HomeMy WebLinkAbout2012-03-20 Planning Board Supplemental Materials (124)102 Peters Street-February 27, 2012 revision
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February 28, 2012
North Andover Planning Board
Town Offices
1600 Osgood Street
North Andover, MA 01845
RE: Site Plan Special Permit
102 Peters Street
North Andover, MA
Members of the Board:
We are in receipt of a second peer review made by your consultant, Hancock Associates., for the
project captioned above. The comments were made in a letter to the North Andover Planning Board
dated February 22, 2012. Many of their initial comments made in their first review have been
addressed. Comments 4, 5, 9, 10, 11, 16, 18, 20 and 21of the second review require additional
response. Our responses are summarized below:
Comment 4: The Location map still does not conform to the required scale of 1”=1500’. The
intent of the locus scale is to see the project site within the context of the surrounding area. The
Board should decide if given the location, they need to see more of the surrounding area within
the locus map. The Applicant should request a waiver from this submission requirement.
Response: We believe that the intent of the Locus has been satisfied. However; on behalf of the
Applicant, Dundee Properties, we respectfully request that the Board waive the scale requirement of
1”=1500’ and accept the submitted locus scale of 1”=800’.
Comment 5: While the plan does not conform to the requirements for the extent of topography
shown, Hancock believes that suitable information is provided to complete our review, the
Applicant should request a waiver from this submission requirement.
Response: As previously noted, we believe that the offsite topography for this small project as
appropriately accounted for. However, on behalf of the Applicant, we respectfully request that the
Board waive the requirement of depicting offsite topography for 50 feet beyo nd the project
boundary.
Comment 9: The plan entitled Conceptual Landscape Plan by Huntress Associates, Inc. dated
August 4, 2011, revised February 1, 2012 depicts a region of existing trees to remain at the
southern property line. The plan does not speak to the required identification of existing trees 12
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inches in diameter or larger. The plan also does not include a tabular list containing the amount
of required plantings.
Response: The landscaping plan is being revised to coordinate with the comments from the DPW
to remove trees from the sewer easement and to account for the proposed stone trench in the
northwest corner of the lot. There are no existing trees of 12” diameter or larger that will remain at
the southern end of the lot. Per Section 8.4 of the North Andover Zoning Bylaw, “Screening and
Landscaping Requirements for Off-Street Commercial and Industrial Districts”, the revised plan
conforms to this section as there is no quantity of required plant ings for a project this small. The
revised Landscaping Plan will be forwarded when completed.
Comment 10: Hancock is in agreement that the size of the project may not require a dumpster.
However, refuse generated from the proposed business or medical office will require some sort of
storage and the plan does not address its type, location or required screening.
Response: The trash will be stored inside the janitor’s closet internal to the building until trash day
at which time it will be brought to the curb for pickup.
Comment 11: The plans still do not depict the direction and degree of illumination proposed.
Response: Site lighting will consist of wall packs mounted on the structure as previously stated. A
copy of the proposed fixture was also previously submitted. Additional information concerning the
lighting is included in the attached email prepared by the project architect, Maclaren Associates,
LLC, dated February 28, 2012.
Comment 16: The “sketch” that was provide is not to scale and does not depict the full extension
of the sight line on Peters Street. The DJK Memorandum was not updated to specifically address
any action to enhance sight distance. The landscape plan identifies two (2) red maple trees
located on both sides of the entrance. From the “sketch” provided, the sight lines appear to
conflict with both of these plantings. Hancock recommends that the full sight distance lines be
shown on all plans and clearly identify any measures that will be taken to enhance sight distance
on the subject property and abutting parcels.
Response: The sight line issues discussed in the DJK Memorandum were intended as project
recommendations to coordinate with proposed site landscaping. It is not necessary to depict the full
extent of the sight lines as they are very conservative for this stop controlled parking lot and
because the intent of coordination has been met. See the attached Landscaping Plan which depicts
the sight lines referenced. A note has also been added to the site plan noting to remove vegetation
within the right-of-way that may interfere with exiting vehicles looking west.
Comment 18: It remains unclear from the details provided how the building structure below
grade would not encroach into the sewer easement. Standard construction details have footings
extending beyond the face of the structure.
Response: The building wall is located about 10 inches from the sewer easement. See the attached
email from Maclaren Associates, LLC addressing the extension of the footing beyond the east wall.
Comment 20: Hancock is not in receipt of comments from the Applicant’s Landscape Architect
attesting that the plantings in the sewer easement will not adversely impact the sewer line.
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Response: At a meeting with Mr. Gene Willis, PE, Director of Engineering of the North Andover
Public Works Department, Mr. Willis requested that all trees be removed fro m the easement. The
trees have been removed from the easement. When asked if shrubs were o.k., Mr. Willis stated that
shrubs were o.k.
Comment 21: The plans do not clearly identify the perimeter drain, there are no elevations or
slopes identified and the size and type of material have not been specified.
Response: The perimeter roof drain information has been added to the plans. The roof drains are 6-
inch diameter, schedule 40 PVC pipes with a slope of 0.5% (0.005).
In addition to the Hancock letter, we are also in receipt of a second comment letter from Gene
Willis, Director of Engineering for the North Andover DPW to the Board and dated February 24,
2012. Mr. Willis had two comments and our responses to his second set of comments are noted
below:
Comment 1: The overflow structure proposed in the NW corner of the lot was not relocated to the
south and away from Peters Street right-of way but replaced by a stone swale. Over time, the
voids in the stone will fill with sediment resulting in zero storage volume. The originally
proposed drywell should be included in the final design.
Response: The drywell has been restored to the project as requested and is depicted on the revised
Site Plans, revision dated February 27, 2012.
Comment 2: The hydraulic modeling of the site, as well as the subsequent report, has not been
reviewed by DPW.
Response: Noted. The project’s stormwater components are being review by Eggleston
Environmental. A copy of the revised stormwater calculations and report will be submitted to DPW
for their records.
Finally, we have also received a second set of comments from Lisa Eggleston, PE of Eggleston
Environmental detailed in a letter to the Planning Board and Conservation Commission dated
February 24, 2012. We offer the following in response:
Comment 1: The design revisions call for moving the overflow drywell approximately 35 feet
back on the site (away from Peters Street) and incorporating an overflow swale with a stone
trench to further enhance infiltration and direct the overflow onto the shoulder of Peters Street.
This should mitigate any increases in runoff volume generated by the development and prevent
the direct discharge of flow onto Peters Street. It will also provide some degree of treatment for
snowmelt off of the west side of the proposed parking area.
Response: The drywell has been relocated away from Peters Street as was suggested in Ms.
Eggleston’s February 7, 2012 email to Judy Tymon and Jennifer Hughes, and per comment #1 in
Mr. Willis’s comment letter to the Board dated February 7, 2012. The stone trench and sod berm
were added to increase the surface storage on the lot and provide for additional avenues of
infiltration to provide the additional treatment and mitigation noted above.
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Comment 2: The Stormwater Report should be revised to reflect the modifications to the outlet
design. Calculated storage in the outlet drywell and overflow trench should be limited to that
which is above the ESHGW level in that location, so that the modeled discharges are
representative of "worst case" conditions. Based on the existing grades on the site and the
ESHGW elevation in the two test pits, it appears that this would be somewhere around elevation
188.0.
Response: As has been stated before, the drywell and stone trench are additional features provided
to enhance potential infiltration over and above that provided by the perforated pipe detention
system. The infiltrative capacity of the perforated pipe detention bedding, drywell and stone trench
are not needed to mitigate peak flows. Note that the attached calculations do not model exfiltration
for the parking lot drainage system components. The post-developed peak rate is mitigated by
storage in the pipes and the rates depicted in the pre vs. post developed runoff rate comparison do
represent worst case scenarios.
The available storage in the perforated pipe bedding is approximately 150 cf. The storage within
the drywell, above elevation 186.5 (bottom of adjacent trench) is 22 cf, while the stone trench
provides void space of 120 cf. The surface storage detained behind the proposed sod berm is
approximately 24 cf. The total volume provided by the drywell, trench and surface storage is equal
to 166 cf which is more than the 150 cf required for WQV of the tributary parking lot.
Comment 3: During periods of seasonal high groundwater there will be no dead storage in the
detention system beneath the parking lot, hence no water quality treatment via infiltration. It is
my understanding that the overflow trench has been designed to capture and infiltrate the water
quality volume, however calculations are needed to demonstrate this.
Response: See the above. The potential available water quality volume in the stone trench and
drywell area exceeds that required. Note that the peak rates are mitigated in compliance with the
state and local stormwater regulations and that there is no direct discharge to a wetland area.
Comment 4: The plans should show the perimeter drain proposed for the collection and
conveyance of roof runoff.
Response: The roof drain information has been added to the revised plan as suggested.
Comment 5: A design detail of the overflow swale/trench is needed. The side slopes of the swale
should be vegetated or otherwise stabilized. I have not seen the landscaping plan, but presume
that it may also need to be revised to show the swale.
Response: A detail has been added to sheet 3 of 3, as suggested. The stone trench is rectangular at
24 feet long by 5 feet wide and 30 inches deep. The swale is 5 feet wide with 2 to 1 side slopes.
The Landscaping Plan is being revised to coordinate with the swale and stone trench.
Comment 6: I suggest rewording item #3 in the O&M Plan to say that the catchbasins should
be cleaned when the sediment level is within two feet of the outlet pipe; this is easier to measure
than the depth of sediment accumulated. The O&M Plan should also include maintenance of
the overflow swale/trench.
Response: The O&M plan has been revised to reflect cleaning required per the depth from invert,
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as suggested. Also, maintenance of the stone trench has been added to the checklist and the
inspection schedule.
We believe that, with the latest revisions, all the comments made by your consultants and the DPW
have been appropriately incorporated into the design and respectfully request that the project be
issued the necessary approvals and permits for construction. Should you have any comments or
require any additional information concerning the above, feel free to contact us.
Sincerely,
ANDOVER CONSULTANTS, INC.
James S. Fairweather II, P.E.
Project Engineer
Enclosures
cc
Conservation Commission
Eggleston Environmental
Hancock Associates
MADEP-NERO
Dundee Properties