Disposal of Treated Effluent

Treated effluent from SCISTW is discharged to the waters southwest of Stonecutters Island via a 5m diameter, 1.7km long tunnel which passes under the Northern Fairway at a depth of about 100m. The outfall tunnel is connected to a 1.2km diffuser pipeline laid in a pre-dredged trench on the seabed through two riser pipes. The effluent is dispersed into the tidal stream through 24 diffusers installed along the diffuser pipeline.