Quality of Supply
10.81. The chemical quality of supply continued to be influenced by the quantity of water abstracted from Plover Cove reservoir which at the beginning of the year contained about 10 times (reducing by autumn to 7 times), the concentration of dissolved salts present in other resources. Principal characteristics given in p.p.m. were as follows:
Maximum Average Hardness (as CaCO3)Sodium chloride (NaCl)
Total dissolved salts Apr. 1970
113
385
570 May 1970-
1970-71
Mar. 1971
64
36
187
70
290
130
10.82. Fluoridation of supplies, which started in 1961 to reduce dental decay in children, continued, the average level being 0.8 p.p.m. compared with a nominal target of 1.0 p.p.m.
10.83. Bacteriological quality throughout the distribution system was exceptionally good. The standard aimed at is absence of coliform organisms in 100 millilitres of sample. Of 2,753 samples taken from service reservoir outlets 99.96% conformed to this standard. Random samples were also taken from consumers' premises and public stand pipes, 99.94% of the 1,847 samples taken from taps connected directly to water mains, and 98.6% of the 1,306 samples taken from taps fed via private storage tanks being free from coliform organisms. These are the best results achieved within the last decade.
General
CONSULTANTS LIAISON UNIT
Senior Engineer:
S. K. KWEI, B.Sc. (Eng.), C.Eng., M.I.C.E.
10.84. The unit is responsible for liaison with consulting engineers working on water supply schemes for the Hong Kong Government. Expenditure on works during the year amounted to about $55 million.
Plover Cove Scheme
10.85. Outstanding defects in the electrical plant at the Tai Mei Tuk pumping station were rectified. An order was placed for the equipment required for the floating limnological station at the Plover Cove reservoir.
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