83
•2-
4. Excreta Collection Systems.
5.
6.
I understand that the Sanitary and
Medical Departments are satisfied that the 2-pail system of nightsoil collection is an improvement in all respects on the previous system and should be extended in due course to serve all floors not provided with water closets. A gradual extension of the water carriage system for sewage scei D, however, to be expected. Although water supplies will have to be augmented, I understand that the existing sewors will mostly be adequate and the Drainage Office of the Public Works Department has in preparation a scheme for provision of intercepting scwers which will enable the number of outfalls to be reduced and their positions and methods of discharge to be rationalised. Treatment of the sewage is not regarded as necessary but the possibility of prov- iding comminutors, screens or settling tanks at some of the outfalls may be considered with the object of preventing visible pollution in the Harbour.
The present cost of disposal of nightsoil by barge conveyanoc and dumping is about $540,000 per annum or $8.47 per ton.
The quantity of refuse collected daily from strects, markets, dwellings, etc. and discharged into the refuse barges for conveyance to the Kun Tong dump is estimated by the Sanitary Department to be about 800 tons. I an assured that such daily or seasonal variations as occur in the quantity of refuse are small.
I understand that this figure is based upon the known cubic capacity of the barges and an assumed average density (60 cu.ft. = 1 ton or 1 cu.ft. 37.3 lbs) for the refuse.
Another estimate
of the density of the refuse which is given in a minute dated 11.1.49 by the Superintendent of Sanitary Services on file S.D. 405/48, is 1 cu. yd. = 1,196 lbs or 1 cu.ft. = 44.3 lbs.
.
7. The present cost of disposal of refuse by barge conveyance to
Kun Tong and distribution on the dump there is approximately $970,000 per annum or $4.17 per ton.
8.
The approximate average composition of the refuse is given in a memorandum dated 22nd April, 1950, by the Secretary of the Urban Council, enclosed at 68 on file A. G. 7/6/49. I have shown the corresponding quantities on the assumption that the total weight is 800 tons per day.
By Weight
Quantity if Total Weight is 800 tons. Tons/day.
Fine dust (less than 1")
Small cinder (1" to 1")
Large cinder (over 1")
Vegetable & putrescible mattor Paper & millboard
Metals
Rags (both wool and cotton)
Glass
Boncs
Combustible debris
Incombustible debris
དགེ༈དེn+མ༄
35
14
4215 +51
32
16
8
280
112
40
40
4
32
2
16
16
128
12
100
96
800
9. Salvago. The materials which are likely to have a local market
valuc, if salvaged from the refuso, and the prices which they may fetch are discussed in memoranda enclosed at 69 (ref. S.D.482/49° of 28.11.50) and 73 on filc A.G.7/6/50: