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Home My WebLink AboutHIDEAWAY LAKE S-4639 DEPARTMENT OF HEALTH AND ENVIRONMENTAL PROTECTION PLATTING OR PLANNING AND ZONING CASE REVIEW CASE NUMB,ER S-.4639 PETITION FOR R, EZONING SPECIAL EXCEPT ON VA'~ATION R E,6[J:B DI VISION DATE RECEIVED COMMENT TOPLANN~NGB¥. Dec 22, ]977 /d~'Unwin-Scheben-~orynta for Preliminary P1 f Hideaway Lake Subdi v-i-sq on FOR MEETING OF January 4, 1978 COMMENTS: CaSeS ENVIRONMENTAL SANITATION: PUBLIC WATEB NOT AVAILABLE PUBLIC SEWER NOT AVAILABLE TO SERVICE PETITION AREA ENVIRONMENTAL ENGINEERING: 71-014 (9/76) UNWl, SCHEBEN ORYNTA CONSULTING ENGINEERS AND SURVEYORS 2515 A ST., 'ANCHORAGE 99503 (907) 276-4245 December 5, 1977 Mr. Bob Sparks 835 "D" Street, Suite 401 Anchorage, Alaska 99501 Re: Proposed Hideaway Lake Subdivision Sursurface Soil Investigation Dear Mr. Sparks: This report presents the results of our soils investigation for the proposed subdivision of an approximate 25 acre tract located East of Hideaway Lake and south of Upper O'Malley Road. The investigation was conducted on November 28 to December l, 1977. The results of that investigation are included in this report as follows: Vicinity Map Test Hole Location Sketch Test Hole Logs (Sheets 1 through 15) Summary of Laboratory Test Data Standard Explanatory Information Drilling was accomplished utilizing a mobile drill B-50 mounted on a flex track Nodwel vehicle, owned and operated by Denali Drilling, Inc. The test holes were logged and penculation tests conducted by our firm. Harding-Lawson & Associates performed the laboratory test data on grab samples taken during the drilling operation. The purpose of the investigation was to provide sufficient soils data for establishing the feasibility of on-site disposal of sanitary waste using seepage pits. To accomplish this, we drilled 15 borings distributed across the site as shown on the test hole location sketch. The borings were located one on each lot at the most probable location of a future septic system. During the drilling, our engineer was present to log the materials encountered and to obtain grab samples of the soil types. All soils were visually classi- fied in the field in accordance with the unified soil classification system as described herein. The grab samples were brought back to the laboratory for further analysis and verification of the field logs. In addition to the soil sampling, several perculation tests were conducted. Based on visual classification of the soil types during the 'logging of the test holes, the areas with probable higher perculation rates were identified. One or more perculation tests were then conducted in each of these areas. GORDON D. UNWIN,PE. LEO SCHEBEN,JR.,P.E.,L.S. EARL D. KORYNTA, RE. M'.'"!iCF/!q',' OF ANCHORAGE F;'~' .... O~ ~; ,'L]H & EN", ,. C);,:,..Li'~'iAL HtE;iECTIOhl i]EC 8 t977 RECEIVED Mr. Bob Sparks December 5, 1977 Page Two SITE AND SOIL CONDITIONS The site is a 990 foot square parcel with an additional 330 foot square parcel in the southeast corner. Hideaway Lake occupies approximately 5.6 acres of the northwesterly portion of the site as determined by the lake line meanders. Drainage enters the lake along the southerly shore line through the proposed Lot 2, Block 1. Site topography is very irregular, especially in the northerly half. However, general drainage is toward the lake at an average 12% to 15% slope. There are no areas within the parcel which slopes in excess of 25%. The site is primarily underlaying by sands and gravels to the depths explored (16'). The granular material is well bedded and well graded, with fines ranging from little or none up to approximately 1~%. The surface of the site is blanketed by an organic mat of forest duff or peat ranging in depth from 6 inches to 24 inches. Underlying the organic mat is a layer of fine organic sandy silt or silty sand (top soil) ranging in depth of up to 3 feet. A very dense sandy gravelly silt layer located approximately 12 feet to 14 feet below the surface underlies the southeasterly corner of the site. Apparently this dense stata prevents further penetration of the surface infiltration. There- fore, free water was encountered at the time of drilling in test holes 10 through 15 at the interface between the relatively loose surface materials and this dense strata. Based on the observed field perculation rates, visual test hole logs and laboratory test data, on-site sanitary waste disposal systems appear feasible: Minimum perculation rates for the proposed lots are estimated as follows: Block 1, Lot 1 - 2 min/inch Block 2, Lot 1 - 9.2 min/inch (measured) Lot 2 - 2 min/inch (measured) Lot 2 - 8 min/inch Lot 3 - 6 min/inch Lot 3 - 15 min/inch Lot 4 - 2 min/inch Lot 4 - 15 min/inch (measured) Lot 5 - 6 min/inch Lot 5 - 15 min/inch Lot 6 - 6.3 min/inch (measured) Lot 6 - 15 min/inch A~ Lot 7 - 2 min/inch Lot 7 - 15 min/inch l~ We hope this i clarifications, please do not hesitate to contact me. Attachments EDK/clr s sufficient for your present needs. If we can offer furtH~i~' Very truly yours, Earl D. Korynta, P.E. 1,/'.' !;?: "r-, r,c ANCHORAGE i r~' 8 i977 SOl LS LO~ ~, PROJECT_'Hidden Lake Sub~, CLIENT Bob Sparks W.O. 77897 TEST HOLE NO. i[LEV. TOP OF: HOLE DATE '11/28/77 Peat, PT Organic sandy silt, OL Damp, brownish red sandy silty gravel, GM Damp, brown, gravely sand, SW - - Grab sample Damp, brown, sandy gravel, GW Bottom of Hole NOTE: 1. No water table, at time of drilling. 2. Estimated perculation rate - 2 min/inch. r"~,', 8 /977 SOILS LO( PROJECT Hidden Lake Subd'. TEST HOLE NO. CLIEN'F Bob Sparks ' ELEV. TOPOFHOLE W.O. 77897 DATE 11/28/77 Peat~ PT Organic sandy silt, OL Damp, brownish red silty gravel, GM Damp, brownish grey gravely silty sand, SM Damp, brownish grey silty sand, SM Grab sample --._i- Damp, brownish grey sandy silt, ML (traces of gravel) ~Bottom of Hole ._~ NOTE: 1. No ground water table at time of drilling. ..~ 2. Field perculation test results 6.3 min/inch. RE C l.!lV E f) SOILS LOx` PROJECT 'Hidden Lake Suba. CLIENT Bob Sparks W.O. 77897 TEST HOLE NO. 3 ELEV. TOP OF HOLE DATE ' ll,/28/77 Peat, PT Organic sandy silt, OL Damp, brown, sandy silt, ML Damp, brown, gravely silty sand, SM · X Grab sample !' Damp, brown silty sand, SM Bottom of Hole NOTE: 1..No ground water table at time of drilling. 2. Estimated perculation rate - 6 min/inch .... ,,, 8 1gz? R F r'~ IV !'~ D SOIL'S PROJECT'Hid~ten Lake Sub~. CLIENT Bob Sparks - W.O. 77897 LO TEST HOLE NO.. 4 ELEV. TOP OF: HOLE DATE · 11/29/77 0r-icc i '~ Peat, PT Damp, brown, sandy gravel, GW- Damp, brown, gravely sand, SW Grab sample Damp, brown, gravely sand, SW Bottom of Hole NOTE: 1. No ground water table at time of drilling. 2. Estimated perculation rate - 2 min/inch. I'/,'~, , GF ANCHORA~ !: ~,, 8 i977 SOILS PROJECT HiddEn l akP Suhd. CLIENT~ob Sparks W.O. 77897 LO( TEST HOLE NO..__ ELEV. TOP OF ttOLE DATE '12/1/77 Peat, PT __ Organic, sandy silt, OL __ Damp, brown sandy gravel, GW m Grab sample __ Damp, brown, gravely silty sand, SM _. Bottom of Hole -- NOTE: -- 1. No ground water table at time of drilling. -- 2. Estimated perculation rate - 6 min/inch. -- !977 5~ 0 1 L$ L 0 ~ PROJECT'Hid~en Lake Subd. CLIENT_~ob Sparks W.O. 77897 TEST HOLE NO. ELEV. TOP OF HOLE DATE '12/1/77 Peat, PT Damp, brown, sandy gravel, GW Grab sample Damp, brown, silty sandy gravel, GM Bottom of Hole NOTE: 1. No ground water table at time of drilling. 2. Estimated perculation rate - 2 min/inch. SOl Ls LC· ~ PROJECT Hi~den Lake Subd'. CLIENT Bob Sparks W.O. 77897 TEST HOLE NO. 7 ELEV. TOP OF HOLE DATE' 11/30/77 Peat, PT Organic, sandy silt, OL Damp, brown, sandy gray61, GW (some cobbles and boulders) Damp, brown, sandy gravel, GW Grab sample Bottom of Hole NOTE: 1. No ground water table at time of drilling. 2. Estimated perculation rate 2 min/inch. ,. ' r OF Hi'~i!H & SOILS r PROJECT_FJidden Lake Subd. CLIENT Bob Sparks ' W.O. 77897 TEST HOLE NO. ELEV. TOP OF HOLE DATE 11/30/77 Peat~ PT Damp, brown, silty sandy gravel, GM Damp, brown, sand Damp, brown, silty, gravely sand, SM _~_ Grab sample -- Damp, brown, gravely silty sand, SM Bottom of Hole NOTE: -- 1. No ground water table at time of drilling. 2. Field perculation test results - 9.2 min/inch. so,iS PROJECT H'idd~n Lake Subd. CLIENT Bob Sparks - W.O. 77~7 LO( TEST HOLE NO. 9 ELEV. TOP OF HOLE DATE 11/30/77 Peat, PT -- Organic, sandy silt, OL Damp, brown, sandy gravel, GW __ Damp, brown, gravely sand, SW __ ~ Grab sample --~- Damp, brown, silty sand, SM m -Bottom of Hole NOTE: -- 1. No ground water table at time of drilling. N 2. Estimated perculation rate - 8 min/inch. -- soILs LO PROJECT' Hi~lden Lake Subj. CLIENT Bob Sparks W.O. 77897 TEST HOLE NO. l0 ELEV. TOP OF HOLE DATE · 11/30/77 Peat, PT Damp, brown, sandy silty gravel, GM Damp, brown, sandy silt, ML Damp, brown, sandy silt, ML (traces of gravel) Grab sample Water table Wet, brown, silty sand, SM (traces of gravel) · Bottom of Hole NOTE: ~. Ground water table at 14.0' 2. Estimated perculation rate - 15 min/inch. I~N ,'i; J?;. ] N i,?.L PilL): ~.:C1 ION /977 SOILS PROJECT 'Hidden Lake Subd. CLIENT Bob Sparks W.O. 77897 LO , TEST HOLE NO ELEV. TOP OF HOLE DATE 11/29/77 11 Peat, PT Organic, sandy silt, OL Damp, brownish grey silt, ML Damp, brown, silty sand, SM __ Grab sample ~ Water table Wet, sandy silt, ML Bottom o'f Hole NOTE: 1. Ground water table at 13.0'. --- 2. Estimated perculation rate ~ 15 min/inch. .i :',. mi.,L !:~(;i'~CiiON SOILS PROJECT Hidden Lake Subd. TEST HOLE NO. 1 CLIENT Bob Sparks ELEV. TOP OF HOLE DATE ' 11/30/77 W.O.. 77897 Peats PT Organic, sandS silt, OL Damp, brown, sandy silty gravel, GM Da'mp, brown, silty sandy gravel, GM Grab sample Damp, brown, silty gravely sand, SM Water table 'Bottom of' Hole NOTE: --- 1. Ground water table at 14.0'. 2. Field perculation test results - 15.0 min/inch. 1977 SOILS PROJECT Hidden lake Suhd. CLIENT Bob Sparks W.O. 77897 LOG TEST HOLE NO. 13 ELEV. TOP OF HOLE DATE_ 11/29/77 SHEET 1 3 OF 15 PT anlc, sandy Slit, UL Surface seepage into hole Damp, brown, sandy silt, ML Wet, brown, gravely sand, SW Grab sample Water table Very wet, brownish grey, silt, NOTE: 1. Ground water table at 12.0' 2. Estimated perculation rate - 15 min/inch. 10o77 SOILS LO PROJECT 'Hidden Lake Subd, . TEST HOLE NO. 14 CLIENT Bob Sparks ELEV. TOP OF HOLE ° ° ~ ° W.O._ 77897 DATE '1]/29/77 Peat, PT Organic, sandy silt, OL Damp, brown, sandy silt, ML Damp, brownish grey, silty gravely sand, Grab sample Water table Very wet, brown, sandy silt,_ML Bottom of Hole NOTE: 1. Ground water table at 12.0'. 2. Estimated perculation rate - 15 min/inch.. SOILS PROJECT Hidden l ak~ SHhd_ CLIENT Bob Sparks W.O. 77897 LO ,; TEST HOLE NO. 1 ELEV. TOP OF HOLE DATE ' 12/1/77 O~qCCl ,v L.)F ,v Peat, PT Wet, organic, sandy silt, ML Surface seepage into hole . Damp, silty gravely sand, SM . -- Grab sample ! Water table -- Very wet, brown, sandy silts, ML Bottom of Hole NOTE: .__ 1. Ground water table at 12.0'. -- 2. No perculation test. __ '-,: ~, d · CONSULTATION · TEST'I'~G ' I·' EXPLORATION · CHEMICAL · MATERIAI. S · INSPECTION SOIL CLASSIFICATION CHART 3,00/o GRAVEL J ~ CLAYEY CLAYEY / OR ~>/ SILTY SI LTY \ \ SAND \ \ \GRAVE L \ GRAVELLY \ SAND GRAVEL 0 I0 20 30 40 50 60 70 80 90 I00 ,GRAVEL (+¢IOSCREEN) % BY WEIGHT NONFROST SUSCEPTIBLE SOILS ARE INORGANIC SOILS CONTAINING LESS THAN 3% FINER THAN O.02mm. GROUPS OF FROST-SUSCEPTIBLE SOILS; FI F2 F3, o., F4 o, b. C, d. GRAVELLY SOILS CONTAINING BETWEEN 3, AND 20% FINER THAN O.02mm. SANDY SOILS CONTAINING BETWEEN 3, AND 15% FINER THAN 0.02 mm. GRAVELLY SOILS CONTAINING MORE THAN 20°/0 FINER THAN O.02mm. AND SANDY SOILS (EXCEPT FINI~ SILTY~ SANDS} CONTAINING MORE THAN 15°/o FINER THAN O.02mm. CLAYS WITH PLASTICITY INDEXES OF MORE THAN 12. EXCEPT VARVED CLAYS. ALL SILTS INCLUDING SANDY SILTS. FINE SILTY SANDS CONTAINING MORE THAN 15% FINER THAN O.Q2mm. LEAN CLAYS WITH PLASTICITY INDEXES OF LESS THAN 12. VARVED CLAYS. MILITARY R~ ~ r RVATION 21 22 ~: 23 24 HUF~N ROAD ~ 28 2~ 2~ ~ 25 30 33 3 4 35 V-IOlNITY '~AP T12N~R3W SOALE I"~1 MiLE PRELIMINARY HIDEAWAY LAF --' · . LCCATED W · ' . NWl Zl Se~,c, licr 2 " . . CDNT~,NIN] 2 O(] / ~~ II'~' ~IN' .¢',CH[:B ._..~ C ,n:ul lng Engi eers.and Su v~ J_DRAWN T~ .-''SCALE I": IOO' '' J · JC~ECKEO L$' ' '' i D~T[ '11-i-77' I '. LAKE 'SUBDIVISION WITHIN - NW I/4 SeclJon 24 TI2N~R3W S:M. CONTAINING 25.00 ACRES BEN"KO '~__~ UNWlN'SCHE R NTA - Consulting Engineers.ancJ Surveyors.- 103 E zb~'Ave Anchorage .272:'89'~1 or 272-60S1 ... ~O. No. 77897 JnLE No, 5-46 GRID2640JF~.'' ~IEET ! OF" I977 HARDING - LAWSON ASSOCIATES Engineer& Geologists and Geophysicists 624 W. International Airpod Road, Anchorage, Alaska 99502 · (907) 276-8102 JAY M. ENGLAND Professional Engineer Associale-in-Oharge DUANE L. MILLER Professional Engineer Chief Engineer LETTER OF TRANSMITTAL TO: ATTENTION: UNWIN, SCHEBEN, KORYNTA 2515 "A" Street Anchorage, Alaska 99503 Mr. Earl Korynta, P.E. Homer and Hidden Lake Subdivisions 5552,005.08 SUBJECT: OUR JOB NO. Transmitted herewith is/are the following: Two copies of the results.of the particle size analysis and percent passing No. 200 sieve size on the samples you submitted from Homer and Hidden Lake Subdivisions. CC: BHy~AWSON A~S OCIAT~ES Date Duane L. Miller December 5, 1977 _~,. i, 8 ig?? U S Slondord Sieve Openm9 Size I U.S.Slondord Sieve Numbers I Hydromate¢ " '"' '111 GRAIN SIZE IN MILLIMETERS COBBLES. COARSE I FINE COARS~ MEDIUM J FINE Symbol Somple Source Clossificotion ~ Test Hole 1 G~Y~SH-GREEN SANDY GRAVEL (GN-GM) ~ Test Hole 3 G~YISH-GREEN G~VELLY SIL'~SAND (SM) HARDING- LAWSON ASSOCIATES PARTICLE SIZE ANALYSIS PLATE Con~J~in~ E~neers ~d Geologists HIDDEN LAKE SUBDIVISION ~ Alaska Job No.]~.005.08 Appr:.~ate 12/77 .,., U S StondordSieve Opening Size I U.S.Sfandard Sieve Numbers J Hydromeler 4 ~ 2 4 8 I0 16 2050 405060 I00 200 ~.70 III / .~ II11111 II III ~ I0 5 I 0.5 OI 005 001 0.005 0~1 GRAIN SIZE IN MILLIMETERS COBBLES COARSE I F~NE COARS~ MEDIUM J FINE Symbol Somple Source Clossificelion ~ Test Hole 5 G~YISH-GREEN G[~VELLY SILTY SAND (SM) (sma]'] amount of.roots) ~ Test Ho]e 7 G~YISH-GREEN SANDY G~VEL'(GP-GM) HARDING- LAWSON ASSOCIATES PARTICLE SIZE ANALYSIS PLATE Cons~dtinp E~zp{ncers a~d GcoIopists HIDDEN LAKE SUBDIVISI0~ 3 Alaska ~bNo. 5552,005.08 _Appr~ate 12/77 U 5. Slondord Sieve Open,ng Size I U.S.Sfondl3rd Sieve Numbers I Hydrometer '~]llrl' 1' ' '~-~~~.~,' ' I' II HIIIII III ~1~'~ II GR~IN SIZE I~ ~ILLt~ETER5 SAND COBBLE5 J COARSE J FINE Symbol Somple Source Clossification ~ Tes~ Hole 30 L[GHT GREEN 5~DY SILT O Tes~ Ho3e ]] LZGHT GREEN SANDY SILT (HL) HARDING- LAWSON ASSOCIATES PARTICLE SIZE ANALYSIS PLATE Alaska Job No. 5552,005,08 _Appr~Dste~ ]2/77