PRELIMINARY. 



In the first place I propose to deal seriatim with 

 the eight sewage farms — Aldershot Camp, Altrin- 

 cham, Cambridge, Croydon (Beddington), Leices- 

 ter, Nottingham, Rugby (High Level), and South 

 Norwood — that were under detailed investigation 

 by the officers of the commission. Where possible 

 an account of each farm up to 1900 to 1901 will 

 be given, and this will be followed by a review of 

 the information contained in the blue-books. The 

 chief points will be taken in order: (1) The com- 

 position of the sewage and the preparation thereof 

 before passing on to the land; (2) the nature of 

 the soil and subsoil; (3) figures relating to acre- 

 age, population, &c. ; (4) method of treatment of 

 sewage and cropping of land ; and (5) analysis — i.e., 

 quality of effluent as compared with sewage and 

 with stream. It is not my intention to refer to 

 the financial side of the question; firstly, because 

 most of the farms were in operation before the 

 introduction of bacterial methods as such for the 

 purification of sewage, and therefore land treat- 

 ment was practically inevitable; and, secondly, on 

 account of the great diversity which exists with 

 regard to the many points that would have to be 

 considered, and of which no comparison is really 

 possible. The works that have been constructed 

 since 1900 to 1901 will be noticed, and the 

 schemes that are now in hand will receive atten- 

 tion. Particulars of the eight farms are briefly 

 summarised in a table immediately following the 

 last detailed description. The experiments at 

 Croydon, Leicester and South Norwood, and the 

 treatment of " new land " at Aldershot Camp are 

 referred to. Details (which I have tabulated) re- 

 specting other places visited will be found, and 

 also notes from the various reports thereon. 



Further, some remarks with regard to Andover 

 (Dr. Poore's system), buried sludge (Cambridge), 



value of efiluent, storm water, artificial storm 

 waters, surface street washings, and subsoil water 

 are included. 



A word or two of explanation is necessary with 

 regard to the points selected and the tables copied 

 or prepared. The state of the sewage on arrival 

 at the outfall depends largely on the many factors 

 hereafter detailed, and in considering the degree 

 of purification effected, the composition of the 

 sewage, the whole design of the sewerage system, 

 and the nature of the preliminary treatment, must 

 be carefully borne in mind. The soil and subsoil 

 tables are reduced from those given in the blue-book. 

 In acreage, population, &c., it should be under- 

 stood that the number of persons and the volume 

 dealt with per irrigable acre are stated for pur- 

 poses of comparison only. The analytical tables 

 give the more important figures for the sewage 

 effluent and stream together — this should facili- 

 tate comparison. " As far as possible, different 

 times of year were chosen for the visits to each of 

 the farms selected for observation, with a view 

 to (1) ascertaining, if possible, to what degree the 

 effluents were affected by seasonal variations in 

 temperature, rainfall, &c., and (2) obtaining a fair 

 idea of the working of the farm throughout the 

 year. It is perhaps hardly necessary to add that 

 a considerable element of uncertainty existed as 

 to the prospective meteorological conditions. On 

 more than one occasion a spell of cold weather 

 occurring in the warmer months of the year, and 

 conversely a period of warm weather during the 

 cold season, upset our anticipations to a consider- 

 able extent." (Part I., page 37.) That the influ- 

 ence of the air temperature on the temperature of 

 the effluent resulting from surface irrigation is very 

 marked is shown by the figures of air, sewage and 

 effluent temperature in the case of Croydon and 

 South Norwood; the temperature of the effluents 



