When food scrap is buried in a landfill anaerobic bacteria, bacteria that live in places with very little oxygen, break down the food scrap. In situations where oxygen is abundant a very different set of bacteria break down the food scrap. When food scrap is digested by bacteria without oxygen the emissions include large quantities of methane, a greenhouse gas 21 times more potent than carbon dioxide. In addition a variety of sulfur compounds are created in the decay process, These stink, and are responsible for some, but not all, of the odor issues at the Central Landfill. RI Resource Recovery Corporation currently uses a methane recovery system in the landfill, selling the methane to an electric power plant, but the overall efficiency of methane capture is estimated at 50%. An alternative to burying the food scrap and recovering the methane is the building of large scale anaerobic digesters to create and capture methane. These systems are much more efficient than burying and recapturing, dramatically reduce methane emissions and allow the residue to be used for fertilizer or feedstock for aerobic composting.
The promise of composting in R.I.
By almost any indicator the Rhode Island economy is not performing all that well. The indicator I tend to focus on is food security. And in Rhode Island too many kids go hungry. The only way we are really going to reduce childhood hunger and food insecurity is to provide the opportunity for almost every family in Rhode Island to grow more food. The record is clear. Compared to their neighbors in similar straits, families with community garden plots have healthier kids, who are eating more nutritiously.
To increase gardening Rhode Island needs a key ingredient — one that we could produce in abundance if we quit tossing it into the state Central Landfill. Agriculture only thrives with a ready supply of compost and to produce that ready supply Rhode Island should quit tossing food scrap into the landfill and start composting it in backyards, community settings, and commercial scale facilities.
Currently Rhode island tosses away about 250 tons of food scrap a day, half a pound per person a day, 365 days a year. Nearly all of that can and should be turned into compost. Across America and around the world more and more communities are ending the disposal of food scrap and beginning its reuse.
If all of the food scrap was composted or digested under much more controlled conditions, including much of the leaf and yard waste of the Ocean State in the mix, the odor issues would be much reduced and methane emissions nearly eliminated. A huge resource formerly thrown away, would be providing Rhode Island jobs, possibly some green energy, and boost local soil fertility.
After exploring the compost industry in Rhode island for five years I can say people are much more knowledgeable, and that there is much more composting going on than five years ago. Further many people want to further develop the commercial potential of composting and digesting food scrap.
A big obstacle holding back the Ocean State compared to many other places is the very low price of disposal at the Central Landfill. We should note that in one of the few sectors where it appears that Rhode Island has a cost advantage of our neighbors and some of our competitors — the cost of trash disposal — we have a situation in which the low cost increases pollution and causes us to squander a resource that could very much help us overcome poverty and food insecurity. There is a larger lesson in there about economic development but I will leave that for another day.
The tale of how Rhode Island came to have such a low price that it impedes commerce and contributes to food insecurity is just the usual inside baseball and cost-shifting we see so often, but one that we are hoping the legislature will tackle soon. It will take action by the legislature to readjust the economics enough to kick open the door for the compost industry.
The Compost Initiative of the Environment Council of Rhode Island, as a partner with the Rhode Island Food Policy Council, the Resource Recovery Corporation, the Rhode Island Department of Environmental Management and others have more recently been tackling some of the regulatory issues start ups in the industry face. We hope that while maintaining strict environmental and community standards — in other words the neighbors will not have to deal with odor or runoff from the facilities — it should be possible for community-garden-sized operations to develop without having to hire engineers and submit plans. In addition we hope very small commercial operations will have reduced filing fees as long as they demonstrate a clear knowledge of proper composting and have no adverse impact on their neighbors.
Every year Rhode Island has moved closer to a fully developed system to safely recycle the nutrients in food scrap., Maybe this is the year of the breakthrough.