Polymet-Ltv
Key Takeaway
Polymet-Ltv is classified as significant hazard in Minnesota. It was completed in 1981 and is 45 years old. Its primary use is tailings. Significant hazard means failure could cause economic or environmental damage. Learn more.
Physical Details
| Dam Height | 65 ft (taller than 98.3% in MN) |
| Dam Length | 7,000 ft |
| Dam Type | Earth |
| Max Storage | 3.0K acre-ft |
| Normal Storage | 800 acre-ft |
| Surface Area | 200 acres |
| Drainage Area | 1 sq mi |
| Max Discharge | 50 cfs |
| Year Completed | 1981 (45 years old) |
| NID ID | MN00936 |
Safety Information
No probable loss of human life, but can cause economic loss, environmental damage, or disruption of lifeline facilities.
Hazard potential describes downstream consequences of failure, not the dam's current condition. What does this mean?
Ownership
Poly Met Mining, Inc.
Private
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Significant Hazard 35 ftFrequently Asked Questions
What is the hazard classification of Polymet-Ltv?
Polymet-Ltv is classified as Significant Hazard. No probable loss of human life, but can cause economic loss, environmental damage, or disruption of lifeline facilities. This classification refers to the potential downstream consequences of a failure, not the dam's current structural condition.
Who owns and operates Polymet-Ltv?
Polymet-Ltv is owned by Poly Met Mining, Inc. (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Polymet-Ltv built?
Polymet-Ltv was completed in 1981, making it 45 years old. Many U.S. dams were built between the 1930s and 1970s during a period of major infrastructure investment.
What is the primary purpose of Polymet-Ltv?
Polymet-Ltv serves the following purposes: Tailings. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.
How tall is Polymet-Ltv?
Polymet-Ltv has a dam height of 65 ft. Dam height is measured from the natural streambed at the downstream toe to the top of the dam, and may differ from the visible height.
When was Polymet-Ltv last inspected?
Polymet-Ltv was last inspected on October 5, 2022. Inspection dates indicate when a formal review occurred, not the results of that inspection.