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December 6,2023
Ken Hopper
3447 County Road 103
Carbondale, Colorado 81 623
Project No. 23-7-630
Subject: Profile Pits and Laboratory Testing for On-Site Wastewater Treatment System
Design, 3447 County Road 103, Garfield County, Colorado
Mr. Hopper:
As requested, Kumar & Associates, Inc. observed profile pits dug at the subject site for the
OWTS design information. The observation was done in accordance with our agreement for
professional services to you, dated October 30,2023.
Two profile pits were excavated on November 2,2023 at the designated locations. The subsoil
profiles exposed in the pits, shown on Figure 1, consisted of about Yz foot of topsoil mainly
overlying relatively dense, silty to slightly clayey sandy basalt cobbles and boulders to the
bottom pit depths of 4% and 5 feet. Practical digging refusal was encountered on boulders.
No free water was observed in the pits and the soils were slightly moist.
Results of laboratory gradation testing performed on a disturbed sample of the minus 3-inch size
material taken from Pit l, presented on Figure 2,indicate the soils classifii as very gravelly sandy
loam.
If you have any questions or need further assistance, please call our office.
Sincerely,
a 15222
{i"x
Steven L. Pawlak, P
SLP/kac
Attachments: Figure I - Logs Exploratory Pits
Figure 2 - USDA Gradation Test Results
High Country Engineering - Dan Dennison (
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PROFILE PIT 1
SOUTH
PROFILE PIT 2
NORTH
0 0
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L.Jo
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I GRAVEL=52
SAND=36
SILT= 1 0
CLAY=2
5
LEGEND
TOPSOIL; ORGANIC SANDY SILT AND CLAY, DARK BROWN
SAND (SM_SC); VERY SILTY AND CLAYEY, SCATTERED BASALT COBBLES AND BOULDERS, MEDIUM
DENSE, SLIGHTLY MOIST, BROWN, MODERATELY BLOCKY.
BASALT COBBLES AND BOULDERS (SM-GM); SILTY SAND MATRIX, SLIGHTLY CLAYEY, DENSE,
sLtcHTLy MO|ST, LTGHT BROWN, CALCAREOUS, MASSIVE/GRANNULAR.
t DISTURBED BULK SAMPLE.
t PRACTICAL DIGGING REFUSAL ON BOULDERS.
NOTES
1. THE EXPLORATORY PITS WERE EXCAVATED WITH A BACKHOE ON NOVEMBER 2, 2023.
2. THE EXPLORATORY PITS WERE LOCATED BY THE CLIENT
3. THE ELEVATIONS OF THE EXPLORATORY PITS WERE NOT MEASURED AND THE LOGS OF THE
EXPLORATORY PITS ARE PLOTTED TO DEPTH.
4. THE EXPLORATORY PIT LOCATIONS SHOULD BE CONSIDERED ACCURATE ONLY TO THE DEGREE
IMPLIED BY THE METHOD USED.
5. THE LINES BETWEEN MATERIALS SHOWN ON THE EXPLORATORY PIT LOGS REPRESENT THE
APPROXIMATE BOUNDARIES BETWEEN MATERIAL TYPES AND THE TRANSITIONS MAY BE GRADUAL.
6. GROUNDWATER OR REDOXIMORPHIC FEATURES WERE NOT OBSERVED IN THE PITS AT THE TIME
OF EXCAVATION. PITS WERE BACKFILLED SUBSEQUENT TO SAMPLING.
7. LABORATORY TEST RESULTS:
GRAVEL= PERCENT RETAINED ON NO. 10 SIEVE;
SAND = PERCENT PASSING NO. 10 SIEVE AND RETAINED ON NO. 325 SIEVESILT = PERGENT PASSING NO. 525 SIEVE TO PARTICLE SIZE .002MM;
CLAY = PERCENT SMALLER THAN PARTICLE SIZE .0O2MM.
23-7-630 Kumar & Associates LOGS OF EXPLORATORY PITS Fig. 1
I
HYDROMETER ANALYSIS SIEVE ANALYSIS
U.S. STANDARD SERIES CLEAR SOUARE OPENINGS
24 HR. 7 HR 1 MIN.
#3254 MIN,100
10 90
20
30 70
oIJz.
FlrJE
Fztd(J
EIJo
40 60
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50 50
60 40
70 30
80 20
90 10
1m 0.001 .w2 106 .025 ,500 1,00 2w 4.75 9.5 19.0 37.5 76.2 152 m3
DIAMETER OF PARTICLES IN MILLIMETERS
CLAY COBBLES
GRAVEL 52 %SAND 36 7"SILT 10 %CLAY 2 o/o
USDA SOIL WPE: Very Gravelly Sandy Loam FROM: Profile Pit'1 @ 4'-4.5'
/
SILT V. FINE
23-7-630 Kumar & Associates USDA GRADATION TEST RESULTS Fig.2