Picture a landscape where the earth can spontaneously combust. Where the terrain is so unstable that it is prone to collapse and sinkage. Where multi-ton vehicles can tip over like toy cars. Visitors here must be constantly monitored to ensure their safety and to avoid the introduction of materials that could upset the delicate environment.
Such an environment is familiar to employees and customers of landfills who well know that the temperament of this terrain must be constantly soothed in order to avert disaster.
Landfill safety is more than just vague regulations and crossed fingers. Rather, employees must arm themselves for every possible hazard.
As landfills play an increasingly vital role in American waste management, so does the safety of the employees and customers. The government-mandated safety regulations, however, have been slow to gain momentum and national implementation. For the most part, landfill operators rely on a combination of experience and common sense to supplement the regional and national laws.
While Subtitle D of the Environmental Protection Agency's (EPA) Resource Conservation and Recovery Act was initially released in 1988, it did not become effective until October 1993.
In addition to such safety issues, proper waste water drainage, wildlife control, facility design and post-closure monitoring, Subtitle D also regulates the landfill site's location in order to prevent the inevitable problems affiliated with dumping waste on weak soil that is prone to collapse or earthquakes. These issues, though tangential to the daily operations of the site, are vital to the protection of the surrounding community and the environment.
Operators should pay special attention to Subpart C, which contains the criteria that impact daily safety issues such as regulating public access to the site and excluding the receipt of hazardous wastes.
Hazardous waste introduction - intentional or accidental - can be damaging to both employees and the environment. Dangerous materials range from fuel spills and hydraulic leaks that can occur when operating heavy equipment to the seemingly innocuous introduction of household chemicals.
Subpart C instructs that in order to avoid the introduction of dangerous substances, landfill operators must:
* randomly inspect incoming loads;
* inspect suspicious loads;
* record the results of inspections;
* train personnel to recognize dangerous materials; and
* notify the appropriate authorities if a controlled material is discovered.
Even if landfills are carefully monitored and haulers are questioned about their load, a dishonest or ignorant customer can still introduce a dangerous substance to the site. For example, said Jim Leiter, environmental manager for BFI, Missoula, Mont., a car battery company that unloads its old inventory in a landfill introduces a potential health threat to the site's employees because of the possibility of puncture by a bulldozer. This threat is present despite the fact that the amount of hazardous waste (battery acid) is not significant enough to cause regulatory problems.
Safety First Large machinery pose a serious safety threat. Accidents can occur when tractor drivers reverse without looking or when garbage is not properly compacted and a machine's weight causes the unstable ground to collapse. When employees must stand in the vicinity of moving machinery, it is vital that they wear safety orange in addition to the regulatory safety boots, gloves and hard hats.
Bulldozer operators must use caution when driving on landfill slopes. Rather than driving up or down the face, they should drive across to prevent tipping. The fill should also be compacted regularly to avoid building loosely-packed mounds that can collapse.
Because of garbage's flammability, fire is a frequent landfill torment. Chemical reactions, sparks from equipment or the introduction of smoldering waste may ignite blazes. Neal Bolton, an engineer at Blue Ridge Solid Waste Consulting, Bozeman, Mont., said fires can ignite easily when burning materials from a barbecue are brought into the landfill. While this material may not be discovered initially, the ashes can smolder for days before igniting and causing a serious situation.
Fighting fires at a landfill is the responsibility of the landfill's management in conjunction with the local fire department. The process is a staple in every landfill's safety operations manual.
Perhaps the greatest cause of accidents is ignorance. Bolton recalled an incident when an operator accidentally spilled about 100 gallons of fuel, which was highly flammable, but did not necessarily pose an emergency situation.
"Rather than covering the spill with absorbent materials, which is the fast, inexpensive way to handle the situation, the operator panicked and poured water on the spill," Bolton said. "Suddenly, a small problem became an expensive headache because a hazardous materials team had to be called in."
Setting Safety Standards A few specific national standards for landfill safety exist besides Subtitle D, especially concerning employee safety. Bolton said that there has been little national interest in the day-to-day safety of landfill operators. "OSHA says you have to wear a hard-hat, have access to a respirator, post warning signs and use certain equipment - like seat belts, working brakes, rollover protective structure for vehicles - but regulations about safety plans and training are not specific enough," he said.
Bolton emphasized the need for every landfill to provide appropriate employee training programs. "The most important way of making sure your training is working is to have an occasional dry run," he said. Safety meetings should be used to establish an effective chain of command so that every employee has a role in preventing and responding to an emergency situation as well as knowing when to evacuate an out-of-control area.
According to Bolton, safety meetings should be held about once a month, kept as short and informative as possible, attended by all staff and most importantly, should focus on information that the landfill operators will find relevant to daily operations.
Safety meetings are a prime opportunity to update safety plans, and remind employees of their role in accident response procedure. Under Subtitle D, written safety plans are required for every potentially dangerous area of the landfill - from confined space entry to hazardous materials. Safety plans should be regularly updated by consulting with regional and national regulatory bodies.
Diana Louviere, division compliance coordinator at Altamont Landfill, Livermore, Calif., recommended holding "tailgate meetings" to supplement the five to ten hours of safety training that site operators receive each month. This would require supervisors to give on-site safety briefings once a week at the beginning of each shift.
"It's important that all of our employees know what the conditions are like before they start working," Louviere said. "For example, they might need to know that on Wednesday there will be a construction crew on the site, or that because of heavy rains the dozers will have to be careful on eroding soil. Then everyone signs off on it so the managers know that they are aware of the situation."
Because of "right to know" regulations, these meetings keep employees informed of potential dangers and how best to avoid them. "For example, under the tank management plan, we have to let our operators know what is in every single tank and where it is located," Louviere said, stressing that education is imperative for quick response. "Everyone should know the basics - what the material is, who to call in an emergency - because [even though] the employees aren't required to touch anything, they need to know how to deal with [the situation]."
Landfill facilities should be designed for maximum customer safety. Roads should be wide and clear, and arriving trucks must maintain at least a car distance between each other. A person with a flag is helpful in these situations to guide the trucks as they enter the site. Safety instructions and speed limits (no more than 10 or 15 mph) should be posted clearly.
Bolton added that garbage trucks and the public's cars should be kept at a safe distance in order to monitor the drop-offs all visitors make. "Garbage haulers want to do the job and the public wants to see how it is done," Bolton said. By providing two entrances, employees can more easily screen the loads and be better prepared to do random load inspections.
Bulldozers and other machinery must be monitored carefully when operating near the entrance. Sites should ensure that there is sufficient space between the incoming trucks and the bulldozers moving garbage into the fill. This buffer will decrease the chances of collision as well as prevent the bulldozer from pushing materials into the line of waiting trucks.
Denying landfill access to children and scavenging citizens will avoid injury. "As interesting as it might seem to stand by and watch the dozers work, or to go in and look for scrap metal and junk, it is extremely dangerous for the public to get in the way of the employees," said Bolton.
Essential Ergonomics Employee productivity is dependent on their health and safety. Louviere said Altamont Landfill provides a wellness program based on the philosophy that "when people feel good about themselves they work better."
Additionally, Louviere said, "if there is a problem, they will be more likely to report it. I want to hear about paper cuts before they become infections so that we can do everything possible to get that person back to work. No one wants to lose time because a minor injury became something dangerous."
Preventing accidents is the responsibility of the landfill management, but requires the participation of the employees and customers. Education is the primary step to prevent accidents and create an employee-friendly landfill, and managers should take every opportunity to keep their site operators up-to-date on regulations and site policies. As landfills become an increasingly indispensable fact of waste management, national standards for safety are becoming more visible and vital to daily operations. All employees, in turn, must learn to apply these principles.
The safety plans of Santek Environmental, a Cleveland, Tenn.-based landfill company that designs, constructs and manages landfills in conjunction with local government regulations, have been used as a model for other Tennessee landfills. Cheryl Dunson, the Director of Marketing at Santek said that employee safety measures should not be cut when a site decides to cut spending. "Worker's comp is too expensive," she said.
In the event of an accident, Santek pursues a thorough investigation on whether the incident could have been avoided or if it was caused by factors such as weather, equipment failure or negligence. All accidents are reminders of the dangers of landfills, as well as signs of underlying facility problems.
In addition to monthly safety meetings, Santek has found that employee incentive programs are an effective means of maintaining safe working conditions. "We recently held a steak dinner and awards ceremony for a landfill that had an accident-free year," Dunson said. "We are improving company morale while encouraging employees to keep accidents and costs down."
Drilling landfill gas wells is a necessary process for recovery and control of the gas produced by the decomposition process. Placing the wells typically requires puncturing the landfill cap, then excavating a hole 24 to 36 inches in diameter down 40 to 140 feet.
Large quantities of landfill gas - methane, carbon dioxide and traces of oxygen, hydrogen sulfide and nitrogen - may escape into the surrounding environment during drilling and may continue until the well is capped.
The hazards are numerous. The gas can: displace the oxygen in confined areas; cause an explosion if in sufficient concentrations; travel to neighboring properties, causing odor complaints; and introduce hazardous substances into the environment.
A properly-designed and operated gas recovery system for drilling can significantly reduce these risks, while minimally affecting operational costs.
A typical drilling gas recovery system (DRGS) consists of a vault or box through which the drilling mechanism extends into the excavation. The box, designed to allow a continuous vacuum at the point of the excavation, is connected to a blower/ vacuum using a long, flexible hose.
Within the box is a slotted piping system for gas collection. The blower/vacuum forces the gas through the hose into a filter or gas destruction system to remove it from the work area and minimize the environmental effects.
The drilling box should:
* be lightweight, yet durable;
* extend at least twelve inches beyond the excavation on all sides;
* be preferably circular or octagonal;
* be low profile, yet tall enough to keep dirt from being drawn into the collection piping, but should still allow easy access to the drilling mechanism; and
* allow easy access for the drilling mechanism.
The collection piping should extend around the box's inside circumference and be manufactured of slotted or perforated high density polyethylene for flexibility. A filter screen should cover these slots to prevent trash or objects from entering.
The lid should be vertically split and hinged, and the hole in the center should be lined with flexible material to minimize the opening around the drilling mechanism.
Both the blower/vacuum system and the filter/ destruction system can be stand-alone units or sources at the site. In some conditions, it is feasible to install the entire landfill gas collection system, then go back and drill the wells, while using the system as the source of vacuum and filtration or destruction.
If a stand-alone blower/vacuum unit is used, the system must be explosion proof and provide a sufficient vacuum to maximize the collection. A typical unit is a 2-horsepower blower providing an inlet vacuum of 5 in. H.G., inlet volume of 125 ACFM at an inlet temperature of 80 degrees F.
The simplest and most cost-effective filter/destruction system is the activated carbon canister, which is supplied in a coated 55-gallon canister with a top inlet and a bottom-side outlet. It requires no operation and is small enough to transport. It absorbs odors and hydrogen sulfide in addition most volatile organic compounds that may be present.
A gas destruction unit could be a small, portable flare, approved by the local air pollution control district. Using a temporary or permanent system flare can pose difficulties due to high oxygen contents, which could shut them down. On-site sources of filtration or destruction, can be used if the box is attached to the permanent gas collection system.
Using the DGRS is simple if it has a proper design. At the site, the box is positioned over the excavation location's center. If it is too high for the rig to work over, then it must be dug partially into the ground. Once in place, the blower and filtration system is positioned far enough away to prevent the release of gases from affecting the work area.
The operator has the simple job of opening and closing the box's lid as the drilling mechanism withdraws to dump and then re-enters.
No additional labor is required; and if operated properly, the DRGS has minimal affect on the speed of the drilling process.
The cost depends on preference (stand-alone versus on-site blowers and filter systems). The drilling box will cost $4,000 to $5,000, with the blower unit ranging from $2,500 to $4,500. The activated carbon canister ranges from $350 to $750, but the replacement of the carbon is much less.
The box and the blowers are one-time investments that can be capitalized over many projects, and the cost of maintenance and operation is minimal. Additionally, box and blower systems can be rented for $650 to $750, and gas recovery boxes can be rented for $300 to $400.
Comply with all Subtitle D regulations and learn how it has been modified to meet the needs of your region:
* Hold monthly safety meetings and require all employees to attend.
* Operate machinery slowly and carefully.
* Let the public know that random load inspections occur.
* Regularly update safety plans.
* Celebrate success to encourage accident prevention.
* Clearly mark the area where the public arrives.
* Discourage scavenging.
* Provide materials to educate the public about how to dispose of materials that cannot go in the landfill.
* Keep fire extinguishers on hand and post the fire department number by the phone.