2018.11.02 DRE Memo
TO: Paul S. Rosenberg, Mayor, and the
Village of Rye Brook Board of Trustees
FROM: Anthony Oliveri, P.E.
SUBJECT: 900 King Street Redevelopment
Draft Environmental Impact Statement (DEIS)
PUD Concept Plan and Preliminary Site Plan
DATE: November 2, 2018
With regard to the above mentioned project, this office has received and
reviewed the following:
1. 900 King Street Redevelopment, Draft Environmental Impact Statement
(DEIS), and appendices dated September 12, 2018 and prepared by
AKRF, Inc.
2. Plan entitled: "PUD Concept Plan and Preliminary Site Plans, 900 King
Street Redevelopment", prepared by JMC, last dated September 5, 2018;
Our comments are as follow:
1.) It should be noted that this office reviewed only the sections of the DEIS
which are pertinent to site engineering issues which DRE typically
reviews, including sections of Chapters 2, 4, 6, 11 and 16 and related
appendices. The site plan submitted is considered a "preliminary site plan"
for the purposes of the DEIS study; a final site plan and construction plan
approval would be required prior to commencement of any construction.
2.) As noted previously, Section 11.2.3 of the Scoping Outline required an
analysis of the capacity available while firefighting is occurring in the
vicinity. While fire flow hydrant tests have been performed, and SUEZ has
provided a "willingness to serve" letter, this analysis has not yet been
performed. The DEIS states that "confirmation of this analysis has been
requested from SUEZ". SUEZ has acknowledged problems with the
system in this area, not necessarily restricted to drought conditions. In a
previous analysis of the supply to the Sun Homes development, it was
determined that the connection to the WJWW system on Anderson Hill
Road had to be enlarged. The DEIS does not discuss the status of
increasing capacity and reliability of the system. The DEIS states that
SUEZ noted that there is infrastructure in place “to secure water from
different locations”, however this is not discussed in any detail. Additional
information is also needed on potential problems within the area supplied
by the booster system on Anderson Hill Road that would effect this
development. Particularly if an off-site fire occurs within the area served
by the booster system. If fire pumps and/or water storage are required, the
applicant should provide information now. As discussed previously, this
issue should be resolved by the time of FEIS submission.
3.) A review of the sanitary sewer flow study conducted from May 27, 2018 to
July 8, 2018 by the applicant revealed a peak flow of 68,563 gpd on June
28, 2018 that coincided with the only significant storm event during the
flow monitoring period. The rainfall totaled 1.83 inches at the Westchester
County Airport on June 28, 2018. A downstream sewer analysis
conducted by JMC found capacities in the existing system to be adequate,
however mitigation in the form of Inflow and Infiltration (I&I) removal has
been proposed. The DEIS states that the applicant agrees to mitigate
increases to sewage flow (net 35,787 gpd increase) at a three for one ratio
(107,361 gpd). This is in accordance with the Westchester County
Departments of Planning and Environmental Facilities recommendations
and should be made a condition of any future site plan approval. The
applicant agrees to either complete further investigation to identify I&I
sources in the downstream sewer system and conduct repairs or to
contribute sufficient funds to the Village's current I&I program as
mitigation.
4.) Site disturbance proposed is greater than the maximum 5 acres allowed
under the NYSDEC Design Manual. The proposed disturbance appears
to be greater than 13 acres at one time, this presents great concerns with
regard to sediment and erosion control during construction. This will
require a NYSDEC waiver with adequate use of Best Management
Practices before a final site plan can be approved.
5.) Square footage of disturbance should be noted for each construction
phase on the sediment and erosion control plans.
6.) Construction phase 1 should denote when asphalt is removed from the
existing parking lot, asphalt should be maintained during building demo.
7.) No details have been provided for the proposed temporary sediment
basin. An analysis to size the temporary basin and outlet pipe/structure
should be included to demonstrate adequate capacity for the large
disturbance proposed and extended construction time anticipated.
8.) The plan notes call for “hay bale filters” on drain inlets, these should be
noted as “silt sacks”.
9.) It may be necessary to further stage disturbance in the town house areas
& south wings of the A.L. facility since the temporary sediment basin is
removed by phase 5 of construction and no further temporary sediment
basins or traps seem to be proposed. Individual sediment traps or basins
should be added during these phases of construction as needed.
10.) Proposed realignment of the curb at the existing firehouse crosses the
property line, an easement would be required to do this.
11.) The Fire Department should verify noted fire truck dimensions on the
proposed turning plan.
12.) Road profiles will be required for review & approval; road slopes on the
west loop road seem to approach 10% in some areas.
13.) Additional catch basins should be considered within the town house areas
and front/side entry drive to avoid excessive runoff travel down the loop
roads and possibly into Arbor Drive.
14.) Connection of sanitary sewer services from the proposed town houses
directly into manholes should be avoided.
15.) Sewer main alignment between SMH-3-1 and SMH-3 is at an extremely
acute angle, this should be avoided.
16.) Sewer and drainage profiles are required for review and approval.
17.) Hoods should be added to all drainage structure outlets.
18.) Indicate locations for concrete and belgium block curbs on the layout plan,
stone curbing should be 18” in depth within the village R.O.W
19.) Handicap parking dimensions should be indicated on the details.
20.) It is required that percolation tests and test pits must be conducted in the
vicinity of all infiltration practices including Detention Pond 1B and
infiltration systems 1A-2 and 1A-3 to determine feasibility of infiltrating
stormwater and the presence of rock or groundwater. The applicant did
perform a percolation test near system 1A-2, however tests were not
performed near Pond 1B or for system 1A-3 (due to the presence of the
building); we recommend use of conservative infiltration rates in these
areas until actual infiltration rates can be field verified.
21.) The locations of all test pits and percolation tests must be superimposed
on the watershed maps contained in the SWPPP. The percolation test
method and the methodology of how the percolation rate was translated
into an infiltration rate for the stormwater model must be provided.
22.) Any future site plan approval for this project may require test pits and
percolation tests to be conducted at the time of the application. All tests
must be witnessed by the Village.
23.) Based on the existing drainage piping that is shown on the watershed
maps, the area tributary to the drain inlet at the entrance to the Hutchinson
River Parkway South (from North Ridge Street) should be included in the
“Bypass Area”. Where does the drainage go from the drain inlet that is
located on the exit ramp (to King Street) of Hutchinson River Parkway
North?
24.) The SWPPP cites the New York State Stormwater Design Manual in that if
the hydrology and hydraulic study shows that the post-construction 1-year
24 hour discharge rate and velocity are less than or equal to the pre-
construction discharge rate, providing 24 hour detention of the 1-year
storm to meet the channel protection criteria is not required. Pre- and
post-construction discharge velocities must be provided.
25.) The Boring Locations Plan prepared by AKRF does not show the locations
of PB-1 and PB-2. The locations of these borings must be provided.
26.) Sizing calculations must be provided for all proposed drainage piping.
27.) More specific storm-tech chamber details and layouts drawn to scale
should be included as opposed to generic details.
28.) The “Schedule of Inverts” tables for the two infiltration systems on Sheet
C-903 appear to include the incorrect designations and overflow weir
elevations.
29.) The invert elevations on each Stormtech chamber section (Sheet C-903)
appear to have been provided for the incorrect chamber models. All invert
elevations, section dimensions, and detail titles must be corrected.
30.) Overflow weir elevations must be reconciled among the “Schedule of
Inverts” tables on Sheets C-903 and C-904, and with the invert elevations
provided on C-500.
31.) Greater detail must be provided for how the “Initial Water Quality Volume”,
“Adjusted Water Quality Volume”, and “Minimum Runoff Reduction
Volume” values were calculated (Appendix C of the Stormwater Pollution
Prevention Plan). Calculations must also be provided for how runoff
reduction volumes are provided in the infiltration systems.
32.) Water levels must be shown on each Stormtech chamber section (Sheet
C-903) and each outlet control structure section (Sheet C-904) for all
design storms including the 90th percentile rainfall event.
We would be happy to continue our review once additional information is
received.
Thank You
C: M. Nowak M. Mohamed J. Gray
C. Bradbury M. Izzo