HomeMy WebLinkAboutOWTS Design Packet 06.16.202033 FOUR WHEEL DRIVE ROAD
CARBONDALE, CO 81 623
970.309.5259
CARLA.OSTBERG@GMAI L. COM
('(>\tii'I:I'I\(:
June 16, 2020
Daniel Bucio
mdconstructionlIc14@gmail.com
Subsurface Investigation and Onsite Wastewater Treatment System Design
5-Bedroom Residence
TBD Lafrenz Lane
Garfield County, Colorado
Daniel,
Project No. C1530
CBO Inc. performed a subsurface investigation and completed an onsite wastewater treatment system
(OWTS) design for the subject residence. The 6.717-acre property is located outside of Silt, in an area
where OWTSs and wells are necessary.
Legal Description: Section: 25 Township: 5 Range: 92 AMENDED TRACT 36, AMENDED FINAL PLAT
TRS 29 & 36 & PT OF TRS 28, 30 & 37 OF ANTLERS ORCHARD DEV.
Parcel ID: 2127-251-00-069
SITE CONDITIONS
The property is currently undeveloped. A 5-bedroom, single-family residence is proposed.
The residence will be served by a private well on the property. The well will be greater than 50-feet from
the proposed septic tank and greater than 100-feet from the proposed soil treatment area (STA).
The proposed soil treatment area (STA) location slopes slightly to the southwest at an approximate 5%
slope. The proposed area is located in an open field area covered with native vegetation.
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.
SUBSURFACE
The subsurface was investigated on June 16, 2020 by digging one soil profile test pit excavation (Test Pit).
Only one test pit was excavated as the machine was removed from the property prior to our arrival. A visual
and tactile soil analysis was completed by Carla Ostberg.1
The materials encountered in the Test Pit #1 consisted of light brown to whitish clay loam to 4.0-feet ,
underlain by light brown clay loam to a maximum depth explored of 8.0-feet. No bedrock or groundwater
was encountered.
' Carla Ostberg holds a Certificate of Attendance and Examination from the CPOW Visual and Tactile
Evaluation of Soils Training.
Page 2
A sample of the soils was taken from Test Pit #1 at 3-feet below grade. The soil formed a ball and a
ribbon 1 to 2-inches in length before breaking. Soil structure shape was blocky and consistence was
firm. Soil texture was more smooth than gritty.
STA sizing is based on Soil Type 3, Clay Loam with moderate structure grade. A long term acceptance
rate (LTAR) of 0.35 gallons per square foot will be used to design the OWTS.
Test Pit #1
Firm peds in soil / not rock
Page 3
Sieved sample
ribbon 1-2" in length before breaking
DESIGN SPECIFICATIONS
Design Calculations:
Average Design Flow = 75 GPD x 2 people/bedroom x 3 Bedrooms + 150 GPD (4th and 5th bedrooms) = 600
GPD
LTAR = 0.35 GPD/SF
600 GPD / 0.35 GPD/SF x 1.0 (gravity trenches) x 0.7 (chambers) = 1200 SF
The new OWTS design is based on 5-bedrooms. An average daily wastewater flow of 600 GPD will be
used.
For the purposes of this OWTS design, Benchmark Elevation has been established as 100' as the
approximate elevation of the sewer line exiting the residence (5868'). 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 (approx. 5868')
Approx. horizontal distance 30' / min. 2% slope /
min. 7.5" fall
Distribution Box (approx. 5860')
Approx. horizontal distance 62' / min. 1% slope /
min. 8" fall
Infiltrative Surface
Approx. horizontal distance 12' / min. 1 % slope /
min. 1.5" fall
The 4-inch diameter SDR-35 sewer line exiting the residence must have a double -sweep clean out and a
minimum 2% grade to the septic tank.
The system installation must include a 1500-gallon, two -compartment Valley Precast concrete septic tank
with an effluent filter on the outlet tee. Risers must bring the manhole lids to grade for access. If more
than one riser is added to the septic tank, an extension handle must be installed on the effluent filter.
Effluent will gravity flow to a distribution box, and then to five gravelless chamber trenches. The
distribution box must be accessible from grade and must have flow equalizers, or similar product,
installed on each outlet pipe in the distribution box to assure equal flow to each bed.
Page 4
Each trench will consist of 20 `Quick 4' Low Profile Infiltrator® chambers for a total of 1200 square feet of
infiltrative area. There must be at least 4-feet of undisturbed soil between each trench. We recommend
a shallow installation of approximately 2-feet below grade. Inspection ports must be installed at the
beginning and end of each trench. Ports may be cut to grade and placed in sprinkler boxes 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.
COMPONENT
MANUFACTURER
MODEL NO.
COMMENTS
Septic Tank
Valley Precast
1500T-2CP
1500-gallon, 2-
compartment concrete
septic tank
Biotube Effluent Filter
Orenco®
Full Size Effluent Filter and
housing
Tank Risers and Lids
Orenco®
Double -walled PVC Risers and
Lids (24" diameter)
Distribution Box
Valley Precast
D-Box 8C
Concrete distribution box
Flow Equalizers
3049 Equalizer
5 Flow Equalizers
Chambers
Infiltrator®
Low Profile
100 'Quick 4' Low Profile
Chambers
The component manufacturers are typical of applications used by contractors and engineers in this area.
Alternatives may be considered or recommended by contacting our office. Construction must be
according to Garfield County On -Site Wastewater Treatment System Regulations, the OWTS Permit
provided by Garfield County Building Department, and this design.
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
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.
Page 5
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 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 6
Please call with questions.
Sincerely,
CBO Inc.
ems, (eL o��s,
Carla Ostberg, MPH, REHS
2
/
3
0
E
0
0
0
0
,s . ' ° ,00 o 00 N
J6a q
0 09 = 4 : -IVOS
2
67:
r
A.. I
'
,SS'i7S9 4,00, 000 00N
CBO Inc.
33 Four Wheel Drive Road
Carbondale, Colorado 81623
Phone 970.309.5259
carla.ostberg@gmail.com
O
D p
x F.
o)m73 m
w 73
m N r
m
O m m
-1 x
0.°f ' 0 m
. 2 O
.
'1#•••••::::••••#0.0%...
Bucio Residence
TBD LaFrenz Lane
Garfield County, Colorado
Project Number: C1530
_....11411
0000.111.- Ilk %
.. .#
2� ?y
��# W e
nC 0
o D A cn • Z— 1- zi
3m -1-o
w7 *mczi O<�p
m - v732 Ox ow
0O �Wr
z�/�Om
m
oA m= m x
7J
� � N
w61
oz Dcz)(J m
m m 2 c
zm mmn
00 �OxT
AIIIIIIIIPIPIP
mZ z��
DR�� �7 Iry
EwAY -I - CO
m� m�
* -1
m
nZ ��
r x7
mn rw
z? O m
-1
m z<-m
xx
v
mm-I
2
m
z
O
I
z
n
2 •
x9,
mco
cnm
00
m73
m0
3
M 100' (APPROX. 5868') /
\
�0
(n
Z
I m
r I
I
ii
m q C.
\-
O \\
\
\\ \
N
\ \�
\ \
\ \ /
\ \. \ /\�
\ \ OJ
Date: 06/16/20
Designed by: CBO
Drawn by: DD
/
\ \ \
\
\ ` \
\ \
\
\
\ \
\ \
\ \ \
\ \ \
W2.0
Sheet 2 OF 4
\
\ \
\ \
\ \
§ =_) co
/)\0/
e&-'2
cs
/\$
� 3 _ n
/r
D
E2E%
\ co/
a) - a_
0E563 :JequinN Paafoad
auel zuaadeq GEL
eoueppeN oi3n8
d0 E }aauS
oj
Q
33Vd2ins AdI V3S
]}
>-n
, v
0
/
HON3?!1 ?!3d S2:1381/WHO OZ
CO
�e—
ail
_ \
�
3WVOS 01 ION
11V130 le10d N01103dSNI
2\
/m
>
co o
\m
w
0£540 :JegwnN loerOad
0
\
0
E
0
2
k
\
eue-i zuauei a81
eoueppeu oi3n8
JO 17 leeLIS
b
�
§
0
z
§0
,X
kq
7
0
0
j
j0
0
an 31a10N00
/
BOX AND COVER BROUGHT TO GRADE
m- )u) 0/
m> >0 ze
r0 §\ §§
zT k0 r<
mo fe CO
\ \
q
,
DEPTH - FEET
| 1 | I | | I | I | I | I | I | I | I
I
±
co co® a) a - (A)e -
COOZ
0
00
mz
x
c
\
\
0 z0
®
_
0
0
0
0
0
1A1VO1 ,W10 NMObB 1H011
eee000r@ =2¥ Iwe
/dki(A/9 m7z woal Om
,-®§<C•-1&&
o
\§§o0mo
»Gxo%.>mm eo
\oph10ƒ� // mmm
m 1-1- = m
k\\/}>m ZZ 3 \�
®qo@q„m{ I 2 7m
0_1�„@>m » „ =z
\\\�_,,/9 / o 0�
/%q\\\§� \ / 0
�j§\X-- > x
m9mow> E \
}-k-n k m
m 0) 0 0
= 0
?�\> \ co
> \ m +
m $ § cp
m m 0
\ ] 0
/ 0-11
-1 -1
? >
/ z
mo
1
0
>
\
0
z
)V10 HSI-EIIHM 01 NMO?JB 1H011
6 ON lld 1S31 311d02Md 110S
%
0
m
z
0
EXISTING CONDITIONS SURVEY
Amended Tract 36, Amended Final Plat
Tracts 29 and 36 and a Portion of Tracts 28,30 and 37
Antlers Orchard Development Company Plat No. 1
•
l YaaYr t
1
•
I
116••
"w� aaa
a
Ita
felVerillifacarfaa
a aka. at pada *moat an900 $ Sal a SWIM. • Ma imam a
AIM
1, mai a 'leaf mesa op a
anemone sans se •••
w.s as w—._ a
aa••lralma — . an al a as
naafi Mai Mina San Maar ea /a na ant Una/ a*
111011•111 011ie, a•IRISII Haan Ma
alaala lay Vaal
IIMISMAIDIOI
anealar aiNlia000 MD Maul lieVe• Sal le ear
aceataa aa•Milandnealuali Mae Oa,
444 ISA MAP Munro
O SITE PLAN
a.
..--$- --;-
- -
�•
BUCIO RESIDENCE
tail ANTLERS ORCHARD
SILT. CO
A1.0