38A-050 (28) Oa THA 403,O CITY OF NORTHAMPTON,MASSACHUSETTS
? '°' ~ DEPARTMENT OF PUBLIC WORKS
►,A`W...�1 . 125 Locust Street
i42 .1?—;:. " Northampton, MA 01060
1 I/v
413-587-1570
Fax 413-587-1576
Edward S. Huntley, P.E.
Director
January 30, 2012
Mr.Jay P. Viamari, P.E.
Project Manager
Tighe&Bond
53 Southampton Road
Westfield, MA 01085
Re: Kollmorgen- Stormwater Permit—Remaining Compliance Issues
Dear Mr. Viamari:
The Northampton Department of Public Works(DPW)has reviewed the documents listed below for
compliance with the Stormwater Management Permit issued on June 10, 2009 by the DPW for the
Kollmorgen Electro-Optical Facility:
a. Kollmorgen Electro-Optical Headquarters at Village Hill, Record Plans, Sheets 1-17, revision
dated 8/02/2011, stamped by Joseph P. Viamari, Jr., P.E. and Francis J. Hoey III,Tighe& Bond,
Inc.
b. Kollmorgen Drainage System, Letter and attached Table 1 Water Quality Volume Provided,
dated December 2, 2011, from Jay P. Viamari, P.E., Tighe & Bond, Inc.
c. Revised Stormwater Report including Table 2 Peak Rates for DP-4 (Basin 6) and Table 3 Peak
Rates for DP-5 (Basin 5),submitted electronically by Jay Viamari, P.E.,Tighe& Bond, Inc,
dated January 20,2012.
d. Revised Stormwater HydroCAD Report East and Stormwater HydroCAD Report West for
Kollmorgen,dated 1/19/2012, submitted electronically by Jay Viamari, P.E.,Tighe&Bond, Inc.
After review of the documents listed above and inspection by the DPW of the Kollmorgen site during
and after construction of the project(most recently January 26&27,2012),the DPW finds that except
for the items listed below the project is currently in compliance with the requirements of the Stormwater
Management Permit and the Northampton Stormwater Management Ordinance. The following
outstanding items must be addressed in order for the DPW to approve the construction of the stormwater
management system in accordance with approved plans and specifications:
Recharge Volume Inadequate
Documentation provided by Jay Viamari, P.E., Tighe& Bond indicates that 3,920 cubic feet of recharge
(water quality)volume was constructed at the Kollmorgen site. During site inspections during and after
construction of the recharge areas, DPW staff has found on at least three occasions that one of the
Pg.1/3
recharge areas(catch basin 19 on sheet 6 of the plans) retains water up to the catch basin grate for
periods greater than 72 hours following a rain event and does not appear to infiltrate into the ground in
accordance with the approved design. A recharge area is required to infiltrate within 72 hours so that the
recharge volume is available for future storm events. Based on the findings of the DPW inspections,the
volume of the recharge area near catch basin 19 cannot be included in the water quality volume total.
The DPW estimates the actual built and functioning recharge volume on the site is 3,385 cubic feet,a
recharge volume far less than the 6,878 cubic feet approved in the project plans and calculations. The
constructed volume is also less than the minimum volume of 3,630 cubic feet calculated by Tighe&
Bond to be the required recharge volume for Standard 3 of the Massachusetts Stormwater Management
Standards.
Erosion and Sediment Control
The grass channels and bioretention areas in the parking lot continue to show signs of erosion and
sedimentation due to erosive flows through these structures without effective stabilization. During site
inspections,DPW staff has noted that gullies have formed in the grass swales, sediment has been
deposited in bioretention areas, and the wood mulch has floated to and into the catch basins. The owner
has taken steps to reduce these problems by adding plants, stone pads, soil, mulch and installing wire
fences to keep the mulch out of the catch basins. Additional measures are necessary to ensure that the
grass swales and bioretention areas continue to function as designed. The DPW requests that the owner
stabilize these structures. In addition,Tighe& Bond must certify that both the swales and bioretention
areas are functioning according to the design and in accordance with the Stormwater Operation,
Maintenance,and Inspection Agreement that was recorded for the project.
Record Plans
The DPW has reviewed the Record Plans and finds that the Stormwater Management System was not
constructed in compliance with the Stormwater Mangement Permit issued for the project for the reasons
detailed above. Please submit final Record Plans for our approval that include all changes made to the
stormwater system that were undertaken to address the issues described above. Record Plans must
include a professional engineer stamp with signatures and dates that are consistent with the latest
revision dates on the record plans.
Next Steps
Please submit for our approval,a plan to address the issues discussed above. The stormwater
management system will need to be constructed to meet the recharge volumes originally designed by
Tighe& Bond and approved in the Stormwater Mangement Permit. The reconstruction of the
stormwater system at Kollmorgen necessary to bring it into compliance could include excavation of
existing bioretention areas, adjustment of the elevation of catch basin grates, construction of additional
recharge systems, or other measures.
Pg.213
If there are questions regarding this information please contact Doug McDonald at the DPW(587-1582).
Sincerely,
^'N•vl
ames R. La ila,P.E.
City Engineer
cc.Andrew Crystal,LEED AP,Western Builders
Charlene Pellegrino,VP,Kollmorgen Electro Optical
John Weatherwax,Kollmorgen
Louis Hasbrook,Northampton Building Department
Northampton Planning Board
Northampton Conservation Commission
Pg.3/3
I- ' ,/,\ ( ..3
47i-LA8_—r 1/.
DECIDUOUS SHRUBS
I
L-90 IV----1
•
-----5-15C. /.... i - I ' I I • ••'•`-:-.• " c---, NATIVE GRASS SPECIES Afilk ';
' — •I\ II - I I-I , ' ' I :"..•:-.•••••••1- 4,- - SEE PLAN AND
, , : 1 , . i . • • - . • 9H
ii
PLANT SCHEDULE
/
BIOSWALE GRASSES AI
Ii!* - SEE PLAN AND
1/ .--'', ,,
ithif,,,,J i 9G 9H
IGC ' 0, , ' PLANT SCHEDULE
- •
• .
r EXTENTS OF RETENTION,
orr AREA SEED/MIX1111 NOTES
N,,,
. 41 ' i r_,'A 9H 1. FURNISH AND INSTALL PLANTINGS IN LOCATION AND
74._1"..._ I.i : ' '''' QUANTITIES AS INDICATED ON DRAWINGS
/ ' 1 AR 1 i 2. CONTRACTOR SHALL ASSUME THAT ALL DISTURBED
..-...
r t, , "iff - 1, ,QA ' AREAS SHALL BE SEEDED AS PER SPECIFICATIONS.
3. CONTRACTOR IS RESPONSIBLE FOR THE REMOVAL OF
ALL INVASIVE TREE IDENTIFIED IN THE SPECIFICATIONS
WITHIN THE EXTENTS OF THE PROJECT LIMITS.
PLANT LIST
MIN.
SYM. QTY. BOTANICAL NAME COMMON NAME SIZE NOTE —
DECIDUOUS SHADE TREES
-,
/ ' AR 34 Acer rubrum Red Maple 2.5 cal. 1/3 shall be clump form K
' BN 26 Betula nigra River Birch 14 HT. clump form E
FG B Fagus grandifolia American Beech 3.5" cal.
NS 23 Nyssa sylvatica Black Tupelo 2.5" cal.
/
QA 5 Quercus bicolor Swamp Oak 25 gal. 1.75" cal. / pot in pot
OR 7 Quercus rubra Red Oak 25 gal. 1.75" cal. / pot in pot
EVERGREEN TREES
JV 44 Juniperus Virginians Eastern Red Cedor 10 height
JVE 22 Juniperus Virginians 'Emerald Sentinel' Emerald Sentinel Cedar 6-7' height
, • PG 3 Picea glauca White Spruce 10 height Vi
PS 11 Pinus strobus Eastern White Pine 10' height Nc
ORNAMENTAL TREES
M
AL 22 Arneianchier I aevis Allegheny Shadbush — multistem 6--7' heigh
1
SA 14 Sassafras albidum SaiJsatra.s 8' height
'','' • ' '' SHRUBS/GROUNDCOVER.S
.I CA 50 Clethra alnifolia 'Hummingbird' Hummingbird Surnmersvreet 24" height -
CO 525 Comptonia peregrine Sweet Fern 18" height
CSK 80 Cornus sericea Redtwig Dogwood 24" height
IGC 113 Ilex globra 'Shamrock' Shamrock Compact lnkberry 30" height
, I
IVS 32 Ilex verticillata 'Red Sprite' Red Sprite Winterberry 1 24" height
11----
' RA 948 Rhus arornatico 'Gro—Low' Gro—Low Sumac 1 18" height bare root, 36" o.c.
RT 53 Rhus typhina Stoghorn Sumac 36" height
VD 18 Viburnum dentatum Arrowwood Viburnum 5-6' height
----
VT 14 Viburnum trilobum Americas Crailberrybush 30" height
„,.. .................. ...
EllOSW LE/RAINGARDEN PLANTS/GRASSES Maik
PRO
CKF 40 Calarnogrostis x acutifolia 'Karl Foerster' Feather Reed Grass No.2 Cont. FILE
r—
,. CP 12900 Carex pensylvanica Pennsylvania Sedge 2" plug 12" o.c. oRA
CRE
IV 1095 Iris versicolor Blue Flag 2" plug 12" G.C.
APP
PV 1203 Panicurn virgatum Switch Grass i 2" plug 12" o.c.
SS 2087 Schyzachyriurn scoparium I ittle Blue Stern ' 2" plug 12" o.c. PL
Ssp 1123 SOLIDAGO species juncea, nemoralis, rugosa Goldenrod Speciss 2" plug 12" o.c.
UL 2672 Uniola latifolia (Chasmanthium latifolium) Northern Sea Oats 2" plug I 12" 0,p, SC/