DSD conducted a preliminary technical assessment on the relocation of SWHSTW.

Candidate sites considered for the relocation include:

1. Sha Ling
2. Land at the south of Lo Wu Station
3. Tai Shek Mo - Cavern sewage treatment works option
4. Cham Shan - Cavern sewage treatment works option
5. Ki Lun Shan - Cavern sewage treatment works option
6. Fu Tei Au

Assessment factors include:

1. Geology suitability
2. Landownership
3. Environmental and Ecological impact
4. Traffic impact
5. Cope with sewage flow build up
6. Impact to upstream sewerage diversion
7. Other technical considerations

The assessment results are briefly described as follows:

1. Sha Ling: About 70% of area is private land. Long time for land resumption, and the relocation programme is unable to match with the sewage flow build-up. Excavation will be near rail lines, Ng Tung River, and affect traffic.
2. Land at the south of Lo Wu Station: About 30% of area is private land. Long time for land resumption, and the relocation programme is unable to match with the sewage flow build-up. The area is now zoned as Conservation Area (CA), has high ecological value. It would take a long time to conduct zoning amendment and expects difficulties.
3. Tai Shek Mo: The geology of this area is metasedimentary rock with valleys and faults. Previous landslides had occurred at the area. This type of geology is not suitable for relocation of SWHSTW to caverns.
4. Cham Shan: Rocks thereat are highly fractured. Limited height, not enough space, presence of water tunnel and service reservoir. It is not suitable for relocation of SWHSTW to caverns.
5. Ki Lun Shan: The geological structures of this area is valleys and fault, large amount of natural terrain landslide incidents. Its location is remote from existing plant and it needs to construct pumping station and sewerage network. It is not suitable for relocation of SWHSTW to caverns.
6. Fu Tei Au: About 40% of area is private land, existing residential building structures. Land resumption may take long time. The relocation programme cannot match with the sewage flow build-up.

To sum up, the relocation options for SWHSTW cannot match with the projected sewage flow build-up. It is therefore necessary to consider in-situ SWHEPP Improvement Scheme with the use of adjacent land.