Researchers track viruses with viruses to keep taps safe

Researchers have reported a novel means of testing sources for UK drinking water production for viral contamination: by monitoring the presence of somatic coliphages – viruses that infect bacteria such as E coli found in human and other animal faeces – as an indicator of other gut disease-causing (pathogenic) viruses arising from the same sources (enteric viruses).

Their aim was to “enhance risk-based preventative strategies for maintaining drinking water safety by providing precise data on the prevalence and elimination of enteric pathogenic viruses at drinking water treatment plants in the UK.”

The researchers claimed that their findings could “greatly assist in evaluating treatment plant operation, ultimately contributing to the reduction of exposure to viral risk and regulatory non-compliance.”

Samples from 13 treatment plants were taken from diverse source waters as well as from mid-treatment stages and final drinking waters. They included high-risk sites based on microbial risks from agricultural runoff, sewage discharges, pesticides and recalcitrant pollutants.

Inter-treatment samples came from various processes including coagulation/clarification, ozonation, chlorination, activated carbon filtration and membrane filtration.

The study, the researchers said, “confirms low baseline levels of somatic coliphages in most raw waters and the effectiveness of multiple treatment barriers in UK drinking water for coliphage removal.”

UKWIR said: “Future integration of this study's catchment-specific data into a microbial risk assessment model could greatly assist in evaluating treatment plant operation, ultimately contributing to the reduction of exposure to viral risk and regulatory non-compliance.”