NTSB Safety Recommendation P-82-003

NTSB safety recommendation P-82-003.

AS A RESULT OF ITS INVESTIGATION OF THIS ACCIDENT, THE NTSB RECOMMENDS THAT THE PACIFIC GAS AND ELECTRIC COMPANY: INCLUDE IN ITS WRITTEN MAINTENANCE PROCEDURES A REQUIREMENT THAT EMERGENCY VALVES BE OPERATED DURING ANNUAL INSPECTIONS AND EMPHASIZE THIS REQUIREMENT TO MAINTENANCE PERSONNEL.

Priority: CLASS II

Overall Status: Closed - Acceptable Action

Issued Date: 1982-04-16

Adopted Date: 1982-02-25

Overall Date Closed: 1982-08-31

Synopsis: ON AUGUST 25, 1981, IN DOWNTOWN SAN FRANCISCO, CALIFORNIA, A 16-INCH NATURAL GAS MAIN OWNED BY THE PACIFIC GAS AND ELECTRIC COMPANY (PG & E) WAS PUNCTURED BY A DRILL THAT AN EXCAVATION CONTRACTOR WAS USING TO SET TIEBACKS FOR ANCHORING HIS EXCAVATION SHORING. ESCAPING NATURAL GAS BLEW UPWARD AND CARRIED INTO THE EMBARCADERO COMPLEX AND OTHER NEARBY BUILDINGS. THERE WAS NO IGNITION; HOWEVER, THE GAS STREAM ENTRAINED AN OIL CONTAINING POLYCHLORINATED BIPHENYL (PCB). FALL-OUT AFFECTED AN EIGHT-SQUARE-BLOCK AREA OF THE CITY'S FINANCIAL DISTRICT COVERING BUILDINGS, CARS, TREES, PEDESTRIANS, POLICE, AND FIREMEN. APPROXIMATELY 30,000 PERSONS WERE SAFELY EVACUATED FROM THE AREA IN 45 MINUTES. NO ONE WAS KILLED OR SERIOUSLY INJURED, ALTHOUGH MANY PERSONS WERE SPRAYED WITH THE PCB OIL MIST.

Probable Cause: None

Ntsbnumber: DCA81MP020

Report Number: PAR-82-01

Addressee Name: Pacific Gas and Electric Company

Addressee Status: Closed - Acceptable Action

Addressee Date Closed: 1982-08-31

Addressee Acronym: PG&E

Addressee Organization Type: P-Private Industry

Communication Date: 1982-08-31

Communication Type: Official Correspondence

Communication Contents: We have reviewed your June 21, 1982, response to the National Transportation Safety Board's Safety Recommendations P-82-1, -2, and -3 which were issued as a result of our investigation of the natural gas leak at a construction site in San Francisco, California on August 25, 1981. The Board is pleased that, as a result of problems identified during this accident, emergency response training has been intensified at your company with special attention being given to locating and operating emergency shutdown valves. Based on this information, we have placed P-82-l in a "Closed-Acceptable Action" status. We would appreciate receiving an outline of the training program described. The effort to update and verify emergency shutdown diagrams and to inspect such valves twice annually is acceptable in fulfilling the intent of P-82-2. We have placed this recommendation in a "Closed-Acceptable Action" status. Your new standard on servicing and lubrication of valves along with the two letters to division gas superintendents dated September 3, 1981, and November 20, 1981, are·acceptable in fulfilling the intent of P-82-3. This safety recommendation has been classified as "Closed-Acceptable Action." We would appreciate receiving a copy of the new standards as well as copies of the two letters mentioned. Your comments concerning the rapidity of system shutdown during the accident have been placed in the docket for this accident and will be considered a part of the public record. We appreciate the time and effort you have spent in reviewing and acting upon our recommendations.

Addressee Acronym: PG&E

Addressee Organization Type: P-Private Industry

Communication Date: 1983-01-19

Communication Type: Official Correspondence

Communication Contents: Thank you for your October 5, 1982, letter providing further information we requested in our August 31, 1982, letter concerning the National Transportation Safety Board's Safety Recommendations P-82-1, -2, and -3 which stemmed from the pipeline accident in San Francisco on August 25, 1981. We appreciate the additional information provided as requested in our August 31, 1982, letter. Your cooperation in implementing our recommendations is appreciated.

Addressee Acronym: PG&E

Addressee Organization Type: P-Private Industry

Communication Date: 1982-06-21

Communication Type: Official Correspondence

Communication Contents: -From Howard M. McKinley, Vice President, Gas Operations: A letter was issued on September 3, 1981, to all division gas superintendents to initiate a procedure to make a positive determination that valves installed to isolate emergency shutdown zones are in good working order. A follow-up letter dated November 20, 1981, specified that the valves are to be closed up to fifty percent, depending on the load conditions. The gas standard covering the servicing and lubrication of valves required that a valve, after lubrication, should be operated until it turns freely. This standard is being revised to require that a valve be operated up to fifty percent if load conditions permit. The revised standard will be issued by mid-July of 1982. PG and E concurs that it is prudent to have as many crews as practical trained and equipped to respond to an emergency. Steps have already been taken to accomplish this, as outlined in our response to Recommendation P-82-1. However, PG and E wishes to clarify a point concerning statements in the report that the shutdown might have been accomplished more rapidly if the company personnel first arriving at the site had been trained or equipped to close valves. The company employee first on the site was the foreman of a two-man leak repair crew working in the vicinity at the time of the incident. He was not dispatched to the site of the incident, but responded on his own initiative after hearing the noise of escaping gas. A crew of this type would normally not be called upon to respond to a major gas leak such as the August 25, 1981 incident, and would not normally be equipped to do so. Even if equipped with the proper tools, this crew would not initiate closing of valves on a major feed such as the line involved in the incident, without being directed to do so by Emergency Operating Room personnel. Such action could create more serious problems than the one which already existed. The first employees dispatched in response to the emergency arrived at the site at 1:45 pm, only twelve minutes after the accident. Initial efforts were directed to determining the extent of the gas leakage into buildings and assisting in the evacuation. The first crew dispatched to close a valve (Valve 141) arrived at the site at 2:02 pm, and the last of the five valves listed for this emergency shutdown was closed at 2:28 pm. Had the diagram been correct, the shutdown would have been accomplished in under one hour. PG and E concurs with the attention directed toward one-call systems, and to the effort to encourage excavators and those who control them to utilize these programs. This recognizes that while the utility operators have an obligation to provide information to excavators, a damage prevention program cannot succeed without the cooperation of those who are actually doing excavations. PG and E believes that with the exception of the one clarification, the NTSB Report PAR-82-1 represents a fair and accurate evaluation of the incident.

Addressee Acronym: PG&E

Addressee Organization Type: P-Private Industry

Communication Date: 1982-10-05

Communication Type: Official Correspondence

Communication Contents: -From Howard M. McKinley, Vice President, Gas Operations: This letter is in response to your August 31, 1982 letter concerning the National Transportation Safety Board recommendations P-82-1, 2, and .3. we are pleased that the action taken by Pacific Gas and Electric Company (PG and E) subsequent to the August 25, 1981 incident was satisfactory, and that these three recommendations now have a Closed-Acceptable Action status. In conjunction with your comments on the additional training recommended in P-82-1, you requested an outline of the training program described in our June 21, 1982 letter. We have attached a copy of the Employee Training Program section of the PGandE Gas Department Emergency Plan. This is the outline which must be followed by each of the thirteen operating divisions when developing an emergency training program to meet the requirements of its specific area. As indicated in our June 21, 1982 letter, this normal training program had been intensified from September 1981 to June 1982. Specifically, this program provided for over one thousand man-hours of additional time spent on emergency shutdown training and exercises, and was directed toward local gas operating supervisors, engineers, and mechanics. These people were required to review and study all the emergency shutdown references pertaining to their systems and to inspect each valve. Supervisors from our General Office visited the division and district offices providing direction where required and, by conducting performance tests, verified that the training objectives were being attained. The objectives included a thirty-minute limit for formulating an effective shutdown plan for a randomly chosen section of pipeline or main, and then a faultless execution of the plan. Visits were repeated as required for assurance of competency. Copies of the September 3, 1981 and November 20, 1981 letters to the division gas superintendents concerning emergency shutdown valves and a copy of Gas Standard F-11, Valve Lubrication and Maintenance Requirements, are also enclosed, as requested in your letter. With respect to other recommendations made in NTSB-PAR-82-1, California has recently passed legislation (Assembly Bill No. 3019) signed into law on September 29, 1982, which requires that every owner of a subsurface installation, except the Department of Transportation, must become a member of and participate in a regional notification center. It further states that no excavation permit issued by any local agency shall be valid unless it has an identification number indicating that the regional notification center has been notified of the proposed excavation work. I am confident that positive actions taken by PG and E since the August 25, 1981 incident and the recently passed legislation on notification centers and permits reduce the chances of future similar dig-ins.