HomeMy WebLinkAboutLABATE LT 1A
Departmer~ ~of Health & Environmenta~ ~otection
Environmental Health Division
Case Review Worksheet
Case Number t Date Received" ~ Comments Due By
S-6852 / March 7, 1983 t March 23, 1983
Subdivision or Project Title:
Lots iA, 6A La Bate Subdivision
(~l~Public water available
( ) Communlty water available
~)~Public sewer available
Comments:
TO
DOWL ENGINEERS
4040 "B" Street
· ANCHORAGE, ALASKA 995~)3
(907) 562-2000
Telecopier Phone (907) 563-3953
WE ARE SENDING YOU [] Attached [] Under separate cover wa the following items:
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COPIES DATE NO. DESCRIPTION
So,c..
THESE ARE TRANSMITTED as checked below:
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[] Approved as noted
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DOWL Engineers
Phone (907) 278-1551 ( Telecopier (907) 272-5742 )
March 11, 1982
W.O. ~D15668
Grid ~2122
Mr. Greg Jones
DOWL ENGINEERS
4040 "B" Street
Anchorage, Alaska
99505
Subject:
Subsurface Investigation for Suitabi ity of On-Site
Sewage Disposal, Kincaid Park Condominiums,
Pargetter Property (within SE~, SW%, SW%, Sec. 4,
T12N, R4W, S.M.)
Dear G~eg:
Transmitted herein are the percolation test results and soil
logs for the test holes drilled on the subject parcel. A
location sketch for the test hotes is attached.
Test holes were dril ed on the subject lots on March 3 and 4,
1982. The test holes were located in the field at the approxi-
mate locations shown on the attached location sketch. The
drilling was done using a Nodwell mounted, ~obile b-61 dril
fitted with a sotid flight auger. The dril'l rig is owned and
operated by Denali Drilling, Inc. The drilling was superv'sed
and the test holes logged by Mr. Dave Paul, technician with
Alaska Testlab. Grag samples were obtained at five-foot inter-
vals in each test hole. They were visua ly classified in the
field, and sealed in plastic bags to preserve the natura mois-
ture content. In the laboratory, all samples were again classi-
fied, and moisture contents were determined.
The soils encountered at this site were fairly consistent. A
representative soil profile can be described as a surface
organic layer about 0.5 feet thick, which is underlain by a
brown Silt to Sandy Si t layer to a depth of 5 to 6 feet.
Below the silt is a brown Silty fine to medium Sand, with
about 10% to 40% silt. No ground water was observed whi e
drilling~ although some damp zones were noted. Ground water
should not be of concern to disposal systems, as it is ex-
pected to be over ~00 feet below the surface.
Eight-inch diameter test holes were drilled to a depth of 1G
feet. A perforated PVC pipe was inserted in each hole to
preserve an open hole for performing the perc01ation test and
onltorlng water levels. The percolation test was performed
Lewis E. Dickinson Maurice P. Oswald Kenneth B. Walch Melvin R. Nichols
DOWL ENGINEERS March 11, 1982
Hr. Greg Jones Page 2
by filling the hole with water and allowing it to soak for' 24
hours, then refilling the holes, and recording the water level
at 10-minute intervals over a one hour period. The percola-
tion rate was determined from the drop in water level measured
over the last 10 minutes or the slowest 20 minutes of
The following percolation rates were obtained;
Measured Recommended
Percolation Rate Percolation Rate
Test Hole (minutes/inch) (minutes/inch)
1 4.7 8.0
2 4.0 8.0
3 1.5 3.0
4 1.7 5.0
5 3.0 5.0
6 1.9 5.0
7 4.0 8.0
8 5.7 8.0
the test.
These rates are applicable to sewage disposal systems designed
according to the Manual of Septic yank Practice, U. S. Public
Health Service.
We recommend that the more conservative rates be used for design
of disposa systems for two reasons: 1) The soits encountered
have a high si t content, and will not likely retain the short-
term, relatively high absorption rates over the life of the
system which were measured in these'tests; and 2) the majority
of the percolation 'rates were obtained when water levels in
the holes were 4 to 6 feet below the surface, and had apparently
not yet equalized at a constant, minimum rate which is typically-
observed.
If you have any questions regarding this investigation, please
feel free to call.
Very truly yours,
DOWL ENGINEERS
Carl A. Bassler
Geotechnical Engineer
Mr. Greg Jones
March 11,
Page 3
1982
APproved by:
CAB:mb2Y
Melvin R. Nichols,
Partner
P. Eo
Test Hole
Table A
WO #D13668
Date: 3/3/82
Logged by: DP
Depth in Feet
From To
0 0.6
0.6 2.5
2.5 16.0
Soil Description
Organics
F4, Light tan Silt, (ML)
F3/F4, Brown silty fine Sand, (SM), 30%
to 50% silt, moist, medium dense
Grades less silty (±25%) below 11 feet.
Some gravel at'8.0 feet and 11.5 feet.
Perc rate = 4.5 minutes/inch
Recommended perc rate = 8.0 minutes/inch
Bottom of Test Hole:
Frost Line:
Free Water Level:
16.0 Ft.
2.5 Ft.
None observed.
Sa. Type of
No. Depth % M Sample Group Unified
1 5' 12.3
2 10' 16.6
3 15' 15.3
Remarks: 1.
3.
4.
5.
6.
G A SM
G B SM/ML
G C SM
Type of Sample, G=Grab, SPT = Standard Penetration,
U = undisturbed.
Dry Strength, N=None, L=Low, M=Medium, H=High.
Group refers to similar material, this study only.
General Information, see Sheet 1.
Frost and Textural Classification, see Sheet 2.
Unified Classification, see Sheet 3.
Test Hole #2
TableA
WO #D13668
Date: 3/3/82
Logged by: DP
DePth in Feet
From To
0 0.5
0.5 2.5
2.5 5.5
5.5 16.0
Soil Description
Organics
F4, Light brown Silt, (ML), damp
F4, Brown silty fine Sand, (SM), 40% silt,
moist to damp, some gravel at 5.5 feet
F2, Brown silty fine-medium Sand, (SM),
±10% silt, moist, medium dense. Grades
more silty with some gravel by 15 feet,
1" maximum
Perc rate = 4.0 minutes/inch
Recommended perc rate = 8.0 minutes/inch
Bottom of Test Hole:
Frost Line:
Free Water Level:
16.0 Ft.
2.0 Ft.
None observed.
Sa.
No. Depth % M
Type of
Sample Group Unified
1 5' 12.5. G A ML/SM
2 10' 5.7 G D SP-SM
3 15' 9.3 G C SM
Remarks: 1.
at
Type of Sample, G=Grab, SPT = Standard Penetration,
U = undisturbed.
Dry Strength, N=None, L=Low, M=Medium, H=High.
Group refers to similar material, this study only.
General Information, see Sheet 1.
Frost and Textural Classification, see Sheet 2.
Unified Classification, see Sheet 3.
Test Hole #3
Table A
WO #D13668
Date: 3/3/82
Logged by: DP
Depth in Feet
From To
0 0.6
0.6 6.0
6.0 12.0
12.0 16.0
Soil Description
Organics
¥4, Light brown Silt, (ML), some fine sand,
moist to wet
F4, Brown silty fine Sand to sandy Silt,
moist, some gravel at 6.5' to 7.0'
NFS/F2, Brown Sand, (SP-SM), 5% to 15%
silt, damp, some gravel at 1600'
Perc rate = 1.5 minutes/inch
Recommended perc rate = 3.0 minutes/inch
Bottom of Test Hole:
Frost Line:
Free Water Level:
16.0 Ft.
2.5 Ft.
None observed.
Sa.
No. Depth
1 5'
2 10'
3 15:
Type of
% M Sample Group Unified
45.2 G E ML
15.4 G E SM/ML
9.6 G D SP-SM
Remarks: 1.
3.
4.
5.
6.
Type of Sample, G=Grab, SPT = Standard Penetration,
U = Undisturbed.
Dry Strength, N=None, L=Low, M=Medium, H=High.
Group refers to similar material, this study only.
General Information, see Sheet 1.
Frost and Textural Classification, see Sheet 2.
Unified Classification, see Sheet 3.
Test Hole #4
Table A
WO #D13668
Date: 3/4/82
Logged by: DP
Depth in Feet
From To
0 0.3
0.3 3.0
3.0 16.0
Soil Description
Topsoil
F4, Brown Silt, (ML), damp
F4, Brown fine sandy Silt, (ML), 30% to 40%
sand
More sandy below 8 feet~ wet from 9' to 13'
Perc rate = 1,7 minutes/inch
Recommended perc rate = 5.0 minutes/inch
Bottom of Test Hole:
Frost Line:
Free Water Level:
16.0 Ft.
2.5 Ft.
None observed.
Sa.
No. Depth
1 5'
2 10'
3 15'
Type of
% M Sample Group Unified
19.8 G E ML
26.1 G E ML/SM
19.9 G E ML/SM
Remarks: 1.
3.
4.
5.
6.
Type of Sample, G=Grab, SPT = Standard Penetration,
U = Undisturbed.
Dry Strength, N=None, L=Low, M=Medium, H=High.
Group refers to similar material, this study only.
General Information, see Sheet 1.
Frost and Textural Classification, see Sheet 2.
Unified Classification, see Sheet 3.
Test Hole ~5
Table A
WO #D13668
Date: 3/3/82
Logged by: DP
Depth in Feet
From To
0 0.5
0.5 5.5
5.5 13.0
13.0 16.0
Soil Description
Organics
F4, Light brown fine sandy Silt, (ML),
damp
F2/F4, Brown silty fine-medium Sand, (SM),
10% to 20% silt, moist
F4, Brown sandy Silt, (ML)~ 20% to 40%
sand, wet
Perc rate = 3.0 minutes/inch
Recommended perc rate = 5.0 minutes/inch
Bottom of Test Hole:
Frost Line:
Free Water Level:
16.0 F't.
3.0 Ft.
None observed.
Sa.
No. Depth
1 5'
2 10'
3 15'
Remarks: .1.
3.
4.
5.
6.
Type of
% M Sample Group -Unified
25.1 G E ML
10.0 G D SM
18.3 G E ML
Type of Sample, G=Grab, SPT = Standard Penetration,
U = Undisturbed.
Dry Strength, N=None, L=Low, M=Medium, H=High.
Group refers to similar material, this study only.
General Information, see Sheet 1.
Frost and Textural Classification, see Sheet 2.
Unified Classification, see Sheet 3.
Test Hole #6
Table A
WO #D13668
Date: 3/3/82
Logged by: DP
Depth in Feet
From To
0 0.5
0.5 13.5
13.5 16.0
Bottom of Test Hole:
Frost Line:
Free Water Level:
Soil Description
Organics
F2/F4, Brown silty fine Sand, (SM), 30%
to 40% silt, moist, less~t by 10'.
Some gravel at 11'.
F4, Brown fine sandy Silt, (ML), 20% to
30% sand, damp.
Perc rate = 1.9 minutes/inch
Recommended perc rate = 5.0 minutes/inch
16.0 Ft.
2.0 Ft.
~None observed.
Sa.
No. Depth
1 5'
2 10'
3 15'
.Type of
% M Sample Group Unified
17.3 G E SM
14.0 G C/D SM
20.3 G E ML
Remarks: 1.
e
3.
4.
5.
6.
Type of Sample, G=Grab, SPT = Standard Penetratlon~
U = undisturbed.
Dry Strength, N=None, L=Low, M=Medium, H=High.
Group refers to similar material, this study only.
General Information, see Sheet 1.
Frost and Textural Classification, see Sheet 2.
Unified Classification, see Sheet 3.
Test Hole #7
Table A
WO #D13668
Date: 3/3/82
Logged by: DP
Depth in Feet
From To
0 0.5
0.5 6.0
6.0 16.0
Soil Description
Organics
F4, Light brown sandy Silt,
sand, moist
(ML) , +40% fine
F4, Brown silty fine Sand, (SM), +30% silt.
More silty, damp by 15'.
Perc rate = 4.0 minutes/inch
Recommended perc rate = 8.0 minutes/inch
Bottom of Test Hole:
Frost Line:
Free Water Level:
16.0 Ft.
2.0 Ft.
None observed.
Sa.
No. Depth
1 5'
2 10'
3 15'
Type of
% M Sample Group Unified
10.6 G A ML
7.8 G D SM
13.8 G E SM/ML
Remarks: 1.
3.
4.
5.
6.
Type of Sample, G=Grab, SPT = Standard Penetration,
U = Undisturbed.
Dry Strength, N=None, L=Low, M=Medium, H=High-
Group refers to similar material, this study only.
General Information, see Sheet 1.
Frbst and Textural Classification, see Sheet 2.
Unified Classification, see Sheet 3.
Test Hole #8
Table A
WO #D13668
Date: 3/3/82
Logged by: DP
Depth in Feet
From To
0 0.5
0.5 3.0
3.0 6.0
6.0 16.0
Bottom of Test Hole:
Frost Line:
Free Water Level:
Soil Description
Organics
F4, Brown Silt, (ML), moist
F4, Brown sandy Silt, (ML), 30%
sand, damp
F4, Brown silty fine Sand, (SM),
silt, moist. Some gravel at 7',
silty by 15'
Perc rate = 5.7 minutes/inch
Recommended perc rate =
16.0 Ft.
2.5 Ft.
None observed°
to 40%
±35%
more
8.0 minutes/inch
Sa.
No. Depth
1 5'
2 10'
3 15'
Type of
% M Sample Group Unified
14.9 G G ML
12.0 G D SM
19.7 G D SM/ML
Remarks: 1.
'2.
3o
4.
5.
6.
Type of Sample, G=Grab, SPT = Standard Penetration~
U = undisturbed.
Dry Strength, N=None, L=Low, M=Medium, H=High.
Group refers to similar material, this study only.
General Information, see Sheet 1.
Frost and Textural Classification, see Sheet 2.
Unified Classification, see~Sheet 3.
Test Hole #9
Table A
WO #D13668
Date: 3/4/82
Logged by: DP
Depth in Feet
From To
0 1.0
1.0 6.0
6.0 6.5
Soil Description
Brown Peat, (Pt)
F4, Brown Silt and Organics, ML-OL)
F4, Brown sandy Silt, (ML), damp
Bottom of Test Hole:
Frost Line:
Free Water Level:
6.5 Fto
1.5 Fto
None observed.
Remarks:
o
3.
4.
5,
6.
Type of Sample, G=Grab, SPT = Standard Penetration,
U = Undisturbed.
Dry Strength, N=None, L=Low, M=Medium, H=High.
Group refers to similar material, this study only.
General Information, see Sheet 1.
Frost and Textural Classification, see Sheet 2.
Unified Classification, see Sheet 3.
Test Hole Log - Description Guide
The logs often include the following items:
Depth Interval - usually shown to 0.1 foot, within that zone no
significant change in soil type was observed through drill action, direct
observation or sampling.
Frost Classification - NFS. Fl. F2. F3. F4. see "Soil Classification
Chart"
Texture of Soil - An eugineermg classification of the soils by particle
size and proportion, see "Soil Classification Chart". note the
proportions are approximate and modifications to the soil group due tu
stratificanon, inclusions and changes m properties are included.
dam?, moisture forms portion of color, less than plastic limit.
sand. (The moisture content is further definedby reference to Pl.
LW, NP. M% or dilatency.)
maxtutes with or without ~ fine fraction, derived from drilling action
and/or sample data: usually described as: very loose, loose, medium
Stiffness - refers to more-or-less cohesive soils and fine grained silts of
the clay-silt groups. Derived from drill action and/or sample data. Very
soft, soft, stiff, very stiff and hard are commonly used terms.
Particle size - The largest particle recovered by the split spoon ts
1-3/8", Shelby tube 3". auger flights (minute-man) 2", Auger flights
lB-50 hollow steml 6"-8% Larger parucles are described indirectly by
action of the drilliug and are referred to as cobbles, 3" to 8'. or
boulders 8"% Therefore when' reviewing the gradation sheets, if any,
the description on the hole log must be considered for an'indication of
larger particles,
Unified Soil Classification - This is a two letter code. See Unified
Classification sheet for ftuther definition. In some cases AASHO and/or
FAA soil classifications may be shown as well as the unified.
Atterberg Limits - useful for fine grained and other plastic soils,
PI; natural moisture content believed to be le~s than plastic limit
Pi+; natural moisture content believed to be between plastic and liquid
l~mits
L.~.~; rialto, al moisture content believed to be greater than liquid limit
N~P; not, plastic, useful as a modifying description of ~ome silty
Dilatency - is the ability of water to migrate to the surfgce of a
saturated or nearly saturated *od sample when vibrated orjohed - used
as sn aid to determine if a fine grained soil is a slightly or non,pis*tic
silt or a volcanic ash.
Rock flour - finely ground soil that is not plastic but otherwise appears
similar to a clayey silt.
Organic Content - usually described as Peat. PT. sometimes includes
of ail organic. - as Peat. This may include tundra muskeg and bog
material.
usually occuring below a peat depom.
Amorphus peat -. organic particles nearly or fully disintegrated.
Fibrous Peat - orgamc particles more-or-less intact.
Bottom of Testhole - includes last san:pie interval.
Frost Line - seasonal frost depth as described by drilling action and/or
samples at the time of drilling.
Frozen Ground - other than frost line, described by samples, usnaily
includes description of ice content, often will include modified Unified
Classification for ['r6zen soils - this is a special case related to
permafrost studies.
Free Water Level - The free water level noted during drilling. This is
not necessarily the static water table at the time of drilling or at other
seasons. Static water table determination in other than very permeable
soils requires observation wells or piezometer installations, used only m
special cases.
Blow/6" - The number of blows of a 140 weight free falling ~,0" to
advance a 2" split spoon 6"i the number of b!ows for a 12" advance is.
by definition, thc standard penettauon
,d% - natural moisture content of the soil sample, usually not
pe~r ormed on clean sandsor gravels below the water table,
Type of Sample -
.S_P, refers t9 2" split spoon driven into the soil by 140 pound
weight, a disturbed sample,
~, thin wall tube, "Shelby" used to obtain undisturbed samples
of line grained soil,
G, "grab" disturbed sample from auger flights or wall of trench,
.~, cut sample, undisturbed sample from wall of trench,
pry Strength - a useful indicator of a soil's clayey fraction, N=None,
L=Low, M=Medium, H=High
Group - Tile samples are placed into apparently similar, groups based
oil color and texture and are arbitrarily assigned a grnup.etter. Further
disturbed tests including Atterberg Limits, grain size, moisture<lensity
relationship, etc. may be performed on the group anti are asstlmed to
reflect the general distruhed characteristics of the soils assigned to the
group. This is an impor:ant phase of the soil analysis and is used to
TEXTURAL
SOIL CLASSIFICATION
CHART
?
GRAVEL ~0°/o
GRAVEL
0 I0 20 ' 30 40 50 60 70 80 '90
GRAVEL (+ :1:1: 4 SCREEN) % BY WEIGHT
I00
FROST CLASSIFICATION SYSTEM
NO~NFROST SUSCEPTIBLE SOILS ARE INORGANIC SOILS CONTAINING LESS THAN 3% FINER THAN 0,02 mm.
GROUPS OF FROST-SUSCEPTIBLE SOILS:
FI GRAVELLY SOILS CONTAINING BETWEEN 3 AND 20% FINER THAN 0,02 mm.
F2 SANDY SOILS CONTAINING BETWEEN 3 AND 15% FINER THAN 0,02 mm.
F3 a. GRAVELLY SOILS CONTAINING MORE THAN 20% FINERTHAN0,02 nlm. AND SANDY SOILS
· ' (EXCEPT FINE SILTY, SANDS) CONTAINING MORE THAN 15% FINER THAN 0.02 mm
b, CLAYS WlTFI PLASTICITY INDEXES OF MORE THAN 12. EXCEPT VARVED CLAYS.
F4 a. ALL SILTS INCLUDING SANDY SILTS.
FINE SILTY SANDS CONTAINING MORE THAN 15% FINER THAN 0,02 mm.
c, LEAN CLAYS WITH PLASTICITY INDEXES OF LESS THAN 12.
d. VARVED CLAYS,
(3 V O~J
QI~ONI>t
//
103 33S