Kensington Estates_Stormwater PermitSTORMWATER MANAGEMENT PERMIT
APPLICATION DECISION
City of Northampton
Department of Public Works
Project I Site Name: Kensington Estates
Project Street or Location I Assessor ID: Westhampton Rd & Glendale Rd/ Map 41, Parcel 32
Applicant Name: Glendale 66 Corporation
Applicant Address/Phone: 118-21 Queens Blvd, Suite 316, Forest Hills, NY 11375 / 718-793-7928
OwnerName:~J=P=S~T~L=L=C==-------~-----~-----------~
Owner Address/Phone: 118-21 Queens Blvd, Suite 316, Forest Hills, NY 113751718-793-7928
Application Submission Date:-=3'"'-/l=l'"'"/=20=1=1=--------------------
THE FOLLOWING ACTION BY THE NORTHAMPTON DEPARTMENT OF PUBLIC
WORKS HAS BEEN TAKEN ON THIS APPLICATION BASED ON INFORMATION
PRESENTED:
Disapproval of the Stormwater Management Permit Application based on a
determination within seven days of the receipt of the application that the
application is administratively incomplete (see attached documentation).
__ Approval of the Storm water Management Permit Application.
__x_ Approval of the Storm water Management Permit Application subject to any
conditions, modifications or restrictions required by the Department of
Public Works (see below)
__ Disapproval of the Stormwater Management Permit Application based upon
a determination that the proposed plan, as submitted, does not meet the
purposes set forth in the Northampton Stormwater Management.
Standard Permit Conditions:
1. All clearing, grading, drainage, construction, and development shall be conducted in
strict accordance with the following plans and information submitted with the application
and as amended by any conditions attached to this permit:
a. Kensington Estates, Definitive Subdivision Plans, Sheet E-1 dated 5/25/2011,
Sheets Pl-PS dated 2/20/2012, Sheets 01, Sl, Dl, D3, D4, DS, Ll dated
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3/30/2012, and Sheets Rl, R2, Ul, D2 dated 5/1/2012, stamped by Mark B.
Darnold, P.E., The Berkshire Design Group, Inc.
b. Stormwater Drainage Report, Kensington Estates, Northampton, MA, Revised
May 25, 2011, prepared by The Berkshire Design Group, Inc.
c. Groundwater Mounding Report, Kensington Estates, dated June 2011, Prepared
by The Berkshire Design Group, Inc.
d. HydroCAD Analysis of Overland Flow from Level Lip Spreader 1 and 2, dated
11/29/2011, Prepared by The Berkshire Design Group, Inc.
e. Massachusetts DEP Checklist for Stormwater Report, Kensington Estates, dated
4/4/2012, stamped by Mark B. Darnold, P.E., The Berkshire Design Group, Inc.
f. Revised HydroCAD Drainage Calculations for Kensington Estates, dated
5/1/2012, The Berkshire Design Group, Inc.
2. The Northampton Department of Public Works (DPW) or its authorized representative
shall be provided access to the property to conduct inspections before, during, and after
construction activities as necessary. The applicant shall arrange with the DPW to
schedule the following inspections: Initial Inspection, Erosion Control Inspection, Bury
Inspection, and Final Inspection. The DPW may also conduct random inspections to
ensure effective control of erosion and sedimentation during all phases of construction.
3. At the completion of the work, including construction of stormwater management
facilities and landscaping, the applicant shall submit to the DPW as-built plans stamped
by a professional engineer of record in the Commonwealth of Massachusetts and a
statement from a professional engineer of record in the Commonwealth of Massachusetts
certifying that the materials and construction of the stormwater management system was
constructed in accordance with the approved plans and will function as designed. All
changes to the approved stormwater facilities shall be documented by a professional
engineer of record in the Commonwealth of Massachusetts and approved by the DPW
prior to submission of as-built plans and the certification statement described above.
4. Annual Reports that are stamped by a Registered Professional Engineer documenting
the actions completed as required by the Operation, Maintenance and Inspection
Agreement shall be submitted to the Northampton Department of Public Works by
October 1st of each year (see Specific Condition 1 below).
5. If construction of the proposed stormwater system has not started within five years of the
issue date of this permit, then the permit will expire and a new permit will be required.
Construction is defined as clearing, grading, excavation, filling, and installation of
drainage structures on the lots specified in this permit.
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Specific Permit Conditions:
1. Prior to issuance of a Building Permit, the applicant shall record an executed Stormwater
Operation, Maintenance, and Inspection Agreement that is binding on all subsequent
owners of land served by the private stormwater management facility by recording it in
the land records of the Registry of Deeds. The maintenance schedule and responsibility
for maintenance of all components of the proposed stormwater management system must
be adequately specified in Attachment A to this Agreement. The draft Proposed
Stormwater Management System Operation & Maintenance Plan for Post-Construction
submitted as part of the Stormwater Drainage Report referenced above must be revised to
the satisfaction of the Northampton DPW including but not limited to the following
items: inspection and maintenance schedule for the level lip spreaders, the outlet control
structure in the Infiltration Basin, and the diversion swale and drop inlet, revision of
inspection and maintenance of the infiltration basin and infiltration trench to define at
what depth of sediment the basin must be cleaned out, define failure of the basin and
trench to function as designed and the procedures to correct the structures. The DPW can
provide additional guidance on required revisions to the maintenance schedule. The final
agreement shall be approved by the Northampton DPW and signed by the owner and the
Mayor of Northampton. The final agreement shall be recorded at the Registry of Deeds at
the owner's expense. Section 281-8 of the Northampton Stormwater Management
Ordinance provides additional guidance for the requirements of this agreement.
2. This project will be required to submit one or more Notice of Intent (NOI) to the U.S.
EPA for coverage under the NPDES Stormwater Construction General Permit. A copy of
the final NOI and Stormwater Pollution Prevention Plan (SWPPP) shall be submitted to
the Northampton DPW for approval prior to the start of construction and prior to issuance
of a building permit. The SWPPP for the project must include sediment and erosion
control to keep sediment out of the infiltration systems during all phases of construction
including construction of individual houses.
3. The Plans referenced above include the note, "NOT FOR CONSTRUCTION."
Construction plans and specifications shall be submitted to the DPW for approval prior to
the start of any construction. A summary of any revisions to the approved plans should be
submitted in writing.
4. The Plans referenced above do not include any proposed connections from the house lots
or roadway subdrains to the proposed stormwater system. The DPW requests that any
proposed additional connections to the stormwater system be designed and submitted for
approval by the DPW prior to or during construction of the roadway otherwise
connections will not be allowed by the DPW.
5. The Deep Observation Hole Log for Deep Hole Number lDB(W) includes the note:
Redox obs. around old root structure throughout. Soil horizon beneath C3 was observed
to be dry. Pockets of material similar to C3 were obs. in TP JDB(E) and 2DB but no
distinct horizon was observed. Redox. features appear to be the result of an isolated
perched water table. Also see TP #S5, Cl horizon. Recommend removing this horizon if
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area is used for infiltration.
Prior to or during construction of the Infiltration Basin and Infiltration Trench, a Certified
Soil Evaluator or Certified Professional Soil Scientist must confirm and submit in writing
to the DPW the estimated seasonal high groundwater elevation and extent of any
restrictive soils in the areas of both the Infiltration Basin and Infiltration Trench. During
construction of the infiltration structures, DPW also requests submittals from a
Professional Engineer documenting the removal of any restrictive soil layers and
confirmation that the infiltration structures will function according to the approved
design.
6. Prior to issuance of any form of occupancy permit for the first dwelling, the applicant
must provide drainage easements for all drainage structures on private lots that stipulates
ownership, specify responsibility for maintenance of these structures, and sets up
provisions for financial guarantees to maintain these structures. The DPW must review
and approve all proposed drainage easements prior to recording at the land records of the
Registry of Deeds.
7. The plans include the design of a diversion swale, berm and drop inlet to convey flow via
an 18 inch drain line from a wetland area on the north side of the site to a wetland area
and brook on the south side of the site. Responsibility for the inspection and maintenance
of the drainage structures mentioned above and maintenance of necessary flow paths as
well as other impacts to private property including wetland encroachment or inadvertent
drainage flows onto private lots shall be the responsibility of the owners of the private
drainage system and/or the property owners association and not the responsibility of the
City of Northampton.
8. The plans and specifications approved by this Permit include roadways and conceptual
impervious surface areas for site development. During Building Permit applications for
individual lots and buildings, the applicant must submit documentation to the
Northampton DPW of the proposed drainage and the proposed impervious surface
footprint of the site. If the overall size of the impervious surface footprint proposed for
each lot is greater than the area specified in the approved plans and drainage calculations
or if the drainage system is changed in a substantive way, the applicant shall be required
to request and receive approval by the DPW of an amendment to this Stormwater
Management Permit and document the amended changes with revised plans and drainage
calculations.
9. The proposed stormwater management system is designed to mitigate peak stormwater
flows. If, after construction of the proposed system, the system is found to increase
stormwater flows to adjacent properties or to the municipal storm drain system, the owner
shall redesign and reconstruct the drainage system to prevent any increased stormwater
flows to adjacent properties or the municipal storm drain system.
10. All infiltration basins, outlets, berms, level-lip spreaders and other non-piped components
of the proposed stormwater system shall be constructed as proposed and stabilized prior
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to receiving drainage flows from the proposed development. No construction phase
stormwater flows shall be discharged to the infiltration systems.
cc. Planning Board c/o Office of Planning and Development
Building Department
~ 110 lrz_ ~
Conservation Commission c/o Office of Planning and Development
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