HomeMy WebLinkAbout2450 Alkali Creek Rd - 185520400091Environmental Health
Department
P.O. Box 179
500 Broadway
Eagle, CO 81631-0179
Phone: (970) 328-8730
Fax: (970) 328-7185
Permit
Permit No. OWTS-018399-2020
Permit Type: OWTS Permit
Work Classification: New
Permit Status: Active
Issue Date: 4/6/2020 Expires: 8/4/2020
On-Site Wastewater
Treatement System
Project Address Parcel Number
, 185520400091
Owner Information Address
Joshua Boe PO Box 1883
Avon, CO 81620
Phone:
Cell: (970) 390-7351
Email: joshuadboe@yahoo.com
Inspections:
For Inspections Call: (970) 328-8755
and call the Design Engineer
Engineer Phone Email
KUMAR & ASSOCIATES, Dave Young (970) 945-7988 dyoung@kumarusa.com
Contractor License Number Phone Email
Reyes General Construction reyescarlossti@gmail.com(970) 376-5760
Permitted Construction / Details:
Install the OWTS exactly as shown in the H-P Kumar design dated December 5, 2018, stamped and signed by David
A. Young, PE. The system is designed to serve a four bedroom single family residence and a one bedroom
accessory dwelling unit, for a combined design flow based on five bedrooms.
The system consists of a 1,500 gallon (2,000 gallon total volume) three compartment Valley Precast septic tank with
an Orenco PF3005 high head effluent pump within a biotube vault in the third compartment. Set pump floats to
deliver 141 gallons of effluent approximately 30 feet to an Orenco V6404 automatic distribution valve (ADV), set level
at the high point of the system and made accessible at or above grade. The ADV will alternate doses of effluent
between four sets of trenches, for a total of eight shallow trenches, each consisting of twenty Standard Quick4 Plus
chambers, for a total of 160 chambers. Inspection ports must be installed at both ends of each trench, and flushing
assemblies/distribution line cleanouts (as shown in the design Figure 6) at the end of each distribution lateral.
Maintain all elevations and applicable setbacks, as shown on the design drawing.
Electrical permits must be obtained for the pump, audible and visual alarm system from the Eagle County Building
Department.
Contact Eagle County Environmental Health Department and the design engineer well in advance of requesting
inspections prior to backfilling any component of the OWTS. The design engineer is responsible for conducting all
inspections necessary to certify the installation and assure functionality of the system. System certification, along
with photos and a record drawing is required to be submitted to, and approved by, Eagle County Environmental
Health prior to the use of the system or occupancy of the dwelling.
THIS PERIMT EXPIRES BY TIME LIMITATION AND BECOMES NULL AND VOID IF THE WORK AUTHORIZED BY THE PERMIT IS NOT COMMENCED WITHIN 120 DAYS OF
ISSUANCE, OR BEFORE THE EXPIRATION OF AN ASSOCIATED BUILDING PERMIT
Issued by: Environmental Health Department, Eagle County, CO
Claire Lewandowski
Date
April 06, 2020
CONDITIONS
1.
2.ALL INSTALLATIONS MUST COMPLY WITH ALL REQUIREMENTS OF THE EAGLE COUNTY PUBLIC HEALTH AGENCY ON-SITE WASTEWATER TREATMENT SYSTEM
REGULATIONS ADOPTED PURSUANT TO AUTHORITY GRANTED IN CR.S. 25-10-101, et seq., AS AMENDED
3.THIS PERMIT IS VALID ONLY FOR PERFORMING WORK ON OWTS ASSOCIATED WITH STRUCTURES WHICH HAVE FULLY COMPLIED WITH COUNTY ZONING AND
BUILDING REQUIREMENTS CONNECTION TO, OR USE WITH, ANY DWELLING OR STRUCTURE NOT APPROVED BY THE ZONING AND BUILDING DEPARTMENTS
SHALL AUTOMATICALLY BE A VIOLATION OF A REQUIREMENT OF THE PERMIT AND WILL RESULT IN BOTH LEGAL ACTION AND REVOCATION OF THE PERMIT
4.1.6(A)(1) EAGLE COUNTY PUBLIC HEALTH AGENCY ON-SITE WASTEWATER TREATMENT SYSTEM REGULATIONS REQUIRES ANY PERSON WHO CONSTRUCTS,
ALTERS OR INSTALLS AN ON-SITE WASTEWATER TREATMENT SYSTEM TO BE LICENSED
Monday, April 6, 2020 1
***************************************************************************
APPLICATION FOR ON-SITE WASTEWATER TREATMENT SYSTEM (OWTS) PERMIT
INCOMPLETE APPLICATIONS MAY NOT BE ACCEPTED (SITE PLAN MUST BE INCLUDED)
FEE SCHEDULE
APPLICATION FEE FOR NEW OWTS OR MAJOR REPAIRS $800.00 MINOR REPAIR FEE $400.00
Fee includes the design review, permitting and maintenance of OWTS records
Make all checks payable to: Eagle County Treasurer
Property Owner: _______________________________________Phone: ________________________
Owner Mailing Address: ________________________________ email: _________________________
Professional Engineer: __________________________________ Phone: ________________________
Applicant / Contact Person: ______________________________Phone: ________________________
Licensed Systems Contractor Name / Company: ___________________________________________
Contractor Mailing Address: _________________________________ Contractor License #:_______
Contractor Phone Number: ________________________ email: ______________________________
OWTS Permit Application is for: ____ New Installation ____ Alteration ____ Repair
Tax Parcel Number: _________________________________ Lot Size: ________________________
Assessor’s Link: www.eaglecounty.us/patie/
Physical Address: _____________________________________________________________________
Legal Description: ____________________________________________________________________
Building Type: _____ Residential / Single Family
_____ Residential / Multi Family
_____ Commercial / Industrial
Number of Bedrooms: ______
Number of Bedrooms: ______
Type of Use: _______________
*As of 06/27/2014, all systems require design by a Registered Professional Engineer.
Type of Water Supply: ____ Private Well ____ Spring ____ Surface ____ Public
If Public, Name of Supplier: ____________________________________________________________
Applicant Signature: ______________________________________Date:_______________________
****************************************************************************
Office Use Only: OWTS PERMIT # __________________ BUILDING PERMIT # ____________________
Amount Paid: ___________ Receipt #: ___________ Check #: ___________ Date: ______________
DEPARTMENT OF
ENVIRONMENTAL HEALTH
(970) 328-8755
FAX: (970) 328-8788
TOLL FREE: 800-225-6136
www.eaglecounty.us
P.O. Box 179
500 Broadway
Eagle, CO 81631
environment@eaglecounty.us
INSPECTION WORKSHEET (INSP-512256-2022)
FOR EAGLE COUNTY GOVERNMENT
OWTS-018399-2020Case Number:Case Module:Permit Management
RequestedInspection Status:Inspection Date:
OWTS Final InspectionInspection Type:Inspector:
Job Address:Parcel Number:2450 Alkali Creek Rd
Wolcott Area, CO
185520400091
Company Name NameContact Type
Contractor Reyes General Construction Carlos Reyes
Engineer KUMAR & ASSOCIATES Dave Young
Owner Joshua Boe
CommentsPassedChecklist Item
True A Valley Precast 1,500 gallon, three chamber septic tank with an
Orenco PF3005 Effluent pump installed in the third chamber.
Septic Tank - Septic Tank
True Received 1/5/2022 from K&A.Record Drawing - Record Drawing
True Received 1/5/2022 from K&A.Record Photos - Record Photos
True Received 3/17/2020 from K&A.Site and Soil - Site & Soil
True Received 1/5/2022 from K&A.Final Certification Letter - Final Certification Letter
True Received 3/17/2020 from K&A.General Plan - General Plan
True STA consists of 8 rows of 20 Infiltrator Quick4 Plus Standard
chambers in each row.
Soil Treatment Area (STA) - Soil Treatment Area (STA)
True Reyes General Construction was the licensed installer.Identification of Systems Contractor - Identification of
Systems Contractor
January 05, 2022 Page 1 of 1P.O. Box 179, 500 Broadway, Eagle, CO 81631-0179
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
December 30, 2021
Joshua Boe
P. O. Box 1883
Avon, Colorado 81620
(joshuadboe@yahoo.com)
Project No. 18-7-376.02
Permit No. OWTS-018399-2020
Subject: Certification of Onsite Wastewater Treatment System, Proposed Residence,
Lot 7, Horse Mountain Estates, 2450 Alkali Creek Road, Eagle County, Colorado
Dear Joshua:
A representative of Kumar & Associates observed the installation of the Onsite Wastewater
Treatment System (OWTS) for the residence at the subject site as required by the Eagle County
Environmental Health Department. Our observations and recommendations are presented in this
report. The services are supplemental to Kumar & Associates agreement for professional
services to you dated May 23, 2018.
We previously designed the OWTS for the residence as submitted in our report dated December
5, 2018, Project No. 18-7-376.02. The system was designed for a total of five bedrooms and
nine persons. The system was installed by Reyes General Construction.
We performed our evaluation on April 28 and 29, 2020 and December 13, 2021. The OWTS
components observed included: control panel, cleanout, septic tank, pump, effluent line,
automatic distributing valve (ADV) and soil treatment area (STA) and the locations of these
components. The installation and locations of the system components were verified as shown on
Figure 1. Pictures of the OWTS components made during the site visit are included with this
report. The distance locations to the septic tank shown on Figure 1 were made by taping.
On December 13, 2021, after power had been supplied to the pump, a pump performance test
was performed with adequate pump performance observed.
The installation of the sewer line from the residence to the septic tank was not observed. No
photographs of the sewerline were able to be obtained from the installer.
It is our opinion that the OWTS was installed in general conformance with the above referenced
design.
The observations and recommendations presented above are based on our site observations and
our experience in the area. We make no warranty either express or implied. Alterations to the
Kumar & Associates
OWTS PHOTOGRAPH LOG
PROPOSED RESIDENCE
LOT 7, HORSE MOUNTAIN ESTATES
ALKALI CREEK ROAD
EAGLE COUNTY, COLORADO
Project No. 18-7-376.02
Photograph 1: Cleanout and
control panel.
Photograph 2: Valley Precast
1,500+500 gallon, three-chamber
septic tank.
OWTS PHOTOGRAPH LOG
PROPOSED RESIDENCE
LOT 7, HORSE MOUNTAIN ESTATES
ALKALI CREEK ROAD
EAGLE COUNTY, COLORADO
Project No. 18-7-376.02
Photograph 3: Orenco PF3005
with Biotube Vault installed in
third chamber of septic tank.
Photograph 4: Orenco V6404
Automatic Distributing Valve
(ADV)
OWTS PHOTOGRAPH LOG
PROPOSED RESIDENCE
LOT 7, HORSE MOUNTAIN ESTATES
ALKALI CREEK ROAD
EAGLE COUNTY, COLORADO
Project No. 18-7-376.02
Photograph 5: Effluent line
exiting septic tank to ADV and
to soil treatment area (STA).
Photograph 6: Effluent lines to
STA.
OWTS PHOTOGRAPH LOG
PROPOSED RESIDENCE
LOT 7, HORSE MOUNTAIN ESTATES
ALKALI CREEK ROAD
EAGLE COUNTY, COLORADO
Project No. 18-7-376.02
Photograph 7: Cleanout
installed at end of STA trench.
Observation ports not yet
installed.
Photograph 8: Control Panel.
5020 County Road 154
Glenwood Springs, CO 81601
Phone: (970) 945-7988
Fax: (970) 945-8454
Email: hpkglenwood@kumarusa.com
Office Locations: Parker, Glenwood Springs, and Silverthorne, Colorado
ONSITE WASTEWATER TREATMENT SYSTEM DESIGN
PROPOSED RESIDENCE
LOT 7, HORSE MOUNTAIN ESTATES
ALKALI CREEK ROAD
EAGLE COUNTY, COLORADO
PROJECT NO. 18-7-376.02
DECEMBER 5, 2018
PREPARED FOR:
JOSHUA BOE
P. O. BOX 1883
AVON, COLORADO 81620
joshuadboe@yahoo.com
Project No. 18-7-376.02
TABLE OF CONTENTS
INTRODUCTION ........................................................................................................... - 1 -
BACKGROUND INFORMATION ................................................................................ - 1 -
PROPOSED CONSTRUCTION ..................................................................................... - 1 -
SITE CONDITIONS ....................................................................................................... - 1 -
SUBSURFACE CONDITIONS ...................................................................................... - 2 -
OWTS ANALYSIS ......................................................................................................... - 3 -
DESIGN RECOMMENDATIONS ................................................................................. - 4 -
SOIL TREATMENT AREA ....................................................................................... - 4 -
OWTS COMPONENTS .............................................................................................. - 5 -
OWTS OPERATION AND MAINTENANCE .............................................................. - 8 -
OWTS HOUSEHOLD OPERATION ......................................................................... - 9 -
OWTS MAINTENANCE ........................................................................................... - 9 -
OWTS CONSTRUCTION OBSERVATION ............................................................... - 10 -
LIMITATIONS ............................................................................................................. - 10 -
FIGURES
FIGURE 1 OWTS SITE PLAN
FIGURE 2 USDA GRADATION TEST RESULTS
FIGURE 3 SOIL TREATMENT AREA CALCULATIONS
FIGURE 4 SOIL TREATMENT AREA PLAN VIEW
FIGURE 5 SOIL TREATMENT AREA CROSS SECTION
FIGURE 6 DISTRIBUTION LINE CLEANOUT DETAIL
ATTACHMENT
VALLEY PRECAST 1,500 GALLON SEPTIC TANK DETAIL
AUTOMATIC DISTRIBUTING VALVES DETAIL
ORENCO PF3005 PUMP PERFORMANCE CURVE
Project No. 18-7-376.02
INTRODUCTION
This report provides the results of an onsite wastewater treatment system (OWTS) design for the
proposed residence located on Lot 7, Horse Mountain Estates, Alkali Creek Road, Eagle County,
Colorado. The purpose of this report is to provide design details for the OWTS in accordance
with the 2018 Eagle County Environmental Health Department Onsite Wastewater Treatment
System Regulations and the Colorado Department of Public Health and Environmental
Regulation #43. The services were performed as part of our agreement for professional services
to Joshua Boe dated May 23, 2018.
BACKGROUND INFORMATION
HP/Kumar recently performed a subsoil study for foundation design of the proposed residence at
the site dated August 20, 2018, Project No. 18-7-376. Information from that report has been
reviewed and considered in the preparation of the current OWTS design.
PROPOSED CONSTRUCTION
The proposed construction will consist of a four-bedroom residence with an attached garage and a
one-bedroom accessory dwelling unit (ADU)/workshop located on the lot as shown on Figure 1.
The ground floor of the residence will be constructed over crawlspace, and the attached garage
and the ADU/workshop will have a slab-on-grade ground floor. We understand that the residence
will be constructed in the near future and the ADU/workshop will be constructed a later date. The
soil treatment area (STA) for the OWTS will be located northwest of the residence. The OWTS
will be designed for five bedrooms based on the combined flows from the two structures. Water
service will be provided to the residence by an existing on-site well located as shown in Figure 1.
If proposed construction is different than that described, we should be contacted to re-evaluate our
design recommendations.
SITE CONDITIONS
During our recent site visit for the profile pit evaluations for the OWTS design, the property was
vacant and the ground surface appeared mostly natural in the area of the proposed STA. The site
has a dirt access road from Alkali Creek Road leading to the on-site water well.
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Project No. 18-7-376.02
The ground surface in the proposed STA slopes down moderately to the north. Slope grades
range from about 5 to 7% in the proposed building areas and STA. The water well is located to
the south of the proposed building and STA as shown on Figure 1. Minimum 100-feet and 50-
feet setbacks are required from the septic tank and STA to the well, respectively. Vegetation
consists primarily of sagebrush, grass and weeds.
SUBSURFACE CONDITIONS
Field exploration for the design was conducted by H-P/Kumar on May 29, 2018. Two profile pits
(Profile Pits 1 and 2) were excavated at the approximate locations shown on Figure 1 to evaluate
the subsurface conditions at the anticipated STA. Logs of the profile pits are provided below.
Log of Profile Pit 1
Depth USDA Classification
0-1½’ TOPSOIL; Clay Loam with organics, firm, moist, dark brown.
1½’-2½’ CLAY LOAM; with gravel and cobbles, moderate blocky structure, stiff, moist,
brown.
2½’-6½’ SILTY CLAY LOAM; strong blocky structure, very stiff, moist, brown. Bulk
sample obtained from 2½ to 3½ feet depth.
• Bottom of pit @ 6½ feet.
• No free water encountered during excavation.
• No redox features or indications of seasonal groundwater observed.
Log of Profile Pit 2
Depth USDA Classification
0-1½’ TOPSOIL; Clay Loam with organics, firm, moist, dark brown.
1½’-5’ SILTY CLAY LOAM; moderate blocky structure, very stiff, moist, brown.
• Bottom of pit @ 5 feet.
• No free water encountered during excavation.
• No redox features or indications of seasonal groundwater observed.
The soils encountered consisted of about 1½ feet of organic (Clay Loam) topsoil overlying Clay
Loam to Silty Clay Loam with moderate to strong blocky structure to the maximum depth explore
of 6½ feet. Gradation and hydrometer analyses were performed on a disturbed bulk sample at a
depth from 2½ to 3½ feet from Profile Pit 1 with the results provided on Figure 2. The laboratory
test results indicate the sample to be Silty Clay Loam soils per USDA classification.
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Project No. 18-7-376.02
In addition to the two profile pits, percolation testing was performed in two shallow holes hand-
dug holes in the bottom of backhoe pits on May 30, 2017. The percolation rates in the test holes
averaged about to 180 minutes per inch (mpi). Percolation test procedures outlined in Colorado
Department of Public Health and Environmental Regulation #43 were not utilized and the results
were only used for comparison with the soil profile pit evaluations.
Groundwater was not encountered in the exploratory pits at the proposed residence location to the
pit depths of 8 feet when dug on May 29, 2018 and the exposed soils were slightly moist. Based
on our experience in the area, groundwater level is likely more than 15 feet at the site.
Based on the subsurface conditions and laboratory testing, the soils at the STA have been
classified as Type 4 per State regulations, which equates to a long-term acceptance rate (LTAR)
of 0.20 gallons per square foot per day.
OWTS ANALYSIS
Based on the site conditions and profile pit evaluations, the evaluated area should be suitable for a
pressure-dosed infiltration disposal system. The system will consist of chambers in a trench
configuration. The STA will be sized for four bedrooms in the proposed residence (7 people) and
one bedroom in the ADU (2 people) for a total of 9 people using an LTAR of 0.20 gallons per
square foot per day.
The sewage will gravity flow from the residence and ADU to the septic tank for primary
treatment and then be pressured-dosed on a regular basis to the STA for dispersal and final
treatment. The STA will consist of eight trenches with Infiltrator chambers. Equal distribution
will be provided to the Infiltrators by an automatic distribution valve (ADV). Pressure-dosing to
the STA allows for a reduced field size. The pressure dosing was also used to provide equal
distribution to the relatively slow infiltrating soils at the STA.
A 100 feet minimum setback is required from the STA to the existing well located south of the
proposed STA. Based on site plan measurements, the well appears to be approximately 160 feet
from the STA. The location of the field with respect to the well should be confirmed prior to
construction of the field to verify adequate set-back.
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Project No. 18-7-376.02
DESIGN RECOMMENDATIONS
The design recommendations presented below are based on the proposed construction, the site
and subsurface conditions encountered and our experience in the area. Locations of the system
components are provided on Figure 1. If conditions encountered during construction are different
than those that are described in this report please contact us and we will re-evaluate our design
recommendations.
SOIL TREATMENT AREA
• The treatment system will consist of eight trenches with 20 Infiltrator Quick 4 Plus Standard
chambers in each (160 chambers total) placed on the native Silty Clay Loam and Clay Loam
soils. A pressure distribution system will be used to disperse the effluent to the trenches.
• The STA was sized based on an LTAR of 0.20 gallons per square feet per day.
• Each chamber was allowed 12 square feet of area. A 20% reduction in the STA size was
applied for pressure dosing and a 30% reduction of the STA size was applied for use of
Infiltrator chambers in a trench configuration. The total STA is 1920 square feet. Soil
treatment area calculations are shown on Figure 3.
• Distribution lines, consisting of 1.5-inch diameter, Schedule 40 piping, with ⅛-inch orifice
holes drilled at 4-foot centers near the center of the infiltrators, should be installed along the
complete length of the infiltrators in each trench (Figure 4). The distribution lines should be
suspended approximately 2 inches from the top surface of the infiltrators by pipe ties. The
orifice holes should face up toward the infiltrator surface above.
• A ⅛-inch hole should be drilled on the bottom of each end of each distribution pipe to allow
for complete drainage of the pipe after each dosing.
• Manifolds will connect adjacent trenches in pairs for a total of four manifolds.
• A minimum of four feet of undisturbed soils between trenches is required.
• The trenches should be oriented along ground contours to minimize soil cut and cover.
• The base and sidewalls of the trench excavations should be scarified prior to the chamber
placement.
• A minimum of 12 inches and a maximum of 24 inches of cover soil should be placed over the
chambers.
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Project No. 18-7-376.02
• Backfill should be graded to deflect surface water away from the STA and should be sloped at
3 horizontal to 1 vertical maximum. This is especially important along the up-slope side of
the field where a swale may be needed.
• Disturbed soil should be re-vegetated as soon as possible with a native grass mix. No trees,
shrubs or other plants with deep roots should be planted on or near the STA as this may
damage the system piping.
• Four-inch diameter inspection ports should be installed vertically into the knockouts provided
in the Infiltrator end caps. Install vents at each end of each trench. The inspection port piping
should be screwed into the top to the chambers and should not extend down to the ground
surface inside the chambers. The inspection ports should extend at least 8 inches above the
finished ground surface or be protected in a valve box at finished grade.
• A plan view of the STA is presented on Figure 4 and a cross section of the STA is presented
on Figure 5.
• Cleanouts are required in each of the distribution lines. See Figure 6 for the cleanout detail.
OWTS COMPONENTS
Recommended OWTS components provided below are based on our design details and our
experience with the specific component manufacturers. Equivalent components may be feasible
but need to be approved by us prior to construction.
Septic Tank
• A 1,500 gallon, three chamber Valley Precast septic tank (2,000-gallon total size) is proposed
for primary treatment and dosing to the STA. The first two chambers of the tank will be
utilized for treatment and settling, and the third chamber will contain the dosing pump. A
detail of the tank is provided as an attachment to the report.
• A submersible effluent pump enclosed in a Biotube Pump Vault will be installed in the third
chamber.
• The tank must be set level. The excavation bottom must be free of large rocks or other objects
that could damage the tank during placement. A road base or gravel bedding material may be
needed to act as a leveling course and prevent tank damage during placement.
• Install tank with 2 feet minimum cover soil for frost protection. Maximum tank soil cover
depth is 4 feet.
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Project No. 18-7-376.02
• The septic tank lids must extend to final surface grade and made to be easily located.
Sewer Pipe
• The sewer lines from the residence and ADU/workshop to the septic tank should not be less
than the diameter of the building drain and not less than 4 inches in diameter.
• The sewer pipe should have a rating of SDR35 or stronger.
• The sewer pipe should be sloped between 2% to 4% to help limit disturbance of solids in the
tank and potential sewage bypass of the first chamber of the tank. If a steeper slope is needed,
this can be accomplished with vertical step-downs in the sewer line.
• A minimum 36 inches of cover soil should be provided over the sewer pipe. Paved areas,
patios or other areas without vegetative cover may be more susceptible to frost. We
recommend 48 inches of soil cover over the sewer pipe in these areas and the pipe be
insulated on top and sides with 2-inch thick blue foam insulation board. If adequate soil cover
is not possible, we should be contacted for re-evaluation prior to installation.
• The sewer line should be double encased with larger diameter schedule 40 PVC pipe
underneath the driveway surface and any other areas subjected to vehicle traffic, and be
provided with at least 48 inches of soil cover and be insulated on top and sides with 2-inch
thick foam board insulation.
• The sewer pipe should be bedded in compacted ¾ inch road base or native soils provided that
the native soils contain no angular rocks or rocks larger than 2½ inches in diameter to help
prevent settlement of the pipe. Sags could cause standing effluent to freeze and damage
piping.
• Install cleanout pipes within 5 feet of the building foundation, where the sewer pipe bends 90
degrees or more and every 100 feet of sewer pipe. Our recommended clean-out locations are
shown on Figure 1
• All 90-degree bends should be installed using a 90 degree long-sweep or by using two 45
degree elbows.
• The sewer line locations shown on Figure 1 are considered conceptual. We assume that there
will be only one sewer line exiting the residence and ADU/workshop each. It is the
responsibility of the owner and/or contractor to locate all sewer line exit locations and
connections to the septic tank. We should be notified if there are other sewer lines exiting the
structures.
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Project No. 18-7-376.02
• The sewer lines form the residence and the ADU/workshop should be connected by a
downstream facing wye. A tee fitting is not suitable for this application.
Effluent Transport Piping
• 1.5-inch diameter Schedule 40 effluent transport piping should be sloped at 2% minimum to
drain back from the ADV to the dose tank and from the ADV to each trench. The ADV must
be the high point of the system
• The effluent transport pipe should be bedded in compacted ¾ inch road base or native soils
provided that the native soils contain no angular rocks or rocks larger than 2½ inches in
diameter to help prevent settlement of the pipe. Sags could cause standing effluent to freeze
and damage piping.
• A minimum 18 inches of cover soil should be provided over the effluent transport pipe.
Paved areas, patios or other areas without vegetative cover may be more susceptible to frost.
We recommend 48 inches of soil cover over the effluent pipe in these areas. If adequate cover
soil is not possible the effluent pipe should be insulated on top and sides with 2-inch-thick
foam insulation board and the design engineer should re-evaluate soil cover prior to
installation.
• The effluent pipe should be double encased with larger diameter Schedule 40 PVC pipe
underneath driveway surfaces and be provided with at least 48 inches of soil cover and be
insulated on top and sides with 2-inch-thick foam insulation board.
• All 90-degree bends should be installed using a 90 degree long-sweep or by using two 45
degree elbows.
Effluent Pumping System
• An Orenco PF3005, 115 volt, submersible effluent pump with a 1.25 inch diameter
discharge assembly, or equivalent, will be required for effluent pumping.
• The maximum effluent transport distance from the pump discharge to the ADV is
estimated to be 30 feet. The distance from the ADV to the STA manifolds is estimated to
be an additional 70 feet.
• The elevation difference from pump discharge to the ADV is estimated to be 5 feet.
• The pump should be enclosed in an Orenco Biotube Pump Vault for effluent filtering and
protection of the pump from vibration.
- 8 -
Project No. 18-7-376.02
• An equivalent pump must be capable of operating at 15.6 gallons per minute at 16.9 feet
of total dynamic head. A pump performance curve is provided as an attachment to this
report.
• The floats should be set to provide a dose volume of approximately 141 gallons. The
actual dose volume will be about 113 gallons assuming 28 gallons of drainback in the
transport line. To achieve the desired dose volume the upper (“ON”) and lower (“OFF”)
floats should be set approximately 14 inches apart.
• The flow differential between the first and last orifices is estimated to be 1.0%.
• The high water alarm float should be placed approximately 3 inches above the “ON” float
in the dose tank. The high water alarm must be wired on a separate electrical circuit from
the pump.
• A ⅛ inch diameter weep hole should be drilled in the effluent transport line prior to
exiting the dose tank so the transport line can drain after each pumping cycle.
Automatic Distributing Valve
• An Orenco V6404 Automatic Distributing Valve (ADV) will be used to alternate doses to
the four pairs of STA trenches.
• The ADV must be installed level and must be the high point in the system.
• The ADV should be installed in a sprinkler box, or equivalent, such that it is serviceable
and protected from freezing. We recommend the ADV be equipped with heat tape for
additional frost protection during winter months.
• We recommend the ground surface be graded away from the ADV in all directions.
Improper surface drainage could cause standing water to freeze and damage the valve
and/or piping.
• The valve has clear sections of pipe that should be inspected at least annually to ensure
that it is alternating doses to each trench.
OWTS OPERATION AND MAINTENANCE
The OWTS will require periodic inspection and maintenance to function properly. A properly
designed, installed and maintained system can greatly increase its lifespan. The level of
maintenance will vary depending on the complexity of the system and water use habits of the
residents. We recommend that an OWTS Operation and Maintenance (O&M) Manual be
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Project No. 18-7-376.02
developed. Depending on the complexity of the system a contract with an OWTS maintenance
provider may be prudent. Below are some basic recommendations for the OWTS O&M.
OWTS HOUSEHOLD OPERATION
• Use of high efficiency water fixtures is recommended to decrease the hydraulic load on the
OWTS system.
• Fix plumbing leaks immediately as this may cause a hydraulic overload of the soil absorption
system.
• Do not irrigate the area on top of or directly upgradient of the soil absorption field as this may
cause a hydraulic overload.
• Do not dispose of household waste down household drains as this may clog or damage OWTS
components. Examples of household waste includes: dental floss, cotton swabs, coffee
grounds, paper towels, feminine products and many other kitchen and bath items.
• Use of kitchen garbage disposals is not recommended. If a garbage disposal is utilized,
kitchen wastewater should be screened thoroughly. Many kitchen solids are not decomposed
in the septic tank and may cause increased tank pumping frequency.
• Do not dispose of household chemicals, greases, oils, paints, hot tub water or water softener
backwash in household drains. A separate drywell, if feasible, may be necessary for hot tub
water or water softener backwash disposal.
• Limit the use of bleach as this may harm useful bacteria in the septic tank and soil absorption
system.
• Liquid dishwasher and clothes washer detergent is recommended for households served by an
OWTS. Clay substances used as fillers in powder detergents may result in clogging of the
soils absorption system.
• The effluent in septic tanks can freeze during extended periods of non-use in cold weather.
We recommend that a tank heater be installed in this system to help prevent freezing.
OWTS MAINTENANCE
• Inspect the septic tank, pump, pump vault filter, ADV and STA at least annually for problems
or signs of failure.
- 10 -
Project No. 18-7-376.02
• The filter should be cleaned annually by spray washing solids into the first chamber of the
septic tank.
• The septic tank should be pumped and cleaned every 3 to 5 years depending on use. Longer
pumping intervals may increase the amount of solids that reach the STA, which may shorten
its life span.
• Pumping of the septic tank should take place when the level of the sludge and scum layers
combined take up 25 to 33% of the capacity of the first chamber of the tank.
OWTS CONSTRUCTION OBSERVATION
The Eagle County Environmental Health Department requires that the designer of the system
provide a record drawing and certification of the OWTS construction (As-Built inspection). We
should be provided with at least 48 hour notice prior to the installer needing the inspections. Prior
to issuance of our certification letter, we require observation of all system components prior to
backfill. The number of site visits required for the inspection will depend on the installer’s
construction schedule.
LIMITATIONS
We have conducted this design in accordance with generally accepted engineering principles and
practices in this area at this time. We make no warranty either expressed or implied. The
recommendations provided in this report are based on the site conditions, profile pit evaluations,
soil texture anal ysis, the proposed construction and our experience in the area. Variations in the
subsurface conditions may not become evident until excavation is performed. If conditions
encountered during construction appear different from those described in this report, we should be
notified so that re-evaluation of the recommendations may be made.
This report has been prepared for the exclusive use by our client for design purposes. We are not
responsible for technical interpretations by others of our information. As the project evolves, we
should provide continued consultation and field services during construction to review and
monitor the implementation of our recommendations, and to verify that the recommendations
have been appropriately interpreted. Significant design changes may require additional analysis
or modifications to our design.
USDA GRADATION TEST RESULTS
1 MIN.
4 MIN.19MIN.15 MIN.60MIN.#325 #140 3/4"3/8"1 1/2"3"5"6"8"
DIAMETER OF PARTICLES IN MILLIMETERS
U.S. STANDARD SERIES CLEAR SQUARE OPENINGS
SIEVE ANALYSIS
TIME READINGS
HYDROMETER ANALYSIS
#4#10#18#35#60
7 HR
45 MIN.24 HR.
0
10
20
30
40
50
100
90
80
70
60
50
60
70
80
90
100
0
10
20
30
40
20315276.237.519.09.54.752.001.00.500.025.106.045.019.009.005.002.001
SILT COBBLESLARGE
GRAVEL
MEDIUMCOARSEMEDIUMV. FINE
SAND CLAY FINE V. COARSE SMALL
USDA SOIL TYPE:
GRAVEL %SILT %CLAY %
FROM:PROFILE PIT 1 @ 212 - 312 FEET
0 16 33SAND %51
SILTY CLAY LOAM
ORENCO
V6404
AUTOMATIC
DISTRIBUTING
VALVE
1.5" DIAMETER
SCH. 40
NON-PERFORATED
PVC PIPE
SLOPED AT 2%
MIN. TO DRAIN
BACK TO DOSE
TANK
Line Fl
o
w
From T
a
n
k
INFILTRATOR
QUICK 4 PLUS
STANDARD
END CAP
INFILTRATOR
QUICK 4 PLUS
STANDARD
CHAMBERS IN 8
TRENCHES. 20
CHAMBERS IN
EACH TRENCH
(160 TOTAL).
DRILL ONE 18" DIAMETER HOLE ON THE BOTTOM
OF EACH END OF EACH DISTRIBUTION PIPE TO
ALLOW FOR COMPLETE DRAINAGE. INSTALL
SPLASH PLATES BENEATH DRAIN HOLES
CLEANOUTS INSTALLED
AT END OF EACH
DISTRIBUTION LATERAL.
SEE FIGURE 6 FOR DETAIL
1.5" SCH. 40 PVC
DISTRIBUTION PIPE WITH
18" DIAMETER HOLES
DRILLED AT 4 FOOT
CENTERS ON TOP OF
EACH PIPE. PLACE HOLES
NEAR CENTER OF EACH
CHAMBER. PIPE TO BE
INSTALLED LEVEL AND
SECURED WITH 120 LB.
MIN. TENSILE STRENGTH
CABLE TIES AT EACH END
OF EACH CHAMBER.
1.5" DIAMETER
SCH. 40
NON-PERFORATED
PVC PIPE
SLOPED AT 2%
MIN. DOWN TO
EACH TRENCH
4 INCH DIAMETER PVC OBSERVATION
PORTS INSTALLED VERTICALLY INTO
KNOCKOUTS PROVIDED IN END CAPS.
INSTALL VENTS AT EACH END OF EACH
TRENCH. REMOVABLE LID TO BE
PLACED ON TOP OF PIPE. PIPE MUST
STICK UP AT LEAST 8 INCHES ABOVE
FINISHED GRADE OR BE PLACED AT
GRADE IN AN ACCESSIBLE VALVE BOX.
PIPES SHOULD NOT EXTEND TO SOIL
SURFACE AND SHOULD BE SECURED
TO CHAMBER WITH SCREWS OR
COUPLINGS TO PREVENT SLIDING
DOWNWARD.4' min. undisturbed soil between trenches (typical)NOT TO SCALE
Notes
1.Chambers should be installed level on a scarified ground surface. Concrete sand may be used as a leveling course if
needed.
2.Care should be taken by the contractor to avoid compaction of the native soils in the trench areas. The base and side walls of
trench excavations should be scarified prior to chamber installation.
3.Fill placed over the soil treatment area should be properly benched into the hillside.
4.Changes to this design should not be made without consultation and approval by H-P/Kumar.
6.Refer to the 2018 Eagle County Onsite Wastewater System Regulations for other applicable specifications.
Infiltrator Quick 4
Plus Standard
End Cap
Infiltrator Quick 4 Plus
Standard Chamber
Installed Level
Approx. Existing Ground Surface
12" min. 24" max.
Cover Soil Graded to
Deflect Surface Water
Scarify ground
surface prior to
chamber placement.
Native Soil
Excavate
36" Wide
Trench
4' min.
Undisturbed Soil
Between Trenches
Notes
1.Chambers should be installed level on a scarified ground surface. Concrete
sand may be used as a leveling course if needed.
2.Care should be taken by the contractor to avoid compaction of the native soils in
the trench areas. The base and side walls of trench excavations should be
scarified prior to chamber installation.
3.Changes to this design should not be made without consultation and approval
by H-P/KUMAR
APPR2;IMATE SCALE
1 INCH 1 )EET
Ground Surface
Insulate lid with 2"
blue board
Backfill valve box to bottom
of cap with onsite soil
1.5" Sch. 40, 90° long-sweep
or two 45° elbows
1.5" Sch. 40,
threaded cap
Install 6" valve box at
ground surface
APPROXIMATE SCALE:
1 INCH = 2 FEET
Notes:
1.All piping, fittings and valves should be Sch. 40 P9C.
2.Install distribution line cleanouts at the end of each distribution line.
Pump Selection for a Pressurized System - Single Family Residence Project
Lot 7, Horse Mountain / Eagle County
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
30
40
1.50
6404
90
40
1.50
5
7
40
1.50
8
70
40
1.50
1/8
4
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
0.43
36
15.6
2
1.0
2.5
2.5
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
1.7
0.5
3.2
1.4
0.0
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
3.2
9.5
0.7
14.8
3.2
25.1
gals
gals
gals
gals
gals
gals
Minimum Pump Requirements
Design Flow Rate
Total Dynamic Head
15.6
16.9
gpm
feet
0 5 10 15 20 25 30 35 40
0
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: