10.19. Approximately 54 miles of pipes, varying from 2" to 27" in diameter, were laid. This included asbestos cement pipes for salt water flushing supply distributions, as well as galvanized iron pipes for sub-mains up to 4" diameter, cast iron pipes up to 18" diameter, and steel mains over 18" diameter.
10.20. The more important mains laid during the year, other than those in connection with particular projects, were:
(a) 1,500 feet of 18" cast iron main from Sham Shui Po Service Reservoir into the Tai Hang Tung area.
(b) 2,800 feet of 18" cast iron main in Cheung Sha Wan Road.
(c) 6,000 feet of 15" asbestos cement salt water main in Ma Tau Wei Road and Chatham Road.
(d) 6,000 feet of 18" cast iron main in the Mong Kok Area (Nelson Street, Canton Road and Anchor Street).
(e) 7,500 feet of mains from the sea front, via Chatham and Wylie Road to the Queen Elizabeth Hospital, to provide seawater for air conditioning and flushing, including twin 15" asbestos cement mains, a 6" steel oil pipe, and an earthenware cable duct.
(f) 3,800 feet of 6" and 8" cast iron and asbestos cement mains to supply the Aberdeen Resettlement Estate.
(g) 900 feet of 12" cast iron main to feed the Chai Wan Resettlement Estate.
Service Reservoirs
10.21. All service reservoirs were cleaned and sterilized. Inlet and outlet valves were tested and overhauled as required. Inspections showed that no major repair was required.
Catchwaters
10.22. The usual troubles on catchwaters, due to minor landslips following heavy summer rains, were experienced, but no major damage was sustained. When necessary clearance was effected in time to prevent any serious loss of inflow to the reservoirs.
Fluoridation
10.23. Fluoridation was maintained in all urban areas, as well as at Tsuen Wan. The new installation at Aberdeen came into service on 26th June.
10.24. Difficulties experienced in dissolving fluorine chemical at the two filter stations employing dry feeder machines were overcome by the purchase and installation of two small pumpsets. Discussions were held with the Dental Specialist of the Medical and Health Department, and it was found possible to maintain a more satisfactory dosage.
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