Authorities began taking soil samples from over 12 sites, including in Benicia, possibly impacted by the November Martinez refinery release.
Patch Staff
BENICIA, CA — A toxicologist hired by Contra Costa County began collecting samples Thursday of soil at several locations, including in Benicia, that may have been exposed to metal-laden “spent catalyst” released by the Martinez Refining Company into the surrounding community last Thanksgiving.
Soil samples are being taken from more than a dozen sites exposed to a 20- to 24-ton plume of dust in an area that stretches from the refinery in Martinez into Benicia and parts of Hercules, Alhambra Valley, Franklin Canyon and El Sobrante.
Collected samples will be sent to a lab to analyze for concentrations of metals associated with the catalyst that may pose risks to human health through skin contact, inhalation or from consuming produce grown in the contaminated soil.
“We know the community is eager to find out what’s in the soil in their yards and whether they should be concerned for their health,” said Contra Costa County Supervisor Federal Glover, whose district includes the refinery, which is owned by PBF Energy Inc. “The soil testing will help provide residents with answers to those questions.”
The sampling plan was based in part on a plume model map created by the Bay Area Air Quality Management District that showed where the spent-catalyst dust likely traveled from the refinery on Marina Vista Road. The plan was reviewed and approved April 27 by the MRC Oversight Committee, which includes seven community residents.
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The soil sampling and risk assessment are being done for the County by TRC, a Concord-based environmental consulting firm. The risk assessment will also compare levels of metals found in the sampled soil against background levels taken from published academic and regulatory sources.
The refinery accidentally released up to 24 tons of metal-laden spent catalyst dust Nov. 24-25 into the surrounding community. Officials said the refinery failed to notify the county about the incident, which is required by local policy. Instead, county officials said they learned about the incident nearly two days later from a social media post.
Initial wipe samples of the spent-catalyst dust taken from surfaces in neighborhoods around the refinery in the days after the accident showed elevated levels of certain metals, such as aluminum, barium, chromium, nickel, vanadium, and zinc.
Visual observations of dust were recorded at schools, the Amtrak station and the health center, among other locations, according to the Bay Area Air Quality Management District. Dust was mostly observed west of the refinery, and winds were light and toward the west, southwest or northwest. The observed dust was consistent with the site of the release and measured winds, the air district said.
The most acute health risk was at the time of the incident when people could have breathed in the dust and caused respiratory distress, according to county health officials. Questions have persisted about possible long-term health impacts, particularly from food grown in potentially contaminated soil exposed to the spent catalyst.
In March, with spring and gardening season arriving, the County’s health officer issued an advisory cautioning residents not to eat food grown in potentially contaminated soil until environmental testing could be completed.
Lab results of the soil samples taken this week are expected in late May or early June.
With a large amount of rain since the event, the catalyst material has likely moved since the initial fallout, the air district said. The soil sampling aims to determine how much catalyst material is currently in the soil.
"Residents affected by this release deserve to know if there is any health risk," said John Goia, chair of the Board of Supervisors and member of the Bay Area Air Quality Management District Board of Directors. "Contra Costa Health is working as quickly as possible to ensure that accurate information reaches the public about this issue."
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