After several years of construction and costs of over $12 million, Cottonwood’s Riverfront Water Reclamation Facility is not currently able to reclaim wastewater in a way that allows it to pump it back into the system for reuse.
Starting in February, the city utilities department encountered problems with the disinfection stage of water treatment and has since been working to fix these problems. Meanwhile, the water that flows through the plant is pumped back to the Mingus Avenue plant, where it is fully treated before the water is injected back into the ground, as if there were no Riverfront plant.
Cottonwood city officials have repeatedly stressed that this problem has not in any way affected community safety, nor led to any untreated water being injected back into the groundwater.
In the water treatment process at the plant, bacteria is introduced to the effluent to break down solid waste. The water is then filtered and, as one of the final steps, it is supposed to be bombarded with strong ultraviolet light in a full tank to kill the bacteria. According to city of Cottonwood officials, due to a still not fully understood mechanical problem, that UV tank, which is supposed to be kept full of water at all times no matter how much water is coming into the system, is nearly drying out in the middle of the night when water flow into the system is at its lowest.
Compounding this problem, the UV bulbs, which are supposed to automatically reduce in intensity when the system’s flow is low, are not doing so due to a software problem. If the bulbs are left to run at full power in a nearly empty tank, they risk burning out. The utility staff has taken to manually shutting down the system at certain hours rather than risk damage.
“That causes us problem because it needs to work properly 24 hours a day, so that we don’t put water that is not compliant out into the reservoir,” Cottonwood Utilities Manager Roger Biggs said. “So rather than do that, we’ve got it offline until we can work this problem out — and we are working it out. There’s various contractors and programmers and electricians involved in it.”
Cottonwood City Manager Ron Corbin — who encountered this problem almost immediately after taking over the position in January — assigned Cottonwood Natural Resources Manager Tom Whitmer as a director to coordinate various city employees and departments in order to fix this problem. Whitmer sees this as an issue that needs to be solved, but not an insurmountable one.
“I’ve been involved in lots of big projects in my past and you always, with any new large plant, be it a power plant or be it a wastewater treatment plant — you’re trying to automate as much as you can,” Whitmer said. “You’ve got all these details that need to be maintained and you do the best that you possibly can to make sure that they are accurately installed, accurately programmed and soon. But at the end of the day, there are always little quirks that you’re going to run across that create problems, and this is just one of those issues that we’ve identified as being problematic for us and one that we need to fix.
“How it occurred, I can’t really tell you where the slip was. Any plant you build is never going to be at 100% when you turn the switch, where everything just works perfectly. Never happens that way. I don’t care how good you are at your quality control — it never happens.”
In the current situation, the water treatment plant has been cleared to operate by the Arizona Department of Environmental Quality, but ADEQ has not yet approved the water to be injected back into the groundwater.
The plant had been set up to be able to pump water back to the Mingus plant, which city officials expected until ADEQ licensing was finished. In their view, this problem acts as a delay on the plant being able to operate independently, extending the time period before ADEQ licensing, while still allowing the overall system to operate safely.
According to city officials, this has not put any strain on the Mingus plant, which is operating at 60% capacity.
Even before this issue arose, the high costs of the Riverfront facility had been a complaint of many in Cottonwood and the continued problems with its initial operations have not improved its political contentiousness. Before this, the plant had run into other hiccups in construction, such as shallower groundwater than expected that required a redesign of water tanks.
“It’s a $14-million lift station,” Councilman Michael Mathews, who has brought up his displeasure with the whole Riverfront project at council meetings, said of the plant pumping water back up to Mingus. “Many of us are extremely pissed off about it. I’m just more vocal about it. It was a huge screw up. It was just something we didn’t need. The Mingus plant is at 60% capacity. Why would we think about building a huge ultramodern sewer plant? It’s frustrating.”
City officials defended the decision to build the plant, pointing to potential growth in Cottonwood and the surrounding areas that would eventually overwhelm the Mingus plant. They also highlighted that when the decision was made to build it, water usage rates were higher, putting Mingus closer to 80% capacity, leading to conservation efforts in town that have lowered usage by 30%. They also stressed that a water treatment plant at the top of a hill [as Mingus is] requires pumping water uphill, wasting energy that they hope to ameliorate.
“The city’s going to grow, so you don’t want to be stymied by your ability to handle discharge,” Corbin said. “We’ve got a lot of apartment complexes coming along soon. We’ve got the Vineyards who are adding new homes on a monthly basis and Inspirations apartments. So the city’s getting ready to experience more growth than it has in the recent past. And it does add to our capacity.”
Despite the ongoing issues, city officials claim that the facility should be fixed in the near future and able to reclaim water as intended soon. Corbin said that the town had sought a potential buyer for the plant and could not find any, meaning that the town is stuck with what it has. He hopes to make the best of it and turn it into a productive part of the city’s water system.
“We’re working through making it an asset to the community,” Corbin said. “I’m not in a hurry because I’m not going to mess this up. I’m not going to turn in paperwork to ADEQ that says it’s working and then a month later it’s not working. We’re going to get it done. We’re going to get it done right. We’re going to get it so that we can start adding to our water conservation efforts, which is really the endgame — reducing the amount of water we’re taking out of the ground.”
