Safety is incredibly important to keep at the forefront of everyone鈥檚 minds starting at the beginning of the design phase and carrying it all the way through construction. Safety is a 24-hour mindset and each decision should be evaluated based on any impacts it could have on the operations of the facility.
By Jeff Eriks and Evan Williams
Safety should be a primary consideration when planning any new solid waste facility. The safety of your staff and visitors is of the upmost importance. When in the middle of the design process, too often there are a myriad of other considerations to balance鈥攂udget, schedule, operational needs, local planning requirements, future growth accommodations, and many more that can take the focus off safety. Sometimes, decisions are made to defer some items as a future operations consideration. This would be a mistake, as including safety considerations and incorporating planning and operational best practices can help make safety an integral feature of the new facility. These safety considerations can be grouped into four categories: Safety During the Design Phase, Building Safety Best Practices, Site Layout, and Site Safety Features.
Safety During the Design Phase
The best time to start planning for the safe design and operation of your facility is during the design phase. Once you have the building layout pretty well completed and the processing equipment design, you can begin to incorporate those and marry them together. It is at this time that you build a 3D model of your building as well as the 3D model of the equipment and start to compare them and look for potential safety risks. You should then begin to add additional exterior access points for equipment of personnel, work on connection points between different work areas, evaluate 鈥渄ark spots鈥� and maintenance 鈥減inch points鈥�, and ensure the maintenance team has full access to all areas with necessary equipment so they can do their job safely.
At the same time, begin to look at equipment traffic within the building tipping and bale storage area and evaluate any foot traffic that may be encountered as well and work on traffic patterns and develop a striping plan. The striping plan should address vehicle as well as pedestrian traffic to be as prescriptive as possible on where you do and do not want the various types of traffic to be.
Using the 3D models, you can also evaluate the need for overhead cranes, future phases for building and/or equipment expansion, how equipment may be installed, and whether there are any other changes that need to be made to accommodate the findings of those evaluations.
Most safety items can be addressed during this phase鈥攅specially most of the items we will discuss in this article鈥攂ut there will always be something missing that ends up being caught during safety walk throughs during construction. We encourage at least two walk throughs, with the last one occurring about six weeks before construction completion, so there is enough time to make the necessary changes.
Building Safety Best Practices Lighting
In a tipping area, the bay doors represent an area of risk, as the drivers backing in can be temporarily blinded as their eyes adjust from the exterior (sunny or bright) conditions to the dimmer interior. This transition represents a significant safety risk because this occurs just as the truck is backing into the building, and there may be other building users on foot who may be at risk. There are several strategies that can help with this. You can increase the lighting levels in the facility by using more and higher lumen output LED high bay light fixtures. The building can also incorporate translucent wall panels or skylights to further increase the interior lighting levels. To further help manage that risk, you can clearly delineate the floor walk zones for each tipping position.
Push and Scrape Walls
Another tipping area safety consideration relates to push and scrape walls. Where possible, the push walls should be permanently engineered cast-in-place concrete or steel assemblies. Temporary or stacking block assemblies can be attractive from a cost and operational flexibility standpoint, but for primary tipping areas, the risk to employees if they are knocked over is too great. The modular approaches can make sense for lower-volume areas and your team will need to gauge what makes sense for your needs, but they are not a substitute for a rugged durable push wall that can provide many years of reliable safe service.
Height
When designing the tipping area, ensure that the enclosure you design is adequate in height for your needs. This should take the form of an in-depth review and analysis of the types of vehicles and their specifications that you anticipate using in the facility as well as the yellow iron you will require. For example, some facilities get a lot of roll-off traffic, which can be very tall when tipping. In addition, if you intend to use an excavator, depending on the arm(s) you use, that can also be quite tall. We often see transfer station tipping doors with a 30′ height and the roof structure with 35′ clear to ensure those areas can safely operate without risk or damage to the overhead structures. We have even seen facilities using tippers to take in material that create a whole host of design requirements to safely back up onto, tip, unload, and then operate in the facility.
Structure
Special care should be taken to provide significant and robust structural column and door track protection. This can take the form of concrete-filled steel pipe bollards up to custom bent-steel assemblies tied to the building foundations and filled with concrete. Ideally, you are placing these structures so ensure they are highly visible to both the yellow iron operators as well as the vehicle tipping in the facility. The protective assemblies should be designed to shield both the building columns as well as the overhead door jambs, so they should overlap the door jambs by roughly 6″.
Overhead Doors
When specifying the tipping area overhead doors, they may incorporate several features that may make sense to your operation. First among these safety best practices is the use of a sensing-edge safety sensor. This uses a linear compressible assembly on the bottom of the door that automatically reverses the door if it impacts anything. This tends to perform much better (and more reliably) than IR sensors that project a beam at only one elevation, not to mention the issues of the IR beam in a dirty environment like a tipping area. Another overhead door safety consideration is the use of a continuous-contact close button. This requires the building user to hold the button down as the door closes. While this can be a minor annoyance to the employee, it requires the staff closing the doors to observe the area of the doors as they close to prevent anyone from entering the opening during the process, saving repairs and downed overhead doors and safety incidents.
Employee Areas
When it comes to planning a MRF facility, it is common for the admin and employee areas to be multi-story. If that is the case, the facility planners may want to consider placing the employee break room and locker rooms on the second level and connect that to the sorting platform with a catwalk. This approach keeps the vast majority of MRF staff off the facility floor, dramatically minimizing the risk of employee/forklift strikes.
Processing Area
When we talk about the processing area, this encompasses wherever there may be equipment. You want to design a process area that is safe to install, maintain, and walk around the equipment. The way to do this is to ensure you have plenty of lighting in and under the equipment, so that walk paths are lighted, regular maintenance areas are fully lit, and any smaller/tighter spaces are also well lit. Along with the lighting, you want to supply convenience outlets for additional lighting or tools that do not require long runs that create hazards. Another safety measure under the equipment is to paint walking paths in bright yellow and put up fencing in areas you want to keep people out of. Oftentimes, under equipment, there may be some areas of falling debris or low head clearance that warrant the fencing for safety reasons.
Bale Storage
The bale storage area has several safety risks inherent in it. The first is the constant use of yellow iron or forklifts to move bales around. The best way to deal with this issue is to ensure your bales are stacked in consistent rows at heights permitted by code. You do not want bales falling over. The second is to paint lanes for your forklift and for foot traffic. The third is great lighting in the area for best visibility. The fourth is making sure that trucks or trailers are adequately hooked to your loading docks. There is equipment out there that is made specifically for loading docks that ensure the trailer is locked in, thus eliminating movement when the forklift drives onto the truck and reduces risks of separation and the forklift falling. The last risk covers fire safety. As we all know, there is plenty of material in bale storage areas, so you need to ensure the pile height adheres to code and that you have the proper measures in place to prevent or stop fires.
As an overarching facility safety approach, minimize and eliminate confined spaces wherever possible. If they must be provided for some assemblies, provide appropriate signage. One way of minimizing confined spaces in a MRF is to provide open pits, where the back sides of the pits are left open with guard rails around the perimeter for employee fall protection. This type of assembly makes that pit area much easier and safer to maintain and keep clean.
Site Layout
When planning out the site plan, there are several safety-related considerations that can be incorporated that cover traffic movements to stationary places. Where possible, for facilities with a significant quantity of office staff or visitors, separate them from the collection vehicles. The goal will be to have a dedicated entrance for passenger vehicles that is separate from the commercial vehicle entrance. Many times, planning restrictions only allow one curb cut. In that case, separate these vehicles as early into the site as possible. Where these two groups of vehicles meet, try to make that intersection signaled or a full stop. You would also want to have the crossing on the driver鈥檚 side of the collection vehicle for better visibility for the driver.
Within the commercial/industrial vehicle circulation areas, careful consideration to how these vehicles move through the site is very important. This includes how the driver鈥檚 field of vision both forward and back can impact how they safely use the facility. Where possible, the site circulation traffic should be in one direction. Ideally, the traffic loops counterclockwise, allowing trucks to enter the site, cross the scales, unload/load, and exit without crossing the traffic lanes of other vehicles. Plan the traffic circulation where the backing up is on the driver鈥檚 side, helping to minimize blind maneuvers. All too often, the CAD-based vehicle tracking software can indicate a movement is easily done, but it does not factor in the complication and difficulty of backing up a truck on the passenger side where the tail end of the truck/trailer is not easily visible.
When designing the site, care should be taken to plan out how foot traffic will intersect with vehicle circulation areas. When pedestrians are crossing roads, there should be a striped crosswalk. Depending on the frequency, signage may also be prudent. In addition, the pedestrian paths should be set up to provide adequate site lines to approaching vehicles and place the foot traffic away from the building face to minimize turning corners directly into a traffic area.
Plan for and work through the logistics of emergency vehicle access around the property. Fire lane and site access requirements can vary greatly depending on where your facility is located as different jurisdictions have adopted widely varying site requirements. Given the inherent fire risks of solid waste facilities, your project design and development team should plan out how fire apparatuses will navigate and understand what areas must be kept clear to not impede a fire response. Typical considerations are clear areas around site fire hydrants, keeping circulation roads clear, and designing the site to allow easy access to the areas of highest fire risk.
Site Safety Features
As the facility site planning progresses, there are several site safety-related features you may want to include. When designing a transfer station or MRF tipping area, the site design should incorporate a designated hot load area. This is typically a sand or concrete area that is adjacent to the exterior circulation apron, allowing tipping directly from a collection vehicle that is observing a potential fire, as well as allowing a short trip from the building for the loader to push a load that is smoldering. So much of safety planning is intentional, so when an event occurs, what to do is clear. While troublesome that this needs to be done, it is a necessity in today鈥檚 world with lithium-ion batteries. That is the reasoning behind the designated hot load area.
Also provide large, clearly legible signage for all typical facility users. The signage can be color coded between different user types (commercial collections, resident, visitors, hauling, etc.). For sites that have complex travel lanes, large reconfigurable LED signage may make sense. Overhead gantry signs can help coordinate multiple lanes of traffic and help minimize confusion of site users as well as keeping people where they are supposed to be (and away from restricted areas). The goal of good signage is to help users easily see where they need to go, allowing them to focus on safely driving while at the facility.
The last key area to incorporate into your site design is a rally point for employees for emergencies. While not needed regularly, it is important to have the training done and a safe place to meet up that gets people away from the danger zone.
Safe Operations
Safety is incredibly important to keep at the forefront of everyone鈥檚 minds starting at the beginning of the design phase and carrying it all the way through construction. Three-dimensional models are great, but they cannot catch everything, which is why we schedule walk throughs at critical points of construction with the operations, maintenance, and safety teams. Safety is not a once-a-day thing; it is a 24-hour mindset and each decision should be evaluated based on any impacts it could have on the operations of the facility. | WA
Jeff Eriks is President and Evan Williams is a Design Project Manager at Cambridge Companies, Inc., a design-build firm, specializing in the environmental, waste, and trucking industries for more than 30 years. During this time, Cambridge has completed more than 200 solid waste design-build projects for transfer stations, recycling centers/MRFs, hauling companies, maintenance facilities, landfill support facilities, office buildings, and more. The Cambridge team continually monitors industry trends and ever-evolving needs to provide solutions when planning and building new facilities and improvement projects to ultimately benefit clients with design-build solutions. Jeff can be reached at Jeff@cambridgecoinc.com and Evan can be reached at [email protected]. For more information, visit .