HomeMy WebLinkAboutGEO2025-00007 BLD2025-00143 Replace Garage Add ADU - BLD Engineering / Geo-tech Reports - 2/5/2025 �-�oaUaS-oodo7
1A A., �LAN N I N G
MASON COUN Submittal Checklist
COMMUNITY SERVIC C E I VE@eOteCh n i ca I Report
\ Budding,Planning,Environmental Health,Community Health
FEB - 5 2025
Instructions: W. Alder Street
This checklist must be submitted with a Geotechnical Report and completed, signed, and stamped by the licensed
professional(s)who prepared the Geotechnical Report for review by Mason County pursuant to the Mason County
Resource Ordinance. If an item is found not applicable, the report should explain the basis for the conclusion.
Note: Unless specifically documented, this report does not provide compliance to the International Residential Code Sections
R403.1.7 for foundations on or adjacent to slopes, Section R403.1.8 for expansive soils or section 1808.7.1 of the International
Building Code Section for Foundations on or adjacent to slopes.
Applicant/Owner Julie & Doug Backous Parcel # 22406-51-00018
Site Address 371 N Webster Ln, Lilliwaup, WA 98555
(1) (a) A discussion of general geologic conditions in the vicinity of the proposed development,
Located on page(s) 2-3
(b) A discussion of specific soil types,
Located on page(s) 3 & 5
(c) A discussion of ground water conditions,
Located on page(s) 3-5
(d) A discussion of the upslope geomorphology,
Located on page(s) 2
(e) A discussion of the location of upland waterbodies and wetlands,
Located on page(s) 5
(f) A discussion of history of landslide activity in the vicinity, as available in the referenced maps and records.
Located on page(s) 7 & Figure 8
(2) A site plan which identifies the important development and geologic features.
Located on Map(s) 2
(3) Locations and logs of exploratory holes or probes.
Located on Map(s) Figure 5 & Appendix A
(4) The area of the proposed development, the boundaries of the hazard, and associated buffers and setbacks shall
be delineated (top, both sides, and toe) on a geologic map of the site.
Located on Map(s) Figure 2
(5) A minimum of one cross section at a scale which adequately depicts the subsurface profile, and which
incorporates the details of proposed grade changes.
Located on Map(s) Figure 11
(6) A description and results of slope stability analyses performed for both static and seismic loading conditions.
Analysis should examine worst case failures. The analysis should include the Simplified Bishop's Method of
Circles. The minimum static safety factor is 1.5, the minimum seismic safety factor is 1.1, and the quasi-static
analysis coefficients should be a value of 0.15.
Located on page(s) 9
(7) (a) Appropriate restrictions on placement of drainage features,
Rev. February 2018
Located on page(s 9-10
(b) Appropriate restrictions on placement of septic drain fields,
Located on page(s) Septic drain placement to remain as existing
(c) Appropriate restrictions on placement of compacted fills and footings,
Located on page(s) 11-13
(d) Recommended buffers from the landslide hazard areas shoreline bluffs and the tops of other slopes.
Located on page(s) Buffer to remain same as existing
(e) Recommended setbacks from the landslide hazard areas shoreline bluffs and the tops of other slopes.
Located on page(s) Setback to remain same as existing
(8) Recommendations for the preparation of a detailed clearing and grading plan which specifically identifies
vegetation to be removed, a schedule for vegetation removal and replanting, and the method of vegetation
removal.
Located on page(s) 10
(9) Recommendations for the preparation of a detailed temporary erosion control plan which identifies the specific
mitigating measures to be implemented during construction to protect the slope from erosion, landslides and
harmful construction methods.
Located on page(s) 10
(10) An analysis of both on-site and off-site impacts of the proposed development.
Located on page(s) 8-9
(11) Specifications of final development conditions such as, vegetative management, drainage, erosion control, and
buffer widths.
Located on page(s) 8-14
(12) Recommendations for the preparation of structural mitigation or details of other proposed mitigation.
Located on page(s) 9
(13) A site map drawn to scale showing the property boundaries, scale, north arrow, and the location and nature of
existing and proposed development on the site.
Located on Map(s) Figure 2
Chris Heathman, P.E. hereby certify under penalty of perjury that I am a civil engineer licensed in the
State of Washington with specialized knowledge of geotechnical/geological engineering or a geologist or engineering
geologist licensed in the State of Washington with special knowledge of the local conditions. I also certify that the
Geotechnical Report, dated 10/13/2024 and entitled
2486-MAS REVISED Geotechnical Report
Wd
547 �`` yPo meets all the requirements of the Mason County Resource Ordinance,
`
Geologically Hazardous Areas Section, is complete and true, that the
0 10/13/2024
'�'P 46365 � 44 assessment demonstrates conclusively that the risks posed by the
��ss/G�P2At.�= landslide hazard can be mitigated through the included geotechnical
design recommendations, and that all hazards are mitigated in such a
(Signature and Stamp) manner as to prevent harm to property and public health and safety.
Page 2 of 2
Disclaimer: Mason County does not certify the quality of the work done in this Geotechnical Report.
a
lull,
Mud Bay Geotechnical Services, LLC
1001 Cooper Point Road SW,STE 140 PMB 108 1 Olympia,WA 98502 1360.481.9784 1 CHeathman@MudBayGeotech.com
October 1311, 2024 Project No: 2486-MAS
Page 1
Subject: Critical Area Hazard — REVISED Geotechnical Report
371 N Webster Ln,
Lilliwaup, WA 98555
Parcel #22406-51-00018
Dear Julie and Doug Backous,
Per your request, Mud Bay Geotechnical Services, LLC is providing a geological assessment and
geotechnical report for the proposed site development project located at Mason County Tax
Parcel #22406-51-00018. The scope for this project was to perform a site reconnaissance and
review of the parcel to prepare a geotechnical report meeting the requirements of the Mason
County Critical Area Ordinance for development within a geologically hazardous area and its
associated buffers and setbacks. This is an updated report that supersedes all previous reports
for this project.
Per Mason County Code Section 8.52.140(A)(v) and (vi), slopes greater than fifteen percent with
a geologic contact with relatively permeable sediment overlying a relatively impermeable
sediment, and any area with a slope of forty percent or steeper, with a vertical relief of ten or more
feet is classified as a Geologically Hazardous Area. During our site investigation, it was concluded
that the parcel falls within three hundred feet of slopes greater than forty percent with a vertical
relief of ten or more feet when measured from the top of slope to the toe of slope. As such, the
above-mentioned subject parcel is considered within a Geologically Hazardous Area.
SITE LOCATION AND PROJECT DESCRIPTION
Parcel #22406-51-00018, consists of approximately 0.43 acres in Lilliwaup, Washington. The
parcel currently contains two intact structures: a detached two-car garage structure, and a
manufactured home/cabin. The garage is located near the center of the parcel, while the
2486-MAS: 371 N Webster Ln, Lilliwaup, WA 98555
manufactured home is situated further east, closer to the marine bluff steep slope. The lot is
accessed by a relatively flat gravel driveway extending east from N Webster Ln, terminating at
the garage building. The cabin building is situated about 60-feet east of the garage. On its east
side, the cabin includes a raised deck which is supported by 2-foot by 4-foot wooden beams.
These supports appear to be in good condition.
Elevations across the lot range from 30-feet at the site of the garage and cabin, to 0-feet at the
base of the sea bluffs on the east side. This vertical relief is accommodated by a steep slope
situated about 10-feet east of the cabin's eastern face. This steep slope is thoroughly vegetated
by native shrubs and young trees. The trees on the slope are all vertical and relatively straight-
trunked. A gravel trail with stairs on the property descends to the base of the marine bluffs,
providing access to the beach below. This trail appears to be in good condition, lacking any
significant landslide or erosion indicators. At the toe of the slope, an exposed bedrock bench
extends down to the water. This surface bedrock encompasses most of the beach land surface
at the east end of the parcel, though some loose beach sediments are also present. The
approximate location and boundaries of the parcel are shown in Figure 1, Site Map.
From discussions with you, the property owner, it is our understanding that the scope of work
includes the development of the parcel with a new residence and detached garage, within the
approximate footprints of the current existing structures. Per Mason County Code Section
8.52.170 Appendix B, "Replacement of a grandfathered structure, which does not conform to the
common line setbacks, is allowed provided the replacement is within the preexisting footprint".
Should you wish to relocate the structures, then it will be necessary to match the existing
structures' total footprint. It is important to note that any relocation or addition would need to result
in the proposed structures being further from the top of slope than the existing structures. This
comparison must be shown by a clear site plan delineating both existing and proposed footprints.
The scope of this report will be to assess the geologic hazards present on-site, provide
recommendations to facilitate the design and development of a new habitable structure, and meet
the requirements for a Mason County full geotechnical report. A site plan provided by Redding
Architects displaying the location of the proposed structures, and septic and stormwater systems
within the parcel has been attached to this report as Figure 2.
SITE GEOLOGY AND SOILS
As part of this project, available geologic data from the Washington State Department of Natural
Resources (WA DNR) available at the 1:100,000 scale was reviewed, and a site-specific geologic
2 1 P a g e
2486-MAS: 371 N Webster Ln, Lilliwaup,WA 98555
map was prepared. The project vicinity geologic map is attached as Figure 3, WA DNR Geologic
Map. Figure 3 indicates the project site is underlain by Pleistocene continental glacial till (Qgt)
The continental glacial till deposits (Qgt) are generally characterized as a highly compacted,
heterogeneous mixture of sediment ranging from boulders to clay-size particles. The conditions
observed on-site are generally consistent with the mapped geology for the region.
Along with the site geology, soil data was also reviewed and is represented in Figure 4, USDA
Soil Map. The soil within the proposed building area was mapped by the United States
Department of Agriculture Natural Resources Conservation Service (USDA NRCS), as Unit Hg—
Hoodsport stony sandy loam, 5 to 15 percent slopes.
The Hoodsport soil unit is described by the USDA NRCS as moderately well drained, gravelly to
stony medial sandy loam, sourced from basal till deposits. The estimated depth to water table
within the Hoodsport soils is approximately 19 to 36 inches. The mapped soil deposits are
consistent with the WA DNR Geologic Map and soil types observed on-site. It should be noted
that the slope percentages displayed on the map are estimates made by the USDA NRCS and
do not necessarily reflect true surface topography.
As a part of this report, the susceptibility of the on-site soils to sheet and rill erosion by water was
reviewed. The data suggests that the Hoodsport stony medial sandy loam is of low risk of sheet
and rill erosion. No indications of significant or ongoing erosion were noted on-site during our
exploration. In our opinion, the very dense vegetative cover across the property serves to mitigate
surficial soil erosion on-site.
SURFACE WATER AND DRAINAGE CONDITIONS
The glacial deposits mapped at the project site consist of highly variable drainage characteristics.
Some of the water falling on the surface of these deposits may pond in low lying areas or drain
directly as surface runoff to water bodies where it becomes channelized into creeks, rivers, and
lakes. The nature of these deposits allows for the surface water to create deeply incised channels
with steep sided slopes. Some of the surface water also infiltrates into the ground and exits down
gradient as seepage or through other surface water bodies. The slopes within and surrounding
the parcel are well vegetated. The upkeep of natural and planted vegetation is encouraged so
that the amount of surface runoff can be reduced to the greatest extent possible.
Localized seepage is common within lenses of coarser grained sand and gravel contained in the
native glacial deposits mapped at the site. Localized seepage typically occurs in areas where
coarser soils such as sands and gravels are trapped within finer-grained silts and clays.
3 �
2486-MAS: 371 N Webster Ln, Lilliwaup, WA 98555
During our investigation of the site, an unnamed stormwater/drainage pond was noted to be
present west of the subject parcel. This pond is downslope of the subject property at an elevation
of 10-feet above sea level. No upland waterbodies or wetlands were noted during our investigation
of the site nor our review of available remote imagery.
SUBSURFACE EXPLORATION
As part of the investigation, a site visit was performed on November 14th, 2023, to observe the
soil conditions on the parcel. Two(2) shallow hand-augured borings in conjunction with downhole
dynamic cone penetrometer testing were completed specifically for the subject development. The
approximate locations of these borings are shown in the attached Figure 5, Site Exploration Map.
Each boring was completed using a Humboldt Manufacturing model H-4414QC hand auger with
a 4- inch diameter bucket tube sampler. In situ testing was performed at selected depths using a
Humboldt Manufacturing model H-4202A dynamic cone penetrometer to estimate the density of
the soil. The dynamic cone penetrometer uses a 15-lbs steel mass falling from a height of 20-
inches onto an anvil to penetrate a 1.5-inch diameter 45-degree cone tip seated into the bottom
of the hole. Upon excavating to the test depth, to be sure the cone is completely embedded, the
cone point is seated 2-inches into the undisturbed bottom of the hole using the dynamic cone
penetrometer. The cone point is further driven 1 % inches using the ring weight hammer falling
20-inches. The blows for each interval are counted and recorded until one of the following occurs:
• A total of 50 blows occurs in less than 1 3/ inches of penetration in any increment.
• The rod is advanced the complete test increment for a total of 3 3/ inches (2-inch
embedment, and 1 3/ inch completed test increment).
The soil samples were classified visually in the field in general accordance with ASTM D2488,
The Standard Practice for Description and Identification of Soils(Visual-Manual Procedure). Once
transported back to the office, the samples were re-examined, and the field classifications were
modified accordingly. Summary logs of the borings are included in Appendix A. Note the soil
descriptions and interfaces shown on the logs are interpretive, and actual changes may be
gradual. Upon completion, the borings were backfilled to the original ground surface using
excavated material from the spoil piles.
4 1 P a g e
2486-MAS: 371 N Webster Ln, Lilliwaup, WA 98555
SUBSURFACE AND GROUNDWATER CONDITIONS
BH-1-23
The first boring, designated BH-1-23, was completed to a final depth of 48 inches below ground
surface elevation. BH-1-23 was performed near the firepit within the proposed cabin footprint. The
conditions encountered within BH-1-23 were as follows:
• 0 to 6 inches: Medium-dense, moist, dark grey, well-graded gravel with sand, (GW).
• 6 to 24 inches: Loose, moist, brown gravelly silt with sand (ML).
• 24 to 48 inches: Loose to very-dense, moist, tan gravelly silt with sand (ML).
Active groundwater seepage was not observed within BH-1-23.
BH-2-23
The second boring, designated BH-2-23, was completed to a final depth of 48 inches below
ground surface elevation. BH-2-23 was performed near the center of the parcel within the
proposed garage footprint. The conditions encountered within BH-2-23 were as follows:
• 0 to 6 inches: Topsoil, (TOPSOIL).
• 6 to 36 inches: Very-loose, moist, brown silt with gravel (ML).
• 36 to 48 inches: Very-dense, moist, grey silt (ML).
Active groundwater seepage was not observed within BH-2-23 at the time of excavation on
November 1411, 2023. The soil conditions found in BH-2-23 displayed consistency with those
encountered in BH-1-23.
The nearest mapped wetlands are positioned approximately 200 feet southwest of the subject
site's western property line. These wetlands cover an area of 1.66 acres and are characterized
as a freshwater pond. These nearest wetlands are situated at an elevation between roughly 10 to
15 feet above sea level, below the elevation of the existing single-family residence. No upland
waterbodies or wetlands were observed while on-site nor during our review of available resources.
Department of Ecology Well Logs
To supplement our subsurface explorations of the site, we reviewed regional well logs made
available by the Washington State Department of Ecology (WA DOE). Based on our review of
nearby well logs and our interpretation of the topography, we estimate that the depth to static
groundwater in the region. Based on the available well logs in the region and the lack of active
51Page
2486-MAS: 371 N Webster Ln, Lilliwaup, WA 98555
groundwater seepage within our subsurface explorations, we anticipate that the groundwater
table is below the limits of excavation associated with the proposed developments with the
possible exception of perched groundwater atop fine-grained or impermeable sedimentary units.
It should be noted that due to the site's proximity to Hood Canal as well as its position along a
peninsula extending into the water body, groundwater may be found at a shallower depth on-site
relative to the surrounding vicinity. Considering that groundwater seepage/springing was not
observed within boreholes drilled during geotechnical exploration, we do not anticipate that
groundwater will be encountered within the temporary excavation.
GEOLOGIC HAZARD ASSESSMENT
Liquefaction Hazard
The attached Figure 6, Liquefaction Hazard Map, displays liquefaction susceptibility data
available from the Washington State Department of Natural Resources (WA DNR). Soil
liquefaction is a phenomenon whereby saturated soil deposits temporarily lose strength and
behave as a viscous fluid in response to cyclic loading. This phenomenon is most significant in
loose, saturated sandy soils with lesser effects experienced in other soil types. Figure 5 indicates
the project vicinity has a Very Low liquefaction susceptibility. Based on our observation of very
dense, gravelly silts in the subsurface, it is our interpretation that the sediments on-site are of very
low liquefaction risk.
Tsunami Hazard
Due to the site's proximity to Hood Canal, the tsunami hazard for the region was explored. The
resulting tsunami hazard areas available from the Washington State Department of Natural
Resources (WA DNR) are shown in the attached Figure 7, Tsunami Hazard Map. Figure 7
indicates that the subject site and surrounding vicinity are within a mapped tsunami hazard area.
Protecting the home from tsunami impact would involve designing the structure for the forces of
the wave impact, and the anticipated scour upon the tsunami flood retreat. Tsunami forces can
be mitigated by installing deflector structures and/or raising the structure up above the anticipated
height of the tsunami on an open pier system with deep foundations that can accommodate the
forces allowing the wave to pass through. The effects of scour upon flood retreat could be
accommodated by using deep foundations or locating the shallow foundation supports below the
scour depth. Designing for these issues would likely make the development cost prohibitive and
is generally not the practice of development for other parcels in this area.
6 1 P a g e
2486-MAS: 371 N Webster Ln, Lilliwaup, WA 98555
As tsunami hazards are generally unavoidable within the local region, tsunami warning signals
and evacuation routes should be recognized by the residents of the proposed home structure.
The best way to protect life safety from a tsunami is to move to high ground — at least 50 feet
above sea level, if possible. If you don't have time to travel to high ground, but are in a multi-story
building, go to an upper level.
Steep Slope & Landslide Hazard
As part of the site investigation, we reviewed landslide hazard mapping and LiDAR imagery,
available from the Washington Department of Natural Resources (WA DNR). The current
landslide hazard mapping inventory available shows "Landslide Compilation" at the 1:24,000-
scale. This layer is composed of different WA DNR landslide layer datasets that represent various
landslide mapping techniques to remotely identify geomorphic features that typically represent
areas with the potential for landslide activity. The landslide data is included as Figure 8, WA DNR
Landslide Map. Figure 8 indicates that the nearest mapped landslide is approximately 0.75 miles
to the west of the parcel. Based on the dense soils and shallow bedrock present within the lot's
subsurface, and the significant distance from any mapped landslides, we believe the risk for deep-
seated landslide at the parcel to be very low.
In addition to WA DNR landslide hazard mapping, the geomorphology (shape of the land) was
analyzed during the site evaluation and compared to the Light Detection and Ranging images
(LiDAR) from the Washington State LiDAR portal. LiDAR is a remote sensing method where light
is pulsed down to the surface of the Earth and back to a sensor. Quantum Geographic Information
Systems software (QGIS) was used to create the LiDAR derived digital elevation hillshade map
and processed with overlying contours lines at two- (2) and ten- (10) foot intervals. This
methodology enables bare earth images of the surface to be analyzed for the presence of
important geologic landforms. The most recent available LiDAR images of this site are from 2019,
attached as Figure 9, QGIS LiDAR & Contour Map. Figure 9 shows that the topographical relief
across the parcel is predominantly accommodated by the marine bluff steep slope on its eastern
side. The western portion of the parcel, where the garage and cabin structures reside is flat. The
total elevation difference across the parcel is approximately 30ft, ranging from 30-feet at N
Webster Ln on the west side, to 0-feet at the eastern beach.
Using QGIS, slope percentage values were calculated by making use of elevation data from the
most recent LiDAR data available, olympics_south_opsw 2019 dtm_34, a digital terrain model
data set from 2019. The slope calculations are expressed as a percentage, where the difference
of two elevation points (rise) is divided by the distance between them (run) and then multiplied by
71Page
2486-MAS: 371 N Webster Ln, Lilliwaup,WA 98555
100. For reference, a slope percentage of 100% is equal to a 45' slope angle, where the rise is
equal to the run. The slope map for the area is shown in Figure 10, QGIS Slope & Contour Map.
Figure 10 indicates that the majority of the parcel's slopes range from 0-15%, and the marine
bluff's slopes being greater, ranging from 15-100%. The proposed development areas are within
area mapped with slopes ranging from 0 to 15 percent with small portions ranging from 15 to 40
percent.
Utilizing QGIS software, a single slope transect was drawn southeastward from the floor of the
ravine through the steep slopes and proposed development area to the southern property
boundary. The transect was designated Line A-A', drawn roughly orthogonal to the elevation
contour lines, and is shown at a 1.00 vertical exaggeration. The orientation of the slope transect
and resulting profile are shown in the attached Figure 11, Slope Transect & Profile. Figure 11
shows that the marine bluff slopes account for most of elevation difference across the subject
property. Transect A-A' spans a vertical elevation difference of approximately 30 feet over a
horizontal distance of roughly 280 feet.
During the site investigation, the parcel and surrounding area was assessed for signs indicating
potential slope movement. The slopes were visually inspected for indicators of active or recent
mass-wasting and erosion. Between the slope and proposed development area, the property was
noted to be vegetated with native shrubs and young conifer trees. No indications of significant
erosion or recent failure were noted within the bounds of the property. No indications of pooling
or poor drainage were observed across the proposed development area or near the top of slope.
GEOTECHNICAL RECOMMENDATIONS
Critical Area Geologic Setbacks
Based on site reconnaissance, subsurface exploration, and a review of the site geology and other
readily available information presented previously, in the opinion of Mud Bay Geotechnical
Services, LLC the potential for deep-seated landslide is low for the property.
From discussions with you, the property owner, it is our understanding that the scope of work
includes the development of the parcel with a new residence and detached garage, within the
approximate footprints of the current existing structures. Per Mason County Code Section
8.52.170 Appendix B, "Replacement of a grandfathered structure, which does not conform to the
common line setbacks, is allowed provided the replacement is within the preexisting footprint".
Should you wish to relocate the structures, then it will be necessary to match the existing
structures' total footprint. It is important to note that any relocation or addition would need to result
81Page
2486-MAS: 371 N Webster Ln, Lilliwaup, WA 98555
in the proposed structures being further from the top of slope than the existing structures. This
comparison must be shown by a clear site plan delineating both existing and proposed footprints.
In our opinion, the new home structure does not encroach closer to the slope than the setback of
the previous structure. As such, it is our interpretation that the proposed developments within
Parcel #22406-51-00018 will not serve to increase the risk of geologic hazard on-site nor within
the surrounding properties.
We performed an assessment of the slope stability for the site under static and seismic conditions
for the design seismic event at the site location. Based on the results, the proposed development
will not serve to increase on-site or off-site risk of landslide or erosion activity and will maintain a
slope stability factor of safety greater than 1.5 under static conditions and 1.1 under seismic
conditions.
Drainage Considerations
Any groundwater seepage exposed during construction of the structure should be removed from
the excavation area and/or directed away to an area where it can be discharged and stored until
it fully infiltrates into the ground.
The site should include a proper drainage design to control and properly discharge surface water.
The surface of the developed portion of the parcel should be graded to allow water to flow and
collect in a manner that does not increase the surface erosion. Stormwater drainage falling directly
onto impervious surfaces should be collected directly in catch basins, rain drains, and downspouts
and directed via drain lines to an appropriate discharge area with slopes less than 15 percent. All
stormwater drainage that does not discharge into an existing stormwater conveyance should
terminate in a T-shaped elbow underlain by a quarry spall apron with a minimum width of 2 feet
and a minimum length of 4 feet to dissipate the energy of the flowing water. The quarry spalls
should be underlain by a geotextile meeting the requirements of a Construction Geosynthetic for
Underground Drainage in Section 9-33 of the WSDOT Standard Specifications. Stormwater runoff
must be routed away from the top of slope; no stormwater should be discharged at the top of
slope to limit erosion.
Excessive water can affect slope stability. Care should be taken to control the excess of water
being introduced to the slope. All drain lines should be routed all the way down the slope to the
lowest extent possible and or away to areas with less than 15 percent slope, and/or tied into the
local stormwater systems. Discharging all stormwater to the lowest point possible away from
9 1 P a g e
2486-MAS: 371 N Webster Ln, Lilliwaup,WA 98555
structures is the preferred method for discharging stormwater and is one of the most pertinent
mechanisms in reducing slope failure and the erosive action affecting structures in the future.
The discharge outfall of stormwater pipes that do not connect directly to existing stormwater
conveyance facilities or stormwater storage facilities should include a T-shaped discharge outlet
underlain by a quarry spall apron with a minimum width of 2.5 feet and a minimum length of 4 feet
to dissipate the energy of the flowing water. The quarry spalls should be underlain by a geotextile
meeting the requirements of a Construction Geosynthetic for Underground Drainage in Section
9-33 of the WSDOT Standard Specifications.
Erosion Control
Onsite materials are erodible when exposed on steep slope areas. No excavated material should
be placed on the steep slopes. Soil stockpiles and exposed slope areas should be covered during
heavy rainfall. Silt fences should be used as an erosion control measure and to separate the
critical area boundary from the work area where disturbance is allowed. Jute, coir, or turf
reinforcement mat should be placed on the surface of all surfaces greater than 15 percent that
are disturbed during construction, pinned using 9-inch landscaping staples at a 16-inch spacing.
Plastic sheeting should not be used since this will only serve to increase the velocity and erosion
potential of stormwater on slopes. The erosion condition adjacent to structures should be
monitored periodically for any signs of surface erosion, degradation, and shallow failures. If
significant erosion or failures are observed, then those should be mitigated as soon as possible.
Vegetation should be maintained where it currently exists on existing slopes where disturbance
is not necessary as part of construction. Existing bare and disturbed soil areas should be planted
immediately following construction with grass and deep-rooted plants and native conifers to help
reduce erosion potential. Where felling of trees is necessary on slopes, stumps should be left
intact.
All graded slopes and exposed areas should be hydroseeded after grading is complete. If the
construction is not completed until the later part of the summer or fall and winter months, then the
slopes should be left covered until the springtime growing season.
Shallow Foundations
Shallow strip footings and shallow pier pads can be used to support the structure. Based on the
conditions observed in the explorations, we recommend locating the bottom of the new footings
on the native soil deposits at a minimum depth of approximately one foot below the existing
ground surface. Footings can be stepped into the existing topography to achieve the minimum
101Page
2486-MAS: 371 N Webster Ln, Lilliwaup, WA 98555
embedment criteria. However, the footings should be stepped at a maximum equivalent slope
angle of 15 percent across the profile of the structure in the downslope direction.
Based on the completed borings, the existing native soils are unsuitable to support the loads from
the structure without excessive settlement and should be removed to a depth of 3 feet below the
existing ground surface and replaced with more suitable material back up to the bottom of
foundation elevation. However, based on conversations with the proposed earthwork contractor
for the project, we understand that their experience in this development area is that very dense
soils are present at shallow depth which are difficult to excavate. Therefore, it may be possible to
eliminate the overexcavation requirement or limit it to only a portion of the foundation footprint if
it can be verified at the time of subgrade preparation that the soils are dense at shallow depth.
We recommend that a licensed geologist or professional engineer specializing in soils and
geotechnical engineering evaluate the subgrade at the time of construction so that the exact
extent of overexcavation and replacement can be determined, if it is necessary.
Prior to placement of concrete, the subgrade at the bottom of foundation depth should be cleared
and grubbed, and the exposed native subgrade soils should be compacted in place. The subgrade
should be inspected for any pockets of loose material. Loose material should be removed and
replaced with a minimum of 6-inches of Crushed Surfacing Base Course (CSBC) meeting the
requirements of Section 9-03.9(3) of the WSDOT Standard Specifications, or an equivalent
material. The CSBC should be placed in layers no greater than 6-inches and compacted to at
least 95 percent of the maximum dry density.
Footings bearing on a subgrade prepared as described above can be designed using a maximum
allowable bearing pressure of 1,500 psf. We recommend a minimum footing width of 16 inches
be used in the design. The maximum allowable bearing pressure may be increased by up to one-
third for short-term transient loading conditions such as wind and seismic loading. We anticipate
that total settlement will not exceed one inch, and differential settlement along an equivalent 50-
foot length of footing will not exceed half of the total settlement. The settlement is expected to be
elastic and will occur as the footings are loaded.
We recommend footing excavation, fill material placement and compaction, and subgrade
preparation be evaluated by Mud Bay Geotechnical Services, LLC prior to placement of concrete.
Foundation subgrade preparation should not be performed during periods of wet weather. We
recommend staging the foundation subgrade excavation, compaction of native subgrade soils,
and placement of CSBC to limit the time the foundation subgrade is exposed to weather.
11 1
2486-MAS: 371 N Webster Ln, Lilliwaup, WA 98555
Seismic Design
Based on the explorations performed and included in the geotechnical report for the project, we
recommend using the adjustment factors for Site Class D soils to determine the site class adjusted
seismic design accelerations at the site location.
Foundation Backfill
We recommend all backfill used as backfill for footings and stem walls be placed in horizontal
layers no more than 6 inches thick with each layer compacted to 95 percent of the maximum
density. The backfill material should be comprised of Select Borrow as described in Section 9-
03.14(2) of the WSDOT Standard Specifications, or an equivalent free-draining material.
Prior to backfilling, a perimeter footing drain system, consisting of a 4-inch diameter, perforated,
or slotted, rigid plastic pipe placed at the base of the structure excavations wherever existing
footings are exposed as part of the work. The drain should be embedded in a clean, free-draining
sand and gravel meeting the requirements of Section 9-03.12(4) of the WSDOT Standard
Specifications for Gravel Backfill for Drains. The drains should be sloped slightly to drain to an
appropriate discharge area.
Lateral Earth Pressures
Retaining walls should be designed to resist lateral earth pressures from the backfill that will be
behind the wall. For lateral load analysis, we recommend the geotechnical parameters in Table 1
be used for lateral design and analysis.
Table 1: Lateral Earth Pressure Parameters
Parameter Design Value
Retained Soil Unit Weight (y) 130 pcf
Wall Backfill Soil Friction Angle ((pf) 340
Active Earth Pressure (Ka) 0.28 (EFP 32.5 pcf)
Passive Earth Pressure (Kp) 3.53 (EFP 460 pcf)
The passive earth pressure coefficient and coefficient of sliding presented in Table 1 are ultimate
values and should be reduced by a factor of safety equal to 1.5 for final design. Active earth
pressures can be assumed for design, provided that the walls can yield laterally at least 0.001 H
(where H is the exposed wall height in feet).
121
2486-MAS: 371 N Webster Ln, Lilliwaup, WA 98555
Seismic loading represented as a rectangular shaped dynamic uniform lateral surcharge equal to
8H psf should be applied, with the resultant acting at a height of 0.5H, where H is the height of
the wall. This value, which was calculated using the Mononobe-Okabe method, is appropriate for
yielding walls designed in accordance with the International Building Code (IBC).
Slabs-On-Grade
All interior slabs-on-grade should be underlain by a capillary break at least 6 inches thick
consisting of free-draining, clean, coarse sand and fine gravel with a maximum particle size of/-
inch, no more than 50 percent passing the U.S. No. 4 sieve, and less than 5 percent passing the
U.S. No. 200 sieve.
Prior to placement of the capillary break layer, topsoil, mud, debris, and root masses should be
cleared and grubbed and the native subgrade soils should be compacted in-place to a dense and
relatively unyielding condition. The six-inch capillary break layer should be compacted to at least
95 percent of the maximum dry density of the material. We recommend considering placement of
a suitable vapor barrier to further retard moisture at the slab-on-grade.
Like footing construction, it will be helpful to stage the excavation and subgrade preparation of
slab-on-grade areas to limit the exposure to wet weather during the placement of the capillary
break layer. Once in place and compacted, the low-fines-content capillary break layer will reduce
the likelihood that the subgrade is disturbed.
We recommend using a vertical modulus (K,,) of 85 pounds per cubic inch (pci)for slab-on-grade
bearing on a subgrade prepared as described above. Note that K,, is appropriate for a 1-foot by
1-foot surface, and the initial subgrade modulus used for design (KS) will need to be adjusted
based on the width of the footing or slab considered using the following equation:
KS = K,,(B+1)2/(4B2)
where B = foundation or slab width in feet.
Utilities
Utilities may need to be temporarily or permanently relocated as part of the project. The utility
subgrade (base of trench excavation) should be relatively firm prior to placing bedding materials.
Subgrade that is observed to be soft, pumping, or containing abundant organics or refuse should
be sub-excavated to firm subgrade soil or a maximum depth of 2 feet. Sub-excavated areas
should be backfilled with structural fill. All new utilities that traverse through critical area geologic
hazard zones should be constructed at a depth between 18 and 24 inches below the existing
131
2486-MAS: 371 N Webster Ln, Lilliwaup, WA 98555
ground surface. The utility subgrade (base of trench excavation) should be compacted in place to
a relatively firm prior to placing bedding materials.
Material placed directly below, around, and above utility pipes should consist of Gravel Backfill
for Pipe Zone Bedding as described in Section 9-03.12(3)of the WSDOT Standard Specifications.
The pipe bedding materials should be placed and compacted to a relatively firm condition in
accordance with the manufacturer's specifications. Bedding and cover should be a minimum of
6-inches thick.
Temporary Excavations
Temporary excavations will be necessary to construct the project. It is our interpretation that the
groundwater table will be greater than the limits of excavation for the subject project except for
perched water-bearing strata. We anticipate that temporary excavation cuts above the
groundwater table will be stable at up to 4 feet in height at a vertical inclination, and any remaining
height, or any excavation limits below the groundwater table, will be stable at a maximum slope
angle of 1 H:1 V. The ground surface at the top of the temporary cuts should be periodically
monitored for vertical movement, cracks, and other signs of instability. If signs of instability are
observed, we should be contacted immediately so that we can assist and provide additional
geotechnical recommendations. Temporary excavations greater than 4 feet in height and steeper
than 1 H:1 V may require structural shoring to maintain stability. The design of temporary shoring
is beyond the scope of services for this report.
Site Grading and Earthwork Considerations
Permanent cuts and fills should be stable at slopes of 2H:1 V. Soils placed as fill beyond the limits
of wall backfill zones, over excavation and replacement, and other fill areas as described
previously should be considered Structural Fill. Structural Fill should consist of material meeting
the requirements of Select Borrow as described in Section 9-03.14(2) of the WSDOT Standard
Specifications.
Structural Fill material should be placed and compacted in lifts no greater than 6 inches with a
plate compactor or jumping jack compactor. Structural fill should be placed and compacted to a
minimum of 95 percent of the maximum dry density. All other fill material should be placed and
compacted as described previously. Surface fill placed in softscape, landscape, or common areas
that can accommodate some settlement should be compacted to a relatively firm and unyielding
condition.
141
2486-MAS: 371 N Webster Ln, Lilliwaup, WA 98555
Pin Pile Foundations
We understand that pin pile foundations will be used to support the new deck. The pin piles should
consist of galvanized steel, open-ended pipe piles. Based on the limited access at the site, small
equipment will be necessary to install the piles. The pin piles should be installed using a 90-pound
pneumatic hammer to a minimum depth of 6 feet below the existing ground, or to refusal,
whichever is deeper. Refusal is defined as an advancement rate less than or equal to 1 inch within
a 60 second period. Larger pneumatic hammers may be used at the contractor's discretion using
these same criteria for refusal. Pin piles installed with these minimum requirements should
develop allowable (downward) pile capacities equal to or exceeding 6 kips.
RECOMMENDED ADDITIONAL SERVICES
Before construction begins, we recommend a copy of the draft plans and specifications prepared
for the project be made available for review so that we can ensure that the geotechnical
recommendations in this report are included in the Contract. Mud Bay Geotechnical Services,
LLC is also available to provide geotechnical engineering and construction monitoring services
throughout the remainder of the design and construction of the project. The integrity of the
geotechnical elements of a project depends on proper site preparation and construction
procedures. In addition, engineering decisions may need to be made in the field if conditions are
encountered that differ from those described in this report. During the construction phase of the
project, we recommend that Mud Bay Geotechnical Services, LLC be retained to review
construction proposals and submittals, observe foundation subgrade conditions, observe pin pile
foundation installation, and provide recommendations for any other geotechnical considerations
that may arise during construction.
INTENDED USE AND LIMITATIONS
This report has been prepared to assist the client and their consultants in the engineering design
and construction of the subject project. It should not be used, in part or in whole for other purposes
without contacting Mud Bay Geotechnical Services, LLC for a review of the applicability of such
reuse. This report should be made available to prospective contractors for their information only
and not as a warranty of ground conditions.
The conclusions and recommendations contained in this report are based on Mud Bay
Geotechnical Services, LLC understanding of the project at the time that the report was written
and on-site conditions that existed at time of the field exploration. If significant changes to the
nature, configuration, or scope of the project occur during the design process, we should be
151 = .
2486-MAS: 371 N Webster Ln, Lilliwaup, WA 98555
consulted to determine the impact of such changes on the recommendations and conclusions
presented in this report.
Site exploration and testing describes subsurface conditions only at the sites of subsurface
exploration and at the intervals where samples are collected. These data are interpreted by Mud
Bay Geotechnical Services, LLC rendering an opinion regarding the general subsurface
conditions. Actual subsurface conditions can be discovered only during earthwork and
construction operations. The distribution, continuity, thickness, and characteristics of identified
(and unidentified) subsurface materials may vary considerably from that indicated by the
subsurface data. While nothing can be done to prevent such variability, Mud Bay Geotechnical
Services, LLC is prepared to work with the project team to reduce the impacts of variability on
project design, construction, and performance.
We appreciate the opportunity to serve your geotechnical needs on this project and look forward
to working with you in the future. Please contact us at your earliest convenience if you have any
questions or would like to discuss any of the contents of this report.
Sincerely,
Chris Heathman, P.E.
Mud Bay Geotechnical Services, LLC
t 3.0Mlyh
10/13/2024
0
161
Google Earth
71 rY.
MBGS
r
i
Legend
Q Approximate Site Location
1 , Approximate Parcel Boundary
"Parcel boundaries derived from Mason County
iMap
Mud Bay Geotechnical Services, llC
• �'.�"'�..�s ' .,"� Job#:2486-MAS Date:Jan. 2024
;, ." Figure 1: Site Map
a y � 371 N Webster Ln
'k oft
- - Lilliwaup, WA 98555
' Geotechnical Report
A
PROJECT OWNER
PROJECT ADOME66
TAX PARCEL MU"WER!
ZONE
REDDING
ARCHITECTS
eotechnical Services, LLC
I&AMM
Mud Bay G
SITE PLAN
Job#:2486-MAS Date:Jan., 2024
NOM Figure 2: Job Details Schematic
371 N Webster Ln
Lilliwaup, WA 98555
Geotechnical Report
Sources:Esri,USGS I WA State Parks GIS,Esri,HERE,Garmin,FAO,NOAA,USGS,Bureau of Land Management,EPA,NPS I Washington Geological
Survey,2019,Surface geology,1:24,000—GIS data,November 2019:Washington Geological Survey Digital Data Series DS-10,version 3.1.
Legend
/ Approximate Parcel Boundary
Geologic Units 100k
❑ Quaternary alluvium
❑ Pleistocene continental glacial till
'C}b Pleistocene continental glacial
❑ drift
Quaternary bog, marsh, swamp or
❑ lake deposits
❑ Pleistocene glacial and
non-glacial deposits
Mud Bay Geotechnical Services, LLC
Job#:2486-MAS I Date:Jan. 2024
' Figure 3: WA DNR Geologic Map
371 N Webster Ln
N Lilliwaup, WA 98555
Geotechnical Report
Sal Map--Ja fets i County Area.Wasfwgtwi Mason CorrHy.Wasnrgtan and Olympic Naba"Forest Area Wasrw Vlon(Parts of Cueam.Grays Harbor USDA Natural Resources
Conservation Service
Legend
Approximate Parcel Boundary
Map Unit Symbol Map Unit Name
HoC Hoodsport very gravelly sandy
loam,0 to 15 percent slopes
HoD Hoodsport very gravelly sandy
loam.15 to 30 percent
slopes
y 1r
v sa-w
Mud Bay Geotechnical Services, LLC
�,Sry.,ae+oyp./aau Ar��e,tt.as,sfrR Job#:2486-MAS Date:Jan., 2024
Figure 4: USDA Soil Map
YChm 371 N Webster Ln
{p Natural Resources Websrw&.vey Lilliwaup, WA 98555
am Conservenonservlu NaearalCooperavve Soil Survey Geotechnical Report
• • • - IF
Legend
�, _ w �,.��.,;, Approximate Parcel Boundary
MB
.,�
�'=+ ' "•' ��=� � ® Approximate Boring Location
-
t r w.
ram.
Mud Bay Geotechnical Services, llC
Job#:2486-MAS Date:Jan. 2024
Figure 5: Site Exploration Map
371 N Webster Ln
00 ft
Lilliwaup, WA 98555
Geotechnical Report
Sources:Esri,USGS i WA State Parks GIS,Esri,HERE,Garmin,FAO,NOAA,USGS,Bureau of Land Management,EPA,NPS I Palmer,Stephen P.,
Magsino.Sammantha L.,Bilderback.Eric L..Poelstra,James L.,Folger,Derek S.,Niggemann,Rebecca A.,2007.Liquefaction susceptibility and site >€ r
class maps of Washington State.by county Washington Division of Geology and Earth Resources Open File Report 2004-20,[78 plates,45 p.text]. a
w„
"VON Legend
Approximate Parcel Boundary
Liquefaction Susceptibility
�itia7o
High
Moderate to High
Moderate
Low to Moderate
Q "Coo Low
E
Very Low to Low
Very Low
® Bedrock
4
Peat
AZ Mud Bay Geotechnical Services, LLC
Job#:2486-MAS I Date:Jan. 2024
' Figure 6: Liquefaction Hazard Map
371 N Webster Ln
N I Lilliwaup, WA 98555
------- Geotechnical Report
Sources:Esri,USGS I WA State Parks GIS,Esri,HERE Garmin,FAO,NOAA,USGS,Bureau of Land Management,EPA,NPS I Washington
Geological Survey.2022,Tsunami hazard--GIS data Washington Geological SON* Digital Data Series 22,version 1.5,July 2022. d
s
vLegend
Approximate Parcel Boundary
Tsunami
Mapped Hazard Area
r
w•�
Y4` rw i+; • w
in
�+
Mud Bay Geotechnical Services, LLC
Job#:2486-MAS I Date:Jan. 2024
' 2oom Figure 7: Tsunamis Hazard Map
371 N Webster Ln
N 600N Lilliwaup, WA 98555
Geotechnical Report
Sources:Esri,USGS I WA State.Parks GIS,Esri,HERE,Garmin,FAO NOAA,USGS,Bureau of Land Management EPA NPS I Washington
Geological Survey,2022,Washington State Landslide Inventory Database-GIS data,July 2022 Washington Geological Survey Digital Data Series 29, z
version Lo
r
Legend
Approximate Parcel Boundary
�. Landslides
Landslide Compilation
�"00 VIA
,.;
Mud Bay Geotechnicai Services, LLC
Job#:2486-MAS Date:Jan., 2024
f i," Figure 8: WA DNR Landslide Map
Us Kn'1' e � 371 N Webster Ln
FN' � Lilliwaup, WA 98555
4 Geotechnical Report
Legend
/ Approximate Parcel Boundary
/ 10'Contour Line
r-
° 2' Contour Line
o� ,
.3-i
,, Wy
e1.
R"
{
Mud Bay Geotechnical Services, PLC
*" Job#:2486-MAS Date:Jan. 2024
Figure 9: QGIS UDAR& Contour Map
0 25 50 tt ' 371 N Webster Ln
N Lilliwaup, WA 98555
Geotechnical Report
Legend
Approximate Parcel Boundary
/ 10' Contour Line
f 2' Contour Line
f f
Slope Percentage
f •—' 0-15%
_ � r
■ 15-40%
■
s 40-60%
t J �' ■ 60-100%
r
- Mud Bay Geotechnical Services, LLC
Job#:2486-MAS Date:Jan., 2024
__— Figure 10: QGIS Slope & Contour Map
0 50 100 ft ' 371 N Webster Ln
N Lilliwaup, WA 98555
Geotechnical Report
Legend
_~
Approximate Parcel Boundary
a
/ 10' Contour Line
A
!I
2' Contour Line
g � z
Transect LineA-A'
Slope Percentage
0-15%
NO a ❑ 15-40%
A'
40-60%
60-100%
>100%(45'+)
Mud Bay Geotechnical Services, LLC
A' Job#:2486-MAS I Date:Jan. 2024
Figure 11: Slope Transect & Profile
2U 371 N Webster Ln
Lilliwaup, WA 98555
Geotechnical Report
APPENDIX A - FINAL BORING LOGS
® Project: Client: Bore No. 1 of
� Critical Area Hazard Repo Doug&Julie Backous BH-1-23
Project Number: Contractor: Equipment:
Mud Bay Geotechnical Sevkes LLC 2486-MAS n/a Humboldt H-4414QC Auger
Address: Started: Bit Type: Diameter:
371 N Webster Ln 11/14/2023 Bucket Tube Auger 4 inches
Lilliwaup WA, 98555 2 Completed: Hammer Type: Fluid:
Parcel#22406-51-00018 0 11/14/2023 Humboldt H-4202A n/a
Logged By: Backfilled: Hammer Weight: Hammer Drop:
Calie Rose 11/14/2023 15 Ibs 20 inches
Helper: Groundwater Depth: Elevation: Total Depth of Boring:
Ba lee Fontana Not Encountered Existing Surface 48 inches
GPS Method: GPS Coordinates: GPS Elevation:
n/a n/a n/a
e Lithology U .. w
a a m
FE M 0 Soil Group Name:modifier,color,moisture,density/consistency,grain size,other T d F—
O Z O r_o descriptors
L U N y C
Vl L CL a) «d
C
O O O @ Rock Description:modifier,color,hardness/degree of concentration,bedding and M O O
rn COjoint characteristics,solutions,void conditions V Q
tn
0-6":(SW)-well graded sand
12" 6-48": (ML)
6-24": moist,brown,gravelly silt with sand(ML).
24" ® S-1 5 S-1: Loose,moist,brown silt with gravel(ML).
36"
48" ® S-2 REF S-2:Very dense, moist,tan gravelly silt with sand(ML).
Mottling present
60" Refusal criteria met at 1"penetration
72"
84"
96"
108"
120"
13 2"
144"
Test Pit and Boring Log Symbols Soil Density Modifiers
❑ Standard Penetration Slit Spoon Sampler(SPT) Gravel, Sand, Non-Plastic Silt Elastic Silts and Clays
8 California Sampler Blows/1 3/4" Density Blows/1 3/4" Consistency
® Shelby Tube 0-4 Very Loose 0-1 Very Soft
® CPP Sampler 5-10 Loose 2-4 Soft
1 Stabilized Ground water 11-24 Medium Dense 5-8 Medium Stiff
7 Groundwater At time of Drilling 25-50 Dense 9-15 Stiff
® Bulk/Bag Sample REF Very Dense 16-30 Very Stiff
31-60 Hard
>60 Very Hard
® Project: Client: Bore No.2 of 2:
� Critical Area Hazard Repo Doug&Julie Backous BH-2-23
Project Number: Contractor: Equipment:
Mud Bay Geote3trtltal Services,LLC 2486-MAS n/a Humboldt H-4414QC Auger
Address: Started: Bit Type: Diameter:
371 N Webster Ln 11/14/2023 Bucket Tube Auger 4 inches
Lilliwaup WA,98555 2 Completed: Hammer Type: Fluid:
Parcel#22406-51-00018 0 11/14/2023 Humboldt H-4202A n/a
Logged By: Backfilled: Hammer Weight: Hammer Drop:
Calie Rose 11/14/2023 15 Ibs 20 inches
Helper: Groundwater Depth: Elevation: Total Depth of Boring:
Ba lee Fontana Not Encountered Existing Surface 48 inches
GPS Method: GPS Coordinates: GPS Elevation:
n/a n/a n/a
m .. Lithology U N
n a
c5,
7 M 0 Soil Group Name:modifier,color,moisture,density/consistency,grain size,other
O Z O _U descriptors 7 M
t UN N C
N L G7
C
a) a O O Rock Description:modifier,color,hardness/degree of concentration,bedding and O 'C
N ra m 9 joint characteristics,solutions,void conditions U
N Q
0-6": (TOPSOIL)
12" 6-48".(ML)
6-36": moist,brown silt with gravel(ML).
24" ® S-1 4 S-1:Very loose, moist, brown silt with gravel(ML).
36"
36-48": moist,grey silt(ML).
48" ® S-2 REF S-2:Very dense, moist,grey silt.
Minor sand and gravel, mottling present
60"
72"
84"
96"
108"
120"
132"
144"
Test Pit and Boring Log Symbols Soil Density Modifiers
Q Standard Penetration Slit Spoon Sampler(SPT) Gravel,Sand, Non-Plastic Silt Elastic Silts and Clays
8 California Sampler Blows/1 3/4" Density Blows/1 3/4" Consistency
® Shelby Tube 0-4 Very Loose 0-1 Very Soft
® CPP Sampler 5-10 Loose 2-4 Soft
1 Stabllized Ground water 11-24 Medium Dense 5-8 Medium Stiff
Groundwater At time of Drilling 25-50 Dense 9-15 stiff
® Bulk/Bag Sample REF Very Dense 16-30 Very Stiff
31-60 Hard
>60 1 Very Hard