EPA Air · stack tests by county and year

Air-emissions stack tests in Yellowstone County, Montana, 2021

67Stack 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 Yellowstone County, Montana during 2021. 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 Yellowstone County facility page.

Yellowstone County, Montana, 2021

Air-emissions stack tests in Yellowstone County, other years

Air-emissions stack tests recorded in Yellowstone County, Montana, 2021

Date	Facility	Kind	Agency
2021-12-30	PAR MONTANA BILLINGS REFINERY	Pass	State
2021-12-22	WESTERN SUGAR COOPERATIVE — high-priority violation on file	Pass	State
2021-11-22	MONTANA SULPHUR & CHEMICAL	Pass	State
2021-11-22	MONTANA SULPHUR & CHEMICAL	Pass	State
2021-10-28	YELLOWSTONE POWER PLANT — high-priority violation on file	Pass	State
2021-10-14	CHS INC REFINERY LAUREL	Pass	State
2021-10-14	CHS INC REFINERY LAUREL	Pass	State
2021-08-19	CHS INC REFINERY LAUREL	Pass	State
2021-08-18	CHS INC REFINERY LAUREL	Pass	State
2021-08-16	CHS INC REFINERY LAUREL	Pass	State
2021-08-16	CHS INC REFINERY LAUREL	Pass	State
2021-08-16	CHS INC REFINERY LAUREL	Pass	State
2021-08-16	CHS INC REFINERY LAUREL	Pass	State
2021-08-16	CHS INC REFINERY LAUREL	Pass	State
2021-08-04	CHS INC REFINERY LAUREL	Pass	State
2021-08-04	CHS INC REFINERY LAUREL	Pass	State
2021-07-22	CHS INC REFINERY LAUREL	Pass	State
2021-07-22	CHS INC REFINERY LAUREL	Pass	State
2021-07-22	CHS INC REFINERY LAUREL	Pass	State
2021-07-22	CHS INC REFINERY LAUREL	Pass	State
2021-07-22	CHS INC REFINERY LAUREL	Pass	State
2021-07-22	CHS INC REFINERY LAUREL	Pass	State
2021-07-22	CHS INC REFINERY LAUREL	Pass	State
2021-07-22	CHS INC REFINERY LAUREL	Pass	State
2021-07-22	CHS INC REFINERY LAUREL	Pass	State
2021-07-22	CHS INC REFINERY LAUREL	Pass	State
2021-07-22	CHS INC REFINERY LAUREL	Pass	State
2021-07-22	CHS INC REFINERY LAUREL	Pass	State
2021-07-22	CHS INC REFINERY LAUREL	Pass	State
2021-07-09	PAR MONTANA BULK TERMINAL	Pass	State
2021-07-07	CHS INC REFINERY LAUREL	Pass	State
2021-07-07	CHS INC REFINERY LAUREL	Pass	State
2021-07-07	CHS INC REFINERY LAUREL	Pass	State
2021-07-07	CHS INC REFINERY LAUREL	Pass	State
2021-07-07	CHS INC REFINERY LAUREL	Pass	State
2021-07-07	CHS INC REFINERY LAUREL	Pass	State
2021-06-04	PAR MONTANA BILLINGS REFINERY	Pass	State
2021-06-04	PAR MONTANA BILLINGS REFINERY	Pass	State
2021-06-04	PAR MONTANA BILLINGS REFINERY	Pass	State
2021-05-25	BILLINGS REFINERY	Pass	State
2021-05-05	YELLOWSTONE POWER PLANT — high-priority violation on file	Pass	State
2021-05-03	YELLOWSTONE POWER PLANT — high-priority violation on file	Pass	State
2021-04-19	CHS INC REFINERY LAUREL	Pass	State
2021-04-19	CHS INC REFINERY LAUREL	Pass	State
2021-04-19	CHS INC REFINERY LAUREL	Pass	State
2021-04-19	CHS INC REFINERY LAUREL	Pass	State
2021-03-01	BILLINGS REFINERY	Pass	State
2021-02-02	BILLINGS REFINERY	Pass	State
2021-02-02	BILLINGS REFINERY	Pass	State
2021-01-18	BILLINGS REFINERY	Pass	State
2021-01-15	WESTERN SUGAR COOPERATIVE — high-priority violation on file	Pass	State
2021-01-15	MONTANA SULPHUR & CHEMICAL	Pass	State
2021-01-14	WESTERN SUGAR COOPERATIVE — high-priority violation on file	Pass	State
2021-01-14	WESTERN SUGAR COOPERATIVE — high-priority violation on file	Pass	State
2021-01-14	WESTERN SUGAR COOPERATIVE — high-priority violation on file	Pass	State
2021-01-12	BILLINGS REFINERY	Pass	State
2021-01-12	BILLINGS REFINERY	Pass	State
2021-01-12	BILLINGS REFINERY	Pass	State
2021-01-12	BILLINGS REFINERY	Pass	State
2021-01-12	BILLINGS REFINERY	Pass	State
2021-01-12	BILLINGS REFINERY	Pass	State
2021-01-12	BILLINGS REFINERY	Pass	State
2021-01-12	PAR MONTANA BILLINGS REFINERY	Pass	State
2021-01-06	BILLINGS REFINERY	Pass	State
2021-01-05	BILLINGS REFINERY	Pass	State
2021-01-05	BILLINGS REFINERY	Pass	State
2021-01-05	BILLINGS REFINERY	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 Yellowstone county, MT, in 2021. Stack tests recorded in 2021: 67.