Cross Bore Safety

You must call 811 at least three, but no more than 10 days prior to performing any type of excavation, digging or boring activities in Pennsylvania. And, did you know you should also call 811 anytime you are called to clear a blocked sewer line?

A blocked sewer line may be the result of another utility line (i.e. gas, electric, telecommunications, water) that has been bored through the sewer line. Attempting to clear this type of blockage can result in a serious accident, involving loss of life, injuries, and significant property damage.

Please follow these precautionary measures to help prevent accidents:

Utilities and their contractors are increasingly installing underground utility lines using trenchless technology. Before using such technology, excavators are required to call 811 and request the marking of underground utility lines in the area of excavation. After existing utility lines are marked, excavators are required to determine the precise location of these utility lines before they bore over, under or in close proximity to the lines. If sewer lines are not marked or the excavators do not follow the Horizontal Directional Drilling Good Practices Guidelines, the minimum standard in Pennsylvania, excavators may end up “boring” through the sewer lines and leaving a utility line (gas piping, electric, or telecommunication cables) inside the sewer line without even knowing it.

The presence of a utility line in a sewer line (known as a “cross bore”) can go undetected for months, even years. Eventually, a sewer backup develops and a plumber is called to remove the blockage. It is a common practice for plumbers to use a mechanical rotary device to root out or clear the blockage. The process almost always damages the utility line that was bored through the sewer line. If an electric line is cut, the plumber runs the risk of electrocution. If a gas line is damaged, gas can migrate through the sewer lines into homes and buildings and result in a major accident that may involve deaths, injuries and significant property damage.

Before starting the process of cleaning out a sewer line remember to:

• Call 811 so facility owners can mark the location of their underground utility lines at the property.
  
• Inquire with the owner, occupant or building maintenance people to determine:
  • The location of the sewer facilities such as clean outs.
  • If there has been any recent excavation to install utility lines.

If the markings from existing underground utility lines cross the path of the sewer line, it may be a cross bore that is causing the blockage.

Use a camera to identify the location of the blockage. If the evidence of recent excavation or the marking for a utility line is the same distance from the building as the blockage, there may be a cross bore causing the blockage.

If you reasonably suspect or determine the blockage is caused by a cross bore:

• Do not attempt to clear the blockage with a mechanical device.
• Contact and get help from the utility operator(s) that may be involved.
• After the utility comes out to mark their line, hand or soft dig in the area where the blockage and or the cross bore may exist.

If a Cross Bore is Discovered:

• Stop all work
• Contact the utility operator involved if not already on site
• If you suspect a natural gas leak by smelling, seeing or hearing gas escaping:
  
  
  • Leave and instruct others to leave the area
  • Call 911
  • Contact the gas company for the area
  • Do not operate any equipment
  • Eliminate source of ignition
  • Do not operate any pipeline equipment or facility
  • Do not proceed with your work until the utility involved informs you it is safe to do so