septage

But this can be a costly two- or three-hour drive, says Mark Hassman, project manager for the Mobile Septage Treatment System at Crane Engineering in Wisconsin.

In the United States, there are government standards for licensed septage processing facilities, public and private.

Lime is used to cut the acid content, and aerobic and anaerobic bacteria digest the septage further.

The target is the sludge at the bottom called septage, mostly human waste that the useful bacteria in the septic tank have not been able to digest.

Or septage may be processed separately in a dedicated facility, undergoing several stages of treatment.