Graphic organizer Grade 11 Engineering & Design

Three Source Waters for Cardimore: A Treatment Selection Frame

A grade 11 three-column organizer comparing a river, a reservoir, and a sandstone aquifer across nine design criteria, with a completed exemplar for teachers.

Grade: Grade 11
Subject: Engineering & Design
Material: Graphic organizer
Time: 30 min
Prep: No prep
Materials: None

Standards

HS-ETS1-1 NGSS

Analyze a major global challenge to specify qualitative and quantitative criteria and constraints for solutions that account for societal needs and wants.

How this material aligns: Each organizer row converts one source characteristic into a measurable criterion or constraint that a treatment plant must satisfy, the criteria-and-constraints work this standard requires.

All materials for HS-ETS1-1 →

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: The quantity-constraint and design-risk rows require students to weigh seasonal water quality, supply reliability, and treatment burden against one another before recommending a source, which is the prioritized evaluation 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 2026-09-03.

Objectives

Students will translate raw water characteristics into required treatment barriers.
Students will compare three candidate sources across nine design criteria.
Students will justify a source recommendation using seasonal risk rather than average water quality.

Vocabulary

Raw water: Raw water is water taken from a river, lake, or well before it has been treated. It may look clean, but it is not ready to drink yet.

Also: treatment barrier, natural organic matter, stratification, hardness

Teacher overview

This organizer is a three-column comparison frame in which each row states one design criterion and each column holds one candidate source for a small town's new water supply. Students fill the frame from a short source-water description, then use the completed columns to recommend a source and the treatment barriers it demands. The structure keeps the comparison honest, because a source that looks best on an annual average can be the hardest to treat during the two weeks of the year that actually govern plant design. The misconception the frame is built to surface is the widespread belief that groundwater is inherently clean and therefore the cheap choice; a sandstone well often arrives with hardness, iron, and manganese that require their own treatment train, and the drawdown limit on a wellfield can cap the town's growth year-round, while a river's limit applies mainly during late-summer low flow.

Three Source Waters for Cardimore: A Treatment Selection Frame — Grade 11 Engineering & Design

Name: ____________________________ Date: ______________

Organizer

The fictional town of Cardimore is choosing among three candidate sources for a new plant. Fill in each cell from the source descriptions below, giving units wherever a cell holds a measurement. All figures in this scenario are hypothetical.

The Verrow River: Turbidity is near 4 NTU in dry weather and rises past 300 NTU within hours of a storm. Water temperature runs from about 1 to 26 degrees Celsius over the year. Organic matter is high and climbs after storms and in warm months. Hardness is moderate, iron is low, and manganese rises slightly after storms. Occasional tastes and odors follow rain and are tied to upstream discharges. The river is open to runoff and wildlife, and the withdrawal permit caps how much the town may take during late-summer low flow.
Cardimore Reservoir: Turbidity holds steady between 2 and 6 NTU and changes little after storms. In summer the surface layer is warm and the deep water is cold, and the water column mixes in autumn. Organic matter is moderate most of the year and rises sharply during algal blooms each August and September, when the water develops earthy tastes and odors. Hardness is moderate, and the oxygen-poor bottom layer releases manganese in late summer. The supply is limited by how much water storage can carry through a dry year.
The Corham sandstone aquifer: Turbidity stays below 1 NTU all year, and water temperature stays near 12 degrees Celsius. Organic matter is low. Hardness is near 240 mg/L as calcium carbonate and iron is near 1.6 mg/L in every sample, and the iron stains fixtures. Testing has not yet shown whether the wells are influenced by surface water. The amount the town can pump is limited by well yield and by how much drawdown the aquifer will tolerate.

Design criterion	The Verrow River	Cardimore Reservoir	The Corham sandstone aquifer
Typical raw turbidity and how fast it changes
Temperature range across the year
Natural organic matter and disinfection byproduct risk
Pathogen barriers the source demands
Hardness, iron, and manganese
Seasonal taste-and-odor risk
Treatment barriers this source indicates
Quantity constraint on how much the town can take
Largest design risk if this source is chosen

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

Completed Exemplar

All values below describe the fictional Cardimore sources and are hypothetical figures written for this organizer. The finished-water turbidity target of 0.3 NTU applies to both surface-water columns, since the rule sets it for filtration plants treating surface water; it would apply to the aquifer only if the wells were found to be under the direct influence of surface water.

Design criterion	The Verrow River	Cardimore Reservoir	The Corham sandstone aquifer
Typical raw turbidity and how fast it changes	Near 4 NTU in dry weather, rising past 300 NTU within hours of a storm	Steady between 2 and 6 NTU, with little storm response	Below 1 NTU and nearly constant all year
Temperature range across the year	Roughly 1 to 26 degrees Celsius, which changes coagulation chemistry seasonally	Surface layer warm in summer, cold at depth, with the water column mixing in autumn	Steady near 12 degrees Celsius, so chemistry is stable year round
Natural organic matter and disinfection byproduct risk	High and variable, so byproduct formation rises after storms and in warm months	Moderate, rising sharply during late-summer algal blooms	Low, so byproduct formation is the least of the three
Pathogen barriers the source demands	Filtration and disinfection, since the source is open to runoff and wildlife	Filtration and disinfection, since the reservoir is also surface water	Disinfection may be sufficient if the wells are shown not to be influenced by surface water
Hardness, iron, and manganese	Moderate hardness, low iron, manganese rising slightly after storms	Moderate hardness, with manganese released from the anoxic bottom layer in late summer	Hardness near 240 mg/L as calcium carbonate and iron near 1.6 mg/L in every sample
Seasonal taste-and-odor risk	Occasional, tied to upstream discharges after rain	Predictable each August and September when blooms produce earthy compounds	None from algae, though iron causes staining complaints
Treatment barriers this source indicates	Coagulation, flocculation, sedimentation, filtration, and disinfection, with dose control able to track fast turbidity swings	The same barriers plus a seasonal powdered activated carbon feed and an intake that can draw from several depths	Oxidation and filtration for iron and manganese, disinfection, and optional softening
Quantity constraint on how much the town can take	Limited during late-summer low flow, when the withdrawal permit caps the take	Limited by storage volume carried through a dry year	Limited by well yield and by the drawdown the aquifer will tolerate
Largest design risk if this source is chosen	A storm turbidity spike outrunning coagulant dose control and pushing filtered water above the turbidity target	A bloom season that arrives earlier or lasts longer than the carbon feed was sized for	A wellfield that cannot grow with the town, plus steady customer complaints about hardness

Differentiation

Support

Give these students the first two rows completed for all three fictional columns as a worked model, and reduce the frame to six rows by removing the quantity constraint, the taste-and-odor, and the design-risk rows. Provide a word bank containing coagulation, sedimentation, filtration, disinfection, oxidation, softening, and activated carbon so the treatment-barrier row can be built from named parts.

Extension

Ask these students to add a tenth row for the energy each source would require per unit of water delivered, filling it qualitatively, and to explain why a plant on the fictional aquifer may still cost more to run than one on the fictional river. Then have them write a one-paragraph recommendation naming the source they would choose and the single criterion that decided it.

ELL supports

Pair each row label with a simple icon: a cloud and raindrop for turbidity, a thermometer for temperature, a leaf for organic matter, a shield for pathogen barriers, a faucet with a white ring for hardness, and a nose for taste and odor. Allow cells to be completed with short phrases rather than sentences, and provide the frame "The fictional river needs ___ because its water ___."

Extensions

Have students locate the annual water quality report published by their own utility and identify which of the three fictional source types it most resembles, then mark which rows of the organizer the report lets them fill with real local values. A second step is to ask what the report does not tell them, since most reports publish annual averages rather than the storm-day and bloom-season values that actually drive plant design. Students can then write a short list of questions they would ask a plant operator to fill the remaining cells.