Since pipelines are generally buried underground, pipeline markers and warning signs are used aboveground to indicate the general location. These markers are placed when needed to indicate the presence of a pipeline, including river, railroad and street crossings and other heavily congested areas. These markers do not, however, show the exact location, depth, pressure or number of pipelines. Also, remember that pipelines do not always follow a straight path.
Be familiar with these permanent markers that indicate
Yellow flags are used to temporarily mark the general location of a pipeline in a proposed excavation area.