Influence of hydrological conditions on the Escherichia coli population structure in the water of a creek on a rural watershed

Table 1 E. coli enumeration in creek water according to land use in the watershed, and hydrological parameters.

		Hydrological conditions				Use of the watershed^a	*E. coli*
	Sampling date (day/mo/yr)	Rainfall (mm)		Turbidity (NTU^b)	SSC^c (mg.L^-1)	Head of cattle	CFU/100 ml
		Within 5 days of sampling	On day of sampling
Wet period	21 Feb 2007	27.8	2.0	15.0	23.0	0	(1.0 ± 0.1) 10²
Dry period	3 May 2007	3.8	0.0	3.1	11.4	172	(6.2 ± 0.6) 10²
Rainfall event during dry period	11 July 2007	8.9	50.0	33.0	74.4	172	(4.0 ± 0.7) 10⁴

^a 49 septic tanks (147 eq. inhabitants) were located between 500 to 600 m from the creek. One malfunctioning septic tank (4 eq. inhabitants) was located 400 m from the sampling point.
^b Nephelometric turbidity unit
^c Suspended Sediment Concentration

ISSN: 1471-2180