Table 2.

Water quality indexes and scales.

Canadian Council of Ministers of the Environment water quality index		US National Sanitation Foundation water quality index
Water quality index value	Rating of the water quality	Water quality index value	Rating of the water quality
95–100	Excellent	90–100	Excellent
80–94	Good	71–90	Good
60–79	Fair	51–70	Medium
45–59	Marginal	26–50	Bad
<44	Poor	0–26	Very bad