Land Treatment of Sewagfe. 



It should be noted that the 

 sewage was screened and settled. 

 Allowances must be made for 

 evaporation in comparing the efflu- 

 ent with the sewage. The chief Ohemical results 

 are : — 



Analyses- 

 Sewage, Effluent 

 and Stream. 



which must sometimes impose a considerable strain 

 upon such heavy land." (Part II., page 135.) " The 

 Anstey Brook may therefore be regarded as having 

 been, from a chemical point of view, in a fairly 

 satisfactory condition (for a non - drinking - water 

 stream) at the time of Mr. Kershaw's visits to 



CHEMICAL ANALYSES (PARTS PER 100,000 BY WEIGHT). 



Sewags.* 



Effluent. 

 (8-13 sampleB.) 



Stream. 

 (1 Bample.) 



Total nitrogen ... 

 Ammoniacal nitrogen . 

 Total organic nitrogen. 



Albuminoid nitrogen . 



Oxygen absorbed 4 hours at 80 deg. Fahr 



and in subsoil 



Nitric and nitrous nitrogen ... 



Chlorine (in water supply l"! 



water 1-96) 



Incubator test as judged by smell 



Solids in suspension (hourly samples only)... 



6-53 

 6-53 

 1-93 



1-14 

 1616 



10-08 



341 



2-53 

 1-65 

 0-45 



0-20 



2-50 

 0-51 



10-79 (?) 



83-2 per cenf^ 



purification > 



(average) J 



82-8 per cenf^ 



purification f 



(average) J 



92 per cent 



passed 

 (13 samples) 



0-31 

 0-055 



0-00 



0-47 

 0-18 



2-30 

 Not noted. 

 Sure to be 

 right 



* Approximate averages of three sets of samples dravm in equal quantities per hour for twenty-four hours and of five chance samples. 



" The effluents were either clear, slightly opalescent, 

 or in one or two cases more or less turbid. Their 

 colour was brown or sometimes yellow, and there 

 was always some flocculent matter present, for the 

 most part, no doubt, fragments of weed from the 

 drains, tinged with oxide of iron. Every sample 

 was alkaline, some of them strongly so. When they 

 came to be analysed the smell was quite clean — i.e., 

 usually earthy, though sometimes inclining to a 

 seaweed or fishy odour. In a few samples tested 

 there was much lime and sulphate in solution." 

 (Part II., page 133.) 



" The effluents obtained, while not of a high class, 

 are better as regards keeping property than the 

 figures of analysis would lead one to expect. Taking 

 them all over they may be described as moderate. 

 The sewage is no doubt a somewhat difficult one 

 to treat, and the nitrifying area afforded by such a 

 stiff soil and subsoil is necessarily small (relatively). 

 As the slope of the farm, speaking generally, is all 

 that could be wished for allowing the sewage to be 

 treated over a number of plots of ground successively, 

 the conditions in this respect are favourable. But, 

 on the other hand, one must not forget that storm 

 water up to twice the dry-weather flow is treated, 



Leicester, if we take the relatively small dilution 

 of effluent by brook water into account." (Part II., 

 page 139.) 



The Bacteriological figures may be summarised as 

 on following page. 



" Considered from the bacteriological point of view, 

 none of the effluents were in a fit state to be turned 

 into a drinking-water stream. The majority were 

 even hardly in a proper condition to be discharged 

 into non-drinking-water rivers. Nevertheless, the 

 fact that some of the effluents were sufficiently pure 

 to be discharged into a non-drinking-water stream, 

 and that a fair number of them, although exception 

 might be taken to them, came within measurable dis- 

 tance of satisfying reasonable standards, encourages 

 the belief that by acquiring an increased area of land 

 the effluents from Leicester sewage farm might be 

 made uniformly fairly good. Whether acquiring a 

 further area of land is practicable or advisable is a 

 separate question, and need not be discussed here. 

 The only contention is that the results were not so 

 uniformly and unmistakably unsatisfactory as to 

 point to the impossibility of obtaining continuously 

 good results with land of the kind available at 

 Leicester." (Part III., page 93.) 



38 



