IQQ EXPERIMEXTAL FARMS 



4-5 EDWARD Vll., A. 1905 



Figure I. represents a tank fitted with the automatic discharge valve. The size 

 of the tank for the ordinary farm house may be 6 feet long by 3 feet wide by 3 feet 

 deep, or a working capacity, say, of 120 gallons to each compartment. Since it is appar- 

 ently desirable that the sewage should be submitted to the action of the bacteria for 

 a period of 24 to 36 hours before passing into the second compartment of the tank, 

 it is perhaps better to have the tank a little too large than too small. It is customary 

 to allow a capacity of 12 gallons for each person. It will be seen that by a partition 

 wall, carried within two inches of the top or roof, the tank is divided into two smaller 

 tanks ar compartments, figured as No. 1 and 2. Into the first of these, near the top, 

 the sewage from the house flows through the glazed tile E. connected with the soil 

 pipe which opens above the roof. The pipes from closet, bath, sink, &.C., should, of 

 course, be trapped before entering the soil pipe. 



In this tank or compartment (No. 1) there should be a perforated partition, as 

 shown in cut, to prevent paper and other solids entering the overflow and being car- 

 ried over into compartment No. 2. It is in No. 1 compartment that the bacteria 

 chiefly effect their work of decomposing the organic matter of the sewage, and vv'hen 

 in time this compartment becomes full its fluid contents pass over into No. 2 by means 

 of the overflow F. If there is no perforated partition in No. 1 the lower orifice of this 

 overflow (F) is covered with wire netting which may act as a strainer to pTevent any 

 paper. &c., passing into No. 2. In compartment No. 2 is the automatic valve H., con- 

 nected with the discharge pipe D,. which carries off the effluent to the subsurface tiles 

 (see figure 2). The success of the system depends largely upon this valve, for it is 

 essential that compartment No. 2 should be emptied as soon as it is full, and then 

 allowed to refill. This can only be satisfactorily accomplished by a self-acting (both 

 opening and closing) valve.* This second chamber should have a 4-inch vent pipe, 

 to allow the entrance of air. Manholes are provided at G, to permit of the examination 

 of the tank at any time. The probabilities are, however, that no cleaning out will 

 be necessary for years, as the action of the bacteria is very thorough and complete in 

 destroying the organic matter. 



The tank must be so situated that its glazed discharge pipe D, at the point from 

 which the field tiles are led off is not more than 12 inches helow the surface of the 

 ground. This pipe as well as the field tiles are to be laid on a level so that the latter 

 will be equally filled when the tank is discharged. If the ground be level, this will 

 necessitate constructing the tank so that a portion of it is above the surface of the 

 land, and in this case it should be baulked around, covered with earth and sodded. It 

 is not essential that the tank should be close to the house, but if placed at a distance 

 the inlet pipe should have a fall from the house and be protected from the frost. Un- 

 glazed field tiles inserted every two or three feet along the discharge pipe D. finally 

 distribute the effluent through the soil (Fig. 2). If desired, these distributing tiles 

 ' from D need not commence in the immediate vicinity of the tank, but it is important 

 that they should not be at a greater depth than 12 inches, unless the soil is very light 

 and sandy and has good natural drainage. Since a 4-inch tile holds -i gallon and it is 

 essential that there should be tile capacity for all the effluent immediately on discharge, 

 a tank with a compartment No. 2 of 100 gallons will require at least 200 distributing 

 tiles. If the soil is heavy clay, it should be uiiderdrained. Wlien the soil is of such 

 a character that percolation is very difficult, the distributing tiles may be replaced by 

 a ' filter box ' of sufficient size, filled with sand or gravel, or coke, the effluent entering 

 near the top at one end and being conducted away from the other end by subdrain.s. 

 However, in practice it is found that a larger tank with less frequent discharge and 

 more tiles is preferable to a filter box. 



I 



*An automatic discharge valve is made by the Dominion Valve Co., Toronto. The price 

 Is from $18 to $25, according to size and quality. 



I 



