The new OSHA excavation standard generally applies to all excavations made in the earth's surface. The natural gas transmission and distribution industry has pointed out that certain working conditions in excavations in its industry are regulated by the Department of Transportation's office of Pipeline Safety and has argued that such working conditions are therefore not subject to the OSHA standard due to section 4(b)(1) of the Occupational Safety and Health Act. We have concluded that two subsections of the OSHA standard, 29 CFR 1926.651(g)(1)(iii), and .651(g)(2)(i) address working conditions that are covered by DOT standards and cannot be enforced by OSHA.