Few communities in America are more conscious of their water supply than Marana, Arizona.

Located a few miles northwest of Tucson along Interstate 10, Marana relies on Colorado River water through the Central Arizona Project (CAP), groundwater and reclaimed wastewater to deliver a reliable supply of high-quality water to its 8,000 customers.

The utility aggressively promotes conservation and recently received an award for participation in a forward-looking multicommunity project that will help reduce groundwater overdrafting across the region.

At the same time, it plans to build brand-new water treatment facilities to remove unregulated compounds from groundwater wells in two of its water systems.

“Water is critical here,” says John Kmiec, water director. “Our growth depends on it.”

New community

The town was incorporated in 1977, and water was the reason. “The city of Tucson was acquiring farmland in the area in order to secure water rights associated with the properties,” Kmiec explains. “The town was essentially established to prevent further encroachment. It’s all about water here.”

Originally, the town bought small rural water companies and operated as a rural water system for several years.   

The Marana Water Department was established in 1997, and in 2017, it was recognized as the small water system of the year by the Arizona Water Association.

The town’s original population was around 1,500 in 1977, but now is closing in on close to 50,000 by 2020. The Marana Water Department serves about 50 percent of the current population with Tucson Water serving the rest. Most of all, future growth in Marana will continue within the Marana Water Department service area.

Infrastructure

Kmiec’s department supplies water to its customers through a series of groundwater wells, aboveground storage tanks and seven independent water distribution systems. About 2,400 acre-feet of water per year are imported from the Colorado River through the CAP canal, which runs 336 miles from Lake Havasu in northwest Arizona to the Tucson area in the south.

A new water reclamation facility recycles about half a million gallons of treated wastewater to a community nature park located next to the plant where it also recharges the aquifer.

At the wellheads, water is treated with calcium hypochlorite for disinfection before it is pumped to end users.

“Marana updates its potable water plan every 10 years,” Kmiec explains. “Essentially we are transitioning from a collection of small rural water systems to a full service water and wastewater utility.”

The current infrastructure plan includes rehabilitating some of the older waterlines in the community, maintaining the water storage tanks and replacing the utility’s SCADA system.

“The recession affected our growth,” Kmiec says, “but now we are growing again.” While the majority of the distribution piping is less than 20 years old, the department is replacing some of the mains in its older neighborhoods with new PVC pipe as roads and streets are rebuilt. Most of the old piping is concrete asbestos or galvanized steel. In 2017, about 2,000 feet of older mains in a neighborhood built in the early 1950s were replaced.

Interconnectivity among Marana’s seven different water systems is the long-term strategic goal. This will be done by a series of capital projects that will start to lay the distribution piping necessary to move water back and forth from systems that are currently operated independently.

“As our community starts to fill in — conversion of farmlands into housing — we need to bring these smaller systems together into larger systems,” Kmiec says. “This will give us the necessary redundancy and reliability we need as we grow. Right now, if a well goes down, depending on the system, we may have a hard time meeting demand.”

He says the connections will balance groundwater withdrawals and energy usage and be more efficient.

Marana is also re-coating its water storage tanks as part of a 10-year preventive maintenance program. “We are doing one to two per year,” Kmiec says. “We frequently assess the condition of our reservoir assets and take a proactive approach to maintaining them.”

The tanks are constructed of steel and, depending on conditions, are being re-coated on the interior and exterior.

Another upgrade involves the SCADA system. “When we consisted of a number of smaller rural water systems, we were also using older technology,” Kmiec says. “The new SCADA system is being upgraded to a new Rockwell platform. This will take several years to convert all the assets. Once fully completed, our operators will have the ability to review and control operations without the need to be on site or in a central control center.”

Water strategy

In the old days, Arizona communities treated their wastewater and dumped the effluent in the desert. No longer. Faced with chronic drought and diminishing surface water supplies, utilities like Marana Water are doing everything possible to use water wisely and prepare for the future.

“It’s definitely a huge challenge,” Kmiec says. “We have to transition to renewable water sources as soon as possible.”

In the case of Marana, that means smart management of its allotment of Colorado River water through the CAP.

“We can either use it the same year it is delivered or bank it for long-term storage credits,” Kmiec explains.

In one innovative approach, Marana Water contracts with a large agricultural operation so that the farm uses a portion of the CAP water assigned to the utility, while Marana obtains credit for the groundwater the farm would have pumped from the aquifer. “Overpumping has led to disasters in the past,” Kmiec says. “This way, we use all the CAP water allocated to us. It just works out better for us financially and is more environmentally sustainable.”

In addition, Marana has brought its new wastewater reclamation facility online and is getting credits for the treated water it is putting back into the aquifer. The plant features a four-stage Bardenpho process, followed by sand filtration and TrojanUV disinfection system. Design flow is 1.5 mgd, with current flow around 0.5 mgd. The new facility is a Carollo Engineers design, and the construction manager was PCL.

(Arizona water credits reward utilities for banking groundwater for at least one year and allow these utilities to pump and use the water in the future.)

Water conservation

Marana Water is a member of the Water Conservation Alliance of Southern Arizona, an organization devoted to drought-proofing water-conscious desert communities in its membership. The alliance offers a variety of water conservation materials to customers, including conservation literature, tips for desert landscaping and information about water saving appliances.

Marana Water also provides the use of water meter monitors to customers who wish to identify where (i.e., appliances, leaks, etc.) in their home they are using the most water. The monitor allows them to see their water usage between their monthly meter readings, which in turn makes the customer understand where their water is going so they can set up a water savings approach.

Data on the city’s website from 2014-15 reflects about an 8 percent decrease in water usage by Marana customers and an even larger decrease during the high water usage months of June and July.

The future

With Colorado River flows diminishing and levels dropping in Lake Mead, how does Kmiec feel about a sustainable surface water supply?

“The river is under drought condition,” he says. “If Lake Mead goes below 40 percent of its normal volume, reductions may take place that will dictate the amount of water the lower states of California, Arizona and Nevada can obtain.”

If that happens, he expects “lots of negotiations about how to address the issue, involving the Bureau of Reclamation, which controls the river.”

Reduction in water supply could well impact community growth, but Kmiec applauds the Arizona Groundwater Management Act of 1980 and the water bank that Arizona has been contributing to for many years. “That could make up the difference,” he says. But he adds, “Water is always on my mind; we’re always looking for supplies.”

An award-winning approach

Marana and the nearby community water departments of the Town of Oro Valley and the Metropolitan Domestic Improvement District recently took an important step to assure adequate groundwater supplies in the future. Rather than having the different municipalities pumping from different groundwater deposits, the agencies agreed to consolidate recharged groundwater in a central location and provide each with the ability to pump to its service area as needed.

It’s a 50-year agreement called the Northwest Recharge, Recovery and Delivery System, and it won a Metropolitan Pima Alliance Common Ground Award for community collaboration.

Kmiec says a common groundwater wellfield will be constructed north of the Marana Airport west of I-10, and each community will share in a 7-mile joint pipeline that will bring the water to a central location. In turn, each entity will have its own booster station to be able to pump water it needs for its respective service area. Expected to become operational by 2023, the project will reduce the risk of individual communities exhausting separate groundwater supplies and will allow the north Tucson-area aquifer to recover from decades of overpumping.

Kmiec praises the intercommunity cooperation. “You don’t always find municipalities willing to cooperate like this.”

Keeping it clean

Contamination has been detected in two water systems in the Marana (Arizona) service area, and — as a demonstration of its commitment to clean water — the town is making a significant investment to treat the contaminants.

Perfluorinated compounds (PFCs) and 1,4 Dioxane — both unregulated compounds — have been detected in the systems at levels that exceed current Environmental Protection Agency health advisories.

Recently, the Marana Town Council voted to build two new water treatment campuses that may employ a combination of ion exchange, granular activated carbon, with advanced oxidation to deal with the compounds.

John Kmiec, water director, says the cost to build the two new facilities ranges from $12 to $15 million and most likely will be funded by the Water Infrastructure Finance Authority of Arizona, grants and service rates. The two treatment facilities are expected to be completed and put into operation by 2020. They will pump between 1,000 and 2,000 gpm and serve about 3,000 connections.

Meantime, Marana and the city of Tucson have filed a joint lawsuit against five companies that manufactured and sold a firefighting product containing certain PFCs. The suit seeks to recover all costs associated with the contamination mitigation, including the expense of the new facilities.

The Marana Council’s vote to proceed with the new clean-water facilities was unanimous. In a press release, council member Roxanne Ziegler reaffirmed the importance of water to Marana: “I do believe this town needs to provide clean water,” she says. “I am in favor of getting this done immediately.”