1. Following the tenders called on 8 June 2016, the Land Transport Authority (LTA) has appointed Tritech Engineering & Testing (TET) (Singapore) Pte Ltd and Ryobi Geotechnique (Ryobi G) International Pte Ltd to carry out Site Investigation (SI) works for the direct alignment option of the Cross Island Line (CRL) under the Central Catchment Nature Reserve (CCNR). This is the second set of SI works in addition to the skirting option which started in May 2016 that the Government is carrying out to analyse and determine soil conditions and engineering feasibility, so that an assessment on the alignment of the CRL can be determined.

2. TET, one of the largest SI works specialists in Singapore, has been appointed to carry out borehole drilling works (16 10-cm boreholes in total) to extract soil samples on existing trails and clearings in the CCNR. The company has extensive experience in borehole drilling, including in environmentally-sensitive areas. For instance, TET was involved in borehole drilling operations for the slope stabilisation studies in the Bukit Timah Nature Reserve and Bukit Batok Nature Park. TET has also conducted successful multiple horizontal directional coring in close proximity to underground oil pipelines and a gas-fired power generation plant on Jurong Island that were highly sensitive to ground movements and vibrations.

3. Ryobi G, supported by its subcontractor Geophysical Services Ltd (GSS), has been appointed to carry out geophysical survey works within the CCNR. The surveys will be used to supplement the limited data set obtained by the boreholes. GSS is a specialist in 3D seismic surveys, and has carried out several geophysical surveys in Singapore including on government projects such as the Thomson-East Coast Line and the former KTM corridor. As an added measure to reduce the impact to fauna, GSS will be using wireless equipment for their works.

4. The SI works for the CCNR will start in December 2016 and is expected to complete by 2017. Throughout the SI works, a dedicated team of LTA officers and the contractors will work closely with the National Parks Board (NParks) and the nature groups to ensure that all mitigating measures are rigorously implemented (see Annex A for the list of mitigating measures).

5. Both the direct and skirting alignment options are being studied. The findings from the SI works will provide inputs to Phase 2 of the Environmental Impact Assessment (EIA), which assesses the impact of construction and operations for the two possible alignments.  Only after the SI works, Phase 2 of the EIA, and taking into account the various concerns and considerations from all stakeholders as well as the potential impact on the CCNR, will the Government take a decision on the alignment.

Annex A: Mitigating Measures to Protect the CCNR during SI Works