What is a holding tank sewage system?

A holding tank sewage system is designed specifically to temporarily store sewage until it can be transported for disposal or treatment. This type of system is characterized by having a holding tank that collects wastewater without any discharge outlet for effluent. The sewage is held until appropriate measures can be taken for its disposal, such as pumping it out and transferring the contents to a treatment facility. This system is particularly useful in areas where traditional septic systems may not be suitable or where there are restrictions on direct discharge due to environmental regulations.

The other options depict systems that either involve treatment or discharge processes that do not align with the primary function of holding tanks. A. refers to systems designed to discharge effluent directly, while C. mentions systems that treat sewage without any storage, and D. focuses only on gray water, which does not encompass the broader definition of a holding tank sewage system.