Which component is NOT part of an Approved Private Sewage Disposal System?

An Approved Private Sewage Disposal System typically includes components that effectively treat and manage wastewater in a localized setting. The subsurface seepage field, which allows effluent to be absorbed into the soil, is crucial for facilitating the natural filtration and treatment of sewage. Holding tanks are also recognized as part of a private sewage disposal system as they temporarily store sewage until it can be properly transported for treatment.

In contrast, a sewage treatment plant is a larger-scale facility designed to treat wastewater from multiple sources, such as municipal or community systems, rather than serving individual households or small clusters of homes. It involves complex processes and infrastructure that go beyond the scope of individual private sewage disposal systems, which are intended for smaller, localized applications. Thus, the inclusion of a sewage treatment plant does not align with the components typically classified under private sewage disposal systems.