Table 1.

Formula to calculate water quality indices and contamination indices.

INDEX	FORMULA	REFERENCE
ICA IDEAM Eq. (1)	$IC{A}_{njt}=\left(\sum _{\text{i}=1}^{\text{n}}{\text{W}}_{\text{i}}·{\text{ I}}_{\text{ikjt}}\right)$	(IDEAM, 2011; Caho-Rodríguez and López-Barrera, 2017; Castro et al., 2014)
ICOMO Eq. (2)	$\frac{1}{3}(I_{OD}+{I_{DB{O}_5}}_{}+I_{Totalcoliforms})$	(Ramírez et al., 1997; Valverde-Solís et al., 2015; Chavarro and Gélvez-Bernal, 2016; Samboni et al., 2007; Martinez-Ortiz and Barrero-Arias, 2018; Mosquera-Chaverra, 2016)
ICOSUS Eq. (3)	$(-0.02+0.003·TSS\left(\frac{mg}{L}\right))$	(Ramírez et al., 1997; Valverde-Solís et al., 2015; Chavarro and Gélvez-Bernal, 2016; Samboni et al., 2007; Mosquera-Chaverra, 2016)
ICOMI Eq. (4)	$\frac{1}{3}(I_{EC}+I_{Hardness}+I_{Alkalinity})$	(Ramírez et al., 1997; Valverde-Solís et al., 2015; Chavarro and Gélvez-Bernal, 2016; Samboni et al., 2007; Martinez-Ortiz and Barrero-Arias, 2018; Mosquera-Chaverra, 2016)
ICOMINERA Eq. (5)	$\frac{1}{3}(I_{Turbidity}+I_{TSS}+I_{Mercury})$	(Restrepo-Valencia, 2015; Mosquera-Chaverra, 2016)
ICOpH Eq. (6)	$\frac{{\text{e}}^{-3.108+3.45·\text{pH}}}{1+{\text{e}}^{-31.08+3.45·\text{pH}}}$	(Ramirez and Cardeñosa, 1999; Samboni et al., 2007)