EPA Air · stack tests by state, industry and year

NAICS 9999: stack tests in California, 2023

• 322Stack tests

A stack test measures what a source actually emits, at the stack, against the limit in its permit. Each row is one stack test recorded during 2023 at a California source whose primary industry code is NAICS 9999. A facility filing more than one industry code is counted under the first one on its record.

NAICS 9999 in California, other years

• 2026 50
• 2025 193
• 2024 715
• 2022 499
• 2021 1,017
• 2020 255
• 2019 290
• 2018 249
• 2017 558

Other industries in California, 2023

• Utilities (NAICS 2211) 2,798
• Oil and gas extraction (NAICS 2111) 2,583
• Nonmetallic mineral product manufacturing (NAICS 3272) 362
• Food manufacturing (NAICS 3114) 203
• Waste management and remediation (NAICS 5622) 188
• Petroleum and coal products manufacturing (NAICS 3241) 135
• Beverage and tobacco manufacturing (NAICS 3121) 134
• Food manufacturing (NAICS 3119) 112
• Pipeline transportation (NAICS 4862) 85
• Executive and legislative government (NAICS 9211) 82
• Merchant wholesalers, nondurable goods (NAICS 4247) 75
• Food manufacturing (NAICS 3115) 67
• Utilities (NAICS 2213) 60
• Hospitals (NAICS 6221) 37
• Chemical manufacturing (NAICS 3253) 37
• Pipeline transportation (NAICS 4861) 30
• Food manufacturing (NAICS 3116) 30
• Fabricated metal product manufacturing (NAICS 3324) 26
• Plastics and rubber products manufacturing (NAICS 3261) 26
• Merchant wholesalers, nondurable goods (NAICS 4244) 24
• Food manufacturing (NAICS 3111) 18
• Paper manufacturing (NAICS 3222) 18
• Nonmetallic mineral product manufacturing (NAICS 3279) 17
• Animal production (NAICS 1121) 16
• Primary metal manufacturing (NAICS 3314) 15
• NAICS 4523 12
• Educational services (NAICS 6113) 12
• Fabricated metal product manufacturing (NAICS 3321) 10
• Administration of environmental programs (NAICS 9241) 10
• Mining and quarrying (NAICS 2123) 9
• Chemical manufacturing (NAICS 3251) 9
• National security and international affairs (NAICS 9281) 8
• Fabricated metal product manufacturing (NAICS 3323) 8
• Waste management and remediation (NAICS 5629) 8
• NAICS 4543 7
• Food manufacturing (NAICS 3118) 7
• Transportation equipment manufacturing (NAICS 3364) 6
• Nonmetallic mineral product manufacturing (NAICS 3273) 6
• Primary metal manufacturing (NAICS 3313) 6
• Furniture and related product manufacturing (NAICS 3372) 5
• Chemical manufacturing (NAICS 3252) 4
• Fabricated metal product manufacturing (NAICS 3328) 4
• Waste management and remediation (NAICS 5621) 4
• Nonmetallic mineral product manufacturing (NAICS 3274) 4
• Ambulatory health care services (NAICS 6216) 4
• Nonmetallic mineral product manufacturing (NAICS 3271) 3
• Food manufacturing (NAICS 3112) 3
• Printing and related support (NAICS 3231) 3

Air-emissions stack tests recorded in California, 2023

Primary NAICS code as filed on the facility record; dates as filed by the agency that recorded the stack test. Figures from EPA’s ICIS-AIR download.