Septic tank
A septic tank is an underground chamber made of concrete, fiberglass or plastic through which domestic wastewater (sewage) flows for basic treatment. Settling and anaerobic processes reduce solids and organics, but the treatment efficiency is only moderate (referred to as "primary treatment"). Septic tank systems are a type of simple onsite sewage facility (OSSF). They can be used in areas that are not connected to a sewerage system, such as rural areas. The treated liquid effluent is commonly disposed in a septic drain field which provides further treatment. However, groundwater pollution may occur and can be a problem.
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.