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Legacy Cross Bore - Identifying and Eliminating

Elimination of damage, injury and death to a high degree of certainty are the typical primary goals of a Legacy Cross Bore Elimination Project.

Legacy Cross Bore Flow Chart.jpgLegacy Cross Bore Elimination Project Flow Chart is available.

SEE full document for Leading Practices for Cross Bore Risk Reduction.
Full Introductory Leading Practices Presentation.

Additionally and NOW available, CBSA has developed documents for Legacy projects:


Also available to compliment the above "Leading Practices for Cross Bore Risk Reduction":

Sample Contrct for CBSA Legacy Inspection Contracts

Since at least 1999 elimination of cross bores from existing and new construction have become a growing priority for operators of natural gas distribution lines.

In 1999, sewer authorities complained that newly constructed sewer lines were being damaged when gas lines were installed. Gas installers complained that sewers were not located.

Image of Kentucky PSC Ruling 1999Owners of gas distribution lines complained that sewers were not marked. Click here to see Kentucky PSC vs. LG&E & Goshen Utilities, February 9, 1999 ruling.


GPS & CCTV with GIS MappingCCTV, GPS, GIS Integration Project Slide Presentation, courtesy Cues, Inc. -(2.9 Mb, PDF format)


Since trenchless techniques such as HDD, horizontal directional drilling, percussive moles and plowing, have been widely used as well for several decades there are potentials for thousands of existing cross bores of sanitary/storm sewers by gas distribution lines and other utilities. Trenchless technologies ( have the advantage of being minimally disruptive to the surface, yards, roads, driveways, traffic and trees.


On a large legacy project, there has been as many as 430 cross bores found nearly 200 miles. Expected U.S. average is 0.4 cross bores per mile of mainline.

Definition of Legacy Cross Bore

A cross bore that was created during prior construction activities.

Class 1 Cross Bore Illustration

Class 2 Cross Bore Illustration

Legacy Cross Bore Inspection Project

A project that has the focus to find and eliminate legacy cross bores.

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