HomeMy WebLinkAboutMONTAVA - PHASE E TOWN CENTER - BDR220003 - MONTAVA SUBMITTAL DOCUMENTS - ROUND 1 - GEOTECHNICAL (SOILS) REPORT (3)
4396 GREENFIELD DRIVE
W INDSOR, COLORADO 80550
(970) 545-3908 FAX (970) 663-0282
www.earth-engineering.com
July 26, 2022
Montava Development
430 N College Avenue, Suite 410
Fort Collins, Colorado 80524
Attn: Mr. Max Moss (Max@hf2m.com)
Re: Supplemental Subsurface Exploration Report
Montava Development – Approximate 800-Acre Mixed Use Development
South of LCR 52 and West of Anheuser Busch
Installation of 3 Groundwater Monitoring Wells
Fort Collins, Larimer County, Colorado
EEC Project No. 1172058
Mr. Moss:
Earth Engineering Consultants, LLC (EEC) personnel have completed the supplemental
subsurface exploration and the installation of the requested three (3) long-term groundwater
monitoring wells (MWs) at the general locations as “pre-selected” by Miller Groundwater
Engineering, LLC for the referenced project. The three (3) MWs were positioned west of
Interstate 25 (I-25) on the north side of the Canal Access Road as presented on the enclosed
“Google Earth – MW Location Diagram”. The purpose of our supplemental assessment was to
provide a mechanism to measure and evaluate the groundwater fluctuations and characteristics
across this portion of the Montava property as presented herein, to assist Miller Groundwater
Engineering, LLC in the evaluation of a possible area underdrain system. This supplemental
study was completed in general accordance with our proposal dated January 11, 2022.
EEC personnel had previously completed a preliminary subsurface exploration for the Montava
800-acre development property in 2017. The preliminary subsurface exploration conducted by
EEC in 2021 consisting of drilling a series of thirty (30) test borings throughout the property and
preparing a preliminary report with our findings. For further information and preliminary
recommendations based on the 2017 subsurface exploration, please refer to our Preliminary
Subsurface Exploration Report dated October 2, 2017, EEC Project No. 1172058.
For this phase of the project we understand the installation of the requested three (3) MWs,
registered with the State of Colorado – Division of Water Resources, will assist the design team
in evaluating the necessity and possible design of an area underdrain system for this portion of
Earth Engineering Consultants, LLC
EEC Project No. 1172058
Supplemental Subsurface Exploration Report – Montava Development
Fort Collins, Colorado
July 26, 2022
Page 2
the property in an effort to develop the site for possible below grade residential basement
construction.
SITE EXPLORATION AND TESTING PROCEDURES
As part of this study, EEC personnel completed three (3) MWs at the approximate “pre-selected”
locations by Miller Groundwater Engineering, LLC on the north side of the Canal Access Road,
west of I-25 as indicated on the site diagram included with this report. The borings were
extended to depths of approximately 20 feet below existing site grades. Upon completion of the
drilling operations, each boring was converted to an approximate 20-foot PVC cased monitoring
well for use to develop groundwater characteristics. Results of the field and laboratory testing
completed for this assessment are included with this report.
The MW exploratory boring locations were established in the field prior to drilling by EEC
personnel, with the assistance from Calvin Miller, P.E., PhD, with Miller Groundwater
Engineering, LLC, by use of a hand-held GPS unit and by pacing from identifiable site features
at locations accessible to our drilling equipment. The boring locations are presented on the
attached boring location diagram.
The soil borings were completed using a truck-mounted, CME 55 drill rig equipped with a
hydraulic head employed in drilling and sampling operations. The boreholes were advanced
using 4¼-inch nominal inside diameter (ID) hollow stem augers to maintain open boreholes for
sampling and PVC piezometer/pipe installation. Samples of the subsurface materials
encountered were obtained using the split-barrel/Standard Penetration Test (SPT) sampling
procedures in general accordance with ASTM Specifications D1586.
In the split-barrel sampling procedure, standard sampling spoons are driven into the ground by
means of a 140-pound hammer falling a distance of 30 inches. The number of blows required to
advance the split barrel sampler is recorded and is used to estimate the in-situ relative density of
cohesionless soils and, to a lesser degree of accuracy, the consistency of cohesive soils. All
samples obtained in the field were sealed and returned to our laboratory for further examination,
classification and testing.
Earth Engineering Consultants, LLC
EEC Project No. 1172058
Supplemental Subsurface Exploration Report – Montava Development
Fort Collins, Colorado
July 26, 2022
Page 3
After completing the drilling and sampling, and prior to removal of the hollow stem augers, PVC
casings were installed in the open boreholes through the hollow stem augers. Each MW was
constructed with 2-inch nominal diameter schedule 40 manufactured well screen and riser pipe.
In general, each MW consisted of an approximate 10-foot section of flush threaded slotted well
screen to depths as indicated on the enclosed boring log, with flush threaded solid riser pipe, as
required, to extend the MW to the above ground surface elevations. The screened portion of the
MW was backfilled with 10/20 silica sand, with an approximate 2-foot bentonite plug/seal placed
above the sand layer, and then backfilled with a blend of the auger cuttings generated and
bentonite to the existing ground surface elevations. The 2-inch diameter PVC casing was
extended to approximately 3 feet above existing site grades and a 4-inch by 4-inch by 4-foot in
length steel protective well cover, encased in a concrete apron was installed at the surface of
each MW. Cross-sectional schematics of the MW installations are indicated on the attached
boring logs.
The State of Colorado Division of Water Resources was notified of intent to construct
monitoring holes prior to beginning the field exploration. Copies of those notices with
acknowledgement from the State Engineer’s Office are available upon request. The well
construction and test reports will be provided to the Division of Water Resources including
copies of the boring logs provided with this report. If the monitoring wells (MWs) will remain in
place longer than 18 months, it will be necessary to notify the Division of Water Resources and
complete registration of those wells. Installation was completed by a licensed water well driller,
(Drilling Engineers of Fort Collins), and was completed in accordance with the water well
construction rules from the Division of Water Resources.
Laboratory testing completed on recovered samples included moisture content and visual
classification of the samples. Atterberg limits tests were completed on selected samples to
evaluate the soil’s plasticity. Washed sieve analyses were also completed on selected samples to
evaluate the grain size distribution of the subsurface materials encountered. The grain size
distribution samples were recovered in a standard split-barrel sampler so that any larger size
materials in the subsoils would be excluded from the test samples. Results of the outlined tests
are indicated on the attached boring logs and summary sheets.
As part of the testing program, all samples were examined in the laboratory by an engineer and
classified in accordance with the attached General Notes and the Unified Soil Classification
Earth Engineering Consultants, LLC
EEC Project No. 1172058
Supplemental Subsurface Exploration Report – Montava Development
Fort Collins, Colorado
July 26, 2022
Page 4
System, based on the soil’s texture and plasticity. The estimated group symbol for the Unified
Soil Classification System is indicated on the boring logs and a brief description of that
classification system is included with this report.
SUBSURFACE CONDITIONS
An EEC field engineer was on-site during drilling to direct the drilling activities and evaluate the
subsurface materials encountered. Field descriptions of the materials encountered were based on
visual and tactual observation of disturbed samples and auger cuttings. The boring/groundwater
monitoring logs included with this report may contain modifications to the field logs based on
results of laboratory testing and engineering evaluation. Based on results of the field and
laboratory evaluation, subsurface conditions can be generalized as follows.
In summary, the subsurface soils encountered in the supplemental borings/MWs generally
consisted of a relative shallow depth of overburden slightly cohesive subsoils classified as lean
clay with sand, underlain by a zone of fine to coarse granular subsoils, which extended to the
depths explored, approximately 20 feet below existing site grades. The lean clay with sand
native subsoils were encountered in each of the PVC cased borings beneath the surficial
topsoil/vegetative layer and extended to depths of approximately 7-1/2 to 9 feet below existing
site grades. Silty sand with gravel graded was encountered beneath the upper cohesive zone and
extended to the depths explored, approximately 19 to 20 feet below existing site grades. An
interbedded sandy lean clay lens was encountered at an approximate depth of 19 feet below site
grades in MW-2 and extended to the depths explored. The upper slightly cohesive subsoils were
generally moist to saturated in-situ, soft to medium stiff in consistency and exhibited low to
moderate plasticity. The granular zone was moist to wet, and loose to medium dense to dense
within increased depths in relative density.
The stratification boundaries indicated on the boring logs represent the approximate locations of
changes in soil and rock types; in-situ, the transition of materials may be gradual and indistinct.
GROUNDWATER OBSERVATIONS
Observations were made while drilling and after the completion of drilling to detect the presence
and level of free water. Subsequent groundwater measurements were also performed on July 15,
Earth Engineering Consultants, LLC
EEC Project No. 1172058
Supplemental Subsurface Exploration Report – Montava Development
Fort Collins, Colorado
July 26, 2022
Page 5
2022. Groundwater and/or the presence of a piezometric water surface, was generally observed
at depths ranging from approximately 8 to 9½ feet below ground surface as indicated on the
enclosed boring logs. The measured depths to groundwater are recorded near the upper right-
hand corner of each boring log included with this report. Groundwater measurements provided
with this report are indicative of groundwater levels at the locations and at the time the
borings/groundwater measurements were completed.
Perched and/or trapped water may be encountered in more permeable zones in the subgrade soils
at different times throughout the year. Perched water is commonly encountered in soils
immediately overlying less permeable clay zones or seams. Fluctuations in ground water levels
and in the location and amount of perched/trapped water may occur over time depending on
variations in hydrologic conditions, irrigation activities on this and surrounding properties and
other conditions not apparent at the time of this report.
ANALYSIS AND RECOMMENDATIONS
Preliminary Basement Design and Construction
We provide the following information to assist the ownership group and/or the civil design
engineers in the determination if an area wide underdrain system is required to allow for
basement construction across the Montava Development. Groundwater was encountered across
the site within the three (3) supplemental MW/borings at approximate depths of 8 to 9½ feet
below existing site grades. If lower level construction for full-depth basements is being
considered for the site, we would suggest that the lower level subgrade(s) be placed a minimum
of 3 feet above maximum anticipated rise in groundwater levels, or a combination exterior and
interior perimeter drainage system(s) be installed.
Consideration could also be given to 1) either designing and installing an area underdrain system
to lower the groundwater levels provided a gravity discharge point can be established. If a
gravity outlet/system cannot be designed another consideration would be to design and install a
mechanical sump pump system to discharge the collected groundwater within the underdrain
system, or 2) elevate/raise the site grades to establish the minimum required four (4) foot
separation to the maximum anticipated rise in groundwater. EEC is available to assist in the
underdrain design if requested.
Earth Engineering Consultants, LLC
EEC Project No. 1172058
Supplemental Subsurface Exploration Report – Montava Development
Fort Collins, Colorado
July 26, 2022
Page 6
The following information should be considered, which was previously mentioned, would be to
install an interior and exterior perimeter drainage system for each individual residence,
regardless if an area wide underdrain system were to be designed and installed. To reduce the
potential for groundwater to enter the lower level/basement area of the structure(s), installation
of a dewatering system for each residence is recommended. The dewatering system should, at a
minimum, include an underslab gravel drainage layer sloped to an interior perimeter drainage
system. The following provides design recommendations for both interior and exterior perimeter
drainage systems for each residence.
The underslab drainage system should consist of a properly sized perforated pipe, embedded in
free-draining gravel, placed in a trench at least 12 inches in width. The trench should be inset
from the interior edge of the nearest foundation a minimum of 12 inches. In addition, the trench
should be located such that an imaginary line extending downward at a 45-degree angle from the
foundation does not intersect the nearest edge of the trench. Gravel should extend a minimum of
3 inches beneath the bottom of the pipe. The underslab drainage system should be sloped at a
minimum 1/8-inch per foot to a suitable outlet, such as a sump and pump system.
The underslab drainage layer should consist of a minimum 6-inch thickness of free-draining
gravel meeting the specifications of ASTM C33, Size No. 57 or 67 or equivalent. Cross-
connecting drainage pipes should be provided beneath the slab at minimum 15-foot intervals and
should discharge to the perimeter drainage system.
Sizing of drainage pipe will be dependent upon groundwater flow into the dewatering system.
Groundwater flow rates will fluctuate with permeability of the soils to be dewatered and the
depth to which groundwater may rise in the future. Pump tests to determine groundwater flow
rates are recommended in order to properly design the system. For preliminary design purposes,
the drainage pipe, sump and pump system should be sized for a projected flow of 0.5 x 10-3 cubic
feet per second (cfs) per lineal foot of drainage pipe. Additional recommendations can be
provided upon request and should be presented in final subsurface exploration reports for each
residential lot.
To reduce the potential for surface water infiltration from impacting foundation bearing soils
and/or entering any planned below grade portion of any residential structure, installation of an
exterior perimeter drainage system is recommended. This drainage system should be constructed
Earth Engineering Consultants, LLC
EEC Project No. 1172058
Supplemental Subsurface Exploration Report – Montava Development
Fort Collins, Colorado
July 26, 2022
Page 7
around the exterior perimeter of the lower level/below grade foundation system and sloped at a
minimum 1/8-inch per foot to a suitable outlet, such as a sump and pump system.
The exterior drainage system should consist of a properly sized perforated pipe, embedded in
free-draining gravel, placed in a trench at least 12 inches in width. Gravel should extend a
minimum of 3 inches beneath the bottom of the pipe, and at least 2 feet above the bottom of the
foundation wall. The system should be underlain with a polyethylene moisture barrier, sealed to
the foundation walls, and extended at least to the edge of the backfill zone. The gravel should be
covered with drainage fabric prior to placement of foundation backfill.
Other Considerations and Recommendations
Groundwater was observed at an approximate depth of 8½ to 9½ feet below present site grades.
Excavations extending to the wetter soils could create difficulties for backfilling of the
utility/pipe trenches with drying of the subgrade soils required to use those materials as backfill.
In general, the subgrade soils could be used as backfill soils although care will be necessary to
maintain sufficient moisture to reduce potential for post-construction movement.
Excavations into the on-site soils will encounter a variety of conditions. Excavations into the
clays can be expected to stand on relatively steep temporary slopes during construction;
however, caving soils may also be encountered within the underlying granular soils, especially in
close proximity to the groundwater table. Groundwater seepage should also be anticipated for
utility excavations. Pumping from sumps may be utilized to control water within the
excavations. Well points may be required for significant groundwater flow, or where
excavations penetrate groundwater to a significant depth. The individual contractor(s) should be
made responsible for designing and constructing stable, temporary excavations as required to
maintain stability of both the excavation sides and bottom. All excavations should be sloped or
shored in the interest of safety following local and federal regulations, including current OSHA
excavation and trench safety standards.
GENERAL COMMENTS
The analysis and information presented in this report is based upon the data obtained from the
soil borings performed at the indicated locations as discussed in this report. This report does not
Earth Engineering Consultants, LLC
DRILLING AND EXPLORATION
DRILLING & SAMPLING SYMBOLS:
SS: Split Spoon ‐ 13/8" I.D., 2" O.D., unless otherwise noted PS: Piston Sample
ST: Thin‐Walled Tube ‐ 2" O.D., unless otherwise noted WS: Wash Sample
R: Ring Barrel Sampler ‐ 2.42" I.D., 3" O.D. unless otherwise noted
PA: Power Auger FT: Fish Tail Bit
HA: Hand Auger RB: Rock Bit
DB: Diamond Bit = 4", N, B BS: Bulk Sample
AS: Auger Sample PM: Pressure Meter
HS: Hollow Stem Auger WB: Wash Bore
Standard "N" Penetration: Blows per foot of a 140 pound hammer falling 30 inches on a 2‐inch O.D. split spoon, except where noted.
WATER LEVEL MEASUREMENT SYMBOLS:
WL : Water Level WS : While Sampling
WCI: Wet Cave in WD : While Drilling
DCI: Dry Cave in BCR: Before Casing Removal
AB : After Boring ACR: After Casting Removal
Water levels indicated on the boring logs are the levels measured in the borings at the time indicated. In pervious soils, the indicated
levels may reflect the location of ground water. In low permeability soils, the accurate determination of ground water levels is not
possible with only short term observations.
DESCRIPTIVE SOIL CLASSIFICATION
Soil Classification is based on the Unified Soil Classification
system and the ASTM Designations D‐2488. Coarse Grained
Soils have move than 50% of their dry weight retained on a
#200 sieve; they are described as: boulders, cobbles, gravel or
sand. Fine Grained Soils have less than 50% of their dry weight
retained on a #200 sieve; they are described as : clays, if they
are plastic, and silts if they are slightly plastic or non‐plastic.
Major constituents may be added as modifiers and minor
constituents may be added according to the relative
proportions based on grain size. In addition to gradation,
coarse grained soils are defined on the basis of their relative in‐
place density and fine grained soils on the basis of their
consistency. Example: Lean clay with sand, trace gravel, stiff
(CL); silty sand, trace gravel, medium dense (SM).
CONSISTENCY OF FINE‐GRAINED SOILS
Unconfined Compressive
Strength, Qu, psf Consistency
< 500 Very Soft
500 ‐ 1,000 Soft
1,001 ‐ 2,000 Medium
2,001 ‐ 4,000 Stiff
4,001 ‐ 8,000 Very Stiff
8,001 ‐ 16,000 Very Hard
RELATIVE DENSITY OF COARSE‐GRAINED SOILS:
N‐Blows/ft Relative Density
0‐3 Very Loose
4‐9 Loose
10‐29 Medium Dense
30‐49 Dense
50‐80 Very Dense
80 + Extremely Dense
PHYSICAL PROPERTIES OF BEDROCK
DEGREE OF WEATHERING:
Slight Slight decomposition of parent material on
joints. May be color change.
Moderate Some decomposition and color change
throughout.
High Rock highly decomposed, may be extremely
broken.
HARDNESS AND DEGREE OF CEMENTATION:
Limestone and Dolomite:
Hard Difficult to scratch with knife.
Moderately Can be scratched easily with knife.
Hard Cannot be scratched with fingernail.
Soft Can be scratched with fingernail.
Shale, Siltstone and Claystone:
Hard Can be scratched easily with knife, cannot be
scratched with fingernail.
Moderately Can be scratched with fingernail.
Hard
Soft Can be easily dented but not molded with
fingers.
Sandstone and Conglomerate:
Well Capable of scratching a knife blade.
Cemented
Cemented Can be scratched with knife.
Poorly Can be broken apart easily with fingers.
Cemented
Group
Symbol
Group Name
Cu≥4 and 1<Cc≤3E GW Well-graded gravel F
Cu<4 and/or 1>Cc>3E GP Poorly-graded gravel F
Fines classify as ML or MH GM Silty gravel G,H
Fines Classify as CL or CH GC Clayey Gravel F,G,H
Cu≥6 and 1<Cc≤3E SW Well-graded sand I
Cu<6 and/or 1>Cc>3E SP Poorly-graded sand I
Fines classify as ML or MH SM Silty sand G,H,I
Fines classify as CL or CH SC Clayey sand G,H,I
inorganic PI>7 and plots on or above "A" Line CL Lean clay K,L,M
PI<4 or plots below "A" Line ML Silt K,L,M
organic Liquid Limit - oven dried Organic clay K,L,M,N
Liquid Limit - not dried Organic silt K,L,M,O
inorganic PI plots on or above "A" Line CH Fat clay K,L,M
PI plots below "A" Line MH Elastic Silt K,L,M
organic Liquid Limit - oven dried Organic clay K,L,M,P
Liquid Limit - not dried Organic silt K,L,M,O
Highly organic soils PT Peat
(D30)2
D10 x D60
GW-GM well graded gravel with silt NPI≥4 and plots on or above "A" line.
GW-GC well-graded gravel with clay OPI≤4 or plots below "A" line.
GP-GM poorly-graded gravel with silt PPI plots on or above "A" line.
GP-GC poorly-graded gravel with clay QPI plots below "A" line.
SW-SM well-graded sand with silt
SW-SC well-graded sand with clay
SP-SM poorly graded sand with silt
SP-SC poorly graded sand with clay
Earth Engineering Consultants, LLC
IIf soil contains >15% gravel, add "with gravel" to
group name
JIf Atterberg limits plots shaded area, soil is a CL-
ML, Silty clay
Unified Soil Classification System
Soil Classification
Criteria for Assigning Group Symbols and Group Names Using Laboratory Tests
Sands 50% or more
coarse fraction
passes No. 4 sieve
Fine-Grained Soils
50% or more passes
the No. 200 sieve
<0.75 OL
Gravels with Fines
more than 12%
fines
Clean Sands Less
than 5% fines
Sands with Fines
more than 12%
fines
Clean Gravels Less
than 5% fines
Gravels more than
50% of coarse
fraction retained on
No. 4 sieve
Coarse - Grained Soils
more than 50%
retained on No. 200
sieve
CGravels with 5 to 12% fines required dual symbols:
Kif soil contains 15 to 29% plus No. 200, add "with sand"
or "with gravel", whichever is predominant.
<0.75 OH
Primarily organic matter, dark in color, and organic odor
ABased on the material passing the 3-in. (75-mm)
sieve
ECu=D60/D10 Cc=
HIf fines are organic, add "with organic fines" to
group name
LIf soil contains ≥ 30% plus No. 200 predominantly sand,
add "sandy" to group name.
MIf soil contains ≥30% plus No. 200 predominantly gravel,
add "gravelly" to group name.
DSands with 5 to 12% fines require dual symbols:
BIf field sample contained cobbles or boulders, or
both, add "with cobbles or boulders, or both" to
group name.FIf soil contains ≥15% sand, add "with sand" to
GIf fines classify as CL-ML, use dual symbol GC-
CM, or SC-SM.
Silts and Clays
Liquid Limit less
than 50
Silts and Clays
Liquid Limit 50 or
more
0
10
20
30
40
50
60
0 10 20 30 40 50 60 70 80 90 100 110PLASTICITY INDEX (PI) LIQUID LIMIT (LL)
ML OR OL
MH OR OH
For Classification of fine-grained soils and
fine-grained fraction of coarse-grained
soils.
Equation of "A"-line
Horizontal at PI=4 to LL=25.5
then PI-0.73 (LL-20)
Equation of "U"-line
Vertical at LL=16 to PI-7,
then PI=0.9 (LL-8)
CL-ML
MONTAVA DEVELOPMENT MONITOR WELLS
FORT COLLINS, COLORADO
EEC PROJECT NO. 1172058
JUNE 2022
M o ntava Develo pmen t - Su p plemental Groun dw ater Stu d y - Fort Collin s, Colo rado
Approxim ate locations for three (3) Groundwater Monitorings W ells (MW s ) ins talled on June 28, 2022 as per Miller Groundwater Engineering
1000 ft
N➤➤N
2 1/2" (63 mm)
2" (50 mm)
1 1/2" (37.5 mm)
1" (25 mm)
3/4" (19 mm)
1/2" (12.5 mm)
3/8" (9.5 mm)
No. 4 (4.75 mm)
No. 8 (2.36 mm)
No. 10 (2 mm)
No. 16 (1.18 mm)
No. 30 (0.6 mm)
No. 40 (0.425 mm)
No. 50 (0.3 mm)
No. 100 (0.15 mm)
No. 200 (0.075 mm)
Project: Montava Development
Location: Fort Collins, Colorado
Project No: 1172058
Sample ID: MW-1, Sample 2 - Depth 9-feet
Sample Desc.: Sandy Lean Clay (CL)
Date: July 2022
100
98
95
81
56.0
94
93
91
90
89
100
100
100
100
100
EARTH ENGINEERING CONSULTANTS, LLC
SUMMARY OF LABORATORY TEST RESULTS
Sieve Analysis (AASHTO T 11 & T 27 / ASTM C 117 & C 136)
100
Sieve Size Percent Passing
EARTH ENGINEERING CONSULTANTS, LLCSummary of Washed Sieve Analysis Tests (ASTM C117 & C136)Date:Project:Location:Project No:Sample ID:Sample Desc.:CobbleSilt or ClayGravelCoarse FineSandCoarse MediumJuly 20229.50 0.09 ---Montava Development Fort Collins, Colorado1172058MW-1, Sample 2 - Depth 9-feetSandy Lean Clay (CL)D100D60D50‐‐‐ ‐‐‐Fine‐‐‐ ‐‐‐D30D10CuCC6"5"4"3"2.5"2"1.5"1"3/4"1/2"3/8"No. 4No. 8No. 10No. 16No. 30No. 40No. 50No. 100No. 20001020304050607080901000.010.11101001000Finer by Weight (%)Grain Size (mm)Standard Sieve Size
2 1/2" (63 mm)
2" (50 mm)
1 1/2" (37.5 mm)
1" (25 mm)
3/4" (19 mm)
1/2" (12.5 mm)
3/8" (9.5 mm)
No. 4 (4.75 mm)
No. 8 (2.36 mm)
No. 10 (2 mm)
No. 16 (1.18 mm)
No. 30 (0.6 mm)
No. 40 (0.425 mm)
No. 50 (0.3 mm)
No. 100 (0.15 mm)
No. 200 (0.075 mm)
Project: Montava Development
Location: Fort Collins, Colorado
Project No: 1172058
Sample ID: MW-1, Sample 3 - Depth 14-feet
Sample Desc.: Well Graded Sand with Gravel (SW)
Date: July 2022
93
81
60
8
1.1
55
39
22
17
14
100
100
100
100
95
EARTH ENGINEERING CONSULTANTS, LLC
SUMMARY OF LABORATORY TEST RESULTS
Sieve Analysis (AASHTO T 11 & T 27 / ASTM C 117 & C 136)
100
Sieve Size Percent Passing
EARTH ENGINEERING CONSULTANTS, LLCSummary of Washed Sieve Analysis Tests (ASTM C117 & C136)Date:Project:Location:Project No:Sample ID:Sample Desc.:CobbleSilt or ClayGravelCoarse FineSandCoarse MediumJuly 202219.00 2.33 1.73Montava Development Fort Collins, Colorado1172058MW-1, Sample 3 - Depth 14-feetWell Graded Sand with Gravel (SW) D100D60D500.87 0.20Fine11.89 1.66D30D10CuCC6"5"4"3"2.5"2"1.5"1"3/4"1/2"3/8"No. 4No. 8No. 10No. 16No. 30No. 40No. 50No. 100No. 20001020304050607080901000.010.11101001000Finer by Weight (%)Grain Size (mm)Standard Sieve Size
2 1/2" (63 mm)
2" (50 mm)
1 1/2" (37.5 mm)
1" (25 mm)
3/4" (19 mm)
1/2" (12.5 mm)
3/8" (9.5 mm)
No. 4 (4.75 mm)
No. 8 (2.36 mm)
No. 10 (2 mm)
No. 16 (1.18 mm)
No. 30 (0.6 mm)
No. 40 (0.425 mm)
No. 50 (0.3 mm)
No. 100 (0.15 mm)
No. 200 (0.075 mm)
Project: Montava Development
Location: Fort Collins, Colorado
Project No: 1172058
Sample ID: MW-2, Sample 3 - Depth 14-feet
Sample Desc.: Well Graded Sand with Gravel (SW)
Date: July 2022
88
67
40
5
4.4
35
22
11
9
7
100
100
100
100
93
EARTH ENGINEERING CONSULTANTS, LLC
SUMMARY OF LABORATORY TEST RESULTS
Sieve Analysis (AASHTO T 11 & T 27 / ASTM C 117 & C 136)
100
Sieve Size Percent Passing
EARTH ENGINEERING CONSULTANTS, LLCSummary of Washed Sieve Analysis Tests (ASTM C117 & C136)Date:Project:Location:Project No:Sample ID:Sample Desc.:CobbleSilt or ClayGravelCoarse FineSandCoarse MediumJuly 202219.00 4.11 3.23Montava Development Fort Collins, Colorado1172058MW-2, Sample 3 - Depth 14-feetWell Graded Sand with Gravel (SW) D100D60D501.70 0.52Fine7.84 1.34D30D10CuCC6"5"4"3"2.5"2"1.5"1"3/4"1/2"3/8"No. 4No. 8No. 10No. 16No. 30No. 40No. 50No. 100No. 20001020304050607080901000.010.11101001000Finer by Weight (%)Grain Size (mm)Standard Sieve Size
2 1/2" (63 mm)
2" (50 mm)
1 1/2" (37.5 mm)
1" (25 mm)
3/4" (19 mm)
1/2" (12.5 mm)
3/8" (9.5 mm)
No. 4 (4.75 mm)
No. 8 (2.36 mm)
No. 10 (2 mm)
No. 16 (1.18 mm)
No. 30 (0.6 mm)
No. 40 (0.425 mm)
No. 50 (0.3 mm)
No. 100 (0.15 mm)
No. 200 (0.075 mm)
Project: Montava Development
Location: Fort Collins, Colorado
Project No: 1172058
Sample ID: MW-2, Sample 4 - Depth 19-feet
Sample Desc.: Sandy Lean Clay (CL)
Date: July 2022
100
100
100
76
50.0
100
100
99
98
94
100
100
100
100
100
EARTH ENGINEERING CONSULTANTS, LLC
SUMMARY OF LABORATORY TEST RESULTS
Sieve Analysis (AASHTO T 11 & T 27 / ASTM C 117 & C 136)
100
Sieve Size Percent Passing
EARTH ENGINEERING CONSULTANTS, LLCSummary of Washed Sieve Analysis Tests (ASTM C117 & C136)Date:Project:Location:Project No:Sample ID:Sample Desc.:CobbleSilt or ClayGravelCoarse FineSandCoarse MediumJuly 20222.00 0.10 ---Montava Development Fort Collins, Colorado1172058MW-2, Sample 4 - Depth 19-feetSandy Lean Clay (CL)D100D60D50‐‐‐ ‐‐‐Fine‐‐‐ ‐‐‐D30D10CuCC6"5"4"3"2.5"2"1.5"1"3/4"1/2"3/8"No. 4No. 8No. 10No. 16No. 30No. 40No. 50No. 100No. 20001020304050607080901000.010.11101001000Finer by Weight (%)Grain Size (mm)Standard Sieve Size
2 1/2" (63 mm)
2" (50 mm)
1 1/2" (37.5 mm)
1" (25 mm)
3/4" (19 mm)
1/2" (12.5 mm)
3/8" (9.5 mm)
No. 4 (4.75 mm)
No. 8 (2.36 mm)
No. 10 (2 mm)
No. 16 (1.18 mm)
No. 30 (0.6 mm)
No. 40 (0.425 mm)
No. 50 (0.3 mm)
No. 100 (0.15 mm)
No. 200 (0.075 mm)
Project: Montava Development
Location: Fort Collins, Colorado
Project No: 1172058
Sample ID: MW-3, Sample 2 - Depth 9-feet
Sample Desc.: Silty Sand with Gravel (SM)
Date: July 2022
96
84
69
15
11.3
66
55
37
29
23
100
100
100
100
99
EARTH ENGINEERING CONSULTANTS, LLC
SUMMARY OF LABORATORY TEST RESULTS
Sieve Analysis (AASHTO T 11 & T 27 / ASTM C 117 & C 136)
100
Sieve Size Percent Passing
EARTH ENGINEERING CONSULTANTS, LLCSummary of Washed Sieve Analysis Tests (ASTM C117 & C136)Date:Project:Location:Project No:Sample ID:Sample Desc.:CobbleSilt or ClayGravelCoarse FineSandCoarse MediumJuly 202219.00 1.55 1.01Montava Development Fort Collins, Colorado1172058MW-3, Sample 2 - Depth 9-feetSilty Sand with Gravel (SM) D100D60D500.45‐‐‐Fine‐‐‐ ‐‐‐D30D10CuCC6"5"4"3"2.5"2"1.5"1"3/4"1/2"3/8"No. 4No. 8No. 10No. 16No. 30No. 40No. 50No. 100No. 20001020304050607080901000.010.11101001000Finer by Weight (%)Grain Size (mm)Standard Sieve Size