When a major malfunction caused Valero's Benicia refinery to spew out pollution last month, leading city officials to warn residents with respiratory issues to stay indoors, the agency that regulates air in the Bay Area had to send a van to monitor the situation.
Valero's March Pollution Release Exposes Weaknesses in Benicia's Air Monitoring System
That’s because there is no stationary air monitoring device in Benicia's residential areas, even though the city is home to one of the largest refineries in California.
The Bay Area Air Quality Management District took a series of air samples, but none during the height of the emergency that Sunday morning of March 24, when a plume of black smoke filled the air for hours, convincing officials to issue a health advisory.
Several people called 911 to report breathing problems at the time of the refinery breakdown. The air district said it received about a dozen complaints.
There's also no evidence that Valero monitored the air in those residential areas during the time period when the releases were most extreme.
The refinery problems sent soot into the air and followed two weeks of more minor releases that regulators thought were tapering off. The plume that morning eventually led Valero to shut down a large part of its facility, a move that has contributed to the increase in the cost of gas statewide in recent weeks.
Several public agencies and companies conducted air monitoring work to measure for a variety of chemicals that may have spewed from the refinery's stacks.
Some local officials say those tests may prove that, for the most part, elevated levels of particulate matter and toxic gases did not waft into nearby residential neighborhoods.
Indeed, it looks so far like the pollution was not as bad as the extreme release of toxic sulfur dioxide that accompanied Valero's May 2017 power outage, one of the Bay Area's worst refinery accidents in years.
But Benicia's mayor, along with a leading air quality expert and two local environmentalists, say these most recent releases confirm that the small North Bay city needs a more robust and coordinated strategy to measure what gushes out of its largest employer.
"It seems that right now, if there's an incident, what happens is folks kind of drive around and see if they can catch the plume," said Anthony Wexler, director of the Air Quality Research Center at UC Davis.
Valero's data:"Questionable until further notice"
Three government agencies are investigating the most recent malfunction at the Valero refinery. The focus of at least one of those investigations centers on two key components at the refinery that experienced problems, allowing petroleum coke, an oil processing residue, to escape.
The refinery malfunctions began on March 11. Two days later, Valero hired an Arkansas-based consulting firm, the Center for Toxicology and Environmental Health (CTEH), to take air samples around the refinery to test for carbon monoxide, nitrogen oxide, sulfur dioxide and particulate matter.
During eight consecutive days of testing, the firm detected more than a thousand small readings for particulate matter less than 10 microns wide and 2.5 microns wide, known as PM 10 and PM 2.5, respectively.
That work ended when regulators and Valero believed the releases were coming to an end. On March 23, petroleum coke began again belching from the refinery's stacks.
But the CTEH did not restart air sampling until the following afternoon, well after the health advisory had ended and officials told the public the air was OK.
Hollin Kretzmann, an attorney with the Oakland-based Center for Biological Diversity, said it's concerning that the CTEH data does not include the time period during the height of the releases.
"There is a huge gap of data that we are missing," Kretzmann said.
A CTEH spokesman referred questions to Valero, which declined to answer questions about the firm’s work.
Valero runs fence line monitors around the refinery, but the site that publishes its data includes a warning that all of its measurements should be considered "questionable until further notice" because several of its parts require adjustments before they can produce reliable and accurate data.
Air district monitoring efforts
On March 24 and 25, BAAQMD inspectors drove the agency's mobile monitoring van near the refinery to measure for hydrogen sulfide, sulfur dioxide and carbon monoxide, as well as benzene, toluene and butadiene.
The agency compared those concentrations for acute, chronic and work-time exposure to state health standards, according to Eric Stevenson, the district's director of meteorology and measurements
"What we saw in these results was nothing above those levels," Stevenson said. "That being said, we did them on Sunday after a lot of the worst visual impacts were detected.”
Stevenson said the district did not collect air monitoring data when the health advisory was in effect in order to protect the health of its staff and because county officials did not request it.
"When the health department declares a shelter in place, we do our best to provide any information that they request. They didn't request any information from us prior to that shelter in place," Stevenson said.
Solano County spokesman Matthew Davis confirmed that the county did not request tests from the air district before it issued the health advisory.
‘"All of the air readings up to that point, during and afterwards, were 'good' to 'moderate' and at no time did the county or CTEH results show 'unhealthy' levels for sensitive individuals or the general public," Davis said.
Elevated particulate levels
However, an air monitoring log from the Benicia Fire Department shows six occurrences when particulate readings were elevated in the early morning hours before the advisory. Fire crews did not take any samples during the hours-long health advisory.
"The fire department's monitoring shows particulate matter pollution repeatedly spiked to very high levels, far higher than what would be considered safe for daily air quality," Kretzmann said. "It raises big concerns for vulnerable people, like kids with asthma."
The fire department's log also includes several instances in which crews noted moderate to strong petroleum byproduct odors.
"This is concerning since those could be toxic," said Wexler, the UC Davis air quality expert.
By the time Solano County inspectors restarted tests that morning, at 9:45 a.m., the particulate levels had dropped.
The county also tested areas in the refinery on one day to determine whether high levels of heavy metals were in the petroleum coke dust coming from the stacks.
Those tests revealed that the releases did not include elevated levels of heavy metals, according to Jag Sahota, the county's environmental health manager.
Calls for change
"You can't fix what you don't know," Benicia Mayor Elizabeth Patterson said in an interview on Monday.
Patterson said the city needs a stronger air monitoring program, money to run it and expertise to understand it, similar to the one in Richmond, where Chevron's refinery is located. A program there provides air quality readings from monitors in three neighborhoods.
"It's not helpful if you don't know the full extent of the public impact," said Patterson. "If you don't have the personnel and you don't have the funds and you don't have a clear path of information, you don't know what's going on. You can't take measures to protect public health and safety.”
"We really need to surround the plant with monitors in the neighborhoods where people are living and breathing," he said. "If the facility can't get control of its situation, it should incur some costs to protect the people who live in the region."
Andres Soto, a Benicia resident and organizer for Communities for a Better Environment, said the city has gone too long without an efficient and robust air monitoring program.
"We need to have a very comprehensive monitoring system that is looking at both the greenhouse gases as well as the particulate matter," Soto said. "We needed to do that 10 years ago. It's beyond critical.”
Kretzmann, from the Center for Biological Diversity, said the refinery and air district do not have a plan in place to capture the most critical data when pollution threatens Benicia residents.
"There's no telling what information we're missing, and the community still doesn't know the true extent of danger it’s facing," he said. "The city needs a system that can accurately and comprehensively measure air pollution when dangerous events occur.”
More monitoring on the horizon
The air district said it’s planning to add monitoring stations to areas near all five of the Bay Area's refineries.
"These stations will be sited to help evaluate and track refinery emission impacts in the surrounding communities," said air district spokesman Ralph Borrmann, adding that the agency is "identifying and attempting to secure suitable space for the site in Benicia."
Valero also plans to help fund work on community monitoring devices, as part of a 2003 settlement with a local environmental group. That group, called the Good Neighbor Steering Committee, is planning to hire staff to run a community air monitoring device in the city’s northwest corner.
That might ease the community's concern but not lead to the best data, said Dr. Bela Matyas, Solano County's health officer.
“More monitors would clearly give more refined information," Matyas said. "But in places where that's been done, that does not yield more accurate estimates of risk over the long term over that area."
During major incidents, like Valero's recent malfunction, he added, mobile air monitoring is still necessary to capture data that a stationary device would not be able to collect.