Odours in Chinese quarters.
Main sewera to be
1.4
I realize that no system of drainage will alter the nature of the odors of the Chinese quarter, which are not necessarily unhealthy, as evidenced by experience of Canton, where the surface of the narrow streets is formed by the granite covers of the main sewers, and the large open joints of the cover stones ensure very thorough ventilation to the sewers, which are therefore practically open channels.
I disagree entirely with the opinion of Mr. COOPER, that practically nothing constructed can be done with the main drainage, till the bouse connections are first part in
Sir ROBERT RAWLINSON distinctly states:----
first. then house drains.
Suggestions
in carrying
out the
drainage.
order.
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"In sewering a town or village, the main sewers should first be completed, side junctions for branch drains, and house junctions having in all cases been provided, and indicated on the plau. House drains in detail may then be proceeded with.”
This appears to me to be but common sense, as until the level of the main sewers are settled and the junctions put in, it is impossible to lay out the house drains to the best advantage, and it is useless to discharge, through the most perfect house drains, sewage matter into imperfect or unventilated sewers. If sewage gas be formed it has to be discharged somewhere, and if not in the streets then in the back yards.
I would. in carrying out the drainage of this City, take an outfall, re-model of procedure it, ventilate, repair or reconstruct the main sewers and tributaries; when this work has been completed, then by suitable laws, the owners of tenements should he compelled to connect in a proper manner to the sewers, in accordance with by-laws passed (I may mention it was with regret that I noticed that the Sanitary Board has lately passed by-laws forcing the Separate System on house owners whether traps are insisted on or gratings only, as I propose, is merely a detail; the effect in a few years will be the same, only I would by clear instructions and efficient supervision insist on the proper construction of the drains and connections.
Remarks on estimates and cost.
Conclusions.
By taking each ontfall, and consequently each natural line of drainage separately, the re-modelling of the drainage of the Chinese portions of the city would become a comparatively simple operation, and could be completed in a far less period of time than the difficult scheme proposed by Mr. COOPER.
Not having been permitted to examine the estimates of Mr. COOPER'S Scheme, and the drawings giving no details, I am unable to discuss this absolutely necessary part of any Engineering work, but I will unhesitatingly state, that the works be proposes cannot be carried out for the total figures in his estimate. viz.: $230,000 exclusive of the North Point Pumping Station, and that $400,000 will be nearer that cost; and the complete scheme including the proposed North Point Sewer and Pumping Station about $550,000 will be approximately the cost. The scheme as proposed by me would, not only dispense with all the necessary pipe sewers of the Separate System of the entire Red area, but also the very expensive collecting sewers along the lower levels for the purpose of discharging at four points only, and no pumping station would be required, therefore, whatever figure his scheme may cost, that proposed by me can be done for about half the amount, and I trust I have proved will be more efficient in results, viz.: the rapid drainage and disposal of the sewage matter and rainfall of the City.
In conclusion I will briefly sum up the arguments of this report:- 1.--That owing to the dissimilarity in point of acreage to population, the Chinese districts coloured Red may be dealt with in a different manner to the European districts coloured Yellow. The Red containing 373 persons per acre and the Yellow 93, or a difference of just four times.
2. That the customs, habits and mode of living of the people occupying
the two districts are entirely dissimilar.
3
-That the Separate System for the European districts, and combined for the Chinese, are the most suitable, and the two districts are thereby disconnected, there being no communicating drains of any sort between the entirely Chinese parts of the City and those principally occupied by Europeans. This might prove of great benefit should certain epidemics break out and would prevent sewage gases ascending
15
from the Chinese thickly populated districts up the steep sewers (which act almost as chimneys) to the Europeans living above; this being a cause tending to make the upper levels the more unhealthy.
4. That the subsoil water which crops out almost entirely in the yellow areas can easily be dealt with by connecting it direct to the rain water drains.
5. That the Yellow portions are eminently suited to the adoption of the Separate System, while any attempt at separation of the Red portions, must prove a failure.
6. That the two systems are more economical than the adoption of the Separate Svetem for the entire City, and that it will do away with the many very serious complications that would arise in the narrow streets, and thickly populated portions of China Town. 7.-That separation in the Chinese districts is unnecessary and uncalled for, is extremely difficult and expensive to carry out, with the four outfalls proposed, which necessitate intercepting sewers and perhaps pumping.
8. That the adoption of the Combined System, with numerous proper outfalls, would ensure the complete and rapid disposal of the sewage of the Chinese districts, and utilize, in a thorough manner, the large amount of excellent work done by the Government during the past six years.
છે.
That the scheme of drainage proposed by me would be less costly, more effective, and easier of execution than the very expensive scheme of Mr. COOPER.
I shall, if required, be willing to furnish complete detailed plans, specification, and estimates, for the complete drainage of the City.
I have the honour to be,
Sir,
Your obedient servant,
R. K. LEIGH,
Assoc. Mem. Inst. C.E.
574