Engineering
North Country Office
100 Glen Street, Glens Falls, NY 12801
P: (518) 812-0513 F: (518) 824-8391
www.chazencompanies.com
Hudson Valley Office (845) 454-3980
Engineers
Environmental Professionals Capital District Office (518) 273-0055
Land Surveyors
Landscape Architects
Planners
May 10, 2012
Mr. Craig Brown
Zoning Administrator and Code Compliance Officer
Town of Queensbury
742 Bay Road
Queensbury New York 12804
Delivered via email only: CraigB@queensbury.net
Re: Cembrook Residential Site Plan Review
Town of Queensbury, Warren County, New York
Chazen Project # 91204.12
Queensbury Ref No: Site Plan 27-2012
Dear Mr. Brown:
The Chazen Companies (Chazen) received a submission package from your office for a site
application for the above referenced project. Submitted informa
Plans entitled, John & Pamela Cembrook Residential Site Redevelopment, dated 4/11/12
prepared by Jarrett Engineers, PLLC;
House Plans, dated 3/29/12, prepared by Jon Booth;
Landscape Plans & Details, dated 4/5/11, prepared by Redbud Desi
A Stormwater Pollution Prevention Plan, dated April 2012, prepared by Jarrett Engineers, PLLC;
and
A site plan application with supporting documentation.
Your office has requested that we limit our review to the design
erosion and sediment control items as it relates to compliance televant codes and
regulations. Based on our review of the information provided, Ch
the Towns consideration:
Stormwater Management & Erosion and Sediment Control:
1.The proposed residential site redevelopment will disturb less than 1 acre of land (26,800 SF) and
will not be subject to NYSDEC Phase II Stormwater Regulations. However, Section 179-6-080 of
the Town Code states that stormwater drainage plans shall analyz
Town of Queensbury
Site Plan 27-2012 John and Pamela Cembrook
May 10, 2012
Page 2
using at least a 25-year return interval storm for residential projects. The Applicant has
submitted the required calculations for review.
2.Glen Lake is classified as a B(t) water body by the NYSDEC. Any
of this water body will require an Article 15 permit from NYSDEC, as indicated on the Waterfront
Plan. The applicant shall consult with the NYSDEC regarding this permit, and shall provide
appropriate documentation to the Town prior to construction.
3.The Pre- and Post-Development HydroCAD models indicate that time of concentration values
less than 6-minutes were used to develop runoff quantities. However, in accordance with the
NYSDEC regulations, the minimum allowed time of concentration is 6-minutes. The applicant
shall revise the calculations to use a minimum 6-minute time of concentration, where
appropriate, and shall include the revised calculations in the SWPPP.
4.There appears to be some redundancy in the time of concentrationin the Post-
Development HydroCAD model. As presented in the routing diagram, several of the
subcatchments are tributary to ponds and reaches, which represent the various stormwater
management facilities. However, the time of concentration flow p
duplicate segments that are already accounted for within the reaches & ponds. The
shall revise the time of concentration calculations, such that the values only include the flow
path up to the pond or reach to which it is tributary.
5.Several percolation tests were performed on the site and results varied from 9.4 in/hr to 22.3
in/hr. The exfiltration rates in the HydroCAD model should reflect the rate of the
test closest to the practice, or if the practice is between two different tests, the slower value
found should be used to provide a conservative evaluation. Specifically, the subsurface
detention system, designated as P6, is centrally located between PT #111129-01, -02, and -03.
As such, the slower rate of 22.4 in/hr should be used. In addition, rain garden P7 is located
between PT #111129-03, and -04 and shall use the slower rate of 19.4 in/hr for calculations.
The Applicant shall revise the calculations appropriately.
6.The Applicant is proposing a series of pretreatment swales discharging to two dry wells, in order
to manage runoff from the proposed stone/asphalt driveway. According to Section 6.3.1
Design Guidance of the NYSSMDM, the drainage area to dry wells should include roof runoff
only. As such, the Applicant shall consider alternate means of collection and trthe
proposed driveway.
7.According to Section 5.3.7 Feasibility/Limitations of the NYSSMDM, the total contributing
drainage area to a single rain garden shall be equal to or less than 1,000 SF. If treatment of
larger drainage areas is intended, then the practice shall incor
bioretention facilities. As such, the Applicant shall revise the rain gardens to include
required depths of mulch, planting soil, and gravel, to provide adequate filtering capacity within
the practices.
8.Rain gardens may be subject to sedimentation and invasive plant
maintenance problems overtime. As such, it is recommended that t
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Town of Queensbury
Site Plan 27-2012 John and Pamela Cembrook
May 10, 2012
Page 3
educated regarding the purpose and maintenance requirements of the rain
proper function is maintained.
9.The NYSDEC recommends that rain gardens have a maximum ponding depth of 6 inches,
(according to Section 5.3.7 of the NYSSMDM). However, rain garden P8 has a ponding depth of
9 inches before exiting the overflow weir. The Applicant shall c
plantings have been carefully selected to ensure survivability u
conditions.
10.The Applicant is proposing a new garage with a slightly larger footprint, at the same elevation
and approximate location of the existing garage. The grading provided depicts an existing knoll
to the east of this structure, which will need to be cut back to
footprint. However, no proposed grading information is provided.
plan to depict additional grading to demonstrate how runoff will
structure. If necessary, the post-construction subcatchment mapping shall be revised to reflect
any grading adjustments.
11.The environmental control plan depicts three temporary sediment
of the site. It is recommended that the Applicant add additional
areas draining south & east. In addition, the Applicant shall indicate specific s
provided within each basin to verify that sizing is in conformat
Specifications for Erosion & Sediment Control.
12.In accordance with the NYSSSESC, sizing of the apron for riprap outlet protection shall be
determined based upon the size of the outlet, the flow rate, and
It is unclear from the information provided how the typical apro
Please provide additional information to ensure that apron sizing confoto the requirements
of the NYSSSESC.
13.The proposed development may occur within the Federal Emergency Management Agency
(FEMA) published 100-year flood plain of Glen Lake. The applicant shall determine if the
development occurs within the flood plain and shall coordinate with the Town Code
Enforcement officer as it relates to meeting minimum code requirrelating to developing
within said floodplain.
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Town of Queensbury
Site Plan 27-2012 John and Pamela Cembrook
May 10, 2012
Page 4
Conclusions and Recommendations
It is our opinion that the applicant should provide clarification for the above it
changes in subsequent plan submissions.
If you have any questions regarding the above, please do not hes-1926.
Sincerely,
Sean M. Doty, P.E., LEED AP
Senior Project Engineer
cc: Pam Whiting, Town Planning Office Administrator (via email)
Keith Oborne, Town Planner (via email)
Joel Bianchi, P.E., Senior Director - Municipal Engineering (via email)
File
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