Nov. 2022 Martinez Refinery Release Did Not Increase Risk of Exposure to Hazardous Metals in Local Soil

On November 24-25, 2022, the Martinez Refining Company (MRC) released spent catalyst into the surrounding community from a Fluid Catalytic Cracker Unit.  After several months of research and soil sampling, a toxicologist hired by Contra Costa Health has determined that the November 2022 catalyst dust release did not increase risk to public health from exposure to hazardous metals in the soil.


The toxicologist came to this conclusion after metals detected in soil samples collected in the area, including samples from Benicia, did not appear in similar ratios or quantities to spent-catalyst dust samples collected shortly after the accident MRC in November 2022. Metals detected in the soil samples were also within an expected range of levels typically found in the state. Soil sampling sites were chosen using a plume-model map developed by the Bay Area Air Quality Management District.


MRC remains under investigation by the Contra Costa District Attorney for failing to notify authorities when a process upset released 20 to 24 tons of waste into the air, covering nearby neighborhoods in a dust that contained metals.


An oversight committee, which includes Benicia Fire Chief Josh Chadwick, was appointed by the Contra Costa County Board of Supervisors to investigate whether the release increased risk of health problems in the community due to environmental contamination and is also overseeing an independent community investigation of the cause of the release.


The root cause of the November hazardous materials release – and how a similar accident can be prevented in the future – remains under investigation by Contra Costa County and the oversight committee.


For more information, visit the MRC oversight webpage.