Worksheet Grade 9 Social Studies & Civics

Dividing the Ferncliffe Coatings PFAS Settlement Fund

A grade 9 worksheet in which students test three ways of splitting a fictional PFAS settlement among three water systems and decide who pays the remainder.

Grade: Grade 9
Subject: Social Studies & Civics
Material: Worksheet
Time: 55 min
Prep: No prep
Materials: Calculator

Standards

HSN-Q.A.2 Common Core Math

Define appropriate quantities for the purpose of descriptive modeling.

How this material aligns: Items 3 through 11 have students express the same fund as dollars per system, dollars per person served, and dollars per household, and item 14 asks which of those quantities best represents a fair split.

All materials for HSN-Q.A.2 →

D2.Eco.1.9-12 C3 Framework

Analyze how incentives influence choices that may result in policies with a range of costs and benefits for different groups.

How this material aligns: Items 12 through 14 ask students to show how each allocation rule shifts costs and benefits among three systems of very different size.

All materials for D2.Eco.1.9-12 →

D2.Civ.13.9-12 C3 Framework

Evaluate public policies in terms of intended and unintended outcomes, and related consequences.

How this material aligns: Item 15 asks students to evaluate a state response other than the split and to name the group that would carry its cost.

All materials for D2.Civ.13.9-12 →

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This material is in the public domain (CC0) and may be copied, edited, and shared freely, without attribution. Updated 2026-09-04.

Objectives

Students will calculate each system's share of a settlement fund under three different allocation rules.
Students will express an unfunded remainder as a cost per household.
Students will defend one allocation rule using a stated fairness standard.

Vocabulary

Maximum contaminant level (MCL): A maximum contaminant level, or MCL, is the highest amount of a certain substance that federal rules allow in drinking water. Water systems test regularly to prove their water stays under each limit.

Also: settlement, allocation, per capita, unfunded remainder

Teacher overview

When a company settles a contamination case, the money almost never covers the whole cost of the cleanup, so the rule for splitting it decides which communities finish the job and which ones send the rest of the bill to their own ratepayers. This worksheet uses a fictional settlement paid by a manufacturer called Ferncliffe Coatings and three fictional water systems of very different size. The misconception worth naming first is that an equal split is the neutral or automatic choice; students will find that equal shares, per-person shares, and cost-proportional shares each pick a different winner, and that the smallest system with the worst contamination is fully funded only by the equal split, which succeeds here because it ignores population entirely.

Dividing the Ferncliffe Coatings PFAS Settlement Fund — Grade 9 Social Studies & Civics

Name: ____________________________ Date: ______________

Student Worksheet

Ferncliffe Coatings, the three water systems below, and every figure in this worksheet are fictional, written for this exercise.

Ferncliffe Coatings used PFAS compounds at a plant above a shared aquifer for thirty years. Under a settlement with the state, the company will pay $18,000,000 into a fund for the three public water systems that draw from that aquifer. Each system has tested its wells and has an engineer's estimate for the treatment it needs.

For context, EPA set a maximum contaminant level of 4.0 parts per trillion each for PFOA and PFOS in April 2024, and water systems must comply by April 2029. In May 2026 EPA proposed letting eligible systems apply for a two-year exemption, to April 2031. The 4.0 parts per trillion limits would not change, and the proposal was not yet final as of September 2026, so the deadline is still in motion.

Water system	People served	Highest PFOA result (parts per trillion)	Estimated treatment cost
Ravensgill	24,000	22	$13,200,000
Stourbank	9,600	9	$6,000,000
Meltham	2,400	31	$4,800,000

The state board is weighing three allocation rules:

Method A: an equal share for each of the three systems.
Method B: an equal amount for each person served.
Method C: the same percentage of each system's own treatment cost.

Meltham serves 960 households. Any cost the fund does not cover must be raised from the system's own customers.

What is the total estimated treatment cost of the three systems combined?
The fund is $18,000,000. What percent of the total estimated treatment cost is that?
Under Method A, how much would each system receive?
Under Method B, how many people in all are served by the three systems?
Under Method B, how many dollars would the fund provide per person served?
Under Method B, how much would Ravensgill receive?
Under Method B, how much would Meltham receive?
Under Method C, each system receives the same percentage of its own treatment cost that you found in item 2. How much would Meltham receive?
Under Method B, how much of Meltham's treatment cost would be left unfunded?
Meltham serves 960 households. Under Method B, what is Meltham's unfunded amount per household?
Under Method C, what is Meltham's unfunded amount per household?
Meltham has the highest measured PFOA result of the three systems. Which method gives Meltham the largest share?
Explain why a per-person split leaves the most contaminated system with the least money. Use your answers to items 5 and 7 in your explanation.
Choose one of the three methods and defend it to the state board. Name the fairness standard you are applying, and say who would pay whatever your method leaves unfunded.
The fund covers only part of the total need no matter how it is split. Name one action the state could take other than changing the split, and name the group that would carry the cost of that action.

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

Answer Key

Answer: $24,000,000.
Add $13,200,000, $6,000,000, and $4,800,000.
Answer: 75 percent.
Divide $18,000,000 by $24,000,000 to get 0.75, then multiply by 100.
Answer: $6,000,000 per system.
Divide $18,000,000 by the three fictional systems.
Answer: 36,000 people.
Add 24,000, 9,600, and 2,400.
Answer: $500 per person.
Divide $18,000,000 by 36,000 people.
Answer: $12,000,000.
Multiply 24,000 people by $500 per person.
Answer: $1,200,000.
Multiply 2,400 people by $500 per person. As a check, the three Method B shares total $18,000,000.
Answer: $3,600,000.
Multiply Meltham's $4,800,000 treatment cost by 0.75.
Answer: $3,600,000.
Subtract the $1,200,000 Meltham would receive under Method B from its $4,800,000 treatment cost.
Answer: $3,750 per household.
Divide the $3,600,000 unfunded amount by 960 households.
Answer: $1,250 per household.
Meltham's Method C share is $3,600,000, which leaves $1,200,000 unfunded. Divide $1,200,000 by 960 households.
Answer: Method A.
Equal shares would give Meltham $6,000,000, more than its $4,800,000 treatment cost, while Method C gives it $3,600,000 and Method B gives it $1,200,000. Method A is the only rule that fully funds the fictional system with the worst contamination, and it does so because it ignores population entirely.
Answer: A per-person split pays $500 per person served, so the money follows population rather than contamination. Meltham serves only 2,400 people, so it receives $1,200,000 even though its wells tested highest and its treatment costs almost as much as Stourbank's. The cost of treating contamination in a small system is spread across few customers, which is what makes a per-person rule fall hardest there.
Answer: Accept any of the three methods when the student names a standard and identifies who pays the remainder. A strong Method A answer argues that every system faces the same fixed engineering costs for a treatment building regardless of size, and states that Ravensgill's ratepayers, being the most numerous, would absorb the remaining $7,200,000 at the lowest cost each. A strong Method C answer argues that proportional funding treats every ratepayer in the fictional region equally, and concedes that Meltham households would still owe $1,250 each. A strong Method B answer argues that public money should follow people, and must accept the $3,750 per Meltham household that follows from it.
Answer: Accept any defended action with the cost bearer named. Examples include a state grant or low-interest loan to close the gap, which taxpayers across the state would fund; requiring the three systems to consolidate so one treatment plant serves all of them, which would raise Ravensgill's rates and cost Meltham its own board; or suing Ferncliffe Coatings for the remainder, which risks years of delay and legal costs borne by the systems in the meantime.

Differentiation

Support

Provide a partly completed allocation table for the three fictional systems with the Method A column filled in, so students see the shape of the answer before computing Methods B and C. Give a worked per-person example using a different fund amount, and allow students to leave items 13 through 15 in bullet form.

Extension

Ask students to design a fourth method that blends population and contamination, state its rule in one sentence, compute all three shares under it, and show that the shares still total $18,000,000. Students then explain which of the fictional systems their method favors and why.

ELL supports

Pre-teach "settlement," "allocation," "per capita," and "unfunded" with a simple diagram showing one fund arrow splitting into three arrows of different widths. Provide sentence frames for items 13 and 14: "The per-person rule sends money to ___ rather than to ___," and "I chose Method ___ because fairness here means ___, and the remainder would be paid by ___."

Extensions

Students read the summary page their own state environmental agency publishes about PFAS in public water systems and note in one paragraph whether the state has a grant program for small systems, then compare that program to the fictional Meltham shortfall. A second option is to write the three-minute statement the fictional Meltham water board chair would deliver at the state board hearing, using the per-household figures from items 10 and 11.