HomeMy WebLinkAboutOWTS Design ReportProposed Single-Family OWTS System
Onsite Wastewater Treatment System Design
3-BR Single-Family Residence
TBD Rapids View Lane
New Castle, CO 81,647
Parcel No. 2181-013-07 -021
Prepared for:
Jason Minasian
TBD Rapids View Lane
New Castle, CO 81647
Muyo 2025
Prepared by:
Digitally $igned
by Jeremy
Gilliam
Date:
2025.A513
12:50:41-06'00'
$Ilest Water En g i n eeri n g
.4 Environrnental Consulting Se-vices
2516 Foresight Circle #1, Grand Junction, CO 81505 Telephone: (970)241-7076
1.0 SCOPE
This report presents the findings of an On-Site Wastewater Treatment System (OWTS) design
for a proposed three-bedroom (3-BR) single-family residence at Parcel # 218l-043-07-021(TBD
Rapids View Lane) in New Castle, Colorado. The purpose of this report was to establish design
critena for a new OWTS system. The report includes an assessment of observed subsoil and
groundwater conditions, percolation test results, and the design and construction parameters for
the OWTS. The findings are based on data gathered from field percolation testing, and
engineering evaluation informed by experience with similar site conditions.
2.0 DESIGN SUMMARY
1. Encountered subsurface conditions consisted of I foot of topsoil underlain by 3 feet
of silty clay underlain by gravelly sand (<35oh rock) to the maximum depth explored
of 8 feet below ground surface (Appendix A). Groundwater was not encountered at
the time of observation to 8 feet below ground surface.
2. The average percolation result was 9.9 minutes per inch. We determined from Table
l0-1 of Garfield County's On-Site Wastewater Treatment System Regulation
(Regulations) the treatment area soil type to be Type I and used "Long Term
Acceptance Rate" (LTAR):0.80 gallons per day per square foot. .
3. The design system will utilize a new 1,000 gallon septic tank, which will discharge
effluent to four new (4) Quick 4 Plus Infiltrator trenches, each with nine (9) units, for
atotal minimum disturbed area of about 24 feetby 39 feet.
4. Design placement based on setbacks and comparison to minimum requirements,
which must be confirmed prior to installation by the licensed installation contractor
3.0 EXISTING SITE CONDITIONS
The Z.}-acre parcel located at TBD Rapids View Lane was barren lot with minimal vegetation.
The lot is relatively flat and is in a developing subdivision of single-family residences.
4.0 PROPOSED SITE IMPROVIMENTS
A proposed 3-BR single-family residence and detached plumbed garage is to be constructed. The
structures will have no below grade/basement areas. If the proposed construction is different than
what is described above, WestWater Engineering should be notified to re-evaluate the
recommendations made herein.
The new 3-BR dwelling and accessory buildings will be served by a new 1,00O-gallon septic
tank (minimum) and a total of 36 new Standard Plus Quick4Infitrator@ units configured in four
(4) trenches, each with nine (9) Q4 Plus units for a minimum 24' x 39' footprint including 4 feet
separation distance between trenches and chamber end caps (FigureB2).
5.0 SOIL INVtrSTIGATION
WestWater Engineering collected soil and percolation data on Apnl22,2025, in accordance with
the Regulations. The soil profile in the vicinity of the proposed Soil Treatment Area (STA)
shows topsoil I foot below ground surface underlain by 3 feet of silty clay underlain by gravelly
sand (<35o/o rock) to the maximum depth explored of 8 feet below ground surface. No
groundwater was encountered at the time of observation (Appendix A).
Percolation rates ranged from 13.8 to 7.3 minutes per inch (Appendix A). WestWater
Engineering finds the average percolation rate of 9.9 minutes per inch to be most applicable.
Based on the Garfield County, On-Site Wastewater Treatment System Regulations effective
Apnl2O,2023, Table l0-1, the soil type was determined as Soil Type l,Long Term Acceptance
Rate (LTAR):0.80 gallons per day per square foot which most nearly describes the condition
for this site and proposed construction.
6.0 OWTS WASTEWATER DESIGN FLOW
As per guidelines, the occupancy is 6 persons, tabulated as 2 people per bedroom for the first 3
bedroom. The design flow is 6 persons x 75 gallons per day per person : 450 gallons per day
(see Table 6-l of the Regulations).
7.0 OWTS DESIGN
Septic Tank
The minimum septic tank capacity required to service atotal of three (3) bedrooms is 1,000
gallons in accordance with Table 9-1 of the Regulations. The minimum required septic tank
volume will provide a 48-hour (Z-day) particle detention time for the wastewater flow capacity
of the proposed OWTS. The required capacity of 1,000 gallons exceeds the estimated daily
wastewater flow of 450 gallons per day (GPD) over a two-day period (450 GPD x 2 days : 900
gallons), ensuring compliance with the Regulations. The tank shall be equipped with locking or
sscured access lids to prevent unintended access.
Distribution Box
For this design, use a new distribution box (D-box) approved for use in Garfield County. Ensure
that the flow is equal between laterals by using flow equalizers in D-box and access is available
for maintenance and inspection via an approved riser assembly with locking lid.
Soil Treatment Area (STA)
Silty clay occurring atthe 3.0-foot depth interval will be used for the upper infiltrative surface
for the proposed STA (Figure B3). Maximum trench depth must not exceed 4 feet in accordance
with the Regulations. Trench excavation will remove approximately 3.0 feet of soil and upper
root mass to prepare the level surface for installing infiltrators on the receiving soil infiltrative
surface, providing secondary treatment of discharged wastewater. Soil should not be wet at the
time of excavation. Soils covering the STA must be crowned over proposed trenches or match
the existing grade so water runs off and is not ponded over any area of the STA. Prior to
backfilling the final soil cover, a pervious soil barrier of non-woven geotextile fabric (2 ozlyd2
minimum) or similar pervious mateial shall be installed over the STA to prohibit soil intrusion.
All setback distances in accordance with the Regulations are applicable to septic system
installation.
The following design calculations propose to discharge septic tank effluent to four (a) Quicka
Plus Infiltratortrenches, each with nine (9) units, for atotal minimum disturbed area of about24
feet by 39 feet. A total of 36 Quick 4 Standard Plus Infiltrator units will be installed in the four-
trench configuration, which is generally oriented east to west. It should be noted that other
manufacturers of infiltrators can be used, but use of alternative systcm components will rcquirc
verification by the Engineer to determine conformance with design requirements for this system.
Desian FlowSTA= L xMethodxMedia (1)
(2)
Where:
STA:
f)esign Flow:
LTAR:
Method:
Media:
Total surface area required to effectively discharge sewage effluent
Estimated volume of wastewater per day
Long-Term Acceptance Rate of soil treatment area
Method of effluent application and type of soil treatment area
Type of distribution media
STA
Total chambers - ctlamber Area
Where
Chamber Area: The County and State approved bottom chamber area for Quick 4 Plus
Standard Infiltrator IJnit, 12 ft2
rf
Per Regulations Table 6-1,
Design Flow : 450 Gallons/Day
Long Term Acceptance Rate (LTAR) review of Regulations Table 10-1,
LTAR: 0.80 Gallons/Day Eoot2
Type of application is chosen as gravity fed trench system, per Regulations Table 10-2,
Method: 1.0
Distribution media is chosen as chambers? per Regulation Table l0-3,
Media:0.7
Then,
450
STA - mt L.O xo.7
The minimum STA Area is 393.75 ft2
393.75Total Chambers = T
(1)
(2)
The minimum number of Quick 4 Plus Infiltrators is 32.8. As 32.8 Infiltrators cannot be evenly
divided between four trenches to ensure equal effluent flow, the design increases the number of
Quick 4 Plus Infiltrators to a total of 36, divided between four trenches with nine (9) units each.
8.0 SYSTEMINSTALLATIONREOUIREMENTS
The installer should confirm the feasibility of gravity discharge of sewage effluent from the
proposed residence to the STA. If field measurements do not confirm the design assumptions for
gravity discharge of sewage effluent from the proposed residence to the STA, or if the installer
does not consider the above design assumptions practical, please contact the design engineer to
address any design modifications necessary for the effective operation of the OWTS.
The installer must also confirm all setbacks from property lines, building envelopes, and existing
easements aremaintained. Additionally, any unknown utility lines, easements, or other adverse
conditions disclosed during construction must maintain at the required minimum setbacks.
All sewer pipe couplings must be completed with primed and glued or bell and spigot joints
using 4-inch SDR 35 PVC pipe. Schedule 40 PVC 4-inch pipe with a minimum 1-foot soil cover
must be used if pipe is installed in a vehicular iraffrc crossing. Drain-waste-vent @WV) rated
Schedule 40 PVC pipe is called out for crossings but may also be used instead of SDR 35 PVC
pipe.
Building sewer pipe must be installed at a slope between %-inch and V+-inch per foot slope (1 to
2o/o), preferably using lhe V+-inch per foot slope as recommended by the International Plumbing
Code (IPC) as administered by the County. Fittings shall be sweep 90-degree curyes or two (2)
45-degree elbows at all influent pipe turns. Fittings must be DWV for schedule 40 PVC pipe.
Two-way clean-outs are required between dwelling and tank and beyond tank where pipe lengths
exceed 100-feet from tank to STA and at all pipe bends greater than 45 degrees. Clean outs shall
be installed with screw caps at finished gradewith a protective housing for easy access by
homeowner.
The installer must adhere to minimum and maximum depth requirements for the STA. System
components must be placed on native soils or re-stabilized soils, as specified by the engineered
OWTS reports, in excavated areas.
The owner will ultimately be responsible for septic system maintenance including pumping the
septic tank once every 2-3 yews and cleaning the effluent filter (if applicable) every 6 months.
9.0 SYSTEM INSPECTION
WestWater Engineering is responsible for inspecting the OWTS to ensure construction conforms
to the design plan and meets all aspects of County Regulations, including:
o Inspect and measure the system before backfilling, including piping and septic system
components.
o Complete the as-built drawing of the system and submit it to Garfield County for
approval.
o Reviewing and approving any submitted changes necessary for installation of the OWTS
as deemed necessary by the owner or their contractor. Any system changes installed by
the owner/contractor that were not approved by Engineer arelhe responsibility of the
ownef.
1O.O DESIGNLIMITATIONS
The OWTS design is based on site-specific soil conditions and percolation data collected in the
vicinity of the proposed STA and local experience of designing OWTSs in Colorado. The design
is only valid for the proposed new OWTS serving the proposed 3-BR dwelling at the referenced
location provided in this report. WestWater Engineering assumes no liability for inaccurate
information or conditions that vary from the design assumptions listed above. Additionally,
WestWater Engineering is not responsible for the quality of work for any person(s) or entity
performing or supporting construction activities relating to the project or for any contractor's
failure to furnish or perform its work in accordance with the plans, specifications or the
Regulations. The owner/contractor is to notifr WestWater Engineering and/or Garfield County
immediately if actual site conditions differ from those described herein.
Please do not hesitate to contact us if you have any questions regarding this report.
APPEIIDIX A
SOILS AI\D PERCOLATION DATA
Q\lest Water E n g i n ee ri n g
e consulting Engineers & Scientisis
2516 FORESTGHT CIRCLE, #1 GBAND JUNCTION, COTORADO 8X505 {970} ?4? -7075 - FAX (970} 24t-7097
SOILS AND PERCOLATION REPORT
Date May 1,2025
Consultant:Curtis Beckel, EIT
WestWater Engineering
2516 Foresight Circle #1
Grand Junction, CO 81505
(e70) 24t-7076
Client:Jason Minasian
Land Parcel: TBD Rapids View Lane, New Castle, CO 87647
2r8t-043-07-021
SECTIONl_SOILSLOG
One test pit was evaluated at the empty 2.}-acre parcel for an onsite wastewater treatment system
(OWTS) that will serve a new proposed 3-BR single-family dwelling located at TBD Rapids
View Lane, New Castle, Colorado.
The Test Pit (TP-1) was located approximately 75 south of the north property line and 45 feel
east of the west property line (see Figure Bl of the Design Report). The benched test pit was in
general conformance with Figure Al with a maximum depth of 8 feet (96 inches) below ground
surface.
The visual description of the profile soils, with ASTM D 2488 used for guidance, is summarized
below and in Table I - Log of Exploratory Test Pit.
AI
Table 1 - Log of Exploratory Test Pit
TBD Rapids ViewLane
New Castle, Colorado
Location: See Figure B-l Date:4-22-25
Depth
(f0 Description Interval Notes
0 Stifq dry, tan and grey, low plasticity, silty CLAY 0-1'Topsoil
Stifq dry, brown,low plasticity, silty CLAY
t-4'
Dense, dry, grey and brown, gravelly SAND with
cobble (Alluvium)
Total Depth: 8 feet below ground surface
4-8',5
Subsurface conditions encountered in the test pit consisted of one foot of silty clay topsoil
underlain by three feet of silty clay underlain by gravelly sand to the maximum depth explored of
8 feet below ground surface. The silty clay topsoil was stifl dry, tan and grey. The silty clay was
stiff, dry and brown. The gravelly sand was dense, dry, grey and brown with maximum grain size
neanng 3 inch (cobble) indicative of Alluvium deposit (<3s%rock). No groundwater was
encountered at the time of observation.
A2
SECTION 2 _ PERCOLATION TEST
Three standard percolation rate tests were performed at the site referenced.
TP-l contained 3 percolation test holes, approximately I foot in depth each, herein referred to as
P-l,P-2 and P-3. P-l was located in TP-l at ground surface in silty clay topsoil.P-z was located
in TP-l at2 feetbelow ground sur ce in silty clay. P-3 was located in TP-1 at 4 feet below
ground surface in gravelly sand. All percolation holes were saturated}4 hours before testing.
The percolation rates encountered were 13.8 minutes per inch in silty clay topsoil at the ground
surface, 8.5 minutes per inch in a stratum of silty clay at2 feet below ground surface, andT .3
minutes per inch in silty sandy clay at 4 feet below ground surface. WestWater Engineering finds
the average percolation rate of 9.9 most nearly describes the behavior of the soils at the expected
infiltration elevation of 3 feet below ground surface.
A3
PERCOLATION TEST RESULTS
TBD Rapids View Lane,New Castle
SATURATION AND PREPARATION
DATE: 4-21-2025
PERCOLATION TEST
DATE: 4-22-2025
HOLE REFERENCE NO: P-l
PERC HOLE DEPTH: Surface
TIME INTERVALS: 10 minutes
AVERAGE PERCOLATION RATE (MIN/INCH)13.8
TIME AT
START OF
INTERVAL
START OF
INTERVAL
(rNcH)
END OF
INTERVAL
(rNcH)
WATER DEPTH
CTIANGE
(rNCH)
PERCOLATION
RATE
(MIN/rNCr{)
0755 0 1 I 10
0805 1 2 I 10
0815 2 3,5 1.5 6.66
0825 ?5 4.75 1.25 8
0835 0 1.5 1.5 6.66
0845 1.5 2.5 I 10
0855 2.5 3.5 1 10
0905 3.5 4.25 0.75 t3.33
0915 4.25 5 0.75 13.33
0925 0 0.75 0.75 13.33
0935 0.75 1.5 0.5 20
0945 1.25 1.75 0.5 20
0955 1.75 2.25 0.5 20
1005 2.25 2.75 0.5 20
1015 2.75 3.25 0.5 20
1025 3.25 3.75 0.5 20
A4
HOLE REFERENCE NO: P-2
PERC HOLE DEPTH: 2feet
TIME INTERVALS: l0 minutes
TIME AT
START OF
INTERVAL
START OF
INTERVAL
(rNCH)
END OF
INTERVAL
0NCH)
WATER DEPTH
CHANGE
(rNcH)
PERCOLATION
RATE
(MrN/rNCH)
0755 0 4 4 2.5
0805 0 J J J.JJ
0815 0 -t 3 3,33
0825 ^t 5.5 2.5 4
0835 0 2.75 2.75 3.64
0845 2.75 4.75 2 5
0855 0 2 2 5
0905 2 3.5 1.5 6.66
0915 3.5 4.75 r.2s 8
0925 0 t.25 t.2s 8
0935 1.25 2 0.75 13.33
0945 )2.75 0.75 13.33
0955 2.75 3.5 0.75 13.33
1005 3,5 4.2s 0.75 13.33
1015 4.25 5 0.75 13.33
1025 5 5.5 0.5 20
AVERAGE PERCOLATION RATE (MIN/INCH)8.5
A5
HOLE REFERENCE NO: P-3
PERC HOLE DEPTH: 4 feet
TIME INTERVALS: 10 minutes
TIME AT
START OF
INTERVAL
START OF
INTERVAL
(rNCH)
END OF
INTERVAL
(INCrr)
WATER DEPTH
CHANGE
(rNCH)
PERCOLATION
RATE
(MrN/rNCH)
0755 0 6 6 r.66
0805 6 9 J 3.33
0815 0 3,5 3.5 2.86
0825 3.5 5 1.5 6.66
0835 0 J J
0845 J 4.75 1.75 5.7r
0855 0 2.s 2.5 4
0905 2.5 3.5 I 10
0915 3.5 4.25 0.75 13.33
0925 0 r.75 t.75 5.71
0935 1.75 2.75 1 10
0945 2.75 3.75 I 10
0955 3.75 4.75 I 10
1005 4.75 5.75 I 10
1015 5.75 6.75 1 10
r025 6.75 7.75 I 10
AVERAGE PERCOLATION RATE (MIN/INCH)7.3
A6
APPENDIX B
FIGURES
1
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n\ilestUUtkltA Englneering500 FIGURE 81
TBD RAPIDS VIEW I.ANE
DflSnNG OWTI| SnE PLAl,l
25 16 Foresight Chcle, #1
Grand Junstio& CO 81505
e7a)241-7076SCALE: 1":100'
100
-7
3-BR
t
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APPROXIMATE
ROXIMATE LOCATION
OF METER
OF TP-1
{t ,-
&4,V€,NEW
.
HORZ0
-45
BEND (rYP)
NEW 4" SDR 35 PVC
SEWER SERVICE
(t=+z.s L.F.t,s=2%)
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PROPOSED GAR4GE
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-wAY CLE*Nbur (rfP)NEW 2
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APPROXIMATE EXI$ING PROPERTY LINE'J- 2.0
ACRES (een OAnFIELD QOUNTY- 615;= tlrAV ZOZS)
- - : ':tt;-=--t
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GEnglnccring
25 16 Foresight Circlg #l
Grand Junction, CO 81505
FIGURE 82
TBD RAPIDS VIEW I-.ATIE
IrnnpnsFn nwTs I aY-nl lT
50
^ ^t r tll r^t
50
NEW 10" ROUND IRRIGATION
VALVE BOX AT EACH PORT
MOUNTED FLUSH WNH GROUN
NEW 4" SCH 40 P/C OBSERVATION
PORT WITH CAP (WP
'PROXIMATE EXISTING
g.o'
PLACE GEOTEKnLE OVER TNFILTRATORS (Typ)
CROWN BACKFILL OVER TRENCHES
1.0'or)
4.0'o
@
g GROUNDWATER- GREATER THAN 8.0'
TRENCH NOTE:
MA(IMUM DEPTH 4.0 FEET
MINIMUM DEPTH 3.0 FEET
INSTALI.ATION NOTES:
FOLLOW MANUFACTURERS INSTRUCTION www.infiltrotorsystems.com
SCREW PIPE TOP PORT CHAMBER FACEPHTE
SCREW FACEPTATES AND UNITS TOGETHER
INSTALL MONITORING PORTS TRENCH ENDS
ALL FOUR BED CORNERS
36 Q4 INFILTMTORS
(4) TRENcHES
(e) uNrrs EAcH TRENcH
PROVIDE LEVEL SCARIFIED SURFACE
ACROSS LENGTH OF TRENCH(S), NOTTFY
ENGTNEER IF TRENCH BOTTOM(S) ARE WEr
1)
2)
3)
4)
4.0'4.0'4.0'
TOPSOIL
3o
E
a
oz
lt
=U
eec'
FIGURE B5
owTs cRoss
A\]{estY}rEll
4Englneerlng
2516 Foresight Circle, #l
Grand Junctio4 CO 81505
(97O\241:t076
www.westwatefco.crm
SCALE 1'=5'
NN 24"A ACCESS
HATCHES WrTH LOCKTNG/
SECURE TANK LIDS
MTIVE BACKFILL COMPATED
TO 952 MSHTO T-99 *2%
OPTIMUM SOIL MOISTURE
FINISHED GRADE
OPTIONAL ORENCO
(oR EOUTVALENT)
4" EFFLUENT FILTER
NEW 4, SCH 40 PVC
SEWER UNE
(L:42.S'*, 5:-2.00%)
TO STA
DISTRIBUTION BOX
NEW 4" SCH 40
PVC SEWER LINE
NEW 4' SCH 40 ryC WYE/IEE
NEW I,OOO GALLON SEPTIC TANK
GRAVITY FLOW +
FROM DWELLING
NEW 7+" MINUS WASHED ROCK
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FIGURE 84
2516 Foresight Circle, #1
Grand Junctioru CO 81505
(910)241-7076
tvww"westwat€fco.com
(a" tncH DEPTH MINIMUM)
APPENDIX C
GARFIELD COUNTY ON.SITE WASTE WATER
TREATMENT SYSTEM REGULATIONS, TABLE
7-1 FROM THE 2023 REGULATIONDOCUMENT
CODE OF COLORADO REGULANAN
Water Quality Control Commission
SCCR 10024jt
Table 7-1 Minimum Horizontal Distances in Feet Between Gomponents of an On..Site Wastewater Treatment System lnstalled After
November 15 1973 and Water and Health lm Features
ieptic Tank,
{igher Level
freatment Unit,
)osing Tank,
/ault or Vault
3uilding Sewer or
iffluent Lines
iTA Trench, STA
led, Unlined
iand Filter, Sub-
;urface Dispersal
)ystem, Seepage
)it
-ined Sand Filter
-ined Evapo-
ranspiration Field
:r Outside of
3erm of Lined
/Vastewater Pond
5
5
5
Septic
Tank,
Higher level
treatment
Unit,
Dosing
Tank, Vault
or Privy
01
1A2
25
01
10
Dry
Gulch,
Cut
Bank,
Fiil
Area
(from
Crest)
25
50
502
503
25
Lake,
Water
Course,
lrrigation
Ditch,
Stream,
Wetland
102
25
01
10
Subsurface
Drain,
lntermittent
lrrigation
Lateral,
Drywell,
Stormwater
Structure
0101
102
10
10
10
Property
Lines,
Piped or
Lined
lrrigation
Ditch,
upslope
curtain
drain
0
10
10
51
Structure
without
basement,
crawl
space or
footing
drains
55
0
20
15
51
Structure
w/basement,
crawlspace
or footing
drains
102
56
252
102
102
Potable
Water
Supply
Line 2
60
60
502
502
100 3
Spring,
Well,1
Suction
Line,
Potable
Water
Supply
Cisterna
43
FrG. C-1
CODE OF COLORADO REGULANON
Water Quali9 Control Commission
Jnlined Sand
:ilter in SoilWith
r Percolation Rate
ilower than 60
vlinutes per lnch,
Jnlined or
)artially Lined
ivapotrans-
:iration System,
)utside of Berm
:f Unlined
Nastewater Pond,
lr System Not
Relying on STA
br Treatment
)ther than
\erosol
ilit Trench
-atrin Pit P
iystem Not
?elying on STA
br
NOTE: The minimum distances shown above must be maintained between the OWTS components and the features described. \Mrere soil, geological or other conditions warrant,
or upgrading of existing OWTS lvhere the size of lot predudes 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. Components that are not watertight should not extend into areas of the root system of nearby trees.
1 lncludes potable wells, inigation wells and monitoring wells set within a potable aquifer and infiftration galleries permitted as wells by the Division of Water Resources.
5 CCR 1002-tti)
N/A
01
Septic
Tank,
Higher level
treatment
Unit,
Dosing
Tank, Vauft
or Privy
10
Dry
Gulch,
Cut
Bank,
Fiil
Area
(from
Crest)
15
25
10
100
253
Lake,
Water
Course,
lrrigation
Ditch,
Stream,
Wetland
25
25
0
Subsurface
Drain,
lntermittent
lrrigation
Lateral,
Drywell,
Stormwater
Structure
2510
25
01
Property
Lines,
Piped or
Lined
lrrigation
Ditch,
upslope
curtain
drain
15
25
1255
Structure
without
basement,
crawl
space or
footing
drains
25
125
Structure
Wbasement,
crawlspace
or footing
drains
15252
502
142
Potable
Water
Supply
Line 2
100
100 3
Spring,
Well,1
Suction
Line,
Potable
Water
Supply
Cisterna
100
4
FIG. C-2
CODE OF COLORADO REGULANON
Water Quality Control Commission
5 CCR 100243
2 Crossings or encroachments may be permitted at the points as noted above provided that the water or wastewater conveyance pipe is encased for the minimum setback
distance on each side of the crossing. A length of pipe with a minimum Schedule 40 rating [ASTM Standard D 3034-16 (2016 version)] of sufficient diameterto easily slide over and
completely encase the conveyance must be used. Rigid end caps of at least Schedule 40 rating [ASTM Standard D 3034-16 (201 6 version)l must be glued or secured in a watertight
the bottom of the encasement pipe. The area in which the pipe passes through the end caps must be sealed with an approved underground sealant compatible with the piping used.
Other methods of encasement that provide equal protection are allowed. These methods must be reviewed and approved by the local public health agency.
3 Add eight feet additional distance for each 100 gallons per day of design flows between 1,0@ and 2,000 gallons per day, unless it can be demon$rated by a professional
required to minimize contamination as part of the Division site application and permitting process.
4 All horizontal setbacks to a potable water supply ci$em must be met unless a variance by the Board of Examiners of Water Well Construction and Pump lnstallation
11.4 of the WaterWell Construction Rules, as applicable. The minimum horizontal setback that may be granted through a variance is to 25 feet.
5 lf the structure is not used as a habitable unit, the isolation may be reduced by the local board of health to no less than 50 feet.
6. Building sewer installations shall meet the design requirements of the Colorado Plumbing Code.
45
FrG. C-3