EUEAL ENGINEEEING. 785 



of suspended matter and similar figures for dissolved oxygen taken up from 

 water in fiive days at 80° F. is desirable. 



He prefers the use of a precipitant as a preliminary treatment rather than a 

 septic tank. The best filter is considered to be the deep percolating filter. 



" Distribution should be good in order to obtain the best results. In many dis- 

 tricts peat is obtainable, and may be used as a distributer for certain types 

 of filter. It requires, however, frequent attention and renewal if satisfactory 

 results are looked for. The used peat possesses good manurial properties. 



" With regard to the treatment of dairy wastes upon land, it is desirable that 

 there be some form of preliminary treatment before the liquid is treated on 

 the laud, in order to remove solids which would otherwise tend to choke the 

 pores of the soil. . . . Concerning the rate of treatment of dairy wastes upon 

 land, much will depend uiwn the quality of the soil and subsoil, but with land 

 of medium quality from 3,000 to 4,000 gal. per acre per twenty-four hours of 

 settled or strained liquid is probably a safe dose. ]\Iuch, however, depends 

 upon the nature of the intermittency of the irrigation. Grass land is especially 

 benefited by the careful application of dairy wastes." 



Report sumraax'izing the work of the public commission for the testing of 

 processes for the purification of sewage from sugar refineries from 1S99 to 

 1913, C. GtJNTHEB and A. Hekzfeld {Mitt. K. Landesanst. Wasserhyg. Berlin- 

 Dahleni, No. 18 {191 Jf), pp. 1-32). — It is concluded from the results of this work 

 that there are numerous points in the process of purification of sewage from 

 sugar refineries which need further systematic investigation. The work so far 

 has shown that there is no single process which may be considered adaptable 

 to all cases. Surface irrigation, while successful in many cases, is generally 

 unsuccessful owing to the land area required. The combination of land irri- 

 gation and lime treatment processes is generally unsuccessful for the same 

 reason and on account of the bad effect on the physical condition of the soil. 

 Since no imiversal process is available it is considered necessary to base the 

 selection of the process to be used entirely on local conditions. 



The operation of sewage disposal plants, F. E. Daniels {Neto York: 

 Municipal Journal, 1914, PP- [YIII'i+lSG, figs. J^O). — ^This book presents a 

 series of articles on the practical management and operation of sewage disposal 

 plants, the main purpose being " to assist the plant attendant by pointing out to 

 him many things he should do and some he should leave undone, in order that 

 he may be .able to keep his plant up to its highest state of efficiency at a mini- 

 mum expenditure of cost and energy. Likewise it has been endeavored to 

 show that poor designs are troublesome, costly, and inefficient." 



The following chapters are included : Grit chambers and screens, tanks, filters, 

 disinfection, chemical precipitation and electrolytic treatment, trade wastes, 

 testing stations, making tests, and records of plant operation. 



It is stated that a much larger area is required for the treatment of sewage 

 by sewage farming than is required for the process of intermittent sand 

 filtration. " Usually only about 10,000 gal. per acre per day can be success- 

 fully treated upon a broad irrigation area, while ten times that amount can 

 be taken care of upon a good sand bed. Unless carefully managed, the process 

 is likely to be objectionable if near built-up communities on account of odors, 

 flies, and unsiglitliness. ... In some localities good crops have been raised, 

 notably in California, but take it all in all, sewage farming is not a paying 

 operation. . . . 



"A low or marshy area should never be selected to receive sewage, because 

 under such conditions there is danger of a nuisance without a purification of 

 the sewage. Light, sandy or loamy soils with free drainage are the most suit- 

 able, while stiff clay is almost worthless. . . . The attendant must know just 



