drinking water quality

1. Drinking Water QualityDrinking Water Quality

2. WATER TREATMENTWATER TREATMENT
 ReservoirsReservoirs – allow clarification, increased– allow clarification, increased
D.O., and settlingD.O., and settling
 Water purification plantsWater purification plants andand watershedwatershed
protectionprotection can provide safe drinking water forcan provide safe drinking water for
urban areas in developed countriesurban areas in developed countries

4. How It’s Made Drinking Water

5. Case Study: PeruCase Study: Peru
 StoppedStopped chlorinationchlorination – concern over– concern over
increased cancer riskincreased cancer risk
 1991 – cholera outbreak – 300,000 sick,1991 – cholera outbreak – 300,000 sick,
3,500 deaths3,500 deaths

6. OTHER WAYS TO PURIFY WATEROTHER WAYS TO PURIFY WATER
 Can process sewer water to drinking waterCan process sewer water to drinking water

Not as expensive as desalinationNot as expensive as desalination
 Simpler and cheaper ways can be used toSimpler and cheaper ways can be used to
purify drinking water for developing countriespurify drinking water for developing countries

Ex: exposing water to heat and sun’s UV rays forEx: exposing water to heat and sun’s UV rays for
3 hrs. kills many infectious microbes3 hrs. kills many infectious microbes

Various filters – ex: LifeStrawVarious filters – ex: LifeStraw

PUR – chlorine and iron sulfate powderPUR – chlorine and iron sulfate powder

7. Using Laws to Protect Drinking WaterUsing Laws to Protect Drinking Water
 Developed countries – most have drinkingDeveloped countries – most have drinking
water quality standards and lawswater quality standards and laws

U.S. Safe Drinking Water Act (1974)U.S. Safe Drinking Water Act (1974) – requires– requires
EPA to establish national drinking waterEPA to establish national drinking water
standards (standards (maximum contaminant levelsmaximum contaminant levels) for) for
any pollutant that may have adverse effects onany pollutant that may have adverse effects on
human health – monitoredhuman health – monitored
 Developing countries – most do not or notDeveloping countries – most do not or not
enforcedenforced

8. Using Laws to Protect Drinking WaterUsing Laws to Protect Drinking Water
 The U.N. estimates 5.6 million AmericansThe U.N. estimates 5.6 million Americans
drink water not meeting EPA standardsdrink water not meeting EPA standards
 1 in 5 Americans drinks water from a1 in 5 Americans drinks water from a
treatment plant that violated one or moretreatment plant that violated one or more
safety standardsafety standard
 Industry pressures to weaken the SafeIndustry pressures to weaken the Safe
Drinking Water Act:Drinking Water Act:

Eliminate national tests and public notification ofEliminate national tests and public notification of
violationsviolations

Allow rights to pollute if provider cannot afford toAllow rights to pollute if provider cannot afford to
complycomply

9. Case Study: Flint, MichiganCase Study: Flint, Michigan
 2014 – switched water source from Detroit2014 – switched water source from Detroit
water (Lake Huron and Detroit River) to Flintwater (Lake Huron and Detroit River) to Flint
River – to save $River – to save $
 Flint River water corroded pipes – releasedFlint River water corroded pipes – released
lead from pipes into waterlead from pipes into water
 Extremely high lead levels – exposingExtremely high lead levels – exposing
thousands – including children – learningthousands – including children – learning
disabilities – attention problemsdisabilities – attention problems

10. Long Island Drinking WaterLong Island Drinking Water
All GroundwaterAll Groundwater

11. Long Island’s Drinking Water –
Challenges and Solutions

12. Is Bottled Water the Answer?Is Bottled Water the Answer?
 Bottled water often more polluted and lessBottled water often more polluted and less
regulated than tap waterregulated than tap water
 Costs much more – 120 to 10,000XCosts much more – 120 to 10,000X
 Often just bottled tap waterOften just bottled tap water

1.4 million metric tons of plastic waste1.4 million metric tons of plastic waste

Toxic chemicals used to make plasticToxic chemicals used to make plastic

Fossil fuels to make and transport plastic bottlesFossil fuels to make and transport plastic bottles
• The oil used to produce plastic bottles in the U.S. eachThe oil used to produce plastic bottles in the U.S. each
year would fuel 100,000 carsyear would fuel 100,000 cars

13. The Story of Bottled Water

14. Fig. 21-18, p. 517
• Prevent groundwater contamination
Solutions
Water Pollution
• Reduce birth rates
• Reduce poverty
• Reduce air pollution
• Practice four R's of resource use (refuse,
reduce, recycle, reuse)
• Work with nature to treat sewage
• Find substitutes for toxic pollutants
• Reuse treated wastewater for irrigation
• Reduce nonpoint runoff

15. Fig. 21-19, p. 517
What Can You Do?
Water Pollution
• Fertilize garden and yard plants with manure or
compost instead of commercial inorganic fertilizer.
• Minimize your use of pesticides.
• Do not apply fertilizer or pesticides near a body of water.
• Grow or buy organic foods.
• Do not drink bottled water unless tests show that your
tap water is contaminated. Merely refill and reuse
plastic bottles with tap water.
• Compost your food wastes.
• Do not use water fresheners in toilets.
• Do not flush unwanted medicines down the toilet.
• Do not pour pesticides, paints, solvents, oil, antifreeze,
or other products containing harmful chemicals down
the drain or onto the ground.