Groundwater and Wells: An Introductory Discussion with Application to
Northeastern Illinois. H. Allen Wehrmann, P.E.. Illinois State Water Survey.
Groundwater and Wells: An Introductory Discussion with Application to Northeastern Illinois
H. Allen Wehrmann, P.E. Illinois State Water Survey Illinois Department of Natural Resources
2007 Priority Places Workshop: Implementing a Sustainable Water Supply for Kane County’s Future
Topical Presentation Outline Basic Concepts and Definition
The Hydrologic Cycle What
Is Groundwater?
Concepts and Definitions Porous
Flow vs. Fractured Flow Aquifers vs. Aquitards Artesian vs. Water Table Conditions
Regional Groundwater G Flow Systems S Well and Aquifer Hydraulics
2007 Priority Places Workshop: Implementing a Sustainable Water Supply for Kane County’s Future
The Water Cycle Climate, surface water, and groundwater are linked
2007 Priority Places Workshop: Implementing a Sustainable Water Supply for Kane County’s Future
Porous Systems Groundwater flows through pore spaces between grains
2007 Priority Places Workshop: Implementing a Sustainable Water Supply for Kane County’s Future
Fractured Systems
2007 Priority Places Workshop: Implementing a Sustainable Water Supply for Kane County’s Future
Fractured Limestone or Dolomite
2007 Priority Places Workshop: Implementing a Sustainable Water Supply for Kane County’s Future
Aquifers vs. Aquitards
An aquifer is a saturated bed, formation, or group of formations that yields water in sufficient quantity to be of consequence as a source of supply.
An aquitard yields inappreciable quantities of water, but leakage of water through the aquitard is possible. Aquitards often act as confining beds.
2007 Priority Places Workshop: Implementing a Sustainable Water Supply for Kane County’s Future
Unconfined vs. Confined Groundwater
An unconfined aquifer is one in which groundwater possesses a free surface open to the atmosphere. The upper surface of the zone of saturation is called the water table.
A confined fi d aquifer if is i one iin which hi h groundwater d t iis confined under pressure by overlying and underlying aquitards or aquicludes, and water levels in wells rise above b th the ttop off the th aquifer. if A confined fi d aquifer if is i also l called an artesian aquifer.
2007 Priority Places Workshop: Implementing a Sustainable Water Supply for Kane County’s Future
Unconfined Aquifers Land Surface Unsaturated ((Vadose)) Zone Water Table
Saturated Zone Unconfined Aquifer
Bedrock
2007 Priority Places Workshop: Implementing a Sustainable Water Supply for Kane County’s Future
Confined Aquifers Land Surface Unsaturated (Vadose) Zone Water Table
Unconfined Aquifer
Saturated Zone
Potentiometric Surface
Confining Layer - Aquitard
Confined Aquifer
Bedrock
2007 Priority Places Workshop: Implementing a Sustainable Water Supply for Kane County’s Future
Confined Aquifers and Artesian Wells Flowing artesian well Land surface
Confining layer
Confined Aquifer f
2007 Priority Places Workshop: Implementing a Sustainable Water Supply for Kane County’s Future
Regional Groundwater Flow Systems 0.1 mile 20 miles
Depth
0’
100’ 10’
200’ 20’ 2007 Priority Places Workshop: Implementing a Sustainable Water Supply for Kane County’s Future
Cone of Depression
2007 Priority Places Workshop: Implementing a Sustainable Water Supply for Kane County’s Future
Overlapping Cones of Depression
2007 Priority Places Workshop: Implementing a Sustainable Water Supply for Kane County’s Future
Overlapping Cones of Depression: Well Interference
2007 Priority Places Workshop: Implementing a Sustainable Water Supply for Kane County’s Future
Overlapping Cones of Depression: Well Interference
2007 Priority Places Workshop: Implementing a Sustainable Water Supply for Kane County’s Future
Overlapping Cones of Depression: Well Interference
2007 Priority Places Workshop: Implementing a Sustainable Water Supply for Kane County’s Future
Overlapping Cones of Depression: Well Interference
2007 Priority Places Workshop: Implementing a Sustainable Water Supply for Kane County’s Future
Potentiometric S f Surface off the th Deep Bedrock A if S Aquifer System, t Fall 2000
2007 Priority Places Workshop: Implementing a Sustainable Water Supply for Kane County’s Future
Potentiometric Surface across NE Illinois WEST
EAST
Elevation (ft)
Elevation (ft)
1000
1000
DeKalb 800
Elburn Geneva
800
Elmhurst Bellwood
Industrial site in Chi cago
600
600
400
400
200
200
0
St. Peter
0
Ss
- 200
-200
- 400
-400
- 600
- 800
Ironton -Galesviil le
Ss
-600
-800
-1000
-1000
-1200
-1200
2007 Priority Places Workshop: Implementing a Sustainable Water Supply for Kane County’s Future
Deep Well Water Levels Levels, Cook County
2007 Priority Places Workshop: Implementing a Sustainable Water Supply for Kane County’s Future
Deep Well Water Levels, Kendall County 600
Ellevation abov ve Sea Level (feet)
500
400
300
200
100
Oswego #3 0 1950
1960
1970
1980
1990
2000
2007 Priority Places Workshop: Implementing a Sustainable Water Supply for Kane County’s Future
Water Sources for Public Supply in Northeast Illinois
2007 Priority Places Workshop: Implementing a Sustainable Water Supply for Kane County’s Future