Assessment of Drinking Water Quality in Urban Water Supply Systems: The Case of Hawassa City, Ethiopia

Table 1

Mean values and standard deviations of physicochemical parameters at the source, reservoir, and tap water samples.

Parameters	Units	11 samples from source		4 samples from reservoir		6 samples from tap water		Standard
		Mean	Std.	Mean	Std.	Mean	Std.	ES	WHO
TDS	Mg/l	190.90	58.82	67.30	32.77	170.17	42.95	1000	1000
Temp.	°C	21.91	0.98	22.50	1.29	21.83	0.75	—	<15
EC	μS/cm	339	99.68	72.75	38.39	338.67	85.17	1500	1000
Turbidity	NTU	24.45	16.21	1.55	0.45	2.48	0.38	7	5
pH	—	7.13	0.37	7.54	0.07	7.69	0.24	6.5–8.5	6.5–8.5
Ca	Mg/l	71.04	52.08	32.50	3.42	21.73	9.66	—	75
Mg	Mg/l	9.90	3.40	12.00	3.83	10.33	1.86	50	50
F	Mg/l	1.10	1.06	1.30	0.31	1.04	0.37	3	1.5
NO3	Mg/l	3.776	2.43	2.73	0.38	2.23	0.58	50	50
SO4	Mg/l	4.633	4.95	7.00	6.24	0.35	0.81	—	250
PO4	Mg/l	0.337	0.22	0.43	0.34	0.54	0.11	0.02	0.05
TH as CaCO3	Mg/l	89.864	25.95	30.00	24.15	52.50	8.22	300	300
Alkalinity	Mg/l	162.5	40.88	187.50	46.64	239.17	42.83	—	200
Residual chlorine	Mg/l	4.51	4.04	0.08	0.03	0.00	0.00	0.5	0.2–0.5