HomeMy WebLinkAbout990100001 Geotech Assessment.`
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re ire ~itigat~~g con~itioins ~ thn~ `will, in the` `l~d~i~~'~f~tr
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6 judgment, substantially secure the objectives of th~~ ~ ~~ii~tion.~
~ All conditions of approval required
8 ~ . 6Q~ a is for ~ Cori i t~ ns ~~~
9 pursuant to this section shall be based upon either the substantive
to requirements o! this se~tidn or the recommendations of a qualified
11 professional, `contained'~within~a`~special report required under this
12 section.
13
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48
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1 2 Butter perimeters shall be marked with te
ar
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2 .
~ leet
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dred
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interval of one per parcel or every one h ~ ~ -~
ns shall remain in
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Si
The
during approved construction act3,vities. g
4. contain the following statement: "Landsl
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g e ation.
Ve
Native
Butter - Do Not Remove or Alter Existing g
g
7
A notice to title shall be recorded with the Auditor in a
g 3, tom approved by the Prosecuting Attorney.
9
10
11
4. fat and bindin site fan
In the case of short plat~
lonnCount Subdivision Ordiaaaae,
tt
Y
12 s
e
approvals under the Je
ude on
as amended, the applic
4-0526-92
i
al
13 ,
No.
the
of
oundar
the face of any such insarumsn
b y
14
15 buf f er
landslide hazard area an
16 '
Rectuirements: The following landslide
- Standard
17
18 .
~~ 506 uffers
hazard area buffer provisions shall apply.
19
20 '
1.
Buffer areas shall be required to provide sufficient
the landslide hazard area and the
1
2
separation between
22 adjacent proposed project.
23
24
2.
The appropriate width of the landslideationrofathe standard
lic
a
ith
2g pp
er.
shall be determined by e
buffer width set forth below; or, an individual or firm
26 meeting the criteria of subsection 11.702, below.
27
2 8
29
30
3.
Buffers shall remain naturally vegetated. Where buffer
urred during construction, replanting
31
disturbance has occ
with native vegetation shall be required.
32
33
34
4.
Buffers shall be retained in their natural condition,
of vegetation to enhance views may bE
in
35
~ g.
however, minor prun
ermitted by the Administrator on a case by case basis.
36 p
37
All buffers shall be measured perpendicularly from the op,
38 5. toe or edge of the landslide hazard area boundary.
39
40
41
6.
A standard buffer of thirty (30) feet shall bhazardbareas.
f landslide
42 from the top, toe and all edges o
43
44
9.507 R The Administrator may reduce the
ec~i~cina Buffer Widths:
tion
width specified in
b
45
standard
landslide hazard area buffer
the
to
the project applicant demonstrates,
h
46
47 en
9.506.6, above, w
satisfaction of the Administrator, that the reduced sliderhazard area
l
h
48 adequately protect the proposed project width
reduced to less than
be
shall the buffer
49 Under no circumstances
50 ten (10) feet.
51
52
46
~/U-. ~ ~'
h _
r*
1
Z ri ering application i'or a project on a parcel
3 o R01 GenerAl: ~ A t gg
ro arty containing a designated geological~orthZbelows area or
4 roal p p e re irements set
5 its buffer shall adhere to th ~
6 •
7 '
8 - ering application shall also
9 1. An applicant submitting a trigg
submit, and have approved, a drainage and erosancecowhenlthe
10
plan, as specified in section 11 ofheriof~thenfollowing:
eit
li triggering application involves
12
13 The alteration a geologically hazardous area or its
14 a -~
15 buffer, or .:.,
. The creatior~~:~ot~~a ~ new parcel wit~iin a known geological y
16 b ,
17 ha z ardour: ~~ az~ea . ~ . .
18 - - iosion control plans required under this ~
~~ Drainage and er
evaluate and recommend-methods to
Zp 2. section shall discuss, of ad acent properties during and
21 minimize sedimentation ~
22 after construction.
23
face drainage shall not be directed across drainace must
24 3. Ste. landslide hazard or ravine. If g
2 5 marine bluff , .
discharged from a bluff to adjacent waters.ctedstolthee
26 be
collected above the face of the bluff and dire
27 ti ht line drain and provided with an energy
water by• g line.
28 device at the shore
29 dissipating
30 dition to any erosion control methods specified in the
31 4. In ad trol lan, the Administrator may
32 drainage and erosion con osed or disturbed areas.
require hydroseeding of exp
33
34 d Gradin
35 9.503 Clearing an
36 rovisions regarding clearing shall apply=
37 1. The following p
38 solo ically hazardous areas shall be ~
39 a. Clearing within g g unless the
allowed only fr m April 1 to-November 1,
40
licant demo.~trates that=suc~ activitiesonwreluirements
41 ~ app ntrar to the protects q
esult in impa~ts...~o; .. Y
4 2 r . ~ ~-....~
43 herein. ~ .~~~~-~
44 ,,that clearing necessary to install temporary
4 5 b . Only
sedimentation and erosion control measitiesshal occu
46
~ prior to clearing for roadways or uti ~
4
48 rin limits for roads, septic, water and stormwater
49 c. Clea g erosion control facilities shal
50 utilities, and temporary roved by the Department
51 be marked in the field and app
'or to any alteration of existing native vegetation;
52 pri
,.
44
t
=l
1
Z
3
a
5
6
7
8
9
10
11
12
13
14
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3.4
35
36
37
38
39
40
41
42
43
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47
48
49
50
51
52
a. ~raas of historic failures or potentially unstable
slopes, such as: .
(i)
(fi)
(iii)
~.
,i
~~
areas described and mapped as having severs ar
very severe building limitations !or dwellings
without basements within the United States
Department of Agriculture/Soil Conservation
Service ~-{ ~ at~rv~v for Jefferson County;
areas described and mappedstablecmaterialsdwithin
landslides or slopes of un
the Washington State Department of Ecology
done Atlas of Jef erson County; and
areas described and mapped as areas of poor
natural stability, former landslides and recent
landslides by the Washington State Department of
Natural Resources, Division of Geology and Earth
Resources;
b. Areas potentially unstable.as a result of rapid streaia
incision, stream bank erosion, or undercutting by wave
•
action, and
c. Areas with any indications of earth movement, such as:
(i) rockslides;
(ii) earthflows; ~ ~
( iii) mudf lows; and
(iv) landslides. ._.
3, Seismic hazard areas: Areas subject to severe risk of damag
as a result of earthquake induced ground shaking, slope
failure, settlement, soil liquefaction, or surfaoorlaulting.
These areas are identified by the presence of. p y
drained soils with greater than fifty percent (50$) silt and
very little coarse material; loose sand or gravel, peat,
artificial fill and landslide materials; or soil units with
high organic content. j
ces sed fo Identification: Sources used to identify
geologically hazardous areas include, but are not limited to:
1, United States Department of Agriculture/Soil Conservation
Service, Soil Su vey for Jefferson Count.
' tal Zone t as.
Washington State Department of Ecology, Coas
2.
Washington State Department of Natural Resources, ~1~
3• aste n Jef erson Co t
t t and Geo o c a s•
c
4. Washington State Department of Natural Resources, Ge
~;;~~t-tnat ion System : So i 1 Surve
42
o~ 55 ~ a~ ~~~y
v ,~ ,~-
of }
`~ ATTACHMENT 1-C •. ,... ~ .~
~ t~LVVr.vtr.U ~~~ ~~
'COL l~AGE
" OF OFrIC{ L RECORDS
~ ~ f~_OJEST 4F
~ ,~ JE~FEA~
(, , ' 393`7 ~ _ r . ~ 4,,
- ~ - ~ .. -- .. ~~ oo~~a t~S..El:oRioGE
- _ ~- JEFFERSON CC!,lht7Y AUOiTOR
- • ";
_ - 3 Y PUTY
- ~~
~,
- -
' ~ - . ~ " _ Report _ _ t _
- ~ -~ .. ~ . Geotechnica~Engineering Services _
Subsurface Investigation
Proposed Port Ludlow Division 7
- Part Ludlow, Washington
_ _ ~ - . - April 5, 1995 ~ -
- ~ APR 4 7 1995 -
- - .. _
" ~ ~' ,
- ~' ~ .~` .
. - - r For
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_ ~ ~,~
1 ~ ~ _
. . • ~ ~ Pope Resources
~,
.~ (3eo n sneers
' AUG 0 9 1~9~`
i ~~~~~~~
;D
FEB .1 3 2001
JEFFERSON COUNTY
DEPT. OF COMMUNITY DEVELOPMENT
J ~~~ ~~.~~~`3
von '
File No. 2378-032-'P03/040593
Geo~Fngineers
Pope Resources
P.O. Box 1780
Poulsbo, Washington 98370
Attention: Ms. Linda Mueller
April 5, 1995
D
~= ~ ~ ~ 200
JEFFERSON COUNT`(
DEPT. OF COMMUNITY DEVELOPMENT
We are pleased to submit four copies of our "Report, Geotechnical Engineering Services,
Subsurface Investigation, Proposed Port Ludlow Division 7, Port Ludlow, Washington for Pope
Resources." We appreciate the opportunity to be of service to Pope Resources. Please contact
us if you have questions regarding this project or if we can provide additional services.
Yours very truly,
st.F:cwx:~o
Document ID: 2378032R.R
File No/. 2378-032-'P03
cc: `Pope Resources
781 Walker Way
Port Ludlow, Washington 98365
Attn: Mr. Ray Welch
GeoEngineers, lnc.
6240 Tacoma Mall Bled. Suite 318
Tacoma, WA 99409
Telephone (206) 4,1~a3'9
Fax (206) 4710521
GeoEngineers, Inc.
t !~ /Gt}, ~..~.
Gary W. Henderson
Principal
AUDITOR'S NOTE: ~-~ ~ i~
von J~'l "h.r4
Geotechnical,
Geoenvlronmental annd
lo~lc Servi~xa
hhae an rarcwe p~o«
CONTENTS
INTRODUCTION ................................~...............,.. 1
SCOPE OF SERVICES .............................................. 1
SITE CONDITIONS ................................................ 1
SURFACE CONDITIONS 1
SUBSURFACE EXPLORATIONS 2
SITE GEOLOGY 2
SUBSURFACE CONDITIONS 2
CONCLUSIONS AND RECOMMENDATIONS .............................. .
GENERAL
LANDSLIDE HAZARD ~ ~ ~ ~ ~ ~'
SETBACKS D
EROSION HAZARD
EROSION CONTROL i= ~ ~ ~ ~~~~
SEISMIC VULNERABILITY
EARTHWORK JEFFERSON COUNTY
General DEPT. OF COMMUNITY DEVELOPMENT
~ Clearing and Site Preparation
Subgrade Preparation
Structural Fill
Suitability of On-Site Materials for Fill
Fill Placement on Slopes
Fili Scopes
Fill Drainage
Cut Slopes
Temporary Cut Slopes
Utility Trenches
FOUNDATION SUPPORT
General
Foundation Design
lateral Load Resistance
Foundation Settlement
FLOOR SLAB SUPPORT
RETAINING and SUBGRADE WALLS
Design Parameters
Backdrainage
Construction Considerations
Rockeries
DRAINAGE
PAVEMENT DESIGN AND SUBGRADE PREPARATION
3
3
3
4
4
5
5
6
6
~6
6
7
7
8
8
8
9
9
9
10
10
10
11
11
11
12
12
12
13
13
13
14
LIMITATIONS ................................................... 14
VOi. ~~r,~~ "N..e JJe~
G e o E n g i nee r s ~ File No. 2378-032-703/040595
FIQURE8
Vicinity Map/Site Pian
Foundation Detail
Soil Classification System
Test Pit Logs
APPENDICES
CONTENTS ~continusdl
1
~
2
3
4... 6
Pane No,
Appendix A -Jefferson County Critical Areas Ordinance
A-1
U
~ ~~ ~ ~ 2001
JEFFERSON COUNTY
DEPT. OF COMMUNITY DEVELOPMENT ,
v~~ J ~~~ ~h~~~~~
G e o E n 8 i n e e r s l~ File No. 2378-032-'Ib3/040S9S
REPORT
GEOTECHNICAL ENGINEERING SERVIC
SUBSURFACE INVESTIGATION
PROPOSED PORT LUDLOW DIVISION
PORT LUDLOW, WASHINGTON
INTRODUCTION
~~~ ~ ~ 200
DEPT. OFJCOMMUDN TY DEVE OPMENT
This report presents the results of our geotechnical engineering services for the proposed
Port Ludlow Division 7 residential subdivision to be developed in Port Ludlow, Washington.
The site is located between Rainier Lane and Oak Bay Road, primarily in the northeastern corner
of Section 17, Township 28 North, Range 1 East, Willamette Meridian, as shown on the Vicinity
Map and Site Plan, Figure 1.
We understand that the proposed development will include 22 single-family residences
located as shown on the Site Plan, Figure 1.
SCOPE OF SERVICES
The purpose of our services was to explore subsurface soil and ground water conditions
at the site as a basis for providing geotechnical recommendations and design criteria for t11e
proposed development. Our specific scope of services included the following:
1. Excavate a series of backhoe test pits at the site to explore subsurface soil and ground water
conditions.
2. Evaluate pertinent physical and engineering characteristics of the soils at the site.
3. Provide recommendations for site preparation and earthwork including stripping
requirements, hillside grading, evaluation of on-site soils for use as fill and import fill, and
compaction criteria.
4. Provide recommendations for building setbacks in steep slope areas in accordance with
Jefferson County Critical Areas Ordinance No. OS-0509-94.
5. Provide recommendations for foundation and slab support of the proposed structures
including allowable bearing values and estimates of settlement.
6. Provide recommendations for site drainage, as appropriate.
7. Provide recommendations for pavement design including subgrade preparation.
8. Prepare a report containing our findings along with our conclusions and recommendations.
SITE CONDITIONS
SURFACE CONDITIONS
The proposed subdivision will be located in an upland area south of Port Ludlow Division
1 Area 5 and east of Port Ludlow Division 1 Area 3, as shown on the Site Plan. The majority
of the lots front onto Rainier Lane. The site slopes down from the upland area north of Port
G e o E n g i nee r s V~~ ~~~• j ~h~~ ~~,t Fite No, 2378-032-703/040595
Ludlow Bay. Site slopes range up to about 60 percent .with locally steeper areas. Elevations
range from about 70 to 280 feet above mean sea level (MSL). The majority of this site is
vegetated with mature second growth Douglas fir and cedar trees with a dense understory of
brush. Areas which have been cleared more recently are vegetated with alder trees, brush, and
grass.
Soils exposed in a borrow pit located in the southeast corner of the site consist of very
dense gray fine to medium sand and gravel with a trace of silt. This material is advance outwash.
The face of the borrow pit is on the order of 15 feet in height.
No groundwater seepage or springs were observed at the time of our site visit. A small
creek flows in the valley along the western side of the site, and a seasonally intermittent flow
occurs in the drainage course located in the eastern portion of the site.
SUBSURFACE EXPLORATIONS
Subsurface conditions at the site were explored on February 23, 1995 by excavating 6 test
pits at the approximate locations shown on the Site Plan. The test pits were excavated to depths
ranging from 7 to 10 feet below the ground surface using a John Deere 310C rubber-tired
backhoe. The locations of the test pits were established in the field by taping or pacing from
existing features, and should be considered approximate. A representative from our firm
continuously monitored the excavations and kept a detailed log of the
conditions encountered. Soils were visually classified in general acco e l~3it~~t~
described on Figure 3. The logs of our explorations are attached as Fi through 6.
~- E 8 ~ ~ X001
SITE GEOLOGY ( 1
Our interpretation of the site geology is based on our review of p bDEP OF COMMU~~ D~EVE OPMENT
our library, our site reconnaissance including the borrow pit excavation
site, and subsurface explorations on this site and adjacent sites. In general, the site soils consist
of a surficial mantel of recessional outwash deposits underlain by glacial till. Recessional
outwash deposits consist of sand and gravel deposited by meltwater streams during the periods
of glacial retreat, these soils have not been glacially consolidated. Glacial till consists of a
mixture of clay to boulder-sized soil particles which was deposited by the ice and consolidated
to a very dense condition. The glacial till is underlain by Vashon advance outwash deposits.
Advance outwash deposits consist of sands and gravels deposited by melt water streams in front
of advancing glaciers. These soils were also consolidated by the overlying ice.
SUBSURFACE CONDITIONS
Based on our subsurface explorations the site is overlain by 5 to 7 inches of forest duff
underlain by recessional outwash sand and gravel in a medium dense to dense condition extending
to a depth of 3 to 5 feet. The recessional outwash deposits are underlain by glacial till in a very
dense condition extending beyond the depths explored 7 to 10 feet.
G e o E n i n e e r s $~7i ~C~, ~`^~~ ~'~~~ File No. 2378-032-703/040595
S
Advance outwash deposits were observed along the road cut for Oak Bay Road and in the
abandoned .borrow pit located in the southeastern corner of the site.
Ground water levels are expected to vary seasonally. Perched groundwater was observed
at the contact between the recessional outwash and the underlying glacial till.
CONCLUSIONS AND RECOMMENDATIONS
GENERAL
Based on our observations of surface and subsurface conditions, it is our opinion that the
site is generally suitable for the proposed development. Specific grading plans for the site have
not yet been developed, however, we have addressed general geotechnical considerations for the
project as follows:
• Slopes at the site appear to be stable under existing conditions. General setback
recommendations have been developed.
• Some of the on-site soils are moisture sensitive and it is our opinion that earthwork and
grading will be more economical if performed during dry weather conditions.
• Grading may include fill placement on slopes. All fill should be properly keyed into the
slopes and drained, as appropriate.
• Shallow foundations founded on dense native materials or properly compacted structural fill
may be used for support of structures.
• We anticipate that structures with one or two daylight floors may prove economical on
some of the lots in this development.
• Where mixed subgrade materials occur at footing or floor grades, overexcavation and
replacement with structural fill may be required or alternative footing designs should be
considered.
• Ground water may be seasonally perched immediately above the glacial till. Site
development should include drainage facilities as appropriate to intercept ground water
seepage.
LANDSLIDE HAZARD
A copy of the Geologically Hazardous Areas Section of the Jefferson County Critical Areas
Ordinance is attached as Appendix A. Jefferson County defines landslide hazard areas as:
• Areas of historic failures, including areas of unstable slopes and old and recent landslides.
• Areas potentially unstable as a result of rapid stream incision, stream bank erosion, or
undercutting by wave action.
• Areas described and mapped as having severe or very severe buildin limitations for
dwellings without basements within the United States Dep r~ o~~ic~lt~/~il
Conservation Service Soil Survey for Jefferson County. - ~ ~~
~ E B ~ 3 2~~1
~~.il. 'J 1J~1 ~h..c VI~;
JEFFERSt7N COUNTY
DEPT. OF COMMUNITY DEVEL(?PMENT
G e o E n g i n e e r s 3
r No evidence of landsliding or slope instability was observed on the site. However, we
believe that surficial soils on the steeper slopes will be vulnerable to creep and/or sloughing if
they are disturbed during construction, or if development increases or concentrates surface
drainage or ground water seepage. Fills on or near slopes should be placed on properly
proofrolled and compacted subgrade material, and should be keyed and drained as recommended
below. Graded areas and fill slopes should be revegetated to reduce erosion potential. We
recommend that a surface water drainage system be developed for the. subdivision to collect
drainage from impermeable surfaces and yard areas, and directed it away from slope azeas.
Recommendations for fill construction, drainage and erosion protection are presented in greater
detail in following sections of this report.
The site is located in an area mapped by the Soil Conservation Service (SCS) as having
limitations to construction. of dwellings with basements which range from moderate to severe
depending on the slope. Site soils are included in the Alderwood series in the Soil Survey of
Jefferson County. The soil survey describes the limitations to dwellings without basements as
moderate for slopes ranging from 0 to 15 percent and as severe for slopes greater than 15
percent.
Neither rapid stream incision nor stream bank erosion was observed in the creek along the
western side of the site or in the seasonally intermittent drainages which flow across portions of
the site at the time of our site visit.
The Coastal Zone Atlas of Washington published by the Department of Ecology describes
the slopes on the site as unstable. No recent or ancient landslides are identified on the site by
the Coastal Zone Atlas.
Portions of the site meet the Jefferson County criteria for landslide hazard areas due to the
SCS classification and the Coastal Zone Atlas description of the site. However, based on our site
explorations and experience on similar sites it is our opinion that landslide hazards are not a
limiting factor for this development provided that our recommendat
site development are followed. D
SETBACKS ~ ~ ~ ~ `~ 2~0~
In our opinion, a minimum horizontal setback of 8 feet s ould aintained bNNe~~tyyw,,~~e
foundations and the face of slopes between 15 and 30 percent and r~epr ~~~~~E~i'~ta~ENT
height on this portion of the site. For slopes between 30 and 50 percent we recommend e--
foundation setback be increased to 12 feet, and 20 feet for slopes steeper than 50 percent. For
clarity, an illustration of the recommended setback has been included as Figure 2.
EROSION HAZARD
Jefferson County defines erosion hazard areas as those areas that are classified as having
severe or very severe erosion potential by the SCS. The site is located in an area mapped by the
SCS as having erosion hazards which range from slight to severe depending on slope. Site sails
`. ~. ,.,
G e o E n g i n e e r s i~L •~'~ ( ~h..~ ~~~V File No. 2378-03Z-T03/040S9S
are included in the Alderwood series in the Soil Survey of Jefferson County. The soil survey
• describes the erosion hazard as slight to moderate for slopes ranging from 0 to 15 percent, as
moderate to severe for slopes of 1 S to 30 percent, and as severe for slopes ranging from 30 to
50 percent.
EROSION CONTROL
It is our opinion that the potential erosion hazard of the site is not a limiting factor for the
proposed development. The proposed development will be located primarily in the more gently
sloping portions of the site.
Temporary and permanent erosion control measures should be installed and maintained
during construction or as soon as practical thereafter to limit the additional influx of water to
exposed areas and protect potential receiving waters. Erosion control measures should include
but not be limited to berms and swales with check dams to channel surface water runoff, ground
cover/protection in exposed areas and silt fences. Removal of natural vegetation should be
minimized and limited to the active construction areas, and reestablishment of vegetation should
be undertaken as soon as possible. Graded areas should be shaped to avoid directing runoff onto
cut or fill slopes, natural slopes or other erosion-sensitive areas. Temporary ground
cover/protection such as jute matting, excelsior matting, wood chips or clear plastic sheeting
should be used until permanent erosion protection is established.
We recommend that graded or disturbed slopes be tracked in-place with the equipment
running perpendicular to the slope contours so that the track grouser marks provide a texture to
help resist erosion. Thereafter, all disturbed areas should be revegetated.
We recommend that no loose fill be placed on the slopes and that no water be directed
toward or discharged on the slope areas. Tightlines should be used to direct storm or other
surface water across slope areas.
Long-term erosion control will require that the vegetative cover on the slopes be
_ maintained. Any bare ground areas should be vegetated, as necessary. Erosion resistant plant
species include:
• Woody shrubs such as: Oregon grape, service berry, and salal. ~ ~ ~ Q ~ LS
• Grass mixtures including: rye, fescue, bent, and clover.
• Other deep-rooted site-tolerant vegetation. ~ ~ ~ ~ 3 2007
SEISMIC VULNERABILITY JEFFERSON COUNTY
DEPT. OF COMMUNITY DEVELOPMENT
In our opinion, the site does not contain seismic hazards areas as defined by Je erson
County criteria. The Puget Sound region is a seismically active area; all sites within this region
can be expected to experience some damage in the event of a significant seismic event. Certain
factors can result in increased probability or degree of damage at a particular site. We did not
encounter conditions which in our opinion place this site at risk of unusual damage in the event
C C''~~ ~~~.~
G e o E n g i n e e r s $ File No. 2378-032-T0310.iQ59S
of a significant seismic event. Specifically, potentially liquefiable soils Loose sands and sil
sands below the water table, were not encountered on the site. • ~ ~ ~ Q
EARTHWORK ~ ~ ~ ~ ~ ~~~~
General
We expect that the majority of the grading can be accomplish with ~@~~~~py
earthmoving equipment. DEPT. OF COMMUNITY pEVELOPMENT
Surficial soils at the site generally contain high amounts of silt, and are therefore sensitive
to disturbance when they become excessively wet. Operation of heavy equipment at the site
under wet conditions can be expected to result in considerable disturbance to the exposed
subgrade soils. During wet weather construction, it will probably be necessary to provide
temporary haul roads consisting of quarry spans, crushed rock or pit run sand and gravel. We
recommend that earthwork be undertaken during periods of dry weather, if feasible,. to minimize
grading costs.
Clearing and Site Preparation
The work area should be cleared of all surface and subsurface debris including underbrush,
tree stumps, roots and organic-laden soils. Portions of the project area have previously been
cleared. Our observations indicate that the upper 1/2 to 1 foot of soil contains a significant
amount of organic material, and should be removed from building pads and areas to be paved.
In areas of dense vegetation greater depths of stripping may be required.
If the clearing operations cause excessive disturbance, additional stripping depths may be
necessary. Disturbance to a greater depth can also be expected if site preparation work is done
during periods of wet weather. The organic laden strippings can be stockpiled and used later for
landscaping purposes or be spread over disturbed areas following completion of grading. If
spread out, the organic strippings should be in a layer less that I foot thick, and should not be
placed on slopes. Materials which cannot be used for landscaping or protection of disturbed areas
should be removed from the project site and wasted.
subgrade Preparation
Following stripping, the exposed subgrade should be evaluated prior to placing structural
fill, pavement materials, or constructing foundations. During dry weather, subgrade evaluation
should consist of proofrolling with heavy rubber-tired construction equipment. During wet
weather, subgrade evaluation should be accomplished by hand probing. Any soft areas noted
during proofrolling or probing should be overexcavated and replaced with structural fill as
outlined below. We recommend that a GeoEngineers representative be present during
proofrolling and/or probing to evaluate exposed subgrade soils.
G e o E n g i n e e r s f) File No. 2378-032-?'03/040395
Prior to placement of structural fill, the exposed subgrade should be uniformly compacted
to at least 90 percent of maximum dry density (MDD) determined in accordance with ASTM
D-1557. Where foundations, slabs or pavement are to be founded directly on native material,
we recommend that the subgrade soil be compacted to at least 95 percent of MDD.
Surficial materials over portions of the site contain enough fines (material passing the No.
200 sieve) that compaction of subgrade will be difficult, if not impossible, to achieve during
periods of wet weather. If grading takes place during the wet winter months, it may be necessary
to overexcavate and replace native materials with compacted structural fill containing less than
5 percent fines beneath building and pavement areas. Where underlying subgrades are
excessively wet, it may be necessary to stabilize the subgrade with a layer of quarry spans, clean
gravel, or by placing a layer of geotextile fabric (such as Mirafi 500x}
structural fill.
Q
Structural Filt ~ ~ ~ ~ ~ ~ ~~~~
All fill in embanlanents and beneath structures oz pavements sh uld b laced as structural
fill . Structural fill material should be free of debris, organic con t3~ U M M `j~~~~E~. LSO PM ENT
larger than 6 inches. The workability of material for use as structural i wi epen
gradation and moisture content of the soil. As the amount of fines (material passing the No. 200
sieve) increases, soil becomes increasingly more sensitive to small changes in moisture content
and adequate compaction becomes more difficult or impossible to achieve. If fill material is
imported to the site for wet weather construction, we recommend that it be a sand and gravel
mixture, such as high quality pit run, with less than 5 percent fines.
All structural fill should be compacted in horizontal lifts to at least 90 percent of the MDD
per ASTM D-1557. The uppermost 24 inches of subgrade soils below structures, slabs-on-grade
and pavements should be compacted to at least 95 percent of the MDD. We recommend that the
fill prism supporting footings, defined by a plane extending down from the edges of the footing
at 1 to 1 (horizontal to vertical) to native ground, be compacted to at least 95 percent of MDD.
The lift size used during placement and compaction will depend on the moisture and
gradation characteristics of the soil and the type of equipment being used. If necessary, the
material should be moisture conditioned to near-optimum moisture content prior to compaction.
During fill and backfill placement, sufficient testing of in-place density should be performed to
verify that adequate compaction is being achieved.
Suitability of On-Site Materials for Fill
During dry weather construction, any nonorganic on-site soil and rock may be considered
for use as structural fill provided it is at a suitable moisture content when placed and can be
compacted as recommended. If the material is too wet when excavated, it will require aeration
and drying prior to placement as structural fill. In general the recessional outwash sand and
gravel will be suitable for use as fill during wet weather, while the underlying glacial till will not.
,.., ~~
rll ~.ll 1 1..~
tiI J L ' J V 1 ~h+.. C V ~.~
G e o E n g i n e e r s 7 Filc No. 2378-032-703/040595
p ----
Fill Placement on Slopes
All fill placed on slopes steeper than 5 to 1 (horizontal to verti ) sh
the slope face and include keyways and subdrains. Bench excavations PMENT
into the slope face until a vertical step of about 3 feet is constructed. The excavated materials
may be pushed out and compacted into the structural fill as it is brought up if adequate
compaction can be achieved.
Keyways should be located below fill embankment toe areas where new fills meet existing
hillside slopes. Additional keyways may be necessary depending on the extent of the proposed
fill and the quality of the soil underlying the embankment. Keyways should be embedded at least
2 feet into stable material in the toe area. The width of the keyway will depend on several
factors, such as the vertical height of the fill above the keyway and the size of the equipment used
to construct the keyway. In general, keyways should be at least 10 feet wide or about 1 ~fi times
the width of the equipment used for grading or compaction.
Fill Slopes
Permanent fill slopes should be constructed at inclinations of 2 to 1 (horizontal to vertical)
or flatter, and should be blended into existing slopes with smooth transitions. To reduce
postconstruction sloughing and ravelling, we recommend that fill slopes be overbuilt where
possible and subsequently cut back to expose well compacted fill. Retaining structures should
be used where cut and fill slopes 2 to 1 or flatter cannot be achieved.
To minimize erosion, newly constructed slopes should be hydroseeded as soon as practical.
Until the vegetation is established, some sloughing and ravelling of the slopes should be expected.
Erosion control measures such as temporary covering with clear plastic sheeting, revegetation
fabric or jute matting should be used to protect these slopes until vegetation is established. We
also recommend that graded areas above slopes be shaped to direct surface water away from the
slope face.
Fill Drainage
Subdrains should be installed at the rear of each keyway and at other locations beneath fill
embanlanents where ground water seepage is encountered during grading. The subdrains can be
installed concurrently with fill placement, or in trenches excavated after filling, where the trench
depth would not exceed about 4 feet.
• The drains should consist of afree-draining sand and gravel drainage material, placed in
a trench about 2 feet wide, fully encapsulated within a suitable nonwoven, geotextile filter fabric,
such as Mirafi 140N (or similar material). The drainage material should extend the full height
of the rear keyway wall. Where subdrains are used to intercept ground water seepage at locations
other than at keyways, the drainage material should be at least 3 feet high.
A heavy-wall (SDR-35 or heavier) perforated pipe should be installed near the bottom of
each subdrain and bedded in drainage material. Pipes should have minimum slopes of 1 percent
and should drain to suitable collector and discharge points. All subdrain tines should include
,...
~ ~~ 1 ~,;,,; ~ ,~ ~ Filc No. 2378-032-703/040595
G e o E n g i n e e r s ~~t
cleanout risers. We recommend that the cleanout risers be covered with tamper-proof locking
caps. Discharge pipes should be covered with heavy galvanized wire mesh to prevent rodent
access.
Cut Slopes
Permanent cut slopes in soils should be inclined at 2 to 1 (horizontal to vertical) or flatter,
or should be retained with a properly designed retaining structure. Cut slopes should be
hydroseeded shortly after completion of grading to prevent erosion. Temporary erosion
protection may be necessary as discussed above for newly constructed fill slopes.
Temporary Cut Slopes
Temporary cut slopes are anticipated for construction of underground utilities. All
temporary cut slopes and shoring must comply with the provisions of Title 296 WAC, Part N,
"Excavation, Trenching and Shoring." The contractor performing the work must have the
primary responsibility for protection of workmen and adjacent improvements, deciding whether
to use shoring, and for establishing the safe inclination for open-cut slopes.
Temporary unsupported cut slopes more than 4 feet high may be inclined at 1H:1V
(horizontal to vertical) maximum steepness within native till or structural fill. Flatter slopes may
be necessary if seepage is present on the cut face. Some sloughing and ravelling of the cut slopes
should be expected. Temporary covering with heavy plastic sheeting should be used to protect
these slopes during periods of wet weather.
Utility Trenches
Trench excavation, pipe bedding, and trench backfilling should be completed using the
general procedures described in WSDOT Standard Specifications, Section ?-17, or other suitable
procedures specified by the project civil engineer.
Utility pipes should be bedded in sand and smooth rounded gravel, such as specified in
WSDOT Standard Specifications, Section 9-03.15. Additionally, we recommend that the pipe
be covered with bedding material to at least one foot above the pipe. This bedding material
should be lightly tamped into place. Backfill placed above the bedding material shall consist of
structural fill quality material as discussed above.
Utility trench backfill can be placed in lifts of 12 inches or less (loose thickness) below a
depth of 5 feet from finish grade. Within 5 feet of finish grade, backfill should be placed in lifts
of 8 inches or less (loose thickness) such that adequate compaction can be achieved throughout
the lift. Each lift must be compacted prior to placing the subsequent lift. Prior to compaction,
the backfill should be moisture conditioned to near optimum moisture content, if necessary. The
backfill should be compacted in accordance with the criteria discussed
t,.~ ,
c r '~' ~~
~lvi. ~~~~ ~ ~M.C v
G e o E n g i n e e r s 9
U
D
F E 8 ~ 3 2001
File No. 2R~9U~99~f'`~
DEPT. OF COM!~1!)NITY DEVELOPMENT
FOUNDATION SUPPORT
General
We recommend that residential structures be supported on
p ~c~~od~
FEB 1 3 2001 D
____,_ JEFFERSON,CQUNTY
J;
founded on medium dense to dense native soil, or structural fill, prepared as recommended in the
EARTHWORK section of this report. Shallow spread footings designed and constructed as
described below may be used where minimum setback distances can be achieved on moderate
slopes.
Foundation Design
We recommend that all footing elements be embedded a minimum of 18 inches below the
lowest adjacent finished grade. Where footings are placed on sloping ground, the horizontal
distance from the bottom of the footing to the ground surface should not be less than 8 feet. We
recommend a minimum width of 2 feet for isolated footings and at least 16 inches for continuous
wall footings. Deeper footing embedment may be required where minimum building setbacks
cannot be achieved, and we recommend that design criteria for footings located on or near slopes
be evaluated by a representative from our firm on asite-specific basis.
Footings founded as described above can be designed using an allowable soil bearing
pressure of 2,500 psf (pounds per square foot) for combined dead and long-term Live loads,
exclusive of the weight of the footing and any overlying backfill. This value may be increased
by one-third for transient loads such as those induced by seismic events or wind loadings.
Where a crawlspace is used, footing pads for floor support may be cast on the ground,
providing that the ground is firm and level. These pads should be designed using an allowable
bearing of 1,000 psf applied to dead and live loads.
Structures constructed across mixed subgrade conditions could experience distress because
of differential performance of the subgrade materials. This is a concern at the contact between
cuts and fills and at contacts between dissimilar materials within cuts.
Where contacts between dissimilar materials are exposed at pad or footing grade, we
recommend that the subgrade beneath the structure be overexcavated at least 1 foot below design
grade, and the overexcavation backfilled with structural fill compacted to at least 95 percent of
the MDD. The limits of the overexcavation and structural fill placement should extend at least
1 foot outside of the building footprint or footing area.
Loose or disturbed subgrade soils in footing excavations may result in increased settlement.
The native soils are susceptible to disturbance if allowed to become wet. If footings are
constructed during wet weather, concrete should be placed as soon as possible after the footings
are excavated. It also may be appropriate to place a lean concrete "mud mat" or a layer of
crushed rock in footing excavation bottoms to protect the subgrades from disturbance.
We recommend that all completed footing excavations be observed by a representative of
our firm prior to reinforcing steel and structural concrete placement. Our representative will
confirm that the bearing surface has been prepared in a manner consistent with our
recommendations and that the subsurface conditions are as expected.
G e o E n g i n e e r s ~~'~ ~ t~ `~~ `M •~ v~ v File No. 2378-032-703/040595
Lateral Load Resistance
Lateral loads can be resisted by a combination of friction between the footing and the
supporting soil, and by the passive lateral resistance of the soil surrounding the embedded
portions of the footings. A coefficient of friction between concrete and soil of 4.35 and a passive
lateral resistance corresponding to an equivalent fluid density of 300 pcf (pounds per cubic foot)
may be used for design. The friction coefficient and passive lateral resistance are allowable
values, and incorporate factors of safety of approximately 1.5.
If soils adjacent to footings are disturbed during construction, the disturbed soils must be
recompacted, otherwise the lateral passive resistance value must be reduced.
Foundation Settlement
We estimate that the postconstructionsefflement of shallow footings supported on native till
or on structural fill may range from about ~ to lh inch. Maximum differential settlement should
be less than ~,4 inch, measured along 25 feet of continuous wall footing. We expect that
settlements for these conditions will tend to occur rapidly after the loads are applied.
Immediately prior to placing concrete, all debris and soil slough that accumulated in the
footings during forming and steel placement must be removed. Debris or loose soils not removed
from the footing excavations will result in increased settlement.
FLOOR SLAB SUPPORT
Floor slabs may be supported on-grade provided that the subgrade soils are prepared as
previously recommended. Any areas disturbed by construction activities should be recompacted
before proceeding with slab construction. We recommend that slabs-on-grade be constructed on
a gravel layer to provide uniform support and to act as a capillary break. The gravel layer should
consist of at least 4 inches of clean fine gravel or crushed rock, with negligible sand or silt. A
vapor barrier should be placed over the gravel layer. We recommend that the vapor barrier be
covered with 2 inches of sand to protect it during construction and to aid in curing of the slab
concrete. This sand should not be allowed to become wet prior to casting the slab concrete,
otherwise curing of the concrete may be adversely affected.
In areas where ground water is near the surface, we recommend that underdrainage be
provided to collect and discharge groundwater from below the slabs. This can be accomplished
by thickening the gravel layer below the slabs to 6 inches, and installing a 4-inch-diameter
perforated collector pipe in a shallow trench placed below the gravel layer. The collector pipe
should be oriented along the center, long axis of the structure. The trench should measure about
1 foot wide by 1 foot deep and should be backfilled with clean gravel. The collector pipe should
be sloped to drain and discharge into the storm water collection system
site. This pipe should also incorporate a cleanout.
-~
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G e o E n g i n e e r s 11
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~~~ ~ ~ 200
JEFFERSON COUNTY
r ~~r,~?.~M~Att7a~.,D~,~ELOPMENT
~~ ~~~D
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RETAINING and SUBGRADE WALLS
• Design Parameters JEFFERSON COUNTY
SEPT. OF C E MENT
We recommend that retaining and subgrade walls be designed
pressure corresponding to an equivalent fluid density of 35 pcf. This lateral earth pressure is for
a wall with level backfill. For walls with backfill sloping up at 2H:1 V, the design lateral earth
pressure should be increased to 55 pcf.
If vehicles can approach the wall to within 1~ the height of the wall, a traffic surcharge
should be added to the wall pressure. For car parking areas, the traffic surcharge can be
approximated by the equivalent weight of an additional 1 foot of soil backfill behind the wall.
For delivery truck parking areas and access driveway areas, the traffic surcharge can be
approximated by the equivalent weight of an additional 2 feet of soil backfill behind the wall.
These recommendations are based on the assumption that any retaining walls at this project
will be provided with backdrainage and will be unrestrained against slight top rotation. If the
walls will be restrained, higher pressures will be appropriate. Walls are assumed to be restrained
if top movement during backfilling is less than H/1000, where H is the wall height.
The values for soil bearing, frictional resistance and passive resistance presented above for
foundation design are applicable to retaining wall design.
Backdrainage
The retaining walls could be exposed to water from ground or surface water sources, or
from landscape watering. As the proposed structures will likely utilize the retaining wall as
basement walls, we recommend that the buried portions of the walls be waterproofed. To reduce
the potential for hydrostatic water pressure buildup behind the retaining walls, we recommend
that the walls be provided with backdrainage. Backdrainage can be achieved by using free-
draining material or prefabricated drainage panel products, with perforated pipes to discharge the
collected water.
Free-draining material should consist of sand and gravel containing less than 3 percent
fines. The draining material should be 2 feet wide and should extend from the base of the wall
to within 1 foot of the ground surface. The free-draining material should be covered with 1 foot
of less permeable material, such as the on-site silty sand.
Prefabricated drainage panel products, such as Mirafi Miradrain 6000 (or similar material),
consist of a geotextile filter fabric bonded to a molded plastic drainage element. The drainage
panel is placed directly behind the wall, and should extend from the base of the wall to about
1 foot from finished grade. The panel should be covered with 1 foot of less permeable material,
such as the on-site silty sand.
Wall backdrains should include a perforated pipe with a minimum diameter of 6-inches.
We recommend using either heavy-wall solid pipe or rigid corrugated polyethylene pipe. We
recommend against using flexible tubing for wall backdrain pipe.
r ~, ~. ~
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i~~~ ,~.~ l ~h~rJ
G e o E n g i nee r s I Z File No. 2378-032-'t'03/OdOS95
The pipe should be installed with about 3 inches of drainage material below the pipe, or the ,
~.
drainage panel geotextile filter fabric should extend from the panel to wrap around the pipe. The
pipes should be laid with minimum slopes of one percent and discharge to appropriate disposal
points to convey the water away from the retaining walls. The pipe installations should include
cleanout risers located at the upper end of each pipe run. We recommend that the cleanouts be
provided with tamper-proof locking caps, completed within flush mounted utility boxes.
We recommend that roof downspouts not discharge into the perfo p~es~o~di~g~al~
backdrainage.
~ E ~ ~ ~ 2001
Construction Considerations
Care should be taken by the contractor during backfilling to avoi ~ ~
_____
retaining walls. Backfill placed within about 5 feet of the walls should DE ELOPMENT
operated or small self-propelled equipment. Heavy compactors or other heavy construction
equipment should not be used within about 5 feet of the walls.
Rockeries
Rockeries may be planned in areas with grade transitions. Rockeries essentially serve as
protection against erosion and minor sloughing along existing stable slopes and provide little
"retaining" support. Rockeries are best suited for use along stable slopes cut in competent soils.
When a rockery is constructed along the face of a fill embanlanent, adequate compaction of the
fill behind the rockery is critical for long-term stability; the fill should be compacted to at least
95 percent of the MDD, and the fill height should be limited to about 4 feet. Any surcharge
conditions above a rockery or seepage conditions within the fill embanlanent behind a rockery
can lead to distress or failure of a rockery-faced slope. The potential need for maintenance of
rockeries should be recognized.
We recommend that rockeries be constructed in accordance with the most current edition
of "The Association of Rockery Contractors Standard Rockery Construction Guidelines." For
planning purposes, we recommend that all rockeries be limited to a maximum height of 8 feet.
DRAINAGE
All ground surfaces, pavements and sidewalks should slope away from structures. Surface
water runoff should be controlled by a system of curbs, berms, drainage swales, and/or catch
basins, and conveyed off-site through a storm water collection system. Surface water should not
be discharged over slopes or into subdrains. Roof drains should be tightlined to discharge into
the storm water collection system or to an appropriate outlet structure. Roof drain water should
not be discharged to footing drains.
Footing, wall and underslab drainage systems may be needed depending on final design
grades and localized ground water conditions. Footing drains with an invert elevation at the base
of the footing are generally effective to limit water seepage into crawlspaces. The crawlspace
t~
'~ ~4
v3~ JJ 1 ~y~~`
G e o E n g i n e e r s 13 Filc No. 2378-032-703/040395
should not be excavated deeper than the invert of the footing drains, or additional areal drains
_ will need to bt provided.
Permanent drainage systems should be installed at the top and/or bottom of cut and fill -
slopes to intercept surface runoff and to prevent it from flowing in an uncontrolled manner across
the slopes.
PAVEMENT DESIGN AND SUBGRADE PREPARATION
Parking area and access drive pavement subgrades should be prepared as described
previously in the EARTHWORK section of this report. We recommend the pavement in areas
to be used exclusively by automobiles consist of 2 inches of Class B asphalt concrete over 4
inches of crushed surfacing base course. For pavement in access roads and truck parking areas,
we recommend providing 3 inches of asphalt concrete over 6 inches of crushed surfacing base
course. The base course should be compacted to at least 95 percent of the MDD.
The crushed base course should comply with Washington Department of Transportation
Standard Specifications for Road, Bridge and Municipal Constructio 3.9 3
"Base Course. " The asphalt concrete materials and procedures shout p~w~ s~;c~ic~io~
in that document for Class B Asphalt Concrete Pavement.
E ~ ~ ~ ~0~~
LIMITATIONS '
We have prepared this report for use by Pope Resources and m tubers o~~eR ~t1tn
ata d DEPT. OF COM N(~ DEV Q MENT
involved in the Port Ludlow Division 7 Development. The d an
to prospective contractors for bidding or estimating purposes; but our report, conclusions and
interpretations should not be construed as a warranty of the subsurface conditions.
Our scope does not include services related to construction safety precautions and our
recommendations are not intended to direct the contractor's methods, techniques, sequences or
procedures, except as specifically described in our report for consideration in design.
The project was in the design development stage at the time this report was prepared. We
expect that further consultation regarding specific design elements will be necessary. If there are
any changes in the grades, location, configuration or type of construction planned, the
conclusions and recommendations presented in this report might not be fully applicable. If such
changes are made, we should be given the opportunity to review our conclusions and
recommendations and to provide written modification or verification, as appropriate. When the
design is finalized, we recommend that we be given the opportunity to review those portions of
the specifications and drawings that relate to geotechnical considerations to see that our
recommendations have been interpreted and implemented as intended.
There are possible variations in subsurface conditions between the locations of the
explorations and also with time. Some contingency for unanticipated conditions should be
included in the project budget and schedule. We recommend that sufficient monitoring, testing
and consultation be provided by our firm during construction to confirm that the conditions
~l'~ .y~0
~/uL 'J~J ~ ~^''
G e o E n g i n e e r s 14 Filc No. 237$-032-T03/040593
encountered are consistent with those iixiicated by the explorations; to provide recommendations
r for design changes should the conditions revealed during the work differ from those anticipated;
and to evaluate whether or not earthwork and foundation installation activities comply with the
contract plans and specifications.
Within the limitations of scope, schedule and budget, our services have been executed in
accordance with generally accepted practices in this area at the time the report was prepared. No
other warranty, express or implied, should be understood.
~ O -
We appreciate the opportunity of working with you on this projeci. If you have any
questions or need further assistance, please call.
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Documecu ID: 2378032R.R
Attachments
Yours very truly,
GeoEngineers, Inc.
__--
Thomas V. May
Geotechnical Engineer
~•
Gary W. Henderson
Principal
A~}D~YOR'S NOTE: '-`- .'
_ e~
Four copies submitted
cc: Pope Resources
781 Walker Way
Port Ludlow, Washington 98365
Attn: Mr. Ray Welch
U ~'J
~E8 1 ~ 2001
~~~~~~~fl~ ~~u~TY
p~FT. Of COMMUN~n DEVELOPMENT
C~Ay
d e o E n g i nee r s 1$ File No. 2378-032-'Pp3l04U59S
Foundation
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Horizontal Setback
Dense Native Soil or
Properly Compacted Structural Fill
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FOUNDATION DETAIL
FIauRE 2
SOIL CLASSIFICATION SYSTEM
MAJOR DIVISIONS
GRAVEL
COARSE
GRAINED
SOILS More Than 5096
of Coarse Fraction
Retained
on No. 4 Sieve
More Than 5096
Retained on SAND
No. 200 Sieve
More Than 5096
of Coarse Fraction
Passes
No. 4 Sieve
FINE SILT AND CLAY
GRAINED
SOILS
liquid limit
less Than 50
More Than 5096 SILT ANO CLAY
Passes
No. 200 Sieve
liquid Limit
50 or More
HIGHLY ORGANIC SOILS
NOTES:
1. Field classification is based on visual examination of soil
in general accordance with ASTM 02488-90.
2. Soil classification using laboratory teats is based on
ASTM D2487-90. '
3. Descriptions of soil de a based on
interpretation of blow d~c , ~(i;'Lal(~p~arl~e
soils, and/or test data. ~ !~~ l~r ~~CC
FED ~ ~~ 2~,Q~
QEPT. OF COMMUNITY pEVEL PMENT
Geo ~ ~ Engineers
.i
GROUP
SYMBOL
CLEAN
GRAVEL GW
GP
GRAVEL
WITH FINES GM SI
GC C
CLEAN SANG SW w
SP
SANG
WITH FINES SM St
GROUP NAME
WELL-GAAOEO GAAVEI, FINE TO COARSE GRAVEL.
POORLY-GRADED GRAVEL
lTY GRAVEL
LAYEY GRAVEL
Ell-GAAOEO SAND, FINE TO COARSE SAND
POORLY-GRADED SANG
LTY sANo
SC CLAYEY SANG
INORGANIC ML SILT
CL CLAY
ORGANIC OL ORGANtC SILT, ORGANtC CLAY
INORGANIC MH SILT OF HIGH PLASTICITY, ELASTIC SILT
CH CLAY OF HIGH PLASTICITY, FAT CLAY
ORGANIC OH ORGANIC CLAY, ORGANIC SILT
PT PEAT
•
SOIL MOISTURE MODIFIERS:
Dry - Absence of moisture, dusty, dry to the touch
Moist - Damp, but no visible water
Wet - Visible free water or saturated, usually soil is
obtained from below water table
~~~ `~5 ~ ~~~t ~ ~~~
SOIL CLASSIFICATION SYSTEM
FIGURE 3
LOG OF TEST P1T
DEPTH BELOW
OROUNO BURFACE
(PEETI
8011 GROUP
CLA881FICATION
SYMBOL
DE8CRIPTION ,
0.0 - 0.4
0.4 - 1.3
1.S • 4.3
a.s - s.s
S.S - 9.0
0.0 - O.S
O.S - 1.0
1.0 - 4.S
4.S - S.S
S.S - 10.0
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JEFFERSON COUNTY
DEPT. OF COMMUNfTY DEVELOPMENT
THE DEPTHS ON THE TEST PIT LOGS. ALTHOUGH SHOWN TO 0.1 FOOT, ARE BASED ON AN AVERAGE OF
MEASUREMENTS ACROSS THE TEST PTT AND SHOULD BE CONSIDERED ACCURATE TO O.S FOOT.
Geo Engineers
LOG OF TEST PIT
FIGURE 4
TEST' PIT 1
4" duff
SM Reddish silty sand with gravel (medium dense. moist)
SP Yellowish rind and gravel (dense. moist)
SP Gray very dense sand with gravel
SM Gny silty sand with gravel (very dense, moist) (glacial till)
Test pit completed at a depth of 9.0 feet on OZ/Z3/9S
Slight ground water secpage observed at a depth of S.S feet
No caving observed
TEST PTT 2
Fill -silty sand and grave!
Duff
SP Yellowish sand and gravel (medium dense to dense. moist)
SP-SM Gray weathered till
SM Gray silty sard with gravel (very dense, moist) (glacial till)
Test pit completed at a depth of 10.0 feet on 02/23/95
Slight ground water seepage observed at a depth of 8.0 feet
No caving observed
1 11 r
V O t. ~./ ~ J 1 ^1 v L
LOG OF TEST PIT
DES sE<ow 801 aROUP
GROUND 8URFACE CI.A881fICATiON
IFEE~ SYM80L
0.0.0.4
0.4 - 1.3
1.3 - 3.0 ~
S.0 - 10.0 sM
0.0 - 0.4
0.4 - 1.S SM
1.5 - 4.0 SP
4.0 - 8.S ~
0.0 - 0.4
0.4 - 3.0 ~
3.0 - 9.0 SM
DESCRIPTION
4" duff
Rcddish to yeQowis6
Yellowish sacd with gravel (dense, moist)
Gray silty sand with gavel (very dense, moist) (glacial till)
Test pit completed :< a depth of 10.0 feet on 02/23!95
Slight ground water seepage observed at a depth of S.0 feet
No caving observed
TEST PTT 4
4" duff
Rcddish silty sand with gavel
Yellowish brown sand with fine but mostly coarse gravel (dense to very dense,
moist) .
Gray silty sand with gravel (very dense, moist) (glacial till)
Test pit completed at a depth of 8.5 feet on 02123/95
Slight ground water secpage observed at a depth of 4.0 feet
No caving observed ~ ~ ~ q
~t1!
TEST PTT 3
~~ ~~ ~~0
4" duff
Yellow sand with gravel (dcase, moist) DEPT, 0 F C C M M UON TY DEVELOPMENT
Gray silty sand with gravel (very dense, most ac
Test pit completed at a depth of 9.0 feet on 02/23/95
Slight ground water seepage observed at a depth of 3.0 feet
No caving observed
THE DEPTHS ON THE TEST PTT LOGS, ALTHOUGH SHOWN TO 0.1 FOOT. ARE BASED ON AN AVERAGE OF
MEASUREMENTS ACROSS THE TEST PTT AND SHOULD BE CONSIDERED ACCURATE TO 0.3 FOOT.
Geo Engineers
LOG OF TEST PIT
FIGURE 5
V0~ ~J~J ~ '~-~
LOa OF TEST PIT
0~ eE~ow SOtL GROUP
tIROUNO BURFACE CLA88tFICATION
(~~ 8YMBOL OEBCRIPTION
0.0 - 0.6
0.6 - 3.0 SM
3.0 - ?.0 ~
TEST PIT 6
6' duff
Brown silty sand with gravel (loose to medium dense, moist)
Gny silty sand with gravel and occasional cobbles (very dense) (till)
Teat pit complead at a depth of 7.0 feet on 0?./23/95
No ground water seepage observed
No caving observed
~ L ~~ ~ ,.~ 2~Q~
JEFFERSON CQUNTY
DEPT. OF COh1MUNITY DEVELOPMENT
THE DEPTHS ON THE TEST PTT LOGS, ALTHOUGH SHOWN TO 0.1 FOOT, ARE BASED ON AN AVERAGE OF
MEASUREMENTS ACROSS THB TEST PTT AND SHOULD BE CONSIDERED ACCURATE TO 0.5 FOOT.
Geo Engineers
LOG OF TEST PIT
FIGURE 6
~~.-~. ~i~ir~ ~ ~ .. ~5~
_~,
~ 1 SECTION 9: GEOLOt3ICALLY HAZARDOUS AREAS
I 2 .
3 Subsections:
4
5 9.10 Introduction D
6 9.20 Purpose
. 7 9.30 Classification/Designation SEE ~ ~ 2001
8 9.40 Applicability and Waivers
1 9 9.50 Protection Standards ~E~FERSON coucsN
1 ons DEVELOPMENT
10 9.60 Conditi pEpT. pF COMMUNITY
11
12
13 9.10 Introduction
14
15 Geologically hazardous areas in Jefferson Coundwater thatamaercombine
16 slope, soil type, ologic material and grou y
17 to create problemsith slope stabi~ity,.erosion, and water quality
18 during and after construction or during natural events such as
19 earthquakes or severe rainstorms. The following regulations will
20 ide development in these critical areas.
21
22
23 9.20 Purpose
24
25 To maintain the natural integrity of•geologically hazardous areas and
26 their buffers in order to protect adjacent lands from the impacts of
1 ence excessive erosion, and to safeguar
27 landslides, mudslides, subsid ,•
28 the public from these threats to life and property. The purpose of
29 this ordinance section is, however, subordinate to the overall purpos
. ~ 30 of this ordinance as stated in §1.201.
31
32
33 9.30 ClassificationlDesictnation
34
35 9.30 Classification: For the purposes of this ordinance,
36 geologically hazardous areas shall be classified based upon a
landslide and seismic hazard.
37 combination of erosion,
38
39 es t on: The following erosion, landslide and seismic
x.302 D ana
40 hazard areas shall be subject to the standards of this section.
41
42 1. erosion haz,~ ard_ areas: ~ ~-~ ~ .,
43 exes described and
44 a. Areas containing soils or soil compl
45 mapped within the United States Department of
46 AgriculturejSoil Conservation Service ~,o u~veY
as having a severe or very severe
47 Je!!e sen
48 erosion hazard potential:
49
50 2. *~MaQ " ao t~,~~ard area: Areas potentially subject to mass
51 movement due to a combination of geologic, topographic and
52 hydrologic factors including:
1
41
V p
,,
X
1 5. Washington State Department of Natural Resources, Geologic
Maps of Eastern Jefferson County, ,~ ~ ~
2 .- s ---~j ~, ~ ~ i n Eastern Jefferson _ County •
3
4
United States Department of the Interior, USGS ua Maps_
5 6.
6
~ The maps prepared by the County
g 4~ 4 eo g c _~
303 have been
9 using the identification sources listed in subrec~otnre~ulatory
10 produced for informational purposes only and a g
11 devices fortaing an integral part of this ordinance.
12
13
14 9.40 Applicabi1ity and Waivers
nrr>> i cab. ~lty • .. `' .:. ~ . ,.~ ..
17
Critical area review shall .be required for any triggering
18 1.
19 application for a project on a parcel of real property
20 containing a designated erosion or landslide hazard area,
21 unless waived under subsection 9.402, below.
22
2, Critical area review shall be required where a triggering
23
a lication is made for construction of any publicly owned
25 facility in a designated seismic hazard area.
26
27 1 when
28 9.40? Waivers: The provisions of this seceifollowin notoathey
29 the applicant demonstrates either one of th g
30 satisfaction of the Administrator:
31
32 1. All building sites and project related improvemen s
(including any clearing or grading activity) will be located
33
34 outside of any designated geologic hazard area or its
35 buffer.
36 eolo is information available for the
37 2. There is adequate g g
38 project area to determine the impacts of the proposed y' and
39 development and appropriate mitigating measures, if an ,
40 ~ the proposal would not cause adverse geological impacts on
41 or off the project site.q,.
42 Co d'tions:~ In or er~to~s~cure compliance with, of
43 x.403 Waiver
44 subsection 9.402, above, the Administrator'`Yma_y~:require conditions
which ensure that no portion of the`~-roposed development will
45 approval
encroach upon a designated geologic hazard area or itedbtfofeo'tional
46 include, but are not limit p
47 Conditions of approval may
8 conservation easements; the graphic portrayal of building envelopes
4
and related improvements on the face of final short ns•land noticesnto
49
50 binding site plans; drainage and erosion control p a
51 title.
52 (~
(~ t5
JEFFERSON COUNTY S C -~ ~~ Q (00
DEPT. OF COMMUNITY DEVELOPMENT ~ p1..,,, 7
~ ~ , .
i
I
--
1
i.
1~
'~:
r
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
d. Clearing for roads and utilities shall remain within
construction limits which must be marked in the field
prior to conmtencement of site work; and
e. The authorized clearing for roads and utilities shall bE
the minimum necessary to accomplish project specific
engineering designs and shall remain .within approved
rights-of-way.
2. The following provisions regarding grading shall apply:
a. An applicant submitting a triggering application shall
also submit, and have approved, a grading plan, as
specified in section li of this ordinance, when the
triggering application involves either of the following:
(i) The alteration of a geologically hazardous area
its buffer; or
(fi) The creation of a new parcel within a known
geologically hazardous area;
b. Excavation, grading and earthwork construction regulatec
under this section shall only be allowed from April 1 tc
November 1, unless the applicant demonstrates that such
activities would not result in impacts contrary to the
protection requirements herein.
9.504 V~aetation Retention: The following provisions regarding
vegetation retention shall apply:
1. .. During clearing for roadways and utilities, all trees and
understory lying outside of approved construction limits
shall be retained: Provided that understory damaged Burin
approved clearing operations may be pruned (see also,
subsection 9.503 (1) (c) , above) .
2. Damage to vegetation retained during initial clearing
activities shall be minimized by directional felling of
trees to avoid critical areas and vegetation to be retaine
3. Retained trees, understory and stumps may subsequently be
cleared only if such clearing is necessary to complete the
proposal involved in the triggering application.
9.505 uffer Marking: The location.of the outer extenioWS•landslid
hazard area buffers shall be marked in the field as fol
1, A permanent physical separation along the boune~anentlhe
landslide hazard area shall be installed and p Y
maintained. Such separation may consist of logs, a tree c
hedge row, fencing, or other prominent physical marking
approved by the Administrator.
V
D
~E~ 1 ~ 201
JEFFERSON COUNTY
DEPT. OF COMf~1UNITY DEVELOPMENT
r ~~l . ~.: ~E~2
~~o~ •~~)
a_
0
1 ~. SOB „~ aren~.q Buffer Widths: Th® Administrator may incr®ase tt.
2 standard landslide hazard area bu!!er width specified in subsection
3 9.506.6, above,~'when a larger bulPer is necessary to protect the
4 ;propassd protect and the landslide hazard area. This datsrn-ination
5 s1~a~1:<<bs made only when the Department, at its own expanse,
6 ~s~o~atrates any one o!_the following through appropriate
~
7 _
doaumentat f on
8
g 1. The landslide hazard area is unstable and active.
10
11 .2. The adjacent land is susceptible to severe landslide or
12 erosion, and erosion control measures will not effeetivel
13 protect the proposed project or the landslide hazard area
14
15 3. The adjacent land has minimal vegetative cover.
16
17 g-sn9 Ge otechnical Report:
18
19 1: An applicant submitting a triggering application shall
20 submit, and have approved, a geotechnical report, as
21 specified in section 11 of this ordinance,~when the
22 triggering application involves any of the following:
23 a. The alteration of a landslide hazard area or its buffer
24 b. The creation of a new parcel within a known landslide
25 hazard area.
26 c. The construction of a publicly owned facility in a
27 designated seismic hazard area.
28
29 2. Where a geotechnical report is required for a landslide
30 hazard area, the triggering application shall not be
31 approved unless the geotechnical report certifies all of
32 following: _
33 a. There is minimal landslide hazard as proven by a lack c
34 evidence of landslide activity in the vicinity in the
35 past;
36 b. An analysis of slope stability indicates that the
37 proposal will not be subject to risk of landslide, or t
38 proposal or the landslide hazard area can be modified s
39 that hazards are eliminated;
40 c. The proposal will not increase surface water discharge
41 sedimentation to adjacent properties beyond
42 predevelopment conditions;
43 d. The proposal will not decrease slope stability on
44 adjacent properties; and
45 e. All newly created building sites will be stable under
46 normal geologic conditions (if applicable).
47
48 3. Where a geotechnical is required for a seismic hazard area
49 the triggering application shall not be approved unless tY
50 geotechnical report demonstrates that the proposed project
51 will adequately protect t e public safety.
5 2 Q (1jl ~ .
V
D
~ j
JEFFERSON COUNTY .
,
DEPT. OF COMMUN~n DEVELOPMENT ;~ ,
~o~
Wben recorded return to:
ton Rose 4CH~3~
Olympic Resource Management
PO Hox 1780
Poulsbo, WA 98370
.. ~ ~~~ ..
.,.
,.. ~ .
.. ~
~~~; .. " ~d~trJ
:..: ~.., _ ..~~ C r
9 ~~'~~ .
P ~.
JE~FER £ ~ 1 ^ ~ UNT YTS ~`LD
a UOITOA
8Y EPUTY
Revised Report Addendum
To Supplement GeoEngineer's Geoteclsnical Report
For Port Ludlow No. 7
Reference to Related Documents:
A Geotechnical Report dated April S, 1995, covering port Ludlow No. ?recorded at Volume
557, Pages 933 through 964, records of Jefferson County, Washington, wader. Jefferson Coon
Auditors File No. 393727. ~
Grantor: Pope Resources, A Delaware Limited Partnership
Grantee: Pope Resources, A Delaware Limited partnership
Abbreviated Legal Description:
Portions of SE 1/4 of Section 8, SW 1/4 of Section 9, NW 1/4 of Section 16, and NE 1/4 of
Section 17, Township 28 North, Range 1 East, W.M., Jefferson County, Washington.
Assessor's Property Tai Parcel /Account Numbers:
~ ~ X003
JEFFERSON COUNTY
DEPT. QF COM~v1UNfTY DEVELOPMENT
YJL (~~ V~vr~
t
{
February 11, 1997
Pope Resources, Inc.
P.O. Box 1780
Poulsbo, Washington 98370
~ lYi - ~
Coasultl~ ~
and Geosclendst
Offices in Waahin~
Oregon, and Alaslc
Attention: Mr. Jon Rose, P.E.
Revised Report Addendum
Port Ludlow Division 7
Port Ludlow, Washington
File No. 2378-041-03 ~.
INTRODUCTION
This letter supplements GeoEagineers' April S, 1995 geotechnical report for the subject site
to include criteria for on-site dispersal and 'infiltration trenches for roof drains and clarify building
setbacks from steep slopes. We understand individual lot dispersal trenches are proposed for Lot
numbers 14 through 22. The dispersal trenches will be constructed in general accordance with
the WDOE Stonawater ~ Manual (Washington State Department of Ecology Stormwater
I/iaaage:nent Manual for the Puget Sound Basin) criteria and the attached drawing prepared by
WestSoun~d Engineering. Individual lot infiltration trenches are proposed for Lot numbers 1
through 7, also to be constructed is general accordance with WDOE Stormwater Manual criteria.
Clarification is requGSted regarding building setbacks from steep slopes for Lots 14 through 22.
DISPERSAL TRENCHES
Dispersal trenches are in our opinion acceptable for discharge of roof drainage on individual
lots 14 through Z2 and lots 1 through 7. The trenches should be constructed parallel to the slope
contours. Care must be taken so that the system is properly constructed and that flow is evenly
dispersed on vegetated slopes. We recotnm~tid dispersal trenches be setback a horizontal distance
of at least 25 fret from slopes steeper than 3:1 (horizontal to vertical), or the roof drains may be
tightlinod to a dispersal trench located at the base of the slope.
~~c~a~
~~ d
~~ ~ ~- ~. ~ ~ ~- X001
~,o~ ,~, s~ ~o
""w"' ~'~ aR40Z JEFFERSON COUNTY
`~. pEpT, OF COM~+1UNlTY pEVELOPMENT
von 5i~ ~«-,~4$~3
t •
•f
INFILTRATION TREN
CHES
lnliltratioa trenches coastiueted is genarai accordance with WDOB St
criteria and the design Pnp~ by WestSound oraswater I~iaau~
1SS through 169 of the Jett ~b~~ as rOCO~ in Volume 563, p~ga
anon County Auditor ue in our opinion generally spprop~ foi
di~~posal of roof dninsge on individual lots 1 through ~, The
puaUel to the : sh~id ba conativc;t~
Lope contours and installed in aativa ground which has not been
eacatvated. Wa recommend iafiltration filled or
ss~ ba set back a distance of at least ZS feet t3rom
slopes steeper than 4:1(~~~ to vertical), or the roof drains may bed •
trenches at the base of the slope. 8htli~d to infiltrauoa
. 6UILDINQ SETBACKS
A distincx lice, to be shown on the tinai plat. was act ra:o
Wa t~eoomaxndad a setback aided in :our report.
d~aoe from the edge of the footigg to the gtbuad a~srfaoe a~asured
on a level line. For slopes b~weCII 15 sad 30 percpnt, the setback distance is 8
be u~aed to 12 feet for, sI inclined ~~ We
~ between 30 percent and SO
percent. and 20 fact for slopes steeper than 50 p~erceat, The sexback can be shown onl
house footpriu has been located, Y after the
~ O
D
~ ~~ ; 2QO~
JEFFERSON COUNT`'
pT. OF COMMUNIT`{ DEVEI.OP~T
DE
~: 535 x.,494
E
..•
We trust the foregoing meets your present needs, should you hiv~a say questioas or aced
additional information, please caU. ~~
GI~tS:oWH:vc
Dowmeat ID: 237E041 R.ADD
Attachment
cc: Westsound Engino~xi~g
Attention: Mr. Craig Baldwin
. ..
Yours very truly,
GeoEngineers, Inc.
l
Gory H. Squires
Senior Engineer w
Gary w. Henderson. P.E.
Principal .
_,,,_,___------p-~ n ~ .
~ ~a U
D
. s~.~FE~saN .~ Q~ E aP~~~T
DEPT. GF GGMMU
~~ 595 ~,-485
awwES 10/23/9 ~'
•4
. r. ,
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4
•
~
Port Ludlow No. 7
R~~F nc~wnraw-rrr en~ne•••~ -,
LEVEL OUTLET
ROCK
~ M+ .
T~r~X~~x
• SLOPE -.y.
i
srxucTVxE
NOTE: OF 10 LF OF
TRENCH PER EACH
7S0 SQ. FT. ROOF
AREA DRAINED.
PLAL~I V~t':W nF R„ n~
NOTE: NOT TO SCALE
~--- 25' MIN. TO -._.~
PROPERTY LINE
(VEGETATED)
~-- 2' X 10'
LEVEL
TRENCHES
~`' SMALL CATC
. ~~[~~~~
D .
~ ~ ~ ~ ~0~1
JEFFERSON CO NTY
DEPT. OF COMMUNIN DEVELOPMENT
1/ t
.i
8 ~CQPY
~a.~-,~
When recorded return to:
<~ 4a1f3
Jon Rose
Olympic Resource Management
PO Box 1780
Poulsbo, WA 98370
; ~r . ~~~,
~ n ~ ~
G . _^~
~ ::~~..~.;r c:
9 ~C
~I ~P t
5
D0:`~: ;.. ~ .. T: tzLD
JEFFERS~ri ~~UN7 Y QUDtTOR
8Y EPUTY
Reviled Report Addendum
To Supplement GeoEngineer's Geotechnical Report
For Port Ludlow No. ?
Reference to Related Documents:
A Geotechnical Report dated April 5, 1995, covering Port Ludlow No. 7 recorded at Volume
557, Pages 933 through 964, records of Jefferson County, Washington, under Jefferson County
Auditor's File No. 393727.
Grantor: Pope Resources, A Delaware Limited Partnership
Grantee: Pope Resources, A Delaware Limited Partnership
Abbreviated Legal Description:
Portions of SE 1 /4 of Section 8, S W 1/4 of Section 9, NW 1 /4 of Section 16, and NE 1 /4 of
Section 17, Township 28 North, Range 1 East, W.M., Jefferson County, Washington.
Assessor's Property Taa Parcel /Account Numbers:
-- a ~
~~~
s,
LF
~EFFEasoN couNrr
CON~MIJNt~Y DEV~.~e NT
DEPT. OF
~QL ~~ Vrv~~~
1
February 11, 1997
Conanldgg 8ogii
and Geoadeatlat
• Offices in Washing
Pope Resources, Inc. Oregon, and Alask
P.O. Box 1780
Poulsbo, Washington 98370
Attention: Mr. Jon Rose, P.E.
Revised Report Addendum
Port Ludlow Division 7
Port Ludlow, Washington
..~. -
File No. 2378-041-03
INTRODUCTION
This letter supplements GeoEngineers' April S, 1995 geotechnical report for the subject site
to include criteria for oirsite dispersal and infiltration trenches for roof drains and clarify building
setbacks from steep slopes. We understand i>~dividual lot dispersal trenches are proposed for Lot
numbers 14 through 22. The dispersal trenches will be constructed in ge~ral accordance with
the WDOE Stormwater ~ Manual (Washington State Department of Ecology Stormwater
Management Manual for the Puget Sound Basin) criteria and the attached drawing prepared by
WestSound Engineering. Individual lot infiltration trenches are proposed for Lot numbers 1
through 7, also to be constructed in general accordance with WDOE Stormwater Manual criteria.
Clarification is requested regarding building setbacks from steep slopes for Lots 14 through 22.
DISPERSAL TRENCHES .
Dispersal trenches are in our opinion acceptable for discharge of roof drainage on individual
lots 14 through 22 and lots 1 through 7. The trenches should be constructed parallel to the slope
contours. Care must be taken so that the system is properly constructed and that flow is evenly
dispersed on vegetated slopes. We recomm~ttd dispersal trenches be setback a horizontal distance
of at least 25 feet from slopes steeper than 3:1 (horizontal to vertical), or the roof drains may be
tightlined to a dispersal trench located at the base of the slope. ~ c~.
~4
~~
D
u~~ Nz
~~ ~ SE~~E ~~~ ~ pEVE`~pN1E
1101 Fa~v+aeu Ave., Suue Z00 M
DEPT ~ ~F C~
'~..r,n,. Q/A C~{QZ
~-Oe. ~~ !'r-.r ~~
w
tNFiLTRATION TRENCHES
Infiltration tr~enchea conatzvcted in general accordance with WDOB Storaiwater Manual
criteria and the design prepared by WestSound l3ngineering as recorded in Volume 563, page
155 through 169 of tha Jefferson County Auditor are in our opinion generally appropriate fot
disposal of roof drainage on individual lots 1 through 7. The should be constructed
parallel to the slope contours and installed in native ground which has not been filled or
excavated. We recommend infiltration trenches be set back a distance of at least ZS feet from
slopes steeper than 4:1(horizontal to vertical), or the roof drains may be tightlinod to infiltration
trenches at the base of the slope.
6UILDING SETBACKS
A distinct sexbaclc lip, to be shown on the final plat, was not ret:o®mended in o_ur report.
We reoommeaded a a~etback distance from the edge of the footigg to the gtbund surface measured
on a level tine. For slopes between IS and 30 percent, the setback distance is 8 feet. ~e
rccoannend this distance be increased to 12 foes for.slopes inclined betwcea 30 percent and 50
percent, and 20 feet for slopes steeper than 50 percent. The setback can be shown only after the
house footprint has been located.
~ O -
JEFFERSON COUNTY
DEPT. OF CO~MUN~N DE~~IECOPMENT
.o: 535 x.,484
...
We trust the foregoing meets your present needs, should you have say questions or need
additional information, please caU.
cxs:~iwx:~~
Dowment ID: 2378041R.ADD
Attactunent
cc: Westsound Engineering
Attention: Mr. Craig Baldwin
..
Yours very truly,
GeoEngineers, Inc.
r
~~
Garry x. Squires
Senior Engineer Y•
Gary W. Henderson, P.E.
Principal .
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ROOF DOVYNSP~UT DIVERSION TRENCH
LEVEL OUTLET
-ROCK
i
Z4- M ~
TIZFNCH X-SECTION
SLOPE ---r.
NOTE: OF 10 LF OF
TRENCH PER EACH
750 SQ. FT. ROOF
AREA DRAINED.
PLAN ~TIEW OF ROOF
NOTE: NOT TO SCALE
25' MIN. TO -----~
PROPERTY LINE
(VEGETATED)
2' x l o'
LEVEL
TRENCHES
SMALL CATC
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