Concho_WTP_Amendment_001_(Final).pdf

1) What is the absolute longest time the water treatment system can be down?

A – The water treatment plant can be down for 24 hours.

2) Do contractors need to replace or repair existing broken pumps in the pond?

A – Yes, the pump must be replaced.

3) Frame detail on the door/wall detail needs to be provided for the overhead door that will be removed for the lab expansion.

A – The garage door and guide rails shall be removed. The upright framing shall stay in place and any additional framing required is to match existing building framing.

4) Depth of manhole? What’s the depth of the manhole we are tying into?

A – Inverts shown on sheet 5.

5) Sheet rock or paneling in the office area?

A – Sheet rock shall be used for all interior walls in office.

6) Will there need to be a vapor barrier?

A – Yes.

7) What is the moisture content of the existing flooring?

Contractor shall determine moisture content of existing flooring.

8) Does the existing flooring have to have existing epoxy removed, before new is put on and if both will bead blasting be required to prep existing surface?

A – Existing epoxy shall be removed per manufacturer’s instructions prior to application of new epoxy. Contractor shall make every effort to blend the existing floor treatment with the new.

9) Does the residual pond sludge need to go to a landfill or can it be land applied and where?

A - Existing sludge can be land applied on-site to east of the existing lagoons.

10) Are sump pumps currently operational?

A- No.

11) Will new electric wire need to be ran from sump to WTP?

A – No.

12) Does the existing overhead heater need to be replaced?

A - No

13) Traditionally our gauge panels are aluminum not stainless steel can aluminum gauge panel be added to the specification.

A- Aluminum gauge panels will be acceptable.

Questions & Answers

A -

14) What are the motor sizes and VFD requirements for electrical?

A – The motors are each 10 HP.

15) The RFP states that Monroe is specified, but they do not make the packaged treatment system as specified. Please clarify if this is a basis for bid or otherwise.

A – Monroe is not specified in the bid documents.

16) Are the building ventilation fans to be replaced?

A - Yes

17) Sheet 13 does not show domestic water or sewer lines. Are they to be provided?

A – location of water and sewer lines shall be the responsibility of the contractor.

18) The new fencing requires 3 strands of barbed wire. Does the contractor need to provide 3 strands of barbed wire for the existing fencing that will remain?

A - No

19) Please confirm the plant design flow rate and are the 2 trains are for redundancy?

A – The plant is rated at 150 gpm and the second train is for redundancy.

20) The specs only call for GRC conduit. However, on sheet 31 there is a general note that states that we can utilize EMT conduit above 10’ AFF. Please confirm that inside of the building we are to utilize GRC conduit below 10’ AFF, and EMT conduit above 10’ AFF.

A – Yes. EMT will be acceptable above 10’ AFF.

21) Page 8 of specs – what is the dashed line for?

A -- The legend on page 8 states that dashed lines represents existing items that will remain.

22) Can we get copies of the Geotechnical report.

A -- It has been attached.

23) Can you please provide the current raw water chemistry for us to review.

A -- Yes, it has been attached.

24) Section 2.1D 2(a) please confirm anthracite size as the written size seems to be too wide of a range, a more typical size anthracite to “cap” specified silica sand (b) would require spec (a) to be 0.8-1.2mm?

This section needs to be clarified as to who is responsible for supplying the chemical feed equipment. I believe the intent is for the Filter supplier to provide a control panel that interfaces and turns on the chemical feed pumps.

A – The anthracite specifications provided meet the requirements of the system as it’s designed.

25) 46 63 00 Water softener, 2.1A, [Name Brand] has hundreds of softeners working on job sites please add [Name Brand] as an acceptable supplier.

A – In order to be deemed Technically Acceptable prospective contractor must propose a water softener that meets the technical specifications as provided.

26) Section 2.1 D paragraphs 4 and 5 -- Calls for a false bottom plate with media retaining nozzles

While this design does work well, and this had been our standard design for a long time, we have updated our design to minimize potential longer term corrosion issues. A false plate design eliminates the ability to blast and paint below the false floor, and if you do attempt to paint below the UD plate this can be hard to get a uniform and even coating into the far reaches of the tank. Poor coatings have a higher potential for aggressive corrosion down the road. Modification to the paint spec may be needed as most manufacturers (including all named manufacturers) do not paint below the false floor.

Response: Thank you for this feedback.

I would recommend added or changing to the following underdrain design:

Replace 4 and 5 with: The vessel underdrains filter and clarifier sections shall utilize a PVC header lateral design with down turned nonmetallic nozzles. Filter cells require a sub fill with gravels to minimize additional bed height. Clarifier manufacturers who utilize non buoyant clarifier medias shall include subfill gravels to protect the underdrain nozzles from fouling and media migration.

The vessels shall utilize a PVC air wash header lateral grid, placed at the gravel media interface.

Clarifier sections shall include a PVC air wash header lateral placed at the lowest level possible.

This design allows all manufacturers to blast and paint the interior of the vessels completely, then install the underdrain header and laterals. This provides the owners the best long term protection from UD failure and paint failure / corrosion.

Response: Thank you for this feedback however the technical specifications as they currently exist meet the system requirements.

27) During Pre-Bid meeting removal of rust from structural steel was said to be only in a few spots and primed. Will the new primer have to match existing “aged primer” or will all steel have to be primed so it matches?

A -- Touched up where corrosion is evident as close a match as is reasonable.

28) Soils report?

A— Soil Report included in attached GeoTech Report

29) Can contractors reuse existing insulation?

A -- No

30) Wall detail needs to be provided for the overhead door that will be removed for the lab expansion.

A -- The garage door and guide rails shall be removed. The upright framing shall stay in place and any additional framing required is to match existing building framing.

31) Will existing steel members be primed?

A -- Touched up where corrosion is evident as close a match as is reasonable.

32) If the intent is to have two trains IE one off line while the other is operational. Please clarify if the dividing wall has to withstand the differential pressure of having ½ of the basin empty, while the other ½ is full and operating. This is a critical design point, that some manufacturers do not do as normal practice, and should be made aware of prior to bidding this project.

A -- Yes

33) Will Indian Preference factor into contract award?

A – The solicitation includes clause HHSAR 352.226-1, Indian Preference, dated Dec 2015.

34) Can additional site visits be set up for subs?

A -- IHS will allow an additional and informal site visit. If interested in attending this site visit please contact Shaun McGinnis at shaun.mcginnis@ihs.gov and Cc Judy.Perkins@ihs.gov for additional details.

35) The Liquidated Damages section doesn’t indicate a specific dollar amount. At what daily rate will these be assessed if required?

A – The Liquidated Damages Clause 52.211-12 -- LIQUIDATED DAMAGES – CONSTRUCTION (SEPT 2000) states “amount of the actual costs incurred by the government until the work is completed or accepted.”. There is no daily rate associated with this clause.

36) The project period of performance has been listed differently in the Solicitation as 270 calendar days [SF1442, Block 11); 240 calendar days [Section C, IV, Proposed Time Schedule], and 180 calendar days [Section F, Paragraph F.1.(c). Please clarify the required period of performance.

A - The Period of Performance is 270 calendar days.

37) Section L.1.1 states, the Contractor must be determined responsible including having necessary organization, experience, financial resources, schedule, and registrations as required.

Please confirm that all Offerors must positively state their ability to perform within the project period of performance, but are not required to create and submit a proposal schedule in the proposal.

mailto:shaun.mcginnis@ihs.gov mailto:Judy.Perkins@ihs.gov

A. Submission of a performance schedule is not required, however the selected contractor must be able to demonstrate, thru Past Experience Information, they are capable of performing within schedule. Additionally, please note in accordance with FAR 9.104, the Contracting Officer has the discretion to access information from various sources to make a responsibility determination.

38) In the Solicitation paragraph K.5, it notes, “(1) The North American Industry classification System (NAICS) code for this acquisition is 236220,” and “(2) The small business size standard is $20.5M.” We believe this may be a typo, as the current NAICS Code 236220 Small Business size standard is $36.5M. Please confirm the small business threshold for this solicitation is $36.5M.

A. The Small Business Size Standard is $36.5M.

39) Section H.10.4(b) states, The contractor is advised that friable and/or non-friable asbestos containing material has been identified in area(s) where contract work is to be performed.

Please provide the asbestos assessment report identifying ACM locations, asbestos types, and quantity readings.

A. ACM Asbestos Assessments are not applicable to this particular location.

Geotechnical Engineering Report Concho Water Treatment Plant

Black Kettle Boulevard and White Rabbit Road Oklahoma City, Oklahoma

February 9, 2016 Terracon Project No. 03165009

Prepared for:

Cowan Group Engineering, LLC

Oklahoma City, Oklahoma

Prepared by:

Terracon Consultants, Inc.

Oklahoma City, Oklahoma

Concho Water Treatment Plant ■ Concho, Oklahoma February 9, 2016 ■ Terracon Project No. 03165009

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TABLE OF CONTENTS

Page

EXECUTIVE SUMMARY ............................................................................................................. i

1.0 INTRODUCTION

2.0 PROJECT INFORMATION

2.1 Project Description

2.2 Site Location and Description

3.0 SUBSURFACE CONDITIONS

3.1 Typical Profile

3.2 Water Level Observations

4.0 RECOMMENDATIONS FOR DESIGN AND CONSTRUCTION

4.1 Geotechnical Considerations

4.2 Earthwork

4.2.1 Site Preparation

4.2.3 Subgrade Preparation

4.2.4 Fill Materials Requirements

4.2.5 Fill Placement Compaction Requirements

4.2.6 Earthwork Construction Considerations

4.2.7 Grading and Drainage

4.3 Foundations

4.3.1 Shallow Foundation Design Recommendations

4.3.2 Shallow Foundation Construction Considerations

4.4 Floor Slab

4.4.1 Floor Slab Design Recommendations

4.4.2 Floor Slab Construction Considerations

4.5 Seismic Considerations

5.0 GENERAL COMMENTS

APPENDIX A - FIELD EXPLORATION

Exhibit A-1 Site Location Plan Exhibit A-2 Boring Location Diagram Exhibit A-3 Field Exploration Description Exhibits A-4 and A-5 Borings B-1 and B-2

APPENDIX B - LABORATORY TESTING

Exhibit B-1 Laboratory Testing

APPENDIX C - SUPPORTING DOCUMENTS

Exhibit C-1 General Notes Exhibit C-2 Unified Soil Classification

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EXECUTIVE SUMMARY

The following items represent a brief summary of the findings of our subsurface exploration and our geotechnical recommendations for the proposed addition to the existing water treatment plant in Concho, Oklahoma. This summary should be reviewed in conjunction with the complete report.

n The soil profile generally consisted of very loose to medium dense, silty sand underlain by clayey sand or sandy lean clay extending to the boring termination depths.

Groundwater was not encountered in the borings at the time of drilling.

n Soils encountered within the anticipated depth of seasonal moisture change were generally non plastic sands. Construction of floor slabs directly on on-site soils or approved imported soils are considered acceptable for the project. However, due to very loose near surface soils, some difficulty obtaining a passing proofroll is expected and some overexcavation and recompaction or replacement of the on-site soils may be necessary.

n Shallow footings bearing within native soils or tested and approved new fill could be considered to support the building addition; however due to the very loose soils encountered at the site, a low bearing capacity should be used and testing should be performed during construction to verify adequate bearing strata. We anticipate overexcavation and recompaction or replacement may be required beneath the footings in areas where unsuitable soils are encountered.

Close monitoring of the construction operations discussed herein will be critical in achieving effective subgrade support. We believe the project would benefit by retaining Terracon to provide observation/testing during this portion of the work.

This summary should be used in conjunction with the entire report for design purposes. It should be recognized that details were not included or fully developed in this section, and the report must be read in its entirety for a comprehensive understanding of the items contained herein. The section titled GENERAL COMMENTS should be read for an understanding of the report limitations.

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GEOTECHNICAL ENGINEERING REPORT

CONCHO WATER TREATMENT PLANT

BLACK KETTLE BOULEVARD AND WHITE RABBIT ROAD

CONCHO, OKLAHOMA

Terracon Project No. 03165009 February 9, 2016

1.0 INTRODUCTION

Terracon Consultants, Inc. (Terracon) has completed a subsurface exploration for the proposed addition to the building at the existing water treatment plant in Concho, Oklahoma. Two (2) borings were performed at the site to depths of approximately 15 to 20 feet below the existing ground surface. Boring Logs and a Boring Location Plan are included in Appendix A. This report describes the subsurface conditions encountered at the boring locations, presents the test data, and provides geotechnical engineering recommendations regarding the following items:

n subsurface soil conditions n groundwater conditions n earthwork n foundation design and construction n floor slab design and construction n seismic considerations

2.0 PROJECT INFORMATION

2.1 Project Description

Item Description

Site layout See Appendix A, Exhibits A-1 and A-2.

Structure Slab-on-grade, building addition with an area of approximately 800 square feet.

Maximum loads Columns: 35 to 75 kips (assumed) Walls: 2 to 4 klf (assumed) Slab: 150 psf (assumed)

Grading

Grade changes for the proposed site were not provided to us at the time of this report; however, based on the boring elevations, and the existing topography we anticipate minimal cut and/or fill will be necessary for this site.

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2.2 Site Location and Description

Item Description

Site Layout See Exhibits A-1 and A-2, Site Location Plan and Boring Location Plan in Appendix A.

Location At the existing Concho water treatment plant, located northwest of the Black Kettle Boulevard and White Rabbit Road intersection in Concho, Oklahoma

Existing topography Based on the boring elevations and the existing topography the site is relatively flat.

3.0 SUBSURFACE CONDITIONS

3.1 Typical Profile

Subsurface conditions at each boring location are described on the individual boring logs in Appendix A. The stratification boundaries shown on the boring logs represent the approximate depths where changes in material types occur. In-situ, transitions between material types can be more gradual. Based on the results of the borings, subsurface conditions on the project site can be generalized as follows:

Description Approximate Depth to Bottom of Stratum Material Encountered Consistency/Density

Stratum 1 13 to 13.5 feet Silty sand Very loose to medium dense

Stratum 2A Below boring B-1 termination depth of 15 feet

Clayey sand Medium dense

Stratum 2B Below boring B-2 termination depth of 20 feet

Sandy lean clay Medium stiff to stiff

3.2 Water Level Observations

The borings were observed during and after the completion of drilling for the presence and level of groundwater. As reported in the lower left corner of the boring logs, groundwater was not encountered in the borings at these times.

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To obtain more accurate groundwater level information, longer observations in a monitoring well or piezometer that is sealed from the influence of surface water would be needed. Fluctuations in groundwater levels can occur due to seasonal variations in the amount of rainfall, runoff, altered natural drainage paths, and other factors not evident at the time the borings were advanced. Consequently, the designer and contractor should be aware of this possibility while designing and constructing the building addition.

4.0 RECOMMENDATIONS FOR DESIGN AND CONSTRUCTION

4.1 Geotechnical Considerations

The soils within the anticipated depth of seasonal moisture change have little shrink/swell potential and appear suitable for supporting the on-grade floor slabs. This assumes that proofrolling and moisture/density control will be incorporated into subgrade preparation and fill placement procedures. Due to the very loose soils encountered at the site, we expect difficulty obtaining a successful proofroll and some overexcavation and recompaction or replacement may be necessary.

Based on the subsurface conditions encountered and the expected structural loads, shallow footings could be used to support the proposed building addition. However, due to the presence of very loose soils encountered in boring B-2, we recommend the footings be designed with a relatively low bearing pressure and close observation and testing be performed during construction to evaluate that footings do not bear in unsuitable soils. We anticipate overexcavation and recompaction or replacement may be required beneath the footings in areas where unsuitable soils are encountered.

Our recommendations for earthwork, design and construction of foundations, subgrade preparation for floor slabs for the project are presented in the following sections.

4.2 Earthwork

The following presents recommendations for site preparation, subgrade preparation, and placement and compaction of engineered fill on the project. The recommendations presented for design and construction of earth supported elements including the building foundation and floor slab are contingent upon following the recommendations outlined in this section. Grading for the structure should incorporate the limits of the proposed structure plus a minimum pad blow-up of five feet beyond proposed perimeter building walls and any exterior columns.

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Earthwork on the project should be observed and evaluated by Terracon. The evaluation of earthwork should include observation and testing of engineered fill, subgrade preparation, foundation bearing materials, and other geotechnical conditions exposed during the construction of the project.

4.2.1 Site Preparation

Site preparation for the proposed project should include removing vegetation, topsoil, and any other unsuitable surface materials from the areas of new construction. Actual removal depths should be determined at the time of construction by a representative of the geotechnical engineer.

Weather conditions will influence site preparation procedures. If soil moisture contents are high, which could be the case if construction begins following a wet period, drying of exposed soils may be required to develop a stable base on which to place fill. Scarifying and aerating the soil may be sufficient to reduce the moisture content during warm, dry weather, but this will be less effective during periods of cool or wet weather. Removing and replacing or chemically treating wet soils should be expected if site preparation is conducted during cool and/or wet conditions.

4.2.2 Excavations

Temporary excavations may be required during grading operations. The grading contractor, by his contract, is usually responsible for designing and constructing stable, temporary excavations and should shore, slope, or bench the sides of the excavations, as required to maintain stability of both the excavation sides and bottom. All excavations should meet all OSHA and other applicable safety regulations. Grading should develop positive drainage away from open excavations.

4.2.3 Subgrade Preparation

The soils encountered within the anticipated depth of seasonal moisture change were generally non-plastic sands. These soils are not expected to exhibit significant volume changes with variations in the subgrade moisture content. Therefore, the near surface soils are expected to provide adequate support for the on-grade floor slab, provided the procedures outlined below for developing a moisture conditioned, compacted and approved pad are followed.

After site stripping and performing any required undercut, but before placing any fill, we recommend the building addition area be proofrolled with a loaded, tandem-axle dump truck weighing at least 25 tons (under the observation of Terracon personnel) to locate any soft or unstable zones. The proofrolling should involve overlapping passes in mutually perpendicular directions. Where rutting or pumping is observed during proofrolling, the unstable soils should be overexcavated and recompacted or replaced with an approved low volume change soil as described in following sections if it cannot be effectively compacted in-place.

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Very loose subsurface soils were encountered at the site to a depth of about 3 feet in boring B-

2. Therefore, we anticipate unstable areas will be encountered during proofrolling that may require removal and recompaction or replacement. The amount of unstable soil cannot be determined at this time.

After a successful proofroll, the soils should be adjusted to a workable moisture content that is within 2 percent of optimum value, as determined by test method ASTM D-698 (standard Proctor), prior to being compacted to at least 95 percent of its maximum dry density.

4.2.4 Fill Material Requirements

All fill required to develop the design subgrade elevation should be an approved material that is free of organic matter and debris as outlined in the following table.

Fill Type 1 Acceptable Location for Placement

Imported Low Volume Change Cohesive Materials (LL<40, 5<PI<15)

All locations and elevations

Low Volume Change Cohesionless Materials or On-Site Soils (>15% Pass #200)2 All locations and elevations

Aggregate Base Materials3 Below building slab

1. Prior to any filling operations, samples of the proposed borrow and on-site materials should be obtained for laboratory Atterberg Limits and moisture-density testing. The tests will provide a basis for acceptance of the material and evaluation of fill compaction by in-place density testing.

A qualified soil technician should perform sufficient in-place density tests during the filling operations to evaluate that proper levels of compaction, including dry unit weight and moisture content, are being attained.

2. On-site soils appear suitable for use as low volume change soil. However, this should be verified during construction by further testing.

3. ODOT Type A Aggregate Base, Section 703.01 or approved equivalent.

Engineered fill should be placed and compacted in horizontal lifts, using equipment and procedures that will produce recommended moisture contents and densities throughout the lift.

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4.2.5 Fill Placement Compaction Requirements

The recommended compaction and moisture content criteria for engineered fill materials are as follows:

Item Description

Fill Lift Thickness n 9 inches or less in loose thickness when heavy, self-propelled compaction equipment is used.

n 4 to 6 inches in loose thickness when hand-guided equipment (i.e., a jumping jack or plate compactor) is used.

Minimum Compaction Requirement1 n At least 95% of the material’s standard Proctor maximum dry density (ASTM D 698). This level of compaction should extend beyond the edges of footings at least 8 inches for every foot of fill placed below the foundation base elevation.

Moisture Content n Workable moisture content within 2 percent of its optimum value as determined by the standard Proctor test method, ASTM D-698 at the time of placement and compaction.

n Aggregate base materials: Workable moisture content.

1. We recommend that each lift of fill be tested by Terracon for moisture content and compaction prior to the placement of additional fill or concrete. If the results of the in-place density tests indicate the specified moisture or compaction limits have not been met, the area represented by the test should be reworked and retested as required until the specified moisture and compaction requirements are achieved.

4.2.6 Earthwork Construction Considerations

Terracon should be retained during the construction phase of the project to observe earthwork and to perform necessary tests and observations during subgrade preparation, proofrolling, placement and compaction of controlled compacted fills, backfilling of excavations, and just prior to construction of the building addition floor slab.

Care should be taken to avoid disturbing prepared subgrades. Unstable subgrade conditions could develop during general construction operations, particularly if the soils are wetted and/or subjected to repetitive construction traffic. New fill compacted several percentage points above optimum moisture content or that accumulates water during construction can also become disturbed under construction equipment. Construction traffic over the completed subgrade should be avoided to the extent practical. If the subgrade becomes saturated, desiccated or disturbed, the affected materials should either be scarified and compacted or be removed and replaced. Subgrades should be observed and tested by Terracon prior to construction of slabs.

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As a minimum, excavations should be performed in accordance with OSHA 29 CFR, Part 1926, Subpart P, “Excavations” and its appendices, and in accordance with any applicable local, state, and federal safety regulations. The contractor should be aware that slope height, slope inclination, and excavation depth should in no instance exceed those specified by these safety regulations. Flatter slopes than those dictated by these regulations may be required depending upon the soil conditions encountered and other external factors. These regulations are strictly enforced and if they are not followed, the owner, contractor, and/or earthwork and utility subcontractor could be liable and subject to substantial penalties.

4.2.7 Grading and Drainage

Effective drainage should be provided during construction and maintained throughout the life of the project. Infiltration of water into utility trenches or foundation excavations should be prevented during construction. Planters and other surface features which could retain water in areas adjacent to the building should be sealed or eliminated. In areas where sidewalks or paving do not immediately adjoin the structure, we recommend that protective slopes be provided with a minimum grade of approximately five percent for at least 10 feet from perimeter walls. Backfill against exterior walls and in utility and sprinkler line trenches should be well compacted and free of all construction debris to reduce the possibility of moisture infiltration.

Downspouts, roof drains or scuppers should discharge into splash blocks or extensions when the ground surface beneath such features is not protected by exterior slabs or paving. Sprinkler systems should not be installed within five feet of foundation walls. Landscaped irrigation adjacent to the foundation systems should be minimized or eliminated.

4.3 Foundations

4.3.1 Shallow Foundation Design Recommendations

Based on the subsurface conditions encountered in the borings, shallow foundations can be used to support the proposed building addition. Foundation design recommendations for the proposed structure and related structural elements are presented in the following paragraphs.

Design recommendations for shallow foundations for the proposed structure are presented in the following paragraphs.

Description Value

Foundation Type Shallow footings

Bearing Material Native soils or approved new fill

Maximum Net Allowable Bearing Pressure1,2 1,000 psf

Minimum Embedment Depth Below Finished Grade 24 inches

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Description Value

Minimum Width Isolated: 30 inches Continuous: 16 inches

Estimated Total Settlement 1 inch

Estimated Differential Settlement 1/2 of total settlement

Allowable Passive Pressure3 150 pcf (equivalent fluid pressure)

Coefficient of Sliding Friction4 0.2

1. The recommended net allowable bearing pressure is the pressure at the base of the foundation in excess of the adjacent overburden pressure. Assumes any unsuitable materials, if encountered, will be undercut and replaced with engineered fill. The allowable bearing pressure has a safety factor of approximately 3.

2. Due to the presence of very loose soils at the site, Terracon personnel should be retained to observe and evaluate that footing excavations terminate in soils suitable for the actual design bearing pressure. This should include performing shallow depth hand augers, T-probes, calibrated penetrometer tests and dynamic cone penetrometer (DCP) tests in the footing excavations. When DCP tests are used to evaluate the suitability of the bearing soils, they should be performed at the base of the footing excavation and at every 12 inches to a depth equal to the width of column footings or two times the width of continuous wall footings.

However, in no case should the suitability of the bearing soils be evaluated to a depth that is less than 3 feet below the base of footings. If unsuitable soil is present, the excavation should be extended until suitable material is encountered. Unsuitable soil removal should also extend at least 8 inches beyond the foundation edge for each 12-inch thickness of unsuitable soil being removed. The material removed should be replaced with lean concrete or an approved low volume change soil that is compacted as described in the “Earthwork” section of this report.

3. With an applied safety factor of 2. This value also assumes that the foundations are poured directly against undisturbed native materials or that backfill placed around formed foundations are compacted to at least 95 percent of the maximum dry density as determined according to ASTM D-698, the standard Proctor procedure. Unless pavements or on-grade slabs are provided up to and above the footings, the allowable passive pressure should be disregarded to a depth of 2.5 feet below the final grade.

4. With an applied safety factor of 2.

4.3.2 Shallow Foundation Construction Considerations

Provisions should be made during construction to prevent undermining or disturbing the soils supporting the existing building foundations. If new foundations are constructed adjacent to the existing foundations, there is a risk that the bearing material could become undermined and/or overstressed due to overlapping stresses. Maintaining a sufficient clear distance between new and existing foundations will reduce the potential for increased bearing stresses and additional foundation settlement. Connections between the existing building and the new addition should allow for some differential movement.

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Footings, foundations, and masonry walls should be reinforced as necessary to reduce the potential for distress caused by differential foundation movement. The use of joints at openings or other discontinuities in masonry walls is recommended.

Care should be taken to prevent wetting or drying of the bearing materials during construction.

Sloping or temporary shoring of the sides of excavation may be required to prevent caving of the sands. Any extremely wet or dry material, or any loose or disturbed material in the bottom of the foundation excavations, should be removed prior to placing concrete. The potential for wetting or drying of the bearing materials can be reduced by placing concrete as soon as possible after completing the foundation excavations and evaluating the bearing strata.

Foundation excavations should be observed by the geotechnical engineer. If the bearing materials encountered differ significantly from those presented in this report, supplemental recommendations will be required.

4.4 Floor Slab

4.4.1 Floor Slab Design Recommendations

Description Value

Interior floor system Slab-on-grade concrete

Floor slab support1,2 On-site materials prepared in accordance with the Earthwork section of this report.

1. Floor slabs should be structurally independent of building foundations and walls to reduce the possibility of floor slab cracking caused by differential movements between the slab and foundations.

2. We recommend floor slabs subjected to heavy concentrated loads be supported on a 6-inch thickness of ODOT Type “A” crushed aggregate meeting the requirements of Section 703.01.

The crushed aggregate should be compacted to at least 95 percent of its maximum dry density, as determined by the standard Proctor test method (ASTM D-698).

In areas of exposed concrete, control joints should be saw cut into the slab after concrete placement in accordance with ACI Design Manual, Section 302.1R-37 8.3.12 (tooled control joints are not recommended). Additionally, dowels should be placed at the location of proposed construction joints. To control the width of cracking (should it occur) continuous slab reinforcement should be considered in exposed concrete slabs.

Positive separations and/or isolation joints should be provided between slabs and all foundations, columns or utility lines to allow independent movement. Interior trench backfill placed beneath slabs should be compacted in accordance with recommendations outlined in the Earthwork section of this report. Other design and construction considerations, as outlined in the ACI Design Manual, Section 302.1R are recommended.

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The use of a vapor retarder or barrier should be considered beneath concrete slabs on grade that will be covered with wood, tile, carpet or other moisture sensitive or impervious coverings, or when the slab will support equipment sensitive to moisture. When conditions warrant the use of a vapor retarder, the slab designer and slab contractor should refer to ACI 302 and ACI 360 for procedures and cautions regarding the use and placement of a vapor retarder/barrier.

4.4.2 Floor Slab Construction Considerations

On most project sites, the site grading is generally accomplished early in the construction phase.

As construction proceeds, the subgrade may be disturbed by utility excavations, construction traffic, desiccation, rainfall, etc. As a result, corrective action may be required prior to placement of the concrete.

Terracon should review the condition of the floor slab subgrade immediately prior to the construction of the slabs. Particular attention should be paid to high traffic areas that were rutted and disturbed earlier and to areas where backfilled trenches are located. Areas where unsuitable conditions are located should be repaired by scarification/compaction or by removing the affected material and replacing it with engineered fill.

4.5 Seismic Considerations

Description Value 2009 International Building Code Site Classification (IBC) D

Note: In general accordance with the 2009 International Building Code, Table 1613.5.2. The 2009 International Building Code (IBC) uses a site soil profile determination extending to a depth of 100 feet for seismic site classification. The current scope does not include the required 100 foot soil profile determination. Borings extended to a maximum depth of 20 feet. This seismic site class definition considers that sand or clay continues below the maximum depth of the subsurface exploration. Additional exploration to deeper depths would be required to confirm the conditions below the current depth of exploration.

5.0 GENERAL COMMENTS

Terracon should be retained to review the final design plans and specifications so comments can be made regarding interpretation and implementation of our geotechnical recommendations in the design and specifications. Terracon also should be retained to provide observation and testing services during grading, excavation, foundation construction and other earth-related construction phases of the project.

February 9, 2016 ■ Terracon Project No. 03165009

Reliable ■ Responsive ■ Resourceful 11

The analysis and recommendations presented in this report are based upon the data obtained from the borings performed at the indicated locations and from other information discussed in this report. This report does not reflect variations that may occur between borings, across the site, or due to the modifying effects of construction or weather. The nature and extent of such variations may not become evident until during or after construction. If variations appear, we should be immediately notified so that further evaluation and supplemental recommendations can be provided.

The scope of geotechnical services for this project does not include either specifically or by implication any environmental or biological (e.g., mold, fungi, bacteria) assessment of the site or identification or prevention of pollutants, hazardous materials or conditions.

This report has been prepared for the exclusive use of our client for specific application to the project discussed and has been prepared in accordance with generally accepted geotechnical engineering practices. No warranties, either expressed or implied, are intended or made. Site safety, excavation support, and dewatering requirements are the responsibility of others. In the event that changes in the nature, design, or location of the project as outlined in this report are planned, the conclusions and recommendations contained in this report shall not be considered valid unless Terracon reviews the changes and either verifies or modifies the conclusions of this report in writing.

APPENDIX A

FIELD EXPLORATION

February 9, 2016 ■ Terracon Project No. 03165009

Reliable ■ Responsive ■ Resourceful Exhibit A-3

Field Exploration Description

Two (2) test borings were drilled at the site on January 14, 2016. The borings were drilled to depths 15 to 20 feet below the ground surface at the approximate locations shown on the attached Boring Location Plan, Exhibit A-2.

Terracon personnel located the borings in the field by taping distances from the references shown on the attached boring location plan. The surface elevations at the boring locations were determined using differential leveling procedures. An assumed benchmark elevation of 100 feet was used and referenced to the finish floor of the existing building located approximately as shown on the boring location plan. Based on this benchmark, the surface elevations at the boring locations were 100 feet. The elevations on the boring logs have been rounded to the nearest 1/2 foot. The locations and elevations of the borings should be considered accurate only to the degree implied by the methods used to define them.

A truck-mounted rotary drill rig equipped with continuous flight augers was used to advance the boreholes. Representative samples were obtained by the split-barrel sampling procedures.

The split-barrel sampling procedure uses a standard 2-inch O.D. split-barrel sampling spoon that is driven into the bottom of the boring with a 140-pound drive hammer falling 30 inches.

The number of blows required to advance the sampling spoon the last 12 inches, or less, of a typical 18-inch sampling interval or portion thereof, is recorded as the standard penetration resistance value, N. The N value is used to estimate the in-situ relative density of cohesionless soils and, to a lesser degree of accuracy, the consistency of cohesive soils and the hardness of sedimentary bedrock. The sampling depths, penetration distances, and the N values are reported on the boring logs. The samples were tagged for identification, sealed to reduce moisture loss and returned to the laboratory for further examination, testing and classification.

An automatic Standard Penetration Test (SPT) drive hammer was used to advance the split-barrel sampler. The automatic drive hammer achieves a greater mechanical efficiency when compared to a conventional safety drive hammer operated with a cathead and rope. We considered this higher efficiency in our interpretation and analysis of the subsurface information provided with this report.

Field logs were prepared as part of the drilling operations. These boring logs included visual classifications of the materials encountered during drilling and the field personnel’s interpretation of the subsurface conditions between samples. The final boring logs included with this report may include modifications based on observations and tests of the samples in the laboratory.

Surface Cover: Vegetation

87+/-

85+/-

5-5-6 N=11

3-2-2 N=4

3-2-2 N=4

3-1-1 N=2

3-5-6 N=11

13.0

15.0

SILTY SAND (SM), trace clay, brown, medium dense

-yellowish-brown, loose below 3'

-very loose below 8.5'

CLAYEY SAND (SC), dark brown, medium dense

Boring Terminated at 15 Feet

Hammer Type: AutomaticStratification lines are approximate. In-situ, the transition may be gradual.

G R

A P

H

IC

L O

G

T H

IS

B

O R

IN

G

L O

G

IS

N O

T V

A

LI

D

IF

S E

P A

R A

T E

D F

R O

M O

R

IG

IN

A

L R

E P

O R

T

G E

O S

M A

R T

L O

G -N

O W

E

LL

C

O N

C H

O W

A T

E R

T R

E A

T M

E N

T P

LA

N

T .G

P J

Black Kettle Boulevard & White Rabbit Road Concho, Oklahoma

SITE:

Advancement Method:

Power Auger

Abandonment Method:

Boring backfilled with soil cuttings upon completion.

4701 North Stiles Avenue Oklahoma City, Oklahoma

Notes:

Project No.: 03165009

Drill Rig: 387

Boring Started: 1/14/2016

BORING LOG NO. B-1

Cowan Group Engineering, LLCCLIENT:

Oklahoma City, Oklahoma

Driller: C. Lindrud

Boring Completed: 1/14/2016

Exhibit: A-4

See Exhibit A-3 for description of field procedures.

See Appendix B for description of laboratory procedures and additional data (if any).

See Appendix C for explanation of symbols and abbreviations.

PROJECT: Concho Water Treatment Plant

LA

B

O R

A T

O R

Y T

O R

V A

N E

/H P ps f)

U N

C O

N F

IN

E

D C

O M

P R

E S

S

IV

E S

T R

E N

G T

H ps f)

P E

R C

E N

T F

IN

E

S

W A

T E

R C

O N

T E

N T

D R

Y U

N

IT

W E

IG

H

T pc f)

ATTERBERG

LIMITS

LL-PL-PI

Approximate Surface Elev: 100.0 (Ft.) +/-

ELEVATION (Ft.)

S A

M P

LE

T

Y P

E

W A

T E

R L

E V

E L

O B

S E

R V

A T

IO

N

S

D E

P T

H

F t.)

R E

C O

V E

R Y

In

F

IE

LD

T

E S

T R

E S

U

LT

S

DEPTH

LOCATION See Exhibit A-2

Latitude: 35.61005° Longitude: -97.9947°

No free water observed

WATER LEVEL OBSERVATIONS

Surface Cover: Vegetation

86.5+/-

80+/-

1-1-1 N=2

1-2-2 N=4

1-1-2 N=3

1-1-1 N=2

3-3-5 N=8

3-3-7 N=10

13.5

20.0

SILTY SAND (SM), brown, very loose

-yellowish-brown below 3.5'

-very loose below 6'

SANDY LEAN CLAY (CL), reddish-brown, medium stiff

-grayish-brown, stiff below 18.5'

Boring Terminated at 20 Feet

Hammer Type: AutomaticStratification lines are approximate. In-situ, the transition may be gradual.

G R

A P

H

IC

L O

G

T H

IS

B

O R

IN

G

L O

G

IS

N O

T V

A

LI

D

IF

S E

P A

R A

T E

D F

R O

M O

R

IG

IN

A

L R

E P

O R

T

G E

O S

M A

R T

L O

G -N

O W

E

LL

C

O N

C H

O W

A T

E R

T R

E A

T M

E N

T P

LA

N

T .G

P J

Black Kettle Boulevard & White Rabbit Road Concho, Oklahoma

SITE:

Advancement Method:

Power Auger

Abandonment Method:

Boring backfilled with soil cuttings upon completion.

4701 North Stiles Avenue Oklahoma City, Oklahoma

Notes:

Project No.: 03165009

Drill Rig: 387

Boring Started: 1/14/2016

BORING LOG NO. B-2

Cowan Group Engineering, LLCCLIENT:

Oklahoma City, Oklahoma

Driller: C. Lindrud

Boring Completed: 1/14/2016

Exhibit: A-5

See Exhibit A-3 for description of field procedures.

See Appendix B for description of laboratory procedures and additional data (if any).

See Appendix C for explanation of symbols and abbreviations.

PROJECT: Concho Water Treatment Plant

LA

B

O R

A T

O R

Y T

O R

V A

N E

/H P ps f)

U N

C O

N F

IN

E

D C

O M

P R

E S

S

IV

E S

T R

E N

G T

H ps f)

P E

R C

E N

T F

IN

E

S

W A

T E

R C

O N

T E

N T

D R

Y U

N

IT

W E

IG

H

T pc f)

ATTERBERG

LIMITS

LL-PL-PI

Approximate Surface Elev: 100.0 (Ft.) +/-

ELEVATION (Ft.)

S A

M P

LE

T

Y P

E

W A

T E

R L

E V

E L

O B

S E

R V

A T

IO

N

S

D E

P T

H

F t.)

R E

C O

V E

R Y

In

F

IE

LD

T

E S

T R

E S

U

LT

S

DEPTH

LOCATION See Exhibit A-2

Latitude: 35.61005° Longitude: -97.9949°

No free water observed

WATER LEVEL OBSERVATIONS

APPENDIX B

LABORATORY TESTING

February 9, 2016 ■ Terracon Project No. 03165009

Reliable ■ Responsive ■ Resourceful Exhibit B-1

Laboratory Testing

Samples retrieved during the field exploration were taken to the laboratory for further observation by the project geotechnical engineer and were classified in accordance with the Unified Soil Classification System (USCS) described in Appendix C. At that time, the field descriptions were confirmed or modified as necessary and an applicable laboratory testing program was formulated to determine engineering properties of the subsurface materials.

Laboratory tests were conducted on selected soil samples and the test results are presented on the logs in Appendix A. The laboratory test results were used for the geotechnical engineering analyses, and the development of foundation and earthwork recommendations. Laboratory tests were performed in general accordance with the applicable ASTM, local or other accepted standards.

Selected soil samples obtained from the site were tested for the following engineering properties:

n Visual Classification (ASTM D2488) n In-situ Water Content (ASTM D2216) n Percent Passing the #200 Sieve (ASTM D1140)

Procedural standards noted above are for reference to methodology in general. In some cases variations to methods are applied as a result of local practice or professional judgment.

APPENDIX C

SUPPORTING DOCUMENTS

1 - 10 11 - 30

> 30

RELATIVE PROPORTIONS OF FINES

Descriptive Term(s) of other constituents

Percent of Dry Weight

Hand Penetrometer

Torvane

Standard Penetration Test (blows per foot)

Photo-Ionization Detector

Organic Vapor Analyzer

Texas Cone Penetrometer

Trace With Modifier

Water Level After a Specified Period of Time

GRAIN SIZE TERMINOLOGYRELATIVE PROPORTIONS OF SAND AND GRAVEL

Trace With Modifier

Standard Penetration or N-Value

Blows/Ft.

Descriptive Term (Consistency)

Loose

Very Stiff

Standard Penetration or N-Value

Blows/Ft.

Ring Sampler Blows/Ft.

Ring Sampler Blows/Ft.

Medium Dense

Dense

Very Dense

0 - 1 < 3

4 - 9 2 - 4 3 - 4

Medium-Stiff 5 - 9

30 - 50

W A

T E

R L

E V

E L

Auger

Shelby Tube

Grab Sample

F

IE

L D

T E

S T

S

DESCRIPTION OF SYMBOLS AND ABBREVIATIONS

Descriptive Term (Density)

Non-plastic Low Medium High

Boulders Cobbles Gravel Sand Silt or Clay

10 - 18

> 50 15 - 30 19 - 42

> 30 > 42

Water levels indicated on the soil boring logs are the levels measured in the borehole at the times indicated.

Groundwater level variations will occur over time. In low permeability soils, accurate determination of groundwater levels is not possible with short term water level observations.

CONSISTENCY OF FINE-GRAINED SOILS

(50% or more passing the No. 200 sieve.)

Consistency determined by laboratory shear strength testing, field visual-manual procedures or standard penetration resistance

DESCRIPTIVE SOIL CLASSIFICATION

> 8,000

Unless otherwise noted, Latitude and Longitude are approximately determined using a hand-held GPS device. The accuracy of such devices is variable. Surface elevation data annotated with +/- indicates that no actual topographical survey was conducted to confirm the surface elevation. Instead, the surface elevation was approximately determined from topographic maps of the area.

Soil classification is based on the Unified Soil Classification System. Coarse Grained Soils have more than 50% of their dry weight retained on a #200 sieve; their principal descriptors are: boulders, cobbles, gravel or sand. Fine Grained Soils have less than 50% of their dry weight retained on a #200 sieve; they are principally described as clays if they are plastic, and silts if they are slightly plastic or non-plastic. Major constituents may be added as modifiers and minor constituents may be added according to the relative proportions based on grain size. In addition to gradation, coarse-grained soils are defined on the basis of their in-place relative density and fine-grained soils on the basis of their consistency.

Plasticity Index

8 - 15

Split Spoon

Rock Core

PLASTICITY DESCRIPTION

Term

< 15 15 - 29 > 30

Descriptive Term(s) of other constituents

Water Initially Encountered

Water Level After a Specified Period of Time

Major Component of Sample

Percent of Dry Weight

(More than 50% retained on No. 200 sieve.)

Density determined by Standard Penetration Resistance

Includes gravels, sands and silts.

Hard

Very Loose 0 - 3 0 - 6 Very Soft

7 - 18 Soft

10 - 29 19 - 58

59 - 98 Stiff less than 500

500 to 1,000

1,000 to 2,000

2,000 to 4,000

4,000 to 8,000> 99

LOCATION AND ELEVATION NOTES

S A

M P

L

IN

G

< 5 5 - 12 > 12

No Recovery

RELATIVE DENSITY OF COARSE-GRAINED SOILS

Particle Size

Over 12 in. (300 mm) 12 in. to 3 in. (300mm to 75mm) 3 in. to #4 sieve (75mm to 4.75 mm) #4 to #200 sieve (4.75mm to 0.075mm Passing #200 sieve (0.075mm)

S T

R E

N G

T H

T E

R M

S Unconfined Compressive Strength, Qu, psf

4 - 8

GENERAL NOTES

Texas Cone

(HP)

(T)

(b/f)

(PID)

(OVA)

(TCP)

Pressure Meter

Exhibit C-1

UNIFIED SOIL CLASSIFICATION SYSTEM

Criteria for Assigning Group Symbols and Group Names Using Laboratory Tests A Soil…