// Risk Intelligence
| Risk Score | 7 / 10 High |
| Facility Type | ⚠ Superfund / Contamination Site |
| Operator / Branch | Atlantic Richfield / EPA |
| Host County | Missoula County MT |
| Nearest City | Washington DC |
| Primary Risk Radius | 5 miles |
| Secondary Risk Radius | 25 miles |
// Strategic Significance
Milltown Reservoir near Missoula accumulated toxic mine waste sediments from upstream Berkeley Pit and Anaconda operations for decades. The dam was removed in 2008 in one of the largest dam removal projects in US history specifically to address Superfund contamination. Arsenic from mine waste contaminated Milltown area wells serving as the Missoula area water supply.
// Civilian Impact Assessment
Missoula County residents downstream of the former reservoir continue to face residual arsenic and heavy metal contamination. The dam removal and dredging project significantly reduced but did not eliminate contamination.
// Evacuation & Shelter Guidance
Missoula County residents should follow Montana DEQ guidance on Clark Fork River use and groundwater monitoring near former reservoir.