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PB97-916501NTSB/PAR-97/0l

NATIONALTRANSPORTATIONSAFETYBOARD

WASHINGTON, D.C. 20594

PIPELINE ACCIDENT REPORT

SAN JUAN GAS COMPANY, INC./ENRON CORP.PROPANE GAS EXPLOSION IN SAN JUAN, PUERTORICO, ON NOVEMBER 21, 1996

6789C

Abstract: About 8:30 a.m. on November 21, 1996, because of a propane gas leak, acommercial building in San Juan, Puerto Rico, exploded. Thirty-three people were killed, and atleast 69 were injured.

The safety issues discussed in this report are the adequacy of employee training, the needfor an excavation-damage prevention program, the adequacy of maps and records of buriedfacilities, the adequacy of public education on what to do when the odor of gas is detected, andthe adequacy of the oversight of the San Juan Gas Company, Inc., from Enron Corp., the PuertoRico Public Service Commission, and the Office of Pipeline Safety.

As a result of its investigation, the National Transportation Safety Board issuedrecommendations to the Secretary of the U.S. Department of Transportation, the Research andSpecial Services Administration, the Puerto Rico Public Service Commission, Enron Corp., andHeath Consultants, Inc.

The National Transportation Safety Board is an independent Federal agency dedicated topromoting aviation, railroad, highway, marine, pipeline, and hazardous materials safety. Establishedin 1967, the agency is mandated by Congress through the Independent Safety Board Act of 1974 toinvestigate transportation accidents, determine the probable causes of the accidents, issue safetyrecommendations, study transportation safety issues, and evaluate the safety effectiveness ofgovernment agencies involved in transportation. The Safety Board makes public its actions anddecisions through accident reports, safety studies, special investigation reports, safetyrecommendations, and statistical reviews.

Information about available publications may be obtained by contacting:

National Transportation Safety BoardPublic Inquiries Section, RE-51490 L’Enfant Plaza, S.W.Washington, D.C. 20594(202) 314-6551

Safety Board publications may be purchased, by individual copy or by subscription, from:

National Technical Information Service5285 Port Royal RoadSpringfield, Virginia 22161(703) 605-6000

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PIPELINE ACCIDENT REPORT

Adopted: December 23, 1997Notation 6789C

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CONTENTS

EXECUTIVE SUMMARY...........................................................................................................vii

INVESTIGATION .......................................................................................................................... 1The Accident ................................................................................................................................... 1

Week Preceding Accident ........................................................................................................1Thursday, November 14........................................................................................................... 3Friday, November 15................................................................................................................ 3Monday, November 18............................................................................................................. 5Wednesday, November 20 ....................................................................................................... 5Thursday, November 21........................................................................................................... 7

Injuries............................................................................................................................................. 9Emergency Response....................................................................................................................... 9Survival Aspects............................................................................................................................ 11Damage.......................................................................................................................................... 11Personnel Information ................................................................................................................... 12

Dispatcher. ............................................................................................................................. 12Technician.............................................................................................................................. 12First Brigade Leader............................................................................................................... 12Second Brigade Leader ..........................................................................................................12Third Brigade Leader ............................................................................................................. 12MCC....................................................................................................................................... 13Assistant Operations Superintendent ..................................................................................... 13Operations Superintendent..................................................................................................... 13Safety Manager ...................................................................................................................... 13General Manager.................................................................................................................... 14Fatigue.................................................................................................................................... 14

Training ......................................................................................................................................... 14SJGC Training........................................................................................................................ 14Leak Survey Training............................................................................................................. 15

Gas Company Operations.............................................................................................................. 16Gas Distribution and Ownership............................................................................................ 16Pipes and Ducts Installed on Camelia Soto............................................................................ 16Public Education .................................................................................................................... 17Emergency Procedures...........................................................................................................18Leak Surveys .......................................................................................................................... 19Odorization............................................................................................................................. 19Excavation-Damage Prevention Program.............................................................................. 20Gas Maps and Records...........................................................................................................20Corrosion Protection. ............................................................................................................. 21Plastic Pipe............................................................................................................................. 21Abandoned Services............................................................................................................... 22

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Unaccounted for Gas.............................................................................................................. 22Meteorological Information .......................................................................................................... 22Medical and Pathological Information .......................................................................................... 22Tests and Research ........................................................................................................................ 23

SJGC Pipelines....................................................................................................................... 23Sbarro Restaurant Propane Fuel Lines................................................................................... 25Smoke Migration Tests ..........................................................................................................25Examination of Debris and Retrieved Damaged Materials.................................................... 27Laboratory Examination of Failed Pipes................................................................................ 28

Oversight and Regulation.............................................................................................................. 29Enron...................................................................................................................................... 29PSC ........................................................................................................................................ 32

PSC Inspections of SJGC ............................................................................................... 32PSC Annual Program Certification................................................................................. 34

OPS ........................................................................................................................................ 35Other Information.......................................................................................................................... 36

Humberto Vidal...................................................................................................................... 36Emergency-Response Procedures ................................................................................... 36HV Building....................................................................................................................36

Excavation-Damage Prevention............................................................................................. 36

ANALYSIS ................................................................................................................................... 38Exclusions ..................................................................................................................................... 38The Accident ................................................................................................................................. 39

Propane Release Points .......................................................................................................... 39Migration Paths into HV Basement. ...................................................................................... 39Fueling the Explosion. ........................................................................................................... 39Location of Explosion in HV Building. ................................................................................. 40

Gas Leak Investigation Procedures ............................................................................................... 40Excavation-Damage Prevention.................................................................................................... 40Emergency Response..................................................................................................................... 44Survival Aspects............................................................................................................................ 44Public Education ........................................................................................................................... 46Employee Training ........................................................................................................................ 49

Assessing Effectiveness of Training on Barhole Depth......................................................... 50Federal Employee Training Requirements............................................................................. 52

Pipeline Safety Oversight .............................................................................................................. 53Enron...................................................................................................................................... 54PSC ........................................................................................................................................ 54OPS Oversight of State Pipeline Safety Program .................................................................. 56

CONCLUSIONS........................................................................................................................... 58Findings......................................................................................................................................... 58Probable Cause.............................................................................................................................. 59

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RECOMMENDATIONS .............................................................................................................. 60

APPENDIX A: Investigation and Hearing.................................................................................... 63

APPENDIX B: Summary of PSC Compliance Inspections of SJGC ........................................... 65

APPENDIX C:�Summary of OPS Oversight Actions Relative to PSC ........................................ 69

APPENDIX D: Employee Training and Qualifications................................................................ 77

APPENDIX E: Sketch of Basement Showing Direction of Forces on Columns.......................... 79

ABBREVIATIONS....................................................................................................................... 83

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About 8:30 a.m. on November 21, 1996,because of a propane gas leak, a commercialbuilding in San Juan, Puerto Rico, exploded.Thirty-three people were killed, and at least 69were injured.

The building was in Rió Piedras, a shoppingdistrict in San Juan. The structure was a six-story mixture of offices and stores owned byHumberto Vidal, Inc. The company’sadministrative offices occupied the third, fourth,fifth, and sixth floors, and the first and secondfloors housed a jewelry store, a record store, anda shoe store.

The National Transportation Safety Boarddetermines that the probable cause of thepropane gas explosion, fueled by an excavation-caused gas leak, in the basement of theHumberto Vidal, Inc., office building was thefailure of San Juan Gas Company, Inc., (1) tooversee its employees’ actions to ensure timelyidentification and correction of unsafeconditions and strict adherence to operatingpractices and (2) to provide adequate training toemployees. Also contributing to the explosionwas (1) the failure of the Research and SpecialPrograms Administration/Office of PipelineSafety to oversee effectively the pipeline safetyprogram in Puerto Rico, (2) the failure of thePuerto Rico Public Service Commission torequire San Juan Gas Company, Inc., to correctidentified safety deficiencies, and (3) the failureof Enron Corp. to oversee adequately theoperation of San Juan Gas Company, Inc.

Contributing to the loss of life was thefailure of San Juan Gas Company, Inc., toinform adequately citizens and businesses of thedangers of propane gas and the safety steps totake when a gas leak is suspected or detected.

In its investigation of this accident, theSafety Board addressed the following safetyissues:

• Adequacy of employee training.

• Need for an excavation-damage preventionprogram.

• Adequacy of maps and records of buriedfacilities.

• Adequacy of public education on what to dowhen the odor of gas is detected.

• Adequacy of the oversight of the San JuanGas Company, Inc., from Enron Corp., thePuerto Rico Public Service Commission,and the Office of Pipeline Safety.

As a result of its investigation, the SafetyBoard issues one safety recommendation to theSecretary of the U.S. Department ofTransportation, three to the Research andSpecial Programs Administration, two to thePuerto Rico Public Service Commission, two toEnron Corp., and one to Heath Consultants, Inc.

EXECUTIVE SUMMARY

1

The AccidentAbout 8:30 a.m. on November 21, 1996,

because of a propane gas pipeline leak, acommercial building in San Juan, Puerto Rico,exploded. Thirty-three people were killed, andat least 69 were injured.

The building was in Rió Piedras, a shoppingdistrict in San Juan. (See figure 1.) The structurewas a six-story mixture of offices and stores.Humberto Vidal, Inc., (Humberto Vidal) hadbought the building (the HV building) in 1984,and the company’s administrative officesoccupied the third, fourth, fifth, and sixth floors.The first and second floors of the buildinghoused a jewelry store, a record store, and ashoe store.

The building was on the corner of José deDiego and Camelia Soto. (See figure 2.) TheSan Juan Gas Company (SJGC)1 was the localgas pipeline distribution company. The companyhad a 4-inch cast-iron gas main on de Diego. A2-inch abandoned gas line, a pressurized steelservice pipe, ran from the main to the HVbuilding, about 6 to 8 inches east of the eastwall. The service pipe did not enter the building,and gas had not been used in the building formore than 10 years.

The Humberto Vidal Shoe Store was on thefirst floor, and its front door was on de Diego.The store was owned by Humberto Vidal, whichowned other shoe stores in Puerto Rico, as well.

Week Preceding Accident. --Many peoplelater reported that they had detected the odor ofgas inside buildings and along streets adjacentto the HV building for at least a week before theexplosion.

Several HV employees had worked in thebasement and on the first floor early in the

1San Juan Gas Company, Inc., is a corporation that is whollyowned by Enron Corp. Unless otherwise indicated, the use in thisreport of “the SJGC” refers to the current Puerto Rico Corporationor to any of its predecessor names.

mornings before the air conditioning wasstarted. They had smelled a strong odor that theyidentified as propane gas. Those who hadworked in the basement complained ofdizziness, nausea, and difficulty breathing whilein the basement. One HV employee stated thatmost of the HV employees had smelled the gasodor, as did some customers. She said the odorwas strongest in the basement, wheremerchandise was stored. The manager of the shoestore (who later died in the explosion) told herthat he had advised one of the HV officials thatemployees could not go into the basementbecause of the strong smell of propane gas.

INVESTIGATION

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Figure 1. Accident Location Map.

Some of the employees at the ChickenKingdom had told their supervisor that they hadsmelled a strong odor of gas that came and went.The supervisor stated that he called the companythat serviced his gas cooking equipment and hadall of the equipment tested. No leaks werefound. He stated that the equipment-companypersonnel assumed that the odor must beassociated with gas work going on alongCamelia Soto, since someone was constantlythere checking for gas leaks.

The administrator of the Chicken Kingdomstated that he used a pay telephone to report tothe SJGC that his employees had smelled gas.The SJGC employee receiving the call asked forthe street name. The administrator explained tohim that the smell came and went. The SJGC

employee said the gas company would take careof the problem. The administrator stated that theSJGC employee did not ask for his name, for hiscompany’s name, whether the smell was insideor outside, or any other questions. Theadministrator also said that the SJGC employeedid not tell him what actions he should take.After he made the report, the administrator said,he saw an SJGC truck and SJGC employeesworking in the area and assumed that they hadcome in response to his call. He stated that henever smelled gas in the area while he wasoutside his building. He also said that during theweek or so before the explosion, he had been inJoyería Super Precio, Disco Fiesta, and LaCalifornia stores and had not detected the odorof gas.

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The owner of Pepe Ganga stated that someof his employees had commented to him beforethe explosion about detecting an odor in thestore that they thought might be propane gas. Hesaid that he thought that the odor might havecome from the exhaust fumes of the local bus orother vehicles using the street.

Thursday, November 14 .--According to theSJGC, the first report it received of the odor wason Thursday, November 14. The SJGCdispatcher on duty that morning said that themanager of the shoe store telephoned him at8:15 a.m.2,3 The dispatcher said the manager toldhim that he smelled gas when he opened thestore and that when he went into the basement,he could smell gas, although the odor was notvery strong. The dispatcher stated that herecorded the call and told the manager what hetold anyone who reported smelling gas--leavethe basement door open and try not to turn onany electrical appliances or anything that has todo with electricity.

The dispatcher sent a technician toinvestigate. The technician arrived at the shoestore about 9:30 a.m. and met with a storeemployee, probably the store manager. The twothen walked down the basement stairs, whichwere on the east side of the building (the sidenext to La California). They walked to the northwall of the building (the wall along de Diego),where the manger pointed to the upper right partof the wall and said that the odor seemed to becoming from there. He told the technician thathe smelled gas in the mornings when he enteredthe store. The technician had a gas detector withhim, the kind that is not accurate unless it isturned on in an area that is free of gas. Onceturned on and moved to an area that is suspectedof containing gas, the detector will beep if itdetects gas. The technician did not turn thedetector on until he had been in the store for

2According to computer records of Telefonica de PuertoRico, telephone calls were made to the SJGC on November 14,1996, from the HV building phone normally used by the managerat both 7:43 and 8:22 a.m. The duration of the first call was 83seconds; the second call lasted for 5 minutes and 17 seconds.

3At this time and until after the explosion, it was thedispatcher’s practice to not record leak calls from the same addressmade after one for which a work order had already been issued.The dispatcher did not acknowledge that two calls were receivedfrom the HV shoe store on the morning of November 14, 1996.

about 5 to 10 minutes. When he used it to testthe basement air, the detector did not beep.

According to the SJGC dispatcher, thetechnician spoke with him from the HV buildingand said that he smelled a slight odor of gas outon the street, but not in the basement.

Friday, November 15. --On Friday,November 15, the SJGC sent a brigade to thebuilding. The brigade, consisting of four menand a leader, arrived at 8:15 a.m. The leader hadbeen told by his supervisor that the storemanager was complaining of an odor of propanegas inside the building. When the brigadearrived, the store manager told the leader that hesmelled propane gas in the store, and both menentered the basement by the stairs at the eastwall. In the basement, they walked about 12 to15 feet north from the stairs, and the managertold the leader that they had reached the spotwhere he had smelled gas and that the odorseemed to be coming down from the basementceiling. According to the leader, both he and themanager agreed that they could not smell gas atthat time. The leader later stated that themanager had told him that sometimes in themorning when he opened the store he couldsmell gas. The leader did not have an instrumentwith him for testing the basement atmospherefor the presence of gas, so he went outside totest the underground with a combustible gasindicator (CGI).

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The brigade made about 18 to 20 barholes4

about 4 feet apart in de Diego and, according tothe leader, about 18 to 20 inches deep or deeper.They began east of La California and proceededwest. The leader said that the CGI read 0 until itwas about 2 to 3 feet beyond the east wall of theHV building. In a barhole about 4 feet west, theCGI indicated about 2 to 3 percent on the lowerexplosive limit (LEL) scale.5 As the leaderpumped the CGI to draw in more air from thebarhole, the CGI reading dropped.6 He repeatedthe test several times, and each time he obtainedthe same result.

The brigade continued its survey until it waswithin 20 to 30 feet of Camelia Soto, and theCGI continued to read 0. The leader called thegas company to find out whether any gas pipeswent from the main to the HV building. Thecompany told him about the old line that ranfrom the main into the building. The brigadeexcavated the area over the old line, located it,disconnected it from the main, and plugged theopening of the main. The leader stated that alaborer plugged the open end of the old line.(Inspection after the explosion found that thegas service pipe had not been plugged.)

According to the leader, the brigademembers used a soap solution to test for leaks inthe part of the main they had uncovered. Theydetected no leaks, so they reburied the main andcompacted the soil over and around it. Thebrigade leader stated that he told the manager tocall the SJGC if he again smelled gas.

Monday, November 18. --On Mondaymorning, November 18, an HV employee toldthe manager that the odor of gas in the shoestore was very strong. The manager told her thathe had already spoken with the SJGC and thatthe company was not paying much attention.

4A barhole is a hole that is made in the soil or paving for thespecific purpose of testing the subsurface atmosphere for theexistence of a combustible gas.

5The LEL is the lowest concentration in air of a flammablegas that can be ignited.

6Once a combustible gas is detected, the person operating theCGI draws additional samples from the barhole to see if the CGIreading can be reduced. A reduction in the CGI reading indicatesthat the combustible gas is flowing into the barhole at a rate lessthan the sampling rate.

She later stated that he asked her to go to thebasement with him and that she walked from thestaircase about halfway to the north wall, butcould not go any farther because the odor wasstrong enough to make her dizzy and nauseated.She had to go back upstairs to get some air.

The following day, November 19, was aholiday, and the shoe store was closed.

Wednesday, November 20. --The employeewho had gone into the basement on Mondaysaid that on Wednesday, November 20, the odorwas still present and the smell appeared to beabout the same. She stated that she did not gointo the basement again because she was afraid.According to the SJGC dispatcher, anunidentified person (believed to be the storemanager) called from the HV building a shorttime before 8 a.m. and said that a slight odor ofgas was detectable in the building. Thedispatcher did not record the call. Thedispatcher stated that he used the November 14work order to dispatch a brigade because “theykeep on calling.” He said that, as before, headvised the caller that the building should be leftopen.

The dispatcher said that later in the morninga woman called to report an odor of gas in thebuilding, but he did not take her name since thecompany had already dispatched a brigade.(According to the SJGC’s records, the onlyother call the SJGC received that day from theHV building was in the early afternoon.) Laterthat morning, when the store manager saw anHV official who worked in the building, he toldthe official about the odor. The official told themanager to open the door or get some fans if thesmell got worse, as he did not want customers tosmell the gas. Reportedly, the manager did notfollow the instructions because it would havebeen difficult for him to watch the merchandiseif the door were open.

After the accident, the SJGC operationssuperintendent, the supervisor of the dispatcher,stated that he recalled the dispatcher telling himon November 20 about receiving a complaintfrom the store manager. The operationssuperintendent said that he responded to thecomplaint by dispatching a brigade leader and afive-person crew to investigate. He instructedthem to go into the store and store basement and

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to probe the street outside the store to makecertain that there were no problems inside thebuilding. He stated that he instructed the brigadeleader to take all the time needed to investigatethe report because the brigade leader who wentto the building on November 15 had not gone allthe way into the basement.

The leader of the November 20 brigadestated that he understood that he was respondingto a call reporting a strong odor of gas in thestore. He was aware that other SJGC employeeshad previously responded to a similar complaintand that they had made some barholes. He saidthat when he arrived at the store, he talked to themanager, who, he claimed, said that he was notsure that what they were smelling in thebasement was gas, but that his employees weretelling him that it was gas. The leader said thathe went throughout the basement with themanager checking for any gas pipe or odor ofgas; he said he found neither. He did not use aninstrument to check for gas, but he smelled astrong odor, which he believed to be the odor ofrubber. He said that when he smelled what hebelieved to be rubber, HV employees wereunpacking shoes, readying them to be put onshelves.

According to two HV employees, no oneworked in the basement on November 20because the odor of gas was too strong.Merchandise arriving at the store that day wasstored on the first floor instead of in thebasement. One of the two employees reportedentering the basement to look for merchandiserequested by customers. She said that she triedholding her breath because of the odor. Sheestimated that she was in the basement about 5minutes and became dizzy and nauseated. Theother reported that he was unable to fully enterthe basement because the “fumes” were toostrong.

Another HV employee, a messenger, saidthat he had walked with the store manager andthe leader to the stairs. The messenger said thatalthough he did not go into the basement, hebecame nauseated from the gas odor, as didanother employee. The messenger stated that hestayed at the top of the stairs because the gasodor was too strong, but that the leader and themanager walked about halfway down the stairs.The messenger said that the two men did not go

completely into the basement and that heoverheard the leader say that it smelled like gas.

Propane gas is heavier than air. The leaderstated that he knew that propane gas tends topool and not to rise when it is releasedunderground and that it is therefore necessary toprobe deeper into the soil because pockets ofpropane may be below the gas main. A few daysafter the explosion, the leader said the barholeshis brigade had made were about 12 to 18 inchesdeep. He said that he did not verify the depth ofthe holes except by comparing their depth to thelength of the probe for his CGI. He estimatedthe probe was 2 feet long.

In January 1997, the leader said that hemade new barholes rather than using the oldones because he recalled being instructed neverto use old holes because water might havecollected in them, which could damage the CGI.He claimed that he had observed the barholes tobe about 2 to 2 1/2 feet deep and was aware thatthe gas main was 2 feet deep. He said that,beginning at the intersection of Camelia Sotoand de Diego, on the west side of the building,his brigade made barholes, first at 20-footintervals and then at 10-foot intervals, to theeast until they were about 15 to 20 feet fromMonseñor Torres. He said he had had tworeasons for thinking that he knew where the gasmain on de Diego was: he had had previousexperience with it; another brigade had markedthe location of the gas main with crayon when itwas repairing the service line to La MilagrosaSchool.

The brigade made barholes at 10-footintervals along both sides of Camelia Soto. (Thebarholes on the eastern side of Camelia Sotostarted about 5 feet south of the ChickenKingdom and continued to de Diego. Thebarholes on the western side of Camelia Sotobegan at the Comerical Ubiñas gas service lineand continued to de Diego.) The leader said hehad decided on making barholes along CameliaSoto because he thought there was a gas mainon Camelia Soto and that he had thought thatgas might have migrated from the main onArzuaga or the main on Camelia Soto to deDiego. (De Diego is downhill from Arzuaga.)He said that the crew found no indications ofcombustible gas in any of the holes they madethat morning.

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The leader said that had he known there wasa gas service to the Chicken Kingdom, he wouldhave probed over that line also. He said that heknew that a service line ran to the ComericalUbiñas building because he could see the meter,but he was not aware that a service line ran tothe Chicken Kingdom. He did not call thedispatcher to learn the locations of gas pipes inthe area, nor did he use a pipe locator, the mapsin his truck, or other means to locate the gaslines.

The SJGC operations superintendent latertestified that on November 20, the leaderreported that he had found a power transformerthat was leaking oil in the basement of the HVbuilding. (The leader did not report thisinformation when interviewed by a Safety Boardinvestigator, nor was there a transformer in thebasement.) The operations superintendent statedthat the leader told him that his crew had used asoap-and-water solution to test the locationwhere a gas service had once entered thebuilding (the leader testified that he looked forevidence of gas lines entering the basement andfound none) and at other locations, but found noareas indicating the entry of propane gas.

The leader said that his CGI had been usedby others the previous day and around noon hewondered whether it was operating correctly,since he had not found any indication ofcombustible gas in the barholes. He and the restof the brigade drove to the SJGC shop, wherethey had the CGI tested. It was found to befunctioning properly.

Meanwhile, the HV messenger told the HVattorney that the gas odor was still in the base-ment and, at times, the odor could be detected inthe stores in the building. According to theattorney, she called the SJGC after 1 p.m. andreported what the messenger had told her. Onreceiving her complaint, the SJGC dispatcherinformed the operations superintendent. Heradioed the leader, who was in the shop testingthe CGI, and told him to return to the HVbuilding to check again for gas leaks. He statedthat he instructed the leader to test in alldirections for leaks and to test even further fromthe building because he wanted to know why theHV employees were calling.

The leader and the rest of the brigadereturned to the HV building and re-tested all ofthe holes that had been made that morning.Again, they did not detect combustible gas.About 5 p.m., the brigade returned to the SJGCshop. The brigade leader talked with themaintenance and construction coordinator(MCC) and reported that his testing had notrevealed evidence of combustible gas near theHV building. He also advised that a storeemployee had reported detecting the odor of gasthat morning when the store was first opened.The MCC stated that he did not believe thatthere was a gas leak at the HV building becausehe knew the results obtained by previous crewsand because he trusted his personnel and theinstruments that they used.

Thursday, November 21 .--On November21 about 6:45 a.m., air conditioning contractors(a father-and-son team) arrived to do the routine,monthly maintenance on the air conditionersthat they had been doing for the past 10 years.They met the store manager and the messengeroutside. According to the messenger, themanager opened the door to the store and saidthat he smelled gas. The messenger said hisstomach became upset and he told the managerto call the SJGC because the odor was so strong.The manager turned on the lights, and the fourmen entered the building together. The managerand the contractors walked through the store tothe elevator on the west side of the building.The son (the father died in the accident) laterstated that when he entered the building, he didnot detect any unusual odors but said themanager told him about detecting a strong odorof gas. The three used the elevator to go to thebuilding receptionist area on the fourth floor,where the manager opened the office doors andleft.

According to the son, the building airconditioners usually were not turned on until 8a.m. or later. It was usual for the store managerto turn on all the air conditioning units at theircontrol panels; however, the son stated thatwhen he worked on the basement airconditioner, he would turn the unit on and off asneeded. To perform their work, the contractorswould feel the air conditioner pipes after the airconditioner had run for a while to assesswhether the machine was working properly, and

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as needed, they would wash the compressor andfilters.

An employee who arrived at work betweenabout 7 and 7:10 a.m. said that as she enteredthe building, she smelled the odor of gas, anodor that had been present for the past week anda half. She said the odor was strong enough thatit “went over the top of the regular odor [shoes]of the store.” She recognized the odor aspropane gas because she had a propane gasstove at home. As she did most mornings duringthis period, she mentioned the odor to the storemanager. He told her that he would call the gascompany again that morning� and that he wascontinuing to keep a log of his calls. (His calllog was not found after the explosion.) The storemanager’s brother entered the store, and thethree of them were together until 8 or 8:05 a.m.,when the employee left the building to getbreakfast.

The manager’s brother stated that when heentered the building, he smelled propane gas.The manager complained to him about thestrong odor of gas and told him that he hadbecome dizzy and nauseated. The managerasked him to go into the basement to check onthe odor. The brother walked to the bottom ofthe basement stairs, sniffed the air, and wouldgo no farther because his eyes became irritatedand he could not stand the smell. He ran backupstairs, advised the manager to leave thebuilding, and soon left himself.

The son from the air conditioning contractorteam said that he completed his work on thethird and fourth floors about 7:50 and left thebuilding. He stated that his father beganworking on the fifth floor and was to work allfloors other than the third and fourth. The sonsaid that he was aware of the odor produced bythe shoes stored in the building and of the smellof propane gas from the pipe system. He statedthat he did not detect the odor of gas that day inthe areas he visited.

In the meantime, the MCC had decided tosend a third brigade, which he dispatched at 7.The workmen arrived about 7:30 and parked

7Telephone records on calls from the HV building do notshow a call having been made to the SJGC that morning.

their truck on de Diego, in front of the building.The MCC said he sent the brigade to make surethere was no gas in the building and to learnwhat the HV employees were smelling whenthey opened the building.

The brigade leader reported that he wasgiven no instructions on contacts to be made atthe building and that he had not been told thatthere had been previous complaints or what theprevious SJGC crews had done. He said thatbecause he was not told of the previous actions,he did not take with him any plans or otherinformation about the gas piping in the area. Heknew that there was suppose to be a map of thegas mains in the truck, but he did not considerthe map important because he knew he coulduse his radio to obtain any information heneeded.

The leader said that he did not smell gas onthe outside of the building when he arrived andthat he did not see anyone at the store door. Hebelieved the store had not yet opened becausethe outside roll-up door was halfway up and theinside door was closed.8 At no time did he or hisbrigade members meet with or talk to any HVemployee. Without referring to the gas mainmap in the truck, he went to the barholes he sawin de Diego, beginning in front of the entranceto the HV building and extending west to theintersection of de Diego and Camelia Soto. Hebelieved that the barholes had been made theprevious day by another brigade. He stated thatthe holes were about 18 inches deep and about 6feet north of the curb. He believed theirlocations to be over the gas main because herecalled the location of the gas main from anearlier time when he saw it exposed toreestablish gas service to the school across fromthe HV building. He inserted his CGI probe intothe holes and tested in each. He detected noodor of gas, and his CGI did not register anyindication of a combustible gas.

The administrator of the Chicken Kingdomstated that as he drove past the HV building onhis way to work, he saw the SJGC brigade

8The outside door was a solid metal roll-up door that wasabout 30 feet wide and covered the store entrance and the glassdisplay windows. The inside door was a metal mesh roll-up doorlocated further from de Diego than the outside door, and it waslocated across the approximately 6-foot wide store entrance.

9

working in the area. He said that about a halfhour before the explosion he detected a “little”gas odor in the store when the breeze blew intothe store.

The leader had three new barholes made inde Diego, between the jewelry store and themanholes in the intersection of Camelia Sotoand de Diego. He said that the holes were 18inches deep and about in line with thepreviously made barholes that he had alreadytested that morning. No combustible gas wasdetected in the three new holes. Next he had thecrew make more barholes in the intersection ofCamelia Soto and de Diego. As soon as thebarholes were made, just before 8:30, he usedhis CGI and obtained a reading of 20 percent onthe gas scale, but he detected no odor of gas.

About 5 to 10 seconds afterwards, while he wasstanding on the manhole cover and anotheremployee was making another barhole, theexplosion occurred. The force lifted him into theair and threw him about 15 to 20 feet to thenorth.

People who were in the HV and adjacentbuildings sustained minor to serious injuries.Those on the lower floors of the HV buildingreceived the more serious injuries. The bodies ofthe store manager and the air conditioningservice technician were later found in thebasement. Some people outside and near the HVbuilding were severely injured or killed bydebris propelled by the explosion. (See figure3.)

Injuries

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Title 49 Code of Federal Regulations (CFR)830.2 defines a fatal injury as: any injury whichresults in death within 30 days of the accident.A serious injury is one that requireshospitalization for more than 48 hours,commencing within 7 days from the date theinjury was received; results in a fracture of anybone (except simple fractures of fingers, toes, ornose); causes severe hemorrhages, nerve,muscle, or tendon damage; involves any internalorgan; or involves second-or third-degree burns,or any burn affecting more than 5 percent of thebody surface.

Emergency ResponseImmediately after the explosion, police

officers on Camelia Soto and Arzuaga rantoward the building and began helping the

injured and those trapped on the upper floors.Firefighters at the Rió Piedras fire station,which was about ¼-mile from the HV building,heard the explosion and arrived in a pumpertruck about a minute later. They observed carsturned upside down, injured and dead people inthe street, and devastated buildings, but no fire.They radioed for assistance, and within minutesadditional fire, medical, and police personneland equipment arrived. Firefighters providedfirst aid, removed bodies, and evaluated therisks of entering the building. The Puerto RicoPolice dispatched members of its bomb squad toinvestigate.

At 8:42, the police notified the traumacenter at the Rió Piedras Medical Center, whichinitiated its disaster plan. A triage area was setup at La Milagrosa School.

11

At 8:45, a San Juan Civil DefenseDepartment search and rescue worker, who hadbeen trained in handling gas emergencies, wasdispatched to the scene. When he arrived, hesmelled a strong odor of gas, but did not see anyevidence of fire or smoke. Dust was still comingfrom the building, and he said he saw injuredand dead people all over the area. He said thatpeople were shouting and screaming and thatalthough he attempted to administer first aid,many victims could not be reached because thedebris and objects falling from the HV buildingmade it dangerous to approach them. The streetsinto the area were narrow and became congestedwith arriving vehicles, hampering traffic flowinto and out of the area.

The Puerto Rico Secretary of Health wasnotified of the accident at 8:50 and dispatchedmedical teams and Mental Health CrisisCounseling personnel. A medivac unit wasdispatched to transport patients as necessary.

The Disaster Preparedness ImprovementDirector of the State Civil Defense arrived about9:00, assumed the role of incident commander,and coordinated the response efforts ofparticipating agencies. At 9:15, the San JuanCivil Defense Department dispatched moresearch and rescue people.

At 10:00, rescue groups entered the HVbuilding, and some areas of the structure beganto collapse. The rescue was discontinued untilthe Department of Housing, which isresponsible for public safety related to thedamaged buildings, arranged for structuralengineers to assess the stability of the building.By 12:30 p.m., the engineers had identifiedthose areas of the building believed to be stableenough for the rescue workers to enter. TheSalvation Army and the American Red Crossalso responded and provided support services.

Representatives of the Federal EmergencyManagement Agency (FEMA) and the PuertoRico Secretary of State, as Acting Governor,9

worked with the incident commander tocoordinate the response. At 2:30 p.m., theActing Governor requested a Presidential

9The Secretary of State serves as Acting Governor at timeswhen the Governor is unavailable.

Declaration that the area in which the explosionoccurred was a disaster zone. The President ofthe United States declared a state of emergency,and a FEMA representative then activated andcoordinated the U.S. Urban Search and RescueTask Force.

A search and rescue team from Bayamon,Puerto Rico, arrived at 4:45 p.m. and joined therescue operations. FEMA gave interim supportto the local response forces by providing flatbedtrucks for removing the damaged vehicles andby providing search dogs to help locate missingpeople. By 6:00, an advance party of the FEMATask Force had arrived, including people fromFlorida, New York, and California. At 7:15,rescue teams reported a strong odor of gas in thedebris of La California store.

At 9, the rescue was suspended againbecause of the instability of the building. Bythat time, 18 bodies had been found, and morethan 80 people had been transported to areahospitals. The building was reinforced atvarious locations and supported by a crane sothat the rescue could continue. Search andrescue efforts went on until December 21, whenthe bodies of the last four people reportedmissing were found, bringing the total of thosewho had died in the explosion to 33.

Survival AspectsAccording to interviews, because most

stores were not yet open, few shoppers were inthe area at the time of the explosion and manyemployees had not yet arrived. The HV buildingusually held 50 or more employees, including 37who worked in the offices, 7 who worked in thejewelry store, 12 who worked in the shoe store,and 2 who worked in the record store. Manyother people worked in adjacent buildings, andhundreds of shoppers and tourists came into orpassed by the building during shopping hours.

DamageThe HV building was destroyed, as was a

major portion of the building that housed LaCalifornia. Several other nearby buildingssuffered moderate to severe damage.

12

The first, second, and third floors of the HVbuilding were shattered, and they dropped intothe basement, as did portions of the fourth floor.The fifth and sixth floors remained relativelyintact. The building’s structural columns andbeams were severely damaged, and the PuertoRico Housing Department declared the buildingunsafe and arranged for it to be demolished.

The estimated property damage wasapproximately $5 million. Enron Corp. (Enron)10

estimated its property damage as less than$50,000. Humberto Vidal estimated propertylosses to be more than $3.5 million for thebuilding. The estimates, however, did notinclude the following items: Enron’s loss ofsales during the many months that the gassystem was not in service as a result of theaccident, the expenses Enron incurred duringthe accident investigation, and Humberto Vidalmerchandise and business interruption loses.

The combined cost of the damage done toadjacent buildings was estimated to be morethan $1 million, which did not include themoney lost by the businesses that could notoperate for several months after the accident. Noestimates are available about the cost of thedamage done to motor vehicles, the cost ofdamage done to windows in buildings onadjacent blocks, or the costs incurred by theCivil Defense, FEMA, the Bureau of Alcohol,Tobacco, and Firearms (ATF), and the PuertoRico government agencies that responded to theemergency.

Personnel InformationDispatcher. --The dispatcher who received

the leak complaints from the HV building onNovember 14 and 20 had been a dispatcher for26 years and an employee of the SJGC for about27 years. He stated that his knowledge about hisduties was gained through on-the-jobexperience. During 1995 and 1996, he had hadtraining on how to complete the paperworkrelated to his job, and he had been givenpamphlets to read about the SJGC’s procedures.He stated that the bulletin board at his

10Unless otherwise specified, Enron is used to refer to theEnron Corp. or to any of its predecessor names, such asInterNorth, Inc.

workstation had all the emergency-responseinformation he needed.

Technician. --The technician who respondedto the leak complaint on November 14 hadworked for the SJGC for 28 years. In addition toresponding to leak complaints, he installedstoves and read meters. His on-the-job traininghad included his being told how to useequipment to detect gas and that responding toleaks is a first priority. His primary trainer hadbeen the assistant superintendent of operations,who, in 1996, trained the technician on the useof a gas detector. The training consisted of in-the-field training in the use of the instrument.The technician was not tested.

He described his training as consisting ofthe assistant superintendent of operationsgetting together the four people responsible forchecking gas leaks and installing stoves andshowing them how to use the instrument andhow to check the instrument with gas.

First Brigade Leader. --The brigade leaderon November 15 had worked for the SJGC forabout 40 years. He stated that he did not take theleak survey training given in January andDecember 1996. During 1995 and 1996, he hadbeen trained in plastic pipe fusion welding,using a gas detector, and the SJGC’s emergencyprocedures. He had not been tested.

Second Brigade Leader. --The brigadeleader on November 20 had been employed bythe SJGC for about 4 years. He had previouslyworked for 15 years with a company thatinstalled fire sprinklers. He stated that at theSJGC he supervised the work of laborers andwas a pipe fitter. His supervisor, the assistantoperations superintendent, had trained him inusing the CGI. The superintendent taught himhow to test the CGI for accuracy. He was nottested after his training; based on the assistantoperations superintendent’s observations of hiswork, he was allowed to perform field leaksurveys using a CGI.

Third Brigade Leader .--The brigade leaderon November 21 had been employed by theSJGC for 4 years. He began as a laborer, aposition which he still held at the time of theexplosion, but he was also being trained andused as a brigade leader. He had functioned as a

13

brigade leader on several occasions before theexplosion. He stated that he had not been trainedin being a brigade leader and had not been testedto determine whether he understood what thejob entailed. He took field training on the use ofCGIs in January 1996, but did not have to take awritten test. He did not participate in theDecember 1996 leak survey training.

MCC.--The MCC had worked for the SJGCfor about 5 years and had held his MCC positionfor about a year. Before that, he was a plantoperator. In his present position, he visitedconstruction sites, estimated what was needed,assigned a brigade to the work, told the brigadewhat equipment it would need, talked to thesupervisor about the work to be performed, andanswered the supervisor’s questions. Theprojects he coordinated included repairs andleak surveys. He also tested the CGIs to ensurethat they were functioning and registeringcorrectly. He stated that he had attended theDecember 1996 leak survey training and wastested afterwards. He stated that in that training,he had been taught to make barholes to a depthof 18 inches and to deepen them if combustiblegas was detected.

Assistant Operations Superintendent .--The assistant operations superintendent hadbeen employed by the SJGC since 1975. He hadtaken his present position in September 1996after several months of taking on-the-jobtraining from the operations superintendent,who was also being trained for his position. Hehad previously been a brigade leader. Theoperations superintendent evaluated his work.He had a copy of the SJGC’s Operations andMaintenance Manual (O&M Manual) at hiswork station, but he had never been tested aboutit. He stated that although the SJGC requiredsupervisors to read the procedures completely,he had not read either the entire manual or all ofthe portions that pertained to his job. He and theoperations superintendent were responsible forchecking supervisors in the field to ensure thatthey were performing their work correctly. Theoperations superintendent evaluated theperformance of the assistant operationssuperintendent, but he did not know whether theevaluation was written down. He participated inboth the late 1995 and the December 1996 leaksurvey training. Written tests were not given for

the 1995 training, but were for the December1996 training.

Operations Superintendent .--The opera-tions superintendent, who at the time of the ac-cident was being trained for his position, hadbeen employed by the SJGC since 1968. He be-gan as a draftsman’s helper, and most of hisknowledge had been gained through on-the-jobtraining. He had been the operations superinten-dent since the end of April 1996 and had overallresponsibility for operating the gas system. Hestated that he had attended the classroom por-tion of the 1995 leak survey training, but not thefield portion. He had other assistants, such ashis assistant operations superintendent and theMCC, there during all of the training. Since the1995 training, he had taken more leak surveytraining in December 1996. During 1995 and1996, Enron provided him with training ondealing with reporters, productivity, organizinghis time, delegating authority, and developingpotential in himself and others. For his trainingon the SJGC’s practices and procedures, he said,he had been given a copy of the O&M Manualand told to study it. He kept a copy of the man-ual in his office. He was aware that the manualcovered policies and procedures related to workhe supervised, but he had never been tested anddid not discuss with the employees that he su-pervised their knowledge of the information inthe manual. He had had conversations with thegeneral manager about what was in the manual,and he had conversations every morning whenhe met with his supervisors to discuss the workfor the day and the relevant SJGC procedures.

Safety Manager .--Before July 1990, thesafety manager had had no experience withpipeline or propane-gas operations. From July1990 to August 1992, he had worked for thePuerto Rico Public Service Commission (PSC).During his first year with the PSC, he was givenon-the-job training on inspecting companies thatbottled and sold liquid gases. In his second year,he received on-the-job training from the PSC’spipeline inspector on inspecting the SJGC’soperations. He stated that the training continueduntil he learned enough to make the inspectionson his own. In the meantime, he had attended a1-day session conducted by the Office ofPipeline Safety (OPS). He stated that whilesome of the session involved generaldiscussions, more of it involved listening to

14

someone from the U.S. Department ofTransportation (DOT) explain the application ofpipeline safety regulations. Participants were nottested at the end of the session. Of his 2 yearswith the PSC, he said, about 60 percent of histime involved being trained in bottled-gas andpipeline operations.

In September 1992, he began working forthe SJGC as the safety manager. He worked forthe engineer who operated both the SJGC andPro Gas Co. (a bottled gas company affiliatedwith Enron). As safety manager, he stated, hewas responsible for personnel safety in both thefield and the office, for gas pipeline safety, andfor public safety as it related to the gas system.He was responsible for changing the emergencyprocedure, updating the contact list,investigating accidents, familiarizing employeeswith the operations manual, working withsupervisors to help reinforce procedures, andadministrating the Federal drug and alcoholtesting. He had read most of the O&M Manualin detail, but he had never been tested orotherwise evaluated on his understanding of it.

In both January and December 1996, hetook training in surveying for leaks. In October1996, about a month before the accident, hetook a course at the Florida Gas Transmissionschool on advanced distribution; he was testedat the end of the course. For 5 to 6 years beforethe accident, he had been going to college toearn a degree in industrial engineering with amajor in quality and safety. He had completedhis course requirements in 1995 and, at the timeof the explosion, was working on his thesis.

General Manager.-- Before working forEnron, the general manager had been an auditorfor two consulting companies: Brown & Rootand Arthur Andersen. He joined Enron in 1987in an auditing group of an Enron affiliatecompany, where he became the director forcommercial development.

In October 1995, he became the generalmanager of the SJGC, and he reported to thepresident of the SJGC, who also was anexecutive of an Enron affiliate company. Heserved as a corporate administrator responsiblefor operations, safety, human resources, andfinances. He had no pipeline operatingexperience, and as the on-site leader of the

SJGC, he viewed his role as one of allocatingresources in a way that would best satisfycustomers’ needs. He stated that he consideredSJGC operations a part of his overallresponsibility, but acknowledged that he had torely heavily on the pipeline people that Enronplaced in other leadership and managementpositions. He stated that he allocated resourcesfor functions to be performed but had to rely onthe technical expertise of the operationssuperintendent and the safety manager to ensurethat the functions were correctly performed.

The general manager stated that when thesafety director proposed changes in the manual,he would call someone at Enron headquarters toreview the proposed change and help him assesswhether the change should be made. Similarly,if the operations superintendent and the safetymanager differed on an issue related to theirresponsibilities, he, the general manager, wouldcontact someone with Enron to assist him inmaking a decision. He was not aware that such asituation had occurred.

Concerning the hiring of consultants for theSJGC, the general manager stated that he did notaward contracts, that contractors were paid byEnron, and that after paying them, Enron billedthe SJGC.

Fatigue .--The members of the brigade whoresponded on November 21 had had a normalamount of rest (approximately 8 hours) the nightbefore. The crew work schedules for the 2weeks before the explosion showed normaldaytime work hours, a 40-hour work week, andno changes in work shift.

TrainingSJGC Training.-- Federal and PSC regula-

tions did not require training for many jobs andtasks for gas pipeline employees. Employeeswere trained at the discretion of the SJGC’smanagement. According to the general managerand the operations superintendent, employeeswere selected for training in operationsaccording to what their regular duties were orwhether they might have to back up operatingpersonnel. Some supervisors were included inoperations training. The SJGC did not havegeneral or individual training plans for itsemployees.

15

The general manager acknowledged that hewas responsible for employee training, but be-lieved that his role was primarily logistic. Thatis, he was responsible for making sure that whenan employee was being trained, the tasks thatthe employee normally did were done by some-one else. The general manager stated that hesometimes recommended training for particularemployees, distributed training catalogs, anddiscussed with the operations superintendentwho should take what training, but that he reliedon the operations superintendent as having theprimary responsibility for recommending train-ing. He also stated that he relied on consultants,such as Heath Consultants, Inc., (Heath), forrecommending the type of training a given em-ployee might need. He said that he did someevaluating of the quality and adequacy of train-ing given to the SJGC employees, but had torely on other Enron resources to evaluate thetechnical adequacy of the training.

The general manager stated that in his timewith the SJGC, the company had not had aprofessional assess the company’s trainingneeds or decide on the most effective means ofdeveloping training for its employees.

He said that when consultants who did notspeak Spanish trained employees, he made surethe consultants had adequate translationresources. During the Heath training, threebilingual employees helped provide a consensustranslation of the material being taught andhelped convey the information to Spanishspeaking employees. The general manageracknowledged that the process was far fromperfect.

Enron had a documented skill-based payprogram for its employees, but the program wasnot available to the SJGC employees because oftheir union contract. Enron also had a computer-based training program, which was not used bythe SJGC employees, and it had access toclassroom training on gas distribution throughthe Florida Gas Transmission School, whichsome the SJGC employees had attended. (Seealso appendix D.)

Leak Survey Training.-- At Enron’s request,on November 28, 1995, Heath proposed that itprovide specialized expertise and function as anadvisor and trainer for SJGC personnel in order

to improve the leakage control program. Theproposal called for a ½-day classroom session ingas leak surveying and gas pinpointing and 12days of hands-on training in leak surveytechniques, including barhole testing, leakindication, leak classification, and leakreporting. A January 8, 1996, letter from Heathto Enron broadened the original proposal so thatspecialized training and assistance in variousaspects of the leakage control program would beprovided. The project team would consist of atechnical manager as the on-site supervisor, aleak pinpointing instructor, and a leak surveytechnician, who would be assigned primarily toleak surveying but would advise SJGCpersonnel on other issues concerning leakagecontrol. Heath would conduct hands-on trainingfor a minimum of 3 months. Heath’s proposalwas revised later to include 1 day of classroomtraining in leak pinpointing and 8 days of hands-on pinpointing training. All work was proposedto begin on January 15, 1996.

At Enron’s request, Heath began inDecember 1995. Heath’s technical manager metin San Juan with SJGC management. Theydiscussed the goals of the proposed project,reviewed the procedures and guidelines forsurveying leaks, and established theorganization, rotation, and responsibilities foreach of the trainees. The technical manager thenconducted a ½-day informal classroom reviewwith the employees who were to be trained. Theinstructional material given to the employeessaid, “When conducting tests for leakage onburied petroleum gas systems, it is essential thatsamples be taken at or near the pipe, in thebottom of the ditch lines and at low points ofsubstructure.”11 The technical manager also gavehands-on leak survey training. At the end of thesession, he and the SJGC’s general managerreviewed the field activities conducted betweenDecember 5 and 19.

The technical manager said that the brigadeleaders knew the properties of propane gas,understood how to lay out barholes, andunderstood that barholes had to be drilled to thedepth of the gas lines. He said:

11GPTC Guide for Gas Transmission and DistributionSystems, Appendix G-192-11A, “Gas Leakage Control Guidelinesfor Petroleum Gas Systems.”

16

They needed to understand, you know,the procedures to go through to do thesurvey, and what they were trying toaccomplish in doing it [the survey]. It’sa labor-intensive type of survey, andyou need people who have a keeninterest in wanting to be out there doingit. They all knew what to do, but not allof them had the interest. Well, some ofthem would rather be digging ditches.

He also said that even though the brigadeleaders knew what to do, only one showed anyinterest in leakage surveys. The technicalmanager stated that some of the SJGC laborersdid not make the barholes to the depth of the gasmain and had to be re-instructed. Some, he said,were reluctant to follow instructions and had tobeen re-instructed repeatedly about the depth towhich the barholes had to be made.

During January 1996, the technical managerconducted a ½-day training session onpinpointing gas leaks and spent most of themonth with three of the SJGC crews working inthe Old San Juan area. The crews receivedhands-on training in pinpointing and surveyingleaks. Heath continued to provide the SJGCemployees with hands-on training during thesurveys they conducted between January andApril.

Gas Company OperationsGas Distribution and Ownership .--The

first gas pipeline system in Puerto Rico wasinstalled in 1912. The gas system was initiallyowned by the Puerto Rico Gas Company, and itdistributed gas manufactured from coke or coal.Eventually it converted to a propane/air system.The system was composed of cast-iron pipe withsteel service lines and was not coated orotherwise protected against corrosion. Later,plastic coated steel pipe was installed. Thenewer pipes were made of plastic, and the SJGChas been replacing some of the older mains andservices with plastic.

Enron owns the SJGC, and the SJGC’sstock is wholly owned by Enron; itsheadquarters are in Houston, Texas. Enron wasincorporated as Northern Natural Gas Companyon April 25, 1930, in Delaware. In 1980, thecorporate name was changed to InterNorth, Inc.;

and in 1986, it was changed to Enron Corp. Onor about January 3, 1985, PetrolaneIncorporated sold all outstanding stock of theSJGC, then a Delaware corporation, to TheProtane Corporation; and it, in turn, on the samedate transferred the assets to InterNorth, Inc.The SJGC continues to be managed andoperated by its own slate of directors andofficers, and its chairman is the CEO of anEnron affiliate operation.12

The SJGC distributed a 60-percentpropane/40-percent air mix to customers in thegreater San Juan area through about 220 milesof gas mains, both low-pressure (1/4 psig) andhigh-pressure (20 psig) piping systems. Thelow-pressure system that served Rió Piedrasconsisted primarily of about 6 miles of 4-inchdiameter cast-iron gas mains and 3.2 miles ofmostly 1 ¼ inch diameter galvanized steelservice lines and served approximately 500customers. The 1 ¼ inch inactive bare steelservice lines to the Sbarro on Arzuaga and to theHV building were connected to 4-inch cast-ironmains and not protected from corrosion.Additionally, the steel tee section connecting theplastic gas main on Camelia Soto to the servicelines for the Chicken Kingdom and forComercial Ubiñas was not protected againstcorrosion.

Pipes and Ducts Installed on CameliaSoto. --More than 20 pipes and conduits werebeneath Camelia Soto, some meant for futureuse, some being used, and others that had beenabandoned. The conduits meant for future useincluded 4-inch and 2-inch polyvinyl chloride(PVC) plastic pipes of undetermined ownershipand purpose. The pipes and conduits that werein use included the two water mains, a sewermain, a plastic gas line, telephone conduits, andelectric conduits. The abandoned pipes andconduits included a gas main, electric conduits,sewer laterals, and water service lines. Many ofthe abandoned pipes and conduits had not beenplugged or otherwise sealed, which would haveprevented them from being paths for gases thatmight have entered the soil. At least five of the

12Enron has numerous organizations, many of which useEnron in their name and which can or do provide various servicesto other Enron affiliates. For simplicity, such organizations areoften referred to as Enron affiliate companies.

17

conduits and pipes beneath Camelia Sotoentered the HV building beneath the floor of themeter room at the southwest corner of thebuilding. The meter room floor was raised about2 feet above the first floor of the HV building,and the space beneath was filled with gravel.From the gravel-filled space, electrical conduitsentered the HV basement.

According to the SJGC’s records, inFebruary 1985, the SJGC installed a 1 ¼-inchdiameter polyethylene (PE) plastic pipe alongthe west side of Camelia Soto. It ran about 2 to3 feet east of the west curb. Some time later, theline was extended south by using PE plastic pipewith PE socket fusion fittings. The extended linecrossed Camelia Soto to provide service to thebusiness that had occupied the space that theChicken Kingdom occupied at the time of theexplosion. To cross Camelia Soto, the line hadto change direction, which was accomplished byusing a 90-degree plastic “ell” socket fusionfitting.

In 1991, the Puerto Rico Aqueducts andSewer Authority (PRASA) installed a 16-inchdiameter water transmission pipeline underCamelia Soto. The PRASA’s records indicatedthat the PRASA had given the SJGC advancenotice that it would be working in the area ofgas pipelines. The SJGC’s maps in thePRASA’s files for this project showed that a 4-inch diameter gas main under Camelia Soto wasabout 2 feet east of the west curb and ranparallel to the proposed water line. ThePRASA’s files had no information about the PEplastic line that the SJGC had installed in 1985.

In 1992, the Puerto Rico TelephoneCompany modified its facilities under CameliaSoto west of the HV building. The companyhired a contractor to install PVC ducts parallelto the west curb. The contractor’s projectsupervisor said that before the work was begun,the telephone company conducted at least threepre-construction meetings to inform governmentagencies and utilities about the planned work toensure that the work was coordinated. He statedthat at one of these meetings, the SJGCdistributed copies of its pipeline maps for thearea and provided telephone numbers to callshould there be any problem. He said the SJGCsaid that the maps showed the locations of itspipes, but, based on his recollections, the maps

did not show all pipe locations accurately. (Seealso Tests and Research.) He did not recall theSJGC representative providing information onhow to work safely around the pipeline, nor didthe gas company mark the locations of its pipesin advance of the excavation work.

The project supervisor said he first learnedthat there were gas pipes in the path of hisproject when he found a gas line in anexcavation near the south side of the HVbuilding. He called the SJGC and was told thatthe pipe was an old, unused one. When workingon Camelia Soto, he first learned of theexistence of a small plastic pipe when hisbackhoe operator severed it. He stated that henotified the SJGC and that the gas companyresponded very quickly to repair the damagedpipe. He recalled that the SJGC crew supervisorstated that the company probably wouldabandon that section of gas line in the future.The project supervisor recalled that due to theexistence of the gas line, he had to alter hisconstruction procedures by placing some ductsside by side, rather than on top of one another.During the project, he said, he called the SJGCabout five times, and the SJGC had to repairabout three leaks. He said that he often had touse his own excavation equipment to help theSJGC, as its employees did not bring a backhoe.

Public Education .--The SJGC O&M Man-ual did not explain how the company would in-form its customers and the public about the haz-ards of propane gas. The manual did not explainhow readers could recognize hazardous condi-tions or how they could report problems to thegas company. About 8 months before the acci-dent, in January, the SJGC had started a cam-paign to educate the public about what to dowhen the odor of gas is detected. The SJGC be-gan making announcements in local newspapers,distributing flyers, including inserts withcustomers’ bills, and making presentations tocommunity groups. The SJGC explained in apamphlet that odorants are added to gas to makeits presence detectable. The pamphlet was inSpanish and was distributed to all customers.

The flyers that the SJGC distributed to thepublic before the accident explained that when aperson smelled a strong gas odor, he should:

• Evacuate the area immediately;

18

• Not use any electrical appliance;

• Not smoke or use matches;

• Not connect or disconnect any appliance orelectrical plugs, or any other source ofignition or flame;

• Not try to repair or stop the gas leakhimself;

• Move to a safe place against the wind andwait for the arrival of the gas companypersonnel; and

• Inform others in the area about thepossibility of a gas leak.

The pipeline safety regulations, 49 Code ofFederal Regulations (CFR) 192.615, requirethat operators establish a continuing educationprogram to enable customers, the public,appropriate government organizations, andpeople engaged in excavation-related activitiesto recognize a gas pipeline emergency for thepurpose of reporting it to the operator orappropriate public officials. The regulationsrequire that the education program reach allareas in which the operator transports gas andthat it be conducted in English and in the otherlanguages commonly understood by thepopulation in the operator’s area. The operatormust establish and maintain liaison withappropriate fire, police, and other publicofficials for the purposes of (1) learning theresponsibility and resources of eachorganization that may respond to a gas pipelineemergency; (2) acquainting the officials with theoperator’s ability to respond to a gas pipelineemergency; (3) identifying the types of gaspipeline emergencies about which the operatorwill notify the officials; (4) and planning howthe operator and officials can engage in mutualassistance to minimize hazards to life orproperty.

Emergency Procedures. --Section 7.02 ofthe SJGC’s O&M Manual listed the names andtelephone numbers of employees and agenciesto contact in case of an emergency. The list hadnot been updated since 1993. In front of theEnglish version of the manual’s index was acollection of memos. The memos were notindexed to sections of the manual, and they

covered such subjects as safety, payroll,maintenance, emergency procedures, operations,estimating, suspension of service, and parking.Some of the memos were not dated; the dates onthe other memos varied from about 1985 to1993. One of the longer memos was undated andexplained the procedure to be followed inemergencies. It included a telephone list similarto the list in Section 7.02.

The O&M Manual told employees to takeimmediate and effective action in allemergencies, such as when gas was detectedinside or near buildings, when there was a fireor explosion in or near gas lines, or when therewas a natural disaster. It said that in anemergency, the field supervisor was responsiblefor determining which of the following kinds ofaction were appropriate: evacuating, eliminatingall sources of ignition, ventilating the area,locating the gas leak, repairing the gas leak,coordinating the work with firemen, police, civildefense, etc., and helping control traffic andcrowds in the area.

According to the manual, “As soon as adispatcher or shift guard receives the call orreport he/she should prepare a job order,indicating the name of the person who called,his/her address, and the time and date of thecall.” The receiver was to record, in as muchdetail as possible, the matter that was reported,determine the risks that were involved, anddecide whether immediate action was necessary.If an investigation was necessary, it was to bedone by the shift mechanic. If the shift mechanicinvestigated and could not fix the problem, hewas to tell either the dispatcher or the guard,who was then responsible for telling the shiftsupervisor.

According to the dispatcher and thecustomer-service representatives, callers wereasked about the location and intensity of the gasodor. The receivers did not rely on a checklist ofquestions to gather the information. Thedispatcher stated that he gave safety tips frommemory and usually gave callers more informa-tion than was provided on the safety informationsheets that were given to the dispatchers andcustomer-service representatives. The safety tipsprovided included:

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• If you perceive a strong gas odor, evacuatethe area immediately.

• Do not use electrical appliances.

• Do not disconnect any appliance orelectrical plugs.

• Do not use any other source of ignition orflame.

The dispatcher said that callers were nottold to evacuate a building because the SJGCdid not want to cause unnecessary panic until abrigade determined whether there was a gasleak. Also, customers were not informed underwhat conditions they should notify localemergency-response agencies before thebrigades arrived on scene.

Leak Surveys .--The O&M Manual calledfor a leak survey each year in high-density orcommercial locations. All other areas of thedistribution system were to be inspected forleaks at least every 5 years. An annual report ofthe survey, indicating the miles of pipeinspected and the cost, was to be sent to theSJGC’s general manager.

According to the SJGC management, nopart of Rió Piedras had been surveyed for leaksbetween 1994 and 1996. In 1996, the SJGCsurveyed the area with a portable flameionization detection unit that sampled the airfrom barholes in the pavement. The surveyuncovered 55 leaks, which were then repaired.Thirteen of the 55 leaks were in the 12-blockarea around the HV building. None of the leakswere adjacent to the HV building.

Previously, in a December 9, 1993, letter,the OPS encouraged the PSC to use its civilpenalty authority for violations discovered at theSJGC, an example being the SJGC’s failure tosurvey Rió Piedras for leaks. The PSC fined theSJGC $500.

During the October 1996 inspection of theSJGC, the PSC noted "unsatisfactory perform-ance about the SJGC’s surveillance andpatrolling of its gas system. The PSC markedthe SJGC’s leak survey program satisfactory;however, the PSC gave the SJGC unsatisfactory

for its program of surveying business areas, suchas Rió Piedras, each year for leaks.

The pipeline safety regulations, 49 CFR192.723, require gas operators to surveybusiness districts each year for leaks and tosurvey other areas as often as necessary but atleast every 5 years. In doing the surveys, theoperators must use leak detection equipment.

Odorization.-- -Section 5 of the O&MManual stated that because of the variety ofodorants available, only the engineeringdepartment had authority to buy odorant.According to the SJGC’s organization chart, thecompany did not have an engineeringdepartment. Records show that the propane theSJGC received from its supplier contained EthylMercaptan as an odorant, but do not indicatehow much odorant the propane contained. TheSJGC added C.S. Captan odorant; the SJGC’sprocedure did not specify the use of C.S.Captan, nor was the company able to produce adocument that authorized the use of C.S.Captan.

The SJGC’s procedures required thatodorant intensity be tested monthly. The SJGCrecorded the amount of odorant and number ofcubic feet of gas/air entering the system daily;but it did not calculate the injection rate todetermine the amount of odorant added to thegas. Records indicate that the SJGC beganconducting weekly odor intensity tests inJanuary 1996.

The O&M Manual did not specifyacceptable minimum and maximum rates ofodorization, establish the acceptable character-istics of the odorant injected, or establish an ac-ceptable range for odor intensity readings ob-tained during tests. A review of the odorant snifftest records for the 3 weeks before the explosionshowed four system locations being monitored,including one for the Rió Piedras area. Recordsindicate that the gas odor was detectable whenthe propane gas level was at 1/5 the LEL ofpropane gas.

The pipeline safety regulations, 49 CFR192.625, required that gas in distribution linesbe odorized so that the gas could be detectedreadily by a person with a normal sense of smellwhen the concentration of gas in air was 1/5 of

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the LEL. The regulations also required operatorsto ensure the proper concentration of odorant bysampling the gas periodically. The PSCinspected the SJGC’s odorization practices in1996 and determined that they were consistentwith the requirements.

Excavation-Damage Prevention Pro-gram .--In March 1983, the SJGC added Section8.14, “Program for the Prevention of Damagesto Gas Lines by Contractors,” to its O&M Man-ual. The program required the SJGC to:

• Maintain an updated list of excavationcompanies;

• Communicate with the contractor about theexistence of the SJGC facilities immediatelyupon learning of an excavation project;

• Provide, if necessary, at no cost to thecontractor, plans, sketches, and informationto help him locate the buried gas facilities;as well as mark the location of the buriedfacilities;

• Request that companies planning excava-tions call the SJGC;

• Inspect the project so the integrity of the gasconduits can be verified;

• Survey for leaks to verify that there are nogas leaks in the project area.

Copies of this section of the O&M Manualwere to be sent to the PSC; 20 contractors; theSan Juan Regional Office of the Department ofTransportation and Public Works; theDepartment of Public Works in San Juan,Guaynabo, Carolina, and Bayamon; the ElectricEnergy Authority; the Aqueducts and DrainageSystems Authority; the Puerto Rico TelephoneCompany; and the Fire Services of Puerto Rico.

On August 8, 1996, a senior safetyrepresentative of an Enron affiliate companywrote to the SJGC’s general manager that theO&M Manual should be revised so as to betterprotect the SJGC pipelines from being damagedby contractors and other buried-facilityoperators. The letter recommended that theSJGC:

1. Give the local planning commissions anO&M Manual and a map of the system, andhave the commissions require companies tocontact the gas company before beginningwork;

2. Try to find out about construction before itbegins;

3. Present procedures and maps to theContractors Association membership andmake a presentation, if possible, at ameeting;

4. Work with upper management at the utilitycompanies to address the excavationproblem;

5. Buy more pipeline markers;

6. Develop a public education program andinitiate training classes for the public.

The pipeline safety regulations, 49 CFR192.614, required pipeline operators to have awritten program for preventing damage topipelines from excavation activities, includingexcavation, blasting, boring, tunneling,backfilling, removing aboveground structures byeither explosive or mechanical means, and otherearth moving operations. The 1996 PSCinspection report on the SJGC operations notedthat the SJGC had a satisfactory program.

Gas Maps and Records. --The SJGCmaintained drawings showing the locations ofgas mains, valves, and equipment related to thegas mains. It kept information related to gasservice lines on cards filed at its San Juanoffice. For the most part, the cards had suchinformation as the gas meter’s size and serialnumber, the customer’s name and address, and asketch showing the service line size, materialsused, and location. The records of some gasservice lines did not contain sufficientmeasurements and references to identify the gasservice lines as they currently existed.

The maps that the SJGC provided after theexplosion showed the gas line on Camelia Sotobeing constructed of 4-inch cast-iron pipe. Themap had not been updated to show that the linehad been replaced with plastic pipe. The SJGCcould not locate the service line card for the

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Chicken Kingdom until several days after theexplosion; the card did have detailedinformation about the service line and itslocation.

The pipeline safety regulations did notrequire operators to have maps or records thatshow the locations all major pipeline systemcomponents. Operators were required to haveand maintain maps and records only on somespecific gas system facilities, such as corrosioncontrol systems.

Corrosion Protection .—Section 4.0,“Cathodic Protection Policy and Practices,” ofthe O&M Manual was dated August 1979. Thesection required that the supervisor in charge ofcathodic protection systems supervise the designand installation of the systems. The SJGC’sorganization chart did not show such asupervisor, nor did a revised organization chartthat was made available 2 days after theexplosion.

According to the manual, each pipeline wassupposed to be protected by anodes and testedeach calendar year. The manual said that ifannual testing was not practical, protected mainsand services could be tested in sections of notmore than 100 feet. If the section method oftesting was used, at least 10 percent of the totalprotected lines had to be tested each year so thatthe total protected system would be tested in a10-year period.

The SJGC had no records of the corrosionleak history in Rió Piedras or of having done anelectrical survey in the area. According to theSJGC, it used its leak survey and repair recordsin lieu of an electrical survey to identify theeffects of corrosion on its lines. However, theSJGC did not perform the leak surveys as oftenas required by gas pipeline safety regulations,nor was there any documentation of repairrecords being correlated to leak survey findings.

A consultant reported in 1984 to Enron, be-fore Enron acquired the SJGC, that the corro-sion control system needed to be upgraded. In1985, Enron retained another consultant, whoproposed a cathodic protection system. The con-sultant recommended electrically insulatingportions of the piping system, performing elec-trical surveys of the system, and setting up a

cathodic protection monitoring procedure and anemployee training program. A cathodic pro-tection survey and master plan were prepared.The plan included taking such steps as insulat-ing the system, increasing the electrical outputat rectifiers, installing corrosion test stations andanodes, and training employees in cathodicprotection. The gas company could produce fewrecords of tests or additional corrective actiontaken after 1986 related to achievement of theconsultant’s recommendations.

The pipeline regulations, 49 CFR 192.453,required that the design, installation, operation,and maintenance of cathodic protection systemsbe carried out by, or under the direction of, aperson qualified by experience and training inpipeline corrosion control methods. The PSC’s1996 inspections of the SJGC noted numerousunsatisfactory conditions relative to corrosioncontrol procedures, practices, testing, records,and levels of cathodic protection.

Plastic Pipe .--Section 2 of the O&MManual listed the following requirements for thesafe installation of plastic pipe.

• Pipes should be laid on ground free of rocksthat could damage the pipes; the groundshould be firm and provide good continuoussupport;

• Pipes should be surrounded by 4 inches ofsand or loose dirt without rocks when laid intrenches; care should be taken not todamage the pipe when compacting soil;

• Pipes should be covered by 30 inches of soilwhenever possible and in no case by lessthan 24 inches;

• Pipes should have a minimum verticaldistance of 12 inches and a minimumhorizontal distance of 24 inches from anyother buried facility, unless approved by theinspector; and

• Pipe sections should be cut with propertools only and should always be cut straight.

Under the SJGC’s procedures, if steel andplastic were being connected by a compressionfitting, the steel pipe was to be cleaned and aspecial nipple for rigidity (stiffener) was to be

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inserted into the plastic pipe. The pipes beingjoined had to be aligned and inserted at least 1/3of the way into the fitting. The fitting had to betightened, checked for leaks, and wrapped withspecial wrapping tape to protect it fromcorrosion.

Postaccident inspections revealed thatlengths of plastic pipe in the gas service line tothe Chicken Kingdom were connected by acompression coupling. After the explosion,investigators examined the coupling: it wasbare, it was not protected from corrosion, theends of the pipe were not evenly cut, stiffenerswere not inserted into the ends of the pipes,rocks, pavement pieces, and other debris werenear the west side of the pipe, the cover over thepipe varied in depth between 1 1/2 and 3 feet,and sand was beneath and adjacent to the part ofthe pipe that was in the area that had not beenexcavated to install a 16-inch water main underCamelia Soto.

Abandoned Services. --Section 6.02 of theO&M Manual was about discontinuing andabandoning gas lines. It said:

As a general rule, the SJGC procedurescall for service lines that are out ofservice for more than 1 year to beabandoned. They are to be physicallyseparated from the main and the openends of services are to be closed usingplugs.

The SJGC operations superintendent statedthat technicians were told that when they wereinvestigating leaks, they were to check forinactive gas services. Any such services were tobe abandoned. Generally, crews closed anabandoned service by using a mechanicalcoupling that had a cap; sometimes they closedthe service with a flexible plastic material that isused to coat pipe.

The assistant operations superintendent saidthat he did not know that the SJGC had a policyabout abandoning inactive service lines.However, he stated, when a customer said thatgas was no longer to be used at a given location,the company normally cut the service at the gasmain and plugged the main.

During the investigation, two gas servicelines, one on Camelia Soto and one on Arzuaga,were found that were inactive and stillconnected to the gas mains. A third inactiveservice line, on de Diego, had been disconnecteda week before the explosion, but the end of theservice line had not been sealed. The inactiveservice on Arzuaga was leaking gas in the areawhere it had been damaged by excavation. Theinactive service at Comercial Ubiñas wasconnected to the main pipe, which had acompression fitting that was leaking gas. Theinactive service for the HV building had beeninactive for at least 6 years before it wasdisconnected, on November 15, 1996. TheSJGC’s records for 1983 through 1995 showedthat of its 12,000 service lines, 4,000 wereprobably inactive but had not been abandoned.

Unaccounted for Gas .--Unaccounted forgas is the difference between the quantity of gasthat enters the gas system and the quantity thatis delivered to customers or used for otherknown purposes. The SJGC reported to the OPSthat it was unable to account for 5.0, 4.7, and3.5 percent of the gas that had entered its systemin 1993, 1994, and 1995, respectively. Thechairman of the SJGC’s board of directorstestified that in 1995 the SJGC had set a goal ofreducing its unaccounted for gas to 5 percent orless in 1996. In 1995, the unaccounted for gaswas about 25 percent, and the SJGC chairmanattributed about 7 percent to billing andmetering problems and the remaining 18 percentto theft.

Meteorological InformationBetween November 14 and 21, the

temperature ranged from 72 to 85 degrees F.Except for November 17 and 18, little rainfallwas recorded during the period. About 0.2 inchof rain was recorded on November 17, andabout 0.8 inch was recorded on November 18.

Medical and Pathological InformationInjuries consisted of abrasions, contusions,

lacerations, fractures, sprains, dust and gasinhalation, friction burns, and multiple bodytrauma. Survivors were triaged at the scene. Ofthe people triaged, 85 were treated at areahospitals. Sixty-nine people sustained injuries;25 injuries were classified as serious. An

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undocumented number of injured people weretreated by private physicians and not seen atlocal hospitals.

The 33 fatalities were autopsied at theInstitute of Forensic Sciences in San Juanbetween November 21 and December 20.According to the autopsy reports, the deathswere caused by traumatic injuries and traumaticsuffocation.

The Caribbean Medical Testing Centercollected urine samples from each of the sixpeople in the November 21 brigade. Because nolaboratory in Puerto Rico is approved to performall required tests, the samples were sent toCorning Nichols Institute of San Diego,California, to be tested for drugs. On November27, all tests were reported negative for drugs.

According to the SJGC, it complied with 49CFR 199, which requires testing of employeeswithin 8 hours of an accident or providing awritten explanation of why the employees werenot tested. The SJGC explained that five of thesix employees were injured and seeking medicaltreatment. The sixth employee was in thecustody of one of the agencies investigating theexplosion.

Tests and ResearchSJGC Pipelines.-- After the explosion,

investigators tested the subsurface of the streetsin the area of the HV building in various ways.They sank barholes as deep as the approximatedepth of the main (2 to 3 feet according to theSJGC’s records) at intervals of approximately10 feet along the gas main and positioned thembetween the gas main and the nearest street curbalong de Diego, Monseñor Torres, and Arzuaga.Because the investigating team did not yet knowthat Camelia Soto had a gas line that was nearthe HV building, barholes were made at 10-footintervals along the east curb of Camelia Sotobetween de Diego and Arzugua and then alongthe west curb from the Comercial Ubiñasservice line northward to de Diego. (See figure4.)

To determine during the early stages of theinvestigation whether propane was present inthe subsurface adjacent to the HV building, theinvestigators collected two samples from each

of the three barholes in which the CGI readingwas 100 percent LEL or greater for propane gas.One set of samples was subjected tocomparative gas chromatography at a locallaboratory, and the results confirmed thepresence of propane in the sample taken from abarhole at the intersection of Camelia Soto andde Diego. The second set of samples wassubjected to analytical gas chromatography, andthe results confirmed that propane was presentin all three barholes and was the majorcombustible gas constituent in two of the three.

After finishing the CGI tests, under thedirection of Safety Board investigators,nitrogen13 was introduced into the gas pipes onde Diego, Camelia Soto, and Arzuaga. (Thenitrogen was under the approximate pressurethat the gas system had been at the time of theexplosion: 7 inches water column.) Those pipesections that did not hold pressure underwentfurther tests designed to identify possible leakareas and determine the leak rate. Nitrogen wasgenerally used to measure the rate of releasefrom the pipe section, and helium was used topinpoint leak locations. Based on the helium testresults, pipe sections were excavated forexamination. If a pipe section was damaged, thesection was removed, the pipe ends were closed,and the remaining pipe was re-tested until itheld pressure, another release point could beidentified, or sufficient information wasobtained to decide that the remaining leaksprobably had had no effect on the explosion inthe HV building.

When the investigators excavated theservice line to Comercial Ubiñas, they learnedthat a steel T-shaped pipe section had been leftin place when the SJGC installed a plastic line.Compression couplings had been used toconnect the T-shaped section to the plastic lineand the Comercial Ubiñas service line. Theinvestigators injected nitrogen into the gas mainat the compression coupling south of theComercial Ubiñas service line and found that ittook a flow of 1.76 cubic feet per minute (105.6cubic feet per hour) into the pipe section tomaintain pressure.

13Nitrogen flow properties are much closer to those ofpropane than to those of helium.

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When the investigators excavated the pipesection, they found that the test medium wasescaping from a crack in the plastic pipe in frontof the Chicken Kingdom. The pipe segment withthe crack was removed for later laboratorytesting, and the remaining segments were re-tested. Nitrogen was then used to determine theleak rates of various portions of the gas linebetween the service to Comercial Ubiñas andthe Chicken Kingdom. (See figure 5.) Thecompression fitting at the Comercial Ubiñasservice was determined to leak at 0.04 cubic feetper minute, and the steel T-section connectingthe plastic leaked 0.02 cubic feet per minute. Noadditional leaks were found south of theComerical Ubiñas service line to the area of thecrack. Therefore, the undisturbed crack in theplastic pipe in front of the Chicken Kingdomwas found to have been leaking at a rate 1.70cubic feet per minute (102 cubic feet per hour).

Further excavation of the Chicken Kingdomgas service line showed that PVC plastictelephone conduits had been installed about 15feet west of the leaking plastic coupling. Theconduits were directly over and in contact withthe gas line, and both the conduits and portionsof the gas line had been buried in concrete. (Seefigure 6.) According to SJGC records, the gasline had originally been installed along the westside of Camelia Soto to a point where it wasacross from the Chicken Kingdom. At thatpoint, the plastic line was shown to make a 90-degree turn, crossing under Camelia Soto andentering the Chicken Kingdom. Excavationrevealed that the service line did not contain a90-degree tee. Instead of making a 90-degreeturn, the plastic pipe changed direction to enterthe Chicken Kingdom by making a longsweeping curve, and the two segments werejoined by a compression coupling. Thesupervisor for the contractor who had installedthe telephone conduits confirmed during hisinterview that he was unaware of any gas linebeneath Camelia Soto because none was shownon the drawings he had obtained from the SJGC.He stated that while excavating with a backhoeto install the telephone conduits, his crew cutthe gas line. He said that he had reported theincident to the SJGC, which repaired the gasline. He said that the plastic pipe ran down thetrench in which the telephone conduits werebeing installed and that SJGC employees hadtold him that the gas line would probably be

abandoned. (See also Pipes and Ducts Installedon Camelia Soto.)

The 4-inch diameter gas main on Arzuaga,from a point east of Camelia Soto to a pointabout 1 ½ blocks east of Monseñor Torres, anda short segment of main on Camelia Soto southof Arzuaga were tested with helium to find outwhether the pipes leaked. The pipes could nothold pressure with no flow. The pressure wasraised to 7 inches water column, and the flowrate was measured to be about 4 cubic feet perhour. Testing the barholes for helium identifieda helium release point in front of the Sbarrorestaurant near the northeast corner of CameliaSoto and Arzuaga. Excavation in front of Sbarrorevealed a damaged and leaking inactive serviceline to the restaurant; the service line leaked at arate of 2.06 cubic feet per hour, and the maineast of that point leaked at a rate of 2.83 cubicfeet per hour. (See figure 7.) The main to thewest had a leak rate of less than 0.1 cubic footper hour.

Sbarro Restaurant Propane Fuel Lines.--Sbarro Restaurant used propane gas fromcylinders stored outside the building’s east wall.The propane flowed into an underground fuelline and then into the building. While the linewas under test pressure, the outside exposedportion was checked for leakage using asoap/water solution. The line leaked at theabove-ground shut-off valve. The valve waslubricated, and a subsequent test showed no lossof pressure. Those tests indicated no leaksunderground.

Smoke Migration Tests.-- On November 30,investigators tried to find out whether therewere any direct, underground paths beneathCamelia Soto from the area of the crackedplastic pipe into the HV building that mighthave survived the explosion. The hole that hadbeen excavated to remove the cracked plasticpipe was covered, and a smoke generator and ablower were used to introduce smoke underpressure into the adjacent soil. Observersstationed around the destroyed buildings saw nosmoke exiting buildings or other structures.

On December 1, a second hole, just west ofthe southwest corner of the HV building, wasused in smoke migration tests. Similarprocedures as described above were employed,

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Figure 5. Location of Crack in Plastic Gas Line to Chicken Kingdom.

Figure 6. Plastic Gas Line Entering Telephone Conduit Bundle in Concrete under CameliaSoto. (Arrows point to the concrete walls on each side of the excavation.)

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and again no observer saw smoke exitingbuildings or other structures.

Examination of Debris and RetrievedDamaged Materials.-- The day after theexplosion, a team from the ATF examined thebuilding and its debris for evidence ofexplosives. Samples of debris (concrete, plaster,and a paint can) were sent to the ATF’s ForensicScience Laboratory, where they were examined

for “any and all explosive residue.” The ATFalso examined the building, using dogs trainedto find explosives. The ATF did not find anyevidence of explosives. Based on those tests, theuse of dogs to detect any explosives in thedebris, and the physical evidence examined inthe HV building, the ATF team determined thatno explosives were used and that damage to theHV building was the result of a fuel-basedexplosion.

Figure 7. Location of Gas Leak from Inactive Gas Service Line under Arzuaga.

In January 1997, Safety Board staffdocumented the damage inflicted on the HVbuilding and recorded the directions of forces,the damages to structural components, and thelocations where heat had apparently had aneffect. (See figure 8.) There was no evidence offire in the building, and the failure direction ofthe building’s columns was consistent with thatresulting from overpressure. The buildingcolumn and connected beams nearest the eastwall just west of the east stairway, column D-1,(see appendix E) was the area identified as mostaffected by heat. Blackened web-like residuewas on the north and west faces of the basementcolumn and on some faces of the north and

connected west beams between the basementand the first floor.

An air conditioner exchange unit that was inthe building when Humberto Vidal bought thebuilding had been mounted on the west face ofcolumn D-1 before the explosion. The unit hadbeen mounted 20 inches above the floor, and theelectric fan motor was about 41 inches abovethe floor. The thermostat was mounted on arectangular piece of plywood on the south faceof this column. The exchange unit was torn fromits mounts by the explosion, and its thermostatand control wiring showed effects of heatdamage. The plywood surface was

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Figure 8. Major Crack in West Wall of Basement of HV Building.

scorched, and the thermostat plastic base platewas deformed.

Also collected were small pieces ofcardboard and insulation material taken from thesouthwest juncture of column C-1, north of D-1,where the first-floor concrete slab once hadjoined the connecting beams. Both itemsexhibited slight surface scorching. Additionally,the west half of the surface underneath thebasement beam between columns E-1 and E-2was noted as having numerous black patternstypical of shoe soles that were stored in thebasement. (See figure 9.)

In February 1997, while building debris anddamaged merchandise were being removed fromthe basement, various synthetic and woodproducts items that exhibited heat exposuredamage were removed for further examination.The items included polyethylene shrink-wrap,fiberglass, vinyl, nylon stockings, paper,cardboard, and plywood. The most severe heatdamage to the synthetic materials indicatedexposure to a temperature sufficient to meltsome portions of them. The highest melt

temperature for the synthetics that weredamaged is approximately 220° F. According towitness observations, the paper, cardboard, andfiberglass recovered from the debris probablywere damaged in fires accidentally set duringthe rescue and demolition operations. Visualexamination of the heat-affected synthetic itemsremoved from the basement showed that theheat had been high enough to melt smallportions of the items but not to ignite them.

Laboratory Examination of Failed Pipes.--The damaged 1 ¼ inch diameter plastic pipesection from Camelia Soto was examined underSafety Board supervision at the Washington GasMaterials Testing Laboratory and at the SafetyBoard’s laboratory. The exterior surface of thesection had a ¼-inch long circumferential crackat the interface of a fused socket coupling.Portions of the socket-to-pipe fusion joint didnot contain the melt roll-out plastic bead thatplastic-pipe manufacturers recommend as avisual indication of a quality fusion joint. It wasdetermined that the crack, which went throughthe wall of the pipe, had started on the outsideof the pipe and slowly progressed inward. The

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slow growth of the crack was the result ofexcessive bending stress. (See figure 10.)

The wall of the 1 ¼ inch diameter steelservice pipe removed from Arzuaga had twoholes; the holes were caused by corrosion. Thepipe had a lateral deflection with an indentationtypical of one caused by excavation activities,

and the part of the pipe that had been damagedby excavation was corroded.

Oversight and RegulationEnron.-- Several times Enron sent consult-

ants to examine the SJGC and report on its con-dition. Brief summaries of some of the reportsfollow.

Figure 9. Shoe Sole Imprints on Bottom of Beam in Basement of HV Building.

Before deciding to buy the SJGC, Enronsent a consultant to evaluate the system and thecompany’s compliance with the DOT pipelinesafety requirements. The consultant’s reportdiscussed the PSC’s special concerns about gasvolume accountability and system corrosionprotection and the DOT’s concerns aboutcorrosion and general system operations. Thereport also addressed concerns about thecorrosion protection system, gas volumeaccountability, metering accuracy, regulatorycompliance, system safety, and the adequacy ofsystem pressure control. Among theimprovements the consultant recommended toEnron were:

1. Eliminate casing and underground electricalshorts to improve its corrosion protection;

2. Insert plastic pipe into old, leaking, andcorroded pipelines;

3. Abandon all unused service lines that arestill under gas pressure to lessen the chancesof electrical shorts to the corrosionprotection system;

4. Give all employees the training on the basicfundamentals and corrosion protection thatwas earlier given to system management;

5. Develop closer communication with otherburied-facility operators to assist inprotecting buried facilities; and

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6. In coordination with other buried-facilityoperators, establish a one-call excavationnotification system.

During the week of March 11, 1985, thesame consultant and the SJGC representativesinspected maps, records, and buried piping toassess the system’s corrosion protection needs,and the consultant developed a master corrosionprotection plan. In June 1985, he did a corrosion

protection survey, developed a corrosionprotection video training program, developedrecommendations on re-testing protected systemsegments, and again recommended using plasticpipe to replace steel pipe where the steel wasexcessively corroded. He also noted that acorrosion control map should be prepared toshow the locations of corrosion test stations,insulated fittings, corrosion protected areas,anodes, and other pertinent information.

Figure 10. Crack in 1 ¼ Inch Plastic Gas Service Pipe to Chicken Kingdom.

In 1986, Enron contracted with Interameri-can Technical Services to perform a safety auditof the SJGC system and operations. Thecontractor reported that the audit had notuncovered any major safety problems. Therepresentative wrote that all of the work thenunderway was a step toward complying withDOT regulations and that the SJGC should havemade real progress by the end of the year. Thecontractor concluded the report by pointing outthat the general corporate knowledge of theexperienced workers was being lost by attritionand that little knowledge was being recorded for

future use. The contractor noted that the lack oftraining manuals, emergency procedures, anddrawings might prove to be a problem in thefuture. The report included the followingcomments and recommendations:

All activities should be documented soas to support the training of others.

The operations manual is too general tobe effective, as it does not provide thenecessary details, such as who is to takean action, with what frequency, in what

31

manner, etc. Greater specificity isneeded to guide employees as to when asafety action should be taken, how totake the action, and under whatcircumstances the action should betaken. [He summarized his assessmentstating that the existing operationmanual is acceptable, but only ingeneral terms.] To make the manualuseful, it needs to be complete throughreferences to other books, industrymanuals, written job descriptions,company organizational charts, andother documents.

It is difficult for a supervisor to beresponsible for the safety actions ofothers if neither has received completetraining that includes a detaileddescription of the job to be done.

The company cannot expect a worker todo a job safely unless there is a standardto follow that includes the use of propertools and protection equipment. Step-by-step procedures need to be specifiedin writing and used as a training tool;otherwise the trainee cannot beconsidered properly trained.

There were no records of accidentinvestigations for the previous fewyears. [He theorized that accidents hadoccurred, but no records were beingmaintained.]

Protection of anode leads during backfill operations.

Improved compaction of sand beddingused to protect plastic pipe installations.

Improved procedures on heat fusingplastic pipe joints.

Protection of plastic pipe from damageduring insertion.

Job site protection to warn traffic whenwork is being performed and to warnagainst smoking near job sites.

On-the-job training by supervisors orfellow workers is not the safest nor most

proper way to train personnel. Suchtraining methods often will result insome essential procedures not beingrelated during training.

There needs to be an emergency plan asrequired by DOT.

There needs to be a program foreducating the public on the hazards ofpropane gas when released and on whatactions should be taken for safety.

Using a flame ionization leak detector,survey the business districts, highpressure pipelines and, by the end of1986, survey all residential areas.

According to Enron, in September 1995, thepresident of Enron Liquid Services began toevaluate the SJGC and other Latin Americaoperations. In October 1995, he visited PuertoRico, where he reviewed the SJGC’s operationsand met with its general manager (his vicepresident of operations). Afterwards, Enrondecided to have a lawyer and an experiencedoutside consultant evaluate the SJGC’scompliance with regulations. Enron also decidedto have an outside consultant assist with a gasleak survey and leak repairs. Enron selectedGillispie Ventures, Inc., (Gillispie) as its outsideconsultant and Heath as its leak surveyconsultant. According to Enron, the constructionengineering manager of the Enron Engineering& Construction Company was called on to assistthe SJGC with the project.

Around November 1995, in an undated note,Gillispie told Enron that approximately 40percent of the service lines were inactive andthat the inactive lines might be the reason for asignificant amount of the unaccounted for gas.Gillispie suggested that reviewing odorizationrecords, inspection and maintenance plans, andincident reports might be useful in “finding” theunaccounted for gas.

In a November 29, 1995, facsimile, Gillispiecontacted the construction engineering managerto discuss a proposed unaccounted-for-gascontrol program. The proposal described athree-phase program: (1) a search-and-verifyphase consisting of an above-ground electronicleak survey to confirm that there were leaks, (2)

32

a leak-pinpointing phase to locate the leaks andclassify them according to severity and repairpriority, and (3) a repair-leaks phase, whichwould provide an opportunity to assess thecondition of the pipeline system.

In November 1995, Enron also contractedwith Heath to help with a leak survey, withdetermining the location of leaks, and withrepairing the leaks. Heath was also retained totrain the SJGC employees to perform leaksurvey work.

Gillispie prepared a report, dated December27, 1995, on the SJGC’s compliance withregulations. Enron refused to give a copy to theSafety Board, claiming that the information wasprivileged.

Enron International’s manager of environ-mental safety, who was responsible for safetyand health matters in six affiliated Enron com-panies, including the SJGC, audited the safetyof the SJGC’s operations shortly before theaccident. Enron contended that the audit wasdone at the request of an Enron attorney, thusalso privileged; Enron refused to provide acopy. At the June 1997 Safety Board Public In-quiry, an OPS representative was asked whetherthe OPS expected pipeline operators to performsafety audits as a normal operating function. Hereplied that operators are expected to conductsafety audits, and that it is not usual for an op-erator to claim privilege for such work.

PSC.--The PSC was established to regulatepublic service companies, such as the SJGC. Itsprocedures were established in the Puerto RicoPublic Service Act of June 28, 1962, asamended, and in the Commonwealth of PuertoRico Uniform Administrative Procedures Act ofAugust 12, 1988, as amended,. Under those acts,the PSC can seek administrative remedies in theenforcement of the pipeline safety requirements.To enforce compliance with its pipeline safetyregulations, the PSC may chose to:

1. Perform a follow-up inspection;

2. Issue an Order to Show Cause as to why thecompany should not be penalized forviolations;

3. File in the Court of First Instance of PuertoRico a special procedure seeking profes-sional relief when life, health, safety, orpublic welfare needs to be protected.

In 1974, the PSC adopted 49 CFR 192 as thepipeline safety requirements in Puerto Rico. TheOPS designated the PSC as the agency in PuertoRico responsible for the pipeline safetyprogram. The PSC certified to the OPS that itwould monitor gas company operations throughcomprehensive daily on-site examinations orevaluations.

Comprehensive inspections consisted of on-site examinations of the SJGC’s plans,procedures, programs, records, physical plant,and work in progress. Comprehensiveinspections were done throughout the year, andthe results were combined in an annualinspection report. An SJGC representativeaccompanied the PSC inspector during allinspections and could record the findings for theSJGC management. The PSC did specializedinspections as necessary to ensure that identifiedproblems were corrected; to investigate failures;and to evaluate the adequacy of designs,operator training, facility tests, and constructionactivity.

The PSC’s certification to the OPS notedthat it would continue revising the gas com-pany’s documents about its inspection andmaintenance, operating and maintenance,emergency plan, and damage prevention pro-grams. The certification also noted that the PSCperiodically inspected the operator’s mainte-nance records about leak surveys, leak repairs,valve maintenance, pressure-limiting and regu-lating stations, telemetering and recordinggauges, relief device tests, odorization, and cor-rosion control.

PSC Inspections of SJGC.-- The PSC’s recordsof its inspections of the SJGC in 1992 through1996 identified numerous probable violations.The 1992 inspection uncovered 16 probableviolations; and at least 5 of the 16 were noted in1993. Probable violation subjects included: (Seeappendix B.)

1. Records on telephonic leak notifications;

2. Records on written leak reports;

33

3. Welding procedures and welder qualifica-tion tests;

4. Inspection of welds;

5. Qualifying plastic pipe joining proceduresand persons who join plastic pipe;

6. Inspection of gas main construction;

7. Testing of cathodically protected systems;

8. Records on required gas line leak andstrength tests;

9. Performance of leak survey; and

10. Records on leak tests of reactivated gasservice lines.

In early 1992, the PSC inspector who wasthe SJGC’s safety manager at the time of theaccident audited the SJGC and noted 16deficiencies. He told the SJGC general managerin writing that the SJGC had not scheduled orexecuted during the last year the cathodicprotection required by 49 CFR 192.465 and thatthe SJGC had not monitored the distributionsystem valves as required by 49 CFR 192.747.He said the SJGC was probably in violation ofthe requirement that the adequacy of corrosionprotection be tested. The inspector also told thegeneral manager that gas system valves had tobe checked and serviced each year and that theinterval between servicing was not to exceed 15months.

1992 Probable Violations

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On April 16, 1993, the SJGC’s safetymanager reported to the PSC on the progressmade in correcting the probable violations thathe had cited in 1992 while he was a PSCinspector. After reporting the SJGC’s positionon the noted sections, he said that the SJGC had

repeatedly stated its position of compliance withthe regulations; and he thanked the PSC formaking the SJGC aware of a fewmisconceptions.

34

On January 27, 1994, the PSC’s directorwrote to an attorney in the Puerto Rico Office ofPublic Interest (the office that initiates legalaction), advising that the September 15, 1993,inspection of the SJGC had identified threedeficiencies in the area of maintenance:

1. Lack of records of leak survey tests duringthe year.

2. Lack of records to show that appropriatepressure tests had been done on plastic pipebefore the pipe was placed in service.

3. Lack of records about corrosion control.

He wrote that two OPS Southern Region Officeinspectors had been present during theinspection and that he was submitting theinformation so that action could be taken tocause compliance.

In a February 24, 1994, letter, the SJGCsafety manager responded to the PSC with thefollowing statements: The CFR did not refer tothe use of any detection equipment. The SJGChad done leak surveys, and the results would beavailable to the PSC. Every plastic pipe that theSJGC had used complied with requirements.The physical condition of each pipe waschecked before it was stored and checked againbefore it was installed. The SJGC had alwaysmaintained records about its external corrosioncontrol system, and the records had beenavailable to the PSC upon request.

The SJGC was fined $500 on August 31,1994, for its failure to comply with safetyrequirements.

The PSC and OPS representatives testifiedat the Safety Board’s June 1997 Public Inquirythat the PSC had inspected the SJGC in 1994,but that records of the inspection could not belocated. In 1995 and 1996, PSC reports showed,respectively, more than 80 and more than 50probable violations. More than 30 of theprobable violations listed on the 1995 reportwere listed on the 1996 report, and more than 20of the probable violations on the 1995 and 1996reports were on or related to probable violationsthat were on the 1992 and 1993 reports. (Seeappendix B.) The probable violations listed onboth the 1995 and 1996 reports had to do withthe following subjects: inspection of plastic pipeinstallations; protection against corrosion;monitoring of corrosion control systems;maintenance of required operating records;written operations and maintenance procedures;emergency procedures; investigation of failures;patrolling of gas system; abandonment of gasfacilities; and protection of cast-iron pipe.

The PSC inspector testified that he couldnot understand why he was unable to explain tothe SJGC’s management what the SJGC had todo in order to comply with the regulations. Hecommented that while the SJGC’s employeesneeded extensive training in many areas of thepipeline safety requirements, Enron hadcompetent personnel who could help the SJGC.

PSC Annual Program Certification. --The PSCreported the following information about theSJGC to the OPS in its annual 5(a) Certification.

PSC Annual Program Certification Summary

CertificationYear

No. of IncidentsReported

No. of ProbableViolations

Found

No. of ProbableViolationsCorrected

No. ofCompliance

Actions Taken

No. of CivilPenalties orAssessments

1994 0 3 4 0 01995 0 2 2 0 2/5001996 0 2 2 0 01997 3 69 0 0 0

35

OPS.--In Puerto Rico, the PSC has theprimary jurisdiction over the SJGC pipelinesystem, while other pipeline operations, such asthe intrastate liquid lines, are subject to OPSjurisdiction. The pipeline safety regulationsapplicable to systems in Puerto Rico are theFederal pipeline safety regulations since thePSC has adopted them.

States participate with the OPS inadministering pipeline safety programs in one oftwo ways. A State may certify to the OPS thatits pipeline safety and enforcement provisionscomply with or exceed Federal minimums, thatit inspects specific pipeline operations in theState, and that it enforces its requirements. TheOPS then views the State as having the primaryresponsibility for pipeline safety, and the OPSmonitors the State’s activities annually.

The second manner in which the OPS and aState can cooperate is for the State to enter intoan agreement with the OPS under which theState inspects gas operations and the OPSenforces the correction of the deficiencies theState identifies. Except for Hawaii, Alaska,Idaho, and Maine, all States, as well as PuertoRico, and Washington, D.C., participate in theFederal pipeline safety program. About 95percent of the pipelines in the United States areunder the oversight of State pipeline safetyprograms.

The Safety Board gathered from the OPSand the PSC their records and correspondencerelated to the PSC’s compliance monitoring ofthe SJGC. The activities were traced back to1983 and show that an OPS representativevisited Puerto Rico each year. During the OPSoversight reviews, its representative reviewedthe PSC operations and performed some on-sitereviews of the SJGC’s facilities and operations.(See appendix C). In the early 1980s, the OPStold the PSC it was concerned that the SJGChad a variety of problems: its gas leak repairactivities; the adequacy of its operations,maintenance, and emergency plans; the lack ofan excavation-damage prevention program; theadequacy of its pressure regulation andoverpressure protection; its corrosion control;and its treatment of discontinued service lines.The OPS also told the PSC that the PSC neededto do a better job of training its inspector, ofdocumenting inspection results and keeping

records, and of developing administrativeprocedures for processing cases of non-compliance. In correspondence, the OPSrecognized that the PSC had improved itsinspector training, that the SJGC’s compliancewith safety regulations was better, and that thePSC’s pipeline safety program performance wassignificantly improved.

OPS correspondence during the 1990s con-tinued to note deficiencies, both in the SJGC’soperations and in the PSC’s pipeline safety pro-gram. The SJGC activities noted as being defi-cient from 1990 to 1993 involved corrosioncontrol, excavation-damage prevention, leakagesurveys, testing of pipe before being placed inservice, installing plastic pipe, replacing cast-iron pipe, and testing employees for drugs andalcohol. In 1993, the OPS recommended that thePSC assess a civil penalty14 against the SJGC fornot surveying leaks in all principal businessdistricts as required. The OPS told the PSC toimprove its documentation of inspections, pro-mote the development of an excavation-damageprevention program, and monitor the SJGC toensure that it complied with its written proce-dures on installing plastic pipe.

In 1994, the OPS advised the PSC that itneeded to make major improvements to complywith pipeline safety requirements. In 1995, afterthe PSC documented over 80 probableviolations in the SJGC’s operations, the OPSadvised the PSC that it needed to promote thedevelopment of a damage prevention programand that the PSC needed a vehicle permanentlyassigned to the pipeline staff, but it made norecommendations for obtaining compliance withpipeline safety requirements.

In 1996, the OPS arranged for 12 represen-tatives of Puerto Rico government agencies,including the PSC, to tour two one-call excava-tion notification systems to learn about imple-menting excavation-damage prevention pro-grams.

In February 1997, the OPS told the PSC thatin 1996 its program was “generally complyingwith the pipeline safety requirements” and that a

14The PSC imposed a $500 fine in 1994 on the SJGC for notsurveying leaks.

36

vehicle needed to be assigned to the pipelinesafety program to allow quicker response topipeline emergencies and to allow the staff towork more efficiently.

The OPS began rating State pipeline safetyprograms in 1989 to reflect its evaluation ofState pipeline programs. Each program aspect,such as adequacy of inspections or complianceenforcement, was assigned a maximum numberof points that the evaluator could award basedon his findings. The State program rating wasdetermined by dividing the total points awardedby the total possible points and then expressedas a percentage. The PSC program ratings fromthe OPS regional office were 96 for 1989, 92 for1990, 91 for 1991, 87 for 1992, 84.2 for 1993,95 for 1994, 97 for 1995, and 97 for 1996.

Other InformationHumberto Vidal. --Humberto Vidal is a

retail merchandise company that sells shoes,socks, handbags, and related items. Thecompany owns more than 30 stores in PuertoRico, and its headquarters were on the upperfloors of the HV building.

Emergency-Response Procedures.-- The HVvice president stated that the store manager hadthe authority to evacuate the building. He saidthat he believed that the manager had beenaware of his authority through verbalcommunications, but that the manager had notreceived any specific training on the issue.Humberto Vidal officials stated that they werenot fully aware of the dangers of gas and thatthey had not received, either by mail or throughthe media, any information from the SJGC orthe local authorities about the dangers of gas.

HV Building .--The HV building had six storiesand a basement. The basement was 12 feet, 11inches, high, 74 feet long, and 53 feet, 10inches, wide. It had a plaster drop ceiling thatwas 16 inches deep. The south end of thebasement was used to store open boxes of shoeson shelves for the shoe store above, and thenorth end was used to store sealed cardboardboxes of shoes for other Humberto Vidal shoestores. After deducting the space occupied bybeams, columns, and stairs, the basementcontained about 50,000 cubic feet of air space.HV officials estimated that about 10,800 cubic

feet of space in the basement was used forstorage at the time of the explosion: 7,200 in thenorth portion and 3,600 cubic feet in the southportion.

A 5-ton air conditioner exchange unit wasmounted on the west face of a column just northof the east stairs, and its thermostat control wasmounted on the south face of the same column.The unit pulled air from the basement floor,cooled the air, and sent it through ducts in theceiling, to be returned to and re-distributedthroughout the basement. The unit reportedlywas used only 2 to 3 hours a day and whenemployees were working in the basement.

The building had a meter room, which wason the first floor at the southwest corner. Thefloor of the meter room was about 2 feet abovethe level of the first floor, and the space betweenthe level of the first floor and the floor of themeter room was filled with gravel. Many pipesand other conduits for electric, telephone, water,and sewer services to the building penetrated thebuilding’s west wall at the meter room. Some ofthe pipes, including one for gas, were fordiscontinued utility services. Pipes and conduitsalso entered the meter room from the gravel-filled space below the floor, and electric linesconduits penetrated the basement wall. The wallseparating the space beneath the meter roomfloor from the rest of the building was made ofconcrete block. Also, there was a joint at eachbasement wall and building column juncture.The basement floor had two small drains intothe soil, one beneath the exchange unit and onein the southeast corner.

Excavation-Damage Prevention.-- Duringthe investigation, representatives of telephone,electric, sewer, water, and gas operationsdiscussed with Safety Board investigators theirmethods of notifying other operators ofunderground facilities before they startedexcavating. They said that the excavationcontractor or utility brigade leader would visitthe gas company and obtain a map showing theburied facilities in the area of the plannedexcavation. The SJGC did not customarily visitthe excavation site, which is necessary if the gascompany intends to mark the locations of buriedgas lines. The SJGC also did not normallyinspect the excavation work as it progressed.

37

During the investigation, there were severalinstances in which maps and records of buriedfacilities were nonexistent, outdated, incom-plete, or not readily available. For instance, thePuerto Rico Aqueduct and Sewer Authoritymap, initially used on scene to locate itsfacilities, did not show the 16-inch diameterhigh-pressure water main under Camelia Soto.The investigators found several other 2- and 4-inch diameter plastic pipes beneath Arzuaga andCamelia Soto and could not find out who ownedthem or what their purposes were.

Puerto Rico does not have a one-call system.(A one-call system allows an excavator to make

one telephone call and know that all companiesthat have underground facilities in the area theexcavator is planning to work on will benotified. The companies that are notified canlocate and mark the location of their facilitiesand take other steps to ensure that the excavatorwill not accidentally damage their facilities inthe process of digging.) The OPS had beensupporting underground-damage preventionlegislation in Puerto Rico for many years, atleast since 1983; and the PSC had worked since1991 to prepare one-call legislation. However,the proposed legislation had not been enacted bythe government of Puerto Rico.

38

ExclusionsThe Safety Board considered two potential

sources for the explosion within the HVbuilding: an explosive device and combustiblegas. The ATF’s on-site and laboratoryexaminations and the Safety Board’sinvestigation found no evidence of an explosivedevice. The ATF’s examination of the HVbuilding debris found the explosion to beconsistent with a fuel-based explosion.

The Safety Board identified three possiblesources of combustible gas that could havefueled the explosion: propane gas from storagetanks, naturally generated gases from the sewersystem or from deteriorating vegetation, andpropane from the SJGC’s propane/airdistribution pipeline system. The Boardexcluded propane from storage tanks becausethe only tanks in the area were at the SbarroRestaurant and pressure tests confirmed theintegrity of the underground portion of the fuelline from the tanks. The Safety Board alsoexcluded naturally occurring gas from the sewersystem or from deteriorating vegetation becauseno damage to the sewer system was reported andbecause such gases would have had an odordistinctly different from the odor of the odorantadded to propane that several witnesses reportedsmelling in the building before the explosion.Therefore, the Safety Board concludes that theexplosion was fueled by propane from theSJGC’s gas distribution pipeline.

The Safety Board also excluded employeefatigue and employee use of drugs or alcohol asfactors that might have contributed to theaccident. The investigation found no evidence insupport of either issue. The work schedules forthe November 21 brigade for the 2 weeks beforethe accident and the interviews with the crewdid not indicate that fatigue was a problem.Three different crews and one technicianseparately made calls at the Río Piedras area.None of the brigade crew worked extensivehours, and although temperatures and humidityin Puerto Rico were comparatively high,crewmembers were adapted to the environment.

The SJGC did not take urine, blood, orbreath specimens from the incident brigade untilabout 8 hours after the explosion. The SJGCdocumented two causes of the delay: injuredemployees needed time for medical treatmentand uninjured employees needed time to helpwith the emergency response. Because of thedelay, the tests for alcohol were not useful. Thebody usually eliminates alcohol at a rate ofabout 0.015 percent to 0.018 percent per hour.15

Thus, after 8 hours, as much as 0.12 percent to0.14 percent can be eliminated from the bloodstream. Without a timely alcohol test, neitherthe SJGC nor the Safety Board could positivelyrule out alcohol as a factor in the accident.

Drugs were not a factor in the accident; theurine samples tested negative for drugs. Urinesamples for the purposes of drug testing are notas time sensitive as blood or breath samples foralcohol testing because the body eliminatesmost drugs much more slowly than it doesalcohol. The Safety Board concludes thatneither employee fatigue nor the use of drugswas a factor in the accident.

In August 1997, the SJGC notified theSafety Board that “in an effort to expedite thepostaccident drug and alcohol testing proce-dures of SJGC, a review of current procedureshad been initiated.” The letter said that theSJGC manager of human resources was respon-sible for the review and that he would also meetwith representatives of the local hospitals to dis-cuss procedures that would allow postaccidentalcohol and drug testing to be more timely.According to the letter, the SJGC’s employeeswould be trained to understand the importanceof drug and alcohol testing and to know whatwas expected of them.

15O’Neill, B.A., Williams, A., and Dubowski, K.,“Variability in Blood Alcohol Concentrations,” Journal of Studieson Alcohol, vol. 44, no. 2 (1983), pp. 222-230.

ANALYSIS

39

The AccidentThis section discusses how propane entered

the HV building and the most likely source ofignition.

Propane Release Points .--Postaccidenttests identified indications of combustible gas inthe subsurface of both Camelia Soto and deDiego, and an analysis of gas samples takenfrom barholes in those streets showed thatpropane was the primary combustible gas.Postaccident testing also revealed that the gassystem in the area of the HV building leaked,and subsequent testing revealed piping failureson Camelia Soto and Arzuaga. On Arzuaga, infront of the Sbarro Restaurant, an inactive gasservice line that had once serviced the restaurantleaked through a corrosion hole caused byexcavation damage. According to flow tests, theline leaked about 2 cubic feet of propane/air anhour. According to postaccident combustible-gas-indicator and helium tests, the releasedpropane traveled only a few feet both east andwest of the corrosion hole and along the path ofthe 2-inch PVC conduit that had been installedabove and in contact with the inactive serviceline.

A compression coupling that connected thegas main and the inactive service line to Com-mercial Ubiñas also leaked. The coupling leakedabout 1 cubic foot of propane/air an hour, andaccording to postaccident combustible-gas-indi-cator tests, most of the propane flowed primarilydownhill, along the west side of Camelia Soto,to de Diego.

The plastic gas line between the Commer-cial Ubiñas service line and the gas meter for theChicken Kingdom was cracked. Postaccidentflow tests using nitrogen established the rate ofrelease as 1.70 cubic feet a minute (102 cubicfeet an hour). The crack was right above a 16-inch-diameter water line that had been installedin 1982 after the plastic service line was. Thecrack was at a plastic coupling that had beenused to join two pieces of plastic pipe.

Migration Paths into HV Basement.--Smoke tests did not reveal a direct path, such asgas flowing through a conduit, that the propanecould have followed into the HV building.However, an analysis of the postaccident

combustible-gas-indicator tests shows thatpropane escaping from this crack floweddownhill beyond the HV building. Themigration probably followed pipes underCamelia Soto and the voids and pipes beneaththe east Camelia Soto sidewalk, at least as far asthe meter room at the southwest corner of theHV building. The propane probably flowedalong one or more of the active and abandonedpipes and conduits that entered the HV buildingbeneath the floor of the meter room. Once underthe meter-room floor, the gas could have flowedinto the basement, following the path ofelectrical conduits into the basement. Thepropane could have also entered the basementthrough joints at columns and wall intersections,which may not have been effectively sealed.Although the investigation was unable todetermine the precise path the propane followedinto the HV building basement, the presence ofthe odor of propane in the basement isconfirmed by several HV employees.

Fueling the Explosion.-- Merchandise andother combustibles in the vicinity of theexchange unit were damaged by heat butshowed no signs of having been touched directlyby flame or fire. Consequently, it is likely thatthe fuel/air mixture in the basement at the timeof ignition was optimum, about 5 to 6 percentgas in air, which would have provided amaximum-force explosion; thus there wouldhave been little flame or soot. Soot is the resultof incomplete combustion. The volume of thebasement was about 35,000 cubic feet,excluding space taken up by beams, columns,storage and shelving, and other solid objects.

Assuming the reported propane/air mix ofthe gas transported in the SJGC’s pipeline (60percent propane gas/40 percent air), the plasticservice line in front of the Chicken Kingdomwas releasing 36.7 cubic feet16 of propane anhour (0.6 times 61.2 cubic feet per hour).Assuming that only the propane released fromthe crack in the plastic pipe entered thebasement, it would have taken about 57 hoursfor enough propane (2,100 cubic feet) to enter to

16The test medium (nitrogen) measured flow was notconverted to an equivalent flow rate for propane as there are manyother uncertainties, such as when the leak first occurred and therate at which propane entered the building, that would have hadmuch greater effects on the calculations.

40

raise the gas-in-air level to 6 percent. It is notlikely that all of the propane released from thecrack entered the basement, but there is noevidence from which the rate of propaneentering the basement can be determined.Furthermore, there is no evidence about howlong propane was escaping before the odor wasfirst detected. Nevertheless, the Safety Boardconcludes that the 7 days between the time theSJGC was first informed of the gas odor and theexplosion was more than enough time for thatleak to have produced enough gas to fuel theexplosion. Therefore, the Safety Boardconcludes that the propane/air being releasedfrom the cracked plastic pipe under CameliaSoto entered the HV basement and was the fuelsource for the explosion.

Location of Explosion in HV Building.- -The explosion cracked the columns of thebuilding and the basement walls about 4 feetbelow the top of the basement walls, indicatingthat the columns were subjected to severebending as the building expanded outward inresponse to the expanding internal pressure. Thefracturing of the concrete floor above thebasement, the destruction of the basement stairsdue to an upward force, and the imprints of shoesoles on the bottom beam face in the basementindicate that the explosion occurred in thebasement. Heat damage to items in the basementindicates that the origin of the explosion was ator near the exchange unit in the basement,which was near the east wall of the building.

The exchange-unit motor was the onlysource of ignition in the area where theexplosion originated. The store manager or theair conditioner maintenance man had probablyoperated the thermostat for the unit about thetime of the explosion. The electric sparkgenerated when the fan motor was activatedwould have been sufficient to have ignited thepropane/air mixture in the basement. Therefore,the Safety Board concludes that the explosionwas initiated in the basement when the exchangeunit was started in preparation for routineinspection and maintenance.

Gas Leak Investigation ProceduresThe SJGC employees who checked for

combustible gas outside the HV building did notfollow the practices included in the leak-survey

materials provided during their training and inindustry guidance because they did not sink thebarholes to at least the depth of the gas lines.The November 15 brigade leader did not probeand test at greater depths, as he should havewhen he obtained a combustible gas reading,and none of the brigade leaders had the barholesprobed to the depth of the gas lines beingsurveyed. The failure of the brigade leaders tofollow standard procedures was critical becausethe gas system was a low-pressure one; thepressure in the area of the HV building wasabout 7 inches water column. Such pressure isnot enough to drive escaping gas upward fromthe point of release. As a heavier-than-air gas,propane released from the pipe system wouldmigrate downhill, flowing through voids alongburied pipes and conduits or flowing throughvoids in the subsurface. Laboratory testsconfirm that propane was present in theunderground at three subsurface locations in thevicinity of the HV building. Tests show also thatthere were high levels of combustible gas in thesubsurface of the de Diego and Camelia Sotointersection, both before and after the explosion.The Safety Board concludes that the SJGCemployees did not detect the undergroundmigration of propane because they did notfollow the procedures that were included in theirtraining and in industry guidance on how tosurvey for leaks in a low-pressure, heavier-than-air gas system.

Had the SJGC employees who tested thesubsurface on November 15 and 20 tested theareas adjacent to the HV building at the depth ofthe gas lines, as was done in the postaccidenttesting, they would have found indications ofcombustible gas along the east side of CameliaSoto, where gas was migrating underground.Further tests would have identified the crack inthe plastic gas service from which the propanewas escaping, and the service could have beenrepaired.

Excavation-Damage PreventionPostaccident testing showed that excavation

work had damaged the pipeline system in threeareas: under Camelia Soto in front of theChicken Kingdom, under the east side ofCamelia Soto at the telephone conduits, andunder Arzuaga in front of the Sbarro Restaurant.

41

The only known event that could account for thedeformation of the plastic service line to theChicken Kingdom was the construction of the16-inch water main in 1992. The main passeddirectly beneath the plastic line, and there wasno sand bedding beneath that segment of theplastic line, as there was beneath other linesegments. The plastic line appeared to havebeen deformed by the backfilling or compactingof soil after it was backfilled over the watermain. Once the plastic line was deformed, itswall was under stress, initiating a slow-growthcrack in the wall of the pipe. The Safety Boardconcludes that the manner in which the waterline was installed imposed excessive stresses onthe plastic gas service pipe, which resulted inthe pipe’s later failure.

The damage to the steel service line onArzuaga, which accelerated the on-goingcorrosion, was initiated when mechanicaldamage, similar to that caused by a backhoebucket while excavating, was inflicted on thepipe. The damage probably occurred when the2-inch PVC conduit of unknown ownership wasinstalled.

The plastic pipe near the telephone conduitshad been cut by a contractor in 1992 while hewas excavating in order to install the conduits.The gas system maps that the SJGC gave thecontractor did not show the plastic pipe, and theSJGC did not mark the location of the pipebefore the contractor excavated. When notifiedof the damage, the SJGC repaired the pipe, butallowed a major portion of the gas service lineto be intermingled with the telephone conduitsthat were being installed and were later encasedin concrete. The SJGC did not disentangle thegas line from the telephone conduits, ignoringits own construction practices and gas industryguidance17 and thus making the gas lineinaccessible for maintenance, leak surveying,and emergency repair.

Accurate maps are an asset for identifyingthe location of buried facilities beforeexcavation; however, during the investigation,investigators found several buried facilities forwhich the maps and related records were

17Gas Piping Technology Committee’s “Guide for GasTransmission and Distribution Piping Systems.”

nonexistent, out of date, or incomplete. ThePuerto Rico Aqueduct and Sewer Authoritymaps did not show the 16-inch-diameter high-pressure water main under Camelia Soto. For 2days, the SJGC was unable to find its drawingsof the plastic gas line under Camelia Soto, andsome records it produced of gas service lines inthe area were not fully descriptive. Additionally,no one was able to locate any records thatshowed the purpose or ownership of the 2-inch-diameter plastic conduit found in contact withthe gas service line under Arzuaga.

Based on the above observations andinvestigators’ discussions with representativesof the telephone, electric, sewer, water, and gasoperations, the Safety Board determined thatexcavators in Puerto Rico do not necessarilynotify operators of underground facilities beforethey excavate. Some excavators may givenotice, but if they do, the action is voluntary anddoes not follow uniform procedures. Forexample, a company or person intending toexcavate near SJGC facilities usually notifiedthe gas company by informally dropping in toget a map of the facilities in the area ofexcavation. The SJGC did not always respondby marking the location of its buried facilities inareas of planned excavation, informing theexcavator about the precautions he shouldobserve, or periodically inspecting theexcavation site. The responses from theoperators of buried facilities made it clear thatmost of them do their own excavating withoutnotifying the operators of other buried facilitiesin the same area. Moreover, the excavation-caused damage to the gas lines under Arzuagaand Camelia Soto indicate that excavators mostoften do not report damage to facility owners;thus, the owners are not aware of the need tomake repairs.

The Safety Board addressed the need for aneffective excavation-damage prevention pro-gram in Puerto Rico in a 1980 Safety Board re-port.18 In the report, the Safety Board identifiedthe need for the government of Puerto Rico tominimize damage to pipelines and other buried

18National Transportation Safety Board Pipeline AccidentReport--The Pipelines of Puerto Rico, Inc., Petroleum ProductsRupture and Fire, Bayamon, Puerto Rico, January 30, 1980(NTSB/PAR-80/06).

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facilities. The Safety Board recommended onJanuary 30, 1980, that the Governor of PuertoRico:

P-80-87:

Direct the appropriate utilities andagencies of Puerto Rico to establish anisland-wide one-call excavation notifi-cation system.

The Safety Board also made safetyrecommendations to The Pipelines of PuertoRico, Inc., the PSC, and the Puerto Rico Tele-phone Company (Safety Recommendations P-80-79, -83, and -88, respectively), calling onthem to cooperate with operators of all buriedfacilities in establishing an island-wide one-call19 excavation notification system. Althoughattempts to initiate the recommended one-callnotification system were made, the attemptswere ultimately unsuccessful, primarily becauseof insufficient cooperation among the variousoperators of buried facilities and because thePSC lacked the authority and resources to spon-sor such a system. Safety Recommendations P-80-79 and -87 were classified “Closed—Unac-ceptable Action” on April 13, 1988. Safety Rec-ommendations P-80-83 and -88 were classified“Closed—No Longer Applicable” on July 25,1988, and May 20, 1984, respectively. Thepipeline company involved in the accident dis-continued operations, and the telephone com-pany, although willing to participate in a one-call notification system, stated that it was notable to undertake the management responsibilityfor such an operation.

The Safety Board reviewed thecorrespondence between the OPS and the PSCabout the need for an excavation-damageprevention program. Since at least 1990, theOPS has been encouraging the PSC to workwith the SJGC and other buried-facilityoperators to establish an excavation-damageprevention program, including a one-callnotification system. The correspondence

19In most States, individuals or organizations are required tonotify a one-call notice center before beginning any excavations.The center disseminates information about the plannedexcavations to buried-facility operators, who then have anopportunity to mark the location of any underground facilities inthe excavation area.

confirmed that the PSC had drafted legislationrequiring excavators to give advance notice ofexcavation to operators of buried facilities, butfurther action had not been taken. The OPS hadperiodically given the PSC information on theexcavation-damage prevention efforts of severalStates and had encouraged the PSC to takesimilar actions. To encourage Puerto Rico toimplement an excavation-damage preventionprogram, the OPS gave the PSC and operators ofburied facilities chances to review Stateprograms. The OPS also provided grants.

On December 16, 1996, as a result of theexplosion in San Juan, the Safety Board issuedthe following safety recommendations to theGovernor of Puerto Rico:

P-96-27

Immediately require that no excavation(except during emergency conditions)be made in areas where buried facilitiesare likely to exist unless the operators ofthose facilities have clearly identifiedand marked the facility locations.

P-96-28

Immediately instruct buried-facilityoperators to review their maps andfacility records to identify errors andomissions, to update their system maps,and to keep their maps up to date.

P-96-29

Immediately require excavators topromptly notify facility operators of anydamage to a buried facility or its supportcaused by excavation operations.

P-96-30

Expedite the implementation of an ex-cavation-damage prevention programthat (1) requires full participation fromall organizations that excavate or thatoperate buried facilities, (2) has an is-land-wide one-call notification centerthat accepts emergency notifications 24hours a day, (3) has effective damage-prevention requirements that include

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government-performed compliancemonitoring and enforcement, (4) incor-porates comprehensive education pro-grams for buried-facility operators, ex-cavators, and the public that explainhow to use the damage prevention pro-gram, and (5) establishes penalties forfailing to use the program properly.

On January 31, 1997, the Puerto Rico Sec-retary of State responded for the Governor,saying that a task force had been established todevelop a plan for implementing the SafetyBoard’s recommendations and that the taskforce had already made progress. On March 7,1997, the Safety Board classified the recom-mendations “Open—Acceptable Response.”The Secretary of State testified at the SafetyBoard’s June 1997 Public Inquiry about the de-velopment of a computerized Graphical Infor-mation System (GIS) for mapping all buriedutilities in Puerto Rico. The mapping systemincludes both government-owned and privatesystems, and system operators are required tokeep the GIS current. On October 8, 1997, theSecretary of State reported that the Governorhad required through Executive Order that allagencies consult the GIS maps before excavat-ing so as to minimize the opportunity of dam-aging underground facilities. The Safety Boardacknowledges the mapping improvements madeby Puerto Rico and classifies Safety Recom-mendation P-96-28 “Closed—Acceptable Act-ion.”

The October 8, 1997, letter from theSecretary of State said that the Governor’sExecutive Order had also established within thePSC an Office for the Coordination ofExcavation Works. The office is responsible fordeveloping procedures on receiving anddisseminating excavation notifications and onidentifying and marking the locations ofgovernment-owned buried facilities in advanceof excavation work. Government agencies mustcomply with the procedures the officeestablishes. Further, the office is to motivateprivate interests to comply with its procedures.The PSC has established a notification center,which began receiving excavator notificationson October 27, 1997. While awaiting the start ofthe notification center, the PSC worked with thegovernment agencies, cable companies, and the

SJGC on coordinating their excavation work soas to minimize the potential of excavation-caused damage.

The October 1997 letter also said thatlegislation has been drafted. If the legislation isenacted, private interests will be brought underthe same excavation-damage preventionprogram as government agencies are under theExecutive Order. The Safety Board expressed itsappreciation of the Governor’s activeparticipation in resolving the safety issuesidentified during the investigation of the RíoPiedras explosion. Safety Recommendations P-96-27, -29, and -30 remain classified “Open—Acceptable Response,” pending implementationof the anticipated island-wide excavation-damage prevention program.

The Safety Board and the DOT agree thatexcavation-caused damage is the major cause ofpipeline accidents. To emphasize the need toimprove State programs, the Safety Board andthe DOT jointly sponsored in 1994 a workshopto define ways of improving excavation-damageprevention nationwide and to define theelements that are essential to an effectiveprogram. The proceedings20 of the workshop,which were provided to all States and to PuertoRico, said that to be effective, an excavation-damage prevention program must:

• Have full participation from all organiza-tions that excavate or that operate buried fa-cilities.

• Have one-call notification centers thataccept emergency notification 24 hours aday.

• Have effective State damage preventionrequirements that include compliancemonitoring and enforcement.

• Have comprehensive education programsfor buried-facility operators, excavators, andthe public that explain how to use thedamage prevention program and thepenalties for improper use or nonuse.

20National Transportation Safety Board, Proceeding of theSeptember 8-9, 1994, Excavation Damage Prevention Workshop(NTSB/RP-95/01).

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The Safety Board encourages the Governorof Puerto Rico to expedite the activities now inprogress so as to implement an effective, island-wide excavation-damage prevention program assoon as possible.

Emergency ResponseFire department personnel in Río Piedras

heard the explosion about 8:30 a.m. andimmediately responded. Police officers whowere on scene at the time of the explosionreacted promptly to help survivors. Additionalpolice officers, rescue workers, and medicalpersonnel arrived on scene within minutes of theexplosion, and Puerto Rico’s emergency planwas quickly and effectively implemented,including the use of the incident-commandmanagement system.

The government of Puerto Rico quicklyrecognized the need for longer-term search andrescue support. The President of the UnitedStates issued an emergency declaration withinhours of the explosion, which made Federaldisaster support funds and resources available toaid continuing search and rescue efforts. Theseveral hours needed to bring search and rescuepersonnel and equipment from Florida did not,in this accident, delay operations, as rescueworkers could not enter the building because itwas not stable. Under other conditions,however, the time needed to bring search andrescue support from remote locations could haveinterfered substantially with saving lives.

Even though the rescue was hampered byrain and the instability of the building, workersdiligently searched through rubble and debrisuntil December 21. They were able to helpsurvivors and find the bodies of the 33 fatalities.The Safety Board concludes that the emergencyresponse was timely and appropriate,considering the instability of the building.

Survival AspectsThe number of casualties was significantly

influenced by the time of day. When theexplosion occurred, Río Piedras had not becomecrowded with shoppers, and employees werejust beginning to arrive for work; most were stillen route or had not yet left their homes.

The location of people influenced theseverity of the injuries they sustained. Of thosewithin buildings, those on the lower floors ofthe HV building were more seriously hurtbecause they fell to lower areas when the floorsthey were on shattered. Employees on thefourth, fifth, and sixth floors had a better chanceof surviving than did people on the first, second,and third floors because the upper floorstructures remained basically intact. Peopleoutside, but in the vicinity of, the HV buildingwere injured or killed because the force of theexplosion either caused people to strike objectsor to be struck by debris.

The SJGC’s written procedures do notrequire dispatchers to gather enough informationfrom callers to evaluate risks. The dispatcherwho spoke with HV employees about the gasodor did not obtain information sufficient tocaution them on actions that should be takenwhile awaiting the arrival of SJGC responsepersonnel. He stated that he routinely gavesafety precautions to callers, advising that theynot use electrical appliances, but that had hebeen told that the odor was strong, he wouldhave considered the situation more serious andwould have suggested more precautions. TheSafety Board believes that callers reporting agas leak should be instructed, as appropriate, onimmediate response actions to take, regardlessof the perceived strength of the odor, so thatthey can evaluate their situation and takeappropriate actions for their safety. Further, theSafety Board does not believe it reasonable for agas system operator to use a caller’s perceptionof the strength of the odor as a basis fordetermining the urgency of the situation. Theability of a person to detect an odor variesaccording to many variables, including hisperception of “strength,” his innate ability todetect odors, the effect of being in anenvironment that may limit his ability to detectodors, the quantity of odorant injected into thegas stream, and the leeching effect of soils onodorants. Consequently, the dispatcher shouldhave asked whether people were experiencingsuch side effects as nausea and whether the odorwas detected in a confined area. The dispatchershould have asked for all the information that heneeded to assess whether the building should beevacuated and whether the help of anemergency-response agency was necessary.

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Despite the dispatcher’s claim that he hadgiven advice, the only surviving HV employeewho had called the SJGC said that the employeeto whom she had spoken gave no advice. Theadministrator of the Chicken Kingdom also saidthat when he called, the dispatcher gave him noadvice. HV employees who talked with the storemanager after he had complained to the SJGCsaid that he had not mentioned receiving anyadvice about safety. Instead, the employees said,the store manager had complained that the SJGCdid not seem to be taking him seriously.

The flyers that the SJGC produced anddistributed did tell readers what to do if theydetected a strong odor of gas. The SJGCdispatchers and other employees who answeredcalls had checklists that listed safety tips andexplained the procedures to follow, includingevacuating buildings. However, the SJGCemployees did not routinely follow theprocedures when they were telling callers theprecautions to take until the site could beinspected.

The Safety Board concludes that the SJGCdispatcher did not gather enough informationfrom the HV employees and consequently couldnot assess the severity of the situation or tell thecallers what they should do immediately. AnSJGC employee cannot give reasonable interimsafety advice unless he gathers basicinformation from each caller. SJGC employeesmust be trained to understand that the callerusually will not be aware of the seriousness ofthe situation or of the precautions that should betaken. The SJGC employees must form the vitalfirst line of defense for callers so that the publicwill not be harmed by the product the SJGCsupplies.

On February 25, 1997, the Safety Boardrecommended that Enron:

P-97-4

Require the SJGC to modify its proce-dures so that an employee who receivesa call about a gas odor collects enoughinformation to be able to assess thedanger, advise the caller appropriately,and determine whether to notify localemergency-response agencies.

Enron’s May 2, 1997, letter responding tothe recommendation said that all employeesresponsible for receiving complaints hadcompleted a refresher course on responding tosuch calls and had completed training on the useof a revised form. At the June 1997 SafetyBoard Public Inquiry, an Enron representativetestified that the checklist had been revised toencourage dispatchers to take more informationfrom callers. The Safety Board reviewed thechecklist and noted that it now includesadditional precautionary recommendations, suchas when to call local authorities and the possibleneed to evacuate the premises. The Safety Boardclassifies Safety Recommendation P-97-4“Closed—Acceptable Response.”

The store manager demonstrated his concernabout the propane odor by complaining to theSJGC and to others. However, he apparently didnot fully understand the enormity of the threatsince he took no action to evacuate the store.His failure to evacuate the store was no doubtinfluenced by the SJGC employees who visitedthe building during the week before theexplosion and repeatedly told him that there wasno gas in the basement.

The HV employees detected the strongergas odors in the basement during the morningsbefore the basement air conditioner had beenturned on. Apparently during the first severaldays, operating the air conditioner reduced theodor to the point that it was no longerdetectable. However, according to witnessstatements, the odor level and the effects of thegas concentration on employees increased overtime to the extent that employees who enteredthe basement became sick. The store managerthen directed that no employee was to enter thebasement.

No SJGC employees entered the basementbefore the air conditioner had been turned on;but the statement of at least one HV employeeindicates that a brigade leader detected the odorwhile he was in the basement. Given that theSJGC employees knew that people in the shoestore had complained of gas odors in thebasement, the SJGC employees should haveerred on the side of safety and evacuated thebuilding until the source of the odor had beenestablished and the conditions proven safe.

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According to the SJGC’s emergency plan, ifa gas leak is confirmed, the building should beevacuated or other actions should be taken. Inthe case of the Río Piedras explosion, more thana week passed before SJGC employeesconfirmed the existence of a significant level ofcombustible gas in the soil; and at the time ofthe explosion, they had not confirmed that theCGI indication was due to propane gas. HVemployees stated to SJGC employees that theodor dissipated when the basement airconditioner was on; yet no SJGC employeetested the basement atmosphere before the airconditioner was turned on. The first SJGCemployee to investigate the complaint was theonly one who had an instrument capable oftesting the basement atmosphere. He did notstart and adjust the instrument when he wasoutside the building to ensure that it would beaccurate inside the building. Starting andadjusting the instrument inside the buildingmeant that it would show only concentrationsgreater than those in the shoe store. SJGCemployees who later entered the basement didnot have instruments capable of detecting gas insuch large areas as the basement and thus reliedonly on their senses of smell to detect thepresence of gas.

SJGC management, because of the repeatedcomplaints and because the SJGC employeesfailed to identify the cause of the odor, shouldhave questioned the appropriateness andthoroughness of the SJGC’s responses andshould have required additional testing of thebasement with appropriate instruments andbefore the basement air conditioner was turnedon. SJGC management should also have madecertain that the HV management was aware ofthe potential danger and of the symptoms peoplemay have when they work in environmentscontaining propane. The gas company’smanagement should have told the HVmanagement about the emergency actions,including evacuation, that should be taken whengas odors continue.

The SJGC’s practice of not decidingwhether a building should be evacuated until agas leak has been confirmed is not appropriate:the decision may be made too late, asdemonstrated by the Río Piedras explosion.SJGC employees need to consider many factors,with the risk to public safety being paramount,

when evaluating the on-site information toassess whether an area should be evacuatedbefore or even during testing. The Safety Boardconcludes that Enron needs to require the SJGCto revise its emergency plan to includeprocedures adequate for protecting public safetyany time a gas leak is suspected, including theneed for building evacuations during leakinvestigations.

Public EducationMost people interviewed after the accident

who had recognized the odor as being that ofpropane indicated that they did not fullyunderstand that the odor was intended to warnthem of danger and that they did not know whatto do to protect themselves, especially when theodor was detected inside a building. The SJGC’spublic education program told people what to doif they smelled gas. A pamphlet explained thatan odorant is used to aid them in detecting gasleaks and told them how to report problems tothe SJGC. However, the program was notsufficient because it did not tell people how toknow when emergency responders should becalled.

The HV managers stated that they were notaware of the substantial threat presented bypropane gas and that the SJGC had not toldthem of the danger. The majority of employeesand residents in the area of the explosioninterviewed after the explosion were not fullyaware of the threat posed by a propane gas leak,and they did not recall receiving informationfrom any source about what to do if theysmelled gas. The HV managers also stated thatthey did not consider evacuating the buildingbecause SJGC employees had not told them ofthe danger. The HV managers believed that theSJGC’s employees would recognize and warnthem of any threats to public or employeesafety, a belief that was reasonable.

Even though the HV building did not havegas service, the occupants should have knownmore about gas emergencies because pipelinesafety regulations required the SJGC to tell thepublic, as well as its customers, how torecognize and respond to the odor of gas. Yetthe SJGC’s customers and non-customers alikewere unaware of the content or existence of theSJGC’s program. Therefore, the Safety Board

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concludes that the SJGC’s public educationprogram did not effectively transmit informationabout the dangers of propane gas and about thesteps to take when gas is detected.

As a result of its investigation into thisaccident, on December 16, 1996, the SafetyBoard recommended that the Governor ofPuerto Rico:

P-96-26

Require information be disseminated toeducate members of the public about thepotential hazards of propane gas andabout actions they should immediatelytake to protect themselves and otherswhen a gas odor is detected.

At the Safety Board’s Public Inquiry, theSecretary of State for Puerto Rico testified aboutthe programs that had been initiated in responseto Safety Recommendation P-96-26, and thePSC also provided information on actions it hadtaken. In an October 8, 1997, letter, theSecretary of State reported on the full array ofactions taken by Puerto Rico. Since the accident,the Puerto Rico government has taken varioussteps to educate the public about recognizingand coping with a gas leak. The government hasacquired and will distribute hundreds ofthousands of education pamphlets. It has trainedpeople in government agencies andmunicipalities to reach and educate suchemergency first-responders as police, bombsquads, fire, civil defense, environmental, andemployee-safety personnel. It has given coursesto school children. The local and regional newsmedia have presented public service messagesand educational articles about detecting andcoping with gas leaks. The Puerto Ricogovernment has made effective use of theavailable media to provide essential safetyinformation to the public, has conferenced withall potentially affected government agencies,and has incorporated on a continuing basis theteaching of safety information into schoolprograms. The Safety Board classifies SafetyRecommendation P-96-26 “Closed—AcceptableAction.”

On February 25, 1997, the Safety Boardrecommended that Enron:

P-97-3

Revise the SJGC’s public educationprogram so that members of the publicunderstand the danger posed by arelease of propane gas, can tell whensuch a release has occurred, and knowwhen steps, such as evacuating the areaor notifying the local emergency-response agencies, are appropriate;incorporate in the program a means ofmeasuring its effectiveness.

In a May 2, 1997, letter, Enron stated that itwas employing a public relations firm todevelop a community outreach campaign toinform the public about the safe use, handling,and management of propane gas, to establish anon-going public education program to keep thecommunity informed about the effortsundertaken by the SJGC, and to measure theeffectiveness of the program. At the June 1997Public Inquiry, an Enron official testified thatthe SJGC would contribute to an island-widepublic education program if all other petroleumgas companies also contributed. On July 2,1997, the Safety Board classified SafetyRecommendation P-97-3 “Open—AcceptableResponse.” On September 30, 1997, Enronadvised the Safety Board that the PSC hadapproved its plan to reduce the SJGC’s pipelinesystem from a 220-mile one to a 20-mile systemthat would serve only commercial customers. Inlight of its significantly smaller gas system, ithad modified its public education program. Itnow mails customers information twice a yearabout the safe use, handling, and management ofpropane gas. Once a year, the company sends itscustomers a telephone rolodex card thatdescribes the steps to take should a gas leak besuspected and a list of emergency telephonenumbers. The company also sends its customersa “Scratch and Sniff” brochure to remind themof the smell of the odorant added to the propanegas. The company sends its customers a flyercontaining safety information in a bullet pointformat. Once a year, the company gives theabove-referenced materials to residential andcommercial locations that are near the pipelinesystem. Finally, the company contributes to anisland-wide public education programcoordinated by the PSC for educating the publicon the safe use of propane.

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According to the May 2 letter, Enron hasalso distributed more than 25,000 “Scratch andSniff” brochures to customers and the generalpublic. The Safety Board notes the aboveimprovements in the SJGC’s educationprogram; however, it is not clear whether Enronwill assess whether the program has reached allpeople who may be exposed to the risks posedby the smaller gas system. The Safety Boardagrees that the island-wide education programcan achieve the results called for by the safetyregulations; however, Enron must monitor theresults of the program to ensure that theobjectives in the regulations are achieved. OnNovember 4, 1997, the Safety Board advisedEnron that Safety Recommendation P-97-3would remain classified “Open—AcceptableResponse” and requested Enron to define theactions it would take to measure theeffectiveness of the island-wide publiceducation program.

After the Río Piedras accident, HumbertoVidal put into writing the procedures it hadverbally given its store managers on preventinginjury and illness for employees and the public.Those procedures provide for:

• Early detection of any hazardous conditionin Humberto Vidal stores.

• Immediate reporting to management ofunsafe conditions.

• Safety and health training to employees,including drills on what to do in case of anemergency.

• Specific evacuation procedures to bedeveloped for each Humberto Vidalbuilding.

The Humberto Vidal management stated ina November 7, 1997, letter that it wasformalizing in these procedures the instructionsverbally conveyed to its managers before theaccident on actions they were to take in theevent of an emergency. Tragically, it opined,even had these written instructions been in placebefore the accident, they would have been oflittle use in preventing an unexpected explosionin a building that did not have gas service, didnot store any hazardous materials, and had been

checked several times by the SJGC and found tobe safe.

The Safety Board has addressed in severalreports about accidents the need for betterpublic education programs, and in a 1990pipeline accident report21 it recommended thatthe Research and Special ProgramsAdministration (RSPA):

P-90-21

Assess existing gas industry programsfor educating the public on the dangersof gas leaks and on reporting gas leaksto determine the appropriateness ofinformation provided, the effectivenessof educational techniques used, andthose techniques used in other publiceducation programs, and based on itsfindings, amend the public educationprovisions of the Federal regulations.

At a 1992 meeting of Safety Board andRSPA staffs, the Safety Board noted that gas-industry public education programs appear toreceive less than half the public recognition thatother public safety programs do, such as thoseabout seat belt restraint and child seat restraints.Safety Board staff urged RSPA to identify thetechniques that make other public educationprograms more effective, determine which ofthe techniques would improve gas-industry pro-grams, and then incorporate them into the Fed-eral requirements. On April 5, 1993, RSPApublished Advisory Bulletin ADB-93-02, whichdirected “gas pipeline facility owners and op-erators to review and assess their continuingeducation programs as applied to customers andthe public.” The Safety Board did not considerthat action responsive and classified SafetyRecommendation P-90-21 “Open—Unaccept-able Action.”

The Safety Board asked RSPA to addressthe status of Safety Recommendation P-90-21 atthe June 1997 Public Inquiry. The director ofthe Enforcement, Compliance and State

21National Transportation Safety Board Pipeline AccidentReport, Kansas Power and Light Company Natural Gas PipelineAccidents, September 16, 1988, to March 29, 1989 (NTSB/PAR-90/03).

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Operations Division of RSPA stated that RSPAhad recently received $800,000 in funding todevelop a national public education format to beused by pipeline operators. RSPA planned towork closely with industry to determine themost effective way to educate the public abouthandling gas. Although RSPA’s past actions onthis issue have not been timely, the Safety Boardis pleased that the OPS now has on its agendathe development of a national public educationformat and encourages the OPS to expeditework on this project. Because of the OPS’srenewed activity, the Safety Board classifiesSafety Recommendation P-90-21 “Open—Acceptable Response.”

Employee TrainingThe inadequacy of the training of the

SJGC’s employees contributed substantially tocausing the explosion. Employees cannot do aproper leak survey or pinpoint a gas leakwithout knowing the lateral location of the gaspipes, the depth of the gas lines, and the depth atwhich the barholes should be made. For low-pressure propane/air systems, it is imperativethat a crew first know the depth of the pipelineand then ensure that the barhole depths reach thepipe depth. The SJGC employees did not knowthe depth of the gas line and did not sink thebarholes deeply enough.

The SJGC’s training was inadequate inother ways. The company did not assess theperformance of its trainees after they had beentrained or document its training. The personnelfiles for the incident crewmembers did includecertificates for various training courses, but thefiles did not indicate the content of the coursesor whether the courses were part of a trainingplan.

Because the SJGC did not have a writtentraining plan, the Safety Board could notdetermine whether its employees had completeda prescribed set of courses for their particularjobs. The certificates in the files did not indicatewhether personnel in certain jobs were all toreceive the same training, as not all individualshad the same certificates in their files. Testscores on some training courses for some peoplewere documented, but not every certificate hadtest scores. Interviews with managementindicated that there had been periodic safety

briefings, but the personnel files did not indicatewhether the brigade members had attended thebriefings. The files did not include periodicreviews of employees’ performance. In all, theSafety Board found that the employee trainingprogram before the accident was poorly andinconsistently documented and that no overalltraining plan had been established.

The Safety Board assessed the development,conduct, and evaluation of training for theSJGC’s employees as inadequate, particularlyfor the people who surveyed, located, andrepaired leaks. The major deficiency was thelack of a front-end analysis of the trainingneeded. A front-end analysis of a job isnecessary in order to identify the tasks22 that theholder of the job must be able to do. Once a taskis identified, it can be converted to a learningobjective,23 or a goal that the trainee willachieve by taking training. Learning objectivescan be used to measure the effectiveness of thetraining. If the trainee, after training, can meetthe learning objectives, that is, successfullyperform the tasks that have been identified asnecessary to do the job, the training has beensuccessful and the trainee is prepared for thejob. Not only does the use of learning objectivesprovide a way of assessing the effectiveness oftraining, it keeps the training focused on thetasks that the trainee actually has to be able todo in order to perform the job. Thus, a goodfront-end analysis of a trainee’s job can saveboth time and money.

The SJGC had the same problems with thetraining for which it had contracted. Thecompany should have, but did not, require thatHeath assess the performance of the employeesit trained. Heath, having had years of experiencein employee training, should have assessed theSJGC trainees to determine the knowledge theyalready had in the areas being proposed fortraining. Had Heath done so, its trainers wouldhave known whether the SJGC employeesneeded advanced training or training on the

22A task is an action or function performed as part of a job.Tasks are usually readily observable and should be measurable fordetermining adequacy of performance.

23A statement describes what knowledge the students willhave or what they will be able to do upon completion of training.

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fundamentals. Doing a job analysis24 would haveidentified the individual tasks related to the job,the number of people needed to perform the job,the tools and equipment necessary forperforming the work, and any manuals,references, regulations, or company proceduresthe trainees were required to follow.

Heath should have performed a front-endanalysis. The analysis is typically accomplishedusing occupational surveys and in-depthinterviews of experienced subject-matter expertsand management personnel. After fullydescribing the learning objectives, the coursedesigner determines the appropriate coursepresentation options. Options can includecomputer-based training, on-the-job training,interactive video, slides, and other media, aswell as the standard platform or lecture format.During this design phase, written testing and/orways to assess student performance can bedesigned to reflect the agreed upon learningobjectives. In this way, assurance is providedthat all critical job tasks are identified and canbe taught and tested.

Assessing Effectiveness of Training onBarhole Depth.-- When an employee fails toperform a particular procedure or task correctly,it is usually an indication the he has not beentrained or that the training was deficient. Poorperformance can also be the result of humanerror. In this accident, the crews were notfollowing the correct leak detection procedure,which called for making barholes to the depth ofthe pipeline.25 The depth of the main line underde Diego was generally 2 to 3 feet, and someparts of it were deeper. The depth of the gas lineunder Camelia Soto varied from 1 1/2 feet to 3feet. The brigade leaders indicated that thebarholes they made around the HV buildingwere about 18 inches deep. The November 15brigade leader and members stated that the holesthey dug were “18, 20, [and] 19 inches andsometimes deeper.” Although one brigade leader

24Job Analysis: The basic method used to obtain a detailedlisting of duties, tasks, and elements necessary to perform a clearlydefined, specific job, involving observations of workers andconversations with those who know the job, in order to describe indetail the work involved, including conditions and standards.

25Appendix G-192-11A “Gas Leakage Control Guidelines forPetroleum Gas Systems,” GPTC Guide for Gas Transmission andDistribution Systems.

stated in January 1997 that his crew probedbarholes 2 feet and deeper and that the gas mainwas about 2 feet deep, days after the explosionhe told a Safety Board investigator that thebarholes were 18 inches deep. Additionally, thebrigade leader who tested for gas in the barholesthe following day stated that they, like the oneshis crew made, were about 18 inches deep.

The concept that 18 inches is the properdepth for a barhole appears to be informationthat had been internalized by the work crews,but the Safety Board was unable to determinethe source. A reference (the earliest found) tobarhole depth is included in Heath’s November1995 work proposal to the SJGC:

Barholes are a minimum of 18 inchesdeep, except when the main is less than18 inches deep, but may need to be tothe depth of the pipe depending on thesoil type and condition as well as thecondition of the pipe, the operatingpressure and the instrument being used.

The brigade workers would not have seen acopy of this proposal, and Heath’s trainingmaterials26 called for the barholes to be at orbelow the depth of the gas main. The materialsdo not direct an 18-inch barhole depth. A Heathconsultant maintains that he taught the crews topenetrate to the depth of the pipe. He also statedthat SJGC employees showed little interest inperforming leak surveys.

After the accident, the SJGC generalmanager and Enron’s operations manager askedHeath to hold training in December 1996 fordesignated employees on surveying andpinpointing gas leaks. Heath trained SJGCemployees in investigating odor complaints,surveying for gas leaks, pinpointing gas leaks,and using the SJGC’s newly acquired GMI GasSurveyor 434. After each course, Heath gave thetrainees a written examination, which consisted

26A copy of Appendix G-192-11A, “Gas Leakage ControlGuidelines for Petroleum Gas Systems,” from the 1990-9 GPTCGuide for Gas Transmission and Distribution System wasprovided as part of the training materials.

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of multiple-choice and fill-in questions, andawarded certificates to those who passed.

However, in January 1997, when SafetyBoard investigators interviewed SJGCemployees, the brigade leaders still did notknow that barholes should be dug to the depth ofthe pipe. On February 25, 1997, the SafetyBoard recommended that Enron:

P-97-1

Immediately retrain all SJGC employeeswho perform leak detection tasks,instructing them how to determinewhether propane gas has leaked fromthe pipeline system, where and at whatdepth to test the subsurface, and how todefine the likely extent of gas migration;in addition, implement a means ofmeasuring the effectiveness of thetraining provided.

P-97-2

Promptly develop and implement forSJGC employees who perform opera-tional and safety-sensitive responsibili-ties a training program that is based onan evaluation of tasks assigned, so thatit imparts the technical and proceduralinformation needed to correctly performtheir duties, and that incorporates ameans of measuring the effectiveness ofthe training provided.

In its May 2, 1997, response, Enron said thatSJGC employees had had formal classroom andon-the-job instruction on gas-leak detection andrepair. In its July 2, 1997, letter to Enron, theSafety Board classified the recommendations“Open—Acceptable Response.” At the June1997 Public Inquiry, Enron said that it hadrequired the SJGC employees to pass tests onthe training they had taken and that employeeswho failed were retrained and retested. There-fore, Safety Recommendation P-97-1 is classi-fied “Closed--Acceptable Response.”

At the June 1997 Public Inquiry, an Enronofficial testified that the company would sooncomplete a comprehensive training andverification program. Later that month, theSJGC gave the Safety Board a master training

plan, outlining how the company intended todevelop and conduct training. The program is toconsist of four phases:

Phase One: orientation and mandatorysafety and health training,

Phase Two: fundamentals training,

Phase Three: company overview,

Phase Four: job-specific training.

The plan shows that Enron is systematicallydeveloping a program that includes the use offront-end analysis and identifies job-specifictasks, but the plan fails to fully identify job tasksfor some SJGC positions. The plan needs furtherclarification and refinement. The plan showsthat the company intends to evaluate employeeperformance through written tests, field-skillsverification, and periodic review.

Since the explosion, Enron has demon-strated its understanding of the importance ofdeveloping and documenting training for SJGCemployees, as evidenced by the company’s ac-ceptance of and fast response to the SafetyBoard’s emergency recommendations abouttraining. That Enron offers its own employeesskill-based pay and computer-based training alsoshows the company understands the need forproper training development, as the skill-basedpay and computer-based training weredeveloped to help improve employee perform-ance. The skill-based pay program was devel-oped using proper front-end analysis and byinvolving education specialists, instructionaldesign specialists, and subject matter experts.(The program, however, was not available toSJGC workers.) Having computer-based trainingshowed that Enron understood the value ofindividualized training plans. Further, theprograms demonstrate that Enron had theknowledge to build effective employee trainingprograms and, as suggested by its response toSafety Recommendation P-97-2, could haveearlier extended this philosophy to its affiliateorganization, the SJGC.

The Safety Board recognizes that throughEnron’s extensive work the SJGC program hasprogressed rapidly from one having virtually nodocumented employee training and qualifica-

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tions to one that is being systematically plannedand documented. The Safety Board encouragesthe developers of the training program to con-tinue refining their identification of employeetasks, duties, and responsibilities, as such identi-fication is the foundation of the program.Pending completion and implementation of thetraining program, Safety Recommendation P-97-2 has been classified “Open--Acceptable Re-sponse.”

Federal Employee Training Require-ments.-- In a February 18, 1987, report,27 theSafety Board recommended that RSPA:

P-87-2

Amend 49 CFR Parts 192 and 195 torequire that operators of pipelinesdevelop and conduct selection, training,and testing programs to annually qualifyemployees for correctly carrying outeach assigned responsibility which isnecessary for complying with 49 CFRParts 192 or 195 as appropriate.

In March 1987, RSPA published anAdvance Notice of Proposed Rule Making,Pipeline Operator Qualifications (Docket No.PS-94, Notice 1), which said:

This notice, issued in advance of aproposed rule, invites public commenton the need for additional regulations ora certification program regarding thequalification of personnel who design,construct, operate, or maintain gas orhazardous liquid pipelines.

The Board responded in May, saying that ithad issued 110 recommendations about thetraining of pipeline workers. The Board hadissued the recommendations as the result ofvarious pipeline accidents between 1975 and1986, and the recommendations covered a widevariety of training deficiencies that applied to abroad segment of pipeline activities. The SafetyBoard advised that it had found training

27National Transportation Safety Board Pipeline AccidentReport, Texas Eastern Gas Pipeline Company Ruptures and Firesat Beaumont, Kentucky on April 27, 1985, and Lancaster,Kentucky, on February 21, 1986 (NTSB/PAR-87/01).

deficiencies that were either contributing ordirectly causal to pipeline accidents in nearlyevery facet of activity investigated, includingoperations, construction, and emergencyresponse. It noted that training and performancecriteria for the pipeline operating communityneeded to be developed and implemented so thatthe effectiveness of the training and theperformance of the operator could be measured.The Board said that without such measures itwould be hard to determine objectively whethertraining had improved an employee’sperformance and whether the objectives of thetraining had been met.

In its comments to the Advance Notice ofProposed Rule Making and directly bearing onthe SJGC investigation, the Safety Board toldRSPA that it needed to require pipelineoperators to:

• Identify each employee whose successfulaccomplishment of assigned responsibilitiesor tasks was a necessary part of anoperator’s actions to comply with theFederal pipeline safety regulations;

• Perform analyses to identify the tasks, jobs,and responsibilities each employee had thatrelated to Federal pipeline safetyregulations;

• Identify specific training methods to beemployed to provide each employee withenough knowledge to effectively carry outapplicable jobs, tasks, and responsibilitiesidentified in the analyses;

• Identify methods to be used in evaluatingthe effectiveness of the training, includingthe identification of standards foracceptance; and

• Document the training provided for eachemployee and training evaluations.

On May 11, 1993, the Safety Boardreminded RSPA that it had been more than 5years since the Board had recommendedestablishing employee qualification standardsand that implementing the recommendationshould have been one of RSPA’s top priorities.The Board affirmed that it remained firmlyconvinced that the recommended training,

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qualification, and testing requirements andstandards were essential. As a result of RSPA’sinaction, Safety Recommendation P-87-2 wasclassified “Open—Unacceptable Response.”

On July 27, 1994, RSPA issued a Notice ofProposed Rulemaking (NPRM) proposing thequalification standards for pipeline employees.On November 9, 1994, the Safety Boardresponded to the NPRM, commenting on theproposal and urging RSPA to expeditecompletion of the rulemaking. RSPA received131 comments on its proposal; and almost 2years later, on June 25, 1996, it withdrew theproposal in favor of conducting a procedureknown as “Negotiated Rulemaking.”28 In itsJune 26, 1996, Notice of Intent, RSPA statedthat “Commenters to the NPRM stated that theproposal was too prescriptive and that manyreferences to training requirements should bemodified to place the focus of the NPRM onactual qualifications, not the methods ofachieving it.” RSPA selected a committee torepresent the “interests” affected by actions thatit may take on employee qualificationrequirements. In April 1997, the committeebegan drafting a new rule proposal, but has notcompleted its task.

The committee has addressed provisions foremployee performance assessment andrecordkeeping. By requiring the evaluation ofemployees’ performance, the committeeaddressed the Safety Board’s concern that thequalifications of employees of pipeline facilitiesbe judged on the basis of objective,demonstrable forms of evaluation. Thecommittee will also recommend that anevaluation of an employee’s performance berequired if the employee is involved in areportable incident to which his actions mayhave contributed. In August 1997, thecommittee had its fourth meeting. The goal was

28 “The negotiated rule process assists in the development ofthe NPRM, allowing all affected parties to present their views toreach a consensus, thus avoiding litigation and disagreement oncethe rule is finalized. By using this process the OPS has agreed topublish the committee’s consensus. Also, the overall contents ofthe regulation are the responsibility of the committee. However, byparticipating in this process, the OPS does not give up itsresponsibility to promulgate the final rule.” Taken from the draftsummary minutes of the April23, 24, 1997, advisory committeemeeting.

to obtain consensus among committee memberson a draft regulation concerning operatorqualifications and to review and revise theoutline for the rulemaking preamble.

If employee qualification requirements areestablished, an operator will be able to accessdocumentation about the training andqualifications of any employee he is consideringhiring. In an era of downsizing and reductions inforce, the industry should benefit from beingable to know about an employee’s training andqualifications. The employees will havecredentials that are accessible. In support of thecurrent employee training and qualificationefforts, a manager of pipeline training29 statedthat having a properly trained workforce addstremendous value to a company by reducing theexpense of maintenance, equipment damage,and personal injuries. Moreover, he added, well-trained employees are usually much moreproductive. Needless to say, the public’s safetywould be significantly enhanced if RSPAensures that the pipeline workforce is qualifiedand trained to carry out its assigned tasks safely.The Safety Board continues to urge RSPA toexpedite the completion of rulemaking action toachieve this essential safety objective.

Pipeline Safety OversightAt the time of the accident, SJGC manage-

ment did not provide a working environmentthat encouraged its employees to adhere to op-erating policies and practices; management didnot adequately train its employees, and man-agement did not oversee the employees enoughto identify and correct unsafe practices. Of thethree top managers, only the operations super-intendent had extensive knowledge of the gassystem, and he had limited managementexperience. That environment created by man-agement contributed significantly to the cause ofthe accident.

Even though the SJGC management failedto prepare and motivate its employees, otherentities had chances to correct the deficienciesbefore the accident. Enron, the PSC, and the

29Gas Industries, U.S. DOT Qualification Ruling, TimothyLilly, Manager of Compliance and Technical Training, CNGTransmission Corporation, January 1997.

54

OPS each had responsibilities for ensuring thatthe operations of the SJGC were conducted sothat public safety was not endangered. TheSafety Board concludes that the accident mighthave been prevented had Enron, the PSC, or theOPS been timely in requiring the gas companyto adequately train its employees in leak surveyprocedures.

Enron .--Enron, as the owner of the SJGC,had the corporate and primary responsibility forensuring that its affiliate company’s operationswere safe. It had the opportunity and capabilityto identify the SJGC’s needs and to makeimprovements, either by using SJGC employeesor by calling on specialized or technicalresources, such as legal, regulatory compliance,and safety, available in corporate groups andaffiliate companies. The SJGC managers did notknow about the older audit findings. They wereheavily dependent on Enron for assistance intechnical and safety matters. However, Enronaffiliate company personnel also did not knowabout the previous studies and audits.

Before buying the SJGC in 1985, Enronmanagement learned of deficiencies in SJGCoperations through a consultant’s audit. Afteracquiring the SJGC, Enron used consultants andEnron affiliate personnel to audit the SJGC’soperations. Enron affiliate management oftenvisited the SJGC and met with the SJGC generalmanager. Because the Enron affiliatemanagement reported to Enron management, thevisits allowed Enron to learn about operatingproblems, including the results of the PSC’sinspections. Consequently, it was possible forEnron management to be aware of the status ofSJGC operations.

The problems that the SJGC had with itsoperations before it was acquired by Enron werenot resolved, as they were repeatedly identifiedin subsequent audits contracted by Enronaffiliates and in PSC letters to the SJGC.Corrosion, employee training, construction, andoperation deficiencies continued to be identifiedas areas requiring improvement. Even so, Enrondid not act expeditiously to ensure effectivecorrections. Toward the end of 1995, Enronbegan to improve the SJGC’s compliance withthe safety requirements. Enron managementbrought in Enron affiliate and contract resourcesto plan and direct the improvement. Enron

wanted to reduce the amount of unaccounted forgas by improving the accuracy of measurementsand by finding and repairing gas leaks. Enronalso wanted to reduce the amount of damagethat excavation was doing to the pipelines.While the improvements were needed, theyconstituted only a small portion of theimprovements necessary to bring the SJGC’soperations into compliance with acceptedindustry standards and with Puerto Rico’s safetyrequirements on employee training, publiceducation, etc.

Since the explosion, Enron has dedicatedconsiderable resources to correcting thedeficiencies at the SJGC. Enron, through SJGCfilings to the PSC, requested that it be allowedto shut down about 200 miles of its 220-miledistribution system. Enron’s request stated thatthe gas system was unable to competeeconomically with other energy optionsavailable in Puerto Rico. The PSC has approvedEnron’s plan. The smaller 20-mile gas systemnetwork will provide service only to itscommercial gas customers; however, thehazards to public safety in the vicinity of thesystem will remain. Enron needs to establish apermanent method of effectively overseeing theSJGC so as to ensure that its actions areconsistent with public safety requirements andpipeline safety regulations.

PSC.--Before 1990, the PSC had only oneinspector, and he had many other responsibili-ties, including overseeing all bottled propaneoperations in Puerto Rico. During that time, theOPS, through its annual audits, appeared to bedoing most of the oversight of the SJGC, and itsrepresentative pointed out several areas thatneeded improving. In the early 1990s, the PSC’soversight of the SJGC improved: the inspectorhad taken extensive training at DOT’s Trans-portation Safety Institute and a second employeewas being trained as an inspector. The PSC didnot have written procedures to guide itsinspectors on documenting probable violations,notifying SJGC management of violations, fol-lowing up violations, and telling the PSC com-missioners when formal action was needed toenforce compliance. Even so, the PSC inspec-tors did identify, document, and formally notifythe SJGC of probable violations. While theSJGC did not totally ignore the notices, its re-sponses indicate that it saw little urgency about

55

making corrections. The PSC’s 1992 and 1993inspections documented 16 and 20 probableviolations, respectively; 5 violations were thesame for both years.

At the OPS’s urging in 1993, the PSC levieda small monetary penalty against the SJGC in1994. In 1995, PSC inspectors documentedmore than 80 probable violations. A PSCinspector testified at the June 1997 PublicInquiry that he had discussed the 1995inspection results with SJGC management;however, the PSC could produce no documentsproving that it had either notified the SJGC ortold the PSC commissioners of any need to takeformal action against the SJGC. The PSC didnot take any formal action against the SJGC forfailing to correct the probable violations; and in1996, PSC inspectors documented almost 60probable violations. More than 30 were thesame as those documented in 1995. Again, thePSC was unable to produce writtendocumentation showing that the SJGC had beennotified; however, a PSC inspector testified thatan SJGC representative accompanied the PSCinspectors on all inspections and was informedabout all probable violations. Therefore, itwould appear that in both 1995 and 1996, SJGCmanagement had the opportunity to learn aboutthe PSC’s findings.

On March 13, 1997, the PSC issued anadministrative order to the SJGC about the 1996inspection. The order noted that the SJGC hadbeen told about the areas of non-compliance onthe day of the inspection and that the problemsincluded corrosion control, operation andmaintenance plans, public education,investigation of failures, maximum operatingpressure, patrolling, required tests beforerestoring gas service, abandoning facilities,deactivating facilities, protecting metal pipe,remedial steps, required notifications, andrevision of records. The order stated that theSJGC was required to eliminate the deficiencies.

The PSC order referred to the Río Piedrasexplosion and the Safety Board’s February 25,1997, recommendation letter to Enron. The PSCadopted the Safety Board’s recommendations aspart of the administrative order. Using the orderof presentation in the Safety Board’s letter, thePSC identified the recommendations as items‘A’ through ‘D.’ Under each item, the PSC

added to, clarified, and emphasized theindividual actions that the SJGC would have totake to fulfill the intent of the recommendations.Within 30 days of the order, the SJGC was tosend the PSC a copy of its plans for complying;thus the PSC could evaluate the SJGC’sprogress.

On April 3, 1997, an attorney for the SJGCasked the PSC to reconsider its administrativeorder on the following grounds: (1) the SJGCobjects to and disputes the contention that itlacks programs, systems, and appropriate meansto reasonably conduct operations; (2) the SJGChad informed the PSC that it had fulfilled andwas ready to comply with assignments when andwhere required; (3) the SJGC is determined tocertify fulfillment of assignment ‘C’ during orbefore April 18, 1997; (4) the SJGC proposes tocoordinate a program comparable to assignment‘D.’ The SJGC stated that it believed the PSCshould consider these alternatives and meet withthe SJGC to reconsider and revise the order. OnApril 30, 1997, after reconsidering, the PSCordered the SJGC to comply with theadministrative order.

The PSC’s most recent inspectionsdemonstrate that it has recognized the need toinspect SJGC operations more thoroughly;however, until the explosion, the PSC did notenforce its safety requirements aggressively.After the explosion, the PSC ordered the SJGCto comply with the Safety Board’srecommendations, but the PSC did nothing tomake the SJGC resolve the probable violationsthe PSC had identified in 1995. On May 27,1996, the SJGC responded to the March 12administrative order about the 1996 inspection.The PSC has not yet determined whether theSJGC has corrected the probable violations orwhether further enforcement action is required.The Safety Board concludes that the lack ofwritten guidance for PSC inspectors ondocumenting probable violations, on formallynotifying the SJGC, on doing timely followupsto determine whether violations have beencorrected, and on telling the PSC commissionerswhen there is a need for formal action to enforcecompliance contributed to poor communicationsamong PSC staff, its commissioners, and SJGCmanagement. The lack of effective programmanagement likely contributed to the ineffectiveuse of PSC enforcement capabilities and may

56

have contributed to the failure of Enron and theSJGC to correct deficiencies. The Safety Boardbelieves that the PSC must develop writtenprocedures to guide its staff’s actions if it is toensure that monitoring will be effective, that theSJGC will be notified of its probable violations,and that the commissioners will take prompt,aggressive enforcement steps if the SJGC failsto make timely corrections in its operations.

OPS Oversight of State Pipeline SafetyProgram .--The OPS is responsible forevaluating the PSC’s pipeline safety program.At the June 1997 Public Inquiry, the OPSsouthern region director, whose responsibilitiesinclude overseeing Puerto Rico, advised that itis essential to the success of a program, as wellas a requirement of the certification, that theagency be able to enforce the regulations bylevying civil penalties as appropriate. He alsosaid that if a State finds violations but does notnotify the operator and follow up to make surethe violations are corrected, the OPS will callthe deficiency to the attention of the PSC.

The region director said that the PSC’sprogram has improved steadily since 1992.“Today, there is more support from the PSCcommissioners for the pipeline safety program,and this is especially true for the past couple ofyears since one commissioner pledged hiscooperation to the OPS and his support for thepipeline safety staff.” Based on his review of thecorrespondence between the PSC and the SJGCabout the probable violations, the regiondirector said, the SJGC needs to improve itstechnical knowledge significantly in order tounderstand the pipeline safety regulations.

The director of OPS’s Safety EnforcementCompliance and State Operations Office statedat the Public Inquiry that the OPS has less than40 inspectors with which to cover the entirecountry. If a State does not certify to performintrastate inspections of gas pipeline operatorsand enforce pipeline safety requirements, theOPS is required to do it. Consequently, the OPSwill work with a State program until the Statealmost turns it back to the OPS. He added thatthat does not mean the OPS will let things go onthat should not. Rather, the OPS works with theState to improve the program to get its support.The OPS does everything it can to keep fromdecertifying a program. He stated that one

reason the OPS works hard to keep the programwith the States is that the OPS believes thatoperator response is better and that a Stateusually has much greater resources than the OPSdoes.

Each year, the OPS evaluates the PSC’sperformance during the previous year. Duringthe 1970s and 1980s, the OPS sent letters to thePSC specifying the deficiencies in SJGCoperations and followed up with the PSC toensure that corrective action had been taken.Based on the OPS’s letters to the PSC in the1990s, the OPS concentrated, almost to theexclusion of all other needs, on obtainingequipment to enable PSC staff to better performits inspections and on establishing anexcavation-damage prevention program forPuerto Rico.

Although the OPS has been trying toimprove the PSC’s pipeline safety program,since 1993, the OPS has given the PSC’spipeline safety program high scores despitesignificant deficiencies. The problem wascompounded by the OPS’s letters to the PSC’spresident; the letters gave no indication theprogram needed significant improvements, suchas the development of a written procedures toguide its staff on documenting and notifying anoperator of probable violations or thedevelopment of an effective enforcementprogram.

The OPS did notify the PSC in 1993 of itsconcern about the PSC’s 1992 inspectionfindings of 16 probable violations, and itadvised the PSC that it should seriouslyconsider using civil penalties to force the SJGCto make corrections. As a result, the PSC didlevy a monetary penalty. Since then however,the OPS has not recommended that the PSC takeany enforcement actions, even after the RíoPiedras explosion. Based on its latest evaluation,the 1996 evaluation, the OPS awarded the PSC arating of 97 for its pipeline safety program,including giving it the highest possible rating forits compliance program. The OPS awarded theseratings even though the PCS in 1996 had toldthe SJGC that it had more than 50 probableviolations, of which more than 30 had beenidentified in 1995, and the PSC had not takenany formal action to force the SJGC to makecorrections.

57

The Safety Board agrees with the OPS thatthe States do provide more resources than theOPS does for monitoring pipeline operationsand that when possible, the responsibility formonitoring should remain with the State.However, the OPS retains overall responsibility;and through its monitoring of State programs, itmust ensure that pipelines are operated in amanner that provides adequate public safety.The Safety Board also agrees that the OPSshould work with the States to help themmaintain and improve their programs. Howeverat no time should the OPS’s objective ofkeeping States in the pipeline safety programtake precedence over its responsibility forensuring that pipeline systems are safelyoperated and maintained to preserve publicsafety.

Each year, after the OPS had evaluated thePSC’s pipeline safety program, it scored theprogram’s effectiveness and gave the PSCpresident a numerical grade. The PSC’senforcement program received the maximumallowable points in each of the 3 years. For thepast 3 years, the PSC’s pipeline safety programreceived overall scores of 95, 97, and 97,respectively. The scores would indicate little, ifany, need for improvement. The Safety Boardconcludes that the OPS’s evaluation scores forthe PSC before the Río Piedras explosion misledthe PSC commissioners about the need to bringenforcement action against the SJGC.

The OPS may have given the PSC programhigh ratings because the questions on the OPS’sevaluation form were poorly designed andbecause the OPS’s evaluators lacked writtenguidance on how to rate various aspects of aState program. The evaluation questions that the

Safety Board reviewed were loosely framed, andthe evaluators’ assessments of the answersseemed to be subjective rather than based onspecific, uniform criteria.

When a State program is not functioning,the OPS must fill the gaps; any time publicsafety is being compromised, the OPS must act.The Safety Board believes that in view of theevents preceding the Río Piedras explosion, theOPS must improve its State pipeline safetycertification program. The OPS must developwritten guidance and criteria that its personnelcan use to evaluate State programs objectively,and the OPS must require States to be prompt incorrecting identified program deficiencies.

The Safety Board concludes that the OPSfailed to effectively monitor Puerto Rico’spipeline safety program. The Safety Board isconcerned that the deficiencies in the PSC’spipeline safety program were allowed to existfor so long without the OPS recognizing themand notifying the PSC commissioners about theneed for corrective actions. The Safety Boardconcludes that the Río Piedras accident mighthave been prevented had the OPS been timely innotifying the PSC commissioners that theineffectiveness of the PSC’s enforcement wasendangering public safety and had it insistedthat the PSC require the SJGC to promptlycorrect all deficiencies. Had the PSC’s oversightbeen effective, the SJGC brigade leaders mighthave been properly trained in detectingsubsurface gas leaks, and thus able to locate andrepair the gas leaks on Camelia Soto before theexplosion. Therefore, the Safety Board believesthat the OPS needs to reassess the effectivenessof its State monitoring program.

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Findings1. Neither employee fatigue nor the use of

drugs was a factor in this accident.

2. The explosion was fuel based; it originatedin the basement of the Humberto Vidalbuilding and was probably initiated whenthe basement air conditioner unit wasoperated.

3. The source of fuel for the explosion was themixture of propane and air that leaked fromthe failed plastic gas service pipe to theChicken Kingdom Restaurant and probablymigrated underground into the meter roomof the Humberto Vidal building and theninto the basement.

4. The 1992 backfilling and compacting of soilover the 16-inch water line imposedexcessive stresses on the plastic gas servicepipe to the Chicken Kingdom Restaurant,stresses that later caused the service pipe tofail.

5. The gas company’s employees were notproperly trained in testing for leaks; they didnot test correctly, and they did not find andrepair the leak.

6. The gas company employee who receivedtelephoned reports of gas odors failed toprovide effective instruction to callers onthe dangers of propane and the steps to taketo protect themselves because neitheremployee training nor supervision wasadequate.

7. The gas company dispatcher who talked tocallers reporting gas odors did not giveadequate advice to callers partly because hedid not gather enough information from thecallers to evaluate the seriousness of thesituation.

8. The gas company’s public educationprogram was not effective in warningpeople who had reported a gas odor aboutthe dangers of propane gas and about thesteps to take when gas is detected.

9. The response from local, Puerto Rico, andFederal emergency responders was timelyand appropriate, given the building’sinstability and the weather. The timerequired for Federal emergency respondersto arrive on scene did not hamper the searchand rescue efforts in this instance.

10. The gas company’s employees were notadequately trained in surveying andpinpointing leaks.

11. The leak detection training given to the gascompany’s employees was inadequate partlybecause neither the company nor HeathConsultants, Inc., identified the tasks forwhich the employees needed to be trained ortested the employees to make sure thetraining had been effective.

12. Enron Corp. did not provide a workingenvironment that encouraged the employeesof the gas company to follow its operatingpolicies and practices strictly, and it did notoversee employees’ actions enough toidentify and correct unsafe practices.

13. Although Enron Corp. had known since1985 that the gas company’s operations didnot comply with pipeline safetyrequirements and recommended industrypractices, it failed to require the gascompany to comply.

14. Enron Corp. had begun before the explosionto correct some deficiencies in the gascompany’s operations, but its attempt wasneither timely nor sufficient.

15. In 1995 and 1996, the Puerto Rico PublicService Commission found numerousprobable violations in the gas company’scompliance with pipeline safetyrequirements, but the Commission did notrequire timely, effective corrections.

16. The Puerto Rico Public ServiceCommission’s inspectors did not havewritten guidance on documenting probableviolations, on formally notifying the gascompany of violations, on doing timelyfollowups to determine whether violations

CONCLUSIONS

59

had been corrected, and on telling thecommissioners when formal action wasneeded to enforce compliance; the lack ofwritten guidance contributed to poorcommunications among the staff andcommissioners of the Puerto Rico PublicService Commission and the management ofthe gas company.

17. The Research and Special Programs Ad-ministration/Office of Pipeline Safety failedto effectively monitor Puerto Rico’s pipe-line safety program.

18. The evaluation scores that the Research andSpecial Programs Administration/Office ofPipeline Safety gave the Puerto Rico PublicService Commission mislead thecommissioners about the adequacy of itspipeline safety program and about the needto take enforcement action against the gascompany.

19. The accident might have been prevented hadthe Research and Special ProgramsAdministration/Office of Pipeline Safetybeen timely in notifying the Puerto RicoPublic Service Commission that theineffectiveness of its enforcement wasendangering public safety and had theResearch and Special ProgramsAdministration/Office of Pipeline Safetyinsisted that the Puerto Rico Public ServiceCommission require the gas company topromptly correct all deficiencies.

20. The accident might have been prevented hadEnron Corp., the Puerto Rico Public ServiceCommission, or the Research and SpecialPrograms Administration/Office of PipelineSafety been timely in requiring the gascompany to adequately train its employeesin leak survey procedures.

Probable CauseThe National Transportation Safety Board

determines that the probable cause of thepropane gas explosion, fueled by an excavation-caused gas leak, in the basement of theHumberto Vidal, Inc., office building was thefailure of San Juan Gas Company, Inc., (1) tooversee its employees’ actions to ensure timelyidentification and correction of unsafeconditions and strict adherence to operatingpractices and (2) to provide adequate training toemployees. Also contributing to the explosionwas (1) the failure of the Research and Special

Programs Administration/Office of PipelineSafety to oversee effectively the pipeline safetyprogram in Puerto Rico, (2) the failure of thePuerto Rico Public Service Commission torequire San Juan Gas Company, Inc., to correctidentified safety deficiencies, and (3) the failureof Enron Corp. to oversee adequately theoperation of San Juan Gas Company, Inc.

Contributing to the loss of life was thefailure of San Juan Gas Company, Inc., toinform adequately citizens and businesses of thedangers of propane gas and the safety steps totake when a gas leak is suspected or detected.

60

As a result of this investigation, theNational Transportation Safety Board makes thefollowing recommendations:

--to the U.S. Secretary of Transportation:

Improve the Department of Transporta-tion’s State pipeline safety evaluationprogram by developing written guidanceand evaluation criteria to assist theResearch and Special Programs Ad-ministration/Office of Pipeline Safetypersonnel in objectively evaluatingState programs and in requiring Statesto promptly correct identified programdeficiencies. (P-97-5)

--to the Research and Special ProgramsAdministration:

Modify your monitoring of Statepipeline safety programs to ensure thatthe States are timely in monitoring thecorrection of identified safetydeficiencies and to ensure that theyimplement enforcement action asnecessary. (P-97-6)

Complete a final rule on employeequalification, training, and testingstandards within one year. Requireoperators to test employees on the safetyprocedures they are expected to followand to demonstrate that they cancorrectly perform the work. (P-97-7)

Require that San Juan Gas Company,Inc., take action necessary to ensure thatabandoned pipelines are properlydisconnected, purged of propane, andadequately secured to prevent thetransmission of flammable vapors andgases, and to ensure that abandonedpipelines are properly identified onmaps. (P-97-8)

--to the Puerto Rico Public Service Commission:

Develop written procedures to guidepipeline inspectors in assessing thecompliance of gas pipeline operatorswith pipeline safety requirements, indocumenting probable violations, innotifying gas pipeline operators ofprobable violations, and inrecommending to the commissionersany formal action that may be requiredto obtain prompt compliance. (P-97-9).

Require that San Juan Gas Company,Inc., take action necessary to ensure thatabandoned pipelines are properlydisconnected, purged of propane, andadequately secured to prevent thetransmission of flammable vapors andgases, and to ensure that abandonedpipelines are properly identified onmaps. (P-97-10)

--to Enron Corp.:

Require San Juan Gas Company, Inc., toinclude procedures in its emergencyplan that its employees can use indetermining whether a building or areashould be evacuated when a gas leak issuspected. (P-97-11).

Require San Juan Gas Company, Inc.,when soliciting a training proposal, torequire that the proposal include plansfor identifying the tasks for which thetrainees must be trained and forassessing the job performance of thetrainees and the effectiveness of thetraining. (P-97-12).

--to Heath Consultants, Inc.:

Identify, when developing contractedtraining, the tasks for which the traineesmust be trained and develop measuresfor assessing the job performance of thetrainees and the effectiveness of thetraining. (P-97-13)

RECOMMENDATIONS

61

BY THE NATIONAL TRANSPORTATION SAFETY BOARD

JAMES E. HALLChairman

ROBERT T. FRANCIS IIVice Chairman

JOHN A. HAMMERSCHMIDTMember

JOHN J. GOGLIAMember

GEORGE W. BLACK, JR.Member

December 23, 1997

For additional information regarding this accident, see NTSB special investigation report Brittle-Like Cracking in Plastic Pipe for Gas Service, NTSB/SIR-98/01.

63

APPENDIX A

Investigation and Hearing

Investigation

The National Transportation SafetyBoard was notified on November 21, 1996, bythe Office of Pipeline Safety’s Southern RegionOffice of an explosion damaging a six-storybuilding in the Rió Piedras shopping district ofSan Juan, Puerto Rico. The Safety Boarddispatched an investigative team fromWashington, D.C., comprising investigativegroups for pipeline operations, survival factors,and human performance.

Hearing and Depositions

The Safety Board conducted a publichearing in conjunction with the investigation onJune 2-5, 1997. A staff-conducted depositionwas also conducted on July 1, 1997.

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79

APPENDIX E

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3 2 1A

E

F

G

Meter Room

D

Elev.

Air Cond.Handling Eq.

Thermostat

Column cracked4’ below B/1 levelby west BM

Column cracked 6-7’Column cracked 2’below B/1 level

East ¼ of B1-C1 beamseparated 1-2”

1” separation

East ¼ of C1-D1 beamseparated 1 ½-3”

Singed cardboard &fiberglass samplestaken from B/1 jointwith beam.

C

East ¼ of D1-E1 beamseparated ½-4”

B/1 floor conn. deflected 4-6” west. Columncracked several places 3-7 ft. below B/1 level

Wall bowed 6-9” north and severely cracked

Upstairs

DownstairsChute Opening in Basement

West BM crackedcolumn 3’ belowB/1 level

Severe insidewall cracking

Lower 1/3 of north portionof wall displaced east 2-3”

Light surface cracking

Column in tact w/surface cracks

East ¼ of E1-F1 beamseparated ½-2”

4” CI sewer riser in wall

4” CI sewer pipeat B/1 level

BM cracked columnat 1st fl west side

1’ natural floor drain

Rebars exposed top & bottom of beam

Beam/beam rebars not embedded

Center cracked 1 ½ “ atbottom w/ no crack at top- north deflection

Upper 3’ wall cracked &tilted 6” with wall belowcrack moved west 2” at crack

Earth sump

Stairs

B

NOTE: Arrows indicate majordirection of resultant forces

81

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83

ABBREVIATIONS

ATF--Bureau of Alcohol, Tobacco and Firearms

CFR--Code of Federal Regulations

CGI--combustible gas indicator

DOT--U.S. Department of Transportation

Enron--Enron Corp.

FEMA--Federal Emergency Management Agency

GIS--Graphical Information System

Heath--Heath Consultants, Inc.

Humberto Vidal--Humberto Vidal, Inc.

LEL--lower explosive limit

MCC--maintenance and construction coordinator

NPRM--Notice of Proposed Rulemaking

O&M Manual--Operations and Maintenance Manual

OPS--Office of Pipeline Safety

PE--polyethylene

PRASA--Puerto Rico Aqueducts and Sewer Authority

PSC--Public Service Commission

PVC--polyvinyl chloride

RSPA--Research and Special Programs Administration

SJGC--San Juan Gas Company

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