In a recent Colloquium, Ir Tony Leung (Chief Engineer, Cavern Projects Division, Drainage Services Department, HKSAR Government) shared his insights on the Relocation of Sha Tin Sewage Treatment Works (STSTW) to Caverns with the audience. This colloquium covered the background of the project, adoption of compact sewage treatment technologies in the project and innovative technologies applied in the construction works.  The speaker also briefly introduced the department-wide effort of the Drainage Services Department in increasing the use of renewable energy and innovative solutions.