Mar 04,2008 00:00
CANBY, Ore. -- Canby firefighters and gas crews initiated an immediate evacuation of a northeast residential neighborhood Monday when they discovered a leak in a natural gas line with circumstances officials called “eerily similar” to those of a Spring 2007 event in which three firefighters were inside the building when it exploded.
Fire crews first dispatched to a location on SE 11th Loop about 10:30 a.m., March 3, only to find “nothing or nobody,” with no homes that matched the address given, a news release stated. 911 Dispatch had been provided an incorrect address by the reporting person, and crews were eventually sent to 1470 NE 11th Street on the opposite side of town after they received the corrected information.
Homes on one side of the residential street were evacuated, electricity to four homes was shut off, and a handicapped occupant and his caregiver were relocated Monday morning when officials determined a natural gas leak was in the “flammable range”.
Northwest Natural Gas reported high levels of gas in the garage and in the front of the home. The flammable range is when concentration levels are between 5 and 15-percent, with only an ignition source needed to burn or explode.
Since the April 2007 explosion, policy dictates that when gas levels reach above 20% of the lower explosive limit (LEL), which is 1% whole gas, the next step is to control ignition sources. In this case, it meant shutting off electricity to four homes, and securing the low voltage phone line.
Another policy change is that firefighters and emergency responders are not allowed to enter the building if levels are above the LEL, and instead must use outside ventilation techniques.
“Today's gas leak presented itself eerily like the explosive situation that occurred a year prior; there had been underground horizontal boring installing fiber optic lines in the area, there were high levels of Natural Gas in the homes garage, and the ground was saturated in Natural Gas. The area was secured and Northwest Natural took the lead on finding the leak, which was in a T-service gas line feeding the home,” fire officials said.