Broomfield, Colo. — MWH Constructors and Slayden Constructors Inc. have been awarded a contract by the City of Spokane (Wash.) to provide general contractor and construction manager services for a new, upgraded tertiary filtration system for the Riverside Park Water Reclamation Facility. This system, called the “Next Level of Treatment” would be the largest and most effective phosphate removal of its kind built in the U.S., according to the project team.

The filtration system upgrade will increase the removal of phosphorus from the effluent to more than 99 percent. The current system removes 90 percent of phosphorus, which has been associated with low oxygen levels and algae blooms that can harm aquatic life in the Spokane River and Long Lake. With additional disinfection, the new filtration system could bring the effluent in compliance with Washington State Department of Ecology “Class A” standards, allowing the water to be safely reused for irrigation, industrial processes, dust control, wetland enhancements and recharging groundwater supplies.

Construction of the $125 million upgrade is expected to begin in late 2016 and is part of the City of Spokane’s $310 million Integrated Clean Water Plan to address water quality concerns. Construction of the new system will be completed in two overlapping phases with early evaluation to ensure constructability of the new system’s proposed design. The Riverside Park Water Reclamation Facility will remain fully operational during construction.

“MWH Constructors has a strong history of working with cities, like Spokane, to construct water facilities that meet the needs of ratepayers, satisfy regulations and protect the environment,” said Michael Haarmann, vice president and preconstruction manager for MWH Constructors. “Our team of construction professionals will work closely with city officials and the design team to ensure delivery of the project in the most cost and time effective manner possible.”

MWH Constructors recently announced the acquisition of Slayden Constructors, and the teams will work collaboratively with B&E Electric as a joint venture on the project.

“This is the City’s first major public works project using a general contractor and we anticipate this structure will pay major dividends,” said Mike Taylor, engineer and program manager for the City of Spokane. “We have assembled a qualified team of professionals to ensure constructability and to ultimately improve the treated water quality in Spokane.”