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1101 South Fawcett Avenue, Suite 200
Tacoma, Washington 98402
253.383.4940
February 26, 2021
Miles Sand & Gravel Company
400 Valley Avenue NE
Puyallup, Washington 98372
Attention: Ryan Ransavage
Subject: Geologic Summary Report
Shine Facility – Wahl Extraction Area MRL Overlay Expansion
Jefferson County, Washington
File No. 1355-035-06
We understand that Miles Sand & Gravel Company (Miles) is in the process of applying for a Mineral
Resource Lands Overlay District (MRL) expansion adjacent to their existing Wahl Extraction Area (WEA),
which is currently an operational construction aggregate extraction and processing facility. The purpose of
this report is to provide information required by Jefferson County Code (JCC) 18.20.240, Mineral extraction,
mining, quarrying and reclamation, for the designation of Mineral Resource Lands. In accordance with
JCC 18.20.240, this report includes the following information: (1) types of materials present on the site,
(2) quantity and quality of each material, (3) lateral extent of deposit(s), (4) depth of deposits, (5) depth of
overburden and (6) method of extraction.
PROPOSED MINERAL RESOURCE LANDS EXPANSION AREA
The proposed MRL expansion area comprises glaciated terrain south of State Route 104 and west of Hood
Canal. The proposed expansion area totals 200 acres adjacent and contiguous with existing MRL
designated areas (Figure 1). There are four sub-areas that are proposed to be added to the MRL overlay:
Areas A, B, C and D (Figure 2). This area is currently zoned and used for Commercial Forestry (CF-80) and
is part of the approximately 16,000-acre Thorndyke Tree Farm. The proposed area is owned and operated
by Rayonier Inc.
GEOLOGIC SETTING
Geologic conditions in the vicinity of the site are primarily the result of at least four regional continental
glaciations that advanced into Jefferson County during the Pleistocene (between approximately 12,000
and 2.6 million years ago) (Booth et al. 2004). During each glaciation, a complex assortment of till, outwash,
ice-contact stratified drift and glaciolacustrine sediments were deposited (Grimstad and Carson 1981).
The regional glaciations were separated by nonglacial or interglacial periods. The dominant sediments
representing the interglaciations are fine grained fluvial, lacustrine, marine sediments and peat.
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File No. 1355-035-06
During these glacial and interglacial periods, the bedrock of Western Washington and Western British
Columbia were eroded. Sediment was then deposited in glacial fluvial systems throughout the Puget
Lowland in advance of the glacial front and during glacial retreat. These sand and gravel deposits are the
main source of construction aggregates in Western Washington.
The proposed MRL area is located along the Thorndyke Creek valley. The valley is oversized in relation to
the current Thorndyke fluvial system, indicating that during the most recent glacial retreat, a much larger
fluvial system occupied the valley. Additionally, the location of this area between the Puget Sound and
Salish Sea, paired with the surface structure, indicate the site was a main drainage for glacial Lake Bretz
(Contreras et al. 2013). The geologic conditions described above indicate the MRL expansion area is likely
underlain by marketable sand and gravel reserves.
MATERIAL DESCRIPTION
Geologic maps of the project area indicate near surface soils generally consist of glacial sediments which
can be broken into three main material types: (1) Vashon recessional outwash / Vashon ice-contact
deposits (Qgo, Qgog, Qgic), (2) Vashon glacial till (Qgt) and (3) Olympia nonglacial deposits (Qco) (Contreras
et al. 2013, 2014).
Subsurface conditions in the MRL expansion area were evaluated by advancing three borings (SWE-1B,
SWE-4B and SWE-5B) at the locations show on Figure 2. The borings were advanced between February 15
and 25, 2021 by Holt Services using sonic drilling techniques and observed by Miles geologists. Subsurface
soils encountered in the explorations are generally consistent with the geologic maps. Logs of the borings
completed by Miles and reviewed by GeoEngineers are included in Attachment 1.
Vashon Recessional Outwash Deposits (Ogo, Qgog, Qgic)
Vashon recessional outwash deposits generally consist of loose, moderately to well sorted sand and gravel
with varying amounts of cobbles and silt. Vashon recessional outwash was deposited during and just after
the last retreat of glacial ice from Western Washington by meltwater channels. Deposits of recessional
outwash are typically 10 to 100 feet thick (Contreras et al. 2013).
Vashon ice-contact deposits generally consist of a mixture of loose to dense cobbly pebble gravel and
subglacial melt-out till (i.e.diamicton) and can be massive or well stratified. Vashon ice-contact deposits
were deposited from within or from the surface of the retreating ice or by meltwater running on, within or
adjacent to stagnant ice (Grimstad and Carson1981). It is difficult to distinguish between Vashon
recessional outwash and ice-contact deposits(Contreras et al. 2014).
Well graded sand and gravel with varying amounts of cobbles, boulders and silt, interpreted to be Vashon
recessional outwash deposits, were observed in borings SWE-1B and SWE-5B completed in Area D to
depths of approximately 71 feet and 51 feet, respectively (Attachment 1).
Vashon Glacial Till (Qgt)
Vashon glacial till deposits (also referred to as Vashon glacial drift – Qvd) generally consist of a complex
mixture of compacted, unsorted, unstratified clay, silt, sand and gravel (i.e., diamicton). Glacial till was
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File No. 1355-035-06
deposited at the base of, and subsequently overridden by, the advancing glacier and therefore, has been
compacted to a dense condition (Contreras et al. 2013).
Silty, well graded sand and gravel with cobbles, interpreted to be glacial drift, was observed in boring
SWE-4B from 2½ feet to approximately 25 feet below ground surface (bgs). Between depths of 25 and 49
feet, the glacial drift transitioned to an economically viable sand and gravel deposit with significantly less
silt (Attachment 1).
Olympia Nonglacial Deposits (Qco)
Olympia nonglacial deposits generally consist of loose to moderately compact, well sorted, massive to well
bedded and stratified sand and silt. Olympia nonglacial deposits represent distal Olympic and Cascade
alpine outwash deposited in a floodplain or lacustrine environment when the Puget Lowland was ice free.
Unit Qco is as much as 200 feet thick and is distributed throughout eastern Jefferson County (Contreras et
al. 2013).
In many areas around Puget Sound, Vashon glacial till is underlain by Vashon advance outwash (Qva), which
is similar in nature to the Olympia nonglacial deposits of eastern Jefferson County. According to Contreras,
et al. (2014) without age data, the Vashon advance outwash and the older nonglacial deposits appear so
similar that they cannot be separated.
A thick sequence of massive, well graded sand and well graded gravel with trace silt, interpreted to be
Vashon advance outwash and/or Olympia nonglacial deposits, was observed beneath the Vashon
recessional outwash in borings SWE-1B and SWE-5B, and beneath the Vashon glacial till/glacial drift in
boring SWE-4B, to the completion depths of the borings (Attachment 1).
SITE CHARACTERISTICS
There are four areas (A, B, C and D) that are proposed to be added to the MRL overlay and the existing WEA
are delineated on Figure 2. Areas A through C and the WEA are mapped as Vashon recessional outwash
gravel (Qgog), which is the material that Miles has been mining since 2013. Based on the glacial fluvial
structures observed in the site Lidar imagery (Figure 2), Areas A through C match the same glacial fluvial
structures of the WEA and appear to be a continuation of the same deposit. Based on borings completed
for the original WEA Conditional Use Permit, the aggregate deposit at the WEA site is approximately 40 to
65 feet thick. As such, Areas A through C contain high-quality aggregate deposits and should be included
in the Jefferson County MRL designation.
Area D is located southwest of the WEA and south of Thorndyke Creek (Figure 2). Area D is also mapped as
Vashon recessional outwash gravel (Qgog). Area D was drilled to assess the extent and thickness of
aggregate. The material identified in borings SWE-1B and SWE-5B consists of sand and gravel deposits
interpreted to be Vashon recessional outwash, Vashon advance outwash and/or Olympia nonglacial
deposits, occurring between approximately 2 and 145 feet bgs (Attachment 1). The material identified in
boring SWE-4B consists of Vashon glacial till/drift to a depth of 25 feet, underlain by sand and gravel
deposits interpreted to be Vashon advance outwash and/or Olympia nonglacial deposits to a depth of
146 feet. As such, Area D contains high-quality aggregate deposits and should be included in the Jefferson
County MRL designation.
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File No. 1355-035-06
The material properties and quantities are summarized in Table 1, based on the available topographic
information, current mine conditions and subsurface data obtained for the MRL overlay expansion project.
The materials are of high quality and will meet Washington State Department of Transportation (WSDOT)
standards once processed.
TABLE 1. MATERIAL PROPERTIES AND QUANTITIES FOR AREAS A THROUGH D
Proposed
Expansion Area Quality
Area
(Acres)
Maximum Depth
of Deposit
(feet)
Depth of
Overburden
(feet)
Quantity
(tons)
Area A High 22 45 3 1,200,000
Area B High 14 60 3 1,100,000
Area C High 11 40 3 500,000
Area D High 152 146 2 to 25 12,000,000
METHOD OF EXTRACTION
The proposed extraction methods include standard methods of sand and gravel extraction, including earth
moving equipment such as bulldozers, loaders, excavators, haul trucks and conveyors. Once the material
is removed from the ground, it is transported to be processed. The processing consists of sizing and/or
washing the material. Material over approximately 1 inch in size is crushed and processed into material for
road or foundation base and asphalt production. Blasting is not proposed for this project. In-water mining
is not proposed for this project.
CONCLUSIONS
Based on the information reviewed, proposed expansion Areas A through D are underlain by high-quality
aggregate deposits of long-term commercial significance and should be included in the Jefferson County
MRL designation.
LIMITATIONS
We have prepared this report for Miles Sand & Gravel Company for the Wahl Extraction Area MRL overlay
expansion project located in Jefferson County, Washington. Miles Sand & Gravel Company may distribute
copies of this report to their authorized agents and regulatory agencies as may be required for the project.
Within the limitations of scope, schedule and budget, our services have been executed in accordance with
generally accepted practices in the field of engineering geology in this area at the time this report was
prepared. The conclusions, recommendations and opinions presented in this report are based on our
professional knowledge, judgment and experience. No warranty or other conditions, express or implied,
should be understood.
Any electronic form, facsimile or hard copy of the original document (email, text, table and/or figure), if
provided, and any attachments should be considered a copy of the original document. The original
document is stored by GeoEngineers, Inc. and will serve as the official document of record.
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File No. 1355-035-06
REFERENCES
Booth, D.B., Troost, K.G., Clague, J.J., and Waitt, R.B. 2004. The Cordilleran ice sheet, in Gillespie, A.R.,
Porter, S.C., and Atwater, B.F., editors, The Quaternary Research, Elsevier Press, p. 17-43.
Contreras, T.A.; Stone, K.A.; Paulín, G.L. 2013. Geologic map of the Lofall 7.5-minute quadrangle, Jefferson
and Kitsap Counties, Washington: Washington Division of Geology and Earth Resources Map Series
2013-03, 1 sheet, scale 1:24,000, 19 p. text.
Contreras, T. A.; Patton, A. I.; Paulín, G.L., Hubert, I.J., Cakir, R., Carson, R.J. 2014. Geologic map of the
Quilcene 7.5-minute quadrangle, Jefferson County, Washington: Washington Division of Geology
and Earth Resources Map Series 2014-03, 1 sheet, scale 1:24,000, 27 p. text.
Grimstad, P., Carson, R.J. 1981. Geology and ground-water resources of eastern Jefferson County,
Washington: Washington Department of Ecology Water Supply Bulletin No. 54, 125 p., 3 plates.
Sincerely,
GeoEngineers, Inc.
Bridget A. August, LG, LHG Mark P. Molinari, LG, LHG
Senior Hydrogeologist Principal
BAA:MPM:mce
Disclaimer: Any electronic form, facsimile or hard copy of the original document (email, text, table and/or figure), if provided, and any attachments are only a copy
of the original document. The original document is stored by GeoEngineers, Inc. and will serve as the official document of record.
Attachments:
Figure 1. Area Map Showing Lateral Extent of Proposed Mineral Resource Lands Overlay
Figure 2. Lidar Hillshade Map
Attachment 1. Boring Logs for Expansion Area D
2/26/21
Figure 1. Area Map Showing Lateral Extent of Proposed Mineral Resource Lands Overlay
Source: Miles Sand & Gravel Company
Figure 2. Lidar Hillshade Map
Source: Miles Sand & Gravel Company
ATTACHMENT 1
Boring Logs for Expansion Area D