Trenching and excavation work poses many hazards such as cave-ins, equipment struck-by incidents, potential falls, and striking underground utilities. Hazards posed by striking buried underground utilities include property damage, injury, electrocutions and even explosions.
Dangers of Utility Strikes
After investigating hundreds of utility hits and spending so much time on root cause analysis, we know the real damage that can be caused by not calling 811 before you dig. Making assumptions will get you in trouble every time.
Striking underground utilities can lead to serious consequences, including:
- Contact with energized electrical lines resulting in electrocution
- Ruptured gas lines causing fires or explosions
- Damage to water or sewer lines leading to flooding or contamination
- Service disruptions affecting homes, businesses, and emergency services
The biggest assumption that we saw time and time again was assuming that all lines in the area are buried at least 18-inches deep. Reason for the assumption? Because, in most states, all lines are "supposed" to be buried at least 18-inches deep. After dozens of line hits all over the country, are all lines buried at least 18-inches deep because they are supposed to be? NO.
Depth can vary due to changes in grade over time, improper installation, previous excavation work, and soil erosion.
Lesson learned? Any dig, any depth, always requires a call to 811 a few days before the project.
OSHA Requirements for Utility Locates
In order to prevent these potential hazards it is important to follow all applicable excavation and trenching requirements. In addition to OSHA rules, workers should be aware that there are many specific state, municipal, or local rules for Call Before You Dig where the work is being done.
OSHA Standard 1926.651(b)(1) states that the estimated location of utility installations, such as sewer, telephone, fuel, electric, water lines, or any other underground installations that reasonably may be expected to be encountered during excavation work, shall be determined prior to opening an excavation.
Call 811 Before You Dig
To learn more about Calling 811 including 811 in your state, visit the Call 811 website. Call 811 has an interactive state map to make it easy for you to find information about 811 requirements in your area. They have information for homeowners, contractors, farmers and ranchers.
- Before trenching or excavation work takes place, workers must estimate the location of any buried underground utilities by contacting the appropriate service.
- Each state has specific guidelines for call before you dig.
- Call 811 from anywhere in the country a few days prior to working on excavations, trenching or digging and the call will automatically be routed to the local one call center.
OSHA Standard 1926.651(b)(2) says that utility companies or owners shall be contacted within established or customary local response times, advised of the proposed work, and asked to establish the location of the utility underground installations prior to the start of actual excavation.
Safe Digging Practices Around Utilities
Always wait the specific time required by the locate service. Always respect the markings and flags placed by the locating service.
Probe, hand dig, and/or pot hole using shovels when approaching the painted or flagged areas.
Use extra caution within the tolerance zone (the area on either side of the marked utility). Mechanical equipment should not be used until the exact location of the utility has been confirmed.
Even when utilities are properly marked, other hazards still exist during trenching and excavation work. Workers should remain alert to:
- Changing soil conditions that could lead to cave-ins
- Equipment operating nearby that could create struck-by hazards
- Open excavations that present fall risks
- Previously unmarked or abandoned utility lines
Following proper procedures, avoiding assumptions, and always calling 811 before digging are critical steps in preventing serious incidents and keeping workers safe on the job.
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