HomeMy WebLinkAboutAs-built Installation Report 11.27.2019November 27, 2019
Klein, Brian W & Michelle
1543 Beech Street
Rifle, Co, 8165
"ccrower4" ccrower4@gmail.com
RE: As -Constructed —Onsite Wastewater Treatment System (OWTS), Klein Residence, 209 County Road 263,
New Castle, Garfield County, Colorado
SE Job No. 18027, Parcel Number: 2181-051-01-295, County Permit #: SEPT -06-19-5819
Dear Brian & Michelle:
Pursuant to County requirements, this letter provides documentation that the new Onsite Wastewater Treatment
Systems (OWTS) recently installed at the above referenced site is in compliance with the permitted design. Sopris
Engineering inspected the excavations, soils, materials and the installation of the system components at various
times during construction, prior to final backfill and after all installations was completed. The system constructed
on site was designed and built to serve the needs of the residence currently under construction. The installed system
was designed with a minimum treatment capacity equivalent for a typical 3 -bedroom home. Sopris Engineering
performed site visits to inspect and document the as -built conditions of the constructed system. Inspections were
coordinated with the earthmoving contractor, J Caliber Construction. The as -built conditions and installation of the
new OWTS components is in compliance with County Regulations; the recommendations and specifications
delineated on the civil building permit plan C3.0, OWTS plan and Engineering Design report, dated 08-07-2018, by
Sopris Engineering. The subject site is located north of State Highway6 on the west side of County Road 263, in
New Castle situated on Lot 1, Block 1, CCP Subdivision in section: 5 Township: 6 Range: 91 of the 6th P.M.,
Garfield County, Colorado.
The OWTS was constructed and completed in October of 2019 by Jose Gonzales, Caliber Construction,
1196 E 17`h Street, Rifle, CO 81650, 970-314-0489.
The design criteria and system sizing information is summarized below. An As -Constructed OWTS record drawing
is attached delineating the descriptions and location of the components.
Summary Design Criteria
The OWTS is designed for a treatment capacity of 450 gallons per day based on the design wastewater flow to serve
a 3 -bedroom residence in accordance with Table 6-2 values, Section 43.6, A.4. The OWTS includes the installation
of a 1000 gallon 2 -compartment concrete septic tank with risers and lids installed at the surface. The tank was
installed with an inlet sanitary tee and an outlet effluent filter sanitary tee. A gravity schedule -40 or SDR -26 sewer
pipe with a cleanout was installed from the residential structure to the tank. The soil treatment unit (STU) consists
of leaching chamber trenches that provide 630 S.F. of total absorption area. The septic tank effluent is gravity
discharged to the STU via a distribution box. The effluent is equally distributed from the distribution box via 4"
distribution pipes connected to the head end cap in each chamber trench. Observation ports with caps are installed
on each end chamber unit. The design is in compliance with the current County regulations with design
calculations based on the soil type, texture and structure with an appropriate long term acceptance rate (LTAR).
The designed system meets all required setbacks and has been installed within the general location indicated on the
record drawing plan.
502 Main Street • Suite A3 • Carbondale, CO 87623 • (970) 704-0377
• Fax (970) 704-0373
SOPRIS ENGINEERING • LLC
civil consultants
Anderson/Compton, AC-OWTS,
37 Silver Vain Dr
SE Job No. 18178.02
November 27, 2019
Page2
Sub Surface Conditions and Observation
A subsurface soil investigation and site assessment was performed by Sopris Engineering in on March 7, 2018. The
soils in the proposed field envelope area were sampled and characterized by application of the USDA visual/tactile
soil texture method analysis. The soils below 6 to 12 inches of topsoil consist of medium dense sandy silt loam soil
with moderate granular to fine grained structure with less than 5% scattered gravels and cobbles to 5 feet below the
surface grades. The deeper underlying soils are composed of sandy clayey loam soils with less than 10% scattered
gravels and cobbles. The soils appear to be consistent across the site from observations in the two excavated profile
pits.
The native soils sampled from 1-3 feet below the surface are characterized as a soil type 2A consisting of silt loam
texture with granular structure. This soil has an effective loading rate for conventional soil treatment of 0.5
Gal/S.F./day for a level 1 conventional treatment system. The equivalent percolation rate is assumed to be 26-40
minutes per inch. No free water was encountered in excavations on site. Seasonal high Groundwater levels are
expected to be below 10 feet from the existing surface grades. The soils are suitable for a shallow conventional
shallow absorption field consisting of gravelless infiltration chamber units.
Design Flow
The design flow is calculated as follows for a single family residence onsite wastewater treatment system (OWTS).
The treatment capacity is designed for an equivalent 3 -bedroom residence.
From the Regulation 43 usage table :
Minimum population based on 3 bedrooms = 6 persons.
Gallons per day per person =75 gal/person/day, No peaking factor
Max. Design flow (Qd)gallons/day = (# of people) x (avg. flow)gal/person/day.
Design flow Qd = 6*75=450 gpd
The septic tank capacity required for a minimum 48 hour detention time is calculated as follows:
V = 450 gal/day * 2 = 900 gallons
A 1000 gallon, two compartment concrete septic tank with an effluent filter outlet sanitary tee in the second
compartment was installed with sealed concrete risers and fiber lids to the finish surface grade.
Treatment -Soil Treatment Unit/ Absorption System Design
The Soil Treatment Unit (STU) field was designed based on utilizing the effective Long Term Acceptance Rate
(LTAR).
Long Term Acceptance Rate (LTAR)
Receiving Wastewater Treatment Level 1; loading rate for silt loam is (0.50 gal./S.F./day) for soil type 2A.;
Loading factors; (Table 10-2, Gravity application trenches = 1.0) and
(Table 10-3, gravelless chambers = 0.7)
A(sf) = 450 gpd x 1.0 x 0.7 = 630 S.F.
0.50 Gal/S.F./day
Anderson/Compton, AC-OWTS,
37 Silver Vain Dr
SE Job No. 18178.02
November 27, 2019
Page3
Installed 54 Infiltrator Quick -4 with end caps in three trenches 74' long by 3' wide with 18 chambers units per
trench.
OWTS Operation and Maintenance
Responsibility for maintenance and repair of the installed OWTS will remain with the property Owner. The Owner
is encouraged to retain the services of qualified personnel to inspect the OWTS and to perform all maintenance and
repairs necessary to ensure that the system components are maintained in good operating condition and suitable
vegetative cover is established on the fields. The components of the OWTS system should inspected within 30 days
of being placed into operation and should been inspected and maintained bi-annually. The tank, absorption field
and other system components should be visually inspected bi-annually for debris, damage, leaks, or other potential
problems. In general, for a properly utilized system, septic tanks should be pumped every 3 - Syears. The effluent
filter should be cleaned every six months and at the time of pumping. Absorption fields should be maintained with
suitable vegetative cover and kept free of root invasive plants. Positive surface drainage away from the absorption
field should be maintained.
If you have any question or need any additional information, please call.
Sincerely,
SOPRIS ENGINEERING, LLC
Paul E. Rutledge
Design Engineer
28377
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Yancy Nichol, PE
Principal