Establishing a Competent Person (CP)

Designating the right person to serve as the Competent Person (CP) on an excavation site is one of the most important steps you can take to keep work safe and compliant. OSHA defines a CP as someone who can recognize hazards and has the authority to fix them right away. In practice, this means assigning someone who not only understands excavation and trenching risks (e.g., soil stability, protective systems, and potential atmospheric hazards) but also feels confident speaking up and stopping work if unsafe conditions or behaviors are observed.

When establishing the CP, it’s imperative to look at both experience and training. Questions that should be asked include:

• Has the person worked with trenching or excavation before?
• Do they understand how to classify soil and choose the right protective system, like sloping or trench boxes?
• Have they been clearly given the authority to act?

An effective CP is someone that knows how to conduct regular worksite inspections, especially after weather changes or other events that could affect site conditions. The CP should also know they have full support to correct issues immediately. With the right person in place and properly supported, you’re setting a strong foundation for safer, more compliant excavation work.

Identifying excavation and trenching hazards

With the CP designated, the next essential step in excavation and trenching safety is to identify the hazards. These hazards aren’t always obvious at first glance, which is why taking the time to fully assess the work area before and during the job is so critical. Common risks include:

• Cave-ins,
• Hazardous atmospheres,
• Falling loads,
• Water accumulation, and
• Limited access or egress.

Even nearby traffic, heavy equipment vibrations, or weather changes can quickly turn a seemingly stable excavation into a dangerous situation.

Safety and compliance rely on workers staying observant and being proactive. The CP should be routinely walking around the site, and workers should continuously be on guard for warning signs like cracks in the soil, bulging trench walls, standing water, or changes in soil consistency. Equally important is to consider what’s happening around the excavation. Things like utilities, adjacent structures, or equipment activity can all introduce additional hazards. Everyone on the site should feel comfortable pointing out concerns if something doesn’t look or feel right. When hazard identification becomes an ongoing, team effort rather than a one-time task, problems and compliance issues are addressed before they escalate.

Determining soil classifications

Classifying soil might sound technical, but on an excavation or trenching site, it’s really about understanding how stable the ground is before anyone enters the excavation or trench. OSHA groups soils into three main types:

• Type A (the most stable) holds together well. A good example would be clay soil that is hard, compact, and not previously disturbed.
• Type B (less stable) might hold its shape somewhat, but you’ll notice it doesn’t stick together as strongly as Type A. Previously disturbed clay, silty soil, or gravel mixed with soil can fall into this category.
• Type C (the least stable) is loose and prone to collapse or crumble. Typical examples include sand, gravel, or any soil with water seeping through it.

The CP is responsible for making the final soil type determination, and they do so by looking at both visual clues and performing simple field tests. For example, they might check whether the soil is cohesive, look for cracks, or see if water is present. A quick “thumb penetration” or “dry strength” test can also give a good sense of how the soil will hold up. When in doubt, it’s best to classify the soil as Type C and use the more protective approach. The extra caution can mean the difference between continuing work or rescuing a buried worker.

The most important factor is remembering that soil conditions can change, sometimes quickly. What looked like stable soil in the morning can become much less reliable after rain or due to vibration from nearby equipment. As such, soil classification isn’t a one-and-done task but should be reassessed as conditions change. Choosing the right soil type is critical because it directly impacts which protective system you choose (e.g., benching, shoring, shielding). Taking the time to properly evaluate soil conditions helps ensure workers are protected from unexpected cave-ins.

Protecting workers from cave-ins

When it comes to protecting workers from cave-ins, the bottom line is using the right protective system for the conditions and making sure each is set up correctly every time. One of the most common approaches is sloping or benching, where the sides of the excavation are cut back at an angle to reduce the risk of collapse. This works well when you have enough space and understand the soil type, since softer soils require gentler slopes.

Shoring is another protective measure, which involves installing supports like hydraulic or timber systems to hold the trench walls in place. This is especially useful in tighter spaces where sloping isn’t practical.

Lastly is shielding, which is the use of safety structures, like trench boxes, to protect workers from cave-ins. Although shielding won’t prevent a cave-in, it does protect workers if one happens. Trench boxes are the most common go-to solution on many job sites because they’re reliable and relatively easy to use when installed properly.

Regardless of the method chosen, the key is matching the system to the soil conditions and site constraints, and making sure the CP is monitoring activities and conditions. Regular inspections, especially after weather changes or heavy equipment movement, are critical to ensure these protections remain effective throughout the project.

Making the most of training and communication

Training and communication on an excavation site is as important as assigning your CP and testing your soil. It really comes down to keeping things practical, consistent, and easy to understand. It’s not enough to simply give a tailgate talk and check the training box. Workers need to clearly understand the specific hazards they’ll face, especially cave-ins, hazardous atmospheres, and safe entry and exit. Tailoring training to the actual job site and in real-time, as well as walking through real-life scenarios helps the information stick with workers. Short, frequent refreshers such as toolbox talks before a shift can certainly go a long way in reinforcing expectations and keeping safety top of mind, but it shouldn’t be your sole training.

Maintaining effective communication is just as important once work is underway. Everyone on site should feel comfortable speaking up if they see a potential hazard or if conditions change, and there should be a clear process for reporting concerns and getting them addressed quickly. Daily briefings are a great way to cover changing conditions, like weather or soil stability, and make sure the whole crew is on the same page. When training and communication work together, they create a culture where workers are informed, engaged, and more likely to look out for one another. This not only helps prevent incidents before they happen, it keeps the worksite compliant as well.

Keys to remember: Excavation and trenching safety starts with assigning a competent person, correctly classifying soil, and choosing the right protective system. Regularly reassessing changing site conditions and ensuring workers are well-trained and comfortable speaking up about hazards are also key steps to significantly reduce risks and make compliance much more manageable.