"Cross-bores" occur when gas lines intersect with sewer lines, and can cause blockages and even natural gas leaks. A large California utility is committed to finding and relocating cross-bores. The company has performed 140,000 of ~150,000 inspections needed in San Francisco, but the remaining 10,000 sites are the most challenging and many have few or no records.
The company's cross-bore identification process is intensive and manual, using existing records (where present), sewer camera inspection, potholes, and open trenching as a last resort. The current strategy is expensive and time-consuming, so the company engaged Exodigo to investigate suspected cross-bores. Exodigo was asked to identify lines that needed potholes to minimize trenching and test Exodigo's cross-bore prevention, identification, and relocation capabilities.
Date:
November 2022
Location:
San Francisco, California
Acres:
Scan Days:
Platform:
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Exodigo's scan identified all utilities, including drainage, electric, communications, gas, and water.
The scan detected five intersections between sewer and gas lines on this densely populated residential street in San Francisco. However, of those five lines, three were not at risk of cross-bore because the lines were more than five feet apart in depth (a detail that was not shown on the records).
By identifying line depths using multi-sensing technology, 3D modeling, and artificial intelligence, Exodigo enabled the utility to focus investigation efforts on the two lines that were actually at risk of cross-bore. The result was a 60% reduction in invasive methods required to reach this conclusion.
Additionally, Exodigo detected an electric line that was shown at a 90-degree angle to the street on the records but was found during scans to be curved instead, providing the utility with more accurate information for future capital projects.
The Exodigo team worked with the utility to calculate a cost-savings model comparing Exodigo's methods to current workflows. Even at the scale of a single residential parcel, Exodigo's methods save costs, but for a large bundle of 2000 parcels, the results are dramatic, saving 39% in costs and reducing time by 24%.
Cross bores are a threat to pipeline safety and should be considered in operators’ distribution integrity management plans. Regulators and operators need to consider cross bores as a known threat to determine if additional measures are needed."
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