2019 Municipal Composting Study
Food waste is a mounting issue in the United States, with 133 billion pounds of all food intended for consumption wasted each year. This waste poses significant economic and environmental issues. Global food loss accounts for almost 8% of total greenhouse gas emissions, while also amounting to hundreds of billions of dollars lost in product every year.
At the city level, these problems become even more pertinent. Durham residents produce 27,000 tons of food waste each year; approximately 30% of all the products going to the landfill are either food waste or paper products. The growing size of landfills is an increasing factor in climate change as one of the leading producers of methane, but also contributes to a slew of local environmental and public health problems. The City of Durham spends hundreds of thousands of dollars every year hauling waste to a landfill in a neighboring county.
A possible solution to reduce the volume of waste going to landfill is municipal composting. Composting is a process that recycles organic waste materials into a rich soil through natural decomposition. In 2019, the City’s Innovation Team (I-Team) partnered with the Solid Waste Management Department and the Center for Advanced Hindsight at Duke University to conduct several resident-based evaluations for designing and implementing a city curbside composting program.
The goals of this project were to:
- Understand the public's perception and openness to composting
- Explore how to effectively implement a city curbside composting program with Durham residents
- Examine how residents can best be enabled to participate in the program and minimize contamination
- Gather input from a wide array of city residents representing various neighborhoods across the city, household sizes, income ranges, and historically underserved communities
- Consider how the City’s collection crews perceive the process and use findings for co-design
The team analyzed the issues at hand and potential solutions in three steps:
Survey and Interviews: The team first issued a city-wide survey to gauge opinions and insight on composting from Durham residents. The survey received almost 4,500 responses and provided a basic understanding of residents’ familiarity with composting, how they felt about composting, how they might take up composting and how they felt about a potential city food waste collection program. After the survey, some of the respondents were interviewed to foster a deeper qualitative understanding of the responses. The team also conducted professionals from other cities that had implemented municipal composting programs across the country. Additionally, the team also held a focus group with the City’s Yard Waste collections crew to gather input about the collection process and what on-ground issues should be considered.
Prototype A: Using the findings from the qualitative research, the team launched a prototyped-version of a composting program in summer 2019. Eight Durham residents representing a diverse set of household demographics and without prior composting experience were recruited to participate over the course of two weeks. Each resident was provided with a 1.5 gallon indoor bin to gather food waste, green “bio bags,” informational material detailing guidelines and background, and a WhatsApp line to communicate and document their progress and any questions. The process included weekly collections by team members who examined the material for contamination. Participants completed a survey and participated in in-home interviews and the conclusion of the two weeks. Prototype A sought to gain a preliminary understanding of equipment needed, the collection process, contamination, and user knowledge and experience.
Prototype B: Gathering the insights and experiences from Protoype A, the team launched a second round of the prototype in fall 2019. Seven yard waste customers were selected to participate. The residents were provided with either a 25 or 35 gallon outdoor container, a limited amount of green “bio bags” with additional paper bags, a 1.5 gallon indoor bin with a Do’s and Don’ts guideline attached, and consolidated informational material. The collection process followed the same weekly cycle but was conducted with Solid Waste Management staff. Prototype B expanded the review of user experience with added equipment and infrastructure and gathered input from the collection crews. Participants again completed a survey and in-home interviews.
RESULTS AND RECOMMENDATIONS
The city-wide survey yielded a large set of data and takeaways on how Durham residents understand composting and a potential municipal program.
The survey showed that almost all respondents had at least some familiarity with composting, and the majority (58%) were either very or extremely familiar with the practice. Moreover, almost half of respondents currently compost and close to 30% have composted in the past. Respondents with no composting experience were mainly deterred by uncertainty and confusion about the process. The biggest reason cited for not composting was that they simply didn’t know how. Most non-composters said they would compost if someone picked food waste up from their house, but also emphasized that just learning the process would be a big factor in starting. The group generally said that increasing the ease of composting would make it more encouraging to participate; this included help with the initial setup in homes and city-provided resources. Among those who used to compost, the biggest reason cited (24%) for stopping was moving to a new city or situation where rules against composting were in place. Over 60% of ex-composters said they would start again if someone picked food waste up from their house. Those who currently compost said they began the practice because it benefits the environment, with limiting landfill waste as the most popular reason cited for composting. The general consensus of composters was some form of the practice “being the right thing to do.”
Prototype A provided an initial glimpse at hard numbers and detailed the experience of first time composters with a city program. Over the two week period, 216.8 pounds of food waste was collected, an average of 13.55 pounds per week for each household. Almost all of the items collected were compostable, with some instances of contamination. Prototype B yielded less total compost collected, but saw more efficient practice. In total 104.35 pounds of compost was collected and minimal contamination was discovered.
During and after the prototypes, insights from participants on their experiences were gathered and recorded. Among the most positive takeaways was that people were generally surprised by how easy food waste collection turned out to be, with residents saying they “thought it would be more complicated.” In practical terms, participants found the process easier to follow than the rules surrounding recycling. Once people became comfortable with how composting works, they adopted practices that worked best for them. Participants of Prototype B especially enjoyed the 25 gallon cart provided, which was not only seen as the most convenient size but the most effective and aesthetically pleasing. Participants especially appreciated receiving feedback and being able to see the statistics related to their participation. People also found the process more exciting and interesting than they expected, and wanted to know what happens to their food waste after it leaves them. The prototypes generally fostered better understandings about waste from residents. The prototypes also elicited somewhat of a community effect, with residents wanting to spread composting to their neighbors and encouraged communal practices.
The team also observed several potential issues with the prototypes to consider in future evaluations. While collections remained mostly uncontaminated, there was still some confusion on what items could and could not be composted. Some participants would rather risk putting a dubious item into the compost than in the trash, hoping that someone on the receiving end would sort it out. Paper items were consistently the most confusing items and the messaging about what materials were and weren’t compostable prompted some uncertainty. The biggest barrier for getting people involved, especially less resourced households, would be a potential cost to the future program. Several participants pointed to making the program more fiscally accessible as one of the more pressing issues for the team to consider.
"I was excited to see all the things that were compostable. I liked that I could do dryer lint, candy, things that I didn't expect - and didn't expect to appreciated . . . because I didn't know it existed."
- Resident Participant
WHY IT MATTERS
The team's efforts with this project have laid the groundwork for a curbside composting program and will guide the future implementation in the City of Durham. Using a variety of methods that center user-experience as the focal point of analysis, the team hopes to design a program that works for all residents and Solid Waste Management collections staff. The City is using the results of this research to explore how a municipal curbside program can be implemented to maximize efficiency and compatibility for residents. Future phases of this research include a 100-household pilot program and a larger experimental study that will be used to quantify the anticipated environmental and community benefits of a citywide program.