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Municipal Case Studies

The world’s largest sludge treatment plant, water and energy self-sufficient

Hong Kong government, Hong Kong, China

Over the last two decades, China has invested massively in modernising its wastewater treatment plants in order to respond 4 main priorities : water treatment and protection, waste management and recycling, reduce noise and improve air quality and optimise energy consumption. In May 2015, the Environment Bureau of Hong Kong launched a "Energy Savings Plan for the Urban Environment of Hong Kong 2015-2025 +" and announced its goal of reducing energy intensity by 40% by 2025.

The client’s needs

The Hong Kong government had the project to gather the sludge from 11 wastewater treatment plants of a 7,2 million inhabitants area, to treat it within one and only facility. This new sludge treatment facility had to fit with sustainable waste management strategy and with the Environment Bureau plan.

Our solution

Veolia Water Technologie was chosen or carry out the project design and a significant part of the works. Operation of the plant, under a 15-year contract, will be undertaken by Veolia.

The new sludge treatment plant, 360-metres long and 50-metres high, extends on a 7 hectares site facing Deep bay and Shenzhen. This one is mostly equipped with incineration furnace-boilers which reduce the final waste by 90%.
Conceived to be water and energy self-sufficient, this ecological facility produces renewable electricity and heat. The electricity covers the plant’s energy needs and supplies 4,000 householdsand. The heat is recovered for the heating of 3 pools and a spa located next to the plant.

The incineration flue gas treatment units operate in accordance with the most stringent emission standards.

Finally, a seawater desalination unit covers the plant’s drinking and process water needs.


The new sludge treatment facility treats 2000 metric tons/day of sludge from Hong Kong’s area. Thanks to its water and energy self-sufficiency, the Hong Kong plant provides an effective solution to the growing scarcity of water and fossil fuels, and also to the global warming and the environmental challenges of the region.

Turning waste into a source of renewable energy, this facility is a prime example of the circular economy and has become a benchmark in the water industry, illustrating the sewage stations of the future.


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