HomeMy WebLinkAbout1980-08-25 Septic System Site ReportSIT EVALUATION REPORT
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FOR 3D BRG :•TN III G R0110
On August le, 1980 five percolation holes were tested and two
soil borings talcen on the Ed Brown property to find an area suit-
able for up--rading an existing drainfield system. Because of the
existence of a high water table, the percolation holes were dug to
a two foot depth to test for a shallow trench system. These holes
were 6-inches in diameter. The soi' borings wore dug b inches in
diameter to the 4 root depth and 3 inches in diameter to the re-
maining depth. All roles were dug with bucket type 'nand operated
augers.
The average percolation rate was 29.0 minutes per inch which
is adequate for a shallow trench system. However, with the high
water table the trenches can only be about a half a foot to a foot
deep. Then material will need to be placed over the drainfield for
cover. For a three bedroom house and a 29 MPI percolation rate the
drainfield trcr_c=: area would n9ed to be at the least ?50 sq.ft. and
preferably 900 sq.ft. This could be 3 tronches 3 feet wide and 100
feet long for each trench. If enough area exists up the bill from
the present trenches which is not saturated with backed up effluent,
the trenches could be placed there. This can be determined when the
tanrzs and present distribution pipe is exposed. If enough good area
does not exist there the fence on the kennel will have to taken down
and that area used for trenches.
Additional information follows on tha design of the syste:i. If
any additional information is needed, please contact me.
Sinceroly,
PERCOR, INC..
Mark S, Gronberg, P.E.
Lot 59 Block 1
SWAN LAKE ADD7 'ii;.a
'Percolation Results
Hole No,
Material
Percolation Rate
P-1
Black Loam
17.1 Min./inch
P-2
Black Loam
16.0
P-)
Black Clay Loam
40.0
P.4
Black Clay Loam
48.0
P-5
Black Loam
24.0
The average percolation rate is 29.o minutes per inch.
Soil Borings
S. B, i� 1
Depth(ft.) Material
0.0-1.0 Black Loam
1.0-3.2 Black Clay Loam
3.2-5,0 Gray Clay
Mottled soil at 3.2 feet and water table at
3.4 feet after 24 hours.
S.B. # 2
Depth(ft.) Material
0.0-2.0 Black Loam
2.0-4.0 Black ,Cla7 Loam
4,0-5.0 Gray Clay
Water table at 3.4 feet 24 hours.
SYSTEM DESIGN
1, Percolation Rate, rl�rpe of System
29.0 Minutes per inch. Shallow french System.
2.,Proposed Flow Rate
3 bedrooms. 150 gal.ons per bedroom per day = 450 GPD.
3. Soil Treatment AreaReouired
1.67 sq.ft. per GPD for 16-30 percolation rate or 2.00 sq.ft.
per GPD for 30-45 percolation rate = 750 to 900 sq.ft.
4. Size of Trenches
3 trenches eAch 100 feet long and 3 foot wide would yield 900
sq.ft, of soil treatment area. These trenches would be spaced a
YhinimTri of 7.5 feet centAr to -6enter.
5, Septic Tanks I
Existing tank(s) should be -Inspected for suitabilit-, A second
tank should be installed if one is not present.
6. Filter ?Material Required
or 900 sq.ft. of trench bottom 33.3 cubic meat of rock is req-
uirdd-°for 6 -inches of rock bolbtr th6 pipe and 2 inches of dock
over the 4 inch distribution pipe.
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Telephone 473.7357
CITY of ORONO
Yost Office Box 66•Crystal Bay, Minnesota 55323•Municipal Offices
On the North Shore of Lake Minnetonka
September 8, 1980
Mr. Edward C. Brown III
135 Cygnet Place
Long Lake,
Minnesota 55356
Re: Septic System
Dear Mr. Brown:
I have reviewed the site evaluation report submitted for repairs
to your septic system. Based on the soil boring data, the high water
table will necessitate extremely shallow trenches with fill brought in
from outside sources for cover. Care should be taken to keep the trenches
as far uphill and away from the pond as possible. I would suggest you
contact one or more licensed contractors (I believe you have a list) to
bid the work based on the report, noting that 900 s.f. of drainfield will
require 33.3 cubic yards of rock, not cubic feet. Also if no second
tank exists, a precast concrete 750 gallon minimum tank should be added
to the system. The need for tank repair/addition should be determined
by your contractor before drainfield construction is started.
Please have your contractor contact this office for the required permit.
If you have questions, please do not hesitate to call.
Sincerely,
Michael P. Gay
On -Site Systems Manager
MPG:kh