15-Report File.pdf

Storm Water Quality Management Plan

Developed For:

Seabrook Sports Complex Parking Lot – 2023 – Precinct 2

UPIN: 24102MF3CC01

Harris County Engineering Department

1001 Preston, 7th Floor Houston, TX 77002

Prepared by:

infraTECH Engineers & Innovators, LLC 11111 Wilcrest Green Dr, Houston, TX 77042

Suite 410 p:\watershed protection\stormwater group\plan review\forms\2015 draft changes\swq as-built certificate 3.20.15.docx Revised 10/04/05

STORMWATER QUALITY PERMIT

AS-BUILT CERTIFICATE

I, ____________________________________, a registered Professional Engineer

(Name) duly licensed to practice in the State of Texas do hereby certify that the

____________________________________________________, constructed at (Storm Water Quality Features) ______________________________________________, under Permit Number (Project Named on Permit)

_______________________, were completed in accordance with the drawings and (Storm Water Quality Permit#) specifications on file with the Harris County Engineering Department.

S E A L

Signature Date

Mailing Address City, Zip

Phone No.

1.4 Total Site Areas and Affected Area

The total acreage of Seabrook Sports complex is approximately 10.8 acres. Only approximately

1.3 acres are going to be disturbed during construction. The impervious area that will be added during construction is approximately 5,250 square feet.

1.5 Wetlands, Surface Waters and Storm Water Discharge Locations

The nearest discharge location for the project is Clear Lake. The MS4 operators will be Harris County Precinct 2.

2.0 Controls: Structural & Non-Structural:

2.1 Non-Structural:

Non-structural controls are management-based activities that are designed to prevent or reduce the potential of storm water runoff contact with pollution-causing activities. Various non-structural controls will be used, including:

• Training and Educational Programs

• Proper Landscaping Practices

• Proper Fertilizer & Pesticide Use

• Proper Vehicle Equipment Fueling and Washing Practices

• Good Housekeeping and Sanitary Waste Disposal

All non-structural controls will be used in accordance with the County’s Standard Maintenance and Operating Procedures.

2.2 Structural:

Structural controls are constructed facilities or vegetative practices that are designed to reduce pollutant levels in storm water runoff. For this project, structural controls include a permeable pavement that shall produce a proper filtration rate prior to operation, erosion control logs, tree protecting fences, and temporary erosion control fences. A detailed description of the permanent storm water quality feature and the calculations used to determine its design might be found in Appendix “C”. Once the project is completed, final inspection of the SWQ Feature must be requested by sending time and date stamp photos to the watershed protection SWQ Field Manager at hcedswqgovinspect@harriscountytx.gov.

3.0 Inspection & Maintenance:

3.1 Procedure: The pervious parking lot and grass area will be visually inspected and maintained to ensure the successful function of the SWQMP. Routine maintenance will include activities such as general landscaping, mowing, and watering. Trash will be collected and properly disposed of as needed. Various other maintenance activities will include:

• Watering of plant material

• Mowing and litter/debris removal

• Fertilizer and pesticide use management

• Repair of eroded or sparsely vegetated areas

• Seeding or sodding to restore ground cover

All inspection and maintenance activities will occur in accordance with the County’s Standard Maintenance and Operating Procedures.

Appendix A

Vicinity Map

Appendix B:

SWPPP Site Plan

PROJECT NAME:

PROJECT SCOPE:

Concrete

Fertilizer

Pesticides

Asphalt

Paint

Gasoline

Diesel Fuel

Sanitary Toilets

Cleaning Solvents

Curing Compounds

Hydraulic Fluid

Motor Oil

LOCATION & LIMITS:

Activity (check all that apply)

Roadway Expansion

Roadway New Construction

Underground Storm Sewer

Detention Pond

Bridge Expansion

Bridge New Construction

TOTAL AREA DISTURBED*: Acres

EXISTING CONDITIONS OF SOIL, VEGETATION, AND DRAINAGE:

STORM WATER POLLUTION PREVENTION PLAN

PHASED CONSTRUCTION ACTIVITIES:

TOTAL PROJECT AREA: Acres Linear Feet

ACTIVITY (CHECK ALL THAT APPLY)

SPEC 100 - Preparing Right-of-Way

SPEC 104/110/400 - Excavating

SPEC 400 - Fill

Leveling/Grading

DESCRIPTION OF DRAINAGE AREAS AND OUTFALLS:

RECEIVING WATERS/CONVEYANCE:

NOTES:

Current construction specification documents can be found at:

http://www.eng.hctx.net/Consultants/Standards-Specifications/Standard-Engineering-Design-Specifications

MEASURES

SPEC 164 - Hydro-mulch

SPEC 591 - Construction Exit

SPEC 591 - Concrete Truck Washout Structures

TEMPORARY PERMANENT

SOIL STABILIZATION AND SEDIMENT CONTROL MEASURE:

If sediment escapes off site, these accumulations will be removed to minimize impact. Rock filter dams areas. If prompt repair or replacement is not feasible, the reason will be documented in the SWPPP.

will be cleared before the reach 1/3 the height of the dam, other control measures will be cleared before

Records of dates for major grading activities, and initiation of stabilization measures will be maintained measures will be initiated in portions of the site where activities have ceased for a period exceeding

14 days. This stabilization will commence no later than the day following completion of work in these in the SWPPP. Daily work logs related to this section will be kept in CAPTRAC. The Harris County SWPPP detail sheet will be used when implementing BMP's and included with this document.

INSPECTION & MAINTENANCE:

Inspection and Maintenance will be performed according to SPEC 591. Inspections will be conducted at least every 7 calendar days. Inspection forms will be filed with SWPPP supporting documents. If repair or replacement of stabilization or erosion control features is necessary, it must be completed at the earliest date possible. Amendments will be tracked on the SWPPP Amendment Log. Daily work logs related to this section will be

POTENTIAL POLLUTION SOURCES:

POLLUTION PREVENTION BMPS

Whenever possible all materials will be stored in their original containers in secure areas where spillage is protected from runoff. Stockpiles and work areas will be constructed in such a way to minimize the amount of sediment that enters receiving waters and wetlands. Spill prevention and control measures are included on attached site maps.

Records of spills will be maintained with SWPPP supporting documents. Additional required

BMPs can be found in SPEC 591. Temporary materials and structures will be removed from waterways as soon as feasible once they are no longer required.

WASTE MATERIAL:

All solid waste materials will be collected and stored in secure metal dumpsters, then transported to appropriate disposal facilities. Collection will be completed often enough to ensure that no waste materials will be lost due to overfilling of collection containers.

Liquid wastes will be stored in sealed containers in designated areas and disposed of according to all applicable regulations. All wasted containers should meet all state and

Name

Title

Company

Signature

RESPONSIBLE PARTY/CONTRACTOR

kept in current construction management system.

Is Receiving Waters listed on the current TCEQ 303(d) list?

MAJOR SOIL DISTURBING ACTIVITIES:

local requirements.

See plan cover sheet for vicinity map.

See Site Plan for detailed planning drawings.

NOTES:

(*Note: Include estimated need for project trailer and laydown yards.)

No . Yes, if yes list impairment

1805 N MEYER AVE, SEABROOK, TX 77586

PROPOSED PARKING LOT AND SIDEWALK

1.29

4801.31

ALONG N MEYER RD. THE DITCH RUNS INTO AN UNDERGROUND DRAINAGE SYSEM.

THE CURRENT DRAINAGE SYSTEM IS SERVED BY AN OPEN DITCH AND AN UNDERGROUND DRAINAGE

SYSTEM. THE DITCHES PROVIDE PROPER DETENTION IN THE EVENT OF HIGH RAINFALL EVENTS. THE

PROPOSED PARKING LOT WILL PROVIDE UNDERGROUND WATER DETENTION USING A TRUEGRID

PAVEMENT SYSTEM OR AN EQUIVALENT. THE DRAINAGE WILL BE IMPROVED TO DETAIN STORM WATER

DURING A 2-YEAR STORM EVENT.

SPEC 591 - Temporary Sediment-Control Fence

SPEC 591 - Biodegradable Erosion Control Logs

2023 - PRECINCT 2

SEABROOKS SPORTS COMPLEX - PARKING LOT -

OF LEAN AND FAT CLAYS. THE AREA DRAINS INTO AN EXISTING DITCH RUNNING NORTH TO SOUTH

THE CURRENT PARKING AREA HAS GRASS, SOME 3.5" ASPHALT, GRAVEL, AND DIRT. THE SOIL CONSISTS

AN APPROXIMATELY 38,120 SQ. FT. PARKING LOT WILL BE BUILT IN THE AREA. THEN THE DITCH

WILL BE REGRADED AND ADDITIONAL UNDERGROUND DRAINAGE WILL BE BUILT ALONG

N MEYER AVE.

SW3P WORK FORM

HARRIS COUNTY IS THE MS4 OPERATOR.

DRAWN BY:

DESIGN BY: SCALE:

DATE:

NO. REVISIONS DATE NAME PROJECT TITLE:

HARRIS COUNTY

ENGINEERING DEPARTMENT

SHEET DESCRIPTION:

SHEET NO:

HOUSTON, TEXAS 77042

11111 WILCREST GREEN DR, SUITE 410

7/7/2025

TBPE REGISTRATION NO. F-18368

infraTECH Engineers & Innovators, LLC

NONE

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T PARKING LOT - 2023 - PRECINCT 2

SEABROOK SPORTS COMPLEX

Appendix C:

SWQMP Site Plan:

Appendix D:

SWQMP Construction Details, Calculations (and/or Worksheets):

DRAWN BY:

DESIGN BY: SCALE:

DATE:

NO. REVISIONS DATE NAME PROJECT TITLE:

HARRIS COUNTY

ENGINEERING DEPARTMENT

SHEET DESCRIPTION:

SHEET NO:

HOUSTON, TEXAS 77042

11111 WILCREST GREEN DR, SUITE 410

7/7/2025

TBPE REGISTRATION NO. F-18368

infraTECH Engineers & Innovators, LLC

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T PARKING LOT - 2023 - PRECINCT 2

SEABROOK SPORTS COMPLEX

1" = 20' (FULL) 1" = 40' (HALF)

STORM SEWER COMPUTATIONS

RAINFALL EVENT

RUNOFF COMPUTATIONS FOR 2-YEAR

DRAINAGE CALCULATIONS

7/7/2025

S T

A

TE

OF TEX

A S

L I

CENSE

D

P R

O F

E S S

IONAL E

NG

I

N E

E R

SYED S. HAQ

94660

ID

TCOEFFICIEN

RUNOFF

(AC)AREA

DRAINAGE

(MIN)

CONCENTRATION

OFTIME

(IN/HR)

INTENSITY

RAINFALL

(CFS)FLOW

A1 0.21 0.122 10.00 5.71 0.15

A2 0.20 0.142 10.00 5.71 0.17

A3 0.21 0.099 10.00 5.71 0.12

A4 0.21 0.099 10.00 5.71 0.12

A5 0.21 0.100 10.00 5.71 0.12

A6 0.21 0.099 10.00 5.71 0.12

A7 0.31 0.134 10.00 5.71 0.24

A8 0.25 0.125 10.00 5.71 0.18

B1 0.31 0.291 10.00 5.71 0.51

B2 0.42 0.104 10.00 5.71 0.25

B3 0.58 0.235 10.79 5.55 0.75

B4 0.31 0.349 18.29 4.40 0.48

B5 0.20 0.436 34.44 3.14 0.27

0.7244 = e min, 9.07 = d in., 48.35 = b COEFFICIENTS:2-YEAR

ID

ID

UPSTREAM

ID

DOWNSTREAM

TYPE SIZE

(FT)

LENGTH

nMANNING'S (%)SLOPE

(CFS)

CAPACITY

DESIGN

(FT/S)

VELOCITY

DESIGN

)(FT

FALL

(FT)

UPSTREAM

ELEVATION

PIPE OFTOP

(FT)

DOWNSTREAM

ELEVATION

PIPE OFTOP

(FT/S)

VELOCITY

ACTUAL

(FT)

LOSS

FRICTION

)(FT

HEAD

INCHANGE

(FT)

UPSTREAM

GRAD.HYD.

OFELEVATION

(FT)

DOWNSTREAM

GRAD.HYD.

OFELEVATION

1CULVERT B4 B3 RCP 18" -2 48.0 0.012 0.63 18.04 5.10 - 7.82 7.52 3.33 0.00 0.17 7.69 7.52

2CULVERT B3 B2 RCP 24" 76.0 0.012 0.83 22.39 7.13 - 7.37 6.74 4.62 0.01 0.34 6.94 6.60

3CULVERT B2 B1 RCP 24" 68.5 0.012 0.67 20.11 6.40 0.01 6.73 6.27 4.45 0.01 0.32 6.59 6.27

Vwq = (P/12)*A

P (inches) = 1

A (ft ) = 38,120

Vwq (ft ) = 3,176.67 k = (i*24)/24 i (in/hr) = 30 k = 30

Af = Vwq*Df/[k*(H+Df)(Tf)]

Df (ft) = 1

H (ft) = 0

Tf (days) = 1

Af (ft ) = 105.89

Water Quality Volume Calculations

GEOTECHNICAL INVESTIGATION

SEABROOK SPORTS COMPLEX, PARKING LOT - 2023

UPIN # 24102MF3CC01

HARRIS COUNTY, TEXAS

REPORT NO. 1140295801

Prepared for:

INFRATECH ENGINEERS & INNOVATORS, LLC.

Houston, Texas

Submitted by:

GEOTEST ENGINEERING, INC.

TBPE REGISTRATION NO. F-410

Houston, Texas

April 2, 2025

Key Map No. 620 P & Q

TABLE OF CONTENTS

Page

EXECUTIVE SUMMARY

1.0 INTRODUCTION

1.1 General

1.2 Project Description

1.3 Scope of Work

2.0 SITE EXPLORATION

2.1 Geology

2.2 Faults

3.0 FIELD EXPLORATION

3.1 Soil Boring and Sampling

3.2 Piezometer Installation

3.3 Field Permeability Tests

3.4 Environmental Issues

4.0 LABORATORY TESTING

5.0 SUBSURFACE SOIL AND GROUNDWATER CONDITIONS

5.1 Existing Pavement

5.2 Soil Stratigraphy

5.3 Groundwater Conditions

5.4 Field Permeability Test Locations

6.0 ENGINEERING ANALYSIS AND RECOMMENDATIONS

6.1 General

6.2 Potential Vertical Rise

6.3 Field Infiltration Test Results

6.4 Pavement Recommendations

6.5 Site Preparation and Select Fill Recommendations

7.0 PROVISIONS

ILLUSTRATIONS

Figure

Vicinity Map

Plan of Borings

Log of Borings ...................................................................................................... 3 and 4

Symbols and Terms Used in Boring Logs

APPENDIX A

Site Photos for Field Permeability Tests

APPENDIX B

Information from TrueGrid Pavers

Geotest Engineering, Inc. Report No. 1140295801

Seabrook Sports Complex, Parking Lot April 2, 2025

UPIN #24102MF3CC01

Harris County, Texas

EXECUTIVE SUMMARY

A geotechnical investigation was conducted by Geotest Engineering, Inc., for the Seabrook

Sports Complex Parking Lot Project (Approx. 45,029 sq. ft), located at 1805 N. Meyer Ave. in

Seabrook, Harris County. The proposed improvements include the construction of a Permeable

Parking Lot with True Grid. Additional details of the project are presented in Section 1.2 of this report.

This study included drilling and sampling a total of two (2) soil borings, each to depth of 10 feet and performing two (2) field permeability tests, performing appropriate laboratory tests, performing an engineering analysis and preparing a geotechnical report.

The principal findings and conclusions developed from this study are summarized below:

o Based on the available information from U.S. Geological Survey (USGS) Maps and information contained in house relating to geologic faults, no documented faults cross the project site. Hence, a Phase I Geological Fault Study may not be warranted for this project.

o The existing pavement, as encountered in borings GB-1 and GB-2, consists of 3.5 inches of asphalt.

o As revealed by borings GB-1 and GB-2, the subsurface soils below existing pavement consist of stiff to hard brown and gray, reddish brown and gray, and brown lean clay and fat clay to the explored depth of 10 feet.

o No water was encountered in borings GB-1 and GB-2 drilled for this investigation.

o Recommendations for the proposed parking lot are presented in Section 6.3 of this report.

1.0 INTRODUCTION

1.1 General

A geotechnical investigation was conducted by Geotest Engineering, Inc., for the Seabrook

Sports Complex Parking Lot Project, located at 1805 N. Meyer Avenue in Seabrook, Harris County, Texas.

1.2 Project Description

The project includes the design and construction of a proposed permeable parking lot approximately 45,029 sq. ft. Based on the information provided, we understand that the proposed parking lot will be constructed using TrueGrid permeable paving system to help with detention and impervious cover. A site vicinity map is shown on Figure 1.

1.3 Scope of Work

The purpose of this investigation was to explore the subsurface conditions and to develop geotechnical recommendations pertaining to the design and construction of proposed parking lot in

Seabrook, Precinct 2, Harris County, Texas.

The scope of services consisted of the following:

• Called 811 and coordinated with utility locators to clear the underground utilities.

• Drilled and sampled two (2) soil borings each to a depth of 10 feet.

• Performed two (2) field permeability tests at selected locations as per Rebuild Houston

Guidelines for permeable paving, Attachment E.

• Performed appropriate laboratory tests on selected recovered soil samples to evaluate pertinent geotechnical engineering properties of the soils.

• Performed engineering analyses to develop geotechnical recommendations for the proposed parking area.

• Prepared a geotechnical report summarizing the results of our field investigation, laboratory testing, geotechnical analyses, and providing geotechnical recommendations for the proposed improvements.

2.0 SITE EXPLORATION

2.1 Geology

The geology of Harris County is characterized by two formations. The Beaumont formation is located in the southeastern portion of the county and the Lissie formation is located in the northwest. Both the Beaumont and the Lissie formations are part of the fluvial and marine coastal complex resulting from the glacial cycles within the Pleistocene/Holocene epoch. Seaward, the lithologies are primarily dominated by clays, often interspersed with coarser sediments, primarily silts and sands. Northern portions of Harris County are under the influence of the drainage systems established by rivers such as the Brazos and the San Jacinto. The lithologic pattern generally includes silt, sand and clay with minor amounts of calcareous nodules and iron oxide. Various mineral impregnations are associated with the lithologies. Primary among these are the ferruginous-iron-based and calcareous minerals, which include calcium carbonate. These minerals impart an acidic or alkaline characteristic to soils.

Based on the Houston Sheet of Geologic Atlas of Texas (Bureau of Economic Geology, University of Texas, 1982), the location of the project site is located on the Beaumont Formation.

The clays and sands of this formation are overconsolidated as a result of desiccation or frequent raising and lowering of the sea level and subsequently the groundwater table. Consequently, clays of this formation have moderate to high shear strength and relatively low compressibility. Sands of the

Beaumont Formation are typically very fine and often silty. Further, there is occasional evidence in the Houston area of the occurrence of cemented material (sandstone and siltstone) deposits within the Beaumont Formation.

2.2 Faults

A review of information in the Geotest Library relating to known surface and subsurface geologic faults in the general area of the project site was undertaken. The available information consisted of U. S. Geological Survey and NASA maps, open file reports, and information contained in our files relating to geologic faults in this area.

Based on the available information from U.S. Geological Survey (USGS) Maps and information contained in house relating to geologic faults, no documented faults cross the project site. Hence, a

Phase I Geological Fault Study may not be warranted for this project.

3.0 FIELD EXPLORATION

3.1 Soil Boring and Sampling

Subsurface conditions were explored by drilling a total of two (2) borings each to a depth of

10 feet. The borings were drilled using a tractor mounted drill rig. The location of each boring is shown on the Plan of Borings on Figure 2.

Samples were obtained continuously to the explored depths ranging from 0 to 10 feet.

Cohesive samples were obtained with a 3-inch diameter thin-walled tube sampler in general accordance with ASTM D1587. At each of the boring locations, samples were removed from the sampler in the field and carefully examined and logged by an experienced soils technician. Suitable portions of each sample were then sealed and packaged for transportation to Geotest's laboratory.

Undrained shear strengths of cohesive soil samples were estimated using a calibrated hand penetrometer in the field.

Detailed description of the soils encountered in the borings drilled for the project are presented on the boring logs on Figures 3 and 4. The depth at which water was encountered during drilling is also noted on the boring logs. The terms used on borings logs are presented following the logs of borings on Figure 5. Survey information (Northing, Easting and ground surface elevation) of the drilled borings were not available to us at the time of preparation of this report.

3.2 Piezometer Installation

No piezometers were installed for this investigation.

3.3 Field Permeability Tests

Two (2) field infiltration tests were performed in general accordance with Rebuild Houston

Guidelines permeable pavement section and Attachment E. At each test location, a test hole with 2-foot diameter and 2-foot deep was dug using a shovel. Water was filled to the top and after the water level was stabilized, the initial water level reading was noted. After an hour, the final water level reading was taken. After completion of the tests, the test holes were backfilled with the excavated soils and hand compacted. Approximate test locations designated as B-1 and B-2 are presented on

Figure-2. The photographs taken during the field tests are presented on Appendix A

3.4 Environmental Issues

Based on the field observation and visual examination of soils samples retrieved from the borings, Geotest did not observe any signs of environmental concern during the drilling of soil borings.

4.0 LABORATORY TESTING

The laboratory test program was designed to evaluate the pertinent physical properties and shear strength characteristics of the subsurface soils. Classification tests were performed on selected samples to aid in soil classification. All geotechnical tests were performed in accordance with

ASTM procedures.

The shear strength of cohesive samples was measured in the field with a calibrated hand penetrometer and also in the laboratory with a Torvane. The shear strength values obtained from the penetrometer and Torvane are plotted on the boring logs as open circles and triangles, respectively.

Moisture content measurements (ASTM D2216) were also made on other samples to establish the moisture profile at each boring location. Atterberg limit tests (ASTM D4318) were performed on soil samples to measure plasticity characteristics. Percent passing No. 200 sieve

(ASTM D1140) tests were also performed on selected samples.

5.0 SUBSURFACE SOIL AND GROUNDWATER CONDITIONS

5.1 Existing Pavement

The existing pavement, as revealed by borings GB-1 and GB-2, consists of 3.5 inches of asphalt.

5.2 Soil Stratigraphy

Proposed Parking Area. The subsurface soils for the trail and parking area, as revealed by borings GB-1 and GB-2, the subsurface soils below existing pavement consist of stiff to hard brown and gray, reddish brown and gray, and brown lean clay and fat clay to the explored depth of 10 feet.

The fat clays are of high plasticity with a liquid limit of about 53 and a plasticity index of about 31. The lean clay are of high plasticity with a liquid limit of about 45 and a plasticity index of about 26. The fines content (percent passing # 200 sieve) of fat clay and lean clay ranged from 86.9 to 91.0 percent.

5.3 Groundwater Conditions

No Groundwater was encountered during this study.

5.4 Field Permeability Test Locations

The subsurface soil, encountered at each test location, consists of fill material consisting of brown and gray reddish brown lean clay with sand, gravel and concrete pieces underlain by brown clayey sand to a depth of 24 inches.

6.0 ENGINEERING ANALYSIS AND RECOMMENDATIONS

6.1 General

The project includes the design and construction of a proposed permeable parking lot approximately 45,029 sq. ft. Based on the information provided, we understand that the proposed parking lot will be constructed using TrueGrid permeable paving system to help with detention and impervious cover. The site vicinity map is shown on Figure 1.

6.2 Potential Vertical Rise

Design of the foundation systems for the proposed parking requires consideration of the potential surface heave of the site. Surface heave results from the volumetric expansion of soils as a result of moisture absorption. Volumetric expansion of soils is a function of the type and amount of clay minerals and the physical state of soils (i.e., moisture content and density, or degree of overconsolidation). Just as soils are subjected to expansion, they may also experience shrinkage during periods of dry weather as moisture evaporation occurs at the ground surface and the groundwater table lowers.

Estimates of surface heave, or Potential Vertical Rise (PVR) were computed based on correlations of percent free swell with soil index properties, using TxDOT Test Method Tex-124-E and methods proposed by Vijayvergiya and Ghazzaly (1973) and Vijayvergiya and Sullivan (1972) .

Based on soil plasticity, range of anticipated moisture content, total unit weight profile of the near surface soils at the site, we computed values of PVR for GB-1 ranging from 1.6 to 2.2 inches and values of PVR for GB-2 ranging from 0.9 to 1.7 inches. Since the initial physical state (i.e., moisture content and density) of in-situ soils is the basis for computing the potential for further expansion and resulting ground surface heave, the actual PVR of the site will be highly dependent upon moisture regime of soils at the time of construction. Preserving the moisture contents of near surface very high plasticity clay soils is critical to reduce the potential for excessive surface heave.

6.3 Field Infiltration Test Results

The summary of the infiltration test results are presented as given below.

Field Infiltration Test Results

Location

Hole

Depth(in)

Start time

Final time

Elapsed

Time

(hr.)

Initial

Depth

(in)

Final

Depth

(in)

Hydraulic

Drop

(in)

Infiltration

Rate, (in/hr.)

Test – 1 24 9:30AM 10:30AM 1 22.8 21.2 1.6 1.6(in/hr.)

Test – 2 24 11:00AM 12:00PM 1 19.8 17.2 2.6 2.6(in/hr.)

Since the soils that are encountered in the proposed parking area consists of fat clays which have high swelling potential and the results from field permeability test exhibit that the infiltration rate is lower than standard infiltration rate which is 2.0 inch/hr according to Rebuild Houston

Guidelines Attachment E” the detention needs to be placed for tackling the possible heave that may occur due to swelling of high plasticity cohesive soils, hence it is recommended to remove an additional 6 inches of existing soil and replace with compacted select fill material prior to placing the true grid pavement section.

6.4 Pavement Recommendations

It is our understanding that the True Grid parking lot surface will be used to help with detention and impervious cover in the parking areas.

Based on the standard True Grid section provided by True Grid pavers, the recommended pavement section is given below:

Further, a subsurface drainage system would be needed to manage the storm water due to cohesive subgrade soils encountered at the site. A perforated pipe wrapped in geotextile

(minimum of 8-inch diameter) may be used to direct the subsurface drainage. The typical cross section is shown in Appendix B.

6.5 Site Preparation and Select Fill Recommendations

The site should be cleared of all debris, grubbed and stripped of all vegetation and organic material, soft soils and foreign material from the proposed parking area. Stripped areas should be appropriately graded and shaped to prevent ponding of water on the site. The shallow sandy soils encountered (if any) at the site will become unstable if they are wet. Precautions must be taken to prevent ponding of water at this site, pumping may occur if the site becomes wet. When site becomes wet, the following preparations are recommended:

• Digging temporary ditches to drain the ponding water;

• Removing wet and softened soils to appropriate depths where firm soils are obtained and/or;

• Applying suitable stabilizing agent to the wet soils to accelerate the drying process and to provide a stable working surface/platform.

Pavement Course

Thickness, inches

TRUEGRID Permeable Paving System 1.8

Sub-base (Angular Stone) with perforated pipe embedded

(Reservoir Layer)

10.0

Geotextile Fabric

Compacted Select Fill 6.0

The structural fill required to raise the grade or backfill grub holes should consist of lean clay and sandy lean clay with a liquid limit less than 40 and a plasticity index between 8 and 20. The structural fill should be compacted at moisture content within three percent above optimum to reduce swelling potential of the compacted fill. The fill material should be placed in loose lifts not exceeding eight inches and should be compacted to a minimum of 95 percent of the maximum dry density as determined in accordance with ASTM D698 in driveway area. The onsite high plasticity clay is not suitable for selected fill, unless stabilized with sufficient lime.

7.0 PROVISIONS

The subsurface conditions and design information contained in this report are based on the test borings made at the time of drilling at specific locations. Some variations in soil conditions may exist between test borings. Should any subsurface conditions other than those described in our boring logs be encountered, Geotest should immediately be notified so that further investigation and supplemental recommendations can be provided. The depth to the groundwater level may vary with changes in environmental conditions such as frequency and magnitude of rainfall, as well as area construction activities.

The analysis and recommendations presented in this report are based, in part, upon the data obtained from subsurface explorations made at the time test borings were drilled at specific locations. The stratification lines on the boring logs represent approximate boundaries between soil types. Actual transitions between soil types may be more gradual than depicted.

This report may not be reproduced in whole or part without the written permission of Geotest

Engineering, Inc., and InfraTECH Engineers, Inc.

ILLUSTRATIONS

Figure

Vicinity Map

Plan of Borings

Log of Borings ...................................................................................................... 3 and 4

Symbols and Terms Used in Boring Logs

Geotest Engineering, Inc. FIGURE 1

VICINITY MAP

SEABROOK SPORTS COMPLEX � PARKING LOT � 2023

UPIN #24102MF3CC01

PRECINCT 2, HARRIS COUNTY, TEXAS

KEY MAP NO. 620 P & Q

Jo b

N o

. 1

PROJECT

SITE

LEGEND

BORING

TEST LOCATION

GB-1

GB-2

B-1

B-2

FIGURE 2

PLAN OF BORINGS

FIGURE 5

FAT

CLAY

APPENDIX A

Site Photos

TEST B-1

TEST B-2

APPENDIX B

Information from TrueGrid Pavers

7.0 PROVISIONS

Seabrook Sports Complex-Report File1