HomeMy WebLinkAbout1981-05-04 Septic System Design ReportTO: Jeanne A. Mubusth, Zoning Administrator
FROM: Michael P. Gaffron, Septic System Inspector
DATE: May 4, 1981
SUBJECT: Septic Testing, McCleary Property, 3445 B3yside Road
0589
I have reviewed the site evaluation report submitted by
CzArl Borg on behalf of Mr. McCleary, and wish to cake
the following comments:
1. Testing was done the beginning of April. In nearly
all holes the water table was found to be at a depth
of 1.0-1.8 feet below the surface. This coupled with
my borings in December 1979 indicate thit the water -
table fluctuates, but is probably at least 1 foot
below the surface during most of the year in the areas
tested. (which are the highest portions of the property)
2. Percolation tests were taken at a depth of 15", and
where water table was Leiow the hole an average percolation
rate of 17 minutes per inch was found. The black silty
organic clays of the site are underlain by seams of
sand and gray silty clay.
3. Based on the above firings, it seems that the major
limiting site factor is the water table, which normally
f(,r a mjund system would have to be at least 2 to 3
feet below tLe surface as a minimum. Th(i design
proposed by the ipplicant's site evaluator includes
adding a layer of till from the site over the natural
surface to increase the depth to water table to 2 feet
or more. This appears to be the best method as long
as A) the material used for fill is essentially the
same organic silty clay as that on the drainfield
siter and B) the fill material and existing soil are
Plowed or scarified to minimize any layering effect
that could occur, which might crAate a permeability
boundary and cause lateral seepage.
4. The proposal incorporates a separate rockbed for each
house within a single sand mound/berm. This method
will Lllow for separation of each residence'n effluent
and will help to determine liability should system
failure ever occur.
5. The existing well/hand pump system should be properly
filled and sealed prior to any construction on the
site.
Septic
Testing, McCleary Prolsr:y
May
50 1981
page
Z
6.
Inherent in the design proposed are individual separate
septic tanks and holdirt-I tattke for each resit:once.
-'
These should be located )n :he individual lots so that
the only pipes; crossin3 lot lines are the three
pressure distribution manifolds from the residences.
7.
The proposed design meets criteria for a mound system
within the sheet flow fJoodllain area.
S.
Further items needing to be addresses include:
"
a) Can the proposed layrnit to constructed within the
applicant's proposed lot line mrranger.ent and still
allow for a driveway on the common lot? A sc-aled
site'plan should be subnittod fur review, showing
all proposed improv &-!nt s.
b) What are the provi3O ons fur an altei-rtate drainfield
site? If nude er.itt s, ; would recor-traend that if
failure occurs, tht- hollinq tank system for all
waste would he requ i ra 1.
a) Subheadinq M) of !iy memo of 1-21-81, still needs
to be addressed. (.frwnership and responsibijity
for meintenan(:e aril repair)
For the record, the re•hni:al justificatie.n for alluwinq
a graywater m.und/ho<<i,n(j tanM system on this site is
a) adequate area exists for a mound sy.,temf b) adequate
percolation iat:es oory den'onef.rat'ed where the water table
l.ermf tteeii c) the Mrul;osed syrttent is designed to cmnpensate
for the high water table. (Note that, normally, no system
would have been all(.wed it this area, anal holling t.anku
as well as the tround syst.ea ar�s a variance to the .)n-trite
ordinance) d) the holding teink/graywater r-onbin.rtic.,st will
reduce the on -site treattt.t:nt required for:
8OD - by approxiinat.ely Sol
N - by apptoxisnately 60%
P - by aphroxi.nately 50%
Total water use by aljpr(,xitnat�:ly 4ut
(leased on Manual of gray Water Treatment Pra4tice
T ,le 6 p. 77)
Hence the system wi 11 ctut haves as great are ttilpac-t c#n the
soil/water system of t 1.t! ore j an a tuta) racitjal l dyst.N►a
would, ,nd Should tJA Crtl.rte any 1.11AL1e E.c.11�ttion or health
prublemn for the, ;area.
pok. O tt'1 ��Lf-i%k .
E AST LAKE 4T.
V% %MAY K10 tl m t�o SY ST E
Se! CA0640 e^ou*ro LUVouT
5. V. v St O R+GwK � C R,nt�f
tNtta 0•u%OyAL Mftt-w a sY;tLk#&
WW46 %& C pVVAPT#644 WITMO WMAT
W%6A- A"PPtwt IT B4 O.-St in04bj4
_EKI`T,#J & '6J tJ. TO X*6 C"'Ati� vJ6TN %�Q1t, 11, 19R 1
vJ%TM C.0 j"ATIL irNLL OLVTM . Cb,. �C. r
Npt , lJu. 1,(A
• 1pv� � Iti M— Q(c ATxY
pita%3o 0 M 0.
SOIL l3or iN G Locv '
Itj -S.o' Lit. GRAY su.TY Shsab - u t-
SA! -6.5 lalA[!k S I.T Y CLAY - ow fkuv.. Sor• h1 w
6.5' -6.0(;Uy SILTY CLAY
W Ti,L LevtL @ 31- Ar ML V1 "wiRS - 2k% oa 4.3-a1
Sy3- 2
r�r
o -2.0 'bk. GRAY - ZLkoz • SILTY CLAY • OwAwtc. craw 1•
2.6- 4.0 GRAY - %%L Y. CLAYEY FIML Sn►M -"YR. co ft*r
4.p' - 4.S'� bi.- G-P-hY SANOK CLoky.. oRG ^vuc " Coor
4.G - E.0 tt . GRAY - Sit.TY CLOY - pecw►w►c - sbKG PkA-
�� - wE W*VrdiL ( vot. e%V - 4-3-61
4 - 2.5' BLAC.r SILTY CLkY. SCwT - OR.6huIC.
PAY Sit-TY CLAY Soft - Y42Y R/KTIC
b . GUY CLAY • SE ^mS CO SAtjO -
W&T WhTa2 LiEvet. IV • 4-3"8�
r`_1A.TCQIAt, G0CyVa-rati4� /►.� 1�u. '�3ot.1A7iS
MAY S&
f
�o
s-
o o. z
a :ti
?O Lima RA i
� 00.1 •��
8•�. "' 'i�,P 1` 1tw�J i�tr�k.. ca S.Is . •T'p�:i. Cott EL. loe.�o C11y:�ra
Loc.N-T c'L . 4)R-tik Wl pLt EL.
P•Z q�.� !. o ciS.6
-3 SSA
P-'4
lop, ? 4 I . fj s4 �' 6
%Pj.% yb.2- l.1 14 +5.1
G-1 15" c-,e-
R 15" c.)L L ip
��lpi cI. %-t ANt.w% G 10
o
G 'i•, R to `tt�l.t.t,
iL
4� u_.r•E 0P,,