PARK SANITATION 



847 



tank the effluent is gradually discharged through an overflow pipe into a 

 subsurface irrigation system, onto a filter, or into a stream. 



The liquefying tank should have a capacity of at least forty gallons 

 (6 to 7 cubic feet) of water when the water just reaches the level where it 

 begins to trickle into the effluent pipe. Such a privy is large enough for 

 three persons and the capacity of the tank must be increased by ten to 

 twelve gallons for each additional person. The effluent tank may be some- 

 what smaller, but should be of sufficient size to receive and store a fair 

 amount of the fluid from the liquefying tank. The modification of the 

 L.R.S. privy, known as the Kentucky Sanitary Privy, is shown in Plate 323. 

 This type has one tank divided into three compartments by baffles. While 

 concrete liquefying and effluent tanks are desirable, a very satisfactory 

 L. R. S. privy can be built with the tanks made of iron barrels or drums 

 as shown in Plates 324 and 325. In this type of privy the effluent tank when 

 full can be hauled away and emptied. If necessary, the effluent can be dis- 

 infected prior to disposal by the addition of one to two ounces of calcium 

 hypochlorite in solution to each 

 fifty gallons of effluent. 



As the septic action causes 

 a reduction in the volume of the 

 excreta additional water must be 

 placed in the liquefying tank at 

 weekly intervals. The amount 

 added will vary according to the 

 rate of evaporation, but usually 

 about five per cent of the capac- 

 ity of the tank will be sufficient. 

 Thus, about two and one-half 

 gallons should be added to a 

 fifty-gallon tank once each week. 

 The liquid in both tanks should 

 be kept covered with a film of 

 crude oil or kerosene. The privy 

 box for a L. R. S. privy is the 

 same as that described for a sani- 

 tary privy except that the 

 excreta is received into the lique- 

 fying tank instead of a removable 

 pail. The box should be provided PLATE No - 3 2 3- L. R. s. SANITARY PRIVY 



. . . (The Kentucky sanitary privy, Kentucky State Board of 



With Screened Vent holes and Health, 1913.) One type of urinal is shown. The front com- 



n j ^-11 partment is the effluent tank and liquefaction takes place in 



Vent Hue, and automatically the middle and rear compartments. 



