As the focal point for many forms of waste, the transfer station has become the mediator of the disposal cycle.

By Stephen Lezinski

Waste, by definition, is a material that has reached the end of its useful life—to the user, anyway. Waste as a business term, however, translates into dollars, billions of dollars. Numerous companies and thousands of jobs exist today for the sole purpose managing solid waste.  In 1908, William A. Smith stated: “Engineering is the science of economy, of conserving the energy, kinetic and potential, provided and stored up by nature for the use of man. It is the business of engineering to utilize this energy to the best advantage, so that there may be the least possible waste.” In applying this message to modern day solid waste management (SWM), engineering continues to provide integrated solutions and multiuse facilities such as transfer stations to create a logical sequence of operations from waste collection through disposal that maximizes wastestream efficiencies.

Typically, three primary disposal routes exist following waste generation. Each waste disposal route has its advantages and disadvantages and must be custom-tailored for each community. Disposal Route 3 is of particular interest because the transfer station (repackaging) serves as a middleman between three components of the waste disposal cycle (collection, processing, and disposal). (See Figure 1.)

Figure 1

Background
Organized SWM originated nearly 100 years ago in the US, and has since evolved from a single-solution operation to an integrated series of processes to dispose of solid waste. With population growth consuming urban corridors and producing suburban sprawl, waste-generation rates are exploding. Small local landfills are being replaced by larger super-landfills that service communities on a regional (state) scale. These super-landfills are located in more remote areas, farther away from waste generators and requiring the long-hauling of waste.

Amended federal and state regulations now require enhanced factors of safety in design and financial assurance features (closure and post-closure care), which increase operational and maintenance costs for new SWM facilities. Coupled with escalating fuel costs, collection efficiency and vehicle payload is more critical than ever. 

These additional facility costs are passed on to the consumer base through increased waste-disposal tipping fees.  A tipping fee is a monetary value charged for the disposal of a unit weight of waste, usually on a per-ton basis. With existing landfills reaching capacity, local residents and businesses are taking the Not-In-My-Back-Yard, or NIMBY, approach to new landfills. This attitude brings forth a single question: What is the most economical solution for a community’s waste management needs?

To answer this question and assist with the changing dynamics of SWM, transfer stations have emerged as a centrally located “hub” for receiving smaller waste loads for consolidation and redistribution. This basic formula has proved successful for many other business units, including airlines, trains, buses, and especially freight. With this said, it is important to note that transfer stations are not an end or long-term storage point for solid waste.

What is a Transfer Station?
Sounds like a simple question; it is anything but. A transfer station is a SWM facility in which collection vehicles discharge their waste payloads, typically on a concrete tipping floor.  The waste can be deposited by type designation (municipal solid waste, wood debris, or metal), which is then navigated by rubber-tired loaders into an open pit for compaction. Following compaction, the waste is transferred into higher-volume containers (trailers, railcars, or barges) that are destined for a waste-to-energy facility for processing or to a landfill for disposal.  

People want to go places where they can accomplish multiple tasks in a single trip. Transfer stations aid this cause by providing a variety of solid waste services at one convenient location, such as drop-off facilities for household hazardous waste, waste oil, or yard waste, and by offering recycling facilities for aluminum, scrap metal, or electronics. As the focal point and distribution center for so many waste products, transfer stations can be deemed the “middleman” of solid waste.

Planning and Design
For the last 50 years, transfer stations have been providing intermodal solutions to many SWM systems that would otherwise experience an expensive long-distance haul to a waste-to-energy plant or landfill.  Many communities have accepted transfer stations into their surroundings; however, citizens may rarely consider the planning, design, permitting, and construction efforts required to build the facility. It’s this behind-the-scenes work that is critical for facility function and community
integration.  

Transfer stations should be developed around a single premise: to facilitate the most efficient and safe methods of waste receipt and transfer. Innovative SWM practices such as waste minimization, recycling, energy conservation, and environmental sustainability need to be incorporated into facility management and design. Other factors that influence the external environment also need to be addressed, including community health and safety, development buffers, environmental protection, traffic management, and future expansion.

There are countless guides and articles related to transfer station planning and design, but one of the most useful was created in 2005 by the Solid Waste Association of North America’s (SWANA) Transfer Station Committee. The committee prepared the Transfer Station Planning and Design Report, which focused on several components of transfer stations: site work, scale facilities, transfer buildings, solid-waste handling equipment, and support facilities.  As presented, the report is strictly a guide; however, it provides a foundation for many relevant issues of a new transfer station.  Above all, private, municipal, regulatory, and operational sectors must work together toward common goals to produce a mutually satisfactory facility.

Operations
Once transfer station design and construction is complete, the next critical path is to access operational priorities.  According to Richard Buss, program specialist II for the Montgomery County Division of Solid Waste Services (MCDSWS), there are “five primary operational priorities for managing and operating a transfer station: site health and safety, environmental protection, facility control and information management, waste transfer, and personnel and public education. Site health and safety takes precedence over all other operations at a transfer station.

Wearing appropriate protective gear, managing speed limits and vehicle queuing distances, segregating foot-traffic from heavy equipment at unloading areas, and ensuring directional signage is functional are some immediate concerns for site safety. Buss adds that “every facility is different, and sometimes you have to be creative with your approach toward operational safety and find points of motivation for your staff.  Educational opportunities, safety bonuses, or social gatherings may help to motivate your workers to be more safety-minded.”  Overall, each operational priority has its own role in providing a successful transfer station operation. 

Site Health And Safety
Transfer station managers maintain primary responsibility for ensuring the health and safety of their personnel and customers. Worker safety is essential to maintain efficient site operations and encompasses three major areas:  training, personal protective equipment, and communication. Management must be cognizant of the relationship between safe operations and satisfied end-users.

Operational training for transfer station personnel should generally consist of: personal protective equipment (PPE), confined space entry, and first aid/CPR.  Depending on job duties, more specific training may be required. For example, if managing a household hazardous waste drop-off, on-site staff should be certified in hazardous waste operations and emergency response and hazard communications, with yearly refreshers. The Occupational Safety and Health Administration (OSHA) maintains training requirements for individuals that may encounter hazardous waste under. 

Workers are at risk for exposure to a variety of materials and substances at a transfer station. The use of PPE can help reduce the likelihood of such exposure. Rick Dimont, program manager I for the MCDSWS, says that “typical PPE requirements on the waste tipping floor include half-face respirator with particular filters, headset-radios, safety glasses with side shields, hardhat-earmuff combo, safety vest, radiation badge, puncture-resistant gloves, and steel-toe boots with shank.” With periodic equipment inspections, these measures can protect worker health and safety.

On the tipping floor, disposal vehicles, heavy machinery and operations staff are confined within a finite area of available space.

Site safety measures need to be communicated between transfer station personnel and customers on a continual basis to manage site traffic, control a chemical spill, limit exposure during a radiation detection or to minimize conflicts on the tipping floor. Whether communication is verbal or nonverbal, it enables individuals to be on the “same page” during operations. This is important for site occupants, because safety does not permit second-guessing. Without an experienced, competent, and awareness-minded operations staff and customer base, a state-of-the-art waste management facility can be a very dangerous place. 

Environmental Protection
As part of their solid waste operating or refuse disposal permits, transfer stations are required by state and federal regulations to prevent, minimize, and control the occurrence of environmental contamination. Environmental requirements for transfer stations can be grouped into two main categories: site management (traffic control, stormwater management, leachate management, waste screening, spill prevention, and containment), and social management (air emissions, noise, litter, odor, vermin, and public relations). Site management requirements maintain operational functions, healthy and safety standards, and regulatory compliance. Similarly, social management requirements provide for “good neighbor” relations, health and safety standards, and regulatory compliance. Environmental protection measures often overlap to provide additional factors of safety.  Above all, protection measures need to be identified during facility planning and incorporated into facility design because operational staff must meet regulatory requirements on a daily basis.  

Facility Control
It’s a reality check for many communities in the US; most transfer stations are located near urban centers.  Because of this proximity, operational hours and traffic routing are hot topics. These issues require periodic evaluation because situations change, conflicts arise, and vehicle and waste volumes increase. 

Facility hours are a significant operational component because solid waste generation occurs on an hourly and daily basis.  To accommodate solid waste requirements, some transfer stations operate between eight and 24 hours a day, five to seven days a week. Facility opening and closing times need to be coordinated with morning and evening rush-hour traffic for initial and final waste receipts to occur during off-peak and noncommute hours.

Traffic routing and site access are other factors that must be controlled to minimize internal and external transfer station disturbances.  Site access needs to include a dedicated traffic turning lane off of the primary transportation route.  This is often a requirement of the governing department of transportation. Following site entry and vehicle weighing, traffic is routed to the tipping floor, usually in two lanes to manage flow. Traffic from other onsite waste and recycling drop-off centers also requires priority management because pedestrians are amidst heavy machinery.  Overall, traffic flow should be continuously monitored to balance site safety with an uninterrupted waste flow.  

Information Management
Following site access at a transfer station, vehicles reach a crossroads in the realm of solid waste: the scale facility. The scale facility serves multiple functions: site security, information management, and record keeping. Prior to reaching the information center, vehicles must pass through radiation detection equipment for security clearance. Federal and state regulations require radiation detection equipment to screen waste loads for hazardous waste.  This helps to prevent contaminated waste loads from being accepted and dumped on the tipping floor, which could potentially expose site occupants to chemical hazards.

Information management is carried out by the scales and associated data systems. Transfer stations often maintain multiple scales to provide for daily waste volumes and equipment breakdowns, maintenance, and calibrations.  Scales are available in a variety of formats and are generally 70 feet in length by 11 feet in width to accommodate waste-filled transfer trailers weighing up to 120,000 lbs.  Most importantly, scales have to be “weights-and-measures-certified,” because tipping fees are dependent on accurate vehicle waste weights.

 “Scales are the record keepers of a transfer station. They are connected to automated data management systems that instantly record, store, and recall details from waste transactions,” says Dave Herring, scale house attendant-cashier for MCDSWS.

“Vehicle information such as the date and time of transaction, vehicle owner, number and tare weight, and the waste type and origin can be recalled with a touch of a button.” Herring emphasizes that “software programs help to speed up payload weighing and improve vehicle throughput. Records of daily and monthly waste volume and profit can also be formatted for internal management and regulatory evaluation.” With some facilities accepting over 1,000 transactions per day, instant access to disposal information can be vital for meeting regulatory tonnage requirements. 

Waste Transfer
Waste transfer reminds one of the drive-through at a favorite fast-food restaurant. Customer orders and payments are made at a drive-up window (disposal vehicles weigh in at the scale facility). White pavement markings and signs direct customers to the pickup window, only to wait in line (traffic routing of disposal vehicles move to the transfer station entrance). The customer picks up the order and drives away (disposal vehicles deposit their waste load on the tipping floor and exit the facility). The only difference in this solid-waste scenario is that trash is being dropped off instead of food being picked up.

Now that we have a mental image of waste transfer, we can appreciate that it is a multistage process requiring a series of pit stops and coordination points. The waste transfer process sounds easy enough; however, there are many operational challenges, including vehicle staging, vehicle and waste inspections, equipment maintenance, communication and waste management, and material compaction and transfer.  It’s the management of these challenges that make or break a waste transfer operation.

Waste is collected and transported to the transfer station using a variety of vehicles: rear-, side-, and front-load compactors, as well as roll-offs and other residential-commercial cars, trucks, and vans. Vehicles must be staged at varying intervals on the tipping floor to provide site occupants with adequate line-of-sight. Operations staff must be knowledgeable on vehicle size, unloading mechanisms, turning radii, and sequencing to effectively navigate disposal traffic into and out of the facility. 

Operations staff members also perform yearly disposal vehicle inspections and random waste inspections.  A typical vehicle inspection includes lights, turn signals, hazards signals, seals along loading-compactor area, hydraulic lines, tires, tarps, and fire extinguishers. During waste inspections, operations staff may randomly select a disposal vehicle from the queue and direct the vehicle to dump its load on the tipping floor. The waste load is coned off and inspected for a mixed load: residential waste mixed with commercial waste (recyclables, cardboard, paper, etc.).  If a mixed load is identified during the inspection, the disposal company will receive a notice of violation and a fine.
Efficient waste transfer also requires properly functioning equipment. Malfunctioning equipment creates downtime, which slows the “repackaging” process and decreases overall facility efficiency. Good housekeeping practices (cleaning windows and side mirrors, keeping debris off of equipment) and regularly scheduled maintenance (inspecting hydraulic lines, connections, and hoses) can help prolong the lifespan of equipment and provide a stable uninterrupted operation.

On the tipping floor, disposal vehicles and drivers, heavy machinery, and operations staff are confined within a finite area of available space. Using effective modes of communication, site staff safely manage vehicle entry, waste deposition, and exit from the facility. Staff members also direct waste movement along the tipping floor toward the compactors.

The economical transport of waste is why transfer stations are constructed. Waste compaction and containment payload are controlling economic factors for transfer station operations. Optimum waste density (pounds per cubic yard) in a transfer container can be achieved though automated balers or operator-controlled compactors that condense smaller loose waste loads. Once compacted, waste is loaded in a variety of intermodal containers (trailers, rail cars, barges) to reach a waste-to-energy plant for processing or a landfill for disposal. A strategic site layout, the correct equipment (scales, loaders, compactors, transfer containers) and a skilled staff can provide for the efficient and economic transfer of waste.

Personnel, Public Education
As with most professions, continuing education is a critical element for adapting to change. Whether through a regimented college curriculum, hands-on-experience, or professional training, education enables individuals to apply working knowledge to mechanized technology. This “meeting of the minds” is essential to ensure site safety and to maximize efficiencies in waste collection, transfer, and disposal. 
Continuing education for solid waste professionals is available from industry-specific organizations such as SWANA. SWANA offers technical courses, seminars, and certifications for solid waste activities. Specifically related to transfer station operations, SWANA currently offers the following courses, which can be found on SWANA’s Web site http://www.swana.org/:

• Managing Municipal Solid Waste Collection Systems
• Managing Transfer Station Systems
• Training for Collection Operations

Personnel
The US Environmental Protection Agency (USEPA), with cooperation from various environmental agencies and professionals, also offers educational materials. Such materials aspire to advance the study and understanding of SWM regulations, facility design, siting, operations, and community relations.  Two such documents generated by the USEPA are listed below and can be found on EPA’s Web site (http://www.epa.gov/epaoswer/non-hw/transfer.htm):  

• Waste Transfer Stations: Involved Citizens Make the Difference
• Waste Transfer Stations: A Manual for Decision-Making

Educational opportunities through instructional literature, site tours, and training seminars are also available to solid-waste customers and local residents. “Behind the Scenes” is a multiweek course offered by MCDSWS that sets the standard for community education and involvement. According to Peter Karasik, operations section chief for MCDSWS at the waste transfer station: “Behind the Scenes was created in 1999 to offer interested members of the public information concerning transfer stations, landfills, waste-to-energy, recycling, composting, and hazardous-waste management operations. This program has created an open system for facility operations and solid-waste management and has specifically relieved much of the community’s anxiety related to the county’s waste transfer station located in Derwood, MD.”

Behind the Scenes has not only educated the public, Karasik adds, “But has also created many recycling volunteers and solid-waste advocates in the county.” This initiative further demonstrates that education is a critical link toward forming a coexisting relationship between the solid waste industry, local residents, and facility customers.

Conclusion
The bottom line is that, as population grows, consumption of natural resources increases, useable land area diminishes, and solid waste generation escalates. This waste requires collection, processing, repackaging, and disposal services. Transfer stations meet this need by:

• providing SWM options to decision makers for selecting the most cost-effective and environmentally sound disposal sites
• establishing a relatively local, flexible, and economical outlet for solid waste
• operating as a multiuse facility for residential and commercial waste drop-offs
• allowing for general waste screening, sorting, and recycling prior to disposal
• improving air quality, decreasing fuel usage, and reducing overall community traffic
• creating a more socially appealing facility within a community (short term storage of waste vs. final disposal at a landfill)

By using use the experiences gained through comprehensive siting, design, construction, and operations, solid-waste professionals can build a transfer station that is amenable to the surrounding communities, customers, regulators, and operators.

Stephen Lezinski is a solid waste specialist and technical writer for Gannett Fleming, Inc.

MSW - September/October 2006