What percentage of log removal is typically required to effectively eliminate viruses from water systems?

The requirement for a 99.99% log removal to effectively eliminate viruses from water systems reflects the high level of treatment necessary to ensure safe drinking water. In water treatment, the term "log removal" indicates the factor by which the pathogens, including viruses, are reduced. A 4-log removal, which corresponds to a 99.99% reduction, is generally accepted as a significant standard for public health safety.

This level of treatment is crucial because viruses can be highly infectious and present in very low concentrations, making them challenging to detect and eliminate. A 99.99% removal rate significantly decreases the likelihood of any remaining viruses surviving through the treatment process, protecting consumers from potential health risks associated with viral contamination in drinking water.

The other percentages suggest lower levels of treatment, which may not suffice for effectively ensuring safe drinking water from viral pathogens.