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Lesson plan Grade 12 Social Studies & Civics

Setting Cadderly County's Lead Action Level for Schools

A grade 12 lesson in which students sort a fictional school's lead results against two action levels, cost the remediation, and set a triage rule for a budget.

Objectives

  1. Students will sort sampling results against two candidate action levels and count the outlets each level captures.
  2. Students will calculate the remediation cost of a lead policy at one school and scale it to a district.
  3. Students will write and defend a triage rule for spending a fixed remediation budget.

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.

Also: outlet, remediation, triage, sampling, parts per billion

Teacher overview

The lead action level in federal drinking water rules is 15 ppb, falling to 10 ppb in 2027 under the Lead and Copper Rule Improvements, and it applies to a water system's sampling results across many homes rather than to any single tap. School districts testing their own fountains and sinks therefore have to choose a number of their own, and many pick something stricter than the system-wide figure because the water sits in the plumbing all weekend and because the people drinking it are children. This lesson puts students on the policy committee of the fictional Cadderly County school district as it picks that number and then finds out what the choice costs. The misconception to name early is that the federal action level is a health-based safety line for one faucet; it is a system-wide trigger for treatment and pipe replacement, which is why a district can adopt a lower screening number without contradicting the rule.

Procedure

Framing the problem (6 min): Present the fictional Cadderly County district's situation: state law now requires testing every drinking outlet in every school, and the board must adopt an action level and a remediation plan. Ask students to name, without calculating, who would want a stricter number and who would resist it.

Direct instruction (12 min): Distinguish the federal system-wide lead action level from a district's own screening level for a single outlet, and explain why the two answer different questions. Describe the three remedies used in the fictional district: replacing a fixture, installing a filtered bottle-filling station, and taking an outlet permanently out of service. Note that a filtered station costs more to install and also carries a filter replacement obligation the district must budget for every year.

Guided practice (10 min): Together, read the sampling table on the handout and mark which outlets sit at or above 15 ppb. Ask students to explain why the courtyard fountain at 5 ppb is counted under one candidate level and not the other.

Independent work (22 min): Students complete the handout. Watch for two common errors: counting outlets rather than pricing them by type, and multiplying by 9 schools before finishing the single-school total.

Closure (10 min): Ask three students to read their triage rules from item 10 aloud, then take a show of hands on which rule the class would adopt. Collect the handouts and check that at least three quarters of the triage rules name a defensible priority, such as highest result first or youngest students first, rather than simply listing every outlet.

Setting Cadderly County's Lead Action Level for Schools — Grade 12 Social Studies & Civics
Name: ____________________________ Date: ______________

Student Handout

The fictional Cadderly County school district tested all 12 drinking outlets at Vaneleigh Middle School. Results are in parts per billion, written ppb. The district can remedy a fountain by installing a filtered bottle-filling station for $2,400, or remedy a sink by replacing the fixture for $900. The district has 9 schools and assumes each one will cost about what Vaneleigh costs. This year's remediation budget is $48,000. The board is choosing between an action level of 15 ppb, which matches the federal system-wide lead action level, and a stricter district level of 5 ppb.

Outlet Type Result (ppb)
Cafeteria fountain A fountain 2
Cafeteria fountain B fountain 4
Gym fountain fountain 21
First-floor hall fountain fountain 7
Second-floor hall fountain fountain 12
Kitchen prep sink sink 1
Library fountain fountain 6
Locker room fountain fountain 33
Room 104 sink sink 3
Room 210 sink sink 16
Nurse's office sink sink 9
Courtyard fountain fountain 5
  1. How many of the 12 outlets tested at or above 15 ppb?
  2. How many of the 12 outlets tested at or above 5 ppb?
  3. Price the remediation of every outlet at or above 15 ppb at Vaneleigh, using $2,400 for each fountain and $900 for each sink.
  4. Price the remediation of every outlet at or above 5 ppb at Vaneleigh, using the same two prices.
  5. Estimate the cost for all 9 schools at the 15 ppb level by multiplying your answer to item 3 by 9.
  6. Estimate the cost for all 9 schools at the 5 ppb level by multiplying your answer to item 4 by 9.
  7. The budget is $48,000. How far short does it fall at the 15 ppb level?
  8. How far short does it fall at the 5 ppb level?
  9. Explain the difference between the federal lead action level, which applies to a water system's sampling results across many homes, and an action level a district adopts for a single school outlet.
  10. The board cannot fund the 5 ppb standard this year. Write a triage rule that decides which outlets are remedied first, and defend it in two or three sentences.

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: 3 outlets. In the fictional Vaneleigh results, the gym fountain at 21 ppb, the locker room fountain at 33 ppb, and the Room 210 sink at 16 ppb are at or above 15 ppb.
  2. Answer: 8 outlets. Adding the first-floor hall fountain at 7 ppb, the second-floor hall fountain at 12 ppb, the library fountain at 6 ppb, the courtyard fountain at 5 ppb, and the nurse's office sink at 9 ppb to the three from item 1 gives 8.
  3. Answer: $5,700. The three outlets are two fountains and one sink, so 2 times $2,400 is $4,800, plus $900, which totals $5,700.
  4. Answer: $16,200. The eight outlets are six fountains and two sinks, so 6 times $2,400 is $14,400, plus 2 times $900, which is $1,800, for a total of $16,200.
  5. Answer: $51,300. $5,700 times 9 schools equals $51,300.
  6. Answer: $145,800. $16,200 times 9 schools equals $145,800.
  7. Answer: $3,300 short. $51,300 minus the $48,000 budget leaves a shortfall of $3,300.
  8. Answer: $97,800 short. $145,800 minus $48,000 leaves a shortfall of $97,800.
  9. Answer: The federal action level is a system-wide trigger. A water system collects samples from many homes, and if the result at the ninetieth percentile exceeds the level, the system must act on corrosion control and lead service lines. A district's outlet level is a screening number applied to one faucet at a time, so it can be set lower without conflicting with the federal rule, and it decides which fixture gets fixed rather than what a utility must do.
  10. Answer: Answers vary; accept any rule that states a clear priority and defends it. Strong rules order the work by highest result first, by the age of the students served, or by whether an outlet is used for drinking rather than handwashing, and they say what happens to the outlets that must wait, such as taking them out of service until funding arrives. A rule that simply lists all eight outlets without a priority does not answer the item.

Differentiation

Support

Give students a sorting sheet with the fictional Vaneleigh results already listed in order from highest to lowest, so the counting in items 1 and 2 becomes a matter of drawing two lines. Provide a worked cost example using two fountains and one sink at a different fictional school before students attempt item 3.

Extension

Ask students to add a recurring cost to the analysis: each filtered station in the fictional district needs $180 of replacement filters every year. Have them recompute the ten-year cost of the 5 ppb policy for all 9 schools and explain how a recurring cost changes which remedy the board should prefer.

ELL supports

Pre-teach "outlet," "action level," "remediation," and "triage" with photographs of a fountain, a classroom sink, and a bottle-filling station. Allow students to answer items 9 and 10 with a labeled two-column comparison instead of paragraphs, and provide the frame "I would fix ___ first because ___."

Extensions

Have students draft the notification letter the fictional Cadderly County district would send to families after testing, stating what was found, what will be fixed this year, and what will wait. Require the letter to report the results plainly, to say which action level the board adopted and why, and to name the office a family can contact, then have classmates evaluate whether a reader would understand what was found without reading the table.