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Water Pollution


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Title: Water Pollution

Water Pollution
  • Chapter 22

John Todds Living Machine
  • Sewage flows into passive solar greenhouse or
    outdoor sites containing rows of large open tanks
  • 1st tanks- algae microorganisms decompose
    organic wastes
  • Water hyacinths, cattails, bulrushes, other
    aquatic plants use remaining nutrients

  • Water runs through artificial marsh (sand,
    gravel, bulrush plants) that filters out algae
    remaining organic wastes
  • Aquarium tasks- snails zooplankton consume
    microorganisms in turn are consumed by
    crayfish, tilapia, other fish can be eaten or
    sold as bait

  • 10 days later- 2nd artificial marsh
  • Purified for drinking by exposing to UV light or
    passing through ozone generator

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

Table 22-1Page 492
Table 22-1 Major Categories of Water Pollutants
INFECTIOUS AGENTS Examples Bacteria, viruses,
protozoa, and parasitic worms Major Human
Sources Human and animal wastes Harmful
Effects Disease
Table 22-1Page 492
Table 22-1 Major Categories of Water Pollutants
OXYGEN-DEMANDING WASTES Examples Organic waste
such as animal manure and plant debris that can
be decomposed by aerobic (oxygen-requiring)
bacteria Major Human Sources Sewage, animal
feedlots, paper mills, and food processing
facilities Harmful Effects Large populations of
bacteria decomposing these wastes can degrade
water quality by depleting water of dissolved
oxygen. This causes fish and other forms of
oxygen-consuming aquatic life to die.
Table 22-1Page 492
Table 22-1 Major Categories of Water Pollutants
INORGANIC CHEMICALS Examples Water-soluble 1)
acids, (2) compounds of toxic metals such as lead
(Pb), arsenic (As), and selenium Se), and (3)
salts such as sodium chloride (NaCl) in ocean
water and fluorides (F) found in some
soils Major Human Sources Surface runoff,
industrial effluents, and household
cleansers Harmful Effects Can (1) make fresh
water unusable for drinking or irrigation, (2)
cause skin cancers and crippling spinal and neck
damage (F), (3) damage the nervous system,
liver, and kidneys (Pb and As), (4) harm fish and
other aquatic life, (5) lower crop yields, and
(6) accelerate corrosion of metals exposed to
such water.
Table 22-1Page 492
Table 22-1 Major Categories of Water Pollutants
ORGANIC CHEMICALS Examples Oil, gasoline,
plastics, pesticides, cleaning solvents,
detergents Major Human Sources Industrial
effluents, household cleansers, surface runoff
from farms and yards Harmful Effects Can (1)
threaten human health by causing nervous system
damage (some pesticides), reproductive disorders
(some solvents), and some cancers (gasoline, oil,
and some solvents) and (2) harm fish and
Table 22-1Page 492
Table 22-1 Major Categories of Water Pollutants
PLANT NUTRIENTS Examples Water-soluble
compounds containing nitrate (NO3 ), phosphate
(PO43), and ammonium (NH4) ions Major Human
Sources Sewage, manure, and runoff of
agricultural and urban fertilizers Harmful
Effects Can cause excessive growth of algae and
other aquatic plants, which die, decay, deplete
water of dissolved oxygen, and kill fish.
Drinking water with excessive levels of nitrates
lowers the oxygen-carrying capacity of the blood
and can kill unborn children and infants
(bluebaby syndrome).
Table 22-1Page 492
Table 22-1 Major Categories of Water Pollutants
SEDIMENT Examples Soil, silt Major Human
Sources Land erosion Harmful Effects Can (1)
cloud water and reduce photosynthesis, (2)
disrupt aquatic food webs, (3) carry pesticides,
bacteria, and other harmful substances, (4)
settle out and destroy feeding and spawning
grounds of fish, and (5) clog and fill lakes,
artificial reservoirs, stream channels, and
Table 22-1Page 492
Table 22-1 Major Categories of Water Pollutants
isotopes of iodine, radon, uranium, cesium, and
thorium Major Human Sources Nuclear and
coal-burning power plants, mining and processing
of uranium and other ores, nuclear weapons
production, natural sources Harmful Effects
Genetic mutations, miscarriages, birth defects,
and certain cancers
Table 22-1Page 492
Table 22-1 Major Categories of Water Pollutants
heat Major Human Sources Water cooling of
electric power plants and some types of
industrial plants. Almost half of all water
withdrawn in the United States each year is for
cooling electric power plants. Harmful Effects
Lowers dissolved oxygen levels and makes aquatic
organisms more vulnerable to disease, parasites,
and toxic chemicals. When a power plant first
opens or shuts down for repair, fish and other
organisms adapted to a particular temperature
range can be killed by the abrupt change in water
temperatureknown as thermal shock.
Coliform Bacteria Count
  • Presence indicates that water has been exposed to
    human or animal waste (contains disease causing

Dissolved Oxygen
  • Related to the amount of oxygen-demanding wastes
    (broken down by oxygen-requiring bacteria plant

Biological Indicators
  • Analyze aquatic plants (cattails) or
    bottom-dwellers (mussels) or filter feeders

Point Source Pollution
  • Discharge of pollutants at specific locations
    through drain pipes, ditches, or sewer lines into
    surface water
  • Factories
  • Underground mines
  • Sewage treatment plants
  • Oil tankers

  • Easy to identify, monitor, regulate due to
    specific location

Nonpoint Source Pollution
  • Large or dispersed land areas that discharge
    pollutants into environment over a large area
  • Acid deposition
  • Runoff from croplands, feedlots for livestock,
    logged forests, urban streets, lawns, golf
    courses, parking lots

Safe Drinking Water
  • 74-95 of people have access to clean drinking
  • - 1.4 billion people do NOT
  • - 9,300 die daily due to infectious diseases
    spread by contaminated water or lack of water for
    adequate hygiene

Developing Countries
  • 26 of people do not have access to clean
    drinking water

Decreased Quality of Surface Water
  • Intense downpours more chemicals, plant
    nutrients, microorganisms
  • Massive flooding spread of disease carrying
    pathogens into water treatment facilities wells
  • Overflow of lagoons sewer lines raw sewage
    into rivers streams

  • Drought reduced river water to dilute waste
  • Spread of disease due to lack of water to keep
  • Warm temperatures lower dissolved oxygen levels
    higher growth rates of bateria

Pollution of Streams
  • Overloaded with pollutants
  • Drought
  • Damming or water diversion
  • Oxygen sag curve depletion of DO by bacteria
    reduced populations of organisms with high oxygen

Normal clean water organisms (trout, perch,
bass, mayfly, stonefly)
Trash fish (carp, gar, leeches)
Fish absent, fungi, sludge worms, bacteria (anaero
Trash fish (carp, gar, leeches)
Normal clean water organisms (trout, perch,
bass, mayfly, stonefly)
8 ppm
Types of organisms
8 ppm
Dissolved oxygen (ppm)
Biological oxygen demand
Clean Zone
Recovery Zone
Septic Zone
Decomposition Zone
Clean Zone
Figure 22-5Page 496
Limiting Factors
  • Volume of degradable waste
  • Stream volume
  • Flow rate
  • Temperature
  • pH level

Controlling Stream Pollution in Developed
  • Increased number quality of water-water
    treatment plants
  • Industries are required to reduce or eliminate
    point-source pollution
  • - Accidental or deliberate release of toxic,
    inorganic, organic chemicals causes fish kills
    contaminates drinking water

  • - Sewage treatment plants malfunction
  • - Nonpoint runoff of pesticides excess plant
    nutrients from cropland animal feedlots

Controlling Stream Pollution in Developing
  • - Discharge of untreated sewage industrial
  • - Only 10 of Chinese city sewage is treated

Ganges River
  • Cremated bodies are returned to river (to
    increase chances for heaven)
  • Bodies are burned in open air wood fires
  • Some bodies are dumped into river only partially
    burned (decreases DO adds bacteria viruses)
  • Government adding sewage treatment plants
    electric crematoriums

Diluting Lake Pollution
  • Less effective
  • Stratified layers with little vertical mixing
  • Little flow water is replaced every 1-100 years
    (unlike days to weeks for streams)

  • Physical, chemical, biological changes that
    take place after receiving inputs of plant
    nutrients (nitrates phosphates) from natural
    erosion runoff

Cultural Eutrophication
  • Over nourishment of aquatic ecosystems with plant
    nutrients due to human activities (agriculture,
    urbanization, discharge from industrial plants
    sewage treatment plants

Eutrophication Prevention
  • Use advances ( expensive) waste treatment
    systems to remove nitrates phosphates from
    waste water
  • Ban (or limit) use of phosphate in household
    detergents other cleaning agents
  • Soil conservation land-use control to reduce
    nutrient runoff

Eutrophication Cleanup
  • Mechanically remove excess weeds
  • Control plant growth with herbicides algaecides
  • Pump air through lakes reservoirs to avoid
    oxygen depletion

Lake Washington
  • Water was diverted into Puget Sound
  • Puget sound has rapid exchange rate with Pacific
  • Lake was NOT filled with weeds sediment
  • Preventative action

The Great Lakes
  • Decreased algal blooms
  • Increased DO levels
  • Increased commercial fishing catches
  • New or upgraded sewage treatment plants
  • Better treatment of industrial wastes
  • Ban of phosphate containing cleansers

  • - August- low DO levels kills fish
  • - ¾ of shoreline is NOT clean enough for swimming
  • - Nonpoint pollution is still high
  • - Highly polluted sediments in hot spots
  • - 80 drop in EPA funded cleanup

Groundwater Contamination
  • Leaking from industrial waste ponds (no liners)
  • Leaking of underground tanks (gasoline, diesel
    fuel, home heating oil, toxic solvents)
  • Leaching of nitrate fertilizers
  • Soils rock may contain arsenic
  • High levels of naturally occurring fluoride

Serious Problems because
  • Removal can be difficult costly
  • Slow water movement
  • Pollutants can get easily into drinking water
    irrigation water

As a Result
  • High fluoride levels crippling spine neck
    damage variety of dental problems
  • High nitrate levels cancers blue baby
    syndrome (blood lacks the ability to carry
    sufficient oxygen)
  • High arsenic level cancer (skin, bladder, lung)

Figure 22-10Page 503
Groundwater Pollution
Find substitutes for toxic chemicals
Pump to surface, clean, and return to aquifer
(very expensive)
Keep toxic chemicals out of the environment
Install monitoring wells near landfills and
underground tanks
Inject microorganisms to clean up contamination
(less expensive but still costly)
Require leak detectors on underground tanks
Ban hazardous waste disposal in landfills and
injection wells
Pump nanoparticles of inorganic compounds to
remove pollutants (may be the cheapest, easiest,
and most effective method but is still being
Store harmful liquids in aboveground tanks with
leak detection and collection systems
Ocean Pollution
  • Coastal areas- dumping of sewage industrial
    waste, agricultural waste, algal blooms,
    oxygen-depleted zones (excessive fertilizers
    animal wastes)
  • 40 of world population lives with 100km (62mi)
    of coast

Ocean Pollution from Rivers
  • Plant nutrients from river systems causes algal
    blooms (red, brown, green) releases waterborne
    airborne toxins that damage fisheries, kills
    fish-eating birds, reduces tourism, poisons

Chesapeake Bay
  • Waste from point nonpoint sources
  • Shallow bay
  • Sewage treatment industrial plants
  • Runoff from urban, suburban, agricultural land
  • Deposition from atmosphere

  • Integrated Coastal Management
  • Land-using regulations for agricultural urban
  • Ban phosphate detergents
  • Upgrade sewage treatment plants
  • Better monitoring of industrial discharge

Types of Ocean Pollution
  • Dredge spoils- materials (toxic metals) scraped
    from bottoms of harbors rivers to clear
    shipping channels
  • Sewage sludge- gooey mixture of toxic chemicals,
    infectious agents, settled solids removed from
    wastewater at sewage treatment plant

Ocean Oil Pollution
  • Waste oil dumped on ground, poured down drain,
    spilled, or leaked onto land or into sewers by
    cities, industries, people changing motor oil

Oil Ocean Ecosystem
  • Kills aquatic organisms (especially larval forms)
  • Coats bird feather marine mammal fur (destroys
    natural insulation buoyancy)
  • Smothers bottom-dwellers
  • Kills coral reef
  • Economic impact on coastal residents

Mechanical Cleanup
  • Floating booms contain oil spills from reaching
    sensitive areas
  • Skimmer boats vacuum up oil into collections
  • Absorbent devices large mesh pillow filled with
    feathers or hair to soak up oil on beaches

Chemical Methods
  • Coagulating agents cause floating oil to clump
  • Dispersing agents break up oil slicks
  • Fire can burn off floating oil, but crude oil
    is hard to ignite produces air pollution

Cleanup Limitations
  • Can only recover 15 of oil

Reduced Tanker Oil Spills
  • Double hulls (by 2015)
  • Trust fund for cleanups
  • Banning of single hull tankersh

Coastal Water Pollution
Figure 22-14Page 508
Reduce input of toxic pollutants
Improve oil-spill cleanup capabilities
Separate sewage and storm lines
Ban dumping of wastes and sewage by maritime and
cruise ships in coastal waters
Sprinkle nanoparticles over an oil or sewage
spill to dissolve the oil or sewage without
creating harmful byproducts (still under
Ban ocean dumping of sludge and hazardous dredged
Protect sensitive areas from development, oil
drilling, and oil shipping
Require at least secondary treatment of coastal
Regulate coastal development
Use wetlands, solar-aquatic, or other methods to
treat sewage
Recycle used oil
Require double hulls for oil tankers
Reducing Nonpoint Source Pollution
  • Prevent soil erosion by keeping cropland covered
    with vegetation
  • Use slow-release fertilizer
  • Apply pesticides only when needed
  • Use buffer zone around animal feedlots, animal
    waste sites, cultivated fields
  • Use biological controls

Clean Water Act
  • Standards for allowed levels of key water
    pollutants required polluters to get permits
    for discharge

Water Quality Act
  • Control pollution of surface water

EPA Discharge Trading Policy
  • Uses market forces to reduce water pollution

Septic Tanks
  • Underground tank for treating wastewater from a
    home in rural suburban areas
  • Bacteria decomposes organic waste
  • Sludge settles to bottom
  • Effluent flows out of tank into ground

Primary Sewage Treatment
  • Mechanical sewage treatment where large solids
    are filtered out by screens suspended solids
    settle out as sludge in sedimentation tank

Secondary Sewage Treatment
  • 2nd step- aerobic bacteria decomposes 90 of
    degradable, oxygen-demanding organic wastes
  • Sewage bacteria is brought together in
    trickling filters or in activated sludge process

Septic tank with manhole (for cleanout)
Household wastewater
Nonperforated pipe
Distribution box (optional)
Figure 22-15Page 510
Gravel or crushed stone
Drain field
Vent pipe
Perforated pipe
Figure 22-16 Page 511
Grit chamber
Chlorine disinfection tank
Bar screen
Settling tank
Aeration tank
Settling tank
To river, lake, or ocean
Raw sewage from sewers
(kills bacteria)
Activated sludge
Air pump
Sludge digester
Sludge drying bed
Disposed of in landfill or ocean or applied to
cropland, pasture, or rangeland
  • Slimy mixture of bacteria-laden solids toxic
    chemicals metals from industrial household
  • Used to make compost for soil conditioning
  • Biosolids- used to fertilize farmlands, forests,
    golf courses, cemeteries, parkland, highway
    medians, degraded land

Sludge as Fertilizer
  • Must remove harmful bacteria, other pathogens,
    toxic chemicals
  • Removal is expensive rarely done

Toxic / Hazardous Waste
  • Preventing it from reaching sewage treatment
  • Require industries businesses to remove toxic
    hazardous wastes from waste water
  • Switch to waterless composting toilet systems

  • Sewage goes into sedimentation tanks (solids
    settle out as sludge)
  • Liquid is pumped into oxidation ponds where
    bacteria breaks down remaining wastes
  • Water released 1 month later into artificial
    marsh (plants bacteria carry out further
    filtration cleansing)

Wastewater Garden
  • Small, low-tech inexpensive artificial wetland
  • Removes 99.9 of fecal coliform bacteria
  • Removes 80 of nitrates phosphates from
    incoming sewage

Figure 22-18 Page 513
(1) Raw sewage drains by gravity into the
first pool and flows through a long
perforated PVC pipe into a bed of limestone
(3) Wastewater flows through another
perforated pipe into a second pool, where
the same process is repeated.
Treated water
Wetland type plants
Wetland type plants
45 centimeter layer of limestone gravel coated
with decomposing bacteria
First concrete pool
Second concrete pool
(2) Microbes in the limestone gravel break
down the sewage into chemicals that can be
absorbed by the plant roots, and the gravel
absorbs phosphorus.
(4) Treated water flowing from the second
pool is nearly free of bacteria and plant
nutrients. Treated water can be recycled
for irrigation and flushing toilets.
U.S. Reduction of Water Pollution
  • Increased to 94 of community water systems met
    federal health standards
  • Fishable/swimmable areas increased to 60
  • Topsoil loss cut by 1 billion tons
  • Sewage treatment plants increased service to
  • Annual wetland loss decreased to 80

  • - 45 of lakes 40 of streams were too polluted
    for fishing or swimming
  • - Only 19 of streams, 43 of lakes, 36 of
    estuaries have been tested for water quality
  • - 70 of rivers are polluted by animal waste from
    hog, poultry, cattle feedlots meat processing

  • - Fish caught in 25 of lakes are unsafe to eat
    due to pesticides, mercury, or other toxic

Strengthening CWA
  • Increased funding authority to control nonpoint
    sources of pollution
  • Upgrade computer system for monitoring compliance
    with the law
  • Strengthening programs to prevent control toxic
    water pollution
  • More integrated watershed air shed planning to
    protect groundwater surface water from

  • CWA is too restrictive costly
  • Curb on right of landowner to fill in wetlands
  • Landowners want compensation for property value

Water Purification
  • Stored in reservoir for several days (increases
    DO level suspended matter settles)
  • Water is pumped to purification plant for
    filtration chlorination

Vulnerability to Terrorist Attacks
  • Fear of added chemicals or biological agents
  • Hard to protect due to large numbers of
    reservoirs, vast network of purification plants
    distribution systems, accessibility of water
    systems through fire hydrants service

Purification in Developing Countries
  • Exposing water in clear plastic bottle to intense
    sunlight (heat UV will kill infectious microbes
    in 3 hrs)
  • Strips of cloth for filtering cholera-producing
  • Add small amount of chlorine-disinfectant
    solution to plastic or clay storage containers
    with narrow mouth, cap, spigot

Protecting Drinking Water
  • 54 countries have standards for safe drinking
  • Safe Water Drinking Act- requires EPA to
    establish national drinking water standards
    (maximum contaminant levels) for pollutants with
    adverse effects on human health
  • Private wells are exempt

Success of Efforts
  • Most of the 54 countries are in North America
  • CWA laws do not exist or are not enforces in
    developing countries

Strengthening U.S. SDWA
  • Combine water treatment systems that serve fewer
    than 3,300 people
  • Strengthen enforce public notification
    requirements about violations of standards
  • Banning all toxic lead in pipes, faucets,

Weakening SWDA
  • Eliminate national tests of drinking water
    public notification requirements about violations
    of standards
  • Give water systems permanent right to violate
    standards if it cannot afford to comply

  • Eliminate requirement that water systems remove
    cancer-causing contaminants
  • Reduce EPA budget for enforcing CWA

Bottled Water
  • 240-10,000X more expensive than tap water
  • ¼ of bottled water is tap water
  • Bacteria contaminates 1/3
  • Various potentially harmful organic chemicals
    contaminate 1/5
  • 1.5 million tons (bottles) trashed globally

  • Manufacturing plastic water bottles releases
    toxic gases liquids (greenhouse gases)
  • Some tap water is too polluted to drink

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

Figure 22-19Page 516
What Can You Do?
Water Pollution
  • Fertilize your garden and yard plants with manure
    or compost instead of commercial inorganic
  • Minimize your use of pesticides.
  • Never apply fertilizer or pesticides near a body
    of water.
  • Grow or buy organic foods.
  • Compost your food wastes.
  • Do not use water fresheners in toilets.
  • Do not flush unwanted medicines down the toilet.
  • Do not pour pesticides, paints, solvents, oil,
    antifreeze, or other products containing harmful
    chemicals down the drain or onto the ground.

Figure 22-20Page 516
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