What is the allowable unit limit for color in water, according to Secondary MCL?

The allowable limit for color in water, according to Secondary Maximum Contaminant Levels (MCLs), is set at 15 units. This standard is established to address aesthetic considerations in drinking water, as color can affect the visual appearance and palatability of water, even though it may not necessarily pose a health risk. Secondary MCLs are guidelines provided to water suppliers to help ensure that water is acceptable for consumer use and meets certain quality standards.

While the other options present various limits, only the 15 unit threshold aligns with the regulations set forth for acceptable levels of color in drinking water under the Secondary MCLs. The emphasis is on maintaining water quality for consumer satisfaction rather than health safety alone, which guides the standards enacted for properties like color.