What is the standard for turbidity in drinking water according to MCL?

The correct answer indicates that the maximum contaminant level (MCL) for turbidity in drinking water is set at less than 0.3 NTU (Nephelometric Turbidity Units) in at least 95% of samples. This standard reflects the importance of maintaining water clarity to ensure safe drinking water, as turbidity can indicate the presence of pathogens, sediment, and other harmful contaminants.

Regulatory agencies, such as the Environmental Protection Agency (EPA), have established this standard to protect public health, emphasizing that consistently low turbidity levels correlate with effective filtration and disinfection processes. Achieving less than 0.3 NTU in a majority of samples helps ensure the effectiveness of treatment processes and the overall safety of the drinking water supply.

Other provided options suggest different thresholds or sampling percentages that do not align with the established standards. For instance, thresholds that are higher than 0.3 NTU do not ensure the same level of water quality and safety. Lower or less frequent sampling percentages also deviate from regulatory expectations designed to provide a reliable measure of water quality over time. By adhering to this standard, water suppliers can maintain safe, clear drinking water that minimizes health risks associated with turbidity.