The purpose of an office waste audit is to quantify the types and amounts of waste being generated within your office. This information can be used to identify solutions for reducing waste in the future. After completing a baseline waste audit, periodic waste audits can be used to measure the effectiveness of waste reduction strategies and progress towards office sustainability goals.
The waste audit process involves weighing all office waste during a specific time (trash, recycling, etc.) to estimate the rate of waste diversion into recycling and to see how much of what is put in the trash could be recycled or replaced with reusable or recyclable options. It also helps you see to rate of contamination in recycling bins, since contamination with non-recyclable items means that all recycling in that bin must be diverted to the trash.
The waste audit can be conducted by office staff or with the help of volunteers. Involving staff in an office waste audit may be a helpful experience, as they can often quickly identify wasteful practices that would be helpful to change. We also strongly encourage you to include students so they can learn from this process, and so we can leverage our campus as a living laboratory. If you would like help identifying student volunteers, please contact the Office of Sustainability.
Time Period
Pick a week for the audit. You want a clear picture of your normal trash output, so choose a week without any special events and when most of your staff will be in the office. Please coordinate with custodial staff and ask them to hold off on emptying the trash that week. If waiting a full week is unreasonable based on the volume of waste generated, a shorter time period is acceptable.
Determine Your Waste Categories
Before the waste audit begins, brainstorm the most common types of waste your office produces. You can add more categories as needed during the actual audit. Common waste audit categories include:
- Glass
- Paper
- Signage
- Cardboard
- Plastic bottles
- General plastic
- Packaging materials
- Food waste
- Aluminum cans
- Other
Equipment Needed
- An open area for sorting the waste
- Gloves and other protective clothing (e.g. goggles, aprons, etc.), if desired, for waste audit team members
- Labeled boxes or tarps for separating waste materials
- Camera
- A bathroom scale for weighing each category
- Trash bags for re-bagging the waste after the audit
- Camera
Sort Your Trash
On waste audit day, the real work begins:
- Gather all the trash and recycling from the office spaces included in your audit.
- Label each trash bag with the location that it came from
- Weigh all the trash to get a baseline for how much is thrown out each week
- Weigh all the recyclables to estimate how much is recycled each week.
- Wearing gloves, sort all the materials from the trash bags into the boxes for their categories. If you labeled the trash bags by specific offices, then each should have separate boxes, or you can do combined categories for your entire department.
- As you work, note any recyclables mixed in with the trash.
- Once everything has been sorted, weigh each category.
Analyze Your Results
Use the recorded weights to conduct a waste stream analysis.
- Calculate and record your waste diversion rate
- Divide the weight of your recyclables by the combined weight of all your waste (trash+ recyclables).
- Multiply the result by 100 to get the waste diversion percentage.
Note: NIU's short term goal is to achieve a 40% diversion rate, with a long-term goal of reaching zero-waste (100% waste diversion rate).
- Look at the weights for individual categories
- Which categories are the highest?
- Did you find any recyclable materials mixed in with the trash?
- Were there categories you didn't realize you had?
Next Steps After a Waste Audit
- Set a goal for increasing your recycling rate.
- If you haven't already, share the recycling guidelines for recycling with staff and students.
- Set a goal for reducing the amount of waste in your largest categories.
- Determine steps to meet this goal and let everyone know. For example, you may switch to a different coffee maker to avoid disposable pods or encourage the use of reusable water bottles or cups instead of single-use plastic water bottles.
- Identify any items you could reuse. For example, can packaging materials be repurposed for anything useful?
- Decide on a timeline for meeting your recycling and reduction goals. One to two years usually makes sense. Plan to conduct another waste audit after that time period to see if you have made progress towards your goals.
- Communicate the results of your baseline waste audit and waste reduction goals with your office.
- Share the results with the Office of Campus Sustainability so we can use this data to track campus sustainability efforts. Optionally, if you'd like to share photos from the event, we will publicly recognize your hard work on social media.