HomeMy WebLinkAboutOWTS As-Builts4''S
S
4''SS
4''SS
4''SS
4''SS
4''SS
4''SS
4''SS
4''SS
4''SS
4''SS
50.4'
10.0'
6
6
43
6 6 4 1
6 6 4 2
6640
6 635
6633
66346635
6 6 3 6
648.0' DIST TO EX WELL
10.1
4''SS
4''SS
INSTALLED 4" 2-WAY CLEANOUT
CHAMBER BED STA FIELD USED 30 ARC
CHAMBERS IN 3 TRENCHES 50' LENGTH WITH 10
CHAMBERS PER TRENCH PLUS END CAPS FOR A
TOTAL ABSORPTION AREA OF 450 S.F.
4" SDR-35 OR SCHD-40 DISTRIBUTION PIPES INSTALLED AT
MIN. 1% TO CHAMBER END CAP AT HEAD OF EACH TRENCH
4" SCHD-40
PVC SEWER PIPE @ 2%,
INSTALLED CHAMBER END CAP
ON ALL END CHAMBERS
1.5" SCHD-40 EFFLUENT PIPE. INSTALLED
AT MIN. 2.0% TO D-BOX
PLASTIC DISTRIBUTION BOX WITH BAFFLE
INSTALLED LEVEL ON COMPACTED BASE WITH
RISER AND LID AT SURFACE GRADE
GARAGE/SHOP W/ 1
2 BATH STRUCTURE
UNDER CONSTRUCTION
FUTURE 2-BEDROOM ADU PENDING
INSTALLED 4" INSPECTION PORT EXTEND PIPE RISER FROM END
CHAMBER IP FLANGE TO FINISH GRADE W/ PUSH ON CAP & COVER
WITH 8" DIA. VALVE BOX SET WITH LID 4" ABOVE FINISH GRADE
(TYP. EACH DISTAL END CHAMBER EACH ROW )
INSTALLED A 2-COMPARTMENT 1250-GALLON NORWESCO PLASTIC TANK
INSTALLED INLET SANITARY TEE & OUTLET EFFLUENT FILTER ASSEMBLY.
INSTALLED WITH (2) 24" DIA. BY 30" DEEP CONCRETE RISERS WITH LIDS.
TOP OF RISERS/LIDS TO BE INSTALLED @ + 3" ABOVE FINISH GRADE.
INSTALLED INTERMEDIATE 4" CLEANOUT
INSTALLED 4" INSPECTION PORT EXTEND PIPE RISER FROM END
CHAMBER IP FLANGE TO FINISH GRADE W/ PUSH ON CAP & COVER
WITH 8" DIA. VALVE BOX SET WITH LID 4" ABOVE FINISH GRADE
(TYP. EACH PROXIMAL END CHAMBER EACH OUTER ROW)
DATE REVISION
C-1.0
DRAWING NO.
TITLE
G:
\
2
0
2
5
\
3
5
0
4
1
1
4
2
0
C
R
1
0
7
\
A
S
-
B
U
I
L
T
S
\
3
5
0
4
1
-
O
W
T
S
A
C
.
D
W
G
-
M
a
r
1
6
,
2
0
2
6
-
4
:
4
0
p
m
NO
R
T
H
OWTS
AS-CONSTRUCTED
RECORD DRAWING
PLAN
1 inch = ft.
( IN FEET )
GRAPHIC SCALE
010 10 20
10
405
35041.01JOB NO.
DATE:03-16-26
AC COND BY
DRAWN BY
CHECKED BY
PER 09/05/25
WJB 09/05/25
BR
O
A
D
H
U
R
S
T
R
E
S
I
D
E
N
C
E
G
A
R
A
G
E
/
S
H
O
P
1
4
2
0
C
O
U
N
T
Y
R
O
A
D
1
0
7
CA
R
B
O
N
D
A
L
E
,
C
O
L
O
R
A
D
O
OW
T
S
A
S
-
C
O
N
S
T
R
U
C
T
E
D
R
E
C
O
R
D
D
R
A
W
I
N
G
SO
P
R
I
S
E
N
G
I
N
E
E
R
I
N
G
L
L
C
50
2
M
A
I
N
S
T
R
E
E
T
S
U
I
T
E
A
3
C
A
R
B
O
N
D
A
L
E
C
O
8
1
6
2
3
(9
7
0
)
7
0
4
0
3
1
1
s
o
p
r
i
s
e
n
g
i
n
e
e
r
i
n
g
.
c
o
m
The onsite wastewater treatment system (OWTS) was installed to serve an ADU over the new garage.
The design flow treatment capacity is calculated as follows for a minimum equivalent 2-bedroom single family
residence.
From the Regulation 43 usage table :
Minimum population based on 2 bedrooms = 4 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 = 4*75=300 gpd
Septic Tank Design:
Used a 1250 gallon, two compartment plastic septic tank with an effluent filter outlet sanitary tee in the second
chamber. Tank was installed with sealed plastic risers and lids to the finish grade surface.
Preliminary Sub Surface Conditions and Testing:
A subsurface soil investigation and site assessment was performed by Sopris Engineering on April 17, 2025. The
soils in the proposed field envelope area were sampled and characterized by application of the USDA
visual/tactile soil texture method analysis from samples in two profile pits. The soils below approximately 6
inches of topsoil consist of medium dense silt loam texture soil with slightly blocky to granular structure to the
profile pit depth of 8 feet. The soils contain less than 5% scattered gravel or rock content to the 8-feet depth
explored below the surface grades. No free water was encountered in the pit excavations. No evidence of
seasonal high ground water or redox conditions was observed in the profile pits. Seasonal high Groundwater
levels are expected to be below 20 feet from the existing surface grades on the moderately sloped terrain.
The native soils sampled from 2-3 feet below the surface, in the vicinity of the proposed field, are characterized
as a soil type 2 consisting of silt loam texture with blocky granular structure. This soil has an effective loading
rate for conventional soil treatment of 0.6 Gal/S.F./day for a level 1 conventional treatment system. The
equivalent percolation rate is assumed to be 20-30 minutes per inch. The soils are suitable for a shallow
conventional absorption field consisting of gravelless infiltration chamber units.
Soil Treatment Unit/ Absorption System Design:
The treatment/absorption field is designed based on utilizing the effective Long Term Acceptance Rate (LTAR)
for the native soils and the application of appropriate loading factors for a soil treatment unit system utilizing
gravity distribution to gravelless chamber trenches. The new treatment system and absorption field consists of
gravity distribution of septic tank effluent via a distribution box to a chamber bed with treatment across the
native soil absorptive surface.
Long Term Acceptance Rate (LTAR):
Considering the application of the state regulation 43:
Receiving Wastewater Treatment Level 1;
LTAR; (Table 10-1 Soil type 2 loading rate for a silt loam is (0.6 gal./S.F./day);
Design Flow; Qd = flow (gal/day) = 450 gpd
Loading factors; (Table 10-2, Gravity application bed, L.F.1 = 1.2 )
(Table 10-3, Gravelless chambers, L.F.2 = 0.7)
STA absorption treatment area; A = Area S.F.;
A(sf) = Qd x L.F.1 x L.F.2 .: A(sf) = 300 gpd x 1.2 x 0.7 = 420 S.F.
LTAR 0.6 Gal/S.F./day
Number of Quick-4 Infiltrator chambers 4'x3'x12"chambers:
420 S.F. = 35 chambers; Use 36 chambers
12 S.F./Chamber
Number of Equivalent Arc chambers 5'x3'x12"chambers:
420 S.F. = 28 chambers; Use 30 chambers
15 S.F./Chamber
Used 30 Arc chambers in 1 bed with 3 trenches 50' long by 3' wide with 10 chambers units per row plus two end
caps as delineated on the plan. The septic tank effluent is gravity distributed to the head of each chamber row
via individual distribution pipes from a distribution box.
1.THE OWTS AS SHOWN ON THE PLAN AND THE DETAILS WERE DESIGNED BY SOPRIS ENGINEERING.
2.THE PROPOSED LOT CONDITIONS BY SOPRIS ENGINEERING AND OWNERS
3.THE EXISTING LOT CONDITIONS PER COUNTY GIS DATABASE, AERIAL MAPPING, LIDAR TOPOGRAPHY.
4.PRIMARY OWNER NAME AND ADDRESS: BROADHURST, CHRISTOPHER J & TAMARA MARIE, PO BOX 1132,
CARBONDALE, CO 81623
5.SITE ADDRESS: 1420 County Rd 107, Carbondale, CO 81623
6.Legal Summary: Section: 22 Township: 7 Range: 88 TR IN N1/2SW 10.070 ACRES
7.Parcel Number: 239322300114
8.Previous Garfield County ISDS Permit# 03420 Issued: 12/10/2001
9. COUNTY SEPTIC PERMIT #: SEPT-9232, ISSUED 05/09/2025
10.CONTRACTOR: TALLY HO CONSTRUCTION, 970 625 0208, "jeff@tallyhoconstruction.com"
NOTE: ALL CHAMBERS IN EACH TRENCH MUST BE INSTALLED ON
LEVEL GRADE OVER SCARIFIED SOIL ABSORPTIVE SURFACE.
MAXIMUM DEPTH OF TRENCHES NOT TO EXCEED 36" BELOW
PROPOSED SURFACE GRADES. INLET AND END CAPS ARE TO BE
INSTALLED ON EACH END CHAMBER ROW. INSTALL A 4" VERTICAL
INSPECTION PORT RISER FROM THE MOLDED PENETRATION PORT ON
EACH CHAMBER END CAP OR EACH END CHAMBER IN THE TRENCH.
BACKFILL WITH SCREENED
ONSITE SOILS FREE OF ROCKS IN
EXCESS OF 3" DIAMETER OR USE 3/4"
TO 1.5' SCREENED ROCK
CROWN FIELD TRENCH TO
DIVERT SURFACE WATER
FILTER FABRIC
4' MIN
LEACHING
CHAMBER
12"
6"
N.T.S.
BACKFILL LAYER NATURAL ONSITE
SOILS FREE OF ROCKS
4" PVC INLET PORT
IN END CAP
SCARIFY/TILL BOTTOM SURFACE TO A
DEPTH OF 3"
NATIVE, YARD OR LANDSCAPED
SURFACE
N.T.S.
COMPACTED SUBGRADE
SUITABLE BACKFILL OR
CLASS 6 ROAD BASE
6" MIN.
4" MIN.
6" MIN.
4"4"
4" DISTRIBUTION
GRAVITY LINE
FROM SEPTIC TANK
INVERT IN
N.T.S.
BAFFLE
COMPACTED SUBGRADE
8" AGREGATE BASE COURSE
RISER SECTION
DISTRIBUTION BOX LID
AT GROUND SURFACE
EXCAVATED MATERIAL COMPACTED
TO 90% STANDARD PROCTOR
REVEGATATION
TOPSOIL LAYER
UNDISTURBED EARTH
SILTY LOAM SOIL.
YTN
N.T.S.
4" EFFLUENT PIPE FROM
DISTRIBUTION BOX
4" INSPECTION PORT RISER
6" VALVE BOX
QUICK-4 INFILTRATOR
OR EQUAL BIO DIFFUSER
CHAMBER
QUICK-4 INFILTRATOR
END CAP
EXTEND 4" RISER PIPE
MIN. 3" THROUGH END
CAP OR CHAMBER PRE
FORMED PENETRATION
SECURE WITH SCREWS
THROUGH PENETRATION
FLANGE INTO PIPE CAP
6" VALVE BOX
CONNECT INDIVIDUAL 4" DISTRIBUTION PIPE
TO HEAD OF EACH CHAMBER TRENCH END CAP
(TYPICAL EACH TRENCH)
03-16-26
3/16/2026