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Letter to the Editor of the South China Morning Post dated 14 April 2004 - Hong Kong has made considerable progress in sewage treatment
The article titled "How murky waters can create a clear identity" published on 7 April 2004, which suggests that Hong Kong made little progress on sewage treatment, requires clarification.
Since the 1970's, Hong Kong has built many large secondary sewage treatment plants which use biological processes to treat wastewater to a very high standard. They serve over one million residents in new towns at Shatin, Tai Po, Sheung Shui, Yuen Long and Sai Kung in the New Territories. The discharge into the Kai Tak nullah at Kowloon Bay is not primary sewage. It is the treated water from the Shatin and Tai Po sewage treatment plants after undergoing high level treatment, which helps to maintain a steady flow of high quality water in the nullah.
For areas around the Victoria Harbour, some 4 million population in Kowloon, Tsuen Wan, Kwai Tsing, Tseung Kwan O and part of the Hong Kong Island are served by Stage 1 of the Harbour Area Treatment Scheme (HATS) since 2001. The chemical treatment plant at Stonecutters Island helps remove 70 percent of the organic pollutants in the sewage and prevent some 600 tonnes of sludge from entering into the Harbour daily. The HATS Stage 1 brings about noticeable improvement to our harbour water quality with levels of bacteria reduced by up to 90 percent at the eastern part of the Harbour. Dissolved oxygen, which is vital to marine life, has increased throughout the Harbour by as much as 30%. Over the last 15 years, Hong Kong has spent $20 billion in upgrading its sewage infrastructures. By any standard, Hong Kong has made considerable progress in this aspect.
I would also point out that there is no reason to dismiss the chemical treatment process used at the Stonecutters Island treatment plant as a sub-standard process. Readers may like to know that such installations are helping big cities like San Diego to maintain their pristine water quality. Similarly, Sydney uses only the conventional primary treatment process (i.e. without chemical enhancement) plus oceanic outfall to dispose of the bulk of its sewage so as to protect the quality of water in Sydney Harbour and its surrounding beaches. The treatment plant at StonecuttersIsland has been rated by a panel of international experts as one of the best performing plants in the world.
Notwithstanding the above, we recognize that more needs to be done. We are committed to moving ahead with further plans for expansion of sewage treatment facilities in the territory, including the remaining stage of HATS. Implementation of these plans requires full support of the community. To this end, we would encourage more public debate on the community's aspirations, including recycling of treated effluent for various uses. Such debate must be based on accurate facts and information.
On the earlier proposal to convey effluent after treatment for discharge into the South China sea, the Mainland authorities were consulted fully during the environmental impact assessment process. Far from blocking the plan, they endorsed fully the environmental acceptability of the proposal.
Benny Y K Wong
Assistant Director (Waste & Water)
for Director of Environmental Protection
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