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. This is called a cross bore. Cross bores can occur between different types of underground utilities, including the intersection of a gas line or electric line and a sewer line or water 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, such as hydraulically boring or directional drilling. Before using such technology, excavators are required to call 8-1-1 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 Best Practices, 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 can develop, 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 will cause damage to 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.
Inquire with the owner, occupant or building maintenance individuals to determine the location of sewer facilities, such as clean outs. Ask the owner or occupant 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 suspect or determine the blockage is caused by a cross bore:
- Do not attempt to clear the blockage with any mechanical device.
- Contact and get help from the utility operator(s) that may be involved. Valley Energy can be contacted 24 hours a day by phone at 1-800-998-4427 or 570-888-9664.
- 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 you suspect a natural gas leak by smelling, seeing or hearing gas escaping:
- Leave and instruct others to evacuate the area
- Call 9-1-1
- Contact Valley Energy at by phone at 1-800-998-4427 or 570-888-9664.
- Do not operate any equipment
- Eliminate sources of ignition, do not turn on or off lights/electrical devices.
- 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
More information on cross bores, including a helpful video, can be found on the PA One Call website by clicking the link below.