WHAT’S IN, WHAT’S OUT
COLLECTING, PROCESSING AND FINANCING YARD TRIMMINGS PROGRAMS
Survey of 124 communities in Canada and the U.S. provides data on bans, collection, markets and overall operations.

Karen Scoulding and Richard Revel

As part of an evaluation of yard trimmings diversion programs in Canada and the northern United States (above the 38th parallel), 124 municipal solid waste agencies were surveyed of which 93 responded. Cities polled were those with populations over 100,000; a minimum of one community per province or state was contacted to provide geographical balance. What follows is a broad tabular summary of our findings. All measurements are metric and all costs are in Canadian dollars ($1US=$1.57C). Percentages are based on the total number of communities that responded to this survey.

BAG LIMITS, BANS AND DIVERSION PROGRAMS

Residential solid waste diversion programs (excluding yard trimmings diversion) are a priority for most of the surveyed communities. A clear majority (83 percent) of the respondents have implemented four or more programs. Communities collect residential recyclables either through curbside collection, dropoff collection, or both collection strategies. Other promoted diversion initiatives include: household hazardous wastes, tire recycling, oil recycling, plastic recycling, paint exchanges, beverage container depots, and construction/demolition recycling programs. Twenty-five percent of the communities have implemented some form of kitchen scraps diversion. Seventy-four percent of these initiatives take place in communities with populations under 185,000.

Of the communities surveyed, 29 percent have invoked some form of seasonal or year-round residential limits on bags or cans of garbage. Calgary is unique in that it has implemented a temporary limit of five bags or cans per household collection during the fall to ensure that routes are completed on time. Extra bags are left behind for pick up on the next scheduled collection day. Bag and can limits may also be established in conjunction with a volume-based collection system. Both strategies encourage residential recycling, backyard composting and grass cycling.

Survey results indicate that yard trimmings comprise up to 40 percent of the total municipal solid waste stream and up to 53 percent of the residential waste stream. Many of the responses are estimates as not all communities undertake detailed waste audits. “Municipalities must plan for peak demand as yard trimmings volume is largely responsible for spikes in truck and worker requirements,” notes David Griffiths, manager of Calgary, Alberta’s Solid Waste Services Division.

Forty-eight percent of the communities surveyed are covered by yard trimmings bans. Various levels of government can ban yard trimmings from solid waste disposal facilities (e.g. landfills, waste-to-energy plants, and incinerators). At the provincial/state level, Minnesota (1992), Nova Scotia (1996), and South Dakota (1995) have all banned yard trimmings from landfills, while West Virginia (1996) has banned it from all disposal facilities. Wisconsin (1993), on the other hand, bans yard trimmings from landfills, but allows burning for energy recovery. At the county level, the Jefferson County (Kentucky) Waste Management Board (1994) banned leaves and grass from the landfill used by Louisville. At the city level, Augusta (Maine) and Seattle have ordinances. The former mandates that leaves and grass clippings be separated from other trash and placed in a leaf composting area, while the latter prevents yard trimmings from being placed in the garbage.

Ninety-seven percent of surveyed communities offer some form of yard trimmings collection, while 88 percent have a Christmas tree recycling program. Source reduction programs include backyard composting, grass cycling, mulching, and yard trimmings minimization principles, respectively (Table 1). Numerous communities offer incentives for residents to participate in yard trimmings diversion initiatives. For instance, several cities give away compost to residents, while one offers free swim/skate/public transit passes to participants in the Christmas tree recycling program. Other Christmas tree recycling programs offer free wood chips once the trees are processed.

Source reduction incentives include subsidizing backyard composters or selling them at a reduced rate. Calgary distributed 10,000 subsidized backyard composters to residents this June. It plans to offer the program over the next two years. Billings, Brantford, Burlington, Chico, Springfield, Tillsonburg, and the Victoria (B.C.) Capital Regional District all have active backyard composting programs to encourage residential participation. Mulching mower rebates and discounts are provided by Sacramento and Tacoma as incentives.

COLLECTION STRATEGIES

Twenty percent of communities surveyed provide curbside pick up, 14 percent offer dropoff sites, and 62 percent use both collection strategies. Numerous organics are diverted: leaves, Christmas trees, grass, branches, weeds, sod, wood residuals, and tree stumps (Table 2). Some communities collect only one specific material, while others gather a wide variety.

Several communities have size limitations and/or ban certain yard trimmings materials from their program. In many cases, branches have diameter and/or length restrictions. Omaha accepts branches up to five cm in diameter and one meter in length, while Richmond accepts branches up to 15 cm in diameter. These limits generally are imposed with processing equipment capacity and ease of handling in mind. Sod and tree stumps are the most commonly banned yard trimmings materials due to weight constraints and processing limitations. Other bans include branches and grass clippings.

CURBSIDE COLLECTION

Of the surveyed communities, 82 percent have established curbside yard trimmings collection. Most communities initiated their programs during the 1990s, although Sacramento started in 1953 and Madison, Wisconsin in 1980. The programs collect from between 400 and 740,000 households. Public collection (50 percent) is the most common, followed by contracted private (31 percent) and residential subscriptions to private collectors (ten percent).

Curbside collection characteristics vary in a number of ways. Seasonal collection (54 percent of programs) is more popular than year-round (28 percent). The former can be a fall leaf program (October-November) and/or a Christmas tree collection in January. Seasonal and year-round programs may divert yard trimmings on a weekly (48 percent), biweekly (23 percent) or monthly (4 percent) basis. Specific yard trimmings materials also can be collected at different times during the month. For example, in Madison, leaves and grass are collected biweekly and brush monthly. Seasonal programs also can have a dedicated number of pick ups (ten percent) over the program’s running time. For instance, London (Ontario) has six yard trimmings pick ups from March to October and residents receive a garbage and recycling calendar so they know when to set out materials. Another option available is call-in service (two percent); residents of Milwaukee can specifically request collection.

Yard trimmings may (47 percent of respondents) or may not (26 percent) be collected on the same day as refuse. Several communities vary in their approach (seven percent). For instance, the franchise-based system in Portland assigns residents to subscribe directly to one of 44 different haulers who service the city. Each private hauler decides if refuse and yard trimmings collection is on the same day.

To collect yard trimmings, communities often utilize existing public equipment such as rear/side loader compactors, dump trucks, and front-end loaders which can be specifically dedicated to yard trimmings or shared with refuse collection. Markham uses dedicated side loader compactors for yard trimmings collection, while Chicago cocollects clear blue bag yard trimmings and recyclables along with refuse in the same rear loader compactor. Depending on the type of material, specialized equipment such as vacuums and street sweepers may be required.

Set out methods vary greatly among the surveyed communities and the majority use more than one option. The material type is the key factor: Branches require bundles, whereas leaves can be placed in bags/containers or swept loose to the curb. Of the communities surveyed, the most popular methods include: bundles, kraft paper bags, open containers and clear plastic bags (Table 3). Boise, Columbus, and Peterborough all promote the use of bundles, kraft paper bags and open containers. Halifax and Salem utilize only roll-out carts. Less common methods involve biodegradable plastic bags and jute bags. Augusta, Surrey, Portland, and Whitehorse use the former, while Guelph has implemented the latter as one option.

DROPOFF COLLECTION

Seventy-six percent of the communities surveyed have established dropoff collection. The majority of communities developed programs during the 1990s; however, Madison was the first in 1980.

Fifty percent of the surveyed communities have year-round dropoff sites, while 23 percent offer seasonal locations during the peak growing period. Communities with seasonal collection offer more dropoff depots than year-round sites. Bismarck and Calgary have by far the most seasonal dropoff locations with 25 and 27, respectively. Fifty-three percent of the communities that collect yard trimmings have dropoffs with full-time supervision during operating hours to prevent illegal dumping. Nineteen percent do not staff full-time supervisors. When residents bring yard trimmings to these sites, most place the material in piles as opposed to bins. Sixty-one percent of respondents who divert yard trimmings do not accept plastic bags and 12 percent do. Of the 57 communities accepting plastic bags, 19 (33 percent) request that residents debag their own yard trimmings. Brantford, Milwaukee and Seattle all require residents to debag and place materials in bins.

Standard equipment used to transport yard trimmings to the composting facility includes front-end loaders, rear/side loader compactors, roll-off trucks, dump trucks, trailers and vacuums. Eight communities have their dropoff site located at the composting facility, thus requiring no feedstock transfers. Dropoff depots are generally financed through tipping fees, residential property taxes, flat entrance rates, and/or per container charges on a residential utility bill.

COMPOST FACILITY CHARACTERISTICS, END MARKETS

Eighty-six percent of the surveyed communities compost yard trimmings, while 9 percent use them for direct land application. Columbus and Sacramento mulch part of their yard trimmings. Three main options exist for compost facility ownership and operation: 37 percent are public, 33 percent are private, and 14 percent are publicly owned but privately operated. The remaining composting facilities are described as public/private partnerships, cooperatively developed and municipally operated, or a partnership between a private nonprofit foundation and the public.

Windrows are the primary composting method (71 percent), followed by static piles (20 percent), channel composting (two percent) and in-vessel systems (two percent), respectively. Twelve percent of the communities cocompost yard trimmings with other organic feedstocks. Charlottetown and Halifax cocompost with kitchen scraps. Davenport, Fort Wayne, Provo and Rapid City all cocompost with biosolids, while Quebec City cocomposts with manure and pulp and paper residue.

Tipping fees at these composting facilities range from nothing to $78/ton (residential and/or commercial yard trimmings). Annual facility design capacities vary from 2,000 tons to an estimated 200,000 tons, while the minimum quantity processed by a community in 1997 was 232 tons and the maximum was 181,400 tons. The most commonly used equipment at composting facilities include front-end loaders, screens, temperature probes, grinders, windrow turners, chippers and shredders. Other equipment options include debaggers, dump trucks, excavators, manure spreaders, moisture probes and watering trucks. Tipping fees and end product sales play an important role in financing composting facilities. Residential property taxes and utility bills along with end product sales and government grants assist in funding public facilities.

Compost is either sold in bulk, bagged or given away to more than one end market. Landscapers are the primary market (36 percent of communities), followed by municipal use (33 percent) and residential purchases (27 percent). Some communities give compost away to residents (17 percent) as thanks for participating in the yard trimmings program. Other end markets include soil blenders, nurseries, land reclamation, golf courses, landfills and farmers.

PROMOTION AND PUBLIC EDUCATION

By far, the most recognized technique for publicizing yard trimmings diversion programs is through the newspaper (85 percent of communities), followed by radio (44 percent), flyer drops (37 percent), utility bill inserts (35 percent), television (32 percent) and billboards (ten percent). A variety of promotional techniques are utilized by a small number of communities, including community publications, composter sales, kiosks in public locations, phone books, posters and special events (e.g. expositions and trade shows).

Public education tools used by respondents include brochures (80 percent of communities), seminars (57 percent), websites (43 percent), school programs (42 percent), telephone hotlines (42 percent) and demonstration gardens (41 percent). Baltimore, Edmonton, Madison and Seattle have implemented Master Composter programs; Ramsey County and Seattle both have Master Gardener programs.

Karen Scoulding graduated from the Environmental Science Masters program in the Faculty of Environmental Design at the University of Calgary, Alberta, Canada. Richard Revel is a Professor of Environmental Science, who specializes in various aspects of resource management at the university.