Classroom activity Grade 6 Health & Consumer Science
Reading a Water Quality Report: The Ridgeline Reservoir Station Relay
A grade 6 station-rotation activity where students compare four water-quality readings to real federal standards and calculate what percent of the readings passed.
Objectives
- Students will compare four water-quality readings to real federal drinking-water standards to judge pass or fail.
- Students will calculate what percent of a set of readings passed their standard.
Vocabulary
- Action level
- A trigger number in lead and copper testing. If too many homes test above this level, the utility must take steps like improving treatment and telling the public.
- 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.
Teacher overview
Every water utility in the United States publishes an annual report telling customers what was actually found in their water, and reading one is a practical consumer skill, similar to reading a nutrition label. This is a four-station rotation activity for small groups of 4 to 5 students. Each station represents one measurement from a fictional utility's report, and groups physically rotate through all four stations, using a real standards reference sheet to judge whether each reading passes or fails, the same comparison a water-quality professional makes every day.
Activity Directions
Before class, set up four stations around the room, each displaying one water-quality reading card from the (fictional) Ridgeline Water Utility's latest report (cards provided in the Student Handout). Give every group a Water Quality Standards Reference Sheet and a recording sheet.
Explain how the activity works: each station shows one real measurement type a utility must report, and at each station a group's job is to compare the reading on the card to the matching standard on the reference sheet and decide PASS or FAIL, writing one sentence explaining why.
Divide the class into groups of 4 to 5 students. Assign each group a starting station so all four stations are staffed at once.
Give groups 5 minutes at each station to read the card, find the matching standard on the reference sheet, record PASS or FAIL with a one-sentence reason, and discuss as a group before moving on.
Call time every 5 minutes and have groups rotate to the next station in order, until every group has visited all four stations.
The activity ends once every group has completed all four stations and recorded a judgment for each. Gather the class to reveal the correct answers together.
As a class, calculate what percent of Ridgeline's four readings passed. Close with the debrief question in the Answer Key.
Student Handout
Station cards (post one per station). All four readings come from a fictional utility's report created for this activity:
- Station 1 -- pH: The Ridgeline Water Utility's most recent report shows a pH reading of 7.4.
- Station 2 -- Lead: The Ridgeline Water Utility's most recent report shows a lead reading of 6 parts per billion (ppb).
- Station 3 -- Turbidity: The Ridgeline Water Utility's most recent report shows a turbidity reading of 1.3 NTU.
- Station 4 -- Chlorine residual: The Ridgeline Water Utility's most recent report shows a chlorine residual of 1.5 mg/L.
Water Quality Standards Reference Sheet (give one per group):
| Measurement | Standard |
|---|---|
| pH | Should fall between 6.5 and 8.5 |
| Lead | Action level is 15 ppb today, dropping to 10 ppb in 2027 |
| Turbidity | Finished water must never exceed 1 NTU |
| Chlorine residual | Maximum allowed is 4.0 mg/L, judged as a yearly average of many samples |
Recording sheet: For each station, write PASS or FAIL and one sentence explaining why, using the numbers from the station card and the reference sheet.
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: PASS (Station 1, pH 7.4). A reading of 7.4 falls within the recommended 6.5-8.5 range.
Answer: PASS (Station 2, Lead 6 ppb). A reading of 6 ppb is below both the current 15 ppb action level and the stricter 10 ppb level taking effect in 2027. Passing the action level does not make lead safe; EPA's health goal for lead is zero, so lower is always better.
Answer: FAIL (Station 3, Turbidity 1.3 NTU). A reading of 1.3 NTU exceeds the ceiling of 1 NTU that finished water must never exceed.
Answer: PASS (Station 4, Chlorine residual 1.5 mg/L). A reading of 1.5 mg/L is well below the 4.0 mg/L maximum allowed.
Answer: 75%. Class calculation: "What percent of Ridgeline's four readings passed?" Three of the four readings (pH, lead, and chlorine) passed, and 3 ÷ 4 = 0.75, or 75 percent.
Answer: Accept any answer describing retesting, checking the treatment process for a problem, and notifying the appropriate health agency and customers if the problem continues, since a single failing reading requires a utility to investigate and respond rather than ignore it. (Debrief question: "If a real utility got a failing turbidity reading like Station 3's, what should happen next?")
Differentiation
Support (below grade level)
Reduce the rotation to three stations instead of four, and provide the Water Quality Standards Reference Sheet with the relevant number for each measurement already highlighted.
Extension (above grade level)
Ask groups to write a second, invented station card of their own, using a number that would pass one of the four standards, and to trade cards with another group to check each other's work.
ELL supports
Pre-teach action level and turbidity with simple definitions and a labeled reference sheet that pairs each measurement's name with a simple icon (a droplet for pH, a warning triangle for lead, a cloudy glass for turbidity). Allow the recording sheet to be completed with the words PASS or FAIL plus a number, rather than a full sentence, where needed.