HomeMy WebLinkAboutPM 12023 Percolation Report 2809 Unicorn Road, Suite 103
Bakersfield, California 93308
(661) 393‐9711 Office
(661) 393‐9710 Fax
SAN JOSE ▪ STOCKTON ▪ FRESNO ▪ BAKERSFIELD ▪ RANCHO CUCAMONGA
DALLAS, TX ▪ DENVER, CO ▪ CHARLESTON, SC
November 11, 2016 Project No. 2-616-0915
2-212-0480
Mr. Jack Brey Phone: (661)379-8377
Beech A/C Properties, LLC
c/o JB Consulting Services LLC Email: jbrey@bak.rr.com
9519 Lake Superior Drive
Bakersfield, CA 93312
SUBJECT: PERCOLATION TEST RESULTS
PROPOSED MCCUTCHEN & RELIANCE COMMERCIAL DEVELOPMENT
6900 MCCUTCHEN ROAD
BAKERSFIELD, CALIFORNIA
Dear Mr. Brey:
SALEM Engineering Group, Inc. (SALEM) is pleased to submit the Percolation Test Results performed on the ten
proposed retention basins to be constructed in conjunction with Phase I of the subject site development located in
Bakersfield, California.
1.0 PERCOLATION TESTING
Twenty percolation tests were performed on the ten proposed retention basins that are to be constructed in
conjunction with Phase I of the site development. Two percolation tests were performed at each of the ten proposed
basins. The percolation tests performed at the site were conducted within the Silty Sand unit that directly underlies
the upper approximately 3 to 5 foot thick Sandy Silt unit that essentially caps the site. The uppermost Sandy Silt
unit was previously determined have absorption rates that were not acceptable for the proposed basin design
requirements. Percolation testing was performed from October 27th through October 31st 2016.
In order to determine the overall percolation rates for the Silty Sand unit that exists at an intermediate depth
beneath each of the proposed retention basins, one shallow and one deep percolation test was performed. The
shallow percolation tests were performed directly below the upper Sandy Silt (approximately 5 to 6 feet below the
existing surface grade), and the deep percolation tests were performed near the bottom of the currently proposed
removal depth of 11 feet (approximately 9 to 10 feet below the existing surface grade).
The percolation test locations are shown on Figure 1. A 1 cubic foot hole was excavated at the approximate depths
mentioned above. The 1 cubic foot holes were thoroughly pre-soaked for a minimum of 24 hours prior to
conducting percolation testing. No water was found in any trenches after the 24 hours pre-soak, with the exception
of percolation tests P1A & P2A. P1A & P2A were shallow percolation tests that were partially excavated within
the upper Sandy Silt unit. After the pre-soak, the test holes were filled with six inches of water prior to conducting
Project Nos. 2‐616‐0915
2‐212‐0480
Page No. 2
percolation testing. Percolation tests were conducted for a minimum of four hours, or until a stabilized rate was
achieved (see attachments for the percolation test worksheets). The percolation test results are as follows:
TABLE 1 – PERCOLATION TEST SUMMARY
Test No. Depth
(feet)
Absorption
Rate
(gal/ft2/day)
Percolation
Rate
(min/inch*)
Soil Type
P-1A 5 <0.5 >360 Sandy Silt (ML)
P-1B 9 92 1.9 Silty Sand (SM)
P-2A 6 <0.5 >360 Sandy Silt (ML)
P-2B 11 51 3.5 Silty Sand (SM)
P-3A 6 3.5 52 Sandy Silt (ML)
P-3B 10 15.5 11.6 Silty Sand (SM)
P-4A 5.5 15.8 11.4 Silty Sand (SM)
P-4B 9 26 6.9 Silty Sand (SM)
P-5A 6 8.2 22 Silty Sand (SM)
P-5B 10 15.5 11.6 Silty Sand (SM)
P-6A 5.5 36 5.0 Silty Sand (SM)
P-6B 9 32 5.6 Silty Sand (SM)
P-7A 5 23 8.0 Silty Sand (SM)
P-7B 9 21 8.0 Silty Sand (SM)
P-8A 6 8.2 22 Silty Sand (SM)
P-8B 9 3.2 58 Silty Sand (SM)
P-9A 5 6.7 27 Silty Sand (SM)
P-9B 10 2.6 68 Silty Sand (SM)
P-10A 5 6.5 28 Silty Sand (SM)
P-10B 9 5.4 33 Silty Sand (SM)
* Equivalent percolation rate based on 6-inch diameter boring with 6-inches of water.
See explanation of this conversion in the appendices to this report.
Project Nos. 2‐616‐0915
2‐212‐0480
Page No. 3
As part of the percolation testing, each of the 10 test pits excavated at the subject site were logged by a Professional
Geologist from our office. The test pit logs (TP1 through TP10) with accompanying soil description are presented
as attachments to this report. The test pit logs numbering sequence correspond with the numbering sequence of the
percolation tests (i.e., the location of test pit TP1 is the same location as percolation tests P1A & P1B). The test pits
excavated at the subject site were each approximately 20 feet in overall length, 6-7 feet in width, and ranged from 8
to 10 feet in total depth below the original ground surface. No restrictive soil horizons were noted in any of the test
pits excavated at the site in conjunction with the percolation testing.
Based on design retention basin volumes, SALEM previously determined that a soil absorption rate below the
basins of at least 2 gal/ft2/day should allow them to drain within the maximum 7-day period. Review of the
percolation test results in Table 1 above shows that only the percolation tests that were conducted in the near-
surface silt unit failed to meet the minimum absorption rate. The remaining tests conducted below the upper silt
unit met and generally greatly exceeded the minimum. Only percolation tests P3-A, P8-B and P9-B (3.5, 3.2 and
2.6 gal/ft2/day, respectively) failed the target absorption rates based on a factor of safety of at least 2.
2.0 ALTERNATE BASIN DESIGN RECOMMENDATIONS
SALEM is aware that a City of Bakersfield-approved mitigation method for slow infiltration rates in stormwater
basins includes the removal and replacement of lower permeability materials at the design basin floor with
materials with sufficient permeability to meet the 7-day drain time requirement. Based on our above recent
percolation testing data, we believe that removal and replacement of all soils below the proposed stormwater basins
to a depth of 11 feet is unnecessary. Testing data shows that, once the upper, low-permeability silt unit is removed
(and slightly below that depth at the P3 location), the underlying native soils have a sufficient percolation capacity
to meet the 7-day drainage requirement.
As an alternative to the design recommendations in our 2015 geotechnical report, SALEM recommends the
following:
While conducting grading operations for the site, excavate and stockpile the sandy silt surficial soil from
the proposed basin areas to a depth that penetrates into the lower silty sand unit that, based on the data in
this report, has been proven to have an acceptable percolation rate.
At the building pad locations, continue overexcavation below that recommended in our geotechnical
report into the lower silty sand unit. Remove a sufficient amount of this silty sand/sand material to replace
the upper silt unit removed from the stormwater basins and stockpile these soils.
Place and compact the lower permeability soils removed from the basins into the building pad excavation
and bring to planned grade. Compact these soils per the recommendations in our geotechnical report.
Place and compact the stockpiled higher-permeability silty sand soil into the basin floor excavation areas
and bring to planned grade. The basin floor replacement soils should be placed in lifts, moisture
Project Nos. 2‐616‐0915
2‐212‐0480
Page No. 4
conditioned to near optimum moisture content, and compacted to between 90% to 92% relative
compaction.
SALEM personnel should conduct adequate testing and observations during building pad excavation and
replacement of the basin floors to ensure that material properties meet the intent of this alternative design
recommendation.
Following completion of basin floor replacement, one percolation test for each 4 to 5 basins should be
conducted to verify the alternative design absorption rates.
Respectfully submitted,
SALEM Engineering Group, Inc.
Neil McConnell, PG, CEG
Senior Engineering Geologist
PG 8417 / CEG 2528
Bruce E. Myers, PE, CEG
Senior Engineer / Eng. Geologist
PE 62067 / CEG 2102
Attachments
Figure 1 – Test Location Map
Logs of Percolation Test Excavations
Percolation Test Worksheets
Notes on Conversion of Absorption Rate to mpi
FI
G
U
R
E
1
Test Pit Log Soil Descriptions
6900 McCutchen Road, Bakersfield
TP1 0 – 5.5 (ft.) Alluvium: Dark to medium brown sandy SILT, pinhole porosity, massive, moist,
medium stiff.
5.5 – 8 (ft.) Light brown silty SAND, pinhole porosity, mostly massive with occasional faint
laminations, moist, medium dense to dense with depth.
TP2 0 – 5.5 (ft.) Alluvium: Dark to medium brown sandy SILT, pinhole porosity, massive, moist,
medium stiff.
5.5 – 10 (ft.) Light brown silty SAND, pinhole porosity, mostly massive with occasional faint
laminations, moist, medium dense to dense with depth.
TP3 0 – 5 (ft.) Alluvium: Dark to medium brown sandy SILT, pinhole porosity, massive, moist,
medium stiff.
5.5 – 9 (ft.) Light brown silty SAND, pinhole porosity, mostly massive with occasional faint
laminations, moist, medium dense to dense with depth.
TP4 0 – 3 (ft.) Alluvium: Dark to medium brown sandy SILT, pinhole porosity, massive, moist,
medium stiff.
3 – 5 (ft.) Medium brown silty SAND, pinhole porosity, massive, moist, medium dense.
5 – 8 (ft.) Light brown silty SAND, pinhole porosity, massive, moist, medium dense to dense
with depth.
TP5 0 – 3 (ft.) Alluvium: Dark to medium brown sandy SILT, pinhole porosity, massive, moist,
medium stiff.
3 – 9 (ft.) Light brown silty SAND, pinhole porosity, massive, moist, medium dense to dense
with depth.
TP6 0 – 4 (ft.) Alluvium: Dark to medium brown sandy SILT, pinhole porosity, massive, moist,
medium stiff.
4 – 8 (ft.) Light brown silty SAND, pinhole porosity, mostly massive with occasional faint
laminations, moist, medium dense to dense with depth.
TP7 0 – 3 (ft.) Alluvium: Dark to medium brown sandy SILT, pinhole porosity, massive, moist,
medium stiff.
3 – 8 (ft.) Light brown silty SAND, pinhole porosity, mostly massive with occasional faint
laminations, moist, medium dense to dense with depth.
TP8 0 – 3 (ft.) Alluvium: Dark to medium brown sandy SILT, pinhole porosity, massive, moist,
medium stiff.
3 – 8 (ft.) Light brown silty SAND, pinhole porosity, mostly massive with occasional faint
laminations, moist, medium dense to dense with depth.
TP9 0 – 3.5 (ft.) Alluvium: Dark to medium brown sandy SILT, pinhole porosity, massive, moist,
medium stiff.
3.5 – 9 (ft.) Light brown silty SAND, pinhole porosity, massive, moist, medium dense to dense
with depth.
TP10 0 – 3 (ft.) Alluvium: Dark to medium brown sandy SILT, pinhole porosity, massive, moist,
medium stiff.
3 – 8 (ft.) Light brown silty SAND, pinhole porosity, massive, moist, medium dense to dense
with depth.
Percolation Test Worksheet
Backhoe Pit Test
Project:Proposed Commercial Development Job No.:2-216-0915 Vol. in 1" Wtr Col. (in3):144.0
6900 McCutchen Road Date Excavated:
Bakersfield, CA Soil Classification:Hole Width:12 in.
Hole Length:12 in.
Test Hole No.:P1APresoaking Date:
Tested By:NMTest Date:Ref Pt Height-5 ft ##
Pit Floor Depth:5 ft.
Time
Start
Time
Finish
Depth of
Test
Hole (in)#
Refill-
Yes or
No
Elapsed
Time
(hrs:min)
Initial
Water
Level# (ft)
Final
Water
Level#
(in)
∆ Water
Level (in.)∆ Min.
Meas.
Perc Rate
(min/in)
6" Dia. x
6" Water
Equiv.
MPI:
Avg. Ht. of
Water
Column**
(in.)
Wetted
Surf. Area
of Column
(in2)
Absorp.
Rate
(gpd/ft2)
9:229:5212Y 0:306.006.000.0030#DIV/0!#DIV/0!6.04320.0
9:5210:2212N0:306.006.000.0030#DIV/0!#DIV/0!6.04320.0
10:2210:5212N0:306.006.000.0030#DIV/0!#DIV/0!6.04320.0
10:5211:2212N0:306.006.000.0030#DIV/0!#DIV/0!6.04320.0
11:2211:5212N0:306.006.000.0030#DIV/0!#DIV/0!6.04320.0
11:5212:2212N0:306.006.000.0030#DIV/0!#DIV/0!6.04320.0
12:2212:5212N0:306.006.000.0030#DIV/0!#DIV/0!6.04320.0
12:5213:2212N0:306.006.000.0030#DIV/0!#DIV/0!6.04320.0
Absorption Rate*0.0
6" Dia. Borehole with 6" of Water Equivalent MPI:#DIV/0!
## (+ or - from grade)
** Top of water to base of hole
* last 4 readings
Note:
# from meas. pt. to water surface
10/28/16
10/28/16
10/31/16
Percolation Test Worksheet
Backhoe Pit Test
Project:Proposed Commercial Development Job No.:2-216-0915 Vol. in 1" Wtr Col. (in3):144.0
6900 McCutchen Road Date Excavated:
Bakersfield, CA Soil Classification:Hole Width:12 in.
Hole Length:12 in.
Test Hole No.:P1BPresoaking Date:
Tested By:NMTest Date:Ref Pt Height-9 ft ##
Pit Floor Depth:9 ft.
Time
Start
Time
Finish
Depth of
Test
Hole (in)#
Refill-
Yes or
No
Elapsed
Time
(hrs:min)
Initial
Water
Level# (ft)
Final
Water
Level#
(in)
∆ Water
Level (in.)∆ Min.
Meas.
Perc Rate
(min/in)
6" Dia. x
6" Water
Equiv.
MPI:
Avg. Ht. of
Water
Column**
(in.)
Wetted
Surf. Area
of Column
(in2)
Absorp.
Rate
(gpd/ft2)
9:249:5412Y 0:306.000.006.003052.03.028889.8
9:5410:0412Y 0:106.000.006.001020.73.0288269.3
10:1910:3412Y 0:156.002.004.001541.84.0336102.6
10:3610:5112Y 0:156.002.004.001541.84.0336102.6
10:5111:0612Y 0:156.002.004.001541.84.0336102.6
11:0611:2112Y 0:156.002.004.001541.84.0336102.6
11:2111:4612Y 0:256.002.004.002562.94.033661.6
11:4612:0112Y 0:156.002.004.001541.84.0336102.6
Absorption Rate*92.3
6" Dia. Borehole with 6" of Water Equivalent MPI:1.9
## (+ or - from grade)
** Top of water to base of hole
* last 4 readings
Note:
10/28/16
10/28/16
10/31/16
# from meas. pt. to water surface
Percolation Test Worksheet
Backhoe Pit Test
Project:Proposed Commercial Development Job No.:2-216-0915 Vol. in 1" Wtr Col. (in3):144.0
6900 McCutchen Road Date Excavated:
Bakersfield, CA Soil Classification:Hole Width:12 in.
Hole Length:12 in.
Test Hole No.:P2APresoaking Date:
Tested By:NMTest Date:Ref Pt Height-6 ft ##
Pit Floor Depth:6 ft.
Time
Start
Time
Finish
Depth of
Test
Hole (in)#
Refill-
Yes or
No
Elapsed
Time
(hrs:min)
Initial
Water
Level# (ft)
Final
Water
Level#
(in)
∆ Water
Level (in.)∆ Min.
Meas.
Perc Rate
(min/in)
6" Dia. x
6" Water
Equiv.
MPI:
Avg. Ht. of
Water
Column**
(in.)
Wetted
Surf. Area
of Column
(in2)
Absorp.
Rate
(gpd/ft2)
9:119:4112N0:306.006.000.0030#DIV/0!#DIV/0!6.04320.0
9:4110:1112N0:306.006.000.0030#DIV/0!#DIV/0!6.04320.0
10:1110:4112N0:306.006.000.0030#DIV/0!#DIV/0!6.04320.0
10:4111:1112N0:306.006.000.0030#DIV/0!#DIV/0!6.04320.0
11:1111:4112N0:306.006.000.0030#DIV/0!#DIV/0!6.04320.0
11:4112:1112N0:306.006.000.0030#DIV/0!#DIV/0!6.04320.0
12:1112:4112N0:306.006.000.0030#DIV/0!#DIV/0!6.04320.0
12:4113:1112N0:306.006.000.0030#DIV/0!#DIV/0!6.04320.0
Absorption Rate*0.0
6" Dia. Borehole with 6" of Water Equivalent MPI:#DIV/0!
## (+ or - from grade)
** Top of water to base of hole
* last 4 readings
Note:
10/28/16
10/28/16
10/31/16
# from meas. pt. to water surface
Percolation Test Worksheet
Backhoe Pit Test
Project:Proposed Commercial Development Job No.:2-216-0915 Vol. in 1" Wtr Col. (in3):144.0
6900 McCutchen Road Date Excavated:
Bakersfield, CA Soil Classification:Hole Width:12 in.
Hole Length:12 in.
Test Hole No.:P2BPresoaking Date:
Tested By:NMTest Date:Ref Pt Height-11 ft ##
Pit Floor Depth:11 ft.
Time
Start
Time
Finish
Depth of
Test
Hole (in)#
Refill-
Yes or
No
Elapsed
Time
(hrs:min)
Initial
Water
Level# (ft)
Final
Water
Level#
(in)
∆ Water
Level (in.)∆ Min.
Meas.
Perc Rate
(min/in)
6" Dia. x
6" Water
Equiv.
MPI:
Avg. Ht. of
Water
Column**
(in.)
Wetted
Surf. Area
of Column
(in2)
Absorp.
Rate
(gpd/ft2)
9:159:4512Y 0:306.001.504.503073.03.832459.8
9:4510:1512Y 0:306.002.004.003083.54.033651.3
10:1510:4512Y 0:306.002.004.003083.54.033651.3
10:4511:1512Y 0:306.002.004.003083.54.033651.3
11:1511:4512Y 0:306.002.004.003083.54.033651.3
11:4512:1512Y 0:306.002.004.003083.54.033651.3
12:1512:4512Y 0:306.002.004.003083.54.033651.3
12:4513:1512Y 0:306.002.004.003083.54.033651.3
Absorption Rate*51.3
6" Dia. Borehole with 6" of Water Equivalent MPI:3.5
## (+ or - from grade)
** Top of water to base of hole
* last 4 readings
Note:
10/28/16
10/28/16
10/31/16
# from meas. pt. to water surface
Percolation Test Worksheet
Backhoe Pit Test
Project:Proposed Commercial Development Job No.:2-216-0915 Vol. in 1" Wtr Col. (in3):144.0
6900 McCutchen Road Date Excavated:
Bakersfield, CA Soil Classification:Hole Width:12 in.
Hole Length:12 in.
Test Hole No.:P3APresoaking Date:
Tested By:NMTest Date:Ref Pt Height-6 ft ##
Pit Floor Depth:6 ft.
Time
Start
Time
Finish
Depth of
Test
Hole (in)#
Refill-
Yes or
No
Elapsed
Time
(hrs:min)
Initial
Water
Level# (ft)
Final
Water
Level#
(in)
∆ Water
Level (in.)∆ Min.
Meas.
Perc Rate
(min/in)
6" Dia. x
6" Water
Equiv.
MPI:
Avg. Ht. of
Water
Column**
(in.)
Wetted
Surf. Area
of Column
(in2)
Absorp.
Rate
(gpd/ft2)
8:579:2712Y 0:306.005.001.00303017.05.540810.6
9:279:5712N0:305.004.500.50306031.14.83725.8
9:5710:2712N0:304.504.250.253012059.24.43543.0
10:2710:5712N0:304.254.000.253012057.14.13423.1
10:5711:2712N0:304.003.750.253012055.13.93303.3
11:2711:5712N0:303.753.500.253012053.13.63183.4
11:5712:2712N0:303.503.250.253012051.13.43063.5
12:2712:5712N0:303.253.000.253012049.13.12943.7
Absorption Rate*3.5
6" Dia. Borehole with 6" of Water Equivalent MPI:52.0
## (+ or - from grade)
** Top of water to base of hole
* last 4 readings
Note:
10/28/16
10/28/16
10/31/16
# from meas. pt. to water surface
Percolation Test Worksheet
Backhoe Pit Test
Project:Proposed Commercial Development Job No.:2-216-0915 Vol. in 1" Wtr Col. (in3):144.0
6900 McCutchen Road Date Excavated:
Bakersfield, CA Soil Classification:Hole Width:12 in.
Hole Length:12 in.
Test Hole No.:P3BPresoaking Date:
Tested By:NMTest Date:Ref Pt Height-10 ft ##
Pit Floor Depth:10 ft.
Time
Start
Time
Finish
Depth of
Test
Hole (in)#
Refill-
Yes or
No
Elapsed
Time
(hrs:min)
Initial
Water
Level# (ft)
Final
Water
Level#
(in)
∆ Water
Level (in.)∆ Min.
Meas.
Perc Rate
(min/in)
6" Dia. x
6" Water
Equiv.
MPI:
Avg. Ht. of
Water
Column**
(in.)
Wetted
Surf. Area
of Column
(in2)
Absorp.
Rate
(gpd/ft2)
9:009:3012Y 0:306.003.752.2530137.04.937825.6
9:3010:0012N0:303.752.751.00303012.53.330014.4
10:0010:3012N0:302.751.751.00303010.52.325217.1
10:3011:0012Y 0:306.005.001.00303017.05.540810.6
11:0011:3012N0:305.004.001.00303015.04.536012.0
11:3012:0012N0:304.003.001.00303013.03.531213.8
12:0012:3012N0:303.002.001.00303011.02.526416.3
12:3013:0012N0:302.001.001.0030309.01.521619.9
Absorption Rate*15.5
6" Dia. Borehole with 6" of Water Equivalent MPI:11.6
## (+ or - from grade)
** Top of water to base of hole
* last 4 readings
Note:
10/28/16
10/28/16
10/31/16
# from meas. pt. to water surface
Percolation Test Worksheet
Backhoe Pit Test
Project:Proposed Commercial Development Job No.:2-216-0915 Vol. in 1" Wtr Col. (in3):144.0
6900 McCutchen Road Date Excavated:
Bakersfield, CA Soil Classification:Hole Width:12 in.
Hole Length:12 in.
Test Hole No.:P4APresoaking Date:
Tested By:NMTest Date:Ref Pt Height-5.5 ft ##
Pit Floor Depth:5.5 ft.
Time
Start
Time
Finish
Depth of
Test
Hole (in)#
Refill-
Yes or
No
Elapsed
Time
(hrs:min)
Initial
Water
Level# (ft)
Final
Water
Level#
(in)
∆ Water
Level (in.)∆ Min.
Meas.
Perc Rate
(min/in)
6" Dia. x
6" Water
Equiv.
MPI:
Avg. Ht. of
Water
Column**
(in.)
Wetted
Surf. Area
of Column
(in2)
Absorp.
Rate
(gpd/ft2)
13:1813:4812Y 0:306.003.752.2530137.04.937825.6
13:4814:1812N0:303.752.751.00303012.53.330014.4
14:1814:4812N0:302.751.751.00303010.52.325217.1
14:4815:1812Y 0:306.004.002.0030158.05.038422.4
15:1815:4812N0:304.003.001.00303013.03.531213.8
15:4816:1812N0:303.002.001.00303011.02.526416.3
16:1816:4812N0:306.005.001.00303017.05.540810.6
Absorption Rate*15.8
6" Dia. Borehole with 6" of Water Equivalent MPI:11.4
## (+ or - from grade)
** Top of water to base of hole
* last 4 readings
Note:
10/27/16
10/27/16
10/28/16
# from meas. pt. to water surface
Percolation Test Worksheet
Backhoe Pit Test
Project:Proposed Commercial Development Job No.:2-216-0915 Vol. in 1" Wtr Col. (in3):144.0
6900 McCutchen Road Date Excavated:
Bakersfield, CA Soil Classification:Hole Width:12 in.
Hole Length:12 in.
Test Hole No.:P4BPresoaking Date:
Tested By:NMTest Date:Ref Pt Height-9 ft ##
Pit Floor Depth:9 ft.
Time
Start
Time
Finish
Depth of
Test
Hole (in)#
Refill-
Yes or
No
Elapsed
Time
(hrs:min)
Initial
Water
Level# (ft)
Final
Water
Level#
(in)
∆ Water
Level (in.)∆ Min.
Meas.
Perc Rate
(min/in)
6" Dia. x
6" Water
Equiv.
MPI:
Avg. Ht. of
Water
Column**
(in.)
Wetted
Surf. Area
of Column
(in2)
Absorp.
Rate
(gpd/ft2)
13:2013:5012Y 0:306.004.002.0030158.05.038422.4
13:5014:2012N0:304.003.001.00303013.03.531213.8
14:2014:5012N0:303.002.001.00303011.02.526416.3
14:5015:2012Y 0:306.004.501.50302011.05.339616.3
15:2015:5012N0:304.503.501.00303014.04.033612.8
15:5016:2012N0:303.502.501.00303012.03.028815.0
16:2016:5012N0:306.001.504.503073.03.832459.8
Absorption Rate*26.0
6" Dia. Borehole with 6" of Water Equivalent MPI:6.9
## (+ or - from grade)
** Top of water to base of hole
* last 4 readings
Note:
10/27/16
10/27/16
10/28/16
# from meas. pt. to water surface
Percolation Test Worksheet
Backhoe Pit Test
Project:Proposed Commercial Development Job No.:2-216-0915 Vol. in 1" Wtr Col. (in3):144.0
6900 McCutchen Road Date Excavated:
Bakersfield, CA Soil Classification:Hole Width:12 in.
Hole Length:12 in.
Test Hole No.:P5APresoaking Date:
Tested By:NMTest Date:Ref Pt Height-6 ft ##
Pit Floor Depth:6 ft.
Time
Start
Time
Finish
Depth of
Test
Hole (in)#
Refill-
Yes or
No
Elapsed
Time
(hrs:min)
Initial
Water
Level# (ft)
Final
Water
Level#
(in)
∆ Water
Level (in.)∆ Min.
Meas.
Perc Rate
(min/in)
6" Dia. x
6" Water
Equiv.
MPI:
Avg. Ht. of
Water
Column**
(in.)
Wetted
Surf. Area
of Column
(in2)
Absorp.
Rate
(gpd/ft2)
13:0413:3412Y 0:306.005.001.00303017.05.540810.6
13:3414:0412N0:305.004.500.50306031.14.83725.8
14:0414:3412N0:304.504.000.50306029.14.33486.2
14:3415:0412N0:304.003.500.50306027.13.83246.6
15:0415:3412N0:303.503.000.50306025.13.33007.2
15:3416:0412N0:303.002.500.50306023.12.82767.8
16:0416:3412N0:302.502.000.50306021.12.32528.5
16:3417:0412N0:302.001.500.50306019.01.82289.4
Absorption Rate*8.2
6" Dia. Borehole with 6" of Water Equivalent MPI:21.8
## (+ or - from grade)
** Top of water to base of hole
* last 4 readings
Note:
10/27/16
10/27/16
10/28/16
# from meas. pt. to water surface
Percolation Test Worksheet
Backhoe Pit Test
Project:Proposed Commercial Development Job No.:2-216-0915 Vol. in 1" Wtr Col. (in3):144.0
6900 McCutchen Road Date Excavated:
Bakersfield, CA Soil Classification:Hole Width:12 in.
Hole Length:12 in.
Test Hole No.:P5BPresoaking Date:
Tested By:NMTest Date:Ref Pt Height-6 ft ##
Pit Floor Depth:10 ft.
Time
Start
Time
Finish
Depth of
Test
Hole (in)#
Refill-
Yes or
No
Elapsed
Time
(hrs:min)
Initial
Water
Level# (ft)
Final
Water
Level#
(in)
∆ Water
Level (in.)∆ Min.
Meas.
Perc Rate
(min/in)
6" Dia. x
6" Water
Equiv.
MPI:
Avg. Ht. of
Water
Column**
(in.)
Wetted
Surf. Area
of Column
(in2)
Absorp.
Rate
(gpd/ft2)
13:0613:3612Y 0:306.004.002.0030158.05.038422.4
13:3614:0612N0:304.003.001.00303013.03.531213.8
14:0614:3612N0:303.002.001.00303011.02.526416.3
14:3815:0812Y 0:306.005.001.00303017.05.540810.6
15:0815:3812N0:305.004.001.00303015.04.536012.0
15:3816:0812N0:304.003.001.00303013.03.531213.8
16:0816:3812N0:303.002.001.00303011.02.526416.3
16:3817:0812N0:302.001.001.0030309.01.521619.9
Absorption Rate*15.5
6" Dia. Borehole with 6" of Water Equivalent MPI:11.6
## (+ or - from grade)
** Top of water to base of hole
* last 4 readings
Note:
10/27/16
10/27/16
10/28/16
# from meas. pt. to water surface
Percolation Test Worksheet
Backhoe Pit Test
Project:Proposed Commercial Development Job No.:2-216-0915 Vol. in 1" Wtr Col. (in3):144.0
6900 McCutchen Road Date Excavated:
Bakersfield, CA Soil Classification:Hole Width:12 in.
Hole Length:12 in.
Test Hole No.:P6APresoaking Date:
Tested By:NMTest Date:Ref Pt Height-5.5 ft ##
Pit Floor Depth:5.5 ft.
Time
Start
Time
Finish
Depth of
Test
Hole (in)#
Refill-
Yes or
No
Elapsed
Time
(hrs:min)
Initial
Water
Level# (ft)
Final
Water
Level#
(in)
∆ Water
Level (in.)∆ Min.
Meas.
Perc Rate
(min/in)
6" Dia. x
6" Water
Equiv.
MPI:
Avg. Ht. of
Water
Column**
(in.)
Wetted
Surf. Area
of Column
(in2)
Absorp.
Rate
(gpd/ft2)
10:1410:4412Y 0:306.003.003.0030105.04.536035.9
10:4411:1412N0:303.001.002.0030155.02.024035.9
11:1511:4512Y 0:306.003.003.0030105.04.536035.9
11:4512:1512N0:303.001.002.0030155.02.024035.9
12:1512:4512Y 0:306.003.003.0030105.04.536035.9
12:4513:1512N0:303.001.002.0030155.02.024035.9
13:1513:4512Y 0:306.003.003.0030105.04.536035.9
13:4514:1512N0:303.001.002.0030155.02.024035.9
Absorption Rate*35.9
6" Dia. Borehole with 6" of Water Equivalent MPI:5.0
## (+ or - from grade)
** Top of water to base of hole
* last 4 readings
Note:
10/26/16
10/27/16
10/28/16
# from meas. pt. to water surface
Percolation Test Worksheet
Backhoe Pit Test
Project:Proposed Commercial Development Job No.:2-216-0915 Vol. in 1" Wtr Col. (in3):144.0
6900 McCutchen Road Date Excavated:
Bakersfield, CA Soil Classification:Hole Width:12 in.
Hole Length:12 in.
Test Hole No.:P6BPresoaking Date:
Tested By:NMTest Date:Ref Pt Height-9 ft ##
Pit Floor Depth:9 ft.
Time
Start
Time
Finish
Depth of
Test
Hole (in)#
Refill-
Yes or
No
Elapsed
Time
(hrs:min)
Initial
Water
Level# (ft)
Final
Water
Level#
(in)
∆ Water
Level (in.)∆ Min.
Meas.
Perc Rate
(min/in)
6" Dia. x
6" Water
Equiv.
MPI:
Avg. Ht. of
Water
Column**
(in.)
Wetted
Surf. Area
of Column
(in2)
Absorp.
Rate
(gpd/ft2)
10:1610:4612Y 0:306.003.003.0030105.04.536035.9
10:4611:1612N0:303.001.002.0030155.02.024035.9
11:1711:4712Y 0:306.003.502.5030126.24.837229.0
11:4712:1712N0:303.001.002.0030155.02.024035.9
12:1712:4712Y 0:306.003.502.5030126.24.837229.0
12:4713:1712N0:303.001.002.0030155.02.024035.9
13:1713:4712Y 0:306.003.502.5030126.24.837229.0
Absorption Rate*32.4
6" Dia. Borehole with 6" of Water Equivalent MPI:5.6
## (+ or - from grade)
** Top of water to base of hole
* last 4 readings
Note:
10/26/16
10/27/16
10/28/16
# from meas. pt. to water surface
Percolation Test Worksheet
Backhoe Pit Test
Project:Proposed Commercial Development Job No.:2-216-0915 Vol. in 1" Wtr Col. (in3):144.0
6900 McCutchen Road Date Excavated:
Bakersfield, CA Soil Classification:Hole Width:12 in.
Hole Length:12 in.
Test Hole No.:P7APresoaking Date:
Tested By:NMTest Date:Ref Pt Height-5 ft ##
Pit Floor Depth:5 ft.
Time
Start
Time
Finish
Depth of
Test
Hole (in)#
Refill-
Yes or
No
Elapsed
Time
(hrs:min)
Initial
Water
Level# (ft)
Final
Water
Level#
(in)
∆ Water
Level (in.)∆ Min.
Meas.
Perc Rate
(min/in)
6" Dia. x
6" Water
Equiv.
MPI:
Avg. Ht. of
Water
Column**
(in.)
Wetted
Surf. Area
of Column
(in2)
Absorp.
Rate
(gpd/ft2)
9:209:5012Y 0:306.004.002.0030158.05.038422.4
9:5010:2012N0:304.002.002.0030156.03.028829.9
10:2010:5012Y 0:302.000.501.5030205.71.320431.7
10:5711:2712N0:306.004.002.0030158.05.038422.4
11:2711:5712Y 0:304.002.501.5030208.43.330021.5
11:5712:2712N0:302.501.001.5030206.31.822828.3
12:2712:5712Y 0:306.004.501.50302011.05.339616.3
12:5713:2712N0:304.503.001.5030209.03.832419.9
13:2713:5712Y 0:303.001.501.5030207.02.325225.6
Absorption Rate*22.6
6" Dia. Borehole with 6" of Water Equivalent MPI:8.0
## (+ or - from grade)
** Top of water to base of hole
* last 4 readings
Note:
10/26/16
10/27/16
10/28/16
# from meas. pt. to water surface
Percolation Test Worksheet
Backhoe Pit Test
Project:Proposed Commercial Development Job No.:2-216-0915 Vol. in 1" Wtr Col. (in3):144.0
6900 McCutchen Road Date Excavated:
Bakersfield, CA Soil Classification:Hole Width:12 in.
Hole Length:12 in.
Test Hole No.:P7BPresoaking Date:
Tested By:NMTest Date:Ref Pt Height-9 ft ##
Pit Floor Depth:9 ft.
Time
Start
Time
Finish
Depth of
Test
Hole (in)#
Refill-
Yes or
No
Elapsed
Time
(hrs:min)
Initial
Water
Level# (ft)
Final
Water
Level#
(in)
∆ Water
Level (in.)∆ Min.
Meas.
Perc Rate
(min/in)
6" Dia. x
6" Water
Equiv.
MPI:
Avg. Ht. of
Water
Column**
(in.)
Wetted
Surf. Area
of Column
(in2)
Absorp.
Rate
(gpd/ft2)
9:249:5412Y 0:306.004.002.0030158.05.038422.4
9:5410:2412N0:304.002.501.5030208.43.330021.5
10:2410:5412Y 0:302.501.001.5030206.31.822828.3
10:5611:2612N0:306.004.501.50302011.05.339616.3
11:2611:5612Y 0:304.503.001.5030209.03.832419.9
11:5612:2612N0:303.001.501.5030207.02.325225.6
12:2612:5612Y 0:306.004.501.50302011.05.339616.3
12:5613:2612N0:304.503.001.5030209.03.832419.9
Absorption Rate*20.5
6" Dia. Borehole with 6" of Water Equivalent MPI:8.8
## (+ or - from grade)
** Top of water to base of hole
* last 4 readings
Note:
10/26/16
10/27/16
10/28/16
# from meas. pt. to water surface
Percolation Test Worksheet
Backhoe Pit Test
Project:Proposed Commercial Development Job No.:2-216-0915 Vol. in 1" Wtr Col. (in3):144.0
6900 McCutchen Road Date Excavated:
Bakersfield, CA Soil Classification:Hole Width:12 in.
Hole Length:12 in.
Test Hole No.:P8APresoaking Date:
Tested By:NMTest Date:Ref Pt Height-6 ft ##
Pit Floor Depth:6 ft.
Time
Start
Time
Finish
Depth of
Test
Hole (in)#
Refill-
Yes or
No
Elapsed
Time
(hrs:min)
Initial
Water
Level# (ft)
Final
Water
Level#
(in)
∆ Water
Level (in.)∆ Min.
Meas.
Perc Rate
(min/in)
6" Dia. x
6" Water
Equiv.
MPI:
Avg. Ht. of
Water
Column**
(in.)
Wetted
Surf. Area
of Column
(in2)
Absorp.
Rate
(gpd/ft2)
9:009:3012Y 0:306.005.001.00303017.05.540810.6
9:3010:0012N0:305.004.500.50306031.14.83725.8
10:0010:3012N0:304.504.000.50306029.14.33486.2
10:3011:0012N0:304.003.500.50306027.13.83246.6
11:0011:3012N0:303.503.000.50306025.13.33007.2
11:3012:0012N0:303.002.500.50306023.12.82767.8
12:0012:3012N0:302.502.000.50306021.12.32528.5
12:3013:0012N0:302.001.500.50306019.01.82289.4
Absorption Rate*8.2
6" Dia. Borehole with 6" of Water Equivalent MPI:21.8
## (+ or - from grade)
** Top of water to base of hole
* last 4 readings
Note:
10/26/16
10/27/16
10/28/16
# from meas. pt. to water surface
Percolation Test Worksheet
Backhoe Pit Test
Project:Proposed Commercial Development Job No.:2-216-0915 Vol. in 1" Wtr Col. (in3):144.0
6900 McCutchen Road Date Excavated:
Bakersfield, CA Soil Classification:Hole Width:12 in.
Hole Length:12 in.
Test Hole No.:P8BPresoaking Date:
Tested By:NMTest Date:Ref Pt Height-9 ft ##
Pit Floor Depth:9 ft.
Time
Start
Time
Finish
Depth of
Test
Hole (in)#
Refill-
Yes or
No
Elapsed
Time
(hrs:min)
Initial
Water
Level# (ft)
Final
Water
Level#
(in)
∆ Water
Level (in.)∆ Min.
Meas.
Perc Rate
(min/in)
6" Dia. x
6" Water
Equiv.
MPI:
Avg. Ht. of
Water
Column**
(in.)
Wetted
Surf. Area
of Column
(in2)
Absorp.
Rate
(gpd/ft2)
9:029:3212Y 0:306.005.250.75304023.15.64147.8
9:3210:0212N0:305.255.000.253012065.25.13902.8
10:0210:3212N0:305.004.750.253012063.24.93782.8
10:3211:0212N0:304.754.500.253012061.24.63662.9
11:0212:0212N1:004.504.000.506012058.24.33483.1
12:0212:3212N0:304.003.750.253012055.13.93303.3
12:3213:0212N0:303.753.500.253012053.13.63183.4
Absorption Rate*3.2
6" Dia. Borehole with 6" of Water Equivalent MPI:56.7
## (+ or - from grade)
** Top of water to base of hole
* last 4 readings
Note:
10/26/16
10/27/16
10/28/16
# from meas. pt. to water surface
Percolation Test Worksheet
Backhoe Pit Test
Project:Proposed Commercial Development Job No.:2-216-0915 Vol. in 1" Wtr Col. (in3):144.0
6900 McCutchen Road Date Excavated:
Bakersfield, CA Soil Classification:Hole Width:12 in.
Hole Length:12 in.
Test Hole No.:P9APresoaking Date:
Tested By:NMTest Date:Ref Pt Height-5 ft ##
Pit Floor Depth:5 ft.
Time
Start
Time
Finish
Depth of
Test
Hole (in)#
Refill-
Yes or
No
Elapsed
Time
(hrs:min)
Initial
Water
Level# (ft)
Final
Water
Level#
(in)
∆ Water
Level (in.)∆ Min.
Meas.
Perc Rate
(min/in)
6" Dia. x
6" Water
Equiv.
MPI:
Avg. Ht. of
Water
Column**
(in.)
Wetted
Surf. Area
of Column
(in2)
Absorp.
Rate
(gpd/ft2)
12:2012:5015.5Y 0:306.005.500.50306035.15.84205.1
12:5013:2015.5N0:305.505.000.50306033.15.33965.4
13:2013:5015.5N0:305.004.500.50306031.14.83725.8
13:5014:2015.5N0:304.504.000.50306029.14.33486.2
14:2014:5015.5N0:304.003.500.506012054.13.83243.3
14:5015:2015.5N0:303.503.000.50306025.13.33007.2
15:2015:5015.5N0:303.002.500.50306023.12.82767.8
15:5016:2015.5N0:302.502.000.50306021.12.32528.5
Absorption Rate*6.7
6" Dia. Borehole with 6" of Water Equivalent MPI:26.8
## (+ or - from grade)
** Top of water to base of hole
* last 4 readings
Note:
10/26/16
10/26/16
10/27/16
# from meas. pt. to water surface
Percolation Test Worksheet
Backhoe Pit Test
Project:Proposed Commercial Development Job No.:2-216-0915 Vol. in 1" Wtr Col. (in3):144.0
6900 McCutchen Road Date Excavated:
Bakersfield, CA Soil Classification:Hole Width:12 in.
Hole Length:12 in.
Test Hole No.:P9BPresoaking Date:
Tested By:NMTest Date:Ref Pt Height-10 ft ##
Pit Floor Depth:10 ft.
Time
Start
Time
Finish
Depth of
Test
Hole (in)#
Refill-
Yes or
No
Elapsed
Time
(hrs:min)
Initial
Water
Level# (ft)
Final
Water
Level#
(in)
∆ Water
Level (in.)∆ Min.
Meas.
Perc Rate
(min/in)
6" Dia. x
6" Water
Equiv.
MPI:
Avg. Ht. of
Water
Column**
(in.)
Wetted
Surf. Area
of Column
(in2)
Absorp.
Rate
(gpd/ft2)
12:2512:5514Y 0:306.005.750.253012071.25.94262.5
12:5513:2514N0:305.755.500.253012069.25.64142.6
13:2513:5514N0:305.505.250.253012067.25.44022.7
13:5514:2514N0:305.255.000.253012065.25.13902.8
14:2514:5514N0:305.004.750.2560240126.34.93781.4
14:5515:2514N0:304.754.500.253012061.24.63662.9
15:2515:5514N0:304.504.250.253012059.24.43543.0
15:5516:2514N0:304.254.000.253012057.14.13423.1
Absorption Rate*2.6
6" Dia. Borehole with 6" of Water Equivalent MPI:68.2
## (+ or - from grade)
** Top of water to base of hole
* last 4 readings
Note:
10/26/16
10/26/16
10/27/16
# from meas. pt. to water surface
Percolation Test Worksheet
Backhoe Pit Test
Project:Proposed Commercial Development Job No.:2-216-0915 Vol. in 1" Wtr Col. (in3):144.0
6900 McCutchen Road Date Excavated:
Bakersfield, CA Soil Classification:Hole Width:12 in.
Hole Length:12 in.
Test Hole No.:P10APresoaking Date:
Tested By:NMTest Date:Ref Pt Height-4.5 ft ##
Pit Floor Depth:5 ft.
Time
Start
Time
Finish
Depth of
Test
Hole (in)#
Refill-
Yes or
No
Elapsed
Time
(hrs:min)
Initial
Water
Level# (ft)
Final
Water
Level#
(in)
∆ Water
Level (in.)∆ Min.
Meas.
Perc Rate
(min/in)
6" Dia. x
6" Water
Equiv.
MPI:
Avg. Ht. of
Water
Column**
(in.)
Wetted
Surf. Area
of Column
(in2)
Absorp.
Rate
(gpd/ft2)
11:0511:1510.5Y 0:106.005.500.50102011.75.842015.4
11:1511:2510.5N0:105.505.000.50102011.05.339616.3
11:2511:3510.5N0:105.004.500.50102010.44.837217.4
11:3512:0510.5N0:304.504.000.50306029.14.33486.2
12:0512:3510.5N0:304.003.250.75608035.43.63185.1
12:3513:0510.5N0:303.252.500.75304015.72.928211.5
13:0513:3510.5N0:302.502.000.50306021.12.32528.5
13:4014:1010.5Y 0:306.005.001.00616134.75.54085.2
14:1014:4010.5N0:305.004.250.75304020.44.63668.8
14:4015:1010.5N0:304.253.750.50306028.14.03366.4
15:1015:4010.5N0:303.753.250.506212453.93.53123.3
15:4016:1010.5N0:303.252.750.50306024.13.02887.5
Absorption Rate*6.5
6" Dia. Borehole with 6" of Water Equivalent MPI:27.6
## (+ or - from grade)
** Top of water to base of hole
* last 4 readings
Note:
10/26/16
10/26/16
10/27/16
# from meas. pt. to water surface
Percolation Test Worksheet
Backhoe Pit Test
Project:Proposed Commercial Development Job No.:2-216-0915 Vol. in 1" Wtr Col. (in3):144.0
6900 McCutchen Road Date Excavated:
Bakersfield, CA Soil Classification:Hole Width:12 in.
Hole Length:12 in.
Test Hole No.:P10BPresoaking Date:
Tested By:NMTest Date:Ref Pt Height-8 ft ##
Pit Floor Depth:9 ft.
Time
Start
Time
Finish
Depth of
Test
Hole (in)#
Refill-
Yes or
No
Elapsed
Time
(hrs:min)
Initial
Water
Level# (ft)
Final
Water
Level#
(in)
∆ Water
Level (in.)∆ Min.
Meas.
Perc Rate
(min/in)
6" Dia. x
6" Water
Equiv.
MPI:
Avg. Ht. of
Water
Column**
(in.)
Wetted
Surf. Area
of Column
(in2)
Absorp.
Rate
(gpd/ft2)
11:0511:108.5Y 0:056.005.250.75573.85.641446.8
11:1011:208.5N0:105.255.000.25104021.75.13908.3
11:2011:308.5N0:105.004.750.25104021.14.93788.5
11:3012:008.5N0:304.754.000.75304019.74.43549.1
12:0012:308.5N0:304.003.500.506012054.13.83243.3
12:3013:008.5N0:303.503.000.50306025.13.33007.2
13:0013:308.5N0:303.002.500.50306023.12.82767.8
13:3514:058.0Y 0:306.005.500.506112271.45.84202.5
14:0514:358.0N0:305.505.000.50306033.15.33965.4
14:3515:058.0N0:305.004.500.50306031.14.83725.8
Absorption Rate*5.4
6" Dia. Borehole with 6" of Water Equivalent MPI:33.4
## (+ or - from grade)
** Top of water to base of hole
* last 4 readings
Note:
10/26/16
10/26/16
10/27/16
# from meas. pt. to water surface
6 in.
6 in.
Drop in
water
level
NOTES ON FALL OF WATER RATE DURING PERCOLATION TESTING
AND CONVERTING MEASURED ABSORPTION CAPACITY TO PERCOLATION RATE
Based on EPA 1980 Design Manual: Onsite Wastewater Treatment and Disposal, Caltrans test method 750, and
industry practice, the percolation test for septic systems has commonly been conducted in a 6‐inch diameter
test hole filled with 6 inches of water. The test result is the time it takes water to fall 1 inch in this test hole
(minutes per inch, or mpi). This result is not only dependent of the time it takes for the soil to absorb the
water, but is also proportional to the wetted surface area over which the absorption takes place. If the wetted
surface area doubles (say, by measuring the time it takes water to fall from 13 inches to 12 inches in the test
hole), the water will appear to fall faster compared to watching it fall from 6 to 5 inches. The majority of this
difference is not a result changing head pressure, but results from different seepage face areas – that is, the
more seepage face, the faster the rate of fall in an otherwise homogenous soil. Therefore, unless percolation
tests are conducted in a 6‐inch diameter boring and measuring the rate of fall (mpi) from approximately 6 to 5
inches, the measured percolation rate (in mpi) must be corrected to an equivalent percolation rate that can
then be compared to the various tables of percolation rate vs. allowable loading rates used by regulatory
agencies. See below for the basis for this correction.
Volume of water per linear inch of water fall in borehole:
Vol/in. = గమ
ଵଶ଼ య /௧ య = 0.0164 ft3/in
Percolation Rate (min. per inch) converted to Absorption Capacity (gal/ft2/day):
(valid for 6 in. diameter boring with 6 in. of water)
Perc Rate Absorp. Capacity (Q)
ଵ ൈ .ଵସ ௧ య
ଵ ൈ ଵ
.ଽ଼ଶ ௧ మ ൈ
ൈ ଶସ
ௗ௬ ൈ .ସ଼ଵହ
௧ య ൌ 180 gal/ft2/day
When your perc test uses a boring or hand‐excavated hole to measure the fall of water that is not
6 in. diameter filled with 6 in. of water, you need to calculate an equivalent perc rate (mpi):
Calculate the observed absorption rate based on measured hole size wetted surface area and
the volume of water absorbed through that wetted surface area over a time period
(vol/area/time), then:
To convert that measured absorption capacity (Q in gpd/ft2) to equivalent minutes per inch
(mpi) perc rate: 180/Q = mpi
To convert equivalent perc rate (mpi) [or a perc rate measured in a 6” dia. hole filled with 6” of
water] to absorption capacity (Q): 180/mpi = Q
Percolation Test Wetted Surface Area
(Bottom and sides of 6 in. diameter test hole
filled with 6 in. of water)
Asides = ሺߨ ∗ 6 ∗ 6ሻ/144 = 0.786 ft2
Abottom = ߨݎ ଶ /144 = 0.196 ft2
_______
Atotal = 0.982 ft2
D H
(D)
(H)