In separate actions last Thursday to provide utility bill discounts for victims of the San Bruno, CA, gas pipeline explosion and prepare for winter natural gas delivery operations in the event of a severe cold snap, the head of the California Public Utilities Commission (CPUC) said regulators would make sure the pipeline is rerouted.

“The ruptured segment of the transmission pipeline [Line 132] will remain out of service indefinitely,” said CPUC President Michael Peevey. He urged his colleagues to give him emergency power to raise the pressure on existing pipelines this winter if needed to avoid curtailments. “Under no circumstances should this commission allow PG&E [Pacific Gas and Electric Co.] to rebuild that pipeline through the neighborhood in San Bruno where this terrible tragedy occurred,” Peevey said.

“And I think that [the utility executives] after some back-and-forth have made that clear publicly. They will have to find a different route for the pipeline, and I want to be clear on that point.”

In response to an inquiry from the mayor of San Bruno, PG&E committed last week to reroute the repaired 30-inch diameter transmission pipeline that failed Sept. 9 killing eight people, destroying 37 homes and badly damaging 18 other homes (Separately last Thursday during a broad-ranging interview with NGI, PG&E’s Kirk Johnson, vice president for gas engineering and operations, said the utility has no intention to try to rebuild the 1.5-mile part of Line 132 in the heart of the devastated area. He said they are weighing a number of alternative routes).

Peevey and three of his colleagues on the five-member commission (Commissioner Dian Grueneich was absent) separately approved resolutions to grant Peevey authority to order the pipeline pressure raised in the peninsula region south of San Francisco this winter when the health and safety of the public would be threatened by curtailments of large institutional and industrial operations, including hospitals and public safety operations, and authorized PG&E to provide shareholder-supported rate relief for 374 customers directly impacted by the pipeline failure.

The action gives the CPUC head “backstop authority,” which he said he hopes not to ever use. This is an offshoot of PG&E’s submittal of a contingency plan to the CPUC for dealing with the operation of the transmission lines at lower-than-normal pressure.

“My expectation is that PG&E will be able to meet its obligations this winter without any increase in pressure,” Peevey said. “What we’re talking about here at most is a slight increase in pressure in Line 132. We would not allow a move back to full 100% of its historical pressure levels. And we would have to be absolutely convinced that even a slight increase in pressure is absolutely necessary to meet gas demands by the public in San Francisco and on the peninsula.”

San Bruno residents and the local state Assembly representative Jerry Hill appeared before the CPUC urging regulators not to allow the utility to change the pipeline pressures, which were lowered by 20% in the wake of the pipeline failure. But the lower pressures come with the risks to the overall transmission pipeline backbone system’s reliability this winter in the peninsula and San Francisco areas in particular, and the CPUC wanted to be able to avoid critical gas service curtailments to hospitals and others.

The so-called noncore customers are viewed as being at greater risk than usual this winter. “According to the data I have, virtually every hospital in San Francisco and on the peninsula would be at risk of shutoff of their gas service this winter,” said Peevey.

“In two or three months we could very well face that [extreme] situation, but it is unlikely,” Peevey said. “It is our responsibility at the CPUC to take appropriate steps to protect the public safety as it relates to the reliability of natural gas service in the cold winter months. Safety comes first, and in no circumstance can we allow PG&E to operate its gas system in any manner that is unsafe.

Earlier in the last week of October, a San Francisco-based PG&E spokesperson told NGI that the combination utility was offering to cover all the applicable expenses not covered by the individual homeowner’s insurance, depending on which option (sell or rebuild homes) is selected. In addition, PG&E is offering to provide cash bonuses for various options, exercised over given time periods. There are rebuild, sale and beautification options for the 55 destroyed or badly damaged properties, along with homes in the general broad impact area.

Following a six-hour state legislative joint hearing Oct. 19, it appeared there will be increased expectations, if not new legislative mandates, for the California Public Utilities Commission to step up its oversight of the state’s many thousands of miles of high-pressure, large-diameter transmission pipelines traversing heavily populated areas, such as San Bruno.

The idea of stepped up state oversight is spreading to states outside of California as demonstrated by the Arizona Corporate Commission’s (ACC) winter preparedness meeting for all gas distribution utilities and interstate pipeline operators in the state. The main topic of interest among the five ACC members was the San Bruno pipeline incident and how Arizona guards against something similar happening there.

Limited curtailments this winter, up to 300 new shutoff valves, and new leaks identified and repaired on parts of the major natural gas transmission pipeline system in the greater San Francisco Bay Area were documented in reports released late last Monday by PG&E and the CPUC. A survey of 16 miles of gas transmission pipes in the San Bruno area turned up no problems needing immediate repair, the combination utility told the CPUC in its report, which covers actions directed by state regulators in a resolution passed Sept. 23.

Looking at 15.93 miles of transmission piping in San Bruno where a sector of the utility’s 30-inch diameter Line 132 failed, PG&E indicated that it used three instruments to survey the transmission mains in the suburb: close interval survey (CIS), direct current (DC) voltage gradient, and pipeline current mapper (PCM) tools. The survey included Lines 101 and 109, in addition to Line 132.

The other areas covered in the 23 pages of text and maps were the automatic shutoff valves, an accelerated survey of the entire PG&E backbone gas transmission system, and the contingency plans for curtailment of some industrial customers if lower operating pressure levels are continued into the winter season. Curtailment estimates are preliminary and will not be finalized until there is a final determination on the allowable operating pipeline pressures, the utility said.

Estimates used three different daily average temperatures (42, 37 and 32 degrees F) and assumed a new plan for beefing up pipeline capacity in the three peninsula lines (101,109 and 132). At a 300 pounds-per-square-inch-gauge (psig), PG&E said it could not meet either a cold winter day (CWD) or abnormal peak day (APD).

“On an APD, 100% of all San Francisco and peninsula noncore customers will need to be curtailed, along with some large core customers,” the utility told the CPUC. It further noted that the extent of the curtailments can be reduced if Line 101 and/or Line 109 are operated above 300 psig. “To avoid core customer curtailment, L101 and L109 must both operate at pressures above 300 psig, or L101 must operate at a pressure near 375 psig. “PG&E will develop a final curtailment plan when operating pressures are finalized and system capacity for the winter is known.”

Under its new Pipeline 2020 long-term revision of transmission safety and maintenance programs, PG&E assessed the need for automatic or remote shutoff valves to replace the numerous manual ones on its transmission pipelines. The preliminary analysis identifies at least 300 potential locations for the added equipment. These findings will be reviewed by the CPUC staff and a third-party natural gas expert that the utility will retain.

As part of the overall Pipeline 2020 program, PG&E also has hired another third-party firm to review and refine its preliminary analysis.

PG&E Vice President Johnson said the utility has been “working intensely” to reexamine its transmission system and pipeline operational practices. “[This] filing shows how much progress we have made in a short period of time, but it also points to significant work still ahead of us.”

©Copyright 2010Intelligence Press Inc. All rights reserved. The preceding news reportmay not be republished or redistributed, in whole or in part, in anyform, without prior written consent of Intelligence Press, Inc.