On July 24, 2001 at 1730 hrs., Lancaster County HAZMAT 2-9 was dispatched to assist Sta. 2-7 at the scene of a hazardous materials incident located at Buch Ave. & Weaver Road in Manheim Twp. Initial reports from County radio indicated that there was an underground gas line rupture. A large black cloud of smoke could be seen rising several hundred feet into the northern sky from miles away. First arriving fire apparatus found the source of the fire to be a Mobil pipeline junction station. Several trucks and a trailer were parked along the East Side of the roadway adjacent to the fenced area of the junction station. The entire area of the junction station (approx. 20’ x 30’), was engulfed in flames extending vertically, approx. 100 ft. The black plume of smoke extended several hundred feet higher and was traveling due east of the fire. Initial weather conditions at that time were clear skies, 89-degree temperatures, with a 5-10 mph wind out of the west. The initial report from fire department was that Mobil employees were pressure testing a branch gasoline distribution line when a leak or rupture occurred and was ignited. All four workers were able to escape the area without injury when the explosion occurred.

HM 2-9-1, 2-9-2 & 2-9-3 all responded to the incident, with an initial crew of 11 technicians. 2-9-1 (the main response unit), was instructed to locate on the north side of the fire, 2-9-2 (the quick response unit), located on the south side, and 2-9-3 (a utility van), was used to transport additional supplies of foam to the fire apparatus located on the north.

The fire department established an initial exclusion zone of approximately 1 mile, between the two adjacent roadways leading into the fire area. All non-fire related personnel were requested to leave the area. Fire fighting operations focused on protecting the exposures and allowing the fuel to burn. The nearby trailer was reported to be loaded with small equipment, a transport vehicle, gasoline and pipe repair materials.

Preliminary discussions with fire command established that hazmat operations would consist of air monitoring and runoff control. Recon teams would be needed to survey the surrounding area for streams and possible runoff accumulation areas.

A Hazmat Sector was established, consisting of a HM Sector Commander, Operations Chief, Safety Officer, North/East Recon team (2 members) and a South/West Recon team (2 members). A medical unit that was originally dispatched to the scene was utilized as a Hazmat Medical Sector for the hazmat team. Engineer 2-9-1 was stationed at the vehicle to control equipment dissemination. Additional support personnel were instructed to ready air monitoring meters, runoff control booms, and water/soil sampling equipment. A scribe was assigned to the Chief to document all HM 2-9 activities.

Research personnel found that according to Manheim Twp. Emergency Response Manual drawings and county maps, an un-named stream was running east to west on the north side of the fire area.

Both recon teams were initially equipped with Industrial Scientific quad gas meters and radios. Each team was instructed to sweep through a circular perimeter on the east or west side of the fire to locate the stream and monitor for LEL & CO on the quad meters. A second branch stream was also noted to feed into the stream on the west side of the fire.

The South/West Recon team located a small, dry creek bed. Further investigation to the west located a standing pool of water that fed into a small stream, running north to south. Based on county maps, this stream fed into the Little Conestoga creek. One member of the recon team had a digital camera with a zoom lens and was able to take close-up shots of the source of the fire. A bright yellow stream of flames was visible, indicating that the lines were under considerable pressure. Mobile crews were sent to shut off mainline valve in each direction. The closest isolation valves were approximately 12 miles off in each direction.

The North/East Recon team did not discover any sings of a dry creek bed within the field on the east side of the fire, nor were there any signs of runoff water accumulation.

The South/West Recon was instructed to deploy 5”petroleum booms at the head of the dry creek bed, at the head of the standing water, at the head of the moving stream and across the moving water stream.

At 1900 hrs. the SW Recon team reported that runoff water was beginning to reach the booms. The water was reported to be clear. The NE Recon team reported that no runoff water was detected on the east side. FD Incident Command and HM Sector Command discussed locations for possible backhoe/bulldozer operations and arrangements were made to bring in heavy equipment for possible diking operations. Representatives from Lewis Environmental were on-scene working with Mobil employees when the explosion occurred, so they were able to assist in obtaining heavy equipment and manned the diking operations.

At 1915 hrs. The Manheim Twp. Command Bus arrived and all command operations relocated to the command bus. There was a noticeable change in the flames, there would be large flare-ups and then the flames would die down. Discussions with Mobil reps and engineers revealed that the leaking vapors were being consumed and the fire would reach into the pipeline seeking more fuel. All sectors were instructed to continue to monitor for LEL during this period of lessened flame. Helicopters and planes were noted flying around and through the area so the FD was requested to designate a no-fly zone due to the unknown risk of secondary explosions. The Lancaster Airport was less than 2 miles from the fire site.

When DEP reps from Lancaster, Harrisburg and Reading arrived on scene, they were given a HM 2-9 hi-band radio so we could communicate directly with them while they were out on the fire ground. The SW recon team reported that there were cows in the field drinking the runoff water. The FD contacted the farmer to have the cows moved inside. The also reported that the drainage was increasing and booms were being swept away. Signs of product (gasoline) were also visible in the water. Additional booms and steaks (to secure the booms) were taken to the area. HM Sector Command requested operations to take water samples and to test for flammability.
The Operations Chief expanded operations to incorporate water sampling and re-designated the teams:
Team A (East Recon)
Team B (West Recon)
Team C (South West Recon)
Team D (Hazcat testing)
Team A reported that multiple streams of water were beginning to run through the E. Sector. Runoff water was beginning to flow east between the cornrows. Water was black, sooty and contained some product. Command discussed the need for booms or backhoe operations, but decided that the uphill terrain would force the water to flow back toward the fire and stream area. The W. Sector was designated the #1 priority for backhoe operations at this time. FD personnel assisted with shovel operations to build small containment dams in the E. Sector. Water flow was slowed to a minimum.

At 2100 hrs. neighbors began to report crackling & popping sounds in the underground lines. Mobil reps and engineers were consulted about pipe construction and possible risks. Possible sources discussed were:
- Underground H20 lines in close proximity to the burning fuel line could cause water to convert to steam.
- Fuel surges through the lines as fuel was being consumed creating hot air pockets. Concerns of secondary line ruptures were discussed and all sectors were warned of the possibility. Mobil crews were sent out to walk the path of the underground lines to investigate the reports. A HM 2-9 portable hi-band radio was given to Mobil reps for communication capabilities.

At 2145 hrs. All water flow was stopped, equipment that could be salvaged from the trailer had been removed and the remaining fuel in the lines continued to burn.
Possible burn times based on amount of fuel remaining in the lines were calculated. Field calculations estimated 13,776 gal./mile of 8” pipe. 12.9 mi of 10” pipe to the E. & 12.5 mi. of 8” pipe to the W. (5280 f/mi) = 349,910 gallons of fuel. Later detailed estimates:
8”= 2.6 gpf 12.5 x 5280 = 66000 ft. 66,000 x 2.6 = 171,600 gallons in 8” pipe
10”= 4 gpf 12.9 x 5280 = 68112 ft. 68,112 x 4 = 272,448 gallons in 10” pipe
approx. 440,048 gallons of fuel available in the pipes based on . Original estimate of 10 plus hrs. of burn time was re-evaluated by Mobil engineers who reported the fire could burn for several days.

At 2225 hrs. Plans to monitor the fire through the night were made by keeping a minimal crew and send the others home to rotate as needed. Mobil reported they were making arrangements for a crew of oilwell firefighters (Williams Co.), to fly in from Texas to extinguish the fire and assist in repairing the leak. Their expected arrival time was between 5 & 7 am. Plans were made to monitor the fire through the night with minimal crews. Once the fire is extinguished, Hazmat Operations would consist of monitoring temperatures on the pipe until it is cooled enough to make repairs (<100 degrees F) and air monitoring for LEL & benzene in the area of repair work

At 0400 hrs. HM 2-9 personnel reported flame temperatures exceeded 1000 degrees F and the pipe (where it entered the ground) was 350 degrees F.
At 0500 hrs. Williams Co. arrived on-scene and prepared to extinguish the fire.
At 0610 hrs Williams Co/FD attacked the fire w/a combination of foam & Dri-chem (purple K). All personnel were warned that re-ignition is possible at any time until the leak was repaired.
At 0612 hrs. the fire appeared to be out. Air monitoring reports were:
East sector: CO = 3, O2 = 21.4, LEL = 0
West sector CO = not reported, O2 = 21.1, LEL = 1
Williams Co. and FD personnel continued to foam to control vapors and prevent reignition.
At 0621 hrs. Fire was reported to be out and incident was placed under control by FD.
Temperature readings of the pipes were between 200-400 degrees F.
Mobil requested benzene air monitoring be performed around Mobil cascade unit. A hot work zone was established by placing stakes and barrier tape around a 50 perimeter of the fire area.
0640 hrs. Air monitoring reports:
South/East sector: CO = 0, O2 = 20.9, LEL = 0
North/West sector CO = 0, O2 = 20.1, LEL = 0
Benzene levels were reported to be 5-10 ppm (w/benzene detector tube) directly over pipes. LEL=1. Foaming operations resumed at incident scene to control vapors. Mobil/Lewis/Williams requested HM 2-9 continue to provide continuous air monitoring until Mobil air monitoring personnel arrived.
A MiniRae PID meter was also used to detect benzene. 50 ppm of benzene was detected 6 ft. from the valve flange. HM Sector Command re-evaluated monitoring/research information due to concern w/breathing protection needs. Research info on Benzene:
NIOSH Guidebook: ST=1ppm, IDLH=500 ppm, UEL=7.87%, LEL=1.2%, SCBAF
Chris Manual: STEL= 75 ppm for 30 min., IDLH = 2000 ppm
Sax Manual: STEL=5 ppm, CL 25 ppm, UEL=8.0%, LEL=1.4%,
Based on the most conservative research recommendations (ie. NIOSH), the 5–10ppm detected w/tubes & 50 ppm w/PID (w/o correction factors or cross indications considered), recommend anyone working directly over or around the leaking flanges wear SCBA’s. Continued monitoring with the PID & tubes indicated 6-20 ppm around work site were detected.
Several resource specialists were contacted to discuss PPE recommendations and evaluate tube accuracy and PID correction factor calculations. Contact #1 (an industrial Environmental Health & Safety professional) agreed with SCBA recommendation, based on the 5 ppm w/tube & 50 ppm w/ PID due to the carcinogenic nature of the benzene.
Contact #2 (a private contract Hazmat Specialist) further evaluated the meter correction factors as such:
The approximate quantity of benzene in Mobil Oil unleaded gasoline as 2%.
The ACGIH TWA of Gasoline is 300PPM; for benzene it is 0.5 PPM.
The response factor for gasoline for the Rae PID is 0.9-1.0. Therefore the concentration of gasoline was about 50PPM, well below the established exposure level.
If we speculate that the 50 PPM reading on the PID was total benzene, the response factor is 0.53 PPM and thus we would have about 25 PPM of benzene.
The TWA of benzene is 0.5 PPM. The assigned protection factor (APF) for an air purifying respirator with organic vapor cartridges is 50. If we multiply the TWA of benzene by the APF of the respirator we get about 25 PPM. That indicates that we can use an air purifying respirator in an atmosphere of 25 PPM of benzene. Since we know that the reading of the PID is not total benzene, we are well below the maximum use concentration for the respirator.
Based on this information, we could down-grade to APR’s but given the hot temperatures that the crews were working in, SCBA’s were a more comfortable way to work and the crews chose to remain in SCBA’s during the repair operations.

At 1030 hrs. DEP arrived w/additional air monitoring equipment (ie. PID’s). 2-9-1 & 2-9-3 were released from the scene. 2-9-2 remained until additional tubes & equipment arrived. Booms were OK and there was no visible runoff.
At 1105 hrs. HM 2-9 was released from the scene and returned to service.

Lessons learned from a Hazmat perspective:

The overall Hazmat operations for this incident went very well and several
good strategies came out of it. The duty officer was on-scene within 15
minutes and all three pieces of apparatus arrived with sufficient personnel
within 25 minutes. Initial information received from county and the fire
department was quick and accurate, allowing us to formulate a response plan
quickly.

Although initially (from a hazmat standpoint) we would not think of this
incident as a major chemical problem, the size of the fire, the threat of
additional explosions, the potential for large quantities of runoff and the
air monitoring needs that arose during the repair phase made this a very long
and involved incident.

Assigning an Operations Chief and splitting the units by placing one vehicle on the north side and one on the south proved to be very efficient setup. We were able to immediately split the fire ground in two and separate operations could quickly be established for
both. The Operations Chief handled the incident specific operations allowing the Chief to concentrate on the overall impact and needs of the incident as it progressed. Having the utility van helped to move additional foam into the fire ground but we had to use a personal sport utility vehicle to shuttle equipment down into the field where the stream was located.

As Chief, one of the best lessons I learned from this incident was the importance of assigning a Documentation Officer to write down events as they happened. By having someone stay right with me noting all transmissions and discussions, it freed me of trying to make notes and allowed me to more thoroughly focus on the communications and operational needs. It paid off even more so later on when I had to sit down, sort through all the paperwork and try to write the incident report. All the information was right there and it was very easy to put it all together. The other advantage to assigning this position is that you have another trained member to discuss options with. It gives you a chance to talk things over, get feedback and other ideas.

Utilizing the command bus was another helpful tool for this event. Having all the command officers together along with company reps and government officials made it much easier to make collective decisions and ensure that all actions were being communicated to each sector. Interaction between all the organizations went very well and having Mobil representative on-scene very early helped tremendously. They were able to give us a lot of valuable information and were able to respond to our needs quickly.

Having accurate Emergency Response Plans available early into the incident was another factor that allowed for quick evaluation of the hazards, risks, and protective actions needed.

Because of the length of this incident and the hot weather conditions, rehab and personnel rotation was very important. There were no reports of heat related problems from any of the emergency service organizations.
This was not the most dangerous incident we have ever responded to but it was certainly the longest. Thanks to all the responders who helped to make this a “good call”.