039-041 23 Atwood SPR wSite 2017Hospitality North
Atwood Drive
Northampton, Massachusetts
Site Plan Review
Application Package
Prepared For: Atwood Drive, LLC
March 2017
File# MP-2017-0046 APPLICANT/CONTACT PERSON DEVELOPMENT ASSOCIATES ADDRESS/PHONE PO BOX 528 (413) 789-3720 PROPERTY LOCATION 23 ATWOOD DR MAP 39 PARCEL 061 001 ZONE THIS SECTION FOR OFFICIAL USE ONLY: PERMIT APPLICATION CHECKLIST ENCLOSED REQUIRED DATE ~ING FORM FILLED OUT ~ePaid ~ 30,(!)0 "' 2,!.SQ Building Permit Filled out Fee Paid . TypeofConstruction: ZPA-CONSTRUCTION OF 2 NEW BUILDINGS -ONE 66,000 SQ FT 3 STORY AND THE OTHER A 72,000SO FT 4 STORY ~ New Construction Non Structural interior renovations Addition to Existing Accessory_ Structure Building Plans Included: Owner/ Statement or License 3 sets of Plans / Plot Plan THE FOLLOWING ACTION HAS BEEN TAKEN ON THIS APPLICATION BASED ON INFORMATION PRE~ENTED: __ Approved _V_ .Additional permits required (see below) PLANNING BOARD PERMIT REQUIRED UNDER: § ________ _ Intermediate Project: Site Plan AND/OR ,Special Permit with Site Plan n, t.J ..,.a:,1Y-002C Major Project: Site Plan AND/OR t/ Special Permit with Site Plan .__.. ,A M:6,u D T v ZONING BOARD PERMIT REQUIRED UNDER: § _________ _ Finding, ____ _ Special Permit ____ _ Variance* -------____ Received & Recorded at Registry of Deeds Proof Enclosed ____ _ ___ Other Permits Required: Curb Cut from DPW ---____ Water Availability ____ Sewer Availability ___ Septic Approval Board of Health ____ Well Water Potability Board of Health Permit from Conservation Commission ---____ Permit from CB Architecture Committee Permit from Elm Street Commission ---~;µJ) 2-/2.~ Signature ot tluilding Official Date / I Note: Issuance of a Zoning permit does not relieve a applicant's burden to comply with all zoning requirements and obtain all required permits from Board of Health, Conservation Commission, Department of public works and other applicable permit granting authorities. " * Variances are granted only to those applicants who meet the strict standards of MGL 40A. Contact the Office of Planning & Development for more information.
CONTENTS
Table of Contents Tighe&Bond
i
Letter of Transmittal
Zoning Permit Decision
Online Application
Confirmation of Online Payment
Section 1 Introduction
Section 2 Project Description
Section 3 Site Plan Approval Requirements
3.1 Protection of Adjoining Premises .................................................... 3-1
3.2 Access and Traffic Impacts ........................................................... 3-1
3.3 Character of the Site .................................................................... 3-3
3.4 Municipal Resource Capacity ......................................................... 3-4
3.5 Special Regulations – Wetland Overlay District ................................ 3-4
3.6 Technical Performance Standards .................................................. 3-5
3.6.1 Curb Cuts ......................................................................... 3-5
3.6.2 Sidewalks ......................................................................... 3-5
3.6.3 Peak Flows ....................................................................... 3-6
Section 4 General Standards
Section 5 Regulatory Compliance
5.1 Massachusetts Wetlands Protection Act ............................................ 5-1
5.2 Other Permits ................................................................................... 5-1
5.2.1 NPDES Construction General Permit ...................................... 5-1
5.2.2 City of Northampton Permits ................................................ 5-1
5.2.3 Massachusetts Environmental Policy Act .................................. 5-1
Appendices
A Figures
B Permit Plans (Under Separate Cover)
C Traffic Impact Statement
D Stormwater Report (Less Appendices)
SECTION 1
Tighe&Bond
1-1
Section 1
Introduction
On behalf of Atwood Drive LLC (the “Applicant”), Tighe & Bond is submitting an
application for Site Plan Review Approval for a major project to the City of Northampton
Planning Board.
The proposed Project includes construction of two new office buildings located to the
north of Atwood Drive (the Site). Major Project Site Plan Approval is required because
the project will result in an increase of gross floor area in excess of 5,000 square feet.
Tighe & Bond previously filed a Major Site Plan Review / Special Permit Application for
the site in 2013. The 2013 project included a renovation of the Clarion Hotel and
Conference Center, and proposed 45,000 s.f. of General Office space, 37,000 s.f. of
Medical Office space, and a 4,000 s.f. restaurant. In the revised site design, the Medical
Office and the Restaurant uses were eliminated and replaced with 138,000 square feet
of General Office space.
A USGS Site Locus figure, Priority Resource figure, and orthophotographs of the Project
site are provided in Appendix A as Figures 1-4 (respectively). Project plans are provided
in Appendix B.
SECTION 2
Section 2 Project Description Tighe&Bond
Hospitality North Major Project Site Plan Approval Application ii
Section 2
Project Description
The proposed project, Hospitality North, includes the construction of two new buildings
on a 7.8-acre site to the north of Atwood Drive (the Site). The Site is comprised of two
parcels (Parcel IDs 39-041-001, and 39-043-001) owned by Atwood Drive LLC and was
the site of the former Clarion Hotel and Conference Center which was demolished in
August 2016. The Site Locus Map, Figure 1, provided in Appendix A, shows the Site and
surrounding features including the proximity to Mt. Tom Road (State Route 5) and
Interstate 91.
The building proposed on the easterly portion of the site (closer to Route 5) is a three-
story building with a 22,000 square foot footprint and 66,000 square feet of gross floor
area. The second building, on the westerly portion of the site (set further back from
Route 5), will be a four-story building with a 18,000 square foot footprint and 72,000
square feet of gross floor area.
The proposed site is located within the General Business zoning district and the
Wetlands Protection Overlay District. The property, under existing conditions, is
previously developed urban land. Land surrounding the Site is occupied by medical and
general office uses, active farmland, land under a conservation restriction, Interstate 91,
and Route 5. A portion of the site is below the 100-yr flood elevation. The proposed
project use includes general offices, but specific tenants have not yet been identified.
The City of Northampton zoning regulations allow the office uses by right in the General
Business zoning district. However, the project will result in an increase of gross floor
area in excess of 5,000 square feet, thus requiring a Site Plan Approval as a Major
Project.
The project will impact buffer zone to bordering vegetated wetlands, in addition to work
within the 100-year flood plain, as defined in 310 CMR 10 Wetlands Protection, and the
filing of a Request for an Amended Order of Conditions with the Northampton
Conservation Commission will be required. The project obtained an Order of Conditions
in November 2013 which has been extended until November 2019.
This document was prepared to address the requirements of Site Plan Approval in
narrative. Additional requirements of the permit application for Site Plan Review for a
Major Project are provided in the Appendices located at the end of this report.
SECTION 3
Tighe&Bond
Hospitality North Major Project Site Plan Approval Application 3-1
Section 3
Site Plan Approval Requirements
This section of the narrative addresses how the proposed project will comply with the
requirements specified in the Northampton Site Plan Approval Ordinance.
3.1 Protection of Adjoining Premises
Northampton Site Plan Approval Ordinance (§350–11.6-A): The requested use
protects adjoining premises against seriously detrimental uses. If applicable,
this shall include provision for surface water drainage, sound and sight buffers
and preservation of views, light, and air;
Several measures have been taken into account within the Site design to protect
adjoining premises. The stormwater management design is completed and is being
reviewed concurrently with the Northampton Department of Public Works. The peak
rate of flow onto adjoining parcels under proposed conditions does not exceed the
existing conditions. Therefore, there is no offsite impact due to the increase of
impervious surface and altered grading on the Site. Refer to the Stormwater Report
attached with this submission for detailed calculations of existing and proposed site
hydrology. The narrative of the Stormwater Report (without appendices) is included in
Appendix D of this document.
Since the adjoining parcels south of Atwood Drive are of similar uses to those proposed
(i.e. general and medical office), the concern for noise and sight impacts is nominal.
However, the project design includes vegetation and plantings as well as a suitable
building-type for the character of the area. Additionally, Interstate 91 and the Exit 18
Interchange abut the site to the west and north and diminish the impacts further.
The new lighting fixtures on the site will be evenly distributed throughout the Site and
positioned such that “spill” will not extend beyond the property boundaries of the site.
Lighting fixtures will be selected to eliminate glare and uplighting. The attached
Permitting Plans (Appendix B) show the locations of the proposed light poles on the site
(Sheet SL-1, Photometric Plan). Site lighting has been designed to minimize light at the
property lines, as shown in the Photometric Plan. Please see the Permitting Plans
attached for details of the measures taken to protect the adjoining premises from glare
and up-lighting.
3.2 Access and Traffic Impacts
Northampton Site Plan Approval Ordinance (§350–11.6-B): The requested use
will promote the convenience and safety of vehicular and pedestrian movement
within the site and on adjacent streets, minimize traffic impacts on the streets
and roads in the area. If applicable, this shall include considering the location
of driveway openings in relation to traffic and adjacent streets, access by
emergency vehicles, the arrangement of parking and loading spaces, and
provisions for persons with disabilities.
A Traffic Impact Study (provided in Appendix C) was developed as part of the 2013
submission. The Study evaluated potential traffic impacts resulting from the
redevelopment of the Clarion Hotel and Conference Center. The study was based on an
Section 3 Site Plan Approval Requirements Tighe&Bond
Hospitality North Major Project Site Plan Approval Application 3-2
earlier site configuration that included 45,000 s.f. of General Office space, 37,000 s.f. of
Medical Office space, and a 4,000 s.f. restaurant. In the revised site design, the Medical
Office and the Restaurant uses were eliminated and replaced with 138,000 square feet
of General Office space.
The 2013 Traffic Impact Study was based on a conservative methodology using higher
growth rates and trip counts than historic trends suggest is likely at the site. Based on a
revised analysis, trip counts are reduced under the new site design from 246 to 243 for
the AM Peak, from 314 to 233 for the PM Peak, and from 2,341 to 1,710 for the Daily
total. Although a signalized intersection is still warranted at the intersection of Atwood
Drive & Mount Tom Road, the reduced trip counts make the original study slightly more
conservative, but still accurate.
The future site trip-generation volumes were developed using the Institute of
Transportation Engineers (ITE) Trip Generation, 9th Edition, with the land use code (LUC)
710 for General Office Building. Total trip generation is shown in Table 1. The directional
distribution of the site generated trips (to and from) is based on existing traffic patterns.
Trip Generation
TABLE 1
Hospitality North – Weekday Trip Generation
Land Use AM Peak Hour PM Peak Hour Daily
138,000 SF Office In 214 40 855
Out 29 193 855
Total 243 233 1,710
The proposed development is estimated to generate a total of 243 vehicle trips (214
entering trips and 29 exiting trips) during the weekday morning peak hour and a total of
233 vehicle trips (40 entering trips and 193 exiting trips) during the weekday afternoon
peak hour. The daily trip generation is estimated to be 1,710 vehicle trips.
Please refer to the 2013 Traffic Impact Statement in Appendix C for a comprehensive
analysis of the vehicular movements on adjacent streets. Also, please note that the daily
trip generation estimated for the proposed project is less than the number approved
previously for the site (2,341 vehicle trips) during review of the 2013 Site Plan Review /
Special Permit Application.
The proposed development will be accessed by a full-access driveway along Atwood
Drive. The proposed driveways are 22 feet in width and will accommodate pedestrian
crossings with painted crosswalks. The location of the driveway provides direct vehicular
access to the proposed office buildings and has been located to coordinate with access
drives for the medical and general office development across Atwood Drive.
A 6-foot wide sidewalk is proposed along the entirety of the property, located along the
north side of Atwood Drive. Pedestrian access is provided to the proposed office
buildings. Wheelchair ramps and crosswalks are provided at all sidewalk/driveway
Section 3 Site Plan Approval Requirements Tighe&Bond
Hospitality North Major Project Site Plan Approval Application 3-3
locations. Crosswalks and painted pedestrian ways are provided through the main
parking area.
The City of Northampton Zoning Ordinance indicates that parking spaces shall be
provided as indicated in the following matrix:
Building Proposed
Use Requirement Required
Spaces
Provided
Spaces
Office
Building #1
General
Office
1 space per 300 gross square
feet 220
Office
Building #2
General
Office
1 space per 300 gross square
feet 240
Total 460 448
The Planning Board may allow reduced parking requirements in accordance with § 350-
8.6 (shared parking). Through Site Plan Approval, the Board has the discretion to reduce
parking requirements for major projects by up to 20%. The Applicant is proposing a
2.6% reduction in required parking spaces.
The site features a number of design elements that will promote bicycle and public
transit use (rather than automobile travel) to and from the site. Site amenities proposed
to encourage bicycle travel include a covered bike rack and employee showers located
within the proposed Office building. Additionally, the Applicant has previously worked
with the Pioneer Valley Transit Authority (PVTA) to incorporate Atwood Drive and the
proposed development to the local PVTA route. A bus stop has been provided along the
north side of Atwood Drive.
We assume that the proposed amenities will be acceptable to mitigate both the proposed
reduction in parking requirements in compliance with Northampton Site Plan Approval
Ordinance (§350–11.6-B(2)). Please refer to the Traffic Impact Study provided in
Appendix C for an analysis of the vehicular impact of the proposed developments.
3.3 Character of the Site
Northampton Site Plan Approval Ordinance (§350–11.6-C): The site will
function harmoniously in relation to other structures and open spaces to the
natural landscape, existing buildings and other community assets in the area as
it relates to landscaping, drainage, sight lines, building orientation, massing,
egress, and setbacks. Rear and/or side wall facades within 50 feet of a
completed or planned section of a cycle track or bike path shall have features
that invite pedestrian access from that side of the building.
The proposed buildings will mirror the architectural features of the existing adjacent
Atwood buildings.
Landscape plans, prepared by Tighe & Bond, are also included in Appendix B. These
plans have been included in the Site Plan Review package for review of the vegetation
and planting plans. Project landscaping will balance the new development with the
Section 3 Site Plan Approval Requirements Tighe&Bond
Hospitality North Major Project Site Plan Approval Application 3-4
natural undeveloped portions of the site by using native and adaptive plantings. Open
space is retained along the western portion of the Site. Landscaped buffer strips are
provided along the length of Atwood Drive.
There will not be any storage, service areas, or other unsightly uses in view from
neighboring properties.
3.4 Municipal Resource Capacity
Northampton Site Plan Approval Ordinance (§350–11.6-D): The requested use
will not overload, and will mitigate adverse impacts on, the City's resources
including the effect on the City's water supply and distribution system, sanitary
and storm sewage collection and treatment systems, fire protection, streets
and schools.
During the engineering design, the capacity of municipal and infrastructural resources
was studied. The 8” water line in Atwood Drive served the former Clarion Hotel and
serves the office building south of Atwood Drive. The estimated water use on-site is
26,690 gallons per day (GPD). It is anticipated that the 8” water line was designed for
and can provide for this demand. Three fire hydrants exist along the length of the Site.
Refer to Sheet C-500, Utility Plan, in the Permitting Plans for location of existing and
proposed utilities.
Estimated wastewater generation is the same as water use, 24,020 GPD. There is a 12”
municipal gravity sewer within Atwood Drive. The gravity sewer flows northwest in
Atwood Drive to a wastewater pump station. Collected wastewater is pumped through a
10” force main to a gravity main in Route 5. Based on discussions with the Northampton
DPW, and historic operational data, the existing pump station has sufficient capacity to
handle the additional flows associated with this proposed project.
The majority of the stormwater will be managed on-site. Existing connections to the
municipal storm drainage infrastructure in Atwood Drive will be removed and new
connections established to convey stormwater from the southern portions of the project
to the discharge location to the west. As noted in Section 2, stormwater discharge does
not exceed the peak rate and peak elevations of the discharge in the existing conditions.
Snow removal will be managed by the Site Owner. Snow will be stored on-site as space
allows and excess snow will be removed from the Atwood Drive area and disposed of in
accordance with the Massachusetts Department of Environmental Protection (DEP) snow
removal guidelines. At no time will snow disposal be allowed in the bioretention areas
nor the detention basins on site.
3.5 Special Regulations – Wetland Overlay District
Northampton Site Plan Approval Ordinance (§350–11.6-E): The requested use
meets any special regulations set forth in this chapter.
Section 3.5 of this report addresses special regulations that are applicable to the Site
due to zoning. Since the Site is in the Wetland Overlay District, the development was
designed to meet the standards in §350–14.
Section 3 Site Plan Approval Requirements Tighe&Bond
Hospitality North Major Project Site Plan Approval Application 3-5
The Wetland Overlay District was created primarily to “preserve and protect the streams
and other watercourses in the City of Northampton and their adjoining land; to protect
the health and safety of persons and property against the hazards of flooding and
contamination; [and] to preserve and maintain the groundwater table”.
The following measures were taken to meet the purpose of the Wetland Overlay District.
The finish floor elevations of the buildings are at or above the 100-year floodplain
elevation (see Site Layout Plan in the Permitting Plans). Foundation design will include
measures to prevent flotation of the buildings, or lateral movement during flooding. No
materials will be stored in locations that have a risk of water contamination during a
flooding event. The site has been graded to increase the flood storage volume at every
elevation (in one-foot increments). Please refer to the Grading and Drainage Plan,
Sheet 7 in the Permitting Plans for detailed design.
The two proposed buildings will be serviced from the existing 8” water line in Atwood
Drive. Standard backflow devices will be included to protect the water system from
backflow in the case of flooding and the water system will be designed in accordance
with §290, Subdivision of Land, in the Northampton Ordinances as recommended in the
Site Plan Approval criteria. Sewage will be conveyed into the existing municipal sewer
system, which is a separate sewer not connected to the drainage system and therefore,
floodwaters will not have any significant entrance to this system. All piping installed to
carry wastewater will be ductile iron, as required by §290 for Wetland Districts. Other
utilities will be located with sufficient ground cover to protect them from active flood
waters. Refer to Sheet C-500, Site Utility Plan, in the Permitting Plans for approximate
locations of proposed utilities.
The trash enclosures are the only accessory structures proposed and are designed with a
concrete slab foundation. Trash structures are included on the Site Layout Plan and in
the Details section of the Permitting Plans. Refuse and other wastes will be removed
from the site on a regular basis.
3.6 Technical Performance Standards
3.6.1 Curb Cuts
Northampton Site Plan Approval Ordinance (§350–11.6-F(1)): Curb cuts onto
streets shall be minimized. Access to businesses shall use common driveways,
existing side streets, or loop service roads shared by adjacent lots when
possible. More than one curb cut shall be permitted only when necessary to
minimize traffic and safety impacts.
The proposed uses will be accessed by one common drive-way from Atwood Drive. The
location of the driveway provides direct vehicular access to the proposed office buildings
and has been located to coordinate with existing access drives for the medical and
general office development across Atwood Drive.
3.6.2 Sidewalks
Northampton Site Plan Approval Ordinance (§350–11.6-F(2)): Pedestrian,
bicycle and vehicular traffic movement on site must be separated, to the extent
possible, and sidewalks must be provided between businesses within a
development and from public sidewalks, cycle tracks and bike paths. All
projects shall include sidewalks and tree belts abutting the street, except
Section 3 Site Plan Approval Requirements Tighe&Bond
Hospitality North Major Project Site Plan Approval Application 3-6
where site topography or other limitations make them infeasible. In such cases
where the sidewalk is infeasible, the developer shall install an equal number of
feet of sidewalk and/or tree belt in another area of the community as deemed
by the Planning Board or Office of Planning and Sustainability.
A 6-foot wide sidewalk is proposed along the entirety of the property, located along the
north side of Atwood Drive. Wheelchair ramps and crosswalks are provided at all
sidewalk/driveway locations.
The proposed development will accommodate pedestrian crossings with painted
crosswalks throughout. Open space will be retained along the western portion of the Site
and landscaped buffer strips are provided along the length of Atwood Drive as shown on
the Landscape plans included in the Site Plan Review package.
3.6.3 Peak Flows
Northampton Site Plan Approval Ordinance (§350–11.6-F(3)): Major projects,
except in the Central Business District, must be designed so there is no
increase in peak flows from the one- or two- and ten-year Soil Conservation
Service design storm from predevelopment conditions (the condition at the
time a site plan approval is requested). Green infrastructure and low-impact
design shall be incorporated to the extent feasible to ensure runoff is handled
on site. At the very minimum, the runoff from up to a one-inch rain storm (first
flush) shall be detained on site for an average of six hours. These requirements
shall not apply if the project will discharge into a City storm drain system that
the Planning Board finds can accommodate the expected discharge with no
adverse impacts. In addition, catch basins shall incorporate sumps of a
minimum of four feet and, if they will remain privately owned, a gas trap.
The proposed project will not substantially alter the existing stormwater flow paths at
the site through use of infiltration and detention. Runoff is collected by grassed swales
and deep-sump, hooded catch basins located within the parking areas and conveyed to
the infiltration basins or bioretention areas where runoff is detained prior to discharge.
Please refer to the Stormwater Report in Appendix D for more information.
SECTION 4
Section 4 General Standards Tighe&Bond
Hospitality North Major Project Site Plan Approval Application 4-1
Section 4
General Standards
Northampton Zoning Ordinance §350–12.1: Any use permitted by right, by
special permit, or by special exception in any district shall not be conducted in
a manner as to emit any dangerous, noxious, injurious, or otherwise
objectionable fire, explosion, radioactivity or other hazard; noise or vibration;
smoke, dust, odor or other form of environmental pollution; electrical or other
disturbance; glare, liquid or solid refuse or wastes; conditions conducive to the
breeding of insects, rodents, or other substance, conditions or element in an
amount as to affect adversely the surrounding environment.
The General Standards (§350–12.1) are met due to the nature of the site use (general
office) throughout the development. The use types are not typically associated with
rodents, insects, emissions, odors and noises. Refuse areas are indicated on the site
plans and are to be located within appropriate containers and fencing. Furthermore,
there will be no sanitary waste discharges from the buildings other than into the
municipal sewer system. The proposed infiltration basin and bioretention areas are not
designed to hold standing water longer than 72 hours, as required in the Massachusetts
Stormwater Standards, thus reducing any mosquito impact from the development.
SECTION 5
Section 5 Regulatory Compliance Tighe&Bond
Hospitality North Major Project Site Plan Approval Application 5-1
Section 5
Regulatory Compliance
5.1 Massachusetts Wetlands Protection Act
As shown on Sheets C-200 through C-500 in Appendix B, a portion of the proposed work
will occur within buffer zone to bordering vegetated wetlands, subject to protection
pursuant to the MA Wetlands Protection Act (M.G.L. c. 131, Section 40), and
construction activities will also impact 100-year flood plain and bordering land subject to
flooding (BLSF). A Request for an Amended Order of Conditions will be submitted to the
Northampton Conservation Commission.
5.2 Other Permits
5.2.1 NPDES Construction General Permit
The Environmental Protection Agency (EPA) issues National Pollutant Discharge
Elimination System (NPDES) General Construction Permits (CGP) in an effort to minimize
detrimental runoff caused by the clearing, grading, and excavating or general
construction activities on construction sites. Since the land disturbance will exceed the
CGP impact threshold of more than one acre of land, a NPDES CGP permit is required.
Prior to construction, a CGP permit will be obtained and a Stormwater Pollution
Prevention Plan (SWPPP) will be submitted to the EPA.
5.2.2 City of Northampton Permits
The following local permits will be obtained from the City of Northampton:
Amended Order of Conditions
Stormwater Permit
Building permit
Electrical permit
Please note that the 2013 package included a Special Permit Application in addition to
Site Plan Review as the hotel use proposed at the time would have required a Special
Permit from the Planning Board. The zoning regulations allow the currently proposed
office uses by right in the General Business zoning district and the Special Permit is no
longer required.
5.2.3 Massachusetts Environmental Policy Act
In 2013, an Environmental Notification Form was submitted to the Massachusetts
Environmental Policy Act (MEPA) Office for the project.
The 2013 project was subject to environmental review pursuant to Section 11.01.2.a of
the MEPA regulations as it required financial assistance from the Commonwealth and a
State Agency action (i.e. a permit).
Section 5 Regulatory Compliance Tighe&Bond
Hospitality North Major Project Site Plan Approval Application 5-2
The project met the following ENF review thresholds:
301 CMR 11.03.3.b.1.e, because it would have resulted in the expansion of fill in
a regulatory floodway.
301 CMR 11.03.6.b.14, as it involved generation of 1,000 or more new adt on
roadways providing access to a single location and construction of 150 or more
new parking spaces at a single location.
Due to the fact that project impacts have decreased from the impacts approved by MEPA
in 2013, no further environmental review is required. No mandatory EIR thresholds were
triggered by the proposed 2013 project, or the project currently proposed.
J:\H\H1363\Atwood North\Permits\2016\Site Plan-Special Permit\Major SPR Narrative.doc
APPENDIX A
Based on USGS Topographic Map forEasthampton, MA Quadrangles. Revised 1979.Circles indicate 500-foot and half-mile radii
0 1,000 2,000
Feet
1:24,000
V:\Projects\H\H1363\Figures_20170324\ClarionHotel_Topo.mxd
FIGURE 1SITE LOCATION
Hospitality North23 Atwood DriveNorthampton, Massachusetts
March 2017
H-1363
^_
¹Tighe&Bond
Engineers | Environmental Specialists ÈSITE LOCATION
§¨¦91
UV5
RAMP-RT 91 NB TO RT 5
ATWOOD DRIVE MOUNT TOM ROADRAMP-RT 5 (MOUNT TOM RD) TO RT 91 SBRAMP-RT 5 TO RT 91 NBINTERSTATE 910 100 200
Feet
V:\Projects\H\H1363\Figures_20170324\ClarionHotel_Resource.mxd
Data source: Office of Geographic Information(MassGIS), Commonwealth of Massachusetts, MassIT)Executive Office of Environmental Affairs.Circles indicate 500-foot and half-mile radii.Data valid as of March 2017.
FIGURE 2PRIORITY RESOURCESHospitality North23 Atwood DriveNorthampton, Massachusetts
H-1363
March 2017
^_
Le ge n dXNHESP Certified Vernal PoolsXNHESP Potential Vernal Pools
#Non-Landfill Solid Waste Sites
!Þ Community Public Water Supply - Surface Water
!Þ Community Public Water Supply - Groundwater
"Non-Community Non-Transient Public Water Supply
"T Non-Community Transient Public Water Supply
Limited Access Highway
Multi-Lane Highway, NOT Limited Access
Other Numbered Highway
Major Road - Collector
Minor Street or Road
Aquaducts
Hydrologic Connections
!Powerline
Pipeline
Track or Trail
Trains
Stream/Intermittent Stream
Public Surface Water Supply Protection Area (Zone A)
DEP Approved Wellhead Protection Area (Zone I)
DEP Approved Wellhead Protection Area (Zone II)
DEP Interim Wellhead Protection Area (IWPA)
Protected and Recreational Open Space
Solid Waste Landfill
Area of Critical Environmental Concern (ACEC)
NHESP Priority Habitats for Rare Species
NHESP Estimated Habitats for Rare Wildlife
EPA Designated Sole Source Aquifer
Major Drainage Basin
Sub Drainage Basin
Inland Wetlands
Coastal Wetlands
Public Surface Water Supply (PSWS)
Water Bodies
Non-Potential Drinking Water Source Area - High Yield
Non-Potential Drinking Water Source Area - Medium Yield
Potentially Productive Medium Yield Aquifer
Potentially Productive High Yield Aquifer
County Boundary
Town Boundary
USGS Quadrangle Sheet Boundary
1:2,400 ¹Tighe&BondEngineers | Environmental SpecialistsÈSITE LOCATION
MOUNTTOMROADRAMP-RT 91 NBTORT 5INTERSTATE 91ATWOOD DRIVERAMP-RT5(MOUNTTOMRD)TORT91SBRAMP-RT5 TO RT 9 1 N B
UV5
§¨¦91
FIGURE 3ORTHOPHOTOGRAPHHospitality North23 Atwood DriveNorthampton, Massachusetts¹0 100 200
Feet
1:2,400
V:\Projects\H\H1363\Figures_20170324\ClarionHotel_Ortho.mxd
Based on MassGIS Color Orthophotography (2013).
H-1363
March 2017
^_
Legend
Town Boundary
Tighe&Bond
Engineers | Environmental Specialists ÈSITE LOCATION
APPENDIX B
APPENDIX C
Hospitality North
Northampton, MA
Traffic Impact Study
Prepared For:
Atwood Partners, LLC
September 11, 2013
Table of Contents Tighe&Bond
i
1 Introduction
2 Existing Conditions
2.1 Mount Tom Road (US Route 5) ....................................................... 2-1
2.2 Atwood Drive ............................................................................... 2-1
2.3 Conz Street ................................................................................. 2-1
2.4 Traffic Volumes ............................................................................ 2-1
2.5 Crash Analysis ............................................................................. 2-2
3 No Build Conditions
3.1 Traffic Growth .............................................................................. 3-1
3.2 Planned Roadway Improvements .................................................... 3-1
3.3 Traffic Volumes ............................................................................ 3-2
4 Build Conditions
4.1 Trip Generation ............................................................................ 4-1
4.2 Traffic Volumes ............................................................................ 4-2
5 Mitigation
5.1 Traffic Signal Installation ............................................................... 5-1
5.2 Traffic Signal Coordination System .................................................. 5-2
6 Level of Service (LOS)
6.1 Existing Conditions ....................................................................... 6-1
6.2 2018 No Build .............................................................................. 6-2
6.3 2018 Build Mitigated ..................................................................... 6-2
7 Conclusion
J:\H\H1363\Traffic\Mix Use Site\Report\Sept 2013\Clarion Redevelopment Report_rev.doc
Appendices
A Figures
B Trip Generation Worksheets
C Level of Service (LOS) Analysis
D Traffic Signal Warrant Analysis
Tighe&Bond
Clarion Hotel Redevelopment Traffic Impact Study 1-1
Section 1
Introduction
Tighe & Bond has evaluated the potential traffic impacts resulting from the
redevelopment of the Clarion Hotel and Conference Center located at 1 Atwood Drive in
Northampton, Massachusetts. The proposed project is seeking to redevelop the existing
hotel property, approximately 7.8 acres, with 45,000 square feet of general office space,
35,000 square feet of medical office space, a 4,000 square foot quality restaurant, and a
hotel redevelopment from 127 rooms to 107 rooms.
Tighe&Bond
Clarion Hotel Redevelopment Traffic Impact Study 2-1
Section 2
Existing Conditions
An inventory of the adjacent roadway network was conducted in June 2013. The
inventory included collection of existing roadway geometrics and traffic volumes for the
roadways and intersections near the site. Figure 1 depicts an aerial view of study area
in relation to the site.
2.1 Mount Tom Road (US Route 5)
In the vicinity of the site, Mount Tom Road (US Route 5) is classified as an Urban Minor
Arterial roadway and is under Massachusetts Department of Transportation (MassDOT)
jurisdiction. The roadway pavement width is approximately 45 feet and generally
provides two travel lanes, one in each direction, at approximately 12 feet in width. In
the vicinity of the site, the posted speed limit is 40 miles per hour (mph) for both
directions and there are no sidewalk facilities or dedicated bicycle facilities. Based on
Automated Traffic Recorder (ATR) counts conducted for the Conz Street/ Route 5
Roundabout MassDOT project, Route 5 south of Conz Street has an average daily traffic
(ADT) of 20,224 vehicles per day.1
2.2 Atwood Drive
Atwood Drive is classified as a Local Road by MassDOT and the roadway has a pavement
width of approximately 48 feet near the intersection with Mount Tom Road. Atwood
Drive provides access to the existing Northwood Development and Clarion Hotel and
Conference Center. Atwood Drive is a dead-end roadway that is approximately 900 feet
in length.
2.3 Conz Street
Conz Street is classified as an Urban Minor Arterial roadway by MassDOT and the
roadway has a pavement width of approximately 30 feet northwest of its intersection
with Mount Tom Road. Conz Street provides an alternate connection to Route 5 to the
Main Street downtown Northampton area. Traffic counts conducted for the Conz
Street/Route 5 Roundabout MassDOT project indicate that Conz Street has an ADT of
8,930 vehicles per day.
2.4 Traffic Volumes
Intersection vehicular turning movement data for the study area were obtained from two
sources: the Traffic Impact Study prepared for general and medical-dental office space
on Atwood Drive2 and from the Functional Design Report prepared for the Conz
Street/Route 5 MassDOT Roundabout Project. The intersection turning movements were
1 Nitsch Engineering. Functional Design Report – Pleasant Street (Route 5) & Conz Street,
Northampton, MA. no. 8126.02. July 2011.
2 Fuss & O’Neill, Inc. Traffic Impact Study – Site Development Atwood Drive, Northampton,
MA. no. 20091439.A10. 09 June 2010.
Section 2 No Build Conditions Tighe&Bond
Clarion Hotel Redevelopment Traffic Impact Study 2-2
historically increased by 1.0 percent per year to project the traffic volumes to the year
2013. The weekday morning and afternoon peak hour traffic volumes for the 2013
Existing Conditions are summarized in Figures 2 and 3, respectively.
2.5 Crash Analysis
MassDOT Crash Report data for the City of Northampton were reviewed for collisions
within the study intersections during the latest available three years of available data:
2008, 2009, and 2010. The study area crash data for the years 2008, 2009, and 2010
are provided in Appendix B. In addition to the collision summary, incident occurrence
should be compared to the volume of traffic through a particular intersection to
determine significance. Accordingly, the crash rates were calculated for each study area
intersection and compared with the district-wide (MassDOT District 2) averages. An
intersection crash rate is a measure of the frequency of collisions compared to the
volume of traffic through an intersection and is presented in crashes per million entering
vehicles (c/mev). For unsignalized intersections, the district-wide average is 0.68
c/mev. For signalized intersections, the district-wide average is 0.82 c/mev. A
comparison of the calculated crash rate to these averages can be used to establish the
significance of collision occurrence and whether or not potential safety problems exist.
Table 1 provides a summary of the recorded crashes.
Between the years of 2008 and 2010, the intersection of Conz Street and Route 5
(Pleasant Street/Mount Tom Road) was reported to have experienced an above average
crash rate (1.33 c/mev) in comparison to the MassDOT District 2 average rate of 0.68
for unsignalized intersections. The majority of the 36 recorded crashed were comprised
of angle crashes (31 percent) and rear-ends crashes (44 percent). Approximately 28
percent of the reported collisions resulted in personal injury. These data indicate that a
safety concern may exist. As described in the No-Build Conditions section of this traffic
study, MassDOT is developing improvement measures to be implemented at this location
to improve operations and increase safety.
The other study area intersections were found to be below the MassDOT District 2 crash
rates for signalized and unsignalized intersections. There were no fatalities reported at
any of the study area intersections during the time period evaluated.
Section 2 No Build Conditions Tighe&Bond
Clarion Hotel Redevelopment Traffic Impact Study 2-3
TABLE-1
MassDOT Crash Data -2008 to 2010
Atwood Drive and Mount Tom Road (Route 5)
I-91 Northbound Ramps and Mount Tom Road (Route 5)
I-91 Southbound Ramps and Mount Tom Road (Route 5)
Conz Street and Mount Tom Road/Pleasant
Street (Route 5)
YEAR 2008 1 2 2 11
2009 1 2 2 13
2010 0 2 2 12
Total 2 6 6 36
Average No. of Crashes 2 2 2 12
Crash Rate 0.15 0.27 0.22 1.33
District 2 Average 0.68 0.82 0.68 0.68
TYPE Angle 2 3 3 11
Rear-End 0 3 2 16
Head-On 0 0 0 0
Sideswipe 0 0 1 6
Unknown/Other 0 0 0 3
Total 2 6 6 36
SEVERITY Property Damage only 2 4 3 26
Non-fatal Injury 0 2 3 10
Fatality 0 0 0 0
Unknown/Other 0 0 0 0
Total 2 6 6 36
WEATHER Clear 1 3 3 16
Wet 0 1 2 6
Snow/Ice 0 0 0 2
Clouds 1 1 1 10
Fog 0 1 0 0
Unknown/Other 0 0 0 2
Total 2 6 6 36
Tighe&Bond
3-1
Section 3
No Build Conditions
To determine future traffic demands on the study area roadways, the 2013 Existing
Condition traffic volumes were projected to the year 2018 to reflect a 5-year future
condition in accordance with MassDOT and City of Northampton traffic impact
assessment guidelines. Traffic volumes on the roadway network would include existing
traffic, new traffic due to normal traffic growth, and traffic related to significant
development by others expected to be completed within the area by 2018.
Consideration of these factors resulted in the development of 2018 No Build Condition
traffic volumes, which assume the proposed development is not built.
3.1 Traffic Growth
The latest five years of available traffic-count data (2005 to 2009) from a nearby
MassDOT Count Station3 indicate that yearly average daily traffic (ADT) volumes have
decreased during this period. Although the MassDOT historical data indicate a decrease
in traffic volumes, Tighe & Bond has applied a conservative (worse than expected) 1.0
percent growth rate to account for general population growth and the traffic generated
by smaller area developments.
In addition, traffic to be generated by planned developments estimated to add
substantial volumes of traffic through the study area within the next five years was
considered. The planned Northwood Development on Atwood Drive was included in the
No-Build Conditions. This development has been approved for the construction of
39,360 gross square feet of General Office Building and 45,000 gross square feet of
Medical-Dental Office Building to be located on the south side of Atwood Drive west of
Mount Tom Road. According to discussions with the City of Northampton Planning and
Development Department, there are no other proposed developments in vicinity of the
project area that have submitted a traffic impact study.
3.2 Planned Roadway Improvements
Based on coordination efforts with local and state officials, traffic improvements are
anticipated to be constructed or under construction within the design horizon at three of
the project area intersections by MassDOT. The intersection improvements include the
following:
The intersection of Conz Street and Route 5 (Pleasant Street/Mount Tom Road) is
currently under design to be converted into a roundabout intersection to replace
the stop sign controlled intersection.
The intersection of Mount Tom Road with the I-91 southbound ramps is currently
under construction to replace the stop sign controlled operation with traffic signal
operation.
3 MassDOT 2009 Statewide Traffic Data Collection Section; Permanent Count Station 11
located on Routes 5 and 10 south of Hatfield Town Line.
Section 3 No Build Conditions Tighe&Bond
3-2
The intersection of Mount Tom Road with the I-91 northbound ramps is under
design to be widened to accommodate an additional eastbound left-turn lane
onto Mount Tom Road northbound.
3.3 Traffic Volumes
The addition of an annual growth rate, the traffic associated with the general and
medical-dental office space to be constructed on Atwood Drive, and future roadway
improvements on the study area roadways have been analyzed for 2018 No Build
Conditions. The weekday morning and afternoon peak-hour traffic volumes for the 2018
No Build Conditions are shown in Figures 4 and 5, respectively.
Tighe&Bond
Clarion Hotel Redevelopment Traffic Impact Study 4-1
Section 4
Build Conditions
As proposed, the existing Clarion Hotel and Conference Center will be redeveloped to
include 45,000 square feet of general office space, 35,000 square feet of medical office
space, a 4,000 square foot quality restaurant, and a reduction in hotel space from 127
rooms to 107 rooms.
4.1 Trip Generation
The future site trip-generation volumes were developed using the Institute of
Transportation Engineers (ITE) Trip Generation, 9th Edition, with the land use code (LUC)
710 for General Office Building, LUC 720 for Medical-Dental Office Building, and LUC 931
Quality Restaurant. Total trip generation is shown in Table 2.
The proposed General Office Building (LUC 710) trip generation was calculated using a
proposed maximum build-out development size of 45,000 square feet. The proposed
Medical-Dental Office Building (LUC 720) trip generation was calculated for a maximum
build-out size of 35,000 square feet. The proposed Quality Restaurant (LUC 931) trip
generation was calculated based on a 4,000 square foot building size.
The proposed Clarion Hotel room count will be 107 rooms, a decrease of twenty rooms
from what exists under current conditions. Given that the proposed hotel will have
fewer rooms under the proposed build conditions resulting in a small decrease in traffic
volumes during the peak hour conditions, no hotel related trip generation reductions
were made to provide a conservative (worse than expected) analysis scenario.
The directional distribution of the site generated trips (to and from) is based on existing
traffic patterns. Based on the traffic-generation and distribution estimates for the
proposed project, the traffic volumes associated were assigned to the local roadway
network as shown on Figures 6 and 7, respectively.
The proposed development is estimated to generate a total of 246 vehicle trips (189
entering trips and 57 exiting trips) during the weekday morning peak hour and a total of
314 vehicle trips (102 entering trips and 212 exiting trips) during the weekday afternoon
peak hour. The daily trip generation is estimated to be 2,341 vehicle trips (1,171
entering trips and 1,170 exiting trips)
Section 4 Build Conditions Tighe&Bond
Clarion Hotel Redevelopment Traffic Impact Study 4-2
TABLE 2
Clarion Hotel Redevelopment – Weekday Trip Generation
Land Use AM Peak Hour PM Peak Hour Daily
45,000 SF Office In 89 22 358
Out 12 107 358
Sub-Total 101 129 716
37,000 SF Medical
Office In 82 58 633
Out 41 91 632
Sub-Total 123 149 1,265
4,000 SF Restaurant In 18 22 180
Out 4 14 180
Sub-Total 22 36 360
Total
In 189 102 1,171
Out 57 212 1,170
Total 246 314 2,341
4.2 Traffic Volumes
The 2018 Build Condition is a result of the Clarion Hotel and Conference Center site
redevelopment trip generation added to the 2018 No Build Condition traffic volumes.
Figures 8 and 9 depict the 2018 Build Condition traffic volumes for the weekday morning
and afternoon peak hours, respectively.
Development of the proposed project will result in increases in traffic on the study area
roadways. As shown on Figures 6 and 7, the traffic-volume increases beyond the study
area are expected to be in the range of 37 to 79 vehicles during the weekday morning
and afternoon peak hours. These increases represent, on average, one additional
vehicle per 1.0 to 1.6 minutes. These projected increases conservatively assumed that
all patrons of the proposed restaurant were new trips to the surrounding area, there
were no multi-use trips between the proposed uses, and no reduction was applied due to
shared commuter trips (e.g., carpool) or public transportation. Therefore, the impacts
to the adjacent roadway system are anticipated to be better than as evaluated.
Tighe&Bond
Clarion Hotel Redevelopment Traffic Impact Study 5-1
Section 5
Mitigation
Impacts of project-related traffic on area roadways is addressed in Section 6 of the TIS.
That section evaluates Level of Service for the existing, no build, build and build with
mitigation scenarios. The project will result in minor additional traffic to the roadway
network, which will be mitigated through the measures described below.
5.1 Traffic Signal Installation
A warrant analysis was conducted to evaluate if the installation of a traffic signal is
warranted at the intersection of Atwood Drive and Mount Tom Road. The criterion within
the Manual on Uniform Traffic Devices (MUTCD)4 was used to determine if signalization
warrants are satisfied.
The MUTCD outlines nine traffic signal warrants that are used to evaluate traffic
conditions, pedestrian characteristics, and physical characteristics to justify the
installation of a traffic control signal. The 2018 No Build Condition traffic-volume data
were compared with the following MUTCD traffic-volume signal warrants:
Warrant 1, Eight-Hour Vehicular Volume
o Condition A – Minimum Vehicular Volume
o Condition B – Interruption of Continuous Traffic
o Combination of Conditions A and B
Warrant 2, Four-Hour Vehicular Volume
Warrant 3, Peak Hour
The satisfaction of one traffic signal warrant or warrants shall not in itself require the
installation of a traffic control signal. The intersection of Atwood Drive and Mount Tom
Road was evaluated using existing traffic volumes and geometry. Traffic-count data
were obtained from the ATR counts collected as part of the planned general and
medical-dental office space on Atwood Drive during the regular school and college
schedule. As shown in Table 3, Warrants 1 (Eight-Hour Vehicular Volume), 2 (Four-Hour
Vehicular Volume), and 3 (Peak Hour) are satisfied.
4 Manual on Uniform Traffic Control Devices: For Streets and Highways. [Washington, D.C.]: U.S.
Dept. of Transportation, Federal Highway Administration, 2010.
Section 5 Mitigation Tighe&Bond
Clarion Hotel Redevelopment Traffic Impact Study 5-2
TABLE 3 MUTCD Signal Warrants Summary #1A #1B #1 (Combined A&B) #2 #3 Yes Yes Yes Yes Yes
Source MUTCD 2009, Section 4D.
Since the Atwood Drive and Mount Tom Road intersection meets all five of the volume-
related warrants for signalization and based on traffic operating conditions without such
control, a traffic control signal is proposed to be installed at this location. Under the
2018 Build Conditions, the Atwood Drive and Mount Tom Road intersection has been
analyzed as a signalized intersection.
5.2 Traffic Signal Coordination System
In order to reduce travel delays and vehicle emissions along the Route 5 corridor and
enhance traffic flow and pedestrian safety, the existing traffic signal coordination system
will be modified to include the intersections of Atwood Drive, the I-91 northbound
ramps, and the I-91 southbound ramps.
Tighe&Bond
Clarion Hotel Redevelopment Traffic Impact Study 6-1
Section 6
Level of Service (LOS)
A primary result of a capacity analysis is the assignment of levels of service (LOS) to
traffic facilities under various traffic flow conditions. The concept of LOS is defined as a
qualitative measure describing operational conditions within a roadway network and
their perception by vehicle operators. A LOS definition provides an index to quantify
traffic flow in terms of such factors as speed, travel time, freedom to maneuver, traffic
interruptions, comfort, convenience, and safety.
Levels of service are assigned letter designations from A through F, representing the
highest to lowest operating conditions, respectively. Since the LOS of a traffic facility is
a function of the traffic flows placed upon it, such a facility may operate at a wide range
of LOS, depending on the time of day, day of week, or period of year.
Levels of service for the unsignalized intersections were calculated using the operational
analysis methodology of the 2010 Highway Capacity Manual using Synchro 8 Traffic
Signal Coordination software to estimate the delays and LOS. The proposed roundabout
level of service analysis wascalculated using the 2010 Highway Capacity Manual using
the Georgia Department of Transportation Roundabout Analysis Tool, V2.1.
Tables 4 and 5 provide a summary of the signalized intersection LOS, delay, and v/c
(volume-to-capacity) ratios for the weekday morning and afternoon peak hours,
respectively. Tables 6 and 7 provide a summary of the unsignalized intersection LOS,
delay, and v/c ratios for the weekday morning and afternoon peak hours, respectively.
6.1 Existing Conditions
The capacity analyses results indicate that the signalized intersection of Mount Tom
Road and the I-91 northbound ramps is operating at an overall LOS C during the
weekday morning peak hour and LOS F during the weekday afternoon peak hour.
At the unsignalized intersection of Mount Tom Road and the I-91 southbound ramps, the
capacity analyses indicate that the exiting ramp left turns operate with long delays (LOS
F) during the weekday morning and afternoon peak hours and over capacity (v/c >1.00)
during the weekday afternoon peak hour. The right turn lane from the exiting ramp is
operating at LOS B during the weekday morning peak hour and LOS C during the
weekday afternoon peak hour.
At the unsignalized intersection of Mount Tom Road and Atwood Drive, the capacity
analyses indicate that the Atwood Drive eastbound approach operates at LOS D during
the weekday morning peak hour and LOS C during the weekday afternoon peak hour.
The Mount Tom Road northbound left turns are operating at LOS A during the weekday
morning and afternoon peak hours.
At the unsignalized intersection of Conz Street and Route 5 (Pleasant Street/Mount Tom
Road), the capacity analyses indicate the Conz Street left turns operate at LOS F during
the weekday morning and afternoon peak hours, and the Conz Street right turns operate
at LOS B during the weekday morning peak hour and at LOS C during the weekday
afternoon peak hour. The Conz Street left turns operate with long delays (LOS F) during
the weekday morning and afternoon peak hours and over capacity (v/c >1.00) during
Section 6 Level of Service (LOS) Tighe&Bond
Clarion Hotel Redevelopment Traffic Impact Study 6-2
the weekday afternoon peak hour. The gas station driveway and Conz Street left turns
operate with long delays and over capacity (v/c >1.00) during the weekday morning and
afternoon peak hours.
6.2 2018 No Build
The capacity analyses results indicate that the signalized intersection of Mount Tom
Road and the I-91 northbound ramps, as a result of the MassDOT off-ramp widening
project, is projected to operate at an overall LOS B during the weekday morning and
afternoon peak hours with the lane groups operating at LOS C or better.
The intersection of Mount Tom Road and the I-91 southbound ramps is planned to be
signalized as a part of a MassDOT improvement project. The capacity analyses indicate
that the overall intersection will operate at LOS B during the weekday morning and
afternoon peak hours with the lane groups operating at LOS D or better.
The capacity analyses indicate that the Atwood Drive eastbound approach at the
unsignalized intersection with Mount Tom Road is projected to operate at LOS E during
the weekday morning peak hour and with long delays (LOS F) and over capacity (v/c
>1.00) during the weekday afternoon peak hour. The Mount Tom Road northbound left
turns are projected to operate at LOS A during the weekday morning and afternoon peak
hours.
The intersection of Conz Street and Route 5 (Pleasant Street/Mount Tom Road) is
planned to be converted into a single lane roundabout as part of a MassDOT
improvement project. As a result of the roundabout conversion, all of the approaches
are estimated to operate at LOS C or better during the weekday morning peak hour
period. During the weekday afternoon peak hour, the Route 5 (Pleasant Street/Mount
Tom Road) southbound approach and the Conz Street eastbound approach are expected
to experience LOS F, the Route 5 (Pleasant Street/Mount Tom Road) southbound
approach at LOS E, and the gasoline driveway approach at LOS B. The Route 5
(Pleasant Street/Mount Tom Road) northbound and southbound approaches and the
Conz Street eastbound approach are projected to operate with capacity constraints (v/c
>1.00) during the weekday afternoon peak hour.
6.3 2018 Build Mitigated
The 2018 Build Mitigated Conditions are based on the 2018 Build Condition traffic
volumes, the signalization of the Mount Tom Road and Atwood Drive intersection, and
the traffic signal coordination modifications to the Mount Tom Road corridor.
Under the 2018 Build Mitigated Condition, the capacity analyses results indicate that the
signalized intersection of Mount Tom Road and the I-91 northbound ramps is projected
to operate at an overall LOS C during the weekday morning and LOS B during the
weekday afternoon peak hours with the lane groups operating at LOS C or better.
The capacity analyses indicate that the intersection of Mount Tom Road and the I-91
southbound ramps will operate at LOS B or better during the weekday morning and
afternoon peak hours. The lane group movements are projected to continue operating
at LOS D or better during the weekday morning and afternoon peak hours.
Section 6 Level of Service (LOS) Tighe&Bond
Clarion Hotel Redevelopment Traffic Impact Study 6-3
The capacity analyses indicate that the signalization of the Atwood Drive intersection
with Mount Tom Road will result with an overall LOS A during the weekday morning peak
hour and LOS B during the weekday afternoon peak hour. The lane groups are
anticipated to be at LOS C or better during the weekday morning and afternoon peak
hours.
As a result of the new development traffic, the roundabout intersection of Conz Street
and Route 5 (Pleasant Street/Mount Tom Road) is anticipated to continue to operate at
LOS C or better during the weekday morning peak hour and with long delays (LOS E/F)
and capacity constraints (v/c >1.00) during the weekday afternoon peak hour.
Tighe&Bond
Clarion Hotel Redevelopment Traffic Impact Study 7-1
Section 7
Conclusion
The proposed site will be redeveloped to provide a mixed use containing 45,000 square
feet of general office space, 35,000 square feet of medical office space, a 4,000 square
foot quality restaurant, and a reduction in hotel space from 127 rooms to 107 rooms.
The proposed redevelopment is estimated to generate a total of 246 vehicle trips (189
entering trips and 57 exiting trips) during the weekday morning peak hour and a total of
314 vehicle trips (102 entering trips and 212 exiting trips) during the weekday afternoon
peak hour.
The results of the capacity analyses indicate that the proposed redevelopment trip
generation along with the mitigation efforts will result in minimal impact to the study
intersections. These results are based on a conservative (worse than expected)
methodology as a higher historical growth rate was used than data support, all patrons
of the proposed restaurant were evaluated as new trips to the surrounding area (i.e., no
trip credit for vehicles already within the adjacent traffic stream [pass-by trips]), there
were no multi-use trips between the proposed uses (e.g., a hotel guest also visiting the
restaurant), and no reduction was applied due to shared commuter trips (e.g., carpool)
or public transportation.
J:\H\H1363\Traffic\Mix Use Site\Report\Sept 2013\Clarion Redevelopment Report_rev.doc
A
APPENDIX A
BAPPENDIX B
CAPPENDIX C
APPENDIX D
APPENDIX D
Hospitality North
Atwood Drive
Northampton, Massachusetts
Stormwater
Management Report
Prepared For:
Atwood Drive, LLC
March 2017
Table of Contents Tighe&Bond
i
Section 1 Registered Professional Engineer's Certification
Section 2 Project Description
2.1 Project Summary ...........................................................................2-1
2.2 Existing Conditions .........................................................................2-1
2.3 Proposed Improvements .................................................................2-3
2.4 Hydrologic Analysis ........................................................................2-7
Section 3 Regulatory Compliance
3.1 LID Measures.................................................................................3-1
3.2 Standard 1: No New Untreated Discharges ........................................3-1
3.3 Standard 2: Peak Discharge Rate Attenuation ....................................3-2
3.4 Standard 3: Groundwater Recharge ..................................................3-2
3.5 Standard 4: Water Quality ...............................................................3-2
3.6 Standard 5: Land Uses with Higher Potential Pollutant Loads (LUHPPLs) 3-4
3.7 Standard 6: Critical Areas ...............................................................3-4
3.8 Standard 7: Redevelopment Projects ................................................3-4
3.9 Standard 8: Construction Period Pollution Prevention, Erosion and
Sedimentation Control ....................................................................3-4
3.10 Standard 9: Long-Term Operation and Maintenance Plan ....................3-5
3.11 Standard 10: Prohibition of Illicit Discharges ......................................3-5
3.12 City of Northampton Stormwater Management Regulations .................3-5
Appendices
A Massachusetts Stormwater Checklist
B Figures
Figure 1: USGS Site Locus Map
Figure 2: Priority Resource Map
Figure 3: Orthophotograph
Figure 4: Existing Conditions Drainage Area Map
Figure 5: Proposed Conditions Drainage Area Map
C NRCS Soils Information, Test-pit and Boring Logs
D Stormwater Calculations (Hydrologic Analysis calculations not included)
E Stormwater Operation & Maintenance Plan
F Draft Stormwater Pollution Prevention Plan (Not included)
G Illicit Discharge Statement
J:\H\H1363\Atwood North\Permits\Stormwater\December 2016\1713634_Stormwater_Report.docx
Tighe&Bond
Atwood North Redevelopment Project
Stormwater Management Report 2-1
Section 2
Project Description
2.1 Project Summary
Project Location
Project Name: Atwood North Redevelopment Project
Project Location: 23 Atwood Drive, Northampton, MA 01060
Project Proponent: Atwood Partners, LLC
The proposed Atwood North Redevelopment Project includes redevelopment of the former
Clarion Hotel and Conference Center on Atwood Drive in Northampton, Massachusetts with
approximately 138,000 gross square feet of general and medical office space with
associated site appurtenances on the parcel owned by Atwood Drive, LLC north of Atwood
Drive (the Site). As depicted in Figures 1 through 3 (USGS site locus map, Priority
Resources Map, and Orthophotograph, attached in Appendix B), the project is located west
of Mount Tom Road (Route 5) and north of Atwood Drive in Northampton.
This Stormwater Management Report has been prepared to support local, state and federal
permitting requirements. The Atwood North Redevelopment Project was previously
approved through local regulatory officials in November 2013. While the proposed
development program and specific tenants have changed, the stormwater management
system intent remains as previously approved.
2.2 Existing Conditions
The site is located within the General Business zoning district and the Floodplain Overlay
district. The existing site is developed and utilized as the Clarion Hotel and Conference
Center with various exterior amenities including parking, swimming pool and tennis courts.
Land surrounding the project site is occupied by new development of office space to the
south, Interstate 91 to the north and west, and Mt. Tom Road (Route 5) to the east. The
majority of the site is under the 100-yr flood elevation, which makes the Site subject to
the Wetlands Protection Act in addition to the proximity to the Bordering Vegetated
Wetland (BVW) located in the western and northwestern portions of the property.
The NRCS soil data was obtained through the Web Soil Survey portal on the USDA NRCS
website. The areas surrounding the property were queried for soil types according to the
record soil survey maps maintained by NRCS. Soils within the project area, as published
in the USDA Soil Survey for Hampshire County, Version 11, dated September 14, 2016,
include the Hadley-Winooski-Urban land complex. The hydrologic soil group designation
(HSG) for this soil type is a ‘Type-B’. The HSG rating for soil types is based on estimates
of runoff potential. Soils are assigned to one of four groups according to the rate of water
infiltration when the soils are not protected by vegetation, are thoroughly wet, and receive
precipitation from long duration storms. Soils designated as HSG B generally have a
moderate infiltration capacity and are well drained despite their finer texture. Based on
this, soils within the project area are moderately conducive to infiltration. The NRCS Soils
Mapping is provided in Appendix C.
Section 2 Project Description Tighe&Bond
Atwood North Redevelopment Project
Stormwater Management Report 2-2
Testpits were performed in June 2013. Test pit locations are noted on the Site Plans and
testpit logs are provided in Appendix C. Review of the test pit reports indicate that
underlying soils are generally fine sandy loams. Signs of mean annual high groundwater
were observed at approximately 82-inches below existing grade. In comparison of the
NRCS record soils data and actual observations of the test pits, we have concluded that
the soils present are generally consistent with those indicated in the NRCS soils data.
Bedrock was never encountered during the course of the explorations. Therefore, no
modification to the NRCS soils data is required.
Under existing conditions, minimally treated and untreated stormwater runoff from the
site flows in two general directions which contribute to the same wetland system identified
as Design Point 1 (DP-1) to the northwest of the project area. In addition to the
stormwater runoff from the majority of the site, flows collected by the stormwater
collection system in Atwood Drive also discharge to DP-1. This collection system is also
the conveyance mechanism for a portion of the on-site stormwater flows from parking
area collection points. Additionally, a portion of the site conveys stormwater runoff to
the north, and discharges off-site through paved swales to DP-1.
An Existing Conditions Drainage Area Map is provided as Figure 4 in Appendix B. The
runoff curve numbers (RCN) used in the calculation of the composite RCN for each
drainage area is based on the values provided in TR-55, Urban Hydrology for Small
Watersheds. RCN values vary depending on the type of ground cover and soil HSG. The
RCN values used in hydrologic analysis are provided in Table 2.1.
Table 2.1
Existing Conditions Runoff Curve Numbers
A summary of each existing conditions subcatchment area, its size and associated
composite RCN is provided in Table 2.2 below.
Table 2.2
Existing Conditions Drainage Area Summary
Drainage Area
Designation
Drainage Area Size
(acres)
Composite Runoff Curve
Number (RCN)
Drainage Area 1S 1.426 77
Drainage Area 2AS 0.901 72
Drainage Area 2BS 0.210 97
Drainage Area 3S 0.973 92
Ground Cover Type Runoff Curve
Number
Paved parking, HSG B 98
Roofs, HSG B 98
Grass Cover, Fair (50-75% cover), HSG B 69
Unconnected pavement, HSG B 98
Woods, Fair, HSG B 60
Water Surface, HSG B 98
Section 2 Project Description Tighe&Bond
Atwood North Redevelopment Project
Stormwater Management Report 2-3
Drainage Area 4S 0.169 96
Drainage Area 5S 0.474 92
Drainage Area 6S 0.200 88
Drainage Area 7S 0.570 94
Drainage Area 8S 0.203 92
Drainage Area 9AS 0.100 95
Drainage Area 9BS 0.530 94
Drainage Area 10S 0.125 98
Drainage Area 11S 0.291 97
Drainage Area 12S 0.429 93
Drainage Area 13S 0.304 92
Drainage Area 14AS 0.410 95
Drainage Area 14BS 0.480 97
Drainage Area 15S 0.185 89
Drainage Area 16S 0.199 93
Drainage Area 17S 0.237 90
Drainage Area 18S 0.324 93
Drainage Area 19S 0.281 86
Drainage Area 20S 0.264 87
Drainage Area 21S 0.231 86
Drainage Area 22S 0.238 86
Drainage Area 23S 0.318 84
Total 10.072 88
2.3 Proposed Improvements
The project includes the demolition of the existing Clarion Hotel and Conference Center,
which occurred in Fall 2016. The proposed redevelopment includes the construction of
approximately 138,000 gross square feet of general and medical office space, with
supporting appurtenances such as access drives and parking areas, pedestrian and
bicyclist accommodations, utility services and stormwater management features. The
project will result in an increase in impervious ground surface.
The proposed drainage conditions at the project site were divided into 32 new
subcatchments. These subcatchment areas, along with the 9 existing subcatchment areas
to remain in Atwood Drive, are shown on Figure 5, Proposed Conditions Drainage Area
Map, provided in Appendix B. A description of the areas, as well as their proposed
stormwater management features, are as follows:
Drainage Areas 1S-5S: These drainage areas include all of the pavements to the
North and to the East of Building 1. In Drainage Area 2S, stormwater flows in a
southerly direction to the Bioretention Basin in Drainage Area 22S. A 50’ long
pretreatment strip separates the basin from the abutting drive and a provides the
necessary pre-treatment to water entering the basin. An outlet control structure in
the basin houses the proposed overflow that directs stormwater into the existing
drainage system in Atwood Drive. The TSS removal efficiency for this subcatchment
area is 90% as illustrated in the sheet titled Treatment Train 4 found in Appendix
D of this report.
Section 2 Project Description Tighe&Bond
Atwood North Redevelopment Project
Stormwater Management Report 2-4
Drainage Areas 1S,3S,4S, and 5S are sloped to direct surface runoff into deep
sump catch basins located in the vegetated swales between the parking bays.
These catch basins direct flows to a Stormceptor treatment device that discharges
into Infiltration Basin 1. The TSS removal efficiency for these subcatchment areas
is 96% as illustrated in the sheet titled Treatment Train 1 found in Appendix D of
this report.
Drainage Area 21S: This drainage area at the northern property line boundary is
comprised of both pervious and impervious areas that discharge stormwater to the
wetland area North of the site. Under the existing conditions, untreated stormwater
flows from the paved parking areas to the bituminous concrete swales that outlet
to the wetland. The proposed design minimizes potential de-watering of the
wetlands, at the request of the Northampton Conservation Commission, by
mimicking the existing conditions and continuing to discharge stormwater to that
wetland area. Under the proposed conditions however, pretreatment strips and
vegetated slopes will filter runoff from the paved areas prior to it entering the
wetland.
Drainage Areas 6S–10S: These subcatchment areas include the northern half of
the parking areas between the two proposed buildings. The pavement in these
subcatchments is sloped to direct stormwater to the deep-sump hooded catch
basins located between the parking bays. These catch basins discharge to the main
storm drain line for the northern portion of the site that terminates at a
Stormceptor and overflows into Infiltration Basin 1. The TSS removal efficiency for
these subcatchment areas is 96% as illustrated in the sheet titled Treatment Train
1 found in Appendix D of this report.
Drainage Area 11S & 12S: These drainage areas include the two subcatchments
for the northern most parking lot. Area 11S directs stormwater flows into a catch
basin that outlets at Bioretention Basin 1 and Area 12S directs stormwater flows
directly into Bioretention Basin 1. The TSS removal efficiency for subcatchment
Area 12S is 90% as illustrated in the sheet titled Treatment Train 2 and the TSS
removal efficiency for subcatchment Area 11S is 93% as illustrated in the sheet
titled Treatment Train 5. Both Treatment Train documents can be found in
Appendix D of this report.
Drainage Areas 13S-16S: These subcatchment areas include both the paved and
the grassed areas around the sides and rear of Building 2. Areas 13S, 15S, and
16S sheet flow directly into Infiltration Basins 1 & 2. Area 14S slopes to a catch
basin that discharges into a Stormceptor with an outlet to Infiltration Basin 2. The
TSS removal efficiency for these subcatchment areas is 80% as illustrated in the
sheet titled Treatment Train 6 found in Appendix D of this report.
Drainage Areas 17S-19S: Subcatchment Areas 17S-19S include the majority of
the treatment BMP’s for the proposed project. The proposed native habitat feature,
both infiltration basins, and one of the bioretention basins are all located in these
subcatchment areas. There is no impervious coverage in these areas and all of
these drainage areas are designed to be vegetated and densely planted.
Drainage Area 20S: This subcatchment area is mostly wooded and is located at
the westernmost end of the project site. It includes a portion of the wetland that
Section 2 Project Description Tighe&Bond
Atwood North Redevelopment Project
Stormwater Management Report 2-5
abuts the project site as well as the Design Point DP-1. Treated stormwater is
discharged to this area via the proposed basin overflows and emergency spillways.
The municipal stormwater system located in Atwood Drive also discharges
stormwater into this drainage area at an existing outfall.
Drainage Areas 25S-32S: These subcatchment areas include all of the paved
and grassed areas between Buildings 1 & 2 along Atwood Drive. Pavements are
sloped to direct stormwater flows to deep-sump hooded catch basins. These catch
basins discharge to the main storm drain line for the southern portion of the site
that terminates at a Stormceptor and overflows into Infiltration Basin 2. The TSS
removal efficiency for these subcatchment areas is 96% as illustrated in the sheet
titled Treatment Train 3 found in Appendix D of this report.
The RCN used in the calculation of the composite RCN for each drainage area is based on
the values provided in Table 2.3.
Table 2.3
Proposed Conditions Runoff Curve Numbers
A summary of each proposed conditions subcatchment area, its size and associated
composite RCN is provided in Table 2.4 below.
Table 2.4
Proposed Conditions Drainage Area Summary
Drainage Area
Designation
Drainage Area Size
(acres)
Composite Runoff Curve
Number (RCN)
Drainage Area 1S 0.387 94
Drainage Area 2S 0.258 95
Drainage Area 3S 0.216 93
Drainage Area 4S 0.443 95
Drainage Area 5S 0.042 98
Drainage Area 6S 0.394 93
Drainage Area 7S 0.232 94
Drainage Area 8S 0.232 94
Drainage Area 9S 0.356 95
Drainage Area 10S 0.223 93
Drainage Area 11S 0.276 98
Drainage Area 12S 0.079 98
Ground Cover Type Runoff Curve
Number
Paved parking, HSG B 98
Grass Cover, Fair (50-75% cover), HSG B 69
Grass Cover, Good (>75% cover), HSG B 61
Roofs, HSG B 98
Woods, Fair, HSG B 60
Water Surface, HSG B 98
Section 2 Project Description Tighe&Bond
Atwood North Redevelopment Project
Stormwater Management Report 2-6
Drainage Area 13S 0.199 82
Drainage Area 14S 0.061 98
Drainage Area 15S 0.100 89
Drainage Area 16S 0.238 81
Drainage Area 17S 0.433 98
Drainage Area 18S 0.299 98
Drainage Area 19S 0.157 98
Drainage Area 20S 0.585 74
Drainage Area 21S 0.289 82
Drainage Area 22S 0.116 98
Drainage Area 23S 0.504 98
Drainage Area 24S 0.442 98
Drainage Area 25S 0.252 94
Drainage Area 26S 0.164 94
Drainage Area 27S 0.164 93
Drainage Area 28S 0.265 92
Drainage Area 29S 0.093 89
Drainage Area 30S 0.064 93
Drainage Area 31S 0.067 92
Drainage Area 32S 0.114 85
Existing areas that contribute to proposed conditions (Atwood Drive):
Drainage Area 15 0.185 89
Drainage Area 16 0.199 93
Drainage Area 17 0.237 90
Drainage Area 18 0.324 93
Drainage Area 19 0.281 86
Drainage Area 20 0.264 87
Drainage Area 21 0.231 86
Drainage Area 22 0.238 86
Drainage Area 23 0.318 84
Total 10.07 91
The proposed stormwater management system improves both the quality and the quantity
of stormwater discharge from the site. The system includes best management practices
(BMP’s) such as deep-sump, hooded catch basins, bioretention basins (rain gardens),
proprietary stormwater treatment units and two infiltration basins.
A brief description of the proposed Best Management Practices incorporated into the
stormwater management system are as follows:
Deep-Sump, Hooded Catch Basins: Catch basins provided throughout the side
collect stormwater runoff from the proposed parking areas and are connected to
the project’s stormwater collection system. The deep-sump and hooded outlet
provide runoff an opportunity to separate from solids and floatable pollutants prior
to discharge and are used as a pretreatment device throughout the project.
Section 2 Project Description Tighe&Bond
Atwood North Redevelopment Project
Stormwater Management Report 2-7
Bioretention Basins: The landscaped bioretention basins throughout the site will
serve as detention, pretreatment and infiltration areas for stormwater runoff.
Planted with native, non-invasive species such as Summersweet (clethra alnifolia)
and Red Twig Dogwood (cornus sericea), the bioretention areas will not only treat
captured stormwater but will also facilitate groundwater recharge.
Proprietary Treatment Devices: Structural stormwater treatment devices,
proposed as Stormceptor STC900 (or equal) are designed to mechanically separate
pollutants from stormwater flows through centrifugal force and vortex separation.
Units are proposed at the ends of both major treatment trains in the stormwater
management system, prior to discharging into the infiltration basins.
Infiltration Basin: The proposed surface infiltration basins are the collection points
for the majority of runoff from the project and are located in the westernmost
portion of the project area. The infiltration basins have been designed in
accordance with the Massachusetts Stormwater Standards to provide the required
groundwater recharge and water quality volume for the project. Outlet control
devices regulate the quantity of stormwater discharged to the wetland west of the
basins (DP-1). The basins are also equipped with emergency overflow spillways to
minimize the potential for flooding.
The proposed site work reflects an improvement to the manner in which stormwater is
managed at the Atwood North Redevelopment. The existing system lacks any
pretreatment or flow rate attenuation, and very little on-site infiltration currently occurs
prior to runoff discharging to DP-1.
2.4 Hydrologic Analysis
A hydrologic analysis of the pre-development and post-development site was performed
to determine the impacts of the proposed project to peak discharge rates and stormwater
runoff volumes. HydroCAD Release 9.10 is a hydrology and hydraulics software using
Technical Release (TR) 20 and TR-55 methodologies for the determination of stormwater
runoff quantities. The HydroCAD Report for both pre- and post-development conditions
for the 2-, 10-, 25- and 100-year storm events is provided in Appendix D. Rainfall depths
used in the analysis are consistent with for Hampshire County and as provided in Table
2.5 below.
Table 2.5
Design Rainfall Depths
Storm Event Rainfall Depth
(inches)
2-Year 3.07
10-Year 4.47
25-Year 5.54
100-Year 7.68
Tighe&Bond
Atwood North Redevelopment Project
Stormwater Management Report 3-1
Section 3
Regulatory Compliance
The project is required to comply with the ten Massachusetts Department of
Environmental Protection (MassDEP) Massachusetts Stormwater Standards (Standards)
under the Massachusetts Wetlands Protection Act and the City of Northampton Stormwater
Regulations. The Massachusetts Stormwater Checklist is provided in Appendix A.
3.1 LID Measures
MassDEP allows for reductions in structural stormwater Best Management Practice (BMP)
requirements for water quantity and quality when certain criteria are met. The proposed
project includes environmentally sensitive site design and low impact development
techniques; however, the applicant is not requesting credit for LID measures because they
are not necessary.
3.2 Standard 1: No New Untreated Discharges
The project will not result in any new stormwater conveyance discharging untreated
stormwater directly to the waters of the Commonwealth. Existing drainage patterns on
the site are generally maintained, however the new stormwater system collects, conveys,
and treats runoff prior to discharge at an existing outfall in the western portion of the
project. Further documentation pertaining to stormwater treatment is provided in Section
3.5.
It is not anticipated that erosive stormwater velocities will be encountered post-
construction subsequently causing erosion and siltation to waters of the Commonwealth.
All discharges have been designed to meet the thresholds identified in Volume 3 of the
Massachusetts Stormwater Handbook. A summary of stormwater discharge velocities for
the 2-year, 24-hour storm event are provided in Table 3.1, below, accompanied by
permissible velocities as provided by MassDEP.
Table 3.1
Stormwater Discharge Velocities
Discharge
Location
2-year Storm Event
(cfs)
2-Year Storm Event
Velocity (fps)
Maximum
Permissible Velocity
(fps)1
Existing 18”
Outfall 7.4 4.2 5.0
Northern
property
border
0.5 0.1 5.0
FES-3 1.7 0.5 5.0
FES-6 1.7 0.5 5.0
FES-7 1.7 0.5 5.0
FES-9 0 0 5.0
Section 3 Regulatory Compliance Tighe&Bond
Atwood North Redevelopment Project
Stormwater Management Report 3-2
1 Maximum Permissible Velocity is based on Table 2.3.1 of Volume 3 of the MassDEP
Stormwater Handbook
3.3 Standard 2: Peak Discharge Rate Attenuation
The proposed project will not substantially alter the existing stormwater flow paths at the
site through use of infiltration and detention. Runoff is collected by grassed swales and
deep-sump, hooded catch basins located within the parking areas and conveyed to the
infiltration basins or bioretention areas where runoff is detained prior to discharge. Table
3.2 presents the results of the pre-development stormwater runoff analysis versus the
post-development stormwater runoff analysis, previously described in Section 2.4, for
project.
Table 3.2
Peak Discharge Rate Comparison – Design Point 1 (Wetland)
2-Year Storm
Event (cfs)
10-Year Storm
Event (cfs)
25-Year Storm
Event (cfs)
100-Year
Storm Event
(cfs)
Existing 20.41 33.83 44.30 64.52
Proposed 13.02 27.63 34.45 50.15
Table 3.2 indicates that existing peak discharge rates are reduced for all storm events.
3.4 Standard 3: Groundwater Recharge
The proposed project will allow treated stormwater runoff from the proposed project to
infiltrate to groundwater. The surface infiltration basins include outlet control structures
to regulate the quantity of stormwater discharged from the basin after the required volume
of stormwater is allowed to infiltrate. The infiltration systems have been designed in
accordance with the MassDEP Stormwater Handbook and provide the required recharge
volume. Since the project does not collect all stormwater runoff from the proposed parking
area, specifically in areas where runoff is allowed to sheet flow to the north to continue to
feed the existing wetland through paved swales to mimic existing conditions, a capture
area adjustment has been accounted for in the recharge volume calculations.
The rain gardens situated throughout the site were also designed to provide some level of
groundwater recharge. Planted with native groundcovers, shrubs, and understory trees,
these basins will be constructed using a soil mix and profile appropriate for infiltration and
in accordance with Volume 2, Chapter 2 of the Massachusetts Stormwater Handbook.
Recharge calculations are provided in Appendix D.
3.5 Standard 4: Water Quality
Standard 4 of the Massachusetts Stormwater Standards addresses stormwater quality
requirements. This standard requires that new stormwater management systems be
designed to achieve an 80% Total Suspended Solids (TSS) removal rate prior to discharge.
MassDEP has published presumed removal rates for each of the BMP’s featured in their
design guidelines. Additionally, this standard addresses the required volume of
Section 3 Regulatory Compliance Tighe&Bond
Atwood North Redevelopment Project
Stormwater Management Report 3-3
stormwater runoff that is to be treated by the BMPs, as well as components of a long-term
source control and pollution prevention plan.
The project has been designed to mimic existing conditions in efforts to continue to convey
stormwater runoff to the north to the existing wetland area. At the request of the
Northampton Conservation Commission during a pre-application meeting, the proposed
stormwater management system will continue to convey stormwater runoff to the wetland
to the north. Options were explored to provide “clean” runoff to this area, such as from
building rooftops; however, due to the minimal available space on the subject property
and existing grades, this option was determined to be not feasible.
As such, the project does not capture and treat all the stormwater runoff from the
proposed development. Therefore, the required Water Quality Volume is treated
elsewhere within the development. A weighted TSS removal efficiency for the overall
project has been determined to be 80% which includes the untreated discharges to the
wetlands to the north.
Table 3.3
TSS Removal Efficiencies
Treatment Train 1 80% 2.59 Acres
Treatment Train 2 90% 0.08 Acres
Treatment Train 3 80% 1.47 Acres
Treatment Train 4 90% 0.26 Acres
Treatment Train 5 93% 0.50 Acres
Treatment Train 6 80% 1.36 Acres
Untreated Stormwater1 0% 0.13 Acres
6.39 Acres
Weighted Average TSS Removal 80% 1 Untreated stormwater runoff discharging to the existing wetland to the north of the project at the request of
the Northampton Conservation Commission.
TSS removal worksheets are provided in Appendix D which further describe each
treatment train presented above. The water quality volume requirement is satisfied by
the utilization of grassed swales, rain gardens, deep-sump hooded catch basins and
infiltration basin.
The National Pollutant Discharge Elimination System (NPDES) administered by the
Environmental Protection Agency (EPA) requires that a SWPPP be prepared as the site
will disturb over one-acre of earth. A SWPPP was prepared by the contractor and a Notice
of Intent with the EPA was filed prior to construction. The owner of the project is
performing the monitoring and the reporting responsibilities as outlined in the SWPPP.
Section 3 Regulatory Compliance Tighe&Bond
Atwood North Redevelopment Project
Stormwater Management Report 3-4
3.6 Standard 5: Land Uses with Higher Potential
Pollutant Loads (LUHPPLs)
It is anticipated that the proposed project uses will generate more than 1,000 vehicle trips
per day, therefore the site has been designated as a LUHPPL. Therefore, the following
conditions have been met through design:
1. BMPs are suitable for treating runoff from LUHPPL through the use of grassed
channels, bioretention areas, infiltration basins, and deep sump hooded catch
basins.
2. The Required Water Quality Volume was calculated with 1” required depth (See
Appendix D).
3. Pretreatment BMPs have been included to meet 44% TSS removal prior to
infiltration (See Appendix D for BMP Treatment Train Worksheets).
4. Filtering bioretention areas have been included in order to minimize the effect of
oil and grease, should elevated concentrations exist in runoff.
The proposed BMPs of the stormwater management system have been designed in
compliance with the requirements of Standard 5 and the Massachusetts Stormwater
Handbook. Calculations supporting the more stringent Required Water Quality volume
and 44% TSS removal prior to infiltration are provided in Appendix D. A long term
pollution prevention plan has also been developed for the project and is provided in
Appendix F.
3.7 Standard 6: Critical Areas
The site discharges stormwater runoff to an un-named wetland as the first receiving water.
The wetland area abuts the Connecticut River but is not located in a Critical Area as defined
in the Massachusetts Stormwater Standards or 314 CMR 4.00.
The project will not result in any new discharges to the Connecticut River. Existing
drainage patterns will be maintained and stormwater quality will be improved as a result
of the development.
3.8 Standard 7: Redevelopment Projects
The project is considered a combination or new development and redevelopment. The
increase in impervious groundcover resulting from the construction of new office space is
considered new development while a portion of the impervious areas can be considered a
redevelopment. However, the project has been designed to fully comply with all the
Standards.
3.9 Standard 8: Construction Period Pollution
Prevention, Erosion and Sedimentation Control
There will be more than one acre of land disturbed as a result of this project, therefore an
EPA NPDES Construction General Permit was obtained before construction commenced. A
Section 3 Regulatory Compliance Tighe&Bond
Atwood North Redevelopment Project
Stormwater Management Report 3-5
SWPPP was prepared by the contractor prior to construction that meets the requirements
of the MassDEP Stormwater Handbook Standard 8 and EPA NPDES General Construction
Permit.
Construction Period Pollution Prevention and Erosion and Sedimentation control measures
are provided on the separately attached Permitting Plans and in the Stormwater
Operations and Maintenance Plan included in Appendix E of this Stormwater Report.
3.10 Standard 9: Long-Term Operation and Maintenance
Plan
A Stormwater Operations and Maintenance Plan is included in Appendix E of this report.
The O&M plan indicates the responsible parties for the project, routine and non-routine
maintenance tasks and inspection criteria.
3.11 Standard 10: Prohibition of Illicit Discharges
Illicit discharges to the stormwater management system are discharges that are not
entirely comprised of stormwater. Illicit discharge does not include discharges from the
following activities or facilities: firefighting, water line flushing, landscape irrigation,
uncontaminated groundwater, potable water sources, foundation drains, air conditioning
condensation, footing drains, individual resident car washing, flows from riparian habitats
and wetlands, dechlorinated water from swimming pools, water used for street washing,
and water used to clean residential buildings without detergents. A signed Illicit Discharge
Statement is provided in Appendix G.
3.12 City of Northampton Stormwater Management
Regulations
The project has been designed in accordance with the City of Northampton Stormwater
Management (Chapter 281) requirements. The requirements generally mimic those of the
Massachusetts Stormwater Standards, with additional design requirements for stormwater
infiltration systems and erosion and sedimentation control features.
J:\H\H1363\Atwood North\Permits\Stormwater\December 2016\1713634_Stormwater_Report.docx
A
APPENDIX A
swcheck • 04/01/08 Stormwater Report Checklist • Page 3 of 8
Massachusetts Department of Environmental Protection
Bureau of Resource Protection - Wetlands Program Checklist for Stormwater Report
Checklist (continued)
LID Measures: Stormwater Standards require LID measures to be considered. Document what
environmentally sensitive design and LID Techniques were considered during the planning and design of
the project:
No disturbance to any Wetland Resource Areas
Site Design Practices (e.g. clustered development, reduced frontage setbacks)
Reduced Impervious Area (Redevelopment Only)
Minimizing disturbance to existing trees and shrubs
LID Site Design Credit Requested:
Credit 1
Credit 2
Credit 3
Use of “country drainage” versus curb and gutter conveyance and pipe
Bioretention Cells (includes Rain Gardens)
Constructed Stormwater Wetlands (includes Gravel Wetlands designs)
Treebox Filter
Water Quality Swale
Grass Channel
Green Roof
Other (describe):
Standard 1: No New Untreated Discharges
No new untreated discharges
Outlets have been designed so there is no erosion or scour to wetlands and waters of the
Commonwealth
Supporting calculations specified in Volume 3 of the Massachusetts Stormwater Handbook included.
swcheck • 04/01/08 Stormwater Report Checklist • Page 4 of 8
Massachusetts Department of Environmental Protection
Bureau of Resource Protection - Wetlands Program Checklist for Stormwater Report
Checklist (continued)
Standard 2: Peak Rate Attenuation
Standard 2 waiver requested because the project is located in land subject to coastal storm flowage
and stormwater discharge is to a wetland subject to coastal flooding.
Evaluation provided to determine whether off-site flooding increases during the 100-year 24-hour
storm.
Calculations provided to show that post-development peak discharge rates do not exceed pre-
development rates for the 2-year and 10-year 24-hour storms. If evaluation shows that off-site
flooding increases during the 100-year 24-hour storm, calculations are also provided to show that
post-development peak discharge rates do not exceed pre-development rates for the 100-year 24-
hour storm.
Standard 3: Recharge
Soil Analysis provided.
Required Recharge Volume calculation provided.
Required Recharge volume reduced through use of the LID site Design Credits.
Sizing the infiltration, BMPs is based on the following method: Check the method used.
Static Simple Dynamic Dynamic Field1
Runoff from all impervious areas at the site discharging to the infiltration BMP.
Runoff from all impervious areas at the site is not discharging to the infiltration BMP and calculations
are provided showing that the drainage area contributing runoff to the infiltration BMPs is sufficient to
generate the required recharge volume.
Recharge BMPs have been sized to infiltrate the Required Recharge Volume.
Recharge BMPs have been sized to infiltrate the Required Recharge Volume only to the maximum
extent practicable for the following reason:
Site is comprised solely of C and D soils and/or bedrock at the land surface
M.G.L. c. 21E sites pursuant to 310 CMR 40.0000
Solid Waste Landfill pursuant to 310 CMR 19.000
Project is otherwise subject to Stormwater Management Standards only to the maximum extent
practicable.
Calculations showing that the infiltration BMPs will drain in 72 hours are provided.
Property includes a M.G.L. c. 21E site or a solid waste landfill and a mounding analysis is included.
1 80% TSS removal is required prior to discharge to infiltration BMP if Dynamic Field method is used.
swcheck • 04/01/08 Stormwater Report Checklist • Page 5 of 8
Massachusetts Department of Environmental Protection
Bureau of Resource Protection - Wetlands Program Checklist for Stormwater Report
Checklist (continued)
Standard 3: Recharge (continued)
The infiltration BMP is used to attenuate peak flows during storms greater than or equal to the 10-
year 24-hour storm and separation to seasonal high groundwater is less than 4 feet and a mounding
analysis is provided.
Documentation is provided showing that infiltration BMPs do not adversely impact nearby wetland
resource areas.
Standard 4: Water Quality
The Long-Term Pollution Prevention Plan typically includes the following:
Good housekeeping practices;
Provisions for storing materials and waste products inside or under cover;
Vehicle washing controls;
Requirements for routine inspections and maintenance of stormwater BMPs;
Spill prevention and response plans;
Provisions for maintenance of lawns, gardens, and other landscaped areas;
Requirements for storage and use of fertilizers, herbicides, and pesticides;
Pet waste management provisions;
Provisions for operation and management of septic systems;
Provisions for solid waste management;
Snow disposal and plowing plans relative to Wetland Resource Areas;
Winter Road Salt and/or Sand Use and Storage restrictions;
Street sweeping schedules;
Provisions for prevention of illicit discharges to the stormwater management system;
Documentation that Stormwater BMPs are designed to provide for shutdown and containment in the
event of a spill or discharges to or near critical areas or from LUHPPL;
Training for staff or personnel involved with implementing Long-Term Pollution Prevention Plan;
List of Emergency contacts for implementing Long-Term Pollution Prevention Plan.
A Long-Term Pollution Prevention Plan is attached to Stormwater Report and is included as an
attachment to the Wetlands Notice of Intent.
Treatment BMPs subject to the 44% TSS removal pretreatment requirement and the one inch rule for
calculating the water quality volume are included, and discharge:
is within the Zone II or Interim Wellhead Protection Area
is near or to other critical areas
is within soils with a rapid infiltration rate (greater than 2.4 inches per hour)
involves runoff from land uses with higher potential pollutant loads.
The Required Water Quality Volume is reduced through use of the LID site Design Credits.
Calculations documenting that the treatment train meets the 80% TSS removal requirement and, if
applicable, the 44% TSS removal pretreatment requirement, are provided.
swcheck • 04/01/08 Stormwater Report Checklist • Page 6 of 8
Massachusetts Department of Environmental Protection
Bureau of Resource Protection - Wetlands Program Checklist for Stormwater Report
Checklist (continued)
Standard 4: Water Quality (continued)
The BMP is sized (and calculations provided) based on:
The ½” or 1” Water Quality Volume or
The equivalent flow rate associated with the Water Quality Volume and documentation is
provided showing that the BMP treats the required water quality volume.
The applicant proposes to use proprietary BMPs, and documentation supporting use of proprietary
BMP and proposed TSS removal rate is provided. This documentation may be in the form of the
propriety BMP checklist found in Volume 2, Chapter 4 of the Massachusetts Stormwater Handbook
and submitting copies of the TARP Report, STEP Report, and/or other third party studies verifying
performance of the proprietary BMPs.
A TMDL exists that indicates a need to reduce pollutants other than TSS and documentation showing
that the BMPs selected are consistent with the TMDL is provided.
Standard 5: Land Uses With Higher Potential Pollutant Loads (LUHPPLs)
The NPDES Multi-Sector General Permit covers the land use and the Stormwater Pollution
Prevention Plan (SWPPP) has been included with the Stormwater Report.
The NPDES Multi-Sector General Permit covers the land use and the SWPPP will be submitted prior
to the discharge of stormwater to the post-construction stormwater BMPs.
The NPDES Multi-Sector General Permit does not cover the land use.
LUHPPLs are located at the site and industry specific source control and pollution prevention
measures have been proposed to reduce or eliminate the exposure of LUHPPLs to rain, snow, snow
melt and runoff, and been included in the long term Pollution Prevention Plan.
All exposure has been eliminated.
All exposure has not been eliminated and all BMPs selected are on MassDEP LUHPPL list.
The LUHPPL has the potential to generate runoff with moderate to higher concentrations of oil and
grease (e.g. all parking lots with >1000 vehicle trips per day) and the treatment train includes an oil
grit separator, a filtering bioretention area, a sand filter or equivalent.
Standard 6: Critical Areas
The discharge is near or to a critical area and the treatment train includes only BMPs that MassDEP
has approved for stormwater discharges to or near that particular class of critical area.
Critical areas and BMPs are identified in the Stormwater Report.
swcheck • 04/01/08 Stormwater Report Checklist • Page 7 of 8
Massachusetts Department of Environmental Protection
Bureau of Resource Protection - Wetlands Program Checklist for Stormwater Report
Checklist (continued)
Standard 7: Redevelopments and Other Projects Subject to the Standards only to the maximum extent practicable
The project is subject to the Stormwater Management Standards only to the maximum Extent
Practicable as a:
Limited Project
Small Residential Projects: 5-9 single family houses or 5-9 units in a multi-family development
provided there is no discharge that may potentially affect a critical area.
Small Residential Projects: 2-4 single family houses or 2-4 units in a multi-family development
with a discharge to a critical area
Marina and/or boatyard provided the hull painting, service and maintenance areas are protected
from exposure to rain, snow, snow melt and runoff
Bike Path and/or Foot Path
Redevelopment Project
Redevelopment portion of mix of new and redevelopment.
Certain standards are not fully met (Standard No. 1, 8, 9, and 10 must always be fully met) and an
explanation of why these standards are not met is contained in the Stormwater Report.
The project involves redevelopment and a description of all measures that have been taken to
improve existing conditions is provided in the Stormwater Report. The redevelopment checklist found
in Volume 2 Chapter 3 of the Massachusetts Stormwater Handbook may be used to document that
the proposed stormwater management system (a) complies with Standards 2, 3 and the pretreatment
and structural BMP requirements of Standards 4-6 to the maximum extent practicable and (b)
improves existing conditions.
Standard 8: Construction Period Pollution Prevention and Erosion and Sedimentation Control
A Construction Period Pollution Prevention and Erosion and Sedimentation Control Plan must include the
following information:
Narrative;
Construction Period Operation and Maintenance Plan;
Names of Persons or Entity Responsible for Plan Compliance;
Construction Period Pollution Prevention Measures;
Erosion and Sedimentation Control Plan Drawings;
Detail drawings and specifications for erosion control BMPs, including sizing calculations;
Vegetation Planning;
Site Development Plan;
Construction Sequencing Plan;
Sequencing of Erosion and Sedimentation Controls;
Operation and Maintenance of Erosion and Sedimentation Controls;
Inspection Schedule;
Maintenance Schedule;
Inspection and Maintenance Log Form.
A Construction Period Pollution Prevention and Erosion and Sedimentation Control Plan containing
the information set forth above has been included in the Stormwater Report.
swcheck • 04/01/08 Stormwater Report Checklist • Page 8 of 8
Massachusetts Department of Environmental Protection
Bureau of Resource Protection - Wetlands Program Checklist for Stormwater Report
Checklist (continued)
Standard 8: Construction Period Pollution Prevention and Erosion and Sedimentation Control
(continued)
The project is highly complex and information is included in the Stormwater Report that explains why
it is not possible to submit the Construction Period Pollution Prevention and Erosion and
Sedimentation Control Plan with the application. A Construction Period Pollution Prevention and
Erosion and Sedimentation Control has not been included in the Stormwater Report but will be
submitted before land disturbance begins.
The project is not covered by a NPDES Construction General Permit.
The project is covered by a NPDES Construction General Permit and a copy of the SWPPP is in the
Stormwater Report.
The project is covered by a NPDES Construction General Permit but no SWPPP been submitted.
The SWPPP will be submitted BEFORE land disturbance begins.
Standard 9: Operation and Maintenance Plan
The Post Construction Operation and Maintenance Plan is included in the Stormwater Report and
includes the following information:
Name of the stormwater management system owners;
Party responsible for operation and maintenance;
Schedule for implementation of routine and non-routine maintenance tasks;
Plan showing the location of all stormwater BMPs maintenance access areas;
Description and delineation of public safety features;
Estimated operation and maintenance budget; and
Operation and Maintenance Log Form.
The responsible party is not the owner of the parcel where the BMP is located and the Stormwater
Report includes the following submissions:
A copy of the legal instrument (deed, homeowner’s association, utility trust or other legal entity)
that establishes the terms of and legal responsibility for the operation and maintenance of the
project site stormwater BMPs;
A plan and easement deed that allows site access for the legal entity to operate and maintain
BMP functions.
Standard 10: Prohibition of Illicit Discharges
The Long-Term Pollution Prevention Plan includes measures to prevent illicit discharges;
An Illicit Discharge Compliance Statement is attached;
NO Illicit Discharge Compliance Statement is attached but will be submitted prior to the discharge of
any stormwater to post-construction BMPs.
BAPPENDIX B
Based on USGS Topographic Map forEasthampton, MA Quadrangles. Revised 1979.Circles indicate 500-foot and half-mile radii
SITE LOCATION
¹0 1,000 2,000
Feet
1:24,000
V:\Projects\H\H1363\ClarionHotel_usgs.mxd
FIGURE 1SITE LOCATION MAP
Hospitality North23 Atwood DriveNorthampton, Massachustts
September 2013
H-1363
^_
¹0 1,000 2,000
Feet
1:24,000
V:\Projects\H\H1363\ClarionHotel_gis.mxd
Data source: Office of Geographic and EnvironmentalInformation(MassGIS), Commonwealth of Massachusetts Executive Office of Environmental Affairs.Circles indicate 500-foot and half-mile radii.Data valid as of October 2012.
FIGURE 2PRIORITY RESOURCE MAP
Hospitality North23 Atwood DriveNorthampton, Massachustts
W-1346
SITE LOCATION
LEGEND
September 2013
PowerlinePipeline
Limited Access HighwayMulti-Lane Highway, NOT Limited AccessOther Numbered HighwayMajor Road - CollectorMinor Street or Road
Public Surface Water Supply (PSWS)Inland Wetlands (MA DEP)Coastal Wetlands (MA DEP)Waterbodies
Track or Trail
Town BoundaryCounty Boundary
Train
Aquaduct
Major Drainage Basin
Sub Drainage Basin
Quad Sheet Boundary
((
Non-Potential Drinking Water Source Area - High YieldNon-Potential Drinking Water Source Area - Medium YieldPotentially Productive Medium Yield AquiferPotentially Productive High Yield AquiferEPA Designated Sole Source AquiferDEP Approved Wellhead Protection Area (Zone II)DEP Interim Wellhead Protection Area (IWPA)
Public Surface Water Supply Protection Area (Zone A)
NHESP Priority Habitats for Rare Species
Protected and Recreational Open SpaceArea of Critical Environmental Concern (ACEC)Solid Waste Landfill
Community Public Water Supply - Surface WaterCommunity Public Water Supply - GroundwaterNon-Community Non-Transient Public Water Supply
Non-Community Transient Public Water Supply
NHESP Certified Vernal Pools!Þ
!Þ
"
"TX
NHESP Estimated Habitats for Rare Wildlife
^_
UV5
UV5
UV5
UV5
UV5
UV5
§¨¦91
§¨¦91
§¨¦91
FIGURE 3ORTHOPHOTO MAP
Hospitality North23 Atwood DriveNorthampton, Massachustts¹0 100 200
Feet
1:2,400
V:\Projects\H\H1363\ClarionHotel_ortho.mxd
Based on MassGIS Color Orthophotography (April 2009)
SITE LOCATION
H-1363
September 2013
^_
ATWOOD DRIVE
ATWOOD DRIVE MT. TOM ROAD - ROUTE 5MANHAN ROAD
(A
.K
.A
.
MEADOW
ROAD)
INTERSTATE 91
INTERSTATE 9100 80'160'
SCALE IN FEET
GRAPHIC SCALE
N ATWOOD NORTH DEVELOPMENT
NORTHAMPTON, MASSACHUSETTS
FIGURE 4
EXISTING CONDITIONS
DRAINAGE AREA MAP
Tighe&Bond Consulting Engineers
www.tighebond.com
SCALE: 1"=80'DATE: DECEMBER 2016
SUBCATCHMENT BOUNDARY
LEGEND
STORMWATER FLOW PATH
AREA 1
AREA 2A
AREA 2B AREA 8
AREA 3
AREA 5
AREA 4
AREA 6
AREA 22
AREA 23
AREA 7
AREA 21
AREA 20
AREA 18
AREA 19
AREA 17
AREA 16
AREA 15
AREA 14B
AREA 14A
AREA 13
AREA 12
AREA 11
AREA 10
AREA 9BAREA 9AWETLAND AREA:
DESIGN POINT DP-1
DD
D
D
DD
DDDD
D
D
D
D
D
00 80'160'
SCALE IN FEET
GRAPHIC SCALE
N ATWOOD NORTH DEVELOPMENT
NORTHAMPTON, MASSACHUSETTS
FIGURE 5
PROPOSED CONDITIONS
DRAINAGE AREA MAP
Tighe&Bond Consulting Engineers
www.tighebond.com
SCALE: 1"=80'DATE: FEBRUARY 2017
SUBCATCHMENT BOUNDARY
LEGEND
STORMWATER FLOW PATH
AREA 24S
AREA 23S
AREA 20S
AREA 19S
AREA 18S
AREA 12S
AREA 11S
AREA 21S
AREA 10S
AREA 5S
AREA 4S
AREA 3S
AREA 1S
AREA 2S
AREA 22SAREA 22
AREA 23
AREA 21
AREA 20
AREA 18
AREA 19
AREA 17
AREA 16
AREA 15AREA 14SAREA 6SAREA 7SAREA 8SAREA 9SAREA 17S
AREA 15S
AREA 13S
A
R
E
A
1
6
S
AREA 29S AREA 25SAREA 26SAREA 27SAREA 28SAREA 32S
AREA 31SAREA 30S
WETLAND AREA:
DESIGN POINT DP-1
CAPPENDIX C
Hydrologic Soil Group—Hampshire County, Massachusetts, Central Part
(Atwood North Redevelopment Project)
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
12/15/2016
Page 1 of 446861104686160468621046862604686310468636046864104686110468616046862104686260468631046863604686410695540695590695640695690695740695790695840695890695940695990696040
695540 695590 695640 695690 695740 695790 695840 695890 695940 695990 696040
42° 18' 19'' N 72° 37' 39'' W42° 18' 19'' N72° 37' 17'' W42° 18' 8'' N
72° 37' 39'' W42° 18' 8'' N
72° 37' 17'' WN
Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 18N WGS84
0 100 200 400 600Feet
0 35 70 140 210Meters
Map Scale: 1:2,400 if printed on A landscape (11" x 8.5") sheet.
Warning: Soil Map may not be valid at this scale.
MAP LEGEND MAP INFORMATION
Area of Interest (AOI)
Area of Interest (AOI)
Soils
Soil Rating Polygons
A
A/D
B
B/D
C
C/D
D
Not rated or not available
Soil Rating Lines
A
A/D
B
B/D
C
C/D
D
Not rated or not available
Soil Rating Points
A
A/D
B
B/D
C
C/D
D
Not rated or not available
Water Features
Streams and Canals
Transportation
Rails
Interstate Highways
US Routes
Major Roads
Local Roads
Background
Aerial Photography
The soil surveys that comprise your AOI were mapped at 1:15,800.
Warning: Soil Map may not be valid at this scale.
Enlargement of maps beyond the scale of mapping can cause
misunderstanding of the detail of mapping and accuracy of soil line
placement. The maps do not show the small areas of contrasting
soils that could have been shown at a more detailed scale.
Please rely on the bar scale on each map sheet for map
measurements.
Source of Map: Natural Resources Conservation Service
Web Soil Survey URL: http://websoilsurvey.nrcs.usda.gov
Coordinate System: Web Mercator (EPSG:3857)
Maps from the Web Soil Survey are based on the Web Mercator
projection, which preserves direction and shape but distorts
distance and area. A projection that preserves area, such as the
Albers equal-area conic projection, should be used if more accurate
calculations of distance or area are required.
This product is generated from the USDA-NRCS certified data as of
the version date(s) listed below.
Soil Survey Area: Hampshire County, Massachusetts, Central
Part
Survey Area Data: Version 11, Sep 14, 2016
Soil map units are labeled (as space allows) for map scales 1:50,000
or larger.
Date(s) aerial images were photographed: Mar 28, 2011—Apr 18,
2011
The orthophoto or other base map on which the soil lines were
compiled and digitized probably differs from the background
imagery displayed on these maps. As a result, some minor shifting
of map unit boundaries may be evident.
Hydrologic Soil Group—Hampshire County, Massachusetts, Central Part
(Atwood North Redevelopment Project)
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
12/15/2016
Page 2 of 4
Hydrologic Soil Group
Hydrologic Soil Group— Summary by Map Unit — Hampshire County, Massachusetts, Central Part (MA609)
Map unit symbol Map unit name Rating Acres in AOI Percent of AOI
744A Hadley-Winooski-Urban
land complex, 0 to 3
percent slopes
B 15.9 100.0%
Totals for Area of Interest 15.9 100.0%
Description
Hydrologic soil groups are based on estimates of runoff potential. Soils are
assigned to one of four groups according to the rate of water infiltration when the
soils are not protected by vegetation, are thoroughly wet, and receive precipitation
from long-duration storms.
The soils in the United States are assigned to four groups (A, B, C, and D) and
three dual classes (A/D, B/D, and C/D). The groups are defined as follows:
Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly
wet. These consist mainly of deep, well drained to excessively drained sands or
gravelly sands. These soils have a high rate of water transmission.
Group B. Soils having a moderate infiltration rate when thoroughly wet. These
consist chiefly of moderately deep or deep, moderately well drained or well drained
soils that have moderately fine texture to moderately coarse texture. These soils
have a moderate rate of water transmission.
Group C. Soils having a slow infiltration rate when thoroughly wet. These consist
chiefly of soils having a layer that impedes the downward movement of water or
soils of moderately fine texture or fine texture. These soils have a slow rate of water
transmission.
Group D. Soils having a very slow infiltration rate (high runoff potential) when
thoroughly wet. These consist chiefly of clays that have a high shrink-swell
potential, soils that have a high water table, soils that have a claypan or clay layer
at or near the surface, and soils that are shallow over nearly impervious material.
These soils have a very slow rate of water transmission.
If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is
for drained areas and the second is for undrained areas. Only the soils that in their
natural condition are in group D are assigned to dual classes.
Rating Options
Aggregation Method: Dominant Condition
Component Percent Cutoff: None Specified
Hydrologic Soil Group—Hampshire County, Massachusetts, Central Part Atwood North Redevelopment Project
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
12/15/2016
Page 3 of 4
06052013 Test Pit Logs 01-05.doc • rev. 10/07 Form 11 – Soil Suitability Assessment for Stormwater Design • Page 1 of 6 Commonwealth of Massachusetts City/Town of Northampton Form 11 - Soil Suitability Assessment for Stormwater Design C. On-Site Review Deep Observation Hole Number: TP-01 Depth (in.) Soil Horizon/ Layer Soil Matrix: Color-Moist (Munsell) Redoximorphic Features (mottles) Soil Texture (USDA) Coarse Fragments % by Volume Soil Structure Soil Consistence (Moist) Other Depth Color Percent Gravel Cobbles & Stones 0-6 A 10YR/3/3 Sandy Loam 5 0 SBK Friable 6-132 Fill 1 2.5Y/5/3 Loamy Sand 5 0 Massive Friable 132-144 C1 7.5YR/4/1 132" 2.5Y/5/8 >5 Dense Fine Sandy Loam 0 0 Massive Friable firm in place Additional Notes: No weeping or standing water observed. Fill material was generally free of construction/demolition debris with the exception of a couple pieces of asphalt (1’x1’x2”) observed in the first 2’ of excavation. C1 was dense material with an expected low permeability.
06052013 Test Pit Logs 01-05.doc • rev. 10/07 Form 11 – Soil Suitability Assessment for Stormwater Design • Page 2 of 6 Commonwealth of Massachusetts City/Town of Northampton Form 11 - Soil Suitability Assessment for Stormwater Design C. On-Site Review Deep Observation Hole Number: TP-02 Depth (in.) Soil Horizon/ Layer Soil Matrix: Color-Moist (Munsell) Redoximorphic Features (mottles) Soil Texture (USDA) Coarse Fragments % by Volume Soil Structure Soil Consistence (Moist) Other Depth Color Percent Gravel Cobbles & Stones 0-6 A 10YR/3/2 Sandy Loam 5 0 SBK Friable 6-88 FILL 1 2.5Y/5/3 Loamy Sand 5 0 Massive Friable 88-105 C1 2.5Y/3/1 88 2.5YR/5/8 3 Organic Fine Loamy Sand0 0 Massive Friable Firm in Place 105-144 C2 2.5Y/5/3 Fine Loamy Sand 0 0 Massive Friable Additional Notes: No weeping or standing water observed. Fill material was 80% loamy sand with pockets of medium sand. No construction/demolition debris encountered in fill material. C1 material was dark gray color with strong organic odors. C1 was dense material with an expected low permeability. C2 material consisted mainly of fine loamy sand with pockets of fine sand. Soils were saturated at 144” deep. No distinct signs of redox were observed in the C2 layer.
06052013 Test Pit Logs 01-05.doc • rev. 10/07 Form 11 – Soil Suitability Assessment for Stormwater Design • Page 3 of 6 Commonwealth of Massachusetts City/Town of Northampton Form 11 - Soil Suitability Assessment for Stormwater Design C. On-Site Review Deep Observation Hole Number: TP-03 Depth (in.) Soil Horizon/ Layer Soil Matrix: Color-Moist (Munsell) Redoximorphic Features (mottles) Soil Texture (USDA) Coarse Fragments % by Volume Soil Structure Soil Consistence (Moist) Other Depth Color Percent Gravel Cobbles & Stones 0-8 A 10YR/3/2 Sandy Loam 5 0 SBK Friable 8-60 FILL 1 2.5Y/5/3 Loamy Sand 5 0 Massive Friable 60-108 FILL 2 2.5Y/6/2 Med Coarse Sand5 0 Single Grain Loose 108-136 C1 7.5YR/4/1 108” 2.5YR/8/8 >5 Dense Fine Sandy Loam 0 0 Massive Friable Firm in Place Additional Notes: No weeping or standing water observed. No construction/demolition debris encountered in fill material. C1 was dense material with an expected low permeability.
06052013 Test Pit Logs 01-05.doc • rev. 10/07 Form 11 – Soil Suitability Assessment for Stormwater Design • Page 4 of 6 Commonwealth of Massachusetts City/Town of Northampton Form 11 - Soil Suitability Assessment for Stormwater Design C. On-Site Review Deep Observation Hole Number: TP-04 Depth (in.) Soil Horizon/ Layer Soil Matrix: Color-Moist (Munsell) Redoximorphic Features (mottles) Soil Texture (USDA) Coarse Fragments % by Volume Soil Structure Soil Consistence (Moist) Other Depth Color Percent Gravel Cobbles & Stones 0-4 A 10YR/3/2 Sandy Loam 5 0 SBK Friable 4-62 FILL 1 7.5YR/5/2 Loamy Sand 5 0 Massive Friable 62-100 FILL 2 2.5Y/5/3 90” 5YR/5/4 3 Medium Sand 5 0 Single Grain Loose 100-144 C1 7.5YR/4/1 100” 5YR/5/4 >5 Dense Fine Sandy Loam 0 0 Massive Friable Wet Additional Notes: No weeping or standing water observed. Fill 1 material included approximately 25% construction/demolition debris (brick, mortar, rebar, metal pipe) by volume. Fill 2 material only had a few angular stone and bricks (3-4 pieces). C1 was dense material with an expected low permeability. C1 material was saturated at 132” deep. C1 material is no longer firm in place when saturated.
06052013 Test Pit Logs 01-05.doc • rev. 10/07 Form 11 – Soil Suitability Assessment for Stormwater Design • Page 5 of 6 Commonwealth of Massachusetts City/Town of Northampton Form 11 - Soil Suitability Assessment for Stormwater Design C. On-Site Review Deep Observation Hole Number: TP-05 Depth (in.) Soil Horizon/ Layer Soil Matrix: Color-Moist (Munsell) Redoximorphic Features (mottles) Soil Texture (USDA) Coarse Fragments % by Volume Soil Structure Soil Consistence (Moist) Other Depth Color Percent Gravel Cobbles & Stones 0-7 A 10YR/3/2 Sandy Loam 5 0 SBK Friable 7-82 FILL 1 7.5YR/5/2 Loamy Sand 5 0 Massive Friable 82-132 C1 7.5YR/4/1 82” 5YR/5/4 >5 Dense Fine Sandy Loam 0 0 Massive Friable Firm in Place Additional Notes: No weeping or standing water observed. Fill 1 material included approximately 50% construction/demolition debris (brick, mortar, rebar, metal pipe) by volume. C1 was dense material with an expected low permeability. C1 material was saturated at 100” deep. C1 material is no longer firm in place when saturated.
06052013 Test Pit Logs 01-05.doc • rev. 10/07 Form 11 – Soil Suitability Assessment for Stormwater Design • Page 6 of 6 Commonwealth of Massachusetts City/Town of Northampton Form 11 - Soil Suitability Assessment for Stormwater Design F. Certification I certify that I am currently approved by the Department of Environmental Protection pursuant to 310 CMR 15.017 to conduct soil evaluations and that the above analysis has been performed by me consistent with the required training, expertise and experience described in 310 CMR 15.017. Signature of Soil Evaluator Date Jeremy Cigal, Tighe & Bond, Inc. / #2870 Typed or Printed Name of Soil Evaluator / License # 11/2004 Date of Soil Evaluator Exam Field Notes: Date: June 5, 2013 Backhoe = CAT 420D (Seaboard Drilling) Weather: Sunny, 70 degrees See site plan for test pit locations
APPENDIX D
Stormwater Standards Calculations
Tighe & Bond, Inc.
2/20/2017
HOSPITALITY NORTH STORMWATER CALCULATIONS
Required Recharge Volume (Standard 3):
For Class B Soils: F = Target depth factor = 0.35 inch (entire site)
Impervious Area = 5.12 acres
Rv0 = F * Impervious Area = 32
505,643560*12.5*"12
1"*35.0 ftacre
ftacresft
Two sections of proposed impervious area do not drain to the infiltration basin,
therefore, a capture area adjustment must be calculated and applied to the required
recharge volume.
Capture Area Adjustment =CA= 03.113.012.5
12.5
acres
acres
I
I
onInfiltrati
Total
Rv=Rv0* CA = 33700,603.1*505,6 ftft= Required Recharge Volume
Recharge Time and Drawdown
Since infiltration occurs in each of the four basins, the following Equation from the
Massachusetts Stormwater Handbook was calculated using the basin volumes:
Timedrawdown = AreaBottomK
Vs
Vs = Storage Volume = 5580 ft3 (Rv – areas that flow to biofiltration basins)
K = 0.085 ft/hr (1.02 in/hr Rawls Rate for Sandy Loam)
Bottom Area = 2,679 ft2
Timedrawdown = hrft
ft
hrft 25679,2085.0
580,5
2
3
Required Water Quality Volume (Standard 4):
The Site is considered a LUHPPL. The Medical Office use generates over 1,000 vehicle
trips per day, and would therefore be classified as a LUHPPL. For purposes of this
report, the entire parking area (448 parking spaces and access drives) will be
considered a LUHPPL, which requires a Water Quality Depth = DWQ1 = 1”. Additionally,
building rooftop areas have been excluded from the calculations as they are not
subject to treatment requirements.
VWQ = DWQ * Impervious Area = 32151,15814,181*"12
1"*0.1 ftftft
Total VWQ = 15,151 cubic feet
Target Volume:
Target Volume is defined as the larger of Required Recharge Volume and Required
Water Quality Volume. Therefore, Target Volume = 15,151 ft3 (Required Water
Tighe & Bond, Inc.
2/20/2017
Quality Volume). Catch basin, water quality units, infiltration basin and bioretention
area volumes provided and required are summarized in the following table.
Recharge and Water Quality Volume Summary Table
Area, Structure Reference Recharge Volume (cf) Water Quality Volume
(cf)
Bioretention Basin-1 LINED – N/A 2,877
Bioretention Basin-2 LINED – N/A 394
Catch Basins* N/A 1,000
Water Quality Units N/A 2,151
Infiltration Basin 1 3,583 3,583
Infiltration Basin 2 6,192 6,192
Total Volume Provided 9,775 16,197
Volume Required 6,713 15,151
All volumes calculated are below the elevation of the outlet.
*All catch basins include a 4-foot deep sump, and a 4-feet in diameter. The project plans
indicate 20 catch basins are proposed, each having a water quality volume of 50 cf.
Mounding Analysis (Standard 4):
The Stormwater Handbook requires that the 72-hr mound after a 10-yr 24-hr storm
does not affect wetland resources or dewatering the basin. The Hantush Method,
recommended by the Stormwater Handbook was used with the following inputs:
Rectangular Basin Geometry: L x W = 128’ x 31.6’ (the rectangular area is equal to
actual basin bottom area and length:width ratio equal to actual basin average
length:width ratio.)
Time: T= 72 hours, from Stormwater handbook
Initial Saturated Thickness: hi = 0.8’. The difference between the seasonal high
ground water level (7.5’ below grade) and the low permeability layer at 8.3’ below
grade.
Percolation Rate: w10 = 0.0154 ft/hr (10-yr, 24-hr storm) and w100 = 0.026 ft/hr (100-
yr, 24-hr storm). Sample calculation:
hrft
hrt
Pw 0154.0"12
'1*24
"44.4
10
,
P = Total Precipitation in inches (10-yr, 24-hr storm)
t = duration of precipitation
Hydraulic Conductivity: K = 1.02 in/hr and K = 0.085 ft/hr (Rawls Rate, given in
Stormwater Handbook for Sandy Loam).
Tighe & Bond, Inc.
2/20/2017
Specific Yield: Sy = 20. The specific yield was estimated to be 20, since the specific
yield for silt is 18 and fine sand is 21 and it is likely that the amount of water drained
by gravity for a loamy sand will be between silt and fine sand. (Johnson, A.I. 1967.
Specific yield — compilation of specific yields for various materials. U.S. Geological
Survey Water Supply Paper 1662-D. 74 p.)
The calculation was performed using the Hantush Method Calculator at
http://www.groundwatersoftware.com/calculator_9_hantush_mounding.htm. The
Hantush method is referenced to: Hantush, M.S.(1967). Growth and Decay of
Groundwater-Mounds in Response to Uniform Percolation, Water Resources Research
vol. 3, no.1, pp 227-234. Web pages are attached.
Mounding Analysis Results:
Storm Event w Mounding (increase in
hydraulic head)
Effect on Wetlands or
Downstream?
10-yr, 24-hr W10 = 0.0154 ft/hr 0.055 ft None
100-yr, 24-hr W100 = 0.026 ft/hr 0.094 ft None
Treatment Train Calculations
INSTRUCTIONS:Non-automated: Mar. 4, 20081. Sheet is nonautomated. Print sheet and complete using hand calculations. Column A and B: See MassDEP Structural BMP Table2. The calculations must be completed using the Column Headings specified in Chart and Not the Excel Column Headings3. To complete Chart Column D, multiple Column B value within Row x Column C value within Row4. To complete Chart Column E value, subtract Column D value within Row from Column C within Row5. Total TSS Removal = Sum All Values in Column DLocation:ABCDETSS Removal Starting TSS Amount RemainingBMP1Rate1Load* Removed (B*C) Load (C-D)1.00Total TSS Removal =Separate Form Needs to be Completed for Each Outlet or BMP TrainProject:Prepared By:*Equals remaining load from previous BMP (E)Date:which enters the BMPTSS Removal Calculation WorksheetNon-automated TSS Calculation Sheet must be used if Proprietary BMP Proposed1. From MassDEP Stormwater Handbook Vol. 1Mass. Dept. of Environmental Protection
VINSTRUCTIONS:Version 1, Automated: Mar. 4, 20081. In BMP Column, click on Blue Cell to Activate Drop Down Menu2. Select BMP from Drop Down Menu3. After BMP is selected, TSS Removal and other Columns are automatically completed.Location: BCDEFTSS Removal Starting TSS Amount RemainingBMP1Rate1Load* Removed (C*D) Load (D-E)Infiltration Basin0.801.000.800.200.000.200.000.200.000.200.000.200.000.200.000.200.000.200.000.20Total TSS Removal =80%Separate Form Needs to be Completed for Each Outlet or BMP TrainProject:Atwood NorthPrepared By:TJG*Equals remaining load from previous BMP (E)Date:12/22/2016which enters the BMPTSS Removal Calculation WorksheetTreatment Train 1 - Infil. Basin 1Non-automated TSS Calculation Sheetmust be used if Proprietary BMP Proposed1. From MassDEP Stormwater Handbook Vol. 1Mass. Dept. of Environmental Protection
VINSTRUCTIONS:Version 1, Automated: Mar. 4, 20081. In BMP Column, click on Blue Cell to Activate Drop Down Menu2. Select BMP from Drop Down Menu3. After BMP is selected, TSS Removal and other Columns are automatically completed.Location: BCDEFTSS Removal Starting TSS Amount RemainingBMP1Rate1Load* Removed (C*D) Load (D-E)Bioretention Area0.901.000.900.100.000.100.000.100.000.100.000.100.000.100.000.100.000.100.000.10Total TSS Removal =90%Separate Form Needs to be Completed for Each Outlet or BMP TrainProject:Atwood NorthPrepared By:TJG*Equals remaining load from previous BMP (E)Date:12/22/2016which enters the BMPTSS Removal Calculation WorksheetTreatment Train 2 - Bioretention Basin 1Non-automated TSS Calculation Sheetmust be used if Proprietary BMP Proposed1. From MassDEP Stormwater Handbook Vol. 1Mass. Dept. of Environmental Protection
VINSTRUCTIONS:Version 1, Automated: Mar. 4, 20081. In BMP Column, click on Blue Cell to Activate Drop Down Menu2. Select BMP from Drop Down Menu3. After BMP is selected, TSS Removal and other Columns are automatically completed.Location: BCDEFTSS Removal Starting TSS Amount RemainingBMP1Rate1Load* Removed (C*D) Load (D-E)Infiltration Basin 0.801.00 0.80 0.200.000.20 0.00 0.200.000.20 0.00 0.200.000.20 0.00 0.200.000.20 0.00 0.20Total TSS Removal =80%Separate Form Needs to be Completed for Each Outlet or BMP TrainProject:Atwood NorthPrepared By:TJG*Equals remaining load from previous BMP (E)Date:12/22/2016which enters the BMPTSS Removal Calculation WorksheetTreatment Train 3 - Infil. Basin 2Non-automated TSS Calculation Sheetmust be used if Proprietary BMP Proposed1. From MassDEP Stormwater Handbook Vol. 1Mass. Dept. of Environmental Protection
VINSTRUCTIONS:Version 1, Automated: Mar. 4, 20081. In BMP Column, click on Blue Cell to Activate Drop Down Menu2. Select BMP from Drop Down Menu3. After BMP is selected, TSS Removal and other Columns are automatically completed.Location: BCDEFTSS Removal Starting TSS Amount RemainingBMP1Rate1Load* Removed (C*D) Load (D-E)Bioretention Area0.901.000.900.100.000.100.000.100.000.100.000.100.000.100.000.100.000.100.000.10Total TSS Removal =90%Separate Form Needs to be Completed for Each Outlet or BMP TrainProject:Atwood NorthPrepared By:TJG*Equals remaining load from previous BMP (E)Date:12/22/2016which enters the BMPTSS Removal Calculation WorksheetTreatment Train 4 - Bioretention Basin 2Non-automated TSS Calculation Sheetmust be used if Proprietary BMP Proposed1. From MassDEP Stormwater Handbook Vol. 1Mass. Dept. of Environmental Protection
VINSTRUCTIONS:Version 1, Automated: Mar. 4, 20081. In BMP Column, click on Blue Cell to Activate Drop Down Menu2. Select BMP from Drop Down Menu3. After BMP is selected, TSS Removal and other Columns are automatically completed.Location: BCDEFTSS Removal Starting TSS Amount RemainingBMP1Rate1Load* Removed (C*D) Load (D-E)Bioretention Area0.901.000.900.100.000.100.000.100.000.100.000.100.000.100.000.100.000.100.000.10Total TSS Removal =90%Separate Form Needs to be Completed for Each Outlet or BMP TrainProject:Atwood NorthPrepared By:TJG*Equals remaining load from previous BMP (E)Date:12/22/2016which enters the BMPTSS Removal Calculation WorksheetTreatment Train 5 - Bioretention Basin 1Non-automated TSS Calculation Sheetmust be used if Proprietary BMP Proposed1. From MassDEP Stormwater Handbook Vol. 1Mass. Dept. of Environmental Protection
VINSTRUCTIONS:Version 1, Automated: Mar. 4, 20081. In BMP Column, click on Blue Cell to Activate Drop Down Menu2. Select BMP from Drop Down Menu3. After BMP is selected, TSS Removal and other Columns are automatically completed.Location: BCDEFTSS Removal Starting TSS Amount RemainingBMP1Rate1Load* Removed (C*D) Load (D-E)Infiltration Basin0.801.000.800.200.000.200.000.200.000.200.000.200.000.200.000.200.000.200.000.20Total TSS Removal =80%Separate Form Needs to be Completed for Each Outlet or BMP TrainProject:Atwood NorthPrepared By:TJG*Equals remaining load from previous BMP (E)Date:12/22/2016which enters the BMPTSS Removal Calculation WorksheetTreatment Train 6 - Infil. Basin 1 & 2 (Direct entry)Non-automated TSS Calculation Sheetmust be used if Proprietary BMP Proposed1. From MassDEP Stormwater Handbook Vol. 1Mass. Dept. of Environmental Protection
Hydrologic Calculations
Not Included in this submission
EAPPENDIX E
STORMWATER MANAGEMENT SYSTEM OPERATION AND
MAINTENANCE PLAN
Hospitality North
Atwood Drive
Northampton, Massachusetts
February 2017
Prepared for:
Atwood Drive, LLC
Table of Contents Tighe&Bond
i
Section 1 Introduction
Section 2 Ownership and Responsibilities
Section 3 General BMPs
3.1 Good Housekeeping ...................................................................... 3-1
3.2 Preventative Maintenance .............................................................. 3-1
3.3 Management of Run-off ................................................................. 3-1
3.4 Sediment and Erosion Control ........................................................ 3-1
3.5 Snow Management ....................................................................... 3-2
3.6 Inspections .................................................................................. 3-2
3.6.1 Vegetated Surfaces ............................................................. 3-2
3.6.2 Deep-Sump, Hooded Catch Basins ........................................ 3-2
3.6.3 Surface Infiltration Basin ..................................................... 3-2
3.6.4 Rain Gardens ..................................................................... 3-2
Section 4 Operation and Maintenance Log Form
J:\H\H1363\Atwood North\Permits\Stormwater\December 2016\Appendix E - O&M\Stormwater_OM_Atwood
North.docx
Tighe&Bond
Stormwater Management System
Operation and Maintenance Plan 1-1
Section 1
Introduction
The following Long-Term Operations and Maintenance Plan has been prepared for the
stormwater management system at the proposed Atwood North Redevelopment on
Atwood Drive in Northampton, Massachusetts. The purpose of the plan is to provide
guidance and procedures for proper stormwater management following construction
completion.
The proposed project has been designed in compliance with the Massachusetts
Department of Environmental Protection (MassDEP) Stormwater Standards to maintain or
improve stormwater runoff quality and quantity.
Tighe&Bond
Stormwater Management System
Operation and Maintenance Plan 2-1
Section 2
Ownership and Responsibilities
Atwood Partners, LLC (Atwood) is responsible for maintaining and servicing the proposed
stormwater management system and its appurtenances post construction. The property
is owned by Atwood Drive, LLC.
During construction the contractor will be responsible for stormwater management system
maintenance.
Property Owner:
Atwood Drive, LLC
200 Silver Street
Agawam, MA 01030
Maintenance Contact:
Development Associates
200 Silver Street, Suite 201
P.O. Box 528
Agawam, MA 01001
Tighe&Bond
Stormwater Management System
Operation and Maintenance Plan 3-1
Section 3
General BMPs
Prior to the start of construction, the site will be inspected to document current conditions
and areas identified as needing maintenance, if any, will be addressed as appropriate.
The site should continue to be inspected regularly for erosion and to ensure the
stormwater system is operating as designed. Any erosion to the land surface should be
stabilized and repaired immediately upon discovery.
The following items described are the general Best Management Practices (BMPs) to be
implemented for the proposed Atwood North Redevelopment Project.
3.1 Good Housekeeping
The goal of the good housekeeping policy is to keep the site in a clean orderly condition.
A disorderly site can lead to improper materials management, and can reduce the
efficiency of any response to potential pollution problems.
The following good housekeeping measures will be followed at the site to aid in pollution
prevention:
Promptly clean and remove any spills or contamination from vehicles.
Perform preventative maintenance on all equipment and on the structural components
of the stormwater system.
3.2 Preventative Maintenance
Preventative maintenance is an important factor in minimizing the release of pollution
from the site. Preventative maintenance for this project will consist of primarily equipment
maintenance.
It is important that all of the equipment used to access the site and perform routine
maintenance of the facilities undergo routine maintenance and service so that fluid leaks
are managed. Any equipment exhibiting fluid leaks will be repaired or removed from the
site and repaired prior to returning to service.
3.3 Management of Run-off
The stormwater collected from the paved parking areas will sheet flow into the deep-sump
catch basins. From there it is directed into a series of manholes that discharge into water
quality units that direct the water into the proposed infiltration basins. The clean run-off
from the building roofs will be discharged directly into the wetlands.
3.4 Sediment and Erosion Control
Straw wattles and siltation fencing will be used during construction of the proposed work
area and silt sacks will be used in the adjacent catch basins located in paved areas. This
will minimize sediment collection in the stormwater management system and protect all
Tighe&Bond
Stormwater Management System
Operation and Maintenance Plan 3-2
wetland areas adjacent to the project. The straw wattles and siltation fence locations are
shown on the Demolition and Erosion Control plan included in the Permit Plan set. Once
construction is complete and vegetation is established, the straw wattles, silt fence and
silt sacks will be removed.
3.5 Snow Management
Snow removal will only occur along the proposed access roads, parking spaces and
walkways. Snow storage should not be in or adjacent to wetland areas nor block drainage
to surface inlets (catch basins).
3.6 Inspections
Inspections will be performed in accordance with the Massachusetts Department of
Environmental Protection (MassDEP) Stormwater Handbook. The following items will be
evaluated during each inspection:
3.6.1 Vegetated Surfaces
All vegetative surfaces will be observed to identify locations of settlement, erosion and
other impacts from the building and parking lot construction.
3.6.2 Deep-Sump, Hooded Catch Basins
Deep sump catch basins should be inspected at least four times per year. The Visual
inspection should ascertain that the catch basin is functioning properly (i.e. no blockages
or obstructions to the outlet and/or hood) and to measure the amount of solid materials
that have accumulated in the sump. This can be done with a calibrated dipstick, tape
measure or other measuring instrument so that the depth of deposition in the sump can
be tracked. Inspections should be completed visually from the ground level. If further
investigation is warranted that requires entering the structure, all applicable Confined
Space Entry safety regulations and procedures must be followed per 29 CFR 1910.146.
Deep sump catch basins should be cleaned four times per year or whenever the depth of
the sediment is greater than or equal to one half the depth from the bottom of the invert
of the lowest pipe in the basin. Cleanings should also be conducted at the end of the
foliage and snow-removal seasons. Clamshell buckets can be used to remove sediment.
However, vacuum trucks will remove more trapped sediment, are more expedient, and
are less likely to damage hoods on outlet pipes. Disposal of sediment removed from catch
basins must be disposed of in accordance with local, state and federal requirements.
3.6.3 Surface Infiltration Basin
Subsurface infiltration systems should be inspected bi-annually for standing water. If
standing water is observed for longer than 72 hours, a pump should be placed in the basin
and discharged through the outlet pipe. After the system is dewatered, it should be
observed by a Professional Engineer. A Professional Engineer should provide an opinion
as to why the infiltrations system is no draining and provide recommendations to restore
infiltration capacity to the system. Additionally, subsurface infiltration systems shall be
observed to identify depths of sediment and occurrence of debris which would impact
functionality.
Tighe&Bond
Stormwater Management System
Operation and Maintenance Plan 3-3
3.6.4 Bioretention Areas
Rain Gardens (Bioretention Areas) should be inspected monthly for the first year, quarterly
in subsequent years. Rain Garden areas will be observed for signs of erosion of side
slopes, poor infiltration and vegetative health. Remove and replace dead vegetation twice
per year in the spring and fall. Soil media shall be replaced in the event of poor infiltration
(i.e. when full infiltration does not occur with 72 hours). Pretreatment devices shall be
observed for sediment build up, structural damage and standing water.
3.6.5 Structural Water Quality Units
Structural Water Quality Units (WQU) will be observed in accordance with manufacturer
recommendations. Units are to be cleaned as directed by the manufacturer.
3.6.6 Stormwater System Outfalls
System outfalls should be inspected twice a year as well as after every major storm, for
slope integrity, soil moisture, vegetated health, soil stability, soil compaction, soil erosion,
ponding and sediment accumulation. If the rip rap has been displaced, undermined or
damaged, it should be replaced immediately. The channel immediately below the outlet
should be checked to see that erosion is not occurring. The downstream channel will be
kept clear of obstructions, such as fallen trees, debris, leaves and sediment that could
change flow patterns and/or tailwater depths in pipes. Repairs must be carried out
immediately to avoid additional damage to the outlet protection apron
Inspections shall be logged using the Inspection Forms provided in Section 4.
Tighe&Bond
Stormwater Management System
Operation and Maintenance Plan 4-1
Section 4 Operation and Maintenance Log
Form
Date:
Person conducting Inspection:
Reason for Inspection (Routine / Significant Rainfall):
Stormwater Management System Components:
Vegetated Surface
Component inspected during this inspection
Any Repair Necessary
Other Comments
Deep-Sump Hooded Catch Basins
Component inspected during this inspection
Any Repair Necessary
Other Comments
Infiltration Basins
Component inspected during this inspection
Any Repair Necessary
Other Comments
Bioretention Basins
Component inspected during this inspection
Any Repair Necessary
Other Comments
Structural Water Quality Units
Component inspected during this inspection
Any Repair Necessary
Other Comments
Culvert and Stone End Protection
Component inspected during this inspection
Any Repair Necessary
Other Comments
Tighe&Bond
Stormwater Management System
Operation and Maintenance Plan 5-2
Section 5
Estimated O&M Budget
The following estimated O&M Budget includes the inspections and maintenance activities
previously described on an annual basis.
Maintenance
Component Frequency Unit Cost Annual Cost
Vegetated Surfaces 4 $100 $400
Driveway and Walkway
Sweeping 4 $250 $1,000
Catch Basin Inspection 4 $250 $1,000
Catch Basin Sediment
Removal 2 $2,000 $4,000
Structural Water Quality
Units Inspection 12 $100 $1,200
Structural Water Quality
Units Cleaning 4 $1,000 $4,000
Rain Garden Inspections 12 $100 $1,200
Rain Garden
Maintenance 2 $500 $1,000
System Outfalls 2 $250 $500
Total Annual Estimated Budget $14,300
J:\H\H1363\Atwood North\Permits\Stormwater\December 2016\Appendix E - O&M\Stormwater_OM_Atwood
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DD
D
D
DD
DDDD
D
D
D
D
D
00 80'160'
SCALE IN FEET
GRAPHIC SCALE
N ATWOOD NORTH DEVELOPMENT
NORTHAMPTON, MASSACHUSETTS
FIGURE 1
OPERATION & MAINTENANCE PLAN
INSPECTION LOCATION PLAN
Tighe&Bond Consulting Engineers
www.tighebond.com
SCALE: 1"=80'DATE: FEBRUARY 2017
DEEP-SUMP CATCH BASINSBIORETENTION BASIN
INFILTRATION BASINS
BIORETENTION BASIN
STRUCTURAL WATER QUALITY UNITS
STRUCTURAL WATER QUALITY UNITS DEEP-SUMP CATCH BASINS
FAPPENDIX F
Draft Stormwater Pollution Prevention
Plan
Not Included in this submission
G
APPENDIX G
Illicit Discharge Statement
Not Included in this Submission