Writing prompt Grade 8 Science
Emberpine Ridge Forest or a New Filter Plant for Ruddock
A grade 8 science argument writing prompt asking students to advise a fictional water board on buying watershed forest or building a filtration plant.
Objectives
- Students will state a claim recommending one of two watershed protection options to a water board.
- Students will support the claim with two reasons drawn from the background material and explain each.
- Students will acknowledge a counterclaim and answer it in a rebuttal paragraph.
Vocabulary
- Watershed
- A watershed is all the land where rain that falls will drain to the same stream, river, or lake. Everyone lives in a watershed, no matter how far from the water they live.
- Turbidity
- Turbidity is a measure of how cloudy or murky water looks because of tiny particles floating in it. Clear water has low turbidity, and muddy water has high turbidity.
- Filtration
- Filtration is the step where water passes through layers of sand, gravel, or other materials that trap the small particles still left in it. It works like a very fine strainer.
Also: ecosystem service, counterclaim, rebuttal
Teacher overview
A forested hillside above a reservoir does work that a treatment plant would otherwise have to do, because roots hold soil in place and leaf litter slows runoff before it can carry mud into the water. Communities with clean source water sometimes face a choice between buying and protecting that land or building the equipment that cleans up what the land no longer holds back. This prompt puts a fictional town at that decision point and asks students to write an argument essay to the water board. Both options are defensible, so the essay is scored on the quality of the reasoning rather than on which side the student picks.
Prompt
Background
Ruddock is a fictional town of about 9,000 people. Its drinking water comes from Sableridge Reservoir, which is filled by three streams draining Emberpine Ridge. The ridge is covered in forest. Because the streams run clear most of the year, Ruddock's small treatment plant has been able to meet its limits with settling and disinfection alone.
Two things changed this year.
First, the timber company that owns 4,000 acres on Emberpine Ridge offered to sell that land to the town for $6.2 million. If the town does not buy it, the company plans to log the slopes and sell house lots along the ridge road.
Second, the state told Ruddock that if turbidity in the reservoir rises, the town will need a full filtration plant. Turbidity measures how cloudy water is. Filtration plants must keep finished-water turbidity at or below 0.3 NTU in 95 percent of monthly samples and never above 1 NTU. A fictional engineering study estimates that a new plant for Ruddock would cost $14 million to build and about $400,000 each year to run.
The water board asked for advice from students in the town.
What the board knows about each option
Buying the forest: A forest floor soaks up rain and holds soil in place, so the streams stay clear after storms. The purchase is a one-time cost. The land would also stay open for the elk herd, the brook trout in the upper streams, and the hikers who use the ridge trail. A forest can still burn, and a fire followed by heavy rain can send a great deal of mud into a reservoir.
Building the plant: A filtration plant treats whatever water arrives, no matter what happens on the ridge. It gives the town a way to meet the turbidity limit even after a fire, a landslide, or new houses on the slopes. The plant costs more up front, costs money every year to operate, needs licensed operators, and does nothing for the elk, the trout, or the trail.
Your task
Write an argument essay to the Ruddock water board. Recommend either buying the Emberpine Ridge forest or building the filtration plant. State your claim clearly. Support it with two reasons, each backed by specific evidence from the background. Acknowledge the strongest argument for the other option and explain why your recommendation still holds. End with a short paragraph telling the board what would have to happen for you to change your mind.
Planning Organizer
Fill in every row before you begin drafting. Each row becomes at least one sentence in your essay.
| Part of the essay | What you write here |
|---|---|
| Claim | The one sentence naming which option the board should choose. |
| Reason 1 | The first reason your option is better. |
| Evidence for reason 1 | The detail from the background that supports reason 1. |
| Why that evidence matters | One sentence connecting the evidence back to your claim. |
| Reason 2 | The second reason your option is better. |
| Evidence for reason 2 | The detail from the background that supports reason 2. |
| Why that evidence matters | One sentence connecting the evidence back to your claim. |
| Counterclaim | The strongest argument someone would make for the other option. |
| Rebuttal | Your answer to that argument. |
| Change condition | What would have to happen for you to switch your recommendation. |
From Water for Schools (waterforschools.org). This material is in the public domain (CC0) and may be copied, edited, and shared freely.
Exemplar & Rubric
Exemplar response
The Ruddock water board should buy the 4,000 acres on Emberpine Ridge. Protecting the forest costs less over time than a filtration plant, and it keeps the reservoir clean instead of cleaning the water after it is already dirty.
My first reason is cost. The forest costs $6.2 million once. The filtration plant costs $14 million to build and about $400,000 every year after that. In ten years the plant would cost the town four million dollars in operating money alone, on top of the fourteen million it took to build. That evidence matters because the town has about 9,000 people, and every one of those dollars comes from water bills paid by families in Ruddock.
My second reason is that the forest prevents the problem instead of fixing it. A forest floor soaks up rain and holds soil in place, so the streams stay clear after storms. Ruddock's small plant has met its limits with settling and disinfection alone because the water arriving at the reservoir is already clean. If the slopes are logged and built on, mud will wash into Sableridge Reservoir, and the town will need the filtration plant anyway. Buying the land keeps the town out of that trap. It also keeps habitat for the elk herd and the brook trout, which a treatment plant does nothing to protect.
Someone on the other side would say that a filtration plant is the only sure answer. A forest can burn, and a fire followed by heavy rain can send a great deal of mud into a reservoir. A plant treats whatever water arrives and lets the town meet the limit of 0.3 NTU in any year. That is a real argument, and it is the strongest one against my claim. My answer is that owning the land is what gives the town the power to reduce that fire risk. A town that owns the ridge can thin the forest, keep the roads clear, and control who builds there. A town that does not own it has to accept whatever the next owner decides to do.
I would change my recommendation if the state ordered Ruddock to build a filtration plant regardless of how clear the water is. In that case the town would be paying for the plant no matter what, and spending $6.2 million on land as well would be more than a town of 9,000 people can carry.
Rubric
| Criterion | 1 Emerging | 2 Developing | 3 Proficient | 4 Advanced |
|---|---|---|---|---|
| Claim | Names an option without a clear recommendation. | States a recommendation in general terms. | States a clear claim naming the option and the main reason. | States a clear claim and previews both reasons that follow. |
| Evidence and reasoning | Gives no evidence from the background. | Gives one detail from the background without explaining it. | Gives specific evidence for both reasons and explains each one. | Gives specific evidence for both reasons, explains each, and compares the two options directly. |
| Counterclaim and rebuttal | No counterclaim appears. | Mentions the other option without stating its argument. | States the strongest opposing argument and answers it. | States the strongest opposing argument, answers it, and concedes the part that holds. |
| Organization and conventions | Ideas are hard to follow; errors block meaning. | Paragraphs are present but the order is unclear. | Clear paragraphs with transitions; errors do not block meaning. | Clear paragraphs, purposeful transitions, and a closing that names a change condition. |
Differentiation
Support
Give these students the organizer with the claim row already offering two sentence options to choose between, and with the counterclaim row filled in for whichever side they select. Allow them to write three paragraphs instead of five, combining the two reasons into one body paragraph.
Extension
Ask these students to write a second, shorter piece from the point of view of the timber company's manager, arguing for a third option in which the company sells only the steepest 1,200 acres nearest the streams and logs the rest. The piece must explain what that compromise protects and what it gives up.
ELL supports
Pre-teach "watershed," "turbidity," "counterclaim," and "rebuttal" with a labeled drawing of the ridge, the streams, and the reservoir. Provide sentence frames for each organizer row, such as "The board should ___ because ___," "The background says ___," and "Some people would argue ___, but ___." Allow students to draft the counterclaim paragraph orally with a partner before writing it.
Extensions
Students research whether any water utility in their own state owns land in its watershed, then write one paragraph comparing that utility's approach with the recommendation they made for Ruddock. Where no local example exists, students can instead compare their recommendation with a town that relies entirely on treatment, and describe what each town is buying with its money.