BioCycle Magazine

San Francisco Takes Residential Organics Collection Full-Scale

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Courtesy of Courtesy of BioCycle Magazine

After two and a half years of conducting a variety of pilot residential curbside organics collection programs that included food and soiled paper, the City and County of San Francisco (referred to hereafter as “the City”) and Sunset Scavenger Company are commencing a citywide rollout of the Fantastic Three Program. This new, innovative program will include the separate collection and composting of residential organics, consisting of all food scraps, soiled paper and yard trimmings, from nearly three-quarters of the city’s residents. This makes San Francisco the first large U.S. city to initiate full-scale residential organics collection that includes food. This program, which also includes commingled recycling collection, is expected to significantly increase diversion and be a centerpiece in bringing the city to California’s mandated 50 percent diversion.

In its recycling endeavors, San Francisco confronts the particular challenge of being a very dense urban city, as well as having a very diverse population. A successful two-stream curbside recycling program (using 12-gallon blue bins for bottles and cans with paper products set out separately) was started in 1989 and rolled out citywide to buildings with five or fewer units. Buildings with six or more units use large centralized recycling bins. By the mid 1990s, curbside setout rates often exceeded 50 percent, with about three-quarters of residents recycling on a regular basis.

Even with this strong participation, residential diversion had started to level off at about 20 percent or 60,000 tons/year. A waste characterization study conducted in 1996 found that residents were still throwing out more than 200,000 tons of trash every year. One-third (or 75,000 tons) of these discards was organic material, most of which (60,000 tons) was food. Overall, food makes up 26 percent of the residential waste stream while yard trimmings amount to only five percent. While most communities can count on a “yard trimmings only” collection program making a big contribution to diversion, it was determined that capturing residential food, along with yard trimmings, was likely to be the key to significantly increasing San Francisco’s ability to meet the state mandate.


In the fall of 1996, the City’s Recycling Program and Sunset Scavenger, a subsidiary of Norcal Waste Systems, started collaborating to develop pilot programs to test the feasibility of collecting a range of residential organics, from yard trimmings only to including all food materials. There was no time limit set on the pilots — in fact those that haven’t yet been converted to the new program are still following the pilots designed for their neighborhoods.

Regional composting facilities were identified that were interested in taking San Francisco’s food residuals. The nearest was the Richmond Sanitary Composting Facility in the city of Richmond, 25 miles across the bay from San Francisco’s transfer station. The facility was available to take vegetative food and compost it with the yard trimmings being received from other communities. Richmond Sanitary already was composting commercial produce from San Francisco wholesalers through another collaboration between the City and Sunset Scavenger.

To fund the residential organics pilot collections, Sunset Scavenger, as one of the City’s permitted haulers, included a proposal in its residential refuse rate application in the fall of 1996. (Sunset services over three-quarters of the city. Another Norcal subsidiary, Golden Gate Disposal & Recycling Company, services the remaining neighborhoods, including downtown.) Residents pay variable rates based on the size and number of trash containers. These rates are regulated by a Rate Board, which acts on the recommendations of the City’s Solid Waste Management Program (which includes the recycling program) and Department of Public Works. The Rate Board approved funding for the residential pilot programs and the new rates went into effect in the spring of 1997.

Pilot collection programs were designed to test and evaluate what mix of organics yielded the most diversion; appropriate collection containers and vehicles; outreach needs; required processing capability and capacity; and the impact of neighborhoods with different demographics. For the initial sets of pilots, the food collected would consist only of vegetative materials (fruit and vegetable scraps, along with coffee grounds and tea bags). Richmond Sanitary was permitted under the state’s new tiered composting regulations in the category that allowed residential vegetative food but not food scraps with meat.

Neighborhoods selected for the collection pilots were considered to be representative of the demographics of significant portions of the city. They were mostly, but not all, single family homes; most were connected houses. The selected routes also had relatively good to high recycling participation and average to high yard trimmings generation, such that if the pilots did not do well then these programs likely would not be suitable for most of the city.


Two curbside residential organics collection pilots were started in 1997 (both with weekly frequency). The first, in July, selected 2,065 households in three different neighborhoods, collecting yard trimmings only. A second pilot with 1,986 households was started in August in similar neighborhoods to the first pilot but collected yard trimmings and fruit and vegetable scraps. Residents were given a green 32 gallon wheeled cart to put compostables out on the curb, with the option of switching to a 64 gallon cart. In addition, participants on the vegetative food route were given a two gallon green kitchen pail and a set of 24 cellophane lined paper bags (Foodcycler brand) to facilitate food separation and keep the pail clean. (Throughout the pilot, the Toter brand carts were used; Toters also are being used for the Fantastic Three rollout.)

Four more pilots were added in 1998. In March, a new route was added to compare biweekly yard trimmings only collection for 485 households also using 32 and 64 gallon carts. Also in March, another weekly yard trimmings and vegetative food scraps route was added but no paper bags were provided because of cost and distribution concerns. Residents were encouraged to use regular paper bags or newspaper to line their pail, if desired.

In October, collection of all food scraps, including meat and food soiled paper, was added to two existing pilot routes — one of the weekly yard trimmings only and one of the yard trimmings and vegetative food scraps. Testing collection of all food scraps was due primarily to new permitted processing capacity for all food material, including animal products, at Norcal’s regional B&J composting facility in Dixon, 65 miles northeast of San Francisco. Sanitary Fill Company, a sister company of Sunset Scavenger, which transfers and hauls the collected San Francisco organics, switched in the summer of 1998 from Richmond Sanitary to B&J. Even though it was a longer haul, having processing within the parent company had financial benefits. The B&J site began processing compostables from San Francisco’s commercial organics collection at about the same time. (An article on B&J will appear in an upcoming issue of BioCycle.)

A total of 6,500 households were selected to participate in the dedicated cart pilots. Outreach, primarily conducted by the City and its contractors, was extensive, including several trilingual pieces — English, Chinese and Spanish (42 percent of San Francisco’s residents do not speak English at home). A detailed brochure was delivered with the carts; labels affixed to the carts and kitchen pails listed acceptable materials and other parameters. Residents also were telephoned within a week of receiving their new collection containers to make sure they got the information and understood the program.

To help evaluate the pilots, the City contracted with Harding Lawson Associates (working with Applied Composting Consulting) to collect and analyze data on participation, including curbside setout rates of yard trimmings versus food, and contamination in the bins. After most pilots had been going for at least several weeks, a four week intensive setout study was conducted by inspecting all containers for participation, contamination and fullness. After that study period, the route driver continued to record overall setout participation for the dedicated organics cart collections.

The data collection results — over a year and a half period — were as follows (all in averages; see Table 1:):

– Weekly yard trimmings only: More than 5 lbs/drive-by were collected. Yard trimmings were 11 percent by weight of the total yard trimmings and trash collected on this route. Weekly setout rate was about 20 percent, and monthly participation was up to 45 percent.

– Biweekly yard trimmings only: More than 13 lbs/drive-by were collected — or 6.5 lbs/week. Yard trimmings were 11 percent of total yard and trash collected. The biweekly setout rate was about 30 percent or 15 percent on a weekly basis. (This neighborhood did have larger yards than the typical weekly collection above.)

– Weekly yard trimmings/vegetative food: More than 6 lbs/drive-by were collected. Organic material comprised more than 15 percent by weight of the organics and trash collected. The weekly setout rate was approximately 22 percent, and monthly participation was up to 55 percent.

– Weekly yard trimmings only, and weekly yard trimming/vegetative food, both adding all food scraps: For the one yard trimmings only route that added all food scraps (including meat and food soiled paper) in October, 1998, diversion increased from only 2.6 pounds to 4.7 lbs/drive-by. The yard trimmings/vegetative food route that added all food scraps had diversion increase from 4.5 to 6.1 lbs/drive-by. Weekly setout rates increased from 13 to more than 17 percent and from 22 to 25 percent, respectively.

Starting in the fall of 1997, the City and Sunset Scavenger also were conducting new pilots for collecting recyclables using dedicated carts. These pilots focused on the existing recyclables, but changed the collection method. One pilot involved giving residents a 32-gallon wheeled cart for all paper material to supplement the blue bin being used for bottles and cans. This alone had a significant impact on increasing pounds of material collected per drive-by to 14.75 pounds or 17 percent. The other pilot involved giving residents a 32-gallon wheeled cart for commingled recyclables. Here, residents were asked to put all their recyclables, both paper and bottles and cans, in the new cart and not to use their old blue bin. The amount of material collected per drive-by for this pilot increased to 17 pounds.


A new series of pilots were designed to further change the concept of the separation between trash and compostables or recyclables by the use of split or dual container carts. Cocollecting two of these material streams together was expected to be more efficient. Starting in March, 1998, targeted households were given 64-gallon wheeled carts, split into two 32-gallon compartments. Three different pilots (all weekly collection) were set up in somewhat similar neighborhoods, with the number of households ranging from 540 to 800 for a total of more than 1,900.

In the first split cart pilot, residents were asked to put trash in one compartment of the split cart, and compostables in the other side (fruit, vegetables and yard trimmings). Recyclables were still set out in the open blue bin. The organic material per drive-by averaged almost seven pounds, and was equivalent to 26 percent of the total organics and trash collected. Weekly setout rate was 50 percent, and monthly participation was about 75 percent.

In the second split cart pilot, residents put trash in one side of their new cart, and commingled recyclables (containers and paper) in the other side. Residents no longer used their blue bin. The average amount of recyclables increased to almost 15 lbs/drive-by an increase of 20 percent over previous totals. Weekly setout rate for recyclables was 80 percent, and monthly participation was about 90 percent.

The third split cart pilot was a compostables/recyclables split. Yard trimmings and fruit and vegetable scraps were set out in one side of the cart, and commingled recyclables (containers and paper) were put in the other side. Residents continued to put out their trash as they had in the past, but did not use their previous recycling blue bin. An average of almost 6 lbs/drive-by of compostables were collected in this program, comprising 13 percent of the garbage picked up. The amount of recyclables averaged almost 17 lbs/ drive-by, an increase of 20 percent over previous collection. In October, 1998, all food scraps and soiled paper were added to this third route. Weekly setout rate was 40 percent, and monthly participation was about 67 percent.

Table 1 summarizes data for the organics pilots conducted in 1997 and 1998. Of these pilots, the compostables (yard trimmings and vegetative food scraps)/trash split cart routes had the highest lbs/setout, weekly and monthly setout rates, and percent of compostables diverted from residential waste.

Contamination levels were not a problem in the pilots and were very low from the beginning, starting usually with six percent or less and dropping over time to less than three percent of the setouts.
 Drivers left tags to remind residents that they should not put certain unacceptable materials in the compostable or recyclable containers. The biggest contaminant in all the pilots has been plastic bags, as it seems hard for some residents to kick the plastic habit. In general, residents who are participating clearly learned quickly what materials were or were not acceptable for the program.

The City conducted a survey in September, 1998 of households in the pilots to gauge resident satisfaction. A large majority of participants (from 65 percent to 95 percent) in all the pilots (except the composting/trash split cart with only 44 percent) preferred their new collection to that of their previous collection. Seventy-seven to 84 percent of the participants in the compostables pilots found greater satisfaction with the new collection system. The most frequent resident complaints were about the size of and handling of the 64-gallon split cart. The pilot route with the most complaints about container size was the organics/trash split — which also has the highest diversion and the least waste, and demographically is an older population. There were very few complaints about separating food (e.g., messiness or smell).


One important component of the pilot programs has been the evaluation of collection vehicles and containers. Sunset Scavenger focused on reducing worker compensation incidents, street litter and associated costs while also striving to increase efficiency in collection of all materials. In San Francisco, the standard refuse vehicle is a conventional rear-loader, with a crew of three, while a two compartment side-loading Lodal, with a crew of one, is used to collect recyclables. Both types of vehicles can accommodate Toters with cart tipping attachments.

Both semi and fully automated side-loading vehicles, with a crew of one, were tested as part of the pilot program. Full automation is clearly the most effective means of reducing worker’s compensation claims and the most efficient with direct curb access, but extensive street parking in most of San Francisco significantly limits the use of fully automated vehicles. A variety of standard side-loaders were tested on the dedicated cart pilot routes. For the split cart pilots, specially designed two compartment compacting vehicles were developed to accommodate the split carts as well as the dedicated carts. These vehicles can be 20 percent more expensive than single chamber ones, given greater maintenance needs. However, the ability to accommodate both split and dedicated carts maximizes vehicle flexibility and efficiency. Additionally, this dual cart flexibility allows the use of the vehicle no matter which cart type is selected for wider implementation. To better tip the split carts, the vehicles were modified by adding a movable hopper divider, movable deflector panels, and strategically placed cart tipper attachments. Limited split hopper capacity (requiring frequent cycling of the compactor) is the most significant limitation on the dual compartment vehicle.

The 32 gallon cart size for collecting organics (as well as for commingled recyclables) was found to be most appropriate, with only a few requests for the larger 64 gallon size. In the pilots, extra compostables that did not fit into the collection cart were set out less than five percent of the time, except for biweekly yard trimmings collection where the larger cart size was often needed. Ultimately, it was determined that using separate dedicated carts was preferable. They provided the most flexibility in size (from 20 to 96 gallons), while split carts were not available in 20 or 32 gallon sizes. Furthermore, both resident and driver satisfaction was lower with the split cart and they required more maintenance.

The ideal collection program needed to be a hybrid of several of these systems, since San Francisco has a range of geography and density.


While all the pilots resulted in increased diversion, the challenge was to find the system that best balanced diversion, resident and driver satisfaction, and cost. Sunset Scavenger recommended to the City, in January, 1999, that a new pilot be commenced that would integrate the best elements of the previous pilots. They analyzed different collection models based on the pilots and proposed utilizing separate containers for the three streams — commingled recyclables, compostables and trash. That would allow for semiautomated collection.

Bob Besso, recycling program manager for Sunset Scavenger, stated his “firm belief that it will be necessary to collect three streams of residential and small business waste in order to meet waste diversion and recycling goals.” Besso projected that cocollection of the recyclable and trash streams and separate collection of the compostables offered the greatest potential for maximizing diversion and efficiency, given the relatively steady flow of recyclables and trash and the seasonal variability of compostables, even with food. This approach would create a new system that would put collecting recyclables and compostables on a more equal footing with remaining trash. They would be equally convenient (because further sorting of recyclables wasn’t necessary); collection of all streams would be weekly and on the same day.

This new pilot program, called “The Fantastic Three,” was rolled out in April, 1999 to 2,800 households for two five day/week collection routes. Residents were provided three new 32-gallon carts — blue for all recyclables (paper and bottles and cans) commingled together; green for all compostables, including yard trimmings, all food scraps and soiled paper; and black for the remaining trash that is neither recyclable nor compostable. Residents also received a two gallon kitchen pail to facilitate separation of kitchen food scraps. They were encouraged to use paper bags or newspaper to wrap their food if desired to keep the bins cleaner.

Outreach strategy and materials were similar to earlier pilots, as that approach was found to be effective and maintained consistency for comparison purposes. This time, however, to further encourage participation, the materials mentioned that residents could save money by separating well and switching to a smaller container for trash.

The Fantastic Three program also included 50 small businesses that were within the residential neighborhood pilot area and had volumes appropriate for Toter collection service. This included five small produce stores or restaurants, which contribute significantly to the quantities of organics and help buffer seasonal variation. The same truck collects from residents and businesses to maximize efficiency. Additional in person outreach and training were provided to the businesses to gain their participation, similar to what is being done for dedicated commercial recycling and composting collection in other areas of the city. Businesses did not receive their blue and green carts unless they agreed to participate in advance.

The area covered by this pilot had been served by a single compartment vehicle for trash with a crew of three, and a two compartment vehicle for recycling with a crew of one. Under the Fantastic Three pilot, two split dual compartment compacting vehicles, each with a crew of one, were used for cocollecting recyclables and trash. A separate dedicated single compartment, side-loading vehicle, with a crew of one, was used to collect the compostables.

From May through December, 1999, an average of almost 46 percent was diverted from landfilling, including the collected compostables and recyclables, increasing the diversion rate by over 90 percent for that neighborhood. Almost two-thirds of this increase was due to the new compostables collection, which contributed about 14 percent overall, while recyclables made up 32 percent overall diversion. On some days, diversion has even exceeded 50 percent.

An average of almost 9 lbs/drive-by of compostables were collected in the pilot, which includes the five small commercial organics generators participating in the program. While an accurate breakout of residential only organics is not available, it is likely that it is 8 lbs/drive-by or more based on evaluating data from the days (Tuesday and Thursday) that have less collected commercial organics. The amount of recyclables averaged almost 30 lbs/drive-by. Weekly compostables setout averaged 40 percent, with at least as many setting out food as yard trimmings. For recyclables, weekly setouts averaged 65 percent. A survey of residents in the program found that 73 percent liked it more than their previous recycling and trash collection service.


Even though the Fantastic Three pilot actually diverted one percent less compostables than the split cart pilot with trash and yard trimming/vegetative food (see Table 1), the City and Sunset Scavenger determined that, overall, there was more worker and customer satisfaction using three separate carts versus the split cart. Furthermore, both parties believe the Fantastic Three program has the best ability to maximize diversion and efficiency. As a result, Sunset Scavenger developed a plan to expand Fantastic Three throughout San Francisco with the support of and in partnership with the City.

Sunset Scavenger has an aggressive plan to roll out the program to more than three-quarters of the city’s households (representing more than 200,000 households). Rollout of new routes is projected to start in February, 2000 and will involve adding a new five day a week route every three weeks initially; after a year, the rate of expansion is projected to increase.

All households in single and multifamily buildings will receive the three carts, as long as there is individual trash billing for their unit. Many two to three or more unit buildings have decided to share the green cart since they share a yard. Each unit still gets its own kitchen pail for food scraps. Larger buildings (usually with six or more units) that do not have individual billing or trash and recycling service receive larger centralized black and blue bins to share, similar to their current citywide service. These large multiunit buildings do not get a green cart for compostables unless they requested one and identify a resident who will be responsible for the bin (additional outreach may be taken to bring these buildings into the program in the future).

As in the pilot program, side-loading split compactor vehicles will be used for cocollecting recyclables and trash — given their relatively consistent volumes — using a 40/60 volume compartment split. Compostables will be collected separately, with single compartment side-loaders, given their seasonal variability in terms of generation. The split vehicles are projected to serve about 1,800 to 2,000 household accounts on average/week (plus apartment buildings and businesses), while the compostables vehicle could serve up to three times as many. This is expected to result in about three split routes for every one compostable route on average. To maximize efficiency, this program entails a complete change in collection routes by Sunset Scavenger.

Sunset has been carefully analyzing the costs required for this new program. “We believe we can do this expanded program at roughly the same cost as continuing the original system, given the efficiencies of cocollection,” says Bob Besso of Sunset Scavenger. “This program will be more expensive initially, because we are purchasing a new fleet of trucks. However, we need to replace our existing fleet. And assuming that eventual containerization of garbage and recycling collection is necessary, costs are likely to balance out over five to ten years.”

This recycling program, along with all other solid waste programs, are funded through variable refuse rates paid by residential and commercial customers. Current costs for residential trash collection, transfer and disposal are more than $150/ton in San Francisco. This does not include the cost to replace the existing fleet of old trash compactor vehicles. Current blue bin curbside recycling net cost is approximately $130/ton, depending on recycling markets. Residents are charged one fee for trash service. There is a lower rate for use of a 20 gallon container — versus the 32 gallon — creating an incentive to increase diversion of recyclables and compostables.

Because Sunset does not have a contract with the City (instead, it has a permit to operate as a hauler and thus gets paid through the rate base), its commitment to a more aggressive diversion program demonstrates a good faith effort that it is helping San Francisco meet the mandated 50 percent goal. In addition, use of semiautomated collection vehicles and carts contributes to improved worker safety and route efficiencies.

The City’s Recycling Program, working with its consultants, projected that 50,000 tons/year of additional residential tonnage could be potentially diverted from landfilling through a citywide recycling and composting collection program such as the Fantastic Three. Approximately 30,000 tons of this additional diversion would be from compostables alone. In its projections, Sunset Scavenger estimated that it could divert 27,000 more tons from residential compostables and almost 8,000 additional tons from small commercial organics generators in a citywide Fantastic Three program. (The City developed a separate figure of 45,000 additional tons for small and large commercial organics expansion citywide.)

The experience with these pilots makes it apparent that collecting residential compostables, including all food, is feasible and supported by residents and has great potential for significant diversion in a cost-effective and sustainable manner. This is an idea whose time has come and which can reap numerous benefits for the city as well as the larger community and environment.

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