TABLE OF CONTENTS 6. LABORATORY ANALYSIS 6.1 INDEX PARAMETERS PHYSICAL PARAMETERS CHEMICAL PARAMETERS

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S11187 Lind WWTP - TOC

TABLE OF CONTENTS

1. CONTEXT

1.1 PROJECT CONSIDERATIONS 1-1

1.2 LOCATION 1-1

1.3 SCOPE 1-1

2. ENCOUNTERED CONDITIONS

2.1 GEOLOGIC SETTING 2-1

2.2 SURFACE CONDITIONS 2-2 2.3 SUBSURFACE CONDITIONS 2-3

2.4 SURFACE AND GROUNDWATER HYDROLOGY 2-3

3. CONCLUSIONS 3-1

4. RECOMMENDATIONS

4.1 EARTHWORK 4-1

4.2 FOUNDATIONS 4-2

4.3 LATERAL EARTH PRESSURES 4-2 4.4 FLOOR SLABS 4-3

4.5 DRAINAGE 4-3

4.6 ADDITIONAL SERVICES 4-4

5. FIELD EXPLORATION

5.1 TEST BORINGS 5-1 5.2 TEST PITS 5-1 5.3 SOIL SAMPLES 5-2 5.4 SOIL & ROCK CLASSIFICATION 5-2

5.5 LOCATION 5-2

6. LABORATORY ANALYSIS

6.1 INDEX PARAMETERS 6-1 6.2 PHYSICAL PARAMETERS 6-1 6.3 CHEMICAL PARAMETERS 6-1

7. LIMITATIONS 7-1

EMBEDDED TABLES Table No. Description

2.1 SPECTRAL RESPONSE ACCELERATION PARAMETERS 2.2 INFILTRATION TEST RESULTS

4.1 RETAINING WALLS 4.2 LATERAL RESISTANCE

ATTACHED FIGURES Figure No. Description

1 VICINITY MAP

2 SITE PLAN – PLANT SITE

3 SITE PLAN – INFILTRATION AREA 4 GUIDE TO SOIL & ROCK DESCRIPTIONS 5-1 to 5-8 BORING LOGS

6 LABORATORY SUMMARY

7-1 to 7-2 GRAIN SIZE DISTRIBUTION RESULTS

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S11187LIND WWTP-CHAPTER 1

Budinger & Associates, Inc. 1-1

1. CONTEXT

This report presents the results of geotechnical exploration and analysis for a new wastewater treatment facility and associated developments for the Town of Lind, Washington. Our work was coordinated and contracted with USKH (Alan Gay, PE).

1.1 PROJECT CONSIDERATIONS

Planned improvements include construction of a new, 44 by 37-foot, 16-foot tall concrete treatment vessel to contain up to 14 feet of liquid, an adjacent lift station headworks, and a 75 by 25-foot building containing an office, lab, blower, sludge management room, and storage. A preliminary site plan of the plant with proposed improvements was provided. An alternate location for the new headworks, separate from the control building, was also provided. The final grading plan and floor slab elevations for proposed structures were not provided at the time of this report. Additional improvements include an aeration basin, wastewater handling system, sludge drying beds, dried solids storage area, outfall, driveways, sidewalks, and other miscellaneous improvements. New stormwater handling facilities are planned.

The heaviest structural loads would be associated with the headworks, screens, and lift station. Preliminary structural loads of up to 50 thousand pounds (kips) isolated and 2 kips per lineal foot (klf) were provided. We recommend that the structural engineer review these values. Excavated cuts on the order of 8 feet are anticipated for construction of below grade structures.

Proposed sewer system improvements are to extend from the existing wastewater collector to the new head works, illustrated on the Plant Site Plan. The existing plant structures are scheduled to be demolished. In addition, the western field adjacent to the plant site may be used for land application of effluent (Land Application Site).

Previous work near the site included Budinger Report Number H10103, Land Application Site in Lind, WA. In the previous exploration, a series of borings were hand augured, samples were collected, and laboratory flexible wall permeability tests were completed in the land application area west of the plant site.

1.2 LOCATION

The site is located in Lind, Washington, as illustrated in the attached Vicinity Map and Site Plan. Lind is located in section 25, Township 22 N, Range 21 East, Willamette Meridian, Washington. The project extends from the west limit of the Town of Lind to Lind Coulee along State Highway 21. It lies approximately 8 to 10 feet above the Lind Coulee drainage.

1.3 SCOPE

This geotechnical study entailed interpretation of the surface and subsurface conditions to provide conclusions as to the suitability of the geotechnical conditions to support the proposed improvements and to provide geotechnical parameters needed for others to design and construct. We endeavored to conduct these services in accordance with generally accepted geotechnical engineering practices as outlined in the proposal (Proposal No.

115S11), dated May 2, 2011.

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Construction inherently entails risk and this project is not an exception. The purpose of this study is to reduce risks related to subjects in the scope to levels generally accepted for similar projects designed with the benefit of similar geotechnical study.

As outlined in our proposal, the following scope was completed.

• Conduct 4 test pit explorations and 4 test borings with thin wall sampler and split spoon sampling methods; log subsurface conditions and collect samples.

• Collect representative soil samples to refine the identifications made in the field and determine specific parameters for subsequent geotechnical analysis.

• Characterize surface and subsurface conditions significant to the geotechnical aspects of the project – including geology, seismology, topography, existing surface features, existing fill, and stratigraphy (layering) of materials.

• Analyze geotechnical conditions to develop conclusions and recommendations addressing foundation design, including bearing capacity and settlement.

• Perform 12 borehole infiltration tests at depths of 4.3 to 8 feet below ground surface for field estimation of hydraulic conductivity (k).

• Prepare a geotechnical engineering report.

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2. ENCOUNTERED CONDITIONS

The conditions described in this chapter are based on results of the field and laboratory testing, summarized in Chapters 5 and 6.

2.1 GEOLOGIC SETTING

Source: Washington State Department of Natural Resources, Division of Geology and Earth Resources.

The site is underlain by the Miocene-age Saddle Mountains Basalt Formation overlain by the Frenchman Springs member of the Wanapum Basalt Formation. The Wanapum Basalt Formation is exposed on the ground surface and in drainage channel sidewalls. Quaternary age sediments mapped in the Lind Coulee drainage channel include glacial outburst flood deposits of sand and gravel (Qfg), alluvium (Qa), and loess of the Palouse Formation (Ql).

Catastrophic glacial flood episodes scoured the basalts and the Palouse Formation.

Agricultural soil typed at the site were mapped by the Natural Resource Conservation Service (NRCS) as Esquatzel silt loam, 0 to 2 percent slopes.

SEISMIC CONSIDERATIONS

Washington State Department of Natural Resources has defined the liquefaction potential of the Lind Coulee and surrounding sediments as moderate to high.

A synclinal fold was mapped 2 miles south of the site. The syncline axis trends parallel to the overall direction of Lind Coulee. This geologic structure has not been known to be active in recent geologic time.

We understand the 2009 International Building Code (IBC) will be used as the basis for design of the proposed structures. The Site Class was determined in accordance with Table 1613.5.2 in the IBC. Based on results of standard penetration tests and laboratory analyses, the subsurface conditions appear to meet the criteria for Site Class D.

The seismic parameters were calculated using the USGS Earthquake Ground Motion Parameters software, version 5.1.0. The published USGS values of predicted earthquake ground motion for short period structural elements (0.2 second spectral response acceleration, Ss) and for long period structural elements (1.0 second spectral response acceleration, S1), adjusted for site class effects, are presented in Table 2.1 below. The design parameters (SDS and SD1) are equal to 2/3 of the maximum earthquake spectral response accelerations (SMS and SM1).

Table 2.1 Spectral Response Acceleration Parameters Site

Class Latitude Longitude SMS SM1 SDS SD1

D 46.970 N -118.633 W 0.548g 0.271g 0.365g 0.181g

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2.2 SURFACE CONDITIONS

The ground surface at the plant site is covered with a thin layer of silty topsoil and gravel.

It is surrounded with a soil berm approximately 4-feet tall, intended to isolate water from the drainage in the event of a wastewater system overflow.

The site topography is characterized by a native terrace, gently sloping (< 3.5 %) to the south and terminating at the drainage embankment. The creek embankment slopes steeply to the drainage channel approximately 10 feet below the terrace.

Adjacent properties include open fields to the west and to the east. State Highway 21 and the right of way define the north boundary. Lind Coulee borders the site to the south, and BNSF railroad tracks run along the south side of the Coulee. The railroad grade trends southwest to northeast and crosses the Lind Coulee at the southeast corner of the site.

2.3 SUBSURFACE CONDITIONS

Materials encountered in explorations include (1) Topsoil, (2) Sandy Silt, and (3) Basalt rock . The encountered soil conditions are described in the attached Boring Logs.

Characteristics of materials encountered are summarized below.

TOPSOIL

Topsoil was encountered in test pits from ground surface to approximately 0.5 feet. The topsoil unit was generally light brown. At the plant site, a thin layer of gravel covered the light brown silty ground surface.

SANDY SILT

Alluvial sandy silt to silt with fine sand was encountered in test pits and borings below the topsoil. The silty sand varied in color from light brown to dark brown and the condition was loose to depths of 8 to 13 feet and medium dense below. In-place unit weight ranged from 77 to 80 pounds per cubic foot (pcf) in the loose zone. The in-place unit weights correspond to a moderate collapse potential common for soils in the Palouse Region. The composition of the sandy silt unit was relatively uniform throughout the site and the sand content increased slightly with depth. These alluvial soils were deposited in a submerged environment and may be considered normally consolidated.

The sandy silt exhibited low cohesion and was non-plastic (see Laboratory Summary).

Boring cuttings readily dried into blowing dust and quickly segregated into a flowing powder when saturated. The natural moisture of the sandy silt was slightly moist to moist in soils above groundwater. Orange mottling and grayish green colors were observed in borings where soils were likely saturated below 16 to 19 feet. The measured pH of the sandy silt was slightly alkaline at 8.4. Variable gravel content was observed in the northern portions of the site above 1336 feet in explorations 301 and 306. The gravel encountered was subangular to subrounded and consisted of mostly basalt rock fragments. Boring refusal occurred after penetrating approximately 2 feet into the sandy silt with gravel without encountering basalt rock.

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BASALT

Basalt rock was encountered at 19 feet below ground surface (BGS) in Boring 4. Some large basalt gravel fragments were encountered at 18.5 feet just above the basalt, in the Sandy Silt unit. The basalt was moist, dark gray, and very hard. No indication of ground water was present in the boring. Basalt was not encountered in other explorations to depths up to 21 feet.

2.4 SURFACE & GROUNDWATER HYDROLOGY

Free groundwater was not observed at the time of exploration. Groundwater likely occurs at 16 to 19 feet BGS as indicated by wet soils and mottling observed in borings at those depths. Fluctuations in ground water levels can be attributed to seasonal water levels in the Lind Coulee.

Review of well logs obtained from the Washington State Department of Ecology indicate that ground water for domestic wells occurs from 120 to 187 feet below ground surface (BGS) within fracture zones in the Wanapum Basalt or below the basalt layer.

Field permeability testing was conducted at 12 locations across the site as illustrated on the Site Plans. The testing program was completed in accordance with USBR 7300 Field Permeability by the Well Permeameter Method.

Permeability rates in the bermed wastewater facility area ranged from 0.11 in/hr to 0.27 in/hr as indicated in the Plant Site Plan. Infiltration rates in the western infiltration area ranged from 0.21 in/hr to greater than 1.2 in/hr as indicated in the Western Infiltration Site Plan. Permeability test results are summarized in Table 2.1 below.

Table 2.2 Infiltration Test Results Exploration Boring depth

(ft) k (cm/sec) k (in/hr) 301 7.6 4.2x10^-4 0.60 302 5 > 8.5x10^-4 >1.2 303 8 > 8.5x10^-4 > 1.2 304 8.2 > 8.5x10^-4 > 1.2 305 7.2 > 8.5x10^-4 > 1.2 306 4.3 > 8.5x10^-4 > 1.2 307 8 7.7x10^-5 0.19 308 8.4 1.9x10^-4 0.27 309 8.6 > 8.5x10^-4 > 1.2 310 8.1 5.4x10^-4 0.76 311 8.6 1.5x10^-4 0.21 312 8.1 4.8x10^-4 0.68

The highest infiltration rates were measured in the southwestern half of the western

infiltration area at test locations 302 through 305 and also to the north along the highway at test location 306. A permeability rate of 8.5x10^-4cm/sec (1.2 in/hr) corresponds to a well permeameter infiltration rate of 1 gallon per minute at the boring depth at which the test was performed.

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S11187 LIND WWTP - CHAPTER 3

3. CONCLUSIONS

Based on the encountered conditions described in Chapter 2, we conclude that the

geotechnical conditions of the site are acceptable for support of the proposed improvements.

Native soils on site consist of loose, Sandy Silt to depths of 8 to 13 feet. Loose soils possess moderate collapse potential, typical of silty Palouse Loess found in this region. To decrease collapse potential and improve foundation support, native soils could be replaced with compacted structural fill in zones of high stress, such as within a depth equal to the footing width.

The native Sandy Silt appears to be suitable, though not favorable, for use as structural fill below a depth of 2 feet BGS. Silty soils are moisture sensitive and can become unstable under construction traffic when highly saturated.

Construction of the concrete treatment vessel and adjacent lift station may require relatively deep excavations. Steep temporary slopes are likely to become unstable if the soil is allowed to dry or is subjected to loads or vibrations.

Groundwater in the area is likely perched on the Basalt, which was encountered at 19 feet BGS. Groundwater levels are likely to fluctuate seasonally as indicated by wet soils and mottling found at depths from 16 to 19 feet BGS. Deeper excavations may encounter groundwater and these operations should be avoided during wet season. Contractors should be prepared to dewater deep excavations.

Low permeability rates and relatively shallow depth to seasonal groundwater and basalt rock suggest that the use of infiltrative drywells may not be feasible for stormwater disposal within the bermed treatment facility area.

Permeability rates in the western infiltration area indicate that effluent disposal in that area is likely feasible. The southwestern half of the infiltration area would likely support the highest effluent infiltration rates.

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4. RECOMMENDATIONS

These recommendations are intended to provide the geotechnical criteria required for an economically feasible design at normally accepted risk levels. More conservative design parameters may be used if lower risks are preferred. Specifically, the design and

construction should incorporate the following recommendations concerning bearing and settlement conditions for foundations, drainage, and earthwork criteria.

4.1 EARTHWORK

Soft and disturbed areas should be excavated and backfilled with structural fill in accordance with the recommendations in this report.

Basalt rock was encountered, but was found below the maximum anticipated excavation depth of 16 feet.

TEMPORARY SLOPES

Soils in the area may be classified as Type C according to OSHA Regulations. OSHA criteria allows a maximum inclination of 1.5H:1V (Horizontal:Vertical) in the temporary condition for Type C soils.

PREPARATION OF SURFACES TO RECEIVE FILL

We recommend removing the Topsoil to prepare surfaces below foundations and slabs. We anticipate the Topsoil layer to be approximately 6 inches thick in proposed construction areas. Surfaces to receive fill and backfill should be excavated to a nearly level, undisturbed subgrade with maximum slopes of 8 percent.

FILL MATERIAL

Fill used to establish planned grades may consist of native Sandy Silt. However, the Sandy Silt characteristics are marginal and this material may not be feasible to use if the moisture content exceeds optimum. More favorable import should consist of sand or gravel with no more than 10% fines (percent passing the #200 sieve) and should be one of the following soil types: SW, GW, SP, or GP or soil of dual symbol such as SW-SM.

Pipe bedding and backfill for utilities such as sanitary sewer or water should be in accordance with Washington Department of Transportation (WSDOT) Standard Specifications Sections 7-08.3(1)C and 9-03.12(3).

FILL PLACEMENT

Place fill in nearly level lifts and compact to at least 92% of maximum dry unit weight. If necessary, moisture-condition the soils to within an appropriate range of optimum moisture content (typically ± 2%). Obtain the maximum unit weight and optimum moisture content for fill material in accordance with the Modified Proctor (ASTM D 1557).

Lift thickness should vary with equipment capability up to a maximum of 10 inches thick.

Hand-operated tamping equipment should be used to compact thin lifts not exceeding 4 inches. A qualified soils technician representing the Geotechnical Engineer should be present during fill and backfill operations to monitor subgrade preparation and compaction of each lift of fill.

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4.2 FOUNDATIONS

We recommend founding the proposed building on conventional spread footings bearing on the undisturbed Sandy Silt or acceptable structural fill as described in Earthwork. Structural fill should be placed at a depth no less than the footing width and wider by a ½ horizontal to 1 vertical projection out from the footing edges. Structural fill placed below footing and slabs should be enveloped in geotextile fabric to provide a separation layer from native soils. The minimum recommended embedment depth to the base of footings is 30 inches.

BEARING PRESSURES

The maximum recommended bearing pressure is 1650 pounds per square foot (psf). Bearing pressures presented are intended to include dead-load plus sustained live-loads (such as snow, etc), but may exclude 75% of the subterranean footing weight. Bearing pressures can be increased by 1/3 when considering short duration live loads.

TEMPORARY LIVE LOADS

Seismic design parameters based on the 2009 International Building Code are described in Seismicity (Section 2.1).

SETTLEMENT

Based on an average N-Value of 10, the total foundation settlement for structures bearing on undisturbed native Sandy Silt was estimated to be less than 1 inch.

4.3 LATERAL EARTH PRESSURES

RETAINING STRUCTURES

Assuming drained conditions and level backfill, the lateral earth pressures against retaining structures may be calculated using the Active or At-Rest pressures presented in Table 4.1 on the following page. The presence of slopes and surcharge loads above a wall will cause an increase in earth pressure. Appropriate safety factors should be applied in retaining wall design. Since some displacement is required to mobilize the full active strength (approximately 0.2% of the wall height), the At-Rest pressure factors must be used when retaining structures are rigidly restrained to limit yield under earth pressure.

Table 4.1 Retaining Walls

EQUIVALENT FLUID PRESSURE

STRATUM ACTIVE AT REST

Native Sandy Silt or Similar

Structural Fill 40 psf/ft 65 psf/ft

LATERAL RESISTANCE

Lateral forces can be transferred to the soil with the passive earth pressures, together with the earth/concrete friction factors presented in Table 4.2 below. These values are

unfactored and apply to a properly compacted, horizontal backfill surface. They will be substantially reduced when densities are less than those recommended under Earthwork and when the surface is sloped.

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Table 4.2 Lateral Resistance

EQUIVALENT FLUID PRESSURE

STRATUM

EARTH/CONCRETE FRICTION FACTOR

PASSIVE EARTH CONDITION DRAINED

Native Sandy Silt or Similar

Structural Fill 0.35 350 psf/ft

4.4 FLOOR SLABS

We recommend placing a minimum thickness of 4-inches of crushed gravel as a leveling course under slabs. Repair surface irregularities caused by normal construction activities (wheel ruts, frost heave, etc.) thoroughly in order to place the slab on a smooth and compacted subgrade.

We recommend moisture protection for floor slabs if moisture sensitive flooring will be installed (carpet, linoleum, etc.) or if slab moisture is a concern for other reasons such as humidity control, installation of moisture sensitive equipment, etc. The combination of a durable, impermeable membrane and open-graded gravel provides the best means of slab moisture control, in our opinion.

Backfill adjacent footings and underlying utility excavations in accordance with the recommendations described under Earthwork to provide uniform slab support. We recommend designing footings that are isolated from floor slabs to avoid disruption of the slabs caused by differential footing movement.

4.5 DRAINAGE

We recommend grading the site to direct stormwater runoff away from the proposed structures to a stormwater drainage system. Final graded surfaces should be afforded erosion protection by mechanical or biotechnical means. Runoff should be collected and disposed of to prevent accumulation near treatment facility structures and irrigation should be minimized in areas adjacent to structures.

Permeability rates determined from field testing indicate that site conditions are poorly suited for rapid infiltration methods of stormwater disposal. Low permeability of the Sandy Silt may limit potential for onsite disposal of stormwater using conventional subsurface infiltration structures such as drywells. Single depth drywells may be considered to supplement swales by increasing storage capacity but should not be considered to add exfiltration capacity.

Swales should be sized appropriately to accommodate stormwater runoff. Swale bottom infiltration rates used in design should be based on permeability test results from the nearest adjacent test locations, see Site Maps and Table 2.1. Infiltration rates used in design should be divided by a safety factor of 3.0, assuming a minimum of 4 feet of separation from underlying groundwater.

Utilize the permeability rates presented in Table 2.1 for design of the land application system. Apply an appropriate safety factor of at least 3.0.

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4.6 ADDITIONAL SERVICES

Soil and foundation engineering comprises a 5-part endeavor involving cooperation with the owner, designer, and constructor as follows:

1. Preliminary evaluation to assist in planning and to economically adapt the project to its geologic environment.

2. Soil exploration and analysis to evaluate subsurface conditions and recommend design criteria.

3. Consultation with the designer to verify adaptation of the specific design to the site in accordance with the recommendations.

4. Monitor fill placement to verify proper compaction.

5. Construction observation to verify the conditions encountered and to make recommendations for modifications as necessary.

This report satisfies item 2 of this 5-part endeavor. We are eager to provide assistance with design and construction as appropriate to assist in completing a safe and economical project.

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5. FIELD EXPLORATION

The field activities were conducted by our staff geologist David Lehn, L.G. and licensed driller Ethan Hagman, under the supervision of our geotechnical engineer, John Finnegan, PE, on June 16, July 1, and July 22, 2011. The field activities are summarized in Chapter 1 and described in the sections below.

The field activities generally consisted of the following:

• 4 Test Pit Excavations performed by Gary Bittick.

• Hollow stem auger drilling of 10 bore holes to depths of approximately 8 to 21 feet.

• Hand auger boring of 6 infiltration holes from 4.3 to 8 feet.

• Soil sampling using Standard Penetration Tests, Shelby Tube sampling, and collecting cuttings; logging of test borings.

• Infiltration testing in 6 of the boreholes.

• Site reconnaissance

Methods of exploration are provided below; while, results are provided in Tables and Figures listed in the Table of Contents.

5.1 TEST BORINGS

FLIGHT AUGER DRILLING

Ten borings were drilled using an ASV mounted Longyear 28 drill rig or a Mobile B-57 drill rig utilizing 3-¼ inch I.D. (8 inch O.D.) hollow stem continuous flight auger.

Sampling was conducted through the internal annulus of the hollow stem auger. The soils were relatively easy to penetrate with flight auger equipment. The borings were backfilled with a mixture of native soils and bentonite chips unless infiltration testing was conducted.

Infiltration tests utilized gravel filled borings with a continuous screen. Conditions encountered are presented in the attached Boring Logs (Figures 4-1 to 4-4).

FIELD PERMEABILITY TESTING USBR 7300 Field permeability testing was conducted at 12 locations as illustrated on the Site Plans following the USBR 7300 Field Permeability by the Well Permeameter Method. The field tests extended to depths of 4.3 to 8-feet. Constant infiltration rates were measured and subsequent drawdown measurements were made for 30 minutes or until drawdown was completed.

5.2 TEST PITS

Shallow test pits were excavated with a backhoe and a 24 inch bucket to obtain bulk samples of the underlying materials for testing. Excavations were performed by Gary Bittick of Lind, WA.

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5.3 SOIL SAMPLES

STANDARD PENETRATION TESTS ASTM D 1586 To obtain soil samples, Standard Penetration Tests (SPT) were conducted by driving a 2- inch O.D. split-spoon sampler with a 140-pound hammer actuated by a cathead/rope assembly or Mobile automatic hammer to provide a test of penetration resistance.

The resulting blow count for each foot of sampler advancement, representing uncorrected N-values, is presented in the Boring Logs.

THIN WALL (SHELBY) TUBE SAMPLES ASTM D 1587 Thin-walled tubes, 1/16 inch thick x 3 inch O.D. x 2 ft in length were pushed into the ground with a hydraulic ram mounted on the drill rig at locations described in the Boring Logs to provide relatively undisturbed samples.

CUTTING SAMPLES

As the auger boring is advanced the flights raise soil cuttings to the surface. Preliminary field identification of the soil may be made on the recovered material.

BULK SAMPLES ASTM D 75

Bulk samples, representative of the subgrade material, were collected from test pits at the project site and submitted for laboratory testing.

5.4 SOIL & ROCK CLASSIFICATION

UNIFIED SOIL CLASSIFICATION SYSTEM ASTM D 2487 The encountered soils and rock were classified visually from split-spoon samples,

observation of cuttings, and drill rig response. The descriptions presented on the Boring Logs are intended to comply with the Unified Soil Classification System (USCS) described in the Guide to Soil & Rock Descriptions, which is recognized internationally in the fields of engineering and construction.

5.5 LOCATION

HORIZONTAL & VERTICAL CONTROL

The boring locations were measured with a cloth tape from physical features such as the surveyors Control Point, GPS, and State Highway 21 as depicted on the plan provided by the client. Vertical locations of on-site borings were measured relative to CP#3 with a laser level while offsite borings and test pits were estimated relative to client provided topographic survey. Horizontal and vertical locations can be considered accurate to ±5 and ±1 feet, respectively, relative to the information provided.

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6. LABORATORY ANALYSIS

Laboratory testing was performed on representative samples of the soils encountered to provide data used in our assessment of soil characteristics. The tests were chosen to assess moisture content and grain-size distribution.

Tests were conducted, where practical, in accordance with nationally recognized standards (ASTM, AASHTO, etc.), which are intended to model in-situ soil conditions and behavior.

The results are illustrated in figures as listed in the Table of Contents.

6.1 INDEX PARAMETERS

MOISTURE CONTENT ASTM D 2216

Moisture contents were determined by direct weight proportion (weight of water/weight of dry soil), obtained by drying soil samples in an oven until reaching constant weight.

GRADATION ASTM D 422

Gradation analysis was performed by the mechanical sieve method. The mechanical sieve method is utilized to determine particle size distribution based upon the dry weight of sample passing through sieves of varying mesh sizes.

ATTERBERG LIMITS AASHTO T-90

Atterberg limits were determined for a representative sample of the native soil. Atterberg Limits describe the properties of a soil’s fine-grained constituents by relating the water content to the soil’s limits of engineering behavior. As the water content increases, the state of the soil changes from a brittle solid to a plastic solid, and then to a viscous liquid.

The Liquid Limit (LL) is the water content above which the soil tends to behave as a viscous liquid. Similarly, the Plastic Limit (PL) is defined as the water content below which the soils tend to behave as a brittle solid. The Plasticity Index (PI) describes the range of water contents over which a soil is plastic and is derived by subtracting the PL from the LL.

6.2 PHYSICAL PARAMETERS

DRY UNIT WEIGHT ASTM D 2937

Dry unit weight was determined for samples obtained from Shelby Tubes. Unit weight is calculated by a direct weight per volume measurement (weight of dry soil/volume of soil in the sample tube).

6.3 CHEMICAL PARAMETERS

pH ASTM G 51

Certain clayey soils can contain excess acidity that attacks concrete and iron. Corrosive potential of embedded iron and steel can be quantified by determining the pH (acidity = pH

<7) and minimum resistivity of soil. Buried conduit, culverts, and reinforcing will deteriorate rapidly under acidic conditions. Cathodic protection is used to protect such components.

Neutral pH (7±1) represents the least corrosive potential with less protection measures.

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7. LIMITATIONS

The conclusions and recommendations presented herein are based upon the results of the field and laboratory explorations presented in Chapters 5 and 6. They are predicated upon our understanding of the project, its design, and location as defined in Chapter 1.

We endeavored to conduct this study in accordance with generally accepted geotechnical engineering practices in this area. This report presents our professional interpretation of investigation data developed, which we believe meets the standards of the geotechnical profession in this area; we make no other warranties, express or implied.

Unless test locations are specified by others or limited by accessibility, the scope of analysis is intended to develop data from a representative portion of the site. However, the areas tested are discreet. Interpolation between these discreet locations is made for illustrative purposes only, but should be expected to vary. If a greater level of detail is desired, the client should request an increased scope of exploration.

This study was not specifically intended to provide information for cost estimation. While we realize that this report may present information, which could be used for bidding, it was not intended for that purpose. If it were, different field procedures would likely have been used to more reliably assist the estimator. Consequently, use of this information for bidding purposes is strictly at the contractor's risk.

Likewise, this study deals with physical characteristics of the soil encountered on the site.

Chemical characteristics, including identification of dangerous chemicals or hazardous materials, are beyond the scope of this exploration. The delineation of wetlands is also beyond the scope of this report. If conditions are encountered which vary from those described in this report, they should be brought to our attention immediately so that these recommendations may be re-evaluated.

Changes in engineering standards, code requirements, or general improvements of the state- of-the-art, could render this exploration less than adequate at a future date. Consequently, if the proposed construction is not started within one year, this report should be re-evaluated prior to application.

The conclusions and recommendations presented herein are intended for design and construction of the currently proposed project as described in Project Considerations.

Changes in alignment, layout, loads, or construction material should be brought to our attention so that we may reassess the applicability of these recommendations.

Furthermore, as project success depends on the proper application of these

recommendations in both design and construction, we cannot accept liability in cases where these recommendations are not applied or followed as intended. Consequently, any liability on our part must be accompanied by our retention to assist the owner and designer in properly implementing these recommendations as defined in Additional Services.

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dry, dark gray, loose moist, brown, loose

medium dense

wet, greenish gray, medium dense

no free groundwater observed

8

9

22

10 (90%)

(93%)

(97%)

(100%)

Well graded GRAVEL SILT with Sand

(groundwater indicated from wet soils at 16 ft.) Mottled (0.1 foot of pink fine sand on top of greenish gray Silt)

End of Boring @ 21.5 ft

7-1-11

FIGURE 5-1 BORING LOGS

SOIL LOG

Elevation:

Location:

STANDARD PEN TEST, N-VALUE (OBSERVED)

RQD, BLOW COUNTS N (% RECOVERY)

Logged by:

MOISTURE, COLOR, CONDITION

TEST BORING B-101

ATTERBERG LIMITS PL WATER CONTENT

3" SPLIT SPOON PENETRATION, BLOWS/FT

0

5

10

15

20

25

30

96 (CP#3=100) ft Budinger & Assoc., Inc.

Mobile B-57 with automatic SPT hammer

Approximately 10 feet N of nw corner of existing Bldg gravel

10 20 30 40 50 60 70 80 90

Size of hole:

SAMPLES

DESCRIPTION

Date of Boring:

Surface:

Project: Lind WWTP Location: Lind, WA

D.Lehn

6.5" O.D. (3-1/4" I.D.) hollow stem auger

DEPTH

LL

Type of Drill:

TEST RESULTS

Driller:

ITHOUT WELL WITH TESTS S11187 LIND WWTP.GPJ BUDINGER.GDT 7/21/11

(22)

dry, dark gray, loose moist, light brown, loose

(Offset SPT by 3 ft SW)

brown, medium dense

dark brown

wet, greenish gray, medium dense no free groundwater observed

7

8

17

15 (100%)

(73%) (100%)

(80%)

(90%)

(100%)

(Infiltration test @ 8 ft. 0.10 cfm for 1 hr.

Drawdown 4.5 ft. in 30 min)

(groundwater indicated from wet soils at 19 ft.) Mottled

End of Boring @ 21 ft

7-1-11

SOIL LOG

Elevation:

Location:

Logged by:

0

5

10

15

20

25

30

Mobile B-57 with automatic SPT hammer SW corner of sludge drying bed

gravel

10 20 30 40 50 60 70 80 90

Size of hole:

SAMPLES

DESCRIPTION

Date of Boring:

Surface:

D.Lehn

DEPTH

LL

Type of Drill:

TEST RESULTS

Driller:

LL WITH TESTS S11187 LIND WWTP.GPJ BUDINGER.GDT 7/21/11

(23)

dry, dark gray, loose moist, brown, loose

medium dense

wet, greenish gray, medium dense

7

6

10

21

22 (73%)

(90%)

(100%)

(73%)

(100%)

(Infiltration test @ 8 ft. 0.08 cfm for 1 hr.

Drawdown 6 ft. in 30 min)

(groundwater indicated from wet soils at 15 ft.)

End of Boring @ 21 ft

7-1-11

SOIL LOG

Elevation:

Location:

Logged by:

0

5

10

15

20

25

30

Mobile B-57 with automatic SPT hammer Approximately 30 feet east of clarifier gravel

10 20 30 40 50 60 70 80 90

Size of hole:

SAMPLES

DESCRIPTION

Date of Boring:

Surface:

D.Lehn

DEPTH

LL

Type of Drill:

TEST RESULTS

Driller:

ITHOUT WELL WITH TESTS S11187 LIND WWTP.GPJ BUDINGER.GDT 7/21/11

(24)

dry, light brown, very loose

moist, brown, loose

wet, medium dense

dry to moist, black, very hard

7

9

15

R (100%)

(100%)

(60%)

SILT (Topsoil) SILT with Sand

(groundwater indicated from wet soils at 16 ft.)

SILT

Basalt gravel and basalt bedrock End of Boring @ 20 ft

6-17-11

SOIL LOG

Elevation:

Location:

Logged by:

0

5

10

15

20

25

30

96 ft Budinger & Assoc., Inc.

Longyear 28

Approximately 110 feet west of CP#3 grass and weeds

10 20 30 40 50 60 70 80 90

Size of hole:

SAMPLES

DESCRIPTION

Date of Boring:

Surface:

D. Lehn

DEPTH

LL

Type of Drill:

TEST RESULTS

Driller:

LL WITH TESTS S11187 LIND WWTP.GPJ BUDINGER.GDT 7/21/11 +100

(25)

Sandy SILT slightly moist, light

brown, loose moist, brown, loose

Sandy SILT

End of Excavation @ 7.7 ft

6-17-11

0

5

10

15

20

25

30

D.Lehn

FIGURE 5-5

SOIL LOG

Elevation:

TEST PIT 201

2x6 ft.

Location:

Surface:

Bittick

DEPTH DESCRIPTIONDESCRIPTION

Equipment:

D.Lehn

TEST PIT LOGS

Date:

Size of hole:

Logged by:

FIGURE 5-5

SOIL LOG

SAMPLE

1337 ft Logged by:

Date: 6-17-11

0

5

10

15

20

25

30

Elevation:

DEPTH

1337 ft Backhoe

N side of W half of W infiltration area grass and weeds

Excavator:

TEST PIT LOGS

RD TEST PIT S11187 LIND WWTP.GPJ BUDINGER.GDT 7/29/11

(26)

SILT (Topsoil) SILT with Sand slightly moist, light

6-17-11

0

5

10

15

20

25

30

D.Lehn

FIGURE 5-6

SOIL LOG

Elevation:

TEST PIT 202

2x6 ft.

Location:

Surface:

Bittick

Equipment:

D.Lehn

TEST PIT LOGS

Date:

Size of hole:

Logged by:

FIGURE 5-6

SOIL LOG

SAMPLE

Date: 6-17-11

0

5

10

15

20

25

30

Elevation:

DEPTH

1332 ft Backhoe

W side W infiltration area grass and weeds

Excavator:

TEST PIT LOGS

S11187 LIND WWTP.GPJ BUDINGER.GDT 7/29/11

(27)

6-17-11

0

5

10

15

20

25

30

D.Lehn

FIGURE 5-7

SOIL LOG

Elevation:

TEST PIT 203

2x6 ft.

Location:

Surface:

Bittick

Equipment:

D.Lehn

TEST PIT LOGS

Date:

Size of hole:

Logged by:

FIGURE 5-7

SOIL LOG

SAMPLE

Date: 6-17-11

0

5

10

15

20

25

30

Elevation:

DEPTH

1334 ft Backhoe

S side W infiltration area grass and weeds Excavator:

TEST PIT LOGS

RD TEST PIT S11187 LIND WWTP.GPJ BUDINGER.GDT 7/29/11

(28)

6-17-11

0

5

10

15

20

25

30

D.Lehn

FIGURE 5-8

SOIL LOG

Elevation:

TEST PIT 204

2x6 ft.

Location:

Surface:

Bittick

Equipment:

D.Lehn

TEST PIT LOGS

Date:

Size of hole:

Logged by:

FIGURE 5-8

SOIL LOG

SAMPLE

Date: 6-17-11

0

5

10

15

20

25

30

Elevation:

DEPTH

1334 ft Backhoe

SW corner W infiltration area grass and weeds

Excavator:

TEST PIT LOGS

S11187 LIND WWTP.GPJ BUDINGER.GDT 7/29/11

(29)

loose

moist, brown, loose

slightly moist, tan

medium dense

TOPSOIL

SILT, trace Sand (fine)

SILT, trace sand & gravel (subangular to subrounded)

End of Boring @ 7.4 ft

7-22-11

SOIL LOG

Elevation:

Location:

Logged by:

TEST BORING 301

Budinger & Assoc., Inc.

Hand Auger

N side of W half of W infiltration area grass and weeds

10 20 30 40 50 60 70 80 90

Size of hole:

SAMPLES

DESCRIPTION

Date of Boring:

Surface:

D.Lehn 6 inch

DEPTH

LL

Type of Drill:

TEST RESULTS

Driller:

0

5

10

15

20

25

30

1336 ft

OUT WELL WITH TESTS S11187 LIND WWTP.GPJ BUDINGER.GDT 8/1/11