Inspiration Rain

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Chapter 5 Water
All is born of water, all is sustained by
water. Johann Wolfgang von Goethe German Poet
and Dramatist
Powerpoint Templates
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5.1 Our Water Resources

• Much of our water we drink today has been around
  since water first formed on Earth billions of
  years ago
• Clean, fresh water is essential to life and is
  critical to human health
• People can survive for more than a month without
  food can only life for a few days without water
• Two kinds of water are found on EarthFresh water
  (water people can drink, contains little salt)
  and Salt water (water in the oceans, contain
  higher concentrations of dissolved salts)
• People live longer today because we have clean
  water (to drink, to bathe in, to wash with, to
  irrigate crops and to flush away sewage)

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The Water Cycle

• Earth is called the water planet because of the
  abundance of water (solid, liquid and gas)
• Water is renewable endlessly circulated through
  the water cycle
• In the water cycle, water molecules travel
  between Earths surface and the atmosphere.
  (water evaporates, leaves behind salts and other
  impurities water vapor rises into the air gas
  cools and condenses into drops of liquid water
  that form clouds water falls back to Earth and
  replenishes Earths fresh water supply)

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Global Water Distribution

• About 71 of Earths surface is covered by water
• 97 of that water is salt water, in oceans and
  seas
• 3 is fresh water 77 of that is frozen in
  glaciers and polar icecaps leaving only a
  fraction of the freshwater for human use
• The water we require for our everyday needs
  (agriculture and drinking) comes mainly from
  lakes and rivers and from a relatively narrow
  zone beneath the Earths surface.

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Surface Water

• Surface water is fresh water on Earths land
  surface (lakes, rivers, streams, wetlands)
  however, that distribution has played a vital
  role in the development of human societies.
• Surface water makes up a small fraction of
  Earths fresh water
• Most large cities depend on surface water (fresh
  water that is above ground in lakes, ponds,
  rivers and streams) for drinking water, water to
  grow crops, food such as fish and shellfish,
  power for industry, transportation by boat

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River systems

• All rivers are a result of precipitation rain
  falls, snow melts (from mountains, hills,
  plateaus and plains)
• The more streams that run into a river, the
  larger the river becomes
• As streams and rivers move across the land, they
  form a flowing network of water called a river
  system viewed from above, it would look like the
  roots of a tree feeding into the truck
• The Mississippi, the Amazon and the Nile are
  enormous river systems The Amazon River systems
  is the largest in the world (drains an area
  nearly the size of Europe!)
•  

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Watersheds

• Area of land that is drained by a river is its
  watershed amount of water that falls on a
  watershed varies from year to year
• Pollution anywhere in a watershed may end up
  polluting a river
• Lakes provide a more stable water source rapidly
  melting snow and spring and summer rains can
  dramatically increase amount of water in a
  watershed
• Communities that depend on rivers for water can
  be severely affected by changes in river systems
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Groundwater

• Most of the fresh water that is available for
  human use cannot be seen---it exists underground
• Not all rain flows into lakes and streams plants
  use some the water, most seeps underground
• Water percolates through the soil and down into
  the rocks beneath water stored beneath Earths
  surface in sediment and rock formations is called
  groundwater.
• The water table is where the rocks and soil are
  saturated with water in wet regions, the water
  table may be at the Earths surface and a spring
  of fresh water may flow out onto the ground in
  deserts, the water table may be hundreds of
  meters beneath Earths surface

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Aquifers

• Large amounts of water is found underground in
  rock formations called aquifers (consist of
  rocks, sand, gravel with lots of air space where
  water can accumulate)
• Aquifers continuously receive water that
  percolates down from the surface (very slow
  process)
• Holds water in the same way a sponge holds water
• Groundwater can dissolve rock formations
  (limestone) and fill vast caves with water,
  forming underground lakes
• Important sources of water for many cities and
  for agriculture

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Porosity and Permeability

• Most rock appears to be solid however, many
  kinds of rocks contain small holes, or pore
  spaces
• Porosity is the amount of space between the
  particles that make up a rock
• Water in aquifers is stored in the pore spaces
  and flow from one pore to the next the more
  porous the rock, the more water it holds
• Permeability is the ability of rock or soil to
  allow water to flow through it (ex gravel)
• Impermeable - stops the flow of water (clay,
  granite)
• Most productive aquifers form in permeable
  materials (sandstone, limestone, layers of sand,
  gravel)

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The Recharge Zone

• Area of land from which groundwater percolates
  down into the aquifer is called the recharge zone
  (through soil and rocks) takes an extremely long
  time to refill an aquifer (tens of thousands of
  years)
• Recharge zones are environmentally sensitive
  areas because pollution can enter the aquifer
  buildings, parking lots (impermeable layers) can
  reduce the amount of water entering an aquifer
• Communities need to carefully manage recharge
  zones

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Wells

• If you dig deep enough, you will find water
• Dig deep into the ground to reach water wells
  may be a more reliable source of water because it
  is filtered and purified as it travels through
  all the layers
• Height of water tables changes seasonally, so
  wells are dug to extend below the water table
• If water table falls too low or is removed faster
  than it can be recharged, the well must be dug
  deeper
• Problem People are pumping out water faster
  than it can be replaced naturally consequently,
  water levels are dropping rapidly
• Ogallala Aquifer (western US) is being depleted
  rapidly
• Some communities who once depended on aquifers
  are now using other sources of fresh water

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5.2 Water Use and Management

• We all live downstream. What does it mean??
  When a water supply is polluted or overused,
  everyone living downstream is affected.
• Number of people relying on freshwater is
  increasing daily
• One of Earths most pressing environmental
  problems is a shortage of clean, fresh water
• According to the World Health Organization, more
  than 1 billion people lack access to a clean
  source of fresh water

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Global Water Use

• Three major uses for water residential,
  agricultural, and industrial
• Most fresh water worldwide is used to irrigate
  crops
• Availability of fresh water, population size and
  economic conditions affect how people use water
  patterns of water use are not the same everywhere
  (Asia 80, Europe 38)
• Industrial use accounts for 19 highest
  percentage of use in Europe and North America
• About 8 is used by households for drinking and
  washing

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Residential Water Use

• Major differences in water use throughout the
  world average person in US uses about 300 L (80
  gal) of water per day, half used for inside the
  home for drinking, washing, cooking and personal
  needs, the other half is used outdoors for
  watering lawns and washing cars India uses about
  41 L per day

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Water Treatment

• Most water needs to be treated to make it potable
  (safe to drink) removes elements (mercury,
  arsenic, lead) which are poisonous to humans in
  low concentrations (found in polluted water but
  can also be found naturally in groundwater)
• Also removes pathogens (organisms that cause
  illness or disease bacteria, viruses, protozoa,
  parasitic worms) found in water contaminated by
  sewage and animal feces
• Several methods of treating water (both physical
  and chemical treatment)

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Industrial Water Use

• Industry accounts for 19 of water used in the
  world manufacturing goods, disposal of waste,
  generating power
• Nearly 1000 L of water is needed to produce 1 kg
  of aluminum 500,000 L of water is needed to
  manufacture a car vast amounts of water is used
  to produce computer chips and semiconductors
• Mostly used to cool power plants (pump water from
  a surface water source, a river or lake, carry
  that water through pipes in a cooling tower, and
  then pump the warmer, generally clean water back
  into the original source)

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Agricultural Water Use

• Agricultural use accounts for 67 of the water
  used in the world nearly 300 L (80 gal) of water
  to produce 1 ear of corn
• Plants require a lot of water 80 of the water
  used to water plants never reaches the plant
  roots, it evaporates

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Irrigation

• Fertile soil oftentimes found in areas with
  little rainfall so extra water must be supplied
  by irrigation
• Irrigation is a method used to provide plants
  with water from sources other than direct
  precipitation (earliest forms of irrigation
  involved flooding the fields)
• Many forms of irrigation are used today, ex
  shallow, water-filled ditches (cotton), high
  pressure overhead sprinklers (inefficient because
  nearly ½ evaporates and never reaches roots
• Newer, more efficient methods are becoming more
  common

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Waste Management Projects

• For thousands of years, humans have altered
  streams and rivers to make them more useful
• Nearly 2000 years ago, Romans built aqueducts
  (huge canals from mountains to dry areas) some
  are still used today today, modern engineering
  has allowed water projects to become more complex
• Water management projects (dams and water
  diversion canals) allow people to live in
  desirable areas where surface water is
  inadequate, or to create reservoirs for
  recreation or drinking water, and to generate
  electric power
• Piped in water allows people to live and grow
  crops in Southwest US (desert areas)
•  

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Water Diversion Projects

• All or parts of rivers can be diverted into
  canals to provide water to dry regions, ex
  Owens River in California provides drinking water
  to Los Angeles Colorado River provides water to
  7 states
• Colorado River (flows 1450 miles) begins as a
  glacial stream in the Rocky Mountains, grows
  larger as of the streams feed into it then
  divided to meet the needs of the states so much
  of the water is diverted for irrigation and
  drinking water that it runs dry before it ever
  reaches Mexico and the Gulf of California (only
  makes it there in the wettest years)
• River water is in high demand disputes over who
  have rights to it occur often (ex Colorado
  River)
• 40 of worlds people rely on water that
  originates in another country conflicts over
  water rights, especially when dams are built
  restricting flow to other countries downstream
  are common
• Disputes over water rights is likely to become
  more common as populations increase and demand
  for fresh water increases

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Dams and Reservoirs

• Structures built across a river to restrict the
  flow of water downstream and form a reservoir
  (artificial lake formed behind the dam)
• Water is used for drinking, irrigation,
  manufacturing, flood control, electricity and
  recreation
• Hydroelectric dams use the power of flowing water
  to turn a turbine that generates electrical
  energy about 20 of the worlds electricity is
  generated by hydroelectric energy
• Mixed blessing artificial lake destroys existing
  ecosystems when they are formed and disrupts
  ecosystems downstream when they get less water
  people are displaced from their homes (close to
  50 million people worldwide) farmland below a
  dam is affected as a result of nutrient rich
  sediment being blocked behind the dam rather than
  flowing downstream
• Dams can malfunction and burst, killing many
  people below the dam
• No additional dams being built in US but will
  probably continue in developing countries
  (Brazil, India and China)

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Water Conservation

• As water sources become depleted, water becomes
  more expensive
• Water conservation is one way people will have
  enough water at reasonable prices

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Water Conservation in Agriculture

• Most water loss in agriculture comes from
  evaporation, seepage and runoff
• Drip irrigation systems offer an initial step
  toward conservation (deliver small amounts of
  water directly to plant roots by using perforated
  tubing, released as needed at a controlled rate)
  managed by computer programs very little loss of
  water to evaporation, seepage or runoff

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Water Conservation in Industry

• Industries have developed water conservation
  plans due to the rising cost for water
• Most conservation practices involve recycling of
  cooling water and wastewater instead of
  returning water to rivers, businesses recycle the
  water and reuse it (ex production of paper uses
  less than 30 of the water required to produce
  the same amount of paper as 50 years ago)
• In Denver, Colorado, the city pays small
  businesses to introduce water conservation
  methods saves money for the city and the
  businesses and makes more water available for
  agriculture and residential use.

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Water Conservation at Home

• Households use much less water than agriculture
  and industry, however, people can make a
  difference by changing a few everyday habits
  (using low flow toilets and shower heads, water
  lawns at night, take shorter showers don't run
  water while brushing your teeth, wash only full
  loads of laundry and dishes)
• Xeriscaping - designing landscapes that require
  minimal water use
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Solutions for the Future

• Conservation alone is not enough to prevent water
  shortages, other sources of fresh water needs to
  be developed
• Two possible solutions Desalination and
  transporting fresh water

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Desalination

• Desalination is the process of removing salt from
  saltwater desalination plants heat salt water
  and collect the fresh water that evaporates
• Some coastal communities rely on the oceans to
  provide fresh water and have built desalination
  plants (Middle East)
• Desalination consumes a lot of energy, the
  process is too expensive for many nations to
  consider

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Transporting Water

• In areas where freshwater resources are not
  adequate, water can be transported from other
  regions (ex Greece, high tourist area, not
  enough fresh water to handle residents and
  tourists so large ships towing enormous plastic
  bags of water travel regularly to the Greek
  Islands to pump fresh water)
• This is a solution the US is considering, too.
  (Alaska has 1/2 the available fresh water tow
  Alaskan water down the Californian coast)
• With 76 of Earth's fresh water in frozen
  icecaps, people have considered towing icebergs
  to communities needing fresh water however,
  efficient ways to tow the icebergs is yet to be
  discovered

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5.3 Water Pollution

• You cannot always determine if water is polluted
  by the way it looks or smells there are
  different forms of water pollution (chemical,
  physical or biological agents)
• The introduction of these agents can adversely
  affect the water quality and the organisms that
  depend on the water
• There are two underlying causes of water
  pollution industrialization and rapid human
  population growth
• In the past 30 years, developed countries are
  making provisions to clean up polluted water
  supplies however, many sources continue to be
  dangerously polluted
• Water pollution continues to be a big problem in
  developing countries industry is NOT the major
  cause of pollution in those countries
• Available drinking water in these countries is
  polluted with sewage and agricultural runoff
  (spreading waterborne diseases)
• People must understand where pollutants come from
  in order to prevent water pollution comes from
  two main sources point and non-point

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Point Pollution

• Pollution that is discharged from a single source
  (ex factory, waste treatment plant, oil tanker)
• Relatively easy to regulate and control because
  it is easily identified and traced
• Hard to enforce clean-up

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Nonpoint Pollution

• Comes from many sources rather than from a single
  specific site reaches bodies of water via
  streets and storm sewers (ex homes, lawns,
  farms, highways, also from pesticides,
  fertilizers, animal feces)
• Extremely difficult to regulate and control
• Small amounts add up to a huge pollution problem
  96 of polluted bodies of water come from
  nonpoint pollution contamination
• Public awareness and education will probably be
  the most effective way of reducing nonpoint
  pollution
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Wastewater

• Water that goes down a drain ends up in a
  wastewater treatment plant
• Wastewater is water that contains waste from
  homes and industry
• At a wastewater treatment plant, the water is
  filtered and treated then it is returned to a
  river or lake
•  

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Treating Wastewater

• Home wastewater is biodegradable and can be
  broken down by living organisms (ex toilet and
  kitchen wastewater contains animal and plant
  waste, paper and soap all are biodegradable)
• However, some home, industrial and storm runoff
  may contain toxic substances that interfere with
  treatment and cannot be removed by the standard
  treatment

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Sewage Sludge

• By-product of wastewater treatment is sewage
  sludge (solid materials that remains after
  treatment) many contain toxic chemicals
  incinerated and then buried
• Non-toxic sludge can be used as fertilizer
  (contain plant nutrients) if it is free of
  toxins can be made into bricks when combined
  with clay

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Pathogens

• Disease causing organisms (bacteria, viruses,
  parasitic worms)
• Can enter water supplies in untreated wastewater
  or animal feces
• Cholera, hepatitis, typhoid are diseases people
  can get from drinking water containing these
  pathogens
• Public water supplies are constantly monitored
  for the presence of these pathogens.

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Artificial Eutrophication

• Most nutrients in water come from organic matter
  (leaves, animal waste) it is broken down into
  mineral nutrients by decomposers (bacteria,
  fungi)
• An overabundance of nutrients can disrupt the
  ecosystem (eutrophic)
• Eutrophication is a natural process however, the
  addition of inorganic plant nutrients from
  fertilizer runoff and sewage (phosphorous and
  nitrogen, ex laundry detergents, dishwashing
  soap, lawn fertilizers) causes excessive growth
  of algae (algal blooms) which die and when they
  decompose use large amounts of dissolved oxygen
  in the water fish suffocate and die (artificial
  eutrophication)
• Some states are now banning phosphate detergents
  others have limited the amount of phosphates in
  the detergents

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Section 5.4 Thermal, Groundwater and Ocean
Pollution

• Thermal Pollution
• Excess amount of heat added to the water creates
  thermal pollution from power plants and
  industries use the cool water to circulate in
  their engines and then return the warmed water to
  the lake or river
• Can kill large quantities of fish when it is too
  warm warm water holds less oxygen depriving
  organisms of oxygen constant influx of warm
  water disrupts the ecosystem
• Citizens are usually opposed to new construction
  of power plants

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Groundwater Pollution

• Pollutants usually enter groundwater when
  polluted surface water percolates down from
  Earths surface.
• Likely to plague us for centuries to come
  (petroleum products, pesticides, herbicides,
  fertilizers, and agricultural chemicals are
  common pollutants)
• Leaking underground storage tanks also contribute
  and are a major source of groundwater pollution
  (located beneath gas stations, farms and homes
  hold products like gasoline and heating fuel as
  they age, they develop leaks which seep into
  groundwater)
• EPA has detected at least 200 hazardous chemicals
  that can seep through the soil and into
  groundwater location of many tanks is unknown so
  they cannot be repaired or replaced until they
  have leaked enough pollutants to be located
  modern underground storage tanks are contained in
  concrete
• Other sources of groundwater pollution include
  septic tanks, unlined landfills, industrial
  wastewater lagoons

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Cleaning Up Groundwater Pollution

• One of the most challenging environmental
  problems that the world faces today.
• Even if we were to stop polluting the groundwater
  today, the water would remain polluted for
  generations to come groundwater recharges very
  slowly (hundreds or thousands of years)
• Very difficult to decontaminate, water is
  dispersed throughout large areas of rock and
  sand, pollutants cling to materials that make up
  an aquifer
•  

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Ocean Pollution

• How much pollution can the oceans absorb?
  Sailors have reported a river of polystyrene
  that stretches across the ocean from Bermuda to
  the African coast.
• How long will it take to decompose?
• Where does it come from?

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How Pollutants Get Into Oceans

• At least 85 of ocean pollution (oil, toxic
  wastes and medical wastes) comes from activities
  on the land (most occurring near the coastline)
  harms sensitive coastal ecosystems like coral
  reefs and estuaries the most
• Pollution entering rivers flows to the ocean
• Pollutants are dumped directly into the oceans
  (sludge from wastewater treatment and garbage)
•  

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Oil Spills

• Accidental oil spills, account for only 5 (Exxon
  Valdez, 1989, in Prince William Sound, Alaska
  2001 a fuel-oil spill occurred off the coast of
  the Galapagos Islands)
• Every year, about 37 million gallons of oil
  spills into the ocean
• Most oil that pollutes oceans comes from cities
  and towns (200 to 300 million gallons enter from
  nonpoint sources)

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Water Pollution and Ecosystems

• Biological magnification starts at the level
  where a toxin enters the ecosystem bottom
  dwelling organisms enter their bodies-gt eaten by
  small fish -gt eaten by large fish -gt eagle
• The toxin increases in concentration from one
  tropic level to the next
• Polluted water may also cause an immediate change
  in the ecosystem killing nearly all things for
  miles downstream
• Harmful to humans harmful to fish (cancers,
  scale rot, fin rot) or accumulate in fish tissue
  making them dangerous for humans to consume
  (birth defects, reproductive, nervous system,
  liver, kidney damage)

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Preventing Ocean Pollution

• MARPOL prohibits the discharge of oil and
  disposal or abandonment of plastic in oceans or
  coastal water
• 1974 Helsinki Convention seeks to control
  land-based sources of ocean pollution (toxic
  dumping DDT, cadmium, mercury) and raw
  wastewater
• US is strengthening its laws 1990 (Marine Mammal
  Protection Act) requiring ships have double hulls
• Problem It is difficult to monitor every ship in
  the ocean

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Who Owns the Oceans?

• Who has jurisdiction over the oceans? In the
  past, international law allowed nations to
  control the water extending out 3 miles from the
  coast rest of the ocean was high seas and open
  to everyone
• Now, Law of Sea Treaty extends out 12 nautical
  miles (22 km) or its territorial sea and then
  another 370 km (200 nautical mi) or its exclusive
  economic zone (environmental preservation and
  research) the rest is communal
• US did not sign treaty (didnt like restrictions
  on seabed mineral mining)

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Cleaning Up Water Pollution

• Congress has passed several laws designed to
  improve water quality in the US
• In 1969, Cuyahoga River in Cleveland, OH was so
  polluted the river caught on fire and burned for
  several days this event was the major factor in
  the passage of the1972 Clean Water Act
  restore and maintain the chemical, physical and
  biological integrity of the nations waters.
  Goal was to make all surface water clean enough
  for fishing and swimming by 1983 (not achieved,
  but increased by 30)
• 1972 - Marine Protection, Research and
  Sanctuaries Act (strengthened laws against ocean
  dumping)
• 1975 Safe Drinking Water Act
• 1980 Comprehensive Environmental Response
  Compensation and Liability Act
• 1987 Water Quality Act
• 1990 Oil Pollution Act (requires oil tankers
  traveling in US waters to have double hulls by
  2015)
• They were able to succeed in curbing point
  pollution, but non-point pollution continues to
  be a problem
•  

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Bottled Water

• Many people have opted to drink more bottled
  water than tap because they feel it is safer to
  drink
• Most bottled water comes from the tap that is
  filtered and treated with various chemicals
• Bottled water is regulated by the government but
  is NOT tested for pollutants as often as the
  public water supply is tested