Overview

In response to community concerns, South Coast AQMD is conducting a short-term air sampling and analysis initiative near the All American Asphalt facility to determine what emissions if any, are impacting nearby communities.

An All American Asphalt Community Air Monitoring summary can be found here.

South Coast AQMD Air Monitoring Initiative

As technical experts committed to protecting public health, South Coast AQMD uses the most appropriate technology, methods and approaches for each air monitoring purpose, which for this case is the evaluation of gaseous air toxics (e.g. benzene, toluene and xylene) in the Irvine community. This follows strict quality control criteria and analysis based upon U.S. EPA guidance methods. These methods ensure that the data is accurate so that we can confidently compare the data with health-based thresholds and other air toxics measurement programs that have been conducted nationwide.  Samples collected are compared against typical background levels for residential or commercial areas, as well as health-based standards established by the California Office of Environmental Health Hazard Assessment (OEHHA). 

Monitoring Data

Data from this sampling effort will help guide South Coast AQMD’s next steps. The sampling results will be posted below as they become available.

Please note, many factors can contribute to slightly higher levels of pollutants on any given day such as wind direction or increase of other sources including car or truck traffic, use of paints and cleaning supplies—all of which can emit VOC’s into the atmosphere. 

Results of Air Monitoring in Communities Nearby All American Asphalt

Compounds listed in the graphs represent some of the common air toxics from operations at asphalt facilities. The complete sampling reports can be found in Table 1 below.

* South Coast AQMD follows strict quality control procedures and may invalidate a sample due to a variety of reasons which includes equipment malfunction, loss of power, and operational issues due to the COVID-19 pandemic. South Coast AQMD works to resolve any issues as quickly as possible.

Sampling Locations

South Coast AQMD has two monitoring locations: one at Eastwood Elementary School and the other in the community of Orchard Hills. The Orchard Hills air sampler is located next to a community tVOC monitor used by Dr. Jun Wu and other University of California, Irvine advisors. Having both monitors will help South Coast AQMD identify the specific pollutant detected during any potential short-term incident and provide the additional information to the community. South Coast AQMD’s state of the art laboratory can detect down to parts per billion for many pollutants and can provide specific pollutant detail for short term events, even with a 24-hour average time integrated sample. Our monitoring will be able to show if there were substantial gaseous air toxic levels of air pollution in the community, and the data from the community tVOC sensors may provide details on the timing if short term events occur. Should levels continue to be within background levels, air monitoring efforts will conclude in July.

Previous sampling locations were at Northwood High School and Canyon View Elementary. Many factors contributed to the selection of the sample sites including proximity to the facility, odor complaints and communities impacted.

Figure 1 - South Coast AQMD Past and Current Sampling Sites

Other Monitoring Efforts In This Community

Blake Lab: Community members are working with advisors at UC Irvine to collect a small number of short-term air samples. These “grab samples” were analyzed in the laboratory for gaseous air toxics, and the effort sought to compare levels in samples collected during odor events to those collected when no odors were present. The data from these sampling efforts are posted here: https://sites.uci.edu/rowlandblakelab/.

City of Irvine: The City of Irvine hired a contractor to collect and analyze some air samples at and near the facility. The data from these sampling efforts are posted here: https://www.cityofirvine.org/community-development/all-american-asphalt-air-sample-summary-details.

Jun Wu Research Group, UC Irvine: Used a low-cost sensor (Atmotube ProTM) for continuously measuring ambient Volatile Organic Compound (VOC) levels to see if there were patterns in time and at different locations in the Irvine community starting in November 2020. The same type of low-cost sensors were evaluated by South Coast AQMD. Testing results show that VOC levels measured by the low-cost sensors were biased high and did not correlate with actual concentrations. (see Field Testing Evaluation of the Atmotube Pro Sensor Below). In a letter sent to the community on August 4th, 2021, Dr. Wu cautioned that the data from the low cost sensor should not be used “to make any health risk estimates or source characterization.” See copy of full letter here (PDF).

July 27, 2021 – Field Testing Evaluation of the Atmotube Pro Sensor
From March 31 through April 21, 2021, South Coast AQMD tested the performance of six Atmotube Pro sensors (the same type of sensors that were used by the Jun Wu Research Group in Irvine) to see if they accurately respond to total volatile organic compounds (VOC) and accurately measure the ambient concentration of total VOCs. The test was conducted at one of South Coast AQMD’s air monitoring sites in Wilmington, east of a petroleum refinery and west of a major freeway (I-110) – an ideal site for conducting air monitoring of VOCs.

All Atmotube Pro sensors were run side-by-side with a more expensive and reliable “reference” instrument to assess performance. Testing results indicate that VOC concentrations measured by the Atmotube Pro sensors did not correlate with measurements recorded by the “reference” instrument. The sensors overestimated VOC concentrations and reported high levels of VOCs when concentrations were low, suggesting levels measured in the Irvine community were not accurate or precise, and were biased high. The testing results suggest the sensor devices should have been tested and calibrated prior to field deployment. A technical report summarizing South Coast AQMD’s field testing evaluation of the Atmotube Pro sensor can be found here (PDF).

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More Information:

• OEHHA health-based exposure levels