Practical sanitation : a handbook for sanitary inspectors and others interested in sanitation / by George Reid ; with an appendix on sanitary law / by by Herbert Manley.

  • Reid, George, 1854-1925.
Date:
1897
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    now recommended, leaving the consideration of the structural details to another Chapter. The present systems of sewage removal may be considered under two heads—viz., the water-carriage system and the Conservancy System. In the former, solid foecal matter is introduced into the sewers, while in the latter it is excluded. Great difference of opinion has hitherto prevailed as to which ought to have the preference, but the water-carriage system is now pretty generally admitted to be the better one, except, perhaps, in the case of scattered populations dependent for their water-supply upon local wells. The arguments in favour of the water-carriage system seem unanswerable. If it were possible to get rid of the ordinary slop water by some other means than sewers, then it might become a matter for consideration whether the necessity for the removal of excreta alone would warrant their introduction, but, as sewers must exist for ordinary waste-water purposes, the only point to determine is whether the addition of excreta is expedient or not. Now, so far as the composition of the sewage of water-closet towns is concerned, as compared with that of towns in which the dry method is in operation, the difference, as already pointed out, is very little, but the volume in the one case as compared •with the other is considerably greater. Six gallons per head per day increase of volume in the case of water-closet towns (Parkes) makes a considerable difference in the sum total of sewage that has to be disposed of; and in the case of inland towns, particularly where the absence of sufficient fall necessi- tates the pumping of every gallon, for the purpose of land or other treatment, before it is discharged into a stream, such an addition may become a matter for serious consideration. Then, again, it may be that the water-supply is limited, and cannot be supplemented without considerable expenditure, in which case the saving of 6 gallons per head per day must not be overlooked.* To obviate these objections, various plans for utilising the ordinary house waste-water as a flush for water-closets have recently been devised, and some town authorities are hoping to be able to overcome the difficulty in this way. These will be described in detail later on. There can be but little question that the water-carriage system is the cleanest, most rapid, most convenient, and cheapest method of sewage removal. The dry system, or the conservancy system as it is * The estimate of 6 gallons is, probably, much in excess of the actual figure.
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