Groundwater sustainability Flashcards
List some consequences of excessive withdrawal of subsurface water.
- depletion of groundwater
- degradation of water quality
- cause subsidence due to dewatering and a permanent decrease in aquifer yield
What are two examples of groundwater sustainability?
Artificial recharge
- building artificial aquifers with wastewater
-water goes into the aquifer and gets filtered, therefore recharging the groundwater
Increase infiltration and recharge of storm water
- replacing city storm water drains and pipes with vegetated swales
-removing curbs
-reducing the amount of impermeable surfaces - collecting roof gutter discharge for garden use
What are the effects of pumping near streams/ rivers?
Natural condition
- before pumping
- waters flow from unconfined aquifer into the stream
Formation of divide
- some groundwater goes to the well, some goes to the stream
Reversal of flow
-surface water is captured into he aquifer to provide for the well
What is saltwater intrusion, and solution?
-saltwater is drawn into aquifers when groundwater extractions (near the coast) exceed aquifer recharge.
Solution
- limit groundwater withdrawal
Transition zones (dispersion zones)
The part between freshwater and saltwater
What is a Capture zone?
-most contaminated
-avoid extraction of water in the capture zone
List and describe several sources of
groundwater contamination
Pollution of groundwater due to human activities
-Chlorinated solvents (PCE, TCE)
– Wood preservatives (creosote, phenol)
– Gasoline and oil (benzene, toluene, MTBE)
– Metals (e.g., chrome plating, mining industry)
– Agricultural contaminants (pesticides, fertilizer)
– Radionuclides (radioactive waste disposal)
– Pharmaceuticals, household/beauty products
LNAPL
light non-aqueous phase liquid
-organic liquids that are less dense than water and do not dissolve in it.
DNAPL
Dense Non-Aqueous Phase Liquid
-Organic fluids that are more dense than water and do not mix or dissolve in them.
What are four source contamination remediation?
Dig and dump
-easier to do if the contamination is in earlier stages (hasn’t moved a lot)
Pumping it out
-if free phase liquid
-very difficult to do and always leaves residue behind (partly successful)
LNAPL
-Changing the phase to gas
-skimming it off
Bioremediation
-Leave the contamination for the remediation by natural cycle
-can pump in oxygen to help change their phrase and pump or vacuum it out
Plume treatment
Reactive material was installed as a filter in the path of the water plume.
Radioactive waste treatment
Store underground
-best solution
Bury under the ocean floor or in polar ice caps.
Shoot into space.
Do nothing.
