II. SUMMARY OF PRELIMINARY FINDINGS
Following the September 9, 2010 fire and explosion resulting from the rupture of PG&E's pipeline L-132 at San Bruno, California, the Commission ordered PG&E to "review the classification of its natural gas transmission pipelines and determine if those classifications have changed since the initial designation."
(Resolution L-403, adopted September 23, 2010, Ordering Paragraph 18 (Attachment 1).) Further, the Commission ordered PG&E to "report the results of its review of the classification of its natural gas transmission lines and any subsequent changes to those classifications since PG&E's initial designation to the Executive Director within ten (10) days of the date of this Resolution." (Resolution L-403, Ordering Paragraph 19.) On October 4, 2010, PG&E responded to Resolution L-403 stating that it had "completed the review of its gas transmission pipelines operating at pressures greater than 60 pounds per square inch (PSIG) totaling approximately 6,700 miles of pipeline as directed. PG&E's review utilized its gas transmission pipeline database to compare the classification recorded at initial installation to the current classification...[and] identified 1,057 miles of pipeline where the current classification is different from the initial classification." (PG&E's Oct. 4, 2010 Letter to the Commission's Executive Director (Attachment 2).)
On January 3, 2011, the NTSB issued urgent recommendations to PG&E to determine "the valid maximum allowable operating pressure" for its natural gas transmission lines "in class 3 and class 4 locations that have not had a maximum allowable operating pressure established through prior hydrostatic testing" through a "traceable, verifiable, and complete" search of its "as-built drawings, alignment sheets, and specifications, and all design, construction, inspection, testing, maintenance, and other related records." ((P-10-2) (Urgent) and (P-10-3) (Urgent))6 The search required, among other things, that PG&E have in its possession, and readily available, complete and up-to-date records of the class designations of all segments of its transmission pipeline system.
A more thorough search was conducted by PG&E which resulted in the "CPUC Class Location Study" ("Class Location Study") dated June 30, 2011 (Attachment 5). However, PG&E informed the Commission in that Study that PG&E was continuing to review its records to confirm "the appropriate MAOP7 for approximately 100 miles (less than 2%) of the transmission system that, according to information in PG&E's GIS database, may be operating at a higher pressure than appropriate for their current class designation." (Class Location Study at p. 7.) Attachment A to PG&E's Class Location Study provided 54 segments requiring pressure reductions that had no immediate customer impact and Attachment B which contained a list of 13 segments requiring pressure reductions that might impact customers.
Because PG&E has admitted that its class designations are in error for at least some of its transmission pipeline segments, PG&E appears to have failed to comply with federal regulations concerning the protection of persons and property in areas with higher concentrations of human occupancy and activity. Prior to the June 30, 2011 Class Location Study, PG&E does not appear to have reduced the pressure in existing pipeline segments in class 3 and 4 locations as required by 49 C.F.R. § 192.611 or, in the alternative, to replace existing pipeline segments with stronger pipe in these locations as required by that federal regulation.
The Pipeline and Hazardous Materials Administration ("PHMSA") of the U.S.D.O.T. has safety jurisdiction over natural gas transmission pipelines in the United States. (49 U.S.C. § 60101(a)(6)(B).) PHMSA's safety regulations specify minimum safety standards which the states must meet or exceed.8 (See Northwest Gas Ass'n v. Washington Utilities & Transportation Commission, supra.) Among other things PHMSA's pipeline design standards require consideration of the pipeline's proximity to population density. Class location designations are reflective of population density in the immediate vicinity of the pipeline. For example, a class 1 location, defined supra, is the least densely populated location adjacent to the pipeline while a class 4 location is the most densely populated location adjacent to the pipeline segment. Pipeline segments near the more densely populated areas require stronger pipe or reduced gas pressure to mitigate the potential dangers to those populated areas.
6 See the NTSB's five page Safety Recommendation P-10-2 and -3 (Urgent) and P-10-4) to
Mr. Christopher Johns, President, PG&E, dated January 3, 2011, signed by Deborah A.P. Hersman, Chairman, NTSB, (Attachment 3) and the Commission's Executive Director's Letter to PG&E's President, Christopher Johns, dated January 3, 2011, directing PG&E to comply with all of the NTSB's Safety Recommendations (Attachment 4).
7 Maximum Allowable Operating Pressure ("MAOP").
8 49 U.S.C. § 60105(b)(2) provides that a State may be granted safety jurisdiction over its natural gas transmission pipelines so long as the State adopts each safety standard prescribed by the federal government under 49 U.S.C. § 60101 et seq.
