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HomeMy WebLinkAboutRIVERPARK VIEW S12317 Onsite File Riverpark View #512317 ANDERSON ENGINEERING P.O. BOX 240773 ANCHORAGE, AK 99524 522-7773 677-7766 (FAX) February 6, 2017 Municipality of Anchorage Building Safety Division On Site Water and Wastewater Program 4700 Elmore Street Anchorage,AK 99507 Attention: Debbie Wockenfuss Subject: Riverpark View Subdivision, S-12317 Septic System Feasibility Study Dear Debbie: A petition has been submitted to subdivide three lots into eight, forming the new Riverpark View Subdivision (Platting case S-12317) The parcel will be divided into individual lots with one of the lots currently occupied, and two of them with homes and septic systems under construction. We our presenting our findings that each new lot will have sufficient area and potential for on- site wells and septic systems. The property in general is moderately sloped, towards the southwest in general, at grades ranging from 10% up to around 30%. Most of the area is in the 15-20% range, with only a few portions steeper than 25%. No septic systems are proposed on the steeper slopes or within 50' uphill of them. Lot sizes are greater than 1 acre each (43,560 SF), and the attached site plan demonstrates that there is enough space available to meet separation requirements for the wells and future septic systems. Test holes were dug on May 19, 2016. Two test holes were placed on each vacant lot, in areas that seemed to be possible for septic locations. Monitoring tubes were placed in the test holes, and groundwater checked a week later, on May 28th and 29`h. The test holes were dug down to close to 18' in each case (please refer to attached test hole logs). No groundwater was found in any of the test holes. Test holes found no bedrock or impermeable soil lenses. Soils were very uniform in the area, consisting entirely of silty gravel with sand (GM/GW). Percolation benches were constructed between 4-5' below the ground surface in each test hole. The percolation cavity in each bench was prepared and presoaked in accordance with municipal requirements. Again, Riverpark View Subdivision February 6,2017 Page 2 results were very uniform in the area, with all perk tests results falling between 1-5 min/in. Individual test results are including in the attached test hole information. According to code, this equates to 10,000 SF of septic reserve area per lot, which has been designated on the accompanying site plan (with the exception of lots that are in the process of development and therefore have designed systems in place). On one of the lots (proposed Block 2 Lot 2), the preliminary test holes are placed in locations that are now unsuitable for septic area(due to proximity to a steeper slope and the well drilled on Lot 3). However, the uniformity of the soils in the entire subdivision strongly indicates that this will not be a problem. The proposed septic area is located less than 50' away from the closest test hole. We do not anticipate having any problem with impermeable soils or groundwater, and the 10,000 SF indicated will easily support a system for the future home. Based on our field study and water monitoring completed to date it is clear that all lots of the proposed subdivision are capable of supporting an onsite septic system. Sincerely, der :l ay '\�....nes 4.Cr 1•�, Benjamin Schiller, P.E. �' , T_•`f '7 Attachments Bei .1 • 4 k011%%‘-re..,' k iFEssi:kt ____ _7 i , ' __Kz,, _-- / -----_ _4 /% Ft) EXISTING SEPTIC SYSTEM (APPROX) '• • IEXISTNc (APPROX) , .. ` •` `• �� —` /' E10STING tttllj I 10 -A\\ 4.' i V76. I /.,. "‘ - ,-- i0,-NVS\---.\ . '..i ..5 5,, -, -------:_,‘\ ,,. \----I Th...! ...7., 7".....„ \ Y 11` P .'. \\ ,1,/ a� � " _I � �� LT3, II\ I , � i - C` �' i i\ :.\\\...,1 \ \4\\ /' LOT 2 • l \ \y I I �0� \ °s / pl=i1 1 •`, \ Co ' z 1 I 1 \ 1Qlr 8L �� { i i 100'F "T' TM UNE :-.......\‘.....s...'..... ...... * `� I I ----LOT 1 j i -`\` ll � 0' ,,,,\ `\ . ...... ` •... \ wry\ `� 1 � � �y. / Zz {; . . VE1tiED 1?IAT � NOR1N OF � `.,.....r.././ \R?`' I 1F� , 1 • NOT 011 TIE \,� }_.._ �•s% ..--- t SL• - a OM!THE E)OSTNNr, _�E R _ -_��„�� f LOT 1 I I \ .” / I �\ • \ A 1' 1111. 1 �• \ I 1. L ` I �. • \-\\...... j --__ , _ 47_, ..,..,....s...\\N„.........„.:\N„ 14::?\i c\\.- ..- N. I i ©C \ \ {. 0 7� -/-"p ,' / i ---- .../ /...../ . _ylOTi2 /Prii, j 6`M ��°3* ! nig• TNno . 1 • ,_ /1,,,,,,, ,...„), ....,..... , 7 ,, , .... , ‘ , , , \ , , _ . , __ ______._______________I . , 4'4044., ..,---- \„.______,\j i?//,..,.... \. \\ / 4'1 2,43-';v- \\'- 04,4 " In- 1 s .' TH,4_.C7' ` LOT I i i_. - ��0 13. A ♦ s 7 1 \`N. EXI -._.--. STINGSEPTIC SYSTEM I \ PLAN VIEW NOTE: TIE FOLLONNG ADJACENT PROPERTIES HAVE BEEN NVESITGATED.ALL SEPTIC SCALE: 1" = 100' SYSTEMS AND 100'WELL RAD.511HN MAP BOUNDARIES ARE SHONt,. 1.BOB TIEI.LS SUB,BLOCK 1 LOT 5 GRADING PLAN LEGEND " n1a TNSUB,LOT 4.CHARD SUB,TRACT A-3-A A CHARUCE SUB,TRACT A-3-C B. CHARUCE SUB,TRACT 8-1 (FIELD-LOCATED) PROPOSED WELL LOCATION 7. CHARUCE SUB.TRACT C-tA1-2A B. THIN Raw SEC 25 N2HW4 NORTH OF EAGLE RIVER ROAD t' TEST HOLE LOCATION SEPTIC RESERVE AREA: 10,000 SF/PROPERTY EXISTING CONTOUR (2') CALL BEFORE YOU DIG VERIFY RECORD DRAWING Note: To be filled out on original drawings upon project completion. wy EXISTING CONTOUR (10') E COMPEER*MU Nom.ALL AKA Y catWAWS 1. DATA PROVIDED BY: 3.Based on periodic field obeervotions by the 4EOF•elq TI PROPOSED CONTOUR2' POOR 70 CO'eOK00'r Or EXCAVATOR 17E MOMS SCALE P•• S CONTOUR(2') b A►ARMC USE Thb will serve to certify that these Record Engineer (or an Ndh4duol under his/her direct 4. I-\Jr PROPOSED CONTOUR(10') ALASKA DIG UNE -811 Drawings ore a true and accurate supervision), the Contractor-provided data TROY DAVIS HOMES.INC ANDERSON ENGINEERING 49 x :* RIVERPARK VIEW ESTATES SUBDIVSION THIS BAR REPRESENTS representation of the project ow constructed. appears to represent the project as constructed. ••• ••i• •• •• PROPOSED SPOT ELEVATION LOCATE CALL CENTER OF ALASKA 278-3121 HALF NCH ON CONTRACTOR: 155 E PARKS HWY.STE 200 PO BOX 240773 - A FUTURE DRAINAGE PATTERN MELONS Aam s AM.CEA 04 WWI A1M110N/1[Saep ORIGINAL DRAWING. BY: TITLE: DATA TRANSFER CHECKED BY: ANCHORAGE. AK 99554 ANCHORAGE. AK 99524 ''••i k,,,,r, NO ca AW iO1NS'VOA f0�n'�1S' 0.8 .1/2" DATE: BC�MPANY: TIS• 907-310-2501 907-522-7773 l•'.- ' i�7�`1•E SUBDIVISION WELL & SEPTIC PLAN liggeligTO STATE STORM/STREET UGHTS 333-2411 W BAR IS NOT HALF 2. DATA TRANSFERRED BY: DATE: D�acss "' WAGE t•�t00 'DAM - 2017 coo: Sw tii2e C MILITARY PETROLEUM LINES 862-4112 INCH, ADJUST DRAWING COMPANY: SCAM 1' - 100' SCALE ACCORDINGLY. DATE: OWNER CONSULTANT SEAL 'PLATTING CASE/5-12317 SHEET .p MUNICIPALITY OF ANCHORAGE DEVELOPMENT SERVICES DEPARTMENT /�Q,•,•• `i ,��+� 4700 BRAG AW STREET ANCHORAGE, AK 99519-6650 *:49TH SOILS LOG - PERCOLATION TEST • % IA .�� B: in Schiller : �P'sF • L 12592 �, / LEGAL DESCRIPTION: LOT I, BLOCK I, RIVER PARK VIEW SUB. •• �•Ian17.2017 •'c��' ir, OFESSIOHP���S PERFORMED FOR: TROY DAVIS HOMFS k\FFk �PRoFESs`i+ DATE: 5/19/16 PROJECT No.: PARCEL ID#: TECHNICIAN: W. ROBERTS Professional Engineers Stamp: DEPTH TEST HOLE 1 (feet) OB/OG SLOPE SITE PLAN 1 ° 2 3 °. 4 5 SEE SITE PLAN • ° • 6 4 • 7 a . n 8 • . • • SILTY GRAVEL WITH SAND 9 a 4 GM/GW WAS GROUND WATER ENCOUNTERED? NO •10 IF YES @ WHAT DEPTH', S. • DEPTH OF WATER AFTER MONITORING: NONE L 5% 11 ° • DATE OF MONITORING: 5/28/16 •12 GROSS TIME NET TIME DEPTH TO NET DROP 13 .° DATE READING (MINUTES) (MINUTES) WATER (INCHES) . M (INCHES) • 14 .4 . TEST HOLE PRESOAKED PRIOR TO TESTING: • 15 • • 5/28 1 9:04/9:14 10 0.75"/3.50" 2.75tt 4 2 9:15/9:25 10 0.50"/3.25" 2.75" 16 • 3 9:27/9:37 10 0.50"/3.2511 2.75" 17 •• ° 49:38/9:48 10 0.38"/3.13" 2.75" 18 " BOH @ 18' 5 9:49/9:59 10 035"/3.50" 2.75" 19 6 10:01/10:11 10 0.50"/3.25" 2.75" 20 PERCOLATION RATE: 3.6 (MIN/INCH) PERC. HOLE DIA. 6" (INCHES) TEST RUN BETWEEN: 4 FT. and 5 FT. COMMENTS: TEST HOLE PRE SOAKED PRIOR TO TEST. TEST PERFORMED BY ANDERSON ENGINEERING. I,MICHAEL E. ANDERSON CERTIFY THAT THIS WAS PERFORMED IN ACCORDANCE WITH ALL STATE AND MUNICIPLE GUIDELINES IN EFFECT ON THIS DATE: 6/13/16 MUNICIPALITY OF ANCHORAGE DEVELOPMENT SERVICES DEPARTMENT ...... 49,, 11+ 4700 BRAGAW STREET ANCHORAGE, AK 99519-6650 9 0 *. 49TH /'\ •* p/ SOILS LOG - PERCOLATION TEST . Be 1 in Schiller • LEGAL DESCRIPTION: LOT I, BLOCK I, RIVER PARK VIEW SUB. +,�F�isl'•,:=�in 05hiIIe92 r / PERFORMED FOR: TROY DAVIS HQMFS Ik\ D, ROFESSIONP� DATE: 5/19/16 PROJECT No.: \\\`�� PARCEL ID#: TECHNICIAN: W. ROBERTS Professional Engineers Stamp: DEPTH TEST HOLE 2 (feet) OB/OG SLOPE SITE PLAN 1 d 2 3 a d• 4 • 5 ° SEE SITE PLAN • 4 6 4 7 a . 8 • " SILTY GRAVEL WITH SAND 9 —nd a GM/GW 10 ° WAS GROUND WATER ENCOUNTERED? NO IF YES @ WHAT DEPTH'' DEPTH OF WATER AFTER MONITORING: NONE 1 1 d DATE OF MONITORING: 5/28/16 12 .° ••< GROSS TIME NET TIME DEPTH TO NET DROP 13 DATE READING (MINUTES) (MINUTES) WATER (INCHES) • .d (INCHES) 14 ° TEST HOLE PRESOAKED PRIOR TO TESTING: 15 • 5/28 1 11:10/11:2C 10 1.13"/4.13"4 3.00" 2 11:21/11:31 10 1.25"/4.25" 3.00" 16 3 11:32/11:42 10 1.13°/4.13" 3.00" 17 4 ° 11:43/11:53 10 I.50'/4.50" 3.00" 18 • BOH @ 18' 5 11:54/12/04 10 1.25"/4.25" 3.00" 19 6 12:05/12:15 10 1.13'14.13" 3.00" 20 PERCOLATION RATE: 3.3 (MIN/INCH) PERC. HOLE DIA. 6" (INCHES) TEST RUN BETWEEN: 4 FT. and 5 FT. COMMENTS: TEST HOLE PRE SOAKED PRIOR TO TEST. TEST PERFORMED BY ANDERSON ENGINEERING. I,MICHAEL E. ANDERSON CERTIFY THAT THIS WAS PERFORMED IN ACCORDANCE WITH ALL STATE AND MUNICIPLE GUIDELINES IN EFFECT ON THIS DATE: 6/13/16 MUNICIPALITY OF ANCHORAGE � ) DEVELOPMENT SERVICES DEPARTMENT r'_ 4"`ti ;,,��1 4700 BRAGAW STREET ANCHORAGE, AK 99519-6650 497H i\ 4-4 SOILS LOG - PERCOLATION TEST ;t,,:„j Ben' n Schiller LEGAL DESCRIPTION: LOT 2, BLOCK I, RIVER PARK VIEW SUB. S1`` l�.., Ja++?2592 ••��/� PERFORMED FOR: TROY DAVIS HOMES ��ilF PROFESSION`�' DATE: 5/19/16 PROJECT No.: \\\��`~.� PARCEL ID#: TECHNICIAN: W. ROBERTS Professional Engineers Stamp: DEPTH TEST HOLE 3 (feet) 1 OB/OG SLOPE SITE PLAN 4 2 ° • 3 d Q. 4 5 SEE SITE PLAN 4 6 d . • 7 4 . a 8 • . ' • SILTY GRAVEL WITH SAND 9 °a :d GM/GW WAS GROUND WATER ENCOUNTERED? NO 10— ° IF YES Ca WHAT DEPTH', S DEPTH OF WATER AFTER MONITORING: NONE b 1 1 • DATE OF MONITORING:_5/28/16 • 12 GROSS TIME NET TIME DEPTH TO NET DROP 13 n DATE READING (MINUTES) (MINUTES) WATER INCHES) (INCHES) • 14 -° . • TEST HOLE PRESOAKED PRIOR TO TESTING: • 15 • 5/28 1 1:06/1:16 10 0.75"/3.25" 2.50" 4 2 1:17/1:27 10 o.so°/3.00° 2.50" 16 • ' 3 1:28/1:38 10 0.75"/3.25" 2.50" 17 ° 4 1:39/1:49 10 0.88"/3.38" 2.50" 18 BOH @ 18' 5 1:50/2:00 10 0.75"/3.25" 2.50" 19 6 2:01/2:11 10 0.75"/3.25" 2.50" 20 PERCOLATION RATE: 4.0(MIN/INCH) PERC. HOLE DIA. 6" (INCHES) TEST RUN BETWEEN: 4 FT. and 5 FT. COMMENTS: TEST HOLE PRE SOAKED PRIOR TO TEST. TEST PERFORMED BY ANDERSON ENGINEERING. I,MICHAEL E.ANDERSON CERTIFY THAT THIS WAS PERFORMED IN ACCORDANCE WITH ALL STATE AND MUNICIPLE GUIDELINES IN EFFECT ON THIS DATE: 6/13/16 MUNICIPALITY OF ANCHORAGE ,�(�OF, X111 DEVELOPMENT SERVICES DEPARTMENT .• 4700 BRAGAW STREET ANCHORAGE, AK 99519-6650 Ae�* TM ted' *�j SOILS LOG - PERCOLATION TEST Bea in Schiller LOT 2, BLOCK I, RIVER PARK VIEW SUB. c� LEGAL DESCRIPTION: 01-1<-'s�l �L7 p?2 ..• P 1 \: PERFORMED FOR: TROY DAVIS HOMES \���"`PROFESS DATE: 5/19/16 PROJECT No.: Professional Engineers Stamp:ID#: TECHNICIAN: W. ROBERTS DEPTH TEST HOLE 4 (feet) 1 OB/OG SLOPE SITE PLAN d 2 3 d 4 5 SEE SITE PLAN d 6 4 . 7 d 8 • . ' • SILTY GRAVEL WITH SAND 9 -a GM/GW 10 v WAS GROUND WATER ENCOUNTERED? NO IF YES L WHAT DEPTH' DEPTH OF WATER AFTER MONITORING: NONE 11 d DATE OF MONITORING: 5/28/16 •12 •'� GROSS TIME NET TIME DEPTH TO NET DROP 13 d DATE READING (MINUTES) (MINUTES) WATER (INCHES) (INCHES) 14 .` • TEST HOLE PRESOAKED PRIOR TO TESTING: 15 • • 5/28 1 2:33/2:43 10 0.75"14.88" 4.13" d 2 2:44/2:54 10 o.75"/s.oO" 4.25" 16 3 2:55/3:05 10 0.63"/4.88" 4.25" 17 ... d 4 3:07/3:17 10 0.50°/4.63^ 4.13" 18 • BOH @ 18' 5 3:18/3:28 10 4.25" o.75"/s.00� 19 6 3:29/3:39 10 0.63"/4.88" 4.25" 20 PERCOLATION RATE: 2.2 (MIN/INCH) PERC.HOLE DIA. 6" (INCHES) TEST RUN BETWEEN: 4 FT. and 5 FT. COMMENTS: TEST HOLE PRE SOAKED PRIOR TO TEST. TEST PERFORMED BY ANDERSON ENGINEERING. I,MICHAEL E.ANDERSON CERTIFY THAT THIS WAS PERFORMED IN ACCORDANCE WITH ALL STATE AND MUNICIPLE GUIDELINES IN EFFECT ON THIS DATE: 6/13/16 MUNICIPALITY OF ANCHORAGE DEVELOPMENT SERVICES DEPARTMENT v•�,'•• 4- I 4700 BRAGAW STREET ANCHORAGE, AK 99519-6650 i*149111 SOILS LOG - PERCOLATION TEST . Ben• -In Schiller l+�Fc•. AEL 12592 •``t% LEGAL DESCRIPTION: LOT 3, BLOCK I, RIVER PARK VIEW SUB. 11 ��• ;��7.p1�,.•��V� PERFORMED FOR: TROY DAVIS HOMES ik oFES`'0 i DATE: 5/19/16 PROJECT No.: PARCEL ID#: TECHNICIAN: W. ROBERTS Professional Engineers Stamp: DEPTH TEST HOLE 5 (feet) OB/OG SLOPE SITE PLAN 1 2 3 4 • 5 ° SEE SITE PLAN • 4 6 4 • 7 a . a 8 SILTY GRAVEL WITH SAND 9 a :.4. GM/GW WAS GROUND WATER ENCOUNTERED? No I 0 ° IF YES L WHAT DEPTH/ S DEPTH OF WATER AFTER MONITORING: NONE 11 d DATE OF MONITORING: 5/2$/16 •12 ° ••< GROSS TIME NET TIME DEPTH TO NET DROP 13 d DATE READING (MINUTES) (MINUTES) WATER (INCHES) INCHES) 14 ° • TEST HOLE PRESOAKED PRIOR TO TESTING: 15 • • 5/28 1 4:00/4:10 10 1.13"/4.50" 3.37" 4 2 4:11/4:21 10 1.25"/4.63" 3.38" 16 3 4:22/4:32 10 1.00'/4.38" 3.38" 17 • 4 4:33/4:43 10 1.25"/4.63" 3.38" 18 • BOH @ 18' 5 4:44/4:54 10 I.00"/4.38" 3.38" 19 6 4:55/5:05 10 1.25"/4.63" 3.38" 20 PERCOLATION RATE:2.96(MIN/INCH) PERC. HOLE DIA. 6" (INCHES) TEST RUN BETWEEN: 4 FT. and 5 FT. COMMENTS: TEST HOLE PRE SOAKED PRIOR TO TEST. TEST PERFORMED BY ANDERSON ENGINEERING. I,MICHAEL E.ANDERSON CERTIFY THAT THIS WAS PERFORMED IN ACCORDANCE WITH ALL STATE AND MUNICIPLE GUIDELINES IN EFFECT ON THIS DATE: 6/13/16 MUNICIPALITY OF ANCHORAGE � ll DEVELOPMENT SERVICES DEPARTMENT /g • ' �,, 4700 BRAGAW STREET ANCHORAGE, AK 99519-6650 • %*:49TM .„ * i, SOILS LOG - PERCOLATION TEST r • ►�• •ii j Be 1!in Schiller LOT 3, BLOCK I, RIVER PARK VIEW SUB. vO,�`c•• AEL .217 � � LEGAL DESCRIPTION: I�F�F�PROFESSti0Np1 PERFORMED FOR: TROY DAVIS HOMES N\\\\S DATE: 5/19/16 PROJECT No.: PARCEL ID#: TECHNICIAN: W. ROBERTS Professional Engineers Stamp: DEPTH TEST HOLE 6 (feet) OB/OG SLOPE SITE PLAN 1 ° 2 3 a ° 4 5 C SEE SITE PLAN • ° • 6 4. •. • 7 ° 8 • SILTY GRAVEL WITH SAND 9 -a a GM/GW 10 C WAS GROUND WATER ENCOUNTERED? NO IF YES(2 WHAT DEPTH', S • DEPTH OF WATER AFTER MONITORING: NONE b 1 1 ° DATE OF MONITORING: 5/28/16 • 12 GROSS TIME NET TIME DEPTH TO NET DROP 13 ° DATE READING (MINUTES) (MINUTES) WATER (INCHES) ((INCHES) 14 •C TEST HOLE PRESOAKED PRIOR TO TESTING: • 15 • 5/28 1 5:14/5:24 10 0.75"/4.50" ° 16 2 5:25/5:35 10 0.75"/4.50" 3.75" 3 5:36/5:46 10 0.63"/4.38" 3.75" 17 4 4 5:47/5:57 10 0.50"/4.25" 3.75" 18 BOH @ 18' 5 5:58/6:08 10 0.50"/4.25" 19 6 6:09/6:19 10 0.75"/4.50" 3.75" 20 PERCOLATION RATE:2•7 (MIN/INCH) PERC. HOLE DIA. 6" (INCHES) TEST RUN BETWEEN: 4 FT. and 5 FT. COMMENTS: TEST HOLE PRE SOAKED PRIOR TO TEST. TEST PERFORMED BY ANDERSON ENGINEERING. I,MICHAEL E. ANDERSON CERTIFY THAT THIS WAS PERFORMED IN ACCORDANCE WITH ALL STATE AND MUNICIPLE GUIDELINES IN EFFECT ON THIS DATE: 6/13/16 MUNICIPALITY OF ANCHORAGE q` �1 DEVELOPMENT SERVICES DEPARTMENT i,�P •" ,8� , 4700 BRAGAW STREET ANCHORAGE, AK 99519-6650 SOILS LOG - PERCOLATION TEST / . • ,,, Ben •n Schiller LEGAL DESCRIPTION: LOT I, BLOCK 2, RIVER PARK VIEW Sue. , + cis'. Ja 12017 '•�\'���� IIF�FD a r PERFORMED FOR: TROY DAVIS HOMFS \\\\N PROFESS10N�~ DATE: 5/19/16 PROJECT No.: PARCEL ID#: TECHNICIAN: W. ROBERTS Professional Engineers Stamp: DEPTH TEST HOLE 7 (feet) 1 OB/OG SLOPE SITE PLAN ° 2 3 4 ° 4 5 Q SEE SITE PLAN �, ° 6 7 0 . ' e 8 • . • • SILTY GRAVEL WITH SAND 9 o° a GM/GW 10 • C WAS GROUND WATER ENCOUNTERED? NO IFYES(�WHATDEPTH' S DEPTH OF WATER AFTER MONITORING: NONE b 11 ° DATE OF MONITORING: 5/29/16 p • 12 ••� GROSS TIME NET TIME DEPTH TO NET DROP 13— . •° DATE READING (MINUTES) (MINUTES) WATERNET (INCHES) (I 14 .4 . • TEST HOLE PRESOAKED PRIOR TO TESTING: 15 • 5/29 1 8:06/8:16 10 I.00"/5.00" 4.00" 2 8:17/8:27 10 0.88"/4.88" 4.00" 16 3 8:28/8:38 10 1.00"/5.00" 4.00" 17 ••• C BOH @ 17' 4 8:39/8:49 10 0.75"/4.75" 4.00" 18 5 8:50/9:00 10 1.00"/5.00° 4.00" 19 6 9:01/9:11 10 0.75"/4.75" 4.00" 20 PERCOLATION RATE:2•5 (MIN/INCH) PERC. HOLE DIA. 6" (INCHES) TEST RUN BETWEEN: 4 FT. and 5 FT. COMMENTS: TEST HOLE PRE SOAKED PRIOR TO TEST. TEST PERFORMED BY ANDERSON ENGINEERING. I,MICHAEL E. ANDERSON CERTIFY THAT THIS WAS PERFORMED IN ACCORDANCE WITH ALL STATE AND MUNICIPLE GUIDELINES IN EFFECT ON THIS DATE: 6/13/16 MUNICIPALITY OF ANCHORAGE DEVELOPMENT SERVICES DEPARTMENT g�P�•v• ` .. 'F,9++ 4700 BRAGAW STREET ANCHORAGE, AK 99519-6650 /Lb; � *�� SOILS LOG - PERCOLATION TEST - 5: .... Bea n Schiller : / LEGAL DESCRIPTION: LOT I, BLOCK 2, RIVER PARK VIEW SUB. ++��''. Jan 17.12592 •. • PERFORMED FOR: TROY DAVIS HOMES Nk\ PROFESSIONP� DATE: 5/19/16 PROJECT No.: PARCEL ID#: TECHNICIAN: W. ROBERTS Professional Engineers Stamp: DEPTH TEST HOLE 8 (feet) OB/OG SLOPE SITE PLAN 1 . 2 a 4 5 C SEE SITE PLAN . Q 6 4 . 7 a a 8 • . ' • SILTY GRAVEL WITH SAND 9 04 :a GM/GW 10 c WAS GROUND WATER ENCOUNTERED? No IF YES @ WHAT DEPTH'' DEPTH OF WATER AFTER MONITORING: NONE O 11 G DATE OF MONITORING: 5/29/16 E • 12 .a •t GROSS TIME NET TIME DEPTH TO NET DROP 13 DATE READING (MINUTES) (MINUTES) WATER (INCHES) (INCHES) 14 :1 TEST HOLE PRESOAKED PRIOR TO TESTING: 15 • ' 5/29 1 8:06/8:16 10 1.38°/5.13" 3.75" 2 8:17/8:27 10 1.50°/5.25" 3.75" 16 • ' 3 8:28/8:38 10 1.25°/5.00° 3.75" 17 � BOH@17.5 a 4 8:39/8:49 10 1.25"/5.00" 3.75" 18 5 8:50/9:00 10 1.50"/5.25" 3.75" 19 6 9:01/9:11 10 1.25°/5.00° 3.75" 20 PERCOLATION RATE:2•7 (MIN/INCH) PERC.HOLE DIA. 6++ (INCHES) TEST RUN BETWEEN: 4 FT. and 5 FT. COMMENTS: TEST HOLE PRE SOAKED PRIOR TO TEST. TEST PERFORMED BY ANDERSON ENGINEERING. I,MICHAEL E. ANDERSON CERTIFY THAT THIS WAS PERFORMED IN ACCORDANCE WITH ALL STATE AND MUNICIPLE GUIDELINES IN EFFECT ON THIS DATE: 6/13/16 MUNICIPALITY OF ANCHORAGE \` DEVELOPMENT SERVICES DEPARTMENT P •" 41441 4700 BRAGAW STREET ANCHORAGE, AK 99519-6650 • ��� •':� �/ • SOILS LOG - PERCOLATION TEST , ;•• • / Be in Schiller LEGAL DESCRIPTION: LOT 2, BLOCK 2, RIVER PARK VIEW SUB. TV's... A�L1p592SA/ ' PERFORMED FOR: TROY DAVIS HOMES IV`\F�FPROFESSIONP�\\"`°- DATE: 5/19/16 PROJECT No.: PARCEL ID#: TECHNICIAN: VV. ROBERTS Professional Engineers Stamp: DEPTH TEST HOLE 9 (feet) OB/OG SLOPE SITE PLAN 1 2 3 a 4 5 SEE SITE PLAN • 4 6 4 • 7 4 . a 8 • SILTY GRAVEL WITH SAND 9 -4 :d GM/GW 10 ° WAS GROUND WATER ENCOUNTERED? NO IF YES L WHAT DEPTH') DEPTH OF WATER AFTER MONITORING: NONE 11 C DATE OF MONITORING:• 5/29/16 12 DATE READING GROSS TIME NET TIME WATER o NET DROP 13 . (MINUTES) (MINUTES) (INCHES) (INCHES) • 14 .° . TEST HOLE PRESOAKED PRIOR TO TESTING: 15 • • 5/29 1 9:15/9:25 10 0.50°/4.00° 3.50" 2 9:26/9:36 10 0.75"/4.25" 3.50" 16 3 9:37/9:47 10 0.50"/4.00" 3.50" 17 °a BOH @ 17.5 4 9:48/9:58 10 0.63"/4.13" 3.50" 18 5 9:59/10:09 10 0.50°/4.00° 3.50" 19 6 10:10/10:2C 10 0.63"/4.13" 3.50" 20 PERCOLATION RATE:2•7 (MIN/INCH) PERC. HOLE DIA. 6" (INCHES) TEST RUN BETWEEN: 4 FT. and 5 FT. COMMENTS: TEST HOLE PRE SOAKED PRIOR TO TEST. TEST PERFORMED BY ANDERSON ENGINEERING. I,MICHAEL E.ANDERSON CERTIFY THAT THIS WAS PERFORMED IN ACCORDANCE WITH ALL STATE AND MUNICIPLE GUIDELINES IN EFFECT ON THIS DATE: 6/13/16 MUNICIPALITY OF ANCHORAGE DEVELOPMENT SERVICES DEPARTMENT 4700 BRAGAW STREET ANCHORAGE, AK 99519-6650 SOILS LOG - PERCOLATION TEST 0 . Bej in Schiller Ole••, A L 12592 •c�/ LEGAL DESCRIPTION: LOT 2, BLOCK 2, RIVER PARK VIEW SUB. � f•.. n,;120. •'��� PERFORMED FOR: TROY DAVIS HOMES NkV PROFESSIONP` DATE: 5/19/16 PROJECT No.: \\\\� PARCEL ID#: TECHNICIAN: VV. ROBERTS Professional Engineers Stamp: DEPTH TEST HOLE 10 (feet) OB/OG SLOPE SITE PLAN 1 2 3 4 5 SEE SITE PLAN a 6 4 • 7 a . C 8 • . • • SILTY GRAVEL WITH SAND 9 -a a GM/GW 10 c WAS GROUND WATER ENCOUNTERED? NO IF YES L WHAT DEPTH'1 DEPTH OF WATER AFTER MONITORING: NONE 11 DATE OF MONITORING: 5/29/16 . G •12 4 DATE READING GROSS ESENET M NTS) DEPTH To WATER N13— . • MMIUE (INCHES)INCE • 14 .4 . TEST HOLE PRESOAKED PRIOR TO TESTING: • 15 • 5/29 1 10:42/10:52 10 0.38"/3.63" 3.25" 2 10:53/11:03 10 0.50"/3.75" 3.25" 16 3 11:04/11:14 10 0.38"/3.63" 3.25" 17 ••• a BOH @ 17.0 4 11:15/11:25 10 0.50"/3.75" 3.25" 18 5 11:26/11:36 10 0.50"/3.75" 3.25" 19 6 11:37/11:47 10 0.63"/3.88" 3.25" 20 PERCOLATION RATE: 3.1 (MIN/INCH) PERC.HOLE DIA. 6" (INCHES) TEST RUN BETWEEN: 4 FT. and 5 FT. COMMENTS: TEST HOLE PRE SOAKED PRIOR TO TEST. TEST PERFORMED BY ANDERSON ENGINEERING. I,MICHAEL E. ANDERSON CERTIFY THAT THIS WAS PERFORMED IN ACCORDANCE WITH ALL STATE AND MUNICIPLE GUIDELINES IN EFFECT ON THIS DATE: 6/13/16 MUNICIPALITY OF ANCHORAGE " �\\, \\\\ DEVELOPMENT SERVICES DEPARTMENT 41::** i P •' "'irs� � � lei 4700 BRAGAW STREET ANCHORAGE, AK 99519-6650 1• %*? /*.•gg7H �\ SOILS LOG - PERCOLATION TEST %Fr; 4$, .? • • Benj. in Schiller . + Fc• AEL 12592 '�`�� LEGAL DESCRIPTION: LOT 3, BLOCK 2, RIVER PARK VIEW SUB. �11iF�FppROFESSIOHP� PERFORMED FOR: TROY DAVIS HOMFS \\\\\"�� DATE: 5/19/16 PROJECT No.: PARCEL ID#: TECHNICIAN: W. ROBERTS Professional Engineers Stamp: DEPTH TEST HOLE 11 (feet) 1 OB/OG SLOPE SITE PLAN c 2 3 ° 4 • 5 SEE SITE PLAN • 4 . 6 4 • 7 G 8 • . • • SILTY GRAVEL WITH SAND 9 Oa ' ° GM/GW 10 C WAS GROUND WATER ENCOUNTERED? NO IF YES @ WHAT DEPTH'' S DEPTH OF WATER AFTER MONITORING: NONE 11 G DATE OF MONITORING: 5/29116 •12 GROSS TIME NET TIME DEPTH TO NET DROP 13 d DATE READING (MINUTES) (MINUTES) WATER (INCHES) (INCHES) • 14 •` . • TEST HOLE PRESOAKED PRIOR TO TESTING: • 15 • 5/29 1 12:08/12:18 10 0.7573.50" 2.75" 2 12:19/12:29 10 0.63"/3.38" 2.75" 16 3 12:30/12:40 10 0.75"/3.50" 2.75" 17 . ° 4 12:41/12:51 10 0.50"/3.25" 2.75" 18 • - BOH @18.0 5 12:52/1:02 10 0.75"/3.50" 2.75u 19 6 1:03/1:04 10 0.50/3.25" 2.75" 20 PERCOLATION RATE: 3.6 (MIN/INCH) PERC. HOLE DIA. 6" (INCHES) TEST RUN BETWEEN: 4 FT. and 5 FT. COMMENTS: TEST HOLE PRE SOAKED PRIOR TO TEST. TEST PERFORMED BY ANDERSON ENGINEERING. I,MICHAEL E. ANDERSON CERTIFY THAT THIS WAS PERFORMED IN ACCORDANCE WITH ALL STATE AND MUNICIPLE GUIDELINES IN EFFECT ON THIS DATE: 6/13/16 MUNICIPALITY OF ANCHORAGE � _ ,, DEVELOPMENT SERVICES DEPARTMENT i P_.,. "isl�l� 4700 BRAGAW STREET ANCHORAGE, AK 99519-6650 • % e}gTM ' *j�� SOILS LOG - PERCOLATION TEST % ,,, • 0• , , Be �j in Schiller LEGAL DESCRIPTION: LOT 3, BLOCK 2, RIVER PARK VIEW SUB. rl$,6,p;0•p,.n.7 o59�A`��v PERFORMED FOR: TROY DAVIS HOMES , i‘\ Z\" DATE: 5/19/16 PROJECT No.: PARCEL ID#: TECHNICIAN: W. ROBERTS Professional Engineers Stamp: DEPTH TEST HOLE 12 (feet) OB/OG SLOPE SITE PLAN 1 d 2 3 4 4 5 ° SEE SITE PLAN Li 4 6 . 4 '. 7 a . 8 • . • • SILTY GRAVEL WITH SAND 9 °d I 1 GM/GW 10 ° WAS GROUND WATER ENCOUNTERED? NO IF YES Ca WHAT DEPTH" tS DEPTH OF WATER AFTER MONITORING: NONE lU= 11 G • DATE OF MONITORING: 5/29/16 E 12 • .° t GROSS TIME NET TIME DEPTH TO NET DROP 13— . • DATE READING (MINUTES) (MINUTES) WATER INCHES) (INCHES) 14 .° TEST HOLE PRESOAKED PRIOR TO TESTING: 15 • • 5/29 1 1:22/1:32 10 1.00"/4.00° 3.00" 4 2 1:33/1:43 10 1.13"/4.13" 3.00" 16 3 1:44/1:54 10 1.00°/4.00" 3.00" 17 4 41:55/2:05 10 1.13"/4.13" 3.00" 18 BOH @ 17.0 5 2:06/2:16 10 0.75"13.75" 3.00" 19 6 2:17/2:27 10 1.00"/4.00" 3.00" 20 PERCOLATION RATE: 3.3 (MIN/INCH) PERC. HOLE DIA. 6" (INCHES) TEST RUN BETWEEN: 4 FT. and 5 FT. COMMENTS: TEST HOLE PRE SOAKED PRIOR TO TEST. TEST PERFORMED BY ANDERSON ENGINEERING. I,MICHAEL E. ANDERSON CERTIFY THAT THIS WAS PERFORMED IN ACCORDANCE WITH ALL STATE AND MUNICIPLE GUIDELINES IN EFFECT ON THIS DATE: 6/13/16 MUNICIPALITY OF ANCHORAGE \ DEVELOPMENT SERVICES DEPARTMENT � ` ,!04!ih 4700 BRAGAW STREET ANCHORAGE, AK 99519-6650 ,*76 SOILS LOG - PERCOLATION TEST . ••• j Benj Schiller •• F , AEL 259 LEGAL DESCRIPTION: LOT 4, BLOCK 2, RIVER PARK VIEW SUB. 16,0FpAEL 1 1 2 2 PERFORMED FOR: TROY DAVIS HOMFS \\\ESSIONP DATE: 5/19/16 PROJECT No.: PARCEL ID#: TECHNICIAN: W. ROBERTS Professional Engineers Stamp: DEPTH TEST HOLE 13 (feet) OB/OG SLOPE SITE PLAN 1 . 4 2 3 4 5 • SEE SITE PLAN 4 6 • 4 .. • 7 ° . ° 8 . • SILTY GRAVEL WITH SAND 9 -44 4 GM/GW WAS GROUND WATER ENCOUNTERED? No I 0 IF YES L WHAT DEPTH'' DEPTH OF WATER AFTER MONITORING: NONE 11 ° DATE OF MONITORING: 5/29/16 •12 GROSS TIME NET TIME DEPTH TO NET DROP 13 DATE READING (MINUTES) (MINUTES) LACHES (INCHES) 14 TEST HOLE PRESOAKED PRIOR TO TESTING: 15 5/29 1 2:51/3:01 10 0.88"/4.00° 3.12" 4 2 3:02/3:12 10 1.00^/4.13" 3.13" 16 3 3:13/3:23 10 0.75"/3.88" 3.13" 17 4 43:24/3:34 10 1.00"/4.13" 3.13" 18 BOH @ 18.0 5 3:35/3:45 10 0.75"/3.88" tt 3.13 19 6 3:46/3:56 10 1.00"/4.13" 3.13" 20 PERCOLATION RATE: 3.2 (MIN/INCH) PERC. HOLE DIA. 6" (INCHES) TEST RUN BETWEEN: 4 FT. and 5 FT. COMMENTS: TEST HOLE PRE SOAKED PRIOR TO TEST. TEST PERFORMED BY ANDERSON ENGINEERING. I,MICHAEL E. ANDERSON CERTIFY THAT THIS WAS PERFORMED IN ACCORDANCE WITH ALL STATE AND MUNICIPLE GUIDELINES IN EFFECT ON THIS DATE: 6/13/16 MUNICIPALITY OF ANCHORAGE DEVELOPMENT SERVICES DEPARTMENT ,�Q,.,.• 4700 BRAGAW STREET ANCHORAGE, AK 99519-6650 *;49TM 'vitt y, � SOILS LOG - PERCOLATION TEST ;►• ,r .. Be Schiller : II h f's.• •• �a ,12592 •• ``i�/ LEGAL DESCRIPTION: LOT 4, BLOCK 2, RIVER PARK VIEW SUB. , �lF'••:,12592 PERFORMED FOR: TROY DAVIS HOMES IkkZrw �"`.\�+� DATE: 5/19/16 PROJECTNo.: PARCEL ID#: TECHNICIAN: W. ROBERTS Professional Engineers Stamp: DEPTH TEST HOLE 14 (feet) 1 OB/OG SLOPE SITE PLAN e 2 3 a• 4 • 5 SEE SITE PLAN • 4 6 4 . 7 4 . a 8 . ' • SILTY GRAVEL WITH SAND 9 cn GM/GW 10 c WAS GROUND WATER ENCOUNTERED? No IF YES(i%WHAT DEPTH'' S DEPTH OF WATER AFTER MONITORING: NONE E 11 G DATE OF MONITORING: 5/29/16 • 12 • 4 GROSS TIME NET TIME DEPTH To NET DROP 13 DATE READING (MINUTES) (MINUTES) WATER (INCHES) (INCHES) 14 TEST HOLE PRESOAKED PRIOR TO TESTING: • 15 • ' 5/29 1 4:11/4:21 10 0.75"/4.75" 4.00" 4 2 4:22/4:32 10 0.88"/4.88" 4.00" 16 3 4:33/4:43 10 0.75"/4.75" 4.00" 17 a ' G 4 4:44/4:54 10 0.63"/4.63" 4.00" 18 BOH @ 18.0 5 4:55/5:05 10 1.60"/4.63" 4.00" 19 6 5:06/5:16 10 0.88"/4.88" 4.00" 20 PERCOLATION RATE: 2.5 (MIN/INCH) PERC. HOLE DIA. 6" (INCHES) TEST RUN BETWEEN: 4 FT. and 5 FT. COMMENTS: TEST HOLE PRE SOAKED PRIOR TO TEST. TEST PERFORMED BY ANDERSON ENGINEERING. I,MICHAEL E. ANDERSON CERTIFY THAT THIS WAS PERFORMED IN ACCORDANCE WITH ALL STATE AND MUNICIPLE GUIDELINES IN EFFECT ON THIS DATE: 6/13/16 J. A. MUNTER CONSULTING, INC. February 21,2017 Mr. Kourosh Partow Project Manager Troy Davis Homes 165 E. Parks Highway, Suite 200 Wasilla AK 99654 Re: Evaluation of aquifers at the proposed Riverpark View Estates Subdivision,Eagle River Valley, Anchorage,Alaska. Dear Mr. Partow: This letter report is to provide the findings of an evaluation of aquifers near the proposed Riverpark View Estates Subdivision. The purpose of the evaluation is to determine if there is enough water to support on-site wells and to determine whether any surrounding well owners would be adversely affected. HYDROGEOLOGIC SETTING The proposed Riverpark View Estates Subdivision is located on the flank of the Eagle River Valley approximately six miles up-valley from the Glenn Highway crossing of the Eagle River. A geologic map of the area by Yehle and Schmoll (1987) shows that surficial geologic deposits consist of colluvium derived from glacial moraine deposits and glacial-lake deposits. Bedrock in the vicinity of the site is comprised mostly of a deformed metaclastic sequence (siltstone,graywacke,arkose,conglomeratic sandstone)that is chaotically juxtaposed with a metavolcanic sequence(greenstones, metachert,cherty argillite, argillite) (Munter and Allely, 1993). Bedrock is close to the land surface in the steep valley walls north and northeast of the site,but can be quite deep in the valley. A well located less than one mile south of the site in the valley bottom area is reported to have encountered bedrock at an elevation of 436 feet below sea level(Munter and Allely, 1993). A well located a few hundred feet northeast of the proposed subdivision encountered bedrock at a depth of 113 feet below land surface. Other than bedrock,potential aquifers in the area consist of buried glacioalluvial deposits or buried alluvial fans beneath the siltier glacial moraines, colluvium, and lake-bed deposits. METHODS AND SOURCES OF DATA This report provides a vicinity analysis that includes an evaluation of well data from surrounding properties to evaluate the general conditions in the area. Groundwater recharge information is reviewed to estimate potential sustainable aquifer yields. Test well drilling and aquifer testing was conducted to determine the properties of aquifers present at the site. Aquifer test data were analyzed using software by AQTESOLV pro 4.0. The aquifer characteristics are used to model 5701 PENNY CIRCLE,ANCHORAGE,AK,99516 jamunter@a,arctic.net PHONE(907)345-0165; FAx(907)348-8592 J. A. MUNTER CONSULTING, INC. expected responses in wells from the proposed new pumping. The model results are used to assess the water-supply potential at the proposed Riverpark View Estates Subdivision and the potential impacts of the development on surrounding properties. VICINITY ANALYSIS Aquifer Recharge and Water-Supply Potential Munter and Allely(1993)report that annual average precipitation at the nearest long-term weather station to the Eagle River area is 15.2 inches per year. A conservative estimate is that groundwater recharge at Riverpark View Estates averages approximately 20 percent of average annual precipitation, or about 3 inches per year. This translates to an average of approximately 350 gallons per day being recharged on each of the seven planned lots on the parcel. This amount of water is comparable to the Municipal requirement of 450 gpd for a 3-bedroom home. In addition to direct recharge of water onto lots, however,this subdivision also receives groundwater inflow from upgradient areas to the north and northeast along the flanks of the Eagle River valley. These data suggest that the potential supply of water is sufficient to sustain aquifers with the quantity of water needed for use by well owners in the subdivision and surrounding developments. Review of Area Well Records The MOA's On-site files were searched for records from adjacent properties (http://onsite.ci.anchorage.ak.us/WebLinkBrowse.aspx?startid=1). Logs of wells serving six nearby residential properties were found and are shown in Table 1. Table 1. Summary of data for wells near Riverpark View Estates Subdivision. Location Reported Reported well yield Estimated Aquifer Static water level Well or flow rate and transmis- type in feet below land depth year of sivity surface and year of (feet) measurement(gpm) (112/day) measurement Charlice 340 10 1977 10 Bedrock 84 1977 Subd. Tract 1.89 2015 2.1 100 2015 B-1 Thomson 113 50 1982 136 Sand and 15 1982 Subd., L1 6.9 1989 NM Gravel 18 1989 6 1994 NM 11.5 1994 Thomson 121 25 1982 69 Sand and 24 1982 Subd., L2 4.0+ 1988 NM Gravel 27 1988 6.5 1990 NM 27 1990 4.7 2005 NM 30 2005 7 2011 NM 36 2011 Thomson 101 50 1990 176 Sand and 25 1990 Subd.,L7 6+ 1994 NM Gravel 32 1994 6.1 2004 NM 42 2004 7.5 2008 NM 37 2008 7.75 2012 NM 30 2012 Evaluation of aquifers at Page 2 of 7 February 21,2017 Riverpark View Estates Subdivision,Anchorage,Alaska J. A. M UNTER CONSULTING, INC. Location Reported Reported well yield Estimated Aquifer Static water level Well or flow rate and transmis- type in feet below land depth year of sivity surface and year of Meet) measurement(gpm) (ft2/day) measurement Thomson 81 25 1982 129 Sand and 29 1982 Subd., L6 5+ 1997 NM Gravel 36 1997 Riverpark 148 15 2017 27 Gravel Flowing 2017 View Estates artesian Subd. B1, L1 Note 1: Estimated transmissivity(T)in ft2/day calculated by T=SC x 2000/7.48 where SC(specific capacity)=yield(in gpm)/drawdown(in ft). Full drawdown is assumed where data were lacking, resulting in conservative(i.e. low)estimates of T. Note 2:NM means not meaningful because flow rates reported are the typically the flow rate of the pump installed in the well and drawdown data were not reported. Summary of Well Record Review Five of the six wells with logs in the vicinity were found to tap non-lithified sand and gravel aquifers and one well tapped a bedrock aquifer. Non-lithified aquifers. Reported yields of wells tapping sand and gravel aquifers range from 15 to 50 gpm. The median reported well yield is 25 gpm. This is approximately 50 times the minimum required yield(0.52 gpm)needed for a five-bedroom home using the Municipality criterion of 150 gpd/bedroom. Reported static water levels range in depth from flowing artesian to 42 feet below land surface. Well depths range from 81 feet to 148 feet below land surface,with a median well depth of 113 feet. Calculated transmissivity values range from 27 to 176 ft2/day. The median estimated value of transmissivity is 129 ft2/day. This value is in the mid-range for a glacial sand and gravel aquifer of approximately 10-foot thickness(Freeze and Cherry, 1979,p. 29). The well data provided above shows that wells tapping nonlithified aquifers in the near vicinity of Riverpark View Estates Subdivision appear to be capable of supplying sufficient water to single family homes. Bedrock aquifer. The one well tapping a bedrock aquifer in the area reportedly encountered the top of the bedrock surface at a depth of 113 feet and was drilled to a depth of 340 ft,reportedly yielding 10 gpm when drilled. A subsequent inspection reported the yield at 1.89 gpm,which is more typical for a bedrock well,but still more than adequate for a typical home. Summary of Vicinity Analysis An analysis of potential aquifer recharge data suggests that the aquifers in the area have the potential to supply the water required for sustainable on-site use for the proposed Riverpark View Estates Subdivision. Evaluation of aquifers at Page 3 of 7 February 21,2017 Riverpark View Estates Subdivision,Anchorage,Alaska J. A. MUNTER CONSULTING, INC. The proposed subdivision is located in an area where wells mostly tap sand and gravel aquifers. The lone bedrock well in the vicinity is located further upslope or at a higher elevation from where all other wells for Riverpark View Estates Subdivision would be drilled,and new wells are unlikely to be drilled deep enough to tap into the bedrock aquifer. Examination of the well logs show that most wells penetrated coarse alluvial material -mostly sand and gravel -which is interpreted to be deposits either of a buried alluvial fan or glaciofluvial alluvium. wells in Table 1 penetrate through silty glacial deposits interpreted to be silty moraine-type deposits mapped by Yehle and Schmoll (1988)before penetrating a confined sand and gravel aquifer within or beneath the moraine-type deposits. Thus,two aquifers are identified in this area: 1) a confined aquifer within or beneath glacial moraine-type deposits; and 2)a bedrock aquifer. All aquifers appear to be capable of providing sufficient water for single-family domestic usage. SITE EVALUATION Test-Well Drilling Three test wells were drilled at the locations shown on the attached Well and Septic System Plan. Logs of the wells are provided in the Attachments. For this report,the well drilled in Block 2 on Lot 2 (121 ft deep)will be called Well 2,the well drilled on Lot 3 (128 ft deep) will be called Well 3,and the well drilled on Lot 4 (121 ft deep) will be called Well 4. All wells appear to tap the same confined sand and gravel aquifer in a depth range of approximately 110 to 130 feet below ground surface. Aquifer Testing Well 3 was pumped for four hours on February 10, 2017,while water levels were measured in the pumped well and in Well 2 and Well 4. Recovery measurements were also obtained in all three wells. Dataloggers were installed in Wells 2 and 4 and data were verified with manual readings. These data were used for the aquifer analysis summaries(attached). Data sheets and analysis summaries for all three wells are attached and the results are described below. Well 3. The well production rate varied from 15 to 28.8 gpm(the maximum production capacity of the pump),exhibiting a maximum of 37.6 feet of drawdown. The aquifer transmissivity was estimated to be 700 ft2/day(see attachment),which is above the range of transmissivities estimated from surrounding well log data(Table 1). Well 2. This well exhibited a maximum of 2.04 feet of drawdown during the test and the data were suitable for analysis using the method of Theis(1935). The aquifer transmissivity was calculated to be 1660 ft2/day (see attachment), which is also above the median transmissivity destimated from surrounding well log data(Table 1). Storativity was calculated to be 2.5 x 10"5, which is characteristic of a confined aquifer. Well 4. This well exhibited a maximum of 1.28 feet of drawdown during the test and the data were suitable for analysis using the method of Theis(1935). The aquifer transmissivity was calculated to be 1480 ft2/day (see attachment),which is also above the median transmissivity Evaluation of aquifers at Page 4 of 7 February 21,2017 Riverpark View Estates Subdivision,Anchorage,Alaska J. A. MUNTER CONSULTING, INC. determined from surrounding well log data(Table 1). Storativity was calculated to be 6.9 x 104, which is characteristic of a confined aquifer. Summary of aquifer testing analysis. The aquifer testing confirmed the geological analysis that all three wells tap the same confined sand and gravel aquifer at the site. The aquifer is relatively productive compared to many sand and gravel aquifers in glacial deposits. Although the estimated thickness of the aquifer is estimated to be on the order of 10 or more feet,the bottom of the aquifer was not penetrated and it could be thicker. The variability of transmissivities determined from the three wells and also compared to the values determined from surrounding wells(Table 1)is likely a result of aquifer heterogeneity and is within the range of variability expected from aquifers of this type. POTENTIAL EFFECTS OF NEW PUMPING Sand and Gravel Aquifer An analysis of the effects of pumping new wells both on future neighboring wells within Riverpark View Estates Subdivision and also on surrounding wells is described below using the method of Theis(1935). The Theis(1935)method requires certain simplifying assumptions. It is assumed that the aquifers are infmite in lateral extent without boundary conditions, are homogeneous and isotropic, and that recharge does not occur within the simulation time period. While these assumptions are simplifications of actual aquifer conditions,the Theis(1935)model is widely used and can provide an initial assessment of the magnitude of the likely effects of pumping on nearby wells. The setting of Riverpark View Estates Subdivision shows that no wells exist on the southwest side of the subdivision because of the presence of the Eagle River Greenbelt and Eagle River Road. Nearby residential wells are expected to be more than 100 feet distant from any wells in Riverpark View Estates Subdivision. This aquifer analysis assumes that all the wells for this analysis tap the same confined aquifer with a transmissivity of 700 ft2/day(the lowest of the three test well transmissivities) and a storativity of 6.9 x 104. Pumping is assumed to occur for 200 days,the approximate duration of wintertime conditions with no recharge. First, drawdown in a single pumping well is considered. Pumping for 200 days at a rate of 450 gpd,0.14 feet of drawdown is calculated at the pumping well. This is much less than the available drawdown in future wells. Also,the effects of this pumping on a neighboring well 100 feet away is calculated to be approximately 0.07 feet. Thus the effects of future Riverpark View Estates pumping on individual wells within the subdivision is concluded to be insignificant. Next,the neighborhood analysis was conducted by examining cumulative pumping from Riverpark View Estates. The average distance of wells at Riverpark View Estates is approximately 300 ft from the closest neighboring lot well sites. Pumping for 200 days at a total rate of 3150 gpd(450 gpd/lot times 7 lots), 0.4 feet of drawdown is calculated at a distance of 300 feet. Thus the project drawdown would be only a small portion Evaluation of aquifers at Page 5 of 7 February 21,2017 Riverpark View Estates Subdivision,Anchorage,Alaska J. A. MUNTER CONSULTING, INC. of the available drawdown in neighboring wells and it is concluded that the effects of the proposed pumping on nearby wells would be insignificant. Bedrock Aquifer Although not expected, one or more wells at Riverpark View Estates Subdivision may tap into the bedrock aquifer. Because there is only a single nearby well identified tapping this aquifer and it is several hundred feet away,the potential effects of this pumping are also expected to be negligible. Adequacy of Testing The aquifer testing described in this letter is less rigorous than that described by the Municipality of Anchorage recommended procedures for aquifer testing,however the testing and analysis provided in this report is considered adequate for the purposes of this report because: 1. The proposed new subdivision,at 7 lots, is barely over the criteria used for deciding whether aquifer testing is even needed: "...all proposed subdivisions with more than 5 lots to be served with on-site wells must have an aquifer test performed". https://www.muni.org/Departments/OCPD/development/onsite/Pages/SubdivisionInformation.aspx 2. During the aquifer testing performed,the maximum test pumping rate, at 28.8 gpm, was substantially higher than normal use of the wells. All three wells responded in the expected manner without anomalies and produced results suitable for analysis using the standard Theis (1935)method. 3. The analysis and aquifer testing performed has demonstrated the presence of a highly productive aquifer. The aquifer and recharge characteristics would not be expected to lead to water shortages for the intended uses. It is unlikely that further testing of the aquifer identified would result in significantly different results. SUMMARY AND CONCLUSIONS Most wells in the Riverpark View Estates Subdivision are likely to tap a sand and gravel aquifer between about 110 and 130 feet below ground surface. A few wells may tap a bedrock aquifer, although it is unlikely. Both aquifers,however,are considered adequate to provide sufficient water to meet MOA standards for new homes. Area-wide hydrogeology data show that the local hydrologic regime appears to be adequate to support new water demands from wells as proposed. The analysis of potential impacts to surrounding well owners shows that ample water is available to support on-site wells and that surrounding well owners or neighboring future homeowners within the proposed subdivision would not be adversely affected. The effects of the proposed new pumping are sufficiently small that further aquifer testing, analysis, and modeling of the potential effects of the new pumping is not warranted. Evaluation of aquifers at Page 6 of 7 February 21,2017 Riverpark View Estates Subdivision,Anchorage,Alaska J. A. MUNTER CONSULTING, INC. CLOSING Should you have any questions about this report,please call me at 345-0165 or 727-6310. Sincerely, J. A. Munter Consulting, Inc. l_a_AA,4-foi. m t6(^,d - James A. Munter,CPG, CGWP Principal Hydrogeologist Certified Ground Water Professional No. 119481 Alaska Licensed Professional Geologist No. 568 Attachments Well and Septic System Plan, Riverpark View Estates Subdivision Well logs(Wells 2, 3,and 4) Test pumping data(Well 3) Aquifer analyses(Wells 2, 3,and 4) References Cited Freeze R. A., and J. A. Cherry, 1979, Groundwater, Prentice Hall, Englewood Cliffs,NJ, 604 p. Munter, J.A., and Allely, R.D., 1993, Water-supply aquifers at Eagle River, Alaska: Alaska Division of Geological & Geophysical Surveys Professional Report 108, 20 p., 4 sheets, scale 1:12,000. Theis, C. V., 1935, The relation between the lowering of the piezometric surface and the rate and duration of discharge of a well using groundwater storage: Trans. Amer. Geophys. Union, 2,pp 519-524. Yehle, L. A, and H. R. Schmoll, 1988, Surficial geologic map of the Anchorage B-7 SE quadrangle,Alaska,U. S. Geological Survey Open-File Report 88-381. 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Y �\ jam. r '1:: ....- ' ---'s-'.4... - 1. ....--..'--4.'4 / -' *:11:11:::::‘).\,‘'(\s'•:: ::::‘ ` ‘4:-/1/4" 47.°4r:11 •••—• K•.--.1---.......:"----6•1_7------_, (1-3't• , -, is<...t. i----��.�_ '- '�, -.. �._tom �\� \\ \� \a\• `\ �:�`\``�. \ \'` ^--.�, `, '•`^\ \ \..��/-. /�\ \ \`. �'`^\�\---1�ti `` /:::•'I • ` ��- I i �- • �t\L �.� `\-`L - -�,_.� �__-.__ � \ • • ``• ` elf' ( 1 \ 1 �J / \ �..\1\ �` �.._.-. • \ r'\ . -,4,41f.. ---____...- \ ---,„1, , ----___A__ --' / - I '_.\ \ ,..�. •\ \\ \ \ \\ .,` - y \ �\•.\\ 4.•�. /•\/ `\ ` �\;\ . . /\`�\ \ \• 'moi \ } 4 • • `..\\\.\\• 1 \ \,\\`\`\,•.\� \� Jam\\\ \. `\�``'-`\ �\ ,/ \ `�� �I-•� � �`�� ��\\�s e \... .. -..:--'\'`.\ \ s, \•\ 40,_ ,\ \ \ \ \• \,-•••,----.,---_—__... \,----.```\�\;\�\ 1 _ \\•,, \:: .,\. \ `�, \ Y\ \ \\ \\\ , \ \ \ \\ . \ \ [ ` \ \ \\� PLAN VIEW SCALE: 1" = 50' GRADING PLAN LEGEND f, e PROPOSED WELL LOCATION a) TEST HOLE LOCATION r---' SEPTIC RESERVE AREA: 10,000 SF/PROPERTY EXISTING CONTOUR (1') CALL BEFORE YOU DIG VERIFY RECORD DRAWING Note: To be filled out on original drawings upon project completion. _N.NN\‘ _-- EXISTING CONTOUR (5') M SHALL IF ALL WA u .COMPANIES 1. DATA PROVIDED BY: 3.Bosed on periodic field observations by the �E.-F•ALASII - PROPOSED CONTOUR 1' PRIOR TO ILONENCENENT a EXCAVATION. NE Fouowmc SCALE �P•• 4-11 -- - ( ) ISA PARTS UST: This will serve to certify that these Record Engineer(or on individual under his/her direct y1; y/ PROPOSED CONTOUR (5') ALASKA DIG LINE - 811 THIS BAR REPRESENTS Drawings ore a true and occurote supervision), the Contractor-provided data / TTN ';t) RIVERPARK VIEW ESTATES SUBDIVSION TROY DAVIS HOMES,INC ANDERSON ENGINEERING /W;49- / repreaentotion of the project os constructed. appears to represent the project os constructed. / PROPOSED SPOT ELEVATION LOCATE CALL CENTER OF ALASKA 278-3121 ONE INCH ON ORIGINAL CONTRACTOR: 1115E PARKS HWY, STE 200 PO BOX 240773 DATA TRANSFER CHECKED BY: ANCHORAGE. AK 99554 ANCHORAGE, AK 99524 FUTURE DRAINAGE PATTERN (INCLUDES ACs.AWAu.CEA.ENC.BUTLER AvATTON/TESORO• DRAWING. BY: TITLE: 0', asyr,n„S*. / OD COLE.IAP.TRAFFIC SIGNALS.150*STORY/STREETS. COMPANY: 907-310-2501 907-522-7773 Of Vi.. CE 1159¢ • ice AND ALASKA neat STAR.) o'er t DATE: BY: TITLE: 1 E •..,,,,.••t<`_ SUBDIVISION WELL Sc SEPTIC PLAN II g p STATE STORM/STREET LIGHTS 333-2411 2. DATA TRANSFERRED BY: DATE: Il 4'D,tsa+l�r HOWZ SCALE:i''w50' IF BAR IS NOT ONE DATE:2-e-2017 IpOD: SW 1929 Cl / MILITARY PETROLEUM LINES 862-4112 INCH, ADJUST DRAWING COMPANY: VERT SCALE: r-to' v .\CALF.: 1" _ ;",u' SCALE ACCORDINGLY. DATE: OWNER CONSULTANT SEAL PLATTING CASE /S-12317 SHEET f 1 ` Wheaton Water Well, Inc. 1190 N. Wasilla-Fishhook Road Wasilla, AK 99654 (907)376-2041 WELL FLOW TEST Project: Troy Davis Homes, Inc. Date of Test: 2-10-2017 Well Site: River Park View, Lot 3 Block 2 Casing: 128' of 6" ID Steel Well Depth: 128 ft. Screen: None Static Water Level: 19 ft. Date Level Taken: 12-27-2016 Date Drilled: 12-27-2016 Drilled By: Wheaton Water Wells Elapsed Static Gallons Per Draw Down Draw Down Remarks Time Level Minute Lot 2 Lot 4 0 18.0 0 26.57' 10.06' Start Pumping 1:18 32.6' 20 2 35.2' 15 3 35.8' 15 4 35.9' 15 5 36.0' 15 6 36.1' 15 7 36.25' 15 8 36.3' 15 9 36.4' 15 10 36.4' 15 15 41.8' 20 27.4' @ 18 min. 10.2' @ 17 min. 20 43.3' 20 25 48.2' 24.5 30 47.3' 23.5 27.9' @ 33 min. 10.7' @ 32 min. 34 55.2' 28.8 60 55.2' 28.8 28.3' @ 63 min. 10.9' @ 62 min. 90 55.3' 28.8 28.4' @ 93 min. 11.1' @ 92 min. 120 55.4' 28.8 28.5' @ 123 min. 11.2' @ 122 min. 150 55.5' 28.8 28.6' @ 153 min. 11.3' @ 152 min. 180 55.6' 28.8 28.6' @ 183 min. 11.3' @ 182 min. 210 55.5' 28.8 28.6' @ 213 min. 11.3' @ 212 min. 240 55.6' 28.8 28.6' @ 239 min. 11.3' @ 238 min. Stop Pumping Draw Down/Recovery Elapsed Time Static Level Elapsed Time Static Level Elapsed Time Static Level 1 41.2' 11 19.3' 25 18.7' 2 33.1' 12 19.2' 30 18.6' 3 27.9' 13 19.1' 4 24.7' 14 19.0' 5 22.7' 15 18.9' 6 21.4' 16 18.85' 7 20.6' 17 18.8' 8 20.1' 18 18.8' 9 19.7' 19 18.8' 10 19.4' 20 18.75' 100. _ I I I r I 11 [ 11 I I _ 9--_1g. o 0-o-Q-Q S Q- II--o--Q-Q.QQom.___-.. p P 10. - ti a = o e e o d t - - 0.1 - 1__L_l_I__ t � LJ i t ! t - I I II. 1. 10. 100. 1000. Time (min) AQUIFER TEST RESULTS Data Set: C:\...\well 3.agt Date: 02/15/17 Time: 06:05:02 PROJECT INFORMATION Company: Troy Davis Homes Client: Riverpark View Subdivision Location: Eagle River Valley Test Well: Lot 3 Test Date: 2/10/2017 WELL DATA Pumping_Wells Observation Wells Well Name I X(ft) ! Y(ft) ) WeII Name X(ft) Y(ft) Well 3 I 0 ; 0 a Well 3 0 0 SOLUTION Aquifer Model: Confined Solution Method: Theis T = 696.2 ft2/day S = 3.589E-23 Kz/Kr = 1. b = 10. ft 10. _ i I IIIIITI I I 1 1 11111 I I I I I i III I D - i dossaisagosol I 1 a • e n - t 0.1 — • t - - ❑ • 0.01 1 1 l u l l I I 1 { 1 1 1 1 1 I _.11 1 1 1 $ I t 11.1 I 1. 10. 100. 1000. 1.0E+4 Time (min) AQUIFER TEST RESULTS Data Set: Date: 02/15/17 Time: 05:58:25 PROJECT INFORMATION Company: Troy Davis Homes Client: Riverpark View Subdivision Location: Eagle River Valley Test Well: Well 3 Test Date: 2/10/2017 WELL DATA Pumping Wells Observation Wells Well Name X(ft) Y (ft) Well Name X (ft) Y(ft) , Well 3 I 0 0 0 Well 2 I 100 0 SOLUTION Aquifer Model: Confined Solution Method: Theis T = 1658.9 ft2/day S = 2.53E-5 Kz/Kr = 1. b = 10. ft 10. C I I Mil it f I I t l l III f---- l i I III I I III IIP • s _ ons - n a 0.1 = a e = = e - n =�� t 0.01 — f - 0.001 - 3 F 1.0E4 �.._---� fLi ,,' 1 !_.1 111111 _ I 111_111 1. 10. 100. 1000. 1.0E+4 Time (min) AQUIFER TEST RESULTS Data Set: C:\...\well 4.aqt Date: 02/15/17 Time: 06:01:28 PROJECT INFORMATION Company: Troy Davis Homes Client: Riverpark View Subdivision Location: Eagle River Valley Test Well: Lot 3 Test Date: 2/10/2017 WELL DATA Pumping Wells Observation Wells Well Name X(ft) Y(ft) IWell Nam_e X (ft)-_ Y(ft) Well 3 - 0 I 0 , 0 Well 4 0 100 SOLUTION Aquifer Model: Confined Solution Method: Theis T = 1480.7 ft2/day S = 0.0006939 Kz/Kr= 1. b = 10. ft