Re-examining the Holistic Benefits of Composting + Compostable Packaging
Framing composting as a means of diverting waste from landfill, especially food waste, is an alluring idea. Composting not only reduces the volume of material heading to landfill or incineration and dramatically minimizes associated greenhouse gases, but compost itself provides a host of benefits. Using compostable packaging as a vehicle to deliver food scraps to bins collecting compostable material is an effective strategy, as illustrated in the SPC’s Value of Compostable Packaging Report.
Yet, composting as a landfill diversion strategy just scratches the surface of its benefits. Beyond landfill diversion, composting promotes soil health and plant yields as well as sequestering carbon. Pashon Murray, founder of Detroit Dirt, spoke at SPC Impact 2018 on how composting and compost can help “draw down” the 880 gigatons of carbon dioxide that humans have emitted into the atmosphere.
Whether composting animal waste from the Detroit Zoo, food waste, or fiber, Murray highlighted that the process is key to “getting the [carbon] cycle back in balance.” Murray’s emphasis on pulling carbon down from the atmosphere helps affirm composting as more than a landfill diversion strategy and instead a method of reversing climate change. In fact, she underscored that “applying a thin layer of compost one time sets up an ongoing feedback loop that pulls increasingly more carbon each year,” into our soils.
Healthy soils, as Murray attested, is pivotal to developing regenerative agriculture. She cited United Nations’ findings that at our current rate of topsoil loss, we have approximately 60 harvests remaining until our soil cannot support farming. Compost not only helps prevent soil erosion, but it also helps water retention, which is critical for regions experiencing more frequent and more severe droughts.
Pete Chism-Winfield, Materials and Waste Specialist for the City of Portland, explained that in the greater Portland area, there is incredible demand for high quality compost for agricultural applications. Similarly, Jack Macy, Senior Zero Waste Coordinator for the City and County of San Francisco’s Department of the Environment, explained that a majority of compost produced by their program is used on vineyards, grazelands, or other agricultural uses.
Portland and San Francisco aren’t alone in fostering resilient soils and a regenerative agricultural system. Neil Edgar, co-founder of the California Compost Coalition, explained that the state as a whole directs the majority of compost produced to agricultural applications. Because so much compost goes to agriculture to rebuild stressed soils, Edgar and Macy pointed out that the compostable packaging community must be extra mindful to ensure that compostable packaging doesn’t bring unwanted chemicals to soil, especially when that soil is producing food.
Sego Jackson, Strategic Advisor for Waste Prevention and Product Stewardship for Seattle Public Utilities, made clear that Washington state is very concerned about a class of chemicals called per-and polyfluoroalkyl substances (“PFAS”) used to add oil, grease, and moisture resistance to fiber and paper-based food packaging materials given that they are designed to be composted. This class of chemicals are very persistent in the environment and many bioaccumulate in mammals and may impact human health. Industry has been working to phase out substances that have longer carbon chains such as PFOA and PFOS and replacing them with shorter chain substances. However, in a separate panel session we heard that short chain PFAS are more mobile in soils and are more easily taken up into the edible parts of plants.
Jackson pointed to the successful passage of HB-2658, which bans PFAS from food and food serviceware packaging made from plant fibers in Washington state, as one approach to minimizing contamination of compost from PFAS-laden compostable packaging in the future. Macy and his colleague Jen Jackson who leads the Toxics Reduction & Healthy Ecosystems Program at the San Francisco Department of the Environment explained that the city and county are considering using ordinances as a mechanism to approve only compostable packaging without PFAS as appropriate food serviceware packaging for restaurants to distribute.
So, in order to design composting programs with the end use of compost in mind, some programs like Portland may opt not to include compostable packaging as an approved material for collection. For programs like those of Palo Alto, San Francisco, and Seattle that do foresee compostable packaging being a large part of the equation to successfully pull organic material ordinarily destined for landfill into composting systems, it’s critical to ensure that the quality of the finished compost is appropriate for uses like agriculture, engineered soil products, and more.
This all goes to say that, in Murray’s words, “The regeneration of soil is the task of our generation.” And, in order for packaging to positively contribute to this monumental task, we must be increasingly thoughtful and intentional about how its designed, collected, and processed after its use. With most composting programs in the U.S. in relatively early days, compostable packaging manufacturers and municipal programs alike can look to more mature programs like those of Palo Alto, San Francisco, Portland, and Seattle for inspiration and for ideas on how to leapfrog hurdles they’ve experienced along the way. If we know anything, we know that the solution will not be “one size fits all”.