Water Pollution

What Are the Causes and Effects of Water Pollution?

Water pollution causes illness and death in humans and other species and disrupts ecosystems. The chief sources of water pollution are agricultural activities, industrial facilities, and mining, but growth in population and resource use make it increasingly worse.

Water pollution
Classes of pollution, pollutants
Pathogens, parasites Oxygen-demanding wastes Inorganic chemicals Inorganic plant nutrients Organic chemicals Sediments Radioactive material Heat (thermal pollution)

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Water pollution
Pathogens, parasites
Usually from sewage, feedlots, slaughterhouses Viruses Bacteria (cholera, ...)
Coliform bacteria usually not pathogenic, Used as indicators of pollution

Protozoan parasites (Giardia, Cryptosporidium)

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Water pollution
Oxygen-demanding wastes
Organic materials from sewage, slaughterhouses, etc. Decomposed by bacteria
Bacteria require, consume dissolved oxygen

Biological Oxygen Demand (BOD)

Measure of water quality Low in pristine water

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Water pollution
Inorganic chemicals
Mostly from industry Heavy metals
Lead, arsenic, mercury, copper ions, etc.

Ammonia Acids
Sulfuric acid, nitric acid from acid deposition Also from industry

Bases (caustic alkalines)

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Water pollution
Inorganic plant nutrients (fertilizers)
From agriculture, lawns & gardens
Leaching into groundwater Run-off into surface waters

Stimulate growth of algae (algal blooms), eutrophication

Algae die, sink, become oxygen-demanding waste

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Water pollution
Inorganic plant nutrients (fertilizers)
From agriculture, lawns & gardens Eutrophication
Natural process Accelerated by excess nutrient input Algae die, sink, become oxygen-demanding waste

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Water pollution
Organic chemicals
from industry, restaurants, cars, households, farms Gasoline, oil Engine coolant (ethylene glycol) Solvents Detergents Pesticides
insecticides, herbicides, fungicides

Polychlorinated Biphenyls (PCBs)

11 June 2010 Water-Pollution.ppt 9

Water pollution
Sediments
Erosion from construction sites, streets & roads, farms, sewage Dense sediments sink, accumulate
Sedimentation in reservoirs

Less dense sediments may stay in water

Reduce clarity (increase turbidity) Reduce light penetration & photosynthesis

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Water pollution
Radioactive material
From spills, waste from atomic weapons production
Hanford, Washington Savannah River Plant, South Carolina

From nuclear power plants (minor)

Closely regulated

Heat (thermal pollution)

Heated water from cooling of electrical generating equipment Alters ecosystem of river, lake

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Water Pollution Comes from Point and Nonpoint Sources

Point sources Located at specific places Easy to identify, monitor, and regulate Examples (drain pipes, ditches, sewer lines).

Nonpoint sources Broad, diffuse areas Difficult to identify and control Expensive to clean up Examples (atmospheric deposition, agricultural / industrial / residential runoff)

Water Pollution Comes from Point and Nonpoint Sources

Agriculture activities: leading cause of water pollution
Sediment eroded from the lands Fertilizers and pesticides Bacteria from livestock and food processing wastes

Other sources of water pollution

Parking lots Human-made materials - plastics Global Warming ocean acidification

Point Source of Polluted Water in

Nonpoint Sediment from Unprotected Farmland Flows into Streams

Major Water Pollutants Have Harmful Effects

The World Health Organization (WHO)
3 Million people die every year, mostly under the age of 5

Major Water Pollutants and Their Sources

Common Diseases Transmitted to Humans through Contaminated Drinking Water

Major Water Pollutants and Their Effects

A fecal coliform bacteria test is used to indicate the likely presence of diseasecausing bacteria in water.

Water Quality as Measured by Dissolved Oxygen Content in Parts per Million

Fig 20-a

What Are the Major Water Pollution Problems in Streams and Lakes?
While streams are extensively polluted worldwide by human activities, they can cleanse themselves of many pollutants if we do not overload them or reduce their flows. Addition of excessive nutrients to lakes from human activities can disrupt lake ecosystems, and prevention of such pollution is more effective and less costly than cleaning it up.

Pollution of Streams

Oxygen sag curve

Fig. 20-5

Pollution of Lakes
Eutrophication
Discharge of untreated municipal sewage (nitrates and phosphates) Nitrogen compounds produced by cars and factories

Discharge of detergents ( phosphates)

Natural runoff (nitrates and phosphates Manure runoff From feedlots (nitrates and Phosphates, ammonia)

Runoff from streets, lawns, and construction Lake ecosystem lots (nitrates and nutrient overload phosphates) and breakdown of chemical cycling Runoff and erosion Dissolving of (from from cultivation, nitrogen oxides mining, construction, (from internal combustion and poor land use) engines and furnaces)

Discharge of treated municipal sewage (primary and secondary treatment: nitrates and phosphates)

Fig .22.7, p. 499

Dilution and Decay of Degradable, Oxygen-Demanding Wastes in a Stream

Natural Capital Degradation: Highly Polluted River in China

Trash Truck Disposing of Garbage into a River in Peru

Cultural Eutrophication
Eutrophication: the natural nutrient enrichment of a shallow lake, estuary or slow moving stream, mostly from runoff of plant nutrients from the surrounding land. Cultural eutrophication: human activities accelerate the input of plant nutrients (mostly nitrate- and phosphate-containing effluents) to a lake.
85% of large lakes near major population centers in the U.S. have some degree of cultural eutrophication.

Cultural Eutrophication Is Too Much of a Good Thing

Prevent or reduce cultural eutrophication
Remove nitrates and phosphates Diversion of lake water

Clean up lakes
Remove excess weeds Use herbicides and algaecides; down-side? Pump in air

The Great Lakes of North America

20-3 Pollution Problems Affecting Groundwater, Other Water Sources

Concept 20-3A Chemicals used in agriculture, industry, transportation, and homes can spill and leak into groundwater and make it undrinkable. Concept 20-3B There are simple ways and complex ways to purify drinking water, but protecting it through pollution prevention is the least expensive and most effective strategy.

POLLUTION OF GROUNDWATER
It can take hundreds to thousand of years for contaminated groundwater to cleanse itself of degradable wastes.
Nondegradable wastes (toxic lead, arsenic, flouride) are there permanently. Slowly degradable wastes (such as DDT, PCB, Polybrominated diphenylethers PBDEs = flame retardant) are there for decades.
EPA on PBDEs EPA on PCBs

Ocean Futures Society on flame retardants

Principal Sources of Groundwater Contamination in the U.S.

Groundwater Contamination from a Leaking Gasoline Tank

POLLUTION OF GROUNDWATER
Leaks from a number of sources have contaminated groundwater in parts of the world.
According the the EPA, one or more organic chemicals contaminate about 45% of municipal groundwater supplies. The EPA has completed the cleanup of 297,000 of 436,000 underground tanks leaking gasoline, diesel fuel, home heating oil, or toxic solvents.

Groundwater Pollution Prevention

Monitoring aquifers Strictly regulating hazardous waste disposal

Storing hazardous materials above ground

Industry Nitrogen oxides from autos and smokestacks, toxic chemicals, and heavy metals in effluents flow into bays and estuaries.

Cities Toxic metals and oil from streets and parking lots pollute waters;

Urban sprawl Bacteria and viruses from sewers and septic tanks contaminate shellfish beds

Construction sites Sediments are washed into waterways, choking fish and plants, clouding waters, and blocking sunlight.

Farms Runoff of pesticides, manure, and fertilizers adds toxins and excess nitrogen and phosphorus.
Closed shellfish beds Closed beach Oxygen-depleted zone Red tides Excess nitrogen causes explosive growth of toxicmicroscopic algae, poisoning fish and marine mammals.

Toxic sediments Chemicals and toxic metals contaminate shellfish beds, kill spawning fish, and accumulate in the tissues of bottom feeders.

Oxygen-depleted zone Sedimentation and algae overgrowth reduce sunlight, kill beneficial sea grasses, use up oxygen, and degrade habitat.

Healthy zone Clear, oxygen-rich waters promote growth of plankton and sea grasses, and support fish. Fig. 21-10, p. 505

Fox Canyon Groundwater Management Agency

Click for link

Ventura County Watershed Protection District

In July 2000, the L.A. Regional Water Quality Control Board required Ventura County to control stormwater and urban runoff. The Ventura Countywide Stormwater Quality Management Plan allows the County to execute a number of pollution prevention related policies and Best Management Practices. The Plan has 6 sub-plans. The Plan develops Total Maximum Daily Load (TMDL). See link below for TMDL info Click for VCWPD information about Stormwater Quality Click for Stormwater Quality Management Program

Nitrate Pollution in Oxnard

Nitrate pollution in Oxnard

SOLUTIONS
Groundwater Pollution Prevention
Find substitutes for toxic chemicals Keep toxic chemicals out of the environment Install monitoring wells near landfills and underground tanks Require leak detectors on underground tanks Ban hazardous waste disposal in landfills and injection wells Store harmful liquids in aboveground tanks with leak detection and collection systems

Cleanup
Pump to surface, clean, and return to aquifer (very expensive)

Inject microorganisms to clean up contamination (less expensive but still costly)

Pump nanoparticles of inorganic compounds to remove pollutants (still being developed)

Fig. 20-13, p. 545

There Are Many Ways to Purify Drinking Water

Reservoirs and purification plants Process sewer water to drinking water

Expose clear plastic containers to sunlight (UV)

Nanofilters The LifeStraw

The LifeStraw: Personal Water Purification Device

Using Laws to Protect Drinking Water Quality

1974: U.S. Safe Drinking Water Act
Sets maximum contaminant levels for any pollutants that affect human health Need plan to develop best management practices.

Health scientists: strengthen the law Water-polluting companies: weaken the law

Is Bottled Water the Answer?

Some bottled water is not as pure as tap water and costs much more.
1.4 million metric tons of plastic bottles are thrown away. Fossil fuels are used to make plastic bottles.
The oil used to produce plastic bottles in the U.S. each year would fuel 100,000 cars.

What Are the Major Water Pollution Problems Affecting Oceans?

Concept 20-4A The great majority of ocean pollution originates on land and includes oil and other toxic chemicals and solid wastes, which threaten aquatic species and other wildlife and disrupt marine ecosystems. Concept 20-4B The key to protecting the oceans is to reduce the flow of pollutants from land and air and from streams emptying into these waters.

Ocean Pollution Is a Growing and Poorly Understood Problem

2006: State of the Marine Environment
80% of marine pollution originates on land Sewage Coastal areas most affected

Deeper ocean waters

Dilution Dispersion Degradation

Ocean Pollution Is a Growing and Poorly Understood Problem

U.S. coastal waters
Raw sewage Sewage and agricultural runoff: NO3- and PO43Harmful algal blooms Oxygen-depleted zones

Residential Areas, Factories, and Farms Contribute to Pollution of Coastal Waters

Fig 20-15

A Large Zone of Oxygen-Depleted Water in the Gulf of Mexico Due to Algal Blooms

SOLUTIONS
Coastal Water Pollution Prevention
Reduce input of toxic pollutants Separate sewage and storm lines Ban dumping of wastes and sewage by ships in coastal waters Ban ocean dumping of sludge and hazardous dredged material Regulate coastal development, oil drilling, and oil shipping Require double hulls for oil tankers Use nanoparticles on sewage and oil spills to dissolve the oil or sewage (still under development) Require secondary treatment of coastal sewage Use wetlands, solaraquatic, or other methods to treat sewage
Fig. 20-17, p. 551

Cleanup
Improve oil-spill cleanup capabilities

How Can We Best Deal with Water Pollution?

Reducing water pollution requires preventing it, working with nature to treat sewage, cutting resource use and waste, reducing poverty, and slowing population growth.

Water Quality
Improvement since 1970
Surface waters no longer regarded as open sewers
More and better sewage treatment systems Less dumping of industrial waste

Clean Water Act of 1972, 1977

Make all U.S. surface waters fishable and swimmable,
Goal not fully met

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We Need to Reduce Surface Water Pollution from Nonpoint Sources

Reduce erosion
Keep cropland covered with vegetation

Reduce the amount of fertilizers Plant buffer zones of vegetation Use organic farming techniques Use pesticides prudently Control runoff Tougher pollution regulations for livestock operations Deal better with animal waste

Sewage Treatment Reduces Water Pollution

Septic tank system Wastewater or sewage treatment plants
Primary sewage treatment
Physical process

Secondary sewage treatment

Biological process

Tertiary or advance sewage treatment

Bleaching, chlorination

Solutions: Septic Tank System

Solutions: Primary and Secondary Sewage Treatment

Technological Approach: Using Wetlands to Treat Sewage

(

Sewage Wetland type plants Wetland type plants

Treated water

First concrete pool

45 centimeter layer of limestone gravel coated with decomposing bacteria

Second concrete pool

Tertiary Wastewater Treatment

General Industrial RO Systems

Ultraviolet (UV) Disinfection Equipment

Link to SIEMEMS for technology

Oxnard GREAT Project Tertiary Water Treatment

Treat waste water and salty groundwater. Offset the amount of potable water needed for irrigating crops, golf courses and lawns. Seawater intrusion barrier $200 million to build. Produce 28,000 acre feet per year. Click for Oxnard GREAT program

Solutions: Ecological Wastewater Purification by a Living Machine, RI, U.S.

Reducing Water Pollution through Sewage Treatment

Natural and artificial wetlands and other ecological systems can be used to treat sewage.
California created a 65 hectare wetland near Humboldt Bay that acts as a natural wastewater treatment plant for the town of 16,000 people.
The project cost less than half of the estimated price of a conventional treatment plant.

Standard definitions used in Oxnard report that follows.

Maximum Contaminant Level (MCL) = The highest level of a contaminant that is allowed in drinking water. Primary MCLs are set as close to the PHGs (orMCLGs) as is economically and technologically feasible.
Maximum Contaminant Level Goal (MCLG) = The level of a contaminant in drinking water below which there is no known or expected risk to health. MCLGs are set by the U.S. Environmental Protection Agency.

Using Laws to Protect Drinking Water

The U.N. estimates that 5.6 million Americans drink water that does not meet EPA standards. 1 in 5 Americans drinks water from a treatment plant that violated one or more safety standard. Industry pressures to weaken the Safe Drinking Act:
Eliminate national tests and public notification of violations. Allow rights to pollute if provider cannot afford to comply.

Solutions: Water Pollution, Methods for Preventing and Reducing Water Pollution

Fig 20-20

What Can You Do? Water Pollution, Ways to Help Reduce Water Pollution