What is the maximum acceptable color in a public water supply measured in units?

In the context of water quality standards, the maximum acceptable color in a public water supply is acknowledged to be measured in units called "Hazen units" or "APHA color units." For drinking water, the regulatory limits typically suggest that the maximum color should be no more than 15 units. This limit helps to ensure water is aesthetically pleasing and suitable for consumption, as excessive color can indicate the presence of organic material or other impurities.

The choice of 15 units aligns with the common standards set by various authorities, including the Environmental Protection Agency (EPA). Maintaining water within this guideline is important for public health, as higher color levels may correlate with issues that could affect taste or the presence of harmful substances. Reducing color in water supply not only addresses aesthetic concerns but also helps maintain the overall quality and safety of drinking water.