Project Grade 9 Engineering & Design

Juniper Bend Treatment Train Design Challenge

A grade 9 engineering project where teams design a four-stage drinking water treatment train for a fictional town within a flow, footprint, and budget.

Grade: Grade 9
Subject: Engineering & Design
Material: Project
Time: 5 sessions, ~275 min total
Prep: Moderate prep
Materials: Grid paper for site layouts, Rulers, Calculators, Teacher-provided process reference sheet, Teacher-prepared equipment price sheet, Poster paper or slides for the final pitch

Standards

HS-ETS1-2 NGSS

Design a solution to a complex real-world problem by breaking it down into smaller, more manageable problems that can be solved through engineering.

How this material aligns: Teams break the problem of making river water safe into four solvable stages, coagulation, sedimentation, filtration, and disinfection, the decomposition of a complex problem this standard requires.

All materials for HS-ETS1-2 →

HS-ETS1-3 NGSS

Evaluate a solution to a complex real-world problem based on prioritized criteria and trade-offs that account for a range of constraints, including cost, safety, reliability, and aesthetics as well as possible social, cultural, and environmental impacts.

How this material aligns: In the final proposal teams evaluate their design against prioritized criteria and trade-offs, including turbidity, footprint, and budget, exactly the constraint-weighing this standard describes.

All materials for HS-ETS1-3 →

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This material is in the public domain (CC0) and may be copied, edited, and shared freely, without attribution. Updated 2026-07-17.

Objectives

Students will design a four-stage drinking water treatment train that meets a turbidity target.
Students will size treatment steps and fit the design within a stated footprint and budget.

Vocabulary

Coagulation: Coagulation is the first cleaning step at a drinking water plant. Operators quickly mix in a chemical that makes tiny bits of dirt stop pushing each other away so they can start sticking together.
Sedimentation: Sedimentation is the step where water sits almost still in a big basin so the heavy clumps of dirt can sink to the bottom. The cleaner water on top then moves on to the filters.
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.
Disinfection: Disinfection is the step that kills or disables germs in water so it is safe to drink. Water plants usually disinfect with chlorine, ultraviolet light, or ozone.
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.

Also: treatment train, footprint

Teacher overview

Juniper Bend is a fictional town that plans to draw drinking water from a muddy river. Raw river water is too cloudy to drink, so it must pass through a series of treatment steps. Over five sessions, teams design that series, called a treatment train, and size each step to the town's needs. The driving question is how to bring cloudy river water down to a safe, clear standard within a fixed footprint and budget. Each team pitches its design to a fictional water board.

Juniper Bend Treatment Train Design Challenge — Grade 9 Engineering & Design

Name: ____________________________ Date: ______________

Project Brief

Driving question: How can a team design a treatment train that makes muddy river water safe for Juniper Bend's 8,000 residents, within a set footprint and budget?

Scenario: The Juniper Bend Water Board has asked student engineering teams to design a new treatment plant. The source is a river that runs cloudy after rain. The board wants a clear plan it can understand and afford.

Constraints (all set for this fictional project):

Design flow: 1.5 MGD.
Site footprint: no more than 20,000 square feet.
Capital budget: $4.5 million for the major process equipment.
Finished water must meet the drinking water turbidity target of 0.3 NTU in 95 percent of samples.
The plant must leave a chlorine residual in the range of 0.2 to 2.0 mg/L.

Required stages: The train must include four stages. These are coagulation and flocculation, sedimentation, filtration, and disinfection. Each stage solves one part of the larger problem.

Final deliverable: Each team turns in two items. The first is a labeled process flow diagram drawn to scale on grid paper. The second is a one-page written proposal to the Water Board. The proposal must show how the design meets the turbidity, footprint, and budget limits.

Milestones

Session 1 (criteria and stages): Teams list the criteria and constraints in their own words. They then draw a block diagram naming the four stages in order. Output: a criteria sheet and a labeled block diagram.
Session 2 (size the basin and filters): Teams size the sedimentation basin for 3 hours of detention at the 1.5 MGD flow, which comes to about 187,500 gallons, or near 25,000 cubic feet. They then size the filters for a loading rate of 4 gpm per square foot, which needs about 260 square feet of filter area. Output: a sizing calculation sheet.
Session 3 (disinfection, layout, and cost): Teams pick a chlorine dose of 2.0 mg/L and find the feed in pounds per day. They lay out all four stages on grid paper within the 20,000-square-foot site. They estimate costs against the $4.5 million budget using the teacher price sheet. Output: a scaled site layout and an itemized cost estimate.
Session 4 (diagram and proposal): Teams draw the final process flow diagram. They write the one-page proposal to the Water Board. The proposal explains how each constraint is met. Output: a draft diagram and a draft proposal.
Session 5 (pitch and revise): Teams present their design to a panel acting as the Water Board. They answer one question from the panel. They then revise one part of the design. Output: the final diagram, proposal, and a short presentation.

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

Rubric

Criterion	Emerging	Developing	Proficient	Advanced
Treatment train completeness	One or more of the four stages is missing	All four stages are named but the order or purpose is unclear	All four stages appear in the correct order with each purpose stated	All four stages are in order, each purpose is stated, and the team explains how the stages work together
Sizing and turbidity target	Sizing is missing or unrelated to the flow	Sizing is attempted but with unit or method errors	Basin and filters are sized correctly for the 1.5 MGD flow and the design aims at the 0.3 NTU target	Sizing is correct, the design meets the 0.3 NTU target, and the team explains the margin it leaves
Footprint and budget	The design ignores the footprint or budget	The design names the limits but exceeds one of them	The design fits within 20,000 square feet and the $4.5 million budget with an itemized list	The design fits both limits, is itemized, and the team explains one trade-off it made to stay within them
Proposal and pitch	The proposal is incomplete or hard to follow	The proposal covers the design but omits some reasoning	The proposal clearly shows how each constraint is met	The proposal is clear, meets every constraint, and anticipates a likely Water Board question

Differentiation

Support

Give these teams the sedimentation basin volume and filter area already worked out, so they can focus on the layout, cost, and proposal. Provide a simplified price sheet with fewer equipment choices, and a block-diagram template that lists the four stages in order.

Extension

Ask teams to add a fifth criterion of their own, such as energy use or ease of operation, and to explain how it would change their layout or cost. Have them compute what filter area the design would need if the loading rate were lowered to 3 gpm per square foot, and describe the footprint trade-off that change creates.

ELL supports

Provide a labeled reference sheet showing each treatment stage with a simple icon and a one-line description. Allow the written proposal to use short labeled sketches beside brief sentences rather than full paragraphs, and provide sentence frames for the pitch.