Your nose knows that a rotten egg smell reeked up San Francisco and the greater Bay Area for two days in late December of 2016, and that the prime suspect was the Chevron refinery in Richmond who engaged in some “flaring”, or burning off of unrefined fuels to relieve pressure on gas lines. Chevron initially did not report the flaring incident, then admitted to the flaring but insisted that it had nothing to do with the outbreak of a sulphur-like smell. But a regional air board has investigated the matter and determined that it was definitely Chevron who cut the cheese.

KQED reports that the Bay Area Air Quality Management District has completed their investigation into the odiferous outbreak, and has concluded that the Chevron refinery was indeed the culprit. According to KRON 4, there were at least 69 (heh!) reports of the rotten egg smell submitted to PG&E on December 28 and 29.

The Air Quality Management District Issued four violations to the Chevron refinery on Tuesday. ABC 7 describes two of the violations as “excess levels of hydrogen sulfide detected by ground-level monitoring equipment,” whereas the other two violations are for creating a public nuisance. The district’s findings are based on analysis of air quality monitors, data from a wastewater plant near the refinery. and weather patterns from the dates in question.

“We will be seeking the maximum penalties available to us for this incident," the district’s CEO Jack Broadbent said in a statement. “In addition to being cited for this incident, Chevron will be required to make changes to their operations to ensure it doesn’t happen again.”

But hold on to the clothespin on your nose — Chevron disputes these findings and continues to basically deny guilt. “This is a complex issue,” Chevron spokesperson Leah Casey said in an email to KQED. “But given the small amount of H2S (hydrogen sulfide) released, the 11-mile distance across the Bay, and the wide geography of the odor complaints, we believe it is unlikely that the flaring was the source of the odors.”

Keep in mind that a separate KQED report from early January found that during the late December dates in question, toxic gas levels near the Chevron refinery exceeded local air regulation restrictions and were “so intense in one instance that it maxed out the company’s pollution monitoring equipment."

This issuing of citations is not the final step in the smell-shaming process. While district officials insist they will seek the maximum possible fine, that fine will actually be determined through a settlement process with Chevron. The Chronicle reports that “the violations come with hefty fines — which can run thousands of dollars for severe violations”, though thousands of dollars does not sound particularly “hefty” to a multinational energy corporation whose current market capitalization is about $199 billion.

Related: San Francisco Beset By Mystery Stench