GROUNDWATER
TEACHING
TOOLS
Jim Lundy, Minnesota Department of Health
Minnesota Minerals Education Workshop
Hibbing, Minnesota
June 18, 2013
WHY IS WATER
SO IMPORTANT,
ANYWAY?
WHY IS WATER
SO IMPORTANT,
ANYWAY?
• Your body is 70% water
– If you weigh 100 pounds, 70 pounds of you is water
– To stay healthy:
• Drink at least a half-gallon of water each day (more if active or sick)
• Survival?
– No food: at least a month
– No water: four days
http://www.geology.wisc.edu/~maher/air/air08.htm
EARTH:
THE WATERY
PLANET
• Percent of Earth’s surface covered
• Earth landforms
• Goldilocks: “Just right”
http://www.geology.wisc.edu/~maher/air/air08.htm
EARTH:
THE WATERY
PLANET
• Percent of Earth’s surface covered
• Earth landforms
• Goldilocks: “Just right”
Earth diameter:
8,000 miles
Earth globe
diameter: 1 foot
Sun diameter:
864,000 miles
Scale distance:
2.2 miles
Scale diameter:
108 feet
• Common geologic materials
– Gravel
– Sand
– Clay
• Class exercise
• Groundwater flow model
GROUND
WATER FLOWS
DIFFERENTLY
IN DIFFERENT
MATERIALS
GRAVEL
SAND
CLAY
MINNESOTA’S
GLACIAL
GEOLOGY
MINNESOTA’S
BEDROCK
GEOLOGY
GROUNDWATER
CONCEPTS
• Aquifer
– Underground formation that can
store and transmit water
GROUNDWATER
CONCEPTS
• Aquifer
– Underground formation that can
store and transmit water
• Confining layer
– Underground formation that does
not store and transmit water
GROUNDWATER CONCEPTS
• Aquifer
– Underground formation that can
store and transmit water
• Confining layer
– Underground formation that does
not store and transmit water
• Porosity
– Void space (%)
•
•
•
•
GROUNDWATER
CONCEPTS
Aquifer
– Underground formation that can
store and transmit water
Confining layer
– Underground formation that does
not store and transmit water
Porosity
– Void space (%)
Permeability
– “Connectedness” of the void
spaces
– How easily water can flow
•
•
•
•
•
GROUNDWATER
CONCEPTS
Aquifer
– Underground formation that can
store and transmit water
Confining layer
– Underground formation that does
not store and transmit water
Porosity
– Void space (%)
Permeability
– “Connectedness” of the void
spaces
– How easily water can flow
Yield
– How much water an aquifer can
produce (gallons per minute)
Mesabi Range
Iron Formation
North
3
Elevation in Feet Above Sea Level
South
Keewatin #1
W ell
Keewatin #2
W ell
1500
1500
Generalized Geologic Cross-Section
National
Steel
National
Steel PPellet
ellet
N Company
ational S teel Pellet
Carlz P it
Company Offic e W ell
W elcome
Lake
Company Pit D ry W ell
Section 18 Pit
1300
1300
1100
1100
?
900
900
700
700
2000 feet
2000 feet
Well Construction
Cased Interval
Open Hole Interval
Glacial Deposits
Syenite Dike
Virginia Formation
Upper Slaty, Upper Cherty
and Lower Slaty Members
Biwabik Iron Formation
Figure 2. Generalized geologic cross-section of the Keewatin-National Steel Pellet Company area.
Intermediate Slate
Lower Cherty Member
Biwabik Iron Formation
Pokegema Quartzite
Giants Range Granite
AQUIFERS OF
SOUTHEASTERN
MINNESOTA
• Aquifers
– Glacial sands and gravels
(in valleys)
– Devonian carbonate
rock
– Galena Limestone
– St. Peter Sandstone
– Prairie du Chien-Jordan
– Franconia-IrontonGalesville
– Mt. Simon Sandstone
CONFINING
LAYERS OF
SOUTHEASTERN
MINNESOTA
• Confining Layers
– Dubuque Formation
– Decorah-PlattevilleGlenwood
– St. Lawrence
– Eau Claire
Classroom activity: Geology of Southeastern Minnesota
Mankato
Rochester
Faribault
Winona
Mankato
Rochester
Faribault
Winona
WATER
QUALITY:
WATER IS
STICKY
Tipping, Robert G., 1994, Minnesota Geological Survey Open-File Report 94-1
•
•
•
•
Rain is slightly acidic, pH=5.5
“Pure” water
Chemical constituents of water
Pollutants
SOUTHEAST
MINNESOTA
VOLUNTEER
NITRATE
MONITORING
STUDY
PROBLEM: TCE IN FARIBAULT WELL #4
Faribault is in Rice County, on
the edge of karst country
• Trichloroethene
– Dense solvent,
carcinogenic
– Up to 209 ug/L
– Standard 30 ug/L
FARIBAULT
INVESTIGATION
ACTIVITIES
• Drill borings and test wells
• Sample water for VOCs
– Interval sampling for 3-D picture
• Other tests
• Make maps, reports, recommendations
PROJECT SETTING
CW-4
RESULTS
• Low TCE in most borings
• TCE present in some
borings at depth
• Plume aligns with one
source (PCE/TCE)
TCE CONTAMINATION
SOURCE
TCE CONTAMINATION
SOURCE
Information collected supported a plan for
removing TCE exposure in Faribault
CLASSROOM ACTIVITY:
TROUBLE IN PARADISE
Girl Scouts on a fossil hunt at the Brickyards, St. Paul
MORE
RESOURCES
• Minnesota Project WET (Water Education for Teachers)
– April Rust, MDNR, 651-259-5709
• Winona State University Water Resources Center
– http://www.winona.edu/geology/2630.htm
• United States Geological Survey
– http://education.usgs.gov/index.html
• Minnesota Department of Natural Resources (MDNR)
– http://www.dnr.state.mn.us/groundwater/index.ht
ml
• Minnesota Pollution Control Agency (MPCA)
– http://www.pca.state.mn.us/index.php/water/wate
r-types-and-programs/groundwater/aboutgroundwater/karst-in-minnesota.html
– http://www.pca.state.mn.us/index.php/water/wate
r-types-and-programs/groundwater/groundwaterbasics/groundwater-basics.html
• Minnesota Ground Water Association (MGWA)
– http://www.mgwa.org/education.php