Cause may have been a Phillips refinery ‘upset’
FERNDALE —  Students at Horizon Middle and Cascadia, Skyline and Eagleridge elementary schools, all within a mile of each other near Thornton Road, reported a strange odor at about noon on June 1, according to the Ferndale School District.
Staff and students also reported feeling sick, with symptoms of burning eyes and coughing. Students were sheltered in place while the cause of the odor was investigated.
As a safety precaution, Horizon and Eagleridge students were transported to Ferndale High School before dismissal for the day. Buses taking students home ran late into the afternoon. 
The Northwest Clean Air Agency responded to the reports of the strong odor after receiving phone calls from residents starting around 1:30 p.m. One caller said the source appeared to be the Phillips 66 refinery at 3901 Unick Rd., about two miles southwest of the schools. 
Officials from Phillips 66 told a NWCAA inspector that an “upset,” or operational problem, in the refining process caused a strong sulfur odor on site, and that it dissipated by mid-afternoon.
“There could be any number of causes [for the upset] during the operation of large, complex industrial processes,” said Seth Preston, air agency representative. “In this case, we are working with Phillips 66 to determine what exactly happened and the cause of the problem.”
Data from the National Oceanic and Atmospheric Administration showed that winds were blowing in the direction of the schools at the time of the Thursday refinery upset, he said.
Although there is no direct link, Preston said the reactions of students and others in the area were consistent with the strong odors reported at the refinery. The NWCAA is working with Phillips to determine the cause, he said.
Responding agencies on site, including a NWCAA inspector, could not locate or verify an exact source of the odor. 
“At this time, the authorities have checked our school buildings ... and have determined they are safe for occupancy,” the school district said on its website by 4:18 p.m. Thursday. “We have not been informed what the cause of the odor was determined to be. Authorities will be investigating the cause in the days to come.”
School was held as normal on Friday.