Debate kit Grade 9 Social Studies & Civics
Should Graymont Recycle Wastewater into Drinking Water? A Debate Kit
A grade 9 debate kit on whether a fictional city should recycle its wastewater into drinking water, with two-sided evidence on cost, safety, and drought.
Objectives
- Students will evaluate two-sided evidence on a water-reuse policy resolution.
- Students will construct and deliver a rebuttal supported by named evidence.
- Students will apply marginal cost reasoning to a water-supply choice.
Vocabulary
- Indirect potable reuse
- Recycling water into drinking water with a natural stop along the way. Highly cleaned water is put into the ground or a reservoir, then drawn back out later and treated again for drinking.
- Drought
- A long stretch of drier-than-normal weather that leaves too little water for people, farms, and nature. Droughts build slowly and can last for years.
- Ratepayer
- A person or business that pays a utility bill. Ratepayers provide most of the money that keeps a water system running.
Also: advanced treatment, marginal cost
Teacher overview
This is a two-team structured debate for a 60-minute block, with a second session available for prep and rebuttals. Students argue for or against a city building advanced treatment to recycle its own wastewater into drinking water, a practice called indirect potable reuse. The resolution is genuinely contested: reuse can create a drought-proof local supply, yet it is expensive, faces public doubt, and competes with cheaper options. Assign an affirmative team, a negative team, and, if the class is large, a panel of judges who score using the rubric.
Resolution & Background
Resolution: "The city of Graymont should build an advanced water purification facility to recycle its treated wastewater into drinking water, even though doing so will raise water rates."
Background: The fictional city of Graymont depends on a single river. That river runs low in dry years. To secure its supply, the council is weighing indirect potable reuse. In this approach, the city treats its wastewater again through advanced steps, including reverse osmosis. It then returns the water to a groundwater basin or reservoir. Later, the city draws it back out for drinking water. Reuse recycles water the city already has. It does not import more or draw down the river.
Reuse is proven at scale. Orange County's system in California is the world's largest indirect potable reuse plant. It produces 130 million gallons of water per day. Reuse also competes with other choices. A coastal city might build a desalination plant instead. The nation's largest, in Carlsbad, California, makes about 50 million gallons per day. That is roughly 10% of San Diego County's supply. Seawater desalination uses about 11 to 15 kilowatt-hours of energy per 1,000 gallons. Conventional treatment uses only about 1 to 2 kilowatt-hours. Reuse cleans water that is far less salty than seawater. So it usually uses less energy than seawater desalination, though more than treating a fresh river.
Evidence File
Case for building the reuse facility:
- Reuse creates a local, drought-proof supply. It recycles water the city already produces. So it does not dry up the way a river can in a dry year. (Reasoning drawn from the background.)
- Reuse works at large scale. Orange County's system produces 130 million gallons per day. That shows a major city can rely on reuse for much of its water. (Source: Orange County Water District.)
- Reuse uses less energy than seawater desalination. Desalination needs about 11 to 15 kilowatt-hours per 1,000 gallons. Reuse treats far less salty water, so it can secure supply at a lower energy cost. (Source: industry energy references.)
- A fictional Graymont engineering study for this debate estimates reuse could meet much of the city's summer demand. It would also cut the city's reliance on the shrinking river. (Illustrative estimate created for this debate, not a documented figure.)
Case against building the reuse facility:
- Public trust is a real barrier. Some residents distrust drinking water that began as wastewater, even when it meets every safety standard. That doubt can slow or block a project. (Reasoning.)
- Advanced treatment is costly to build and operate. Those costs raise water rates for every household. A fictional Graymont ratepayers' group argues the city should not add that burden now. (Illustrative testimony created for this debate.)
- Reuse does not create new water. It only recycles existing wastewater flows. If residents conserve and send less water down the drain, the plant has less to recycle. Its yield is capped by how much wastewater the city produces. (Reasoning.)
- Cheaper options should come first. Conservation and leak repair usually cost less per gallon than a new plant. The council should try those lower-cost steps before it commits to reuse. (Marginal cost reasoning. Even a large single project like Carlsbad's desalination supplies only about 10% of a large county, so no single project solves everything.)
From Water for Schools (waterforschools.org). This material is in the public domain (CC0) and may be copied, edited, and shared freely.
Rubric
| Criterion | Emerging | Developing | Proficient | Advanced |
|---|---|---|---|---|
| Evidence use | Repeats a claim with no cited evidence | Cites one piece of evidence without explaining its relevance | Cites at least two pieces of evidence and explains how each supports the team's position | Cites multiple pieces of evidence, explains their relevance, and anticipates the other side's likely response |
| Rebuttal quality | Does not respond to the opposing team's points | Responds to an opposing point but without new evidence | Directly rebuts a specific opposing point using evidence from the file | Rebuts multiple opposing points and explains why the team's evidence outweighs them |
| Organization & delivery | Argument is hard to follow with no clear structure | Argument has a structure but transitions are unclear | Argument follows a clear claim, evidence, and conclusion structure | Argument is clearly structured, confidently delivered, and directly responsive to the resolution |
Differentiation
Support
Provide each side a single evidence card listing its strongest point in plain language, and give rebuttal sentence starters ("Our opponents claim ___, but the evidence shows ___."). Allow students to read rebuttals from written notes.
Extension
Ask students to work out, using only the Evidence File, how a phased plan might address the "cheaper options first" objection, for example by starting with conservation and adding reuse later, and to build that plan into a stronger closing argument.
ELL supports
Pre-teach "indirect potable reuse," "advanced treatment," "marginal cost," and "ratepayer" with a simple diagram tracing water from drain, through treatment, to a reservoir, and back to the tap. Allow students to deliver arguments from written notes rather than from memory.