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HomeMy WebLinkAboutHIGHLAND HILLS #1 General Information S-3565 DICKINSON OSWALD & PART NERS ENGINEERS AND SURVEYORS 800 CORDOVA STREET September 6, 1972 PHONE 907 277-168§ ANCHORAGE, ALASKA 99507 Hr. Rolf Strickland Greater Anchorage Area Borough Dept. of Environmental Quality 3500 Tudor Road Anchorage~ Alaska 99507 Re: Highland Hills Subdivision Dear Hr. Strickland: In accordance with our previous discussion about the above referenced subdivision, I made an on-site visit to review slope and soil conditions on the evening of September 5, 1972. Along the existing access road which passes through the property, I observed numerous cutbank conditions where from 3 to 20 feet of exposed cut existed. In one case, near the small stream which passes through the property in a northeasterly direction at the northerly i/4 of the property, there was a showing of exposed bed- rock ~ich had been broken off by a bulldozer operation during road con- struction. Other than this one indication, the remaining property seemed to be consistently sandy gravel with silt penetrations. The samples which were previously brought to our office by the subdivider and analyzed by Alaska Testlab would appear to be typical of the materials found throughout the subdivision area. From what I observed, I would not anticipate that there would be any property within Unit 1 of the subdivJsion which will not be found suitable for on-site sewage disposal. If you have further questions or would like to visit the site per- sonally, please call me and we will plan for further considerations. Very truly yours, DICKINSON-OSWALD & P~RS Haurice P. Oswald, Partner MPO:jp LEWIS E. DICKINSON, P.E. MAURICE P. OSWALD, L.$. KENNETH B. WALCH, P.E. FROM: DEPARTMENT: ...... ATED BY: GREATER ANCHORAGE AREA BOROUGH ,. : x-~'~ ~Z J DATE OF MEMO: /~ - . TO: DEPARTMENT: RECEIVER: REQUESTED ACTION SCHEDULE FOR INEORMATION ONLY FOR IMMEDIATE ACI'ION FOR YOUR CONSIDERATION OIHER DATE ANSWER REQUESTED: ................. PREPARE BACK-UP INFORMATION CALL ME BEFORE YOU ANSWER NEED v,~, , ~,UR RECOMMENDATION ALASKA TESTLAB ~ CONBUL?ATION ~ 'rESTING ,~ EXPLORATION ~ CHEMICAL © MATERI,~t "; F' I,N~,PECTION SOIL CLASSIFICATION CHART 30% GRAVEL N CLAYEY CLAY EY \ / OR SI LTY SAN D \ ~ILTY \ \ \ DY \GRAVE \ GRAVELLY SAND \ 0 I0 20 30 40 50 60 70 80 90 I00 GRAVEL (+-I~48CREEN) % BY WEIGFIT GRAVEL NONFROST SUSCEPTIBLE SOILS ARE INORGANIC SOILS CONTAINING LESS THAN 3% FINER THAN O.02mm. GROUPS OF FROST-SUSCEPTIBLE SOILS: FI GRAVELLY SOILS CONTAINING BETWEEN :5 AND 20% FINER THAN O.02mm. F2 SANDY SOILS CONTAINING BETWEEN 3 AND 15°/o FINER THAN 0.02mm. F3 a. GRAVELLY SOILS CONTAINING MORE THAN 20°/0 FINER THAN O.02mm. AND SANDY SOILS (EXCEPT FINE. SILTY, SANDS) CONTAINING MORE THAN 15% FINER THAN O.02mm, b. CLAYS WITH PLASTICITY INDEXES OF MORE THAN 12. EXCEPT VARVED CLAYS. F4 o, ALL SILTS INCLUDING SANDY SILTS. b. FINE SILTY SANDS CONTAINING MORE THAN 15% FINER THAN O.02mm. c. LEAN CLAYS WITH PLASTICITY INDEXES OF LESS THAN 12, d. VARVED CLAYS. !q?A 0 · '-? ~ -5 Dickinson-Oswa].d & Partners 900 Cordova Street Anchorage, Alaska 99501 ATTENTION: Mr. Oswald P:ROJECT: SUBJECT: Highland Hills Subdivision Materials Analysis 279-2581 Date: August 1 ~ 1972 W.O.: 15024 ./ ~-}~., (,,.,~. S ~lmp 1 e Data: 3 Samples received 28 July 1972 Gentlemen: Transmitted herewith are 'the results of sieve analysis Performed in our laboratory on the subject samples. The gradations have been plotted and may be fo~znd on sheets ' 2' th. rough 4 of 4 attached. If there are any questions in this regard, please contact our o:f lice. Very 't:ruly yours, KWB: ld MEMBER A LA $ !< A T f.: S-r,L./i .B CONSULTATION O 'i'ES'i I NG O E XPI.ORATION (; CHEIdlCAL O MATERIALS O INSP £CT!C,N SOIL CLASSIFICATION CHART 30% GRAVEL ~ 0 ~,./ CLAY EY CLAYEY / OR :: O/ t?'Y. SILTY ' % x \ ,: \ > \ oA ~D . \ / ./ \ . ~.\., . / x / ~RAVELLY ~&ND i, SANDY .GRAVE L /i'x ': /-k .4/ fx ~'X IX i- ~X /X :::. /X ~:.:::::;: : ' ~. / f / I:' ",: . ::' 0 I0 20 30 40 50 60 70 80 90 I00 NONFROST SUSCEPTIBLE SOILS ARE INORGANIC SOILS CONTAININ6 LESS THAN 3~/o FINER THAN O.02mm, 6ROUP8 OF FROST-SUSCEPTIBLE SOILS: FI F ~5 o. GRAVELLY SOILS CONTAINING BETWEEN 5 AND 20% FINER 'IHAN O.02mm. SANDY SOILS CON'FAh'qlNG BETWEEN 5 AND 15% FINER THAN 0.02mm. GRAVELLY SOILS CONTAINING MOFIE TITAN ,°_0% EINER 'rl-',Ahl O.02mm. Al'ID S/~,I.~[)Y SOILS (EXCEPT _FI_.N~E_ SII__TY, SANDS) COIqTAINII,iG f¢ORE TIIAN 15% FINER THAN 0.02 mm, CLAYS WITH PLASTICITY INDEXES OF MOkE THAN 12. EXCFPT VARVED CLAYS. ALL SILTS I~;CLUDI,.~Gf' '~ SANDY SILTS. I',,~E SILTY SANDS CON]AINING MORE 'IHAN 15c/o FINER THAN O.02mm. LEAN CLAYS WITH PLASTICITY Ik~DEXES OF LESS THAN 12, VARVED Ct. AYS. <~ < < 0 0 DICKINSON -OSWALD & PART ENGINEER,S AND ,SURVEYORS PHONE 907 277-1685 800 CORDOVA STREET ANCHORAGE, ALASKA 99501 ( / Septembe~p~/ Hr. Roll Strickland Greater Area Anchorage Borough Department of Enviornmental Quality 3500 Tudor Road Anchorage, Alaska 99507 Re: Highland Hills Subdivision Dear Mr. Strickland: In response to your earlier request, I have made an on-site visit of the above referenced subdivision and compared existing soil conditions to supplement the information previously submitted with the preliminary subdivision plat which indicated a consisent strata of non-frost susceptible material which is classified within the range of "well graded gravel sand" to "silty sands". However, the majority of the tests seem to indicate poorly graded sands, which classifies 150 in your scale with letter characteristics of SP. Those samples had been excavated by hand and were made at random depths which were limited to the length of the shovel handle. My own observations of the existing conditions of the subject property were based primarily upon the conditions of the cut bank along tke road which traverses the property in a north-south direction and serves as access for property owners to the south of the subject property. This road is a well graded and locally maintained road approximating 24 foot on the roadbed with a ditch section on the westerly side (towards the hill) and sloped to natural grade on the east. Within Highland Hill Subdivision, Unit No. 1, the road has consistent exposed material along the west side. This varies from approximately 18 feet at the northerly end of Lot 12 to approximately 2 feet of silty sand (SM Classification), which overlays poorly graded sands with gravel (SP, 150 sq. ft. per bedroom classi- fication). It is difficult to point out any particular lot locations as typical since the material seems to be consistently the same within this portion of the subdivision. LEWIS E. OICKINSON, P,E. MAURICE P. OSWALD, L.S. KENNETH B. WALCH, P.I~. - 2 - September 10, 1972 To summarize this review, I believe that there will be no apparent problem with on-site sewer and water systems for the individual property owners. The property is covered with a lush Birch and Spruce growh and tall native grass which further seem to indicate an existance of excellent soil conditions. No water seepage was noted through the subject subdivi- sion to indicate a problem area for later disposal fields. Numerous color p]~otographs were taken but unfortunately will not be developed for your meeting on Wednesday nigt~t. It is the opinion of this surveyor that the materials evident and described herein, indicate a proper and valid example of existing conditions and that this subdivision should be approved and allowed for filing without further consideration. Should you have any additional questions, please do not hesitate to call either myself or Mr. Dickinson. Yours very truly, MPO/jd "One test is t~orth a thoztsaml opiniov, s" o.:pt~mo..r 19~ 1972 D~ckinson & Oswald Pa~-tu~rs ~00 Cot'dov~ Stree't Anchora~;;e ~ ~aska S '~ Hilaad ]-~lls Subdivision Ea~le River~ Alaskm ubo,;ct: - Attn: '" ~,p. Dickinson Dear Sir: At the request of Mr. Joeseph Janke, our Company performed a soils investigation on the property located iu Block 1 of the proposed subdivision, 'l/ae purpose of this investigation was te determine the suitability of 'the proper't~y for supporting individual hor,:e sewsge systems. In order 'to determi, ne this, a series of tost pits were exes:vat- ed with a backhoe o~ong Hi!and Drive on lots 2, 6 & 9 of Block 1. Each test pit was excavated to at least 12 feet be].ow the road surface or 1.5 to 17 feet below the top of th~: ro:;~t cut, Based on these test pits~ it was determined that no bedrock occtu~s nest the ground surface. ~.e enclosed report shows the soil profile and the required absorption area per bedroom as det~,;~nined by the soil t,Tpe found. The results of these tests show that indiv.i.dual hor~e sewage system~ can b~, satisfactorily built on this p~operty. If you 'have an;; quest:Lons~ 'please contact our offence. Very truly yours~ "One test is worth a thousand opinions" Performed For ~_. Joe~lanke Oate Performed Leoal f)escription: Lot 2 Block This Form Renorts Soils I_oQ 9J_8-'F2 1 Subdivision HI1LAND HILI~ - FAGLE R~ Percolation Test nepth t 2 ]0 14 Soil Characteristics Road Cut · ~._ t,',, ["~:idv·. ~r ;,vc] ((I!,5 , ~ Was Ground Water Encountered? ..... ~]]__ d~? IF Yes, At what Depth? Read i nq Date Percolation Rate Gross Time Net Time Hi nute Seepane Pit Proposed Installation: Depth of Inlet cnMMENTS: YES Dentil to H20 Net Drop Drain Field Depth To Botfom Of Pit Or Treh~h__?~5_, £~. No bedrock or water table found to minus Test Performed By James D, Mack Data Certified By: OONST~LK~)N ~,~1'i~!~ ' One test is worth a tho~sand ot)m~ot s Performed For 14v~J~e-~m)J~ Date Performed_____~_~_~8~_ Legal Oescrivtion: Lot v Block 1 Subdivision]T~~~~~- This ~orm Reoorts Soils Loq ~S Percolation Test neoth Feet Soil Characteristics 10 12 16 Ro~d Cut Silty Sandy Gr~¥el (GM-225) Slightly Silty Zand Gravel, some layers of sandy gravel · Lsd'ge cobb~es tt~uout the grave]. ( GW~OM ) ( grad:~.t ~.cm cf' soil enclosed) Was Ground Water Encountered? .... IF Yes, At what Denth? Readinq F Date Percolation Rate Proposed Inst~T~ Depth of Inlet Gross Time Hinute ation: Seevaoe CnMMENTS: Net Time Denth to H20 Pit Depth To Bottom Of Pit 16o ~.guame £eet of Abso~2tion area req~_i_red per ~bedroom No bedrock or water table found to minu§ ~7~ feet. Net Dros yes Drain Field Or Trench 17 fto Data Certified By: CONSTI~L~_~~i~~: Test Performed By James D. Ma~ S~mol¢ D~f~ "One test is *vorth a thousand Combined smnple from ~st tble ,CII Hi ].amd Subdivision Opera}or 3}4---- Pro j ~_c t__~l_and Subdivision Eagle Bive~r~ Pi ~ Test Hole ~ 2 CO^R S E INTERMEDIATE FINE 0 ~. "One test is worth a thousand opinions" Performed For ML', Jc~e Jm~'~e r)ate Performed .... [.eaal Qescrintion: Lot 9 Block ]. Subdivision }~ZLAND IIZL~S EAGLE ..... Percolation Test This form ReQorts Soils / oq yes nenth Feet Was .O-re)Lind Watpr' Enc:,~,intered? Ic Yes, At whdt Det~l-h? . Readinq note Gross lime j Not lime genth to H,~Oc Her Dro Percolation Rate Hinute Pronosed Installation: See~aoe Pit yes Drain Field De~th of Inlet De~th To Bottom Of Pit Or Trench~ COMMENTS: 85 squ.~e feet absorption area ~q,uire~per bedroom No bedrock or water tabZe found to minus ]6 feet, Test Performed By Jmnea D. Mack Data Certified By:~CONSTIRUC~IO.B__~$~._k~,~