Worksheet Grade 12 Health & Consumer Science

Safe Formula Water in an Older Covendale Duplex: Lead Basics

A grade 12 health worksheet: a young family in a fictional older duplex reads its lead test, converts mg/L to ppb, and plans safe water for mixing infant formula.

Grade: Grade 12
Subject: Health & Consumer Science
Material: Worksheet
Time: 40 min
Prep: No prep
Materials: None

Standards

RST.11-12.7 Common Core ELA

Integrate and evaluate multiple sources of information presented in diverse formats and media (e.g., quantitative data, video, multimedia) in order to address a question or solve a problem.

How this material aligns: Items 9, 10, 12, and 13 require students to combine the four-sample lead table with the background text on standing time, hot water, and the action level to explain where the lead comes from and choose safe water for formula.

All materials for RST.11-12.7 →

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This material is in the public domain (CC0) and may be copied, edited, and shared freely, without attribution. Updated 2026-09-24.

Objectives

Students will convert lead results from milligrams per liter to parts per billion and compare them with the current and 2027 federal action levels.
Students will explain how standing time, hot water, and boiling change the amount of lead in water used for infant formula.
Students will choose a safe source of water for mixing formula and name a step a renting family can ask its landlord or utility to take.

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.
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.
Lead service line: A lead service line is an old water pipe made of lead metal that connects a house to the water main. Lead can get into the drinking water, so these pipes are being dug up and replaced across the country.
Corrosion control: Treatment that keeps water from slowly eating away at the inside of pipes. It helps stop metals like lead from getting into drinking water.

Also: parts per billion, certified filter

Teacher overview

Some twelfth graders already care for infants as older siblings, babysitters, or young parents, and many will soon set up a first household in older rental housing. This worksheet follows a fictional young couple, Nia and Tomas Rosales, who rent half of an older duplex in the fictional town of Covendale and have a newborn who drinks formula. They receive a lead test report in milligrams per liter, while public guidance uses parts per billion, so students convert units, compare results with the federal action level of 15 ppb and the 10 ppb level that takes effect in 2027, and then turn the numbers into decisions about formula water.

Two misconceptions are addressed directly. The first is that boiling water removes lead; boiling drives off water and leaves the lead behind, so it makes the problem worse. The second is that a result below the action level means the water is safe for a baby. The action level is a regulatory trigger for the utility, not a health threshold, and health agencies state that no safe level of lead has been found for children.

Safe Formula Water in an Older Covendale Duplex: Lead Basics — Grade 12 Health & Consumer Science

Name: ____________________________ Date: ______________

Student Worksheet

The situation. Nia and Tomas Rosales rent the upstairs half of an older duplex in the fictional town of Covendale. Their daughter is three weeks old and drinks formula mixed with water. The fictional Covendale Water Utility lists the duplex's service line, the pipe that runs from the water main to the building, as "material unknown." The family ordered a test from a certified lab. Here are the results.

Sample	How it was collected	Lead result
A	Kitchen cold tap, first water out after sitting overnight	0.021 mg/L
B	Kitchen cold tap, after running the water for 5 minutes	0.004 mg/L
C	Bathroom sink cold tap, first water out after sitting overnight	0.012 mg/L
D	Kitchen hot tap, first water out after sitting overnight	0.027 mg/L

Background. Health agencies say that no safe level of lead has been found for children. Lead can harm a child's developing brain and nervous system, and the harm may not show up until later. A baby who drinks formula takes in far more water for its body size than an adult does. Lead usually gets into tap water from the plumbing, not from the treatment plant. It comes from lead service lines, lead solder, and older brass faucets and fittings. Lead dissolves faster when water sits still in the pipes and when the water is hot. Boiling does not remove lead. Because water boils away and the lead stays behind, boiling makes lead more concentrated.

Under federal rules, the lead action level is 15 ppb, and it drops to 10 ppb in 2027. An action level is a trigger for the utility, not a health limit. If too many homes in a water system test above it, the utility must take steps such as treating its water to make it less corrosive and teaching the public about lead. The same rules require utilities to replace nearly all lead service lines within 10 years.

Unit note. In fresh water such as tap water, 1 mg/L is about equal to 1 part per million (ppm), and 1 ppm equals 1,000 parts per billion (ppb). To change mg/L to ppb, multiply by 1,000.

Using the background, explain why lead in tap water is a special concern for a baby who drinks formula.
Where does lead in tap water usually come from? Explain using the background.
Convert Sample A, 0.021 mg/L, to parts per billion.
Convert Sample B, 0.004 mg/L, to parts per billion.
Convert Sample C, 0.012 mg/L, to parts per billion.
Convert Sample D, 0.027 mg/L, to parts per billion.
Sample A is 21 ppb. By how many ppb does it exceed the current action level of 15 ppb?
Sample C is 12 ppb. By how many ppb does it exceed the 10 ppb action level that takes effect in 2027?
Samples A and B came from the same kitchen tap. What does the drop from Sample A to Sample B tell the family about where the lead is coming from and when it is highest?
Sample D, from the hot tap, had the most lead of all four samples. Explain why formula should always be made with cold water.
Tomas suggests boiling tap water for five minutes to "boil the lead out." Explain why this will not work.
Sample B is below both action levels. Explain why the family should still not treat Sample B as safe for the baby's formula.
The family is choosing among three sources of formula water: (a) bottled water, (b) cold tap water passed through a filter certified to remove lead, and (c) cold tap water run for 5 minutes each morning. Which choice or choices are best for the baby right now? Explain.
The Rosales family rents the duplex. Name one step they can ask their landlord or the Covendale Water Utility to take, and explain why it would help.

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: No safe level of lead has been found for children, lead can harm a baby's developing brain and nervous system, and a formula-fed baby drinks far more water for its body size than an adult.
Accept answers that give the brain or nervous system harm together with the large amount of water a baby takes in for its size.
Answer: From the plumbing: lead service lines, lead solder, and older brass faucets and fittings.
The background states that lead usually gets into tap water from the pipes and fixtures rather than from the treatment plant.
Answer: 21 ppb.
0.021 mg/L times 1,000 equals 21 ppb. Check: 21 divided by 1,000 equals 0.021.
Answer: 4 ppb.
0.004 mg/L times 1,000 equals 4 ppb. Check: 4 divided by 1,000 equals 0.004.
Answer: 12 ppb.
0.012 mg/L times 1,000 equals 12 ppb. Check: 12 divided by 1,000 equals 0.012.
Answer: 27 ppb.
0.027 mg/L times 1,000 equals 27 ppb. Check: 27 divided by 1,000 equals 0.027.
Answer: 6 ppb.
21 ppb minus 15 ppb equals 6 ppb above the current action level.
Answer: 2 ppb.
12 ppb minus 10 ppb equals 2 ppb above the level that takes effect in 2027.
Answer: The lead is coming from the plumbing near the tap or the service line, and it is highest after water has sat still in the pipes.
Running the water for 5 minutes brought in fresher water from the main, and the result fell from 21 ppb to 4 ppb. Accept any answer that links the higher first-draw result to standing time in the building's pipes.
Answer: Hot water dissolves more lead from pipes and fittings, as Sample D shows, so cold water should be used and heated on the stove if needed.
Accept answers that cite Sample D's result of 27 ppb as the highest of the four.
Answer: Boiling does not remove lead; it drives off water and leaves the lead behind, so the water that remains has more lead in it.
Accept any answer that says boiling concentrates lead rather than removing it.
Answer: The action level is a trigger for the utility, not a health limit, and no safe level of lead has been found for children, so even a small amount matters for a baby who drinks a lot of water for its size.
Accept answers that separate the regulatory trigger from health safety.
Answer: Choice (a) or (b), bottled water or cold tap water through a filter certified to remove lead.
Running the tap lowered the lead but did not remove it, since Sample B still had 4 ppb, so choice (c) is not the best option for a newborn's formula. Accept either (a) or (b), or both, with a reason.
Answer: Accept any reasonable step, such as asking the utility to identify the service line material and schedule its replacement, or asking the landlord to replace old brass faucets and fittings.
Strong answers note that the utility must replace nearly all lead service lines within 10 years under the federal rules, so the family can ask where their building falls in that schedule. Also accept asking the landlord to install a certified filter at the kitchen sink.

Differentiation

Support

Work item 3 together as a class, writing the unit note as a two-step chain on the board: mg/L to ppm, then ppm to ppb. Give students a four-row conversion table to fill in for items 3 through 6 before they answer the comparison items. Allow items 9 through 12 to be answered in one or two sentences each.

Extension

Ask students to write a short, plain-language text message that a public health nurse could send to a family like the Rosales family after a fictional lead test. The message must fit in about 60 words, include one step for today and one step for this month, and avoid any technical term the family would not know.

ELL supports

Pre-teach "lead," "formula," "sample," "boil," "filter," and "landlord" with a labeled picture of a kitchen sink, a pipe running to the street, and a baby bottle. Provide the sentence frames "Sample ___ was highest because ___." and "The family should use ___ because ___." Allow students to answer items 1 and 2 by labeling the picture.

Extensions

Have students look up whether their own water utility has published a service line inventory or map, as utilities are now required to do, and find how a resident can learn the material of the service line at a specific address. Students can write two sentences describing how a renter would use that tool.