A new 20-year deal was passed Monday for the Kalispell Wastewater Treatment Plant to process Evergreen’s sewage.

The agreement replaces a previous measure that was in place since 1990. It sets the terms for the average of 500,000 daily gallons of waste that run through Evergreen pipes to the Kalispell facility.

It was passed by the Kalispell City Council on a unanimous vote.

“I think that it’s a great agreement, and we appreciate the Evergreen sewer as out largest customer,” council member Kari Gabriel said.

At a previous work session, Gabriel expressed concern that the new deal would remove a cap on the amount of daily material coming from Evergreen. Under the previous arrangement, no more than 682,000 gallons per day could be conveyed to Kalispell’s plant.

That cap was put into place before the treatment plant underwent a massive expansion starting in 2007, which increased its capacity.

But there was concern that over the life of the new 20-year agreement, there should be some safeguard to allow potential Kalispell developments to be served by the city plant.

Prior to Monday’s meeting, a cap of 782,000 gallons per day was put into the deal.

An Evergreen Water and Sewer District representative said the average has been steady at around 500,000 gallons.

Evergreen will pay Kalispell for the treatment. City officials estimate that this could be as much as $531,000 annually.

Reporter Matt Hudson may be reached at 758-4459 or by email at mhudson@dailyinterlake.com.