County says relocated Carson residents should prepare to return home, but some say the Dominguez Channel is still making them sick

The thousands of residents who have been temporarily relocated into hotels to escape the foul-smelling hydrogen sulfide gas coming from the Dominguez Channel should prepare to return home as gas levels continue to drop, officials announced in a county town hall Wednesday night.

Some residents, however, said they’re still experiencing ill health from the gas and are not ready to return home.

Los Angeles Public County Health Officer Dr. Muntu Davis said that because the hydrogen sulfide gas levels are dropping, “residents who have temporarily relocated should begin to take steps now to prepare for returning home.”

Davis recommends that residents:

  • Return home and check for foul odors inside
  • Air out the residence for at least two hours, if needed
  • Improve airflow before returning by running an HVAC system or HEPA-certified air purifier for at least 30 minutes
  • Monitor health (including pets) and seek medical attention if necessary

Purchases of certified air purifiers or filters remain reimbursable.

Despite the progress the county and partnering agencies have made, many Carson residents said they are not ready to move back as they are still suffering ill health from the exposure to hydrogen sulfide whenever they visit their homes.

Residents say that once they return to their home, while they can’t smell the foul smell of the gas, they still get the same symptoms, including headaches; eye, nose and throat irritation; sneezing; dizziness; insomnia; nausea and even vomiting.

The Dominguez Channel near the 405 Freeway exit on South Avalon Boulevard and East Dominguez Street on Thursday, Oct. 14, 2021. Photo by Crystal Niebla.

Carson resident Gabriel Reyes, 38, and his wife and five kids relocated to a hotel in Long Beach in the middle of October. While he wishes to return to his four-bedroom home, he doesn’t think it’s safe yet.

After work, he visits his home for a few hours to do chores. But on Sunday, after he did yard work and returned to his hotel, he grew so sick, vomiting even, that he had to miss work the next day.

“I’m not ready to go back,” Reyes said. He also said he’s concerned for the health of his kids, two of them infants. For now, his hotel has extended their stay to Nov. 19.

Erica Terrell, a 33-year-old mother of a newborn, visited her Carson home on Saturday and began to get headaches and nausea. Terrell, who has an air purifier inside of her two-bedroom apartment, said she then called the South Coast Air Quality Management District to report her symptoms even though she didn’t smell anything foul.

She said she was told that her symptoms must have been caused by something else. Many other residents, she said, are going through nearly identical experiences.

“I felt like I was being gaslit at this moment,” Terrell said.

Despite Davis repeatedly saying that he doesn’t believe the current levels will cause long-term health effects, both Reyes and Terrell are fearful for their health because they are still experiencing symptoms when visiting their homes. They suspect the odor neutralizer the county used has been using worked to alleviate the smell but not the effects of the hydrogen sulfide exposure.

“I would prefer to smell it to know the danger is there,” Reyes said.

Despite the progress made, after weeks of hearing “inconsistent information” from the county, including the estimated time of resolving the problem, it’s hard for her to trust what officials say, Terrell said.

‘Tremendous progress’ in hydrogen sulfide gas levels, county says

Since mid-October, Los Angeles County has been treating the water in the Dominguez Channel by spraying 13,000 gallons of an odor neutralizer, Epoleon, which is used to treat sewage water, onto the channel’s water each day from six locations off bridges, using boats and drones to access hard-to-reach places, county Department of Public Works Director Mark Pestrella said.

Crews have also been running aeration devices, which inject tiny bubbles into the water to introduce oxygen and help combat the by-production of hydrogen sulfide that’s generated by decay and decomposition of organic matter.

“The good news is that we’ve made tremendous progress in reducing the odors in the community,” Pestrella said.

The state’s acceptable levels of hydrogen sulfide are 30 parts per billion, and the South Coast Air Quality Management District has reported that one-hour average levels of hydrogen sulfide have reached or dipped below 10 ppb for at least seven consecutive days for all local community air monitors, except for one monitor at Carson at 213th and Chico streets, which is mounted next to the Dominguez Channel.

In mid-October, residents were experiencing hydrogen sulfide gas in levels close to 7,000 ppb.

Comparison between hydrogen sulfide levels readings from mobile monitors between October and November 2021.

The air monitor at 213th and Chico streets, which was added as a temporary monitor last month, read a peak of around 40 ppb on Tuesday, Nov. 9, according to South Coast AQMD data presented by Jason Low, head of the South Coast Air Quality Management District air monitoring division.

On top of the stationary air monitors, South Coast AQMD staff also tested areas from Long Beach to Carson using mobile monitors over this past weekend, and the highest levels of hydrogen sulfide were 58 ppb through the entire route, Low said. He expects overall levels to continue dropping.

Low said that while levels are slowly and steadily declining, this doesn’t mean that odors have ceased as “the human nose is a very sensitive instrument to essentially detect these odors, and can be impacted even at these very low levels.”

Some people can smell hydrogen sulfide at levels as low as 0.4 ppb, Davis said.

As of Wednesday night, Low reported that the South Coast AQMD received more than 4,300 complaints about the foul odor since Oct. 3.

So far, the county has relocated 3,000 families at local hotels and distributed over 16,100 portable air filters, Pestrella said.

A screenshot of a town hall presentation of a map showing those who sought assistance with relocation to hotels or air purifiers.

County public works, whose director takes responsibility for this foul odor crisis, has been leading the remediation plan and partnering with a variety of local and regional agencies.

“There’s been great consensus by our agency partners across the state and nationally that the tools that we’re using are effective and the right thing to do with respect to the conditions that we have with the water,” Pestrella said.

Now that they’ve gathered more data to understand this month-long crisis, “we can now predict how long it will take before we’re completely done with treating this water,” he said, however, no one at Wednesday’s town hall provided an estimated timeframe for the problem to be resolved.

Outraged by the prolonged exposure to higher-than-normal hydrogen sulfide levels, residents have filed a lawsuit against a local company they blame for a negligent discharge of chemicals. Many residents are also angry at local agencies’ response times to the stench that has caused miserable living conditions for them. Carson city officials last week approved possible litigation against the county for its “lack of urgent reaction.”

For his part, Reyes hopes resolution comes in time for him to return home for Thanksgiving.

“We just want to come home, and it’s kind of getting old.”

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Crystal Niebla is the West Long Beach reporter through the Report for America program. Philanthropic organizations pledged to cover the local donor portion of her grant-funded position with the Post. If you want to support Crystal's work, you can donate to her Report For America position at