Tenders are invited from suitably qualified contractors to submit proposals for undertaking the construction of the raw and treated interconnecting water pipelines as a part of the Gore water treatment plant upgrade programme. The raw water from the Jacobstown wells to be conveyed to the water treatment plant at East Gore. The treated water to be conveyed from the treatment plant to connect to the current raw water pipelines supplying the Hilbre WTP near the Jacobstown wells. Over most of their length, both pipelines will be in the same trench. Both pipelines cross the Mataura River within steel sleeves constructed as part of the Longford pedestrian and cycle bridge.

The contract incorporates two separable portions, one for the bulk of construction works and a second for the tie-in works to be coordinated with overall scheme commissioning.

The Contract Works include the following:

1. A rising main linking the existing Jacobstown bores to the upgraded Wentworth St Water Treatment Plant (WTP). This pipeline includes the renewal of a 1970’s era DN300 AC raw water rising main from Woolwich St to the WTP, subject to budget confirmation. In total, this pipeline is about 3.1 km long;
2. A treated water main linking east and west Gore treated water reservoirs. This pipeline is also about 3.0 km long.
3. An aerial crossing of the Mataura River via installation of both pipes within steel pipe sleeves suspended from the underside of the bridge (steel sleeves and all bridge construction by others).
4. Co-ordination with other contractors working on separate elements of the WTP Upgrade project and on the Longford Bridge pedestrian walkway and cycleway project.
5. Completion of Separable Portion B works and providing pipelines commissioning support as part of a commissioning programme co-ordinated by others.
6. Pipeline detailed design and Construction Drawings in Appendix CC.1 are based on welded PN12.5 PE100 HDPE pipe. Alternatives using PN12 PVC-U would be considered, subject to additional detailing of thrust restraint by the Contractor. Refer to the Request for Proposal document for more details.

Specific exclusions from the scope of the Contract Works are:

1. Upgrading work to the water treatment plant in Wentworth St – this work will be completed under a separate Contract, but both contractors will be required to co-ordinate works between the two contracts;
2. Construction of a bridge and associated steel sleeve pipes across the Mataura River;