Health officials issue warning over wastewater fumes in Crockett
CROCKETT - Contra Costa Health Services continues to advise Crockett residents to protect their health due to elevated levels of hydrogen sulfide coming from the Crockett Wastewater Treatment Plant.
Air monitoring data on Monday and Tuesday from the county's Hazardous Materials Program show concentrations of the chemical that can cause headaches, nausea and irritated eyes over long periods.
County health officials said in a statement Wednesday they haven't detected levels of hydrogen sulfide in Crockett's air that would be considered immediately dangerous to public health.
The threshold at which hydrogen sulfide in the air may cause symptoms is .03 parts per million (ppm). The Bay Area Air Quality Management District (BAAQMD) took a one-hour average reading of .036 ppm near the plant last Friday, prompting the health advisory from the county.
A team on Tuesday collected a one-hour average reading of .045 ppm near Port and Ceres streets, directly east of Interstate Highway 80 from the plant.
County officials say commercially available carbon air filters, also known as activated charcoal air filters, are effective at reducing levels of hydrogen sulfide indoors. Masking is not effective protection.
The elevated levels of hydrogen sulfide are the result of a weeks-long operational issue at the plant at 1801 Dowrelio Road, which processes sewage from the community and wastewater from the C&H Sugar refinery. C&H owns the property and operates the facility through contractor Inframark.
Inframark said in a statement Wednesday it will complete cleaning of more than 1,300 air diffusers in one of three wastewater treatment reactors by the end of Wednesday. The diffusers provide oxygen needed by microorganisms in the wastewater that break down sewage.
The reactor will be placed back into operation Wednesday afternoon with these optimized diffusers and additional microorganisms. The air diffusers in the other two wastewater treatment reactors will be cleaned next.
Inframark is also upgrading the blowers that supply oxygen to the diffusers with new, larger motors to add reliability and further increase aeration.
Inframark said it expects the odor to cease within seven to 10 days as microorganisms have time to digest. Residents should notice odors dissipating sooner.
The county recommends people experiencing minor symptoms to stay indoors with windows and doors closed. People experiencing serious or persistent symptoms should contact their health provider.
Levels in the air may vary based on location, weather and proximity to the plant. Smelling hydrogen sulfide (a rotten-egg or sewage odor) is not an indicator that concentrations in the air are high enough to pose a health risk.
The Contra Costa County Office of Emergency Services and the Hazardous Materials Program provided 40 indoor air filters to John Swett High and Carquinez Middle schools. On Tuesday, hazardous materials crews measured a one-hour average reading of .0031 ppm outdoors at John Swett High, and .0015 ppm outdoors at Carquinez Middle.
The county said it will release updated air quality data as it becomes available. For information and updates about the operational problem causing the release of hydrogen sulfide in the community, contact C&H at (510) 787-2121 or communications@chsugar.com.
For information about regulatory action related to the plant, people can contact the Bay Area Air Quality Management District at (415) 749-4647.
The Crockett Improvement Association will host a public meeting at 7 p.m. Thursday regarding the situation at the plant at the Crockett Community Center, 850 Pomona Ave.
