MTA committee smiles on Vanderbilt Yard plan; new memo discloses longer time frame, less intensive work overall (but 95 caisson piles using drill rigs)
Following the receipt of a Staff Summary indicating the work would be helpful while the delay not harmful, LIRR President took a few questions from committee members. The concurrent work, he said, means Forest City doesn't "have to come back after the fact and disrupt the yard and disrupt the foundation."
The delay affects full use of permanent railyard, he said. "It is not delaying the overall project. In fact it helps it."
No raised the potential pitfall, as I suggested, that the agreement might make it more difficult to unwind the deal should Forest City and its joint venture partner, the Chinese government-owned Greenland Group, not meet promised milestones, or give the joint venture leverage to gain future extensions or concessions in renegotiations.
The deal was also discussed at the Finance Committee yesterday, but I missed that discussion. It will be voted on--likely with no dissent--by the full board tomorrow.
The Staff Summary mentioned a Technical Memorandum regarding the impact of the new railyard construction plan. I got a copy of it yesterday (bottom) and excerpt it below.
The summary of the work:
The project sponsors have stated that performing the building and platform foundation work as part of the Vanderbilt Yard reconstruction work would simplify the construction means and methods, avoid complications and time associated with taking sections of what would have been a newly built Vanderbilt Yard and disrupting the operation of the yard during foundation activities, and require significantly less supporting work (i.e., shoring and bracing) for the foundation work within the Vanderbilt Yard. Further, the Vanderbilt Yard is built with layers of utilities and other substructures, including duct banks, piping, and retention basins. If the foundations are constructed as part of the Vanderbilt Yard reconstruction work, the various utilities could be installed at the appropriate elevations along the way, streamlining this work. The current New Yard Construction Completion date is September 1, 2016. With the inclusion of the proposed foundation work, the completion date would be extended by 15 months to December 1, 2017. This would represent an increase of the overall duration to complete the rail yard reconstruction work from approximately 26 months to approximately 41 months. However, there would be an overall reduction in the scope of activities at the rail yard because the proposed pre-placement plan would allow construction activities at the LIRR rail yard to be completed more efficiently. ESD has consulted with LIRR which has advised ESD, based on information the project sponsors have provided to LIRR, that the schedule developed by the project sponsors for the proposed foundation and rail yard work is reasonable, would not adversely affect current and near-term LIRR operations, and would not delay or complicate the commencement of East Side Access operations.The document goes on to describe potential new environmental impacts.
|Timetable; click to enlarge|
The document describes the platform foundation work disclosed in the 2006 Final Environmental Impact Statement, including the number of workers, trucks, and 32-month timetable for the entire new railyard:
The 2006 FEIS conservatively assumed that a 15-foot deep mat foundation would be placed within the rail yard area on Blocks 1120 and 1121 to serve as the foundation of the developments above the platforms. The 15-foot deep mat foundation was assumed to cover an area of approximately 6.2 acres over the rail yard and would require a substantial amount of concrete and excavation activities. According to the 2006 FEIS analysis, the construction of the 15-foot deep mat foundation would involve approximately 140 concrete trucks per day (20 concrete trucks during the peak activity hour) and the excavation activities at the rail yard would involve approximately 105 to 210 dump trucks per day (15 to 30 trucks during the peak activity hour). The 2006 FEIS assumed that mat foundation activities would be a part of the rail yard reconstruction work that would also include utilities activities, support of excavation and excavation activities, sub-ballast and track work, and electrical activities (i.e., installation of permanent signals and power). The 2006 FEIS estimated that rail yard reconstruction activities, including the 15-foot deep mat foundation work, would take approximately 32 months to complete.The proposed plan
The 2006 FEIS assumed that the rail yard reconstruction work would typically occur during normal construction hours (e.g., 7AM to 3:30PM on weekdays) but could occur outside of normal construction hours so as not to interfere with the LIRR train schedule. Off-hour work would be scheduled to start after the Yard had been vacated to avoid the evening rush hour and be completed before trains would return from the morning rush hour.
The document discloses the use of drill rigs and a 41-month time period:
Unlike the mat foundation approach assumed in the 2006 FEIS, the currently proposed foundation pre- placement plan assumes that excavation and concrete work would only be required in the areas where structural support is needed to accommodate the platform and residential development above. As shown in Figure 1, the foundation under the proposed foundation pre-placement plan would be preplaced on Block 1120 and at the southern portion of the rail yard for Buildings 8 to 10 on Block 1121. The proposed foundation pre-placement plan would also require the installation of approximately 95 caisson piles with the use of drill rigs, an activity that was not anticipated previously in the 2006 FEIS. This period is longer than the 32 months assumed for construction of the yard in the 2006 FEIS.Environmental effects of Phase 1 construction activities
The project sponsors have stated that performing the building and platform foundation work as part of the Vanderbilt Yard reconstruction work would simplify the construction means and methods, avoid complications and time associated with taking sections of what would have been a newly built Vanderbilt Yard and disrupting the operation of the yard during foundation activities, and require significantly less supporting work (i.e., shoring and bracing) for the foundation work within the Vanderbilt Yard. Therefore, the overall construction duration for activities at the Vanderbilt Yard (Phase I and Phase II Project work) would be reduced, although the short-term construction duration at the Vanderbilt Yard (as part of Phase I) to complete the building and platform foundation work with the Vanderbilt Yard reconstruction work would generally be approximately 9 months longer than the construction duration assumed in the 2006 FEIS. Figure 2 shows the construction schedule for the rail yard reconstruction work with the proposed foundation pre-placement plan, which is anticipated to begin in July 2014 with an approximately 41-month completion timeframe.
Despite the nine-month extension of time, the foundation work would be less extensive, since it would require fewer trucks.
It would require installation of 95 caisson piles, each taking two days to install, using two drill rigs. There's no discussion of the concentrated noise impact of such drilling, but the document says the net noise generated would be less than that estimated in 2006:
As discussed above, the construction duration for the rail yard reconfiguration work under the proposed foundation pre-placement plan is generally expected to be approximately 9 months longer than the construction duration assumed in the 2006 FEIS. However, the foundation work under the proposed foundation pre-placement plan would be less intensive overall than the foundation work anticipated in the 2006 FEIS because excavation and concrete work would only be required in the areas where support is needed under the proposed foundation pre-placement plan (rather than a 15-foot deep mat foundation that would be required throughout the rail yard area). The proposed foundation pre-placement plan would therefore require substantially fewer concrete trucks and dump trucks than the number of trucks estimated in the 2006 FEIS. Although the proposed foundation pre-placement plan would require the installation of approximately 95 caisson piles with the use of drill rigs, an activity that was not anticipated previously in the 2006 FEIS, the installation of the piles would be spread out over an 41-month construction period such that the pile installation activities would not persist on a daily basis for an extended period of time. It is anticipated that 2 drill rigs would be on-site when needed to install the caisson piles and that each caisson pile would take approximately two days to install. Caisson installation activities would include pile drilling, rebar installation, and concrete pour (a much smaller amount of concrete is required for the 95 caisson piles compared to the 15-foot deep mat foundation assumed in the 2006 FEIS). Therefore, the net result (substantially less excavation and construction work but additional caisson piles to be installed) is that the traffic, air pollutant emissions, and noise generated under the proposed foundation pre- placement plan would be less than those estimated in the 2006 FEIS.Also, there would be less overlap of work, meaning less intensive peak periods an thus no new significant adverse impacts:
Further, the 2006 FEIS conservatively assumed an intense level of overlapping construction activities to complete both Phase I and Phase II of the Project over a 10-year construction period, including the Arena construction, Vanderbilt Yard reconstruction work, Urban Room construction, transit connection activities, foundation activities for the platform, as well as activities for Buildings 1 through 4 and Site 5. Fewer project elements are expected to be constructed simultaneously with the foundation work for the platforms and Vanderbilt Yard reconstruction work under the proposed pre-foundation plan than the work contemplated in the 2006 FEIS, especially considering that the most intense Phase I construction activity—Arena and transit connection construction—has already been constructed, thereby lessening overall construction impacts. Additionally, rail yard reconfiguration construction work, including foundation pre-placement, occurring simultaneously with construction of other Phase I and Phase II Project elements, would constitute only a portion of the over-all construction activity on the Project site, and consequently the change in completion date for the permanent rail yard would not extend the total duration of construction activity, nor would it extend the total duration of traffic, air pollutant emissions, and noise associated with construction activity. Therefore, the change in the completion date for the permanent rail yard would not result in additional peak periods of construction activities not previously identified in the 2006 FEIS.Environmental effects of Phase 2 construction activities
Given that the Final Supplementary Environmental Impact Statement "conservatively assumed that building and platform foundation work would occur as part of the Project’s Phase II activities," the shift to Phase 1 would mean less of an overall impact:
If the building and platform foundation work were to move from Phase II to Phase I and coincide with the Vanderbilt Yard reconstruction work as currently proposed, there would be fewer Phase II construction activities associated with platform construction and therefore the scope of work for platform/building foundations during Phase II of the Project would not exceed the scope of work analyzed in the SEIS. In addition, the supporting work (i.e., shoring and bracing) for the foundation work within Vanderbilt Yard that was assumed to be a part of Phase II platform construction in the SEIS would be significantly reduced. Extension of the completion date would avoid disruption of LIRR operations that would occur in order to place building and platform foundations as part of Phase II construction and eliminate the risk of disruption to electrical and track elements put in place during the yard’s reconstruction. Therefore, Phase II activities involving platform/foundation construction under the proposed foundation pre-placement plan would be substantially less than the platform/foundation construction work assumed in the SEIS and consequently would not result in any new significant adverse impacts, including in the areas of transportation, air quality, and noise, not already identified in the SEIS.This of course is a bit of a dodge. Phase 2 is the project east of Sixth Avenue, and it will proceed even while Phase 1 is being completed.
The Tech Memo concludes:
Overall, the proposed foundation pre-placement plan would involve less construction activities than those assumed in the 2006 FEIS and would not result in any new significant adverse impacts, including in the areas of transportation, air quality, and noise, not previously identified in the 2006 FEIS or SEIS. Additionally, mitigation measures to address significant adverse construction noise impacts and other measures to minimize diesel-related air emissions were developed assuming the more conservative 2006 FEIS Phase I foundation approach, and assuming the conservative 2014 SEIS Phase II foundation approach. These measures have been and will be implemented in connection with this work throughout the study area as part of Project construction. For these reasons, the proposed foundation pre-placement and associated change to the completion date for the permanent rail yard would not result in new significant adverse impacts warranting further study.