A W E B Q U E S TT A G E A R T H S C I E N C E

USING WATER WISELY 11-4

DEAR STUDENTS

• Dear Students,• Please read each slide carefully. You are to read for

understanding and learning. We will discuss these concepts in class this week. • This power point is about “Using Water Wisely”. The

information is also in chapter 11, section 4 of your textbook. • Homework: Finish your flash cards. They are due tomorrow.

STANDARDS

• S6E3.a Explain that a large portion of the Earth’s surface is water, consisting of oceans, rivers, lakes, underground water, and ice.• S6E5.i Describe methods for conserving natural resources

such as water, soil, and air.

FRESH WATER

• Did you know that you are almost 65% water? You depend on clean, fresh drinking water to maintain that 65% of you. But there is a limited amount of fresh water available on Earth. Only 3% of Earth’s water is drinkable.

• And of the 3% of Earth’s water that is drinkable, 75% is frozen in the polar icecaps. This frozen water is not readily available for our use. Therefore, it is important that we protect our water resources.

Click on the link below and follow the directions. Just look at the page that comes up and play the game.

• http://www.fcwa.org/story_of_water/html/earth.htm

WATER POLLUTION

• Surface water, such as the water in rivers and lakes, and groundwater can be polluted by waste from cities, factories, and farms. Pollution is the introduction of harmful substances into the environment. Water can become so polluted that it can no longer be used or can even be deadly.

POINT-SOURCE POLLUTION

• Pollution that comes from one specific site is called point-source pollution. For example, a leak from a sewer pipe is point-source pollution. In most cases, this type of pollution can be controlled because its source can be identified. (You can “patch it up”.)

NONPOINT-SOURCE POLLUTION

• Nonpoint-source pollution, another type of pollution, is pollution that comes from many sources. This type of pollution is much more difficult to control because it does not come from a single source. (You cannot simply “patch it up”.)

• Most nonpoint-source pollution reaches bodies of water by runoff. The main sources of nonpoint-source pollution are street gutters, fertilizers, eroded soils and silt from farming and logging, drainage from mines, and salts from irrigation.

HEALTH OF A WATER SYSTEM

• You might not realize it, but water quality affects your quality of life as well as other organisms that depend on water.

• Therefore, it is important to understand how the properties of water influence water quality.

DISSOLVED OXYGEN

• Just as you need oxygen to live, so do fish and other organisms that live in lakes and streams. The oxygen dissolved in water is called dissolved oxygen, or DO. Levels of DO that are below 4.0 mg/L in fresh water can cause stress and possibly death for organisms in the water.

DISSOLVED OXYGEN

• Pollutants such as sewage, fertilizer runoff, and animal waste can decrease dissolved oxygen (DO) levels. • Temperature changes also affect DO levels. For example, cold

water holds more oxygen than warm water does. • Facilities such as nuclear power plants can increase the

temperature of lakes and rivers when they use the water as a cooling agent. Such an increase in water temperature is called thermal pollution, which causes a decrease in DO levels.

DISSOLVED OXYGEN TEST KITS

These are even made for home aquariums!

NITRATES

• Nitrates are naturally occurring compounds of nitrogen and oxygen. • Small amounts of nitrates in water are normal. However,

elevated nitrate levels in water can be harmful to organisms. • An excess of nitrates in lakes and rivers can also lower DO

levels. Nitrate pollution can come from animal wastes or fertilizers that seep into groundwater.

NITRATES

NITRATE POLLUTION IN THE U.S.

ALKALINITY

• Alkalinity refers to the water’s ability to neutralize acid. Acid rain and other acid wastes can harm aquatic life. • A pH below 6.0 is too acidic for most aquatic life.

WATER TREATMENT PLANT

Sewage treatment planes are facilities that clean the waste materials out of water.

STEPS IN PRIMARY TREATMENT

• When water reaches a sewage treatment plant, it is cleaned in two ways. First, it goes through a series of steps known as primary treatment.

1. Dirty water is passed through a large screen to catch solid objects, such as paper, rags, and bottle caps.

2. The water is then placed in a large tank, where smaller particles, or sludge, can sink and be filtered out.

3. These particles include things such as food, coffee grounds, and soil. Any floating oils and scum are skimmed off the surface.

STEPS IN SECONDARY TREATMENT

• 1. The water is sent to an aeration tank, where it is mixed with oxygen and bacteria. The bacteria feed on the wastes and use the oxygen. • 2. The water is then sent to another settling tank, where

chlorine is added to disinfect the water. • 3. The water is finally released into a water source—a river, a

lake, or the ocean.

WATER TREATMENT

WATER TREATMENT PLANT

SEPTIC TANK

• If you live in an area that does not have a sewage treatment plant, your house probably uses a septic tank.• A septic tank is a large underground tank that cleans the

wastewater from a household.

SEPTIC TANK

• 1. Wastewater flows from the house into the tank, where the solids sink to the bottom. • 2. Bacteria break down these wastes on the bottom of the

tank. • 3. The water flows from the tank into a group of buried pipes.

How a septic tank works:

SEPTIC TANK (CONT’D)

• 4. Then, the buried pipes, called a drain field, distribute the water. Distributing the water enables the water to soak into the ground.

SEPTIC TANK PUMPING

A CROSS-SECTION OF A SEPTIC TANK

WHERE WATER GOES

• Click on the website below to read about how water is used indoors. You will need to read the information carefully to answer the questions on your notes page.

http://www.epa.gov/watersense/our_water/water_use_today.html

WATER IN INDUSTRY

• About 19% of water in the world is used for industrial purposes.

• Water is used for these industrial purposes:Manufacturing goodsCooling power stationsCleaning industrial productsExtracting mineralsGenerating energy for factories

WATER IN AGRICULTURE

• The Ogallala Aquifer is the largest known aquifer in North America. It runs beneath the ground through eight states from South Dakota to

Texas. It provides water for approximately 1/5 of the cropland of the United

States. Recently, the water table had dropped in this aquifer

Click on the link below to see a real time update of the major aquifers of the United States. Notice the largest aquifer area of the US- The Ogallala Aquifer, part of the High Plains Aquifer System, is a vast yet shallow underground aquifer located beneath the Great Plains in the United States.

http://groundwaterwatch.usgs.gov/default.asp

WATER CONSERVATION

• Click on the link below to learn about water conservation. You will use this website to answer questions in the water conservation section on your notes page.

• http://www.epa.gov/watersense/kids/index.html

BRAINPOP

• Watch the BrainPop on “Water Pollution” and do the quiz. • www.brainpop.com• User ID: webbbridge• Password: wbms

• When you finish that you can watch the “Groundwater” Brainpop

HOMEWORK FOR WEDNESDAY 10/23

• Finish your flash cards

• Our test will be on Friday, November 1st.

• Reminders: Tomorrow we will meet in the classroom. Friday 10/25, we will meet in computer lab 141 (by the clinic).