NGSS · High School (9–12)

HS-ETS1-2 Break a complex problem into solvable engineering pieces

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

Why water teaches this standard well

A drinking water treatment train is a natural example of decomposition: coagulation, sedimentation, filtration, and disinfection each solve one piece of the larger problem of making water safe. Students can design a full treatment system stage by stage, exactly as process engineers do.

Materials tagged with this code are written to the full standard , and each carries a written note explaining the alignment. See how we review materials.

28 materials aligned to HS-ETS1-2

Lesson plans

Worksheets

Math problem sets

Classroom activities

Grade 9 Classroom activity

Wickhollow Main Break: A Valve Isolation Simulation

A 45-minute grade 9 activity where crews of students isolate a break on a fictional water main, count customers cut off, and size the flushing and disinfection work.

Science 45 min Answer key

Grade 10 Classroom activity

Hobbleton Ridge Percolation Stations: Sizing a Drainfield

A grade 10 station rotation sizing a soil absorption field for a fictional rural school, from a percolation test through trench layout, reserve area, and tank volume.

Engineering & Design 50 min Answer key

Grade 11 Classroom activity

Brellin Vale Control Room: An Alarm Triage Simulation

A grade 11 role-play in which shift teams triage eight simultaneous plant and distribution alarms, rank them by consequence, and state the first operator action.

Engineering & Design 45 min Answer key

Grade 11 Classroom activity

Halverstock Campus Cross-Connection Survey Rotation

A grade 11 station rotation where student inspectors survey six campus cross connections and select the minimum adequate backflow prevention assembly for each one.

Engineering & Design 50 min Answer key

Grade 12 Classroom activity

Harrowgill Service Line Inventory and Replacement Sprint

Grade 12 teams classify service line records at four stations, then size the crews, budget, and schedule a fictional district needs to replace lead lines.

Engineering & Design 55 min Answer key

Grade 12 Classroom activity

Pinderloe GAC Contactor Sizing Relay for PFAS Removal

Grade 12 teams pass one spec sheet through four desks, size carbon vessels for a fictional plant, find the contact time falls short, and redesign the bed depth.

Engineering & Design 60 min Answer key

Projects

Grade 11 Project

Ledgemont Wastewater Plant: A Phosphorus Removal Upgrade

A grade 11 engineering project where teams design a phosphorus removal upgrade for a fictional wastewater plant, sizing a chemical feed system within a budget.

Engineering & Design 5 sessions, ~275 min total Answer key

Grade 9 Project

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.

Engineering & Design 5 sessions, ~275 min total Answer key

Quizzes & test questions

Grade 11 Quiz & test questions

Vesper Flats Utility: A Grade 11 Water Engineering Unit Test

A grade 11 engineering assessment mixing multiple-choice, short-answer, and computation items on treatment-train design, detention time, chlorine dosing, and pressure.

Engineering & Design 40 min Answer key

Graphic organizers

Grade 10 Graphic organizer

Burnthorpe Dam Cause-and-Effect Chain: Retrofit or Remove

A grade 10 cause-effect chain organizer tracing six consequences of a fictional aging river dam and pairing each one with the engineering response it calls for.

Engineering & Design 45 min Answer key

Grade 11 Graphic organizer

Standish Creek Plant Upgrade: A Project Roles Organizer

A grade 11 phase-by-role organizer mapping who leads each stage of a water plant upgrade, what preparation each role takes, and which decisions are costly to reverse.

Engineering & Design 30 min Answer key