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Home My WebLink AboutAir PM Results March 2025Saturday, March 1, 2025 North Hangar Fire Incident I City of Tustin Air Quality Updates: Particulate Matter Air monitoring and sampling locations have been set up around the perimeter of the hangar and in surrounding communities to provide real-time information on Particulate Matter (PM) in the air. While the units are in place, an average reading for the last 24 hours will be provided for the public's reference. Any questions regarding these numbers should be directed to the call center at 714-426-2444. Monitoring Air Quality for Sensitive Individuals An environmental group contracted by the U.S. Navy is monitoring the air quality around the incident for any readings above 154 micrograms per cubic meter (ug/m3), which may cause individuals in sensitive groups to experience health effects. This is a moderate threshold that is less likely to affect the general public. What is Particulate Matter? "Particulate matter," also known as particle pollution or PM, is a complex mixture of extremely small particles and liquid droplets that exists in the environment including pollen, dust, and soil. Typical particulate matter for the area ranges from 3 to 67 ug/m3. The concentration range is based on sampling results collected by South Coast AQMD in Anaheim, CA, which was the closest available dataset in proximity to the site. For more information about air quality and monitoring, visit the AirNow website at www.airnow.gov. Good Moderate (0 to 54) (55 to 154) Unhealthyfor Wnhealthy Sensitive Groups (255 to Unhealthy EL(155 to 254)354) See below for further category descriptions. ** Data gap due to instrument malfunction Very Unhealthy Hazardous (355 to 424) (425-504) Location Columbus Square Park Period Ending 03/01/2025 8 AM Matter 11 Level of Concern Good Hangar Fenceline - E Side 03/01/2025 8 AM 14 Good Hangar Fenceline - N Center 03/01/2025 8 AM 10 Good Hangar Fenceline - N Corner 03/01/2025 8 AM 9 Good Hangar Fenceline - NE Corner 03/01/2025 8 AM 13 Good Hangar Fenceline - NE Side 03/01/2025 8 AM 10 Good Hangar Fenceline - S Corner 03/01/2025 8 AM 16 Good Hangar Fenceline - S Side 03/01/2025 8 AM 13 Good Hangar Fenceline - SW Corner 03/01/2025 8 AM 12 Good Hangar Fenceline - SW Side 03/01/2025 8 AM 8 Good • •24-Hour Hangar Fenceline - W Side Period • • 03/01/2025 8 AM Particulate Matter ** Level of Concern ** Legacy Road 03/01/2025 8 AM 23 Good Moffett and Tustin Ranch 03/01/2025 8 AM 20 Good Valencia and Armstrong 03/01/2025 8 AM ** ** Valencia and Columbus Square 03/01/2025 8 AM 9 Good Valencia and Legacy 03/01/2025 8 AM 7 Good Victory and Tustin Ranch Rd. 03/01/2025 8 AM 6 Good Warner Avenue 03/01/2025 8 AM 8 Good Warner and Armstrong 03/01/2025 8 AM 8 Good Category Descriptions Color Green Good 0 to 54 Air quality is satisfactory, and air pollution poses little or no risk. Yellow Moderate 55 to 154 Air quality is acceptable. However, there may be a risk for some people, particularly those who are unusually sensitive to air pollution. Orange Unhealthy for Sensitive 155 to 254 Members of sensitive groups may Groups experience health effects. The general public is less likely to be affected. Red Unhealthy 255 to 354 Some members of the general public may experience health effects; members of sensitive groups may experience more serious health effects. Purple Very Unhealthy 355 to 424 Health alert: The risk of health effects is increased for everyone. Hazardous 425 to 504 Health warning of emergency - conditions: ever. . likely ..- affected. Sunday, March 2, 2025 North Hangar Fire Incident I City of Tustin Air Quality Updates: Particulate Matter Air monitoring and sampling locations have been set up around the perimeter of the hangar and in surrounding communities to provide real-time information on Particulate Matter (PM) in the air. While the units are in place, an average reading for the last 24 hours will be provided for the public's reference. Any questions regarding these numbers should be directed to the call center at 714-426-2444. Monitoring Air Quality for Sensitive Individuals An environmental group contracted by the U.S. Navy is monitoring the air quality around the incident for any readings above 154 micrograms per cubic meter (ug/m3), which may cause individuals in sensitive groups to experience health effects. This is a moderate threshold that is less likely to affect the general public. What is Particulate Matter? "Particulate matter," also known as particle pollution or PM, is a complex mixture of extremely small particles and liquid droplets that exists in the environment including pollen, dust, and soil. Typical particulate matter for the area ranges from 3 to 67 ug/m3. The concentration range is based on sampling results collected by South Coast AQMD in Anaheim, CA, which was the closest available dataset in proximity to the site. For more information about air quality and monitoring, visit the AirNow website at www.airnow.gov. Good Moderate (0 to 54) (55 to 154) Unhealthyfor Wnhealthy Sensitive Groups (255 to Unhealthy EL(155 to 254)354) See below for further category descriptions. ** Data gap due to instrument malfunction Very Unhealthy Hazardous (355 to 424) (425-504) Location Columbus Square Park Period Ending 03/02/2025 8 AM Matter 13 Level of Concern Good Hangar Fenceline - E Side 03/02/2025 8 AM 16 Good Hangar Fenceline - N Center 03/02/2025 8 AM 11 Good Hangar Fenceline - N Corner 03/02/2025 8 AM 10 Good Hangar Fenceline - NE Corner 03/02/2025 8 AM 14 Good Hangar Fenceline - NE Side 03/02/2025 8 AM 12 Good Hangar Fenceline - S Corner 03/02/2025 8 AM 14 Good Hangar Fenceline - S Side 03/02/2025 8 AM 14 Good Hangar Fenceline - SW Corner 03/02/2025 8 AM 14 Good Hangar Fenceline - SW Side 03/02/2025 8 AM 9 Good • •24-Hour Hangar Fenceline - W Side Period • • 03/02/2025 8 AM Particulate Matter ** Level of Concern ** Legacy Road 03/02/2025 8 AM 12 Good Moffett and Tustin Ranch 03/02/2025 8 AM 22 Good Valencia and Armstrong 03/02/2025 8 AM 3 Good Valencia and Columbus Square 03/02/2025 8 AM 11 Good Valencia and Legacy 03/02/2025 8 AM 8 Good Victory and Tustin Ranch Rd. 03/02/2025 8 AM 7 Good Warner Avenue 03/02/2025 8 AM ** ** Warner and Armstrong 03/02/2025 8 AM 9 Good Category Descriptions Color Green Good 0 to 54 Air quality is satisfactory, and air pollution poses little or no risk. Yellow Moderate 55 to 154 Air quality is acceptable. However, there may be a risk for some people, particularly those who are unusually sensitive to air pollution. Orange Unhealthy for Sensitive 155 to 254 Members of sensitive groups may Groups experience health effects. The general public is less likely to be affected. Red Unhealthy 255 to 354 Some members of the general public may experience health effects; members of sensitive groups may experience more serious health effects. Purple Very Unhealthy 355 to 424 Health alert: The risk of health effects is increased for everyone. Hazardous 425 to 504 Health warning of emergency - conditions: ever. . likely ..- affected. Monday, March 3, 2025 North Hangar Fire Incident I City of Tustin Air Quality Updates: Particulate Matter Air monitoring and sampling locations have been set up around the perimeter of the hangar and in surrounding communities to provide real-time information on Particulate Matter (PM) in the air. While the units are in place, an average reading for the last 24 hours will be provided for the public's reference. Any questions regarding these numbers should be directed to the call center at 714-426-2444. Monitoring Air Quality for Sensitive Individuals An environmental group contracted by the U.S. Navy is monitoring the air quality around the incident for any readings above 154 micrograms per cubic meter (ug/m3), which may cause individuals in sensitive groups to experience health effects. This is a moderate threshold that is less likely to affect the general public. What is Particulate Matter? "Particulate matter," also known as particle pollution or PM, is a complex mixture of extremely small particles and liquid droplets that exists in the environment including pollen, dust, and soil. Typical particulate matter for the area ranges from 3 to 67 ug/m3. The concentration range is based on sampling results collected by South Coast AQMD in Anaheim, CA, which was the closest available dataset in proximity to the site. For more information about air quality and monitoring, visit the AirNow website at www.airnow.gov. Good Moderate (0 to 54) (55 to 154) Unhealthyfor Wnhealthy Sensitive Groups (255 to Unhealthy EL(155 to 254)354) See below for further category descriptions. ** Data gap due to instrument malfunction Very Unhealthy Hazardous (355 to 424) (425-504) Location Columbus Square Park Period Ending 03/03/2025 8 AM Matter 12 Level of Concern Good Hangar Fenceline - E Side 03/03/2025 8 AM 16 Good Hangar Fenceline - N Center 03/03/2025 8 AM ** ** Hangar Fenceline - N Corner 03/03/2025 8 AM 9 Good Hangar Fenceline - NE Corner 03/03/2025 8 AM ** ** Hangar Fenceline - NE Side 03/03/2025 8 AM 10 Good Hangar Fenceline - S Corner 03/03/2025 8 AM ** ** Hangar Fenceline - S Side 03/03/2025 8 AM 13 Good Hangar Fenceline - SW Corner 03/03/2025 8 AM 11 Good Hangar Fenceline - SW Side 03/03/2025 8 AM 7 Good • •24-Hour Hangar Fenceline - W Side Period • • 03/03/2025 8 AM Particulate Matter ** Level of Concern ** Legacy Road 03/03/2025 8 AM 15 Good Moffett and Tustin Ranch 03/03/2025 8 AM 22 Good Valencia and Armstrong 03/03/2025 8 AM ** ** Valencia and Columbus Square 03/03/2025 8 AM 9 Good Valencia and Legacy 03/03/2025 8 AM 6 Good Victory and Tustin Ranch Rd. 03/03/2025 8 AM 7 Good Warner Avenue 03/03/2025 8 AM 6 Good Warner and Armstrong 03/03/2025 8 AM 7 Good Category Descriptions Color Green Good 0 to 54 Air quality is satisfactory, and air pollution poses little or no risk. Yellow Moderate 55 to 154 Air quality is acceptable. However, there may be a risk for some people, particularly those who are unusually sensitive to air pollution. Orange Unhealthy for Sensitive 155 to 254 Members of sensitive groups may Groups experience health effects. The general public is less likely to be affected. Red Unhealthy 255 to 354 Some members of the general public may experience health effects; members of sensitive groups may experience more serious health effects. Purple Very Unhealthy 355 to 424 Health alert: The risk of health effects is increased for everyone. Hazardous 425 to 504 Health warning of emergency - conditions: ever. . likely ..- affected. Tuesday, March 4, 2025 North Hangar Fire Incident I City of Tustin Air Quality Updates: Particulate Matter Air monitoring and sampling locations have been set up around the perimeter of the hangar and in surrounding communities to provide real-time information on Particulate Matter (PM) in the air. While the units are in place, an average reading for the last 24 hours will be provided for the public's reference. Any questions regarding these numbers should be directed to the call center at 714-426-2444. Monitoring Air Quality for Sensitive Individuals An environmental group contracted by the U.S. Navy is monitoring the air quality around the incident for any readings above 154 micrograms per cubic meter (ug/m3), which may cause individuals in sensitive groups to experience health effects. This is a moderate threshold that is less likely to affect the general public. What is Particulate Matter? "Particulate matter," also known as particle pollution or PM, is a complex mixture of extremely small particles and liquid droplets that exists in the environment including pollen, dust, and soil. Typical particulate matter for the area ranges from 3 to 67 ug/m3. The concentration range is based on sampling results collected by South Coast AQMD in Anaheim, CA, which was the closest available dataset in proximity to the site. For more information about air quality and monitoring, visit the AirNow website at www.airnow.gov. Good Moderate (0 to 54) (55 to 154) Unhealthyfor Wnhealthy Sensitive Groups (255 to Unhealthy EL(155 to 254)354) See below for further category descriptions. ** Data gap due to instrument malfunction Very Unhealthy Hazardous (355 to 424) (425-504) Location Columbus Square Park Period Ending 03/04/2025 8 AM Matter ** Level of Concern ** Hangar Fenceline - E Side 03/04/2025 8 AM 13 Good Hangar Fenceline - N Center 03/04/2025 8 AM 10 Good Hangar Fenceline - N Corner 03/04/2025 8 AM 8 Good Hangar Fenceline - NE Corner 03/04/2025 8 AM 11 Good Hangar Fenceline - NE Side 03/04/2025 8 AM 9 Good Hangar Fenceline - S Corner 03/04/2025 8 AM 14 Good Hangar Fenceline - S Side 03/04/2025 8 AM 13 Good Hangar Fenceline - SW Corner 03/04/2025 8 AM 11 Good Hangar Fenceline - SW Side 03/04/2025 8 AM 7 Good • •24-Hour Hangar Fenceline - W Side Period • • 03/04/2025 8 AM Particulate Matter ** Level of Concern ** Legacy Road 03/04/2025 8 AM 15 Good Moffett and Tustin Ranch 03/04/2025 8 AM 21 Good Valencia and Armstrong 03/04/2025 8 AM ** ** Valencia and Columbus Square 03/04/2025 8 AM 9 Good Valencia and Legacy 03/04/2025 8 AM 6 Good Victory and Tustin Ranch Rd. 03/04/2025 8 AM 5 Good Warner Avenue 03/04/2025 8 AM 6 Good Warner and Armstrong 03/04/2025 8 AM 7 Good Category Descriptions Color Green Good 0 to 54 Air quality is satisfactory, and air pollution poses little or no risk. Yellow Moderate 55 to 154 Air quality is acceptable. However, there may be a risk for some people, particularly those who are unusually sensitive to air pollution. Orange Unhealthy for Sensitive 155 to 254 Members of sensitive groups may Groups experience health effects. The general public is less likely to be affected. Red Unhealthy 255 to 354 Some members of the general public may experience health effects; members of sensitive groups may experience more serious health effects. Purple Very Unhealthy 355 to 424 Health alert: The risk of health effects is increased for everyone. Hazardous 425 to 504 Health warning of emergency - conditions: ever. . likely ..- affected. Wednesday, March 5, 2025 North Hangar Fire Incident I City of Tustin Air Quality Updates: Particulate Matter Air monitoring and sampling locations have been set up around the perimeter of the hangar and in surrounding communities to provide real-time information on Particulate Matter (PM) in the air. While the units are in place, an average reading for the last 24 hours will be provided for the public's reference. Any questions regarding these numbers should be directed to the call center at 714-426-2444. Monitoring Air Quality for Sensitive Individuals An environmental group contracted by the U.S. Navy is monitoring the air quality around the incident for any readings above 154 micrograms per cubic meter (ug/m3), which may cause individuals in sensitive groups to experience health effects. This is a moderate threshold that is less likely to affect the general public. What is Particulate Matter? "Particulate matter," also known as particle pollution or PM, is a complex mixture of extremely small particles and liquid droplets that exists in the environment including pollen, dust, and soil. Typical particulate matter for the area ranges from 3 to 67 ug/m3. The concentration range is based on sampling results collected by South Coast AQMD in Anaheim, CA, which was the closest available dataset in proximity to the site. For more information about air quality and monitoring, visit the AirNow website at www.airnow.gov. Good Moderate Unhealthy for Unhealthy Very Unhealthy • • (0 to 54) (55 to 154) Sensitive Groups 155 to 254) (255 to 354) (355 to 424) (425-504) �( See below for further category descriptions. ** Data gap due to instrument malfunction Location Columbus Square Park 24-Hour Period Ending 03/05/2025 8 AM 16 Good Hangar Fenceline - E Side 03/05/2025 8 AM ** ** Hangar Fenceline - N Center 03/05/2025 8 AM 15 Good Hangar Fenceline - N Corner 03/05/2025 8 AM 13 Good Hangar Fenceline - NE Corner 03/05/2025 8 AM 16 Good Hangar Fenceline - NE Side 03/05/2025 8 AM 15 Good Hangar Fenceline - S Corner 03/05/2025 8 AM 19 Good Hangar Fenceline - S Side 03/05/2025 8 AM 16 Good Hangar Fenceline - SW Corner 03/05/2025 8 AM 18 Good Hangar Fenceline - SW Side 03/05/2025 8 AM 11 Good • •24-Hour Hangar Fenceline - W Side Period • • 03/05/2025 8 AM Particulate Matter ** Level of Concern ** Legacy Road 03/05/2025 8 AM 23 Good Moffett and Tustin Ranch 03/05/2025 8 AM 26 Good Valencia and Armstrong 03/05/2025 8 AM ** ** Valencia and Columbus Square 03/05/2025 8 AM 14 Good Valencia and Legacy 03/05/2025 8 AM 10 Good Victory and Tustin Ranch Rd. 03/05/2025 8 AM 10 Good Warner Avenue 03/05/2025 8 AM 11 Good Warner and Armstrong 03/05/2025 8 AM 12 Good Category Descriptions Color Green Good 0 to 54 Air quality is satisfactory, and air pollution poses little or no risk. Yellow Moderate 55 to 154 Air quality is acceptable. However, there may be a risk for some people, particularly those who are unusually sensitive to air pollution. Orange Unhealthy for Sensitive 155 to 254 Members of sensitive groups may Groups experience health effects. The general public is less likely to be affected. Red Unhealthy 255 to 354 Some members of the general public may experience health effects; members of sensitive groups may experience more serious health effects. Purple Very Unhealthy 355 to 424 Health alert: The risk of health effects is increased for everyone. Hazardous 425 to 504 Health warning of emergency - conditions: ever. . likely ..- affected. Thursday, March 6, 2025 North Hangar Fire Incident I City of Tustin Air Quality Updates: Particulate Matter Air monitoring and sampling locations have been set up around the perimeter of the hangar and in surrounding communities to provide real-time information on Particulate Matter (PM) in the air. While the units are in place, an average reading for the last 24 hours will be provided for the public's reference. Any questions regarding these numbers should be directed to the call center at 714-426-2444. Monitoring Air Quality for Sensitive Individuals An environmental group contracted by the U.S. Navy is monitoring the air quality around the incident for any readings above 154 micrograms per cubic meter (ug/m3), which may cause individuals in sensitive groups to experience health effects. This is a moderate threshold that is less likely to affect the general public. What is Particulate Matter? "Particulate matter," also known as particle pollution or PM, is a complex mixture of extremely small particles and liquid droplets that exists in the environment including pollen, dust, and soil. Typical particulate matter for the area ranges from 3 to 67 ug/m3. The concentration range is based on sampling results collected by South Coast AQMD in Anaheim, CA, which was the closest available dataset in proximity to the site. For more information about air quality and monitoring, visit the AirNow website at www.airnow.gov. Good Moderate (0 to 54) (55 to 154) Unhealthyfor Wnhealthy Sensitive Groups (255 to Unhealthy EL(155 to 254)354) See below for further category descriptions. ** Data gap due to instrument malfunction Very Unhealthy Hazardous (355 to 424) (425-504) Location Columbus Square Park Period Ending 03/06/2025 8 AM Matter 12 Level of Concern Good Hangar Fenceline - E Side 03/06/2025 8 AM 13 Good Hangar Fenceline - N Center 03/06/2025 8 AM 11 Good Hangar Fenceline - N Corner 03/06/2025 8 AM 9 Good Hangar Fenceline - NE Corner 03/06/2025 8 AM 11 Good Hangar Fenceline - NE Side 03/06/2025 8 AM 10 Good Hangar Fenceline - S Corner 03/06/2025 8 AM 12 Good Hangar Fenceline - S Side 03/06/2025 8 AM 13 Good Hangar Fenceline - SW Corner 03/06/2025 8 AM 11 Good Hangar Fenceline - SW Side 03/06/2025 8 AM 7 Good • •24-Hour Hangar Fenceline - W Side Period • • 03/06/2025 8 AM Particulate Matter ** Level of Concern ** Legacy Road 03/06/2025 8 AM ** ** Moffett and Tustin Ranch 03/06/2025 8 AM 22 Good Valencia and Armstrong 03/06/2025 8 AM ** ** Valencia and Columbus Square 03/06/2025 8 AM ** ** Valencia and Legacy 03/06/2025 8 AM 7 Good Victory and Tustin Ranch Rd. 03/06/2025 8 AM ** ** Warner Avenue 03/06/2025 8 AM 8 Good Warner and Armstrong 03/06/2025 8 AM ** ** Category Descriptions Color Green Good 0 to 54 Air quality is satisfactory, and air pollution poses little or no risk. Yellow Moderate 55 to 154 Air quality is acceptable. However, there may be a risk for some people, particularly those who are unusually sensitive to air pollution. Orange Unhealthy for Sensitive 155 to 254 Members of sensitive groups may Groups experience health effects. The general public is less likely to be affected. Red Unhealthy 255 to 354 Some members of the general public may experience health effects; members of sensitive groups may experience more serious health effects. Purple Very Unhealthy 355 to 424 Health alert: The risk of health effects is increased for everyone. Hazardous 425 to 504 Health warning of emergency - conditions: ever. . likely ..- affected. Friday, March 7, 2025 North Hangar Fire Incident I City of Tustin Air Quality Updates: Particulate Matter Air monitoring and sampling locations have been set up around the perimeter of the hangar and in surrounding communities to provide real-time information on Particulate Matter (PM) in the air. While the units are in place, an average reading for the last 24 hours will be provided for the public's reference. Any questions regarding these numbers should be directed to the call center at 714-426-2444. Monitoring Air Quality for Sensitive Individuals An environmental group contracted by the U.S. Navy is monitoring the air quality around the incident for any readings above 154 micrograms per cubic meter (ug/m3), which may cause individuals in sensitive groups to experience health effects. This is a moderate threshold that is less likely to affect the general public. What is Particulate Matter? "Particulate matter," also known as particle pollution or PM, is a complex mixture of extremely small particles and liquid droplets that exists in the environment including pollen, dust, and soil. Typical particulate matter for the area ranges from 3 to 67 ug/m3. The concentration range is based on sampling results collected by South Coast AQMD in Anaheim, CA, which was the closest available dataset in proximity to the site. For more information about air quality and monitoring, visit the AirNow website at www.airnow.gov. Good Moderate Unhealthy for Unhealthy Very Unhealthy • • (0 to 54) (55 to 154) Sensitive Groups 155 to 254) (255 to 354) (355 to 424) (425-504) �( See below for further category descriptions. ** Data gap due to instrument malfunction Location Columbus Square Park 24-Hour Period Ending 03/07/2025 8 AM 17 Good Hangar Fenceline - E Side 03/07/2025 8 AM ** ** Hangar Fenceline - N Center 03/07/2025 8 AM 19 Good Hangar Fenceline - N Corner 03/07/2025 8 AM 12 Good Hangar Fenceline - NE Corner 03/07/2025 8 AM 15 Good Hangar Fenceline - NE Side 03/07/2025 8 AM 16 Good Hangar Fenceline - S Corner 03/07/2025 8 AM ** ** Hangar Fenceline - S Side 03/07/2025 8 AM 18 Good Hangar Fenceline - SW Corner 03/07/2025 8 AM 20 Good Hangar Fenceline - SW Side 03/07/2025 8 AM ** ** • •24-Hour Hangar Fenceline - W Side Period • • 03/07/2025 8 AM Particulate Matter 25 Level of Concern Good Legacy Road 03/07/2025 8 AM ** ** Moffett and Tustin Ranch 03/07/2025 8 AM 26 Good Valencia and Armstrong 03/07/2025 8 AM ** ** Valencia and Columbus Square 03/07/2025 8 AM 16 Good Valencia and Legacy 03/07/2025 8 AM 12 Good Victory and Tustin Ranch Rd. 03/07/2025 8 AM 10 Good Warner Avenue 03/07/2025 8 AM 12 Good Warner and Armstrong 03/07/2025 8 AM 10 Good Category Descriptions Color Green Good 0 to 54 Air quality is satisfactory, and air pollution poses little or no risk. Yellow Moderate 55 to 154 Air quality is acceptable. However, there may be a risk for some people, particularly those who are unusually sensitive to air pollution. Orange Unhealthy for Sensitive 155 to 254 Members of sensitive groups may Groups experience health effects. The general public is less likely to be affected. Red Unhealthy 255 to 354 Some members of the general public may experience health effects; members of sensitive groups may experience more serious health effects. Purple Very Unhealthy 355 to 424 Health alert: The risk of health effects is increased for everyone. Hazardous 425 to 504 Health warning of emergency - conditions: ever. . likely ..- affected. Saturday, March 8, 2025 North Hangar Fire Incident I City of Tustin Air Quality Updates: Particulate Matter Air monitoring and sampling locations have been set up around the perimeter of the hangar and in surrounding communities to provide real-time information on Particulate Matter (PM) in the air. While the units are in place, an average reading for the last 24 hours will be provided for the public's reference. Any questions regarding these numbers should be directed to the call center at 714-426-2444. Monitoring Air Quality for Sensitive Individuals An environmental group contracted by the U.S. Navy is monitoring the air quality around the incident for any readings above 154 micrograms per cubic meter (ug/m3), which may cause individuals in sensitive groups to experience health effects. This is a moderate threshold that is less likely to affect the general public. What is Particulate Matter? "Particulate matter," also known as particle pollution or PM, is a complex mixture of extremely small particles and liquid droplets that exists in the environment including pollen, dust, and soil. Typical particulate matter for the area ranges from 3 to 67 ug/m3. The concentration range is based on sampling results collected by South Coast AQMD in Anaheim, CA, which was the closest available dataset in proximity to the site. For more information about air quality and monitoring, visit the AirNow website at www.airnow.gov. Good Moderate (0 to 54) (55 to 154) Unhealthyfor Wnhealthy Sensitive Groups (255 to Unhealthy EL(155 to 254)354) See below for further category descriptions. ** Data gap due to instrument malfunction Very Unhealthy Hazardous (355 to 424) (425-504) Location Columbus Square Park Period Ending 03/08/2025 8 AM Matter 8 Level of Concern Good Hangar Fenceline - E Side 03/08/2025 8 AM 12 Good Hangar Fenceline - N Center 03/08/2025 8 AM 8 Good Hangar Fenceline - N Corner 03/08/2025 8 AM 6 Good Hangar Fenceline - NE Corner 03/08/2025 8 AM 9 Good Hangar Fenceline - NE Side 03/08/2025 8 AM 7 Good Hangar Fenceline - S Corner 03/08/2025 8 AM 10 Good Hangar Fenceline - S Side 03/08/2025 8 AM 12 Good Hangar Fenceline - SW Corner 03/08/2025 8 AM 10 Good Hangar Fenceline - SW Side 03/08/2025 8 AM 6 Good • •24-Hour Hangar Fenceline - W Side Period • • 03/08/2025 8 AM Particulate Matter 18 Level of Concern Good Legacy Road 03/08/2025 8 AM 17 Good Moffett and Tustin Ranch 03/08/2025 8 AM 20 Good Valencia and Armstrong 03/08/2025 8 AM ** ** Valencia and Columbus Square 03/08/2025 8 AM 7 Good Valencia and Legacy 03/08/2025 8 AM 5 Good Victory and Tustin Ranch Rd. 03/08/2025 8 AM 6 Good Warner Avenue 03/08/2025 8 AM 6 Good Warner and Armstrong 03/08/2025 8 AM 6 Good Category Descriptions Color Green Good 0 to 54 Air quality is satisfactory, and air pollution poses little or no risk. Yellow Moderate 55 to 154 Air quality is acceptable. However, there may be a risk for some people, particularly those who are unusually sensitive to air pollution. Orange Unhealthy for Sensitive 155 to 254 Members of sensitive groups may Groups experience health effects. The general public is less likely to be affected. Red Unhealthy 255 to 354 Some members of the general public may experience health effects; members of sensitive groups may experience more serious health effects. Purple Very Unhealthy 355 to 424 Health alert: The risk of health effects is increased for everyone. Hazardous 425 to 504 Health warning of emergency - conditions: ever. . likely ..- affected. Sunday, March 9, 2025 North Hangar Fire Incident I City of Tustin Air Quality Updates: Particulate Matter Air monitoring and sampling locations have been set up around the perimeter of the hangar and in surrounding communities to provide real-time information on Particulate Matter (PM) in the air. While the units are in place, an average reading for the last 24 hours will be provided for the public's reference. Any questions regarding these numbers should be directed to the call center at 714-426-2444. Monitoring Air Quality for Sensitive Individuals An environmental group contracted by the U.S. Navy is monitoring the air quality around the incident for any readings above 154 micrograms per cubic meter (ug/m3), which may cause individuals in sensitive groups to experience health effects. This is a moderate threshold that is less likely to affect the general public. What is Particulate Matter? "Particulate matter," also known as particle pollution or PM, is a complex mixture of extremely small particles and liquid droplets that exists in the environment including pollen, dust, and soil. Typical particulate matter for the area ranges from 3 to 67 ug/m3. The concentration range is based on sampling results collected by South Coast AQMD in Anaheim, CA, which was the closest available dataset in proximity to the site. For more information about air quality and monitoring, visit the AirNow website at www.airnow.gov. Good Moderate (0 to 54) (55 to 154) Unhealthyfor Wnhealthy Sensitive Groups (255 to Unhealthy EL(155 to 254)354) See below for further category descriptions. ** Data gap due to instrument malfunction tDaylight savings time was recognized during this time Very Unhealthy Hazardous (355 to 424) (425-504) Location Columbus Square Park Period Endingt 03/09/2025 8 AM 15 Good Hangar Fenceline - E Side 03/09/2025 8 AM 19 Good Hangar Fenceline - N Center 03/09/2025 8 AM 15 Good Hangar Fenceline - N Corner 03/09/2025 8 AM 11 Good Hangar Fenceline - NE Corner 03/09/2025 8 AM 15 Good Hangar Fenceline - NE Side 03/09/2025 8 AM 14 Good Hangar Fenceline - S Corner 03/09/2025 8 AM 15 Good Hangar Fenceline - S Side 03/09/2025 8 AM 15 Good Hangar Fenceline - SW Corner 03/09/2025 8 AM 17 Good • •24-Hour Hangar Fenceline - SW Side Period • • t 03/09/2025 8 AM Particulate Matter 12 Level of Concern Good Hangar Fenceline - W Side 03/09/2025 8 AM ** ** Legacy Road 03/09/2025 8 AM 23 Good Moffett and Tustin Ranch 03/09/2025 8 AM 26 Good Valencia and Armstrong 03/09/2025 8 AM 3 Good Valencia and Columbus Square 03/09/2025 8 AM 13 Good Valencia and Legacy 03/09/2025 8 AM 9 Good Victory and Tustin Ranch Rd. 03/09/2025 8 AM 11 Good Warner Avenue 03/09/2025 8 AM 12 Good Warner and Armstrong 03/09/2025 8 AM 11 Good Category Descriptions Color Green Good 0 to 54 Air quality is satisfactory, and air pollution poses little or no risk. Yellow Moderate 55 to 154 Air quality is acceptable. However, there may be a risk for some people, particularly those who are unusually sensitive to air pollution. Orange Unhealthy for Sensitive 155 to 254 Members of sensitive groups may Groups experience health effects. The general public is less likely to be affected. Red Unhealthy 255 to 354 Some members of the general public may experience health effects; members of sensitive groups may experience more serious health effects. Purple Very Unhealthy 355 to 424 Health alert: The risk of health effects is increased for everyone. Hazardous 425 to 5 07to Health warning of emergency conditions: ever•ne is more likely be affected. Monday, March 10, 2025 North Hangar Fire Incident I City of Tustin Air Quality Updates: Particulate Matter Air monitoring and sampling locations have been set up around the perimeter of the hangar and in surrounding communities to provide real-time information on Particulate Matter (PM) in the air. While the units are in place, an average reading for the last 24 hours will be provided for the public's reference. Any questions regarding these numbers should be directed to the call center at 714-426-2444. Monitoring Air Quality for Sensitive Individuals An environmental group contracted by the U.S. Navy is monitoring the air quality around the incident for any readings above 154 micrograms per cubic meter (ug/m3), which may cause individuals in sensitive groups to experience health effects. This is a moderate threshold that is less likely to affect the general public. What is Particulate Matter? "Particulate matter," also known as particle pollution or PM, is a complex mixture of extremely small particles and liquid droplets that exists in the environment including pollen, dust, and soil. Typical particulate matter for the area ranges from 3 to 67 ug/m3. The concentration range is based on sampling results collected by South Coast AQMD in Anaheim, CA, which was the closest available dataset in proximity to the site. For more information about air quality and monitoring, visit the AirNow website at www.airnow.gov. Good Moderate (0 to 54) (55 to 154) Unhealthyfor Wnhealthy Sensitive Groups (255 to Unhealthy EL(155 to 254)354) See below for further category descriptions. ** Data gap due to instrument malfunction Very Unhealthy Hazardous (355 to 424) (425-504) Location Columbus Square Park Period Ending 03/10/2025 8 AM Matter ** Level of Concern ** Hangar Fenceline - E Side 03/10/2025 8 AM 25 Good Hangar Fenceline - N Center 03/10/2025 8 AM 18 Good Hangar Fenceline - N Corner 03/10/2025 8 AM 15 Good Hangar Fenceline - NE Corner 03/10/2025 8 AM ** ** Hangar Fenceline - NE Side 03/10/2025 8 AM 18 Good Hangar Fenceline - S Corner 03/10/2025 8 AM 20 Good Hangar Fenceline - S Side 03/10/2025 8 AM 20 Good Hangar Fenceline - SW Corner 03/10/2025 8 AM 24 Good Hangar Fenceline - SW Side 03/10/2025 8 AM 17 Good • •24-Hour Hangar Fenceline - W Side Period • • 03/10/2025 8 AM Particulate Matter 24 Level of Concern Good Legacy Road 03/10/2025 8 AM ** ** Moffett and Tustin Ranch 03/10/2025 8 AM 30 Good Valencia and Armstrong 03/10/2025 8 AM 6 Good Valencia and Columbus Square 03/10/2025 8 AM 18 Good Valencia and Legacy 03/10/2025 8 AM ** ** Victory and Tustin Ranch Rd. 03/10/2025 8 AM 15 Good Warner Avenue 03/10/2025 8 AM 17 Good Warner and Armstrong 03/10/2025 8 AM 15 Good Category Descriptions Color Green Good 0 to 54 Air quality is satisfactory, and air pollution poses little or no risk. Yellow Moderate 55 to 154 Air quality is acceptable. However, there may be a risk for some people, particularly those who are unusually sensitive to air pollution. Orange Unhealthy for Sensitive 155 to 254 Members of sensitive groups may Groups experience health effects. The general public is less likely to be affected. Red Unhealthy 255 to 354 Some members of the general public may experience health effects; members of sensitive groups may experience more serious health effects. Purple Very Unhealthy 355 to 424 Health alert: The risk of health effects is increased for everyone. Hazardous 425 to 504 Health warning of emergency - conditions: ever. . likely ..- affected. Tuesday, March 11, 2025 North Hangar Fire Incident I City of Tustin Air Quality Updates: Particulate Matter Air monitoring and sampling locations have been set up around the perimeter of the hangar and in surrounding communities to provide real-time information on Particulate Matter (PM) in the air. While the units are in place, an average reading for the last 24 hours will be provided for the public's reference. Any questions regarding these numbers should be directed to the call center at 714-426-2444. Monitoring Air Quality for Sensitive Individuals An environmental group contracted by the U.S. Navy is monitoring the air quality around the incident for any readings above 154 micrograms per cubic meter (ug/m3), which may cause individuals in sensitive groups to experience health effects. This is a moderate threshold that is less likely to affect the general public. What is Particulate Matter? "Particulate matter," also known as particle pollution or PM, is a complex mixture of extremely small particles and liquid droplets that exists in the environment including pollen, dust, and soil. Typical particulate matter for the area ranges from 3 to 67 ug/m3. The concentration range is based on sampling results collected by South Coast AQMD in Anaheim, CA, which was the closest available dataset in proximity to the site. For more information about air quality and monitoring, visit the AirNow website at www.airnow.gov. Good Moderate (0 to 54) (55 to 154) Unhealthyfor Wnhealthy Sensitive Groups (255 to Unhealthy EL(155 to 254)354) See below for further category descriptions. ** Data gap due to instrument malfunction Very Unhealthy Hazardous (355 to 424) (425-504) Location Columbus Square Park Period Ending 03/11/2025 8 AM Matter 13 Level of Concern Good Hangar Fenceline - E Side 03/11/2025 8 AM 18 Good Hangar Fenceline - N Center 03/11/2025 8 AM 14 Good Hangar Fenceline - N Corner 03/11/2025 8 AM 12 Good Hangar Fenceline - NE Corner 03/11/2025 8 AM 16 Good Hangar Fenceline - NE Side 03/11/2025 8 AM 14 Good Hangar Fenceline - S Corner 03/11/2025 8 AM ** ** Hangar Fenceline - S Side 03/11/2025 8 AM 17 Good Hangar Fenceline - SW Corner 03/11/2025 8 AM 21 Good Hangar Fenceline - SW Side 03/11/2025 8 AM 13 Good • •24-Hour Hangar Fenceline - W Side Period • • 03/11/2025 8 AM Particulate Matter 21 Level of Concern Good Legacy Road 03/11/2025 8 AM ** ** Moffett and Tustin Ranch 03/11/2025 8 AM 27 Good Valencia and Armstrong 03/11/2025 8 AM ** ** Valencia and Columbus Square 03/11/2025 8 AM 14 Good Valencia and Legacy 03/11/2025 8 AM 11 Good Victory and Tustin Ranch Rd. 03/11/2025 8 AM 12 Good Warner Avenue 03/11/2025 8 AM 12 Good Warner and Armstrong 03/11/2025 8 AM 12 Good Category Descriptions Color Green Good 0 to 54 Air quality is satisfactory, and air pollution poses little or no risk. Yellow Moderate 55 to 154 Air quality is acceptable. However, there may be a risk for some people, particularly those who are unusually sensitive to air pollution. Orange Unhealthy for Sensitive 155 to 254 Members of sensitive groups may Groups experience health effects. The general public is less likely to be affected. Red Unhealthy 255 to 354 Some members of the general public may experience health effects; members of sensitive groups may experience more serious health effects. Purple Very Unhealthy 355 to 424 Health alert: The risk of health effects is increased for everyone. Hazardous 425 to 504 Health warning of emergency - conditions: ever. . likely ..- affected. Wednesday, March 12, 2025 North Hangar Fire Incident I City of Tustin Air Quality Updates: Particulate Matter Air monitoring and sampling locations have been set up around the perimeter of the hangar and in surrounding communities to provide real-time information on Particulate Matter (PM) in the air. While the units are in place, an average reading for the last 24 hours will be provided for the public's reference. Any questions regarding these numbers should be directed to the call center at 714-426-2444. Monitoring Air Quality for Sensitive Individuals An environmental group contracted by the U.S. Navy is monitoring the air quality around the incident for any readings above 154 micrograms per cubic meter (ug/m3), which may cause individuals in sensitive groups to experience health effects. This is a moderate threshold that is less likely to affect the general public. What is Particulate Matter? "Particulate matter," also known as particle pollution or PM, is a complex mixture of extremely small particles and liquid droplets that exists in the environment including pollen, dust, and soil. Typical particulate matter for the area ranges from 3 to 67 ug/m3. The concentration range is based on sampling results collected by South Coast AQMD in Anaheim, CA, which was the closest available dataset in proximity to the site. For more information about air quality and monitoring, visit the AirNow website at www.airnow.gov. Good Moderate (0 to 54) (55 to 154) Unhealthyfor Wnhealthy Sensitive Groups (255 to Unhealthy EL(155 to 254)354) See below for further category descriptions. ** Data gap due to instrument malfunction Very Unhealthy Hazardous (355 to 424) (425-504) Location Columbus Square Park Period Ending 03/12/2025 8 AM Matter ** Level of Concern ** Hangar Fenceline - E Side 03/12/2025 8 AM 7 Good Hangar Fenceline - N Center 03/12/2025 8 AM 4 Good Hangar Fenceline - N Corner 03/12/2025 8 AM 3 Good Hangar Fenceline - NE Corner 03/12/2025 8 AM ** ** Hangar Fenceline - NE Side 03/12/2025 8 AM 4 Good Hangar Fenceline - S Corner 03/12/2025 8 AM 9 Good Hangar Fenceline - S Side 03/12/2025 8 AM 8 Good Hangar Fenceline - SW Corner 03/12/2025 8 AM 5 Good Hangar Fenceline - SW Side 03/12/2025 8 AM 3 Good • •24-Hour Hangar Fenceline - W Side Period • • 03/12/2025 8 AM Particulate Matter 16 Level of Concern Good Legacy Road 03/12/2025 8 AM ** ** Moffett and Tustin Ranch 03/12/2025 8 AM 18 Good Valencia and Armstrong 03/12/2025 8 AM ** ** Valencia and Columbus Square 03/12/2025 8 AM 4 Good Valencia and Legacy 03/12/2025 8 AM 3 Good Victory and Tustin Ranch Rd. 03/12/2025 8 AM 2 Good Warner Avenue 03/12/2025 8 AM 3 Good Warner and Armstrong 03/12/2025 8 AM 3 Good Category Descriptions Color Green Good 0 to 54 Air quality is satisfactory, and air pollution poses little or no risk. Yellow Moderate 55 to 154 Air quality is acceptable. However, there may be a risk for some people, particularly those who are unusually sensitive to air pollution. Orange Unhealthy for Sensitive 155 to 254 Members of sensitive groups may Groups experience health effects. The general public is less likely to be affected. Red Unhealthy 255 to 354 Some members of the general public may experience health effects; members of sensitive groups may experience more serious health effects. Purple Very Unhealthy 355 to 424 Health alert: The risk of health effects is increased for everyone. Hazardous 425 to 504 Health warning of emergency - conditions: ever. . likely ..- affected. Thursday, March 13, 2025 North Hangar Fire Incident I City of Tustin Air Quality Updates: Particulate Matter Air monitoring and sampling locations have been set up around the perimeter of the hangar and in surrounding communities to provide real-time information on Particulate Matter (PM) in the air. While the units are in place, an average reading for the last 24 hours will be provided for the public's reference. Any questions regarding these numbers should be directed to the call center at 714-426-2444. Monitoring Air Quality for Sensitive Individuals An environmental group contracted by the U.S. Navy is monitoring the air quality around the incident for any readings above 154 micrograms per cubic meter (ug/m3), which may cause individuals in sensitive groups to experience health effects. This is a moderate threshold that is less likely to affect the general public. What is Particulate Matter? "Particulate matter," also known as particle pollution or PM, is a complex mixture of extremely small particles and liquid droplets that exists in the environment including pollen, dust, and soil. Typical particulate matter for the area ranges from 3 to 67 ug/m3. The concentration range is based on sampling results collected by South Coast AQMD in Anaheim, CA, which was the closest available dataset in proximity to the site. For more information about air quality and monitoring, visit the AirNow website at www.airnow.gov. Good Moderate (0 to 54) (55 to 154) Unhealthyfor Wnhealthy Sensitive Groups (255 to Unhealthy EL(155 to 254)354) See below for further category descriptions. ** Data gap due to instrument malfunction Very Unhealthy Hazardous (355 to 424) (425-504) Location Columbus Square Park Period Ending 03/13/2025 8 AM Matter ** Level of Concern ** Hangar Fenceline - E Side 03/13/2025 8 AM 7 Good Hangar Fenceline - N Center 03/13/2025 8 AM 3 Good Hangar Fenceline - N Corner 03/13/2025 8 AM 3 Good Hangar Fenceline - NE Corner 03/13/2025 8 AM ** ** Hangar Fenceline - NE Side 03/13/2025 8 AM 3 Good Hangar Fenceline - S Corner 03/13/2025 8 AM 7 Good Hangar Fenceline - S Side 03/13/2025 8 AM ** ** Hangar Fenceline - SW Corner 03/13/2025 8 AM 4 Good Hangar Fenceline - SW Side 03/13/2025 8 AM 2 Good • •24-Hour Hangar Fenceline - W Side Period • • 03/13/2025 8 AM Particulate Matter ** Level of Concern ** Legacy Road 03/13/2025 8 AM 8 Good Moffett and Tustin Ranch 03/13/2025 8 AM 18 Good Valencia and Armstrong 03/13/2025 8 AM ** ** Valencia and Columbus Square 03/13/2025 8 AM ** ** Valencia and Legacy 03/13/2025 8 AM 2 Good Victory and Tustin Ranch Rd. 03/13/2025 8 AM 1 Good Warner Avenue 03/13/2025 8 AM ** ** Warner and Armstrong 03/13/2025 8 AM ** ** Category Descriptions Color Green Good 0 to 54 Air quality is satisfactory, and air pollution poses little or no risk. Yellow Moderate 55 to 154 Air quality is acceptable. However, there may be a risk for some people, particularly those who are unusually sensitive to air pollution. Orange Unhealthy for Sensitive 155 to 254 Members of sensitive groups may Groups experience health effects. The general public is less likely to be affected. Red Unhealthy 255 to 354 Some members of the general public may experience health effects; members of sensitive groups may experience more serious health effects. Purple Very Unhealthy 355 to 424 Health alert: The risk of health effects is increased for everyone. Hazardous 425 to 504 Health warning of emergency - conditions: ever. . likely ..- affected. Friday, March 14, 2025 North Hangar Fire Incident I City of Tustin Air Quality Updates: Particulate Matter Air monitoring and sampling locations have been set up around the perimeter of the hangar and in surrounding communities to provide real-time information on Particulate Matter (PM) in the air. While the units are in place, an average reading for the last 24 hours will be provided for the public's reference. Any questions regarding these numbers should be directed to the call center at 714-426-2444. Monitoring Air Quality for Sensitive Individuals An environmental group contracted by the U.S. Navy is monitoring the air quality around the incident for any readings above 154 micrograms per cubic meter (ug/m3), which may cause individuals in sensitive groups to experience health effects. This is a moderate threshold that is less likely to affect the general public. What is Particulate Matter? "Particulate matter," also known as particle pollution or PM, is a complex mixture of extremely small particles and liquid droplets that exists in the environment including pollen, dust, and soil. Typical particulate matter for the area ranges from 3 to 67 ug/m3. The concentration range is based on sampling results collected by South Coast AQMD in Anaheim, CA, which was the closest available dataset in proximity to the site. For more information about air quality and monitoring, visit the AirNow website at www.airnow.gov. Good Moderate (0 to 54) (55 to 154) Unhealthyfor Wnhealthy Sensitive Groups (255 to Unhealthy EL(155 to 254)354) See below for further category descriptions. ** Data gap due to instrument malfunction Very Unhealthy Hazardous (355 to 424) (425-504) Location Columbus Square Park Period Ending 03/14/2025 8 AM Matter 6 Level of Concern Good Hangar Fenceline - E Side 03/14/2025 8 AM 10 Good Hangar Fenceline - N Center 03/14/2025 8 AM 5 Good Hangar Fenceline - N Corner 03/14/2025 8 AM 5 Good Hangar Fenceline - NE Corner 03/14/2025 8 AM 6 Good Hangar Fenceline - NE Side 03/14/2025 8 AM 5 Good Hangar Fenceline - S Corner 03/14/2025 8 AM 9 Good Hangar Fenceline - S Side 03/14/2025 8 AM ** ** Hangar Fenceline - SW Corner 03/14/2025 8 AM 6 Good Hangar Fenceline - SW Side 03/14/2025 8 AM 2 Good • •24-Hour Hangar Fenceline - W Side Period • • 03/14/2025 8 AM Particulate Matter ** Level of Concern ** Legacy Road 03/14/2025 8 AM 17 Good Moffett and Tustin Ranch 03/14/2025 8 AM 20 Good Valencia and Armstrong 03/14/2025 8 AM ** ** Valencia and Columbus Square 03/14/2025 8 AM ** ** Valencia and Legacy 03/14/2025 8 AM 3 Good Victory and Tustin Ranch Rd. 03/14/2025 8 AM 2 Good Warner Avenue 03/14/2025 8 AM 4 Good Warner and Armstrong 03/14/2025 8 AM 3 Good Category Descriptions Color Green Good 0 to 54 Air quality is satisfactory, and air pollution poses little or no risk. Yellow Moderate 55 to 154 Air quality is acceptable. However, there may be a risk for some people, particularly those who are unusually sensitive to air pollution. Orange Unhealthy for Sensitive 155 to 254 Members of sensitive groups may Groups experience health effects. The general public is less likely to be affected. Red Unhealthy 255 to 354 Some members of the general public may experience health effects; members of sensitive groups may experience more serious health effects. Purple Very Unhealthy 355 to 424 Health alert: The risk of health effects is increased for everyone. Hazardous 425 to 504 Health warning of emergency - conditions: ever. . likely ..- affected. Saturday, March 15, 2025 North Hangar Fire Incident I City of Tustin Air Quality Updates: Particulate Matter Air monitoring and sampling locations have been set up around the perimeter of the hangar and in surrounding communities to provide real-time information on Particulate Matter (PM) in the air. While the units are in place, an average reading for the last 24 hours will be provided for the public's reference. Any questions regarding these numbers should be directed to the call center at 714-426-2444. Monitoring Air Quality for Sensitive Individuals An environmental group contracted by the U.S. Navy is monitoring the air quality around the incident for any readings above 154 micrograms per cubic meter (ug/m3), which may cause individuals in sensitive groups to experience health effects. This is a moderate threshold that is less likely to affect the general public. What is Particulate Matter? "Particulate matter," also known as particle pollution or PM, is a complex mixture of extremely small particles and liquid droplets that exists in the environment including pollen, dust, and soil. Typical particulate matter for the area ranges from 3 to 67 ug/m3. The concentration range is based on sampling results collected by South Coast AQMD in Anaheim, CA, which was the closest available dataset in proximity to the site. For more information about air quality and monitoring, visit the AirNow website at www.airnow.gov. Good Moderate Unhealthy for Unhealthy Very Unhealthy • • (0 to 54) (55 to 154) Sensitive Groups 155 to 254) (255 to 354) (355 to 424) (425-504) �( See below for further category descriptions. ** Data gap due to instrument malfunction Location Columbus Square Park 24-Hour Period Ending 03/15/2025 8 AM ** ** Hangar Fenceline - E Side 03/15/2025 8 AM 22 Good Hangar Fenceline - N Center 03/15/2025 8 AM 16 Good Hangar Fenceline - N Corner 03/15/2025 8 AM 11 Good Hangar Fenceline - NE Corner 03/15/2025 8 AM 14 Good Hangar Fenceline - NE Side 03/15/2025 8 AM 15 Good Hangar Fenceline - S Corner 03/15/2025 8 AM 14 Good Hangar Fenceline - S Side 03/15/2025 8 AM 17 Good Hangar Fenceline - SW Corner 03/15/2025 8 AM 19 Good Hangar Fenceline - SW Side 03/15/2025 8 AM 11 Good • •24-Hour Hangar Fenceline - W Side Period • • 03/15/2025 8 AM Particulate Matter 27 Level of Concern Good Legacy Road 03/15/2025 8 AM 36 Good Moffett and Tustin Ranch 03/15/2025 8 AM 27 Good Valencia and Armstrong 03/15/2025 8 AM ** ** Valencia and Columbus Square 03/15/2025 8 AM 16 Good Valencia and Legacy 03/15/2025 8 AM 10 Good Victory and Tustin Ranch Rd. 03/15/2025 8 AM 8 Good Warner Avenue 03/15/2025 8 AM 13 Good Warner and Armstrong 03/15/2025 8 AM ** ** Category Descriptions Color Green Good 0 to 54 Air quality is satisfactory, and air pollution poses little or no risk. Yellow Moderate 55 to 154 Air quality is acceptable. However, there may be a risk for some people, particularly those who are unusually sensitive to air pollution. Orange Unhealthy for Sensitive 155 to 254 Members of sensitive groups may Groups experience health effects. The general public is less likely to be affected. Red Unhealthy 255 to 354 Some members of the general public may experience health effects; members of sensitive groups may experience more serious health effects. Purple Very Unhealthy 355 to 424 Health alert: The risk of health effects is increased for everyone. Hazardous 425 to 504 Health warning of emergency - conditions: ever. . likely ..- affected. Sunday, March 16, 2025 North Hangar Fire Incident I City of Tustin Air Quality Updates: Particulate Matter Air monitoring and sampling locations have been set up around the perimeter of the hangar and in surrounding communities to provide real-time information on Particulate Matter (PM) in the air. While the units are in place, an average reading for the last 24 hours will be provided for the public's reference. Any questions regarding these numbers should be directed to the call center at 714-426-2444. Monitoring Air Quality for Sensitive Individuals An environmental group contracted by the U.S. Navy is monitoring the air quality around the incident for any readings above 154 micrograms per cubic meter (ug/m3), which may cause individuals in sensitive groups to experience health effects. This is a moderate threshold that is less likely to affect the general public. What is Particulate Matter? "Particulate matter," also known as particle pollution or PM, is a complex mixture of extremely small particles and liquid droplets that exists in the environment including pollen, dust, and soil. Typical particulate matter for the area ranges from 3 to 67 ug/m3. The concentration range is based on sampling results collected by South Coast AQMD in Anaheim, CA, which was the closest available dataset in proximity to the site. For more information about air quality and monitoring, visit the AirNow website at www.airnow.gov. Good Moderate (0 to 54) (55 to 154) Unhealthyfor Wnhealthy Sensitive Groups (255 to Unhealthy EL(155 to 254)354) See below for further category descriptions. ** Data gap due to instrument malfunction Very Unhealthy Hazardous (355 to 424) (425-504) Location Columbus Square Park Period Ending 03/16/2025 8 AM Matter ** Level of Concern ** Hangar Fenceline - E Side 03/16/2025 8 AM 18 Good Hangar Fenceline - N Center 03/16/2025 8 AM 13 Good Hangar Fenceline - N Corner 03/16/2025 8 AM ** ** Hangar Fenceline - NE Corner 03/16/2025 8 AM 14 Good Hangar Fenceline - NE Side 03/16/2025 8 AM ** ** Hangar Fenceline - S Corner 03/16/2025 8 AM 14 Good Hangar Fenceline - S Side 03/16/2025 8 AM 15 Good Hangar Fenceline - SW Corner 03/16/2025 8 AM 17 Good Hangar Fenceline - SW Side 03/16/2025 8 AM 10 Good • •24-Hour Hangar Fenceline - W Side Period • • 03/16/2025 8 AM Particulate Matter 25 Level of Concern Good Legacy Road 03/16/2025 8 AM 32 Good Moffett and Tustin Ranch 03/16/2025 8 AM 27 Good Valencia and Armstrong 03/16/2025 8 AM ** ** Valencia and Columbus Square 03/16/2025 8 AM 13 Good Valencia and Legacy 03/16/2025 8 AM 9 Good Victory and Tustin Ranch Rd. 03/16/2025 8 AM 7 Good Warner Avenue 03/16/2025 8 AM 12 Good Warner and Armstrong 03/16/2025 8 AM 11 Good Category Descriptions Color Green Good 0 to 54 Air quality is satisfactory, and air pollution poses little or no risk. Yellow Moderate 55 to 154 Air quality is acceptable. However, there may be a risk for some people, particularly those who are unusually sensitive to air pollution. Orange Unhealthy for Sensitive 155 to 254 Members of sensitive groups may Groups experience health effects. The general public is less likely to be affected. Red Unhealthy 255 to 354 Some members of the general public may experience health effects; members of sensitive groups may experience more serious health effects. Purple Very Unhealthy 355 to 424 Health alert: The risk of health effects is increased for everyone. Hazardous 425 to 504 Health warning of emergency - conditions: ever. . likely ..- affected. Monday, March 17, 2025 North Hangar Fire Incident I City of Tustin Air Quality Updates: Particulate Matter Air monitoring and sampling locations have been set up around the perimeter of the hangar and in surrounding communities to provide real-time information on Particulate Matter (PM) in the air. While the units are in place, an average reading for the last 24 hours will be provided for the public's reference. Any questions regarding these numbers should be directed to the call center at 714-426-2444. Monitoring Air Quality for Sensitive Individuals An environmental group contracted by the U.S. Navy is monitoring the air quality around the incident for any readings above 154 micrograms per cubic meter (ug/m3), which may cause individuals in sensitive groups to experience health effects. This is a moderate threshold that is less likely to affect the general public. What is Particulate Matter? "Particulate matter," also known as particle pollution or PM, is a complex mixture of extremely small particles and liquid droplets that exists in the environment including pollen, dust, and soil. Typical particulate matter for the area ranges from 3 to 67 ug/m3. The concentration range is based on sampling results collected by South Coast AQMD in Anaheim, CA, which was the closest available dataset in proximity to the site. For more information about air quality and monitoring, visit the AirNow website at www.airnow.gov. Good Moderate (0 to 54) (55 to 154) Unhealthyfor Wnhealthy Sensitive Groups (255 to Unhealthy EL(155 to 254)354) See below for further category descriptions. ** Data gap due to instrument malfunction Very Unhealthy Hazardous (355 to 424) (425-504) Location Columbus Square Park Period Ending 03/17/2025 8 AM Matter ** Level of Concern ** Hangar Fenceline - E Side 03/17/2025 8 AM 23 Good Hangar Fenceline - N Center 03/17/2025 8 AM 18 Good Hangar Fenceline - N Corner 03/17/2025 8 AM ** ** Hangar Fenceline - NE Corner 03/17/2025 8 AM 20 Good Hangar Fenceline - NE Side 03/17/2025 8 AM 15 Good Hangar Fenceline - S Corner 03/17/2025 8 AM 19 Good Hangar Fenceline - S Side 03/17/2025 8 AM 18 Good Hangar Fenceline - SW Corner 03/17/2025 8 AM 23 Good Hangar Fenceline - SW Side 03/17/2025 8 AM 14 Good • •24-Hour Hangar Fenceline - W Side Period • • 03/17/2025 8 AM Particulate Matter 25 Level of Concern Good Legacy Road 03/17/2025 8 AM 37 Good Moffett and Tustin Ranch 03/17/2025 8 AM 31 Good Valencia and Armstrong 03/17/2025 8 AM ** ** Valencia and Columbus Square 03/17/2025 8 AM 18 Good Valencia and Legacy 03/17/2025 8 AM 12 Good Victory and Tustin Ranch Rd. 03/17/2025 8 AM 10 Good Warner Avenue 03/17/2025 8 AM 16 Good Warner and Armstrong 03/17/2025 8 AM 15 Good Category Descriptions Color Green Good 0 to 54 Air quality is satisfactory, and air pollution poses little or no risk. Yellow Moderate 55 to 154 Air quality is acceptable. However, there may be a risk for some people, particularly those who are unusually sensitive to air pollution. Orange Unhealthy for Sensitive 155 to 254 Members of sensitive groups may Groups experience health effects. The general public is less likely to be affected. Red Unhealthy 255 to 354 Some members of the general public may experience health effects; members of sensitive groups may experience more serious health effects. Purple Very Unhealthy 355 to 424 Health alert: The risk of health effects is increased for everyone. Hazardous 425 to 504 Health warning of emergency - conditions: ever. . likely ..- affected. Tuesday, March 18, 2025 North Hangar Fire Incident I City of Tustin Air Quality Updates: Particulate Matter Air monitoring and sampling locations have been set up around the perimeter of the hangar and in surrounding communities to provide real-time information on Particulate Matter (PM) in the air. While the units are in place, an average reading for the last 24 hours will be provided for the public's reference. Any questions regarding these numbers should be directed to the call center at 714-426-2444. Monitoring Air Quality for Sensitive Individuals An environmental group contracted by the U.S. Navy is monitoring the air quality around the incident for any readings above 154 micrograms per cubic meter (ug/m3), which may cause individuals in sensitive groups to experience health effects. This is a moderate threshold that is less likely to affect the general public. What is Particulate Matter? "Particulate matter," also known as particle pollution or PM, is a complex mixture of extremely small particles and liquid droplets that exists in the environment including pollen, dust, and soil. Typical particulate matter for the area ranges from 3 to 67 ug/m3. The concentration range is based on sampling results collected by South Coast AQMD in Anaheim, CA, which was the closest available dataset in proximity to the site. For more information about air quality and monitoring, visit the AirNow website at www.airnow.gov. Good Moderate (0 to 54) (55 to 154) Unhealthyfor Wnhealthy Sensitive Groups (255 to Unhealthy EL(155 to 254)354) See below for further category descriptions. ** Data gap due to instrument malfunction Very Unhealthy Hazardous (355 to 424) (425-504) Location Columbus Square Park Period Ending 03/18/2025 8 AM Matter 16 Level of Concern Good Hangar Fenceline - E Side 03/18/2025 8 AM 19 Good Hangar Fenceline - N Center 03/18/2025 8 AM 14 Good Hangar Fenceline - N Corner 03/18/2025 8 AM 13 Good Hangar Fenceline - NE Corner 03/18/2025 8 AM ** ** Hangar Fenceline - NE Side 03/18/2025 8 AM 12 Good Hangar Fenceline - S Corner 03/18/2025 8 AM 16 Good Hangar Fenceline - S Side 03/18/2025 8 AM 16 Good Hangar Fenceline - SW Corner 03/18/2025 8 AM ** ** Hangar Fenceline - SW Side 03/18/2025 8 AM 9 Good • •24-Hour Hangar Fenceline - W Side Period • • 03/18/2025 8 AM Particulate Matter 26 Level of Concern Good Legacy Road 03/18/2025 8 AM 40 Good Moffett and Tustin Ranch 03/18/2025 8 AM 28 Good Valencia and Armstrong 03/18/2025 8 AM ** ** Valencia and Columbus Square 03/18/2025 8 AM 14 Good Valencia and Legacy 03/18/2025 8 AM 9 Good Victory and Tustin Ranch Rd. 03/18/2025 8 AM 7 Good Warner Avenue 03/18/2025 8 AM 12 Good Warner and Armstrong 03/18/2025 8 AM 14 Good Category Descriptions Color Green Good 0 to 54 Air quality is satisfactory, and air pollution poses little or no risk. Yellow Moderate 55 to 154 Air quality is acceptable. However, there may be a risk for some people, particularly those who are unusually sensitive to air pollution. Orange Unhealthy for Sensitive 155 to 254 Members of sensitive groups may Groups experience health effects. The general public is less likely to be affected. Red Unhealthy 255 to 354 Some members of the general public may experience health effects; members of sensitive groups may experience more serious health effects. Purple Very Unhealthy 355 to 424 Health alert: The risk of health effects is increased for everyone. Hazardous 425 to 504 Health warning of emergency - conditions: ever. . likely ..- affected. Wednesday, March 19, 2025 North Hangar Fire Incident I City of Tustin Air Quality Updates: Particulate Matter Air monitoring and sampling locations have been set up around the perimeter of the hangar and in surrounding communities to provide real-time information on Particulate Matter (PM) in the air. While the units are in place, an average reading for the last 24 hours will be provided for the public's reference. Any questions regarding these numbers should be directed to the call center at 714-426-2444. Monitoring Air Quality for Sensitive Individuals An environmental group contracted by the U.S. Navy is monitoring the air quality around the incident for any readings above 154 micrograms per cubic meter (ug/m3), which may cause individuals in sensitive groups to experience health effects. This is a moderate threshold that is less likely to affect the general public. What is Particulate Matter? "Particulate matter," also known as particle pollution or PM, is a complex mixture of extremely small particles and liquid droplets that exists in the environment including pollen, dust, and soil. Typical particulate matter for the area ranges from 3 to 67 ug/m3. The concentration range is based on sampling results collected by South Coast AQMD in Anaheim, CA, which was the closest available dataset in proximity to the site. For more information about air quality and monitoring, visit the AirNow website at www.airnow.gov. Good Moderate (0 to 54) (55 to 154) Unhealthyfor Wnhealthy Sensitive Groups (255 to Unhealthy EL(155 to 254)354) See below for further category descriptions. ** Data gap due to instrument malfunction Very Unhealthy Hazardous (355 to 424) (425-504) Location Columbus Square Park Period Ending 03/19/2025 8 AM Matter ** Level of Concern ** Hangar Fenceline - E Side 03/19/2025 8 AM 12 Good Hangar Fenceline - N Center 03/19/2025 8 AM 8 Good Hangar Fenceline - N Corner 03/19/2025 8 AM 7 Good Hangar Fenceline - NE Corner 03/19/2025 8 AM 8 Good Hangar Fenceline - NE Side 03/19/2025 8 AM ** ** Hangar Fenceline - S Corner 03/19/2025 8 AM 12 Good Hangar Fenceline - S Side 03/19/2025 8 AM 13 Good Hangar Fenceline - SW Corner 03/19/2025 8 AM 13 Good Hangar Fenceline - SW Side 03/19/2025 8 AM 6 Good • •24-Hour Hangar Fenceline - W Side Period • • 03/19/2025 8 AM Particulate Matter 22 Level of Concern Good Legacy Road 03/19/2025 8 AM 36 Good Moffett and Tustin Ranch 03/19/2025 8 AM 23 Good Valencia and Armstrong 03/19/2025 8 AM ** ** Valencia and Columbus Square 03/19/2025 8 AM 7 Good Valencia and Legacy 03/19/2025 8 AM 5 Good Victory and Tustin Ranch Rd. 03/19/2025 8 AM 4 Good Warner Avenue 03/19/2025 8 AM 7 Good Warner and Armstrong 03/19/2025 8 AM 11 Good Category Descriptions Color Green Good 0 to 54 Air quality is satisfactory, and air pollution poses little or no risk. Yellow Moderate 55 to 154 Air quality is acceptable. However, there may be a risk for some people, particularly those who are unusually sensitive to air pollution. Orange Unhealthy for Sensitive 155 to 254 Members of sensitive groups may Groups experience health effects. The general public is less likely to be affected. Red Unhealthy 255 to 354 Some members of the general public may experience health effects; members of sensitive groups may experience more serious health effects. Purple Very Unhealthy 355 to 424 Health alert: The risk of health effects is increased for everyone. Hazardous 425 to 504 Health warning of emergency - conditions: ever. . likely ..- affected. Thursday, March 20, 2025 North Hangar Fire Incident I City of Tustin Air Quality Updates: Particulate Matter Air monitoring and sampling locations have been set up around the perimeter of the hangar and in surrounding communities to provide real-time information on Particulate Matter (PM) in the air. While the units are in place, an average reading for the last 24 hours will be provided for the public's reference. Any questions regarding these numbers should be directed to the call center at 714-426-2444. Monitoring Air Quality for Sensitive Individuals An environmental group contracted by the U.S. Navy is monitoring the air quality around the incident for any readings above 154 micrograms per cubic meter (ug/m3), which may cause individuals in sensitive groups to experience health effects. This is a moderate threshold that is less likely to affect the general public. What is Particulate Matter? "Particulate matter," also known as particle pollution or PM, is a complex mixture of extremely small particles and liquid droplets that exists in the environment including pollen, dust, and soil. Typical particulate matter for the area ranges from 3 to 67 ug/m3. The concentration range is based on sampling results collected by South Coast AQMD in Anaheim, CA, which was the closest available dataset in proximity to the site. For more information about air quality and monitoring, visit the AirNow website at www.airnow.gov. Good Moderate (0 to 54) (55 to 154) Unhealthyfor Wnhealthy Sensitive Groups (255 to Unhealthy EL(155 to 254)354) See below for further category descriptions. ** Data gap due to instrument malfunction Very Unhealthy Hazardous (355 to 424) (425-504) Location Columbus Square Park Period Ending 03/20/2025 8 AM Matter 9 Level of Concern Good Hangar Fenceline - E Side 03/20/2025 8 AM 12 Good Hangar Fenceline - N Center 03/20/2025 8 AM 7 Good Hangar Fenceline - N Corner 03/20/2025 8 AM 7 Good Hangar Fenceline - NE Corner 03/20/2025 8 AM 9 Good Hangar Fenceline - NE Side 03/20/2025 8 AM 7 Good Hangar Fenceline - S Corner 03/20/2025 8 AM 13 Good Hangar Fenceline - S Side 03/20/2025 8 AM 12 Good Hangar Fenceline - SW Corner 03/20/2025 8 AM 12 Good Hangar Fenceline - SW Side 03/20/2025 8 AM 6 Good • •24-Hour Hangar Fenceline - W Side Period • • 03/20/2025 8 AM Particulate Matter 20 Level of Concern Good Legacy Road 03/20/2025 8 AM 29 Good Moffett and Tustin Ranch 03/20/2025 8 AM 24 Good Valencia and Armstrong 03/20/2025 8 AM ** ** Valencia and Columbus Square 03/20/2025 8 AM ** ** Valencia and Legacy 03/20/2025 8 AM 5 Good Victory and Tustin Ranch Rd. 03/20/2025 8 AM 5 Good Warner Avenue 03/20/2025 8 AM 9 Good Warner and Armstrong 03/20/2025 8 AM 12 Good Category Descriptions Color Green Good 0 to 54 Air quality is satisfactory, and air pollution poses little or no risk. Yellow Moderate 55 to 154 Air quality is acceptable. However, there may be a risk for some people, particularly those who are unusually sensitive to air pollution. Orange Unhealthy for Sensitive 155 to 254 Members of sensitive groups may Groups experience health effects. The general public is less likely to be affected. Red Unhealthy 255 to 354 Some members of the general public may experience health effects; members of sensitive groups may experience more serious health effects. Purple Very Unhealthy 355 to 424 Health alert: The risk of health effects is increased for everyone. Hazardous 425 to 504 Health warning of emergency - conditions: ever. . likely ..- affected. Friday, March 21, 2025 North Hangar Fire Incident I City of Tustin Air Quality Updates: Particulate Matter Air monitoring and sampling locations have been set up around the perimeter of the hangar and in surrounding communities to provide real-time information on Particulate Matter (PM) in the air. While the units are in place, an average reading for the last 24 hours will be provided for the public's reference. Any questions regarding these numbers should be directed to the call center at 714-426-2444. Monitoring Air Quality for Sensitive Individuals An environmental group contracted by the U.S. Navy is monitoring the air quality around the incident for any readings above 154 micrograms per cubic meter (ug/m3), which may cause individuals in sensitive groups to experience health effects. This is a moderate threshold that is less likely to affect the general public. What is Particulate Matter? "Particulate matter," also known as particle pollution or PM, is a complex mixture of extremely small particles and liquid droplets that exists in the environment including pollen, dust, and soil. Typical particulate matter for the area ranges from 3 to 67 ug/m3. The concentration range is based on sampling results collected by South Coast AQMD in Anaheim, CA, which was the closest available dataset in proximity to the site. For more information about air quality and monitoring, visit the AirNow website at www.airnow.gov. Good Moderate (0 to 54) (55 to 154) Unhealthyfor Wnhealthy Sensitive Groups (255 to Unhealthy EL(155 to 254)354) See below for further category descriptions. Very Unhealthy Hazardous (355 to 424) (425-504) Columbus Square Park PeriodLocation 24-Hour Ending 03/21/2025 8 AM Particulate Matter 12 Level of Concern Good Hangar Fenceline - E Side 03/21/2025 8 AM 15 Good Hangar Fenceline - N Center 03/21/2025 8 AM 11 Good Hangar Fenceline - N Corner 03/21/2025 8 AM 10 Good Hangar Fenceline - NE Corner 03/21/2025 8 AM 12 Good Hangar Fenceline - NE Side 03/21/2025 8 AM 10 Good Hangar Fenceline - S Corner 03/21/2025 8 AM 15 Good Hangar Fenceline - S Side 03/21/2025 8 AM 14 Good Hangar Fenceline - SW Corner 03/21/2025 8 AM 14 Good Hangar Fenceline - SW Side 03/21/2025 8 AM 8 Good • •24-Hour Hangar Fenceline - W Side Period • • 03/21/2025 8 AM Particulate Matter 23 Level of Concern Good Legacy Road 03/21/2025 8 AM 39 Good Moffett and Tustin Ranch 03/21/2025 8 AM 26 Good Valencia and Armstrong 03/21/2025 8 AM ** ** Valencia and Columbus Square 03/21/2025 8 AM 10 Good Valencia and Legacy 03/21/2025 8 AM 7 Good Victory and Tustin Ranch Rd. 03/21/2025 8 AM 6 Good Warner Avenue 03/21/2025 8 AM 9 Good Warner and Armstrong 03/21/2025 8 AM 14 Good Category Descriptions Color Green Good 0 to 54 Air quality is satisfactory, and air pollution poses little or no risk. Yellow Moderate 55 to 154 Air quality is acceptable. However, there may be a risk for some people, particularly those who are unusually sensitive to air pollution. Orange Unhealthy for Sensitive 155 to 254 Members of sensitive groups may Groups experience health effects. The general public is less likely to be affected. Red Unhealthy 255 to 354 Some members of the general public may experience health effects; members of sensitive groups may experience more serious health effects. Purple Very Unhealthy 355 to 424 Health alert: The risk of health effects is increased for everyone. Hazardous 425 to 504 Health warning of emergency - conditions: ever. . likely ..- affected. Saturday, March 22, 2025 North Hangar Fire Incident I City of Tustin Air Quality Updates: Particulate Matter Air monitoring and sampling locations have been set up around the perimeter of the hangar and in surrounding communities to provide real-time information on Particulate Matter (PM) in the air. While the units are in place, an average reading for the last 24 hours will be provided for the public's reference. Any questions regarding these numbers should be directed to the call center at 714-426-2444. Monitoring Air Quality for Sensitive Individuals An environmental group contracted by the U.S. Navy is monitoring the air quality around the incident for any readings above 154 micrograms per cubic meter (ug/m3), which may cause individuals in sensitive groups to experience health effects. This is a moderate threshold that is less likely to affect the general public. What is Particulate Matter? "Particulate matter," also known as particle pollution or PM, is a complex mixture of extremely small particles and liquid droplets that exists in the environment including pollen, dust, and soil. Typical particulate matter for the area ranges from 3 to 67 ug/m3. The concentration range is based on sampling results collected by South Coast AQMD in Anaheim, CA, which was the closest available dataset in proximity to the site. For more information about air quality and monitoring, visit the AirNow website at www.airnow.gov. Good Moderate Unhealthy for (155 to 254) �nhealthy Very Unhealthy ... (0 to 54) (55 to 154) Sensitive Groups (255 to 354) (355 to 424) 'On March 21, 2025, the U.S. Navy decreased the number of air monitoring stations at the hangar site based on review of historical air monitoring data and an overall abatement of 50% of the Hangar 1 footprint. See below for further category descriptions. ** Data gap due to instrument malfunction Location Columbus Square Park 24-Hour Period Ending 03/22/2025 8 AM Matter 15 Level of Concern Good Hangar Fenceline - E Side 03/22/2025 8 AM 18 Good Hangar Fenceline - N Center 03/22/2025 8 AM 13 Good Hangar Fenceline - N Corner 03/22/2025 8 AM 12 Good Hangar Fenceline - NE Corner 03/22/2025 8 AM 15 Good Hangar Fenceline - S Side 03/22/2025 8 AM 16 Good Hangar Fenceline - SW Corner 03/22/2025 8 AM 18 Good Hangar Fenceline - SW Side 03/22/2025 8 AM 9 Good Hangar Fenceline - W Side 03/22/2025 8 AM 24 Good Category Descriptions Color Green Good 0 to 54 Air quality is satisfactory, and air pollution poses little or no risk. Yellow Moderate 55 to 154 Air quality is acceptable. However, there may be a risk for some people, particularly those who are unusually sensitive to air pollution. Orange Unhealthy for Sensitive 155 to 254 Members of sensitive groups may Groups experience health effects. The general public is less likely to be affected. Red Unhealthy 255 to 354 Some members of the general public may experience health effects; members of sensitive groups may experience more serious health effects. Purple Very Unhealthy 355 to 424 Health alert: The risk of health effects is increased for everyone. azardous 425 to 504 Health warning of emergency conditions: ever. . - likely ..- affected. Sunday, March 23, 2025 North Hangar Fire Incident I City of Tustin Air Quality Updates: Particulate Matter Air monitoring and sampling locations have been set up around the perimeter of the hangar and in surrounding communities to provide real-time information on Particulate Matter (PM) in the air. While the units are in place, an average reading for the last 24 hours will be provided for the public's reference. Any questions regarding these numbers should be directed to the call center at 714-426-2444. Monitoring Air Quality for Sensitive Individuals An environmental group contracted by the U.S. Navy is monitoring the air quality around the incident for any readings above 154 micrograms per cubic meter (ug/m3), which may cause individuals in sensitive groups to experience health effects. This is a moderate threshold that is less likely to affect the general public. What is Particulate Matter? "Particulate matter," also known as particle pollution or PM, is a complex mixture of extremely small particles and liquid droplets that exists in the environment including pollen, dust, and soil. Typical particulate matter for the area ranges from 3 to 67 ug/m3. The concentration range is based on sampling results collected by South Coast AQMD in Anaheim, CA, which was the closest available dataset in proximity to the site. For more information about air quality and monitoring, visit the AirNow website at www.airnow.gov. Good Moderate (0 to 54) (55 to 154) Unhealthyfor Wnhealthy Sensitive Groups (255 to Unhealthy EL(155 to 254)354) See below for further category descriptions. ** Data gap due to instrument malfunction Very Unhealthy Hazardous (355 to 424) (425-504) Location Columbus Square Park Period Ending 03/23/2025 8 AM Matter 19 Level of Concern Good Hangar Fenceline - E Side 03/23/2025 8 AM 23 Good Hangar Fenceline - N Center 03/23/2025 8 AM 18 Good Hangar Fenceline - N Corner 03/23/2025 8 AM 15 Good Hangar Fenceline - NE Corner 03/23/2025 8 AM 19 Good Hangar Fenceline - S Side 03/23/2025 8 AM 17 Good Hangar Fenceline - SW Corner 03/23/2025 8 AM 23 Good Hangar Fenceline - SW Side 03/23/2025 8 AM ** ** Hangar Fenceline - W Side 03/23/2025 8 AM 25 Good Legacy Road 03/23/2025 8 AM 47 Good Category Descriptions Color Green Good 0 to 54 Air quality is satisfactory, and air pollution poses little or no risk. Yellow Moderate 55 to 154 Air quality is acceptable. However, there may be a risk for some people, particularly those who are unusually sensitive to air pollution. Orange Unhealthy for Sensitive 155 to 254 Members of sensitive groups may Groups experience health effects. The general public is less likely to be affected. Red Unhealthy 255 to 354 Some members of the general public may experience health effects; members of sensitive groups may experience more serious health effects. Purple Very Unhealthy 355 to 424 Health alert: The risk of health VIE effects is increased for everyone. 425 to 07.. emergency FM . . . everyone more likely ..- affected. Monday, March 24, 2025 North Hangar Fire Incident I City of Tustin Air Quality Updates: Particulate Matter Air monitoring and sampling locations have been set up around the perimeter of the hangar and in surrounding communities to provide real-time information on Particulate Matter (PM) in the air. While the units are in place, an average reading for the last 24 hours will be provided for the public's reference. Any questions regarding these numbers should be directed to the call center at 714-426-2444. Monitoring Air Quality for Sensitive Individuals An environmental group contracted by the U.S. Navy is monitoring the air quality around the incident for any readings above 154 micrograms per cubic meter (ug/m3), which may cause individuals in sensitive groups to experience health effects. This is a moderate threshold that is less likely to affect the general public. What is Particulate Matter? "Particulate matter," also known as particle pollution or PM, is a complex mixture of extremely small particles and liquid droplets that exists in the environment including pollen, dust, and soil. Typical particulate matter for the area ranges from 3 to 67 ug/m3. The concentration range is based on sampling results collected by South Coast AQMD in Anaheim, CA, which was the closest available dataset in proximity to the site. For more information about air quality and monitoring, visit the AirNow website at www.airnow.gov. Good Moderate (0 to 54) (55 to 154) Unhealthyfor Wnhealthy Sensitive Groups (255 to Unhealthy EL(155 to 254)354) See below for further category descriptions. ** Data gap due to instrument malfunction Very Unhealthy Hazardous (355 to 424) (425-504) Location Columbus Square Park Period Ending 03/24/2025 8 AM Matter 26 Level of Concern Good Hangar Fenceline - E Side 03/24/2025 8 AM 31 Good Hangar Fenceline - N Center 03/24/2025 8 AM 25 Good Hangar Fenceline - N Corner 03/24/2025 8 AM 20 Good Hangar Fenceline - NE Corner 03/24/2025 8 AM 25 Good Hangar Fenceline - S Side 03/24/2025 8 AM 22 Good Hangar Fenceline - SW Corner 03/24/2025 8 AM 32 Good Hangar Fenceline - SW Side 03/24/2025 8 AM 14 Good Hangar Fenceline - W Side 03/24/2025 8 AM 29 Good Legacy Road 03/24/2025 8 AM 62 Moderate Category Descriptions Color Green Good 0 to 54 Air quality is satisfactory, and air pollution poses little or no risk. Yellow Moderate 55 to 154 Air quality is acceptable. However, there may be a risk for some people, particularly those who are unusually sensitive to air pollution. Orange Unhealthy for Sensitive 155 to 254 Members of sensitive groups may Groups experience health effects. The general public is less likely to be affected. Red Unhealthy 255 to 354 Some members of the general public may experience health effects; members of sensitive groups may experience more serious health effects. Purple Very Unhealthy 355 to 424 Health alert: The risk of health effects is increased for everyone. 425 to 17• • - •- • • • • • - likely • be -• Tuesday, March 25, 2025 North Hangar Fire Incident I City of Tustin Air Quality Updates: Particulate Matter Air monitoring and sampling locations have been set up around the perimeter of the hangar and in surrounding communities to provide real-time information on Particulate Matter (PM) in the air. While the units are in place, an average reading for the last 24 hours will be provided for the public's reference. Any questions regarding these numbers should be directed to the call center at 714-426-2444. Monitoring Air Quality for Sensitive Individuals An environmental group contracted by the U.S. Navy is monitoring the air quality around the incident for any readings above 154 micrograms per cubic meter (ug/m3), which may cause individuals in sensitive groups to experience health effects. This is a moderate threshold that is less likely to affect the general public. What is Particulate Matter? "Particulate matter," also known as particle pollution or PM, is a complex mixture of extremely small particles and liquid droplets that exists in the environment including pollen, dust, and soil. Typical particulate matter for the area ranges from 3 to 67 ug/m3. The concentration range is based on sampling results collected by South Coast AQMD in Anaheim, CA, which was the closest available dataset in proximity to the site. For more information about air quality and monitoring, visit the AirNow website at www.airnow.gov. Good Moderate Unhealthy for Unhealthy Very Unhealthy • • (0 to 54) (55 to 154) Sensitive Groups 155 to 254) (255 to 354) (355 to 424) (425-504) �( See below for further category descriptions. ** Data gap due to instrument malfunction Location Columbus Square Park 24-Hour Period Ending 03/25/2025 8 AM 41 Good Hangar Fenceline - E Side 03/25/2025 8 AM 48 Good Hangar Fenceline - N Center 03/25/2025 8 AM 39 Good Hangar Fenceline - N Corner 03/25/2025 8 AM 32 Good Hangar Fenceline - NE Corner 03/25/2025 8 AM ** ** Hangar Fenceline - S Side 03/25/2025 8 AM 32 Good Hangar Fenceline - SW Corner 03/25/2025 8 AM 55 Moderate Hangar Fenceline - SW Side 03/25/2025 8 AM 25 Good Hangar Fenceline - W Side 03/25/2025 8 AM 37 Good Legacy Road 03/25/2025 8 AM 83 Moderate Category Descriptions Color Green Good 0 to 54 Air quality is satisfactory, and air pollution poses little or no risk. Yellow Moderate 55 to 154 Air quality is acceptable. However, there may be a risk for some people, particularly those who are unusually sensitive to air pollution. Orange Unhealthy for Sensitive 155 to 254 Members of sensitive groups may Groups experience health effects. The general public is less likely to be affected. Red Unhealthy 255 to 354 Some members of the general public may experience health effects; members of sensitive groups may experience more serious health effects. Purple Very Unhealthy 355 to 424 Health alert: The risk of health effects is increased for everyone. 425 to 17• • - •- • • • • • - likely • be -• Wednesday, March 26, 2025 North Hangar Fire Incident I City of Tustin Air Quality Updates: Particulate Matter Air monitoring and sampling locations have been set up around the perimeter of the hangar and in surrounding communities to provide real-time information on Particulate Matter (PM) in the air. While the units are in place, an average reading for the last 24 hours will be provided for the public's reference. Any questions regarding these numbers should be directed to the call center at 714-426-2444. Monitoring Air Quality for Sensitive Individuals An environmental group contracted by the U.S. Navy is monitoring the air quality around the incident for any readings above 154 micrograms per cubic meter (ug/m3), which may cause individuals in sensitive groups to experience health effects. This is a moderate threshold that is less likely to affect the general public. What is Particulate Matter? "Particulate matter," also known as particle pollution or PM, is a complex mixture of extremely small particles and liquid droplets that exists in the environment including pollen, dust, and soil. Typical particulate matter for the area ranges from 3 to 67 ug/m3. The concentration range is based on sampling results collected by South Coast AQMD in Anaheim, CA, which was the closest available dataset in proximity to the site. For more information about air quality and monitoring, visit the AirNow website at www.airnow.gov. Good Moderate (0 to 54) (55 to 154) Unhealthyfor Wnhealthy Sensitive Groups (255 to Unhealthy EL(155 to 254)354) See below for further category descriptions. ** Data gap due to instrument malfunction Very Unhealthy Hazardous (355 to 424) (425-504) Location Columbus Square Park Period Ending 03/26/2025 8 AM Matter 40 Level of Concern Good Hangar Fenceline - E Side 03/26/2025 8 AM 47 Good Hangar Fenceline - N Center 03/26/2025 8 AM 39 Good Hangar Fenceline - N Corner 03/26/2025 8 AM 32 Good Hangar Fenceline - NE Corner 03/26/2025 8 AM 40 Good Hangar Fenceline - S Side 03/26/2025 8 AM 36 Good Hangar Fenceline - SW Corner 03/26/2025 8 AM 64 Moderate Hangar Fenceline - SW Side 03/26/2025 8 AM 28 Good Hangar Fenceline - W Side 03/26/2025 8 AM 38 Good Legacy Road 03/26/2025 8 AM 91 Moderate Category Descriptions Color Green Good 0 to 54 Air quality is satisfactory, and air pollution poses little or no risk. Yellow Moderate 55 to 154 Air quality is acceptable. However, there may be a risk for some people, particularly those who are unusually sensitive to air pollution. Orange Unhealthy for Sensitive 155 to 254 Members of sensitive groups may Groups experience health effects. The general public is less likely to be affected. Red Unhealthy 255 to 354 Some members of the general public may experience health effects; members of sensitive groups may experience more serious health effects. Purple Very Unhealthy 355 to 424 Health alert: The risk of health effects is increased for everyone. 425 to 17• • - •- • • • • • - likely • be -• Fri, March 27, 2025 North Hangar Fire Incident I City of Tustin Air Quality Updates: Particulate Matter Air monitoring and sampling locations have been set up around the perimeter of the hangar and in surrounding communities to provide real-time information on Particulate Matter (PM) in the air. While the units are in place, an average reading for the last 24 hours will be provided for the public's reference. Any questions regarding these numbers should be directed to the call center at 714-426-2444. Monitoring Air Quality for Sensitive Individuals An environmental group contracted by the U.S. Navy is monitoring the air quality around the incident for any readings above 154 micrograms per cubic meter (ug/m3), which may cause individuals in sensitive groups to experience health effects. This is a moderate threshold that is less likely to affect the general public. What is Particulate Matter? "Particulate matter," also known as particle pollution or PM, is a complex mixture of extremely small particles and liquid droplets that exists in the environment including pollen, dust, and soil. Typical particulate matter for the area ranges from 3 to 67 ug/m3. The concentration range is based on sampling results collected by South Coast AQMD in Anaheim, CA, which was the closest available dataset in proximity to the site. For more information about air quality and monitoring, visit the AirNow website at www.airnow.gov. Good Moderate (0 to 54) (55 to 154) Unhealthyfor Wnhealthy Sensitive Groups (255 to Unhealthy EL(155 to 254)354) See below for further category descriptions. ** Data gap due to instrument malfunction Very Unhealthy Hazardous (355 to 424) (425-504) Location Columbus Square Park Period Ending 03/27/2025 8 AM Matter 9 Level of Concern Good Hangar Fenceline - E Side 03/27/2025 8 AM 12 Good Hangar Fenceline - N Center 03/27/2025 8 AM 8 Good Hangar Fenceline - N Corner 03/27/2025 8 AM 7 Good Hangar Fenceline - NE Corner 03/27/2025 8 AM 10 Good Hangar Fenceline - S Side 03/27/2025 8 AM 12 Good Hangar Fenceline - SW Corner 03/27/2025 8 AM 12 Good Hangar Fenceline - SW Side 03/27/2025 8 AM 5 Good Hangar Fenceline - W Side 03/27/2025 8 AM ** ** Legacy Road 03/27/2025 8 AM 11 Good Category Descriptions Color Green Good 0 to 54 Air quality is satisfactory, and air pollution poses little or no risk. Yellow Moderate 55 to 154 Air quality is acceptable. However, there may be a risk for some people, particularly those who are unusually sensitive to air pollution. Orange Unhealthy for Sensitive 155 to 254 Members of sensitive groups may Groups experience health effects. The general public is less likely to be affected. Red Unhealthy 255 to 354 Some members of the general public may experience health effects; members of sensitive groups may experience more serious health effects. Purple Very Unhealthy 355 to 424 Health alert: The risk of health VIE effects is increased for everyone. 425 to 07.. emergency FM . . . everyone more likely ..- affected. Friday, March 28, 2025 North Hangar Fire Incident I City of Tustin Air Quality Updates: Particulate Matter Air monitoring and sampling locations have been set up around the perimeter of the hangar and in surrounding communities to provide real-time information on Particulate Matter (PM) in the air. While the units are in place, an average reading for the last 24 hours will be provided for the public's reference. Any questions regarding these numbers should be directed to the call center at 714-426-2444. Monitoring Air Quality for Sensitive Individuals An environmental group contracted by the U.S. Navy is monitoring the air quality around the incident for any readings above 154 micrograms per cubic meter (ug/m3), which may cause individuals in sensitive groups to experience health effects. This is a moderate threshold that is less likely to affect the general public. What is Particulate Matter? "Particulate matter," also known as particle pollution or PM, is a complex mixture of extremely small particles and liquid droplets that exists in the environment including pollen, dust, and soil. Typical particulate matter for the area ranges from 3 to 67 ug/m3. The concentration range is based on sampling results collected by South Coast AQMD in Anaheim, CA, which was the closest available dataset in proximity to the site. For more information about air quality and monitoring, visit the AirNow website at www.airnow.gov. Good Moderate Unhealthy for Unhealthy Very Unhealthy • • (0 to 54) (55 to 154) Sensitive Groups 155 to 254) (255 to 354) (355 to 424) (425-504) �( See below for further category descriptions. ** Data gap due to instrument malfunction Location Columbus Square Park 24-Hour Period Ending 03/28/2025 8 AM 11 Good Hangar Fenceline - E Side 03/28/2025 8 AM 13 Good Hangar Fenceline - N Center 03/28/2025 8 AM 9 Good Hangar Fenceline - N Corner 03/28/2025 8 AM 8 Good Hangar Fenceline - NE Corner 03/28/2025 8 AM 11 Good Hangar Fenceline - S Side 03/28/2025 8 AM 12 Good Hangar Fenceline - SW Corner 03/28/2025 8 AM 14 Good Hangar Fenceline - SW Side 03/28/2025 8 AM 6 Good Hangar Fenceline - W Side 03/28/2025 8 AM ** ** Legacy Road 03/28/2025 8 AM 7 Good Category Descriptions Color Green Good 0 to 54 Air quality is satisfactory, and air pollution poses little or no risk. Yellow Moderate 55 to 154 Air quality is acceptable. However, there may be a risk for some people, particularly those who are unusually sensitive to air pollution. Orange Unhealthy for Sensitive 155 to 254 Members of sensitive groups may Groups experience health effects. The general public is less likely to be affected. Red Unhealthy 255 to 354 Some members of the general public may experience health effects; members of sensitive groups may experience more serious health effects. Purple Very Unhealthy 355 to 424 Health alert: The risk of health VIE effects is increased for everyone. 425 to 07.. emergency FM . . . everyone more likely ..- affected. Saturday, March 29, 2025 North Hangar Fire Incident I City of Tustin Air Quality Updates: Particulate Matter Air monitoring and sampling locations have been set up around the perimeter of the hangar and in surrounding communities to provide real-time information on Particulate Matter (PM) in the air. While the units are in place, an average reading for the last 24 hours will be provided for the public's reference. Any questions regarding these numbers should be directed to the call center at 714-426-2444. Monitoring Air Quality for Sensitive Individuals An environmental group contracted by the U.S. Navy is monitoring the air quality around the incident for any readings above 154 micrograms per cubic meter (ug/m3), which may cause individuals in sensitive groups to experience health effects. This is a moderate threshold that is less likely to affect the general public. What is Particulate Matter? "Particulate matter," also known as particle pollution or PM, is a complex mixture of extremely small particles and liquid droplets that exists in the environment including pollen, dust, and soil. Typical particulate matter for the area ranges from 3 to 67 ug/m3. The concentration range is based on sampling results collected by South Coast AQMD in Anaheim, CA, which was the closest available dataset in proximity to the site. For more information about air quality and monitoring, visit the AirNow website at www.airnow.gov. Good Moderate (0 to 54) (55 to 154) Unhealthyfor Wnhealthy Sensitive Groups (255 to Unhealthy EL(155 to 254)354) See below for further category descriptions. Very Unhealthy Hazardous (355 to 424) (425-504) Columbus Square Park PeriodLocation 24-Hour Ending 03/29/2025 8 AM Particulate Matter 16 Level of Concern Good Hangar Fenceline - E Side 03/29/2025 8 AM 18 Good Hangar Fenceline - N Center 03/29/2025 8 AM 14 Good Hangar Fenceline - N Corner 03/29/2025 8 AM 12 Good Hangar Fenceline - NE Corner 03/29/2025 8 AM 15 Good Hangar Fenceline - S Side 03/29/2025 8 AM 15 Good Hangar Fenceline - SW Corner 03/29/2025 8 AM 17 Good Hangar Fenceline - SW Side 03/29/2025 8 AM 8 Good Hangar Fenceline - W Side 03/29/2025 8 AM 27 Good Legacy Road 03/29/2025 8 AM 10 Good Category Descriptions Color Green Good 0 to 54 Air quality is satisfactory, and air pollution poses little or no risk. Yellow Moderate 55 to 154 Air quality is acceptable. However, there may be a risk for some people, particularly those who are unusually sensitive to air pollution. Orange Unhealthy for Sensitive 155 to 254 Members of sensitive groups may Groups experience health effects. The general public is less likely to be affected. Red Unhealthy 255 to 354 Some members of the general public may experience health effects; members of sensitive groups may experience more serious health effects. Purple Very Unhealthy 355 to 424 Health alert: The risk of health VIE effects is increased for everyone. 425 to 07.. emergency FM . . . everyone more likely ..- affected. Sunday, March 30, 2025 North Hangar Fire Incident I City of Tustin Air Quality Updates: Particulate Matter Air monitoring and sampling locations have been set up around the perimeter of the hangar and in surrounding communities to provide real-time information on Particulate Matter (PM) in the air. While the units are in place, an average reading for the last 24 hours will be provided for the public's reference. Any questions regarding these numbers should be directed to the call center at 714-426-2444. Monitoring Air Quality for Sensitive Individuals An environmental group contracted by the U.S. Navy is monitoring the air quality around the incident for any readings above 154 micrograms per cubic meter (ug/m3), which may cause individuals in sensitive groups to experience health effects. This is a moderate threshold that is less likely to affect the general public. What is Particulate Matter? "Particulate matter," also known as particle pollution or PM, is a complex mixture of extremely small particles and liquid droplets that exists in the environment including pollen, dust, and soil. Typical particulate matter for the area ranges from 3 to 67 ug/m3. The concentration range is based on sampling results collected by South Coast AQMD in Anaheim, CA, which was the closest available dataset in proximity to the site. For more information about air quality and monitoring, visit the AirNow website at www.airnow.gov. Good Moderate (0 to 54) (55 to 154) Unhealthyfor Wnhealthy Sensitive Groups (255 to Unhealthy EL(155 to 254)354) See below for further category descriptions. ** Data gap due to instrument malfunction Very Unhealthy Hazardous (355 to 424) (425-504) Location Columbus Square Park Period Ending 03/30/2025 8 AM Matter 12 Level of Concern Good Hangar Fenceline - E Side 03/30/2025 8 AM 15 Good Hangar Fenceline - N Center 03/30/2025 8 AM 11 Good Hangar Fenceline - N Corner 03/30/2025 8 AM 10 Good Hangar Fenceline - NE Corner 03/30/2025 8 AM 12 Good Hangar Fenceline - S Side 03/30/2025 8 AM 13 Good Hangar Fenceline - SW Corner 03/30/2025 8 AM 14 Good Hangar Fenceline - SW Side 03/30/2025 8 AM 7 Good Hangar Fenceline - W Side 03/30/2025 8 AM ** ** Legacy Road 03/30/2025 8 AM 8 Good Category Descriptions Color Green Good 0 to 54 Air quality is satisfactory, and air pollution poses little or no risk. Yellow Moderate 55 to 154 Air quality is acceptable. However, there may be a risk for some people, particularly those who are unusually sensitive to air pollution. Orange Unhealthy for Sensitive 155 to 254 Members of sensitive groups may Groups experience health effects. The general public is less likely to be affected. Red Unhealthy 255 to 354 Some members of the general public may experience health effects; members of sensitive groups may experience more serious health effects. Purple Very Unhealthy 355 to 424 Health alert: The risk of health VIE effects is increased for everyone. 425 to 07.. emergency FM . . . everyone more likely ..- affected. Monday, March 31, 2025 North Hangar Fire Incident I City of Tustin Air Quality Updates: Particulate Matter Air monitoring and sampling locations have been set up around the perimeter of the hangar and in surrounding communities to provide real-time information on Particulate Matter (PM) in the air. While the units are in place, an average reading for the last 24 hours will be provided for the public's reference. Any questions regarding these numbers should be directed to the call center at 714-426-2444. Monitoring Air Quality for Sensitive Individuals An environmental group contracted by the U.S. Navy is monitoring the air quality around the incident for any readings above 154 micrograms per cubic meter (ug/m3), which may cause individuals in sensitive groups to experience health effects. This is a moderate threshold that is less likely to affect the general public. What is Particulate Matter? "Particulate matter," also known as particle pollution or PM, is a complex mixture of extremely small particles and liquid droplets that exists in the environment including pollen, dust, and soil. Typical particulate matter for the area ranges from 3 to 67 ug/m3. The concentration range is based on sampling results collected by South Coast AQMD in Anaheim, CA, which was the closest available dataset in proximity to the site. For more information about air quality and monitoring, visit the AirNow website at www.airnow.gov. Good Moderate (0 to 54) (55 to 154) Unhealthyfor Wnhealthy Sensitive Groups (255 to Unhealthy EL(155 to 254)354) See below for further category descriptions. ** Data gap due to instrument malfunction Very Unhealthy Hazardous (355 to 424) (425-504) Location Columbus Square Park Period Ending 03/31/2025 8 AM Matter 8 Level of Concern Good Hangar Fenceline - E Side 03/31/2025 8 AM 10 Good Hangar Fenceline - N Center 03/31/2025 8 AM 7 Good Hangar Fenceline - N Corner 03/31/2025 8 AM 6 Good Hangar Fenceline - NE Corner 03/31/2025 8 AM 9 Good Hangar Fenceline - S Side 03/31/2025 8 AM ** ** Hangar Fenceline - SW Corner 03/31/2025 8 AM 9 Good Hangar Fenceline - SW Side 03/31/2025 8 AM 5 Good Hangar Fenceline - W Side 03/31/2025 8 AM 5 Good Legacy Road 03/31/2025 8 AM 5 Good Category Descriptions Color Green Good 0 to 54 Air quality is satisfactory, and air pollution poses little or no risk. Yellow Moderate 55 to 154 Air quality is acceptable. However, there may be a risk for some people, particularly those who are unusually sensitive to air pollution. Orange Unhealthy for Sensitive 155 to 254 Members of sensitive groups may Groups experience health effects. The general public is less likely to be affected. Red Unhealthy 255 to 354 Some members of the general public may experience health effects; members of sensitive groups may experience more serious health effects. Purple Very Unhealthy 355 to 424 Health alert: The risk of health effects is increased for everyone. 425 to 17• • - •- • • • • • - likely • be -•