After a series of explosions across the country in the early 2000s, the danger of cross bores became a major issue in the industry. The term cross bore was coined to describe a situation where a gas pipe is inadvertently installed through a sewer lateral. This situation becomes a serious hazard if the sewer ever needs to be cleared using rotor cutting equipment that may damage the gas pipe, potentially causing a leak.
The cross bore problem was rooted in a system-wide lack of marked sewer lines. This was especially problematic in places like mobile home parks where owners did not know where the sewer lines were located and were not part of the One Call system that contractors use for identifying underground utilities. Crews had no way of locating the sewer lines and, in some cases, were prohibited from looking due to government no-cut policies. To make matters worse, a nationwide debate over assigning responsibility for marking sewer lines hindered a solution.
In one case study of 11,000 sewer laterals, 250 cross bores were discovered. Another case study found 24 cross bores in just four blocks. With more and more trenchless gas line installations done each year, the potential threat to life and property would only increase without public awareness and industry action. NPL led the way.
To NPL, this was a matter of “safety first” and doing the right thing. After taking immediate precautions to prevent cross bores in its own operations, NPL launched a “Call to Action” campaign targeting trade organizations, utilities and lawmakers. In addition to calling for change to the One Call laws for marking sewer lines, NPL pushed for laws making the entities who earned revenue from sewer facilities responsible for installing new sewer laterals with location devices like tracer wire or marker balls. NPL also advocated for educating plumbers, equipment rental stores and trailer park owners to look before rooting out sewer blockages. Over a time period of three years, NPL made a dozen presentations to different types of industry organizations, freely issued 3,000 copies of an informational DVD, wrote or contributed to numerous industry publications, and helped develop technologies to advance the cause.
By 2006, NPL had completed over 10,000 bore cards identifying the locations of sewer lines and gas service lines at its own job sites. And as a result of the Call to Action, NPL was instrumental to influencing industry practices and the laws that govern cross bores.