. 2014 Dec 10;187(1):4163. doi: 10.1007/s10661-014-4163-1

Table 3.

Ranges of water quality for the WQI

Value of WQI	Water quality	Restrictions on use for human consumption^a
90–100	Excellent	With disinfection
70–90	Good	Simplified treatment
50–70	Fair	Conventional treatment
25–50	Bad	Advanced treatment
0–25	Very Bad	Unsuitable

Comitesinos (1990) and modified by Almeida and Schwarzbold (2003)

WQI water quality index

^aBased on Brasil (2005)