BENICIA (KPIX) – An environmental watchdog claims it caught a polluter on camera in the act of repeatedly discharging a petroleum byproduct illegally into the bay at the Port of Benicia.

The port of Benicia, owned by Amports, mostly exports cars. But it also stores and exports petroleum coke, a byproduct of the oil refining industry. Neighbors have been complaining about breathing toxic dust from ‘petcoke’ for years. Now they say they finally have proof there’s a serious problem.

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Marilyn Bardet is an artist, though most in Benicia where she lives know her as an environmental activist. For years she’s been fighting to get something done about toxic dust in the air from petroleum coke, a refinery byproduct.

It comes by rail from nearby Valero to the port of Benicia where it is stored in silos then transferred to ships.

“We find what looks like black grit, very very fine powder. If that is on our windows, so what’s in our air?” said Bardet.

So, when Bardet saw drone video of what appeared to be a cloud of petcoke dust in the air during a loading operation at the terminal, she felt vindicated.

“Well, there’s evidence. I immediately sent out a letter to everybody I knew, including the mayor, and everybody’s heard me talk about this before,” said Bardet.

“We get out here as often as we can and we see some sort of exposure event almost every time we are out here,” said Cole Burchiel, a field investigator with San Francisco Baykeeper, a watchdog group that patrols the bay on the lookout for polluters.

Using the non-profit’s newest investigative tool, a drone, Burchiel has been gathering evidence of what appear to be recurrent petcoke discharges at the port.

“One of the biggest issues we have been seeing is something called overspray, which is essentially when the loading crane from the facility, as it’s going into the bulk carrier vessels, will spray the petcoke out over the ship and produce this aerial plume that is then deposited into the water next to the ship and throughout the Carquinez Strait,” said Burchiel.

Petcoke dust contains fine particulate matter that, in the air, can cause serious health impacts like asthma and heart disease. The heavy metals in petcoke can also be harmful in the water to fish and birds.

So Baykeeper has filed a notice of intent to file a “citizen suit” against the port for violations of the Clean Water Act.

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“What we are seeing is mishandling of petcoke in the loading operation of these vessels, and as a result not only are we getting airborne contamination, but we are also getting contamination in the water,” said Burchiel.

We reached out to Amports for comment but got no response and an unfriendly welcome.

Valero also never returned our calls. The Bay Area Air Quality Management District allows it to handle 2 million tons of petcoke a year through the terminal.

“It’s the residual of what’s scraped out of the tank if you will, said Ted Nace with Global Energy Monitor, a group of journalists and environmental advocates that researches crude oil supply chains. He says Valero and several other Bay Area refineries have been upgraded to handle heavier crude that produces more petcoke.

US Census data shows Benicia is one of four ports exporting petcoke from the bay this year. And exports for the San Francisco region combined are up, from $73-million in 2020 to almost $101 million just through August of this year. The U.S. also happens to be the biggest exporter of petcoke in the world at $4.6 billion dollars in 2020.

The unintended consequence: More pollution.

Petcoke is dirtier than coal, emitting 5-to-10% more carbon dioxide when burned.

“You see the worst parts of the carbon cycle in petcoke. You see it coming from the worst types of petroleum production and then you see it used in some of the dirtiest utilizations of carbon,” said Nace.

Back in the bay, Marilyn Bardet hopes Baykeeper’s drone video and threat of legal action will finally mobilize Amports to take action.

“I am grateful because it opens up a question even to the air District about what we are doing about petcoke,” said Bardet.

Meanwhile she’s turned from painting pollution to painting nature, an escape to the environment she fights so hard to protect.

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Valero has been cited in the past for emissions of petcoke dust. The Air District tells KPIX 5 it is investigating Baykeeper’s findings. We are still waiting to hear back from the California State Water Resources Control Board.