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HomeMy WebLinkAboutHILLSIDE NORTH ADDN #9 S-10701Hill id No th #5- ! 070 ! DHI CONSULTING ENGINEERS Civil ° Surveying ° Planning May 3, 2001 W.0.:20459 Mr. Jim Cross Development Services Department 4700 South Bragaw Anchorage, Alaska 99508 RE: Preliminary Plat - Hillside North Subdivision Addition//9 (S-10701) Soils Investigation Report for On Site Septic Systems Dear Mr. Cross, The following report is being submitted for your review and approval in accordance with Title 15.65.180. Hillside North Subdivision Addition #9 is a continuation of the planned development which has been under construction over the past ten years. This subdivision, consists of a thirty acre tract being subdivided into eight lots. The lots range in size from 2.3 to 6.9 acres with the average lot size being over 3 acres. Lot 1 has an existing single family residence for which a new septic system was installed last summer (2000). The record drawings for this system are enclosed in Appendix A. For the remaining seven lots (2 through 8) test pits were dug to a depth of 16 feet using a tract mounted backhoe. Soils were visually classified and a four inch perforated monitoring tube was placed in each pit. The soils were found to be consistent with earlier plats. The soils consist primarily of slightly silty sands to slightly silty sandy gravels which are overlaid by a foot of organic material. There was no water encountered in any of the test pits at the time of the excavation; and there was no water observed in any of the test pits throughout the month of April. All the percolation rates were less than five minutes per inch. Except for Lot 8 which was 15 min/inch. Soil logs are included Appendix B. In accordance with Title 15.65.180.B.1 (Subdivision Standards), Table 2, lots 2-7 have a minimum of 10,000 square feet of Total Reserve Area and Lot 8 has 14,00 square feet. The enclosed map (Figure 1) identifies the location of each test hole and identifies the area on each lot which meets the above standards. There is adequate area on each of the eight lots for an on site septic system and a domestic well. Very truJy yours, ~/It~g Engineers Dee High, P.E. ~ Principal 459dhjcltr.wpd cc: Roger Cremo Dimond Center Tower, 5th Floor ° 800 E. Dirnond Blvd., Suite 3-545 * Anchorage, Alaska 99515 (907) 344-1385 · Fax 344-1383 DHI CONSULTING ENGINEERS Civil ° Surveying ° Planning January 19, 2001 W.O.: 20459 Mr. Jim Cross Department of Health & Human Services P.O. Box 196650 Anchorage, Alaska 99519-6650 RE: Hillside North Subdivision, Addition No. 9 Case No. S-10701 Well Report Dear Mr. Cross, Attached is a report on the existing wells that surround the proposed subdivision. As you can see from the well logs, well production is high, the wells are not into bedrock and water quality is to be good. The existing aquifers will easily support seven additional wells. As discussed at the pre-application meeting, we will do the soils work for the septic this spring. Let me know if you need anything else on the availability of water. cc: Roger Cremo 459dc010901 S Principal Dimond Center Tower, 5th Floor · 800 E. Dimond Blvd., Suite 3-545 · Anchorage, Alaska 99515 (907) 344-1385 ° Fax 344-1383 WELL REPORT HILLSIDE NORTH SUBDIVISION, ADDITION 9 Date: January 9, 2001 Case Number: S-10701 Hillside Subdivision, Addition No. 9 consists of 8 lots totaling approximately 30 acres. The lots range in size from 2.3 to 6.9 acres; averaging 3.75 acres per lot. With the exception of one parcel located near the southwest comer of the Subdivision, all the surrounding property has been developed. The lots in this area are zoned R-10 (Large Alpine Lots) and are generally larger than 1.5 acres. They are serviced by private wells and on site septic systems. One of the proposed lots (Lot 1) has a private well which has been in production since 1955. Figure 1 shows the lots for which we have been able to find well logs or to obtain information about the well. Appendix A contains copies of the well logs. The soil deposits are primarily the result of glacial activity which have been modified by small localized alluvial deposits. Soils range from very clean sandy gravels to silty sandy gravels. The glacial till overlays bedrock which is generally estimated to be about 350 feet below the surface, though bedrock has been encounter at depth as shallow as 200'. The wells in this area range in depth from 56 to 346 feet. The average depth of the individual wells is 162 feet With the exception of 3 wells, all the wells draw water from two water bearing zones. The first zone is between 50 and 90 feet. The second zone is between 175 and 200 feet. There are two well that draw water in the 120 foot range and one well is drawing water at about the 320 foot range.. Production rates range from as low as 4 gpm and as high as 50 gpm. The average flow rate is 22 gallons per minute. Wells in this area have very good production rates and the water encountered is ofgood quality. One oftheoldest wellsinthe area is located on proposed Lot # 1 and hasbeen in continuous production since 1955. It is 127 feet deep and products in excess of 10 gallons per minute. In 1999, water tests for this well reported the following: Chloride 1.0 mg/l Arsenic 0.01 mg/1 Magnesium 4.3 mg/l Calcium 26.5 mg/1 Iron 0.052 mg/1 Lead Not Detectable Sulfate 12.9 mg/l Nitrates 1.4 mg/l Fecal Coliform 0 Other Bacteria 0 None of the reported amounts exceed current drinking water standards. Opinion: We expect the new wells to encounter water between 60 and 200 feet. It appears the existing aquifers can sustain seven additional wells. Production rates should be 5 gallons per minute or mo~ we~ should have no impact on the existing wells in the area. Dee High, P.E. t~ ~/t Date 459wellrepor~ C PROPOSED ~NEt. L ~NF~H 100' w£M. RADIUS m I0,000 SO.FI'. SEPllC RESERVE AREA (LOT 8 14,000 SO.FT.) ', PROPOSED DRIVEWAY 050 LOTS 5 USABLE ABSORPTION AREA 1-8 HH.LSIDE NORTH SUBD. #9 F~4,SgCFRiD 1'-200' o~z 4/4/0'1 Thu May 17 08: 18:35 2001 W.O.f 20459 $.'$'$'~-~' DEl CONSULTING ENGINEERS ~4.~'~=~. OF,'~/.. ~,~ SO,~ L~-PGCO~O, ~ST ~ST HOLE ~2 ~Rrma~ Fro: ROGER CREMO DA~ P~Fm, ED: 3-29-01 ~L D~P~:LOT 2 HILLSIDE NOR~ ADD. ~9 ~ 24' ~OZEN ~GANIC ~LT W~T MAT 1 L~ ~O~N TO ~ ~ ~OPE ~ P~N 2 '~'o 3 .o .. 4 ; o.. 5 ' .o'' I 7 -:0 .. , 8 ~ · SANDY GRA~ W/ ' ~ACE ~LT. RO~ 9 o ' TO ~2' ~N ~ZE. .'~ .0 MA~RIAL IS ~NSER PAST 10' WAS GR~ND WA~R S 10 ·" EN~N~R~ I NO L o 0 11 ~ ~" IF ~S, AT ~AT p ~ DEP~ ? E 12 "o DEP~ OF WA~R ". 0 A~ MONITORING ~ N~E DA~: O' ~ I ~ ~4~ 14 t ~ ~ 15 - '.,o.' ~ I 0 I 16 ~o' I 17 '. "' i I · I 0 18 B.T,H. 19 ~ PERi,ON RA~: 0.65 (MINU~S~N~.) PER~ DIAM~R: 20/ ~ST RUN BE~N: ~q' ~. AND 4-5 ~ 15.~5.1~. UN~ NO ~R~STAN~S ~A~ ~IS $~ DATA BE ~D F~ ANY 0~ ~0~ P~F~ED BY: ~Y HI~.G~Y PAULU~ I D~ HI~ ~R~ ~AT ~lS ~ST WAS P~F~MED IN A~ STA~ AND M~I~PAL ~I~NES IN E~CT ~ ~lS DA~ DA~: 4/30/01 DHI CONSUL'I1NG EN(~NEERS SOILS LO'-PERCOLATiON TEST TEST HOLE #3 ~,,. · · PERFORa~ FOR: ROGER CREMO DATE PERFORUlEO: 3-29-01 ?*~%e.~r- ~°'~.~.*~<;t:~,~~ £C, AL DESORIPTIoN:LOT 3 HILLSIDE NORTH ADD. #9 "~-~',Profess~O~'_~~' ~ 24' ORGANIC SILT W/ ROOT blAT "~'*~,~ SLOPE $~TE PLAN 2 ,3 '0 0 4 ~ .. ~. 8 ~'. CRA¥ $AN0¥ OR^m. W/ IRAC~ -qlLl. RO~< 10 ."o .o i WAS OROUNO WATER S · '~ £NCOUNTERED ? NO L o 0 11 ~ - IF YES, AT WHAT p DEP~ ? E 12 ' 0 DEP~-I OF WA~R ". 0 At ~K MONITORING ? NONE DATE: 4/30/01 15 .;,o .. 0 I 19 PERCOLA~ON RA'I~: 0.21 (MINUIES/INCH.) PERCHOLE DIAMETER: 20 'rEST RUN BE'~N: 4,Q FT. AND 4.5 FT. TII~.E 15,85.180. UNOER NO CIRCIJMSTANCES SHALL ~lfflS SOILS DATA BE USED FOR ANY 01~tER PURPOSE; INCLUDING USE FOR DESIGN OF INDIVIDUAL, ON-SITE SEP~IC SYS~I~4S. PERFORMED BY: d[REblY HIGH. GARY PAULUS. I DIE HIGHC[RllFY 1HAT ~HIS TEST WAS PERFORMED IN ACCORDANC~ WITH ALL STATE ANO MUNICIPAL GUIDELJN£S IN EFFECT ON THIS OATE. DATF~ 4/~0/01 W,O.~ 20¢5~ DHI CONSUL~NO ENClNEERS a,~.~ PE~m~ F~: ROGER CREUO OA~ P~Fm~EO: ~.G~,- ~-~ ~L DE.toP.ON:LOT 4 HILLSIDE NOR~ ADD. ~9 ~ 24' ORGANIC SILT W/ R~T MAT 1 ~ FOZEN TO 12' ~ ~ SLOPE SI~ P~N 2 o I 5 '.o ',, . 0 ' BRO~ ~A~mY SAND W/ ~ACE ~LT. RO~ [ 9 o TO S" ~N S~ZE. .'~ .0 WAS ~R~ND WA~R S 10 · '~ [N~N~R~ ? NO L o 0 11 O' IF ~S, AT ~AT p DEP~ ? E 12 "o DEP~ OF WA~R ". 0 APi~ MONIT~ING ? N~E DA~: 4/50/01 15 - ':o i '0' "~ 17 19 PERi,ON RA~: 9.91 (UINU~S~N~.)PER~ D~A~: 20 -- ~ST RUN BE~: ~ ~. AND 4.5 P~F~ BY: ~Y HI~. ~RY PAULUS. I ~E HI~ ~R~FY ~AT ~IS ~ST WAS P~F~ IN A~RDAN~ A~ STA~ AND M~I~PAL GUI~ IN ~tLCT ~ ~lS DA~. DA~: 4/30/01 W.O.l~ 20459 DHI CONSULI~NG ENGINEERS 800 SOILS L~-PERCO~ON ~ST PERF~M~ F~: ROGER CREMO DA~ P~F~MED: 3-29-01 ~ ~4' ORGANIC SILT W/ ROOT MAT ~ ~O~N TO ~ ~ SLOPE 2 ']'o o 5 .p'- 6 ,.. 7 .:o .- .6-1 0 ' GRA~Y SAND ~A~ ~LT. RO~ 9 o TO ~' ~N ~Z[. ORY ;~ .0 WAS ~R~NO WA~R S 10 ·" ENSNARED ~ NO L o 0 11 O' IF ~S, AT ~AT p DEP~ ? 12 ' 0 DEP~ OF WA~R ". o 15 .',o : 0 16 ~o' i 17~ B.T.H. ~ ~ ~ 18 19 PERi,ON RA~: 0.79 (MINU~S~N~.) 20 PE~ED BY: ~E~Y HI~. GARY PAULUS. I D~ A~ STA~ AND MUNIQPAL ~ID~NE$ IN ~tmCT W.O.~ 20459 DHI CONSULTING ENGINEERS 800 I:' DIMOND ,SUITE .3-54.5 SOILS LOG-PERCOLATION TEST TEST HOLE ~6 PERFOeaED FOe: ROGER CREIdO LEC~L DESCRIPTION: LOT 6 HILLSIDE NORTH ADD. #9 DATE PERFORMED: ~-~g-01 24' ORGANIC SILT W/ ROOT MAT FROZEN TO 12' BROWN SANDY GRAVEL TRACE SILT. ROCK TO 3' IN SIZE. -- B.T.H. - SLOPE WAS GROUND WATER ENCOUNTERED ? NO IF YES. AT WHAT DEPI~{ ? DEPTH OF WATER At IU~ MONITORING ? NONE SITE PLAN I I I I ' I I I S L 0 P E DATE: 4/3o/ol PERCOLATION R^TE: 2.67 (MINUTES/INCH.) PERCHOLE DIAMETER: TEST RUN BETWEEN: 4~1~ FT. AND 4.5 FT. COMMENTS: THi.c; e~t OATA I(~ pgt~nrn rna THF .~ r p[jEpfl~' ~1r ~I:~I(~C:T&~C4~ THAT F'&L"~H IOT i~t'~MPt iIr~ ~qTH ~ITI.E 15.8§.180, UNDER NO CIRCUMSTANCES SHAH 1~115 SOILS DATA BE USeD FOR ANY OTHER PURPOSE; INCLUDING THE USE FOR D[SION C~ INDIVIDUAL, ON-S~1E SEPTIC SYSll[MS. PERFORMED BY: dE~EMY HIGH.GARY PAULUS. ! DIrE HiGH CERTIFY THAT THIS 1EST WAS PERFORMED IN ACCORDANCE W1TH ALL STATE AND MUNICIPAL GUIDE:LINES IN t. rEt. CT ON THIS DALE. DATE: 4/50/01 * DHI CONSULTING ENGINEERS ~MED F~' ROGER CREMO OA~ P~F~MED: 5-29-01 v.~ ,-~._ ~L O[~P~:LOT 7 HILLSIDE NOR~ ADD. ~9 ~ 24' ORGANIC SILT W/ ROOT MAT ~ ~ ~OPE SI~ P~N . BRO~ SAND W/ ~A~ ~LT . SU~Y M~ST i 9 '" .. WAS GR~ND WA~R S 10 . ENSNARED I NO L 11 IF ~S, AT ~AT p DEP~ ? E ~" DEP~ OF WA~R 12 . o J~ AFi~ MONIT~ING ? N~E DA~: o ~ ~ ~ m ORY ~ SU~EY U~ST 18 ~ B'T'H'~ m m m m 20 ~ST RUN B~N: ~,Q ~. AND 5.5 · ~ 15.65.180, UND~ NO ~R~MSTAN~S ~A~ ~lS ~LS OATA ~ U~ F~ ANY O~ER ~ P~ED BY: ~Y HI~.~RY PAULUS. I ~[ HI~ C~FY ~T ~IS ~ST WAS P~F~ IN AC~ANCE ~ STA~ AND MUNIQPAL ~ID~NES IN ~F[CT ~ ~lS DA~ DA~ 4/~/01 * W.O.~ 204.59 800 ~ OlM~O .SUI~ ~ ~'~ SOI~ LO~-P~CO~ON ~ST~~~TH ~L D~IP~: LOT 8 HILLSIDE NOR~ ADD. ~9 '~$7% 1 ~- 24' ORGANIC SILT R~ '" ~OPE SI~ P~N ~ ~L~ ~ND, ~ OROANIC DEBRI I 10 -'~ . ..', O' WAS GR~ND WA~R S' -~'0"~ ~ ~N~ GRAIL EN~N~R~ I NO L ~" ' ' IF ~S, AT ~AT p ... 0 DEP~ ? E .. ..: DEP~ OF WA~R 1~ Q': A~ M~IT~ING ? N~E DA~: 4/30/01 14 -.. O, ' I ~ ~ 1~ ."~0 '.. 1~ - " I 17 . '~0. '~.' lg " ": 20-. "c -S~ ~BE AT 20' PE~ON ~A~:IS (UlNU~S~N~.) PE~ D]A~E~: '~ ~ ~ ~ ~ST RUN BE~N: 6.5 ~. AND 7.0 22 B.T.H. COMMEN~: ~t~ ~ml nATA IR ~n~ r~ ~? ~m r PtmPn~ ~ nm~TX~ ~AT ~A~ I~T ~Pl ~%[ 15.65.180. U~ NO ~R~STAN~$ ~A~ ~l~ ~L5 DATA ~ U~ F~ A~Y O~[R U~ F~ ~ ~ IHDI~DUAL , ~-~[ ~C EE~ED BY: ~R~Y HI~.~RY PAULUS. I DEE HI~ ~fl~ ~AT ~IS ~ST WAS P[~MED IN A~DA~C[ A~ STA~ AND MUNIGPAL ~ID~NES IN [~CT ~ ~lS DA~ DA~ 4/~/01 :--x~' 24' ORGANIC ~,~,-~ SILTY SAND, '.: ','~'~' 12" ORGANIC 0 O. o. .~' '~. SOILS LOG-PERCOLATION TE:ST TH D~IP~ON: ~ 24' ~OZEN ~GANIC SILT W/ E~T MAT ~ ~ SLOPE ~ P~N 0 4 ~' o 0 . 0 8 0 BRO~ ~A~LY SAND 9 0 WAS ~R~ND WA~R S 0 · 0' E 12 ~ a-T.H.~ 15 '1 ~4 20 ~ 15.65.1~. UN~R NO ~R~MSTAN~S ~A~ P~F~ BY: ~EMY HI~.GARY PAU~ A~ ~A~ AND MUNI~PAL ~I~UNES IN E~ ON ~IS DA~. DA~: 4/~/01