Graphic organizer Grade 12 Health & Consumer Science
Comparing Household Water Treatment Options: A Grade 12 Organizer
A grade 12 organizer comparing no treatment, pitcher filters, reverse-osmosis systems, and whole-house filters on cost, upkeep, and contaminants addressed.
Objectives
- Students will compare four household water-treatment options on cost, maintenance, and the contaminants each addresses.
- Students will identify which household water-treatment option best fits a stated household scenario.
Vocabulary
- Point-of-use filter
- A small filter at a single faucet, like a pitcher filter or one that attaches to the tap. Certified filters can remove lead or PFAS from the water a family drinks.
- Reverse osmosis
- Reverse osmosis cleans water by pushing it through a membrane with holes so tiny that salt and most other dissolved things cannot fit through. It can even turn seawater into fresh water.
- Granular activated carbon
- Small black grains of specially treated carbon that grab contaminants as water flows through them. Utilities use big tanks of it to remove PFAS, bad tastes, and odors.
- Forever chemicals
- A nickname for PFAS, human-made chemicals that almost never break down in nature. Because they last so long, they can build up in water, soil, and people.
Teacher overview
As students prepare to manage their own households, deciding whether and how to treat tap water at home becomes a practical consumer decision. This organizer compares four common household approaches (no additional treatment, a pitcher or faucet activated-carbon filter, a reverse-osmosis under-sink system, and a whole-house point-of-entry filter) on the same set of criteria, so that students can weigh the options without assuming that more equipment always means safer water.
Organizer
| Criterion | No home treatment | Pitcher / faucet carbon filter | Reverse-osmosis under-sink system | Whole-house point-of-entry filter |
|---|---|---|---|---|
| Upfront cost | ||||
| Ongoing maintenance | ||||
| Contaminants it addresses well | ||||
| Contaminants it does not address well | ||||
| Water used or wasted during treatment | ||||
| Best-fit household scenario |
From Water for Schools (waterforschools.org). This material is in the public domain (CC0) and may be copied, edited, and shared freely.
Completed Exemplar
| Criterion | No home treatment | Pitcher / faucet carbon filter | Reverse-osmosis under-sink system | Whole-house point-of-entry filter |
|---|---|---|---|---|
| Upfront cost | None | Low | Moderate to high | Highest, usually with professional installation |
| Ongoing maintenance | None | Frequent cartridge replacement | Periodic membrane and pre-filter replacement | Professional service and larger filter-media replacement |
| Contaminants it addresses well | Whatever the public utility already removes before delivery | Chlorine taste and odor, some organic compounds, and lead if the model is certified to NSF/ANSI 53 for lead | Dissolved solids, nitrate, lead, arsenic, and many PFAS compounds | Sediment, chlorine taste and odor, and iron or manganese staining across every tap |
| Contaminants it does not address well | Anything specific to household plumbing, such as lead from old solder | Dissolved minerals, nitrate, and most short-chain PFAS compounds | Some volatile organic compounds pass through the membrane more easily than dissolved ions | Dissolved minerals or salts generally pass through unchanged |
| Water used or wasted during treatment | None | None | Rejects a portion of incoming water as wastewater during treatment | None for most standard filter-media configurations |
| Best-fit household scenario | A home on a public utility with no confirmed local contaminant concern | A household mainly concerned with chlorine taste, or with lead from plumbing if a certified model is chosen, on a limited budget | A household with a specific contaminant confirmed by a water test, able to afford the upfront cost and upkeep | A household wanting whole-house protection from sediment, staining, or taste and odor issues |
Differentiation
Support (below grade level)
Provide the "No home treatment" column already completed as a model, and allow students to complete the remaining columns using short phrases rather than full sentences.
Extension (above grade level)
Give students a short household scenario, such as a family whose water test confirmed elevated lead in a home built before lead solder was banned, and ask them to use at least three rows of the organizer to justify which treatment option best fits that household's situation and budget.
ELL supports
Pair each column header with a simple icon (a faucet, a pitcher, an under-sink cartridge, a whole-house tank), and allow every cell in the blank Organizer to be completed with single words or short phrases rather than full sentences.