It is often desired to install a system of plumbing in a building in the country or in a village where there is no system of sewerage with which to connect. In this case it becomes necessary to construct a cesspool. This is always undesirable, but if properly constructed and placed at a suitable distance from the house and in such a position that it cannot drain into a well or other source of water supply it may be used with comparative safety. Especial care should be taken in the construction, and when in use it should be regularly cleaned. One form of cesspool is shown in Fig. 63. This consists of two brick chambers located at some distance from the building and in a position where the ground slopes away from it if possible. The larger chamber has a clean-out opening in the top which should be provided with an air-tight cover. An ordinary cast iron cover may be made sufficiently tight by covering it over with 3 or 4 inches of earth packed solidly in place. A vent pipe should be carried from the top to such a height that all gases will be discharged at an elevation sufficient to prevent any harm.

The smaller chamber is connected with the first by means of a soil pipe as shown. This chamber is arranged for absorbing the liquids and for this purpose is provided with lengths of porous tile radiating from the bottom as shown in the plan. The house drain connects with the larger chamber, which fills to the level of the overflow, then the liquid portion of the sewage drains over into chamber No. 2 and is absorbed through the porous tile branches. The solid part remains in chamber No. 1, and can be removed from time to time. A suitable trap should of course be placed in the house drain in the same manner as though connected with a street sewer. The safety of the cesspool will depend much upon its location, its general construction and care and the nature of the soil.