Classroom activity Grade 9 Health & Consumer Science

Reduce Lead at the Tap: A Grade 9 Home-Action Station Rotation

A grade 9 station rotation where students compare tap-lead readings, flush-water use, and filter costs to rank home actions against the lead action level.

Grade: Grade 9
Subject: Health & Consumer Science
Material: Classroom activity
Time: 45 min
Prep: Low prep
Materials: Printed station cards, Printed Student Handout, Calculators

Standards

HSN-Q.A.1 Common Core Math

Use units as a way to understand problems and to guide the solution of multi-step problems; choose and interpret units consistently in formulas; choose and interpret the scale and the origin in graphs and data displays.

How this material aligns: Students carry parts-per-billion readings, gallons of flush water, and dollars through the station computations, keeping each unit consistent as they judge lead-reduction actions.

All materials for HSN-Q.A.1 →

HSA-CED.A.1 Common Core Math

Create equations and inequalities in one variable and use them to solve problems. Include equations arising from linear and quadratic functions, and simple rational and exponential functions.

How this material aligns: At the filter station students create and solve a one-variable equation for total filter cost after a number of months, then evaluate it for a full year of use.

All materials for HSA-CED.A.1 →

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This material is in the public domain (CC0) and may be copied, edited, and shared freely, without attribution. Updated 2026-07-23.

Objectives

Students will compare tap-lead readings to the current and future lead action levels.
Students will rank three home actions for reducing lead by up-front cost and reliability.

Vocabulary

First-draw sample: A water sample taken from a faucet after the water has sat still in the pipes for hours, usually first thing in the morning. It shows how much lead can build up in water that sits in a home's pipes.
Service line: A service line is the small pipe that connects the water main under the street to the plumbing inside one home or building. It is the last leg of the trip water makes to your tap.

Also: lead action level, flushing

Teacher overview

Lead can enter tap water from old pipes and fixtures, and the amount often depends on how long water has been sitting still. This station rotation has small groups move through four stations that model a family's choices: reading a first-draw versus a flushed sample, counting the water a flush uses, pricing a certified filter, and comparing readings to the lead action level. The current action level is 15 ppb, and it drops to 10 ppb in 2027. The action level tells the utility when it must act; it is not a safe level, and EPA's health-based goal for lead is zero. Each station represents one real decision a household faces, and students record a number at each before ranking the actions in the debrief.

Activity Directions

Before class, set up four labeled stations with the printed cards, and give each student a Student Handout. The readings, prices, and flow rate on the cards are fictional figures chosen for this activity, built around the real 15 ppb action level.
Form groups of three or four and assign each group a starting station. Explain that a first-draw sample is water that sat in the pipes overnight, while a flushed sample is taken after running the tap.
Station 1 (Readings): groups record that the Hargrove first-draw sample is 21 ppb and the flushed sample is 6 ppb, then complete handout items 1, 2, 4, and 5.
Station 2 (Flush water): groups use the fictional 2.0 gallons-per-minute faucet to complete handout items 6 and 7 on how much water a flush uses.
Station 3 (Filter cost): groups use the fictional pitcher price to complete handout items 8 and 9, building the cost equation.
Station 4 (Percent of limit): groups complete handout item 3, comparing the first-draw reading to the action level.
Rotate groups every 5 minutes until each group has visited all four stations, then bring the class together.
Run the debrief with handout item 10: groups rank flushing, filtering, and service-line replacement by up-front cost and name which most reliably lowers lead at every tap. As a formative check, have each group state whether the flushed sample meets the current action level before dismissal.

Reduce Lead at the Tap: A Grade 9 Home-Action Station Rotation — Grade 9 Health & Consumer Science

Name: ____________________________ Date: ______________

Student Handout

Suppose the Hargrove household is checking its tap water for lead. The fictional first-draw sample tested at 21 ppb and the flushed sample at 6 ppb. The current lead action level is 15 ppb, dropping to 10 ppb in 2027. Show your work.

The first-draw sample is 21 ppb and the current action level is 15 ppb. How many ppb above the action level is the first-draw sample?
In 2027 the action level drops to 10 ppb. How many ppb above that stricter level is the 21 ppb first-draw sample?
What percent of the current 15 ppb action level is the 21 ppb first-draw reading? Round to the nearest whole percent.
Flushing the tap brought the reading down to 6 ppb. How many ppb did flushing remove from the 21 ppb first draw?
Is the flushed 6 ppb sample below the current 15 ppb action level, and by how many ppb?
The faucet flows at 2.0 gallons per minute. How many gallons run down the drain during a 30-second flush?
If the family flushes this way 4 times a day, how many gallons do they use flushing in one day?
A pitcher filter certified to reduce lead costs $40, plus $20 for each month's cartridge set. What is the total cost for the first month?
Write an equation for the total filter cost C, in dollars, after m months, then use it to find the cost after a full 12 months.
Rank three actions the Hargroves could take, flushing the tap, using a certified filter, and replacing the lead service line, from lowest to highest up-front cost, and name which one most reliably lowers lead at every tap.

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

Answer Key

The Hargrove readings and prices below are fictional figures built into the scenario.

Answer: 6 ppb. 21 ppb minus the 15 ppb action level equals 6 ppb above it.
Answer: 11 ppb. 21 ppb minus the future 10 ppb level equals 11 ppb above it.
Answer: 140 percent. 21 divided by 15 is 1.4, which is 140 percent of the current action level.
Answer: 15 ppb. The 21 ppb first draw minus the 6 ppb flushed sample equals 15 ppb removed by flushing.
Answer: Below, by 9 ppb. The flushed 6 ppb is under the 15 ppb level, and 15 minus 6 equals 9 ppb. Being below the action level does not make the water safe, because EPA's health-based goal for lead is zero.
Answer: 1.0 gallon. 2.0 gallons per minute times 0.5 minute (30 seconds) equals 1.0 gallon.
Answer: 4 gallons. 1.0 gallon per flush times 4 flushes equals 4 gallons in a day.
Answer: $60.00. The $40 pitcher plus $20 for the first month's cartridges equals $60.
Answer: $280.00. The equation is C = 40 + 20m; at m = 12, C = 40 + 240 = $280 for the year.
Answer: Lowest to highest up-front cost is flushing, then a certified filter, then service-line replacement; replacing the lead service line most reliably lowers lead at every tap because it removes the lead source rather than reducing exposure at one faucet.

Differentiation

Support

Provide a station card with the subtraction already set up as blanks (first draw minus level) so students plug in and compute. Give a filled example of the cost equation before Station 3.

Extension

Ask students to estimate a household's yearly flush-water use and compare it to the water a filter would let them avoid flushing, then argue whether flushing or filtering wastes less water over a year.

ELL supports

Pre-teach "first draw," "flush," and "action level" with a labeled drawing of a pipe holding still water overnight. Provide a sentence frame for item 10: "The most reliable action is ___ because it removes the ___ instead of only lowering lead at one tap."