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.
Septic tank
The rate of accumulation of sludge—also called septage or fecal sludge—is faster than the rate of decomposition. Therefore, the accumulated fecal sludge must be periodically removed which is commonly done with a vacuum truck.