The Splash

TowerAssure Program Provides Cooling System Protection, Improves System Efficiency and Reduces Water Usage at a Southern U.S. Airport

U.S. Water’s successful program at a nearby facility resulted in an invitation from a Southern U.S. airport to propose an alternate treatment program for their existing cooling tower system.  The airport practiced sustainable water usage by utilizing softened graywater in its cooling tower system, but the responsible decision to move away from domestic city water to graywater quickly led to concerns regarding the long-term system integrity. The corrosive properties of the graywater were negatively affecting the cooling system leading to severe corrosion, excessive biological growth and a loss in chiller efficiency. The chillers would frequently shut down due to approach temperatures exceeding safe operating limits, and without proper treatment soon, the Iron Related Bacteria (IRB) and Sulfate Reducing Bacteria (SRB) could cause severely damaging pitting corrosion to the system.
 
The U.S. Water team conducted a site survey to collect water samples and meet with the facility staff to gain a complete understanding of the issues they were experiencing. After reviewing the lab results and collaborating with U.S. Water’s technical team, U.S. Water recommended the TowerAssure™ program, an integrated treatment solution for scale, corrosion and bacteria control. The TowerAssure program combines leading edge software, cellular communications, automation and monitoring into one simplified solution. Its panel-mounted design allowed for an easy transition from the facility’s existing treatment program to U.S. Water’s solution.
 
The TowerAssure panel was integrated with a customized chemical program that included a corrosion and scale inhibitor, bacteria control agents to treat the corrosive graywater. To further treat the biological fouling issues, the on-site staff made adjustments to the mechanical operations by changing the chiller rotation schedule allowing water to flow through the chillers and cooling towers multiple times per week. This eliminated water stagnation, reducing the biological loading on the towers. The online communications and daily dashboards offered by TowerAssure allowed the U.S. Water representatives to identify issues immediately and work with facility operators to make prompt adjustments. In addition to reviewing the daily dashboards, U.S. Water representatives provide on-site service two-to-three times per month.
 
Corrosion coupons show significant improvements after a 90 day period.After the solution was implemented there was an immediate decrease in the amount of water used. In one month, the integrated approach of effective chemistry, controlled by the TowerAssure monitoring system, allowed for optimization of the water use. The increase in cycles of concentration, or the ratio of water brought into the cooling loop compared to what is discharged, resulted in the facility saving 250,000 gallons of water. In addition to the significant reduction in water usage and costs, the chillers are no longer shutting down and efficiency has increased. The customized chemical program has addressed the corrosive graywater as shown in photo on the left, reducing corrosion rates down to industry standard of less than 3 mils per year on carbon steel piping.
 
Together, U.S. Water and this facility are setting a new level of system expectations. The success in the airport’s system has led to U.S. Water becoming the exclusive water treatment vendor, evaluating additional opportunities for cost and water savings on site, and partnering on an upcoming new construction project.