Rusrby (Higrh Level). 



of sampling, 1 to 30. (Part I.)] The water of 

 this river was on the whole in fair condition 

 chemically at the time of our observations, but in 

 summer the large amount of oxidisable matter in 

 one of the samples drawn above the effluent outfall 

 showed that there was at the time some polluting 

 liquid — not from the high-level farm — entering the 

 river. The volume of river water to effluent is again 

 rather large here. There was no sign of any 

 nuisance from the farm. When the effluents were 

 analysed the dissolved oxygen in the five summer 

 samples from chemically precipitated sewage was 

 practically nil. In No. 106, on the other hand (the 

 summer sample of effluent from sewage not chemi- 

 cally treated), the dissolved oxygen was very high, 

 although there was no reserve of nitrate. (These 

 oxygens were boiled out.) In the spring samples 

 the dissolved oxygen was only moderate in amount 

 (from 1 to 4 c.c), but it did not appear to be taken 

 up at all rapidly between the time of drawing and 

 the time of analysis — a very good sign. (These 

 effluents being more or less coloured, however, would 

 tend to make the readings of the copper chloride 

 tubes too low.) Speaking generally, so far as 

 non-putrescibility was concerned, no fault could 

 be found with the river water, and, moreover, 

 the samples maintained their aeration well upon 

 incubation. 



" The sewage (mainly domestic) 

 Conoluslons. is distinctly strong, although not 

 quite so strong as the sewage at 

 Aldershot Camp and Nottingham. For a combined 

 surface irrigation and filtration farm Rugby was 

 treating a large volume of sewage, more especially 

 per acre of the ' working ' daily irrigable area, but 

 also per acre of the total irrigable area. The sewage 

 being strong, the farm was therefore treating in the 

 aggregate a large quantity of organic matter — namely, 

 about one-half the total amount which Cambridge 

 treats. The soil and subsoil (heavy loam overlying 

 stifE clay with ' gravel ' pockets) is certainly not of 

 an ideal kind for purifying a large volume of sewage. 

 It is advisable, however, to call attention here to 

 the method of treatment followed at Rugby — namely, 

 the mixing of one volume of effluent from a larger 

 plot of ground with an equal volume of sewage, and 

 the passing of that mixture over a second smaller 

 plot. The sewerage system is partially separate, 

 but a large proportion of the storm water is treated 

 on the farm. We consider that 42,800 gallons per 

 acre per twenty-four hours (8,500 gallons per acre 

 of the total irrigable area per twenty -four hours) is 

 too large a volume of a strong sewage to be treated 

 by screening, settling and surface irrigation (with 

 some filtration) on soil of the above nature." 

 (Part I., page 95.) 



Nuisance 

 and Diffloulties. 



In hot, close weather consider- 

 able nuisance arises from the 

 cleaning out of the tanks and 

 also from the carriers. The latter is caused by 

 matter derived from the sewage being held back 

 by the inequalities in the carriers and putrefying. 

 The chief difficulties in working the farm are 

 the want of land for moving the sewage, as the 

 wheat and oats cannot be sewaged and occupy 

 valuable space. 



LATER WORK. 



The area available for sewage disposal has been 

 diminished by extensive excavations for the adjoin- 

 ing cement works and also by the formation of a 

 very large spoil bank. The land was only hired by 

 the corporation, and had therefore to be surrendered 

 — it is unfortunate that the best part was thus 

 taken. A scheme has been prepared for dealing 

 with the increased flow of sewage, but as it has not 

 yet come before the Local Government Board no 

 details can be published. 



53 



