F - Geotechnical Report.pdf

PDF 4 MB Posted Oct 16, 2026

Attached to: 26-13 Wor982210D (Worth)
Solicitation number: 26-13 Wor982210D (Worth)
Issued by: Winnebago County, Iowa

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Written by GovTribe AI · Oct 20, 2026

Geotechnical Report Summary

This is a Factual Geotechnical Report prepared by Chosen Valley Testing, Inc. for Worth County, Iowa, under the supervision of Matthew J. Reisdorfer, PE (License #22234). The report documents subsurface conditions for a proposed wetland system located in Fertile Township, SE Section 10, T98N-R22W, Iowa. The geotechnical investigation included ten penetration test borings drilled to approximately 15 feet below the surface, supplemented by four hand auger borings and slope stability analysis at four designated stations. The work was authorized by Mr. Brandon Short, Design Engineer for Bolton & Menk, Inc., and completed in November 2024, with hand auger work conducted in March 2025.

Subsurface stratification consists of topsoil (organic lean clay, 1-2 feet deep), B-Horizon soils in select borings (lean clay and sandy clay, 4-6 feet deep), alluvial clay (3-9 feet deep), and alluvial sand and gravel terminating the borings at approximately 16 feet depth. Standard Penetration Test (SPT) results yielded N-Values ranging from 2-13 blows per foot (BPF) in alluvial clays and 3-34 BPF in alluvial sands. Pocket penetrometer tests on cohesive soils returned values of 1-4 tons per square foot. Groundwater was encountered at depths of 7-14 feet during drilling, corresponding to elevations of approximately 1180-1188 feet. Slope stability analyses performed at four stations using Slide software and Janbu's and Bishop's Methods produced short-term and long-term safety factors ranging from 1.227 to 3.089, all exceeding the minimum desired safety factor of 1.2 for slopes not near structures or human life. The report recommends protecting exposed slopes with vegetation or erosion control measures to prevent surface erosion and shallow failures.

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IOWA MINNESOTA WISCONSIN

Updated Factual Geotechnical Report:

Proposed Wetland SE ¼ Sec. 10 – T98N – R22W Fertile Township, Worth County, Iowa

CVT# 24387.24.IAM

Prepared for:

Mr. Brandon Short Bolton & Menk, Inc.

Certification:

I hereby certify that this engineering document was prepared by me or under my direct personal supervision and that I am a duly licensed Professional Engineer under the laws of the State of Iowa.

April 21, 2025

(signature) (date)

Printed or typed name: Matthew J. Reisdorfer, PE.

License number: 22234 .

My license renewal date is December 31, 2025 .

Pages or sheets covered by this seal:

M i n n e s o t a I o w a W i s c o n s i n

TABLE OF CONTENTS

A. Introduction

A.1. Purpose

A.2. Scope

A.3. Boring Locations and Elevation

A.4. Geologic Background

B. Subsurface Data

B.1. Stratification

B.2. Penetration Test Results

B.3. Groundwater Data

F. Slope Stability Analysis

C. Level of Care

Appendix

Soil Boring Location Sketch

Log of Boring # B1-B10 and HA1-HA4

Slope Stability Cross Sections

Legend to Soil Description

Worth County Wetland November 25, 2024

Project: 24387.24.IAM Page - 2

Chosen Valley Testing, Inc.

Geotechnical Engineering and Testing • 421 N Georgia Avenue • Mason City, IA 50401 • Telephone (641) 201-1050 • masoncity@cvtesting.com

Mr. Brandon Short April 21, 2025

Design Engineer

Bolton & Menk, Inc.

1519 Baltimore Drive

Ames, Iowa 50010

Brandon.short@bolton-menk.com

Re: Factual Geotechnical Evaluation

SE ¼ Sec. 10 – T98N – R22W

Fertile Township, Worth County, Iowa

CVT Proposal Number: 24387.24.IAM

Dear Mr. Short:

This factual report was prepared for the proposed wetland located in Fertile Township, Worth County, Iowa.

Our services were authorized by Mr. Brandon Short, Design Engineer for Bolton & Menk, Inc.

A. Introduction

The intent of this report is to present our results to the client in the same logical sequence that led us to arrive at the opinions and recommendations expressed. Since our services must often be completed before the design, assumptions are sometimes needed to prepare a proper evaluation and to analyze the data. A complete and thorough review of this entire document, including the assumptions and the appendices, should be undertaken immediately upon receipt.

A.1. Purpose

This factual report was prepared for the proposed wetland located in Fertile Township, Worth County, Iowa.

Our services were authorized by Mr. Brandon Short, Design Engineer for Bolton & Menk, Inc.

A.2. Scope

To obtain data for analysis, our services included ten penetration test borings. The borings were drilled to depths of about 15 feet below the surface. Additional services consisting of hand auger drilling and slope stability analysis were also authorized. Our engineering scope consisted of providing a factual discussion of the soils and materials encountered during our exploration.

mailto:masoncity@cvtesting.com mailto:Brandon.short@bolton-menk.com

Project: 24387.24.IAM Page - 3

A.3. Boring Locations and Elevation

The desired boring locations were indicated to Chosen Valley Testing based on on-site staking provided by the client. The Boring Location Sketch in the Appendix shows the approximate location drilled. Elevations at the borings were provided by the client.

A.4. Geologic Background

A geotechnical report is based on subsurface data collected for the specific structure or problem. Available geologic data from the region can help interpretation of the data and is briefly summarized in this section.

Area geologic maps indicate that the natural upper soils are primarily alluvium (water deposited) consisting of clay, silt, sand and gravel mixtures. Bedrock was expected to be within 50 to 100 feet below the surface and consists of limestone, dolomite, and shale of the Shell Rock Formation.

B. Subsurface Data

B.1. Stratification

At the surface, the borings met topsoil consisting mostly of slightly organic-to-organic lean clay to depths of about 1 to 2 feet below the surface. Below the topsoil, Borings B-4, B-8, B-9 and B-10 met B-Horizon consisting of mostly lean clay and sandy clay to depths of about 4 to 6 ½ feet below the surface. B-Horizon soils are similar in color and characteristics to that of topsoil but are less organic.

Alluvial clay was met below the B-Horizon and below the topsoil in Borings B-1, B-2, B-3, B-5, B-6 and B-7 to depths of about 3 to 9 feet below the surface.

Alluvial sand and gravel followed the alluvial clay in all borings. The borings terminated in alluvial sand and gravel at depths of about 16 feet below the surface.

The following simplified cross-section summarizes the boring data. For more detailed information, please refer to the Log of Boring sheets in the Appendix.

Project: 24387.24.IAM Page - 4

B-1 B-2 B-3 B-4 B-5 B-6 B-7 B-8 B-9 B-10

A p p ro x im a te

E le v a ti o n o n t h e D a tu m U s e d F e e t)

Boring Number

Topsoil

B-Horizon

Alluvial Clay

Alluvial Sand and Gravel

Below Boring

North to South

B.2. Penetration Test Results

The number of blows needed for the hammer to advance the penetration test sampler is an indicator of soil characteristics. The results tend to be more meaningful for natural mineral soils, than for fill soils. In fill soils, compaction tests are more meaningful.

Penetration resistance values ("N" Values) of 2 to 13 Blows per Foot (BPF) were recorded in the alluvial clays, indicating they were soft to stiff. The alluvial sands returned N-Values of 3 to 34 BPF, indicating they were very loose to dense. The B-Horizon clays returned N-Values of 2 to 7 BPF, indicating they were soft to medium.

A pocket penetrometer was used to provide additional data on the compressive strength of cohesive soils. The alluvial clays returned values of 1 ¼ to 3 ¾ tons per square foot (tsf). The B-Horizon clays returned values of

1 ¼ to 4 ¼ tsf.

A key to descriptors used to qualify the relative density of soil (such as soft, stiff, loose, and dense) can be found on the Legend to Soil Description in the Appendix.

Project: 24387.24.IAM Page - 5

B.3. Groundwater Data

During the drilling operation, the drillers may note the presence of moisture on the sampling instrument, in the cuttings, or within the borehole. These observations are recorded on the boring logs. The water level may vary with weather; time of year and other factors and the presence or absence of water during the drilling is subject to interpretation and is not always conclusive.

Water was encountered in most of the borings at depths of about 7 to 14 feet below the surface during drilling.

The observed water levels correspond to an elevation of about 1180 ½ to 1188 feet on the datum used to locate the borings. Elevated moisture contents were recorded in the near surface clay samples as well. Groundwater levels at the site are expected to fluctuate seasonally with nearby creeks and rivers, as well as with local weather patterns.

F. Slope Stability Analysis

Slope stability analyses were performed along the drainage ditch embankment near STA 2+40, STA 9+10, STA 13+25 and STA 14+00 using the elevation data provided by Bolton & Menk, Inc. and the computer software Slide that employs both Janbu’s and Bishops’ Methods of Analysis. Data from our boring logs and hand auger exploration were used in our analysis. Design slopes ranging from 1.6:1 to 1.9:1 were provided by Bolton & Menk, Inc.

The following table provides further detail on the short term and long term stability safety factors at each of the four stations that were analyzed:

Station Short Term Stability Safety Factor

(West Bank/East Bank)

Long Term Stability Safety Factor

(West Bank/East Bank)

STA 2+40 1.973 / 1.556 1.568 / 1.227

STA 9+10 2.393 / 1.925 1.793 / 1.496

STA 13+25 3.089 / 2.157 2.982 / 1.994

STA 14+00 1.850 / 1.419 1.496 / 1.244

A minimum safety factor of 1.2 is normally desired for slopes not near structures or not where they may pose a threat to human life. All safety factors from our analysis exceeded the minimum safety factor.

It should be noted that exposed slopes will be prone to surface erosion and shallow failures. Therefore, we recommend protecting surfaces with vegetation or other erosion control methods.

C. Level of Care

The services provided for this project have been conducted in a manner consistent with that level of care and skill ordinarily exercised by members of the profession currently practicing in this area, under similar budget and time constraints. This is our professional responsibility. No other warranty, expressed or implied, is made.

Project: 24387.24.IAM Page - 6

Appendix

Soil Boring Location Sketch

Log of Boring: B1-B10 and HA1-HA4

Slope Stability Cross Sections

Legend to Soil Description

ORGANIC CLAY trace of roots, black, wet.

(Topsoil)

LEAN CLAY with SAND trace of gravel, trace of iron staining, light grey, wet, rather stiff.

(Alluvium)

POORLY-GRADED SAND to CLAYEY SAND mostly medium grained, trace of gravel, trace of iron staining, brown, moist, medium dense.

(Alluvium)

POORLY-GRADED SAND mostly medium grained, trace of gravel, brown, moist, medium dense.

(Alluvium)

POORLY-GRADED GRAVEL with SAND mostly coarse grained, brown, moist, loose.

(Alluvium)

POORLY-GRADED SAND mostly medium grained, trace of gravel, grey, moist to waterbearing, loose.

(Alluvium)

End of boring.

Boring sealed upon completion.

Elevations provided by Bolton & Menk, Inc.

MC = 38.1%

PP = 2.75 tsf

Water encountered at about 12 feet during drilling.

1.5

4.0

6.5

9.0

11.5

16.0

1195.1

1192.6

1190.1

1187.6

1185.1

1180.6

B-01 page 1 of 1

0.0

BORING: B-01

24387.24.IAM

Description of Materials

(ASTM D 2487/2488)

PROJECT:

1196.6

L O G O F B O R I N G

CHOSEN VALLEY TESTING

SCALE: 1" = 2'

BPF

24387.24.IAM

Factual Geotechnical Evaluation Proposed Wetland SE 1/4 Sec. 10 - T98N - R22W Fertile Township, Worth County, Iowa

See attached sketch

LOCATION:

WLUSCS

Symbol Tests and NotesDepthElev.

DATE: 11/6/2024

C V

T S

T A

N D

A R

.2 4.

O R

T H

C O

U N

T Y

W E

N D

P J

L O

G A

G N

N N

D T

Slightly Organic LEAN CLAY trace of roots, black, wet.

(Topsoil) SANDY LEAN CLAY trace of gravel, trace of iron staining, light grey, wet, rather stiff.

(Alluvium)

CLAYEY SAND to SILTY SAND mostly fine grained, trace of gravel, light brown, moist, loose to medium dense.

(Alluvium)

POORLY-GRADED SAND mostly medium grained, trace of gravel, light brown to grey, moist to waterbearing, loose to medium dense.

(Alluvium)

Trace of clay below about 9 feet to about 11.5 feet.

End of boring.

Boring sealed upon completion.

Elevations provided by Bolton & Menk, Inc.

Water encountered at about 12 feet during drilling.

1.0

3.0

6.5

16.0

1198.4

1196.4

1192.9

1183.4

B-02 page 1 of 1

0.0

BORING: B-02

24387.24.IAM

Description of Materials

(ASTM D 2487/2488)

PROJECT:

1199.4

L O G O F B O R I N G

CHOSEN VALLEY TESTING

SCALE: 1" = 2'

BPF

24387.24.IAM

Factual Geotechnical Evaluation Proposed Wetland SE 1/4 Sec. 10 - T98N - R22W Fertile Township, Worth County, Iowa

See attached sketch

LOCATION:

WLUSCS

Symbol Tests and NotesDepthElev.

DATE: 11/6/2024

C V

T S

T A

N D

A R

.2 4.

O R

T H

C O

U N

T Y

W E

N D

P J

L O

G A

G N

N N

D T

(Topsoil)

SANDY LEAN CLAY trace of gravel, trace of iron staining, dark grey, wet, soft to rather soft.

(Alluvium)

POORLY-GRADED SAND mostly medium grained, trace of gravel, grey, waterbearing, very loose to loose.

(Alluvium)

POORLY-GRADED SAND to CLAYEY SAND mostly medium grained, trace of gravel, grey, waterbearing, loose.

(Alluvium)

POORLY-GRADED SAND with GRAVEL mostly coarse grained, brown, moist, loose.

(Alluvium)

End of boring.

Boring sealed upon completion.

Elevations provided by Bolton & Menk, Inc.

PP = 1.75 tsf, MC = 29.9%

Water encountered at about 7 feet during drilling.

2.0

7.5

9.0

11.5

16.0

1193.0

1187.5

1186.0

1183.5

1179.0

B-03 page 1 of 1

0.0

BORING: B-03

24387.24.IAM

Description of Materials

(ASTM D 2487/2488)

PROJECT:

1195.0

L O G O F B O R I N G

CHOSEN VALLEY TESTING

SCALE: 1" = 2'

BPF

24387.24.IAM

Factual Geotechnical Evaluation Proposed Wetland SE 1/4 Sec. 10 - T98N - R22W Fertile Township, Worth County, Iowa

See attached sketch

LOCATION:

WLUSCS

Symbol Tests and NotesDepthElev.

DATE: 11/6/2024

C V

T S

T A

N D

A R

.2 4.

O R

T H

C O

U N

T Y

W E

N D

P J

L O

G A

G N

N N

D T

(Topsoil)

SANDY LEAN CLAY trace of gravel, black, wet, soft to medium.

(B-Horizon)

LEAN CLAY with SAND trace of iron staining, dark brown, wet, rather soft.

(Alluvium)

POORLY-GRADED SAND to CLAYEY SAND with GRAVEL mostly medium grained, grey, moist, loose.

(Alluvium)

POORLY-GRADED SAND mostly medium grained, trace of gravel, grey, moist, loose.

(Alluvium)

End of boring.

Boring sealed upon completion.

Elevations provided by Bolton & Menk, Inc.

PP = 4.25 tsf, MC = 19.8%

PP = 3.0 tsf, MC = 25.4%

PP = 1.25 tsf

2.0

6.5

9.0

11.5

16.0

1195.7

1191.2

1188.7

1186.2

1181.7

B-04 page 1 of 1

0.0

BORING: B-04

24387.24.IAM

Description of Materials

(ASTM D 2487/2488)

PROJECT:

1197.7

L O G O F B O R I N G

CHOSEN VALLEY TESTING

SCALE: 1" = 2'

BPF

24387.24.IAM

Factual Geotechnical Evaluation Proposed Wetland SE 1/4 Sec. 10 - T98N - R22W Fertile Township, Worth County, Iowa

See attached sketch

LOCATION:

WLUSCS

Symbol Tests and NotesDepthElev.

DATE: 11/6/2024

C V

T S

T A

N D

A R

.2 4.

O R

T H

C O

U N

T Y

W E

N D

P J

L O

G A

G N

N N

D T

(Topsoil)

LEAN CLAY with SAND trace of gravel, trace of iron staining, dark brown to grey, wet, rather soft to medium.

(Alluvium)

POORLY-GRADED SAND mostly medium grained, trace of gravel, grey to brown, moist to waterbearing, loose to medium dense.

(Alluvium)

Trace of clay below about 11.5 feet to about 14 feet.

End of boring.

Boring sealed upon completion.

Elevations provided by Bolton & Menk, Inc.

MC = 44.2%

PP = 1.25 tsf, MC = 30.3%

Water encountered at about 10 feet during drilling.

2.0

6.5

16.0

1195.5

1191.0

1181.5

B-05 page 1 of 1

0.0

BORING: B-05

24387.24.IAM

Description of Materials

(ASTM D 2487/2488)

PROJECT:

1197.5

L O G O F B O R I N G

CHOSEN VALLEY TESTING

SCALE: 1" = 2'

BPF

24387.24.IAM

Factual Geotechnical Evaluation Proposed Wetland SE 1/4 Sec. 10 - T98N - R22W Fertile Township, Worth County, Iowa

See attached sketch

LOCATION:

WLUSCS

Symbol Tests and NotesDepthElev.

DATE: 11/6/2024

C V

T S

T A

N D

A R

.2 4.

O R

T H

C O

U N

T Y

W E

N D

P J

L O

G A

G N

N N

D T

(Topsoil)

SANDY LEAN CLAY trace of gravel, trace of iron staining, light grey, wet, rather stiff to stiff.

(Alluvium)

POORLY-GRADED SAND mostly medium to coarse grained, trace of gravel, light brown to grey, moist to waterbearing, loose to medium dense.

(Alluvium)

Trace of silt below about 14 feet.

End of boring.

Boring sealed upon completion.

Elevations provided by Bolton & Menk, Inc.

MC = 14.5%

Water encountered at about 10 feet during drilling.

2.0

5.5

16.0

1193.6

1190.1

1179.6

B-06 page 1 of 1

0.0

BORING: B-06

24387.24.IAM

Description of Materials

(ASTM D 2487/2488)

PROJECT:

1195.6

L O G O F B O R I N G

CHOSEN VALLEY TESTING

SCALE: 1" = 2'

BPF

24387.24.IAM

Factual Geotechnical Evaluation Proposed Wetland SE 1/4 Sec. 10 - T98N - R22W Fertile Township, Worth County, Iowa

See attached sketch

LOCATION:

WLUSCS

Symbol Tests and NotesDepthElev.

DATE: 11/4/2024

C V

T S

T A

N D

A R

.2 4.

O R

T H

C O

U N

T Y

W E

N D

P J

L O

G A

G N

N N

D T

(Topsoil)

SANDY LEAN CLAY trace of gravel, grey, wet, rather stiff.

(Alluvium)

LEAN CLAY with SAND trace of iron staining, light grey, wet, rather stiff.

(Alluvium)

POORLY-GRADED SAND mostly medium grained, trace of gravel, grey, moist to waterbearing, loose to medium dense.

(Alluvium)

Trace of clay below about 14 feet.

End of boring.

Boring sealed upon completion.

Elevations provided by Bolton & Menk, Inc.

MC = 16.3%

PP = 3.75 tsf

Water encountered at about 10 feet during drilling.

2.0

4.0

6.0

16.0

1192.3

1190.3

1188.3

1178.3

B-07 page 1 of 1

0.0

BORING: B-07

24387.24.IAM

Description of Materials

(ASTM D 2487/2488)

PROJECT:

1194.3

L O G O F B O R I N G

CHOSEN VALLEY TESTING

SCALE: 1" = 2'

BPF

24387.24.IAM

Factual Geotechnical Evaluation Proposed Wetland SE 1/4 Sec. 10 - T98N - R22W Fertile Township, Worth County, Iowa

See attached sketch

LOCATION:

WLUSCS

Symbol Tests and NotesDepthElev.

DATE: 11/4/2024

C V

T S

T A

N D

A R

.2 4.

O R

T H

C O

U N

T Y

W E

N D

P J

L O

G A

G N

N N

D T

(Topsoil)

SANDY LEAN CLAY trace of gravel, black, wet, soft to medium.

(B-Horizon)

LEAN CLAY trace of iron staining, brown, wet, soft.

(Alluvium) CLAYEY SAND to SANDY LEAN CLAY mostly medium grained, trace of gravel, trace of roots, trace of wood, grey, moist, loose.

(Alluvium)

POORLY-GRADED SAND mostly medium grained, trace of gravel, trace of clay, grey, moist, dense.

(Alluvium)

POORLY-GRADED SAND to CLAYEY SAND mostly medium grained, trace of gravel, brown, moist, medium dense.

(Alluvium)

POORLY-GRADED SAND mostly medium grained, trace of gravel, trace of clay, grey, moist, medium dense.

(Alluvium)

End of boring.

Boring sealed upon completion.

Elevations provided by Bolton & Menk, Inc.

PP = 2.5 tsf, MC = 25.7%

PP = 1.5 tsf

PP = 1.25 tsf

2.0

6.0

6.5

9.0

11.5

14.0

16.0

1196.1

1192.1

1191.6

1189.1

1186.6

1184.1

1182.1

B-08 page 1 of 1

0.0

BORING: B-08

24387.24.IAM

Description of Materials

(ASTM D 2487/2488)

PROJECT:

1198.1

L O G O F B O R I N G

CHOSEN VALLEY TESTING

SCALE: 1" = 2'

BPF

24387.24.IAM

Factual Geotechnical Evaluation Proposed Wetland SE 1/4 Sec. 10 - T98N - R22W Fertile Township, Worth County, Iowa

See attached sketch

LOCATION:

WLUSCS

Symbol Tests and NotesDepthElev.

DATE: 11/4/2024

C V

T S

T A

N D

A R

.2 4.

O R

T H

C O

U N

T Y

W E

N D

P J

L O

G A

G N

N N

D T

(Topsoil)

LEAN CLAY trace of sand, black, wet, meidum.

(B-Horizon)

SANDY LEAN CLAY trace of gravel, black, wet, soft.

(B-Horizon) LEAN CLAY trace of iron staining, grey to brown, wet, soft.

(Alluvium)

POORLY-GRADED SAND to CLAYEY SAND mostly medium grained, trace of gravel, brown, moist, loose.

(Alluvium)

POORLY-GRADED SAND with GRAVEL mostly medium grained, brown, moist, medium dense.

(Alluvium)

POORLY-GRADED SAND with LEAN CLAY mostly medium grained, trace of gravel, grey, moist, medium dense.

(Alluvium)

POORLY-GRADED SAND with GRAVEL and LEAN CLAY mostly medium grained, grey, moist to waterbearing, medium dense.

(Alluvium)

End of boring.

Boring sealed upon completion.

Elevations provided by Bolton & Menk, Inc.

MC = 35.1%

PP = 2.0 tsf

Water encountered at about 14 feet during drilling.

1.5

4.0

5.0

6.5

9.0

11.5

14.0

16.0

1193.3

1190.8

1189.8

1188.3

1185.8

1183.3

1180.8

1178.8

B-09 page 1 of 1

0.0

BORING: B-09

24387.24.IAM

Description of Materials

(ASTM D 2487/2488)

PROJECT:

1194.8

L O G O F B O R I N G

CHOSEN VALLEY TESTING

SCALE: 1" = 2'

BPF

24387.24.IAM

Factual Geotechnical Evaluation Proposed Wetland SE 1/4 Sec. 10 - T98N - R22W Fertile Township, Worth County, Iowa

See attached sketch

LOCATION:

WLUSCS

Symbol Tests and NotesDepthElev.

DATE: 11/4/2024

C V

T S

T A

N D

A R

.2 4.

O R

T H

C O

U N

T Y

W E

N D

P J

L O

G A

G N

N N

D T

(Topsoil)

SANDY LEAN CLAY trace of gravel, black, wet, medium.

(B-Horizon)

LEAN CLAY trace of gravel, trace of iron staining, trace of sand, grey to dark grey, wet, rather soft.

(Alluvium)

CLAYEY SAND mostly medium grained, trace of gravel, brown, moist, loose.

(Alluvium)

POORLY-GRADED SAND to CLAYEY SAND mostly medium grained, trace of gravel, brown to grey, moist, medium dense to dense.

(Alluvium)

With GRAVEL below about 11.5 feet.

POORLY-GRADED SAND with GRAVEL mostly medium graiend, grey, moist to waterbearing, medium dense.

(Alluvium)

End of boring.

Boring sealed upon completion.

Elevations provided by Bolton & Menk, Inc.

PP = 2.25 tsf, MC = 26.6%

PP = 1.25 tsf, MC = 29.8%

Water encountered at about 14 feet during drilling.

1.5

4.0

6.5

9.0

14.0

16.0

1196.2

1193.7

1191.2

1188.7

1183.7

1181.7

B-10 page 1 of 1

0.0

BORING: B-10

24387.24.IAM

Description of Materials

(ASTM D 2487/2488)

PROJECT:

1197.7

L O G O F B O R I N G

CHOSEN VALLEY TESTING

SCALE: 1" = 2'

BPF

24387.24.IAM

Factual Geotechnical Evaluation Proposed Wetland SE 1/4 Sec. 10 - T98N - R22W Fertile Township, Worth County, Iowa

See attached sketch

LOCATION:

WLUSCS

Symbol Tests and NotesDepthElev.

DATE: 11/4/2024

C V

T S

T A

N D

A R

.2 4.

O R

T H

C O

U N

T Y

W E

N D

P J

L O

G A

G N

N N

D T

Slightly Organic SANDY LEAN CLAY trace of gravel, black, wet.

SANDY LEAN CLAY trace of gravel, black, wet.

(B-Horizon)

Trace of roots below about 2 feet.

SANDY LEAN CLAY trace of gravel, dark brown, wet.

(Alluvium) Trace of iron staining below about 4 feet.

CLAYEY SAND to SILTY SAND mostly fine grained, trace of gravel, light brown to light grey, moist.

(Alluvium) End of boring.

Boring sealed upon completion.

Elevations estimated from Iowa DNR LiDAR.

1.0

3.0

5.0

6.0

HA-1 page 1 of 1

0.0

BORING: HA-1

24387.24.IAM

Description of Materials

(ASTM D 2487/2488)

PROJECT:

L O G O F B O R I N G

CHOSEN VALLEY TESTING

SCALE: 1" = 2'

BPF

24387.24.IAM

Factual Geotechnical Evaluation Proposed Wetland SE 1/4 Sec. 10 - T98N - R22W Fertile Township, Worth County, Iowa

See attached sketch

LOCATION:

WLUSCS

Symbol Tests and NotesDepthElev.

DATE: 3/21/2025

C V

T S

T A

N D

A R

.2 4.

O R

T H

C O

U N

T Y

W E

N D

P J

L O

G A

G N

N N

D T

Slightly Organic SANDY LEAN CLAY trace of gravel, black, wet.

(Topsoil) CLAYEY SAND mostly medium grained, trace of gravel, brown to dark brown, moist.

(Alluvium) POORLY-GRADED SAND to CLAYEY SAND mostly medium grained, trace of gravel, brown, moist.

(Alluvium) POORLY-GRADED SAND mostly medium grained, trace of gravel, trace of clay, brown, moist.

(Alluvium) End of boring.

Boring sealed upon completion.

Elevations estimated from Iowa DNR LiDAR.

1.0

2.0

3.0

4.0

HA-2 page 1 of 1

0.0

BORING: HA-2

24387.24.IAM

Description of Materials

(ASTM D 2487/2488)

PROJECT:

L O G O F B O R I N G

CHOSEN VALLEY TESTING

SCALE: 1" = 2'

BPF

24387.24.IAM

Factual Geotechnical Evaluation Proposed Wetland SE 1/4 Sec. 10 - T98N - R22W Fertile Township, Worth County, Iowa

See attached sketch

LOCATION:

WLUSCS

Symbol Tests and NotesDepthElev.

DATE: 3/21/2025

C V

T S

T A

N D

A R

.2 4.

O R

T H

C O

U N

T Y

W E

N D

P J

L O

G A

G N

N N

D T

Slightly Organic LEAN CLAY black, wet.

(Topsoil)

CLAYEY SAND mostly medium grained, dark brown, moist.

(Alluvium)

POORLY-GRADED SAND to CLAYEY SAND mostly medium grained, dark brown, moist.

(Alluvium)

End of boring.

Boring sealed upon completion.

Elevations estimated from Iowa DNR LiDAR.

1.0

2.5

5.0

HA-3 page 1 of 1

0.0

BORING: HA-3

24387.24.IAM

Description of Materials

(ASTM D 2487/2488)

PROJECT:

L O G O F B O R I N G

CHOSEN VALLEY TESTING

SCALE: 1" = 2'

BPF

24387.24.IAM

Factual Geotechnical Evaluation Proposed Wetland SE 1/4 Sec. 10 - T98N - R22W Fertile Township, Worth County, Iowa

See attached sketch

LOCATION:

WLUSCS

Symbol Tests and NotesDepthElev.

DATE: 3/21/2025

C V

T S

T A

N D

A R

.2 4.

O R

T H

C O

U N

T Y

W E

N D

P J

L O

G A

G N

N N

D T

Slightly Organic LEAN CLAY black, wet to very wet.

(Topsoil) SANDY LEAN CLAY trace of roots, black, wet.

(B-Horizon)

CLAYEY SAND to SILTY SAND mostly fine grained, trace of gravel, brown to dark brown, moist.

(Alluvium)

CLAYEY SAND mostly fine grained, trace of gravel, brown, moist.

(Alluvium) End of boring.

Boring sealed upon completion.

Elevations estimated from Iowa DNR LiDAR.

1.0

2.0

4.0

5.0

HA-4 page 1 of 1

0.0

BORING: HA-4

24387.24.IAM

Description of Materials

(ASTM D 2487/2488)

PROJECT:

L O G O F B O R I N G

CHOSEN VALLEY TESTING

SCALE: 1" = 2'

BPF

24387.24.IAM

Factual Geotechnical Evaluation Proposed Wetland SE 1/4 Sec. 10 - T98N - R22W Fertile Township, Worth County, Iowa

See attached sketch

LOCATION:

WLUSCS

Symbol Tests and NotesDepthElev.

DATE: 3/21/2025

C V

T S

T A

N D

A R

.2 4.

O R

T H

C O

U N

T Y

W E

N D

P J

L O

G A

G N

N N

D T

Boring Location Sketch

SE ¼ Sec. 10 – T98N – R22W

Fertile Township, Worth County, Iowa

24387.24.IAM

Legend

Boring Location

B-01

B-05

B-02

B-03 B-04

B-06

B-07

B-08

B-10

B-09

HA-3

HA-4

HA-2

HA-1

1.9731.973

W1.9731.973