SODA SPRINGS, Calif. — What can nearly six years of planning and $19.5 million buy?

Well, if you’re the Donner Summit Public Utility District, it can buy an upgraded and expanded wastewater treatment plant — one of the most “technologically-advanced” plants in the region, according to district officials.

On Saturday, July 18, more than 100 people joined Placer County District 5 Supervisor Jennifer Montgomery and DSPUD officials to unveil the upgrades and expansion during a grand opening event.

“I am very thankful to our local community members who came out and participated in our planning meetings to understand the difficulties and the challenges that we were faced with in designing this project,” said Cathy Preis, DSPUD board president.

Over the years, DSPUD officials looked at many options, including how feasible it might be to pipe wastewater through the Tahoe Truckee Sanitation Agency, before making the call to invest in the $19.5 million project, said Tom Skjelstad, the district’s general manager.

Once the decision was made, Skjelstad said the district underwent a year-and-a-half-long process of public outreach and meetings to discuss how much customer rates would increase, as well as details of what the project was and how it was going to come together.

The upgrades and expansion were designed by Reno-based Stantec Engineers and constructed by Folsom-based Syblon Reid Contractors, and focused on lowering effluent ammonia and nitrate concentrations to meet California quality requirements for recycled water.

“The new treatment process uses tertiary treatment with membrane bioreactors to filter and treat the wastewater before discharging into the South Yuba River,” according to a district statement.

New structures include a headworks building, membrane and equipment building, an additional equalization storage tank, and sludge pump building.

Funding took its time, as did the review process — more than a year, Skjelstad recalled.

Project costs were distributed between Sierra Lakes County Water District and Donner Summit PUD. DSPUD secured a low-interest, 30-year loan through the State Revolving Fund to help reduce impact to ratepayers.

That loan funded about 56 percent of the wastewater upgrades and facility expansions, while Sierra Lakes, which shares the plant’s uses, supplied the remaining 44 percent.

As for the impact on ratepayers, “we had to service the debt on the loan,” Skjelstad said. “Somebody has to pay that down, so the rate payers have to do that.”

Though rates have increased, customers paying those rates had been doing so before the upgrades, as they had agreed to an additional annual charge of $593 on top of their monthly bill, Skjelstad said.

For residential customers who voted to tax themselves for the annual fee, their rate started at $117.58, or $2,003.96 per year, while those who voted against the tax will pay $167.02, or $2,597.24.

“Our customers pay a lot of money to flush their toilet up here,” Skjelstad said.