Evaluation of Groundwater Resources of Greenwich Township, Warren County, New Jersey M2 Associates Inc. 56 Country Acres Drive Hampton, New Jersey 08827 (908) 238-0827 EVALUATION OF GROUNDWATER RESOURCES OF GREENWICH TOWNSHIP, WARREN COUNTY,NEW JERSEY NOVEMBER 8, 2005 Prepared for: Greenwich Township Planning Board 321 Greenwich Street Stewartsville, New Jersey 08886 Prepared by: Matthew J. Mulhall, P.G. M2 Associates Inc. 56 Country Acres Drive Hampton, New Jersey 08827 (908) 238-0827 EVALUATION OF GROUNDWATER RESOURCES OF GREENWICH TOWNSHIP, WARREN COUNTY,NEW JERSEY TABLE OF CONTENTS INTRODUCTION............................................................................................................. 1 GEOLOGY ...................................................................................................................... 5 LOCATION ..................................................................................................................... 5 POPULATION DENSITY.................................................................................................... 6 PHYSIOGRAPHIC PROVINCE ............................................................................................ 6 TOPOGRAPHY ................................................................................................................ 6 SURFACE WATER .......................................................................................................... 7 Watersheds............................................................................................................. 7 Stream Classifications........................................................................................... 8 SOILS ......................................................................................................................... 10 BEDROCK.................................................................................................................... 13 STRUCTURE................................................................................................................. 16 Secondary Porosity ............................................................................................. 16 Faults .................................................................................................................... 17 GROUNDWATER SYSTEMS ....................................................................................... 19 STORAGE AND TRANSMISSION CAPABILITY.................................................................... 19 PRECAMBRIAN IGNEOUS AND METAMORPHIC ROCKS/HARDYSTON QUARTZITE................. 19 Location ................................................................................................................ 19 Poor Ranking........................................................................................................ 20 Fractures............................................................................................................... 21 Yields/Depths ....................................................................................................... 21 Specific Capacities .............................................................................................. 22 Summary............................................................................................................... 22 CAMBRIAN-ORDOVICIAN CARBONATE ROCKS................................................................ 23 LOCATION ................................................................................................................... 23 Fractures/Solution Openings .............................................................................. 23 Easily Contaminated............................................................................................ 23 Yields .................................................................................................................... 24 Depths................................................................................................................... 24 Specific Capacities .............................................................................................. 25 Public Community Wells ..................................................................................... 25 Summary............................................................................................................... 25 Reservoir Capacity............................................................................................... 26 HYDROGEOLOGIC ZONES ............................................................................................. 26 AQUIFER RECHARGE.................................................................................................... 27 Hydrologic Cycle.................................................................................................. 27 ii WATER BALANCE............................................................................................. 27 PRECIPITATION ................................................................................................ 29 SURFACE-WATER RUNOFF ............................................................................ 30 EVAPOTRANSPIRATION .................................................................................. 32 GROUNDWATER RUNOFF............................................................................... 33 SUMMARY ......................................................................................................... 35 Groundwater Recharge........................................................................................ 36 GROUNDWATER............................................................................................... 36 BASEFLOW........................................................................................................ 36 HYDROGRAPH SEPARATION.......................................................................... 37 POSTEN (1984) METHOD................................................................................. 38 7Q10/MA7CD10 ................................................................................................. 39 NJGS MODIFIED METHOD............................................................................... 40 AQUIFER VERSUS “GROUNDWATER” RECHARGE .................................................. 40 SOIL RECHARGE RATES..................................................................................... 41 Groundwater Recharge Rates............................................................................. 42 PRECAMBRIAN IGNEOUS AND METAMORPHIC ZONE ................................ 42 CAMBRIAN-ORDOVICIAN CARBONATE ROCK ZONE ................................... 43 WATER SUPPLY.......................................................................................................... 44 DEMAND ..................................................................................................................... 44 DEPENDABLE YIELD..................................................................................................... 44 Definition............................................................................................................... 44 Maintainable Yield................................................................................................ 45 Planning Threshold.............................................................................................. 47 Available Dependable Yield................................................................................. 47 CONCLUSIONS............................................................................................................ 48 REFERENCES.............................................................................................................. 55 TABLES 1. Watersheds, Subwatersheds, Streams, and Surface-Water Classifications in Greenwich Township. 2. Types, Slopes, Approximate Areas, and Septic Limitations of Soils in Greenwich Township, Warren County, New Jersey. 3. Normal Rainfall and Mean Temperature For Greenwich Township As Determined from Measurements Recorded by National Climatic Data Center. 4. Soil Recharge Calculations Made with NJDEP Model DGS02-06 for Soil Types in Greenwich Township, Warren County, New Jersey. 5. Normal and Drought Condition Recharge Rates for Hydrogeologic Zones. iii 6. Dependable Yields for Hydrogeologic Zones. 7. Recharge Volumes and Dependable Yields for Hydrogeologic Zones. FIGURES 1. Location of Greenwich Township and Warren County, New Jersey. 2. Location of Highlands Water Protection & Planning Act Zones in Greenwich Township, Warren County, New Jersey. 3. Water Purveyors and Regulated Wells in Greenwich Township, Warren County, New Jersey. 4. Watersheds in Greenwich Township, Warren County, New Jersey. 5. Subwatersheds and Stream Classifications in Greenwich Township, Warren County, New Jersey. 6. Soils Beneath Greenwich Township, Warren County, New Jersey. 7. Bedrock Geology Beneath Greenwich Township, Warren County, New Jersey. 8. Hydrogeologic Zones within Greenwich Township, Warren County, New Jersey. APPENDIX A. Summary Table of Well Record Details for Greenwich Township, Warren County, New Jersey. EVALUATION OF GROUNDWATER RESOURCES OF GREENWICH TOWNSHIP, WARREN COUNTY,NEW JERSEY INTRODUCTION Greenwich Township, Warren County, New Jersey retained M2 Associates in May 2005 to conduct an evaluation of the groundwater resources of the Township. The location of Greenwich Township and Warren County in New Jersey are shown