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Classroom activity Grade 5 Science

Palmerton's Purple Pipe Sort: Matching Water to Its Job

Teams rotate through four stations sorting twelve water-use cards into drinking-water and recycled-water bins, then total the gallons a reuse system could serve.

Objectives

  1. Students will decide which everyday water uses need drinking-quality water and which can use recycled water.
  2. Students will total the daily gallons a recycled water system could supply in one town.
  3. Students will explain why a town builds a second set of pipes for recycled water.

Vocabulary

Recycled water
Wastewater that has been cleaned and used again, often to water parks, golf courses, and crops instead of being thrown away. Purple pipes usually carry it.
Purple pipe
The purple-colored pipes that carry recycled water for watering lawns and other non-drinking uses. The color warns everyone that the water inside is not for drinking.

Also: reclaimed water, drinking water, reuse

Teacher overview

The fictional town of Palmerton runs two sets of water pipes. Blue pipes carry drinking water from the treatment plant, and purple pipes carry recycled water, which is wastewater the town has cleaned to a level fit for watering and flushing but not for drinking. Purple is the real color code utilities use for reclaimed water lines. In this station rotation, teams sort three use cards into the two bins at each station, twelve cards in all, and the two bins stand for the two pipe systems, so the sorting decision is the same one Palmerton's planners make. A common error students bring to reuse is treating recycled water as dirty water; the point of the sort is that water is matched to a job, and the water in the purple pipe is clean enough for a ball field even though it is not clean enough for a drinking fountain.

Activity Directions

Setup (5 min): Arrange four stations around the room, each with its 3 use cards and two bins. Label one bin at each station "Blue pipe: needs drinking water" and the other "Purple pipe: recycled water is fine." Divide the class into four teams and send one team to each station. Tell students that each station is a different part of the town of Palmerton: a school, a park, a downtown block, and a public works yard. The school station gets school toilets, school kitchen cooking, and gym showers. The park station gets ball field sprinklers, park flower beds, and drinking fountains. The downtown station gets the diner kitchen sink, the car wash, and ice rink cooling. The public works yard gets the street sweeper truck, dust control on a gravel road, and bathroom hand-washing sinks.

Round 1 through Round 4 (24 min total, 6 min per round): At each station, the team reads its 3 cards aloud, discusses each one, and places it in one of the two bins. Every card names a water use and the gallons that use takes in one day. Teams must agree before a card goes in a bin. At the end of each 6-minute round, the team records how many cards ended up in the purple bin, returns all cards to the table, and rotates to the next station. Ring a bell or call time so all four teams rotate together.

Recording and totals (10 min): Teams return to their seats and complete the student handout, which lists all twelve uses and their daily gallons. Students total the gallons in each group and answer the comparison questions. Circulate and check item 2, since teams that misplaced the ball field sprinklers will be off by 1,500 gallons and will need to re-sort that one card.

Debrief (6 min): Ask two questions and take answers from every team. First: which card caused the longest discussion, and why? Second: Palmerton pays to build a whole second set of pipes, so what does the town get back for that cost? Close by noting that the purple bin held more gallons than the blue bin, which is part of why a town in a dry region decides that a reuse system is worth building.

Ending condition: The activity ends when all four teams have rotated through all four stations and each student has completed the handout totals.

Palmerton's Purple Pipe Sort: Matching Water to Its Job — Grade 5 Science
Name: ____________________________ Date: ______________

Student Handout

Palmerton's rule: blue pipe water is for drinking, cooking, showering, and washing hands. Purple pipe water is for flushing toilets, watering plants and fields, washing streets and vehicles, cooling machines, and holding down dust.

Here are the twelve water uses from the four stations in the town of Palmerton, with the gallons each one takes in a single day.

Use Gallons per day
Diner kitchen sink 300
School toilets 800
Drinking fountains 120
Ball field sprinklers 1,500
Gym showers 600
Street sweeper truck 400
Car wash 700
School kitchen cooking 250
Park flower beds 350
Ice rink cooling 450
Bathroom hand-washing sinks 500
Dust control on a gravel road 250
  1. Which of the twelve uses need drinking-quality water from the blue pipe? List them.
  2. Add the daily gallons for every use that could run on recycled water from the purple pipe.
  3. Add the daily gallons for every use that needs drinking water from the blue pipe.
  4. How many gallons do all twelve uses take together in one day?
  5. How many more gallons could run on recycled water than must be drinking water?
  6. The ball field sprinklers use 1,500 gallons each day. If they run all 7 days of a week, how many gallons of recycled water would the ball fields use in that week?
  7. Explain why the school toilets can use recycled water but the drinking fountains cannot.

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: Diner kitchen sink, drinking fountains, gym showers, school kitchen cooking, and bathroom hand-washing sinks. These five uses put water in or on people, so they need drinking-quality water.
  2. Answer: 4,450 gallons. Add the seven purple-pipe uses: 800 + 1,500 + 400 + 700 + 350 + 450 + 250 = 4,450 gallons.
  3. Answer: 1,770 gallons. Add the five blue-pipe uses: 300 + 120 + 600 + 250 + 500 = 1,770 gallons.
  4. Answer: 6,220 gallons. Add the two group totals: 4,450 + 1,770 = 6,220 gallons.
  5. Answer: 2,680 gallons. Subtract the smaller total from the larger: 4,450 - 1,770 = 2,680 gallons.
  6. Answer: 10,500 gallons. Multiply the daily amount by the days: 1,500 × 7 = 10,500 gallons in a week.
  7. Answer: Toilet water is flushed away and never touches a person's mouth, so recycled water cleaned for that job is fine. Drinking fountain water is swallowed, so it must meet the stricter treatment and testing rules for drinking water.

Differentiation

Support

Give these students cards with a small picture beside each use, and sort one card aloud with them as a worked example before the first round. For handout items 2 and 3, provide the addition already written in a column so the student supplies only the sum.

Extension

Ask these students to choose one blue-pipe use from the town of Palmerton and write a short argument for whether new technology could ever move it to the purple pipe, and what testing the town would have to do first. Have them present the argument during the debrief.

ELL supports

Read each card aloud during the first round and let students repeat the use name before sorting. Provide a two-column word bank with "drink, cook, wash hands, shower" in one column and "flush, water plants, wash a truck, hold down dust" in the other, so students can match a card's verb to a column.

Extensions

Have students design a purple pipe sign for one of the recycled-water uses at their own school, using only pictures and a few words so a visitor who cannot read English still knows not to drink from that spigot. Utilities post signs like these wherever a reclaimed line surfaces.