HomeMy WebLinkAboutSubsurface Investigation and OWTS Design 10.08.16fitt
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33 Four lryheel Drive Rd
Carbondole, CO 8ló23
9rù309.5t5t
October 8, 2016 Project No. C1233
Jeff Klamer
iklarner@earthlink. net
Subsurface lnvestigation and Onsite Wastewater Treatment System Design
2-Bedroom Residence
TBD CR 117
Garfield County, Colorado
Jeff
ALL SERVICE septic, LLC performed a subsurface investigation and completed an onsite wastewater
treatment system (OWTS) design for the subject residence. The 3.14-acre property ís located of
Glenwood Springs, in an area where OWTSs and wells are necessary.
Legal Description: Section: 15 Township: 7 Range: 89 Subdivision: TRAUL SECOND AMENDED
EXEMPTION PARCEL A AS PER SECOND AMENDED TRAUL EXEMPTION, PARCELS A AND B
PLAT RECEPTION # 861514
Parcel lD: 2395-1 54-00-01 4
SITE CONDITIONS
The property is currently undeveloped, with the exception of fencing and open wooden structures for
livestock on the southern portion of the properly. A 2-bedroom cabin and bam with plumbing is proposed
on the northern portion of the property.
This site is extremely wet with drainage frorn above during Spring runoff, ín addition to being in close
proximity to Four Mile Creek. A minimum setback of 50-feet will be maintained to Four Mile Creek.
Drainage on the property will be managed by a culvert to the north of the proposed soil treatment area
(STA). This culvert is included in the site planning documents from SGM. The pump line crossing this
ditch must be properly encased at least 10-feet on each side of the crossing. See W4.0/3 Encasement
Detail.
The residence and barn will be served by a private well. The well will be located at least 50-feet from the
proposed septic tank and at least 1O0-feet from the proposed STA.
The proposed area of the STA will be in the lower lying area of the propefi, between Test Pits #2 and
#3. While we preferred the higher elevatíon in the area of Test Pit#A, the future relocation of the road
will likely impact grading and drainage in that area.
The proposed STA location has an approximate 5 to I percent slope to the northeast toward Four Mile
Creek. Native grasses cover the proposed STA.
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SUBSURFACE
The subsurhce was investigated on July 14, 2016 (Test Pits #1 and f2l and July 21 , 2t16 (Test Pits #3 and
tl4) by digging fuur soil profile test pit excavations (Test Pib). A visual and tactile soil analysis was completed
by Carla Ostberg at the time of excavation.l
The materials enæuntered in Test Pit #1 consisted of very dark brown, moist loam to 6-feet, underlain by
reddish brown, very moist, clay loam to a maximum depth explored of 8-feet- Red and gold mottling was
observed at approximately 4-feet below grade. We estimate high seasonal groundwater in this area at
approximately 4-feet below grade.
Materials encountered in Test Pit #2 were similar to those encountered in Test Pit #1.
The materials encountered Test Pit #3 consisted of medium brown, moist, loam with cobbles 6 to 18-
inches in diameter to a maximum depth explored of 4.S-feet, Mottling was observed at approximately
2.5-feet below grade. We estimate high seasonal groundwater in this area at approximately 2.5-feet
below grade.
The materials encountered in Test Pit #4 consisted of dark brown, moist, topsoil to 4-feet, underlain by
very dark brown, moist, topsoil to 4-feet, underlain by very dark brown, moist, clay loam to 6-feet,
underlain by light brown, moist, sandy loam to a maximum depth explored of 7.5-feet. We estimate high
seasonalgroundwater at 7.S-feet in this area.
STA sizing is based on Soil Type 2, Loam (consistent with findings in Test Pit #3)" An unlined sand filter
with a minimum of 2-feet of sand filter material will be utilized, allowing for Treatment Level 3 (Ï13) long
term acceptance rates (LTARs). Given the Clay Loam observed in other areas of the property, we are
using a slightly more conservative LTAR of 0.9 gallons per squere foot to design the OWTS, in
conesponding to TL2 for Soil Type 2.
' Carla Ostberg holds a Certificate of Attendance and Examination from t¡e CPOWMsual and Tactile
Evaluation of Soils Tnaining.
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DESIGN SPECIFICATIONS
Desiqn Calculations:
Average Design Flow = 75 GPD x 2 people/bedroom x 2 bedrooms) = 300 GPD
LTAR = 0.9 GPD/SF fl-L2, SoilType 2, unlined sand filterwith min' 2' sand)
300 GPD / 0.9 GPD/SF = 333 SF
12' x28' mounded sand filter
The OWTS design is based on 2-bedrooms. Plumbing in the barn will be auxiliary use to the residence.
An average daily wastewater flow of 300 GPD will be used'
The system installation will include a 115}gailon, two-compartment concrete septic tank with an
Orenco@ Biotube Pump Vault and an Orenco@ pump in the second comparünent of the septic tank. The
floats should be set to dose approximately 80 gallons each pump cycle. The control panel for the pump
must be located within line of sight of ûre septic hnk. We recommend Valley Precast out of Buena Vista be
contracted for start up of the pumping system,
The location of the septic tank must be detennined by elevation of the sewer lines exiting the structures.
This office must be contacted upon determination of the deeired location of the septic tank. At
that time, we will verify proper pümp speeification based on elevation of the septic tank installation,
elevation of the sand filter installation, and distance fom the septic tank to the STA.
Effiuent will be pressure dosed through a 1.Sìnch dianeter pump line to a mounded, 12' x 28' unlined sand
filter. The excavation ficr the sand filter will begin between native grade and 1*foot below native grade to
achieve a level base for the sand filter. The mound will consist of a minimum of 2-feet of sand filter material.
Sand filter material must be clean, coarse sand, all passing a screen having four meshes ûo he inch. The
sand must have an effective size between 0.25 and 0.60 mm. The uniformity coefñcient must be 4.0 or less.
Material meeting ASTM 33, for concrete sand, with one percent or less fines passing 200 mesh sieve may
be used.
Pipes used to disperse the effuent must be sunounded by washed coarse screened gravel or crushed
stóne. All of the gravel or stone must pass aT'/rtnch screen and must be retained on a %-inch screen. The
manifold must bé 1.5-inches in diameter. Laterals must be 1.5-inches in diameter with 5/32-inch diameter
orifice holes facing down, spaced 3-feet on aenter. Laterals will be separated by 3-feet. Each 1.5-inch
diameter lateral must end in a sweeping ell facing up with a ball valve for flushing. A soil separation f.abric
should be placed over the gravel layer followed by approxinnately 1*foot of topsoil or other suibble soil able
to support vegetative growlft.
The mound must have a minimum 3:1 slope (horizontal:vertical); therefore, the basal area will extend
approximately 9-feet beyond the sand filter on all sides. Soils in the sloped perimeter areas of the mound
must be welf draining and able to support vegetative grorarth. Thb soil rnust be apprcved by this ofñce
prior to installation. The mound must be crowned in a manner tc promote drainage off of the STA.
The component manufacturers are $pical of applications used by contractors and engineers in this area.
Altematives may be considered or recommended by contacting our office. Construction must be
according to Garfield County On-Site Wastewater Treatment System Regulations, the OIffTS Permit
provided by Garfield County Building Department, and this design'
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REVEGETATION REQUIREMENTS
An adequate layer of good qual¡ty 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 initation 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 INFORI'ATION ANÐ IIIAINTENANCE
The property owrìer shall be responsible Ícr he operation and maintenance of each OWTS servicing the
property The property owner is responsible for maintaining service contracts for manutactured units,
altemating STAs, and any other components needing maintenance.
Geo-fabrics or plastics should not be used over the absorption area. No heavy equipment, machinery, or
materials should be placed on backfilled STAs. Livestock should not graze on the STA. Plumbing fixtures
should be checked to ensure that no additionalwater is being discharyed to OWTS. For example, a running
toilet or leaky Þucet can discharge hundreds of gallons of water a day and harm a STA.
lf an efiuent filter or screen has been installed in the OWTS, we recommend this filter or screen be cleaned
annually, or as needed. lf 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 nonÐiodegradable materials should not
be placed into the OWTS. Grease should not be plaæd in household drains. Loading from a water sofrener
should not be discharged into the OWTS. No hazardous wastes should be directed into the OWTS.
Mechanical room draíns should not discharge into the OWTS. The OWTS is engineered for domestic waste
only.
ADDITIONAL CONSTRUCTION NOTES
lf 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 condítions 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-ínch.
INSTALLATION OBSERVAT|ONS
ALL SERVICE septic, LLC must view the OWTS during construction. The OWTS observation should be
performed before backfill, after placenrent of OWTS components. Septic tanks, distribution devices,
pumps, dosing siphons, and other plumbing, as applicable, must also be observed. ALL SERVICE septic,
LLC should be notified 48 hours in advance to obserue the installation.
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LIMITS:
The design is based on information submitted. lf soil conditions encountered are different from conditions
described in report, ALL SERVICE septic, LLC 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
requiiements and regulations of the county in which they are working. Licensing of Systems Contractors
may be required by county regulation.
Please call with questions.
Sincerely,
ALL SERVICE septic, LLC
Reviewed By:(rrr[& Ltstbr.uE .:,ù\
Carla Ostberg, MPH, REHS
Richard H. Petz,
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CONJUNCTION WITH DESIGN
LETTER DATED 10108/16
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Klarner Residence
TBD CR 117
Garff eld County, Colôrâdo
Prorect Numbon Cí233 Drawn ANG
Date: 10/08/16
Designed By:
Rov¡ewod By:
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33 FourWheel Orlve Road
Carbondâle, Colorado 81 623
Phoné 970.309.5259
carla@allserylcsæptic.com
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Carbondale, Colorado 81ô23
Phone 970.309.5259
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Klarner Residence
TBD CR 1'17
Garfl eld County, Colorado
Pþiect Number: Cl 233
Date: 10i08i16 I
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Reviewed By: RHPI
DÊwn Bv: ANG I Sheet 2 of 5
12'x 28' U¡{LINED SAND FILTERMOUND WIÏH 2-FEET SAND3 ROWS OF 1.5" DtA SCH-40 PVCLATERALS WITH 5/32'DIAORIFICES FACING DOWN AT 3'O.C.END EACH LATERAL IN A90' LONGSWEEPING ELL FACING UP WITH ABALL VALVE IN A VALVE BOXACCESSIBLE AT GRADESCH-40 PUMP LINEDRAINBACK TO PUMP TANK)Il--12'FROM SAND FILTERFORMIN 3:1I sLoPEI1-5" DIA SCH-40 LEVEL MANIFOLDINSPECTION PORT AT EACHCORNER OF EACH MOUND/ISTA PLANBASAL AREAvCROWN TOPSOIL FOR DRAINAGEPORI AT EACH1.5" DIA SCH.4O PVC LATERALSwlTH 5/32" DIA ORIFICE HOLESFACING DOWN AT 3 O.C.CORNERSEPARATION FABRIC ON GRAVELGRAVEL FILTER MEDIANATIVE GRADEffiSAND FILTER MAERIASIEVÊ %PASSINGI 1oo4 95n00I 80i10016 45/85æ 25/6050 15/60100 014h0 0t2TOPSOILw3.0Date: tO/O8/16 IOesigne¿ gv: CAOIRevbwed By: RHPIDrawn Bv:ANG IShæt 3 of 5Klamer ResidenceTBD CR 117Garfield County, Colo€doPrcjed Numben C1æ3ilt$[tllff ,, ,'33 Four Whæl Driw RædCarbondale, ColoEdo 81623Phone 970.309-5259carla@allseMææptic.æm
DESIGN2.BEDROOM RESIDENCE + BARN WITH PLUMBING (AUXILIARY USE)(75 GAL/PERSON/DAY x 2 PERSONS/BEDROOM x 2 BEDROOMS)WASTEWATER FLOW = 300 GALLONSSLIP.ON PVC CAPDO NOT GLUESLIP-ON PVC CAPDO NOT GLUESPRINKLER VALVEBOX AT GRADETANK300 cPD x 48 HOUR RETENTION TIME = MlN. 1000 GALLONSUSE IOOO-GALLON, TWO-COMPARTMENT CONCRETE SEPTIG TANKWITH ORENCO PUMPING SYSTEM IN 2NÞ COMPfNSULATED COPPERTRACERWIREFINISHED GRADEFINISHED GRADE4" DIAINSPECTION PIPESOIL TREATMENT AREA (STA):LONG TERM ACCEPTANCE RATË (LTAR) - 0.9 GAU SQ FTCALCULATED STA = Q/LTAR = 300 / 0.9 = 333 SFMOUNDED SAND FILTER, 2'SAND DEPTH12'X 28' INFILTRATIVE AREA4" DIA SDR-35SEWËR LINE1/4" DIA HOLË DRILLEDINTO TWO SIDES OF PIPEFOR VENTILATION(BELOW SLIP ON CAP)STA FILMEDIATO TANKHOUSE1O'DIA VALVE BOXWITH SECURED LIDDIA SCH 40END CAP MUST BEGLUED OR SECUREDIN A WATERTIGHTFASHION WITHUNDERGROUNDSEALANT.I.5' PVC SLIP X MALEPIPE THREADADAPTOR W/CAPENCASEMENT PIPE40 RIGID END1.5" DIABALLVALVECAP AT EACH ENDOF PIPE1-5" DIA SCH-40 PVCLONG SWEEP 90" ELBOW.5" DIA SCH.4O SEWER LINE.HOLE DRILLED IN ENDCAP MUSÏ ONLY BELARGE ENOUGH TOALLOW SEWER LINE TOFIT THROUGHINSTALL FLUSHINGVALVE ECCENTRIC TOCENTER OF VALVEBOXMUST REST ON BOTTOM OFENCASEMENT PIPE't.5' DtA SCH-40 PVCSUSPENDED LATERAL/â ENCASEMENT DETAIL\7 Mþ$eDate: 10/08/16 IIDesisnecqÊ ceol W4.0Reviewèd By: RHPIDrawn Bv: ANG I s¡*t ¿ or sKlamer ResidenceTBD CR'117Garñeld County, Colo€doPþjêc¡ Numb€r C12æ33 Four Wheel Drive R@dCarbondale, Cdo€do 81 623Phone 970.309-5259carla@allserviGêpticffif,tL$ilrffi