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What is the equivalent % of 3 log removal?
99.0%
99.5%
99.9%
99.99%
The correct answer is: 99.9%
The concept of log removal is used to quantify the effectiveness of a treatment process in reducing microorganisms in water. Each "log" represents a tenfold reduction in the concentration of a particular microorganism. Achieving 3 log removal means reducing the number of target pathogens by 1,000 times. To translate this into a percentage, the formula for calculating this is: 1 - (1 / 10^n) where n is the number of logs removed. In this case, for 3 logs: 1 - (1 / 1,000) = 1 - 0.001 = 0.999, or 99.9%. This means that if you achieve 3 log removal, you are safeguarding the water supply by ensuring that 99.9% of the targeted pathogens have been removed or killed. This high level of log removal is critical in preparing drinking water to meet health standards and ensuring public safety.