656551-1890-Report-on-Separate-System-of-Main-Drainage — Page 23

THE HONGKONG GOVERNMENT GAZETTE, 27TH SEPTEMBER, 1890.

953

This is a special requirement in the drainage of this city, as the upper levels are 400 feet above the Praya, Flap valves and during the North-east Monsoon, when the drains are the foulest for want of rain water, the wind is blow- ing directly into the present open ends of all the outfall sewers :—

a necessity.

Rawlinson's

numerous

"It has been suggested that free and open sewer and drain ventilation will so taint the atmosphere within Sir Robert "and over a town as to cause houses at a lower level to pollute those situated on the higher levels. Any serious opinion that "injury from this need not be feared, as with abundant means of ventilation, the air, within the sewers, will be ventilthea are "comparatively pure."

"Sewer and drain ventilation are insisted upon over and over again in these suggestions, because the "work is so important and is so generally absent or even wilfully neglected."

36

There are many towns in which the sewers are not ventilated because the inhabitants refuse to have any open sewer ventilator at the street surface. This is a sad mistake, as a town, having unventilated sewers and "house drains connected with them also unventilated, must have disease in excess."

The above remarks of Sir ROBERT RAWLINSON, in his Suggestions for typical drainage systems, prove the

absolute necessity for ventilation of sewers.

required, and are no nuisance.

evidence on

struction of ventilators.

I was surprised to read the evidence of Mr. COOPER before the Fever Commission, that he considered Mr. Cooper's serious harm would arise from openings in the streets in the present condition of the house drains, as it is present con- obvious from the opinion of Sir ROBERT RAWLINSON that the sewers have to be ventilated at some time, and no amount of defective house connection can justify the absence of such ventilators, which any way must improve the air in the sewers.

with the above

I do not agree with the statement of Mr. COOPER, that the gases would be drawn into the houses by Disagreement reason of the air being warmer, as the temperature of the interior of the houses is usually lower than that of the views. open street, for the greater portion of the year.

With reference to the proposed works of Mr. COOPER, the words of his report are:--

"After careful consideration of the whole of the foregoing facts and a close study of the locality, I am of opinion that the ends of efficiency and economy will be best met by

-

"1.---The construction of a new system of pipe sewers admitting only a limited quantity of surface "water and by adopting outfalls for such a system at suitable points East and West of the City.

66

"2.-The utilization of the existing drains for conveying the natural streams through the City and for carrying off surface and subsoil water."

Mr. Cooper's proposed works.

Proposed works are on the Separ- ate System.

recommended.

The proposed works are, therefore, the carrying out of what is kuown as the "Separate System."

Wherever the Separate System is capable of being conveniently carried out, it is unquestionable the more Separate System sanitary system, and I strongly recommend its adoption for the Yellow areas, but I maintain, and hope to prove, that the Separate System is totally unsuited, not to say impossible, over the Red area.

with Mr.

objection.

Mr. COOPER mentions, as an objection to the use of the same sewers for sewage and subsoil, that in case of Disagreement stoppage of foul water the sewage may back into the subsoil drains, and sewage gas escape through them into Cooper's the houses. I entirely disagree with this opinion as a reason for not adopting the present sewers on the Com- bined System for the Chinese districts. The only places, where subsoil drains are required, are in the higher districts, which I propose to deal with under the Separate System: besides, efficient ventilation to the sewers would obviate any such nuisance.

of Chinese

The entire area coloured Red is built over in a manner quite unknown at home. The width of a Chinese Description house is 15 feet from centre to centre of the side walls, leaving about 13'- 6" in the clear; they are either built houses. back to back, or have a yard or lane of about 6 feet wide. By the New Building Ordinance, this width is slightly increased for lots acquired from the Government after the passing of the Ordinance, but that cannot therefore affect the present City.

The back yards are used for washing and domestic operations, and are the receptacles of the refuse of the Utilization by houses. There is usually to be found the latrine of the house, and in days not long past, the well.

the Chinese of

the back yards.

Mr. CHADWICK's description is as follows:-

+

As the upstair lodgers have no convenience of getting rid of their rubbish, much is stuffed down into the For the same reason "down pipes, choking it, causing it to leak and saturate the walls with the filthy fluid. "also the house drain is frequently obstructed."

The back yard measuring 13'-6" by 6'-0" is little better than a sink, and, compared with the average number of inhabitants, would not contain more area per head than an English kitchen sink.