HomeMy WebLinkAboutDesign.pdfAugust 24, 2012 Project No. C1053 Mark Kisker Mkisker1@hotmail.com Subsurface Investigation and Onsite Wastewater Treatment System Design 3-Bedroom Residence 1224 CR 106 Garfield County,
Colorado Septic Permit 8-13-2941 Mark, ALL SERVICE septic, LLC performed a subsurface investigation and an onsite wastewater treatment system (OWTS) design for the subject residence.
The property is located outside of Carbondale, in an area where OWTSs are necessary. SITE CONDITIONS A 3-bedroom, single-family residence presently exists and is utilizing an existing
OWTS on the neighboring property with a legal easement. The OWTS is experiencing problems and needs to be replaced. The OWTS is likely 40+ years old and consists of a concrete septic
tank and approximately 10-foot x 64-foot pipe and gravel system located on Lot 28, both of which will be abandoned. The residence is served by the Town of Carbondale community water
system; however there are homes in the neighborhood with private wells. Lot 28 currently has a well that is located approximately 60-feet from the existing absorption area. There are
open irrigation ditches that run along both the east and west property boundaries. SUBSURFACE The subsurface was investigated by digging one 7-foot profile pit and taking a soil sample
from approximately 3.5-feet below grade. A gradation analysis was run by HP Geotech and results are detailed in a report dated August 22, 2013, Job 113 064R. All ditches were running
at the time of the profile pit excavation. The materials encountered in the profile pit consisted of dark brown, very moist, gravelly sandy loam to 3.5-feet, underlain by brown, moist,
very gravelly sandy loam with cobbles averaging 12-inches in diameter to a maximum depth explored of 7.0-feet. No bedrock or groundwater was encountered. The soil was very moist due
to heavy irrigation in the yard area. Soils in the upper 3.5-feet would be classified as a Medium Gravelly Sandy Loam with a long term acceptance rate (LTAR) of 0.9 gal/sq. ft and the
soils below 3.5-feet become more sandy and gravelly with a classification of gravelly fine sand and a LTAR of 1.2 gal/sq. ft. An average LTAR of 1.0 gal/sq. ft will be used to design
the OWTS.
Page 2 August 20, 2013 Profile Pit DESIGN SPECIFICATIONS The OWTS design is based on 3-bedrooms. An average daily wastewater flow of 450 GPD will be used. The installation must include
a 1000-gallon two-compartment Norwesco® septic tank. Manufacturer recommendations for installation must be followed. Other tank alternatives may be considered. The drywell will be located
in the driveway with dimensions of 14-feet x 15-feet x 8-feet deep with four 4-foot concrete perforated risers. The drywell must extend at least 8-feet below the inlet pipe. A minimum
of two feet of cover and geotextile fabic is required over the drywell (see W2.0 details). The drywell will consist of clean, graded rock ranging from ½” to 2 ½” in diameter. The rock
will extend from the bottom of the well to at least 2” above the inlet pipe. The sidewalls of the drywell will be scarified. A covering of heavy duty geotextile fabric will be placed
over the aggregate, followed by 1-foot of road base and another layer of heavy duty geotextile fabric and another foot of gravel. The backfill material shall be graded to deflect precipitation
and surface drainage. While the drywell is designed to withstand vehicle traffic, no heavy commercial vehicles including but not limited to dump trucks, concrete trucks, pump trucks,
and busses should drive over the drywell. An additional profile pit should be excavated prior to installation of the drywell to a depth of approximately 14-feet, assuming the inlet of
the drywell at 2-feet below grade. This must be done to confirm 4-feet of suitable soil beneath the drywell. This office must be contacted to view excavation of this pit. Where the sewer
line crosses the water line, the sewer line should be encased on 10-feet of each side of the crossing. The pipe shall be encased with Schedule 40 pipe with rigid end caps glued or secured
in a watertight fashion to the ends of the encasement pipe. The ditch running to the east of the drywell must be lined or a culvert installed within 50-feet of the drywell.
Page 3 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 Sewage Disposal System (ISDS) Regulations, the ISDS Permit provided by Garfield County Building Department, and this design. 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 absorption systems, and any other components needing maintenance. No heavy equipment, machinery, or materials should be placed on
backfilled absorption area. Livestock should not graze on the absorption area. 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 an absorption area. 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, air release valves and weep holes should be installed
to allow pump lines to drain to minimize risk of freezing. Excavation equipment must not drive in excavation of the absorption area due to the potential to compact soil. Extensions should
be placed on all septic tank components to allow access to them from existing grade. INSTALLATION OBSERVATIONS ALL SERVICE septic, LLC 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. ALL SERVICE septic, LLC should be notified 48 hours in advance to observe the installation. LIMITS: The design is based on information submitted. If 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 installer should have documented and demonstrated knowledge of the requirements and regulations of the county
in which they are working.
Page 4 Please call with questions. Sincerely, ALL SERVICE septic, LLC Reviewed By: Carla Ostberg, MPH, REHS
~tech HEPWORTH· PAWLAK GEOTECHNICAL August 22, 2013 CBO Inc. Attn: Carla Ostberg 33 Four Wheel Drive Road Carbondale, Colorado 81623 carla.ostberg@gmail.com I l cpworll,.PilWlilk G('(Iicdllli':JI,
InC", 5020 Counly RIM!I 154 GICIIWo.'lHli Springs. C.,ltlrtHIlI 81601 Phone: 970-945-7988 Fax: 970-945-845.:t. Jj mai l: l'pgco(i(Jh pgcol{'.:b.colll Job No. 113 064R Subject: Laboratory
Test Results, 1224 County Road 106 Garfield County, Colorado Dear Mrs. Ostberg: As requested, Hepworth-Pawlak Geotechnical, Inc. performed gradation analysis on a sample delivered to
our laboratory by you. The services were performed in accordance with our agreement for professional engineering services to you, dated March 20, 2013. Results of the gradation analysis
performed on the sample are presented on Figure I. The USDA Soil Texture Classification is Sandy Loam. If you have any questions or need further assistance, please ca\l our office. Sincerely,
H -PAWLAK GEOTECHNICAL, INC. Louis E. E\ler LEElksw attachment Figure 1 -USDA Soil Texture Gradation Test Results Puker 303·841.7119 . Colorado Springs 719·633·5562 . Silverthorne 970·468·1989
0 z"" ~ '""" I--Z "U" "a'".". I HYDROMETER ANALYSIS I SIEVE ANALYSIS I. HR TIME READINGS I 24 HR. 7 U.S. STANDARD SERIES I o 45 MIN. 15 MIN. 60MIN19MIN.4 MIN. 1 MIN. #200 #100 #50 #30
#16 #10 #4 10 20 30 40 50 60 70 80 90 100 .001 .002 .005 .009 .019 CLAY I GRAVEL 21 % .037 .074 .150 .300 .600 1.18 2.36 4.75 DIAMETER OF PARTICLES IN MILLIMETERS SAND -% SILT -% J CLEAR
SQUARE OPENINGS I 3/8' 3/4" 1 1/2" 3" 5" 6" 8' 100 90 80 70 60 50 40 30 20 10 o 9.5 19.0 37.5 76.2 152 203 12.5 127 coaeL£S CLAY -% USDA SOIL TYPE: Sandy Loam FROM: 1224 County Road
106 (,!) Z ieini ..: a.. I--Z U"" '"a".". 113064R C~:h USDA GRADATION TEST RESULTS Figure 1 HePworth-Pawlak Geotechnical
N ~ 0' 10' 20' Scale: 1" = 20'-0" EXISTING CONCRETE TANK TO BE ABANDONED SOPRIS AVENUE EXISTING ABSORPTION ~ AREA TO BE ABANDONED -------THE LOCATION OF EXISTING AND PROPOSED IMPROVEMENTS
SHOWN ARE NOT THE RESULT OF A PROPERTY SURVEY. THE LOCATIONS ARE APPROXIMATE. IT IS THE HOMEOWNERS DUTY TO ENSURE ALL CONSTRUCTION AND IMPROVEMENTS LOCATIONS ARE ACCURATE. ALL SETBACK
DISTANCES SHOULD BE CONFIRMED PRIOR TO EXCAVATION. WELLO 4" SDR-35 SEWER LINE 100' WITH CLEANOUT (SLOPE 2% TO TANK) :>-s c . :>-'S c PROPERTY LINE 1000-GALLON, II \ TWO-COMPARTMENT 4
_I SEPTIC TANK WITH EFFLUENT FILTER ENCASE SEWER LINE WHERE IT CROSSES WATER LINE 4" SCH40 SEWER LINE 15' x 14' DRYWELL UNDER GRAVEL DRIVE LINE DITCH --<0 .o... . Cl o« 0::: ~ Z o=>
() o WATER \E 3-BEDROOM RESIDENCE WITHIN 50' OF ~ DRYWELL CD SITE PLAN ... M ' ~ .. Hll ~(~flt( P.O. Box 2844 Glenwood Springs, Colorado 81602 Phone 970.618.5033 Fax 303.216.2796 Kisker
Residence 1224 County Road 106 Garfield County, Colorado Project Number: C1053 Date: 08/24/13 I () ICi Designed By: CBO I W 1 .0 Checked By: RP Drawn By: ANG Sheet 1 of 3
PLAN VIEW SWALE OR BERM TO DIVERT SURFACE RUNOFF 4"PVCINLET LINE FROM /SEPTICTANK~ MANHOLE COVER---------DRYWELL DRAIN FIELD SPECIFICATIONS DISPERSAL GRAVEL SHOULD 14' BE 1/2" TO 2 1/2"
,.-----SIDES OF EXCAVATION ~------~--~----~~----------~--~~-OBSERVATION PIPE WITH PVC CAP CROSS SECTION CONCRETE LID -----------------------. WITH MANHOLE COVER GRAVEL DRIVE ~--GRAVEL
DRIVEWAY ~-,-~---HEAVYDUTY INLET FROM SEPTIC TANK EXTENT OF 8' EXCAVATION -----L---!---.:._---2<.J. .~_-=~=======:::!_==:::::::....~---1..-----J ~-----+----15'---------~ PLACE AN 8-INCH
BED OF GRAVEL PRIOR TO PLACING CONCRETE RINGS FOR STABILITY o DRYWELL DETAIN~;;TO SCALE P.O. Box 2844 Glenwood Springs, Colorado 81602 Phone 970.618.5033 Fax 303.216.2796 Kisker Residence
1224 County Road 106 Garfield County, Colorado Project Number: C1053 GEOTEXTILE-FABRIC DISPERSAL GRAVEL .-----SLOTTED PVC OBS. PIPE TO EXTEND TO BOTTOM OF DRYWELL 4' DIAMETER CONCRETE
PERFORATED RINGS Date: 08/24/12 Designed By: CBO Checked By: RP Drawn By: ANG W2.0 Sheet 2 of3
DESIGN 3-BEDROOM RESIDENCE (75 GAL/PERSON/DAY x 2 PERSONS/BEDROOM x 3 BEDROOMS) AVERAGE DAILY FLOW = 450 GALLONS DESIGN FLOW = Q = 1.5 x 450 = 675 GALLONS TANK: 450 x 30 HOUR RETENTION
TIME = 843 GALLONS USE 1000-GALLON, TWO-COMPARTMENT TANK ABSORPTION AREA: LONG TERM ACCEPTANCE RATE (LTAR) = 1.0 GAll SQ FT CALCULATED ABSORPTION AREA = Q/L T AR = 675 SF DRYWELL DIMENSIONS
LENGTH = 14' WIDTH = 15' DEPTH BELOW INLET = 8' 14 X 2 X 8 = 224 15 X 2 X 8 = 240 14X15=210 FINISHED GRADE ~--SLIP-ON PVC CAP DO NOT GLUE EFFLUENT LINE -4" --"""""'----\----l----I--SCHEDULE
40 OR 4" SDR SEWER LINE -35 P.V.C. 4" SCHEDULE 40 P.V.C. INSULATED COPPER TRACER WIRE MAY BE INSTALLED TO LOCATE LINE IN FUTURE o CLEANOUT DET~~~O SCALE Septic Tank with the Addition
of an Effluent Filter -1000 Gallon, 2-Comp. Concrete R ise rs~ Slope Ground Away From Rise rs •• rr~~~~=:---T===:~0= Filter Cartridge Handle Tap of tee to came to 1" from top of tank
lid (field cut to desired height) Tank Adapter (cast or bolted) Inlet Tee r-"+----+-------4---T-----1 ORENCO BRAND NAME NOT ENFORCED o TANK DETAIL NOT TO SCALE P.O. Box 2844 -* Liquid
Level Glenwood Springs, Colorado 81602 Phone 970.618.5033 Fax 303.216.2796 Vent Orifice Eff luent Di.sch arge Modulating Discha rge Orifices -++--Vau lt Inlet Ports Filter Cartridge
Eff luent Filter Kisker Residence 1224 County Road 106 Garfield County, Colorado Project Number: C1053 Revision: 08/24/12 Designed By: CBO Checked By: RP Drawn By: ANG W3.0 Sheet 3 of3