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Cooling Tower Water Softening and Disinfectant System

Solution Overview

Engineers at Phoenix Sky Harbor International Airport developed an innovative cooling tower water treatment system that combines water softening technology with an environmentally friendly disinfectant generator.[2][3] This approach addresses one of the Southwest's most significant water consumption challenges, as cooling towers can account for up to half of all water use in some commercial buildings in the region.[1][4] The pilot project demonstrated that softening the make-up water increases the cycles of concentration and reduces water use by 20%.[4][5][6]

Technical Components

The system integrates a water softening mechanism with an environmentally friendly disinfectant generator installed on cooling towers at Terminal 3, Terminal 4, and the Rental Car Center.[2][3] This combination reduces the amount of chemicals needed to keep pipes clean and increases the number of times water can cycle through the towers before being discarded.[1] A principal factor of this technology is that it can be scaled up or down in size to accommodate almost any size cooling tower.[4] The water meter providing make-up water for Terminal 4's cooling towers ranks as one of Phoenix's highest volume water meters, highlighting the scale of water consumption at these facilities.[4]

Implementation Details

The technology was pioneered at Phoenix Sky Harbor International Airport through ingenuity and experimentation, with engineers achieving dramatic results.[2][3] The project was so successful that the systems became a standard central plant design, with similar installations completed at the Terminal 3 Central Plant and Rental Car Center Central Plant.[4] This cooling water treatment system was also installed as part of the Terminal Modernization Project, and a system was being installed in the Rental Car Center.[4] The successful implementation at the airport became the basis for a broader grant program when Mayor Kate Gallego and the Phoenix City Council members voted unanimously to make funding available to companies interested in using leading-edge technology to save water and protect the environment through the new 'Blue Bank' partnership.[2] BlueCommons and BWS provide loans to qualified companies that want to incorporate cooling tower projects in their own buildings and campuses.[2][3]

Benefits and Impacts

The Cooling Tower System Upgrade was successfully completed, reducing water use by 20%.[4] The large-scale cooling tower water treatment technology at Phoenix Sky Harbor International Airport has saved 31 million gallons of water at one of the terminals since implementation more than three years ago.[1] Initial estimates inferred that the water savings would be 10 million gallons per year.[4] More than two years after the project was concluded, results showed more than 21 million gallons of water and thousands of pounds of chemicals saved in 2019.[4] The cost savings of these upgrades are achieved by the elimination of purchasing biocide chemicals, reduced water use, and increased system life.[4] Relatively simple upgrades to existing cooling systems can substantially increase the number of cycles during which the same water can be used in cooling.[2]

Climate Adaptation Relevance

This technology directly addresses water scarcity challenges intensified by climate change in the Southwest, where cooling demands place enormous pressure on limited water resources. By enabling cooling towers to operate with significantly less water consumption, the system enhances Phoenix's resilience to drought conditions and reduces vulnerability to water supply disruptions. The scalability of the approach allows for widespread adoption across commercial buildings, multiplying water conservation benefits throughout the urban environment.

Business Analysis

The highly successful large-scale cooling tower water treatment technology pioneered at Phoenix Sky Harbor International Airport serves as the basis for the grant program.[2][3] The Blue Bank partnership provides a financial mechanism for scaling the technology, with BlueCommons and BWS offering loans to qualified companies that want to incorporate cooling tower projects in their buildings and campuses.[2][3] The business model demonstrates strong financial viability through multiple revenue streams, including elimination of biocide chemical purchases, reduced water utility costs, and increased system life.[4] The technology's ability to be scaled up or down to accommodate almost any size cooling tower expands the addressable market across diverse commercial building types.[4] Municipal support through unanimous City Council approval signals strong policy backing for water conservation investments, creating a favorable regulatory environment for adoption.[2]

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