The projects “Relocation of Sha Tin Sewage Treatment Works to Caverns”, “Lai Chi Kok Drainage Tunnel” and “Sludge Treatment Scheme Developed on Co-settling” of the Drainage Services Department (DSD) have respectively been bestowed the Winner in the category of “Marketing and Communications”, the Winner in the category of “Design Projects” and the Honour Award in the category of “Small Projects” in 2014 International Water Association East Asia Regional Project Innovation Awards.

DSD’s “Relocation of Sha Tin Sewage Treatment Works to Caverns” is a mega project implemented for the effective use of underground spaces.  To intensify the public’s understanding of sewage treatment works in caverns and the relocation project, an innovative “Experiential, Multi-platform and Iconic” approach has been adopted in conducting the public engagement activities to enable the public to have first-hand experience at the project facilities.  The project has also accomplished the goal of proactive communication with stakeholders, and jointly optimizing and implementing the project with the public through the multi-platforms and the iconic mascot “Dr. Marmot” in introducing the project.

“Lai Chi Kok Drainage Tunnel” is a large-scale project that demonstrates DSD’s novel design idea.  The tunnel intercepts rainwater of the upland catchment at mid-hill and discharge the runoff to the sea direct upon bypassing the downstream urban area, thus relieving flooding risk of North West Kowloon.  During construction, the project successfully completed the drainage tunnel in two completely different ground conditions with one specially designed tunnel boring machine.  The project did not need the additional tunnel boring machine, and hence saved substantial construction cost and social resources.  Last but not least, this is the first project in Hong Kong to adopt compressed air operation of up to 4.2 times atmospheric pressure; a tunnel section of 45m deep in soft ground was successfully completed with the excellent safety record of zero “decompression illness”.

“Co-settling” technology implemented by DSD in Sha Tin Sewage Treatment Works provides an alternative path for a portion of the surplus activated sludge from secondary treatment to return to the primary sedimentation tank, which allows the processes of sedimentation, biological treatment and sludge thickening to be carried out simultaneously, and thus saves time and resources on sludge treatment.  The technology has conserved about 6.6 million kWh electrical energy, reduced 3,000 tonnes of carbon dioxide emission and avoided about 700 tonnes solid waste for Sha Tin Sewage Treatment Works each year.

Secretary for Development, Mr. CHAN Mo-po, Paul, MH, JP, also speaks on innovative flood prevention and drainage system and the IWA Awards on his blog on 8 June, 2014.

For more details, please browse Secretary for Development 's blog (http://www.devb.gov.hk/TC/home/my_blog/index_id_76.html). (Chinese version only)