WATER POLLUTION

Contaminant vs. Pollutant

• Contaminant- any constituent in the water that is harmful to its end use. (radon, coliform bacteria from animals, arsenic & other metals naturally in rock/soil)

• Pollutant- any constituent in the water that is harmful to its end use and is anthropogenic in origin. (septic waste, gasoline, oil, industrial waste, herbicide/pesticides)

Water PollutionAny chemical, biological and physical

change in water quality that has a harmful effect on living organisms or makes it unusable for agriculture

Point vs. Non-Point Pollution

• Point– Discharged from a specific

location– Usually from a pipe directly

into water– Sources identifiable which

makes it easier to monitor & regulate

– EX: factories, sewage treatment plants, coal mines, oil wells

• Non-Point– Discharged from scattered

or diffuse locations– No specific location where

the discharge came from– Harder to monitor &

regulate; may be episodic• 1st heavy rainfall washes

lots of gas, oil, trash into river

– EX: runoff from feedlots, farm fields, golf courses, lawns, construction sites, logging areas, streets, parking lots, atmospheric deposition (grasshopper effect)

Types of Pollution• Disease-causing Agents – pathogensDisease-causing Agents – pathogens• Oxygen Demanding Agents – organic waste: manure• Water-soluble Inorganic Chemicals – acids, toxic

metals • Inorganic Plant Nutrients – nitrogen and phosphorus• Organic Chemicals – oil, pesticides, detergents• Sediment or Suspended Material – erosion, soil• Water-soluble Radioactive Isotopes – radon uranium• Thermal– electric and nuclear power plants• Genetic Pollution

Disease-Causing Pathogens

• Most serious water pollutant• Types: typhoid, cholera, dysentery, enteritis, polio, hepatitis,

schistosomiasis, filariasis, yellow fever, and esp. malaria.• Sources: untreated or improperly treated human waste; animal

waste from feedlots, fields near waterways• MDC- not as common due to WWTP• LDC- WWTP non-existent or primitive; 80% of illness

contributed to waterborne pathogens and inadequate sanitation• Test for coliform bacteria (live in colon or intestine of humans or

other warm-blooded animals); if coliform bacteria present, assume that infectious pathogens also present

Waterborne Pathogens

Escherichia coli

• Disease symptoms usually are explosive emissions from either end of the digestive tract

Giardia Hepatitis A

Norwalk Virus

Oxygen in Water

• Amt of O2 in water good indicator of water quality• 6ppm supports game fish & other aquatic life.• 2ppm or less supports worms, bacteria, fungi,

decomposers.• How does O2 get into water?

– Dissolves from air– Turbulence over rocks traps air in bubbles– Photosynthesis from algae & plants

• How is O2 removed from water?– Respiration by plants & animals– Chemical processes– A lot by bacteria & other decomposers

Measuring Oxygen in Water• Biological Oxygen Demand (BOD)-

Standard test of the amt of DO consumed by aquatic microorganisms over a 5-day period.– If BOD levels are high, DO levels

are low because there are too many bacteria using O2 in water

• Called Oxygen sag– Pristine waters register 1 mg/l or

less BOD– Sewage water has 20 mg/l or

more.• Dissolved Oxygen Content (DO)-

directly measures O2 content in water with chemicals or electrodes.

• Fast moving waters are more likely to recover from oxygen depleting event because they are able to easily replenish O2 with bubbles.

BOD Effects on Water QualityBOD Effects on Water Quality

All streams have some capability to degrade organic waste. Problems occur when stream is overloaded with biochemical oxygen-demanding waste.

Oxygen sag

Sources of Organic Matter Pollution that lowers DO levels

• Natural inputs-- bogs, swamps, leaf fall, and vegetation aligning waterways.

• Human inputs-- pulp and paper mills, meat-packing plants, food processing industries, and sewage treatment plants.

• Nonpoint inputs-- runoff from urban areas, fertilizer from farms, manure from feedlots.

Inorganic Plant Nutrients

• Eutrophication: occurs naturally over 100’s-1,000’s years

• Cultural Eutrophication- caused by human pollution; occurs over decades

• Sources of cultural eutrophication:– Increased nitrate or

phosphates from sewage, manure, or fertilizer

– Higher temperatures– Increased sunlight

Steps of Cultural Eutrophication

• Nitrogen & phosphorous from fertilizer, manure, sewage enter ecosystem

• Algae bloom- grow excessively• Cover top of water & keep sun out• Algae outcompete each other • Algae die & water plants die b/c get no sunlight• Decomposers use up O2 in water when decomposing

their bodies• Lake becomes hypoxic and fish & other organisms die.• Clear lakes with low biological productivity are called

oligotrophic.• As organisms die and siltation occurs from erosion, lake

fills in & becomes forest

Cultural Eutrophication & Oceans

• Can occur near shore or in bays or estuaries

• “Dead zones” are common– Largest in Gulf of Mexico

near Mississippi River (about 7,000mi2- size of New Jersey)

– Watershed of Mississippi allows lots of fertilizer into river which dumps into Gulf.

Cultural Eutrophication & Oceans

• Red Tide- caused by dinoflagellates that release toxin; shellfish poisonous

• Pfiesteria piscicida– Piscicida means “fish killer”– Most notably found in 1980’s &

90’s off coast of North Carolina & Maryland

– Type of algae that produces toxins when fish enter bloom. Toxins paralyze fish so they can’t escape & produce skin lesions that cause secondary infections leading to death.

– Humans: blurred vision, burning muscles, difficulty breathing, memory loss, major organ damage- just breathing it in is dangerous

Types of Pollution• Disease-causing Agents – pathogens• Oxygen Demanding Agents – organic waste: manure

or sewage• Inorganic Plant Nutrients – nitrogen and phosphorus

• Water-soluble Inorganic Chemicals – Water-soluble Inorganic Chemicals – acids, toxic metals acids, toxic metals

• Organic Chemicals – oil, pesticides, detergents• Sediment or Suspended Material – erosion, soil• Water-soluble Radioactive Isotopes – radon uranium• Thermal– electric and nuclear power plants• Genetic Pollution

Inorganic Pollutantsmetals, salts, acids

• Metals- – Mercury, lead, cadmium, nickel– Persistent; bioaccumulate– Minamata disease- mercury poisoning– South America- use mercury to mine

for gold, mercury now contaminating Amazon river

– Tin was used as antifouling agent on boat hulls but now banned due to negative health effects.

– Cadmium poisoning in Japan from mining & smelting waste-water discharge

– Lead pipes, solder, can cause lead poisoning. Acidic water can leach lead out of pipes.

– Mine drainage & leaching of mining waste

Inorganic Pollutantsmetals, salts, acids

• Salt– Arsenic

• Found naturally in some bedrock (Bengal, India) as insoluble salts

• When they are exposed to air they become soluble & cause problems: inflamed eyes, gastrointestinal problems, scaly skin, skin tumors, anemia, death

– NaCl• Sources: deicing roads,

aquifers used for irrigation• As aquifer becomes depleted,

salt concentrates. When pumped up for irrigation, water evaporates, leaving salt behind making soil unsuitable for crops.

Inorganic Pollutantsmetals, salts, acids

• Sources: metal smelting, coal mining, power plants, petroleum distillation

• Acid leaches out aluminum from soil & rocks harming aquatic life or soil

• See notes on acid rain & acid mine drainage

Organic Chemicals

• Sources: pesticides (atrazine, DDT, dioxins), plastics, pharmaceuticals, oils

• Problems: birth defects, genetic disorders, cancer

• Resistant to degradation; bioaccumulate

• Come from: improper disposal of industrial & household waste, runoff from pesticides from farms, golf courses, etc.

Sediments• Erosion from

– Poor farming & grazing techniques– Urbanization- excessive construction– Deforestation

• Problems caused for people:– Fills in lakes, reservoirs– Obstructs shipping channels– Clogs hydroelectric turbines– Purification of drinking water more expensive– Aesthetic degradation

• Problems caused for ecosystems:– Blocks sunlight; makes water turbid (cloudy)– No photosynthesis- plants die– Less oxygen in water, fish die– Covers gravel which is place some fish & insects

lay eggs• Can be good

– Sediment creates fertile flood plain– Replenishes islands in bays & estuaries

Radioactive Isotopes• Uranium- from mine tailings into

surface water• Plutonium Case Study- Savannah

River Site– 1950’s plutonium reactors built along

river in S.C. Plutonium used for H-bombs

– William Lawless was put in charge of radioactive waste disposal even though he had no prior experience

– He was told to dump high-level water waste in unlined canals and to bury high level solid waste in cardboard boxes. Radioactive waste leached into groundwater supply

– When he questioned this he was told to keep quiet.

– He went public, was fired, and the plutonium reactors have since been shut down.

– Many people affected by rare cancers associated with radiation poisoning

Thermal pollution• Sources:

– Mostly from power plants (especially nuclear)

• Withdraw water, cools systems, discharge hot water if they don’t have cooling towers. Sometimes cooling towers fail & release thermal plumes.

– Removal of vegetation over river for construction

• Now required to keep riparian zone on either side of river

– Concrete/parking lots heat up during day, afternoon rains wash hot water into river

• Effects:– Many fish species sensitive to one

degree change in temp. die– High temps decrease DO levels in

water causing fish suffocation

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.

OCEAN POLLUTION

Ocean Pollution• Coastal areas most impacted –

especially wetlands and estuaries, coral reefs, and mangrove swamps– Heavily used, little circulation

• About 35% of U.S. municipal sewage discharged virtually untreated in ocean waters

• Dumping of industrial waste directly into ocean off U.S. coasts stopped, but many countries still dump large quantities of toxic substances

• Ocean is the ultimate repository of waste

Main Types of Ocean Pollution

• Petroleum (oil)• Sewage sludge• DDT and PCBs• Mercury• Point source: obvious origin- usually pipe

(municipal sewage outfall pipe, oil tanker spills, offshore oil well blowouts)

• Non-point-source pollution: ill-defined or diffused sources, runoff (harbors and marinas, powerboat pollution, invasive species, agriculture, forestry, urban runoff, ocean debris, air pollution, noise pollution, dredging

Ocean Pollution: Petroleum

• Oil spills can be caused by:– Tanker

accidents– Intentional

dumping– Drilling/

pumping operations bss.sfsu.edu/ehines/geog600/ Freshwater%20and

%20ocean%20Pollution.ppt

Effects of Oil Spills• Volatile Organics Compounds

immediately kill many of the aquatic organisms (especially plankton and larvae) and contaminate fish

• Floating oil coats birds and ocean mammal; destroys natural insulation and buoyancy and causes deaths

• Heavy oil sinks to ocean bottom and washes into estuaries where it contaminates crabs, oysters, mussels, clams, etc.

• Oil slicks on beaches harm intertidal life and cause economic losses to tourism and fishing industries

Ocean Pollution: Petroleum

• Petroleum is biodegradable

• Many pollution experts consider oil to be among the least damaging ocean pollutants

• Data from the 1989 Exxon Valdez oil spill shows the recovery of key organismsbss.sfsu.edu/ehines/geog600/ Freshwater%20and

%20ocean%20Pollution.ppt

CASE STUDY: Exxon Valdez• Worst oil spill in U.S. history:

– March 24, 1989 from oil tanker Exxon Valdez in Prince William Sound, Alaska.

– Spilled 11.6 million gallons of oil.

– 3000 miles of coastline polluted.

– Killed 1000’s of birds, mammals, plankton, etc.

– Exxon spent $2.2 billion on direct cleanup + $1 billion fines and damages

– Region will probably be affected for 10-15 more years.

– Now, tankers must have double hull to decrease chance of spills.

Cleaning Up Oil Spills

1. Shoreline

•Wiping with paper towels

•Spraying back into sea w/high powered hose.

2. Open Ocean

•Drop boom to contain oil.

•Burn it off- causes air pollution

•Vacuum it up & separate

•Bioremediation- bacteria “eat” oil

Exxon Valdez only #53????

bss.sfsu.edu/ehines/geog600/ Freshwater%20and%20ocean%20Pollution.ppt

Ocean Pollution: Sewage Sludge

• Sewage sludge is the semisolid material that remains after sewage treatment

• Much sewage sludge was dumped offshore until laws restricted sewage dumping

Ocean Pollution: DDT

• DDT was a widely used pesticide that became concentrated in ocean fish

• DDT caused brown pelicans and ospreys to produce thin egg shells

• Worldwide, DDT has been banned from agricultural use but is still found in developing countries…

• Same general problems with PCB’s but these come from industrial coolants, not pesticide use

Plastic in the Ocean Environment

• Plastic:– Either does not

biodegrade or not in human time…

– Floats- sea turtles mistake it for jellyfish

– Has high strength– Is ingested by and

entangles ocean animals

Plastic Alternatives

• Biodegradable- breakdown with biological organism like bacteria

• Photodegradable- breakdown with light

• Degradable- can be broken down with chemicals