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Water Pollution Chapter 19

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Title: Water Pollution Chapter 19


1
Water Pollution - Chapter 19
2
Water Pollution - Types
  • Water Pollution any chemical, biological, or
    physical change in water quality that has a
    harmful effect on living organisms or makes water
    unsuitable for desired uses.
  • Infectious Agents bacteria, viruses, protozoa
  • Oxygen Damaging Wastes animal manure and plant
    debris
  • Inorganic Chemicals water soluble acids, salts
  • Organic Chemicals oil, gasoline, plastics,
    pesticides, cleaning solvents, detergents
  • Plant Nutrients nitrates, phosphates, and
    ammonium
  • Sediment soil, silt
  • Radioactive Materials iodine, radon, uranium,
    cesium, and thorium
  • Heat excessive heat

3
Water Pollution - Diseases
  • Water Borne Diseases
  • Typhoid Fever
  • Cholera
  • Bacterial Dysentery
  • Enteritis
  • Infectious hepatitis
  • Ameobic dysentery
  • Giardiasis
  • Schistosomiasis

4
Measuring Water Quality
  • Use a variety of methods
  • Measuring the amounts of coliform bacteria
    present
  • Determining water pollution from oxygen demanding
    wastes and plant nutrients by measuring the
    biological oxygen demand (BOD).
  • Using chemical analysis to determine the presence
    of inorganic and organic chemicals that pollute
    water
  • Using living organisms as indicator species

5
Point Sources
  • Point Sources discharge pollutants at specific
    locations through pipes, ditches, or sewers, into
    bodies of surface water easy to identify,
    monitor, and regulate
  • Factories
  • Sewage treatment plants
  • Active and abandoned underground mines
  • Oil tankers

6
Nonpoint Sources
  • Nonpoint Sources cannot be traced to any single
    site of discharge
  • Large land areas that pollute through runoff,
    subsurface flow, or deposition from the
    atmosphere
  • Acid deposition
  • Runoff of chemicals into surface water from
    croplands, livestock feedlots, logged forests,
    urban streets, lawns, golf courses, and parking
    lots
  • Agriculture nonpoint sources
  • Sediments
  • Inorganic fertilizers
  • Manure
  • Salts dissolved in irrigation water
  • Pesticides
  • Responsible for 64 of the total mass of
    pollutants entering streams
  • Responsible for 57 of the pollutants entering
    lakes

7
Climate Change and Water Pollution
  • Some areas will get more precipitation and others
    will get less
  • More intense downpour will flush more harmful
    chemicals, plant nutrients, and microorganisms
    into the waterways.
  • Massive flooding
  • Can carry many disease carrying pathogens
  • Prolonged drought
  • Can reduce river flows that dilute waste
  • Increase salinity levels
  • Cause infectious diseases to spread more rapidly
    because people lack water to stay clean
  • Warmer water temperatures can threaten aquatic
    life by reducing dissolved oxygen levels and
    increase the growth rate of populations of
    harmful bacteria

8
Pollution of Streams
  • Rivers have a combination of dilution and
    bacterial decay methods. This works as long as
    pollutants do not overload the streams and
    drought, damming, or diversion do not reduce the
    flow of water.
  • Rivers do not eliminate slowly degradable and
    nondegradable pollutants
  • Oxygen Sag Curve the curve indicating a
    depletion of dissolved oxygen due to the bacteria
    breaking down the waste and depleting the
    dissolved oxygen
  • Biological Oxygen Demand amount of O2 required
  • The time needed to recover from waste depends on
  • Volume of incoming degradable wastes
  • Streams volume
  • Streams flow rate
  • Streams temperature
  • Streams pH level

9
Threats to Ecological Services of Streams
  • Major threats to ecological services are
  • Pollution
  • Disruption of water flows and species composition
    by dams
  • Channelization
  • Diversion of water from rivers for irrigation and
    urban areas
  • Overfishing
  • Ways to improve water quality
  • Require that cities withdraw their drinking water
    downstream rather than upstream this would mean
    that each city would have to clean up its own
    waste outputs rather than passing them downstream
    --- upstream users who have clean water without
    high cleanup costs oppose this approach.

10
Good News About Stream Pollution
  • Water pollution control laws have increased the
    number and quality of wastewater treatment plants
    and reduced industry pollution
  • Laws have been enacted to prevent the dishcharge
    of industrial wastes into the river and sewage
    systems and to appropriate funds to updgrade
    sewage treatment facilities
  • River discharges have decreased increased
    dissolved oxygen levels
  • Clean up of the Ohio Cuyahoga River, Thames
    river, Rhine River

11
Bad News About Stream Pollution
  • Large fish kills
  • Drinking water contamination
  • There are accidental and deliberate releases of
    toxic inorganic chemicals by rivers and mines
  • Malfunctioning sewage treatment plants
  • Nonpoint runoff or pesticides and nutrients
  • Sewage and industrial wastes is a large problem
    in developing countries

12
Pollution Problems of Lakes
  • Dilution is less effective
  • Little mixing due to layers
  • Little flow
  • Ponds contain small amounts of water
  • More vulnerable to contamination by plant
    nutrients, oil, pesticides, and toxic chemicals
    such as lead, mercury, and selenium
  • Toxic chemicals and acids can enter lakes and
    reservoirs from the atmosphere
  • As they pass through food webs, they can be
    biologically magnified

13
Eutrophication
  • Eutrophication the natural nutrient enrichment
    of lakes caused by the inputs of nutrients and
    silt erosion
  • Cultural Eutrophication when urban or
    agricultural runoff caused by human activities
    causes an increase in plant nutrients mostly
    nitrate and phosphate containing effluents
  • Nutrient overload can cause
  • Dense growth of organisms such as algae,
    cyanobacteria, water hyacinths, and duckweed
  • When algae die, decomposition by aerobic bacteria
    depletes dissolved oxygen ? can kill fish and
    other aerobic aquatic animals
  • Anaerobic bacteria can take over and produce
    gaseous decomposition which creates a smelly,
    highly toxic hydrogen sulfide and methane
  • 1/3 of the medium lakes and 85 of large lakes
    near major population centers have cultural
    eutrophication

14
Preventing Eutrophication
  • Prevention Methods
  • Advanced waste water treatment to remove nitrates
    and phosphates
  • Bans or limits on phosphates in household
    detergents other cleaning agents
  • Soil conservation and land-use control to reduce
    nutrient runoff
  • Cleanup Methods
  • Removing excess weeds
  • Controlling undesirable plant growth with
    herbicides and algacides
  • Pumping air through tanks and reservoirs to avoid
    oxygen depletion

15
Pollution in the Great Lakes
  • Contain at least 95 of the fresh surface water
    in the US and 20 of the worlds fresh surface
    water
  • Home for about 38 million people --- 30 of
    Canadas population and 14 of the US population
  • Receives input from 7 states and much of Ontario
    in Canada
  • Less than 1 of the water flows out each year
  • Receive large quantities of land runoff with
    acids, pesticides, and other toxic chemicals by
    deposition from the atmosphere
  • In 1972 a 20 billion dollar control program
    was carried out.
  • What needs to happen
  • Ban on the use of chlorine as a bleach in pulp
    and the paper industry
  • Ban on all new incinerators in the area
  • Ban on discharge into the lakes of 70 toxic
    chemicals

16
Why is Groundwater Important?
  • Groundwater supplies
  • 75 of drinking water in Europe
  • 51 in the US
  • 32 in Asia
  • 29 in Latin America

17
Groundwater Pollution
  • Groundwater pollution comes from
  • Storage lagoons
  • Septic tanks
  • Landfills
  • Hazardous waste dumps
  • Deep injection wells
  • Stored gasoline, oil, solvents, and hazardous
    wastes underground can corrode and leak
  • Pollutants in drinking water high risk health
    problems
  • Contamination with petrochemicals (gasoline and
    oil)
  • Organic solvents (TCE)
  • Pesticides
  • Arsenic
  • Lead
  • Fluoride
  • Groundwater cannot clean itself of degradable
    wastes as flowing surface water can because it
    flows so slowly, has much smaller amounts of
    decomposing bacteria, and has cold temperatures
    that slow down the chemical reactions that
    decompose waste

18
What is the Extent of Groundwater Pollution?
  • We do not know few countries locate, track, and
    test aquifers
  • We know more specifics about the contamination in
    the US.

19
How Can We Protect Groundwater?
  • Aquifers are almost impossible to clean because
    of their enormous volume, inaccessibility, and
    slow movement it is also expensive
  • Preventing contamination!
  • Monitor aquifers near landills and underground
    tanks
  • Require leak detection systems for underground
    tanks used to store hazardous liquids
  • Banning or more strictly regulated disposal of
    hazardous wastes in deep injection wells and
    landfills
  • Storing hazardous liquids above ground in tanks
    with systems that detect and collect leaking
    liquids

20
How Much Pollution Can the Oceans Tolerate?
  • Oceans can dilute, disperse, and degrade large
    amounts of raw sewage, sewage sludge, oil, and
    some types of degradable industrial waste,
    especially in deep-water areas
  • Some organisms have been resilient to the
    industrial waste, but is it moral to drop there?
  • We know less about the deep ocean than about
    outer space
  • Dumping would delay prevention
  • Would promote further degradation of the earths
    life supporting system

21
How Do Pollutants Affect Coastal Areas?
  • Coastal areas wetlands, estuaries, coastal
    reefs, and mangrove swamps bear the brunt of
    our inputs of waste into the ocean
  • 40 of the worlds population lives on the coast
  • 14 of 15 of the worlds largest metro areas are
    near coastal waters
  • Coastal populations are growing more rapidly than
    the global population
  • Municipal sewage and industrial waste are
    sometimes dumped without treatment
  • Causes widespread beach pollution and shellfish
    contamination
  • Pollution on European Beaches has dropped
  • Recent studies have found human viruses in raw
    sewage, effluent from treatment plants, and
    leaking septic tanks
  • ¼ of the people using coastal beaches in the US
    develop ear infections, sore throats and eyes,
    respiratory disease, and GI disease
  • Runoff and acid deposition can increase nitrates
    and phosphates which cause harmful algal blooms
    (HABs) red, brown, or green tides depending on
    their color
  • Can cause waterborne and airborne toxins that
    damage fisheries
  • Kills some fish-eating birds
  • Reduce tourism
  • Poison seafood
  • Creates oxygen-depleted zones dead zones
    because of excessive nonpoint inputs of
    fertilizers and animal wastes from land runoff
    and deposition of nitrogen compounds from the
    atmosphere
  • Aquatic life dies or moves elsewhere

22
Chesapeake Bay
  • Largest estuary in the US
  • Population continues to grow
  • Removes waste from point and nonpoint sources
  • Large pollution sink because it is shallow and
    only 1 is flushed into the Atlantic Ocean
  • 1983 Chesapeake Bay Program integrated
    coastal management
  • Phosphorus and nitrogen levels have declined
  • Population still continues to increase
  • Difficulty with funding

23
What Pollutants Do We Dump Into the Ocean?
  • Barges and ships dump large quanitities of dredge
    spoils material laden with toxic metals scraped
    from the bottoms of harbors and rivers
  • Sewage sludge also dumped into oceans --- since
    1992 this has been banned in the US
  • Difficult to enforce
  • Kills 100,000 marine mammals
  • Many countries continue to drop toxic wastes into
    the ocean

24
Effects of Oil on Ecosystems?
  • Crude and refined petroleum are accidentally or
    deliberately released into the ocean
  • Tanker accidents and blowouts at offshore
    drilling rigs
  • Offshore wells, washing tankers releasing the
    oily water, pipeline and storage tank leak
  • Most oil pollution comes from activities on land
    - waste oil dumped, spilled, or leaked onto the
    land by people
  • Effects depend on the type of oil, amount
    released, distance released from shore, time of
    year, weather conditions, average water
    temperature, and ocean currents
  • Effects
  • Can kill animals right away
  • Coat the feathers and fur causes the loss of
    buoyancy and many of them drown or die from loss
    of body heat
  • Can smoother bottom-dwelling organisms
  • Make aquatic organisms unfit for human
    consumption
  • Most can recover within 3 years from crude oil,
    10 years from refined oil

25
Cleaning Oil Spills
  • Mechanical methods floating booms to contain
    the oil spill or keep it from reaching certain
    areas, skimmer boats to vacuum up some of the oil
    into collection barges, absorbent pans to soak up
    the oil
  • Chemical methods using coagulating agents to
    cause floating oil to clump together for easy
    pickup, using dispersing agents to break up oil
    slicks
  • Fire can burn off floating oil, but crude oil
    is hard to ignite
  • Natural action wind and waves mixes the oil
    with water and bacteria biodegrade some of the
    oil
  • Only 12 15 can be recovered from an oil spill

26
Protecting Coastal Waters
  • Reduce the flow of pollution from land and from
    streams emptying into the ocean
  • Integrate prevention of air pollution

27
Water Pollution From Nonpoint Sources
  • Reduce fertilizer runoff use slow release
    fertilizer and use none on steep land
  • Reduce the need for fertilizer by alternating
    plantings between row crops and nitrogen fixing
    plants
  • Plant buffer zones of vegetation between
    cultivated fields and surface water
  • Reduce pesticide runoff only use pesticide when
    needed and use biological control
  • Control runoff and infiltration of manure from
    animal feedlots
  • Preserve wetland
  • Reduce soil erosion and flooding by reforesting
    wetlands

28
Water Pollution From Point Sources - Legal
Approach
  • Most developing countries drop 80 90 of their
    untreated sewage into rivers, streams, and lakes
    which are used for drinking water, bathing, and
    washing clothes
  • Developed countries purify their waste to some
    degree
  • Clean Water Act 1977
  • Water Quality Act 1987
  • Discharge trading policy to use market forces
    to reduce water pollution cap and trade system

29
Strengthen the US Clean Water Act
  • Increase funding for nonpoint sources of
    pollution
  • Increase monitoring of state programs
  • Strengthen programs to prevent and control toxic
    waste pollution
  • Prove more funding and authority for integrated
    watershed and airshed planning
  • Require states to do a better job monitoring and
    enforcing water pollution laws
  • Expand the rights of citizens to bring lawsuits
    to ensure that water pollution laws are enforced
  • Halting the loss of wetlands
  • Higher standards for restoring wetlands
  • Creating new wetlands before filling any natural
    wetlands

30
Water in the US
  • Water improvements in the US
  • Rivers and lakes are more fishable and swimmable
  • The amount of topsoil lost has decreased
  • More people are served by sewage treatment plants
  • Bad News
  • Many lakes and rivers are still unsafe for
    fishing, swimming, and other recreational uses
  • Hog, poultry, and cattle farm runoff pollutes
    rivers
  • Large quantities of illegally dumped waste is put
    into US rivers each year
  • Many fish caught are unsae to each
  • Less than 2 of the nations streams are healthy
  • 40 of the countries surface water and
    groundwater is unsafe for human consumption
  • Decrease in wetlands

31
The Technological Approach for Dealing with
Pollution
  • In rural and suburban areas, sewage from each
    house is discharged into a septic tank.
  • 25 of all homes in the US are served by septic
    tanks
  • Septic tanks should be cleaned out every 3-5
    years to prevent groundwater pollution
  • In urban areas, waterborne wastes run though a
    series of sewer pipes
  • Some have separate lines for runoff or storm
    water but combined is cheaper
  • When rainwater overflows the combined system, the
    discharged untreated sewage goes directly into
    the surface waters

32
Levels of Purification
  • Primary Sewage Treatment a mechanical process
    that screens out debris and allows suspended
    solids to settle out as sludge in a settling
    tank.
  • Secondary Sewage Treatment a biological process
    where aerobic bacteria remove up to 90 of the
    biodegradable, oxygen-demanding organic wastes
  • Some use trickling filters aerobic bacteria
    degrade sewage as it seeps through a bed of
    crushed stones covered with bacteria and protozoa
  • Some use activated sludge process pumping
    sewage into a large tank and mixing it or several
    hours with bacteria-rich sludge and air bubble to
    spur degradation of microorganisms
  • Then, water goes to a sedimentation tank where
    the suspended solids and microorganisms settle
    out as sludge
  • Sludge is broken down in an anaerobic digester
    and 1) incinerated 2) dumped into an ocean or
    landfill or 3) applied to land as fertilizer
  • Advanced sewage treatment a series of
    specialized chemical and physical processes that
    remove specific pollutants left in the water
    after primary and secondary treatment
  • Rarely used because they cost twice as much to
    build and four times as much to operate

33
Solutions for Sewage Sludge
  • In the US, 9 by weight is converted to compost
    for use as a soil conditioner
  • 36 is applied to farmland, forests, golf
    courses, cemeteries, parkland, highway medians,
    and degraded land as fertilizer
  • 55 is dumped in conventional landfills or
    incinerated
  • can contaminate groundwater or pollute the air
    with toxic chemicals and produces a toxic ash
    buried in landfills
  • Using sludge to fertilize crops
  • Can cause health problems and lawsuits because of
    harmful bacteria and toxic wastes

34
Is Water Safe to Drink?
  • Access to clean water in developing countries is
    up to 68 in 2000 from 30 in 1970
  • 1/5 of the people in developing countries do not
    have access to clean drinking water
  • People get their water from
  • Shallow groundwater wells that are easily
    contaminated
  • Nearby polluted riverwater
  • Mudholes used by both animals and human
  • Must drink contaminated water or buy expensive
    water from street vendors (most of it is
    polluted)
  • To give access to clean drinking water, it would
    cost 23 billion and prevent
  • 3.4 billion illnesses
  • 3.4 million deaths

35
Purifying Drinking Water
  • Store surface water in a reservoir and allow
    suspended matter to settle
  • Sent to a purification plant and treated
  • Water is run through sand filters and activated
    charcoal
  • Can use UV light
  • Strips of cloth to filter out cholera-producing
    bacteria

36
Protecting Drinking Water
  • 54 countries in North America and Europe have
    safe drinking water standards
  • U.S. Safe Drinking Water Act of 1974 requires the
    EPA to establish national drinking water
    standards called maximum contaminant levels for
    any pollutant that may have adverse effects on
    human health
  • Private wells are not required to meet standards
    because of the cost of testing each well and home
    owners opposition to testing
  • 7 million illnesses and 1,200 deaths per year
    from drinking contaminated water

37
Strengthen or Weaken the US Safe Drinking Water
Act
  • Strengthened
  • Combine at least ½ of the 50,000 water systems
    that serve fewer than 3,300 people with larger
    ones nearby
  • Strength and enforce public notification
    requirements about violations of drinking water
  • Ban all lead in new plumping pipes, faucets, and
    fixtures
  • Weaken
  • Elimate national tests of drinking water
  • Suspened the requirement that the media be
    advised of water emergencies
  • Allow states to give drinking water systems a
    right to violate a certain standards if it cannot
    comply
  • Eliminate the requirement that water systems use
    affordable, feasible technology to remove
    cancer-causing contaminants

38
Is Bottled Water the Answer
  • Bacteria contaminate ½ of bottled water purchased
    in the US
  • Does the water bottling company belong to the
    IBWA International Bottled Water Association
    require testing
  • National Sanitation Foundation tests for 200
    chemical and biological contaminants
  • Bottled water causes excess trash, toxic gases
    and liquids to be released during the manufacture
    of water bottoms, emission of greenhouse gases
    during the shipping and delivery of bottled water

39
Making a Difference - Individuals Matter!
  • Reduce and prevent water pollution
  • Reduce poverty
  • Greater emphasis on keeping groundwater from
    contamination
  • Putting more emphasis on preventing nonpoint
    pollution
  • Reducing the toxicity or volume of pollutants
  • Reusing wastewater instead of discharging it
  • Recycling pollutants
  • Working with nature to treat sewage
  • Integrating government policies for water
    pollution with policies for air pollution,
    agriculture, energy, solid and hazardous wastes,
    climate change, land use, and population
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