Explanation
1. BACKGROUND: This Ordinance authorizes the Director of Public Utilities to modify and increase the construction contract with Kenny-Obayashi Joint Venture for the OSIS Augmentation & Relief Sewer (OARS) Phase 1 project for the Division of Sewerage and Drainage; and to apply for, accept and enter into a Water Pollution Control Loan Fund (WPCLF) Supplemental Loan Agreement totaling $29,500,000.00 to finance the completion of this project.
ADDITIONAL INFORMATION
The contract modification is a result of a settlement agreed to by all parties to cover the costs of the redesign of the Tunnel Boring Machine and related work due to subsurface conditions found after the project had commenced. The contractor has continued working throughout the project though the conditions have changed.
1.1 Amount of additional funds to be expended: $29,500,000.00
Original Contract Amount: $264,506,000.00
Modification No. 1 (this Mod.): $29,500,000.00
Total (Orig. + Mod. 1) $294,006,000.00
Modification No. 1 (current) is needed to increase Contract No. EL010880 by $29,500,000.00 for the following item:
OARS1-RFP-024 - Tunnel Groundwater DSC Claims - $28,500,000.00; Additional Contingency: $1,000,000.00.
The contract documents do not provide baseline groundwater inflows for the tunnel profile as a whole, but focus on inflows for discrete water producing zones. The contract specifications did not preclude the use of a multi-mode Tunnel Boring Machine (TBM), which could operate in both the open and closed mode. The contractor selected a TBM with the intent to operate primarily in open-mode based on the data provided in the contract documents. During the first few months of TBM mining groundwater inflows were not discrete or isolated events, instead these water producing solution features turned out to be essentially significant and constant subsurface conditions.
After 10 months of mining rock averaging a 23-feet-per-day production rate with continuous ...
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