Communities Seek Cost Efficiencies

During the past decade, recycling programs have expanded dramatically throughout the United States and selected regions of North America. In 1988, the U.S. had approximately 1,042 curbside recycling programs in operation, servicing 8.5 million people. In 1993, the number of curbside programs in operation expanded to 6,678, servicing a population of nearly 101 million.

As the industry experiences periods of rapid growth, the associated costs of recycling programs have also been on the rise. In turn, as more recycling programs are placed under the microscope, communities are discovering that the cost of collection (usually a combination of fixed and variable costs) comprises the lion’s share of a waste management budget. Independent studies reveal that collection may account for as much as 50 percent of the typical total municipal recycling budget.

In an effort to reduce costs, the trend in the recycling industry is to review programs thoroughly and to find strategies to improve the efficiency of collection and processing methods. As curbside programs mature, advances in collection technology have enabled communities to reduce their overall collection costs by applying one or more of the following methods:

TWO CASE STUDIES

A few years ago, Pittsburgh implemented two of the above methods in an effort to improve the economics of their recycling program. The city was in a difficult position, paying up to $53 a ton just to get rid of recyclables. After reengineering their collection program – and investing some capital into a new collection fleet – the city was able to reduce this figure to $14.65 per ton.

The first order of business was to change the frequency of their curbside collection program. Initially, Pittsburgh provided once a week collection for curbside recyclables. In an effort to reduce collection costs, the city changed its collection frequency to once every other week.

This change has had a positive effect, according to Dave Mazza, Pittsburgh recycling coordinator. "It saved the city nearly $600,000 a year in collection costs and did not displace any significant volume from the curb," says Mazza. Many communities are wary about reducing collection frequency because of concerns about the potential loss of volume.

The second step for Pittsburgh was to purchase of new fleet of dual compartment collection vehicles, which were delivered in February 1997. One compartment is used for fiber (materials such as old newspapers, cardboard and mixed paper), and the other for recyclable containers (mainly cans and bottles).

The new vehicles have enabled the city to increase both the volume and the quality of recyclables collected at the curb while decreasing the overall cost of operation, according to Mazza.

In Pittsburgh, recyclable containers are collected in blue bags, and old newspaper is bundled separately. In the past, the city collected fiber intermingled with containers, which caused quality problems. As a result of the education program and the purchase of the new dual compartment trucks, residents are now keeping the materials separate, increasing the overall quality of the recyclable streams.

Prior to changing its collection frequency, the city operated 24 collection routes with 24 standard packer vehicles. With the combination of the new fleet and every other week collection, the city is able to service the same 24 routes with 12 dual compartment trucks.

Visalia, Calif., is one of many communities that has established what is known in the industry as a single pass collection method. Unlike traditional curbside collection programs, which require a separate collection for recyclables and municipal solid waste (MSW), the single pass method involves collecting both residential recyclables and MSW in a single stop and in the same truck. This saves communities money in time, labor, vehicle and even maintenance costs.

The city teamed up with Ruckstell Equipment, Fresno, Calif., to develop its efficient single pass collection program. The program uses a patented split capacity 110-gallon container (see photo on page 50) with a fully automated side-loading dual compartment collection vehicle (see photo on page 52) operated by one man. Residents place recyclables in one side of the split container, and MSW in the other side. The two streams are emptied into separate compartments in the same collection vehicle.

Visalia’s recycling program services 91,300 residents, collecting 25,000 tons per year of MSW and 8,400 tons per year of residential recyclables. The city also collects green waste with a separate collection route during six months of the year.

"The significance of the program is in its ability to capture a higher concentration of recyclables than traditional curbside collection programs," explains Dick Townley of Ruckstell Equipment.

With this new automated dual collection program, the city has been able to increase its landfill diversion rate from 12 percent to nearly 60 percent (including the separate yard waste collection). The new program has saved Visalia approximately $370,000 per year in avoided disposal costs.

"The type of program established for the city of Visalia could allow some communities to realize landfill avoidance cost savings of as much as $1 million per year," says Townley. This can vary greatly, of course, depending on the economics of each particular community.

The single pass collection program is an efficient method for co-collecting recyclables and MSW. Studies have also demonstrated that the commingled collection of fiber and recyclable containers can help most communities increase the efficiency of their recycling programs, because the more convenient a recycling program is for residents, the more they will participate.

Once the commingled materials are collected, however, they must be routed to a MRF equipped with commingled processing technology. Advances in MRF technology have made it possible for MRFs to evolve from the traditional twin line process (one processing line for containers, and the other for fiber) to the more advanced single line system. Due to a reduction in both the floor space and the labor required, single line MRF systems have been able to demonstrate advantageous economies of scale.

Some progressive commingled systems are even able to process commercial material along with residential recyclables. This usually means handling a large quantity of corrugated cardboard along with other materials.

Traditional twin line MRFs designed during the late 1980s and early 1990s require a physical separation of fiber from recyclable containers and are not equipped to handle material from a single pass collection program. Single line MRFs, however, are able to process commingled recyclables from single pass collection programs, such as old newspapers, residential mixed paper, cardboard, plastic containers, glass, steel and aluminum cans and other recyclables.

This is possible due to advances in automated processing technology and MRF design. Although the exact configuration of MRFs varies from facility to facility, newer MRFs use equipment such as eddy current separators for nonferrous, automated plastic sorting equipment, and advanced vibratory shaker screens and/or air separation systems to separate fiber from containers. Although some hand sorting for materials such as old newspaper from corrugated cardboard is still required, there is generally considerably less manual labor than in older MRF designs.

Recently, the city of Flagstaff, Ariz., partnered with Norton Environmental, Independence, Ohio, to design a single stream (commingled) residential curbside recycling system. The program will be implemented during the first quarter of 1998. Flagstaff’s residents will be provided with two 90-gallon containers: one for MSW and the other for commingled recyclables. The two will differ in appearance so it is clear which is intended for recyclables and which for MSW.

Because it is required by the state of Arizona, the city must provide twice weekly collection of MSW and/or recyclables, so the city will collect recyclables one day a week and MSW on another day. One-pass collection for recyclables and MSW is not possible there.

The program will use an automated, single compartment collection vehicle for collecting recyclables. Norton Environmental has designed an automated single line MRF that will process all of the city’s commingled recyclables and commercial material. The facility is currently under construction and is expected to be operational by February 1998.

With its new MRF and automated collection program, Flagstaff officials expect to divert nearly 35 percent of the residential stream from the landfill. When compared to other collection and processing options, the commingled system will save the city up to $1.2 million dollars in equipment and manpower, according to Ben Fisk, the city’s solid waste superintendent.

Another MRF technology capable of processing single collection material is mixed waste processing (MWP).

In this type of system, recyclables and municipal solid waste are not separated at all but are collected in one bag. The material is all processed to recover recyclables, yard waste and eligible fuel such as film plastics and various non-processable paper.

Some more advanced MWP systems have the ability to process and compost mixed organic material. Fine organic material – consisting of food waste, paper, dirt and mixed yard waste – is removed by the processing system and is transferred to a composting operation, which may be located adjacent to the processing plant.

One successful MWP plant is the Medina County Central Processing Facility (CPF) in Medina, Ohio. The Medina CPF has been in operation for four years. More than 400 tons per day of residential and commercial material is processed at the Medina CPF and the facility is able to divert nearly 60 percent of the inbound material from the landfill.

One of the advantages of MWP is in its ability to reduce collection costs through single pass collection. The system also eliminates the need for blue bags or special bins. In addition to the collection cost savings, MWP technology is also able to provide an aggressive recovery program. As many as 15 different material types can be recovered, and landfill diversion rates can be as high as 60 percent.

Some communities have objected to MWP facilities, however, due to the high capital costs and the difficulty in ensuring that recyclables are sufficiently clean since they have been mixed with solid waste.

But proponents of mixed waste processing say that savings in collection costs, avoided landfill disposal costs and generally high recovery rates make this method competitive.

In an effort to reduce recycling collection costs, many communities are implementing new collection technologies such as single pass collection systems. MRF technology has also advanced in order to accept materials from single pass collection programs, such as commingled fiber and containers.

If recycling is to survive, the costs associated with recycling programs need to be scrutinized. This includes not only the cost of material recovery facilities for processing recyclables, but also the costs involved in collection, landfill disposal of non-recyclable material and transportation.

In addition, possible revenues generated from the sale of recyclable materials should be factored into the equation.

Communities should consider all the variables to determine how a single pass collection program with an advanced MRF compares with their current programs, especially in terms of reduced hauling costs.

Already, some communities have implemented programs such as commingled collection, single pass collection and mixed waste processing and have achieved significant cost savings over conventional recycling programs.