HomeMy WebLinkAboutOWTS Design - REVISED 09.18.2024129 Cains Lane
Carbondale, CO 81623
970.309.5259
carla.ostberg@gmail.com
September 26, 2024 Project No. C1882
Lindsay Gurley
ljgurley@gmail.com
Subsurface Investigation and Onsite Wastewater Treatment System Design
2-Bedroom Residence
1319 CR 127
Garfield County, Colorado
Lindsay,
CBO Inc. performed a subsurface investigation and completed an onsite wastewater treatment system
(OWTS) design for the subject residence. The 35-acre property is located outside of Glenwood Springs,
in an area where OWTSs are necessary. The previous location and configuration of the soil treatment
area (STA) has been modified from our original design documents dated May 24, 2024 to meet setbacks
to the existing and new portions of the water line. Previous design documents should be discarded and
replaced with these design documents dated September 26, 2024.
Legal Description:
Section: 28 Township: 6 Range: 89 A TR IN NW1/4 AND NWNE 35 ACRES
Parcel ID: 2185-282-00-024
SITE CONDITIONS The property is currently developed with a 3-bedroom residence. The residence has been removed and
replaced with a 2-bedroom residence with a smaller footprint.
The permit (enclosed) was provided by Garfield County Community Development Department. The
subject OWTS consists of one 1000-gallon, two-compartment concrete septic tank followed by a STA
comprised of 26 ‘Standard’ Infiltrator® chambers for a total of 487.5 square feet of infiltrative area.
Individual Sewage Disposal System (ISDS) Permit 1717 documents the system installation. The system
was sized to accommodate 3 bedrooms. The permit received final approval on October 25, 1989.
While the septic tank is located on the site plan, it is difficult to determine the exact location of the existing
STA. There does not appear to be sufficient space on the property to accommodate an STA of the size
indicated on the original permit. We speculate there could be trenches on the hillside to the south based
on the direction of the piping exiting the septic tank. However, the hillside is extremely steep with limited
space and the water line also runs in that direction. The only other potential location for the STA is the
driveway. Attempts to camera the existing sewer line when the OWTS was in use were unproductive. It
is possible the existing STA encroached on setbacks to the water line and/or the foundation of the
previous residence.
The residence is served by a community water system. The water line was recently located and a tap
created in the driveway. A new portion of water line was installed from the tap into the southwest side of
the new residence. We have approximated the existing water line path down the hillside to the south.
The water line must be at least 25-feet from the proposed soil treatment area (STA), 10-feet from the
proposed septic tank, and 5-feet from the proposed sewer line.
Page 2
The proposed STA location is relatively flat and parallels the house to the east. This is the only area that
can accommodate the STA while meeting the setbacks to the water line. The house foundation is a
shallow crawl space; however, the required 20-foot setback cannot be met without dropping over the
steep hillside to the east 1. The STA will not come closer to the foundation than 10-feet. This reduction in
setback will have no adverse impacts on the foundation or functioning of the STA. The depth of the
foundation is relatively shallow, approximately 4-feet in depth (2-feet below current native grade). The
STA will be placed downgradient of the foundation to the east. The STA will be pressure dosed, applying
approximately 50 gallons of water per dose to each zone of the STA, sprayed evenly throughout the field
which should allow the soils to accept the effluent without creating saturated conditions. Pressure
distribution also allows soils resting time between doses. Additionally, roof drains and perimeter drains
will be utilized to direct storm water away from the house and OWTS.
View of foundation looking southwest View of foundation and house looking southwest
While there will be an encroachment on the foundation setback, the site is constrained, and the new
residence will have only 2-bedrooms where the previous residence had 3-bedrooms. Also, the setback
to the water line will be maintained by the new OWTS where previously this setback was not met.
There should be no traffic or staging of material over the future STA site to avoid compaction of soils
prior to construction of the STA.
1 Garfield County On-Site Wastewater Treatment System Regulation 43. Table 7-1 Note: “For repair
or upgrading of existing OWTS where the size of lot precludes adherence to these distances, a repaired
OWTS must not be closer to setback features than the existing OWTS, as reviewed and approved by the local
public health agency.” In this case, the encroachment on the water line is being remedied while the setback to
foundation will be less.
Page 3
SUBSURFACE
The subsurface was investigated by Kumar and Associates, Project No. 21-7-112 and is documented in a
report dated February 5, 2021 (enclosed). One soil boring was drilled in the driveway near the existing
house foundation and was sampled for the evaluation. The boring consisted of 6-inches of base
(aggregate), underlain by fill to 3-feet, underlain by gravel and sand to 6-feet, underlain by sandstone
bedrock to a maximum depth explored of 16.5-feet.
With the presence of bedrock at 6-feet and limited space available on the property for construction of the
STA, we are proposing a pressure-dosed, over-excavated, unlined sand filter with 3-feet of sand filter
material (Secondary Sand). A long term acceptance rate (LTAR) of 0.8 gallons per square foot will
be used to design the OWTS.
DESIGN SPECIFICATIONS The existing septic tank will be abandoned by pumping the tank and removing it. The existing STA will
be abandoned in place (location unknown).
Design Calculations:
Average Design Flow = 75 GPD x 2 people/bedroom x 2 Bedrooms = 300 GPD
LTAR = 0.8 GPD/SF
300 GPD / 0.8 GPD/SF = 375 SF
The OWTS design is based on 2-bedrooms. An average daily wastewater flow of 300 GPD will be used.
For the purposes of this OWTS design, Benchmark Elevation has been established as 100’ (Finished
Floor). CBO Inc. should be notified of any discrepancies or problems with grade elevations of proposed
components during installation of the OWTS.
OWTS Component Minimum Elevation
Primary Tank Inlet Invert Approximate horizontal distance 31’ / min. 2% fall
/ min. 7.75” fall
Automatic Distributing Valve Approximate horizontal distance 50’ / min. 1% rise
/ min. 6.25” rise
Infiltrative Surface Approximate horizontal distance 5’ / min. 1% fall
to STA / min. 0.625” fall
*Elevations are based upon standard OWTS installation practices. Component elevations may change during
installation due to site conditions. Minimum grade refers to piping between components.
The 4-inch SDR-35 sewer line exiting the residence must have a double-sweep clean out and a minimum
2% grade to the septic tank. Any area subject to traffic must be minimum Schedule 40 sewer line.
The system installation will include a 1000-gallon, two-compartment Valley Precast concrete septic with
an Orenco® Biotube Pump Vault and an Orenco® PF3005 pump in the second compartment. The floats
should be set to dose approximately 54 gallons each pump cycle, allowing approximately 5 gallons of
drain back. The control panel for the pump must be located within line of sight of the septic tank. An
electrician will be responsible for wiring the pumping system and the contractor will be responsible for
connecting the plumbing. This office should be contacted for start up of the system to verify its functioning
and to perform a squirt test prior to use of the system.
Page 4
Pump Table
Dose Range Max = 80 gal. (300 GPD x 25%
+ 5 gal drain back)
Min. 29 gal. (6 gal x 4) + 5 gal
drain back
Dose Setting 54 gallons/dose 5 gallons drain back (50’ / 1.5”
diameter pump line)
Float Separation 1000 gallon two-compartment
Valley Precast concrete septic
tank
8” on/off float separation
Pump Criteria 17.6 gallons per minute (GPM) 15.3 feet total dynamic head
(TDH)
Effluent will be pumped through a 1.5-inch diameter pump line from the pump chamber to an Orenco®
automatic distributing valve (ADV), model 6402. This pump line must have a minimum 1% grade for proper
drain back into the tank after each pump cycle. The ADV must be placed at a high point in the system in an
insulated riser with access from grade. Screened rock must be placed below the ADV to support the ADV
and to assure the clear pipes exiting the ADV remain visible for future inspection and maintenance.
Effluent will be pressure dosed to through 1.5-inch diameter distribution lines to two 7’ x 26’ 10” beds. A
minimum of 3-feet of sand filter material will be installed in the over-excavated footprint. Sand filter material
must be clean, coarse sand, all passing a screen having four meshes to the inch. The sand must have an
effective size between 0.15 and 0.60 mm. The uniformity coefficient must be 7.0 or less. Material meeting
ASTM 33, for concrete sand, with three percent or less fines passing 200 mesh sieve may be used. A
gradation of the sand media must be submitted to this office prior to obtaining the sand.
The ends and downhill sides of the sand filters (inside the excavation and outside of the sand
filters) must be lined with a 30 mil PVC liner to prevent lateral migration of effluent toward the
steep hillside.
Laterals must be 1.5-inches in diameter with 5/32-inch diameter orifices facing down, spaced 2-feet on
center, installed on the GeoMat™ with the filter fabric over the laterals. Laterals should be placed 2-feet
from the edges of the bed with 3.0-feet between the laterals. Laterals will be connected with 1.5-inch
diameter level manifolds. Two 39” wide GeoMats™ must be placed on the 7-foot wide beds. All material
associated with the GeoMat™ installation must be proprietary products associated with the GeoMat™,
including orifice shields and geotextile fabric. Manufacturer instructions must be followed regarding
installation of the GeoMat™.
Each 1.5-inch diameter lateral must end in a sweeping ell facing up with a ball valve for flushing. Valves
should be placed in a 10-inch sprinkler box for access. Laterals must be covered by a soil separation
fabric and at least 1-foot of topsoil or other suitable soil able to support vegetative growth. There shall be no
cobble-sized (>2.5”) or greater rock in final cover over the GeoMat™. Inspection ports must be placed at
each corner of each bed. Ports may be cut to grade and covered with a valve box for access.
COMPONENT SPECIFICATIONS
The component manufacturers are typical of applications used by contractors and engineers in this area.
CBO Inc. must approve alternative components prior to installation of the OWTS. Requests must
be submitted, in writing, to our office for approval prior to installation. Component technical data
sheets are available upon request.
Page 5
COMPONENT MANUFACTURER MODEL NO. COMMENTS
Septic Tank
Valley Precast
Item # 1000T-2CP-HH
1000-gallon, two-
compartment concrete
septic tank with high
head pump
Pump Orenco® PF300511 ½ HP
120 Volt
Biotube ProPak Pump Package Orenco® BPP30DD Vault, Filter, Control Panel (demand dose)
Tank Risers and Lids Orenco® Double-walled PVC Risers and Lids (24” diameter)
ADV Orenco® V6402A 1.5” Inlet and Outlets
ADV Riser and Lid Orenco® Double-walled PVC Risers
and Lids (30” diameter) Flushing Assembly Orenco® 1.5” diameter (2) 45° or 90° long sweep only (4 total) GeoMat™ GeoMatrix Systems, LLC 108 linear feet 39” wide GeoMat™ and 48 orifice shields PVC Pond Liner 30 MIL 68’ long, 3’ deep
Construction must be according to the jurisdiction’s adopted On-Site Wastewater Treatment System
Regulations, the OWTS Permit, and this design.
PERMIT APPLICATION INSTRUCTIONS
An OWTS Permit Application must be submitted to Garfield County Environmental Health Department.
https://www.garfield-county.com/environmental-health/filesgcco/sites/16/OWTS-Application-Complete-
Packet-Dec.-2019.pdf. If the OWTS Permit Application will be submitted with a Building Permit
Application, it should be submitted directly to Garfield County Building Department.
All questions regarding permit submission can be directed to Garfield County Environmental Health
Department, 970-945-6614 x8150.
INSTALLATION CONTRACTOR
CBO Inc. expects that the installer be experienced and qualified to perform the scope of work outlined in this
design. The installer must review this design thoroughly and coordinate with our office in advance of
installation. Any additional conditions in this design or county permit must be completed and documented
prior to final approval of the OWTS installation. Communication between the installer and this office is
expected throughout the installation.
INSTALLATION OBSERVATIONS CBO Inc. must view the OWTS during construction. The OWTS observation should be performed before
backfill, after placement of OWTS components. Septic tanks, distribution devices, pumps, dosing siphons,
and other plumbing, as applicable, must also be observed. CBO Inc. should be notified 48 hours in advance
to observe the installation.
In an effort to improve the accuracy of the record drawing, we request that the installer provide a
sketch of the installation, including path of the sewer lines, water line installation (if applicable),
septic tank location, STA location, and measurements from building corners or another fixed
Page 6
objects on the property. This sketch is most easily provided on Sheet W2.0 of the OWTS Design
Packet. Photographs of the installation and final cover are also requested to supplement our installation
documentation.
REVEGETATION REQUIREMENTS
An adequate layer of good quality topsoil capable of supporting revegetation shall be placed over the entire
disturbed area of the OWTS installation. A mixture of native grass seed that has good soil stabilizing
characteristics (but without taproots), provides a maximum transpiration rate, and competes well with
successional species. No trees or shrubs, or any vegetation requiring regular irrigation shall be placed over
the STA. Until vegetation is reestablished, erosion and sediment control measures shall be implemented and
maintained on site. The owner of the OWTS shall be responsible for maintaining proper vegetation cover.
OPERATION INFORMATION AND MAINTENANCE
The property owner shall be responsible for the operation and maintenance of each OWTS servicing the
property. The property owner is responsible for maintaining service contracts for manufactured units,
alternating STAs, and any other components needing maintenance.
Geo-fabrics or plastics should not be used over the STA. No heavy equipment, machinery, or materials should
be placed on the backfilled STA. Machines with tracks (not wheels) should be used during construction of the
STA for better weight distribution. Livestock should not graze on the STA. Plumbing fixtures should be checked
to ensure that no additional water is being discharged to OWTS. For example, a running toilet or leaky faucet
can discharge hundreds of gallons of water a day and harm a STA.
If an effluent filter or screen has been installed in the OWTS, we recommend this filter or screen be cleaned
annually, or as needed. If the OWTS consists of a pressurized pump system, we recommend the laterals be
flushed annually, or as needed.
The homeowner should pump the septic tank every two years, or as needed gauged by measurement of solids
in the tank. Garbage disposal use should be minimized, and non-biodegradable materials should not be placed
into the OWTS. Grease should not be placed in household drains. Loading from a water softener should not
be discharged into the OWTS. No hazardous wastes should be directed into the OWTS. Mechanical room
drains should not discharge into the OWTS. The OWTS is engineered for domestic waste only.
ADDITIONAL CONSTRUCTION NOTES If design includes a pump, weep holes must be installed to allow pump lines to drain to minimize risk of
freezing. The pump shall have an audible and visual alarm notification in the event of excessively high-
water conditions and shall be connected to a control breaker separate from the high-water alarm breaker
and from any other control system circuits. The pump system shall have a switch so the pump can be
manually operated.
Excavation equipment must not drive in the excavation of the STA due to the potential to compact soil.
Extensions should be placed on all septic tank components to allow access to them from existing grade.
Backfill over the STA must be uniform and granular with no material greater than minus 3-inch.
LIMITS: The design is based on information submitted. If soil conditions encountered are different from conditions
described in report, CBO Inc. should be notified. All OWTS construction must be according to the county
regulations. Requirements not specified in this report must follow applicable county regulations. The
contractor should have documented and demonstrated knowledge of the requirements and regulations of
the county in which they are working. Licensing of Systems Contractors may be required by county
regulation.
Page 7
Please call with questions.
Sincerely,
CBO Inc.
Carla Ostberg, MPH, REHS
Pump Selection for a Pressurized System - Single Family Residence Project
1319 CR 127
Parameters
Discharge Assembly Size
Transport Length Before Valve
Transport Pipe Class
Transport Line Size
Distributing Valve Model
Transport Length After Valve
Transport Pipe Class
Transport Pipe Size
Max Elevation Lift
Manifold Length
Manifold Pipe Class
Manifold Pipe Size
Number of Laterals per Cell
Lateral Length
Lateral Pipe Class
Lateral Pipe Size
Orifice Size
Orifice Spacing
Residual Head
Flow Meter
'Add-on' Friction Losses
1.25
50
40
1.50
6402
5
40
1.50
3
20
40
1.25
4
25
40
1.25
5/32
2
5
None
0
inches
feet
inches
feet
inches
feet
feet
inches
feet
inches
inches
feet
feet
inches
feet
Calculations
Minimum Flow Rate per Orifice
Number of Orifices per Zone
Total Flow Rate per Zone
Number of Laterals per Zone
% Flow Differential 1st/Last Orifice
Transport Velocity Before Valve
Transport Velocity After Valve
0.68
26
17.6
2
0.9
2.8
2.8
gpm
gpm
%
fps
fps
Frictional Head Losses
Loss through Discharge
Loss in Transport Before Valve
Loss through Valve
Loss in Transport after Valve
Loss in Manifold
Loss in Laterals
Loss through Flowmeter
'Add-on' Friction Losses
2.2
0.9
3.7
0.1
0.2
0.1
0.0
0.0
feet
feet
feet
feet
feet
feet
feet
feet
Pipe Volumes
Vol of Transport Line Before Valve
Vol of Transport Line After Valve
Vol of Manifold
Vol of Laterals per Zone
Total Vol Before Valve
Total Vol After Valve
5.3
0.5
1.6
3.9
5.3
5.9
gals
gals
gals
gals
gals
gals
Minimum Pump Requirements
Design Flow Rate
Total Dynamic Head
17.6
15.3
gpm
feet
0 5 10 15 20 25 30 35 400
50
100
150
200
250
300
Net Discharge (gpm)
PumpData
PF3005 High Head Effluent Pump
30 GPM, 1/2HP
115/230V 1Ø 60Hz, 200V 3Ø 60Hz
PF3007 High Head Effluent Pump
30 GPM, 3/4HP
230V 1Ø 60Hz, 200/460V 3Ø 60Hz
PF3010 High Head Effluent Pump
30 GPM, 1HP
230V 1Ø 60Hz, 200/460V 3Ø 60Hz
PF3015 High Head Effluent Pump
30 GPM, 1-1/2HP
230V 1Ø 60Hz, 200/230/460V 3Ø 60Hz
Legend
System Curve:
Pump Curve:
Pump Optimal Range:
Operating Point:
Design Point:
5020 County Road 154
Glenwood Springs, CO 81601
phone: (970) 945-7988
fax: (970) 945-8454
email: kaglenwood@kumarusa.com
www.kumarusa.com Office Locations: Denver (HQ), Parker, Colorado Springs, Fort Collins, Glenwood Springs, and Summit County, Colorado
SUBSOIL STUDY
FOR FOUNDATION DESIGN
PROPOSED RESIDENCE
1319 COUNTY ROAD 127 (MOUNTAIN SPRINGS ROAD)
GARFIELD COUNTY, COLORADO
PROJECT NO. 21-7-112
FEBRUARY 5, 2021
PREPARED FOR:
LINDSAY GURLEY
1319 COUNTY ROAD 127
GLENWOOD SPRINGS, COLORADO 81601
lindsay@lindsaygurley.com
Kumar & Associates, Inc. ® Project No. 21-7-112
TABLE OF CONTENTS
PURPOSE AND SCOPE OF STUDY ....................................................................................... - 1 -
PROPOSED CONSTRUCTION ................................................................................................ - 1 -
SITE CONDITIONS ................................................................................................................... - 1 -
PROJECT SITE GEOLOGY ...................................................................................................... - 2 -
FIELD EXPLORATION ............................................................................................................ - 2 -
SUBSURFACE CONDITIONS ................................................................................................. - 2 -
FOUNDATION BEARING CONDITIONS .............................................................................. - 3 -
DESIGN RECOMMENDATIONS ............................................................................................ - 3 -
FOUNDATIONS .................................................................................................................... - 3 -
FOUNDATION AND RETAINING WALLS ....................................................................... - 4 -
FLOOR SLABS ...................................................................................................................... - 5 -
UNDERDRAIN SYSTEM ..................................................................................................... - 6 -
SITE GRADING ..................................................................................................................... - 6 -
SURFACE DRAINAGE ......................................................................................................... - 7 -
LIMITATIONS ........................................................................................................................... - 7 -
FIGURE 1 - LOCATION OF EXPLORATORY BORING
FIGURE 2 – LOG OF EXPLORATORY BORING
FIGURE 3 - SWELL-CONSOLIDATION TEST RESULTS
FIGURE 4 - GRADATION TEST RESULTS
TABLE 1- SUMMARY OF LABORATORY TEST RESULTS
Kumar & Associates, Inc. ® Project No. 21-7-112
PURPOSE AND SCOPE OF STUDY
This report presents the results of a subsoil study for a proposed residence to be located at
1319 County Road 127 (Mountain Springs Road), Garfield County, Colorado. The project site is
shown on Figure 1. The purpose of the study was to develop recommendations for the
foundation design. The study was conducted in accordance with our agreement for geotechnical
engineering services to Lindsay Gurley dated January 7, 2021.
A field exploration program consisting of an exploratory boring was conducted to obtain
information on the subsurface conditions. Samples of the subsoils and bedrock obtained during
the field exploration were tested in the laboratory to determine their classification,
compressibility or swell and other engineering characteristics. The results of the field
exploration and laboratory testing were analyzed to develop recommendations for foundation
types, depths and allowable pressures for the proposed building foundation. This report
summarizes the data obtained during this study and presents our conclusions, design
recommendations and other geotechnical engineering considerations based on the proposed
construction and the subsurface conditions encountered.
PROPOSED CONSTRUCTION
The existing residence will be removed and the new residence built in its place. The proposed
residence will be a one or two story structure with an attached garage. Ground floor will be slab-
on-grade or structural over crawlspace. Grading for the structure is assumed to be relatively
minor with cut depths between about 3 to 6 feet. We assume relatively light foundation loadings,
typical of the proposed type of construction.
When building location, grading and loading information have been developed, we should be
notified to re-evaluate the recommendations presented in this report.
SITE CONDITIONS
There is an existing one-story modular residence on the subject site. The site is accessed by an
existing gravel driveway from the southwest. Topography at the site consists of valley side with
moderate to steep slopes down to the southeast. There is about 6 feet of elevation difference
across the proposed building area. The site has undergone cut and fill grading for the existing
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Kumar & Associates, Inc. ® Project No. 21-7-112
development including possible fill in the lower part of the building site. Vegetation at the site
consists of native grass and weeds, mature scrub oak, and scattered conifers.
PROJECT SITE GEOLOGY
The project site is underlain by the Permian and Pennsylvanian-age Maroon Formation. The
Maroon Formation is a fine to coarse grained sandstone with interbedded claystone and
conglomerate. The bedding dip of the Maroon Formation in the area of the subject site is about
50 degrees down to the southwest. A thin layer of colluvial soil overlies the Maroon Formation
at the subject site in some areas.
FIELD EXPLORATION
The field exploration for the project was conducted on January 27, 2021. One exploratory
boring was drilled at the location shown on Figure 1 to evaluate the subsurface conditions. The
boring was advanced with 4 inch diameter continuous flight augers powered by a truck-mounted
CME-45B drill rig. The boring was logged by a representative of Kumar & Associates, Inc.
Samples of the subsoils were taken with 1⅜ inch and 2 inch I.D. spoon samplers. The samplers
were driven into the subsurface materials at various depths with blows from a 140 pound
hammer falling 30 inches. This test is similar to the standard penetration test described by
ASTM Method D-1586. The penetration resistance values are an indication of the relative
density or consistency of the subsoils and hardness of the bedrock. Depths at which the samples
were taken and the penetration resistance values are shown on the Log of Exploratory Boring,
Figure 2. The samples were returned to our laboratory for review by the project engineer and
testing.
SUBSURFACE CONDITIONS
A graphic log of the subsurface conditions encountered at the site is shown on Figure 2. The
subsoils consist of about ½ foot of road base overlying about 2½ feet of previously placed fill
material consisting of sandy clay with scattered gravel underlain by about 3 feet of dense, silty
clayey gravel and sand. Very hard sandstone bedrock of the Maroon Formation was encountered
at a depth of 6 feet down to the maximum depth explored of 16½ feet. Drilling in the bedrock
with auger equipment was difficult due to the hardness and drilling refusal was encountered in
the deposit at a depth of 16½ feet.
- 3 -
Kumar & Associates, Inc. ® Project No. 21-7-112
Laboratory testing performed on samples obtained from the boring included natural moisture
content and density and gradation analyses. Results of swell-consolidation testing performed on
a relatively undisturbed drive sample of the colluvial soils, presented on Figure 3, indicate low
compressibility under conditions of loading and wetting and a minor expansion potential when
wetted under a 1,000 psf surcharge. Results of gradation analyses performed on a small diameter
drive sample (minus ¾-inch fraction) of the granular fill soils are shown on Figure 4. The
laboratory testing is summarized in Table 1.
No free water was encountered in the boring at the time of drilling and the subsoils were slightly
moist.
FOUNDATION BEARING CONDITIONS
At assumed excavation depths, we expect the subgrade will vary from the silty clayey gravel and
sand soils to bedrock of the Maroon Formation. The silty clayey gravel and sand soils possess
moderate bearing capacity and low settlement potential. The expansion potential shown in the
swell-consolidation test performed on a sample of the gravel and sand is likely an anomaly and
does not warrant mitigation. The bedrock of the Maroon Formation possesses moderate to high
bearing capacity and low settlement potential.
Spread footings appear feasible for foundation support of the residence with a minor risk of
differential settlement. The risk of settlement is due to the variable bearing conditions from
assumed soil to rock. A lower risk alternative would be to bear the footings entirely on the
bedrock of the Maroon Formation or on compacted structural fill extended down to the bedrock.
The compacted structural fill can consist of the on-site natural soils devoid of vegetation, topsoil,
and oversized rock (plus 6-inch size). Existing fill and disturbed soils from previous
development should be removed from below the building area.
DESIGN RECOMMENDATIONS
FOUNDATIONS
Considering the subsurface conditions encountered in the exploratory boring and the nature of
the proposed construction, we recommend the building be founded with spread footings bearing
on the natural granular soils or bedrock.
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Kumar & Associates, Inc. ® Project No. 21-7-112
The design and construction criteria presented below should be observed for a spread footing
foundation system.
1) Footings placed on the undisturbed natural granular soils or bedrock should be
designed for an allowable bearing pressure of 2,500 psf. Based on experience, we
expect settlement of footings designed and constructed as discussed in this section
will be about 1 inch or less.
2) The footings should have a minimum width of 16 inches for continuous walls and
2 feet for isolated pads.
3) Exterior footings and footings beneath unheated areas should be provided with
adequate soil cover above their bearing elevation for frost protection. Placement
of foundations at least 36 inches below exterior grade is typically used in this
area.
4) Continuous foundation walls should be reinforced top and bottom to span local
anomalies such as by assuming an unsupported length of at least 12 feet.
Foundation walls acting as retaining structures should also be designed to resist
lateral earth pressures as discussed in the "Foundation and Retaining Walls"
section of this report.
5) All existing fill, debris, topsoil and any loose or disturbed soils should be
removed and the footing bearing level extended down to the relatively dense
natural granular soils or hard bedrock. The exposed soils in footing area should
then be moistened and compacted.
6) A representative of the geotechnical engineer should observe all footing
excavations prior to concrete placement to evaluate bearing conditions.
FOUNDATION AND RETAINING WALLS
Foundation walls and retaining structures which are laterally supported and can be expected to
undergo only a slight amount of deflection should be designed for a lateral earth pressure
computed on the basis of an equivalent fluid unit weight of at least 50 pcf for backfill consisting
of the on-site soils and well broken bedrock and at least 45 pcf for backfill consisting of
imported granular materials. Cantilevered retaining structures which are separate from the
residence and can be expected to deflect sufficiently to mobilize the full active earth pressure
condition should be designed for a lateral earth pressure computed on the basis of an equivalent
fluid unit weight of at least 45 pcf for backfill consisting of the on-site soils and well broken
bedrock and at least 40 pcf for backfill consisting of imported granular materials.
- 5 -
Kumar & Associates, Inc. ® Project No. 21-7-112
All foundation and retaining structures should be designed for appropriate hydrostatic and
surcharge pressures such as adjacent footings, traffic, construction materials and equipment. The
pressures recommended above assume drained conditions behind the walls and a horizontal
backfill surface. The buildup of water behind a wall or an upward sloping backfill surface will
increase the lateral pressure imposed on a foundation wall or retaining structure. An underdrain
should be provided to prevent hydrostatic pressure buildup behind walls.
Backfill should be placed in uniform lifts and compacted to at least 90% of the maximum
standard Proctor density at a moisture content near optimum. Backfill placed in pavement and
walkway areas should be compacted to at least 95% of the maximum standard Proctor density.
Care should be taken not to overcompact the backfill or use large equipment near the wall, since
this could cause excessive lateral pressure on the wall. Some settlement of deep foundation wall
backfill should be expected, even if the material is placed correctly, and could result in distress to
facilities constructed on the backfill.
The lateral resistance of foundation or retaining wall footings will be a combination of the
sliding resistance of the footing on the foundation materials and passive earth pressure against
the side of the footing. Resistance to sliding at the bottoms of the footings can be calculated
based on a coefficient of friction of 0.45. Passive pressure of compacted backfill against the
sides of the footings can be calculated using an equivalent fluid unit weight of 375 pcf. The
coefficient of friction and passive pressure values recommended above assume ultimate soil
strength. Suitable factors of safety should be included in the design to limit the strain which will
occur at the ultimate strength, particularly in the case of passive resistance. Fill placed against
the sides of the footings to resist lateral loads should be compacted to at least 95% of the
maximum standard Proctor density at a moisture content near optimum.
FLOOR SLABS
The natural on-site soils, exclusive of topsoil, are suitable to support lightly loaded slab-on-grade
construction. To reduce the effects of some differential movement, floor slabs should be
separated from all bearing walls and columns with expansion joints which allow unrestrained
vertical movement. Floor slab control joints should be used to reduce damage due to shrinkage
cracking. The requirements for joint spacing and slab reinforcement should be established by the
designer based on experience and the intended slab use. A minimum 4 inch layer of free-
draining gravel should be placed beneath basement level slabs to facilitate drainage. This
- 6 -
Kumar & Associates, Inc. ® Project No. 21-7-112
material should consist of minus 2-inch aggregate with at least 50% retained on the No. 4 sieve
and less than 2% passing the No. 200 sieve.
All fill materials for support of floor slabs should be compacted to at least 95% of maximum
standard Proctor density at a moisture content near optimum. Required fill can consist of the on-
site natural granular soils devoid of vegetation, topsoil and oversized rock.
UNDERDRAIN SYSTEM
Although free water was not encountered during our exploration, it has been our experience in
the area and where bedrock is shallow that local perched groundwater can develop during times
of heavy precipitation or seasonal runoff. Frozen ground during spring runoff can create a
perched condition. We recommend below-grade construction, such as retaining walls,
crawlspace and basement areas, be protected from wetting and hydrostatic pressure buildup by
an underdrain system.
The drains should consist of rigid perforated PVC drainpipe placed in the bottom of the wall
backfill surrounded above the invert level with free-draining granular material. The drain should
be placed at each level of excavation and at least 1 foot below lowest adjacent finish grade and
sloped at a minimum ½% to a suitable gravity outlet. Free-draining granular material used in the
underdrain system should contain less than 2% passing the No. 200 sieve, less than 50% passing
the No. 4 sieve and have a maximum size of 2 inches. The drain gravel backfill should be at
least 1½ feet deep and covered with filter fabric such as Mirafi 140N or 160N.
SITE GRADING
The risk of construction-induced slope instability at the site appears low provided the building is
located in the existing graded pad area as planned and cut and fill depths are limited. We assume
the cut depths for the lower foundation level will not exceed about 2 feet. Fills should be limited
to about 8 feet deep, especially at the downhill side of the residence where the slope steepens.
Embankment fills should be compacted to at least 95% of the maximum standard Proctor density
near optimum moisture content. Prior to fill placement, the subgrade should be carefully
prepared by removing all vegetation and topsoil and compacting to at least 95% of the maximum
standard Proctor density. The fill should be benched into the portions of the hillside exceeding
20% grade.
- 7 -
Kumar & Associates, Inc. ® Project No. 21-7-112
Permanent unretained cut and fill slopes should be graded at 2 horizontal to 1 vertical or flatter
and protected against erosion by revegetation or other means. This office should review site
grading plans for the project prior to construction.
SURFACE DRAINAGE
The following drainage precautions should be observed during construction and maintained at all
times after the residence has been completed:
1) Inundation of the foundation excavations and underslab areas should be avoided
during construction.
2) Exterior backfill should be adjusted to near optimum moisture and compacted to
at least 95% of the maximum standard Proctor density in pavement and slab areas
and to at least 90% of the maximum standard Proctor density in landscape areas.
3) The ground surface surrounding the exterior of the building should be sloped to
drain away from the foundation in all directions. We recommend a minimum
slope of 12 inches in the first 10 feet in unpaved areas and a minimum slope of
3 inches in the first 10 feet in paved areas. Free-draining wall backfill should be
covered with filter fabric and capped with about 2 feet of the on-site finer graded
soils to reduce surface water infiltration.
4) Roof downspouts and drains should discharge well beyond the limits of all
backfill.
5) Landscaping which requires regular heavy irrigation should be located at least 5
feet from foundation walls.
LIMITATIONS
This study has been conducted in accordance with generally accepted geotechnical engineering
principles and practices in this area at this time. We make no warranty either express or implied.
The conclusions and recommendations submitted in this report are based upon the data obtained
from the exploratory boring drilled at the location indicated on Figure 1, the proposed type of
construction and our experience in the area. Our services do not include determining the
presence, prevention or possibility of mold or other biological contaminants (MOBC) developing
in the future. If the client is concerned about MOBC, then a professional in this special field of
practice should be consulted. Our findings include interpolation and extrapolation of the
subsurface conditions identified at the exploratory boring and variations in the subsurface
Kumar & Associates
Kumar & Associates
Kumar & Associates
Kumar & Associates
TABLE 1
SUMMARY OF LABORATORY TEST RESULTS
Project No. 21-7-112
SAMPLE LOCATION NATURAL MOISTURE CONTENT
NATURAL DRY DENSITY
GRADATION
PERCENT
PASSING NO. 200 SIEVE
ATTERBERG LIMITS UNCONFINED COMPRESSIVE STRENGTH SOIL TYPE BORING DEPTH GRAVEL SAND LIQUID LIMIT PLASTIC INDEX (%) (%)
(ft) (%) (pcf) (%) (%) (psf)
1 1 7.1 3 45 52 32 16 Very Sandy Clay with
Scattered Gravel (Fill)
4 4.8 119 35 Silty Clayey Gravel and
Sand
y
GARFIELD COUNTY BUILDING AND SANITATION DEPARTMENT
109 8th Street Suite 303
Glenwood Springs, Colorado 81801
Phone (303) 945 -8212
This does not constitute
INDIVIDUAL SEWAGE DISPOSAL PERMIT NQ a building or use permit. 11
Owner Fb} xt Jones
System Location A parcel of land situated in the NW 1/4 and tJ )J2 T9I'. 1/4 Sec, 2R, T6S, RR941
Licensed Installer Ib11 HAIlat1
Conditional Construction approval is hereby g for a 000 gallon US E 2.6 ear 3
X 4,c ei. r ln y /f r ct P"
z4 1i (s =Septic Tank or _Aerated treatment unit.
C ¢ btired)teAbsorptionarea (or dispersal area) computed as follows:
Perc rate of one inch in J0 minutes requires a minimum of 9j,Gsq. ft. of absorption area per bedroom.
3 ` /SThereforetheno. of bedrooms _x sq.ft . minimum requirement = a total of 4/..Lq. ft. of absorption area.
May we suggest
7 , .o .r r, .
i
F
DDU le ii ie ?'b lea Home /
3 !/ % ` ; E!l C fec 2.0 f /Uc < % if7 l c r /k /Nb cF/ r4
Date x 3k79 C e e c) (- 7 Inspector '? 3 v r-/ c `
9 79.
FINAL APPROVAVOF SYSTEM:1. % 1 + !
No system shall be deemed to be in compliance with the Sewage Disposal Laws until the assembled system is approved prior to cover•
ing any party'
Septic Tank access for inspection and cleaning within 12" of ground surface or aerated access ports above groundsurface.
IPropermaterialsandassembly. .Th /GR.r- f 7 c 1i
Co0?a2,r1 Trade name of septic tank or aerated treatment unit. /tin / 0 q,1 •
airAdequateabsorption (or dispersal) area. 2 (o 2N9 4 6.1 o - 4rr gad = 4D(
Adequate compliance with permit requirements.
y f•4 Adequate compliance with County and State regulations /requirements.
Other
Date_ ., /C — 5'^ O ` f _Inspector SLu. -2MD
RETAIN WITH RECEIPT RECORDS AT CONSTRUCTION SITE
CONDITIONS:
1. All Installation must comply with all requirements of the Colorado State Board of Health Individual Sewage Disposal SystemsChapter25, Article 10 C.R.S. 1973, Revised 1984.
2. This permit is valid only for connection to structures which have fully complied with County zoning and building
requirements. Connection to or use with any dwelling or structures not approved by the Building and Zoning office shall
automatically be a violation of a requirement of the permit and cause for both legal action and revocation of the permit.
3. Any person who constructs, alters, or installs an Individual sewage disposal system in a manner which involves a knowing
and material variation from the terms or specifications contained in the application of permit commits a Class I, Petty Offense500.00 fine — 6 months in Jail or both.).
Applicant: Green Copy Department: Pink Copy
Application
INDIVIDUAL SEWAGE DISPOS:L SYSTEM APPLICATION Approval by
OWNER 46;g76 orc%S County Official:
ADDRESS Sa Ao l0 6405 do/ PHONE 9 7nec
CONTRACTOR MO/
ADDRESS OC 4 2 c ,<± C&.s 6WcVPHoNE 9W/S- 6e 3( /PERMIT REQUEST FOR: b} New Installation Alteration RepairAttachseparatesheetsorreportshowingentireareawithrespecttosurrounding areas,topography of area, habitable building, location of potable water wells, soil percolationtestholes, soil profiles in test holes. See page 4.)
LOCATION OF PROPOSED FACILITY: County 6 c66'ZD
Near what City of Town C5keduideu9 S //t /,t/65 Lot Size 3S.00 /96W
Legal Description /9 %ice. F /ay.d TIare:4 iv Tie l/Gt/J Ae/D 4/t4a <Sec. t, 00.s, 2.19 Wofrme eve
WASTES TYPE:54 Dwelling Transient Use
Commercial or Institutional Non- domestic Wastes
Other - Describe
BUILDING OR SERVICE TYPE: A.Ade& G. / /de /1/00 /L4
Number of bedrooms 3 Number of persons 2
Garbage grinder NO Automatic washer Dishwasher
SOURCE AND TYPE OF WATER SUPPLY: well spring stream or creek
Give depth of all wells within 180 feet of system:49
If supplied by community water, give name or supplier: 806 Scq.e,e00J 4'r e / ,NL - * -
GROUND CONDITIONS:
Depth to bedrock:
Depth to first Ground Water Table:
Percent ground slope:
DISTANCE TO NEAREST COMMUNITY SEWER SYSTEM:
Was an effort made to connect to community system?
TYPE OF INDIVIDUAL SEWAGE DISPOSAL SYSTEM PROPOSED:
C) Septic Tank Aeration Plant Vault
Vault Privy Composting Toilet Recycling, potable use
Pit Privy Incineration Toilet Recycling, other use
Chemical Toilet Other - Describe:
FINAL DISPOSAL BY:
t .,) Absorption Trench, Bed or Pit Evapotranspiration
Underground Dispersal Sand Filter
Above Ground Dispersal Wastewater Pond
Other - Describe:
WILL EFFLUENT BE DISCHARGED DIRECTLY INTO WATERS OF THE STATE? 10
J
Page 2
SOIL PERCOLATION TEST RESULTS: To be completed by Registered Professional Engineer.)
Minutes per inch in hole No. 1 MinutesAr per inch in hole No. 3
Minutes per inch in hole No. 2 Minutes per inch in hole No.
Name, address and telephone of RPE who made soil absorption tests:
Name, address and telephone of RPE responsible for design of the system:
Applicant acknowledges that the completeness of the application is conditional upon suchfurthermandatoryandadditionaltestsandreportsasmayberequiredbythelocalhealthdepartmenttobemadeandfurnishedbytheapplicantorbythelocalhealthdepartmentfor
purposes of the evaluation of the application; and the issuance of the permit iS subject tosuchtermsandconditionsasdeemednecessarytoinsurecompliancewithrulesandregulationsadoptedunderArticle10, Title 25, C.R.S. 1973, as amended. The undersigned hereby certifiesthatallstatementsmade, information and reports submitted herewith and required to besubmittedbytheapplicantareorwillberepresentedtobetrueandcorrecttothebest
of my knowledge and belief and are designed to be relied on by the local department of healthinevaluatingthesameforpurposesofissuingthepermitappliedforherein. I further under-
stand that any falsification or misrepresentation may result in the denial of the application
or revocation of any permit granted based upon said application and in legal action for per-jury as provided by law.
Date Signed 0010
PLEASE DRAW AND ACCURATE MAPTO YOUR PROPERTY
5-c 977
Page 3
PLOT PLAN AND DESIGN FEATURES:
Include by measured distance location of wells, springs, potable water supplylines, cisterns, buildings, property lines, subsoil drains, lake, water course,stream, dry gulch and show location of proposed system by direction and distancefromdwellingorotherfixedreferenceobject, and additional submissions in
support of this application such as data, plans, specifications, statements andcommitments.
JET 17T4C//4 5 - 44 /54.77 -
Page 4
1319 CR 127 Legend
1319 Co Rd 127
100 ft
N
➤➤
N
NORTH 1/4 CORNER
SECTION 28
SITE BENCH MARK
FOUND REBAR & 1-1/4"
YELLOW PLASTIC CAP LS19598
ELEVATION:6200.22
OWNER
SAMUEL R. FEUERBORN & LINDSAY JO. GURLEY
PARCEL NO. 218578200024
RECEPTION NO. 909988
1319 COUNTY ROAD 127
GLENWOOD SPRINGS
10"/28'
7"/12'
6"/12'
6"/12'
6"/12'
8"/32'
7"/20'
7"/20'8"/16'6"/12'
12"/24'
7"/16'
6"/12'
6"/20'
7"/16'
7"/12'
7"/16'
6"/12'
6"/12'
8"/28'
E
INV6266.64
INV
6268.04
INV6270.02
INV6262.25
27.0'
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50' WIDE EASEMENT
RECEPTION NO. 264393
PRO
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EASEMENTRECEPTION NO. 264393
25'
F
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ROAD
10"/28'
7"/12'
6"/12'
6"/12'
6"/12'
8"/32'
7"/20'
7"/20'
8"/16'6"/12'
12"/24'
7"/16'
6"/12'
6"/20'
7"/16'
7"/12'
7"/16'
6"/12'
6"/12'
8"/28'
E
INV
6266.64
INV
6268.04
INV
6270.02
INV
6262.25
27.0'
8.0'
8.
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52
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3
'
52
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627
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EASEMENT
RECEPTION NO. 264393
2
5
'
F
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SURVEYOR 'S STATEMENT
I, RODNEY P. KISER, DO HEREBY STATE THAT THIS EXISTING CONDITIONS & TOPOGRAPHIC SURVEY WAS PREPARED
BY TRUE NORTH COLORADO, LLC. FOR SAMUEL FEUERBORN & LINDSAY JO GURLEY, THAT SAID SURVEY WAS
PREPARED BY ME OR UNDER MY SUPERVISION AND RESPONSIBLE CHARGE AND THAT IT IS TRUE AND CORRECT
TO THE BEST OF MY BELIEF AND KNOWLEDGE.
POWER POLE
DECIDUOUS TREE
GAS SERVICE
OVERHEAD ELECTRIC LINE
SEPTIC LID
LEGEND
NOTES:
4.THIS PROPERTY IS SUBJECT TO RESERVATIONS, RESTRICTIONS, COVENANTS AND EASEMENTS OF RECORD OR IN
PLACE.
5.THIS SURVEY WAS PREPARED WITHOUT THE BENEFIT OF A TITLE COMMITMENT, THEREFORE, ANY EXCEPTIONS TO
TITLE THAT MAY AFFECT THE SUBJECT PROPERTY HAVE NOT BEEN REVIEWED BY TRUE NORTH COLORADO, LLC.
6.ELEVATIONS SHOWN HEREON ARE BASED ON GPS OBSERVATIONS UTILIZING THE CONTINUOUS OPERATING
REFERENCE STATIONS (CORS) THROUGH THE MESA COUNTY RTVRN NETWORK BROAD CASTING NORTH
AMERICAN VERTICAL DATUM (NAVD88) YIELDING AN ON-SITE BENCHMARK ELEVATION OF 6200.22.
7.CONTOUR INTERVAL EQUALS ONE FOOT.
A PARCEL OF LAND SITUATED IN THE NW1/4 AND W1/2NE1/4 SECTION 28
TOWNSHIP 6 SOUTH, RANGE 89 WEST OF THE 6TH PM
COUNTY OF GARFIELD, STATE OF COLORADO
EXISTING CONDITIONS & TOPOGRAPHIC SURVEY
TRUE NORTH COLORADO LLC.
A LAND SURVEYING AND MAPPING COMPANY
P.O. BOX 614 - 386 MAIN STREET UNIT 3
NEW CASTLE, COLORADO 81647
(970) 984-0474
www.truenorthcolorado.com
PROJECT NO: 2020-436
DATE:December 21, 2020
DRAWN
RPK
SURVEYED
GBL
SHEET
1 OF 1
TRUENORTH
A LAND SURVEYING AND MAPPING COMPANY
15'7.5'30'
SCALE: 1" = 15'
N
0
NOTICE: ACCORDING TO COLORADO LAW YOU MUST COMMENCE ANY
LEGAL ACTION BASED UPON ANY DEFECT IN THIS SURVEY WITHIN THREE
YEARS AFTER YOU FIRST DISCOVER SUCH DEFECT. IN NO EVENT MAY ANY
ACTION BASED UPON ANY DEFECT IN THIS SURVEY BE COMMENCED MORE
THAN TEN YEARS FROM THE DATE OF CERTIFICATION SHOWN HEREON.
PROPANE TANK
150'75'300'
SCALE: 1" = 150'
N
0
SE
E
D
E
T
A
I
L
CONIFEROUS TREE
6"/12'TREE DIAMETER & DRIP LINE SIZE
ZONING
Gar eld County, CO
Developed by
Account
Number
R080771
Parcel
Number
218528200024
Acres 35
Land SqFt 0
Tax Area 008
2019 Mill
Levy
73.2960
Physical
Address
1319 127 COUNTY RD
GLENWOOD SPRINGS 81601
Owner
Address
FEUERBORN, SAMUEL R & GURLEY,
LINDSAY JO
1319 COUNTY ROAD 127
GLENWOOD SPRINGS CO 81601
2019 Total Actual
Value
$455,190 Last 2 Sales
Date Price
7/31/2018 $255,200
9/19/2014 $117,500
Date created: 6/5/2024
Last Data Uploaded: 6/5/2024 2:09:53 PM
921 ft
Overview
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