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Lesson plan Grade 10 English Language Arts

Havelock Ridge Switches to Chloramine: A Synthesis Lesson

A grade 10 ELA lesson in which students narrow a question about a fictional district's chloramine switch and synthesize three sources into one attributed paragraph.

Objectives

  1. Students will narrow a broad question into one a short set of sources can actually answer.
  2. Students will distinguish what each source is positioned to know from what it merely asserts.
  3. Students will write a synthesized paragraph that attributes each claim to its source.

Vocabulary

Key words: chloramine, disinfectant residual, synthesis, attribution, scope

Teacher overview

Utilities that change disinfectants have to explain the change to people whose needs differ sharply, and the resulting documents rarely agree in emphasis. This lesson hands students three short sources about one fictional district's switch from chlorine to chloramine and asks them to build a single accurate paragraph out of the three. The misconception this lesson targets is the belief that synthesis means listing what every source said. Students who hold that belief produce a paragraph in which a district notice, a clinic letter, and an operator memo carry equal weight on questions none of them share, so the procedure below forces students to decide first what each source is actually positioned to know.

Procedure

Opening question (5 min): Write a broad question on the board: "Is chloramine safe?" Ask students what a researcher would need in order to answer it. Collect responses without correcting them.

Direct instruction (10 min): Explain that a research question must be narrow enough for available sources to answer and wide enough to matter. Model narrowing the opening question in two steps, ending with a question about a specific decision by a specific utility for a specific group of people.

First reading (10 min): Students read the three sources on the handout and complete item 1, labeling what each source is in a position to know firsthand.

Guided practice (10 min): As a class, work item 2. Ask where the sources agree, where they disagree, and where they simply address different questions. Record the three categories in a chart on the board, since students routinely file "different question" cases under "disagreement."

Formative check (5 min): Each student writes one narrowed question on a slip and turns it in. Sort the slips into answerable and not-yet-answerable piles while students begin item 3. If fewer than two-thirds land in the answerable pile, pause and revise two examples with the class.

Independent writing (15 min): Students complete items 3 through 5, ending with the synthesized paragraph. Remind them that every claim needs an attributive phrase naming its source.

Closure (5 min): Two students read their paragraphs aloud. The class listens only for attribution and names any claim that arrived without a source.

Havelock Ridge Switches to Chloramine: A Synthesis Lesson — Grade 10 English Language Arts
Name: ____________________________ Date: ______________

Student Handout

The three sources below concern a fictional water district, Havelock Ridge, which is changing the disinfectant it adds to drinking water. Chlorine leaves the system quickly, while chloramine, made from chlorine and ammonia, holds a residual farther out in the pipes.

Source 1, a notice mailed by the Havelock Ridge Water District:

Beginning in April, Havelock Ridge will disinfect with chloramine instead of chlorine. The district serves about nine thousand connections through one hundred forty miles of pipe, and the far ends of the system have been difficult to keep protected. Chloramine holds its residual longer, so we expect fewer taste complaints and better protection in the outer zones. The district will keep a target residual of 1.0 mg/L at the ends of the system. Customers do not need to change how they drink, cook, or bathe. Two groups do need to take action: people on home dialysis and people who keep fish or amphibians.

Source 2, a letter from the Ridgeway Dialysis Center to its patients:

Our center has removed chloramine from dialysis water for many years, and our equipment already includes the carbon filtration required for this. You do not need to change anything you do at home for drinking or cooking. If you dialyze at home, call your equipment supplier before April and confirm in writing that your system is rated for chloramine. Do not rely on a filter pitcher or a refrigerator filter for this purpose. We will post the district's start date at the front desk as soon as it is confirmed.

Source 3, an internal memo from a Havelock Ridge operator to the district manager:

Two operational items should go in the public material. First, chloramine systems can develop nitrification in low-flow areas during warm months, which drives the residual down and can produce complaints that look like a different problem entirely. We will need a flushing schedule for the three dead-end zones before summer. Second, our aquarium retailers ask every year what to tell customers, and the dechlorinator that neutralizes chlorine does not necessarily neutralize chloramine. I recommend naming the product category in the mailer rather than sending people to a website.

  1. For each source, write one sentence naming what that source is positioned to know firsthand and one thing it is not positioned to know.
  2. Identify one point where two sources agree, one where they conflict, and one where they are simply answering different questions.
  3. Rewrite the broad question "Is chloramine safe?" as a narrowed question these three sources can answer together.
  4. Which source should a writer rely on for the claim that customers do not need to change how they cook? Explain why that source, and not one of the others, carries that claim.
  5. Write a synthesized paragraph of six to nine sentences answering your narrowed question. Draw on at least two sources, attribute every claim to the source it came from, and do not add information the sources do not contain.

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

Answer Key
  1. Answer: The district knows its own schedule, target residual, and system size, yet it is not positioned to know what any individual patient's home equipment requires. The clinic knows its own equipment and its patients' instructions, yet it is not positioned to know the district's start date. The operator knows the system's low-flow zones and past complaint patterns, yet is not positioned to know what retailers will stock.
  2. Answer: The district and the clinic agree that ordinary drinking and cooking require no change. They conflict on how firmly home dialysis patients can rely on the district's timing, since the clinic asks patients to confirm equipment in writing before April while the district only lists the group. Accept any defensible conflict, such as the district's claim of better protection in the outer zones set against the operator's warning that nitrification can drive the residual down in low-flow dead-end zones. They answer different questions on aquarium care, which only the operator memo addresses in any detail.
  3. Answer: Accept any question that names the district, the change, and a specific group or effect, such as: "What must Havelock Ridge customers on home dialysis or with home aquariums do before the April chloramine conversion?" Reject questions that no source can answer, such as questions about long-term health outcomes.
  4. Answer: The district notice, because the utility is the party that sets and knows the treatment change, and the clinic letter repeats rather than establishes that point. Accept an answer that names the clinic as a supporting source as long as the district is identified as the origin of the claim.
  5. Answer: Answers will vary. A proficient paragraph answers the student's own narrowed question, attributes each claim with a phrase such as "according to the district notice" or "the clinic letter instructs," draws on at least two sources, and adds nothing the sources do not contain. Deduct for unattributed claims and for sentences that merely summarize each source in turn without connecting them.

Differentiation

Support

Provide the three sources with the key sentences already underlined and a completed model of item 1 for Source 1. Reduce item 5 to five sentences and supply two attributive phrases students may reuse.

Extension

Ask students to identify the one question a reader would still have after reading all three sources, then draft the three interview questions they would ask the district manager to close that gap, explaining what kind of answer each question is designed to produce.

ELL supports

Pre-teach "disinfectant," "residual," "conversion," "dialysis," and "dead-end zone" with a simple diagram of a pipe network showing where residual is highest and lowest. Provide an attribution sentence bank: "According to ___, ___." and "The ___ states that ___." Allow item 1 to be completed as a two-column chart instead of full sentences.

Extensions

Have students revise the district's mailed notice using the operator's two recommendations, then write a short cover memo to the district manager explaining each change they made and which source justified it.