What is the equivalent percentage of 4 log removal?

To understand the equivalent percentage of 4 log removal, it’s important to grasp what "log removal" means in the context of water treatment. The term "log removal" refers to the logarithmic measure of the reduction of pathogens or contaminants. Specifically, a "log" corresponds to a tenfold decrease. Therefore, achieving 4 log removal indicates that the number of pathogens or contaminants has been reduced by a factor of 10,000 (which is 10 raised to the power of 4).

To convert this into a percentage, you can use the following formula:

1 - (1 / 10^n)

In this case, n is 4 (for 4 log removal). Plugging in the numbers:

1 - (1 / 10^4) = 1 - (1 / 10,000) = 1 - 0.0001 = 0.9999

To express this as a percentage, you multiply by 100:

0.9999 x 100 = 99.99%

This calculation shows that 4 log removal equates to a 99.99% reduction of pathogens or contaminants in the water. This level of removal is significant because it indicates a high degree of effectiveness