EPA Air · stack tests by county and year

Air-emissions stack tests in Williams County, North Dakota, 2025

14Stack 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 Williams County, North Dakota 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 Williams County facility page.

Williams County, North Dakota, 2025

Air-emissions stack tests in Williams County, other years

Air-emissions stack tests recorded in Williams County, North Dakota, 2025

Date	Facility	Kind	Agency
2025-11-11	BASIN ELECTRIC POWER COOPERATIVE - PIONEER GENERATION STATION - AQ	Pass	State
2025-10-23	HILAND PARTNERS HOLDINGS LLC - STONY CREEK COMPRESSOR STATION	Pass	State
2025-10-16	HILAND PARTNERS HOLDINGS LLC - EPPING COMPRESSOR STATION	N/A	State
2025-10-15	HESS TIOGA GAS PLANT LLC - TIOGA GAS PLANT - AQ	Pass	State
2025-10-14	BASIN ELECTRIC POWER COOPERATIVE - PIONEER GENERATION STATION - AQ	Pass	State
2025-09-09	HILAND PARTNERS HOLDINGS LLC - 4RUNNER COMPRESSOR STATION	Pass	State
2025-08-26	HILAND PARTNERS HOLDINGS LLC - BETHEL COMPRESSOR STATION	Pass	State
2025-07-22	HILAND PARTNERS HOLDINGS LLC - STONY CREEK COMPRESSOR STATION	Pass	State
2025-06-25	BASIN ELECTRIC POWER COOPERATIVE - PIONEER GENERATION STATION - AQ	Pass	State
2025-06-24	BASIN ELECTRIC POWER COOPERATIVE - PIONEER GENERATION STATION - AQ	Pass	State
2025-06-12	HILAND PARTNERS HOLDINGS LLC - 4RUNNER COMPRESSOR STATION	Pass	State
2025-06-03	HILAND PARTNERS HOLDINGS LLC - EPPING COMPRESSOR STATION	Pass	State
2025-04-16	HESS TIOGA GAS PLANT LLC - TIOGA GAS PLANT - AQ	Pass	State
2025-01-21	HESS TIOGA GAS PLANT LLC - TIOGA GAS PLANT - AQ	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 Williams county, ND, in 2025. It lists 14 stack tests recorded in 2025.