The design, construction and operation of the San Wai Sewage Treatment Works Upgrading Stage I project is the largest single project of the Hong Kong Government’s Drainage Services Department to date. The project includes 21 building structures including office building, pumping station, chemical primary strengthening treatment room, sludge dewatering plant, ultraviolet disinfection plant, 554m of travel lanes, 1500m of drainage pipes, 6,593m2 of landscaping works and the corresponding equipment and systems for sewage treatment.

The successful completion and commissioning of this project will successfully replace the existing sewage treatment plant, increase the average daily sewage treatment capacity while upgrading the treatment technology, enhancing the quality of sewage treatment and improving the standard of sewage treatment from basic treatment to chemically enhanced primary treatment plus disinfection; expanding the treatment capacity to 200,000 cubic metres.

The project will improve the treatment standard of the San Wai Sewage Treatment Works to reduce the pollution load on the Northwest New Territories waters and increase the capacity of the plant to handle the additional sewage generated by the population growth in the Northwest New Territories, to meet the needs of the future population development plan of the Northwest New Territories and to effectively solve the domestic sewage treatment problem of the population.