Trenches may be mostly empty, but they’re full of hazards that can cost workers their lives. Learn what the risks are and what every firm should know about safety.
Trench shoring – the process of steadying trench walls to prevent collapses or cave-ins – is an essential aspect of all excavation work. These walls can be securely propped in several ways, such as hydraulic or pneumatic shores, and may utilize steel, aluminum, or timber shoring material. The materials must be in the best possible condition to ensure worker safety.
While excavating firms have options in how they shore a trench, they’ve got no choice whether they will. The Occupational Safety and Health Administration (OSHA) has strict guidelines excavators must follow to ensure the safety of their trench workers. The Bureau of Labor Statistics records that 130 workers died in trenching and excavation between 2011 and 2016.
OSHA regulations require that protective steps be taken with trenches 5 feet or deeper unless the trench has been excavated in entirely stable rock. Those 20 feet or deeper require a protective system designed by professional engineers or based upon tabulated data by the same.
The Basics of Safe Trench Excavation
OSHA boils trench-sense down to four key steps: soil, slope, shore, and shield. Trench walls must be sloped backward to a ratio of 1.5 feet for every foot of depth. They must then be shored with supports and shielded with trench boxes. Trench boxes aren’t intended to shore up the trench, but to protect the workers from any falling objects or collapsing matter.
It’s the employer’s duty to ensure a safe entry and exit route for the trench such as steps, ladders, or ramps. All entry and exit routes must be no further than 25 feet away from any worker in a trench. All materials and equipment must be kept away from the edge of the trench to reduce the risk of workers being struck by falling items. Surcharge loads should be kept a minimum of 2 feet away from the trench edge.
The Importance of Soil in Trench Shoring
Soil analysis is OSHA’s fourth recommended step. This process helps in determining if the ground can support the required degree of trench slope and shoring. A thorough inspection of the trench is required daily before any worker can enter, mainly because soil can be a very unpredictable medium. The site may seem perfectly adequate for a trench when a team starts excavating, but changing soil quality, water content, weather, and on-site activity can all make the trench potentially dangerous.
An inspector will assess the soil and shoring, then look for other risks like standing water or electrical and gas lines. Standing water may not seem very dangerous, but it can gradually erode soil and weaken the integrity of trench walls. The inspector’s findings must be made available on request for an OSHA compliance officer. Trench inspections are further recommended at the start of every shift and especially following strong natural events like heavy rain or winds.
Underpinning the trench may also be necessary during some excavations. This involves either deepening or widening the trench, processes that distribute the load over a wider area or make use of a stronger stratum of soil. The extent to which these measures will be required depends on the site, but the price of ignoring them can be deadly.
The Cost of Non-Compliance
The real cost of ignoring safety is measured in human injuries and lives. Beyond that, the fines for violating OSHA regulations are also significant. They are adjusted annually for inflation and currently run as follows:
- Willful or Repeated Violations – $124,709 each.
- Serious, Other-than-Serious, and Posting Requirements Violations – The maximum penalty is $12,471 per violation.
- Failure to Abate – $12,471 per day.
For more information, companies and the public can refer to OSHA’s 28-page education booklet and call 800-321-OSHA (6742). OSHA provides many other educational trench resources, such as this video guide to soil classification and the process of trenching itself. The National Institute for Occupational Safety and Health offers prevention tips and invaluable disaster response information should the worst occur.
July of this year saw a national Safety Stand Down organized by the National Utility Contractors Association. That’s plenty of time to get ready for next year. In the meantime, their website offers more great resources about this critical issue. This 5-step checklist is another excellent go-to when walking around onsite. It can be used to make an informed assessment of trench safety and any steps that need to be taken.
Trust Mikula to be Fully OSHA-Certified
The safety of our team is a priority that’s kept our family firm growing since 1946. We’re happy to share this knowledge with our readers because it’s second nature to us. Mikula Contracting is fully OSHA-certified, and this is a badge of honor that means every member of our team knows the rules and is dedicated to keeping themselves and the people around them safe.
We’re also fully insured throughout the state of New Jersey and offer many other services besides excavation. Get in touch with us at the link below for more information on our excavation experience and commitment to sitewide safety.
Mikula Contracting, Inc., provides commercial and residential customers with a wide range of excavation, demolition, environmental, trucking, and soil materials services. For more information, call 973-772-1684 or email info@mikulainc.com
