Editor’s note: To add to the recycling industry’s dialogue about food-scrap management, we are presenting a lengthy perspective on the issue that was submitted to our publication by the former head of materials recovery programs for New York City.
In this concluding segment, I’ll take a look the critical and evolving role of the materials processor.
Infrastructure in its infancy
The processing of recyclables in the U.S. takes many forms but falls within two basic divisions, either privately or publicly operated. While the infrastructure for processing metals, glass, plastics and paper, both privately and publicly, has evolved significantly over the last 20 to 30 years, the infrastructure for processing post-consumer source-separated food waste is still in its infancy.
In fact, the infrastructure for processing food waste is both conceptually and practically at the same stage traditional recyclables were at when many programs were still run as voluntary drop-offs. This means that the general expectations on the part of those encouraging the institution of food waste source-separation programs is that only clean materials, food waste, without other inorganic materials, will be set out by participants and therefore will require little to no processing and that what is collected can be absorbed easily within an infrastructure, such as traditional yard waste composting operations, or WWTPs, as a new organic feedstock element. Again, this is not the expectation of those experienced in the field of solid waste management but rather more commonly by policy analysts, environmental advocates and elected officials whose approach is frequently more idealistic than practical in nature.
While there are “processors” that can in fact accept source-separated organics as envisioned by those less experienced in solid waste management, those programs are exactly like the traditional drop-off programs at the start of any local recycling effort. For food waste those programs are local community-based volunteer drop-off programs that ask local residents to separate out their food scraps and other acceptable organics and bring them – drop them off – at a local community garden where the food scraps are used by volunteers for producing high-quality compost for use at that garden. In those instances, the resident acts as both the generator, the collector and sometimes the processor as well if a member of the garden’s active volunteers who turn the compost pile.
These types of programs appeal to generators, primarily gardeners and social activists, who see their own food scraps as a resource not to be wasted. Community composting efforts appeal to the select subset of citizens willing to separate out their food scraps, store them between drop-offs, and finally drop the food scraps off locally through their own effort and in accordance with the schedule allowed by the community garden. While these programs can be very successful and should be supported to tap into this extremely enthusiastic and dedicated constituency, drop-off programs are not a model for the jurisdiction-wide capture of food waste. Such programs are an excellent starting point for building public awareness and enthusiasm about source-separating food waste as a practice but alone can only divert from disposal that portion of the solid waste stream of any jurisdiction represented by this core group of enthusiastic pioneers. Ideally, such community-based programs should be instituted, expanded based upon demand and utilized to build support for and change behavior related to food waste, long before any thought is given to attempting curbside collections.
Acceptance of contaminants?
In the leap from community-based food waste source-separated programs to direct curbside household collection, a number of challenges present themselves. Besides the collector’s efficiency and contamination concerns that were discussed in the past installment of this series, there is also the question of the final destination for the material collected. What kind of infrastructure exists to accept what is collected in the condition it is collected? While accepting and processing pure organics is a relatively simple matter both from an operational and regulatory standpoint, accepting any variety of organics with accompanying non-organic contaminants presents a number of challenges.
The greater the variety of non-organic contamination, the greater the challenges and therefore the cost associated with meeting those challenges for the processor. For curbside collected source-separated food waste, greater levels of non-organic contaminants mean more operational and regulatory challenges. Building into food waste source-separation programs the de-contamination of the food waste collected to separate organics from non-organics will add to the overall cost of organics processing, but without it the end product will be unmarketable or unusable.
As many municipalities, counties and states rush forward to institute food waste source-separation programs, the required infrastructure to receive the materials collected is struggling to catch up. The disconnect between the available infrastructure for processing and the needs of the collector is no surprise: In the development of any new diversion program there is always an infrastructure readiness gap between collection and final processing.Similar circumstances accompanied the start and early growth of metal, glass and plastic (MGP) recycling. Over time, it is expected that the infrastructure to compost or otherwise beneficially reuse organic waste will develop and evolve along with the collections that supply the raw feedstock.
Perhaps the greatest challenge that manifests itself at this initial stage of a food waste source-separation recovery program’s development is answering the question of who will pay for the infrastructure needed to process the material. Another question: What should come first – the infrastructure to accept organics or the collections to produce the feedstock needed by that infrastructure?
Although the organization responsible for the collection of the new source-separated material requires, and often seeks to encourage, the growth of an infrastructure that can absorb what is collected and then process the new material, it typically does not want to absorb the full investment cost of that infrastructure’s development, as the ultimate success of the new endeavor remains unknown. Instead of making the investment itself, the collector (especially when the collector is the government) may look to the business community to supply the needed services and infrastructure. Meanwhile, the business community is similarly hesitant to invest substantially in new infrastructure without significant, demonstrated commitment from the collector or supplier of the new raw material.
In the case of any jurisdiction implementing such a program, this creates a challenge, since the collectors – public and private haulers – do not have full control of the quality and quantity of materials collected they are reluctant to make any supply guarantees without sufficient information to do so, and only a sufficient history of collections can provide that missing information.
Inevitably, the phase-in of any new collection program must first struggle through these challenges until sufficient quantity and quality information is available to all parties to allow each party to make the desired commitments with a limited exposure to risk. This period of calibration, wherein the generator is adjusting to new set-out practices, the collector is dealing with less than ideal participation and the processor is challenged with a limited supply of less than pristine feedstock, can easily last for many years, if not decades, and will continue until all three parties better understand the circumstances in which they are operating, or until funding dries up
Returning to the “source” in source separation
Hopefully by now it is clear that the generator’s role in the success or failure of a source-separation program is the central one.The collector and processor play a subordinate role and are utterly dependent upon the generator’s active, accurate and robust compliance for success.
If food waste is harder to efficiently and cost effectively collect and process than other materials stream, it’s worth pondering whether source-separation programs for food waste are the appropriate means to address recovery. Fundamentally, there is little point in asking this question at this moment, since source-separation and collection curbside have already been chosen by many cities and counties as the preferred means to deal with food waste, and the political and financial resources have been aligned behind them.
Perhaps a more basic question to ask is why has this path among others been chosen? Particularly since there are less costly waste prevention programs that could be applied to preventing the present degree of food waste and at a fraction of the cost. In fact, many of the same NGOs that are advocating for the curbside collection of food waste are also actively advocating for food waste prevention and food waste donation programs. One can justify this approach, and advocates do, as being comprehensive, but it fails to consider the consequences of instituting a variety of programs that directly “compete” for the same food waste. If there is any instance where the various federal and state expressed preferred solid waste management hierarchies should actually be applied first, it is to address food waste.
Food waste alone is approximately a fifth of some municipal and county solid waste management streams. Reducing tonnages before the food ever has the opportunity to become waste, while a laudable goal, further reduces the chance of any curbside food collection program being able to achieve anything close to efficient cost per ton collection.
So why chose the route of source-separation? To answer this question it will be useful to invoke the name of an author who to many in the environmental advocacy community has become a pariah: John Tierney, the New York Times reporter and author of the articles “Recycling is Garbage” (June 30, 1996) and most recently “The Reign of Recycling” (Oct. 4, 2015). While one does not need to agree wholeheartedly in the conclusions Mr. Tierney draws in his two articles about recycling in general, one can still appreciate some of the insights he may have tapped into in his writing.
The difficulties of shifting consumption behavior
Chief among those is the insight that many in the environmental advocacy community seek through the call for source-separation programs to have generators pay penance through such activities for their conspicuous consumption. The inherent belief amongst these advocates, conscious or unconscious, is that if generators can be made to suffer through a new and direct relationship with their consumer castoffs, it will ultimately transform this relationship and change their future consumer behavior. While this is a persistent and core belief in the environmental advocacy community, it is not something that has been borne out over the last 30 years of recycling in the U.S.
Instead, what has changed consumers’ behavior most dramatically over that same period of time is technology. Examples include the diminishing presence in the solid waste stream of newspaper and the lightweighting of packaging resulting in the virtual elimination of glass bottles and jars.
In addition, diversion tonnages from food waste programs are not always as significant as required to successfully maintain those same programs, but these results are nonetheless more tangible than the results of waste prevention programs. Waste prevention presents the equivalent of a Zen koan: How do you measure what is no longer there, and to what do you attribute the causality of its absence?
As discussed above, we also must keep in mind the fact that while a curbside source-separation program is maintained all other attempts to reduce or redirect food waste away from disposal will to the extent those efforts are successful, in isolation or in combination, further erode the collection efficiency of curbside service. Many programs already exist for trying to eliminate food waste, such as, donation, garbage disposals, internal disposal units for home and business that remove food waste liquids and create an inert byproduct, backyard composting programs, local community gardens and composters, and particularly in the commercial sector such programs as Lean Path, which help food producers reduce waste and thereby lower operating costs. Similar to the deleterious impact a bottle bill can have upon the efficiency of curbside collections of MGP, such programs can further erode the availability of targeted materials curbside and therefore create even greater challenge for such programs achieving sustainable efficiency.
However, while we all anxiously await the public’s support and engagement with the current round of food waste source-separation programs being introduced around the country, it may be advisable to also be contemplating present and future alternatives to generator-based source-separation programs to deal with excess food waste and what benefits such programs may have over focusing upon source-separation instead.
Apart from the waste prevention programs described above, which should be supported and encouraged, there are some more tangible and practical options that hold great promise for the future for addressing food waste and the other organics remaining in the solid waste management stream.
An answer in mixed-waste processing and AD?
Two options that hold promise alone and in combination are mixed-waste processing and dry anaerobic digestion. I will focus on these two options rather than some of the waste prevention ones already discussed above, because they are technologies that potentially not only hold practical promise but also address solid waste management on the scale needed by municipalities and counties.
Mixed-waste processing is the sorting of solid waste prior to sending what cannot be captured as a result for any other purpose to incineration or landfilling. Assuming the technology can be advanced sufficiently in the future to allow the mix waste sorting technology to handle the volumes produced daily, the advantages mixed-waste processing has over source-separation is the complete elimination of the generator as a factor in the success or failure of the capture of targeted materials. Placing the emphasis upon capture after set-out, rather than prior to set-out, also eliminates the need for public education about program particulars. A mixed-waste processing designed program allows for the rationalization of program operations to allow for immediate subtle changes to be instituted without disruption to the public or collection program operations, since such changes are made on the back end rather than the front and are invisible to the public.
Designing a program that captures food waste and other organics on the back-end rather than at the source allows the state of processing technology – a constantly evolving factor – to define success rather than the willingness of the public to fully participate. Source-separation programs require the public to be constantly reminded regarding their participatory obligations, and these reminders must go out whenever there are potential changes to the items designated for collection, the collection schedule changes for any reason, or collection operations change with regard to set-out. And when the public is unresponsive to these public education efforts, they must potentially be subject to fines, which no political administration willingly imposes upon their constituents, unless forced to so by circumstances.
The technology that shows promise in combination with mixed-waste processing is the use of dry anaerobic digestion. Unlike wet anaerobic digestion, dry anaerobic digestion is much more tolerant of contaminants found typically both in the materials produced by source-separation programs as well as what would be found in much higher concentrations in MSW. Dry anaerobic digestion is also capable of dealing with one of the main challenges to some existing food waste source-separation programs: yard waste.
Yard waste has been introduced in many food waste source-separation programs in an effort to add “other organics” that will help to fill up collection vehicles. However, yard waste as a material to be processed presents challenges to facilities whose main outlet for the post-processed material is wet anaerobic digestion. Requiring facilities linked with wet anaerobic digestion facilities to either install additional upfront processing equipment or use manual laborers to capture the yard waste portion and link themselves with outlets for the yard waste portion undermines some of the rational for the original source-separation.
While both mixed-waste processing and dry anaerobic digestion are still developing technologically, it is still worth considering both of these as future opportunities for perhaps capturing larger portions of the solid waste stream while unburdening citizens the task of being the front line sorters of solid waste.
I have no doubt, for some of the reasons described above, that the NGOs that play a predominant and somewhat oversized role in the political setting of solid waste management policy and practice will find such speculation misplaced and wrong headed. However, to return to a metaphor used by Tierney, as we pilgrims collectively further progress on the current food waste source-separation journey, we may all have revelations forced upon us, on recycling’s equivalent of the road to Damascus, that cannot be denied. In those cases, practicality may finally win sway over optimistic but misplaced aspirations. At least with regard to food waste source-separation collection programs, such hopes have given birth to the equivalent of faith-based program designs.
Longtime recycling industry professional Robert Lange can be contacted at [email protected].