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AP Environmental Science

Mr. Grant

Lesson 73

Fresh Water Pollution and Its Control

&

Wastewater and Its Treatment

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Objectives:

• Define the terms point-source pollution and non-point-source pollution.

• Assess problems of water quality and propose solutions to address water pollution.

• Explain how we treat drinking water and wastewater.

• TED - Too much of the world lacks access to clean drinking water. Engineer Michael Pritchard did something about it -- inventing the portable Lifesaver filter, which can make the most revolting water drinkable in seconds. An amazing demo from TEDGlobal 2009.

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Point-Source Pollution:

Non-Point-Source Pollution:

Define the terms point-source pollution and non-point-source pollution.

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Assess problems of water quality and propose solutions to address water pollution.

• Water pollution stems from point sources and nonpoint sources.

• Water pollutants include toxic chemicals, sediment, thermal pollution, excessive nutrients, and microbial pathogens,

• Scientists who monitor water quality use biological, chemical, and physical indicators.

• Groundwater pollution can be more persistent and difficult to address than surface water pollution.

• Preventing water pollution is better than mitigation.

• Legislation and regulation have improved water quality in developed nations in recent decades.

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Freshwater pollution and its control

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Point and nonpoint sources of pollution

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Freshwater pollution sources

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Nutrient pollution

The Dümmer See, a lake in Germany's Lower Saxony, suffers from heavy nutrient pollution.

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Eutrophication is a natural process, but…

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Pathogens and waterborne diseases

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Pathogens cause human health problems

Pathogens that can be spread through drinking water

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Toxic chemicals

Many of these chemicals are potentially harmful and can spawn health problems.

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Sediment pollution

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Thermal pollution

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Indicators of water quality

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Groundwater pollution is a difficult problem

So far, the EPA has cleaned up 388,000 leaking tanks

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Sources of groundwater pollution

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Agriculture and industry pollute groundwater

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It is best to prevent pollution

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Legislative efforts reduce pollution

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Enforcement of water quality is decreasing

Chart comparing Virginia's population growth to its CZMA funding level.

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Explain how we treat drinking water and wastewater.

• Municipalities treat drinking water by filtering and disinfection in a multistep process.

• Septic systems are used to treat wastewater in rural areas.

• Wastewater is treated physically, biologically, and chemically in a series of steps at municipal wastewater treatment facilities.

• Artificial wetlands enhance wastewater treatment while restoring habitat for wildlife.

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We treat our drinking water

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We treat our wastewater

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Municipal sewer systems

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A typical wastewater treatment facility

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Artificial wetlands clean wastewater

The U.S. has over 500 artificially constructed or restored wetlands

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TED Video

With cutting-edge nanotech, Michael Pritchard's Lifesaver water-purification bottle could revolutionize water-delivery systems in disaster-stricken areas around the globe.

"On the outside, it looks like an ordinary sports bottle. On the inside, there's a miracle: an extremely advanced filtration system that makes murky water filled with deadly viruses and bacteria completely clean in just seconds."

Allison Barrie, FoxNews.com

Michael Pritchard's water filter turns filthy water drinkable (9:29)