This notice proposes to establish a new subpart N-Conversion of Existing Pipeline to Gas Service, within Part 192 of Title 49, Code of Federal Regulations. The Materials Transportation Bureau (MTB) has been petitioned by the Interstate Natural Gas Association of America (INGAA) to establish this new subpart. Since Part 192 presently does not specifically address the subject of conversion, the current OPSO interpretation is that an. existing pipeline in other service may be used to transport natural and other gas if it complies with § 192.13, or if a petition for waiver from compliance with one or more of the Part 192 regulations as provided under section 3(e) of the Natural Gas Pipeline Safety Act of 1968 (49 U.S.C. 1672(e)) has been approved (e.g. Cities Service Gas Company has petitioned MTB for a waiver from certain sections of 49 CFR Part 192 so that a crude oil pipeline can be converted to a natural gas transmission pipeline). Section 192.13 requires that, "No person may operate a segment of pipeline that is readied for service after March 12, 1971, or in the case of an offshore gathering line, after July 31, 1977, unless that pipeline has ben designed, installed, constructed, initially inspected, and initially tested in accordance with this part." and that, "No person may operate a segment of pipeline that is re- placed, relocated, or otherwise changed after November 12, 1970, or in the case of an offshore gathering line, after July 31, 1977, unless that replacement, relocation, or change has been made in accordance with this part.' Because most of the facilities that would be converted to gas service were constructed prior to the controlling dates of §192:13 in accordance with specifications and procedures applicable at the time they were installed, they cannot realistically comply with the design, construction, initial inspection, and initial testing requirements of Part 192. Therefore, the only alternative is to apply for numerous waivers from these requirements. In support of its petition INGAA asserts that it Is not logical that OPSO or the operator be burdened and delayed by the processing of a large number of waiver requests especially if a regulatory procedure of general applicability can be developed which would permit expeditious conversion while at the same time providing the necessary levels of safety. INGAA further asserts that the adoption of such a procedure would greatly enhance the ability of the pipeline industry to deliver this much needed energy source to the public in a timely, economically, and environmentally sound manner, all of which is in the national interest.