Appendix_6-Geotech_Report.pdf

5808‐A Breckenridge Parkway, Tampa, Florida 33610 Phone (813) 623‐3399, Fax (813) 623‐6636 www.mc2engineers.com

MC Squared, Inc.

Geotechnical Engineering Services Report

Pinellas County Waste to Energy Facility Industrial Water Treatment Plant Pond Intake Improvements and Slope Repair

Pinellas County, Florida

Prepared for: Hazen and Sawyer 7334 Delaney Court Sarasota, Florida 34240

Prepared by: MC Squared, Inc.

5808‐A Breckenridge Parkway Tampa, Florida 33610

MC2 Project No. T041905.096 November 11, 2019 (Revised January 8, 2020) i

TABLE OF CONTENTS

1 PROJECT INFORMATION

1.1 PROJECT AUTHORIZATION

1.2 PROJECT DESCRIPTION

1.3 SCOPE OF SERVICES

2 SITE CONDITIONS

2.1 SITE FEATURES

2.2 HILLSBOROUGH COUNTY SOIL SURVEY

2.3 USGS TOPOGRAPHIC SURVEY

3 FIELD EXPLORATION PROGRAM

3.1 GENERAL

3.2 GEOPHYSICAL SURVEY

3.3 STANDARD PENETRATION TEST BORINGS

3.4 TEST PIT EXCAVATIONS

4 LABORATORY TESTING

4.1 SOIL CLASSIFICATION TESTING

5 SUBSURFACE CONDITIONS

5.1 SUBSURFACE SOIL CONDITIONS

6 EVALUATIONS AND CONCLUSIONS

7 RECOMMENDATIONS

7.1 SLOPE REPAIR

7.2 FOUNDATION CONSTRUCTION

7.3 FRICTION COEFFICIENTS

8 REPORT LIMITATIONS

APPENDIX

Summary of Soil Parameters – Table No. 4 Project Location Map – Sheet 1 Boring Location Map – Sheet 2 USDA Soil Survey and USGS Topographic Map – Sheet 3 Subsurface Boring Profile – Sheet 4 Legend – Sheet 5 Individual Soil Profiles (8 Sheets) GeoView Final Report of Geophysical Survey Test Procedures

1 PROJECT INFORMATION

1.1 Project Authorization

Authorization to proceed with this project was issued through a Subcontract Agreement for Professional Services, Amendment No. 1 signed by Andre Dieffenthaller, Vice President of Hazen and Sawyer, on September 6, 2019, in accordance with our proposal dated April 04, 2019, and subsequently revised on October 8, 2019.

1.2 Project Description

The proposed project site is located at 3095 114th Avenue North in St. Petersburg, Pinellas County, Florida. Project information has been provided by Mr. Andrew Coleman, PE of Hazen and Sawyer through e‐mailed and phone communications, including photographs showing the erosion that the pond slope has experienced. Based on our understanding, the project entails repair of the pond slope, as well as additional design considerations for the proposed pond intake pad and winch pads. Additionally, it is reported that in‐situ rip rap may be buried at the pump and winch pad locations. Figure 1 shows the latest site plan provided by Hazen and Sawyer.

Figure 1: Provided Site Plan

Previously, MC2 performed geotechnical explorations for this project, and the results documented under MC2 Project Nos. T071613.147 and T021814.032. These previous undertakings explored the possibility of constructing a foundation for the intake pipe within the pond, as well as provided our evaluation and recommendations for the design and construction of the proposed winch pads and pond intake pump slab on land, prior to the pond embankment failure.

If any of this project information is incorrect or has changed, please inform MC2 so that we might amend, if appropriate, the recommendations presented in this report.

1.3 Scope of Services

Our scope of services consisted of the following:

1. Reviewed our previous geotechnical studies performed at the site as well as historical documentation and site plans provided to us by Hazen and Sawyer.

2. Conducted a visual reconnaissance of the pond area to identify areas with possible access issues for drilling and excavation equipment and personnel, as well as stake the field activity locations.

3. Prepared a notification letter for the proposed exploratory soil test borings for the Florida Department of Environmental Protection (FDEP).

4. Performed an expanded geophysical survey of the areas around the existing pump facility and the south and north berms of the pond at the winch pad locations. The geophysical survey utilized ground penetrating radar (GPR), time domain electromagnetics (TDEM) and conventional electromagnetic (EM) pipe and cable locators to determine the location of underground utilities and other buried obstructions present within the study areas.

5. Performed two (2) SPT borings (SPT‐03 and SPT‐04), each to a depth of 20‐ft. below the ground surface (bgs) at the proposed locations of the pump and southern winch pads, as approved by Hazen and Sawyer. Continuous soil sampling was performed in each of the test borings to gather complete subsurface information over the 20‐ft. depth. In addition, casing was utilized for the full depth of both SPT borings to prevent the intrusion of water from the pond into the boreholes.

6. Measured and recorded the depth to groundwater, when encountered, and prior to the introduction of drill slurry.

7. Four (4) test pit excavations were performed at the proposed pump and winch pads to evaluate the nature of reported, existing rip rap material. Subsequent hand‐auger (HA) borings were performed, as required, through the base of the excavations to further explore the subsurface soil conditions.

8. Backfilled SPT boreholes by means of tremie grouting from the bottom to the top of the holes. Grout return to the surface was verified in both boreholes. All soil cuttings/spoils were properly disposed of as directed by onsite personnel.

9. Restored the area of the test pit excavations by backfilling with previously excavated soil and mechanically compacted with the excavator bucket.

10. Visually examined all recovered soil samples in our Tampa, Florida laboratory and performed laboratory tests on selected, representative samples to characterize the subsurface soil profiles. Description of the soil samples were in accordance with the

Unified Soil Classification System (USCS), as appropriate. The laboratory classification testing included percent passing the U.S. No. 200 sieve, Atterberg Limits tests and natural moisture content determination.

The field and laboratory test data were used to develop the following:

1. Critical design and/or construction considerations for the intake improvements and slope stabilization.

2. Review and update of our previous recommendations, as necessary, for shallow foundation design and construction considerations for the pump and winch pads.

The scope of our services did not include an environmental assessment for determining the presence or absence of wetlands or hazardous or toxic materials in the soil, bedrock, groundwater, or air, on or below or around this site. Any statements in this report or on the boring logs regarding odors, colors, unusual or suspicious items or conditions are strictly for the information of our client. In addition, our scope of services did not include an evaluation of sinkholes or sinkhole activity.

2 SITE CONDITIONS

2.1 Site Features

The site is generally clear of obstructions. The distance from the bottom of the pond to the crest of the pond berm where the borings were performed is about 19‐ft. according to provided elevations. The water elevation appeared to be approximately 8 to 10‐ft. lower than the locations of our SPT borings and test pits.

Figure 2: Southeast Corner of Pond viewing North (photographed October 11, 2019)

2.2 Pinellas County Soil Survey

The U.S. Department of Agriculture (USDA) – Soil Conservation Service (SCS) Soil Survey of Pinellas County, Florida was reviewed for general information on the shallow soils in the site vicinity. The survey area data is Version 16, September 17, 2019, with aerial images taken from December 17, 2013 to February 28, 2014. A portion of the USDA Soil Survey Map of the project area is included in the Appendix for information and reference. The USDA Soil Survey outlines approximate areas dominated by a particular shallow soil type. The project site lies within two (2) mapping units: Pits

(24) and Wabasso soils and Urban land (31).

Pits (24) consist of areas that have been excavated for various reasons. Little to no information is provided for this soil survey unit.

Wabasso soils and Urban land (31) has a parent material of sandy and loamy marine deposits and a typical profile of fine sand from zero to 36‐in., sandy clay loam from 36 to 50‐in. and fine sand from 50 to 80‐in. bgs. The material is poorly drained and has a moderately low to moderately high capacity to transmit water. The depth to groundwater table is about 6 to 18‐in. bgs.

The USDA Soil Survey is not necessarily an exact representation of the soils on the site. The mapping is based on interpretation of aerial maps with scattered shallow borings for confirmation. Accordingly, borders between mapping units are approximate and the change may be transitional. Differences may also occur from the typical stratigraphy, and small areas of other similar and dissimilar soils may occur within the soil‐mapping unit and in urban areas where a lot of development has taken place. As such, there may be differences in the mapped description and the boring descriptions obtained for this report. The survey is, however, a good basis for evaluating the shallow soil conditions of the area. A summary of the USDA mapping unit at each boring location is available in the following Table 1.

Table 1: Summary of USDA Soil Survey Information at Boring Locations

Boring IDs USDA Mapping Unit USDA Typical Profile (in) USDA SHWT (in)

SPT‐01 to SPT‐03 TP‐02 to TP‐04

Pits (24) ‐‐ ‐‐

SPT‐04

TP‐01

Wabasso soils and Urban land (31) fine sand: 0 to 36 sandy clay loam: 36 to 50 fine sand: 50 to 80 6 to 18

2.3 USGS Topographic Survey

Based on our review of the USGS topographic quadrangles titled “Safety Harbor Quadrangle”, the existing site where the field work was performed is at an approximate elevation range of zero to 10 feet NGVD 1929 (refer to the USGS Topographic Map in the Appendix). The elevation has not changed drastically since the man‐made pond at the site was constructed.

3 FIELD EXPLORATION PROGRAM

3.1 General

The fieldwork consisted of performing a geophysical survey to identify any potential underground utilities within the testing areas and check for the presence of rip‐rap; four (4) test pit excavations and associated HA borings; and, two (2) SPT borings to explore the subsurface soil and groundwater conditions, as directed by Hazen and Sawyer. Fieldwork began once approval to access the site was received. The geophysical survey was performed on October 10, 2019, followed by the test pit excavations from October 10 through October 11, 2019, and the SPT borings on October 18, 2019. The fieldwork was monitored and observed by MC2 field staff and overseen by one of MC2’s Florida‐licensed, professional geotechnical engineers.

3.2 Geophysical Survey

The geophysical survey was conducted along the northern, eastern and southern berms of the pond where the project improvements are proposed. The survey was conducted using ground penetrating radar (GPR), time domain electromagnetics (TDEM), and conventional electromagnetic (EM) pipe and cable locators to determine the location of underground utilities and other buried obstructions (predominantly, rubble rip‐rap) within the study areas. Utilities were marked on the ground with paint for the Surveyor to document. Additional details regarding this survey can be found in the Geophysical Report in the Appendix of this report.

3.3 Standard Penetration Test Borings

Two (2) SPT borings were completed at the site in general accordance with ASTM D1586 (Standard Test Method for Penetration Test and Split Barrel Sampling of Soils) by a truck‐mounted drill rig with an automatic hammer using a wet‐rotary procedure. Representative soil samples were obtained using the split‐barrel sampling procedure. In this procedure, a 2‐in. outer‐diameter split‐ barrel sampler is driven into the soil by a 140‐lb hammer with a free‐fall of 30‐in. The number of blows required to drive the sampler through a 12‐in. interval, after initial penetration of 6‐in., is termed the Standard Penetration Resistance, or "N‐value”, and is indicated for each sample on the boring log. The N‐value may be taken as an indication of the relative density (cohesionless soils) or consistency (cohesive soils) of soils in‐situ.

It should be noted that steel casing was installed in 5‐ft. sections for the entire depth of the soil test borings. Once the borings were completed, they were immediately backfilled by tremie grouting from the bottom to the top. Grout return to the surface was verified and maintained throughout this process. The steel casing was slowly and incrementally removed while maintaining full grout return to ensure that the boreholes were fully grouted. Soil cuttings/spoils were drummed and properly disposed of onsite, as directed by Pinellas County.

Soil samples recovered during the field exploration program were placed into airtight glass jars properly labeled with the project number, boring number and sample number and returned to our Tampa, FL office to confirm field classification and perform laboratory testing, as required. All soil samples collected will be retained in‐house for 60 days from the date of release of this report and will be subsequently discarded without further notice, unless requested otherwise in writing.

Figure 3: Truck‐mounted drill rig, photographed on October 18, 2019

Groundwater, if encountered, is normally measured during the advancement of our borings and prior to the introduction of bentonite to the drilling fluid. Once bentonite is added, an accurate groundwater level is difficult to measure. Upon completion of our drilling, all test borings were grouted in general accordance with applicable procedures.

During design, the N‐values obtained using an automatic hammer should be corrected for overburden pressure as the actual input driving energy is different between safety and automatic hammers. However, when using FB‐Deep, the N‐Values should not be corrected since the design methodology is based on uncorrected N‐values. Based on the results of an FDOT study, a multiplier of 1.24 shall be applied when correcting N‐values obtained using an automatic hammer on all FDOT projects. The corrected N‐values shall be indicated as NES. The N‐Values obtained in the field are represented on the Boring Profiles while the NES‐Values are presented on the Summary of Soil Parameters – Table 4 in the Appendix of this report.

3.4 Test Pit Excavations

Four (4) test pit excavations were conducted at the southern, northern, and eastern berms of the pond near/at the three (3) proposed winch pads and pump pad location. Each test pit excavation was mechanically dug with an excavator to a minimum depth of 7.5‐ft. bgs and further deepened with a hand‐auger (HA) boring up to 12‐ft. bgs or until the borehole collapsed, whichever occurred first. Representative samples of each soil change were collected and documented. Test pits were backfilled with the excavated soils and mechanically compacted with the excavator bucket. The approximate locations of the test pit excavations are shown on the Boring Location Map and the detailed soil descriptions are presented on the Soil Profiles in the Appendix.

Figure 4: Northern test pit excavation and HA boring at winch pad, photographed on October 10, 2019

4 LABORATORY TESTING

4.1 Soil Classification Testing

A representative set of soil samples was tested in the laboratory to assist in the classification and determination of the physical and engineering characteristics of the soils based on their mechanical and physical behavior. Laboratory testing was accomplished in general accordance with applicable ASTM standards. Laboratory tests completed on soil samples retrieved for this project include:

Eight (8) moisture content determinations (ASTM D4959), Eight (8) percent passing the No. 200 US standard sieve tests (ASTM D1140), One (1) Atterberg limit determination tests (ASTM D431), and

Visual classification in general accordance with USCS procedures (ASTM D2487).

Results for each of the laboratory tests are summarized in Table 2 below and are also presented on the individual Soil Profile logs provided in the Appendix.

Table 2: Summary of Laboratory Testing

Boring No.

(Depth) (ft.)

Moisture Content

Percent Passing No. 200 Sieve (%)

Liquid Limit

Plastic Limit

Plasticity Index

USCS

Classification

SPT‐03 (8‐10) 24.9 22.2 ‐ ‐ ‐ SC

SPT‐03 (18‐20) 32.1 64.5 ‐ ‐ ‐ CL

SPT‐04 (8‐10) 18.3 3.4 ‐ ‐ ‐ SP

SPT‐04 (14‐16) 25.9 25.2 28 18 10 SC

SPT‐04 (16‐18) 28.7 27.4 ‐ ‐ ‐ SC

TP‐2 (4‐6) 15.6 2.0 ‐ ‐ ‐ SP

TP‐3 (8‐9) 16.2 4.7 ‐ ‐ ‐ SP

TP‐4 (9‐11) 17.1 8.1 ‐ ‐ ‐ SP‐SM

5 SUBSURFACE CONDITIONS

5.1 Subsurface Soil Conditions

The following subsurface description is of a generalized nature, provided to highlight the major soil strata encountered. The boring logs/soil profiles included in the Appendix should be reviewed for specific information at individual test locations. The stratifications shown on the boring profiles represent the conditions only at the actual test locations. Variations may occur and should be expected between test locations. The stratifications represent the approximate boundary between and among subsurface materials; however, the transition may be gradual. The soils encountered in the soil borings are generally consistent across the site.

Standard Penetration Test Borings (SPT‐03 and SPT‐04)

The subsurface conditions in the SPT borings consisted of very loose to medium dense, poorly graded fine SAND to fine SAND with silt (SP, SP‐SM) from the surface to 14‐ft. bgs, followed by very loose to loose, clayey fine SAND (SC) to 18‐ft. bgs in SPT‐03 and 20‐ft. bgs in SPT‐4. A thin layer of loose, clayey fine SAND (SC) was penetrated from 6 to 8‐ft. bgs in boring SPT‐03 as well as soft, lean CLAY (CL) from 15 to 20‐ft. bgs. Both borings were terminated at a depth of 20‐ft. bgs.

Test Pit Excavations (TP‐1 through TP‐4)

The soils encountered at the test pit excavations consisted of poorly graded, fine SAND to fine SAND with silt (SP, SP‐SM) throughout the depth of the test pits. Concrete and construction debris were encountered in all test pits at depths ranging from 4 to 6‐ft. bgs and shell fragments were present at depths ranging from 6 to 12‐ft. bgs. No rip rap rubble material was encountered in any of the test pit excavations.

Figure 5: Proposed pump pad test pit excavation debris, photographed on October 10, 2019

6 EVALUATIONS AND CONCLUSIONS

The following evaluations and conclusions have been developed based on the previously described project characteristics, our review of published data, information provided by the project team members and that gathered from all of our subsurface explorations and associated laboratory testing Once final design plans and specifications are available, a general review by MC2 is strongly recommended to check that the evaluations made in preparation of this report are correct and that earthwork and foundation recommendations are properly interpreted and implemented.

1. We compared the USDA soil survey information with the shallow subsurface information collected in our test borings. The soil survey data generally appeared similar to the soil data collected from the borings performed, taking into account site development activities. The USDA Soil survey classifies the majority of the site as Pits (24). However, the berms around the pond are likely man‐made while the USDA Soil Survey provides information on naturally occurring soil and rock information. Our field activities generally encountered poorly‐graded, fine SAND to fine SAND with silt (SP, SP‐SM) with debris within the upper 8‐ft. bgs.

2. Our review of the USGS Topographic Map did not indicate any features that appeared out of the ordinary and does not require further clarification.

3. MC2 and Hazen and Sawyer personnel attended a site meeting on September 16, 2019 to observe the reported slope failure along the eastern pond embankment and discuss the evaluations and analyses that would need to be performed and which could identify potential remedies. It should be noted that Pinellas County reported that the slope failure was potentially caused by means of erosion from waves formed by wind within the pond.

4. The detailed results of the Geophysical Survey are included in the Geophysical Report in the Appendix. Underground utilities were identified in the area of the pump house and along the southern berm of the pond. No utilities were identified in the planned improvement location on the northern berm of the pond. No buried rip‐rap was identified within the survey limits.

5. MC2 performed four (4) test pit excavations in the areas of the proposed winch pad and pond intake pump structures which were further deepened with HA borings to explore the possibility of rip‐rap being buried near the shorelines. Based on the test pits performed and geophysical results, rip‐rap was not encountered. It is our opinion that a rubble rip‐ rap slope protection layer likely does not exist near the proposed improvements. However, the contractor should come prepared to excavate rip‐rap material, if indeed such is encountered during construction. Any area(s) that is excavated would need to be backfilled with structural fill, as discussed herein.

6. MC2 performed a slope stability analysis of the proposed winch pads on May 18, 2018 which indicated a Factor of Safety (FS) of 1.4. Generally, a FS of at least 2.0 is preferred.

Section 7.1 includes recommendations that could increase the FS to this minimum preferred level.

7. The 100% Site Plans provided by Hazen and Sawyer indicated that the winch pads will be 18’ x 4’ x 5’ (length x width x foundation depth bgs) while the pond intake pump pad will be 22’ 8” x 18’ x 3’. This is similar to the dimensions provided in the 60% Site Plans and analyzed in our report for MC2 Project No. T021814.032 dated May 18, 2018. It is our professional opinion that the analysis in our previous report, which included bearing capacity and estimated settlement of the proposed improvements, is still valid so long as the recommendations previously made and reiterated herein for ground improvement and pond embankment repair are followed.

7 RECOMMENDATIONS

7.1 Slope Repair

It is our understanding that the preferred method of repairing the eastern pond embankment is backfilling and compacting soil, similar to the embankment’s design prior to failure. To reconstruct the pond embankment by means of backfilling and compacting, the following recommendations are provided.

Dewatering

The pond water will need to be removed from the eastern slope in order to provide a safe, dry working area for the embankment repair. We anticipate that cofferdam construction and dewatering will be required in order to access the pond bottom for removal of the eroded soils and repair of the embankment.

During placement and compaction of fill material, groundwater levels should be kept at least 12 inches below the working area to facilitate proper material placing and compaction. In some instances, it may be necessary to lower the ground water even further, if adequate compaction cannot be achieved with the groundwater lowered to only 12‐in. below the excavation depths.

Site Preparation

Site preparation for embankment repair should include stripping/removal of all eroded soils and encountered organic material (≥5% organic content) where present prior to any backfilling being performed. We recommend that any exposed surface area to receive fill be evaluated by proofrolling prior to fill placement. Proofrolling is generally performed by traversing the construction areas with a loaded dump truck or similar compaction equipment weighing at least 20 tons. However, using this type of equipment may not be practicable and the contractor should come prepared with alternative proofrolling equipment that would be more effective under these circumstances of space constraints, etc. Proofrolling operations should be observed by a representative of MC2. Unstable soils which are revealed by proofrolling and which cannot be adequately densified in place should be removed and replaced under the recommendations of a MC2 representative.

After clearing, grubbing and proofrolling, the exposed subgrade soils that are to receive fill material shall be compacted to a minimum of 95% of the soil’s modified Proctor maximum dry density and +/‐ 2% of the optimum moisture content, as determined by ASTM designation D‐1557.

Selection and Placement of Fill

All materials to be used for backfill or compacted fill during construction should be evaluated and, if necessary, tested by MC2 prior to placement to determine if they are suitable for the intended use. Based on the borings performed, the majority of the shallow, on site sandy materials encountered (SP, SP‐SM) is suitable for use as structural fill, general fill and backfill. Otherwise, imported fill will be necessary if not enough soils on‐site are available. Suitable structural fill materials should consist of fine to medium sand with less than 12% passing the No. 200 sieve (SP‐ SM) and be free of rubble, organics, clay, debris and other unsuitable material.

The pond embankment soils should generally be compacted to 95% of the modified Proctor maximum dry density while within +/‐ 2% of the material’s optimum moisture content. Areas near existing structures and beneath proposed improvements should be compacted to 98% of the modified Proctor maximum dry density while within +/‐ 2% of the material’s optimum moisture content, as determined by ASTM designation D‐1557.

The fill material needed should be placed in level lifts not to exceed 12‐inches loose thickness. The slopes of the embankment should stand no steeper than a 1 (H): 1 (V) grade.

The horizontal length of fill placement required will be dependent on the improvements required along the pond bank regarding the desired final ground surface elevation to the bottom of the excavation/repair depths (vertical height). In general, a minimum horizontal length of approximately 10‐ft. into the pond should be anticipated.

Erosion Control

Based on the 100% plans provided by Hazen and Sawyer, a concrete “key” underneath each winch slab and pond intake pump slab that projects at least 18‐in. beneath the slab along its entire width has been incorporated into the design. This addition, along with the following erosion controls, should increase the slope stability FS above 2.0, as well as increase the sliding FS above 2.0.

To prevent erosion of the slope and enhance its stability, a geogrid system is recommended to be used such as Stratagrids or equivalent. The Stratagrids or equivalent can be combined with traditional erosion protection products or vegetation or rip‐rap. For slopes 1H:1V or flatter, primary and secondary geogrids with erosion protection products/vegetation will create a reinforced slope. Rip‐ rap or other protection products such as gabions or fabriform have been proven methods in the past at mitigating erosion caused by water. Fabriform could be used and placed per manufacturer’s recommendations as an alternative to a geogrid system or in combination with a geogrid system to provide additional reinforcement to reduce erosion caused by water. Rip‐rap should be “chinked” meaning hand‐placing stones in a manner that fills in the narrow openings between larger stones with smaller ones.

7.2 Foundation Construction

After clearing, grubbing and proofrolling, the upper 12 inches of the subgrade in the area of any structure and 3‐ft. around the perimeter shall be compacted to a minimum of 98% of the soil’s modified Proctor maximum dry density and +/‐ 2% of the optimum moisture content, as determined by ASTM designation D‐1557 before any fill placement is performed.

The upper 2‐ft of the foundation bearing surface and 3‐ft. beyond the perimeter of the structures should be compacted to a minimum of 98% of the modified Proctor maximum dry density while within +/‐ 2% of the material’s optimum moisture content. If these compaction requirements are not achievable, then the material must be over‐excavated at least 1‐ft. and backfilled with either clean fill, lean concrete, or course stone wrapped in a geotextile.

Where structural fill is needed, the fill should be placed in level lifts not to exceed 12‐inches loose thickness. The fill should be compacted to a minimum of 98% of the soil’s modified Proctor maximum dry density and +/‐ 2% of the optimum moisture content.

Backfilling in areas requiring over‐excavation may also be done with a very lean concrete or with a well‐compacted, suitable fill such as clean sand, gravel, or crushed #57 or #67 stone wrapped in a geotextile fabric.

7.3 Friction Coefficients

Friction coefficients between materials were requested to aid in the design of the proposed improvements. Specifically, the coefficient of friction (μ) between high‐density polyethylene (HDPE) pipe and the encountered on‐site soils, in this case sand, and placed gravel (crushed stone) were requested. We have provided the static coefficient of friction values since they are generally larger than dynamic (kinetic) friction values. The typical μ between HDPE and sand is generally 0.2 to 0.25 and μ between HDPE and gravel (crushed stone) ranges from 0.15 to 0.3. The designer should also contact the pipe supplier/manufacturer to provide additional product information for design support.

8 REPORT LIMITATIONS

The recommendations detailed herein are based on the available limited soil information obtained by MC2 and information provided by Hazen and Sawyer for the proposed project. If there are any revisions to the plans for this project or if deviations from the subsurface conditions noted in this report are encountered during construction, MC2 should be notified immediately to determine if changes of recommendations are required. If MC2 is not retained to perform these functions, MC2 cannot be responsible for the impact of those conditions on the performance of the project.

The geotechnical engineer warrants that the findings, recommendations, specifications, or professional advice contained herein have been made in accordance with generally accepted professional geotechnical engineering practices in the local area. No other warranties are implied or expressed.

After the plans and specifications are more complete, the geotechnical engineer should be provided the opportunity to review the final design plans and specifications to assess that our engineering recommendations have been properly incorporated into the design documents. At that time, it may be necessary to submit supplementary recommendations. This report has been prepared for the exclusive use of Hazen and Sawyer.

APPENDIX

Summary of Soil Parameters – Table No. 4

Project Location Map – Sheet 1 Boring Location Map – Sheet 2

USDA Soil Survey and USGS Topographic Map – Sheet 3 Subsurface Boring Profile – Sheet 4

Legend – Sheet 5 Individual Soil Profiles (8 Sheets)

Table No. 4 Summary of Soil Parameters

Pinellas County Waste to Energy Industrial Water Treatment Plant Pond and Slope Repair

Pinellas County, Florida MC2 Project No. T041905.096

Boring

ID

Depth (ft) N Value Soil Classification

Average Unit Weight (γ)** Angle of

Internal

Friction

Ø **

(degrees)

Earth Pressure Coefficients* Average

Undrained

Cohesion

Cu **

(psf)

Saturated

(pcf)

Submerged

(pcf)

At Rest

(Ko)

Active

(Ka)

Passive

(Kp)

Proposed Structures

SPT‐03

0‐8 12 SP, SP‐SM 105.0 42.6 29 0.515 0.347 2.88 0

8‐10 5 SC 105.0 42.6 0 1.000 1.000 1.00 500

10‐14 7 SP‐SM 105.0 42.6 29 0.515 0.347 2.88 0

14‐20 2 SC, CL 100.0 37.6 28 0.361 2.77 0

SPT‐04

0‐10 9 SP, SP‐SM 105.0 42.6 29 0.515 0.347 2.88 0

10‐14 1 SP‐SM 100.0 37.6 26 0.391 2.56 0

14‐16 0 SC 100.0 37.6 26 1.000 0.391 2.56 0

16‐20 3 SC 100.0 37.6 28 0.361 2.77 0

*Values are for level (non‐sloping) backfill; no surcharge loads on backfill

**Based on empirical correlations

NAMEDATE APPROVED BY:REVISION

SUPERVISED BY:

CHECKED BY:

DRAWN BY:

DESIGNED BY:

SHEET NO.MC PROJ. NO.2

T041905.096 5808-A Breckenridge Parkway Tampa, FL 33610 Ph:813-623-3399 Fax:813-623-6636

Geotechnical Consultants MC SQUARED, INC. Project Location MapDATENAME

Approximate Project Location

LEGEND:

Project Location

Pinellas County Waste to Energy Facility Industrial Water Treatment Plant Pond Intake Improvements and Slope Repair

Pinellas County, FloridaWS

11/7/2019 11/7/2019 11/7/2019

DP

DP

JH

Source: Google Earth Image Date: 1/9/2019

AutoCAD SHX Text Jeffery L. Hooks, P.E.

AutoCAD SHX Text FLORIDA LICENSE No. 67882

AutoCAD SHX Text

FLORIDA ENGINEERING CERTIFICATE OF

AutoCAD SHX Text AUTHORIZATION No. 9191

AutoCAD SHX Text 0'

AutoCAD SHX Text 1000'

AutoCAD SHX Text 2000'

AutoCAD SHX Text Graphic Scale (feet)

SUPERVISED BY:

CHECKED BY:

DRAWN BY:

DESIGNED BY:

SHEET NO.MC PROJ. NO.2

5808-A Breckenridge Parkway Tampa, FL 33610 Ph:813-623-3399 Fax:813-623-6636

Geotechnical Consultants MC SQUARED, INC. Boring Location MapDATENAME

Source: Google Earth Image Date: 1/9/2019Approximate SPT Boring Location

LEGEND:

Pinellas County Waste to Energy Facility Industrial Water Treatment Plant Pond Intake Improvements and Slope Repair

Pinellas County, Florida T041905.096

WS

11/7/2019 11/7/2019 11/7/2019

DP

DP

JH

SPT-04

SPT-03

TP-03

TP-02

TP-01

TP-04

Approximate Test Pit Location

SPT-02

SPT-01

AutoCAD SHX Text Jeffery L. Hooks, P.E.

AutoCAD SHX Text FLORIDA LICENSE No. 67882

AutoCAD SHX Text

FLORIDA ENGINEERING CERTIFICATE OF

AutoCAD SHX Text AUTHORIZATION No. 9191

AutoCAD SHX Text 0'

AutoCAD SHX Text 100'

AutoCAD SHX Text 200'

Graphic Scale (feet)

SUPERVISED BY:

CHECKED BY:

DRAWN BY:

DESIGNED BY:

SHEET NO.MC PROJ. NO.2

5808-A Breckenridge Parkway Tampa, FL 33610 Ph:813-623-3399 Fax:813-623-6636

Geotechnical Consultants MC SQUARED, INC. USDA Soil Survey and USGS Topographic MapDATENAME

Pinellas County Waste to Energy Facility Industrial Water Treatment Plant Pond Intake Improvements and Slope Repair

Pinellas County, Florida T041905.096

WS

11/7/2019 11/7/2019 11/7/2019

DP

DP

JH

SAFETY HARBOR QUADRANGLE

FLORIDA-PINELLAS CO.

7.5 MINUTE SERIES TOPOGRAPHIC

NAVD: 1988 - DATE: 2018

Approximate Project Location

Source: Natural Resources Conservation Service The survey data is Version 16 dated Sep 17, 2019, with aerial images taken Dec 17, 2013 to Feb 28, 2014.

AutoCAD SHX Text Jeffery L. Hooks, P.E.

AutoCAD SHX Text FLORIDA LICENSE No. 67882

AutoCAD SHX Text

FLORIDA ENGINEERING CERTIFICATE OF

AUTHORIZATION No. 9191

Date : 9/7/2017

WT: 9'

Boring No. : SPT-01 Date : 9/6/2017

WT: 9'

Boring No. : SPT-02

N

N Date : 10/18/2019 Boring No. : SPT-03

N

WOH (12'-14.5')

Boring Terminated at 34 ft.

Boring Terminated at 20 ft.

Date : 10/18/2019 Boring No. : SPT-04

N

Boring Terminated at 20 ft.

50/4"

50/1"

Boring Terminated at 38 ft.

40 40

D

EP

TH

(F

EE

T)

D

EP

TH

(F

EE

T)

Date : 10/18/2019

WT: GNA

Boring No. : SPT-03 Date : 10/18/2019

WT: 8'

Boring No. : SPT-04

NMC: 32.1%

-200: 64.5%

NMC: 24.9%

-200: 22.2%

NMC: 28.7%

-200: 27.4%

NMC: 25.9%

-200: 25.2%

PL: 18

LL: 28

PI: 10

NMC: 18.3%

-200: 3.4%

WOH (14'-16')

WOH (18'-18.5')NMC: 25.0%

-200: 15.8%

NMC: 32.2%

-200: 51.6%

PL: 13

LL: 30

PI: 17

NMC: 23.5%

-200: 53.0%

PL: 20

LL: 42

PI: 22

NMC:31.3%

-200: 76.3%

PL: 17

LL: 32

PI: 15

NMC: 32.3%

-200: 77.3%

PL: 19

LL: 29

PI: 10

NMC: 33.4%

-200: 80.4%

PL: 19

LL: 30

PI: 11

NMC: 15.4%

-200: 24.3%

NMC: 44.6%

-200: 40.3%

WOH (16'-17.5')

No Recovery (28'-30')

Washed Down (4'-8')Washed Down (4'-8')

WOH (30'-30.5')

WOH (20'-21')

WOH (22'-23')

WOR (18'-18.5')

NAMEDATE APPROVED BY:REVISION

SUPERVISED BY:

CHECKED BY:

DRAWN BY:

DESIGNED BY:

SHEET NO.MC PROJ. NO.2

5808-A Breckenridge Parkway Tampa, FL 33610 Ph:813-623-3399 Fax:813-623-6636

Geotechnical Consultants MC SQUARED, INC. Subsurface Boring ProfileDATENAME

Pinellas County Waste to Energy Facility Industrial Water Treatment Plant Pond Intake Improvements and Slope Repair

Pinellas County, Florida T041905.096

WS

11/7/2019 11/7/2019 11/7/2019

DP

DP

JH

*N Values Drawn At Top Of Interval

AutoCAD SHX Text Jeffery L. Hooks, P.E.

AutoCAD SHX Text FLORIDA LICENSE No. 67882

AutoCAD SHX Text

FLORIDA ENGINEERING CERTIFICATE OF

LEGEND

(SP) Poorly Graded Sand

NOTES:

Water Table After 24 Hours Water Table At Time Of Drilling

(SM) Silty Sand

(SP-SM) Poorly Graded Sand With Silt

(SC) Clayey Sand

(SP-SC) Poorly Graded Sand With Clay

(CL) Lean Clay

(CH) Plastic Clay

(MH) Elastic Silt

(ML) Silt

Limestone

Asphalt

Bedrock

Concrete

Soil Cement

Peat

Top Soil (CL-ML) Silty Clay

Groundwater Not Encountered GNA Groundwater Not Apparent

CL Center Line RT Right Of Center Line LT Left of Center Line

HA Hand Auger PA Power Auger

NMC Natural Moisture Content (%) -200 Fines Passing A No. 200 Sieve (%)

PI Plasticity Index NP Non Plastic LL Liquid Limit

OC Organic Content (%)

N SPT N-Value WOH Weight-Of-Hammer WOR Weight-Of-Rod CPT Cone Penetrometer Test SPT Standard Penetration Test

DT Dilatometer Test LOC Loss Of Circulation ROC Regain Of Circulation REC Rock Core Recovery(%) RQD Rock Quality Designation

ST Shelby Tube Sample

Granite

Schist

Gneiss

(GAB) Graded Aggregate Base

Limerock Base

(OH) Organic Clay

(OL) Organic Silt

(WLS) Weathered Limestone

(PWR) Partially Weathered Rock

GNE

qᵤ Unconfined Compressive Strength From Pocket Penetrometer In tsf

BGS Below Ground Surface

No. 57 Stone

GNM Groundwater Not Measured

Fill

GRANULAR MATERIALS- RELATIVE DENSITY

VERY LOOSE

LOOSE

MEDIUM

DENSE

VERY DENSE

SILTS AND CLAYS CONSISTENCY

VERY SOFT

SOFT

FIRM

STIFF

VERY STIFF

HARD

SPT Spoon Inside Diameter 1 3/8" SPT Spoon Outside Diameter 2"

ASTM Auto Hammer Average Hammer Drop Height 30" Hammer Weight 140 lbs

AUTO HAMMER SPT N-VALUES

£ 3 3-8 8-24 24-40

GREATER THAN 40

£ 1 1-3 3-6 6-12 12-24

GREATER THAN 24

AUTO HAMMER SPT N-VALUES

NAMEDATE APPROVED BY:REVISION

SUPERVISED BY:

CHECKED BY:

DRAWN BY:

DESIGNED BY:

SHEET NO.MC PROJ. NO.2

5808-A Breckenridge Parkway Tampa, FL 33610 Ph:813-623-3399 Fax:813-623-6636

Geotechnical Consultants MC SQUARED, INC. LegendDATENAME

Pinellas County Waste to Energy Facility Industrial Water Treatment Plant Pond Intake Improvements and Slope Repair

Pinellas County, Florida T041905.096

WS

11/7/2019 11/7/2019 11/7/2019

DP

DP

JH

AutoCAD SHX Text Jeffery L. Hooks, P.E.

AutoCAD SHX Text FLORIDA LICENSE No. 67882

AutoCAD SHX Text

FLORIDA ENGINEERING CERTIFICATE OF

2-7-4-3 (11)

2-1-1-1 (2)

0-0-0-0 (0)

0-2-2-3 (4)

1-1-1-1 (2)

0-1-1-1 (2)

0-0-1-2 (1)

0-0-2-1 (2)

1-1-1-1 (2)

0-2-1-1 (3)

1-1-1-1 (2)

0-1-2-1 (3)

0-3-6-9 (9)

HA

HA

SS

SS

SS

SS

SS

SS

SS

SS

SS

SS

SS

SS

SS

SS

SS

Grayish brown, poorly graded fine SAND with silt

Shell fragments (0' - 4')

No recovery from 4 to 8 feet.

Medium dense, dark gray, poorly graded fine SAND with silt

Shell fragments (8' - 10')

Very loose, dark gray, silty SAND

Very soft, greenish gray, sandy CLAY

WOH (12' - 14.5')

Very loose, gray, clayey fine SAND

WOR (18' - 18.5')

WOH (20' - 21')

Very soft to stiff, gray to light gray, greenish gray, sandy CLAY with limestone fragments

WOH (22' - 23')

WOH (30' - 30.5')

Bottom of hole at 34.0 feet.

SP-SM

SP-SM

SM

CL ,CH

SC

CL

GROUND ELEVATION 11 ft

LOGGED BY BC

DRILLING METHOD Mud Rotary AT TIME OF DRILLING 9.0 ft / Elev 2.0 ft

AT END OF DRILLING ---

AFTER DRILLING ---

HOLE SIZE 4 inches

DRILLING CONTRACTOR Tierra GROUND WATER LEVELS:

CHECKED BY JH

DATE STARTED 9/7/17 COMPLETED 9/7/17

NOTES LAT: 27.8769, LONG: -82.6805

ORGANIC CONTENT %

2 5 5 0 7 5

D E

P T

H ft

SPT N VALUE

20.8 40.6 60.4 80.2

G R

A P

H

IC

L O

G

R E

C O

V E

R Y

(R

Q D

B

LO

W C

O U

N T

S (N

V A

LU

E

S A

M P

LE

T

Y P

E N

U M

B E

R

MATERIAL DESCRIPTION

U S

C S

G ro up S ym bo l

FINES CONTENT (%)

20 40 60 80

2 5 5 0 7 5

PL LLMC

M C

R

E P

O R

T T

.0

6.

G P

J M

C 2.

G D

T

/8 /2

CLIENT Hazen and Sawyer

PROJECT NUMBER T041905.096

PROJECT NAME Waste to Energy IWTP Pond Intake Improvements

PROJECT LOCATION Pinellas County, Florida

BORING ID: SPT-01BORING ID: SPT-01Soil Profile

5-9-11-7 (20)

4-8-10-7 (18)

3-1-1-1 (2)

1-1-2-1 (3)

0-0-0-1 (0)

1-1-1-0 (2)

0-1-1-1 (2)

0-1-1-2 (2)

0-0-0-0 (0)

0-1-1-2 (2)

50/4"

50/1"

1-2-3-5 (5)

2-2-2-3 (4)

HA

HA

SS

SS

SS

SS

SS

SS

SS

SS

SS

SS

SS

SS

SS

SS

SS

SS

SS

Grayish brown to dark gray, poorly graded fine SAND with silt

Shell fragments (0' - 4')

Dark gray, clayey fine SAND No recovery from 4 to 8 feet.

Medium dense, light gray, poorly graded fine SAND with silt

Shell fragments (8' - 12')

Very loose, dark gray, silty fine SAND

Soft, greenish gray, fat sandy CLAY

Loose, gray, clayey fine SAND

WOH (16' - 17.5')

Very soft, very light gray, sandy CLAY with limestone fragments

Shell fragments (18' - 20')

No recovery from 28 to 30 feet.

Very dense, very light gray, clayey GRAVEL

Very loose to loose, greenish gray, clayey fine SAND

Bottom of hole at 38.0 feet.

SP-SM

SC

SP-SM

SM

CL, CH

SC

CL

GC

SC

GROUND ELEVATION 11 ft

LOGGED BY BC

DRILLING METHOD Mud Rotary AT TIME OF DRILLING 9.0 ft / Elev 2.0 ft

AT END OF DRILLING ---

AFTER DRILLING ---

HOLE SIZE 4 inches

DRILLING CONTRACTOR Tierra GROUND WATER LEVELS:

CHECKED BY JH

DATE STARTED 9/6/17 COMPLETED 9/6/17

NOTES LAT: 27.8763, LONG: -82.6802

ORGANIC CONTENT %

2 5 5 0 7 5

D E

P T

H ft

SPT N VALUE

20.8 40.6 60.4 80.2

G R

A P

H

IC

L O

G

R E

C O

V E

R Y

(R

Q D

B

LO

W C

O U

N T

S (N

V A

LU

E

S A

M P

LE

T

Y P

E N

U M

B E

R

MATERIAL DESCRIPTION

U S

C S

G ro up S ym bo l

FINES CONTENT (%)

20 40 60 80

2 5 5 0 7 5

PL LLMC

M C

R

E P

O R

T T

.0

6.

G P

J M

C 2.

G D

T

/8 /2

CLIENT Hazen and Sawyer

PROJECT NUMBER T041905.096

PROJECT NAME Waste to Energy IWTP Pond Intake Improvements

PROJECT LOCATION Pinellas County, Florida

BORING ID: SPT-02BORING ID: SPT-02Soil Profile

1-4-10-9 (14)

10-9-8-7 (17)

6-5-5-5 (10)

3-4-6-8 (10)

3-2-3-2 (5)

1-3-5-4 (8)

2-3-2-2 (5)

2-3-2-2 (5)

1-1-0-1 (1)

2-1-1-1 (2)

SS

SS

SS

SS

SS

SS

SS

SS

SS

SS

Medium dense, grayish brown to dark grayish brown, poorly-graded fine SAND to fine SAND with silt

Loose, greenish gray, clayey fine SAND with shell

Loose, gray to grayish brown, poorly-graded fine SAND with silt with shell and concrete debris

Very loose to loose, grayish brown, gray, clayey fine SAND

Soft, gray, sandy lean CLAY with shell and LIMESTONE fragments

Bottom of hole at 20.0 feet.

SP, SP-

SM

SC

SP-SM

SC

CL

GROUND ELEVATION

LOGGED BY NK

DRILLING METHOD Wet Rotary AT TIME OF DRILLING GNA

AT END OF DRILLING ---

AFTER DRILLING ---

HOLE SIZE 4 Inches

DRILLING CONTRACTOR Standard Drilling GROUND WATER LEVELS:

CHECKED BY JH

DATE STARTED 10/18/19 COMPLETED 10/18/19

NOTES Auto Hammer

ORGANIC CONTENT %

2 5 5 0 7 5

D E

P T

H ft

SPT N VALUE

20.8 40.6 60.4 80.2

G R

A P

H

IC

L O

G

R E

C O

V E

R Y

(R

Q D

B

LO

W C

O U

N T

S (N

V A

LU

E

S A

M P

LE

T

Y P

E N

U M

B E

R

MATERIAL DESCRIPTION

U S

C S

G ro up S ym bo l

FINES CONTENT (%)

20 40 60 80

2 5 5 0 7 5

PL LLMC

M C

R

E P

O R

T T

.0

6.

G P

J M

C 2.

G D

T

/8 /2

CLIENT Hazen and Sawyer

PROJECT NUMBER T041905.096

PROJECT NAME Waste to Energy IWTP Pond Intake Improvements

PROJECT LOCATION Pinellas County, Florida

BORING ID: SPT-03BORING ID: SPT-03Soil Profile

3-5-4-5 (9)

4-4-4-4 (8)

2-3-6-5 (9)

5-5-4-4 (9)

4-5-6-8 (11)

4-1-1-3 (2)

3-1-0-1 (1)

0-0-0-0 (0)

2-2-1-2 (3)

0-1-2-2 (3)

SS

SS

SS

SS

SS

SS

SS

SS

SS

SS

Loose to medium dense, brownish yellow to light gray, pale brown, poorly-graded fine SAND to fine SAND with silt

Medium dense, gray, poorly-graded fine SAND

Very loose, grayish brown, poorly-graded fine SAND with silt with shells and some organics

Very loose to loose, greenish gray to light gray, poorly-graded fine SAND with clay with shell and LIMESTONE fragments

Weight of Hammer (14'-16')

Weight of Hammer (18'-18.5')

Bottom of hole at 20.0 feet.

SP, SP-

SM

SP

SP-SM

SC

GROUND ELEVATION

LOGGED BY NK

DRILLING METHOD Wet Rotary AT TIME OF DRILLING 8.0 ft

AT END OF DRILLING ---

AFTER DRILLING ---

HOLE SIZE 4 Inches

DRILLING CONTRACTOR Standard Drilling GROUND WATER LEVELS:

CHECKED BY JH

DATE STARTED 10/18/19 COMPLETED 10/18/19

NOTES Auto Hammer

ORGANIC CONTENT %

2 5 5 0 7 5

D E

P T

H ft

SPT N VALUE

20.8 40.6 60.4 80.2

G R

A P

H

IC

L O

G

R E

C O

V E

R Y

(R

Q D

B

LO

W C

O U

N T

S (N

V A

LU

E

S A

M P

LE

T

Y P

E N

U M

B E

R

MATERIAL DESCRIPTION

U S

C S

G ro up S ym bo l

FINES CONTENT (%)

20 40 60 80

2 5 5 0 7 5

PL LLMC

M C

R

E P

O R

T T

.0

6.

G P

J M

C 2.

G D

T

/8 /2

CLIENT Hazen and Sawyer

PROJECT NUMBER T041905.096

PROJECT NAME Waste to Energy IWTP Pond Intake Improvements

PROJECT LOCATION Pinellas County, Florida

BORING ID: SPT-04BORING ID: SPT-04Soil Profile

HA

Dark grayish brown, pale brown, brown, gray, poorly-graded fine SAND to fine SAND with silt and shell

Bottom of test pit at 10.0 feet.

SP, SP-

SM

GROUND ELEVATION

LOGGED BY NK

EXCAVATION METHOD Excavator and Hand Auger AT TIME OF EXCAVATION 9.0 ft

AT END OF EXCAVATION ---

AFTER EXCAVATION ---

TEST PIT SIZE 4 Inches

EXCAVATION CONTRACTOR MC Squared, Inc, GROUND WATER LEVELS:

CHECKED BY JH

DATE STARTED 10/10/19 COMPLETED 10/10/19

NOTES 5-ft x 10-ft x 10-ft

ORGANIC CONTENT %

2 5 5 0 7 5

D E

P T

H ft

SPT N VALUE

20.8 40.6 60.4 80.2

G R

A P

H

IC

L O

G

R E

C O

V E

R Y

(R

Q D

B

LO

W C

O U

N T

S (N

V A

LU

E

S A

M P

LE

T

Y P

E N

U M

B E

R

MATERIAL DESCRIPTION

U S

C S

G ro up S ym bo l

FINES CONTENT (%)

20 40 60 80

2 5 5 0 7 5

PL LLMC

M C

R

E P

O R

T T

.0

6.

G P

J M

C 2.

G D

T

/8 /2

CLIENT Hazen and Sawyer

PROJECT NUMBER T041905.096

PROJECT NAME Waste to Energy IWTP Pond Intake Improvements

BORING ID: TP-01BORING ID: TP-01Soil Profile

Dark grayish brown, dark gray, poorly-graded fine SAND to fine SAND with silt and shell

Bottom of test pit at 12.0 feet.

SP-SM

GROUND ELEVATION

LOGGED BY NK

EXCAVATION METHOD Excavator and Hand Auger AT TIME OF EXCAVATION GNE

AT END OF EXCAVATION ---

AFTER EXCAVATION ---

TEST PIT SIZE 4 Inches

EXCAVATION CONTRACTOR MC Squared, Inc, GROUND WATER LEVELS:

CHECKED BY JH

DATE STARTED 10/11/19 COMPLETED 10/11/19

NOTES 5-ft x 10-ft x 12-ft

ORGANIC CONTENT %

2 5 5 0 7 5

D E

P T

H ft

SPT N VALUE

20.8 40.6 60.4 80.2

G R

A P

H

IC

L O

G

R E

C O

V E

R Y

(R

Q D

B

LO

W C

O U

N T

S (N

V A

LU

E

S A

M P

LE

T

Y P

E N

U M

B E

R

MATERIAL DESCRIPTION

U S

C S

G ro up S ym bo l

FINES CONTENT (%)

20 40 60 80

2 5 5 0 7 5

PL LLMC

M C

R

E P

O R

T T

.0

6.

G P

J M

C 2.

G D

T

/8 /2

CLIENT Hazen and Sawyer

PROJECT NUMBER T041905.096

PROJECT NAME Waste to Energy IWTP Pond Intake Improvements

BORING ID: TP-02BORING ID: TP-02Soil Profile

Dark gray, grayish brown to dark grayish brown, poorly-graded fine SAND with silt and shell

Bottom of test pit at 9.0 feet.

SP-SM

GROUND ELEVATION

LOGGED BY NK

EXCAVATION METHOD Excavator and Hand Auger AT TIME OF EXCAVATION GNE

AT END OF EXCAVATION ---

AFTER EXCAVATION ---

TEST PIT SIZE 4 Inches

EXCAVATION CONTRACTOR MC Squared, Inc, GROUND WATER LEVELS:

CHECKED BY JH

DATE STARTED 10/11/19 COMPLETED 10/11/19

NOTES 5-ft x 10-ft x 9-ft

ORGANIC CONTENT %

2 5 5 0 7 5

D E

P T

H ft

SPT N VALUE

20.8 40.6 60.4 80.2

G R

A P

H

IC

L O

G

R E

C O

V E

R Y

(R

Q D

B

LO

W C

O U

N T

S (N

V A

LU

E

S A

M P

LE

T

Y P

E N

U M

B E

R

MATERIAL DESCRIPTION

U S

C S

G ro up S ym bo l

FINES CONTENT (%)

20 40 60 80

2 5 5 0 7 5

PL LLMC

M C

R

E P

O R

T T

.0

6.

G P

J M

C 2.

G D

T

/8 /2

CLIENT Hazen and Sawyer

PROJECT NUMBER T041905.096

PROJECT NAME Waste to Energy IWTP Pond Intake Improvements

BORING ID: TP-03BORING ID: TP-03Soil Profile

Dark grayish brown, gray, poorly-graded fine SAND to fine SAND with silt and shell and debris

Bottom of test pit at 11.0 feet.

SP, SP-

SM

GROUND ELEVATION

LOGGED BY NK

EXCAVATION METHOD Excavator and Hand Auger AT TIME OF EXCAVATION 10.0 ft

AT END OF EXCAVATION ---

AFTER EXCAVATION ---

TEST PIT SIZE 4 Inches

EXCAVATION CONTRACTOR MC Squared, Inc, GROUND WATER LEVELS:

CHECKED BY JH

DATE STARTED 10/10/19 COMPLETED 10/10/19

NOTES 5-ft x 10-ft x 11-ft

ORGANIC CONTENT %

2 5 5 0 7 5

D E

P T

H ft

SPT N VALUE

20.8 40.6 60.4 80.2

G R

A P

H

IC

L O

G

R E

C O

V E

R Y

(R

Q D

B

LO

W C

O U

N T

S (N

V A

LU

E

S A

M P

LE

T

Y P

E N

U M

B E

R

MATERIAL DESCRIPTION

U S

C S

G ro up S ym bo l

FINES CONTENT (%)

20 40 60 80

2 5 5 0 7 5

PL LLMC

M C

R

E P

O R

T T

.0

6.

G P

J M

C 2.

G D

T

/8 /2

CLIENT Hazen and Sawyer

PROJECT NUMBER T041905.096

PROJECT NAME Waste to Energy IWTP Pond Intake Improvements

BORING ID: TP-04BORING ID: TP-04Soil Profile

FINAL REPORT

GEOPHYSICAL INVESTIGATION

PINELLAS IWTP INTAKE SITE

Prepared for MC Squared, Inc.

Tampa, FL

Prepared by GeoView, Inc.

St. Petersburg, FL

October 21, 2019

Mr. Jeffery Hooks, P.E.

MC Squared, Inc.

5808-A Breckenridge Parkway Tampa, FL 33610

Subject: Transmittal of Final Report for Geophysical Investigation Pinellas IWTP Intake Site GeoView Project Number 30438

Dear Mr. Hooks, GeoView, Inc. (GeoView) is pleased to submit the final report that summarizes and presents the results of the geophysical investigation conducted at a Pinellas IWTP Intake Site. The purpose of the geophysical investigation was to determine the presence and location of underground utilities and to help determine if buried rip rap was present along the western boundary of the pump facility.

GeoView appreciates the opportunity to have assisted you on this project. If you have any questions or comments about the report, please contact us.

GEOVIEW, INC.

Michael J. Wightman, P.G.

President

Florida Professional Geologist Number 1423

A Geophysical Services Company

4610 Central Avenue Tel: (727) 209-2334 Tampa, FL 33711 Fax: (727) 328-2477

1.0 Introduction

The project site is referred to as the Pinellas IWTP Intake Site and is located within the Pinellas County Solid Waste facility at 3095 114th Avenue North in Clearwater, Florida. The project site consisted of three areas:

A one-quarter acre area centered about the existing pump facility.

Two 10-foot by 10-foot areas on the south and north berms of the reservoir where geotechnical borings are planned.

Of concern to the investigation was the location of underground utilities and any other buried obstructions within the study area. Buried objects of specific concern other than utilities was the presence and lateral extent of buried concrete rip-rap that might be present along the western boundary of the pump facility. The location of the study area is shown on Figure 1.

2.0 Description of Geophysical Investigation

2.1 Underground Utility Designation

The underground utility designation portion of the investigation was conducted using ground penetrating radar (GPR) and electronic utility locate (EUL) equipment. The EUL was used to identify any underground utilities that were either carrying electrical power or could be energized by an induced electrical current. The GPR was used to help identify both electrical and non-electrical underground utilities within the survey area.

The GPR survey was performed using a Mala GPR system with a 500 mega- Hertz antenna and time range of 50 nano seconds. This equipment configuration provided an estimated depth of investigation of 5 to 6 feet (ft) below land surface (bls). The EUL survey was performed with a Radio Detection 8100.

A combination of two geophysical methods was used for the site investigation. The two selected methods are complementary, in that, the EUL can accurately and rapidly detect many types of underground utilities. GPR, which is slower, can then be used to confirm the results of the EUL survey and to identify other underground utilities that are non-detectible by the EUL. It is typically possible to evaluate the burial depth of the underground utilities using both methods.

2.2 Buried Rip-Rap

GPR and time domain electromagnetics (TDEM) were used to determine the possible presence and lateral extent of buried rip-rap.