What to know about flaring at the Chevron refinery

The sky over the Chevron Richmond refinery was choked with thick black smoke for more than seven hours on Nov. 27, 2023. A relay in the electrical system at the refinery’s hydrogen plant had self-activated just before 3:30 p.m., causing a power failure and a serious flaring episode that continued past 11 p.m.

When it comes to flaring — or the intentional burning of dangerous gasses by industrial facilities like refineries — the incident last year was exceptional in its duration and in the amount of air pollution it produced. It alarmed residents, garnered dozens of complaints to the air district, caught the attention of news outlets, and elicited statements from city and state elected officials. 

But it wasn’t the first or last large flaring incident at the refinery to scare people in Richmond, where residents have been living with it for years. And according to public records compiled by Richmondside, flaring occurs more often — although at smaller and less visible volumes — than many residents might suspect. 

Since launching Richmondside in June, readers have messaged our newsroom asking us to explain what flaring is, to report on how often it occurs, and look into how harmful it is for local residents. So, as part of our investigative series into air pollution in Richmond, we set out to answer these questions, drawing on previous reporting, local interviews and publicly available data. 

What is flaring?

In simple terms, flaring refers to the release and burning of combustible hydrocarbon gases produced during the process of oil refining. The tall stacks and ignition devices at refineries that are used for this are called flares. Flaring is done intentionally to prevent venting, or the direct release of methane into the atmosphere, in order to reduce the risk of it harming people who breathe it.

Here’s how the Bay Area Air Quality Management District explains it:

“Flares are found at all Bay Area refineries and are important safety devices. Flares burn refinery process gasses that would otherwise be directly released to the atmosphere and are designed to protect the public, refinery workers and refinery equipment.”

Chevron also states on its website that flaring is essential for safety at the refinery and is done “to minimize the potential impact to surrounding neighborhoods.”

Besides oil refining, flaring is used in sewage processing, rocket engine testing, at nuclear power plants and in other industrial activities, according to the U.S. Environmental Protection Agency. 

Both flaring and venting at Chevron Richmond and other refineries are allowed under Bay Area Air Quality Management District rules, but only up to a point.

The air district requires local refineries to report all of their flaring events, big and small. But when the flaring emissions exceed certain thresholds — 500,000 standard cubic feet of gas, or more than 500 pounds of sulfur dioxide in one calendar day, for example — they are required to file a more in-depth “causal report” to the district explaining the reasons for the flaring. When the limits are exceeded, refineries can be slapped with fines that are collected by the air district.

Between 2019 and 2022, there were 161 reported flaring events that exceeded air district emission limits at the five main Bay Area fuel refineries, four of which are in Contra Costa, according to a 2023 air district report. More than half of the flaring incidents were reported by Chevron in Richmond, and half of those were associated with one particular hydrogen processing facility that went online at the refinery in 2018.

Flaring at Chevron Richmond happens daily, but usually on a small scale

While last November’s large flaring incident captured the public’s attention, Chevron has reported flaring episodes at its Richmond refinery almost every day for nearly six years, according to Bay Area air district records compiled by Richmondside. 

A vast majority of the flaring events don’t exceed the emissions limits that would require Chevron to file a more in-depth causal report with the air district. But the frequency of flaring at Chevron Richmond — the majority of which has occurred at its new hydrogen plant — sets it apart from other Bay Area refineries where flaring reports have been more intermittent.

But just how significant are these smaller flaring incidents? 

Using last November’s air district reports as an example, we can see that the smaller, but repetitive flaring at Chevron that month produced more emissions cumulatively than the one larger incident that grabbed headlines: The Nov. 27 event was responsible for just 7% of all emissions caused by flaring and venting that month. (The large single flaring event was, however, responsible for a majority of the released sulfur dioxide, a chemical harmful to children with asthma.)

Flaring and venting happens every day at the Chevron refinery because it’s built into the system and unavoidable when the hydrogen plant is turned on and off, according to the company.

After one significant flaring event at Chevron in 2019 lasted for nearly 14 hours, releasing about 1,400 pounds of methane into the air, Chevron reported that the flare was a result of shutting down its hydrogen plant for planned maintenance. In its report, the company told the air district that “flaring cannot be prevented during plant shutdown due to facility and relief system design.”

A Flare Minimization Plan submitted by Chevron to the air district in 2023 attributed “a substantial portion” of the refinery’s flaring to planned maintenance. 

Chevron has also reported several flaring events due to extreme weather events, such as high temperatures, which are worsening and occurring more frequently due to climate change.

A three-hour flaring episode occurred on Sept. 2, 2017, when the daytime high in Richmond reached 107 degrees Fahrenheit and an overhead fan at the refinery suffered an internal electrical failure and shut down.

When an atmospheric river dumped rain on the Bay Area in late October 2021, there were several malfunctions at the refinery, which led to three days of flaring. Those events resulted in 71 citations from the air district. 

Over the past four years, Chevron has averaged two sizable flaring events per month, a higher frequency than any other Bay Area refinery, except for last year, when both Chevron and Marathon Petroleum in Martinez reported 25 such events. 

Most of the flaring is at Chevron’s new hydrogen plant

Chevron’s hydrogen plant is responsible for most of the flaring emissions at the Richmond refinery. The plant was part of a modernization project that replaced old equipment from the1960s with newer technologies, which Chevron said would allow the refinery to handle more crude oil while still meeting environmental and safety standards.

During the planning phase, Chevron told state regulators in 2008 that the project wouldn’t have a significant impact on the environment and would be cleaner and safer than the previous hydrogen production unit. Chevron assured the air district that there would be “no routine flaring operations” at the new plant.

But the project experienced more than a decade of starts and stops due in part to questions and concerns over its potential environmental impact.

The work was halted by a judge in 2009, halfway through completion, after local activists sued the city for permitting the project before a proper environmental review had taken place. The project came under scrutiny again in 2014, when the California Department of Justice — headed by then-Attorney General Kamala Harris — commented that further evaluation was needed to determine whether the changes could result in “an increase in flaring and/or an increase in emissions when flaring occurs” due to the presence of “higher sulfur crude.” The DOJ also said the impact report lacked detail on how the project would mitigate air pollution. 

Ultimately, a final environmental review published in June 2014 determined that the modernization would not increase flaring at the refinery, citing Chevron reports that flaring only accounts for “a very small portion” of the refinery’s overall emissions, including just 0.1% of the particulate matter that can be inhaled and damage a person’s heart and lungs. A Chevron engineer wrote that the company had “near [sic] eliminated” flaring events at the time. 

The new hydrogen plant went into use in November 2018. By the following year, the refinery had reported 38 significant flaring events, more than all four other Bay Area refineries combined, contributing to the highest number of significant flaring events in one year in the Bay Area since 2006. 

Chevron spokesperson Caitlin Powell told Richmondside in an email that the company’s operation of the hydrogen plant is in compliance with the U.S. Environmental Protection Agency and Bay Area air district requirements for methane emissions. 

“Compared to other process flares, emissions from the Hydrogen Plant flare are very low because it combusts gas that is mostly hydrogen and natural gas,” she wrote.

Despite the company’s assurances, the frequency of the flaring activity at Chevron is a source of concern for some residents who live nearby.

“Sometimes you go out late at night and wonder what the hell is going on,” said Madeline Marrow, who lives in Atchison Village. “It looks like a fire or something over there, you know, when people are sleeping and don't see it that much.”

Marrow, who sits on the neighborhood’s advisory board, said she and some other Atchison Village residents don’t believe Chevron or the air district when they say that some amount of flaring is safe. 

“We’re saying no, that flaring is letting off bad gases,” she said.

Is flaring harmful?

Just as  with many types of environmental pollution, it is difficult if not impossible to draw a straight line between a specific source like flaring emissions and a personal health condition such as asthma, cancer or cardiovascular disease. But we do know that exposure to fossil-fuel emissions can lead to these health problems and others, and that people in Richmond have higher rates of asthma and related illnesses than many other parts of the state.

In Richmond, the Chevron refinery is the biggest local producer of fine particulate matter, which health experts say is the most harmful form of air pollution because it can slip through the body’s natural defense mechanisms and embed deep into tissue. Short-term exposure to this type of pollution can affect the lungs, triggering asthma attacks or develop into bronchitis. Longer exposure can damage children’s lungs, lead to heart disease, and shorten a person’s lifespan. 

Beside fine particulate matter, flaring at refineries in the Bay Area can release a slew of chemicals known to have hazardous health effects, including respiratory system-damaging chemicals like ozone, sulfide hydrogen, dioxide nitrogen, and sulfur dioxide. Flaring can also release benzene, toluene, and xylene, which are poisonous and carcinogenic and can affect a person’s nervous system, even at low densities.

Carbon dioxide and methane, which are produced by flaring and venting, respectively, are also main drivers of global climate change.

The International Energy Agency (IEA), an organization working on sustainable energy solutions, has identified flaring as a “major source” of carbon dioxide emissions, methane and black soot worldwide and called it “an extraordinary waste of money, in addition to its negative impacts on climate change and human health.” 

To reduce the environmental and health effects of flaring, the IEA recommends regulators eliminate all non-emergency flaring and minimize the amount of flaring now and in the future. 

What is being done to reduce flaring?

In 2005, the Bay Area’s air district adopted a rule requiring refineries to reduce the frequency and magnitude of their flaring and submit plans to the district that spell out how they plan to do that. The following year, the district prohibited flaring altogether unless it is in accordance with an approved plan or “necessary to prevent an accident, hazard or release of vent gas directly to the atmosphere.” 

In an email to Richmondside, Chevron spokesperson Caitlin Powell said that while some increased flaring was anticipated when the new hydrogen plant was brought online, the amount of flaring that occurred there in 2019 was a “departure” from the refinery’s past performance.

Since then, Powell said Chevron has invested $30 million into improving the hydrogen plant’s performance, resulting in an estimated 85% reduction in flare gas volume. She cited air district data that shows Chevron had a lower volume of vent gas flared than other Bay Area refineries combined in 16 of the last 20 years.

Particulate matter emissions at the refinery have also dropped 36% since the new hydrogen plant has been in operation, according to Powell.

Still, among the five main Bay Area refineries, Chevron Richmond has flared the largest volume of gas since 2018, followed by the Martinez Refining Company, according to air district data.

“We remain focused on reducing flaring and have committed dedicated resources to identifying and addressing areas that can improve flaring performance,” Powell said, including improvements in flare monitoring, operator training on flare reduction, an assessment of previous flaring events, and evaluating how to make refinery equipment more reliable.

Chevron also outlined several ongoing efforts to reduce flaring in a 2023 report, including the formation of a team that meets “periodically to address the refinery's flare minimization issues.” 

Reviewing lessons learned over a five-year period, Chevron determined in the report that “the greatest potential for further cost-effective reductions in flaring is to update and improve existing operations and maintenance procedures.” 

Penalizing companies for violations is one way the air district can wield its regulatory power. In the Bay Area, Chevron stands out for the number of violations it’s been issued and the amount in penalties it’s paid out in recent years.

Chevron was issued with nearly 500 violations by the air district between 2019 and 2022, the majority for operational violations that resulted in flaring, according to the district’s Path to Clean Air report in March 2024. The commission that authored the report expressed concern over a lack of accountability at Chevron with respect to compliance. Nearly 80% of the violation notices issued by the air district in the Richmond-San Pablo area between 2019 and 2021 went to Chevron.

Earlier this year, Chevron agreed to pay $20 million to settle 678 violations with the air district from 2019 and ending in June 2023, the district’s largest settlement to date.

Greg Nudd, deputy executive officer of science and policy at the air district, said this type of enforcement is key to reducing pollution because the settlement money paid by polluters has an opportunity to go directly to the communities most impacted.

For example, the latest $20 million settlement agreement with the air district stipulates the money will be spent on “projects aimed at reducing [particulate matter] exposures in the communities impacted by the refinery.”

“The next step in that process would be identifying a publicly informed process to get that money out the door and start making a real difference in the community,” said Nudd.

Elsewhere, two of the five Bay Area refineries — the Phillips 66 refinery in Rodeo and the Marathon refinery in Martinez — announced last October that they were stopping oil refining altogether and converting their facilities to processing plant-based diesel fuels.

Colorado banned routine flaring in 2021 — something environmental activists in Richmond have also called for — making it the first and only state to do so. 

Oil production continues to rise globally, according to the World Bank, but incidents of flaring are on the decline. 

Correction: An older version of this article incorrectly identified the PBF refinery in Martinez as one of the two facilities converting to plant-based fuels. It was in fact the Marathon refinery.