HomeMy WebLinkAboutOWTS Design Report 01.06.2021Design Calculations
For
Tarin Residence
on-site Wastewater Treatment System
0405 County Road 104
Carbondale, Colorado
January 6, 2021
CIVCO Engineering Inc
Civil Engineering Consultants
Vernal, Utah
1256 W. 400 S. Office: 435-789-5448
P.O. Box 1758 Fax: 435-789-4485
Vernal, L T 84078 www.civcocngineering.cam
J
1
CIVCO Engineering, Inc.
PO Box 1758, Vernal, UT, 84078
Ph: (435)789-5448
Fx: (435)789-4485
TARIN
0405 County Road 104
Parachute, Colorado
Referenced Calculations
Description
OWTS SIZING Page 1
By: WK Date: 12/08/2020
Chk'd: wk Date: 01/06/2021
Section contains calculations sizing the components of the On-site Wastewater Treatment
System.
Design Standards
Garfield County Resolution 2018-36 GCR
Site Investigation
A backhoe excavator was used to dig two 9 -foot deep profile holes near the proposed location
of the Tarin on-site wastewater treatment system (OWTS) soil treatment area. Graphic logs
of both profile holes are shown in the construction drawing for the OWTS. No standing water,
nor evidence of previous groundwater level, was encountered in either profile hole.
Percolation test locations were also prepared and presoaked. Percolation test holes were 10"
to 12" in diameter and 12" to 13" deep below the presumed infiltrative surface at 2' below
ground level. Percolation tests were performed the following day. The percolation test data is
tabulated on Sheet 2 of this document.
The approximate locations of wells, water supply lines, property lines, and buildings were
noted and are shown on the OWTS construction drawing. A 100 -foot offset radius for the
water well, a 10 -foot offset line for the property boundary, and a 25 -foot offset line for the
water supply line are all noted on the construction drawing as well.
According to Google Earth data, the property slopes north -to -south at approximately 9% in
the vicinity of the proposed OWTS.
OWTS SIZING - tarin2.mcdx
CIVCO Engineering, Inc.
PO Box 1758, Vernal, UT, 84078
Ph: (435)789-5448
Fx: (435)789-4485
TARIN
0405 County Road 104
Parachute, Colorado
Number of Bedrooms Ned==3
Perk Test Results:
OWTS SIZING Page 2
By: WK Date: 12/08/2020
Chk'd: vvk Date: 01/06/2021
Minutes
Elapsed
Test Hole 1
Test Hole 2
Test Hole 3
Water
Level Drop
lin.)
Perk Rate
(Min./In.)
Water
Level Drop
(in.)
Perk Rate
jMin./In.)
Water
Level Drop
(in.)
Perk Rate
(Min./In.)
30.00
1.5625
19.20
1
30.00
1.5
20.00
60.00
1.1875
25.26
0.625
48.00
1.125
26.67
90.00
0.875
34.29
0.625
48.00
1.125
26.67
120.00
0.75
40.00
0.5
60.00
1
30.00
150.00
0.625
48.00
0.625
48.00
1.125
26.67
180.00
0.5
60.00
0.625
48.00
0.875
34.29
210.00
0.625
48.00
1.125
26.67
0.875
34.29
240.00
0.5
60.00
0.625
48.00
0.625
48.00
Hole Perk Rate: 60.00` 48.00; 48.00
Ave. Perk Rate: 52.00
SEPTIC TANK
Required Tank Volume V :=
if Ned<3
11(1000•gal)
else
II(�(_3).259
[GCR TABLE 9-1]
=I 000ga/
First Compartment Volume 16St comp°=
OWTS SIZING - tarin2.mcdx
if NNad<3 =500 ga/
II (500.9x/)
else
II500 • gal+ (A/0„/- 3) • 125.667
[GCR 43.9.B.4.a]
CIVCO Engineering, Inc.
PO Sox 1758, Vernal, UT, 84078
Ph: (435)789-5448
Fx: (435)789-4485
SOIL TREATMENT AREA
Design Flow Q:=
TARIN
0405 County Road 104
Parachute, Colorado
if lvd<22
300 �`?!
else if Nom= 3
450 gal
day
else if Nd> 3
450 gal (A/ —3) 75 gal
day day
Long-term Acceptance Rate (LTAR)
Perk Rate
OWTS SIZING Page 3
By: WK Date: 12/08/2020
Chk'd: wk Date: 01/06/2021
=450 gal [GCR Table 6-1]
day
gal
t:=ta,e=52 mm Type 3 soil.... LTAR:= 0.35 d
aY
in fi2
[GCR Table 10-1]
Unfactored Soil Treatment Area 5TA:= =1285.71 62
LIAR
Soil Treatment Area (Factored for Bedded Chambers)...
Application Method Size Adjustment Factor.... 5AFAM:= 1.2 (gravity)
Distrlb. Media Size Adjustment Factor SAP,M:=0.7 (chambers)
[CCR Table 10-2]
[CCR Table 10-3]
Cumulative Size Adjustment Factor.... SAF=if 5AFAM•.5AFQM>0.5 =0.84
II5AFAM• 5AFoM
else
114:15
[CCR 43.10.D.3]
Bedded Chambers Soil Treatment Area 5TA5c:= 5AF• 5TA= 1080 ft 2
Chamber Bottom Width 85:= 34 in
Required Bedded Chamber Length 5 B ®c =381.18 fit
OWTS SIZING - tarin2.mcdx
CIVCO Engineering, Inc.
PO Box 1758, Vernal, UT, 84078
Ph: (435)789-5448
Fx: (435)789-4485
TARIN
0405 County Road 104
Parachute, Colorado
OWTS SIZING Page 4
By: WK Date: 12/08/2020
Chk'd: wk Date: 01/06/2021
REQUIRED SOIL TREATMENT AREA MI FT.) = 1080.
NUMBER OF CHAMBERS PER ROW
NUMBER OF ROWS IN SOIL TREATMENT AREA
1
. 2
3
4
4
5
6
7
C EAMBR
, MAKE &MODEL
INFILTRATOR
QUICK 4 PLUS
EFFECTIVE CHAMBER WIDTH (INCH) = 34
EFFECTIVE CHAMBER LENGTH (INCH) = 48
MINIMUM TOTAL CHAMBER LENGTH (FEET) = 381
----
.
__
24
_
--
--
ADS
BIODiFFUSER
EFFECTIVE CHAMBER WIDTH (INCH) = 34
EFFECTIVE CHAMBER LENGTH (INCH) = 75
MINIMUM TOTAL CHAMBER LENGTH (FEET) = 381
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--
--
16
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Laterals may not exceed 100feet in length [GCR 43.10.E.2.c]
Bed width may not exceed 12 feet. [GCR43.10.F.2.a]
OWTS SIZING - tarin2.mcdx