The Star. TUESDAY, MAY 2, 1871. THE CITY DRAINAGE.

Star (Christchurch), Issue 1001, 2 May 1871, Page 2

The Star. TUESDAY, MAY 2, 1871. THE CITY DRAINAGE.

Lieut.- Colonel Ewabt, in a valuable report on the drainage of certain towns in England, says : — " The primary object of every system of town drainage is a sanitary object, and involves the continuous and complete removal of sewage matter from human habitations to a place where it can be disposed of without prejudice to health." The truth of this proposition is so self-evi-dent that it requires no comment. Before, however, proceeding to examine the provision made in Christchurch for the removal of the sewage matter, principally consisting of house slops, it may be well to devote a little time to consideration of the composition of these slops and the effects of their decomposition upon the public health. The liquid sewage which runs in the surface drains of the city, contains a quantity of solid organic animal and vegetable matter — the produce of the kitchen and scullery, as well as liquid fcecal matter from other parts of the dwellings. There is also the drainage from stables, breweries, and similar places. As the sewage matter flows along a portion of its solids is precipitated to the bottom of the surface drain ; chemical decomposition setting in facilitates the precipitating process, and as the decomposition advances a putrescent mass is formed, which gives forth exhalations most prejudicial to health, and in many instances affecting even life. In fact, the air is poisoned to a greater or lesser extent around the putrifying mass. It is for this reason that it becomes of vital importance that the sewage matter should be continuously and completely removed. This and a continuous supply of pure water have been insisted on as absolutely necessary. Dr Parkes, in his valuable work (" A Manual of Practical Hygiene, Ed. 1869"), speaking of an inquiry into the effects "arising from the introduction of efficient sewerage and a good water supply, says : — " The general result is to show that these sanitary improvements have resulted in the lowering of the death rate in nineteen out of twenty-five towns, the average reduction in these nineteen cases being 10*5 per cent. The reduction in typhoid (enteric) fever was extremely marked, and occurred in twenty-one towns out of twenty-four, the average reduction being 45"4 per cent, in the deaths from typhoid. * * * * As far as can be seen, the effect of good sewerage has been to reduce the general death rate, especially by the reduction of deaths from typhoid and cholera (and in some towns from diarrhoea) but partly, and in all probability by general improvement of the health. The action has been, in fact, very much in the direction we might have anticipated." Hence the importance of the continuous and complete removal of sewage matter from the vicinity of human habitations. Has this been effected by the system of surface drainage at present prevailing in Christchurch ? We unhesitatingly affirm to the contrary. The side drains — only part of which are stone channeled and all of which are more or less flushed with water from the artesian wells — do not continuously and completely remove the sewage from the vicinity of the dwellings. A walk round the Triangle of a warm night, or in the day time in Gloucester street from Colombo street to Hereford Btreet, in Manchester street at its junction with Cashel street, in Durham street near the Whately Ttoad, and in other parts of the city will afford conclusive although not very pleasant evidence that such a removal is not effected. Surface drains were never intended for the removal of liquid sewage such as house-slops, but for the conveying away of storm water ; neither will stone channeling and flushing the drain*: prevent the evil results of their bein<* used for liquid sewage, and for tbit reason. Dust, sand, and other matter*

from the streets will accumulate in these drains, and, in spite of the flushing, this mass becomes saturated with foscal matter, a portion of which also adheres to the stone channeling itself. It is true that an attempt is made to cleanse these by sweeping, but what is the result ? The solid matter where the incipient poison chiefly exists is drawn outside and left to lie on the side of the drain exposed to the action of the sun and the atmosphere, which greatly facilitates the putrefactive process. A large portion of the fermenting mass is however continuously carried into the Eerry Boad Drain, there to accumulate until it is now a source of danger) not only to the dwellers in that locality but to every passer-by. j Thus we have within and without the city a pestiferous mass poisoning the air — a mass which, both in the streets atid suburbs, day and night gives forth the deadly malaria — " The pestilence that walketh in darkness, the destruction that wasteth at noonday." im.*Ta*l*«l*******M**'*M**-***^