Think Earth 2014/15
Sixth & Seventh Grades
Topic: Food Waste/Composting
Lesson Plan
Learning Objectives:
- Students learn
about food waste
- Students learn
about what’s
required to compost.
- Students learn why
composting is
important
Utah Core
Objectives:
6th Grade: Science,
Standard V
7th grade: Biology,
Standard 1
Time:
40 minutes
Materials Needed:
- U-tube Food Waste
video
- U-tube Compost
video
- Compost samples
- Recycle box
- Landfill pie chart
Spare time
Activities:
- Posters
Handouts:
- How to compost
- RU tri-fold
1. Introduction (review of Recycle Utah, recycling, sorting and Mother
Earth). What can Not go into curbside? What is each
material made from (iron ore, sand, trees & oil) – all Natural
resources! What we’re going to talk about today is outside of the
usual recyclables, but it’s something we can All relate to: Food.
(5-10 min)
2. Utube video (3 min)
http://www.multivu.com/players/English/45656-Sodexo-Food-Waste-Reduction/
3. Food Waste Discussion (5 minutes)
Where does food get wasted? Make a list of ideas on board
(Schools, restaurants, farms, supermarkets, stadiums, etc..)
Review attached sheet and discuss food waste. Show pie chart.
Ask the students for ways we could reduce it in the future?
Introduce Methane and discuss the connection (show attached
graphic about greenhouse gases).
2. Introduction to Composting. (5 minutes)
What about in our homes, too? Make a list. Hint: Explain that
anything that is or was once from something alive’ is compostable.
Ask for examples - get a scribe to write them on the board. Provide
hints. Once a long list is shown, pass around a bucket full of recent
compostables (and how many days/people it was from). Know the
weight. Start calculating for a week, then year. It adds up! Imagine
what it is for a restaurant, grocery store or school!
3. Compost Science (5 min)
Composting is fun and easy! Pass around samples – mid-way
and Complete (Black Gold). Explain Carbon vs. Nitrogen + Oxygen &
water. Talk about biodegradation vs. decomposition. Then where
do we get our food from – soil! Compost is a part of the life cycle
and 30% of landfill waste is Compostable!
3. Composting video: (4 minutes)
http://www.youtube.com/watch?v=Njbn34JrKnE
Key Concepts:
We have too much trash in our world. 80% of what’s in landfills does not need to go there. 30 % is
compostable. Methane from landfills contributes to our climate change problem. Humans need to
make changes – composting is one way. There’s still a lot of work to be done.
This lesson plan is
made possible by a
grant from Vail Resorts
Recycle Utah, 1951 Woodbine Way / PO Box 682998, Park City, UT
84068.
PH: 435.649.9698. Recycling drop open 24/7.
Visit us at www.recycleutah.org
PIE CHART:
http://www.epa.gov/waste/conserve/foodwaste/
Compost Lesson/Experiment (25 minutes):
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Give Compost definition and discuss difference between Biodegrade & Decompose.
Make list (in their small group) of everything they think is compostable. From the
lists, make overall list on board.
Make list of materials they think are not compostable (eg plastic bags, bottles, cans,
etc…). Make sure to add meat & dairy (rodent attractors). Discuss lists.
Discuss what’s needed to compost: carbon, nitrogen, oxygen & water. Discuss green
vs. brown and 3:1.
Distribute a sample, lab report, gloves, scratch paper, magnifying glass and handout
to each group. Briefly review the Organism side of sheet (will you find any of these in
a sample?) Each group is to study their sample for 5 min and jot down any
observations they see (color, texture, smell, bugs, moisture, etc..). Designate a
“handler” and a “reporter” for each group.
Rotate the four samples (labeled by color?) to each group. When finished, the groups
are to guess the order of the samples 1 – 4 for the compost stages (1 and 4 will be
easy). Discuss observations. Ask all how long they think the process takes? Discuss
the variables (temperature, water, air, turning, etc…) Where might composting be
most successful in our country? Look at other side of the handout “It’s Easy to Start
Composting.”
Compost Information
- Composting is a way to control the natural process of organic material decomposition. If
decomposition didn’t occur, forests would be piled high from fallen leaves. Compost = Decayed
organic material used as a plant fertilizer.
- In the U.S. 13% of the MSW stream is yard waste and 10% is food waste. Organic waste
decomposition within landfills is a main source of both methane and leachate. And, food wastes
are normally wet, so don’t burn well in waste combustion.
- Decompostion (“to separate into elements or basic components; to cause to rot”) refers to the
overall breakdown of organic matter. As plants and animals decompose, they release important
nutrients and moisture back into the soil and water. The process by which organisms take in
nutrients, die, decompose, and release nutrients into the soil and water for other organisms to use
is called nutrient cycling. Biodegradation (“be decomposed by bacteria or other living
organisms”) is a natural process carried out by a multitude of living organisms including bacteria
and other microorganisms, fundi, mites, beetles, and earthworms.
- Through composting, humans manipulate decomposition and nutrient cycling. Composting uses
biodegradable organic materials as the base for decomposition. Key components in composting
are the carbon-to-nitrogen ratio (3:1), moisture, oxygen and temperature. Carbon (C) is the energy
source for the microbes. Nitrogen (N), a protein component, is needed to build new cells allowing
microbes to grow. Nitrogen
sources are “green” materials (grass, food scraps, coffee
grounds) and Carbon sources are
“brown” (dry leaves, twigs, paper, sawdust). If the ideal
ratio isn’t maintained, problems can occur (slow progress, odor, low heat, too dry, etc…)
US WASTE INFO
According to the Environmental Protection Agency, the average American produces about 4.4 lbs. of
garbage a day. That’s 29 lbs. per week or 1,600 lbs. per year. The United States produces
approximately 220 million tons of garbage each year. This is equivalent to burying more than
82,000 football fields six feet deep in compacted garbage. This amount of trash could cover the state
of Texas two and half times and also fills enough trucks to form a line to the moon. Where does it all
go? A lot of our trash ends up being buried in a landfill. The U.S. has 3,091 active landfills and over
10,000 old municipal landfills, according to the Environmental Protection Agency. Anything that
goes into a landfill is covered with layers of clay and other materials that basically mummify the
remains. This means that without air and water, our trash has become our archival remains for
future generations. This may sound culturally resourceful, except landfills are the largest humanmade methane source in the United States. Once methane is released into the air, it becomes a
greenhouse gas. And then there is the toxic leachate, or liquid that seeps and drains from a landfill,
that ends up in our aquifers.
More food reaches landfills and incinerators than any other single material in
municipal solid waste (MSW). In 2010 alone, more than 34 million tons of food
waste was generated, with only three percent diverted from landfills and
incinerators for composting.
How Can I Divert Food From Landfills?
• Source Reduction/Prevention
Preventing food waste before it is created
• Feeding People
Donating fresh, wholesome food to those in need
• Feeding Animals
Feeding safe, fresh food scraps to animals like pig farms
• Industrial Uses
Rendering fats, oils, and grease and turning it into products or
biofuel
• Composting
Turning food waste into a valuable soil amendment
• Anaerobic Digestion
Turning food waste into renewable energy and a valuable
soil amendment
Why Divert Food Waste From Landfills?
Reducing the amount of food wasted has significant economic, social &
environmental benefits:
Environmental Benefits
• Reduce Methane From Landfills - When food is disposed in a landfill it rots and
becomes a significant source of methane - a potent greenhouse gas with 21
times the global warming potential of carbon dioxide. Landfills are a major
source of human-related methane in the United States, accounting for more
than 20 percent of all methane emissions.
• Reduce Resource Use Associated with Food Production - There are many
resources needed to grow food, including water, fertilizers, pesticides, and
energy. By wasting food, you are also wasting the resources that when into
growing it. Additionally, 14 percent of greenhouse gases in the United States
are associated with growing, manufacturing, transporting, and disposing of
food. By reducing the amount of food wasted, we can reduce greenhouse gas
emissions.
• Create A Valuable Soil Amendment - Recycling food waste and turning it into
compost has many environmental benefits such as improving soil health and
structure; increasing drought resistance; and reducing the need for
supplemental water, fertilizers, and pesticides. Food waste can also be turned
into renewable energy and a soil amendment through anaerobic digestion.
• Improve Sanitation, Public Safety, and Health at Your Facility - Food waste
dumped in standard trash cans and dumpsters in the back alley of a home,
store or restaurant can generate bad odors and attract rodents or insects.
Placing food scraps in a closed, leak-proof, durable, and reusable container,
and having it frequently emptied for donation or composting can significantly
reduce, and even eliminate these problems.
Economic Benefits
• Lower Disposal Costs - By decreasing the amount of food wasted, businesses
pay less to dispose of their trash. Some haulers charge less if the food waste
is separated from the trash and sent for composting rather than landfilling.
• Reduce Over-Purchasing and Labor Costs - By making strides to prevent food
waste, businesses can reduce costs by purchasing only the food that will be
used, or decreasing improperly prepared foods. Additionally, reducing food
waste can increase staff efficiency and reduce energy and labor associated
with disposing of food.
• Receive Tax Benefits by Donating Food - By donating wholesome and edible
food to food banks or food rescue organizations, businesses can claim tax
benefits as well as feed those in need.
Social Benefits
• Feed People, Not Landfills - An estimated 50 million Americans do not have
access to enough food. Organizations can donate safe and healthy food to a
food bank or food rescue organization and both reduce food sent to landfills
and feed those in need.
Wastes Home
33 million tons of food waste reach landfills each year in the United States. This food could
be prevented, used to feed people, or composted to create a valuable soil amendment.
Resource Conservation Home
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