APPENDIX G DESIGN CRITERIA

APPENDIX G

DESIGN CRITERIA

220100280001.R1 FnlWorkPlan Final Project Work Plan IR Sites 5 and 10 (Buildings 5 and 400)

Storm Drain and Sewer Line TCRA Former Naval Air Station Alameda DCN: ECSD-2201-0028-0001.R1

CTO No. 0028, 06/13/08

TABLE OF CONTENTS

PAGE

ABBREVIATIONS AND ACRONYMS................................................................................... G.ii

1.0 INTRODUCTION AND PURPOSE ........................................................................... G.1-1 1.1 SITE BACKGROUND AND DESIGN PERIOD ........................................... G.1-1

2.0 DESIGN CRITERIA/DESIGN CONSTRAINTS ....................................................... G.2-1 2.1 SYSTEM COMPONENTS.............................................................................. G.2-1

2.1.1 Existing Storm Drain and Sewer Lines ............................................ G.2-1 2.1.2 New Storm Drain System Design and Installation........................... G.2-1 2.1.3 Shoring ............................................................................................. G.2-2 2.1.4 Dewatering ....................................................................................... G.2-2 2.1.5 Trench Excavation............................................................................ G.2-2 2.1.6 Backfill ............................................................................................. G.2-2 2.1.7 Site Restoration ................................................................................ G.2-3 2.1.8 Layout of Work and Surveys ........................................................... G.2-3 2.1.9 Dewatering and Screening Pads ....................................................... G.2-3

2.2 CODES AND STANDARDS.......................................................................... G.2-4

3.0 HEALTH AND SAFETY CONSIDERATIONS ........................................................ G.3-1

4.0 REFERENCES ............................................................................................................ G.4-1

220100280001.R1 Appendix GDrFnlDesnCrit G.i Draft Final Design Criteria IR Sites 5 and 10 (Buildings 5 and 400)

Storm Drain and Sewer Line TCRA Former Naval Air Station Alameda

DCN: ECSD-2201-0028-0001 CTO No. 0028, 11/13/07

ABBREVIATIONS AND ACRONYMS

IR Installation Restoration NAS Naval Air Station OSHA Occupational Safety and Health Administration RAD radiological TCRA time-critical removal action

220100280001.R1 Appendix GDrFnlDesnCrit G.ii Draft Final Design Criteria IR Sites 5 and 10 (Buildings 5 and 400)


DCN: ECSD-2201-0028-0001 CTO No. 0028, 11/13/07

1.0 INTRODUCTION AND PURPOSE

This document specifies the design criteria to be used for the removal of storm drain and sewer lines at Operable Unit (OU)-2C, Buildings 5 and 400 at the former Naval Air Station Alameda, Alameda Point, Alameda, California. The scope of work includes shoring of areas adjacent to buildings, excavation and dewatering, removal of pipes, radiological (RAD) clearing trenches, replacement of the storm lines, backfill, and re-pavement. The removed sewer lines are not to be replaced. The purpose of this time critical removal action (TCRA) is to remove RAD-contaminated lines and impacted surrounding soil rather than general site/facility improvement. Therefore, the design criteria will specify minimum standards to match the intent of the TCRA.

1.1 SITE BACKGROUND AND DESIGN PERIOD

The storm and sewer lines to be removed are located inside and adjacent to Buildings 5 and 400 at the former Naval Air Station (NAS) Alameda, Alameda Point, Alameda, California. The former NAS Alameda is scheduled to be redeveloped and turned over to the city in phases starting in 2008 through 2023 (Alameda Reuse and Redevelopment Authority, 2006). Phase 1 of the redevelopment program covers infrastructure work for Installation Restoration (IR) Sites 5 and 10, Buildings 5 and 400. Phase 2 of the plan proposes demolish /redevelopment of Buildings 5 and 400, which is anticipated to be performed between 2012 and 2017.

It is expected that the existing storm drainage system, which currently does not meet the City of Alameda Standards, will be revamped and redeveloped as part of a master stormwater/flood control system. Because the area will eventually be developed, general systems and components will be designed for temporary and limited use and the general design period will be 10 years or industry standard time frame, whichever is less. In addition, improvements will be limited to replacement of the storm drain system to accommodate the 10-year storm. No site grading is planned.

220100280001.R1 Appendix GDrFnlDesnCrit G.1-1 Draft Final Design Criteria IR Sites 5 and 10 (Buildings 5 and 400)


DCN: ECSD-2201-0028-0001 CTO No. 0028, 11/13/07

2.0 DESIGN CRITERIA/DESIGN CONSTRAINTS

Current Alameda Public Utilities Subdivision Regulations specify that new systems shall be designed to carry the peak run off from a 10-year storm. Specific design criteria and constraints are described below. Design details shall be shown in design drawings and outlined in construction specifications as applicable.

2.1 SYSTEM COMPONENTS

The design system components include new storm drain system design and installation, shoring, dewatering, trench excavation, backfill, pavement repair, and design of dewatering and radiological sampling pads.

2.1.1 Existing Storm Drain and Sewer Lines

The existing lines were identified using Final Report, Alameda Naval Air Station Storm Drain Removal Project, Delivery Order # 65, New World Technology (NWT), February 18, 2000, and Comprehensive Long-Term Environmental Action Navy, Alameda Point, IR Sites 1, 2, 5, & 10 and Storm Drain Lines, Radiological Removal Action Drawings for Implementation Work Plan (Tetra Tech EM, Inc. [TtEMI] Morrison Knudsen, 1998). Existing information was incorporated into the design drawings, which are attached. Further confirmation is necessary through a site survey.

2.1.2 New Storm Drain System Design and Installation

The new storm water drainage system can be installed in the existing storm drain system, or at an adjacent new location. Both options should be evaluated. Considerations should include ease of construction, schedule, and the location of the existing lines to be removed. The new system shall be connected to the existing and remaining storm drain lines at the site.

Pipe, manhole, catch basin, and outfall design will be performed using results from hydrology calculations based on a 10-year storm. City of Alameda Standard Plans dated 1998 shall be used to detail these storm drain system components.

The site is equipped with monitoring wells. Some of these wells will be destroyed due to storm line removal action. Additional destruction of monitoring wells due to installation of the new storm drain system shall be minimized to the extent possible.



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2.1.3 Shoring

Adequate shoring is necessary to prevent failure of adjacent foundation/structures. The shoring system is to be designed by a qualified specialty shoring contractor and shall meet the requirements of Occupational Safety and Health Administration (OSHA) Guidelines and the Caltrans Trenching and Shoring Manual. Design review by a California licensed Professional Engineer (PE) will be required.

2.1.4 Dewatering

Dewatering is necessary to assist in the excavation and to perform a necessary radiological surface scan. The dewatering system shall be designed for trench excavation with lengths up to 500 feet, and a minimum drawdown of about 7 feet. Available monitoring well logs should be used to identify subsurface conditions and groundwater table elevations.

2.1.5 Trench Excavation

Sidewall slopes of trenches shall be kept un-sloped (vertical), if conditions allow, to minimize the soil volume to be scanned for radiological contamination. Dewatering of trenches and sloping of sidewalls may be required to facilitate pipe removal/installation operations. If personnel entry is necessary, adequate shoring/sloping/benching shall be required per California OSHA rules and regulations.

Storm drain lines, sanitary sewer lines, soil, and debris characterized as radiologically contaminated are to be placed in a lined dump truck for on-site transport to radiological sample pads for further survey.

Excavation in contaminated groundwater plume areas is a concern because of the presence of shallow groundwater. Crossings through contaminated groundwater plume areas shall be minimized whenever possible.

2.1.6 Backfill

Pipe trench excavations, backfilling, and compaction shall be performed in accordance with the City of Alameda standard plans. Trench excavations shall be backfilled to match the original grade. Backfill material shall consist of clean import material with acceptable chemical/RAD levels as approved by the engineer/compliance person, as well as poorly graded river rock and/or crushed stone.

Specific compaction and gradation requirements for pipe bedding, intermediate fill, and engineered fill shall be outlined in the construction specifications based on the City of Alameda



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standard plans. Compaction and gradation requirements shall identify the backfill requirements for both improved and unimproved surfaces.

Geotechnical subsurface conditions (i.e., the presence of the Young Bay Mud layer susceptible to consolidation and settlement), shall be considered during pipe foundation preparation and selection of bedding material. If the trench bottom does not provide a firm, dry, and stable working platform, sufficient materials will be removed and replaced with approved materials in order to provide a stable foundation.

2.1.7 Site Restoration

All surface restoration will adhere to the requirements of the City of Alameda standard plans. Pavement restoration shall be a maximum of 12 inches thick or match existing pavement, whichever is less. Unimproved surfaces, including landscaped areas, shall be restored to original condition.

2.1.8 Layout of Work and Surveys

Detailed design drawings, including all lines and grades of existing and proposed structures, shall be provided in NAD 83 coordinates and shall be stamped by a California Licensed PE. Based on the design drawing coordinates the storm drain system alignment will be staked out prior to excavation and installation. Existing storm and sewer systems to be removed will also be identified based on the design drawing coordinates.

During installation as-built surveys for the storm drain system will be completed at intervals of not less than 40 feet, at significant grade or direction changes, and at storm drain structures such as manholes, drop inlets, and outfalls. The as-built survey information will also include the location and elevation of all utility line crossings and the elevation of the storm drain pipeline at the crossing point. The location and extent of soil excavation during the removal of existing storm and sewer systems will also be recorded in the as-built survey. As-built record drawings will be provided in NAD 83 coordinates and shall be stamped by a Professional California Land Surveyor.

2.1.9 Dewatering and Screening Pads

The size of the RAD screening pads shall be 1,000 square meters per the Multi-Agency Radiation Survey and Site Investigation Manual (Department of Defense [DOD], et al., 2000). A berm consisting of sandbags, asphalt, concrete blocks or engineering-approved equivalent shall be used to separate the pads. A main collection point, where water will drain, shall be established. A



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minimum slope of 0.25 percent is required to adequately drain to the collection point. For areas that have a natural valley (low point), aggregate base shall be installed for proper drainage.

2.2 CODES AND STANDARDS

• Alameda County Flood Control District, Hayward, CA. 2003. Alameda County Hydrology and Hydraulic Manual.

• Caltrans Highway Design Manual. 2004.

• Caltrans Storm Water Quality Handbooks, Construction Site Best Management Practices Manual. 2003.

• Caltrans Storm Water Quality Handbooks, Project Planning and Design Guide. 2005.

• Caltrans Trenching and Shoring Manual Revision 12. 2000. Available at www.dot.ca.gov/ hq/esc/construction/construc.htm.

• City and County of Alameda, CA. 1965. City of Alameda Standard Subdivision Specifications and Design Criteria. Bureau of Engineering Department of Public Works.

• City and County of Alameda, CA. 1998. City of Alameda Standard Plans. Bureau of Engineering Department of Public Works.

• OSHA Technical Manual, Section 5, Chapter 2. Available at www.osha.gov /dts/osta/otm/otm_toc.html

Technical specifications providing corresponding codes and standards for specific design components will be included in the Draft 90% Design Package for Storm Drain Replacement Project for IR Sites 5 and 10.

http://www.dot.ca.gov/

http://www.osha.gov/

3.0 HEALTH AND SAFETY CONSIDERATIONS

Use of lead, hazardous waste-producing materials, and ozone-depleting compounds shall be avoided in accordance with the site Waste Minimization and Pollution Prevention Plan. If any of these materials must be used, justification will be required and Tetra Tech EC, Inc. must approve the items prior to installation.



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4.0 REFERENCES

Alameda Reuse and Redevelopment Authority. 2006. Alameda Point Preliminary Development Concept. A Planning Study for the Redevelopment and Reuse of the Former Alameda Naval Air Station, www.alameda-point.com/pdf/Feb06PDC.pdf.

City, County, and State Codes and Standards (listed in Section 2.2).

Department of Defense (DoD), Department of Energy, Nuclear Regulatory Commission (NRC), and U.S. Environmental Protection Agency (EPA). 2000. Multi-Agency Radiation Survey and Site Investigation Manual (MARSSIM) NUREG-1575. August.

New World Technology. 2000. Final Report, Alameda Naval Air Station Storm Drain Removal Project, Delivery Order #65. February.

Tetra Tech EM, Inc. 1998. Comprehensive Long-Term Environmental Action Navy, Alameda Point, IR Sites 1, 2, 5, & 10 and Storm Drain Lines, Radiological Removal Action Drawings for Implementation Work Plan. April.

U.S. Environmental Protection Agency. 2000. Multi-Agency Radiation Survey and Site Investigation Manual. EPA 402-R-97-016, Rev.1.

220100280001.R1 Appendix GDrFnlDesnCrit Draft Final Design Criteria IR Sites 5 and 10 (Buildings 5 and 400)


DCN: ECSD-2201-0028-0001 CTO No. 0028, 11/13/07

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Documents

APPENDIX G DESIGN CRITERIA