Please find the link for the following US EPA method
Method 1601: Male-specific (F+) and Somatic Coliphage in Water by Two-step Enrichment Procedure (April 2001)25 (PDF, 40 pp., 463 KB)
Summary - This document (EPA 821-R-01-030) describes an enrichment procedure for detecting male-specific and somatic coliphage in groundwater and other waters. Method 1601 describes a qualitative (presence/absence) two-step enrichment procedure for coliphage. A 100-mL or 1-L ground water sample is supplemented with MgCl2 (magnesium chloride), log-phase host bacteria (E. coli Famp for male-specific coliphage and E. coli CN-13 for somatic coliphage), and tryptic soy broth (TSB) as an enrichment step for coliphage. After an overnight incubation, samples are spotted onto a lawn of host bacteria specific for each type of coliphage, incubated, and examined for circular lysis zones, which indicate the presence of coliphages.