groundwater occurrence & movementgroundwater occurrence & movement: an introductory...
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Groundwater Occurrence & Movement:Groundwater Occurrence & Movement:An Introductory Discussion with Application to An Introductory Discussion with Application to
Northeastern IllinoisNortheastern Illinois
H. Allen Wehrmann, P.E., DirectorCenter for Groundwater Science
Illinois State Water Survey
April 24, 2007
AcknowledgmentsAcknowledgments
Martin Jaffe, University of Illinois, ChicagoMartin Jaffe, University of Illinois, ChicagoScott Meyer, Center for GW Science, ISWSScott Meyer, Center for GW Science, ISWSSteve Burch, Center for GW Science, ISWSSteve Burch, Center for GW Science, ISWSIL State Geological SurveyIL State Geological SurveyKane County Water Resources DepartmentKane County Water Resources Department
Topical Presentation OutlineTopical Presentation OutlineBasic Concepts and DefinitionsBasic Concepts and Definitions
The Hydrologic CycleThe Hydrologic CycleWhat is groundwater?What is groundwater?
Concepts & DefinitionsConcepts & DefinitionsPorous Flow vs. Fractured FlowPorous Flow vs. Fractured FlowAquifers vs. Aquifers vs. AquitardsAquitardsArtesian vs. Water Table ConditionsArtesian vs. Water Table Conditions
Regional Groundwater Flow SystemsRegional Groundwater Flow SystemsWell & Aquifer HydraulicsWell & Aquifer HydraulicsGroundwater ModelingGroundwater Modeling
The Hydrologic CycleClimate, surface water, and groundwater are linked
Porous SystemsPorous Systems
Groundwater flows throughpore spaces between grains
Porosity & Effective Porosity RangesPorosity & Effective Porosity Ranges
0.5 0.5 –– 10105 5 -- 1515SandstoneSandstone
0.5 0.5 –– 551 1 -- 1010ShaleShale
0.1 0.1 –– 555 5 -- 1515Limestone/dolomiteLimestone/dolomite
10 10 -- 555524 24 –– 5555Sand/GravelSand/Gravel
0.1 0.1 –– 101034 34 -- 6060ClayClay
0.1 0.1 –– 101034 34 -- 6161SiltSilt
EffEff. Porosity . Porosity (%)(%)
Porosity Porosity (%)(%)MaterialMaterial
Fractured SystemsFractured Systems
FracturedLimestone
or Dolomite
Aquifers vs. Aquifers vs. AquitardsAquitards
An aquifer is a saturated bed, formation, or group of formations which yields water in sufficient quantityto be of consequence as a source of supply.
An aquitard yields inappreciable quantities of water to wells compared to an aquifer but through whichleakage of water is possible. Aquitards often act as confining beds.
Unconfined vs. Confined GroundwaterUnconfined vs. Confined Groundwater
An unconfined aquifer is one in which groundwaterpossesses a free surface open to the atmosphere.The upper surface of the zone of saturation is calledthe water table.
A confined aquifer is one in which groundwater isconfined under pressure by overlying and underlyingaquitards or aquicludes and water levels in wells riseabove the top of the aquifer. Also called an artesianaquifer.
Land Surface
UnconfinedAquifer
Water Table
Bedrock
Unsaturated (Vadose) Zone
Saturated Zone
Unconfined Aquifers
Land Surface
Unconfined Aquifer
Water Table
Bedrock
Unsaturated (Vadose) Zone
Saturated Zone
Confined Aquifer
Confining Layer - AquitardPotentiometric Surface
Confined Aquifers
Confined Aquifers & Artesian WellsConfined Aquifers & Artesian Wells
Land surface
Aquifer
Water table
Flowing artesian well
Regional Groundwater Flow SystemsRegional Groundwater Flow Systems
200’
100’
20 miles
10’
0.1 mile
20’
Depth0’
Groundwater – Stream Interaction
Regional Flow Systems
Groundwater – Stream Interaction
Regional Flow Systems
Groundwater – Stream Interaction
Regional Flow Systems
Groundwater – Stream Interaction
Regional Flow Systems
Groundwater Flow VelocitiesGroundwater Flow Velocities
10 10 –– 10001000’’s feet per s feet per dayday
Highly fractured Highly fractured limestonelimestone
< 0.5 feet per day< 0.5 feet per daySandstoneSandstone
< 0.1 feet per day< 0.1 feet per dayClayClay
0.1 0.1 –– 0.5 feet per 0.5 feet per daydayClayey sandClayey sand
1 1 –– 5 feet per day5 feet per dayClean sandClean sand
55--10 feet per day10 feet per dayGravelGravel
VelocityVelocityMaterialMaterial
IL GeologyIL Geology––glacial glacial
materialsmaterials
Glacial depositional processesGlacial depositional processes
Regional Bedrock TopographyRegional Bedrock Topography
Green= higher elevations; Light violet= lower elevations
Major Sand &Gravel Aquifers
Withdrawals from Sand and Gravel Aquifers
Total use ~ 350 mgd+ ~200 mgd for irrigation
Aquifers of Northeastern IllinoisAquifers of Northeastern Illinois
Unconsolidated Aquifer System
Shallow Bedrock Aquifer
Deep Bedrock Aquifer System
Elmhurst-Mt. Simon Aquifer
ChicagoDeKalbWest East
Cross-Section Modified from Bretz (1939)
Major ShallowBedrock Aquifers
Withdrawals fromShallow Bedrock Aquifers
Total use > 200 mgd
Major Deep Bedrock Aquifers
Withdrawals from Deep Bedrock Aquifers
Total use ~ 100 mgd
Cone of DepressionCone of Depression
Well/Aquifer Interactions
Overlapping Cones of DepressionOverlapping Cones of Depression
Well/Aquifer Interactions
Well/Aquifer Interactions
Overlapping Cones of Depression – Well Interference
Well/Aquifer Interactions
BA
Overlapping Cones of Depression – Well Interference
Well/Aquifer Interactions
Overlapping Cones of Depression – Well Interference
BA
Well/Aquifer Interactions
Overlapping Cones of Depression – Well Interference
BA
Well/Aquifer Interactions
Overlapping Cones of Depression – Well Interference
BA
NE Illinois Deep Bedrock Withdrawals, NE Illinois Deep Bedrock Withdrawals, 19001900--20002000
1860 1880 1900 1920 1940 1960 1980 2000Year
0
20
40
60
80
100
120
140
160
180
200
Mill
ion
Gal
lons
per
Day
182.9 mgd(1979)
71.9 mgd(2000)
Estimated Practical Sustained Yield (Ideal Well Distribution)= 65
mgd
Estimated Practical
Sustained Yield (1958
Well Distribution)=
46 mgd
DistributionOf DeepBedrockAquiferPumpage
Source: Jaffe
PotentiometricPotentiometricSurface of theSurface of theDeep Bedrock Deep Bedrock
Aquifer System, Aquifer System, Fall 2000Fall 2000
Potentiometric Surface Across NE Illinois
WESTEAST
DeKalb Elburn
Geneva ElmhurstBellwood
Industr ial site in Chi cago
-1200
-1000
-800
-600
-400
-200
0
200
400
600
800
1000
-1000
-800
-600
-400
-200
0
200
400
600
800
1000
-1200
Elevation (ft) Elevation (ft)
Ironton-Galesville Ss
St. Peter Ss
Deep Well Water Levels, Cook CountyDeep Well Water Levels, Cook County
Oswego #3 (Kendall County)Oswego #3 (Kendall County)
1950 1960 1970 1980 1990 20000
100
200
300
400
500
600
Ele
vatio
n ab
ove
Sea
Lev
el (f
eet)
Groundwater Flow Groundwater Flow Modeling: NE IllinoisModeling: NE IllinoisRegional Model GridRegional Model Grid
226 rows226 rows174 columns174 columns18 layers18 layers707,832 nodes707,832 nodesMinimum grid Minimum grid spacing of 2500spacing of 2500’’Maximum grid Maximum grid spacing of 80,000spacing of 80,000’’
Modeled Heads in upper GalenaModeled Heads in upper Galena--Platteville Platteville -- 20022002
Modeled Heads in lower GalenaModeled Heads in lower Galena--Platteville Platteville -- 20022002
Modeled Heads in Modeled Heads in AncellAncell (St. Peter) (St. Peter) -- 20022002
Modeled Heads in IrontonModeled Heads in Ironton--Galesville Galesville -- 20022002
Look for more information and updates:http://www.sws.uiuc.edu/wsp
E-mail me with questions:[email protected]
Thanks!