EPA Air · stack tests by state, industry and year

Utilities (NAICS 2211): stack tests in Montana, 2023

61Stack tests

A stack test measures what a source actually emits, at the stack, against the limit in its permit. Each row is one stack test recorded during 2023 at a Montana source whose primary industry code is NAICS 2211. A facility filing more than one industry code is counted under the first one on its record.

Utilities (NAICS 2211) in Montana, other years

Other industries in Montana, 2023

Air-emissions stack tests recorded in Montana, 2023

Date	Facility	Where	Kind	Agency
2023-12-26	ROCKY MOUNTAIN POWER	HARDIN, Big Horn, MT	Pass	State
2023-12-26	COLSTRIP STEAM ELECTRIC STATION	COLSTRIP, Rosebud, MT	Pass	State
2023-12-26	COLSTRIP STEAM ELECTRIC STATION	COLSTRIP, Rosebud, MT	Pass	State
2023-12-21	COLSTRIP STEAM ELECTRIC STATION	COLSTRIP, Rosebud, MT	Pass	State
2023-12-15	COLSTRIP ENERGY LTD PARTNERSHIP	COLSTRIP, Rosebud, MT	Pass	State
2023-12-15	COLSTRIP ENERGY LTD PARTNERSHIP	COLSTRIP, Rosebud, MT	Pass	State
2023-12-15	COLSTRIP ENERGY LTD PARTNERSHIP	COLSTRIP, Rosebud, MT	Pass	State
2023-12-15	COLSTRIP ENERGY LTD PARTNERSHIP	COLSTRIP, Rosebud, MT	Pass	State
2023-11-28	ROCKY MOUNTAIN POWER	HARDIN, Big Horn, MT	Pass	State
2023-11-13	MDU - GLENDIVE	GLENDIVE, Dawson, MT	Pass	State
2023-11-13	MDU - GLENDIVE	GLENDIVE, Dawson, MT	Pass	State
2023-10-31	COLSTRIP STEAM ELECTRIC STATION	COLSTRIP, Rosebud, MT	Pass	State
2023-10-31	COLSTRIP STEAM ELECTRIC STATION	COLSTRIP, Rosebud, MT	Pass	State
2023-10-12	ROCKY MOUNTAIN POWER	HARDIN, Big Horn, MT	Pass	State
2023-10-09	ROCKY MOUNTAIN POWER	HARDIN, Big Horn, MT	Pass	State
2023-10-09	ROCKY MOUNTAIN POWER	HARDIN, Big Horn, MT	Pass	State
2023-10-06	ROCKY MOUNTAIN POWER	HARDIN, Big Horn, MT	Pass	State
2023-10-05	YELLOWSTONE POWER PLANT — high-priority violation on file	BILLINGS, Yellowstone, MT	Pass	State
2023-08-21	ROCKY MOUNTAIN POWER	HARDIN, Big Horn, MT	Pass	State
2023-07-21	YELLOWSTONE POWER PLANT — high-priority violation on file	BILLINGS, Yellowstone, MT	Pass	State
2023-04-24	ROCKY MOUNTAIN POWER	HARDIN, Big Horn, MT	Pass	State
2023-04-21	COLSTRIP STEAM ELECTRIC STATION	COLSTRIP, Rosebud, MT	Pass	State
2023-04-21	COLSTRIP STEAM ELECTRIC STATION	COLSTRIP, Rosebud, MT	Pass	State
2023-04-03	BASIN ELECTRIC POWER COOPERATIVE	BAINVILLE, Roosevelt, MT	Pass	State
2023-04-03	BASIN ELECTRIC POWER COOPERATIVE	BAINVILLE, Roosevelt, MT	Pass	State
2023-03-28	COLSTRIP STEAM ELECTRIC STATION	COLSTRIP, Rosebud, MT	Pass	State
2023-03-28	COLSTRIP STEAM ELECTRIC STATION	COLSTRIP, Rosebud, MT	Pass	State
2023-03-28	COLSTRIP STEAM ELECTRIC STATION	COLSTRIP, Rosebud, MT	Pass	State
2023-03-28	COLSTRIP STEAM ELECTRIC STATION	COLSTRIP, Rosebud, MT	Pass	State
2023-03-28	COLSTRIP STEAM ELECTRIC STATION	COLSTRIP, Rosebud, MT	Pass	State
2023-03-21	YELLOWSTONE POWER PLANT — high-priority violation on file	BILLINGS, Yellowstone, MT	Pass	State
2023-03-17	COLSTRIP STEAM ELECTRIC STATION	COLSTRIP, Rosebud, MT	Pass	State
2023-03-17	COLSTRIP STEAM ELECTRIC STATION	COLSTRIP, Rosebud, MT	Pass	State
2023-03-14	BASIN CREEK POWER SERVICES	BUTTE, Silver Bow, MT	Pass	State
2023-03-14	BASIN CREEK POWER SERVICES	BUTTE, Silver Bow, MT	Pass	State
2023-03-14	BASIN CREEK POWER SERVICES	BUTTE, Silver Bow, MT	Pass	State
2023-03-14	BASIN CREEK POWER SERVICES	BUTTE, Silver Bow, MT	Pass	State
2023-03-14	BASIN CREEK POWER SERVICES	BUTTE, Silver Bow, MT	Pass	State
2023-03-14	BASIN CREEK POWER SERVICES	BUTTE, Silver Bow, MT	Pass	State
2023-03-14	BASIN CREEK POWER SERVICES	BUTTE, Silver Bow, MT	Pass	State
2023-03-14	BASIN CREEK POWER SERVICES	BUTTE, Silver Bow, MT	Pass	State
2023-03-14	BASIN CREEK POWER SERVICES	BUTTE, Silver Bow, MT	Pass	State
2023-03-10	YELLOWSTONE POWER PLANT — high-priority violation on file	BILLINGS, Yellowstone, MT	Pass	State
2023-02-21	ROCKY MOUNTAIN POWER	HARDIN, Big Horn, MT	Fail	State
2023-01-30	ROCKY MOUNTAIN POWER	HARDIN, Big Horn, MT	Pass	State
2023-01-23	COLSTRIP ENERGY LTD PARTNERSHIP	COLSTRIP, Rosebud, MT	Pass	State
2023-01-23	YELLOWSTONE POWER PLANT — high-priority violation on file	BILLINGS, Yellowstone, MT	Pass	State
2023-01-19	ROCKY MOUNTAIN POWER	HARDIN, Big Horn, MT	Pass	State
2023-01-19	ROCKY MOUNTAIN POWER	HARDIN, Big Horn, MT	Pass	State
2023-01-16	FLATHEAD ELECTRIC LFGE FACILITY	KALISPELL, Flathead, MT	Pass	State
2023-01-12	DAVE GATES GENERATING STATION AT MILL CREEK	ANACONDA, Deer Lodge, MT	Pass	State
2023-01-12	DAVE GATES GENERATING STATION AT MILL CREEK	ANACONDA, Deer Lodge, MT	Pass	State
2023-01-12	DAVE GATES GENERATING STATION AT MILL CREEK	ANACONDA, Deer Lodge, MT	Pass	State
2023-01-12	DAVE GATES GENERATING STATION AT MILL CREEK	ANACONDA, Deer Lodge, MT	Pass	State
2023-01-12	DAVE GATES GENERATING STATION AT MILL CREEK	ANACONDA, Deer Lodge, MT	Pass	State
2023-01-12	DAVE GATES GENERATING STATION AT MILL CREEK	ANACONDA, Deer Lodge, MT	Pass	State
2023-01-09	ROCKY MOUNTAIN POWER	HARDIN, Big Horn, MT	Pass	State
2023-01-09	ROCKY MOUNTAIN POWER	HARDIN, Big Horn, MT	Pass	State
2023-01-09	FLATHEAD ELECTRIC LFGE FACILITY	KALISPELL, Flathead, MT	Pass	State
2023-01-06	COLSTRIP STEAM ELECTRIC STATION	COLSTRIP, Rosebud, MT	Pass	State
2023-01-06	COLSTRIP STEAM ELECTRIC STATION	COLSTRIP, Rosebud, MT	Pass	State

Primary NAICS code as filed on the facility record; dates as filed by the agency that recorded the stack test. Figures from EPA’s ICIS-AIR download.