"Innovations" Case Studies: Food Waste Recovery

General Information

• Overview
• Program Characteristics
• Costs, Economics, and Benefits

Overview

Food discards make up 10 percent by weight of the total municipal waste stream and can be a higher portion of commercial sector wastes. In 1997, of the 21.9 million tons of food waste generated in the United States, only 2.6 percent was recovered.

In California, 16 percent of wastes disposed consist of food. This represents almost 5.6 million tons per year. Restaurants, supermarkets, hotels, schools, produce markets, hospitals, prisons, and wholesalers are all large generators of food. Farmers, renderers, and food banks have long collected food discarded by businesses and institutions.

In the last decade, new initiatives have proven successful in recovering more food and converting it into valuable end uses. Curbside collection of segregated organics is growing in popularity. Most of these programs focus on commercial and institutional sectors, but some are also tapping food recovery from the residential sector.

Many commercial sector programs focus on offering collection of source-separated food discards to the largest food waste generators. Haulers from Southern California to Northern California are expanding such service. A growing number of commercial-scale composting sites are now permitted to handle many types of food discards.

On-site small-scale composting systems at schools and other establishments are also on the rise. These range from in-vessel systems to simple worm bins. Other food recovery options include food donations, processing into animal feed, and rendering. And, of course, more attention could be given to waste prevention, such as educating restaurants to offer smaller portions (light meals or half portions).

One of the biggest challenges in diverting commercial food waste is overcoming the perception that segregating food waste is extra work and a nuisance. Through outreach and technical assistance, operational food recovery programs are overcoming this obstacle.

On the residential side, backyard composting has been the main method of encouraging households in the United States to reduce food waste. However, in many European countries-such as the Netherlands, Austria, Germany, Denmark, and Switzerland-food discards are typically collected at curbside combined with yard trimmings.

These systems are slowly being adopted in North America. Seattle, in King County, Wash.; Lewiston, Maine; Dixon, Calif.; and San Francisco have all piloted such programs. Canadian cities with food waste recycling pilot programs include the Ontario cities of Caledon, Markham, and Kingston, Ontario; and Mission, British Columbia.

Halifax, Nova Scotia, and St. Thomas and Bracebridge, in Ontario, have citywide programs already in place. The City of Hutchinson, Minn., also collects food scraps for recycling. Most if not all of these programs have met with success.

In California, 294 local jurisdictions (56 percent of the total in the state) have existing separate collection programs for residential green materials. Another 48 (9 percent) have planned such programs. Adding food discards to these programs has the potential of significantly increasing diversion without greatly increasing costs.

This model study profiles the food recovery efforts taking place in San Francisco, Berkeley, and Santa Cruz, Calif. Each jurisdiction embraces a unique approach to facilitating food recovery.

San Francisco has the most comprehensive program of any jurisdiction in the state. The city and county solid waste agency has formed partnerships with local food banks, haulers, and end users to divert commercial and residential food waste to beneficial uses. Haulers are committed to providing commercial and residential customers with collection of food discards.

After several years of pilot programs, the city and its hauler are beginning residential food waste collection. With the “Fantastic Three Program,” the city will introduce food waste collection during the next few years. (For more detail on this program, see the CIWMB model study “Curbside Recycling, the Next Generation: A Model for Local Government Recycling and Waste Reduction.”)

To spur commercial sector food recovery, the city contracts with a consultant to assist program development and analysis. The consultant also provides training, monitoring, follow-up, and outreach to food waste generating customers with commercial food collection service (provided by the city’s haulers). The city has also funded indoor sorting containers to assist participants. In addition, the city and county have provided more than $350,000 in grant money to help build the edible food recovery infrastructure.

The City of Berkeley has chosen to provide its commercial and institutional sectors with city collection services for food discards. It may be the only city in California providing a city collection service. The program, still in its pilot phase, has had tremendous success.

Santa Cruz County has taken a more modest approach than San Francisco and Berkeley. The county has used a series of relatively small grants to facilitate food recovery initiatives. One grant funded identification of food waste generators and food waste end users, and the linking of the two. Another grant funded the planning and development of on-site vermicomposting systems at camps, schools, and other establishments.

Other communities are also spearheading food recovery efforts. San Jose is funding two pilot projects to test in-vessel composting of food waste from supermarkets. BFI is implementing one pilot at the Newby Island Landfill using Green Mountain Technology’s in-vessel system. Zanker Road Resource Management is implementing the second pilot at its Z-Best Composting facility using the Ag-Bag system.

The City of San Bernardino operated a pilot program targeting 21 restaurants in May and June 1998. Food recovered from these restaurants diverted 4 to 6 percent of the city’s total municipal solid waste during these months.

The Alameda County Waste Management Authority’s support for the Alameda County Community Food Bank helped the food bank increase distribution of produce from 400,000 pounds to 2 million pounds. Orange County also works with a local food bank to encourage more food donations.

Several other jurisdictions have either operated pilot programs to recover food or are starting a program: the City of Rancho Mirage, West Contra Costa County, Palm Springs, Chula Vista, Ventura County, San Leandro, and Sonoma County.

Community Recycling & Resource Recovery’s project in the Los Angeles area may be the largest food waste diversion project in the world. Grocery waste and waxed cardboard are collected from more than 1,000 grocery stores and mixed and composted with green waste at the company’s Bakersfield composting site. California BioMass provides a similar outlet for food recovery efforts, also in Southern California. It has three composting facilities that accept food discards from Orange, San Bernardino, and Riverside counties.

Many college campuses such as UC Davis and UC Berkeley are using vermicomposting to divert their cafeteria wastes from disposal. A number of elementary schools are also using vermicomposting for their food discards (for example, Laytonville and Sierra Elementary School in El Dorado County). Other campuses, such as San Francisco State, are using in-vessel composting systems. On-site composting, whether high- or low-tech, offers the benefit of avoiding collection costs, which represent the bulk of waste handling costs.

California jurisdictions can build on the experience of these private and public sector initiatives in developing their own food recovery efforts. The potential for expanding food diversion in the state is high, because the state already has a strong composting infrastructure and markets in place to use compost products. Food discards have the added benefit of enhancing the composting process and the quality of compost products.

Table 1: Comparison of Sample In-Vessel Technologies

Source: Applied Compost Consulting Inc., Oakland, California (December 1995).

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Program Characteristics

There is no single strategy for diverting food discards to beneficial uses. Food can be donated to charities, converted into animal feed, rendered into soap or other products, and composted. Food waste can also be avoided through prevention strategies.

Food waste generators can divert their food discards to one or more end uses. Unspoiled food can go to food banks. Local and national food bank programs frequently offer free pickup and provide reusable containers to donors. Liquid fats and solid meat products can be used as raw materials in the rendering industry. Many renderers will provide storage barrels and free pickup service.

Five basic types of approaches are in use: (1) unaerated static pile composting, (2) aerated static pile composting, (3) aerated windrow pile composting, (4) in-vessel composting, and (5) vermicomposting or worm composting. Unaerated static piles are better suited for small operations and generally cannot accommodate meat or grease. Aerated static piles and windrows can handle meat and grease with frequent turning and careful temperature and moisture control.

In-vessel composters are enclosed temperature and moisture-controlled systems. They come in a variety of sizes and have some type of mechanical mixing or aeration system. In-vessel composting can process larger quantities in a relatively small area more quickly than windrow composting and can accommodate animal products. Vermicomposting uses red worms to break down organic materials into a high-value compost (worm castings). It cannot accommodate animal products or grease.

Composting can be done on-site where it is generated (using low or high tech strategies) or done off-site at a commercial composting facility. Vermicomposting and in-vessel systems are gaining popularity for use on-site where food is generated. Table 1 compares some in-vessel technologies.

Establishments that compost on-site will avoid collection costs, which generally represent the bulk of waste handling costs. For on-site recovery, establishments need to have space and devote staff resources to operating and maintaining the composting system. Alternatively they may be able to hire a company to install and oversee on-site composters.

In the commercial sector, the following basic steps can facilitate food recovery:

• Identify large food waste generators. Table 2 lists various food-related industries and the portion of waste they dispose as food.
• Assess the possibility of establishing on-site composting systems (in-vessel systems, windrows, or worm bins). Two main factors need to be considered: available space and staff time to properly operate and maintain the system.
• Identify end users for food discards. These include food banks, renderers, farmers, and composters. Assess the types of materials each can process.
• Work with select end users (especially food banks and renderers) and haulers to provide collection service for segregated food discards. Materials accepted will depend on materials end users can process. The existence of a composting facility permitted to handle all types of food discards will result in the highest diversion and program flexibility. Make the program as easy as possible. Hotels, restaurants, and grocery stores can have high employee turnover, so avoid elaborate material separation requirements.
• Contact food waste generators to promote either on-site recovery of food discards or collection of these.
• Provide technical assistance, rate incentives, and bins to encourage food waste generators to participate. Grants to help offset the costs of on-site composting equipment can help spur this activity.
• Perform ongoing outreach to expand and maintain the program. Emphasize the economic benefits to participating businesses.

Residential programs are different. The most successful pilot and full-scale programs have the following elements:

• Collecting food discards with yard trimmings in a toter at the curbside.
• Allowing residents to set out soiled paper with their food discards.
• Collecting organics weekly. (Some European programs collect organics one week and trash the other, with organics collected weekly during the warmer months. Aerated carts can allow for biweekly collection.) In California, putrescibles are required by code to be collected weekly.
• Providing households with a lidded pail to use in their kitchen for collecting food scraps.
• Encouraging residents to rinse out their toters and pails as needed.
• Allowing residents to line their pails or curbside bins with paper bags or newspaper (if they wish).

Table 2: Food Waste Generators

This data is based on sorting garbage samples from individual businesses in Southern California. Material recycled is not included. Figures may not reflect the composition at a particular business or in a particular area.

Source: Business Group Waste Compositions, Solid Waste Characterization Database, CIWMB, (February 2000).

Allowing Food to Remain Mixed with Other Garbage

Some haulers are allowing food to remain mixed with other garbage to keep costs down and to solicit participation by their customers. To avoid contamination problems, customers need to effectively recycle glass bottles and other recyclables. This option is best suited for establishments such as supermarkets that generate a very high portion of food discards. BFI is practicing this method in San Jose’s pilot project, and Golden Gate Disposal & Recycling in San Francisco has also collected this way.

In the City of San Bernardino’s two-month pilot program, targeted restaurants were not aware they were participating-it was a blind pilot. The city’s commingled recyclables program had been operating for four years. The restaurants were basically generating “clean loads” of food discards as their trash, which the city diverted to composting.

Costs, Economics, and Benefits

Commercial food waste generators may economically benefit the most from diverting their unwanted food to beneficial uses. This is especially true if haulers offer reduced rates for collection of segregated organic materials. By reducing the number of trash pickups, costs tend to go down.

Residential households can also directly save money if they pay their haulers variable rates for trash. While haulers include the cost of organics collection in the rates they charge their customers, from the residential customer perspective, recycling and organics collection come free of charge.

Cities who offer collection services can benefit too. Tip fees at composting facilities are generally cheaper than tip fees at landfills. The challenge is to implement a collection program for organics that does not add to total program costs. One major benefit of diverting food discards set out as trash is cost savings. No investment in new vehicles or other equipment is needed. This option may only work well with establishments that do a good job of recycling glass and other dry recyclables, and with those that mostly discard food.

In residential programs that already have a weekly yard trimmings pickup, adding food can increase diversion without adding significantly to costs. Additional start-up costs may be incurred for kitchen pails and outreach. These costs could be recouped through ongoing savings in disposal fees.

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Last updated: October 26, 2007