Figure 7-1. Typical Stiff diagrams for basement wells. The main ionic components that differentiate this water type from others are: Cl^-1, ranging from 900 to 1000 mequiv/l, Na⁺¹, ranging from 300 to 400 mequiv/l, and Ca⁺², averaging 600 mequiv/l. Particularly, Ca⁺² value for C313 well exceeded 1700 mequiv/l.