Trenching Safety

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Don’t dig your own grave

Rudolpho Monasterio had just purchased his first home with his fiancé and planned on moving in last May. Instead, on that same day, rescue workers in Holly Springs, N.C., pulled his body out from under 10 feet of dirt nearly 12 hours after the trench he was working in caved in.

In Harbor City, Calif., Jorge Ordonez was replacing a sewer line in a trench when the walls suddenly collapsed and he was buried. Firefighters said the trench was not properly shored up.

“The only trenching we do is for irrigation lines 16 inches to 24 inches deep,” says Leslie Herndon, safety officer at Greenscape, Inc., a landscape company located in Holly Springs. Yet, the trench cave-in in her community last May sent shock waves through the relatively small town.

“We used the trenching fatality as part of our training exercises the following month,” Herndon says. “We talked about the dangers of foregoing certain safety rules and why they’re put into place.”

How to dig your own grave

In a publication entitled “Excavations” (www.orosha.org/pdf/pubs/2174.pdf), Oregon OSHA (OR-OSHA) clearly spells out the extreme dangers of excavations of all kinds. The first page, called “How to Dig Your Own Grave,” shows a large photo of workers at an excavation with arrows pointing to the following: no protective system, spoils too close, excavator bucket over worker, no hard hat and no means for entering or exiting.

“A cave-in can trap you within seconds and kill you within minutes,” OR-OSHA notes. “Two cubic yards of soil weigh about 6,000 pounds. If you’re buried, you’ll suffocate in less than three minutes, and if you do survive, the weight of the soil is likely to cause serious internal injuries.”

David Allie, president of 4-Safety Training, LLC in Marquette, Mich. (www.4-Safety.com), is a safety consultant with expertise in excavations and trenching. He says that one of the biggest failures of employers involved in excavations and trenching is “the rush to get the job done.”

“They’re thinking a cave-in is not going to happen because it hasn’t happened before. They forget that an employee in a 4-foot-deep trench now has 3 to 4 feet of dirt above him. Most excavation accidents end up in recovery (of a body). It doesn’t take a very deep trench to bury somebody, especially when lying down or kneeling,” he says.

The hazards

When you create an excavation, you remove soil that provides horizontal support. Soil will eventually move downward into the excavation. The longer a side of the excavation remains unsupported, the more likely it is to cave in, OR-OSHA explains.

OSHA has many other requirements concerning trenching and excavations that are important to become familiar with. Also, cave-ins are not the only hazards associated with this type of work. Among the additional hazards, the National Institute for Occupational Safety and Health (NIOSH) notes, are these: working with heavy machinery, manual handling of materials, working in proximity to traffic, electrical hazards from overhead and underground power lines and hazards from underground utilities such as natural gas.

“Even a small piece of equipment puts pressure on the soil,” Allie says. “Also, if it is previously dug soil, it makes it very weak.”

Conducting sufficient training and having a competent person on-site to make decisions is critical, he believes. “If it rains heavily, or if it rained heavily overnight, you should get out of the trench because the soil can be weakened. Also, if your equipment touches an overhead power line, you will be killed,” he says.

Stiff penalties

Federal OSHA has placed a strong emphasis on trenching and excavation safety, and will not hesitate to fine employers hundreds of thousands of dollars when an incident results in an injury or death. In one recent case, OSHA cited a company in the Midwest for two “willful” violations, plus five other violations, and issued $155,000 in proposed penalties after part of an unprotected trench collapsed and a 25-year-old construction worker died. The two proposed willful violations were for failing to ensure that equipment and excavated soil from the trench remain at least 2 feet from the trench edge, and for failing to provide cave-in protection systems.

“The biggest thing is the training,” Allie says. “A lot of workers haven’t had it explained to them that if it doesn’t look right, they should stop. If you’re putting in a hole, is it wide enough? They need to know that you can be buried alive.”

Note: A good Web-based resource on trenching and what OSHA requires is OSHA’s Safety and Health Topics page on trenching and excavation. (Visit www.osha.gov/SLTC/index.html, and then search for trenching and excavation.) This site also has information on hazards, solutions and other available resources. Another excellent resource is NIOSH’s Trenching and Excavation Web page at www.cdc.gov/niosh/topics/trenching .

Barbara Mulhern is a Belleville, Wis.-based agricultural/horticultural freelance writer.