HomeMy WebLinkAboutPermit Correspondence 2005-7-31
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Jul 3t/200\ 9:27PM
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Date: 07/31/05
Invoice No. 259
Remit Payment 10:
Ronald J. Derrick, P.E.
420 NW Maxine Avenue
Corvallis, Oregon 97330
Ph. 541-913-0220
Fax. 541-753-0938
Mr. Stu Meyers
1620 Kellogg Road
Springfield, Oregon
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Uuanlltv Unit l,;OSl . Uescnollon ot ~envces
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1 $100,00 Infiltration Basin Design
1620 Kellogg
$100,00
Totllllnvoice.,..,....... $100,00
Thank You for Your Businesslll
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Jul 31 2005 9:27PM
.LASERJET FAX
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Rone/d J. DerrIck, P.e.
420 NW Maxine Avenue
Corvallis, Oregon 97330
Ph. 541.913.0220
Fax 541-758-8563
July 31,2005
Mr. Stu Meyers
1620 Kellogg Road
Springfield, Oregon
via Facsimile
RE: INFILTRATION BASIN DESIGN
1620 KELLOGG ROAD
SPRINGFIELD. OREGON
Based on my June 17, 2005 on-site infiltration testing and the data analysis presented in the
accompanying June 20, 2005 report. the following infiltration data and system design for
disposal of roof drainage off the existing residence on the property is presented herein.
The measured on-site vertical hydraulic conductivity at 1620 Kellogg Road is 0,3 ftlhr which
calculates to a rate of infiltration of 25 gallonsJhourisquare foot with a 2 foot hydraulic head.
The roof area of the existing residence is 1,078 square feet and the 5 year, 24 hour storm event
will produce 3,6 inches of rainfall. The calculated amount of drainage water produced is 323
cubic feet = 2,419 gallons'in 24 hours. The infillration area required to dispose of this volume of
water is 4 square feet, applying a safety factor of 2, the required infiltration area is 8 square feet.
A 3 foot squafe infiltration basin is recommended and the basin shall be a minimum of 5 feet
deep with a foot of topsoil cover and shall be located at least 5 feet laterally from structural
foundations, The storage volume of a 3'x3'x4' deep basin filled with rounded drain rock is
estimated to be 94 gallons of water. The infiltration pit shall be constructed as shown on the
attached detail.
Limitations
This rep'ort was prepared solely for the Owner and engineerfdesigner for the design of the
. project. The .opinions and recommendations contained within the report are not intended to be
nor should they be construed to represent a warranty of subsurface conditions, but are intended
to assist in the planning and design processes, This report pertains to the material
testedlinspected only. Information contained herein is not to be reproduced, except in full,
without prior authorization form this office, This report does not express any opinions nor does
it make any conclusions regarding any environm~!IH11 concerns of in-ground storm water
disposal. 'r~,'J>- '. '
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Ronald J. Derrick, E
Sincerely.
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Jul 31 2005 9:27PM
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Notes:
Minimum depth of Il1fIltratlon Pills 5 feel
Fill pit with open graded round drain rock (314" or larger)
Wrap drain rock In flllerfabrlc (Mlratl140N or equivalent)
Inllno clllanout or
debris trap ,
12 Inches of Topsoil
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5 Feet
............
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.w......,... .........'
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. . . . . . .. . . .' I.>'
............. ...w w"
Tight line drain pipe
from surface Inlets
st 2% min, slope
3 Feet
Infiltration Pit Construction Detail
Not to Scale
FIGURE 1
INFILTRATION BASIN DETAIL
1620 KELLOGG ROAD, SPRINGFIELD OREGON
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