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Debate kit Grade 12 Social Studies & Civics

Should Bracklemoor Switch to Chloramine? A Council Debate

A two-session grade 12 debate kit on a fictional city's choice between converting to chloramine and treating for organic matter, with evidence on both sides.

Objectives

  1. Students will argue a public treatment decision using evidence from a shared file rather than from opinion.
  2. Students will rebut the strongest point on the other side rather than the easiest one.
  3. Students will name an unintended outcome of the position they defend.

Vocabulary

Corrosion control
Treatment that keeps water from slowly eating away at the inside of pipes. It helps stop metals like lead from getting into drinking water.
Granular activated carbon
Small black grains of specially treated carbon that grab contaminants as water flows through them. Utilities use big tanks of it to remove PFAS, bad tastes, and odors.

Also: chloramine, free chlorine, residual, disinfection byproducts, nitrification

Teacher overview

This kit runs as a two-team council debate with a three-member panel that votes at the end, using timed opening statements, a cross-question round, and closings. The question is genuinely contested in real utilities, because the cheaper fix changes the chemistry of every mile of pipe in town while the more expensive fix removes the material causing the problem in the first place. Session one is preparation from the evidence file, and session two is the debate and debrief. Teachers should expect the negative case to be as strong as the affirmative, since utilities that have converted and utilities that have declined to convert both had good reasons.

Should Bracklemoor Switch to Chloramine? A Council Debate — Grade 12 Social Studies & Civics
Name: ____________________________ Date: ______________

Resolution & Background

Resolution: The Bracklemoor City Council should direct Bracklemoor Water to switch the distribution system from free chlorine to chloramine.

The city of Bracklemoor is a fictional city of 46,000 people. Its plant treats water from the Coldfen River and sends it out through 190 miles of pipe. State law requires a disinfectant residual all the way to the last customer. Bracklemoor now uses free chlorine for that job.

Chlorine reacts with natural organic matter in river water and forms disinfection byproducts. More byproducts form the longer treated water sits in the pipes. In the past year, two of Bracklemoor's eight sampling sites were above the federal limit for those byproducts. Both sites are on long dead-end mains at the edge of town, where water can sit for days.

The utility has offered the council two ways to comply. The first is conversion to chloramine, made by adding ammonia to chlorine. Chloramine forms fewer of the regulated byproducts and holds a residual longer in the pipes. The second is adding granular activated carbon at the plant, which removes much of the organic matter before any disinfectant is added.

Roles. The affirmative team argues for conversion. The negative team argues against it and must name what the city should do instead. Three students serve as the council panel, ask one question of each team after the cross-question round, and vote at the end with a written reason. One student keeps time.

Format. Openings run four minutes per side. The cross-question round runs six minutes, alternating. Panel questions run four minutes. Closings run three minutes per side. The panel deliberates aloud for five minutes before voting.

Evidence File

Case for converting to chloramine

  1. The fictional Bracklemoor Water engineering memo projects that byproducts would fall below the federal limit at all eight sampling sites within one year of conversion, because chloramine forms far less of the regulated byproduct group than free chlorine does.
  2. State operator certification training materials describe chloramine as a slower-decaying secondary disinfectant than free chlorine, which is why it is used in systems with long pipe runs. Bracklemoor's two failing sites are on the longest dead-end mains in the fictional city.
  3. EPA rules set the maximum residual disinfectant level for chlorine at 4.0 mg/L, and systems typically hold 0.2 to 2.0 mg/L in distribution. Bracklemoor Water reports that it must dose near the top of its normal range to keep any residual at the far ends, which is also what drives byproduct formation there.
  4. The fictional utility estimates conversion at $900,000 to build, plus $140,000 a year for ammonia, added monitoring, and flushing. The carbon alternative is estimated at $14,000,000 to build, plus $600,000 a year. The council would have to raise rates for the second option.
  5. The fictional Bracklemoor Water complaint log shows most taste and odor complaints come from the same edge-of-town streets that fail the byproduct tests, where chlorine dose is highest.

Case against converting to chloramine

  1. Chloramine must be removed by dialysis clinics and by anyone keeping fish, and it cannot be removed by boiling or by letting water stand. The fictional Bracklemoor Kidney Care Center has written that it would need new carbon filtration and at least 90 days of notice before any change.
  2. State operator certification training materials warn that ammonia in the distribution system can feed nitrifying bacteria in warm, slow-moving water, which consumes the residual and raises nitrite. That risk is highest in dead-end mains, which are the same pipes the conversion is meant to fix.
  3. Changing disinfectant chemistry can disturb the scale inside old pipes and change how much lead dissolves into the water. In 2014 Flint, Michigan switched its water source without corrosion control treatment, which leached lead from pipes, and citizen science by residents, Dr. Mona Hanna-Attisha, and Virginia Tech researchers exposed the crisis. EPA's Lead and Copper Rule Improvements set the lead action level at 15 ppb, dropping to 10 ppb in 2027, and require replacing nearly all lead service lines within 10 years. Bracklemoor has not finished its service line inventory.
  4. Granular activated carbon removes the organic matter that causes the byproducts, so it fixes the cause rather than substituting a different disinfectant. The fictional engineering memo notes it would also reduce taste and odor complaints and give the plant a barrier against other contaminants in the Coldfen.
  5. A fictional ratepayer group, the Bracklemoor Water Users Alliance, argues that conversion moves a duty onto residents. Dialysis providers, hospitals, pet stores, and fish keepers would have to be notified and re-notified for years, and the city would carry that obligation permanently.

From Water for Schools (waterforschools.org). This material is in the public domain (CC0) and may be copied, edited, and shared freely.

Rubric

Each criterion is scored on four levels: Emerging, Developing, Proficient, and Advanced.

Criterion Emerging Developing Proficient Advanced
Use of evidence Claims are asserted without reference to the file. Two or more points are cited, but their sources are not distinguished as documented or fictional. Three or more points are cited accurately, and the speaker says which are utility estimates and which come from regulation or training materials. Evidence is weighed rather than listed, and the team explains why one point should count for more than another.
Rebuttal The other side's points go unanswered. The team answers the weakest opposing point only. The team answers the strongest opposing point directly and explains why its own case survives. The team anticipates the strongest opposing point in its opening and forces the other side to defend it.
Grasp of the trade-off The team treats the decision as obvious. The team acknowledges a cost but not who bears it. The team states what its position costs, who pays, and one unintended outcome it accepts. The team proposes a condition or safeguard that reduces its own position's weakness without conceding the resolution.
Delivery and organization Speeches run over or under time and have no visible structure. Time is kept, but points arrive in no clear order. Speeches are organized, within time, and each point is stated before it is supported. Delivery is clear and responsive, and the closing reframes the debate around the strongest ground for that side.

Differentiation

Support

Give these students an evidence file with the five points on their assigned side already sorted into "cost," "health," and "operations" categories, and provide a speaking outline with the first sentence of each section supplied. Allow two students to share one speaking role.

Extension

Require these students to argue the side they personally oppose, and to prepare a two-minute conditional position: what the fictional city of Bracklemoor should do if the council splits and neither option can pass this year.

ELL supports

Pre-teach "residual," "byproduct," "nitrification," and "corrosion" with a labeled cross-section of a pipe showing scale on the inside wall. Provide the frames "Our strongest evidence is ___, which shows ___." and "The other team says ___, but ___." Allow prepared speakers to read from a written script.

Extensions

Have students find how their own water system disinfects by reading the disinfection section of a published consumer confidence report, then write a paragraph explaining which side of the Bracklemoor debate their utility's practice supports. Students may also research how a utility notifies dialysis providers before a treatment change and compare that process with the notification duty described in the fictional Water Users Alliance statement.