September 8th, 2010
If I ran the Compost zoo: Greg Gerritt 9/8/10
Home compost. Many practitioners using a variety of technologies from piles to machines.
Materials that can not be composted at home ( primarily animal products that need high temperatures for composting, something the small piles at home have a hard time achieving or maintaining) would be collected for composting in a centralized facility of some scale that could handle those types of food items, by generating enough heat to break them down. Weekly collection at the municipal level for compostables in all 39 cities and towns. Full scale collection from commercial and industrial sectors. Not all industrial food scrap will be composted as there are other beneficial uses (such as feeding pigs) for some types of food scrap. A big part of what we need is a source separated post consumer collection of food scrap or we never stop the methane escaping from the landfill, a very large scale greenhouse gas pollution.
Collection systems would include food scrap and leaf and yard waste. Households would have counter top collector (many varieties available) and wheeled bin to bring to curb, with or without home composting. Food scrap in compostable bags? Or just loose? Good training materials for all households. Statewide ban on landfilling organics, with specific exceptions if necessary. Possible role for MORPH, or a wheeled collector without the extras that begin the composting process
Community gardens all have their own compost program including some collection from the neighborhood as well as from the gardens/gardeners. Maybe even bicycle based collection systems. Gardens with sufficient capacity may have a small anaerobic system to generate gas for ??? Heating greenhouses??? All gardens and gardeners also integrated into statewide/municipal and commercial collection systems for items that need higher temperature composting .
Commercial and institutions Either develop their own composting facility or participate in a source separated collection system. When appropriate incorporate MORPH into collection systems. Other systems for collection, such as specialized trucks, also a possibility.
Types of facilities:
Some sort of centralized composting facilities will be necessary to handle everything not composted at home or in community gardens/other small scale operations. Centralized facilities will handle compostables from municipal and commercial collection.
Possibilities include large scale windrowing either outdoors such as Earth Care Farm or under covers, indoors such as Bristol Transfer Station facility that composts biosolids (processed sewage) and leaves and yard waste inside a building, in vessel aerobic composting units, and anaerobic digesters that produce methane that can be used to create green energy. All centralized facilities require outdoor space for curing compost after the initial processing, and in the case of anaerobic digesters, the digestate must be put through a full composting regime, though the processing for the digestion process and the digesting does mean that the later steps take place faster than if the material was just stating in the composting process., and the initial volume of material to work with is much reduced, saving some space for the facility.
It will be interesting to see what scale compost businesses are able to develop. How will the large size of a digeester/electricity system, and its need to have about half the food scrap in RI on a daily basis effect what else develops if one is built? Will investment capital be available for smaller and regional facilities or will it be one facility fits RI like the RIRRC facility? RI is a unique place, so it will be interesting to see this aspect. Can we actually eliminate the organic component of what goes into the landfill, revolutionizing collection issues? Maybe even collect trash less frequently while continuing to frequently (weekly) collect compostables.
What scale facilities fit particular neighborhoods? Smell issues seemingly can be minimized, but never eliminated. What scale works for low tech, low impact collection systems in a neighborhood? How do farms and right to farm fit into the development of composting facilities in rural RI? Do dairy farms become composting operations as well for agriculture and energy in their community?
We shall have large quantities of compost , high quality compost excellent for growing food crops, if we succeed in capturing and compost nearly all of the food scrap in RI, all 250 tons a day. That gives us about 25 tons per DAY all year round, 9,000 tons a year of finished compost. Enough to make a big difference in our emerging agricultural sectors including expanding community gardens and start up commercial operations.
All this feeds into community development in a carbon challenged world with economic stagnation intimately connected to depletion of forests, disappearing fisheries, soil erosion, and massive floods. All this flows into a world in which the redevelopment of a strong local food system is going to be a critical component of community resilience. And it begins at composting our food scrap.
The best of all worlds would have perfectly sized facilities integrated into neighborhoods in ways that maximized efficiency, minimized transport, reduced our carbon footprint and provided compost and energy in the community. We are likely to get a variety of compost facilities and practices evolving into the future as we learn more and reduce our carbon footprints.
The new evolution is anaerobic digestion, which gives us the possibility of capturing methane for use while also having the compost to put back on the land to grow more food. Digestion may be economic at community garden size scales with the low tech solutions being tested and implemented now. Even considering the home and community solutions that arise, RI is still going to develop a large scale facility, most likely in the neighborhood of the RIRRC facility in Johnston. This will serve municipal home collection and the commercial sectors, with a focus on source separated organics, but with some sectors being machine processed.
Unless the current slump saps all will to live from RI eventually the economics are going to favor energy production that reduces carbon footprints and increases community resilience. With a resource like food scrap, for which the alternatives are only cheap in the short run, eventually it has to make sense to build a large scale electricity producing digester in RI. As people crunch the numbers around the country it is clear it makes sense , though RI with its strange trash market (artificially low tip fees set by the legislature) will require various people to crunch their own, plugging in the costs of collection, tipping and electricity in RI. EPA has generously offered to help pay for that study. Various businesses will want to crunch their own, but having pretty good numbers, such as the 9000 tons of year of compost at the end, and how much electricity can be produced and bought for what price, makes it easier for communities and entrepreneurs to begin to build solutions and easy to operate systems. Something this good for us has to make dollars and sense.
An integrated large scale central facility would do digestion, electricity production, and finished composting, but it is possible to finish the compost at a remote but nearby location, possibly one closer to markets. I am unsure what any particular digestion/electricity production company would do, but it seems useful to start planning as if someone other than the digester company was going to finish the compost coming out of the digester, possibly bringing in other materials, especially yard waste and leaves, to mix with it. It will take a considerable investment to create a large scale composting facility that took in the digestate from the large digester in Johnston and finished and distributed compost. I am thinking very hard about Rhody Compost, marketing it as a truly community sustaining product coming from your dinner plates to fill your dinner plates, or something like that. I am sure we can figure out how to market it and replace what we bring in from elsewhere.
Investment in a compost facility would include land, permitting, pad creation, turning machinery, loading facilities, trucks, and a marketing plan. Right now we need to bring folks together to figure out what the entity doing the compost could look like if it was to focus on agricultural compost. Then figure out who will do it and how to finance it. One way to reduce risk and early investment is to phase in a composting operation focused on agriculture, with RIRRC using the compost for their purposes with an ever increasing amount of the digestate going to the outside composting facility as its capacity and markets develop.
Given the location and ownership status of Urban Edge Farm, there is at least some logic in considering UEF as a location for a commercial composting operation of some size. In September 2010 a number of RI compost stakeholders will meet there to begin the discussion of what is the right thing to do, and where is the best place. It will be good to have that discussion on the land, and I greatly look forward to that convening in mid September, though I know it is only the start of the discussion.