Typically, portable restroom tanks are emptied with a vacuum attached to the porta potty tank via a hose, which sucks the waste into a storage unit mounted onto a truck. The unit is then filled with fresh water and a cleaning chemical solution, and sanitation workers spray down the entirety of the interior to rid it of any bacteria. Then they restock hygienic necessities like toilet paper, and the porta potty is ready for use again, good as new.