HomeMy WebLinkAboutSHANGRI-LA ESTATES-EAST PH 2 S12704Onsite File
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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
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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