There is a debate around the table regarding strategies for the collection of recyclables and greenwaste from the curb. At issue is reaching that strategic balance between efficiency and diversion, material quality and cost.

By Lynn Merrill

On one side of the table are the collection managers. Their job is to maximize the efficiency of the collection operation while minimizing the cost per stop and therefore the rate paid by their customers. Their goal is to get the materials picked up quickly, safely, and with the least disturbance to the customers’ lifestyle. As any collection manager knows, miss a customer on a route and they might teach you some new words.

On the other side of the table are the recycling managers. Their challenge is to maximize the type and quantity of materials that are diverted from the landfill and to ensure that the quality of the material is such as to maximize the marketability of those materials. Their goal is to get people to reduce the amount of waste they generate and to divert as much of the waste generated towards markets. They strive to change customers’ lifestyles in order to minimize waste and maximize diversion. They know that at one end of the spectrum are those customers who demand recycling opportunities at any cost while at the other end are those who will not recycle no matter what.

The tools and techniques that each manager has available include a variety of styles of trucks, such as the venerable rearloader, the sideloader, the frontloader, and the multiple-compartment truck, in either a manual, semiautomated, or automated configuration. Containers can range from clear- or colored-bags, stackable boxes, bins, and carts, in a variety of sizes and styles. There are also employees who might be asked to simply sit in the cab of the truck and pull a lever to dump the container or who might be asked to lift and separate materials into fibers, metals, glass, and plastics at the curb in weather conditions that range from summer heat to winter snow.

Once the materials have been collected, how they are prepared can affect the quantity and quality of the end product. And how they are processed will be a factor of the method of collection. If separated at curbside, processing might just mean keeping the materials separate until they can be baled. If collected in a single stream, the material will have to be picked and plucked across a variety of screens, magnets, and conveyors to a final product ready for the baler. How much of each ton that makes it across the system and is recovered is a factor of customer behavior and the recovery efficiency of the processing system.

Each step or component selected can make a difference in material quality and quantity while adding both cost and value. It also can affect customer behavior and acceptance. The collection manager will want to pick up as much material per container as possible in a route that has the largest number of stops in the smallest distance. The recycling manager wants to see as much material per container as well, but wants the customer to be conscious of what goes into each container and, more importantly, what doesn’t. Neither manager wants bags of trash or engine parts in the greenwaste containers, or disposable diapers in the recycling containers since such contamination adds additional costs to the system to remove.

An Evolving System

The collection of recyclables and greenwaste has evolved over the past 15 years, driven by market growth, legislation, and technology. The earliest collection systems required the customer to simply bundle newspapers and place them on curbside, subject to wind, rain, and sun. These materials might be picked up using a pickup truck with a dump body or a converted step-van.

With beverage container laws coming into play, a bin for collecting containers was added, and the trucks grew in size to include larger-capacity bins that could keep the materials separated. As diversion mandates pushed the need to divert more materials, greenwaste programs were implemented, again starting out with bundles of brush at curbside. The effectiveness of recycling education programs pushed volumes and participation rates upward.

But system costs also grew. The need to add extra trucks and operators to collect the separated materials, and compartmentalized trucks to keep the materials segregated, drove efficiency down. Now instead of one truck, municipalities have up to three trucks picking up from the curb. Managers often were able to offset some of these additional costs through conversions from two- or three-person manual collection systems to one-person semi- or fully automated collection trucks. In most municipalities, the cost for diverting greenwaste to other uses and the marketing of recyclables provided further offsets to landfill tipping fees that threatened to spiral into orbit, and so the inefficiencies of the multiple-pass collection system were minimized through avoided-cost models.

New issues such as sagging markets for recyclables, unfulfilled promises of new recycling markets developing, NIMBYism toward composting facilities and material recovery facilities (MRFs), and fears of pesticide contamination have created new dynamics. While landfill prices have stabilized nationwide, liability costs, fuel costs, and various clean-air and -water regulations have continued to drive up collection costs. Couple this with a public that has shifted focus from environmental quality to homeland security issues, add the challenges to maximize diversion cost-effectively, and both recycling and collection managers will age prematurely.

Going After the Big Diversion

Located at the south end of California’s San Joaquin Valley, the city of Bakersfield is a major metropolitan area surrounded by agriculture. As a result, greenwastes makes up a large portion of the composition within the city, resulting in 35% of the city’s 46% diversion rate. Collection operations are split between municipal forces and private contractors, using a two-cart automated system that collects MSW and greenwaste separately. "The greenwaste recycling effort here is twofold," states Kevin Barnes, solid waste director. "There’s the automated cart system, but there’s also the free drop-off center for greenwaste, which all of the commercial gardening and tree services use. A lot of self-haul as well, which is operated without a tip fee and is funded from our refuse collection fees. There’s a large economic incentive for anyone with woody or greenwaste to use that. We’re unique probably in that we’re geographically isolated so we don’t have other jurisdictions besides our county coming to use the place for free, and we can charge the county an equitable share of costs."

Unique to Bakersfield is a citywide drop-off program that provides opportunities for residents to recycle. State beverage container recycling grants fund half this program, and the other half comes through refuse fees. The city operates the system, and it has been widely accepted by the residents. Even so, community interest in curbside recycling has grown recently and has resulted in the city developing a pilot collection program. "The pilot is for voluntary subscription service, which is probably unusual in the industry," explains Barnes. "We had a community survey in 2000 regarding various city services. While over half of the respondents thought curbside would be a good thing to have, two-thirds said they would not want any addition to the refuse fee for such a service. This small section of the community that has insisted upon having curbside was willing to pay a subscription fee, and the level of participation in that is being tested right now. We are seeing about 10% of the eligible area signing up."

According to Barnes, the pilot will determine two things: (1) how many customers will actually sign up for the program and (2) once the distance between customers has been determined, the calculated actual rate for the commingled subscription service. "That will provide feedback for the city council to make a decision on whether they would like to expand the subscription opportunities citywide or consider other options," continues Barnes. The current pilot area has approximately 6,000 homes, 600 of which have signed up for this subscription service.

As the city implements this automated collection, there is no question in Barnes’s mind regarding single-stream or multistream collection strategies. "I really didn’t think there’d be much debate. Single-stream seems to be the only significant way to collect a wide range of materials. It really depends on all local markets. If the material number is limited, then multistream would be fine. For anyone seeking a large portion of the stream, it seems cost-prohibitive to go other than single-stream."

Barnes estimates that a citywide curbside program would result in a 4% addition to their diversion rate. "I think that our blend of subscription and drop-off programs might end up being just about as effective as a citywide mandatory single-stream program, given that cost would be lower this way with the hybrid system," he predicts. "It may not generate quite as good a material, but it probably will generate a more pure recycling stream. In early operation of our pilot program we found the mix to be very clean because apparently the people take it seriously enough to sign up and pay for the convenience."

Bins, Bundles, and Variable Rates

In Gainesville, FL, a mix of strategies has been used to maximize recycling diversion. Using a variable-rate system based on the size of the carts, customers are encouraged to select a refuse cart size that fits their lifestyle and payment plans. The city provides recycling collection through a two-bin system, while collecting greenwaste in bags and bundles. This approach successfully has pushed the diversion to approximately 40% in the city while ensuring high-quality recyclables and green materials.

"The carts are 20, 32, 64, and 96 gallons," reports Gina Hawkins, recycling coordinator for the city. "The prices are $10, $13, $16, and $20 per month for the customers. We charge them on the utility bill so that they actually get that message every month when they go to pay for their water and electricity. What that’s translated to in our recycling program is nearly a 40% recovery rate for materials at curbside, not including all of our white goods in yard trash." Approximately 85% of the customers are using 32- or 64-gal. refuse carts.

The city’s recycling program consists of two color-coded bins. The blue bin is for cans and bottles and the orange bin is for paper products. Residents are asked to stack the blue bin on top of the orange bin to minimize blowing paper. Materials are collected in a two-compartment truck that transports the materials to the MRF. One of the significant advantages is the minimization of contaminants. According to Hawkins, a same-period comparison of contamination rates for a one- versus two-bin system resulted in a contamination reduction from 25 tons in January 2001 to 4 tons in January 2002. "You do have a human being looking at it, so if he sees something in there, he can throw a tag in there and leave it," she says. "We’ve found this to be an effective way of educating our customers."

Greenwaste is collected at curbside in either bags or bundles and is decontainerized at the truck. "We do this because the material is actually directly applied to a farm," relates Hawkins. "We put it on the farm, run over it with a piece of equipment called a chopper, and then let nature do its thing. It’s a private farm in Gilchrist County, just across the line from us. [The farmer] grows crops such as watermelons. The program does take decontainerizing at the curb, but it’s a chance to get the other contaminants, the occasional tricycle, out of the material."

The city has focused on two things: diversion and quality of materials. "Having the three trucks is meeting those needs in the best way because our materials processing facility has enjoyed good markets for our materials. We’ve been able to keep our costs down on yard trash by having a close-to-contaminant-free greenwaste chain. On the garbage side we’ve been able to use the one truck with a volume-based discount. That makes the rates very equitable, and people like paying for the service that they need. [A single person] isn’t paying as much as a family of six. It’s been very cost-effective, it’s achieving the diversion goals, and it’s given focus to the level of service that they demand."

Standardizing to Pick It All Up

In Mesa, AZ, a switch from twice-a-week collection allowed the city to reallocate its fleet of automated trucks to separate assignments of single-stream recycling, greenwaste, and trash collection. "In the state of Arizona, by law you have to pick up trash twice per week," states Jennifer Means, recycling and special project coordinator. "We had to petition the state to get a variance to that law that said we could do once-a-week recycling, once-a-week trash. A lot of outcry we heard was that we needed something for greenwaste because it was taking up what was left of our trash collection. We worked with the State of Arizona and did a pilot program of 3,000 homes over a six-month period."

In implementing the pilot project for greenwaste collection, the city experimented with a variety of carts. "We tried different types of barrels such as false-bottom barrels and black barrels with green lids so we didn’t have to buy barrels," Means points out. "Ultimately we decided the green barrel was the best way to go. We have over 25,000 on the street now." The city services 105,000 single-family homes through this growing program.

When implementing the recycling program, the city moved directly into single-stream, commingled collection. "The City of Phoenix started in 1987, so it had worked out some of the bugs," Means recalls. "We started the pilot programs with a few items and have been able to add to the list of items rather than take away. You’re seeing a lot of communities change over because it gets away from the compartmentalized trucks and it puts the burden back on the processor. We don’t have to buy different trucks. If a truck goes down, we simply wash out a truck and it can collect any of the other commodities that we have."

Mesa’s program uses two processors and shares revenues with both processors under separate agreements with each. "Depending on the contract that’s in existence, we either share revenue or we make money," notes Means. "Once we tip it on their floor, it’s their responsibility to sort it and market it." While minimum diversion rates are not part of the contract, the understanding is that 90% of the materials delivered will be marketed. "We have a 20% contamination rate on one contract, 15% on the other, but they are required to divert and market 90% minimum," she states.

For Mesa’s program, the positives outweigh the negatives relating to the need to run three trucks to pick up the materials. "We get a reduced rate on our greenwaste, and we make money on our recycling," Means concludes. "We could leave our greenwaste as part of our trash, but eventually we’re going to have to look at siting another landfill. They just extended the life of our landfill for another eight years, so something is working."

Biweekly Recycling

In order to maximize the volume picked up while lowering operations costs, the City of Plano, TX, provides fully automated, weekly collection of trash and biweekly collection of recycling to the 65,553 single-family homes it serves. Greenwaste is collected on a weekly basis using rearloaders, with the yard materials taken to the city’s composting facility.

For Nancy Nevil, solid waste manager, Plano’s experiences in developing diversion programs chronicle the technological changes in recycling and greenwaste collection strategies. The city first automated its refuse collection system in 1990, going from manual twice-a-week to automated. Drivers then were assigned to multiple compartment trucks to collect recyclables. "We sorted it into five or six sorts at the curb," Nevil recalls. "Then we went to a two-sort manual system where they put paper on one side and the commingled [on another]. From that, we worked on a split-body system and then went to single-stream. When we went to single-stream, we gave [out] 95-gallon containers and knew we did not need to pick them up every week."

Movement to the single-stream collection system involved two main issues. "The first one had to do with just trying to be more cost-effective because you start hearing all the stories around you about cities dropping recycling and cities deciding they don’t want to spend money on it," Nevil remarks. "We really felt like we needed to come up with a system that was as efficient as possible. The second benefit to going single-stream was being able to add mixed paper to the stream because before we just had newspapers and magazines. We were able to add a little bit to the system."

The efficiencies at the curb required an upgrade in the processor’s capability to handle the single-stream and to reduce contamination. "We’ve got a higher contamination tonnage now than we did before, but we’re also losing a lot of glass to breakage," observes Nevil. "You get people who are using their carts, and they try to put trash in their carts. We have cameras on the truck in the hopper, so when a driver sees that, he notifies the supervisor. The supervisor makes contact with the resident to explain what this does to our system."

Nevil predicts that single-stream will be the final frontier on the recycling collection odyssey. "It’s like automated refuse," she relates. "People trickled in with that over the years, and you still have people out there who have not gone to automated. Part of the reason is going to be just the cost efficiencies and the injuries. We went to automated refuse because workers’ compensation injuries were quite high. But I started seeing the same problem when we were doing recycling manually. [With the] lifting of those tubs with newspapers in them, I started to see elbow and shoulder injuries. With automated recycling, everybody’s a lot happier."

Lynn Merrill is director of public services for the City of San Bernardino, CA.