Water Resources and Water Pollution Lecture Powerpoint

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					        Water: Resources and Pollution




"Water will be more important than oil this century.”
- Former U.N. Secretary General Boutros Boutros Gali
                                                        1
    Great Plan for the Transformation of Nature

•   During the late 1940s, Joseph Stalin
    proposed a plan in the Soviet Union
    to prevent a repeat of drought-
    caused famine in 1947 that killed
    nearly a million people.
•   A wide variety of ideas were
    implemented during the next two
    decades.


                                                  2
              Transformation of Nature

•   Windbreaks, or lines of trees, were built to
    reduce soil erosion.




            A windbreak built into a North Dakota Farm.
            Source: Wikimedia

                                                          3
             Transformation of Nature

•   A network of irrigation
    canals were built to
    divert water from two
    rivers into a desert
    region, to encourage
    the cultivation of crops
    such as rice, wheat,
    and cotton.
•   The rivers normally
    fed into the Aral Sea.
                                        4
                   The Aral Sea

•   In the 1950s, the Aral sea
    was one of the four
    largest lakes in the world,
    with an area of 26,300
    square miles.
•   The entire lake was part
    of the U.S.S.R., in the
    countries that today are
    Kazakhstan and
    Uzbekistan.
                                  5
                  Irrigation Canals

•   The irrigation canals were poorly built and
    uncovered, allowing about half of the water
    to evaporate or leak into the surrounding soil.
•   The Aral sea, deprived of its main water
    supply, began to shrink in 1961.


                                Satellite imagery of
                                the Aral Sea shrinkage
                                from 1961-2011.


                                                         6
                    Salination

•   The amount of water lost by
    the Aral Sea would completely
    fill Lakes Erie and Ontario.
•   The salinity of the remaining
    water has increased to 2-3x
    that of ocean water.
•   The drainage of the lake has    An abandoned ship in
                                    Aral, Kazakhstan.
    also exposed pesticides,
    herbicides, and other
    industrial pollutants on the
    bottom.                                                7
             Why is Water Important?

•   Necessary for all life to exist.
•   Next to antibiotics, single biggest increase in
    human life span is due to having access to
    clean water.
•   Diseases/toxins transmitted by contaminated
    water:
      Intestinal disease (cholera/dysentery)

      Arsenic poisoning

      Mercury poisoning


                                                      8
                   Hydrologic Cycle

•   The water on earth is continually recycled.
•   The hydrologic cycle describes this circulation:
    1. Water evaporates from wet land, lakes, or

       oceans and transpires from plants as they
       dry up.
    2. Enters the atmosphere, which is much

       colder, condenses and falls as
       precipitation.
    3. Moves underground by infiltration or runs

       off into rivers, lakes, or the ocean.
                                                       9
10
               Earth’s Water Budget


All water




Oceans and
saline lakes
97.4%




                                      Fig. 11-2, p. 238
               Earth’s Water Budget


All water




Oceans and
saline lakes
97.4%




                                      Fig. 11-2, p. 238
                     Earth’s Water Budget


All water                    Fresh water              Readily accessible fresh water
                                            Groundwater
                                              0.592%                             Biota
                                                                                 0.0001%
                                                                                        Rivers
                                                                Lakes                   0.0001%
                                                                0.007%
               Fresh water                        0.014%
                  2.6%                                                                 Atmospheric
Oceans and                   Ice caps
                                                                      Soil             water vapor
saline lakes                 and glaciers
                                                                      moisture         0.001%
97.4%                        1.984%
                                                                      0.005%




                                                                    Fig. 11-2, p. 238
       MAJOR WATER COMPARTMENTS
•   Groundwater
     Largest available (non-frozen) source of fresh

      water.
     Water moves underground through infiltration;

      percolation through the soil and into fractures
      and permeable rocks.
       - Zone of Aeration - Upper soil layers that hold

         both air and water.
       - Zone of Saturation - Lower soil layers where

         all spaces are filled with water.
       - Water Table - Top of Zone of Saturation

                                                          14
Infiltration




               15
                    Groundwater
•   Aquifers - Porous layers of sand, gravel, or
    rock lying below the water table.
      Aquifers are separate from groundwater;
       they are usually isolated by layers of rock.
      Artesian Well – Directly tapes into an
       aquifer as a source of water.




                                                      16
                  Groundwater
•   The recharge zone is an area where water
    infiltrates and refills an aquifer.
      Recharge rate is often very slow,
       depending on the size of the recharge
       zone and how often it rains there.




                                               17
    MAJOR WATER COMPARTMENTS CONT’D

•   Wetlands
     Play a vital role in hydrologic cycle.

      Wetlands have an unusually high amount
      of plant growth. Benefits include:
       - Stabilizes soil, preventing erosion

       - Slows down surface runoff, allowing

         more aquifer recharge.
       - Can hold excess water during flooding.




                                                  18
    MAJOR WATER COMPARTMENTS CONT’D
•   Rivers and Streams
     Formed from water that does not infiltrate,
      but runs off from surrounding land.
     May also be formed by melting glaciers.




                                    Each of the major
                                    rivers in Southeast
                                    Asia are fed by
                                    Himalayan glaciers.




                                                          19
    MAJOR WATER COMPARTMENTS CONT’D

•   The Atmosphere
     Among the smallest water reservoirs; only

      contains 0.001% of the total water supply.
     Has most rapid turnover rate. Water in the

      atmosphere does not remain there.
       - Redistributes water all over the earth.




                                                   20
                     Water Use

•   Consumption – Water that is withdrawn and
    no longer available for use because it has
    evaporated, been consumed by animals or
    plants, or discharged to a different location.




                                                     21
             Quantities of Water Used
•   Water use has been increasing twice as fast
    as population growth over past century.
      Worldwide, agriculture claims about 70%
       of total water withdrawal.
        - In many developing countries,
          agricultural water use is extremely
          inefficient and highly consumptive.
      Worldwide, industry accounts for about
       25% of all water use.
        - Cooling water for power plants is single
          largest industrial use.
                                                     22
Water Withdrawal




                   23
          FRESHWATER SHORTAGES

•   Areas that consume more water than
    typically falls as precipitation are considered
    to have water stress.




                                                      24
              A Precious Resource

•   Currently, 45 countries cannot meet the
    minimum essential water requirements of
    their citizens.
•   Will increase to 60 countries by 2050.




                                              25
              Depleting Groundwater

•   Groundwater is the source of nearly 40% of
    fresh water in the U.S.
•   Withdrawing water faster than it can be
    replenished leads to a cone of depression in
    the water table.
•   If this continues, the water table can be
    completely withdrawn.



                                                   26
Depleting Groundwater




                        27
          Depleting Groundwater Cont’d

•   Withdrawing large amounts of
    groundwater in a small area causes
    porous formations to collapse, resulting in
    subsidence.




                                                  28
        INCREASING WATER SUPPLIES

•   Seeding Clouds
    • Add silver iodide or dry ice to clouds

    • Inconsistent results




                                               29
        INCREASING WATER SUPPLIES

•   Towing Icebergs
     Cost

•   Desalination
     Removal of salt

      from ocean water
     Requires a high

      input of energy



                                    30
    INCREASING WATER SUPPLIES CONT’D

•   Dams, Reservoirs, and canals can be
    constructed to make the water supply more
    consistent or divert water to dry areas.
      This could result in the displacement of

       people, flooding of ecosystems.
      Evaporation rates increase as water is

       slowed.
      Any dissolved nutrients present in the water

       sink into the reservoir.

                                                  31
      Dams, Reservoirs, and Canals
 Displacement of People
   - Any villages present where the new
     reservoir will fill in must be evacuated.
   - The Three Gorges Dams in China will
     force relocation of over a million people.
 Evaporation, Leakage, Siltation

   - Evaporative losses from Lake Mead and
     Lake Powell on the Colorado River is
     about 1km3 per year (264 billion gallons).
   - Dams slow water flow, allowing silt
     (nutrients) to drop out.
                                                  32
          Dams, Reservoirs, and Canals
•   Loss of Free-Flowing Rivers
      Fish and other organisms will no longer be
       able to travel freely up and down that part of
       the river.




                                                    33
Evaporative losses from Lake Mead and Lake
Powell on the Colorado River is about 1km3
per year (264 billion gallons).
              Domestic Conservation
•   Estimates suggest many societies could
    save as much as half of current domestic
    water usage without great sacrifice or serious
    change in lifestyle.
      What are the biggest domestic uses of
       water?




                                                     35
                WATER POLLUTION

•   Any physical, biological, or chemical change
    in water quality that adversely affects living
    organisms can be considered pollution.
      Point Sources - Discharge pollution from

       specific locations.
        - Factories, power plants, oil wells

      Non-Point Sources - Scattered or diffuse,

       having no specific location of discharge.
        - Agricultural fields, feedlots, golf courses


                                                        37
              Heavy Metal Pollutants
•   Many metals such as mercury, lead,
    cadmium, and nickel are highly toxic.
•   They are highly persistent and tend
    to bioaccumulate in food chains.
•   Biggest sources:
      Mercury released from
       incinerators and coal-burning
       power plants.
      Mine drainage and leaching.




                                            38
            Other Inorganic Pollutants
•   Nonmetallic Salts
     Biggest source is road salt
      used during the winter.
     When the snow melts, the
      salt runs off into nearby
      rivers or lakes.
•   Acids and Bases
     Changes the pH of the
      water.
     Aquatic organisms are
      very sensitive to pH
      changes.                           39
                Organic Chemicals

•   Organic compounds are complex molecules
    that contain carbon.
•   Two most important sources of toxic organic
    chemicals in water are:
      Improper disposal of industrial and

       household wastes.
      Runoff of pesticides from private lawns and

       farms.


                                                     40
                Organic Chemicals

•   PCBs are one of the biggest and most
    persistent examples of organic chemical
    pollution
      Used for multiple electronic, wiring,

       adhesive, and lubrication applications.
•   PCBs are…
      Mutagenic

      Endocrine disruptors (mimic estrogen)

      Carcinogenic


                                                 41
This is a guide
to Lake
Michigan fish.

The fish with
the highest
level of
contamination
tend to be
larger or
bottom-
feeders.




                  42
                Sediment Pollution

•   Sediment is soil and rock particles that have
    entered water due to erosion.
•   Erosion is normal, but can be accelerated by
    human activities.
•   Sediment is beneficial (nourishes plants
    found in floodplains) in small amounts but
    can be harmful (smother aquatic life) when
    there is too much.


                                                    43
                 Thermal Pollution

•   Thermal pollution is dumping water into a
    river, lake, or sea that is either much warmer
    or much colder than normal.
      Oxygen levels in water decreases as

       temperatures increase.




                                                     44
            Groundwater Contamination

•   Groundwater is highly susceptible to pollution
    due to its location underground.
•   Example sources:
       - Leftover mining waste

       - Radioactive waste

       - Organic waste (manure)

       - Unsealed municipal waste (landfills)

       - Electricity generation waste (fossil fuels)

       - Oil and gas drilling

                                                       45
Groundwater Pollution




                        46
               Hydraulic Fracturing

•   Hydraulic fracturing, or “fracking”, is a
    controversial technique used to extract
    natural gas from rock formations that are not
    very permeable.
      Examples: Shale

     and coal beds.




                                                    47
               Natural Gas Deposits

•   Fracturing has become an increasingly
    popular tool for extracting natural gas,
    especially with the discovery of the methane-
    rich Marcellus Shale.




                                                    48
              The Fracturing Process

•   Fracturing fluid is pumped into a narrow hole
    drilled into the rock formation.
•   The pressure created from this fluid causes
    the rock formation to crack.
•   Sand is injected afterwards to fill the cracks,
    because it is more permeable and allows the
    methane to seep out.
      Most of the mixture injected into the rock

       formation is rock and sand, however…

                                                      49
                 Fracturing Fluid

•   A number of hazardous chemicals are also
    present in the fracturing fluid.
      These include carcinogens and endocrine

       disruptors.
      In a study published in 2010, the EPA

       discovered contaminants in groundwater.
      The gas industry claims that it is

       impossible for these fluids to enter
       groundwater.

                                                 50
              2005 Energy Policy Act

•   The EPA has been unable to investigate
    contamination due to fracturing for two
    reasons:
     1. The 2005 Energy Policy Act provides the

        industry exemption from the Clean Water
        and Drinking Water Acts.
     2. The specific chemicals used in fracturing

        are protected under copyright law as
        trade secrets.

                                                    51
        Incidents Resulting from Fracturing

•   Methane gas has entered drinking water
    supplies in Dimock, PA.
      Caused a water well explosion.

•   A well explosion in Clearfield, PA sent
    35,000 gallons of fracturing fluid into the
    surrounding forests.
•   Another well in Leroy, PA experienced a leak
    and entered the groundwater.


                                                   52
                 Impaired Waters

•   Impaired waters are rivers, lakes, and
    estuaries that cannot fully support their
    aquatic biological communities.
•   Top three causes:
      Excess sediment

      Nutrients (nitrogen and phosphorous)

      Pathogenic microorganisms




                                                53
                         Water Quality Today




Source: US EPA
http://pubs.usgs.gov/fs/FS-130-01/             54
             Water Testing Standards

•   The EPA requires that local water treatment
    plants provide yearly reports to residents
    listing any contaminants found in the drinking
    water supply.
•   Must be tested for microbes several times a
    day.
      Bottled water has much less strict

       requirements.


                                                     55
                     Tap Water Quality




                                                   56
Source: Environmental Working Group; www.ewg.org
          Local Tap Water Contaminants

•   Chlorine treatment byproducts –
    Bromodichloromethane,Dibromochloromethane,
    haloacetic acids, bromoform, chloroform
     Formed when chlorine reacts with organic
      matter found in water.
     Legal limit for these pollutants is 100 parts

      per billion.
     LD50 of chloroform is about 900mg/kg.




                                                      57
                   Bottled Water?

•   Spring water – From an underground source.
•   Purified water – Treated with distillation,
    ozonation, or reverse osmosis.
•   Mineral water – Naturally contains certain
    amounts of minerals from the source.
•   Sparkling water – Naturally containing carbon
    dioxide
•   Artesian water – Source is a confined aquifer.
•   Municipal water – Tap water.
                                                     58
                   Water Filtration

•   Reverse Osmosis -
    Pressurized water is sent
    through a selective
    membrane filter.
•   Distillation – Water is boiled;
    Steam is collected and
    bottled.
•   Ozonation – Ozone is
    bubbled through water to kill
    microorganisms.
                                      59
                    Gold Mining

•   Of all the metals that are mined, gold may be
    the most polluting.
•   Heap Leaching – A mining process that
    extracts precious metals (such as gold) by
    pouring a cyanide solution over the ore.
      The cyanide dissolves the gold or silver in

       the crushed ore.
      The liquid is collected and the metals are

       extracted from it.
      The cyanide is reused and the ore is

       dumped.                                       60
Heap Leaching




                61
                 Ocean Pollution

•   In spring 2010, a beached whale died off the
    coast of Seattle.
•   Inside the whale’s stomach was found…
      A pair of sweatpants

      A golf ball

      20 plastic bags

      Surgeon’s gloves

      Duct tape

      Plastic pieces

•   Did not play a role in whale’s death           62
                 Ocean Pollution

•   The two biggest ocean pollutants:
      Oil

      Plastics

•   Estimated 6 million metric tons of plastic
    bottles, packaging material, and other litter
    tossed from ships into the ocean annually.
      Plastic bottles gradually break down into

       smaller pieces.
      They never fully decompose because they

       are synthetic and not found in nature.
                                                    63
Ocean Pollution




                  64
                   Ocean Pollution

•   Most of the oil in the ocean comes from
    nonpoint sources.
•   The biggest one is people dumping used
    motor oil from their cars into the sink or storm
    drains.
      Cause more long-term buildup.

•   The biggest point source is oil spills or leaks
    from oil platforms or tankers.
      The point sources are much more

       concentrated and cause much more short-
       term damage.                                  65
                      Oil Spills

•   Exxon Valdez (1989) –
    One of the worst incidents
    of water pollution to ever
    occur.
      High volume of oil

       spilled
      Remote location and a

       poor cleanup response
      Thousands of sea birds,

       sea mammals, and fish
       were killed.                66
         Exxon Valdez and Tanker Design

•   Resulted in the Oil Pollution Act of 1990
     Mandated a double-hull design for oil

      supertankers by 2015.
     Would have reduced the oil spilled by

      Exxon Valdez by 60%




                                                67
                   Deep Water Horizon

•       The Deepwater Horizon was a floating oil rig
        in the Gulf of Mexico contracted to British
        Petroleum.
    •   An explosion
        occurred on
        this rig in
        April of 2010,
        resulting in
        the worst oil
        spill ever.
                                                       68
                Deep Water Horizon

•   The rig was working
    drilling and preparing
    a well deep in the
    seabed of the Gulf of
    Mexico when a
    sudden surge of oil
    and natural gas
    traveled up through
    the rig, causing a
    blowout at the
    surface.
                                     69
                Deepwater Horizon

•   Even as the
    flames were
    contained, the
    oil continued
    to gush out at
    a rate of about
    60,000 barrels
    per day.



                                    70
Deepwater Horizon




                    71
                    Aftermath

•   Damage from the oil spill was the most
    intense in three areas:
      The beaches of the nearby states,

       especially Louisiana, Missisippi, and
       Alabama.
      Underwater; Oil plumes stretched as long

       as 10 miles in some spots.
      The sea floor; Oil and residue 2-5 inches

       thick has been recorded in some areas.

                                                   72
                Laws and Lawsuits

•   BP reported actual cleanup costs of $3.12
    billion.
•   The Oil Pollution Act of 1990 also limited the
    BP’s liability for non-cleanup costs to $75
    million unless gross negligence can be
    proven.
•   BP estimates that its total costs of cleanup,
    recovery, litigation, and restitution will be
    about $40 billion.

                                                     73
                 Infectious Agents

•   Main source of waterborne pathogens is
    untreated and improperly treated human
    waste.
      Animal wastes from feedlots and fields is

       also an important source of pathogens.
•   In developed countries, sewage treatment
    plants and pollution-control devices have
    greatly reduced pathogens.
      Coliform bacteria - Intestinal bacteria.

        - Escherichia coli (E. coli)
                                                   74
           Oxygen-Demanding Wastes

•   Water with an oxygen content > 6 ppm will
    support desirable aquatic life.
      Water with < 2 ppm oxygen will support

       mainly detritivores and decomposers.
•   Oxygen is added to water by diffusion from
    wind and waves, and by photosynthesis from
    green plants, algae, and cyanobacteria.
      Oxygen is removed from water by

       respiration and oxygen-consuming
       processes.
                                                 75
       Oxygen-Demanding Wastes Cont’d
•   Biochemical Oxygen Demand - Amount of
    dissolved oxygen consumed by aquatic
    microorganisms.
      Dissolved Oxygen Content - Measure of
       dissolved oxygen in the water.
•   Effects of oxygen-demanding wastes on
    rivers depend on volume, flow, and
    temperature of river water.
      Oxygen Sag - Oxygen levels decline
       downstream from a pollution source as
       decomposers metabolize waste materials.
                                                 76
Oxygen Sag




             77
    Plant Nutrients and Cultural Eutrophication

•   Oligotrophic - Bodies of water that have clear
    water and low biological productivity.
•   Eutrophic - Bodies of water that are rich in
    organisms and organic material.
      Eutrophication - Process of increasing

       nutrient levels and biological productivity.
        - Cultural Eutrophication - Increase in

          biological productivity and ecosystem
          succession caused by human activities.

                                                      78
79
80
             WATER LEGISLATION

•   Clean Water Act
     Enacted in 1972, amended in 1977 and

      1987.
     Covers only “relatively permanent” waters,

      including streams, oceans, rivers, and
      lakes.
     Point-source pollutants cannot be

      discharged into waters without permits
      from their state.
     Does not address non-point pollutants.
                                                   81
             POLLUTION CONTROL

•   Source Reduction
     Cheapest and most effective way to deal

      with pollution is avoid producing it or
      releasing it into the environment.




                                                82

				
DOCUMENT INFO
Description: Powerpoint presentation given as a lecture to environmental science students studying a unit on water, the water cycle, and water pollution.