Running a plastics collection program at little or no additional cost is a possibility, based on the results of a recent one-year, experimental partnership.
Although the high cost of plastic recycling is well known - collection costs range from drop-off systems at $100 per ton to curbside systems at $1,000 per ton - the Delaware Solid Waste Authority (DSWA) reduced its recycling costs more than 40 percent by using Polymer Resource Group (PRG), Rosedale, Md., a post-consumer plastic reprocessor, to collect, sort and market its plastics.
In addition to lowering costs, PRG also increased DSWA's plastic bottle recapture rate from 12.7 percent to 14.9 percent (see chart). The partnership arose under guidance from Recycling Concepts Inc., Covington, Ky., and Burroughs Consulting Inc., Lutherville, Md.
DSWA operates 120 unstaffed drop-off recycling centers across the state serving a population of 700,000 spread over nearly 2,000 square miles. Nine commodities are collected in various containers, including narrow-necked plastic bottles.
PRG's collection plan, developed by Recycling Concepts for DSWA, was based on information from a 1992 plastic collection study conducted by R.W. Beck, Tampa, Fla. The study showed that mixed plastic bottles, with a reject level of less than 10 percent, collected in eight yard bins located at 20 unsupervised, urban sites in Tampa could be serviced at a cost of $80 per ton. PRG bid $190 per ton due to higher costs of servicing Delaware's many low-volume sites in rural communities.
An independent hauler provided the collection service for DSWA at a flat hourly charge using equipment, schedules and routing specified by PRG. The plan used a 36-yard, full pack front loader as the main collection vehicle which transported materials directly to the company's processing plant, approximately 100 miles away.
Original calculations indicated that, with drop-off traffic evenly spread over the week, the program could be serviced in approximately 70 truck hours. Experience quickly showed, though, that the traffic was not evenly spread and that, even though PRG was collecting 35 percent to 40 percent more material in the truck than the Tampa study predicted, more than 100 truck hours per week were needed to limit bin over-flows during peak periods.
Collection operations were accompanied by extensive data collection and as the database grew, servicing schedules were re-fined.
However, even af-ter a full year's op-erations, there still were significant un-controlled and only partially explainable variances in the system. As a re-sult, unpredicted overflows continue to be a low level problem for the hauler.
Possible variance sources in-clude:
* resident stockpiling through bad weather;
* season changes (e.g. beach house and dorm room cleanouts);
* shopping center sales events; and
* collection vehicle driver reporting problems.
During the course of the year, several modifications to DSWA's program were identified which would have contributed to more efficient operations, spot problem reductions and increased participation. These included:
* Placing a back-up container at every site. About 70 percent of the sites had only one container and, thus, had no surge capacity for unexpected traffic.
* Posting an "800" phone number so users could notify the collector directly of any problem. DSWA's current "800" number must pass through several communication levels before reaching the collector.
* Encouraging a partnership be- tween DSWA's site inspectors and the hauler.
Although some progress was made on the last point, there has been no action taken on the first two.
The key concept in cost effective plastic bottle collection or any other material is filling a truck quickly enough so the material's value exceeds the cost of loading and taking the material to market.
In Delaware, 7,700 pounds of mixed plastic bottles were loaded into a 36-yard packer truck. The load's value was $385.00 at 50 per pound. The truck operator and scheduling support cost $65 per hour. In theory, if the truck could be filled and delivered to PRG in 5.92 hours, the plan would break even.
DSWA had several sites with multiple 7.5 yard bins for plastic. Each full bin held about 200 pounds (38.5 full bins equals one truck load). In regular operations, three sites were serviced each hour, including transport to PRG. If each site had two full bins, the truck could reach capacity in 19 stops and drive to PRG in 6.25 hours.
Thus, in this scenario, break-even plastic collection could be approached without even counting a-voided tip fees. In practice, however, this could not be achieved because there were not enough multi-bin sites and monitoring systems warning of full bins.
Although achieving low- or no-cost recycling of any commodity is a complex task, it can be done. In general, the formula is usually community-specific, but some universal criteria must be met:
* one or more processors producing materials have a market;
* a collection-through-intermedi- ate processing infrastructure that provides an economical bridge between generators and end users;
* a jurisdiction with a long-term recycling commitment, willing to make strategic changes in its program; and
* a trade association that will support the development of a sound approach to recycling its commodity.
In the end, DSWA choose not to extend its partnership with PRG because it wanted to begin sorting and marketing the plastic at its own facility in Wilmington, Del. However, PRG will continue to be a potential customer for the city's recycling program.