Waste Audits and Waste Characterization

How Waste Audits Can Guide Sustainability

What’s in our trash—and what can we do about it?
A school waste audit or waste characterization study is a hands-on tool that helps schools identify what types of materials are being thrown away, how much could be diverted through recycling or composting, and what steps can be taken to reduce waste overall.

Why Conduct a Waste Audit?

Waste audits give school districts the data they need to create informed sustainability policies. By examining a representative sample of waste, schools can:

• Identify high-volume materials that could be recycled, composted, or reused

• Find opportunities to reduce waste at the source (e.g., packaging in cafeterias)

• Measure the effectiveness of current recycling and composting programs

• Set a baseline to track improvements over time
  
  

Student Involvement: Learning in Action

Waste audits are a great opportunity for student-led learning and service. Schools can involve middle or high school students in every step of the process—from sorting and weighing materials to analyzing the data and presenting their findings to school administrators.

Bonus: Students can earn community service hours by participating in a waste audit, turning this sustainability initiative into a real-world learning experience that meets graduation or extracurricular requirements.

How Does a School Waste Audit Work?

Conducting a school waste audit can be simple and safe with a clear process in place. Here’s how it typically works:

1. Plan and Get Buy-In

• Get approval from school administration and coordinate with custodial staff.

• Identify a teacher, Green Team advisor, or municipal waste/recycling coordinator to guide the process.

• Recruit student volunteers and assign roles—safety monitor, sorter, data recorder, etc.

2. Select a Representative Sample

• Choose a location and timeframe to audit—e.g., one day’s worth of cafeteria waste, or a full hallway’s worth of classroom trash and recycling.

• Avoid vacation or testing weeks to get normal behavior data.

• Label and store collected waste in bags or bins, and store in a safe location for sorting.

3. Set Up a Sorting Station

• Pick a well-ventilated area like a loading dock, outdoor overhang, or unused gym space.

• Lay down a tarp or plastic sheeting to protect the ground.

• Set up bins or boxes labeled for categories: food waste, recyclables, paper, plastic, trash, liquids, etc.

4. Be Safe

• Everyone handling waste must wear gloves (preferably puncture-resistant), safety goggles, and closed-toe shoes.

• Wash hands thoroughly afterward and avoid sorting sharp or hazardous materials

5. Sort and Record Data

• Weigh each category of waste using a digital or hanging scale.

• Count common items (e.g., number of uneaten milk cartons, plastic utensils).

• Record all findings in a spreadsheet or tally sheet.

6. Analyze the Results

• Calculate total waste generated and percentage of recyclable or compostable materials.

• Identify the largest waste categories and biggest diversion opportunities.

• Turn the data into graphs or visuals to present findings.

7. Make Recommendations

Use the results to recommend changes like:

• Adding food waste composting in the cafeteria

• Improving signage on recycling bins

• Encouraging reusable utensils and containers

• Running student-led awareness campaigns

Turning Trash Into a Teachable Moment

When students see what’s going into the garbage firsthand, they understand the impact—and the opportunity. Waste audits help build leadership, data literacy, and environmental responsibility, while helping schools move toward smarter, more sustainable systems.

Interested in running a waste audit at your school?
Contact your municipal waste coordinator or sustainability educator for support, tools, and templates to get started!