HomeMy WebLinkAboutEngineer's System Design Report 05.28.2009May 28, 2009
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AI L ENC I NEERI NC, LLG
P.O. Box 800'7
Avon, Golorodo 81620
Phone 910.291.1033
Garfield County
Building and Planning Department
108 8th Street, Suite 401,
Glenwood Springs, Co 81601
RE: Individual Sewage Disposal System (ISDS)
Mr, Whit Dean is proposing to construct a Gambrel -Loft Barn located at 1136 County Road
129, Glenwood Springs, CO 81601. The proposed building will be comprised of a loft,
kitchen, (1) full bath and (1/2) bath.
Vail Engineering (VE) designed an expansion to his existing ISDS to accommodate this
proposed building. VE is proposing to install a separate 1000 gallon, 1 piece, concrete tank
from Copeland Concrete and an expanded absorption bed next to the existing system.
VE calculated the required absorption bed size per the Colorado Department of Public
Health and Environment, Water Quality Control Division, State Board of Health, Guidelines
on Individual Sewage Disposal Systems, Pages 33 & 34. VE used the previous percolation
rate of 13 minutes (ISDS permit No. 1738) to calculate the additional required absorption
area. (See Attached)
MINIMUM ABSORPT/ON AREA
A = 4xJi
5
A = MINIMUM ABSORPTION AREA IN SF
O = DESIGN FLOW OF SEWAGE IN GALLONS PER DAY
= PERCOLA 770N RA TE IN MINUTES PER /NCH
O = AVERAGE 75 GAL LONS/PERSON/DA Y (M/N. 2 PEOPL. E PER BEDROOM M/N. 2 BEDROOMS)
O = 300 GALL ONS/DA Y
O = MAXIMUM FLOW SHALL BE CONSIDERED 150 PERCENT OF AVERAGE DAILY FLOW
O = 300 GALLONS/DAY x 150 PERCENT
0 = 450 GALLONS/DA Y
t = 13 MINUTES
MINIMUM ABSORPTION AREA REWIRED.- 325 SO. FT
VE is proposing an expansion of the existing absorption bed with dimensions of 12 feet by
28 feet. This expansion will provide 336 SF which exceeds the minimum requirement and
shall match the existing drain field system that is currently in place at a depth of
approximately 4 feet.
Sincerely,
Adam Vail, PE
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