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Home My WebLink AboutSHANGRI-LA ESTATES-EAST PH 2 S12704Onsite File EsTaTes 411111111111111) Eu TRACT B SHANGRI-LA ESTATES EAST PHASE 2 SUBDIVISION SEPTIC ANALYSIS & WATER AVAILABILITY REPORT REV 1 Scott Grigsby 16050 Mountain Air Drive Anchorage, AK 99516 Prepared By: May 2023 Prepared By: Grant Mathews, P.E. May 2nd, 2023 Subject: Tract B Shangri-la Estates East Phase 2 Subdivision – Septic Analysis & Water Availability Report REV 1 Platting Case TBD Page 2 of 9 EXCELLENCE IN CIVIL ENGINEERING SINCE 1982 • SITE PLANNING • CIVIL ENGINEERING DESIGN • PROJECT MANAGEMENT Project Location The project site consists of an existing 17.5-acre parcel zoned R-7SL and identified as Tract B of Shangri-la Estates East. The parcel is located east of Mountain Air Drive in Anchorage, Alaska. The site is accessed via Goldenview Drive, to East 162nd Avenue, to Windsong Drive, to Sandpiper Drive, to Mountain Air Drive which terminates at the parcel’s northwest corner. The parcel north of the subject property is identified as Tract G-1 of Mountain Air Estates and is currently undeveloped. Property to the east is Tract A Burlwood Subdivision, also currently undeveloped. Property to the west, across Mountain Air Drive, is identified as Tract A of Shangri -la Estates East and is currently undeveloped. Properties to the south consist of residential development of generally 1-acre lots from the Shangri-la Estates East development along Mountain Air Drive and Sandpiper Drive. Existing Conditions & Land Cover The site is currently undeveloped and well vegetated with mature trees and brush. Topographically, the site drains in a south to north/northwest direction. Roughly 105 feet of relief occurs from the southeast corner to the northwest. Slopes within the parcel range from 12% along the south end to roughly 3 to 5% to the northwest. With the exception of a small, isolated bluff near the center of the site, no slopes within the parcel exceed 20%. The project resides within the Rabbit Creek watershed and contains two unnamed streams as previously identified by Watershed Management (WMS). A screenshot of the WMS drainage mapper illustrates the general watershed configuration. Wetlands were delineated within the project boundary by Travis/Peterson Environmental (TPECI) in the summer of 2022. The delineation identifies approximately 6.4-acres or 36.5% of the project site as wetlands which is consistent with the current GIS maps available from WMS. WMS Drainage Maps (8.29.22) N Project Site May 2nd, 2023 Subject: Tract B Shangri-la Estates East Phase 2 Subdivision – Septic Analysis & Water Availability Report REV 1 Platting Case TBD Page 3 of 9 EXCELLENCE IN CIVIL ENGINEERING SINCE 1982 • SITE PLANNING • CIVIL ENGINEERING DESIGN • PROJECT MANAGEMENT Proposed Development Plan The proposed development intends to subdivide and create eight residential lots and one tract from the 17.5- acre parcel. Each lot will be served by individual wells and onsite septic systems as no public water or sewer infrastructure exists within the area. The eight lots range in size from 40,000 to 41,800 square feet. The subdivision is configured such that the eight lots are located along the easterly side of the existing Mountain Air Drive. Access to each of the lots will be directly from Mountain Air Drive. The remaining Tract B-1 will be preserved as open space due primarily to the existing creek and large extent of wetlands located across the easterly portion of the tract. Existing grades are generally less than 20% across the site, and the 40,000 sf minimum lot size is sufficient to support on site systems. Testing Process Triad Engineering, LLC performed septic testing onsite on August 17th, 2022. Weather conditions were generally cloudy and damp with temperatures in the mid-50’s in the morning to mid-60’s in the afternoon. BTH Construction, LLC mobilized a 200 series excavator to the site and provided an operator for the geotechnical exploration. Lot lines were staked and flagged by The Boutet Company in advance of testing. Wetlands flagging remained in place to provide additional identification in case test holes needed to be field adjusted. Access for the excavator was such that minimal to no clearing was required for testing. Each test hole was advanced to a depth of roughly 10 feet below ground surface (BGS). Upon completion of each test hole, a 4” diameter perforated pipe was placed within the excavation and backfilled with the stockpiled soils. A bench was excavated adjacent to each test hole at an appropriate elevation so that percolation testing could be completed. A roughly six-inch-deep hole was hand dug into undisturbed soils using a shovel and approximately two inches of ¾” pea gravel was placed at the bottom of the hole. A four-inch diameter perforated PVC pipe was placed vertically into the test hole and the annulus backfilled with pea gravel. Water was then carefully poured into the pipe to a level approximately six inches above the bottom of the hole. Measurements were then taken at 10 or 30-minute intervals using a standard tape measure. The process was repeated for each test hole as necessary to meet Title 15 requirements. The initial 30-minute reading in all test holes exceeded ½” drop, so pre-soaking was not required. The investigation proceeded from south to north, with Lot 1 being completed first and Lot 8 completed last. Groundwater was generally encountered at 10 feet BGS. Soils Soils encountered during the investigation were visually classified in general accordance with the Unified Soil Classification System (USCS). The general subsurface profile encountered for Lots 1 through 5 consisted of approximately 18 inches of surficial organics followed by dense, sandy gravel with silt. A confining silt layer was found at approximately 10 ft BGS which corresponded with the water table . Lots 6 and 7 had a significantly higher silt content which corresponded to closer proximity to the wetl ands and resulted in slower perc rates. The native soils on Lot 8 were a very clean, sandy gravel beneath the surficial organics. May 2nd, 2023 Subject: Tract B Shangri-la Estates East Phase 2 Subdivision – Septic Analysis & Water Availability Report REV 1 Platting Case TBD Page 4 of 9 EXCELLENCE IN CIVIL ENGINEERING SINCE 1982 • SITE PLANNING • CIVIL ENGINEERING DESIGN • PROJECT MANAGEMENT Bedrock Bedrock was not encountered during the investigation and is not anticipated to negatively impact future development of the lots. Percolation Test Results Below is a summary of the percolation test results by lot and the subsequent reserve area required. See the attached site plan for test hole locations on each lot. Table 1 - Septic Testing Results Summary Test Hole # Lot Perc Rate (min/in) Depth of TH (BGS) Groundwater (Initial) Groundwater Monitoring Reserve Area (ft2) TH-1 Lot 1 <1 10’ 10’ BGS 9’ BGS 10,000 TH-2 Lot 1 <1 10’ 10’ BGS 6.5’ BGS 10,000 TH-3 Lot 2 <1 12’ NGWE NGWE 10,000 TH-4 Lot 3 <1 11’ 10’ BGS NGWE 10,000 TH-5 Lot 4 5.7 11’ 10.5’ BGS 8.5’ BGS 10,000 TH-6 Lot 4 15.0 10’ NGWE 1’ BGS 14,000 TH-7 Lot 5 21.8 11’ 10.5’ BGS 5.3’ BGS 14,000 TH-7A Lot 7 <1 13’ 9’ BGS 8’ BGS 10,000 TH-8 Lot 6 <1 13’ NGWS 11’ BGS 10,000 Nitrate Levels Below is a map of the available nitrate data for the surrounding neighborhoods. Property to the north and east are currently undeveloped. Land to the west is in the early stages of residential development and presently does not contain any septic systems or private wells. Properties to the south and southwest generally show nitrate levels below 5 mg/l with a majority of the results below 2 mg/l. The United States Environmental Protection Agency (EPA) sets the maximum contaminant level for nitrate at 10 milligrams per liter. Of the thirty results available within Shangri-la and Shangri-la East Subdivisions, the average nitrate value is 1.23 mg/l which is well below the 10 mg/l limit. May 2nd, 2023 Subject: Tract B Shangri-la Estates East Phase 2 Subdivision – Septic Analysis & Water Availability Report REV 1 Platting Case TBD Page 5 of 9 EXCELLENCE IN CIVIL ENGINEERING SINCE 1982 • SITE PLANNING • CIVIL ENGINEERING DESIGN • PROJECT MANAGEMENT Nitrate Values App (5/5/23) Groundwater During the initial investigation, groundwater was generally encountered at 10 ft BGS. Additionally, subsurface flows were encountered as weeps in the sidewall of the excavation at approximately 5 -8 ft BGS. The subsurface flows were not substantial and did not affect the perc testing. With the exception of Lot 6, it is unlikely that the water table would negatively impact future septic systems due to the lack of silt content witnessed for the full depth of the test holes. Lot 6 may require the installation of a subdrain to mitigate subsurface flows as part of the on-site system. Seasonal changes to the water table elevation are expected to occur due to rainfall and snow melt runoff. N THIS PROPERTY May 2nd, 2023 Subject: Tract B Shangri-la Estates East Phase 2 Subdivision – Septic Analysis & Water Availability Report REV 1 Platting Case TBD Page 6 of 9 EXCELLENCE IN CIVIL ENGINEERING SINCE 1982 • SITE PLANNING • CIVIL ENGINEERING DESIGN • PROJECT MANAGEMENT Water Availability The Alaska Department of Natural Resources (DNR) online Well Log Tracking System (WELTS) was reviewed to assess water availability in the immediate vicinity of the proposed subdivision. As previously discussed, the properties to the north of this parcel are largely undeveloped. Shangri-La Estates East, located south and west of this parcel, as well as, Rabbit Creek View & Heights located south and east are residential developments with well log data available on WELTS. Below is a screen capture of the area incl uded within the search results of WELTS. The 17.5-acre parcel of Tract B is shown in the map below. Area of Interest for WELTS Search The search resulted in twenty-seven well log ID’s within the area of interest. The results include data on wells drilled from 1982 to as recently as 2019. Approximately 60% of the wells were drilled between 2000 and 2019 . Except for Log ID’s 11311, 31301 and 46014, all results indicate well production greater than 2 gpm. Wells drilled after the year 2000 have an average production rate of 12.2 gpm which is well above the minimum recommended production rate of 1 gpm. Eight wells were drilled beyond 300 feet, however, the remaining wells average 115 feet in depth. The avergae static water level is 51 feet. Based on the data, well production is not a concern for the future development of the lots. Shallow bedrock was encountered for wells drilled to the south of this proposed development which were at significantly higher elevations. A summary of the WELTS search results is provided on the following page. N Subject Property May 2nd, 2023 Subject: Tract B Shangri-la Estates East Phase 2 Subdivision – Septic Analysis & Water Availability Report REV 1 Platting Case TBD Page 7 of 9 EXCELLENCE IN CIVIL ENGINEERING SINCE 1982 • SITE PLANNING • CIVIL ENGINEERING DESIGN • PROJECT MANAGEMENT Table 2 – Well Data for Surrounding Properties Log Id Date of Completion Parcel Description Well Depth Static Water Depth Depth to Bedrock Well Production 5515 08/16/1982 RABBIT CREEK HEIGHTS L01 B1 67 12 GPM 5833 07/09/1984 RABBIT CREEK HEIGHTS L09 B1 130 4 GPM 11311 05/14/1985 HORACE TRACT 1 GOLDENVIEW ASSOCIATION 304 109 302 UNKNOWN 12910 09/19/1985 RABBIT CREEK HEIGHTS L02 B1 51 12 GPM 12994 08/16/1984 RABBIT CREEK HEIGHTS L28 B1 181 20 GPM 31301 10/26/1986 PTARMIGAN ROOST L01 B2 196 8 35 UNKNOWN 31302 08/20/1996 PTARMIGAN ROOST L03 B2 280 10 5 2+ GPM 31303 08/04/1993 PTARMIGAN ROOST L08 B2 165 20 17 3.5 GPM 31304 06/23/1980 PTARMIGAN ROOST L09 B2 148 9 2 GPM 31305 03/17/1994 PTARMIGAN ROOST L02 B3 250 12 18 3+ GPM 31306 09/05/2000 PTARMIGAN ROOST L04 B3 245 24 40 30 GPM 31308 05/23/1984 PTARMIGAN ROOST L07 B3 387 310 27 5 GPM 32547 11/10/2006 HORACE Tr 2 - SHANGRI-LA Ph 2 106 39 16 20+ GPM 32548 11/12/2006 HORACE Tr 2 - SHANGRI-LA L01 B2 406 29 30 2 GPM 32549 11/16/2006 HORACE Tr 2 - SHANGRI-LA L06 B1 326 21 17 4 GPM 40436 05/28/2014 PARCEL: 020-043-77-000, 16369 MOUNTAIN BREEZE DR 344 34 5 7 GPM 40456 05/28/2014 PARCEL: 020-043-77-000, 16369 MOUNTAIN BREEZE DR 344 34 5 2 GPM 41696 09/16/2015 SHANGRI-LA ESTATES EAST L1 B4, 16610 SANDPIPER DR 133 194 5 GPM 45834 06/21/2016 16122 Alta Ct Rabbit Creek View and Heights Block 1H Lot 17A 198 83 20 GPM 46014 02/03/2016 Shangri-La Estates East Block 1 Lot 1 443 25 9 1.5 GPM 54455 12/05/2012 RABBIT CREEK VIEW & HEIGHTS BLK 1H LT 22A 58 20 12 GPM 60835 08/07/2017 SHANGRI-LA ESTATES EAST BLK 3 LT 5 128 25 30 GPM 60836 08/08/2017 SHANGRI-LA ESTATES EAST BLK 1 LT 9A 244 34 10 5 GPM 60838 07/28/2018 SHANGRI-LA ESTATES EAST BLK 3 LT 4 145 45 10 GPM 60840 09/13/2018 SHANGRI-LA LT 18 384 17 3 4 GPM 60855 09/09/2019 SHANGRI-LA ESTATES EAST BLK 2 LT 1 224 31 2.5 GPM 60857 08/10/2017 SHANGRI-LA ESTATES EAST BLK 3 LT 3 119 56 40 GPM Average 226 51 44 10.34 GPM May 2nd, 2023 Subject: Tract B Shangri-la Estates East Phase 2 Subdivision – Septic Analysis & Water Availability Report REV 1 Platting Case TBD Page 8 of 9 EXCELLENCE IN CIVIL ENGINEERING SINCE 1982 • SITE PLANNING • CIVIL ENGINEERING DESIGN • PROJECT MANAGEMENT Conclusion In summary, perc test results indicate that each of the proposed lots contain soils capable of supporting on-site septic systems. Slower perc rates were generally encountered closer to the wetlands, where the in-situ soils had a higher silt content. Well-draining soils were encountered for Lots 1-5 and Lot 8. Groundwater was witnessed at approximately 10 ft below ground surface. Review of available well log information indicates that water is abundant in the area with recently drilled wells averaging 10.3 gpm of production. There is adequate water for wells within both the new proposed lots as well as the existing lots wi thin Shangri-la Estates East. Thank you for your time and consideration in this matter. If you require additional information , please call 907- 720-6128 or email me at grantmathews@triadak.com. Sincerely, Triad Engineering, LLC Grant Mathews, P.E. Attachments: Location Map Perc Test Results E N G I N E E R I N G , L L C BR A N D O N J . M A R C O T T CE 1 2 6 0 1 R E GISTERED PROFE S S I O N A L E N G INEER 5. 1 0 . 2 3 Municipality of Anchorage Development Services Department On -Site Water and Wastewater Section r 4700 Elmore St. P.O. Box 196650 Anchorage, AK 99519-6650 www.muni.org/onsite (907) 343-7904 Soils Log - Percolation Test yl� *; 4 TH g•,* �•� NNTW. THEWS••• �E 135444 Performed For: Scott Grigsby Date Performed: 8-17-22 Legal Description: Shangri-La Tract B (Lot 1) Township, Range, Section: TH-1 1 - Date Organics, root mat, brown (OL) Net Time Water Depth S Sandy silt (ML) 2 - Depth to Water After 0 P Monitoring? 9 -ft E Sandy gravel (GP) 3— 4.0 -ft on 9-2-22 Brown, dense Cobbles up to 12" 4 - 6.000" --- Silty gravel w/ sand (GP -GM) 5- Tan,dense 6- 5 min 10 min 7 - 6.000" Weeps in interbedded sand 8- Sandy gravel w/ silt (GM) 9 - Gray, dense 10- S7 BOH@ 10' 11- 12- 13- 14- 15- 16- 17- 18- 19- 20- r'iL•r WAS GROUND WATER Date ENCOUNTERED? Yes Net Time Water Depth S IF YES, AT WHAT DEPTH? 10 -ft 9:25am Depth to Water After 0 P Monitoring? 9 -ft E Date: 5-5-23 9:30am 4.0 -ft on 9-2-22 5 min Site Plan See attached site plan Reading Date Gross Time Net Time Water Depth Net Drop 9:25am --- --- 6.000" --- 1 9:30am 5 min 5 min 0.000" 6.000" --- --- 6.000" 2 9:35am 5 min 10 min 0.000" 6.000" PERCOLATION RATE <1 (minutes/inch) PERC HOLE DIAMETER 6° TEST RUN BETWEEN 3 FT AND 4 FT COMMENTS Added approximately 2 gallons of water in less than 1 minute. All water absorbed in less than 5 minutes. Repeated w/ same results. PERFORMED BY: Triad Engineering, LLC I Grant Mathews CERTIFY THAT THIS TEST WAS PERFORMED IN ACCORDANCE WITH ALL STATE AND MUNICIPAL GUIDELINES IN EFFECT ON THIS DATE. DATE: 10-21-22 Municipality of Anchorage Development Services Department On -Site Water and Wastewater Section 4700 Elmore St. P.O. Box 196650 Anchorage, AK 99519-6650 www.muni.org/onsite (907) 343-7904 Soils Log - Percolation Test Performed For: Scott Grigsby Legal Description: Shangri-La Tract B (Lot 1) TH-2 1- 2- 3- 4- 5- 6- 7- 8- 9- 10- 11- 12- 13- 14- 15- 16- 17- 18- 19- 20 - owNC T Organics, root mat, brown (OL) Sandy gravel (GP) Tan, dense Cobbles up to 6" Silty gravel w/ sand (GP -GM) Sandy gravel w/ silt (GM) Gray, dense 1 rte.• v � *: 49 TH •.* �• AN M EWS••�• E 135444 ,•c�� pROFE" is1�NP� Date Performed: 8-17-22 Township, Range, Section: Weeps WAS GROUND WATER Gross Time Net Time ENCOUNTERED? Yes Net Drop 10:05am S L --- IF YES, AT WHAT DEPTH? 10 -ft --- BOH @ 10'0 Depth to Water After P 6 min Monitoring? 9.5 -ft E Date: 5-5-23 --- --- 6.5 -ft on 9-2-22 --- Site Plan See attached site plan Reading Date Gross Time Net Time Water Depth Net Drop 10:05am --- --- 6.000" --- 1 10:11 am 6 min 6 min 0.000" 6.000" --- --- 6.0 0 0" --- 2 10:17am 6 min 12 min 0.000" 6.000" PERCOLATION RATE <1 (minutes/inch) PERC HOLE DIAMETER 6" TEST RUN BETWEEN 2.5 FT AND 3.5 FT COMMENTS Added approximately 2 gallons of water in less than 1 minute. All water absorbed in less than 6 minutes. Repeated w/ same results. PERFORMED BY: Triad Engineering, LLC I Grant Mathews CERTIFY THAT THIS TEST WAS PERFORMED IN ACCORDANCE WITH ALL STATE AND MUNICIPAL GUIDELINES IN EFFECT ON THIS DATE. DATE: 10-21-22 Municipality of Anchorage Development Services Department On -Site Water and Wastewater Section r 4700 Elmore St. P.O. Box 196650 Anchorage, AK 99519-6650 www.muni.org/onsite (907) 343-7904 Soils Log - Percolation Test Performed For: Scott Grigsby Legal Description: Shangri-La Tract B (Lot 2) TH-3 1 - Date Organics, root mat, brown (OL) Net Time 2- S Silty gravel w/ sand (GP -GM) Tan, dense 3- Depth to Water After O P Monitoring? NGWE 4 - Date: 5-5-23 10:49am 8.0 -ft on 9-2-22 2 min Sandy gravel (GP) 5 - Gray, desnse 6- --- 6.00011 --- 7- 10:51 am 2 min 8- 0.000" 6.000" Silty gravel w/ sand (GP -GM) 9— Higher silt content Gray, dense 10- 11- 12— BOH @ 12' NGWE 13- 14- 15- 16- 17- 18- 19- 20- �� oF,A�q!i11 *;A OTH •,* .,..... 41W • • RANT W. MATHEWS 9� �E 135444 l�>1��pROFESSIO�P .� Date Performed: 8-17-22 Township, Range, Section: Site Plan See attached site plan WAS GROUND WATER Date ENCOUNTERED? No Net Time Water Depth S IF YES, AT WHAT DEPTH? L Depth to Water After O P Monitoring? NGWE E Date: 5-5-23 10:49am 8.0 -ft on 9-2-22 2 min Reading Date Gross Time Net Time Water Depth Net Drop 10:47am --- --- 6.000" --- 1 10:49am 2 min 2 min 0.000" 6.000" --- --- 6.00011 --- 2 10:51 am 2 min 4 min 0.000" 6.000" PERCOLATION RATE <1 (minutes/inch) PERC HOLE DIAMETER 6° TEST RUN BETWEEN 3.5 FT AND 4.5 FT COMMENTS Added approximately 1 gallon of water in less than 1 minute. All water absorbed in less than 2 minutes. Repeated w/ same results. PERFORMED BY: Triad Engineering, LLC I Grant Mathews CERTIFY THAT THIS TEST WAS PERFORMED IN ACCORDANCE WITH ALL STATE AND MUNICIPAL GUIDELINES IN EFFECT ON THIS DATE. DATE: 10-21-22 Performed For: Legal Description TH-4 Municipality of Anchorage Development Services Department On -Site Water and Wastewater Section r 4700 Elmore St. P.O. Box 196650 Anchorage, AK 99519-6650 www.muni.org/onsite (907) 343-7904 Soils Log - Percolation Test �� OF. ACgsl *: 49 TH •.* G N• .MATHEWS•••' C 135444 lV)ZOPROFESS0 r Scott Grigsby Date Performed: 8-17-22 Shangri-La Tract B (Lot 3) Township, Range, Section: JIV Site Plan See attached site plan WAS GROUND WATER Date Organics, root mat, brown (OL) 1 - Water Depth S IF YES, AT WHAT DEPTH? 10 -ft L Silty sand, brown (SM) 2- Monitoring? NGWE E 3- 11:28am 3 min 4— 0.000" Sandy gravel (GP) Gray, dense 5 - 6.000" Cobbles up to 6" 6- 11:31 am 3 min 7— 0.000" Interbedded silt lenses 8- 9- 10- `7 Silt w/ gravel, dense (ML) 11 BOH @ 11' 12- 13- 14- 15- 16- 17- 18- 19- 20 - JIV Site Plan See attached site plan WAS GROUND WATER Date ENCOUNTERED? Yes Net Time Water Depth S IF YES, AT WHAT DEPTH? 10 -ft L Depth to Water After 0 P Monitoring? NGWE E Date: 5-5-23 8.0 -ft on 9-2-22 Reading Date Gross Time Net Time Water Depth Net Drop 11:25am --- --- 6.000" --- 1 11:28am 3 min 3 min 0.000" 6.000" --- --- 6.000" 2 11:31 am 3 min 6 min 0.000" 6.000" PERCOLATION RATE <1 (minutes/inch) PERC HOLE DIAMETER 6" TEST RUN BETWEEN 3 FT AND 4 FT COMMENTS Added approximately 2 gallons of water in less than 1 minute. All water absorbed in less than 3 minutes. Repeated w/ same results. PERFORMED BY: Triad Engineering, LLC I Grant Mathews CERTIFY THAT THIS TEST WAS PERFORMED IN ACCORDANCE WITH ALL STATE AND MUNICIPAL GUIDELINES IN EFFECT ON THIS DATE. DATE: 10-21-22 Municipality of Anchorage Development Services Department On -Site Water and Wastewater Section 4700 Elmore St. P.O. Box 196650 Anchorage, AK 99519-6650 www.muni.org/onsite (907) 343-7904 Soils Log - Percolation Test Performed For: Scott Grigsby Legal Description: Shangri-La Tract B (Lot 4) TH-5 1 - Date Organics, root mat, brown (OL) Net Time 2- s Sandy gravel w/ silt (GM) Brown, dense 3 - Depth to Water After 0 P Monitoring? 8.5 -ft 4- Date: 5-5-23 Silty gravel w/ sand (GP -GM) Tan, dense 5 - 25 min 0.000" 6.000" 6- Sandy gravel (GP) Gray, dense 7- 6.000" Weeps 8- 1:12pm 32 min 9- 0.000" 6.000" 1 o- --- 11 _ 6.00011 silt (ML) 3 1:46pm BOH @ 11' 12- 0.000" 6.000" 13- 14- 15- 16- 17- 18- 19- 20 - COMMENTS oF' A�SiI �,�P.••'' .tel 1 '49TH *� .... ............... •. ANT ATHEWS•••• I9� //CE 135444 .•c$� 006 PRO Date Date Performed: 8-17-22 Township, Range, Section: Site Plan See attached site plan WAS GROUND WATER Date ENCOUNTERED? Yes Net Time Water Depth s IF YES, AT WHAT DEPTH? 10.5 -ft L Depth to Water After 0 P Monitoring? 8.5 -ft E Date: 5-5-23 12:40pm 8.0 -ft on 9-2-22 25 min Reading Date Gross Time Net Time Water Depth Net Drop 12 :15 p m --- --- 6.00011 --- 1 12:40pm 25 min 25 min 0.000" 6.000" --- --- 6.000" --- 2 1:12pm 32 min 57 min 0.000" 6.000" --- --- 6.00011 --- 3 1:46pm 34 min 91 min 0.000" 6.000" PERCOLATION RATE 5.7 (minutes/inch) PERC HOLE DIAMETER 6" TEST RUN BETWEEN 3 FT AND 4 FT . PERFORMED BY: Triad Engineering, LLC I Grant Mathews CERTIFY THAT THIS TEST WAS PERFORMED IN ACCORDANCE WITH ALL STATE AND MUNICIPAL GUIDELINES IN EFFECT ON THIS DATE. DATE: 10-21-22 Municipality of Anchorage Development Services Department On -Site Water and Wastewater Section y� 4700 Elmore St. P.O. Box 196650 Anchorage, AK 99519-6650 www.muni.org/onsite (907) 343-7904 Soils Log - Percolation Test Performed For: Legal Description 1- 2- 3- 4- 5- 6- 7- 8- 9- 10- 11- 12- 13- 14- 15- 16- 17- 18- 19- 20 - rte'• TH *: 4 �• N ATHEWS�� ' QFC , • CE 135444 1N'I�ROFE SI Scott Grigsby Date Performed: 8-17-22 Shangri-La Tract B (Lot 4) Township, Range, Section: TH-6 Date Depth Water Depth (Feet) S BOH @ 10' IF YES, AT WHAT DEPTH? Organics, root mat, black (OL) NGWE Depth to Water After Silt w/ gravel & sand (ML) Monitoring? 1 -ft Silt w/ cobbles (ML) 0.0 -ft on 9-2-22 Date: 5-5-23 Blue, dense 33 min Silty, sandy gravel (GP -GM) 3.000" Gray, dense Weeps in interbedded sand COMMENTS E WAS GROUND WATER Date ENCOUNTERED? No Water Depth Net Drop S BOH @ 10' IF YES, AT WHAT DEPTH? L NGWE Depth to Water After 0 P Monitoring? 1 -ft E 0.0 -ft on 9-2-22 Date: 5-5-23 33 min Site Plan See attached site plan Reading Date Gross Time Net Time Water Depth Net Drop 1:55pm --- --- 6.000" --- 1 2:28pm 33 min 33 min 3.000" 3.000" --- --- 6.000" --- 2 2:58pm 30 min 63 min 3.500" 2.500" --- --- 6.0 0 0" --- 3 3:28pm 30 min 93 min 4.000" 2.000" --- --- 6.0 0 0" 4 3:58pm 30 min 123 min 4.000" 2.000" PERCOLATION RATE 15.0 (minutes/inch) PERC HOLE DIAMETER 6" TEST RUN BETWEEN 5 FT AND 6 FT PERFORMED BY: Triad Engineering, LLC I Grant Mathews CERTIFY THAT THIS TEST WAS PERFORMED IN ACCORDANCE WITH ALL STATE AND MUNICIPAL GUIDELINES IN EFFECT ON THIS DATE. DATE: 10-21-22 Municipality of Anchorage Development Services Department On -Site Water and Wastewater Section y�r 4700 Elmore St. P.O. Box 196650 Anchorage, AK 99519-6650 www.muni.org/onsite (907) 343-7904 Soils Log - Percolation Test Performed For: Scott Grigsby Legal Description: Shangri-La Tract B (Lot 5) 1- 2- 3- 4- 5- 6- 7- 8- 9- 10- 11- 12- 13- 14- 15- 16- 17- 18- 19- 20 - TH-7 WAS GROUND WATER Depth Net Time (Feet) Net Drop Silty gravel (GM) Organics, root mat, black (OL) S Silt, brown (ML) IF YES, AT WHAT DEPTH? 10.5 -ft � Silty gravel w/ sand (GP -GM) Depth Water Cobbles up to 12" 37 min Tan, dense COMMENTS Slope 4N��T. `r-FS, E 135444 0 5e2?�� ROFESSI Date Performed: 8-17-22 Township, Range, Section: Silty gravel w/ sand (GP -GM) Brown, dense, moist WAS GROUND WATER Gross Time Net Time ENCOUNTERED? Yes Net Drop Silty gravel (GM) 2:41 pm S Bluish gray IF YES, AT WHAT DEPTH? 10.5 -ft � 1 Depth Water 0 37 min to After P Silt (ML) Monitoring? 5.3 -ft E BOH @ 11' 6.000" --- 2 Date: 10-28-22 32 min 69 min 6.0 -ft on 9-2-22 1.375" Site Plan See attached site plan Reading Date Gross Time Net Time Water Depth Net Drop 2:41 pm --- --- 6.00011 --- 1 3:18pm 37 min 37 min 4.000" 2.000" --- --- 6.000" --- 2 3:50pm 32 min 69 min 4.625" 1.375" --- --- 6.0 0 0" --- 3 4:20pm 30 min 99 min 4.625" 1.375" PERCOLATION RATE 21.8 (minutes/inch) PERC HOLE DIAMETER 6° TEST RUN BETWEEN 5 FT AND 6 FT PERFORMED BY: Triad Engineering, LLC I Grant Mathews CERTIFY THAT THIS TEST WAS PERFORMED IN ACCORDANCE WITH ALL STATE AND MUNICIPAL GUIDELINES IN EFFECT ON THIS DATE. DATE: 10-21-22 Performed For: Legal Description TH-7A 1- 2- 3- 4- 5- 6- 7- 8- 9- 10- 11- 12- 13- 14- 15- 16- 17- 18- 19- 20 - Municipality of Anchorage Development Services Department On -Site Water and Wastewater Section 4700 Elmore St. P.O. Box 196650 Anchorage, AK 99519-6650 www.muni.om/onsite (907) 343-7904 Soils Log - Percolation Test Scott Grigsby Shangri-La Tract B (Lot 7) Organics, Root Mat (OL) Brown Gravelly Sand (SP), Med Dense, Gray Gravel (GW), Med Dense, Brown BOH @ 9' Groundwater Encountered Date Performed: Township, Range, Section: Ci WAS GROUND WATER Date ENCOUNTERED? Yes Depth to Water s IF YES, AT WHAT DEPTH? 9' L Depth to Water After 0 P Monitoring? 8 -ft E Date: 5-5-23 (ENGINEER'S SEAL) 11""4 'X' ��?• •AIW • 911+ *:49R •,*i �Yah�loN Nl�cott` • • •BRANDON J�MARCOTT • • •, 9•' CE 12601 ,•�� 10-21-22 Site Plan See Attached Site Plan Reading Date Gross Time Net Time Depth to Water Net Drop 1:15pm 6.000" 1 1:18pm 3 min 3 min 0.000" 6.000" 1:19pm 6.000" 2 1:22pm 3 min 7 min 0.000" 6.000" 1:23 p m 6.000" 3 1:26pm 3 min 11 min 0.000" 6.000" PERCOLATION RATE <1 (minutes/inch) PERC HOLE DIAMETER 4" TEST RUN BETWEEN 4 FT AND 5 FT COMMENTS Added approx 1 gallon of water in less than 1 min. All water absorbed approx 3. Repeated again with same results. Pre-soaking not required. PERFORMED BY: Triad Engineering, LLC Brandon Marcott, P.E. CERTIFY THAT THIS TEST WAS PERFORMED IN ACCORDANCE WITH ALL STATE AND MUNICIPAL GUIDELINES IN EFFECT ON THIS DATE. DATE: 10-21-22 Municipality of Anchorage Development Services Department On -Site Water and Wastewater Section 4700 Elmore St. P.O. Box 196650 Anchorage, AK 99519-6650 www.muni.org/onsite (907) 343-7904 Soils Log - Percolation Test Performed For: Scott Grigsby Legal Description: Shangri-La Tract B (Lot 6) TH-8 1 - 2- Date Organics, root mat, brown (OL) Net Time 3- Net Drop 4- --- --- 5- --- Sandy gravel (GP) 3:42pm 2 min Well graded 6- 6.000" Transitioning from --- brown to grey w/ depth, dense 7- --- 2 8- 2 min 4 min 9- 6.000" 10- 11- 12- 13- BOH @ 13' NGWE 14- 15- 16- 17- 18- 19- 20 - Date Performed: 8-17-22 Township, Range, Section: Site Plan See attached site plan WAS GROUND WATER ENCOUNTERED? No s IF YES, AT WHAT DEPTH? L Depth to Water After P Monitoring? 11 -ft E Date: 5-5-23 NGWE on 9-2-22 Reading Date Gross Time Net Time Water Depth Net Drop 3:40pm --- --- 6.000" --- 1 3:42pm 2 min 2 min 0.000" 6.000" --- --- 6.000" --- 2 3:44pm 2 min 4 min 0.000" 6.000" PERCOLATION RATE <1 (minutes/inch) PERC HOLE DIAMETER 6" TEST RUN BETWEEN 3 FT AND 4 FT COMMENTS Added approx 2 gallons of water in less than 1 min. All water absorbed in less than 2 min. Repeated with same results. PERFORMED BY: Triad Engineering, LLC I Grant Mathews CERTIFY THAT THIS TEST WAS PERFORMED IN ACCORDANCE WITH ALL STATE AND MUNICIPAL GUIDELINES IN EFFECT ON THIS DATE. DATE: 10-21-22