The mission

With a population of over 7.3 million, Hong Kong generates substantial volumes of domestic wastewater every day. To meet the needs of a growing urban population and to promote the city’s sustainable development, the local government has intensified efforts to make its services more cost-efficient and environment friendly. The goal is to provide world-class wastewater treatment services. For that reason, since 2010, SUEZ and its partners have been developing innovative and effective solutions for various wastewater treatment plants in Hong Kong. These solutions improve treatment capacity and operational performance, while also contributing to the reduction of pollutant discharge and the improvement of water quality.


Hong Kong population

Our solution

Compact technical solution to overcome land constraints

At the Pillar Point WWTP, SUEZ upgraded the plant from a simple pre-treatment solution to a chemically-enhanced pre-treatment and disinfection process. Through this upgrade, the plant was successfully transformed and upgraded in a compact footprint. SUEZ was also contracted to operate and manage the plant for 10 years. It has since successfully renewed and extended the contract for another five years, until May 2029.

SUEZ uses an advanced DensadegTM high-density settling tank process that chemically enhances the pre-treatment process. The plant is equipped with a UV disinfection system and deodorizing unit. This process improves the plant’s treatment performance and increases treatment capacity, while effectively eliminating odors. Since its upgrade and expansion, the plant’s treatment capacity rose from 215,000 m3 per day to 241,000 m3 per day, with a peak flow designed up to 525,000 m3 per day. It also treats over 80% of Hong Kong’s septic waste, ensuring that the facility can meet the rapidly growing wastewater treatment demand in Hong Kong’s New Territories North West.

Advanced digital and green technologies for stable operations and maximum economic, environmental benefits

In the San Wai WWTP expansion project in the New Territories North West, SUEZ has improved its wastewater treatment performance and expanded its treatment capacity to 200,000 m3 per day. In 2021, the company was awarded a 10-year operation and management contract.

The project uses SUEZ’s DensadegTM high-density settling tank process, an upgrade from basic treatment, to chemically-enhanced primary treatment with UV disinfection. Further, the project integrates SUEZ’s proven AQUADVANCED® smart water technology to comprehensively improve treatment capacity, operational performance and environmental benefits. The project reduces pollution in northwest Hong Kong’s waters, while meeting water demand associated with a growing population and urban development in the New Territories North West.

San Wai WWTP is committed to applying green, circular solutions. A portion of the treated effluent is recycled and applied to additional processes. Concurrently, solar power generation units have been deployed on site, to generate clean energy for wastewater treatment. This advances the government’s clean energy policy and reduces the plant's carbon footprint.

The results

SUEZ provides global expertise, advanced technologies, and customized environmental solutions and services to the HKSAR Government on projects through DBO and operations and maintenance (O&M) contracts. Through the partnership, SUEZ simultaneously improves cost efficiency while meeting socio-development needs.

In these WWTPs, SUEZ has expanded treatment capacity and improved effluent quality to meet more stringent water quality standards. The company's efforts have helped reduce the pollutant load in the water bodies of northwest Hong Kong, addressing the environmental challenges associated with the city's dense population and growing demand for wastewater treatment. This ensures a clean, beautiful coastline for Hong Kong while maintaining a sound ecological environment in the surrounding waters.

  • At the Pillar Point WWTP, the integrated deodorization unit effectively removes up to 99% of hydrogen sulfide, with a maximum intake gas concentration of 80 ppm, resulting in a significant positive environmental impact.
  • The Administration Building and Workshop of the San Wai WWTP (Phase I) has achieved the BEAM Plus Final Platinum accreditation from the Hong Kong Green Building Council (HKGBC).1
  • The San Wai WWTP has a wastewater recycling capacity of 900,000 m3 per year and generates approximately 200 MWh of green electricity annually, furthering sustainable energy practices.
SUEZ’s combined wastewater treatment capacity in Hong Kong
million residents
Served by SUEZ’s wastewater treatment services in Hong Kong