Archer Western recently completed the expansion and process upgrades to EPCOR’s White Tanks Regional Water Treatment Plant in Surprise, Ariz. Located near the foothills of the White Tank Mountains, this plant provides potable water to communities in the west-central portion of Maricopa County. The expansion portion of the project consisted of adding a new 38 MG raw water reservoir, additional raw water and finished water vertical turbine pumps, 33 MGD UV disinfection units, an additional DAF basin, addition of an enhanced treatment process, two additional solar drying beds, two gravity media filters, wastewater clarifier and chemical feed upgrades, and an electrical and control building. The plant’s treatment process increased its total firm capacity from 13.4 MGD to 26.7 MGD and increased its total capacity from 20 MGD to 30 MGD.

The enhanced treatment process upgrades to the plant involved the design and construction of the first CoMag ballasted clarification system in Arizona. The system uses an inert iron ore by-product called magnetite which when used along with chemical coagulant, settles out solids as much as 30 times faster than conventional treatment. It also utilizes magnetic recovery drums which recover up to 99% of the magnetite ballast to reduce operational cost. CoMag® was specifically implemented to address high turbidity water events, such as heavy rain and storm runoff in the summer, which can result in a surge of particles and mud. These surges can disrupt the plant’s treatment ability and put the plant under stress to continue to provide compliant drinking water. Though magnetite clarification has been used before in the U.S. for wastewater, this project is the first in the country to use the CoMag® system on the water supply end.

“The expansion of the White Tanks facility along with incorporating this new treatment technology is one of the most significant projects EPCOR has taken on to date in the US,” said Andy Brown, director of engineering at EPCOR Water. “Having Archer Western as our construction partner on this project gave EPCOR a high level of confidence that it would result in a safe and successful project.” 

Archer Western’s project portfolio with EPCOR also includes Water Plant 16 Booster Pump Station located in the Verrado master community in Buckeye, Ariz., and the Luke 303 Water Reclamation Facility in Litchfield Park, Ariz.