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Home My WebLink AboutDON JACK Lots 1-3 Tract A S-5345 MUNICIPALITY OF ANCHORAGE DEPARTMENT OF HEALTH & ENVIRONMENTAL PROTECTION ENVIRONMENTAL HEALTH CASE REVIEW WORK SHEET [] PLATTING BOARD [] PLANNING & ZONING CASE NUMBER S-5345 DATE RECEIVED April 2, 1980 NAME 1, 2, 3 and Trzct A Don Jack COMMENT TO PLANNING BY April 14, 1980 Subdivision FOR MEETING OF CASE OF ~j~lC WATER~LQ.T..AVAI LABLE TO PETITION AREA ~"PUBLIC SEWER NO,___T.T AVAILABLE TO PETITION AREA REVlEWER'S COMMENTS: 71-014 (Rev. 2/78) MUNICIPALITY OF ANCHORAGE DEPARTMENT OF HEALTH & ENVIRONMENTAL PROTECTION ENVIRONMENTAL HEALTH CASE REVIEW WORK SHEET [] PLATTING BOARD [] PLANNING & ZONING CASE NUMBER S-5316 DATE RECEIVED January 3r 1980 COMMENT TO PLANNING BY January 21, 1980 NAME ~ Don Jack Subdivision FOR MEETING OF CASE OF [] PUBLIC WATER NOT AVAILABLE TO PETITION AREA [] PUBLIC SEWER NOT AVAILABLE TO PETITION AREA REVIEWER'S COMMENTS: 71-014 (Rev. 2/78) unicipality of Anchorage MEMORANDUM DATE: July 11, 1980 TO: John Lynn, DHEP "t FROM:. .Jo Ann ¢6ntrera Planning Department SUBJECT: Don Jack Subdivision S-5316 & S-5345 This is a memo to verify that Don Jack Subdivision has preliminary approval from the Platting Authority and has been submitted by the engineer for final filing. 91-010 (5/78) 4040 "B" STREET ANCHORAGE, ALASKA 99503 (907) 278-1551 June 10, 1980 W.O. #A19294 Mike More SRA Box 473-J Anchorage, Alaska 99507 Re: Perc Test Lot 3, Don Jack Subdivision Dear Mr. More: We ran a percolation test in the test hole cased with slotted plastic pipe on the above referenced lot. The test hole had previously been drilled and logged by Jim Dowling°of Dowling and Associates. The test hole was saturated, left overnight, saturated again and the rate the water dropped in the test hole monitored over a period of one hour, at ten minute intervals. The percolation rate measured was 5.0 minutes/inch. Please feel free to contact us should' you have any questions. ~~.~ /.~/,//i~~fl ~ ~ Very truly yours, MRN/mg /~~~~ ~'~ · ~ Manager GEOLOGIC SOIL INVESTIGATION of NWl/4 NE1/4 NWl/4 SE1/4, Section 3, T11N, R3W, S.M. REFERRED TO AS DON JACK SUBDIVISION Updated to include Lot 3 and Tract A Prepared by: DOWLING AND ASSOCIATES 804 East 15th Ave. Suite 2 Anchorage, Alaska 99501 December 1979 (REVISED May 30, 1980) TABLE OF CONTENTS INTRODUCTION SITE DESCRIPTION SUB-SURFACE SOILS AND CONDITIONS CONCLUSIONS SOILS LOCATION MAP LOGS OF TEST HOLES ADDITIONAL INFORMATION INTRODUCTION This report is the result of a field t'rip investigation conducted on And May 28, 1980 December 21, 1979 on the proposed subdivision. This area is located within Section 3, T11N, R3W, S.M. Alaska, generally about 1600 feet West along 164th from Golden View Drive. This subdivision is a further subdivision of alloquit parts lands (2.5 Plus an additional 6.25 acres acres into two 1.25 acre lots). The subdivision is planned exclusive of public water and public sewer. The Don Jack Subdivision is a newly proposed subdivision surrounded by basically unsubdivided lands. It is located on a hillside facing to the west. Development of adequate sanitary facilities will be the responsibility of the individual property owners. The sewage disposal will consist of conventional septic tanks draining into a seepage pit and/or drain field. Drawings from the Department of. Health and Enviornmental Protection, Municipality of Anchorage have been included as a part of this report of the septic system required. The water source will be from individually drilled wells. The purpose of this report is to define the soils conditions within the property and to determine the area requirements for proper sewer seepage in that particular soil. SITE DESCRIPTION Don Jack Subdivision is located Off Golden View Drive about 1600 feet to the west on 164th Avenue. It consists of a 2½ acre parcel of land to be broken into two 1¼ acre lots. The land slopes gently to the west on the most of the lot. The easterly side of the lot has a somewhat steeper slope formed by a knoll. The land is in its natural state. It is covered with. Large Birch and Spruce with plush under brush consisting of willows, nettles and other small shrubs. The area seems to be a good setting for two units. Additional land for the subdivision adds 6.25 acres. This land is to the south and east of the original subdivision. The total parcel is basically the same as stated above for the smaller tract of land. SUB-SURFACE SOILS AND CONDITIONS The surface of the soils found in this area is a very dark brown humus topsoil with a lot of organic materials in the top 6 inches. The humus is from I foot to 1½ feet deep. This humus overlays a layer of sandy gravel or silty sandy gravel. The westerly portion of the lot is somewhat benched. The natural slope being to the west tends to substantiate that there is a bowl effect with the build up of topsoil within the bowl and exposed gravels (little topsoil on the breaks) on the areas where there seems to be more of a break. This bowl holds some surface water that will probably run off as soon as the dike is broken. The area is fairly consistant in that there is quite a bit of silty sandy gravelly material. Just where a person will encounter some of these layers of different materials will take some study of the overall hillside. The layer of gravel found in the upper level of test hole 2 seems to be the same gravel layer found at the lower level of test hole !. The water found in both holes in the upper layers is ground water and runoff from the hillside. It does not show up in the soils below to any avail. The soils in Hole I show a definite indication of silty conditions in the whole general area. The layer of pure silt would seem to be local and not consistant with silty sandy gravels found else where. The remainder of the hole to the 10.5 foot level would seem to be the basic soil of the area. The gravel at the bottom of the hole could be a pocket holding the water of it could be a layer extending into the hill where there would be basic water runoff from the upper hill. Hole #2 was taken at the top side of the bottom of the bowl effect explained before. The gravel was very clean of fines and at the bottom of this gravel was a small amount of water lying on top of the silty sandy gravel. This silty sandy gravel with rocks and boulders to 2' extended to a depth of 16 feet. The materials seemed to get harder as the depth increased. Whenever a boulder was encountered the digging got very hard, even though the boulder may have been only 1' on diameter. The hole was dry while digging in the lower depths with no indication of water to be encountered. There was no frost in either hole nor would frost be expected. There was also no bedrock nor would 'there be any expected. Additional InfOrmation acquired 28 May 1980 Test Hole #3 This hole was drilled with an au. ger suppl~ied by Denali Drilling. The Hole was placed in a location where the individual owner wishes to place his septic system. A 2" x 20' plastic pipe was placed in the hole when the auger was extracted. This pipe is to be used for a perk test. The soils were very dry. There was a l'ayer of gravelly sand between 4 and 7 feet.which should make for very good septic location. Material below 7 feet was all basically the same silty sandy graVel (hard pan) very dry and easy to auger through. A sample was taken from the bottom of the hole. Moisture content was quite low. The material would not ball-up when squeezed from lack of water content. There were more rocks at the top of the hole than at the bottom. It seemed that the farther the drilling the less rocks encountered. Test Hole #4 This holed was drilled with the same auger as hole 3. The hole was placed in a location where a septic system might be anticipated and a 2"x20' plastic pipe was placed in the hole for easy perk testing. The surface material gave way to very large rocks and boulders. The depth of the rocks extended to 5 feet. Very hard drilling materials. The material seemed to get smaller therdeeper the hole. Finally at a depth of 7 feet there seemed to be no mo~e rocks to hold up the auger. A sample was taken at the bo~om of the hole. No water was encountered in the hole a~d the material was quite dry all the way. CONCLUSIONS The two test holes on this property show that there is an inconsistancy in the layers of the soils, but they do show that the general type of the soils in the area is of a silty sandy gravel mixture (GM). I would expect to have some low percolation rates within the area unless a good layer of the gravel can be encountered where the septic tank is to be located. Specific information will have to be formulated at the specic septic tank location determined by the owner as to percolation and size of leech field. These holes display specific conditions encountered at the specific location; however, the sub-surface conditions are subject to major change. Based on the information obtained in these holes, it is felt that a specific location should be located for the septic system. If hard pan is encountered in the enti.re depth of the hole, percol~ation should be attempted before moving to another location abandoning the original hole. By searching and prudent judgement in the location of the septic system, a septic location should be available. If this criteria is followed these lots should be suitable for on-site sewerage disposal. Specific location will require an on-site permit from DEQ, Anchorage Office. The additional two holes taken 28 May 1980 show fair to good matemial for septic systems showing dry conditions and fair soils. The M of A should have the records for the ~ ~ septic system located on proposed Tract A. // ~ //James K. Dowling P.E. ~ J / / DOWLING & ASSOCIATES ~ (/ 804 East 15th Ave. Suite2 26 December 1979 v Anchorage, Alaska 99501 29 May 1980 (Revision) amp h'n .~ DOWLING & ASSOCIATES, Engineers -- Surveyors Anchoro~e, . Alaska Hole Mo / s*.~.~ , , /, . o~ ' ~ " Total Depth · ~/'; ~? ' Ground I'/~l~r Toble [:"" I. [)[SC,C( IP Y l ON Soil ;/pe~ color, texture, sump/ur dr/v/ny not=,& depths circ~l~lion lost~ ~o,~ on drilh~g eos% bH~ used, etc. Locoh'oo t,b.'es E Dx~2fom.. r.F'l '"ion .,9 droo. DOWLING & ASSOCIATES Engineers --. Surveyors ~nchoroge, . ,zllosko ~cot[on ethod Used '_old Perry __ Gootoeis; -?' . of... ; " Shee ; ~ Totol Depth '- ...... DESC,P/p £I ON .Poll ly.oe, co/or, texture, esfkm ate d p or,'icle sizea sarn,Her"drJ'~iT~,j note~t depths circu/et~On losS boles' on dril}in~ oos9~ bus u~ed, etc. Local:On [,'o,'es E ~ ........ ~ ................. ,~.: ~.."~ Vegel~l/o n .' Standard ,°cnelro;t:en Sampler Eriven ~../]'~0 lb. hammer, d$O~ drop. LOG OK I'EST h'OHING tie. w/It V Louasbury ~ ~ssociotes Engineers -- Surveyors ~nchoroge, . Alusk~ ~roject N~me, .ocot]on .. ~4ethod Used -'-~eld Party Veo~hsr . Somp ling DESCRIPTION est hn otc d p urh'cle Sompter drivh~g notes~ noh.,s on d~ ilhng eose~ VC'~lC luh u n .' >to le No. Sheet - Total Depth D~epth Ground Woter in Ft. l Time Locoh~n MO/cs cc D/~grom: ~ ?~ble 30'* dron, ,.? ComDIeted · Wect No ~"rr'P - J'~' O .z~nchoroge, . Alos~'o .%'m,o h'n9 Goolo~ist Ground IValor Toble DI~SCRIP£10H Soil type, color, texture, eslimoted porh'clo size~ $orn,9/e~* driving ootes~ dopths circulation Iost~ notes on drilling oose~ bils used, otc. LO¢OIIO0 [}O/os ,Test Hole Lo~l - Description Guide ~e soil descriptions shown on thc logs are the best estimate of the ~oil's ,.aractcristics at thc time of field examination and as such do nat achieve the cession of a laboratory testing procedure, if the log includes soils samples, ose samples receive an independent textural classification in the laboratory verify the field cxaminatmn. logs often include the following items: D.~th interval - usually shown to 0.1 foot, within that zone no sign~tge m soil type was observed through drill action, direct observation or sampling. Frost Classification - NFS, Fl, F2, F3, F4, see "Soil Classification Chart" Texture of Soil - An engineering classification of the soils by particle stze and proportion, see "Soil Classification Chart", note the proportions .,re approximate and modifications to the soil group due to stratit'tcatiou, inclusions and changes in properties are included. Moisture t:ontt'nt this is a qualitative measure: dr__..v.. ,,,, or little apparent surface moisture, damp, moisture forms portion of color, tess than plastic limit, wet, uo frec water, often soft, il'cohesive soil, saturated, free water may be squeezed out, if a free draining soil; ddatent at natural moisture content, if.a non-plastic silt or fine saud. (]'he moisture content is further defined by reference tu LW, NP, M%or dilatency.) Density -- refers to more-or-less non-cohesive soils, such as sandgrayel mixtut~.'s with or without a fine fraction, derived from drilling action and/or sample data: usually described is: very loose, loose, medium dense, very dense. General intent is to portray earthwork character itl its. Stiffness - refers to more-or-less cohesive soils and fine grained silts of ~ clay-silt groups. Derived from drill action and/or sample data, Very soft, soft, stiff, very stiff and hard are commonly used terms. Particle ~ize -- Tile largest particle recovered by the split spoon is 1-:3/8", Shelby tube Y', auger flights /minute-man) 2", Auger flights (1'550 hollow stem) 6'.8", Larger particles are described indtrectly by action of tit,: drdling and are teferrud to as cobbles, Y' to 8", or boulders 8"+. Therefore when reviewing the gradation sheets, if any, the description on the hole log must bt considered for an'indication of larger particles. Unified Soil Classification - This is a two letter code. See Unified Clasfification ~hect 1'o"7']'~her definition. In some cases AASHO and/or FAA soil classltications may be shown as well as the uni/ied. Atterberg Limits - useful for fine grained and other plastic soils, PI; natusal moisture content believed to be less than plastic limit natural moisture content believed to be between plastic and liquid ~-; natusal moisture content believed to be greater than liquid limit . NP; non-plastic, useful as a modifying materials. description of some silty Dilatencv - is the ability of water to migrate to the surface of a laturated or nearly saturated sod sample when vibrated or johed -- used as an aid to determine il' a fine grained soil is a slightly or non-pla,tic silt or a volcanic ash. Rock flour - finely ground soil that is nut plastic but otherwise appears ilm r---~a clayey silt. Organic Content - usually described as Peat, PT, sometimes includes disi:rei~ partic']~ such as wood, coal, etc. as a modifier to .tn inorgamc soil. Quantity described as', trace, or an estimate of volume, or, in case of all organic, - as Peat. This may include tundra, muskeg and bog material. Muck - a modifier used to describe very soft, semi-organic deposits u~u-'~ly occuring below a peat deposit. ~A,rnorphus pear -. organic particles nearly or fully disintegrated. Fibrous Peat - organic particles more-or-less intact. Bottom of Testhole - includes last sample interval. Frost Line - seasonal frost depth as described by drilling action and/or samples at the time of drilling. Frozen Ground - other than frost line, described by samples, usually includes description of ice content, often will include modified Unified Classification for frozen soils - this is a special case related to permafrost studies. Free Water Level - The free water level noted during drilling. This is not necessarily tile static water table at thc time of drilling or at other seasons. Static water tahle determination m other than very permeable soils requires observation wells or piezometer installations, used only m special cases. J'~low/6" -. The nu,nbcr of blows of a 140 weight free falling 30" to advance a 2" split spoon 6"i the nurnber of blows for a 12" advance is. by definition, thc standard penetration. ,4% - natural moisture content of the soil sample, usually not p-~"rformed on clean sands or gravels below the water table, Type of Sample .- S__P, rcte~s to 2" split spoon driven into the soil by 140 pound weight, a disturbed sample, S, thin wall tube, "Shelby" used to obtain undisturbed samples of fine grained soil, C,, "grab" disturbed sample from auger flights or wall of trench, .G., cut sample, undisturbed sample from wail of trench. Dry Strength - a useful indicator of a soil's clayey fraction, N=None, L=Low, M=Medium, H=High - The samples are placed into apparently similar groups based or and texture and are arbitrarily assigned a group '.etter, Further disturbed tests including Atterberg Limits. grain ~ize, moisture-density relatiom;htp, etc. may be performed on the group and are assumed to reflect the general di~trubed characteristics of the soils assigned ~o group. 'l'hN ~ an important phase of thr sod analysis and *s u~cd ~tandardize the varmus qualitative determinations and to reduce the number of quantitative tests necessary to describe the ~uiJ mall. SOIL CLASSIFICATION CHART 30% GRAVEL CLAY ~/ / ,? CLAYEY ,? CLAYEY CLAYEY CLAYEY \ OR OR SILTY SILTY SILTY SILTY SAND GRAVEL GRAVELLY SAND SANDY GRAVEL \/ / \/ \ \/ / SAND GRAVELLY SAND SANDY GRAVEL GRAVEL \ \ \ ~ \ \ 0 10 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 15% FINER THAN 0.02 nlm. F3 a, GRAVELLY SOILS CONTAINING MORE THAN 20% FINER THAN 0.02 mm. AND SANDY SOILS (EXCEPT FINE SILTY, SANDS) CONTAINING MORE THAN J5% FINER THAN 0.02 mm. b, CLAYS WITH PLASTICITY INDEXES OF MORE THAN t2. EXCEPT VARVEDCLAYS. F4 a. ALL SILTS INCLUDING SANDY SILTS. b, FINE SILTY SANDS CONTAINING MORETFtAN 15% FINER THAN 0.02 mm. c. LEAN CLAYS WITH PLASTICITY INDEXES OF LESS THAN 12. d. VARVED CLAYS, LL~ Itli1 itl Il I ~.~ '~---------~ 4- Municipality of Anchorage DEPARTMENT OF HEALTH & ENVIRONMENTAL PROTECTION PRE-INSPECTION CHECK SHEET 264-4720 MINIMUM CJ LEVEL 4" CAST IRON SIPHON SEPTIC / PiPE WITH AIRTIGHT / Crib or Log TANKi'"~'~ .~-~'~" CAPS [] '"-...h~l, 'CAST O TO O 0 0 , ' i5' MINIMUM TO EDOEOF EXCAVATION U~ '-1 CAST iRON REQUIRED WHENEVER LINE CROSSES UNDER DRIVEWAY[] GRAVEL BACKFILL [] CRIB 4' MINIMUM ABOVE WATER TABLE [] 6' MINIMUM ABOVE BEDROCK~ MINIMUM WELL DISTANCES: INDIVIDUAL TO TANK 100"E3 TO PIT 100' Q NO SEWER LINE 10'[] PUBLIC - Under 25 Service or Less Than, 15 Connects TO TANK 100' ( ) TO PIT 150' 75'-100' ONLY CAST IRON SEWER LINE PUBLIC -'Over 25 Service or More Than 15 Connects TO TANK 200' ( ) TO PIT 200' ( ) 100'-200' ONLY CAST IRON SEWER LINE !00' NO SOURCE OF CONTAMINATION NOTE: 100'MINIMUM FROM TANK AND PIT RIVER, LAKE OR STRE~t ( ) Individual 4" SEWER LINE [] CONSIDER DISTANCE TO AREA WELLS & SEWER SYSTEMS ~ PiT EXCAVATION BASED ON SOILTEST [] SEPTIC TANK MUNICIPALITY APPROVED [] HOUSE INLET & OUTLET MUST 5' BE WAIERTIGHT SEPTIC TANK GRADE: 2'PER100'O~ ¼" PER FOOT EXCEPT I PRECEEDING TANK AN SHOULD NOT EXCEED B" PER 100' ON FL TERRAINS [] SEEPAGE PiT SEEPAGE PIT CRIB SCREENED ½" - 2%" GRAVEL 20' MINIMUI~I TO NEAREST LOT LINE [] ~ §9.79 ~ 59.8:5' (R) PLAT 78-294 IO',TELEPHONE ~ ELECTRIC EASEMENT N O0° .10 (R) N O0e 08\3 BASIS OF~ BEARINGS PLAT