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Unit 8 WaterCh.21WaterFigure 18-2Disinfection of wastewater (chlorine, ozone, UV)

OligotrophicEutrophic

Groundwater - aquifers (recharge areas)

Oil spill cleanup

Review ART

Instream/offstreamFresh & total Water supply locations

Groundwater overdraft

desalination1

AMAZING WATER!!Water is fundamental to all life on EarthThe Properties of Water:Polar moleculeUniversal SolventIce is less dense than liquid waterSurface TensionAdhesion (other)Cohesion (self)

Unit 8 WaterCh.21Figure 18-2

3Unit 8 WaterCh.21Figure 18-2

Cone of DepressionGroundwater overdraft leads to:Damage to river ecosystemsLoss of aquatic habitatsDamage to riparian ecosystems Land SubsidenceSalt Water Intrusion

In-stream:Navigation,Hydroelectric Power,Fish & Wildlife HabitatsRecreation, etcOff-stream:Consumptive use;Water is used and not returned to its sourceIndustrial, municipal useWater Use4The Green Revolution!!(Satellite image of NW Texas over the Ogalla Aquifer)Unit 8 WaterCh.21Figure 18-2

Ogalla AquiferDischarge rates > Recharge ratesHas been steadily decreasing since the early 1950sDue too

Water Use & Supply5Unit 8 WaterCh.21Figure 18-2ART = Size of reservoir Rate of Transfer

If a sustainable aquifer consisting of 40,000 m3 of water is polluted with a water soluble toxin how many days will the pollutant remain in the aquifer if wells pump out 50 m3 of water per hour

40,000 m3 50 m3/hr = 800 hrs = 33.3 days6Unit 8 WaterCh.21Figure 18-2

Desalination7Unit 8 WaterCh.21Figure 18-2

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10Unit 8 WaterCh.21Figure 18-2

Septic System:A personal water treatment system11Unit 8 WaterCh.21The Clean Water Act serves to: regulate the discharge of point pollution into U.S. waterways attain water quality levels that make these waterways safe to fish and/or swim in restore and maintain the chemical, physical, and biological integrity of the nations water prevent habitat destruction set water quality standards to limit pollutants establish ongoing monitoring of local waterways provide financial assistance to fund improvements/education/training provide enforcement mechanisms (e.g. civil actions/criminal penalties) to ensure compliance establish best practical control technology (BPT) to reduce pollution establish best available, economic achievable technology (BAT) to reduce toxins establish best management practices (BMPs) to reduce pollution. require discharge permits for effluent emissions

require states and tribes to complete an assessment of all state rivers impacted, or potentially impacted, by non-point pollution (Section 319, 1987) reduce polluted runoff from urban areas and animal feeding operations (Section 319, 1987)

The Clean Water Act (CWA), passed by Congress in 1972, provides the basic structure for regulating the discharge of pollutants from point sources to waters of the United States. The CWA gives the EPA the authority to establish efuent limits.

The CWA also requires the acquisition of a National Pollution Discharge Elimination System (NPDES) permit prior to the discharge of pollutants.

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