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1950-51 Theatre Catalog, 9th Edition, Page 192 (172)

1950-51 Theatre Catalog, 9th Edition
1950-51 Theatre Catalog
1950-51 Theatre Catalog, 9th Edition, Page 192
Page 192

1950-51 Theatre Catalog, 9th Edition, Page 192

FIGURE 5 Plan and drawings of a distribution box not considered necessary to a well designed iob.

Fill'er Bed

After the proper capacity for the septic tank has been determined, the next step is the design of the filter bed (see Fig. 6), and the dimensions shown in Table 111 may be used as a guide for this purpose.

The effluent from the septic tank is conveyed to the filter bed by means of 6" cast iron sewer pipe (see Fig. 7) with all joints leaded and completely water and gas tight. The glazed tile in the tilter bed is laid with open joints to permit the liquid to trickle out in small quantities at each joint. It then seeps through the sand hlter (see Fig. 8) and is picked up by the underdrains to be conveyed into the lateral drains, from which it is dissipated into the earth. These lateral drains are usually of

porous clay tile and are frequently called French drains or agricultural tile. These tiles may be laid with butt joints left slightly open and wrapped with burlap to keep dirt and other extraneous matter from entering and hampering the flow of water.

The number of feet of lateral drains required in any particular theatre is determined by the capacity of the septic tank, the size of the iilter bed, and the texture of the subsoil. However, the total estimated lengths of these agricultural tile laterals will run approximately as shown in Table IV.

Incidentally, while the septic tank itself should be located close to the fixtures it is to service, the filter bed should be situated outside of the ramp area to prevent crushing of the clay tile.

FIGURE 6 Plan of a sub-surface filler bed.

Table IV: Size of Lal'eral Drains Sandy Medium Clay

Car Soil Soil Soil Capacity Lin. Ft. Lin. Ft. Lin. Ft. 500 600 800 1,500 600 665 920 1,650 700 725 1,025 1,800 800 787 1,080 1,950 900 850 1,150 2,100 1,000 912 1,225 2,250 1,200 975 1,300 2,400 Dry Well

A dry Well (see Fig. 9) is a covered pit with open-jointed lining through which drainage from roofs, floors, or other areaways may seep or leach into a surrounding porous soil. Particularly recommended for use in drive-ins where the soil is of a very sandy nature, the dry well is intended to eliminate nonsewage wastes from the septic tank and subsurface drainage system. It should never be used for the disposal of septic tank efiiuent on sites where a well is used for water supply.

Dry wells should be located at least 50' from any source of water supply, 20' from any disposal field, cesspool, or seepage pit, and at least 10' from building foundation.

Two types of dry wells may be considered: Small pits serving individual drains, and large pits receiving roof drainage from an entire building. Where a single pit is provided to serve a floor or areaway drain, it may be constructed by using a 3' length of 15" or 18"

1950-51 Theatre Catalog, 9th Edition, Page 192