South Coast Air Quality Officials Monitoring Air Quality, Inspecting ExxonMobil Refinery during Expected Startup Tonight

May 9, 2016

Recent Air Quality Measurements in Torrance have not exceeded any Health Thresholds

A team of SCAQMD inspectors and air monitoring scientists will work from 7 p.m. tonight to 7 a.m. tomorrow during the ExxonMobil refinery’s expected startup to monitor outdoor air quality and inspect refinery equipment. This timeframe includes a six-hour period when the air pollution control system for a key piece of equipment is temporarily turned off for safety reasons.

“We are implementing comprehensive measures to protect nearby residents when the refinery starts up and resumes operations,” said Wayne Nastri, acting executive officer for the South Coast Air Quality Management District. Air quality scientists have been monitoring air quality at and near the facility since April 29 and inspectors have been inspecting equipment inside the facility on a regular basis during the past two weeks, he added.

SCAQMD’s activities include:

  • Monitoring air quality for fine particulate (known as PM2.5 and PM10) at two fixed locations, one inside the refinery fence line and the other in the community;

  • Driving two vehicles equipped with real-time particulate monitors through the community; and

  • Inspecting equipment and the startup process inside the refinery to ensure that it follows all requirements of an abatement order issued by SCAQMD’s Hearing Board.

Complete information on SCAQMD’s activities regarding the refinery startup is at

In addition real-time air quality measurements from monitors at and near the refinery are displayed at (In the upper right-hand corner of the web page, click on the drop down box and select one of the ExxonMobil options.) For more information on SCAQMD’s air monitoring at these sites, see the FAQ at

Viewers should note that all real-time data is preliminary and subject to validation. For example, on Friday, May 6, from 6 a.m. to 11 a.m. one of the instruments failed an automatic quality-control check and reported 1-hour readings of 65,530 micrograms per cubic meter (ug/m3) indicating an error message.

These values were inadvertently displayed on SCAQMD’s website, resulting in 24-hour average PM2.5 levels of more than 21,000 ug/m3. Neither of those extremely high numbers reflected actual air quality at that site. The instrument data quality check has been corrected to avoid similar occurrences in the future.

Most PM2.5 hourly levels at the two sites have been below 10 ug/m3. The federal health standard for PM 2.5 averaged over 24 hours is 35 ug/m3.

As a result of the refinery shutting down a pollution control system for six hours between 7 p.m. tonight and 7 a.m. tomorrow, the facility could emit up to 600 pounds of excess particulate emissions.

SCAQMD staff has conducted a detailed scientific analysis of the short-term excess emissions and does not expect it to expose residents to air quality levels that exceed health-based thresholds.

The SCAQMD is the air pollution control agency for Orange County and major portions of Los Angeles, San Bernardino and Riverside counties.

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