Strategic landfills: support climate impact mitigation in Hong Kong

SUEZ operates two of the world's largest strategic landfills beyond and above the technical and environmental requirements. Every day, we support the city to manage 13,600 tonnes of waste and recover landfill gas for energy. With less fossil fuel consumption, we support the city to reduce greenhouse gas emissions and mitigate climate impact.

The challenge
Hong Kong is densely populated and land resources are scarce. With over 7 million people in a thousand square-kilometre territory, the city has generated over 16,000 tonnes of waste every day. Its daily per capita domestic waste generation rate is high when compared to cities in Asia at stages of economic development similar to Hong Kong. Even after waste reduction, waste recovery and waste-to-energy conversion, the remaining solid waste such as ash and residue generated from incineration, putrescibles that cannot be recovered, still requires effective disposal.
Our solution

Operating two strategic landfills to produce green energy, preserve resources

In the 90s, the Hong Kong government entrusted SUEZ with designing, building, operating and restoring the WENT (West New Territories) and NENT (North East New Territories) landfill sites. The two landfills have a capacity of 63 Mm3 and 35 Mm3 respectively. Currently their total treatment capacity accounts for 87% of landfilled solid waste in Hong Kong. After completion of operation, SUEZ will support the aftercare of the landfill for another 30 years to minimize potential adverse impacts on the environment and to render the land safe for beneficial use. To enhance the visual amenity of the area, part of the WENT landfill has already been restored for greening.

98 million

m3

Total storage capacity of the two strategic landfills in Hong Kong

360

ha

Surface area of the site, including 173 ha allocated to landfill

SUEZ has designed and built facilities meeting several purposes:

  • secure containment and processing of leachate produced from liquid percolating through solid waste
  • landfill gas processing and its transformation into biogas and electricity
  • safeguard the environment nearby from pollution

A secure containment facility

SUEZ incorporates high-density, multi-layer composite coating systems covering the entire surface of the landfill site, complete leachate collection and processing equipment. The latter contains biogas and liquid leachate for further treatment to avoid environmental risks.

The environmental, health and safety (EHS) management systems at both NENT and WENT are certified in accordance with ISO14001:2015 and OHSAS18001:2007 system. We are planning to upgrade our health and safety management system to ISO45001:2018 in the near future. These management systems create a robust framework for managing our EHS performance. NENT is also the first landfill site to have ISO9001 certification in Hong Kong. Its quality management system is currently certified in accordance with ISO9001:2015.

Landfill gases recovered

NENT and WENT are one of the best examples of the recovery and reuse of “green” energy in the world.

The anaerobic degradation of waste in a landfill environment produces landfill gas. Once landfill gas is collected, it is used as a renewable energy source for ammonia stripping at the leachate processing station and on-site power generation at both landfills. Surplus landfill gas is either processed into Synthetic Natural Gas and transmitted to local town gas plant as an alternative heating fuel or transmitted to power generation units connected to existing power grid.
The results

Safeguard the environment nearby from pollution

SUEZ ensures safe operation of the landfills and minimize their environmental impact. Additionally, the recovery of landfill gas support conservation of depleting natural resources – fossil fuel, as well as support climate impact mitigation in Hong Kong.

4.9 million

tonnes

of waste buried every year in both landfills

40 million

m3

of landfill gas collected and used for energy/electricity production annually