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HomeMy WebLinkAboutEKLUTNA GATE S-7417I I ~ MUNICIPALITY OF ANCHORAGE ) DEPARTMENT OF HEALTH & ENVIRONMENTAL PROTECTION ~ ~ Environmental Health Division CAS. R.V,.W CASE NUMBER: i DATE RECEIVED: COMMENTS DUE BY: S-74~7 i December 29, 1983 ~ January 20, 1984 SUBDIVISION OR PROJECT TITLE: \ Lots 6 - 10 Eklu%n& Gate Subdivision (T16N R1W Section COMMUNITY WATER AVAILABLE COMMENTS: -, December 27, 1979 W.O. #D12023 Area 1 Habitat North P.O. Box 2240 Anchorage, Alaska 99510 Attention: ~. Mike Jones Subject: Subsurface Investigation for Proposed Eklutna Housing Project Located Within the Southeast 1/4, Section 24, Township 16N, Range 1W, Seward Meridian, Alaska Gentlemen: The following are the results of subsurface investigation conducted on the subject site on December 19 and 20, 1979. The purpose of this investigation was to determine the feasibility of on-site wastewater disposal systems and to provide subsurface information to aid in the design and construction of roads .and utilities. Subsurface exploration was conducted by means of tractor mounted backhoe. The test pits were logged and located in the field by Tom Williams and Joe Millhouse, geologists with Alaska Testiab. Excavation was performed by Erickson's Backhoe Service of Chugiak, Alaska. As the test pits were excavated the g~ologist visually classified the soils and took samples of important horizons. With the exception of large cobbly samples, these were sealed in plastic bags to protect the natural moisture content. Samples returned to the laboratory were visually classified and mcisture content and dry strength determined. Samples of similar color, texture and particle size distribution were grouped together and given an arbitrary group designation. Grain size analysis was performed on a composite sample of the important group rather than on individual samples. The site may be roughly characterized as having two soil horizons. The surfici~! layer, which varies from about one to five feet in thickness, consists of interlayered sand, gravel and occasional organic siic. The thickness and composition of this layer ~s highly variable between tess pits. The second horizon is very uniform among the test pits. It consists of well graded sandy gravel with cobbles. This material is present below the surficial layer in all test pits and is the predominant soil on the site. Habitat North · December 27, 1979 Page Two The various group designations given on the test ~hole logs are described below. Group A - is a gray Gravell~ Sand. ~This group is non-frost susceptible, rate~ NFS. Its unified Classification is SW. Group A consists of two samples. Group B - is a brown ~ fine Sand containing some roots and organics. ~his group is frost susceptible, rated F-2. Its Unified Classification is'SM. Group B consists of two samples. Group D - is a brown Silty fine Sand. This group is highly frost susceptible rated F-2/~. Its Unified Classification is SM. Group D consists of two samples. Group E - is a brown to gray Sandy. Gravel with cobbles. This group is non-frost susceptible, rated NFS. Its unified Classification is GW. Grain size distribution is shown on Sheet 4. Group E is the predominant soil on the site and is the group present'at the depths critical to operation of septic tank drain fields. Group E consists of 11 samples. Group I - is a brown Sandy Silt with organics. This group is highly frost susce-~-~ble rated F-4. Its Unified Classifi- cation is ML to OL. Group I consists of two samples. No percolation test was performed with this study. Based on the characteristics of Group E, seepage pits and drain fields may be sized using a minimum absorption area of 85 square feet per bedrOom. No groundwater table was encountered during the exploration. The only frozen soil encountered was seasonal frost within the roadway. The following figures and tables accompany this report. Vicinity Map Test Hole Location Sketch Test Pit Logs Standard Explanatory Information Grain Size Distribution Curve Figure 1 Figure 2 Tables A-E Sheets 1-3 Sheet 4 'Habitat North December 27, 1979 Page Three We trust the above meets your present requirements. If there are any questions please do not hesitate to contact us. Very sincerely, DICKINSON-OSWALD-WALCH- LEE R. Mark Hanson, P.E. Approved by: Melvin R. Nichols, P.E. Alaska Testlab Manager RMH/mg Attachments '"': ALASKA JIR o[lmEnTAL CO[1TROL {~nqin~¢rinq f.,. {~nuironmentnl Studies May 3, 1984 SOILS FOR EKLUTNA G~TE SUBDIVISION BACKGROUND: This area lays just east of the Eklutna interchange of the GI~ in the north part of the Municipality of Anchorage. The area a general flat plain area and is located between the Glenn Highway and the Alaska Railroad. It is a new area that is being subdivided for additional housing. vegetation on the area is predominately large cottonwood interspursed with spruce. The south portion of the area contains a heavy growth of spruce and appears to have been formerly cleared. The top soils consists mostly of organic debris and sand. The under material is made up of mostly water deposited gravel and sand. Only at the very deep areas does silty, sandy gravels occurred. DISCUSSION: Test were performed in conjunctions with the requirements set forth "Design Manual for On-Site Waste Water Disposal System" EPA. Testholes were dug with a Ford rubber tired backhoe on May 1, 1984. Testholes were not able to be dug deeper than 11 or 12 feet during this test. Th gravel material was very loose and the hole tended' to sluff in with depth. The objective of our testing was to determine the soils suitability for on-site septic system. The important soils classification are: 1). Soil depth ~ 2). Depth to ground water. 3). Soil permeability The individual testhole soils logs are attached in the appendix. Shallow soil: Results of our testing indicated that bedrock depth were not obtained anywhere within the area. From the geolocial formations available it would appear that bedrock is not a factor in this area. Soil-Water: None of the test holes showed anY ground water. The only moist soils found were near the 12 foot depth and these were occassional layers of silty sandy gravels (GM). These soils were slightly moist but no free water was in that soil structure. Soils Permeability: All the soils in the area are highly permeable and should not create any problems with the imstallation of on-site sewer systems. In several instances we noticed layers of organic material (root mass) at depth below that which would normally be be found. It would appear that this area has been overlaid with gravel several times in the recent geologic history. The root masses were in sandy material and we feel that this will not inhibit permeability. Conclusions: Based upon our ~oils we feel that all the lots are 1200 I. Uest 33rd Au~nue, Sui(¢ B · Anchorog¢, Atoskn 99~3 · {907) 276-1361 acceptable for on-site sewer systems'. Deep trenches or five foot wide shallow drainfields are recommended in this area. Because of the looseness of gravel a five foot wide shallow alternate maybe necessary in some cases. Approved by, ~d~u$ point estobhshed record dist. ~80-1761 from P.K found in stump S.W corner Lo! Is 'Block I I~ record stonces (P80-176) from rebor found south P.C of Lotl, Block l curve turn r N 83~28 '00 "E ~5. 00' ' Meos' ~ [N 82~~R-''~' - 25 6 ~81 Sq. Ft. 079 Sq. Ft. LIRE ESilT O0~' 24, 485 Sa. Ft. N47'o.pT"ii"W ~. PERFORMED FOR: LEGAL DESCRIPTION: 2 3 4 5 6 7 8 9- ~IsP ) I MUNICIPALITY OF ANCHORA~GE i', ~ DEPARTMENT OF HEALTH AND ENVIRONMENTAL PROTECTION 825 L. Street, Anchorage, Alaska 99501 264-4720 SOILS LOG-- PERCOLATION TEST SLOPE I [] PERCOLATIO~ TEST 10- 11 12 13 14 15 16 17 18 19 6obbl¢ ~,// WAS GROUND WATER E.CO~NTERED? ~0 ~ 0 P E 'IF YES, AT WHAT DEPTH? 20 COMMENTS PERFORMED BY: 72-008 (6/79) Gross Net Depth to Net Reading Date Time Time Water Drop PERCOLATION RATE ."~.~_~ ~ '' + ~ nk~fe~/i,nch) TEST RUN BETWEEN .'(~j~'AND . ~ ,, PERFORMED FOR: LEGAL DESCRIPTION: 1 2 3 4 5 6 7 8 9 I MuNiCIPALITY OF ANCHORAGE DEPARTr~NT OF HEALTH AND ENVIRONMENTAL PROTEtCTION [] TEsTPERCOLATION 82~ L. Street, Anchorage, Alaska 99501 264-4720 /~ILS LOG - PERCOLATION TEST DATE PERF SLOPE SITE PLAN ~O+ 10 11 12 13- 14- 15- 16 18 19 2O COMMENTS PERFORMED BY: 72-008 (6/79) WAS GROUND WATER ~ 0 t ENCOUNTERED? ~F YES, AT WHAT / E DEPTH? 4- Gross Net Depth to Net Reading Date Time Time Water Drop PERCOLATION RATE TEST RUN BETWEEN I MUNICIPALITY OF ANCHORAGE DEPARTMENT OF HEALTH AND ENVIRONME~JTAL PROTECTION 825 L. Street, Anchorage, Alaska 99501 264-4720 SOILS LOG- PERCOLATION TEST ~ SOILS LOG [] PERCOLATION TEST PERFORMED FOR: LEGAL DESCRIPTION: 2 3 4 5 6 7 8 9 10 11 '12 13 SLOPE SITE PLAN I WAS GROUND WATER ~,~ I u. ;~ ENCOUNTERED? ~"lO -~) bom ~ · IF YES, AT WHAT ~"~ I ~_.. DEPTH? Gross Net Depth to Net Reading Date Time Time Water Drop PERCOLATION RATE ,' m '>' ~ ; ~ , (minut'e~/inchl TEST RUN BETWEEN ~r¢ AND ~ ,;;FT ,, - .'.~ .... ~, ~.,~ ~/." ,, ,/., ~,'~ j ~dde~ CERTIFIEDBY: ,' /:. TL"''~ , , ,,~ i DATE: 14 15 16 17 18- 19~ 20- COMMENTS PERFORMED BY: 72-008 (6/79) PERFORMED FOR: LEGAL DESCRIPTION: 2 3 5 6 7 8 9 10 11 12 13 14 15- 17- 18- 19- 2O COMMENTS I MUNICIPALITY OF ANCHORAGE DEPARTMENT OF HEALTH AND ENVIRONMEI~ITAL PROTECTION SOILS LOG ';';~" . 't PERCOLATIOI~ '~t TEST 825 L. Street, Anchorage, Alaska 99501 264-4720 ~ ~ /~ D · ~,~ .~o.~ - SLOPE SITE PLAN~ ~ ~:,. %'/sa. .aRFORMED .¥: "t?¢,'Cl / J~ ss, 72-008 (6/79) I/-I','-I f / I,..' '1 I 111/I I I II-rt I I Iilll /. I Il\Il \ [] WAS GROUND WATER S ENCOUNTERED? P 'IF YES, AT WHAT DEPTH? Gross Net Depth to Net Reading Date Time Time Water Drop PERCOLATION RATE CERTIFIED B~'~ ATE DATE: MUNICIPALITY OF ANCHORAGE DEPARTMENT OF HEALTH AND ENVIRONMENTAL PROTECTION 825 L. Street, Anchorage, Alaska 99501 264-4720 SOILS LOG- PERCOLATION TEST ~,~ SO/LS LOG w [] PERCOLATION TEST · '. PERFORMED FOR: LEGAL DESCRIPTION: t 2 3 4 5 6 7 8 9 DATE PERFORMED: SLOPE SITE PLAN r_q 10 11 12 13 14'- 15- 17- 18- 19- 20- COMMENTS PERFORMED BY: 72-008 [6/79) , WAS GROUND WATER ENCOUNTERED? ' rFYES. ATWHAT DEPTH? Gross Net Depth to Net Reading Date Time Time Water Drop PERCOLATION RATE .... ' ~- ·. ~ ~ ' * ~ (~mutesl~nchl TEST RUN BETWEEN , L~ ~;'~-~ AND '~ ~;,T.}~ ~, DEPT. OF ENVIRONMENTAL CONSERVATION SOUTHCENTRAL REGIONAL OFFICE 437 "E" STREET, SUITE 200 ANCHORAGE, ALASKA 99501 August 17, 1984 Triad Engineering Planning & Surveying 6937 Old Seward Highway Anchorage, Alaska 99502 Dear Sir: RILL SHEFFIELD~ GOVERNOR Telephone: (907) Address: 274-2533 NOI.tO~U.O;N~ I¥.[NF~!A!No;~IAN~i Hll¥~H ~0 '.[d~Q =IOVNOH3NV :~O A.I.IIYdI~)INFI~ Subject: Eklutna Gate S/D Water Improvements, Eklutna 8521-FA-038 PWS # 213019 We have reviewed the plans and specifications for the subject project. Enclosed with this letter is a "Conditional Certificate To Construct" for the drinking water system. The "Approval to Operate" section of the certificate must be completed by a representative of this Department prior to placing the system in operation. It should be remembered that final approval will necessitate the submission of Engineer As Built Plans. This will consequently mandate that a private professional engineer conduct basic inspection of this oroject so as to be able to sign off on as built plans. Arrangement for this inspection work is the responsibility of the developer. Siyerely, ~-- Envi roamental Engineer BEE/dd Enclosure ;KA ~CONSERVATION D3 OPERATION C ERTl FICATE approved. }ndltlonally approved. (see attached c~ndltlons).' ~4 ? ~./ ~ ~ ~ TITLE, public, water system located Alaska, submitted In accordance with 18 AAC 80,100 · have been reviewed and are DATE started within,two,years.of, the approval/date, this certificate is void and new pla,ns and ~mltted. for~revlew and approval before construction, ORDERS ~,::;,~,:.,., .. Approved by Date TO OPERATE ~I~ROVAL TO OPERATE" section must be completed a~d signed by the Department before any water the public. truotlon of the public water system was completed on (date), The system is hereby ranted Interim a 3proval to operate for 90 days following the completion date. TITLE I DATE submitted during the Inter m approva, period, or an Inspection by the Department, has confirmed ~g to the approved plane, The system is hereby granted final approval to TITLE ' DATE DISTRIBUTION: 1. WHITE - ENGINEER [Complete Section C) 2, YELLOW · WATER SYSTEM FILE IComplete Section C) 3. PINK - ENGINEER/MUNI-SOROUGH ¢Complete Section C) 4. GOLDENROD · MUNI.BOROUGH (Complete Section A) Tes~ Hole Table A ~. #D12023 Date: 12/20/79 Logged by: J. Millhouse Depth in Feet From To 0.0 1 .0 1 .0 2.0 · 2.0 2.5 2.5 3.0 3.0 4.5 4.5 5.0 5.0 11 .0 Bottom of Test Hole: Frost Line: Free Water Level: Sa. No. Depth I 1.5 2 2.0 3 2.5 4 4.0 5 4.5 6 6.0 Soil Description F-4, brown Peat and roots, damp, soft, Pt NFS, brown Grave,l, ly Sand, damp, subrounde/~ particles to 1/2 , S%~----- F-2, brown organic Silt}, fine__Sand, dam~, NFS, brown Gravell~ Sand, dam~ NFS, brown Sandy Gravel, dampg~ F-4, brown organic S~andy Silt, damp, ML NFS, brown Sandy. Gravel wit and cobbles, damp rounde particles to 12", ~W 11.5 Feet Observed Obf~ved ~hile ~r ~; ype of Dry ~% ~/~SamDle Strength Group Unified 2.1 G N A SW 23.1 G N B SM 3.4 G N A SW 2.7 G N -- SP 30.3 G L D SM -- G N E GW Remarks: 1. 3. 4. 5. 6. Type of Sample, G=Grab, SPT = Standard Penetration, U = Undisturbed. Dry Strength, N=None, L=LOW, MmMedith~, HmHigh. Group refers to similar material, this study only. General Information, see Sheet 1. Frost and Textural Classification, see Sheet 2. Unified Classification, see Sheet 3. Test Hole ~2 Depth in Feet From To 0.0 0.4 0.4 2.0 2.0 4.4 / Bottom of Test Hole: Frost Line: Free Water Level: Sa. No. Depth 1 2.0 2 3.0 3 4.5 4 5.0 5 10.0 Table B D~e: 12/19/79 . / IJogged by: T. Willies / \ Soil Description Peat with roots, Pt /J NFS, gray Sand~ Gravel, damp, GW ~ F-2, brown Silty Sand, damp, SM ' F-4, brown Sa___a~ Silt,, damp, SM NFS, gray Sand!/\Gravel, well graded, many cobbles, damp,~'~lrtlcles ~7 , G ll.41Feet 1 \ ~*~ ' 4.6 ~eet \1 ~ ' //// None~Observ~ ~il~cXavating ~ ~ T'. ~ ~f Dry Blows/6" ~ ~ ~ S~ren~th Group, Hn~f ~ed 4.3 G N E GW 6.4 G N E GW Remarks: 1. 3. 4. 5. 6. Type of Sample, G=Grab, SPT = Standard Penetration, U = Undisturbed. Dry Strength, ~N=None, L=Low, M=Medium, }{=High. Group refers to similar material, this study only. General Information, see Sheet 1. Frost and Textural Classification, see Sheet 2. Unified Classification, see Sheet 3. Test Hole #3 Table C WO $D12023 Date: 12/19/79 Logged by: T. Williams Depth in Feet From To 0.0 0.5 0.5 I .0 1.0 1 .4 1.4 2.4 2.4 3.7 3.7 4.4 4.4 4.9 4.9 11 .1 Soil Description Brown Pea~., damp, Pt NFS, brown Gravelly Sand, damp, SP NFS, brown Sandy Gravel, damp, GP NFS, brown Sand, damp, SP NFS, brown Sandy Gravel, damp, GW NFS, brown Gravelly Sand, damp, SW F-4, brown Sandy. Silt , NFS, gray Sand~ cobbles, damp, Bottom of Test Hole: Frost Line: Free Water Level: Sa. No. Depth 1.1.1 Feet None Observed None Observed ~..Exc. Type o~ Dry Blows/6" M% Sample Strength Group. Unified 1 0.5 2 1.0 3 2.0 4 3.0 5 4.0 6 4.5 7 6.0 8 10.0 .16.4 G 4.1 G 4.3 G 3.7 G 3.9 G 27.2 G 3.0 G 5.8 G N -- SP N -- SW N E GW N -- SW L I ML/OL N E GW N E GW Remarks: 1. 3. 4. 5. 6. Type of Sample, G=Grab, SPT = Standard Penetration, U = Undisturbed. Dry Strength, N=None, L=Low, M=Medium, H=High' Group refers to similar material, this study only. General Information, see Sheet 1. Frost and Textural Classification, see Sheet 2. Unified Classification, see Sheet 3. Test Hole #4 Table D .~0 #D12023 Date: 12/20/79 Logged by: J. Millhouse Depth in Feet From To 0.0 1 .0 I .0 10.0 Soil Description Brown Peat and plants, damp, Pt NFS, brown Sandy Gravel, well graded, many cobbles and boulders, damp, subrounded particles to 12", GW Bottom of Test Hole: Frost Line: Free Water Level: 10.0 Feet None Observed None Observed While Excavating Sa. Depth 8.0 Type of Dry Blows/6" M% Sample Unified -- G GW Remarks: 1. 3. 4. 5. 6. Type of Sample, G=Grab, SPT andard Penetration, U = Undisturbed. Dry Strength, N=None, L=Low M=Medium, H=High. Group refers to similar mati rial, this study only. General Information, see Sheet 1. Frost and Textural Classification, see Sheet 2. Unified Classification, see Sheet 3. Te~st Hole #5 Table E NO ~D12023 Date: 12/20/79 Logged by: J. Millhouse Depth in Feet From To Soil Description 0.0 1 .5 1.5 3.5 3.5 4.5 Brown Peat, Pt/OL NFS/F-2, brown slightly organic Sand~ Gravel with many cobbles, damp, GW F-4, brown organic Sandy Silt, damp, /OL 4.5 11.5 NFS, brown ~ Gravel_, well gra, cobbles and boulders, damp., GW, Bottom of Test Hole: Frost Line: None Observed \~ ' ' Free Water Level: None Observed Whi~e Excavating Sa. No. Depth 1 1.0 2 2.0 3 4.0 4 10.0 Remarks: 1. e 3. 4. 5. 6. Type of Dry Blows/6" M% Sample Strength Grou~ unified 29.2 G N/L -- OL 5.5 G N E GW 27.5 G L I ML/OL -- G N E GW Type of Sample, G=Grab, SPT = Standard Penetration, U = Undisturbed. Dry Strength, N=None, L=Low, M=Medium' H=High' Group refers to similar material, this study only. General Information, see Sheet 1. Frost and Textural Classification, see Sheet 2. Unified Classification, see Sheet 3. SOIL CLASSIF'ICATjON CHART 30% GRAVEL CLAY CLAYEY \ OR SILTY SAND Ct CLAYEY SILTY SILTY GRAVELLY SAND SANDY GRAVEL \ CLAYEY SILTY GRAVEL SAND GRAVELLY SAND ,NDY GRAVEL \ \ \ 0 ! 0 20 30 40 50 60 70 80 90 100 GRAVEL (+~4 SCREEN) % BY WEIGHT NONFROST SUSCEPTIBLE SOILS ARE INORGANIC SOILS CONTAINING LESS THAN 3% FINER THAN 0.02 mm. GROUPS OF FROST-SUSCEPTIBLE SOILS: F1 GRAVELLY SOILS CONTAINING BETWEEN 3 AND 20% FINER THAN 0.02 mm. F2 SANDY SOILS CONTAINING BETWEEN 3 AND [5% FINER THAN 0.02 mm. F3 a. GRAVELLY SOILS CONTAINING MORE THAN 20% FINER THAN 0.02mm. AND SANDY SOILS (EXCEPT FINE SILTY. SANDS)'CONTAINING MORE THAN 15% FINER THAN 0,02 mm. · b~ CLAYS WITH PLASTICITY INDEXES OF MORE THAN t2. EXCEPT VARVED CLAYS. F4 a, ALL SILTS INCLUDING SANDY SILTS. b. FINE SILTY SANDS CONTAINING MORE THAN [5% FINER THAN 0.02 mm. c. LEAN CLAYS WITH PLASTICITY INDEXES OF LESS THAN 12. d. VARVED CLAYS.