EAGLE — In September, contamination of Mill Creek and Gore Creek, which killed 120 fish in Vail, was the result of errors by Vail Resorts and Ski & Snowboard Club Vail, which likely occurred in the spring, according to information supplied to the Colorado Department of Public Health and Environment by Vail Resorts.

The state health department is still investigating the incident to determine what violation of the state’s Water Quality Control Act might be associated with the incident as well as the responsible parties.

On Sept. 21, Colorado Parks and Wildlife began an investigation in coordination with the state health department to trace the source of the fish kill. Days earlier, about 2 million gallons of water had been inadvertently discharged into Mill Creek as a result of an error that occurred during the snowmaking process.

That water consisted of about 1.5 million to 2 million gallons of potable water from an Eagle River Water and Sanitation District tank used by Ski & Snowboard Club Vail for snowmaking in addition to about 200,000 gallons of water from Vail Mountain’s snowmaking storage pond, according to statements provided to the state from Jonathan Kimchi, Vail Resorts director of environmental compliance.

Kimchi said the pond water had been treated with one 30-pound bag of Cutrine-Plus Granular Algaecide, which contains ethanolamine and copper carbonate.

“Vail applied 62% less than the allowable dosage rate on the label,“ Kimchi said in his statement. ”Since June, the pond volume increased from 13 acre-feet to 17 acre-feet, which would have further diluted the concentration of algaecide. Based on these facts, the algaecide likely had no adverse impact on Mill Creek.“

Valves left open

Eagle River Water and Sanitation District has long supplied potable water to Ski & Snowboard Club Vail for early season snowmaking at Golden Peak, part of a 2007 improvements package that created an early season training venue that attracts national teams to Vail during the month of November for race training.

According to information supplied to the state by Vail Resorts, the incident traces its origins to two snowmaking employees working at the Golden Peak Pumphouse. The two have since voluntarily left the company.

These workers “opened the valves during spring 2021 to irrigate the Race Course as requested by (Ski & Snowboard Club Vail),” according to Kimchi’s report. The valves were then “left open inadvertently by these Golden Peak snowmaking employees in the spring, and the snowmaking team was not aware that this had happened when it conducted its activities on Sept. 16 and 17.”

“As was discovered later … water from the (Eagle River Water and Sanitation District) Tank No. 2 mistakenly and unbeknownst to the snowmaking team started moving through the Vail Mountain snowmaking system,“ according to Kimchi’s report.

In the report, Kimchi said Vail Mountain and the Eagle River Water and Sanitation District are taking steps to prevent something like this from occurring again in the future.

“Vail Mountain and (the Eagle River Water and Sanitation District are) developing a joint operating procedure that will require contacting (the sanitation district) prior to snowmaking activities to request (that it) unlock and open the valves inside the pump house, and close and lock the valves when the activity is complete,” Kimchi said in the report. “In addition, Vail Mountain will conduct additional training of its employees regarding this new procedure with (the sanitation district).”

This story is from VailDaily.com.