administration student task rubric student work technical quality
Car Wash
Administration Procedures
Contributed by: Connecticut Academic Performance Test (CAPT)

In this activity you are going to investigate some of the chemical and physical effects of a car wash on its environment. Your performance on this activity, alone, and as a member of a group, will be assessed by your teacher, based on your written materials and your group's oral presentation. Therefore, make sure that everything you do is well documented. Keep a careful record of your experimental plans, all the data you gather, analyze and display (computation, graphing, etc.), and your final conclusions.

Your work will be scored by your teacher on the basis of the following four dimensions:

Part I- Getting Started by Yourself: Individual Understanding (Dimension I)

  1. The number and significance of the chemical and physical effects of a car wash in its immediate environment.
  2. Your ability to identify what scientific information you would need to help you locate the car wash.

Part II - Group Work: Group Experimentation (Dimension II)

  1. The number of significant environmental concerns.
  2. The number of significant site factors and environmental properties.
  3. Appropriate experimental design.
  4. Accurate performance of experiments.
  5. Accurate gathering, analyzing and reporting of experimental data.
  6. Decisions that are supported by the data.

Part III - Finishing by Yourself: Individual Understanding (Dimension I)

  1. Identification of the relevant factors affecting another environmental decision
  2. Ability to critique a sample research report and draw valid conclusions from it.

In addition, at the end of the Part II, every group member will be asked to complete the attached Collaboration Scoring Guide which contains criteria for Dimension III - Collaboration. The attached Oral Communication Scoring Guide contains criteria for oral presentations and will be used by you and your teacher during the group presentations to assess Dimension IV -- Oral Communication.

Part I: Getting Started by Yourself

An investor plans to open a car wash in your area. As the town's civil engineer it is your responsibility to recommend the most appropriate location for the new car wash operation.
  1. What are the most significant ways in which a car wash will chemically and physically affect the environment in the immediate area?

  2. What information regarding the proposed sites would you need to have before making your decision as to where to locate the car wash? (A map is provided that shows the location of the commercial sites, labeled A, B, and C. The sites are not served by a city water/sewer system.)

Part II: Group Work

  1. As a group, discuss and summarize your answers to the questions in Part 1.

  2. Among the factors that will affect your decision about the site are the physical and chemical properties of the soil types. Discuss and record the ideal physical and chemical soil properties required for the discharge of water from the car wash.

  3. Write out a complete experimental plan to test for these properties. (Soil samples from each site have been provided.) Show your plan to your teacher before proceeding.

    After getting approval from your teacher, carry out your experiments.

  4. Record all your procedures and results.

  5. Prepare a written report to the town council containing your recommendations. This should include the ranking of the sites from the most desirable to least desirable. Explain fully what you based your ranking on.

  6. Make an oral presentation to the town council (your class) summarizing the results of your study. Include graphical materials to aid your presentation. Each member of your group should be ready to participate in any part of the presentation.

Part III: Finishing by Yourself

  1. Your town recreation commission has notified the town's people that a community vegetable garden will be available in the spring. Based on what you have learned in this exercise, write a letter to the recreation commission describing all the factors that should be taken into consideration when choosing a site. Take into consideration the possibility that pesticides and fertilizers might be used in the community garden.

  2. The report on the next page was written by one group of students working on the Car Wash task. The report includes the study of permeability and the study of detergents. Read the report and answer the following questions.

    1. Permeability - is there enough information in the report to enable you to replicate (accurately repeat) it? If not, describe what is missing or not completely described in the report.

    2. Detergent - read the report and write comments about the validity of the conclusion.

Part III: Finishing by Yourself

Group Report
  1. Permeability Test

    1. Poke holes in the bottom of 3 paper cups.
    2. Put wet filter paper in bottom of cups.
    3. Put one soil sample in each cup.
    4. Place cups over glass jars.
    5. Pour water into each cup.

    Sample                 Time
    sand 6:55
    gravel 1:06
    silt 8:08

    Conclusion: water travels through gravel very quickly, through sand slowly, and through silt the slowest.

  2. Detergent Test

    1. Place 50 grams of sand into paper cup with holes in the bottom.
    2. Pour water and detergent mixture into cup containing sand.
    3. Collect liquid in beaker.
    4. Pour collected liquid into graduated cylinder and shake for 30 seconds.
    5. Measure height of suds formed.
    6. Pour detergent mixture through 50 grams of gravel in paper cup with holes.
    7. Repeat steps 3 - 5.
    8. Pour detergent mixture through 50 grams of silt in paper cup with holes.
    9. Repeat steps 3 - 5.

    Sample                 Amount of suds
    sand 15 ml
    gravel 14 ml
    silt 13 ml 10 ml

    Conclusion: Our data show that silt removes the most detergent from the water.


©1997-2005 SRI International. All rights reserved. Terms of Use