HomeMy WebLinkAboutSWG Design - 1/31/2003 DALF T. TAHTA R S _
ON—su . SEWAGE SYSTEM DESIGNS
Phone - (206) 426-5940
W 2450 Deegan Rd . W.
Shelton, WA 98584
METHOD II .
Date : January 9 , 199_
Owner : David C . Baylev
Parcel:*: 420014_00020
Site : 1 . 13 acres .S .s a47� 464011
P
(A) The e:;tremely gravelly soil on the property is a Type A. Three test holes were excavated to depths of seven
feet . %vith no signs of ground water .
(B) Due to the extremely gravelly soils drainage presently
runs vertical and remains on the property. The storm
water -enerated by roofs will be collected , treated and
disposed of through dry wells . The storm water generated
by paved road and parking surfaces will be conveyed by
open ditches then treated and disposed of through a
retention pond .
(C) The treatment provided by the storm cater and on-site
sewage systems is adequate to prevent any public health
impact .
(D) All setbacks from property lines and wells are met or
exceeded .
(E) The domestic water will be provided by a newly developed
public water system meeting a'll County and State
regulations (well referenced below)
(F) The property is generally flat that has recently been
logged and cleared of most trees and brush. Attached is
a copy of a geology report that was developed during the
recent drilling of one neighboring well 230 feet
southwest of the projects proposed drainfield and reserve
area.
(G) The annual rain fall is 60 inches a year with an average
temperature of 55 degrees (F) .
(H) There is no long range plans for the availability of
public sewer in this area .
continued -
GEOLOGIC LOG OF WELL DRILLED NEAR ISLAND LAKE
T 20 N/R 4 W, SECT. 1 , BY ARCADIA DRILLING 12/1 6/94 AND 1 2/19/94
FOR DAVE BAYLEY - MASON COUNTY TITLE, INC
Land Surface
Dark gravel(gray, black, red) with abundant light brown silt and
o fine sand matrix.
-. 14
Light brown, fine to coarse sand (60%) and gravel (40%) with abundant
20 - :-ii -- silt matrix. Amount of matrix and compaction is greater from 24
to 26 feet. Saturated below 16 feet_
WL = 28.5 -_ 26
D ark gravel to 1-inch (60%) with coarse black sand and some fine to
12-19-94 -
T medium sand (40%) and a small amount of gray-brown silt/clay M2 trix.
�- -- 38
Brown coarse sand with some medium sand and occasional pea gravel
43
-'-0 Gray to black gravel to 4-inch (70%) with dark colored coarse sand (3 %)
_- and some light-brown silt matrix. Grades to 60% coarse sand and
40% gravel with light-brown silt admix between 48 and 55 feet_
58
60 - "' °o
:-, Black, fine to medium sand with some gravel and gray-brown silt matrix.
Fine sand component increases and gravel decreases with depth.
73 Clean, dark gravel (black, gray, and green) to 1-inch (80%) with coarse
80 - to fine gray sand (20%).
.o��d:��•
83
Dark brown medium to coarse sand (80%) with 20% gravel to 1-inch.
89
Dark gray, black and green gravel to 4-inch (70%) with fine to coarse
a°=0 98 sand (30%) and some light-brown silt admix_
100 -
Alternating layers of dark-brown coarse to fine sand beds and gravel beds.
Lower units include medium sand layers.
doo°o
120 - _ 118
Dark brown fine to medium silty sand_ Silt matrix is lighter brown.
- 130 Ibtai depth.
140-
David C. Bayley
Method II
Page Two
(I) The present use of this land is vacant land that has been
recently cleared for development . The anticipated use is
for multi—family housing which is consistent with the
present surrounding high density developments .
(J) The growth patterns is from rural to suburban housing in
this area.
(K) There is a 100% reserve area available on the site for
the replacement or addition to the on—site sewage system.
(L) The anticipated sewage , flow for this 1 . 12 acre parcel is
960 gallons per day. This equates to 857 gallons per
acre per day . According to State WAC 248-96-090 , the
minimum land area required under these soil and site
conditions equates to 900 gallons per acre per day.
(M) This development complies with all existing county
regulations .
(N) An alternative on—site sewage system utilizing sand lined
trenches and pressure distribution is the proposed method
of treatment and disposal . This type alternative system
produces effluent that meets Treatment Standard Two ,
which is a requirement according to the Mason County
Department of Health Services ' Design and Construction
Standards for Sewage Disposal Systems (Revised 1/3/95) .
(0) The proposed development meets and exceeds the Sate and
County Minimum Land Area Requirements and On—site Sewage
System Design criteria. This proposal is also consistant
with other county' s policies on minimum land area
requirements in extrememly aquifer sensative areas
(Thurston County — Garry Duvall 786-5455) .
� �arce-` " 1\DLO\I-t�IOCO``'t0
DRAFT
VI
Scale
O `` •y
e
v ` a ♦ ;a
�rrr`
to
I
� - f
r
J �
a 1 �
-9 Q `` i
Grc1 �� +*tWf so 'ad
6
(y-\ COVQfS G(� e
,
h°
-c� of '�