EPA Air · stack tests by county and year

Air-emissions stack tests in Lewis County, Washington, 2025

17Stack 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 Lewis County, Washington 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 Lewis County facility page.

Lewis County, Washington, 2025

Air-emissions stack tests in Lewis County, other years

Air-emissions stack tests recorded in Lewis County, Washington, 2025

Date	Facility	Kind	Agency
2025-12-10	HARDEL MUTUAL PLYWOOD CORPORATION — high-priority violation on file	Pass	Local
2025-12-09	HARDEL MUTUAL PLYWOOD CORPORATION — high-priority violation on file	Pass	Local
2025-11-04	TRANSALTA CENTRALIA GENERATION, LLC — high-priority violation on file	Pass	Local
2025-10-22	PUGET SOUND ENERGY (WA NATURAL GAS)	Pass	Local
2025-10-21	PUGET SOUND ENERGY (WA NATURAL GAS)	Pass	Local
2025-10-21	PUGET SOUND ENERGY (WA NATURAL GAS)	Pass	Local
2025-10-20	PUGET SOUND ENERGY (WA NATURAL GAS)	Pass	Local
2025-09-16	TRANSALTA CENTRALIA GENERATION, LLC — high-priority violation on file	Pass	Local
2025-07-30	TRANSALTA CENTRALIA GENERATION, LLC — high-priority violation on file	Pass	Local
2025-05-08	ROCKY MOUNTAIN POWER - CHEHALIS POWER GENERATING, L.P.	Pass	Local
2025-05-07	ROCKY MOUNTAIN POWER - CHEHALIS POWER GENERATING, L.P.	Pass	Local
2025-05-06	ROCKY MOUNTAIN POWER - CHEHALIS POWER GENERATING, L.P.	Pass	Local
2025-05-06	PUGET SOUND ENERGY (WA NATURAL GAS)	Pass	Local
2025-03-25	TRANSALTA CENTRALIA GENERATION, LLC — high-priority violation on file	Pass	Local
2025-02-18	HAMPTON LUMBER MILLS - MORTON	Pass	Local
2025-01-30	HARDEL MUTUAL PLYWOOD CORPORATION — high-priority violation on file	Pass	Local
2025-01-15	TRANSALTA CENTRALIA GENERATION, LLC — high-priority violation on file	Pass	Local

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 Lewis county, WA, for 2025. It lists 17 stack tests recorded in 2025.