Worksheet Grade 11 Social Studies & Civics

Ravenshoe's Sewer Consent Decree: A Grade 11 Schedule Worksheet

Students compare two court-ordered sewer schedules for a fictional city, test each against a widely used affordability benchmark, and weigh marginal control costs.

Grade: Grade 11
Subject: Social Studies & Civics
Material: Worksheet
Time: 45 min
Prep: No prep
Materials: Calculator

Standards

D2.Civ.13.9-12 C3 Framework

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

How this material aligns: Items 12 through 14 evaluate the consent decree against its stated goal and trace an unintended outcome for lower-income households.

All materials for D2.Civ.13.9-12 →

D2.Eco.2.9-12 C3 Framework

Use marginal benefits and marginal costs to construct an argument for or against an approach or solution to an economic issue.

How this material aligns: Items 8 through 10 build a marginal cost argument about where overflow control should stop, using the two capital figures the worksheet supplies.

All materials for D2.Eco.2.9-12 →

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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 household bill burden as a share of income under two compliance schedules.
Students will use marginal cost reasoning to argue where a pollution control program should stop.
Students will explain the roles of the agency, the city, and the court in a consent decree.

Vocabulary

Combined sewer overflow: In some older cities, one pipe carries both sewage and rainwater. A combined sewer overflow happens when a big storm fills the pipe past what the plant can handle, and the extra mix spills into a river untreated.

Also: consent decree, capture rate, marginal cost, affordability burden

Teacher overview

Ravenshoe, a fictional city, has one set of pipes carrying both sewage and street runoff, so heavy rain pushes untreated overflow into the Padgett River. The federal government and the state have sued, and the city is negotiating a consent decree that fixes how fast the overflows must be controlled. Students price two schedules, test each against a widely used affordability benchmark, and then reason about where the control program should stop. The misconception to name in advance is that a consent decree is a punishment the court designs. The schedule is negotiated by the parties and then entered by a judge, which is why the city's own affordability analysis carries weight in the bargaining.

Ravenshoe's Sewer Consent Decree: A Grade 11 Schedule Worksheet — Grade 11 Social Studies & Civics

Name: ____________________________ Date: ______________

Student Worksheet

Background (fictional city, real benchmark). Ravenshoe's sewers carry both sewage and street runoff in one set of pipes, so heavy rain pushes untreated overflow into the Padgett River. EPA and the state have sued the city, and the three parties are negotiating a consent decree for a federal judge to enter. Ravenshoe has 31,000 households. The average combined water and sewer bill today is $79 a month. The city's median household income is $52,000 a year. In the city's lowest-income neighborhoods the median household income is $23,000 a year. A widely used rule of thumb, built by adding two EPA benchmarks, treats combined water and sewer costs above roughly 4.5 percent of household income as a high burden. EPA itself has no single official cutoff.

The two schedules (fictional). Option A finishes the overflow control work in 10 years and adds $36 a month to the average bill. Option B finishes in 18 years and adds $21 a month. Both options end at the same capture rate. Option B leaves overflows discharging to the Padgett River for eight more years.

Capital costs (fictional). Reaching a capture rate of 85 percent of overflow volume costs $96 million. Reaching 95 percent costs $186 million. The decree does not have to stop at either number.

The bill today is $79 a month and Option A adds $36 a month. What is the annual bill under Option A?
The bill today is $79 a month and Option B adds $21 a month. What is the annual bill under Option B?
Using your Option A annual bill and a median household income of $52,000, what share of income does the bill take? Give your answer as a percentage to one decimal place.
Using your Option B annual bill and a median household income of $52,000, what share of income does the bill take? Give your answer as a percentage to one decimal place.
Using your Option A annual bill and a neighborhood median income of $23,000, what share of income does the bill take? Give your answer as a percentage to one decimal place.
Using your Option B annual bill and a neighborhood median income of $23,000, what share of income does the bill take? Give your answer as a percentage to one decimal place.
The rule of thumb treats a burden above roughly 4.5 percent as high. Which option, if either, keeps the lowest-income neighborhoods below that benchmark?
Reaching 85 percent capture costs $96 million. What is the average capital cost for each percentage point of capture across that range? Round to the nearest hundredth of a million.
Moving from 85 percent capture to 95 percent capture raises capital cost from $96 million to $186 million. What is the cost of each additional percentage point in that range?
Compare your answers to items 8 and 9. Write two sentences arguing for a capture rate the decree should require, and name the cost your argument accepts.
Name the three parties involved in this consent decree and state what the judge actually does with the schedule the parties bring.
State the outcome the decree is designed to produce, and name the evidence in the background that shows the problem is real.
Name one unintended outcome of choosing Option A, and explain the chain of events that produces it.
Suppose Ravenshoe adds a bill discount program for households under a stated income. Explain how that changes your answer to item 7, and name one thing the program cannot fix.

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: $1,380 per year. The monthly bill becomes $79 plus $36, or $115, and $115 times 12 equals $1,380.
Answer: $1,200 per year. The monthly bill becomes $79 plus $21, or $100, and $100 times 12 equals $1,200.
Answer: 2.7 percent. $1,380 divided by $52,000 equals 0.0265, which is 2.65 percent, and rounds to 2.7 percent.
Answer: 2.3 percent. $1,200 divided by $52,000 equals 0.0231, which is 2.31 percent, and rounds to 2.3 percent.
Answer: 6.0 percent. $1,380 divided by $23,000 equals 0.06 exactly, which is 6.0 percent.
Answer: 5.2 percent. $1,200 divided by $23,000 equals 0.0522, which is 5.22 percent, and rounds to 5.2 percent.
Answer: Neither option. Both leave the lowest-income neighborhoods above the benchmark, at 6.0 percent under Option A and 5.2 percent under Option B, so a longer schedule alone does not solve the affordability problem.
Answer: $1.13 million per percentage point. $96 million divided by 85 percentage points equals $1.129 million, which rounds to $1.13 million.
Answer: $9 million per percentage point. The added cost is $186 million minus $96 million, or $90 million, spread over 10 percentage points.
Answer: A reasoned argument naming a capture rate and its cost. Strong responses note that each point above 85 percent costs roughly eight times what an average point below it costs, and then either stop near 85 percent and accept the remaining overflow, or go to 95 percent and accept the higher bills. Any answer must name the cost it accepts.
Answer: EPA, the state, and the city, with the judge entering and enforcing the decree. The parties negotiate the schedule; the judge reviews it, enters it as a court order, and holds the city to it, including through penalties if deadlines are missed.
Answer: Ending untreated overflows to the Padgett River. The background states that heavy rain pushes untreated overflow into the river from the combined system, which is the condition the decree is written to stop.
Answer: Households leaving service or falling behind on bills. The chain is that Option A raises bills quickly, the lowest-income neighborhoods reach a 6.0 percent burden, arrears and shutoffs rise, and collection costs and unpaid balances then push rates higher for everyone else. Accept any chain that names a mechanism.
Answer: The discount lowers the burden for enrolled households only. It can bring participating households below the benchmark, yet it cannot reach households that do not apply, and the discount is paid for by other ratepayers, so the total revenue the schedule requires does not change.

Differentiation

Support

Give students a completed first row of a burden table showing the monthly bill, the annual bill, the income, and the resulting percentage, then have them fill the remaining rows for items 1 through 6. Provide the division set up as a labeled fraction so the percentage step is visible.

Extension

Have students write the two-paragraph affordability section of the city's negotiating memo, recommending a schedule length and a discount program, and stating what the city offers the agencies in exchange for the longer schedule.

ELL supports

Pre-teach "consent decree," "overflow," "capture rate," and "burden" with a simple labeled diagram of a combined sewer in dry weather and in a storm. Provide the frame "Under Option ___, a household earning ___ pays ___ percent of its income, which is ___ the benchmark."