Report Meissner CCE BMC 200015 GEO.pdf

BLACK MOUNTAIN CONSULTING LLC

22566 SW Washington St., Ste. 206 Sherwood, OR 97140

2418 SE Ivon St. Portland, OR 97202 503.625.2517 www.blkmountain.com

Black Mountain Consulting LLC SHERWOOD Office - 22566 SW Washington St., Ste. 206 Sherwood, OR 97140

PORTLAND Office - 2418 SE Ivon St. Portland, OR 97202

503.625.2517 www.blkmountain.com

March 22, 2020

Black Mountain Project No. 200015-GEO

Columbia 911 c/o Cushing Civil Engineers 909 North Beech Street, Suite D Portland, OR 97227

Attention: Mr. Kenny McManaway

Subject: Geotechnical Engineering Evaluation Meissner Tower Site Lookout Road Deer Island, Oregon 97054

Black Mountain Consulting LLC (Black Mountain) is pleased to submit this report describing our recent geotechnical engineering evaluation for the Meissner tower site. The purpose of our work was to interpret general surface and subsurface site conditions in order to provide recommendations for design and construction. Our scope of services was authorized by Cushing Civil Engineers (CCE), and consisted of a surface reconnaissance, a subsurface exploration, geotechnical analyses, and report preparation.

We prepared this report in accordance with generally accepted geotechnical engineering practices at the time we prepared it, for the exclusive use of CCE and their agents, for specific application to this project.

Use or reliance upon this report by a third party is at their own risk. Black Mountain does not make any representation or warranty, express or implied, to such other parties as to the accuracy or completeness of this report or the suitability of its use by such other parties for any purpose whatever, known or unknown, to Black Mountain.

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We appreciate the opportunity to be of service to you. If you have any questions, or if we can be of further assistance to you, please contact us at (503) 625.2517.

Respectfully Submitted, Robert Nystrom, R.G.

Staff Geologist

EXPIRES 12-31-2020

Jeanne M. Niemer; PE, GE Principal Geotechnical Engineer

Attachment A Figures Figure 1 - Site Location Map Figure 2 - Site & Exploration Plan

Attachment B Subsurface Exploration Log

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Columbia 911

Geotechnical Engineering Evaluation

Site: Meissner

Deer Island, Columbia County, Oregon

200015-GEO

March 2020

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PROJECT DESCRIPTION

The proposed project will consist of constructing a new 150-foot tall lattice telecommunications tower and equipment shelter within a new fenced compound. The property is located on Meissner Road, near Deer Creek, Columbia County, Oregon, as shown on the attached Site Location Map, Figure 1.

SITE CONDITIONS

Regional Geology The geology of the area consists of a complex group of basalt flows, marine sedimentary rocks, and sedimentary deposits. The tower site is located on a unit of Miocene age basalt flows that include andesite lava and breccia of the Columbia River Basalt Group (Tc) (Swanson and others, 1979). The basalt flows include submarine palagonitic tuff and pillow lava. Marine sedimentary and tuffaceous rocks (Tmst) composed of tuffaceous and arkosic sandstone, tuffaceous siltstone and glauconitic sandstone deposits are found throughout this region. Quaternary sediments (Qs) composed of lacustrine and fluvial deposits are located on the eastern margins of the basalt flow, along the Columbia River. These sediments consist of unconsolidated to semi-consolidated lacustrine clay, silt, sand, and gravel and periodically include mudflow and fluvial deposits with discontinuous layers of peat (Walker, G.W. and MacLeod, N.S., 1991).

Surface Conditions The planned communication compound is located on a north-south trending ridge and is approximately level. The site is undeveloped and covered with tree stumps. An existing communication compound is located to the southwest of the proposed compound. There was no standing water present at the time of our exploration.

Subsurface Conditions We explored the subsurface conditions at the project site on March 19, 2020. Our subsurface exploration consisted of advancing one test pit, designated TP-1, as shown on the attached Site and Exploration Plan, Figure 2. We logged and classified the subsurface materials in general accordance with the Manual Visual Classification Method (ASTM D 2488).

In test pit TP-1 we encountered approximately two feet of soft silty clay that became medium stiff below four feet. We encountered soft, severely decomposed basalt at about eight feet bgs that graded to moderately weathered basalt below about ten feet. We terminated our exploration on the moderately weathered basalt at 15 feet bgs.

We did not encounter groundwater in the test pit at the time of our exploration. Well logs in the vicinity indicate that groundwater is over 100 feet bgs. Groundwater levels may fluctuate in response to changing precipitation patterns, off-site construction activities, and changes in site utilization.

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SEISMIC HAZARD STUDY

We evaluated seismic hazards based on our site explorations, analyses, experience in the vicinity of the site, and a review of available literature.

Seismic Sources There are three primary earthquake sources for this site: Cascadia Subduction Zone (CSZ) intraplate and interface earthquakes, and local crustal earthquakes that could occur in the North American Plate. CSZ intraplate earthquakes that could occur within the subducted Juan de Fuca plate are anticipated to have magnitudes on the order of 7.0 to 7.5, at a depth of about 40 to 60 km. This subduction is occurring beneath the North American Plate in the coastal regions between Vancouver Island and northern California. The fault trace is mapped approximately 50 to 120 km off the Oregon Coast. They present a low-moderate hazard.

An interface event earthquake on the seismogenic portion of the interface between the Juan de Fuca Plate and the North American Plate is capable of generating earthquakes with a moment magnitude of between 8.5 and 9.0. A magnitude 8.5 is expected to correspond to an average 10 percent of being exceeded in 50 years, and a magnitude 9.0 corresponds to an average 2 percent of being exceeded in 50 years.

Local crustal earthquakes may occur from a group of northeast and northwest trending faults to the west of the site. The nearest known fault in this group is an unnamed fault located approximately 12 km west of the site. This fault is classified as a Normal fault. There is one reported anticline fold located approximately 5.6 km northwest of the site.

Site Specific Ground Motions Our experience with ground motion modeling indicates that the site subsurface conditions are not susceptible to amplification beyond code spectra. We recommend that the code spectra for Class C given in the Recommendations section be used for design of the tower.

Liquefaction, Fault Rupture, Slope Stability and Tsunami Inundation The site soils below about eight feet consist of weathered basalt bedrock. The soils above this depth consist of soft to medium stiff silty, clay, and are not expected to be saturated. These soil types are not susceptible to settlement from liquefaction during a design level earthquake.

No faults are mapped on the site; therefore, the hazard from fault rupture is low.

The site is located inland, outside of tsunami inundation areas.

The site is relatively flat, and is therefore not susceptible to earthquake-induced slope instability.

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CONCLUSIONS

Based on the results of our site observations, explorations, and analyses, the new tower can be supported on a mat foundation that derives its support from the moderately weathered basalt that we encountered below about ten feet. Rock anchors can provide additional resistance against overturning, if required.

Our experience with subsurface conditions in the area suggests that the basalt may undulate across the area.

If preferred, a drilled pier foundation could be utilized at the site; however, if a drilled pier is chosen, a representative from Black Mountain should observe subsurface conditions during construction if pier depths extend below the depth of our exploration.

The foundation for the equipment pad should derive support from structural fill, as the soils overlying the basalt are not likely to be suitable for support of structures.

The following sections present our recommendations for design and construction of the foundation for the tower.

Seismic Conditions Based on our analysis of subsurface exploration logs and a review of published geologic maps, we interpret the on-site soil conditions to correspond to Site Class C, as defined by Table 1613.5.2 of the 2018 International Building Code.

Based on the consistency of the site soils, the potential for liquefaction settlement during a design level earthquake is negligible.

Our specific recommendations are presented in the following sections.

GEOTECHNICAL DESIGN RECOMMENDATIONS

Seismic Design Parameters

Our recommended seismic design parameters are summarized in the table below.

Seismic Design Parameters

Short Period 1 Second Mapped Spectral Acceleration Values SS=0.965 S1=0.449

Site Class C Site Coefficient Fa=1.014 Fv=1.351

Design Spectral Response Acceleration Parameters SDS=0.606 SD1=0.652

Mat Foundation Recommendations

The base of the mat foundation should be founded on the moderately weathered basalt that we encountered around ten feet bgs. After excavation to design grade, the subgrade should be cleaned of

7 | Page Black Mountain Consulting LLC | Project 200015-GEO | March 22, 2020 material loosened by excavation. Irregularities resulting from the excavation should be filled with sand, lean concrete, or other suitable material to produce a level bearing surface for the foundation.

We recommend using an ultimate static bearing capacity of 10,000 pounds per square foot (psf) for foundations bearing on the moderately weathered basalt. This bearing pressure applies to the total of dead and long-term live loads and may be increased by one-third when considering earthquake or wind loads. This static bearing pressure does not incorporate a factor of safety. We estimate post construction settlements will be less than one inch. We estimate that the differential settlement will be approximately half of the total settlement. This is a net bearing pressure. The weight of the footing and overlying backfill can be ignored in calculating footing sizes.

Lateral loads acting on the foundations can be resisted by passive earth pressure on one side of the foundation and by friction along the soil-concrete interface at the base of the foundation. We recommend using an ultimate foundation base friction coefficient of 0.70 for the basalt. A passive earth pressure of 600 pounds per-cubic-foot (pcf), expressed as an equivalent fluid unit weight, may be used for that portion of the foundation embedded more than one foot below finished exterior subgrade elevation. These lateral resistance values do not incorporate a safety factor. In order to develop these capacities, concrete must be poured neat in excavations, the adjacent grade must be level, and the static ground water level must remain below the base of the footing throughout the year. The passive pressure within the upper foot of embedment should be neglected.

Eccentric loads and moments acting on the foundation produce a skewed bearing pressure distribution to the ground. The mat foundation should be sized so that the resultant load acts within the middle third of the foundation for one-way and two-way eccentric loading to maintain a compressive contact pressure along the base of the foundation. The maximum bearing pressure from the eccentric loading must be less than the allowable bearing pressure.

Uplift loads can be resisted by the self-weight of the mat and the backfill directly overlying the embedded mat foundation. The overlying silt can be re-used as backfill over the mat provided it is prepared and placed in accordance with recommendations contained in the Structural Fill section of this report. For preliminary design purposes, the total unit weight of the overlying soils can be assumed to be 100 pounds pcf.

Excavations should be made in accordance with applicable Occupational Safety and Health Administration (OSHA) and state regulations. It is the contractor’s responsibility to select the excavation and dewatering methods, to monitor the excavations for safety and to provide any shoring required to protect personnel and adjacent improvements.

Rock Anchors If required to obtain overturning resistance, rock anchors should be installed a minimum of 10 feet into the underlying basalt. We recommend using an allowable grout/ground interface bond strength of 10 psi for the basalt on site. The upper two feet of embedment should be ignored for design purposes. The allowable grout/ground bond strength includes a factor of safety of 3. Rock anchors should be designed to meet the loading conditions as specified by the structural engineer.

Rock anchors should consist of steel bars installed in the center of a grouted drill hole. Steel bars should consist of #8 or larger deformed thread bar, in accordance with ASTM A 615, Grade 60 minimum and should be epoxy coated or hot dip galvanized for corrosion protection. The drill hole should be cleaned

8 | Page Black Mountain Consulting LLC | Project 200015-GEO | March 22, 2020 of deleterious material prior to placement of grout and steel and should be a minimum of one inch larger than the anchor diameter or as needed to provide sufficient cover between the ground and steel.

Centralizers should be placed along the steel bar at a minimum of three feet from the bottom of the steel bar and three feet from the top of the steel bar with a maximum spacing of 10 feet. Centralizers shall be fabricated from schedule 40 PVC pipe, steel, or material non-detrimental to the reinforcing steel. Wood shall not be used. Grout properties and mix design shall be as specified by the structural engineer.

Group effects should be accounted for by either providing the minimum spacing recommended below or by a reduction in capacity that can be calculated once the proposed anchor arrangement is established.

We recommend using a minimum anchor spacing of six diameters on center.

Installation records for each rock anchor should include, at a minimum, drilling equipment and procedures, ground conditions during drilling, anchor number, anchor design load, type and size of reinforcing steel, total anchor length, and grout properties.

Verification Tests: We recommend that pre-production verification testing be performed on at least one anchor to verify the design of the anchor system and the construction methods proposed prior to installing the remaining production anchors. We should review the results of the verification test prior to beginning installation of the remaining anchors. The maximum verification test load should be 200 percent of the design load, as established by the structural engineer.

Proof Tests: Proof tests should be performed on the remaining anchors to verify consistent ground conditions and construction performance. The minimum proof test load should be 120 percent of the design load.

We recommend that a representative from Black Mountain be present for the duration of rock anchor construction and testing.

Drilled Pier Design Recommendations

Axial Capacity – Skin Friction:

For frictional resistance along the shaft of the drilled piers, acting both downward and in uplift, we recommend using the ultimate skin friction values listed below. We recommend that frictional resistance be neglected in the uppermost two feet below the ground surface. The ultimate skin friction values presented do not include a safety factor, in accordance with the provisions of the EIA/TIA 222-G code.

Ultimate Skin Friction

Depth (feet) Skin Friction (psf)

0-2 2-10

10-15

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Axial Capacity – End Bearing:

We recommend that the drilled pier penetrate a minimum of five feet into the weathered basalt that we encountered at 10 feet bgs. For vertical compressive soil bearing capacity, we recommend using the unit end bearing capacities presented below, where B is the diameter of the pier in feet and D is the depth into the bearing layer in feet, in accordance with the EIA/TIA G-code. This ultimate end bearing capacity does not include a safety factor

Ultimate End Bearing Capacity Depth (feet) Bearing Capacity (tsf) Limiting Point Resistance (tsf)

10-15 15 D/B 20 Notes: D = the embedment depth (in feet) into the bearing layer. B = pier diameter (feet).

Drilled Pier Lateral Capacity

Passive Earth Pressure Method: The passive earth pressure method is a simplified approach that is generally used to estimate an allowable lateral load capacity based on soil wedge failure theory. Although the lateral deflection associated with the soil wedge failure may be estimated, design lateral deflections using the passive earth pressure method should be considered approximate, due to the simplified nature of the method. A lateral deflection on the order of one-half inch would be required to mobilize the passive pressure presented below. Our recommended passive earth pressures for the soil layers encountered at this site are presented in the table below and do not include a safety factor. They may be assumed to act over an area measuring two pier diameters wide by eight pier diameters deep.

Ultimate Lateral Passive Earth Pressures Depth (feet) Passive Pressure (pcf)

0-2 2-10

10-15

For analyzing deflection, shear, bending moment, and soil response with respect to depth, in nonlinear soils under lateral loading using the computer program LPile, we recommend using the parameters shown below.

L-Pile Input Parameters

Soil Type Depth (ft)

Effective Unit Weight

(pcf)

Strain e50

Undrained Shear Strength

(psf)

Friction Angle (deg)

Clay 2-10 100 0.01 450 0

Sand 10-15 110 - - 36

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Design parameters can be assumed to extend below the depth of our explorations for drilled piers that extend below 15 feet; however, Black Mountain MUST confirm subsurface conditions either prior to or during construction if a drilled pier option is chosen.

Drilled Pier Construction Considerations:

We did not encounter groundwater at the time of our exploration. If groundwater is encountered during drilling, it may be necessary to pump accumulated groundwater prior to pier concrete placement.

Alternatively, the use of bentonite slurry could be utilized to stabilize the drilled pier excavation.

The drilling contractor should be prepared to clean out the bottom of the pier excavation if loose soil is observed or suspected, with or without the presence of slurry or groundwater. As a minimum, we recommend that the drilling contractor have a cleanout bucket on site to remove loose soils and/or mud from the bottom of the pier. If groundwater is present and abundant within the pier hole, we recommend that the foundation concrete be tremied from the bottom of the hole to displace the water and minimize the risk of contaminating the concrete mix. We recommend that concrete be placed by tremie methods if more than 3 inches of water has accumulated in the excavation.

Spread Footings

Lightly loaded structures such as the equipment shelter can be supported on spread footings. Continuous-wall and isolated-spread footings should be at least 18 and 24 inches wide, respectively. For frost protection, the footings should be founded at least 24 inches below the lowest adjacent grades or deeper if required by local building code.

Footings should bear on the medium stiff silt that we encountered below four feet, or on a minimum two-foot thickness of compacted, granular, structural fill. The structural fill should be placed in accordance with our recommendations. Footings bearing on the silt or structural fill should be sized for an allowable bearing capacity of 2,000 psf. We estimate post construction settlements will be less than one inch for the above recommended bearing capacity. We estimate that the differential settlement will be approximately half of the total settlement. Our recommended bearing capacity is based on limiting settlements and includes a factor of safety of 3 against bearing capacity failure.

Lateral loads acting on the foundations can be resisted by passive earth pressures on the sides of the foundation and by friction along the soil-concrete interface at the base of the foundation. We recommend using an allowable passive earth pressure of 250 pounds pcf for foundations confined by the silt or structural fill placed in accordance with our recommendations. The passive pressure within the upper two feet of embedment should be neglected. We recommend an allowable coefficient of friction of 0.30.

In order to develop these capacities, concrete must be poured neat in excavations, the adjacent grade must be level, and the static ground water level must remain below the base of the footing throughout the year. These allowable lateral resistance values include a minimal factor of safety of 1.5.

Floor Slabs We recommend a 6-inch-thick layer of imported granular structural fill be placed and compacted over the prepared subgrade. The granular fill should be placed in 6-inch-thick lifts and compacted to at least 95 percent of the maximum dry density, as determined by the American Society for Testing and Materials (ASTM) D 1557. A modulus of subgrade reaction value of 75 pounds per cubic inch (pci) may be used to design the floor slab.

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Foundation Construction Considerations A geotechnical engineer from Black Mountain (or their representative) should confirm suitable bearing conditions and evaluate the foundation subgrades. Observations should also confirm that loose or soft material, organics, unsuitable fill, or old topsoil zones were removed. Localized deepening of footing excavations may be required to penetrate any deleterious materials.

Because foundation stresses are transferred outward as well as downward into the bearing soils, all footing over-excavations should extend horizontally outward from the footing edge a distance equal to one half the over-excavation depth for the structural backfill.

CONSTRUCTION RECOMMENDATIONS

Site Preparation Clearing and Stripping: After surface and near-surface water sources have been controlled, the construction areas should be cleared and stripped of organic matter and other deleterious materials. Silt fences, hay bales, buffer zones of natural growth, sedimentation ponds, and granular haul roads should be used as required to reduce sediment transport during construction to acceptable levels.

Where present, fill and existing topsoil should be stripped and removed from proposed development locations and for a five-foot-margin around such areas. Based on our explorations, we anticipate the depth of stripping will be negligible, although greater stripping depths may be required if deleterious materials are encountered. Deleterious materials encountered during site preparation should be removed from the subgrade soils and hauled off site for disposal. Stripped material should be transported off site for disposal or stockpiled for use in landscaped areas. If stripping operations occur during wet weather, a generally greater stripping depth might be required in order to remove disturbed moisture-sensitive soils; therefore, stripping is best performed during a period of dry weather.

Excavations: Where required, temporary soil cuts associated with site excavations or regrading activities should be adequately sloped back to prevent sloughing and collapse, unless a shoring box or other suitable excavation side wall bracing is provided. It is the responsibility of the contractor to ensure that excavations are properly sloped or braced for worker safety protection, in accordance with OSHA safety guidelines.

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Structural Fill The following recommendations for structural fill are provided for design and construction purposes, if required.

Materials: Structural fill includes any fill materials placed under footings and backfill over the embedded mat foundation. Typical materials used for structural fill include: clean, well-graded sand and gravel; clean sand; crushed rock; controlled-density fill (CDF); lean-mix concrete; and various soil mixtures of silt, sand, and gravel. Recycled concrete, asphalt, and glass derived from pulverized parent materials may also be used as structural fill when mixed at a ratio of 1:1 with clean gravel. Use of the on-site soils as structural fill is also feasible.

Placement and Compaction: When used as structural fill, the on-site soils should be placed in lifts with a maximum thickness of 8 inches and compacted to not less than 92 percent of the material’s maximum dry density, as determined by ASTM D-1557. The on-site soils should be moisture-conditioned to within 3 percent of the optimum moisture content (ASTM D-1557). If the on-site soils cannot be properly moisture-conditioned, we recommend using imported granular material for structural fill.

Imported granular structural fill should consist of angular pit or quarry run rock, crushed rock, or crushed gravel and sand that is fairly well graded between coarse and fine particle sizes. The fill should contain no organic matter or other deleterious materials, have a maximum particle size of one inch, and have less than 5 percent passing the U.S. No. 200 Sieve. In deep excavations, or where subgrade soils require stabilization, the particle size may be increased to four inches. The percentage of fines can be increased to 12 percent of the material passing the U.S. No. 200 Sieve if placed during dry weather and provided the fill material is moisture-conditioned, as necessary, for proper compaction. The material should be placed in lifts with a maximum uncompacted thickness of 12 inches and be compacted to not less than 95 percent of the maximum dry density, as determined by ASTM D-1557. During the wet season or when wet subgrade conditions exist, the initial lift thickness should be increased to 24 inches and should be compacted by rolling with a smooth-drum, nonvibratory roller.

CDF and lean-mix concrete do not require special placement or compaction procedures. Regardless of location or material, all structural fill should be placed over firm, unyielding subgrade soils. If earthwork takes place during freezing conditions, we recommend that all exposed subgrades be allowed to thaw and be recompacted prior to placing subsequent lifts of structural fill.

CONSTRUCTION OBSERVATIONS

Satisfactory earthwork performance depends on the quality of construction. Sufficient monitoring of the contractor’s activities is a key part ensuring that work is completed in accordance with the construction drawings and specifications. We recommend that a representative from Black Mountain observe that the subsurface conditions observed during our site investigation are consistent with those encountered during construction, and that foundation subgrades are suitable for placement of structural fill, rebar, or concrete for the new structures.

Some jurisdictions require a final letter of geotechnical compliance before they will finalize a permit. It is incumbent on the client to determine if a final letter of geotechnical compliance is required by the jurisdiction. If such a letter is required, a representative from Black Mountain MUST observe pier installation and/or foundation subgrades PRIOR to concrete being poured for the foundation. If Black

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Mountain does not perform this observation, we cannot provide a final letter of geotechnical compliance, and a permit will not be eligible for final sign-off. It is the owner’s responsibility to ensure that Black Mountain be notified in a timely manner (i.e., at least 48 hours prior to the required site observation) of the need for our services on site during construction.

CLOSURE

We have prepared this report for use by the owner/developer and other members of the design and construction team for the proposed site. The opinions and recommendations contained within this report are not intended to be, nor should they be, construed as a warranty of subsurface conditions, but are forwarded to assist in the planning and design process.

We have made observations based on our explorations that indicate the soil conditions at only those specific locations and only to the depths penetrated. These observations do not necessarily reflect soil types, strata thickness, or water level variations that may exist in other locations. If subsurface conditions vary from those encountered in our site exploration, Black Mountain should be alerted to the change in conditions so that we may provide additional geotechnical recommendations, if necessary. The future performance and integrity of the improvements will depend largely on proper initial site preparation, drainage, and construction procedures. Observation by experienced geotechnical personnel should be considered an integral part of the construction process.

The conclusions and recommendations contained in this report are based on our understanding of the currently proposed project, as derived from written and verbal information supplied to us by the client.

When the design has been finalized, we recommend that the design and specifications our firm review it to see that our recommendations have been interpreted and implemented as intended. If design changes are made, we request that we be retained to review our conclusions and recommendations and to provide a written modification or verification.

The scope of our services does not include services related to construction safety precautions, and our recommendations are not intended to direct the contractor’s methods, techniques, sequences, or procedures, except as specifically described in our report for consideration in design. Within the limitations of scope, schedule, and budget, our services have been executed in accordance with the generally accepted practices in this area at the time this report was prepared. No warranty or other conditions, express or implied, should be understood.

ATTACHMENT A

FIGURES

22566 SW Washington St., Ste. 206 Sherwood, OR 97140 TEL. 503.625-2517 | www.blkmountain.com

N

SUBJECT SITE

Base Map Courtesy of U.S.G.S. Topographic Maps “Baker Point, Oreg.” (1979) and “Trenholm, OR” (1990) Not to Scale

FIGURE 1 - Location/Topographic Map

Project : 200015

Client :Columbia 911 c/o CCE Date :March 2020

Meissner Lookout Road

Deer Island, Oregon 97054

Location

22566 SW Washington St., Ste. 206 Sherwood, OR 97140 TEL. 503.625-2517 | www.blkmountain.com

N

FIGURE 2 - Site & Exploration Plan

Project : 200015

Client :Columbia 911 c/o CCE

Drawing provided by Cushing Civil Engineering, Not to Scale

TEST PIT

TP-1

(APPROXIMATE)

Date :March 2020

Meissner Lookout Road

Deer Island, Oregon 97054

Location

ATTACHMENT B

SUBSURFACE EXPLORATION LOG

GEOTECHNICAL TEST PIT LOG

22566 SW Washington St., Suite 206 Sherwood, Oregon 97140

TEL:503.625.2517

Test Pit No.:Job Number: 200015-GEO Elevation Reference :

Ground Surface Elevation : OBSERVATIONS

TESTING

Page:

LEGEND

Test Pit Start Date: 3-19-20 Test Pit Completion Date: 3-19-20 Logged By:

Perched Groundwater

DATE

Static Water Level Grab Sample

NWTPH-HCID

VOCs Type of Analytical Testing Used

RN

TP-

Meissner Lookout Road Deer Island, Oregon 97054

Soft, moist, brown-oxidized, silty CLAY (CL), organics (medium to large roots)

John Deere 410E Extendahoe

RK - BASALT (moderatedly weathered RH2), gray, moderately fractured

Test pit terminated, due to extent of reach, at approximately 15 feet bgs.

No groundwater, seeps or seams encountered at the time of exploration.

T-Probe to 16", slightly plastic to 8'

T-Probe to 5"

Increase in digging resistance noted below 10’

RK - BASALT (severely weathered RH1), red-oxidized-gray, closely fractured

Occasional basalt boulders (up to 12" diameter), no caving becomes medium stiff, reddish-brown below 4’ 2.5