HomeMy WebLinkAbout1995-Response Comments 40 Flagship WITHDRAWN E
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Dec. 10, 1996 Frank Iebba,PE, PLS
PO Box 620622
Newton Lower Palls
MA, 02162-0622
617-553-0299
Ms. Kathleen Colwell
Town Planner
120 Main St.
North Andover, Ma, 01845
RE: Lot F Flagship drive
Hear Ms. Colwell:
Enclosed is a set of plans following our meeting of Dec. 9, 1996 , The following are
responses to your engineers letter dated Dec. 6, 1996:
1-7. I believe these latest plan revisions satisfy these items,
8. Turning radii of 25 ft for the inside and 45 ft for the outside of the movement have
been used and C-50 vehicles can make the turn.
9. I'd like to point out that the wall height varies,also the plan has been endorsed.
10. SCS based calculations have been submitted.
11. All present soil testing was done by the previous consultant.
As discussed, if you will be requiring additional tests,we would
like to obtain conditional approval subject to doing the
test pits and percolation tests neat spring prior to construction.
If percolation rates are found slower than assumed then the number
of leach pits will increase accordingly. There is more than adequate
space at the site if more pits are needed. I would also like to point out that in in),
original drainage calculations I used a figure of 4 inches of total rainfall
in sizing the pits. In fact I could have used only the difference between Post and
Predevelopment runoff as allowed under your regulations. Assuming that we can
agree on the latest SCS calcs I gave you, the only storage required is for the
runoff increase resulting from the proposed development. That amounts to only 1,52
inches (3.28 post minus 1.76 pre).The original calcs are therefore conservative.
I do not agree with the 2.5 safety factor and 4 ft separation to groundwater
that Mr. Clnessia mentions in his letter, These figures are not part of any state,
federal, or local regulation in effect that I am aware of and are also not part of
standard engineering practices that have been used and tested. In the majority
cases in this area this would result in mounded storniNvater infiltration systems
which is poor practice.
12. I have enclosed a plan with drainage areas overlaid on it. From this and my
previous submittal it should be evident that the drainage system is oversized.
If the Engineer should require additional material I will provide it.
13 . The roof drain connections will be interior to the building and will be provided
with the final building plans,
14. The Flagship Drive information has been added.
15. See latest plan revision for changes.
16. See latest plan revision.
17. See latest plan revision.
I believe I have addressed your Engineer's conc6rns, If you should have further
questions or comments, please contact meat your convenience.
Very MAY yours,
Frank Iebba,PE, PLS