GROUND-WATER GROUND-WATER AVAILABILITYAVAILABILITY

Planning for Sustainable Planning for Sustainable Future Water Supplies South Future Water Supplies South

of the C&D Canalof the C&D Canal

Delaware Geological Survey – January 2007

OVERVIEWOVERVIEW

CONCEPTS CONCEPTS HISTORICAL PERSPECTIVEHISTORICAL PERSPECTIVE CURRENT STATUSCURRENT STATUS PLANNING FOR THE FUTUREPLANNING FOR THE FUTURE

Delaware Geological Survey – January 2007

MAJOR CONCEPTSMAJOR CONCEPTS

Ground water is the only Ground water is the only naturally occurring source for naturally occurring source for fresh potable waterfresh potable water

Desalinization is very expensiveDesalinization is very expensive Surface water is not an optionSurface water is not an option

Delaware Geological Survey – January 2007

MAJOR CONCEPTSMAJOR CONCEPTS GW can not be directly observedGW can not be directly observed Aquifers supply water to wellsAquifers supply water to wells GW is connected to SWGW is connected to SW Coastal Plain geology controls Q&QCoastal Plain geology controls Q&Q There is a lot of water, butThere is a lot of water, but

not always where we need itnot always where we need it not of the right chemical qualitynot of the right chemical quality

““Sustainability” is a time-relative Sustainability” is a time-relative value judgementvalue judgement

Delaware Geological Survey – January 2007

MAJOR CONCEPTSMAJOR CONCEPTS There is a lot of good information available, There is a lot of good information available,

but but not always where we need it not always where we need it of the right typeof the right type

Increased demand for aquifers to be used for Increased demand for aquifers to be used for wastewater and stormwater disposal, and ASRwastewater and stormwater disposal, and ASR

Reliable estimates of availability use all Reliable estimates of availability use all available data in an appropriate model and available data in an appropriate model and are presented as a range of valuesare presented as a range of values

Delaware Geological Survey – January 2007

HISTORICAL PERSPECTIVE OF HISTORICAL PERSPECTIVE OF GROUND-WATER AVAILABILITY GROUND-WATER AVAILABILITY

STUDIES 1950’s – 1960’s STUDIES 1950’s – 1960’s Simple water budgets Simple water budgets Analytic equations with gross Analytic equations with gross

assumptionsassumptions Regional scaleRegional scale Limited data – few dozen to few Limited data – few dozen to few

hundred observation pointshundred observation points Identification of aquifer/geologic units Identification of aquifer/geologic units

hampered by lack of datahampered by lack of dataDelaware Geological Survey – January 2007

HISTORICAL PERSPECTIVE OF HISTORICAL PERSPECTIVE OF GROUND-WATER STUDIES GROUND-WATER STUDIES

1970’s – 1990’s1970’s – 1990’s Availability determined from simple Availability determined from simple

water budget and analytic modelswater budget and analytic models A few more complex numerical A few more complex numerical

models of limited areal scope were models of limited areal scope were constructedconstructed

Local to regional studiesLocal to regional studies Focused data collection by topic or Focused data collection by topic or

geographygeography Most aquifer units identified with Most aquifer units identified with

modern data and terminologymodern data and terminology

HISTORICAL PERSPECTIVE OF HISTORICAL PERSPECTIVE OF GROUND-WATER STUDIESGROUND-WATER STUDIES

2000 to present 2000 to present Local to regional studiesLocal to regional studies More complex numerical models for More complex numerical models for

specific problemsspecific problems Multiple large datasets of Multiple large datasets of

hydrogeologic conditions and hydrogeologic conditions and infrastructureinfrastructure

Focus of projects is to provide Focus of projects is to provide numerical data suitable for use in numerical data suitable for use in detailed ground-water flow modelsdetailed ground-water flow models

Identify where aquifers are connectedIdentify where aquifers are connectedDelaware Geological Survey – January 2007

CURRENT PROJECTSCURRENT PROJECTS Domestic well water quality – (DCC)Domestic well water quality – (DCC) Confined aquifers in KCConfined aquifers in KC Aquifer thickness in KCAquifer thickness in KC KC surficial geologic mapKC surficial geologic map Database development and upgradesDatabase development and upgrades USACE steady state model of NNCCUSACE steady state model of NNCC TMDL effortsTMDL efforts

Delaware Geological Survey – January 2007

WHERE WE ARE GOINGWHERE WE ARE GOING

Many cooperators Many cooperators SNCC confined aquifersSNCC confined aquifers Automation of gw, sw, and climate Automation of gw, sw, and climate

measurementsmeasurements KC transmissivityKC transmissivity SC confined aquifers …..SC confined aquifers ….. SC surficial geologic mapSC surficial geologic map

Delaware Geological Survey – January 2007

Middletown

WF 2

C&D Canal

0 5Scale

In miles

Unconfined +Mt. Laurel aq.

Unconfined +Rancocas aq.

Unconfined +Mt. Laurel

Unconfined, Mt. Laurel + Rancocas aq

Keyground-waterrechargeareas arelocated whereaquifer units intersect theunconfined aquifer -SNCCoexample

Delaware Geological Survey – January 2007

Delaware Geological Survey – January 2007

Hydraulics of Unconfined Aquifer and Hydraulics of Unconfined Aquifer and intersection with Manokin Aquifer – intersection with Manokin Aquifer –

Sussex Co.Sussex Co.

Top of Manokin aquifer

Base and transmissivity of unconfined aquifer

N

Delaware Geological Survey – January 2007

MOVING TO SOLVE MOVING TO SOLVE PRIORITY PROBLEMS:PRIORITY PROBLEMS:

THE TWO QsTHE TWO Qs

QUANTITYQUANTITY Poorly constrained Poorly constrained

estimates of gw estimates of gw availabilityavailability

Streamflow Streamflow depletiondepletion

Wastewater, Wastewater, stormwater, and ASRstormwater, and ASR

Declining gw levels Declining gw levels in confined aquifersin confined aquifers

QUALITYQUALITY Widespread Widespread

contaminationcontamination SW impacts of gw SW impacts of gw

contaminationcontamination Wastewater, Wastewater,

stormwater, and stormwater, and ASRASR

Q available <> Q sustainable ??

Delaware Geological Survey – January 2007

NEEDS FOR NEEDS FOR WATER SUPPLY PLANNINGWATER SUPPLY PLANNING

Better tools and information to more Better tools and information to more effectively manage and plan ……effectively manage and plan ……

Basic data measurements – levels, Basic data measurements – levels, flow, hydraulics, and chemistryflow, hydraulics, and chemistry

Improved pumping dataImproved pumping data Numerical flow simulation based Numerical flow simulation based

estimates – steady state then estimates – steady state then transienttransient

10 year life cycle of model tools10 year life cycle of model toolsDelaware Geological Survey – January 2007

SUSTAINABLE DEVELOPMENT SUSTAINABLE DEVELOPMENT STUDY COMPONENTSSTUDY COMPONENTS

Aquifer characterization (geometry& Aquifer characterization (geometry& hydraulics)hydraulics)

GW levels, stream discharge (localized)GW levels, stream discharge (localized) Characterize water use at appropriate Characterize water use at appropriate

time scales (pumping and disposal)time scales (pumping and disposal) Linkage to SW models and TMDL issuesLinkage to SW models and TMDL issues

Delaware Geological Survey – January 2007

RIBS/Stormwater/ASRRIBS/Stormwater/ASRStudy ComponentsStudy Components

Phased investigationPhased investigation Pre-treatmentPre-treatment Hydraulics and modelingHydraulics and modeling Field performanceField performance Geochemistry/Contaminant transportGeochemistry/Contaminant transport Stream/well impactsStream/well impacts

Delaware Geological Survey – January 2007

WHAT ELSE IS NEEDED FOR PLANNING WHAT ELSE IS NEEDED FOR PLANNING ??

DISCUSS PRIORITY AREAS AND DISCUSS PRIORITY AREAS AND DEVELOP A WORK PLAN AND DEVELOP A WORK PLAN AND

SCHEDULESCHEDULE Southern NCC/Northern KC Southern NCC/Northern KC Eastern SCEastern SC Central to southern KCCentral to southern KC Northern NCCNorthern NCC Western SCWestern SC Impact of wastewater on water Impact of wastewater on water

supplysupply

Delaware Geological Survey – January 2007

EXPLORATIONEXPLORATIONSTUDY COMPONENTSSTUDY COMPONENTS

Test drilling and lithologic Test drilling and lithologic characterization of geologic unitscharacterization of geologic units

Multi-level wells and characterization of Multi-level wells and characterization of hydraulic and chemical properties of hydraulic and chemical properties of aquifers (Spatial distribution of 10,000 aquifers (Spatial distribution of 10,000 mg/L TDS in Potomac aquifers in SNCC mg/L TDS in Potomac aquifers in SNCC and NKCo; Cheswold and deeper in ESC)and NKCo; Cheswold and deeper in ESC)

Depths > 2500 ftDepths > 2500 ft

Delaware Geological Survey – January 2007