It could be the single most expensive capital improvement the city has embarked on alone.
Yet it’s been in the pipeline for 38 months, popping up in the public eye on a regular basis and so far it’s under budget.
Those things may explain why it only took the City Council 15 minutes to direct city staff to execute a design-build agreement to start construction of a major wastewater treatment facility upgrade that will allow the city to comply with state law in the future.
Incoming wastewater requirements from regulators have in some ways forced the city’s hand in planning for changes to the city’s current wastewater facility. Something must be done to avoid expensive fines, and many months ago city officials began moving toward upgrading the wastewater treatment plant.
Originally slated to cost $95 million, city staff have worked to lower the cost of the project to $89.5 million, a 6 percent savings. Design-build projects often realize various savings because the same company that designs the project builds it.
“We set up the plan and we stuck to the plan,” Michael Lindquist, project manager, said.
The public helped the city choose a plan that will use expensive technology to meet wastewater treatment standards, but not to the degree of outputting recycled water clean enough to deliver to the drinking water treatment plant, as in some California communities.
Lindquist said besides the “ick factor” of using recycled water in drinking systems, the project called for in city plans was chosen in part for its relative frugality and for its ability to one day use recycled wastewater for irrigation.
The current wastewater treatment facility is 42 years old, Lindquist said. Parts of it need rehabilitation, and where treated effluent was delivered to holding ponds, a new commonly called tertiary treatment facility will take over and advance the treatment of the wastewater to, at one point, meet strict state standards for irrigation.
“Right now they put (recycled water) underground,” Lindquist said. “Our plant will be for reuse, but it won’t be potable, it could be for irrigation.”
Some tertiary treatment are so high-tech, they use both ultraviolet disinfection processes and reverse osmosis to produce pure water. Pure water sounds good, but it’s actually toxic to humans, Lindquist said, because it leaches minerals out of the body. Some communities in water-scarce places use recycled pure water in drinking water treatment plants to absorb minerals before being sent into potable water mains.
It’s unknown if pure recycled water could, years and years down the road, be a requirement for California communities. What is known is that the state will only become more strict in its wastewater requirements if a 40-year trend continues, Lindquist said.
“We do expect things to get more stringent,” he said. “(But) we participate in technical groups.”
Those groups allow communities to see changes coming years down the road and make preparations.
Lindquist said the eventual groundbreaking for the project could be planned soon.
— Reach Dave Ryan at [email protected] or call 530-747-8057. Follow him on Twitter at @davewritesnews