II. SUMMARY OF EXPLOSION

On December, 24, 2008, a gas explosion and ensuing fire occurred in a residential neighborhood of Rancho Cordova, California.  The explosion and fire destroyed one home (10708 Paiute Way) and severely damaged two other homes (10712 and 10704 Paiute Way).  One home dweller, then at home at 10708 Paiute Way, was injured critically and died shortly thereafter at a Sacramento area hospital.  Five other persons, including neighborhood dwellers and PG&E personnel present at the incident site, were injured, some critically, by the blast and fire.  Some were hospitalized and treated for severe burns or other injuries, but all five persons survived their injuries. 

The National Transportation and Safety Board ("NTSB"), along with CPSD investigated the gas explosion and fire. Since it is not the Commission's intent to
pre-judge the facts involving this explosion or about PG&E, we expect PG&E to provide us with identification of any factual assertions or conclusions stated in the NTSB's "Pipeline Accident Brief" ("PAB"), adopted by the NTSB on May 18, 2010, and in CPSD's report, which PG&E contends are erroneous or which PG&E wishes to qualify or explain. We have also chosen at this time not to repeat any additional facts asserted by CPSD in its own report. The Commission has reached no finding or conclusion about the facts asserted by any party, but concludes that the information set forth by the NTSB and CPSD reports are sufficient for this Commission to commence a formal investigation.

According to the NTSB PAB, the following events occurred:

A. Rancho Cordova Gas Service and PG&E's 2006 Gas Repairs

In 1977, PG&E installed a 2-inch in diameter polyethylene (PE) gas pipeline to serve the homes on Paiute Way in Rancho Cordova. (NTSB Pipeline and Operations Factual Report by Karl Gunther, released on December 3, 2009, p. 6) The pipeline is buried under the lawns of several homes on Paiute Way.

On September 15, 2006, about 7 A.M., a resident at 10708 Paiute Way complained about gas odor (PAB, p.9). PG&E dispatched a crew to the address at about 4 P.M. on that day. PG&E found the odor source to be a leak in the 2-inch PG&E PE pipe buried in the front lawn of the home.  

PG&E completed its repair of the gas leak on September 21, 2006.  PG&E's repair consisted of about 20 feet of 1¼-inch diameter PE pipe that was inserted into the existing 2-inch diameter leaking main gas pipe. PG&E's gas service technician also installed a pipe of about six inches in length, between the repair coupling and the reducer fitting to connect the 2-inch pipe with the repair coupling that was installed in connection with the 1¼ -inch pipe (PAB, p.7). According to NTSB, this small piece of pipe was unmarked and out of specification, and was the probable cause of the gas leak and explosion in Rancho Cordova on December 24, 2008 (PAB, pp. 9 and 10). 

After the December 24, 2008 explosion, CPSD and PG&E investigated PG&E records and determined that prior to the explosion; PG&E had installed another non-conforming gas pipe. This occurred on October 7, 2006, in Sacramento, when a newly installed PG&E pipe repair failed its installation leak test. The repair pipe used was removed and tested. Testing found that the pipe failed to meet its required wall thickness, causing the leak. PG&E felt that the pipe failure "was an isolated incident" and conducted no "further reviews within PG&E" (PAB, p. 10).

B. Summary of the events of December 24, 2010

On December 24, 2008, at 9:16 AM, a resident at 10716 Paiute Way telephoned PG&E and notified the company about a gas odor outside her house.  PG&E dispatched a technician to the site. She arrived at about 10:15 A.M. (PAB, p. 1 and 2), with equipment and training which NTSB concludes was insufficient to grade outdoor gas leaks (PAB, p. 2).

The technician began her tests and examinations to locate the gas leak.   She conducted gas finding tests and procedures at 10716 Paiute Way with the equipment that was available at her disposal, and detected the presence of gas in the water box located outside and in front of the house (PAB, p. 2).

The PG&E technician left the premises at 10716 Paiute Way, and at 10:24 A.M. spoke to the neighbor at 10712 Paiute Way, who told the technician that she had smelled gas outside her house.  At 10:25 A.M., the technician telephoned PG&E's dispatch on a dedicated line to request an ionization detector ("flame pack") and a crew to help locate an outdoor leak. The technician also asked the resident of 10712 Paiute Way to call PG&E and report a leak in her yard. The resident did so at 10:29 A.M., and reported to PG&E "a strong gas odor outside her house in the garage area" (PAB, p.3). At about 10:42 A.M., a PG&E maintenance supervisor dispatched to the site a fieldman, a foreman, and a leak investigator qualified by PG&E to use the flame pack (PAB, p. 3). 

The PG&E technician recognized "the immediate need for assistance from an ionization crew," and called PG&E's Concord Dispatch directly about 10:32 A.M. to request a crew. She made a second call at about 10:35 A.M. to PG&E's Customer Contact Center (PAB, p. 3).

Another resident at 10712 Paiute Way talked with the technician and told her that the "source of the leak was in his next-door neighbor's yard," (PAB, p.3). The address of the neighbor was 10708 Paiute Way.  

The technician then went to the home at 10708 Paiute Way, and performed a "clock test" on the meter there which showed almost no flow (this may indicate less likelihood of a gas leak originating on the inside of the house). She knocked on the door to gain access and check for gas inside but no one answered.   The technician noted a patch of dead grass on the front lawn (we understand that gas leaks can kill grass by depriving it of air). The technician then used the equipment she had to detect the presence of gas in the yard (PAB, p.4). 

During the time that she was at the site, the technician reportedly called multiple times to request PG&E to send the proper equipment and personnel to locate the leak (PAB, pp. 3 and 4). The technician later told investigators that "she had become increasingly concerned about the leak at the time (PAB, p. 4). The technician "did not contact the fire department to request entry into the house, nor did she place signs on the doors or string up tape to warn residents that entry could be hazardous" (PAB, p.4).

According to statements made to NTSB investigators, persons entered 10708 Paiute Way at about noon, while the PG&E technician was sitting in her vehicle.  They were the home owner, his 44-year old daughter, and 17-year old granddaughter (PAB, pp.4 and 6).

The leak investigator arrived at the site at 1:19 P.M., about two hours and forty seven minutes after the technician requested that PG&E send a flame pack and its operator (leak investigator) to the site. The leak investigator later told investigators that brake problems on his truck delayed him coming to the site. The leak investigator did not notify PG&E dispatch of his delay (PAB. p. 4 and 5).

When the leak investigator arrived at the site, he knocked at the door of 10708 Paiute Way.  The door was opened by the 17 year old granddaughter of the
homeowner. The homeowner and the PG&E leak investigator then went outside (PAB, p.5).

At about 1:35 P.M., the home at 10708 Paiute Way exploded (PAB, p.5).

C. Summary of Damage to Persons and Property

The natural gas explosion and fire destroyed the home at 10708 Paiute Way, and severely damaged two other homes. The homeowner at 10708 Paiute Way died and five other persons were hospitalized (PAB, p.1).

The NTSB May 10, 2010 PAB does not identify the ignition source of the explosion. CPSD has identified the likely source of the explosion to be the flick of a cigarette lighter by the 17 year old homeowner's granddaughter in the bathroom at 10708 Paiute Way.

D. Investigations to date

Several agencies have conducted investigations of the explosion.  The Sacramento Police Department and the Rancho Cordova Police Department jointly conducted an investigation and issued a report.  The report is relevant to the Commission's investigation, because among other things it contains witness statements about the gas leak and their asserted reports to PG&E.  The report also identifies alleged resident requests to PG&E before the explosion to evacuate the area.  The report is dated December 24, 2008 (the day of the explosion), with supplementary information dated December 29 and 30, 2008, various dates in January 2009, and February 3, 2009. 

The NTSB is a federal government agency. Among other responsibilities, NTSB is charged with a responsibility to investigate and determine the causes of gas explosions, such as the one that occurred at Rancho Cordova.  NTSB conducted an investigation consisting of (1) recorded interviews of witnesses to the explosion or to events which may have led to the explosion, and to the ensuing fire and rescue efforts (neighborhood residents, PG&E personnel, firemen, and police), and (2) scientific laboratory testing of the PG&E gas pipes and facilities that failed and may have contributed to causing the leak and explosion. CPSD investigators participated actively in the NTSB investigation.

NTSB's May 18, 2010, PAB determined that "the probable cause of the December 24, 2008, release, ignition, and explosion of natural gas in Rancho Cordova, California, was the use of a section of unmarked and out-of-specification PE pipe with inadequate wall thickness that allowed gas to leak from the mechanical coupling installed on September 21, 2006. Contributing to the accident was the 2-hour 47-minute delay in the arrival at the job site of a Pacific Gas and Electric Company crew that was properly trained and equipped to identify and classify outdoor leaks and to begin response activities to ensure the safety of the residents and public" (PAB, p. 16).

NTSB's PAB also states that the explosion "illustrates shortcomings in PG&E's response procedures." First, NTSB notes that prior to the explosion, PG&E employees dispatched and responding to a gas leak did not "require any of the responders to periodically check in with their dispatch offices to communicate delays in responding." Second, the NTSB notes that PG&E dispatched first responding technicians to leaks complaints that "were neither trained in grading outdoor leaks nor equipped with the equipment required to do so under PG&E's operator qualification program"(PAB, p.14). The NTSB also finds that PG&E technicians "did not have barrier tape or notices that could be used to warn an absent homeowner that the house was dangerous because of leaking gas and not to enter the house." (Id. at 14).

CPSD also conducted its own investigation of the explosion to determine whether PG&E violated any applicable statutes, Commission decisions, Commission general orders, or any other Commission and state regulation or standards, and whether any such violations caused or contributed to the explosion and the injuries and damage that it caused.   CPSD investigators participated actively in the NTSB interviews.  CPSD also conducted other discovery, such as an on-site visit to the incident site on the day of the explosion, data requests, and a field visit to PG&E's Sacramento Division yard. The CPSD report contends that PG&E violated California statutes, Commission general orders requiring safe utility operation, and federal gas safety requirements that the Commission and its staff are by law authorized to enforce.  CPSD also contends that PG&E practices and policies were deficient and contributed to the December 24, 2008 Rancho Cordova explosion. CPSD contends that PG&E practices were deficient with respect to ensuring the installation and maintenance of appropriate gas pipe for the timely detection of and proper attention to dangerous gas leaks, the development and implementation of effective evacuation procedures, and the training and supervision of PG&E gas personnel in each of these areas, and with respect to other matters.

The Commission has reached no conclusion or made no finding from any source that PG&E has violated any statutory responsibilities, general orders, decisions, or other legal requirements or standards.  However, the NTSB's PAB and CPSD's report have presented us with sufficient information and good cause to commence a formal investigation to ascertain whether such violations have occurred, and if so, the proper remedy for such violations. 

  This agency is charged with a responsibility to identify, address, and correct any safety deficiencies in PG&E's system and management that are proven in this investigation, and that PG&E may not have already rectified fully. The Commission is aware that PG&E has made efforts to undertake "a number of process improvement initiatives to improve response time and efficiency and to preclude the introduction of nonspecification pipe for repairs" (PAB, p.15). The PAB provides a list of PG&E's efforts. The Commission expects to review them in this proceeding and ascertain whether they are adequate.