Through forward thinking, careful planning, and responsible stewardship, transfer stations can evolve to be community assets that help toward the goal of minimizing material headed to the landfill and toward the goal of increased diversion.
Jeff Eriks and Evan Williams

Transfer stations are an important part of most local solid waste systems. They serve as a critical piece of infrastructure to minimize miles driven on local streets and allow route trucks to spend less time making long trips to a landfill and more time on collections routes. Over time, the general trend in solid waste has been toward increasing diversion. This is due to a variety or factors including preserving air space in the receiving landfills, minimizing organic material from the landfill-bound materials, and removing materials not appropriate for the landfill (household hazardous materials, ties, white goods, batteries, etc.). In addition to the MSW and diverted material streams, many facilities are also being tasked with handling the collection and transfer of single-stream recyclables and organics (food waste, yard waste, etc.).

The other challenge that the industry has run into is educating the general public about what they should and should not put in their waste and recycling receptacles. This has led to a lot of recyclables in the waste stream and a lot of waste in the recycling stream. Both private and public entities have worked hard to try and rescue recyclables from the waste stream and divert them from landfills, which leads to more areas on the tipping floor required to store these materials that they sorted onsite.

Given the wide range of collection, diversion, and transfer activity options, site operators need to take a comprehensive and flexible approach to planning and developing their transfer facilities to meet their immediate needs, while remaining able to accommodate future needs as the material stream and local needs dictate.

 

RIRRC Transfer Station – Cambridge Design and Construction – Tipping Floor and Push Walls with plenty of space to place bin block to create bunkers for segregation of materials.
Images courtesy of Cambridge Companies.

Material Stream
The first step for this process (new or existing facility) is to analyze the material stream the site will be receiving and is projected to receive (in the future). Ideally, your facility planning and ops teams will be able to plot out the in-bound materials and identify opportunities for diversion into non-MSW streams that have viable markets in your area. You should engage your stakeholders to determine whether there are opportunities for increasing materials to your facility if you offered additional diversion opportunities. For example, if you prohibit green waste as you typically do not receive enough of it for it to be worth your effort, that can become a self-confirming cycle. Have conversations with the public and third party haulers to see if there are opportunities to expand your range of materials accepted. Not all areas have the same end markets for materials, so reconciling the need for diversion with realistic end use is a critical consideration.

An additional consideration in this process is the incorporation of mandatory waste bans of certain materials in different states and markets. These are not uniform across the country, so understanding your local requirements as well as the potential for them to be expanded is an important consideration.

The last item to mention when it comes to the waste stream is the fact that you will inevitably receive relatively clean loads of C&D material and OCC (cardboard). As part of your transfer station facility, you will want to provide dedicated areas where you can have these clients tip and leave area around them so that your team can do some hand sorting and pull out the materials that are valuable in your market. As mentioned previously, this will vary based on where you are at, so be sure you know which items you want to sort and sell, and which will end up in the MSW loads going to the landfill.

Facility Programming
Once you have a good handle of the various material streams and the relative volumes of each, you will want to determine how much you want to store onsite and how you anticipate sending outbound. This will help to determine how much floor space you need for handling, storing, and possibly baling. After that space is identified, your team should overlay those requirements over your existing facility floor plan or use that to develop your new building floor plan. This will help your team determine if your current building is large enough and help you size the overall footprint of your new transfer station.

After the overall needs are developed and the floor area is set, you should start planning for which materials should be in different areas grouped by their load-out method as well as time they can be onsite. The materials can be separated into those that need to be cycled through quickly (MSW, organics, and single stream) or those that can be collected until volumes are sufficient to fill a truck (tires, e-waste, white goods, C&D, etc.). Ideally, the materials that you receive in the highest volumes should use the highest volume load-out, be that top load transfer trailers, compactors, or similar high-volume load-out approach. For the lower volume materials, these can often be stored in bunkers and loaded out via box truck or dry van box semi-trailer. For the lower volume materials, a loading dock would be ideal. One quick note on the bunkers, just be sure that the width of them is adequate to access with the equipment you are going to use to empty them.

Care should be taken in design and operations to ensure that materials that can contaminate others (MSW, organics, etc.) are stored separately or downslope from single-stream recycling, C&D, and other materials. The best practice is to have different tipping and loading areas, but that is not always practical, especially if you are using existing buildings and operations. The approach, again, should be to plot out the various materials by volume into piles based on daily in-bound and see how that impacts facility operations. Ideally, the load-out operations should be able to run smoothly throughout the day, allowing material to pile up during peak times and the load-out work down during slow times. The plan should be to have a clean floor with no materials remaining at the end of the day.

A sample of how bunkers are used to separate materials.

Site Planning
Working hand-in-hand with the goals of the transfer station building, the site development can contribute to the goals of increased diversion. If increased diversion leads to longer tipping times, that should be factored into the site circulation planning to ensure that your facility is not overwhelmed. In addition, you may need to re-evaluate your scaling, load check, and unloading oversight, as a primary driver toward increased diversion is lower rates for the diverted material(s). If the process for calculating this is not easy and transparent, adoption of the new approaches may be less than planned. Additional site considerations for transfer stations that intend to increase MSW diversion are increased areas for material storage bunkers, separate queuing for vehicles bringing in other materials, and longer unloading times.

These can vary greatly depending on the materials you intend to divert, your local weather, end users, and other factors, but your bunker approach should be flexible to allow your bunker arrangement to be revised should future needs and volumes change. Additionally, the bunkers should be placed on a heavy-duty paved area to allow for easy cleaning and containment or directing of stormwater. Depending on your needs, a roof over the bunkers can help with regulatory compliance and allow your materials to retain more value by staying dry. When planning site bunkers, consideration should be given to sight lines to the scale house, transfer tipping area, or other active areas of the sites where employees are present to ensure some oversight is possible to help deter people from dumping materials that you do not want in your facility.

Conclusion
Transfer stations, like the solid waste industry, are evolving to best reflect and accommodate the needs of their community. As end users identify materials that are not appropriate to be landfilled or when materials can find more profitable end markets, transfer stations will increasingly need to serve multiple roles. Facility operators should engage their operations teams as well as their community to best formulate their plans and identify material diversion opportunities. Through forward thinking, careful planning, and responsible stewardship they can evolve to be community assets that help toward the goal of minimizing material headed to the landfill and toward the goal of increased diversion. | WA

Jeff Eriks is President at Cambridge Companies. He can be reached at (219) 972-1155 or e-mail at J[email protected].

Evan Williams is a Design Project Manager at Cambridge Companies. He can be reached at E[email protected]. Cambridge Companies, Inc is a design-build firm, working with the environmental, waste and trucking industries for more than 25 years. During this time, more than 170 solid waste design-build projects have been completed, including new build, repairs, upgrades and/or modifications at transfer stations, recycling centers/MRFs, hauling companies and maintenance facilities, landfill facilities, office buildings and more. Cambridge Companies continually monitors the industry to determine any new needs, changes or improvements that will benefit their clients and improve their design-build solutions. For more information, visit www.CambridgeCoInc.com.

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