10408-07-wld1539- final design analysis - rev 1

Building A63 Parking Lot Contract No. N40085-10-D-9431

Task Order 0007

Naval Station Newport Newport, Rhode Island

Final Design Submittal Package Design Analysis

Revision 1

October 2014

Prepared for:

Naval Facilities Engineering Command Mid-Atlantic

PWD Newport 1 Simonpietri Drive

Newport, RI 02841-1712

Watermark

10408-07 Final Design, Design Analysis – Revision 1 i October 2014 Building A-63 Parking Lot Repairs, Naval Station Newport, Newport, RI WLD1539

TABLE OF CONTENTS

SECTION PAGE 1.0 INTRODUCTION ................................................................................................................................. 1-1 1.1 Project Background ............................................................................................................................. 1-1 1.2 Project Objectives ............................................................................................................................... 1-1 2.0 HAZARDOUS MATERIALS .............................................................................................................. 2-1 2.1 General ................................................................................................................................................ 2-1 2.2 Design Criteria .................................................................................................................................... 2-1 2.3 Site Investigations ............................................................................................................................... 2-1

2.3.1 Previous Hazardous Material Survey Information ..................................................................... 2-1 2.3.2 Recent Hazardous Material Survey Investigations ..................................................................... 2-1

2.4 Summary of Findings .......................................................................................................................... 2-1 2.4.1 Hazardous Materials Abatement ................................................................................................. 2-1

3.0 GEOTECHNICAL ................................................................................................................................ 3-1 3.1 General ................................................................................................................................................ 3-1 3.2 Site and Subsurface Investigations ...................................................................................................... 3-1

3.2.1 Previous Subsurface Information ................................................................................................ 3-1 3.2.2 Recent GZA Explorations ............................................................................................................ 3-1 3.2.3 Subsurface Conditions ................................................................................................................. 3-2 3.2.4 Groundwater ............................................................................................................................... 3-2

3.3 Evaluation and Recommendations ...................................................................................................... 3-2 3.3.1 Pavement ..................................................................................................................................... 3-2

3.4 Construction Considerations ............................................................................................................... 3-3 3.4.1 Pavement Subgrade Preparation ................................................................................................ 3-3 3.4.2 Construction Dewatering ............................................................................................................ 3-3 3.4.3 Excavation Support ..................................................................................................................... 3-4

4.0 CIVIL ..................................................................................................................................................... 4-1 4.1 General ................................................................................................................................................ 4-1 4.2 Existing Conditions ............................................................................................................................. 4-1

4.2.1 Location ....................................................................................................................................... 4-1 4.2.2 Topography ................................................................................................................................. 4-1 4.2.3 Vegetation/Landscaping .............................................................................................................. 4-1 4.2.4 Site Features ................................................................................................................................ 4-1 4.2.5 Vehicular Access and Circulation ............................................................................................... 4-1 4.2.6 Site Utilities ................................................................................................................................. 4-1

4.3 Design Criteria .................................................................................................................................... 4-2 4.4 Site Design .......................................................................................................................................... 4-2

4.4.1 Survey .......................................................................................................................................... 4-2 4.4.2 Layout .......................................................................................................................................... 4-2 4.4.3 Demolition ................................................................................................................................... 4-2 4.4.4 Grading and Paving .................................................................................................................... 4-3 4.4.5 Access and Circulation ................................................................................................................ 4-3

4.5 Utility Design ...................................................................................................................................... 4-3 4.5.1 Water (Potable and Fire Protection) Supply .............................................................................. 4-3 4.5.2 Sanitary Sewerage ....................................................................................................................... 4-3 4.5.3 Stormwater Drainage .................................................................................................................. 4-3 4.5.4 Electrical Distribution ................................................................................................................. 4-5 4.5.5 Natural Gas ................................................................................................................................. 4-5 4.5.6 Site Communication and Security ............................................................................................... 4-5

Watermark

10408-07 Final Design, Design Analysis – Revision 1 ii October 2014 Building A-63 Parking Lot Repairs, Naval Station Newport, Newport, RI WLD1539

4.6 Miscellaneous Features ....................................................................................................................... 4-5 4.7 Permitting ............................................................................................................................................ 4-5 5.0 STRUCTURAL ..................................................................................................................................... 5-1 5.1 General ................................................................................................................................................ 5-1 5.2 Findings ............................................................................................................................................... 5-1 5.3 Recommendations ............................................................................................................................... 5-1 6.0 ENGINEERING CONSIDERATIONS AND INSTRUCTIONS ...................................................... 6-1 6.1 Engineering Considerations ................................................................................................................ 6-1

TABLES

Table 3-1 Recommended Pavement Cross-Sections .......................................................................................... 3-3

APPENDICES

Appendix A Civil Calculations Appendix B Soil Management Plan Appendix C Geotechnical Engineering Report – June 11, 2014; Revised October 9, 2014 Appendix D Retaining Wall Inspection Report Appendix E Storm Water Pollution Prevention Plan Appendix F Storm Water Management System Operation and Maintenance Schedule

Watermark

10408-07 Final Design, Design Analysis – Revision 1 1-1 October 2014 Building A-63 Parking Lot Repairs, Naval Station Newport, Newport, RI WLD1539

1.0 INTRODUCTION

Watermark Environmental, Inc. (Watermark) has prepared this Design Analysis for the Final Design Submittal for the Building A63 Parking Lot project at the Naval Station Newport, Newport, Rhode Island (the Project) under Contract No. N40085-10-D-9431, Task Order 0007 with the Naval Facilities Engineering Command (NAVFAC) Mid-Atlantic. This Design Analysis, along with the Design Drawings and Specifications, are submitted to meet the Final Design Submittal requirements for the Project.

1.1 Project Background

NAVFAC Mid-Atlantic issued a Request for Proposal (RFP) for the Building A63 Parking Lot, Naval Station Newport, Newport, RI 02841 dated May 2011, which included the documents listed below.

Part 1 – Proposal Forms and Documents

Part 2 – General Requirements, including Attachment A Project, Specific General Requirements

Part 3 – Statement of Work / The Project Program

Part 4 – Minimum Materials, Engineering, and Construction Requirements

Part 5 – Project Specific Technical Specifications

Part 6 – Attachments (providing reports, specifications, and drawings)

1.2 Project Objectives

The intent of the Project is to provide a new parking lot pavement structure and surface stormwater drainage system at the parking and access roads around the perimeter of Building A63 using low-impact design (LID) best practices to the extent practical. Building A63 is the base Public Works Department (PWD) Production Shop Facility and is located in the Coddington Cove area of Naval Station Newport. The building serves as the PWD Production Division shops. The parking lot and roadway pavement is in poor condition and stormwater does not properly drain in some locations. The parking lot has two distinct areas: a north parking area and a south parking area that are connected by a service road along the East side of Building A63. The parking lot and access roads are in need of repairs and resurfacing. Drainage improvements are also necessary. The area of improvements is large enough to require that provisions of the Rhode Island (RI) Stormwater Design and Installation Standards Manual be incorporated into the Project.

The Project will be divided into two phases to permit use of a minimum of one half the existing parking areas at a time. Phase 1 will include the north half of the site while Phase 2 will include the south half of the site. This will permit operational access to Building A63 during re-construction of the parking lot and access road surfaces.

All subsurface features will be located and identified, to the maximum extent possible, in coordination with the base Utility Department. Site utility surveys will be completed using Ground Penetrating Radar (GPR) to locate and document underground utilities and obstructions.

The existing bollards will be evaluated for effectiveness and protective pipe bollards will be provided at all overhead doors, entry and exit doors, downspouts, ladders, at-grade utility fixtures, and other locations, as required.

The existing curved concrete retaining wall located on the south side of the building will be evaluated and repaired, or if determined to be beyond repair, replaced.

Existing surfaces are varied and consist of bituminous concrete (asphalt); concrete; packed stone/dirt; and former railroad bedding with timber rail ties, and in some locations, steel rails. These surfaces will be removed, as required, to meet the line and grade of the new pavement structure. All debris not reused for the work will be disposed of off Government property. Soil, loam, and top soil brought on-site will be certified as clean fill prior to delivery and installation in accordance with the Naval Station Newport Soil Management Plan (Dorocz, 2010) (Appendix B).

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2.0 HAZARDOUS MATERIALS

2.1 General

The Building A63 Parking Lot will be constructed in a manner that will reduce the impacts on any existing hazardous materials.

Demolition is required as part of the Project. Items to be demolished are listed below.

Bituminous concrete (pavement)

Portland cement concrete (pavement)

Gravel base (pavement)

Soil fill of unknown composition

Naturally occurring soil

Demolition may require hazardous materials to be removed. Hazardous materials that will need to be disposed of off-site, if encountered, includes soil containing naturally occurring arsenic.

2.2 Design Criteria

All work will be performed in accordance with the standards outlined in the RFP documents. Particular emphasis is placed on the documents listed below that establish minimum requirements.

U.S. Department of Defense (DOD) Unified Facilities Criteria (UFC) 1-200-01, General Building Requirements

UFC 1-300-09N, Project Procedures

UFC 3-800-10N, Environmental Engineering for Facility Construction

Soil Management Plan, Naval Station Newport, Newport, RI (Dorocz, 2010)

Applicable federal, state, and local requirements for disposal of waste materials.

2.3 Site Investigations

2.3.1 Previous Hazardous Material Survey Information

The Soil Management Plan (Appendix B) has been reviewed relative to the work identified for the Project.

2.3.2 Recent Hazardous Material Survey Investigations

In accordance with the Soil Management Plan, the Project area soils contain arsenic concentrations that exceed the state residential, industrial, and commercial direct exposure criteria as defined in the remediation regulations.

Further information on the management of on-site soil is provided in the Soil Management Plan.

2.4 Summary of Findings

2.4.1 Hazardous Materials Abatement

The removal and disposal of soil generated as part of this Project will be conducted per Naval Station Newport regulations and procedures and applicable state and federal regulations. Excess soil generated will be disposed of at a solid waste landfill. The Navy will be notified if any other hazardous materials are encountered.

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3.0 GEOTECHNICAL

3.1 General

The site is located along the northern side of Coddington Highway at the Newport, Rhode Island Naval Station. The Site is occupied by a one-story structure (Building A63) which is generally located in the center of the Site. The majority of the Site to the north, east, and south of Building A63 is paved with bituminous asphalt. In most locations, the asphalt is considerably distressed. Grades in most of the paved areas are generally level at about elevation 24 feet. The Site is accessed via paved driveways in the northeastern and southwestern corners of the Site. Grades at the northeastern driveway slope from about elevation 28 to 24 feet. Grades at the southwestern driveway slope from about elevation 16 to 24 feet. Several concrete pads supporting various pieces of equipment (i.e., tanks, transformers) are located throughout the paved areas. In addition, about 60 feet of railroad tracks are located at the surface to the north of the building.

All work will be performed in accordance with the standards outlined in the RFP documents. Particular emphasis is placed on the documents listed below that establish minimum requirements.

UFC 3-250-01FA, Pavement Design for Roads, Streets, Walks, and Open Storage Areas

UFC 3-250-03, Standard Practice Manual for Flexible Pavements

3.2 Site and Subsurface Investigations

3.2.1 Previous Subsurface Information

Not available.

3.2.2 Recent GZA Explorations

GZA subcontracted New Hampshire Boring of Brockton, Massachusetts to perform seven soil borings (GZ-1 through GZ-7) in proposed pavement replacement areas on May 7, 2014. Borings were performed using a truck-mounted drill rig. Borings GZ-2 and GZ-5 were performed in the general areas of proposed subsurface stormwater discharge areas and carried to depths of 10 feet. The remaining borings were each carried to depths of 6 feet. The borings were backfilled with cuttings and patched at the surface with cold-patch asphalt. Standard Penetration Tests (SPTs) were performed and split spoon samples were obtained continuously in the borings. GZA field representatives observed the soil borings and classified the soil samples using the modified Burmister Classification System. The test pit logs are included with the Geotechnical Engineering Report in Appendix C. Four soil samples obtained from the recent explorations were submitted to GZA’s geotechnical laboratory subcontractor, Thielsch Engineering, for grain size distribution analyses to confirm field classifications and assist in evaluating reuse potential of the soil. Laboratory test results for samples taken from the recent borings are included with the Geotechnical Engineering Report in Appendix C.

Watermark performed additional subsurface explorations to supplement the previous subsurface explorations to further evaluate: 1) subgrade soils at the Site; and, 2) whether a base course fill generated from full depth reclamation of the existing pavement and underlying fill would meet the recommended gradation criteria set forth in UFC 3-250-01FA.

On September 19, 2014, Watermark performed 14 test holes (TH-1 through TH-15, TH-6 was not performed) at proposed pavement locations to supplement the six test borings (GZ-1 through GZ-6) performed during the initial design phase of the project.

The test holes consisted of shallow hand excavations. Prior to excavating, the existing pavement was saw cut and removed. The excavations were carried to depths of 9 to 14 inches below the top of pavement. Watermark representatives performed the excavations, collected soil samples, and logged the explorations. The thickness of the existing pavement ranged from 2 to 4 inches. There was no existing pavement at TH-7 and TH-8. The average pavement thickness (including the areas with no pavement) was 2.4 inches. The information obtained at the test hole locations by Watermark is summarized in Appendix C.

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3.2.3 Subsurface Conditions

The following is a summary of soil and rock conditions encountered in the recent subsurface explorations. Additional details are provided in the Geotechnical Engineering Report in Appendix C.

Asphalt – With the exception of boring GZ-1, bituminous asphalt was encountered at the surface of each boring. The thickness of the asphalt ranged from 1 to 2 inches.

Fill – Based on the borings, there is not a consistent layer of typical pavement base course fill (well-graded, free-draining) throughout the existing paved areas. Soil that would marginally meet the typical criteria for pavement base course fill was encountered in boring GZ-3 at a thickness of 5 inches, boring GZ-5 at a thickness of 13 inches, and boring GZ-6 at a thickness of 12 inches. The fill described above generally consisted of brown fine to coarse sand with up to 35 percent gravel and about 10 to 15 percent silt.

o The remaining fill consists of medium dense to very dense, gray-brown, fine to coarse sand with up to 50 percent silt and up to 35 percent gravel. In borings GZ-1, GZ-2, and GZ-6, the gravel component of some samples was a completely weathered shale-like mineral.

o Overall, fill was encountered to depths of 1 to at least 6 feet. The fill was not fully penetrated in boring GZ-4 which was carried to a depth of 6 feet.

Silty Sand – With the exception of boring GZ-4, natural silty sand was encountered below the fill in each of the borings. The silty sand consists of brown, fine to medium sand with up to 50 percent silt with up to 35 percent gravel (but mostly less than 10 percent).

Soil samples from test holes TH-2, TH-4, TH-10, and TH-12, which were considered to be representative of typical conditions, were submitted to Thielsch Engineering of Cranston, Rhode Island for gradation analyses. Based on the laboratory test results, the volume of soil retained by a No. 200 Sieve by weight ranged from 7.9 to 14.8 percent. Refer to Appendix C for more information.

3.2.4 Groundwater

Groundwater depth was measured in borings GZ-2, GZ-5, and GZ-6 at depths of about 5.5 to 9.5 feet. These depths correspond to elevations ranging from about elevation 14.5 to 18.5 feet. Groundwater was not encountered in borings GZ-1, GZ-3, GZ-4, or GZ-7.

Groundwater was not encountered in test holes TH-1 through TH-15.

3.3 Evaluation and Recommendations

3.3.1 Pavement

The geotechnical design and construction recommendations presented are based on evaluation of the available data. Refer to Appendix C for more information. The nature and extent of variations between subsurface explorations may not become evident until construction. If variations then appear evident, it will be necessary to reevaluate these.

The pavement recommendations presented are based on the criteria set forth in the “Unified Facilities Criteria, Pavement Design for Roads, Streets, Walks, and Open Storage Areas, UFC 3-250-01FA”, dated January 16, 2004.

The paved areas will be accessed primarily by passenger vehicles and light duty vans. However, it is expected that larger trucks will also access the Site to make deliveries to loading dock areas at Building A-63.

These areas correspond to Category III based on the definitions in UFC 3-250-01-01FA as listed below.

a. Category III: traffic containing as much as 15 percent trucks, but with not more than one percent of the total traffic composed of trucks having three or more axles

Watermark


Based on the criteria set forth in UFC 3-250-01FA, the minimum cross-section of pavement and underlying base course is 9 inches for Category III as presented in Table 3-1.

Using the additional subsurface data, GZA has reevaluated the proposed pavement cross section for the Site. GZA utilized the supplemental subsurface explorations to evaluate the subgrade soils and a base course generated by full-depth reclamation of the existing pavement and underlying fill. The pavement cross section was developed using the criteria set forth in the UFC. The supplemental explorations provide more comprehensive coverage across the proposed parking lot than the initial six test borings. After evaluating the existing fill in the upper two feet below the existing pavement the revised pavement cross-section per the UFC is as presented in Table 3-1:

Table 3-1 Recommended Pavement Cross-Sections

Recommended Pavement Cross-Section Per UFC 3-250-01FA

Minimum Thickness

Category III

Finish Course 1.0 inches

Binder Course 2.0 inches

Base Course 9 inches Finish course and binder course will adhere to one of the three gradation requirements set forth in UFC 3-250-03, Standard Practice Manual for Flexible Pavements, Table 2-1.

Watermark proposes to perform full-depth reclamation of the existing pavement into the underlying soils to provide a pavement base course. Assuming 2.4 inches of existing pavement is blended with 6.6 inches underlying fill, we estimate the gradation of the top 9 inches of fill (proposed base course) will be approximately:

Gravel – 43%

Sand – 46%

Fines – 11%

This estimate assumes that the reclaimed pavement will be pulverized to 70 percent gravel, 25 percent sand, and 5 percent silt. Based on a projected gradation curve for the blended base course fill, we anticipate that the blended base course will meet this criterion. Refer to Appendix C for more information.

3.4 Construction Considerations

3.4.1 Pavement Subgrade Preparation

Reclaim the existing asphalt and blend the pulverized material into the underlying fill. Existing fill below the bottom of the blended base course will be left in place and proof-compacted with a minimum of six passes of a vibratory drum roller (with a minimum static drum weight of 10,000-pounds capable of at least 20,000 pounds of dynamic force). Any weak or soft spots identified during proof-compacting will be excavated and replaced with compacted base course fill.

The blended base course fill will be placed in lifts no greater than 12-inches-thick and compacted with at least six passes of a ride-on vibratory roller. The recommended minimum compaction is 95 percent based on percentage of maximum dry density as defined by ASTM D-1557 Method C.

Frozen soil will not be placed as fill. In addition, fill will not be placed over frozen soil.

3.4.2 Construction Dewatering

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Based on the recently performed subsurface explorations, groundwater is not expected to be encountered during subgrade preparation. However, water that collects from precipitation events may impact construction. Temporary control measures will be implemented to reduce the amount of surface water (from rainfall run-off) from potentially entering and ponding in the excavations. Temporary measures will include, but not be limited to, construction of drainage ditches to divert and/or reduce the amount of surface water flowing over exposed subgrades during construction. Discharge of pumped water off-site (if required) will be performed in accordance with all federal, state, and/or local regulations.

3.4.3 Excavation Support

Excavation will be performed in accordance with all applicable local, state, and federal safety regulations, including the current Occupational Safety and Health Administration (OSHA) Excavation and Trench Safety Standards.

Slope height, slope inclination, or excavation depths (including utility trench excavations) will in no case exceed those specified in local, state, or federal safety regulations (e.g., OSHA Health and Safety Standards for Excavations, 29 CFR Part 1926, or successor regulations). Such regulations will be strictly enforced.

As a safety measure, all vehicles and soil piles will be kept a minimum lateral distance from the crest of the slope equal to no less than the slope height. Exposed slope faces will be protected against the elements.

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4.0 CIVIL

4.1 General

Civil work will include demolition of existing pavement; regrading of the site; installation of a stormwater management system; and other miscellaneous improvements to support the effort. Portions of the site will be developed and constructed to be compliant with the Architectural Barriers Act (ABA).

4.2 Existing Conditions

4.2.1 Location

The Project will be constructed on an approximately 4.0 acre site located adjacent to Building A63. The project is bounded by Building 47 to the west; Coddington Highway to the south; open space and outdoor storage to the north; and a parking lot to the east. Coddington Highway is separated from Naval Station Newport by a security fence to the South.

4.2.2 Topography

WSP conducted a field survey of the site in April 2014 which references the Rhode Island State Plane Coordinate System, North American Datum of 1983 (NAD83) (1986 Adjustment), and North American Vertical Datum (NAVD) of 1988. Elevations are reported in feet. Existing topography slopes downward from east to west at a rate of approximately 2.2 percent. Site elevations vary from approximately Elevation 25 to Elevation 17 across the project. Once off the site, the topography continues at approximately 2.2 percent into the adjacent parcel.

4.2.3 Vegetation/Landscaping

Portions of the project are vegetated with grass and trees. The area along the southern boundary of the project is vegetated with grass and trees, an isolated island to the north consists only of grass, a steely sloped thin strip of grassed area exists along the eastern project boundary, and a steeply sloped grassed area exists along the western boundary.

4.2.4 Site Features

The Project site is mostly paved without curbing. Building A63 is a block and bar joist high-bay structure with a recent single story addition along the East side. Roof run-off is collected via rain leaders and downspouts which are directed into the existing adjacent stormwater system.

4.2.5 Vehicular Access and Circulation

Site access is provided from the west through Building 47 parking lot, the adjacent parking lot to the east, and from the north through the outdoor storage area.

4.2.6 Site Utilities

Water – A water main loop serves fire hydrants along the north and south sides of the project. The same loop provides a water service connection to Building A63 at various locations. A water main runs parallel to the security fence and Coddington Highway. The same main provides a water service across the south parking area to Building A63.

Sewer – An 8-inch sanitary sewer service serving the north side of Building A63 runs north into several sewer manholes and off-site. There is no sewer on the south side of the project.

Storm Drain – Storm drainage outfall within the base is directed to the Atlantic Ocean located west of the project using a closed system. The project storm drain system collects run-off from around Building A63 that empties into an adjacent closed system.

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Gas – A natural gas main runs along the security fence to the South within the grassed area.

Electric – An underground electric service crosses the south parking area and runs from pole 282 located at the security fence to a transformer adjacent to Building A63. From the transformer, the service continues in a northerly direction to the south side of Building A63.

Communications/Security – Fiber optics and television lines are located to the west of Building A63 and are orientated in a north south direction.

4.3 Design Criteria

The design will be prepared in accordance with the standards outlined in the RFP documents. The design will also satisfy State of Rhode Island criteria, as applicable to a federal installation. Particular emphasis is placed on the documents listed below that establish minimum requirements.

U.S. DOD UFC

- UFC 3-200-10N, Civil Engineering

- UFC 3-201-02, Landscape

- UFC 3-210-10, Low Impact Development

- UFC 4-010-01, DOD Minimum Antiterrorism Standards for Buildings

ABA Accessibility Guidelines for Buildings and Facilities (ABAAG)

Rhode Island Stormwater Design and Installation Standards Manual, Rhode Island Department of Management and Coastal Resources Management Council, December 2010

Rhode Island Division of Environmental Management (RIDEM), Soil Erosion and Sediment Control guidance

Rhode Island Department of Transportation Standard Specifications for Road and Bridge Construction, 2004 Edition

Environmental Protection Agency (EPA) – National Pollution Discharge Elimination System (NPDES)

Rhode Island Pollution Discharge Elimination System (RIPDES)

“Custom Soil Resource Report for State of Rhode Island: Bristol, Kent, Newport, Providence, and Washington Counties” (Soils Report) dated January 14, 2014

4.4 Site Design

4.4.1 Survey

The existing conditions survey performed by WSP in April 2014 was used as the basis for the site design. Underground utilities as depicted on the plan were delineated by Richard Barracco of BL Companies in accordance with the American Society of Civil Engineers (ASCE) specification for a Quality Level B (QLB) site investigation and field located by WSP. Refer to Design Drawings C-101 and C-102 for additional information.

4.4.2 Layout

The new bituminous concrete pavement will occupy a footprint similar to the existing bituminous concrete pavement. An increase in bituminous concrete is not being proposed. Refer to Design Drawings C-111 and C-112 for additional information.

4.4.3 Demolition

Perform full-depth pavement reclamation of the existing pavement into the underlying fill in order to provide a pavement base course that will meet the recommended gradation criteria as defined in Appendix C – Geotechnical Engineering Report. Demolition debris not reused as part of this project will be segregated and

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documented prior to removal from the site to be disposed of in a legal regulated manner. Refer to Design Drawings C-103 and C-104 for additional information.

4.4.4 Grading and Paving

The primary objective of the site grading is to maintain the existing grades to the extent practical while minimizing impacts to the remainder of the site. As a result, minor grade changes are being proposed. Grading associated with the handicap parking and accessible route will be incompliance with ABAAG. The pavement design will provide for a 20 year life expectancy.

4.4.5 Access and Circulation

Access to the site will remain unchanged. There are 64 Privately Owned Vehicle (POV) and 7 Government Owned Vehicle (GOV) parking stalls proposed in the northern portion of the Project and 45 GOV parking stalls proposed in the southern portion of the Project. Unless otherwise indicated, provisions for two-way traffic will be provided except the north parking area will provide for handicap parking as well as an accessible route to the main entrance to Building A63. Refer to Design Drawings C-105 and C-106 for additional information.

4.5 Utility Design

All utility connections will be coordinated directly through Naval Station Newport prior to the start of any work. Refer to the Design Drawings for additional information.

4.5.1 Water (Potable and Fire Protection) Supply

Water service into Building A63 will not be altered or interrupted due to this project.

4.5.2 Sanitary Sewerage

Sanitary sewer service into Building A63 will not be altered or interrupted due to this project.

4.5.3 Stormwater Drainage

The new parking lot will drain to the existing catch basins and closed drainage system. New manholes will direct the stormwater to retention galleries constructed beneath the new parking lot. The retention galleries will provide stormwater cleaning and recharging to groundwater via infiltration. In accordance with the RFP, the new parking lot stormwater design will be regulated by RIDEM and, thus, the stormwater design will meet the requirements of the RIDEM “Rhode Island Storm Water Design and Installation Standards Manual” dated December 2010.

In accordance with RIDEM, the Project is defined as a redevelopment site with more than 40% impervious coverage and, therefore, Standards 2, 3, and 7-11 will be addressed to the extent practical. Recharge and stormwater quality will be managed by providing on-site structural best management practices (BMPs) to provide recharge and water quality management for at least 50% of redeveloped area.

The Project site has been divided into nine subcatchments for the Pre-Developed (Pre) analysis and Post-Developed (Post) analysis. For the purpose of this analysis, the Pre site analysis contains subcatchments one through nine (C1 through C9) and the Post site analysis contains subcatchments 10 through 90 (C10 through C90). The subcatchment limits and groundcover determinations have been determined based on the results of the existing conditions survey.

HydroCAD, which is based upon the Soil Conservation Service’s (1986) revised Technical Release 55 (TR-55), was used for the determination of run-off volumes, peak discharge rates, and storage requirements. The HydroCAD reports for the Pre and Post conditions are located in Appendix A.

The Project site has been analyzed using HydroCAD and by determining Design Points (DPs) such that the Pre and Post conditions can be compared at the same point. The DPs assigned to this analysis are Design Point “A” (DPA), Design Point “B” (DPB), and Design Point “C” (DPC). DPA is associated with C1 and C10 which drain

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through a 12-inch clay pipe; DPB is associated with C2 through C8 and C20 through C80 which drain through a 24-inch reinforced concrete pipe (RCP); and DPC is associated with C9 and C90 which drain through a 10-inch RCP. Refer to Drawings C-901 through C-904 and the Pre and Post subcatchment worksheets in Appendix A for more information.

Due to the depth of the existing drainage system and the need to match the existing grading arrangement in order to maintain the hydrology of each subcatchment, it is not practical to provide a Low Impact Development (LID) Qualifying Pervious Area (QPA) for this project. However, an overall reduction in impervious area has been accomplished. Under Pre conditions, there are 98,125 square feet of impervious area and under Post conditions there are 95,240 square feet of impervious area for an overall reduction of 2,885 square feet of impervious area.

The applicable RIDEM Standards are listed below.

Standard 2 – Groundwater: Stormwater will be recharged within the same subcatchment to maintain base flow at the pre-development recharge levels to the maximum extent practicable. In accordance with this standard, the recharge will be accomplished within 72 hours and the bottom of the infiltration gallery will be located a minimum of two (2) feet above the groundwater elevation. The stormwater recharge requirement (Rev) is based on the Post impervious area. The Rev will be calculated based on the impervious area within each Post subcatchment. The Hydrologic Soil Group (HSG) of C for calculating Rev has been determined based on a report entitled “Custom Soil Resource Report for State of Rhode Island: Bristol, Kent, Newport, Providence, and Washington Counties” (Soils Report) dated January 14, 2014 and included with the calculations in Appendix A. The resultant Rev has been determined to be 203 cubic feet for C10 and 789 cubic feet for C20 through C80. C90 does not require Rev due to a lack of impervious area. As can be seen in the Post HydroCAD report, the 1” rainfall event for C10 produces 0.035 acre-feet (1,525 cubic feet) of run-off and for C20 through C80 produces 0.133 acre-feet (5,793 cubic feet) of run-off. For C10, a portion of the 1,525 cubic feet of run-off will be diverted into Retention Gallery 1 (RG1) for infiltration. For C20 through C80, a portion of the 5,793 cubic feet of run-off will be diverted into Retention Gallery 2 for infiltration. In the event RG1 or RG2 reaches their limit, an overflow device will direct the excess stormwater to the existing drainage system where it will continue to move off-site. Refer to the drawings (submitted under separate cover) and Appendix A for more information. Refer to Standard 3 below for compliance determination.

Standard 3 – Water Quality: The Water Quality Volume (WQV) will be treated before discharge. In accordance with this standard, an appropriately sized Water Quality Inlet (WQI) has been selected to meet this standard. The WQV is based on the Post impervious area. For C10, the WQV has been determined to be 811 cubic feet and for C20 through C80 the WQV has been determined to be 3,157 cubic feet. Both of these values represent a 50% reduction in run-off in order to demonstrate capture and treatment of 50% of the Post impervious area. C90 does not require WQV due to a lack of impervious area. As stated above, the 1” rainfall event for C10 produces 0.035 acre-feet (1,525 cubic feet) of run-off and for C20 through C80 produces 0.133 acre-feet (5,793 cubic feet) of run-off. For C10, the 811 cubic feet portion of the 1,525 cubic feet of run-off will be diverted into Water Quality Inlet 1 (WQI 1) for treatment then conveyance into RG1 for infiltration. For C20 through C80, the 3,157 cubic feet portion of the 5,793 cubic feet of run-off will be diverted into WQI 2 for treatment then conveyance into RG2 for infiltration. Standard 3 stipulates that Rev is contained within WQV. The resultant Rev and WQV volumes are then 811 cubic feet for C10 and 3,157 cubic feet for C20 through C80. RG1 has been sized to store and infiltrate 0.019 acre-feet (827 cubic feet) and RG2 has been sized to store and infiltrate 0.078 acre-feet (3,398 cubic feet). Given these results, Standards 2 and 3 have been met. Refer to Appendix A for more information.

Standard 7 – Pollution Prevention: A recommended Storm Water Pollution Prevention Plan (SWPPP) is included in Appendix E. All development sites require the use of source control and pollution prevention measures to minimize the impact that the land use may have on storm water runoff quality. These measures have been outlined in the SWPPP. The report describes pollution prevention

Watermark


techniques that will be implemented to the extent practical in order to prevent pollutants from coming into contact with storm water runoff.

Standard 8 – Land Use with Higher Potential Pollutant Loads: This standard is not applicable to this Project.

Standard 9 – Illicit Discharges: This standard is not applicable to this Project.

Standard 10 – Construction Erosion and Sedimentation Control: Refer to Drawings C-113 and C-114 for the recommended Erosion and Sedimentation Control practices. A Stormwater Pollution Control Plan (SWPCP) will be developed as per the EPA and RIPDES requirements and will be submitted to Naval Station Newport for permitting efforts prior to construction activities.

Standard 11 – Stormwater Management System Operation and Maintenance: A recommended Stormwater Management System Operation and Maintenance schedule is included in Appendix F.

4.5.4 Electrical Distribution

The electrical service into Building A63 will not be altered or interrupted due to this project.

4.5.5 Natural Gas

The natural gas service into Building A63 will not be altered or interrupted due to this project.

4.5.6 Site Communication and Security

The communications and security services into Building A63 will not be altered or interrupted due to this project.

4.6 Miscellaneous Features

Additional site features include the repair and/or the replacement of a double leaf gate and chain link fencing at the southwest entrance to the Project. The location of an area for the parking of a tractor trailer has been provided and the pavement in this area will be of a heavy duty pavement section for durability. Bollards have been included to protect the at grade air conditioning unit along the south wall of Building 13 and wheel stops have been provided in parking stalls to protect Building 13 from vehicle strikes.

4.7 Permitting

Below is a summary of the permits identified as being required for the Project.

Water Pollution, Stormwater Management Discharge Permit, General NPDES (> 1 acre disturbance) – Construction activities will disturb more than one acre. A National Pollutant Discharge Elimination System (NPDES) General Permit is required for the Discharge of Stormwater and Dewatering Wastewaters from Construction Activities from the RIDEM as Rhode Island is a NPDES delegated state with general permitting authority. A SWPCP will be developed as per the EPA and RIPDES requirements.

Water Quality Certification – Coverage under RIPDES Stormwater Discharge Permit.

Other Permits, Digging Permit – A permit is required for all excavation work. The permit is issued by Naval Station Newport.

Consistent with the requirements in the NAVFAC Project Program requirements, Watermark will not take action to apply for and obtain any of the permits listed above.

Watermark


5.0 STRUCTURAL

5.1 General

The concrete retaining wall was inspected on May 20, 2014 by Dankers Structural Consulting, LLC. The purpose of the investigation was to assess the structural condition of the existing retaining wall in the parking lot of Building A63. The wall inspection was a visual inspection of the wall without exploratory demolition. The wall is a curved concrete retaining wall that varies in height. Adjacent to Building A63 the wall retains approximately four feet of soil and tappers down to flush with grade along a distance of approximately 96 feet. The top of the wall extend approximately 12 inches above the high side grade along the length of the wall.

5.2 Findings

The top of the wall extending above the high side grade is cracked and spauling exposes the steel reinforcement. The face of the wall has horizontal cracks along the length of the wall. The wall face cracks have deposits of white efflorescent material presumably created from water seeping through the wall cracks. Along the curve of the wall, a vertical reinforcing bar is exposed due to zero concrete cover. This appears to have occurred during construction. Along the face of the wall, the concrete is bulging and sounding the concrete reveals that the surface is delaminating.

5.3 Recommendations

The wall is vertically plumb and retains soil but is deteriorating. In general, the top of the wall and vertical surface are in poor condition.

The loose concrete along the top wall curb and vertical surface will be removed and replaced. Large cracks will be routed out and repaired with an injected repair adhesive suitable for exterior conditions. The back of the wall will be exposed and waterproofed. The weep holes will be cleaned out and backed with a bed of crushed stone wrapped in geotechnical cloth.

Watermark


6.0 ENGINEERING CONSIDERATIONS AND INSTRUCTIONS

Engineering considerations and instructions pertaining to the work are outlined below.

6.1 Engineering Considerations

The engineering considerations listed below were considered during the design process.

Understanding of the client needs and contract requirements.

Review of applicable code requirements.

Establish locations for proposed features and equipment.

Phasing of the Project to permit use of a minimum of one half the existing parking area at a time. The Project will be divided into two phases to permit use of one half the existing parking. Phase 1 will include the north half of the site while Phase 2 will include the south half of the site. This will permit operational access to Building A63 during re-construction of the parking lot and access road surfaces.

Watermark

APPENDIX A

Civil Calculations

2"CHERRY

DMHRIM= 16.25

INV.1=12.25INV.2=12.25DEPTH=12.25

SMHRIM= 25.10

INV.1=22.48INV.2=22.48DEPTH=22.48SMH

RIM= 24.80

INV.1=21.73INV.2=22.63INV.3=21.73DEPTH=21.73

SMHRIM= 24.50

INV.1=20.08INV.2=20.03INV.3=20.50DEPTH=20.03

SMHRIM= 24.78

INV.1=12.88INV.2=18.28INV.3=12.98INV.4=15.18INV.5=16.08

CB-3RIM= 24.24

DEPTH=16.39

INV.1=18.44INV.2=20.39

CB-2RIM= 24.80

DEPTH=18.46

INV.1=21.01INV.2=20.81

CBRIM= 28.31

DEPTH=25.01

INV.1=25.01

CB RIM= 29.11

DEPTH=26.16

INV.1=NPVFULL OF DEBRIS

CBRIM= 24.40

DEPTH=23.10


CB-1RIM= 23.57

DEPTH=14.57

INV.1=14.67INV.2=18.92

CBRIM= 13.26

DEPTH=8.86

INV.1=10.91

CBRIM= 13.41

DEPTH=10.11

INV.1=10.11INV.2=10.11

CBRIM= 13.36

DEPTH=9.36

INV.1=9.86INV.2=9.66INV.3=11.01

TBM BEL=31.07'FLAT NAILSET IN UP

TBM CEL=16.40'FLAT NAILSET IN UP

1

21

2

3

1

1

2

1

1

2

21

UP NO #

UP NO #

UP #110

UP NO #

UP #286

FDC

FFE=25.23'

FFE=25.24'

FFE=28.09'

FFE=25.35'

FFE=25.13'

FFE=25.05'

FF

12"RCP

15"RCP

8"RCP8"RCP

12"RCP

6"PVC

12"HDPE

8"CLAY

12"CLAY1

2

15"CLAY

30"PVC

1

2

3

5 4

30"CLAY

6"PVC

8"CLAY

6"PVC

1

2 3

8"CLAY

12

3

6"PVC

8"PVC

8"PVC

12

8"PVC

16

1718

19

20

21

22

23

24

24

24

24

24 26

27

28

26 27

25

15

16 17 18 19 20

21

22

23

24

25

26

27

28

24

24

2322

212019

17

18

CC

CC

LOADING DOCK

EOP

STEPS

STEPS

EOP

EOP

BIT.PARKING

BIT.PARKING

GRAVEL/

BROKEN PAVEMENT

EOCRR TRACKS

VGCCONC. PLANTER

WRW

EOP

CONC.PAD

EOP

CRWCONC.PAD

COMM.PIT

COMM.PIT

GARAGE

BUILDING A63

EOG

SYLSTL

UP NO #

FFE=25.25' VIF

DESIGN POINT "A"

RE

PLA

CE

PA

RK

ING

LO

TB

UIL

DIN

G A

-63

NA

VA

L FA

CIL

ITIE

S E

NG

INE

ER

ING

CO

MM

AN

D

PLANNORTH

C-901

NOTES:1. EXISTING CONDITIONS SHOWN HEREON FROM AN ON THE GROUND

SURVEY CONDUCTED BY WSP ON APRIL 10, 2014.

2. THE HORIZONTAL DATUM IS RHODE ISLAND STATE PLANE NAD 83 AND THEVERTICAL DATUM IS NAVD 88.

www.wspgroup.com155 Main Dunstable Rd. Suites 120 & 125 Nashua, NH 03060 603.595.7900

LEGEND:

SUBCATCHMENT NUMBER

SUBCATCHMENT LIMITS

5"CE

DAR

20"O

AK

18"O

AK

20"O

AK

36"B

EECH

11"C

EDAR 16

"OAK

10"O

AK

2"CHERRY

20"O

AK

18"O

AK

15"O

AK

DMHRIM= 16.68

INV.1=10.28INV.2=10.28INV.3=10.38DEPTH=10.28

DMHRIM= 28.16

INV.1=21.46INV.2=21.66INV.3=ABANDONED

DEPTH=21.46

DMHRIM= 29.16

INV.1=CNOINV.2=21.86INV.3=21.76DEPTH=21.36

DMHRIM= 16.17

INV.1=9.37INV.2=10.27INV.3=9.37

DMHRIM= 15.80

INV.1=8.35INV.2=8.35INV.3=8.35

SMHRIM= 25.10

INV.1=22.48INV.2=22.48DEPTH=22.48SMH

RIM= 24.80

INV.1=21.73INV.2=22.63INV.3=21.73DEPTH=21.73

CBRIM= 29.08

DEPTH=19.08

INV.1=24.58INV.2=22.28INV.3=24.58INV.4=22.08

INV

CBRIM= 13.36

DEPTH=9.36

INV.1=9.86INV.2=9.66INV.3=11.01

CB-11RIM= 14.62

DEPTH=8.52

INV.1=10.17INV.2=10.07

CB-10RIM= 15.60

DEPTH=9.45

INV.1=9.50INV.2=9.45

CB-9RIM= 16.21

DEPTH=8.76

INV.1=9.21INV.2=12.51

CB-8RIM= 18.62

DEPTH=8.72

INV.1=9.17INV.2=11.92INV.3=14.02

CB-7RIM= 18.38

DEPTH=9.38INV.1=13.53INV.2=14.71

CB-6RIM= 22.66

DEPTH=14.96

INV.1=15.06INV.2=17.16

CB-5RIM= 23.57

DEPTH=16.57

INV.1=17.07INV.2=17.17INV.3=17.17

CB-4RIM= 24.05

DEPTH=15.55

INV.1=17.35INV.2=17.45INV.3=NPV

TBM AEL=31.82'CHISELED SQUARE

ON CONC. BASE

TBM DEL=21.51'FLAT NAILSET IN UP

CBRIM= 13.36

DEPTH=10.91

INV.1=11.31INV.2=11.11INV.3=11.41

2

3

1

1

2

3

12

12

1

2

1

2

3

2

1

21

41

2

3

1

2

1

2

3

UP NO #

UP NO #

UP #284

UP #83

UP #282

UP #281

FDC

FDCFDC

FDC

FFE=25.23'

FFE=25.24'

FFE=25.05'

FFE=25.15'

FFE=25.28'

FFE=25.18'

FFE=25.12'

FFE=25.22'FFE=25.20'

FFE=25.26'

FFE=25.23'

FFE=25.12'

8"RCP

6"CLAY

8"RCP

6"CLAY10"RCP

10"RCP

10"RCP

10"CI

12"RCP

RCP

18"RCP12"RCP

12"RCP

12"RCP

15"RCP

4"PVC18"HDPE

18"HDPE4"PVC

12

3

18"CLA

Y

1

2

3

24"CLAY

1 2

3

33"RCP

33"RCP33"RCP

33"RCP

4"PVC

36"HDPE

12

3

36"HDPE1

2

31

8"PVC

2526

2728

30

24

24

23

2221

20

18

17

16

15

28

2726

2422

21

19 20

17

CC

CC

BC

EOC

CONC.

PAD

CONC.

PAD

PROPANETANK

EOC

CONC. PAD

W/ TRANSFORMER

CRWCRW

EOP

WOOD DECK

STEPS

STEPS

BROKEN PAVEMENTGRAVEL

BIT.PARKING

VGC

VGC

EOP

CC

CONC. PLANTER

COMM.PIT

CONC.

PADSTEPS

CRW

CRW

BUILDING A63

CODDINGTON WAY

EOG

SYLSTL

24"

29

3

DESIGN POINT "C"

DESIGN POINT "B"

RE

PLA

CE

PA

RK

ING

LO

TB

UIL

DIN

G A

-63

NA

VA

L FA

CIL

ITIE

S E

NG

INE

ER

ING

CO

MM

AN

D

PLANNORTH

C-902


NOTES:1. EXISTING CONDITIONS SHOWN HEREON FROM AN ON THE

GROUND SURVEY CONDUCTED BY WSP ON APRIL 10, 2014.

2. THE HORIZONTAL DATUM IS RHODE ISLAND STATE PLANENAD 83 AND THE VERTICAL DATUM IS NAVD 88.

LEGEND:

SUBCATCHMENT NUMBER

SUBCATCHMENT LIMITS

Total Area 122954 Sq. Feet 2.82 Acres

Pre‐Development

Subcatchments Sq. Feet Acres

C1 20273.00 0.465 Sq. Feet Acres

TO DESIGN POINT "A" Pave 18754.00 0.431 Impervious Area (I) 19463.00 0.447

Roof 709.00 0.016 % Impervious 96 %

Grass 810.00 0.019

Gravel 0.00 0.000

20273.00

C2 20819.00 0.478

Pave 12618.00 0.290 Impervious Area (I) 19464.00 0.447

Roof 6846.00 0.157 % Impervious 93 %

Grass 1355.00 0.031

20819.00

C3 23718.00 0.544


Roof 15239.00 0.350 % Impervious 91 %

Grass 2057.00 0.047

23718.00

C4 7836.00 0.180


Roof 4320.00 0.099 % Impervious 80 %

Grass 1569.00 0.036

7836.00

C5 3609.00 0.083



Grass 0.00 0.000

3609.00

C6 7579.00 0.174



Grass 1689.00 0.039

7579.00

C7 2549.00 0.059



Grass 0.00 0.000

2549.00

C8 19335.00 0.444

TO DESIGN POINT "B" Pave 19222.00 0.441 Impervious Area (I) 19222.00 0.441


Grass 0.00 0.000

Gravel 113.00 0.003

19335.00

C9 17235.00 0.396

TO DESIGN POINT "C" Pave 0.00 0.000 Impervious Area (I) 0.00 0.000

Roof 0.00 0.000 % Impervious %

Grass 16526.00 0.379

Gravel 709.00 0.016

17235.00

Total 122953.00 2.823 Impervious Area (I) 98125.00 2.253

% Impervious 80 %

C1

Subcatchment 1

C2

Subcatchment 2

C3

Subcatchment 3

C4

Subcatchment 4C5

Subcatchment 5

C6

Subcatchment 6

C7

Subcatchment 7

C8

Subcatchment 8

C9

Subcatchment 9

CB1CB

CB-1

CB2CB

CB-2

CB3CB

CB-3

CB4CB

CB-4

CB5CB

CB-5

CB6CB

CB-6

CB7CB

CB-7

CB8CB

CB-8

CB9CB

CB-9

Drainage Diagram for 10408-07 BA63 Pre-DevelopedPrepared by Microsoft, Printed 5/7/2014

HydroCAD® 9.10 s/n 02940 © 2010 HydroCAD Software Solutions LLC

Subcat Reach Pond Link

10408-07 BA63 Pre-Developed10408-07 BA63 Pre-Developed

Printed 5/7/2014Prepared by MicrosoftPage 2HydroCAD® 9.10 s/n 02940 © 2010 HydroCAD Software Solutions LLC

Area Listing (all nodes)

Area(acres)

CN Description(subcatchment-numbers)

0.551 79 50-75% Grass cover, Fair, HSG C (C1, C2, C3, C4, C6, C9)0.019 89 Gravel roads, HSG C (C8, C9)1.630 98 Paved parking, HSG C (C1, C2, C3, C4, C5, C6, C7, C8)0.622 98 Unconnected roofs, HSG C (C1, C2, C3, C4)

2.823 TOTAL AREA



Soil Listing (all nodes)

Area(acres)

SoilGroup

SubcatchmentNumbers

0.000 HSG A0.000 HSG B

2.823 HSG C C1, C2, C3, C4, C5, C6, C7, C8, C90.000 HSG D0.000 Other2.823 TOTAL AREA



Pipe Listing (all nodes)

Line# NodeNumber

In-Invert(feet)

Out-Invert(feet)

Length(feet)

Slope(ft/ft)

n Diam/Width(inches)

Height(inches)

Fill(inches)

1 CB1 14.67 12.25 68.0 0.0356 0.011 12.0 0.0 0.02 CB2 20.81 20.39 84.0 0.0050 0.011 12.0 0.0 0.03 CB3 18.44 17.45 195.0 0.0051 0.011 15.0 0.0 0.04 CB4 17.35 17.17 140.0 0.0013 0.011 12.0 0.0 0.05 CB5 17.07 16.85 44.0 0.0050 0.011 12.0 0.0 0.06 CB6 15.06 14.02 104.0 0.0100 0.011 18.0 0.0 0.07 CB7 13.53 11.92 35.0 0.0460 0.011 12.0 0.0 0.08 CB8 9.17 8.35 70.0 0.0117 0.011 24.0 0.0 0.09 CB9 9.21 9.11 20.0 0.0050 0.011 10.0 0.0 0.0

10408-07 BA63 Pre-DevelopedType III 24-hr 1 inch Rainfall=1.20"10408-07 BA63 Pre-Developed


Time span=0.00-24.00 hrs, dt=0.05 hrs, 481 pointsRunoff by SCS TR-20 method, UH=SCS

Reach routing by Dyn-Stor-Ind method - Pond routing by Dyn-Stor-Ind method

Runoff Area=20,273 sf 96.00% Impervious Runoff Depth>0.89"Subcatchment C1: Subcatchment 1 Flow Length=180' Slope=0.0117 '/' Tc=6.0 min CN=97 Runoff=0.46 cfs 0.035 af







Runoff Area=19,335 sf 99.42% Impervious Runoff Depth>0.98"Subcatchment C8: Subcatchment 8 Flow Length=205' Tc=6.0 min CN=98 Runoff=0.47 cfs 0.036 af


Peak Elev=15.01' Inflow=0.46 cfs 0.035 afPond CB1: CB-112.0" Round Culvert n=0.011 L=68.0' S=0.0356 '/' Outflow=0.46 cfs 0.035 af











Total Runoff Area = 2.823 ac Runoff Volume = 0.179 af Average Runoff Depth = 0.76"20.19% Pervious = 0.570 ac 79.81% Impervious = 2.253 ac



Summary for Subcatchment C1: Subcatchment 1

Runoff = 0.46 cfs @ 12.09 hrs, Volume= 0.035 af, Depth> 0.89"

Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrsType III 24-hr 1 inch Rainfall=1.20"

Area (sf) CN Description18,754 98 Paved parking, HSG C

709 98 Unconnected roofs, HSG C810 79 50-75% Grass cover, Fair, HSG C

0 89 Gravel roads, HSG C20,273 97 Weighted Average

810 4.00% Pervious Area19,463 96.00% Impervious Area

709 3.64% Unconnected

Tc Length Slope Velocity Capacity Description(min) (feet) (ft/ft) (ft/sec) (cfs)

0.8 50 0.0117 0.98 Sheet Flow, First 50Smooth surfaces n= 0.011 P2= 3.30"

1.0 130 0.0117 2.20 Shallow Concentrated Flow, PavedPaved Kv= 20.3 fps

1.8 180 Total, Increased to minimum Tc = 6.0 min

Subcatchment C1: Subcatchment 1

Runoff

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

0.520.5

0.480.460.440.42

0.40.380.360.340.32

0.30.280.260.240.22

0.20.180.160.140.12

0.10.080.060.040.02

0

Type III 24-hr 1 inchRainfall=1.20"Runoff Area=20,273 sfRunoff Volume=0.035 afRunoff Depth>0.89"Flow Length=180'Slope=0.0117 '/'Tc=6.0 minCN=97

0.46 cfs







6,846 98 Unconnected roofs, HSG C1,355 79 50-75% Grass cover, Fair, HSG C


1,355 6.51% Pervious Area19,464 93.49% Impervious Area

6,846 35.17% Unconnected






Runoff

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

0.5

0.45

0.4

0.35

0.3

0.25

0.2

0.15

0.1

0.05

0


0.48 cfs









2,057 8.67% Pervious Area21,661 91.33% Impervious Area15,239 70.35% Unconnected






Runoff

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

0.55

0.5

0.45

0.4

0.35

0.3

0.25

0.2

0.15

0.1

0.05

0


0.50 cfs






Area (sf) CN Description1,947 98 Paved parking, HSG C4,320 98 Unconnected roofs, HSG C1,569 79 50-75% Grass cover, Fair, HSG C

0 89 Gravel roads, HSG C7,836 94 Weighted Average1,569 20.02% Pervious Area6,267 79.98% Impervious Area4,320 68.93% Unconnected






Runoff

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

0.15

0.14

0.13

0.12

0.11

0.1

0.09

0.08

0.07

0.06

0.05

0.04

0.03

0.02

0.01

0


0.14 cfs







0 98 Unconnected roofs, HSG C0 79 50-75% Grass cover, Fair, HSG C0 89 Gravel roads, HSG C

3,609 98 Weighted Average3,609 100.00% Impervious Area






Runoff

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

0.095

0.09

0.085

0.08

0.075

0.07

0.065

0.06

0.055

0.05

0.045

0.04

0.035

0.03

0.025

0.02

0.015

0.01

0.005

0


0.09 cfs







0 98 Unconnected roofs, HSG C1,689 79 50-75% Grass cover, Fair, HSG C

0 89 Gravel roads, HSG C7,579 94 Weighted Average1,689 22.29% Pervious Area5,890 77.71% Impervious Area






Runoff

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

0.15

0.14

0.13

0.12

0.11

0.1

0.09

0.08

0.07

0.06

0.05

0.04

0.03

0.02

0.01

0


0.13 cfs













Runoff

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

0.07

0.065

0.06

0.055

0.05

0.045

0.04

0.035

0.03

0.025

0.02

0.015

0.01

0.005

0


0.06 cfs















Runoff

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

0.5

0.45

0.4

0.35

0.3

0.25

0.2

0.15

0.1

0.05

0

Type III 24-hr 1 inchRainfall=1.20"Runoff Area=19,335 sfRunoff Volume=0.036 afRunoff Depth>0.98"Flow Length=205'Tc=6.0 minCN=98

0.47 cfs






Area (sf) CN Description0 98 Paved parking, HSG C0 98 Unconnected roofs, HSG C

16,526 79 50-75% Grass cover, Fair, HSG C709 89 Gravel roads, HSG C

17,235 79 Weighted Average17,235 100.00% Pervious Area


4.4 50 0.0350 0.19 Sheet Flow, First 50Grass: Short n= 0.150 P2= 3.30"

1.6 290 0.0350 3.01 Shallow Concentrated Flow, UnpavedUnpaved Kv= 16.1 fps

6.0 340 Total


Runoff

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

0.032

0.03

0.028

0.026

0.024

0.022

0.02

0.018

0.016

0.014

0.012

0.01

0.008

0.006

0.004

0.002

0


0.03 cfs



Summary for Pond CB1: CB-1

Inflow Area = 0.465 ac, 96.00% Impervious, Inflow Depth > 0.89" for 1 inch eventInflow = 0.46 cfs @ 12.09 hrs, Volume= 0.035 afOutflow = 0.46 cfs @ 12.09 hrs, Volume= 0.035 af, Atten= 0%, Lag= 0.0 minPrimary = 0.46 cfs @ 12.09 hrs, Volume= 0.035 af

Routing by Dyn-Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrsPeak Elev= 15.01' @ 12.09 hrsFlood Elev= 23.57'

Device Routing Invert Outlet Devices#1 Primary 14.67' 12.0" Round Culvert

L= 68.0' RCP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 14.67' / 12.25' S= 0.0356 '/' Cc= 0.900 n= 0.011 Concrete pipe, straight & clean

Primary OutFlow Max=0.45 cfs @ 12.09 hrs HW=15.00' (Free Discharge)1=Culvert (Inlet Controls 0.45 cfs @ 1.97 fps)

Pond CB1: CB-1

InflowPrimary

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

0.5

0.45

0.4

0.35

0.3

0.25

0.2

0.15

0.1

0.05

0

Inflow Area=0.465 acPeak Elev=15.01'12.0"Round Culvertn=0.011L=68.0'S=0.0356 '/'

0.46 cfs0.46 cfs








Primary OutFlow Max=0.47 cfs @ 12.09 hrs HW=21.18' TW=18.96' (Dynamic Tailwater)1=Culvert (Barrel Controls 0.47 cfs @ 2.60 fps)

Pond CB2: CB-2

InflowPrimary

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

0.5

0.45

0.4

0.35

0.3

0.25

0.2

0.15

0.1

0.05

0


0.48 cfs0.48 cfs








Primary OutFlow Max=0.93 cfs @ 12.09 hrs HW=18.96' TW=18.11' (Dynamic Tailwater)1=Culvert (Outlet Controls 0.93 cfs @ 2.85 fps)

Pond CB3: CB-3

InflowPrimary

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

1

0


0.98 cfs0.98 cfs









Pond CB4: CB-4

InflowPrimary

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

1

0


1.12 cfs1.12 cfs









Pond CB5: CB-5

InflowPrimary

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

1

0


1.21 cfs1.21 cfs








Primary OutFlow Max=1.31 cfs @ 12.09 hrs HW=15.57' TW=9.73' (Dynamic Tailwater)1=Culvert (Inlet Controls 1.31 cfs @ 2.44 fps)

Pond CB6: CB-6

InflowPrimary

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

1

0


1.34 cfs1.34 cfs




Inflow Area = 0.059 ac,100.00% Impervious, Inflow Depth > 0.98" for 1 inch eventInflow = 0.06 cfs @ 12.09 hrs, Volume= 0.005 afOutflow = 0.06 cfs @ 12.09 hrs, Volume= 0.005 af, Atten= 0%, Lag= 0.0 minPrimary = 0.06 cfs @ 12.09 hrs, Volume= 0.005 af





Pond CB7: CB-7

InflowPrimary

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

0.07

0.065

0.06

0.055

0.05

0.045

0.04

0.035

0.03

0.025

0.02

0.015

0.01

0.005

0


0.06 cfs0.06 cfs









Pond CB8: CB-8

InflowPrimary

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

2

1

0


1.88 cfs1.88 cfs








Primary OutFlow Max=0.03 cfs @ 12.16 hrs HW=9.31' (Free Discharge)1=Culvert (Barrel Controls 0.03 cfs @ 1.21 fps)

Pond CB9: CB-9

InflowPrimary

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

0.032

0.03

0.028

0.026

0.024

0.022

0.02

0.018

0.016

0.014

0.012

0.01

0.008

0.006

0.004

0.002

0


0.03 cfs0.03 cfs

10408-07 BA63 Pre-DevelopedType III 24-hr 10-Year Rainfall=4.90"10408-07 BA63 Pre-Developed


Time span=0.00-24.00 hrs, dt=0.05 hrs, 481 pointsRunoff by SCS TR-20 method, UH=SCS






















Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrsType III 24-hr 10-Year Rainfall=4.90"











Runoff

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

2

1

0

Type III 24-hr 10-YearRainfall=4.90"Runoff Area=20,273 sfRunoff Volume=0.176 afRunoff Depth>4.54"Flow Length=180'Slope=0.0117 '/'Tc=6.0 minCN=97

2.16 cfs
















Runoff

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

2

1

0


2.22 cfs















Runoff

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

2

1

0


2.51 cfs













Runoff

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

0.9

0.85

0.8

0.75

0.7

0.65

0.6

0.55

0.5

0.45

0.4

0.35

0.3

0.25

0.2

0.15

0.1

0.05

0


0.81 cfs














Runoff

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

0.42

0.4

0.380.36

0.34

0.320.3

0.28

0.26

0.240.22

0.2

0.180.16

0.14

0.120.1

0.08

0.06

0.040.02

0


0.39 cfs














Runoff

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

0.85

0.8

0.75

0.7

0.65

0.6

0.55

0.5

0.45

0.4

0.35

0.3

0.25

0.2

0.15

0.1

0.05

0


0.78 cfs













Runoff

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

0.3

0.28

0.26

0.24

0.22

0.2

0.18

0.16

0.14

0.12

0.1

0.08

0.06

0.04

0.02

0


0.27 cfs















Runoff

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

2

1

0

Type III 24-hr 10-YearRainfall=4.90"Runoff Area=19,335 sfRunoff Volume=0.172 afRunoff Depth>4.66"Flow Length=205'Tc=6.0 minCN=98

2.08 cfs












6.0 340 Total


Runoff

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

1

0


1.24 cfs




Inflow Area = 0.465 ac, 96.00% Impervious, Inflow Depth > 4.54" for 10-Year eventInflow = 2.16 cfs @ 12.09 hrs, Volume= 0.176 afOutflow = 2.16 cfs @ 12.09 hrs, Volume= 0.176 af, Atten= 0%, Lag= 0.0 minPrimary = 2.16 cfs @ 12.09 hrs, Volume= 0.176 af





Pond CB1: CB-1

InflowPrimary

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

2

1

0


2.16 cfs2.16 cfs








Primary OutFlow Max=0.00 cfs @ 12.09 hrs HW=21.73' TW=22.31' (Dynamic Tailwater)1=Culvert ( Controls 0.00 cfs)

Pond CB2: CB-2

InflowPrimary

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

2

1

0


2.22 cfs2.22 cfs









Pond CB3: CB-3

InflowPrimary

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

5

4

3

2

1

0


4.73 cfs4.73 cfs









Pond CB4: CB-4

InflowPrimary

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

6

5

4

3

2

1

0


5.53 cfs5.53 cfs









Pond CB5: CB-5

InflowPrimary

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

6

5

4

3

2

1

0


5.92 cfs5.92 cfs









Pond CB6: CB-6

InflowPrimary

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

7

6

5

4

3

2

1

0


6.70 cfs6.70 cfs




Inflow Area = 0.059 ac,100.00% Impervious, Inflow Depth > 4.66" for 10-Year eventInflow = 0.27 cfs @ 12.09 hrs, Volume= 0.023 afOutflow = 0.27 cfs @ 12.09 hrs, Volume= 0.023 af, Atten= 0%, Lag= 0.0 minPrimary = 0.27 cfs @ 12.09 hrs, Volume= 0.023 af





Pond CB7: CB-7

InflowPrimary

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

0.3

0.28

0.26

0.24

0.22

0.2

0.18

0.16

0.14

0.12

0.1

0.08

0.06

0.04

0.02

0


0.27 cfs0.27 cfs









Pond CB8: CB-8

InflowPrimary

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

10

9

8

7

6

5

4

3

2

1

0


9.05 cfs9.05 cfs









Pond CB9: CB-9

InflowPrimary

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

1

0


1.24 cfs1.24 cfs

3

5

9

10

11

4

3

D D

D

GZ-1 3

5

9

10

10

11

7

3

4

3

3

2"CHERRY

DMHRIM= 16.25

INV.1=12.25INV.2=12.25DEPTH=12.25

SMHRIM= 24.68

INV.1=22.48INV.2=22.48DEPTH=22.48SMH

RIM= 24.28

INV.1=21.73INV.2=22.63INV.3=21.73DEPTH=21.73

SMHRIM= 24.50

INV.1=20.08INV.2=20.03INV.3=20.50DEPTH=20.03

SMHRIM= 24.78

INV.1=12.88INV.2=18.28INV.3=12.98INV.4=15.18INV.5=16.08

CB-3RIM= 24.24

DEPTH=16.39

INV.1=18.44INV.2=20.39

CB-2RIM= 23.66

DEPTH=18.46

INV.1=21.01INV.2=20.81

CBRIM= 28.31

DEPTH=25.01

INV.1=25.01

CB RIM= 29.11

DEPTH=26.16


CBRIM= 24.40

DEPTH=23.10


CB-1RIM= 23.57

DEPTH=14.57

INV.1=14.67INV.2=18.92

CBRIM= 13.26

DEPTH=8.86

INV.1=10.91

CBRIM= 13.41

DEPTH=10.11

INV.1=10.11INV.2=10.11

CBRIM= 13.36

DEPTH=9.36

INV.1=9.86INV.2=9.66INV.3=11.01

TBM BEL=31.07'FLAT NAILSET IN UP

TBM CEL=16.40'FLAT NAILSET IN UP

1

21

2

3

1

1

2

1

1

2

21

UP NO #

UP NO #

UP #110

UP NO #

UP #286

FDC

FFE=25.23'

FFE=25.24'

FFE=28.09'

FFE=25.35'

FFE=25.13'

FFE=25.05'

FF

12"RCP

15"RCP

8"RCP8"RCP

12"RCP

6"PVC

12"HDPE

8"CLAY

12"CLAY1

2

15"CLAY

30"PVC

1

2

3

5 4

30"CLAY

6"PVC

8"CLAY

6"PVC

1

2 3

8"CLAY

12

3

6"PVC

8"PVC

8"PVC1

2

8"PVC

16

1718

19

20

21

22

23

24

24

24

24

24 26

27

28

26 27

25

15

16 17 18 19 20

21

22

23

24

25

26

27

28

24

24

2322

212019

17

18

CC

CC

LOADING DOCK

EOP

STEPS

STEPS

BIT.PARKING

BIT.PARKING

VGCCONC. PLANTER

WRW

EOP

CONC.PAD

EOP

CRWCONC.PAD

COMM.PIT

COMM.PIT

GARAGE

BUILDING A63

EOG

SYLSTL

UP NO #

FFE=25.25' VIF

VGC

POST (TYP)

UU

DESIGN POINT "A"

RE

PLA

CE

PA

RK

ING

LO

TB

UIL

DIN

G A

-63

NA

VA

L FA

CIL

ITIE

S E

NG

INE

ER

ING

CO

MM

AN

D

PLANNORTH

C-903


NOTES:1. EXISTING CONDITIONS SHOWN HEREON FROM AN ON THE GROUND

SURVEY CONDUCTED BY WSP ON APRIL 10, 2014.

2. THE HORIZONTAL DATUM IS RHODE ISLAND STATE PLANE NAD 83 AND THEVERTICAL DATUM IS NAVD 88.

LEGEND:

SUBCATCHMENT NUMBER

SUBCATCHMENT LIMITS

24

2423

222120

19D

DGZ-7

1215

53

3

3

4

5"CE

DAR

20"O

AK

18"O

AK

20"O

AK

36"B

EECH

11"C

EDAR 16

"OAK

10"O

AK

2"CHERRY

20"O

AK

18"O

AK

15"O

AK

DMHRIM= 16.68

INV.1=10.28INV.2=10.28INV.3=10.38DEPTH=10.28

DMHRIM= 28.16

INV.1=21.46INV.2=21.66INV.3=ABANDONED

DEPTH=21.46

DMHRIM= 29.16

INV.1=CNOINV.2=21.86INV.3=21.76DEPTH=21.36

DMHRIM= 16.17

INV.1=9.37INV.2=10.27INV.3=9.37

DMHRIM= 15.80

INV.1=8.35INV.2=8.35INV.3=8.35

SMHRIM= 24.68

INV.1=22.48INV.2=22.48DEPTH=22.48SMH

RIM= 24.28

INV.1=21.73INV.2=22.63INV.3=21.73DEPTH=21.73

CBRIM= 29.08

DEPTH=19.08

INV.1=24.58INV.2=22.28INV.3=24.58INV.4=22.08

INV

CBRIM= 13.36

DEPTH=9.36

INV.1=9.86INV.2=9.66INV.3=11.01

CB-11RIM= 14.62

DEPTH=8.52

INV.1=10.17INV.2=10.07

CB-10RIM= 15.60

DEPTH=9.45

INV.1=9.50INV.2=9.45

CB-9RIM= 16.21

DEPTH=8.76

INV.1=9.21INV.2=12.51

CB-8RIM= 18.62

DEPTH=8.72

INV.1=9.17INV.2=11.92INV.3=14.02

CB-7RIM= 18.38

DEPTH=9.38INV.1=13.53INV.2=14.71

CB-6RIM= 22.66

DEPTH=14.96

INV.1=15.06INV.2=17.16

CB-5RIM= 23.57

DEPTH=16.57

INV.1=17.07INV.2=17.17INV.3=17.17

CB-4RIM= 24.05

DEPTH=15.55

INV.1=17.35INV.2=17.45INV.3=NPV

TBM AEL=31.82'CHISELED SQUARE

ON CONC. BASE

TBM DEL=21.51'FLAT NAILSET IN UP

CBRIM= 13.36

DEPTH=10.91

INV.1=11.31INV.2=11.11INV.3=11.41

2

3

1

1

2

3

12

12

1

2

1

2

3

2

1

21

41

2

3

1

2

1

2

3

UP NO #

UP NO #

UP #284

UP #83

UP #282

UP #281

FDC

FDCFDC

FDC

FFE=25.23'

FFE=25.24'

FFE=25.05'

FFE=25.15'

FFE=25.28'

FFE=25.18'

FFE=25.12'

FFE=25.22'FFE=25.20'

FFE=25.26'

FFE=25.23'

FFE=25.12'

8"RCP

6"CLAY

8"RCP

6"CLAY10"RCP

10"RCP

10"RCP

10"CI

12"RCP

RCP

18"RCP12"RCP

12"RCP

12"RCP

15"RCP

4"PVC18"HDPE

18"HDPE4"PVC

12

3

18"CLA

Y

1

2

3

24"CLAY

1 2

3

33"RCP

33"RCP33"RCP

33"RCP

4"PVC

36"HDPE

12

3

36"HDPE1

2

31

8"PVC

2526

2728

30

24

24

23

2221

20

18

17

16

15

28

2726

2422

21

19 20

17

CC

CC

BC

EOC

CONC.

PAD

CONC.

PAD

PROPANETANK

EOC

CONC. PAD

W/ TRANSFORMER

CRWCRW

WOOD DECK

STEPS

STEPS

BROKEN PAVEMENT

BIT.PARKING

VGC

VGC

CC

CONC. PLANTER

COMM.PIT

CONC.

PADSTEPS

CRW

CRW

BUILDING A63

CODDINGTON WAY

SYLSTL

24"

29

3

UU

DESIGN POINT "B"

DESIGN POINT "C"

RE

PLA

CE

PA

RK

ING

LO

TB

UIL

DIN

G A

-63

NA

VA

L FA

CIL

ITIE

S E

NG

INE

ER

ING

CO

MM

AN

D

PLANNORTH

C-904


NOTES:1. EXISTING CONDITIONS SHOWN HEREON FROM AN ON THE

GROUND SURVEY CONDUCTED BY WSP ON APRIL 10, 2014.

2. THE HORIZONTAL DATUM IS RHODE ISLAND STATE PLANENAD 83 AND THE VERTICAL DATUM IS NAVD 88.

LEGEND:

SUBCATCHMENT NUMBER

SUBCATCHMENT LIMITS

Total Area 122954 Sq. Feet 2.82 AcresPost-DevelopmentSubcatchments Sq. Feet AcresC10 20273.00 0.465 Sq. Feet AcresTO DESIGN POINT "A" Pave 18754.00 0.431 Impervious Area (I) 19463.00 0.447

Roof 709.00 0.016 % Impervious 96 %Grass 810.00 0.019Gravel 0.00 0.000

20273.00C20 20819.00 0.478

Pave 12618.00 0.290 Impervious Area (I) 19464.00 0.447Roof 6846.00 0.157 % Impervious 93 %Grass 1355.00 0.031

20819.00C30 23719.00 0.545


23719.00C40 7836.00 0.180


7836.00C50 3609.00 0.083


3609.00C60 7579.00 0.174


7579.00C70 2549.00 0.059


2549.00C80 19335.00 0.444TO DESIGN POINT "B" Pave 16860.00 0.387 Impervious Area (I) 16860.00 0.387

Roof 0.00 0.000 % Impervious 87 %Grass 2475.00 0.057Gravel 0.00 0.000

19335.00C90 17235.00 0.396TO DESIGN POINT "C" Pave 0.00 0.000 Impervious Area (I) 0.00 0.000

Roof 0.00 0.000 % Impervious %Grass 17235.00 0.396Gravel 0.00 0.000

17235.00

Total 122954.00 2.823 Impervious Area (I) 95240.00 2.186% Impervious 77 %

Hydrologic Soil Group Coefficient (F) Recharge Volume (Rev) = (1")(F)(I)/12 * 50%A 0.6 DESIGN POINT "A" 202.74 Cu. FeetB 0.35 DESIGN POINT "B" 789.34 Cu. FeetC 0.25 DESIGN POINT "C" 0.00 Cu. FeetD 0.1

Water Quality Volume (Wqv) = (1")*(I)/12 *50%DESIGN POINT "A" 810.96 Cu. FeetDESIGN POINT "B" 3157.38 Cu. FeetDESIGN POINT "C" 0.00 Cu. Feet

Rev is considered part of WQV use the larger of the two. Reduce by 50% due to site being considered a redevelopment site.

C10

Subcatchment 10

C20

Subcatchment 20

C30

Subcatchment 30

C40

Subcatchment 40C50

Subcatchment 50

C60

Subcatchment 60

C70

Subcatchment 70

C80

Subcatchment 80

C90

Subcatchment 90

1P

Retention Gallery 1

2P

Retention Gallery 2

CB1CB

CB-1

CB2CB

CB-2

CB3CB

CB-3

CB4CB

CB-4

CB5CB

CB-5

CB6CB

CB-6

CB7CB

CB-7

CB8CB

CB-8

CB9CB

CB-9

DMH1CB

DMH-1

DMH2CB

DMH-2

Drainage Diagram for 10408-07 BA63 Post-Developed Rev 1Prepared by Microsoft, Printed 9/11/2014

HydroCAD® 9.10 s/n 02940 © 2010 HydroCAD Software Solutions LLC

Subcat Reach Pond Link

10408-07 BA63 Post-Developed Rev 1 Printed 9/11/2014Prepared by Microsoft

Page 2HydroCAD® 9.10 s/n 02940 © 2010 HydroCAD Software Solutions LLC

Area Listing (all nodes)

Area(acres)

CN Description(subcatchment-numbers)

0.636 79 50-75% Grass cover, Fair, HSG C (C10, C20, C30, C40, C60, C80, C90)1.564 98 Paved parking, HSG C (C10, C20, C30, C40, C50, C60, C70, C80)0.622 98 Unconnected roofs, HSG C (C10, C20, C30, C40)

2.823 TOTAL AREA

10408-07 BA63 Post-Developed Rev 1 Printed 9/11/2014Prepared by Microsoft


Soil Listing (all nodes)

Area(acres)

SoilGroup

SubcatchmentNumbers

0.000 HSG A0.000 HSG B

2.823 HSG C C10, C20, C30, C40, C50, C60, C70, C80, C900.000 HSG D0.000 Other2.823 TOTAL AREA

Type III 24-hr 1 INCH Rainfall=1.20"10408-07 BA63 Post-Developed Rev 1 Printed 9/11/2014Prepared by Microsoft


Time span=0.00-24.00 hrs, dt=0.05 hrs, 481 points x 2Runoff by SCS TR-20 method, UH=SCS











Peak Elev=20.86' Storage=0.017 af Inflow=0.46 cfs 0.035 afPond 1P: Retention Gallery 1 Discarded=0.01 cfs 0.008 af Primary=0.15 cfs 0.011 af Outflow=0.16 cfs 0.018 af













Peak Elev=21.06' Inflow=0.46 cfs 0.035 afPond DMH1: DMH-110.0" Round Culvert n=0.013 L=10.0' S=0.1120 '/' Outflow=0.46 cfs 0.035 af







Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrsType III 24-hr 1 INCH Rainfall=1.20"











Runoff

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

0.520.5

0.480.460.440.42

0.40.380.360.340.32

0.30.280.260.240.22

0.20.180.160.140.12

0.10.080.060.040.02

0

Type III 24-hr 1 INCHRainfall=1.20"Runoff Area=20,273 sfRunoff Volume=0.035 afRunoff Depth>0.89"Flow Length=180'Slope=0.0117 '/'Tc=6.0 minCN=97

0.46 cfs
















Runoff

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

0.5

0.45

0.4

0.35

0.3

0.25

0.2

0.15

0.1

0.05

0


0.48 cfs















Runoff

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

0.55

0.5

0.45

0.4

0.35

0.3

0.25

0.2

0.15

0.1

0.05

0


0.50 cfs













Runoff

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

0.15

0.14

0.13

0.12

0.11

0.1

0.09

0.08

0.07

0.06

0.05

0.04

0.03

0.02

0.01

0


0.14 cfs














Runoff

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

0.095

0.09

0.085

0.08

0.075

0.07

0.065

0.06

0.055

0.05

0.045

0.04

0.035

0.03

0.025

0.02

0.015

0.01

0.005

0


0.09 cfs














Runoff

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

0.120.115

0.110.105

0.10.095

0.090.085

0.080.075

0.070.065

0.060.055

0.050.045

0.040.035

0.030.025

0.020.015

0.010.005

0


0.11 cfs













Runoff

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

0.07

0.065

0.06

0.055

0.05

0.045

0.04

0.035

0.03

0.025

0.02

0.015

0.01

0.005

0


0.06 cfs















Runoff

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

0.440.42

0.40.380.360.340.32

0.30.280.260.240.22

0.20.180.160.140.12

0.10.080.060.040.02

0

Type III 24-hr 1 INCHRainfall=1.20"Runoff Area=19,335 sfRunoff Volume=0.030 afRunoff Depth>0.81"Flow Length=205'Tc=6.0 minCN=96

0.41 cfs












6.0 340 Total


Runoff

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

0.032

0.03

0.028

0.026

0.024

0.022

0.02

0.018

0.016

0.014

0.012

0.01

0.008

0.006

0.004

0.002

0


0.03 cfs



Summary for Pond 1P: Retention Gallery 1

Inflow Area = 0.465 ac, 96.00% Impervious, Inflow Depth > 0.89" for 1 INCH eventInflow = 0.46 cfs @ 12.09 hrs, Volume= 0.035 afOutflow = 0.16 cfs @ 12.41 hrs, Volume= 0.018 af, Atten= 66%, Lag= 19.5 minDiscarded = 0.01 cfs @ 9.15 hrs, Volume= 0.008 afPrimary = 0.15 cfs @ 12.41 hrs, Volume= 0.011 af

Routing by Dyn-Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs / 2Peak Elev= 20.86' @ 12.41 hrs Surf.Area= 0.020 ac Storage= 0.017 afFlood Elev= 20.87' Surf.Area= 0.020 ac Storage= 0.017 af

Plug-Flow detention time= 192.5 min calculated for 0.018 af (53% of inflow)Center-of-Mass det. time= 84.3 min ( 879.6 - 795.4 )

Volume Invert Avail.Storage Storage Description#1A 19.25' 0.012 af 21.60'W x 41.33'L x 1.88'H Field A

0.038 af Overall - 0.010 af Embedded = 0.029 af x 40.0% Voids#2A 19.58' 0.007 af ADS N-12 12 x 20 Inside #1

Inside= 12.2"W x 12.2"H => 0.81 sf x 20.00'L = 16.2 cfOutside= 14.5"W x 14.5"H => 1.05 sf x 20.00'L = 20.9 cf

0.019 af Total Available Storage

Storage Group A created with Chamber Wizard

Device Routing Invert Outlet Devices#1 Discarded 19.25' 0.270 in/hr Exfiltration over Surface area #2 Primary 20.80' 4.0' long x 0.5' breadth Broad-Crested Rectangular Weir

Head (feet) 0.20 0.40 0.60 0.80 1.00 Coef. (English) 2.80 2.92 3.08 3.30 3.32

Discarded OutFlow Max=0.01 cfs @ 9.15 hrs HW=19.27' (Free Discharge)1=Exfiltration (Exfiltration Controls 0.01 cfs)

Primary OutFlow Max=0.15 cfs @ 12.41 hrs HW=20.86' (Free Discharge)2=Broad-Crested Rectangular Weir (Weir Controls 0.15 cfs @ 0.66 fps)



Pond 1P: Retention Gallery 1

InflowOutflowDiscardedPrimary

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

0.5

0.45

0.4

0.35

0.3

0.25

0.2

0.15

0.1

0.05

0

Inflow Area=0.465 acPeak Elev=20.86'Storage=0.017 af

0.46 cfs

0.16 cfs

0.01 cfs

0.15 cfs




Inflow Area = 1.202 ac, 90.49% Impervious, Inflow Depth > 0.82" for 1 INCH eventInflow = 1.12 cfs @ 12.09 hrs, Volume= 0.082 afOutflow = 0.70 cfs @ 12.21 hrs, Volume= 0.083 af, Atten= 38%, Lag= 7.0 minDiscarded = 0.02 cfs @ 12.15 hrs, Volume= 0.002 afPrimary = 0.68 cfs @ 12.21 hrs, Volume= 0.080 af


Plug-Flow detention time= (not calculated: outflow precedes inflow)Center-of-Mass det. time= 1.0 min ( 804.6 - 803.6 )








#3 Primary 17.30' 4.0" Vert. Orifice/Grate C= 0.600


Primary OutFlow Max=0.68 cfs @ 12.21 hrs HW=20.18' TW=17.56' (Dynamic Tailwater)2=Broad-Crested Rectangular Weir ( Controls 0.00 cfs)3=Orifice/Grate (Orifice Controls 0.68 cfs @ 7.79 fps)





Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

1

0


1.12 cfs

0.70 cfs

0.02 cfs

0.68 cfs




Inflow Area = 0.465 ac, 96.00% Impervious, Inflow Depth > 0.89" for 1 INCH eventInflow = 0.46 cfs @ 12.09 hrs, Volume= 0.035 afOutflow = 0.46 cfs @ 12.09 hrs, Volume= 0.035 af, Atten= 0%, Lag= 0.0 minPrimary = 0.46 cfs @ 12.09 hrs, Volume= 0.035 af

Routing by Dyn-Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs / 2Peak Elev= 21.26' @ 12.09 hrsFlood Elev= 23.57'




Pond CB1: CB-1

InflowPrimary

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

0.5

0.45

0.4

0.35

0.3

0.25

0.2

0.15

0.1

0.05

0


0.46 cfs0.46 cfs









Pond CB2: CB-2

InflowPrimary

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

0.5

0.45

0.4

0.35

0.3

0.25

0.2

0.15

0.1

0.05

0


0.48 cfs0.48 cfs









Pond CB3: CB-3

InflowPrimary

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

1

0


0.98 cfs0.99 cfs









Pond CB4: CB-4

InflowPrimary

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

1

0


1.13 cfs1.12 cfs









Pond CB5: CB-5

InflowPrimary

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

0.85

0.8

0.75

0.7

0.65

0.6

0.55

0.5

0.45

0.4

0.35

0.3

0.25

0.2

0.15

0.1

0.05

0


0.76 cfs0.76 cfs









Pond CB6: CB-6

InflowPrimary

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

0.95

0.9

0.85

0.8

0.75

0.7

0.65

0.6

0.55

0.5

0.45

0.4

0.35

0.3

0.25

0.2

0.15

0.1

0.05

0


0.87 cfs0.87 cfs




Inflow Area = 0.059 ac,100.00% Impervious, Inflow Depth > 0.98" for 1 INCH eventInflow = 0.06 cfs @ 12.09 hrs, Volume= 0.005 afOutflow = 0.06 cfs @ 12.09 hrs, Volume= 0.005 af, Atten= 0%, Lag= 0.0 minPrimary = 0.06 cfs @ 12.09 hrs, Volume= 0.005 af





Pond CB7: CB-7

InflowPrimary

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

0.07

0.065

0.06

0.055

0.05

0.045

0.04

0.035

0.03

0.025

0.02

0.015

0.01

0.005

0


0.06 cfs0.06 cfs









Pond CB8: CB-8

InflowPrimary

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

1

0


1.34 cfs1.34 cfs









Pond CB9: CB-9

InflowPrimary

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

0.032

0.03

0.028

0.026

0.024

0.022

0.02

0.018

0.016

0.014

0.012

0.01

0.008

0.006

0.004

0.002

0


0.03 cfs0.03 cfs



Summary for Pond DMH1: DMH-1




L= 10.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 20.70' / 19.58' S= 0.1120 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior


Pond DMH1: DMH-1

InflowPrimary

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

0.5

0.45

0.4

0.35

0.3

0.25

0.2

0.15

0.1

0.05

0


0.46 cfs0.46 cfs









Pond DMH2: DMH-2

InflowPrimary

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

1

0


1.12 cfs1.12 cfs

Type III 24-hr 10-Year Rainfall=4.90"10408-07 BA63 Post-Developed Rev 1 Printed 9/11/2014Prepared by Microsoft


Time span=0.00-24.00 hrs, dt=0.05 hrs, 481 points x 2Runoff by SCS TR-20 method, UH=SCS

































Runoff

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

2

1

0


2.16 cfs
















Runoff

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

2

1

0


2.22 cfs















Runoff

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

2

1

0


2.51 cfs













Runoff

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

0.9

0.85

0.8

0.75

0.7

0.65

0.6

0.55

0.5

0.45

0.4

0.35

0.3

0.25

0.2

0.15

0.1

0.05

0


0.81 cfs














Runoff

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

0.42

0.4

0.380.36

0.34

0.320.3

0.28

0.26

0.240.22

0.2

0.180.16

0.14

0.120.1

0.08

0.06

0.040.02

0


0.39 cfs














Runoff

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

0.8

0.75

0.7

0.65

0.6

0.55

0.5

0.45

0.4

0.35

0.3

0.25

0.2

0.15

0.1

0.05

0


0.76 cfs













Runoff

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

0.3

0.28

0.26

0.24

0.22

0.2

0.18

0.16

0.14

0.12

0.1

0.08

0.06

0.04

0.02

0


0.27 cfs















Runoff

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

2

1

0

Type III 24-hr 10-YearRainfall=4.90"Runoff Area=19,335 sfRunoff Volume=0.164 afRunoff Depth>4.43"Flow Length=205'Tc=6.0 minCN=96

2.04 cfs












6.0 340 Total


Runoff

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

1

0


1.24 cfs




Inflow Area = 0.465 ac, 96.00% Impervious, Inflow Depth > 4.54" for 10-Year eventInflow = 2.16 cfs @ 12.09 hrs, Volume= 0.176 afOutflow = 2.17 cfs @ 12.10 hrs, Volume= 0.160 af, Atten= 0%, Lag= 0.6 minDiscarded = 0.01 cfs @ 3.10 hrs, Volume= 0.010 afPrimary = 2.16 cfs @ 12.10 hrs, Volume= 0.150 af


Plug-Flow detention time= 79.2 min calculated for 0.160 af (91% of inflow)Center-of-Mass det. time= 33.0 min ( 788.7 - 755.8 )









Primary OutFlow Max=2.15 cfs @ 12.10 hrs HW=21.13' (Free Discharge)2=Broad-Crested Rectangular Weir (Weir Controls 2.15 cfs @ 1.64 fps)





Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

2

1

0


2.16 cfs2.17 cfs

0.01 cfs

2.16 cfs




Inflow Area = 1.202 ac, 90.49% Impervious, Inflow Depth > 4.44" for 10-Year eventInflow = 5.46 cfs @ 12.08 hrs, Volume= 0.445 afOutflow = 4.60 cfs @ 12.17 hrs, Volume= 0.446 af, Atten= 16%, Lag= 5.0 minDiscarded = 0.02 cfs @ 11.75 hrs, Volume= 0.010 afPrimary = 4.58 cfs @ 12.17 hrs, Volume= 0.436 af


Plug-Flow detention time= (not calculated: outflow precedes inflow)Center-of-Mass det. time= 15.4 min ( 776.8 - 761.4 )








#3 Primary 17.30' 4.0" Vert. Orifice/Grate C= 0.600


Primary OutFlow Max=4.22 cfs @ 12.17 hrs HW=22.04' TW=19.13' (Dynamic Tailwater)2=Broad-Crested Rectangular Weir (Weir Controls 3.50 cfs @ 1.97 fps)3=Orifice/Grate (Orifice Controls 0.72 cfs @ 8.23 fps)





Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

6

5

4

3

2

1

0


5.46 cfs

4.60 cfs

0.02 cfs

4.58 cfs









Pond CB1: CB-1

InflowPrimary

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

2

1

0


2.16 cfs2.16 cfs









Pond CB2: CB-2

InflowPrimary

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

2

1

0


2.22 cfs2.22 cfs









Pond CB3: CB-3

InflowPrimary

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

5

4

3

2

1

0


4.73 cfs4.66 cfs









Pond CB4: CB-4

InflowPrimary

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

6

5

4

3

2

1

0


5.46 cfs5.46 cfs









Pond CB5: CB-5

InflowPrimary

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

5

4

3

2

1

0


4.86 cfs4.86 cfs









Pond CB6: CB-6

InflowPrimary

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

6

5

4

3

2

1

0


5.42 cfs5.42 cfs




Inflow Area = 0.059 ac,100.00% Impervious, Inflow Depth > 4.66" for 10-Year eventInflow = 0.27 cfs @ 12.09 hrs, Volume= 0.023 afOutflow = 0.27 cfs @ 12.09 hrs, Volume= 0.023 af, Atten= 0%, Lag= 0.0 minPrimary = 0.27 cfs @ 12.09 hrs, Volume= 0.023 af





Pond CB7: CB-7

InflowPrimary

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

0.3

0.28

0.26

0.24

0.22

0.2

0.18

0.16

0.14

0.12

0.1

0.08

0.06

0.04

0.02

0


0.27 cfs0.27 cfs









Pond CB8: CB-8

InflowPrimary

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

7

6

5

4

3

2

1

0


7.14 cfs7.14 cfs









Pond CB9: CB-9

InflowPrimary

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

1

0


1.24 cfs1.24 cfs







L= 10.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 20.70' / 19.58' S= 0.1120 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior


Pond DMH1: DMH-1

InflowPrimary

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

2

1

0


2.16 cfs2.16 cfs









Pond DMH2: DMH-2

InflowPrimary

Hydrograph

Time (hours)2423222120191817161514131211109876543210

Flo

w (

cfs)

6

5

4

3

2

1

0


5.46 cfs5.46 cfs

Watermark

APPENDIX B

Soil Management Plan

Watermark

APPENDIX C

Geotechnical Engineering Report

June 11, 2014; Revised October 9, 2014

GZA Engineers and GeoEnvironmental, Inc. Scientists

Copyright 2014 GZA GeoEnvironmental, Inc.

372 Merrimac Street Newburyport, MA 01950 Office: 781-278-4800 Fax: 978-465-1428 www.gza.com

June 11, 2014 GZA File No. 18.0171977.00 Robert B. Blanchette, Jr., P.E. Watermark Environmental, Inc. 175 Cabot Street Lowell, Massachusetts 01854 Re: Geotechnical Engineering Report Replace Parking Lot – Building A-63 Newport, Rhode Island Dear Mr. Blanchette: In accordance with our agreement dated April 11, 2014, GZA GeoEnvironmental, Inc. (GZA) is pleased to submit to Watermark Environmental, Inc. (Watermark; Client) this geotechnical engineering report for the proposed Parking Lot Repairs at Building A-63, Naval Station Newport, Newport, Rhode Island (Site) for Watermark’s Prime Contract No. N40085-10-D-9431 Task Order No. 7 with the Naval Facilities Engineering Command (NAVFAC). The objective of our geotechnical work during the Design Phase was to evaluate subsurface conditions and develop pavement design and construction recommendations. This report is subject to the Limitations set forth in Appendix A and the Terms and Conditions of our agreement. Elevations cited in this report are referenced to the North American Vertical Datum of 1988 (NAVD 1988). BACKGROUND

Our understanding of the project is based on our work at the Site, our correspondence with you and an undated plan provided by Watermark titled “Replace Parking Lot, Building A-63, Naval Station Newport, Newport, RI, Boring Location Plan”. Existing Conditions

The site is located along the northern side of Coddington Highway at the Newport, Rhode Island Naval Station. The Site is occupied by a one-story structure (Building A63) which is generally located in the center of the Site. The majority of the Site to the north, east and south of Building A63 is paved with bituminous asphalt. In most locations, the asphalt is considerably distressed. Grades in most of the paved areas are generally level at about elevation 24 feet. The Site is accessed via paved driveways in the northeastern and southwestern corners of the Site. Grades at the northeastern driveway slope from about elevation 28 to 24 feet. Grades at the southwestern driveway slope from about elevation 16 to 24 feet. Several concrete pads supporting various equipment (i.e. tanks, transformers) are located throughout the paved areas. In addition, about 60 feet of railroad tracks are located at the surface to the north of the building. Existing conditions are shown on Figure 1.

Proposed Site Improvements

Proposed Site improvements will include the removal and replacement of the pavement at parking access roads adjacent to and around Building A-63. The approximate limit of proposed pavement replacement is indicated on Figure 1. We understand grades for the new pavement will

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Watermark Environmental, Inc. June 11, 2014 GZA No. 171977.00 Page 2 essentially match existing grades. We anticipate that portions of the proposed parking area will be designed for truck use and some areas will be designed for passenger cars only. We assume the existing railroad tracks will be removed during construction. In addition, subsurface storm water infiltration areas are proposed in the northwestern and south eastern corners of the Site. GZA’s scope of work is limited to pavement recommendations. SCOPE OF SERVICES GZA performed the following scope of services:

1. Coordinated a subsurface exploration program consisting of seven soil borings to evaluate subsurface conditions around the Building A-63 parking lot.

2. Performed four gradation analyses on samples collected from the explorations to confirm field classifications and assist in evaluating reuse potential.

3. Performed engineering analyses, developed geotechnical design and construction recommendations, and prepared this report summarizing our findings.

SUBSURFACE EXPLORATIONS

GZA subcontracted New Hampshire Boring of Brockton, Massachusetts to perform seven

soil borings (GZ-1 through GZ-7) in proposed pavement replacement areas on May 7, 2014. Borings were performed using a truck-mounted drill rig. Borings GZ-2 and GZ-5 were performed in the general areas of proposed subsurface storm water discharge areas and carried to depths of 10 feet. The remaining borings were each carried to 6 feet. The borings were backfilled with cuttings and patched at the surface with cold-patch asphalt. Standard Penetration Tests (SPTs) were performed and split spoon samples were obtained continuously in the borings.

GZA field representatives observed the soil borings and classified the soil samples using

the modified Burmister Classification System. The boring logs are attached as Appendix B. GEOTECHNICAL LABORATORY TESTING

Four soil samples obtained from the recent explorations were submitted to GZA’s geotechnical laboratory subcontractor, Thielsch Engineering, for grain size distribution analyses to confirm field classifications and assist in evaluating reuse potential of the soil. Laboratory test results for samples taken from the recent borings are attached as Appendix C.

SUBSURFACE CONDITIONS

The soil strata encountered in the recent soil borings are described further in detail below:

Asphalt – With the exception of boring GZ-1, bituminous asphalt was encountered at the surface of each boring. The thickness of the asphalt ranged from 1 to 2 inches.

Fill – Based on the borings, there is not a consistent layer of typical pavement base course

fill (well-graded, free-draining) throughout the existing paved areas. Soil that would

Watermark Environmental, Inc. June 11, 2014 GZA No. 171977.00 Page 3

marginally meet the typical criteria for pavement base course fill was encountered in boring GZ-3 at a thickness of 5 inches, GZ-5 at a thickness of 13 inches and GZ-6 at a thickness of 12 inches. The fill described above generally consisted of brown fine to coarse sand with up to 35 percent gravel and about 10 to 15 percent silt. While this material is generally well-graded, we typically recommend that base course fill contain less than 8 percent silt.

The remaining fill generally consisted of medium dense to very dense, gray-brown, fine to coarse sand with up to 50 percent silt and up to 35 percent gravel. In GZ-1, GZ-2, and GZ-6, the gravel component of some samples was a completely weathered shale-like mineral. Soil encountered directly below the asphalt at borings GZ-1, GZ-2, GZ-4, and GZ-7 was not a typical base course material because of its relatively high silt content and low gravel content, and may have contributed to the pavement distress. Overall, fill was encountered to depths of 1 to at least 6 feet. The fill was not fully penetrated in boring GZ-4 which was carried to a depth of 6 feet.

Silty Sand – With the exception of GZ-4, natural silty sand was encountered below the fill

in each of the borings. The silty sandy generally consisted of brown, fine to medium sand with up to 50 percent silt with up to 35 percent gravel (but mostly less than 10 percent).

Groundwater

Groundwater depth was measured during drilling after little or no stabilization time.

Groundwater depth was measured in borings GZ-2, GZ-5 and GZ-6 at depths of about 5.5 to 9.5 feet. These depths correspond to elevations ranging from about elevation 14.5 to 18.5 feet. Groundwater was not encountered in borings GZ-1, GZ-3, GZ-4, or GZ-7.

Note that fluctuations in observed groundwater levels will occur due to variations in precipitation, temperature and other factors different from those existing at the time the measurements were made. RECOMMENDATIONS The existing pavement was observed to be highly distressed. In our opinion, this is primarily due to the relatively thin layer of existing asphalt and lack of free-draining base course. An adequate layer of free-draining base course fill (Sand-Gravel) was not encountered in most of the explorations which likely contributed to the poor performance of the existing pavement. While the material directly below the existing pavement in borings GZ-3, GZ-5 and GZ-6 is generally well-graded with a silt content of about 10 to 15 percent, we typically recommend that base course fill contain less than 8 percent silt. In our opinion this 10 to 15 silt content would likely have made the existing pavement susceptible to frost-heaving over the years. The geotechnical design and construction recommendations presented below are based on our evaluation of the available data and design concepts provided to GZA and are subject to the Limitations contained in Appendix A. The nature and extent of variations between subsurface explorations may not become evident until construction. If variations then appear evident, it will be necessary to reevaluate the recommendations of this report.

Watermark Environmental, Inc. June 11, 2014 GZA No. 171977.00 Page 4 DESIGN

1. Pavement Cross-Sections

Our pavement recommendations presented below are based on the criteria set forth in the “Unified Facilities Criteria, Pavement Design for Roads, Streets, Walks, and Open Storage Areas, UFC 3-250-01FA”, dated January 16, 2004. We understand the paved areas will be accessed primarily by passenger vehicles and light duty vans. However, it is expected that larger trucks will also access the northern portion of the Site to make deliveries to loading dock areas at the northern side of Building A-63. Our analyses assumed these areas to correspond to Categories I and II based on the definitions in UFC 3-250-01-01FA:

a. Category I: traffic composed primarily of passenger cars, panel and pickup trucks, but not containing more than one percent two-axle trucks; and

b. Category III: traffic containing as much as 15 percent trucks, but with not more than one percent of the total traffic composed of trucks having three or more axles.

Based on the criteria set forth in UFC 3-250-01FA, the minimum cross-section of pavement and underlying base course is 13.5 inches for Category I Traffic and 18 inches for Category II traffic. Accordingly, GZA recommends the minimum thickness for each material layer is presented below:


Minimum Thickness Car Parking

(Category I) Truck Loading (Category III)

Finish Course 1.5 inches 1.5 inches Binder Course 2 inches 2.5 inches Sand-Gravel Base Course 10 inches 14 inches

Finish course and binder course should adhere to one of the three gradation requirements set forth in UFC 3-250-03, Standard Practice Manual for Flexible Pavements, Table 2-1. We understand the Owner may be interested in a more economic cross-section. Based on our experience, the cross-section presented below would perform reasonably well for light duty use:

Reasonable Minimum Pavement Cross-Section for Light-Duty

Finish Course 1.5 inches Binder Course 1.5 inches Sand-Gravel Base Course 9 inches

Light duty is considered 2-axle, 4-wheel passenger vehicles (cars, pick-up trucks, vans).

Watermark Environmental, Inc. June 11, 2014 GZA No. 171977.00 Page 5 2. Pavement Base Course Gradation

We recommend the following gradations for pavement base course fill:

Sieve Size Percent Finer by Weight

3 inch 100 1/2 inch 50-85

No. 4 40-75 No. 10 20-50 No. 40 10-35 No. 200 0-8

Based on visual classifications and laboratory results, most of the soil underlying the existing pavement, does not meet the recommended gradation requirement above. Whereas, finish grades of the proposed pavement will match those of the existing pavement, a cut will be required throughout the proposed parking lot to accommodate the recommended cross-sections. Our visual classification of the fill encountered directly below the pavement in borings GZ-3, GZ-5 and GZ-7 is based on relatively small amounts of sample obtained from spilt spoons. There may be more areas where fill, that generally meets our recommended gradation criteria for base course fill, is present under the existing pavement. This fill could possibly be reused as base course below the new pavement. The existing pavement could be reclaimed for possible reuse as pavement base course provided it can be processed to meet the gradation requirement shown above. If reclaiming were extended into the underlying fill, we do not anticipate that the composite fill of reclaimed asphalt mixed with underlying fill at most areas would be suitable to reuse as base course as the silt content of the existing fill is relatively high. Whereas the existing pavement is only 1 to 2 inches thick, it may not be practical to excavate the reclaimed asphalt separately from the fill for reuse as base course. Therefore, we anticipate the existing fill and pavement will need to be exported from the Site as it does not appear as though there is adequate area on Site for these materials.

CONSTRUCTION

1. Pavement Subgrade Preparation

Remove existing pavement and fill to the minimum depth required to accommodate Finish, Binder and Sand-Gravel Base courses. Existing fill below the bottom of excavation may be left in place provided the subgrade is proof-compacted with a minimum of six passes of a vibratory drum roller (with a minimum static drum weight of 10,000-pounds capable of at least 20,000 pounds of dynamic force). Any weak or soft spots identified during proof-compacting should be excavated and replaced with compacted base course fill.

Base course fill should be placed in lifts no greater than 12-inches-thick and compacted with at least six passes of a ride-on vibratory roller. The recommended minimum compaction is 95 percent based on percentage of maximum dry density as defined by ASTM D-1557 Method C.

Watermark Environmental, Inc. June 11, 2014 GZA No. 171977.00 Page 6

Frozen soil should not be placed as fill. In addition, fill should not be placed over frozen soil.

CONCLUSIONS

We understand that it is desirable to minimize the pavement cross-section thickness (including base course) primarily so that the amount of fill to be exported from the Site is minimized. The pavement cross-section recommended based on the criteria set forth in UFC 3-250-01FA UFC Code will perform better than the alternate pavement cross-section provided. However, if the paved areas are primarily used by light-duty vehicles, we anticipate that the pavement would perform reasonably well. Watermark and the Owner should anticipate some additional long-term maintenance of the proposed parking area if the alternative pavement cross-section is selected. In three of the seven borings, fill (at thicknesses of 5 to 13 inches) directly below the pavement was generally well-graded and relatively free-draining. While this material generally contains a higher percentage of silt than our recommended gradation criteria for base course fill, some of this fill may be acceptable for reuse as base course if mixed with an imported Sand-Gravel Fill. We believe it would be advantageous for Watermark to perform several shallow test pits during construction to better evaluate the extent, thickness and composition of this fill.

FINAL DESIGN AND CONSTRUCTION

We trust that the information presented herein addresses your needs related to the pavement design. GZA is presently under contract to prepare technical specifications and review near final plans as they relate to the geotechnical aspects of the project. GZA should be present at the Site during construction to observe earthwork operations, evaluate subgrade stability and gradation, and observe placement and compaction of fill for compliance with our recommendations. We recommend that GZA be engaged to observe construction-phase test pits so that the fill underlying the existing pavement may be better evaluated. Should areas of the parking area already contain a suitable base course with respect to thickness and composition, the amount of fill to be exported from the Site could be minimized. We have enjoyed working with you on this project and would look forward to our continued involvement. Please call Derek Schipper at 781-278-5792 or Anders Bjarngard at 781-278-4802 should you have any questions.

Watermark Environmental, Inc. June 11, 2014 GZA No. 171977.00 Page 7 Very truly yours, GZA GEOENVIRONMENTAL, INC. Derek J. Schipper, P.E. Bruce Fairless, P.E. Senior Project Manager Consultant/Reviewer Anders B. Bjarngard, P.E. Principal Attachments: Figure 1– Boring Location Plan

Appendix A – Limitations Appendix B – Boring Logs

Appendix C – Geotechnical Laboratory Results \\GZANEWBURYPT\Jobs\171900's\18.0171977.00\Report\171977-00-r01.docx

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APPENDIX A

LIMITATIONS

LIMITATIONS

Subsurface Conditions1. The generalized soil profile(s) provided in our Report and on our subsurface exploration logs are

intended only to convey trends in subsurface conditions. The boundaries between strata are approximateand idealized, and were based on our assessment of subsurface conditions. The composition of strata,and the transitions between strata, may be more variable and more complex than indicated. For morespecific information on soil conditions at a specific location refer to the exploration logs.

2. Water level readings have been made in explorations at the specified times and under the statedconditions. These data have been reviewed and interpretations have been made in this Report.However, fluctuations in the level of the groundwater occur due to temporal or spatial variations in arealrecharge rates, soil heterogeneities, the presence of subsurface utilities, and/or natural or artificiallyinduced perturbations. The observed water table may be other than indicated in the Report

Compliance with Codes and Regulations3. We used reasonable care in identifying and interpreting applicable codes and regulations. These codes

and regulations are subject to various, and possibly contradictory, interpretations. Compliance withcodes and regulations by other parties is beyond our control.

Additional Services4. We recommend that we be retained to provide services during any future: investigations, design,

implementation activities, construction and/or property development/redevelopment. This will allowus the opportunity to: 1) observe conditions and compliance with our recommendations and opinions;2) allow for changes in the event that conditions are other than anticipated; 3) provide modifications toour recommendations; and 4) assess the consequences of changes in technologies and/or regulations.

Reliance on Information from Others5. We relied upon information made available by other parties. We did not attempt to independently verify

the accuracy or completeness of that information. Inconsistencies in this information which we havenoted, if any, are discussed in the Report.

Use of Report6. This report has been prepared for the exclusive use of Watermark Environmental, Inc. of Lowell,

Massachusetts for specific application to the proposed pavement rehabilitation outside Building No.A-63 in Newport, Rhode Island, in accordance with generally accepted soil and foundationengineering practices. No warranty, express or implied, is made.

7. This engineering report has been prepared for this project by GZA. This report is for design purposesonly and is not sufficient to prepare an accurate bid. Contractors requesting a copy of the report maysecure it with the understanding that its scope is limited to design considerations only.

APPENDIX B

BORING LOGS

S-1

S-2

S-3

24

12

11

24

14

24

1

2

S-1: Very dense, black, fine to coarse SAND, some Silt,some Gravel, dry.

S-2: Very dense, gray, fine to coarse SAND, some Gravel,little Silt, dry [Gravel component largely consists ofcompletely weathered, Shale-like Rock.]S-3: Dense, brown, SILT and fine to medium SAND, traceGravel, dry.

Bottom of boring at 6 feet.

4'

6'

0-2

2-4

4-620.0'

18.0'

19 29

37 33

41 33

50/2"

10 16

20 20

66

R

36

FILL

SILTY SAND

1. Ground surface elevations were estimated from contours shown on an undated existing conditions plan titled "Replace Parking Lot, Building A-63", provided by WatermarkEnvironmental, Inc.

2. Boring backfilled with cuttings upon completion.

Auger/Casing Type:

Water Depth

Other:Sample

N/A

HSA7-5/8"/4-1/4"

Hammer Weight (lb.):

Hammer Fall (in.):

Other:

Type of Rig: Truck Mounted

5/7/2014 - 5/7/2014

Safety Sliding

NAVD 88

24

DateSampler Type: Groundwater Depth (ft.)Split Spoon

2"140 lb24"

Rig Model:

Boring Location:

Logged By:

Encountered

CasingI.D/O.D.(in): I.D./O.D. (in.): Stab. Time

Laurie Miller

New Hampshire BoringDrilling Co.:

Final Boring Depth (ft.):

See Plan

6

H. Datum:

Date Start - Finish:

Not

Time

N/A

Foreman: Ernie NadeauGround Surface Elev. (ft.):

V. Datum:

Sampler Hmr Wt (lb):

Sampler Hmr Fall (in):

Drilling Method:

Diedrich D90

Hollow Stem Auger

RI State Plan NAD83

Boring No.:GZ-1

No.

BORING NO.: GZ-1SHEET: 1 of 1PROJECT NO: 18.0171977.00REVIEWED BY: DJS

RE

MA

RK

S

Engineers and Scientists

Rec.(in)

Pen.(in) R

emar

k

TEST BORING LOG

FieldTestData

Sample Description and Identification(Modified Burmister Procedure)

See Log Key for explanation of sample description and identification procedures. Stratification lines represent approximate boundaries between soil andbedrock types. Actual transitions may be gradual. Water level readings have been made at the times and under the conditions stated. Fluctuations ofgroundwater may occur due to other factors than those present at the times the measurements were made.

CasingBlows/CoreRate

Dep

th(f

t.)Depth

(ft)

5

10

15

20

25

30

18.0

1719

77.0

0 W

AT

ER

MA

RK

EN

VIR

ON

ME

NT

AL-

BLD

G 6

3 N

AV

AL

ST

AT

ION

NE

WP

OR

T, R

I.GP

J; S

TR

AT

UM

ON

LY 2

PG

; 5/2

1/2

014

Depth(ft.) E

lev.

(ft.

)

Blows(per 6 in.)

SPTValue

Building A63Newport Naval StationNewport, Rhode Island

GZAGeoEnvironmental, Inc.

StratumDescription

S-1

S-2

S-3

S-4

S-5

9

18

14

24

13

24

24

24

24

24

1

2

S-1: Dense, black to brown, fine to coarse SAND, someGravel, some Silt, dry.

S-2: Top 15": Dense, black, fine to coarse SAND, someSilt, little Gravel, dry.Bottom 3": Gray, completely weathered Shale-like Gravel..S-3: Very dense, gray, fine to coarse SAND and GRAVEL,little Silt [Gravel consists of completely weathered Shale.]Wet in bottom 1".S-4: Medium dense, gray/brown, SILT and fine to coarseSAND, trace Gravel, wet.S-5: Medium dense, gray/brown, fine to mediumSAND and SILT, trace Gravel, wet.


0.1'

6'

10'

0-2

2-4

4-6

6-8

8-10

23.9'

18.0'

14.0'

19 18

13 17

7 8

31 39

5 50

24 12

5 13

15 14

3 10

9 9

31

39

74

28

19

ASPHALT

FILL

SILTY SAND


2. Boring backfilled with cuttings and patched at the surface with asphalt.

Auger/Casing Type:

Water Depth

Other:Sample

N/A

HSA7-5/8"/4-1/4"


Hammer Fall (in.):

Other:


5/7/2014 - 5/7/2014

Safety Sliding

NAVD 88

24


2"140 lb24"

Rig Model:

Boring Location:

Logged By:

9.5'±11:56


Laurie Miller



See Plan

10

H. Datum:

0


5/7/14

Time

N/A


V. Datum:



Drilling Method:

HSA @ 8'

Diedrich D90

Hollow Stem Auger

RI State Plan NAD83

Boring No.:GZ-2

No.


RE

MA

RK

S


Rec.(in)

Pen.(in) R

emar

k

TEST BORING LOG

FieldTestData




Dep

th(f

t.)Depth

(ft)

5

10

15

20

25

30

18.0

1719

77.0

0 W

AT

ER

MA

RK

EN

VIR

ON

ME

NT

AL-

BLD

G 6

3 N

AV

AL

ST

AT

ION

NE

WP

OR

T, R

I.GP

J; S

TR

AT

UM

ON

LY 2

PG

; 5/2

1/2

014

Depth(ft.) E

lev.

(ft.

)

Blows(per 6 in.)

SPTValue



StratumDescription

S-1

S-2

S-3

23

16

19

24

24

24

1

2

S-1: Top 5": Brown, fine to coarse SAND, little Gravel, littleSilt, dry.Bottom 18": Gray, fine to coarse SAND, some Gravel,some Silt, trace Brick, dry.S-2: Dense, gray/brown, fine to coarse SAND, someGravel, some Silt, wet.S-3: Medium dense, brown/gray, fine to coarse SAND andSILT, trace Shale-like Gravel, moist.


0.1'

4'

6'

0-2

2-4

4-6

24.4'

20.5'

18.5'

12 20

17 22

6 16

22 18

7 11

11 9

37

38

22

ASPHALT

FILL

SILTY SAND



Auger/Casing Type:

Water Depth

Other:Sample

N/A

HSA7-5/8"/4-1/4"


Hammer Fall (in.):

Other:


5/7/2014 - 5/7/2014

Safety Sliding

NAVD 88

24.5


2"140 lb24"

Rig Model:

Boring Location:

Logged By:

Encountered


Laurie Miller



See Plan

6

H. Datum:


Not

Time

N/A


V. Datum:



Drilling Method:

Diedrich D90

Hollow Stem Auger

RI State Plan NAD83

Boring No.:GZ-3

No.


RE

MA

RK

S


Rec.(in)

Pen.(in) R

emar

k

TEST BORING LOG

FieldTestData




Dep

th(f

t.)Depth

(ft)

5

10

15

20

25

30

18.0

1719

77.0

0 W

AT

ER

MA

RK

EN

VIR

ON

ME

NT

AL-

BLD

G 6

3 N

AV

AL

ST

AT

ION

NE

WP

OR

T, R

I.GP

J; S

TR

AT

UM

ON

LY 2

PG

; 5/2

1/2

014

Depth(ft.) E

lev.

(ft.

)

Blows(per 6 in.)

SPTValue



StratumDescription

S-1

S-2

S-3

23

20

23

24

24

24

1

2

S-1: Loose, brown/gray, fine to coarse SAND and SILT,trace Gravel, trace Wood, moist.

S-2: Medium dense, brown/gray, fine to coarse SAND andSILT, trace Gravel, dry.

S-3: Medium dense, brown/gray, SILT and fine to coarseSAND, moist 9" from top (4" seam of completelyweathered Shale-like Gravel)


0.2'

6'

0-2

2-4

4-6

25.8'

20.0'

5 3

5 12

3 6

14 15

8 12

8 7

8

20

20

ASPHALT

FILL



Auger/Casing Type:

Water Depth

Other:Sample

N/A

HSA7-5/8"/4-1/4"


Hammer Fall (in.):

Other:


5/7/2014 - 5/7/2014

Safety Sliding

NAVD 88

26


2"140 lb24"

Rig Model:

Boring Location:

Logged By:

Encountered


Laurie Miller



See Plan

6

H. Datum:


Not

Time

N/A


V. Datum:



Drilling Method:

Diedrich D90

Hollow Stem Auger

RI State Plan NAD83

Boring No.:GZ-4

No.


RE

MA

RK

S


Rec.(in)

Pen.(in) R

emar

k

TEST BORING LOG

FieldTestData




Dep

th(f

t.)Depth

(ft)

5

10

15

20

25

30

18.0

1719

77.0

0 W

AT

ER

MA

RK

EN

VIR

ON

ME

NT

AL-

BLD

G 6

3 N

AV

AL

ST

AT

ION

NE

WP

OR

T, R

I.GP

J; S

TR

AT

UM

ON

LY 2

PG

; 5/2

1/2

014

Depth(ft.) E

lev.

(ft.

)

Blows(per 6 in.)

SPTValue



StratumDescription

S-1

S-2

S-3

S-4

S-5

24

11

14

18

19

24

24

24

24

24

1

2

S-1: Top 13": Brown, fine to coarse SAND, trace Silt, dry.Bottom 11": Gray/brown, fine to coarse SAND and SILT,little Gravel, dry.S-2: Gray/brown, fine to coarse SAND and SILT, traceGravel, dry.

S-3: Medium dense, gray, fine to coarse SAND, little Silt,wet.

S-4: Loose, gray, fine to coarse SAND, little Silt, traceGravel, wet.

S-5: Dense, brown/gray, fine to coarse SAND, some Silt,some Gravel, wet.


0.1'1'

10'

0-2

2-4

4-6

6-8

8-10

23.9'23.0'

14.0'

9 11

9 11

14 15

15 13

4 10

13 14

4 5

4 6

12 16

15 19

20

30

23

9

31

ASPHALTFILL

SILTY SAND



Auger/Casing Type:

Water Depth

Other:Sample

N/A

HSA7-5/8"/4-1/4"


Hammer Fall (in.):

Other:


5/7/2014 - 5/7/2014

Automatic Hammer

NAVD 88

24


2"140 lb24"

Rig Model:

Boring Location:

Logged By:

6.5'±15:00


Laurie Miller



See Plan

10

H. Datum:

5 min


5/7/14

Time

N/A


V. Datum:



Drilling Method:

HSA @ 8'

Diedrich D90

Hollow Stem Auger

RI State Plan NAD83

Boring No.:GZ-5

No.


RE

MA

RK

S


Rec.(in)

Pen.(in) R

emar

k

TEST BORING LOG

FieldTestData




Dep

th(f

t.)Depth

(ft)

5

10

15

20

25

30

18.0

1719

77.0

0 W

AT

ER

MA

RK

EN

VIR

ON

ME

NT

AL-

BLD

G 6

3 N

AV

AL

ST

AT

ION

NE

WP

OR

T, R

I.GP

J; S

TR

AT

UM

ON

LY 2

PG

; 5/2

1/2

014

Depth(ft.) E

lev.

(ft.

)

Blows(per 6 in.)

SPTValue



StratumDescription

S-1

S-2

S-3

24

16

18

24

24

24

1

2

S-1: Top 12": Brown, fine to coarse SAND, some fineGravel, little Silt.Middle 6": Dark gray, SILT, some Sand, trace Gravel.Bottom 6": Brown/gray, fine to coarse SAND, little Silt, littleGravel, dry.S-2: Top 4": Brown, fine to coarse SAND, little Silt.Middle 5": Black weathered Shale-like Gravel.Bottom 7": Brown/gray, fine to medium SAND and SILT,dry.S-3: Medium dense, brown/gray, fine to medium SANDand SILT, moist.


0.2'

3.5'

6'

0-2

2-4

4-6

23.8'

20.5'

18.0'

8 12

13 13

12 14

12 14

14 13

11 8

25

26

24

ASPHALT

FILL

SILTY SAND



Auger/Casing Type:

Water Depth

Other:Sample

N/A

HSA7-5/8"/4-1/4"


Hammer Fall (in.):

Other:


5/7/2014 - 5/7/2014

Automatic Hammer

NAVD 88

24


2"140 lb24"

Rig Model:

Boring Location:

Logged By:

5.5'±16:05


Laurie Miller



See Plan

6

H. Datum:

5 min


5/7/14

Time

N/A


V. Datum:



Drilling Method:

HSA @ 4'

Diedrich D90

Hollow Stem Auger

RI State Plan NAD83

Boring No.:GZ-6

No.


RE

MA

RK

S


Rec.(in)

Pen.(in) R

emar

k

TEST BORING LOG

FieldTestData




Dep

th(f

t.)Depth

(ft)

5

10

15

20

25

30

18.0

1719

77.0

0 W

AT

ER

MA

RK

EN

VIR

ON

ME

NT

AL-

BLD

G 6

3 N

AV

AL

ST

AT

ION

NE

WP

OR

T, R

I.GP

J; S

TR

AT

UM

ON

LY 2

PG

; 5/2

1/2

014

Depth(ft.) E

lev.

(ft.

)

Blows(per 6 in.)

SPTValue



StratumDescription

S-1

S-2

S-3

20

6

13

24

24

24

1

2

S-1: Dense, gray, fine to coarse SAND, some Gravel,some Silt, dry.

S-2: Very dense, gray, fine to coarse SAND, some Silt,Gravel in tip, dry.

S-3: Medium dense, brown/gray, fine to medium SANDand SILT, moist.


0.1'

4'

6'

0-2

2-4

4-6

19.9'

16.0'

14.0'

20 23

19 16

10 7

60 48

10 12

14 18

42

67

26

ASPHALT

FILL

SILTY SAND



Auger/Casing Type:

Water Depth

Other:Sample

N/A

HSA7-5/8"/4-1/4"


Hammer Fall (in.):

Other:


5/7/2014 - 5/7/2014

Automatic Hammer

NAVD 88

20


2"140 lb24"

Rig Model:

Boring Location:

Logged By:

Encountered


Laurie Miller



See Plan

6

H. Datum:


Not

Time

N/A


V. Datum:



Drilling Method:

Diedrich D90

Hollow Stem Auger

RI State Plan NAD83

Boring No.:GZ-7

No.


RE

MA

RK

S


Rec.(in)

Pen.(in) R

emar

k

TEST BORING LOG

FieldTestData




Dep

th(f

t.)Depth

(ft)

5

10

15

20

25

30

18.0

1719

77.0

0 W

AT

ER

MA

RK

EN

VIR

ON

ME

NT

AL-

BLD

G 6

3 N

AV

AL

ST

AT

ION

NE

WP

OR

T, R

I.GP

J; S

TR

AT

UM

ON

LY 2

PG

; 5/2

1/2

014

Depth(ft.) E

lev.

(ft.

)

Blows(per 6 in.)

SPTValue



StratumDescription

APPENDIX C

GEOTECHNICAL LABORATORY RESULTS

LABORATORY TESTING DATA SHEET

Project Name Building A63 - Naval Station Newport Location Newport, RI Reviewed ByProject No. 01.0171977.00 Assigned By Laurie Miller

Project Manager Derek Schipper Report Date Date Reviewed 5/14/2014

Boring/Test Pit No.

SampleNo. Depth ft. Lab

No.

WaterContent

%

LL%

PL%

Sieve-200

%

Hyd-2µ%

ORG %

Gs

Dry unit wt.

pcf

Torvane or Type

Test

sc

psfFailure Criteria

s1 - s3

psfStrain

%

Laboratory Logand

Soil Description

GZ-2 S-4 6-8 1 47.1Brown SILT and f-c SAND, trace

Gravel

GZ-5 S-5 8-10 2 28.9Gray-brown f-c SAND, some Silt,

some f-c Gravel

GZ-6 S-1A 0-1 3 16.3Brown f-c SAND, some fine

Gravel, little Silt

GZ-3 S-2 2-4 4 24.6Gray f-c SAND, some f-c Gravel,

some Silt

195 Frances AvenueCranston, RI 02910 401-467-6454

Strength TestsIdentification Tests

5/14/2014

ASTM D422

Gravel Sand Fines7.4% 45.6% 47.1%

Lab # Exploration Depth WC LL PL PI1 GZ-2 6-8' Brown SILT and f-c SAND, trace Gravel

Sieve Size % Passing

¾" 100.0

½" 98.3

#4 92.6

#10 86.2

#20 78.2

#40 70.3

#60 63.3 Tested by: 195 Frances Ave., Cranston, RI 02910 #100 56.2 Reviewed by: 401-467-6454 #200 47.1

GZA File # 01.0171977.00GG Date: 5/14/14

MBP Date: 5/14/14

Sample DescriptionS-4

CTS-74-14-0003Building A63 - Naval Station Newport

Newport, RI

3" 2" 1" 3/4" 1/2" #4 #10 #20 #40 #60 #100 #200

0

10

20

30

40

50

60

70

80

90

100

0.0010.010.1110100

Per

cent

Fin

er b

y W

eigh

t

Grain Size (mm)

U.S. STANDARD SIEVE AND HYDROMETER

SAND

CLAY

GRAVEL

Fine Coarse Coarse Fine Medium

SILT

ASTM D422


Lab # Exploration Depth WC LL PL PI2 GZ-5 8-10' Gray-brown f-c SAND, some Silt, some f-c Gravel


¾" 95.3

½" 87.3

#4 73.6

#10 64.5

#20 55.0

#40 47.3


GZA File # 01.0171977.00GG Date: 5/14/14

MBP Date: 5/14/14



Newport, RI

3" 2" 1" 3/4" 1/2" #4 #10 #20 #40 #60 #100 #200

0

10

20

30

40

50

60

70

80

90

100

0.0010.010.1110100

Per

cent

Fin

er b

y W

eigh

t

Grain Size (mm)


SAND

CLAY

GRAVEL


SILT

ASTM D422


Lab # Exploration Depth WC LL PL PI3 GZ-6 0-1' Brown f-c SAND, some fine Gravel, little Silt


¾" 100.0

½" 92.8

#4 79.4

#10 71.4

#20 61.2

#40 45.6


GZA File # 01.0171977.00GG Date: 5/14/14

MBP Date: 5/14/14

Sample DescriptionS-1A


Newport, RI

3" 2" 1" 3/4" 1/2" #4 #10 #20 #40 #60 #100 #200

0

10

20

30

40

50

60

70

80

90

100

0.0010.010.1110100

Per

cent

Fin

er b

y W

eigh

t

Grain Size (mm)


SAND

CLAY

GRAVEL


SILT

ASTM D422


Lab # Exploration Depth WC LL PL PI4 GZ-3 2-4' Gray f-c SAND, some f-c Gravel, some Silt


¾" 74.5

½" 73.1

#4 67.3

#10 60.7

#20 53.3

#40 44.8


GZA File # 01.0171977.00GG Date: 5/14/14

MBP Date: 5/14/14



Newport, RI

3" 2" 1" 3/4" 1/2" #4 #10 #20 #40 #60 #100 #200

0

10

20

30

40

50

60

70

80

90

100

0.0010.010.1110100

Per

cent

Fin

er b

y W

eigh

t

Grain Size (mm)


SAND

CLAY

GRAVEL


SILT

GZA Engineers and

GeoEnvironmental, Inc. Scientists

Copyright 2014 GZA GeoEnvironmental, Inc.

372 Merrimac Street

Newburyport, MA 01950

Office: 781-278-4800

Fax: 978-465-1428

www.gza.com

October 9, 2014

GZA File No. 18.0171977.00

Robert B. Blanchette, Jr., P.E.

Watermark Environmental, Inc.

175 Cabot Street

Lowell, Massachusetts 01854

Re: Revised Pavement Cross-Section

Building A-63 Parking Lot Replacement

Newport Naval Station

Newport, Rhode Island

Dear Mr. Blanchette:

Per our recent discussions, GZA GeoEnvironmental, Inc. (GZA) has reevaluated the proposed parking

lot cross-section for Building A-63 at the Newport Naval Station in Newport, Rhode Island. This letter

is subject to the Limitations set forth in Appendix A and the Terms and Conditions of our agreement.

INITIAL RECOMMENDED PAVEMENT CROSS-SECTION

On September 11, 2014, GZA issued a report providing recommended pavement cross-sections for

the proposed parking lot renovations. Our recommendations were generally developed utilizing the

criteria set forth in “Unified Facilities Criteria, Pavement Design for Roads, Streets, Walks, and

Open Storage Areas, UFC 3-250-01FA”, dated January 16, 2004 (UFC). Our September 11, 2014

pavement cross-section recommendations are presented below:

In general, design of the pavement cross-section per the UFC is governed by frost considerations,

proposed vehicle use and the subgrade soils. GZA provided pavement cross-sections for passenger

vehicles and for trucks as it was our understanding at the time that some areas would only be

accessible to passenger vehicles while other areas would be traversed by trucks with H-20 loading.

Our recommendations assumed F3 subgrade soils per Table 18-2 of the UFC. F3 subgrade soils are

defined as the following Unified Soil Classification System soil types: GM – silty gravel and GC –

clayey gravel. Table 18-2 further defines F3 soils as having a percentage finer than retained by a

0.02 mm sieve opening by weight over 20 percent. We assumed F3 subgrade soils based on data

from a limited amount of subsurface explorations.


Minimum Thickness

Car Parking

(Category I)

Truck Loading

(Category III)

Finish Course 1.5 inches 1.5 inches

Binder Course 2 inches 2.5 inches

Sand-Gravel Base Course 10 inches 14 inches

http://www.gza.com/

Watermark Environmental, Inc. October 9, 2014 GZA No. 171977.00 Page 2

The pavement recommendations in the table above include a 1.5-inch-thick surface/wearing course

of pavement. However, a top course is not specifically required per UFC 3-250-01FA. According

to Table 6-1, the required pavement thickness for Design Index 1 and 3 are 2 inches and 2.5 inches,

respectively.

Based on the Team’s review of the RFP requirements and the Navy’s comments to Final Design,

the entire parking lot area shall accommodate H-20 truck loading. In addition, it is Watermark’s

intention to perform full-depth pavement reclamation of the existing pavement into the underlying

fill in order to provide a pavement base course that will meet the recommended gradation criteria

set forth in the UFC.

SUPPLEMENTAL SUBSURFACE EXPLORATIONS

Watermark performed additional subsurface explorations to supplement the previous subsurface

explorations to further evaluate: 1) subgrade soils at the Site; and, 2) whether a base course fill

generated from full depth reclamation of the existing pavement and underlying fill would meet the

recommended gradation criteria set forth in the UFC.

On September 19, 2014, Watermark Environmental performed fourteen test holes (TH-1 through

TH-15, TH-6 was not performed) at proposed pavement locations to supplement the six test

borings (GZ-1 through GZ-6) performed during the initial design phase of the project.

The test holes consisted of shallow hand excavations. Prior to excavating, the existing pavement

was saw cut and removed. The excavations were carried to depths of 9 to 14 inches below the top

of pavement. Watermark representatives performed the excavations, collected soil samples and

logged the explorations. The information obtained at the test hole locations by Watermark is

summarized below:


Test

Hole

No.

Pavement

Thickness

(inches)

Total Depth

of Test Hole

(inches)

1 4 10

2 3 9

3 3 9

4 3 9

5 3 9

7 0 9

8 0 9

9 3 9

10 3 9

11 3 9

12 2 12

13 2 14

14 2 9

15 2 12

The thickness of the existing pavement ranged from 2 to 4 inches. There was no existing pavement

at TH-7 and TH-8 performed north of Building A63. The average pavement thickness (including

the areas with no pavement) was 2.4 inches.

Soil samples from test holes TH-2, TH-4, TH-10 and TH-12, which were considered to be

representative of typical conditions, were submitted to Thielsch Engineering of Cranston, Rhode

Island for gradation analyses. The results are provided as Appendix B. Based on the laboratory test

results, the volume of soil retained by a No. 200 Sieve by weight ranged from 7.9 to 14.8 percent.

REVISED PAVEMENT CROSS-SECTION

Using the additional subsurface data, GZA has reevaluated the proposed pavement cross section for

the Site. We utilized the supplemental subsurface explorations to evaluate the subgrade soils and a

base course generated by full-depth reclamation of the existing pavement and underlying fill. The

pavement cross section was developed using the criteria set forth in the UFC.

Traffic Evaluation and Design Index

Based on our review of the RFP requirement to meet H-20 loading, Traffic Category III, as

defined in Section 3-2 of the UFC, is appropriate for this site. Using Table 3-1, we selected a

Design Index of 3 for Category III traffic.

Existing Subgrade Soils

The supplemental explorations provide more comprehensive coverage across the proposed

parking lot than the initial six test borings. After evaluating the existing fill in the upper two feet

below the existing pavement, it appears a subgrade soil designation of F2 (per table 18-1) is more

appropriate for this site. Table 18-2 defines F2 gravelly soils as having a percentage of 10 to 20

percent finer than 0.02 mm opening by weight. Although hydrometer testing was not performed on


the samples submitted to the lab1, a projected gradation curve indicates the percentage of soil finer

than the 0.02 mm opening by weight in the samples would be less than 20 percent.

Revised Pavement Cross-Section

We evaluated the total pavement cross-section utilizing the “Reduced Subgrade Strength

Method” from Section 18-7 of the UFC. For F2 subgrade soils, a Frost-area soil support index of

6.5 was selected from Table 18-3. Using a support index of 6.5 along the X-axis of Figure 8-1 and

a Design Index of 3, a total thickness (pavement and base course) of 12 inches is required.

According to Table 6-1, the minimum pavement thickness for Design Index 3 is 2.5 inches.

In order to provide a top/wearing course for the parking lot, we recommend 3 inches of pavement

be provided. In order to provide a total cross-section of 12 inches, we recommend nine inches of

base course be provided below the pavement. Thus, the revised pavement cross-section per the

UFC is as follows:

1 Table 18-1 provides gradation guidance for a percentage of soil finer than 0.02 mm by weight. A

hydrometer test is necessary to measure to this particle size. The US No. 200 sieve used in our gradation

analyses corresponds to a 0.074 mm grain size. Thus, the percent of soil finer than 0.02 will be less than the

percent finer than the US No. 200 sieve.

Pavement Cross-Section Per UFC 3-250-01FA

Category III

Minimum Thickness

Finish Course 1.0 inches

Binder Course 2.0 inches

Base Course 9 inches


Proposed Pavement Base Course

Based on the gradation testing performed on samples obtained to a depth of about 12

inches in the subsurface explorations performed to date, the amount of soil retained by a No. 200

sieve (by weight) ranged from 7.9 to 16.3 percent with an average of 13 percent.

GZA estimated the gradation of a base course fill generated by full depth reclamation of

the existing pavement and underlying fill to a depth of 9 inches below top of existing pavement.

Based on the gradation analyses performed on samples obtained from 12 inches below the existing

pavement, the average distribution of soil particles is as follows:

Gravel – 33%

Sand – 54%

Fines2 – 13%

Watermark proposes to perform full-depth reclamation of the existing pavement into the

underlying soils to provide a pavement base course. Assuming 2.4 inches of existing pavement is

blended with 6.6 inches underlying fill, we estimate the gradation of the top 9 inches of fill

(proposed base course) will be approximately:

Gravel – 43%

Sand – 46%

Fines – 11%

This estimate assumes that the reclaimed pavement will be pulverized to 70 percent gravel,

25 percent sand and 5 percent silt.

Section 18-3 of the UFC indicates the first four soil groups of Table 18-2 are “generally

suitable for base course”. We estimate that the blended soil of reclaimed asphalt and underlying

fill will consist of an S1 or S2 soil as defined in Table 18-2. We note S1 and S2 soils have 3 to 6

percent finer than a 0.02 mm opening by weight. Based on a projected gradation curve for the

blended base course fill, we anticipate that the blended base course will meet this criterion. Refer

to the attached gradation curve for the proposed blended base course fill in Appendix C for details.

During construction, it will be more practical and efficient to perform gradation analyses to

a minimum particle size retained by a No. 200 sieve. Analyzing soil samples to the gradation

requirement of Table 18-2 will require hydrometer testing on the samples. In our opinion,

providing a base course with less than 10 percent passing by a No. 200 sieve will meet or exceed

the gradation criteria of 3 to 6 percent finer than 0.02 mm opening by weight.

CONSTRUCTION RECOMMENDATIONS

Watermark proposes to reclaim the existing asphalt and blend the pulverized material into the

underlying fill to a depth suitable to provide a cross section that satisfies the criteria of the UFC.

2 Fines consist of silt and clay sized particles or soils retained by a No. 200 Sieve which has an opening size

of 0.074mm.


GZA recommends that the base course be sampled at a frequency of about every 200 cubic yards

for gradation analyses to verify the blended base course meets the recommended criterion of 10

percent or less passing a No. 200 sieve.

If the gradation criterion is not met, Watermark should be prepared to modify the base course to

lower the overall percentage of fines in the fill.

We trust that the information presented herein addresses your needs related to the revised pavement

design. GZA should be present at the Site during construction to observe reclamation of the

pavement and fill, observe subgrade soils, sample and analyze the base course after blending, and

observe placement and compaction of the base course prior to paving.

We have enjoyed working with you on this project and would look forward to our continued

involvement. Please call Derek Schipper at 781-278-5792 or Anders Bjarngard at 781-278-4802

should you have any questions.

Very truly yours,

GZA GEOENVIRONMENTAL, INC.

Derek J. Schipper, P.E. Bruce Fairless, P.E.

Senior Project Manager Consultant/Reviewer

Anders B. Bjarngard, P.E.

Principal

Attachments: Appendix A – Limitations

Appendix B – Geotechnical Laboratory Results

Appendix C – Estimated Gradation Curve for Blended Base Course

\\GZANEWBURYPT\Jobs\171900's\18.0171977.00\Revised Pavement Cross Section\171977-00-l01.docx

APPENDIX A

LIMITATIONS

LIMITATIONS

Subsurface Conditions

1. The generalized soil profile(s) provided in our Report and on our subsurface exploration logs are

intended only to convey trends in subsurface conditions. The boundaries between strata are approximate

and idealized, and were based on our assessment of subsurface conditions. The composition of strata,

and the transitions between strata, may be more variable and more complex than indicated. For more

specific information on soil conditions at a specific location refer to the exploration logs.

2. Water level readings have been made in explorations at the specified times and under the stated

conditions. These data have been reviewed and interpretations have been made in this Report.

However, fluctuations in the level of the groundwater occur due to temporal or spatial variations in areal

recharge rates, soil heterogeneities, the presence of subsurface utilities, and/or natural or artificially

induced perturbations. The observed water table may be other than indicated in the Report

Compliance with Codes and Regulations

3. We used reasonable care in identifying and interpreting applicable codes and regulations. These codes

and regulations are subject to various, and possibly contradictory, interpretations. Compliance with

codes and regulations by other parties is beyond our control.

Additional Services

4. We recommend that we be retained to provide services during any future: investigations, design,

implementation activities, construction and/or property development/redevelopment. This will allow

us the opportunity to: 1) observe conditions and compliance with our recommendations and opinions;

2) allow for changes in the event that conditions are other than anticipated; 3) provide modifications to

our recommendations; and 4) assess the consequences of changes in technologies and/or regulations.

Reliance on Information from Others

5. We relied upon information made available by other parties. We did not attempt to independently verify

the accuracy or completeness of that information. Inconsistencies in this information which we have

noted, if any, are discussed in the Report.

Use of Report

6. This report has been prepared for the exclusive use of Watermark Environmental, Inc. of Lowell,

Massachusetts for specific application to the proposed pavement rehabilitation outside Building No.

A-63 in Newport, Rhode Island, in accordance with generally accepted soil and foundation

engineering practices. No warranty, express or implied, is made.

7. This engineering report has been prepared for this project by GZA. This report is for design purposes

only and is not sufficient to prepare an accurate bid. Contractors requesting a copy of the report may

secure it with the understanding that its scope is limited to design considerations only.

APPENDIX B

GEOTECHNICAL LABORATORY RESULTS

ASTM D422


Lab # Exploration Depth WC LL PL PI

5 TH-2 0-1' Brown f-c SAND and f-c GRAVEL, trace Silt


¾" 83.9

½" 74.4

#4 54.7

#10 42.7

#20 31.4

#40 22.5


GZA File # 01.0171977.00LM/MS Date: 9/25/14MBP Date: 9/25/14

Sample Description

S-1

CTS-74-14-0003Building A-63 Parking Lot

Newport, RI

3" 2" 1" 3/4" 1/2" #4 #10 #20 #40 #60 #100 #200

0

10

20

30

40

50

60

70

80

90

100

0.0010.010.1110100

Per

cent

Fin

er b

y W

eigh

t

Grain Size (mm)


SAND

CLAY

GRAVEL


SILT

ASTM D422



6 TH-4 0-1' Gray-brown f-c SAND, some f-c Gravel, little Silt


¾" 87.6

½" 82.2

#4 72.9

#10 66.6

#20 58.0

#40 43.6



Sample Description

S-1


Newport, RI

3" 2" 1" 3/4" 1/2" #4 #10 #20 #40 #60 #100 #200

0

10

20

30

40

50

60

70

80

90

100

0.0010.010.1110100

Per

cent

Fin

er b

y W

eigh

t

Grain Size (mm)


SAND

CLAY

GRAVEL


SILT

ASTM D422



7 TH-10 0-1' Gray-brown f-c SAND, some f-c Gravel, little Silt


¾" 91.0

½" 83.8

#4 72.2

#10 64.0

#20 54.0

#40 40.0



Sample Description

S-1


Newport, RI

3" 2" 1" 3/4" 1/2" #4 #10 #20 #40 #60 #100 #200

0

10

20

30

40

50

60

70

80

90

100

0.0010.010.1110100

Per

cent

Fin

er b

y W

eigh

t

Grain Size (mm)


SAND

CLAY

GRAVEL


SILT

ASTM D422



8 TH-12 0-1' Dark gray f-c GRAVEL and f-c SAND, little Silt


¾" 78.9

½" 71.5

#4 56.1

#10 47.2

#20 39.1

#40 29.6



Sample Description

S-1


Newport, RI

3" 2" 1" 3/4" 1/2" #4 #10 #20 #40 #60 #100 #200

0

10

20

30

40

50

60

70

80

90

100

0.0010.010.1110100

Per

cent

Fin

er b

y W

eigh

t

Grain Size (mm)


SAND

CLAY

GRAVEL


SILT

APPENDIX C

ESTIMATED GRADATION CURVE FOR BLENDED BASE COURSE

Project: Building A63 Pavement

Job. No.: 171977.00GRADATION TEST Date: 10/8/2014

Calculated by:

Blended Base Course

0

10

20

30

40

50

60

70

80

90

100

0.0010.010.1110100

PE

RC

EN

TF

INE

RB

YW

EIG

HT

GRAIN SIZE IN MILLIMETERS

GZA GeoEnvironmental, Inc.

2in

.

1in

.

3/4

in.

1/2

in.

No.

4

No.

10

No.

20

No.

40

No.

100

No.

20

0

U.S. STANDARD SIEVE SIZE

GRAVEL

COARSE FINE

SAND

COARSE MEDIUM FINEFINES

0.02 mm opening

Projected Gradation Curve

Watermark

APPENDIX D

Retaining Wall Inspection Report

Dankers Structural Consulting LLC

Dankers Structural Consulting, LLC 16 Kenney Road

Medfield, MA 02052

phone (508) 359-4075

fax (508) 242-9644

1

June 5, 2014

Mr. Robert B. Blanchette, Jr.

Watermark Environmental, Inc.

175 Cabot Street Lowell, MA 01854

Reference: NNaavvaall SSttaattiioonn NNeewwppoorrtt

Parking Lot Site Wall Inspection Newport, RI DSC Project No. 14032

Watermark Project No. 10408-07-D0010 Dear Robert, On May 20, 2014 we visited the above mentioned site to investigate the condition of the existing site wall in the parking lot of Building A63. The wall is a curved concrete retaining wall that varies in height. Near the building the wall retains approximately four feet of soil and tappers down to flush with grade at its far end. The top of the wall extend approximately 12” above the high side grade. Our investigation was conducted to determine the structural condition of the wall. The wall inspection was a visual inspection of the wall without exploratory demolition. Discussion The wall curb is severely cracked and spalling and portions of the top of the wall are crumbling away and exposing the steel reinforcing. The face of the wall has numerous horizontal cracks along the entire length of the wall. The wall face cracks have deposits of white efflorescent material created from water seeping through the wall cracks. Along the curve of the wall a vertical reinforcing bar is exposed due to zero concrete cover during construction. In locations along the wall the concrete is bulging and sounding the concrete reveals that the surface is delaminating. Conclusions & Recommendations In general the top of the wall and surface is in poor condition. The wall is vertically plumb and retains soil but is obviously deteriorating. Our recommendation is that the loose concrete along the top wall curb and vertical surface be

Dankers Structural Consulting LLC

Dankers Structural Consulting, LLC 16 Kenney Road

Medfield, MA 02052

phone (508) 359-4075

fax (508) 242-9644

2

removed and replaced. Large cracks should be routed out and repaired with an injected repair adhesive suitable for exterior conditions. The back of the wall should also be exposed and waterproofed and the weep holes cleaned out and backed with a bed of crushed stone wrapped in geotechnical cloth. We can not determine how long these repairs will extend the life of the wall. If you have any questions on this determination, please contact the writer at DSC. We thank you for this opportunity to be of assistance. Very truly yours, Dankers Structural Consulting, LLC Imants Dankers, P.E. Principal

Watermark

APPENDIX E

Storm Water Pollution Prevention Plan

BUILDING A-63 PARKING LOT REPAIRS STORMWATER POLLUTION PREVENTION PLAN

1. OVERVIEW

Pollution prevention techniques must, to the extent practicable, be incorporated into all sites, especially at commercial and light industrial sites, to minimize the potential impact those activities may have on stormwater runoff quality.

2. GENERAL POLLUTION PREVENTION FEATURES

Storm drain marking (e.g., stenciling) to discourage dumping is recommended to be provided at each inlet.

3. SOLID WASTE CONTAINMENT

Proper containment of solid waste will prevent it from entering drainage systems and polluting waterways. At a minimum, apply the following pollution prevention practices:

• Trash and recycling receptacles must be provided with regular collection at all sites;

• Industrial and commercial sites must include regular street sweeping (at least annually) in their maintenance plans.

4. ROADS AND PARKING AREA MANAGEMENT

Impervious areas contribute relatively high concentrations of a wide variety of pollutants, including sediment, nutrients, metals, and volatile organic compounds (VOCs), among other constituents. The discussion below addresses guidance requirements related to road and parking area management.

a. Street and Parking Lot Sweeping Street sweeping helps to remove sediment and debris from paved surfaces, reducing potential pollutant transport to water bodies. Street and parking lot sweeping may also reduce the need for maintenance of pretreatment devices, such as catch basins and water quality inlets.

Street sweeping is a requirement for municipalities pursuant to Phase II of the RIPDES Stormwater Regulations and is also recommended for private entities. Currently, available street sweeping technology is not considered to meet the water quality treatment standard and should not be relied on for TSS removal, but does help as a pretreatment practice.

Debris collected from some streets and parking lots (e.g., LUHPPLs) may be regulated as a hazardous waste. For these cases, debris must be disposed of in accordance with appropriate practice and applicable regulatory standards. Appendix A of the Rules and Regulations for Composting Facilities and Solid Waste Management Facilities, which is entitled “Management of Street Sweepings in Rhode Island,” should be reviewed. For further information, contact the DEM Office of Waste Management.

b. Deicing and Salt Storage

Deicing and sanding operations are often necessary for safety during winter storms; however, the materials used create water quality problems. Use deicing chemicals and sand judiciously. Consider the information in Table 1 when selecting a deicer.

Table 1 Comparison of Environmental Effects of Common Roadway Deicers

Media

Sodium Chloride

(NaCl)

Calcium Chloride

(CaCl2)

Calcium magnesium

acetate (CMA) (CaMgC2H3O2)

Sand (SiO2)

Soils

Cl complexes release heavy metals; Na can breakdown soil structure and reduce permeability

Ca can exchange with heavy metals, increase soil aeration and permeability.

Ca and Mg can exchange with heavy metals.

Gradually will accumulate on soil.

Vegetation

Salt spray/splash can cause leaf scorch and browning or dieback of new plant growth up to 50 feet from road; osmotic stress can result from salt uptake; grass is more tolerant than trees and woody plants.

Little effect.

Accumulates on and around low vegetation.

Groundwater

Mobile Na and Cl ions readily reach groundwater, and concentration levels can temporarily increase in areas of low flow during spring thaws. Ca and Mg can release heavy metals from soil.

No known effect.

Surface Water

Can cause density stratification in small lakes having closed basins, potentially leading to anoxia in lake bottoms; often contain nitrogen, phosphorus, and trace metals as impurities, often in concentrations greater than 5 ppm.

Depletes dissolved oxygen in small lakes and streams when degrading.

Accumulated sand alters stream geometry and habitat

Media

Sodium Chloride

(NaCl)

Calcium Chloride

(CaCl2)

Calcium magnesium

acetate (CMA) (CaMgC2H3O2)

Sand (SiO2)

Aquatic Biota

Little effect in large or flowing bodies at current road salting amounts; small streams that are end points for runoff can receive harmful concentrations of Cl; Cl from NaCl generally not toxic until it reaches levels of 1,000-36,000 ppm.

Can cause oxygen depletion.

Accumulation of particles to stream bottoms degrades habitat, clogs gills.

Source: Adapted from Ohrel, 2000

Sand and deicing chemicals should be stored under cover so as to prevent their

exposure to stormwater; the DEM Groundwater Quality Rules require that deicer materials be covered in areas where the groundwater is classified GAA or GA. Table 2 provide recommendations for the appropriate storage and use of deicers. Storage of these materials may be regulated as an industrial activity. Contact DEM’s Stormwater Program in the Office of Water Resources for further information.

Table 2 Recommendations to Reduce Deicer Impacts

Activity

Recommendation

Storage

x Salt storage piles should be completely covered, ideally by a roof, and at a minimum, by a weighted tarp, and stored on impervious surfaces. The DEM Groundwater Quality Rules require that deicer materials be covered in areas where the groundwater is classified GAA or GA.

x Runoff should be contained in appropriate areas.

x Spills should be cleaned up after loading operations. The material may be directed to a sand pile or returned to salt piles.

x Avoid storage in drinking water supply areas, water supply aquifer recharge areas, and public wellhead protection areas.

Application

x Application rate of deicing materials should be tailored to road conditions (i.e., high versus low volume roads).

x Trucks should be equipped with sensors that automatically control the deicer spread rate.

x Drivers and handlers of salt and other deicers should receive training to improve efficiency, reduce losses, and raise awareness of environmental impacts.

Activity

Recommendation

Other

x Identify ecosystems such as wetlands that may be sensitive to salt.

x Use calcium chloride and CMA in sensitive ecosystem areas.

x To avoid over-application and excessive expense, choose deicing agents that perform most efficiently according to pavement temperature.

x Monitor the deicer market for new products and technology.

Source: Adapted from Ohrel, 2000.

5. Snow Disposal

Improper snow disposal can be a threat to public health and the environment. Disposal should consider site selection, site preparation and maintenance, and emergency snow disposal locations and procedures. Refer to DEM’s Snow Disposal Policy for more details on these topics, which are summarized below.

a. Site Selection

The key to selecting effective snow disposal sites is to locate them adjacent to or on pervious surfaces in upland areas away from water resources and wells. At these locations, snow meltwater can filter in to the soil, leaving behind sand and debris, which can be removed in the springtime. When selecting a site for snow disposal, adhere to the following guidelines:

• Avoid dumping snow into any water body, including rivers,

reservoirs, ponds, lakes, wetlands, bays, or the ocean. In addition to water quality impacts and flooding, snow disposed of in open water can cause navigational hazards when it freezes.

• Do not dump snow within a Wellhead Protection Area (WHPA) of a public water supply well, or within 200 feet of a private well, where road salt may contaminate water supplies.

• Avoid dumping snow in sanitary landfills and gravel pits. Snow meltwater will create more contaminated leachate in landfills posing a greater risk to groundwater. In gravel pits, there is little opportunity for pollutants to be filtered out of the meltwater because groundwater is close to the land surface.

• Avoid disposing of snow on top of storm drain catch basins or in stormwater drainage swales or ditches. Snow combined with sand and debris may block a storm drainage system, causing localized flooding. In addition, a high volume of sand, sediment, and litter released from melting snow may be quickly transported through the drainage system into surface water.

b. Site Selection Procedures

It is important to select appropriate snow disposal sites. The following steps should be taken:

• Estimate how much snow disposal capacity is needed for the season

so that an adequate number of disposal sites can be selected and prepared;

• Identify sites that could potentially be used for snow disposal such as open space (e.g., parking lots or parks);

• Sites located in upland locations that are not likely to impact sensitive environmental resources should be selected first; and

• If more storage space is needed, prioritize the sites with the least environmental impact (using the site selection criteria and the online Environmental Resource Map as a guide).

c. Environmental Resource Map

An interactive map containing a wide variety of GIS data layers of interest to local planning or zoning board members, consultants, or anyone else needing a general mapping of soils, wetlands, land use patterns, regulatory overlay districts and other environmental information can be accessed via the internet at the following address:

http://www.state.ri.us/dem/maps/index.htm.

This interactive map can be used to identify publicly owned open spaces and approximate locations of sensitive environmental resources (locations should be field verified where possible).

d. Site Preparation and Maintenance

In addition to carefully selecting disposal sites before the winter begins, it is important to prepare and maintain these sites to maximize their effectiveness. The following maintenance measures should be undertaken for all snow disposal sites:

• A silt fence or equivalent barrier should be placed securely on the

down- gradient side of the snow disposal site; • To filter pollutants out of the meltwater, a 50-foot vegetative buffer strip

should be maintained during the growth season between the disposal site and adjacent water bodies;

• Debris should be cleared from the site prior to using the site for snow disposal; and

• Debris should be cleared from the site and properly disposed of at the end of the snow season.

e. Emergency Snow Disposal

Under normal winter conditions, storage, and disposal of snow should be done

exclusively in upland areas, not in or adjacent to water bodies or wetlands. However, under extraordinary conditions when upland snow storage options are exhausted, it may be necessary to dispose of snow near or in certain water bodies. The following guidance does not constitute a Clean Water Act permit for such disposal. However, in an emergency situation, DEM is unlikely to pursue an enforcement action for snow disposal by governmental entities into or near certain waters if conducted in accordance with the conditions identified below.

As mentioned earlier, it is important to estimate the amount of snow disposal capacity you will need so that an adequate number of upland disposal sites can be selected and prepared. If despite your planning, designated upland disposal sites have been exhausted, snow may be disposed of at other locations that meet the following criteria.

Under extraordinary conditions, when all upland snow disposal options are exhausted, disposal of snow that is not obviously contaminated with road salt, sand, and other pollutants may be allowed near (within 50 feet of) or in certain water bodies under certain conditions. In these dire situations, notify the DEM – Office of Water Resources, RIPDES Program at 222-4700 (or 222-3070 after normal business hours) before disposing of snow in a water body. If upland disposal is not available, and snow needs to be removed/relocated for safety reasons, then as a last resort waterway may be used in accordance with the following conditions:

• Dispose of snow in open water with adequate flow and mixing to

http://www.state.ri.us/dem/maps/index.htm

prevent ice dams from forming; • Do not dispose of snow in coastal or freshwater wetlands, eelgrass

beds, vegetated shallows, vernal pools, shellfish beds, mudflats, outstanding resource waters, drinking water reservoirs and their tributaries, Wellhead Protection Areas (WHPAs), or other areas designated by the State as being environmentally sensitive;

• In coastal communities, preference should be given to disposal in salt water if it is available;

• Do not dispose of snow where trucks may cause shoreline damage or stream bank damage or erosion; and

• Consult with appropriate municipal officials to ensure that snow disposal in water complies with local ordinances and bylaws.

6. Driveway and Parking Lot Sealants

Driveway and parking lot sealants are a major source of polycyclic aromatic hydrocarbons (PAHs) in our environment. There are two types of sealant: asphalt based and coal-tar based. Both types of sealant contain PAHs, but the coal-tar based sealants have a far higher concentration of PAHs (as much as 70 times higher than asphalt based). As the sealants wear down, small particles of sealant are washed off by stormwater into surface waters. PAHs have been found to be toxic to aquatic life, with bottom dwelling organisms most at risk since PAHs tend to attach to sediment rather than dissolve in water. Also, in recognition of the human health effects of PAHs, DEM has adopted the US EPA water column human health criteria for PAHs in the DEM Water Quality Regulations. Because of the high concentrations of PAHs in coal-tar based sealants, DEM recommends that coal-tar based sealants not be used. For more information, see: US Geological Survey Fact Sheet 2005-3147, “Parking Lot Sealcoat: A Major Source of Polycyclic Aromatic Hydrocarbons (PAHs) in Urban and Suburban Environments.”

7. HAZARDOUS MATERIALS CONTAINMENT

At a minimum, the following practices should be incorporated:

• Adequate indoor storage of hazardous materials as the primary method for preventing problems related to stormwater;

• Diversion through devices such as curbing and berms should be incorporated wherever stormwater has the potential to runoff into hazardous materials storage areas; and

• Secondary containment must be included wherever spills might occur (e.g., fueling and hazardous materials transfer and loading areas). Oil/grit separators and other manufactured treatment devices may temporarily contain certain spills and contaminated stormwater. However, these devices should be used as backup for tighter containment practices.

8. LAWN, GARDEN, AND LANDSCAPE MANAGEMENT

These large areas of managed landscape has the potential to contribute to urban runoff pollution due to over fertilization, overwatering, over application of

pesticides, and direct disposal of lawn clippings, leaves, and trimmings. Also, erosion from bare patches of poorly managed lawn contribute sediment to watercourses, and disposal of lawn clippings in landfills can reduce the capacity of these facilities to handle other types of waste.

The following standards for grounds management must be incorporated into stormwater management plans:

a. Lawn conversion - Grasses require more water and attention than

alternative groundcovers, flowers, shrubs, or trees. Alternatives to turf are especially recommended for problem areas such as lawn edges, frost pockets, shady spots, steep slopes, and soggy areas. Vegetation that is best suited to the local conditions should be selected.

b. Soil building - Grounds operation and maintenance should incorporate

soil evaluation every 1 to 3 years to determine suitability for supporting a lawn, and to determine how to optimize growing conditions. Consider testing soil characteristics such as pH, fertility, compaction, texture, and earthworm content.

c. Grass selection - Grass seed is available in a wide range of cultivated

varieties, so homeowners, landscapers, and grounds managers are able to choose the grass type that grows well in their particular climate, matches site conditions, and is consistent with the property owner's desired level of maintenance. When choosing ground cover, consideration should be given to seasonal variations in rainfall and temperature. Table 3 lists turf grass types and their level of tolerance to drought:

Table 3 Drought Tolerance of Turf grass Types

Turf grass Type

Drought Tolerance

Fine-leaved Fescues Tall Fescue Kentucky Bluegrass Perennial

Ryegrass Bent grasses

High

Low

d. Mowing and thatch management - To prevent insects and weed

problems, property owners should mow high, mow frequently, and keep mower blades sharp. Lawns should not be cut shorter than 2 to 3 inches, because weeds can grow more easily in short grasses. Grass can be cut lower in the spring and fall to stimulate root growth, but not shorter than 1 ½ inches.

e. Fertilization - If fertilizing is desired, consider the following points:

• Most lawns require little or no fertilizer to remain healthy. Fertilize

no more than twice a year - once in May-June, and once in

September- October; Fertilizers are rated on their labeling by three numbers (e.g., 10-10-10 or 12-4-8), which refer to their Nitrogen (N) – Phosphorus (P) – Potassium (K) concentrations. Fertilize at a rate of no more than ½ pound of nitrogen per 1000 square feet, which can be determined by dividing 50 by the percentage of nitrogen in the fertilizer;

• Apply fertilizer carefully to avoid spreading on impervious surfaces such as paved walkways, patios, driveways, etc., where the nutrient can be easily washed into storm drains or directly into surface waters;

• To encourage more complete uptake, use slow-release fertilizers that is those that contain 50 percent or more water-insoluble nitrogen (WIN);

• Grass blades retain 30-40 percent of nutrients applied in fertilizers. Reduce fertilizer applications by 30 percent, or eliminate the spring application of fertilizer and leave clippings on the lawn where they will degrade and release stored nutrients back to the soil; and

• Fertilizer should not be applied when rain is expected. Not only does the rain decrease fertilizer effectiveness, it also increases the risk of surface and ground water contamination.

f. Weed management - A property owner must decide how many weeds

can be tolerated before action is taken to eradicate them. To the extent practicable, weeds should be dug or pulled out. If patches of weeds are present, they can be covered for a few days with a black plastic sheet; a technique called solarization. Solarization kills the weeds while leaving the grass intact. If weeds blanket a large enough area, the patch can be covered with clear plastic for several weeks, effectively “cooking” the weeds and their seeds. The bare area left behind after weeding should be reseeded to prevent weeds from growing back. As a last resort, homeowners can use chemical herbicides to spot- treat weeds.

g. Pest management - Effective pest management begins with maintenance

of a healthy, vigorous lawn that is naturally disease resistant. Property owners should monitor plants for obvious damage and check for the presence of pest organisms. Learn to distinguish beneficial insects and arachnids, such as green lacewings, ladybugs, and most spiders, from ones that will damage plants.

When damage is detected or when harmful organisms are present, property owners should determine the level of damage the plant is able to tolerate. No action should be taken if the plant can maintain growth and fertility. If controls are needed, there are a variety of low-impact pest management controls and practices to choose from, including the following: • Visible insects can be removed by hand (with gloves or tweezers) and

placed in soapy water or vegetable oil. Alternatively, insects can be sprayed off a plant with water, or in some cases vacuumed off of

larger plants; • Store-bought traps, such as species-specific, pheromone-based traps or

colored sticky cards, can be used; • Sprinkling the ground surface with abrasive diatomaceous earth can

prevent infestations by soft-bodied insects and slugs. Slugs can also be trapped by falling or crawling into small cups set in the ground flush with the surface and filled with beer;

• In cases where microscopic parasites, such as bacteria and fungi, are causing damage to plants, the affected plant material can be removed and disposed of. (Pruning equipment should be disinfected with bleach to prevent spreading the disease organism);

• Small mammals and birds can be excluded using fences, netting, tree trunk guards, and, as a last resort, trapping. (In some areas trapping is illegal. Property owners should check local codes if this type of action is desired); and

• Property owners can encourage/attract beneficial organisms, such as bats, birds, green lacewings, ladybugs, praying mantis, ground beetles, parasitic nematodes, trichogramma wasps, seedhead weevils, and spiders that prey on detrimental pest species. These desirable organisms can be introduced directly or can be attracted to the area by providing food and/or habitat.

If chemical pesticides are used try to select the least toxic, water soluble and volatile pesticides possible. All selected pesticides should be screened for their potential to harm water resources. Although organophosphate pesticides, such as diazinon and chlorpyrifos, are popular because they target a broad range of pests and are less expensive than newer, less toxic pesticides, they rank among the worst killers of wildlife, and often pose the greatest health risk. Synthetic pyrethroids are more selective and typically much less toxic than organophosphates, yet they can harm beneficial insects. When possible, pesticides that pose the least risk to human health and the environment should be chosen. A list of popular pesticides, along with their uses, their toxicity to humans and wildlife, EPA’s toxicity rating, and alternatives to the listed chemicals, is available from The Audubon Guide to Home Pesticides, (http://www.audubon.org/bird/pesticides/).

h. Sensible irrigation - Most New England lawns will survive without

irrigation. Grasses will normally go dormant in warm, dry periods (June-September) and resume growth when moister is more plentiful. However, if watering is desired, consider the following points:

Established lawns need no more than one inch of water per week (including precipitation) to prevent dormancy in dry periods. Watering at this rate should wet soil to approximately 4-6 inches and will encourage analogous root growth. If possible, use timers to water before 9:00 a.m., preferably in the early morning to avoid evaporative loss. Use drought-resistant grasses (see “grass selection” above) and cut grass at 2-3 inches to encourage deeper rooting and heartier lawns.

http://www.audubon.org/bird/pesticides/)

Watermark

APPENDIX F

Storm Water Management System Operation and Maintenance Schedule

Retention/Detention System Maintenance

1

TECHNICAL NOTE

4 6 4 0 T R U E M A N B L V D . H I L L I A R D , O H 4 3 0 2 6 . ( 8 0 0 ) 8 2 1 - 6 7 1 0 – w w w . a d s - p i p e . c o m ATN601 ©ADS 2007

TN 6.01 February 2007

This document is provided for informational purposes only and is meant only to be a guide. Individuals using this information should make their own decisions as to suitability of this guideline for their individual projects and adjust accordingly.

Introduction

A retention/detention system is comprised of a series of pipes and fittings that form an underground storage area, which retains or detains storm water runoff from a given area. As sediment and debris settle out of the detained stormwater, build up occurs that requires the system to be regularly inspected and cleaned in order for the system to perform as originally designed. The following provides the available fittings and guidelines for inspection and maintenance of an HDPE underground storage system.

System Accessories and Fittings

Concentric Reducers Concentric Reducers are fittings that transition between two pipes, either in line with one another or at perpendicular angles. The centerlines of the two pipes are at the same elevation. When a concentric reducer is used to connect the manifold pipe to the lateral pipes, most debris will be trapped in the manifold pipe.

SIDE VIEW SECTION VIEWSIDE VIEW SECTION VIEW

Eccentric Reducers

Eccentric Reducers are fittings that transition between two pipes, either in line with one another or at perpendicular angles. The inverts of the two pipes are at the same elevations. When an eccentric reducer is used to connect the manifold pipe to the lateral pipes, most debris will follow the flow of the storm water into the lateral pipes.

SIDE VIEW SECTION VIEW SIDE VIEW SECTION VIEW

2 4 6 4 0 T R U E M A N B L V D . H I L L I A R D , O H 4 3 0 2 6 . ( 8 0 0 ) 8 2 1 - 6 7 1 0 – w w w . a d s - p i p e . c o m

Riser

Each retention/detention system typically has risers strategically placed for maintenance and inspection of the system. These risers are typically 24” in diameter or larger and are placed on the manifold fittings.

Cleanouts

Cleanout ports are usually 4-, 6-, or 8-in diameter pipe and are placed on the manifold fittings. They are used for entrance of a pipe from a vacuum truck or a water-jetting device. For a complete listing of available fittings and components please refer to the ADS Fittings Manual.

Maintenance Overview of a Retention/Detention System

Maintaining a clean and obstruction-free retention/detention system helps to ensure the system performs the intended function of the primary design. Build up of debris may obstruct flow through the laterals in a retention system or block the entranceway of the outlet pipe in a detention system. This may result in ineffective operation or complete failure of the system . Additionally, surrounding areas may potentially run the risk of damage due to flooding or other similar issues.

Inspection/Maintenance Frequency

All retention/detention systems must be cleaned and maintained. Underground systems may be maintained more cost effectively if these simple guidelines are followed. Inspection should be performed at a minimum of once per year. Cleaning should be done at the discretion of individuals responsible to maintain proper storage and flow. While maintenance can generally be performed year round, it should be scheduled during a relatively dry season.

Pre-Inspection

A post-installation inspection should be performed to allow the owner to measure the invert prior to accumulation of sediment. This survey will allow the monitoring of sediment build-up without requiring access to the retention/detention system.

The following is the recommended procedure for pre-inspections:

1) Locate the riser section or cleanouts of the retention/detention system. The riser will typically be 24” in diameter or larger and the cleanouts are usually 4”, 6” or 8” in diameter.

2) Remove the lid of the riser or clean outs. 3) Insert a measuring device into the opening and make note to a point of reference on the stick or string.

(This is done so that sediment build up can be determined in the future without having to enter the system.)

RISERCROSS-SECTION VIEW

CLEANOUTCROSS-SECTION VIEW

3 4 6 4 0 T R U E M A N B L V D . H I L L I A R D , O H 4 3 0 2 6 . ( 8 0 0 ) 8 2 1 - 6 7 1 0 – w w w . a d s - p i p e . c o m

Inspection/Maintenance

A retention/detention system should be inspected at a minimum of one time a year or after major rain events if necessary. The following is the recommended procedure to inspect system in service:

1) Locate the riser section of the retention/detention system. The riser will typically be 24” in diameter or larger.

2) Remove the lid from the riser. 3) Measure the sediment buildup at each riser and cleanout location. Only certified confined space entry

personnel having appropriate equipment should be permitted to enter the retention/detention System. 4) Inspect each manifold, all laterals, and outlet pipes for sediment build up, obstructions, or other

problems. Obstructions should be removed at this time. 5) If measured sediment build up is between 5% - 20% of the pipe diameter, cleaning should be

considered; if sediment build up exceeds 20%, cleaning should be performed at the earliest opportunity. A thorough cleaning of the system (manifolds and laterals) shall be performed by either manual methods or by a vacuum truck.

4640 TRUEMAN BLVD. HILLIARD, OH 43026 (800) 821-6710 www.ads-pipe.com 1 AIG202 © ADS 2008

Description / Basic Function The ADS Water Quality Unit harnesses the proven concepts utilized in municipal sewage treatment systems and transforms it into a compact Water Quality Unit. The unit is ideal for storm water applications including gas stations and fast food restaurants; this system gives you a highly effective BMP solution to meet EPA requirements.

STIFFINER PLATES

OUTLET ORIFICE

OIL CHAMBER

CHAMBER

STAND PIPE(BAFFLE, DISPERSION TUBE)

ENDPLATE

INLET STUB

OIL CHAMBER(INVERTED)

WEIR PLATE

SEDIMENT CHAMBER(SAW TOOTH)

WEIR PLATE

SEDIMENT CHAMBER

ENDPLATE

OUTLET STUB

N-12 ACCESS RISER(SEDIMENT RISER)

N-12 ACCESS RISER(OIL RISER)

Risers The ADS Water Quality Unit consists of two risers. A 24” riser is centered over Sediment and Oil Chambers. These two risers provide access to the individual chambers of the Storm Water Quality Unit for maintenance and inspection. Entry into the WQU should be considered an OSHA confined space and appropriate guidelines should be followed.

Maintenance Overview The purpose of maintaining a clean and obstruction free Water Quality Unit is to ensure the system performs its intended function. A build up of debris in excess of the design storage volume could reduce the efficiency of the system. A company specializing in such activities should perform inspection and maintenance of the Water Quality Unit. Inspection / Maintenance Frequency for the ADS Water Quality Unit

Inspected quarterly (4 times a year) and after major storm events. Cleaned (pumped and pressure washed) a minimum of once a calendar year Site or surrounding site conditions may require more inspections and maintenance

INSTALLATION GUIDE Storm Water Quality Units – Inspection & Maintenance

IG 2.02October 2008

2 4640 TRUEMAN BLVD. HILLIARD, OH 43026 (800) 821-6710 www.ads-pipe.com AIG202 © ADS 2008

Inspection An inspection should be performed when the system is installed. This allows the owner to measure the invert prior to accumulation of sediment. This survey will allow the monitoring of sediment build-up without entering the system, thereby eliminating the need for confined space entry. Documentation of pre-inspection data should be captured.

Procedures

1. In the By-Pass Structure inspect for blockage. Inspect the diversion structure and weir for damage and sediment buildup. Any damage should be repaired and sediment should be removed as required.

2. On the Water Quality Unit, locate the risers. The risers will be 24” in diameter. 3. Remove the lid of each riser. It is recommend that this be done one at a time so an open riser is not left

exposed during inspection or maintenance of the other risers. 4. In the 24” riser over the Sediment Chamber, inspect the amount of floatable debris. Then measure the

sediment buildup with a measuring device such as a Sludge Judge® Also inspect that the inlet pipe does not have any blockage. Blockage inspection is better suited after unit is vacuumed. Any confined space entry would be done through this riser and OSHA requirements must be followed.

5. In the 24” riser over the Oil Chamber, measure / inspect the oil depth. 6. Inspect structure and components for any damage. 7. Replace all riser lids.

Maintenance Cleaning should be performed if sediment volume has reduced the storage area by 20% or if the depth of sediment has reached approximately 25% of the diameter of the structure (See Table 1 for cleanout depth information). Furthermore, the system may need cleaning in the event a spill of a foreign substance enters the unit. Inspection Procedures (Measuring Sediment Depth)

1. Lower measuring device into sediment riser of unit. 2. Read measurement at ground surface. 3. Subtract the current measurement reading from the distance between the ground surface to the invert of the

SWQU (obtained when unit was first installed or is clean). 4. Compare calculated difference to the respective value in Table 1. If resulting value is equal to or greater than

the respective value on the Table 1, maintenance shall be performed. The figure below illustrates the inspection procedure.

Table 1

Sediment Depth at Cleanout

Model Number

Diameter (jn)

Sediment Depth (in)

3620WQ 36 9 3640WQ 36 9 4220WQ 42 10 4240WQ 42 10 4820WQ 48 12 4840WQ 48 12 6020WQ 60 15 6040WQ 60 15

GROUND SURFACE

WATER SURFACE

SEDIMENT

FLOTABLES

MEASURING DEVICE

4640 TRUEMAN BLVD. HILLIARD, OH 43026 (800) 821-6710 www.ads-pipe.com 3 AIG202 © ADS 2008

Cleaning Procedures

1. Insert vacuum hose into By-Pass Structure and pump out. Inspect By-Pass Structure for any damage.

2. Insert vacuum hose into 24” riser and pump out the Sediment Chamber. Pressure wash this Chamber if needed. Inspect for any damage. Inspect the inlet pipe for any blockage. Also inspect weir plate for damage.

3. Insert vacuum hose into other 24” riser. This will pump out the Oil Chamber. Inspect for any structural damage. Pressure wash this Chamber if needed.

4. Refill water quality unit with water. 5. Replace all riser lids.

The owner or operator is responsible for meeting all federal, state, and local laws and regulations during the maintenance and cleanout operations.

Material Disposal Owners are responsible for complying with all federal, state, and local regulations when disposing of material collected from the storm water quality unit. Water and sediment from cleanout procedures should not be dumped into sanitary sewer.

Rhode Island Stormwater Design and Installation Standards Manual December 2010

APPENDIX E: GUIDANCE FOR DEVELOPING OPERATION AND MAINTENANCE PLANS E-13

Infiltration System Operation, Maintenance, and Management Inspection Checklist

Project: Location: Site Status: Date: Time: Inspector:

MAINTENANCE ITEMSATISFACTORY /UNSATISFACTORY

COMMENTS

1. Debris Cleanout (Annual)

Trench/chamber or basin surface clear of debris

Inflow pipes clear of debris

Overflow spillway clear of debris

Inlet area clear of debris

2. Sediment Traps or Forebays (Annual)

Obviously trapping sediment

Greater than 50% of storage volume remaining

3. Dewatering (Annual)

Trench/chamber or basin dewaters between storms

4. Sediment Cleanout of Trench/Chamber or Basin (Annual)

Rhode Island Stormwater Design and Installation Standards Manual December 2010

APPENDIX E: GUIDANCE FOR DEVELOPING OPERATION AND MAINTENANCE PLANS E-14

MAINTENANCE ITEMSATISFACTORY /UNSATISFACTORY

COMMENTS

No evidence of sedimentation in trench/chamber or basin

Sediment accumulation doesn’t yet require cleanout

5. Inlets (Annual)

Good condition

No evidence of erosion

6. Outlet/Overflow Spillway (Annual)

Good condition, no need for repair

No evidence of erosion

7. Aggregate Repairs (Annual)

Surface of aggregate clean

Top layer of stone does not need replacement

Trench/Chamber or basin does not need rehabilitation

Comments: Actions to be Taken:

10408-07-wld1539- final design analysis - rev 1

Documents

naval station newport

design criteria

subsurface investigations

atlantic pwd newport

simonpietri drive newport

site investigations

hazardous materials

subsurface conditions