This chapter sheds light on the quality and quantity issues of water requirements in a typical dairy plant. Water is an important utility for dairy plants as it governs the hygiene of dairy plants. Water is used in large quantities for cooling, washing and sanitation, production of steam and other operations in dairy plant. The availability of adequate water of suitable quality is a primary consideration in the selection of site and in the establishment of a dairy processing plant. Water is needed in the processing plant for generating steam, for cleaning, as an ingredient in finished products, as a heat exchange medium in heating and cooling operations, for cleaning plant and equipment, and for protection against fire. Dairy plant use water in all three states: solid (ice), liquid (water) and vapor (steam). Since the requirements of water for a dairy plant is comparatively large, it may be difficult to meet the demand from a municipal supply.