Table 4. Prevalence of thermotolerant coliforms in 155 water samples obtained during the first visit and second visit to dairy farms in Paraná, Brazil, from 2012 to 2014.

Water sources	First Visit			Second Visit
	Number of sources	Number of samples	Positive Samples, TTCa (%)	Number of sources	Number of samples	Positive Samples, TTCb (%)
Spring	31	62	35 (56.5)	24	24	12 (50)
Artesian well	20	40	3 (7.5)	2	2	0
Shallow well	8	16	6 (37.5)	2	2	0
River	3	6	6 (100)	3	3	3 (100)
Total	62	124	50 (40.3)	31	31	15 (48.4)

^aThermotolerant coliforms according to the multiple-tube method;

^baccording to the chromogenic substrate method.