Septic tank
While a properly maintained and located septic tank does not pose any more environmental problems than centralized municipal sewage treatment, certain problems can arise with septic tanks in unsuitable locations. Since septic systems require large drainfields, they are not suitable for densely built areas.
Fecal sludge management
Septage waste is periodically removed (with a frequency depending on tank capacity, system efficiency, and usage level, but typically less often than annually) from the septic tanks by specialized vehicles known as vacuum truck. They pump the septage out of the tank, and transport it to a local sewage treatment plant. It could also be used by farmers for fertilizer, or stored in large septage waste storage facilities for later treatment or use on crops.