HomeMy WebLinkAboutMEP2002-00039 - MEP Permit / Conditions - 8/1/2002 MASON COUNTY
PUBLIC WORKS DIRECTOR/COUNTY ROAD ENGINEER
Shelton,Washington 98584
DATE: Auizust 1st, 2002
INTER-DEPARTMENTAL COMMUNICATIONS
TO: Grace Miller, DCD—Shoreline Planner
FROM: Alan A. Tahja, P/W- Co. Hydr. Engr. WO#PLG-02
SUBJ: Geo-Tech Report Review NAME: McNeely SFR k Harstine Island
MEP2002-00039, ENF2002-00050
Grace,
The geotechnical report prepared for the Daniel McNeely activities at Nicole Lane, Harstine
Island, has been received and reviewed by Public Works.
The report conforms to accepted standards of engineering/geotechnical principles and practices
and appears in compliance with requirements of DCD for geotechnical reporting.
Recommendations contained in the report should be made conditions of approval for the
proposed development of the property. Included in the recommendations is a 30' minimum
building setback from the shoreline slope, and a recommendation that downspout and parking
area runoff be tightlined to existing stormwater control features. These recommendations need to
be incorporated into the site's development designs,
The engineer has indicated that building setbacks need to be observed from landslide hazard
areas, and in other portions of the report, indicate,that they define hazard areas as having slopes
exceeding 30%. Since the engineer's hazard criteria appears to differ from the County's
thresholds, and because County staff notes indicate potential problem areas not identified in the
report, I recommend requiring the engineer's recommendation that they be part of the
development process (including their written acceptance of the final building location, and any
other certifications by the engineer the planning department may feel are necessary to ensure that
the project'proceeds within County requirements, and the engineer's recommendations)be
required as part of permit issuance.
Within these conditions,the project should be allowed to proceed. Please feel free to contact me
at County extension 461 if you have any questions regarding these comments, or if you feel any
features need further discussion or attention.
S' -erely
A an A. Tahj a
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Geological Report
For Construction
Tax Parcel #22026-10-90050
Mason County, Washington
Prepared For:
Daniel McNeely
By:
Geotechnical Testing Lab
Olympia, WA
With:
Spears Engineering & Technical Services
May 13, 2002
GEOTECHNICAL
TESTING LABORATORY
DANIEL& MARIANNE MCNEELY
22521 125TH PL. SE
KENT, WA 98031-3742
Re: Geotechnical Report
Parcel#22026-10-90050
Mason County,WA
INTRODUCTION
This report summarizes the results of our geotechnical engineering services for the proposed home to be located on
the above referenced property in Mason County. The location of the site is shown relative to the surrounding area on
the Vicinity Map, Figure 1.
Our understanding of the project is based on our discussions and site meeting with you, our review of the site and
explorations. We understand that the rectangular shaped site is to be developed as a home site with associated
outbuildings, pavement areas and utilities. The site will be accessed by a driveway from Nichole Road. Storm water
runoff from the site, roof and hard surfaces, will be collected and directed to on-site retention facilities. The general
layout of the site is shown on the Site Map,Figure 2.
We further understand that very little additional grading is required at the site to reach design grade. In general,
grading will consist of the excavation of the foundation in the level portion of the site and no structural fill is
_. anticipated. We understand that the site will be served by local utility companies.
The sloping portion of the site has angles that are greater than 45 percent. Mason County therefore requires that a
_ geotechnical report be prepared in accordance with the Critical Areas Ordinance.
The purpose of our services is to evaluate the surface and subsurface conditions at the site as a basis for providing
_ geotechnical recommendations and design criteria for the project and to satisfy the requirements of the Mason County
Critical Areas Ordinance. Geotechnical Testing Lab is therefore providing geologic and hydrogeologic services for
the project. Specifically, our scope of services for this project will include the following:
1. Review the available geologic, hydrogeologic and geotechnical data for the site area.
2. Conduct a geologic reconnaissance of the site area.
3. Explore the shallow subsurface conditions at the site by monitoring the excavations on site.
4. Evaluate the landslide and erosion hazards at the site per the Mason County Critical Areas Ordinance
regulations.
5. Provide geotechnical recommendations for site grading including site preparation, sub grade preparation, fill
placement criteria(including hillside grading), suitability of on-site soils for use as structural fill,temporary
and permanent cut and fill slopes, drainage and erosion control measures.
-r 6. Provide recommendations and design criteria for the structural foundation and floor slab support, including
allowable bearing capacity, sub-grade modulus, lateral resistance values and estimates of settlement.
10011 Blomberg Street SW, Olympia, WA 9851.2
_ - Phone#: (206)754-4612 Fax#: (206)754-4848
i
GEOTECHNICAL
TESTING LABORATORY
7. Provide recommendations and design criteria for design of conventional retaining walls, including backfill
and drainage requirements, lateral design loads, and lateral resistance values.
8. Provide our opinion regarding the feasibility of the location/construction of the storm water outfall across a
portion of the steep bluff.
9. Provide preliminary geotechnical recommendations regarding the construction of the stormwater outfall.
SITE CONDITIONS
SURFACE CONDITIONS
The proposed building site is located on the east side of Peale Passage in the Puget Sound glacial lowland area. The
site is situated in an area of slight development. The site is bounded by a home on the north side of the property.
The proposed building layout of the site is shown on the Site Plan,Figure 2.
We conducted a reconnaissance of the site area and monitored the exposed bluff and excavations dug for septic test
pits at the site. Elevations in the site area range from approximately 0 feet in the west, along the shore, to 90 plus ft.
on Nichole Lane in the east. The majority of the site is located in the sloping portion between the level building area
and Nichole Lane. A localized area in the western portion of the site steeps to between 45 and 90 percent. This area
is outside of the proposed development area.
We observed some evidence of erosion. Surficial sloughing and soil movement was observed on the steeper portions
of the site adjacent to the shoreline. No evidence of deep-seated slope instability was observed in the site area at the
time of our site visit.
The site is vegetated with fir, cedar and madrona trees. A moderate to dense understory consists of grass, brush,
young alder trees, salal and Oregon grape with local areas of huckleberry, and blackberry.
Evidence of surface water flow was observed in the site area at the time of our reconnaissance. The general
topography of the site area indicates that the site drains towards the west and Peale Passage.
SITE GEOLOGY
The site is generally situated within the Puget Sound glacial lowland area. The existing topography, as well as the
surficial and shallow subsurface soils in the area, are the result of the most recent Vashon stade of the Fraser
glaciation that occurred between about 12,000 and 15,000 years ago, and weathering and erosion that has occurred
since. A description of the surficial soils is included in the"Site Soils" section of this report.
In general, Vashon glacial till underlay the entire site.
SITE SOILS
The Mason County Soils Conservation Survey (1960)has mapped the site soils as Harstine gravelly sandy loam.
Harstine soils typically form in sandy glacial till areas and are described as having a moderate permeability and a
moderate erosion hazard. These soils are typically classified as a"Group C"relative to surficial runoff.
10011 Blomberg Street SW Olympia, WA 98512
Phone#: (206)754-4612 Fax#: (206) 754-4848
i
GEOTECHNICAL
TESTING LABORATORY
We observed some active erosion where clearing activities had taken place but a silt fence had been put in place and
I straw was spread over the exposed ground as well as seed. Also quarry spall had been placed in the drainage
channel to reduce stream velocity and a drainage pipe installed to direct water flow.
ISUBSURFACE EXPLORATIONS
Subsurface conditions at the sites were evaluated by examining the exposed bluff and 9 ft. cut on the north boundary
I with the neighboring property. The bluff was exposed for 18 ft. below building level, and the cut slope 9 more feet
above building level. The soils encountered were visually classified in accordance with ASTM D-2487. The log of
the soil profile is included in the appendix.
ISUBSURFACE CONDITIONS
In general, disturbed dense till was observed in the building portion of the site. A disturbed fill was encountered at
depths of between 2 and 3 feet below the existing ground surface in the area of an old water drainage channel. The
fill thickness ranged from a few inches to 3 feet in the southernmost portion of the site to approximately 0 feet in the
Ibuilding portion of the site.
No groundwater seepage was observed in the test pit excavation in the drainfield area of the site. Based on the nature
of the near surface soils, intermittent outwash and weathered sand over undisturbed gravely sand in the building area,
II _ seasonally perched groundwater conditions should be expected even during periods of extended dry weather. This
should not pose a significant problem if a drainage swale on the uphill site of the building area is installed.
SLOPE STABILITY
Slopes as steep as 45 percent and more were observed in all portions of the site. Since slopes of 45 percent or greater
O with 10 feet or more of vertical relief occur on portions of the site, Mason County requires that a"Geologic Hazards"
report be completed as per the Critical Areas Ordinance. Slopes of 1.5 to 30 percent and greater than 30 percent
within the site area are identified on Figure 2.
' In general, the undisturbed native soils in the steep slope portions of the site consist of gravely sand with variable
amounts of silt. These sandy soil materials are in a dense to very dense condition except where they have been
disturbed by weathering activity.
The near-surface recessional, weathered advance outwash is in a medium dense to dense condition except at the
I ground surface. The surficial soils are generally in a loose to medium-dense condition. These soils are generally
stable relative to deep-seated failure. No evidence of deep-seated landslide activity or significant erosion was
observed at the site at the time of our site visit.
Weathering, erosion, and the resulting sloughing and shallow land sliding are natural processes that can affect steep
slope areas. Instability of this nature is typically confined to the upper weathered or disturbed zone, which has been
Idisturbed and has a lower strength.
Some evidence of local surficial erosion, raveling and sloughing was observed in the site area at the time of our site
visits.
A
10011 Blomberg Street SW, Olympia, WA 98512
IPhone#: (206)754-4612 Fax#: (206)754-4848
("ffEOTECHNICAL
TESTING LABORATORY
Significant weathering typically occurs in the upper 2 to 3 feet and is the result of oxidation, root penetration, wet/dry
cycles, and freeze/thaw cycles. Erosion in steep slope areas such as this can be reduced through proper design and
construction of the storm water systems. Erosion control recommendations for the sloping areas are provided in the
Building Setback and Erosion Control sections of this report.
Proper planning, design and construction techniques will reduce the risk of surficial erosion or movement in these
areas.
CONCLUSIONS AND RECONEMNDATIONS
GENERAL
Based on the results of our site reconnaissance and subsurface exploration program, and our experience in the area, it
is our opinion that the site is suitable for the proposed home. The slopes located in the building portion of the site
area and the adjacent property are stable relative to deep-seated instability and will not be affected by the proposed
project/development. Proper erosion/sediment and drainage control measures will reduce or eliminate the potential
for erosion in this area, and improve slope stability.
In general, the sand and gravel soils observed at the site are suitable for use as structural fill material. Material with
less than 10 percent fines should be considered equivalent to gravel base material. The sandy soils that occur on the
site are moisture-sensitive and susceptible to disturbance when wet. Saturated soil conditions may be associated with
these soils during or following extended periods of rainfall. To reduce grading time and construction costs, we
recommend that earthwork be undertaken during favorable weather conditions.
Conventional construction equipment may be utilized for work at the site. Conventional spread footings may be
_ utilized at the site for support of the structure. We do recommend that roof and footing drains be installed for the
home. A vapor barrier is recommended for all slab-on-grades. Infiltration of the storm water is possible at the site.
Pertinent conclusions and geotechnical recommendations regarding the design and construction of the proposed
development are presented below.
_ LANDSLIDE—EROSION HAZARD AREAS
Classification
The Mason County Critical Areas Ordinance defines a landslide hazard area as 1)one containing slopes equal to or
greater than 30 percent with more than a 10-foot vertical relief, and 2)one containing soils described by the Soil
Conservation Service(SCS) Soil Survey as having a"severe" limitation for building site development due to slope.
The slopes.located in the area of the site are in excess of 30 percent and the vertical relief is in excess of 10 feet.
-7 Based on this, this site does meet the technical criteria of a landslide hazard.
The soils at the site are mapped as Harstine gravelly sandy loam in the building portions of the site. The Harstine
soils are described as having a moderate erosion hazard, based on the present slope inclination.
These soils do meet the technical criteria of an erosion hazard.
10011 Blomberg Street SW, Olympia, WA 98512
Phone#: (206) 754-461.2 Fax#: (206)754-4848
GEOTECHNICAL
TESTING LABORATORY
Slope Stability
Based on our field observations, explorations and our experience with the soil types encountered on the property, we
conclude that although portions of the slopes exceed 30 percent, they are generally stable relative to deep-seated
failure in their present configuration.
No changes in slope stability are expected as a result of the proposed development of the site. Development will
occur in the level portions of the site based on appropriate engineering and building setback recommendations.
Grading in the building portion of the site should be conducted in accordance with geotechnical recommendations
provided herein. Site drainage will be collected and directed to the site's stormwater system.
As previously discussed, weathering, erosion, and,the resulting surficial sloughing and land sliding are natural
processes that affect slope areas. Significant weathering typically occurs in the upper 2 to 3 feet and is the result of
oxidation, root penetration, wet/dry cycles and freeze/thaw cycles. These processes can be managed and the risk
reduced through proper construction of the residence, including the stormwater system. Erosion control
recommendations in the slope and buffer areas are provided in the"Building Setback" and"Erosion Control"
sections of this report.
Building Setback
A building setback area from landslide hazard areas is required unless evaluated and reduced by an engineering
geologist or a licensed professional engineer. Cleaning, grading and filling within the setback area may not be
allowed because slope stability or the erosion hazard will be adversely impacted.
Based on our geotechnical evaluation of the site and our experience in the area, we recommend a building setback of
30 feet from the shoreline slope. The building setback may be measured from the bottom of the footing to the face of
the steep slope, in accordance with UBC.
As previously discussed, weathering, erosion and the resulting surficial sloughing and shallow land sliding are natural
processes that affect slope areas. As noted, no evidence of surficial raveling or sloughing was observed in the sloping
portions of the site. To manage and reduce the potential for these natural processes, we recommend the following:
1. No drainage of concentrated surface water or significant sheet flow onto or near the slope area. Drainage
from the roof and driveway area should be collected and tight lined to a disposal area in the natural draw to
the south of the proposed home.
2. No filling within the buffer or setback zone unless retained by retaining walls or constructed as an engineered
fill.
3. No percolation of surface water within 10 feet of Building Setback.
SEISMIC—LIQUEFACTION HAZARD
According to the Seismic Zone Map of the United States contained in Figure 16-2 of the 1997 UBC (Uniform
Building Code), the project site is located within Seismic Risk Zone 3.
10011 Blomberg Street SW, Olympia, WA 98512
Phone#: (206)754-4612 Fax#: (206)754-4848
GE0TECHNICAL
TESTING LABORATORY
Based on the subsurface conditions observed at the site, we interpret the site conditions to correspond to a seismic
Soil Profile Type Se, for Very Dense Soil, as defined by Table 16-J(UBQ. This is based on the range of SPT
(Standard Penetration Test)blow counts and/or probing with a %-inch diameter steel probe rod. The shallow soil
conditions were assumed to be representative for the site conditions beyond the depths explored.
Based on our review of the subsurface conditions, we conclude that the site soils are not.susceptible to liquefaction.
The near-surface soils are generally in a dense condition and the static water table is located below the surface.
Shaking of the already dense soil is not apt to produce a denser configuration and subsequently excess pore water
pressures are not likely to be produced.
EROSION CONTROL
'I
I
It is our opinion that the potential erosion hazard of the site is not a limiting factor for the proposed development.
Removal of natural vegetation should be minimized and limited to the active construction.areas. 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 ground cover/protection in
exposed areas and silt fences. Graded areas should be shaped to avoid concentrations of runoff onto cut or fill
_ slopes, natural slopes or other erosion-sensitive areas. Temporary ground cover such as straw or clear plastic
sheeting should be used until permanent erosion protection is established. No earthwork is anticipated on the steep
portions of the site.
EARTHWORK
Site Preparation
I All areas to be excavated should be cleared of deleterious matter including any existing structures, foundations,
abandoned utility lines, debris and vegetation.
Based on our explorations, we estimate that stripping on the order of 4 to 6 inches will be necessary to remove the
• root zone and surficial soils containing organics. Areas with deeper, unsuitable organics should be expected in the
vicinity of depressions or heavy vegetation. Stripping depths of up to 1. foot may occur in these areas. These
I materials may be stockpiled and later used for erosion control and landscaping. Materials that cannot be used for
landscaping or erosion control should be removed from the project site.
Where placement of fill material is required, the exposed sub-grade areas should be proof-rolled to a firm and
unyielding surface prior to placement of any fill. We recommend that trees be removed in such a manner so that a
majority of the roots are removed unless located on a slope. Excavations for tree stump removal in the building area
should be backfilled with structural fill compacted to the density requirements described in the"Structural Fill"
section of this report.
We recommend that a member of our staff evaluate the exposed sub-grade conditions after removal of vegetation and
topsoil stripping is completed and prior to placement of structural fill (if needed).
1
10011 Blomberg Street SW, Olympia, WA 98512
Phone#: (206) 754-4612 Fax#: (206)754-4848
i
GEOTECHNICAL
TESTING LABORATORY
The exposed sub-grade soil should be proof-rolled and tested for compaction by nuclear densometer during dry
Iweather or probed with a %2-inch-diameter steel rod during wet weather conditions.
Any soft, loose or otherwise unsuitable areas delineated during proof-rolling or probing should be re-compacted, if
I practical, or over-excavated and replaced with structural fill, based on the recommendations of our site
representative.
Structural Fill
All fill material should be placed as structural fill. The structural fill should be placed in horizontal lifts of
I appropriate thickness to allow adequate and uniform compaction of each lift. Fill should be compacted to at least 90
percent of MDD (maximum dry density as determined in accordance with ASTM D-1557/698)to within 2 feet of
sub-grade and 95 percent MDD in the upper 2 feet.
IThe appropriate lift thickness will depend on the fill characteristics and compaction equipment used. We recommend
that the appropriate lift thickness be evaluated by our field representative during construction. We recommend that
Iour representative be present during site grading activities to observe the work and perform field density tests.
The suitability of material for use as structural fill will depend on the gradation and moisture content of the soil. As
the amount of fines(material passing No. 200 sieve) increases, soil becomes increasingly sensitive to small changes
in moisture content and adequate compaction becomes more difficult to achieve. During wet weather, we recommend
use of well-graded sand and gravel with less than 5 percent(by weight)passing the No. 200 sieve based on that
fraction passing the 3/-inch sieve. If prolonged dry weather prevails during the earthwork and foundation installation
Iphase of construction, a somewhat higher(up to 12 percent) fines content will be acceptable.
Material placed for structural fill should be free of debris, organic matter, trash and cobbles greater than 6 inches in
diameter. The moisture content of the fill material should be adjusted as necessary for proper compaction.
Suitability of On-Site Soils as Fill
IDuring dry weather construction, any non-organic on-site soil may be considered for use as structural fill, provided it
meets the criteria described above in the structural fill section and can be compacted as recommended. If the material
I is over optimum moisture content when excavated, it will be necessary to aerate or dry the soil prior to placement as
structural fill.
The workability of a material for use as structural fill will depend on the gradation and moisture content of the soil.
As the amount of fines increases, soil becomes more sensitive to small changes in moisture content and adequate
compaction becomes more difficult or impossible to achieve.
In general, the native soils (sand and gravel)encountered in the test pit explorations at the site with less than 10
percent fines (material passing the US No. 200 Sieve)are suitable for use as structural fill. This material is
comparable to WSDOT "gravel base". Material with less than 5 percent fines will be suitable as structural fill
during wet weather conditions.
10011 Blomberg Street SW, Olympia,OI m is, WA 98512
r Phone#: (206)754-4612 Fax#: (206)754-4848
GEOTECHNICAL
TESTING LABORATORY
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.
CUT AND FILL SLOPES
All job site safety issues and precautions are the responsibility of the contractor providing services and/or work. The
following cut/fill slope guidelines are provided for planning purposes.
Temporary cut'slopes will likely be necessary during grading operations. As a general guide,temporary slopes of 1.5
to 1 (horizontal to vertical)or flatter may be used for temporary cuts in the upper 3 to 4 feet of the glacially
—i consolidated soils that are weathered to a loose/medium dense condition. Temporary slopes of 1 to 1 or flatter may
be used in the un-weathered dense to very dense sands and gravels or till.
These guidelines assume that all surface loads are kept at a minimum distance of at least one half the depth of the cut
away from the top of the slope and that significant seepage is not present on the slope face. Flatter cut slopes will be
necessary where significant raveling or seepage occurs.
We recommend a maximum slope of 2 to 1 for permanent cut and fill slopes. Where 2 to 1 slopes are not feasible,
shoring of the slopes should be considered. Fill placed on slopes that are steeper than 4 to 1 should be"keyed" into
the undisturbed native soils by cutting a series of horizontal benches. The benches should be 1 %times the width
of the equipment used for grading and a maximum of 3 feet in height. Subsurface drainage may be required in
' seepage areas. Surface drainage should be directed away from all slope faces. Some minor raveling may occur with
time. All slopes should be seeded as soon as practical to facilitate the development of a protective vegetative cover or
otherwise protected.
FOUNDATION SUPPORT
All exterior footing elements should be embedded as least 18 inches below grade for frost protection. Where
_ foundation elements are located near slopes of 5 percent or more,the footings should be located a minimum of 2
times the footing width from the slope face(horizontally), and founded in medium dense or denser native soils or
properly prepared structural fill.
We recommend a minimum width of 2 feet for isolated footings and at least 16 inches for continuous wall footings.
Footings founded as described above can be designed using an allowable soil bearing capacity of 2,000 psf(pounds
per square foot)for combined dead and long-term live loads in areas of medium dense to dense soils.
The weight of the footing and any overlying backfill may be neglected. The allowable bearing value may be
increased by one-third, for transient loads, such as those induced by seismic events, or wind loads.
Lateral loads may be resisted by friction on the base of footings and floor slabs and as passive pressure on the sides
of footings. We recommend-that an allowable coefficient of friction of 0.40 be used to calculate friction between the
concrete and the underlying soil. Passive pressure may be determined using an allowable equivalent fluid density of
200 pcf(pounds per cubic foot). Factors of safety have been applied to these values.
10011 Blomberg Street SW, Olympia, WA 98512
Phone#: (206) 754-4612 Fax#: (206)754-4848
i
GEOTECHNICAL
TESTING LABORATORY
We estimate that settlements of footings designed and constructed as recommended will be less than 1 inch for the
I anticipated load conditions, with differential settlements between comparably loaded footings of/z inch or less. Most
of the settlements should occur essentially as loads are being applied. However, disturbance of the foundation sub-
grade during construction could result in larger settlements than predicted.
IFLOOR SLAB SUPPORT
I Slabs-on-grade(garage)should be supported on medium dense or dense native soils or on structural fill prepared as
described in the"Structural Fill"section of this report. We recommend that floor slabs be directly underlain by a
minimum 6-inch thickness of coarse sand and/or gravel containing less than 3 percent fines (by weight). The
drainage material should be placed in one lift and compacted to an unyielding condition.
A synthetic vapor barrier should be used for the control of moisture migration through the slab, in particular where
I adhesives are used to anchor carpet or tile to the slab. A thin layer of sand may be placed over the vapor barrier and
immediately below the slab to protect the liner during steel and/or concrete placement. The lack of a vapor barrier
could result in wet spots on the slab, particularly in storage areas.
IA sub-grade modulus of 400 kcf(kips per cubic foot)may be used for floor slab design. We estimate that settlement
of the floor slabs designed and constructed as recommended, will be'/z inch or less over a span of 50 feet.
Retaining Wall
Retaining walls may possibly be utilized in the sloping areas of the site. We understand that no structural fill will
I likely be placed behind these walls. Options for walls, other than conventional concrete retaining walls, include
reinforced earth systems such as small/large block walls, rolled-faced walls or one or two man rockery systems with
crushed rock backfill.
Typically, reinforced-earth block wall systems are more cost effective for long-term walls than the other options.
Specific design criteria for these options can be provided at your request.
PAVEMENT SUB GRADE
I We recommend that pavement sub-grades if used be prepared in accordance with the previously described site
preparation and structural fill recommendations. The upper 2 feet of roadway sub-grade should have a density of at
least 95 percent of the MDD (ASTM D-1577)
ISITE DRAINAGE
All ground surfaces,pavements and sidewalks should be sloped away from the residences and associated structures.
Surface water runoff should be controlled by a system of curbs, berms, drainage swales, and/or catch basins, and
conveyed to the site's retention system. We recommend that conventional roof and footing drains be installed for the
home and garage. Drains should be provided behind all retaining walls. Roof drain should not be connected to the
footing drain.
10011 Blomberg Street SW, Olympia, WA 98512
Phone#: (206)754-4612 Fax#: (206)754-4848
GEOTECHNICAL
TESTING LABORATORY
We recommend that the collected storm water runoff at the site be directed to the site's storm water system. Based
on the soils encountered in the building portion of the site, it is our opinion that it is feasible to tie the drainage system
for the roof and footing into the drainage pipe already installed in the drainage channel on the south side of the lot
where the quarry spall has been placed. This discharge is already running into the Puget Sound.
We do not expect any adverse affects on the discharge condition of the groundwater system. The site's stormwater
runoff will match the existing stormwater conditions because all the water on this site already flows downhill and into
Puget Sound.
LEMTATIONS
We have prepared this report for use by Mr. And Mrs. Dan McNeely and members of their design team, for use in
the design of a portion of this project. The data used in preparing this report, and this report, should be provided to
prospective contractors for their bidding or estimating purposes only. Our report, conclusions and interpretations are
based on data from others and our site reconnaissance, and should not be construed as a warranty of the subsurface
conditions.
Variations in subsurface conditions are possible between the explorations and may also occur with time. A
contingency for unanticipated conditions should be included in the budget and schedule. Sufficient monitoring,
testing and consultation should be provided by our firm during construction to confirm that the conditions
encountered are consistent with those indicated by the explorations, to provide recommendations for design changes
should the conditions revealed during the work differ from those anticipated,and to evaluate whether earthwork and
foundation installation activities comply with contract plans and specifications.
IWhen the design is finalized, we recommend that the design and specifications be reviewed by our firm to see that our
recommendations have been interpreted and implemented as intended.
The scope of our services does not include services related to environmental remediation and construction safety
precautions. 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.
If there are any changes in the loads, grades, locations, configurations or type of facilities to be constructed, the
conclusions and recommendations presented in this report may not be fully applicable. If such changes are made, we
should be given the opportunity to review our recommendations and provide written modifications or verifications, as
appropriate.
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Respectfully submitted,
Harold Parks,
Engineering Geologist
M01M A0 — 3
10011 Blomberg Street SW, Olympia, WA 98512
Phone#: (206) 754-4612 Fax#: (206)754-4848
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