FINAL REPORT OF GEOTECHNICAL INVESTIGATIONcms.leoncountyfl.gov/Portals/0/Purchasing/Docs/Supplemental Documents/2018/woodside...Senior Geotechnical Engineer for this investigation

FINAL REPORT OF GEOTECHNICAL INVESTIGATION

PUMP STATION WOODSIDE HEIGHTS WASTEWATER RETROFIT

LEON COUNTY, FLORIDA Prepared For:

GENESIS GROUP, INC. 2507 CALLAWAY ROAD

SUITE 100 TALLAHASSEE, FLORIDA 32303

Prepared By:

ENVIRONMENTAL AND GEOTECHNICAL SPECIALISTS, INC.

104 NORTH MAGNOLIA DRIVE TALLAHASSEE, FLORIDA 32301

(850) 386-1253

October 2017 18-139-16-02B

ENVIRONMENTALANDGEOTECHNICALSPECIALISTS,INC.

104NORTHMAGNOLIADRIVE/TALLAHASSEE,FLORIDA32301/ 850 386‐1253/FAX 850 385‐8050

October 23, 2017 EGS File Number: 18-139-16-02B Genesis Group, Inc. 2507 Callaway Road Suite 100 Tallahassee, Florida 32303 ATTN: David Hutcheson, P.E. Vice President SUBJECT: Final Report of Geotechnical Investigation Pump Station

Woodside Heights Wastewater Retrofit Leon County, Florida Dear David:

As authorized by Genesis Group, Inc. (Genesis), Environmental and Geotechnical Specialists, Inc. (EGS) has conducted a geotechnical investigation for the proposed pump station associated with the above referenced project. This investigation was performed in conjunction with the Report of Geophysical Investigation (EGS Project No. 18-139-16-03), which was conducted to evaluate the subsurface conditions and determine if an active karst feature exists below the footprint of the proposed pump station. This Report presents the results of the field investigation, laboratory testing, measured groundwater level, estimated “normal” seasonal high groundwater level, geotechnical design recommendations, and construction considerations.

SCOPE OF SERVICES

The Scope of Services authorized for this subsurface investigation consisted of the following:

Performing a Geophysical Investigation using Electrical Resistivity Imaging (ERI) to evaluate the existence of an active karst feature below the location of the proposed pump station;

Installation of two (2) soil borings to depths of approximately 30 feet below the existing ground;

Conducting standard penetration tests (SPT) to evaluate the relative strength and uniformity of the subsoils;

Testing of representative samples of the subsoils for classification and uniformity;

Genesis Group, Inc. Geotechnical Investigation for Pump Station Woodside Heights Wastewater Retrofit October 23, 2017 Page 2 of 5

Development of geotechnical design parameters; and,

Preparation of geotechnical plan sheet and this Report.

SITE LOCATION AND CONDITIONS

The project site is located in the Woodside Heights subdivision, adjacent to the intersection of Erie Street and Flagg Street in Leon County. A Project Location Map has been included as Figure 1. The United States Geological Survey (USGS) Topographic Survey Contours have been overlain on an aerial map of the project site, provided as Figure 2. In addition, the potential Karst features identified on the Leon County / City of Tallahassee GIS Database have been shown on the aerial map in Figure 2. As can be seen in Figure 2, the existing ground surface is relatively flat, with the elevation varying from approximately EL 40 feet to EL 45 feet. Permanent groundwater is likely at a depth of 10 feet or greater. Photographs of the existing site conditions, taken by EGS personnel March 2017, have been included as Figures 3A and 3B.

PROPOSED CONSTRUCTION

Based upon the Plans provided by Genesis, EGS understands the proposed wastewater pump station will include the addition of a ten (10) feet diameter wet well, as well as the installation of a perimeter fence and a 6 feet by 6 feet concrete pad for a generator. The proposed pump station is within close proximity to private residences in the Woodside Heights subdivision. The primary intent of this geotechnical investigation is to provide subsurface data aid in design and construction of the pump station.

SUBSURFACE INVESTIGATION

The subsurface investigation outlined in this Report was conducted in March 2017. Joshua Jenkins, P.E., was the Project Engineer with the assistance of Kevin Sweeney, E.I., as the Field and Staff Engineer. Myron Hayden, P.E., served as the supervising Senior Geotechnical Engineer for this investigation. EGS installed two (2) soil borings, labeled WH-1 and WH-2, to a depth of 28 and 30 feet, respectively within the proposed area of construction during the geophysical investigation referenced previously. The approximate location of each soil boring is shown in Figure 4. A summary of the soil boring location data has been provided in TABLE 1. In order to minimize potential for impacts to unknown buried utilities, EGS installed the top seven and one-half (7 ½) feet of the soil bring using a hand auger coupled with static hand Cone Penetration Index (CPI) tests conducted on one (1) foot intervals to measure the relative density of the soils. Below seven and one-half (7 ½) feet, SPTs were conducted continuously to a depth of 12 feet and then conducted two and one-half (2 ½) feet intervals to the boring termination depth. All SPT sampling was conducted with an


automatic hammer and in accordance with ASTM D1586. CPI values were converted to equivalent SPT ‘N’ values using the correlation N = CPI/4. Soil samples were collected, classified in the field by EGS personnel, and then sealed and transported to EGS' laboratory for additional testing. The laboratory testing included water content, grain-size distribution determination, and Atterberg limits. The soil samples were classified with respect to the Unified Soil Classification System (USCS). A summary of all testing conducted for this investigation is shown on the Report of Soil Borings provided in Appendix A, along with the Soil Boring Log and the Soil Classification Data provided as Appendices B and C, respectively.

GENERAL SUBSURFACE CONDITIONS

Soils

The soil conditions encountered during this investigation have been illustrated on the Report of Soil Borings provided as APPENDIX A and in the Generalized Soil Profile shown in Figure 5. Additionally, detailed Soil Boring Logs and Soil Classification Data have been provided in APPENDICES B and C, respectively. As can be seen in APPENDIX A and Figure 5, the subsurface soils consist of the about 12 feet of Very Loose to Loose Fine Sand (SP-SM). Underlying the Fine Sand is five (5) to eight (8) feet of Medium Dense Clayey Fine Sand (SC). In Soil Boring WH-1 at a depth of 15 feet is a 12 feet thick layer of Stiff to Very Stiff Plastic Sandy Silt (MH) with Moderately Hard Limestone encountered at about EL 15 feet. In Soil Boring WH-2, at about EL 22.5 feet is a five (5) feet thick layer of Medium Dense Clayey Sand (SC) underlain by at least five (5) feet of Highly Plastic Sandy Silt (MH).

Groundwater

Groundwater was encountered at about EL 18 feet in Soil Boring WH-1 and not encountered (below EL 12.5 feet) in Soil Boring WH-2. A summary of the field encountered groundwater conditions and estimated “normal” seasonal high groundwater at each soil boring location has been presented in TABLE 1. Karst Condition Based on the Geophysical Investigation conducted previously, EGS does not believe that an active karst feature exists below the footprint of this pump station.


GEOTECHNICAL DESIGN RECOMMENDATIONS

The geotechnical design recommendations made by EGS in this Report have been made using the following assumptions: the pump station will be constructed of reinforced concrete; the bottom bearing surface of the pump station will be at or below EL 30 feet; and, the pump station will be at least eight (8) feet in diameter. Subsoil Excavation

Based on the soils data collected during this Geotechnical Investigation, EGS does not believe additional excavation will be necessary beyond what is required to prepare the bearing surface for the pump station foundation in accordance with the COT Technical Specifications for Water and Sewer Construction.

Material Reuse

Based on a review of the soils encountered in this investigation, and the requirements for select backfill provided in the COT Technical Specifications for Water and Sewer Construction, it is expected that the fine sands encountered to a depth of approximately 10 feet will be suitable for reuse as select backfill.

Groundwater Impact and Control

Depending on the depth of the wet well, it is possible groundwater may be encountered during construction of the pump station. Additionally, as previously noted, the plastic silt encountered around EL 27 feet may “perch” groundwater during and after periods of heavy rains and wet weather.

Geotechnical Design Parameters

Based on the soils encountered during this study, assumed foundation dimensions, and subgrade preparations outlined above, the following geotechnical parameters can be used:

Allowable Net Bearing Pressure (qall): 1,000 lb/ft2

Modulus of Subgrade Reaction (Ks): 60,000 lb/ft3

In addition, EGS has provided in TABLE 2 geotechnical design parameters for each of the soil strata encountered.

CONSTRUCTION CONSIDERATIONS

As previously mentioned, existing structures are in close proximity to planned construction throughout the project limits. EGS believes that construction efforts expected for this project, such as vibrations caused by dynamic compaction of pipe subgrade and backfill soils, may cause adverse impacts to these adjacent structures.


Therefore, EGS recommends consideration be given to precluding or minimizing the use of heavy vibratory equipment on this project.

CLOSURE

The data and results presented in this Report are intended for use by Genesis Group, Inc. and the Leon County Department of Public Works for the construction of the Pump Station as part of the Woodside Heights Wastewater Retrofit Project, as identified herein. This data may not be used without the expressed written consent of Genesis Group, Inc. and Leon County Department of Public Works. This Report is not intended for any other use and will likely not be applicable. This Report shall not be reproduced, except in full, without the written approval of Environmental and Geotechnical Specialists, Inc. The data and recommendations presented in this Report are based on soil borings made at the specific locations and depths noted. Subsurface conditions at other locations may vary significantly from those presented herein. Should data become available which is different from the data presented herein, Environmental and Geotechnical Specialists, Inc. requests the opportunity to review the data and make any modifications to the design recommendations which may be appropriate. If you have any questions concerning the information contained in this Report, please do not hesitate to call Myron Hayden, PE or myself (850) 536-8359. Sincerely, Environmental and Geotechnical Specialists, Inc. Florida Certification of Engineering Authorization No. 6222

THIS REPORT HAS BEEN DIGITALLY SIGNED AND SEALED BY: PRINTED COPIES OF THIS DOCUMENT ARE NOT CONSIDERED SIGNED AND SEALED. THE SIGNATURE MUST BE VERIFIED ON THE ELECTRONIC DOCUMENTS Environmental & Geotechnical Specialists, Inc. 104 North Magnolia Drive Tallahassee, FL 32301 Certificate of Authorization: 6222 Joshua M. Jenkins, P.E. No. 77686

TABLES

BORING BORING GROUND

LABEL DEPTH SURFACE

ELEVATION

DEPTH ELEVATION DEPTH ELEVATION

WH-1 28.3 43.0 502058 2041428 25.0 18.0 22.0 21.0

WH-2 30.0 43.0 502075 2041437 > 30.0 < 13.0 22.0 21.0

NOTES: 1. DEPTH MEASURED BELOW EXISTING GROUND SURFACE.

NOTES: 2. ELEVATION REPRESENTS EXISTING GROUND SURFACE DETERMINED FROM PLANS PROVIDED BY GENESIS.

NOTES: 3. BORING LOCATIONS ARE APPROXIMATE AND BASED ON PLANS PROVIDED BY GENESIS.

STATE PLANECOORDINATES

MEASURED GROUNDWATED

(FEET)

PUMP STATION

(FEET)

TABLE 1

(FEET) (FEET) (FEET) (FEET)

ESTIMATED "NORMAL" SEASONAL HIGH GROUNDWATER

(FEET)

SOIL BORING LOCATION AND GROUNDWATER DATA

WOODSIDE HEIGHTS WASTEWATER RETROFITLEON COUNTY, FLORIDA

(FEET)

APPROXIMATE SPT ANGLE OF TOTAL EFFECTIVE UNDRAINED ACTIVE PASSIVE SOILELEVATION 'NCOR' INTERNAL SOIL UNIT SOIL UNIT SHEAR EARTH EARTH DESCRIPTION

VALUE 1 FRICTION WEIGHT WEIGHT STRENGTH PRESSURE PRESSURECOEFFICIENT COEFFICIENT

' c ka kp

(FEET) (DEGREES) (LB/FT3) (LB/FT3) (LB/FT2)

43.0 to 32.0 5 28 100 100 0 0.36 2.77FINE SAND

(SP-SM)

32.0 to 21.0 15 32 115 115 500 0.31 3.19CLAYEY FINE TO

CLAYEY SAND (SC)

21.0 to 13.0 15 0 120 58 1,000 1.00 1.00HIGHLY PLASTIC SANDY SILT (MH)

NOTE: 1. SPT 'NCOR' VALUES HAVE BEEN CORRECTED FOR OVERBURDEN PRESSURE AND HAMMER EFFICIENCY.

PUMP STATIONGEOTECHNICAL DESIGN PARAMETERS

TABLE 2


FIGURES

DRAWN S. SCARPA

CHECKED:

K. SWEENEY, E.I.

Environmental & Geotechnical Specialists, Inc.

104 North Magnolia Drive Tallahassee, Florida 32301

Office #: (850) 386-1253

TITLE:

SITE VICINITY MAP

PUMP STATION WOODSIDE HEIGHTS WASTEWATER RETROFIT

LEON COUNTY, FLORIDA

ENGINEER: J. JENKINS, P.E.

CLIENT: GENESIS GROUP, INC.

PROJ. NO.: 18-139-16-02B

SCALE:

DATE:

APRIL 2017 FIGURE NO.:

1

PROJECT LOCATION

J. JENKINS, P.E.

SR 363 (WOODVILLE HWY)

SR 261 (CAPITAL CIRCLE SE)

PROJECT LOCATION

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5030

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4560

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50 40

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55

DRAWN:

ENGINEER:

CLIENT:

CHECKED:

PROJ. NO.: SCALE: DATE: FIGURE NO.:

TITLE:

Environmental and Geotechnical Specialists, Inc.104 North Magnolia Drive

Tallahassee, Florida 32301Office #: (850) 386-1253Fax #: (850) 385-8050

APRIL 2017 2

USGS TOPOGRAPHIC MAPPUMP STATION


K. SWEENEY, E.I.S. SCARPA

GENESIS GROUP, INC.

18-139-16-02B

0 1,000Feet

200Legend

USGS Elevation Contours (10-Feet)Potential Karst Feature

FIGURE 3A: EXISTING SITE CONDITIONS NEAR PROPOSED

PUMP STATION LOCATION (FACING NORTHEAST)

FIGURE 3B: EXISTING SITE CONDITIONS NEAR PROPOSED

PUMP STATION LOCATION (FACING SOUTHWEST)

APPENDIX A GEOTECHNICAL PLAN SHEET

APPENDIX B SOIL BORING LOGS

0

2.5

5

7.5

10

0

5

10

15

20

25

30

35

MEDIUM DENSEBROWN

FINE SAND

LOOSEBROWN

FINE SAND

VERY LOOSELIGHT BROWN

FINE SAND

LOOSELIGHT BROWN

FINE SAND

MEDIUM DENSEORANGE

CLAYEY FINE SAND

VERY STIFFORANGE AND GRAY

HIGHLY PLASTIC SANDY SILT

STIFFORANGE AND GRAY


HARDGRAY

LIMESTONE

SP-SM

SP-SM

SP-SM

SP-SM

SC

MH

MH

--

-200%=8

-200%=9

-200%=32LL=28PI=15

-200%=75LL=90PI=50

3

4

5

5

5

5

5

4

5

4

15

16

31

40

39

40

41

-- --

--

9

9

5

4

2

3

2

4

6

9

18

12

15

14

13

9

50/3"

--

50/3"

PROJECT: WOODSIDE HEIGHTS PUMP STATION HAMMER TYPE: AUTOMATIC

CLIENT: GENESIS GROUP, INC. NORTHING: 502058

PROJECT NO.: 18-139-16-02B EASTING: 2041428

PROJECT LOCATION: LEON COUNTY, FLORIDA ELEVATION (FEET): 43.0

BORING NO.: WH-1 DATE: 3-13-2017

DRILLER: F. SANCHEZ FLUID LOSS: NONE

DEPTH TO WATER: INITIAL: 25.0' 24 HR: 25.0' CAVING: NONE

NOTES: N/M MEANS NOT MEASURED N/A MEANS NOT AVAILABLE

DE

PT

H (

ME

TE

RS

)

DE

PT

H (

FE

ET

)

SA

MP

LE

SY

MB

OL

DESCRIPTION USCSTEST

RESULTSWc(%)

Wc (%)

10

20

30

40

60

N

N-Value

10

20

30

40

60

80

Th

is i

nfo

rmati

on

pert

ain

s o

nly

to

th

is b

ori

ng

an

d s

ho

uld

no

t b

e i

nte

rpre

ted

as b

ein

g i

nd

icit

ive o

f th

e s

ite.

0

2.5

5

7.5

10

0

5

10

15

20

25

30

35

LOOSEBROWN

FINE SAND

VERY LOOSELIGHT BROWN

FINE SAND

LOOSELIGHT BROWN

FINE SAND

MEDIUM DENSEORANGE

CLAYEY FINE SAND

MEDIUM DENSEORANGE AND GRAY

CLAYEY SAND

VERY STIFFORANGE AND GRAY


SP-SM

SP-SM

SP-SM

SC

SC

MH

-200%=7

-200%=26LL=24PI=11

-200%=49LL=38PI=22

-200%=70LL=84PI=46

3

5

5

5

5

5

5

4

4

5

4

15

16

14

17

16

38

35

--

6

5

4

2

3

2

4

6

6

8

10

13

17

13

20

19

19

--

PROJECT: WOODSIDE HEIGHTS PUMP STATION HAMMER TYPE: AUTOMATIC

CLIENT: GENESIS GROUP, INC. NORTHING: 502075

PROJECT NO.: 18-139-16-02B EASTING: 2041437

PROJECT LOCATION: LEON COUNTY, FLORIDA ELEVATION (FEET): 43.0

BORING NO.: WH-2 DATE: 3-15-2017

DRILLER: F. SANCHEZ FLUID LOSS: NONE

DEPTH TO WATER: INITIAL: > 30.0' 24 HR: N/M CAVING: NONE

NOTES: N/M MEANS NOT MEASURED N/A MEANS NOT AVAILABLE

DE

PT

H (

ME

TE

RS

)

DE

PT

H (

FE

ET

)

SA

MP

LE

SY

MB

OL

DESCRIPTION USCSTEST

RESULTSWc(%)

Wc (%)

10

20

30

40

60

N

N-Value

10

20

30

40

60

80

Th

is i

nfo

rmati

on

pert

ain

s o

nly

to

th

is b

ori

ng

an

d s

ho

uld

no

t b

e i

nte

rpre

ted

as b

ein

g i

nd

icit

ive o

f th

e s

ite.

APPENDIX C SOIL CLASSIFICATION DATA

0.0-0.5 3 -- SP-SM MEDIUM DENSEBROWN

FINE SAND1.0-1.5 4 100 100 99 88 45 23 8 9 SP-SM MEDIUM DENSE

BROWNFINE SAND

2.0-2.5 5 9 SP-SM MEDIUM DENSEBROWN

FINE SAND3.0-3.5 5 5 SP-SM LOOSE

BROWNFINE SAND

4.0-4.5 5 4 SP-SM LOOSEBROWN

FINE SAND5.0-5.5 5 2 SP-SM VERY LOOSE

LIGHT BROWNFINE SAND

6.0-6.5 5 3 SP-SM VERY LOOSELIGHT BROWN



7.5-9.0 5 100 100 100 88 38 21 9 4 SP-SM LOOSELIGHT BROWN



10.5-12.0 15 9 SC MEDIUM DENSEORANGE

CLAYEY FINE SAND12.5-14.0 16 100 100 100 96 74 55 32 28 15 18 SC MEDIUM DENSE

ORANGECLAYEY FINE SAND

15.0-16.5 31 12 MH VERY STIFFORANGE AND GRAY


SOIL CLASSIFICATION DATA

Project: WOODSIDE HEIGHTS PUMP STATION

Client: GENESIS GROUP, INC. Project No.: 18-139-16-02B

Boring: WH-1 Location: LEON COUNTY, FLORIDA

DEPTH(FEET)

Wc(%)

-4(%)

-10(%)

-20(%)

-40(%)

-60(%)

-100(%)

-200(%)

LL PIOrg.(%)

NValue

USCS Description

HIGHLY PLASTIC SANDY SILT17.5-19.0 40 100 100 100 98 94 89 75 90 50 15 MH VERY STIFF

ORANGE AND GRAYHIGHLY PLASTIC SANDY SILT

20.0-21.5 39 14 MH VERY STIFFORANGE AND GRAY

HIGHLY PLASTIC SANDY SILT22.5-24.0 40 13 MH VERY STIFF


25.0-26.5 41 9 MH STIFFORANGE AND GRAY

HIGHLY PLASTIC SANDY SILT28.0-28.3 -- 50/3" -- HARD

GRAYLIMESTONE






DEPTH(FEET)

Wc(%)

-4(%)

-10(%)

-20(%)

-40(%)

-60(%)

-100(%)

-200(%)

LL PIOrg.(%)

NValue

USCS Description

0.0-0.5 3 -- SP-SM LOOSEBROWN

FINE SAND1.0-1.5 5 100 100 100 87 43 21 7 6 SP-SM LOOSE

BROWNFINE SAND

2.0-2.5 5 5 SP-SM LOOSEBROWN


BROWNFINE SAND







7.5-9.0 4 6 SP-SM LOOSELIGHT BROWN



10.5-12.0 4 8 SP-SM LOOSELIGHT BROWN

FINE SAND12.5-14.0 15 100 100 100 95 62 42 26 24 11 10 SC MEDIUM DENSE


15.0-16.5 16 13 SC MEDIUM DENSEORANGE






DEPTH(FEET)

Wc(%)

-4(%)

-10(%)

-20(%)

-40(%)

-60(%)

-100(%)

-200(%)

LL PIOrg.(%)

NValue

USCS Description

CLAYEY FINE SAND17.5-19.0 14 17 SC MEDIUM DENSE


20.0-21.5 17 100 100 100 97 84 76 49 38 22 13 SC MEDIUM DENSEORANGE AND GRAY

CLAYEY SAND22.5-24.0 16 20 SC MEDIUM DENSE

ORANGE AND GRAYCLAYEY SAND

25.0-26.5 38 100 100 99 98 97 94 70 84 46 19 MH VERY STIFFORANGE AND GRAY

HIGHLY PLASTIC SANDY SILT28.0-30.0 35 19 MH VERY STIFF







DEPTH(FEET)

Wc(%)

-4(%)

-10(%)

-20(%)

-40(%)

-60(%)

-100(%)

-200(%)

LL PIOrg.(%)

NValue

USCS Description