In addition to purchase of Dongjiang water, government also investigated a technical process named desalination in 1970s, converting sea water into fresh water as another new source of water. Using the knowledge gained from a pilot, the government officially embarked on constructing the world’s largest desalination plant of the time, the Lok On Pai Desalter, in Tuen Man in 1973. The first unit was commissioned two years later. During a drought in 1977, the Lok On Pai Desalter was put into full operation. Yet, desalination was an expensive technique at that time. Thus, the usage of the plant was low, only used intermittently to augment supply under water shortage. The situation worsened towards the early 1980s due to the oil crisis, and the government finally closed down the Desalter in 1982 against such an escalated cost for desalination. However, the globe is now encountering unknown consequences of climate change. Therefore, WSD commissions a planning for a new desalination plant, using the technology of reverse osmosis which overseas also adopt, hoping to maintain the reliability of water supply in extreme weather.
Source: Water Supplies Department