HomeMy WebLinkAboutConsultant Review - 107 CAMPION ROAD 7/15/2014 (2) andover 'i East River Place
consultants Methuen, Massachusetts 01844
inc. Tel. (978) 687-3828
Fax (978) 686-5100
www.andoverconsultants,com
June 23, 2014
North Andover Planning Board
Town Offices
1600 Osgood Street
North Andover, MA 01845
RE: Watershed Special Permit
107 Campion Road
Ladies and Gentlemen:
We are in receipt of review comments made by your consultant, Ms. Lisa Eggleston, P.E., for the
project captioned above, contained in her letter to the North Andover Planning Board dated June 17,
2014. Five copies of the revised plan revision dated June 19, 2014 are attached. The plan was
revised in response to some of the review comments as noted below:
Comment 1. The entire project site is located within the Watershed Protection District (WPD). It
is my understanding that the lot was created prior to Oct. 24, 1994 and is therefore not subject to
the "Conservation Zone" requirements of the Watershed Protection District regulations, however
this should be confirmed In addition, the Non-Disturbance Zone should be shown on the plan as
extending 100 feet from the edge of all wetland resource areas within the watershed district and
the Non Discharge Zone should be shown to include all of the area within 325 feet of the edge of
all wetland resource areas within the watershed district. The proposed uses are allowed by Special
Permit within these zones, however the construction of a new permanent structure within the Non-
Disturbance Zone also requires a variance from the Zoning Board of Appeals. The Special Permit
Requirements also call for proof that there is no reasonable alternative outside of the Non-
Disturbance and/or Non-Discharge Zones for any proposed discharge, structure or activity to
occur.
Response: The lot was created in 1985 by a subdivision approved by the North Andover Planning
Board on March 26, 1985 and recorded at the Essex North registry of Deeds as Plan No. 9887.
The 100 foot Non-Disturbance Zone coincides with the 100 foot buffer zone and the notation revised
accordingly. The 325 Non-Discharge offset from the wetland extends beyond the property limits; the
entire lot is within this zone.
The applicant was granted a variance by the North Andover Zoning Board of Appeals on May 13,
2014 for the proposed dwelling in the non-disturb zone under Petition No. 2014-004.
Comment 2. The Project Description states that the rain garden areas are proposed to compensate
for the filling of the wetland, however no calculations have been submitted to demonstrate this.
The rain gardens should not only provide sufficient storage to compensate for the filling of the
wetland, but also for the increase in impervious surface associated with the development of the
site. Based on the evidence of soil erosion I observed on the slope downgradient of the site (just
upgradient of the cul-de-sac at the end of Bonny Lane), no increase in overland flow from this site
should be allowed.
Civil Engineers « Land Surveyors m Land Planners
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Response: The project is exempt from the MassDEP stormwater standards as it is for a single family
dwelling. Also, the existing wetland area is on a slope of approximately 6.5% and provides no
storage. The rain gardens are proposed to provide areas to intercept runoff from the proposed
impervious areas and allow for infiltration of this runoff in compliance with the requirement, in the
Watershed Protection District, to infiltrate to the extent possible, (4.136.4.g.). In addition, the interior
of the rain gardens will be planted with various plants tolerant of frequent or alternate inundation and
the outside slopes will be planted with other plants. The proposed plantings are intended to replace
those lost in the isolated wetland because of construction.
Comment 3. Several test pit locations are shown on the Site Plan however the logs were not
included in the materials I reviewed. While the NRCS soil map indicates that the site soils should
be suitable for the infiltration proposed, the presence of the isolated wetland suggests that there
may be more restrictive soils on the site as well.
Response: The isolated wetland area was used for a soil stockpiling and staging area during the
construction of the sub-division and is the reason for the more compacted nature and reduced
infiltrative capacity at this location.
Comment 4. Proposed rain garden "A"should be moved as far upslope as feasible to minimize the
potential for breakout of infiltrated flow on the downgradient slope.
Response: Rain garden A was placed to pick up tributary area from as much of the lot as possible
while providing a reasonable back yard behind the house. The rain garden slopes are 3 to 1 and the
interior, infiltrative surface of the rain garden is at least 25 feet from the nearest down slope property
line and in an area that much of the existing lot drains to now.
Comment S. The Board may want to require a drainage easement or covenant on the property to
ensure that future property owners do not regrade or otherwise alter the proposed stormwater
management structures.
Response: The rain gardens are on private property for the benefit of the impervious surfaces on the
private lot. The rain gardens will require regular maintenance and possible replacement of the soil
media from time to time by the owner. Easements are not needed.
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Comment 6. As with similar projects in the Watershed Protection District, the creation of new
lawn area be limited to that which is absolutely necessary, and any new landscape area be
constructed in such a manner as to minimize the maintenance that is required, e.g. the soil should
be well aerated, it should have a minimum of 6-inches of topsoil and, where possible, native
vegetation should be planted to minimize the need for fertilizer and watering. The use of fertilizers
and other landscape chemicals on the site should be limited to organic, slow-release and low-
phosphorus products. Also consistent with recently permitted projects within the District, both the
limits of approved clearing and the restriction on lawn care products should be permanently
recorded on the deed to the property.
Response: The Applicant will comply if conditioned in the permit.
Comment 7. I also recommend that the use of coal tar-based pavement sealants be prohibited on
the property, as they have been determined to contribute high levels of polycyclic aromatic
hydrocarbons (PAHs) to stormwater runoff. Likewise, the use of copper on the building exterior
should be prohibited within the Watershed Protection District to prevent the leaching of this toxic
heavy metal into the water supply.
Response: The Applicant will comply if conditioned in the permit.
Consultants
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Comment 8. It appears that the proposed project will entail the disturbance of more than one acre
of land, hence it is subject to EPA's NPDES Construction General Permit (CGP) and will require
filing for coverage under the CGP and the preparation and implementation of a Stormwater
Pollution Prevention Plan (SWPPP) prior to construction. The SWPPP should be prepared in
conjunction with the site contractor and should include a construction sequence aimed at
minimizing the duration of exposure of unstabilized soils on the project site. The Planning Board
and✓or Conservation Commission may want to request documentation of coverage under the CGP
and a copy of the SWPPP and✓or monitoring reports.
Response: The entire lot contains one acre. Portions of the lot will remain undisturbed such that less
than an acre of the lot will be disturbed. Conservatively assuming that the entire lot uphill of the hay
bales is disturbed, approximately 40,900± sf or 0.94-E acres will be disturbed. As such, an NPDES
CGP is not required for this project.
Should you have any comments or require any additional information concerning the revisions above,
or have any additional questions, feel free to contact us.
Sincerely,
ANDOVER CONSULTANTS,INC.
James S. Fairweather II, P.E.
Project Engineer
Enclosures
cc
Eggleston Environmental
Dimitrios Saragas
Eggleston vir n n a
July 15, 2014
North Andover Planning Board
1600 Osgood Street
North.Andover,MA 01845
Attn: Curt Bellevance, Director of Community Development
RE: Watershed Special Permit
107 Campion Road
Dear Mr. Bellevance and Board Members:
In follow-up to my June 17, 2014 comments on the above-referenced project, I have
received the June 23, 2014 response letter and the July 9, 2014 revised plan and
calculations submitted by James Fairweather,P.E. of Andover Consultants Inc.
Based on the recent soil tests and runoff calculations, Mr. Fairweather has satisfactorily
demonstrated that the three proposed rain gardens would adequately mitigate projected
increases in the volume or rate of runoff from the site resulting from the proposed
development. Per the analysis, roof runoff from the proposed building should be directed
onto pervious surfaces or infiltrated via a drip trench or dry wells; it should not be piped
directly to the rain garden.
As outlined in my previous comments,the Board should consider requiring a covenant on
the property to ensure that future property owners maintain the rain gardens and do not
regrade or otherwise alter their functionality as stormwater management structures. While
Mr. Fairweather's response letter suggests that the rain gardens are solely for the benefit
of the subject property, I would argue that they also perform an important function in
preventing erosion on downgradient properties and protecting the water quality of Lake
Cochichewick. I also recommend that the conditions outlined in my previous comments
#6 and #7 be incorporated in any approvals issued for the project. Since the project will
not be subject to the EPA Construction General Permit, the Conservation Commission
may want to address erosion & sediment control requirements in its Order of Conditions
as well.
Once again,I appreciate the opportunity to assist the North Andover Planning Board with
the review of this project, and hope that this information is suitable for your needs. Please
feel free to contact me if you or the applicants have any questions.
Sincerely,
EGGLESTON ENVIRONMENTAL
Lisa D. Eggleston,P.E.
C: Jennifer Hughes, Conservation Coordinator
32 Old Framingham Rd Unit 29 Sudbury MA 01776 tel 508.259.1137