HomeMy WebLinkAboutFISCHER S-10731Fi
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May 15, 2001
Municipality of Anchorage
Building Safety Division
On-Site Water and Wastewater Program
4700 S. Bragaw Street
Anchorage, AK 99507
Attention: Jim Cross, P.E.
Su~e~:
Lots 2A, 2B, 2C, Block 3, Fischer Subdivision
S-10731
Septic System Reserve Areas
Dear Jim:
In late January we completed a geotechnical investigation and septic system
feasibility study on Lot 2, Block 2, Fischer Subdivision. The lot is currently being
subdivided into 3 lots each with its own on site septic system and water well. Our
directive was to locate suitable areas on each lot for the construction of on site
septic systems capable of meeting the requirements of the Municipal Ordinance
for the treatment of domestic effluent from homes to be constructed in the
subdivision.
Excavation for the test holes was completed on January 24, 2001. Test holes
were dug to depths approaching 15' utilizing a track mounted backhoe with an
experienced operator. ^ soils technician was on site to log the test holes and
perform the field testing. A monitor tube was placed in each hole to monitor the
groundwater levels over the ensuing runoff pedod. Percolation benches were
then constructed at vadous depths in the holes, but pdmadly between 5' and 7'
below the odginal ground 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 matedal encountered in the test holes was faidy uniform
throughout the site and was pdmadly composed of well to poody graded sands
and gravels with silt contents ranging from 5% to 15%. The percolation rate of
Lots 2A, 2B, 2C, Block 2, Fischer Subdivision
Septic System Feasibility
Page Two
May 15, 2001
materials encountered was uniform and ranged between I and 2 minutes per
inch. No groundwater was encountered in the test holes and none was noted
throughout the monitoring pedod. Conditions encountered on the parcel are
excellent for the construction of septic systems and the treatment of septic
effluent.
The surface topography of the tract is fairly fiat with only slight grades from south
to north. No slopes on the lot exceed 25% and setback requirements are not a
factor. The Municipal Ordinance governing septic systems requires a minimum
of 10,000 square feet of area be available for the odginal and two replacement
onsite wastewater disposal systems. The square footage is based on the soils
absorptive characteristics of less than 5 minutes to absorb an inch of water.
More than sufficient area is available on each lot. The reserve area for each lot
is shown on the attached documentation.
Proposed well locations for the lots in the subdivision are shown on the attached
drawing. We have also shown the wells on the adjacent lots. No surface water
was noted dudng our study. The Municipal Ordinance requires that septic
systems cannot be constructed closer than 100' from any surface water.
Test holes were located in areas, which were assumed to be the pdmary location
for the new septic systems. These locations are shown on the attached map,
which defines the area of the subsurface study. Please review the attached data
and advise if you have any questions.
Sincerely,
Michael E. Anderson, P.E.
Attachments
JA4
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SELDON
JA2
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IQ° Ut# I'~t
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SPRUCE. CR~'K Circle
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299,71
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2B
0% - 2%
2A
.~fN89'53'45"1 -1316.t4;. F,etd HVt. ~. '
1Q'Tde · C~A C~ml ~-
I
NOTE:
LOTS 2A, 2B, 2C, BLOCK 3,
FISCHER SUBDIVISION
SCALE 1" = 100'
Ground Surface Slopes on This Property <<25%.
lC
7
60.22
I
I
5
S8~'55'50'l 3
- 438't ' .:7
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SELDON
CIRCLE
I
Septic
Exist g Well Reserve
Area
® ~ >~o,ooo
Lot lB
Reserve Area
· >i0,000 SF
TH6'
Exi
Well
3B7A
T~"4
SPRUCE CREEK
Proposed
Well
Septic
Reserve
iArea
>10,000
~ TH1
~F
Exis .ng
CIRCLE
Exi: :lng
F
E: :tsting _ ._
EAST 104TH
SEPTIC SYSTEM RESERVE,,~,~.;,.~o,," ~ ~ ~ ~"~..~'~"~c~. ~'~3~'~"~'~ .-' :"-:'3 ~
~E ~ '4.~" ."-~'"
Performed For: paul Palmer
Legal Description:
Munici~li~ of Anchorage ¢.~~.
Depa~ment of H~lth & Human Se~ices
825 L Strut, Anchorage, AK 99502~650
Date Pedorm~:
Lots ~. 2B. 2C. Bilk 3. Fischer Su~ivision
SLOPE SITE P~N
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
OG/PT
TESTHOLE NO. I
Sandy
Well Graded
Gravel
See Site Plan
GW
Was Groundwater
Encountered? No S
If Yes, What Depth? L
Depth to Water O
After Monitoring None P
Date: 1131101 E
East to West (~ 0% - 2%
Bottom of
Hole
Reading Date Gross Net Depth To Net
Time Time Water Drop
I 24-Jan 10:50 2"
2 11:00 10 12" 10"
3 11:01 2"
4 11:11 10 12" 10"
5 11:12 2"
6 11:22 10 12" 10"
Parc. Rate: I Min./Inch Parc. Hole Diameter: 6"
Test Run Between 5 Ft. and 6 Ft.
Comments: Percolation Cavity Presoaked Prior to Testing.
Performed By: ~ I, Michael E. Anderson Certify That This Test Was Performed
In Accordance With All State and Municipal Guidelines In Effect On This Date: 1/25/01
Performed For: paul Palmer
Legal Description:
/'
Municipality of Anchorage ~0,.;. ~.~,...,~ ............. : .... ~; -
Department of Health & Human Services ~. ~j'. M~¢.~E[ E A~S~; ,"
825 L Street, Anchorage, AK 99502-0650 ~ ~'.. C~- 4381
· ,/~, ..
SOILS LOG - PERCOLATION TEST #,.~.~., ...... ,,,,~
~j· P£OrE~'~~'~
Date Performed: %~'~2~101
Lots Z~. 2B. 212. RIock 3. Fischer Subdi¥i~ion
SLOPE SITE PLAN
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
OG/PT
TESTHOLE NO. 2
Well Graded
Gravel
See Site Plan
GW
Was Groundwater
Encountered? No S
If Yes, What Depth? L
Depth to Water O
After Monitoring None P
Date: 1/31101 E
I;;.~t to West (~) 0% - 2%
Bottom of
Hole
Reading Date Gross Net Depth To Net
Time Time Water Drop
I 24-Jan 10:55 2.5"
2 11:05 10 12" 9.5"
3 11:06 2"
4 11:16 10 12" 10"
5 11:17 2"
6 11:27 10 12" 10"
Perc. Rate: I Min./Inch Perc. Hole Diameter: 6"
Test Run Between 5.5 Ft. and 6.5 Ft.
Comments: Percolation Cavity Presoaked Prior to Testing.
Performed By: ~T. Jl]3_J~Ji]3Jz~ug~ I, Michael E. Anderson Certify That This Test Was Performed
In Accordance With All State and Municipal Guidelines In Effect On This Date: 1/25/01
Municipality
of
Anchorage
$ ~,~. MICHAEL E ,','U',[~' ,; ',
Development Services Department
.~ ,..,:., . .
4700 South Bragaw, Anchorage, AK 99507 ~.... ..
Date Performed; 1/24/01
Performed For: paul Palmer
Legal Description: Lot 2. Block 3. Fischer Subdivision
SLOPE SITE PLAN
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
OG/PT
TESTHOLE NO. 3
Well Graded
Gravel
GW
See Site Plan
Was Groundwater
Encountered?
If Yes, What Depth?
Well Graded Depth to Water
Sand After Monitoring
Date:
SW
Bottom of
Hole
No S
L Fa~t to West @ 0% - 2%
O
None P
4/1101 E
Reading Date Gross Net Depth To Net
Time Time Water Drop
I 24-Jan 1:05 2"
2 1:15 10 12"(Dry) 10"
3 1:16 2"
4 1:26 10 12"(Dry) 10"
5 1:27 2"
6 1:37 10 12"(D~) 10"
Perc. Rate: 1 Min./Inch Perc. Hole Diameter: 6"
Test Run Between 5.5 Ft. and 6.5 Ft.
Comments: Percolation Cavity Presoaked Prior to Testing.
Performed By: ~T. iELIC~aJ3B3Ug~ I, Michael E. Anderson Certify That This Test Was Performed
In Accordance With All State and Municipal Guidelines In Effect On This Date: 4/1101
Municipality of Anchorage .........
Development Services Department ~ ~.~'. MICHAEL E. A';:~[~SC~' ~'
I. Cu~. CE - 43E;11 ." ..;;
4700 South Bragaw, Anchorage, AK 99507 ~,~..~.. ..'.'..;..
SOILS LOG - PERCOLATION TEST ~. /~ '- ........' ',..-
Date Performed: t ·,~1~2~1~ 1
Performed For: paul Palmer
Legal Description: Lot 2. Block 3. Fischer Subdivision
SLOPE SITE PLAN
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
OG/PT
TESTHOLE NO. 4
Well Graded
Gravel
GW
See Site Plan
Was Groundwater
Encountered? No
If Yes, What Depth?
Well Graded Depth to Water
Sand After Monitoring None
Date: 4/1101
SW
Bottom of
Hole
S
L
O
P
E
Fast to West ~_ 0% - 2%
Reading Date Gross Net Depth To Net
'Time Time Water Drop
1 24-Jan 1:00 2"
2 1:10 10 12"(Dry) 10"
3 1:11 2"
4 1:21 10 12"(Dry) 10"
5 1:22 2"
6 1:32 10 12"(Dry) 10"
Perc. Rate: 1 Min./Inch Perc. Hole Diameter: 6"
Test Run Between 6.5 Ft. and 7.5 Ft.
Comments: Percolation Cavity Presoaked Pdor to Testing.
Performed By: ~ I, Michael E. Anderson Certify That This Test Was Performed
In Accordance With All State and Municipal Guidelines In Effect On This Date: 4/1101
Municipality of Anchorage
Department of Health & Human Services
825 L Street, Anchorage, AK 99502-0650
SOILS LOG - PERCOLATION TEST
Performed For: paul palmer
Legal Description: Lots 2A. 2B. 2C. Block 3. Fischer Subdivision
;LOPE
I OG/PT
3
4
5
TESTHOLE NO. 5
Well Graded
Gravel
6 GW
9
10
11
7 Slightly
Compacted
8
Was Groundwater
Encountered? No
If Yes, What Depth?
Depth to Water
After Monitoring None
Date: 1/31101
SITE PLAN
Sea Site Plan
S
L
O
P
E
East to West (~) 0% - 2%
12
13
14
15
16
17
18
Well Graded
Sand
GW
Bottom of
Hole
Reading Date Gross Net Depth To Net
Time Time Water Drop
I 24-Jan 1:40 4"
2 1:50 10 12" 8"
3 1:51 4"
4 2:01 10 11.5" 7.5"
5 2:02 4"
6 2:12 10 11.5" 7.5"
19
Perc. Rate: 1.3 Min./Inch Perc. Hole Diameter: 6"
Test Run Between 6.5 Ft, and 7.5 Ft.
Comments: Percolation Cavity Presoaked Prior to Testing.
Performed By: ~T_iI:]3_F~]3J3[QUg~ I, Michael E. Anderson Certify That This Test Was Performed
In Accordance With All State and Municipal Guidelines In Effect On This Date: 1/25/01
Performed For: Paul Palmer
Legal Description:
Municipality of Anchorage ~.¢.;~.
-~!,:MICH~L E.
Depn~ment of Henlth& Humnn S~i~ ~'~.~".
825LsoiLsStr.t,L~Anchorage,. PERCO~TIoNAK .502~650
Date ~enorm~:
Lots ~. 2B. 2C. Bilk 3. Fischer Su~ivision
SLOPE SITE P~N
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
OG~T
TESTHOLE NO. 6
Well Graded
Gravel
GW
Slightly
Compacted
See Site Plan
Was Groundwater
Encountered? No S
If Yes, What Depth? L
Depth to Water O
After Monitoring None P
Date: 1/31101 E
East to West ~ 0% - 2%
Well Graded
Sand
GW
Bottom of
Hole
Reading Date Gross Net Depth To Net
Time Time Water Drop
I 24-Jan 1:45 3"
2 1:55 10 12" 9"
3 1:56 3"
4 2:06 10 12" 9"
5 2:07 3"
6 2:17 10 12" 9"
Perc. Rate: 1.1 Min./Inch Perc. Hole Diameter: 6"
Test Run Between 6.5 Ft. and 7.5 Ft.
Comments: Percolation Cavity Presoaked Prior to Testing.
Performed By: ~ I, Michael E. Anderson Certify That This Test Was Performed
In Accordance With All State and Municipal Guidelines In Effect On This Date: 1/25/01
May15,2001
Municipality of Anchorage
Building Safety Division
On-Site Water and Wastewater Program
4700 S. Bragaw Street
Anchorage, AK 99507
Attention: Jim Cross, P.E.
Subject:
Lots 2A, 2B, 2C, Block 3, Fischer Subdivision
S-10731
Water Availability Study
Dear Jim:
We have studied the wells on the lots surrounding Lot 2, Block 3, Fischer Subdivision in
an attempt to predict the availability of water for private use on the proposed three-lot
subdivision. The attached site plan shows the location of the adjacent wells along with
their respective 100' protective radii. The plan also shows the proposed locations for
the wells to be placed on this subdivision. In general, water availability in the
neighborhood is more than adequate and the addition of three more wells should have
little impact on future water supply.
The wells located immediately to the east of this property on Lots 4, 5 and 6 Dav-Dor
Subdivision are very shallow and range in depths from 40' to 60'. Casing is extended
full depth of the wells. Production rates are very good and range from 7 to 9 gallons per
minute. Flow tests performed in the past on these wells vedfy these production rates
originally noted on the well logs. The static water level in the wells ranges from 15' to
24' below the surface. Water appears to be plentiful in this area.
The well on Lot lB, Block 2, Fischer Subdivision immediately north of the subject parcel
is 180' deep and cased to a depth of 168'. A flow test on this well indicated a
production rate of 8.5 gallons per minute and a static water level of 14.8'. Similar
conditions to the wells on the eastem boundary, but the well is much deeper.
The wells on the western boundary of the property in Lot I of Fischer Subdivision are
deeper and range from 250' to 260' in depth and are cased in excess of 40' below the
surface. Well logs are not available for these lots as the wells were apparently placed
many years ago. The static water level in these wells is deeper at 238' to 250'. The
production rates are still very good and range between 4 and 7.2 gallons per minute.
In every case the production rates of the wells surrounding this proposed subdivision
are very good and well in excess of the Municipal requirement of .108 gallons per
Lots 2A, 2B, 2C, Block 2, Fischer Subdivision
Water Availability Study
May 15, 2000
Page 2
minute. Based on our research it is our conclusion that the wells to be constructed on
proposed Lots ?..A, 2B, and 2C, Block 2, Fischer Subdivision will be fairly shallow and
probably less than 100' in depth. Production rates should be in excess of 4 gallons per
minute. Attached are copies of the well logs for your use and a location map showing
the proximity of these wells to the proposed subdivision. Please review this data and
let me know if additional information is required to complete your analysis.
Sincerely,
Michael E. Anderson, P.E.
Attachments