In many cases, desalinated water is blended with other sources before or during storage, but whether it is required depends on local water quality goals and supply conditions. Desalinated water is very low in minerals, which makes it slightly unstable and potentially corrosive if used alone. Blending it with groundwater or treated surface water can increase hardness and alkalinity naturally, reducing the need for extensive chemical adjustment.
Blending is also used to balance taste and consumer preference. Communities accustomed to mineral-rich water sometimes find pure desalinated water “flat,” so mixing it with other sources helps produce a more familiar profile. In large supply systems, blending can also improve reliability by diversifying water inputs—if the desalination plant slows down or stops, other sources can still contribute to the mix.
