Gives a reference method (Standard Test) for the detection and enumeration of Escherichia coli and coliform bacteria in water for human consumption. The Standard Test is based on membrane filtration, subsequent culture on a differential agar medium and calculation of the number of target organisms in the sample. Also includes a rapid method (Rapid Test) for the detection of E. coli only within 24 h in water for human consumption, which can be useful in special cases when information is needed quickly. The Rapid Test is based on membrane filtration, subsequent culture under selective conditions and calculation of the number of E.coli in the sample.