Pre-Visit Activities : Water Quality Sixth - Eighth Grade Online Curriculum : Watersheds

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Focus Question
What is water quality? How is it determined?

Activity Synopsis
Students will learn about water quality by testing the pH, temperature, dissolved oxygen and salinity of water samples in the classroom. Students will then determine the water quality of a local body of water.

Time Frame
Three 45 minute class sessions

Student and Teacher Key Terms

• Water quality
• pH
• Salinity
• Current speed

OBJECTIVES

The learner will be able to:

STANDARDS

Grade Level	Standards
6th Grade	6-1.1, 6-1.2, 6-1.5
7th Grade	7-1.1, 7-1.2, 7-1.3, 7-1.4, 7-1.6, 7-1.7, 7-4.5, 7-5.6, 7-5.10
8th Grade	8-1.1, 8-1.2, 8-1.3, 8-1.4, 8-1.5, 8-1.6, 8-1.7
* Bold standards are the main standards addressed in this activity.

Sixth Grade Indicators

Seventh Grade Indicators

Eighth Grade Indicators

8-1.1	Design a controlled scientific investigation.
8-1.2	Recognize the importance of a systematic process for safely and accurately conducting investigations.
8-1.3	Construct explanations and conclusions from interpretations of data obtained during a controlled scientific investigation.
8-1.4	Generate questions for further study on the basis of prior investigations
8-1.5	Explain the importance of and requirements for replication of scientific investigations.
8-1.6	Use appropriate tools and instruments (including convex lenses, plane mirrors, color filters, prisms, and slinky springs) safely and accurately when conducting a controlled scientific investigation.
8-1.7	Use appropriate safety procedures when conducting investigations.

BACKGROUND
Key Points
Key Points will give you the main information you should know to teach the activity.

• Water quality is the chemical, physical and biological properties of water that affect the living things able to use the water. It can be determined by looking at many factors including temperature, salinity, pH and dissolved oxygen content.
• pH is a measure of how acidic or how basic a water solution is. It is measured on a scale of 0 to 14 with numbers below 7 being acidic and numbers above 7 being basic.
• Salinity is a measure of how much salt is dissolved in the water. It is usually measured in parts per thousand (ppt). For example, the ocean has a salinity of 35ppt. This means there are 35 mL of salt dissolved in every 1000 mL of ocean water.
• Dissolved oxygen content refers to the amount of oxygen molecules dissolved in water. It is expressed as a percentage. Water with 100% dissolved oxygen is completely saturated with oxygen and water with 0% dissolved oxygen has oxygen.

Detailed Information
Detailed Information gives more in-depth background to increase your own knowledge, in case you want to expand upon the activity or you are asked detailed questions by students.

Water quality includes the chemical, physical and biological properties of water. The water quality of a body of water affects the type of life found there.

A water molecule, H₂O, is composed of two hydrogen atoms and one oxygen atom. When water dissociates or separates it forms H⁺ and OH^-.This process is known as ionization. The hydrogen ion, H⁺, has a positive charge because it lost an electron, while the hydroxide ion, OH^-, has a negative charge due to its gaining an electron. When another substance that ionizes is added, acids and bases are formed. An acid is created when excess hydrogen ions are present while a base is formed due to extra hydronium ions. To determine if a substance is acidic or basic, the pH should be determined.

pH is a measure of the hydronium concentration in a water solution. The pH range is 0 to 14. If the solution contains more H⁺ ions it is acidic while one containing more OH^- ions is basic. 

pH can be measured using a variety of methods. pH paper is often used and is simple. There are indicators like phenolphthalein and bromthymol blue, as well as, foods that change colors in the presence of acids and bases.

The pH is one attribute that determines the biotic characteristics of a body of water. Most plants can tolerate a pH range of 6.5 to 13 while a large variety of animals prefer 6.5 to 7.5. For this reason, when the pH drops below the ideal level, many plants and animals become stressed and may die.

Temperature is another attribute that determines the biotic characteristics of aquatic habitats. The temperatures of mountain streams are dramatically different when compared to reservoirs and rivers in other regions of the state. Animals have adapted to different habitats and have specific temperature needs. For example, brook trout prefer water temperatures between 54 and 60 degrees Fahrenheit while menhaden prefer salt water with a temperature range of 59 to 68 degrees. If temperatures vary from the ideal, animals can become stressed.

Salinity is the third attribute that has a profound affect on plants and animals. Salinity is the amount of dissolved salts in water and soil. It is measured as the concentration of dissolved salt in milligrams per liter and may be expressed in parts per thousands (ppt or ⁰/₀₀). The average salinity of the ocean is 35 ⁰/₀₀. The salinity varies near the mouths of rivers where there is the presence of freshwater. It also varies in areas of increased evaporation.

Students frequently ask how salt enters the ocean. As the rivers flow across the land, they pick up salt from the rocks and soil they pass over and carry it until it is then deposited into the ocean. Salt is also added from the sea floor. As evaporation occurs, freshwater is removed leaving salts behind which increase the salinity.

Plants and animals living in the estuaries and salt marshes of South Carolina can tolerate dramatic changes in salinity due to tidal changes that occur throughout the day. Organisms that live in the deep ocean have adapted to a salinity range that is more constant than that of estuaries. Salinity is measured using a hydrometer or a refractometer. Hydrometers may be purchased at local aquarium supply stores and are relatively cheap. The refractometer is somewhat more expensive and may be purchased from a scientific supply company.

Dissolved oxygen, the percentage of oxygen in water, is the fourth attribute that can affect organisms in aquatic habitats. The range varies dramatically, some rivers contain 100 ⁰/₀ dissolved oxygen while others are almost devoid of oxygen. The organisms living in the aquatic habitats are dependent on the oxygen. Without it, they cannot survive. Dissolved oxygen can be measured in a variety of ways; dissolved oxygen kits and dissolved oxygen meters are commonly used. Both items can be purchased through a scientific supply company.

The biotic factors within an aquatic environment are also influenced by current speed, the rate at which the water flows, and water clarity. Current speed can be determined through the use of a biodegradable substance, such as an orange, being placed in the water and measured over a set distance. The speed or velocity can be calculated by dividing the distance the object traveled by time it took. Water clarity is related to the current speed. The fast moving streams of the Mountains and Piedmont carry larger sized sediments. When the water slows, the sediment falls out. The rivers in the Coastal Plain and coastal regions of South Carolina carry a greater sediment load, smaller particle size, than do those of the Mountains and Piedmont. The water clarity decreases as the sediment load increases. To measure the water clarity, a secchi disk may be used or you can make a light penetration apparatus using a glass jar, black construction paper and flashlight.

You may ask, how do temperature, salinity and dissolved oxygen influence each other. The temperature influences salinity and dissolved oxygen. When the air temperature is high, evaporation increases creating a higher salinity. This is evident around the equator. The salinity is generally higher in the polar regions also, due to pure water freezing, leaving a higher salt concentration in the water underneath. Temperature also influences dissolved oxygen. Cool water normally has a higher concentration of dissolved oxygen. The mountain streams of South Carolina are cool, fast moving, highly oxygenated bodies of water. Warmer water has the tendency to have a lower concentration of dissolved oxygen.

All of these factors together influence the water quality of a body of water. What the water quality is determines what organisms will live around the body of water. As water quality changes, the animals that live around the water will change as well.

PROCEDURES

Materials

Part 1
Mini-lab 1

• pH paper
• water
• lemon juice
• vinegar
• soda
• milk
• baking soda
• bleach
• shampoo
• orange juice
• detergent
• cups or beakers
• safety goggles

Mini-lab 2

• glass beakers
• salt
• water
• pH paper
• hydrometer/refractometer
• thermometer
• dissolved oxygen kit or meter
• hot plate
• safety goggles

Part II

• pH paper
• hydrometer or refractometer
• thermometer
• dissolved oxygen kit

Top

Procedure

Part 1

Discuss water quality with your students. Ask them what they think water quality is. Teachers may want to use two photographs, one of a polluted stream and one of a healthy stream. Have students discuss factors that influence water quality. In the discussion focus on temperature, pH, dissolved oxygen and salinity as some of the factors that can be measured to determine water quality.

Mini-lab 1

1. Ask students if they’ve heard of pH. Introduce the terms acid, base and neutral. Discuss the pH scale.
2. Have students determine the pH of five household products. You may choose to use water, soda, vinegar, lemon juice, shampoo, milk, bleach, orange juice, detergent, baking soda or any other product that would be acidic or basic. (Mix baking soda and water to create a solution.)
3. Each group of students should be given five beakers containing the household products listed above. They should determine the pH of each item. Have them record their data in their journal. They should determine if each substance is an acid or base. Remind students to wear safety goggles.

Mini-Lab 2

1. Discuss salinity. Ask students what salinity is, what bodies of water should have greater salinity and where the salt comes from.
2. Have students measure the salinity of two water samples. To create these samples, add salt to a beaker of water. Mix well. To the second beaker add only water. Have students determine the salinity using a hydrometer or refractormeter. These tools can be ordered from a scientific supply company. Students should also measure the temperature, dissolved oxygen and pH of each sample.
3. Next, heat the water samples using a hot plate. Allow evaporation to take place. After the sample has cooled, have students measure the salinity, temperature, dissolved oxygen and pH again. Record results and discuss why changes may have occurred.

Part II
Using information learned during the mini-labs, have students design an experiment to determine the water quality of a local body of water. They may use a drainage ditch, stream, river, pond, etc. Students should include temperature, pH, salinity, and dissolved oxygen. Other factors such as turbidity and stream velocity may also be included.

Follow-up Questions

1. Is pH affected by temperature or the salinity of the water? If so, explain your answer.
2. How does temperature affect dissolved oxygen?
3. Using the data collected on the local body of water, describe factors that may affect the parameters you tested.

ASSESSMENT

Students will write a report of their inquiry experiment. The report should include the following: hypothesis, materials used, description of experiments, recorded data and observations, and a written conclusion describing whether their experiment supported their hypothesis or not.

Scoring Rubric (Out of 5 points):
In their report:

• Write their hypothesis: 1 point
• List materials used: 1 point
• Describe the experiment conducted: 1 point
• Record data and observations collected: 1 point
• Write a conclusion describing whether their experiment supported their hypothesis: 1 point

Cross-curricular Extensions
Social Studies Extension
Students will research the quality of water in their local watershed. They will design a conservation campaign to help clean polluted areas and preserve those areas designed as healthy streams/rivers.

Math Extension
Students will calculate the current speed of a local stream or river at different times throughout the year. They will graph the information and compare the data and discuss the factors that may affect the flow rate.

Language Arts Extension
Students will develop “water quality” pen pals with other students throughout the state. They can share their data collected in this activity and discuss the factors that influence the local stream/body of water. They can share ideas for creating a conservation message to be shared with others.

RESOURCES

Teacher Reference Books
Kovacik, Charles F. and John J. Winberry. South Carolina: the Making of a Landscape, University of South Carolina Press, Columbia, 1989.
This wonderful reference book provides information on the abiotic factors that determine the habitats of South Carolina.

Murphy, Carolyn Hanna. Carolina Rocks!: The Geology of South Carolina, Sandlapper Publishing Co., Inc., Orangeburg, 1995.
Information on the geology, topography and formation of all of the regions in South Carolina.

Plummer, Charles C. and David McGeary. Physical Geology, Wm. C. Brown Publishers, Iowa, 1991.
Though admittedly college textbooks are often a little too dry and in-depth, with their text, photographs and illustrations they are often the best resources for finding information on a particular subject. This college textbook is an excellent resource for anyone wanting to know more about geology.

Watercourse Publications: Discover Ground Water & Springs, Conserve Water, Big Rivers, and the Water Story, The Watercourse, Montana.
These publications provide information and games on a variety of topics. For additional information visit www.montana.edu/wwwwater

Teacher Reference Websites
Chesapeake Bay Foundation Environmental Education
http://www.cbf.org/education/index.htm
The Chesapeake Bay Foundation has put together an exemplary watershed protection program that encompasses many states. This site includes information on what they have done in this program as well as curricula and other education related items.

EPA’S Environmental Education Center
www.epa.gov/teacher
Provides information on water and watersheds and links to other sites.

EPA Office of Water: Office of Wetlands, Oceans and Watersheds
www.epa.gov/owow/
Provides information on watersheds, wetlands, water quality plus much more.

Project WET: Water Education for Teachers
www.montana.edu/wwwwet/
This is the home page for Project WET. Visit this site for on-line information and activities.

South Carolina Department of Health and Environmental Control: Bureau of Water
www.scdhec.net/water
This site offers information on drinking water, water pollution control, watersheds plus much more.

Southern Appalachian Watershed Conservation Clearinghouse
http://sunsite.utk.edu/samab/proj/watershed.html
This site offers links to a number of websites related to watershed conservation in the Southeastern United States.

Surf Your Watershed: A Service to Help You Locate, Use, and Share Environmental Information About Your Place
www.epa.gov/surf
This site allows you to learn specific information related to the watershed your town is located in.

U.S. Geological Survey
www.usgs.gov/
This site offers valuable earth science information on a variety of topics.

Water Science for Schools
http://ga.water.usgs.gov/edu/
Background information on water and watersheds is provided on this site.

Student Reference Books
Cone, Molly. Come Back, Salmon, Sierra Club Books for Children, San Francisco, 1992.
Learn how the students of Jackson Elementary School in Everett, Washington, cleaned a nearby stream, stocked it with salmon and protected it from pollution.

Student Fiction Books
Cherry, Lynne. A River Ran Wild, Gulliver Books/HBJ, San Diego, California,1992.
Follow the environmental history of the Nashua River, from its discovery to present day. Learn how it was polluted during the Industrial Revolution but has since been cleaned.

Curricula
Aquatic Project WILD
Aquatic Project WILD is an interdisciplinary curriculum for K-12 teachers on aquatic wildlife and ecosystems. The activities cover a broad range of environmental and conservation topics. For information on signing up for workshops, call the South Carolina Department of Natural Resources at (803) 734-3814.
For more information click on:
www.dnr.state.sc.us/cec/educate/edu1.html#teacher

JASON Project
The JASON Project is an interdisciplinary curriculum for K-12 teachers focusing on the geology, climate, biology and biodiversity of specific regions in the world. The activities cover a broad range of topics. For information on signing up for workshops, call Karen Talbert at (803) 738-1876.
For more information click on www.jasonproject.org

Project WET
Project WET is an interdisciplinary curriculum for K-12 teachers on water. The activities cover a wide range of water-related topics. For information on signing up for workshops, call the South Carolina Department of Natural Resources at (803) 737-0808.
For more information visit the website at www.montana.edu/wwwwet

SC MAPS
SC MAPS is a standards-based interdisciplinary curriculum for middle school teachers that focus on the geology of the five regions of South Carolina using aerial photographs, images and topographic maps. For information on signing up for workshops call (864) 656-1560.
For more information visit the website at www.ces.clemson.edu/scmaps

Field Trip Sites
South Carolina's Ecoregions
Each of South Carolina's ecoregions contains many parks and preserved land that make watersheds and landforms accessible to school groups. Below is listed one example from each region.

Mountains
Mountain Bridge Wilderness Area (Jones Gap and Caesars Head State Natural Areas) - The Mountain Bridge Wilderness Area covers more than 10,000 acres of exceptional mountain habitat including Jones Gap and Caesars Head state parks. Education at this site strives to foster an understanding and appreciation of the Mountain Bridge, the Southern Appalachian Mountains and the Blue Ridge Escarpment. Through expert instruction and hands-on field experiences, students can investigate the ecology, hydrology and geology of the area. (Greenville County - Caesars Head 864.836.6115; Jones Gap 864.836.3647)

Piedmont
Landsford Canal State Park – Offers teachers activities to use to guide their students investigations of the unique natural communities found in and near the rocky shoals of the Catawba River. Students will explore uniquely adapted plants and animals while investigating the geology and natural communities found in this area of the Catawba River. (Chester and Lancaster counties - 803.789.5800)

Sandhills
Sandhills State Forest – Located near Cheraw, this state forest showcases the wildlife communities that have developed on land that once were prehistoric sand dunes. Though the forest does not have structured education programs available, arrangements can be made for foresters to speak with school groups. The forest is open seven days a week. For more information call (843) 498-6478 or click on www.state.sc.us/forest.

Coastal Plain
Cypress Gardens – Cypress Gardens is a preserved blackwater swamp habitat located between Goose Creek and Moncks Corner. Trails, boats, a butterfly garden and freshwater aquariums can all be found here. The garden is opened seven days a week and offers environmental education programs for school groups. For more information call (843) 553-0515.

Coast
ACE Basin National Estuarine Research Reserve – This reserve, located between Edisto Beach and Hunting Island, contains 12,000 acres of tidal marshes and estuarine waters. The area is rich in wildlife: fish, crustaceans, birds and even mammals can all be found here. Boat tours are available through this area for high school and college students. For more information call (843) 762-5032.

Ocean
Huntington Beach State Park – With its marshes, maritime forest and beach, the educational focus of Huntington Beach will foster understanding of how natural communities are interdependent on each other and dependent on us. To protect our natural heritage, we must learn that we are part of, not apart from, the natural world. Through observation and hands-on activities, students gain an understanding of the importance of the resources found on this park and enhance their appreciation of environmental issues facing their own communities. (Georgetown County - 843.237.4440)