Grasping at compostable straws
Biodegradable/compostable straws are still trash if there’s no composting facility to process them
Like “compostable” chip bags and “natural” claims for trashy food, corporate America’s gushing eco-speak lauding the switch from plastic to compostable sippy tubes may really be grasping at straws. Too often, that greenie glow surrounding biodegradable straws dissipates in a puff of smoke when confronted with the realities of today’s composting infrastructure.
Unless a community segregates its compostable waste and sends it to a modern composting facility, most oh-so-ecologically-correct products are headed for a landfill where they will either generate methane as they biodegrade or break down no better than the plastic they replaced.
And don’t think a landfill gas recovery system makes that disposal any better. Most of the methane generated during anaerobic landfill decomposition escapes before the cell can be capped and the greenhouse gas collection system installed.
The ability to compost the millions of straws U.S. consumers use every day would definitely be a positive step. Unfortunately, there are several things that need to happen before that green glow transmutes into something corporeal.
Compostable straws need infrastructure
Let’s consider an example. One online retailer offers a box of 600 compostable straws weighing 1.8 pounds. At that weight, America’s daily use of 500 million straws (a contested number, but that really doesn’t matter for this exercise) would fill 833,333 of those boxes for a total of 1.5 million pounds or 750 tons per day for composting.
Distributing those used straws equally among the 4,700 composting facilities in the U.S., the total tonnage would add only 319 pounds of additional material to the daily throughput at each operation – less than half a cubic yard. So, at least as a “paper” exercise, processing capacity is not an issue.
But here’s the problem: the vast majority of those facilities can’t accept many of the biodegradable and compostable products being touted in the marketplace because their composting processes aren’t up to the task. And that includes PLA/bioresin straws. They can’t break the material down fast enough for the system’s designed throughput rate. As a result, the partially decomposed “compostable” shows up as contamination in the finished compost.
Additional screenings might get rid of some of that contamination, but extra handling ups the cost and could negatively impact operating expenses and profitability.
The low temperatures of most home composting bins don’t have a prayer of breaking down these types of biodegradable products, either. Tough-to-degrade materials require modern, high-rate composting technologies to effect rapid biodegradation.
Typically, advanced facilities process indoors and/or in-vessel. They rely on automated aeration and temperature feedback systems. This tight environmental control brings the composting mass up to temperature quickly and keeps it in composting’s Goldilocks Zone, eliminating the hot-cold cycling of more primitive composting methods.
Provided all other environmental factors (moisture, C:N ratios, etc.) are right, this level of control accelerates the process by encouraging the proliferation of composting microbes and giving them more actual feeding time within a shorter processing window.
More microbes, plus more feeding time, leads to the rapid breakdown of complex compounds (like the plant-based polymers that make up compostable plastic) without extending the time required for primary processing.
The refuse of any given society reflects that society’s level of sophistication and technological achievement. If First World consumers and their cities are sincere in the desire to meet zero waste targets, then composting needs to modernize to take on the more complex plant- and animal-based wastes engineered by those advanced populations.
If not, then consumers will need to assign many “biodegradable” and “compostable” labels to the realm of irrelevance. Without a strategy to separate biodegradables from other trash and a composting facility that can process the tough stuff, it really isn’t compostable in that community.
Composting co-mingled trash, then attempting to screen out contaminants at the end of the process, has proved to be unworkable. At best, contamination in the finished product is simply too high to give the resulting compost any market value. At its worst, the contaminated compost is peppered with glass shards, unsafe for use as anything but boiler fuel or landfill cover.
Therefore, walking hand-in-hand with advanced composting is the need for a collection system that separates biodegradable material from wastes that would contaminate the stream – before that material arrives at the composting facility.
Fortunately, several opportunities exist between zero collection and 100 percent collection for urban organics:
- Waste streams from food and fiber production, processing, and manufacturing, where generators discharge clean, organic waste by the roll-off box or tractor-trailer load, represent the low-hanging fruit for composting. With waste capture systems already in place, rerouting those truckloads to composting instead of disposal is the only effort required. Indoor composting operations equipped with biofiltration systems can be sited closer to populated areas than landfills, targeting sites near heavy industry and other locations with appropriate zoning and access routes.
- In the absence of mandates, third-party collection has proven to be a successful strategy for mid-size food waste generators like universities, restaurants, and grocery stores who fill carts and bins instead of tractor-trailer rigs. These collection companies then transport to a local composting facility. Eco-driven start-ups have also pioneered voluntary food waste collection at the residential level in areas where composting facilities exist, but city composting mandates do not.
- School systems, apartment complexes, shopping malls, business parks – any owner/management entity with the authority to implement and enforce policies for a group can initiate a source-separation strategy for biodegradables and compostables. Some collectives may generate enough volume for their own in-vessel composting unit or direct service by a traditional hauler. Others will need to contract with a company providing cart/bin collection service or plan to self-haul to the composting operation. For generators intending to self-haul, know that minimum load requirements may apply, as well as policies related to the hauling vehicle, driver licensing and safety equipment. (See an example of the McGill policy here.) Reach out to the intended composting facility early in the planning process.
- Commercial and residential curbside collection represents the greatest challenge to the recycling of biodegradable materials. While central authorities for schools, business complexes, and the like may need to educate a handful to a few thousand waste generation units, cities may need to develop outreach and enforcement programs impacting millions of people. But it can and has been done. The difference between those who have and those who have not is lack of intention, not missing infrastructure, tight budgets or any of the other “reasons” used to excuse complacency.
Composting can become a reality without a capital investment on the part of the host community. Just set the stage and invite the players.
The bigger companies in the composting industry, those with proven technologies and track records, will look favorably on building, owning, and financing new facilities when appropriate sites are offered and diversion mandates promise high volumes through their gates.
Laws and policy mandates are the catalysts that build both composting and collection infrastructure. While progress can be made in their absence, forward motion is much faster and tacking most favorable when propelled by regulations.
Finally, if composting options for paper straws or compostable cups or any other biodegradable waste is needed in the region, call someone – a councilman, county commissioner, state legislator, or congressional aide. Ask like-minded friends and colleagues to do the same. Get the issue on the local radar. Make composting happen.