A monitoring program was undertaken to assess the microbial quality of greywater
collected from 93 typical households in Melbourne, Australia. A total of 185 samples,
comprising 75 washing machine wash, 74 washing machine rinse and 36 bathroom
samples were analysed for the faecal indicator Escherichia coli. Of these, 104 were also
analysed for genetic markers of pathogenic E coli and 111 for norovirus (genogroups GI and
GII), enterovirus and rotavirus using RT-PCR. Enteric viruses were detected in 20 out of the
111 (18 ) samples comprising 16 washing machine wash water and 4 bathroom samples.
Eight (7 ) samples were positive for enterovirus, twelve (11 ) for norovirus genogroup GI,
one (1 ) for norovirus genogroup GII and another (1 ) for rotavirus. Two washing
machine samples contained more than one virus. Typical pathogenic E. coli were detected
in 3 out of 104 (3 ) samples and atypical enteropathogenic E. coli in 11 (11 ) of samples.
Levels of indicator E. coli were highly variable and the presence of E. coli was not associated
with the presence of human enteric viruses in greywater. There was also little correlation
between reported gastrointestinal illness in households and detection of pathogens in