What defines Maximum Residual Disinfection Level (MRDL)?

The Maximum Residual Disinfection Level (MRDL) defines the maximum concentration of disinfectants, such as chlorine or chloramine, allowed in drinking water. This regulation is in place to ensure that the water supply is adequately treated to kill harmful pathogens while minimizing potential health risks associated with excessive disinfectant levels. By regulating this maximum level, water treatment facilities can provide safe and effective disinfection while also protecting public health.

In the context of the other options, the minimum level of disinfection required for safety does not align with the MRDL's focus on maximum allowable concentration, and the standard for chemical by-products pertains to different aspects of water quality regulations. Additionally, the overall goal of drinking water treatment encompasses broader objectives, including the removal of pathogens, contaminants, and ensuring the water is safe for consumption, which goes beyond just the MRDL.