Jager response letter to Staff.01.31.95 Stephen L. Jager Architect
7 0 C h r i s t a n h e r Drive • Enfield. CT 0 6 0 6 2 F o n j F a x 2.03.763. 825
January 31, 1995
REA �f�
❑USE VARIANCE NO.
James Martin, Planner 0SIGN
Town of Queensbury / I,
531 Bay Road
Queensbury, NY 12804-9725
RE: Jeffrey & Debra Godnick - AV 71-1994
Dear Jim,
Per Planning Board Resolutions of January 17, 1995, 1 would like to respond to those
comments:
1. The Owner intends to install a new on site sewage disposal system per
Town of Queensbury Building and Codes Department and Board of
Health regulations "Chapter 136, Sewers and Sewage Disposal'.
2. Size of residence and paved areas have been reduced on revised
site plan to reduce impervious area and increase permeable area. I
have spoke to RIST-FROST to discuss their concerns and have
addressed those in a letter dated January 31, 1995.
3. No items under this number.
4. No comment.
If you have any questions, please call me.
Sincerely,
Stephen L. Jager
Architect
cc: John Lapper, Esq.
Jeffrey & Debra Godnick, Owners
Stephen L. Jager Architect
0 Chrisfocher Drive • E n 1 1 e I d. CT 0ti_ 082 • For 1Faz 203._'G3. 1825
December 28, 1994
Revised January 31, 1995
Project: Storm water Runoff Calculations & Drywell Design For
Jeffrey and Debra Godnick
RR1 Box 1759
Lake George, NY 12843
- Design drywell to accommodate post-development runoff and driveway runoff.
- Post-development runoff = Proposed impervious - Existing impervious sq. ft.
= 5,404 sq ft - 4,821 sq ft
= 583 sq ft + driveway 2,070 sf
= 2, 653 sq ft
- Existing surfaces, C = 0.35 for runoff coefficient
- Proposed surfaces, C = 1.0 for runoff coefficient
- Q =CiA, where C = runoff coefficient
where i = rainfall intensity at 50 year storm
where A = difference between post-development and existing
development square footage
- For very small areas, Tc s 5 min.
RUNOFF CALCULATION
VoIT,c.f. (cubic feet) _ (1.0 - 0.35)(i, in/hr)(2653 sf)(1 ft./12 in)(T, min)(1 hr/60 min)
i, see chart - 50 year storm.
T (time) i in/hr VoIT cf
5 min 7.5 89
10 min 6.0 143
20 min 4.3 205
30 min 3.3 236
40 min 2.7 258 c;FR-�Af7cyT
60 min 1.9 272
120 min 1.1 315
240 min 0.7 401 J' .
�l
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OF NE
December 28, 1994
Revised January 31, 1995
Project: Storm water Runoff Calculations For
Jeffrey and Debra Godnick
RR1 Box 1759
Lake George, NY 12843
Try a 8 ft dia precast concrete drywell 4 ft. deep
CAST IRON
GRATE& FRAME
SLOPE PRECAST COVER GEOTEXTILE
r FABRIC ALL
AROUND STONE
i ENVELOPE
i
r3 4-0" 6
t
d CRUSHED STONE
°v ENVELOPE, CLEAN,
2 1.4, L (WASHED), MIN 2"-3"
SIZE, POROSITY
1 b APPROX. 0.35
MAX HIGH GROUND WATER
BELOW BOTTOM OF STONE
10'-0" r, =5'-0"
15,,0„ 1-2 =T-6„
SECTION THRU DRYWELL
NOT TO SCALE
A. Storage Volume = void volume of stone + void volume of drywell
Void Volume of Stone =(n(h) (r,2 + r22 + (ri x r2)] -n r32 h2)0.35
3
=15 (52 + 7.52 + (5x7.5)] - n424�0.35
3
= 147 cf
Volume of Drywell = n r32 h2
Volume of Drywell = n (42)(4)
Storage Volume = 147 cf + 201 cf
= 348 cf ` , /
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`; cFSr�, ozzE20.1 y0
FOF N
December 28, 1994
Revised January 31, 1995
B. Storage Area of Stone Envelope
Surface, sq. ft. _ [n (r, + r2) x ide slope length TT r12
_ [n (5 + 7.5) x 2.52+ 511n52
= 298 sf
C. Infiltration Rate ( perc rate of 2.5 minAnch, sandy loam) estimate
For 6" x 12" x 12" = 1/12 cf = 0.01111 cf/sf/min
Std. perc hole 2.5(3sf)
Infiltration rate = 298 sf x .01111 cf/sf/min
=3.31 cf/min
i
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FOF t`Ir�TJ
ALBANY, NEW YORK
1903-1950
20.0
150
NO
REQi IENCY A LYS S B ME FHOD
10.0 EX73EM VA UES 4FrE3 G MBEL
80
6.0
40
O 2.0
S
r{HX
z
2: 0.6
}
r 06
u�
r
2 0.4
J
J
Q
LL
Z
3
02
01
0.08
006
004
0.02
5 10 15 20 30 40 50 60 2 3 4 5 6 8 10 12 18 24
MINUTES HOURS
DURATION
4 of 5
0'2az1'`
FOF
December 28, 1994
Revised January 31, 1995
PLOT- INFLOW /OUTFLOW HYDROGRAPHS FOR
2653 SF INCREASE IN IMPERMEABLE AREA &
8 FT DIA X 4 FT DEEP DRYWELL (AS DETAILED)
600540
�f
480 j ....
420
DRYWELL CAPACITY PROVIDED
AT INFILTRATION RATE=3.31 CF/MIN - --
360
348
300 - DRYWELL REQUIRED
INFLOW CAPACITY
} 240 (INCREASED RUNOFF)
180 i..
120
0
0 510 20 30 40 60 2HRS 4 HRS
TIME
CONCLUSION-A SINGLE 8 Fr DIA X 4 Fr DEEP DRYWELL WITH STONE ENVELOPE
WILL HAVE ADEQUATE CAPACITY TO ACCEPT AND INFILTRATE
THE INCREASED RUNOFF FROM 2653 SF OF ADDITIONAL IMPERMEABLE
AREA DUE TO 50 YEAR STORM AND SOIL CAPABILITIES AS NOTED.
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