Birch Bay residents complain of strong odor near bp Cherry Point refinery

More than 70 complaints of an irritating odor coming from the bp Cherry Point refinery were reported to the Northwest Clean Air Agency (NWCAA) over the weekend, which the government agency said was due in part to incomplete burning of hydrocarbon gases at the refinery.

NWCAA contacted the refinery and sent staff to inspect on March 17 after receiving multiple complaints of a “strong burning oil” smell from addresses in Ferndale and Birch Bay that were within roughly five miles of Washington’s largest oil refinery.

Seth Preston, NWCAA communications program manager, said the smells occurred while the facility was in the process of shutting down a coker unit for routine maintenance. During the shut-down, gases in the coker chamber containing odorous hydrocarbons were not properly burned off before being released into the atmosphere, Preston said.

Coker units convert heavier, lower value residual oil residues remaining after refining petroleum and convert it into more valuable products such as naphtha or diesel.

“In this case, the flare may not have been burning efficiently, which likely contributed to the odor,” Preston wrote in an email to The Northern Light.

Refinery staff were able to adjust the flare and reduce the amount of gas being released, but another tank used in the coking process was also improperly venting gases into the atmosphere, which may have also contributed to the smell, Preston wrote.

NWCAA did not have any details on the specific chemicals or the amount released, but Preston did write that refinery coker units can contain sulfur compounds such as mercaptans, which are “readily detectable by most people at very low concentrations.”

NWCAA is continuing its investigation into the gas release. 

Cesar Rodriguez, a spokesperson for bp, wrote to The Northern Light in an email that the company is still working to identify what specifically caused the leak during routine maintenance.  Rodriguez said workers conducted air monitoring tests around the perimeter of the refinery and surrounding areas for three days after the incident, and found "no elevated levels of hydrocarbon compounds that could pose a risk to public health."

"We regret any disrution this may have caused our neigbors," Rodriguez wrote. "We value the community's patience as our team works diligently to identify the cuase and prevent future incidents."

This article was updated at 12:05 p.m. on March 21 with a statement from bp.