Objective: This study was aimed to isolate Escherichia coli by membrane filtration method from main water supplies of Erzincan, Turkey.

Materials and Methods: For this purpose, 1874 water samples were collected during 2010 in Erzincan and its towns. 100 ml water was taken for each sample, filtered through a 0.45 μM pore size cellulose membrane filter and then each filter was placed on Chromocult TBX agar plates. The plates were initially incubated at 37°C for 4 hours and then at 44°C for 18-20 hours. Blue-green colored colonies were selected and tested for indole activity. Indole-positive colonies were identified as E. coli.

Results: E. coli was detected in 53 (3.18%) potable water samples from a total of 1666 samples collected from the city center. In the towns E. coli was detected in 61 (29.33%) of the 208 potable water samples.

Conclusion: Detection of E. coli in the potable water samples is the most important indicator of fecal contamination. These results suggest that water from network of Erzincan city and its towns is not suitable for drinking or using in food preparation. These data indicate a major public health problem since several waterborne acute and chronic diseases may develop in the affected population.