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Interpretation Response #PI-07-0102 ([Enterprise Products Company] [Mr. Joel E. Kohler, P.E.])

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

Interpretation Response Details

Response Publish Date:

Company Name: Enterprise Products Company

Individual Name: Mr. Joel E. Kohler, P.E.

Location State: LA Country: US

View the Interpretation Document

Response text:


U.S. Department of Transportation
400 Seventh St. S.W.
Room 2103
Washington, D.C. 20590

Pipeline and Hazardous Materials Safety Administration

April 6, 2007

Mr. Joel E. Kohler, P.E.
Manager Pipeline Compliance
Enterprise Products Company
P.O. Box 9
Gonzales, LA 70707-0009

Dear Mr. Kohler:

This is in response to your e-mail of August 12, 2004, renewing your earlier request for interpretations of 49 CFR 192.5 and 192.619. You asked for clarification of how the Pipeline and Hazardous Materials Safety Administration (PHMSA) considers certain buildings and persons in class location studies and for the specific meaning of the word "prevalent" in 49 CFR 192.5(b)(4). You also requested clarification on the use of class location factors in revising maximum allowable operating pressure (MAOP).

You ask, "For those areas within 100 yards of the pipeline, is the intent of 192.5(b)(3)(ii) to include, as Class 3 locations, building(s) such as a convenience store, i.e. Circle K, 7-11, etc., and video poker truck stops where persons may frequent on a daily basis?" You add, "What is the interpretation under 192.5(b)(3)(ii) as to the 20 persons, such as all 20 present at one time or cumulative throughout the day?"

Yes, the intent of § 192.5(b)(3)(ii) is to include convenience stores, video poker truck stops and similar buildings in Class 3 locations where these facilities lie within 100 yards of the pipeline. Under § 192.5(b)(3)(ii), the 20 or more persons must all be present at the same time. However, this does not require the continuous presence of 20 or more people. For example, the minimum requirement is met if 20 people are present at a convenience store at any one time during the day.

You ask, "What is the definition and intent under 192.5(b)(4), where it addresses "buildings with four or more stories above ground are prevalent'? If you have 10 buildings along a pipeline, a downtown area for example, and 5 or less of the buildings are four or more stories, would this be defined as prevalent and constitute being a Class 4 location?" You add, "Are parking garages, open or closed, considered to be buildings intended to be utilized for determination of class location under 192.(b)(3)(ii) and 192.5(b)(4)?"

PHMSA regulations define some terms used in the Federal pipeline safety regulations and accepts commonly used definitions found in reputable dictionaries for undefined terms. Though we do not define "buildings" in 49 CFR Part 192, we believe open or closed parking garages are buildings for class location determinations using any commonly accepted definition of buildings. Also, PHMSA does not define "prevalent" nor do we specify the number (or percent) of buildings with four or more stories that make up a Class 4 location. However, several dictionaries define prevalent as extensively existing, widespread or prevailing.

In the example you use, ten buildings in a downtown area with five or more buildings four stories or more would meet the definition of prevalent (i.e., prevailing). Enterprise must consider public safety and the protection of the environment in deciding whether four or less four story or more buildings means these buildings are prevalent (i.e., extensive or widespread). You must explain your rationale to PHMSA, if questioned.

Lastly you state, "In addition, 49 CFR 192.619(a)(3) allows an operator to establish an MAOP based upon the 5-year window for older systems prior to July 1, 1970. Once that has been established and documented and a class location study is performed resulting in a class location change from what it was on July 1, 1970, does the operator have to incorporate a class location factor for revision of the MAOP established by the 5-year window? Our contention is that the operator does not."

While there is a clause in § 192.619(a)(3) which allows the operator to establish the MAOP as the highest actual operating pressure to which a pipeline segment had been subjected to during the five years preceding July 1, 1970, this is only true if that operating pressure is lower than the design pressure or adjusted test pressure as explained in § 192.619(a). There is a similar provision in § 192.619(c), the "grandfather" clause, which allows an operator to establish the MAOP of a pipeline segment at the highest actual operating pressure to which it had been subjected to during the five years preceding July 1, 1970, as long as the pipeline segment is in good condition and the operator considered the segment's operating and maintenance histories.

Regardless, § 192.609 requires operators to conduct class location studies to look for population density increases along existing steel pipelines operating at a hoop stress above 40% of the specified minimum yield strength (SMYS). If a class location study identifies a pipeline segment with a hoop stress corresponding to an established MAOP that is not commensurate with the present class location, the operator must confirm or revise the MAOP of the pipeline segment using one of the three methods in § 192.611(a). Operators must use all the applicable class location factors wherever called for in each of these methods.

If I can further assist you with this, or any other pipeline safety matter, please contact me at (202) 366-4595.


Florence L. Hamn
Director, Office of Regulations

Regulation Sections

Section Subject
192.5 Class locations