2025 HF Sinclair Navajo Clean Air Act Settlement Agreement Summary

On January 17, 2025, the U.S. Environmental Protection Agency (EPA), the Department of Justice (DOJ), and the New Mexico Environment Department announced a settlement agreement with HF Sinclair Navajo Refining LLC for Clean Air Act and New Mexico Air Quality Control Act violations at the company’s oil refinery in Artesia, NM. The violations are related to excess emissions of hazardous air pollutants, including benzene, volatile organic compounds, nitrogen oxides, and sulfur dioxides.   

HF Sinclair Navajo will pay a civil penalty of $35 million and spend an estimated $137 million to implement compliance measures, including significant capital investments to address and correct the Clean Air Act violations and reduce refinery emissions. The company must also operate 10 real-time air pollution monitors along the refinery fenceline and one real-time air pollution monitor and six other passive monitors in the town of Artesia to measure refinery air pollution emissions and make the results available on a public website. The settlement requirements will result in estimated emission reductions of approximately 3,000 tons per year. 

• Overview of HF Sinclair Navajo Refining LLC 
• Summary of the Violations
• Overview of Environmental and Health Impacts
• Summary of Consent Decree
• Environmental Benefits
• Contact Information 

Overview of HF Sinclair Navajo Refining LLC

HF Sinclair Navajo Refining LLC is a subsidiary of HF Sinclair Corp., headquartered in Dallas, TX. HF Sinclair Corp. owns and operates seven refineries across the United States. 

The Artesia Refinery processes about 100,000 barrels per day of crude and serves markets in the southwestern United States, including New Mexico, Arizona, and West Texas.  

Summary of the Violations 

Overview of Environmental and Health Impacts

Benzene, VOCs, nitrogen oxides, and sulfur dioxide contribute to a variety of health impacts and environmental damage.  

Benzene, classified as a Group A human carcinogen, has short- and long-term health consequences. Short-term exposure can irritate the eyes, skin and respiratory system. Chronic, or long-term inhalation exposure has caused various blood disorders and reproductive effects. 

VOCs are a key component in the formation of ground-level ozone, a pollutant that irritates the lungs, exacerbates diseases such as asthma, and can increase susceptibility to respiratory illnesses, such as pneumonia and bronchitis.  

Nitrogen oxides can cause ground-level ozone, acid rain, particulate matter, global warming, water quality deterioration, and visual impairment. Children, and people with lung diseases and who work or exercise outside are susceptible to health effects such as damaged lung tissue and reduced lung function. 

High concentrations of sulfur dioxide may affect breathing and aggravate existing respiratory and cardiovascular disease. Sensitive populations include asthmatics, individuals with bronchitis or emphysema, children and the elderly. 

Summary of Consent Decree

HF Sinclair Navajo will pay a total penalty of $35 million, comprising a $33,916,450 civil penalty to resolve its Clean Air Act violations and $1,083,550 for its violations of an earlier consent decree. The company will pay the penalty as follows:  

• $17.5 million to the United States  
• $17.5 million to New Mexico  

The consent decree requires the company to implement compliance measures estimated to cost $137 million, including significant capital investments to address and correct the Clean Air Act violations and to reduce emissions at its refinery. Highlights of these activities include:  

Benzene Fenceline Monitoring 

• Monitor and take corrective actions to minimize fenceline benzene concentrations, which includes operating and maintaining real-time fenceline benzene monitors. Monitoring results and corrective actions will be available on public websites. 
• Install six passive benzene monitors and one real-time monitor in the surrounding community within 0.5 miles of the refinery.  

Flaring 

• Install and operate a flare gas recovery system that will capture and recycle gases for use as a fuel that would otherwise be sent to refinery flares, thus reducing emissions of nitrogen oxides and sulfur dioxide. The recycling of the flare gas reduces the use of purchased natural gas to fuel heaters and boilers. 

Refinery Wastewater Streams 

• Complete capital improvement projects to control benzene emissions from wastewater streams, including the installation of a new stripper that will remove benzene from wastewater streams before they enter the wastewater treatment system. 
• Annually review process information to ensure all new waste streams are included and managed in a waste stream inventory. 

Leak Detection and Repair 

• Install and use low emission components or leak free design components and implement management of change and quality assurance and quality control measures to ensure leak detection and repair requirements for all components subject to leak detection and repair regulations. 

Storage Vessels 

• Implement an enhanced monitoring and inspection program at storage vessels to quickly identify and address emissions plus other work practice standards to ensure compliance with applicable regulations. 
• Complete capital improvement projects to reduce VOC emissions from storage vessels, including the installation of geodesic domes on six storage vessels.   

Heat Exchangers  

• Implement requirements for monthly monitoring and routine inspections and testing of cooling water heat exchangers and repair, root cause analysis, and corrective action requirements for heat exchanger leaks. 

Leak Detection Sensor Network 

• Operate a Leak Detection Sensor Network in a portion of the refinery for two years to detect and repair leaks more quickly.  

Emission Audits 

• Conduct a facility-wide emissions audit to provide information about VOC and benzene emission levels from sources after implementation of emission reduction projects required by the settlement. 

Environmental Benefits

This settlement is estimated to result in the following emissions reductions in tons per year (tpy) for an estimated total reduction of approximately 3,000 tons per year: 

• Hazardous air pollutants (including benzene) by 180 tpy 
• VOC emissions by 2,716 tpy 
• Nitrogen oxide emissions by 51 tpy 
• Sulfur dioxide emissions by 31 tpy 

Contact Information

For additional information on this settlement, please contact:  

Patrick Foley 
Senior Environmental Engineer 
Office of Enforcement and Compliance Assurance 
foley.patrick@epa.gov

James Haynes 
Physical Scientist 
Enforcement and Compliance Assurance Division 
EPA Region 6 
haynes.james@epa.gov