NOTES ON OTHER FARMS VISITED. 



Engineering Notes. — Cities and 

 Luton. towns such as Winchester and 



Luton, whose sewage farms are on 

 the chalk, find themselves in the fortunate position 

 of being untroubled by effluents, for the sewage at 

 these places sinks into the ground and disappears. 

 For this reason attention may be drawn for a moment 

 to the effluents obtained artificially by the filtration 

 of the Luton sewage through different thicknesses 

 of chalk in situ, viith previous removal of the surface 

 soil. The results of the chemical analyses showed 

 that the sewage underwent comparatively little 

 direct purification in its rapid passage through 3 ft. 

 of chalk. This emphasises the necessity for the 

 careful examination of all well and spring waters 

 which could by any possibility come within the 

 sphere of influence of a chalk sewage farm. Ohemi- 

 eal Notes. — The partially settled sewage was mode- 

 rately strong as regards nitrogenous matter, but the 

 " oxygen absorbed " figures were rather low. The 

 effluent was obtained after the removal of the 

 surface soil and appeared in one and a half minutes. 

 It contained phenomenal amounts of nitrate — one 

 sample taken during heavy rain yielded twenty-four 

 parts of nitric nitrogen per 100,000. The top soil 

 was rather rich in nitrate, there was less in the 

 chalk and it diminished with increased depth. 

 Bacteriological Note. — All the effluents gave very bad 

 results, and were not bacteriologically remote from 

 samples of untreated sewage. 



Engineering Notes. — The Worsley 

 Worsleyi farm effluents from that portion 

 of the farm which consisted of 

 pure peat land were, as might have been expected, 

 far from satisfactory, though even here there was a 

 very considerable degree of purification. Without 

 at all recommending peat land for the treatment of 

 sewage, it is interesting in this connection to recall 

 a laboratory experiment made by the Rivers Pollu- 

 tion Commission (First Report, Vol. I., page 69), as 

 follows : " These analytical results show that, 

 although the action of the Lancashire peat upon 

 sewage is for a couple of months bat slight and 



unsatisfactory, yet the subsequent steady improve- 

 ment of the effluent water encourages the hope that 

 this material would, after a somewhat longer educa- 

 tion, become an efficient purifier of sewage filtered 

 through it at the rate of 49 gallons per cubic yard 

 per twenty-four hours." Ghemical Notes. — The 

 nitrogenous matter was moderate and the " oxygen 

 absorbed " relatively high. All four effluents from 

 the peat land were bad, or nearly so. Peat is unsuit- 

 able, as it acts like a sponge ; there is the difficulty 

 of draining it and the consequent lack of aeration. 

 Bacteriological Note. — The results, considered in 

 relation to the peaty characters of the soil on the 

 farm, are surprisingly good and do not, from the 

 bacteriological point of view, altogether support the 

 opinion so generally held that peat is quite unsuit- 

 able for sewage purification purposes. 



Engineering Notes. — See Derby 

 Hemsworth. County Asylum. Ghemical Notes. 

 — The crude sewage was distinctly 

 strong and the settled sewage fairly so. The two 

 samples of effluent were very bad. Bacteriological 

 Note. — The effluents were unsatisfactory, though one 

 passed the B. coli test. 



Derby 



County Asylum 



(Mickleover). 



Engineering Notes. — The Mickle- 

 over and Hemsworth farms afford 

 instances of sewage treatment on 

 very shallow surface soils overlying 

 stiff clay — i.e., on types of soil not well adapted for 

 the treatment of sewage. But even under such 

 unfavourable conditions the Mickleover effluents 

 furnish an illustration of the point emphasised else- 

 where in this report — viz., that (the question of) 

 purification by a soil is one of degree rather than 

 one of intrinsic ability or disability. Chemical Notes. 

 — The sewage was not particularly strong so far as 

 nitrogenous matter was concerned, but the " oxygen 

 absorbed " was excessively high in proportion. 

 Speaking generally, the effluents were better chemi- 

 cally than they looked, but the system is faulty and 

 solids in suspension should be eliminated by running 



66 



