- Q. Can lake or river water be used when mixing mortar for masonry construction?
A. Water for use in mixing mortar for masonry construction must be fit for human consumption. Lake or river water could contain organic impurities that might affect the mortar's properties. Water from these sources could also contain high concentrations of salt that could contribute to efflorescence. The Brick Industry Association in Technical Note 8 states, "If water is clean, potable, and free of deleterious acids, alkalies, or organic materials, it is suitable for masonry mortars."