Accepting comments from January 21, 2026, through February 20, 2026.
The Idaho Department of Environmental Quality (DEQ) seeks comment on a draft Tier II operating permit renewal for onsemi.
onsemi manufactures semiconductor devices (i.e., chips) on silicon wafers in a facility in Nampa, Idaho. The company is seeking to renew its modified Tier II operating permit for air pollution emissions from various manufacturing processes, including semiconductor development operations, boilers, emergency stationary CI engines, cooling towers, and other miscellaneous sources. DEQ issued a Tier II operating permit for onsemi (then known as ON Semiconductor) in 2018. The proposed permit includes a facility emissions cap.
DEQ has determined that operation according to the proposed permit will not cause or significantly contribute to a violation of any ambient air quality standard and will not injure or unreasonably affect human or animal life or vegetation. DEQ has reviewed the application and completed an analysis of the information submitted by the applicant to amend the mercury testing schedule and renew the Tier II operating permit. Based on this analysis, DEQ proposes to issue the Tier II operating permit to onsemi.
The draft permit materials are available for public review at DEQ’s State Office (1410 N. Hilton St.) and on DEQ’s website. Written comments on the draft permit and supporting materials will be accepted through December 12, 2025, at 5 p.m. MT. Submit comments using the form below or via mail or email to:
Dianne Hobbs
1410 N. Hilton St.
Boise, ID 83706
dianne.hobbs@deq.idaho.gov
For technical assistance on questions concerning this project or the permitting process, contact Nachammai Vairavan at (208) 373-0502 or nachammai.vairavan@deq.idaho.gov.
Related Documents
Permit Materials
Accessibility Services: The Idaho Department of Environmental Quality will provide reasonable language access services and/or disability services for documents at no charge. To request an accommodation under Title VI of the Civil Rights Act of 1964 or Americans with Disabilities Act, contact DEQ’s nondiscrimination coordinator at (208) 373-0271 or accessibility@deq.idaho.gov. Para obtener información en español, visite https://www.deq.idaho.gov/about-us/accessibility/.
Official Government Website
DEQ seeks comment on draft Tier II operating permit renewal for onsemi
Accepting comments from January 21, 2026, through February 20, 2026.
The Idaho Department of Environmental Quality (DEQ) seeks comment on a draft Tier II operating permit renewal for onsemi.
onsemi manufactures semiconductor devices (i.e., chips) on silicon wafers in a facility in Nampa, Idaho. The company is seeking to renew its modified Tier II operating permit for air pollution emissions from various manufacturing processes, including semiconductor development operations, boilers, emergency stationary CI engines, cooling towers, and other miscellaneous sources. DEQ issued a Tier II operating permit for onsemi (then known as ON Semiconductor) in 2018. The proposed permit includes a facility emissions cap.
DEQ has determined that operation according to the proposed permit will not cause or significantly contribute to a violation of any ambient air quality standard and will not injure or unreasonably affect human or animal life or vegetation. DEQ has reviewed the application and completed an analysis of the information submitted by the applicant to amend the mercury testing schedule and renew the Tier II operating permit. Based on this analysis, DEQ proposes to issue the Tier II operating permit to onsemi.
The draft permit materials are available for public review at DEQ’s State Office (1410 N. Hilton St.) and on DEQ’s website. Written comments on the draft permit and supporting materials will be accepted through December 12, 2025, at 5 p.m. MT. Submit comments using the form below or via mail or email to:
Dianne Hobbs
1410 N. Hilton St.
Boise, ID 83706
dianne.hobbs@deq.idaho.gov
For technical assistance on questions concerning this project or the permitting process, contact Nachammai Vairavan at (208) 373-0502 or nachammai.vairavan@deq.idaho.gov.
Related Documents
Permit Materials
Accessibility Services: The Idaho Department of Environmental Quality will provide reasonable language access services and/or disability services for documents at no charge. To request an accommodation under Title VI of the Civil Rights Act of 1964 or Americans with Disabilities Act, contact DEQ’s nondiscrimination coordinator at (208) 373-0271 or accessibility@deq.idaho.gov. Para obtener información en español, visite https://www.deq.idaho.gov/about-us/accessibility/.
Public Comment Form