HomeMy WebLinkAboutGRANDEUR S11168Grand
wr'
5
-11168
#020-571-61
Lang & Associates, inc.
11500 Daryl Avenue
(907) 522-6476
(907) 522-4625 Fax
Registered Professional Land Surveyors
Anchorage, Alaska 99515-3049
March 31,2005
Municipality of Anchorage
Department of Community Planning & Development
P.O. Box 196650
Anchorage, Alaska 99519
Attn: Jerry T. Weaver, Jr.
Platting Officer
Dear Mr. Weaver,
The preliminary plat for this subdivision was reviewed by your office on October 27, 2003 and
returned to us for redesign and modification. To improve accessibility to the lots we have combined
the previous lots 1 and 2 into one lot. Attached is a revised preliminary plat with the new configuration.
With this submittal we are addressing your concerns as follows:
1. Soils tests have been performed on the proposed lots by Anderson Engineering and the results are
attached.
2. We have calculated lot slopes as you requested. The calculations used the equation S= I x L x 0.0023
/ A as shown in section 21.40.115F of Title 21. We used lot area values which include one-half of the
right-of-way area as provided by the ordinance. The results are as follows:
Lot 1
Lot 2
Lot 3
Lot 4
Lot 5
20 x 2520 x 0.0023 / 5.00 = 23.18 % (area required= 2.5Ac; area provided= 5.0Ac)
20 x 1225 x 0.0023 / 2.50 ~- 22.54 % (area required= 2.5 Ac; area provided= 2.5 Ac)
20 x 5090 x 0.0023/7.50 = 31.22 % (area required= 7.5 Ac; area provided= 7.5 Ac)
20 x 5235 x 0.0023 / 7.50 = 32.11% (area required= 7.5 Ac; area provided= 7.5 Ac)
20 x 5920 x 0.0023 / 7.50 = 36.31% (area required- 7.5 Ac; area provided= 7.5 Ac)
3. Driveway grades are addressed on the enclosed exhibit A. A proposed street profile is enclosed as
exhibit B.
Please let us know if you need any additional information.
u an' L.S.
Petitioner's Repr~'sentative
Lang & Associates, inc.
11500 Daryl Avenue
(907) 522-6476
(907) 522-4625 Fax
Registered Professional Land Surveyors
Anchorage, Alaska 99515-3049
EXHIBIT A
GRANDEUR SUBDIVISION
PROPOSED DRIVEWAYS
TEMPORARY CUL-DE-SAC
~7.46 Acres
(7.50 ~cres)..~
Tracf C
2.36 ~cres
~cres)
Acres) x,.
· Lof 1
=9.0''~5.
UNE ~
11
SIDE
M A R G U E
Lot-
R T E
lA- 1
H J
Lang & Associates, inc.
11500 Daryl Avenue
(907) 522-6476
(907) 522-4625 Fax
Registered Professional Land Surveyors
Anchorage, Alaska 99515-3049
EXHIBIT B
GRANDEUR SUBDMSION
PROPOSED STREET PROFILE
0
ANDERSON ENGINEERING
P.O. BOX 240773
ANCHORAGE, AK 99524
522-7773 522-6779 (FAX)
March 1, 2005
Joe Burnham
1120 E. Huffman Road
Anchorage, AK 99515
Su~e~:
Grandeur Subdivision
Geotechnical Investigation and Septic System Feasibility
Dear Joe:
We recently completed a geotechnical investigation and septic feasibility study on a 30-
acre parcel located just south of Paine Road in Bear Valley. Our directive was to log
test holes and perform percolation tests at locations determined by you and your
surveyor, Lang and Associates, Inc. Test holes were placed on each of the 5 lots
proposed for the subdivision just off of the proposed Paine Circle. The locations of the
test holes were determined based on ease of access. The parcel is located on sloping
terrain with a northern exposure and the proposed lots are considered prime view lots.
Large trees are found throughout the area and our intent was to limit the damage
caused by the tracked backhoe and clearing required to facilitate access.
A total of 10 test holes were placed on the parcel. You excavated the holes with a
tracked backhoe to depths ranging in depth from 5' to 13'. In every case bedrock was
encountered at the bottom of each hole. A monitor tube was placed in each hole where
appropriate to determine the elevation of groundwater over the coming months.
Pemolation benches were constructed at various depths, but primarily between 3' and 7'
below the surface. A percolation cavity was prepared to determine the absorptive
characteristics of the soils encountered in the test holes. The cavity was presoaked in
accordance with Municipal requirements and a percolation test performed. The results
of the tests are included in the attached documentation.
The underlying soil materials encountered in the test holes was faidy consistent and
composed primarily of silty gravel (SM) with varying amounts of coarse sand. Silt
contents ranged from 15% to 40% from visual observation. The vast majority of the test
holes revealed silt contents at the lower end of the range. The percolation rate of the
material was found to be less than 5 minutes per inch in the majority of holes, with Test
Hole No. 1 much slower at 79 minutes per inch. Groundwater was found in only Test
Hole No. 1 probably due to the higher silt content of the soil material.
Grandeur Subdivision
March 1, 2005
Page 2
The ground surface slope throughout the subdivision is steep and ranges between 18%
and 50%. Some areas are available with much less slope, but test holes were not
placed in these areas due to access problems and the desire to limit damage to the
vegetation and terrain. The proposed lots for this subdivision are large. When building
sites are determined areas will be explored to determine actual septic system sites.
The Municipal ordinance governing septic systems does not allow construction of a
septic system at or near a slope greater than 25%. Bed systems cannot be placed on a
slope greater than 10%. An accurate topographic survey of the subdivision will be
required to verify the surface slope at the location of the proposed septic systems.
Grading will probably be required in the areas proposed for septic, systems to assure
separation distances from extreme slopes are met.
The Municipal ordinance also requires a minimum of 6' separation between bedrock
and the bottom of any absorption system. This can be achieved by mounding above
original ground using coarse sand and placing the absorption system atop the sand.
In summary, soils conditions encountered on the proposed lots are conducive for the
placement of individual septic systems. Grading will be required to prepare the septic
system sites to insure required separation distances from slopes greater than 25% are
met.
Sincerely,
Michael E. Anderson, P.E.
Attachments
GRANDEUR SUBDIVISION
TEST HOLE LOCATION PLAN
SCALE1"=200'
£
$
5
6
7
8
9
II
PROJECT #:
PERFORMED FOR:
MUNICIPALITY OF ANCHORAGE
DEVELOPMENT SERVICES DEPARTMENT
4700 SOUTH BRAGAW STREET, ANCHORAGE, AKggsIg-6~50
SOILS LOG - PERCOLATION TEST
Joa BOrnham
DATE PERFORMED: 10/27/0z~
lEG.AL DESCRIPTION: Grandeur SubdiVision
18¸
COMMENTS:
TEST HOLE
Organic Material
06/OL
Sitty 6raver
0tire/Damp
SLOPE
SITE PLAN
SEE SITE PLAN AND
SUBDIVISION CONTOUR HAP
'WAS GROUNDWATER
ENCOUNTERED?
IF YES, WHAT DEPTH?
DEPTH OF WATER
AF:FER MONITORING:
DATE:
Bedrocl~ L~ 12'
~(~'.*. . ...-'. ~
No S
L
0
P
9'
11/12/0z~
GROSS ~ET DEPTH OF NET
READING DATE
TIME . ~IME WATER DROP
1 10/31 1:50 6.5"
2 :~:20 30 6.12" 38"
3 2:50 30 5.75"' 38"
Z~ 3:20 30 5.37" .38" '
PERC RATE: 79 MIN./INCH PERC, HOLE DIAMETER: 6"
TEST RUN BETWE~N /~ FT. AND 5 FT.
Test Hote Pre Soaked Prior to Percolation Test.
TEST PERFORMED BY: A._U_H l, MICHAEL E. ANDERSON, CERTIFY THAT THIS TEST WAS PERFORMED IN ACCORDANCE
WITH ALL STATE AND MUNICIPAL GUIDELINES ON THIS DATE: 11/19/200~,
PROJECT #:
PERFORMED FOR:
HUNICIPALITY oF ANCHORAGE
DEVELOPMENT SERVICES DEPARTMENT
4700 SOUTH BRAGAW STREET, ANCHORAGE, AKggSI9-6650
SOILS LOG -PERCOLATION TEST
Joe Burnham
DATE PERFORMED.' 10/27/0/+
LEGAL DESCRIPTION: Grandeur Subdiviaion
2
3
5
6
7
8
9
II
18.
COMMENTS:
· TEST HOLE
Organic Maferial
06/OL
Silly Gravel
GM
Otive/Damp
BedrocN L~ 6'
SLOPE
SITE PLAN
SEE SiTE PLAN AND
SUBDIVISION CONTOUR MAP
WAS GROUNDWATER
ENCOUNTERED?
IF YES, WHAT DEPTH?
DEPTH OF WATER
AFTER MONITORING:
DATE:
No S
L
0
P
None
E
11/12/0~r
[ GROSS NET DEPTH OF NET
READING
DATE
I
TIME TIME WATER DROP
1 I 10/31 1:08 8.75"
2 1:38 30 7" -1.75"
3 2:08 30 5,?5" 1.25"
~' 2:38 . 30 /+.5" 1,25"
PERC RATE:· 2/+ MIN,/INCH PERC. HOLE ·DIAMETER: 6"
TEST RUN BETWEEN 3 FT, AND /+ FT,
. Tesf Hole Pre Soaked Prior fo Percot~fion Tesh
TEST PERFORMED BY: AH I, MICHAEL .E. ANDERSON, CERTIFY THAT THIS TEST WAS PERFORMED tN ACCORDANCE
WiTH ALL STATE AND MUNICIPAL GUIDELINES ON THIS DATE: 11/19/200~
PROJECT ~:
PERFORMED FOR:
MUNICIPALITY OF ANCHORAGE
DEVELOPMENT SERVICES DEPARTMENT
&700-SOUTH BRAGAW STREET, ANCHORAGE, AK9951~-6650
SOILS LOG - PERCOLATION TEST
Joe Burnham
DATE PERFORMED: lO/28/0/+
LEGAL DESCRIPTION! Grandeur SubdivisiOn
2
$
4.
5
6
7
8
g
COMMENTS;
TEST HOLE
Organic H~ferial
0G/0L
SiU'y Graver
.<20% Sitl' (Est'.)
Some Dark Brown
Coaroe Sand
ML/GM
3 SLOPE
SITE PLAN.
SEE SITE PLAN AND
SUBDIVISION CONTOUR MAP
Damp
Bedrock ~ 11'
WAS GROUNDWATER
ENCOUNTERED?
IF YES, WHAT DEPTH?
DEPTH OF WATER
AFTER MONITORING:
DATE:
No
None
11/12/04
L
O
P
E
GROSS NET DEPTH OF NET
READING DATE TIME TIME WATER DROP
1 10/31 11:¢0 2.88"
2 11:50 10 /+.75" 3.13"
3 11:51
Z~ 12:01 10 5" 3"
5 12:02 8,13"
6 i2:12 10 '5.13" 3"
PERC RATE: 3.3 MIN./INCH RERC. HOLE DIAMETER:
TEST RUN BETWEEN 3 FT. AND /~ FT.
Tesf Hote Pre Soaked Prior l'o Percotafion Tesf.
TEST PERFORMED BY: AH I, MICHAEL E, ANDERSON, CERTIFY THAT TH1S TEST WAS PERFORMED IN ACCORDANCE
WITH ALL STATE AND MUNICIPAL GUIDELINES ON THIS DATE: 11/19/2D0~
PROJECT ¢--,:
PERFORMED FOR:
MUNICiPALiTY OF ANCHORAGE
DEVELOPMENT SERVICES DEPARTMENT
SOUTH BRAGAW STREET, ANCHORAGE,.AKg~9519-6650
SOILS LOG - PERCOLATION TEST
Joe Burnham
DATE PERFORMED: lO/28/04
12EGAL DESORIPTION: Grandeur Subdivisidn
2
5
7
8
COMMENTS:
'TEST HOLE
Organic Maferiat
0G/0L
Sitfy Grave[
,,15% Sitf {Eof,)
Some Tan/Brown
Eoarse Sand
SLOPE
SITE PLAN
SEE SITE PLAN AND
SUBDIVISION EONTOUR MAP
WAS GROUNDWATER
ENCOUNTERED? No
IF YES, WHAT DEPTH? .
DEPTH OF WATER ' None
AFTER MONITORING:
DATE: 11/12/04
S
L
O
P
E
READING DATE GROSS NET DEPTH OF NET
TIME TIME WATER DROP
1 10/31 11fZ~0 ' 7.5"
2 11:50 10 4.13" 3.37"
3 11~51 8"
4 I2:01 10 4.75" 3.25"
5 12:02 8,13"
6 12:12 10 4.88" 3.25"
PERC R~TE: 3.1 MIN./INCH PERC. HOLE DIAMETER: 6"
TEST RUN BETWEEN 3 FT. AND 4 FT.
Tesf Hote Pre SoaRed Prior fo P~rcotafion Test.
TEST P~RFORMED BY:
I, MICHAEL E. ANDERSON, CERTIFY THAT THIS'TEST WAS PERFORMED IN ACCORDANCE
WITH ALL STATE AND MUNICIPAL GUIDELINES ON THIS DATE: 11/19/2004
2
3
7
18
PROJECT ~:
PERFORMED FOR:.
LEGAL DESCRIPTION:
COMMENTS:
MUNICIPALITY OF ANCHORAGE
DEVELOPMENT SERVICES DEPARTMENT
-4700 SOUTH BRAGAW STREET, ANCHORAGE, AK99519-6650
SOILS LOG - PERCOLATION TEST
Joe Burnham
DATE PERFORMED: 10/28/0z~
Grandeur Subdivision
TEST HOLE
Organic Material
OG/OL
Sitt-y (3ravel
<15% Silt (EsfJ
Bedrock 0 8'
s SLOPE
SITE PLAN
SEE SITE PLAN AND
SUBDIVISION .CONTOUR MAP
WAS GROUNDWATER
ENCOUNTERED?
IF YES, WHAT DEPTH?
DEPTH OF WATER
AFTER MONITORING:
DATE:
No S
L
0
P
No.e E
11/1210/,
GROSS NET DEPTH OF NET
READING DATE TIME T~ME WATER · DROP
1 10/31 11:0/+ 8"
~ I 11:1A, 10 /~.5" 33"
3 ~1:15 7.75"
& 11:25 10 435" 3"
S 11:26 8.13"
6 11:36 ~O 5.13" 3"
I I
PERC RATE: 3]3 . MIN./INCH PE~C. HOLE D~A~ETER:
T~ST RUN BETWEEN 3 .FT. AND /+ FT.
Test Hole Pre Soaked Prior to Percolation Test,
TEST PERFORMED BY: AH l, MICHAEL E. ANDERSON, CERTIFY THAT THIS 'TEST WAS PERFORMED IN ACCORDANCE
WITH ALL' STATE AND MUNICIPAL GUIDELINES ON THIS DATE: 11/19/200,%
PROJECT ¢:
PERFORMED FOR:
LEGAL DESCRIPTION:
MU~ICIPACITY OF ANCHORAGE
DEVELOPMENT SERVICES DEPARTMENT
SOUTH BRAGAW STREET, ANCHORAGE, AK99519-6650
SOILS LOG- PERCOLATION TEST
Joe Burnham
DATE PERFORMED: 10/28/0/,
Grandeur Subdivision
2
3
5
6
7
8
g
18
COMMENTS:
TEST HOLE
'Organic Materia[
OG/OL
Si[fy Grave[
GM
<15% Sitf
Bedrock
6 SLOPE
SITE PLAN .
SEE SITE PLAN AND
SUBDIVISION CONTOUR HAP
WAS GROUNDWATER
ENCOUNTERED?
IF YES, WHAT DEPTH2
DEPTH OF WATER
AFTER MONITORING:
DATE:
No S
L
0
P
None
E
.11/12/0~
GROSS NET DEPTH OF NET
READING DATE
TIME TIME WATER ~)ROP
1 10/31 3:30 7,63"
2 3:~,0 10 3.25" 4-38"
3 3:41 7.38" '
4- 3:51 10 3.63" 3.75"
5 3:52 7.25"
6 ~:02 10 33" 3.'/5"
PERC RATE: 2.7 MIN./INCH PERC. HOLE DIAMETER: 6"
TEST RUN BETWEEN 3 FT. AND /+ FT:
'Tesf Hole Pre Soa~ed Prior to PercotaHon Test.
TEST PERFORMED B~: A_.~H I, F'itCH~;EL E. ANDERSON, CERTIFY THAT THIS TEST WAS pERFoRMED IN ACCORDANCE
WITH ALL STATE AND MUNICIPAL GUIDELINES ON THIS DATE: 11/19/200~-
PROJECT #:
PERFORMED FOR:
MUNICIPALITy OF ANCHORAGE
DEVELOPMENT SERVICES DEPAF2TMENT
/~?00 SOUTH BRAGAW STREET, ANCHORAGE, AK99519-6650
SOILS LOG - PERCOLATION TEST
Joe Burnham
DATE PERFORMED: 10/28/0/+
LEGAL DESCRIPTION: 8randeur Subdivision
2
5
/+
5
6
7
8
9
18
COMMENTS:
TEST HOLE
QrganicMaferiat
OG/OL
Sitfy 6ravel
BM
Some Fractures
Bedrock C~ 5'
SLOPE
SITE PLAN
SEE SITE PLAN AND
SUBDIVISION CONTOUR MAP
WAS GROUNDWATER
ENCOUNTERED? No S
L
IF YES, WHAT DEPTH? O
P
DEPTH OF WATER None
AFTER i~IONITORING: E
DATE: 11/12/0Z,
GROSS NET DEPTH OF NET
READING DATE·
TIME TIME , WATER DROP
2 10:2~ 10 ~.5" 3.63"
' 3 10:25 8.25"
~ 10:35 10 &.?5" 3,5"
5' 10:36 8.13"
6 10:~6 10 &63" 3,5"
PERC RATE: ~.,,9 MIN./INCH PERC. HOLE DIAMETER:. 6",
'TEST RUN BETWEEN 3 FT, AND & FT.
Test Hote Pre Soaked Prior to Percolation Test.
TEST PERFORMED BY: A_~H I, MICHAEL E. ANDERSON, CERTIFY THAT THIS TEST WAS PERFORMED IN ACCORDANCE
WITH ALL STATE AND MUNICIPAL GUIDELINES ON THIS DATE: ' 11/19/200/~
5
6
7
8
PROJECT #:
PERFORMED FOR:
LEGAL DESCRIPTION:
11--
12--
15--
17--
18-
COMMENTS:
MUNICIPALITY OF ANCHORAGE
DEVELqPMENT SERVICES DEPARTMENT
&700 SOUTH BRAGAW STREET, ANCHORAGE; AK99519-6650
SOILS LOG - PERCOLATION TEST
Joe Burnham
DATE PERFORMED: 10/28704 .
Grandeur Subdivision .
TEST HOLE # 8
Organic Haferiat
0d/0L
Sil~y Gravel
Olive/Damp
SLOPE
SITE PLAN
SEE SITE PLAN AND
SUBDIVISION CONTOUR MAP
WAS GROUNDWATER
ENCOUNTERED?
IF YES, WHAT DEPTH? ~
DEPTH OF WATER None
AFTER MONITORING:
DATE: 11/12104
No S
L
0
P
E
GROSS NET DEPTH OF NET
READING DATE . TINE TIME WATER DROP
1 ' 10/31 1:1'7 '7.38"
2 1:~-'/ 30 6~' 1.3B"
3 2:1'7 30 /+.'75" 1.25"
z~ 2:/*7 30 3.5" 1.25"
I
PERC RATE: 2b MIN./INCH PERC. HOLE DIAMETER:= 6"__
TEST RUN BETWEEN 3.5 ET. AND /+.5 FT.
Tesf Hole Pre Seabed Prior fo Percotafien TesL
TEST PERFORHED BY: AH ' I, MICHAEL E. ANDERSON, CERTIFY THAT THIS TEST WAS PERFORPIED IN ACCORDANEL
--WiTH ALL STATE AND MUNICIPAL GUIDELINES ON THIS DATE: 11/19/200&
PROJECT #:
PERFORMED FOR:
MUNICIPALITY OF ANCHORAGE
DEVELOPMENT SERVICES DEPARTMENT
4700 SOUTH BRAGAW STREET, ANCHORAGE, AKggEtg-6650
SOILS LOG -PERCOLATION TEST
Joe Burnham
DATE PERFORMED: 10/29/04`
LEGAL DESCRIPTION: Erandeur Subdivisioo
2
18
COMMENTS:
TEST HOLE
Organic Ma,erial
OO/OL
Sitfy 6ravel
GM
.:20% SiLl- (Esl.)
Bedrock ¢ 5'
9 SLOPE
SITE PLAN
SEE SITE PLAN AND
SUBDIVISION £ONTOOR HAP
WAS GROUNDWATER
ENCOUNTERED?
IF YES, WHAT DEPTH?
DEPTH OF WATER
AFTER MONITORINO:
DATE:
No S
L
0
P
None
E
11/12/04,
' GROSS NET DEPTH OF NET
READING DATE
TIME TIME WATER DROP
I I0/31 10:18 73"
2 10:28 10 4.5" 3"
3 10:29 7.25"
4` 10:39 10 4`.75!' 2.5"
S 10:4`0 7.13"
'6 10:50 10 4,63" 2.5"
PERC RATE: 4` MIN./INCH PERC. HOLE DIAMETER: 6"
TEST RUN BETWEEN 3 FT. AND 4` FT,
Tesf Hote Pre Soaked Prior fo Percotafion Tesf.
TEST PERFORMED BY: A~H
{, MICHAEL E. ANDERSON, CERTIFY THAT THIS TEST WAS PERFORMED IN ACCORDANCE
WITH ALL STATE AND MUNICIPAL GUIDELINES ON THIS DATE: 11/19/2004`
PROJECT #:
PERFORMED FOR:
MUNICIPALITY OF ANCHORAGE
DEVELOPMENT SERVICES DEPARTHENT
~700 SOUTH BRAGAW STREET, ANCHORAGE, AKgg519:5550
SOILS LOG -PERCOLATION TEST
Joe Burnham
DATE PERFORMED: 10/28/o4`
LEGAL DESCRIPTION: Grandeur Subdivision
2
$
5
6
7
8
g
~8
COMMENTS:
TEST HOLE
Organic Haferial
06/OL
SiLly Brevet
GM
OLive/Damp
Bedrock
10 SLOPE
SITE PLAN
SEE SITE PLAN AND
SUBDIVISION CONTOUR MAP
WAS GROUNDWATER
ENCOUNTERED?
IF YES, WHAT DEPTH?
DEPTH OF WATE~
AFTER MONITORING:
DATE:
No S
L
O
P
None
E
11/12/0/+
GROSS NET DEPTH OF NET
READING DATE
. TIME TIME WATER DROP
1 10/31 3:2¢ 7.25"
2 3:50 30 3.25" 4`"
3 3:Sl 7.38"
4` 4`:21 30 3.63" 3.75"
5 4`:22 7.25"
6 4-:52 - 30 3.5" 3,75"
PERC RATE: 8 MIN./INCH PENC. HOLE DIAMETER:
TEST RUN BETWEEN 3 FT. AND &' FT.
Test- Hote Pre Soaked Prior fo Percolation Tesf.
TEST PERFORMED BY: A._U.H
I, MICHAEL E. ANDERSON, CERTIFY THAT THIS TEST WAS PERFORMED IN ACCORDANCE
WITH ALL STATE AND MUNICIPAL GUIDELINES ON THIS DATE: 11/19/2004,