Chapter 7
Solid Waste Audits

In 2008, approximately 250 tons of Municipal Solid Waste (MSW) was generated in the U.S. and of this, about 135 tons was transported to landfills. Recycling efforts recovered about 61 million tons and composting another 22.1 million tons. [13] Per capita waste generation in the United States is on the rise, but recycling and composting rates are increasing as well. [14] The proliferation of waste can be attributed to the growing use of packaging, convenience items, and disposable products. Campuses generate large quantities of waste, much of which can be reduced, reused, recycled, or composted.  

 Waste Audits are a Valuable Tool
Waste audits are one of the most valuable tools for college recyclers in helping to identify the types of waste being generated on campus Identifying potentially valuable materials is an important step to take before searching for markets. Waste audits are useful for: demonstrating the need for creating a recycling program; doing cost benefit analyses of trash versus recycling; creating awareness about waste on campus; gaining publicity for recycling efforts, and also for use as a public education tool.

There are many types of waste audits that vary in complexity. A general dig through the garbage is a great way to get an initial idea of the true picture of the campus waste stream. Waste streams may vary depending on the area of campus so it is valuable to conduct sample waste audits at locations that may differ in terms of the types of materials being generated. For example, dining areas will generate food waste, paper towels, and napkins, all of which can be composted. Art studios may generate a wide  range of materials that can be used in future projects, while dorms are likely to generate office paper, bottles, cans, food wrappers, junk mail, old notebooks and other recyclables. 

How to Conduct a Campus Solid Waste Audit
The timing of a solid waste stream study is important. Conduct the waste analysis during a time that reflects the average level of campus activity (mid-semester or quarter, and mid-week). Remember that the time of year will also affect the research results. For example, more yard waste will be generated in spring and fall than in winter.

Materials/Resources Needed to Conduct a Waste Audit


1. Select Campus Areas
Select three to six areas on campus that represent distinct waste generation locations, such as Residence Halls, Food Services, Administrative Buildings, Student Union, and Academic Buildings. Separate physical sciences and liberal arts (if possible) as waste streams will differ.  

2. Perform a Trial Waste Audit
Prior to the actual audit, conduct a preliminary audit, using a small sample of garbage (five bags, for example). This will help to determine appropriate waste categories and improve methodology for the more extensive waste audit.  

3. Collecting Garbage
Randomly collect a minimum of five bags of garbage from dumpsters at each one of the campus locations prior to the daily waste pick-up. Label each bag according to its collection point.  

4. Calculating Weight and Volume
Once all of the garbage has been transferred to the sorting site, calculate the total weight and volume collected from each location before sorting into separate categories. Remember to weigh the sorting containers before putting garbage into them so that tare weight can be subtracted from the gross weight in order to determine the net weight for each category. Carefully sort each bag of garbage into categories. Once the sorting for one location is completed, weigh the containers of material (subtracting the tare weight) and record the figures. The volume (V) can be determined by multiplying the area of the base (A) of the waste container by the height (H). For round containers, A= ∏r2, where r=radius of the circle, so V=∏r2 H. For rectangular containers, A=LW, where L=the length of the container's base and W=width, so V=LWH. 

5. Separate Waste into Categories
Sort the waste into the categories listed below. Categories can be expanded to reflect a more detailed analysis of recyclable waste. For example, the technology exists to recycle steel-plated tin cans, phone books, and lower grades of paper. However, there may not be existing markets for these materials in the area surrounding campus.  

6. Using the Information
If the total amount of waste that a particular area generates is unknown, represent figures as a percentage. For example, newspaper might represent about 15% of the waste generated within food service areas on campus. If the total weight of all food service wastes is known, multiply that percentage by the total weight to estimate the weight of each waste category. It is important to use both weight and volume figures because weight figures can be misleading. For example, spilled liquids can make paper, particularly newspapers, weigh significantly more than they would if dry.  

Only a small amount of the total campus waste stream can be analyzed in a single day. Use figures conservatively. This will provide important information about the general types and quantities of waste the campus generates. Also, ask the campus and/or local newspaper to cover the waste audit; it is a great photo opportunity.

Sample Collection Tally Sheet

Building: ________________________________________________
Type of Facility: __________________________________________
Total Weight: ____________________________________________
Total Volume: ___________________________________________

Waste Category



  % Total Weight

   % Total Volume

White Paper





Colored Paper





Computer Paper





Low Grade Paper










    Magazines & Books




















Drink Boxes





    Corrugated Cardboard





Food Waste










Total Materials





This can also be done in groupings such as paper, kitchen recyclables, and bottles and cans. Waste audits in public areas are great for educational purposes. For example, take a sample of three bags of garbage from five buildings on campus and sort them in a public area. This sampling could be used to increase public awareness and media attention as well as discussions with potential allies regarding consumption and waste in the community. Publish the results so that they can be easily accessed by a wide range of people.


Food Waste Audits
Food waste audits are conducted to assess food and napkin waste generation in dining halls. This works best with food service areas in residence halls. Enlist a team to monitor the audit, preferably during a meal. Create informational table tents that students can read while they eat. This information should include an announcement of the event and statistics and tips on reducing post consumer food and napkin waste: Take what you need; you can always go back for more! 

Station barrels and volunteers in front of all of the entrances/exits to the dish room. Label the bins: food waste, napkin waste, and trash. Help people sort into these containers before placing dishes in the dishwasher. At the end of the meal, weigh each bag and formulate a report for the cafeteria. Consider per meal and per day extrapolations when adding this up as it will provide good information to support a food and napkin waste reduction campaign including educational activities and potentially composting. This information can be used to complete a cost benefit analysis for handling material as waste versus recycling/composting.  

Mini Waste Audit as a Presentation Tool
Another idea is to take a small waste basket and fill it with items that would commonly be found in an office's waste stream. For the presentation, label four boxes: reduce, reuse, recycle, and trash. Pull each item out of the garbage can and ask the audience to interact and decide into which category each item fits. Take for example a paper cup. The audience would ideally say that is reducible because a refillable container can be used instead. This exercise encourages people to think of the 3 Rs throughout the day.  

Questions to Consider


To Gain Perspective, Get Information

Source Reduction and Reuse
A successful waste management policy supports a resource-conserving hierarchy: source reduction, reuse, composting, and recycling first, waste-to-energy incineration next, and land filling last. Encourage food services to sell reusable mugs, offering a discount on coffee and cold beverages if a reusable container is used. Use metal table ware in food services or reusable plastic ware when possible. Offices can reuse corrugated cardboard, file folders, interdepartmental envelopes, and other office supplies. Establish photocopying guidelines that encourage the use of half-sheets and double-sided copies to reduce paper waste. Utilize campus purchasing contracts to create specifications that reward waste reduction in purchases, service and vendor contracts. 

A campus-wide recycling program, supported and managed by the administration and students, should include an extensive system of source separation for a variety of materials (white and colored bond paper, computer paper, glass, aluminum, recyclable plastics, corrugated cardboard, etc.) The program must target students, staff, faculty, and visitors and should not rely solely on volunteer labor.

Composting and Mulching
Yard wastes and some kitchen wastes can be composted and used as mulch on campus or sold to landscaping businesses off-campus.


A Guide to Waste Audits and Reduction Workplans for Industrial, Commercial and Institutional Sectors                      

California Waste Stream Profiles: Home Page 

EPA. Municipal Solid Waste Generation, Recycling and Disposal in the United States: Facts and Figures for 2008.

Municipal Solid Waste (MSW) in the United States (EPA)                   

Waste Audit and Reduction (Publications by Ontario Ministry of Environment)