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Home My WebLink AboutEND OF THE ROAD S-11592End of the P-oad 511592 E1201411' �k.A l r 4f .Sm iDHI CONSULTING ENGINEERS Engineeringi/ November 11, 2009 W.O.06754 Mr. Ross Noffsinger, P.E Municipality of Anchorage Dept. of Development Services PO Box 196650 Anchorage, Alaska 99519-6650 RE: Preliminary Plat - End of the Road (S-11592) Soils Investigation Report for On Site Septic Systems Dear Mr. Noffsinger, The following report is being submitted for your review and approval in accordance with AMC 21.15.110 and AMC 15.65.180. This project is located in the southeast corner of Section 6, T12N, R3W. (Reference plat numbers 97-113 and 99-133). This subdivision consists of a 45.7 acre tract which is being subdivided into 5 lots and two small tracts (see Appendix'A,' Figure 1). The lots range in size from 3.5 to 11.5 acres with the average lot size being about 9 acres. Of the five lots being created by this plat, two of the lots have existing homes with approved septic systems and wells (see Appendix 'C'). As such, test pits were dug on only three of the five lots (Lots 1, 3, & 4). No testing was conducted on the two small Tracts (Tract A and B), since they cannot be developed. Test pits were dug to a minimum depth of 16.5 feet, or to 2' below the water table (where water was encountered) using a track mounted Hitachi backhoe. Soils were visually classified, and a four inch perforated monitoring tube was placed in each test pit. The soils consisted primarily of slightly silty sands to slightly silty sandy gravels which were overlaid by a foot of organic sands/silts and root material. No bedrock was encountered in any of the holes. Detailed soils information for each lot can be found on the Soils Log in Appendix 'B'. Percolation tests were performed on each lot in accordance with MOA guidelines. The soils on each lot percolated at rates around 1 minute per inch. For those lots which percolated faster than 1 minute per inch, a sand filter will be required; however, the existing material will most likely meet M.O.A. gradation requirements for sand filters. Small seeps of water were initially encountered on lots 3 and 4. Both of these seeps stopped flowing within a short time of being exposed. After monitoring over several years (through the spring, summer and fall), groundwater was present only on Lot 1. The water level after monitoring for Lot 1 was 13.0 feet below the surface. Dimond Center Tower, 5" Floor • 800 East Dimond Blvd. Suite 3-550 • Anchorage, Ak. 99515 Ph (907) 344-1385 • Fax (907) 344-1383 • Email: admin@dhialaska.com SERVING ALASKA SINCE 1985 Based on the percolation rates, AMC Title 15.65.180.B.1 (Subdivision Standards), Table 2, requires all lots have a minimum of 10,000 square feet. Figure I (Appendix'A') shows the location of the reserve area for each lot. In summary, there is adequate area on each of the lots for an on site septic system, the required reserve areas, a domestic well, house and driveway. This subdivision as proposed meets all the requirements as established by AMC 15.65.180 and AMC 21.15.110. Enclosure cc: Ghislaine Cremo acldh 754se"creportr Ve truly yours, tory Engineers Dee High, P. . Principal *.:49 ••as•••••••••u••••. . T 'p • DEE HIGH. gyp„•, .; i .'meg^ • CE - 5807 W.O.# 06754 DHI CONSULTING ENGINEERS 800 E. DIMOND BLVD. SUITE 3-545 A ANCHORAGE, ALASKA 99515 SOILS LOG -PERCOLATION TEST AV i TEST HOLE LOG LOT 1 i . rn : DEE HICyK(� I; g� ROGER CREMO 9 19 9''• p�/ PERFORMED FOR: DATE PERFORMED: �2006'(1�/`er•••, LV •8••,•\�C�'� LEGAL DESCRIPTION: LOT 1 END OF THE ROAD SUBDIVISION �4% PrOfesS% T.H. LOT 1 Date: it F IFN THIS DATA IS PROVIDED TO MEET THE REQUIREMENTS FOR j7, 912" ORGANIC MAT SUBDIVIDING THE PROPERTY. THIS TEST HOLE DATA MAY NOT 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 18" ORGANIC SILT SLIGHTLY SILTY SANDY GRAVEL F-1 p OCCASIONAL ROCK TO 5" a / WAS GROUND WATER S a'. 0 SEEP 0 10.5' ENCOUNTERED ? YES L IF YES, AT WHAT 0 DEPTH ? 10.5' P E DEPTH OF WATER AFTER MONITORING ? 13.0' DATE: 10-16-09 BE USED FOR THE DESIGN OF AN ON-SITE SEPTIC SYSTEM WITHOUT THE WRITTEN CONSENT OF THE ENGINEER. SLOPE SITF PI AN B.O.H. PEAo1N0 DALE aR033 191E NET 1wE mm MET Haar POMMM PRESOAK 9/19/96 - 6:15 12' 12' PRESOAK 9/19/06 6:12 12' 12' 1 9/19/06 6:07 6' 6' 1.92 2 9/19/06 6:21 6' 6' 1.06 3 9/19/06 6:23 6' 6' 1.06 4 9/19/06 6:27 6' 6' 1.05 PERCOLATION RATE: 1.08 (MINUTES/INCH.) PERCHOLE DIAMETER: 6" TEST RUN BETWEEN: 3.5 FT. AND 4.0 FT. PERFORMED BY: DEE HIGH 1 CERTIFY THAT THIS TEST WAS PERFORMED IN ACCORDANCE WITH ALL STATE AND MUNICIPAL GUIDELINES IN EFFECT ON THIS DATE. DATE: 10-19-2009 754THL6D W.O.# 06754 DHI CONSULTING ENGINEERS 41-- • 800 E. DIMOND BLVD. SUITE 3-545 AVQ` . ANCHORAGE, ALASKA 99515 � "' SOILS LOG—PERCOLATION TEST TEST HOLE LOG LOT 3 wo "' PERFORMED FOR: ROGER CREMO • CE 5807 DATE DATE PERFORMED: 9-19-2006 �`�P�e••�••••••• LEGAL DESCRIPTION: LOT 3 END OF THE ROAD SUBDIVISION A,'PrOfesSlof°�'o� T.H. LOT 3 Dater _ 6" ORGANICS THIS DATA IS PROVIDED TO MEET THE REQUIREMENTS FOR SUBDIVIDING THE PROPERTY. THIS TEST HOLE DATA MAY NOT 1 BE USED FOR THE DESIGN OF AN ON-SITE SEPTIC SYSTEM 12" REDDISH ORGANIC SILTS WITHOUT THE WRITTEN CONSENT OF THE ENGINEER 2 3 4 5 / 6 / / 7 SLIGHTLY SILTY SANDY GRAVEL 8 / F-1/NFS SMALL SEEP 0 16.5' / 9 10 11 / / 12 D % 13 14 15 D/ / 16 B.O.H. 17 SLOPE SiTF vi AN WAS GROUND WATER S ENCOUNTERED ? YES L IF YES, AT WHAT O DEPTH ? 16.5' P DEPTH OF WATER E AFTER MONITORING ? NONE DATE 10-1s-09 18 19 PERCOLATION RATE: 0.94 (MINUTES/INCH.) PERCHOLE DIAMETER: 6- 20 TEST RUN BETWEEN: 4.0 FT. AND 4.5 FT. COMMENTS, SEEP STOPPED AFTER A FEW MINUTES. PERFORMED BY: I CERTIFY THAT THIS TEST WAS PERFORMED IN ACCORDANCE WITH ALL STATE AND MUNICIPAL GUIDELINES IN EFFECT ON THIS DATE. DATE: 10-21-2009 754THL4D W.O.# 06754 DHI CONSULTING ENGINEERS 800 E. DIMOND BLVD. SUITE 3-545 ANCHORAGE, ALASKA 99515 Ar SOILS LOG—PERCOLATION TEST Ar TEST HOLE LOG LOT 4 iq m DEE HIGH i PERFORMED FOR: ROGER CREMO ♦#� �'. CE 5807 DATE PERFORMED: 9/19/06 ��fe .'., .•'( i LEGAL DESCRIPTION: LOT 4 END OF THE ROAD SUBDIVISION ��; )'_ofessjoo T.H. LOT 4 Date: 16" ORGANICS THIS DATA IS PROVIKQ�DD TO MEET THE REQUIREMENTS F6R SUBDIVIDING THE PROPERTY. THIS TEST HOLE DATA MAY NOT 16" RED ORGANIC SILTS BE USED FOR THE DESIGN OF AN ON-SITE SEPTIC SYSTEM WITHOUT THE WRITTEN CONSENT OF THE ENGINEER. 2MSLOPE SITE PLAN 3 a 4 5 6 7 8 9 Fli 0 10 4- 11 12 r Z. 13 /. 14 15 16 17 18 19 20 SANDY GRAVEL TRANSITION TO SLIGHTLY SILTY SANDY GRAVEL W/ DEPTH F—i/NFS OCCASIONAL ROCK TO 6" WAS GROUND WATER S ® 10.5' ENCOUNTERED ? YES L IF YES, AT WHAT 0 DEPTH ? 10.5' E DEPTH OF WATER E AFTER MONITORING ? NONE DATE: 10-19-2009 SILTY SAND I KolmI PERCOLATION RATE: 1.06 (MINUTES/INCH.) PERCHOLE DIAMETER: 6" TEST RUN BETWEEN: 4.0 FT. AND 4.5 FT. COMMENTS- SEEP STOPPED AFTER A FEW MINUTES. PERFORMED BY: DEE HIGH I CERTIFY THAT THIS TEST WAS PERFORMED IN ACCORDANCE WITH ALL STATE AND MUNICIPAL GUIDELINES IN EFFECT ON THIS DATE. DATE: 10-21-2009 754THL5D CHUGACH STAT_ PARK VICINITY MAP 1"=1 MILE \ _ ----- DRAINAGE—_HANNEL •'/ \ I sl I x I x I JI I 2 -,..-.,aeo EXIST. SEPTIC,i� - '4TL`�is'�.`� 1 CHANNELS � - a J / '\--•�''1,,,,, LOT 1 PRO -sem... �.;.:.i EX i LL j I I S 1 �• i e Y / PROPOSED ELL LOT 2 N HOUSE sEXI LOT 2A >Ae /"SITE�' f -I- 10 11 I t: e DRAINAGE �CHANNELS _j L"° —1 INc H uSe � ISO,( — - NOTES: p -1'115 ._._� r _. I I - 'i \., -...................... 1. LOTS 2A & 2 HAVE EXISTING WELLS AND l _ 10,000 S.F-"L•••'" 1 -'! SEPTIC SYSTEMS WHICH HAVE BEEN - - - - - - - - PROPOSED APPROVED BY M.O.A. ON-SfTE SERVICES ` - -- - - -" - HOUSE SftE / x - EAT. SE . - �M � . - > <-r4�_ \ - 2. TRACTS A k 8 CANNOT BE DEVELOPED SYSTEMS -'ovr /.. / T 3 - AS RESIDENTIAL HOME SITES. a'sipp ,e• _ - ''' / 10,000 S.1( - 3. LOT 1, 3 k 4 MEET THE REQUIREMENTS A.M.C. 21.15, 21.55 AND 21.65. G7�dd�OD� WOOG C3D WE P / Qa®�a _ LOT 3\,m, LOT 4 R� 1� 10000 S.F. - LOT $ o ,LOT 2 \ \ / 1� ,r PROP SE- Z 3db�G3 WELL, Ho_u�PE j _ y WELL, S1iN LEGEND SYMBOL DESCRPTION.. SUBDIVISION BOUNDARY - - INTERIOR PROPERTY UNE DRAINAGE CHANNEL TEST HOLE k NUMBER �{ '•.Y^...i;:;i:.� PROPOSED SEPTIC AREA PROPOSED WELL WITH 100' PROTECTIVE WELL RADIUS. 4. i g>R�e7e1 •., vrvi lY n12. FIGURE 1 Dffi CONSULTING ENGINEERS am . 11011111111m KAMM LOT - T leph « ("TA" -Ism rm tompu-,aea LOT 6 see sm e�5e • u&(9 a ses 200 0 200 400 END OF THE ROAD Ii i i I I I I QQOgp QD° LOT 5 ON-SITE SEPTIC MAP Distances are shown in feet. f8 m wio 2143 ax,cr I" - 200'. °� 11 05 7540081E i w 06754 1 D H I CONSULTING ENGINEERS Civil Engineering • Surveying • planning Mr. Dan Roth ' Municipality of Anchorage Building Safety Division Development Services Department - On -Site Supervisor ' P.O. Box 196650 Anchorage, Alaska 99519-6650 RE: Preliminary Plat - End of the Road Domestic Water Availability Dear Mr. Roth, October 5, 2006 W.O.: 06754 811592 JUN 1 69W The proposed subdivision consists of 5 lots ranging from 3.6 acres to 13.3 acres; and one tract that is 2.9 acres. This property is zoned R10SL, which encourages large lots and low density development. This property is abutted on the South and East by Chugach State Park. No further development can take place in those directions and there can be no development on the 2.9 acre tract. Two of the five proposed lots already have wells (Lot 2A, Block 5 and Lot 1). They produce about 30 gpm and 6 gpm respectively. The proposed development will require three additional wells. Water availability in this area has been excellent. The static water level ranges from 27' to 162' below the surface. Flow rates are reported to range from 3gpm to 50gpm. Well depths are ranging from 60' to 427'. Most of the wells are finding water in the bedrock aquifer. We expect that lots on this subdivision will encounter bedrock between 30' to 100' below the surface. To date, all bedrock wells have produced adequate supplies of water. The geology in this area of the watershed consists of glacial till over weathered, fractured bedrock. The existing bedrock aquifer has not shown any signs of being depleted and the addition of three more wells will not over stress the aquifer. Due to the make up of the aquifer, the large distance between the individual wells and low density development, this development will not impact the existing wells in adjacent subdivisions. We would appreciate your approval of the preliminary plat. Attachmem:. =Roger Cremo 754waterreport.wpd truly yours, �"sulting Engineers Dee High, P Principal Legal Description Hillside North Home Tract Static Water Level 42 feet Depth of Well 66 feet Production Rate 6 gpm Hillside North #1 Lott 150 feet 410 feet 5 gpm Hillside North #1 Lot2 162 feet 200 feet 8 gpm Hillside North #5 BIk3 Lot4 95 feet 205 feet 4 gpm Hillside North #5 BIk3 Lot5 73 feet 120 feet 6 gpm Hillside North #7 BIM Lott 27 feet 365 feet 4 gpm Hillside North #7 BIk4 Lot3 45 feet 107 feet 5.4 gpm Hillside North #7 BIk4 Lot4 88 feet 427 feet 3 gpm Hillside North #7 BIk5 Lot2 47 feet 245 feet 30 gpm Hillside North #7 BIk5 Lot3 50 feet 340 feet 3 gpm Hillside North #8 BIk4 Lot6 42 feet 61 feet 50 gpm Hillside North #8 BIk5 Lot4 55 feet 60 feet 12 gpm Taiga Lot2 119 feet 220 feet 5 gpm Taiga Lot6 60 feet 190 feet? 8 gpm Legal Description Hillside North Home Tract Static Water Level 42 feet Depth of Well 66 feet Production Rate 6 gpm Hillside North #1 Lott 150 feet 410 feet 5 gpm Hillside North #1 Lot2 162 feet 200 feet 8 gpm Hillside North #5 BIk3 Low 95 feet 205 feet 4 gpm Hillside North #5 BIk3 Lot5 73 feet 120 feet 6 gpm Hillside North #7 BIk4 Lott 27 feet 365 feet 4 gpm Hillside North #7 BIk4 Lot3 45 feet 107 feet 5.4 gpm Hillside North #7 BIk4 Lot4 88 feet 427 feet 3 gpm Hillside North #7 BIk5 Lot2 47 feet 245 feet 30 gpm Hillside North #7 BIk5 Lot3 50 feet 340 feet 3 gpm Hillside North #8 BIk4 Loth 42 feet 61 feet 50 gpm Hillside North #8 BIk5 Lot4 55 feet 60 feet 12 gpm Taiga Lot2 119 feet 220 feet 5 gpm Taiga Lot6 60 feet 190 feet? 8 gpm Average Total 94.5 243.5 26.5