EPA Air · stack tests by county and year

Air-emissions stack tests in Stanislaus County, California, 2025

• 579Stack tests

A stack test measures what a source actually emits, at the stack, against the limit in its permit. Each row below is one stack test recorded against a source in Stanislaus County, California during 2025. A facility can appear several times: this is the year’s record of what happened, not a list of places. The sources themselves are on the Stanislaus County facility page.

Stanislaus County, California, 2025

• Inspections 176

Air-emissions stack tests in Stanislaus County, other years

• 2026 246
• 2024 3,977
• 2023 595
• 2022 627
• 2021 1,917
• 2020 846
• 2019 349
• 2018 548
• 2017 382

Air-emissions stack tests recorded in Stanislaus County, California, 2025

Dates as filed by the agency that recorded the stack test. Figures from EPA’s ICIS-AIR download.