At an average of 13,000 miles driven per year, if only 10,000 of these 1994 passenger cars were converted into natural gas vehicles, that would represent a reduction of more than 200 tons of air pollution. Another important benefit of natural gas is its safe and efficient transmission. High- pressure pipelines can safely transmit natural gas underneath city streets or across long stretches of open country. Gas companies use modern technology, stringent policies and constant surveillance to ensure the safety of their communities. To begin with, pipes are thoroughly inspected before installation.
Inspectors use x-ray equipment to verify the safety of each pipe and weld.
The pipes are also treated with a special coating that prevents corrosion. The law requires that natural gas pipelines be buried at least three feet deep in the ground. However, pipes in San Diego are always buried at a minimum depth of four feet. Located several feet above the pipe, a warning marker indicates the pipe's presence below. The marker is a highly-durable, bright yellow tape that serves to prevent excavation crews from accidentally damaging the pipe.