Water PollutionWater Pollution

Water, Air, Land ….Water, Air, Land ….

The solution to pollution is dilution….?

Water makes us unique and gives life to Earth.

Key IdeasKey Ideas

• What are major types and effects of water pollution?

• How do we measure water quality?

• Point versus Nonpoint sources

• What are the major sources of pollution?

What is water pollution?What is 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 usage.

What is water pollution?What is water pollution?WHO:

• 3.4 million premature deaths each year from waterborne diseases

• 1.9 million from diarrhea

• U.S. 1.5 million illnesses

• 1993 Milwaukee 370,000 sick

What is water pollution?What is water pollution?Infectious Agents: bacteria and viruses often

from animal wastes

Oxygen Demanding Wastes: organic waste that needs oxygen often from animal waste, paper mills and food processing.

Inorganic Chemicals: Acids and toxic chemicals often from runoff, industries and household cleaners

Organic Chemicals: oil, gasoline, plastics, detergents often from surface runoff, industries and cleaners

Plant Nutrients: water soluble nitrates, ammonia and phosphates often from sewage, agriculture and urban fertilizers

Sediment: soils and silts from land erosion can disrupt photosynthesis, destroy spawning grounds, clog rivers and streams

Heat Pollution and Radioactivity: mostly from powerplants

What is water pollution?What is water pollution?

How do we measure water qualityHow do we measure water quality

Bacterial Counts: Fecal coliform counts from intestines of animals

• None per 100 ml for drinking

• >200 per 100 ml for swimming

Sources: human sewage, animals, birds, raccoons, etc.

How do we measure water qualityHow do we measure water qualityDissolved Oxygen: BOD

Biological Oxygen Demand…the amount of oxygen consumed by aquatic decomposers

Chemical Analysis: looking for presence of inorganic or organic chemicals

Suspended Sediment: water clarity

Indicator Species: organisms that give an idea of the health of the water body

Point and Nonpoint SourcesPoint and Nonpoint Sources

NONPOINT SOURCES

Urban streets

Suburban development

Wastewater treatment plant

Rural homes

Cropland

Factory

Animal feedlot

POINT SOURCES

Major Sources of Water PollutionMajor Sources of Water PollutionAgriculture: by far the

leader

• Sediment, fertilizers, bacteria from livestock, food processing, salt from soil irrigation

Industrial: factories and powerplants

Mining: surface mining toxics, acids, sediment

• Freshwater pollution: What are major problems in streams?

• Developed versus Developing Countries

• Lake Pollution: Why are lakes and reservoirs more vulnerable?

• What is Eutrophication?

Key questions…

Freshwater Stream PollutionFreshwater Stream PollutionFlowing streams can recover from

moderate level of degradable water pollution if their flows are not reduced.

• Natural biodegradation process

• Does not work if overloaded or stream flow reduced

• Does not work against non biodegradable pollutants

Pollution of StreamsPollution of Streams

Oxygen sag curve Oxygen sag curve Factors influencing recovery Factors influencing recovery

What factors will influence this oxygen sag curve?

Two WorldsTwo WorldsDeveloped CountriesU.S. and other developed

countries sharply reduced point sources even with population and economic growth

• Nonpoint still a problem• Toxic chemicals still

problem• Success Cuyahoga River,

Thames River

Two WorldsTwo Worlds Developing Countries:

Serious and growing problem

• Half of world’s 500 major rivers heavily polluted

• Sewage treatment minimal $$$

• Law enforcement difficult

• 10% of sewage in China treated

• Economic growth with little $$$ to clean up

India’s Ganges RiverIndia’s Ganges River• Holy River (1 million take

daily holy dip)• 350 million (1/3rd of pop) live

in watershed• Little sewage treatment• Used for bathing, drinking etc.• Bodies (cremated or not)

thrown in river• Good news is the Indian

government is beginning to work on problem

Freshwater Lake PollutionFreshwater Lake PollutionDilution as a solution in

lakes less effective• Little vertical mixing• Little water flow

(flushing)Makes them more

vulnerable• Toxins settle• Kill bottom life• Atmospheric deposition• Food chain disruptions

Biomagnifications of PCBs in an aquatic food chain from the Great Lakes.

Eutrophication of LakesEutrophication of LakesEutrophication: nutrient

enrichment of lakes mostly from runoff of plant nutrients (nitrates and phosphates)

• During hot dry weather can lead to algae blooms

• Decrease of photosynthesis• Dying algae then drops DO

levels • Fish kills, bad odor

Eutrophication Eutrophication

Eutrophication in LakesEutrophication in Lakes

Solutions:

• Advanced sewage treatment (N, P)

• Household detergents

• Soil conservation

• Remove excess weed build up

• Pump in oxygen or freshwater

Case Study: The Great LakesCase Study: The Great Lakes•Pollution levels dropped, but long way to go

•95% of U.S. freshwater

•30% Canadian pop, 14% U.S.

•38 million drink

•1% flow out St. Lawrence

•Toxic fish

GroundwaterGroundwater

• Why is groundwater pollution a serious problem?

• What is the extent of the problem?

• What are the solutions?

GroundwaterGroundwaterGroundwater can become

contaminated

• No way to cleanse itself

• Little dilution and dispersion

• Out of sight pollution

• Prime source for irrigation and drinking

• REMOVAL of pollutant difficult

Groundwater Pollution: CausesGroundwater Pollution: Causes

Low flow rates Low flow rates Few bacteria Few bacteria Cold temperatures Cold temperatures

Coal strip mine runoff

Pumping well

Waste lagoon

Accidental spills

Groundwater flow

Confined aquifer

Discharge

Leakage from faulty casing

Hazardous waste injection well

Pesticides

Gasoline station

Buried gasoline and solvent tank

Sewer

Cesspool septic tank

De-icing road salt

Unconfined freshwater aquifer

Confined freshwater aquifer

Water pumping well Landfill

Low oxygen Low oxygen

Prevention is the most effective and cheapest

Ocean PollutionOcean Pollution

• How much pollution can the oceans tolerate?

• Coastal zones: How does pollution affect coastal zones?

• What are major sources of ocean pollution and what is being done?

• Oils spills

Ocean PollutionOcean PollutionOceans can disperse and

break down large quantities of degradable pollution if they are not overloaded.

• Pollution worst near heavily populated coastal zones

• Wetlands, estuaries, coral reefs, mangrove swamps

• 40% of world’s pop. Live within 62 miles of coast

Mangrove Swamp

Estuaries

Ocean PollutionOcean Pollution

• Large amounts of untreated raw sewage (viruses)

• Leaking septic tanks• Runoff• Algae blooms from

nutrients• Dead zones NO DO• Airborne toxins• Oil spills

Ocean PollutionOcean Pollution

Case Study: Chesapeake BayCase Study: Chesapeake Bay

Largest US estuary

Largest US estuary

Relatively shallow Relatively shallow

Slow “flushing” action to Atlantic

Slow “flushing” action to Atlantic

Major problems with dissolved O2 Major problems with dissolved O2

Preventing and reducing the flow of pollution from land and from streams emptying into the ocean is key to protecting oceans

Oil SpillsOil Spills Sources: offshore wells, tankers, pipelines and

storage tanks

Sources: offshore wells, tankers, pipelines and storage tanks

Effects: death of organisms, loss of animal insulation and buoyancy, smothering

Effects: death of organisms, loss of animal insulation and buoyancy, smothering

Significant economic impacts Significant economic impacts

Mechanical cleanup methods: skimmers and blotters

Mechanical cleanup methods: skimmers and blotters

Chemical cleanup methods: coagulants and dispersing agents

Chemical cleanup methods: coagulants and dispersing agents

Oil SpillsOil Spills

Prevention and ReductionPrevention and Reduction

• How can we reduce surface water pollution: point and also nonpoint.

• How do sewage treatment plants work?

• How successful has the U.S. been at reducing water pollution? Clean Water Act

Nonpoint SourcesNonpoint Sources

Reduce runoff

Nonpoint SourcesNonpoint Sources

Buffer Zones Near Streams

NonpointNonpoint

Prevent soil erosion and only apply needed pesticides and fertilizers

Point SourcesPoint SourcesMost developed countries

use laws to set water pollution standards.

Federal Water Pollution Control Act (Clean Water Act 1972, ’77, ’87)

• Regulates navigable waterways, streams, wetlands, rivers, lake

Clean Water ActClean Water Act• Sets standards for key

pollutants• Requires permits for

discharge• Requires sewage treatment• Require permits for

wetland destruction• Does not deal with

nonpoint sources well• Goal All Waterways

fishable and swimable

Technological Approach: Septic SystemsTechnological Approach: Septic Systems

Require suitable soils and maintenanceRequire suitable soils and maintenance

•¼ of all U.S. homes have Septic tanks

•Can be used in parking lots, business parks, etc.

Combined sewer overflow is a problem in many older towns

•EPA: 1.8 M to 3.85 M sick from swimming in water contaminated by sewer overflows

•EPA: $100 billion to fix

Technological Approach: Sewage TreatmentTechnological Approach: Sewage Treatment

Physical and biological treatmentPhysical and biological treatmentFig. 22-16 p. 511

Primary: removes 60% of solids and 30-40% oxygen demanding wastes (physically)

Secondary: uses biological processes to remove up to 90% of biodegradables

Tertiary: advanced techniques only used in 5% of U.S. $$$$

Disinfection: chlorine, ozone, UV

What is not taken out???

Technological Approach: Advanced (Tertiary) Sewage TreatmentTechnological Approach: Advanced (Tertiary) Sewage Treatment

Uses physical and chemical processesUses physical and chemical processes

Removes nitrate and phosphateRemoves nitrate and phosphate

ExpensiveExpensive

Not widely usedNot widely used

Sludge disposal…using as fertilizer

Technological Approach: Using Wetlands to Treat SewageTechnological Approach: Using Wetlands to Treat Sewage

The Good NewsThe Good News

Largely thanks to CWA:• Between 1972 – 2002

fishable and swimmable streams 36% to 60%

• 74% served by sewage treatment

• Wetlands loss dropped by 80%

• Topsoil losses dropped by 1 billion tons annually

The Bad NewsThe Bad News

• 45% of Lakes, 40% streams still not fishable and swimmable

• Nonpoint sources still huge problem

• Livestock and Ag. Runoff• Fish with toxins

Drinking Water Drinking Water

• How is drinking water purified? High tech way.

• How can we purify drinking water in developing nations?

• What is the Safe Drinking Water Act?

• Is bottled water a good answer or an expensive rip-off?

Drinking Water QualityDrinking Water Quality

Safe Drinking Water Act Safe Drinking Water Act

Maximum contaminant levels (MCLs) Maximum contaminant levels (MCLs)

Purification of urban drinking water Purification of urban drinking water

Bottled water Bottled water

Protection from terrorism Protection from terrorism

Purification of rural drinking water Purification of rural drinking water

Safe Drinking Water ActSafe Drinking Water Act• 54 countries have

drinking water laws

SDWA passed 1974 requires EPA to set drinking water standards

Maximum Contaminating Levels (MCLs)

Safe Drinking Water ActSafe Drinking Water Act• Privately owned wells

exempt from SDWA

SDWA requires public notification of failing to meet standards and fine.

MCLs often stated in parts per million or parts per billion

Bottle WaterBottle WaterU.S. has the world’s

safest tap water due to billions of $$$ of investment

Bottle water 240 to 10,000 times more expensive than tap water

25% of bottle water is tap water

Bottle WaterBottle Water1.4 million metric tons of

bottle thrown away each year

Toxic fumes released during bottling

Bottles made from oil based plastics

Water does not need to meet SDWA

This presentation was from an online power point prepared by Richard Clements for G. Tyler Miller’s Living in the Environment 14th edition.