Project Challenge:
Compliance with the Water Pollution Control Act Amendment of 1972
requires New York City?s largest wastewater treatment plant to be
upgraded. As structural subconsultant to the Joint Venture Team, Klein
and Hoffman (K&H) is currently performing facilities planning and design
and providing construction support services to upgrade the plant to 310
mgd in order to meet federal secondary treatment standards. The
required work includes the replacement of most of the existing equipment
and major modifications of the existing facilities as well as the installation
of additional equipment and construction of new facilities under various
contracts. Several challenges of this project include:
Construction or rehabilitation of various facilities at the same time and
in the same vicinity while maintaining plant operations and access by
plant personnel and construction vehicles.
Deep excavation for new structures that could undermine existing
adjacent structures.
Poor soil conditions and groundwater problems making excavation and
construction of the new underground structures difficult.
Maintaining construction schedule to assure smooth transition of work
from one contract to another and meet the final completion schedule.
Creating the design that is efficient, yet pleasing and friendly to the
neighborhood.
Project Solution:
Techniques and procedures used to overcome these challenges include:
Complex planning in the design and construction phasing to assure
continued plant operation and accessibility by the plant personnel and
construction vehicles.
Detailed design of the excavation support systems to assure stability
and continued services of existing adjacent structures.
Utilizing deep foundation systems such as caissons and high-capacity
piles, installed from above groundwater level before excavating to
subgrade elevations and cutting off the caissons/piles to final cutoff
elevations.
Close monitoring of construction schedules and construction activities.
Modifying the design, when necessary, to accommodate the changed
conditions during construction.
Careful planning in the design layout and shapes of various facilities,
choices of construction materials that is functional and aesthetically
pleasing. Integration of facilities such as nature walk, garden and
fountains that is accessible by general public.
OWNER: New York City Department of Environmental Protection (NYCDEP)
CLIENT: Joint Venture Team: Greeley and Hansen, Hazen and Sawyer PC, and Malcolm Pirnie Inc.
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