Geotechnical Report

Consulting Geotechnical Engineers

Environmental Science

Construction Management & Inspection

Construction Materials Testing

Hydrogeology/Groundwater Monitoring

Earth Instrumentation Services

CCG

5871 New Peachtree Road

Doraville, GA 30340-1084

Phone: 770/457-9776

Fax: 770/457-9964

April 20, 2021

Project Number: 4976.001.21

Kaizen Collaborative Design, Inc.

2390 Main Street

Tucker, Georgia 30084

Attention: Ms. Allison Clarke

RE: Subsurface Exploration

Morgan Falls Connector Phase 2A

Edgewater Apartments

Sandy Springs, Georgia

Ladies & Gentlemen:

We have completed our subsurface exploration and are providing our recommendations, together with the results of our field testing and our conclusions based on them. This work was authorized by Ms. Allison Clarke.

If you should have any questions concerning this information, please feel free to call. It has been a pleasure working with you and we look forward to being of continued service to

Kaizen Collaborative.

Sincerely, CHATTAHOOCHEE CONSULTING GROUP, INC.

William T. Sheppard

Project Engineer

Consulting Geotechnical Engineers

Environmental Science

Construction Management & Inspection

Construction Materials Testing

Hydrogeology/Groundwater Monitoring

Earth Instrumentation Services

CCG

5871 New Peachtree Road

Doraville, GA 30340-1084

Phone: 770/457-9776

Fax: 770/457-9964

REPORT OF

SUBSURFACE EXPLORATION

Edgewater Apartments

Prepared for:

KAIZEN COLLABORATIVE DESIGN, INC.

2390 Main Street

Tucker, Georgia 30084

April 20, 2021

Prepared by:

Chattahoochee Consulting Group, Inc.

Project No. 4976.001.21

CONTENTS

PROJECT CONSIDERATIONS

1. Scope of Work 2

2. Description of Project 2

3. Limitations 2

SITE CONDITIONS

4. Site Description 2

5. Soil Conditions 3

6. Groundwater 6

SEISMIC DESIGN PARAMETERS

7. Site Class 6

FOUNDATION RECOMMENDATIONS

8. Retaining Wall near Spillway (Station 7) 7

9. Proposed Bridge Crossing at Spillway 7

10. Proposed Boardwalk Station Stations 9 to 40 8

11. Retaining Wall near Clubhouse 9

12. Proposed Bridge Crossing at Clubhouse 9

13. Retaining Walls along Cimarron Parkway 9

MISCELLANEOUS

14. Settlement 10

15. Wall Deign Parameters 10

16. Geotechnical Quality Control 11

17. Consultation 11

FIGURE 1- Boring Location Plan – Borings B-1 to B-5 FIGURE 2- Boring Location Plan – Borings B-6, B-7 & B-16 to B-18 FIGURE 3- Boring Location Plan – Borings B-8 & B-9 FIGURE 4- Boring Location Plan – Borings B-10 to B-14 FIGURE 5- Boring Location Plan – Boring B-15

APPENDIX A - Field Procedures APPENDIX B - Boring Logs

Z:\4976.001.21 Morgan Falls Geo Rpt

REPORT OF

SUBSURFACE EXPLORATION

The findings of this exploration are presented below, together with the analyses and conclusions based on them. The field and exploratory procedures are discussed in the

Appendix.

PROJECT CONSIDERATIONS

1. Scope of Work - The purpose of this exploration was to determine the subsurface conditions for the structures for the Morgan Falls Connector Phase 2A project. The composition and consistencies of the existing overburden soils were evaluated, as well as the depth to rock and groundwater at each of these areas. Appropriate recommendations are made in this report for the foundation designs.

2. Description of Project - Information for this project was provided by Ms. Allison

Clarke of Kaizen Collaborative. We understand that in conjunction with the proposed new

Morgan Falls Connector Phase 2A Trail at the Edgewater Apartments, it is proposed to construct a trail with two bridge crossings, a top down boardwalk section and new retaining wall structures at multiple locations.

3. Limitations - The analyses and recommendations presented in this report are based on the preceding project information, as well as on the result of the exploration. While it is not likely that conditions will differ greatly from those observed in the borings, it is always possible that variations can occur between or away from the borehole locations. If it becomes apparent during construction that soils conditions differing significantly from those discussed in Paragraph (5) are being encountered, this office should be notified at once so that their effects can be determined and any remedial measures necessary be prescribed. Also, should the nature of the project change to a major degree, these recommendations may have to be re-evaluated. All testing was performed in general compliance with ASTM guidelines. This report has been prepared for the exclusive use of

Kaizen Collaborative and their consultants. No other third party beneficiaries may rely on this report without express written approval by CCG, Inc.

SITE CONDITIONS

4. Site Description - The project site is the Morgan Falls Connector Phase 2A Trail at the Edgewater Apartments. The trail will require the construction of two bridge crossings, a top down boardwalk section and new retaining wall structures at multiple locations. A 25 foot span bridge is proposed over the existing spillway structure for the existing lake at approximate Station 9. In addition, a retaining wall is proposed near the lift station in this area (Station 7). An approximately 70 foot span bridge crossing is prosed near the club house. An existing granite retaining wall will also be extended near this bridge crossing. A top down boardwalk is proposed along the edge of the lake from approximately Stations 9 to Station 40. Additionally, new retaining walls will be constructed along Cimarron Parkway between Stations 49+50 and 51+50, Stations 52+50 and 53+50 and Stations 58+00 and 59+50.

The site is located in the Northern Piedmont Physiographic Province of Georgia. This

Province is characterized as a broad, gently sloping plateau that decreases in total relief toward the Coastal Plain Province. The Piedmont is intricately dissected by a generally dendritic stream pattern. The topography is generally moderate, but commonly steeper near rivers and small creeks.

According to the mapping of the Georgia Geologic Survey, the rocks that occur in the general vicinity of the site belong to either the Powers Ferry Formation or the Factory

Shoals Formation of the larger Sandy Springs Group and consist primarily of quartz schists, mica schists and amphibolites. This is generally consistent with the partially weathered rock materials encountered in the borings. Overlying these rocks are residual, or in-place, soils that have formed as a result of weathering. This weathering is a function of several factors such as mineral composition of the parent rock and degree of natural fracturing. As a result, these residual soils frequently are highly variable in consistency or relative density. Also, they often contain lenses of highly to partially weathered rock of variable sizes which occur at different depths. Residual soils that retain structural characteristics of the parent rocks, such as color and texture, are known as saprolites.

5. Soil Conditions - Twelve (12) Standard Penetration Test (SPT) borings and seven

(7) hand auger borings were conducted at the approximate locations shown on the attached

Boring Location Plans of Figures 1 through 5.

The borings were performed at the approximate locations requested by the project structural engineer and were located by our field engineer, who supervised the field operations and maintained logs of the borings. The boring logs indicate the depths, consistencies and field classification of the soils encountered during the drilling operations. Groundwater levels and any unusual subsurface conditions, if encountered during the drilling operations, are also described on the logs. Standard Penetration Tests

(SPT) were performed at minimum five-foot intervals in each SPT boring. Split-spoon samples were recovered at these intervals, placed in clean, closed containers, and returned to the laboratory for further analysis.

Two borings were performed for the proposed retaining wall near the existing Fulton

County lift station using hand auger techniques. Borings B-1 and B-1A were performed along the proposed retaining wall alignment, near Station 7+00. The borings encountered similar soils comprised of a surficial stratum of topsoil to a depth of 1 foot underlain by undisturbed residual soils. The residual soils were generally comprised of firm, moist

SILTS with a trace of rock fragments to depth of approximately 1.5 to 3 feet where the borings refused on rock fragments. Offset borings were performed along the top of the existing embankment, as well as along the base where recent grading activities removed a portion of the existing slope, with hand auger refusal at shallow depths due to rock fragments.

Three borings were performed for the bridge which will span over the existing spillway and an adjacent boring for the top down boardwalk abutment; borings B-2 and B-3 were performed on the north side of the crossing and encountered similar soils. Boring B-2 was performed approximately 46 inches from the back face of the existing spillway wall.

This boring encountered fill soils comprised of soft SILTS and loose SANDS to a depth of approximately 32 feet. Underlying these fill soils, a stratum of alluvial soils comprised of loose, wet SANDS were present to a depth of approximately 39.5 feet. These fill and alluvial soils were underlain by hard Partially Weathered Rock to a depth of 45 feet where the boring refused on apparent competent rock. Boring B-3 was located approximately 33 inches from the back face of the existing spillway wall. This boring encountered man-placed fill comprised of soft, moist SILTS to a depth of approximately 10 feet where the boring refused on the footing for the spillway wall.

Borings B-4 and B-5 were performed on the south side of the crossing. Boring B-4, performed approximately 45 inches from the back face of the spillway wall, encountered fill soils comprised of loose to firm SANDS and soft SILTS to a depth of 30 feet where the boring was terminated. Boring B-5 was performed approximately 12 feet from the back face of the spillway wall, at the proposed western abutment for the top down boardwalk.

This boring encountered fill soils comprised of loose Sands and firm SILTS to a depth of approximately 32 feet. These fill soils were underlain by alluvial soils comprised of loose, wet SANDS to a depth of 36 feet. These fill and alluvial soils were underlain by hard

Partially Weathered Rock to a depth of 39 feet where the boring refused on apparent competent rock.

Borings B-6, B-16, B-17 and B-18 were performed for the proposed boardwalk. Boring B-

6 was performed near the eastern abutment of the boardwalk. This boring encountered a surficial stratum of fill consisting of firm SANDS and SILTS to a depth of 6 feet.

Saprolitic soils comprised of firm, Rocky SANDS were encountered from a depth of 6 to

10 feet where the boring refused on rock. Borings B-16, B-17 and B-18, were performed between Stations 38+00 and 40+00 using a hand auger. These borings encountered similar soils generally consisting of an upper stratum of fill comprised of soft to firm SILTS and

SANDS to depths of approximately 1.5 to 2 feet. Underlying these fill soils, a stratum of firm Saprolitic SILTS were penetrated to the boring termination depths of 3 to 6 feet below existing grades.

Boring B-7 was performed for the proposed retaining wall, near the clubhouse. An existing granite retaining wall in this area will be extended to the new abutment for the bridge crossing. This boring encountered a stratum of fill to a depth of 3 feet. These fill soils were underlain by a stratum of alluvial soils comprised of Rocky SANDS to a depth of approximately 3.5 feet where the boring refused on rock fragments. An offset boring performed near the base of the slope below the wall refused on apparent competent rock at a depth of 4 feet.

Borings B-8 and B-9 were performed for the proposed bridge crossing near the clubhouse.

Boring B-8 was performed at the southeastern end of the crossing, near the base of the existing fill embankment, (approximate elev. 834 feet, MSL), using hand auger techniques due to conflicts with existing utilities. This boring encountered a surficial stratum of alluvial soils comprised of loose, moist SANDS to a depth of approximately 1.5 feet.

These alluvial soils were underlain by undisturbed saprolitic soils, comprised of wet, Coarse SANDS to a depth of 3.5 where the boring was terminated due to lack of recovery of soil cuttings caused by the high groundwater conditions.

Boring B-9 was located near the northwestern end side of the proposed bridge crossing and was performed using a drill rig. This boring encountered an upper stratum of fill comprised of firm to stiff, dry to moist SILTS and Sandy SILTS to a depth of 12 feet.

These fill soils were underlain by loose, wet, alluvial SANDS to a depth of 22 feet. The alluvial soils were underlain by saprolitic soils comprised of dense to very dense Silty

SANDS to a depth of 30 feet where the boring was terminated.

Borings B-10 through B-15 were performed for the proposed retaining walls along the eastern side of Cimarron Parkway. Borings B-10, B-11 B-12 and B-14 encountered similar soils conditions. These borings encountered a stratum of rock-laden fill to depths of 2 to 4 feet where the borings refused on large rock fragments or boulders in the fill. Due to the locations of the existing utilities and the narrow area available to set up along the top of the existing fill slope, no offset borings were performed.

Boring B-13, located near Station 53+00, encountered an upper stratum of fill comprised of very soft to soft, moist Silts, to a depth of 6 feet. These fill soils were underlain by saprolitic soils comprised of firm SANDS with a trace to some rock fragments to a depth of 9 feet. Underlying these saprolitic soils, a stratum of hard partially weathered rock was encountered to a depth of 10 feet where the boring refused on rock.

Boring B-15, located near Station 59+00 encountered an upper stratum of fill comprised of soft to firm, moist Silts, to a depth of 5 feet. These fill soils were underlain by hard partially weathered rock to a depth of 6 feet where the boring refused on rock.

For specific details of the soil conditions encountered at each boring, please refer to the individual boring logs in Appendix B.

6. Groundwater - The borings were dry augured their full depth in an attempt to locate groundwater levels. Groundwater was only encountered in borings B-2, B-4, B-5, B-7, B-9 and B-13. The depths to groundwater in these borings at the time of drilling are tabulated below:

BORING NO. GW DEPTH (ft) BORING NO. GW DEPTH (ft.)

B-2 10 B-7 1.3

B-4 9.5 B-9 15.4

B-5 11 B-13 7

Groundwater levels are subject to seasonal and climatic fluctuations and can change significantly with time. Groundwater depths should be verified prior to beginning construction operations. The borings were backfilled with soils from the drilling operations following measurements for stabilized groundwater for safety considerations.

SEISMIC DESIGN PARAMETERS

7. Site Class - The project site is located in Sandy Springs, Fulton County, Georgia which employs the 2018 International Building Code® (IBC). As part of this Code, the design of structures must consider dynamic forces resulting from seismic events which are dependent upon the magnitude of the earthquake event, as well as the properties of the soils that underlie the site. As part of evaluating seismic forces, the Code requires the evaluation of the Seismic Site Class, which categorizes the site based upon the characteristics of the subsurface profile within the upper 100 feet of the ground surface.

To define the Site Class for this project, the results of soil test borings drilled for the project site and estimated appropriate soil properties below the base of the borings to a depth of 100 feet, were interpreted, as permitted by the Code. The estimated soil properties were based upon our experience with subsurface conditions in the general site area.

Based upon the SPT N-values recorded during the field exploration, the subsurface conditions within the site are consistent with the characteristics of a Site Class “D” as defined in Table 1613.5.2 of the Code. The associated IBC (2018) probabilistic ground acceleration values and site coefficients for the general site area were using the ASCE

Hazards Tool which incorporates ASCE 7-16 which has been incorporated into the IBC

2018 codes. The data is presented in the table on the following page:

Morgan Falls Connector Phase 2A Ground Motion Values *

Period

(sec)

Mapped MCE

Spectral

Response

Acceleration**

(g)

Site

Coefficients

Adjusted MCE

Spectral

Response

Acceleration

Design

Spectral

Response

Acceleration

0.2 Ss 0.204 Fa 1.6 SMs 0.327 SDs 0.218

1.0 S1 0.089 Fv 2.4 SM1 0.213 SD1 0.142

*2% Probability of Exceedence in 50 years for Latitude 33.964125°N and Longitude 84.373959°W

**At top of bedrock

MCE = Maximum Considered Earthquake

The Site Coefficients, Fa and Fv presented in the above tables were also obtained from the noted USGS webpage, as a function of the site classification and mapped spectral response acceleration at the short (Ss) and 1-second (S1) periods.

Based on Spectral Response Coefficients SDs and SD1 above, the Seismic Design

Category for this site is Category C for Occupancy Categories I, II and III as prescribed by

IBC 2012, Tables 1613.3.5(1) and 1613.3.5(2).

FOUNDATION RECOMMENDATIONS

8. Retaining Wall near Spillway (Station 7) – Borings B-1 & B-1A

Surficial topsoil materials were present to a depth of approximately 1 foot underlain by soft to firm residual Soils to depths of approximately 1.5 to 3 feet where the boring refused on rock fragments. Based on the boring data, we recommend that the retaining wall foundations bear in the residual soils at a minimum depth of 2 feet below the existing ground surface The wall foundations bearing in the firm residual soils may be designed for a maximum allowable soil bearing pressure of 2500 pounds per square foot (psf). It should be noted that some shallow over-excavation of soils may be required to expose suitable soils in some areas. Any over-excavated areas may be backfilled with #57 stone or placed with additional concrete. A weathered rock outcropping is present between borings B-1 and B-1A in the vicinity of the proposed wall. Ripping of weathered rock may be required to remove a portion of these materials for the retaining wall and chipping with a rock hammer or isolated blasting could be required. A recently constructed forced-main sewer line is present within the adjacent sewer easement south of the proposed trail in this area. A review of the sewer profiles provided indicate that this line is less than 10 feet in depth and should not adversely impact the support of the proposed retaining walls in this area.

9. Proposed Bridge Crossing at Spillway – Borings B-2, B-3, B-4 and B-5

Shallow foundations will not adequately support the proposed bridge abutments at the spillway (borings B-2, B-3 & B-4). The borings encountered loose fill associated with the backfill behind the existing spillway walls and underlying alluvial soils to depths in excess of 35 feet. Additionally, groundwater in this area was present in the borings at depths of to

9.5 to 10 feet in the borings. Due to the soft soils conditions and shallow groundwater, we recommend that the abutments be supported on helical piles as outlined below. Based on the boring data, the foundation for the existing spillway walls extends an estimated 36 to

42 inches back from the rear face of the walls in this area. Boring B-3 encountered the footing at a depth of 10 feet below the ground surface, at a distance of 33 inches behind the back face of the wall. Borings B-2 and B-4 were located approximately 46 and 45 inches, respectively behind the north and south spillway walls and missed the foundation.

It should be noted that placement of the piles within the proposed abutment foundations should ensure that the pile helixes miss the spillway foundations.

We recommend that the proposed bridge crossing abutments be supported using a small diameter helical pile system such as Cantsink™ or A.B. Chance™. These piles utilize a helical bearing plate on the end of the anchor, to develop the pile capacity and are hydraulically advanced into firm soils or rock. The pile capacities are dependent on the installation torque or pressures encountered and the pile section. Ultimate pile capacities of up to 50 tons may be achieved for larger piles. The helical pile installation should be monitored by qualified geotechnical personnel in order to help ensure the piles adequately penetrate into the weathered rock materials in order achieve the desired capacities. If a factor of safety of 2.5 or greater is achieved between the allowable design capacities and the estimated field capacities based on the installation torque, a field load test may be omitted. Helical piles should be placed on minimum center to center spacing’s of 3 helix diameters. Based on the boring data, we anticipate that minimum pile depths of 40 feet for the north abutment and 36 feet for the south abutment will be required. The actual pile depths will be dependent on the installation torque to achieve the design capacity and may be deeper.

10. Proposed Boardwalk Station Stations 9 to 40 – Borings B-5, B-6, B-16, B-17 &

B-18

The proposed abutments at each end of the proposed boardwalk may be supported on conventional shallow foundations. Boring B-5, performed for the western boardwalk abutment encountered an upper stratum of fill comprised of loose Sands to a depth of approximately 5.5 feet. These loose sands were underlain by fill soils comprised of firm

Silts. A layer of alluvial Sands was penetrated from approximately 32 to 36 feet, where hard partially weathered rock was encountered. Boring B-6, performed near the east end of boardwalk, encountered fill soils comprised of firm /sands and /Silts to a depth of 6 feet underlain by stiff saprolitic soils. Both the western and eastern boardwalk abutments may be designed for shallow foundations proportioned for an allowable soils bearing pressure of 2000 pounds per square foot. The foundations should bear through any soft surficial soils at minimum depths of 18 inches below the existing grades at the east abutment

(boring B-6) and approximately 5.5 feet at the western abutment (boring B-5), within the firm Fill soils. Alternatively, the abutment may be supported on driven timber piles.

We understand that the portion of the boardwalk along the slope will be constructed from the top down. The borings indicated that the soils along this section of the boardwalk, (B-

16, B-17 and B-18), are comprised of a surficial stratum of fill to depths of 1.5 to 2 feet underlain by undisturbed saprolitic soils. We understand that this portion of the boardwalk will be supported on driven timber piles, typically with a 10 inch butt diameter. These piles will be driven to a minimum depth of 10 feet or to a working capacity of 6 kips, whichever is deeper. Due to the shallow depth to saprolitic soils and the potential for shallow rock or boulders to be encountered, some of the proposed timber piles may be difficult to drive resulting in shallow refusal and possible splitting. If this condition is encountered, a pilot hole may be drilled for the piles. The pilot hole should be a slightly smaller diameter and extend to the bottom bearing elevation of the pile and the piles lightly driven to refusal. It should be noted that excessive driving of the piles may result in bouncing of the timbers on rock and splitting.

11. Retaining Wall near Clubhouse – Boring B-7

Based on the boring data, shallow foundations will adequately support the proposed retaining wall. The retaining wall foundations should bear a minimum of 2 feet below the existing grades in the existing fill soils and be designed for a maximum allowable soil bearing pressure of 2000 pounds per square foot (psf). It should be noted that some shallow over-excavation of soils may be required to expose suitable soils in some areas.

Any over-excavated areas should be placed with additional concrete to avoid potential undermining due to scour. The wall foundation should be adequately protected by rip-rap to prevent scour of the foundations due to the creek flows.

12. Proposed Bridge Crossing at Clubhouse – Borings B-8 and B-9

Shallow foundations are not recommended to support the proposed bridge abutments due to the potential for impacting the adjacent existing culvert and rock wall. The abutment foundations may be supported through the fill and underlying alluvial soils using a small diameter helical pile system such as Cantsink™ or A.B. Chance™. Please reference

Section 9 above for additional information on helical pile installation and design. Based on the boring data, we anticipate that minimum pile depths of 25 to 30 feet will be required. The actual pile depths will be dependent on the installation torque to achieve the design capacity and may be deeper. Due to the existing embankment in the area of the southwest abutment, the foundation may require to be extended to the approximate elevation of the adjacent creek with an abutment wall. The foundation should be adequately protected by rip-rap to prevent scour of the abutment due to the creek flows.

13. Retaining Walls along Cimarron Parkway– Borings B-10, B-11, B-12, B-13 B-14

& B-15

The retaining wall along Cimarron Parkway between approximately Stations 49+50 and

51+50, (boring B-10, B-11 and B-12), is proposed to be a gabion wall. The shorter walls, (borings B-13, B-14 and B-15), are anticipated to be cast-in-place concrete wall. Based on the limited boring data, we recommend that the proposed retaining walls bear on the rock at or near the existing creek level. The retaining wall foundations should be designed for a maximum allowable soil bearing pressure of 3000 pounds per square foot (psf). It should be noted that the two shorter walls will be replacing or are in addition to existing concrete walls already present along the creek. A visual evaluation of these walls indicates that the foundations for the wall between Stations 53 and 54 have been undermined by the existing creek. In addition, two sinkholes are present in the backfill behind the wall indicating that the backfill soils are being washed into the creek, due to the undermining of the footing. We recommend that this retaining wall be replaced by a new retaining wall bearing on the rock at or near the existing creek elevation. The foundations for the new walls should be adequately protected by rip-rap to prevent scour from the creek flows.

MISCELLANEOUS

14. Settlement – Post construction settlements for the bridge crossings supported on helical piles will be negligible. The anticipated post construction settlement of the boardwalk supported on timber piles will also be negligible. Settlement of the proposed boardwalk abutments and retaining walls supported on shallow foundations will be 1 inch or less. It should be noted that if additional fill soils are required behind the boardwalk or bridge abutments for the approach drives to the structures, the weight of this additional fill placed on the existing fill soils will likely induce settlement of the new fill materials. The magnitude of settlements will be dependent upon the proposed depth of fill and the majority of settlement is anticipated to develop within approximately 60 to 90 days.

15. Wall Design Parameters – The proposed retaining walls will be free standing and should be designed for an “active” lateral earth pressure. Any wing walls associated with the bridge crossings are anticipated to be fixed to the structure and should be designed for an “at rest” lateral earth pressure. The active and at rest earth pressure parameters outlined below are based on a wet soil density of 120 pounds per cubic foot (pcf) and an internal soil friction angle Ø of 30°.

Equivalent Fluid Pressure (Active) soil 40 psf per foot of wall height

Equivalent Fluid Pressure (At Rest) soil 60 psf per foot of wall height

Equivalent Fluid Pressure (Passive) soil 220 psf per foot of depth

Coefficient of Friction (Silts) 0.30

Coefficient of Friction (Sands) 0.35

Soil Angle of Internal Friction (Ø) 30°

Soil Cohesion (c) 0

An appropriate factor of safety should be applied to the above parameters. Proper design and performance of the retaining walls and any wing walls for the bridge crossings depend on properly compacted backfill soils and adequate drainage. The proposed walls are anticipated to be backfilled. Where backfill soils are required we recommend that backfill soils be compacted to a minimum of 95% of the maximum Standard Proctor dry density

(ASTM D 698) with a wet density in the range of 110 to 120 pcf. Also, footing drains with proper filtration should be installed.

16. Geotechnical Quality Control - We recommend that the following quality control measures be implemented in an effort to avoid unforeseen project costs or delays:

1. Chattahoochee Consulting Group should review all final construction plans to ensure that the geotechnical recommendations are properly implemented.

2. Evaluation of box culvert and retaining foundation excavations immediately prior backfilling with stone and prior to foundation concrete placement to verify allowable soil bearing pressures.

3. Evaluation of helical pile installations to verify that the design capacities have been achieved and that unanticipated subsurface conditions that may affect the pile capacities are not encountered.

4. Permanent fill slopes should not exceed 2(H):1(V).

5. Embankment fill should be placed in 6 to 8 inch thick loose lifts and compacted to a minimum of 95% of the appropriate maximum Standard

Proctor dry density (ASTM D 698).

17. Consultation - Often, during the final design and/or construction, questions can arise which are not small specifically in the report. These can normally be handled by a brief call or conference with the designers; please feel free to call

APPENDIX A

FIELD PROCEDURES

FIELD EXPLORATION

General. The Boring Plans of Figures 1 through 5 indicates the approximate location of the borings on the subject site. All SPT borings were made with an all-terrain mounted, rotary-type drilling equipment on April 1 and 2, 2021. The hand auger borings were performed on April 12, 2021. The exploration program consisted of approximately 189 linear feet of SPT borings. Detailed logs of the borings are attached.

Sampling Procedures. In these soil materials, Standard Penetration Tests were performed; these provide a measure of the in-situ characteristics of the soil and secure a disturbed sample. In this test, a 2 inch OD, 1.37 inch ID heavy-walled “split tube” sampler is driven into the undisturbed soil at the bottom of the borehole with a drop hammer weighing 140 pounds and having a stroke of 30 inches. It is first seated 6 inches, then driven two additional 6 inch increments. The “Penetration Resistance”, called N, is the number of such blows required to drive the spoon the final 12 inches. It is recorded on the boring logs in the following manner:

(13-12-11) where the figures in parentheses indicate the number of blows required for each 6 inch increment.

In the hand auger borings, Dynamic Cone Penetrometer tests were performed in general accordance with ASTM Special Technical Publication No. 399. These tests provide a measure of the in-situ characteristics of the soils similar to the Standard Penetration Test.

In this test, a 1.5 inch diameter cone on a 1-3/8 inch diameter “E” rod is driven into the undisturbed soil at the bottom of the borehole with a drop hammer weighing 15 pounds and having a fall of 20 inches. It is first seated 2 inches, then driven an additional 1.75 inch increment. The “Penetration Resistance”, called N, is the number of such blows required to drive the cone the final 1.75 inches. It is recorded on the boring logs in the following manner:

(10-12) where the figures in parentheses indicate the number of blows required for each 2 and

1.75 inch increment, respectively.

APPENDIX B

BORING LOGS

LOG of BORING

Project Name: Morgan Falls Conn Phase 2A Project No.: 4976.001.21

Client: KAIZEN COLLABORATIVE Boring No.: B-1

Location: Edgewater Apartments Date: 4/1/2021

Elevation Description Depth Samples Drilling Observations G.S. Topsoil: 6" (feet) No. Type Blows/Increment Hand Auger Boring

TOPSOIL No groundwater encountered at the time of drilling.

sand, mica, trace rock 1.0 * Note DCP values are higher fragments, moist, low 1 DCP 4-11* due to rock fragment.

plastic, RESIDUAL Note: 3 boring offsets with

Auger Refusal at 1.3 feet auger refusal at ~ 1 foot.

2.0

Boring offset to base of slope, ~ 6 to 7 vertical foot height, 3 boring offsets with auger refusal at ~ 1 foot.

3.0 Hand auger refusals on rock fragments.

4.0

5.0

6.0

7.0

8.0

9.0

LEGEND

DCP=Dynamic Cone Penetrometer

10.0 GS= Ground Surface

SILT, firm, brown, tan, some

Client: KAIZEN COLLABORATIVE Boring No.: B-1A

Location: Edgewater Apartments Date: 4/1/2021

Elevation Description Depth Samples Drilling Observations G.S. Topsoil: 12" (feet) No. Type Blows/Increment Hand Auger Boring

TOPSOIL No groundwater encountered at the time of drilling.

1.0 Boring offset to base of slope, ~ vertical 3 foot height.

Note: 3 boring offsets top of slope

1 DCP 3-4 with auger refusal at ~ 1 foot.

2.0 plastic, RESIDUAL 2 DCP 25+* * Note DCP values are higher due to rock fragment.

Hand auger refusals on rock

3.0 fragments.

Auger Refusal at 3 feet

4.0

5.0

5 DCP 6-7

6.0

6 DCP 9-9

7.0 Hand Auger refusal at 7 feet on

Auger Refusal at 7 feet rock fragment.

8.0

9.0

LEGEND

DCP=Dynamic Cone Penetrometer

10.0 GS= Ground Surface

SILT, soft to firm, brown, tan, fragments, moist, low some sand, mica, trace rock

Client: KAIZEN COLLABORATIVE Boring No.: B-2

Location: Edgewater Apartments Date: 4/1/2021

Elevation Description Depth Samples Drilling Observations

Topsoil: 0" (feet) No. Type Blows/6" Recov. SPT Boring

Fill: Sandy SILT, very soft to 1 SS 2-1-2 Groundwater was measured at soft, brown, trace mica, moist a depth of 10 feet at the time low plastic of drilling.

5.0 2 SS 2-2-3

3 SS 2-3-7* * Note SPT values are higher

Fill: Silty SAND, very loose to due to rock fragment.

loose, brown, red, trace mica, rock fragments, moist to wet, 10.0 4 SS 7-1-3 Boring located 46" from back low plastic face of spillway wall.

Fill: SILT, firm, orange, brown, 15.0 5 SS 5-3-2 tan, some sand, trace mica, clay, wet, low plastic, mottled

20.0 6 SS 3-3-3

Fill: Silty SAND, firm to loose, 25.0 7 SS 3-5-7 grey, white, trace mica, wet, low to non plastic

30.0 8 SS 3-2-4

SAND, loose, grey, brown, wet, non plastic, ALLUVIAL 35.0 9 SS 2-3-4

40.0 10 SS 10-11-50/5"

45.0 11 SS 50/2"

Auger Refusal @ 45 ft.

LEGEND

SPT= Standard Penetration Test

50.0 SS = Split-Spoon (sample)

UDS= Undisturbed Sample

GS= Ground Surface

HWR= Highly Weathered Rock

PWR= Partially Weathered Rock

GS

PARTIALLY WEATHERED ROCK

Client: KAIZEN COLLABORATIVE Boring No.: B-3

Location: Edgewater Apartments Date: 4/1/2021

Elevation Description Depth Samples Drilling Observations

Topsoil: 0" (feet) No. Type Blows/6" Recov. Auger Boring

Fill: Sandy SILT, very soft to No groundwater encountered soft, brown, trace mica, moist at the time of drilling.

low plastic

5.0 Boring located 33" from back

face of spillway wall.

Auger Refusal at 10 feet on top of the spillway footing.

10.0

Spillway wall is 12" thick and

Auger Refusal @ 10 ft. 10 feet in height.

15.0

20.0

25.0

30.0

35.0

40.0

45.0

Auger Refusal @ 10 ft.

LEGEND

SPT= Standard Penetration Test

50.0 SS = Split-Spoon (sample)

UDS= Undisturbed Sample

GS= Ground Surface

HWR= Highly Weathered Rock

PWR= Partially Weathered Rock

Client: KAIZEN COLLABORATIVE Boring No.: B-4

Location: Edgewater Apartments Date: 4/1/2021

Elevation Description Depth Samples Drilling Observations

Topsoil: 0" (feet) No. Type Blows/6" Recov. SPT Boring

Fill: Silty SAND, very loose to 1 SS 3-1-2 Groundwater was measured at loose, brown, trace mica, rock a depth of 9.5 feet at the time fragments, moist, low plastic of drilling.

5.0 2 SS 2-2-3

3 SS 2-1-1 Boring located 45" from back face of spillway wall.

Fill: Sandy SILT, soft, grey, 10.0 4 SS 2-2-2 Spillway wall is 12" thick and brown, some mica, moist 10 feet in height.

low plastic

Fill: SILT & SAND, loose to firm, 15.0 5 SS 5-3-3 grey, white, trace mica, wet, low to non plastic

20.0 6 SS 32-4-4

25.0 7 SS 5-4-7

30.0 8 SS 4-5-9

Boring Terminated @ 30 ft.

35.0

40.0 10 SS 50/2"

45.0

LEGEND

SPT= Standard Penetration Test

50.0 SS = Split-Spoon (sample)

UDS= Undisturbed Sample

GS= Ground Surface

HWR= Highly Weathered Rock

Client: KAIZEN COLLABORATIVE Boring No.: B-5

Location: Edgewater Apartments Date: 4/1/2021

Elevation Description Depth Samples Drilling Observations

Topsoil: 0" (feet) No. Type Blows/6" Recov. SPT Boring

Fill: Silty SAND, very loose to 1 SS 1-3-3 Groundwater was measured at loose, brown, trace mica, a depth of 11 feet at the time moist, low plastic of drilling.

5.0 2 SS 2-2-2

3 SS 3-3-4 Boring located 12 feet from Fill: Sandy SILT, firm, grey, back face of spillway wall.

brown, trace mica, moist low plastic 10.0 4 SS 3-4-4

Fill: Silty SAND, firm to loose, 15.0 5 SS 9-6-7 grey, white, trace mica, wet, low to non plastic

20.0 6 SS 4-6-8

25.0 7 SS 4-3-3

30.0 8 SS 4-4-7

SAND, firm, grey, brown, wet, non plastic, ALLUVIAL 35.0 9 SS 2-9-21

40.0 10 SS 50/2"

Auger Refusal @ 39 ft.

45.0

LEGEND

SPT= Standard Penetration Test

50.0 SS = Split-Spoon (sample)

UDS= Undisturbed Sample

GS= Ground Surface

HWR= Highly Weathered Rock

PWR= Partially Weathered Rock

Client: KAIZEN COLLABORATIVE Boring No.: B-6

Location: Edgewater Apartments Date: 4/2/2021

Elevation Description Depth Samples Drilling Observations

Topsoil: 8" (feet) No. Type Blows/6" Recov. SPT Boring

Fill: Sandy SILT, firm, red trace mica, rock frags, moist, 1 SS 3-2-3 No groundwater was present at non-plastic at the time of drilling.

Fill: SILT & SAND, firm, red brown, some rock frags, trace 5.0 2 SS 4-7-6 wood, dry to moist, non-plastic

3 SS 10-11-10

ROCK FRAGMENTS & SAND,

firm, gray, brown, dry, non-plastic, mottled: SAPROLITE 10.0 4 SS 13-8-8

Auger Refusal @ 10 ft.

15.0

20.0

25.0

30.0

35.0

40.0

45.0

LEGEND

SPT= Standard Penetration Test

50.0 SS = Split-Spoon (sample)

UDS= Undisturbed Sample

GS= Ground Surface

HWR= Highly Weathered Rock

Client: KAIZEN COLLABORATIVE Boring No.: B-7

Location: Edgewater Apartments Date: 4/13/2021

Elevation Description Depth Samples Drilling Observations G.S. Topsoil: 0" (feet) No. Type Blows/Increment Hand Auger Boring

FILL: Silty SAND, loose, No groundwater encountered at brown, trace rock topsoil, the time of drilling.

moist, non-plastic

1.0 Boring offset to base of existing

wall with auger refusal at 3.5 ft.

Hand auger refusal on rock fragments.

2.0 Boring offset to base of slope, with auger refusal at 4 ft.

Hand auger refusal on rock.

3.0

SAND, loose, brown, tan, trace to some rock frags, moist to wet: ALLUVIAL

Auger Refusal at 3.5 feet 4.0

5.0

6.0

7.0

8.0

9.0

LEGEND

DCP=Dynamic Cone Penetrometer

Client: KAIZEN COLLABORATIVE Boring No.: B-8

Location: Edgewater Apartments Date: 4/13/2021

Elevation Description Depth Samples Drilling Observations G.S. Topsoil: 0" (feet) No. Type Blows/Increment Hand Auger Boring

SAND, very loose, brown, Groundwater measured at a depth of 16 inches at the time of drilling.

1.0

Boring was performed at the base of existing slope.

Hand auger refusal due to boring yellow, black, wet, non- 2.0 cave-in.

plastic: SAPROLITE

3.0

Auger Refusal at 3.5 feet

4.0

5.0

6.0

7.0

8.0

9.0

LEGEND

DCP=Dynamic Cone Penetrometer

10.0 GS= Ground Surface

wet, non-plastic: ALLUVIAL

Coarse SAND, loose, brown, Client: KAIZEN COLLABORATIVE Boring No.: B-9

Location: Edgewater Apartments Date: 4/2/2021

Elevation Description Depth Samples Drilling Observations

Topsoil: 10" (feet) No. Type Blows/6" Recov. SPT Boring

Fill: Sandy SILT, firm, red 1 SS 3-3-4 Groundwater was measured at brown, gray, trace mica, a depth of 15.4 feet at the time rock frags, topsoil, moist, of drilling.

non-plastic 5.0 2 SS 3-4-4

3 SS 2-3-5

FILL: SILT, stiff, tan, gray, some mica, sand, dry, 10.0 4 SS 5-4-5 non-plastic

SAND, loose, dark gray, trace silt, wet, non-plastic: 15.0 5 SS 7-6-6

ALLUVIAL

20.0 6 SS 2-1-5

Silty SAND, dense to very dense, black, white, trace 25.0 7 SS 12-21-25 rock frags, wet, non-plastic, mottled: SAPROLITE

30.0 8 SS 11-17-37

Boring Terminated @ 30 ft.

35.0

40.0

45.0

LEGEND

SPT= Standard Penetration Test

50.0 SS = Split-Spoon (sample)

UDS= Undisturbed Sample

GS= Ground Surface

HWR= Highly Weathered Rock

Client: KAIZEN COLLABORATIVE Boring No.: B-10

Location: Edgewater Apartments Date: 4/2/2021

Elevation Description Depth Samples Drilling Observations

Topsoil: 0" (feet) No. Type Blows/6" Recov. SPT Boring

Fill: Rock-ladened SILT, brown, moist, non-plastic No groundwater was present at at the time of drilling.

Auger Refusal @ 2 ft.

5.0

10.0

15.0

20.0

25.0

30.0

35.0

40.0

45.0

LEGEND

SPT= Standard Penetration Test

50.0 SS = Split-Spoon (sample)

UDS= Undisturbed Sample

GS= Ground Surface

HWR= Highly Weathered Rock

Client: KAIZEN COLLABORATIVE Boring No.: B-11

Location: Edgewater Apartments Date: 4/2/2021

Elevation Description Depth Samples Drilling Observations

Topsoil: 0" (feet) No. Type Blows/6" Recov. SPT Boring

Fill: Rock-ladened SILT, brown, moist, non-plastic No groundwater was present at at the time of drilling.

Auger Refusal @ 2 ft.

5.0

10.0

15.0

20.0

25.0

30.0

35.0

40.0

45.0

LEGEND

SPT= Standard Penetration Test

50.0 SS = Split-Spoon (sample)

UDS= Undisturbed Sample

GS= Ground Surface

HWR= Highly Weathered Rock

Client: KAIZEN COLLABORATIVE Boring No.: B-12

Location: Edgewater Apartments Date: 4/2/2021

Elevation Description Depth Samples Drilling Observations

Topsoil: 0" (feet) No. Type Blows/6" Recov. SPT Boring

Fill: Rock-ladened SILT, brown, moist, non-plastic No groundwater was present at at the time of drilling.

Auger Refusal @ 3 ft. 5.0

10.0

15.0

20.0

25.0

30.0

35.0

40.0

45.0

LEGEND

SPT= Standard Penetration Test

50.0 SS = Split-Spoon (sample)

UDS= Undisturbed Sample

GS= Ground Surface

HWR= Highly Weathered Rock

Client: KAIZEN COLLABORATIVE Boring No.: B-13

Location: Edgewater Apartments Date: 4/2/2021

Elevation Description Depth Samples Drilling Observations

Topsoil: 0" (feet) No. Type Blows/6" Recov. SPT Boring

Fill: Sandy SILT, very soft to 1 SS 1-1-2 Groundwater was measured at soft, brown, moist, non-plastic a depth of 7 feet at the time of drilling.

5.0 2 SS w.o.h-2

SAND, firm, gray, brown, some 3 SS 11-5-9 to trace rock frags, dry, non-plastic, mottled: SAPROLITE

10.0 4 SS 29-50/4"

Auger Refusal @ 10 ft.

15.0

20.0

25.0

30.0

35.0

40.0

45.0

LEGEND

SPT= Standard Penetration Test

50.0 SS = Split-Spoon (sample)

UDS= Undisturbed Sample

GS= Ground Surface

HWR= Highly Weathered Rock

PWR= Partially Weathered Rock

Client: KAIZEN COLLABORATIVE Boring No.: B-14

Location: Edgewater Apartments Date: 4/2/2021

Elevation Description Depth Samples Drilling Observations

Topsoil: 0" (feet) No. Type Blows/6" Recov. SPT Boring

Fill: Sandy SILT, soft , brown, 1 SS 2-2-2 No groundwater was present at white, trace mica, moist, at the time of drilling.

non-plastic

5.0 Boring terminated due to

Boring Terminated @ 4 ft. possible utility conflict.

10.0

15.0

20.0

25.0

30.0

35.0

40.0

45.0

LEGEND

SPT= Standard Penetration Test

50.0 SS = Split-Spoon (sample)

UDS= Undisturbed Sample

GS= Ground Surface

HWR= Highly Weathered Rock

Client: KAIZEN COLLABORATIVE Boring No.: B-15

Location: Edgewater Apartments Date: 4/2/2021

Elevation Description Depth Samples Drilling Observations

Topsoil: 0" (feet) No. Type Blows/6" Recov. SPT Boring

Fill: Sandy SILT, soft to firm, 1 SS 2-2-2 No groundwater was present at brown, trace rock frags, wet, at the time of drilling.

non-plastic

5.0 2 SS 3-3-6

PARTIALLY WEATHERED ROCK

Auger Refusal @ 6 ft.

10.0

15.0

20.0

25.0

30.0

35.0

40.0

45.0

LEGEND

SPT= Standard Penetration Test

50.0 SS = Split-Spoon (sample)

UDS= Undisturbed Sample

GS= Ground Surface

HWR= Highly Weathered Rock

Client: KAIZEN COLLABORATIVE Boring No.: B-16

Location: Edgewater Apartments Date: 4/13/2021

Elevation Description Depth Samples Drilling Observations G.S. Topsoil: 8" (feet) No. Type Blows/Increment Hand Auger Boring

FILL: SILT & SAND, soft, No groundwater encountered at brown, black, trace roots, the time of drilling.

topsoil, moist, low plastic 1.0

2.0

Sandy SILT, firm to stiff, red, brown, black, trace mica, rock, roots, dry, non-plastic, mottled: 3.0

SAPROLITE

4.0

5.0

Boring Terminated @ 5 ft.

6.0

7.0

8.0

9.0

LEGEND

Client: KAIZEN COLLABORATIVE Boring No.: B-17

Location: Edgewater Apartments Date: 4/13/2021

Elevation Description Depth Samples Drilling Observations G.S. Topsoil: 6" (feet) No. Type Blows/Increment Hand Auger Boring

FILL: SILT & SAND, soft, No groundwater encountered at brown, black, trace roots, the time of drilling.

topsoil, moist, low plastic

1.0 Hand auger refusal on tree roots.

FILL: Sandy SILT, firm, 2.0 brown, black, some roots, trace mica, rock frags, moist, low plastic

3.0

Auger Refusal at 3 feet

4.0

5.0

6.0

7.0

8.0

9.0

LEGEND

Client: KAIZEN COLLABORATIVE Boring No.: B-18

Location: Edgewater Apartments Date: 4/13/2021

Elevation Description Depth Samples Drilling Observations G.S. Topsoil: 8" (feet) No. Type Blows/Increment Hand Auger Boring

No groundwater encountered at brown, black, trace roots, the time of drilling.

topsoil, moist, low plastic 1.0

2.0

Sandy SILT, firm to stiff, red, brown, black, trace mica, rock, roots, dry, non-plastic, mottled: 3.0

SAPROLITE

4.0

5.0

6.0

Boring Terminated @ 6 ft.

7.0

8.0

9.0

LEGEND

DCP=Dynamic Cone Penetrometer

FILL: SILT & SAND, loose,