EPA Air · stack tests by state and year
Air-emissions stack tests in Washington, 2026
- 46Stack tests
A stack test measures what a source actually emits, at the stack, against the limit in its permit. Every stack test below was recorded against a source in Washington during 2026; one facility can appear more than once, because this is a record of what happened rather than a list of places.
Counties in Washington, 2026
Washington, other years
Air-emissions stack tests recorded in Washington, 2026
| Date | Facility | Where | Kind | Agency |
|---|---|---|---|---|
| 2026-07-29 | SIERRA PACIFIC INDUSTRIES - COGENERATION — high-priority violation on file | ABERDEEN, Grays Harbor, WA | Pending | Local |
| 2026-07-08 | PANELTECH — high-priority violation on file | HOQUIAM, Grays Harbor, WA | Pending | Local |
| 2026-06-03 | LANXESS CORPORATION — high-priority violation on file | KALAMA, Cowlitz, WA | Pass | Local |
| 2026-05-27 | CENTRIO (WESTERN) | SEATTLE, King, WA | Pass | Local |
| 2026-05-12 | NIPPON DYNAWAVE PACKAGING COMPANY LLC — high-priority violation on file | LONGVIEW, Cowlitz, WA | Pass | State |
| 2026-03-24 | NIPPON DYNAWAVE PACKAGING COMPANY LLC — high-priority violation on file | LONGVIEW, Cowlitz, WA | Pass | State |
| 2026-03-18 | HAMPTON LUMBER MILLS-WASHINGTON INC | DARRINGTON, Snohomish, WA | Pass | Local |
| 2026-03-18 | HAMPTON LUMBER MILLS-WASHINGTON INC | DARRINGTON, Snohomish, WA | Pass | Local |
| 2026-03-18 | HAMPTON LUMBER MILLS-WASHINGTON INC | DARRINGTON, Snohomish, WA | Pass | Local |
| 2026-03-18 | HAMPTON LUMBER MILLS-WASHINGTON INC | DARRINGTON, Snohomish, WA | Pass | Local |
| 2026-03-12 | VULCAN METALS CORP | TACOMA, Pierce, WA | Pass | Local |
| 2026-03-06 | PORT TOWNSEND PAPER CORPORATION — high-priority violation on file | PORT TOWNSEND, Jefferson, WA | Pass | State |
| 2026-03-05 | PORT TOWNSEND PAPER CORPORATION — high-priority violation on file | PORT TOWNSEND, Jefferson, WA | Pass | State |
| 2026-03-05 | PORT TOWNSEND PAPER CORPORATION — high-priority violation on file | PORT TOWNSEND, Jefferson, WA | Pass | State |
| 2026-03-04 | WESTROCK LONGVIEW LLC — high-priority violation on file | LONGVIEW, Cowlitz, WA | Pass | State |
| 2026-03-03 | WESTROCK LONGVIEW LLC — high-priority violation on file | LONGVIEW, Cowlitz, WA | Pass | State |
| 2026-03-03 | PHILLIPS 66 | FERNDALE, Whatcom, WA | Pass | Local |
| 2026-03-03 | BP WEST COAST PRODUCTS LLC — high-priority violation on file | BLAINE, Whatcom, WA | Pass | Local |
| 2026-03-02 | PORT TOWNSEND PAPER CORPORATION — high-priority violation on file | PORT TOWNSEND, Jefferson, WA | Pass | State |
| 2026-02-26 | TESORO REFINING AND MARKETING COMPANY | ANACORTES, Skagit, WA | Pass | Local |
| 2026-02-25 | TESORO REFINING AND MARKETING COMPANY | ANACORTES, Skagit, WA | Pass | Local |
| 2026-02-24 | TESORO REFINING AND MARKETING COMPANY | ANACORTES, Skagit, WA | Pass | Local |
| 2026-02-24 | CARDINAL FG COMPANY | WINLOCK, Lewis, WA | Pass | Local |
| 2026-02-20 | CEDAR GROVE COMPOST CO | MAPLE VALLEY, King, WA | Pass | Local |
| 2026-02-20 | CEDAR GROVE COMPOST CO | MAPLE VALLEY, King, WA | Pass | Local |
| 2026-02-18 | WESTROCK LONGVIEW LLC — high-priority violation on file | LONGVIEW, Cowlitz, WA | Pass | State |
| 2026-02-18 | BOISE CASCADE PLYWD | KETTLE FALLS, Stevens, WA | Pass | State |
| 2026-02-17 | WESTROCK LONGVIEW LLC — high-priority violation on file | LONGVIEW, Cowlitz, WA | Pass | State |
| 2026-02-17 | WESTROCK LONGVIEW LLC — high-priority violation on file | LONGVIEW, Cowlitz, WA | Pass | State |
| 2026-02-17 | STEELSCAPE, LC | WASHINGTON, Undetermined, WA | Pass | Local |
| 2026-02-13 | WESTROCK LONGVIEW LLC — high-priority violation on file | LONGVIEW, Cowlitz, WA | Pass | State |
| 2026-02-12 | WESTROCK LONGVIEW LLC — high-priority violation on file | LONGVIEW, Cowlitz, WA | Pass | State |
| 2026-02-12 | PUGET SOUND ENERGY (WA NATURAL GAS) | CHEHALIS, Lewis, WA | Pass | Local |
| 2026-02-11 | WESTROCK LONGVIEW LLC — high-priority violation on file | LONGVIEW, Cowlitz, WA | Pass | State |
| 2026-02-11 | PUGET SOUND ENERGY (WA NATURAL GAS) | CHEHALIS, Lewis, WA | Pass | Local |
| 2026-02-10 | WESTROCK LONGVIEW LLC — high-priority violation on file | LONGVIEW, Cowlitz, WA | Pass | State |
| 2026-02-10 | DYNO BATTERY INC. | SEATTLE, King, WA | Pass | Local |
| 2026-02-10 | DYNO BATTERY INC. | SEATTLE, King, WA | Pass | Local |
| 2026-02-09 | CEDAR GROVE COMPOSTING, INC | EVERETT, Snohomish, WA | Fail | Local |
| 2026-01-28 | AQUATIC CO | YELM, Thurston, WA | Pass | Local |
| 2026-01-28 | GAS TRANSMISSION NORTHWEST, LLC | WASHINGTON, Undetermined, WA | Pass | Local |
| 2026-01-28 | MINT FARM GENERATION, LLC. | LONGVIEW, Cowlitz, WA | Pass | Local |
| 2026-01-21 | WESTROCK LONGVIEW LLC — high-priority violation on file | LONGVIEW, Cowlitz, WA | Pass | State |
| 2026-01-20 | WESTROCK LONGVIEW LLC — high-priority violation on file | LONGVIEW, Cowlitz, WA | Pass | State |
| 2026-01-15 | CITY OF VANCOUVER / WESTSIDE WASTEWATER TREATMENT PLANT — high-priority violation on file | VANCOUVER, Clark, WA | Pass | Local |
| 2026-01-14 | PACKAGING CORPORATION OF AMERICA — high-priority violation on file | WALLULA, Walla Walla, WA | Pending | State |
Dates as filed by the agency that recorded the stack test. Figures from EPA’s ICIS-AIR download.
What this page shows
This page covers Clean Air Act facilities in the EPA air register with stack tests in WA for 2026. It lists 46 stack tests recorded in 2026.