An integrated waste system is like a jigsaw puzzle: Sundry pieces fitting together to form an entire picture. However, there are limitations to this puzzle, because not every system will need all the pieces, and the size of each piece will vary from system to system.
For example, an integrated waste system located in the East Coast's crowded metropolitan areas will use transfer stations or waste-to-energy (WTE), while a Southwestern system will be more concerned with recycling processing and marketing, and landfills.
"The system's approach is to have all the pieces work together for the benefit of the whole," says Michael Long, executive director of the Solid Waste Authority of Central Ohio, Grove City. "It's like knitting a sweater: We follow certain procedures and patterns to make it come out right.
"You've got to know what your community is willing to pay and what kind of services it wants. Then, you try to put together the best system you can, using source reduction, recycling and waste-to-energy, if that's appropriate for the community."
Collection is the biggest component of an integrated waste system and probably the most difficult to manage. "It's the largest piece of the puzzle - 50 percent to 75 percent of the total," says Laith Ezzet, vice president of Hilton, Farnkopf and Hobson, a Newport Beach, Calif.-based solid waste consulting firm.
"It's also the piece that is the most decentralized," he continues. "You have all these individual collection transactions taking place over the city, and you have different crews out in the field. It's more difficult to manage, and, as a result, there are more things that can go wrong or that might not be done efficiently.
"It's different from the landfill, for example, where all the activities are confined to a smaller space, and you can observe them.
If your goal is to maximize your system's efficiency and look for cost savings, you should spend your time on collection."
Collection is the heart and soul of an integrated waste system because it's the gateway where all the materials enter. Selecting of a collection system involves not only determining what is the best collection method, but also what will work best for recyclables, green waste and food waste from residential, commercial and industrial accounts.
System designers must determine the types of materials that will be collected in each stream and how these materials will be prepared for collection.
In some systems, this means developing collection or alternative disposal options for household hazardous wastes (HHW), tires, batteries or used motor oils.
Designing a system also means understanding the needs of the jurisdiction being served. For example, San Francisco required commercial recycling, curbside recycling, medical waste operations, organic operations, handling construction and demolition sludge, land spreading, HHW and document destruction, says Steven "Moose" Jones, the industry representative on the California Integrated Waste Management Board, Sacramento. "When you can vertically integrate your programs, you take care of the customer," he says.
Knowing what materials can be handled in which system requires first defining your system, then educating your customers as to the system's requirements. "Education helps reduce the amount of waste and encourages recycling such as grass cycling and back yard composting," says Robin Depot, executive director for the Northeast Maryland Waste Disposal Authority, Baltimore.
"In our area, the residents are expected to sort their trash, but they can't do that unless they know the components they're sorting and [the reason for sorting]. Putting out the right material on the right days in the right containers is really important," he says.
A Sortin' We Will Go Once a material has entered an integrated waste system, further sorting, high grading, consolidation or transportation must be examined in order to maximize the material's value and minimize the ensuing costs.
The Southeastern Public Service Authority (SPSA), Chesapeake, Va., has several decision points through which materials must move before reaching their final destinations.
"We recycle [in] two traditional ways," reports Executive Director John Hadfield. "Newspaper, glass bottles, plastics, aluminum cans, household batteries and tin cans are collected curbside from homes. We also have a drop-off program that residents or businesses can use [to dispose of] the same basic products. What isn't picked up in the recycling program is brought to us either by municipalities or commercial haulers."
SPSA segregates the materials into two categories:
* processable waste that can go through the refuse derived fuel (RDF) plant to create a fuel and
* waste to be landfilled.
"We have a RDF system that is a little less forgiving of the kind of material we put through it, so we have to be selective in picking waste that can be processed into a fuel," Hadfield explains. "It's what we do with virtually 50 percent of the waste that we manage. It's a growing part of this authority's operation."
For many jurisdictions, especially those along the East Coast where landfills are not available locally due to siting issues, WTE plays an important role. Currently, there are 112 WTE facilities operating in the United States.
"As more communities decide what to do with their garbage, waste-to-energy [will be] an economical option in many areas of the country," says Katie Cullen, vice president of the Integrated Waste Services Association, Washington, D.C.
"In some areas, [WTE] is not economical because landfill prices are inexpensive. But many urban areas are considering it."
"You have to look at the pieces in an integrated waste system that make economic sense," says Paul Varello, chairman and chief executive officer of American Refuel, Houston. "For example, in some cases, recycling certain products in certain markets simply is not economical. The recovery of energy is critical. Facilities that combust the waste in an environmentally safe and sound way use that waste at least one more time and recover energy out of it before we bury it."
Designing an integrated waste system also involves engineering effective transportation systems to move the materials to their final destination. In some areas, this may involve transfer stations in order to move the most material per load.
This also can be the portion of the system with the most built-in inefficiencies, due to the variables involved with moving materials that change from day to day, and that can be subject to interruptions due to weather or traffic.
"We just completed a study looking at our competitiveness where we benchmarked ourselves against both public and private sector organizations," Hadfield says. "Roy Weston company looked at the landfill, the transportation system and the waste-to-energy system, and found that we were competitive.
"However, they found some ... weaknesses. Our transportation system is probably the least efficient. We operate eight transfer stations, our own landfill and a waste-to-energy plant.
"Also, we have a relationship with Virginia Beach and its landfill, which we use," he says. "Waste coming into a transfer station could go to any of those destinations."
One of SPSA's weaknesses is the inability to control the timing of waste deliveries onto the transfer floor.
"Because we don't schedule waste coming in, we don't have a great deal of certainty of what is coming into a facility on any given day at any time," Hadfield says.
"We end up with some of our transfer trucks in line, sometimes three deep, waiting for the transfer station activity to either pick up or slow down."
Rollin' Me Down the Highway Often, creative solutions are necessary to solve transportation inefficiencies. In Montgomery County, Md., the reluctance to add additional infrastructure required the Northeast Maryland Waste Disposal Authority to turn to rail haul. "Once the county made the decision to build a waste-to-energy facility, of course, the siting was controversial," Depot recalls.
Originally, the authority planned to site the WTE facility at the transfer station, but since the area was too populated, it decided to build the facility 18 miles away in a more rural part of the county.
The problem was that the road between the transfer station and the proposed WTE facility is only two lanes. The county did not want to enlarge it and risk losing its rural characteristics. That's where the train idea came in. Since a rail track already existed between the transfer station and the power plant, it was convenient to transfer this waste via the train.
The rail haul system proved so efficient that its use was expanded to include hauling yard wastes to a composting facility located next to the WTE site.
"It would seem like a very static system, but it has been surprisingly adaptable to different needs," Depot says.
"We hope to continue using the rail for recyclables in the future."
It Ain't Easy Being Green The processing of recyclables, whether at curbside or in a central material recovery facility (MRF), continues to be a challenge, especially as many states approach the next waves of waste diversion targets. While many communities have implemented residential recycling programs, commercial sector recycling is becoming more attractive.
At the Solid Waste Authority of Central Ohio, Grove City, one of the key upcoming issues is whether to site a MRF to capture more of this commercial waste stream.
"Our targeted waste stream right now is the city of Columbus because it's a huge opportunity for waste reduction," states Executive Director Michael Long. "It's rich in recyclable material from commercial, small- to medium-sized businesses and low-rise office complexes. Now, we're reviewing whether we should have a MRF for those targeted waste streams."
The authority already has ventured into recyclable collection, using the reverse of the manufacturing industries' concept of just-in-time delivery. "We've implemented a just-in-time collection program for small businesses," Long says. "We come out and pick up their recyclables - in this case paper - only when there is a minimum quantity on hand.
"Thus, we're picking up product, not air. We try to squeeze every bit of economy that we can out of the collection of that paper."
Long sees pay-as-you-throw becoming the key to further economies of scale, both in the collection of recyclables as well as in the waste stream. "We think that's the new frontier: to charge people for what they throw away and not what they put in their recyclable bin," he says. "Getting weigh scales on garbage trucks will revolutionize our industry - nothing will move stuff out of the garbage can into the recycle bin faster than that."
Economies of scale and investments in infrastructure must be weighed carefully, especially as a result of the loss of flow control.
Municipalities that made investments in facilities such as MRFs and WTE plants in the early '80s and guaranteed the investment with revenues from tipping fees, suddenly found themselves scrambling to re-adjust in the post-Carbone era.
As a result of economic competition, where materials now flow to the lowest cost options, both the public and private sectors must proceed cautiously with their investments in infrastructure for the integrated system. "When you're spending big capital dollars on a system, you need to be right on," Jones warns. "You can't make a mistake. When you're buying trucks at $120,000 apiece, you better make sure that they're the right trucks."
Building the integrated waste system for the future will not be easy because the size and contents of the box that the puzzle comes in varies from community to community.
"There's no model of a particular system that works in every community," Ezzet says. "The demographics, geography, collection-to-disposal site distances, waste generated per household and diversion facilities are different.
"As a result, your options and questions are endless: What type of collection equipment, containers and rate structures will you use? Doyou need transfer stations? Should you travel to more distant landfills rather than using landfills that are closer but more expensive? Do you site your own landfill or use a third-party facility? Will you need multiple companies?"
The answers will depend on what your objectives are for your system as driven by the residents, the businesses and your city council. Once you have your objectives firmly in hand, you can select the system that will meet those objectives.