All rivers in Alabama flow to

the Gulf of Mexico.

Bellringer What is “water pollution”? Is a cup of coffee polluted water? Is a muddy stream polluted? “Can I Drink the Water?”

The tap A spring or well A mountain stream A nearby creek or lake A drainage ditch after a heavy rain

Water PollutionWater PollutionSection 11.3Section 11.3

Objectives:1. Classifying sources of water pollution as point and nonpoint..

2. Identify major contaminants in water resulting from natural

phenomena, homes, industry, and agriculture.

3. Describing the eutrophication of water by industrial effluents and

agricultural runoffs.

Water Pollution:

Def: The introduction of chemical, physical, or biological agents into water that degrade water quality and adversely affect the organisms that depend on the water.

Almost all of the ways we use water pollute it.

Two Types of Pollution Sources

1. Point source pollution – discharged from a single source

Septic tanks Unlined landfills Leaking storage tanks Polluted water from mines Industries Waste-water treatment plants Leaking oil tankers

Point Source Pollution

Two Types of Pollution Sources (cont.)

2. Nonpoint source pollution – many different sources; hard to identify Chemical runoff from roadways Runoff from city streets Pesticides and other chemicals from

lawns, golf courses, and farmland Runoff from livestock feedlots Rain containing air pollutants Runoff from farms and construction

sites Oil and gas from personal watercraft

Nonpoint Source

Pollution

Point or Nonpoint?

The Trucking Company in last week’s Pollution Tracking activity

Parking lot runoff Untreated sewage Runoff from feedlots A restaurant’s drainage pipe

emptying runoff into a river The litter in storm runoff Acid precipitation

Pollutant Types and Sources

(Table 5, p.286)

Wastewater Treatment Compare to steps in Section 11.2 notes Primary Treatment:

1. Filtration – ???2. First settling tank - smaller particles

settle to the bottom of the tank and from sewage sludge

Secondary Treatment:3. Aeration – wastewater mixed with oxygen

and bacteria4. Second settling tank – 5. Chlorination – chlorine added to water

Wastewater Not all harmful substances are

removed in wastewater treatment plants.

Crytosporidium outbreak (1993, Milwaukee) Waterborne parasite that causes

flulike symptoms 100 deaths; 400,000 sickened Outbreak probably caused by heavy

rainfall and agricultural runoff overburdening treatment plants (OXFORD!)

Wastewater (cont.) Sewage sludge –

Def.: solid material left AFTER treatment MAY be hazardous waste if high

concentrations of toxic chemicals are present

May be incinerated, then ashes buried in a secure landfill (EXPENSIVE)

Possible uses: fertilizer, combine with clay to make building bricks

Artificial Eutrophication

“Too much of a good thing is not a good thing.”

Mineral nutrients are needed in aquatic ecosystems.

Eutrophication: Natural process Too many decaying organisms use up

oxygen in the water. The organisms living in the water

change, and eventually the water body fills in.

Artificial Eutrophication (cont.)

The natural process is accelerated when phosphorous and nitrogen are introduced by: Fertilizers – largest source Sewage Phosphates from detergents

Thermal Pollution Can be caused by power plants

and industries using water for cooling systems.

Increased temperatures cause lower oxygen levels.

Groundwater Pollution

Anything that can seep into the groundwater can pollute it!

Common pollutants: Pesticides and herbicides Fertilizers Petroleum products – gasoline and

heating fuels from leaking underground storage tanks

Remember, groundwater recharges VERY SLOWLY. Decontamination also can take HUNDREDS of years.

Ocean Pollution Causes? Cruise ships can legally dump

wastewater and garbage in some parts. 85% from land activities Oil spills – dramatic, but responsible for

only 5% of oil pollution in the ocean 1989 – Exxon Valdez – Alaska 2001 – Galapagos Islands 37 million gallons each year; land runoff of

oil accounts for 200-300 million gallons/year!

Beach Sweeps

Cuyahoga River – Cleveland, Ohio (1969)

Cleaning Up Water Pollution

Clean Water Act (1972) Goal: to make all surface water clean

enough for fishing and swimming by 1983

30% more lakes and rivers are now suitable for swimming and fishing

Marine Protection, Research, and Sanctuaries Act (1972) – strengthened laws against ocean dumping

Safe Drinking Water Act (1975) – public right-to-know laws

Oil Pollution Act (1990) – requires all oil tankers in U.S. waters to have double hulls by 2015