1. Groundwater - Surface Water Interaction and Contaminant Movement
Teacher Workshop March 13, 2015
UNC-CH
Amy Keyworth
NCDENR Division of Water Resources
Groundwater - Surface Water Interaction and Contaminant Movement
Where water occurs, how we use it, and how it moves
Setting of groundwater and its relationship to surface water
Groundwater contamination and remediation
Division of Water Resources

2. Exploring Geology by Reynolds Johnson Kelly Morin Carter
Acknowledgements/resources
Textbook
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

3. Resources http://water.usgs.gov/education.html
Google images – USGS losing stream
Acknowledgements/resources
Google images – USGS losing stream

4. Acknowledgements Christine Blanton Lawson (NCDENR DWR)
Evan Kane (NCDENR DWR)
Ben Mirus (USGS)
Acknowledgements/resources
Christine Blanton Lawson (NCDENR DWR)
Evan Kane (NCDENR DWR)
Ben Mirus (USGS)

5. Where is the water? Biological water Water in minerals
Ocean currents
Glaciers
Clouds and precipitation
Flowing water
Lakes
Groundwater
Oceans
Where is the water?
Note the groundwater piece
Biological water: water in cells and structures of plants
Water in minerals

6. How Does Water Move?
How Does Water Move?

7. How Does Water Move? Air currents Condensation Evaporation
Precipitation
Runoff
Infiltration (recharge)
Groundwater discharge
Transpiration from plants
How Does Water Move?
List of the processes
Concentrate on groundwater discharge and recharge

8. How Does Water Move? Air currents Condensation Evaporation
Precipitation
Runoff
Infiltration (recharge)
Groundwater discharge
Transpiration from plants
How Does Water Move?
Use all to create a water balance
Water Balance Equation – Inputs = Outputs

9. Distribution of Water EXPLANATION
Most of Earth’s water probably originated during the formation of the planet or from comets and other icy celestial objects
Most of this water moves to the surface over time, such as when magma releases water vapor during eruptions
We don’t know how much is trapped as water molecules in minerals in the crust and the mantle
<1% is visible to us as surface water

10. Estimated Water Age Residence Time Oceans and seas @ 4000 years
Lakes and reservoirs
@ 10 years
Swamps
1-10 years
Rivers
@ 2 weeks
Soil Moisture
2 wks to 1 yr
Groundwater
2 wks to 10,000 yrs
Icecaps and glaciers
10-1,000 yrs
Atmospheric Water
@ 10 days
Millions
Age of water in different parts of Earth
Note groundwater
Wide range of ages
Generally meteoric or from precipitation
Slow to recharge especially in deeper confined aquifers
Fossil water
can be millions of years old
Not being recharged
Ogallala aquifer – S Dakota to Texas
Source: Nace, 1971

11. Groundwater Age http://en.wikipedia.org/wiki/File:Groundwater_flow.svg
This is the kind of aquifer system we have in the coastal plain
Groundwater operates differently in the Piedmont and mountains
Note groundwater
Wide range of ages
Generally meteoric or from precipitation
Slow to recharge especially in deeper confined aquifers
Fossil water
can be millions of years old
Not being recharged
Ogallala aquifer – S Dakota to Texas

12. Water Use in U.S. EXPLANATION
Much of the thermoelectric power usage is with saltwater
Some water used in irrigation is returned to canals and rivers and some soaks into the ground
NOTES
Top photograph: Ephrata, Washington
What industrial uses are you aware of?
How does human use change the water?
Temperature
Chemistry
Waste
Bottled vs public water supply
P 505 – EPA standards

13. Groundwater Between Grains
Most groundwater in pore spaces between grains and clasts
Pores in upper parts generally unsaturated
Below, pores saturated with groundwater
EXPLANATION
By clasts, we mean grains of sand, silt, and clay-sized particles, as well as pebbles, cobbles, and boulders
Usually clasts of different sizes are present in sediment (sorting)
Top of saturated zone is water table
17.03.a1

14. How Does Groundwater Accumulate?
Evapotranspiration
Precipitation
Surface runoff
Wetlands and lakes
How Does Groundwater Accumulate?
We’re pretty familiar with the surface processes
Rain or snowmelt can evaporate or be captured by plants
Water can flow down the surface as runoff
Water can accumulate on the surface in wetlands and lakes
If you think about how much water is in groundwater you have to consider how it gets there
and what happens to it once there.
Water can seep into the ground
Water can reach the water table and seep down into the saturated zone
Below the water table, groundwater can flow if the rocks are have interconnected spaces
Infiltration
Reach water table and saturated zone
Groundwater flow
17.03.b1

15. Needed for groundwater to flow
Change in elevation or pressure (head)
Porosity
Permeability
Needed for groundwater to flow
Change in elevation or pressure (head)
Porosity
Permeability

16. Porosity: Proportion of Open Space
Which of the following have lower porosity and which have higher porosity?
High porosity
Rounded, sorted clasts do not fit tightly
Clay particles do not fit tightly
High porosity
Lower porosity
Porosity: Proportion of Open Space
Loose clay – holds a lot of water
Fresh granite – tight crystals – little pore space
Well-rounded, well-sorted clasts do not fit tightly
Poorly sorted, angular clasts fit more tightly
Crystals in granite fit tightly
Poorly sorted clasts fit more tightly
Low porosity

17. Permeability: Pores Connected So Fluids Flow
High permeability
Granite with many fractures
Loosely cemented gravels
Low permeability
Permeability: Pores Connected So Fluids Flow
What family of rocks has porosity and permeability when it first forms?
What family has porosity only after fracturing?
Websites – play 2 and 4
Porous volcanic rock with isolated pores
Compacted clay (shale)

18.
Websites – play 2 and 4