Crockett health advisory lifted after air readings no longer detect hydrogen sulfide

CROCKETT – Contra Costa Health (CCH) lifted a health advisory on Monday in Crockett after air readings taken during the previous two days no longer detected hydrogen sulfide in the air coming from the Crockett Wastewater Treatment Plant, Contra Costa Health Services said.  

Though the advisory has been lifted, officials said they will still be monitoring the area.  

One-hour average readings at three Crockett locations came back negative for hydrogen sulfide– John Swett High School, Carquinez Middle School and at Port and Ceres streets.   

The hydrogen sulfide emission was due to a weeks-long issue at the treatment plant, which is owned by the C&H Sugar refinery and operated via contractor Inframark.  

Inframark said the blowers that supply oxygen to the treatment reactors overheated during September’s record-breaking heatwave.

People who live and work in Crockett expressed their frustrations last week over the smell and the problems its caused for nearly two months, comparing the stench to everything from rotten eggs and an outhouse to garbage, sewage and fish.

The advisory first went out on Oct. 7. Workers at the plant have cleaned more than 1,300 air diffusers in the plant’s three wastewater treatment reactors throughout the week in an effort to reduce emissions of the chemical.  

Contra Costa Health Services initially issued a health advisory for Crockett residents after air monitoring by the Bay Area Air Quality Management District found a one-hour average level of hydrogen sulfide of .036 parts per million. 

According to CCHS, symptoms of hydrogen sulfide exposure, including headaches, nausea and eye irritation may begin to show at .03 ppm.