Transfer Stations
First of Two Parts
Transfer Station Safety Issues
Thoughtful facility design coupled with good operating practices help ensure transfer stations are safe places. Transfer stations should be designed and operated for the safety of employees, customers, and even persons illegally trespassing when the facility is closed. Designers need to consider that people might trespass on facility grounds during operating hours or after the facility is closed for the night. Most State regulations require security and access control measures such as fences and gates that can be closed and locked after hours. Signs should be posted around the perimeter, with warnings about potential risks due to falls and contact with waste. Signs should be posted in multiple languages in jurisdictions with high percentages of non-English-speaking residents.
Federal Occupational Safety and Health Administration (OSHA) regulations require facilities to provide safe working conditions for all employees. Although regulations specific to waste transfer stations do not currently exist, general OSHA regulations apply as they would to any other constructed facility. State, tribal, and local workplace safety regulations, which can be more stringent than federal regulations, also might apply. Some state, tribal, or local governments might require a facility’s development permit to directly address employee and customer safety. State and tribal solid waste regulations, for instance, often require development of operating plans and contingency plans to address basic health and safety issues. Transfer station safety issues are the facility operator’s responsibility. A facility must take steps to eliminate or reduce risk of injury from many sources, including the following.
Exposure to Potentially Hazardous Equipment
Transfer station employees work in close proximity to a variety of hazards, including equipment with moving parts, such as conveyor belts, push blades, balers, and compactors. Facility operators should develop an employee equipment orientation program and establish safety programs to minimize the risk of injury from station equipment. Using locks or tags that prevent equipment from operating until they are removed (lockout/tagout systems), for example, effectively minimize hazards associated with transfer station equipment. Transfer stations operators must implement and strictly enforce rules requiring children and pets to remain in the vehicle at all times. Posting signs and applying brightly colored paint or tape to hazards can alert customers to potential dangers.
Personal Protective Equipment
Transfer station employees coming in close contact with waste and heavy machinery should wear appropriate personal protective equipment. Common pieces of protective gear include hard hats, protective eye goggles, dust masks, steel tipped boots, and protective gloves. If working in close proximity to loud machinery, hearing protection should be used as well. Check state and local codes and regulations to see if any personal protective equipment standards exist. Ensure that all facility employees are using the appropriate equipment and are properly maintaining it.
Exposure to Extreme Temperatures
Facilities located in areas of extreme weather must account for potential impacts to employees from prolonged exposure to heat or cold. Heat exhaustion and heat stroke are addressed with proper facility operations, including good ventilation inside buildings, access to water and shade, and periodic work breaks. Cold weather is addressed by proper clothing, protection from wind and precipitation, and access to warming areas. Extreme temperatures typically should not pose problems for customers because their exposure times are much less than those of facility workers.
Traffic
Controlled, safe traffic flows in and around the facility are critical to ensuring employee and customer safety. Ideally, a transfer station is designed so traffic from large waste-collecting vehicles is kept separate from self-haulers, who typically use cars and pickup trucks. Facility designers should consider:
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Directing traffic flow in a one-way loop through the main transfer building and around the entire site. Facilities with one-way traffic flow have buildings (and sometimes entire sites) with separate entrances and exits. The transfer trailers, in particular, are difficult to maneuver and require gentle slopes and sufficient turning radii. Ideally, these trailers should not have to back up.
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Arranging buildings and roads on the site to eliminate or minimize intersections, the need to back up vehicles, and sharp turns.
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Providing space for vehicles to queue when the incoming traffic flow is greater than the facility’s tipping area can accommodate. Sufficient queuing areas should be located after the scale house and before the tipping area. This is in addition to and separate from any queuing area required before the scale house to prevent traffic from backing up onto public roads.
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Providing easily understood and highly visible signs, pavement markings, and directions from transfer station staff to indicate proper traffic flow.
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Providing bright lighting, both artificial and natural, inside buildings. Using light-colored interior finishes that are easy to keep clean is also very helpful. When entering a building on a bright day, drivers’ eyes need time to adjust to the building’s darker interior. This adjustment period can be dangerous. Good interior lighting and light-colored surfaces can reduce the contrast and shorten adjustment time.
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Providing an area for self-haulers to unload separately from large trucks. Typically, self-haulers must manually unload the back of a pickup truck, car, or trailer. This process takes longer than the automated dumping of commercial waste collection vehicles and potentially exposes the driver to other traffic. It is often a good idea to provide staff to assist the public with safe unloading practices.
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Requiring facility staff to wear bright or conspicuous clothing. Personnel working in the tipping area especially must wear high visibility clothing at all times.
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Installing backup alarms on all moving facility equipment and training all vehicle operators in proper equipment operations safety. Backup alarms must be maintained in proper working condition at all times. Cameras and monitors can also be installed as an additional precaution.
Falls
Accidental falls are another concern for facility employees and customers, especially in facilities with pits or direct dump designs where the drop at the edge of the tipping area might be 5 to 15 feet deep. Facilities with flat tipping areas offer greater safety in terms of reducing the height of falls, but they present their own hazards. These include standing and walking on floor surfaces that could be slick from recent waste material and being close to station operating equipment that removes waste after each load is dumped. Depending on the station design (pit or flat floor), a number of safety measures should be considered to reduce the risk of falls.
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For direct gravity loading of containers by citizens, a moderate grade separation will reduce the fall distance. For example, some facilities place rolloff boxes 8 feet below grade to facilitate easy loading of waste into the container (so the top of the rolloff box is even with the surrounding ground). This approach, however, creates an 8-foot fall hazard into an empty rolloff box. Alternatively, the rolloff box can be set about 5 feet below grade, with the sides extending about 3 feet above the floor. This height allows for relatively easy lifting over the box’s edge, yet is high enough to reduce the chance of accidental falls.
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For pit-type operations, the pit depth can be tapered to accommodate commercial unloading at the deep end (typically 8 to 12 feet) and public unloading at the shallow end (3 to 6 feet).
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Safety barriers, such as chains or ropes, can be placed around the pit edges at the end of the day or during cleaning periods to prevent falls. These barriers, however, should be removed during normal operating hours as they are a trip hazard and can interfere with the unloading of waste.
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Substantial wheel stops can be installed on the facility floor to prevent vehicles from backing into a pit or bin. Some curbs are removable to facilitate cleaning.
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Locating wheel stops a good distance from the edge of the unloading zone ensures that self-haul customers will not find themselves dangerously close to a ledge or the operating zone for station equipment.
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To prevent falls due to slipping, the floor should be cleaned regularly and designed with a skid-resistant surface. Designers need to provide sufficient slope in floors and pavements so that they drain readily and eliminate standing water. This is especially crucial in cold climate areas where icing can cause an additional fall hazard. Because of transfer stations’ large size and volume and the constant flow of vehicles, it is impractical to design and operate them as heated facilities.
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Use of colored floor coatings (such as bright red or yellow) in special hazard zones (including the area immediately next to a pit) can give customers a strong visual cue.
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Designing unloading stalls for self-haul customers with a generous width (at least 12 feet when possible) maximizes the separation between adjacent unloading operations and reduces the likelihood of injury from activity in the next stall. For commercial customers, stall widths of at least 15 feet are needed to provide a similar safety cushion. This is particularly necessary where self-haul and commercial stalls are located side-by-side.
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If backing movements are required, design the facility so vehicles back in from the driver’s side (i.e., left to right) to increase visibility.
Next month, we’ll cover noise, air quality and hazardous waste precautions.
— From www.epa.gov/osw/nonhaz/municipal/pubs/r02002.pdf.