EPA Air · by county
Air-emissions sources in Hampden County, Massachusetts
- 432Facilities
Every stationary source in Hampden County, Massachusetts that holds a Clean Air Act permit or is otherwise tracked by an air agency — planned, under construction, operating, seasonal or temporarily closed. Sources EPA records as permanently closed are not listed.
Every source’s record in Hampden County
Each of the 387 operating major, synthetic minor and minor sources in Hampden County, Massachusetts has a record page: every source in Hampden County, A to Z.
By emissions classification in Hampden County
A source’s classification is the size band its potential emissions put it in: a major source is large enough to need a Title V operating permit, a synthetic minor has accepted limits to stay below that line, and a minor source sits below it outright.
Inspections in Hampden County, by year
A compliance evaluation is the on-site or file review a state, local or federal air agency records against a permitted source.
- 2026 inspections 144
- 2025 inspections 165
- 2024 inspections 150
- 2023 inspections 109
- 2022 inspections 76
- 2021 inspections 64
- 2020 inspections 92
- 2019 inspections 162
- 2018 inspections 107
- 2017 inspections 129
Violations in Hampden County, by year
A high-priority violation is the most serious class of Clean Air Act non-compliance an agency records against a source; a federally reportable violation is the next step down in severity.
- 2026 violations 12
- 2025 violations 19
- 2024 violations 5
- 2023 violations 14
- 2022 violations 4
- 2019 violations 6
- 2018 violations 11
- 2017 violations 15
Stack tests in Hampden County, by year
A stack test measures what a source actually emits, at the stack, against the limit in its permit.
- 2026 stack tests 12
- 2025 stack tests 6
- 2024 stack tests 9
- 2023 stack tests 5
- 2021 stack tests 4
- 2019 stack tests 3
- 2018 stack tests 7
- 2017 stack tests 3
Inspections in Hampden County, year by year · Violations in Hampden County, year by year · Stack tests in Hampden County, year by year
Other counties in Massachusetts
Every county in the state with at least three sources on file.
- Barnstable County 95
- Berkshire County 104
- Bristol County 484
- Dukes County 7
- Essex County 376
- Franklin County 66
- Hampshire County 93
- Middlesex County 932
- Nantucket County 9
- Norfolk County 365
- Plymouth County 256
- Suffolk County 412
- Undetermined County 7
- Worcester County 696
Facilities
County as filed on the facility record. Figures from EPA’s ICIS-AIR download.
What this page shows
This page covers Clean Air Act facilities in the EPA air register for Hampden county, MA. It lists 432 facilities in Hampden county, of which 13 are major sources.