What color is typical for septic wastewater?

Septic wastewater is typically characterized by a dark gray or black coloration due to the presence of decomposed organic matter, bacteria, and other contaminants found in domestic sewage. This color is a result of the breakdown of waste materials by anaerobic bacteria in the septic tank, leading to a mixture that is dense and often has a dark, murky appearance.

The specific color can vary somewhat depending on the types of waste introduced into the septic system, but in general, dark gray or black is prevalent as it indicates a high level of solids and organic compounds. The appearance of septic wastewater differs significantly from the bright or pale colors of other liquids, which can indicate the presence of other substances that are not typical in normal septic conditions. Thus, dark gray or black is a reliable indicator of the nature of septic wastewater.