The Deep Tunnel Sewerage System Phase 2 T-11 include the design and construction of a 6km South Main Sewerage Tunnel, a 5.5km South Linkway Sewerage Tunnel, fifteen working shafts and related facilities. Two 3.0m diameter slurry TBMs and three 3.3m diameter slurry TBMs. The contract value is S$472.17 million.