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HomeMy WebLinkAboutBUBBLING BROOK Lots 1-8 S-4638 DEPARTMENT OF HEALTH AND ENVIRONMENTAL PROTECTION PLATTING OR PLANNING AND ZONING CASE REVIEW CASE NUMBER $-4638 PETITION FOR DATE RECEIVED REZONING SPECIAL EXCEPTION VACATION RE'GUBDIVISION OF Unwin-Scheben-Kor~ta for Preliminary Plat ~ing ~on~ a subdivision of the SW ~/4, NW 1/4, Sec 23~T~Tocated within NW 1/4, Sec 23, T12N,R3W, S.M., Ak, containing 10.004 acres COMMENT TO PLANNING BY Dec 22, 1977 FOR MEETING OF January 4, 1978 COMMENTS: ENVIRONMENTAL SANITATION: Cases PUBLIC WATER NOT AVAILABLE PUBLIC SEWER NOT AVAILABLE TO SERVICE PETITION AREA. DEC 2 01977 ENVIRONMENTAL ENGINEERING: 71-014 (9/76) I .i ' I 7 LEGEND // ~ .' q%O ' , R6 D e~cript i on _ / / \ / / / / / V I I I '-'--- 73Z' SURVEYOR'S CERTIFICATE plat of , professional 't 25 30 ' 3 55 I VICINITY MAP Ti2N,RS W SC::.L[ I"=-I MILE ':'-~RELIMINARY PLAT O~ BUBBLING BROOK -SUBDIVISION A SUBDIVISION OF THE SWI/4, SEI/4, NW I/4,-SE .C. 23 - LOCATED WITHIN I~IWI/4 SEC. 23. T12N. R3W SM. .. CONYAINING 10.O04 ACRES .:.,~~ UNWIN-SCHEBEN-KORYNTA ' ' ~ Consuiling Engineers and Surveyors. 103 E 26th Ave., Anchorage · , ~. · ' 272-'8911 or 272-6051 CHECKED l.S .... DATE 10:25:77 GRID 2638 F.B.~q' J SHEI~ '~ OF · CONSULTATION · TESTING · EXPLORATION · CHEMICAL · - MATERI/iLS · INSPECTION SOIL CLASSIFICATION CHART 50% GRAVEL x CLAYEY ~0/ CLAYEY \ / OR SI LTY SI LTY \\ SAND \ \ DY \GRAVE L GRAVELLY \ SAND \ 0 I0 20 30 40 50 60 70 GRAVEL (+~IOSCREEN) % BY WEIGHT. RAVEL 80 90 I00 NONFROST SUSCEPTIBLE SOILS ARE INORGANIC SOILS CONTAINING LESS THAN 5O/o 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 :~ AND 15% FINER THAN 0.02 mm. F:5 Q. ~ GRAVELLY SOILS CONTAINING MORE THAN 20% FINER THAN O.02mm. AND SANDY SOILS (EXCEPT FINE SILTY, SANDS) CONTAINING MORE THAN 15% FINER THAN O.OEmm. b. CLAYS WITH PLASTICITY INDEXES OF MORE THAN 12. EXCEPT VARVED CLAYS. F4 e. ALL SILTS INCLUDING SANDY SILTS. b. FINI~ SILTY SANDS CONTAINING MORE THAN 15% FINER THAN 0.02 mm. c. LEAN CLAYS WITH PLASTICITY INDEXES OF LESS THAN d. VARVED CLAYS. 0 1 2 3 4~ _ SOILS LO(__ PROdECTB~bbl'~n.cl Brook Subd. . TEST HOLE NO. CLIENT Buster Newton W.O. 77886 .... SHEET 9 OF~ ELEV. TOP OF HOLE DATE '11/15/77 9 724 Peat, PT Damp, brown, sandy silt, ML Damp, brown, slightly silty Sand, SP - ~--~-- (traces of small gravel) Water table Saturated, brown, slightly silty sand, SP {traces of small gravel) Bottom of Hole NOTE: 1. Water table at ll.5' at time of drilling. 2. Field perculation test results - 5.3 min/inch. SHEET 8 OF g SOILS .LOG_ PROJECT Bubbling Brook Subd. CLIENT 'Buster Newton TEST HOLE NO. 8 ELE¥. TOP OF HOLE 692 W.O. 77866 ' DATE l 1/15/77 Peat, PT Damp, brown, graVelly silty sand, SM Damp, br'own, silty gravelly sand., SW/SM (Some cobbles and boulders) Damp, brown, silty gravelly sand, SW/SM · NOTE: '. 1. No ground water table at time of drilling. 2. Field perculation test results - 5 min/inch. SHEET 7 ,OF 9 SOILS PROJECT Bubblinq Brook Subd. CLIENT Buster Newton W.O. 77886 ,LO L., TEST HOLE NO. 7 ELEV. TOP OF HOLE 700 DATE '11/15/77 Peat, PT Damp, brown, gravelly sandy silt, ML Damp, brown sandy silt, ML Grey lenses, traces of gravel Damp, brown, sandy silt, ML (some small gravel) Bottom ot Hole NOTE: 1. No ground water table at time of drilling. 2. Field perculation test resblts - 60 min/inch. SOILS PROJECT BubblSn~ Brook Subd. CLIENT Buster Newton W.O. 77886 SHEET TEST HOLE NO. 6 · ELEV. TOP OF HOLE '1712 DATE 1 ]/] 5/77 _ OF . Ipea't, PT' Organic, sandy silt, OL Damp, brown, gravelly sandy silt,.ML Damp, brownish grey sandy silt,. ML (traces of small gravel) 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 - 45 min/inch. SHEET § OF 9 SOILS PROJECT ·BUbbling Brook Subd. CLIENT Buster Newton TEST HOLE NO. 5 ELEV. TOP OF HOLE 718 W.O. 77886 DATE 11/15/77 Peat, PT Damp, brown, sandy silt, ML (traces of small gravel) Damp, brownish grey sandy silt, ML (traces of small gravel) Damp, brownish grey sandy silt, ML (redish lenses) ril ' Bottom of Hole NOTE: -- 1. No ground water table at time of . le- percu a ion test results - 35 mln/inch.'~ SHEET 4 OF g SOILS LO(_ PROJEOTBubb~ing Brook Subd. CLIENT Buster Newton W.O.. 77886 TEST HOLE NO 4 ELEV. TOP OF HOLE 780 DATE '11/15/77 Perche~ Saturated, grey, gravelly sandy silt, ML Wet, grey, gravelly silty sand, SM ! Damp, grey, gravelly silty sand, SM Bottom of Hole NOTE: 1. Water table at 1.5' at time of drilling. 2. No perculation test. SHEET 3 ,OF 9 SO'ILS PROJECT Bubbling Brook Subd. CLIENT Buster Newton W.O. 77886 TEST HOLE NO. 3 ELEV. TOP OF HOLE 719 DATE 'i 1/15/77 Peat, PT Organic, sandy silt, OL Damp, brown sandy silt, ML Damp, brown, sandy silt, SM - Damp, brown, gravelly sandy silt, SM Damp, brown, sandy gravelly silt, SM BOttom Ot hole NOTE: 1. No ground,.water table at time of drillinq.  Z'~Field perculation test results - 30 min/inch. -- SHEET 2 .OF 9 SOILS mo ,, PROJECT Bubbling Brook Subd. CLIENT Buster Newton W.O. 77886 TEST HOLE NO. 2 ELEV. TOP OF HOLE 708 DATE 11 J15/77 Peat, PT Organic, sandy silt, 0L Damp, brown, sandy silt, ML Damp, brown, gravelly sandy silt, SM Damp, brown, sandy silt, SS (traces of §raYel) Water table Bottom of Hole NOTE: 1. Water table at 14~ feet 2..Field perculation test - 13 min/inch SHEET 1 ,OF 9 ,-; _ SOILS LO , PROJECT Bubbling Brook Subd. CLIENT Buster Newton W.O. 77886 TEST HOLE NO. ELEV. TOP OF HOLE DATE '11/15/77 704 Peat, PT. Organic sandy silt, OL Damp, brown, sandy silt, ML . .i'~. Damp, brown, gravely sandy silt, SM Damp, brown, sandy silt SM . .. (traces of small gravel) Bottom of Hole NOTE: 1. No ornund water table at t~m: nf dril <~'-. Fie~d perculation test - 30 mi~ Mr. Buster Newton December 5, 1977 Page Two SITE AND SOIL CONDITIONS The site is a 660 foot square parcel having access from Rockridge Drive on the east and Ravenwood Subdivision on the south. The site is dissected in a southeasterly/northwesterly direction by a fork of the Little Campbell Creek. The parcel slopes uniformly from southeast to northwest at an approximate 6% to 8% average slope. A small knoll is located in the southeasterly corner. There are no areas with slopes in excess of 25%. The parcel may be divided into two very distinct soil map units for purposes of identifying perculation characteristics. A 300 to 400 foot wide band centered on the creek channel is characteristic of old alluvial deposits and consists primari__ly nf ~el~ gr~dp~ sands and qravels with good perculation characteristics.-T__eest holes~ _g-are typiCal of this ueDos~t. Beyond this band, the mater~a~i-~'K~'~e~much siltier and tighter as d~monstrated by test holes l, 3, 5, 6 and 7. CONCLUSIONS The minimum perculation rates observed in the field for the following holes are: Test Hole Number 1 - 30 minutes Test Hole Number 2 - 13 minutes Test Hole Number 3 30 minutes Test Hole Number 5 35 minutes Test Hole Number 6 45 minutes est Hole Number 7 60 minutes est Hole Number 8 5 minutes est Hole Number 9 5 minutes )er inch )er inch )er inch )er inch )er inch )er inch )er inch )er inch On-site waste disposal systems appear feasible on all lots. An aerated package plant or other treatment process is advisable for the lots with high percula- tion rates. We hope this is sufficient for your present needs. If we can offer further clarification, please do not hesitate to contact us. Very truly yours, Attachments EDK/clr Earl D. Korynta, P.E. UNWIN · SCHEBEN · ORY N TA CON~ULI'ING ENGINEERS AND SURVEYORS I 2515 A ST., December 5, 1977 ANCHORAGE 99503 (907) 276-4245 Mr. Buster Newton 411 East 36th Avenue Anchorage, Alaska 99503 Re: Proposed Bubbling Brook Subdivision Subsurface Soils Investigation Dear Mr. Newton: This report presents the results of our soils investigation for the proposed subdivision of a 10 acre tract located east of Birch Road and just west of Ravenwood Subdivision. The investigation was conducted on November 15 and 16, 1977. The results of this investigation are included in this report as follows: Vicinity Map Test Hole Location Sketch Test Hole Logs (Sheets I through 9) 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. Test holes were lo§§ed and perculation tests conducted by our firm. The purpose of the investi§ation was to provide soils data and perculation tests for establishing the feasibility of on-site disposal of sanitary wastes using seepage pits. To accomplish this, we drilled 9 borings distributed across the site with 1 test hole on each lot at the probable septic system location. The test hole locations are shown on the attached location sketch. All borings were drilled to a depth of 16 feet. During the drilling, our engineer was present to log the materials encountered and obtain grab samples of the soil types. All soils were visually classified in the field in accord- ance with the unified soil classification system as described in the standard explanatory information attached herewith. Since the site is fairly small and readily accessible from both sides, per- culation tests were conducted in all holes at the completion of the drilling qjand logging. The perculation tests were conducted from the 6 to 12 foot levels in each of the holes in accordance with the Manual For Septic Tank Practice published by the PHS. A ground water table was encountered in test hole Number 9 at the 12 foot level. Therefore, the perculation test in this hole was conducted between the 4 to 8 foot level. GORDON D. UNWlN~ P.E. LEO $CHEBEN~JR.~P.E.~L.S. EARL D. KORYNTA~ EE. 0 z ~ x j) · , oF Bearing 5 00" 02' 04" w (9 :C -~ -' = =- N O0° 00' 33" E ? -:~ ..... ,.29 658.89 prop ...... 658,89 N 00°00'33 "~ Z MAEL ST 78-1 I0 FO