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Lesson plan Grade 6 Science

Pinewick's Lead Pipes: Building a Service Line Inventory

A 45-minute grade 6 science lesson where students use a fictional town's records to sort homes by lead-pipe risk and argue which service lines to replace first.

Objectives

  1. Students will explain why a lead service line is a risk mainly when corrosion control is missing.
  2. Students will sort homes by lead-pipe risk and argue with evidence which service lines to replace first.

Vocabulary

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.
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.
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.
Lead (Pb)
A soft gray metal that is poisonous, especially for children. It can get into drinking water from old pipes and plumbing, so utilities work hard to control it.

Also: inventory

Teacher overview

A service line is the short pipe that connects a home to the water main in the street. In older neighborhoods some of these lines are made of lead. A lead line can release lead into the water. Treatment plants add corrosion control that coats the inside of the pipe and reduces how much lead dissolves, and the danger rises sharply when that coating fails or is missing. EPA's health goal for lead is zero, so the action level is a trigger for action rather than a safe level. Before a town can replace its lead lines, it has to find them, and that record is called a service line inventory. This lesson uses the fictional town of Pinewick so students can build part of an inventory and argue which lines to replace first. Federal rules are in motion here, which the lesson presents as current and changing rather than settled.

Procedure

Hook (5 min): Show or describe three pieces of pipe, or photos: lead, copper, and plastic. If you show a real piece of lead pipe, keep it in a sealed bag and do not pass it around. Ask students which one they think is safe to carry drinking water, and collect a few guesses on the board without judging them yet.

Direct instruction (10 min): Explain the service line and corrosion control. Then give the moving pieces of the rule: the lead action level is 15 ppb today and is set to drop to 10 ppb in 2027, about 4 million lead service lines still remain across the country (EPA's 2025 estimate, built from the inventories utilities reported), and utilities must replace nearly all of theirs within about 10 years. Stress that a town must first find its lead lines, which is why an inventory comes before replacement.

Guided practice (12 min): As a class, read the records for Homes C, G, and H on the handout. Sort each into High, Medium, or Low replacement priority using three clues: the pipe material, how old the line is, and whether its last lead test came back above or below the action level. Model one claim aloud with its evidence from the pipe, age, and test columns.

Independent work (13 min): Students complete the handout: they sort the five homes in items 1 through 5 and then write a short claim-and-evidence paragraph naming the two homes Pinewick should replace first, citing the records.

Closure and exit ticket (5 min): Run a quick thumbs poll on one question: "Should a home with a lead line but a test below the action level still be replaced someday?" Then each student writes one sentence stating which home is the top priority and why. If more than a third of the class is unsure on the poll, revisit corrosion control before the next lesson.

Pinewick's Lead Pipes: Building a Service Line Inventory — Grade 6 Science
Name: ____________________________ Date: ______________

Student Handout

Pinewick is a fictional town updating its service line inventory. The table lists eight homes. "Last lead test" says whether the most recent test was above or below the action level; "not tested" means no sample has been taken yet.

Home Pipe material Line installed Last lead test
A Lead 1951 Above the action level
B Copper 1978 Below the action level
C Lead 1949 Below the action level
D Unknown 1955 Not tested
E Plastic 2015 Below the action level
F Lead 1962 Not tested
G Copper 1990 Below the action level
H Unknown 1958 Below the action level
  1. Sort Home A into High, Medium, or Low replacement priority, and give one reason from its record.
  2. Sort Home B into High, Medium, or Low priority, and give one reason.
  3. Sort Home D into High, Medium, or Low priority, and give one reason.
  4. Sort Home E into High, Medium, or Low priority, and give one reason.
  5. Sort Home F into High, Medium, or Low priority, and give one reason.
  6. Write a short paragraph: which two homes should Pinewick replace first? State a claim, then support it with evidence from the records.

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

Answer Key
  1. Answer: High priority. Home A has a lead line and its last test came back above the action level, so lead is already reaching the water and the line should be replaced first.
  2. Answer: Low priority. Home B has a copper line, not lead, and its last test was below the action level, so it carries little lead risk.
  3. Answer: High priority (or a strong Medium). Home D's material is unknown and the line is old, so it could be lead and has never been tested; it should be tested or replaced soon rather than assumed safe.
  4. Answer: Low priority. Home E has a new plastic line from 2015 and a test below the action level, so it has essentially no lead risk.
  5. Answer: High priority. Home F has a lead line and has never been tested, so it may already be releasing lead; an untested lead line should rank near the top.
  6. Answer: Accept any paragraph with a clear claim backed by record evidence. The strongest choice is Home A (a lead line testing above the action level) plus Home F or Home D (a lead or unknown line that has never been tested). Look for a stated claim and at least two pieces of evidence drawn from the material, age, or test columns.

Differentiation

Support

Give students a sorting key that lists the three clues in order and a simple rule for each, such as "lead line plus a failing or missing test equals High priority." Let them sort with the key first and add reasons afterward, and provide sentence starters for the paragraph.

Extension

Ask students to propose what Pinewick should do about the two "unknown" homes before spending money to dig, and to explain why testing or checking records first could save the town money compared with replacing every unknown line right away.

ELL supports

Pre-teach "service line," "corrosion control," and "action level" with a labeled picture of a house, a street main, and the pipe between them, one version coated and one bare. Provide a word bank of High, Medium, and Low, and allow students to give their reasons as short phrases or labeled sketches.