HomeMy WebLinkAboutCorrespondence - 814 OSGOOD STREET 3/17/2000 JM Associates
Civil Engineering Consultants
166 North Main Street Andover,MA 01810
978-475.8577 FAX 978-475-8451
March 17, 2000
Town of North Andover
Planning Board
27 Charles St.
North Andover, Ma. 01845
Re: Special Permit Application
#814 Osgood Street
Dear Members of the Planning Board:
I am writing this letter in support of the above application in regard to quality and
quantity of surface water runoff entering into Lake Cochichewick.
The proposed house addition is located on the westerly side of Osgood Street between
Chadwick Street and Colgate Drive and about 1850 feet(straight horizontal
measurement) from the Lake (refer to Plan of Land prepared by JM Associates dated
March 17, 2000).
In regard to water quantity, the impervious area of the roof of this proposed house
addition and screen porch is 492 square feet. The roof of the existing screen porch
which will be removed to make room for the new addition is 184 square feet. Thus the
net increase in impervious roof area=308 square feet. Given the travel time to the Laker
this increased area does not seem to be a large enough to produce a significant
degradation.
In regard to water quality,the fact that this runoff will be generated by rooftop is
significant. Rooftop runoff is generally regarded as "uncontaminated" by the
Massachusetts Department of Environmental Protection(DEP). Rooftop runoff is the
only impervious runoff that may be recharged back to the ground without pretreatment.
The flow path of this runoff will be easterly under Osgood Street via catch basins and
then northerly approximately 2000 feet to the Lake. Along this path the runoff will travel
through a significant length of wetland. One of the benefits of wetland is the ability to
remove pollutants. In fact wetlands are one of the "Best Management Practices" (BMP)
recommended by DEP for treatment of stormwater runoff. Catch basins are also
considered a BMP.
Page—2-
Thus, the uncontaminated rooftop runoff will be treated by 2 BMPs—the catch basins
and the wetlands -prior to entering the Lake.
Given the small scope of this house addition,the fact that rooftop runoff is considered
uncontaminated, and the BMPs already in place it is my opinion that that there will not
be any significant degradation to quality or quantity of water entering Lake Cochicewick
due to this proposed work.
Thank you for your attention to this matter. Should you have any questions or require
additional information please contact me at your convenience.
Very Truly Yours,
.'pw Of
JOHN F.
John F. McQuilkin P.E. M�CIVIL
No. 31282
Cc: Blair Roberts �`�S�ONAL
Caren Jacobson