Trunk Water Mains at 8th Avenue in Manhattan

Tectonic provided inspection, management and coordination for the $60M installation of trunk water mains in the Jackson Square area, private utilities relocation, and capital work at 8th Avenue from West 12th Street to West 13th Street to connect Shaft 27B (Water Tunnel #3) to the distribution system in Manhattan.

Since contract plans indicated that the accuracy, extent and sizes of underground structures/facilities were not guaranteed, Tectonic developed a thorough subsurface investigative plan to accurately establish the profile types of City and private utilities within the impact zone of the proposed trunk and distribution mains, and appurtenances. Tectonic provided the following recommendations for minimizing the impact on the project time and budget:

• Coordination of a comprehensive schedule of test pits prior to approval of trunk main drawings.
• Addressing potential asbestos facilities and soil contamination encountered during excavation.
• Properly implementing joint bidding.
• Constant coordination with Con Edison to identify and mitigate interferences in the vicinity of oil-o-static facilities.
• Relocating electric and gas main facilities that lie parallel to the trunk mains.
• Identifying and mitigating steam interference.
• Working closely with NYC DOT to schedule construction in the nine intersections across the project and minimize traffic delays.
• Performing detailed evaluations of the designed locations of the 36” trunk main throughout the project.
• Coordination with NYC DOT and NYCT to relocate the four Manhattan bus lines within the project limits.
• Coordination of proper building access and noise mitigation for the residential and commercial properties located near the 8th Avenue area.