ENG-1970 — Page 199

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PUBLIC WORKS AND UTILITIES

As the High Island Scheme will leave little scope for further extension of conventional water supply, the possibilities of desalting are being carefully considered. An experimental desalting plant of 50,000 gallons per day capacity has been ordered and will be operating early next year. It will be used to confirm the suitability of sites for large-scale desalting, to test materials for the construc- tion of large desalting plant in Hong Kong and to determine the treatment necessary to make desalted water suitable for injection into the distribution network. The best method of introducing large-scale desalting to Hong Kong is also being studied.

Along with these plans for new and different sources of water, work continues on new service reservoirs, pumping stations and pipelines to provide for growing demand in existing and new areas of development.

At Castle Peak, for example, in the western part of the New Territories, a new supply system is nearing completion, comprising a raw water tunnel, pumping station, treatment works, service reservoir and distribution system. This will provide up to six million gallons per day for the new town growing at Castle Peak, and the system is designed for expansion in stages to a capacity of 60 million gallons per day.

The rapid growth in demand has presented problems in ensur- ing sufficient local pumping, treatment and distribution facilities, since provision of new pumps,etc takes many months and demand growth is not uniform-in time or geographically-and is difficult to predict. However, these problems have been overcome in the past year by improvisation, and plans have been made to provide a greater proportion of spare capacity in key pumping stations in future.

Work on the government's programme for providing fully treated supplies to towns and villages in the New Territories continued, and work was in hand to give or improve supplies to the outlying islands of Cheung Chau, Tsing Yi, Kat O and Lamma. Irrigation works continued with the construction of 37 small irrigation dams, 31,000 feet of irrigation channels and the laying of 8,000 feet of pipes.