Driving Question
Big Ideas
Summary
Drinking water passes a variety of required tests. Students will put their own mystery sample solutions to a pH test to determine which one is the actual drinking water.
Engage
Can we trust our tap water?
Hold a brief class discussion. Capture students’ thoughts and ideas to come back to after this and the next learning activity.
Using the SLIDE DECK for Day 13
Introduce the concept of Regulation. Slides 2 and 3 prompt the students to talk about this concept.
Explore and Explain
Slide 5: Students begin to investigate how the local waterways have improved over the years due to regulations and advocacy. A number of sources are given as options. You can divide students into groups to investigate and share their findings. They will be analyzing data regarding changes in the fish populations. Another option is to ask elders in their families and communities what they remember about fishing in the Schuylkill River or local streams.
Slide 6: Students are given documents detailing laws that have been enacted to protect drinking water. Have students work in small groups to identify the key ideas from their assigned policy.
Ask students how the three laws work together to address gaps in the Clean Water Act.
Slides 7 and 8: Students are given a copy of the Drinking Water Quality Report which is issued to the public by the Philadelphia Water Department every year. Have students check out the data table at the bottom of the report and note some of the elements that are tested for that they may be familiar with: Lead, Copper, e-Coli, etc. Have them suggest some conclusions and questions.
Elaborate
Slide 9 provides links to other water quality reports from neighboring municipalities. Students are able to analyze the data and see how rigorous the testing is in Philadelphia compared to other municipalities. Ask students why they think that is so? What are some of the challenges faced by the Philadelphia Water Department that may not be faced in other communities?
Teacher Support
Driving Question:
How is clean and accessible drinking water in Philadelphia a civic responsibility?
Guiding Questions:
What does it take for us to drink a glass of fresh, clean, delicious water?
Students will be able to:
Accurately complete the chart and data analysis.
Use the data from the Water Mystery Data Sheet to determine the tap water sample.Use chemical tests in order to determine which solution is potable water.
Explain what the word ‘regulation’ means and what regulations we have in our daily lives.
Explore and Explain
5-in-1 test strips with color key
4 samples of liquids in plastic cups marked respectively
4 containers for each group of students
Tap water
Vinegar
Household bleach
Baking soda
Pencils
Safety goggles or glasses
Gloves
Testing the Waters Data Sheet (Attachment 2.5-A)
Preparation:
Create the following solution in the four mason jars (or beakers) before the lesson and label the samples as #1, #2, #3, and #4. Get or make extra copies of color keys so each group has a key.
Drinking water from tap
Acidic solution using tap water diluted with vinegar (950 mL water and 50 mL vinegar)
High chlorine solution using tap water diluted with household bleach (995 mL water and 5 mL bleach)
Hardness/alkalinity solution using tap water with baking soda (980 mL water and 60 g of baking soda)
BASIC WORDS:
Acid noun
Chemical substance that neutralizes alkalis, dissolves some metals and turns litmus red.
Base noun
A substance that, in aqueous solution, are slippery to the touch, reacts with acids and turns litmus blue.
Contaminant noun
a polluting or poisonous substance that makes something impure.
Contaminated adjective
Something (like water) that is impure as a result of an addition of poisonous or polluting substance
Chlorine noun
Chemical used for water purification and in the making of chlorine bleach.
pH noun
In chemistry, pH (power of hydrogen) is a measure of the acidity or basicity of an aqueous solution. Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline. Pure water has a pH very close to 7.
ADVANCED WORDS:
Alkalinity noun
Water’s buffering capacity to resist changes in pH that would make the water more acidic. (The pH of neutral water with zero alkalinity will immediately drop if a weak acid is added. The pH of water with higher alkalinity will change very little or not at all if a weak acid is added)
Chemistry noun
A science that deals with the composition, structure and properties of substances and with the transformations that they undergo.
Turbidity noun
In chemistry, turbidity is a measure of how clear the liquid is.
Accurately complete the chart and data analysis. Use the data from the Water Mystery Data Sheet to determine the tap water sample.
In their Watershed Journal, ask students to reflect on the key details in the content you have learned so far, and describe what you are still wondering about.
Make a determination as to which unknown sample solution (1, 2, 3, or 4) is acid (0-5), neutral (6-8), or alkaline (basic) (9-14 (pH)) by matching the known values with the values they received by testing.
Individually, each student writes up the testing procedure they undertook and explains their findings.
Reflection: Given the complexity that the Philadelphia Water Department is dealing with keeping up with the contaminants in our water supply, what three things will you recommend to your family and community that you and they need to do to prevent more and more contaminants from entering our water supply. Optional: Make a PSA.
PA STEELS
Environmental Literacy and Sustainability
3.4.9-12.C
Analyze and interpret how issues, trends, technologies, and policies impact watersheds and water resources.
3.4.9-12.D
Apply research and analytical skills to systematically investigate environmental issues ranging from local issues to
Student Materials
Student Worksheet