Northern Natural Gas Company — Pipeline Safety Interpretation

Page 1February 10, 1983 Ms. Evangeline Levison Attorney Northern Natural Gas Company 2223 Dodge Street Omaha, Nebraska 68102 Dear Ms. Levison: Your letter of February 1, 1983, regarding your telephone conversation with Mr. Robert Langley on January 5, 1983, appears to adequately cover Mr. Langley's remarks to you. As you mentioned, Northern Natural Gas must still comply with Subpart L, Operations, and Subpart M, Maintenance, of 49 CFR Part 192. The requirement of §192.703(b) has the greatest significance for the particular situation described. As was discussed, paragraph (b) states: Each segment of pipeline that becomes unsafe must be replaced, repaired, or removed from service. The determination of whether or not a particular segment of pipeline is unsafe and whether or not it is in compliance with Part 192 is made by the materials Transportation Bureau's Office of Operations and Enforcement (OOE) through a field office or a State agency. For this reason, a copy of this letter is being forwarded to the OOE Central Region Office in Kansas City, Missouri. We trust this helps to further clarify our answer in this matter. Sincerely, Richard L. Beam Associate Director for Pipeline Safety Regulation Materials Transportation Bureau dal\192\703\83-02-10 1#

Page 2February 1, 1983 Mr. Robert Langley Office of Pipeline Safety Department of Transportation Washington, D.C. 20590 Dear Mr. Langley: This letter is in confirmation of our January 5, 1983 telephone conversation regarding the necessity for Northern Natural Gas Company, Division of InterNorth, Inc., to lower a pipeline in a creek which becomes partially exposed during periods of low rainfall. When the pipeline was originally installed by Northern Natural Gas Company, although the path of the creek crossed the pipeline, the pipe was buried sufficiently deep as to not be exposed. Subsequent to that time the owner of the farm on which the pipeline was installed decided to straighten the path of the creek. As a result, the pipeline is partially exposed at the point where the creek now crosses it when the water level in the creek is at a low. Title 49, Code of Federal Regulations, §192.327(a) requires transmission lines in Class 1 locations be buried with 30 inches of cover. This section does not apply to pipeline installed prior to March 12, 1971 unless the pipeline has been replaced, relocated or otherwise changed since 1970. 49 CFR 192.13(b). This pipeline was installed prior to March 12, 1971, and my question to you was whether the straightening of the creek constituted a pipeline relocation under 192.13(b), thus making the pipeline subject to the 192.327(a) requirement of 30 inches of cover. We have reviewed the situation and are in agreement with your opinion that the relocation of the creek does not constitute a relocation of the pipeline. Thus, this pipeline is exempt from the 49 CFR §192.327(a) cover requirements. However, we are aware that Northern Natural Gas must still comply with Subpart L, Operations, and Subpart M, Maintenance. Thank you for your assistance in this matter. Very truly yours, dal\192\703\83-02-10 2#

Page 3Evangeline Levison Attorney dal\192\703\83-02-10 3#