According to the Interim Enhanced Surface Water Treatment Rule, what is the turbidity requirement for combined filter effluent?

The correct answer reflects the regulatory standards set by the Interim Enhanced Surface Water Treatment Rule, which aims to ensure the safety and quality of drinking water by minimizing pathogens and other contaminants. According to this rule, the turbidity requirement for combined filter effluent is indeed less than or equal to 0.3 NTU (Nephelometric Turbidity Units) in at least 95% of samples collected over a defined period. This specific standard is crucial because higher turbidity levels can indicate the presence of harmful microorganisms, and thus maintaining low turbidity is essential for effective water treatment and public health protection.

The emphasis on achieving this standard in 95% of samples rather than 90% or any different measure demonstrates the rigorous approach to water quality management under this rule. This threshold helps ensure that the water supply remains consistently safe for consumers.