This article was published on: 04/22/16 12:00 AM
New wetlands will filter wastewater, expand treatment system
By Kailey Fisicaro
PRINEVILLE — When the city of Prineville was faced with expanding its wastewater capacity a decade ago, estimates showed a new mechanical treatment plant would cost $62 million.
Over several years, city staff researched a more environmentally friendly option that would save millions of dollars: man-made wetlands that filter the water and return some of it to the Crooked River. Construction of the wetlands adjacent to the river in northwest Prineville began in January, and today a ceremonial groundbreaking takes place.
The person who drove the project, Eric Klann, city engineer and public works director, was hired in fall 2007, a couple years after talks of the pricey mechanical plant had begun. He said the first big question city councilors had for him was whether he could figure out a less expensive, but still effective, expansion of the wastewater system.
Prineville already used a somewhat untraditional system, a series of lagoons, to filter wastewater that’s later used to irrigate. When Klann talked with city staff members, they said the lagoons worked well — they just couldn’t support a growing city. Lagoons are generally used for smaller communities.
That’s when Klann, with other staffers, began researching how to expand on the lagoons by building wetlands that further filter wastewater. Council approved the project in 2010.
In comparison with a $62 million treatment plant, the Crooked River Wetlands Complex will cost $7.9 million, and about half of that will be covered by several grants from a range of agencies and organizations, from Oregon State Parks and the Oregon Watershed Enhancement Board to The Pelton Fund, founded by Portland General Electric Co. and the Confederated Tribes of Warm Springs to protect salmon and steelhead.
Beyond acting as wastewater treatment, the wetlands project will:
• Offer habitat, including for creatures such as threatened steelhead.
• Improve the riverbanks, allowing the river to return to a more natural, crooked flow, and add cool, clean water to the Crooked River year-round. The cool water is also beneficial for steelhead.
• Create recreational opportunities with 5.4 miles of trails (3.25 miles paved) and a 5-kilometer loop around the wetlands. Parking, restrooms and facilities for events will also be available.
• Have educational use. Local schools are creating informational kiosks and learning about the project. A few classes have already taken field trips to the site.
“It’s really, really a natural process; it’s very inexpensive to operate, but basically all the water around town comes into the lowest point and that’s our headworks,” Klann said of the existing lagoons. “At that point, we screen all the nonorganics out, so plastics — people flush some pretty crazy stuff down the toilet — hypodermic needles … We’ve pulled a basketball out of there one time, not sure how that made it in there.”
After traveling to the lagoons, wastewater reaches a series of bays, at different levels, which have bacteria and aerators that help create oxygen in the water .
“The bacteria use the oxygen and eat all the organics in the system, and that purifies the water as it goes through,” Klann said. “It takes a long time to treat it. But it’s very inexpensive, and the natural environment just does it.”
When the new wetlands are constructed , the water will continue its journey through them, which will further filter the waste with plants such as cattails and reeds.
“We also (will) have a couple of processes where we go from a shallow wetland to a deep wetland to a shallow wetland, and that helps get some of the ammonia and things like that,” Klann said.
Klann said the wetlands are also designed to be an inhospitable environment for mosquitoes. There are two wetland spots the city created as tests a few years back, but for the most part right now, the 120 acres that will be turned into wetlands still look like leveled fields of dirt. Workers are using large equipment to build dikes that will separate the series of wetland cells.
“We’re expecting the major construction to be done in December,” said Mike Kasberger, assistant city engineer and one of the leads on the project. “That’s not to say we’ll be fully functional at that time, because we’re going to take some time to make sure the plant establishment goes successfully before we turn the river into it.”
Klann laughed explaining the number of permits the project has taken over the years. A stack of them on his desk — he measured — is 17 inches tall. He’s been happy to have the support of the City Council, where he said the members have had a lot of foresight.
“We’ll probably open it up to the public in the spring, but we’ll be irrigating. … You know, it takes a couple years to get all of your willows and everything to establish,” Klann said.