EFI Corporation — Pipeline Safety Interpretation

Page 1PI-01-0116 U.S. Department of Transportation Research and Special Programs Administration 400 Seventh Street, S.W. Washington, D.C. 20590 September 15, 2001 Mr. John Jacobus EFI Corporation 2218 Northpark Drive Kingwood, TX 77339 Dear Mr. Jacobus: Subsequent to our conversation on September 10, 2001, you forwarded an e-mail asking for an interpretation of the exception to the gas transmission line odorization requirements found in the pipeline safety regulations at 49 CFR §192.625(b)(1). This regulation states that a gas transmission line in a Class 3 or Class 4 location must be odorized unless "[a]t least 50 percent of the length of the line downstream from that location is in a Class 1 or Class 2 location." In your example, you note that ten miles of Class 3 or Class 4 transmission line would not have to be odorized if it terminated with as little as one mile of transmission line in a Class 1 or Class 2 location. Your interpretation is correct. If 50 percent of more of the transmission line mileage downstream from a Class 3 or Class 4 location is in a Class I or Class 2 location, the gas need not be odorized. This exception to the odorization requirements was included to address long distance pipelines that pass through some Class 3 or Class 4 locations, but are predominately Class 1 or Class 2 downstream from that location. Although your example is possible, it should be very rare. There are several reasons for this exception. One is that odorization of gas complicates its use as an industrial feed stock. Another is that odorization of transmission lines is of questionable value compared to odorization of distribution pipelines, which operate at a much lower pressure and are more likely to experience slow leaks that could only be detected by odor. If we can be of further assistance in this matter, please contact me at (202) 366-4565. Sincerely yours, Richard D. Huriaux, P.E. Manager, Regulations Office of Pipeline Safety#

Page 2Huriaus, Richard From: John Jacobus [jjacobus@mindspring.com] Sent: Monday, September 10, 2001 11:59 AM To: richard.huriaux@rspa.dot.gov Subject: 196.625 interpretation Thank you for taking the time to talk to me earlier today. My question specifically deals with 49CFR 192.625(b) and sequel. Specifically, (b) states that, “(b) . . .a combustible gas in a transmission line in a class 3 or 4 location must comply with the requirements of paragraph (a) of the section [i.e., must be odorized] unless: (1) At least 50 percent of the length of the line downstream from that location is in a class 1 or 2 location. . . Am I correct in interpreting this section to mean that there is no requirement for odorization of natural gas if a transmission line passes through, for example, 10 miles of class 3 and/or 4 locations and terminates with one mile (or even less) of transmission line passing numerous class 3 and /or 4 locations where long intervening distances are class 1 or 2, but the mere fact that a transmission line terminates in a class 1 or 2 area should not preclude odorization. I would value your comments. Thank you, John jacobus EFI Corporation 2218 Northpark Drive Kingwood, TX 77339#