As a city, Bonney Lake has been defined by growth. Incorporated in 1949, it has grown roughly three times the physical size of neighboring Sumner in almost half the time, though the residential populations are comparable, according to the most recent federal census.

But with growth comes the need for resources to sustain it. To that end, Bonney Lake planners are searching for alternative sewer routes to handle projected growth.

Bonney Lake currently relies on Sumner for its sewage treatment. All waste from Bonney Lake’s sewer system flows through a single pipeline down Elhi Hill to the sewage treatment plant on 63rd Street East.

“That won’t continue to work as we grow,” Deputy Mayor Dan Swatman said. “Our sewer area is much larger than can be handled by one pipeline.”

The need for increased sewage processing isn’t immediate. Bonney Lake probably won’t need the increased capacity for another decade or two, Swatman said. But the city is planning ahead for anticipated growth in its Comprehensive Urban Growth Areas and on 496 acres of Plateau land in the city’s jurisdiction.

The city is considering several options for alternate sewer routes, including Auburn, Buckley and the Lacey/Olympia/Tumwater Consortium. Auburn, as the closest community to Bonney Lake next to Sumner, has the most feasibility in creating a pipeline. The city of Buckley’s water treatment plant was designed to hook up to other cities’ sewer lines and would require a pipeline along state Route 410, which could spur growth on that undeveloped stretch, Buckley Mayor Pat Johnson said. The Consortium has a technological advantage. Its treatment plant utilizes a membrane bioreactor that extends its handling capacity for waste fluids.

“We’re keeping options on the radar,” Swatman said. “For a city that has significant growth, we just need to plan for more sewer capacity.”