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Home My WebLink AboutBRANDT S12503Onsite File ------------ GARNESS ENGINEERING GROUP, Ltd -- v-. -.- *rw ENGINEERING,* SALES CONSULTING January 2, 2020 Municipality of Anchorage Development Service Department On -Site Water & Wastewater Program 4700 Elmore Road Anchorage, AK 99507 Ref: Soils Investigation Report and Septic Reserve Area for the Proposed Brandt Subdivision; Lot 1 and 2 in Anchorage, Alaska (A SUBDIVISION OF T12N R3W SECTION 22 LOT 43A) To whom it may concern: The reference property is located off Gamache Drive in Anchorage, Alaska. Based upon the preliminary plat drawing provided to us by Edge Survey and Design, LLC, T12N, R3W, Section 22, Lot 43A is to be subdivide into two lots, Brandt Subdivision, Lot 1 and 2. It should be noted that access to the proposed Brandt; Lot 2 will be accessed off of Totem Road, Anchorage, AK. The lot has an existing house located on it with a MOA approved well and septic system. We have excavated and logged four (4) testholes on the proposed Brandt; Lot 2. The testhole data has been used to establish a septic reserve area for the proposed subdivision. The proposed lot will be served by a private well and septic system. PROPOSED SEPTIC RESERVE AREAS Per MOA wastewater ordinance AMC 15.65.405 and 15.65.410, we are required to provide a site map showing a septic reserve area that meets the requirement set forth in Table 7 of 15.65.410 (see below): Table 7. Reserved Area Requirements Percolation Rate (minutes/inch) Reserved Area (square feet) '1-5 10,000 6 -12 12,000 13-24 14,000 25.60 16,000 Four (4) testhole were excated on proposed Brandt; Lot 2. As can be seen on the attached soils logs, Testhole #1 and Testhole #2 could not be perked due to water weeping in through the organics. However, the soils appeared visually permeable. A percolation test was performed on 3701 East Tudor Road, Suite 101 * Anchorage, Alaska 99507-1259 Phone: (907) 337-6179 * Fax: (907) 338-3246 * Website: www.garnessengineering.com Page 2 of 2 Testholes #3 and #4 and both perked at a rate between 1-5 minutes/inch. Therefore, per table 7 (listed above) a 10,000 ft2 septic reserve area is required. Attached is a site map which shows the septic reserve area for the proposed lot of 10,000+ ft2 (80 x 130 = 10,400 ft2). Per the recommendation of the field tech, a 0.8 application rating should be used for the design (visual determination). Therefore, we show a 12,000 ft2 reserve area to be conservative. There appears to be sufficient area for a structure, driveway and onsite wastewater disposal system and private well for the proposed lot. TOPOGRAPHY: As can be seen on the attached 100 scale, the topography information has been overlain. Per the GEG site visit and the attached topography drawing, there are slopes greater than 25% however, they are less than 46%. In short, given the fast percolation rate (5 min/inch) and low groundwater table (testholes dry), it is reasonable to believe that the drainfield would meet the MOA steep slopes provision. Due to his fact, a waiver will not be required, and topography appears to meet MOA requirements. WATER AVAILABILITY: Well flow and nitrate information were obtained from MOA records on the adjacent lots (attached). They are as follows: ® T1 2N RM Sections 22 Lot 43A — 18 gallons/minute with a total depth of 140 feet ® David Ring; Lot 1 — 3.2 gallons/minute with a total depth of 125 feet and nitrates of 0.141 mg/L ® David Ring; Lot 2B — 50 gallons/minute with a total depth of 137 ® David Ring; Lot 2A — 30 gallons/minute with a total depth of 140 ® Latta; Lot 4 — Nitrates were non-detectable 6/2/2015 — North of proposed subdivision ® Greenland; Block 3, Lot 3 — Nitrates at 1.85 mg/L — West of proposed subdivision Although there are limited nitrate samples in the vicinity of the proposed subdivision, it appears that elevated nitrates are not a concern. Well production will not be an issue for the proposed lot. If you have any questions, please contact us as at 337-6179. S. 3701 East Tudor Road, Suite 101 * Anchorage, Alaska 99507-1259 Phone: (907) 337-6179 * Fax: (907) 338-3246 * Website: www. garnessengineering.com . ❑ I TOPO CONTOUR LINES TESTHOLELOCATIONAREAPPROXIMATE;THEY WERE NOT SUREYED IN BUT ARE BASED UPON DAVID RING; LOT 1 ARE 5' AND APPROXIMATE FLAGGING OF THE LOT LINES IN THE FIELD 1 << R DIUS I EPTIC _ AREA I I\ VID RING; LOT 2B \ / \ \ T.H. T.H.#1 I EKVALL; $ TRACT B-1 I_1 0 I SEPTIC ✓ 150 EET RESERVEAREA / I\ 80 EE --I I/ E TING LOT LL O LO TO TH EASTD BRANCH ECOME "LOT 1 O PROPOSE OES OT NCRO H ON SUBDIVISION; LOT 2 / P OP SED L T T R3W SECTIO 2; LOT 46 WF�0-I/ I XMALINOI/S; 1"=100' i • 4t••'(, _.-------— ------ ----- —------------- j' GARNESS ENGINEERING GROUP, Ltd �. �� 49 i•• �. —_ --� ENGINEERING o SALES �, CONSULTING -� - -- 10 J s 3701 E. TUDOR ROAD, SUITE 101 -ANCHORAGE, AK 99507 -PHONE (907) 337-6179 -FAX (907) 338-3246-WEBSITE:w .gamessengineedng.com 0••••••• •J••.••••..•.•••...........0 PREPARED FOR: PHONE NUMBER: PAGE NUMBER: ,0 ••e A. Gamess I -Li , LARRY BRANDY 907-351-7957 1OF 2 �� J,'� • C - 53 :�AV Aw PROJECT/LEGAL DESCRIPTION: DRAWN BY: #♦�••. +� "�j•.` �� Tl 2N R3W SECTION 22 LOT 43A D.J.G. 1�Fp••''••• .... • ry��"�, �. TYPE OF WORK: DATE: LICENS 44FFe � OE SEPTIC SYSTEM DESIGN UPGRADE 1/2/2019 #AECC884 GA.RNESS, ENGINEERING GROUP, Ltd -.---- --- - aru �. i�wrtnvHu, auiie iui--hu--fu<—f-FHuNt(uuf)33/-El/Y-FA (uu/)339-3146-VVEBSITE�gameaaen9neeNng.mm SOIL LOG - PERCOLATION TEST LEGAL DESCRIPTION: Tl 2N R3W SECTION 22 LOT 43A PERFORMED FOR: LARRY BRANDT DEPTH (feet) ORG 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 914 DATE: 12/13/2019 • II�III�'I i//iI %/% 11NN • }1}2YY`Y`II DEPTH TO GROUNDWATER DATE DRY 12/13/2019 DRY 12/30/2019 MORA DEPTH TO GROUNDWATER DATE DRY 12/13/2019 DRY 12/30/2019 SITE PLAN 11 a11181 DATE READING CLOCK I NET TIME WATER LEVEL NET DROP TIME (MINUTES) READING (INCHES) A PERCOLATION TEST COULD NOT BE PERFORMED DUE TO RUNOFF AND/OR WEEPING FROM THE ORGANIC LAYER INTO THE PERCOLATION BENCHES - SOILS APPEARED PERMEABLE AND A PERCOLATION TEST COULD BE ATTEMPTED AT A LATER DATE 19 PERCOLATION RATE - (MIN./INCH) PERC. HOLE DIA. TEST RUN BETWEEN - FT. AND FT. 20 A FOUR HOUR PRESOAK WAS PERFORMED: ❑ YES E NO SOILS LOGGED BY: DAVID GARNESS PERCOLATION TEST PERFORMED BY: N/A COMMENTS: PERCOLATION READINGS ARE WITHIN 1/16 OF INCH. PERFORMED BY GEG, Ltd. I, JEFFREY A. GARNESS, CERTIFY THAT THIS WAS PERFOR ED IN ACCORDANCE WITH ALL STATE AND MUNICIPAL GUIDELINES IN EFFECT ON THIS DATE: ?� 3/ 6 (INCHES) GARNESS ENGINEERING GROUP, Ltd - ENGINEERING GALES > CONSULTING 3701 E. TUDOR ROAD, SUITE 101 'ANCHORAGE, AK 99507 -PHONE (907) 3376179 -FAX (907) 338-3246' WEBSITE: wvrw.gamessengineenng.com SOIL LOG - PERCOLATION TEST LEGAL DESCRIPTION: T12N R3W SECTION 22 LOT 43A PERFORMED FOR: DEPTH (feet) flE 1 ORG LARRY BRANDT 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 DATE: 12/13/2019 TEST HOLE #2 SOIL CLASSIFICATIONS •-e II�I'I�II i//iICL GC1111N OIL .. •YY,7ZY � MH �' SPCH ltY!`YY1iI ��yy�� Y�� • ML DEPTH TO DATE GROUNDWATER DRY 12/13/2019 I SITE PLAN ! Q �\ `VV �O G� �P 4,�CiP QN SCALE: 1°=100 DATE READING CLOCK NET TIME WATER LEVEL NET DROP TIME (MINUTES) READING (INCHES) A PERCOLATION TEST COULD NOT BE PERFORMED DUE TO RUNOFF AND/OR WEEPING FROM THE ORGANIC LAYER INTO THE PERCOLATION BENCHES - SOILS APPEARED PERMEABLE AND A PERCOLATION TEST COULD BE ATTEMPTED AT A LATER DATE 19. 111111111 PERCOLATION RATE (MIN./INCH) PERC. HOLE DIA. 6 (INCHES) B.O.H. TEST RUN BETWEEN FT. AND - FT. 20 A FOUR HOUR PRESOAK WAS PERFORMED: ❑ YES NO SOILS LOGGED BY: DAVID GARNESS PERCOLATION TEST PERFORMED BY: N/A COMMENTS: PERCOLATION READINGS ARE WITHIN 1/16 OF INCH; TESTHOLE WAS BACKFILLED AND NO LONGER VIABLE FOR GROUNDWATER MONITORING PERFORMED BY GEG, Ltd. I, JEFFREY A. GARNESS, CERTIFY THAT THIS WAS PERFORMED IN ACCORDANCE WITH ALL STATE AND MUNICIPAL GUIDELINES IN EFFECT ON THIS DATE: e rAV/I AF �7i1 \fit GARNESS ENGINEERING GROUP, Ltd —1 t. I U-11 HVAU. DUI It lUl ' ANUHUHAUt, A 95507' PHONE (50/) 337-6779' FAX(9W) 338-3246' WEBSITE v garne enginee6ng,c m SOIL LOG - PERCOLATION TEST LEGAL DESCRIPTION: T12N R3W SECTION 22 LOT 43A PERFORMED FOR: DEPTJf(feet)��1 ORG 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 LARRY BRANDT TEST HOLE #3 DATE: 12/20/2019 SOIL CLASSIFICATIONS CLOCK TIME .• WATER LEVEL READING GW 0. GP ML II�II','IGM i//iICL - //. NNN O IIIIIIIIIMH 01I �•' y� Y``YYYII P�yyp�iCH 3 Yy�OH - SC - SM TO ML DEPTH TO DATE GROUNDWATER DRY 12/20/2019 DRY 12/30/2019 SITE PLAN 'AD Pc' N SCALE: 1"=100' DATE READING CLOCK TIME NET TIME (MINUTES) WATER LEVEL READING NET DROP (INCHES) 12/20/2019 1 11:50 - 6" - 2 12:20 30 01I 6" 3 12:20 - 6" - 4 12:50 30 01I 6" 5 12:50 - 6" - 6 1:20 30 01I 6" 7 1:20 - 6" - 6 1:50 30 01I 6" 19 PERCOLATION RATE <5 (MIN./INCH) PERC. HOLE DIA. 6 (INCHES) TEST RUN BETWEEN 4.5 FT. AND 5.5 FT. 20 A FOUR HOUR PRESOAK WAS PERFORMED: ❑ YES NO SOILS LOGGED BY: JODY MADS PERCOLATION TEST PERFORMED BY: JODY MAUS COMMENTS: PERCOLATION READINGS ARE WITHIN 1/16 OF INCH. RECOMMEND SOIL APPLICATION RATE OF 0.8 GPD/FT2 PERFORMED BY GEG, Ltd. I, JEFFREY A. GARNESS, CERTIFY THAT THIS WAS PE !FOR DIED IN ACCORDANCE WITH ALL STATE AND MUNICIPAL GUIDELINES IN EFFECT ON THIS DATE: 2 5 vi it AF ��c GARNES S ENGINEERING GROUP, Ltd ENGINEERING -SA TING „vi �. ivwrtnv iie iUI'nn—"Writ,nn99>UI"YHQNt(9U/)331{1/9-FA (9UT)33&3246'WEBSITE:—.g—neng,,eenng.com SOIL LOG - PERCOLATION TEST LEGAL DESCRIPTION: T12N R3W SECTION 22 LOT 43A PERFORMED FOR: _ DEPTH LARRY BRANDT (feet) TEST HOLE #4 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 DATE: 12/20/2019 SM TO ML DEPTH TO DATE GROUNDWATER DRY 12/20/2019 DRY 12/30/2019 SITE PLAN Pc' P� C6 DATE READING SOIL CLASSIFICATIONS WATER LEVEL READING GW ORG �� •-:, W ORGANICS, STUMP, GP ML DEBRIS - AREA DISTURBED 2 G M GL 30 0" GC OL 3 SW MH - ORGANICS/LOAM �• °�° SP CH 12:51 30 SM ,' OH 6" 5 SC - SM TO ML DEPTH TO DATE GROUNDWATER DRY 12/20/2019 DRY 12/30/2019 SITE PLAN Pc' P� C6 DATE READING CLOCK TIME NET TIME (MINUTES) WATER LEVEL READING NET DROP (INCHES) 12/20/2019 1 11:51 - 6" - 2 12:21 30 0" 6" 3 12:21 - 6" - 4 12:51 30 0" 6" 5 12:51 - 6" - 6 1:21 30 0" 6" 7 1:21 - 6" - 6 1:51 30 0" 6" 19 B.O.H. PERCOLATION RATE <5 (MIN./INCH) PERC. HOLE DIA. 6 (INCHES) TEST RUN BETWEEN 6.5 FT. AND 7.5 FT. 20 A FOUR HOUR PRESOAK WAS PERFORMED: ❑ YES NO SOILS LOGGED BY: JODY MAUS PERCOLATION TEST PERFORMED BY: JODY MAUS COMMENTS: PERCOLATION READINGS ARE WITHIN 1/16 OF INCH. RECOMMEND SOIL APPLICATION RATE OF 0.8 GPD/FT2 PERFORMED BY GEG, Ltd. I, JEFFREY A. GARNESS, CERTIFY THAT THIS WAS PE ORf�ED IN ACCORDANCE WITH ALL STATE AND MUNICIPAL GUIDELINES IN EFFECT ON THIS DATE: / Z ; ///r