Hidden Dangers of Cross Bores

With the increasing use of horizontal directional drilling for installing underground utilities, the risks of cross bores are increasing at an alarming rate. If the drilling process doesn’t go as planned and utility lines intersect, it can create dangerous situations, particularly when gas lines are involved.

What is a Cross Bore?

A cross bore occurs when a newly installed utility line unintentionally intersects an existing underground utility, such as a gas or sewer line. Although rare, this often happens with trenchless technology installations, such as horizontal directional drilling. While the use of a horizontal directional drill is beneficial for minimizing surface disruption, it increases the risk of cross bores, especially if public underground utilities are not accurately mapped.

Why Are Cross Bores Dangerous?

A cross bore poses a significant danger to homeowners, especially when a gas line is accidentally installed through an underground sewer line, creating a blockage. This can lead to a buildup of gas in the sewer system, which poses a serious explosion risk if a spark is introduced, such as when a plumber attempts to clear the blockage using a powered auger. Even without immediate ignition, the gas can leak into homes causing dangerous exposure to toxic fumes. Additionally, the blocked sewer line can result in wastewater backups, leading to property damage, health hazards, and expensive repairs.

Signs of a Cross Bore

Identifying a cross bore is challenging without specialized equipment. However, here are some warning signs that could suggest the presence of a cross bore:

• Unexplained sewer backups: This could indicate that another utility line has punctured a sewer pipe causing a backup.
• Gas odors: If a gas line intersects with a sewer, gas may leak into the sewer system, resulting in a detectable rotten egg odor.
• Recent directional boring near your property: If you know that a new utility was installed near your home or business, it’s worth it to have a professional with a sewer camera inspect your lines if you experience sewer issues afterward.

What Should You Do If You Suspect a Cross Bore?

If you believe you have a cross bore situation, act immediately. Vacate the area before using your phone or any electrical devices. Once at a safe distance, contact the gas company and 911 to report your suspicion. Once the gas supply line is shut off and the area has been cleared by the professionals, it is time to contact a plumber to inspect your sewer line using a camera or ground-penetrating radar. These tools can help confirm whether a cross bore exists without causing further damage.

By staying informed and taking proactive measures, you can significantly reduce the risks associated with cross bores and keep your home and community safe.