Madison County, MT
The federal environmental record for Madison County (population 9,521): what is on file, where it is, and what remains open. Sources and retrieval dates are on the methodology page.
0
Superfund NPL sites
2
federal cleanup sites
1
PFAS-detecting water systems
0
TRI facilities
14
open tank releases
Drinking water: PFAS testing
Public water systems serving Madison with at least one PFAS detection under UCMR5. The federal limit for PFOA and PFOS is 4 ng/L; EPA proposed in May 2026 to rescind the limits for the other compounds, which are shown for information.
| System | Highest results | Reading |
|---|---|---|
| BIG SKY COUNTY WATER AND SEWER DIST 363 MT0002385 | PFBS: 3.1 ng/L | detected |
On a system with detections? Testing and treatment options
Underground fuel tanks
EPA's UST Finder records 78 tank facilities in Madison: 35 tanks in service and 153 closed. 73 fuel releases are on record, of which 14 remain open. Open releases are cleanups that have not reached "no further action".
Radon
EPA maps Madison as Zone 1, the highest predicted indoor radon levels (over 4 pCi/L average). Radon and air quality are covered in depth on lung.com.
The record for one specific address
County figures blur what matters: distance. The Address Environmental Report runs these same federal datasets against one address and reports every site, tank, polluter and water result around it, with distances, in about a minute.
Get the report - $39All federal cleanup sites on file
The wider Superfund enterprise inventory (SEMS) for Madison, including sites assessed but never listed. Presence here records that EPA had reason to look, not a finding of danger.
- NORRIS LABSNORRIS
- USDA FS ENNIS LYONS STATIONENNIS