AWT: GSA Guidance for Cooling Towers

From 2010 to 2020, the average water rates GSA paid increased 78%. To address rapidly escalating costs and federally mandated water-reduction targets, GSA tested six alternative water treatment (AWT) technologies. On average, these AWT technologies have reduced cooling tower water use by 26%.

This report summarizes the first four evaluations. Two more evaluations will be completed by December, 2022. View full-size infographic. [PDF - 282 KB]

GPG Findings 038, December 2018, Electrochemical Cooling Tower Water Treatment. Opportunity: How much water 
  do cooling towers routinely blow down? UP TO 50% of Cooling water is flushed To minimize scale build-up. Technology:How do Alternative Water Treatment (AWT) systems work? Increase CoC  (cycles of Concentration)while controlling scale & corrosion.AWT systems hold minerals in suspension at increased CoCs 
  Measurement and Verification. Where did M and V occur? National renewable energy Laboratory (NREL) has assessed four AWT systems, three at the Denver Federal Center and one in Savannah, Georgia. Two more assessments are underway with results due in 2020. Results: How did the four AWT systems  perform in M&V? 26% Average WATER SAVINGS Savings ranged from 23%-32%; blowdown reduced 94%-99%. 50% reduction in tower cleaning due to less scale and corrosion. MET GSA WATER STANDARDS Including controlling for legionella. 2-3 Year payback @ GSA avg. water/sewer $16.76/kgal Deployment: Where do the assessments recommend deploying AWT systems? CONSIDER FOR ALL COOLING TOWERS Anticipate changes needed to O&M contracts to transition from traditional chemical treatment to alternative water treatment systems [PDF - 282 KB]


Reference above to any specific commercial product, process or service does not constitute or imply its endorsement, recommendation or favoring by the U.S. government or any agency thereof.

Last Reviewed: 2021-09-28