The pond, which is used to irrigate the golf course at the Big Sky, Mont., property, poured 29 million gallons of treated wastewater into the Gallatin River over four days through a leak that officials believe was caused by an ice formation. Though the water is not believed to pose a health risk to humans, the club is working on a reclamation plan and will likely be penalized for the spill.

A pond at the Yellowstone Club in Big Sky, Mont., that poured about 29 million gallons of treated wastewater into the Gallatin River stopped leaking on March 7 after muddying the river and some of its tributaries over the previous four days, the Bozeman, Mont.-based Daily Chronicle reported.

Engineers are still investigating exactly what caused the spill, but the Yellowstone Club and the Montana Department of Environmental Quality (DEQ) said Monday that the pond emptied around 4 a.m. Monday. DEQ public policy director Kristi Ponozzo said the pond emptying was a “big step,” and that now they could start talking about how to repair and clean up the spill, the Chronicle reported.

Matthew Kidd, a spokesman for the Yellowstone Club, said in an email that they are working on a reclamation plan, but added that the work might not take place immediately, the Chronicle reported.

“Some of the work may have to wait until the slopes are safe and dry enough to work on. As we work to repair the environment, one of our main concerns is not further damaging the site with our equipment,” Kidd said, adding that they don’t know how much the work will cost. The Big Sky Water and Sewer District is taking the club’s sewer water while the pond is being worked on, which its manager, Ron Edwards, said it has plenty of space for.

C&RB featured Yellowstone Club’s recreation and fitness programs in its October 2010 issue.

Ponozzo said the DEQ will have some sort of penalty for the Yellowstone Club for the spill, but she didn’t know what it would be. Figuring that out could take months, she said, and isn’t the agency’s focus right now, the Chronicle reported.

“Right now, we’re focused on testing for water quality, making sure everything is OK,” she said.

The spill was first spotted by a Yellowstone Club employee Thursday morning. A pipe next to the pond had broken and was letting water flow out and into Second Yellow Mule Creek. Officials believe an ice formation caused the break, but haven’t confirmed yet whether that was the case. The pond held about 35 million gallons of water, which had been treated and isn’t believed to pose a health risk to humans. The water is used to irrigate the Yellowstone Club’s golf course, the Chronicle reported.

It picked up dirt as it flowed into the creek and through the system of tributaries, turning clear streams into chocolate milk. Eventually the flow reached the main Gallatin, which became clouded throughout the canyon. No attempts to stop the leak were made. The club said there was no safe way to do so. About 6 million gallons were diverted to a different pond, and the rest drained out, the Chronicle reported.

On Monday, turbidity levels were lower in streams near the discharge, meaning the water had become clearer. Meanwhile, that measure increased in parts of the Gallatin downstream, meaning it became more clouded. DEQ officials are still testing the water for chemicals and bacteria. On Monday, they tested for E.coli, and results are expected this week. Results from other tests are expected back within the next few weeks, the Chronicle reported.

FWP biologist Dave Moser said he would be visiting the area later this week to examine the effects the spill might have had on fish. He told the Chronicle last week that sediment picked up by the large volume of water was the main concern since it could make it harder for fish to breathe. Some brown trout spawning redds in the area could be impacted, the Chronicle reported.

While there is believed to be no risk to human health, the Yellowstone Club is urging people with wells downstream to test their wells. The Gallatin River Taskforce is giving out free sampling kits at the Big Sky post office on Tuesday between 11 a.m. and 2 p.m., and the Yellowstone Club has offered to pay all well sampling lab fees for the next year, the Chronicle reported.