WATERChapter 11, Section 3: Water PollutionStandards: SCSh 6d

What is water pollution?

• Introduction of chemical, physical, or biological agents into water that degrade water quality and adversely affect the organisms that depend on the water.

What are two underlying causes of water pollution?

• Industrialization• Rapid human

population growth

How does water pollution differ btwn developed and developing countries?

• Developed countries-• Main causes

• Industry• Agriculture runoff

• Developing countries-• Main causes

• Agriculture runoff• Sewage

What are two sources of pollution?

• Point Source Pollution• Discharged from single source• Easy to trace back to source• Ex: leaking oil tanker, factory

pipe, wastewater treatment plant

• Non-point Source Pollution• Discharged from many different

sources• Difficult to trace back to source• Runoff in river could come from

roads, farms- difficult to pinpoint specific car or farm

• 96% of water pollution is this type

• Educating public about awareness of problem and what not to do helps control non-point

What are 6 types of water pollution?

• Pathogens• Organic matter• Organic chemicals• Inorganic chemicals• Heavy metals• Physical agents

Pathogens• Disease causing

organisms• Ex:

• Bacteria- cholera• Viruses- hepatitis• Protists- Giardia,

Cryptosporidia• Parasitic worms- filariasis

• Sources:• Sewage or animal feces• Livestock feedlots & poultry

farms• Sewage from overburdened

wastewater treatment plants

Organic Matter

• Remains of plants or animals

• Feces• Food waste• Sources:

• Mostly nonpoint sources

• Farms • Food processing plants

Organic Chemicals• Pesticides• Fertilizer• Plastics• Detergents• Gas & oil• Sources:

• Farms • Lawns• Golf courses• Roads• Unlined landfills• Leaky underground storage

tanks

Inorganic Chemicals

• Acids• Bases• Salts• Industrial chemicals• Sources:

• Industrial waste • Road surfaces• Wastewater• Acid rain

Heavy Metals• Lead- causes developmental

problems in children• Mercury- from burning coal;

causes nerve disorders• Cadmium- from batteries;

severe pain, softening of bones, kidney failure

• Arsenic- headache, confusion, diarrhea, drowsiness, skin disorders

• Sources:• Industrial discharge• Unlined landfills • Mining• Some are natural (arsenic) Bangladesh, India- skin disorders

caused by drinking from wells contaminated with natural source of arsenic.

Physical Agents

• Thermal pollution (water too hot)• Sources:

• Removal of trees over river (decreased shade)

• Power plants dump hot waste water

• Runoff from parking lots

• Effects: • hot water decreases

oxygen in water causing massive fish kills

Thermal PollutionThis 1988 thermal image of the Hudson River highlights temperature changes caused by discharge of 2.5 billion gallons of water each day from the Indian Point power plant. The plant sits in the upper right of the photo — hot water in the discharge canal is visible in yellow and red, spreading and cooling across the entire width of the river. Two additional outflows from the Lovett coal-fired power plant are also clearly visible against the natural temperature of the water, in green and blue.

Physical Agents• Sediment pollution

• One of the most common pollutants in Georgia

• Sources:• Construction, soil erosion• Removal of trees/plants

• Effects: • water becomes cloudy

(turbid) which blocks sunlight for plants/algae

• Decreases oxygen in water if plants are affected

• causes lakes/ponds rivers to fill in which increases risk of flooding

How are water pollutants removed from water?

• Wastewater Treatment Plants• Treat waste water pollutants

from homes or industry• Not all chemicals can be

removed from waste water (removing these is expensive & difficult)

• Creates sewage sludge• May be hazardous & must be

disposed of as hazardous waste where it is incinerated & ash buried in secure landfill. (expensive)

• If treated can be turned into fertilizer or added to clay to make bricks.

How does water pollution affect ecosystems?

NATURAL Eutrophication• Dead leaves & animal waste

get decomposed by bacteria.• Bacteria population increases

with increased food source• Bacteria use up oxygen in

water• Hypoxic (lacking oxygen)

water cannot support animals• Animals die and their bodies

accumulate on bottom of pond, filling it in (with dead plant matter)

• Pond becomes meadow and eventually a forest

• Takes 100’s-1,000’s of years

How does water pollution affect ecosystems?

ARTIFICIAL Eutrophication• Acceleration of natural

eutrophication- decades instead of centuries.

• Caused by increased use of fertilizers on crops and sewage runoff

• Algae grow quickly with increased fertilizer.

• Algae outcompete each other and some die.

• Bacteria decompose their bodies and use up oxygen in water.

• Less oxygen puts stress on fish and other aquatic animals.

• Leads to death of ecosystem.

How does water pollution affect ecosystems?

Biomagnification:• When pollutants

accumulate in an animal and that animal is eaten, transferring that pollutant up the food chain.

• Ex: DDT and eagles/osprey.• DDT builds in fat tissue• Highest on food chain most affected b/c pollutant does not breakdown.

What type of pollution can you find in groundwater?

• Anything on surface of ground that can affect surface water can affect groundwater.• Unlined landfills• Industrial wastewater

lagoons• Underground storage tanks

for gasoline, sewage/septic systems, chemicals can leak into groundwater.

• Don’t always know location of these tanks so may leak until someone notices large instance of disease in an area.

Why is cleaning groundwater more difficult than surface water?

• Takes a long time to recharge water to dilute pollutants

• Difficult to reach groundwater to clean it up.

• Pollutant attaches to rocks and soil so even if water pumped out and replaced with clean water would still become polluted.

OCEAN POLLUTION

How are our oceans polluted?• Ships can legally dump

wastewater and non-plastic garbage overboard into some parts of the ocean.

• Most ocean pollution (85%) comes from land• Oil• Toxic waste• Medical waste• Plastic/litter

• Pollutants travel down rivers and most seriously affect coastal areas.

Where does most oil pollution in oceans come from?

• 5% of oil spills from oil tanker accidents• Each year 37 million gallons

of oil from tanker accidents are spilled into oceans

• Most oil ocean pollution comes from cities, towns- non-point sources • People pour car oil down

storm drains (bad- take it to a recycling facility!)

• Small leaks on recreation crafts- boats, jet skis, etc.

Exxon Valdez Oil Spill• March 1989• Exxon Valdez Oil Tanker ran

aground on reef in Prince William Sound in Alaska

• Released 11 million gallons of oil

• Killed 1,000’s of birds and other wildlife

• Ruined fishing industry in the area

• Fined $3 billion dollars• Now ships required to have

double hull (outer layer of metal) around oil containers in ship.

Deepwater Horizon BP Oil Spill

• April 2010• Largest accidental marine oil

spill in history• After an explosion and fire on

the oil rig, 210 million gallons of oil leaked from broken pipe under water for 87 days

• Affected marine fisheries, people’s jobs, wildlife, killed 11 people.

• As of 2013, BP has been fined $42.2 billion dollars, lost contracts, and is under government supervision for the next four years.

Top: oil slick as seen from NASA

Bottom: tar balls washed up on beach

How are oil spills cleaned up?

• Try to contain the spill using floating boom.

• Skimmer boats separate oil from water. Hold oil until it can be disposed of.

• May burn it off• Bioremediation- add

genetically engineered bacteria to eat the left over oil.

Plastic in the Ocean Environment

• Plastic:• Not biodegradable• Plastic floats

• sea turtles mistake it for jellyfish and eat it

• Plastic cannot be digested, turtle feels full, stops eating, and starves.

• Plastic can entangle ocean animals

Great Pacific Garbage Patch

Great Pacific Garbage Patch Video

What laws are established to protect our water quality?• Clean Water Act (1972)

• Restore & maintain the chemical, physical, & biological integrity of our nation’s waters; make them fishable & swimmable by 1983

• Safe Drinking Water Act (1975)• Established standards for drinking

water contaminants

• Comprehensive Environmental Response Compensation & Liability Act (CERCLA) (1980)• AKA Superfund Act• Makes owners, operators, consumers

of hazardous waste sites responsible for cleanup

• Oil Pollution Act (1990)• Required all oil tankers entering US

waters to have double hull.

You should be able to…• Explain why point-source pollution is easier to

control than nonpoint-source pollution• List the major types of water pollutants. Suggest

ways to reduce the levels of each of type of pollutant in a water supply

• Describe the unique problems of cleaning up groundwater pollution.

• Describe the sources of most ocean pollution. Is it point-source pollution or non-point source pollution?