State issues Vail Resorts a notice of violation for 2021 fish kill
Snowmaking system incident ultimately put 2 million gallons of water into Mill, Gore Creek

Vail Resorts has received notice of violation and a cease and desist order in the wake of a spill last year from part of the Vail Mountain snowmaking system that ultimately resulted in a fish kill in Gore Creek.
The Colorado Department of Public Health and Environment issued the notice Monday, which outlines the incident, and orders ways to correct the problem.
The spill from a portion of the snowmaking system, a storage pond, began the afternoon of Sept. 17, and ended the morning of Sept. 20. The spill ultimately resulted in about 2 million gallons of water flowing into Mill and Gore creeks.
In a Sept. 21 investigation, Colorado Parks and Wildlife found water with a “bluish-white” tint where the system flowed into Mill Creek at a culvert near Vail’s Pirate Ship Park. The spill was visible on Gore Creek to a site just downstream of the Willow Bridge in Vail Village.
The investigation discovered 120 dead fish. The investigation also revealed dead algae and dead macroinvertebrates including worms and stoneflies.

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According to the report, water in the snowmaking pond had been treated with a “granular copper-based algaecide.” In addition, the potable water flowing into the pond is treated with chlorine.
The report refers to Vail Resorts as “Vail Corporation,” and notes that the spill qualifies as a “discharge of pollutants,” and that the company doesn’t have permits for any such discharge into Mill Creek.
The notice also includes several steps of “required corrective action” including:
- Develop and implement an operations and maintenance plan for management of its snowmaking system, and submit that plan to the state.
- That plan needs to include who will be notified whenever the company intends to drain the system.
- The plan needs to include details of a procedure for how the system will be drained to ensure all the valves and other parts of the system are in their proper positions.
- A sampling plan will be required, along with a plan for sampling water to ensure there are no harmful effects to Mill and Gore creeks.
The order states that Vail Corp. must answer the findings and submit an answer within 30 days.
Vail Resorts replied to the notice with the following statement:
“Vail Mountain provided a comprehensive response to (the Colorado Department of Public Health and Environment) regarding the circumstances of the accidental discharge last fall which included immediate measures to ensure that the potable water discharge would not happen again in the future, and we continue to cooperate with (the department) on this matter. We are still awaiting a final Colorado Parks and Wildlife report on the cause of the fish kill that occurred in Mill Creek at the time of the discharge.”
A valve on part of the Vail Mountain snowmaking system was opened the afternoon of Sept. 17, 2021.
Another valve was also open, allowing potable water to run into the system.
That water — approximately 2 million gallons — flowed into Mill Creek and then Gore Creek.
The discharge lasted until Sept. 20.
The result was a significant fish kill in Gore Creek.
