Williams Brothers Engineering Company — Pipeline Safety Interpretation

Page 1Jul 5 1977 Mr. Leo R. Kenyon Williams Brothers Engineering Company 6600 S. Yale Avenue Tulsa, Oklahoma 74136 Dear Mr. Kenyon: This is in response to your letter of February 25, 1977, in which you requested our definition and advice on three questions concerning Section 192.5 of the Code of Federal Regulations. The following information is furnished in answer to your questions: a. A discussion of the reasons for determining 10 or less buildings for Class 1 location and 46 or less buildings for Class 2 location are contained in Notice 70-4, Docket No. OPS- 3D (enclosed). The study which formed the basis for these determinations is also enclosed. b. "Normal use" is interpreted to mean the activity that is ordinarily engaged in on the premises. The frequency of normal use is a factor to consider in determining whether the use of a building or outside area creates a risk which is similar enough to the risk to the areas mentioned in §192.5(d)(2)(ii) to warrant application of Class 3 standards. c Intended for "human occupancy" is interpreted to mean that the building concerned is used for a purpose involving the presence of humans. Enclosed are copies of the Office of Pipeline Safety Operations' Advisory Bulletin, Nos. 71-4, 73- 11, 75-4, and 76-11, which contain interpretations of specific examples which may be of assistance. If we can be of further assistance, please let me know. Sincerely, Cesar DeLeon Acting Director Office of Pipeline Safety Operations dal\192.1-a\5\77-07-05 1#

Page 2February 25, 1977 Department of Transportation Office of Pipeline Safety Operations 400 Seventh Street, S.W. Washington, D.C. 20024 ATTENTION: Director Dear Gentlemen: We have been requested by our client in Australia to seek your definition and advice on the following which pertain to DOT regulations 192.5, class locations: a. Basis for the number of buildings for class 1 and class 2 locations. How were the numbers 10 or less buildings for class 1 and 46 or less buildings for class 2 locations arrived at? b. What is the interpretation of "normal use" as used in defining class locations? What frequency of use of a building or defined outside area by more than 20 people would require the location to be classified 3; once a day, week, month, year? c. What is the interpretation of "Intended for Human Occupancy" as used in 192.5? Our Australia client is assisting with revisions to the Australia Pipeline Code and wishes to use the interpretation and advice of your office on the above questions. We would be grateful of any assistance you could provide. Very truly yours, WILLIAMS BROTHERS ENGINEERING COMPANY Leo R. Kenyon dal\192.1-a\5\77-07-05 2#