Hamilton Kent Blog

9 ways to prepare a safe excavation site

Main Image

A lot can go wrong if you’re not implementing the correct safety procedures at a job site—from fingers being pinched between concrete pipes, to cave-ins in the trenches. Even with proper planning, the risks are there.

So how do your prepare your personnel to keep everyone as safe as possible? Read the steps below before starting your excavation:

1. Always use the right Personal Protective Equipment (PPE)

PPE will change depending on the level of risk at a job. This will include varying levels of eye, head and foot protection. It’s up to the employer to not only provide proper PPE, but to also train workers how to properly use, care, and maintain them. Training should include: when and what PPE is necessary, what the PPE's limitations are, and how to care for PPE.

2. Train, train and train some more

Training is essential for the construction industry. Contractors should not only personally train personnel working in the trenches, but also rely on their suppliers to train workers on how to properly install the products they are supplying. Most concrete pipe and structure suppliers are able to provide someone to demonstrate how to properly install pipes, manholes or gaskets.

There are also a number of Occupational Health and Safety Association (OSHA) courses that job site supervisors, and workers, are required to take before showing up to the job site. You can find them here.

3. Give your site a hazard assessment 

Along with training, before workers arrive at a job site, a hazard assessment of the workplace should be performed. This allows employers to have more control over physical and health hazards on the job site. Hazards could include rain, ice, contaminated soils, sewage effluent, overhead powerlines and underground utilities.

4. Display clear project specific emergency procedures

Should an emergency happen while excavating or installing pipes or precast structures, there should be an emergency plan implemented and clearly displayed for all workers on site. This should include what to do in both occupational medical emergencies (heat stroke, exposure to pollutants, amputations, trench cave-ins etc.), and non-occupational medical emergencies (heart attacks, or other pre-existing conditions).

With conspicuously displayed emergency procedures, the risks will be greatly reduced and the response from your workers in the event of an emergency could potentially save lives.

5. Personnel should know about enter and exit points

In the event of an emergency, it’s extremely important to have clearly marked enter and exit points in your trench. Workers should know how to properly enter and exit an excavation, and exits should be properly supported by trench walls so as to not cause a cave-in. Proper access points include ladders, steps or ramps.

6. Assess soil structural requirements and environmental hazards

A number of factors come into play when assessing the structural requirements of your trench walls. These include the characteristics and water content of the soil, depth and width of your excavation, weather conditions, and vibration from construction equipment or traffic.

With all of these things in mind, the appropriate sloping, shoring or shielding requirements should be measured and approved by an engineer. If a support system is required, it should be engineered and determined, along with what equipment will be needed, before the start of an excavation. With all of these precautions in place, you will be able to prevent excavation walls from collapsing.

7. Be careful of equipment hazards, debris and dirt

After your trench walls are properly supported, precautions also need to be taken throughout the duration of your project to keep workers safe. This means keeping the trench free of water, and reassessing after rain, snow, or ice melts to ensure there is no change in the soil. Equipment, debris and excavated soil should stay more than three feet (one meter) away from the edge of the trench. This includes keeping moving vehicles away from the walls of the excavation.

With the unloading of pipes and concrete structures, this should be done on a level site, ensuring that workers are out of the path of the product. And handling of these concrete products must be done carefully to prevent injury to personnel who could inadvertently find their way in the path of your equipment. If the product is suspended by a cable, equipment operators and workers on the ground need to be cautious of loads that could swing during movement.

8. Keep traffic in trench low, but not too low

A worker should never enter into a trench unless there is another worker present outside of the trench. If any emergencies happen, this ensures that there will be someone present who can respond based on the project-specific emergency procedures.

At the same time, traffic should stay low in the trench. Fewer people means fewer trips or falls in the narrow workspace between the pipe and the trench walls. For box culvert installations, there should be 3 to 4 workers in the trench: 1 to 2 workers inside the culvert to watch for alignment and a couple outside the culvert to direct it into place. Pipe installations need even fewer: 1 worker at the back of the pipe for alignment, and 1 worker at the front to direct the installation equipment operator.

9. Limit how much trench is open at a time

Limit the amount of trench open at any given time to 50 feet (15 metres), and try to close the trench as quickly as possible to keep both workers and equipment from falling in.

This means cast-in-place concrete structures will inevitably be less safe than any type of prefabricated structure (like precast concrete) because it takes time to setup formwork, pour concrete and allow for proper curing. Using rubber gaskets and connectors will also shorten the amount of time the trench is open due to fast installation, and no time needed to allow for mortar connections to cure.

Keep workers and the public safer from injury on site on your next project. For more information on site-safe products, please feel free to talk to one of our reps here.