What are Cross Bores?

cross bore trenchless Jul 13, 2021

Cross-bores first entered policy and public awareness in 1976 when a sewer drain cleaner hit a cross-bored gas line in Kenosha, Wisconsin. The strike caused a gas explosion that resulted in two deaths, four injuries, and the destruction of a home. While this tragic incident brought awareness of cross-bores, many remain undetected if they don't cause obvious blockages. 

What is a Cross Bore?

Cross bores are unintended intersections of utility lines caused by trenchless excavation techniques. Trenchless, or horizontal drilling, is a technique to install or replace utility lines without the need to excavate a trench. The benefits of trenchless technology are growing in step with the rapidly improving technology, but there are a few cascading consequences of its increased use.

What Makes Cross Bores so Dangerous?

Undetected cross bores can cause backups in the sewer lateral or damage the structural integrity of a pipe. The symptoms of this damage can mirror the common effects of a lateral clogged with debris, broken from shifting soil, or obstructed by tree roots.

Homeowners experiencing the seemingly clogged drain often call a drain cleaning service or plumber to clear it. If the drain cleaner or plumber isn't able to get a camera far enough down the line to see the cross bore, or if a camera scope isn't performed at all, there's a risk that the drill used to clear debris will instead strike an active gas line, putting the lives and homes of anyone in the vicinity at risk. 

The replacement of aging pipeline infrastructure across the United States, combined with the increased use of trenchless excavation techniques, has created a dangerous cocktail for potential cross bores

New pipeline installation is happening in many states and updating aging pipeline infrastructure by using trenchless excavation technologies has increased the potential for accidentally (and unknowingly) puncturing existing infrastructure while drilling to install new pipelines.

Here's what Mike Iadanza of USIC and Brian Clem, formerly of Bloodhound, had to say about cross bore risks:

“With such a high demand for utility upgrades and new installations in developed areas, there is also a demand to minimize disruption to homes and businesses within the scope of these projects. Traditional trenching certainly minimizes the risk of an unknown utility strike, but the mess and disruption of using this method is often seen as an unacceptable solution. However, while trenchless excavation or horizontal directional drilling is a valuable and effective method for installing new utilities without the mess and disruption that can occur with traditional trenching, it can result in undetected utility strikes. Sewer lines are especially susceptible since, typically, there is no immediate loss of service nor visible feedback (i.e. water spraying out) to the operator that a strike has occurred. This damage can remain undetected for days, months or even years, depending on the specific circumstances.”
- Mike Iadanza of USIC and Brian Clem of Mason Private Locating, dp-PRO Magazine


Leading Practices on Cross Bore Safety

Learn More about Cross Bores and the latest technology, policies, and techniques to prevent them by attending the 2022 Leading Practices on Cross Bore Safety Course.

Watch the FULL 2021 Leading Practices on Cross Bore Safety Course HERE


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