366 



will be properly taken care of without objectionable odors. Such a stream 

 however should have a flow of about 300 cubic feet per minute for each 

 1.000 inhabitants. Instances where disposal by dilution alone is sufficient 

 are not many and usually some additional treatment is necessary, suitable 

 to local conditions. 



If the stream into which the sewage is to be discharged allows of par- 

 tial dilution, treatment by some properly designed form of tank may be 



F 



SW$e blowoff pipe 

 Valve 



77 



Septic Tank 



Tank 



7^ 



Manhole 



To sob soil tile 



Chaa Brossmann 

 Indianapolis 



Section 



Fig. 1. 



Type of Septic Tank Suitable for Ordinary Dwelling. 



sufficient, but tank treatment alone will not always suffice. Tank treat- 

 ment is but a step in the purification of sewage and should usually be fol- 

 lowed by some form of filtration or after treatment. Various forms of 

 tanks can be used but tbe type and size that insures the best results can 

 only be determined after proper investigation of all conditions — as the 

 number of people, amount of sewage, the rate and the time of flow, tbe 



