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Lesson plan Grade 10 Engineering & Design

Ferris Landing Lead Line Program: A Grade 10 Design Lesson

A 55-minute grade 10 lesson where students break a lead service line replacement program into stages and calculate the yearly pace and cost to meet a 10-year deadline.

Objectives

  1. Students will break a lead service line replacement program into its engineering stages and name the output of each.
  2. Students will calculate the yearly replacement pace and cost required to meet a 10-year deadline within a budget.

Vocabulary

Service line
A service line is the small pipe that connects the water main under the street to the plumbing inside one home or building. It is the last leg of the trip water makes to your tap.

Also: lead action level, replacement program, inventory, phasing

Teacher overview

EPA estimates that about 4 million lead service lines still connect US water mains to homes, and the federal Lead and Copper Rule Improvements now require water systems to replace nearly all of them within about 10 years while the lead action level drops from 15 ppb to 10 ppb in 2027. Replacing thousands of buried pipes is too big to tackle as one job, so engineers break it into stages that each produce a checkable output. In this lesson students study the fictional Ferris Landing Water Department, decompose its replacement program into stages, and then calculate the yearly pace and cost the program needs to finish on time and on budget. A common misconception this lesson addresses is that whether a program finishes on time depends mainly on how hard the crews work; the math shows how the yearly pace, the deadline, and the budget are linked, so a pace that sounds fast can still miss a fixed deadline.

Procedure

Hook (5 min): Ask students what would have to happen for their town to dig up and replace every lead pipe connecting the water main to a house. List the obstacles they name on the board, then explain that engineers manage a job this large by splitting it into stages, which is what the class will do next.

Direct instruction (12 min): Introduce the fictional Ferris Landing program and its four engineering stages, each with an output: (1) inventory, which produces a verified count and map of lead and unknown lines; (2) prioritization, which produces a ranked list, replacing lines at schools, daycares, and the highest test results first; (3) scheduling and construction, which produces a year-by-year replacement plan; and (4) verification, which produces post-replacement tap tests confirming lead levels have dropped. Connect the stages to the federal requirements: the action level drops to 10 ppb in 2027, and the rule calls for replacing nearly all lead lines within about 10 years.

Model a worked example (10 min): Using Ferris Landing's inventory of 1,500 lead lines and a 10-year deadline, model the pace calculation: 1,500 lines ÷ 10 years = 150 lines per year on average. Then show why a slower real pace matters. If crews replace only 120 lines in the first year, model 1,500 ÷ 120 = 12.5 years at that rate, which overshoots the 10-year deadline, so the program must speed up in later years.

Guided practice (13 min): In pairs, students work the tap-result case from the handout, in which a home tests at 12 ppb. They decide whether that result is above or below the new 10 ppb action level and by how much, then explain which program stage, prioritization, would move that home up the replacement list. Circulate and confirm pairs compare the result to 10 ppb, not the older 15 ppb.

Independent practice (10 min): Each student completes the Student Handout, calculating the yearly pace, the remaining count after year one, whether the year-one rate meets the deadline, the total program cost, and how many lines a yearly budget can fund.

Closure and exit ticket (5 min): Students write one sentence naming which program stage they think most affects whether Ferris Landing meets its 10-year replacement deadline, and why. Scan for answers that connect prioritization or scheduling to the deadline before dismissal.

Ferris Landing Lead Line Program: A Grade 10 Design Lesson — Grade 10 Engineering & Design
Name: ____________________________ Date: ______________

Student Handout

Ferris Landing Water Department is a fictional utility used for these problems. Its verified inventory lists 1,500 lead service lines that must be replaced within 10 years. Each replacement costs the department $9,000, and the department budgets $1,500,000 per year for the work.

  1. To finish all 1,500 lead lines within 10 years, how many lines must Ferris Landing replace per year on average?

  2. In year one, crews replace 120 lines. How many lead lines remain after year one?

  3. If the department kept the year-one pace of 120 lines per year, how many years would it take to replace all 1,500 lines, and would that meet the 10-year deadline?

  4. A home's tap tests at 12 ppb of lead. The action level drops to 10 ppb in 2027. Is that result above or below the 10 ppb level, and by how much?

  5. At $9,000 per line, what is the total cost to replace all 1,500 lead lines?

  6. With a yearly budget of $1,500,000 at $9,000 per line, how many whole lines can the department fund each year, and does that meet the average pace from question 1?

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: 150 lines per year.
    1,500 lines ÷ 10 years = 150 lines per year on average.

  2. Answer: 1,380 lines.
    1,500 − 120 = 1,380 lead lines remain after year one.

  3. Answer: 12.5 years.
    1,500 ÷ 120 = 12.5 years at the year-one pace, which is longer than the 10-year deadline, so that pace does not meet the deadline and the program must speed up.

  4. Answer: 2 ppb above.
    12 ppb − 10 ppb = 2 ppb, so the tap result sits 2 ppb above the new 10 ppb action level. The action level is judged on the 90th percentile of a system's tap samples, not on one home, and EPA's health goal for lead is zero, so a result below 10 ppb is not a safe level.

  5. Answer: $13,500,000.
    1,500 lines × $9,000 per line = $13,500,000 in total.

  6. Answer: 166 lines per year.
    $1,500,000 ÷ $9,000 = 166.7, so the budget funds 166 whole lines per year. Because 166 is more than the 150-per-year average from question 1, the budget is enough to hold the required pace.

Differentiation

Support (below grade level)

Provide the program-stage diagram with the four stages already labeled, and complete question 1 together so students see the total-divided-by-years pattern before they work the remaining questions. Allow a calculator for every step.

Extension (above grade level)

Ask students to find the steady yearly pace Ferris Landing would need for the remaining years if it replaced only 120 lines in each of the first two years, and to explain how a slow start forces a faster and more expensive finish to hold the same 10-year deadline.

ELL supports

Pre-teach service line, inventory, action level, and phasing with a labeled diagram and simple icons for each program stage. Provide a sentence frame for the exit ticket: "The ___ stage matters most because ___," and allow the handout calculations to be shown as numbered steps.