AZTEC — Anthony Garcia, an operator at Aztec's wastewater plant on South Oliver Drive, notes an irony in the name of the plant at which he works -- waste.

Perhaps a better name might be water recycling plant.

The city of Aztec, with a growing population close to 7,000, treats up to 1.2 million gallons of wastewater daily.

"The water is always coming in," Garcia said.

Every fiscal year, which starts July 1, Aztec takes new bids on chemical treatment for its water and wastewater plants. On Tuesday, city commissioners approved another year's purchase of treatment chemicals.

While prices have gone up, some firms that contract with the city have lowered costs.

Austin Randall, a purchasing agent for the city's finance department, said prices and firms that bid on contracts fluctuate each year, but the city is often able to secure savings because of a trend in specialized bidding.

In the past, vendors bid whole contracts containing many, if not all, of the materials or services needed. But more vendors are now specializing in certain products, and competition limits vendors' ability to bid on all items the city needs.

To clean the water at Garcia's plant, three chemicals -- ferric chloride, polymer and methanol -- are injected into the water after ultraviolet light treatment. In one year, through competitive bidding, the three can run upwards of $70,000, plus tax.

High-strength chemicals -- water-softener salts, liquid aluminum sulfate and non-ionic polymer -- are used to remove silt to make the water drinkable. The chemicals used at the water-treatment plant on Navajo Dam Road average about $22,000 in costs before tax.

The city's wastewater plant receives used water and raw sewage every time a toilet is flushed, a sink faucet is run or a shower is taken. During the summer months, the combination of drought conditions and nearly 100 degree temperatures mean even more water rushes in.

And too often it's riddled with unwanted items like paper towels, paper, tampons and plastic tampon applicators, Q-tips and sanitary napkins.

"We get tree roots that come in through the sewer pipes, but we also screen out a whole lot of things that don't belong," Garcia said.

Thanks to a recent overhaul of the plant two years ago, much of the screening work to clear the sewage of debris is done by machines. Still, Garcia and one other full-time employee at the plant oversee operations, checking meters and ensuring the treatment process is effectively removing phosphorous and nitrogen from the water.

To offset rising costs and aging infrastructure, the city has made significant investments in updating and replacing older, less-efficient equipment at its treatment plants in recent years.

The Navajo Dam plant underwent $400,000 in automation upgrades this spring and will likely be complete with an additional $500,000 in upgrades planned for later this year.

Garcia said the improvements at the wastewater plant have increased efficiency and lowered the amount of chemicals needed, but consumer use drives the volume the plant must clean.

"Water use is definitely up in the warmer months, but, even in the winter, the usage is up there, too," he said. "People are pretty consistent, with peak hours in the morning, at lunch and the evenings. It's probably awareness, more than the price, that may affect how much we all use."

James Fenton covers Aztec and Bloomfield for The Daily Times. He can be reached at 505-564-4621 and jfenton@daily-times.com. Follow him @fentondt on Twitter.