BioCycle February 2007, Vol. 48, No. 2, p. 19
With a history of success, two farmers run composting operations while dealing with the challenges of moisture, odor control and residuals conversion.
UP UNTIL the 1970s, many residents in eastern Massachusetts had “garbage” collection by hog farmers, with a pail by the curb or back door that was emptied every couple of days. Sumner Martinson, Director of Composting for the Massachusetts Department of Environmental Protection (DEP), says growing up in the City of Newton, which had such a program. “As a kid, I always thought it was the city collecting our garbage, but it was pig farmers who were under contract with the city,” he says. “Then in the early 1970s, the city told its residents to stop separating food since there were not enough pig farmers to provide garbage collection any more.”
With the decline of hog farming, all of those residential programs eventually faded away, with remaining hog farms getting their food waste from supermarkets and restaurants. Now, in a throwback to those days, Martinson and the DEP are working with a number of pig farms, as well as other farms, to recycle food waste, primarily from commercial sources. Among them is Rocky Hill Farm, 10 miles north of Boston in Saugus, Massachusetts. Fran Buzun grew up on Rocky Hill Farm, and helped his father with the hogs. “We still keep between 50 and 150 hogs during the summer, and less during winter, when it is easier to compost the food, rather than walk out to the pens, on the ice, and shovel food out to feed the pigs,” he says. As one of the first farms to register with the Massachusetts Department of Food and Agriculture as a composting operation, Rocky Hill Farm and Transport Company has been composting food waste since the 1980s. “We have over 40 acres at the farm, with16 acres permitted for composting, of which 3 acres is an asphalt pad for receiving and composting yard waste and food waste,” he explains.
Currently serving several Whole Foods Market grocery stores, the Boston Conference and Exposition Center, salad companies, and a seafood manufacturer, Buzun, his wife Marianne, 16-year old son Joe, and four other employees, run the farm and composting business. About 15 tons/day of food waste – plus much larger quantities of leaves, grass, brush and stumps from municipalities and landscape contractors – are composted. Material from Whole Foods Markets is delivered in 30 cubic yard, sealed compactors that also contain significant amounts of waxed and soiled cardboard. Whole Foods uses biodegradable film bags (Bio Tuff bag by Heritage) as liners in the containers set up in each participating department. These are emptied into the compactor and composted with the food at Rocky Hill Farm. Several other haulers also deliver waxed corrugated, restaurant waste, and food from commercial sources in Cambridge, Massachusetts.
“Besides the composting employees, we have two full-time truck drivers who pick up brush, leaves, stumps, and pallets in either 60 cy or 100 cy trailers,” says Buzun. “Our drivers also deliver wood chips to power plants in New Hampshire and Maine, and deliver compost and topsoil to our customers.”
COLLECTION AND HAULING
Cambridge recently received a technical assistance grant from DEP to cultivate a commercial organics collection route. “At last count, Save that Stuff, a hauler specializing in collection of recyclable materials in the Boston area, had 25 to 30 accounts in Cambridge that were separating food waste, primarily in toters. It is then collected several times each week in a packer truck, and delivered to Rocky Hill Farm for composting,” explains Martinson.
Through a DEP technical assistance grant to the new Boston Convention and Exhibition Center (BCEC), DEP provided consulting services from JF Connolly & Associates (Hampton, New Hampshire) to set up the program. “There are two different aspects of recycling organics at a large convention center like the BCEC,” explains Connolly. “You have the kitchen component where thousands of meals are prepared, and you also have the conference exhibitors in the conference hall who sometimes generate lots of organic waste, such as the seafood show, or a nursery and garden center exhibition.”
Working with the facility management, and its hauler, Jet-A-Way, a dedicated organic waste compactor was installed. Connolly explains that it was important to the success of the organics recycling program to also engage complementary recycling activities at BCEC, such as for cardboard, film plastics, water bottles, and returnable containers.
“We started with an international seafood conference last spring, and Jet-A-Way diverted about 8-10 tons to the WeCare Environmental composting facility in Marlborough. Since then, due to Rocky Hill Farm being closer to Boston, and lower tip fees, Jet-A-Way has been taking BCEC organics to Rocky Hill Farm, which charges $45/ton,” explains Martinson. “The chef at BCEC had previous experience with recycling in kitchens, and the BCEC facility manager was very good at getting the program going, so we did not have to provide much more than several days of Connolly’s services to establish that program.” DEP and Connolly continue to monitor and expand the program. “Based on one year of success at BCEC, we anticipate adding the Hynes Convention Center to the program since it too is operated by the same Massachusetts authority,” says Connolly. It is anticipated that the Hynes Convention Center material will also go to Rocky Hill Farm.
Martinson reports that DEP has been very pleased with the operation at Rocky Hill Farm, and that there have not been major odor issues: “Fran is very sensitive to what he takes in and how he handles the materials. They found a nice niche for themselves in processing food, and have helped us expand our food waste composting program.”
Back on the farm, Buzun is constantly working to address the challenges of moisture, inorganics contamination, and residual recycling and disposal. One of the changes in operating procedures that appears to be helping with these issues is a switch from using yard waste as bulking agent with the food/cardboard mix to using wood chips. “I found that when I mix leaves with the food I end up with rocks and sticks mixed with the plastic, metal, and other contaminants in my residue,” he explains. “Since that has to go to an expensive incinerator, I try to keep rock, dirt and wood out of the residue, and recycle as much as possible.”
Due to the high cost of disposal, residue is his biggest challenge. He has used employees to manually pick the tailings off his screen so that rock and wood are not going to the incinerator, but that is very costly too. “I would like to see DEP come up with allowable uses for residue that has some amount of plastic and metal in it, such as a clean fill. It is an issue for every composter,” says Buzun.
Recognizing that such DEP policy change regarding residue disposal is not imminent, Buzun is developing his own device that uses a large fan to blow out plastic pieces, and capture them in netting. An inclined conveyor is used to roll out rocks, wood, and other chunks of material. “Not only do I reduce my costs, but I recover wood which is sold for about $20/ton to burn plants,” he explains.
His company collects stumps and yard waste for $6.50-$10 per cubic yard, and grinds the wood. An excavator with a shear cuts up stumps, recovering soil that is used in manufactured topsoil. A WHO tub grinder makes wood chips that are used as the bulking agent for food waste.
Yard waste is composted separately from food waste due to the residue contamination issue. To control leachate from food waste loads, Buzun builds a wood chip pad on which food waste is dumped to absorb leachate. After a day of letting the material drain into the chips, it is shredded, mixed with chips, then added to his windrows. “I don’t like to let the cardboard get too wet because it clogs in the grinder. Then, with a front-end-loader, I thoroughly mix the food with chips, which I find is the key to odor control. The operator has to make sure there are not pockets of food that have not been mixed with chips, and not just bury the food in the windrow,” he advises. “I’ve been dealing with garbage for a long time and you get to know odors. For example, onions, asparagus, and leaves all have their own odor and I have found I can process such materials and not cause odor problems for my neighbors just 500 feet from the composting area.”
Buzun’s other odor control techniques include watching the weather and not turning piles when the atmosphere is wet and heavy, or if the wind is blowing toward the neighbors: “My thermometer is my best friend when it comes to composting, and I turn piles once they hit 140°F. I find that odors dissipate rapidly from piles that have been composted at those temperatures. If weather conditions are not favorable, I may only turn a 50 foot section of windrow instead of the whole pile.”
Another new feature at Rocky Hill Farm is use of Compostex covers (see sidebar) for finished compost piles. “After the windrows shrink and dry out, I use the excavator to combine two windrows and if I want, I cover the pile so that it stays dry for screening,” Buzun explains. He also covers finished compost so it will be ready when customers need it. For compost product screening, he uses a McCloskey 6-21 trommel with four screen sizes (3/4 inch, 5/8 inch, 9/16 inch, 1/2 inch).
Future plans at Rocky Hill Farm may include an in-vessel system that would provide even more control of the process, but that will mean having to charge more for waste than current tip fees, says Buzun.
BRICK ENDS FARM
Another composting farmer, further north of Boston in Hamilton, Massachusetts, is Peter Britton, President of Brick Ends Farm, Inc. Although not a pig farmer, Britton was also one of the first farms to register with the Massachusetts Department of Food and Agriculture for food waste composting in the 1980s. “Peter Britton goes way back with food waste composting, processing fish waste and sludge from Gloucester that contained fish waste. It’s a very good operation with a history of success,” DEP’s Martinson reports.
While more of a gentlemen’s horse farm, the 130-acre property includes 100 acres under a conservation restriction that is used for horse back riding, and connects to a network of open space and horse trails. As a cooperating farm with Agresource, Inc., an organic waste management company, biosolids are land applied and some fields are leased to area farmers for crop production.
For composting, Britton has a five-acre gravel compost pad, a covered bunker for storage of finished compost and soil products, as well as a maintenance barn. He has three full-time employees, two front-end-loaders, an excavator, and two dump trucks, with 7 and 25 cubic yard capacities. He uses a McCloskey trommel screen with interchangeable drums to manufacture half-inch compost in the summer, and three-quarter-inch compost in the winter that is blended with loam.
His primary food waste customer is Stop & Shop Supermarkets, with eight stores each generating between 5 and 8 tons per month of food waste. With the recent acquisition of Victory Supermarkets by Hannaford Brothers, Britton recently added four Hannaford supermarkets, and is anticipating more will come on line. Horse bedding and leaves also are composted at Brick Ends Farm.
Britton retained the services of JF Connolly & Associates to assist with negotiating contracts with the supermarkets. “I like to think I helped Britton understand the issues that most grocery stores confront in separating food waste, particularly the space limitations in the stores, as well as back-of-the-store operations,” explains Connolly. “I was the interface between Britton as composter, and store management. I continue to track the operations and make recommendations for improving efficiencies to both parties, and we continue to show improvement.”
Unlike Rocky Hill Farm, Brick Ends Farm does not process cardboard, or compactors of food waste. Instead, food waste is collected in 64-gallon toters by a contract hauler, New England Solid Waste Consultants of Rowley, Massachusetts, and then composted at the farm. “I modified a 40 cubic yard rendering box and put a hydraulic lift on the back. New England Solid Waste picks that up on a roll-off truck, and goes to the supermarkets three times a week to collect the food. The lift can dump up to three toters at a time into the truck,” Connolly says.
The supermarkets can elect to use plastic bag liners for the toter, with an elastic band around the top to hold the bag in the container. “Some stores elect to wash the toter at the store. So far, we have not been using biodegradable bags,” he adds. The supermarkets are diverting produce, fish and meat rendering into the toter, along with floral, bakery, and dairy products.
To receive a load of supermarket waste, a rimmed pad is constructed out of horse bedding and leaves. Once the load is dumped onto the pad, it is immediately mixed with a front-end-loader. Britton credits his successful control of odors with prompt mixing, and then incorporation of the mix into the middle of an existing windrow of leaves and horse bedding: “We use a high reach bucket on our loader to scoop open a trench in the top of a windrow, then put the food waste mixture directly into the windrow, and leave it for a month before turning.”
The Brick Ends Farm operations team – Nate Comely, Tom Drinkwater, and Jeff Wheeler – monitor pile temperatures, and track the progress of each windrow. After a load is dumped on the pad, employees inspect the load and manually remove inorganic contaminants such as plastic food containers or wire ties such as those used on broccoli.
The nearest residential neighbor is about a half mile, so process control is very important for odor control. Martinson says he is not aware of any odor complaints associated with the Brick Ends Farm operation, and considers it to be a model facility for the DEP’s food waste composting programs.
“We need more sites and good operators like both Brick Ends Farm and Rocky Hill Farm in order to expand food waste composting in Massachusetts,” sums up Martinson.
Robert Spencer is Contributing Editor and an Environmental Planning Consultant based in Vernon, Vermont.
MORE SITES OPT FOR COVERS
USE of covers at composting sites such as Rocky Hill Farm is increasing because moisture is one of the biggest impediments at composting facilities. Rocky Hill Farm purchased its covers from Steven Wisbaum, owner of Champlain Valley Compost Company, and a distributor of Compostex. “The level of expertise in composting is increasing, and if someone composts outdoors, they realize they need to control moisture,” Wisbaum says. “The people who buy the covers justify the investment since they are in the business of maintaining the quality of their compost products, and they cover it at the most vulnerable points, typically toward the end of the process, and for storage.”
Wisbaum explains that the covers have to be used on a sloped pile since the cover absorbs moisture, which wicks through the material to the bottom edge of the cover where it runs out. “I’ve been using the covers in my own horse and dairy manure compost operation for the past ten years. It can rain 10 inches in a storm, and I do not have to worry about my piles getting wet,” he says.
According to the Compostex web site, the fabric is breathable, so gases from the compost process do not build up, and oxygen can flow through the fabric and into the compost. Wisbaum has found that the covers help reduce odors at his site by keeping piles from getting wet, and retaining higher temperatures in the piles
The covers sell for $1.57 per square yard, so an 18-foot wide by 150-foot long tarp would be about $471, plus shipping. Covers are available in a wide range of sizes (www.cvcompost.com/covers). As for ease of moving the tarps, Wisbaum says that same size tarp only weighs 111 pounds when it is dry, so portions are easily pulled back manually to access the material. “We are also seeing more places using the covers to keep feedstock materials dry prior to composting,” adds Wisbaum.
February 21, 2007 | General
On-Farm Composting Of Boston Area Food Scraps
BioCycle February 2007, Vol. 48, No. 2, p. 19