Performing a School Waste Audit

The objective of a school waste audit is to introduce the idea to your students and staff that garbage doesn't just disappear once it is collected in your garbage can. You can't just throw it away. It can be compacted, buried, or changed to ash and vapor but the garbage must all go somewhere. This audit will show students the quantity of their waste at school that is recyclable. You can conduct a waste audit of your classroom, school or home using these concepts.

Audit A
Have teachers and students save the garbage from their classroom for one day.
Audit B
Have students conduct a one day audit of classroom and food service waste for one lunch period for the entire school.
Audit C
Have students conduct a visual waste audit of the contents of the school dumpster.

Reducing waste in San Mateo County is an important issue. San Mateo County has one active landfill. AB939 mandates that all California cities and counties must divert at least 50% of their solid waste from landfill disposal by the end of the year 2000. In 2005 San Mateo County disposed of over 792,572 tons or 1,585,144,000 pounds of solid waste (garbage) (Source: CIWMB). Our population in San Mateo County last year was 722,012 (Source: Calif. Dept. of Finance). If we divided the pounds of solid waste by the population of San Mateo County, San Mateo county residents have thrown out over 2,195.45 lbs of solid waste per year. This is approximately 6.01 lbs per resident per day.

How aware are we of the waste we generate? Studies have been done to analyze both the contents of the national waste stream and the waste stream of schools. Paper makes up the largest component of schools' waste streams. (Source: CIWMB, Close the Loop A–46).

Each American throws out about three to four pounds of waste per day. Each student produces about half a pound of waste per school day. All of this adds up to a problem because America's old landfills are filling up quickly… and new safer landfills are very costly to construct (Source: CIWMB, Close the Loop A–46).

Material needed:

Waste audit A:

  • Labeled garbage cans or containers for each classroom or area. These will be used to sort two types of waste (wet waste and dry waste see table below)
  • Plastic garbage bags for each of the containers
  • Two washable plastic tarps
  • Plastic gloves for each student
  • Change of clothes and washable shoes to wear for the activity
  • Parent/guardian permission slip
Waste audit B:
  • Four garbage cans labeled (two for wet waste and two for dry waste)
  • Plastic garbage bags for each of the containers
  • A scale for weighing the materials in pounds.
  • Two washable plastic tarps
  • Plastic gloves for each student
  • Change of clothes and washable shoes for students
  • Parent/guardian permission slip
Waste Audit C:
  • Gloves and goggles for the students conducting the audit
  • Litter pick–up stick (Your school district maintenance staff may have this item)
  • Parent/guardian permission slip

Procedure for waste audits A & B:

Find out if parents and your school administrators will allow the waste audits. Send home permission slips. Students who are not allowed to participate can be responsible for writing the analysis of the audit and charting the activity.

Notify your school custodian of the waste audit. Coordinate with your food service staff to make sure that wet waste generated from the cafeteria is separated from the dry waste.

Wet Waste
Dry Waste
Leftover lunch items, sandwiches, fruits, yogurt, cheese, chips, breads, soups, milk, contaminated paper trays or pizza boxes, used paper towels and tissues.
Candy wrapper, empty potato chip bag, lunch bags, bakery containers, all types of wrappers (i.e. candy, cookies), empty soda or water bottles, any type of paper, plastic wrap or packaging, catalogs, magazines, cardboard, and paperboard.
We recommend contacting your local hauler to obtain literature on the recyclables collected at your site in order to recycle the material at the end of the audit. The information from your hauler will also help the students to determine what is recyclable in your local recycling programs.

Make sure your activity is announced to the school and remind the students before each lunch period of the activity.

It is recommended that you appoint students during the lunch hour to help students sort their waste into the appropriate container.

Your class will be divided into teams, the sort team, the weighing team, the collection of container team, and the analysis team.

If approved, provide the students who will be handling the wet waste bags with goggles and heavy gloves. Spread out two washable tarps and locate the sorting containers as shown on the diagram. Students will empty one bag on to the tarp parallel to the containers. Students will not be sorting the wet waste bags, only weighing.

You are now ready to sort the materials into the appropriate collection container and then weigh and track your results.
Dry Waste Area / Wet  Waste Area

Container Legend
Wet waste sorting area
Mixed paper
Other waste not classified
Plastic wrap and misc plastic 3–7
Aluminum can, steel cans
Plastic Bottles # 1 & # 2

Procedures for waste audit C:

If sorting is not allowed at your site then conduct a visual waste audit of the materials found in the dumpster. Use the litter pick–up tool to break apart the bags and inspect what you find and fill out the table below.

We recommend contacting your local hauler to obtain literature on what is recyclable through your local recycling programs.

Print a Waste Audit Chart in PDF format

Download Adobe's Free Acrobat Reader software from Adobe Systems' web site

Some helpful conversions:

Estimating Weights
One Cubic yard
Est. wt. (in lbs.)
Whole bottles
Aluminum cans
Aluminum cans (crushed by hand)
Steel cans
Steel cans flattened
Newspaper (not compacted)
Mixed paper (flat– not compacted)
PET (soda bottles)


Graph your results of the school waste audit. Compare your data to County or California State data.

Ask students to conduct a survey of school–wide attitudes towards Reducing, Reusing, Recycling and Rotting waste. Some of the questions may be: Do you recycle everything that you can? Would you recycle an aluminum can in a recycling bin if it was located a few feet away, or would you put it in the trash can, which might be closer? If you are not recycling, why not? What would it take to get you to recycle more? Do you make double–sided copies? Do you make your own lunch? If you do make your own lunch, do you put your lunch in reusable containers? Do you have a compost bin? Have you ever heard of AB939? Compile the result of your survey and share it with your school.

How can you educate each other and the rest of the school in order to reduce/re–use/recycle materials?

How many people say they are recycling regularly? How many say they are not? What are their reasons for not recycling, and what do they say would convince them to recycle more (if they are now recycling less than they could) or recycle at all (if they are currently not recycling)? Discuss, analyze, and brainstorm plans to improve participation.

Write a 500 word paragraph on the history of recycling in California.

Permission Slip

On (date)_____________our class will be participating in a study of waste generated by the school. This will involve the handling of school garbage from dumpsters. Students will be provided with gloves and goggles, we will coach them in safety procedures, and every precaution will be taken to ensure your child's safety. A faculty member will be present. We need your permission for your child to participate in this activity. If this meets your approval, please sign the statement below.

If you have any questions please contact _____________________________at School.

My child, ___________________________________________has my permission to participate in the school waste audit to be conducted at School.

Parent signature: __________________________________    Date: _______________

CIWMB: Closing the Loop