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HomeMy WebLinkAboutOWTS DesignIG'I lfumar & Assoclates, lnc.@ Geotechnical and Materials Engineers and Environmental Scientists 5020 County Road 154 Glenwood Springs, CO 81601 phone: (970) 945-7988 fax: (970) 945-8454 email : kaglenwood@kumarusa.com An Ëmployge Owntd Gompony www'kumarusa'com Office Locations: Denver (HQ), Parker, Colorado Springs, Fort Collins, Glenwood Springs, and Summit County, Colorado ONSITE WASTEWATER TREATMENT SYSTEM DESIGN PROPOSED SHOP BUILDING ROYAL ELK RANCH corn[TY ROAD 140 (COFFEE POT ROAD) GARFIELD COUNTY' COLORADO PROJECT NO. 2l-7-342.02 AUGUST 16,2022 PREPARED FOR: ROYAL ELK RANCH C/O McARTHUR ENTERPRISES, INC ATTN: JERRY MCARTHUR P. O. BOX 1954 ED\ryARDS, COLORADO 81632 ierrv@remonov.ocm TABLE OF CONTENTS INTRODUCTION PROPOSED CONSTRUCTION SITE CONDITIONS....... SUBSURFACE CONDITIONS OWTS ANALYSIS ... DESIGN RECOMMENDATIONS .. SOIL TREATMENT AREA... OWTS COMPONENTS OWTS OPERATION AND MAINTENANCE.... OWTS HOUSEHOLD OPERATION OWTS MAINTENANCE............ OV/TS CONSTRUCTION OBSERVATION LIMITATIONS FIGURES FIGURE 1 _ OWTS SITE PLAN FIGURE 2 _ USDA GRADATION TEST RESULTS FIGURE 3 _ SOIL TREATMENT AREA CALCULATIONS FIGURE 4 - SOIL TREATMENT AREA PLAN VIEW FIGURE 5 * SOIL TREATMENT AREA CROSS SECTION ATTACHMENTS VALLEY PRECAST 1,OOO GALLON, TWO-CHAMBER SEPTIC TANK DETAIL 1- I I 1 J J 4 ...- 6 - ...- 6 - ,,..7 - ô 7- -1- Kumar & Associates, lnc.Project No. 21-7'342.02 INTRODUCTION This report provides the results of an onsite wastewater treatment system (OWTS) design for the proposed shop building to be located at Royal Elk Ranch, County Road 140 (Coffee Pot Road), Garfield County, Colorado. The project site is shown on Figure 1. The pufpose of the report is to provide design details for the OWTS in accordance with the Garfield County Environmental Health Department Onsite'Wastewater Treatment System Regulations and the Colorado Department of Public Health and Environmental Regulation #43. The services were performed in accordance with our agreement for professional services to Royal Elk Ranch dated May 12, 2A20. PROPOSED CONSTRT]CTION The proposed shop building will be a steel-frame structure with a slab-on-grade floor located on the site as shown on Figure 1. The building will be approximately 80 feet by 55 feet in plan size. The building will be used for equipment storage and will only have one bathroom facility and a washer/dryer hook-up. The soil treatment area (STA) for the OWTS will be located to the northwest of the residence as shown on Figure 1, If proposed construction is different than that described, we should be contacted to re-evaluate our design recommendations. SITE CONDITIONS The site was vacant at the time of field exploration. The terrain is generally moderately to strongly sloping down to the north. Vegetation consists of oak brush, grass and weeds. There are no visible surface water features in the vicinify of the site. The surface drainage swale shown on Figure 1 is proposed. STJBSURFACE CONDITIONS The field exploration for the O\MTS was conducted on April 20,2021. Two profile pits (Profile Pits 1 and2) were excavated with an excavator at the approximate locations shown on Figure 1 to evaluate the subsurface conditions for the planned new soil treatment area for the OWTS. The pits were logged by a representative of Kumar & Associates. Logs of the profile pits are provided below. Kumar & Associates, lnc.Project No. 21 -7 -342.02 Depth USIIA Classification 0-1'TOPSOIL; organic Loam, firm, moist, dark brown. 1 ',-8', SANDY CLAY LOAM; gravelly, moderately blocky structure, stiff, moist, light brown. a a o Dísturbed bulk sample obtainedfrom 4 to 5 feet depth. Bottom of pit @ I feet. No groundwater or redoximorphic features observed at time of pít excavation. a Log of Profile Pit I Log of Profile Pit 2 The soils encountered in profile pits, below about 1 foot of organic topsoil, consisted of gravelly Sandy Clay Loam down to the pit depths of I feet. Hydrometer and gradation analyses were performed on a disturbed bulk sample of the soils from Profile Pit 1 from 4 to 5 feet depth with the results provided on Figure 2. The tested sample (minus No.10 size sieve fraction) classifies as Sandy Loam per the USDA system. No free water was encountered in the pits nor indications of seasonal high groundwater were observed at the time of the pit excavations. Based on the subsurface conditions and laboratory testing, the soils at the STA have been classified as Type 3 per State regulations, which equates to a long-term acceptance rate (LTAR) of 0.35 gallons per square foot per day. O\üTS ANALYSIS Based on the site conditions and profile pit evaluations, the evaluated area should be suitable for a conventional infiltration disposal system. There is adequate elevation difference from the ground floor of the shop building down to the septic tank and STA for gravity flow of the sewer effluent. The STA will consist of chambers in a trench configuration based in the Sandy Clay Loam soils. The STA will be sized for four employees at the shop building and an average daily flow of 35 gallons per employee, and an LTAR of 0.35 gallons per square foot per day for the natural Sandy Clay Loam soils. The effluent will gravity flow from the shop building to the septic tank for primary treatment and then gravity flow to the STA for dispersal and final treatment. The STA will consist of two trenches with Infiltrator Quick 4 Plus Standard chambers in a serial distribution network. Depth USDA Classificatíon 0-1'TOPSOL; organic Loam, firm, moist, dark brown. 1 ',-8'SANDY CLAY LOAM: gravelly, moderately blocky structure, stiff, slightly moist, brown. a o Bottom of pit @ 8feet. No groundwater or redoximorphic features observed at time of pit excavatíon. Kumar & Assoclates, lnc.ProJect No. 21-7 -342.02 a-J- There are no known potable water supply lines in the vicinity of the proposed STA. The required setback to the potable water supply line is l0 feet from the septic tank, 5 feet from sewer and effluent lines, and 25 feet from the STA. The required setback to a spring, well or potable water supply cistem is 50 feet from the septic tank and sewer and effluent lines, and 100 feet from the STA. We should be notified for additional recommendations if these minimum setbacks cannot be met. DESIGN RECOMMENDATIONS The design recommendations presented below are based on the proposed construction, the site and subsurface conditions encountered and our experience in the area. A layout ofthe proposed OWTS components is provided on Figure 1. If conditions encountered during construction are different than those that are described in this report, we should be contacted to re-evaluate our design recommendations. SOIL TREATMENT AREA o The STA will consist of two trenches with 12 Infiltrator Quick 4 Plus Standard chambers placed in each trench (24 chambers total) in the native soils. Equal distribution will be provided to the trenches by a distribution box. o The STA was sized based on an LTAR of 0.35 gallons per square feet per day. o Each chamber was allowed 12 square feet of area. 1^30% reduction of the STA size was applied for use of Infiltrator chambers in a trench configuration. The total STA design size is 288 square feet. Soil treatment area calculations are shown on Figure 3. o A minimum of four feet of undisturbed soil between trenches is required. o Trench cut depths should be a maximum of 3 feet deep. o The trenches should be oriented along ground contours to minimize soil cut and cover. o The base and sidewalls of the trench excavations should be scarified prior to the chamber placement. o A minimum of 12 inches and a maximum of 24 inches of cover soil should be placed over the chambers. . Backfill should be graded to deflect surface water away from the STA and should be sloped at 3 horizontal to 1 vertical or flatter. A swale to divert surface water flow away from the STA may be needed along the upslope side. o Disturbed soil should be re-vegetated as soon as possible with a native grass mix. No trees, shrubs or other plants with deep roots should be planted on or near the STA as this may damage the system piping. r Four-inch diameter inspection ports should be installed vertically into the knockouts provided in the chamber end caps. Install ports at each end of the trench. The inspection Kumar & Associates, lnc.Project No. 21-7 -342.02 -4- port piping should be screwed into the top to the chambers and should not extend down to the ground surface inside the chambers. The inspection ports should extend at least I inches above the finished ground surface or be protected in a valve box at finished grade. o The STA must be a minimum of 25 feet from any potable water supply lines. o The STA must be a minimum of 100 feet from a spring, onsite well or potable water supply cistem. o The STA must be a minimum of 5 feet from the septic tank. o A plan view of the STA is presented on Figure 4 and. a cross section of the STA is presented on Figure 5. OWTS COMPONENTS Recommended OWTS components provided below are based on our design details and our experience with the speciflrc component manufacturers. Equivalent components may be feasible but need to be approved by us prior to construction. Septic Tank o A Valley Precast 1,000 gallon, two-chamber septic tank should be used for primary treatment. A detail of the tank is provided as an attachment. o An equivalent polyiplastic tank may be used. We should be contacted for approval of an alternate tank prior to installation. o An effluent filter should be installed in the tank outlet tee. e The tank must be a minimum of 5 feet from the structure. o The tank must be a minimum of 10 feet from any potable water supply lines. o The tank must be a minimum of 50 feet from any spring, well or potable water supply cistern. c The tank must be set level. The excavation bottom must be free of large rocks or other objects that could damage the tank during placement. A road base or gravel bedding material may be needed to prevent tank damage during placement and act as a leveling course. . The tank lids must extend to final surface grade and made to be easily located. o Install the tank with 2 feet minimum cover soil for frost protection. Maximum tank soil cover is 4 feet. Sewer Pipe r The se'wer line to the septic tank should not be less than the diameter of the building drains and not less than 4 inches in diamctcr. Kumar & Associates, lnc.Project No. 21-7 -342.02 5 a a The sewer pipe should have a rating of SDR35 or stronger. Schedule 40 PVC pipe is required beneath any driveway surfaces. The sewer pipe should be sloped between 2o/o to 4%o to help limit disturbance of solids in the tank and potential sewage bypass of the first chamber of the tank. If a steeper slope is needed, this can be accomplished with vertical step-downs in the sewer line. A minimum 24 inches of cover soil should be provided over the sewer pipe. Paved areas, patios or other areas without vegetative cover may be more susceptible to frost and we recommend 48 inches of soil cover over the sewer pipe in these areas, and the pipe be insulated on top and sides with 2-inch-thick blue foam insulation board. If adequate soil cover is not possible, we should be contacted for re-evaluation prior to installation. The sewer pipe should be bedded in compacted3/q-inch road base or native soils provided that the native soils contain no angular rocks or rocks larger than2t/z-inches in diameter to help prevent settlement of the pipe. Sags in the pipe could cause standing effluent to freeze and damage the piping. Install cleanout pipes within 5 feet of the building foundation, where the sewer pipes bend 90 degrees or more and every 100 feet of sewer pipe. All 90-degree bends should be installed using a 90-degree long-sweep or by using two 45-degree elbows. The sewer line location shown on Figure 1 is considered conceptual. We assume that there will be only one sewer line exiting the structure. It is the responsibility of the owner/contractors to locate all sewer line exit locations and connections to the septic tank. We should be notified if there are other sewer lines exiting the building. a o a a Effluent Transport Piping o The effluent transport pipe should be 4-inch diameter SDR35 piping sloped at a2o/o minimum to flow from the septic tank to the first trench. Piping should extend at least 6 inches into the top knockout provided in the Infiltrator end caps and be screwed in place. Splash plates should be installed beneath the inlet piping to help limit scouring of the infiltrative soil surface in the chambers. o The serial connection between the trenches should also consist of 4-inch SDR35 piping sloped at a2Yo minimum to drain to the next trench. . The effluent transport pipe should be bedded in compacted3/+-inch road base or native soils provided that the native soils contain no angular rocks or rocks larger than 2t/z inches in diameter to help prevent settlement of the pipe. Sags could cause standing effluent to freeze and damage to the piping. Kumar & Associates, Inc.Project No. 2'l -7 -342.02 a a a -6- A minimum 18 inches of cover soil should be provided over the effluent transport pipe. Paved areas, patios or other areas without vegetative cover may be more susceptible to frost. We recommend 48 inches of soil cover over the effluent pipe and insulation with at least2 inches of rigid foam insulation in these areas. If adequate cover soil is not possible, we should re-evaluate the condition prior to installation. Schedule 40 PVC pipe is required undemeath driveway surfaces and should be provided with at least 48 inches of soil cover, and be insulated on top and sides with 2-inch'thick rigid foam insulation board. All 90-degree bends should be installed using a 90 degree long-sweep or by using two 45-degree elbows. O\ilTS OPERATION AND MAINTENANCE The OWTS will require periodic inspection and maintenancs to function properly. A properly designed, installed and maintained system can greatly increase its lifespan. The level of maintenance will vary depending on the complexity of the system and water use habits of the residents. .We recommend that an OWTS Operation and Maintenance (O&M) Manual be developed. Depending on the complexity of the system, a contract with an OV/TS maintenance provider may be prudent. Below are some basic recommendations for the OWTS O&M. OWTS HOUSEHOLD OPERATION o Use of high efficiency water fixtures is recommended to decrease the hydraulic load on the OWTS system. o Fix plumbing leaks immediately as this may cause a hydraulic overload of the soil absorption system. o Do not irrigate the area on top of or directly upgradient of the soil absorption field as this may cause a hydraulic overload. r Do not dispose of household waste down drains as this may clog or damage OWTS components. Examples of household waste includes: dental floss, cotton swabs, coffee grounds, paper towels, feminine products and many other kitchen and bath items. o Use of kitchen garbage disposals is not recommended. If a garbage disposal is utilized, kitchen wastewater should be screened thoroughly. Many kitchen solids are not decomposed in the septic tank and may cause increased tank pumping frequency. o Do not dispose of household chemicals, greases, oils, paints, hot fub water or water softener backwash in household drains. A separate drywell, if feasible, may be necessary for hot tub water or water softener backwash disposal. o Limit the use of bleach as this may hanl useful bacteria in the septic tantrr and soil absorption system. Kumar & Associates, lnc.Project No. 21 -7 -342.02 a a -7 - Liquid dishwasher and clothes washer detergent is recommended for households served by an OV/TS. Clay substances used as fillers in powder detergents may result in clogging of the soils absorption system. The effluent in septic tank may freeze during extended periods of non-use in cold weather. We recommend that a tank heater be installed in this system to heþ prevent freezing. OWTS MAINTENANCE . Inspect the septic tank and STA at least annually for problems or signs of failure. ¡ The effluent filter for the tank should be cleaned at least annually by spray washing solids into the first chamber of the septic tank. o The septic tank should be pumped and cleaned every 3 to 5 years depending on use. Longer pumping intervals may increase the amount of solids that reach the STA, which may shorten its life span. r Pumping of the septic tank should take place when the level of the sludge and scum layers combined take up 25 to 33Vo of the capacity of the first chamber of the tank. OWTS CONSTRUCTION OBSERVATION The Garfield County Environmental Health Department requires that the designer of the system provide a record drawing and certification of the OWTS construction (As-Built inspection). We should be provided with at least 48-hour notice prior to the installer needing the inspections. Prior to issuance of our certification letter, we require observation of all system components prior to backfill. The number of site visits required for the inspection will depend on the installer's construction schedule. LIMITATIONS We have conducted this design in accordance with generally accepted engineering principles and practices in this area atthis time. We make no warranty either expressed or implied. The recommendations provided in this report are based on the site conditions, profile pit evaluations and soil texture analysis, the proposed construction and our experience in the area. Yariations in the subsurface conditions may not become evident until excavation is performed. If conditions encountered during construction appear different from those described in this repotr, we should be notified so that re-evaluation of the recommendations may be made. This report has been prepared for the exclusive use by our client for design purposes. We are not responsible for technical interpretations by others of our information. As the project evolves, we should provide continued consultation and field services during construction to review and Kumar & Associates, lnc.P roj ect No. 2'l -7 -342.02 -8- monitor the implementation of ourrecornmendations, and to verifu that the recommendations have been appropriately interpreted. Significant design changes may require additional analysis or modifications to our design. It is our opinion that the designed location of the OV/TS components does not violate any setback requironents of the current Garfield County Regulations. Below is a table of common minimum horizontal setbacks to OWTS components, Refer to the Garfield County Regulations for a complete list of required setbacks. We recommend the OWTS component locations be surveyed by a Professional Colorado Land Surveyor. Table 1 - Common Minimum Horizontal Setbacks from OWTS Please contact us for any necessary revisions or discussion after review of this report by Garfield County. If you have any questions, or if we may be of further assistance, please let us know. Respectfully Submitted, Kuänrlr ót ..{sss}eistes, åmc. Í'' ,-1 . ..t:",' . " .È,' {¿ -^: .. ,r'' Shane M. Mello, StaffEngineei Reviewed by;.-"-'/' David A. Young, SMMikac \Mells \ilater Supply Line Occupied þwslting Lined Ditch Lake, Irrigation Ditch, Stream Dry Ditch or Gulch Septic Tank STA 100'25',20'l0'50'25',t5 50'Septic Tank 10'5',10'50'l0' Building Sewer 50',5 0'10'50'10' Kurnar & Aasoci*tes, lne.Froject t'lo. ?"1"?"34?"û? d . t¿o¿-% ftø,ùÉ I ;,. , tt. i::: PROPOSED SOIL TREATMENT AREA (STA) CONSISTING OF 2 ROWS OF 12 INFILTRATOR QUICK4 PLUS STANDARD CHAMBERS IN SERIES. 24 TOÍAL CHAMBERS CLEANOUT PROPOSED VALLEY PROFILE PRECAST 1,OOO-GALLON, TWO-CHAMBER SEPTIC TANK ,PtT 2 t PROFILE PIT 1 PROPOSED SHOP BUILDING 6 tl\ I Ê.f-\> --7 0 Rat : I I I t+ $,1 Û "/ Ntp€ *.fr*'e*" 5î fz,frr)Fft VICINITY MAP 1 INCH = 0.5 MÍLES TO COUNTY ROAD 140 COFFEE POT ROAD AREA OF DESIGN SCALE_FEET OWTS SITT PLAN Fig. 121-7 -342.02 Kumar & Associates too 90 80 70 00 50 & 50 20 to o o E to 20 t0 ß 50 30 70 80 90 loo ub IAMETER OF PARTICLES IN MILLIMETERS CLAY COBBLËS ,002 mm .02 SAMPLE OF: SANDY LOAM FROM: PROFILE PIT 1 AT 4 TO 5 FEET ENTIRE SAMPLE PARTICLE SIZE DISTRIBUTION % COBBLES 0 GRAVEL 7 SAND 5¡l SILT 51 CLÂY I PORTION OF SAMPLE PASSTNG #10 StEVg PARTICLE SIZE DISTRIBUÏION % SAND 58 SILT 33 CLAY 9 TOTAL SAMPLE RETAINEÐ oN #10 SIEVE: 7% GRAIN SIZE PERCENT OF MATERTAL RETATNED ON #10 S|EVE PASSING 3,/4" SIEVE: 1OO% (mm) NOTE: Hydromet€r Anolysls wos performed on o bulk somple followlng screenlng of oll moterlol lorger lhon tho #10 sleve (2.0 mm) p6r USDA guidelines. Thosô 16l r€sull! qpply only rompl.s vhlch wcre tcsicd. lô lhâ Thr l€rllng r.porl shqll not b. r.produq€d, oxccpl lñ full, wlthoul lhô wrltl€n opprcvol of Kumor & A$oclol6s, lnc. Sbv! onqlysls tlsllng Is p.rformed ¡n occordoncc wlth ASIU D422, ASIM cljti ond,/or ASTM Dll,l0. I{YDROMEÎER ANALYSIS SIEVE ANALYSIS TIMÊ REAOINOS l MIX2' H¡S 7 HRS l CLilR SOU RE OPENINGS th, t/a' , .ttt U.S. S'AIIDARD SERIES --- ---l-- "---"1-_---,-+---,--f - + - +---'-----.+.-----f-.--.-t--...-.-,-l--.-----f-----;-.-t-- t- SAND GRAVELSILf co.V, FINE FINE IVEDIUM co.v. co.F¡NE MED¡tJM COARSEFINE GRAIN SIZE (m*)SIEVE SIZE % FINER 127.00 5"100 76.00 5"100 38.1 0 1 -1 /2"100 19.05 3/1"100 9.50 3/8"100 4.75 *1 100 2.00 #10 93 1.00 418 E4 0.50 *3s 71 o.25 #60 59 0.1 06 0.045 *1 10 4A t1325 59 TIME PASSEO (min)% FINER 0.057 37 0.019 1 31 0.009 19 22 0.005 60 t5 0.002 435 I 0.001 15¡f5 5 21 -7 -342.02 Kumar & Associates USDA GRADATION TEST RESULTS fig. 2 OWTS SOIL TREATMENT AREA CALCULATIONS In accordance wilh the GarfeH County OWTS Regulations and the Colorado Depaftment of Publb Health and Environment's Regulatbn #43, the soil treatment area was cabulated as folbvls: CALCULATION OF OWTS DESIGN FLOW: Q = (FXBXN) WHERE: Q = DESIGN FLOW F = AVEMGE FLOW PER PERSON PER DAY N = NUMBER OF EMPLOYEES PROPOSED SHOP BUILDING: N= Q= 35 GALLONS PER DAY 4 PERSONS 14O GATLONS PER DAY GALCULATION OF OWTS SOIL TREATMENT AREA: MINIUMUM TREATMENT AREA - Q + LTAR WHERE: Q= LTAR (SOIL TYPE 3) = 14O GALLONSPERDAY 0.35 GALLONS/FTTDAY MINIMUM SOIL TREATMENT AREA = REDUCTION FACTOR FOR CHAMBERS = MINIMUM SOIL TREATMENT AREA WITH REDUCTION = 400.0 SQUARE FEET 0.70 28O SQUAREFEET AREA PER INFILTRATOR QUICK 4 STANDARD CHAMBER = TOTAL CHAMBERS NEEDED = 12 SQUARE FEET 24 CHAMBERS NUMBER OF TRENCHES = CHAMBERSPERTRENCH = TOTAL NUMBER OF CHAMBERS AS DESIGNËD = 2 12 CHAMBERS 24 CHAMBERS TOTAT SOn TREATMENT AREA =288 SQUAREFEET 21-7-342.02 Kumar & Associates SOIL TREATMENT AREA CALCULATIONS Fig. J INFILTRATOR QUICK4 PLUS STANDARD END CAP. 4 INCH DIAMETER PVC OBSERVATION PORTS INSTALLED VERTICALLY INTO THE KNOCKOUTS PROVIDED IN END CAPS. INSTALL PORTS AT EACH END OF EACH TRENCH. REMOVABLE LID ÏO BE PLACED ON TOP OF PIPE. PIPE MUST STICK UP AÏ LEAST 8 INCHES ABOVE FINISHED GRADE OR BE PLACED AT GRADE IN AN ACCESSIBLE VALVE BOX, PIPES SHOULD NOT EXTEND TO SOIL SURFACE AND SHOULD BE SECURED TO CHAMBER WITH SCREWS OR COUPLINGS TO PR SLIDING DOWNWARD 4 INCH DIAMETER NON_PERFORAÏED SDR55 TRANSPORT PIPE SLOPED AT A 2% MIN. DOWN NEXT TO TRENCH. 4 INCH DIAMETER NON_PERFORATED SDR35 TRANSPORT PIPE SLOPED AT A 2% MIN. DOWN TO ÏHE TRENCH. INFILTRATOR QUICK4 PLUS STANDARD CHAMBERS IN 2 TRENCHES. 1 2 CHAMBERS PER TRENCH (24 TOTAL). NSPORT PIPING SHOULD BE INSERTED AT LEAST 6 ÌNCHES INTO THE UPPER KNOCKOUT IN THE END CAP. INSTALL SPLASH PLATES BENEATH INLET PIPING TO HELP LIMIT SCOURING OF THE INFILTRATIVE SURFACE. 10 10 20 SCALE_FEET Notes: 1. Chambers should be installed level on a scarified ground surface. Concrete sand may be used as a leveling course if necessary. 2. Care should be taken by the contractor to avoid compaction of the native soils in the trench areas. The base and side walls of trench excavations should be scarified prior to chamber installation. 3. All piping should have a rating of SDR35 or stronger,4. Changes to this design should not be made without consultation and approval by Kumar & Associates.5. Refer to the Garf¡eld County Onsite Wastewater System Regulations for other applicable specifications. 21-7 -342.02 Kumar & Associates SOIL TREATMENT AREA PLAN VIEW Fig. 4 12" min, 24" max. Cover Soil Graded to Deflect Surface Water Excavate 36" Wide Trench lnfiltrator Quick 4 Plus Standard Chamber lnstalled Level APÞrox, Exis¡¡rr a,.rra Surface Scarify ground surface prior to chamber placement, Notes 1. Chambers should be installed level on a scarified ground surface. Concrete sand may be used as a leveling course if necessary. 2. Care should be taken by the contractor to avoid compaction of the nalive soils in the trench areas. The base and side walls of trench excavations should be scarified prior to chamber installation. 3. Changes to this design should not be made without consultation and approval by Kumar & Associates. z.0 SCATE_ FEET Native SoilSoil Between 21-7 -342.02 Kumar & Associates SOIL TREATMENT ARTA CROSS SECTION Fig. 5 {OOO Gallon Top Seam -2CPlúrn # {00m¿cp 11 Top View DESIGN NOTES¡ Design per performonce test per ASTU C1227 f-:-.--:¿. 1- ¿.r¡-i' o Top surfoce areo 46,25 ft¿r fc @ 2E do¡rs; concrete = 6,0O0 PSI Min. lnstollotion:¡ Tonk to be set on 5" mln. sond bed or peo grovelo Tonk to be bockfilled unlformly on oll sides in llfts less thon 24" ond mechonicolly compoctedr Excovqted moterlol moy be used for bockfill, provided lorge stones ore removedr Excovotion should be dewotered ond tonk filled with woter prior to being put in service for instollotion wlth woter toble less thon 2' below grodeo Meets C1644-06 for resilient connectorso lnlet ond Outlet identifled obove pipeo Dellvered complete wlth lnternol piping ¡ 4' Moximum bury depth CLü ii TAI[( ID .-3?' , =FiY,Î \ bGrado Fb¡dble Rubber 8ælant 6i J" 5t to 5i ln Section View Digging Specs 11' Long x 7' Wide 56" below inlet lnvert Dimenslons I l t;l ì ! Net Copocity width ' Heigfr ' 68" : nlet Side rOutlet a . :ZS got Totol ïotol 12000 lbs6a7golgol ALLOWABLE BURY (Bosed on Woter Toble) WATER TABTT ALLOYYAtsLL FÁRTI{ FII I o'-0"2'-O' 1'-0"3'- 0' 2'-O'3'- 0" 3'-O'4'-O' DRY 4'-o' 1 Phone: 7{9€95'6204 Faxz 719-3%-37t1 Wcbelb; rYrrrv.valleypmætæm Emll : fronüæk@vallepætæmBucna Vbte, Colorado PRtCASfrrnc.