 |
| Artist's conception of completed pump station facade |
Status of H1 Screening and Wet Weather Pump Station
TO: Richard Wolff/Chairman/North Hudson Sewerage Authority
COPIES: North Hudson Sewerage Authority Board of Commissioners
FROM: John V. Tobia, P.E., Project Manager, CH2M HILL
DATE: November 29, 2010
Chairman Wolff:
As requested, we are providing the monthly update regarding the progress of construction of the H1 Screening and Wet Weather Pump Station project. This update is for the month of November 2010.
The contractor’s most recent progress schedule is dated November 1, 2010; we expect an update to the progress schedule during the first full week of December, 2010. The progress schedule continues to reflect substantial completion of the pump station in the spring of 2011. The following is a summary of the potential causes of future delay, other issues that need to be monitored, milestones achieved, and the most recent estimate of the project schedule:
A. Potential Causes for Future Project Delay
1. Delivery of a Critical Transformer: PSE&G has indicated that the electric power transformer has been ordered; however, they have not yet confirmed a delivery or installation date. The contractor’s estimate for the latest date the transformer can be installed is between April 13, 2011 and April 26, 2011. The pump station cannot be tested, or placed into service until the transformer is installed and energized.
B. Issues To Be Monitored
The following issues will be carefully monitored as they could negatively impact the schedule in the future. We are focused on these issues with the purpose of ensuring that they do not contribute to delays in completion of the project.
Outfall Rehabilitation and Extension: Completion of the permanent rehabilitation and extension of the existing outfall is required for operation of the pump station, as it is the sole means of conveyance of pumped flow from the system to the river. This is the most complex portion of the project and has the most potential to impact the schedule for placing the pump station into operation. Rehabilitation of the century-old existing outfall pipelines will first require that the pipelines be cleaned, inspected and all obstructions removed. We are aware of at least one instance of a structural support pile that has penetrated a pipeline from above; this pile will need to be removed, and potentially replaced with a new pile. In addition, when the pipeline cleaning is undertaken, the pipeline material will need to be monitored for signs of excessive corrosion, and temporary stabilization of the pipeline undertaken as the work progresses in order to avoid a collapse. The contractor's November 1, 2010 schedule projects completion of the majority of outfall rehabilitation and extension work by early March 2011. This date is currently earlier than the projected dates for completion of the pump station and the electric building.
C. Milestones Achieved
1. At the Pump Station, the contractor continued to install reinforcing steel and placing concrete for the pump station structure. The following pump station components were completed: exterior wet well walls, intermediate pump chamber wall, effluent channel walls, and the effluent slab. The contractor is presently placing reinforcing steel for the remainder of the wet well walls and the valve vault. The contractor also removed the second level wales that previously braced the excavation support system.
2. At the Electrical Building, the contractor completed the following: installation of the masonry roof parapet wall, and installation of the masonry infill on the first and second floors.
3. At the location of the proposed outfall extension on NJ Transit property, the contractor installed the H-piles which will support the proposed outfall extension pipelines. They also poured the tremie slab seal within the excavation support system.
4. During the month of November 2010, the contractor continued to work overtime to maintain the project schedule.
D. Current Project Schedule
The contractor’s latest project schedule on hand is dated November 1, 2010; we expect an update to the progress schedule during the first full week of December, 2010.
Based on currently available information, the startup and testing of the H1 Screening and Wet Weather Pump Station is anticipated for the period of April/May 2011. The contractor’s latest schedule is presented in Table 1.
