HomeMy WebLinkAboutOWTS Design Packet 06.21.2020PERCOLATION TEST AND
ON-SITE WASTEWATER TREATMENT SYSTEM DESIGN
TRACT 37 ANTLERS
ORCHARD DEVELOPMENT
SILT, COLORADO
Prepared For:
J Caliber Construction
Prepared By:
CAPSTONE '` '
ENTERPRISES WEST,LLC
'N
GEOTECHNICAL AND MINING ENGINEERING
TESTING AND INSPECTION SERVICES
618 PARTEE DRIVE
GRAND JUNCTION, CO 81504
PHONE (970) 250-3331
June 21, 2020
Job No. 4546
CAPSTONE
ENTERPRISES WEST, LLC
GEOTECHNICAL AND MINING ENGINEERING
TESTING AND INSPECTION SERVICES
618 PARTEE DRIVE
GRAND JUNCTION, CO 81504
PHONE (970) 250-3331
June 21, 2020
JOB # 4546
Attn: J Caliber Construction
Rifle, CO
Subject: Percolation Test and On -Site Wastewater Treatment System Design for
TRACT 37 ANTLERS
ORCHARD DEVELOPMENT
SILT, COLORADO
At your request Capstone Enterprises West, LLC directed and observed the excavation
of the two test pits to evaluate onsite soils for design of an additional On -Site
Wastewater Treatment System (OWTS). The suitability of soils was evaluated by soil
classification as prescribed by the Garfield County Health Department, and confirm by
performing a modified percolation test,
The results of investigation and the percolation test with the OWTS design are presented
in this report. If you have any questions, or if we may be of further assistance, please do
not hesitate to contact us.
Respectfully Submitted:
CAPSTONE ENTERPRISES WEST, LLC
Martin W. Chenoweth, PE
Registered Professional Engineer
MWC
CAPSTONE ENTERPRISES WEST, LLC 2
JOB NUMBER 4546
PERCOLATION TEST
Per your request, Capstone Enterprises West, LLC performed a percolation test for your
6 bedroom residence. The test was generally performed as prescribed by the Garfield
County Department of Public Works' regulations updated on July 2"d, 2018.
The property is located in the southwest quarter of Section 36 Township 5S Range 92W.
The following images show the site location as well as the location of the profile holes.
Rifle
0
Site Location
Silt
CAPSTONE ENTERPRISES WEST, LLC 3
JOB NUMBER 4546
SITE DESCRIPTION
The property is a 10 acre parcel that was undisturbed grazing land before the
development of the subdivision. The central topographic feature of this lot is a mild ridge
that runs diagonally across the property from the southwest corner to the northeast
corner. The ground slopes off to the northwest, the south west and the southeast at
approximately 5 to 10%.
Three test pits were excavated to determine the soil types at the proposed OWTS
location at the base of the hill. The profile holes were excavated to depths of 5.5 to 9.0
feet. No free water was encountered to that depth, nor was there evidence of a seasonal
high water table. The geologic logs of the profile holes are presented on the following
page.
CAPSTONE ENTERPRISES WEST, LLC 4
JOB NUMBER 4546
10
TP -4
Silty Clay Alluvium
Firm SIRy Clay
TP -5
Silty Clay Alluvium
Dellis Flora
Firm Silt
Firm Brown Clay
TP -6
Slaty Clay Alluvium
Firm SIR
The soils at the site were consistent between the TP -4 and TP -6 excavations. The soils
that will utilized for the absorption bed are a Type 3 fine grain clayey silt (GR) with
massive structure.
To confirm this classification an abbreviated percolation test was performed. Two perc
holes were dug to evaluate the percolation rates. All holes were moisture conditioned as
prescribed by Garfield County Health Department. And the percolation test was
performed 24 hours after the initial conditioning. The results for the percolation test are
presented on the following page.
CAPSTONE ENTERPRISES WEST, LLC 5
JOB NUMBER 4546
HOLE ID &
DEPTH
ELAPSED
TIME
min.
WATER
LEVEL
in.
WATER
DROP
in.
PERCOLATION
RATE
minJin.
PH -1 -TP-4
0.0
0.00
0.00
48 - 64"
30.0
0.50
0.50
60.0
1.38
1.38
90.0
1.75
1.75
120.0
2.38
2.38
48.00
PH -2 TP -4
0.0
0.00
0.00
24 - 40"
30.0
0.75
0.75
60.0
1.13
1.13
90.0
1.63
1.63
120.0
2.13
2.13
60.00
AVERAGE 54.0
20.00
18.00
16.00
14.00
w
• 12.00
Ly
470
10.00
O
8.00
6.00
4.00
2.00
Water Drop Vs. Elapsed Time
-.410.-P1.1111.
4
--4.- PH 2 TP -4
Limns
0.00 - l--
0.0 20.0 40.0 60.0 80.0
Elapsed Time (minutes)
CAPSTONE ENTERPRISES WEST, LLC 6
JOB NUMBER 4546
The average of the for the last 30 minutes of the two-hour test was 54 minutes per inch.
Capstone believes that the un -official percolation test confirms the classification as a
type 3 soil. Based Garfield County Guidelines, the system has been designed based on
a Long Term Acceptance Rate (LTAR) 0.35.
Table 10-1 Soil Treatment Area Long -tens Acceptance Rates by Soil Texture, Soil Structure,
Percolation Rate and Treatment Level
Sell Type, Texture, Structure and Percolation Rate Range
Soil
Type USDA Soil Texture
R
USDA Soli
Structs re•
Type
t1sOA Snu
Structure.
Grade
Parc Mane
n Rale Treatment
(MPI] Laval 1'
.35% Rock (.2mm): See Table 104A
1 , Sand, Loamy Sand
2
Sandy Loam, Loam, Slit
Loam
Single
Grain
0
(Structureless)
5-15
Long•tenn Acceptance Rata (LTAR);
Oallone per day par square foot
Treatment Treatment
Level 2' Level 2N'
Treatment
Level 31
Treatment
Level 38"
>35% Rock (>2mm1: See Table 104A
0.80
1.40
1.40
1.55
1.55
PR
(Prismatic)
BK
(Blocky)
GR
(Granular)
2 (Moderate)
3 (Strong)
16-25
Sandy Loam, Loam, 55
PR, $K. 1 (Weak)
8
26-40
0.60
0.50
3
Sandy Clay Loam, Clay
Loam, Sdty Gay Loan
Massive tlltrudurelese)
PR, BK. 2, 3 41.60 035
GR
Sandy day Loam, Clay
3A
Loam. Silty Clay Loam
PR, BK, j 1
GR I 0
-Maaewe (Strkraurelesa)
61-76
0.30
1.0 1.0 1.1 1.1
0.80 0.60 0.90 0.90
0.55 0.55 0.65 0,65
0.46
0,45
0.55
0.55
4
Sandy day, Clay. Silty
Clay
Sandy day, Clay, Silty
Clay
Sob Types 2-4A
PR. BIL 2 3 76-90 0.20
GR
PR, BK, 1
GR 0 91-120 0.15
Massive 1 (Struclurnles.)
Platy ! 1, 2, 3 J 121. 1 0.10
0.30
0.20
0.30
0,20
0.30
0.20
0.30
0.20
0.15 0.1S
0.15
0.15
NOTE: Shaded areas require system design by a professional engineer.
1 Treatment levels are defined in Table 6.3
Higher long -tens acceptance rates for Treatment Level 3N may be allowed for OWTS required lo have a discharge
permit, If the capability of the design to achieve a higher long-term acceptance rate can be substantiated
CAPSTONE ENTERPRISES WEST, LLC 7
JOB NUMBER 4546
WASTE WATER TREATMENT SYSTEM DESIGN
The proposed residence for this site is planned to be a three (3) bedroom dwelling.
Using the guidelines in the Garfield County On -Site Wastewater Treatment System
Regulations, Effective Date: July 2, 2018 (OWTSR) the following sewage flow
calculations were prepared:
3 Bedroom Residence
Table 6-1 Q =450 gal. /day
Once again using the OWTSR the absorption area was calculated.
Where: A = Absorption Area in square feet
Q = Design Flow of sewage in gallons/day
LTAR = Long Term Acceptance Rate (From Table 10-1, OWTSR)
AREA
Q 450
LTAR 0.35
Base Area
Size Adjustment Factors
Gravity Bed
Chambers
1,286 sq. ft.
1.2
0.7
Total Absorption Bed Area 1,080 sq. ft.
1,286sgft
To obtain 1,080 square feet of absorption area a 12 foot wide bed 93 feet long (90
Chambers plus end caps) are required. A two compartment 1,000 -gallon septic tank is
required for this system. Capstone recommends that a concrete tank approved by
Garfield County be used for this system. Detailed plans are attached. The following table
shows the distance pertinent to this system.
CAPSTONE ENTERPRISES WEST, LLC 8
JOB NUMBER 4546
43.7Minimum Distances Between Components of an On-site Wastewater Treatment System and Physical Features
Table 7-1 Minimum Horizontal Distances in Feet Between Components of an On -Site Wastewater Treatment System Installed After
November 15, 1973 and Water, Physical and Health Impact Features
Spring,
WeII,1
Suction
Line,
Potable
Water
Supply
Cistem4
Potable
Water
Supply
Line 2
Structure
w/basement,
crawl space
or footing
drains
Structure
without 1
basement,
crawl
space or
footing
drains
Property
Lines,
Piped or
Lined
Irrigation
Ditch,
upslope
curtain
drain
Subsurface
Drain,
Intermittent
Irrigation
Lateral,
Drywell,
Stormwater
Structure
Lake,
Water
Course,
Irrigation
Ditch,
Stream,
Wetland
Dry Gulch,
Cut Bank,
Fill Area
(from Crest)
Septic Tank,
Higher level
treatment
Unit, Dosing
Tank, Vault
or Privy
Septic Tank,
Higher Level
Treatment Unit,
Dosing Tank, Vault
or Vault Privy
50 2
10 2
5
5
10
10
50
10
--
Building Sewer or
Effluent Lines
50 2
5 6
0
0
10 2
10 2
50 2
10 2
—
STA Trench, STA
Bed, Unlined Sand
Filter, Sub -surface
Dispersal System,
Seeoaoe Pit
100 3
25 2
20
10
10
25
50 3
25
5
Lined Sand Filter
60
10 2
15
10
10
10
25
10
5
Lined Evapo-
transpiration Field
or Outside of Berrn
of Lined
Wastewater Pond
60
10 2
15
15
10
10
25
10
5
Unlined Sand Filter
in Soil With a
100
25 2
15
15
10
25
25
15
10
Garfield requires that every OWTS be inspected by the to receive an occupancy
clearance for the new construction. Please make arrangements with the engineer to
schedule an inspection once the system is installed but before the bed is backfilled. The
installer is responsible to maintain the appropriate offsets and grades. Any deviation
from the plans must be approved by the engineer.
The recommendations contained in this report are made in a manner consistent with the
level of care and skill used by geotechnical engineers practicing in this area at this time.
This report contains no warranty either express or implied.
CAPSTONE ENTERPRISES WEST, LLC 10
JOB NUMBER 4546
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DESCRIPTION
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CAPSTONE
ENTERPRISES W EST, LLC
618 PARTEE DRIVE
GRAND JUNCTION, CO 81504
PHONE (970) 250-3331
martin@capstonewest.com
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OWTS GENERAL ARRANGEMENT
TRACT 37 ANTLERS ORCHARD
SILT, COLORADO
BY M W CHENOWETH
DATE 6119120
SCALE 1"=100.
PROJECT NO. 4546
SHEET NO.1 0F2
Max Depth
30Ft
Inspection Ports
Capped 12" Above Ground
UNCOMPACTED SOIL CAP
(MOUND 5%)
FILTER FABRIC OVER CHAMBERS
4" PERFORATED DISTRIBUTION LINES
ENTIRE LENGTH OF BED
PERFORATIONS DOWN
r
CONCRETE
TRUST BLOCK
Distribution Box
t 4 -
BED IN SECTION
BED MADE UP OF 90 QUICK -4 INFILTRATOR CHAMBERS (OR EQUIV.)
BED TO SLOPE DOWN 0.2% FROM D -BOX
Inspection Ports
12
00
REV. DATE
DESCRIPTION
BY
CK
CAPSTONE \
ENTERPRISES WEST, LLC
618 PARTEE DRIVE
GRAND JUNCTION, CO 81504
PHONE (970) 250-3331
martin@capstonewest.com
OWTS CONSTRUCTION DETAILS
TRACT 37 ANTLERS ORCHARD
SILT, COLORADO
BY M W CHENOWETH 'DATE 6/19/20
I SCALE NTS
PROJECT NO, 4s46
SHEET NO. 20F2