City of Sisters eyes sewer plant expansion

Sisters is in a race to keep up with growth and the city’s sewer system is no exception.

The municipal waste treatment facility at the south end of town is expected to reach capacity in about three years. The city hopes to expand the system’s capacity by then.

City Manager Eileen Stein said she hopes the city can get greater capacity without actually expanding the size of the treatment plant. That could be done if the plant can produce a higher quality of effluent.

“If we can go up to Level 2 or 3a or maybe even Level 4, perhaps we could apply a higher agronomic rate,” she said.

In other words, the city could spray more effluent on the forest land it currently irrigates. Better yet, the city might be able to irrigate pasture land such as the Lazy Z. That would eliminate the need for the city to acquire more forest land.

The city’s engineering firm, HGE, Inc., is currently working on a sewer master plan that will lay out the city’s options. Essentially, to raise the quality of effluent, it would need to be run through more filtration.

“It’s additional filtering that could be constructed right on the site of the current plant,” Stein said.

The plan will include cost information and the city will then have to determine how much of the improvement costs can be paid with Systems Development Charges and how much of the cost must be borne by ratepayers.

Stein said that it would take about three years to decide on an option and get it designed and built. She acknowledged that the time frame is tight.

“We’ve got to get moving, but we need to figure out what we’re going to build first,” she said.

HGE, Inc. is expected to present a preliminary sewer plan in about three months.