What is the difference between gray water portable tanks and black water portable tanks?

by Portable Tank Group Tech Team
(Florida, USA)

A student working on a school science project contacted our tech team in regard to the difference between gray water portable tanks and black water portable tanks.

Grey water and black water are different types of waste water.

A septic tank allows the pathogens in the black water to break down before releasing leach water. Most septic tanks need to be pumped periodically to remove solids.