R.J. Noble developed a Health Risk Assessment (HRA) based on 2017 emissions data from its asphalt plant in the County of Orange. The HRA showed that emissions of toxic air pollutants such as cobalt and arsenic, which potentially cause cancer and non-cancer health effects, exceeded South Coast AQMD thresholds. R.J. Noble is required to submit a Risk Reduction Plan (RRP) to South Coast AQMD by Jan. 22, 2026.

LOCATION AND SITE DETAILS

R.J. Noble’s Hot Mix Asphalt facility is located at 15505 E. Lincoln Ave. in an unincorporated area of Orange County. This facility produces asphalt concrete mix, which is comprised of aggregate and asphalt oil. Surrounding the site are residential neighborhoods, and businesses with the Santa Ana River bordering the facility on the west side. R.J. Noble has been operating in unincorporated Orange County since 1950.

AB 2588: AIR TOXICS “HOT SPOTS” PROGRAM

The Air Toxics “Hot Spots” Information and Assessment Act was enacted in 1987 and requires stationary sources to report the types and quantities of certain toxic substances their facilities routinely release into the air. South Coast AQMD, the local air quality regulatory agency, enforces these requirements in Rule 1402. The facility, the City of Orange, and unincorporated Orange County falls under South Coast AQMD’s jurisdiction.  

Under this rule, facilities like R.J. Noble are required to periodically submit emissions data. Based on this data, facilities with potential offsite impacts are required to conduct health risk assessments to quantify the risk in the surrounding community. If the risk exceeds certain thresholds, the facility is required to notify impacted residents and reduce risk from their operations.

Next Steps: Risk Reduction Plan

• R.J. Noble must submit a Risk Reduction Plan (RRP) by Jan. 22, 2026.
• Plan details how they will reduce risk below thresholds.
• Actions must be permanent, quantifiable, and enforceable.
• South Coast AQMD reviews and approves the RRP.
• RRP will be implemented as soon as feasible but no later than two and a half years from the approval date.

Nov. 19, 2025 Public Meeting

R.J. Noble sent notification letters to residents living in areas above health risk thresholds to provide information and announce a public meeting. On Nov. 19, 2025, South Coast AQMD held a public meeting to discuss the results of R.J. Noble’s approved Health Risk Assessment and the potential impact to public health.

Click here for the presentation.

South Coast AQMD Releases Health Risk Assessment for R.J. Noble

South Coast AQMD approved the HRA for R.J. Noble on Sept. 24, 2025. R.J. Noble was required to submit the HRA based on air toxic emissions in their approved Air Toxics Inventory Report (based on the 2017 inventory year). The approval letter and details of the HRA can be found at the links below.

• R.J. Noble HRA Approval Letter from AQMD
• Health Risk Assessment Findings

South Coast AQMD Links

• Website
• To join South Coast AQMD's general mailing list for periodic updates, click here.
• Air Quality Map
• To receive daily pollution forecasts or alerts for specific pollution levels in your area, sign up for Air Alerts or download the app.
• Air Quality Complaints Hotline: Submit an air quality complaint at www.aqmd.gov/complaints or call 1-800-CUT-SMOG.