The Cornell Waste Management Institute

Testing Leachate

Adapted from Waste Management Awareness Attitudes Activities, St. Lawrence County, NY
Back to Trash Goes To School

SUBJECT AREAS: biology, chemistry, earth science
CONCEPT: Landfills, compost piles, or any other concentration of waste produces leachate.
OBJECTIVE: To realize what leachate is, where it comes from, and what its properties are.
- waste materials
- 50 ml. graduated cylinder
- water
- separatory funnel
- pH paper
- hardness paper
- turbidity tester
- bunsen burner
- sparker
- platinum wire
- test tubes
- handout: Leachate Data Table
KEYWORDS: turbidity, hardness
BACKGROUND: Students will know what makes up a landfill. In the lab an artificial landfill will be set up and tested.
Landfills do not contain just solids, but also liquids and gases. Leachate is liquid that may leak from a landfill. Leachate forms from a combination of liquids that are dumped, liquids that form through decomposition of wastes, and precipitation filtering through the wastes.
In older, unlined landfills, leachate drains into nearby streams or into the underlying groundwater. Modern, lined landfills are designed to include systems for leachate collection and treatment to prevent such contamination problems.
You may want to try to obtain a leachate sample from a landfill, or you can create your own leachate (See How Do Landfills Work?, levels 7-8).
1. Students will define leachate, pH, turbidity, hardness, flame test.
2. Students will use the following correctly: a separatory funnel, graduated cylinder, and other laboratory materials.
3. Students will determine the pH, turbidity, hardness and some ions in the leachate.
4. Students will discuss why it is necessary to cap landfills on the top and have a liner on the bottom to minimize environmental problems.
5. To make a landfill, add representative samples from your lunch to the separatory funnel until it is approximately half full. Add 50 ml. of water (this represents rain water) and put on the top and shake for 1 minute.
6. Wait ten minutes and then draw off 10 ml. of leachate into the graduated cylinder.
7. Do the following tests: pH, hardness, and turbidity. Record the results on the Leachate Data Table. Repeat procedures over a period of days, using new samples each time.
Test stream, lake, pond, and tap water, and compare the results to those from leachate.

Leachate Data Table
Test Results

 Day 1  Day 2  Day 3  Day 4  Day 5

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