WATER CYCLE

WATER CYCLE

WATER (Hydrologic) CYCLE

• It is a “redistribution” of water. A drought somewhere = more water somewhere else

Can you name the processes?

• http://www.teachersdomain.org/resource/ess05.sci.ess.watcyc.watercycle/

How are groundwater and surface water connected?

Percolation and Seepage

Earth = the natural filter

Surface water vs. Groundwater

Which is generally more polluted?

~ Surface Water

Which is harder to clean up?

~ Groundwater

Groundwater pollution sticks around...

• Very cold, no bacterial breakdown

• Very slow water movement: recharge can take 100’s or 1000’s of years

• Pollutants can stick to rocks in aquifer and pollute new water

What Pollutes Groundwater?

Sources of Groundwater pollution...

• landfills• leaky underground storage tanks• mines• septic tanks• hazardous waste - deep well injection• any pollutant in runoff that percolates

Laws• Clean Water Act – surface water

– 1972 – make water swimmable and fishable by regulating point sources

– 1977 and 1987 – storm water runoff– Section 404 – requires permit for draining,

dredging, filling wetlands• Mitigation banking

• Safe Drinking Water Act (1974) – monitors levels of contaminants in groundwater

Case Study: Natural Gas Drilling• Marcellus Shale

• Fracking - Hydraulic Fracturing

• Loophole in Safe Water Drinking Act– natural gas companies don’t have to disclose chemicals being used

http://gaslandthemovie.com/

How can we protect groundwater?• Prevention is the key…

– Monitor aquifers & landfills– Requirements for old fuel tanks

• Leak detection system• Liability insurance

– Stricter regulations on toxic waste disposal• Above-ground storage of toxic waste...but then you

have toxic mud spills!