Land Treatment of Sewag^e. 



yellowish to brownish tint, with but a very small 

 amount of suspended solid of one kind or another ; 

 while in others the liquid was turbid, with very con- 

 siderable quantities of suspended solids. Three- 

 fourths of them may, however, be taken as very free 

 from matter in suspension. Nos. 39a and 44, for 

 instance, belong to the category of turbid samples ; 

 they were drawn during rain — i.e., contained much 

 storm, water. No. 380, also turbid, showed no pre- 

 cipitated sediment, but a large quantity came down 

 in the centrifuge. This last sample was not drawn 

 during rain, but was insufficiently purified. Those 

 few notes with regard to the appearance of the 

 Beddington final and general effluents are, I think, 

 sufficient in themselves to indicate the difficulty 

 of treating largely fluctuating volumes of liquid 

 (sewage plus storm water) by surface irrigation. 

 Three-fourths of the effluents had a good clean smell 

 when they came to be analysed, but No. 153 (a bad 

 sample) had a faint sewage (?) smell. No. 380 (also 

 bad) a fishy smell, and Nos. 39 and 44 (fair) a fishy- 

 earthy smell. AH that were tried for reaction were 



with onr present data it is impossible to say how 

 much of the purification eilected at Beddington is 

 due to filtration through the top soil and how much 

 to surface irrigation pure and simple. The sewage 

 is practically a domestic one of moderate strength, 

 probably of about average strength. The volume 

 of sewage treated per acre, exclusive of storm 

 water, was very large for a (mainly) surface irriga- 

 tion farm . . . The analytical results of the final 

 and general effluents show that the Beddington 

 farm, used for surface irrigation under the condi- 

 tions detailed in the engineering report, is capable 

 of producing a high-class effluent, chemically speak- 

 ing, and does so sometimes but not always. Hence 

 one must infer that the land was rather overdosed 

 with sewage at the time the observations were made. 

 The irregularity caused by the intermittent flushes 

 of storm-water sewage in varying quantity no doubt 

 adds much to the difficulty of treatment." (Part II., 

 page 102.) 



The Bacteriological figures may be summarised as 

 follows : — 



BACTERIOLOGICAL ANALYSES (TOTAL NUMBER OF BACTERIA PER C.C). 



Sewage. 

 (6 samples.) 



Effluent.* 

 (10 samples.) 



Stream. 

 (1 sample.) 



(1) Gelatine at 20 deg. C 



(2) Agar at 37 deg. C 



(3) B. coli or closely allied forms (say at 



least) 



(4) B. enteriditis sporogenes (spores —say 

 at least) 



29,000,000 

 5,315,000 



100,000 

 850 



1,413,200} ^5 P^'^^^j"*"'^''"-} 

 1 1 o ojft f 97 per cent reduc- \ 



(■ Varied from 10 ) 



3,241 ] not 100 to 10,000, f 



( not 100,000 ) 



23 



'Varied from none"- 



I in 1^0 c-C- to at / 



) least 100, but less ( 



than 1,000 ^ 



72,000 

 2,680 



10 not 100 

 None in 1 c.c. 



* Satisfactory (1) 3, (2) 6, (3) 6 and (4) 6 out of 10 effluents in each case. 



alkaline, and the three tested qualitatively showed 

 much lime and a good deal of sulphate in solu- 

 tion . . . The dissolved oxygen present when the 

 samples came to be analysed varied very much, but 

 half of the effluents were then well aerated — i.e., 

 contained from 4 c.c. upwards of dissolved oxygen 

 per litre — a point in their favour." (Part II., page 

 98.) " Since the surface soil at Beddington is about 

 15 in. deep, and is, moreover, of very good quality 

 for sewage purification, we are to some extent deal- 

 ing here with a shallow filtration farm . . . But 



" Considered from the bacteriological point of 

 view, none of the effluents were in a fit state to be 

 turned into a drinking-water stream . . . About 

 half the effluents were satisfactory [non-drinking- 

 water streams]. The average results were by no 

 means so unsatisfactory as to indicate the impractic- 

 ability of working land of the kind available at 

 Beddington, so as uniformly to yield a reasonably 

 good effluent. The fact that some of the effluents 

 yielded such good results leads to the belief that, deal- 

 ing with the same volume of sewage, the acquisition 



33 



