Issues such as water scarcity as well as other environmental concerns have prompted cooling system water consumption approaches such as operating at higher cycles of concentration and using treated municipal or industrial wastewater as makeup water. These approaches elevate potential fouling and microbiological activity, particularly when using wastewater effluents containing phosphate and other inorganic ionic species and organic contaminants. The system water chemistry coupled with operating conditions generates stresses which may potentially increase cooling water system fouling and corrosion rates. This article illustrates a technological approach to treat cooling systems operating under stressed conditions and considers treatment program efficacy for Metrology and Analytical Technology metal-phosphate scale formation on equipment surfaces for numerous stressed conditions.