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.
FEMA trailer
The typical FEMA trailer has two propane tanks on the front of the trailer behind the master bedroom, which provide the hot water, indoor heating, and gas for the stove and oven. Running water for the trailer is usually provided by some sort of water source on the property, usually through a garden hose. Sewage is piped directly to an underground sewage main on the property. Most trailers have several windows which can be opened, as well as small light fixtures in each room.