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CALIFORNIA GARDEN FLOWERS. 



similar material placed over each joint so as to prevent the dirt from 

 sinking in and blocking the drain. The soils will then absorb all the 

 liquid sewage without injury to soil or sanitation. 



Construction of the Septic Tank. 



Bacterial Action. It is the action of bacteria that transforms the 

 sewage in a septic system, and these are especially active in two places, 

 first in tank No. 1, and secondly when the sewage reaches the soil 

 between the joints of the drain tile. 



The first lot of bacteria can work properly only without air, or 

 with very little. Thus the tanks must be always tightly closed on 

 top. The bacteria in this tank reduces all solids to a liquid condition. 



The bacteria of the drain can work properly only with lots of air, 

 and California soils, being naturally so dry, open and well aerated, 

 arc ideal for this purpose. The second tank is needed to give the 

 bacteria in the soils plenty of air. If the sewage should flow as it 

 came from the house it would keep the joints of the drain all uniformly 

 wet and it would drown out the bacteria except a few on the surface. 

 As a septic tank discharges only about once a day the sewage has a 

 chance to dry out in the soil, the bacteria gets plenty of air, and has 

 plenty of time to work. 



The sewage when the bacteria get through with it is, as previously 

 stated, perfectly harmless. It also does not injure the soil, and as it 

 contains considerable fertilizing material it is excellent for plant 

 growth. It is entirely satisfactory to have the drain run through 

 vegetable garden, alfalfa or orchard, provided plowing is done so as 

 not to disturb the tile. If, however, there are trees or berry vines 

 whose roots can get to the tile, it is very advisable to have the farther 

 end of the drain open so as to allow a free circulation of air to prevent 

 bunches of roots from forming and blocking up the drain. 



The foregoing describes a complete system for disposition of 

 sewage automatically and restricts the use of the water to subirriga- 

 tion. It is also feasible to use the outflow for surface irrigation by 

 means of newly made furrows which, in small operations, can be 

 made with a hoe alongside the lines of plants which it is desired to 

 irrigate. ,The outflow from tanks in proper operation is completely 

 harmless, but has a disagreeable odor. For this reason it is not 

 desirable to allow it to flow over the surface, but rather to allow 

 it to run for a short time in a furrow in which it is covered with dry 

 earth and allow to complete in the porous soil the same transformation 



