EVERETT — The city is preparing to start a $77 million upgrade of its wastewater treatment plant, which is nearing capacity.
Wastewater customers — the people footing the bill — should start preparing to see a hike in their rates next year.
The Everett City Council is expected to vote on a rate increase proposal this fall. The city hasn’t figured out how much that rate hike will be.
The plant on Smith Island is nearing capacity for the amount of waste that can be treated, said city project engineer John Nottingham.
The first part of the planned upgrade would allow the plant to treat 40 million gallons of wastewater, up from 33 million gallons. That project is expected to start in 2014 and take two years.
The second portion of the upgrade would allow the plant to process more solids by adding a digester, a large, heated tank that would break down the solid waste, Nottingham said. This part of the project is scheduled to begin in 2016.
The city also is weighing whether it pencils out to build a facility that would make power from the methane gas produced by the digester, said public works director Dave Davis.
What the plant upgrade project will not do is guarantee wastewater won’t again back up into people’s basements in the north end of town.
The older part of town in the north has a combined wastewater system that carries both sewer and storm water. The occasional deluge that drops inches of rain in a few minutes can overwhelm the system, sending a mix of rainwater and raw sewage burbling into basements. After such an event in June 2010, the city paid out hundreds of thousands of dollars to homeowners.
Last November, the city released millions of gallons of sewage into the Snohomish River and Port Gardner after a heavy rainstorm threatened to overwhelm a storage lagoon at the city’s wastewater plant.
The public works department is working on multiple projects right now to address these problems, including replacing pipes with larger ones, separating out some stormwater pipes from the sewer, and even implementing a trial program to see if residential rain gardens might help absorb runoff.
The improvements to other parts of the system should take some of the burden off the amount of wastewater the treatment plant has to process, Davis said.
Everett serves 136,000 customers, including portions of three nearby wastewater districts: Silver Lake, Alderwood and Mukilteo.
The city of Snohomish would like to build a giant pipeline to carry its waste to Everett’s plant for treatment, although its still negotiating an agreement with Everett.
The wastewater districts, which are wholesale customers, will pay their share for the planned upgrades, Davis said.
The $77 million upgrade is just one project ratepayers will be paying for in coming years. The treatment plant will be paid for using cash, low-cost state loans and bonds, said Matt Welborn, Everett’s utilities finance manager.
Everett’s three wholesale customers will pick up $18 million of the cost. If the city of Snohomish hooks in, that city will pay in the ballpark $3.5 million, he said.
Right now, Everett customers pay $154.80 every two months for water and sewer service. That amount is certain to increase beginning next year, but by how much hasn’t been determined, Welborn said.
The city is waiting on the results of a cost of service study. The City Council would ultimately approve any increase later this year.
Now, Everett’s rates are lower than many other cities, including Seattle.
Debra Smith: 425-339-3197; firstname.lastname@example.org.