EPA Air · stack tests by county and year

Air-emissions stack tests in Marathon County, Wisconsin, 2025

22Stack 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 Marathon County, Wisconsin 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 Marathon County facility page.

Marathon County, Wisconsin, 2025

Air-emissions stack tests in Marathon County, other years

Air-emissions stack tests recorded in Marathon County, Wisconsin, 2025

Date	Facility	Kind	Agency
2025-10-20	WI PUBLIC SERVICE WESTON POWER PLANT	Pass	State
2025-10-20	WI PUBLIC SERVICE WESTON POWER PLANT	Pass	State
2025-09-30	WISCONSIN ELECTRIC POWER COMPANY (DBA WE ENERGIES) - ROTHSCHILD BIOMASS COGENERA — high-priority violation on file	Pass	State
2025-09-15	MULLINS CHEESE INC — high-priority violation on file	Pass	State
2025-08-19	BUCKHORN RNG, LLC	Pass	State
2025-08-12	WISCONSIN ELECTRIC POWER COMPANY (DBA WE ENERGIES) - ROTHSCHILD BIOMASS COGENERA — high-priority violation on file	Pass	State
2025-07-22	MARTH WOOD SHAVINGS SUPPLY INC — high-priority violation on file	Pass	State
2025-07-14	WI PUBLIC SERVICE WESTON POWER PLANT	Pass	State
2025-07-14	WI PUBLIC SERVICE WESTON POWER PLANT	Pass	State
2025-07-14	WI PUBLIC SERVICE WESTON POWER PLANT	Pass	State
2025-07-14	WI PUBLIC SERVICE WESTON POWER PLANT	Pass	State
2025-07-10	MULLINS CHEESE INC — high-priority violation on file	Pass	State
2025-07-02	CRYSTAL FINISHING SYSTEMS INC	Pass	State
2025-06-02	AHLSTROM MOSINEE, LLC — high-priority violation on file	Pass	State
2025-05-12	WI PUBLIC SERVICE WESTON POWER PLANT	Pass	State
2025-05-12	WI PUBLIC SERVICE WESTON POWER PLANT	Pass	State
2025-05-12	WI PUBLIC SERVICE WESTON POWER PLANT	Pass	State
2025-05-12	WI PUBLIC SERVICE WESTON POWER PLANT	Pass	State
2025-05-12	WI PUBLIC SERVICE WESTON POWER PLANT	Pass	State
2025-05-08	AHLSTROM MOSINEE, LLC — high-priority violation on file	Pass	State
2025-03-25	DOMTAR PAPER CO LLC	Pass	State
2025-03-10	AHLSTROM MOSINEE, LLC — high-priority violation on file	Pass	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 Marathon county, WI, for 2025. It lists 22 stack tests recorded in 2025.