A Roadmap for the Scientific AssessmentA Roadmap for the Scientific Assessmentof Maryland’s Coastal Plain Groundwaterof Maryland’s Coastal Plain Groundwater

ResourcesResources

David W. BoltonMaryland Geological Survey

Robert J. ShedlockU.S. Geological Survey

James M. GerhartU.S. Geological Survey

Emery T. CleavesMaryland Geological Survey

Why a Comprehensive Assessment?

• Better evaluation of cumulative withdrawals on regionalpotentiometric surface

• Current data often fragmented, in many locations• Ground-water “management levels” exceeded in some

areas• MDE needs comprehensive management tools that will

help them allocate ground water in a scientifically soundmanner, in a regional context

Declining Water Levels inSouthern Maryland

SM Df 71Aquia Formation

1975 1980 1985 1990 1995 2000 2005

WA

TE

RLE

VE

L(F

EE

TB

ELO

WL

AN

DS

UR

FA

CE

)

100

120

140

160

180

200

220

Well location

Science Plan for the Management ofScience Plan for the Management ofMaryland’s Coastal Plain AquifersMaryland’s Coastal Plain Aquifers

• Purpose:To provide a comprehensive “road map” that willguide the activities necessary for the development ofappropriate groundwater management tools

• Principal contributors:– U.S. Geological Survey– Maryland Geological Survey– Maryland Department of the Environment

• Science Plan to be completed in Spring 2006

ApproximateExtent of

Study Area

MarylandCoastal Plain

AquiferSystemStudy

Science Plan GoalsScience Plan Goals

•• Hydrogeologic framework and aquifer propertiesHydrogeologic framework and aquifer properties

•• Regional groundwater flow system and waterRegional groundwater flow system and waterbudgetbudget

•• Groundwater qualityGroundwater quality

•• Enhancement of monitor networksEnhancement of monitor networks

•• Management tools for groundwater allocationManagement tools for groundwater allocation

Science Goal 1:Science Goal 1:Hydrogeologic Framework andHydrogeologic Framework and

Aquifer PropertiesAquifer Properties

•• Geometry of aquifers and confining units, includingGeometry of aquifers and confining units, includingthicknesses andthicknesses and arealareal extentsextents

•• Distribution of aquifer and confiningDistribution of aquifer and confining--unit hydraulicunit hydraulicpropertiesproperties

•• Good start on this from past work, but gaps stillGood start on this from past work, but gaps stillexist, and new data and new concepts are availableexist, and new data and new concepts are availablenownow

ConsolidatedRock

Fall Line

ChesapeakeBay

AtlanticOcean

Not to scale

SurficialAquifer

Columbia

ChesapeakeGroup

Piney Point

AquiaMagothyPatapsco

Patuxent

Confining Unit

FRESHWATER

SALTWATER

Maryland’s Major Coastal Plain Aquifers

Science Goal 2: Regional GroundScience Goal 2: Regional Ground--WaterWaterFlow System and Water BudgetFlow System and Water Budget

•• GroundGround--water flow directions and velocitieswater flow directions and velocities

•• Sources and sinks of ground water for each majorSources and sinks of ground water for each majoraquifer, and how they change withaquifer, and how they change with pumpagepumpage

•• Recharge and leakage studiesRecharge and leakage studies

•• PumpagePumpage data managementdata management

•• Regional ground water flow model, with local gridRegional ground water flow model, with local gridrefinements and optimization capabilityrefinements and optimization capability

GroundGround--Water Flow SystemWater Flow System

Ground-Water Flow Model

NestedModels atDifferentScales

Science Goal 3: Water Quality inScience Goal 3: Water Quality inthe Major Coastal Plain Aquifersthe Major Coastal Plain Aquifers

• Need– Suitability for water use– Delineation of contaminated areas– Data in different databases, formats

• Proposed study activities– Map distribution of regulated constituents– Assess potential for saltwater/brackish water intrusion– Develop conceptual framework for geochemical

evolution– Evaluate water-quality monitoring needs

Regional groundwater quality issues

Radon

Radium

Arsenic

Brackish-waterintrusion

Science Goal 4: Enhancement ofScience Goal 4: Enhancement ofMonitoring NetworksMonitoring Networks

•• GroundGround--water levels in surficial and confinedwater levels in surficial and confinedaquifersaquifers

•• Streamflow in surficial aquiferStreamflow in surficial aquifer

•• Water quality in major aquifersWater quality in major aquifers

Important for tracking trends and for calibrating modelsImportant for tracking trends and for calibrating models

Monitoring networks good in certain areas and aquifers, butMonitoring networks good in certain areas and aquifers, butespecially weak on Eastern Shoreespecially weak on Eastern Shore

Science Goal 5: Management Tools forScience Goal 5: Management Tools forGroundGround--Water AllocationWater Allocation

• Web-Based Aquifer Information System

• Ground-water flow models at different scales

• Optimization models at local/subregional scales

• Solute-transport models for selected quality issues

• Decision-support system to integrate data and modelsinto web-based GIS format that can be queried toevaluate ground-water development options

• Relevant State policies• Ground-water permits• Allocation processes• Development plans• Appropriations

• Ground-water levels• Streamflow• Pumpage• Water quality• Geophysical logs

• Ground-water flow• Optimization• Solute transport

• Aquifer tests• Recharge estimates• Ground-water/surface-

water interactions• Water budgets

WebWeb--BasedBasedUserUser

InterfaceInterface

Information Hydrologic Data

Hydrologic Models Hydrologic Analyses

Coastal Plain Aquifer Information System

General Approach for Optimization Modeling

Implementation Plans

Develop optimizationmodel

Determine managementcriteria

Link flow andoptimization models tocreate managementmodel

Test water-managementscenarios

Inform partners andstakeholders

Develop and test ground-water computer flow model

Simulate flow system andconduct field studies ofrecharge and leakage

Enhance ground-water andstreamflow monitoringnetworks

Conduct water-qualitystudies

Develop an aquiferinformation system

Refine the aquifer framework

Identify information gaps

Develop plans for addressinggaps

Build partnerships and informpublic

Phase III, 2010-2013Using the Tools to

Manage and Optimizethe Resource

Phase II, 2008-2012Filling in the Gaps andBuilding the Resource

Management Tools

Phase I, 2006-2008Getting Started and Building

Partnerships