Flagstaff's Wildcat Hill sewage treatment plant has never met what city officials promised voters as part of an original $23.1 million upgrade that ballooned to $37 million and counting.
Rarely has the plant, one of two in the city, produced the cleanest grade of reclaimed water possible in Arizona, though it was certified as doing so in January 2010, city staff confirmed Friday.
"It's never been A+," said Brad Hill, utilities director for the city of Flagstaff. "What we're looking to do is what we promised to the citizens in the community, and that's to make an A+ plant."
The bottom line: While it is taking in sewage and processing it, Wildcat Hill is sending most of its reclaimed wastewater discharge into the Rio de Flag through Picture Canyon, with the exception of some golf-course customers.
That keeps the plant's treated effluent out of the city's reclaimed wastewater pipelines, which are typically said to carry only an A+ product.
Although city officials have known about this problem since at least July 2010, they are just now raising the issue ahead of a Flagstaff City Council meeting on Tuesday to discuss violations of the plant's state permit.
The test for what grade the water meets involves measuring averages over a handful of months, ignoring precise points in time.
It's not that Wildcat has never been A+. But rarely has the city met that standard, due to an excess of what might politely be called "solids" in the system.
That's 1,100 tons of waste that flows through the A+ Rio de Flag sewage treatment plant and downstream to Wildcat Hill, and more that is trucked in by sewage haulers from subdivisions around Coconino County -- or 400 tons more sewage than Wildcat was ever meant to handle.
Further, the city has also drawn attention from the Arizona Department of Environmental Quality and the U.S. Environmental Protection Agency for a one-time finding of high selenium and cyanide readings.
That's believed to be more of an isolated incident, but the excess of nitrogen that is violating the A+ standard is not. Although the city says the excess nitrogen poses no risk to human health, the discharge eventually makes its way to the Coconino Aquifer, where city wells tap it for drinking water. Excessive nitrogen must be treated with chlorine, which the federal EPA notes can pose additional risks to human health.
Now, Flagstaff must enter new agreements with the state's environmental regulators, and seek out new solutions for removing waste from Wildcat Hill that may require what the city says are "multimillion-dollar upgrades."
"Wildcat won't be pumping into the reclaimed distribution system until it produces A+ water," Hill said.
Hill and Deputy City Manager Josh Copley said there was no water from this plant headed to Arizona Snowbowl this year for making snow, as the tank feeding into Snowbowl's distribution point was drained in October and refilled with A+ water from the Rio de Flag plant.
"The city is not, nor has it ever, distributed reclaimed water from Wildcat to Snowbowl," the city said in a press release.
Solid wastes from the sewage treatment plant are now removed and pumped onto the ground beside Wildcat.
The city has contacted multiple engineering firms to attempt to figure out how to make A+ grade wastewater at Wildcat, including making a July 2010 call to its original designer, Black and Veatch.
The next likely plan for separating out these wastes would involve putting large volumes of sludge into giant bean-bag-like vessels, or "geotextile tubes," where the weight of the waste would settle, and water could be drained away from the top.
Such vessels would have to be kept warm enough not to freeze during cold weather.
The drier waste from these containers would still be planted in the ground adjoining Wildcat.
Cyndy Cole can be reached at firstname.lastname@example.org or at 913-8607. Joe Ferguson can be reached at email@example.com or at 556-2253.