Benefits of Soft Water Makeup for Cooling Tower Operation

Paper Number IWC-07-01 Presented at 68th Annual International Water Conference 2007

Soft water is generally considered unacceptable for use as cooling tower makeup. This study indicates, however, than in many applications, soft water is a better source of cooling tower makeup than untreated, hard water.  The use of soft water allows the tower to run at higher cycles of concentration without the need for supplemental acid or scale inhibitor additives.  A higher cycle of concentration offers the advantage of reducing the makeup water requirements and minimizing wastewater discharge.  The higher alkalinity and pH environment produced by the soft water reduces the corrosion of system metals and helps limit the growth of microorganisms commonly found in cooling water systems including Legionella, the causative agent for Legionnaire’s disease. This paper documents and defines the specific applications where soft water makeup offers distinct advantages over the use of untreated, hard water.

Benefits-of-Soft-Water-Makeup-for-Cooling-Tower-Operation-IWC-07-01