Colorado Public Works Journal, Fall/Winter 2022

58 Colorado Public Works Journal INSIDE CCA Moses Alvarez Excavation Hazard Training Takes the Forefront On October 5, 2022, at the Adams County Fairgrounds a crowd of 500 construction personnel converged for an opportunity to discuss the unique hazards that exist when there is an excavation on a construction site. Among these hazards the chief concern is the event of a cave-in. Most severe injuries and fatalities that occur within an excavation are due to cave-ins. The reason for this is simple: DIRT IS HEAVY! A cubic yard of soil (27 cubic feet) typically weighs close to 3000 pounds. But what is a cubic yard? Unless someone has worked within the industry and understands this term it may be a relatively unknown value. A simple way to think about it is that a cubic yard is about the same size as a washing machine. Although this is a simple comparison it needs further clarification. According to The Home Depot website: “A large capacity washing machine can weigh almost 230 pounds.” This is where the comparison can be very misleading. Anyone that has ever had the task of moving a washing machine up a flight of stairs thoroughly understands how dangerous it would be if something went just wrong enough and a person found themselves in the path of a washing machine tumbling down the stairs. Now take that situation and multiply it by 10 for a closer comparison to what happens when a 3-foot-wide, by 3-foot-long, by 3-foot-deep section of a trench collapses into an open excavation. If anyone is in the path of this type of collapse, their survival is questionable at best. Cave-in prevention must always be a main priority for anyone working within an excavation. While cave-ins are the leading cause of severe injuries and fatalities during excavation operations there are many others. Another very dangerous circumstance is when an underground utility is struck while excavating. The severity of a utility strike can vary greatly depending on what type of utility is hit. When a communication line is hit there may not be immediate hazards for individuals working within the area, but it can mean a major service disruption for those nearby. This may be an inconvenience to some, but tragic to others if communications were down and emergency services were delayed due to the strike. On the other hand, if a high-voltage electrical line or a high-pressure natural gas pipeline is hit there could be grave consequences for those working onsite and anyone residing nearby. When a waterline is struck there is also immediate danger because the saturation of soil at the bottom of an excavation almost always results in a cave-in of the soil above. Most people don’t realize that toxic gases tend to seek out low elevations because of their air density. This means that an open excavation is the perfect location for toxic gas to linger. This may initially seem unlikely, but when the fact that practically all sewer systems contain traces of toxic gases is better understood than anyone can realize it may not be a rare occurrence at all. This is one of the main reasons that an emergency egress point is required no more than 25 feet of individuals working in an excavation that is deeper that 4-feet. The Occupational Safety and Health Administration (OSHA) provides free resources that warn individuals about all the potentially hazardous situations that exist when working within and around an excavation. Any employer that completes excavation work is required by law to train their employees how to recognize and eliminate those hazards. Unfortunately, from January through June of this year there have already been 22 fatalities involving trenching and excavating across the nation. This is very disturbing considering that in all of 2021 there was a total of 15 fatalities. If the occurrence of these incidents continues to increase at this rate it could mean dozens of people losing their lives just this year. Colorado has seen several of these tragedies reported by local news broadcasters over the last several years. The importance of properly communicating excavation hazards and avoiding their catastrophic outcomes was at the heart of the 2022 Colorado Trench Safety Summit. Attendees of the Summit were also given the opportunity to hear from three individuals of the Denver-Metro area’s technical rescue fire departments. While these three presented details regarding their response to some of the local incidents that ended in workers being caught in a trench collapse the tone in the room stiffened. All three of the fire department officers made it clear that the majority of the time they arrive rescue is no longer a feasible option because even if they are able to reach the location within minutes of the incident they are already too late. When an individual that has thousands of pounds of soil land on top of them they typically sustain significant physical injury, but they are also normally unable to breathe from just a few moments after the collapse. So even after two or three minutes that individual’s chance of survival is extremely low. This is why responders may have to determine that an individual is not able to be rescued and change their tactics to recovery of a dead body instead. This may seem dispassionate, but this is exactly the reason prevention of these incidents is the most important issue and needs more focus. The extra time it takes to complete the job the safest way possible is the same few precious minutes someone has before they die due to taking a shortcut and not following best safety practices. Please urge everyone you know that works in or around excavations to follow OSHA and industry standards to prevent these tragedies that can occur. Safety first, safety always! Moses Alvarez is Director of Training at CCA and can be reached at