Loading...
HomeMy WebLinkAboutOWTS Engineer's Design & Installation Report 11.20.2019CIVIL WATER RESOURCES ENVIRONMENTAL OIL & GAS Badwater ENGINEERING & CONSULTING, INC. November 20, 2019 696 COUNTY ROAD 22 CRAIG, CO 81625 (970) 326-3350 Garfield County Community Development Department 1088th Street, Suite 401 Glenwood Springs, CO 81601 RE: 2732 HYW 13, Design Report, Site Plan and Construction Certification for On -Site Wastewater Treatment System Drainfield Replacement. Dir Sir or Madam: On behalf of the owner, Salvador Tovar herein included are this design report, as -built drawings and construction photos pertaining to the subject OSWTS. The system is a repair of the existing on-site individual sewage disposal system that was designed to treat and dispose of single-family domestic waste from a 3 -bedroom, house. The existing system has since failed. The existing drainfield, which is believed to be substantially undersized, is located to the southeast of the house. It's my understanding that the existing septic tank has a capacity of 1,000 gallons, in which case, is adequately sized for the home and will be re -used. The nearest surface water, an irrigation ditch, is located approximately 75 feet away from the drainfield. Preliminary Investigation A detailed soil investigation for the proposed drainfield location was conducted September 5th by me, a licensed professional engineer. As shown on the plan set, included as Appendix A, several soil profile pits (SPP), located in the vicinity of the proposed drainfield, were evaluated visually and tactilely based on texture, structure and the ribbon test as required for the septic system in accordance with CDPHE/WQCC, Regulation #43 Section 43.5.D.2. Neither bedrock, nor signs of groundwater nor other limiting layers were evident in any of the SPPs. The soils in the vicinity of the drainfield grade from sandy loam to sandy loam with gravel. It was initially thought that the irrigation ditch was leaking and saturating the soil underneath the proposed drainfield. However, during my September 5th inspection, water was not observed in any of the soil profile pits/excavation holes. According to the owner, the water in excavation holes was the result of his pumping effluent from the failed system and/or where the ditch overtopped during a significant rainfall event and ran downhill into the excavation holes. During my inspection I did not see anything to suggest that the irrigation ditch was leaking out the bottom and saturating the soil in the vicinity of the drainfield. Design Based on the results the tactile soil evaluation, the drainfield was sized using the methods outlined in CDPHE/WQCC, Regulation #43. The design calculations are presented on Sheet 2 of GCCDD November 20, 2019 Page 2 of 4 the plan set. With minor exceptions, discussed following, the replacement system was constructed in accordance with the design plans and specifications. Certification of Completion of Construction In accordance with Section 4.F of CDPHE/WQCC, Regulation #43, please accept this letter as certification by me, the design engineer, that the subject Onsite Wastewater Treatment System (OSWTS) was construed in accordance with CDPHE/WQCC, Regulation #43 requirements and the design plans with minor exceptions, neither of which will significantly affect the long term performance of the system. The minor exceptions to the design include: 1) The system was constructed with 48 total drainfield chambers rather than the 52 specified in the design. This was approved since the minimum number required was 44. 2) The distribution pipes from the distribution box enter the bottom of the drainfield chambers rather than the top. This was ultimately approved, but with the recommendation that chambers be lowered six to eight inches so that the pipe could enter at the top and thus allow the chambers to fill to full capacity without backing effluent up in to the distribution box. The owner chose to keep the configuration as constructed with the acknowledgment that the long-term effectiveness could be slightly diminished by doing so. Photos of the OSWTS during my November 16th, 2019 inspection are included as Attachment B. Please let me know if you have any questions of comments about the design of this septic system. Best regards, /4 / Will A. Myers, P.E. encl: as noted cc: Salvador Tovar C \Users\Will\Documents\Headwater\Jobs\Linsacum\Linsacum Septic System_Rep_100819 docx Appendix A As -Built Drawing AS -BUILT DRAWINGS: ON-SITE WASTEWATER TREATMENT SYSTEM DRAINFIELD REPLACEMENT SALVADOR TOVAR 1558 ARABIAN AVE RIFLE, CO 81650 EXISTING DRAINFIELD .10 EXISTING 1,000 GALLON SEPTIC TANK 4" 0 45° ELL 4" 0 45° ELL S 4"0SCH40 EFFLUENT PIPE L= 45' S= 2 5% CONCRETE OISTRIBi1_TK]N BOX 4"0 SCH 40 ISTRIBUTION PIPE TYP. SPP3 INFILTRATOR WATER TECHNOLOGIES QUICK 4 DRAINFIELD CHAMBER (TYP OF 12 PER LATERAL) (48 TOTAL) 4" 0 INSEPCTION PIPE (TYP OF 4 END CAP (TYP. OF 8) x X x -o 1 25 TYP 4 4" 0 90° ELL (TYP OF 6) PROPERTY LINE SITE ADDRESS: 2732 HWY 13 RIFLE, CO 81650 LOCATION: LOT 4 (SWSW} SECTION 31, T.5S.; R.92W. AS -BUILT PLAN VIEW SCALE: 1"= 20' CI. 1' LEGEND SPP 1 SOIL PROFILE PIT NOTES: 5550.0 5540.0 5530.0 5520.0 4"0SDR35OR50140 EFFLUENT .INE L•-45' DISTRIBUT ON BOX EXISTING SEPTIC TANK S = 1.0 IS. OFT (MIN.) ra r 16"x16" CONCRETE SPLASH POCK 1 RAL 3 0 SDR 35 OR SCH 40 DISTRIBUTION PIPES L-65' d' DRAINFIEI (TYP. OF 13 (52 TOTAL) 4" 0 IN'ECTION PIPE EACH D (TYP. OF 4) 12" (MIN.) CMAUSERj36' IMA)f.) 'ER LATERAL) - _----- 1 1 1 1 , 1 1 It.ATERAL 4 sr 0+00.00 0+20.00 0+40.00 0+60.00 0+80.00 1+00.00 1+20.00 1+40.00 Design Profile SCALE: 1" = 20' 1. HEADWATER ENGINEERING INSPECTED THE SYSTEM INSTALLATION 11/16/19. SYSTEM WAS DETERMINED TO BE CONSTRUCTED IN ACCORDANCE WITH DESIGN PLANS AND GENERALLY WITH CDPHE/WQCC, REGULATION #43. 2. AS -BUILT PLAN VIEW WAS PREPARED BASED ON MEASUREMENTS OF THE CONSTRUCTED SYSTEM AS OF 11/16/19. THE PROFILE SHOWN WAS THE DESIGN PROFILE PROVIDE TO THE THE APPLICANT AND IS FOR REFERENCE ONLY SINCE THE CONSTRUCTED SYSTEM VARIES SLIGHTLY FROM THE DESIGN. 3 UNLESS OTHERWISE NOTED, ALL PIPE AND FITTINGS ARE SCH 40 PVC. 4. NEITHER BEDROCK, GROUNDWATER NOR OTHER RESTRICTIVE LAYERS WERE ENCOUNTERED IN THE SOIL PROFILE PITS OR OBSERVED DURING THE AS -BUILT INSPECTION. 5. THE SITE WAS ORIGINALLY SURVEYED WITH A SURVEY -GRADE GPS FOR DESIGN, THE AS -BUILT CONFIGURATION WAS BASED ON FIELD MEASUREMENTS USING A CLOTH TAPE AND A LEVEL AND ROD. 6. THE SYSTEM WAS CONSTRUCTED WITH 48 INFILTRATORS, WHICH IS FOUR LESS THAN DESIGNED, BUT FOUR MORE THAN THE MINIMUM REQUIRED. (SEE DESIGN CALCS.) 7. EVEN THOUGH SEPARATE TRENCHES WERE NOT EXCAVATED FOR EACH DRAINFIELD LATERAL, THE LATERALS ARE SPACED SUFFICIENTLY SO THAT THEY WILL FUNCTION AS TRENCHES RATHER THAN AS A BED CONFIGURATION. 8 THE APPLICANT WAS INFORMED THAT BY INSERTING THE DISTRIBUTION PIPE INTO THE BOTTOM OF THE INFILTRATOR END CAP RATHER THAN THE TOP HOLE AS DESIGNED, THE CHAMBERS WOULD NOT FUNCTION AS EFFICIENTLY IN THE LONG TERM. THE APPLICANT CHOSE TO KEEP THE SYSTEM AS CONSTRUCTED RATHER THAN LOWERING THE CHAMBERS TYPICAL SOIL PROFILE LOG 0-4" TOPSOIL 4" - 4' SANDY LOAM, TAN 4.0' - 10' SANDY LOAM WITH GRAVEL INDEX OF SHEETS SHEET NO. SHEET TITLE 1 TITLE/INDEX SHEET, AS -BUILT PLAN & DESIGN PROFILE 2 CALCULATIONS & OFFSET DISTANCES DESIGNED BY: adwater ENGINEERING & CONSULTING, INC DESIGN CALCULATIONS 1, Design Flow Rate AA ebtlbe kles tf MORN RISEN* Water 4444 Lige a' MIN MOM MOM Riegle Mks Spey Lxwm acs 1.11.11P.. 1250.0 Dlesign Component 91e5eme! nett ee.minr0 1.44105 huger Ore.e.2 utllw le0tr Cam. 114042m Olds. Sheen, .10505 >o NotesdInformation Source Peak da ity design flow ra: 450 gpd al.mmle ta.dr. 3 -Bedroom House Sandy Loam iein Imo egrrlrN 1..0...n LK DP6404 f. n4 SO4 Type: No. of Bedrooms: 3 Table 1114 Tresimenl Lexi Occupants based on Bedrooms: 6 Table 10.1 Table 6.1 Wastewater Flow per Occupant: 75 gpd Tabte 6.1 Daily Design Flow Rats: 450 gpd Adiusanent factor for chambers 0.7 tweif9..s4rlr'm.n nlWa Odom ele5sA Lief litnirrim Pam Table 103 Admitted &anna10 abaarpf on arra 1I. Septic Tank Design rui 11 25 Wldlh of drainfeld chanter 3.0 Design Component Standard S. Total malted length al drair 6011 Notes/information Source 20 25 Lenoir.. of draroilaid chribet 4.0 .bedroom House 5 foot ala Slandad Mn required number 00 grainfield chambers: 44.00 No. of Bedrooms: 3 Number of 4' grainfield chamber In proposed design: 52 Min. Septic Tank Capacity Based on Bedrooms: 1,000 gal Table 9.1 Design Septic Tank Capacity 1,000 gal Sources/Notes= M sources of information and design requirements are CDPHEIWQCC, Regulation #43 M. Drainfietd Design AA ebtlbe kles tf MORN RISEN* Water 4444 Lige a' MIN MOM MOM Riegle Mks Spey Lxwm acs 1.11.11P.. 1250.0 Dray% Component 91e5eme! nett ee.minr0 1.44105 huger Ore.e.2 utllw le0tr Cam. 114042m Olds. Sheen, .10505 >o NfotealnIo n106on Source Peak da ity design flow ra: 450 gpd al.mmle ta.dr. Sod !ensure unthintnerdainhl& Sandy Loam iein Imo egrrlrN 1..0...n LK DP6404 f. n4 SO4 Type: 2 le a/ Table 1114 Tresimenl Lexi 1 9M 05 Table 10.1 ILeregTenn Acceptance Rate (LTAR)': 0.6 golidaye sq a Table 10-1 Required drairs 1d stingeion area 750 sq 1t Adiusanent factor for chambers 0.7 tweif9..s4rlr'm.n nlWa Odom ele5sA Lief litnirrim Pam Table 103 Admitted &anna10 abaarpf on arra 525.15 rui 11 25 Wldlh of drainfeld chanter 3.0 11 Standard S. Total malted length al drair 6011 1750 20 25 Lenoir.. of draroilaid chribet 4.0 it 5 foot ala Slandad Mn required number 00 grainfield chambers: 44.00 5,2 0•1` 55 Number of 4' grainfield chamber In proposed design: 52 chambers 1051 Mamba- of sones: T 25 25 toe 15 ries kiIII.M. Number of ialerals per x one: 4 125 m a 25` 15 w Number of 4' chambers per latent 13.00 Lateral length: 57 11 Total lateral length: 206 6 Niw4 Ass01C11 belwaco trenches: 4 a Section 43.10.F.1 Nin bench CL spacing: 7 16 !Design trench CL spacing 10 16 Menlo/al space to pale sail Soura>dN otes: All sal$Se. N>f information and design requirement BB CDPHEIWQCC. RegL eat»n 143 »Ness 05'000se 10000- ' Oetam.nad *um a Geld sal ewtuatlan OFFSET DISTANCES Art.4e lalr.5.meager aaWeee s.r.w 11re04440.p5..r41eeG.444Ylmm.r.11 lnat45e421 _I._,__ AA ebtlbe kles tf MORN RISEN* Water 4444 Lige a' MIN MOM MOM Riegle Mks Spey Lxwm acs 1.11.11P.. 1250.0 Pegging Liam P15.4 et lived ..v60• 91e5eme! nett ee.minr0 1.44105 huger Ore.e.2 utllw le0tr Cam. 114042m Olds. Sheen, .10505 >o De 42619e Cul 15.4 TM Nem Pam 42.254 M 5nel1. Vet* .cored &roar 4 Dace 10 al.mmle ta.dr. 10 iein Imo egrrlrN 1..0...n LK DP6404 f. n4 15 1014 le a/ 0 1 a W A 4 I 10 la' a tI .ie' 9M 05 1 ....egel.rr .r154r5 lame Ka law*. n 4r41l1506 aur. aura. niter... rt'e's. 5.44•0•111 Lege .5m eras m ID' x5 n '0 tweif9..s4rlr'm.n nlWa Odom ele5sA Lief litnirrim Pam eu ter' a 15 to W. 25 tD 5 100 25' W 15 14 20 25 15 a- la 10.01.4er0Msnel4u. •srao 1,1•141461.442, Ag PAY= p IbL are4tnrl Lw. r .0m.r Wales elm soOmSdur. Mie.1e4W e1s.e12 Peed, ee 5rdgegekg F1.06.1 ge VA Iv ..* Orlo. ion ?omit Arileal 5,2 0•1` 55 13 TO 2 55 '0 - 9e i+aa ram. Pa ferry 1051 25 5151 25 25 toe 15 ries kiIII.M. tad` 16, 50 125 m a 25` 15 w I.li4..rrhe SWIM !solea cele 11••••••.n.1.••••....1.4.. 0.0 erw..rr>_...e.reer eer.rtw.P rawwr...w.w mom. er.m..y9.tr.ncom:�Rw11 0 Ce..C. P4+t..ewr..a..f54481. r.MNeG+.4t re.rr. ww.i y..n 1Y •••••,••lti��w S amnaa....k�Mm.. ro �00t- IrMrgwmpmr.etlrwml. Meearwro d W+aR®re. »15....000...04._.._S10 -_.10I rnrrrr� ' �atNl.rilr.rnlr. CeWw.lr.lM.1.o-�.Y.wq .ti r+. nnTPM vra•r ,..allx Y1...0.0. Mv..a /....11l.wrM..+./.wyr. wn yr`..-ranoµ ewe r.�-wn err. ne..geite.wwe.. Mr.r rrl...�+err .p wlTiwaw.rrM�•rrrrr+�+YF M�wnw wa.rtr.. 222 �....ewes rrr,mwr srm e•enenm.• mercer 11rNF14.' ... M...1r•rr.r. .w.+.0• Se...xr Pre�. a aw .v. rr rte. wit. w:. ro rrr�i..rwr-.mom-..+'rr/•.rr►+er Jnr."en.r=......w.....r.r...r.•.l.rg ae.ra•.w.s..e.g.5. 11e1/1072 nrt•.rt. yvs.araw T10010515155.4r.5 4i05 00001 5radrl 05d TPmiEerr -S.05SD1oW,s.. !tone Soil Trmw1141114204 fCEat. I MIS DESIGN colisct5RAr1DN 41er1 01111 Separation gEtiaea 2 PRESEGXE 00604c /98:11l91ip Traarrea Limas / and 2 lte0 L...l 2M Tluhe4ae Loyd 3 Trues lava 351 Simms iron al ttatbnr4 ems baeele Ina Dle.ta, ern sw 1ainramaa4-. 1505.5615.15156115 4rhta maliadmi Mom. eye d a4wrrert1101119h e.ar [camber" a Arai el f..r 1010 .OL er54er4.41. 4 Y10talll5 .0100011.0 f/RAM Sp Creaky 0m or 5gt5: t1 100 t.10 65.10» sorsa prof to LD rhe I OrmYM or 54019t. 21 w aleaOape set timing!' dolma 6a.05r tort 4regtwl to 100 feet Clemdr then or ottuot to 25 tot Cdtrarko awes or equal m 10 101 (dean Mon or mod Co 100 Ater Lieu tha1 or mud 4,25 Foot Gleam elan egewl to 10 toot &T ee04r Mai avg of to FS G mew blear arergot to25 bet Go®laa bad crowd to Id leer Ca.wr awn 1001541 t92 Greeter Wrap or equal to 2 feet Gteolt. Man crewel 102 Bast Mir 0 15 1..m a. 0Rect ,Apr./ -r fledlrmbn.a12prea0 p•.rm rel fare, earr..l..•1 It be greeted rely 0tlle Nrml rr81c1ealth mom ryl1lba 050525••1504, m1 Nnegia-.ez r 05 b e4P5.a al woos! ree.Yo r ower. erre 1051acer9wterrv0 et ewes Ear rrl.err.Kn4M era, t to cern... tin roe renengg leers. I a 1arrin.ae.nre. 5 relate 10Cey.0y Wu.+1l.1.1e4erre4 40510100050504 INFILTRATOR SYSTEMS INC. QUICK4 PLUS STANDARD CHAMBER TYPICAL TRENCH DETAIL SECTION VIEW (NOT TO SCALE) NATIVE BACKFILL 6" COVER 12' COVER H- I 12' • TOPSOIL INVERT 1- SPACING PER C.BEC .L- LENGTH AND NUMBER OF TRENCHES DETERMINED BY DESIGN e+ruTRAroR owe. rel.TN.YA1 C.141/eOT1 TYPICAL TRENCH DETAIL s41121,1941Y 0 3 5. 3 m 0 w K COORDINATE NO 50 c N u 0 t R N a u__J ao wC 4J G u a b = U L z c7 Udi 1- z W 2 W V J to O Z W O J 1V QaZ Q I.L 0 co O SALVADOR TOVAR 1558 ARABIAN AVE RIFLE, CO 81650 SHEET 2 OF 2 Appendix B As -Built Photos