Using Water WiselyChapter 11 section 4

S6E5.i Describe methods for conserving natural resources such as

water, soil, and air.

Warm Up: February 9, 2012

• How many types of loads are there? Explain each type.

• You will be able to ……………….…………– Identify two forms of water pollution– Describe two ways that wastewater can be

treated.– Describe how water is used and how water can be

conserved in industry, in agriculture, and at home.

While hiking, you realize your canteen is almost empty. Why should you not fill the canteen with water from the nearby stream?

Even though the water may look clean, it might contain pollutants or bacteria.

Water Pollution

• What is pollution?

• Where does the waste come from?

• The introduction of harmful substances into the environment.

• Cities, factories, and farms

Point-source pollution

• It comes from a specific site.

• It can be controlled because its source can be identified.

Nonpoint-source pollution• It comes from many

sources.• Reaches bodies of water

by runoff. • Examples: street gutter,

fertilizers, eroded soils, salts from

irrigation.

Hardest to

Control

Health of a Water SystemProperties of water influenced by water quality? • Dissolved Oxygen (DO) – this is the

oxygen that is dissolved in water.– Levels below 4.0 mg/L in can

cause stress and death for organisms in the water.

– Sewage, fertilizer runoff, and animal waste can decrease DO levels.

– thermal pollution (increase in water temperature) causes a decrease in DO levels. Ex: nuclear power plants

– Cold water holds more oxygen than warm water

• Nitrates are naturally occurring compounds of nitrogen and oxygen.– Small amounts normal, elevated harmful– Lower DO levels– Examples: animal wastes or fertilizers that seep into

groundwater.

• Alkalinity refers to the water’s ability to neutralize acid.-too much acid (ph below 6.0), harmful to organisms living in water.

Cleaning polluted water

• Sewage treatment plant– A facility that cleans the

waster materials found in water that comes from sewers or drains.

• Septic Tank– A large underground

tank that cleans the wastewater from a household by separating solid waster from liquids.

– Bacteria breaks down the solid waste.

Where is water used?

HomeAverage 100

galper day

Industry19%

Agriculture

Ways to Conserve water>>>>>>Only use water that is needed<<<<<<

• Industry: recycle water• Agriculture: drip

irrigation system• Household:

low-flow shower heads and low-flush toilets, time your showers, only wash dishes and clothes when there is a full load.