Imagine your library property is home to a lake. It is a lovely lake. People like to picnic around its clean, sparkling water. Now imagine that all sorts of icky stuff inadvertently ends up in the lake. What do you do to clean it up?
This premise is the basis for a program that explores different methods for cleaning up a body of water, and how some of the stuff that may be in our water gets there. The basics for this program were borrowed from an old Girl Scout program called Water Wonders that I have been involved with as a volunteer in the past. This particular program works even if you have no near-by body of water, and will help to make it clear that water pollution is a problem for everyone, and that the solutions are the responsibility of everyone. And the kids have a lot of fun doing it!
First, select some water-related stories and non-fiction books to share; either for reading or simply for display. Some titles that I like include:
These Seas Count!, by Alison Formento
My Great-Grandmother’s Gourd, by Cristina Kessler
Anna Carries Water, by Olive Senior
Clean Water, by Beth Geiger
You Wouldn’t Want to Live Without Clean Water! by Roger Canavan
How Big Is Your Water Footprint? by Paul Mason
And then set up for your lake-cleaning story and exercise. For this program, you will need the following:
- several “lake” holding basins. clear plastic is optimal, but any type of pan (such as an aluminum roasting pan) will do.
- small, labeled containers of each of the following; one of each per group of students
- cooking oil, labeled “oil”
- powdered laundry detergent, labeled “diaper service”
- garlic salt or powdered garlic, salt and pepper (mixed together), labeled “home”
- tiny cut up bits of styrofoam, as from a styrofoam cup or packing peanuts, labeled “picnic”
- potting soil, labeled “farm”
- phenolphthalein in isopropyl alcohol, labeled “chemical P-9” **this should be handled by an adult only** labeled “factory” (see note below)
- vinegar, labeled “purifying agent”
- small fish nets – one per group
- cotton balls – two or three per group
- two plastic cups per group
- a paper coffee filter per group
- a small container of mulch per group
- small funnels
- a small container of sand per group
- A copy of the story below, edited to fit your circumstance.
- baby wipes and/or hand sanitizer
- plastic gloves
The story of Library Lake
On the outskirts of town, there is a beautiful, clean lake. Recently the farmers have plowed their fields, and when it rained last night some of the soil washed into the lake. (Each group dumps “farm” contents into their lake.) At a gas station, a mechanic accidentally poured some oil on the ground by the back door of the service bay. It seeped into the water supply when the rain washed it off the parking lot. (Each group dumps “oil” into their lake.) On the other side of town, a factory worker poured a container of “chemical P-9” down the wrong drain, leading it to the water supply and not to the hazardous waste. (Each group gets 2-3 drops of P-9 added to their lake by an adult.) After dinner, as the people in the town wash their dishes, spices from their food end up in the water supply too. (Each group dumps “home” into their lake.) Picnickers at the lake yesterday left some trash outside the trashcans; as the rain storm blew in, it washed some of the trash into the lake. (Each group adds “picnic” to their lake.) Finally, the diaper service company in town used too much detergent, some of which also ended up in the lake from their drains. (Each group adds “diaper service” to their lake. This, when combined with the P-9, should turn the water pink.) At the end of the week, does the lake look beautiful and clean? All the towns people now need to gather to figure out a way to clean up their lake!
Next, each group has the above-mentioned materials with which to attempt to create a “clean” water sample. The goal is not to clean the entire lake, necessarily, but to produce the cleanest sample possible. Minimal instruction, other than that they should not taste the water or get it in their eyes, should be offered. Give the students 15 minutes or so to produce the cleanest sample they can manage. Then re-group to compare notes. Depending upon the age of your group, you can discuss the difference between point and non-point source pollution, and try to identify all the various types of pollution in the story. Ask the students if everything could be removed from the water in their sample. They should note that while the purifying agent (vinegar) removes the ‘pink’ from the water, it’s impossible with the given supplies to remove the smell of the garlic, for example. You may wish to chart the effects of each different cleaning supply and method.
Note: to purchase phenolphthalein, which is an indicator solution, you can google “phenolphthalein isopropanol solution.” Small dropper bottles will cost about $8 each, and only one would be needed for several iterations of this program. This can be simply left out of the story if use of this chemical is not advised. Contact with skin could potentially cause problems, as could inhalation or ingestion. (Contact a poison control center for ingestion.) Although I have not tried it myself, red cabbage indicator solution may substitute for this chemical and still give the color change, as what it indicates is basic/acidic reactions. I have done this both with and without the chemical. The color change is all you lose by not using it. Whether you use the chemical or not, caution your students not to drink the water, or to put their hands in it more than necessary. Make sure that all students wash hands thoroughly following the program.
I have used this program with kids from age 6 to middle school age. Closer supervision is necessary with the younger kids, but while doing it without the chemical, I had no concerns about contact with the water. The students I have done this with were very engaged, and usually want to work on their sample much longer than the allotted time.