Design Conference Adds Composting to Agenda

By KARA KAUFMAN/ecoRI News contributor

PROVIDENCE — For the past three years, the student-run conference A Better World By Design has brought together the nation’s top thinkers to tackle global issues through design. This year, for the first time, the conference will showcase another, more local level of sustainability: composting. Between panels ranging from health research to zero energy architecture, conference attendees will compost their food and dining ware on-site. In this way, the conference organizers will create dining environments that produce minimal waste while providing an example for the larger composting movement throughout New England.

Better World organizers plan to illustrate and overcome logistical hurdles facing an industrial composting program in Rhode Island. For instance, Rhode Island has few collection sites large enough to handle the volume of food waste produced by the residents and businesses. According to Greg Gerritt, co-chair of the Green Party of Rhode Island, it will take two years to finish constructing an adequate facility to handle the volume of compostable waste the state creates each year.

Mike Merner of Earth Care Farm in Charlestown runs Rhode Island’s only large-scale composting program. Gerritt adds that, unfortunately, Merner has “limited capacity to expand, so he has not set himself up to take all the food scrap in the state.” Earth Care Farm also lacks capacity to compost plastic ware, including the plastic PLA in the conference’s cups and cutlery. Thus, a Better World By Design will send its food scraps and compostable utensils to a composting facility run by PF Trading in East Freetown, Mass.

A Better World by Design will also provide an example of the potential for increased composting programs at both Brown University and the Rhode Island School of Design (RISD). Currently, Brown ships post-consumer waste to a pig farmer and recycles used cooking oil through Newport Biodiesel. Some of its salad waste is composted at a local apple orchard. However, the university provides no programs for students who buy food off-campus or cook for themselves. A Better World By Design plans to work with Brown dining services to ensure that the packaging of drink containers and food items are recycled or composted, and to provide an example of the potential for composting food waste for on-campus events.

RISD has compost containers, and is searching for farms to take the full volume of its finished compost. A Better World by Design will highlight examples of innovative compost containers like the Mobile Organic Resource Procurement Hub (MORPH) composters.

Organizers are planning the conference as an example of sustainable, zero-waste catering. According to Brett Anders, the conference’s catering and social events coordinator, student volunteers will station themselves near composting bins educating conference attendees about composting and providing visual examples of the decomposition process.

“The people who are coming to this conference are the kinds of people who want to be excited and involved in composting,” Anders asserts. “I hope our composting at Better World will inspire other zero-waste events.”

The conference will also feature food from local farms and caterers, including Narragansett Creamery, Schartner Farms and Hill Orchards. Organizers partnered with Real Time Farms to create an interactive online menu showing exactly what is being served and the source of menu ingredients.

ecoRI News provided consulting on the composting initiative for this year's A Better World By Design Conference.

How to Build Your Own Backyard Composter

Video shot and composter built by Barrington resident Alastair Halliday.

In San Fran, Compost Collection is a Treat

By FRANK CARINI/ecoRI News staff

The Three Muskateers: Compost, Recycling and Trash stand curbside at a San Francisco residence. (Joanna Detz/ecoRI News)SAN FRANCISCO — While Rhode Island continues a sluggish approach to some type of curbside composting initiative, food-waste collection in the City by the Bay is mandatory and has been for nearly two years.

The collection of compost within San Francisco’s city limits, however, has been a common practice since the mid-1990s, thanks to the city’s sustained efforts to promote recycling.

Compost is a mixture of decaying organic matter, such as potato skins, coffee grounds, carrot peelings, apple cores and yard waste, used to improve soil structure and provide nutrients. Unfortunately, most of Rhode Island’s valuable organic material ends up buried in the ever-shrinking Central Landfill in Johnston.

The U.S. Department of Agriculture (USDA) estimates that nearly 26 million tons of food waste annualy ends up rotting in landfills or being burned in incinerators. Food waste that doesn’t end up buried or burned, is often chewed up in garbage disposals, which increases the load on sewage treatment plants, wastes water and keeps even more nutrient-rich food scraps from being used to make dirt.

In fact, less than 2 percent of U.S. food waste is managed through composting, according to the federal agency.

Rhode Island has been grappling with the idea of composting its organic waste for more than three decades. In the meantime, as proponents continue to nurture the political and public will to implement statewide and/or municipal composting programs, the tons of food waste the Ocean State buries annually could be better used to create nutrient-rich soil.

Instead, a valuable resource is squandered.

Buried treasure
“Food scraps are a precious resource we shouldn’t be burying or burning,” said Steven Chiv, the residential zero waste associate for the San Francisco Department of the Environment, which oversees the city’s composting program. “You need to get the maximum usage out of this valuable resource. You need to teach people the value of the food scrap.” 

San Francisco collects about 600 tons of commercial and residential food waste daily, up from about 300 tons before the mandatory ordinance — the first of its kind in any U.S. city — went into effect Oct. 21, 2009. The program allows residents and businesses to compost chicken bones, turkey carcasses, cantaloupe skins, used napkins, milk cartons and other food-soiled paper.

To help San Francisco move closer to its goal of zero waste by 2020, the city’s mandatory recycling and composting ordinance requires residents and businesses to separate their refuse into recyclables (blue bin), compostables (green bin) and trash (black bin). All property owners are required to maintain and pay for adequate waste services, and tenants are encouraged to file a report if their property owner or manager fails to provide compost and recycling services.

Owners and/or managers of apartments, condominiums, restaurants, coffee shops and other businesses are required to maintain the appropriate color-coded bins in convenient locations and to educate tenants, employees and contractors on what materials go in each container.

Three years ago — before composting was mandatory — San Francisco diverted 77 percent of the waste it generated from being frittered away in a landfill, according to Chiv. The 2009 figures are expected later this year, and Chiv believes that percentage will be even higher.

“It was a matter of breaking habits,” Chiv said during a recent interview in the San Francisco Department of the Environment’s office, only a few blocks from City Hall. “Getting people to stop instinctively throwing everything down the trash chute.”

To do that, the Department of the Environment had to create policy to implement a composting program and then it had to win the will of government — something Rhode Island proponents of municipal/state composting have failed to do here.

Waste diversion
The task there was made easier by the fact that in 2007 San Francisco was the first major city to enact a ban that forbid restaurants and city departments from using Styrofoam and other brands of the plastic foam called polystyrene. San Francisco also was the first city in the country to ban plastic bags at large supermarkets and pharmacies.

For the mandatory program to be successful, the Department of the Environment also had to make composting as easy as trash collection — a daunting task considering San Francisco, with a population of 805,235, has people living in single-family homes, duplexes, apartment complexes and skyscrapers. Its diverse population speaks Japanese, Chinese, Spanish, Korean and several other languages, and the northern California city with its world-famous Golden Gate Bridge is a popular tourist destination.

Education and outreach, Chiv said, was and still is the key to compliance. “It’s about cultivating the right message,” he said. “You need to get folks off their standard routine and let them see the impact, if not on the environment, at least on their trash bill.”

Financial incentive was the key to convincing the commercial sector, showing businesses that they could save $200 or more on their monthly waste-hauling bills. There’s also the threat of a $1,000 fine for noncompliance.

Despite not fining any business since the mandatory composting requirement was enacted nearly two years ago, Chiv said the business sector, including restaurants, is at a 90 percent compliance rate — better than the 82 percent for the city’s apartment buildings.

Compostable and recyclable materials are banned from the city’s transfer station, enabling trash collectors to enforce the rule by simply not emptying bins and placing a warning tag on the ones that contain incorrect materials.

In fact, the Department of the Environment estimates that three out of four pieces of “garbage” are actually recyclable, which is why San Francisco helps make composting cost-effective by charging trash companies some $120 a ton to get rid of garbage. In Rhode Island, for comparison, the tipping fee sits at $32 a ton for municipal waste.

The 600 or so tons of biodegradable waste collected daily is trucked to composting facilities about 70 miles north of the city, where bones, citrus, meat and other food “waste” is ground into a uniformed size and eventually used to build back our depleted soil.

State Compost Programs Plow Ahead

By TIM FAULKNER/ecoRI News staff

PROVIDENCE — A food-scrap to compost-collection program is moving ahead on many fronts for Rhode Island.

The Rhode Island Resource Recovery Corporation board of directors recently approved the lease of land at the Central Landfill in Johnston for a 150-ton food digester. Under the agreement, the developer, Orbit Energy Inc., must break ground on the project by the end of the year so that the project is up and running by October 2012.

Orbit Energy, based in North Carolina, also recently reached a power-purchasing agreement with National Grid to buy the electricity generated for the burning of the bio-gas at the digester. The agreement is not expected to be official until the state Public Utilities Commission gives its stamp of approval.

The state Department of Environmental Management must also approve permits for the facility.

The Orbit project is one of some 15 proposal that have touted similar food composting programs for the state in recent years.

The food digester's 150-ton capacity may not be enough to handle the state's entire supply of some 250 tons of daily organic waste. So initiatives are moving ahead in Providence for a local composting program. A meeting this week with Matt Stark and Lyndsey Brickle of the mayor's office and DEM reported that efforts are under way for considering a composting facility run out of land owned by Johnson & Wales University nears its campus on Allens Avenue. As a culinary school Johnson & Wales has been looking for a solution to it vast amount of food waste.

Providence's Department of Public Works is looking at ways to start a pilot program for food scrap pick up at city schools and public housing projects. Private groups, such as one run by Matt Jennings of Farmstead restaurants, are organizing a local food waste collection program with a private waste hauler for other restaurants and grocery stores. 

At a June conference hosted by a Providence sustainable roundtable group, DPW officials from Cambridge, Mass discussed its successful food waste program. At the event, several businesses and schools that ship food waste out of state such as RISD, Brown University, GTech and Blue Cross have expressed interest in finding local solutions for creating compost from food waste.

State Expands Use of Composting Toilets

By TIM FAULKNER/ecoRI News staff

Burlingame State Park in Charlestown features four composting toilets. (Photo courtesy of DEM)Composting toilets have been a fixture in Rhode Island for about 15 years.

The first nature-friendly system was installed during a major renovation of the Miquamicut State Beach pavilion in the 1990s. Today, there are some 20 composting commodes at state parks, beaches and campgrounds. So far, none are being used in state office buildings.

Lisa Lawless, an engineer with the state Department of Environmental Management (DEM), designed the converted system at Misquamicut, which retrofitted a septic system to a composting model.

"The public loves them and our park people, for the most part, think they are great," Lawless said.

The waterless system also is great for the environment, saving 1.6 million gallons of municipal water annually. It also helps eliminate year-round plumbing maintenance and vandalism to pipes, which was common during the off-season. In the summer, wood chips containing a bacteria are added to the collection tanks to speed up decomposition. A venting system keeps the tank aerated. Unlike port-o-potties, the tanks never need emptying. One slight drawback, Lawless said, is that the tanks require weekly raking during the summer and some items like cell phones and bottles require removal.

Newer "trailhead" units are replacing old toilets and port-o-potties around the state. These self-contained stations also don't need emptying or even raking like the one in Misquamicut. Several are vented with solar-powered fans and can be moved if needed. They cost up to $53,000 apiece, which is largely funded through grants, Lawless said.

"They are completely self-contained, they don't need any water or put out any pollutants," she said.

Lawless also helped set the state standards for installing commercial and residential composting toilets. She knows of one residential system so far — at the Clingstone House outside Newport Harbor.

Get your own composting toilet
There are several types of composting toilets, such as the bulky, self-contained units that house a collection chamber within the toilet. Others, like the one's preferred by DEM, divert the waste to a central tank built under the floor or in a basement.

Both work well with little or no water. The central collections models are best for bathrooms with a large number of users or at homes or commercial buildings that want a more substantial system.

"As long as the architecture can accommodate it we can put it in," said Lisa Truchon of Clivus New England, the designer and builder of DEM's composting toilets. The North Andover, Mass.-based business also has installed sustainable systems at McDonald's restaurants, as well as the public library in Little Compton.

In addition to Misquamicut State Beach, here's where you can find DEM composting toilets in Rhode Island:

Arcadia Managment Area, Hope Valley, 2
Burlingame State Park, Charlestown, 4
Beavertail State Park, Jamestown, 5
East Beach, Charlestown, 4
Pulaski State Park, Chepachet, 1
Little Compton Public Library, 1
George Washington Campground, Chepachet, 1
East Matunuck State Beach, South Kingstown, under construction
Division of Forestry check stations, 3

Keep It Simple When Backyard Composting

Earle Perkins, a certified University of Rhode Island master composter, shares tips on kick-starting a compost pile for the spring. From his home in Wakefield, Perkins shows how simple things such as water, leaves and a good garden tool are all that’s needed to invigorate the process for creating rich and healthful compost. (Video shot by Tim Faulkner/ecoRI News staff)

Compost Facility Closer to Reality

By TIM FAULKNER/ecoRI News staff

PROVIDENCE — There was near universal support for a comprehensive food-waste-to-compost program during Tuesday’s compost conference at the Rhode Island School of Design. And there was more than just talk about making it a reality, as a large-scale compost facility could be under construction in Rhode Island by the end of the year.

From the Worm Ladies of Charlestown to Waste Management officials to local politicians, nearly all segments of the public and private sectors offered their perspective and support for recycling food waste.

Mayor Angel Taveras said, regardless of the city’s financial mess, “This is the time to invest in things like compost.” He didn’t stick around long enough to give details, but did suggest creating “pilot sites.” “I want you to hold us accountable because we’re going to make it happen," he said.

Interestingly, the city dismissed its top environmental and recycling manager last week, reportedly due to budget cuts. Prior to the start of the conference, Taveras declined to speak to the specifics of cutting the job held by Daisy Diaz, who helped usher in savings well beyond her salary. But Tavares did say to “stay tuned” about the hiring of an energy and sustainability manager for the city.

Despite all the interest in composting, the biggest hurdle to building a centralized compost processing facility is the low cost of simply throwing food in the Central Landfill in Johnston.

Cities such as San Francisco and Seattle make composting cost-effective by charging trash companies some $120 a ton to get rid of garbage. In Rhode Island, however, the “tipping fee” sits at $32 a ton for municipal waste.

“It’s a disincentive; it’s easy to throw (food waste) out,” said Mike O’Connell, director of the Rhode Island Resource Recovery Corporation (RIRRC), which runs the state landfill. However, he also called the low tipping fees “a good thing” and “a two-edged sword.”  Part of the mission of RIRRC, he noted, is to keep its revenue and expenses as low as possible.

Christine Beling of the Environmental Protection Agency's Boston office, said Rhode Island only diverts 2 percent of its organic waste from its rubbish and is well behind other New England states, especially Massachusetts and Vermont, in composting. “Rhode Island is not really in a good place when it comes to infrastructure (for large-scale composting)," she said.

Orbit Energy Inc. spokesman Reese Howle said his company is moving ahead with its plans to build a 150-ton anaerobic food digester in Johnston. The North Carolina-based company hopes to break ground by the end of the year.

O’Connell said his agency is backing Orbit’s bid to build a self-contained, anaerobic food digester near the landfill. “We think this is going to be a winner for us," he said. "This is going to be the one.”

The landfill will run out of room in about 24 years, O’Connell said, but he hopes to extend its life by diverting half of its 150 tons of daily organic waste intake to a compost program, like the one Orbit has proposed. “The raw materials are there and we’re looking for a partner," O'Connell said.

Mike Merner, founder of the 32-year-old Earth Care Farm in Charlestown, offered a more existential approach to recycling food waste. “I’m in it for the long-term sustainability of the Earth," he said. Regardless of economic conditions, Merner said, his farm can’t keep up with the demand for its high-quality compost. His solution to this composting dilemma would consist of a mix of farm-based and municipally run facilities around the state. “It’s our birthright to compost,” he said, holding a pail of rich, dark compost.

Conference organizer Greg Gerritt said Rhode Island, with its dense population, expanse of schools and large hospitality industry, is primed for a compost facility. As a first step, he favors the construction a food digester to cut into the state’s 500,000 pounds of daily organic waste while also reducing pollution, increasing local farming and creating jobs. But, he explained, any action is better than just talking about the food-waste issue.

“What you do when you leave here is much more important than what you learned today,” he said.

Benefits of Composting Builds Growing Demand

By GREG GERRITT/ecoRI News contributor

San Francisco residents are required to have three bins ready for pickup: trash, recycling and compost.More and more communities are composting more and more materials every day. New collection and composting programs are springing up all over — from Toronto to State College, Pa., to San Francisco.

Massachusetts also has a number of composting operations. Nantucket has mandated composting for more than a decade, ever since the island’s landfill started running out of space.

In Cambridge, for example, the city ran a pilot program in 2008 to collect food scraps from residents at two recycling drop-off centers, and 60 city businesses and institutions compost their food waste through a curbside collection program funded by a grant from the Massachusetts Department of Environmental Protection (DEP). Also, through another DEP program, about 200 supermarkets and groceries across the state compost roughly 27,000 tons of food waste annually.

Nationwide, however, San Francisco and Seattle are the only major U.S. cities that require residential organics collection, according to BioCycle, although more than 90 cities and towns offer some type of food-waste collection.

In San Francisco, nearly 500 tons of compostable material — mostly food scraps — is collected daily from at least 225,000 of the city’s 340,000 or so households, according to Robert Reed of Norcal Waste Systems. So more than two-thirds of all households in San Francisco have access to a compost collection service.

The San Francisco Department of the Environment estimates there are between 4,000 and 5,000 restaurants, coffee shops and other food-related businesses in the city. By the department’s count about 75 percent of restaurants participate in the city’s compost collection program.

Of the city’s 8,547 apartment buildings with six or more units, 52 percent (4,419) of them participate in San Francisco’s compost collection program, according to Reed. This is the largest group of apartment buildings in North America to participate in a compost collection program, said Reed, noting that the number of apartment buildings participating in the program has doubled during the past six months.

In Durham, Ontario, which lies east of Toronto and is home to more than half a million people, residents separate food waste for weekly curbside collection.

In Europe, where energy costs and tipping fees are high and environmental standards stricter than here, there are hundreds of anaerobic digesters. In the United States, however, most digesters are on farms for manure management or at sewage treatment plants. In fact, about 200 sewage treatment plants in the United States currently anaerobically digest sewage sludge. Some of these operations, including one in Berkeley, Calif., are now taking in food scrap to increase gas production.

Elsewhere, some communities have started collecting compostables at drop-off locations. ecoRI News, for example, collects compost at the Wednesday (4-7 p.m.) and Saturday (10 a.m.-1 p.m.) Wintertime Farmers’ Markets at Hope Artiste Village in Pawtucket. The nonprofit environmental group collects about 150 pounds of compost weekly, which it gives to local farms.

Other communities have started with residential pick-up services, including bicycle trailer collection systems like the one run by Than Wood in Providence. Some places start with commercial customers, especially food-related businesses, where composting can provide substantial benefits.

Brown University, the University of Rhode Island and the Rhode Island School of Design all have composting initiatives moving forward on campus.

Composting fits well with the local and healthy food movements, and in fact if Rhode Island is to continue to grow its re-emerging agriculture, it’s going to be critical to recycle the nutrients now being landfilled. Less compost means less soil fertility, less emerging agriculture and less food security.

Statewide Composting: Can it be Done in R.I.?

By GREG GERRITT/ecoRI News contributor

Earth Care Farm in Charlestown regularly composts commercial food scrap and sells it as high-grade compost. (ecoRI News file photo)JOHNSTON — The Central Landfill has only a limited amount of space, and is filling fast. Replacing that capacity will be expensive, so reducing the amount of waste tossed into the state landfill is the best way to extend its life.

Plants need nutrients in order to grow into the food we eat. As fertilizers made from natural gas become more expensive, it seems logical to consider recycling the nutrients in food scraps back into our food growing system.

There is a conjunction of interest in these two issues. Rhode Island would like to reduce what goes into the landfill, and one of the things we toss away in great quantities, food scraps, would provide greater benefits to the community if we recycled it.

In 2009, Rhode Island municipalities generated 514,811 tons of material, according to Krystal Noiseux of the Rhode Island Resource Recovery Corporation (RIRRC). The last waste characterization study completed by RIRRC, in 1990, classified 23.2 percent of the entire stream as “other organics,” including food scraps. More recent data from the Environmental Protection Agency (12.7 percent) and neighboring states such as Connecticut (13.7 percent) and Vermont (21 percent) would make 20 percent a more reasonable R.I. estimate.

Under this 20 percent assumption, 102,962 tons of state municipal waste stream, in 2009, would have been food scraps, and 100 percent of these food scraps went to the landfill as refuse.

Municipalities are charged $32 a ton to dispose of refuse, up to an allotted cap, and an over-the-cap rate of the lower between $75 a ton or the current, lowest commercial contract rate. In fiscal 2010, state municipalities delivered 318,835 tons of refuse at $32 a ton, 13,933 tons at $54 a ton, 9,823 tons at $58 a ton and 146 tons at $75 a ton.

If Rhode Island municipalities had been able to capture 100 percent of the potential 102,962 tons of food scraps through a compost collection system, the total savings on landfill tips fees would have amounted to $3,862,986. At a 75 percent capture rate, this cost savings would have been $3,039,306, and at the more likely 50 percent capture rate, the savings would have been $2,215,594.

Of course, to put a municipal composting system into place, there would be additional costs to provide composting bins for every household, expanded collection services and to pay tip fees at another compost facility.

The state goal for the rate at which municipal materials should be diverted from the landfill is presently 50 percent for each municipality. Diversion rates for municipalities are calculated on the calendar year, but if we assumed the same 102,962 tons of food scraps over the calendar year, keeping these food scraps out of the municipal stream would have also boosted the state average diversion rate from 28.1 percent in 2009, to 48 percent (at 100 percent capture), 43 percent (at 75 percent capture) or, more likely, to 38 percent (at 50 percent capture).

In fiscal 2010, state municipalities delivered 29,548 tons of leaf and yard waste to the Central Landfill and generated another 32,617 tons in 2009 that they either composted at their own municipal sites or sent to another facility. At RIRRC, municipalities are charged nothing to dispose of leaf/yard waste up to their allotted cap, and an over-the-cap rate of $25 a ton.

A new policy allowing for municipalities to gift their excess cap went into effect in fiscal 2010, but 11 municipalities still went over by a total of 9,000 tons. If we assume a municipal composting facility would have kept 100 percent of this overage away from the state landfill through a competitive tip fee, the total municipal savings on RIRRC leaf/yard waste tipping fees in fiscal 2010 would have amounted to $225,000.

This would have made total municipal tip fee savings from organics collection — food scraps and leaf/yard waste — at $4,087,986 for 100 percent capture, $3,264,306 for 75 percent capture, or more likely, $2,440,594 for 50 percent capture.

It’s worth noting, however, that the municipal under-the-cap tip fees of $32 a ton for refuse and nothing for leaf/yard waste have proven to be barriers for private companies looking to develop a composting operation in Rhode Island.

Also, unlike municipal waste, which is obligated to come to the Central Landfill by state law, commercial waste can go here or be brought elsewhere.

Growing practice
Around the country and the world more and more communities are adding up the numbers for the total cost of their trash systems and opting for composting their organic materials. The cost of disposing of food scrap in landfills or incinerators varies. As Noiseux noted, tipping fees in Rhode Island are on the low side, despite the severe lack of long-term disposal capacity and that has probably slowed the development of our compost industry compared to other places.

Even so, it’s likely that communities and businesses throughout the state, in cooperation with RIRRC, will eventually find that the separation and collection of organic compostable materials makes sense once you consider the costs of burying this waste and the benefits of recycling it.

A properly operated compost facility ensures that the gases that create offensive odors are not produced in appreciable quantities. Still, special care must be taken in locating compost facilities. In windrow facilities, food scrap and leaves are shredded, mixed at approximately a one to three ratio, piled in long windrows, and turned every three days or aerated through pipes. The piles reach at least 160 degrees Fahrenheit to kill off pathogens and weed seeds early in the process and eventually transform into a nearly uniform brown mass with an earthy aroma and incredible fertility. Compost can be stored for months before sale without losing its qualities, but not indefinitely.

A facility that could handle all of the collectable food scrap in Rhode Island — mixed with an appropriate amount of brown material such as leaves and/or wood chips — would cover about 9 acres. Such a facility or even a much smaller one would have to adhere to Department of Environmental Management permitting requirements. There are rules for runoff, odor, setbacks, wetlands, etc. A facility would operate on an engineered pad, with a leachate collection and treatment pond, and truck traffic will have to be accounted for.

A site within the perimeter of the RIRRC operations and related businesses seems a logical choice for a large composting facility, while smaller facilities might be created in other favorable locations throughout the state.

Commercial composting facilities require water, sewage, electricity, an engineered pad, proper drainage, a grinder, large equipment for moving and turning compost, space for large equipment to maneuver, and loading docks for compostables being dropped off and finished compost being shipped out.

Built and equipped from scratch, a 2-acre aerobic compost facility capable of handling the commercial food scrap from the food industries — about 60 tons a day — would cost about $500,000 to set up and several hundred thousand dollars a year to operate. It could generate $500,000 or more in annual sales. A 9-acre facility would cost more than $1 million to set up.

Landfill gas
Landfills are the No. 1 source of methane emissions in the United States, and food scraps produce much of that methane. Methane is a potent greenhouse gas, reflecting at least 21 times as much heat energy back to the earth as the same amount of carbon dioxide. Composting and putting the compost back into the food system dramatically reduces the amount of greenhouse gases emitted.

Landfilling food scraps also causes us to lose the soil-building capacity of this material, burying it underground instead of returning to the topsoil to grow more food. One of the fastest-growing industries in Rhode Island is agriculture for local consumption. Not returning all the food scrap to the soil definitely will impede future growth in this industry, as farmers will struggle to sustain their soil fertility.

Collecting organics and composting also would create jobs in the compost industry, in the food industries and possibly in the renewable energy sector.

There are costs in transforming from a landfilled food waste system to a composting one. These costs include developing and implementing the proper separation and collection system, and the development of compost facilities. The usual place to find the money to implement the various aspects of a compost system is in reduced tipping costs. Rhode Island’s low municipal tipping fees mean that model might not work as well here, as there is likely to be little in the way of savings in tipping fees available to offset the expanded collection costs. We may have to look at this issue a bit more broadly to understand our savings.

There are the types of compost facilities needed if we are to capture and compost the majority of compostables created in Rhode Island:
• Home composting, including vermiculture
• Community garden composting
• School composting
• Farm composting
• Commercial composting operations
• Municipal composting operations
• Centralized large-scale composting operation
• Food-scrap fueled anaerobic digester/clean-energy facility
• Sewage treatment plant composting and digesting

Composting begins at home, and thousands of Rhode Islanders currently compost. Community gardens also compost, on a scale not much different than home composting, and most farms compost. Many Rhode Island schools also compost, with elementary, middle and high schools having tumblers in the yard and worms in the classroom, and several state universities/colleges are researching their options and starting to compost food service scrap.

A willingness to compost
Currently, several Rhode Island municipalities compost leaves and yard waste, and the RIRRC composts leaves and yard waste for communities without their own composting facility. Several private companies also compost leaves and yard waste disposed of by landscaping industries.

A few businesses also have the necessary permits that allow them to compost other people’s food scrap in large quantities, but only Earth Care Farm in Charlestown is regularly composting commercial food scrap and selling high-grade compost.

Currently, no Rhode Island municipality collects and composts food scrap, though Bristol has the capacity and willingness to work with potential partners using the facility that composts the town’s sewage sludge.

However, food-scrap collection is the wave of the future and food-scrap-focused digesters are being built, often by businesses that believe there is a profit to be made in the electricity business, with compost an additional value center. Large-scale digesters will only be built with power-purchase agreements in hand from electricity utilities or if a community has a need for the power generated at a digester facility, such as powering a sewage treatment plant.

It has been suggested that with the price of oceanic wind power in Rhode Island coming in so high, digesters working food scrap could come in with cheaper green power that is more reliable. As long as people eat and are processing uneaten food, the digester has fuel. In fact, densely populated places such as Rhode Island have more food scrap per square mile than other places, making the state an efficient place to set up a digester.

The proposed size for a commercially viable anaerobic digester/electricity production facility is one capable of digesting 150 tons of food scrap a day.

When a digester is finished, what is left over is a sludge-like material called digestate.  This digestate can be composted with leaves, creating nutrient-rich compost. Another alternative, one suggested to me by several different people in the digester business, is that the waste heat from the electricity production could be used to dry the digestate, and that dried digestate can be pelletized into commercial nutrient-rich organic fertilizer with some properties similar to compost.

An anaerobic digester and its associated power plants sized to digest 150 tons a day of food scrap would cost in the range of $10 million to $20 million. This can be justified by the selling of electricity or natural gas to the grid. No one will build a freestanding commercially operated anaerobic digester/energy facility unless they have a power purchase agreement in place with an electric utility and can contract for sufficient food scrap.

Electricity generated by burning the methane produced in digesters is more expensive than electricity from old coal-fired power plants, but appears to be significantly less expensive than what some of the oceanic wind power projects say they need to be paid to be profitable.

Compost Feeds the Circle of Life

By GREG GERRITT/ecoRI News contributor

Composting is the breaking down of organic materials such as food scrap, leaves and manure by bacteria in the presence of oxygen, and transforming it into what is essentially the organic and high-nutrient portion of topsoil. Composting recycles the nutrients and organic matter in what we have thrown away so that plants can reabsorb the nutrients and use them to grow.

In a forest, the leaves fall to the ground each year, but they never fill the forest because below the surface of the leaf litter bacteria are turning the leaves back into soil.

The breakdown of organic matter takes place in several steps over the course of time, each step in the breakdown being done by a different mix of bacteria. The speed at which organic matter breaks down and turns to compost varies according to conditions.

Reducing the size of the organic matter to be composted provides more surface area for the bacteria to work and speeds things up. Other factors effecting the speed of composting include the oxygen flow to the compost pile, which can be controlled by either an aeration system or by turning the pile, moisture and temperature. By regulation, and sound composting practice, commercial compost piles have to heat up through bacterial action to more than 160 degrees Fahrenheit for several days or they are not acceptable for agricultural purposes.

Properly managed composting operations can turn food scrap and leaves into finished compost in about eight weeks.

Another approach that is considered to be within the realm of composting is to use worms to process the organic matter. Vermiculture turns food scrap into worm castings that can be directly returned to the soil, working exactly like compost. Mostly practiced at home, there are large-scale vermiculture operations selling compost. Worms can compost all vegetable matter, but there are limits to what they can eat, so to fully capture food scraps, vermiculture must be supplemented with another approach.

It should be noted that there are many compostable items, such as expired dairy products and meats, that can be successfully composted, but require a higher temperature than is usually created in a home compost pile. Therefore home composting on its own will never meet the need for complete organics composting, even for the most ambitious home composters.

Therefore, a complete system must include facilities handling large quantities of compostables collected from the community and businesses and able to compost the hard to compost items.

Anaerobic digestion is the bacterial breakdown of organic matter with no oxygen present, as opposed to the composting process, which is the breakdown of organic matter in the presence of oxygen. The bacteria in the anaerobic process create different gases than the bacteria that work in the presence of oxygen, with methane being the leading end product.

Burying food scrap in a landfill causes it to breakdown without oxygen, creating the smells no one wants to experience and much methane that no one wants in the atmosphere. The Central Landfill collects between 50 percent and 75 percent of the methane produced by food buried in the landfill, with a piped collection system, and it is burned in a turbine to create electricity. The rest eventually escapes into the atmosphere.

If one is actively pursuing anaerobic digestion in a closed system — essentially some kind of vat or chamber with pressure controls to keep out oxygen and keep in the gases — it is possible to capture all of the methane and other gases. This captured gas is then burned in turbines to produce electricity. Another alternative is to clean up the gas and then put it into the commercial gas pipeline system, as methane is the basic component of natural gas. Natural gas is simply the product of anaerobic digestion millions of years ago that remained trapped in the ground or under the sea.