mas gas

(CANBY, Ore.) - It took emergency crews two hours to resolve a natural gas leak today in Canby. This is a community sensitive to this danger after a natural gas explosion last year that happened in a home occupied by Canby firefighters.

During this incident today at at 1470 SE 11th, one entire street-side was evacuated, four homes had electricity shut down, and one handicapped occupant and his caregiver had to relocated.

The leak was originally called in to Clackamas dispatch just before 10:30 AM, but a somewhat confusing name similarity in local roads led to an initial bad location.

Canby Fire Spokesman Troy Buzalsky, says firefighters responding to the location found no homes that matched the address.

Clackamas Communication, the fire district's dispatch service, recontacted the initial 911 caller and corrected the address to 1470 NE 11th, which is on the opposite side of Canby.

Buzalsky says firefighters corrected their response and met up with representatives from Northwest Natural Gas for a situation overview.

"Northwest Natural Gas reported high levels of Natural Gas in the garage of the suspect residence. They also found high levels of Natural Gas in the ground in front of the home."

He explains that natural Gas has a "Flammable Range" of 5% to 15%, which means it can ignite in an atmosphere between 5% and 15%. Mixtures under 5% are too lean to burn, mixtures over 15% too rich to burn.

"If gas mixtures are within their flammable range the only thing needed for a fire or explosion to occur is an ignition source."

Canby Fire experienced just such an event in April of 2007 when a home being ventilated to remove excessive Natural Gas exploded with three firefighters inside. (see: Natural Gas Explosion Injures 4 Canby Firefighters)

"After the gas explosion in Canby, Canby Fire has worked very closely with Northwest Natural Gas to better prepare both the fire service and the gas company for these emergencies. One change in policy is that when firefighters monitor Natural Gas levels above 20% of the lower explosive limit (LEL), which is 1% whole gas, they are to 'Control Ignition Sources,'" he said.

With this draft policy in place, the Incident Commander ordered the electricity to the subject home, and three adjacent properties to be shut off. He also called Canby Telcom to secure the low voltage phone line, further reducing possible ignition sources.

Buzalsky says another example of the policy change is that unless firefighters are faced with an evacuation or rescue, they are not allowed to enter environment above 20% LEL, and must use outside ventilation techniques to clear the potentially explosive gas from inside the building.

"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."

He says 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.

Buzalsky says that most importantly, there was no explosion, no fire, and no long-term inconvenience.