3/6 APES

1. Pick up the 4 handouts as you come in

2. Extra Credit Quiz

3. Unit 10 PPT

I will have a printed Agenda for you tomorrow

Quizzes/Tests:

3/8- Quiz 1

3/16- Quiz 2

3/22- Unit Test

3/23- Midterm

Possible Answers

Ques.

#

A B C D E

1

2

For each question, allocate 5 points to the answer(s) you have

selected. For example, if you’re sure that the answer to question 1

is “A”, you would allocated 5 points to “A”. If you are not sure

whether the answer is “A” or “D”, you might allocate 3 points to “A”

and 2 points to “D”. Do not use decimals. Maximum of 10 points

can be earned.

APES Unit 10: Water Use & Pollution

Water Changes everything: http://youtu.be/BCHhwxvQqxg

Water Changes Everything

Water footprint: Volume of water we directly and indirectly use

Average American uses 260 liters per day Flushing toilets, 27% Washing clothes, 22% Taking showers, 17% Running faucets, 16% Wasted from leaks, 14% World’s poorest use 19 liters per day

• More water is used indirectly = virtual water• Hamburger = 2,400 liters

• Virtual water often exported/imported • Grains and other foods

Water Footprints and Virtual Water

Water infiltrates the soil and percolates until it reaches an impermeable layer

Zone of saturation: Stored in spaces between soil/gravel, and rock

Water table – upper level of groundwater

Usually follows shape of land

Groundwater recharge- when

rain percolates through the soil

and goes into an aquifer.

Groundwater

Unconfined aquifers-porous rock covered by soil, water can flow easily in and out.

Confined aquifers-aquifers surrounded by impenetrable rock or clay that impedes water flow to or from the aquifer. Confined aquifers need an opening at the land’s surface that can serve as a recharge area.

Discharge zone- where water seeps out

Springs bring water up from the aquifers to the surface and become freshwater aquatic biomes.

Artesian wells- a hole is drilled into a confined aquifer, releasing the pressure on the water, and the water rises up in the well.

Confined Aquifer Unconfined Aquifer

Recharged very slowly (10,000-20,000 yrs)

Recharged often through precipitation

Much older water and is less likely to be contaminated by anthropogenic chemicals

Water is likely to be contaminated with chemicalsand pollution

Unsustainable large scale use

When the rate of recharge does not keep pace with the rate of withdrawal, water runs out

Urban vs. Pre-Urban Floodplains

Fig. 14-3, p. 308

Unconfined Aquifer Recharge Area

Precipitation Evaporation and transpiration Evaporation

Confined

Recharge

Area

Runoff

Flowing

artesian

well

Recharge

Unconfined

Aquifer

Stream Well

requiring a

pumpInfiltration Water

table LakeInfiltration

The Ogallala Aquifer- the

largest aquifer in the US,

found in the Great Plains

Kansas Crops Irrigated by the Ogallala Aquifer

Most aquifers are renewable resources unless water is removed faster than it is replenished or if they are contaminated.

Groundwater depletion is a growing problem mostly from irrigation.

At least one-fourth of the

farms in India are being

irrigated from overpumped

aquifers.

Withdrawing Groundwater

Drought + poor irrigation = dried up crops

The Ogallala, the world’s largest aquifer, is most of the red area in the center (Midwest).

Groundwater Depletion: A Growing Problem

Areas of greatest aquifer depletion from groundwater overdraft in the continental U.S.

Figure 14-8

Irrigation systems from the nonrenewable aquifer appear as green dots. Brown dots are wells that have gone dry.

Groundwater Pumping in Saudi Arabia (1986 – 2004)

Limits future food production

Land subsidence

Mexico City

San Joaquin Valley in California

Groundwater overdrafts near coastal regions

Contamination of groundwater with saltwater (saltwater intrusion)

Overpumping Aquifers Has Several Harmful Effects

This pole shows subsidence from overpumping of an aquifer for irrigation in California’s San Joaquin Central Valley between 1925 and 1977.

In 1925, the land surface in this area was near the top of this pole.

Since 1977 this problem has gotten worse.

Subsidence in the San Joaquin Valley

Fig. 13-11, p. 327

Sinkholes form when the roof of an

underground cavern collapses after being

drained of groundwater.

Groundwater Overpumping

Saltwater Intrusion

Advantages

Useful for drinking and irrigation

Available year-round

Exists almost everywhere

Renewable if not overpumped or contaminated

No evaporation losses

Cheaper to extract than most surface waters

Disadvantages

Aquifer depletion from overpumping

Sinking of land (subsidence) from overpumping

Polluted aquifers for decades or centuries

Saltwater intrusion into drinking water supplies near coastal areas

Reduced water flows into surface waters

Increased cost and contamination from deeper wells

Withdrawing Groundwater

Agriculture = 70%

Irrigation of arid and semi arid land

Ogallala used 20x faster than replenished 15% of Texas irrigable land already dry

Industry = 20%

Paper/Pulp – most water

300 million gal = 1 day of US newsprint

Residential/Commercial = 10%

Toilets = 29% Lawns = 29%

Drink/cook=3% Clean laundry-dishes = 17%

Consumptive Water Use

Evaporation from reservoirs, aqueducts, leaks, irrigation

Improve efficiency –

Fix leaks

Increase cost to increase conservation and force people to use water saving technology

Improve irrigation systems ( drip irrigation)

60-70% of water is “Lost”

Types of Irrigation

Furrow irrigation-65% efficient

Spray irrigation- 75-95% efficient

Flood Irrigation-70-80% efficient

Drip Irrigation-over 95% efficient

Levees and Dams-alter the availability of water and prevent rivers from flowing over their banks

onto the floodplain.

Large losses

of water through

evaporation

Flooded land

destroys forests

or cropland and

displaces people

Downstreamflooding is reduced

Downstream

cropland and

estuaries are

deprived of

nutrient-rich silt

Reservoir is

useful for

recreation

and fishing

Can produce

cheap electricity

(hydropower)

Migration and

spawning of

some fish are

disrupted

Provides water

for year-round

irrigation of

cropland

Dams are barriers that run across a river or stream to control

the flow of water.

Fig. 14-13b, p. 317

Powerlines

Reservoir

Dam

PowerhouseIntake

Turbine

Electricity generating turbines inside the Hoover Dam

Main goal of a dam and reservoir system

Capture and store runoff

Release runoff as needed to control:

Reduces flooding downstream

Generates (cheap) electricity

Supply irrigation water year round (especially in arid regions)

Recreation (reservoirs)

Boating, fishing, rafting etc.

Large Dams and Reservoirs Have Advantages and Disadvantages

Displaces people (Flood regions where the reservoir will form) Impaired ecological services of rivers/disrupt aquatic systems. Loss of plant and animal species Fill up with sediment Can cause other streams and lakes to dry up Lots of evaporation from lakes especially in arid regions Migratory fish, salmon, can’t reach spawning areas Fish ladders

Alter sedimentation patterns As water slows – sediment drops Build up sediments behind dams Sedimentation downstream = less Deltas/wetlands/beaches lose land

Disadvantages of Dams

Fish Ladders - have been added to some dams so migrating fish can return to their breeding grounds.

Salmon Population in Columbia River very low due to dams that impede migration

Fish ladders help, but are not effective enough

The largest river in the Pacific

Northwest region of North

America

world’s largest dam

(equivalent of the US filling up the Grand Canyon)

The electric output will be that of 18 large coal-burning or nuclear power plants.

It will facilitate ship travel reducing transportation costs.

Dam displaced over1.4 million people.

Dam is built over seismic fault and already has small cracks. (oops!!)

China’s Three Gorges Dam

Floating Trash Threatens to Clog Three Gorges Dam (1:22) http://youtu.be/Z85-

RM-wXuE

Floods Test China's Three Gorges Dam(1:23) http://youtu.be/nkaFYEmqqy0

Case Study: The California Experience

The Colorado River has so many dams and withdrawals that it does not reach the ocean.

Runs through 7 states

One of world’s most dammed rivers

14 major dams and reservoirs, and canals.

Water is mostly used in desert area of the U.S.

Provides drinking water for 25 million people

90% of Las Vegas’ water

Provides electricity from hydroelectric plants for 30 million people (1/10th of the U.S. population).

The Colorado River Basin

"Chasing Water" (12:19) https://vimeo.com/52955892

The Colorado River Basin

Hoover Dam and Lake Mead

August 2015

Lake Mead is the largest reservoir in the United States in maximum water capacity.

Formed by the Hoover Dam

Lake Mead on the Colorado River

The Flow of the Colorado River Measured at Its Mouth Has Dropped Sharply

Hoover Dam and Lake Mead

In 1998 the U.S. Army Corps of Engineers announced that it would no longer build large dams and diversion projects in the U.S. (The Federal Energy Regulatory Commission has approved the removal of nearly 500 dams.)

Removing dams can reestablish ecosystems, but can also re-release toxicants into the environment.

Dam Removal

“Wild” rivers are free of dams, generally inaccessible except by trail, and represent vestiges of primitive America.

“Scenic” rivers are free of dams, with shorelines or watersheds still largely primitive and shorelines largely undeveloped, but accessible in places by roads.

“Recreational” rivers are readily accessible by road or railroad, may have some development along their shorelines, and may have been dammed in the past.

Wild and Scenic Rivers Act

Delta Dawn: https://vimeo.com/97197932

Pete McBride on Delta Dawn (2:12): http://youtu.be/_v-bPl71BIo

International Cooperation

Excellent example of human interference with the water supply.

The water in the lake was diverted from the lake to the city of Los Angeles. It became a salt bed.

↑ Salt concentration due to evaporation

Mono Lake

Lessons from Mono Lake

(7:10) http://youtu.be/Xq

mbZVQYAPs

Diverting water from the Aral Sea and its two feeder rivers has created a major ecological, economic, and health disaster.

mostly diverted for irrigation

About 85% of the wetlands have been eliminated

Roughly 50% of the local bird and mammal species have disappeared.

Since 1961, the sea’s salinity has tripled and the water has dropped by 22 meters most likely causing 20 of the 24 native fish species to go extinct.

Case Study: The Aral Sea Disaster

Ships Cemetery: Aral Sea Dead Zone of Poisoned Pollution (4:10)

http://youtu.be/e8b0svfuO_k

The Aral Sea was once the world’s fourth largest freshwater lake.

Case Study: The Aral Sea Disaster1975 2008 2012

Natural Capital Degradation: The Aral Sea, Shrinking Freshwater Lake

Agenda:

Pick Up handouts

1. Finish Notes from Yesterday

2. 3 Gorges Dam Case Study/Recap HWK (2 minutes to respond) letsrecap.com Code-ixctccw

**There is no PAWS this Thurs—So if you scheduled to makeup a test you will have to do it today or next Tuesday **

I need to know if you DO NOT plan on taking the AP Exam, #’s are due soon. There is a sign on the door for you to let me know by next Monday

APES 3/7

Removing salt from seawater by current methods is: expensive

produces large amounts of salty wastewater that must be disposed of safely.

Desalination Removing dissolved salts

Distillation: evaporate water, leaving salts behind

Reverse osmosis: (microfiltration) use high pressure to remove salts

14,450 plants in 125 countries

Saudi Arabia: highest number

Other Alternatives: UTEC - Potable Water Generator (1:34) http://youtu.be/35yeVwigQcc

DESALTING SEAWATER

65-70% of the water people use throughout the world is lost through evaporation, leaks, and other losses.

Water is underpriced through government subsidies AND

The lack of government subsidies for improving the efficiency of water use contributes to water waste.

Sixty percent of the world’s irrigation water is currently wasted, but improved irrigation techniques could cut this waste to 5-20%.

Center-pivot, low pressure sprinklers sprays water directly onto crop.

It allows 80% of water to reach crop.

Has reduced depletion of Ogallala aquifer in Texas High Plains by 30%.

Water Waste

Many poor farmers in developing countries use low-tech methods to pump groundwater and make more efficient use of rainfall.

Solutions: Getting More Water for Irrigation in Developing Countries – The Low-Tech

Approach

We can reduce water use and waste by raising the price of water while providing low lifeline rates for the poor.

When Boulder, Colorado introduced water meters, water use per person dropped by 40%.

A 10% increase in water prices cuts domestic water use by 3-7%.

Reducing Industrial Water Waste

Stricter laws provide incentive to conserve water

Recycling water within the plant

Water scarcity (in addition to stricter pollution control requirements) will encourage further industrial recycling

Potential to conserve water is huge!

Water Conservation

Xeriscape: Landscape yards with plants that require little water

Agenda:

1. Finish Notes from Yesterday

2. 3 Gorges Dam Case Study/Recap HWK (2 minutes to respond) –letsrecap.com Code-ixctccw

**There is no PAWS this Thurs—So if you scheduled to makeup a test you will have to do it today or next Tuesday **

I need to know if you DO NOT plan on taking the AP Exam, #’s are due soon. There is a sign on the door for you to sign up by next Monday

APES 3/7

Part 2: Water Pollution & Sewage

WATER POLLUTIONWater pollution is any chemical, biological, or physical change in

water quality that has a harmful effect on living organisms or makes water unsuitable for desired uses.

Types of water pollution

A. Inorganic and algal nutrients

B. Sediment pollution

C. Organic Compounds

D. Inorganic compounds

E. Radioactive Substances

F. Thermal Pollution

G. Sewage

A. Inorganic and Algal Nutrients• Chemical – N and P fertilizers

• Sources

• Agriculture

• Human and animal waste

• Plant residue

• Cultural Eutrophication

• Algal bloom – algae die

• bacterial decomposition uses dissolved oxygen(DO)

• High Biological oxygen demand ( BOD)

Happy Pond

Emergent Aquatic Vegetation

Submerged Aquatic Vegitation

Sun for Photosynthesis

Aquatic life

AlgaeDO - High

BOD - Low

Addition of Pollutants

Geese

Fertilizers

nitrates

phosphates

Algae feed on excess nutrients

Algal Bloom - block sun

Plants cannot

Photosynthesize

Fish gasp for air

Fish Kill

DO - Low

BOD - High

Gulf of Mexico Hypoxic Zone

• Large as state of New Jersey

• Fertilizer runoff to Mississippi River

• Animal feedlot waste runoff = untreated

Oxygen Depletion in the Northern Gulf of Mexico

A large zone of oxygen-depleted water forms for half of the year in the Gulf of Mexico.

POLLUTION OF STREAMS

Flowing streams can recover from a moderate level of degradable water pollutants if they are not overloaded and their flows are not reduced.

In a flowing stream, the breakdown of degradable wastes by bacteria depletes DO and creates an oxygen sag curve.

This reduces or eliminates populations of organisms with high oxygen requirements.

Dilution and decay of degradable, oxygen-demanding wastes and heat in a stream.

Major Water Pollutants & Effects

Warmer water holds less Oxygen

Water quality and dissolved oxygen (DO) content in parts per million (ppm) at 20°C.

Only a few fish species can survive in water less than 4ppm at 20°C.

B. Sediment Pollution

Sand, silt, clay, gravel

Excessive suspended particles from erosion

Agricultural lands

Deforested areas

Overgrazed rangelands

Strip mines

Construction sites

Turbidity

Less light = less photosynthesis = less DO

Clogs up coral reefs

Sediments can carry toxic compounds

C. Organic Compounds ( C ) Most are synthetic Pesticides i.e aldicarb (insecticide) (attacks nervous system)

Solvents i.e. benzene (blood disease, leukemia)

Plastics i.e. PVC polyvinyl chloride (cancer)

Industrial i.e. PCB polychlorinated biphenyl - chlorine (liver and kidney disease)

Detergents

HOW?? Seep from landfills

Leach into soil from farms

Runoff

Dumped directly by industry

Oil spills

Improperly disposed of household hazardous waste

Measured in ppm or ppb

D. Inorganic Chemicals

Acids, bases, salts, heavy metals

Acids used in industrial processes and separating certain minerals from ore

Acid rain

PERSIST – do not break down in nature

Pesticide and fertilizer residues

Incinerator ash go to landfills – leachate

Salts-

Includes arsenic

Evaporation = increased salt concentration

LEAD Lead based paint banned

in 1978 but ¾ of homes still have some lead paint

Lead pipes

Leaded gas banned in 1986 – gets in atmosphere then settles

High levels near highways and in cities

Mercury Expensive to control mercury emissions

Not mandated by Clean Air Act

*Coal powered power plants to atmosphere to water

Incinerators ( municipal and medical) Batteries, flourescent lights, paint, plastics

Smelting of lead, copper, zinc

Minimata disease

neurological syndrome caused by

severe mercury poisoning

Once in water – settles and enters

food web

Bioaccumulation in muscle

Tuna, swordfish, sharks

E. Radioactive substances Unstable isotopes that emit radiation as they break

down

Radon = natural gas in crust

Dissolves in groundwater

F. Thermal pollution

• Water used as coolant and released

• As temp increases

• Speeds up decay = increases BOD

• Lowers DO

• Affects marine life

G. Sewage – what’s that smell?

Sewage: wastewater from sewers/ drains

Human waste, soap, detergents,

Nutrients – lead to cultural eutrophication

Disease causing agents From human and animal excrement

Escherichia coli = E coli – found in intestines, feces

Monitoring done with Fecal Coliform Test pass through filter to capture e coli bacteria

incubate in petri dish = colonies

Drink water = 0-1 colonies/100ml

Swim water = 200 colonies/100ml

Raw sewage = millions of colonies

Table 21-2, p. 495

Sewage Treatment

Raw sewage reaching a municipal sewage treatment plant typically undergoes:

Primary sewage treatment: a physical/mechanical process that uses screens and a grit tank and filter to remove large floating objects and allows settling.

Secondary sewage treatment: a biological process in which aerobic bacteria remove as much as 90% of dissolved, biodegradable, oxygen demanding organic wastes. Often includes a disinfection process

Fig. 21-16, p. 511

Raw sewagefrom sewers

Activated sludge

Disposed of in landfill or ocean or applied to cropland,pasture, or rangeland

Primary Secondary

Grit chamberBar screen Settling tank Aeration tank Settling tankChlorinedisinfection tank

Sludge drying bed

Sludge digester

Air pump

To river, lake,or ocean

(kills bacteria)

Sludge

Oil, fat, sand, gravel, toys, floaters,

rags, settled poop

Bacteria, Aerobic digestion (need O) of

human waste and other organics,

flocculation, disinfection

Disinfection: chlorine

or ozone, or UV

aeration

Settling tanks

Treated wastewater

outflow

Tertiary Sewage Treatment

Advanced or tertiary sewage treatment:

Uses series of chemical and physical processes to remove specific pollutants left (especially nitrates and phosphates).

Water is chlorinated to remove coloration and to kill disease-carrying bacteria and some viruses (disinfect). (AFTER 1 & 2 and/or 3rd step of sewage treatment)

Sewage Sludge

Sewage sludge can be used as a soil conditioner but this can cause health problems if it contains infectious bacteria and toxic chemicals.

Anaerobic digestion – 4-6 weeks = fertilizer

Compost – mix with woodchips, expose to air = humus

Pasteurization – heat to kill pathogens = fertilizer pellets

Preventing toxic chemicals from reaching sewage treatment plants would eliminate such chemicals from the sludge and water discharged from such plants.

Sewage sludge aka biosolids

Alfalfa field fertilized with sewer sludge

Septic System

small-scale sewage treatment system common in areas with no connection to main sewage pipes provided by local governments or private corporations.

generally limited to rural areas. Since a septic system requires a drain field that uses a lot of land area, they are not suitable for densely built cities.

Wetlands can be a Natural sewage treatment process

Natural and artificial wetlands and other ecological systems can be used to treat sewage.

California created a 65 hectare wetland near Humboldt Bay that acts as a natural wastewater treatment plant for the town of 16,000 people. The project cost less than half of the estimated price of a conventional

treatment plant.

Wetlands improve water quality

Microbes live in wetlands – break down organics

Vegetation slows water movement – allows sedimentation

Fig. 21-8, p. 502

Water well

Migrating vapor phase

Contaminant plume moveswith the groundwater

Free gasolinedissolves ingroundwater(dissolved phase)

Groundwaterflow

Watertable

Gasolineleakage plume(liquid phase)

Leakingtank

POLLUTION OF GROUNDWATER

Leaks from a number of sources have contaminated groundwater in parts of the world.

According the EPA, one or more organic chemicals contaminate about 45% of municipal groundwater supplies.

By 2003, the EPA had completed the cleanup of 297,000 of 436,000 underground tanks leaking gasoline, diesel fuel, home heating oil, or toxic solvents.

Case Study: Arsenic in Groundwater

Toxic Arsenic (As) can naturally occur at high levels in soil and rocks.

Drilling into aquifers can release As into drinking water supplies.

According to W.H.O., more than 112 million people are drinking water with As levels 5-100 times the 10 ppb standard.

Mostly in Bangladesh, China, and West Bengal, India.

Prevention

• Find substitutes for toxic chemicals

• Keep toxic chemicals out of the environment

• Install monitoring wells near landfills and underground tanks

• Require leak detectors on underground tanks

• Ban hazardous waste disposal in landfills and injection wells

• Store harmful liquids in aboveground tanks with leak detection and collection systems

Cleanup

• Pump to surface, clean, and return to aquifer (very expensive)

• Inject microorganisms to clean up contamination (less expensive but still costly)

• Pump nanoparticles of inorganic compounds to remove pollutants (may be the cheapest, easiest, and most effective method but is still being developed)

Solutions for Groundwater Pollution

OCEAN POLLUTION

• Oceans, if they are not overloaded, can disperse and break down large quantities of degradable pollutants.

• All runoff leads to the sea ---the Great Pacific Garbage Patch?

• Pollution of coastal waters near heavily populated areas is a serious problem.

Fig. 21-10, p. 505

Healthy zoneClear, oxygen-richwaters promote growthof plankton and sea grasses,and support fish.

Oxygen-depleted zoneSedimentation and algaeovergrowth reduce sunlight,kill beneficial sea grasses, useup oxygen, and degrade habitat.

Red tidesExcess nitrogen causesexplosive growth of toxicmicroscopic algae,poisoning fish andmarine mammals.

FarmsRunoff of pesticides, manure, and fertilizers adds toxins and excess nitrogen and phosphorus.

Toxic sedimentsChemicals and toxic metals contaminate shellfish beds, kill spawning fish, andaccumulate in the tissues of bottom feeders.

Construction sitesSediments are washed intowaterways, choking fish and plants, clouding waters, and blocking sunlight.

Urban sprawlBacteria and viruses fromsewers and septic tanks contaminate shellfish beds

Oxygen-depletedzone

Closedbeach

CitiesToxic metals and oil from streets and parking lots pollute waters;

IndustryNitrogen oxidesfrom autos andsmokestacks,toxic chemicals,and heavy metals in effluents flow into bays and estuaries.

Closedshellfish beds

OCEAN OIL POLLUTION

• Most ocean oil pollution comes from human activities on land.

Studies have shown it takes about 3 years for many forms of marine life to recover from large amounts of crude oil (oil directly from ground).

Recovery from exposure to refined oil (fuel oil, gasoline, etc…) can take 10-20 years for marine life to recover.

Exxon Valdez Oil Spill March 24, 1989…. ran aground

Prince William Sound, AK… pristine area

11,000,000 gallons

20% evaporated

50% deposited on shoreline

14% skim and waste recovery

$3 billion clean up cost

Pressure washers

Prevention Reduce input of toxic

pollutants

Separate sewage and storm lines

Ban dumping of wastes and sewage by maritime and cruise ships in coastal waters

Ban ocean dumping of sludge and hazardous dredged material

Protect sensitive areas from development, oil drilling, and oil shipping

Regulate coastal development

Recycle used oil

Cleanup

Improve oil-spill cleanup capabilities

Sprinkle nanoparticles over an oil or sewage spill to dissolve the oil or sewage without creating harmful by-products

Require at least secondary treatment of coastal sewage

Use wetlands, solar-aquatic, or other methods to treat sewage

Solutions to Coastal Water Pollution

PREVENTING AND REDUCING SURFACE WATER POLLUTION

• The key to reducing nonpoint pollution – most of it from agriculture – is to prevent it from reaching bodies of water.

• Farmers can reduce runoff by

• planting buffers

• locating feedlots away from

steeply sloped land, flood zones,

and surface water.

Kansas

Water Pollution Must-Know Laws 1948 Water Pollution Control Act

1972 Clean Water Act – EPA

Make all water swimmable and fishable

requires permit for discharge

Identifies toxins and requires BEST technology to remove

Sets goals for best available tech development

Sets max permissible pollutants

Water Pollution Laws cont 1974 – Safe Drinking Water Act

EPA regulates quality and safety of drinking water

Sets standards

Determines max contaminant levels

1987 Water Quality Acts

Established water purity standards

1988 Ocean Dumping Ban Act

Unlawful to dump sewage, sludge, industrial waste

1976 resource conservation & recovery act

RCRA = regulates storage and disposal of hazardous wastes –helps protect groundwater

DRINKING WATER QUALITY

• Centralized water treatment plants and watershed protection can provide safe drinking water for city dwellers in developed countries.

• Simpler and cheaper ways can be used to purify drinking water for developing countries.

• Exposing water to heat and the sun’s UV rays for 3 hours can kill infectious microbes.

Is Bottled Water the Answer?

Most bottled water is not as pure as tap water and costs much more.

• 1.4 million metric tons of plastic bottles are thrown away.

• Fossil fuels are used to make plastic bottles.

• The oil used to produce plastic bottles in the U.S. each year would fuel 100,000 cars.

• Fossil fuels are also used to transport and cool water bottles

“Tapped” Trailer (5:41): https://youtu.be/72MCumz5lq4