Water Pollution

Unit 12

Water

H2O

A compound

Earth

25% land75% water

Milk Jug Demonstration

• 97% of the Earth’s water is saltwater.• 3% is freshwater.–¾ of freshwater is frozen in polar icecaps.–That means only 1% of the water on Earth is usable!

Water on the Planet

• Hydrosphere: all water on earth• Cryosphere: the frozen part

of the earth

Part I: Surface Water

•Definition:–Fresh water that is above ground in lakes, ponds, rivers, and streams.

Part I: Surface Water

•Watershed: –The entire area of land that is drained by a river.

Part I: Surface Water

•Problems with rivers:–40% of the world’s people rely on water that originates in other countries!

Part I: Surface Water

•Turkey is building dams that will reduce the amount of water that flows to Syria and Iraq.

Water rights problems will worsen as population increases.

Dams

• The water behind a dam forms a reservoir (artificial lake) can hurt fish populations.

– Reservoirs are used for drinking, manufacturing, irrigation, flood control, and electricity.

Part II: Groundwater

•Definition–Water that seeps into the ground and is stored. Makes millions of years to collect.

Part II: Groundwater

•Recharge Zone–Area of land from which groundwater originates.

Part II: Groundwater

•Aquifer–Groundwater stored in underground rock formations. Runs out with overuse.

Part III: Water Shortage Solutions

•Desalinization–Desalting the sea–Provides drinking water in Saudi Arabia and parts of California.–Very expensive

Part III: Water Shortage Solutions

•Towing Water–Used to transport icebergs–Problems•Hard to tow•Melts rapidly• Transportation on land

Part III: Water Shortage Solutions

•Reverse Osmosis–The process of removing minerals from water.–Uses water pressure and permeable membranes.

Water

Current Water Uses

•Agriculture• Industry•Homes•Mining

Can you think of more?

Can you think of the

greatest use?

Water Conservation

•Amount of freshwater available at a given time is limited so we must conserve!

How? Good Question!

• Take shorter showers!• Low-flow faucets and shower heads!• Turn the water off when brushing

your teeth or soaping up your hands!• Here are some great sites to help!– http://www.epa.gov/nps/chap3.html– http://www.wateruseitwisely.com/100-wa

ys-to-conserve/index.php– http://www.americanwater.com/49ways.

htm

Freshwater Pollution

• Putting chemical, physical, or biological stuff into water that makes the quality of water go down affects organisms that live in it or drink it!

Causes

• Industrialization and human population explosion.• Both produce waste products that cannot be disposed of as fast as they are produced!

Point Pollution

• Pollution that is discharged from a single source, such as a factory or wastewater.• Or Treatment plant, or an oil

tanker.• Easy to regulate and control.

Why?• Because it is easily identified

and traced.

Nonpoint Pollution

• Pollution that comes from many sources rather than from a specific site (96% of polluted water is from nonpoint pollution).– Reaches bodies of water via streets and storm

sewers.– Pesticides and fertilizers washed off lawns and

farmland.– Animal feces from farms, parks, and city

streets.– Nonpoint regulation is difficult to regulate and

control. Why?

How Water Pollution Affects Ecosystems

Bioaccumulation

•Adding on larger and larger amounts of toxins within animals in the food chain.

Eutrofication

• Too many nutrients in water from decomposing animals, sewage and fertilizer runoff.• Lots of oxygen used up in the process.

Thermal Pollution

• When excessive amounts of heat are added to a body of water.– Power plants and industries use river

water to cool engines and then return heated water back to its source.

– Causes massive fish kills.–Warm water cannot hold as much

oxygen! (suffocation)– Nonpoint pollution hard to control!

WHY?!

Ocean Pollution

Sources

• From polluted rivers or pumped directly.•Oil spills –1989 Exxon Valdez–1991 Gulf War–2010 Gulf of Mexico

1989 Exxon Valdez

• Worst spill in U.S. until 2010• Prince William Sound in Alaska• Tanker grounded on reef – drunken

captain, only one officer on deck, fatigue, • Spilled 257,000 barrels (17 Olympic

size swimming pools)• Some species have still not recovered

Prince William Sound & Exxon Valdez

1991 Gulf War

• Iraqi troops purposely dumped 5.7 million barrels of Kuwaiti oil.

• No immediate cleanup, so oil settled into sediment

• Sandy beaches have recovered, but not marshes.

• Worst oil spill in history

2010 Gulf of Mexico

2010 Gulf of Mexico

• Deep Water Horizon Oil Rig exploded & spilled 5 billion barrels of oil.

• Making it the worst oil spill in the U.S. & history.

• One year later after massive cleanup efforts only some wildlife has recovered.

• The variety of life in the wetlands is still categorized as poor

Prevention

• Laws that prevent discharging oils or plastics, toxic dumping, etc.• Create marine refuges to protect endangered animals.•Double hulls on oil tankers.

Problem

•Who owns the oceans?•Boundaries difficult to set or enforce.

Cleaning Up Water Pollution

• 1972: Clean Water Act–Restore and maintain the chemical, physical and biological integrity of the nation’s waters.–Many toxic metals now removed from wastewater!