Fortunately, we had all the lines underground identified twice for our last phase of landscaping the entire outside. The second scan revealed the gas line underneath the Douglas Fir stump. We had two of those trees removed for Phase Three. The tree stump remover chewed up remainders but gave a margin of error to avoid hitting the line. That was done by hand, chainsaw, and tamping bar.
Before we knew it, there was a loud hiss coming from the tamping bar that was jammed through the stump into the awaiting gas line. Two fire trucks with their crews; the chief AVISTA supervisor with gas measuring meter; and five company trucks arrived over the next 30 minutes. Trenches were dug trying to locate the line. An AVISTA Back Hoe assisted in the underground search for a line later determined to be hidden in PVC conduit installed in 1987. Meanwhile, gas was gushing into the soil and air. A strong breeze helped blow the danger away.
This is serious stuff. The neighborhood was isolated by the two fire trucks blocking the road. The off valve for gas lines is to dig down deep to locate the line; crimp it; and then repair the downline damage. You call 911 to start the process.
It was helpful that I had sat on the Fire District Board so that I knew some of the crew. It was also helpful that the AVISTA Supervisor had just married a good friend of ours. Gas Leaks require immediate repair. The job was done inside 4 hours on that Friday afternoon. The Back Hoe helped remove the offending stump.
That gas line is now safely buried under the stair steps leading down to the back yard.