Parameters	BIS standards (IS 10500: 1991) [55]		WHO (2002) [56]	WHO (2008) [56]	WHO (2011) [57]	US EPA (2009) [58]	UE [59]
Parameters	Limite desirable	Limite permitted	WHO (2002) [56]	WHO (2008) [56]	WHO (2011) [57]	US EPA (2009) [58]	UE [59]
pH	6.5 - 8.5	6.5 - 8.5	6.5 - 9.2
Fe (mg/L)	0.3	1	0.3	0.3	0.3	0.3	-
Cd (mg/L)	0.01	-	0.005	0.003	0.003	0.005	0.003
Cu (mg/L)	0.05	1.5	1	2	2	1.3	2
Zn (mg/L)	5	15	5	3	3	5	3
Pb (mg/L)	0.05	-	0.05	0.01	0.01	0.015	0.01
Ni (mg/L)	-	-		0.15 - 13	0.07	-	0.02
Co (mg/L)	-	-		0.04	-	-	-