Quick Start Guide Natural Gas Utilities

SECTION 03: KEY SAFETY MESSAGES

Cross Bore Awareness: Blocked Sewer Lines

Why Address This Issue? To minimize restoration costs, many utilities install underground pipelines and cables via horizontal directional drilling, a trenchless technique that avoids damage to sidewalks and landscapes. Unfortunately, some sewer laterals serving private property may go undetected when new utility lines are installed in this manner. As a result, a utility line can be bored directly through a sewer lateral in what is known as a “cross bore.” Cross bores can go undetected for months or even years, until a sewer backup develops and a property owner calls a plumber to remove the blockage or attempts to remove it without the help of a professional. Homeowners and plumbers frequently use mechanical rotary devices to clear sewer lines. These devices can damage a utility line that was unintentionally installed through a sewer lateral. Cutting an electric line may result in serious injury. If a natural gas line is cut, leaking natural gas may migrate undetected through the sewer line and concentrate in the home or nearby structures, posing a risk of fire and explosion. Utilities can reduce the risks associated with cross-bored natural gas lines by educating consumers, plumbers, drain cleaners, and public sewer agencies about how to respond when a cross bore is suspected or detected.

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Developing a Public Safety Communications Program