Escherichia coli as a Tool for Disease Risk Assessment of Drinking Water Sources

Table 3

Analysis of mean differences and confidence intervals for E. coli levels in the dry season (test value = 6; the mean difference is significant at ).

Water sources	T	df	Sis (2-tailed)	Mean difference	95% confidence interval
					Upper limit	Lower limit
Borehole	2.376	7	0.049	0.625	0.00	1.25
Canal	5.147	2	0.036	47.667	7.82	87.52
Dam	4.800	14	0.001	38.067	21.06	55.08
Hand-dug well	4.525	14	0.001	0.933	0.49	1.38
River	—	2	—	—	—	—
Stream	4.569	16	0.001	15.059	8.07	22.05