Stress variations in any cooling-water system bring about changes in the potential for scale, corrosion, and fouling. The ability to monitor the changing potential for these operational problems, detect upsets, and take appropriate, corrective action becomes increasingly important as the systems are pushed harder to reduce total cost of operation.Over the past 2 years, new methods for managing open industrial cooling-water systems based on the actual stresses placed upon them have been developed and evaluated. This article discusses three applications in which variation in system stress presented the potential for scale, corrosion, and microbial fouling. Operational data will show how the...