GROUND-WATER AVAILABILITY Planning for Sustainable Future Water Supplies South of the C&D Canal Delaware Geological Survey – January 2007

OVERVIEW CONCEPTS CONCEPTS HISTORICAL PERSPECTIVE HISTORICAL PERSPECTIVE CURRENT STATUS CURRENT STATUS PLANNING FOR THE FUTURE PLANNING FOR THE FUTURE Delaware Geological Survey – January 2007

MAJOR CONCEPTS Ground water is the only naturally occurring source for fresh potable water Ground water is the only naturally occurring source for fresh potable water Desalinization is very expensive Desalinization is very expensive Surface water is not an option Surface water is not an option Delaware Geological Survey – January 2007

MAJOR CONCEPTS GW can not be directly observed GW can not be directly observed Aquifers supply water to wells Aquifers supply water to wells GW is connected to SW GW is connected to SW Coastal Plain geology controls Q&Q Coastal Plain geology controls Q&Q There is a lot of water, but There is a lot of water, but not always where we need it not always where we need it not of the right chemical quality not of the right chemical quality “Sustainability” is a time-relative value judgement “Sustainability” is a time-relative value judgement Delaware Geological Survey – January 2007

MAJOR CONCEPTS There is a lot of good information available, but There is a lot of good information available, but not always where we need it not always where we need it of the right type of the right type Increased demand for aquifers to be used for wastewater and stormwater disposal, and ASR Increased demand for aquifers to be used for wastewater and stormwater disposal, and ASR Reliable estimates of availability use all available data in an appropriate model and are presented as a range of values Reliable estimates of availability use all available data in an appropriate model and are presented as a range of values Delaware Geological Survey – January 2007

HISTORICAL PERSPECTIVE OF GROUND-WATER AVAILABILITY STUDIES 1950’s – 1960’s Simple water budgets Simple water budgets Analytic equations with gross assumptions Analytic equations with gross assumptions Regional scale Regional scale Limited data – few dozen to few hundred observation points Limited data – few dozen to few hundred observation points Identification of aquifer/geologic units hampered by lack of data Identification of aquifer/geologic units hampered by lack of data Delaware Geological Survey – January 2007

HISTORICAL PERSPECTIVE OF GROUND-WATER STUDIES 1970’s – 1990’s Availability determined from simple water budget and analytic models Availability determined from simple water budget and analytic models A few more complex numerical models of limited areal scope were constructed A few more complex numerical models of limited areal scope were constructed Local to regional studies Local to regional studies Focused data collection by topic or geography Focused data collection by topic or geography Most aquifer units identified with modern data and terminology Most aquifer units identified with modern data and terminology

HISTORICAL PERSPECTIVE OF GROUND-WATER STUDIES 2000 to present Local to regional studies Local to regional studies More complex numerical models for specific problems More complex numerical models for specific problems Multiple large datasets of hydrogeologic conditions and infrastructure Multiple large datasets of hydrogeologic conditions and infrastructure Focus of projects is to provide numerical data suitable for use in detailed ground- water flow models Focus of projects is to provide numerical data suitable for use in detailed ground- water flow models Identify where aquifers are connected Identify where aquifers are connected Delaware Geological Survey – January 2007

CURRENT PROJECTS Domestic well water quality – (DCC) Domestic well water quality – (DCC) Confined aquifers in KC Confined aquifers in KC Aquifer thickness in KC Aquifer thickness in KC KC surficial geologic map KC surficial geologic map Database development and upgrades Database development and upgrades USACE steady state model of NNCC USACE steady state model of NNCC TMDL efforts TMDL efforts Delaware Geological Survey – January 2007

WHERE WE ARE GOING Many cooperators Many cooperators SNCC confined aquifers SNCC confined aquifers Automation of gw, sw, and climate measurements Automation of gw, sw, and climate measurements KC transmissivity KC transmissivity SC confined aquifers ….. SC confined aquifers ….. SC surficial geologic map SC surficial geologic map Delaware Geological Survey – January 2007

Middletown WF 2 C&D Canal 0 5 Scale In miles Unconfined + Mt. Laurel aq. Unconfined + Rancocas aq. Unconfined + Mt. Laurel Unconfined, Mt. Laurel + Rancocas aq Key ground-water recharge areas are located where aquifer units intersect the unconfined aquifer - SNCCo example Delaware Geological Survey – January 2007

Hydraulics of Unconfined Aquifer and intersection with Manokin Aquifer – Sussex Co. Top of Manokin aquifer Base and transmissivity of unconfined aquifer N Delaware Geological Survey – January 2007

MOVING TO SOLVE PRIORITY PROBLEMS: THE TWO Qs QUANTITY QUANTITY Poorly constrained estimates of gw availability Poorly constrained estimates of gw availability Streamflow depletion Streamflow depletion Wastewater, stormwater, and ASR Wastewater, stormwater, and ASR Declining gw levels in confined aquifers Declining gw levels in confined aquifers QUALITY QUALITY Widespread contamination Widespread contamination SW impacts of gw contamination SW impacts of gw contamination Wastewater, stormwater, and ASR Wastewater, stormwater, and ASR Q available <> Q sustainable ?? Delaware Geological Survey – January 2007

NEEDS FOR WATER SUPPLY PLANNING Better tools and information to more effectively manage and plan …… Better tools and information to more effectively manage and plan …… Basic data measurements – levels, flow, hydraulics, and chemistry Basic data measurements – levels, flow, hydraulics, and chemistry Improved pumping data Improved pumping data Numerical flow simulation based estimates – steady state then transient Numerical flow simulation based estimates – steady state then transient 10 year life cycle of model tools 10 year life cycle of model tools Delaware Geological Survey – January 2007

SUSTAINABLE DEVELOPMENT STUDY COMPONENTS Aquifer characterization (geometry& hydraulics) Aquifer characterization (geometry& hydraulics) GW levels, stream discharge (localized) GW levels, stream discharge (localized) Characterize water use at appropriate time scales (pumping and disposal) Characterize water use at appropriate time scales (pumping and disposal) Linkage to SW models and TMDL issues Linkage to SW models and TMDL issues Delaware Geological Survey – January 2007

RIBS/Stormwater/ASR Study Components Phased investigation Phased investigation Pre-treatment Pre-treatment Hydraulics and modeling Hydraulics and modeling Field performance Field performance Geochemistry/Contaminant transport Geochemistry/Contaminant transport Stream/well impacts Stream/well impacts Delaware Geological Survey – January 2007

WHAT ELSE IS NEEDED FOR PLANNING ? DISCUSS PRIORITY AREAS AND DEVELOP A WORK PLAN AND SCHEDULE Southern NCC/Northern KC Southern NCC/Northern KC Eastern SC Eastern SC Central to southern KC Central to southern KC Northern NCC Northern NCC Western SC Western SC Impact of wastewater on water supply Impact of wastewater on water supply Delaware Geological Survey – January 2007

EXPLORATION STUDY COMPONENTS Test drilling and lithologic characterization of geologic units Test drilling and lithologic characterization of geologic units Multi-level wells and characterization of hydraulic and chemical properties of aquifers (Spatial distribution of 10,000 mg/L TDS in Potomac aquifers in SNCC and NKCo; Cheswold and deeper in ESC) Multi-level wells and characterization of hydraulic and chemical properties of aquifers (Spatial distribution of 10,000 mg/L TDS in Potomac aquifers in SNCC and NKCo; Cheswold and deeper in ESC) Depths > 2500 ft Depths > 2500 ft Delaware Geological Survey – January 2007