December 19, 2007 | General

Source Separated Residential Composting In The U.S.

BioCycle December 2007, Vol. 48, No. 12, p. 27
Several counties report more communities joining their existing household organics composting programs, but nationwide, few new initiatives were started in 2007. Part II
Rhodes Yepsen and Nora Goldstein

THE Field of Dreams movie theme, “if you build it they will come,” is definitely à propos to source separated residential organics composting. While conducting this year’s survey, we asked program managers what they think the key ingredients are to offering households the ability to divert more than just yard trimmings at the curb – a practice that is widely adopted in some Canadian provinces and European countries. Having cart-based green waste collection in place definitely helps, but the key ingredient is a reasonably close-by composting facility that is permitted to receive household food waste and soiled paper and cardboard.
With well over 3,500 yard trimmings composting sites in the U.S., several hundred biosolids composting facilities and probably hundreds of farm-based operations, it would seem that more source separated residential organics composting projects would be popping up across the country. If this year’s nationwide survey is any indication, there may be more programs going on that are slipping under our radar. For example, the city of San Fernando, California has had a residential source separated organics composting program for several years, but we just learned about it several weeks ago while talking with Community Recycling & Resource Recovery, Inc., profiled elsewhere in this December issue of BioCycle.
Part I of our nationwide municipal solid waste composting survey ran in November 2007; it focused on mixed MSW composting projects. Part II covers source separated MSW composting, defined as municipal programs targeting household MSW organics beyond yard trimmings (e.g., food waste, food-soiled paper, etc.). All together, BioCycle’s 2007 nationwide survey identified 42 communities and/or counties with source separated residential organics collection programs in the U.S. This is an increase of 12 from BioCycle’s 2006 data (reported in the January 2007 issue). There are 17 programs in California, 1 in Michigan, 7 in Minnesota and 17 in Washington State (all in King County). Table 1 summarizes the 2007 data.

Alameda County, California
Residential single-family waste characterization studies in Alameda County, located across the bay from San Francisco, found that food scraps accounted for 24 percent of the compostable organics stream. Starting in 2002, with funding from StopWaste.Org, several cities in the county began offering curbside collection of food waste and food- soiled paper. (StopWaste.Org is the public agency comprised of the Alameda County Waste Management Authority and the Alameda County Source Reduction and Recycling Board.) Households add these organics to their green waste carts, which are serviced weekly. Now, says Brian Mathews, Senior Program Manager with StopWaste.Org, residential food waste collection is available to 311,000 single-family households in 13 cities. The city of Berkeley is the latest to offer the program. Commingled organics are taken to several different composting facilities that already service the green waste composting programs, including Allied Newby Island in San Jose, Grover Environmental in Vernalis and Z-Best Composting in Gilroy.
Average household participation in the voluntary food waste collection is 25 percent, which equates to about 10,000 tons/year, notes Mathews. Alameda County developed a marketing and media campaign for the program, building on citizens’ current participation in recycling. Robin Plutchok, Program Manager at StopWaste.Org, says the “single essential message of the campaign was, ‘Recycling food scraps is an important way to demonstrate my care for the environment. I wouldn’t want to ‘throw away’ food scraps any more than I would want to ‘throw away’ bottles or cans.’ The tag line of our promotional pieces reflects that message: ‘Food scrap recycling. Make it second nature.'” The campaign included newspaper, radio and cable television ads, bill inserts, bus and subway posters, billboards and a tunnel banner. They featured a “talking” organics cart, e.g., looking at a pizza box and saying, “I call dibs on the box and crust,” or at a banana peel, “Who ya’ calling garbage?”
StopWaste.Org is using its biannual monitoring (cart lid flipping) to measure the effectiveness of the campaign on household participation. Those results aren’t available yet, says Mathews. “We also will be conducting a Waste Characterization Study in 2008, where we will be sampling residential setouts to measure food scrap reduction in the black trash can,” he adds. “Our primary motivation for targeting residential source separated organics is to meet Alameda County’s goal of 75 percent diversion from landfill.”

Arvin, McFarland and San Fernando, California
Community Recycling and Resource Recovery, Inc.’s composting facility in Lamont, California, continues to receive residential source separated organics from the cities of Arvin and McFarland. In 2006, BioCycle reported that Price Environmental Services, a local hauling company, provides 2,900 households in Arvin with 96-gallon green carts to set out green waste and food scraps. McFarland had a similar program, serviced by Pena Disposal.
In San Fernando, Crown Disposal, Inc. – a sister company to Community Recycling – has a contract with the city to provide automated collection of residential source separated organics (as well as trash and recyclables collection). Green cart materials include yard trimmings, wood, food scraps and food-soiled paper. Collection is weekly, on the same day as trash and recycling. “We started working in San Fernando in 2002, and have a diversion rate of over 60 percent,” says Joan Edwards, a consultant to Crown Disposal. “The city won the California Resource Recovery Association’s Outstanding Organics Program Award in 2007 for its accomplishments.”
About 50 restaurants in San Fernando have green carts as well. Some are serviced by the same truck doing residential green cart collection. “Having commercial and residential organics collection on the same route works reasonably well,” notes Edwards. “The one challenge is that many restaurants want a Saturday pick-up, which isn’t offered on the residential routes.” Organics are taken to Community Recycling’s composting facility in Lamont.

San Francisco, California
The City of San Francisco’s ban on plastic grocery store bags went into effect at the end of November. The ban on plastic bags at pharmacy chains will take effect six months later. City enforcement of the ban was starting on December 1st. “The ban applies to supermarkets with over $2 million in annual sales,” says Jack Macy, Commercial Recycling Coordinator with San Francisco’s Department of Environmental Services. “A number of stores are already in compliance, offering paper bags with at least 40 percent postconsumer recycled paper content or certified compostable plastic bags. Plastic bags are not only a litter problem, they are the biggest contaminant in our recycling and composting programs. Jepsen Prairie Organics (Norcal), which takes the bulk of the city’s residential and commercial compostables, pulls out about 70 tons/month of plastic.”
The plastic bag ordinance is among the more recent progressive initiatives with the city and county of San Francisco’s organics diversion program. Its “Fantastic 3” residential program services 150,000 single-family households with weekly recycling, organics and trash collection. Total waste diversion (2005 data) is 67 percent; the city’s goal is 75 percent landfill diversion by 2010, with zero waste to landfills or incinerators by 2020. “Combined, our commercial and residential organics diversion to composting is close to 350 tons/day,” says Macy. “That is due primarily to growth of commercial organics diversion, with about 2,500 businesses participating in the program.”
Despite years of outreach and education with the Fantastic 3 program, household participation in terms of source separated organics has flattened out, especially for food scrap setouts. “We don’t have full participation yet,” says Kevin Drew, the city’s Residential and Special Projects Recycling Coordinator. “We believe many households don’t use it for food scraps because of the ‘ick’ factor.” A pilot program was conducted this past spring in certain neighborhoods to evaluate the best methods of outreach to households to build participation rates. Over 10,000 households received some form of outreach; five neighborhoods received a kitchen pail and compostable bags, while two only received outreach materials. The outreach literature was written in both Chinese and English. In four of the neighborhoods, volunteers and city staff went door-to-door to drop off the pails and/or literature. In three neighborhoods, Norcal (the city’s contractor) dropped off the items. “Volunteers and staff asked residents if they currently put food and/or yard waste into their green carts,” adds Drew. “They also asked if they would pledge to increase their food composting participation, i.e., make a commitment to the program.”
Results of the outreach are being compiled and will be reported in a future issue of BioCycle. Macy notes that ultimately, San Francisco may opt for mandatory participation in its recycling and composting programs. “We also are thinking about every other week trash collection,” he says. “We believe that, combined with the mandatory requirement, would really boost participation.” Another development unfolding with the city’s organics program is Norcal Waste’s interest in anaerobic digestion of the food waste stream. Norcal has been running trials for several years with the East Bay Municipal Utility District in Oakland. Slurried food waste has been added to the wastewater treatment plant’s anaerobic digester. Results of a pilot program will be covered in the January 2008 issue of BioCycle.

Mackinac Island, Michigan
Mackinac Island, a historical community that prohibits the use of motor vehicles, has not changed the way it processes residential source separated organics. Bruce Zimmerman, Director of Public Works on Mackinac Island, notes that, “The hardest part is education.” The island attracts upwards of 15,000 visitors a day in peak tourist season, and ensuring clean loads of food scraps involves clear communication with residents. Materials are primarily collected and transported with a horse-drawn trailer. Zimmerman says that the program is quite successful, with organics diversion at 36 percent. Add recyclables to the equation, and the diversion rate moves up to 55 percent. All of the 900-1,000 cy/year of finished compost produced is sold on the island, to both residents and businesses.

Hennepin County, Minnesota
Residential organics collection is expanding in Hennepin County, going beyond citywide service in the city of Wayzata (which added food waste and soiled paper to its curbside program in the spring of 2005). Additional cities to adopt curbside organics collection in 2007 are Minnetonka, Orono and Loretto. Organics are also collected at a growing number of schools and businesses (currently 8 school districts totaling 41 schools). All told, from residential, commercial and school collection, 750 tons of organics were collected in 2007. Of that, approximately 125 to 150 tons were residential, says John Jaimez, with the Hennepin County Department of Environmental Services.
Currently, 1,800 households in the county have organics collection. There are plans to add two more cities in the first half of 2008 – Medina (1,600 households) and the Linden Hills neighborhood of Minneapolis (4,500 households). “The two new pilot programs will run for one to two years, and will bring the number of households up to almost 8,000,” says Jaimez. The residential programs currently in Hennepin are for food waste and soiled paper, but the Minneapolis pilot intends on cocollecting those materials with yard trimmings, which should improve collection efficiency.
Most separated organics collected are sent to the Resource Recovery Technologies (RRT) composting facility in Empire Township, which grinds the material with yard trimmings and processes them in enclosed, aerated bags manufactured by Versa Corporation. Judy Purman, who works for RRT through The Purman Group, LLC, says that the facility accepts 50 to 55 tons/month of source separated organics. Since March 2007, RRT has only accepted biodegradable bags certified by the Biodegradable Products Institute (BPI). The facility has a 99 percent rate of contaminant removal.
Hennepin County provides grant money for an initial roll of compostable bags to be delivered to a household when the cart is dropped off. If the resident is interested in more than that first roll, they can purchase compostable bags at local retailers. Although bags are required in school and commercial collection, Jaimez didn’t want that to be part of the residential program. “Personally, I did not want the city [of Wayzata] to purchase and provide compostable bags for free, because they are expensive,” explains Jaimez. “People would go through them like crazy and drive up the cost of the program.” His view is that food scraps could easily be placed in milk cartons, paper bags or in the cart without a liner. School and commercial programs have been using bags made by BioTuf (Heritage) and Bag-To-Nature.
Hennepin has started sending some residential material to Carver County’s pilot program (see “Commingled Organics At Yard Trimmings Composting Site,” BioCycle September 2007) and is looking to possibly send more in the future. Jaimez notes that it would be a shorter hauling distance (cutting down on transportation costs), and might foster a bit of healthy competition in the composting market. Currently Randy’s Sanitation is the only hauler collecting organics in Hennepin, offering various money saving promotions. For example, if residents are able to reduce the size of their cart or switch to every other week collection due to organics service, the whole package is cheaper. “Randy is the one hauler to take the risks to make this work, coming up with creative models to make it affordable for households and easy for cities to promote,” remarks Jaimez. “They deserve a lot of credit.” The County provides grant money to any hauler interested in organics, a $25 reimbursement for each household participating. This helps the hauler cover the cost of a new cart, and entices them to reduce the price for residents.

Hutchinson, Minnesota
The City of Hutchinson operates the Creekside Organic Materials Processing Facility, which receives 2,500 of curbside-collected residential organics and 28,000 to 30,000 cy/year of yard trimmings. Operations haven’t changed in the past few years, but the facility is increasing its efficiency by training more staff – there are now 7 full time operators, for a total of 13 employees. Doug Johnson, Compost Site Coordinator, reports that Creekside is looking to expand the capacity of its bagging line, to further its custom bagging and labeling services.
Hutchinson provides compostable bags to residents at no extra cost (part of the garbage fee), delivered quarterly. Creekside has been very pleased with Biocorp and Cortec compostable bags. Participation in residential source separated organics and recycling is at 98 percent. Creekside also composts roughly 10,000 cy/year of dairy manure. Approximately 90 percent of the compost produced is marketed in bags, for a total of 1.1 million bags per year, shipped in the five-state area. Bag sizes range from 10-lbs to 2-cubic foot in size, with prices from 99 cents to $3.50. There are three basic lines – Splendor Grow (economy), Creekside (medium) and Wonder Blend (premium) – with 29 variations among them.
Johnson reports there is a five to seven percent residue rate after compost screening, comprised primarily of metal and plastic. The facility has several key pieces of equipment for its composting operations, including a McCloskey 733 trommel, screening to 3/8-inch minus. It uses a Scarab bag-opening unit with the McCloskey to handle yard waste delivered in black plastic bags. The facility still processes its organics in Green Mountain in-vessel composting containers (with Engineered Compost Systems process control technology), using a Scat turner afterwards to handle the large volumes of material. A portable Bivitec screen from Aggregates Equipment, Inc. is used for final product refinement. The bagging line includes a range of Premier Tech equipment.

Swift County, Minnesota
Started in 1990, the source separated composting program in Swift County still receives about 2,000 tons/year of source separated compostable MSW, according to the Minnesota Pollution Control Agency. Organics are composted in windrows. In 2006, Swift County produced about 1,500 tons of compost; residuals accounted for 146 tons.

Western Lake Superior Sanitary District, Minnesota
Based in Duluth, the Western Lake Superior Sanitary District (WLSSD) encompasses a 530 square mile area in northeastern Minnesota. WLSSD provides curbside collection of yard waste, but not for food scraps, which may be dropped off at five residential drop sites. For 2007, 24 tons of food waste was collected at the five drop-off sites; 297 tons of curbside yard waste was collected. In addition, WLSSD received 1,000 tons of organic feedstock from businesses and institutions (including hospitals, colleges, restaurants, etc.). Biosolids, although generated at the wastewater treatment plant, are not composted. “Wastewater and biosolids are completely separate from our composting program that utilizes only food waste and yard waste as feedstocks,” reports Susan Darley-Hill, WLSSD’s Environmental Program Coordinator.
No changes in operations are reported since last year. Going forward, WLSSD’s 2006 Solid Waste Ordinance requiring large-scale generators of organic waste to source separate starts to take effect in 2008. This ordinance will be applied on a graduated schedule over the next two years, beginning in March, notes Darley-Hill. She explains that WLSSD accepts compostable bags bearing the BPI logo, such as Bag to Nature, Cortec and BioBag. The facility ran into trouble with previous brands that were not certified by BPI, but that has been resolved. All biodegradable products, from bags to cutlery, must be pre-approved by WLSSD, typically following BPI’s guidelines. Compostable bags are provided free by WLSSD at four of the five food waste drop sites (the fifth location is at a hardware store that sells compostable bags). Residents are required to use compostable bags at the food waste drop sites. Yard waste may be placed in curbside containers without a bag, but excess yard trimmings must be placed in approved biodegradable bags. “We have at least one local retailer [The Green Mercantile] that carries a full array of compostable products, including PLA cups, fiber plates, cups and bowls, napkins and biodegradable utensils. There is also at least one large paper products supplier who wholesales approved biodegradable products to nonretail customers,” says Darley-Hill.
The facility generally screens compost to half-inch minus. WLSSD produces an average of 2,500 to 2,700 yards of finished compost per year, most of which is sold as Garden Green® Compost, both bagged and in bulk. Bags are sold at local retailers and can be purchased directly by the public at two WLSSD facilities. Bulk wholesale Garden Green compost is sold on a sliding scale for volumes over 100 yards. Typically, it’s $18/yard for more than five yards, and $20/yard for smaller (self-loaded) quantities.
WLSSD, as a public government entity, is forbidden under state law to provide compost for free. Instead, for noncommercial projects such as schools and municipalities, WLSSD has an in-kind grant program, where compost is provided in exchange for signs with the logo, to be displayed at the site as in-kind advertising. The City of Duluth, for instance, exchanges leaves from the large municipal rose garden for an equivalent amount of finished compost, to be used by the city in highly visible locations.
The facility only accepts source separated organics, and limits the percentage of paper, leading to a very small amount of residuals. There is no tipping fee for separated organics delivered directly to the composting site, as long as the material meets WLSSD’s contamination requirements. “The tipping fee for solid waste at the transfer station, however, is approximately $33 to $37/ton, plus a surcharge, a 17 percent state tax and an additional solid waste management fee based on volume,” explains Darley-Hill.

King County, Washington
King County, with a population of 1.8 million in 37 cities, produces almost one million tons of solid waste per year. Although Seattle is part of King County, it has opted out of the County’s program, and is not included in these statistics. Cedar Grove Composting, a privately owned and operated facility that uses GORE cover system, handles all of King County’s compostables. King County launched its first residential food scrap collection pilot in 2002; the first full-scale program was rolled out in 2004. Food and soiled paper account for nearly 30 percent of the single-family waste stream in the county, making organics collection a priority, says Josh Marx, Senior Planner with the King County Solid Waste Division.
Yard trimmings and food waste service are now available for 62 percent of single-family garbage customers in King County (15 cities plus the unincorporated areas), which amounts to about 177,000 customers. This statistic includes both embedded service for some cities (58 percent of the total), where there is a set cost to residents whether they participate or not, and subscription-based service in other cities (42 percent of the total), where cost depends on services required. Roughly 40 percent of the county is signed up for organics collection. Among food waste participants, approximately 19 pounds out of 44 pounds set out monthly are organics.
Cedar Grove Composting stipulates what compostable bags are allowed to be used, although Biobag and Nat-ur-bag have been promoted by the County. A list of acceptable bags is on, and Cedar Grove sells them through its website as well. Marx notes that many programs start residents off with an introductory kit, which includes one or two boxes of compostable bags, a collection pail and an informational packet for guidance. According to a survey, the bags have encouraged people to recycle more of the potentially putrid foods (macaroni and cheese, fish etc.) than they would have otherwise.

Seattle, Washington
Out of Seattle’s 150,000 households, 103,000 subscribe for yard waste and food waste collection (up from 101,000 last year). Two nonscientific studies were conducted in April and September to measure what percentage of organics set out were food waste. In April, more than 40 percent of the carts contained food waste, and in September, more than 50 percent contained food waste. A survey underway this December will help establish behavioral and motivational issues related to participation.
The City of Seattle plans to provide mandatory food waste service to its remaining 50,000 households in 2009 (although the service would be mandatory, participation would remain optional – food waste has not been banned from garbage). Bret Stav, Senior Planning & Development Specialist for Seattle Public Utilities, notes that a pilot program is being conducted for apartment buildings, with the intention of making the service widely available in 2009. When asked about the keys to a successful residential organics collection program, Stav lists education, convenience and purpose as the three main tenets. “We would have more participation if we collected weekly (convenience); our customers tell us that our educational pieces are helpful for learning what can be placed in the cart; and for purpose, there needs to be a clear understanding of why they should be engaging in the behavior, such as putting less in the landfill, saving money, fighting global warming, etc.,” explains Stav.
At Cedar Grove Composting, which also services the Seattle program, the residential source separated organics from the city and the King County program are noticeable among the yard trimmings, but make up only a small volume of the mix. “We haven’t seen a lot of contamination,” says Jerry Bartlett of Cedar Grove. What he does see, however, are recyclable containers mixed in with the compostable organics. “There seems to be a disconnect, as a lot of what we call contaminants are in fact recyclables – glass and plastic food and beverage containers that are recyclable, as well as some waste paper,” he adds. “The city and county are emphasizing in their educational programs that recyclable food and beverage containers belong in the recyclables bin versus the composting cart.”
THE CITY of Northampton, Massachusetts does not offer curbside trash services, leaving collection to private companies, such as the Pedal People Cooperative, Inc., a human-powered hauler. Using bicycles with trailers attached to the back wheel, Pedal People offers garbage, recycling and organics collection in the towns of Northampton and Florence, with competitive rates. The 11 worker/owners currently service 311 households and 23 small businesses in the area. The city provides a transfer station, which Pedal People uses to drop off trash and recyclables. The station offers dual stream recycling, with paper separated from containers. There is also a scrap metal pile and motor oil is accepted. On average, each household puts out 25 gallons of trash and 25 gallons of recyclables per week, says Ruthy Woodring, a founding member of Pedal People.
In business since 2002, Pedal People started offering organics collection in 2007, and currently has 87 subscribers to the service. Woodring estimates that residents put out one to three gallons of food scraps per week. Most of the organics collected are composted at the Montview Neighborhood Farm, a Community Supported Agriculture (CSA) operation that is also human-powered. The farm is located a few blocks from town, set on three acres of conservation land. The organics that aren’t sent there are delivered to a few backyard compost sites. Woodring explains that the compost won’t be sold, since there is enough interest in it for the farm’s fields and backyard gardens. Pedal People also picks up leaves and grass clippings from residents, which are mixed with the food waste.
The local businesses serviced are primarily small shops, a bakery (which composts its own flour byproducts), gift shops and a cooperative coffee shop. “The bulk of what shops are throwing away is cardboard and packaging,” explains Woodring. A few customers use biodegradable bags, but not enough to notice any problems arising in the compost. As of June 2007, the cooperative contracted with the city to service the 65 public garbage cans downtown, including about 5 recycling cans. Pedal People also offer a grocery delivery service. The city and community members have shown great support of the project, says Woodring. For more information, call (413) 586-8591, or visit

LAST month’s survey article, “Mixed MSW Composting In Transition” (November 2007), incorrectly reported the composting technology utilized by Z-Best Composting in Gilroy, California. The facility has always used Versa Corporation’s enclosed aerated static pile system. Z-Best is considering an expansion at the composting facility, and may transition to Versa’s 14-feet wide by 400-feet long bags. The site currently uses Versa’s 12-feet by 350-feet bags.

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