Use of South Coast AQMD’s monitor air quality data is at the user’s discretion and should be done with caution. The intent of the monitoring data is to provide air quality information that is supplemental to the existing South Coast AQMD air quality monitoring regional coverage. This monitor is intended to represent PM10 concentrations, in which the objective is to determine the potential air quality impact of PM10 near communities downwind of the Vulcan Materials Company operation near Duarte. Measurements from this monitor alone cannot determine the relative contributions of regional or source-specific origins to PM10. Local conditions for pollutants can vary widely based on meteorological conditions and proximity to sources of PM10.

Data provided on this website has been reviewed but not yet finalized, and is therefore subject to change. Continuous PM10 monitors such as this may be disrupted for periodic weekly maintenance and quality checks, as well as unforeseen power failures and instrument malfunctions. Data provided is representative only of valid hourly averages, whereby hourly averages with less than 75% valid minute averages are omitted consistent with U.S. EPA Quality Assurance guidelines. Finalized data is cross checked with specifications and Quality Assurance Audit thresholds.

For finalized/official data, please contact South Coast AQMD Public Affairs and submit a Public Records Request: Public Records

South Coast AQMD provides no guarantee, either express or implied, as to the accuracy, reliability or completeness of data furnished via the website, maps, or of the forecasts provided in the South Coast AQMD website. Further, South Coast AQMD shall not be liable under any circumstances for any direct, special, incidental or consequential damages with respect to any claim by any user or third party as a result of, or arising from, the use of the data, forecasts or maps.