The existing "Sha Tau Kok Sewage Treatment Works (STKSTW)", which was commissioned in 1989 with a design capacity of 1,660m3/day at average dry weather flow (ADWF), currently provides secondary level treatment to sewage collected from Sha Tau Kok township. It consists of oxidation ditch, sedimentation tanks and UV disinfection to handle the sewage collected. The effluent from STKSTW is discharged to the sea via a 250mm diameter submarine outfall.
The existing capacity of STKSTW is expected to be used up by 2019 and hence the capacity of existing STKSTW has to be increased by 3,340m3/day to 5,000m3/day (ADWF) in Phase I and by another 5,000m3 to 10,000m3/day (ADWF) in Phase II. The treatment process of STKSTW shall be membrane bioreactor (MBR). To minimize environmental impact and enhance cost effectiveness, the civil works for the construction shall be carried out in single phase while phased installation shall be carried out for E&M works and sewage treatment facilities.