In cooperation with the U.S. Environmental Protection Agency Arsenic, Boron, and Fluoride Concentrations in Ground Water in and Near Diabase Intrusions, Newark Basin, Southeastern Pennsylvania NORTHAMPTON COUNTY LEHIGH COUNTY BERKS COUNTY Dela ware River BUCKS COUNTY LANCASTER COUNTY CHESTER COUNTY MONTGOMERY COUNTY Scientific Investigations Report 2006–5261 U.S. Department of the Interior U.S. Geological Survey Arsenic, Boron, and Fluoride Concentrations in Ground Water in and Near Diabase Intrusions, Newark Basin, Southeastern Pennsylvania By Lisa A. Senior and Ronald A. Sloto In cooperation with the U.S. Environmental Protection Agency Scientific Investigations Report 2006-5261 U.S. Department of the Interior U.S. Geological Survey U.S. Department of the Interior DIRK KEMPTHORNE, Secretary U.S. Geological Survey Mark D. Meyers, Director U.S. Geological Survey, Reston, Virginia: 2006 For sale by U.S. Geological Survey, Information Services Box 25286, Denver Federal Center Denver, CO 80225 For more information about the USGS and its products: Telephone: 1-888-ASK-USGS World Wide Web: http://www.usgs.gov/ Any use of trade, product, or firm names in this publication is for descriptive purposes only and does not imply endorse- ment by the U.S. Government. Although this report is in the public domain, permission must be secured from the individual copyright owners to repro- duce any copyrighted materials contained within this report. Suggested citation: Senior, L.A., and Sloto, R.A., 2006, Arsenic, boron, and fluoride in ground water in and near diabase intrusions, Newark Basin, southeastern Pennsylvania: U.S. Geological Survey Scientific Investigations Report 2006-5261, 105 p. iii Contents Abstract . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Background. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Purpose and Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Study Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Previous Investigations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Hydrogeologic Setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Geology. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Geologic Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Geologic Units. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Precambrian and Paleozoic Rocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Mesozoic Rocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Stockton Formation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Lockatong Formation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Brunswick Group . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Hammer Creek Formation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Limestone Fanglomerate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Quartzite Fanglomerate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Diabase . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Jacksonwald Basalt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Sedimentary Strata at Jacksonwald and Aspers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Effects of Thermal Metamorphism . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Mineral Deposits in the Newark Basin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Magnetite Skarn and Skarn/Replacement Deposits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Hornfels Copper Deposits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Diabase-Hosted Vein and Late-Stage Igneous Segregation Deposits . . . . . . . . . . . . . . . . . . . . . 13 Sediment-Hosted and Stratabound Replacement Deposits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Evaporites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Ground-Water System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Arsenic, Boron, and Fluoride in Ground Water . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Geochemical Controls on Arsenic, Boron, and Fluoride in Ground Water . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Review of Available Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Arsenic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Boron . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 Fluoride . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Methods of Data Collection and Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Ground-Water Sample Collection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Sample Analysis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 Summary of Ground-Water Composition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 Major Ions and Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 Trace Elements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Boron Isotopes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 iv Relation to Hydrogeologic Setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 Congo Road Area. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 Jacksonwald Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 Kibblehouse Quarry Area. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 New Hope Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 Quakertown Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 Comparison of Sampling Areas and Lithologies. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 Relation to Trace Elements and Other Chemical Constituents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 Discussion of Distribution and Hydrogeochemical Controls in Ground Water . . . . . . . . . . . . . . . . . . . . . . . . . 57 Summary and Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 References Cited . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 Appendix 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 Mines and prospects in the Newark Basin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90 Congo Road Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90 Kibblehouse Quarry Area. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93 Quakertown-Perkasie-Sellersville Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97 Northeastern Bucks County Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97 New Hope-Buckingham Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .100 Reading Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .102 v Plates Altitude and configuration of the ground-water-level surface in the vicinity of the Congo road Boron site, Berks and Montgomery Counties, Pennsylvania, July through October 2004 Figures 1-10. Maps showing: 1. Location of Newark Basin and physiographic provinces, southeastern Pennsylvania . . . . . . .3 2. Bedrock geology of the Newark Basin, southeastern Pennsylvania. . . . . . . . . . . . . . . . . . . . . . . . .6 3. Types of mineral deposits in the Newark Basin, southeastern Pennsylvania. . . . . . . . . . . . . . . 11 4. Location of wells sampled by the U.S. Geological Survey for arsenic and magnitude of dissolved arsenic concentrations in ground water in Triassic-Jurassic rocks, Newark Basin, southeastern Pennsylvania, 1973-2001 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 5. Location of wells sampled by the Pennsylvania Department of Environmental Protection for arsenic and magnitude of total arsenic concentrations in ground water in ambient ground-water quality network in Triassic-Jurassic rocks, Bucks and Montgomery Counties, Newark Basin, southeastern Pennsylvania, 1985-2001 . . . . . . . . 19 6. Location of wells sampled by the Pennsylvania Department of Environmental Protection for arsenic and magnitude of total arsenic concentrations in public drinking-water supplies relying on ground water in Triassic-Jurassic rocks, Newark Basin, southeastern Pennsylvania, 1993-2003 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 7. Location of wells sampled by the U.S. Geological Survey for boron and magnitude of dissolved boron concentrations in ground water in Triassic-Jurassic rocks, Newark Basin, southeastern Pennsylvania, 1973-2000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 8. Location of wells sampled by the U.S. Geological Survey for fluoride and magnitude of dissolved fluoride concentrations in ground water in Triassic-Jurassic rocks, Newark Basin, southeastern Pennsylvania, 1949-2002 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 9. Location of wells sampled by the Pennsylvania Department of Environmental Protection for fluoride and magnitude of total fluoride concentrations in non-fluoridated public drinking-water supplies relying on ground water in Triassic-Jurassic rocks, Newark Basin, southeastern Pennsylvania, 1993-2003 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 10. Location of study areas sampled for arsenic, boron, fluoride, and other constituents in and near diabase rocks in the Newark Basin in Berks, Montgomery, and Bucks Counties, southeastern Pennsylvania . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27 11. Piper diagram showing relative contributions of major cations and anions in water samples from (A) 46 private-supply wells and (B) 12 monitor wells in the Newark Basin, southeastern Pennsylvania, 2004-2005. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29 12-14. Graphs showing: 12. Comparison of dissolved and total concentrations of (A) arsenic and (B) boron in 46 private-supply-well and 4 monitor-well samples in the Newark Basin, southeastern Pennsylvania, February 2004 - April 2005 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 13. Comparison of dissolved and total concentrations of (A) cobalt, (B) manganese, and (C) iron in 46 private-supply well and 4 monitor-well samples in the Newark Basin, southeastern Pennsylvania, February 2004-April 2005 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33 14. Distribution of boron isotopic compositions in 40 private-supply and 12 monitor wells in the Newark Basin, southeastern Pennsylvania, February 2004 - April 2005 . . . . . . . . .37 vi 15-19. Maps showing: 15. Concentrations of dissolved arsenic and boron and boron isotopic ratios in ground water from wells sampled in the Congo Road area, Berks and Montgomery Counties, southeastern Pennsylvania, February - July 2004. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38 16. Concentrations of dissolved arsenic and boron and boron isotopic ratios in ground water from wells sampled in the Jacksonwald area, Berks County, southeastern Pennsylvania, June - August 2004. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 17. Concentrations of dissolved arsenic and boron and boron isotopic ratios in ground water from wells sampled in the Kibblehouse Quarry area, Montgomery County, southeastern Pennsylvania, September - November 2004. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 18. Concentrations of dissolved arsenic and boron and boron isotopic ratios in ground water from wells sampled in the New Hope area, Bucks County, southeastern Pennsylvania, October 2004 - April 2005 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45 19. Concentrations of dissolved arsenic and boron and boron isotopic ratios in ground water from wells sampled in the Quakertown area, Bucks County, southeastern Pennsylvania, January - April 2005 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 20-22. Boxplots showing: 20. Distribution of dissolved arsenic and boron concentrations in ground water in sampling areas in and near diabase intrusions, Newark Basin, southeastern Pennsylvania, 2004-2005 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 21. Distribution of dissolved fluoride concentrations and boron isotopic compositions in ground water in sampling areas in and near diabase intrusions, Newark Basin, southeastern Pennsylvania, 2004-2005 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50 22. Distribution of boron isotopic compositions in ground water from lithologies sampled in and near diabase intrusions, Newark Basin, southeastern Pennsylvania, 2004-2005 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51 23. Probability plots showing distribution of (A) arsenic and (B) boron concentrations in ground-water samples from 43 private-supply wells completed in diabase, hornfels, and unaltered shales in and near diabase intrusions, Newark Basin, southeastern Pennsylvania . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 24. Relation between dissolved boron concentrations and boron isotopic compositions in samples from 50 wells in four lithologies sampled in and near diabase intrusions, Newark Basin, southeastern Pennsylvania, 2004-2005 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 25-27. Graphs showing: 25. Relation between dissolved arsenic concentrations and pH in water samples from (A) 46 private-supply wells and (B) 12 monitor wells in and near diabase intrusions, Newark Basin, southeastern Pennsylvania . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 26. Relation between dissolved arsenic and boron concentrations in water samples from (A) 46 private-supply wells and (B) 12 monitor wells in and near diabase intrusions, Newark Basin, southeastern Pennsylvania . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 27. Relation between dissolved boron and chloride concentrations in water samples from 12 monitor wells and 14 private-supply wells in the Congo Road area, Berks and Montgomery Counties, Pennsylvania. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .56 Appendix 1 1-1–1-7. Maps showing: 1.1. Locations of selected mines, prospects, and mineral occurrences in the Newark Basin, Pennsylvania . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91 vii 1.2. Mines, prospects, and mineral occurrences in the Congo Road area, Berks and Montgomery Counties, Pennsylvania . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92 1.3. Mines, prospects, and mineral occurrences in the Kibblehouse quarry area, Montgomery County, Pennsylvania . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94 1.4. Mines, prospects, and mineral occurrences in the Quakertown area, Bucks County, Pennsylvania . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98 1.5. Mines, prospects, and mineral occurrences in northeastern Bucks County, Pennsylvania . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99 1.6. Mines, prospects, and mineral occurrences in the New Hope area, Bucks County, Pennsylvania. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101 1.7. Mines, prospects, and mineral occurrences near Reading, Berks County, Pennsylvania . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103 Tables 1. Summary of analyses of selected early Mesozoic copper occurrences in Pennsylvania . . . . . . . . . . 10 2. Arsenic-, boron-, and fluorine-bearing minerals identified in Newark Basin rocks, Pennsylvania. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 3. Summary of U.S. Environmental Protection Agency data on arsenic concentrations in water samples from residential wells in Newark Basin rocks at or near contamination sites, southeastern Pennsylvania. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 4. Summary of U.S. Geological Survey data on dissolved arsenic concentrations in ground water by geologic unit for Newark Basin and other rocks, southeastern Pennsylvania, 1973-2001. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 5. Summary of Pennsylvania Department of Environmental Protection data on arsenic concentrations in ambient network well-water samples by geologic unit for Newark Basin rocks, Bucks and Montgomery Counties, Pennsylvania, 1985-2001 . . . . . . . . . . . . . . . . . . . . . . . . . 16 6. Summary of Pennsylvania Department of Environmental Protection data on arsenic concentrations in water samples from public drinking-water supplies with ground-water sources by geologic unit for Newark Basin rocks, southeastern Pennsylvania, 1993-2003 . . . . . . . . . 17 7. Summary of U.S. Geological Survey data on dissolved boron concentrations in ground water by geologic unit for Newark Basin and other rocks, southeastern Pennsylvania, 1973-2000. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 8. Summary of U.S. Environmental Protection Agency data on boron concentrations in residential and industrial facility well-water samples near Congo Road, Gilbertsville Area, Montgomery County, Pennsylvania, 2000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 9. Summary of U.S. Geological Survey data on dissolved fluoride concentrations in ground water by geologic unit for Newark Basin and other rocks, southeastern Pennsylvania, 1949-2002. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 10. Summary of Pennsylvania Department of Environmental Protection data on fluoride concentrations in water samples from public drinking-water supplies with ground-water sources by geologic unit for Newark Basin rocks, southeastern Pennsylvania, 1993-2003 . . . . . . . . . 23 11. Summary of U.S. Environmental Protection Agency data on fluoride concentrations in residential and industrial facility well-water samples near Congo Road, Gilbertsville Area, Montgomery County, Pennsylvania. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 12. Minimum, maximum, and median values for selected chemical properties and concentrations of dissolved major ions and total organic carbon in ground-water samples collected from 46 private-supply wells in the Newark Basin, southeastern Pennsylvania, February 2004 - April 2005. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 viii 13. Minimum, maximum, and median values for selected chemical properties and concentrations of dissolved major ions and total organic carbon in ground-water samples collected from 12 monitor wells at an industrial facility near Congo Road in Berks and Montgomery Counties, Pennsylvania, March 2004. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 14. Minimum, median, and maximum values for dissolved and total concentrations of selected trace elements in ground-water samples collected from 46 private-supply wells in the Newark Basin, southeastern Pennsylvania, February 2004 - April 2005 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 15. Minimum, median, and maximum values for dissolved concentrations of selected trace elements in ground-water samples collected from 12 monitor wells at an industrial facility near Congo Road in Berks and Montgomery Counties, Pennsylvania, March 2004 . . . . . . . . . . . . . . . . 34 16. Boron concentration and isotopic composition of three ground-water samples in the Congo Road area. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 17. Dissolved arsenic, boron, and fluoride concentrations and boron isotopic composition of 58 well-water samples collected by USGS in the Newark Basin in transects in five study areas, southeastern Pennsylvania, February 2004-April 2005. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 18. Spearman’s rho correlations statistically significant at probability values less than 0.05 between dissolved arsenic, boron, and fluoride and other dissolved constituents and chemical properties, listed in order of decreasing significance, for ground-water samples collected by U.S. Geological Survey in 2004-2005 from 46 private-supply wells in and near diabase intrusions, Newark Basin, southeastern Pennsylvania. . . . . . . . . . . . . . . . . . 54 19. Spearman’s rho correlations statistically significant at probability values less than 0.05 between dissolved arsenic, boron, and fluoride and other dissolved constituents and chemical properties, listed in order of decreasing significance, for ground-water samples collected by U.S. Geological Survey in 2004-2005 from 12 monitor wells and 14 private-supply wells in the Congo Road area, Berks and Montgomery Counties, southeastern Pennsylvania. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 20. Spearman’s rho correlations statistically significant at probability values less than 0.05 between dissolved arsenic, boron, and fluoride and other dissolved constituents and chemical properties, listed in order of decreasing significance, for ground-water samples collected by U.S. Geological Survey in 2000 from 30 wells in Newark Basin rocks, Pennsylvania and New Jersey . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 21. Description of wells sampled by the U.S. Geological Survey, Newark Basin, southeastern Pennsylvania, February 2004 - April 2005 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64 22. Field chemical measurements and results of laboratory analysis of water samples collected from 12 monitor wells and 46 private-supply wells in and near diabase intrusions, Newark Basin, southeastern Pennsylvania, February 2004-April 2005 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 Appendix 1 1-1. Mines, prospects, and mineral occurrences in the Congo Road area, Berks and Montgomery Counties, Pennsylvania . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90 1-2. Mines, prospects, and mineral occurrences in the vicinity of the Kibblehouse quarry . . . . . . . . . . . . . .93 1-3. Selected minerals reported from the Kibblehouse quarry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .95 1-4. Mines, prospects, and mineral occurrences in the Quakertown area, Bucks County, Pennsylvania . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97 1-5. Mines, prospects, and mineral occurrences in northeastern Bucks County, Pennsylvania . . . . . . . .100 1-6. Mines, prospects, and mineral occurrences in the New Hope area, Bucks County, Pennsylvania. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 1-7. Mines, prospects, and mineral occurrences near Reading, Berks County, Pennsylvania . . . . . . . . . .102