HomeMy WebLinkAbout2026/04/21 - Response to 2nd Stormwater Peer Review - - i
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April 21, 2026
File No. 101015.00
Town of North Andover- Planning Board
120 Main Street
North Andover MA 01845
(978) 688-9500
Re: Response to Town Comments and Peer Review Comments 2
203 Turnpike Street Solar Carport
Tax Map 024.0-0028-0003.B
203 Turnpike Road - North Andover MA
On behalf of AC Development LLC (Owner) Nobis Group (Nobis) is submitting this response to
the Town of North Andover Public hearing comments and the Horsley Witten Group peer review
comments 2 dated April 3, 2026 for the proposed project located at 203 Turnpike Street in North
Andover MA. Comments are shown below as black italicized font and responses are shown in
"bold blue font".
Town of North Andover Public Hearing Comments
• The travel ways are a concern to the planning board. Please add width dimensions to the
aisleways adjacent to the Carports.
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Response: Dimensions s ,,,en added to the C-1 Site plan. that show a 24 foot drive aisle
'between the Carports. "'r e space 'between t. existing es are r t,,,,r than ,,,,t.
Addi'fionally,the Carport product s been selectedwith the current.widths f the r
ports. See attached.
• Traffic patterns on the site are a mess. Please add `One way" directional arrows were
appropriate.
One . traffic 'Pavement marking h ..,,,, e . added to the - i t,,,, Plan.
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• The planning board would like to see a section of comparable structures. Please provide
an example.
Response-. The r rt components havebeenselected. tt e . r the car port product
t
documents.
• Per the previous peer review comments, please add street sweeping to the O&M plan to
provide additional treatment on site.
Response: Streets sweeping has be„gin add to the operation. and maintenancerequested
t peer r re.i,,, ��Ww. tr t sweepng wiell be requl*red t least once a year, i all i*n Aprid
after snow melt, to clean and. clear debrl*s fromthe pavement.
North Andover Fire Department
Can you request the actual measurements (widths) of these access routes? I definitely would like
to know the distance between the carport and the island. I also want 25ft between the buildings
and our ladder truck when it is deployed to ensure an acceptable angle for any ladder operation.
Again, I think there is probably a 25 ft distance already, but I would want to see the actual
measurement on a submitted plan.
Response,: A dimensi onto the listand. -to the car port has been added.t -the plan. A dihnensi*on
from the 'b-ui*ldl*ng to the carport ,,,, added also. Eachl en.smeets the
min.im.-um requirements r width.
North Andover Sewer
One of the structures is to be built over the Town's sewer easement. Normally a permenant
structure is not allowed, but in this case I believe we could still access the sewer line under the
proposed structure,which is fairly open. One support is shown on the edge of the easement and
it should be moved several feet outside the easement so we can have betteraccess to the sewer if
needed.
Response-. The u„ „ rt to the carport hasbeen shi*fted 9 feet to the southeast whl*ch moves it
out of the sewer easement.
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Stormwater Management Design Peer Review
1. Standard 1:No new stormwater conveyances (e.g., outfalls) may discharge untreated
stormwater directly to or cause erosion in wetlands or waters of the Commonwealth.
a. The Applicant has analyzed the pre- and post-development stormwater runoff to two
points of analysis(POA).
(1) POA-1 is an existing 12-inch drainpipe that outfalls into the wetland resource
area on the west corner of the parcel. Wetland flag series 1 B though 14B.
(2) POA-2 is an existing 12-inch drainpipe that outfalls into the wetland resource
area on the south corner of the parcel. Wetland flag series 1 D through 12D.
April 3, 2026:No further action is requested
Response: Noted
b. HW recommends that the Applicant confirm that the two outfalls are not currently
causing erosion in wetlands or waters of the Commonwealth.
April 3, 2026: The Applicant has confirmed that the existing site is not currently
causing erosion at either outfall.HW would not expect the post-development
conditions to impact the existing outfalls. No further action is requested
Response: Noted
2. Standard 2: Stormwater management systems shall be designed so that post-development peak
discharge rates do not exceed pre-development peak discharge rates.
a. The Applicant has illustrated that the post-development stormwater runoff will be
identical to the pre-development runoff. The Applicant is not altering the impervious
surface within the parking lot and has not proposed any detention or retention stormwater
practices. No further action is requested.
April 3, 2026:No further action is requested.
b. HW recommends that the Applicant clarify which direction the solar panels will pitch. It
appears that the downgradient side of the panels will be on the east side.HW recommends
that for clarity the Applicant include a note on the Site Plan.
April 3, 2026: The Applicant has stated that the solar panels will be pitched to the
southwest. This appears to be reasonable for the two sets of panels closest to
Building B. However, the panels closest to Building A will pitch onto the adjacent
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retaining wall.HW recommends that the Applicant confirms this is the intention
and that the retaining wall will not be compromised.
c. Per§250-22 B. (5)(b) and§250-23 A. (1) of the North Andover Stormwater Regulations,
Low-Impact development(LID)site planning and design strategies must be implemented
to the maximum extent feasible. HW recommends that the Applicant document any LID
options it considered within the Project Area.
April 3, 2026: The Applicant included in its response letter a list of LID practices
that were considered and eliminated as not being feasible.No further action is
requested.
d. In accordance with §250-22 B. (5)(c), HW recommends that the Applicant identify the
watershed basin and the downgradient water body that stormwater from the project site
discharges into.
April 3, 2026: The Applicant has noted that the downgradient water body is the
Shawsheen River. No further action is requested.
e. In accordance with§250-23 E. (19), the Applicant must utilize the 24-hour rainfall data
taken from National Oceanic and Atmospheric Administration (NOAA)Atlas 14 for the
rainfall precipitation depths. The Applicant has used the Cornell Extreme Precipitation
Rates Rainfall values, which are similar.
April 3, 2026:No further action is requested.
f HW recommends that the Applicant use a grass and woods surface condition of`good"
instead of`fair." HW understands that this suggestion will not have any impact on the
design, as the existing and proposed conditions are identical.
April 3, 2026: The Applicant has updated the Existing and Proposed HydroCAD
model using a surface condition of`good"for woods. No further action is
requested.
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Response-. Standard. 2 Response
Noteda.
. . The existingr et flows storm-water runoff to the existingwall.
In generalr stormwater runoff Willbe introduced. r .
'The existingbituminous has been pav-ed. and sealed up to the wall. No impact to
l s anticipated.
.
Noted
Noted
Notede.
. Noted
3. Standard 3 requires that the annual recharge from post-development shall approximate annual
recharge from pre-development conditions.
a. The Applicant has illustrated that the post-development annual recharge will be identical
to the pre-development recharge. The Applicant is not increasing or decreasing the
impervious surface within the parking lot. No further action is requested.
April 3, 2026:No further action is requested.
�,�:�,., sp;, III .se,: Noted.„t ..
4. Standard 4 requires that the stormwater system be designed to remove 80%Total Suspended Solids
(TSS) and to treat 1-inch of volume from the impervious area for water quality.
a. The Applicant has proposed to add hooded outlets (Eliminators) to the existing catch
basins to improve the TSS removal obtained.HW recommends that the Applicant confirm
that the existing catch basins have 4-foot-deep sumps.
April 3, 2026: The Applicant has noted that the catch basins require maintenance
to confirm the depth of the sumps. The Planning Board may choose to require
confirmation of the catch basin cleaning as a condition of approval.
b. In Section 1 of the Stormwater Operation &Maintenance Plan the Applicant notes that
riprap overflow controls will be placed at the outlets to provide energy dissipation. HW
recommends that the Applicant confirms if any riprap is proposed at the existing outfalls.
April 3, 2026: The Applicant has removed this statement.No further action is
requested.
c. HW recommends that the Applicant include street sweeping on a routine schedule in
compliance with Volume 2, Chapter 1,page 9 of the MSH.
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April 3, 2026: The Applicant has stated that because of the parked cars, street
sweeping would be considered a burden while providing minimal benefit. HW
defers discussion of this long-term maintenance program to the Planning Board.
HW imagines that there are typical times during a week when the parking lot of
this medical office building is not full of cars.
d. HW recommends that the Applicant address the Phosphorous removal calculations in
accordance with§250-23 C. (1) of the North Andover Stormwater Regulations.
April 3, 2026: The Applicant has provided the required calculations. There will be
no reduction of phosphorous from the existing site conditions.No further action
is requested.
a. . „„� ap]��)]..jicaiiiiiiiil seelk..s approval. f0iiii l.e ca.d u li. laba, W i.1111111. SUMPS Ibe
e.ii-1.. l ..afterb.
Not-.-ed..
. Street :,.in.:: ] . s 1 .en. ad.d.ed. to tf.ie ]�� r do e.n.a .w,,,,m plan..
d.. Note .
5. Standard 5 is related to projects with a Land Use of Higher Potential Pollutant Loads(LUHPPL).
a. The Applicant has indicated that the project is considered a L UHPPL, likely because of
the vehicle trips per day. The Applicant has also noted that it is meeting Standard 5 to the
maximum extent practicable by improving the TSS removal.No further action is requested
at this time.
April 3, 2026:No further action is requested.
R,..esp� orise: Noted.
6. Standard 6 is related to projects with stormwater discharging into a critical area, a Zone II, or an
Interim Wellhead Protection Area of a public water supply.
a. The proposed development is not discharging near or into a critical area, Zone II or an
I WPA area. Standard 6 is not applicable.
April 3, 2026:No further action is requested.
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7. Standard 7 is related to projects considered Redevelopment. A redevelopment project is required
to meet the following Stormwater Management Standards only to the maximum extent
practicable: Standard 2, Standard 3, and the pretreatment and structural best management
practice requirements of Standards 4, 5, and 6. Existing stormwater discharges shall comply with
Standard 1 only to the maximum extent practicable. A redevelopment project shall also comply
with all other requirements of the Stormwater Management Standards and improve existing
conditions
a. This project is considered a redevelopment. As listed above, the Applicant is required to
meet the standards to the maximum extent practicable and improve existing conditions.
HW recommends that the Applicant describe how it is improving existing conditions.
April 3, 2026: The Applicant is improving existing conditions by adding hoods to
the existing catch basins and submitting a Long-term Operation&Maintenance
Plan for the property. HW supports the installation of solar panels on the existing
parking lot. However, it would appear that something more could be done to
improve the stormwater management of the parking lot runoff that is directed
towards the adjacent resource area. Suggestions include regular sweeping of the
parking lot, confirming and/or installing catch basins throughout the parcel that
have four-foot sumps, and/or removing excessive impervious surfaces in the
southern corner of the lot.HW defers further discussion of any improvements to
the Planning Board
s „ n s ': SMeet,t-- , eel„ n.,. ][ ..w Ibeen. u u.' .. to 1 perat...n.an.d. Mai tt.ten.an.cep l[an.t provi'.Je
8. Standard 8 requires a plan to control construction related impacts including erosion,
sedimentation, or other pollutant sources.
a. The Applicant has provided erosion controls on Sheet C-1 and the associated details on
Sheet C-3. The catch basins will be installed with silt sacks, and an erosion control barrier
will be placed at the edge of the pavement closest to the resource areas. HW notes that the
area of land disturbance is relatively minimal, including 10 columns to hold the canopies,
and the installation of the electrical cables beneath the existing asphalt. No further action
is requested.
April 3, 2026:No further action is requested.
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b. HW notes that the limit of disturbance will be less than 1 acre therefore a Construction
General Permit (CGP) and a Stormwater Pollution Prevention Plan (SWPPP) is not
required by EPA.
April 3, 2026:No further action is requested.
Response: Standard 8 Response
a. Noted
b. Noted
9. Standard 9 requires a Long-Term Operation and Maintenance (O &M)Plan to be provided.
a. The Applicant has provided an Operation and Maintenance Plan as Appendix D in the
Stormwater Management Report. The document can easily be removed as a standalone
reference. The plan lists the Landowner and Team Leader. However, there are several
contacts that are noted as TBD and references to the Town of Walpole that should be
corrected. The Planning Board may choose to require receipt of a final signed O&M Plan
prior to land disturbance as a condition of approval.
April 3, 2026:Suggested condition of approval.
b. HW recommends that the Applicant include inspection of the outfalls and sweeping of
the parking lot in the O&M Plan.
April 3, 2026: The Applicant has included inspection of the outfalls in the O&M
Plan. It has removed the sweeping of the parking lot. It is HW's opinion that the
parking lot should be swept a minimum of once a year.
c. HW recommends that the Applicant provides a simple sketch that includes the stormwater
practices for the entire parcel, specifically all catch basins and outfalls. HW further
recommends that the sketch includes snow storage locations.
April 3, 2026: The Applicant has included a sketch, with its response to
comments, that indicates where the existing snow storage is located on the site.
HW recommends that a simple sketch that clearly calls out each catch basin and
outfall is attached to the O&M Plan for the benefit of the property owner.HW
further notes that the Table of Contents provided in the O&M Plan and the list of
items included in Appendix A should be reviewed and updated.
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III.. Noted..
b . Street- . .e ,,p� 1..gin ..r has been..ad.d.t.l.d. to the e i r:: ii�i. xiiii. plan. per"th.e peer
iiir Ili.. oiiiiniiii.ce a yelar i iiiri. :fte'r the silin.ow iIIIrne l : ]*A-]*A-t the
u. A si.iiiiri. ', . s � c]a. �1.t��illli. .��.�� to l I. lb � .Ill�IIII. , :t ].].s ari.d. Illillli. . .., iIlr III-e 11ave. b iiil`
10. Standard 10 requires an Illicit Discharge Compliance Statement be provided.
a. The Applicant has provided an unsigned Illicit Discharge Compliance statement. The
Planning Board may choose to require receipt of a signed version as a condition of
approval.
April 3, 2026:Suggested condition of approval.
Response:
Noted
Please contact me if you have any questions or need additional information at 978-703-6024 or
iralphsgnobis-group.com.
Sincerely,
64��_
Jon Ralphs
Project Manager
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CARPORTSTRUCTURES SOLAR CARPORT STYLE
SINGLE COLUMN SINGLE T
DESIGN CRITERIA
Wind Load: 90 MPH minimum
Ground Snow Load: 30 psf minimum
All Federal, State and Local codes reviewed.
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HSS ASTM A-500 Grade B
Coating Options: Primed or Hot Dip Galvanized
BEAMS
Wide Flange A 992 Grade 50 Steel.
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PURLINS
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Solar Racking
End Overhangs 1'
Roof Sheeting
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SOLAR CARPORT
CARPORTSTRUCTURES
BEAM OVER - DOUBLE
DESIGN CRITERIA
Wind Load: 90 MPH minimum
Ground Snow Load: 30 psf minimum
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HSS ASTM A-500 Grade B A-500
Coating Options: Primed or Hot Dip Galvanized
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Wide Flange A-992 Grade 50 Steel.
Coating Options: Primed or Hot Dip Galvanized
PURLINS �
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Wide Flange a-992 Grad 50 Steel.
CoastingOptions: Primed or Hot Dip Galvanized
RACKING
Solar modules mount directly to Purlins.
OPTIONS
Fixed Tilt slope up to 10'
Hot Dip Galvanizing
Site Specific Layout and Configuration
BEAM crvERHaruc 10 Fr MAX
Solar Racking
End Overhangs - up to 10 ft
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Roof Sheeting
30 DEG BEVE CUT
Soffit Under Sheeting _ a
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