A waste audit is performed for each department that participates in PACES. It provides important information about what makes up the buildings waste stream and how it is being sorted. The collection period for a waste audit is anywhere between a week and three days long with the last day consisting of an intensive day-long sorting and weighing effort made possible by a strong volunteer base and participation from partner organizations on campus.

PACES has developed a standardized waste audit procedure (available at the end of the page) that has been reviewed by PACES’ partner organizations and key stakeholders on campus. For buildings which include laboratories, we use a slightly modified procedure.

In coordination with custodial staff, all the department’s waste is collected. At the end of the collection period, interns and volunteers sort the waste by bin origin and material type. The data is then entered electronically and analyzed.

PACES breaks down the waste stream by multiple categories, indicated here. It is important not only to see how much of each material is getting thrown out, but whether it is being placed in the proper bin (e.g. whether a recyclable is being placed in the right recycling bin, the wrong recycling bin, or a trash can).

Standard Material Categories for PACES

  • Office Pack*
  • Supermedia and noncorrugated cardboard*
  • Newspaper*
  • Corrugated Cardboard*
  • Food waste/Compost*
  • Plastics (#1-7, not including styrofoam or plastic bags also called “hard plastics”)*
  • Aluminum *
  • Tin/Bi-Metal*
  • Scrap Metals *
  • Glass*
  • Paper towels and napkins
  • Electronic waste (not including batteries)
  • Batteries
  • Paper cups
  • Styrofoam
  • Restroom waste (not sorted, only weighed and set aside)
  • Miscellaneous garbage*

* = Required category for LEED. If you don’t have this data you can back-calculate from more generalized numbers, however that is time-intensive at the assessment stage and less accurate.

Some criteria to consider before choosing your material categories:

1) What will you use the data for? (examples: LEED, grants, presenting to departments) Accreditation systems and grants will generally ask for particular metrics and divisions of the waste. When presenting to departments, you will want to focus on parts of the waste stream that you don’t understand or that you want to make a targeted change in. For instance, we often break “true trash”, materials that cannot be recycled or composted, into many categories so we can learn what types of waste minimization strategies we need to employ to get to zero. In the past, true trash could make up a significant part of the waste stream and still not be defined. We also track paper cups because we want to inspire behavioral change in building users to use reusable mugs instead and need numbers to back up our campaign.

2) How much time do you want to spend? The more categories, the longer the waste audit and the more volunteers you need. Waste audits are useful, educational, and generally a stinky job that you don’t want to spend more time doing than you have to.

The overarching goal of the waste audit is to determine the department’s potential diversion rate compared to their actual diversion rate. The potential diversion rate indicates how much of building’s material is actually recyclable, whereas the actual diversion rate shows how much of the building’s material is currently being recycled properly.

• Potential Diversion Rate = Total weight of Recyclable Materials/ Total Weight of All Materials

• Actual Diversion Rate = Total Weight of Properly Sorted Recyclable Materials/ Total Weight of All Materials

• Waste Breakdown = Total Weight of Each Material/Total Weight of All Materials (we do this for each type of material we sort)

• Total Weight of Properly Sorted Materials/ Total Weight of Material (we do this for each type of material we sort)

Given these first two numbers, we can determine whether better education is needed about the recycling program, or whether the infrastructure of the program needs to change. The latter two numbers allows us to create focused plans on particular types of materials, to achieve the greatest impact.

Attachment Size
How to Peform a Waste Audit Presentation 9.49 MB
Office Building Waste Audit Guide 134.43 KB
Laboratory Waste Audit Guide 248.37 KB

Back to PACES: Assessment Process

Back to PACES