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

Table 4

Analysis of mean differences and confidence intervals for E. coli levels in the wet 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
Bore hole	3.742	7	0.007	1.000	0.37	1.63
Canal	2.292	2	0.149	59.667	−52.32	171.66
Dam	7.814	14	0.001	39.867	28.92	50.81
Hand-dug well	5.358	14	0.001	1.467	0.88	2.05
River	2.982	2	0.096	4.333	−1.92	10.58
Stream	7.745	16	0.001	20.765	15.08	26.45