Unit 8 – Water

1. Ch.21 Unit 8 – Water Water Fresh & total Water supply locations Groundwater overdraft desalination Disinfection of wastewater (chlorine, ozone, UV) Oligotrophic Eutrophic Groundwater - aquifers (recharge areas) Oil spill cleanup Review ART Instream/offstream Figure 18-2

2. AMAZING WATER!! Water is fundamental to all life on Earth The Properties of Water: Polar molecule “Universal Solvent” Ice is less dense than liquid water Surface Tension Adhesion (other) Cohesion (self)

3. Ch.21 Unit 8 – Water Figure 18-2

4. Ch.21 Unit 8 – Water Cone of Depression Water Use • Groundwater overdraft leads to: • Damage to river ecosystems • Loss of aquatic habitats • Damage to riparian ecosystems • Land Subsidence • Salt Water Intrusion In-stream: Navigation, Hydroelectric Power, Fish & Wildlife Habitats Recreation, etc Off-stream: Consumptive use; Water is used and not returned to its source Industrial, municipal use Figure 18-2

5. Ch.21 Unit 8 – Water Water Use & Supply • Ogalla Aquifer • Discharge rates > Recharge rates • Has been steadily decreasing since the early 1950’s • Due too… Figure 18-2 The Green Revolution!! (Satellite image of NW Texas over the Ogalla Aquifer)

6. Ch.21 Unit 8 – Water ART = 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 days Figure 18-2

7. Ch.21 Unit 8 – Water Desalination Figure 18-2

8. Ch.21 Unit 8 – Water Figure 18-2

9. Ch.21 Unit 8 – Water Figure 18-2

10. Ch.21 Unit 8 – Water Figure 18-2

11. Ch.21 Unit 8 – Water Septic System: A personal water treatment system Figure 18-2

12. Ch.21 Unit 8 – Water The 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 effluent limits. The CWA also requires the acquisition of a National Pollution Discharge Elimination System (NPDES) permit prior to the discharge of pollutants.