Evaluation of Groundwater Resources of Sourland Mountain Region of Central New Jersey M2 Associates Inc. Demicco & Associates, Inc. 56 Country Acres Drive 151 Old Franklin School Rd Hampton, New Jersey 08827 Pittstown, New Jersey 08867 EVALUATION OF GROUNDWATER RESOURCES OF THE SOURLAND MOUNTAIN REGION OF CENTRAL NEW JERSEY NOVEMBER 19, 2004 Prepared for: Sourland Smart Growth Project Prepared by: Matthew J. Mulhall, P.G. M2 Associates Inc. 56 Country Acres Drive Hampton, New Jersey 08827 Peter M. Demicco, P.G. Demicco and Associates, Inc. 151 Old Franklin School Road Pittstown, New Jersey 08867 EVALUATION OF GROUNDWATER RESOURCES OF THE SOURLAND MOUNTAIN REGION OF CENTRAL NEW JERSEY TABLE OF CONTENTS INTRODUCTION............................................................................................................. 1 SOURLAND SMART GROWTH .......................................................................................... 1 GROUNDWATER ............................................................................................................. 1 HEADWATERS................................................................................................................ 1 GROUNDWATER RESOURCES.......................................................................................... 2 HYDROGEOLOGIC FRAMEWORK............................................................................... 3 LOCATION...................................................................................................................... 3 POPULATION ................................................................................................................. 4 PHYSIOGRAPHIC PROVINCE ............................................................................................ 4 SURFACE WATER .......................................................................................................... 4 Subwatersheds....................................................................................................... 4 Stream Classifications........................................................................................... 5 SOILS ........................................................................................................................... 6 GEOLOGY...................................................................................................................... 7 Mapping .................................................................................................................. 7 Bedrock................................................................................................................... 8 STOCKTON FORMATION ................................................................................... 8 LOCKATONG FORMATION................................................................................. 8 PASSAIC FORMATION ....................................................................................... 9 DIABASE.............................................................................................................. 9 STRUCTURE ..................................................................................................... 10 GROUNDWATER SYSTEMS ............................................................................................ 11 Sole Source Aquifers........................................................................................... 11 Aquifer Rankings ................................................................................................. 12 Bedrock................................................................................................................. 13 STORAGE AND TRANSMISSION ..................................................................... 13 STOCKTON FORMATION ................................................................................. 14 LOCKATONG FORMATION............................................................................... 15 PASSAIC FORMATION ..................................................................................... 17 DIABASE/HORNFELS ....................................................................................... 18 GROUNDWATER RESOURCES.................................................................................. 20 HYDROLOGIC CYCLE.................................................................................................... 20 Water Balance ...................................................................................................... 20 ii Precipitation ......................................................................................................... 21 Evapotranspiration .............................................................................................. 22 Surface-Water Runoff .......................................................................................... 23 Groundwater Runoff ............................................................................................ 24 GROUNDWATER RECHARGE ......................................................................................... 26 Groundwater......................................................................................................... 26 Streamflow from Groundwater............................................................................ 26 BASEFLOW........................................................................................................ 26 DROUGHT FLOW .............................................................................................. 27 FLOW DURATIONS ........................................................................................... 28 HYDROGRAPH SEPARATION.......................................................................... 29 POSTEN (1984) METHOD................................................................................. 30 HORDON (1987) EVALUATION......................................................................... 32 USGS STUDIES................................................................................................. 33 NJGS Modified Method........................................................................................ 35 AQUIFER VERSUS “GROUNDWATER” RECHARGE ...................................... 35 WATER SUPPLY.......................................................................................................... 38 DEMAND ..................................................................................................................... 38 Residential............................................................................................................ 38 NJDEP Permitted Withdrawals............................................................................ 38 DEPENDABLE YIELD..................................................................................................... 40 Definition............................................................................................................... 40 Drought Effects .................................................................................................... 40 STREAMFLOW .................................................................................................. 40 BASEFLOW........................................................................................................ 41 RECHARGE EFFECTS...................................................................................... 41 SUMMARY ......................................................................................................... 42 Planning Threshold.............................................................................................. 42 Water-Supply Yields ............................................................................................ 43 Dwelling Unit Densities........................................................................................ 44 Recharge Areas.................................................................................................... 45 WATER QUALITY ........................................................................................................ 46 NITRATE DILUTION ....................................................................................................... 46 Nitrate.................................................................................................................... 46 Background Concentrations ............................................................................... 47 ANTIDEGRADATION LIMIT............................................................................... 47 Trela-Douglas Model............................................................................................ 48 ACCEPTANCE................................................................................................... 48 ASSUMPTIONS ................................................................................................. 49 EQUATION......................................................................................................... 50 iii CONCLUSIONS............................................................................................................ 51 REFERENCES.............................................................................................................. 58 TABLES 1. Soils beneath the Sourland Mountain Region in New Jersey. 2. Geologic Formations beneath the Sourland Mountain Region in New Jersey. 3. Normal Rainfall and Mean Temperature As Determined from Measurements Recorded by National