Trenchless technologies, such as directional drilling, are increasingly used in urban areas to install new underground utility lines. While rare, in some cases a cross bore may be created when an underground utility is unknowingly installed through an unmarked sewer line. Cross bores can lay dormant for months or even years with their exact locations unknown. Often, the first sign of a cross bore is a sewer blockage that may cause the backup of waste water in your home or yard.
To clear blockages, plumbers typically use a mechanical rotary tool, or root cutter, to clear a sewer line. This process can damage a natural gas line that has been unknowingly bored through a sewer line. Natural gas can then migrate through the sewer line into a connected structure, including one without natural gas service, and create the potential for a natural gas accumulation and possible ignition.
Do you have a blocked sewer line? If so, the cause may be a cross bore.
Before clearing a sewer line with a mechanical cutting tool, always Call Before You Clear.
- Stop all work.
- Do not attempt to clear the blockage with any mechanical cutting device.
- Immediately call 811 and request an emergency ticket, referencing the key phrases, Sewer Clearing or Cross Bore.
- By referencing Sewer Clearing or Cross Bore in your 811emergency locate request, a Washington Gas representative will immediately be dispatched to locate the natural gas lines on your property to help determine if there is a conflict between natural gas and sewer facilities.
- If a natural gas line cross bore is discovered, Washington Gas will immediately respond to correct the cross bore before you clear the sewer line.
- Washington Gas does not charge for any of these services.
Washington Gas Cross Bore Program
Cross bore programs can be found at many gas utilities around the country, necessitated by industry-wide safety concerns. In 2008, Washington Gas began a research effort to identify areas where trenchless technologies had been utilized. Ultimately, this effort produced a population of addresses that were determined to be potentially at risk.
To date, approximately 47 cross bores have been documented system-wide. Consequently, Washington Gas has developed a multi-pronged Cross Bore Program consisting of six main components:
- CCTV of Legacy Installations
- Proactive “Call Before You Clear“ Program
- Continual Review of Trenchless Procedures
- Installation of Excess Flow Valves (EFVs)
- Communication & Outreach
Industry research has proven that each of these components is useful in analyzing and mitigating cross bore risk. Washington Gas has entrusted skilled Hydromax USA technicians to perform sewer main and lateral sewer inspections on our behalf. The efforts of Hydromax USA help Washington Gas grow and expand cross bore knowledge as innovative technology is developed and additional information is discovered. Ultimately, allowing the Cross-Bore Program to contribute to the Washington Gas safety promise.