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HomeMy WebLinkAboutELDRED S10359Onsite File s l Eagle River Engineering Services Louis Butera, P.E. P.O. Box 773294 (907) 694-5195 tel Eagle River, AK 99577-3294 (907) 694-3297 fax December 6, 1998 Jim Cross, P.E. Manager, On -Site Services Municipality of Anchorage P.O. Box 196650 Anchorage, AK 99519 Re: Proposed subdivision of lot 75 T15N Rl W SEC 8 S-10359 Dear Mr. Cross: DEC 8 1998 Municipality of Ancnarage Dept. Health & Human Services At the request of our client, we have completed the soils investigation and report for the proposed subdivision of Lot 75 T15N R1W Sec 8. The lot will be split into 2 lots, with the dividing lot line as indicated on the preliminary plat. Before our involvement with the project 2 testholes were previously excavated near the West lot line for the proposed lot 75B. The percolation test bench's were still open and allowed examination of the soils in that area down to a depth of approximately 7' below the existing ground surface. This revealed a fill material composed of a silty -sandy mix. This fill was extremely inconsistent, having a more sandy soil on one side of the hole, and almost a pure silt on the other side of the hole. Previous soil logs submitted by the owner listed the testhole #1 as having a percolation rate of 40 minutes per inch, and the testhole 42 having a rate of 80 minutes per inch. The soil logs are attached. Due to the inconsistency of the soil and the proximity to the edge of the filled area, it was decided to abandon this area and examine the Northwest area of the proposed lot. Test hole #3 (our TH1) was excavated just below the top of the 21% slope leading down to the North as shown on the topography mapping. The approximate position of the well to serve the lot was staked, and the testhole was placed approximately 130' from the proposed well location. TH1 showed fill material to a depth of 11'. This fill differed from the 2 testholes previously dug, having more of an organic content. No ground water was encountered in this test hole. Because of the fill, this was not an acceptable location for the septic system reserve area. Test hole #4 (our T112) was excavated at the bottom of the 21% slope on the North half of the lot, in an area having a slope of approximately 7%. This location appeared to be entirely on the undisturbed native soil. Favorable soil for the installation of a septic leachfield was indicated in out soil log attached. Groundwater was monitored at a 7day stabilized level of 9.8' below the ground surface at a typical seasonal high water table period. A percolation test was conducted at a depth of 3' below the ground surface, and a percolation rate of 1.3 minutes per inch was established. For a 3 bedroom house, a leachfield can be installed utilizing a 5' wide shallow trench with an effective depth of 2.5' of sewer rock. This test hole also shows that the west lot of \1998\98 -069 -soil rpt -MOA this proposed subdivision meets the requirements as stated by the Anchorage Municipal Code, 15.65.180 requiring a reserved area of 10,000 SF which is available in this portion of the lot. We have also prepared a permit request package for installation of the leachfield when the subdivision is completed. While we know we cannot apply for the permit until the lot is platted we are demonstrating how the systems will be installed. The existing house (proposed lot 75A) has a leachfield installed with no record of installation and it is located with in the 100' radius of the onsite well, the owner has agreed to install a new septic system and we have completed test holes and will submit for a permit to obtain approval. A copy of the permit application package is attached. The onsite well was tested for flow and water quality. The well is noted as being +185 deep and the static water level is 77' showing casing to +40' depth. A well flow test report is attached. The area wells have been researched and it is found that the wells are producing an average of 5 GPM. This acknowledges that there is adequate water supply in the surrounding area. Representative well logs are attached along with a summary map of locations and record well production. The soil logs for each test hole are attached for further details. Test hole locations, topography and locations of improvements are as provided by the surveyor accomplishing the subdivision. We recommend this subdivision for approval. If you have any questions, feel free to me directly at 696-7375. Sincerely, Louis Butera, P.E. OF Ai"i qMW e�� g =� Louis A Butera i4F OA % CE -6736 .•S'0 \1998\98 -069 -soil rpt -MOA 2 SEP -70-!E98 10--5b 1IrrNA ErR.-E L1 E 507777555- P. 0101 Shin"lakanis Subdivision Plat 6-20 �4 f Q 8' ROW Reservation °fes per Piot 86-20 �y 25' ROW per Plat 86-20 I N 89.57' E 305.31' '-+— 33' Easement ona If V%6' alders Aar' -.- C> N ► . - l i . .5 $ _-Etd ,aiis r 56,1 7T sq= -fit:; ias N 1 ,L- $ "" ere& tto gals o{ Siope Existing 'well f,t;c,---_-'='' Jai �-- i1D---- g Nev t2fl }c 4 Rnodway S8„ � $ ir"Stin9 ' OF p ..e•9"J t/ L 'w °it * O Z Lot 102 °{ o r� N SubcUAsior l a cies �" CD Existing Septic Pipes 0 �R r 94.4' as E a� 0 O 11.1 0 )" P. Wrrxm , a Site Survey of »....._. U.S. Lot 75 Section 8, T15N, R1 W, Seward Mer7dian Hofffman\ 3550 W. Dimond Blvd #403 Zllk0 surveyors Anchorage, AK„ 99515 (907) 562-1830 Grid: NW 1356 Scale: 1 "=50'I Date: Sept., 1998 Drawn: TH Chk: JZ TOTFL P.01 No 4LV9LZ 1 AUG -31-98 MON-10:06 AM LOM Inc. hAX NU, yU1 bbl 1831 N. U2/U4 LOAF Incorporated .1 iubdJlury ufNparlt Inup&, co,powlon09 EW Sist c (807) 552-1030 M.het 0-!N * 9050] F.tr•. (107)+.7-11]1 PERFORMED FOR: LEGAL DESCRIPTION: `rr!' r 'DEPTH FEES ® Soils Log ® Percolation Test D -i u o 1 flO A-4071 DATE PERFORMED: VS L-07"' 7 -1IP- e%1cli rlSAl, 'i/lv SLOPE SITE PLAN 3 . 4 fop-QD15h F.jR)v-ly, JaNcho StvrON - 7 a, Gravel WAS GROUNDWATER ENCOUNTERED? 1 • g O P IF YES, AT WHAT DEPTH? E 10 �t gt7.au� F1 12 13 gn r l•1 oVTw. mw 6 e Sc -oft L• t °�'i'q. IVY.IAFV e• ® pl c ko, •'iree No on, MEN NoNo9 0 OMMENTS: Ko(.� wtellT va•Y PERCOLATION RATE L.10 (minutes4nch) peb TEST RUN BETWEEN t,, 5 _ FT AND _0 FT 011 7)r, 2 PERFORMED BY: — CERTIFIED BY: Aiaf ?I— DATE: g 1 -1 I DATE: HUU-.i 1-yb I'IUN- 1 U; U f till LU111' 1 11 c. LMF incorporated 179 Emil 51,1 A.eu. V11— (907) 502'1070 M.ho,.u.. Nmik. 00500 Far. (9071502.1811 r-';�-=(zG 1'11x1 HU. JUf JUL IUJI �C] Soils Log (1 Percolation Test PERFORMED FOR: LVIDNFa'I Nn1'? �=c U�r r� DATE PERFORMED: LEGAL DESCRIPTION: () 0, T SLOPE SITE PLAN 3 5 s 6 !;1 v ; •. eI�r a ►�� Fill _...._. - 0 12AV [ 1.A -i 581.1' CiG�.) Av r - (.J/�r�T'a ,G' J ;2 LI) Mm u X31 O 4+ I rl _ . 0 1 — %0 , ;z7r 7 � / s M 2::�'WAS GROUND WATER ENCOUNTEREDT L g O IT © P 1F YES, AT WHAT DEPTH7 E 9 r. Reading Date Gross Time Net Time Depth to Water Net Drop ;2 LI) Mm u X31 O 4+ I rl _ . 0 1 — %0 , ;z7r o° 1- �e, ¢ PERCOLATION RATE u U (rAll�b (minutes/Inch) �!. ee (eeee eee ♦tib ..••I FT Pd`'l`� " TEST RUN BETWEEN FT AND . %r C7 01 seepe. at6 eo eaeeleq1... • r'�O•4e�i'0 ,� ti� �N 01 `� l `� 13 cbMMENTS: t.. P C vt1 p 20 DATE: B/-5/ ! 9 PERFORMED BY: / DATE: CERTIFIED BY: e Municipality of Anchorage DEPARTMENT OF HEALTH & HUMAN SERVICES 825 ••L" Street, Anchorage, Alaska 99502-0650 SOILS LOG — PERCOLATION TEST left®O _ -_®®� I N EAL fit ° Louis A.8utera �• CE -6736 c el acs sevvmW+°°� �a PERFORMED FOR: G /G�/� DATE PERFORMED: LEGAL DESCRIPTION: Lo T Township, Range, Section: 1 qP SLOPE SITE PLAN F(F E T ?"S' 2 D 3 GP �c�os�/6/Owh 4 ` 5 d d 7 8�- �CI M 9 0 � 11 12 13 14 15 3, S 16 17 18 lei 19- 20 COMMENTS S�, N h WAS GROUND WATER �c f ENCOUNTERED? S IF YES, AT WHATL DEPTH? P E Depthto Water After Montt r //--1-13' Monitoring? Date: '61 7 Reading Date Gross Time Net Time Depth to Water Net Drop lZ vF 3'22 vv '/� 611.. J 2;12- 3 'z9" vo 3'zy" o Z//c '7S-- -7//,f D,si PERCOLATION RATE (minutes inch[ PERC HOLE DIAMETER 61 TEST RUN BETWEEN FT ANDI_ FT =agte Hitler L-ng:neenn,g arric2s PERFORMED BY: P. 0, Bou i -:i:q t RTIFY THAT THIS TEST WAS PERFORMED IN ':a7!e River, 'K 99577 _ 7 — 5� ACCORDANCE WITH ALL STATE 6NDj 5,-NICIPAL GUIDELINES IN EFFECT ON THIS DATE. DATE: 01 Municipality of Anchorage DEPARTMENT OF HEALTH & HUMAN SERVICES 825 "L" Street, Anchorage, Alaska 99502-0650 SOILS LOG — PERCOLATION TEST % OF .4Z%%%j 0 4------� ......•.... 5... Louis A. Butera jg CE -6736 "®•emva•v��® � 3i►�. ��SS10� PERFORMED FOR: G t� DATE PERFORMED: LEGAL DESCRIPTION: 1-,7- Township, Range, Section: %1S /y R) W sc c S DF�PTH SLOPE SITE PLAN 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 ■■■ Net Time Depth to Net Water Drop -- -Pj• c ^ ■■■■ ----}- -� Ir. -5-8 M■■■ ,\MES /� Zp 3cv,- , 3 z. ' Z//6 ■1®■■ EIV■■ 3 2- M,-0■ 3 2 -'Z 32 -'Z ,& it'a+ ME MEIRM MORE ' fes• �o �'a ..., M MEME MEMO r I ISO ER e S L I I 0 Z�r E � Ual� ll-�p_gy W Gross Time Net Time Depth to Net Water Drop -- -Pj• c ^ S 0A<cp ----}- -� Ir. -5-8 3z '/r /� Zp 3cv,- , 3 z. ' Z//6 3 2- 3 2 -'Z 32 -'Z ,& it'a+ -5 2- ' fes• �o �'a ..., Z /Y//6 r 3 6 (minutewinch) PERC HOLE DIAMETER TEST RUN BETWEEN 2 FT AND 3 FT COMMENTS er ng; errrg C; J!Cc i -�� PERFORMED BY: P. 0• Box 7732�4 CERTIFY THAT THIS TEST WAS PERFORMED IN Eagle Mver, a-K9^3;T ACCORDANCE WITH ALLSTATE Ai D."--VNICIPAL GUIDELINES IN EFFECT ON THIS DATE. DATE. 0 0 CJX' AC -1h '06C0000,0 'S'CD ENG ® Municipality of Anchorage DEPARTMENT OF HEALTH & HUMAN SERVICES, ® Louis A. Butera 8 825 '•L•• Street, Anchorage, Alaska 99502-0650 ci °00 CE -6736A e �av SOILS LOG — PERCOLATION TEST �� �®mo ® PERFORMED FOR: E I d r e LEGAL DESCRIPTION: 7Y— F// Y— 4- 5 5 6 D. 7 9 10 11 4 12 13 14 15 16 17 18 19 20 F" /l.frll 5'000/ tdiTA 9rQVe-1 0�9a��'c /KaTTer L o Jrs 8c"tTo.v '� TV '°jos=�ss►a'�P�'� DATE PERFORMED: Township, Range, Section: %-lS/t/ — SLOPE SITE PLAN WAS GROUND WATER ENCOUNTERED? /yo S IF YES, AT WHAT a'� 0 2-S DEPTH? I P E Depth to Water After "J °T c1K Monitoring? ""1/-4 Date: Reading Date Gross Net Depth to Net Time Time Water Drop -Vo � lrkS 7 - PERCOLATION PERCOLATION RATE (minutes/inch) PERC HOLE DIAMETER TEST RUN BETWEEN FT AND FT COMMENTS lVelr eagle RIVEr Engineering Services V. 0. box 77379-4, PERFORMED BY: Eagle Myer. AK 995 :' CERTIFY THAT THIS TEST WAS PERFORMED IN 694-5195 ) ACCORDANCE WITH ALL STATE AND MUNICIPAL GUIDELINES IN EFFECT ON THIS DATE. DATE: 72-008 (Rev. 4/85) O +.e Municipality of Anchorage DEPARTMENT OF HEALTH & HUMAN SERVICES 825 °'L" Street, Anchorage, Alaska 99502-0650 SOILS LOG — PERCOLATION TEST PERFORMED FOR: K / d it e—J LEGAL DESCRIPTION: �OEPTH, T -y '-/ 1 2 •� j� CJ 3 4- 5 5 6 C'> 7 r- 8 ".. 9 �p 10 11 12 13 14- 15- 16- 17 4151617 18- 19- 20- COMMENTS 81920 COMMENTS / �— -T,-psoi l DATE PERFORMED: Township, Range, Section: "rlr it RI W B — SLOPE SITE PLAN 21 5P W" -Th TUD/'// 9ruVe/ 5a,TTO^y Tis% llelc Z WAS GROUND WATER y ENCOUNTERED? /CS S IF YES, AT WHAT + J� v L 2—S DEPTH? [ P E Depth to Water Atter Monitoring? S Date: y -7o Reading Date Gross Time Net Time Depth to Net Water Drop -az-� la•' Y 6 7' Ll " yy ya" Lly" 3 13; OS t7 V L1 q PERCOLATION RATE �' 3 (minutes/inch) PERC HOLE DIAMETER TEST RUN BETWEEN 3 FT AND 7 FT Eagle River Englneering Services ox 773294 PERFORMED BY: Eagle RiVer, AK 95577 CERTIFY THAT THIS TEST WAS PERFORMED IN 694-5195 ACCORDANCE WITH ALLSTATE AND MUNICIPAL GUIDELINES IN EFFECT ON THIS DATE. DATE. Eagle River Engineering Services Louis Butera, P.E. P.O. Box 773294 Eagle River, AK 99577-3294 RESIDENTIAL WELL FLOW TEST (907) 694-5195 tel (907) 694-3297 fax LEGAL: Proposed Lot 75A of Eldred Subdivision, presently Lot 75 T15N, R1 W, Sec.8 SM LOCATION: McKinley View Ave., Chugiak AK. OF A OWNER/CLIENT: Eldred TYPE OF WELL: Private " 491N! PA WELL LOG AVAILABLE: No 4• •- Louis A. Buten ON �' "% CE4736 WELL PRODUCTION RATE: 0.35 GPM for 4 hours or 504 Gallons per Day , � Ql�•...•••••••P�,"w® DATE OF TEST: 11-18-98 % %'��"�� COLIFORM/NITRATE WATER QUALITY SAMPLE TAKEN: Yes WATER TEST RESULTS: Pending TEST PROCEDURE At the start of the test the well was pumped at a average flow rate of 7 GPM. Total water level drawdown from a static water level of 77 feet was 106 feet after 40 minutes of pumping. At this point the water surface level in the well was static at 183 feet below the top of the well casing and at the level of the water pump. With the use of a sonar and calculation of total water amount for drawdown cycle, recovery rate of the well was monitored and calculated at an average rate of .45 GPM for the first stage of recovery. The well flow was then set at this rate and allowed to flow for 85 minutes. The well could not maintain this flow rate and another recovery was monitored from the 183' to the 168' level. This recovery indicated a rate of less than 0.40 GPM. The well was then flow tested at an average rate of 0.38 for one hour. Subsequent recovery readings indicated a 0.35 GPM recovery. This yield or recovery rate is a maximum rate and may decrease as the well is recovering. TEST RESULTS The well yield or recovery rate meets the basic requirements of the Municipality of Anchorage for a 3 bedroom single family residence as of the day the system was tested. The well will require the casing be extended 1 foot, a proper well seal be installed and the wires from the ground to the well seal be placed in an electrical conduit. The assessment of the condition of this well applies only to the conditions as of this date. The flow rate of any well may change due to subsurface conditions that may not be observed from the surface, changes in land use and other factors that may impact the conditions of the aquifer supplying the well. There is no guarantee that the well system tested will meet the requirement for approval in the future. The test data and investigation of existing conditions is provided to our client for submittal to the Municipal Health Department for their review and approval. Any concerns with this test report should be discussed with the testing engineer. If it is requested, we will submit the report directly to the Municipality. \1998\98 -069 -rpt Page 1 of 1