Pipe bursting: It is a proven and routine method for pipe replacement, but the name alone conjures up images of danger. Injuries are not common, but like all forms of utility construction, precautions are necessary to make sure you are not creating risks for workers, the general public, or nearby utility lines and structures.

In its pipe bursting guidelines, updated in January 2012, the International Pipe Bursting Association lists three minimum qualifications for contractors doing pipe bursting:

• Training on the equipment from the pipe bursting system manufacturer
• Training by the pipe supplier on the handling, joining and installing of new pipe
• Proven installation of at least 50,000 linear feet of pipe

"Training, training, training," says Matt Timberlake, co-owner and vice president of Ted Berry Company of Livermore, Maine. He says the process of pulling or pushing the bursting head presents the most risk to personal safety. "You simply have to understand that a pipe bursting system is creating stored energy that is being transferred to a bursting head and pipe system and it is essential that personnel know where the energy is in the system at all times. An operator should know that if something does go wrong, where that energy is going to be displaced."

That's why, for instance, you should never get behind the equipment in a static system. In the rare case of a system or mechanical failure, that area could pose the highest risk to workers. "As soon as something changes, you have to be able to recognize it before it's a problem," says Timberlake. "A good operator can feel that in a system and can recognize when the energy is changing. It's about awareness of the risks and being able to make changes based on those changes."

Equipment operating manuals and industry sources list several common safety considerations:

• Locating nearby utilities
• Proper trench preparation and shoring
• Confined space precautions
• Proper use of hoses
• Inspection of hoses and connections
• Personal protective gear, such as eye and hearing protection, when necessary
• Winch safety, including a safety cage
• Lifting safety and proper use of lifting devices
• Safe pipe handling practices, including transportation, on-site storage, pulling and cutting/joining
• Proper equipment use

Timberlake says that, in his experience, the greatest risk is from equipment and from working in a trench or manhole. "You're using the trench shoring or the manhole to brace your equipment," he points out. "So you really need awareness of how the work you're doing may impact the conditions inside the trench."

Like most industrial processes, proper planning and a pre-job brief can ensure that people are safe and the pipe bursting is done in a way that protects nearby structures and equipment. A site safety plan is one of the steps included in the association's task list, along with a safety review for work crews.

Planning must also account for nearby utilities. The IPBA's updated guidelines state, "As a general rule, both horizontal and vertical distance between the pipe to be burst and the existing adjacent pipe should be at least two diameters of the replacement pipe."

The guidelines also list vibration as a possible risk to nearby utilities and structures when using the pneumatic process, but generally only within a few feet: "While ground vibrations may be quite noticeable on the surface close to a bursting operation, the levels of vibrations are very unlikely to be damaging except at very close distances to the bursting operation."

Timberlake agrees that damage from vibrations is something that must be considered, but damage is highly unlikely if the work is planned and executed correctly.