A modified water rate structure and the establishment and promotion of water conservation significantly reduced projected demand increases and associated water supply deficits. By making customers aware of how much water they were using, the conservation program was successful. Ratepayers now have more insight into how much water they use, allowing for people to self-regulate. This created motivation for customers to reduce water use to save money and ultimately conserve water resources.
Resource optimization focused primarily on the greater use of surface water when surface water sources are abundant and resulted in significant reduction of stress on the Equus Beds Aquifer, which is the city’s primary source of groundwater. Options to develop or acquire additional water supply sources regionally were limited.
City officials also selected an innovative option centered on capturing, treating and storing intermittently available resources for future recovery and use. Equus Beds Aquifer Storage and Recovery (ASR) is a creative and innovative program used for capturing and treating water from the Little Arkansas River during high-flow periods. Treated water is then stored in the depleted areas of the Equus Beds Aquifer. ASR was structured as a dynamic program that could adjust to fluctuating water demands, changing aquifer conditions, evolving technology, resource management strategies and overall program goals.
As the centerpiece of Phase 2 of the ASR program, Burns & McDonnell provided design-build services for new surface treatment and river intake systems, which together had been projected to cost $104 million — but value engineering and optimized construction methodology helped deliver the project at $74 million, a savings of $30 million.
The unique system combines membrane filtration and advanced oxidation to remove atrazine and other contaminants from as much as 30 million gallons of raw water from the Little Arkansas River, operating only when the river is above established flow triggers. Coordination with the Kansas Department of Health and Environment was a critical element of the planning, design and construction. During the permitting process, protecting groundwater quality in the project area was a priority.
The treated water is used both to recharge the 900,000-acre aquifer and establish a source of supply for future use. The focus and innovative aspect of ASR is the utilization of a transient water resource that is normally unavailable when it would be needed.
The final design and construction of the river intake and treatment facilities was completed as a design-build project by the team of Burns & McDonnell, Alberici Constructors and CAS Constructors. The recharge wells and basins were designed by Burns & McDonnell and constructed as a design-bid-build project.