Billion Oyster Project

Add Pollution to Your Steward-Shed Model


Steward-shed Investigation



Class Periods




Subject Areas



Students take their research and observations from the field and synthesize them in order to experiment with how pollution moves through their steward-shed model.


  • Translate students’ research and observations into representation on a model.

  • Consider some of the benefits and shortcomings of using a model as a representation.

Materials and Resources


  • Materials that can represent pollution

    • Variety of colored powders or dyes (cocoa, fruit drinks, food coloring, etc.)

    • Glitter, sprinkles, cous-cous, rice krispies

    • Small pieces of plastic

    • Soil

    • Liquid soap

    • Oil

  • Any other reasonable materials mentioned by the students in the previous lesson (Steward-shed Investigation Part 4 - Pollution Based on Field Observations)

  • Spray bottle

  • water

Before you get started

Tips for Teachers

  • Consider having students bring in materials and supplies to represent the pollution instead of you doing it all.

Instruction Plan


  1. Students get into small groups.

  2. Each group gets their steward-shed model, all version of their Class Steward-shed Maps, and “Our Steward-shed” Library of Resources.

  3. Students review what types of pollution they are going to add to their model and how to represent it.

  4. Students discuss exactly how to put the materials on their model.  

    • Place them on top of the modeling clay?  

    • Push them into the clay?

    • Put them inside or on top of the built structures?


  1. Each group gets the “pollution” materials they need and spray bottle with water.

  2. Students carefully place materials on their model.

  3. Students predict: What will happen when we spray water on our model?  

  4. Students should start slow with spraying the water on their model and should observe the model closely after each couple of sprays.

  5. Students record their observations on one of their Class Steward-shed Maps.

  6. Students write:  based on these results, if we were to make another draft of this model, we would like to revise ______________________________________________________ because _________________________________________________________________.

  7. Consider whether you want students to clean off the pollution and do a second trial with different materials or different placement.

  8. Students share their results with the class.


  1. Ask your students the following series of questions:

    • Ask your students, What worked well about your model?  What worked well about using these materials?

    • What’s wrong with this model?  What doesn’t work so well about it?

    • What would you do differently if you were to do it again?

  2. If it hasn’t come up in discussion, point out that the model is an imperfect representation of what happens in the steward-shed.

  3. Ask your students:

    • How else (besides a 3D model) could we represent or record the pollution in our steward-shed?  

    • What kinds of representations would be most useful for explaining or showing the state of the steward-shed to people who have not studied it as extensively as we have?  (This could be the beginning of the discussion that leads into the stakeholders considered in Steward-shed Part 10 - Steward-shed Challenge)


NGSS - Cross-Cutting Concepts

  • Cause and Effect

    • Cause and effect relationships may be used to predict phenomena in natural or designed systems.
    • Cause and effect relationships may be used to predict phenomena in natural systems.
  • Influence of Engineering, Technology, and Science on Society and the Natural World

    • All human activity draws on natural resources and has both short and long-term consequences, positive as well as negative, for the health of people and the natural environment.
    • The uses of technologies and any limitation on their use are driven by individual or societal needs, desires, and values; by the findings of scientific research; and by differences in such factors as climate, natural resources, and economic conditions. Thus technology use varies from region to region and over time.
  • Scale, Proportion, and Quantity

    • Time, space, and energy phenomena can be observed at various scales using models to study systems that are too large or too small.
  • Science Addresses Questions About the Natural and Material World

    • Scientific knowledge can describe the consequences of actions but does not necessarily prescribe the decisions that society takes
  • Structure and Function

    • Complex and microscopic structures and systems can be visualized, modeled, and used to describe how their function depends on the relationships among its parts, therefore complex natural structures/systems can be analyzed to determine how they function.
    • Structures can be designed to serve particular functions by taking into account properties of different materials, and how materials can be shaped and used.
    • Structures can be designed to serve particular functions.
  • Systems and System Models

    • Models can be used to represent systems and their interactions.
    • Models can be used to represent systems and their interactions—such as inputs, processes and outputs—and energy and matter flows within systems.
    • Systems may interact with other systems; they may have sub-systems and be a part of larger complex systems.

NGSS - Disciplinary Core Ideas

  • ESS2.C: The Roles of Water in Earth's Surface Processes

    • Water continually cycles among land, ocean, and atmosphere via transpiration, evaporation, condensation and crystallization, and precipitation, as well as downhill flows on land.
    • Water’s movements—both on the land and underground—cause weathering and erosion, which change the land’s surface features and create underground formations.
  • ESS3.C: Human Impacts on Earth Systems

    • Human activities have significantly altered the biosphere, sometimes damaging or destroying natural habitats and causing the extinction of other species. But changes to Earth’s environments can have different impacts (negative and positive) for different living things.
  • ETS1.A: Defining and Delimiting Engineering Problems

    • The more precisely a design task’s criteria and constraints can be defined, the more likely it is that the designed solution will be successful. Specification of constraints includes consideration of scientific principles and other relevant knowledge that are likely to limit possible solutions.
  • ETS1.B: Developing Possible Solutions

    • A solution needs to be tested, and then modified on the basis of the test results, in order to improve it.
  • ETS1.C: Optimizing the Design Solution

    • Although one design may not perform the best across all tests, identifying the characteristics of the design that performed the best in each test can provide useful information for the redesign process - that is, some of the characteristics may be incorporated into the new design. (secondary)
    • Although one design may not perform the best across all tests, identifying the characteristics of the design that performed the best in each test can provide useful information for the redesign process—that is, some of those characteristics may be incorporated into the new design.
  • LS2.A: Interdependent Relationships in Ecosystems

    • Organisms, and populations of organisms, are dependent on their environmental interactions both with other living things and with nonliving factors.

NGSS - Science and Engineering Practices

  • Asking Questions and Defining Problems

    • Ask questions that can be investigated within the scope of the classroom, outdoor environment, and museums and other public facilities with available resources and, when appropriate, frame a hypothesis based on observations and scientific principles.
    • Define a design problem that can be solved through the development of an object, tool, process or system and includes multiple criteria and constraints, including scientific knowledge that may limit possible solutions.
  • Constructing Explanations and Designing Solutions

    • Undertake a design project, engaging in the design cycle, to construct and/or implement a solution that meets specific design criteria and constraints.
  • Developing and Using Models

    • Develop a model to describe unobservable mechanisms
    • Develop a model to generate data to test ideas about designed systems, including those representing inputs and outputs.
    • Develop a model to predict and/or describe phenomena
  • Obtaining, Evaluating, and Communicating Information

    • Gather, read, and synthesize information from multiple appropriate sources and assess the credibility, accuracy, and possible bias of each publication and methods used, and describe how they are supported or not supported by evidence.

NYC Science Scope & Sequence - Units

  • Grade 6, Unit 2

    • Weather and Atmosphere
  • Grade 6, Unit 4

    • Interdependence
  • Grade 7, Unit 1

    • Geology
  • Grade 8, Unit 4

    • Humans and the Environment: Needs and Tradeoffs