Dominguez Channel Odor Event

South Coast AQMD is conducting an active investigation into odors from the Dominguez Channel. The agency has responded to about four thousand odor complaints from residents in Carson, as well Gardena, Long Beach, Redondo Beach, Torrance and Wilmington and other parts of L.A. County. A map showing general areas where complaints have been recorded can be found here.

Air monitoring efforts in the impacted area continue and include a variety of technologies and strategies such as handheld monitors that provide instant readings at a specific location, grab samples for laboratory analysis, mobile monitoring to assess which areas are the most impacted by this odor event, and more than a dozen fixed air monitors at specific locations throughout the community.

Overall, results continue to show elevated levels of hydrogen sulfide (H2S) that can cause strong odors and be a public nuisance. Hydrogen sulfide is a colorless and odorous gas that smells like rotten eggs. Most individuals can smell the odor at very low levels, and some may generally experience symptoms such as headaches and nausea. People experiencing symptoms are encouraged to contact their health care providers.

South Coast AQMD continues to share data with our partners at the Los Angeles County Department of Public Health (DPH) to assist with their ongoing health guidance and assessments.

The investigation is ongoing, and we continue to work closely with the Los Angeles Fire Department/Hazmat, Los Angeles County Department of Public Works (DPW), DPH and other local agencies in this odor event.  

The public can continue to report odors to South Coast AQMD at 1-800-CUT-SMOG (1-800-288-7664) or through the On-line Complaint System. 

More information on the response can be found on the L.A. County Office of Emergency Management webpage.

Residents impacted by the odors who need assistance with submitting a claim form or need access to resources, please call 2-1-1.

Handheld Monitoring (Jerome Analyzer)

The handheld monitor is a portable air monitor that can take measurements for hydrogen sulfide (H2S) in just seconds. These types of instant results provide inspectors and air monitoring technicians an opportunity to identify potential “hot spot” areas. In addition, seven instant (grab) samples were collected for laboratory analysis for H2S and other pollutants (see lab reports below).

The maps below show H2S levels found at various locations and times during the day. Elevated levels of H2S were found along the Dominguez Channel, but fluctuated throughout the day. High levels found using handheld devices provide quick information and help guide the investigation. Levels of H2S can fluctuate based on weather patterns, wind and time of day. 


10/06/21 Lab Report

10/08/21 Lab Report Sample 1

10/08/21 Lab Report Sample 2

10/08/21 Lab Report Sample 3

10/08/21 Lab Report Sample 4

Community Mobile Monitoring

On October 10 through 14, 2021, mobile monitoring was conducted between 6:30 a.m. and 5:30 p.m. near the Dominguez Channel and in and around surrounding communities where odor complaints have been received.  Overall, mobile monitoring showed elevated levels of H2S with the highest levels along the Dominguez Channel. Results also show some elevated levels in Carson communities and areas adjacent to the Dominguez Channel.

On November 6 and 8, 2021, mobile monitoring was conducted between the hours of 11:30-5:30 p.m. near the Dominguez Channel and in surrounding communities. Some elevated levels were found in locations near the channel, however overall levels of H2S showed drastic improvement from original data collected in October.

Please note that the below maps show a snapshot in time, and levels can change in an instant based on weather and wind patterns.

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Mobile Monitoring maps for specific days can be found below:

November 6-8, 2021

October 10, 2021

October 11, 2021

October 12, 2021

October 14, 2021

Volatile Organic Compounds (VOCs) and Air Toxic Pollutants

South Coast AQMD has also been conducting monitoring and sampling for VOCs and other air toxics. To date, our data shows no elevated levels of VOCs or other air toxic pollutants (e.g., benzene) that would be typically associated with direct petroleum emission sources such as oil pipes or refineries.

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10/8/21 Lab Sample 1

10/8/21 Lab Sample 2

10/8/21 Lab Sample 3

Rule 1180 Fenceline and Community Air Monitoring

South Coast AQMD also has 12 fixed air monitors located throughout the community as part of its Rule 1180 Refinery Fenceline and Community Air Monitoring Program (see map below). These air monitors provide continuous, real-time measurements of H2S, VOCs, and other air pollutants 24-hours a day. Community members can sign up to receive automatic email notifications if air pollution levels reach elevated levels.  Click here to sign up for email notifications.  

To view near real-time data from this robust air monitoring system, as well as past data, please visit the air monitoring page.

A new, temporary monitor has been placed near E 213th street and the Dominguez Channel to provide additional data on this odor event and its impacts to communities near the Channel. The new monitor (213th & Chico) is taking real-time measurements of H2S 24 hours a day.

H2S 1-hour Data: All H2S data displayed in this Table is preliminary and is subject to final quality assurance and validation. Data listed is the 1-hour average for that day and time. N/A means that data at a specific location and date/time is not available due to a variety of reasons such as loss of communication, equipment malfunction, instrument maintenance, etc.

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