After investigating for more than a year, the Northwest Clean Air Agency has issued a notice of violation to the Shell Puget Sound Refinery at March’s Point.

This stems from Feb. 20, 2015, when a foul stench settled on La Conner and the Swinomish Reservation because noxious, stinking chemicals were accidently spewed into the atmosphere by the refinery.

“This incident sickened many people in the community, and people felt unsafe in their homes and at work,” said Mark Asmundson, executive director of the Northwest Clean Air Agency.

According to a press release from the agency, there were 67 complaints directly to the agency while the gasses stunk up the community.

In addition, the Swinomish Indian Tribal Community collected 176 written statements and many oral reports from hundreds of people affected by the chemical release.

The Clean Air Agency alleges that the refinery took shortcuts and failed to follow procedures when it shut down and decontaminated a flare system. “Shell’s actions led to a surge of wet, chemical-laden gasses moving through the flare lines and extinguishing the flare flame, allowing the release of unburned chemicals to the atmosphere,” the press release states.

The chemicals rode light winds to the La Conner area, where at about 3:45 p.m., people noticed a horrible odor and hundreds suffered burning eyes, irritated throats and lungs, headaches and other symptoms.

Some made trips to emergency rooms, others took their families out of town and rented hotel rooms for the night.

“With two oil refineries in our backyard, the Swinomish Tribe is extremely concerned that something like this could happen again,” said Swinomish Chairman Brian Cladoosby in a written statement.

Clean Air Agency communications director Katie Skipper said the refinery has 30 days to answer the allegations. Regulators will not begin to consider penalties until after the refinery responds, she said.

Last November the state Department of Labor & Industries fined the refinery $77,000 for workplace violations over the same incident, which it termed an “uncontrolled toxic release.”

L&I determined that toxins including mercaptans, hydrogen sulfide, hydrocarbons and pyrophoric iron where belched out.

On Tuesday Shell Puget Sound Refinery Spokesman Cory Ertel released a statement acknowledging the facility had received notice of the violation allegations on Monday.

“Nothing is more important to us than the safety of our employees and community,” the state ment read.

“We are committed to learn from this incident and remain cooperative with all appropriate agencies to ensure this does not happen again...,” the statement continued. “We do not, however, take lightly the impact to the community and are determined to continue operating in a way that respects our neighbors and maintains their trust.”

“This was a very serious event, and it is right that an investigation is proceeding,” said La Conner Mayor Ramon Hayes. “However, since the event, Shell has been in close communications with the town regarding ongoing maintenance procedures happening at the plant. I feel confident they are taking every precaution to minimize the chance of this happening again.”