Efficiency of Treatment Plant and Drinking Water Quality Assessment from Source to Household, Gondar City, Northwest Ethiopia

Table 4

Water quality index of selected physicochemical parameters of drinking water in Gondar city, Northwest Ethiopia, June 30 to August 30, 2020.

Parameters	WHO standard (Si)	Ci			qi (%)	SIi
pH	6.5–8.5	6.88	4	0.125	80.9	10.11
DO (mg/L)	>6	6.5	4	0.125	108.3	13.54
Turbidity (NTU)	5	5.1	5	0.1563	102	15.94
EC (μS/cm)	1000	170.6	3	0.0934	17.06	1.6
Nitrate (mg/L)	50	50.7	5	0.1563	101.4	15.85
Total hardness (mg/L)	300	62.7	3	0.0934	20.9	1.95
Iron (mg/L)	0.3	0.15	3	0.0934	50	4.67
Fluoride (mg/L)	1.5	1.17	5	0.1563	78	12.19
—	—	—	= 32	—	—	WQI = 76

Note. Ci = concentration of each parameter,  = weight of each parameter,  = relative weight, qi = quality rating scale, SIi = parameter subindex, DO = dissolved oxygen, and EC = electrical conductivity.