Appendix_6_-_Geosyntec_Geotech_Eval_Tech_Memo.pdf

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Tech Memo 15APR20 mwe

Technical Memorandum Date: 17 April 2020

To: Josie Benwell, M.S., ENV SP - Project Coordinator

Stormwater and Vegetation Division - Pinellas County Public Works

From: Daniel Montiel, PhD and Todd D. Anderson, PE, Geosyntec

Subject: Geotechnical Evaluation

M10 Starkey SMF Retrofit Preliminary Design Starkey Road and 126th Avenue North Geosyntec Project: FW3498

INTRODUCTION

The purpose of this memorandum is to provide a summary of the geotechnical work items completed by Geosyntec Consultants, Inc. (Geosyntec) in support of the M10 Starkey Stormwater Management Facility (SMF) Retrofit Preliminary Design per the executed work order dated December 27, 2018 and the Notice to Proceed issued on January 4, 2019. Geosyntec Consultants was tasked by the Pinellas County Stormwater and Vegetation Division to perform this work. The work was performed under the Pinellas County Professional Engineering and Environmental Consulting Services Contract 156-0095-CN.

The scope of work to perform this geotechnical evaluation consisted of the following:

• A review of the available information, including:

o The United States Department of Agriculture (USDA) Web Soil Survey (WSS) for the site soils and water condition, and o URS plans for Starkey Road Pond 6.

• Performing a limited field and laboratory investigation of the site; and

• Providing a geotechnical evaluation and recommendations for site development.

PROJECT BACKGROUND

The former historical drainage ditch was previously expanded and currently serves as the M10 Starkey SMF, a wetland mitigation area to the upstream contributing areas. The purpose of this design is to enhance the existing M10 Starkey SMF (Site) by providing additional residence time and storage that will improve water quality treatment, along with maintaining existing upstream flooding level of service. The increased residence time will be achieved in through combination http://www.geosyntec.com/

Geotechnical Evaluation, M10 Starkey SMF 17 April 2020 of adding a downstream weir to detain stormwater runoff and by providing additional upstream storage at the upper reaches of the ditch segment though excavation of a County owned parcel.

The Site is located within Section 11 of Township 30 South, Range 15 East. More specifically, the Site is located northwest of the intersection of Starkey Road and 126th Avenue North, partially within unincorporated Pinellas County and the City of Largo (Figure 1). The Site lies within the jurisdiction of the Southwest Florida Water Management District (SWFWMD), within County Commission District 2, within the Starkey Road Basin.

REVIEW OF AVAILABLE INFORMATION

USDA Web Soil Survey The USDA Web Soil Survey (WSS) was utilized to compile soil parameters of geotechnical interest for the viability construction of a SMF at the proposed Site. Parameters of interest analyzed include soil classification; percent sand, silt and clay; flooding frequency and depth to groundwater; erosion potential (K factor); soil hydraulic conductivity; and surface water management limitation to system installations. Relevant excerpts from the WSS are included in Appendix A.

Based on the WSS, the proposed Site area is classified as Myakka soils and Urban land taxonomically described as sandy, siliceous, hyperthermic Aeric Alaquods, composed of well sorted clean sands with between 95.3 and 97.4% sand, less than 0.9% silt, and less than 1.7% clay (Appendix A).

The soil erosion susceptibility factor K rating indicates that the soil erodibility by water is very low in the Site with a rate of 0.02 (in a scale of 0.02-0.69). This estimate is based primarily on percentage of silt, sand, and organic matter and on soil structure and saturated hydraulic conductivity (Ksat). The soil Ksat rating in the Site is approximately 23 ft/day based on WSS soil field observations such as structure, porosity, and texture (Appendix A).

The ratings for Surface Water Management, based on the soil properties that affect the capacity of the soil to convey surface water, indicate that no limitation exists for the construction of a SMF (Appendix A).

The WSS also provides information about potential flooding and depth to water table. The flooding frequency rate in the Site shows that flooding is not probable, the chance of flooding is nearly 0% during any year and occurs less than once in 500 years. Depth to seasonal high water table (SHWT or SHGW) is shown to be between 0.8 and 1.6 ft below ground surface (bgs) (Appendix A).

URS Starkey Road Plans Geosyntec reviewed the Pinellas County provided URS Starkey Road – From Bryan Dairy Road to Ulmerton Road Plans (URS 2011). This plan set includes a soil boring and design for Pond 6C, which is located south of the Site, across the channel. The WSS indicated the same soil type (Myakka soils and Urban land) for the Site and across the canal at Pond 6C. Based on this, we believe the use of the Starkey Road plans is appropriate when evaluating the soils and design components for the SMF. Geosyntec has included two pages from the plan set that show Pond 6C (Appendix B).

The soil boring P6C-1 was advanced to a depth of 15 ft-bgs in July of 2006 within Pond 6C. The boring indicated a surficial soil consisting of sands with trace amounts of silt and shell to a depth of approximately 6 ft-bgs and below the surficial layer silty sand was encountered to the boring termination depth. The measured depth of water was 7 ft-bgs and the SHGW was set at an elevation of 12.5 ft-NAVD 88 (5.5 ft-bgs). The plans also show a SHWT elevation of 11.8 ft NAVD 88 at the canal.

The pond was designed with a 25-foot wide, 9-inch thick stabilized (LBR 40) top of bank with a slope of 1:25 (Vertical:Horizontal) and 1:4 side slopes down to the bottom of the pond. The top of bank and side slopes were to be vegetated with sod to the pond weir elevation of 12.7 ft-NAVD 88.

SITE INVESTIGATION

Field Soil Characterization On 25 October 2019, Geosyntec advanced three hand auger borings on the Site at the locations shown on Figure 1. The borings were advancement to approximately 7 ft BLS. Soil from each individual boring was composited into single composite samples by location (P-1 through P-3).

Geosyntec field staff recorded apparent depth to water from soil moisture content and obtained photographic record of each sample at a 1-ft interval (Appendix C). Soil cuttings generated during hand auger sampling activities were used to backfill the respective boreholes of origin.

Boring location P-1 was composed of tan to dark brown, silty fine sand with trace amounts of clay from 0 to 7 ft-bgs. Boring location P-2 was composed of tan to dark brown, fine sand with trace amounts of clay from 0 to 7 f-bgs. Boring location P-3 was comprised of brown sand from 0 ft BLS to 4 ft-bgs and silty sand with shell fragments and trace amounts of clay from 4 ft-bgs to 7 ft-bgs. In all three soil sample locations, the apparent depth to water was approximately 5 ft BLS based on the observed soil moisture.

Laboratory Soil Particle Size and Organic Content Soil samples were sent to Eurofins TestAmerica, Inc (Eurofins) in Tampa, Florida for percent organic content laboratory analysis and particle size characterization (along with analytical testing not discussed herein). Soil samples were analyzed for percent organic content following ASTM Standard Test Methods for Determining the Water (Moisture) Content, Ash Content, and Organic Material of Peat and Other Organic Soils D422. Soil grain size characterization was analyzed following the American Society for Testing and Materials (ASTM) Standard Test Method for Particle-Size Analysis of Soils D2974. The portion of the Eurofins report that includes percent organics and particle size distribution (with curves) is included in Appendix D.

The total organic matter content in each of the composite samples was less than 1% (P-1 contained 0.72%, P-2 contained 0.66%, and P-3 contained 0.69%). Composite soil sample P-1 was composed of 79.3% sand and 20.7% fines (16.1% silt and 4.6% clay. Composite soil sample P-2 was composed of 93.7% sand and 6.3% fines (1.8% silt and 4.5% clay). Composite soil sample P-3 was composed of 76.7% sand and 21.4% fines (16.0% silt and 5.4% clay).

EVALUATION AND RECOMMENDATIONS

Evaluation Based on the review of the available information and the site investigation, the soil present at the Site are favorable for construction of a SMF. The WSS, boring performed for Starkey Road Pond 6C, and Geosyntec’s Site investigation all indicate sandy surficial soils that have more silt with depth. The WSS states that the site is rated as “Not limited” in regards to using the site for a surface water management system which indicates that soil “has features that are very favorable for the specified use” and that “good performance and very low maintenance can be expected.”

The WSS also states that the erodibility of Site soils with water is very low. Also, excavation and grading of sandy soils is typical for the area and should result in the use of standard construction techniques.

The WSS indicates a SHWT between 0.8 and 1.6 ft-bgs which could be a limitation for use of the site as a SMF. However, WSS show the same soils across the canal at the Pond 6C site but the accepted value is 5.5 ft-bgs. This could be due to the proximity of the pond to the canal and pond to the east that could draw down the local water table. Dewatering of the site is not anticipated due to the depth to measured groundwater. However, should dewatering be required it should be able to be accomplished with standard system using sumps and pumps to lower the ground water level.

The soil profile shown for the Starkey Road pond boring P6C-1 was similar to the soil profiles for the borings at the Site and as stated above, the WSS also indicates the same soil type at both locations. Therefore, we can expect design properties used for Pond 6C to be applicable for the design of the SMF. The design of Pond 6C shows 1:4 side slopes with sod covered sides and a depth of over 14 feet. That slope is typical for a SMF and allows for ease of maintenance

(mowing). The depth of Pond 6C is well below the water table and includes a littoral shelf below the SHWT set in the canal.

Recommendations Design Recommendations

Geosyntec recommends that the SMF be designed with 1:4 side slopes or flatter. All slopes should be vegetated with sod to prevent erosion. The sod should cover the top of bank down to the existing ground water table. The area disturbed during construction around the SMF should also be vegetated with sod or planted with seed to reduce erosion. We understand the SMF will likely function as a wet detention design so the WSS Ksat value of approximately 23 ft/day can be used to design the SMF. We recommend that soil samples be collected prior to construction to establish compaction standards for the side slopes and any necessary fill placement. We recommend using the seasonal high water table elevation of 11.8 ft NAVD 88, as included in the Starkey Road plans at the canal. Areas of high flow in the SMF should be protected with a designed rip rap apron or a revetment system to prevent erosion.

Construction Recommendations

Our recommendations regarding general site preparation of the SMF area include:

• Establish proper erosion control procedures such as silt fencing and a floating turbidity barrier;

• Provide for positive site drainage during construction;

• Standard clearing, grubbing, and topsoil stripping (for reuse, if possible) of the Site;

• Perform dewatering, if required;

• Excavate, grade, and compact the slopes of the SMF;

o Compaction efforts should be 95% of the soils standard Proctor maximum dry density as determined by ASTM Specification D-1557 for each lift of fill placed, o Fill should be placed in lifts no thicker than 12 inches.

o The contractor should be aware that slope height, slope inclination, and excavation depths should not exceed those specified in local, state, or federal safety regulations; e.g., OSHA Health and Safety Standards for Excavations, 29 CFR Part 1926.

o Site soils are primarily sand with varying amounts of silt. We anticipate that OSHA will classify these materials as Type C. OSHA recommends a maximum temporary slope inclination of 1.5 horizontal to 1 vertical for this soil type. Soils encountered in the construction excavations may vary significantly across the site.

Our soil classifications are based on our borings, the WSS, and the Starkey Pond boring.

• Install permanent erosion control features such as rip rap, if needed; and

• Sod the SMF and surrounding area to prevent erosion.

The recommendations presented in this report were prepared in accordance with generally accepted geotechnical engineering principles and practices. Recommendations are limited in that they were developed from limited field and laboratory testing and available information. Borings depict subsurface conditions at the specific locations documented in this report. Soil conditions at other locations on this Site may differ from those encountered in the test borings. Geosyntec Consultants is not responsible for the independent conclusions, opinions or recommendations made by others based on the field exploration and laboratory test data presented in this report.

REFERENCES

United States Department of Agriculture, Natural Resources Conservation Service. Web Soil Survey. Retrieved April 3, 2020, from http://websoilsurvey.nrcs.usda.gov/

URS Corporation, 2011. Starkey Road from Bryan Dairy Road to Ulmerton Road. Project No.

922252. Pinellas County Engineering Department.

This item has been electronically signed and sealed by Todd D. Anderson, PE on 17 April 2020 using a digital signature.

Printed copies of this document are not considered signed and sealed and the SHA authentication code must be verified on any electronic copies.

FIGURE

126TH AVE N

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141414

14 14 14 14 14 14 14 14 14 Sources:

Infrastructure: Pinellas County, 2018 Parcels, Roads: Pinellas County, 2010 Contours: Pinellas County, 2017 Aerial Imagery: ESRI

0 15075 Feet

Legend

Proposed SMF Site 2-foot Contour Parcel Drainage Easement Right-of-Way

!. Control Structure !. Inlet

Culvert

Site Map

M10 Starkey SMF Retrofit

Figure

DMontiel Oval

DMontiel Oval

DMontiel Oval

DMontiel Typewritten Text P-1

DMontiel Typewritten Text P-2

DMontiel Typewritten Text P-3

DMontiel Oval

DMontiel Typewritten Text Soil Sample Location

DMontiel Polygon

DMontiel Rectangle

Appendix A

Web Soi l Survey Informat ion

Unified Soil Classification (Surface)—Pinellas County, Florida

Natural Resources Conservation Service

Web Soil Survey National Cooperative Soil Survey

4/3/2020

326200 326300 326400 326500 326600 326700 326800 326900 327000 327100

326200 326300 326400 326500 326600 326700 326800 326900 327000 327100

27° 53' 28'' N

5'

9' ' W

27° 53' 28'' N

5'

0' ' W

27° 53' 5'' N

5'

9' ' W

27° 53' 5'' N

5'

0' ' W

N

Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 17N WGS84 0 200 400 800 1200

Feet 0 50 100 200 300

Meters Map Scale: 1:4,890 if printed on A landscape (11" x 8.5") sheet.

Soil Map may not be valid at this scale.

MAP LEGEND

Area of Interest (AOI)

Area of Interest (AOI)

Soils Soil Rating Polygons

CH

CL

CL-A (proposed)

CL-K (proposed)

CL-ML

CL-O (proposed)

CL-T (proposed)

GC

GC-GM

GM

GP

GP-GC

GP-GM

GW

GW-GC

GW-GM

MH

MH-A (proposed)

MH-K (proposed)

MH-O (proposed)

MH-T (proposed)

ML

ML-A (proposed)

ML-K (proposed)

ML-O (proposed)

ML-T (proposed)

OH

OH-T (proposed)

OL

PT

SC

SC-SM

SM

SP

SP-SC

SP-SM

SW

SW-SC

SW-SM

Not rated or not available

Soil Rating Lines

CH

CL

CL-A (proposed)

CL-K (proposed)

CL-ML

CL-O (proposed)

CL-T (proposed)

GC

GC-GM

GM

GP

GP-GC

GP-GM

GW

GW-GC

GW-GM

MH

MH-A (proposed)

MH-K (proposed)

MH-O (proposed)

MH-T (proposed)

ML

ML-A (proposed)

ML-K (proposed)

ML-O (proposed)

ML-T (proposed)

OH

OH-T (proposed)

OL

PT

SC

SC-SM

SM

SP

SP-SC

SP-SM

SW

SW-SC

SW-SM

Not rated or not available

Soil Rating Points

CH

CL

CL-A (proposed)

CL-K (proposed)

CL-ML

CL-O (proposed)

CL-T (proposed)

GC

GC-GM

GM

GP

GP-GC

GP-GM

GW

GW-GC

GW-GM

MH

MH-A (proposed)

MH-K (proposed)

MH-O (proposed)

MH-T (proposed)

ML

ML-A (proposed)

ML-K (proposed)

ML-O (proposed)

ML-T (proposed)

OH

OH-T (proposed)

OL

PT

SC

SC-SM

SM

SP

SP-SC

SP-SM

SW

SW-SC

SW-SM

Not rated or not available

Water Features Streams and Canals

Transportation Rails

Unified Soil Classification (Surface)—Pinellas County, Florida

Natural Resources Conservation Service

Web Soil Survey National Cooperative Soil Survey

4/3/2020

MAP INFORMATION

Interstate Highways

US Routes

Major Roads

Local Roads

Background Aerial Photography

The soil surveys that comprise your AOI were mapped at 1:24,000.

Warning: Soil Map may not be valid at this scale.

Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale.

Please rely on the bar scale on each map sheet for map measurements.

Source of Map: Natural Resources Conservation Service Web Soil Survey URL:

Coordinate System: Web Mercator (EPSG:3857)

Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required.

This product is generated from the USDA-NRCS certified data as of the version date(s) listed below.

Soil Survey Area: Pinellas County, Florida Survey Area Data: Version 16, Sep 17, 2019

Soil map units are labeled (as space allows) for map scales 1:50,000 or larger.

Date(s) aerial images were photographed: Dec 29, 2010—Feb 28, 2014

The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident.

Unified Soil Classification (Surface)—Pinellas County, Florida

Natural Resources Conservation Service

Web Soil Survey National Cooperative Soil Survey

Unified Soil Classification (Surface)

Map unit symbol Map unit name Rating Acres in AOI Percent of AOI

15 Manatee loamy fine sand, frequently ponded, 0 to 1 percent slopes

SM 4.1 3.5%

16 Matlacha and St.

Augustine soils and Urban land

SP 0.0 0.0%

17 Myakka soils and Urban land

SP 109.1 92.9%

31 Wabasso soils and Urban land

SP 4.3 3.7%

Totals for Area of Interest 117.5 100.0%

Description

The Unified soil classification system classifies mineral and organic mineral soils for engineering purposes on the basis of particle-size characteristics, liquid limit, and plasticity index. It identifies three major soil divisions: (i) coarse-grained soils having less than 50 percent, by weight, particles smaller than 0.074 mm in diameter; (ii) fine-grained soils having 50 percent or more, by weight, particles smaller than 0.074 mm in diameter; and (iii) highly organic soils that demonstrate certain organic characteristics. These divisions are further subdivided into a total of 15 basic soil groups. The major soil divisions and basic soil groups are determined on the basis of estimated or measured values for grain-size distribution and Atterberg limits. ASTM D 2487 shows the criteria chart used for classifying soil in the Unified system and the 15 basic soil groups of the system and the plasticity chart for the Unified system.

The various groupings of this classification correlate in a general way with the engineering behavior of soils. This correlation provides a useful first step in any field or laboratory investigation for engineering purposes. It can serve to make some general interpretations relating to probable performance of the soil for engineering uses.

For each soil horizon in the database one or more Unified soil classifications may be listed. One is marked as the representative or most commonly occurring. The representative classification is shown here for the surface layer of the soil.

Rating Options

Aggregation Method: Dominant Condition

Component Percent Cutoff: None Specified

Tie-break Rule: Lower

Unified Soil Classification (Surface)—Pinellas County, Florida

Natural Resources Conservation Service

Web Soil Survey National Cooperative Soil Survey

Layer Options (Horizon Aggregation Method): Surface Layer (Not applicable)

Unified Soil Classification (Surface)—Pinellas County, Florida

Natural Resources Conservation Service

Web Soil Survey National Cooperative Soil Survey

Soil Taxonomy Classification—Pinellas County, Florida

Conservation Service

Web Soil Survey National Cooperative Soil Survey

4/3/2020

326200 326300 326400 326500 326600 326700 326800 326900 327000 327100

326200 326300 326400 326500 326600 326700 326800 326900 327000 327100

27° 53' 28'' N

5'

9' ' W

27° 53' 28'' N

5'

0' ' W

27° 53' 5'' N

5'

9' ' W

27° 53' 5'' N

5'

0' ' W

N

Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 17N WGS84 0 200 400 800 1200

Feet 0 50 100 200 300

Meters

MAP LEGEND MAP INFORMATION

Area of Interest (AOI)

Soils Soil Rating Polygons

Coarse-loamy, siliceous, superactive, hyperthermic Typic Argiaquolls Sandy over loamy, siliceous, active, hyperthermic Alfic Alaquods Sandy, siliceous, hyperthermic Aeric Alaquods Sandy, siliceous, hyperthermic Alfic Udarents Not rated or not available

Soil Rating Lines Coarse-loamy, siliceous, superactive, hyperthermic Typic Argiaquolls Sandy over loamy, siliceous, active, hyperthermic Alfic Alaquods Sandy, siliceous, hyperthermic Aeric Alaquods Sandy, siliceous, hyperthermic Alfic Udarents

Not rated or not available

Soil Rating Points Coarse-loamy, siliceous, superactive, hyperthermic Typic Argiaquolls Sandy over loamy, siliceous, active, hyperthermic Alfic Alaquods Sandy, siliceous, hyperthermic Aeric Alaquods Sandy, siliceous, hyperthermic Alfic Udarents Not rated or not available

Water Features Streams and Canals

Transportation Rails

Interstate Highways

US Routes

Major Roads

Local Roads

Background Aerial Photography

The soil surveys that comprise your AOI were mapped at 1:24,000.

Warning: Soil Map may not be valid at this scale.

Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale.

Please rely on the bar scale on each map sheet for map measurements.

Source of Map: Natural Resources Conservation Service Web Soil Survey URL:

Coordinate System: Web Mercator (EPSG:3857)

Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required.

This product is generated from the USDA-NRCS certified data as of the version date(s) listed below.

Soil Survey Area: Pinellas County, Florida Survey Area Data: Version 16, Sep 17, 2019

Soil map units are labeled (as space allows) for map scales 1:50,000 or larger.

Date(s) aerial images were photographed: Dec 29, 2010—Feb 28, 2014

The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident.

Soil Taxonomy Classification—Pinellas County, Florida

Natural Resources Conservation Service

Web Soil Survey National Cooperative Soil Survey

Soil Taxonomy Classification

15 Manatee loamy fine sand, frequently ponded, 0 to 1 percent slopes

Coarse-loamy, siliceous, superactive, hyperthermic Typic Argiaquolls

4.1 3.5%

16 Matlacha and St.

Augustine soils and Urban land

Sandy, siliceous, hyperthermic Alfic Udarents

0.0 0.0%

17 Myakka soils and Urban land

Sandy, siliceous, hyperthermic Aeric Alaquods

109.1 92.9%

31 Wabasso soils and Urban land

Sandy over loamy, siliceous, active, hyperthermic Alfic Alaquods

4.3 3.7%

Totals for Area of Interest 117.5 100.0%

Soil Taxonomy Classification—Pinellas County, Florida

Natural Resources Conservation Service

Web Soil Survey National Cooperative Soil Survey

Description

This rating presents the taxonomic classification based on Soil Taxonomy.

The system of soil classification used by the National Cooperative Soil Survey has six categories (Soil Survey Staff, 1999 and 2003). Beginning with the broadest, these categories are the order, suborder, great group, subgroup, family, and series. Classification is based on soil properties observed in the field or inferred from those observations or from laboratory measurements. This table shows the classification of the soils in the survey area. The categories are defined in the following paragraphs.

ORDER. Twelve soil orders are recognized. The differences among orders reflect the dominant soil-forming processes and the degree of soil formation. Each order is identified by a word ending in sol. An example is Alfisols.

SUBORDER. Each order is divided into suborders primarily on the basis of properties that influence soil genesis and are important to plant growth or properties that reflect the most important variables within the orders. The last syllable in the name of a suborder indicates the order. An example is Udalfs (Ud, meaning humid, plus alfs, from Alfisols).

GREAT GROUP. Each suborder is divided into great groups on the basis of close similarities in kind, arrangement, and degree of development of pedogenic horizons; soil moisture and temperature regimes; type of saturation; and base status. Each great group is identified by the name of a suborder and by a prefix that indicates a property of the soil. An example is Hapludalfs (Hapl, meaning minimal horizonation, plus udalfs, the suborder of the Alfisols that has a udic moisture regime).

SUBGROUP. Each great group has a typic subgroup. Other subgroups are intergrades or extragrades. The typic subgroup is the central concept of the great group; it is not necessarily the most extensive. Intergrades are transitions to other orders, suborders, or great groups. Extragrades have some properties that are not representative of the great group but do not indicate transitions to any other taxonomic class. Each subgroup is identified by one or more adjectives preceding the name of the great group. The adjective Typic identifies the subgroup that typifies the great group. An example is Typic Hapludalfs.

FAMILY. Families are established within a subgroup on the basis of physical and chemical properties and other characteristics that affect management. Generally, the properties are those of horizons below plow depth where there is much biological activity. Among the properties and characteristics considered are particle-size class, mineralogy class, cation-exchange activity class, soil temperature regime, soil depth, and reaction class. A family name consists of the name of a subgroup preceded by terms that indicate soil properties. An example is fine-loamy, mixed, active, mesic Typic Hapludalfs.

SERIES. The series consists of soils within a family that have horizons similar in color, texture, structure, reaction, consistence, mineral and chemical composition, and arrangement in the profile.

Soil Taxonomy Classification—Pinellas County, Florida

Natural Resources Conservation Service

Web Soil Survey National Cooperative Soil Survey

References:

Soil Survey Staff. 1999. Soil taxonomy: A basic system of soil classification for making and interpreting soil surveys. 2nd edition. Natural Resources Conservation Service. U.S. Department of Agriculture Handbook 436.

Soil Survey Staff. 2006. Keys to soil taxonomy. 10th edition. U.S. Department of Agriculture, Natural Resources Conservation Service. (The soils in a given survey area may have been classified according to earlier editions of this publication.)

Rating Options

Aggregation Method: Dominant Condition

Component Percent Cutoff: None Specified

Tie-break Rule: Lower

Soil Taxonomy Classification—Pinellas County, Florida

Natural Resources Conservation Service

Web Soil Survey National Cooperative Soil Survey

Percent Sand—Pinellas County, Florida

Conservation Service

Web Soil Survey National Cooperative Soil Survey

4/3/2020

326200 326300 326400 326500 326600 326700 326800 326900 327000 327100

326200 326300 326400 326500 326600 326700 326800 326900 327000 327100

27° 53' 28'' N

5'

9' ' W

27° 53' 28'' N

5'

0' ' W

27° 53' 5'' N

5'

9' ' W

27° 53' 5'' N

5'

0' ' W

N

Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 17N WGS84 0 200 400 800 1200

Feet 0 50 100 200 300

Meters

Area of Interest (AOI)

Soils Soil Rating Polygons

<= 72.1

> 72.1 and <= 88.2

> 88.2 and <= 95.3

> 95.3 and <= 97.4

Not rated or not available

Soil Rating Lines <= 72.1

> 72.1 and <= 88.2

> 88.2 and <= 95.3

> 95.3 and <= 97.4

Not rated or not available

Soil Rating Points <= 72.1

> 72.1 and <= 88.2

> 88.2 and <= 95.3

> 95.3 and <= 97.4

Not rated or not available

Water Features Streams and Canals

Transportation Rails

Interstate Highways

US Routes

Major Roads

Local Roads

Background Aerial Photography

The soil surveys that comprise your AOI were mapped at 1:24,000.

Warning: Soil Map may not be valid at this scale.

Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale.

Please rely on the bar scale on each map sheet for map measurements.

Source of Map: Natural Resources Conservation Service Web Soil Survey URL:

Coordinate System: Web Mercator (EPSG:3857)

Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required.

This product is generated from the USDA-NRCS certified data as of the version date(s) listed below.

Soil Survey Area: Pinellas County, Florida Survey Area Data: Version 16, Sep 17, 2019

Soil map units are labeled (as space allows) for map scales 1:50,000 or larger.

Date(s) aerial images were photographed: Dec 29, 2010—Feb 28, 2014

The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident.

Percent Sand—Pinellas County, Florida

Natural Resources Conservation Service

Web Soil Survey National Cooperative Soil Survey

Percent Sand

Map unit symbol Map unit name Rating (percent) Acres in AOI Percent of AOI

15 Manatee loamy fine sand, frequently ponded, 0 to 1 percent slopes

72.1 4.1 3.5%

16 Matlacha and St.

Augustine soils and Urban land

95.3 0.0 0.0%

17 Myakka soils and Urban land

97.4 109.1 92.9%

31 Wabasso soils and Urban land

88.2 4.3 3.7%

Totals for Area of Interest 117.5 100.0%

Description

Sand as a soil separate consists of mineral soil particles that are 0.05 millimeter to 2 millimeters in diameter. In the database, the estimated sand content of each soil layer is given as a percentage, by weight, of the soil material that is less than 2 millimeters in diameter. The content of sand, silt, and clay affects the physical behavior of a soil. Particle size is important for engineering and agronomic interpretations, for determination of soil hydrologic qualities, and for soil classification.

For each soil layer, this attribute is actually recorded as three separate values in the database. A low value and a high value indicate the range of this attribute for the soil component. A "representative" value indicates the expected value of this attribute for the component. For this soil property, only the representative value is used.

Rating Options

Units of Measure: percent

Aggregation Method: Dominant Component

Component Percent Cutoff: None Specified

Tie-break Rule: Higher

Interpret Nulls as Zero: No

Layer Options (Horizon Aggregation Method): All Layers (Weighted Average)

Percent Sand—Pinellas County, Florida

Natural Resources Conservation Service

Web Soil Survey National Cooperative Soil Survey

Percent Silt—Pinellas County, Florida

Conservation Service

Web Soil Survey National Cooperative Soil Survey

4/3/2020

326200 326300 326400 326500 326600 326700 326800 326900 327000 327100

326200 326300 326400 326500 326600 326700 326800 326900 327000 327100

27° 53' 28'' N

5'

9' ' W

27° 53' 28'' N

5'

0' ' W

27° 53' 5'' N

5'

9' ' W

27° 53' 5'' N

5'

0' ' W

N

Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 17N WGS84 0 200 400 800 1200

Feet 0 50 100 200 300

Meters

Area of Interest (AOI)

Soils Soil Rating Polygons

<= 0.9

> 0.9 and <= 3.8

> 3.8 and <= 4.0

> 4.0 and <= 17.1

Not rated or not available

Soil Rating Lines <= 0.9

> 0.9 and <= 3.8

> 3.8 and <= 4.0

> 4.0 and <= 17.1

Not rated or not available

Soil Rating Points <= 0.9

> 0.9 and <= 3.8

> 3.8 and <= 4.0

> 4.0 and <= 17.1

Not rated or not available

Water Features Streams and Canals

Transportation Rails

Interstate Highways

US Routes

Major Roads

Local Roads

Background Aerial Photography

The soil surveys that comprise your AOI were mapped at 1:24,000.

Warning: Soil Map may not be valid at this scale.

Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale.

Please rely on the bar scale on each map sheet for map measurements.

Source of Map: Natural Resources Conservation Service Web Soil Survey URL:

Coordinate System: Web Mercator (EPSG:3857)

Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required.

This product is generated from the USDA-NRCS certified data as of the version date(s) listed below.

Soil Survey Area: Pinellas County, Florida Survey Area Data: Version 16, Sep 17, 2019

Soil map units are labeled (as space allows) for map scales 1:50,000 or larger.

Date(s) aerial images were photographed: Dec 29, 2010—Feb 28, 2014

The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident.

Percent Silt—Pinellas County, Florida

Natural Resources Conservation Service

Web Soil Survey National Cooperative Soil Survey

Percent Silt

15 Manatee loamy fine sand, frequently ponded, 0 to 1 percent slopes

17.1 4.1 3.5%

16 Matlacha and St.

Augustine soils and Urban land

3.8 0.0 0.0%

17 Myakka soils and Urban land

0.9 109.1 92.9%

31 Wabasso soils and Urban land

4.0 4.3 3.7%

Totals for Area of Interest 117.5 100.0%

Description

Silt as a soil separate consists of mineral soil particles that are 0.002 to 0.05 millimeter in diameter. In the database, the estimated silt content of each soil layer is given as a percentage, by weight, of the soil material that is less than 2 millimeters in diameter.

The content of sand, silt, and clay affects the physical behavior of a soil. Particle size is important for engineering and agronomic interpretations, for determination of soil hydrologic qualities, and for soil classification

For each soil layer, this attribute is actually recorded as three separate values in the database. A low value and a high value indicate the range of this attribute for the soil component. A "representative" value indicates the expected value of this attribute for the component. For this soil property, only the representative value is used.

Rating Options

Units of Measure: percent

Aggregation Method: Dominant Component

Component Percent Cutoff: None Specified

Tie-break Rule: Higher

Interpret Nulls as Zero: No

Layer Options (Horizon Aggregation Method): All Layers (Weighted Average)

Percent Silt—Pinellas County, Florida

Natural Resources Conservation Service

Web Soil Survey National Cooperative Soil Survey

Percent Clay—Pinellas County, Florida

Conservation Service

Web Soil Survey National Cooperative Soil Survey

4/3/2020

326200 326300 326400 326500 326600 326700 326800 326900 327000 327100

326200 326300 326400 326500 326600 326700 326800 326900 327000 327100

27° 53' 28'' N

5'

9' ' W

27° 53' 28'' N

5'

0' ' W

27° 53' 5'' N

5'

9' ' W

27° 53' 5'' N

5'

0' ' W

N

Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 17N WGS84 0 200 400 800 1200

Feet 0 50 100 200 300

Meters

Area of Interest (AOI)

Soils Soil Rating Polygons

<= 1.7

> 1.7 and <= 6.4

> 6.4 and <= 7.8

> 7.8 and <= 10.7

Not rated or not available

Soil Rating Lines <= 1.7

> 1.7 and <= 6.4

> 6.4 and <= 7.8

> 7.8 and <= 10.7

Not rated or not available

Soil Rating Points <= 1.7

> 1.7 and <= 6.4

> 6.4 and <= 7.8

> 7.8 and <= 10.7

Not rated or not available

Water Features Streams and Canals

Transportation Rails

Interstate Highways

US Routes

Major Roads

Local Roads

Background Aerial Photography

The soil surveys that comprise your AOI were mapped at 1:24,000.

Warning: Soil Map may not be valid at this scale.

Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale.

Please rely on the bar scale on each map sheet for map measurements.

Source of Map: Natural Resources Conservation Service Web Soil Survey URL:

Coordinate System: Web Mercator (EPSG:3857)

Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required.

This product is generated from the USDA-NRCS certified data as of the version date(s) listed below.

Soil Survey Area: Pinellas County, Florida Survey Area Data: Version 16, Sep 17, 2019

Soil map units are labeled (as space allows) for map scales 1:50,000 or larger.

Date(s) aerial images were photographed: Dec 29, 2010—Feb 28, 2014

The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident.

Percent Clay—Pinellas County, Florida

Natural Resources Conservation Service

Web Soil Survey National Cooperative Soil Survey

Percent Clay

15 Manatee loamy fine sand, frequently ponded, 0 to 1 percent slopes

10.7 4.1 3.5%

16 Matlacha and St.

Augustine soils and Urban land

6.4 0.0 0.0%

17 Myakka soils and Urban land

1.7 109.1 92.9%

31 Wabasso soils and Urban land

7.8 4.3 3.7%

Totals for Area of Interest 117.5 100.0%

Description

Clay as a soil separate consists of mineral soil particles that are less than 0.002 millimeter in diameter. The estimated clay content of each soil layer is given as a percentage, by weight, of the soil material that is less than 2 millimeters in diameter. The amount and kind of clay affect the fertility and physical condition of the soil and the ability of the soil to adsorb cations and to retain moisture. They influence shrink-swell potential, saturated hydraulic conductivity (Ksat), plasticity, the ease of soil dispersion, and other soil properties. The amount and kind of clay in a soil also affect tillage and earth-moving operations.

Most of the material is in one of three groups of clay minerals or a mixture of these clay minerals. The groups are kaolinite, smectite, and hydrous mica, the best known member of which is illite.

For each soil layer, this attribute is actually recorded as three separate values in the database. A low value and a high value indicate the range of this attribute for the soil component. A "representative" value indicates the expected value of this attribute for the component. For this soil property, only the representative value is used.

Rating Options

Units of Measure: percent

Aggregation Method: Dominant Component

Component Percent Cutoff: None Specified

Tie-break Rule: Higher

Interpret Nulls as Zero: No

Percent Clay—Pinellas County, Florida

Natural Resources Conservation Service

Web Soil Survey National Cooperative Soil Survey

Layer Options (Horizon Aggregation Method): All Layers (Weighted Average)

Percent Clay—Pinellas County, Florida

Natural Resources Conservation Service

Web Soil Survey National Cooperative Soil Survey

K Factor, Whole Soil—Pinellas County, Florida

Conservation Service

Web Soil Survey National Cooperative Soil Survey

4/3/2020

326200 326300 326400 326500 326600 326700 326800 326900 327000 327100

326200 326300 326400 326500 326600 326700 326800 326900 327000 327100

27° 53' 28'' N

5'

9' ' W

27° 53' 28'' N

5'

0' ' W

27° 53' 5'' N

5'

9' ' W

27° 53' 5'' N

5'

0' ' W

N

Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 17N WGS84 0 200 400 800 1200

Feet 0 50 100 200 300

Meters

Area of Interest (AOI)

Soils Soil Rating Polygons

.02

.05

.10

.15

.17

.20

.24

.28

.32

.37

.43

.49

.55

.64

Not rated or not available

Soil Rating Lines .02

.05

.10

.15

.17

.20

.24

.28

.32

.37

.43

.49

.55

.64

Not rated or not available

Soil Rating Points .02

.05

.10

.15

.17

.20

.24

.28

.32

.37

.43

.49

.55

.64

Not rated or not available

Water Features

Streams and Canals

Transportation Rails

Interstate Highways

US Routes

Major Roads

Local Roads

Background Aerial Photography

The soil surveys that comprise your AOI were mapped at 1:24,000.

Warning: Soil Map may not be valid at this scale.

Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale.

Please rely on the bar scale on each map sheet for map measurements.

Source of Map: Natural Resources Conservation Service Web Soil Survey URL:

Coordinate System: Web Mercator (EPSG:3857)

Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required.

This product is generated from the USDA-NRCS certified data as of the version date(s) listed below.

Soil Survey Area: Pinellas County, Florida Survey Area Data: Version 16, Sep 17, 2019

Soil map units are labeled (as space allows) for map scales 1:50,000 or larger.

Date(s) aerial images were photographed: Dec 29, 2010—Feb 28, 2014

The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident.

K Factor, Whole Soil—Pinellas County, Florida

Natural Resources Conservation Service

Web Soil Survey National Cooperative Soil Survey

K Factor, Whole Soil

15 Manatee loamy fine sand, frequently ponded, 0 to 1 percent slopes

.15 4.1 3.5%

16 Matlacha and St.

Augustine soils and Urban land

.02 0.0 0.0%

17 Myakka soils and Urban land

.02 109.1 92.9%

31 Wabasso soils and Urban land

.02 4.3 3.7%

Totals for Area of Interest 117.5 100.0%

Description

Erosion factor K indicates the susceptibility of a soil to sheet and rill erosion by water. Factor K is one of six factors used in the Universal Soil Loss Equation (USLE) and the Revised Universal Soil Loss Equation (RUSLE) to predict the average annual rate of soil loss by sheet and rill erosion in tons per acre per year. The estimates are based primarily on percentage of silt, sand, and organic matter and on soil structure and saturated hydraulic conductivity (Ksat). Values of K range from 0.02 to 0.69. Other factors being equal, the higher the value, the more susceptible the soil is to sheet and rill erosion by water.

"Erosion factor Kw (whole soil)" indicates the erodibility of the whole soil. The estimates are modified by the presence of rock fragments.

Rating Options

Aggregation Method: Dominant Condition

Component Percent Cutoff: None Specified

Tie-break Rule: Higher

Layer Options (Horizon Aggregation Method): Surface Layer (Not applicable)

K Factor, Whole Soil—Pinellas County, Florida

Natural Resources Conservation Service

Web Soil Survey National Cooperative Soil Survey

Saturated Hydraulic Conductivity (Ksat)—Pinellas County, Florida

Conservation Service

Web Soil Survey National Cooperative Soil Survey

4/3/2020

326200 326300 326400 326500 326600 326700 326800 326900 327000 327100

326200 326300 326400 326500 326600 326700 326800 326900 327000 327100

27° 53' 28'' N

5'

9' ' W

27° 53' 28'' N

5'

0' ' W

27° 53' 5'' N

5'

9' ' W

27° 53' 5'' N

5'

0' ' W

N

Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 17N WGS84 0 200 400 800 1200

Feet 0 50 100 200 300

Meters

Area of Interest (AOI)

Soils Soil Rating Polygons

<= 13.3054

> 13.3054 and <= 66.0588 > 66.0588 and <= 80.1035 > 80.1035 and <= 85.0345 Not rated or not available

Soil Rating Lines <= 13.3054

> 13.3054 and <= 66.0588 > 66.0588 and <= 80.1035 > 80.1035 and <= 85.0345 Not rated or not available

Soil Rating Points <= 13.3054

> 13.3054 and <= 66.0588 > 66.0588 and <= 80.1035 > 80.1035 and <= 85.0345 Not rated or not available

Water Features Streams and Canals

Transportation Rails

Interstate Highways

US Routes

Major Roads

Local Roads

Background Aerial Photography

The soil surveys that comprise your AOI were mapped at 1:24,000.

Warning: Soil Map may not be valid at this scale.

Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale.

Please rely on the bar scale on each map sheet for map measurements.

Source of Map: Natural Resources Conservation Service Web Soil Survey URL:

Coordinate System: Web Mercator (EPSG:3857)

Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required.

This product is generated from the USDA-NRCS certified data as of the version date(s) listed below.

Soil Survey Area: Pinellas County, Florida Survey Area Data: Version 16, Sep 17, 2019

Soil map units are labeled (as space allows) for map scales 1:50,000 or larger.

Date(s) aerial images were photographed: Dec 29, 2010—Feb 28, 2014

The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident.

Saturated Hydraulic Conductivity (Ksat)—Pinellas County, Florida

Natural Resources Conservation Service

Web Soil Survey National Cooperative Soil Survey

Saturated Hydraulic Conductivity (Ksat)

Map unit symbol Map unit name Rating (micrometers per second)

Acres in AOI Percent of AOI

15 Manatee loamy fine sand, frequently ponded, 0 to 1 percent slopes

13.3054 4.1 3.5%

16 Matlacha and St.

Augustine soils and Urban land

85.0345 0.0 0.0%

17 Myakka soils and Urban land

80.1035 109.1 92.9%

31 Wabasso soils and Urban land

66.0588 4.3 3.7%

Totals for Area of Interest 117.5 100.0%

Description

Saturated hydraulic conductivity (Ksat) refers to the ease with which pores in a saturated soil transmit water. The estimates are expressed in terms of micrometers per second. They are based on soil characteristics observed in the field, particularly structure, porosity, and texture. Saturated hydraulic conductivity is considered in the design of soil drainage systems and septic tank absorption fields.

For each soil layer, this attribute is actually recorded as three separate values in the database. A low value and a high value indicate the range of this attribute for the soil component. A "representative" value indicates the expected value of this attribute for the component. For this soil property, only the representative value is used.

The numeric Ksat values have been grouped according to standard Ksat class limits.

Rating Options

Units of Measure: micrometers per second

Aggregation Method: Dominant Component

Component Percent Cutoff: None Specified

Tie-break Rule: Fastest

Interpret Nulls as Zero: No

Layer Options (Horizon Aggregation Method): All Layers (Weighted Average)

Saturated Hydraulic Conductivity (Ksat)—Pinellas County, Florida

Natural Resources Conservation Service

Web Soil Survey National Cooperative Soil Survey

Surface Water Management, System—Pinellas County, Florida

Conservation Service

Web Soil Survey National Cooperative Soil Survey

4/3/2020

326200 326300 326400 326500 326600 326700 326800 326900 327000 327100

326200 326300 326400 326500 326600 326700 326800 326900 327000 327100

27° 53' 28'' N

5'

9' ' W

27° 53' 28'' N

5'

0' ' W

27° 53' 5'' N

5'

9' ' W

27° 53' 5'' N

5'

0' ' W

N

Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 17N WGS84 0 200 400 800 1200

Feet 0 50 100 200 300

Meters

Area of Interest (AOI)

Soils Soil Rating Polygons

Very limited

Somewhat limited

Not limited

Not rated or not available

Soil Rating Lines Very limited

Somewhat limited

Not limited

Not rated or not available

Soil Rating Points Very limited

Somewhat limited

Not limited

Not rated or not available

Water Features Streams and Canals

Transportation Rails

Interstate Highways

US Routes

Major Roads

Local Roads

Background Aerial Photography

The soil surveys that comprise your AOI were mapped at 1:24,000.

Warning: Soil Map may not be valid at this scale.

Enlargement of maps beyond the scale of mapping can cause…