The Environmental Protection Department (EPD) completed the Outlying Islands Sewerage Master Plan (SMP) Study in 1994 and drew up a SMP for Lantau Island and other outlying islands.  The proposed sewerage works of the SMP were divided into two stages.  The proposed sewerage works for South Lantau falls under the Stage 2 Works.

The Stage 2 Works of the SMP were subsequently reviewed by EPD under the Outlying Islands Sewerage Master Plan Stage 2 Review (SMP Review Study) in 2001.  The proposed sewerage works for South Lantau were further reviewed in 2008 under the Review of Sewerage Scheme for South Lantau (Review Study).

Outlying Islands Sewerage Stage 2 – South Lantau Sewerage Works is a designated project (DP) under F.1 and F.2 of Part 1, Schedule 2 of Environmental Impact Assessment Ordinance (EIAO) with the Environmental Impact Assessment (EIA) Report (Register No. AEIAR-210/2017) and the associated Environmental Monitoring and Audit (EM&A) Manual was approved on 24 April 2017.

This DP mainly comprises the construction and operation of a sewage treatment works with a design capacity of 5,800 m3 per day at Average Dry Weather Flow (ADWF), 6 sewage pumping stations, a submarine outfall of about 1.1 km in length, village sewers of about 16 km in length, trunk sewers of about 7.5 km in length and twin rising mains of about 7.5 km in length.