Transfer Stations

Second of Two Parts

Transfer Station Safety Issues

In last month’s issue of Waste Advantage Magazine (August 2012), we covered some important transfer station safety issues, including dealing with hazardous equipment, personal protective equipment, exposure to extreme temperatures, traffic and falls. This article will cover some additional safety factors to consider.

Noise

Unloading areas can have high noise levels due to the station’s operating equipment, the unloading operation and waste movement, and customer vehicles. Backup safety alarms and beepers required on most commercial vehicles and operating equipment also can be particularly loud. The noise level also might cause customers not to hear instructions or warnings or the noise from an unseen approaching hazard.

Designers have limited options for dealing with the noise problem. The principal way to reduce the effects of high-decibel noise in enclosed tipping areas is to apply a sound-absorbing finish over some ceiling and wall surface areas. Typically, spray-on acoustical coatings are used. These finishes have a drawback, however. They tend to collect dirt and grime and are hard to keep clean and bright.

Using a rubber shoe on the bottom of waste-moving equipment buckets and blades and avoiding use of track-type equipment that produce high mechanical noise also limits noise. These approaches, however, can affect the transfer system’s operational efficiency.

Regardless of which approaches are employed, transfer station employees exposed to high levels of noise for prolonged periods of time should use earplugs or other protective devices to guard against hearing damage.

Air Quality

Tipping areas often have localized air quality problems (dust and odor) that constitute a safety and health hazard. Dust in particular can be troublesome, especially where dusty, dry commercial loads (e.g., C&D wastes) are tipped. Prolonged exposure to air emissions from waste and motorized vehicles operating inside the building provides another potential health threat to facility employees. Facility air quality issues can be addressed through a number of design and operational practices. These include:

  • Water-based dust suppression (misting or spray) systems used to “knock down” dust. Different types of systems are available. They typically involve a piping system with an array of nozzles aimed to deliver a fine spray to the area where dust is likely to be generated (e.g., over the surge pit). They typically are actuated by station staff “on demand” when dust is generated. Dust suppression systems can operate using water only or can have an injection system that mixes odor-neutralizing compounds (usually naturally occurring organic extracts) with the water. These dual-purpose systems effectively control both dust and odors. Water-based dust suppression systems, however, can have adverse economic impacts. The additional moisture added to the waste increases the weight of outbound loads, potentially reducing truck capacity and increasing costs. Use of handheld hoses to wet down the waste where it is being moved or processed, typically in a pit. Designers need to consider using convenient reel-mount hoses for this purpose.

  • Ventilation systems can control air quality inside enclosed transfer buildings. While the high roofs and large floor areas common in transfer stations put unique demands upon ventilation systems, it is still possible through engineering techniques to create the air velocities needed to entrain dust particles. One approach is to concentrate system fans and air removal equipment above the dustiest and most odor-prone area to create a positive airflow from cleaner areas. Often, the air-handling equipment is designed with multiple speed fans and separate fan units that can be activated during high dust or odor events. Filtering and scrubbing exhaust air from transfer stations is also possible.

  • If employees’ direct exposure to harmful emissions from vehicles and waste at the facility is not sufficiently minimized, respiratory aids such as masks might be necessary.

Hazardous Wastes and Materials

While MSW is generally nonhazardous, some potentially hazardous materials such as pesticides, bleach, and solvents could be delivered to a transfer station. Facility operators should ensure that employees are properly trained to identify and handle such materials. Some stations have a separate household hazardous waste (HHW) receiving and handling area. If the transfer station operates a program that manages HHW, the material is often collected by appointment only, during designated hours, or during special single or multiple day events.

All transfer stations need to be equipped to handle the occasional occurrence of hazardous waste, real or suspected, mixed with other wastes. Personal protective equipment such as goggles, gloves, body suits, and respirators should be on hand and easily accessible to employees. Because staff or customers might inadvertently come in contact with a hazardous substance, it is also good practice, and often required by code, to have special eyewash and shower units in the operating areas.

Typically, the transfer station’s operating plan will outline detailed procedures to guide station personnel in identifying and managing these kinds of wastes. Many stations have a secure area with primary and secondary containment barriers near the main tipping area where suspect wastes can be placed pending evaluation and analysis. Public education efforts can reduce the likelihood of hazardous materials showing up in solid waste.

Ergonomics

Improper body position, repetitive motion, and repeated or continuous exertion of force contribute to injuries. Both employers and employees should receive ergonomics training to reduce the likelihood of injury. Such training provides guidance on minimizing repetitive motions and heavy lifting and using proper body positions to perform tasks. At this time there are no federal ergonomic standards.

A few states, however, do have such standards under their job safety and health programs. The Occupational Safety and Health Administration’s Web site www.osha.gov includes a list of states with such programs and provides links to a number of these states’ Web sites.

www.epa.gov/osw/nonhaz/municipal/pubs/r02002.pdf.

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