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U.S. Department of Transportation U.S. Department of Transportation Icon United States Department of Transportation United States Department of Transportation

Interpretation Response #PI-78-0108

Below is the interpretation response detail and a list of regulations sections applicable to this response.

Interpretation Response Details

Response Publish Date:

Company Name:

Individual Name:

Location State: TX Country: US

View the Interpretation Document

Response text:

PI-78-0108
November 09, 1978

Mr. Roy R. Die
Exxon Pipeline Company
Post Office Box 2220
Houston, Texas 77001

Dear Mr. Die:
Thank you for your October 13, 1978, letter to Secretary Adams notifying us of your intent to place
in service your pipelines from South Pass Block 93A and Mississippi Canyon Block 268.

Section 195.6 does not require notice in the case of multi-phase gas and oil flow because, as
stated in Section
195.1(b)(1), Part 195 does not apply to a commodity transported in a gaseous state. However, as
your letter indicates, since the pipelines will be carrying natural gas and crude oil they will be
subject to 49 CFR Part 192 as well as Part 195. Thus, they must comply with the applicable
requirements of both Parts and, in the event of conflict, the more stringent requirement of either
Part.
Sincerely, Cesar De Leon Associate Director for
Pipeline Safety Regulation
Materials Transportation Bureau
October 13, 1978
Exxon Pipeline Company
Post Office Box 2220
Houston, Texas 77001
Mr. Brock Adams
Secretary, Department of Transportation
Washington, D. C. 20590
This letter is Exxon Pipeline Company's notice of its intention to include natural gas as a
transported commodity along with crude oil in the captioned offshore pipelines located in the Gulf
of Mexico. The purpose of this notification is compliance with the requirements of DOT section
195.6, Transportation of Certain Commodities.

These pipelines were recently constructed in conformance with Title 49 CFR Part 195, Minimum
Federal Safety Standards for Liquid Lines. During construction it was learned that natural gas
transportation in multiphase flow would be required from both South Pass Blk. 93A and Mississippi
Canyon Blk. 268.

These offshore lines are in federal waters and do not impact in a safety sense on the general
public, or to a significant degree on Exxon employees. The most pertinent aspect of the operation
of these pipelines is the potential impact on the environment. Thus, the containment, repair, and
clean up of the crude oil constituent of the multiphase mixtures should be the principle concern of
both the DOT and the EPA. In addition, even though the projected (gas/oil) ratios are high the
pipelines are extensions of an extensive existing crude oil pipeline system and from a practical
sense they should be operated and managed as liquid pipelines.

Based on the above considerations, these multiphase pipelines will be operated and reported in
accordance with Title 49 CFR Part 195. Operation of the South Pass line is scheduled to begin about
November 1, 1978 and the Mississippi Canyon line should begin operation in April, 1979. As the
design, II-testing and operating conditions for these lines meet the most stringent regulatory
requirements of both the gas and liquid regulations, we assume the 90 day notice set forth in
Paragraph 195.6(a) does not apply.
Roy Die

Regulation Sections

Section Subject
195.1 Which pipelines are covered by this Part?