34. An efficient system of subsoil irrigation and drainage must consist of two parts: the tight cesspool, or tank, where the waste matters from the house are retained until they are decomposed, and the network of pipes which receives the sewage from the reservoir and distributes it into the ground.

Disposal Of Sewage 2

Fig. 2

The cesspool - of which Fig. 2 shows a section - should be built of hard brick laid in cement, about 6 feet in diameter and 5 feet deep from the mouth of the outlet b. In the Figure, a shows the sewer pipe conveying the sewage from the house; b is the outlet pipe connecting with the distributing pipes; c shows the liquid sewage; d is the 8-inch wall, e, the 4-inch bottom, f, the 4-inch dome, and g, the manhole, 18 or 20 inches in diameter. This manhole should be covered with an iron grating. The main drain should enter the cesspool just above the water line. The outlet pipe should have a quarter bend cemented in where it runs out of the cesspool, and should be laid at a very gentle pitch, with branches as indicated in Fig. 3. This pipe should be made of vitrified earthenware, laid with the hubs towards the upper end, and having a Y inserted alternately with the straight pipe, to connect with agricultural tile forming the branches.

In Fig. 3, a shows the cesspool, while b shows the location and position of the 4-inch outlet pipe; c is the sewer pipe from the house, and d-b, etc., the 2-inch agricultural drain pipe.

The tiles forming the lateral branches should be laid 1/2 inch apart, and a piece of paper should be put over the joint to keep the earth from sifting in and obstructing the flow. The end of the main line should not be crossed, but a 2-inch reducer should be put in, so that the line of lateral branches may be continued if necessary.

For any ordinary dwelling house, inhabited by a family of six to eight persons, 500 feet of lateral outlet is enough.

Care should be taken to grade the earth away from the building, and there should be a very decided pitch in every direction, in order to carry off the water.

Disposal Of Sewage 3

Fig. 8.