water Chemistry..................................................................58

4. DISCUSSION..........................................................................................................71

4.1 Scatterplots.......................................................................................................71

4.2 Semivariograms...............................................................................................71

4.3 Temperature and Hardness..............................................................................79

4.4 Temporal Spring Water Chemistry..................................................................81

5. SUMMARY.............................................................................................................87

LIST OF REFERENCES.............................................................................................90

APPENDIX A: FIELD AND LAB ANALYSIS RESULTS OF SPRINGS...............93

APPENDIX B: SCATTERPLOTS OF ION PAIRS.................................................124

APPENDIX C: E. COLI RESULTS OF TEMPORAL SPRING SAMPLING........140
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LIST OF TABLES
1. Variance-covariance matrix for spring water quality data from Valley
Creek watershed...............................................................................................35

2A. Indicator semivariogram results for geology...................................................40

2B. Indicator semivariogram results for land use...................................................45
3. Water quality semivariogram results...............................................................50
4. Water quality cross-variogram results.............................................................54
5. Geology, land use type, and waste disposal for springs sampled every six
weeks, August 2002 to July 2003....................................................................58

A1A. Field data for all springs sampled in Valley Creek watershed January
2002 to June 2002............................................................................................93

A1B. Anion analysis and alkalinity for all springs sampled in Valley Creek
watershed.........................................................................................................96

A1C. Cation analysis for all springs sampled in Valley Creek watershed
January 2002....................................................................................................99

A1D. Indicator data for all springs sampled in Valley Creek watershed
January 2002 to June 2002.............................................................................102

A2A. Field data and lab analysis results of spring 3 collected during the
period August 2002 to July 2003...................................................................105

A2B. Field data and lab analysis results of spring 13 collected during the
period August 2002 to July 2003...................................................................106

A2C. Field data and lab analysis results of spring 16 collected during the
period August 2002 to July 2003...................................................................107

A2D. Field data and lab analysis results of spring 18 collected during the
period August 2002 to July 2003...................................................................108

A2E. Field data and lab analysis results of spring 24 collected during the
period August 2002 to July 2003...................................................................109

A2F. Field data and lab analysis results of spring 33 collected during the
period August 2002 to July 2003...................................................................110
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A2G. Field data and lab analysis results of spring 50 collected during the
period August 2002 to July 2003...................................................................111

A2H. Field data and lab analysis results of spring 57 collected during the
period August 2002 to July 2003...................................................................112

A2I. Field data and lab analysis results of spring 60 collected during the
period August 2002 to July 2003...................................................................113

A2J. Field data and lab analysis results of spring 66 collected during the
period August 2002 to July 2003...................................................................114

A2K. Field data and lab analysis results of spring 75 collected during the
period August 2002 to July 2003...................................................................115

A2L. Field data and lab analysis results of spring 82 collected during the
period August 2002 to July 2003...................................................................116

A2M. Field data and lab analysis results of spring 108 collected during the
period August 2002 to July 2003...................................................................117

A2N. Field data and lab analysis results of spring 114 collected during the
period August 2002 to July 2003...................................................................118

A2O. Field data and lab analysis results of spring 118 collected during the
period August 2002 to July 2003...................................................................119

A2P. Field data and lab analysis results of spring 122 collected during the
period August 2002 to July 2003...................................................................120

A2Q. Field data and lab analysis results of spring 147 collected during the
period August 2002 to July 2003...................................................................121

A2R. Field data and lab analysis results of spring 161 collected during the
period August 2002 to July 2003...................................................................122

A2S. Field data and lab analysis results of spring 171 collected during the
period August 2002 to July 2003...................................................................123

C1. E. Coli data collected at springs on January 24 and 25, 2003.......................140

C2. E. Coli data collected at springs on March 7, 2003.......................................141

C3. E. Coli data collected at springs on April 14 and 16, 2003...........................142
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LIST OF FIGURES

1. Location of Valley Creek watershed within Chester County, PA........................3
2. Geology and faults of Valley Creek watershed....................................................5
3. Lithological strata in Valley Creek watershed (Sloto, 1990)................................6
4. Groundwater flow paths in Valley Creek watershed (Sloto, 1990)....................10
5. Springs locations in Valley Creek watershed.....................................................11

6. Diffuse and conduit flow systems (Shuster, 1970; Shuster and White, 1971)...12
7. Temperature and hardness measured in a diffuse and conduit spring over
one year (Shuster, 1970; Shuster and White, 1971)............................................14

8. Land use distribution in Valley Creek watershed...............................................16
9. Areas served by septic systems in Valley Creek watershed (East Whiteland
and Tredyffrin Townships, 2002).......................................................................18

10. Spring locations and land use of the Dyle River Basin, Belgium study
(Goovaerts et al., 1993).......................................................................................19

11. Geology of the Dyle River Basin, Belgium study (Goovaerts et al., 1993).......19

12. Springs sampled every six weeks from August 2002 to July 2003....................24
13. Illustration of lag distance, h, lag tolerance, angle tolerance, and bandwidth
(Deutsch, 2002)...................................................................................................31

14. Circle of correlation of water quality variables calculated from factor
analysis of the variance-covariance matrix.........................................................37

15. Maximum correlation angle (18º north of east) and minimum correlation
angle (108º north of east)....................................................................................39

16. Geology indicator semivariograms for Bryn Mawr, Chickies, Antietam and
Harpers, Vintage, Kinzers, Octoraro, Ledger, Conestoga, Gneiss, Elbrook,
and Stockton formations.....................................................................................41

17. Land use indicator semivariograms for Public Land, Residential,
Commercial, Industrial, Utilities, Farms, and Septic..........................................46
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18. Water quality semivariograms for alkalinity, calcium, hardness, magnesium,
pH, specific conductance, sulfate, chloride, sodium, nitrate, and phosphate.....51

19. Cross-variograms for calcium-magnesium, sodium-chloride, and nitrate-
phosphate............................................................................................................54

20. Hardness and temperature for Springs 13, 16, 50, 57, 60, 75, 82, 118, and
171, sampled August 2002 to July 2003.............................................................56

21. Anions and cations at Spring 3, 13, 16, 18, 24, 33, 50, 57, 60, 66, 75, 82,
108, 114, 118, 122, 147, 161, 171, sampled August 2002 to July 2003.............65

22. Contour plots for pH and specific conductance data..........................................73
23. Nitrate and phosphate contour plots...................................................................77
24. Foote Mineral Company location relative to faults and springs.........................83
B1. Scatterplots of ranked water quality data gathered February to May 2002......124
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ABSTRACT
Geostatistical Analysis of the Impacts of Urbanization on Spring Water Quality
In Valley Creek Watershed, Chester County, Pennsylvania
Angela Lea McGinty
Claire Welty, PhD

This thesis investigates the impacts of urbanization on the hydrology and
water quality of the springs in Valley Creek watershed near Philadelphia,
Pennsylvania. In evaluating the spatial correlation of geological and land use patterns
with spring water quality of 110 springs found within the watershed, natural versus
anthropogenic influences on spring systems were inferred. Geostatistical analysis
was used to characterize the degree of spatial correlation of the major geologic
formations, land use types, and spring water quality. Correlation scales in the
principal directions of the geologic formations were found to be up to 10,000 m with
anisotropy ratios up to 30. Correlation scales for land use were no greater than 1,500
m with anisotropy ratios up to 3.3. Semivariogram analysis of spring water quality
showed large-scale correlations ranging from 600 m to 20,000 m at 18º and 300 m to
2,200 m at 108º for alkalinity, pH, hardness, specific conductance, Ca2+, and Mg2+.
Anisotropy ratios ranged from 2.0 to 35. Small-scale correlations were found for
Na+, SO 2-, NO -, PO 3-, and Cl- correlation scales ranged from 200 m to 550 m with
4 3 4
anisotropy ratios of near 1.0. The spatial correlation structure of the distribution of
chemical species related to geology was found to be reflective of the spatial
correlation of the geologic formations, whereas the spatial correlation structure of the
distribution of chemical species related to anthropogenic activity was similar to that
of land use.
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Hardness and temperature were sampled every six weeks in nine carbonate
springs to determine whether the springs could be classified as conduit or diffuse
according to the criteria of Shuster. Based on temperature, six springs could be
classified as conduit and three springs as diffuse. Hardness did not reveal a pattern
that characterized the springs as distinctly conduit or diffuse. Nineteen springs were
sampled for many other parameters as a function of time: pH, specific conductance,
redox, flow rate, alkalinity, hardness, F-, Cl- Br-, NO -, SO 2-, PO 3-, Ca2+, Na+, Fe2+,
3 4 4
K+, and Mg2+. Some of the trends seen in the water quality data were that sodium and
chloride increased together indicating road salt inputs, nitrate levels increased in areas
with on-lot septic systems and during months of high recharge, and bromide was
found at three springs located along the major fault in a direct line with Foote Mineral
Company.