requirements contracts for engineering design and related services ...

E. The Consultant, complying with applicable City/State/Federal regulations, shall retain the services of a qualified soils
laboratory to classify the soil by sieve analysis in accordance with the Unified Soil Classification System, to perform
permeability tests as needed along the thirty (30) foot deep borings, and to ascertain the elevation of the existing
groundwater table.
F. The Consultant shall make a visual and olfactory examination of the soil samples retrieved from the borings to
determine the existence of noxious odors or other indicators of the presence of material that may be classified as
hazardous.
G. Data obtained from the boring program shall be recorded in a format approved by the City and shall indicate soils
information obtained and layer thicknesses encountered.
H. A photographic record of the soil samples retrieved shall be made for each boring.
I. Soil samples shall become the property of the Consultant and shall be stored in a secure location until all construction
work has been completed and all related claims settled. The Consultant shall be responsible for the disposal of the soil
samples. Storage and disposal of soil samples shall be in accordance with all applicable laws, rules and regulations.
J. Subsequent to review and acceptance by the Commissioner of the data obtained, the Consultant shall
coordinate/incorporate the results of the subsurface exploration program into the relevant tasks that are included in the
Specific Requirements for the Project.
K. When directed by DDC, in order to evaluate the appropriateness of proposed bioswale and green infrastructure
locations, the Consultant, complying with applicable City/State/Federal regulations, shall, as a Reimbursable Service,
retain the services of a sub-contractor to perform percolation tests in the proper locations. The Consultant shall take into
account the frequency, spacing and proximity of test locations when determining percolation test quantities for each
potential green infrastructure location and/or family of locations. Percolation tests should be located and conducted in such
a manner as to yield a good understanding of the rate of absorption. If the rock layer is encountered between nine (9) and
fifteen (15) feet, the Consultant must confirm with DDC that the soil profile is acceptable before proceeding with percolation
testing.
In order to further validate the assumptions and results yielded by the percolation tests and other soils testing, the
Consultant shall also perform permeability testing. The quantity, frequency and locations of permeability tests conducted
shall be as required to develop an adequate understanding of the drainage characteristics of each potential green
infrastructure site.
Permeability tests shall be performed as needed along fifteen (15) foot deep borings, and to ascertain the elevation of the
existing groundwater table. Subsurface tests shall be conducted as follows:
i. Permeability test type shall be falling head in situ
ii. Permeability tests shall be performed at depths of five (5) and ten (10) feet.
iii.
iv.
Soil infiltration rates shall be provided in cm/s.
The procedure for falling head permeability tests consists of placing approximately 6 to 8 inches of
permeable aggregate or course sand at the bottom of the casing after the casing is driven to the required
depth in a boring. The soil beneath the casing is then allowed to saturate with water for approximately 30
minutes. The casing is filled to the top with clean water, and the initial height of water (H1) in the casing is
recorded. Thereafter the drop in height of water (H2) in the casing is measured and recorded for the required
time intervals (T1-T2). Field permeability is then calculated at the desired depths based on the difference of
height over time.
4.6 VAULT PROGRAMS
4.6A VAULT PROGRAM LEVEL I
A. The Consultant shall execute Level I Vault Program- Research and Inspection in conjunction with the project.
B. A vault, whether active, inactive or abandoned shall be defined, for the purposes of this task, as any space or
enclosure below the sidewalk and/or roadway areas that is either directly or indirectly connected, at any time in the
building's history, to the contiguous building structure. Areaways shall not be considered as Vaults.
1. Each "store vault" which may have been generated, at any time in the building's history, from the sub-division of
a building vault shall be considered as one vault.
NYC Department of Design and Construction
Infrastructure, October 2012
GR-27