Prepare the sorting area. Using the sample collection method, collect and label sample waste bags from all sampling categories. Explain method to volunteers and assign roles. Beginning with one particular sampling category, record each bag’s label prior to sorting. Open the bag, spread its contents on the ground, and sort the bag’s contents into the appropriate receptacles. Repeat the weighing and sorting procedures for all bags in a sampling category. Weigh and record all individual sorting receptacles. Repeat this procedure for all sampling categories. Properly dispose of sorted materials and clean area.
Safety Requirements
Because a waste audit requires contact with non-hazardous waste and potentially involves contact with sharp objects, it is necessary to comply with personal protective equipment (PPE) regulations from Indiana University’s Office of Environmental, Health, and Safety Management. A PPE Hazard Assessment from that office has mandated the following minimum PPE requirements:
• Multi-task neoprene-coated standard work gloves • N-95 nuisance dust masks
• Safety glasses with side shields • Sturdy, closed-toed shoes
• Full length pants and a shirt with long sleeves • Bag-cutting tools for remotely opening bags
If materials are found that are suspected to be hazardous, cease the task immediately and contact the Office of Environmental, Health, and Safety Management (812-855-6311).
Equipment and Supplies
Appendix B contains a list of equipment, supplies, and PPE necessary for conducting an audit.
Audit Preparation
The following steps will help the researcher design and prepare for a large building audit. These steps are outlined in a checklist format in Appendix A.
1. Define goals
Clearly defined goals are essential to developing appropriate sampling techniques. Consider including a control if a goal is to compare a building’s waste stream before and after implementing or updating a waste diversion program (see Waste Audits: Use and Design).
31 2. Analyze the building to be audited
Spend time walking through the entire building, noting the location of all types of waste receptacles. Take note of parts of the building where the waste stream might be different (i.e. cafés or student/employee lounges vs. classroom or office space) and which parts of the building may be similar (i.e. two building levels have similar floor plans and usage). Visually inspect a few receptacles to identify special categories that may be need to be included in the audit (i.e. paper cups or food waste in a café area, cardboard or junk mail in a mail receiving area, newspapers near newsstands, etc.). Record your findings and take pictures if necessary. Conduct these initial observations after hours, on weekends, or with a Building Services staff member in order to access parts of the building which may be in use or off limits during peak hours.
3. Consult building maintenance staff
Organize a meeting or conduct interviews with building maintenance staff for information regarding the existing waste management system (Kenlon et al. 2010). Helpful questions to ask include:
• How and when is waste collected?
• Which parts of the current waste management system present the most difficulties? • How could a new system make their job easier?
• Is litter or waste left around rooms a problem? If so, do they have suggestions for reducing or eliminating it?
• In what sections of the building is the waste stream different from others? • What is the easiest way to collect bags for the audit?
4. Identify sampling categories*
This method suggests the “activities approach” (see Types of Waste Audits) in order to obtain more detailed data from an audit. This requires the researcher to identify different types and locations of waste and audit them separately.
Types: While most audits look only at trash, it may be useful to also audit recycling containers. This will show the contamination rate of those containers (important because some recycling haulers only accept bags containing less than a certain amount of contamination) and could be used to compare the contamination of solitary containers to those paired with other waste types.
Locations: In addition to auditing different types of waste, further separating them by location will yield more detailed results. Separate receptacles by where they are or how they are used. For example, receptacles in a heavily-used public space such as a hallway on a main floor of a building are likely to be different from those in a single-occupant office on the topmost floor. Examples of location categories include hallways, classrooms, offices, outdoors, high/low traffic areas, student/staff use areas, dining facilities, break rooms, mailrooms, and bathrooms. Identify sampling categories by combining the waste types and locations to be audited. For example, a 2011 study of Indiana University academic buildings interested in discovering the
32 composition of trash and degree of contamination in paper recycling containers had six categories: hallway trash, hallway paper recycling, hallway bottle/can recycling, classroom trash, classroom paper recycling, and office trash (Milby 2012).
*If the study contains a control building, a high level of detail may not be necessary for the control. The purpose of the control is only to show that changes in the test building were not caused by daily or seasonal variations.
5. Select sample sizes
Sample size is a compromise between statistics and a realistic workload. Although sampling error could be reduced to zero by auditing every waste receptacle in a building, this is usually impossible for large buildings. In such cases, a 10 – 25% sample size is recommended (CCME 1996). Find this number by estimating the total number of receptacles in a sampling category and multiplying that number by the desired proportion (e.g., 25 hallway trash receptacles x 25% = approx. 7 samples needed).
6. Prepare a collection procedure
See sections 3.1 and 3.2 of the next section, Audit Procedure. 7. Define sorting categories
Refer to the study’s goals to help define sorting categories. In general, the more specific the sorting categories, the more the study will reveal about the building’s waste. Categories should be created with the intent to provide information that will highlight opportunities for waste diversion (CCME 1996). Successful audits typically have between 5-15 categories such as newspaper, office paper, paper cups, paper towels, aluminum cans, plastics 1-7, glass bottles, compostable or organic materials, certain branded materials, electronics, batteries, and food containers. A 2012 litter study at Indiana University separated items into individual brands, and thus had 85 categories (Milby 2012). Note that volunteers will need each category explained in full and described on signs above each sorting container during the audit.
8. Create data recording sheets
Data recording sheets should be intuitive and easy to use. See Appendix C and D for examples. During the audit, provide clipboards and designate volunteers as recorders. This also offers volunteers a break from sorting (or an alternative to sorting).
9. Gather materials
Gather the materials described above in the Safety Requirements and Equipment and Supplies sections and ready them for use. Prepare a plan for transporting materials to and from the auditing site. This may involve securing on-campus parking and a vehicle. Use Appendix B: Materials Checklist to inventory the materials before and after the audit.
10. Select an audit location
The proper location balances space and safety needs with publicizing the audit. The audit should be held close to a building entrance on a flat, impervious surface out of the way of
33 vehicle and pedestrian traffic, ideally under cover in case of rain. The location absolutely must minimize wind. Be careful to not let liquid from waste bags drain into vegetation or storm drains. If possible, consider holding the audit near a high-traffic walkway or public space. Use signs to explain to passersby what is happening. If the audit location is not highly visible, post signs in nearby buildings instructing inhabitants where to go to observe or volunteer.
11. Select an audit date and time
Because an accurate sample includes waste from one full business cycle, synchronizing an audit with normal custodial operations is crucial (CCME 1996). The audit date will be a compromise between custodial operations and volunteer availability. If a compromise between these two times is not available, collect and store samples before the audit, and then transport them to the auditing location just before volunteers arrive (for the sample collection procedure, see section 3 of Audit Procedure). Be conscious, however, of sanitation needs – to prevent spoiling or attracting animals, do not store waste bags outside or for more than one day.