Lesson plan Grade 9 Engineering & Design
Merrowfen Plant Upgrade: Splitting a Design Among Six Teams
A 50-minute grade 9 lesson where students break a fictional plant upgrade into six work packages, match each to the role that leads it, and write criteria for two.
Objectives
- Students will break a complex plant upgrade into work packages that can be designed separately.
- Students will match each work package to the role and preparation that leads it.
- Students will write one measurable criterion and one constraint for a named work package.
Vocabulary
Key words: work package, discipline, licensure, criterion, constraint
Teacher overview
The Merrowfen Water Reclamation District is a fictional utility that has won funding to upgrade a plant built in the 1970s. No single person designs a project like this, because the work spans process chemistry, electrical service, instrumentation, site grading, and the daily habits of the crew who will run it. This lesson has students take one upgrade, break it into six work packages, and decide which role leads each one, which is the decomposition step that engineering teams take before any design begins. It also gives students an accurate picture of how the people on that team got there, since the paths run from a high school diploma with on-the-job training and state licensure through certificates, four-year degrees, and graduate study, and the project needs all of them.
Procedure
Hook (5 min): Write on the board the sentence "Upgrade the Merrowfen plant," and ask students to name every separate job hiding inside it. Take answers for two minutes without sorting them, then explain that a design firm answers the same question in its first weeks on a project of this kind, and that its answer becomes the scope of work in the contract.
Direct instruction (12 min): Introduce the six work packages listed on the handout, one line each, and explain that a work package is a piece of the project with its own scope, its own budget, and one person responsible. Then introduce the roles the district will draw on: process engineer, electrical engineer, civil and site engineer, instrumentation and control technician, licensed plant operator, and laboratory analyst. Describe the preparation each role usually requires without ranking them. Note that becoming an operator typically takes a high school diploma, on-the-job training, and a state license earned by exam, with licenses issued in classes tied to plant size and experience, and that operators earned a median of $60,020 per year in May 2025 according to the Bureau of Labor Statistics. Note that engineering roles usually require a four-year degree and, for those who stamp drawings, a professional engineer license.
Guided practice (13 min): Distribute the handout. Work questions 1 and 2 with the class, and require students to say what evidence in the package description points to the role rather than guessing from the job title alone. Set up six labeled columns on chart paper and have pairs post a sticky note in the column where they placed each package, so disagreement is visible before the discussion.
Independent practice (15 min): Students complete questions 3 through 10 in pairs. Circulate and press pairs on question 6 to name a concrete cost of not splitting the work, such as one designer holding up five others. For questions 7 and 8, check that the criterion they write is measurable and that the constraint they name is a boundary rather than a goal.
Closure and formative check (5 min): Ask each pair to read only their answer to question 7 aloud. Mark on the board whether each criterion is measurable as written; if fewer than half are, open the next session by rewriting three of them together. Close by noting that about 10,000 openings for water and wastewater treatment plant and system operators are projected each year from 2025 to 2035, all from replacing workers who retire or move to other jobs, and that roughly one-third of the water workforce becomes retirement-eligible within the decade.
Student Handout
Suppose your team advises the fictional Merrowfen Water Reclamation District on how to organize its plant upgrade. The project has been split into six work packages.
Package A: Replace the headworks bar screen and grit chamber.
Package B: Add a third aeration basin with new blowers.
Package C: Replace the plant's electrical service and add a standby generator.
Package D: Install online sensors for dissolved oxygen and flow, tied into the plant's control system.
Package E: Regrade the site, rebuild the access road, and enlarge the stormwater pond.
Package F: Rewrite the plant's operating procedures and train the crew on the new equipment.
The roles available are: process engineer, electrical engineer, civil and site engineer, instrumentation and control technician, licensed plant operator, and laboratory analyst.
Which package is most likely led by an electrical engineer? Name the package letter.
Which package is most likely led by an instrumentation and control technician? Name the package letter.
Which package is most likely led by a civil and site engineer? Name the package letter.
Which role should lead Package F? Name the role.
Explain in one or two sentences why that role is the right lead for Package F.
Explain in two or three sentences why the district splits this upgrade into six packages instead of writing one design for the whole plant.
Write one measurable criterion for Package B, the third aeration basin. A measurable criterion states a number and a unit that someone could check after construction.
Name one constraint that applies to Package A, the headworks replacement, and explain in one sentence why it limits the design.
Describe the education and licensing path that a plant operator usually follows to reach the job.
About 10,000 openings for water and wastewater treatment plant and system operators are projected each year from 2025 to 2035, all from replacing workers who retire or move to other jobs. Name one step the district could take during this upgrade to prepare for that turnover, and give one sentence of reasoning.
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: Package C.
The electrical service and the standby generator are power distribution work, which is the electrical engineer's scope. Accept Package C only.Answer: Package D.
Online sensors tied into a control system are instrumentation work, which the instrumentation and control technician installs, calibrates, and integrates. Accept Package D only.Answer: Package E.
Grading, roads, and the stormwater pond are site civil work. Accept Package E only.Answer: The licensed plant operator.
Accept licensed plant operator, or operations supervisor if a student names the operator's supervisor. For the sticky-note columns, Packages A and B are both process work led by the process engineer; the laboratory analyst leads none of the six but supports startup testing on Package B.Answer: The operator runs the plant every day.
Accept any answer explaining that written procedures have to match how the plant is actually run, and that the operator is the person who knows the sequence of valves, alarms, and rounds well enough to write them correctly and to spot a procedure the crew cannot follow. Strong answers add that an outside designer would have to interview the operator anyway.Answer: Smaller pieces can be solved and checked separately.
Accept any answer making at least two of these points: each package has its own scope and budget so progress can be tracked; different packages need different expertise and licenses; packages can run in parallel rather than waiting on one designer; and a problem in one package does not stop the other five. Do not accept answers that only restate that the project is large.Answer: Any measurable aeration criterion.
Accept any statement with a number and a unit that could be verified after startup. Common correct answers include holding dissolved oxygen at or above 2.0 mg/L at the design load, treating a stated peak flow in MGD without exceeding permit limits, and keeping blower energy use below a stated figure in kilowatt-hours per day. Reject statements such as "the basin should work well" or "aeration must be efficient," which name no measurable quantity.Answer: Any genuine headworks constraint with a reason.
Accept any real boundary with an explanation attached. Common correct answers include that the plant cannot be taken offline, so the new screen must be built while the old one keeps running; that the new equipment must fit the existing channel width; that the channel invert elevation fixes how much head is available; that grit hauling needs truck access; and that odor control is required because homes sit nearby. Reject answers that name a performance goal, such as removing more grit, since that is a criterion.Answer: A high school diploma, on-the-job training, and a state license by exam.
Accept answers describing a high school diploma or equivalent, on-the-job training under experienced operators, and a state license earned by passing an exam, with licenses issued in classes tied to plant size and operator experience. Strong answers add that operators move up license classes as they gain hours and pass higher exams, and that some enter through a community college certificate or an associate degree in water technology.Answer: Any staffing step tied to the turnover.
Accept any concrete step with reasoning. Common correct answers include starting a paid apprenticeship or internship during construction, paying for exam preparation and license fees for current staff, recording the retiring operators' knowledge in the new written procedures from Package F, partnering with a nearby community college program, and scheduling overlap so a retiring operator trains a replacement before leaving.
Differentiation
Support
Give these students a matching page with the six package descriptions on the left and the six roles on the right, so questions 1 through 4 become a matching task. Tell them that one role leads two packages and one role leads none. Provide a worked example of a measurable criterion beside question 7, using a different package than the one asked about. Allow questions 5 and 6 to be answered in bullet points rather than sentences.
Extension
Ask students to build a simple sequence for the six packages, showing which must finish before others can start and explaining each dependency. Then have them identify the one package whose delay would stall the most other work in this fictional project, and write a short paragraph on what the district should do to protect that schedule.
ELL supports
Pre-teach work package, scope, license, and criterion with a labeled project chart showing six boxes, each with a role name beneath it. Provide the sentence frame "Package ___ belongs to the ___ because the work involves ___" for questions 1 through 4. Allow students to answer question 9 with a numbered list of steps rather than a paragraph.
Extensions
Have students research the licensing requirements for water and wastewater operators in their own state and compare the number of license classes, the required hours of experience, and the exam topics with what the lesson described. Ask them to present the comparison as a one-page chart and to note one requirement that surprised them. Students can then write a short paragraph explaining which package in the fictional Merrowfen upgrade would be hardest to staff locally and why.