Sewage Spill Contaminates Gallatin River Near Big Sky

Mar 4, 2016

State public health, environmental and wildlife officials are in Big Sky accessing the damage after the spill of millions of gallons of sewage water contaminated parts of the Gallatin River. The Montana Department of Environmental Quality’s Kristi Ponozzo says the treated waste does not pose a risk to human health.

West Fork of the South Fork of the Gallatin River on 3/3/16.
Credit Courtesy Explore Big Sky/Outlaw Partners

"The discharge is below the human health standard. What we are concerned about right now is sediment. As the wastewater is getting into streams it’s picking up a significant sediment load and sediment impacts aquatic life.”

The spill's impact on fish and other aquatic life is less clear. Ron Aasheim of Montana Fish, Wildlife and Parks says experts are on scene trying to figure it out.

"They’re looking at sediment load which is apparently the biggest concern. They’ll sample for hydrogen, phosphorous, ammonia – all the things that I don’t know a lot about. There are different implications to the fishery and the insect world than there are potentially to humans, so that’s the stuff we’re looking for.”

A broken pipe under a Big Sky holding pond released an estimated 35 million gallons of sewage water yesterday into the West Fork of the Gallatin River.

DEQ’s Kirsti Ponozzo says investigators don’t yet know why that outlet pipe broke. It flows into the Yellowstone Club Golf Course where irrigation of the turf grass is authorized in the summer. Yellowstone Club officials are reportedly cooperating with the state investigation.
State Environmental Health Department officials say the top priorities right now are damage assessment and establishing a water sampling and monitoring plan. Enforcement actions and potential fines will come later.