For a 3-log removal requirement of Giardia Lamblia, what percentage of organisms can survive?

To achieve a 3-log removal of Giardia Lamblia, it is important to understand that a "log removal" refers to a tenfold reduction in the number of organisms present. A 3-log removal means that the process must reduce the population by a factor of 1,000, meaning that only 1 out of 1,000 organisms can survive.

When you calculate the percentage of organisms that can survive after a 3-log removal, it is equivalent to a survival rate of 0.1%. This is derived from the fact that if you have 1,000 organisms before treatment, a 3-log removal requires you to have no more than 1 organism remaining after treatment. Consequently, the percentage of organisms that can survive would be calculated as (1 surviving organism / 1,000 original organisms) * 100, resulting in a survival percentage of 0.1%.

This alignment with the log removal definition is crucial for water treatment processes aimed at ensuring public health by effectively reducing pathogens in water supplies. Understanding the concept of log removal is key for operators working to meet regulatory standards for potable water safety.