This amendment revises the existing requirement in § 192.707 for marking the location of gas transmission lines and establishes new marking requirements for gas distribution mains under that section. The purpose of this amendment is to alleviate a major cause of failures in gas pipelines-interference with/pipelines by persons outside the gas pipeline industry conducting excavation-related activities. Installation of line markers in accordance with these revised requirements should increase the likelihood that outsiders will seek assistance in locating underground lines before excavating. Also the revised requirements should influence operators to encourage State or local governments to adopt programs for preventing interference with underground pipelines.