on 4303 Lees Corner Road - Attachment No.<br><br> 10 3 Fairfax County Fire Department 9s Report 4 I. Executive Summary On December 19, 2010, at approximately 8:53 p.m., a natural gas explosion destroyed a home at 4303 Lees Corner Road in Chantilly, Virginia. There were no injuries.<br><br> The property damage was estimated at $391,215. The accident was investigated by the State Corporation Commission 9s Division of Utility and Railroad Safety. The results of the investigation are presented in this report.<br><br> Briefly, the investigation revealed that the gas service line to the home at 4303 Lees Corner Road experienced severe corrosion that resulted in a major gas leak in the road in front of the home. In addition, a section of customer owned natural gas fuel line terminating on the second floor of the home was discovered without an end cap. The investigation further concluded that the exact cause of this accident cannot be determined due to (1) the failure of Washington Gas Light Company to properly collect and document certain important information immediately after the accident relative to possible migration of natural gas, and (2) the absence of any evidence that the customer owned gas fuel line terminating on the second floor of the home was properly capped.<br><br> As a result of this investigation, a number of probable violations of the Commission 9s Pipeline Safety Standards have been cited. The Division of Utility and Railroad Safety 9s enforcement process provides Washington Gas Light Company an opportunity to respond to these probable violations before enforcement action is recommended to the Commission. 5 II.<br><br> Investigation The Accident On December 19, 2010, at 8:51 p.m., the Fairfax County Fire Department ( cFCFD d or cFire Department d), received a call from a resident at 4304 Willoughby Court in Chantilly, Virginia reporting a strong gas odor. Upon receipt of the odor call, the FCFD dispatched units to investigate. While en route, at approximately 8:53 p.m., an explosion and fire destroyed the home at 4303 Lees Corner Road.<br><br> This home was located in the back of the original call location. (See Attachment No. 1).<br><br> The FCFD was rerouted to 4303 Lees Corner Road and found the home destroyed and the roof structure appeared to have been lifted and the walls blown out. (Figure 1) There were no fatalities or injuries as a result of the explosion. According to the FCFD report, the property damage to the house and contents at 4303 Lees Corner Road was $391,215.<br><br> The homes on either side of the incident site suffered minor damage. The gas fed fire resulting from the explosion was fought by the FCFD and, ultimately 33 units and 76 personnel responded from the Fire Department. Post Accident Activities Immediately upon arriving at the scene, the firefighters inspected the neighboring houses for the presence of natural gas.<br><br> The Fire Department measured natural gas readings of five percent and eight percent of the lower explosive limit (LEL) of natural gas in the houses at 4300 and 4302 Lees Corner Road respectively which are directly across the street from the incident site. The FCFD also worked with representatives from Washington Gas Light Company ( cWGL d or cCompany d) to locate any gas leaks. Firemen reported cbubbling d along the curb in Figure 1 - Damage at 4303 Lees Corner Road Chantilly, VA.<br><br> 6 front of 4303 Lees Corner Road. Company crews barholed over the gas service line and along the gas main in the road and tested available openings such as manholes and valve boxes for the presence of natural gas. However, the WGL personnel did not document the results of these tests or readings as required by the Company 9s Operation and Maintenance Manual, Procedure 3020 and WGL 9s Emergency Plan, Procedure 1070.<br><br> In addition, the Company crews did not determine the extent of the gas migration. While they barholed over the gas service line towards the home at 4303 Lees Corner, the barholes did not extend past the curb. According to WGL, the barholes did not extend past the curb because the FCFD had restricted access to the area by taping off the site.<br><br> However, according to the Deputy Chief of the Fire Department, the Officer in Charge during the incident, FCFD would have allowed WGL to make some barholes towards the front of the structure and take readings once the fire was suppressed. Further, the Fire Department reported that they have a good liaison with the Company, and as WGL is the subject matter expert in dealing with natural gas, FCFD would have certainly allowed the Company crews to perform testing if they had asked to do so. As WGL personnel continued to barhole and test in the road, they found indications of a gas leak at the service tee where the gas service for 4303 Lees Corner Road comes off of the 6- inch steel gas main.<br><br> Upon excavation, WGL personnel noted severe corrosion on the copper gas service line at the service tee connection. Several photos showing the corrosion on the service line are found in Attachment No. 2 to this report.<br><br> The Company crews disconnected the service line from the gas main and cut off approximately 3 feet of the service line. A plug was installed in the service tee to shut off the flow of gas. The time of the temporary service line abandonment was not recorded by WGL.<br><br> This is important information in order to estimate the volume of gas that had escaped from this pipeline. Following the abandonment of the service line, Company crews took gas level readings inside the homes at 4300, 4302, and 4305 Lees Corner Road at 12:30 a.m. and 2:00 a.m.<br><br> on December 20, 2010. Two percent gas in air was noted inside the home at 4300 Lees Corner Road and six percent gas in air inside the residence at 4302 Lees Corner Road at 12:30 a.m. The follow-up readings taken at 2:00 a.m.<br><br> did not note the presence of gas inside any of these two homes (See Attachment No. 3). The presence of gas was not noted at either of these times for 4305 Lees Corner Road.<br><br> Division of Utility and Railroad Safety 9s Investigation The State Corporation Commission ( cCommission d) is the designated state agency for monitoring compliance with various pipeline safety regulations for the Commonwealth of Virginia including Title 49 Code of Federal Regulations ( cC.F.R. d) Part 192. The Commission has adopted this Part, among others, as its minimum pipeline safety standards ( cStandards d). The Division of Utility and Railroad Safety ( cDivision d) has been charged by the Commission with the compliance monitoring of the Standards relative to jurisdictional pipeline operators.<br><br> On December 19, 2010, at 10:58 p.m., the Division Staff ( cStaff d) received notice of the incident from WGL. The on-call Staff member reviewed the information provided by WGL with a Staff supervisor. Two investigators were dispatched to conduct an on-site investigation of this accident.<br><br> The two investigators (one from Richmond and one from Hopewell), traveled to the incident scene, and arrived on December 20, 2010 at 2:20 a.m. The Staff immediately met with representatives of the FCFD and WGL to assess the scene and learn what activities had transpired prior to Staff 9s arrival. 7 Staff learned that WGL 9s investigation had identified a gas leak in the street in front of the site of the explosion.<br><br> Company crews had excavated the proximate location of the leak and discovered that the ½-inch copper service to the incident site had severe corrosion with multiple holes in the service line piping within 6 inches of its connection to the steel gas main. Staff observed a WGL crew as it removed approximately 3 feet of the service line and installed a plug on the service tee fitting to stop the flow of gas. When the Company personnel removed the copper service from its insertion point into the service tee, approximately 3 inches of the service piping broke off into the hands of one of the WGL crew as a result of its corroded condition.<br><br> These two sections of copper gas pipeline line removed from service remain in the possession of WGL. In order to make a temporary repair 1 While the service tee was being plugged, another Company employee took a sample of natural gas on December 19, 2010 to have it analyzed for the presence of odorant. The results of the sampling showed that the odorant was readily detectable at 0.17% gas in air (See Attachment No.<br><br> 4). This is in compliance with the requirements of § 192.625 (a) wherein the odor must be readily detectable by a person with a normal sense of smell at one-fifth the lower explosive limit or approximately one percent gas in air. by plugging the service tee, Company crews had to reuse the original polymer sleeve that went into the coupling to electrically isolate the copper from the steel main as no spare ones were available.<br><br> WGL does not have a procedure for the reuse of this sleeve and states that this was a temporary action to make the area safe. The Company also does not have a procedure for making temporary repairs. While on site, a number of photographs depicting the scene were taken by Staff.<br><br> Several of these photos are found in Attachment No. 5. In addition, Staff interviewed the homeowner and several of the neighbors from surrounding homes on December 20 and 21, 2010.<br><br> The information gleaned from each person is as follows: Mr. Thuan Nguyen Mr. Thuan Nguyen is the owner of the residence at 4303 Lees Corner Road, the site of the incident.<br><br> Mr. Nguyen stated that he was home all day on December 19, 2010 and did not smell any natural gas, nor did he witness anything out of the ordinary. He said that at approximately 6:00 p.m.<br><br> that evening, a friend came to the house and took the family to dinner. Mr. Nguyen said that later that evening at approximately 8:00 p.m., he and the family had gone to a Christmas light show.<br><br> While at the light show, he received a phone call from a friend that his house had exploded. Mr. Nguyen returned to his home and found it engulfed in flames.<br><br> Mr. Andrew Lander Mr. Lander lives directly behind the incident site of 4303 Lees Corner Road at 4304 Willoughby Court.<br><br> Mr. Lander informed the Staff that, as he was driving home from the Safeway grocery store the night of December 19, 2010 at approximately 8:35 p.m, he smelled natural gas at the intersection of Pennsboro Drive and Lees Corner Road (see Attachment No. 1).<br><br> He stated that he thought the odor of gas may have been coming from a vacant home at 13621 1 The Company personnel returned on March 9, 2011, and installed a permanent abandonment fitting on the gas service line at 4303 Lees Corner Road. 8 Pennsboro Drive. As he was not sure what to do, he called a friend that worked for Fairfax County.<br><br> His friend suggested that he call the Fairfax County Fire Department which he did. Mr. Lander was responsible for the original call that prompted the Fire Department to respond to the area.<br><br> Mr. Lander noted that about two minutes after he made the call, the house behind him (4303 Lees Corner Road) exploded. Mr.<br><br> Kevin McCollum Kevin McCollum lives directly across the street from the incident site at 4302 Lees Corner Road. In his interview, Mr. McCollum stated that he was outside in his driveway talking on his cell phone when the incident occurred.<br><br> He yelled for his father, who came outside, and they both went over to the house after the explosion to look for any injured persons. Mr. McCollum stated that when he went into the house, he smelled natural gas and saw gas vapor coming from the furnace room.<br><br> At this point, the fire had not spread to the entire structure. When the Fire Department arrived, he described where he had checked for people in the house. He and his father both thought that the family was home because all vehicles were in the driveway.<br><br> Mr. Charles McCollum Charles McCollum lives directly across the street from the incident site at 4302 Lees Corner Road. He is Kevin McCollum 9s father.<br><br> Mr. McCollum informed the Staff that he was on his way to take the garbage out when he saw the house windows light up at about 8:52 p.m. He said that he and his son immediately ran across the street to look for the homeowner and his family at 4303 Lees Corner Road.<br><br> Mr. McCollum stated that he went up the stairs inside the front door, but debris blocked any further advance at the top of the stairs. He returned downstairs, looked into the garage and saw a car.<br><br> Mr. McCollum also reported seeing a constant blue flame coming from the floor in the area of the house where the utility room was located. He and his son then exited the home and went around back to check for people.<br><br> At this point, Mr. McCollum said that there was too much fire to do anything else, and he and his son went back across the street and watched the Fire Department arrive and begin to fight the fire. Mr.<br><br> Eric Harmon Mr. Harmon lives at 13618 Pennsboro Drive. He stated that he had just put his daughter to bed and was celebrating an early Christmas with other family members when the explosion occurred at approximately 8:52 p.m.<br><br> He had not noticed anything out of the ordinary immediately prior to the incident. He assisted Charles and Kevin McCollum in their efforts to ensure no one was inside the home at 4303 Lees Corner Road. Mr.<br><br> Harmon said he could smell gas across the street from 4303 Lees Corner Road between the sidewalk and the curb. Mr. George Fisher Mr.<br><br> George Fisher lives at 4305 Lees Corner Road, adjacent to the right side of the incident address. Mr. Fisher stated that on his way home at 6:30 p.m., he noticed a cweird smell d in front of the Brookfield Elementary School (See map in Attachment No.<br><br> 1). When he 9 got to his house, he did not notice any unusual odors. However, later that evening when Washington Gas excavated the service tee connection for 4303 Lees Corner Road in the street after the incident, Mr.<br><br> Fisher said he noticed the same smell as at the school. He also stated that it was a very windy night with the wind blowing south to north. At the time of the incident, Mr.<br><br> Fisher said that he was sitting in a chair inside and thought at first a plane had crashed because of the proximity to Dulles Airport. He went outside to check and found splinters everywhere and fire coming from the center of the remaining structure at 4303 Lees Corner Road. Mr.<br><br> Fisher was standing outside when the Fire Department arrived and began extinguishing the fire. Staff 9s investigation continued on December 20, 2010, while monitoring a pressure test conducted by WGL of the gas service line from the top of the service riser located behind the remains of the house at 4303 Lees Corner Road to where the service line was cut and capped the night before. The pressure test was conducted at a pressure of 55 pounds per square inch gauge ( cpsig d) for 15 minutes.<br><br> No leaks were found. The 55 psig level was chosen as it was the pressure in the gas lines at the time of the incident. WGL also conducted a leak survey on December 20, 2010, of the surrounding area and found a grade 2 leak 2 As part of its response to the incident, WGL used its Mobile Incident Command Center ( cCenter d) at the scene.<br><br> The Center is used by the Company to coordinate its response activities and the investigation process. Staff noted that the Center was not displaying any damage prevention education information. The Commission Order dated January 5, 2009, in Case No.<br><br> URS-2007-00238, required WGL, among other things, to c. . .<br><br> prominently display Virginia 9s damage prevention educational message on the outside of the trailer d when used in Virginia. located on a gas valve at the intersection of Willoughby Court and Pennsboro Drive. The valve was repaired that day by a WGL crew.<br><br> The approximate location of this valve is shown on the map found in Attachment No. 1. On December 21, 2010, Staff visited the Company 9s office to obtain copies of any and all documents and records related to the incident site and the surrounding area.<br><br> Subsequently, Staff continued to obtain and review relevant documents as the investigation progressed. A list of documents and records reviewed by the Staff is found in Attachment No. 6.<br><br> The Staff reviewed these records to determine compliance with the Commission 9s Standards. The discussion relative to the examination of records is in the following section. In an effort to determine whether natural gas had been leaking into the soil for some time, on December 22, 2010, the Staff requested WGL to take four soil samples at the approximate depth of the natural gas service line to 4303 Lees Corner and have them analyzed by an independent lab for the constituents of the odorant used by the Company.<br><br> Phase Separation Science, Inc. ( cPhase Separation d) out of Baltimore, Maryland was the lab chosen by the Company. The four sample locations were: 2 A grade 2 leak is defined as c[a] leak that is recognized as being non-hazardous at the time of detection, but justifies scheduled repair based on probable future hazard.<br><br> Leaks should be repaired or cleared within one calendar year, but no later than 15 months from the date the leak was reported. d This definition is found within the cGuide for Gas Transmission and Distribution Piping Systems d ( cGuide d) published by the Gas Piping and Technology Committee ( cGPTC d). The Guide contains information and some "how to" methods to assist natural gas operators in complying with Title 49 C.F.R. Parts 191 and 192.<br><br> The GPTC is an American National Standards Institute ( cANSI d) committee of stakeholders in the natural gas industry including distribution and transmission pipeline operators, manufacturers, and regulatory agencies. ANSI is a non-profit organization that oversees the development of voluntary consensus standards for products, services, processes, systems, and personnel in the United States. This definition is used by WGL for its grading of leaks.<br><br> 10 1. Adjacent to the gas service line under the home 9s concrete slab foundation, 2. Adjacent to the gas service line at the front edge of the home 9s concrete slab, 3.<br><br> Adjacent to the water service line entrance to the home, and 4. Approximately 5 feet from the front door entrance to the home. The analysis by Phase Science did not show detectable levels of any of the constituents of the odorant used in natural gas.<br><br> The laboratory analysis report is found in Attachment No. 7. It should be noted that in an effort to eliminate any residual sources of natural gas that may have migrated underground from the gas leak, WGL used air pressure to aspirate the roadway in front of the incident site.<br><br> As no gas readings were documented before or during the aspiration process, we cannot determine if this process had an effect on the possible absorption of odorant by the soil. On January 18, 2011, the Staff was on site with representatives from FORCON International ( cFORCON d), a forensic investigation company hired by the homeowner 9s insurance company to examine the remains of the home. At this time, a 1-inch diameter steel customer owned gas fuel line was noted on the second floor of the residence (Figure 2).<br><br> The end of this gas fuel line was open with no evidence of a cap being in place. FORCON took possession of this section of customer piping and has retained it since the time of discovery. On July 27, 2011, FORCON had the open end of this section of piping tested by Schneider Laboratories in Richmond, Virginia for the presence of pipe thread sealant.<br><br> The compounds found were typical byproducts from a fire. No indications of thread sealant were found. The results were provided to the Staff on August 23, 2011.<br><br> In an effort to determine if the sewer mains and laterals in the area may have served as a conduit for leaking natural gas to reach the home, on January 26, 2011, and February 4, 2011, the Staff, along with representatives from WGL and its forensic consultant, Rothfuss Engineering Figure 2 - An open customer fuel line terminated on the second floor of home. 11 Company, the investigator from FORCON (hired by the homeowner 9s insurance company), and Insight Utilities 3 Insight Utilities 9 inspection of the sewer lateral to 4303 Lees Corner Road did not discover any issues. However, two possible defects in the sewer main were found in the roadway.<br><br> Additionally, the sewer lateral serving 4302 Lees Corner Road also had a possible defect. This sewer lateral was located approximately 9 feet horizontally and 17 feet vertically from the gas service line connection to the gas main. , monitored the results of a video camera inspection of these pipes.<br><br> The sewer system in this area is constructed of a 10-inch concrete sewer main with 4-inch cast iron laterals serving the homes. The lateral connection to the sewer main for 4303 Lees Corner Road was 8 feet horizontally and 17 feet vertically (in depth) away from the gas service line connection to the gas main. Lastly, on February 17, 2011, Staff attended a homeowner 9s association meeting organized by the Brookfield Civic Association to update the residents relative to the incident.<br><br> This meeting was also attended by representatives of the FCFD and WGL. Review of Records As part of Staff 9s investigation, the Staff reviewed a number of WGL records, Fairfax County real estate and building records, various laboratory analyses, and FCFD call logs and incident summary report. A list of the records reviewed is found in Attachment No.<br><br> 6. Our findings are as follows: Pipeline Information According to the Company 9s records, the gas service line to 4303 Lees Corner Road was installed on July 15, 1966. After reviewing WGL 9s records, it does not appear that there have been any alterations or repairs to this service line.<br><br> The service line consisted of ½-inch copper tubing, known as Type K, with an original wall thickness of 0.047-inch. A polymer sleeve was used at the service tee connection at the time of installation to insulate the copper service line from the galvanic cathodic protection system used to protect the 6-inch wrapped steel main from corrosion. At the time of installation, the maximum allowable operating pressure for the service line was established as 60 psig.<br><br> Since the date of installation, the operating pressure has been approximately 55 psig. A residential service regulator and meter were also installed on the gas service line at the rear of the house. The service regulator reduces the gas pressure to approximately 0.25 psig before the natural gas enters the customer 9s fuel line piping.<br><br> A three- year history of the gas use ending on December 19, 2010 at 4303 Lees Corner Road was reviewed and no abnormalities were noted. Mr. Nguyen purchased the home in 2008 and constructed two additions to the house at that time.<br><br> One of the additions was a two story extension constructed on the right side of the home which included a garage. Another two story addition was constructed on the left side of the home. Before constructing the additions, Mr.<br><br> Nguyen called in a notice of excavation to Virginia 9s notification center on April 1, 2008 requesting that both sides of his property be marked as to the location of any underground utility lines as well as 12 feet out from the front of 3 Insight Utilities, Inc. is a company that provides subterranean utility locating and identification through the use of various technologies such as ground penetrating radar and in-line video cameras. 12 the house.<br><br> The ticket number from the notification center is A809201352-00A. A copy of the ticket is found in Attachment No. 8.<br><br> The left side addition to the house was built on a poured concrete slab. The concrete slab foundation was poured over the existing ½-inch copper gas service that WGL owned and operated (Figure 3). The Company received notice on April 1, 2008, via Ticket No.<br><br> A809201352-00A, that additions to the home were to be constructed. WGL reported that the location of its gas service line was marked on April 3, 2008. The homeowner or his contractor should have noticed the conflict between the existing gas service line and the addition, and should have requested WGL to relocate the line.<br><br> Additionally, the Company 9s locator should have reported this conflict and WGL should have relocated its service line at that time. Subsequently the left side addition was built over WGL 9s gas service line. Section 192.614 (c)(6) of the Commission 9s Standards requires gas operators to make inspections as frequently as necessary of pipelines that they believe could be damaged by excavation activities.<br><br> WGL developed Operations and Maintenance Standards 4099, Damage Prevention Monitoring, in an effort to comply with Section 192.614 (c)(6). The Company had received notice that additions were being built on the house at 4303 Lees Corner Road and WGL should have known that their service line was located adjacent to the existing structure. Staff could find no documentation of any inspections performed at this address after the service line was located by WGL and marked on April 3, 2008.<br><br> The Commission 9s Standards also prohibit the existence of a gas service line under a building unless it is installed in a gas-tight conduit (§ 192.361 (f)). In order to comply with this requirement, the Company 9s Operations and Maintenance Standards does not allow a service line to be installed under a building unless certain conditions are met. Furthermore, §192.613 (a) of the Commission 9s Standards requires natural gas operators to have a procedure for continuing surveillance of its facilities to determine and take appropriate action relative to, among others, c&unusual operating and maintenance conditions. d Section 4053, Continuing Surveillance, of WGL 9s Operation and Maintenance Standards was developed to comply with this section of the Commission 9s Standards.<br><br> This section of the Company 9s Operation and Maintenance Standards states, among other things, that the Company Figure 3 - Diagram showing location of gas line running under concrete slab, and location of leak found. 13 c&continuously surveys its facilities to determine and take appropriate action in unusual operations and maintenance conditions. d Section 4053 goes on to say that c&[d]ecisions for pipeline repair or replacement are based on the physical condition of the pipe, location of the pipe, pressure in the pipe, and other safety related factors. d Staff 9s review of WGL 9s records found that this service line was last surveyed for the presence of leaks on June 1, 2009. However, no documentation exists that demonstrates how WGL conducted a leak survey of the service line as it continued under the concrete slab.<br><br> Staff also did not find any documentation of any examinations of this address by WGL pursuant to Section 4053, Continuing Surveillance of its Operation and Maintenance Standards. Cathodic Protection Records The Commission 9s Standards require that all metallic pipelines installed underground since August 31, 1971 be protected against corrosion and that this protection must be monitored annually. In addition, all gas distribution pipelines installed prior to August 31, 1971 must also be cathodically protected in areas in which active corrosion is found.<br><br> WGL has cathodically protected the 6-inch steel gas main installed in Lees Corner Road in 1966 and continues to monitor the effectiveness of the cathodic protection on this pipeline. Staff reviewed WGL 9s records for cathodic protection of facilities designed to protect the gas main serving 4303 Lees Corner Road and the surrounding area and could find no issues with this documentation. However, Staff did not identify any records of inspections or tests taken to ensure compliance with §192.467 (d) of the Commission 9s Standards.<br><br> This Standard requires, among other things, that inspections and electrical tests must be made to c&assure that electrical isolation is adequate. d The electrical isolation of the Company 9s cathodic protection facilities is required under §192.467 (a) of the Commission 9s Standards. This section requires, among other things, that each pipeline c&must be electrically isolated from other underground metallic structures. d As discussed earlier, the copper service line had a polymer sleeve installed at the service tee to electrically isolate the copper service from the steel gas main in compliance with §192.467(a). Leak Repair Records The leak repair records for the area of the incident were reviewed from July, 2006 to the present.<br><br> Three service lines experienced leaks which were repaired during this time. The services located at 4311 and 4313 Lees Corner Road were both repaired for corrosion leaks in 2008. The service line at 4217 Lees Corner Road had a corrosion leak repaired in 2009.<br><br> However, the Company repaired a total of 683 copper service leaks on its Virginia system during this same time frame. According to WGL, the 5-year average leak rate for copper services is 0.131 leaks per 100 services as compared to the 5-year average leak rate for bare steel services which is .440 leaks per 100 services. Pressure Control Records Staff reviewed the Supervisory Control and Data Acquisition (SCADA) pressure charts for the system serving this area.<br><br> The system was operated at approximately 55 psig from December 19, 2008 through the date of the incident. No issues were noted. 14 Open-ended Customer Owned Fuel Line As previously stated, this section of the interior fuel line was found on January 18, 2011 upon further examination of the remaining debris from the house.<br><br> Based upon Staff 9s discussions with other homeowners and a review of original records for the home, this fuel line appears to have been connected to a natural gas stove when the kitchen of the home was located on the second floor. Prior to Mr. Nguyen 9s purchase of the home, the kitchen was moved to the first floor.<br><br> An examination of the structure revealed that this portion of the fuel line would have been located inside an interior wall. Other Utilities on the Property Several other underground utilities were located on the property of 4303 Lees Corner Road. Cox Cable and Dominion Virginia Power 9s ( cDominion d) street light power cable were crossing the front of the property.<br><br> In the street, there were Fairfax County 9s ( cFFC d) water and sewer mains, and the WGL gas main. Each of these utility mains served 4303 Lees Corner and adjacent properties in the area through service lines. On the right side of the property there was a Dominion power primary cable, Verizon phone line, and Verizon FIOS facilities.<br><br> On the rear of the property there was a Dominion power service cable and a Verizon FIOS service line to the home. Both of these utilities entered the home from the rear. A diagram showing these utilities is found in Attachment No.<br><br> 9. Additional Field Investigation During the investigation of this incident, Staff noted several issues with the Company 9s cathodic protection and leak survey processes. As a result, on November 16, 2011, the Staff visited the incident area and had WGL perform additional testing.<br><br> A number of cathodic protection readings were taken around the address of the incident. Staff also monitored a leak survey of 38 gas service lines and the associated gas mains in the area. Based on our previous analyses of the records, and the findings from the field, our investigation into the Company 9s cathodic protection and leak survey processes will continue.<br><br> III. WGL Investigation According to WGL 9s investigation report filed with the Division, the Company c. .<br><br> . believes that two potential sources of natural gas exist. d These two sources are c. .<br><br> .the corrosion leak located in the street&and&the open fuel line located in the dwelling. d WGL concludes that the c. . .<br><br> root cause of this incident remains undetermined as other investigations may be ongoing. d 15 IV. Fairfax County Fire Department Investigation FCFD has closed its investigation and concluded that the explosion and subsequent fire at 4303 Lees Corner Road was accidental and created by the release of natural gas. The Fire Department 9s report further concludes that the probable ignition source was the open flame water heater located in the first floor utility room.<br><br> The FCFD 9s report did not indicate the source of the natural gas. A copy of the FCFD 9s report is presented an Attachment No. 10 to this report.<br><br> V. Findings Based upon its investigation, Staff notes the following findings: 1. Just prior to the incident, a resident reported a smell of gas in the road in front of Brookfield Elementary School, approximately 250 yards from the incident site; 2.<br><br> The homeowner at 4304 Willoughby Court, located immediately behind 4303 Lees Corner Road, noticed a strong smell of gas at the intersection of Pennsboro Drive and Lees Corner Road. This homeowner was the person who called 911 and reported the strong odor of gas; 3. Another resident noticed a strong smell of gas between the curb and sidewalk across the street from 4303 Lees Corner Road; 4.<br><br> The Fire Department reported cbubbling d at the curb in front of 4303 Lees Corner Road; 5. Soon after arrival to the scene, the Fire Department measured five percent and eight percent of the LEL of natural gas in the homes located at 4300 and 4302 Lees Corner Road respectively. These levels dropped to zero percent by 2:00 a.m.<br><br> December 20, 2010 after the leak on the service line to 4303 Lees Corner Road was repaired; 6. The natural gas was odorized such that it was readily detectable by a person with a normal sense of smell at approximately 0.17% gas in air; 7. WGL did not document the initial combustible gas readings taken upon their arrival to the site.<br><br> The only documented readings taken occurred after the leak on the service line to 4303 Lees Corner Road had been repaired; 8. Based on the information from several residents in the area, and the Fire Department, gas was migrating from the leak on the service line. The Company did not fully identify the gas migration area.<br><br> The barholes and testing performed as a result of this incident by WGL crews was to find the leak. The extent of the gas migration or its path was never determined; 9. WGL did not perform any barhole testing past the curb at 4303 Lees Corner Road.<br><br> According to the Company, barhole testing was not conducted because the Fire Department had restricted access to the area. However, Staff 9s discussions with the Fire Department indicated that permission to perform such testing up to the front of the structure would have been granted upon request; 10. Severe corrosion created a number of holes in the natural gas service line serving 4303 Lees Corner Road at the connection to the service tee on the steel main.<br><br> The piping had been weakened to the extent that a portion of the service line broke off when it was removed from the ground. Natural gas would have been 16 escaping from these holes at 55 psig; 11. WGL did not take any readings of combustible gas in the soil prior to beginning to aspirate to remove residual natural gas in the ground; 12.<br><br> An open ended section of customer owned natural gas fuel line terminating on the second floor of the home was found. Testing of the threads on the open end did not identify any constituents of thread sealant that may have been placed on the pipe if a cap was installed. As the interior fuel lines operate at approximately 0.25 psig, gas would have been escaping from this opening at that pressure until the service regulator ceased to function properly as a result of damage from the incident; 13.<br><br> The homeowner built two additions to the home and gave notice of the construction to Virginia 9s notification center on April 1, 2008. WGL marked the service line to 4303 Lees Corner Road on April 3, 2008. The homeowner or his contractor did not request the Company to move the gas service line so it would not have been in conflict with the home addition; 14.<br><br> The addition built in 2008 on the left side of the house was built on a concrete slab poured directly over WGL 9s gas service line; 15. WGL received notice of the proposed construction for the additions to the home via the notification center on April 1, 2008 and marked the gas service line on April 3, 2008. The Company did not identify that the addition was being constructed over its gas service line and that the gas service line should be moved; 16.<br><br> WGL performed a leak survey of its facilities in this area on June 1, 2009. No record was provided that demonstrated the service line to 4303 Lees Corner Road was surveyed for leaks under the house; 17. The Fire Department concluded that the incident was caused by the accidental release of natural gas.<br><br> The origin of the natural gas was not determined by the Fire Department; and 18. WGL concluded that two potential sources of the natural gas existed. As a result, the Company states that the c.<br><br> . . root cause of this incident remains undetermined. d WGL neither collected nor documented important information and, therefore, certain necessary facts are unknown such as the extent of the gas migration and the combustible gas readings in the soil taken prior to the service line repair and aspiration of the soil.<br><br> The testing of the open ended section of the customer owned fuel line terminating on the second floor of the home did not conclusively show this pipe was capped. Accordingly, the Division of Utility and Railroad Safety cannot determine the source of the natural gas that caused the December 19, 2010, accident at 4303 Lees Corner Road in Chantilly, Virginia. VI.<br><br> Probable Violations Below is a list of cprobable violations d of the Commission's Standards that the Division of Utility and Railroad Safety has noted as a result of its investigation of this incident. The Division 9s enforcement process provides WGL an opportunity to review this report and respond to the cprobable violations d, before an enforcement action is recommended to the Commission. 17 1) 49 C.F.R.<br><br> § 192.605 (a) - Failing to follow the Company 9s Operations and Maintenance Standard, Section 3020, by not recording test readings of natural gas discovered on Company 9s Maintenance Field Orders on December 19, 2010 after the incident that occurred at 4303 Lees Corner Road, Chantilly, Virginia; 2) 49 C.F.R. § 192.605 (a) - Failing to follow the Company 9s Emergency Plan Standard, Section 1070, by not documenting specific leakage test readings and locations of natural gas discovered as part of the Company 9s on-site investigation on December 19, 2010 at the incident that occurred at 4303 Lees Corner Road, Chantilly, Virginia; 3) 49 C.F.R. § 192.605 (a) - Failing to follow the Company 9s Operations and Maintenance Standard, Section 4050, which was developed to comply with 49 C.F.R.<br><br> § 192.721, by not observing a condition that may affect the safety and operations of a pipeline. Specifically the service line that was located under a concrete foundation at 4303 Lees Corner Road, Chantilly, Virginia was not identified as a condition that impacted WGL 9s facilities; 4) 49 C.F.R. § 192.605 (a) - Failing to follow the Company 9s Operations and Maintenance Standard, Section 4010, by not performing a complete leak survey on June 1, 2009 of a residential service line as a result of the service line being located under a concrete foundation at 4303 Lees Corner Road, Chantilly, Virginia; 5) 49 C.F.R.<br><br> § 192.605 (a) - Failing to follow the Company 9s Operations and Maintenance Standard, Section 4010, by not identifying and recording a cservice violation d of the service line that was located under a concrete foundation at 4303 Lees Corner Road, Chantilly, Virginia during the June 1, 2009 leak survey; 6) 49 C.F.R. § 192.605 (a) - Failing to follow the Company 9s Operations and Maintenance Standard, Section 3019, by not documenting the natural gas migration on December 19, 2010 after the incident that occurred at 4303 Lees Corner Road, Chantilly, Virginia; 7) 49 C.F.R. § 192.605 (b)(1) - Failing to have a procedure for the temporary abandonment of copper service lines.<br><br> 8) 49 C.F.R. § 192.605 (b)(1) - Failing to have a procedure for reuse of the polymer isolation sleeve on copper service lines. 9) 49 C.F.R.<br><br> § 192.467 (d) 3 Failing to make inspections and tests to assure that the electrical isolation of the copper service line from the cathodically protected steel main was adequate. 10) 49 C.F.R. § 192.614 (a) 3 Failing to monitor excavations over Company facilities as required by Company 9s Operations and Maintenance Standard 4099, Damage Prevention Monitoring, developed to comply with § 192.614 (c)(6).<br><br> 11) Failure to comply with the Commission Order of Settlement in Case No. URS-2007- 00238 4 by not prominently displaying Virginia 9s damage prevention educational messages on the outside of the incident command trailer. 4 See State Corporation Commission v.<br><br> Washington Gas Light Company , Case No. URS-2007-00238, 2009 S.C.C. Ann.<br><br> Rept. 644, Order of Settlement (Jan. 5, 2009).<br><br> Sketch of Incident Area Attachment No. 1 Photo taken December 20, 2010 of gas service line and tapping tee, in-situ, serving 4303 Lees Corner Road Copper Gas Service Line serving 4303 Lees Corner Road. Corrosion Hole in Gas Service Line Wrench inserted into gas service connection to main to shut off the flow of gas Attachment No.<br><br> 2 3 Pa e 1 of 5 Photo taken December 20, 2010 showing removed pieces of the copper gas service line serving 4303 Lees Corner Road Attachment No. 2 3 Pa e 2 of 5 Photo taken December 22, 2010 at WGL office showing overview of gas service line for 4303 Lees Corner Road as removed from site Attachment No. 2 3 Pa e 3 of 5 Photo taken December 22, 2010 at WGL office - close-up of the severe corrosion on the gas service line to 4303 Lees Corner Road Attachment No.<br><br> 2 3 Pa e 4 of 5 Photo taken December 22, 2010 at WGL office - close-up of the severe corrosion on the gas service line to 4303 Lees Corner Road Attachment No. 2 3 Pa e 5 of 5 Attachment No. 3 Attachment No.<br><br> 4 Photo taken December 20, 2010 of left Side of 4303 Lees Corner Road Attachment No. 5 3 Page 1 of 4 Photo taken December 20, 2010 of damage to left side of 4301 Lees Corner Road Attachment No. 5 3 Page 2 of 4 Photo taken December 20, 2010 of remains of gas meter and service regulator at 4303 Lees Corner Road Attachment No.<br><br> 5 3 Page 3 of 4 Photo taken December 20, 2010 of gas meter and service regulator as removed from 4303 Lees Corner Road Attachment No. 5 3 Page 4 of 4 Attachment No. 6 3 Page 1 of 2 List of Documents and Records During the course of the Division of Utility and Railroad Safety 9s investigation of the December 19, 2010 incident at 4303 Lees Corner Road, Chantilly, Virginia, the following documents and records were reviewed: 1.<br><br> WGL Call Center records for December 19, 2010; 2. Copies of witness interviews conducted by WGL; 3. SCADA pressure charts for all pressure regulating stations serving this system; 4.<br><br> All records related to any customer leak calls in this area; 5. All records of any other customer calls in this area; 6. All records of WGL service calls in this area; 7.<br><br> List of all pipeline facility renewals in the area in the last 5 years; 8. Maps of the natural gas facilities in the area; 9. Cathodic protection records for any gas facilities in the area; 10.<br><br> Results of all leak surveys in the past 10 years; 11. List of all WGL and contractor employees on site following the incident; 12. Operator Qualification records and training modules for employees that performed leak surveys; 13.<br><br> All records related to the gas service for 4303 Lees Corner Road; 14. WGL Operation and Maintenance Standards; 15. Maintenance Field Orders for 4303 Lees Corner Road and the surrounding area; 16.<br><br> Leak repair records for the last 5 years for this area; 17. Laboratory analysis of gas sample for odorant taken by WGL; 18. Laboratory analysis of soil samples for odorant; Attachment No.<br><br> 6 3 Page 2 of 2 List of Documents and Records 19. Laboratory analysis of open end pipe section for thread sealant; 20. Gas distribution system patrolling records for this area; 21.<br><br> Natural gas consumption history for 4303 Lees Corner Road for the past 3 years; 22. WGL 9s Failure Investigation Report; 23. WGL 9s Incident Report 3 Gas Distribution System 3 filed with the Pipeline and Hazardous Materials Safety Administration; 24.<br><br> Fairfax County Fire Department Incident Summary Report; 25. Transcripts of the 911 calls from December 19, 2010, relative to the incident at 4303 Lees Corner Road; 26. Fairfax County Tax Records for 4303 Lees Corner Road; 27.<br><br> Fairfax County Building Permits for 4303 Lees Corner Road; 28. Records of all notices of excavation made to Virginia 9s notification center for the last 10 years for 4303 Lees Corner Road; 29. Photographs taken by WGL; and, 30.<br><br> Photographs taken by the Fairfax County Fire Department. Analytical Report for Washington Gas - Chemical Service Lab Certificate of Analysis No.: 10122827 Project Manager: Steve Riley Project Name: 4303 Lees Corner Rd. January 6, 2011 Phase Separation Science, Inc.<br><br> 6630 Baltimore National Pike Baltimore, MD 21228 Phone: (410) 747-8770 Fax: (410) 788-8723 Page 1 of 5 Attachment No. 7 - Page 1 of 4 OFFICES: 6630 BALTIMORE NATIONAL PIKE ROUTE 40 WEST BALTIMORE, MD 21228 410-747-8770 800-932-9047 January 6,2011 Steve Riley Washington Gas - Chemical Service Lab 6801 Industrial Rd., Rm. 278 Springfield VA 22151 PHASE SEPARATION SCIENCE, INC.<br><br> Reference: PSS Work Order No: 10122827 Project Name: 4303 Lees Comer Rd. Dear Steve Riley: The attached Analytical and QC Summary lists the analytical results from the analyses performed on the samples received under the project name referenced above and identified with the Phase Separation Science (PSS) Work Order numbered 10122827. Analyses associated with analyst code 4010 were performed by Maryland Spectral Services, Inc.<br><br> All work reported herein has been performed in accordance with current NELAP standards referenced Methodologies, PSS Standard Operating Procedures and the PSS Quality Assurance Manual with the exception of TO-IS MOD. PSS is limited in liability to the actual cost of the sample analysis done. PSS reserves the right to return any unused samples, extracts or related solutions.<br><br> Otherwise, the samples are scheduled for disposal, without any further notice, on February 1, 2011. This includes any samples that were received with a request to be held but lacked a specific hold period. It is your responsibility to provide a written request defming a specific disposal date if additional storage is required.<br><br> Upon receipt, the request will be acknowledged by PSS, thus extending the storage period. This report shall not be reproduced except in full, without the written approval of an authorized PSS representative. A copy of this report will be retained by PSS for at least 10 years, after which time it will be disposed without further notice, unless prior arrangements have been made.<br><br> We thank you for selecting Phase Separation Science, Inc. to serve your analytical needs. If you have any questions concerning this report, do not hesitate to contact us at 410-747-8770 or info@phaseonline.com.<br><br> Dan Prucnal Laboratory Manager Page 2 of 5 Attachment No. 7 - Page 2 of 4 Project ID: N/A Case Narrative Summary Client Name: Washington Gas - Chemical Service Lab Project Name: 4303 Lees Corner Rd. Work Order Number: 10122827 Any holding time exceedances, deviations from the method specifications, regulatory requirements or variations to the procedures outlined in the PSS Quality Assurance Manual are outlined below.<br><br> Sample Receipt: All sample receipt conditions were acceptable. Analyses associates with analyst code 4010 were performed b ~ Maryland Spectral Services, Inc. General Notes: The sample was prepared by weighing 20g of soil material into a headspace analysis vessel.<br><br> The vessel was allowed to equilibrate for 30 minutes prior to analysis. 400 cc of heads pace was analyzed from the headspace vessel. NELAP accreditation was held for all analyses performed unless noted below.<br><br> See w""",'V.phaseonline.com for complete PSS scope of accreditation. TO-15 Page 3 of 5 Attachment No. 7 - Page 3 of 4 OFFICES: 6630 BALTIMORE NATIONAL PIKE ROUTE 40 WEST BALTIMORE, MO 21228 410-747-8770 800-932-9047 FAX 410-788-8723 Project Name: 4303 Lees Corner Rd.<br><br> Project Location: Chantilly PHASE SEPARATION SCIENCE, INC. CERTIFICATE OF ANALYSIS No: 10122827 Washington Gas - Chemical Service Lab January 6, 2011 ~ : ; i J t f . ~ ; : j ~ f ~ ~ : .<br><br> · . , i ; ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ; Y ~ ; = I : ! : L f I ~ : _ ~ ~ ~ ~ ' [ 1 1 ~ ~ ~ ~ ~ i ~ .<br><br> ~ ~ ~ ~ ~ _ I r 0 ! - ~ 2 ~ : } ~ i l i ~ ~ ~ j 1 ~ ~ i ? : 0 1 ..<br><br> ·c Volitile Organic Compounds in Air Dimethyl sulfide' 2-methyl-2-Propanethiol (TBM) Analytical Method: TO-15 Modified Result Units NO ug/M3 ND ug/M3 RL 5.1 3.7 Flag Oil Analyzed Analyst 1.0 12/29/2010 4010 1.0 12/29/2010 4010 - ~ ~ - . . , ~ - - ~ - ~ ~ - _ ~ ~ ~ __ ~ - ~ .<br><br> ~ , ~ . ...,........,.---o"- ___ ~ - _ - , - ~ , . , .<br><br> . , - = - - : - - - ~ - - - .... ~ .<br><br> - - . - - - , - . - - - .<br><br> , . . .<br><br> . . .<br><br> - - - - - - " - Sample' I O : B ~ f r o n t ' c ~ ',' ." . , .. , .<br><br> . i";;" o i:ttelTi me Sampled: 1 2 / ~ 3 / ? Q 1 0 .<br><br> ~ 5:00_-;;; PSS' SajnplelO; 1, 01?,2827 -002, ' .".""" ~ ~ t _ r ~ i x ~ o P . ! _ R _ i .<br><br> _ ~ . ~ . · , · ~ ~ , i ~ _ ..<br><br> ~ ~ ~ : ~ ~ ~ ' ' " . ~ __ = ~ p a t ~ f t l ~ e R e ~ i l ! ~ ~ : 1 2 1 ~ ~ .<br><br> £ 2 0 1 0 1 _ ~ : . ! O ~ : L ~ ~ ~ ___ ~ _ ' , , .<br><br> ~ . ~ ~ , : __ ~ _ ~ ~ ~ ' c _ ~ ___ :' ~ _ . _.<br><br> , Volitile Organic Compounds in Air Dimethyl sulfide' 2-methyl-2-Propanethiol (TBM) Volitile Organic Compounds in Air Dimethyl sulfide' 2-methyl-2-Propanethiol (TBM) Analytical Method: TO-15 Modified Result Units ND ug/M3 ND ug/M3 Analytical Method: TO-15 Modified Result Units NO ug/M3 ND ug/M3 RL 5.1 3.7 RL 5.1 3.7 Flag Oil Analyzed Analyst 1.0 12/30/2010 4010 1.0 12/30/2010 4010 Flag Oil Analyzed Analyst 1.0 12/30/2010 4010 1.0 12/30/2010 4010 Sample I I j T [ F ~ ' - - - ' DateITlmce Sample-£12i23120-fo 14:45 .. -PSS SampleIO:,10f22827-004 f \ I I a t r l ~ ~ ~ ! L i : ~ " - ~ ~ ___ ~ , : ~ ~ ___ ~ .<br><br> __ ~ Q ~ i ~ / T i m ~ - ' ~ ~ ~ i l ! y ~ ~ ~ g / ~ 8 / 2 Q 1 0 1 6 : 4 < ! : .<br><br> ~ _ , _ ~ · , . ~ ~ ~ ~ ~ _ ~ } ; . _ ~ _ - : : L ~ ~ ~ _ ~ ___ _ Volitile Organic Compounds in Air Analytical Method: TO-15 Modified Result Units RL Flag Oil Analyzed Analyst Dimethyl sulfide' NO ug/M3 5.1 1.0 12/30/2010 4010 2-methyl-2-Propanethiol (TBM) ND ug/M3 3.7 1.0 12/30/2010 4010 * - Dimethyl sulfide limit of quantitation is estimated.<br><br> Page 4 of 5 Attachment No. 7 - Page 4 of 4 Attachment No. 8 - Page 1 of 2 Attachment No.<br><br> 8 - Page 2 of 2 Diagram of Utility Locations on 4303 Lees Corner Road Attachment No. 9 Attachment No. 10 - Page 1 of 3 Attachment No.<br><br> 10 - Page 2 of 3 Attachment No. 10 - Page 3 of 3

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