Like many areas in the western United States, Arizona’s water supply is threatened. The Arizona Municipal Water Users Association (AMWUA) reported the state has been in drought for more than 20 years. Climate change and over-allocation of the Colorado River system — which provides 45 percent of the water supply to AMWUA members — have increased pressure on the state’s water infrastructure.
Glendale, a fast-growing community just 14 miles northwest of Phoenix, is one of those communities tasked with ensuring that its residents have sufficient water supply amid the shortage. Recently-completed improvements at Glendale’s Arrowhead Ranch Water Reclamation Facility will support that objective.
Glendale receives about 44 percent of its water from the Colorado River, 44 percent from the Salt and Verde Rivers, and 6 percent from groundwater. The remaining 6 percent comes from reclaimed water, which is cleaned and used for non-potable purposes such as landscaping by residents in Arrowhead Lakes and two nearby golf courses.
The Arrowhead Ranch facility was constructed in 1985 and permitted in 1994. Over time, however, the facility needed improvements and replacements. The facility began a $30 million improvement project in 2014 with a facility assessment, and construction began in 2017.
The scope of work on the $30 million project was extensive. The challenge was keeping the facility operational and maintaining regulatory compliance while construction teams made the necessary improvements.
“Different areas were under construction at different times,’’ Karla Camou Guerra, Glendale’s Water Services superintendent said. “[By completing construction in this way], we maintained operations and regulatory compliance during the duration of the project.”
Improvements included upgrades to the headworks screening facility, where three new fine screens were installed; replacing grit removal equipment; constructing a new splitter box, which separates influent flow into multiple streams and routes water to clarifiers; constructing new cloth filters at tertiary filter facilities; installing mixed liquor recycle pumps to three aeration basins; replacing the existing odor control system; installing a new water pump for non-potable water; and improving electrical components throughout the plant.
Water at the Ranch
Arrowhead Ranch is the largest user of reclaimed water in Glendale and uses the water to fill lakes and water golf courses on property. All effluent produced at the reclamation facility is used in the Arrowhead Ranch community.
“Instead of using potable water, effluent is used for Arrowhead Ranch’s artificial lakes and golf courses,’’ Guerra said. “A portion of effluent is recharged during the winter months and then withdrawn from wells for use in the summer. A little less than 3,000 acre-feet of effluent is consistently used by the Arrowhead Ranch community over the last 10 years.”
Arrowhead Ranch has a population of a little more than 86,000 people (about 33 percent of Glendale’s total) and has flourished over the years. Once a citrus ranch where oranges and lemons were produced, it is now an area rich with master planned communities. The Legend at Arrowhead golf course, designed by Arnold Palmer, and the associated Arrowhead Country Club attract players from all over, while the area’s Thunderbird Park and Lake Pleasant Regional Park are also widely used for recreation.
The lifestyle, warm year-round weather, easy commute to downtown Glendale and proximity to Phoenix, just 35 miles away, are among the reasons why the area’s population has grown 11,799 percent since 2000.
Keeping the Water Flowing
The primary challenge in the project was maintaining operations while the facility was built.
“The challenges were overcome by careful planning, attention to detail, site investigation and input from all parties involved,’’ Guerra said.
The first step completed was the installation of aeration basin pumps in 2018. A lot of progress was completed in 2019, beginning with electrical improvements, which were finished in March, and concluding with the new pump station, which was finished in September. Two odor control systems, the splitter box and clarifier drives and tertiary facilities were also completed in that year.
More work was finished in 2020, and the entire project was completed in the spring of 2021.
Accessing Equipment
One challenge for workers at wastewater treatment plants is accessing valves, filters and other equipment. Engineers specified components from The BILCO Company, a designer and manufacturer of specialty access products, for Arrowhead Ranch plant workers to reach that equipment.
The BILCO products used in the design included roof hatches, thermally broken roof hatches, ladder safety posts, aluminum floor doors and roof hatch railing systems. They were procured by MGC Contractors from Foster Engineered Products. Carollo Engineers worked with MGC and the City of Glendale team to design the facility.
“The BILCO products were selected due to their durability, and they were able to provide the safety handrails,’’ said Keith McClure, project manager for MGC Contractors. “It was a difficult project because of the continuous operation. There was a lot of bypass pumping that we worked out with the city to keep [the facility] operating at all times.”
BILCO floor doors are frequently installed at water treatment plants. The aluminum construction is ideal for corrosive environments, and are constructed with a channel frame for use in exterior applications where there is a concern for liquids entering the access opening.
The company manufactures a broad range of specialty access products for use in commercial applications. Products come in standard sizes and can be custom-engineered to meet unique access requirements.
Protecting Resources
Guerra views her role as more than Glendale’s Water Services Superintendent. She is an environmentalist, and her role is to protect the city’s future water allocation for residents.
“Glendale has provided safe, reliable and quality water to residents and businesses in the community for 100 years, in addition to providing wastewater treatment services,’’ she said. “Glendale is dedicated to providing residents with quality water to maintain public health, promote recreation opportunities, industry and the quality of life for its residents and future generations.”
While the overhaul was a lengthy process, the new Arrowhead Ranch facility will reduce operational and maintenance costs, reduce electrical vulnerability and support current and future regulatory compliance. WW
About the Author: Thomas Renner writes on building, construction, engineering, and other trade industry topics for publications in the U.S. and Canada.
Published in WaterWorld magazine, November 2021.
