OSWER Policy Directive No.  9483.00-1

                               EPA/530-SW-86-044
Technical  Resource Document for the Storage and Treatment of
               Hazardous  Waste  In  Tank  Systems
                        Prepared  for:

            U.S. Environmental Protection Agency
                    Office  of  Solid  Waste
                  Waste  Management Division
                   Waste Treatment Branch
                    Washington, DC   20460
                        December  1986

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                               TABLE OF CONTENTS


                                                                 Page


Table of Contents 	     i-vi i

List of Figures 	     vi 11-x

List of Tables 	     xi-xiii

List of Acronyms  	     xiv

EXECUTIVE SUMMARY 	       1

1.0  INTRODUCTION

     1.1  Applicability 	     1-1
     1.2  Purpose of the Document 	     1-1
     1.3  Specific Information Requirements  	     1-3
     1.4  Organization of the Document  	     1-5
     1.5  Other Guidance Manuals  	     1-6

2.0  BACKGROUND

     2.1  Status  of Subtitle C—Hazardous  Waste  Management  ...     2-1
     2.2  Status  of Subtitle C Rulemaking  for  Tanks 	     2-1

3.0  THE PERMITTING PROCESS

     •3.1  Permitting Steps 	    -3-3
     3.2  The Permit Application  and the  Permit  	     3-6
     3.3  Where to Submit Applications  	     3-7
     3.4  Confidentiality 	     3-7
     3.5  Appeals 	     3-9

4.0  WRITTEN ASSESSMENT OF TANK SYSTEMS

     4.1  Tank. System Design and  Testing  	     4-2
          A)  Design Standards 	     4-6
          B)  Characteristics of  Waste  	     4-12
          C)  Corrosion Protection Measures  	     4-20
          D)  Documented Age of the Tank  System  	     4-20
          E)  Leak-Tests, Inspections,  and Other
              Examinations 	     4-20
              1.   Temperature 	     4-26
              2.   Water Tables 	     4-28
              3.   Tank End Deflection 	     4-28
              4.   Evaporation 	     4-30
              5.   Trapped Air and Vapor Pockets  	     4-30
              6.   Sludge 	     4-31

                                       i

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                          TABLE OF  CONTENTS  (Continued)
                                                                 Page

          F)  Internal  Inspections 	     4-31
              1.  Preparation for Internal  Inspection -
                   Tank Cleaning 	     4-31
              2.  Internal  Inspection 	     4-34
          G)  Ancillary Equipment Assessment 	     4-41
          H)  Assessment Schedule 	     4-41
          I)  Leaking or Unfit-For-Use Tank Systems 	     4-42
     4.2  Summary of Major Points 	     4-42

5.0  DESIGN OF NEW TANK SYSTEMS
       OR COMPONENTS

     5.1  Dimensions and Capacity of the Tank 	     5-1
          A)  Aboveground Tanks 	     5-6
          B)  Underground Tanks 	     5-7
     5.2  Description of Feed  Systems, Safety Cutoff,
          Bypass  Systems,  and  Pressure Controls 	     5-10
          A)  Feed Systems 	     5-11
              1)   Level Sensors 	     5-11'
              2)   Alarm System 	     5-12
              3)   Liquid Transfer 	     5-12
          B)  Safety Cutoff or Bypass Systems 	     5-14
          C)  Pressure Controls (e.g., Vents) 	     5-14
     5.3  Diagram of Piping, Instrumentation,
          and Process Flow 	     5-18
     5.4  External Corrosion Protection 	     5-23
          5.4.1   Corrosion Potential Assessment 	     5-23
              A)   Soil  Moisture Content 	     5-30
              8)   Soil  Resistivity 	     5-31
              C)   Soil  Sulfides Level 	     5-33
              D)   Soil  pH 	     5-33
              E)   Structure-to-Soi1  Potential 	     5-34
              F)   Influence of Nearby Underground Metal
                  Structures 	     5-34
              G)   Existence of Stray Electric Current  	     5-35
              H)   Existing Corrosion Protection Measures 	     5-36
          5.4.2  Corrosion Protection Assessment 	     5-38
              A)   Corrosion-Resistant Materials of
                  Construction 	     5-39
              B)   Corrosion-Resistant Coating 	     5-39
              C)   Cathodic Protection	     5-42
                  1)  Sacrificial Anode	     5-43
                  2)  Impressed Current 	     5-43
              D)   Electrical Isolation Devices 	     5-46
     5.5  Protection From Vehicular Traffic  	     5-48
     5.6  Foundation Load & Anchoring 	     5-49
                                       11

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                         TABLE OF CONTENTS (Continued)
     5.7  Protection Against Frost Heave
     5.8  Summary of Major Points 	
6.0  INSTALLATION OF NEW TANK SYSTEMS
     6.1
          Proper Handling Procedures
          A)  Installation Inspectors
          B)
          C)
          D)
Qualified,
Engineers .
Inspection
                                      Registered
                                      Procedures
     6.2
     6.3
    Independent,
    Professional
    Instal lation
    Repai rs .....................................
Back.fi 1 1 i ng .....................................
A)  Backfill  Material  ...........................
B)  Backfill  Placement ..........................
Pre-Service Tank  and Ancillary Equipment Testing
A)  Tanks  .......................................
B)  Piping ......................................
C)  Repairs ....................................
Ancillary  Equipment Installation ................
Corrosion  Protection System Installation .......
Certifications of Design and Installation ......
Description of Tank System Installation .........
Summary of Major  Poi nts ........................
7.0  SECONDARY CONTAINMENT SYSTEMS AND RELEASE DETECTION

     7.1   Secondary Containment Implementation Schedule ..
     7.2   Properties of a Secondary Containment System ...
     7.3   Design Parameters 	
          A)  Compatibility and Strength 	
          B)  Foundation Integrity 	
          C)  Leak Detection Capability 	
              1)  Tank Excavation Monitoring Systems 	
              2)  Leak Sensors 	
              3)  Interstitial Monitoring (Leak Detection)
          D)  Adequate Drainage	
     7.4   Types of Secondary Containment 	
     7.5   Liner Requirements  	
          A)  Concrete 	
          B)  Synthetic Flexible Membranes
          C)  Clay 	
          D)  Bentonites 	
          E)  Soil Cement 	
          F)  Asphalt 	
     7.6  Vault Requirements 	
     7.7  Double-Walled Tank Requirements .
                                                                 Page

                                                                  5-53
                                                                  5-55
6-1
6-2

6-3
6-3
6-7
6-13
6-13
6-14
5-18
6-18
6-19
6-19
6-20'
6-23
5-27
6-29
6-29
                                                                  7-2
                                                                  7-3
                                                                  7-4
                                                                  7-5
                                                                  7-8
                                                                  7-8
                                                                  7-9
                                                                  7-12
                                                                  7-18
                                                                  7-19
                                                                  7-21
                                                                  7-21
                                                                  7-30
                                                                  7-34
                                                                  7-35
                                                                  7-36
                                                                  7-36
                                                                  7-37
                                                                  7-37
                                                                  7-44
                                       11'

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                          TABLE  OF  CONTENTS  (Continued)
                                                                 Page

     7.8  Ancillary Equipment With Secondary Containment 	    7-46
          A)  Lined Trenches 	    7-49
          B)  Concrete Trenches 	    7-50
          C)  Double-Walled Piping 	    7-51
          D)  Jacketing 	    7-51
     7.9  Summary of Major Points 	    7-53

8.0  VARIANCES FROM SECONDARY CONTAINMENT

     8.1  Technology-Based Variance 	    8-2
          A)  Releases to the Zone of Engineering Control  ....    8-5
          B)  Releases Outside the Zone of Engineering
              Control 	    8-6
     8.2  Risk-Based Variance 	    8-7
          A)  Source 	    8-9
          B)  Transport Media 	    8-10
          C)  Receptors 	    8-11
          D)  Risk-Based Variance Examples 	    8-12
     8.3  Variance Implementation Procedures 	    8-14'
     8.4  Summary of Major Points 	    8-15

9.0  CONTROLS AND PRACTICES TO PREVENT SPILLS AND OVERFILLS

     9.1  Underground Tanks 	    9-2
          A)  Elements of an Overfill  Prevention System
              For Underground Storage Tanks 	    9-2
              1)  Automatic Shutoff Controls 	    9-3
              2)  Level-Sensing Devices and Indicators 	    9-3
              3)  High-Level Alarms 	    9-11
          B)  Transfer Spill-Prevention Systems
              For Underground Tanks 	    9-11
              1)  Check Valves 	    9-13
              2)  Couplings 	    9-13
          C)  Proper Operating Practices During
              Loading and Unloading 	    9-19
     9.2  Aboveground/Inground/Onground Tanks 	    9-22
          A)  Elements of an Overfill  Prevention System
              For Aboveground/Inground/Onground Storage
              Tanks  	    9-24
              1)  Level-Sensors and Gauges 	    9-24
              2)  High-Level Alarms	    9-36
              3)  Automatic Shutdown or Flow Diversion 	    9-37
              4)  Emergency Overflow to Adjacent Tanks 	    9-37
              5)  Monitoring Systems	    9-38
          B)  Transfer Spill Prevention Systems
              For Aboveground/Inground/Onground Tanks 	    9-39
              1)  Dry-Disconnect Couplings 	    9-39
                                       iv

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                         TABLE OF CONTENTS (Continued)
              2)   Redundant Valving  and  Instrumentation  	     9-39
           C)  Proper  Operating Practices  During  Loading
              and  Unloading 	     9-40
              1)   Proper  Transfer  Practices  	     9-40
              2)   Recommended  Areas  for  Transfer  Operations  ..     9-40
              3)   Inspection and Maintenance  	     9-40
     9.3  Uncovered Tanks—Freeboard 	     9-41
     9.4  Summary  of  Major Points  	     9-42

10.0  INSPECTIONS

     10.1   Schedule and Procedures for Overfill Control
           System  Inspections  	    10-3
     10.2  Daily Inspections of Aboveground  Portions  of
           Tank Systems and Monitoring and  Leak
           Detection  Data 	    10-6
           A)  Valves,  Pipes, Fittings, and  Hoses  	    10-8
           B)  Pumps and Compressors  	    10-9  .
           C)  Heat Exchangers  	    10-10
           D)  Vapor-Control Systems  	    10-10
     10.3   Daily  Inspection of Construction Materials,
           Local Areas, and Secondary Containment System
           for Erosion and Leakage  	    10-11
     10.4   Inspection of  Cathodic-Protection  Systems 	    10-15
           A)  Cathodic-Protection  Systems  	    10-16
           B)  Inspection  of Impressed-Current Systems  	    10-16
     10.5   Inspection Requirements Before  Full  Secondary
           Containment is Provided  	    10-18
     10.6   Fiberglass-Reinforced Plastic  (FRP)  Tanks 	    10-20
     10.7   Concrete Tanks 	    10-20
     10.8   Inspection Tools and Electromechanical  Equipment  ..    10-22
     10.9   Reporting  Requirements  	    10-25
     10.10 Summary of Major Points  	    10-25

11.0 RESPONSE  TO  LEAKS OR SPILLS AND DISPOSITION  OF  LEAKING
     OR UNFIT-FOR-USE TANK SYSTEMS

     11.1   Response Actions for Leaks or  Spills  	    11-4
           11.1.1  Waste Flow Stoppage 	    11-4
           11.1.2  Waste Removal 	    11-4
           11.1.3  Visible Release  Containment 	    11-6
           11.1.4  Repair, Replacement, or  Closure 	    11-10
           11.1.5  Certification of Major  Repairs  	    11-16
     11.2  Required Notifications and Reports  	    11-17
     11.3  Summary  of  Major Points  	    11-18

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                          TABLE OF CONTENTS  (Continued)
12.0 CLOSURE AND POST-CLOSURE REQUIREMENTS -

     12.1  Decontamination/Removal  Procedures for
          Closure:   Where Decontamination and Removal
          of Wastes is Practicable and Where Secondary
          Containment is Provided  (Category A)  	     12-3
          A)  Recommended Decontamination Criteria 	    12-5
          B)  Procedures for Abandoning Underground Tanks
              In Place (General)  	    12-7
          C)  Procedures for Abandoning Underground Tanks
              In Place (Sand-Pumping)  	    12-8
          0)  Procedures for Abandoning Onground,  Inground,
              Aboveground Tanks  In Place 	    12-10
          E)  Procedures for Preparation for Removal  and
              Disposal of Tanks  	    12-10
     12.2  Closure Plan and Closure Activities:   The
          Part B Application 	    12-12
     12.3  Closure of Tank System:   When Decontamination
          and Removal of Waste is  Not  Practicable  and
          and Where Secondary Containment is Provided
          (Category B)	    12-15
     12.4  Closure and Post-Closure Requirements:
          For Tank Systems That  Do Not Have Secondary
          Containment (Categories  C and D)	    12-18
     12.5  Closure/Post-Closure Cost Estimates 	    12-19
          A)  Closure Cost Estimates 	    12-20
          B)  Post-Closure Cost  Estimates 	    12-22
     12-6  Financial Assurance for  Closure and Post-Closure
          Care 	    12-23
          A)  Financial  Assurance  for  Closure Care 	    12-23
          B)  Financial  Assurance  for  Post-Closure Care 	    12-23
     12.7  Summary of Major Points  	    12-23

13.0 PROCEDURES FOR TANK SYSTEMS THAT  STORE OR TREAT
     IGNITABLE, REACTIVE, OR INCOMPATIBLE WASTES

     13.1  Ignitable or Reactive  Wastes, General  Precautions  ..    13-1
     13.2  Distance Requirements  for Ignitable or Reactive
          Wastes 	    13-7
     13.3  Incompatible Wastes 	    13-20
     13.4  Summary of Major Poi nts  	    13-33

APPENDIX A:   COMPLETENESS CHECKLIST

APPENDIX B:   PAINT FILTER LIQUIDS  TEST
                                       VI

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                          TABLE  OF  CONTENTS  (Continued)



APPENDIX C:  SYNOPSIS OF PERTINENT EPA GUIDANCE MANUALS

APPENDIX D:  TECHNICAL GUIDANCE DOCUMENTS

APPENDIX E:  DEFINITIONS

APPENDIX F:  FIGURE SOURCES

APPENDIX G:  COMPATIBILITY TEST FOR WASTES AND MEMBRANE LINERS
             (EPA Method 9090)


BIBLIOGRAPHY
                                       vii

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                                 LIST OF  FIGURES

Figure No.      "Title                                             Page
   5-1         Tank Dimensions 	   5-3
   5-2         Tank Dimensions (cont.)  	   5-4
   5-3         Tank Dimensions (cont.)  	   5-5
   5-4         Piping Details for Suction or Submerged Pumps  ..   5-20
   5-5         Elements of an Underground Storage Facility ....   5-21
   5-6         Aboveground Tank System  Connections 	   5-22
   5-7         Corrosion Mechanisms  	   5-28
   5-8         Corrosion Mechanisms  (cont.)  	  5-29
   5-9         Sacrificial-Anode Cathodic Protection 	   5-44
  5-10         Factory-Installed Sacrificial-Anode 	   5-45
  5-11         Impressed-Current Cathodic Protection 	   5-47
  5-12         Anchoring Techniques	   5-51
   6-1         Proper Tank Lifting and  Placement 	   6-5
   6-2         Excavation Design:  Recommended Distance
                 from the Nearest Foundation 	   6-8
   6-3         Excavation 	   6-9
   6-4         Tank Installation Checklist	   6-10
   6-5         Backfill 	   6-16
   6-6         Partially Buried Vertical  Hazardous Waste
                 Tank with Secondary Containment 	   6-24
   6-7         Underground Tank and  Piping System 	   6-25
   6-8         Aboveground Tank  	   6-26
   7-1         Observation Well Installation	   7-13
   7-2         U-Tube Placement	   7-14
                                      viii

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                           LIST OF  FIGURES  (Continued)
Figure No.      Title
   7-3         Detail:   Secondary Containment for
                 Aboveground Tanks 	   7-20
   7-4         Tank With External Liner 	   7-22
   7-5         New Aboveground Tank 	   7-23
   7-6         Multiple Tanks in a Vault 	   7-24
   7-7         Double-Walled Tank Configurations 	   7-25
   7-8         Cross Sectional View of a Double-Walled Tank ...   7-26
   7-9         Typical  Earthen Dike Construction 	   7-28
  7-10         Intersection of Flexible Membrane Trench
                 Liner  and Tank Excavation Liner 	   7-29
  7-11         Waterproofing at Corner of Vault Base 	   7-40
  7-12         Tank Wrapped in Flexible Membrane 	   7-45
  7-13         Example  Containment Structure for Pump
                 and Valve Installation 	;	   7-48
  7-14         Doub'le-Walled Pipe System 	   7-52
   9-1         Tape Float Gauge for Underground Storage
                 Tanks  	   9-7
   9-2         Float Vent Valves	   9-8
   9-3         Optical  Liquid Level Sensing System for
                 Bulk Storage System 	   9-12
   9-4         Types of Valves - Example One 	•>	   9-15
   9-5         Types of Valves - Example Two 	   9-16
   9-6         Check Valves Used to Prevent Backflow 	   9-17
   9-7         Cross Sections of Check Valves 	   9-18
   9-8         Types of Coupl i ngs  	   9-20
   9-9         Elements of an Overfill Prevention System 	   9-23
                                       ix

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                           LIST OF  FIGURES  (Continued)

Figure No.      Ti tie                                             Page
  9-10         Chain and Tape Float Gauges  	   9-27
  9-11         Level and Shaft Float Gauges	   9-28
  9-12         Magnetically Coupled Floats	   9-29
  9-13         Flexure Tube Displacer 	   9-31
  9-14         Magnetically Coupled Displacer 	   9-32
  9-15         Torque Tube Displacer 	   9-33
  9-16         Bubble Tube System 	   9-35
  9-17         Loading Arm Equipped With Automatic Shutoff ....   9-38
  10-1         Areas of Concern in a Typical  Tank Foundation ..  10-14
  13-1         40 CFR 261.21  Characteristics  of Ignitabi1ity,
                 and 40 CFR 261.23 Characteristics of
                 Reactivity 	   13-3
  13-2         40 CFR 264.17  General Requirements for
                 Ignitable, Reactive or Incompatible  Hastes ...   13-4
  13-3         Compatibility  Matrix	   13-29,30

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                                 LIST OF TABLES



Table No.       Title                                             Page

   1-1          Exemptions from 40 CFR 264,  Subpart J 	   1-2

   2-1          Resource Conservation and Recovery Act 	   2-2

   3-1          Sections of 40 CFR Parts  270 and  264 Addressed
                 In this Manual  	   3-2

   3-2          EPA Regional  Hazardous Waste Program Offices  ...   3-4

   4-1          Nationally Accepted Tank.  Design Standards  	   4-7

   4-2          Impact of Selected Waste  Properties on Tank.
                 Design 	   4-13

   4-3          Compatibility of Materials of Construction
                 With Various Chemicals  	   4-14

   4-4          General  Information on Leak-Testing Devices ....   4-22

   4-5          Thermal  Expansion of Liquids 	   4-76

   4-6          Total Force on Tank Ends  	   4-29

   4-7          Checklist for Tank Internal  Inspection 	   4-35

   5-1          Vertical and Horizontal  Aboveground Steel
                 Tank Minimum Wai 1 Thickness 	   5-8

   5-2          Aboveground Reinforced-Plastic Tank Minimal
                 Graduated Wall  Thickness 	   5-9

   5-3          Common Forms of Localized Corrosion 	   5-26

   5-4          Environments That Can Cause Corrosion 	   5-27

   5-5          Coating/Lining vs. Chemicals 	   5-40

   7-1          Applicability of Types of Leak Sensors 	   7-11

   7-2          Comparison of Various Leak-Sensing
                 Techniques 	   7-16
                                       xi

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                           LIST  OF  TABLES  (Continued)
Table No.       Title                                             Page
   7-3         General  Characteristics  of  Impermeable
                 Barriers  for  Concrete  Vaults  	   7-42
   9-1         Characteristics of Pneumatic  and  Electronic
                 Controls  	   9-4
   9-2         Level-Detection Devices  for Underground
                 Storage Tanks 	   9-6
   9-3         Transfer Spill-Prevention Systems  	   9-14
   9-4         Level-Detection Devices  for Overfill  Pro-
                 tection Systems  for  Aboveground/Inground/
                 Onground  Storage Tanks 	   9-25
  10-1         Inspection  Requirements  Before  Secondary
                 Containment  is Provided  	   10-4
  10-2         Inspection  Requirements—After  Full  Secondary
                 Containment  is Provided  	   10-5
  11-1         Section  264.196 Required Responses  to Tank
                 System Releases  	   11-12
  12-1         Closure/Post-Closure Requirements  	   12-2
  13-1         Ignition Prevention References  	   13-6
  13-2         Definition  and  Classification For  Tank
                 Contents  by  NFPA 	   13-9
  13-3         Stable Liquids—Operating Pressure  2.5  PSIG
                 or Less 	   13-12
  13-4         Stable Liquids—Operating Pressure  Greater
                 than 2.5  PSIG 	   13-14
  13-5         Boil-Over Liquid	   13-15
  13-6         Unstable Liquids	   13-16
  13-7         Class III B Liquids  	   13-18
  13-8         Reference Table For Use  In  Tables  13-1, 13-3,
                 and 13-4  	   13-19
  13-9         List of  Chemical Classes 	   13-24
                                       xii

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                           LIST OF TABLES (Continued)







Table No.      Title                                              Page



 l'3-10         List of Chemical Representatives by Class  	   13-25



 13-11         Storage Tank Decontamination Methods  	   13-32
                                       xiii

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                                    ACRONYMS

AA            Aluminum Association
ACI           American Concrete Institute
AISI          American Iron and Steel Institute
ANSI          American National Standards Institute
API           American Petroleum Institute
ASME          American Society of Mechanical Engineers
ASTM          American Society for Testing and Materials
AWWA          American Water Works Association
CERCLA        Comprehensive Environmental Response, Compensation, and
              Liability Act of 1980
CFR           Code of Federal  Regulations
DC            direct current
DOE           U.S. Department of Energy
DOT           U.S. Department of Transportation
EPA           U.S. Environmental Protection Agency
FML           Synthetic Flexible Membrane Liner
FR            Federal Register
FRP           Fiberglass Reinforced Plastic
HOPE          High Density Polyethylene
HSWA          Hazardous and Solid Waste Amendments of 1984
kPa           kilo Pascal
NACE          National Association of Corrosion Engineers
NFPA          National Fire Protection Association
NIOSH         National Institute for Occupational  Safety and Health
NTIS          National Technical Information Services
PSD           Prevention of Significant Deterioration (related to air quality)
psi           pounds per square inch
PVC           poly vinyl chloride
RCRA          Resource Conservation and Recovery Act
SI unit       Systems International units
UIC           Underground Injection Control permit
UL            Underwriters Laboratories, Inc.
                                       xiv

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                                             foiicy Uirective No.  9483.00-1
                                EXECUTIVE  SUMMARY

    The final  rule for  Hazardous  Waste  Storage  and  Treatment  Tank  Systems,
published  July 14, 1986,  (effective  date January 12,  1987)  establishes new or
revised tank system standards applicable to accumulation  tank  systems,  interim
status tank  systems,  and  permitted  tank systems.  This  final rule  represents
the Environmental  Protection Agency's  effort  to fulfill  the  mandates of  the
Hazardous and Solid Haste  Amendments  of 1984 (HSWA) and  to  streamline various
regulations that have  proven ineffective or unworkable.

    The  overall  goal  of  the  rule   is  to  protect   human  health  and  the
environment from the  risks  posed by hazardous  waste storage  and  treatment tank
system facilities.   This is to be accomplished through  prevention  of migration
of  hazardous  waste   constituents  to  ground  and  surface  waters  where  such
releases  may present a risk to human health or  the  environment.  A  key element
of  the  overall   strategy  is  the need  to detect releases quickly so  that  an
appropriate response can be made.

    There are  six  key  features of the  Agency's  regulatory  approach.   The  first
feature  pertains   to  maintaining  the  integrity of  the  primary  containment
system.   The final  rule requires that  the primary systems for  new  and existing
tank systems be appropriately  designed  and compatible  with the wastes that are
stored or treated.

    The  second  feature  concerns  proper  installation   of   the  tank  systems.
Under  the  new  rule   an  independent,   qualified  installation   inspector  or
professional engineer  must certify that  a tank  system is  structurally  sound
prior  to  installation   and  that  proper  handling  procedures are adhered  to
during Installation.

    Secondary containment  with  monitoring  to detect   leaks   from  the  primary
containment vessel  is  the  third feature of the regulatory approach and must be

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provided for all  new  hazardous  waste tank systems.   For  existing  tank  systems,
secondary containment with leak  detection will  be phased  in.

    Means for  seeking variances from  secondary containment for  both new  and
existing  tank  systems  are  provided  in  the  regulations  through  either 1)  a
demonstration  that  alternative  design  or operation  will  detect  leaks  and
prevent  the  migration  of any  hazardous  waste  beyond  a  zone of  engineering
control, or 2) a demonstration that  in  the case of an impending  release  there
will be no substantial threat to human  health  or the environment.

    The  fourth  feature  of  the  EPA's  approach  delineates   provisions  for
adequate  responses  to  releases  of  hazardous  wastes.   Under  this  rule,  all
releases   to  the   environment   must   be  reported  to   the   EPA   Regional
Administrator.

    The fifth feature emphasizes proper operation and inspection.

    A final  feature  of  the  rule is  that  all  owners or operators of  hazardous
waste  tank   systems  provide  adequate closure-  and,  if necessary,  post-closure
care.

    The EPA believes  that releases of  hazardous waste from a  tank  system will
be  curtailed  by  requiring  design   and  installation   standards  for  primary
containment structures,  corrosion protection for metal tank  system  components,
secondary containment and  leak  detection, and quick response  in  the  case of a
release from  the  primary  containment structure  or  other spill.  Any  releases
of  hazardous  waste  to  the  environment  that  might occur will  be minimized by
containment and detection and appropriate closure and post-closure care.

    This technical  resource  document is provided to help  owners  and  operators
comply  with  the EPA's  regulations  for  hazardous  waste  storage  and  treatment
tank   systems.    The  13   sections   cover    the   following   topic   areas:
1) Introduction;  2)  Background;  3)   The  Permitting  Process;    4)  Written

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                                       OSWER Policy Directive No.  9483.00-1
Assessment of  Tank. Systems  Integrity;  5)  New Tank Design; 6) New  Tank  System
Installation; 7) Secondary Containment and Detection of  Releases;  8)  Variances
from Secondary  Containment;  9)  Appropriate  Controls  and  Practices  to Prevent
Spills  and  Overflows;  10)  Inspection;   11)  Response  to Leaks  or  Spills  and
Disposition  of  Leaking   or  Unfit-For-Use   Tank  Systems;   12)  Closure  and
Post-Closure Care; and  13)  Special  Requirements for Ignitable or  Reactive  and
Incompatible Wastes.

    The  first  three  sections  provide  an overview of   1) the  content of  the
regulations;  2)   the  historical  development  of  the  regulations;  and  3)  a
summary of the mechanics of the permitting process.

    Section ,4.0,  Written  Assessment  of  Tank  Systems,  delineates   written
assessment requirements  for  existing  as  well  as new tank  systems  and  includes
technical   guidance   on   the    following   areas:    design   standards;   waste
characteristics;   tank   description;    leak   tests,  inspections   and   other
examinations;  internal  inspection details; protection from  vehicular  traffic;
foundations, loads and anchoring; and' protection against  frost heave.
                                                                            *
    Section   5.0,   New   Tank    System   Design,   identifies   the   regulatory
requirements  for  new  tank  system  design  and  includes  guidance   on   what
information  the  general  written  description  in  the Part B application  should
include  in  the  following  areas:   1)  dimensions  and  capacity of  the  tank;  2)
descriptions  of  feed  systems,   safety  cutoff  bypass   systems   and   pressure
controls;  3)  diagram  of  piping  instrumentation  and   process  flow;  and  4)
external   corrosion  protection,  including  corrosion potential  assessment  and
corrosion protection  assessment.

    Section  6.0,  Installation  of  New Tank Systems, offers  technical  guidance
on  proper  installation  handling procedures,  backfilling,   pre-service   tank
testing,   piping  system  installation,  corrosion protection  system installation,
reinstallation of existing tanks, and  certification.

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    Section 7.0, Secondary Containment  Systems  and  Release  Detection,  provides
Information on properties of  secondary containment  systems, design  parameters,
various  structural  options   for   secondary  containment,  liner  requirements,
vault requirements, double-walled  tank requirements,  secondary  containment  for
ancillary equipment, and implementation schedule for existing  tank systems.

    Section  8.0,  Variances  from  Secondary  Containment,  discusses  procedures
for  seeking  either  risk-based  or  technology-based  variances  from  secondary
containment.

    Section  9.0,   Controls   and  Practices  to  Prevent  Spills  and  Overfills,
outlines  generally accepted  devices  and  procedures for  preventing  transfer
spills   and    overfills   in   underground/aboveground/inground/onground   tank
systems.   Some of  the  areas  covered  include:   1)  elements  of  an  overfill
prevention  system,  such  as   level  sensors and  gauges,  high-level  alarms  and
automatic  shutdown  or  flow-diversion  systems;   2) dry disconnect  couplings  or
transfer pipes  and  hoses;  3) redundant valving  and  instrumentation; and 4)  use
of established transfer stations.

    Section 10.0,  Inspections, delineates the inspection requirements  for  tank
systems  under  the   new  rule  and recommends  appropriate  procedures,  tools  and
electro-mechanical  equipment  to be employed in conducting inspections.

    Section 11.0,  Response  to Leaks  or  Spills  and  Disposition  of  Leaking  or
Unfit-for-Use  Tank  Systems,  outlines  the regulatory  requirements  and  provides
technical  guidance  on  response  actions  for  leaks or spills  or  such  tasks  as
waste  flow stoppage,  waste  removal,  visible release containment,  and repair,
replacement,  or closure.

    Section  12.0,   Closure  and  Post-Closure  Requirements,   in  addition   to
Identifying  the regulatory  requirements,  provides  guidance  on  1)  developing
closure/post-closure  plans,  2)  carrying  out   closure  and  post-closure  care
activities,  including  decontamination and  removal  procedures during  closure,
and 3) developing closure and post-closure cost  estimates.

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                                       OSHER Policy Directive Mo.  9483.00-1
    Section 13.0, Special  Requirements  for  Ignitable,  Reactive  or  Incompatible
Wastes,  describes the  information  that  must be provided  in  the Part B  permit
application  for  ignitables,  reactives  or  incompatibles.   In  addition,  this
section  recommends the  general  procedural  precautions  that should be taken  in
the handling,  storage  or  treatment  of  these  wastes, such as establishment  of
protective distances  between  the  storage  or  treatment  tank  and public  ways,
streets  and alleys.

    Appendices   include   information  on  pertinent  EPA  technical   resource
documents,  applicable  technical   documents,   and  tank-specific  definitions.
Also provided  is  a  checklist  (Appendix  A) against which  the  owner  or operator
can verify compliance with the regulatory requirements.

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                                            OSWER Policy Directive No.  9483.00-1

                                         1-1

                                 .0   INTRODUCTION
    This  document   provides  owners  or operators  of  hazardous  waste  storage
tanks guidance in preparing Part B permit  applications  and for the  Federal  and
State officials  who will  be  processing these  applications  required by  Title
40,  Code   of  Federal   Regulations,   Part   270  (40 CFR 270).    Appropriate
references  to other  titles  in  the Code  of Federal  Regulations  are made  to
clarify, where possible,  the  full  intent or scope of  the  regulations.
                               1.1   APPLICABILITY

    Under  these  final  regulations,  tank  systems  storing  or treating  liquid
hazardous waste, non-liquid wastes  (such  as  solid  hazardous wastes,  residues,
dried  sludge,   etc.),  and/or  gaseous  hazardous waste  are  covered  and  must
comply with the requirements in Part 264,  Subpart  J  and Part 270,  unless  they
qualify  for  a  variance.  Certain  tank system  types,  however,   qualify  for an
exemption from  the  secondary containment requirement  (See Table  1-1).
                          1.2   PURPOSE OF THIS DOCUMENT

    Title  40  CFR  270  establishes  the   requirements   of  the   Environmental
Protection  Agency's  (EPA)  permit  program  for  hazardous   waste   management
facilities.  It  stipulates the  information  that the applicant must  submit  in
the  Part 8  permit  application  to  demonstrate  compliance  with  the  minimum
technical  permitting  standards  for hazardous waste  management  facilities  as
contained  in  40   CFR   264.    Section   270.16  speci'f ical ly  stipulates   the
information  that the  owners  or  operators  of  hazardous  waste  storage  and
treatment tank systems must  submit in a Part B  permit  application.   Title  40
CFR  264.190-199  (Subpart 0)  stipulates  minimum  technical  permitting  standards
specifically for  hazardous waste storage and treatment tank systems.

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                                    1-2
                               TABLE 1-1
                     EXEMPTIONS FROM 40 CFR 264.193'
         Type of Tank System
                                             Exemption  from Section
(1)  Indoor with impervious floor
     containing no free liquids
     (Sec. 264.190
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                                            OSHER Policy Directive No.  9483.00-1

                                         1-3

    Owners  or  operators  of  existing  and  new  hazardous  waste  storage  and
treatment  tank,  systems  are  required  to  submit  Part  B  of  their  permit
applications   to   illustrate  compliance  with   the   tank   system  permitting
standards.  If  you  are  currently operating an  existing  facility  under interim
status  (40  CFR  265),  you  will   have  submitted  Part  A  of your  application.
Owners or operators of new facilities must submit Parts A and B together.

    This  document  provides  assistance  to  owners or  operators  of  hazardous
waste  tank  systems on preparing  a  complete  Part B permit  application  (40 CFR
270)   to  demonstrate   compliance   with   the  applicable   general   permitting
standards (40  CFR  264) as  well  as  the  tank-specific  permitting  standards (40
CFR 264, Subpart J).  (See Section 3.0 of this document for  further  details  on
the  permitting process and Table  3-1  for  clarification of  the  relationship
between Parts 264 and 270.)
                     1.3  SPECIFIC INFORMATION REQUIREMENTS

    The  specific  Part   B   information   requirements  for  tank  systems  are
contained in 40 CFR Z70.16,  as revised July  14,  1986, and are  the  major  focus
of this document:

    (a)  A  written  assessment  that  is  reviewed  and  certified  by  an
         independent, qualified,  registered  professional  engineer  as  to
         the structural   integrity  and  suitability  of  each tank system for
         handling the hazardous waste each holds;

    (b)  Description of  the  dimensions and capacity of each tank;

    (c)  Description of  feed systems, safety cutoffs,   bypass  systems,  and
         pressure controls;

    (d)  A  diagram  of piping,  instrumentation, and process flow for  each
         tank system;

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                                           OSWER  Policy Directive No. 9433.00-1

                                        1-4

    (e)   A description  of  the  materials  and  equipment  used  to provide
         external  corrosion protection;

    (f)   For  new  tank  systems,  a  detailed description of how  the  tank
         system(s) will  be Installed;

    (g)   Detailed  plans  and description  of how the  secondary  containment
         for  each  tank  system  is  or  will be  designed,  constructed, and
         operated;

    (h)   For   tank  systems  for  which   a variance   from  the  secondary
         containment  requirements  is   sought:   (1)   detailed   plans and
         engineering   and   hydrogeologic   reports,   as    appropriate,  -
         describing alternate design  and  operating  practices  that  will,
         in conjunction  with location aspects,  prevent  the migration  of
         any  hazardous  waste or  hazardous  constituents   into  the  ground
         water or surface  water  during  the life  of the facility,  or (2) a
         detailed   assessment of   the  substantial  present  or  potential
         hazards  posed   to  human  health or  the  environment  should   a
         release  enter   the  environment  (a   detailed   discussion   of
         variances  from  secondary containment is  being  developed  by EPA
         and  should be available in early 1987);

    (i)   Description of  controls  and   practices   to  prevent  spills and
         overflows;  and

    (j)   For  tank  systems  In which  ignitable,  reactive,   or  incompatible
         wastes  are  to   be  stored  or   treated,   a   description   of  how
         operating  procedures  and  tank   system  and  facility  design  will
         achieve compliance with the special  requirements  for  those types
         of wastes.

    In   addition,   this   document  provides   information  on   procedures   for
inspection,    unfit-for-use    tank    system     corrective     action,    and
closure/post-closure  care,  as   required  under   Part  B   General  Information

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                                            OSWER Policy Directive No.  9483.00-1

                                         1-5

Requirements  270.14(b)"(5),   (7),  and  (13).   For each  of  these areas,  this
document presents:  (1)  the  applicable regulatory citations;  (2) guidance  on
meeting the  information  requirements  and  referenced  standards;  (3) examples  of
suitable application information;  and  (4)  major points to  address  in  preparing
or reviewing the permit application.

    Permit  applicants  must  note  that  the 40  CFR 270.16  specific  information
requirements for hazardous waste  tank  system are  only  a  tank  system-specific
supplement  to  the  40  CFR 270.14(b)  general  permit   information  requirements.
Ultimately  the  270.14(b) general  information  requirements  must  be  submitted
jointly  with  the  information  specific   to  tank  systems  (40  CFR 270.16)  to
complete Part B permit  applications.

    This  document  also  gives  introductory  and background  information  to
provide  a  better  understanding  of  the  overall  regulations  and  permitting
process.   If  the  permit  application  is  prepared   in  conformance  with  the
specific  guidance   presented   for  Sec.  270.16  and   in  conformance  with  the
entirety of  the  general  information  requirements for Sec. 270.14(b),  it  will,
at a minimum,  allow  expeditious review by the  EPA, and  its likelihood  of being
approved should markedly improve.
                       1.4  ORGANIZATION OF THIS DOCUMENT

    Introductory Sections  2.0 and  3.0  explain the background of  the  Resource
Conservation  and  Recovery   Act   (RCRA)   Subtitle  C   (the  Hazardous   Waste
Management Subtitle of RCRA),  the specific status of Subtitle C  rulemaking for
tanks,  the  RCRA permitting  process  employed by  the  EPA, and  an  overview  of
40 CFR Parts  270  and  264.    Sections   4.0-13.0  are  divided  in  to  several
sub-sections for  each of  the  major topic  areas  within a  section.   Each  of
these  Individual  sub-sections  has  a   corresponding   citation   and  guidance
section.  The citation provided in the  citation section  is in most  cases  taken
verbatim  from  the  federal register.   The reader  should  be  informed,  however,
that  in  some  instances  the citation is paraphrased  or  abbreviated.   This  has
been done for either clarity sake or to conserve space.

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                                            OSWER Policy Directive No.  9483.00-1

                                         1-6

                           1.5   OTHER GUIDANCE MANUALS

    Other guidance manuals  exist  or are in preparation  and  will  be of  use  in
preparing  the  overall  Part B  permit   application.   This  document will  note
throughout when  other guidance manuals  would   be  particularly  useful   and  in
what  sections  of those  manuals the pertinent  information  can  be  found.   For
instance,  the  "Permit Applicant's  Guidance Manual  for  the  General  Facility
Standards" will  be  a  useful  tool  for  complying with  the  general  information
requirements   "  i  Part  B  permit  application.   In  addition,   EPA  will  soon
publish   "Technical   Resource   Document  for  Obtaining  Variances   from  the
Secondary Containmer:  Requirement  for  Hazardous  Waste Tank Systems",  which  is
intended  to  provide  technical   assistance and information  for owners/operators
of  hazardous  waste  tank,  systems   applying  for   either  a  technology  based  or
risk-based variance from the secondary  containment requirements.

    Appendices A and  B provide a  list  of other  pertinent technical documents,
locations  where  they can  be  reviewed  or purchased,   and  synopses  of  the
documents.   It  is  recommended  that the permit  applicant  become familiar with
the available  literature  because,  in  total, this body  of information  will  be
of  great  assistance   in  preparing  a   permit   application  acceptable   to  the
Federal and State regulatory agencies.

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                                            OSHER Policy Directive No.  9483.00-1

                                         2-1

                                 2.0   BACKGROUND
    In 1976, Congress  passed  the Resource Conservation and Recovery Act (RCRA)
to regulate the  handling  and  disposal  of hazardous  waste.   This  act  mandated
the development  of regulations  governing  the actions  of  owners  or  operators
who generate,  transport, treat, store,  or dispose of hazardous wastes.

    The complete text  of  RCRA and its associated amendments  are too  long  for
inclusion  in   this  document,  but  Table  2-1  provides  a  list  of the  major
sections.   Available  sources  for copies  of  this  act  and   related  laws  are
listed at the  bottom of Table  2-1, p.  2-2.

    RCRA,  as   amended   by  the  Quiet  Communities  Act  of  1978,  the  Used  Oil
Recycling Act of 1980,  and the  Solid  Waste Disposal  Act  Amendments  of  1980,
is, itself, an amendment  to  Title II  of the Solid Waste Disposal  Act.   RCRA
was again  amended  on  November 8, 1984,  when the  Hazardous  and  Solid  Waste
Amendments (HSWA) of 1984 were signed  into law.

             2.1   STATUS  OF SUBTITLE C—HAZARDOUS WASTE  MANAGEMENT

    Hazardous   and   Solid  Waste  Amendments,   "Subtitle  C—Hazardous  Waste
Management," as  amended,   contains several  sections which  serve as  the  basis
for the  development  of  the  hazardous  waste  regulations promulgated by  the
Environmental  Protection Agency  (EPA).   Subtitle  C  states  what  EPA must  do to
govern  hazardous  waste  handling  and  disposal   and   provides   EPA  with  the
authority to carry out the provisions  of the Act.

                 2.2  STATUS OF SUBTITLE C RULEMAKING FOR TANKS

    The EPA promulgated  interim status  standards  for  hazardous  waste  storage
and treatment  tanks  in May 1980 under Part 265,  Subpart J  (45 FR 33244-33245).
These  standards emphasized the appropriate operating procedures  for preventing
hazardous waste releases from tanks.

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                                        2-2

                                   TABLE 2-1
                      RESOURCE  CONSERVATION &  RECOVERY ACT
                                (NOVEMBER  1984)
"Sec.  3001.    Identification  and  listing  of hazardous  waste
"Sec.  3002.    Standards  applicable  to generators  of  hazardous  waste
"Sec.  3003.    Standards  applicable  to transporters of  hazardous  waste
"Sec.  3004.    Standards  applicable  to owners  and operators of  hazardous  waste
              treatment,  storage,  and disposal  facilities
"Sec.  3005.    Permits for  treatment, storage,  or  disposal  of hazardous  waste
"Sec.  3006.    Authorized State hazardous  waste programs
"Sec.  3007.    Inspections
"Sec.  3008.    Federal enforcement
"Sec.  3009.    Retention  of State  authority
"Sec.  3010.    Effective  date
"Sec.  3011.    Authorization of assistance to States
"Sec.  3012.    Hazardous  waste site  inventory
"Sec.  3013.    Monitoring,  analysis, and testing
"Sec.  3014.    Restrictions on recycled oil
"Sec.  3015.    Expansion  during interim status
"Sec.  3016.    Inventory  of federal  agency hazardous  waste facilities
"Sec.  3017.    Export of  hazardous waste
"Sec.  3018.    Domestic sewage
"Sec.  3019.    Exposure Information and health  assessments
NOTE:Copies of  RCRA,  as  currently amended,  may  be  obtained  through  USEPA
         Publications  Department,   Public  Information  Center,   820  Quincy
         Street, NW, Washington,  DC  20001; telephone 800-828-4445.
Source:  Resource Conservation and Recovery Act,  PL98-616,  Nov.  8,  1984.   SNA,
         Environment Reporter, Dec. 28, 1984,  71:3101.

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                                            OSHER Policy Directive No.  9483.00-1

                                         2-3

    In January  1981,  RCRA permitting standards were  promulgated  for  hazardous
waste  storage  and  treatment  tanks  that  could   be  entered  for  inspection.
(Underground  tanks  that  could not  be  entered  for   inspection were  precluded
from  obtaining  a  RCRA permit.)   These  standards  emphasized  the  structural
integrity  of   tanks   to   protect  against  leaks,   ruptures,  or   collapses.
Requirements included:

    1)   adequate tank design;
    2)   maintenance of minimum shell thickness;
    3)   routine inspection schedules;  and
    4)   specific requirements for  ignitable,  reactive,  and  incompatible
         wastes.

    On July  14,  1986,, Part  264  hazardous  waste  treatment  and storage  tank
permitting standards were  revised (51 FR 25422).   These  recent  revisions  serve
many purposes.   As  stated  in  the preamble  to the June,  1985 Proposal  50 FR
26444 (in which  were proposed new regulations for hazardous waste  tank systems
that  affect  40  CFR  Parts  264,   265,  and  270),  they  fulfill the  regulatory
approach  for tanks  described  in  the January 1981  Preamble by:   (1)  providing
permitting  standards   under  Part  264  for  underground  tanks  that  cannot  be
entered for  inspection; (2)  stipulating corrosion protection  requirements  for
metal  tank  systems;   and  (3)  specifying  the   selection of  an  appropriate
secondary  containment  approach.    These  revisions   also  complied   with  the
mandates  of  the  HSWA  amendments  stipulating that new underground  tank systems
had  to be  equipped  with  leak-detection  systems  [RCRA Section  3004(o)<4)]  and
that  the  EPA  had  to  issue  permitting  standards  for underground tanks  which
cannot be  entered  for  inspection  [RCRA Section  3004(w)].   Also,  additional
revisions and  requirements were  warranted  as  certain  existing  tank  standards
had proven incomplete, unworkable, or both.

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                                            OSWER Policy Directive  No.  9483.00-1

                                         3-1

                           3.0   THE PERMITTING PROCESS
    Two parts of  Title  40 of the Code of  Federal  Regulations  (40 CFR)  contain
information on  the  Resource Conservation  and Recovery Act  (RCRA)  permitting
process.    Part   270  contains   information   on   what  an   applicant  and  the
Environmental  Protection Agency  (EPA)  must do regarding a  permit.  This  part
also   contains   basic  permitting   requirements   for  EPA-administered   RCRA
programs,   such  as  application  requirements,  standard  permitting  conditions,
and monitoring and  reporting  requirements.   Part  124  establishes  the decision-
making procedures  for EPA  issuance  of  RCRA  permits  and   the  procedures  for
administrative appeals of EPA permit  decisions.

    As  mentioned   1n  Section   1.0   of  this  document,   separate   technical
permitting regulations are also  stipulated  in 40 CFR,  Part  264, in addition  to
the  requirements  in  Part 270.    The  Part  264 regulations  "establish  minimum
federal standards for acceptable  management  of hazardous waste.   The  text  of
Part  270   refers  the reader  to  the  sections of Part  264  that contain  the
standards   with  which  -a  permit  applicant   must  demonstrate  compliance  by
submitting  information   in  Part  B   of  a  permit  application.   To  assist  the
applicant, Sections 4.0-13.0 of  this  document  address the required information
items  as  set  forth  in  Part  270,  identify  the corresponding standards  in  Part
264,   and  provide   information   on   how  to  obtain,  prepare,   and   present
information required  by Part 270 that  will  demonstrate  to  the  EPA that  the
facility  is in  compliance  with  the  Part 254  standards.   Table 3-1  delineates
the  270.16   specific   Information   requirements   and  the   corresponding  264
permitting standards applicable  to hazardous  waste tanks.

    As noted,  applicants should  use  the  guidance  on procedures and  methods  in
Sections  4.0-13.0  to prepare  those  parts   of   the  Part   8 application  that
support  the   specific Information  requirements   of  270.16  and   the  general
information requirements  1n  270.14(b)(5),  (7), and (13).    In addition  to the
information requirements  addressed  in  this  document,  applicants  must  also
comply  with   the   entirety   of   the  270.14(b)   Part  B  General  Information
requirements.

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                                           OSHER Policy Directive No. 9483.00-1
                                        3-2
                                   TABLE 3-1

         SECTION OF 40 CFR PARTS 270  AND 264 ADDRESSED  IN THIS DOCUMENT
Document
Sections
Part 270
Sections
                                                     Corresponding
                                                     264 Sections
   4.0
   5.0

   5.1

   5.2

   5.3


   5.4


   6.0

   7.0


   8.0



   9.0


  10.0

  11.0


  12.0

  13.0
270.16U)
270.16(5)

270.16(c)

270.16(d)


270.16(e)


270.16(f)

270.16(g)


270.16(h)



270.16(1)


270.14(6)(5)

270.14(5)(7)


270.14(5X13)

270.16(j)
Written assessment of structural
Integrity reviewed and certified
by an  independent, registered
professional engineer for:
"Existing" tank systems
"New"  tank systems

Tank design features

Tank dimensions and capacity

Description of feed systems

Diagram of piping, Instrumen-
tation, and process flow

Description of materials and
equipment for corrosion protection

New  tank  installation description

Secondary containment system plans


Information submittal for  tanks
for  which a variance from  second-
ary  containment is sought

Spills and overfill prevention
•practices

Inspection schedules

Response  to unfit-for-use  tank
systems

Closure and post-closure plans

Procedures for tank systems that
store  or  treat ignitable or incom-
patible wastes
                                                              264.191(aXb)(c)(d>
                                                              264.192(a)
                                                   None

                                                   None

                                                   None


                                                   264.192(a)(3)


                                                   264.192(5Xc)(dXe~)

                                                   264.193(aX5XcXd>
                                                   (eXf)

                                                   264.193(g)



                                                   264.194(b)


                                                   264.195


                                                   264.196

                                                   264.197

                                                   264.198  and
                                                   264.199
NOTE:  Regulatory   standards   264.195,   264.196,  and  264.197,  as   revised,
       correspond  to  the  270.14(b)  Part  B   General   Facility   Information
       Requirements.   They  are  not  addressed  in  the  270.16 revised  specific
       Part B information requirements for tanks.

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                                            OSWER Policy Directive No.  9483.00-1

                                         3-3

    The addresses and  telephone  numbers  of the various  EPA  Regional  Hazardous
Waste Program Offices  are listed  in  Table 3-2.   In  addition,  appendices  are
included at the  end  of the document to provide supplementary information, such
as names and addresses  of state  and federal  regulatory  agencies  and  locations
where  the  permit applicant  can  request  pertinent documentation,  reports,  and
maps.  Information of a more technical  nature  is also included  in  Appendices A
and  B.    (For  further  information  on  the  overall  steps  in the  permitting
process,  logistics   on  permit  application  submissions,  confidentiality  and
appeal   procedure  information,   see  "Permit   Applicant's  Technical   Resource
Document for the General Facility Standards of 40 CFR  264.")

                              3.1   PERMITTING STEPS

    This  section of  the   document  presents  a  simplified  description  of  the
major steps that  must  be  taken  by  both  an applicant  and by the EPA during the
RCRA permitting  procedure.   It  also  identifies  those Parts  of Title  40 that
are important to an  owner  or operator seeking  a RCRA  permit.

    The overall  RCRA  permitting  process  can  be  summarized  in  the  following
steps:

    Step 1    The owner  or  operator  of  a   hazardous   waste  management
              facility  (in this  case,  tank  systems  that store or  treat
              hazardous waste) completes Parts  A  and  B  of a  RCRA  permit
              application   and  submits  the application  to the appropriate
              EPA office.

    Step 2    The  EPA  reviews   the  application  for  completeness.    If
              incomplete,   the  EPA  sends   a   list  of   deficiencies,   in
              writing,   to  the  applicant.  If  complete,   the  applicant  is
              informed  In  writing.

    Step 3    When  necessary,  the  applicant   prepares   and   submits  the
              additional information requested.

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                                                                   f»O.
                                                                           . UU- I
                                        3-4


                                   TABLE 3-2

                  EPA REGIONAL HAZARDOUS HASTE PROGRAM OFFICES
Region I:     OFFICE OF THE DIRECTOR
              State Waste Programs Branch
              Waste Management Division
              John F. Kennedy Federal  Building
              Boston, MA  02203
              (617) 223-6883

Region II:    OFFICE OF THE DIRECTOR
              Sol id Waste Branch
              Air  and Waste Management Division
              26 Federal Plaza
              New  York, NY  10278
              (212) 264-0505

Region III:   OFFICE OF THE DIRECTOR
              Waste Management Branch/RCRA Permit Section
              Air  and Waste Management Division
              841  Chestnut Street
              Philadelphia, PA  19107
              (215) 597-0980
                                             •
Region IV:    OFFICE OF THE DIRECTOR
              Residuals Management Branch/Waste Engineering Section
              Air  and Waste Management Division
              345  Cortland Street, NE
              Atlanta, GA  30365
              (404) 347-3067

Region V:     OFFICE OF THE DIRECTOR
              Waste Management Branch
              Waste Management Division
              Federal Building
              230  Dearborn
              Chicago, IL  60604
              (312) 886-7579

Region VI:    OFFICE OF THE DIRECTOR
              Hazardous Materials Branch
              Air  and Waste Management Division
              First International Building
              1201 Elm Street
              Dallas, TX  75270
              (214) 767-2730
Continued on next page.

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                                            OSHER Policy Directive No.  9483.00-1


                                         3-5


                              TABLE 3-2—Continued
Region VII:    OFFICE OF THE DIRECTOR
              Waste Management Branch
              Air and Waste Management Division
              726 Minnesota Avenue
              Kansas City, KN  66101
              (913) 236-2888

Region VIII:   OFFICE OF THE DIRECTOR
              Waste Management Division
              RCRA Management Branch
              Suite 900, 1860 Lincoln Street
              Denver, CO  70295
              (303) 293-1662

Region IX:     OFFICE OF THE DIRECTOR
              Programs Branch
              Toxics and Waste Management Division
              215 Frejnont Street
              San Francisco, CA  94105
              (415) 974-8119
                                              •
Region X:      OFFICE OF THE DIRECTOR
              RCRA Branch
              Air and Waste Management Division
              1200 6th Avenue
              Seattle, WA  98101
              (206) 442-2851

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                                        3-6

    Step 4    The  EPA  again  reviews   the  original  and  the  additional
              submittals and notifies  the  applicant,  in  writing,  of  the
              completeness  of the application.

    Step 5    The   EPA   analyzes   the   Information   contained  in   the
              application and prepares  a draft  permit  or issues a  notice
              of Intent  to  deny  the  application.   In either  case,  the  EPA
              simultaneously prepares and issues a  statement of basis  or
              a fact sheet.

    Step 6    The EPA sends  copies  of  the  document prepared  in  Step  5 to
              the applicant,  and  simultaneously  makes  a  public  notice
              that  a  permit  application  has  been  prepared.   The  public
              notice  will  provide  45   days  for  public  (and  applicant)
              comment.

    Step 7    If, at  the time  of public notice, or at  any time during  the
              45-day comment period, anyone,  including the  EPA,  requests
              a  public  hearing,  one will  be   scheduled  and  announced  a
              minimum of 30 days before the  hearing date.

    Step 8    The EPA prepares and issues  a  final  permit decision.

These  eight  steps   are  a simplified description.   A full description of  the
steps  that   the  EPA  must  take  after   receiving  a  complete  RCRA  permit
application  Is  contained  in 40  CFR  Subpart  A of Part  124  in  Sees.  124.3
through 124.21.

                   3.2  THE PERMIT APPLICATION  AND  THE  PERMIT

    The  RCRA  permit  application  consists   of  two  parts:  Part  A,  a  form
requiring completion, and Part B, which has  no  standard format.   This  document
is designed  to  assist applicants in preparing  the  information required in  Part
B of a RCRA permit application.

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                                            OSHER Policy Directive No.  9483.00-1

                                         3-7

    Part 270  of Title  40 of  the CFR  provides  the  information  requirements
necessary for a  complete  RCRA  permit application (Parts A  and  B).   All  of the
sections of Subpart B of Part 270 should be read and understood by  an  owner  or
operator who is  applying for a  RCRA permit for the first time.

    The  actual   permit  will  consist  of  written  approval  of  the  complete
application.  It will  require  the applicant to adhere  to  all   statements  made
in  the  application  and will  Include  conditions that  must be complied  with.
Applicants   interested  in  the types  of  conditions  that  may  be  contained  in  a
permit  are  referred to Sec.  270.30 ("Conditions Applicable to  All  Permits")
and Sec. 270.32  ("Establishing  Permit Conditions").

                        3.3   WHERE TO SUBMIT APPLICATIONS

    Table 3-2 lists the mailing  addresses  and the telephone numbers of  the  10
EPA regional  offices  where  permit applications  should  be  submitted.    Person-
nel in these offices may be  contacted with any questions that may arise  during
preparation of a permit application.

    Many states  have  their  own  hazardous waste  permitting programs.   These
programs may  be in  addition  to or  in  lieu  of the  EPA  RCRA  program.   Any
applicant who is unsure of  which agency  an application  should  be submitted  to
should contact the  nearest regional  EPA office (Table  3-2)  for  clarification.

                              3.4  CONFIDENTIALITY

    If applicants  find  it necessary,  or are  required,  to  include confidential
Information 1n  an  application,  they  should refer to Sec.  270.12  ("Confidenti-
ality of Information")  in Subpart B of Part  270.   Of  particular  note are  the
items in Sec. 270.12(b) that cannot be claimed as confidential.

    To assert a  confidentiality  claim,  the provisions  of 40 CFR 270.12 require
that the applicant  attach  a cover  sheet, or  stamp or  type a  notice on  each
page of the  information,  or  otherwise  identify  the confidential  portion(s)  of

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                                        3-8

the   application.    Words   like   "trade   secret,"   "confidential   business
information," "proprietary," or  "company confidential"  should be  used.   The
notice  should also  state  whether the applicant desires  confidential  treatment
only until a certain date  or a  certain event.

    Whenever possible,  the applicant should separate the  information  contained
1n  the  application  into  confidential  and  non-confidential  units and  submit
them  under   separate  cover  letters.    Claiming  confidentiality  for  a  large
portion of  the  permit  application  and failing to  separate it into confidential
and non-confidential  units  may  result  in a  significant  delay   in  processing
because the  EPA lacks  the  in-house resources for expeditiously  isolating  the
c'." ~ idential from the non-confidential information.

    If it 1s necessary  to send confidential  information  through  the  mail,  the
applicant  should  consider  the  following  precautions   in  addition   to  those
listed in Sec.  270.12:

    1.   Place   the  material   in  a  sealed   envelope   or  container  and
         conspicuously  mark   the   envelope   or   container  "confidential
         information."

    2.   Place  the  sealed,  marked  envelope or container  inside  an outer
         envelope or  container that is properly addressed  but  not marked
         as  confidential, and  seal this outer envelope  or container.

    3.   Mail (or  otherwise ship)  the  material  with return receipt  (or
         equivalent) requested.

    The  EPA is   not liable  for  release of  information  that an  applicant  has
submitted but failed  to identify as confidential.  (Additional  information  on
the EPA's handling  of  confidential information can be  found in Part 2 of Title
40 of the CFR.)

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                                            OSWER Policy Directive  No.  9483.00-1

                                         3-9

                                  3.5  APPEALS

    It  is   possible  to  appeal  the  contents of  a  final   RCRA  permit.   The
procedure for petitioning the EPA to review any condition of a  permit  decision
is contained  in  40 CFR  Sec.  124.19  ("Appeal  of  RCRA, UIC,   and PSD  Permits").
In addition, EPA  can  decide on its  own  initiative to  review  a final  permit.
In either  case,  a petition or decision  to  review  a  final  permit must  be  made
within 30  days  after a  RCRA final  permit  decision  has been  made under  Sec.
124.15.

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                                            OSHER Policy Directive No.  9483.00-1

                                        4-1

                    4.0   WRITTEN ASSESSMENT OF TANK SYSTEMS
     This chapter  provides  guidance  on preparing the  information  required  for
a tank system assessment report and on  the  procedures  to be used  to  make  tank
system assessments.   It presents  information  and guidance for  evaluating  the
technical performance of tank systems.

     Section  264.191,  "Assessment  of  existing  tank   system's   integrity,"
requires   that  for  each  existing  tank  system  that  does  not  have  secondary
containment  which  meets  the  requirements  of  Sec.   264.193,   the  owner   or
operator  must obtain  and  keep  on file at  the  facility a written assessment of
the tank  system's  integrity (i.e.,  that  the  tank  is  not  leaking and  i s' not
unfit  for  use).   The  assessment  must   be  reviewed  and  certified  by   an
independent,  qualified,  registered  professional  engineer.   An  "independent"
engineer   is  one who  is not  on  the facility's  staff.   This assessment  must be
complete  and be on  file by January  12,  1988.

     Section  264.192,  "Design  and   Installation  of  New  Tank   Systems   or
Components," requires  that  owners  and  operators  of new  tank  systems  submit to
the Environmental  Protection Agency's   (EPA) Regional  Administrator  a  written
assessment  of  the   system's  structural  integrity  and  acceptability  for  the
storage and  treatment  of  hazardous  waste.   The  assessment may  be written  by
any qualified  person, whether or  not a registered professional  engineer,  but
it must  be  reviewed  and certified  by  a an independent,  qualified,  registered
professional  engineer.    A  professional   engineer   should   come   from   the
disciplines of  civil,  structural,  geotechnical,  or mechanical  engineering  and
have  both  training  and experience  in tank  system  design and  installation.
More than one engineer may  be  required to ensure that  design  and  installation
experience  are  both  included.   It  should  be noted that each state controls  the
registration of  professional  engineers practicing within its borders.   Thus,
it  is important  that the  engineer  selected  by  the  tank  system  owner  or
operator  be registered to practice  in the  state in which the system is  or  will

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                                           OSHER  Policy  Directive  No.  9483.00-1

                                        4-2

be installed.  In most  states,  registered  professional  engineers are  required
to stamp or  seal  the  certification  documents they provide and  are  responsible
for such certifications.

     At a minimum,  the  independent,  registered professional  engineer must  be
qualified to  assess a  tank  system's  structural  Integrity and usual  causes  of
failure.  The  individual  must  be  able  to  recognize,  typically  from  field
experience,   the  signs  of  past or  Imminent  tank  system failure.   Such  signs
include problems with piping  and  other ancillary  equipment   (e.g.,  inadequate
seals or  valves),   residues around  a  tank from  overfills and/or  leakage,  and
corrosion of  tank  system  metal.   Because   the   assessment  must  contain  a
certification of acceptability  for  storing  hazardous  wastes, the engineer must
also  be able  to assess  and  Interpret  information  on  the  hazardous  waste
contents of  the  tank  system  and their  compatibility  with the  construction
materials of the tank and lining.

                      4.1  TANK SYSTEM DESIGN AND  TESTING

     Citations

     The  written  assessment  of   a  tank   system,  required  for  a  Resource
Conservation and  Recovery  Act  
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                                            OSWER  Policy Directive No.  9483.00-1


                                        4-3


          certified  by an  independent,  qualified registered  professional
          engineer,  in accordance  with  Sec.  270.11(d),  that  attests  to
          the tank system's  integrity  by .January  12,  1988.
     (b)   This  assessment   must  determine   that  the   tank   system   is
          adequately  designed and  has sufficient structural  strength  and
          compatibility  with the  waste(s)  to be  stored  or  treated,  to
          ensure  that  it  will   not  collapse,  rupture, or  fail.   At  a
          minimum, this assessment  must consider the  following:
          (1)  Design  standard(s),  if available,  according  to which  the
               tank, and ancillary  equipment  were constructed;
          (2)  Hazardous  characteristics  of the   waste(s)  that have  been
               and will be handled;
          (3)  Existing corrosion  protection measures;
          (4)  Documented   age   of   the    tank   system,    if  available
               (otherwise, an estimate of  the  age); and
          (5)  Results of a  leak test, internal  inspection,  or other  tank
               integrity examination such  that:
               (i) For  non-enterable  underground tanks,  the assessment
                   must  include  a leak  test that  is  capable of  taking  .
                   into  account  the  effects  of  temperature  variations,
                   tank  end  deflection,  vapor  pockets,  and high  water
                   table effects,  and
               (ii) For  other   than  non-enterable underground  tanks  and
                   for ancillary  equipment, this assessment  must  include
                   either  a  leak  test,   as   described  above,  or  other
                   integrity   examination,   that  is   certified   by   an
                   independent,   qualified,    registered    professional
                   engineer   in  accordance  with Sec.  270.ll(d),   that
                   addresses cracks,  leaks, corrosion,  and  erosion.
               [Note.-The  practices described  in  the  American Petroleum
               Institute   (API)   Publication,   Guide  for   Inspection  of
               Refinery   Equipment,   Chapter   XIII,   "Atmospheric    and
               Low-Pressure  Storage   Tanks,"  4th  edition,  1981,  may  be
               used,  where  applicable, as guidelines  in conducting  other
               than a  leak test. ]
     (c)   Tank  systems   that   store  or   treat   materials    that   become
          hazardous wastes  subsequent to  July  14,  1986, must  conduct this
          assessment  within  12  months  after the  date  that  the   waste
          becomes  a hazardous waste.
     (d)   If, as  a result of  the  assessment conducted in accordance  with
          paragraph  (a),  a  tank system is  found to  be leaking or  unfit
          for   use,   the  owner  or  operator   must  comply  with   the
          requirements of Sec.  264.196.

     The    owner  or   operator   assessing   the   structural   integrity   and

acceptability of  a  new  tank  system  or   components  for storing  and  treating

hazardous  waste must  document  the  following information,  as  stated  in  Sec.

264.192(a):

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                                 OSw£R  Policy  Directive  No.  9485.00-1


                              4-4
<1)  Design  standards)  according  to which  tank(s) and/or  the
     ancillary equipment are  constructed;
(2)  Hazard characteristics of the  waste(s)  to  be  handled;
(3)  For new  tank systems or components  in  which  the  external
     shell  of  a  metal  tank  or any external metal  component  of
     the tank  system  will be in contact with  the  soil  or  with
     water, a determination by a corrosion expert  of:
     (i)   Factors  affecting   the   potential   -for   corrosion,
           including but not  limited  to:
           (A) Soil  moisture  content;
           (B) Soil  pH;
           (C) Soil  sulfides  level;
           (D) Soil  resistivity;
           (E) Structure to  soil potential;
           (F) Influence of  nearby underground  metal  structures
               (e.g.,  piping);
           (G) Existence of  stray electric current;
           (H) Existing   corrosion-protection   measures   (e.g.,
               coating,  cathodic protection),  and
     (ii)  The type  and  degree  of external  corrosion  protection
           that are needed to ensure the integrity of  the  tank
           system  during  the   use  of  the   tank   system   or
           component,    consisting   of   one  or  more  of   the
           following:
           (A) Corrosion-resistant  materials   of  construction
               such   as   special  alloys,  fiberglass  reinforced
               plastic,  etc.;
           (8) Corrosion-resistant  coating   (such   as   epoxy,
               fiberglass,    etc.)    with   cathodic   protection
               (e.g.,  impressed  current or  sacrificial  anodes);
               and
           (C) Electrical isolation  devices  such as  insulating
               joints, flanges, etc.
           [Note.—The  practices  described   in   the   National
           Association  of Corrosion  Engineers  (NACE)  standard,
           "Recommended     Practice    (RP-02-85)--Control     of
           External   Corrosion  on  Metallic  Buried,   Partially
           Buried,  or  Submerged  Liquid  Storage  Systems,"  and
           the American Petroleum  Institute   (API)  Publication
           1632,   "Cathodic Protection  of Underground  Petroleum
           Storage  Tanks  and  Piping   Systems,"  may  be  used,
           where   applicable,   as   guidelines   in   providing
           corrosion protection for tank systems.]
(4)  For underground  tank system components  that are  likely  to
     be    adversely   affected   by    vehicular    traffic,    a
     determination of design or operational  measures  that  will
     protect  the  tank system against potential  damage; and
(5)  Design considerations to ensure that:
     (i)   Tank foundations  will  maintain  the  load  of a  full
           tank;

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                                       OSHER  Policy  Directive  No".  9483.00-1


                                   4-5


          (ii)   Tank systems  will  be anchored  to  prevent  flotation
                or dislodgment where  the  tank  system is placed  in  a
                saturated zone,  or is located within a  seismic  fault
                zone subject to  the  standards of Sec.  264.18(a);  and
          (iii)  Tank systems  will withstand  the  effects  of  frost
                heave.
(b)   The owner  or operator of  a  new  tank  system   must  ensure  that
     proper handling procedures  are  adhered to in order  to  prevent
     damage to  the  system during installation.   Prior to  covering,
     enclosing,  or placing a  new  tank system or component  in  use,  an
     independent,    qualified    installation    inspector    or    an
     independent,    qualified,   registered   professional    engineer,
     either  of   whom   is  trained and   experienced  in   the   proper
     installation  of tank systems or  component [sic], must  inspect
     the system  for the presence of any  of the  following  items:
     (1)  Weld  breaks;
     (2)  Punctures;
     (3)  Scrapes  of protective  coatings;
     (4)  Cracks;
     (5)  Corrosion;
     (6)  Other    structural   damage   or   inadequate   construction/
          installation.
     All discrepancies  must  be  remedied  before the  tank  system  is
     covered,  enclosed, or placed  in  use.
(c)   New tank systems  or  components  that are placed underground  and
     that  are backfilled must be provided  with a  backfill  material
     that  is a  noncorrosive,  porous,  homogeneous- Substance and  that
     is  installed  so   that  the  backfill   is placed  completely around
     the tank and  compacted  to  ensure that the  tank  and  piping  are
     fully and  uniformly supported.
(d)   All  new  tanks  and  ancillary   equipment   must  be   tested   for
     tightness   prior to being covered,  enclosed,  or placed  in  use.
     If  a  tank  system  is  found  not  to   be   tight,   all   repairs
     necessary   to  remedy  the  leak(s)  in the  system  must  be performed
     prior  to the tank  system  being  covered,   enclosed,  or  placed
     into use.
(e)   Ancillary   equipment  must  be supported  and  protected  against
     physical    damage   and  excessive  stress   due   to   settlement,
     vibration,  expansion, or contraction.
     [Note.—The  piping  system  installation  procedures described  in
     American Petroleum  Institute (API)  Publication  1615  (November
     1979), "Installation of  Underground  Petroleum  Storage Systems,"
     or ANSI Standard  831.3,  "Petroleum  Refinery  Piping," and  ANSI
     Standard B31.4 "Liquid Petroleum  Transportation  Piping System,"
     may  be  used,  where  applicable,   as  guidelines  for   proper
     installation  of piping systems.]
(f)   The  owner  or  operator  must  provide the   type  and  degree  of
     corrosion   protection  recommended  by an   independent  corrosion
     expert,  based  on  the  information  provided   under   paragraph
     (a)(3) of  this section,  or  other  corrosion  protection  if  the
     Regional  Administrator  believes other  corrosion  protection  is
     necessary  to  ensure  the  integrity  of the  tank  system  during use

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                                   4-6


     of the tank  system.   The  installation of a corrosion protection
     system  that   is  field  fabricated  must  be  supervised  by  an
     independent corrosion expert to  ensure proper installation.
(g)  The  owner  or  operator  must  obtain  and  keep  on  file  at  the
     facility  written  statements   by   those   persons   required  to
     certify  the   design   of  the  tank,  system  and  supervise   the
     installation    of   the  tank  system  in   accordance   with   the
     requirements   of  paragraphs  (b) through  (f) of  this  section,
     that  attest   that  the  tank  system  was  properly  designed  and
     installed and  that repairs,  pursuant  to paragraphs  (b)  and  (d)
     of this  section, were performed.   These written statements  must
     also  include  the  certification statement  as required  in  Sec.
     270.ll(d) of  this  Chapter.


Guidance
A)   Design Standards


Adherence  to   nationally   accepted   design   standards  would  facilitate

compliance with  the structural  integrity  requirements  of Sees.  264.191

and 264.192.  Table  4-1  lists the applicable design  standards  for tanks.

The  permit  applicant  must  demonstrate  that  all   ancillary  equipment

complies with similar  national  design standards,  such as  those listed in

the American National  Standards  Institute/American  Society of  Mechanical

Engineers  (ANSI/ASME)  publication  B31.3,  "Chemical  Plant and Petroleum

Refinery Piping," (Tables 326.1 and A326.1, for metallic  and  non-metallic
components, respectively).


The  standards   in  Table  4-1  are  updated  continually.  It  is  up  to  the
permit  applicant  to demonstrate  compliance  with  the  most recent  set.of

applicable design  standards.   Check with  the  following  organizations  for
more information on standards:
The Aluminum Association (AA)    American Petroleum Institute (API)
818 Connecticut Avenue, N.W.     1220 L Street, N.W.
Hashington, D.C.   20006         Washington, D.C.   20005
(202) 862-5100                   (202) 682-8000

American Concrete Institute      American Society  for Testing
  (ACI)                            and Materials (ASTM)
22400 West Seven Mile Road       1916 Race Street
Detroit, MI  48219               Philadelphia, PA   19103
(313) 532-2600                   (215) 299-5400

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                                            OSHER Policy Directive No.  9483.00-1
                                        4-7
                                   TABLE 4-1

                   NATIONALLY ACCEPTED TANK DESIGN STANDARDS
Document Number
AA-ASD-1
AA-ED-33
AA-SAS-30
ACI-344R-70
ACI-350R-77
AISI-PS-268-685-5M
AISI-TS-291-582-10M-NB
ANSI B96.1
API 12B
API 12D
API 12F
API 620
API 650
ASME BPV-VIII-1
ASTM D 3299
Title
Aluminum Standards and Data, 1970-71
Engineering Data for Aluminum Structures
Specifications for Aluminum Structures
Design and Construction of Circular
Prestressed Concrete Structures
Concrete Sanitary Engineering Structures
Useful Information on the Design of
Plate Structures
Steel Tanks for Liquid Storage
Standard for Welded Aluminum-Alloy
Storage Tanks
Specification for Bolted Tanks for Storage
of Production Liquids, 12th Ed.
Specification for Field Welded Tanks
for Storage of Production Liquids, 8th Ed.
Specification for Shop Welded Tanks for
Storage of Production Liquids, 7th Ed.
Recommended Rules for Design and Construction
of Large, Welded, Low-Pressure Storage Tanks
Welded Steel Tanks for Oil Storage
ASME Boiler and Pressure Vessel Code
Standard Specification for Filament-Wound
Date
1984
1981
1982
1970
1983
1985
1982
1981
1977
1982
1982
1982
1984
1980
1981
ASTM D 4021
Glass-Fiber Reinforced Thermoset Resin
Chemical Resistant Tanks

Standard Specification for Glass-Fiber
Reinforced Polyester Underground
Petroleum Storage Tanks
1981
Continued on next page.

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                                                 Honey Directive rto. y4oj.uu-i


                                        4-8


                              Table  4-1—Continued
Document Number
AWWA-D100
NFPA 30
UL 58
Title Date
Standard for Welded Steel Tanks for 1984
Water Storage
Flammable and Combustible Liquids Code 1984
Standard for Steel Underground Tanks 1976
                         for  Flammable  and  Combustible  Liquids

UL 80                    Standard  for Steel  Inside  Tanks for Oil           1980
                         Burner  Fuel

UL 142                   Standard  for Steel  Aboveground Tanks  for          1981
                         Flammable and  Combustible  Liquids

UL 1316                  Standard  for Glass-Fiber-Reinforced Plastic       1983
                         Underground Storage Tanks  for  Petroleum  Products

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                                        OSHER  Policy  Directive  No.  9483.00-1
 American  Iron  and  Steel
   Institute  (AISI)
 1000 Sixteenth Street,  N.w.
 Washington,  D.C.   20036
 (202)  452-7190
 American  National  Standards
   Institute,  Inc.  (ANSI)
 1430 Broadway
 New York,  NY   10018
 (212)  354-3300

 National  Fire Protection
   Association (NFPA)
 Batterymarch  Park
 Quincy, MA 02269
 Publications:  (800)  344-3555
                                    4-9
American Society of Mechanical
  Engineers (ASME)
Publications
22 Law Drive
Fairfield, NO  07007
(201) 882-1167

American Water Works Association
  (AWWA)
6666 West Quincy Avenue
Denver, CO  80235
(303) 794-7711

Underwriters Laboratories, Inc. (UL)
333 Pfingsten Road
Northbrook, IL  60062
(312) 272-8800
 For  any  nonspecificatlon  tank  system (i.e., one  that does not comply  with
.the  applicable  design  standards  listed  in  Table  4-1),  the   owner  or
 operator  must   demonstrate   that:    1)   the   system  is  constructed   in
 accordance  with  sound   engineering principles  and  may  safely  contain

 hazardous   waste;  and  2)  the  tank has  the   dimensions   and   thickness
 necessary   to   contain   its   contents  for  a  given  service  life.    The

 calculations  must account  for  internal   liquid  pressure,  internal  vapor
 pressure,   hydrostatic   pressure,   vehicle  loading,  and  the  tank  shell
 thickness-reducing effect of  corrosion  (i.e.,  tank  thickness must  include
 a "corrosion  allowance,"  if  applicable).    It  is  desirable  for all  new
 tanks  to  be  provided with  a means  of  entry   (e.g.,  a manway)  to  make
 internal  inspections  easier.
 Bottom Pressure.  Bottom  pressure  is  defined as liquid height  multiplied
 by  liquid  density.   Tank  internal   vapor   pressure   is   the   difference
 between atmospheric pressure and  the  pressure  in  a  tank.   A  tank  designed
 for contents  with  a  particular  density  should  not  be  filled  with  a
 material  of a greater density.   In cases  where  it  is  necessary  to store  a
 heavier  waste   than  a  tank  was   designed  for,  calculations  should  be
 performed to determine  the maximum fill  height that  can be used  without
 encountering  excessive  bottom  pressure.   American  Petroleum   Institute

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                                       OSWER Policy  Directive  Ho.  9483.00-}

                                   4-10

(API)  Standards  620  and   650,   "Recommended   Rules   for  Design   and
Construction  of Large,  Welded,  low-Pressure  Storage Tanks"  (1982)  and
"Welded  Steel  Tanks  for  Oil   Storage"   (1980),  respectively,   provide
extensive  information  on  design  calculations.   The  American Society  of
Mechanical Engineers (ASME) "Boiler and Pressure Vessel Code"  (1980)  also
provides guidelines  on tank design.

lank  Wall  Thickness.    Using established  performance  standards  or,  in
their  absence,  best  engineering  judgment,  the  owner  or  operator  must
determine  whether   a  tank  has  an  adequate   margin  of  safety  for  tank
thickness.   Tanks designed according  to   standards  or  codes  often  have
inherent  theoretical  safety factors  in the range of three to five.   The
engineer  should remember  that underground., fiberglass-reinforced  plastic
(FRP)  tank  designs  require  that  backfill  provide much (up  to 90 percent)
of  the  tank's  structural  support.    Uniform  backfill   support  is  also
important for underground steel  tanks.

The  Steel   Tank  Institute  has  developed   guidelines  for  the design  and
construction  of  steel  double-walled  tanks,  entitled  "Standard  for  Dual
Wall  Underground  Steel  Storage  Tanks" (1984).   A  similar guideline  has
not been developed,  however, for FRP  double-walled  tanks.  Manufacturers'
data  and/or UL design approval will  have  to  be  used to  convince  the  EPA
of  the  structural integrity of  such a tank.   (Underwriters  Laboratories,
Inc.,  is  currently  in  the  process of   developing  double-walled  tank
standards for both steel  tanks and  FRP tanks  which  are to  be  referred to
as  "UL-listed Secondary Containment Tanks".)

Venting.  Tank  venting must be  shown  to be adequate.   The  vapor pressure
within a tank must either be maintained at  atmospheric pressure  or within
the pressure  limitation  of the  tank design.   Normal  vents  are needed for
atmospheric  and  low-pressure tanks  that   are  not  constructed  to  handle
excessive   pressure  or   vacuum   buildup.    High-pressure  tanks  require
emergency  vents.    Venting   capacities  are  based  on  maximum  emptying,
filling, thermal inbreathing, and outbreaking rates.

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                                       OSWER Policy Directive No.  9483.00-1

                                   4-11

Venting can be  accomplished  under normal  operating  conditions with  open
vents, pressure-vacuum valves, pressure-relief  valves,  and pilot-operated
relief  valves.    Each  valve  type  is   designed  for  specific  physical
characteristics   of  the  tank's   contents.   Pressure-vacuum  valves   are
designed  for   atmospheric  storage  tanks   containing  low-boiling  point
liquids.  Pressure-relief valves  are  used  chiefly for  liquid  storage and
generally should not be used  for  gas  or  vapor service.  Rupture discs and
resilient valve  seats  are often  used in conjunction  with  pressure-relief
valves for storage  of  corrosive,  viscous,  and polymerizable liquids  that
can  damage  valves.   Pilot-operated  valves  are  generally  used  when the
relief  pressure  is  near  the operating   pressure,  and  in  low-pressure
tanks,  but  not  in  tank systems  with  viscous   liquids or liquids  with
vapors that  can  polymerize.

Floating roof  tanks also prevent  vapor buildup.    For  emergency  venting,  a
tank may have a  roof-to-shell  weld attachment designed for early failure
during pressure   buildup,  larger  or additional  normal  vents and/or  gauge
hatches, or  manhole covers that open  at  -a  designated  pressure.

Vent  sizes  should  be  determined  according to  standards such  as  API
Standard  2000,   "Venting  Atmospheric  and  Low   Pressure   Storage  Tanks"
(1982).   National   Fire  Protection  Association  (NFPA)   Standard   30,
"Flammable and Combustible Liquids Code" (1984)  also  provides  vent design
information.   Vent  piping for an  underground tank should  extend several
feet  above  ground  level  to  prevent fumes  from  concentrating  near  the
ground.  Such piping  should  be a minimum of two feet  higher than  adjacent
buildings.   Rain caps on vent piping  are advisable.

Ancillary Equipment.    Nonspeclfication  tank system  appurtenances  also
must  have  the   appropriate   strength  to  handle  the   maximum  internal
stresses expected.  The  owner or  operator must  assess  the ability  of  a
tank  system's  ancillary equipment,  including   piping,  flanges',  valves,
fittings, pumps, etc.,  to handle  the waste materials (liquid,  slurry,  or
vapor)   in   the  volumes  expected.    Any  manufacturer's   test   results
demonstrating  the  strength  of  a  particular  tank  system   component  will

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                                             r-oiic> uirective  flo.

                                   4-12

help convince  the  EPA of  the  system's  structural  integrity.   In  other
words,   the  owner  or  operator  should  be  able  to  demonstrate  that  the
maximum  stress  (taking   into   consideration   ambient   temperature   and
pressure)  to  which  a  component  will   be   exposed  is  less  than  the
manufacturer's maximum allowable  design  stress,  including  an  adequate
safety factor.

B)   Characteristics of Haste

The  owner  or  operator must  assess  the  "hazard  characteristics  of  the
waste(s)" and the ability of  a  tank system  to handle  such  waste(s).   The
EPA  interprets this  statement in  Sees.  264.191  and 264.192 to mean that a
tank  system  must  be  compatible  with  its   contained  waste,  mixture, of
wastes or treatment  reagents.   Thus,  any portion of a tank system (e.g.,
tank  lining,  tank  outer   shell,  piping,  valves,  fittings,  pumps)  that
comes  into  contact  with  waste  must   not  deteriorate  in  the  waste's
presence.  Linings  are often  added  to a tank to ensure  the compatibility
of the waste  with the tank.

The  owner  or  operator of  a  tank  system  must obtain  a  detailed chemical
analysis of  the  contained  waste.   The  owner  or operator  must use  this
analysis and  knowledge of the  ignitabi1ity, corrosivity,  reactivity,  and
EP toxicity of a waste stream  to determine  if  the  stream  is  compatible
with its tank  system.   Table 4-2 describes  the impact  of these factors on
tank design.   To convince the EPA of  the compatibility of stored waste(s)
and  containers,  data may  be used from the  "Chemical  Engineers' Handbook,"
the  National   Association  of  Corrosion  Engineers (NACE),  facility tests,
and  manufacturers.    (See  Section  13.0  of   this   document  for  more
information on waste compatibility.)

Table  4-3  presents  the   compatibility   of  common  tank  construction
materials  with   various   chemicals.   Generally,   the   assessment   of
compatibility for the  purposes  of Table 4-3  was conservative,  e.g.,  the
internal corrosion  rate for metals had to be  less than  2/1000 inches per

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                                            OSHER Policy  Directive  No.  9483.00-1


                                        4-13
                                   TABLE 4-2

               IMPACT OF SELECTED WASTE PROPERTIES  ON  TANK  DESIGN


	Haste Property	Impact on Tank Design	

         Ignitability                  Generally,   steel  or FRP  are  used
                                       for  the  tank,   and  the  tank  must
                                       have  a  closed  top or must  provide
                                       a means to  prevent  sparks  or  fire
                                       from    contacting    the    ignitable
                                       liquid  or  vapor.

         Corrosiveness                 A material  of  construction  for  the
                                       tank  must  be  selected  that has  a-
                                       low    corrosion   rate,    or    an
                                       effective     lining    or    coating
                                       material   must   be  used  that   is
                                       compatible   with   the   waste   and
                                       operating  conditions.

         Reactivity                    None,  unless reactive  with  carbon
                                       dioxide in  the air, in which  case
                                       the  tank should have  a closed  top
                                       to prevent  reactions.

         EP Toxicity                   Tank    should    generally   have   a
                                       closed     top     (unless      toxic
                                       components   are   not  volatile   or
                                       components   are  of  low volatility
                                       and    are    not   toxic   at    low
                                       concentrations).


Source:   "Permit Writer's Guidance Manual for  Hazardous Waste Tanks"  (undated
          draft),  U.S.  Environmental   Protection   Agency,  EPA   Contract  No.
          68-01-6515, pp. 3-7.

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                                            OSWER  Policy  Directive  No.  94
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                                            OSHER Policy Directive No. 9483.00-1
                                        4-15
                              TABLE 4-3—Continued
Material
Compatible Hith
Incompatible With
Aqueous Salts
    Calcium chloride
    Sodium sulfate
    Copper sulfate



    Ferric chloride



    Sodium hypochloride

    Stannous chloride


    Sodium chloride
FRP
Concrete (If concrete
is alternately wet and
dry with the solution,
then calcium chloride
can induce slow disinte-
gration).

FRP
Concrete—di sintegration
of concrete with inade-
quate sulfate resistance.
Concrete products cured
in high-pressure steam
are highly resistant to
sulfates.

FRP
Concrete—slow
distintegration

FRP
Concrete—slow
disintegration

Special  metal alloys

Noble metals
Stainless steel to 501

FRP
Concrete—unless concrete
is alternately wet and dry
with the solution.
Mild steel(7)
Mild steel
Mild steel



Mild steel



Mild steel

FRP


Mild steel
Footnotes at end of table.

Continued on next page.

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                                                 roiicy Directive No. 9483.00-1
                                        4-16
                              TABLE  4-3—Continued
Material
Compatible With
Incompatible Nith
Aqueous Salts (Continued)
    Alum
Solvents
    Perchloroethylene


    Carbon tetrachloride


    Ethyl  alcohol  (11)


    Methyl ethyl  ketone


    Acetone
Miscellaneous
    Benzene
    Hexane

    Aniline
FRP
Concrete—disintegration
of concrete with Inadequate
sulfate resistance.   Con-
crete products cured 1n
high-pressure steam are
highly resistant to sul-
fates.
FRp(8)
Concrete(9)

FRP(10)
Concrete^)

Mild steel
Concrete

FRp(12)
Concrete

FRP(14)
Concrete; however,
acetone may contain
acetic acid as impurity.


FRP(16)
Concrete

Mild steel(17)

Stainless steel(18)
Mild steel
Mild steel


Mild steel


Stainless steel


Mild steel (13>


Mild steel(]5)
Mild steel
FRP

FRP
Mild steel
Footnotes at end of table.

Continued on next page.

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                                            OSHER Policy Directive No. 9483.00-1
                                        4-17
                              Table 4-3—Continued
Material
Compatible With
Incompatible With
Miscellaneous (Continued)
    Nitrobenzene
    Phenol
    Chlorobenzene


    Naphthalene

    Benzoic acid


    Diethyl amine

    Formaldehyde
FRP<19)
Mild steel                    FRP

Mild steel
Stainless steel
Concrete—slow disinte-
gration

Mild steel
Stainless steel

Mild steel(20)               FRP<21)

Special metals               Mild steel
(nickel-base alloys)

Mild steel(22)

FRP                          Mild steel
Stainless steel
Concrete—Slow disin-
tegration due to formic
acid formed in solution
                                     NOTES:
 (1)  Needs the attention  of  a corrosion specialist.  FRP  is  good up  to 707.
      concentration.  Mild  steel  (M.S.)  is  good for concentrations from 931 to
      981.

 (2)  Fiberglass-reinforced   plastics   (FRP)   have  been   considered   here.
      However, there are  fiberglass-reinforced  epoxy resins available that are
      not considered in this table.
Continued on next page.

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                                                          i receive  no.
                                        4-18
                              Table  4-3— Continued

                                     NOTES:
 (3)  FRP  is  good  to  301  concentration.   No  organic  solvents  should  be
      present.    The  National   Association  of  Corrosion  Engineers   (NACE),
      Houston,  TX, has a  graph  for  the  compatibility of  various  metals  for HC1
      use.
 (4)  FRP is good to 151  concentration.
 (5)  M.S.  is good  only  to 25'C.   316  stainless steel  (S.S.)   is  recommended
      for service conditions about 25°C.
 (6)  FRP is good to about 50% concentration.
 (7)  M.S.  is incompatible after about 51 concentration at  100'C.
 (8)  FRP is good to about 25*C.
 (9)  Impervious  concrete  is required  to prevent  loss  from penetration,  and
      surface treatments  are generally used.
(10)  FRP is good to about 125'C.
(11)  FRP is good> for 951 concentration  and 21°  to 66°C.
(12)  FRP is good from 10° to 35°C.
(13)  M.S.  is incompatible for concentrations  below  1001.
(14)  FRP is good for 101 concentration  and 21°  to 79.5eC.
(15)  M.S.  is Incompatible for concentrations  below  1001.
(16)  FRP is good from 10° to 32°C.
(17)  M.S.  is good for 1001 solvent  to 100'C.
(18)  S.S.  is good to 1001 concentration.
(19)  FRP is good for 51  concentration and 21°  to 52'C.
(20)  M.S.  is good to 1001 concentration.
(21)  FRP is good  for  only 1001 concentration and 21° to  27°C;  therefore,  it
      is listed as incompatible.
(22)  M.S.  is good only at 1001 concentration  and up to  100'C.

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                                       OSHEK Policy Directive No.  9483.00-1

                                   4-19

year.   This  table  is,  however,  just  a  guideline to  waste/construction
material  compatibility,  and  the EPA  Regional  Administrator may  require
additional evidence of compatibility.

Underground  concrete  tanks  may  require  internal  surface  protection  for
hazardous wastes  that  tend  to disintegrate concrete slowly.  The  type of
protection  that  should  be  used  against  chemical   attack   will   vary
according  to the  kind and  concentration of  the chemical, frequency of
contact,  and   physical   conditions,    such   as   temperature,   pressure,
mechanical wear  or abrasion,  and  freeze-thaw  cycles.   For  more  specific
information  on   concrete/waste  compatibility,  see  the  Portland  Cement
Association's "Effects  of  Substances  on Concrete  and Guide  to  Protective-
Treatments"  (1981).   Where  conditions  may  cause deterioration  of  'the
concrete around  the  reinforcing steel,  a method for the direct  protection
of  the  steel  may  be  desirable  (See  American  Society for  Testing  and
Materials (ASTM) publication number  A775).

Many  types  of protective  coatings  or barriers will prevent  contact with
the concrete  surfaces.  To  be successful, any  such coating must  exhibit
good  adhesion  to  the   concrete  and must  be  completely  impervious.   For
example,  various  thermoplastic  and   thermosetting  coatings,   ceramics,
chemical-resistant  mortars,  sheet   or  liner  materials,   and   composite
barriers have these  characteristics.   If conditions are severe enough  to
deteriorate  good quality  concrete,  it  is  difficult  to provide  complete
and  lasting  protection.   Consideration  should  be  given to  neutralizing
severely aggressive liquid wastes.

When   special    protection   is   required   for   the    reinforcing   bars,
epoxy-coated bars, which should conform to ASTM A775,  are preferable.

Although  FRP  tanks are generally referred to  in  a  way  that  denotes  a
single  type  of  storage tank,  they actually can  be fabricated  from a wide
variety  of  plastic  resins.   The  selection  of  resin   depends  upon  the
material  to  be   contained  and the conditions  of  storage.  Most  FRP  tanks
now in use are constructed from  isophthalic polyester resin.  Because  the

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                                                             no.
                                   4-20
resins used  for  FRPs can  change  with exposure  to stored  wastes,  It  is
Imprudent  to  reuse  an  FRP  tank  of  unknown  origin and  age,  unless  the
prior use of the  tank is known and  the  tank manufacturer is consulted  on
the compatibility of the tank resin  with  the new  stored  waste.

C)   Corrosion Protection  Measures

For  existing  tank  systems and components,  Sec.  264.19Kb) requires  that
the  assessment must  consider  the  existing  corrosion protection  measures.
Guidance for  such  an assessment  is  described in detail  in Section  5.4.1
of this document, "Corrosion  Potential Assessment."

D)   Documented Age of the Tank System

If available, the assessment  must  include  the documented age of  the  tank
system,  including  the   age   of   any  replacement  components.    If  such
documentation is  unavailable, an  estimate of the  age should be made  and a
brief  discussion  of the  reasoning  behind   it  should  also  be  included in
the assessment.

E)   Leak-tests,  Inspections, and  Other  Examinations

Sections 264. 191 (b)(5) and 264.192(d) require  the results of a  leak  test,
an  internal  inspection,  or other  tank integrity  examination for  existing
aboveground  or  enterable  tanks.   For  non-enterable,   underground  tanks,
the  assessment  must include  a leak test  that is  capable  of  taking  into
account the effects of temperature variations, tank end deflection,  vapor
pockets,  and  high   water  table  effects.   For  other   than  non-enterable
underground  tanks  and  for  ancillary  equipment,  the  assessment  must
include  either  a  leak  test or  other  integrity examination  that  is
certified  by  an  independent,  qualified,  registered professional  engineer
that  addresses  cracks,  leaks, corrosion,  and erosion.  It is  the  EPA's
intent that operators and owners  select a  leak-testing  technology that is
consistent  with  state-of-the-art  engineering  practices  and leak-detection
accuracy   limits.    Section   264.191   requires   that    an   independent,

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                                       OSWER Policy Directive No.  9483.00-1

                                   4-21
           •
qualified, registered  professional  engineer review  and  certify  all  such
tank and  piping  leak-tests  and  any other Inspections and  examinations  to
ensure  that   all  methods  chosen  and  implemented  are   consistent  with
state-of-the-art  test  methodology  and  current  leak-detection  accuracy
limits.

The  EPA   is  currently  involved  in  a  research  effort  to  evaluate  the
effectiveness  of  different  leak-testing   technologies.    A  preliminary
report,   entitled   "Underground   Tank   Leak   Detection    Methods:    A
State-of-the-Art  -Review,"  has   recently  been  published   by  the  EPA's
Hazardous Waste Engineering Research  Laboratory, Contract  No.  63-03-3069,
Cincinnati,  Ohio,  (June 1985).   This  report describes  both commercially
available  and  developing  techniques  for  detecting  leaks  in  underground
storage  tanks.   The  report includes  information  on variables  affecting
leak-detection methods  and  describes  36 different test methods  covering
volumetric and nonvolumetric leak-detection  techniques,  inventory-control
monitoring methods,  and techniques  to  determine  the effects  of  leaks.
The  individual  descriptions  discuss  operating  principles,  means  for
compensating  the  effects of  test  variables,  and limits  on  applicability
and  accuracy.    (See   Table  4-4.)    EPA   in  the  future  will   publish
additional   information  and   guidance   on   leak   testing,   including
evaluations of test methods.

The owner  or  operator  should  carefully choose the  leak-testing method  to
be  used  after  consulting  with  a  qualified,   independent,  registered
professional    engineer  who   will   review   and   certify   the   written
assessment.  The  test  method must  be chosen with  regard  to  accuracy  and
safety.    Some  hazardous   waste   may  be   incompatible   with  some  test
equipment, and some  waste  may  create  hazards  for  the persons  conducting
the  test.    The  owner  or  operator  may  require  outside,  qualified,
experienced  assistance  to  conduct  leak-tests  that  are as  accurate  as  the
state  of  the  art will  allow  and are  in  conformance  with good  safety
practices.

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OSHtR Policy Directive No.  9433.00-1











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-------
                                                   utieucive  No.
                                   4-26
The  selection  of a  leak-testing  device  must  consider how  its  design
accounts  for  volume  changes  in  tank  contents  caused  by  the  following
factors:
     o    Temperature    changes   during   testing   and   temperature
          gradients  within  a  tank or  piping;
     o    A high water  table  causing  Ingress  of  water;
     o    Tank end deflection caused by  Increased  pressure  in  a  tank
          during testing;
     o    Evaporation  losses;  and
     o    Volume changes of trapped  air  and  vapor  pockets  in  a  tank
          and piping.

Some  of  the  above  factors  can  contribute  potentially  large errors  to
leak-testing measurements;  hence,  they  must be minimized  or  eliminated  by
the  design  of  a  leak-testing  system.   A  discussion  of  each  of  these
factors follows.
     1)    TEMPERATURE

     The liquid or sludge content of a tank generally will expand  in  size
     with increased  temperature  and contract with  decreased  temperature,
     to   a  greater  or  lesser  extent  depending   on   composition.    For
     example,   the  coefficient of  expansion  per degree  Fahrenheit for  a
     predominantly benzene waste  is 0.00071  (see Table  4-5).  That  is,  in
     a  10,000-gallon  benzene  waste  tank,  a  volume change of 7.1  gallons
     wil'l be observed with an  overall 1°F temperature change.  Thus,  in  a
     10,000-gallon benzene  waste  tank,  1t  is  necessary  to maintain  or
     measure  the  tank  temperature  to  approximately 1/100  of  a  degree
     (Fahrenheit)  over a  one-hour  period to  measure a 0.05  gallon  hourly
     leakage rate.   The  necessity for  minimizing  temperature changes  is
     the  reason  why  underground  tanks  can   be  leak-tested  with  more
     accuracy  than  aboveground  or  inground  tanks.   If  a  leak-testing
     device  compensates  for  temperature changes using the  coefficient  of
     expansion of  the tank contents, the tester  must ascertain accurately

-------
                                            OSHER Policy Directive No. 9483.00-1


                                        4-27
                                    Table  4-5

                          THERMAL EXPANSION OF LIQUIDS
                                                     Volumetri c
                                                     Coefficient
                                                     of Expansion
                 Liquid	 	  	(per Degree F)
         Acetone                                       0.00085
         Amyl  acetate                                  0.00068
         Benzol  (benzene)                              0.00071
         Carbon  disulfide                              0.00070
         Diesel  fuel                                    0.00045
         Ethyl  alcohol                                  0.00062
         Ethyl  ether                                    0.00098
         Ethyl  acetate                                  0.00079
         Fuel  Oil  #1                                    0.00049
         Fuel  Oil  #2                                    0.00046
         Fuel  Oil  #3                                    0.0004
         GASOHOL
           .10 Ethyl  +  .90 Gasoline                    0.000674
           .10 Methyl + .90 Gasoline                   0.000684
         Gasoline                                       0.0006 - 0.00068
         Hexane                                         0.00072
         Jet fuel  (,FP 4)                               0.00056
         Kerosene  .                                     0.00049
         Methyl  alcohol                                0.00072
         Stove oil                                      0.00049
         Toluol  (toluene)                              0.00063
         Water at  68°F                                  0.000115
Source:   Health Consultants, Inc., "Procedures Manual for the Operation of the
         Petro-tite Tank Tester,"  Stoughton, MA  1983.

Note.—These are average values and may vary.  It is necessary to use the
       appropriate API hydrometer in order to obtain the proper coefficient of
       expansion.

-------
                                           i wjr  UIICV.LIVC  nu.
                              4-28
what material the tank  contains,  including  the  respective  volumetric
percentages of  a  mixture of  materials.   Haste  layering  in  a  tank
(because of immiscibility)  can also affect  leak-test  measurements.

The  temperature layering  in  an  underground tank  produces  another
leak-testing  measurement difficulty.   Underground  tanks   can  have
numerous  temperature   layers,  since  they   are   never   in  perfect
equilibrium with the surrounding environment and their interiors  are
never  entirely  equilibrated.    Hot days  and cold  nights   can  alter
external  tank  temperatures,  and   additionally,   convection  currents
inside  cause  warmer  contents to  rise  to  the  tops  of  tanks,  while
colder contents move downward.   There  Is  no such  thing  as a  single
"tank  temperature."   The properties of tank contents  that determine
the overall, temperature  effects  (expansion,  contraction,  temperature
layer  gradients)  are the coefficient of expansion with  temperature,
the  heat  conduction  capability,   and  the  viscosity  (related  to
settling time following a disturbance).

2) WATER TABLE
                                             *
A  high  water  table  (i.e.,   one  from  which  water  can  enter  an
underground  tank)  can  cause   a  state  of  hydrostatic  equilibrium,
whereby  there   is  no net  flow from  the  tank,  though  there  may  be
holes  in  the tank.   Leak-detection devices  must account for  this
apparent absence of leakage through detection of water ingress.

3) TANK END DEFLECTION

If a  leak  test  increases the  hydrostatic  pressure within a tank, the
tank  ends  will  deflect,  i.e.,  bulge outward  with  the  increased
pressure  (see  Table 4-6).   The  rate of  tank  capacity  increase,
however, slows over time.  This fact can be  used  to  extrapolate when
tank  end  deflection has  slowed enough so  that it will not  cause a
significant error in a leak-test measurement.

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                                            OSWER Policy Directive No.  9483.00-1

                                        4-29
                                    TABLE 4-6

                            TOTAL FORCE ON  TANK ENDS
          Tank.                   Total  Force In Tons  at:
        Diameter      1  Psl	  2 Psl      3 Psi     4 Ps1      5 PS'
48"
64"
72"
84"
96"
0.9 1.8 2.7 3.6 4.5
1.6 3.2 4.8 6.4 8.0
2.0 4.0 6.0 8.0 10.0
2.8 5.6 8.4 11.2 14.0
3.6 7.2 10.8 14.4 1-8.0
Source:     Health Consultants,  Inc.,  "Procedures Manual  for the  Operation of
           the Petro-tite Tank Tester",  Stoughton,  MA.

NOTE.—Force = Area x Pressure (Ibs./sq. in.).

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                                         O!ic>  Directive  No.  y4ej.00-i

                              4-30

4) EVAPORATION

During the test  period,  volume  changes  caused  by evaporation must be
compensated   for   1n   leak-test   calculations.    Evaporation   and
condensation   rates   are  enhanced  by mixing   additional  product  (a
necessary step  for  some leak-testing systems)  with product  already
in a tank at  a different temperature.

5) TRAPPED AIR AND VAPOR POCKETS

If a  tank is  filled for testing  purposes,  the tank  and  its  piping
may contain  an unknown  amount  of air.    This  air  can compress  and
expand  readily  with   pressure   changes,   causing  apparent .volume
changes.   Additionally,  a  tank content's  mass  and the  spring-like
effect of  any trapped  air  can  produce  an  oscillation.   (Grundmann,
Werner,  "PALD-2  Underground  Tank  Leak  Detector  and  Observation  of
the   Behavior   of  Underground   Tanks,"   study  presented   at   the
Underground  Tank  Testing   Symposium,   May  25-25,   1982,   Petroleum
Association  for  the   Conservation  of  the   Canadian  Environment,
Ottawa, Canada,  p.  17.)  The  oscillation can  be  initiated  by  ground
motion, such  as from traffic,  and  by adding waste to a tank.

Vapor pockets form in three ways:

     o    At   the high  ends  of  a  tank  when  the  tank  is  not
          perfectly level;
     o    When vapor is trapped  in the  top of  a manway; and
     o    When vapor is trapped  at the  top of  a drop tube.

If a  vapor pocket  is   released  to  the  atmosphere  when  it  expands
because of decreased barometric pressure or Increased temperature, a
sensor-measuring liquid-level  will record a drop if  liquid  fills  the
pockets.    Similarly,  if a  vapor  pocket is   compressed because  of

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                                       OSHER Policy Directive No.  9483.00-1

                                   4-31

     increased   barometric   pressure   or   decreased   temperature,   the
     liquid-level will appear to rise.

     6)   SLUDGE

     The  presence  of sludge  on  the  bottom of  a  tank  can  seal  over  a
     failure  in  the  vessel  and  hide a leak.  Because the  sludge is not an
     integral component of  the  tank,  it  is not  expected  to  continue  to
     seal the leak.   In  addition,  sludge  may lead  to  Inaccurate  readings
     in  some leak-testing   designs.   With  proper  cleaning  and  safety
     procedures, a sludge layer  can be removed.

F)   Internal Inspections

For  existing  enterable  tank  systems,   an  internal   inspection  is  an
alternative  to  leak-testing,  according to Sec.  264.191(b)(5)(ii).   It  is"
often appropriate  to  coordinate  this  inspection with the  time when a tank
system  is  taken out  of  use  for  routine  preventive maintenance.   API's
"Guide  for  Inspection  of  Refinery  Equipment"  (particularly  chapters
X-XIII and XV-XVI) is a useful reference  for tank system inspection.

An  internal   visual   inspection  of  a  tank may  be  carried  out  by  an
independent,  qualified,   registered   professional  engineer   to  detect
potential  sources  of leakage,  such  as   corroded,  cracked,  or  broken
equipment.   The internal  inspection  Involves  two  major  phases—cleaning
the tank  and performing  the  actual  inspection.   Guidance for  conducting
Internal inspections 1s given below.

     1)   PREPARATION FOR INTERNAL INSPECTION—TANK CLEANING

     Prior to an  Internal  inspection,  tanks must be emptied  and  cleaned.
     A general  overview  of  proper  tank-cleaning  procedures  is presented
     here and  is  summarized  from  Section 5 of  "Toxic  Substances  Storage
     Tank Containment Assurance  and Safety  Program Guide and  Procedures
     Manual," Maryland   Department  of Health  &  Mental  Hygiene  (1983).

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                                                  c >. w I V £
                              4-32
[For more detailed procedural  Information,  see  API  Publication  2015,
"Cleaning Petroleum Storage  Tanks"  (September  1985);  API 2015A,  "A
Guide for Controlling the  Lead  Hazard  Associated  with  Tank  Entry and
Cleaning"  (1982);  API   2015B,  "Cleaning   Open-Top   and   Covered
Floating-Roof Tanks"  (1981); NIOSH, No.  80-106,  "Working  In  Confined
Spaces"  (December  1979);   and  NFPA   Standard   327,   "Cleaning  and
Safeguarding  Small Tanks  and Containers (1982)."]

Tank cleaning  can be an  extremely  dangerous task  if not  performed
carefully and  correctly.   Fire,  explosion,  oxygen  deficiency  and
poisoning  may  result   from  improper   removal  of  even  very  small
quantities  of  solid,   liquid,   or  gaseous  remnants   of  hazardous
constituents  from  tanks.   Therefore,   particular  attention  should be
given to ventilation  and  sludge removal in the tank-cleaning process.

The first major task  in  this process involves external  inspection of
the  tank  and  preliminary  inspection of  tank-cleaning  equipment.
Next the  dike  area  should  be freed of  volatile or  toxic materials.
The tank  then  can be  emptied of its contents.   Pumping  and floating
with water  is  the most  commonly used  procedure  for  tank  emptying.
All tank  lines  should be disconnected  and emptied as well.   When all
liquid and solid  contents  have  been  removed from  the tank  and its
tank  lines  and  transferred  to a  suitable  temporary  storage  space,
vapors then  must be flushed  from  the  tank.   Steaming,  ventilating
with  air or  an  inert  gas, or removing with  water are all  viable
methods  for  vapor  removal.   Most  important in  the  vapor  removal
process  is using  a  method  which Is  compatible with the chemical that
was stored.   To make certain  that  a tank has been  completely purged
of  vapors,   the  tank   should  be   tested  for  contents  of  oxygen,
hydrocarbon vapors,  and  toxic gases.    The combustible  gas and oxygen
meter should be  used.   These meters can also be used to determine if
there is an adequate oxygen supply.

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                                  OSWER Policy Directive No.  9483.00-1

                              4-33

Tank  Cleaning  Without  Entry.   After  the  aforementioned  steps  have
been  performed  in the  order  discussed and  the tank  is  temporarily
vapor free,  tank cleaning  from  the outside  of the  tank  may begin.
Remaining  manway covers,  riveted  door  sheets, or  bolted  cleanout
cover plates may be  removed.   A water hose  pointing  inward  from the
tank  shell  may  be used  to loosen  excess  sludge and  float   it  to  a
water-pump  connection.   For a  system  which has  contained ignitable
wastes,   all  nozzles   should  be electrically bonded  to tank  shells
during  use.   All  lighting and electrical  equipment  used  Inside  or
near  the  tank-s  should be intrinsically safe  or grounded  to  prevent
sparks.   Maintenance  of  adequate  ventilation at shell manways during
this  process  is  essential.   Vapor concentration  should  not  rise
above 50 percent of  the lower flammable  limit.   If  the  level  does
rise above 50 percent,  washing  should  be  stopped until  a  safe level
of concentration Is re-established.

Pumping   equipment  used  for  the  removal  of  sludge  and  excess  water
from  tanks  should  be  carefully selected.   Equipment  driven  by  air,"
steam,  or  an  approved  electrical  drive  is  preferred.   (When  it  is
necessary  to resort  to open type, electric  power or  gasoline-driven
pumping   equipment, see  API  2015,  "Cleaning Petroleum Storage Tanks,"
for specifics.)

Steam treatment  is  the most convenient method  for cleaning  without
entry.   After 10 minutes of steaming,  the tank should be washed with
hot water to remove solid debris.

Chemical  cleaning may  be  an  alternative,  should  steaming  prove
inadequate.    When    using    hot   chemical   cleaning   solutions,
temperatures  of  170'F  to  190'F  should   be  maintained.    Chemical
solutions  should only be used after determining  their compatibility
with  the tank material.

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                                         OilCy  uii't'tClvS  .SO.  94o_ . OU-1

                              4-34

Tank Cleaning  Nith  Entry.  Safe  conditions  must  exist  in the  tank
before entering it for cleaning.   Prior to work,  the  interior  of  the
tank  should  be  inspected  for   physical   hazards,   such   as   loose
rafters,  angle  Irons,  or  columns.    Oxygen  and  combustible  gas
readings  should  be  taken  at  frequent Intervals  while work  is being
performed in the tank to avoid exposure to hazardous  vapors.

Three  classes  of   atmospheric   hazards   1n  tanks  must  also   be
considered:   1)  Inadequate  oxygen; 2)  flammable  gases;  or  3) toxic
gases.  To  minimize  the  possibility of explosion,  tanks must  not  be
entered until  flammable  vapors are shown to be less  than  20 percent
of the  lower  explosive limit.  After  meeting this condition,  oxygen
must  be  shown to be equal to or greater than  19.5 percent  of. the
tank atmosphere.  If  the oxygen   is  less than 19.5  percent,  an  air
supply  (full-face,  pressure  demand)  must  be  used.   This  level  of
respiratory protection  will  also  guard  against  exposures to toxic
gases.   If  a  tank  is  to  be  entered  without  a full-face, pressure-
demand  air  supply,  then  the  concentrations  of  toxic gases must  be
known  and  not  exceed acceptable  levels, as  defined by  either  the
Occupational Safety and Health Administration (OSHA), 29 CFR  1910 or
The  American  Conference  of  Governmental  Industrial  Hygenists (6500
Gleway Avenue, Cincinnati, OH  45211;  (513)  661-7881).

2)   INTERNAL INSPECTION

The  second   phase   of  the   Internal   inspection   is  the   actual
performance   of  the    inspection.    Internal   preliminary   visual
Inspection, Inspection of roof and structural  members, tank  shells
and  tank  bottoms  should  all  be integral parts  of a complete internal
Inspection  program.  See  Table 4-7 for tank features  that should be
investigated   in  an  internal  inspection.    Table  4-7  also  lists
advanced  inspection techniques that may be used.    This table  and  the
discussion  which follows refer  primarily  to  steel or  fiberglass
tanks.  Guidance  on  the  inspection of concrete tanks  is  included at
the end of  this section.

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                                            OSHER Policy Directive  No.  9483.00-]
                                        4-35
                                   TABLE 4-7

                     CHECKLIST FOR TANK INTERNAL  INSPECTION
                              (Tank Out of Service)
Solid Steel  Tanks

(1)  Roof and Structural  Supports  (visual  first  for  safety)
          no hazards of falling objects
          corrosion

(2)  Roof and Structural  Supports  (more  rigorous)
          loss of metal thickness
          cracks, leaks at welds
          cracks at nozzle connections
          malfunctioning  of floating  roof  seals
          water drain system deterioration
          hammer testing, if necessary

(3)  Tank Shell
          cracks at seams
          corrosion of vapor space and  liquid-level  line
          cracking of plate joints
          cracking of nozzle connection  joints
          loss of metal thickness

(4)  Tank Bottom
         •corrosion pits
          cracked seams
          rivets for tightness and corrosion
          depressions in  bottom areas around or  under roof and pipe supports
          bottom thickness
          uneveness of bottom
          hammer testing  and bottom sampling,
          general condition of liner  (holes,
          swelling, hardness, loss of thickness)
          bulges, blistering, or spalling
          spark testing of rubber, glass,  and organic type coatings
          ultrasonic examination of  steel  outer shell  thickness,  if  possible,
          if any deterioration is  suspected.
 if  necessary
cracks, gaps,
                                                            corrosion,  erosion,
Source:   "Permit Hriter's  Guidance  Manual for  Hazardous  Waste  Tanks,"  U.S.
          Environmental   Protection  Agency,  EPA  Contract 68-01-6515  (undated
          draft), pp.  8-10 and 8-11.
Continued on next page.

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                                                  KOI icy  uireccive  do.


                                        4-36"
                              TABLE 4-7--Continued
Lined Steel  Tanks*

<1)  General  condition of lining
     --holes
     —cracks
     --gaps
     —corrosion
     — swel1i ng
     —hardness
     --loss  of thickness

(2)  Proper  positioning of liner


Fiberglass-reinforced-plastic Tanks

          softening,  identatlons,  cracks,  exposed  fibers, crazing,  checking,
          lack of surface resin, and delamination
          sufficiently  translucent,  discolored,  porous,  air  or other  bubbles
          visible, other inclusions, and thin areas
          hardness testing of specimens exposed to liquid contents
          ultrasonic  examination  of laminate  thickness,  if  possible,   if  any
          deterioration is suspected in the polyester matrix.
*Tanks  may  be  lined  with  alloy  steel,   lead,  rubber,
concrete.   The inspection procedures and locations  noted
are equally applicable to lined tanks.
 .	  —_,   _.   -. —  --....  _..,_,  	.,   . —,  .	,   glass,  coati ngs,  or
concrete.  The inspection procedures and  locations  noted  for  solid  steel  tanks
are

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                                  OSHER Policy Directive No. 9483.00-1

                              4-37

The  types  of corrosion  that may occur  in a  non-uniform  way on the
surface of  the  tank metal  are:  stress corrosion  around  weld seams;
corrosion  at  the liquid-vapor interface;  oxidative  corrosion due to
the  presence  of oxygen  (from the air) in  the  vapor space  of vented
atmospheric tanks;  caustic  embrittlement;  and  hydrogen blistering.
Careful visual  inspection  for these types of  corrosion usually  will
vbe  adequate  to detect  possible defects  that  require  more detailed
examination.  In contrast,  pitting is another  form of  corrosion  that
in  some  cases  may  not  readily  be  detected in  a  visual  inspection.
Thus,  a  visual  inspection  often  must  be supplemented  by  special
inspection equipment to assess a tank's condition fully.

Safety Precautions.  As stressed  in  the  preceding section  on  'tank
cleaning,  the  safety  aspects associated  with  an  internal   inspection
are  very  Important.  A  tank should be  emptied of  liquid, freed of
gases, and cleaned or decontaminated,  if  necessary.   Protection  from
explosive  and  respiratory  hazards  should be  provided for  persons
entering a tank-.   A  complete  discussion  of  safety  procedures for^
internal   tank  inspections   is  beyond the scope  of  this  document.
Persons not experienced  in  the conduct of  Internal  tank  inspections
should   contact   OSHA   for  assistance   in    establishing   safety
procedures.

Adequate  lighting  must  be  provided inside  a  tank for  a  safe and
effective  inspection.   The  roof  and  internal  supports   should  be
inspected  first, followed  by a preliminary visual  Inspection of the
tank shell, to  ensure that the tank is structurally stable.

Roof  and  Structural  Members.   A  visual  Inspection of  the  roof
Interior   usually   suffices.    Thickness   measurements   should  be
performed,  however,  when  corrosion is  evident.   Special  attention
should be given  to  interior  roof seals.

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                                               U i I Cu I I Ve  iTw .  3 HO J . UV -
                              4-38
Tank  Shel 1 .   .The  shell  should be  examined for  visual  corrosion.
Tank shell thickness should  be  measured at representative points  to
ensure  that  thickness   is  maintained.   While the  bottom, the  roof,
and  especially  the  shell  are  being  inspected  for  corrosion,  the
plate  Joints  and  the  nozzle connection  joints  should  be  inspected
for  cracking.    If   any  cracking   Is  found,   a   more   thorough
investigation by  magnetic-particle,  penetrant-dye,  or  radiographic
methods may be needed.

When  the  inside   surfaces  of  a  tank  are  lined  with  corrosion-
resistant material,  it is important  to check  for holes or  cracks.
Scraping or dye penetration  is  effective  for  locating  pinholes  and
tight cracks.  Bulges  in  a lining  indicate leakage behind the lining
and possible lining deterioration..

Tank Bottom.  Tank bottoms  should  be  hammered  thoroughly to detect
corrosion pits and sprung seams.   Hammering generally  should not be
performed in  the  area  around  a leak,  in  an  area  suspected  to  be
extremely  thin,  on  equipment   in  caustic  service,  or on a  brittle
material.   Radiography and  ultrasonic  testing  methods,  which  are
normally  more accurate  than  hammer  testing,   can  be   used  as  an
alternative to hammering in areas around a  leak or in  areas  expected
to  be  extremely  thin.   The  rivets  should  be  checked  randomly  for
tightness and  corrosion.  The  depressions  in   the  bottom  and  the
areas  around  or   under  roof supports  and  pipe-coil  supports  also
should be checked  visually.

Concrete  Tanks.    Concrete  tanks  represent  a   small  percentage  of
hazardous waste tanks  that are  currently in use.  Concrete,  however,
offers  many  advantages  as   a  tank   construction  material.    For
example,  corrosion   protection  is   not  required   although   some
chemicals  do  attack   concrete  and  protective  coatings   may   be
necessary.   When   properly  constructed,  the  risk   of  leakage  in
concrete tanks is  minimal.

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                                  OSHER Policy Directive No. 9483.00-1

                              4-39

Proper design and  construction  of concrete tanks is  critical  in the
storage  or  treatment  of hazardous  waste.   Leakage  control  is  of
major  importance  in concrete hazardous  waste tanks.   The following
factors may cause concrete tanks to leak:

o    Concrete permeability which allows the passage  of water;
o    Concrete cracks;
o    Construction joint cracks and defects; and
o    Chemical attack.

Cracks  in  concrete do  not  typically  lead  to  structural  failure,
however,  cracks  in  addition to  voids  in concrete  structures  can
Induce  leakage  in  a concrete tank.  Cracks in aboveground, ongrbund
and inground tanks can be detected by  visual  inspection.   The extent
of  cracking  can  be  made more  obvious  by  spraying  the  tank  with
water.  When the overall  surface  has  dried,  the cracks  will  be  more
prominent.   Temperature   changes  can  also expand  and   contract  the
concrete,  thereby  creating   stresses  which  may  possibly  lead  to
cracking.

Factors that affect the durability of concrete include:

o    Freezing and thawing;
o    Chemical attack;
o    Abrasion;
o    Corrosion of reinforcement; and
o    Chemical reaction of concrete aggregate.

For  the  purposes  of inspection  of  hazardous waste  concrete tanks,
chemical  attack  is  the  most prominent  concern.  All other  effects
can generally be prevented.

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                                       OSWtR Policy Directive No. 9483.00-1

                                   4-40

      Temperature  effects  (i.e.,  freeze-thawing) can be prevented  via air
      entrainment  of   admixtures  and  proper  design  of   concrete  mixes.
      Concrete  tanks  are  not  as  exposed   to  the  weather  as   are  other
      structures,  such as   roadway  bridges  or  airport   pavements.   For
      inground  tanks,   the surrounding  earth actually  acts  as  insulation,
      thereby offsetting the  effects of temperature change.

      Various  coatings  aid   in  preventing   corrosion of  reinforcement and
      chemical  reaction of concrete aggregates  is rare.*

      In  summary:   when conducting inspections  and  determining  inspection
      frequencies  for  concrete  tanks,  several  characteristics of concrete
      must be  considered:

 o    Concrete  is  susceptible to  freeze-thaw cracking and  deterioration  if
      not properly air entrained;

 o    If   not  made with  sulfate-resistant  cement,  concrete  is   subject  to
      attack by nearly all sulfate salts;

 o    Concrete  is  susceptible to  attack  by  many chemicals,  including  alum,
      chlorine,  ferric chloride,  sodium  bisulphate,  sulfuric  acid, and
      sodium hydroxide; and

 o    Concrete  may be  permeable  to some  liquids.

 The  American  Concrete  Institute  (ACI)   Manual  of  Concrete   Inspection
 includes  information  on inspection  fundamentals,   testing of  materials,
 sampling, and  inspection  before,  during, and after  construction.
Information  excerpted  from  "Analysis  For  Revised   Hazardous  Waste  Tank
System Standards," USEPA,  March 20,  1986.

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                                       OSWER  Policy  Directive  No.  9483.00-1

                                   4-41

G)   Ancillary Equipment Assessment

For  assessing  the   Integrity  of  ancillary  equipment  the   practices
described  in  API,  "Guide  for Inspection of  Refinery Equipment,  Chapter
XI - Pipe,  Valves  and  Fittings,"  Second  Edition,   1974,  may  be  used,
particularly  Section  11.9,  for "procedural  guidelines."   Inspections  may
be conducted either while equipment is  in operation  or while  equipment is
shut down.  The API,  "Guide  for  Inspection of Refinery Equipment,  Chapter
XI - Pipe,  Valves   and   Fittings,"   describes  procedures   for   these
Inspections.

While  equipment  is   in  operation,  piping,   valves  and  fittings  can  be
visually   checked   for  leaks,   misalignment,   integrity  of   supports,
vibration,,  external  corrosion,   accumulation  of  corrosive  liquids,  or
fouling.   Thickness  measurements  can  be  calibrated  via  ultrasonic  and
radiographic  inspection.   Non-destructive  inspections for  hot-spots  (for
pipes operating at  temperatures  in excess  of the design  limit  or in  the
creep  range)   and  of  underground  piping  (which   is  usually  only  spot
inspection  for  external  corrosion) and review  of  previous  inspection
records   can   facilitate   determination  of   the    system's   structural
integrity.

While  equipment  is  shut  down, visual   inspections   of gaskets,  flanges,
valves,  and  joints   can  be  conducted  for  corrosion,  erosion,  fouling,
cracks, misalignment,  vibrations,  and  hot  spots.   Thickness  measurements
and  pressure  tests  to determine  tightness  can be  performed as  well  to
determine   structural  integirty.    See  API   "Guide   for   Inspection  of
Refinery   Equipment,  Chapter  XI  - Pipe,  Valves  and  Fittings,"  Second
Edition,  1974, (Section 11.9) for details on  these  procedures.

H)   Assessment Schedule

Section 264.19Ka)  of  the  regulations  requires  that the  assessment  must
be  conducted  by  January  12,  1988  for  existing  tank systems  or within

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                                                     cy Directive No. y4oj.Gu-i

                                        4-42

     twelve months after the date  that  a. waste was classified as hazardous  by
     EPA,   for  those  systems  that  store  wastes   that  were  not   listed   or
     otherwise  classified as  hazardous  at the  time of promulgation (July  14,
     1986).

     I)    Leaking or  Unfit-For-Use  Tank  Systems

     Section 264.19Kd)  of the regulations requires that  if a tank system  is
     found  to be  leaking or  unfit  for  use as  a  result of the assessment,  the
     owner  or   operator of   that   system  must   comply  with  Sect.  264.196,
     "Response  to leaks or spills  and  disposition of leaking or  unfit-for-use
     tank  systems."  That section  of  the  regulations  is  discussed   in  Section
     11  of this  document.   In brief,  the  regulations require  that the .tank
     .system be  removed  from  service  immediately,  that the  leakage   be  stopped
     or  contained,  and  that  the  tank  system  be  repaired  and  provided  with
     secondary  containment  before being  put back  into use.

                         4.2  SUMMARY OF MAJOR POINTS

     The  following  summarizes  the information  covered  in  this  section  and
should be  used  to assure the  completeness of  a  Part 8 permit application.

     o    Is  the  independent,   qualified,   registered  professional  engineer
          currently registered  in the  state(s)  where the tanks  are  located?
     o    Has the engineer  reviewed and  certified  the written assessment?
     o    In the written assessment,  have  the following issues  been  addressed?

     NEH TANK SYSTEMS

          Design standards  for  tanks  and ancillary equipment.
          Hazardous characteristics of  the waste.
          Design or operational measures to  protect underground  tanks  against
          vehicular traffic.
          Design considerations to  ensure that:
               tank foundations will  maintain full  tank load;

-------
                                            OSHER  Policy Directive No. 9483.00-1

                                        4-43

               anchoring to prevent  flotation  and  dislodgment;
               tank, systems will  withstand  frost heave.
          Written  statements  on  file  at  the facility  by persons  certifying
          design, installation,  repairs.

     EXISTING.  USED.  REUSED TANK SYSTEMS

          Written  assessment  reviewed  and  certified   by   an   independent,
          qualified,   registered   professional   engineer  that  attests  to  tank
          system's integrity.
          Tank  system assessment must  be  conducted by  1/12/88 and include:
               Design standards;
               Hazardous characteristics  of  the  waste(s) that  have been  and
               wll1 be handled;
               Documented  (or  estimated  If documented not available)  age  of
               tank system;
               Results  of  leak  test  or other  inspection:   for non-enterable
               underground  tanks—a leak  test.   For  other  than non-enterable
               underground  tanks  and  for ancillary equipment—a  leak test  or
               other   integrity  examination  certified   by   an   independent,
               qualified, registered professional  engineer.
          Tank  systems  that  store  or  treat  materials  that  become  hazardous
          waste subsequent to July  14,  1986 must  conduct  the assessment within
          12 months after the  date that  the  waste  is defined as  hazardous.
          If the  assessment  indicates  that a tank  system is  leaking or  unfit
          for  use,  the  requirements of  Sec.  264.196,  "Response  to  leaks  or
          spills   and disposition  of  leaking or  unfit-for-use  tank systems"
          must  be followed.
In  addition,  see Appendix  A,  "Completeness Checklist,"  to verify  compliance
with the requirements of this section.

-------
                                            OSWER Policy Directive  No.  9483.00-1

                                        5-1

         5.0  DESIGN AND INSTALLATION OF NEW TANK SYSTEMS OR COMPONENTS
    In order to  evaluate  the  adequacy of a tank  system to hold  hazardous  waste
for  Its  Intended  lifetime,  the  Environmental  Protection  Agency  (EPA)   must
obtain  sufficient  information  on   the   tank   system's   design.    Thus,  the
following subsections  describe  the  tank system design  information  requirements
for  a permit  application.   Sub-section  5.1  discusses  tank  dimensions  and
capacity; Sub-section  5.2  discusses  tank  ancillary equipment  specifications;
Sub-section  5.3   discusses  tank  system  diagrams;   Sub-section  5.4  discusses
corrosion protection equipment;  Sub-sections  5.5  & 5.6 discuss  installation  of
new tank systems;  and  sub-section  5.7 addresses  major  issue  points that should
be addressed in the application.

                    5.1  DIMENSIONS AND CAPACITY  OF  THE TANK

    Citation

    Information on  the dimensions  and capacity  of a tank must  be  included  in
Part B of the permit application,  as specified  in  40 CFR:

             Sec.  270.16(b), dimensions and  capacity of each tank.

    Guidance

    Information about  tank  dimensions  and capacity is required for  Part  B  of
the  permit  application,   as  delineated  in  Sec.  270.16
-------
                                                          i receive  Nu.  y4aj.uu-i
                                        5-2

    It  is  advisable  that  a   general,   written   description   of   each   tank
Incorporate the following  information  (easily  provided  in  tabular form):

    o    Shape of tank, (i.e.,  spherical,  cylindrical, etc.);

    o    Material(s) of construction;

    o    Inside diameter or perimeter dimensions,  in feet and inches  (or
         alternatively, in metric units);

    o    Outside height and length,  in feet and  inches;

    o    Nominal capacity, in  U.S.  gallons;

    o    Maximum capacity, in  U.S.  gallons;

    o    Wall  thickness,  in inches  or fractions of inches (bottom plates,
         shell plates and  roof,  or shell  only,  as applicable);

    o    Description of appurtenances  (type,  size, and  location for  all
         nozzles, manholes, and  draw-off s); and

    o    Stairways, supports,  fittings,  platforms,  and  walkways.

    Each  general   tank  description  should  be  accompanied  by detailed  scale,
cross-sectional plans, and elevation  drawings  that specify  all   dimensions  of
the tank.   Illustrative examples  of such drawings can be found  in  Figures 5-1
through 5-3.   A tank  manufacturer.1 s  specification  sheet should be  included
with  the   permit  application.   In  addition,   a  gauge  chart  that  indicates
capacity per  foot  of length  (or height)  in a  tank with  a particular  diameter
should  be  provided,  if   available.    For an   Irregularly   shaped  tank,  the
manufacturer should provide a  capacity table that is specific to  the tank.

-------
                                       5-3



                                   Plgurs  5-1

                               Tank Dimensions
                            CLEANOUT
 DRAIN-LINE
 CONNECTION
PLAN
                                       /'OVERFLOW LINE  /^
                                       '--CONNECTION     [  COVEB
                                                         I  PLATE
                                                            \
VENT  LINE
CONNECTION

   THIEF-HATCH  CUTOUT
                                             LINh
                                        CONNECTION
PROFILE
.VENT-LINE
 CONNECTION
                              PIPE-LINE
                              CONNECTION
DOME
  ,       FILL-LINE
         CONNECTION
                     OVERFLOW-LINE
                      CONNECTIONS
                   _._g	5.
                     ..
                    °
                              WALKWAY),
                               BRACKET11

                               LUGS    i.
             i'
                          13" I 13"

                 CLEANOUT :«1 PIPE-LINE
                         I~N—-—.-IQQNNECTION
             [DRAIN-LINE,    •  'I .>
             I CONNECTION
                  \4 ' 	

                                                     2312"BC

                                                     163''HOLES
                                                  26"
                                                         f6"
                                                              I
                                                   TYPICAL DOME DESIGN
                                                                 114"MIN
                                                          9/16"
                                                                   4°"
                                                             c
                                                             fl.

                                                     DETAIL OF WALKWAY
                                                       BRACKET  LUGS
     FIGURES ARE FOR ILLUSTRATIVE PURPOSES ONLY. THEY ARE NOT INTENDED FOR USE AS

     CONSTRUCTION DRAWINGS.

-------
                                    Flgur* 5-2
                            Tank Dimensions (ConU
                                                           PLAN
    3' FRP FLANGED  NOZZLE
    CONICALLY GUSSETTEO
ZINC PLATED TIE
DOWN LUGS(TYP)
                                          31 FRP  FLANGED NOZZLE
                                          CONICALLY GUSSETTED
                                          CSIPHON)
  3'  FRP FLANGED NOZZLE
v-v
\












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_ —
                                          24' TOP  HINGED MAN WAY W/COVER
                                             HOLD  DOWN CLAMP
  24* SIDE FLANGED  MANWAY  W/COVER
  24' NEOPRENE GASKET
  7/8'x4'  LG. ST.  STL.  BOLTS, NUTS,
  WASHERS

  24' TOP HINGED  MANWAY W/COVER
      HOLD  DOWN CLAMP
                                                   PROFILE
                                             0.250'  SHELL  THICKNESS  ~ C
                                             REMAINDER I N C L U C I M G C I S~H
                                                  7/8'x4f LG. BOLTS, NUTS,

                                                 3" FRP  FLANGED NOZZLE
                                                ''CONICALLY  GUSSETTED  (SIPHON)

                                                • 8" TYP.
24' SIDE FLANGED MANWAY W/  COVER
24' NEOPRENE  GASKET
                           FIGURES ARE FOR ILLUSTRATIVE PURPOSES ONLY. THEY ARE NOT INTEND
                           FOR USE AS CONSTRUCTION DRAWINGS.

-------
                                    5-5
                                Figure 5-3
                         Tank Dimensions (Cont.)
           MANWAY
4' STEEL ATMOSPHERIC  VENT
                   \     1 4 GAUGE
                          11' 2"
                                       2'OF  HIGH  DENSITY  RUBBER
                                       INSULATION TO BE.APPLIED
                                       TO TANK TOP  IN FIELD
                                              PLAN
                                        -8 GAUGE STEEL
                                        3' FLANGED NOZZLE
                                       TANK CLEANOUT
 I6'x20' IN  SWING OUT FLANGED MANWAY COVER W/16'x20'
 NEOPRENE  GASKET, 7/8'26  ST. BOLTS, NUTS &  WASHERS
                                              PROFILE
24* TOP  HINGED  MANWAY  W/COVER
16'x20'  GASKETTED DUAL  CUTOUT
EMERGENCY  VENT IN  MANWAY

'HOLD DOWN
                                       TANK WALLS (8-14 GAUGE  A31  STEED
    TANK TO BE PAINTED WHITE
    TO REFLECT  HEAT

-------
                                                      i receive  ho.
                                    5-6

A)   Aboveground/Onground/Inqround Tanks

Aboveground/onground/inground  steel   tanks  can  be  either  preconstructed
(fabricated  by  the  manufacturer  in  a   variety  of  standard  sizes   and
purchased  ready-to-1nsta!1)  or   field-welded   (constructed   onsite  with
rolled  steel  plates  and  welded  together,   according  to  predetermined
specifications).  Preconstructed  steel tanks  are generally less than 12 to
15 feet in diameter;  tanks that have  diameters  greater than 12  to  15  feet
are  usually  field-welded.   Fiberglass-reinforced  plastic  (FRP)  tanks  are
always purchased ready-to-use from the manufacturer and are available  in a
wide variety of shapes, dimensions, and capacities.

Preconstructed  tanks  are  usually  delivered  with  a  detailed  specification
sheet  from  the  tank  manufacturer  that  describes  not  only  all  tank
dimensions  and  capacity  but  any  other unique  tank  design   features  as
well.   The  specifications   sheet  should  include   maximum   and  nominal
capacities, especially for  conical  or rounded-top tanks and any other  type
of  tank  where  actual  liquid   storage  capacity  does   not   necessarily
correspond  to  total  tank   volume.    The  specification   sheet   should  be
submitted with the permit  application.

Field-welded  steel   tanks  are  built  to  engineer's  and/or  manufacturer's
specifications   onsite.    Tank   dimensions   are  usually  determined   by
calculations  that  take  into  account  the  required  volume   of  storage
capacity  and  the  available  area for  the  tank.   Calculated  dimensions,
however,  may  not represent  actual,  final field-welded  dimensions   of  the
tank,  due to  variations  in design  or construction  techniques,  irregular
welding of seams,  and other variables resulting  from field  fabrication.
All  field-welded tanks should be  "strapped" (accurately  field measured)
following  construction,   to determine  the  actual  final   dimensions   and
capacity  of  the  tank.   Strapped measurements  can  then  be compared  with
design specifications to determine if sizable changes  In  the  dimensions of
the  tank  are   present  following  field  fabrication.  Hherever  possible,
field-welded  tanks   should  be  described  using  dimensions  and  capacities

-------
                                        OSWER Policy Directive No.  9483.00-1

                                     5-7

determined by  field measurement  following  construction.   A depth  versus
capacity  chart should  be  made for  a  field-welded  tank  soon after  it  is
installed.

Details  concerning  the wall  thickness  of  aboveground/onground/inground
steel  tanks   should be explicitly  provided  in  the  Part   B  application.
Sample recommendations  may  be  found in Table  5-1.   The  dimensions  in the
table do  not  reflect any allowance for corrosion or for  variations in the
density of tank contents.

In certain aboveground/onground/inground  tanks,  thickness  may  be  variable
with  height  along  the  sides  of  a tank,  with  the  lower   cross  sections
requiring greater thickness than the upper ones.   This tank  design  mus-t  be
noted  in  the  permit  application.   Such  an  approach  to  tank design  is
referred  to  as "graduated  wall  thickness"  and  is  frequently  employed  in
shop-fabricated,  reinforced-plastic  tanks.   Table  5-2 outlines  recommended
minimum  thicknesses for graduated  wall,  aboveground  reinforced-plastic
tanks.  A safety factor of 10 is built into these recommendations.

B)   Underground Tanks

Underground tanks  (steel or  FRP)  are usually preconstructed tanks  built  to
a variety  of  predetermined  capacities  and  dimensions,  although  tney  can
also  be  made-to-order   to fit  customer  specifications.   The  manufacturer's
specification  sheet  for such  a  tank  should  be   included  as part  of  the
permit application.

In particular, detailed dimensions  and drawings  should be  provided  for FRP
tanks, which may be irregularly shaped or ribbed and  difficult  to  describe
accurately without  a  scale  drawing.   Following  emplacement  of  FRP  tanks,
field capacity testing  is recommended,  since large FRP tanks  are not  rigid
and  may  "slump"  or  distend  once tank  installation  is  complete.   Slumping
may  cause  uneven  distribution  of tank volume, producing  a  discrepancy  in
the height-to-volume ratio specified in the  gauge table.

-------
                                            OSWER Policy Directive  No.  9483.00-1


                                        5-8


                                   TABLE 5-1

          VERTICAL, ABOVEGROUNO STEEL TANK  MINIMUM WALL  THICKNESSES*]}


                               THICKNESS (INCHES)
Capacity
(Gallons)
1 ,100 or less
Over 1 ,100

Shell
0.093
0.167
Carbon Steel
(2)
Bottom
0.093
0.240

Top
0.093
0.123
Sta
(2)
Shell
0.086
0.115
inless Steel
Bottom Top
0.086 0.086
0.158 0.086
Source:     Underwriters Laboratory,  Inc.,  UL  142,   "Steel  Aboveground  Tanks
            for Flammable and Combustible  Liquids"  (1985).
           HORIZONTAL, ABOVEGROUND STEEL TANK MINIMUM HALL THICKNESSES

                               THICKNESS  (INCHES)
Capacity U.S.
Gal Ions
500 or less-
551-110
1,101-9,000
1,101-35,000
35,001-50,000
Maximum Diameter
Inches
48
64
76
144
144
Mi nimum Metal
Carbon Steel
0.093
0.123
0.167
0.240
0.365
Thickness, Inches
•Stainless Steel
'0.071
0.086
0.115
0.158
0.240
Source:    Underwriters Laboratory,  Inc.,  UL 142, "Steel Aboveground  Tanks  for
           Flammable and Combustible Liquids"  (1984).

NOTES: (1) Dimensions  are  exclusive  of  corrosion  allowance  or variations  in
           density of tank contents.

       (2) For a  tank more  than  25 feet  in  height,  all  parts of  the  shell
           located more than 25  feet  below the top  edge of the shell  shall  not
           be less than 1/4 inch.

-------
   OSWER Policy Directive No. 9483.00-1
5-9









































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-------
                                                  Policy Directive No.  9483.00-1

                                        5-10
                5.2  DESCRIPTION OF FEED SYSTEMS,  SAFETY CUTOFF,
                      BYPASS SYSTEMS, AND PRESSURE CONTROLS
    Citation
    A description of  the  equipment  used  in the transfer  of  waste material  to
storage  tanks  at  the facility  must be  included  with  Part  B  of  the  permit
application.  This ancillary equipment includes tank venting devices  and spill
and overfill prevention devices,  as  specified  in 40 CFR:

    Sec.  270.16(c),  description  of feed  systems,  safety cutoff,  bypass
    systems, and pressure controls (e.g.,  vents).

    Guidance

    Sec.  270.16(c)  requires Information about  equipment  associated with  the
transfer  of waste into  the tank and  the  venting  of  vapors  from  the  tank to
allow  EPA  to  evaluate  the  capability  of  a  system  to  meet  construction
guidelines  and   standards.   These  guidelines  and  standards  are designed  to
prevent:

    o    Explosion or implosion of tanks;

    o    Fire;

    o    Emission of hazardous  vapors; and

    o    Spillage of  hazardous  waste resulting  from overfilling  vessels  or
         drainage from transfer hoses.

    All  Information  required to  make  such an  evaluation should  be  available
from the  tank manufacturer.  The  description  should Include a statement as to
whether or not the following are used:

    o    Welded flanges and joints

-------
                                        OSHER Policy Directive No. 9483.00-1

                                    5-11

o    Sealless valves

o    Sealless or magnetic coupling pumps

o    Piping shut-off devices.

The description should address the following system components:

A)   Feed System

Many spills  occur at  storage  tank, facilities during  transfer  of material
because  of  overfilling  the  tank,  forcing  waste  out  of vent   lines,  or
draining  the  waste  remaining in  the  delivery  tube  during  disconnection
procedures.    In  underground  tanks,   the  fill  pipe  may  actually  rupture
below  the  soil   surface  because  of  improper  support  and/or  excessive
vibration, resulting in undetected discharge of material  directly into the
surrounding  soil.   Use  of  proper  equipment and  operating  practices  can
prevent transfer spills of this nature.   The equipment -used to  prevent the
overfilling  of vessels  consists  of  instrumentation  designed   to  monitor
continuously the  liquid-level  in the  tank, an alarm  system,  and  a  safety
cutoff  or  bypass  that  is  triggered  when a  "high-level"  condition  is
reached.  This equipment is described  below.

     1)   LEVEL SENSORS

     A  liquid-level   sensor  generally  falls  into one  of  the  following
     classifications:

          o    Float-actuated devices
          o    Displacer devices
          o    Hydrostatic-head sensors
          o    Capacitance sensors
          o    Thermal-conductivity sensors
          o    Ultrasonic devices
          o    Optical devices

-------
                                             cy  u\ receive  NO.  y4oj.GG-l

                               5-12

To provide  warning of  the  liquid-level,  some  aboveground/onground/
inground tank  systems  use two  level  sensors:   one  for high  liquid-
level (95 percent  full)  and  one  for  high,  high liquid-level  sensing
(98  percent  full).   Characterization  of  liquid-level  sensors,  as
discussed  in  Section   9.0,   will   aid  in   the   permit   application
description.

2)   ALARM SYSTEM

The  liquid-level  sensor  should  be  tied   into  an alarm  system  that
notifies the  operator  of  a  high-level  condition.   The  alarm  system
may  be  either visual or audible,  or  a combination  of  the  two.   An
audible  alarm is  generally  preferable  because  it  will  alert .the
operator  without  continual   visual  monitoring.   Individual  lights,
however, may be used 1n  conjunction  with an audible  alarm  to Indicate
in which tank a high liquid-level  condition exists.

3)   LIQUID TRANSFER

The  manner  in which liquid  is admitted  to  a tank as part  of  a feed
system  can  cause  turbulence,  resulting  in   foaming,   release  of
hazardous vapors, or generation of  static charge  in  the  waste.   This
is  particularly   likely  if  the  fill   pipe empties   above  the  waste
liquid's  surface;  therefore,  a  fill  pipe  entering a  tank  should
terminate  within  three  inches   of  the   bottom  of  the   tank.    A
deflection  or  striker  plate  should  be installed  beneath  the opening
of a fill  pipe that terminates near  the  bottom of  a tank.   Without
such  a  plate,  the tank  shell may  be subject  to corrosion  In  this
area.   Proper support  must   be  provided   to  prevent  vibration  that
could   lead  to  breakage  of  the   fill  pipe,   resulting  in  direct
discharge of material  to the soil.

Connections for all tank openings,  including  the fill pipe,  should  be
liquid-tight,  properly  identified,  and   closed  when  not  in  use.

-------
                                   OSWER Policy Directive No.  9483.00-1

                               5-13

Openings  designed  for  combined  fill   and  vapor  recovery should  be
protected  against vapor  release,   unless  connection  of  the  liquid
delivery  line  to the fill  pipe simultaneously  connects  the  recovery
line.   A  number of  variations  on  liquid   delivery/vapor  recovery
systems  are  available,  and  a  description   of  the  type  of  system
employed in each tank is required.

A feature  commonly  included  in  the discharge pipe  of  a  suction  pump
is  a check-valve  system  to  prevent reversal  of  flow.   There  are
three basic designs for  check valves:   swing,  lift,  and  tiIting-disk.
Check valves  are available  in  a  wide  variety of  sizes  and  materials
of construction.

Transferring hazardous  materials  into  or  out of  storage tanks  also
requires  the  use  of  tight coupling connections which  can  withstand
the  temperature,  pressure,  and chemical  compatibility  requirements
demanded  of  them.   Couplings  may  be   described  in  terms  of  their
method of connection and materials  of construction.

The  description  of  the  transfer   piping  and   any  associated  check
valves and couplings should include the  following information:

     o    Material of construction  for  piping;

     o    Distance of fill  line  offset  from tank, if applicable;

     o    Distance from  tank bottom to  termination of fill pipe;

     o    Method of attachment and  support  of fill pipe;

     o    Liquid-delivery/vapor-recovery system;

     o    Type  and  location of any  check  valves.  Including  size
          and materials  of construction; and

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                                    5-14
          o    Type  of  coupling  connections,   including   size  and
               materials of construction.

8)   Safety Cutoff or Bypass Systems

In addition to  interfacing  with  an  alarm system, the  liquid-level  sensing
devices  should  be  directly connected  to an  automatic  safety  cutoff  or
bypass  system.   These  control  systems  are  designed  to  receive a  signal
from the  liquid-level  sensing  device  when it reaches a  preset  high level.
The  systems  then   automatically   transmit   a   message  either   to  the
tank-loading pump  to deactivate (safety  cutoff) or  to  a  system  equipped
with  various  flow-control   valves  and  pumps   to divert flow  to  another
storage  tank,  (bypass).   For aboveground/onground/inground  tanks,  a manual
emergency  overflow system  may also  be  provided  in  case  the  automatic
control   system   should  malfunction.    An   overflow   to   the   secondary
containment system must exist in  case  the  entire  system  (tank  and  overflow
tank) is filled to capacity.  This overflow  point must be visible.

The  description '  of each  safety  cutoff  or   bypass  system  employed  at  a
facility  should  include the type of  liquid-level  sensing  device  and the
method by  which the signal  is  transmitted from  it  to the actual cutoff or
bypass   mechanism.    This   transmission  is   generally  accomplished   by
electrical or  pneumatic methods,  because of  their  respective  adaptability
to remote  operation;  however,  mechanical devices  may  also be  employed.
Types of  valves,  pumps,  and overflow  vessels  should be described in detail
in the facility summary.

C)   Pressure  Controls (e.g.. Vents)

Most storage tanks are equipped with pressure-relief  mechanisms  to prevent
physical damage or  permanent deformation  of  the  tank due  to exceedance of
normal  operating  pressure.  Addition  of wastes to  a  tank,  as  well  as
expansion   and   evaporation   due    to  thermal   changes,   results   in
"outbreaking"  (pressure-relief)  of  vapor  from  the  tank.   The  required
venting  capacity   for   a   tank   must  exceed   the   sum  of  the  venting

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                                        OSHER Policy Directive No.  9483.00-1

                                    5-15

requirements for addition of  wastes  into the tank and for expansion due to
thermal  effects.   "Inbreathing"  (vacuum relief)  occurs when  wastes  are
removed  from  a tank  or  when  the  gaseous  volume decreases due  to  thermal
effects.  Exposure to heat or  fire can result in  rapid  pressure  Increases,
making additional  emergency venting capabilities necessary.

Construction specifications designed  to meet outbreaking  and  inbreathing
requirements  are   dependent  upon  a  number  of  variables   that  must  be
Included in the description of  the pressure controls called  for in 40 CFR
270.16(c).   These  design and  operational  variables  and their  respective
contributions  to vent  selection  and  arrangement should  be described in the
permit application.  Such variables include:

     1.   Flash  point  and other  relevant  characteristics   of  the
          contained liquid or  solid waste;

     2.   Maximum design pressure and capacity of each tank;

     3.   Maximum inflow and outflow rates;                         ,

     4.   Roof design and attachment mechanism to tank shell;  and

     5.   Tank heating or cooling system, if applicable.

The   American   Petroleum   Institute's   (API)   Standard   2000,   "Venting
Atmospheric and  Low-Pressure  Storage  Tanks"   (1982),  provides  extensive
Information on vent design.

Vent  design,  Including  emergency venting  capabilities  and  safety  relief
devices, must be  described  in  the permit application.   A variety  of vent
types  are  available,  and a description  of  the  type  employed on each tank
at  the  facility  should  be  provided.   The following  discussion  of  vent
types should help in determining the type used on tanks.

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                                    5-16

Normal  venting  may be  accomplished  by  a  pilot-operated  relief valve,  a
pressure-relief valve,  a  pressure  vacuum (PV) valve, or  an  open vent with
or without a flame-arresting device.

A pilot-operated relief valve is designed so that the main valve will  open
automatically and  protect the  tank  In  the  event  of failure  of the  pilot
valve diaphragm or other essential  functioning devices.

A  pressure-relief   valve   is  appropriate   for  tanks   operating   above
atmospheric  pressure.   In  cases  where  a  vacuum can  be created within  a
tank, vacuum protection may be required.

PV valves  are  recommended for  use  on  atmospheric  storage tanks in  which
material  with  a flash  point  below 100'F  Is stored  and for  use on  tanks
containing material that is heated  above Its flash  point.

Open vents with a flame-arresting  device may be used in  place  of PV  valves
on tanks  in  which  material  with a  flash point below 100"F is stored  and on
tanks  containing  material  that is  heated  above  its  flash  point.   Open
vents  without   a  flame-arresting  device  may  be used  to provide  venting
capacity for tanks in which material  with  a flash  point  of  100°F or  above
is  stored,  for  heated tanks where  the storage temperature  is  below  the
flash point, and for tanks with  a  capacity of less  than 2,500 gallons.

Emergency venting may be accomplished  by the use of:

     o    Larger or additional open vents;

     o    Larger or additional PV  valves or pressure-relief valves;

     o    A gauge  hatch that  permits  the manhole cover  to lift under
          abnormal Internal  pressure;  and

     o    A  manhole   cover   that   lifts  when  exposed  to  abnormal
          internal pressure.

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                                        OSHER Policy Directive No.  9483.00-1

                                    5-17

The  location  of  pressure-relief vents  and  the   point  of  vapor  release
should  be  detailed in  the  description of  venting devices.   The  point of
vapor release must be noted by the permit applicant so that  EPA  may assess
the  potential  safety  hazards  resulting from discharge of  dangerous vapors
in a confined  area, fire  hazards,  and possible blockage of  vent openings.
Items to consider in discussing the  point of release include:

     o    Can released vapors  be trapped by adjacent obstructions?

     o    Are  flammable  vapors released at a  sufficient height  above
          ground  level  to prevent  inadvertent  ignition (e.g.,  by  a
          person with a lighted cigarette)?

     o    Can  the  opening become blocked from weather,  dirt,  Insects
          nests, etc.?

     o    Where  is  the vent  discharge  located relative to the  fill
          pipe?

A  brief discussion  of the piping  configuration   of  the  vent  system also
should be provided and important points to discuss include:

     o    Are  there  any  low  points,  bends,  elbows,   etc.,  where
          condensed liquid may  collect  and restrict vapor  release and
          create a pressure increase in the vessel?

     o    Do manifolding  or "dead  ends" exist where  mixtures  in  the
          flammable range  may be trapped, creating the  potential  for
          explosions or fires?

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                                           OSWER  PoiiL.y  Directive  No.  9483.00-1

                                        5-18

           5.3  DIAGRAM OF PIPING, INSTRUMENTATION, AND PROCESS FLOW

    Citation

    The owner  or  operator of  a tank  system  must provide a diagram(s) of  the
piping, instrumentation,  and  process  flow  as  required  in:

    Sec.   270.16(d),   (provide)   a  diagram   of piping,   instrumentation,   and
    process flow for  each  tank  system.

    Guidance

    The intent  of the Sec. 270.16(d)  requirement is  to ensure that  each  tank
facility is designed  in  a  manner that minimizes  the  possibility  of  releasing
waste to the  environment.   Such a design would, for example:

    o    Minimize   piping  lengths,   crossovers   over   other   equipment,
         joints, and  couplings;

    o    Have  adequate  instrumentation,   such   as   level   alarms,   flow
         meters,  shutoff  valves,  etc., to monitor and  react  to  changing
         liquid and pressure  levels;  and

    o    Have process  flows  that  separate   incompatible materials,  con-
         tain   appropriate   capacity    and    venting,    have   adequate
         line-cleanout capabilities,  and minimize   the need  for disconnec-
         tion.

    Diagramming of a tank system's  piping,   instrumentation,  and  process  flow
can  range  from  a detailed  schematic  drawing of all  relevant  tank  system
components  to  a   complex  blueprint   drawn   to scale.   Relevant  tank  system
components that should be shown on a  diagram  are:

    o    Fill  lines (inlets);

    o    Draw-off lines (outlets);

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                                            OSWER Policy Directive  No.  9483.00-1

                                        5-19

    o    Piping,   including   directional    changes   (inside    diameter,
         materials of construction,  etc.);

    o    Pumps (type, horsepower,  capacity,  etc.);

    o    Flow meters (capacity);

    o    Gauging (measuring) lines;

    o    Level alarms;

    o    Valves (type);

    o    Vents (diameter, materials  of construction);

    o    Leak-detection  devices (type);

    o    Manholes and other openings;

    o    Floating suction arms, if any;

    o    Drainage; and

    o    Corrosion-control system  (type).

    Enlarged, detailed   drawings  of  complicated  portions  of  a  system may  be
useful  to emphasize relevant features  (see  Figure 5-4).

    Accompanying  documentation with   a  tank  system  diagram  might   explain
briefly why particular  instrumentation was   selected.  Documentation  might  also
contain mass  balance equations and  a description  of any complicated  process
flow aspects, including  the cleaning of a  tank  system if new  wastes are  added
that may  be  incompatible.   Figures  5-5  and 5-6 contain examples  of schematic
diagrams for underground and aboveground tank facilities, respectively.

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                                5-22
                           Figure 5-6
             Aboveground Tank System Connections
FIGURES ARE FOR ILLUSTRATIVE PURPOSES ONLY, THEY ARE NOT INTENDED FOR USE AS
CONSTRUCTION  DRAWINGS.

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                                                   c/iicy ^receive MO. 94dJ.OU-i


                                        5-23


                       5.4  EXTERNAL CORROSION PROTECTION


    Citation


    Information  on   external   corrosion  protection  for   tanks   with  metal

components or metal ancillary equipment Is required from facilities  that store

or  treat  hazardous  waste  and  must  be  Included  in  Part  B  of  the  permit

application, as specified in:


    Sec.  270.16(e),   Description  of  materials  and   equipment  used  to
    provide external  corrosion protection, as required under Sec. 264.192.


    Sec.  264.192(a)(f)   and  (g)  of  the  regulations  specifies   the  external

corrosion protection  measures and certification requirements.


                     5.4.1  Corrosion Potential Assessment.


    Citation


    For  a  tank  system  with  metal   components  in  contact  with  soil   or  with

water,   Sec.  264.192(a)  requires  that  the owner/operator obtain  an assessment

by  a  corrosion  expert  of  the  corrosion potential  of the  soil  environment

surrounding the system.   As this section states, the assessment must address:


    (1)  Factors affecting the  potential  for corrosion, including but not
         limited to:

         (A)  Soil  moisture content;
         (B)  Soil  pH;
         (C)  Soil  sulfldes level;
         (D)  Soil  resistivity;
         (E)  Structure  to soil potential;
         (F)  Influence   of  nearby  underground  metal  structures  (e.g.,
              piping);
         (G)  Existence  of stray electric current; and
         (H)  Existing  corrosion-protection   measures  (e.g.,   coating,
              cathodic protection).

    (11) The  type  and  degree  of  external  corrosion  protection  that  are
         needed to ensure the integrity of the  tank system  during  the use
         of  the  tank system  or component,  consisting  of  one  or  more of
         the following:

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                                        5-24

         (A)  Corrosion-resistant  materials   of   construction  such   as
              special  alloys,  fiberglass reinforced  plastic,  etc.;
         (8)  Corrosion-resistant  coating  (such  as   epoxy,   fiberglass,
              etc.) with  cathodic  protection (e.g., impressed  current  or
              sacrificial  anodes);  and
         (C)  Electrical   isolation  devices  such  as  Insulating  joints,
              flanges, etc.

    Guidance

    Accurate  information  must be  obtained  on  the  environment surrounding  a
metal tank  system  in  contact  with  soil  or water because  such  a tank system may
be  highly  susceptible to corrosion.    "A metal  tank  system  in  contact  with
water" pertains to  inground water  (high water tables) or  saturated soils.  It
does  not  typically   pertain  to  the  temporary  aftermath  of  a  rain   storm;
however,   if  after  a rain   storm  the  area remains  super   saturated  for  a
prolonged period of  time, then  precautions  should  be taken  to prevent  super
saturation  or  a corrosion assessment  must  be  performed.   A  corrosion  expert
should be  consulted   to assess  the corrosion potential,  as  quantitatively  as
possible, of  a particular environment.   EPA expects this corrosion  expert  to
be  a  person who,  by  reason  of his/her  knowledge of the  physical  sciences and
the  principles of  engineering  and  mathematics,  acquired  by a  professional
education   and   related   practical   experience,   is  qualified    to   provide
corrosion-control   services  for  metal  tanks  and/or   piping   in  contact  with
soil.

    The  National  Association  of  Corrosion   Engineers  (NACE)  is  developing  a
special  program to provide  industry,  government,  and  the general  public with a
system   of   recognizing   qualified '  personnel   in   the   field  of   cathodic
protection.   Scheduled for  implementation   in  early  1987,   the  certification
program will be based  on  the  experience of  NACE in accrediting and certifying
corrosion personnel and protective  coating  inspectors.

    Each  level of certification  will  have  specific   requirements  and  will
include  an examination   to  make  certain   that  the   applicant  fulfills   the
requirements.

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                                            OSWER Policy Directive No. 9483.00-1

                                        5-25

    Complete  details  of  this  certification  program are  available  from  NACE
Headquarters, P.O. Box 218340, Houston, Texas 77218 (317/492-0535).

    Independent,   registered    professional    engineers    with    appropriate
corrosion-protection  experience  with buried  or  submerged  metal   tank,  systems
may also  perform  the  corrosion potential  assessment.  The greater the accuracy
of  such  an  assessment,   the  more  appropriate  a  corrosion-protection  system
design wi11  be.

    Corrosive  deterioration   of   tank  material   may  be  either  general  or
localized.  General corrosion  appears  as  a uniform  loss of  surface  material,
whereas   localized  corrosion  results  in  a  non-uniform  loss  of  material.
Table 5-3 lists several  common forms of localized corrosion.   Table  5-4  1-ists
environments  that  may cause  corrosion.   This table lists environments that can
cause both  Internal and  external  corrosion.  The major  factors  that  Influence
external  corrosion of inground and underground tanks are soil characteristics,
such as resistivity,   the presence of chemical  constituents  (natually  occurring
or  leaked from the  tanks),  pH,  and moisture content.   Figures   5-7  and 5-8
show  some  of  the  major  Corrosion  mechanisms.    Concrete  structures  with
metal-reinforcing  bars (rebars)  may find  that the  rebars corrode under similar
environmental conditions.

    Each  of  the  soil  factors   listed  in  Sec.  264.192(a)  and shown in  Figures
5-7 and  5-8  describes the corrosion potential of the environment surrounding a
tank system.

    Figure 5-7 (top)   Illustrates a  potential  galvanic  corrosion  environment in
which  dissimilar   soil  conditions  exist  because  of the  use of  two  different
types  of backfill  material.    Figure  5-7  (bottom)  illustrates  an  anaerobic
region  near  the botton of the  tank,  caused by trapped  water  between the  tank
and backfill, which can lead to bacterial  corrosion.

    Figure 5-8 (top)   depicts galvanic corrosion caused by  dissimilar  metals in
an old tank installed near a new tank,  and in the piping and tank of the new

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                                        5-26


                                   TABLE 5-3

                      COMMON FORMS OF LOCALIZED CORROSION
            Type
                       Description
Bacterial corrosion
Contact or crevice
  corrosionbetween a metal

Erosion corrosion
Galvanic corrosion
Intergranular corrosion
Pitting corrosion
Stray current corrosion
Stress corrosion cracking
    Soils  or  water  that   become   oxygen-starved,
    I.e., anaerobic,  cause  this  form of corrosion.

    Occurs at the point  of  contact  or crevice
and a non-metal  or between  two metals.

    Moving fluid removes the protective surface film
    on a metal,  allowing corrosion  to occur.

    Occurs when  an electrolytic cell  is formed  in
    cases where  dissimilar  metals   are  electrically
    connected or  where  dissimilar   soil  conditions
    or differential aeration conditions exist.

    Selective  corrosion  at  the  grain  boundaries
    (microscopic) of a metal or  alloy.

    Formation of  shallow  depressions  or deep  pits
    (cavities of small diameter).

    Occurs  when  direct  electrical  currents   flow
    through metal.

    Corrosion accelerated  by residual  stresses  re-
    sulting from  fabrication operations  or  unequal
    heating and  cooling  of  structure.
Source:  New York  State  Department of Environmental Conservation,  "Technology
         for the  Storage  of  Hazardous  Liquids—A  State  of  the  Art  Review"
         (January 1983),  pp.  11-17.

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                                            OSHER Policy Directive  No.  9483.00-1
                                        5-27


                                      TABLE  5-4

                        ENVIRONMENTS THAT CAN CAUSE CORROSION
          Material
              Environment
Aluminum


Aluminum bronzes

Austenitlc stainless steels



Carbon and low alloy steels



Copper


Ferritic stainless steels
High strength alloy steels
(yield strength 200 psi
plus)

Inconel
Lead

Magnesium



Monel


Nickel

Titanium
Water and  steam;  Nad,  including  sea  atmospheres  and
waters;  air; water vapor.

Water and steam; H2S04;  caustics.

Chlorides,   Including   FeCl2,    FeCl3>   NaCl;    sea
environments;   H2S04;   fluorides;   condensing   steam
from chloride waters; acids.

HC1;   caustics;  nitrates; HN03; HCN;  molten  zinc  and
Na-Pb     alloys;     H2S;     H2S04-HN03;      H2S04;
seawater; water; distilled water.

Tropical    atmospheres;    mercury;   HgN03;   bromides;
ammonia;  ammoniated organics;  acids.

Chloride,   including   NaCl;    fluorides;   bromides;
iodides;  caustics; nitrates;  distilled water; steam.

Sea and  industrial environments;  water.
Caustic  soda  solutions;  high  purity  water  with  few
ppm oxygen.

Lead acetate solutions.

NaCl,  including   sea  environments;  water  and  steam;
caustics;   N204;   rural   and   coastal   atmospheres;
distilled water.

Fused  caustic  soda;   hydrochloric  and  hydrofluoric
acids.

Bromides; caustics; H2S04-

Sea environments; mercury; molten  cadmium;  silver  and
AgCl;  methanols  with   halides;   red  fuming   HN03;
    ; chlorinated or fluorlnated  hydrocarbons.
Source:  Adapted  from  V.R.  Pludek,  Design  and Corrosion-Control  (New  York,   NY:
         John Wiley and Sons, 1977).

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                                 Figure 5-7

                          Corrosion Mechanisms
                               Pavement
                                          Cathodlc Region
                                           (No Corrosion)
    Boundary
                              Pavement
                            Homogeneous Backfill
                                 StalTaik
                                Aerobic Region
                                   Cathode
                                (No Corrosion)
                               Anaerobic Region
                              With Bacterial Activity
                             f Anode (Corrosion) (+)

Excavation
Boundary
Old Soil
   FIGURES ARE FOR ILLUSTRATIVE PURPOSES ONLY. THEY ARE NOT INTENDED FOR USE AS

   CONSTRUCTION DRAWINGS.

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                                         5-29

                                     Figure 5-8

                           Corrosion Mechanisms (Cont.)
                                   Pavement
                       (No Corrosion) \;:3A
Old Soil
                                                                                      i
                                                                                      o
                                                                                      o
                                                                                      n
                                                                                      to
                                   Pavement
                                   Cathodic Region

                                   (No Corrosion)
                                                      ,
                                                      1       '    '"
Excavation
Boundary
                                                                                      O
                                                                                      c
o
o.

oc
IL1

5
      FIGURES ARE FOR ILLUSTRATIVE PURPOSES ONLY. THEY ARE NOT INTENDED FOR USE AS

      CONSTRUCTION DRAWINGS.

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                                                                P »  I l>w .  J T W _> . W s
                                        5-30

tank  system.   Figure  5-8  (bottom)  depicts erosion  corrosion,  in which  a  high
ground-water level  is  able  to  gradually  remove  the  protective film  on  the
surface of  the tank and  cause  corrosion  to  occur.   The following  discussion
provides an overview of  how  these  factors  affect  the likelihood for  corrosion
of  tanks  buried  in native  soil  materials  and describes how the environmental
data  are  interpreted  by  a corrosion  expert.   In  this manner,  the  relative
influence  on  tank system  corrosion  from  each  of  the  factors,   and  their
combinations, may  be determined.   It  is important for  an  assessor  to  examine
not only  present  environmental  conditions surrounding  a tank system  but  also
how these  conditions  may  change  over time.    For  example,  the  soil  moisture
level   may  fluctuate  seasonally.   Only  an   experienced  corrosion  expert  is
qualified to assess  the  surrounding  environment  and the  corrosion-prevention
needs  of a tank system.

    It  should  be  noted  here  that the  use  of dry,  crushed  rock  or  dry  pea
gravel as backfill material  (see  Section 6.2  of  this  document)  significantly
reduces  the  potential  for  corrosion,  if  there  is  little or  no ground  water
present.

    A)  Soil  Moisture  Content

    The presence  of moisture or  water  in soil   reduces its  resistivity,  thereby
    increasing  the probability and  rate of corrosion in any portion  of a tank
    system  in  contact  with  the  soil.   Trapped water near a  tank  system  can
    become  anaerobic  and cause  what  is  known  as  bacterial  corrosion.    A
    corrosion  expert  can identify  an  instance of bacterial  corrosion  by  its
    musty  smell,   the  presence  of  hydrogen   sulfide,  and  other  identifying
    characteristics (see soil  sulfides, below).

    Water  can  become  trapped  near  a  tank  system  from  man-made  or  natural
    causes.   Improper installation  practices,  for  example,  can enable water to
    accumulate  alongside  a tank  because  of  voids   in  the backfill.   A  more
    complicated  instance of  soil   moisture  level  affecting  corrosion  occurs
    when  highly  compacted  road  bases  near   a tank  system  have  impermeable,
    compacted  soil  underneath  the  roads.  This  soil condition  can  alter  the

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                                        OSHER Policy Directive No. 9483.00-1

                                    5-31

ground-water flow  conditions  beneath  the tank system because water will no
longer  flow  through  the  surrounding  soil.   Chemical  salts  may  then
accumulate near  the  tank  system,  changing the chemistry and pH of the soil
and potentially enhancing corrosion (see soil pH, below)..

The introduction of  irrigation  or natural  phenomena,  such  as  earthquakes
and  seasonal   soil   moisture  changes,  can  also  change the  flow  and/or
directional characteristics of  the  ground water underlying  a  tank system.
A  corrosion  expert  must  use past  experience with  other tank  systems to
recognize and assess  qualitatively  and quantitatively the effects  of soil
moisture levels on present and future corrosion rates.

B)   Soil Resistivity

Soil   resistivity—the   ability   of   soil   to   resist   the    flow   of
electricity—is an  Important  factor  in  assessing  corrosion  potential  and
in  designing  adequate cathodic protection.   A  corrosion  expert primarily
uses resistivity and  the  strength of  the external  power  source  as a gauge
for predicting  the  galvanic  and  stray  electric current corrosion rates.
Galvanic corrosion may occur  when two dissimilar metal  objects  are placed
in  direct  or  electrical  contact, when  unhomogeneous  soil   conditions  are
present, when old  metal  is  connected  to newer  metal,  or when  the metals
are  exposed  to  uneven   aeration  conditions.   Stray  current  corrosion
results from direct electrical currents flowing  through  the  ground from an
external power  source (see  stray electric  current,  below).  The  flow of
current  during  corrosion  takes   place  through  the   soil;   thus,   high
resistivity soil  Impedes  electron movement  and slows  corrosion.  Without
corrosion  protection, the  lower  the  soil  resistivity, the  greater  the
corrosion  rate.   There is  no upper  limit  on resistivity  1n  which a tank
system  will not  corrode,  however.  That  Is,  a  high  soil resistivity will
decrease the corrosion potential  of a tank system but will  not necessarily
eliminate the potential for corrosion.  Chemicals which  occur  naturally in
the soil and  leaked  wastes  may lead  to  corrosion  even  in high resistivity
soil.    The Intrusion of water may  also decrease  the  resistivity  to a  value
where corrosion  would more  likely occur.  Soil  resistivity  is  a guide  but

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                                    5-32
not an absolute  test  of  a tank system's  ability to resist  corrosion.   Sand
and gravel  backfill  generally  have much  higher  resistivity  than  native
soil backfill  and can thus reduce corrosion  potential.

To  assess  corrosion  potential,  a  corrosion  expert  must  measure  the
resistivity of  the  soil,  for  example,   using  the  American  Society  for
Testing and Materials  (ASTM)  Method G57-78  (the Wenner Nethod),  the Barnes
Layer  Method,   the   Collins   Method,   or    other   methods,   such   as
electromagnetic   resistivity  measurements.  The type  of test required  is
dependent upon the depth  at  which  the  resistivity Is  required  (the Wenner
Method providing  an  average resistivity over a range  of depths  and  the
Barnes Layer  and Collins  Methods providing  resistivity  values at  specific
depths)  and  the  ease  of  drilling  Into  the  soil  (the  electromagnetic
measurements are generally used  when pavement  is Installed  on  the  desi'red
test site).   Soil  samples  should be obtained  as near  to tank system metal
as possible,  preferably  soil  in  contact  with  a tank  bottom or  soil  along
the tank  sides  near the  tank, bottom.  A corrosion expert  should  also try
to  ascertain   whether  the  soil  environment  around  a  tank  system  is
unhomogeneous  with respect to resistivity.   If so,  additional  soil  samples
may be needed.

Resistivity measurements reflect moisture and  chemical  constituent levels
in  soil.   The corrosion  expert  must evaluate  how soil moisture,  pH,  and
sulfide/chloride data will affect resistivity  measurements  in  a  given soil
environment over time.   For  example, the corrosion expert  has  to  estimate
the magnitude of  the effect  on  resistivity  from  seasonal  ground-water
level   changes,   road  salt  application,  road  Installations  that  affect
ground water,  etc.  These  estimates will  be based on  past experience with
other,  similar   tank  systems  and  analysis   of  local,  historical,  and
seasonal  climatic changes.  Resistivity values  range from  below  300 ohm-cm
(highly corrosive) to over 12,000 ohm-cm  (generally less corrosive).

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                                        OSWER Policy Directive No.  9483.00-1

                                    5-33

C)   Soil Sulfides Level

Sulfide  levels  can indicate  the  potential  for  bacterial  corrosion.   The
bacteria  converts soluble  sulfates  in  soil   to sulfides under  anaerobic
conditions.   These  sulfides can  form  acids  that  may  attack tank  system
metal,  causing  corrosion.   Soils  with  sulfide (or  chloride)  levels  of
approximately  300 mg/1  are  considered  highly  corrosive.   Chloride  often
accumulates  in  soil from  road  salting  in winter.  Leaked wastes  which have
accumulated  may  also   change  the  soil  sulfide  level  and  enhance  the
corrosion  of the tank  system.   Soil  sulfide  or chloride levels  and soil
pH, in combination, is  the second most   important factor  for  evaluating the
corrosion potential of a given environment,  following soil  resistivity.

D)   Soil pH

Soil pH,  a  measure  of  the hydrogen ion  content of soil,"is an indicator of
soil  chemical  characteristics.    A  corrosion  expert  must  use   the  pH
information  in  conjunction  with  other  data  on  soil  conditions,   such  as
sulfide, chloride, and  moisture  levels,  to assess  the  chemical  corrosion
potential  of a  particular  soil  environment.   Good engineering  practice
generally would call  for soil samples be  taken  as  near to the bottom of a
tank  as  possible,  and  as  near   the  middle  and the  top of the   tank  as
possible to  determine if  a variation  in  soil  conditions  could  contribute
to galvanic corrosion.

Low  soil  pH  indirectly  indicates   elevated  soil   chloride  content,   a
frequent cause of chemical corrosion.  Additionally,  when  soil pH  does not
fall  Into  the   neutral  range  of approximately 6.2-8.7, soils  may  have
unusual  chemical  characteristics  that   can  cause corrosion.   The  presence
of oxidizing  agents in  soil, such as nitrates,  will  Induce  corrosion.  In
the presence  of  a non-neutral soil  pH,  further  chemical  analyses may  be
necessary   to  assess   the   corrosion   potential   of   the   unusual   soil
environment.   Low  soil  pH  in   sandy   conditions,   however,  may  simply
indicate  the  presence  of  rainwater during  the time of  the  pH  test.   High
soil  pH,   in  general,   indicates   a   less  corrosive  environment.    An

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                                    5-34
assessment by a corrosion  expert  is  generally  required  to determine  if  the
pH  of  the surrounding  soil  may  have  been  altered by  an accumulation  of
leaked waste.

E)   Structure-To-Soil  Potential

Structure-to-soil  potential   is a measurement of  the  potential  difference
(voltage) between  a  tank and  the  surrounding soil.   The magnitude  of  the
voltage  is an  indirect  measure  of  how fast  corrosion  1s occurring.   The
testing  and  the interpretation of  results  should be left to  the corrosion
expert.

It is advisable to install  test  stations for  determining  structure-to-soil
potentials at  the  time  the  tank  is first Installed, since  retrofitting an
existing tank  with test  stations Is much more  difficult  and  costly.   The
use  of  test  stations will  facilitate  the  tak'ing of measurements  and  will
provide  a  common  point of  reference  which  should  produce  consistency  in
the test program.

F)   Influence of  Nearby Underground Metal  Structures

When  underground  dissimilar metal  structures are  in  close  proximity  and
are  connected  by  piping,  conduit,   wiring,  or other continuous  conductive
pathways,  the  media  (e.g.,  water  and/or   soil  salts)   between  the  metal
structures provide  the  necessary  electrical  pathway   so   that  galvanic
corrosion can occur and destroy the tank.

In  other  words,   the  underground  media complete  an  electrical  circuit
through  the  nearby dissimilar  metals,  and  the  resulting  current  flow  can
cause  corrosion  in  the tank.    A  corrosion  expert can  assess  the  extent
that nearby  metal  structures  in  contact with soil or  water  Influence  the
corrosion potential  of  a tank  system.   Both  the  type  of  metals  involved
and  the  distance  between  the  structures  and a  tank  system  are  important
factors  in this  determination.  A  separation of 12 Inches  between  nearby
buried  metal   structures  Is generally  the  minimum  acceptable  distance.

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                                        OSWtR Policy Directive Ho. 9483.00-1

                                    5-35

However, a corrosion expert should make a recommendation  for  each specific
tank  installation.   The  supervisor  of a  tank system  installation  should
ensure  that  new  metal  tanks  installed   alongside  old  metal   tanks  are
adequately  separated.   (See  Section  6.0 of  this  document.)   If  separation
Is  not possible,  nearby metal  structures  may  have  to  be  electrically
Isolated from the tank system.

Nearby  metal  structures  can also  be  inadvertently  connected  to  a  tank
system, for  example,  through electrical  and/or water  system connections.
This  situation  should be  prevented  by using  electrical  isolation devices
(e.g., insulated bushings).

If a  nearby  underground  metal structure has a  cathodic-protection system,
that  system  must  be  properly connected to  or electrically  Isolated  from
the tank  system.   Otherwise, stray  currents from  the  cathodic-protection
system can cause accelerated corrosion of  portions of the tank system.

G)   Existence of Stray Electric Current
                                         •
Stray electric  currents  from subway,  gas  distribution, and any  other  type
of  direct  current  (DC)  power  distribution  system   can   increase   the
corrosion potential  of a  tank  system.  Direct  currents  flowing  from the
power sources through  the  ground  to  the tank  system  and  then back  to the
sources cause stray current corrosion.

The rate  at which  stray  current  corrosion  occurs  is  directly  related  to
the Intensity of the  currents.  These  currents, if large enough, can  even
cause coatings  to  separate  from tanks.  A corrosion  expert  should be  able
to assess the relative corrosion potential  of a tank  system by determining
its   proximity  to   sources   of  stray  current,   evaluating   the  complex
electrical conductance of  the ground  surrounding the  tank  system,  and  by
measuring the magnitude of the stray  currents.

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                                    5-36

H)   Existing Corrosion Protection Measures

A corrosion  expert  will  be  able  to assess  the  effectiveness of  existing
corrosion protection measures  by  examining past  records,  If available,  for
a  tank,  system  and  determining  the  reliability  of   these   protective
measures.  The  information obtained  in  this assessment will  be  used by  the
corrosion expert  to  assess  the condition  of the  tank  system, as  required
under Sec. 264.19Kb).

Corrosion  protection  practices  using   corrosion-resistant  materials   of
construction, coatings, electrical  isolation,  and cathodic  protection  are
described  in  the  National   Association   of  Corrosion  Engineers  (NACE)
Standards  RP-02-85   and   RP-01-69,  "Recommended   Practice—Contro1   cf
External  Corrosion   on  Metallic  Buried,   Partially Buried,  or  Submerged
Liquid  Storage  Systems"   (1985)  and  "Recommended  Practice—Control   of
External  Corrosion  on  Underground  or  Submerged Metallic  Piping  Systems"
(1983),   respectively,   and   the   American   Petroleum   Institute   (API)
Publication  1632,  "Cathodic-Protection  of Underground  Storage Tanks  and
Piping Systems"  (1983).  Coatings  electrically separate tank systems  from
the  surrounding  ground   media.    Wraps   perform 'the  same  function   as
coatings,  but  wraps  are   not  bonded to  tank systems and   thus  must  be
properly  installed  to  be  effective.   Electrical isolation  devices (e.g.,
insulated bushings,  joints, and couplings)  separate  a  tank  system  from  all
nearby  underground  metal  structures.   Cathodic-protection  methods prevent
current  from  leaving  a   tank  system  through  the   use   of  either  a
sacrificial-anode system  or an  impressed-current system.   A sacrificial-
anode system, because of the potential difference between  the tank and  the
anode,  will  discharge  electrical current,  which Is collected by  the  tank
and  returned to  the  sacrificial  anode   through  a  metallic  connection.
Thus,  the  anode will  corrode,  not the  tank, system.   An  Impressed-current
system employs a rectifier to  produce a direct current that  flows from an
anode through the ground to a tank system.

The  corrosion expert must  describe which corrosion protection  methods  are
employed  for a  particular  tank  system and  judge   how effectively  these

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                                        OSHER Policy Directive  No.  9483.00-J

                                    5-37

methods  have  prevented corrosion  in  the  past.   If corrosion  protection
system  records  do not  exist,  the corrosion  expert must rely on  signs  of
leakage,  the  present  soil-to-structure potential  values,  any  available
ground-water, well water, or  soil  testing  results which may be  available,
and  the estimated  age and  construction  materials  of  the  tank  system.
Questions   that   should   be   answered  to   judge  corrosion   protection
effectiveness include:

o    Has the  tank system  leaked  in  the past?   Has the  structure-to-soil
     potential remained consistently  at or  below 850 millivolts negative?

o    How complete is  the  coverage  of a coating  or wrap?   Has  this coverage
     decreased over  time  from drying,  cracking,  dissolution?   Will- the
     coating or wrap be damaged by spills of  the tank's  hazardous contents?

o    Is  the  electrical isolation  from  nearby underground  metal  structures
     adequate (i.e.,  Is the  tank  system electrically isolated from  anchor
     straps,  compressors,  pumping  stations,  other metal  tanks,  and  at the
     junctions of coated  and  uncoated   piping,  etc.)?   Are the  electrical
     isolation devices damaged In  any way?  Are the devices  appropriate
     for the needs of the  sacrificial-anode system, if applicable?

o    How long has a  sacrificial-anode  system been  in place,  and  have  the
     anodes  decreased  significantly  in size?   Is the   protective  current
     requirement variable met, requiring that an  impressed-current  system
     (not   a    sacrificial-anode    system)    be    installed?     Is    the
     sacrificial-anode system damaged in any  way?

o    How  long has  an  impressed-current  system  been  in  place  and  have
     protective  current  requirements  changed over  time?  Are  there  any
     trends In the required protective  current  (e.g., consistent increases
     or  cycles   in  protective current requirements)?   Is  the  Impressed-
     current  system damaged  in  any way?   Is  the  impressed-current  system
     properly maintained?

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                                        5-38

    Based on  the  answers  to  the above questions,  the  corrosion expert  should
    be  able  to   assess  the  extent  to  which  existing  corrosion  protection
    measures  reduce  a  tank,  system's  corrosion  rate.    (The   NACE  and  API
    references listed  above  provide  additional  information  on  assessing tank
    system corrosion potential.)

                     5.4.2  Corrosion  Protection Assessment.

    Citation

    Given  information  on  the  environment   surrounding  a   tank   system,  as
obtained  under  Sec. 264.192(a),  a  corrosion expert  can assess the  corrosion
protection  needs  of  the  system.   As stated  in  Sec.  264.192(a)(3)(i1),  the
corrosion expert must assess:

    The type  and  degree of  external corrosion protection  that  are needed
    to ensure the integrity  of the tank system during the use of the tank
    system or component,  consisting of one  or more of the following:
    (A)  Corrosion-resistant  materials  of construction  such  as  special
         alloys,  fiberglass  reinforced plastic,  etc.;
    
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                                        OSWER Policy Directive No.  9483.00-1

                                    5-39

A)   Corrosion-Resistant Materials of Construction

If a  tank  system  is  new, selection  of  a tank  system  constructed  with  or
covered    with    corrosion-resistant    materials   may   be    advisable.
Manufacturers  can provide  more  Information  on  the   corrosion-resistant
characteristics of tank  system  materials  and their compatibility with tank
contents.  A tank system with certain types of  protection, e.g.,  Installed
within a  wrap or a  concrete vault, may  be  considered  corrosion-resistant
if it does not contact soil  or ground water and  is  Isolated  from potential
sources  of  current   (use  electrical  Isolation  devices).   A  metal  tank
system   constructed   of  or   with   a    coating   on   its   exterior   of
corrosion-resistant   materials,  electrically   isolated   from  the  ground
media, and  provided  with  a  sacrificial   anode  or  impressed-current system
would be  considered  optimally protected.

The  most  commonly   used  non-metallic,  corrosion-resistant  material   of
construction  is  fiberglass-reinforced  plastic  (FRP).   Although FRP  tanks
are usually  referred to as  a  single  class,  they can be  fabricated  from a
wide variety of resins.   The selection of resin  depends upon compatibility
with  the  material  to be  contained and  the  conditions  of  storage.   FRP
tanks  can  be  installed  in  a  wide  variety  of  soil   conditions  without
concern  for  corrosion.    The  primary disadvantage of  FRP  is  that  it  is
somewhat   more  susceptible  to installation  errors than  is  steel  (e.g.,
puncture).

B)   Corrosion-Resistant Coating

Coatings   are thin applications  of  synthetic  or  non-synthetic  materials,
either wrapped,   sprayed, or  brushed  on  a  tank  or  piping  exterior  to
prevent corrosion.   Coatings  Isolate the underlying metal structures  from
contact with  the  surrounding  soil  and/or  water environment.   Linings  are
materials bonded  to  the  Inner shell  of  a  tank to protect against internal
chemical   corrosion.   Table  5-5  lists  types  of  coatings/linings  and  the
chemicals  with  which  these  materials   are  generally  incompatible.   Any
damage to a  coating,  however,  can produce  accelerated  local corrosion  on

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                                             jn '_l\ IW'I^Jf  UT j i C. W I 1 f C
                                        5-40


                                   TABLE 5-5

                          COATING/LINING VS.  CHEMICALS
   Coating/Lining Material
Generally Incompatible Hith
   Alkyds



   Chlorinated rubbers

   Coal tar epoxy

   Epoxy (amine cured, polyamide
     cured, or esters)

   Polyesters


   Silicones


   Vinyls (polyvinyl  chlorlde-PVC)
Strong  mineral  acids,  strong  alkalies,
alcohol, ketones,  esters, aromatic hydro-
carbons

Organic solvents

Strong organic solvents

Oxidizing acids (nitric acid),
ketones

Oxidizing acids, strong alkalies, miner-
al acids, ketones, aromatic hydrocarbons

Strong  mineral  acids,  strong  alkalies,
alcohols, ketones, aromatic hydrocarbons

Ketones, esters, aromatic hydrocarbons
Source:  New York  State  Department of Environmental  Conservation,  "Technology
         for  the   Storage  of  Hazardous   Liquids—A  State-of-the-Art  Review"
         (January 1983),  p.  36.

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                                        OSWER Policy Directive No.  9483.00-1
                                    5-41
the  exterior  of a metal  tank  system,  since the  localized  areas  of damage
create  points  on the  tank system  at which  stray  currents  or  corrosive
chemicals  in   the  soil,  accumulated  leaked wastes,  or  water  can  cause
concentrated corrosive  attack  of  the  tank  system  or  component.  In  its
standard  ratified  on March 29,  1985,  ("Recommended  Practices  for Control
of External Corrosion on  Metallic Buried,  Partially Buried,  or  Submerged
Liquid   Storage   Systems,"   NACE  Technical  Practices   Committee),   NACE
recommends that  the  following  precautions  be taken  to  avoid problems  due
to damaged  or  poor  coatings  caused by  improper application  or improper
tank Installations:

o    Handling        Damage  to   coating   shall   be   minimized   by  careful
                    handling and by using proper cradles and slings.

o    Inspection     Qualified   personnel   shall  monitor   and  inspect  each
                    phase   of   the  coating  operation,   including  surface
                    preparation.  Quality  control  and  Inspection programs
                    should be developed.

                    A  coating   shall  be   tested  immediately   prior   to
                    Installation  of  the   system   by   using   appropriate
                    holiday detectors and visual  inspection.  All detected
                    coating damage shall  be repaired.
     Installation
The excavation  shall  be  free of any material  that may
damage the coating.
                    To prevent  damage  to  the  tank  or  coating,  equipment
                    for installing  the  tank shall  be of adequate  size  to
                    raise   and   lower    the   tank   without   dragging   or
                    dropping.   Similar  care shall  be given to the piping.

                    If the tank  is  installed  on a  concrete  slab,  it  shall
                    be separated from the  slab  by at least  6  in.  (15  cm)
                    of sand or other approved  homogeneous  backfill.

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                                              rout>  u i receive  MO.

                                    5-42

                    Anchor  straps  and  ground anchors.  If used,  shall  be
                    installed  in such a manner  that  they  do  not  damage the
                    coating  and  are  electrically isolated from  the  tank.
                    If  necessary,  a  separate  cathodlc  protection  system
                    may be  applied  to the  straps.

                    The backfill  shall   consist of   clean  sand  or  other
                    selected  fill that is  free  of organic material,  rocks,
                    debris,  and  other sharp objects.

                    The backfill shall  be  deposited  carefully around  the
                    buried  parts of  the   tank  to a  thickness  of at  least
                    1  ft (30  cm).  Avoid  damage to the  coating,  especially
                    where  tamping  is required.  See   NFPA  30  and state  or
                    local  codes  for depth  of cover  required.

A factory-installed coating  is   generally  preferable  to  a field-installed
coating.   Coating  and  1ining'manufacturers can provide information  on the
corrosion-resistant character!stios of their  manufactured  materials.   NACE
publications  RP-02-85  and   RP-01-69  provide  additional  information  on
desirable coating characteristics and on   coating handling, inspection, and
installation techniques, as  well  as references on coatings.

C)   Cathodic Protection

Cathodic  protection  is the  most effective  means  of corrosion  protection
available and is often used  in conjunction  with other corrosion  protection
measures.   As  discussed   in  Section 5.4.1  of  this  document,  cathodic
protection  can  consist of  installing a   sacrificial-anode  system  or  an
impressed-current  system.   In  general,   impressed-current systems  require
more maintenance  than  sacrificial-anode   systems and  can  cause  additional
problems by generating stray currents.

Some  sites  may  require that  cathodlc-protection  systems  be designed  to
meet site-specific conditions,  particularly at  locations  with very  low  or

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                                        OSHER Policy Directive No. 9483.00-1

                                    5-43

very  high  soil  resistivities.    Cathodic-protection  devices,  if  needed,
must  always  be  placed inside  the  confines of  any lined excavation  (the
lining acts as an insulator) or within a concrete vault.

Based on  the  information  obtained  under  Sec.  264.192(a),   the  corrosion
expert  should  be able  to  evaluate quantitatively  the  cathodic-protection
needs of a tank  system to  ensure structural Integrity during  the system's
use.  Additionally, under  the  requirements  of  Sec.  254.192(f) and (g), the
owner/operator is  required to  provide  the   type  and  degree  of  corrosion
protection recommended  by  the  independent  corrosion expert,  or required by
the   EPA   Regional    Administrator,   to    have   the    installation   of
field-fabricated  corrosion-protection systems  supervised  by  an independent
corrosion expert, and  to obtain and keep on file  at  the facility  written
certifications for the design,  installation, and repairs  to  the system.

     1)    SACRIFICIAL ANODE

     This cathodic-protection  method employs a sacrificial  anode,  such as
     magnesium or zinc,  in eledtrical  contact  with the metal  structure to
     be   protected.   These  anodes may  be  buried in  the  ground  nearby or
     attached  to  the   surface of a metal tank system.    Corrosion  of  the
     sacrificial-anode  material  produces  the  necessary  low-level  electric
     current.  A  typical sacrificial-anode,   cathodic-protection  system for
     underground   tanks  and  piping  is  illustrated   in  Figure   5-9.   A
     sacrificial-anode  system   can   either  be   purchased   from  a   tank
     manufacturer with  the anodes  already  attached to a tank  (see  Figure
     5-10)  or connected to  a tank following  initial  emplacement.

     2)    IMPRESSED CURRENT

     This cathodic-protection method  employs direct current  (DC)  provided
     by   an  external  current source.   This  current  is  passed through  the
     system by the use of  anodes,  such  as  carbon, non-corrodible  alloys,
     or   platinum.   These   anodes  are  buried  in the ground (in the case of
     underground    structures)   or   otherwise    suspended   in   the    soil

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                                    5-44
                              Figure 5-9
                 Sacrificial Anode Cathodic Protection
                                                   Test Box
        Tank
                                                               Coating
 Insulated
 Bushing
                                                      Dielectric Insulation
                                                       To Grade
    Magnesium Anode In Bag
Source:   Suggested  Ways  to  Meet Corrosion  Protection  Codes  for  Underground
         Tanks and Piping, The Hinchman Company, Detroit, MI,  1981.
   FIGURES ARE FOR ILLUSTRATIVE PURPOSES ONLY. THEY ARE NOT INTENDED FOR USE AS
   CONSTRUCTION DRAWINGS.

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                                       5-45
                                 Figure 5-10

                    Factory Installed Sacrificial Anode
                                                                                        I
                                                                                       c
                                                                                       c

                                                                                       

                                                                                        o
                     Pr«-«ngin««r«d

                     Sacrificial Anode
                     Attached  by

                     Manufacture
                                                                                        c
                                                                                        c.

                                                                                        ac
                                                                                        v.
                                                                                        C
FIGURES ARE FOR ILLUSTRATIVE PURPOSES ONLY. THEY ARE NOT INTENDED FOR USE AS

CONSTRUCTION DRAWINGS.

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                                               ^ . i Cjr  Jii~cVt.i«£  rto.

                                    5-46

electrolyte   and   connected   to   an    external    power    supply.     An
Impressed-current  system  can  be  regulated  to meet  any  level  of  soil
aggressiveness  but,   being   a  highly   dynamic  design,   requires   regular
supervision  and  periodic  maintenance.   Generally,   an   Impressed-current
system should be inspected  at least two  times a year,  including  a  check of
soil  resistivity  each  time.   A  typical   impressed-current   system  for
underground tanks and  piping is illustrated in Figure 5-11.

An  Impressed-current  system can  be  installed at any time during  the  life
of  a  tank  system,  and  it  can  be   adjusted  to meet  changing  protective
current needs.   When  an  impressed-current  system  is operating, all  metal
structures  within  its  electrical  field  must  be  bonded to  the  electric
current;   any  unbonded  metal  may   corrode  under   the  Influence  of. the
impressed current.   Nearby  gas,  water,  or utility lines must  be protected
from  stray  currents   which  may be generated  by  the   impressed-current
system.  These potential problems may be  eliminated  by an investigation of
the  impact  of  the system  on nearby structures before  its operation.   A
corrosion  expert  should   conduct   this   investigation   and  design   and
implement  any .required protective  measures.   When an  impressed-current
system is attached  to  a used  tank system, it  is especially  important that
the cathodic-protection mechanism's  performance  be  regularly inspected and
monitored; otherwise,   corrosion on  the protected  tank  system or  adjacent
metallic   structures may be accelerated  inadvertently.   Damage  to wiring,
electrical  connections, or operator error  may cause  the  generation  of
stray currents.

D)   Electrical  Isolation  Devices

Electrical  Isolation   devices  remove   nearby  metal  structures  from  the
cathodic-protection circuit.   Such  devices   isolate a  tank  electrically
from any  metallic  anchoring,  piping, and pump(s).   Electrical  isolation is
necessary with a sacrificial-anode  system because  the amount  of  metal  to
be  protected  must  be  limited  to maximize  the corrosion protection.   As
stated  earlier,   however,  electrical   bonding,  rather  than   electrical
isolation, should be used  for  an impressed-current  system.

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                                              5-47
                                         Figure 5-11

                         Impressed Current Cathodic Protection
            R«turn Circuit
                                                               RECTIFIER
                                                               20-60 Volt D C.
                                                                     D C  Currant
                                                                     lo Anod«-
                                                               Anod«  Bed
                                                              NOTE: Piping not shown (Of clarify
                                                                   of drawing.
Source:  Suggested  Ways  to  Meet  Corrosion  Protection  Codes  for  Underground
         Tanks and Piping.  The Hlnchman Company, Detroit, MI,  1981.
            FIGURES ARE  FOR ILLUSTRATIVE PURPOSES ONLY. THEY ARE NOT INTENDED FOR  USE  AS
            CONSTRUCTION DRAWINGS.

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                                        5-48

    Isolation  devices  used  to  maintain  effective  grounding  and  the  desired
    isolation  include  electrically  resistive  envelopes,   flange  assemblies,
    bushings,  prefabricated  insulating joints,  unions, and  couplings.   NACE
    Standard   RP-01-77,   "Recommended  Practice—Mitigation   of  Alternating
    Current and Lightning  Effects on  Metallic  Structures and  Corrosion-Control
    Systems,"  provides additional  information  on  this  subject.   A  corrosion
    expert who  is  familiar  with  the  use  of  electrical  Isolation devices  will
    be able to decide where and  how  a  tank, system's electrical  isolation  needs
    to be upgraded.

                     5.5   PROTECTION FROM  VEHICULAR  TRAFFIC

     Citation

     Because  portions  of  an underground  tank system  may  be  subject to  the
damaging effects of  vehicular loads,  Sec.  264.192(a)(4) requires for  new  tank
systems  that  the  owner  or  operator  assess  the  design  and/or   operational
measures  that  protect a  tank  system from  these   loads.   As  stated   in  this
section,  the  owner  or  operator  must  include  in   the  written assessment  the'
following informatics:

    For  underground  tank  system  components   that  are   likely   to   be
    adversely affected by  vehicular traffic,  a determination  of design or
    operational  measures   that   will   protect   the   tank  system   against
    potential damage;....

     Guidance

     In order  to  avoid premature structural  failure,  a tank system  should  be
designed and installed so that It can  support expected  vehicular loads.   Cover
In  traffic  areas  should  be  a  minimum  of 36  inches—30  Inches of  compacted
backfill and 6 inches of  asphaltic concrete are suggested.   (An alternative  is
not  less  than  18   Inches  of compacted  backfill,   plus at  least  6 inches  of
reinforced concrete  or  3  inches  of asphaltic concrete.)   A   larger   tank  may
require even  greater coverage.    Asphaltic or  reinforced concrete  paving  over
tanks in traffic areas should extend at least one  foot  beyond the  perimeter  of

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                                            OSHER Policy Directive No. 9483.00-1

                                        5-49

a  tank.  In all  directions.   An underlying  synthetic,  impermeable  layer  below
the  pavement  is recommended.  If the  depth  of  cover is greater  than a tank's
diameter,  the   tank  manufacturer  should  be  consulted   to  determine   if  tank
structural reinforcement  is  needed.   A  minimum horizontal  backfill  clearance
in all  directions  of 12 inches Is  recommended  for  steel  tanks,  and  18 inches
is recommended  for  FRP  tanks.   ("Installation of Underground Petroleum Storage
Systems,"  API   Publication   1615  (November  1979),   pp.   3-6.    See  also  the
Petroleum  Equipment  Institute (PEI)  Publication  PEI/RP100-86,  "Recommended
Practices for Installation of Underground Liquid Storage  Systems.")

     Operational measures  that  avoid  excessive vehicular  loads  on  a  tank
system  Include  instituting  a  weight  limit  on vehicles  traveling  above a tank
system  and/or  constructing   guardrails   or  barricades  around   tank  system
components susceptible  to damage  from such  loads.   The  professional engineer
who reviews and  certifies  the written assessment for  the  tank  system design
must be  able  to judge the effectiveness of  the  methods  used to prevent damage
from vehicular traffic.
                           \
                      5.6  FOUNDATION  LOADS  AND  ANCHORING

     Citation

     A  tank  system's foundation  must  be able  to support the  load of a  full
tank,  and tank anchoring must  prevent flotation   and  dislodgment.   Section
264.192(a)(5)(i) and  (ii) state  that  the  owner or operator  of  a   new  tank
system must ascertain that:

    (1)   Tank foundations  will  maintain the  load of  a full  tank;
   (11)   Tank   systems  will   be    anchored   to  prevent   flotation   or
         dislodgment where the tank system  is placed In  a saturated zone,
         or  is   located  within  a  seismic   fault  zone   subject  to  the
         standards  of Sec.  264.18(a);	

     Guidance

     The  owner  or  operator  and  the  independent,   qualified,   registered
professional   engineer  must   be   familiar  with  the  characteristics  of  the

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                                        5-50

surrounding geological  environment  and the  history  of  similar  structures  in
the  vicinity.   This  requirement  applies   to   all   types   of  tank   systems:
aboveground,  onground,  inground,  and  underground.    After  uniform  settlement
occurs,  piping  must  not  be strained.   Additional   information  on  assessing
foundation  integrity  is  contained  in  API  Standards  620  and 650,  "Recommended
Rules  for  Design  and  Construction  of  Large,  Welded,  Low-Pressure  Storage
Tanks" (1982), Appendix  C,  and  "Welded Steel Tanks  for  Oil Storage"  (Revised
1984),  Appendix  B.   For  assessing  structural  integrity  in  concrete  tanks,
consult   the   American   Concrete   Institute's    (ACI)   Publication   350R-83,
"Concrete Sanitary  Engineering Structures,  Section  2.4—Types of  Foundations."

     Underground   or  inground  tanks   may   be   subject   to flotation  and/or
dlslodgment when  placed  In  zones  that may  be  saturated  at  some  time  from
seasonal   precipitation   changes,   a  floodplain - location,  stormwater  runoff,
etc.  The anchoring systems for these  tanks  must be  assessed  for  adequacy and
structural  integrity.   Manufacturers'  recommendations on anchoring  techniques
should be  followed.   Tank  vents  and other openings  that are  not  liquid-tight
must be located above maximum water level.

     Normal paving and  backfill  usually provide  adequate restraint  for tanks.
Because  of their  additional  weight,  steel tanks   are  less  susceptible  to
flotation  than  FRP tanks,  and  smaller tanks are  generally less  buoyant  than
larger  tanks.   If  there  is  any  question  on   whether  or  not  weighting  or
anchoring   is   necessary,  a  professional  engineer  should  estimate  expected
ground-water  levels  and calculate  buoyant  forces.   (Buoyancy tables   for  FRP
tanks  are  available  in  the  Owens-Corning   "Fiberglass  Underground  Tank
Installation  Techniques  Manual" (September  1984).   Consult  tank  manufacturers
for buoyancy  information on  steel  tanks.   See ACI,  350R-83, "Concrete Sanitary
Engineering Structures"  (September  1984)  for Information on Issues  concerning
weighting or anchoring in concrete structures.)

     If  additional  anchoring is  necessary,  buoyancy may be offset by the use
of  hold-down  pads,  prefabricated  deadmen,  or  mid-anchoring.   These  devices
(see Figure 4-1)  are  described as  follows:

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                                           5-51
   Pavement


             Hold-down pad
a in. reinforced concrete    Mln. 37* backfll
              Nonconductive

           protection fo

              hell and coating
                                                    Pavemerrt
                                                 v.«7r:;;•"*••.'•'•'.•.•••'•• •'.••"•'••.;•• I? '.*•'• !•"• ••.">••'•'
                                                 :f•*•;•.•;•:•.•••:.'.'••.•.':•'•'•'.•*•'.•.'.'•;•.'•."••.'•'•'.: .'•':"• •"•;•'• •'•••'::
                                                 •vi'^'^xi'lif Straps and connectors
                                                              Deadmen anchors
                                                                     Figure  5-12

                                                               Anchoring Techniques
              Mid-anchoring
         FIGURES ARE FOR ILLUSTRATIVE PURPOSES ONLY. THEr ARE NOT INTENDED FOR USE AS


         CONSTRUCTION DRAWINGS.
                                               OSWER  Policy  Directive   9483.00-1

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                                            UOfTirt f U : i <- J  UiiCbklVti  I1U.  3tOJ.VU-l
                                        5-52
     o    Hold-down  pads  are  reinforced  concrete  pads   that   provide   firm
          foundations for tanks.   The  pads  also offset buoyancy of  the  tanks.
          These pads extend  18  Inches  beyond the sides of  tanks  and one  foot
          beyond  the  ends.   Pad  thickness  Is  determined by  maximum  water
          level, tank size and weight,  burial depth, and paving.

     o    Deadmen  anchors  are beams  of  reinforced  concrete  with   straps  and
          cables attached.  Anchoring  straps  and cables must not damage tanks;
          these devices  may  be  separated from  tanks  with  padding   (e.g.,  by
          using portions of rubber tires.)

     o    Mid-anchoring  consists  of   placing  unreinforced  concrete over  the
          tops  of  tanks.   Backfill  should  be  placed  above  these   tanks  and
          reinforced   concrete   at   grade.     Tanks   must   be   covered   with
          nonconductive   material   to   maintain   electrical   Isolation   for
          cathodically-protected tanks  and  to protect coatings and tank shells
          from damage from the concrete.

     All  anchoring  devices must  be  adequately  protected  from corrosion  and
other  forms  of  deterioration,  and  they  must   not  damage  the  tank  system.
Anchoring straps must be uniformly tight and spaced so that the  tank  load will
be  evenly  distributed.   Anchoring straps  on  a  steel  tank must  be  separated
from the  tank  by  a pad made of  inert material.   The pad should be  wider than
the  hold-down straps  to  prevent  coating  scratches  and to  ensure  electrical
isolation of  the  tank  and its anchoring,   FRP  straps must  be  aligned  cm  the
tank ribs, not between the ribs.

     Any  tank  system in  a location where  compliance with  Sec.  264.18(a) must
be  demonstrated   (locations   in   a  fault  zone  and   therefore   subject  to
earthquakes)   Is   required  under  Sec.   264.192(a)(5)(11)  to   be  anchored
appropriately  to prevent  dislodgment  (see Appendix VI of Sec.  264,  "Political
Jurisdictions  in  Which  Compliance with Sec. 264.18(a) Must Be  Demonstrated").
Anchoring methods  that  may be  used  are  the  same as  those described  in this
section  to  prevent flotation.  Appendix  E of API Standard  650,  "Welded Steel
Tanks  for Oil Storage"  (Revised  1984),  Appendix E,  provides   information  on

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                                                  policy Uireceive No. 948J.00-I

                                        5-53

seismic  design  for storage  tanks  and piping,  including details  on  anchoring
specifications  and calculations.   This   is  a  highly  technical  discussion of
design  parameters  that  is  not  appropriate  for  includsion  in  this  document
except by reference.

                       5.7 PROTECTION AGAINST FROST HEAVE

     Citation

     New tank systems  must be protected  against the potential  damaging effects
of frost heave,  as stated in Sec. 264.192(a)(5Xiii):

          Tank systems will withstand the effects  of frost heave.

     Guidance

     Tank^ systems that are underground or partially underground  may  be subject
to forces  from  frost  heave  and  thaw instability in colder  climates.  Designs
must be  adequate  to  ensure  that tanks  and  all  ancillary•  equipment are  not
damaged from these forces.

     The owner  or operator  must first predict what  the  expected  frost  level
(depth)  will  be in the  areas where tanks  are or  will  be installed.   This
information  is   available  from  the  soil  conservation  service  of   the  state
departments  of  agriculture.    These  services  produce  soil    surveys   with
county-wide Information on frost  potential and depths.

     The   greatest   potential   problems   from   frost    and  thaw  damage  are
anticipated to be in  the piping  systems,  since they are  generally at  shallower
depths and  are  weaker  structures  than the  tanks.   Welding rather  than  screw
threads for piping joints is recommended  in  very cold climates.   Expansion  and
contraction of  piping joints  from  thermal  effects will otherwise cause  slow
leaks to occur.   Devices which can be used to protect against frost  uplift  are
swing joints or  flexible  joints  that are welded or flanged  to  the rest  of the
pipe.

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                                            OSWER  Policy  Directive  No.  9483.00-1

                                        5-54

     Thaw  instability  can  cause problems  with  either piping or with  the  tank
itself.  The instability occurs when  a  tank and/or its ancillary  equipment  is
installed  in  soil  which retains frozen  water  in  its  matrix, e.g.,  in  organic
silts.  If  the  ice  melts,  the soil matrix  will  lose  a  significant amount  of
strength,  causing   the  support  for  the  tank  system  to  fail,  resulting  in
leakage.   A better  understanding  of  soil  conditions  and  the  potential  for
frost  can  allow  precautions  to be  taken which will minimize  the  potential  for
damage due to thaw instability.

     For new tanks,  or,for  used tanks which are  to be reinstalled,  the  use  of
pea  gravel,  sand,  or  some  other  highly permeable material as  backfill  allows
most Infiltrating water to  drain  out  of the  tank  excavation,  thus  minimizing
the  potential  for  frost  problems.   Tanks and ancillary  equipment should  be
located, if possible, below the frost  depth and straight,  welded  piping should
be  installed  in an  area with permafrost because   leak detection  is  impossible
under  such conditions.

     For  tanks  that  are  already  in  the  ground,  if the  tank  systems  have
withstood  the  impact  of  frost  over  a  period  of  several  years   without  leak
damage, that docume-ted experience may  be  one indication  that  the  systems  may
be  adequately   protected  against  frost  heave.    If  proper  design  cannot  be
confirmed  through  leak tests  and  other evaluations,  the  owner  or  operator,
with   the   possible  assistance  of  an   independent,   qualified,   registered
professional  engineer,   should   assess   the   available   frost   protection
alternatives.   Such alternatives  as  the  installation  of resistance  heating
wires  near  a tank  system  or  installation  of  swing joints can either  prevent
frost  from occurring near  the tank system or  enable the  system  to withstand
the forces of frost heave  so that the  system will  not  leak.

     As  with all   construction  and  Installation  operations,   the  owner  or
operator  should  become familiar  with  local  codes to ensure that  the  chosen
protective method conforms  to them.

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                                            OSHER Policy Directive No. 9483.00-1


                                        5-55

                                                                                a
                          5.8  SUMMARY OF MAJOR POINTS


    This subsection summarizes  the  information covered in this section and may

be used  In  assuring  the completeness of a  Part  B  permit application.   It  can

also be  helpful  in  planning,  preparing, and verifying the adequacy of the tank.
system.


    o    Dimensions and Capacity

              Are all  dimensions  Including  wall  thickness  of each  tank.
              and   related   appurtenances   clearly   indicated    and/or
              displayed in the scale drawings?

              Is  the  capacity  of  each  tank  clearly  indicated  (nominal
              and/or maximum capacity)?

              Were any field modifications  made that affect tank capacity?

              Was  the   gauge  table  field-verified   and   modified,  as
              necessary, to reflect  installed conditions accurately?

              Is  the  manufacturer's  specification  sheet  and  gauge  chart
              Included  in  the permit  application  for  all  preconstructed
              tanks?

    o    Feed  Systems,   Safety  Cutoff,  Bypass  Systems,   and  Pressure
         Controls

              Has a description of  the tank feed systems,  safety cutoff,
              bypass systems, and pressure  controls been included  in the
              permit application?

              Does  the   equipment    meet   construction  guidelines   and
              standards designed to  prevent:

                   Explosion or Implosion of tanks,
               -   Fire.
                   Emissions of hazardous vapors, and
                   Spillage of  hazardous material  due to overfilling  of
                   vessels or drainage from product  transfer hoses?

              Does  the  description  of  the  equipment  in   the  permit
              application  adequately  verify  compliance  with  pertinent
              construction standards?

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                               5-56
Diagram of Piping.  Instruction,  and  Process  Flow

     Is  the   tank  system  diagram  clear and  does  it  show  all
     relevant tank  system components?

     Is  satisfactory  documentation   Included   1n   the   permit
     application to describe process flow characteristics?

External  Corrosion  Protection

     Does  the  facility  have  adequate  records  of   tank  system
     materials  of   construction  and  of   corrosion   protection
     systems?

     Have nearby tank systems been affected  by corrosion?

     Is  the   corrosion  expert   able   to assess  adequately  the
     corrosion potential  of the  environment surrounding  the  tank
     system?   What  is  likely to cause (or  has  caused)  corrosion
     of the tank system?

     Can the  corrosion expert determine  the  type  and degree  of
     corrosion protection  needed  to ensure  tank system Integrity
     during its  use?

     Does  the facility  maintain  comprehensive  maintenance  and
     repair  records?   (This  is   particularly  Important  where
     impressed-current systems are operating.)

     Has the  owner or  operator  provided  the  type  and degree  of
     corrosion   protection   recommended   by   an   independent
     corrosion expert, based on  the information provided  in  the
     assessment?

     Has  the  installation  of   any  field-fabricated  corrosion
     protection   system   been   supervised  by   an   independent
     corrosion expert?

Protection From  Vehicular Traffic

     Have  the design and/or operational  measures  that protect  a
     tank  system from the  damaging effects  of vehicular  loads
     been assessed?

Foundation Loads and Anchoring

     Has  It   been   determined   that  the  tank  foundation  will
     maintain the load of a full  tank?

     Are   tank   systems    anchored   to   prevent   flotation   or
     dislodgement if placed  in  a  saturated  zone or seismic fault
     zone?

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                                            OSWER Policy Directive No.  943J.OG-1


                                        5-57
    o    Protection Against Frost Heave
              Have design  precautions  been  taken so that  the  tank system
              withstands the effects of frost heave?
In  addition,  see Appendix  A, "Completeness  Checklist,"  to verify  compliance
with the requirements of this section.

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                                            OSWER Policy Directive  No.  9483.00-1


                                        6-1


                      6.0   INSTALLATION OF NEW TANK SYSTEMS
    Section 264.192(b-g)  requires  an owner  or operator to ensure  that  proper

handling procedures are  used  to prevent damage to a  new  tank  system or a  new

component at the  time  of installation.   Should damage occur during the  course

of an installation, the owner or operator  must remedy it before the  system is

fully installed or  placed  in  use.   The  Sec.  264.192(b-g)  requirements apply to

new tank systems  and  components.   The  terms  "new tank  system"  and  "new  tank

component"   also   include   reinstalled  and   replacement   tank   systems   or

components.  The  professional  engineers  who  certify a  new,   permitted  tank

system's  design  and   those  who  supervise,   new tank  system  and  component

installation are required to submit written certification  statements  attesting

that proper installation procedures were used.


                         6.1   PROPER HANDLING PROCEDURES


    Citation


    As  specified  in  Sec.  264.192(b),  the owner  or operator  of  a  new  tank

system or a new component must:


    ...ensure  that proper  handling  procedures  are adhered to in order to
    prevent damage to  the  system during installation.  Prior to  covering,
    enclosing,   or  placing  a  new  tank  system  or component  in  use, an
    independent,  qualified  installation   Inspector  or  an  independent,
    qualified,   registered  professional  engineer,  either  of  whom is
    trained and experienced  in  the proper  installation  of tank  systems or
    component  [sic], must  inspect  the  system for the presence  of  any of
    the following items:

         1)   Held breaks;
         2)   Punctures;
         3)   Scrapes  of protective coatings;
         4)   Cracks;
         5)   Corrosion; and
         6)   Other   structural    damage   or   Inadequate   construction/
              installation.

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                                           OSWER  Policy Directive Mo. 94aj.GG-i

                                        6-2

    All  discrepancies  must  be  remedied  before  the  tank system is covered,
enclosed,  or is  placed in  use.
    Guidance

    The  intent  of  the Sec. 264.192(b)  regulation Is  to  ensure that new  tank
systems  and  components  are properly  handled  during   Installation  to  prevent
damage  that may  lead  to  or  cause  a  release  of waste  to  the   surrounding
environment.  This  Is to be  accomplished  by  inspection of  tank installation
procedures  by   a   qualified  tank   and   piping installation  inspector or   a
qualified,  registered  professional  engineer.    The   Installation   inspection
applies  to  both new  tank  systems  and  components,  where component means either
the tank or its  ancillary  equipment.

    The   regulations  require   that  an   Independent   qualified  installation
inspector or an independent  qualified,  registered  professional engineer, who
is trained in the  proper  installation procedures  for  new tank systems,  inspect
the  system  for  damage  prior  to covering,  enclosing,  or p>acing  it in  use.
(Refer to Section 10.0 of  this  document  for additional  guidance on  inspection
procedures.)

    A)   Installation Inspectors

    The  owner  or operator responsible  for installing  a new  tank  system  is
    required to obtain the  services  of a  qualified inspector.  Two  sources  for
    such services are manufacturers'  installation inspectors and  independent,
    registered professional engineers.

    Upon request,  most  reputable  tank   manufacturers  or  major  tank  system
    suppliers will  provide a qualified  installation  Inspector who  is  trained
    in  the  proper  installation  procedures  for a  procured  tank system.   Such
    individuals are   trained by  the  vendor and  have a working  knowledge  of the
    characteristics  of the  tank system  being  Installed,  as  well  as  knowledge
    of  proper  backfilling  and  compaction  procedures.   Since such a  person  is
    usually an employee  of  the tank  system vendor,  an  owner or operator  should
    obtain    written    documentation  regarding   the   qualifications  of   the
    installation  inspector and  the  services   that  will  be  provided.    Most

-------
                                        OSWER Policy Directive No. 9483.00-1

                                     6-3

     states do  not  yet  have  a licensing or  certification  program for tank
     system installation inspectors.

B)   Independent. Qualified.  Registered Professional Engineers

If  an  independent  installation  inspector  is not  retained by  an owner or
operator  to supervise  tank  system installation, an  independent,  qualified
professional  engineer  may certify  that  proper  installation  practices  are
followed.  Because  the regulations require the  engineer  to be independent,
he/she cannot be employed by  the  tank system owner or  operator,  in  order
to avoid a conflict of interest or the appearance  of such  a  conflict.  The
engineer  should be registered  to  practice  in  the state  in  which  the  new
tank system or  component  is  to be  installed.   Most professional  engineers
will provide  the  owner  or operator with a  resume  that summarizes relevant
training, experience,  and special  qualifications,  such as  previous  work in
soilsengineering,  corrosion  control, etc.   Generally,  civil,  chemical,
and  mechanical  engineers  are most  likely  to  have  had  appropriate  tank
system  training and  experience.    Some  consulting engineering firms also
can  be retained  to supply  professional   engineers who  are  qualified  to
provide one or more of the services required.

All  50 states  and the  District  of  Columbia  have laws  that  govern  the
practices  of  professional    engineers.     In  most   states,   registered
professional   engineers  are  required   to  stamp  or  seal   the  certification
documents  they  provide.   The  engineers  are  legally  responsible  for  such
certifications.

C)   Installation Inspection  Procedures

The  Sec.  264.192(b)  regulations   require  an installation Inspector or  a
registered professional  engineer to inspect a new  tank system or  component
for  weld  breaks;  punctures;  scrapes  of  protective  coatings;  cracks;
corrosion;  and   other  structural  damage  or  inadequate  construction   or
installation.    It   is advisable  to inspect  for these deficiencies  within
the context of  normal  tank  Installation procedures,  as  described  in  this
section.

-------
                                        OSWER Policy Directive No.  9483.00-1

                                     6-4

Normally, a tank, manufacturer or  supplier  arranges  for the transport  of a
new  tank  to the  installation  site  and retains the  responsibility  for the
tank until such time as it is delivered  and  accepted by the  buyer.   It  is
advisable to have  the  installation  inspector observe the  arrival  of a tank
at a  site  and  Its  off-loading from  the  tank  transporter.   While  the  tank
is  still  on the  transport  vehicle, an  inspector  should  visually  examine
the tank for:

     o    Weld breaks (steel  tanks);
     o    Punctures (all  tank types);
     o    Abrasions affecting protective coatings and/or  linings  (all
          tank types);
     o    Cracks (all tank types); and
     o    Corrosion (steel tanks), Internal and external.

Preinstallation handling  of  tank system components,  particularly  the tank
itself,  must  be done  carefully  so  that  the components  are   not  scraped,
dented, or  cracked.  Coatings  and welds on  steel tanks and the structural
integrity of fiberglass and  concrete tanks are particularly  vulnerable  to
damage from improper handling.

A  tank  should never  be  dropped,  handled  with  a  sharp   object,  dented,
dragged, or  rolled.  The  proper  way to  move  a  tank  is to  lift  it,  using
lifting  lugs  installed  by  the  tank  manufacturer.   Larger tanks  have
multiple  lifting  lugs,  and  all  of  them  should  be  used.   Cables or chains
of adequate  length  should be attached to  the  lifting lugs, and guidelines
should be  attached  to  the ends of  a tank  in order   to direct  its  movement
(see  Figure  6-1).   The intended  distribution of a  tank  load   among lifting
lugs   should  be   included   in   a  tank   manufacturer's   Installation
Instructions.  Generally,  however,   an  angle of not less   than  30 degrees
for tanks is desirable.  Lifting hooks should fit the  lifting  lugs and not
be oversized.  Shackles should be used if lifting hooks are  too large.

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                                              r'oiicy Directive  No.  948J.OO-I

                                    6-6

A  spreader  bar   to   separate   the  hoisting  chains   or   cables   at   the
appropriate angle  may  be used,  if necessary.  Cables,  chains,  or  slings
should not be wrapped  around a tank shell.

Fiberglass  reinforced-plastic  (RFP)  tanks  are  generally  more  vulnerable
to damage  (such  as  puncture holes) from improper  handling  than  are  steel
tanks.  Thus, an  inspector  should  be  particularly alert to  any instance of
mishandling prior to or during the  installation of an FRP tank..

Before  a   tank  is moved,  the capacity  and  reach of  hoisting   equipment
should be  checked.  A  tank  should  only be  placed  on  smooth  ground that is
free of rocks or  other hard, sharp objects  that  could  puncture  or  unduly
stress the  tank.   Rolling movement of a tank  lying  on  the  ground  prior to
installation should be prevented.     Refer  to  "Recommended  Practices  for
Installation of  Underground Liquid Storage Systems,"  Petroleum  Equipment
Institute, Document PEI/RP100-86, for  more  information on moving  tanks.

Immediately  after  unloading,   the   tightness   of  a  tank   should   be
demonstrated  (see  Section   6.3   below).    The  visual   inspection(s)   and
tightness  test will permit the inspector to Identify the defects  listed in
Sec.  264.192(b).

Damage and  defects  found  during  the installation  inspection or  during  the
tightness   test tends  to  occur at  points  of  high  stress,  e.g.,  at  seams,
lugs,  points  of  contact  with  the   ground,  couplings,  etc.   The  inspector
should note the  occurrence of any  high-dynamic  stresses  during off-loading
which, for  example,  can  be caused by  placing one tank end on  the  ground
before the other  end.  In  this  instance,  uneven placement could  cause  the
first  end  on the  ground  to bear  an  unexpectedly  large  load  for  a short
time,  thus damaging  the tank.   The   presence of  damage  or  defects  can
cause,  at worst,  tank system structural  failure.   Without repairs,  weld
breaks and  cracks  can  render a new tank  system useless in  a short time.
Less  severe  tank  system  failure  may occur  from excessive hoisting, causing
metal fatigue,  or from Inadequate corrosion protection  caused  by  damage to
a tank's  coating  or  to its  cathodic-protectlon system or to the  electrical

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                                        OSWER Policy Directive No. 9483.00-1

                                     6-7

Isolation  devices.   Inground and underground tank  systems  and components,
in  particular,  must be  inspected thoroughly  before  installation  because
the  portions  in  contact  with  backfill   are   generally  inaccessible  to
routine visual inspections after emplacement.

Excavation  design  is  also  critical   to  ensure  continued  tank  integrity.
The  Installation  Inspector  or professional  engineer  should  ascertain that
the  excavation side  slope,  depth of  excavation,  and distance from  nearby
structures  is appropriate.   Care must be taken to avoid undermining nearby
foundations   during   construction  or   afterwards   In  order   to   avoid
transferring  a foundation's  load onto the tank system.  See Figure 6.2 for
recommended distances from the nearest foundation.

After an inspection of the excavation for potential  sources  of tank  system
damage  has  been  completed  and  any deficiencies  corrected,  a tank  may be
lifted  into  its  service position.   The  procedures  described  above  for
lifting and  lowering a tank into place  also apply  to this  operation.  The
tank must  be  lowered evenly and placed  squarely  on the receiving  bedding
or   cradle,   depending  on   the  secondary   containment  design,   without
scratching, abrading, or otherwise damaging the tank (see Figure  6-3).

An  inspector  should  examine  a tank following  the attachment  of  anchoring
devices to  ensure  that  these  devices do not damage  the tank's  protective
coating.  A  checklist  of Inspection  details, including at  least  the  items
listed  in   Sec.  264.192(b),  should  be  completed  by the inspector.   (See
Figure 6-4.)

D)   Repairs

Sec. 264.192(b)  also  requires  that  any damage  to  a  new  tank  system  or
component  must be  remedied  prior to  installation.   Normally,  such  repairs
are  the  responsibility of  the  supplier or  an  authorized  representative.
The  tank owner or  operator  Is under  no  obligation  to use a tank  system or
component that does not meet specifications.

-------
                         6-3
                             D«pth of Foundation
                        Figur* 6-2
      Excavation Design: Recommended Distance from
                 the Nearest Foundation
FIGURES ARE FOR ILLUSTRATIVE PURPOSES ONLY THEY ARE NOT INTENDED FOR USE AS
CONSTRUCTION DRAWINGS.

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                                            OSWER Policy Directive No.  9483.00-1

                                         6-1

                      6.0   INSTALLATION OF NEW  TANK SYSTEMS
    Section 264.192(b-g)  requires  an owner  or operator" to ensure  that  proper
handling procedures are  used  to prevent damage to a  new  tank system or  a  new
component at  the  time  of installation.   Should damage occur  during the  course
of an installation, the owner or operator  must remedy it before  the  system is
fully installed or  placed  in  use.   The  Sec.  264.192(b-g)  requirements apply to
new tank systems  and  components.   The  terms  "new tank  system"  and  "new tank
component"   also    include   reinstalled  and   replacement   tank   systems   or
components.   The  professional  engineers  who  certify a  new,  permitted  tank
system's  design  and   those  who  supervise,   new tank  system  and  component
installation are required to submit written certification  statements  attesting
that proper installation procedures were used.

                         6.1   PROPER HANDLING PROCEDURES

    Citation
                                             •

    As  specified  in  Sec.  264.192(b),  the owner  or  operator  of  a  new tank
system or a new component must:

    ...ensure  that  proper  handling  procedures  are adhered to in  order  to
    prevent damage  to  the  system during installation.  Prior  to  covering,
    enclosing,  or   placing  a  new  tank  system or component  in  use,  an
    independent,  qualified  installation   inspector   or  an  Independent,
    qualified,  registered  professional  engineer,   either  of   whom  is
    trained and experienced  in  the proper installation of tank  systems or
    component  [sic], must  inspect  the system for the  presence  of  any of
    the following items:
         1)   Weld breaks;
         2)   Punctures;
         3)   Scrapes  of protective coatings;
         4)   Cracks;
         5)   Corrosion; and
         6)   Other   structural    damage   or   inadequate   construction/
              installation.

-------
                                                  roiicy uireccive  rto.

                                        6-2

    All  discrepancies must be  remedied  before  the  tank system  is covered,
enclosed, or is placed in use.
    Guidance

    The   intent  of  the Sec.  264.192(b)  regulation  Is  to  ensure that new  tank
systems   and  components   are  properly handled  during  Installation  to  prevent
damage  that may  lead   to  or  cause a  release  of  waste  to  the   surrounding
environment.   This  is to  be  accomplished  by  inspection of  tank  installation
procedures  by  a  qualified  tank  and   piping  installation   inspector or   a
qualified,  registered  professional   engineer.    The  Installation  inspection
applies   to  both  new  tank systems and components,  where component  means either
the tank or its ancillary equipment.

    The   regulations  require   that   an   Independent  qualified   installation
inspector or  an independent  qualified,  registered  professional engineer,  who
is trained in the proper installation procedures  for new tank  systems,  inspect
the  system  for  damage   prior  to  covering,  enclosing, or placing it  in  use.
(Refer to Section 10.0 of this  document  for additional guidance on  inspection
procedures.)

    A)   Installation Inspectors

    The   owner  or  operator responsible  for  installing  a  new tank  system  is
    required to obtain the services of a  qualified  inspector.   Two  sources  for
    such  services  are manufacturers' installation  Inspectors  and  independent,
    registered professional engineers.

    Upon  request,  most   reputable  tank  manufacturers or  major  tank  system
    suppliers  will  provide a qualified  installation  Inspector who  is  trained
    in  the  proper  installation  procedures  for a procured  tank system.   Such
    individuals are  trained  by  the vendor  and have  a  working  knowledge of the
    characteristics  of the  tank system being  Installed, as  well   as  knowledge
    of  proper  backfilling and  compaction  procedures.   Since  such a  person  is
    usually an employee of the tank system vendor, an  owner or operator should
    obtain   written    documentation  regarding   the  qualifications   of   the
    installation  inspector and   the  services  that will  be  provided.   Most

-------
                                        OSWER Policy Directive No.  9483.00-1

                                     6-3
      *
     states do not yet  have  a licensing or certification program  for  tank
     system installation inspectors.

B)   ^dependent. Qualified,  Registered Professional  Engineers

If  an  independent installation  inspector  is not  retained  by an  owner  or
operator to supervise  tank,  system installation,  an  independent,  qualified
professional  engineer  may certify that  proper  installation  practices  are
followed.  Because the regulations require the engineer to  be independent,
he/she  cannot  be employed by  the  tank system owner or operator,  in  order
to avoid a conflict of interest or the appearance  of such a  conflict.   The
engineer should  be registered  to  practice in  the state  in  which  the  new
tank system or component  is  to be installed.  Most  professional  engineers
will provide  the  owner  or operator with a  resume  that  summarizes  relevant
training, experience,  and special qualifications,  such as previous  work  in
soilsengineering,  corrosion  control, etc.   Generally,  civil,  chemical,
and  mechanical  engineers  are most  likely  to  have  had  appropriate  tank
system  training  and  experience.   Some  consulting engineering firms  also
can  be  retained  to   supply  professional   engineers  who  are qualified  to
provide one or more of the services required.

All  50  states  and the  District  of Columbia  have  laws  that  govern  the
practices   of   professional    engineers.    In  most   states,   registered
professional  engineers  are  required  to  stamp  or  seal   the  certification
documents  they  provide.   The  engineers  are  legally  responsible  for  such
certifications.

C)   Installation Inspection Procedures

The  Sec.  264.192(b)  regulations  require  an installation  inspector or  a
registered professional engineer to inspect a new  tank system or  component
for  weld  breaks;  punctures;  scrapes  of  protective   coatings;   cracks;
corrosion;   and   other  structural  damage  or  inadequate   construction   or
installation.    It is  advisable  to  inspect  for  these deficiencies  within
the  context of  normal  tank installation procedures,  as  described  in  this
section.

-------
                                        OSWER Policy Directive  No.  9483.00-1

                                    6-4

Normally,  a tank manufacturer or  supplier  arranges  for the transport of  a
new tank,  to the  installation  site  and retains the  responsibility for  the
tank until such time as it is delivered  and  accepted by the buyer.   It  is
advisable  to have  the  installation  inspector observe the  arrival  of  a tank
at a  site  and  its  off-loading from the  tank  transporter.   While  the  tank
Is still  on the  transport  vehicle, an  inspector  should  visually  examine
the tank for:

     o    Weld breaks (steel  tanks);
     o    Punctures (all  tank types);
     o    Abrasions affecting protective coatings and/or  linings  (all
          tank types);
     o    Cracks (all tank types); and
     o    Corrosion (steel tanks), internal and external.

Preinstallation handling  of  tank system components,  particularly  the tank
itself, must  be done  carefully  so that  the components  are   not  scraped,
dented, or  cracked.  Coatings  and welds on  steel tanks and the structural
integrity of fiberglass  and  concrete  tanks are particularly vulnerable  to
damage from improper handling.

A  tank should never  be dropped,  handled  with  a  sharp   object,  dented,
dragged, or rolled.  The  proper  way to  move  a  tank  is to  lift  it,  using
lifting  lugs   installed  by  the  tank  manufacturer.   Larger  tanks  have
multiple  lifting  lugs,  and  all  of  them  should  be  used.   Cables or  chains
of adequate length  should be attached to  the  lifting lugs, and guidelines
should be  attached  to  the ends of  a  tank  in order  to direct  its  movement
(see  Figure 6-1).   The intended  distribution of a  tank load  among lifting
lugs   should   be   Included   in   a    tank   manufacturer's   installation
instructions.    Generally,  however,  an  angle of not less   than  30 degrees
for tanks is desirable.  Lifting hooks should fit the  lifting  lugs and  not
be oversized.   Shackles should be used if lifting hooks are too large.

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                                        OSHER Policy Directive  No.  9483.00-1

                                     6-6

A  spreader   bar   to   separate   the  hoisting  chains   or   cables   at   the
appropriate angle  may be  used,  if  necessary.   Cables,  chains,  or  slings
should not be wrapped around a tank shell.

Fiberglass  reinforced-plastic  (RFP)  tanks  are  generally more  vulnerable
to damage  (such  as  puncture holes) from improper  handling  than  are  steel
tanks.  Thus,  an  inspector should  be particularly alert to  any instance of
mishandling prior to or during the  Installation of an FRP tank.

Before  a   tank  is moved,  the  capacity  and  reach of  hoisting   equipment
should be  checked.  A tank should  only be  placed  on smooth ground that is
free of rocks  or  other hard, sharp  objects  that  could  puncture  or  unduly
stress the  tank.   Rolling  movement of a tank  lying  on  the  ground  prior to
installation  should  be prevented.     Refer  to  "Recommended  Practices  for
Installation  of  Underground  Liquid  Storage Systems,"  Petroleum  Equipment
Institute, Document PEI/RP100-86, for more  information on moving  tanks.

Immediately   after   unloading,   the-  tightness   of  a   tank   should   .be
demonstrated  (see  Section  6.3  below).    The.  visual   inspection(s)   and
tightness test will permit the inspector to identify the defects  listed in
Sec. 264.192(b).

Damage and  defects  found  during the  installation  inspection or  during  the
tightness  test tends  to  occur at  points  of  high  stress,  e.g.,  at  seams,
lugs,  points  of  contact  with  the   ground,  couplings,  etc.   The  inspector
should note the occurrence of any  high-dynamic  stresses  during off-loading
which, for example,   can  be caused  by  placing one tank end on  the ground
before the other  end.  In  this  instance,  uneven placement  could cause  the
first  end  on  the  ground  to  bear  an unexpectedly  large load  for  a short
time,  thus damaging  the  tank.   The  presence of  damage  or  defects  can
cause,  at worst,  tank system  structural  failure.  Without repairs,  weld
breaks and  cracks  can render a new  tank  system useless  in  a short  time.
Less  severe  tank  system  failure may occur from excessive hoisting, causing
metal fatigue, or from inadequate corrosion protection  caused  by damage to
a tank's  coating  or  to its cathodic-protection system or to the  electrical

-------
                                        OSWER Policy Directive No. 9483.00-1

                                     6-7

isolation  devices.   Inground and underground tank  systems  and components,
in  particular,  must be  inspected  thoroughly  before  installation  because
the  portions  in  contact  with  backfill   are  generally  inaccessible  to
routine visual inspections after emplacement.

Excavation  design  is  also  critical   to  ensure  continued  tank  integrity.
The  Installation  inspector  or professional  engineer  should  ascertain that
the  excavation side  slope,  depth of  excavation,  and distance  from  nearby
structures  is appropriate.   Care must be taken  to avoid undermining nearby
foundations   during   construction   or   afterwards   in  order   to   avoid
transferring  a foundation's  load onto the tank system.  See Figure 6.2 for
recommended distances from the nearest foundation.

After an inspection of the excavation for potential  sources  of tank  system
damage  has  been  completed  and  any deficiencies  corrected,  a  tank  may be
lifted  into  its  service position.   The  procedures   described  above  for
lifting and  lowering a tank into place  also  apply  to this  operation.  The
tank must  be  lowered evenly and placed  squarely  on the receiving  bedding
or   cradle,   depending  on   the  secondary   containment  design,  without
scratching, abrading, or otherwise damaging the  tank (see Figure 6-3).

An  inspector  should  examine  a tank following  the attachment  of  anchoring
devices to  ensure  that  these  devices do not damage  the tank's  protective
coating.  A  checklist  of inspection  details, including at  least  the  items
listed  in   Sec.  264.192(b),   should  be  completed  by the inspector.   (See
Figure 6-4.)

D)   Repairs

Sec.  264.192(b)  also  requires  that  any damage  to  a  new  tank  system  or
component  must be  remedied  prior to  installation.   Normally,  such  repairs
are  the  responsibility  of  the  supplier or  an  authorized  representative.
The  tank owner or  operator  is under  no  obligation  to use  a tank system or
component that does not meet specifications.

-------
                                                       t 1 *
                         6-3
                             0«ptti of Foundation '
                         Figure  6-2
      Excavation Design:  Recommended Distance from
                 the Nearest Foundation
f IGURES ARE FOR ILLUSTRATIVE PURPOSES ONLY THEY ARE NOT INTENDED FOR USE AS
CONSTRUCTION DRAWINGS.

-------
                                    6-9


                              Figure 6-3

                             Excavation
Unstable
Soil
                             Secondary Containment
                                   Liner
                                                    Note: • Space In accordance with
                                                          manufacturer's installation
                                                          Instructions
  FIGURES ARE  FOR  ILLUSTRATIVE PURPOSES ONLY. THEY ARE NOT INTENDED FOR USE AS
  CONSTRUCTION  DRAWINGS.


                                   OSWER Policy Directive   9483.00-1

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                                                  fji;cy ui receive .No. 9-co.GG-
                                       6-10
                                  FIGURE 6-4
                          TANK  INSTALLATION  CHECKLIST


    This checklist  is  intended to provide  guidance to  installation  inspectors
    regarding minimum requirements for proper underground tank installation.


                                                       Completed  Initials  Date

1.  Tank Delivery

    1.1  When  the   tank'  is  delivered,  inspect  the
         tank  on   the   carrier  vehicle   for   weld
         breaks,   punctures,   scrapes  of  protective
         coatings,    cracks,    corrosion   or   other
         Structural   damage.    Check   stress  points,
         such  as  tie  downs,  anchor blocks,  cradle
         supports,  etc.                                    [ ]

    1.2  Observe  off-loading  of  tank  for  conform-
         aacss to  manufacturer's  recommended  proce-
         dures.   If applicable,  check  intermediate
         placement   of   tank  on  ground  surface  for
         proper support, absence of  sharp objects etc.     [ ]

    1.3  Observe  preinstallation air  pressure  tight-
         ness test.   Record results,  method(s)  used.       [ ]

    1.4  Observe   final    lifting  and   placement  in
         excavation.  Look for  same  items  as  in 1.1
         and 1.2  above.                                    [ ]


2.  Excavation

    2.1  Check  completed   excavation  for   general
         conformance    to   manufacturer's    and/or
         engineer's   drawings   and   specifications;
         include  size  (width,  length,  depth),  side-
         wall  clearances/slopes,  shoring  and  other
         factors  of  excavation  geometry.                  [ ]
    2.2  Consult  local   agencies   for   information
         regarding  water  taole  depth/fluctuations.
         Check  excavation and excavated material  for
         evidence  of  high  ground   water   conditions
         (soil   moisture),   visible   standing   water.
         If  unusual   soil   conditions  are   found,
         notify owner  or designated  representative.        [  ]

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                                            OSWER Policy Directive No. 9483.00-1

                                        6-11


                               FIGURE 6-4--CONTINUEO

                                                       Completed  Initials  Date
    2.3  Observe  installation  of  secondary  contain-
         ment  liner  or  vault  in  accordance  with
         engineer's  and/or  manufacturer's plans  and
         specifications.                                  [ ]

    2.4  If   appropriate   monitor   installation   of
         anchor   bedding,   supports,   anchor   slab,
         anchor tie  downs,  etc.,  in  accordance  with
         engineer's plans  and specifications.              [ ]

    2.5  Monitor   placement   of   bedding  material
         (sand, pea  gravel,  etc.)  in accordance  with
         engineer's  and/or  manufacturer's plans  and
         specifications.  Check  depth,  distribution,
         characteristics  of  material  (noncorrosive,
         porous,  homogeneous).                             [ ]
3.   Backfilling

    3.1   Monitor backfilling  so that  tank  is  fully
         *ftd-uniformly supported.  Make  sure  no void
         spaces are left under  the tank  as  backfill-
         ing  progresses.   Monitor   for   consistent
         placement/compaction.  '                          [ ]

    3.2   Observe  that  backfilling   fully  and   uni-
         formly supports  piping,  secondary  contain-
         ment  installation  and  appurtenances  there-
         to.   Monitor   for   consistent   placement/
         compaction.                                       [ ]

    3.3   Observe  final   tightness  testing  of  tank,
         piping and ancillary system  equipment  prior
         to  its   being   covered,   enclosed   and/or
         placed in  use.                                    [ ]

    3.4   Monitor  final   backfill  placement.    Make
         sure  depth   of  cover  meets  manufacturer's
         and/or engineer's  specifications.                 [ ]
4.   Corrosion Protection

    4.1   Cathodic  Protection—observe that  corrosion
         protection  system  installed meets  require-
         ments established by the  independent  corro-
         sion expert,  retained  by  the  owner/opera-
         tor,  and,   if   applicable,   by   the   EPA
         Regional  Administrator.                           [  ]

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                                        6-12


                               FIGURE 6-4--CONTINUED
                                                       Completed   Initials   Date
    4.2  Installation  of  Field  Fabricated  Systems-
         observe  that  field-fabricated,  corrosion-
         protection  system  installation  is  super-
         vised by  the  selected  independent corrosion
         expert.                                          [ ]


5.  Piping/Equipment Installation

    5.1  Monitor  installation  of  piping,  valving,
         pumps  and  other  equipment ancillary  to the
         tank and  the secondary  containment  facili-
         ties.   Make  sure  it  is  accomplished  in
         accordance  with  engineer's  and/or  manufac-
         turer's  plans and  specifications and  with
         local  building  and  other applicable  codes
         and regulations.                                  [ ]

    5.2  Observe  that  testing  of  such  equipment  is
         accomplished  properly   and   in  accordance
         with 3.3 above.                                   [ ]


6.  Repairs

    6.1  Note   separately   any   deficiencies   found
         during  the  installation  process and  provide
         complete information regarding any repairs.      [ ]


7.  Certification

    7.1  Provide  owner/operator  with  certification
         of  design   and   installation   of  tank  in
         accordance  with  federal  and  state  require-
         ments.   Provide   any   local   certifications
         required.                                        [ ]


8.  Comments

    8.1  Provide an  "as-built" drawing  to  a  scale of
         1"-10'   showing  the location  and  character-
         istics   of  the   tank   installation.   Use  a
         separate  sheet   if necessary.   Also,  note
         any   unusual   conditions   and/or   system
         operating conditions.                             [ ]

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                                            OSHER Policy Directive No. 9483.00-1

                                        6-13

    Minor repairs  can  be performed on-site by the supplier, such as structural
    repairs  to  small  weld  cracks  or  chipped  fiberglass   coatings.    If  the
    damage  is major  or  irreparable,  the  tank  system  or  component  should be
    rejected.  Under no circumstances  should such a  tank  system  or  component
    be placed  into use.

                                6.2  BACKFILLING

    Citation

    Section  264.192(c)  specifies  the   requirements  for backfill  material  and
the backfilling process for a new underground tank system or component.   These
requirements  were  developed to minimize the  possibility  of external  corrosion
from the surrounding environment  and  to ensure  that  the  equipment is properly
supported.   Section 264.192(c) states:

    New  tank  systems  or  components  that  are  placed underground  and that are
    backfilled  must   be   provided   with  a   backfill   material  that   is  a
    noncorrosive,  porous,  homogeneous  substance and  that is  over  installed so
    that the  backfill  is placed  completely  around  the  tank and  compacted to
    ensure that the tank and piping are fully and uniformly supported.

    Tank manufacturers often provide  installation  specifications  for backfill
material and  placement.   Prior to  installation, the inspector  of a  new  tank
system  should  include  on  the  inspection  checklist  an  examination of backfill
material and placement.

Guidance

    A)   Backfill Material

    For  an  underground  tank  installation, all  excavated  native  soil must be
    replaced  with  appropriate backfill material.  Backfill  below,  around,  and
    above  a   tank  should  be  homogeneous,   clean,   and  properly  compacted.
    Backfill material  for  steel  and  composite tanks  is  different from that for
    nonmetallic  tanks.   The use  of inappropriate backfill  material can  void  a
    tank  manufacturer's  warranty.   Backfill   suppliers  should  be   able  to

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                                              roiicy uireccive No.  a4oJ.oo-l

                                    6-14

certify material characteristics.   "Recommended  Practices  for Installation
of  Underground  Liquid  Storage   Systems,"  Petroleum  Equipment  Institute,
Document PEI/RP100-86  may be used  as guidance  on  backfill  selection  and
installation.

In general,  a  steel  or composite tank requires  backfill  that  is  composed
of  washed,   well-granulated,  free-flowing  sand  or  gravel.   The  largest
particle should  not be  bigger  than  1/8  of  an  inch,  not  more  than  five
percent by  weight,  and  should  be  able  to pass through a  #200  sieve.   In
freezing conditions, the backfill must be dry and free of ice and snow.

For a nonmetallic tank, the backfill should consist of  pea  gravel,  defined
as rounded  particles  with a diameter between  1/8 and  3/4  inch, or crushed
rock  or gravel,  defined  as  washed  and   free-flowing,  angular  particles
between 1/8  and  1/2 inch.  Not more than three percent by weight should be
able to pass through a  sieve.   As with the backfill for metal  tanks,  this
backfill must be dry and free of  ice and snow.

B)   Backfill Placement

An underground  tank and its backfill act together to provide the necessary
structural   support   for  tank   contents  and  external   loads.   Tanks  are
designed to be flexible  and  to  deflect  slightly,  displacing  backfill  in
response  to  loading.    Thus,   because  a  tank  is  designed  to  deflect,
backfill must  be placed  and  compacted  uniformly  around the  tank  so that
excessive stresses  are  not created  in any portion  of  the  deflecting tank.
A  tank  must not  be filled before  backfill  is In place to  the  top  of  the
tank.  After the backfill  is added up to the top of  the  tank, either water
or  the  product to be  stored must be added as ballast.  At  that time,  the
ballast will  keep  the  tank in  place  until  piping  and the  rest  of  the
backfill is  installed.

The dimensions  of a tank  excavation  are  important.   The hole must be deep
enough  to  contain  graded  and  leveled  backfill  bedding of  at least  six

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                                        OSHER Policy Directive No. 9483.00-1

                                    6-15

inches for  a  steel  tank and one  foot  for  an FRP tank.  At  least two feet
of  backfill,  or  not  less  than one  foot  of backfill  and four  inches  of
reinforced  concrete,  must be  placed  above  a  tank  in  a  non-traffic  area

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                                        OSWER Policy Directive No.  9483.00-1

                                    6-16

exist  around  the  base  of  a  tank,   nor   should   intermediate   supports
(saddles)  be  used  because  these  features   can  magnify  the  effects  of
structural  loading  and  can cause  a  tank  to  rupture  (see  Figure  6-5).
Moreover,  water  can  accumulate  in  a void,  causing  accelerated  local
corrosion.   A  long  compacting  tool  or probe can  be  used  to   compact
backfill   under   a   tank.   Sand  backfill    usually  requires  mechanical
compacting to  provide  adequate  tank  support  and to  reduce  the  possibility
of voids forming under a tank.

An excavation  will  fill  with  water  if the  ground-water table  Is  high.   A
tank  can  be  installed  under  such  conditions,  however,  with  appropriate
anchoring,  ballasting  immediately  after backfill  reaches  the tank  top,
and/or dewatering of the excavation pit.  Ballast level  in a  tank  must -not
exceed  the  water level  in  the excavation.   If dewatering  is required,  an
experienced  professional  engineer, geologist,  or  hydrogeologist should  be
consulted.   See  also,   "Construction  Dewatering,   A  Guide  to Theory  and
Practice," (1981) by  J.P.  Powers,  published  by John  Wiley and Sons,  Inc.
(New York, NY).

Permanent   tank   anchoring   may   be   required  with   this   environmental
condition.   If a hold-down pad is used (see  Section 5.1 of this document),
one  foot  of compacted  backfill  base  should  be placed on top of  the pad
before seating a tank.

Once  a  tank  has  been  firmly  seated  on its   backfill  base and the  tank's
ancillary  equipment  installed,   the  balance  of  backfill  may be  placed.
Homogeneous  clean  sand, pea  gravel,  and   crushed  rock  are  relatively
self-compacting  and  are  easy  to place.  Any debris  in the  backfill,  such
as concrete  chunks or rocks, can prevent local  deflection  of  a tank shell,
which  can  cause the   tank  to  fail.   Such   debris must  be  removed  from
backfill.  Native soil  taken from  a  tank excavation should  not be  used as
backfill,  unless its  noncorrosiveness  and  porosity are  approved  by the
installation  inspector  or  the  registered   engineer  who  supervises  tank
system or component installation.

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                                   6-17


                              Flgur*  6-5

                               Backfill
                                                    .Secondary
                                                    Containment
                                                    Liner
                                                   WRONG
                         Bedding
Void Sptce
 I
O
q
«
09
f
Ot
                                                                                  O

                                                                                  "o
                                                                                  a
                                                                                  to
                                                                                  o
FIGURES ARE FOR ILLUSTRATIVE PURPOSES ONLY. THEY ARE NOT INTENDED FOR USE AS

CONSTRUCTION DRAWINGS.

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                                                      cy  Directive  No.  943J.UO-I

                                        6-18

             6.3  PRE-SERVICE TANK AND ANCILLARY EQUIPMENT TESTING

    Citation

    Tightness  testing  of  a  tank  and   Its  ancillary  equipment  can  prevent
leaking  equipment  from   being   placed   into  operation.    Section  264.192(d)
requires that:

    All new  tanks and ancillary  equipment must be  tested for  tightness
    prior to being  covered,  enclosed, or placed in use.   If a tank system
    is found not to be  tight, all  repairs necessary to remedy  the  leak(s)
    in  the   system  must  be  performed   prior   to  the tank  system  being
    covered, enclosed,  or placed into use.

    Tests for tightness should be performed by  leak-testing experts.

    Guidance

    A)   Tanks

    All new tank systems  must be  tested  prior  to being placed  in  service.   It
    is particularly important that  a tank system  that will  be in  contact  with
    backfill or soil is  tested  for  tightness  because  this type of system  will
    later be inaccessible to routine visual inspections.

    For  aboveground,   onground,   and  inground  tanks,   testing for  tightness
    should  be  done  at  operating  pressure  using  air,   inert  gas,  or  water.
    Tightness test  procedures for  a double-walled  tank should  be  conducted  in
    a manner approved  by the tank  manufacturer.   Generally,  these  procedures
    involve testing both  the primary and secondary shells simultaneously.   Air
    pressure testing should not  be used  for underground tanks  that are already
    buried.   An underground tank should  be tested for  tightness hydrostatically
    or with air pressure, before being placed in the ground.

    To  perform  a  tightness  test,  all  factory-installed  plugs  should  be
    removed, doped, and  reinstalled,  and all  tank fittings must  be  tightened.
    Replace  all  metal  or  plastic  thread  protectors  with liquid-tight,  cast

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                                        OSWER Policy Directive No.  9483.00-1

                                    6-19

iron  plugs.    All   surfaces,  seams,  fittings,  and  visible  dents  must  be
thoroughly  soaped   and  carefully  inspected  for  bubbles  during  an  air  or
inert gas  pressure  test.   A pressure gauge  that  accurately  measures small
changes  in  pressure  (less  than  1/2  psi)  should  be  used.   For  an  air
pressure test,  air  pressure  should not be less  than  3  psi  (20.6  kPa)  and
not more than  5 psi (34.5 kPa); air  testing with over  5 psi  may  damage a
tank.  An air  pressure  test  should not be performed on equipment  that  has
contained  flammable or  combustible  material.    Never  conduct a  negative
pressure  (partial   vacuum)  test  and  never  leave  a   tank  under  test
conditions   unattended.   See  also,  "Flammable  and  Combustible  Liquids
Code," NFPA 30, (1984).  A registered  professional  engineer  should approve
any deviations  to  these testing guidelines (for example,  vacuum test might
be considered for an ASME pressure vessel).

B)   Piping

Piping (aboveground  and  underground,  prior to installation)  may  be  tested
hydrostatically at  150  percent  (but not less than. 50 psi) or pneumatically
at  110  percent of  the  maximum  anticipafed   system  pressure.  The  piping
must be  disconnected  from the  tank, and all  joints, connections,  and dents
must be  thoroughly  soaped.   The test must be  maintained  for  a  sufficient
time to  complete a  visual inspection of all  joints, connections,  and dents
for bubbles, usually 30 to 60 minutes.  American  Petroleum  Institute (API)
Publication  RP 1110,  "Recommended Practice  for  the  Pressure -Testing  of
Liquid Petroleum Pipelines,  Second Edition"   (1981)  may serve as  guidance
for hydrostatic testing of piping.

C)   Repairs

Before a tank  system is placed in use, all leaks discovered during testing
for  tightness  must be   remedied.   Minor  tank  damage  can  be  corrected
onsite,  but  a  major defect may render  a  tank system unusable.  A repaired
tank and/or piping  should be retested before  burial.

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                                            OSHER Policy  Directive  No.  9483.00-1

                                        6-20

                      6.4  ANCILLARY  EQUIPMENT  INSTALLATION

    Citation

    Proper  ancillary  equipment  Installation   practices  further   ensure   the
Integrity of  a  tank  system.   Section 264.192(e) regulates these practices,  as
follows:

    Ancillary  equipment  must  be  supported   and  protected  against  physical
    damage  and  excessive  stress  due to settlement,  vibration,  expansion,  or
    contraction.

    Guidance

    Faulty  installation of  piping and pipe fittings  is  a  major  cause of leaks
and spills  at hazardous  waste storage facilities.  Proper ancillary  equipment
installation  is required to satisfy Sec. 264.192(e).

    Both  aboveground  and   underground   ancillary  equipment  is   subject  to
mechanical  and  thermal  stresses.   Underground piping  is  generally,  however,
more uniformly  supported  and  thus is somewhat  better  protected  from excessive
stress.  Examples of mechanical stress include   vibration surges  in  liquid  flow
(water  hammer),  ground   subsidence,  seismic  activity,   and   wind  blowing  on
aboveground piping.  Thermal stresses are attributable to  climatic  changes and
the presence of heated or cooled fluids or equipment.

    A  piping  trench  should  be  situated  so   that  It does  not  pass  over any
underground  tanks and  so  piping  leaves  a tank  excavation   by  the  shortest
route,  minimizing crossing of  any  underground  tanks.   A  piping  route  should
also be arranged  to minimize the distance between inlet and outlet,  and  as few
trenches  as practical should  be  constructed.   Each  trench should  be at least
twice as wide as  the nominal piping diameter.

    Connections between the pipe lengths and between the tank  and  piping are a
frequent  source of  leaks.   If connections are not  secure,  pipeline stresses
will  be transmitted  to  ancillary equipment.    When  pipe  is  screwed  together,

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                                            OSWER Policy Directive No. 9483.00-1

                                        6-21

thread  lubricant  (pipe  dope)  is  "necessary  to  ensure  that   the  piping  and
fitting  are  mated to  the  proper  depth  and that  a  tight  seal  has  been made.
The  lubricant  also  provides  some  degree  of  protection  against the  crevice
corrosion  that  can  occur  at such  joints; where threads  are joined,  the union
of two metals with just slightly different properties can  result  in  a galvanic
cell that will  corrode if not protected.

    FRP  joints  should  be  glued,  except  where  transitions  to  pumps  and
emergency  shutoff  valves  are  made.   Relatively  thin-walled,  Schedule  10
stainless  steel  pipe may  be used  for low-pressure piping, and  the  joints for
such  piping should   be  welded.   Welding  stainless  steel  is  an  operation
requiring   considerable   skill  and   attention   to  detail.    Where  screwed
connections  are  required,  such  as  for  the  pump connection,  a  transition  to
Schedule 40  pipe  must be made.  The  Schedule  40 pipe has sufficient thickness
to allow for pipe threads to be cut.

    The joining methods for double-walled piping  include  flanges,  welding, and
resin-gluing.  The exact method depends on the specific type of piping chosen.
Manufacturers'    specifications  should   be   consulted   for   more   detailed
information.

    Aboveground piping must  be properly  supported through  the  use  of anchors,
hangers,  or  other  supporting  elements   that   can   withstand   the   expected
mechanical   loadings.   Additionally, aboveground ancillary  equipment  should  be
located  in  protected areas  so that  any  projecting  parts  are  not damaged  by
moving  equipment  or  traffic.   It  is recommended  that  aboveground  valves  be
Installed with  the stem  upright or, at worst, horizontal,  to  prevent sediment
from  becoming  trapped and  damaging the  stem.   Moreover,  freezing  can  rupture
parts of an  inverted valve.

    Piping supports must be  designed  not to cause excessive  local  stresses  in
piping  and  not  to   Impose   excessive  axial  or  lateral  friction  forces.   All
piping attachments must  be  designed to minimize the  stresses  they  could cause
in  the  pipe wall.   Nonintegral  attachments,   such  as  pipe  clamps  and  ring
girders  are preferred,   if   they  can  fulfill  the  necessary  supporting  or
anchoring functions.

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                                            OSWER Policy Directive  No.  9483.00-1

                                        6-22

    Braces and damping devices  may  occasionally be required to prevent  piping
vibration.   If  piping  is  designed  to operate  at or  close  to its  allowable
stress,  all  connections welded to  the piping  must  be  made  to  a  separate
cylindrical   member   that  completely  encircles  the   piping.   This  encircling
member must be welded to the  piping  using  continuous,  circumferential  welds.

    In order  to  protect  underground  piping, backfilled trenches must  be  large
enough  to  accommodate  at  least  six  Inches  of  backfill  around  each  line.
Underground pipelines should be  covered by at least  12  inches  of backfill  in
an area  without  traffic  and  by at least 18 Inches of backfill  in  an area with
traffic.  Vent piping should be at  least  12  inches  below  the ground  surface,
beginning from the  point where the  piping  rises vertically (or  four inches  in
a no-load area).   Aboveground  vent  piping  should be  placed  in a  location -that
protects  it from  traffic and other  sources of damage.  All  piping  should slope
at least  1/8  inch  per foot horizontal  toward  the  tank, and  piping  should  be
carefull_y_ laid  to avoid sags  or  traps  in  the line that could  collect liquid.
Manufacturers' instructions for  installation  of non-metallic  piping  should  be
followed explicitly.

    Bedding and  covering  backfill  for  buried piping  should  be composed of a
single material,  similar to  the tank backfill  materials  described  in Section
6.2.    Backfill  compaction  and   placement  specifications are  also  the  same  as
for underground  tanks.  Special  care  must   be  taken  to remove  all  debris  when
compacting over nonmetallic piping.

    Breakage  of  underground  piping  and vent  lines  and the  loosening of pipe
fittings that can cause  leaks can be minimized through the  use of  swing joints
or  some  other  type of flexible  coupling.  Swing joints  should  be  Installed
where piping is connected to an  underground tank,  where piping ends  at  a vent
riser,  and  where piping changes  direction.   Swing joints  should be  made of a
short nipple, together with  a  combination  of the  following fittings:   two 90°
elbows;  one  90°  elbow  and  one 45°  elbow; either a  90° or a 45' elbow  and a
tee;   a  flexible  connector  approved  for  the   application.    Unless  local
regulations  require swing  joints for  all  FRP  piping, swing  joints  are  not
required  if  at  least   4   feet  of  straight-run  piping  provides   for  any
directional  change exceeding 30 degrees.

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                                            OSHER Policy Directive No.  9483.00-1

                                        6-23

    All  piping  systems   should  also  be  designed  to  prevent  expansion  or
contraction from  causing excessive  stresses  and  bending  in  the  system.   For
example,  if  significant   temperature  changes  are  expected,  such  as   in  pipes
carrying  heated  wastes,  the  piping  system  possibly  should   include  anchors
and/or extra  bends,  expansion  joints, expansion loops, etc., for  flexibility.
Aboveground piping can be protected from expansion and contraction in  the same
way as  buried  piping,  but it  requires  consideration  of beam-bending  stresses
and  the  possible elastic  instability of  the  piping  and  its supports  from
longitudinal  compressive  forces.

    The following references can  greatly assist in the  installation of piping
system supports and protection:

    o    API   Publication  1615, "Installation of Underground  Petroleum Storage
         Systems" (1979);
    o   _ANSI  Standard B31.3, "Petroleum Refinery Piping" (1986);
    o    ANSI  Standard 831.4,  "Liquid  Petroleum  Transportation  Piping  Systems"
         (1980);
    o  ' Petroleum   Equipment    Institute   (PEI),    Standard    PEI/RP   100-86.
         "Recommended Practices for Installation of Underground Liquid Storage
         Systems" (1986), and;
    o    Piping manufacturer installation instructions.

Figures 6-6 to 6-8 present examples of piping system installation details.

                  6.5   CORROSION  PROTECTION  SYSTEM  INSTALLATION

    Citation

    To  ensure  that  a  new tank system has  adequate  corrosion  protection,  the
owner or operator must use  a corrosion expert  to  supervise field  fabricated
installation  of  corrosion protection,  particularly  for a  cathodic  protection
system.  As specified in  Sec. 264.192(f):

    The owner  or  operator must provide the type and  degree of corrosion
    protection  recommended  by  an  independent  corrosion expert,  based on

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                                        6-24
                                      Vents
Piping w/Secondary
Containment \
    Stop* to
    Drain to
         Explosion Proof
         Motor and Pump
                                                           Berm
                                                     Secondary Containment
                                                     Liner
              Leak Detection
              Device
          \
                Reinforced Concrete
                Foundation
           Sump

Undlaturfoed.Sofl
                                                              Figure 6-6


                                                        Partially Buried Vertical

                                                        Hazardous Waste Tank
                                                        with Secondary Containm
                                    OSWER Policy Directive  9483.00-1
        FIGURES ARE FOR ILLUSTRATIVE PURPOSES ONLY. THEY ARE NOT INTENDED FOR USE AS

        CONSTRUCTION DRAWINGS.

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                                6-25
                              Figur* 6-7
               Underground Tank and Piping  System
                                                                   < z
                                                                   -JO
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                                            OSWER Policy Directive Mo.  9483.00-1

                                        6-27

    the information provided  under  paragraph (a) (3) of  this  section  or other
    corrosion  protection   if  the   Regional   Administrator  believes   other
    corrosion  protection   is  necessary to  ensure  the  integrity  of  the  tank
    system  during  use of  the tank system.   The installation of a  corrosion
    protection  system  that   is  field  fabricated  must  be  supervised  by  an
    independent corrosion expert to ensure proper installation.

    Guidance

    Using the information obtained for the  requirements of  Sec.  264.192(2X3),
an  independent   corrosion  expert   (defined  in  Section 5.1)  will  be  able  to
determine  corrosion  protection  needs  of  a  tank  system  for   its  intended
lifetime.    A  corrosion expert must oversee the  installation of  any corrosion
protection  devices,   particularly   cathodic   protection,   that   are   field
fabricated for a new tank system.

    Information  on  cathodic-protection   system  construction,   inspection,
handling,  electrical  isolation, and installation details  can  be  found  in  the
National   Association   of  Corrosion  Engineers   (NACE)   Sta-ndards   RP-02-85,
"Recommended  Practice—Control   of  External 'Corrosion  on  Metallic   Buried,
Partially  Buried,   or  Submerged   Liquid  Storage  Systems"  (1985);  RP-01-69,
"Recommended  Practice—Control   of  External   Corrosion   on  Underground   or
Submerged   Metallic  Piping  Systems"   NACE   (1983),  and   Petroleum  Equipment
Institute    (PEI)    standard   PEI/RP   100-86,   "Recommended   Practices   for
Installation  of  Underground  Liquid  Storage  Systems"  (1986).    (See  document
Section   5.4   for   additional   information   on   cathodic-protection   system
installation.)

                 6.6  CERTIFICATIONS OF DESIGN AND INSTALLATION

    Citation

    Following installation,  Sec.  264.192(g) requires the owner or  operator  of
a new tank system to:

    ...obtain and  keep on file  at the  facility written  statements by  those
    "persons" required  to  certify  the design of  the  tank  system  and supervise
    the installation of the tank system in accordance with  the requirements  of
    paragraphs  (b)  through  (f)  of this section,  that  attest  that  the  tank
    system  was properly  designed  and  installed  and  that  repairs,  pursuant  to
    paragraphs  (b)  and  (d)   of  this  section,  were performed.   These  written

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                                            OSWER  Policy  Directive  No.  9483.00-1


                                        6-28


    statements must  also  include  the certification  statement  as  required  in
    §270.ll(d) of this Chapter.


    Guidance


    The  professional  engineer   who  certifies  a  tank   system's   structural

Integrity,  the  installation  inspector,  the  tightness  tester,  the  corrosion

expert,  and anyone  else   who  has  supervised  a   portion  of  the  design  and

Installation  of  a new tank  system  or component must document that  the  system

Is  in  accordance with  the  requirements   of  Sec.   264.192(a-f).    Materials

accompanying   and  supporting  these   statements   might  include   "as-built"

installation drawings and  photographs  of tank and  piping  components.


    A s-ample  statement of  the form  required by Sec.  264.192(g),  including'the
Section 270.11(d) truthfulness certification, follows:


          I,  [Name],   have  supervised  a  portion  of  the  design  or
    installation  of   a new  tank  system  or  component   located  at
    [Address],  and  owned/operated  by  CName(s)].   My duties  were:
    [e.g.. preinstallation inspection, testing  for  tightness,  etc.],
    for  the  following tank  system  components  [e.g.,  the  tank,  vent
    piping,  etc. 3.  as  required  by  the   Resource  Conservation  and'
    Recovery  Act  (RCRA)   regulation(s),   namely,   40  CFR   264.192
    [Applicable Paragraphs (i.e.,  a-f)].

          I certify  under penalty  of  law  that  I  have  personally
    examined  and  am  familiar with the information  submitted  in  this
    document  and  all   attachments and that, based  on my  inquiry  of
    those  individuals  immediately  responsible  for  obtaining   the
    information,  I believe that  the  information  is  true,  accurate,
    and  complete.   I  am  aware  that  there  are  significant penalties
    for  submitting  false   information,  including  the  possibility  of
    fine and imprisonment.
                                     Signature
                                     Title
                                     Registration No., if applicable


                                     Address

    The certification  statements  must  be kept on file indefinitely at the tank
facility,  as specified in Sec. 264.192(g).

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                                            OSHER Policy Directive No.  9483.00-1

                                        6-29
                                  •
                  5.7  DESCRIPTION OF TANK SYSTEM INSTALLATION

    Citation

    For  the  Part B  application  the  owner or operator must  provide  a  detailed
description of  how  a  new tank  system  will  be  installed,  in accordance  with
Section 270.16(f):

    Sec.  270.16(f)   for  new tank, systems,  a detailed  description of  how  the
    tank  system(s) will  be  Installed in  compliance with  Sec.  264.192(b),  (c),
    (d), and (e);
    Guidance

    Section  270.16(f)  requires  that owners  or  operators  provide  a  detailed
description of the tank  system installation with respect to  the  tank  handling
and  installation  procedures,   the   type  and   installation  of  backfill,  the
tightnesT"testing results and  methodology, and  the installation  of ancillary
equipment.   This  description  must   be  sufficiently detailed  for  the EPA  to
determine  if  the   tank  and  its  ancillary  equipment,  as  installed,   have
sufficient  integrity to prevent  releases of waste  to the  environment  during
use.   The  description  should  describe  handling  and  lifting  methods   used
on-site  and  precautions  taken  to  avoid  weld  breaks,  punctures,  scrapes  of
protective  coatings,  cracks,  corrosion,  and   other   structural   damage.    The
description should  also  include  precautions  taken to avoid  future  damage  due
to  settling,   high  water  tables,   frost  heave,  vibration,  expansion,   and
contraction.   For the  tightness  testing,  the  description  should  include  the
methodology, the results, conclusions, and any  recommendations  made  or actions
taken as a result of the testing.

                          6.8  SUMMARY OF MAJOR POINTS

    The  following  summarizes  the   information  covered  in   this  section  and
should be used to assure the completeness of a Part B permit  application:

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                                                     LM I ec I. I Vfc fIG.
                                    6-30
o    Is  the  installation  inspector or  registered engineer  qualified  to
     inspect a  new tank  system  or component  prior  to  installation?   Can
     this  individual  discriminate   between   reparable  and   irreparable
     damages and defects?  Can he/she assess the adequacy of a repair?

o    Has  he/she  Inspected  the  tank  system  during  installation  for  the
     presence of at least the following:

     —  Weld breaks;
     —  Punctures;
     --  Scrapes of protective coatings;
     --  Cracks;
     —  Corrosion; and
     —  Other structural damage or inadequate construction/installation.

     Have all  such  problems  been remedied  before  the  system  was  placed in
     use?

o    Is   the   backfill   noncorrosi ve,   porous,   homogeneous?   Are   the
     dimensions  of the  tank  excavation adequate?   Has the  backfill  been
     placed and compacted carefully around  the tank?

o    Does the tank pass a test for tightness?  Does the  piping system pass
     an analogous test?

o    Is  the  piping  system  adequately  supported and  protected  against
     damage from external and internal loads?

o    Has  a  corrosion  expert  supervised  the  installation  of any  field-
     fabricated   corrosion   protection,   particularly  cathodic-protection
     devices?

o    Have statements  been written by the appropriate  personnel  to  certify
     that the  tank system  is properly designed  and  installed?   Are these
     statements on file at the facility?

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                                            OSWER Policy Directive No. 9483.00-1


                                        6-31


         Has  a  detailed  description  of  the  tank-- system  installation  and

         tightness testing been provided?
In  addition,  see  Appendix  A,  "Completeness  Checklist," to  verify compliance
with the requirements of this section.

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                                             OSHER Policy Directive No. 9483.00-1

                                         7-1

            7.0  SECONDARY CONTAINMENT SYSTEMS AND RELEASE DETECTION
    Under the  Sec.  264.193(a)  regulations,  all  hazardous  waste  tank systems,
except  those  specifically  exempted  in  Sec.   264.190(a)  and  (b),  will  be
required  to be  either  installed  or retrofitted  with  secondary  containment,
including a leak-detection capability,  within a specific  period of time.   Tank
systems  with  newly  listed  hazardous  wastes  are   also subject  to  the  Sec.
264.193 secondary containment system requirements.   The  only  exceptions  to the
secondary   containment   requirements  will   be  granted  to  those  owners  or
operators who  demonstrate  successfully  that  their  tank  systems  qualify  for  a
variance from  the requirements  under Sec.  264.193(g)  (see  Section 8.0 of this
document for further information on variances).

    EPA  has   determined  that   secondary   containment  with   interstititial
monitoring  is   the  only  proven  technique   for  guarding  against   releases  to
ground and"  surface  waters.   The primary advantage  of  secondary  containment is
that  is  allows for detection  of  leaks  from the-primary or  inner  tank  while
providing a secondary  barrier  that  contains  releases  before  they  enter  the
environment.   Secondary  containment  also   provides  protection   from  spills
caused  by   operational   errors,   such  as   overfilling.    All    waste   and
precipitation  collected  by  the  secondary  containment system  must be promptly
removed in accordance  with all  local  and federal  regulations.

    The types  of  tank  secondary containment  systems that are  acceptable  under
Sec.  264.193(d)  are liners  (external  to tanks), vaults,  double-walled  tanks,
concrete bases  with diking,  and equivalent  systems as  approved  by  a Regional
Administrator  of  the  Environmental  Protection  Agency  (EPA).   Liners  cover the
edges of a  tank excavation  to  prevent  migration  of any  released  substances  to
the  environment.   They are  generally  constructed  of  low permeability natural
material  (such   as  clay)   or  of  synthetic  membrane   (such   as  polyvinyl
chloride).    Vaults,  generally  constructed   of   concrete  and  lined  with  a
nonporous coating (required  under  Sec.  264.193(e)<2)(iv)),   act  as  chambers
that  temporarily  contain any released materials.  Vaults are  usually designed
to allow inspection of  the  enclosed  tank for  leaks.   Double-walled  tanks  hold

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                                             OSHER Policy Directive No. 9483.00-1


                                         7-2


 leakage  in  the  interstitial space between the inner and  outer  tank walls, thus

 preventing  releases  to the environment.


     Information   pertaining   to  the   plans  and   descriptions  of  secondary

 containment  systems  must be  included  in Part 8  of the  permit  application,  as

 specified   in   Sec.  270.16(g)—"Detailed  plans  and  description  of  how  the

 secondary  containment  system for  each  tank  system  1s  or  will  be  designed,

 constructed,  and operated to  meet  the  requirements  of  Sees.  264.193(a), (b),

 (c),  (d),  (e),  and  (f)."   Detailed  guidance   is  provided  in  the  following

 sections.


                7.1   SECONDARY CONTAINMENT IMPLEMENTATION SCHEDULE


     Citation


     Sec.  2'64.193(a)  defines  the federally mandated implementation  schedule for

 installation  of secondary containment  for  new   and  existing 'tanks, as  of the

.effective date  of  the amended Regulations (Jan.   12,1987):*
          For  all  new tank systems or  components, prior  to  their being put
          into  service;
     (2)   For   all   existing   tank  systems  used  to  store  or  treat  EPA
          Hazardous  Waste  Nos.   F020,  F02J.F022,  F023,   F026,  and  F027,
          within  two years  after  January  12, 1987.
     (3)   For  those  existing  tank  systems  of  known  and  documented  age,
          within  two years after January  12,  1987  or  when  the  tank system
          has reached 15  years of age,  whichever  comes later; and
     (4)   For  those  existing  tank  systems  for  which the  age  cannot  be
          documented,  within  eight  years of January  12,   1987;  but  if the
          age  of  the  facility   is   greater  than  seven   years, secondary
          containment must  be  provided  by  the  time  the facility reaches 15
          years  of age,  or within two  years by  January 12,  1987, whichever
          comes  later; and
     (5)   For   tank   systems  that  store   or  treat  materials  that  become
          hazardous  wastes  subsequent to  January  12,  1987, within the time
          intervals  required   in  paragraphs  (a)(l)  through  (a)(4)  of this
          section,  except that the date  that  material  becomes  a hazardous
          waste  must be  used  In  place of  January  12, 1987).
    Applicable  State regulations should be consulted  to determine  if  a State
    mandated  schedule  is  in  effect.

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                                             OSWER Policy Directive  No.  9483.00-1

                                         7-3

    Guidance

    The  Sec.   264.193(a)  regulations  require  that  tank   systems  posing  the
greatest risks receive the  most  immediate  attention and that new tank  systems
install  secondary  containment  prior to  being  placed  in use, since it  is  most
feasible to install containment at that time.  Tank systems  containing  certain
listed  dioxin  wastes  (Sec.  264.193(a)(2)) and  those  that are 15 years  of age
are considered to be of greatest  risk to human health and  the  environment.Such
tank  systems  have  a  maximum  of two  years  from  the effective  date  of these
regulations to install  secondary  containment.

    Documentation of the  age  of  a  tank system  may  be  provided  by a  bill  of
sale,  dated engineering drawings  of a facility, or any other  written proof of
tank system installation.   Even  if  a tank system  has  not  contained  hazardous
waste   for  15  years, the  tank  system may have deteriorated  during  its  service
lifetime.  Thus,  the documented age  desired  by  the EPA  is the actual  age  of a
tank system, not  the period  the system held hazardous  waste.

               7.2  PROPERTIES OF A SECONDARY  CONTAINMENT  SYSTEM

    Citation

    As  stated  in  Sec.  264.193(b)  of the Part B permit application regulations,
a tank system's secondary containment must  be:

    (1)  Designed,  installed,  and  operated  to  prevent  any migration  of
         wastes  or  accumulated  liquid out  of  the  system  to  the  soil,
         ground water,  or surface water at  any time during  the use  of the
         tank system;  and
    (2)  Capable   of detecting and   collecting   releases  and  accumulated
         liquids  until  the collected material is removed.

    Guidance

    The  requirements for  tank  system secondary containment are  meant  to ensure
that  no waste is  released  to the  surrounding  environment.   Sec. 264.193(b)
lists   the  necessary characteristic  design  properties  of an effective  secondary

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                                                   r^jt , i.j uiiduCive rto.

                                         7-4

containment system, and  Sec.  264.193(c)  elaborates upon them  (see  Sec.  7.3 of
this manual, "Design Parameters").   Section 264.193(d)   lists devices  that  will
meet   the   criteria  for  effective  secondary   containment.    Finally,   Sec.
264.193(e)  provides  further  requirements  for  these   systems  (see  Sections
7.5-7.7  of  this   document,  "Liner  Requirements,"  "Vault  Requirements,"  and
"Double-Walled  Tank  Requirements").   If  a containment  system complies  fully
with  Sec.  264.193(c-e),  the  requirements  of Sec.  264.193(b) will  have  been
met.

    Section 264.193(f) states  that the requirements of  Sec. 264.193(b)  and (c)
must be  met  for all ancillary equipment  (see  manual Sec.  7.8), except for the
following equipment,  provided that  the  equipment  is visually  inspected  daily
for leaks:

    o    piping that is completely aboveground;

    o    welded flanges, welded  joints, and welded connections;
                                              •
    o    sealless or magnetic-coupling pumps; and

    o    pressurized  aboveground  piping,  with  automatic shut-off devices
         (such  as  flow-check  valves,  flow-metering   shutdown  devices,
         etc.).

                             7.3  DESIGN PARAMETERS

    Citation

    The  minimum design requirements for  all  secondary  containment systems are
stated in Sec.  264.193(c).  To summarize,  the secondary containment system:

    (1)  must  be  lined  and/or  constructed of  materials compatible  with
         the  contained  waste  and  designed to withstand pressure gradients
         (including   static   head   and   external   hydrological   forces),
         physical  contact with  any  released waste, climatic  conditions,
         and  daily  operational   stresses (Including   those  from  nearby
         vehicular  traffic).

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                                             OSHER Policy Directive  No.  9433.00-1

                                         7-5

    (2)  must  be  placed  on  a  foundation   which  can  support  it,  can
         withstand  any  foreseeable   pressure   gradients,   and   prevent
         failure due to settlement,  compression,  or  uplift.
    (3)  must have  a  leak-detection  system that  will  detect  the  presence
         of a release  within  24 hours, unless it can  be demonstrated that
         existing  detection   technologies  or  site  conditions  will  not
         permit detection within 24  hours.
    (4)  must be  sloped  or operated  to drain to remove  any accumulated
         liquids resulting from  spills,  leaks, or precipitation within 24
         hours unless  it can  be demonstrated that removal of the  liquids
         cannot be accomplished within 24 hours.

    Guidance

    The relevant  design  parameters   for  a  tank  system's  secondary  containment
system are  described  in Sec.  264.193(c).    According  to  Sec.  264.196(a)  and
(b),  if  contaminated  liquids from  a  tank  release  are  found in  a secondary
containment system, action must  be  taken immediately to minimize the  released
quantity by  stopping  the  flow of waste to  the  tank  and, if  necessary  due to
potentiaj_ exposure,  emptying   the  tank's  contents  into  a secure  containment
device (another tank  or  container).   The specific Sec.  264.193(c)  requirements
are discussed in the following subsections.
                                             •
                                                               t
    A)   Compatibility and  Strength

    According to Sec.  264.193(c)(1),  a secondary   containment  liner  or  material
    of construction  must be  compatible  with its contained waste(s)  to  ensure
    the containment's  integrity,  thus preventing releases to  the  surrounding
    environment.     Depending   on  a  waste's   chemical   characteristics,   a
    compatible liner  must  be  selected.  As  described  in  Sees.  264.191(b)(2)
    and 264.192(a)(2),  the owner or  operator of a  tank system must perform a
    detailed chemical  and physical  analysis of contained waste(s).   This  data,
    along with information from  the  Chemical Engineers'  Handbook,  the  National
    Association  of   Corrosion   Engineers   (NACE),   tank,   liner,    and   resin
    manufacturers, on-site facility  tests, and any  other relevant  sources,  may
    be used  to  convince  the  EPA of  the  compatibility of  a  stored   waste  with
    its  secondary  containment.   The  EPA  document  entitled  "Lining of  Waste
    Impoundment  and  Disposal   Facilities"   (U.S.   Department  of   Commerce,
    National   Technical   Information   Service,  Publication  PB81-166365,   1980)

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                                         OSHEH Policy  Directive  No.  9483.00-1

                                    7-6

provides extensive  information  and references on establishing  waste-liner
compatibi1ity.

It  is  necessary  to consider  all  waste  constituents when  assessing  the
compatibility of a  secondary  containment  liner or material of  construction
in a  given  storage  or  treatment  application.  An  owner or  operator  is
advised not to  place  incompatible  wastes  within a single,  common  secondary
containment  area without  some  sort of partition (e.g., berms)  between  the
ncompatible   wastes.   Note that  Sec.  264.193(e)(2)(iv) requires  secondary
containment   concrete  vaults   to  be   provided  with   a   coating   that   is
compatible  with any stored waste.

Secondary containment  strength,  generally a  direct function of  thickness
for a  given  material,  must.be adequate to prevent  failure  and to,  ensure
continued and proper operation of  the leak-detection  device.   The stresses
referred to in Sec. 264.193(c)(l) may  be caused by:

     o    pressure gradients, both  vertical  (from   the weight  of  the  tank
          and its  contents and any backfill)  and horizontal  (from external
          hydro'tgic, i.e., ground  water or saturated  soil,  pressure);

     o    waste contact, if the primary containment  fails;

     o    adverse  climatic  conditions,  such  that  the physical  properties
          of a secondary containment system are altered;  and

     o    daily  operational   activities,  including  nearby   and  overhead
          vehicular traffic.

Static  vertical  pressure gradients  on  a  tank's   secondary  containment
system  are  generally not  a  cause  for concern if installation  of the  tank
and  its  containment are  performed properly.    The  static  pressures  below
and  above  a containment  should  be in relative  balance  if  the  containment
is adequately  protected from  punctures and  from uneven  load  distribution
(e.g.,  an  underground  tank  seated   Improperly on  backfill).   Adequate

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                                          OSWER  Policy  Directive  No.  9483.00-1

                                     7-7

 separation-  of  an   iaground   or   underground   tank  from   its   secondary
 containment  using  homogeneous, rounded,  porous,   well-compacted  backfill
 material   will   protect   the   containment  (liner  or  vault)  from  damage.
 Aboveground  tank  secondary containment  must  be  kept  free of  debris  to
 protect the  integrity of the  containment  material.

 Horizontal  pressure gradients  generally  are  only  a  concern  for  an  inground
 or an  underground  tank located  in  a   region  with  a  high ground-water
 table.   If  the  ground  water  table  is higher  than  the  lowest  point  of  a
 secondary   containment  system,  the  resulting  inward  pressure   may  be
 significant.   If  a  liner  is  to  be  installed  in  an area  of high  ground
 water,  the site must  be dewatered  until  the liner, the  tank,  the  piping,
 and  the  backfill   have  been   installed  (See  Section  6.2  of this  manual).
 The  backfill,  if properly installed, will  more  than  offset  the  pressure  or
 buoyant force   exerted   by  the  ground   water  once  dewatering  has  been
 terminated.   Liners and  coatings on  concrete  vaults  should  be thick enough
 so that  they remain  impermeable  in  high ground  water conditions.   Test
 results on  the   impermeability of  a  material   to  water,  over   time,   are
 useful   to  predict   long-term  integrity  for  a  secondary   containment
 material.

 A  tank's  secondary containment  must be  compatible  with  a stored waste and
 structurally secure enough to  retain  any released waste material  until  it
 can  be  removed.   Generally, the additional  pressure of released wastes  on
 the  containment  system  will  have only  a  minimal  impact on the  secondary
 containment's  support capabilities.

 Adverse climatic   conditions   can  change  the   physical   properties of  a
'secondary  containment  system,  potentially jeopardizing  its strength  and
 Integrity.   Test  results  on   the ability of  a  containment material  to
 withstand   extremes   in   temperature,   excessive  moisture,   ultraviolet
 radiation,  high  winds,  etc.,   are  useful  to predict  the  ability  of  the
 material  to  remain  secure.

 The  stresses of daily operation,  such as from vehicular  traffic,  will not
 have  significantly -adverse effects  on  a secondary containment  system  if

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                                         OSHER Policy Directive No.  9433.00-1

                                     7-8

the  tank  system  is  Installed  and  operated   properly.    Site-specific
conditions must  be  considered  when  determining if a  secondary containment
system has sufficient  strength  to maintain its  integrity  in  the  presence
of  any  operational  stresses.   Such  conditions may  include  traffic,  heavy
equipment, winds,  precipitation,  frost,  and  ground-water   level  (buoyant
forces for underground and inground  tanks).

B)   Foundation Integrity

Sec. 264.193(c)(2) requires  secondary  containment to be  properly supported
in  order  to  prevent  structural  failure  from  settlement,  compression,  or
uplift,   including  the residual effects  of installation.  As  discussed  in
document Section 7.3 (A), vertical pressure gradients  should be  relatively
In  balance  if  the  backfill  surrounding  the  containment 1s  homogeneous,
rounded,  and   porous.    Compressive  stresses  should  not   be  harmful   to
secondary containment  material  if the  backfill does  not contain  debris  or
significant liquid from  precipitation.  The  backfill  below  a containment
should be compacted  prior to the  installation of the secondary containment
system,  and it  should  be particularly well-compacted  for concrete  vaults
to prevent cracking caused by settlement.

In  an area  with a high  ground-water  table,  a coated concrete vault  or  an
anchored  double-walled   tank   is  the   preferred   method   of   secondary
containment.   A  vault  or an anchored double-walled tank is  less  likely  to
fail from uplift under this environmental condition.   The water  table  at  a
tank  facility   may  be   either  consistently or  seasonally  high,  and  the
choke of a secondary  containment system  and  the Installation  procedures
should be based on the potential for  a high water table to exist.

C)   Leak-Detection Capability

The  leak-detection  portion  of a secondary  containment  system,  required
under  Sec.  264.193(b)<2)   and   described   in   more  detail   in   Sec.
264.193(c)(3),   is  one of  the  most  important  components  of  a containment
system.     Early-warning    leak-detection   systems    provide   continuous
surveillance  for the presence of a leak or spill.

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                                         OSHER Policy Directive No.  9483.00-1

                                     7-9

The  types  of  early-warning  monitoring  systems  most  widely  used  for
underground and inground tank systems are:

     o    Systems that  monitor the  storage  tank excavation.   These  types
          of systems  include  wire grids,  observation  wells,  and  U-tubes.
          The types  of leak sensors used  in these systems include:

               thermal-conductivity sensors;
               electrical-resistivity sensors;
               vapor detectors.

     o    Interstitial monitoring,  e.g.,  monitoring for  leaks  between the
          walls of a dual  - walled tank.

     o    Daily  Visual  Monitoring.   This  method  can  be  effective  for
          aboveground or  vaulted  tanks,  and  for other  tanks  where access
          to  potentially   leaking   parts   is  available".   Daily   visual
          monitoring can also  be  effective for the inspection  of 'ancillary
          equipment.

     o    Ancillary   equipment  leak  detection.    In  addition  to  daily,
          visual   inspections  for   aboveground   tank   systems,   ancillary
          equipment   of  underground,  inground,  onground,  or   aboveground
          systems may  be  monitored  by  the   use  of the  sensors mentioned
          above with  the  sensing  elements  being placed  in  the  secondary
          containment of the ancillary equipment.

Electrical-resistivity  and  thermal-conductivity  sensors and  interstitial
monitoring  are  also  used  with   aboveground   and  onground  tank  systems.
These leak-detection systems are  described  below.

     1)    TANK EXCAVATION  MONITORING SYSTEMS

     There  are  several  types  of  leak-monitoring systems  that  may  be
     employed using  specific  sensors  (described  in the  following  section,
     "LEAK SENSORS")  to detect leaks in  a  tank storage or treatment area.

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                                                 U i I (Si. I I VB flO.
                               7-10
The  leak-monitoring   systems  are  discussed  below,   and  include  the
fol lowing:

     o  Wire grids
     o  Observation wel Is
     o  U-tubes

Table 7-1 shows the  applicability  of  the various leak sensors  to  the
different tank excavation monitoring systems.

Hire Grids.    This type of leak-monitoring system employs  electrical
resistivity  sensors  in   a  wire  grid  located  within  the  containment
region.   The   wire   grid  is   connected  to   a  minicomputer  that
continuously monitors the  electrical  properties of each  wire  in  the
grid.   If a leak  occurs,  the minicomputer can  determine  which wires
in the  grid have  had  their  electrical  properties   altered,  thereby'
identifying  the location  and  extent of a  leak.   In 'the  presence of a
leak, the insulation  around a grid wire  or  the  wire itself  will  be
dissolved,  registering  a cha'nge  in resistivity.  A  drawback  of this
type of system is  that  it  is  susceptible to  failure  caused  by damage
from a spill.

Observation  Nells.   Observation   wells  are  used  in  areas of  high
soil-water  content.   The  wells  typically  consist   of  a  four-inch
diameter  (Schedule 40)  polyvinyl chloride  (PVC)  or slotted  stainless
steel  pipe   driven  into a  tank  excavation  within   the  secondary-
containment  system  (see  Figure  7-1).   Wells  typically  have  a  well
screen  slot size  of 0.02  inches, are extended  to  grade,  and  are
covered  with a waterproof  cap.   If slots are  large  enough  to permit
backfill  to  enter  the well casing, the  casing  should  be wrapped  in
filter fabric before backfilling.

U-tubes.   A  U-tube  typically   consists  of  a  four-inch  diameter
(Schedule 40)  PVC pipe,  installed within  the  secondary  containment
system  as  shown   in  Figure  7-2.   Another  design  configuration  has

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                                6-25
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                                            OSHER Policy Directive No.  9483.00-1

                                        6-27

    the information provided  under  paragraph  (a) (3) of this  section  or other
    corrosion  protection   if  the   Regional   Administrator  believes   other
    corrosion  protection  is  necessary to  ensure  the  integrity  of  the  tank
    system during  use of the tank, system.   The installation of a  corrosion
    protection  system  that   is  field  fabricated  must be  supervised  by  an
    independent corrosion expert to ensure proper installation.

    Guidance

    Using the information obtained for the  requirements of  Sec.  264.192(2)(3),
an  independent   corrosion  expert  (defined  In  Section  5.1)  will  be able  to
determine  corrosion  protection   needs  of  a  tank  system  for   its  intended
lifetime.   A  corrosion expert  must oversee the  installation of  any corrosion
protection  devices,   particularly   cathodic   protection,   that   are   field
fabricated for a new tank system.

    Information  on  cathodlc-protection   system   construction,   inspection,
handling,  electrical  isolation, and installation details can  be  found  in  the
NationalAssociation   of  Corrosion  Engineers   (NACE)   Standards   RP-02-85,
"Recommended  Practice—Control  of  External  'Corrosion  on  Metallic  Buried,
Partially • Buried,   or  Submerged   Liquid   Storage  Systems"  (1985);  RP-01-69,
"Recommended  Practice—Control  of   External   Corrosion   on  Underground   or
Submerged  Metallic  Piping   Systems"   NACE  (1983),  and  Petroleum  Equipment
Institute   (PEI)    standard    PEI/RP   100-86,   "Recommended   Practices   for
Installation  of  Underground  Liquid  Storage  Systems"  (1986).    (See  document
Section   5.4   for   additional    information   on   cathodic-protection   system
installation.)

                 6.6  CERTIFICATIONS OF DESIGN AND INSTALLATION

    Citation

    Following  installation,  Sec.  264.192(g) requires the owner or  operator  of
a new tank system to:

    ...obtain and  keep on  file  at the  facility written  statements  by  those
    "persons" required  to certify the design of  the  tank  system  and supervise
    the installation of the  tank system in accordance with  the  requirements  of
    paragraphs  (b)  through  (f)   of this  section,   that  attest  that  the  tank
    system was properly  designed  and  installed  and  that repairs, pursuant  to
    paragraphs  (b)  and  (d)   of  this   section,  were performed.   These written

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                                            OSWER Policy  Directive  No.  9483.00-1


                                        6-28


    statements must  also  include  the  certification statement  as  required  in
    §270.IKd) of this Chapter.


    Guidance


    The  professional   engineer   who  certifies  a  tank   system's   structural

integrity,   the  installation  inspector,  the  tightness   tester,  the  corrosion

expert,  and  anyone  else   who  has  supervised  a portion  of  the  design  and

installation of  a new tank  system  or  component must  document that  the  system

is  In  accordance  with  the  requirements   of  Sec.  264.192(a-f).    Materials

accompanying   and   supporting  these   statements   might  include   "as-built"

installation drawings and  photographs  of tank and piping  components.


    A sample statement of  the form  required by"  Sec. 264.192(g),  including  the
Section 270.11(d) truthfulness certification, follows:


          I,   [Name],  have  supervised  a  portion  of  the  design  or
    insolation   of   a  new  tank  system  or  component   located   at
    [Address], and owned/operated  by  CName(s)].  My  duties  were:
    [e.g.,  preinstallation inspection, testing  for  tightness,  etc.],
    for  the  following tank  system  components  [e.g..  the  tank,  vent
    piping,  etc.],  as  required  by the   Resource  Conservation  and
    Recovery  Act  (RCRA)   regulation(s),   namely,  40   CFR   264.192
    [Applicable Paragraphs (i.e.,  a-f)].

         I  certify  under penalty  of  law  that I  have  personally
    examined and  am  familiar with the information  submitted  in  this
    document and  all  attachments and  that,  based  on  my  inquiry  of
    those  -individuals  immediately  responsible  for  obtaining   the
    information,  I believe that  the  information is true,  accurate,
    and  complete.   I  am  aware  that there  are  significant penalties
    for  submitting false   information,  including the  possibility  of
    fine and imprisonment.
                                     Signature
                                     Title
                                     Registration No.,  if applicable


                                     Address

    The certification  statements  must  be kept on file  indefinitely at the tank
facility,  as specified in Sec.  264.192(g).

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                                            OSWER Policy Directive No.  9483.00-1

                                        6-29

                  6.7  DESCRIPTION OF TAN< SYSTEM INSTALLATION

    Citation

    For  the  Part B  application  the  owner or operator must  provide  a  detailed
description of  how  a  new tank  system  will  be  installed,  in accordance  with
Section 270.16(f):

    Sec.  270.16(f)   for  new tank  systems,  a detailed  description of  how  the
    tank  system(s) will  be  installed in  compliance with  Sec.  264.192(b),  (c),
    (d), and (e);
    Guidance

    Section 270.16(f)  requires  that owners  or  operators  provide  a  detailed
description of the tank  system installation with respect to  the  tank  handling
and  installation  procedures,   the  type  and   Installation  of  backfill,  the
tightnesT testing results  and  methodology, and  the installation  of ancillary
equipment.  This  description  must  be  sufficiently detailed  for  the EPA  to
determine  if  the   tank  and  i'ts  ancillary  equipment,  as  installed,   have
sufficient  integrity to  prevent  releases of waste  to the  environment  during
use.    The  description  should  describe  handling  and  lifting  methods   used
on-site  and  precautions  taken  to avoid  weld  breaks,  punctures,  scrapes,  of
protective  coatings,  cracks,  corrosion,  and   other   structural   damage.    The
description should  also  include  precautions  taken to avoid  future  damage  due
to  settling,   high  water  tables,  frost  heave,  vibration,  expansion,   and
contraction.   For the  tightness   testing,  the  description  should  include  the
methodology, the results, conclusions, and any  recommendations made  or actions
taken as a result of the testing.

                          6.8  SUMMARY OF MAJOR POINTS

    The  following  summarizes  the  information  covered  in   this  section  and
should be used to assure the completeness of a Part B permit  application:

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                                        UiHtK policy Directive No.  9483.00-1

                                    6-30

o    Is  the  installation  inspector or  registered  engineer  qualified  to
     inspect a  new tank  system  or component  prior to  installation?   Can
     this  individual  discriminate   between  reparable   and   irreparable
     damages and defects?  Can he/she  assess the adequacy of a repair?

o    Has  he/she  inspected   the  tank   system during  Installation  for  the
     presence of at least the following:

     —  Weld breaks;
     —  Punctures;
     —  Scrapes of protective coatings;
     --  Cracks;
     —  Corrosion; and
     —  Other structural damage or inadequate construction/installation.

     Have all  such problems  been remedied before  the  system  was placed in
     use?

o    Is   the   backfill   noncorrosive,   porous,   homogeneous?   Are   the
     dimensions  of the  tank excavation adequate?   Has the  backfill  been
     placed and compacted carefully around the tank?

o    Does the tank pass a test for tightness?  Does  the  piping system pass
     an analogous  test?

o    Is  the  piping  system  adequately  supported  and  protected  against
     damage from external and internal loads?

o    Has  a  corrosion  expert  supervised  the  installation of  any  field-
     fabricated   corrosion   protection,   particularly  cathodic-protection
     devices?

o    Have  statements  been written by the appropriate  personnel  to certify
     that  the  tank  system  is properly designed  and installed?   Are these
     statements on file at the facility?

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                                            OSHER Policy Directive  No.  9483.00-1


                                        6-31


         Has  a  detailed  description  of  the   tank  system  installation  and

         tightness testing been provided?
In  addition,  see  Appendix  A,  "Completeness  Checklist,"  to  verify  compliance
with the requirements of this section.

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                                             OSWER Policy Directive No.  9483.00-1

                                         7-1

            7.0  SECONDARY CONTAINMENT SYSTEMS AND RELEASE DETECTION
    Under  the  Sec.  264.193(a)  regulations,  all  hazardous  waste  tank systems,
except  those  specifically  exempted  in  Sec.   264.190(a)  and  (b),  will  be
required  to be  either  installed  or retrofitted  with  secondary  containment,
including a leak-detection capability,  within a specific  period of  time.   Tank
systems  with  newly   listed  hazardous  wastes  are   also subject  to  the  Sec.
264.193 secondary containment system requirements.   The  only exceptions  to the
secondary   containment   requirements  will   be  granted  to  those  owners  or
operators who  demonstrate successfully  that  their  tank  systems  qualify  for  a
variance from  the requirements  under Sec.  264.193(g)  (see  Section  8.0 of this
document for further  information on variances).

    EPA  has   determined  that   secondary   containment  with   interstititial
monitoring  is   the  only  proven  technique   for  guarding  against  releases  to
ground and  surface waters.   The primary advantage of  secondary  containment is
that  is  allows for detection  of  leaks  from the primary or  inner  tank  while
providing  a  secondary barrier  that  contains  releases   before  they   enter  the
environment.   Secondary  containment  also   provides  protection  from  spills
caused  by   operational   errors,   such  as   overfilling.    All    waste   and
precipitation  collected  by  the  secondary  containment  system  must  be promptly
removed in accordance  with all  local  and federal  regulations.

    The types  of  tank  secondary containment  systems that are  acceptable  under
Sec.  264.193(d)  are  liners  (external  to tanks), vaults,  double-walled  tanks,
concrete bases with diking,  and equivalent  systems  as  approved  by  a Regional
Administrator  of  the  Environmental  Protection  Agency  (EPA).   Liners cover the
edges of a  tank excavation  to  prevent  migration  of any  released  substances  to
the  environment.  They are  generally  constructed  of  low permeability natural
material   (such  as   clay)   or   of  synthetic  membrane  (such  as   polyvinyl
chloride).   Vaults,   generally  constructed   of   concrete  and  lined  with  a
nonporous  coating  (required  under  Sec.  264.193(e)(2)(iv»,   act  as  chambers
that  temporarily  contain  any released  materials.  Vaults are  usually designed
to allow inspection of  the  enclosed  tank for  leaks.   Double-walled  tanks  hold

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                                             OSHER Policy Directive  No.  9483.00-


                                        7-2


leakage in the interstitial  space between  the inner and outer tank  walls,  thus

preventing releases to the environment.


    Information  pertaining   to   the  plans  and  descriptions  of  secondary

containment systems must  be  included in Part B of  the  permit application,  as

specified  in  Sec.  270.16(g)--"Detailed   plans   and  description  of  how  the

secondary containment  system for  each  tank  system is  or  will  be  designed,

constructed,   and  operated to meet  the  requirements of  Sees. 264.193(a),  (b),
(c),  (d),  (e),  and  (f)."   Detailed guidance  is  provided  in  the  following

sections.


               7.1   SECONDARY CONTAINMENT  IMPLEMENTATION SCHEDULE


    Citation


    Sec.  264.193
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                                             OSWER Policy Directive No.  9483.00-1

                                         7-3

    Guidance

    The  Sec.   264.193(a)  regulations  require  that  tank  systems  posing  the
greatest risks receive the  most  immediate attention and  that  new  tank  -systems
install  secondary  containment prior to  being  placed  in use,  since  it  is  most
feasible to install containment at that time.  Tank systems  containing  certain
listed  dioxin  wastes  (Sec. 264.193(a)(2)) and  those  that are 15  years  of age
are considered to be of greatest risk to human health and  the  environment.Such
tank  systems  have  a  maximum  of two  years  from the effective  date of these
regulations to install secondary containment.

    Documentation of  the  age  of a  tank system  may  be   provided  by a  bill  of
sale,  dated engineering drawings  of a facility, or any  other  written proof of
tank system installation.   Even  if  a tank system  has  not  contained  hazardous
waste   for  15  years,  the  tank  system may have deteriorated  during  its  service
lifetime.  Thus,  the documented age  desired  by  the  EPA  is the actual age  of a
tank system, not  the period the system held hazardous  waste.

               7.2  PROPERTIES OF A SECONDARY  CONTAINMENT SYSTEM

    Citation

    As  stated  in  Sec.  264.193(b)  of the Part B permit application regulations,
a tank system's secondary  containment must be:

    (1)  Designed,  installed,  and  operated  to  prevent  any migration  of
         wastes  or  accumulated  liquid out  of  the  system  to the  soil,
         ground water, or  surface water at any time during  the use  of the
         tank system;  and
    (2)  Capable   of detecting  and   collecting   releases  and  accumulated
         liquids  until the collected material is removed.

    Guidance

    The  requirements  for  tank  system secondary containment are meant to ensure
that  no waste is  released  to  the  surrounding  environment.   Sec.  264.193(b)
lists   the  necessary characteristic  design properties  of an effective secondary

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                                         7-4

containment system, and  Sec.  264.193(c)  elaborates  upon them (see  Sec.  7.3 of
this manual, "Design Parameters").   Section 264.193(d) lists devices  that  will
meet   the   criteria  for  effective  secondary  containment.    Finally,   Sec.
264.193(e)  provides  further  requirements  for  these  systems   (see   Sections
7.5-7.7  of  this   document,  "Liner  Requirements,"   "Vault  Requirements,"  and
"Double-Walled Tank  Requirements").   If  a  containment  system  complies  fully
with  Sec.  264.193(c-e),  the  requirements  of Sec.  264.193(b)  will  have  been
met.

    Section 264.193(f) states  that the requirements  of Sec. 264.193(b)  and (c)
must be  met  for  all ancillary equipment  (see  manual  Sec.  7.8),  except for the
following equipment,  provided that  the   equipment  is visually inspected  daily
for leaks:

    o    piping that is completely aboveground;

    o    welded flanges, welded  joints,  and welded connections;

    o    sealless or magnetic-coupling pumps;  and

    o    pressurized  aboveground  piping, with  automatic  shut-off devices
         (such  as  flow-check  valves,   flow-metering  shutdown   devices,
         etc.).

                             7.3  DESIGN PARAMETERS

    Citation

    The  minimum  design requirements for all  secondary  containment  systems are
stated in Sec. 264.193(c).  To summarize, the secondary containment system:

    (1)  must  be  lined  and/or  constructed  of  materials  compatible  with
         the contained  waste  and  designed to withstand pressure  gradients
         (Including   static   head   and   external   hydrological   forces),
         physical  contact with  any  released  waste,  climatic  conditions,
         and  daily  operational   stresses  (including  those  from  nearby
         vehicular traffic).

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                                             OSHER Policy Directive No.  9483.00-1

                                         7-5

    (2)  must  be  placed  on  a  foundation   which  can  support  it,  can
         withstand  any  foreseeable   pressure   gradients,   and   prevent
         failure due to settlement, compression,  or  uplift.
    (3)  must have  a  leak-detection  system that  will  detect  the  presence
         of a release  within  24 hours, unless it can  be demonstrated that
         existing  detection  technologies  or  site  conditions  will  not
         permit detection within 24 hours.
    (4)  must be  sloped or operated  to drain to remove  any accumulated
         liquids resulting  from  spills,  leaks, or precipitation within 24
         hours unless  it can  be demonstrated that removal of the  liquids
         cannot be accomplished within 24 hours.

    Guidance

    The relevant  design parameters  for  a  tank  system's  secondary containment
system are  described   in Sec.  264.193(c).    According  to  Sec.  264.196(a)  and
(b),  if  contaminated  liquids from  a  tank  release  are  found in  a secondary
containment system, action  must  be taken  immediately to minimize  the  released
quantity by  stopping   the  flow of waste to  the  tank  and, if  necessary  due to
potentiaj_ exposure,  emptying   the  tank's  contents  into  a secure  containment
device (another tank  or container).   The specific Sec.  264.193(c)  requirements
are discussed in the following subsections.

    A)   Compatibility and  Strength

    According to Sec.  264.193(c)(l),  a secondary   containment  liner  or  material
    of construction  must be  compatible  with its contained waste(s)  to  ensure
    the containment's  integrity,  thus preventing releases to  the  surrounding
    environment.     Depending   on  a  waste's   chemical   characteristics,   a
    compatible liner  must  be  selected.   As  described  in  Sees.  264.191 (b)(2)
    and 264.192(a)<2),  the owner or  operator of a  tank system must perform  a
    detailed chemical  and physical analysis of contained waste(s).   This  data,
    along with information  from the  Chemical Engineers'  Handbook,  the National
    Association  of   Corrosion   Engineers  (NACE),   tank,   liner,    and   resin
    manufacturers, on-site  facility  tests, and any  other relevant  sources,  may
    be used  to  convince the EPA of  the  compatibility of  a  stored  waste  with
    its  secondary  containment.   The  EPA  document  entitled  "Lining of  Waste
    Impoundment  and   Disposal   Facilities"   (U.S.   Department  of   Commerce,
    National  Technical  Information   Service,  Publication  PB81-166365,   1980)

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                                         Oi«t/\ ro.icy  Directive  No.  9433.00-1

                                    7-6

provides extensive  information  and references on establishing  waste-liner
compatibility.

It  is  necessary  to consider  all  waste  constituents when  assessing  the
compatibility of a  secondary  containment  liner or material of  construction
in a  given  storage  or  treatment  application.  An  owner or  operator  is
advised not to  place  incompatible  wastes  within  a single,  common  secondary
containment  area without  some  sort  of partition (e.g., berms)  between  the
ncompatible  wastes.   Note that  Sec.  264.193(e)(2)(iv) requires  secondary
containment   concrete  vaults   to  be   provided  with   a   coating   that   is
compatible with any stored waste.

Secondary containment  strength,  generally a  direct function of  thickness
for a  given material,  must be adequate to prevent  failure  and to,  ensure
continued and proper operation  of  the leak-detection  device.   The stresses
referred to in Sec. 264.193(c)(l) may  be caused by:

     o    pressure gradients,  both  vertical  (from   the weight  of  the  tank
          and its  contents and  any backfill)  and horizontal  (from external
          hydro'ogic, i.e., ground  water or saturated  soil,  pressure);

     o    waste contact, if the primary containment  fails;

     o    adverse  climatic  conditions,  such  that  the physical  properties
          of a secondary containment system are altered;  and

     o    daily  operational   activities,  including  nearby  and   overhead
          vehicular traffic.

Static  vertical  pressure gradients  on  a  tank's   secondary  containment
system  are  generally not  a cause  for concern if installation  of the  tank
and  its  containment are  performed properly.   The  static  pressures  below
and  above  a containment  should be in relative  balance  if  the  containment
is adequately protected  from  punctures and from uneven  load  distribution
(e.g.,  an  underground  tank  seated   Improperly on  backfill).   Adequate

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                                         OSWER  Policy Directive  No.  9483.00-1

                                     7-7

 separation   of  an   inground   or   underground   tank  from   its   secondary
 containment  using  homogeneous, rounded,  porous,  well-compacted  backfill
 material   will   protect   the   containment   (liner  or  vault)  from  damage.
 Aboveground  tank  secondary containment  must  be  kept  free of" debris  to
 protect the  integrity of  the containment material.

 Horizontal  pressure gradients   generally are  only  a  concern  for  an inground
 or  an  underground  tank  located  in  a  region  with  a  high ground-water
 table.   If  the  ground water  table  is higher  than  the  lowest  point  of  a
 secondary   containment  system,  the  resulting  inward  pressure   may  be
 significant.   If  a  liner  is   to  be  installed  in  an area  of high  ground
 water,  the site must  be  dewatered  until  the liner, the  tank,  the  piping,
 and  the  backfill   have  been   installed  (See  Section 6.2  of this  manual).
 The  backfill,  if properly installed, will  more  than  offset  the  pressure  or
 buoyant force   exerted   by the  ground   water  once  dewatering  has  been
 terminated.   Liners and  coatings on  concrete  vaults  should  be thick  enough
 so  that  they remain  impermeable  in  high ground  water conditions.'  Test
 results on  the-  impermeability of  a  material   to  water,  over   time,   are
 useful   to   predict  long-term  integrity  for  a  secondary   containment
 material.

 A  tank's  secondary  containment  must be  compatible  with  a stored  waste  and
 structurally secure enough to  retain  any  released waste material  until  it
 can  be  removed.   Generally, the additional  pressure of released  wastes  on
 the  containment  system  will   have only  a  minimal  impact on the  secondary
 containment's  support capabilities.

 Adverse climatic   conditions  can  change   the   physical   properties  of   a
'secondary  containment  system,  potentially  jeopardizing  its strength  and
 integrity.   Test  results  on  the ability of  a  containment material  to
 withstand   extremes   in   temperature,   excessive  moisture,   ultraviolet
 radiation,  high winds,  etc.,   are  useful   to predict  the  ability  of  the
 material to  remain  secure.

 The  stresses of daily operation,  such as  from vehicular  traffic,  will  not
 have  significantly  -adverse effects  on  a  secondary containment  system  if

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                                               Policy Directive No.  948J.OO-1

                                    7-8

the  tank  system  is  Installed "and  operated   properly.    Site-specific
conditions must  be  considered  when determining if a  secondary containment
system has sufficient  strength  to  maintain its  integrity  in  the  presence
of any  operational  stresses.   Such  conditions may  include  traffic,  heavy
equipment, winds,  precipitation,   frost,  and  ground-water   level  (buoyant
forces for underground and inground tanks).

B)   Foundation Integrity

Sec.  264.193(c)(2) requires  secondary  containment to be  properly supported
in order  to  prevent  structural  failure  from  settlement,  compression,  or
uplift,   including  the residual effects  of installation.  As  discussed  in
document Section 7.3 (A), vertical  pressure gradients should  be  relatively
in balance  if  the  backfill  surrounding  the  containment 1s  homogeneous,
rounded,  and   porous.    Compressive  stresses  should  not   be  harmful   to
secondary containment material  If  the  backfill does not contain  debris  or
significant liquid from  precipitation.  The  backfill  below  a containment
should be compacted  prior  to the  installation of the secondary containment
system,  and it  should  be particularly we 11-compacted  for concrete  vaults
to prevent cracking caused by settlement.

In an  area  with a high  ground-water  table,  a coated concrete vault  or  an
anchored  double-walled   tank   is   the   preferred   method   of   secondary
containment.   A  vault  or an anchored  double-walled tank is  less  likely  to
fail  from uplift under this environmental condition.   The water  table  at  a
tank   facility  may  be   either  consistently  or   seasonally  high,  and  the
choice of a secondary containment  system  and the Installation  procedures
should be based on the potential for  a high water table  to  exist.

C)   Leak-Detection Capability

The  leak-detection  portion  of a  secondary  containment system,  required
under   Sec.   264.193(b)(2)   and   described   in   more  detail   in   Sec.
264.193(c)(3),  is  one of  the  most important  components of  a containment
system.     Early-warning    leak-detection    systems   provide   continuous
surveillance  for the presence of a  leak or spill.

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                                         OSWER Policy Directive No.  9483.00-1

                                     7-9

The  types  of  early-warning  moni tormg  systems  most  widely  used  for
underground and inground tank systems are:

     o    Systems that  monitor the  storage  tank excavation.   These  types
          of systems  include  wire grids,  observation  wells,  and  U-tubes.
          The types  of leak sensors  used in these systems include:

               thermal-conductivity  sensors;
               electrical-resistivity sensors;
               vapor detectors.

     o    Interstitial monitoring,  e.g.,  monitoring for  leaks  between  the
          walls of a dual  - walled tank.

     o    Daily  Visual  Monitoring.   This  method  can  be  effective  for
          aboveground or  vaulted  tanks, and  for other  tanks  where access
          to  potentially   leaking   parts   is  available.   Daily   visual
          monitoring  can also  be  effective for the inspection  of ancillary
          equipment.

     o    Ancillary   equipment  leak  detection.    In  addition  to  daily,
          visual   inspections  for   aboveground   tank   systems,  ancillary
          equipment   of  underground,  inground,  onground,  or   aboveground
          systems may be  monitored  by  the   use  of the  sensors  mentioned
          above with  the  sensing elements  being placed  in  the  secondary
          containment of the ancillary equipment.

Electrical-resistivity  and  thermal-conductivity  sensors and  interstitial
monitoring  are  also  used  with  aboveground   and  onground  tank  systems.
These leak-detection systems are described  below.

     1)   TANK EXCAVATION MONITORING SYSTEMS

     There  are  several  types  of  leak-monitoring systems  that  may  be
     employed using  specific  sensors  (described  in the  following  section,
     "LEAK SENSORS")  to detect leaks in a  tank storage or treatment area.

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                                                            no.
                                7-10

 The   leak-monitoring  systems  are  discussed  below,  and  include the
 fol lowi ng:

      o  Wire  grids
      o  Observation wells
      o  U-tubes

 Table 7-1  shows  the applicability of  the  various  leak sensors to the
 different  tank excavation  monitoring  systems.

 Wire  Grids.   This type  of leak-monitoring system employs electrical
 resistivity sensors  in  a  wire grid  located  within  the  containment
 region.    The   wire   grid  is   connected   to  a  minicomputer   that
 continuously  monitors the electrical  properties  of each  wire in the
 grid.  If  a  leak occurs,  the  minicomputer can determine  which  wires
 in the  grid  have  had  their  electrical  properties  altered,  thereby'
«•»
 identifying the  location  and extent  of  a leak.  In the  presence of  a
 leak, the  insulation around a  grid wire  or  the wire  itself will be
 dissolved,  registering a  change in  resistivity.   A drawback of this
 type  of system  is that it  is  susceptible  to  failure caused  by  damage
 from  a spill.

 Observation  Wells.    Observation  wells  are  used  in areas  of  high
 soil-water  content.   The  wells  typically consist   of   a  four-inch
 diameter (Schedule 40)  polyvinyl  chloride (PVC) or slotted  stainless
 steel  pipe  driven  into  a  tank  excavation   within   the  secondary-
 containment  system  (see  Figure  7-1).   Wells  typically  have a  well
 screen  slot  size of  0.02  Inches,  are  extended  to  grade,  and are
 covered with a  waterproof cap.  If  slots  are large enough  to  permit
 backfill  to enter  the  well casing,  the  casing  should  be wrapped  in
 filter fabric before  backfilling.

 U-tubes.    A  U-tube  typically  consists  of  a  four-inch   diameter
 (Schedule  40) PVC  pipe,   installed  within the  secondary  containment
 system  as  shown  In  Figure  7-2.   Another design  configuration has

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                                    OSWER Policy Directive No.  9483.00-1
                               7-11
                           TABLE  7-1
            APPLICABILITY OF TYPES OF LEAK SENSORS
Sensor Type
Surveillance Method
Wire
Grids
Thermal Conductivity
Electrical Resistivity X
Vapor Detectors
Sampl i ng
Observation
Wells
X
X
X
X

U-tubes
X
X
X
X
Source:   New  York   State  Department  of  Environmental   Conservation,
         "Technology   for    the   Storage   of   Hazardous   Liquids—A
         State-of-the-Art Review," (January 1983), p.  96.

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                                    OSWER Policy Directive No.  9483.00-1

                               7-12

multiple U-tubes,  installed in multiple  pipe  runs  under  a  tank  to
maximize detection  potential.   The  tank  excavation  bottom should  be
sloped a minimum  of  1/4-inch  vertical  per foot  horizontal  toward  the
U-tube  to  permit  collection of  any leaked material.   The  horizontal
segment  of  each   pipe  is  half-slotted  (typical   slot  size,   0.06
inches), wrapped  with  a mesh  cloth  to prevent  backfill  infiltration,
and  sloped toward  a  sump,  with   a  slope of  approximately  1/4-inch
vertical per  foot horizontal.   At the higher  end  of  the  horizontal
pipes, there  is a 90 degree sweep to vertical  pipes  that extend  to
grade.   At the  lower   end  of  each  horizontal   pipe,  there is  a  tee
connection with another vertical  pipe,  which   is  extended  to grade  and
to two  feet  below the  tee  to act  as a collection sump.  All  vertical
pipe sections are unperforated, and  the  bottom of the  sump is  sealed
to be  leakproof.   The  openings  at grade are  provided  with  watertight
caps  that  can  be sealed.   It is  imperative  that  all  openings  be
secured  to prevent water  or  runoff from entering them.   U-tubes  can
be  designed   to  allow   pressurized  flow  to   force  collected   liquids
out.

The U-tube is  a  relatively new design which  has not been extensively
tested  in  the field.   When installed with  an   underlying  impervious
liner, a U-tube will  collect  all   liquids moving  downward through  the
soil  in  the   vicinity  of  a tank,  including  rainwater.   This  design
provides  positive assurance of  collecting leakage  from a tank,  but
presents a problem with  removal of  rainwater which  can  flood  out  the
leak-detection/collection  system.    A  waterproof  cap   will  eliminate
this problem.

2)   LEAK SENSORS

A  tank  excavation monitoring  system, described above,  is  designed  to
detect  a  spill  or  leak before contamination spreads   beyond   a  lined
tank excavation or  a vault.  The   leak- or spill-sensing devices that
may  be used  in   tank  excavation   monitoring  systems  include  thermal
conductivity  sensors,   electrical   resistivity  sensors,  and  vapor

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                                    OSWER Policy Directive  No.  9483.00-1

                               7-15

detectors.    Direct  sampling  can  also  be  used  in   the   case   of
observation wells  and  U-tubes  to pinpoint the occurrence  and source
of a  leak.   (See  Table  7-2 for a  comparison  of  various  leak-sensing
techniques.)   The  following   subsections  describe  the  various  leak
sensors.

Thermal-Conductivity Sensors.   These  sensors  detect  changes  in  the
thermal conductivity of  the  surrounding environment to determine if a
leak  or spill  has  occurred.   They  can  be   used  in   wet  or  dry
applications  and  are  particularly  good  for  detecting  hydrocarbons,
such as alcohols and trichloroethylene.

A  system  using  such a  sensor typically consists  of  an  electronic
control device  that is  connected by  cable to  a thermal-conductivity
probe.  The probe  is  fitted  with  a thermal-conductivity  sensor that
determines   if  a monitored  area is  dry,  wet  with  water,  or  wet with
some other  substance.  The  control  device may  be  located  up  to  1,000
feet from the  probe  and  can  continuously  indicate  the  site condition
using  indicator  lights.   A  nonwater liquid can  be  indicated  by  an
audible al&rm and  recorded  by a chart recorder.  A relay contact that
can  activate  external   alarms,  recovery  pumps,  or  other  automatic
controls can also be provided.

Electrical-Resistivity    Sensors.     One   system    employing   this
leak-detection  device  relies  on  the change in  resistance of a wire
from exposure to  a  stored  material to Indicate  the presence of a leak
or spill.   The  key  to sensors  of this  type  is  the  use of  wires  or
wire coatings that  are  highly susceptible to  degradation when exposed
to a  stored or  treated  waste.  For  example, bare steel  wires may  be
used  in acid storage  areas,  or  bare  aluminum wires  may  be  used  in
caustic storage areas.    If  a  stored liquid is  not  corrosive  to  metal
wire,  the  wire  must be  coated with a degradable material,  such as a
rubber coating in areas storing aromatic  solvents.  The  wires  are,  in
turn,  connected  to an electrical  device  that  passes  current through
them.  Any  degradation of  the  wire  or its coating will result  in a

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                                             OSWER Policy  Directive  No.  9453.00-1
                                        7-16
                                   TABLE 7-2

                  COMPARISON OF VARIOUS LEAK-SENSING TECHNIQUES
  Sensor
      ADD!icatjons
                                   Advantages/Disadvantages
Thermal-
Conductivity
Sensors
Can monitor 1iquids in
soils
                               Primary advantage  is  early
                               detection,  which makes  it
                               possible for leaks  and  spills
                               to  be   corrected  before  large
                               volumes of  material   are  dis-
                               charged.
Electrical-
Resistivity
Sensors
Can monitor 1iquids in
soils
                               Primary advantage  is  the
                               early detection of spills.
                               Once  a  leak  or  spi11  is. de-
                               tected,   the  sensors   must  be
                               replaced.    Can   detect   small
                               and large  leaks.
Vapor
Detectors
Monitors vapor in areas of
highly permeable, dry soil,
such as excavation backfill
or other permeable soils
                               Very useful  for quick detec-
                               tion of highly volatile
                               wastes.
Interstitial
Monitoring in
Double-Walled
Tanks
Measures changes of pressure
or the interstitial presence
of liquids in double-walled
tanks
                               Accurate technique which is
                               applicable to all  double-
                               walled tanks.
SOURCE:  New York  State  Department  of Environmental
         for  the  Storage  of  Hazardous  Liquids—A
         (January 1983), p. 92.
                                     Conservation,  "Technology
                                     State-of-the-Art  Review"

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                                    OSWER Policy Directive No.  9483.00-1

                               7-17

significant  change  in circuit  resistivity,  indicating the  existence
of a product leak or spill.

This type  of electrical-resistivity  sensor  is applicable  for either
wet or  dry  excavation  applications.   Ambient  temperature and  soil
moisture have  minimal  effects  on  sensors of  this  type,  particularly
if  coated   wires  are  used.   The  two  drawbacks  of  this  type  of
leak-detection device are:

o    Once  a  leak  has  been  detected,  the  sensing  wire  must  be
     replaced.

o    The  sensors  cannot  be  used  in  previously  contaminated  soil
     unless  the  contamination  has  been  removed.   Otherwise,  the
     sensors will  deteriorate rapidly and require replacement.

Another  common  electrical-resistivity  system   is   provided   by  an
electrical  probe and  float mechanism suspended in an observation well
on a  flexible cable.   This  system  is  designed only  for hydrocarbon
detection   because    hydrocarbons   are   non-conductive.    Chemical
materials heavier than  water  or polar  materials  that  are  conductive
will  confuse the response.

If the  well  is dry,  the  probe  extends  to the  bottom,  with  the float
resting on the  dry  surface,  and the monitor  station registers  a  dry
environment  (green  light).   Upon   liquid  incursion  of  1/16  inch  or
more,  the float rises  and the monitor  station  reflects the  change  in
condition.    If  the  liquid is  water,  the  electrical  terminal  posts
mounted  in   the  float allow  a  low-voltage  current  to  flow  between
them,  and  the monitor  station  reflects this  condition with a yellow
warning  light.   If, however,  the  liquid  is  a  hydrocarbon,   then  no
current  will  flow.  The monitoring station will  signal  this  condition
with a red  light and a buzzer to alert a tank operator  that  a  release
has occurred.

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                                                 uireccive  MO.
                               7-18
The control units  associated  with  electrical-resistivity sensors  can
be  designed  to  interface  with audible  alarms,  visual   alarms  (e.g.,
indicator lights),  and with control  equipment, such as  pumps,  valves,
and computers.   Occasional  checks  of  such   systems  are required  to
ensure that the power supply and the controls  are in working order.

Vapor   Detectors.   These  devices   can  detect  a  large   number   of
combustible and  non-combustible gases  and  vapors.   They are generally
applicable in  areas  of  permeable  soil or backfill,  where  gases  and
vapors   are    likely   to   migrate   easily.    Vapor   detectors   are
particularly useful  in  instances where a waste  stored  underground  is
highly volatile  and  the  storage excavation is relatively dry (free of
water).

There  are a wide variety of both portable  and  permanent gas-detection
devices available  that  may be operated in  conjunction with audible or
visual alarm systems.

3)   INTERSTITIAL MONITORING (Leak-detection)

An  early-warning  monitoring  technique  used   in  double-walled  tanks
involves monitoring  the  space between  the  inner and  outer  walls  of a
tank,  using either a pressure or  a fluid  sensor.   A pressure  sensor
may be  used  to monitor  a  tank  that  either has a vacuum  in the space
between  the  walls  or  has  the  space  pressurized.   Failure  of  either
the inner or outer wall  is detected by a loss  of vacuum or pressure.

Fluid  sensors  may  be  employed between  the tank walls  to  detect  the
presence of  a  liquid.   The liquid may  enter the  interstitial  space
because of failure of the inner wall  (leaking stored waste) or of the
outer wall (leaking incoming water).

Another method uses the  fluid which is part of the  tank system; i.e.,
a loss of fluid  is  indication of failure of inner or outer wall.

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                                         OSHER Policy Directive  No.  9483.00-1

                                    7-19

0)   Adequate Drainage

Section 264.193(c)(4)  states  that  a secondary  containment  system  must  be
sloped or otherwise  designed  and/or operated so that liquids  will  drain to
the  leak-detection  system  and  can  thus  be  removed.    Typically,  any
released  tank  contents will  drain  along  the  top  of  a  sloped  containment
(liner or vault) or through a porous drainage  layer  within  the  containment
to  reach  a  sump,  trough,  or  similar  device   (see  Figure  7-3).   The
accumulated  liquids  then  can  be withdrawn by  siphoning  or  pumping  from  a
collection area.

An aboveground  containment  system  must be surrounded by impermeable curbs,
gutters,  dikes,  etc.  (usually  constructed  of concrete  or  asphalt)  to
prevent  flow from  leaving the  containment area.   Diked  areas should  be
equipped with manual  release  valves,  siphons,  or  pumps  to permit  removal
of  collected liquids.   Val'ves  should  be  chained  and  locked  in a closed
position when not in use.   Any  wastes  in a tank or  in  ancillary equipment
that drains  to  a secondary containment  system  should  be  removed within 24
hours or as soon as  practicable  to  minimize risks  to  human health  and the'
environment.  If the  collected  material  is hazardous  as defined  by 40 CFR
261 ("Identification and  Listing  of Hazardous Waste"), it must  be  managed
in accordance with  all  applicable  requirements of Parts 262  through 265 of
RCRA ("Standards Applicable to  Generation  of Hazardous  Waste";  "Standards
Applicable  to Transporters  of Hazardous Waste"; "Standards for  Owners and
Operators  of Hazardous  Waste  Treatment";  "Interim  Status  Standards  for
Owners  and  Operators of  Hazardous  Waste  Treatment,  Storage,  and  Disposal
Facilities").   If  the collected  material   is  discharged  through   a  point
source  to  waters of the  United  States,  it is  subject  to  the  requirements
of Sees.  301, 304,  and 402 of  the  Clean  Water Act,  as  amended.    If the
material  is  discharged to  a  Publicly  Owned Treatment Works  (POTW),  it is
subject to the provisions of  Sec.  307  of the Clean  Water Act,  as  amended.
If  the  material   Is  released  to  the  environment  outside  the  secondary
containment system,  it may  be subject  to  the  reporting  requirements  of 40
CFR Part 302.

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7-20

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                                             OSWER Policy Directive  No.  9483.00-1

                                        7-21

                       7.4   TYPES OF  SECONDARY CONTAINMENT

    Secondary containment for  aboveground, onground.  inground,  and  underground
tanks must include one of the  following devices:   (1) a liner external  to  the
tank  (Figures  7-4,  7-5); (2)  a  vault  (Figure  7-6);  (3) a double-walled  tank
(Figures  7-7,  7-8);  or  (4) an  equal  device   approved  by  the  EPA  Regional
Administrator, as  specified in Sec.  264.193(c)(l-4).  Both liners  and vaults
may have one or more tanks  located  within the secondary containment  area.

    An example of an  innovative "equivalent  device"  that may be approved  by a
Regional  Administrator  is   an   internal   double  bottom  welded   within   an
aboveground  tank.   In  this example.  Sec.   264.193  requirements  for  release
detection and for complete  secondary containment  can  be  met by  constructing an
interstitial-monitoring  system and  an   impermeable  berm  for  the  aboveground
portions  of  the  tank  system,  respectively.   All   equivalent applications  must
demonstrate that the  devices  have  sufficient  structural  integrity  to  collect
releases and to allow for waste removal, as  per Sec.  264.193.

Sections  7.5,  7.6,  and 7.7   of  this  document  cite  the   specific  regulatory
requirements for  eacui type of tank   secondary  containment system  and  provide
guidance for achieving the  Sec. 264.193(d)  standards.

                            7.5  LINER  REQUIREMENTS

    Citation

    Section 264.193(e)(l) states  that a tank  excavation liner must be:

    (i)    Designed or operated to contain  100 percent of the  capacity of
           the largest tank  within  its boundary;
    (ii)   Designed  or  operated  to  prevent  run-on   or  infiltration  of
           precipitation into the  secondary  containment  system  unless the
           collection  system  has  sufficient excess  capacity  to  contain
           run-on  or  infiltration.   Such  additional  capacity  must  be
           sufficient  to contain  precipitation from  a 25-year,  24-hour
           rainfall  event.
    (iii)  Free of cracks or gaps;  and

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                                          7-25
 Sampling
 Standpipe
   or

 Electronic
 Liquid
 Detection
DOUBLE-WALLED  STEEL TANK
                                                                 Exterior  Prottctlon:

                                                                  - Coal-tar •poxy with
                                                                    sacrificial anodes. or

                                                                  •FRP Coa'ing
                                           Interstitial Space
                    NOTE' May not b* present for electronic monitoring
                   DOUBLE-WALLED   FRP TANK
                                                                Flfltir* 7-7
                                                            Two Double-Wailed
                                                            Tank Configurations
FIGURES ARE FOR ILLUSTRATIVE PURPOSES ONLY. THEY ARE NOT INTENDED FOR USE AS

CONSTRUCTION DRAWINGS.

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                                  7-26
          Interstitial Space
          (Monitored for
          Vacuum, Pressure,
          Vapor or Liquid)
                Shell Spacer
                  Inner Wall
                Shell Spacer
Coating to Provide
Corrosion Protection
for External Wall
                                  \
                                   Outer Wall
                                                    Figure 7-8

                                                Cross Section:
                                              Double-Walled Tank
FIGURES ARE FOR ILLUSTRATIVE PURPOSES ONLY. THEY ARE NOT INTENDED FOR USE AS

CONSTRUCTION DRAWINGS.

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                                             OSWER Policy Directive No.  9483.00-1

                                        7-27

    (iv) Designed and  installed  to "surrounii the  tank  completely  and to  cover
         all  surrounding  earth likely  to  come  into contact with  the waste  if
         released from the  tank(s)  (i.e.,  capable  of  preventing  lateral  as
         well as vertical  migration  of the  waste).

    Guidance

    Liners  external   to  tank  systems  may  be  used  to  contain  aboveground,
onground,  inground,  and  underground  tanks.   A liner  must  provide  a  complete
"envelope,"  preventing   both   lateral   and  vertical   migration   of  released
material.   Diking  and curbing  around  an  aboveground  tank  should  be  used  in
conjunction  with  a  liner  to contain any  released material  (see  Figure  7-5).
Typical earthen dike construction is  illustrated in Figure  7-9.  A  tank  system
can prevent  run-on  and infiltration  from entering a secondary containment area
by having  diversion dikes  or  ditches,   curbs  on  paved  areas,  or  interceptor
ditches on  open land  to  divert run-on  away from the  system.  An impermeable
cover  ("which  slopes  away  from  the  tank)  over  an  underground  secondary
containment   system   will  also  reduce-  run-on   and   infiltration   into  the
containment area.  As an additional  precaution,  the liner's  upper  edges  should
be folded  towards tt-:-  tank (liner turnback, see  Figure  7-4).   A double-walled
tank, if structurally secure, is sufficient to  prevent  run-on  and  infiltration
of precipitation  into its  secondary containment  area.   Care must  be taken  to
ensure that a leakproof connection is made  between tank  and piping containment
systems (see  Figure  7-10).   Concrete may  also  be  used  as  effective diking and
curbing material.

    The material that  is  usually  the most  effective for the  construction  of a
secondary  containment  excavation  liner   is  a  synthetic,  flexible  membrane.
Other  materials,  such as  clay,  bentonites, soil  cement,  and  asphalt  can  be
used,  if  they  meet  the impermeability and  durability  performance  standards for
an excavation  liner (i.e.,  for  the   life  of a tank).   Generally clay,  under
good environmental conditions,  and  synthetic membranes are likely  to have the
longest reliable service  lives.

    The  selection  of  an  appropriate liner material  depends  on geologic  site
characteristics, stored waste  characteristics,  and climate.  The  durability of

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                                   7-28
                                    Figure 7-9
                    Typical Earthen Dike Construction
                                      r Mm.
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                                 »»PERV1OUS CORE
                                    2' Mln.
                                              s
                                                        with bould«r or leg w»l«ht backfilled
                                                                         down.
                             MANUFACTUHEO MCMBAANE
FIGURES ARE FOR ILLUSTRATIVE PURPOSES ONLY. THEY ARE NOT INTENDED FOR USE AS

CONSTRUCTION DRAWINGS.

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                                                   io.ic> Directive  No.  94o-.OG-l

                                        7-30

a   liner,   particularly   a   synthetic,   flexible-membrane   liner,   depends
principally  on  proper   installation   (designed   and   installed  to   prevent
punctures  from  rocks,   debris,   etc.)   and waste  compatibility.   Any  liner
material selected  must  be able  to prevent  releases  for the  lifetime  of  the
tank It is  enclosing.

    The different  liner  materials may  be   used  together  for added  protection
against releases to the environment.  For  example,  soil  cement can  serve  as  a
base for a  synthetic membrane liner.

    Sec. 193(c)(4)  requires  that  the  containment system be  sloped or  designed
to  contain  spills; therefore, any  liner should  have  a minimum  slope  of  1/4
inch per  linear foot  to  a dry well or  a  collection  sump to allow  liquids,  to
drain for detection and  removal.   Liner materials  are  described below.   (For
additional  information, refer to  "Lining of Waste Impoundment and Disposal

Facilities," NTIS  Document PB81-166365, 1980;  and "Recommended  Practices  for
Underground Storage of Petroleum,"  New  York State Department of  Environmental
Conservation,  May 1984.)

    A)    Concrete

    Concrete that  is  used for lining hazardous waste  tanks  is usually composed
    of  Portland  cement,   coarse  aggregate,  fine  aggregate,  water,  and  steel
    reinforcing.   In  addition to adjusting the mix design,  numerous additives
    can be  used to impart specific properties to  the concrete.   The  advantages
    to  using concrete  as  a hazardous waste  tank,  liner  Include  its  durability,
    structural  integrity, and layout flexibility; it can also be  formed into  a
    wide variety  of shapes.   Even  though  the constructed cost  of  concrete  is
    higher than some other types  of liners, the durability of  concrete  and the
    ease of integrating  structural  support with  concrete  liners often  makes
    concrete the least costly alternative overall.

    Concrete liners  must be  carefully  designed  and  constructed, however,  to
    ensure  that  they  do  not deteriorate and  leak.  One  critical  consideration

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                                         OSHER Policy Directive No. 9483.00-1

                                    7-31

with  the  use  of concrete  liners  is  installation.   Concrete  construction
drawings can be difficult to follow, moreover, after  the  concrete  has  set,
it  is often  difficult to  determine  if  the  plan and  specifications  were
followed.    Therefore,  each  phase  of  the construction  must  be  carefully
supervised  to  ensure  that the completed  liner will  perform  properly.   The
American Concrete Institute provides guidance on  the  concrete  construction
practices   in   Specifications  for   Structural   Concrete   for   Building.
Publication 301 (1984).

Generally,  two types  of concrete  can  be  used  for  liners.   Traditional
mass-poured concrete  can  be used  if sufficient reinforcing  steel  is used,
as described below, to control  cracking.  Also,  the  surface can  be sealed
with  a flexible   coating.  . These  coatings  are   discussed  in  detail'  in
Section 7.6, Vault  Requirements.   The  second  type of  concrete that can be
used  for  liners  is pre-stressed or post-tensioned concrete.   In  this  type
of concrete,  the  steel  reinforcing  is  1n  tension,  forcing  the  concrete
into  compression.   This  reduces  the possibility  of  cracks developing in
the  concrete.    In  pre-stressing,  the  'concrete   is  poured  over  taut
reinforcing  steel.   When  the  concrete  hardens,  the  steel   is  released,
compressing  the   concrete.    In   post-tensioned   concrete,   the   steel
reinforcing  is  placed  in  tubes   in  the  concrete.   When   the  concrete
hardens, the steel  is  pulled  taut  and  attached  to the  ends  of the member.
Design and  construction  guidance  for  these  types of  concrete  are  given in
the following documents:

o    American  Concrete Institute  (ACI)  Publication   318,  "Building  Code
     Requirements for Reinforced Concrete" (1983);
o    ACI  Publication   350,   "Concrete   Sanitary   Engineering   Structures"
     (1983);
o    Post-tensioning Institute, "Design  and Construction  of  Post-tensioned
     Slabs-on-Ground" (1986);  and
o    Prestressed Concrete  Institute,   "Guide  Specification  for  Prestress
     Precast Concrete for Buildings" (1985).

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                                                      uireccive
                                    7-32
The  choice  of  which type  of  concrete  to  use  depends  on many  factors.
Traditional  mass-poured concrete  is  more  amenable  to complex  layouts  with
specific  structural  requirements   than   pre-stressed   or  post-tensioned
concrete.  Prestressed  concrete  is  usually fabricated  in  a  factory  and
transported  to  the  site.   Usually  used  for  simple  shapes,   it  Is  most
economical when  mass produced.   Post-tentioned  concrete  is often  used  for
large liners with relatively simple layouts.

Section 264. 193(e)(l)(ii i )  states  that  the liner must be free  of cracks or
gaps.  Cracks  and  gaps  can  be minimized by following accepted  design  and
Installation  practices.   Cracks  can  develop   in  concrete  for   several
reasons.  Cracks can occur  because concrete shrinks while  it  cures.   This
shrinkage can  be minimized  by  careful  attention  to the  water  content of
the  mix  and   by using  shrinkage  control  additives.   The  size  of  the
shrinkage cracks can be minimized by using additional  steel  beyond  that
which is  normally  required  for  strength.    The steel  reinforcing should be
distributed with many  small  bars rather than a  few  large  bars.   Joints in
the  concrete that  allow movement  can  also  be  used  to  minimize cracking..
The  use  of  shrinkage   joints  should be 'minimized,  however,  because  the
joint  seals  are  more   suscept.ible  to failure  than  the  concrete  itself.
Additional steel reinforcing is  generally preferred to additional joints.

Cracking of concrete can  also result from  thermally  induced expansion  and
contraction.  A  change  in  ambient temperature or bright  sunlight can  cause
the  concrete  to expand or  contract.  When 'the concrete  is  constrained by
foundations or the temperature  shift  is  not uniform over  the  structure,
stresses and cracks  In  the  concrete can develop.  The occurrence  of these
cracks  can  also be  minimized  by  using  additional  steel   reinforcing  and
expansion joints, with  additional reinforcing the preferred method.

A third  cause  of cracking is frost  penetration.   Frost  penetration  can be
minimized by  careful attention  to the finishing  of  the   concrete  during
placement.   The  surface  should   be  smooth  to  promote  drainage  and  to
prevent  water  from  standing.   Care  should  be  taken not  to overwork  the
concrete  during  placement,  however,  because  overworking  can  cause  the

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                                         OSWER Policy Directive ,Mo.  9483.00-1

                                    7-33

coarse  aggregate  to  sink,  thus  reducing the  durability of  the  surface.
Air entrainment additives also reduce the possibility of frost damage.

A  fourth  source  of  cracks   in  concrete   is   differential   settlement.
Concrete  is  not  very flexible,  and  if  the  ground  or  foundation  settles
unevenly, cracks can develop in the concrete  or the joint  seals  can become
separated  or  damaged.   A  number  of  ways   can  accommodate  or  minimize
differential  settlement;  the  choice  of  method will  depend  upon the  soil
conditions and  structural  support requirements  of the  liner.   One way to
minimize differential settlement  Is  to reduce total   settlement, which  can
be accomplished  by  compacting  the  underlying soil or  increasing  the  size
of the   supporting  foundation.   The  joint  seals should  be  designed  to
accommodate the expected differential  settlement.

A potential  source  of  gaps  in a  concrete liner is  in  the  joints  between
foundation supports  and  the liner.  In general, interruptions  of the liner
should  be  eliminated wherever possible  to   limit  the  number of  gaps  or
joints  that  require  seals.   Typically,  tanks,   pumps,  and  pipe  racks
require  foundations.   One way  to eliminate   a  gap  in  the liner at these
foundations  is  to  pour the  liner over  the  foundation,  leaving  only  a
horizontal  joint between  the  liner  and the foundation.   The  tank  or other
equipment can then  be placed  on top  of  the  liner;  however,   drainage  must
be provided  under  the  tank to  permit the detection  and  collection of  any
release.  The  design  of  concrete  joints and  seals   is  described   in  more
detail in Section 7.6, Vault Requirements.

Another  design  consideration  for concrete  liners is  the  compatibility of
the liner and the waste.  General  compatability requirements  are described
1n  Section  7.3,   Design   Parameters.    Additional   concerns exist  with
concrete, however,  because of  the  numerous types  of  aggregates,  additives,
and  coatings  used.   If  a  coating   is   used,  then  the  coating   must  be
compatible with the  stored  waste.    If  no   coating  is  used,   then   the
constituents  of the  concrete  must be compatible  with  the  waste.   This  may
require  a detailed  mix  design specification.   In addition, the  seals  used
in the joints must be compatible with the waste.

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                                         OSHER Policy Directive No.  9483.00-1

                                    7-34

B)   Synthetic Flexible Membranes

Synthetic  flexible  membrane  liners  (FML)  are  composed   of  polymeric
materials  in  sheet  form.   These  materials  include a  wide  variety  of
polymers, such as polyvinyl  chloride (PVC),  polyethylene,  polyester,  butyl
rubber,  epichlorohydrin,  and  neoprene.   The  appropriate  liner  material
should be selected on  the basis  of  its  compatibility with stored  wastes,
durability,   permeability,  and  resistance  to  damage during  installation.
Synthetic  membranes   generally   have   a  high  resistance   to  bacterial
deterioration  and  chemical   attack;  however,  the  membrane sometimes  will
fail under heavy loading.

Sections 264.192(b) and (c)  require  that new tank systems be installed in
a manner  that  prevents damage  to the system;  therefore,  efforts  should be
made  during  and  after liner  installation  to  protect  the   material  from
punctures and  tears.   Rocks,  rubble,  and  debris must be  removed  prior to
and   during   base  and   wall    compaction,   In   preparation  for   liner
installation.  Protective layers  above  and below a synthetic  membrane will
protect it from punctures  and promote drainage.

Synthetic membranes are often prone to cracking at low temperatures  and to
stretching  and  distortion  at  very high  temperatures.    Liner seams  and
joints  must  be  properly  sealed  to  prevent  the  release  of  waste,  and
sealants  must  be  compatible  with  the  waste   in  the tank.   Furthermore,
synthetic membranes  need  to  be   protected  from  sunlight  and  ozone  by  a
covering,  a   particularly   important   consideration  for  an  aboveground
membrane.   A  qualified  installation   contractor   should  supervise  the
synthetic membrane liner  Installation  process to ensure  that  all  necessary
quality control measures are Implemented.

Two  references,   the   National  Sanitation  Foundation's   (Ann  Arbor,  MI)
Standard  54,   "Flexible  Membrane  Liners"  (1983)  and the  EPA's  Municipal
Environmental  Research  Laboratory "Expected  Life  of Synthetic Liners  and
Caps"  (1983),  provide  information on and comparisons of  the  various  types
of  synthetic flexible  membranes.   The  issue of service  life  is  discussed
In both publications.  The EPA report states:

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                                         OSHER Policy Directive No. 9483.00-1

                                    7-35

     Selection  of  the  most  appropriate -liner  for a  given  waste/
     environment  situation,  specifically  one  that  will   provide  the
     longest service  lifetime,  is a  difficult task.  Available  data
     on  liner  specifications  and  properties  (both  on  virgin  and
     exposed samples) do  not  provide a clear  basis  for  choice though
     they can  eliminate  some  materials for a given site  or design....
     The  best   approach   to  maximum  serviceability  and  durability,
     economics   aside,  seems   to  be  to  select  the   thickest  and
     strongest FML of a polymer type  consistent  with desired chemical
     resistance and other site-specific requirements.

The  EPA's   recommended  Method  9090,  describes  a  compatibility   test  for
wastes  and  membrane  liners.    See  Appendix  G of  this  document  for  the
descripton of this test.

C)   Clay

Because of  its general availability  in  many areas  and its  low  cost, clay
is often  considered for  a  secondary  containment  liner.   If  the  material
has —a   permeability rate  of  approximately  10"   cm/sec  or  lower and  is
installed properly, such  a liner generally will provide a  suitable barrier
against leakage from a tank.
                                                   f

Clay varies  in  composition  and  permeability  and   is  subject to  drying,
cracking,  and destabi1ization  when exposed to  some organic  solvents.   If a
clay liner  is  not  kept  moist,  usually  by  a  soil  cover,  shrinkage  cracks
may  form.   Clay  also may  be  permeable  to  some materials,  particularly
after exposure to  water.   Furthermore,  installation of clay  liners  can  be
extremely complex, depending upon  the characteristics of  a site and  of  the
clay.  The selection of  a clay material  for a particular liner application
should be based on tests  for suitability,  performed by a  soils  engineer  or
a soiIs chemist.

To be adequately  designed to  prevent releases, an  excavation  must be free
of  water,  and  a  clay  liner  must  be  sufficiently  thick  and  plastic
(pliable),  well-compacted,  and  installed at  the proper  moisture  content.
Clay liners  normally are  not  suitable for use  in  high ground-water  areas.
A  regular  cycle of  very  wet  and  dry seasons  may  also  make  a  clay  liner
ineffective.

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                                         OSWEH Policy Directive No.  9483.00-1

                                    7-36

D)   Bentonites

Bentonltes  are  naturally  occurring,  inorganic  swelling  clays  that  are
usually  chemically  treated.   Mixtures  of   soils  and  chemically  treated
bentonites  may  be   used   to  line  excavations   for  underground   tanks.
Bentonites  have  features  similar  to  natural  clay,   but  bentonites  swell
when wet  to  produce  self-sealing  properties.  Bentonites  may be subject to
destabilization when placed  in contact with  organic solvents.

The following  installation  considerations can  help  prevent  the  formation
of cracks and gaps  in a bentonite  layer:

o    An excavation must be  drained,  stabilized, and  not located in  an area
     of high ground water.

o    A bentonite mixture must be saturated with water and  compacted  with a
    ""steel rol 1 ing  wheel.

o    Water  used to  wet  soil  during  installation  must  not  have,   a  high
     concentration  of dissolved salts.

o    Bentonite layer installation  must be performed during dry weather.

o    Soil chemists  or soil  engineers should  be  present  during construction
     to  ensure  that  the  correct  water,  soil, and  clay  mixtures and the
     correct saturation schedules  are used.

o    Only a  qualified  installation contractor should be  used to  construct
     a bentonite containment  system.

E)   Soil Cement

Soil cement  is  a compacted  mixture of Portland cement,  water, and selected
in-place  soils.   The result  Is a  low-compressive-strength  concrete  with
greater  stability  than native  soils.   A soil  cement liner generally will

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                                             OSHER  Policy Directive  No.  9483.00-1

                                        7-37

    have  medium-   to  low-permeability,  depending   on   the  soil  used.   Since
    permeabilities vary,  a smooth soil  mixture  is preferred,  since  it  produces
    a more  impermeable  structure.  Excessive  cement  in  the  mixture,  however,
    can  lead to shrinkage cracks.

    As  a  rule,  soil  cement  is  more   permeable  than  bentonites, • clays,  or
    synthetic  membranes.   Soil   cement  Is   durable   and  resists   aging  and
    weathering, but  it  degrades  rapidly  with  high-frost penetration.    In  an
    area with  high  ground  water, soil  cement is an inadequate  tank excavation
    liner.   For  these  reasons,   said  cement  should not  be  used  in  locations
    where high water tables or frost may be present.

    To  prevent  the formation   of  cracks  and   gaps,   soil   cement  should 'be
    appropriately moistened to prevent  the liner from  drying too  quickly.   A
    soil  cement   liner  must be  stiff  enough to avoid  slippage  on  excavation
    walls but  plastic  enough  to consolidate  properly.  Lastly,  soil  cement
    must be  cured properly for maximum  structural  integrity.

    F)   Asphalt

    Asphalt,  similar  to  road-paving material,  has  good  strength,  durability,
    and  is relatively impermeable when  properly sealed.   Certain  organics will
    dissolve  asphalt,  however,   so  compatibility  of  a  stored waste  and  the
    asphalt   must   be  definitively  determined  prior   to  liner  installation.
    Typically,  asphalt   is  sprayed  on  a foundation  or . base as  a  sealant.
    Asphalt  emulsions are also used.

                            7.6   VAULT  REQUIREMENTS

    A vault,  generally  constructed of  concrete, is  typically  an  underground
chamber  with  a roof that  will  contain  any released tank contents.  There may
be one  or more tanks  contained  within  a  vault.   An  underground  vault may  or
may  not be  backfilled.   An  unfilled  vault  allows inspectors  to  examine  any
contained tank(s).

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                                             OSHER Policy Directive  No.  9483.00-1


                                        7-38


    Citation


    A vault system  is  subject  to the  following  Sec.  264.193(e)(2)  requirements

and must be:


    (1)     Designed or operated to contain 100 percent of the  capacity  of
           the largest tank within Its boundary;
    (11)   Designed or  operated  to  prevent run-on  or  infiltration  of
           precipitation Into the  secondary  containment  system unless the
           collection  system  has  sufficient  excess   capacity  to  contain
           run-on  or   infiltration.    Such   additional   capacity  must  be
           sufficient  to  contain  precipitation  from  a  25-year,  24-hour
           (rainfall event);
    (Hi)  Constructed with  chemical-resistant  water  stops  in  place  at
           all joints  (if any);
    (1v)   Provided with an  impermeable  interior  coating  or  lining  that .
           is   compatible   with   the  stored   waste  and that  will  prevent
           migration of waste into the concrete;
    (v)     Provided with  a  means to  protect against  the formation  and
           ignition of explosive  vapors  with the  vault  systems, if  used
           for storing or treating ignitable  or  reactive  wastes;  and
    (vir~  Provided with  an  exterior moisture  barrier  or  be  otherwise
           designed or operated  to prevent  migration of  moisture into the
           vault if the vault is subject to  hydraulic pressure.


    Guidance


    A vault typically  consists  of concrete  walls and a concrete   bottom  slab

within which  a  tank is  placed and usually includes a cover.   When  the concrete

is coated  with an  impermeable  material,  the  vault  will  be  able  to  contain

leaks from the tank and provide protection from  potentially  corrosive  soil.


    Generally,  vaults  are  most  effective  when   the  tank(s)  within  them  are
supported  on   cradles  or  saddles.   This design allows  the  tank(s)   to  be
thoroughly  Inspected and repaired on  all  sides  from  within  the vault.   (Figure

7-6 shows  two tanks on  cradles  in a  vault.)  The longer a  tank Is,  the  more

cradles   or saddles are  .needed.   Cradles or saddles  should  support  at  least

120°  of  a  tank's  circumference.   Contact  ideally   should   consist   of   a
metal-reinforcing  wear   plate,   hermetically  sealed   to  a  tank, and  a  metal

saddle,  both resting on a concrete pier.  Alternatively,  although it  is  a  less

desirable  design,  a metal  plate may be sealed to the tank,  resting  directly  on

the concrete  saddle.  Under  no  circumstances should  the  wear plate consist  of

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                                             OSHER Policy Directive  No.  9483.00-1

                                        7-39

decomposable material,  such  as tar-saturated  felt paper,  because  this  moist
surface can encourage corrosion.

    In addition  to ease of  inspection  and  repair, early warning and  material
recovery are facilitated in  a  vault  without  backfill.   Some vaults are  filled
with  appropriate  bedding   and  backfill  material  (e.g.,   sand)   to   provide
structural support for  the  contained  tank(s) and  to  protect against  ignition
of  ignitable materials.  When  a  tank is storing  ignitable  hazardous material,
local fire  codes  may require  the  interior   vault  space  to  be  filled  with  an
Inert  backfill   material.     The   final  rule   eliminates  the   backfilling
requirement  for  vault  systems  as  the  only  means  to  protect  against  fire
hazards,   but  continues  to allow  backfilling as  an  acceptable method.   There
are relatively inexpensive and reliable equipment and instrumentation  systems
to  reduce  the  risks  of  explosion.   These systems Include preventative  measures
such  as   equipment  grounding  and  the  use  of  electrical  equipment   meeting
explosion-proof  service.    In  addition,  suppression   systems  can   also  be
installed which use an explosive  vapor detector,  and provide an  inert  flooding
agent  such  as  a. fluorochlorohydrocarbon  to  flood  the  vault automatically  if
explosive conditions  exist.

    Figure 7-11  shows a schematic,  cross-sectional view of  waterproofing  at a
vault's    base    corner,    detailing    the    water     stop    required    in
Sec. 264.193(e)(2)(iii).  Water stops  must   be  chemically  compatible   with  the
waste(s)   in  a vault.   A vault should  contain  no  top  connections other  than
entry manholes and other  top openings  for piping, vents,  monitoring  devices,
etc.   All  vault openings  require  waterproof  seals.    The  floor  of  a  vault
should be  constructed with  a  slope  (typically  greater  than or  equal to  1/8
inch  vertical  per  foot  horizontal)  that channels any leaked or  spilled  waste
to a collection area.

    Concrete Is  one  of  the  most  common  construction  materials  for   a  vault.
Because  concrete Is  porous  and  some  cracking  is likely,  the interior  of a
vault  must  be  lined  with  an  Impermeable barrier to prevent  releases to  the
environment.    To    minimize  cracking,   the   barrier's    thermal   expansion
coefficient  should  be  similar to  that of concrete  (in  areas  of  temperature

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                                        7-40
Waterproofing
Barrier
                          Reinforcing Steel
                                                               Concrete Cant
                                                                                    i
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                                                       Figure 7-11

                                        Waterproofing at Comer of Vault Base
      FIGURES ARE FOR ILLUSTRATIVE PURPOSES OWL*. THEY ARE NOT INTENDED FOR USE AS

      CONSTRUCTION DRAWINGS.

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                                             OSWER Policy Directive No.  9483.00-

                                        7-41

extremes), and the barrier should have  a  low modulus of elasticity  to  prevent
barrier stresses  from  being  greater  than  the tensile strength of the concrete,
over the temperature range expected  during  use.   Cracks in concrete  may  occur
during curing shrinkage of two-component polymeric materials.

    Selection of  an  impermeable  barrier material  for a concrete vault requires
compatibility of  the material with  the  stored waste and impermeability to  the
waste.    These   characteristics  may   be   temperature-dependent.   Table   7-3
summarizes general  characteristics  of  barrier  systems.   The  permit  applicant
must be able  to  demonstrate  the chemical  compatibility and Impermeability of a.
concrete vault's barrier material.

    Waterproofing  the   exterior  of  a  concrete   vault  requires  a  continuous
membrane  that  completely encloses  the  vault.  Waterproofing  barriers  include
hot- and  cold-applied  materials,  such as  bituminous-saturated  felt  or  fabric,
glass fabrics, and  sheet elastomers.   The thickness or  number of plies varies
with the site-specific water table conditions in  the environment surrounding a
tank.  Waterproofing  membranes  that  are  bonded  to a  tank  are preferable over
unbonded materials.  Vaults  are  generally  unsuitable  in  areas of  high  ground
water because eventually the vault  will deteriorate and fill  with water.  The
American Concrete Institute's (ACI)  "A Guide to the Use of Waterproofing,  Damp-
proofing,  Protective and  Decorative  Barri_er Systems for Concrete" (Publication
515.1R-79, 1984)  provides  extensive  guidance and references on  tank  coatings,
liners, and waterproofing materials  and methods of application.

    Constructing  a  vault   from   concrete   with  reinforcing  steel  provides
additional structural  integrity and  helps  to  prevent cracking.   Reinforcing
bars (rebars) should be coated to prevent corrosion.

    A  tank  contained   within  a  building  may  be  considered   to  be within  a
vault.   The  building,   aboveground   or   inground  
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                                             OSWER  Policy Directive  No.  9483.00-1
                                        7-42
                                   TABLE 7-3
       GENERAL  CHARACTERISTICS OF IMPERMEABLE BARRIERS FOR CONCRETE VAULTS
Severity
Of Chemical
Environment
M1ld
Total Nominal
Thickness Range
Under 40 mil
(1 mm)
Typical Protective
Barrier Systems
Polyvinyl butyral ,
polyurethane, epoxy,
Typical Uses
o Protection against
deidng salts.
Intermediate
125 to 375 mil
(3 to 9 mm)
Severe
20 to 250 mil
(1/2 to 6 mm)
                                acrylic,  chlorinated
                                rubber,  styrene-
                                acrylic  copolymer.

                                Asphalt,  coal  tar,
                                chlorinated  rubber,
                                epoxy,  polyurethane,
                                vinyl,  neoprene, coal
                                tar epoxy,  coal tar
                                urethane.
Sand-fi1 led epoxy,
sand-fi1 led polyester,
sand fi1 led poly-
urethane,  bituminous
materials.
Glass-reinforced
epoxy, glass-
reinforced polyester,
precured neoprene
sheet, plasticlzed
PVC sheet.
                                          o  Improve  freeze-thaw
                                            resistance.

                                          o  Prevent  staining .of
                                            concrete.

                                          o  Use  for  high-purity
                                            water  service.
                                            Protect
                                            contact
                                            cal  solutions
                                            a  pH  as  low as
                                            pending  on the
                                            cal.
                                                                   concrete   in
                                                                   with   chemi-
                                                                         having
                                                                         4,  de-
                                                                         chemi-
Protect concrete
from abrasion and
i ntermi ttent exposure
to di lute acids in
chemical, dairy, and
food processing
plants.

Protect concrete
tanks  and floors
during continuous or
intermittent immer-
sion,  exposure to
water,  dilute  acids,
strong alkalies,  and
salt solutions.
Source:   American Concrete  Institute,  "A Guide  to the Use  of  Waterproofing,
         Oampproofing.    Protective   and   Decorative   Barrier   Systems    for
         Concrete,"  515.1R-79,  (1984),  p.  29.

Note.—Reprinted with permission from ACI.

Continued on next page

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                                                          u11 ei. 11 ve  no.
                                        7-43
                              TABLE 7-3  Continued
Severity
Of Chemical
Environment
Total  Nominal
Thickness  Range
 Typical Protective
   Barrier Systems
      Typical Uses
Severe
20 to 280 mi 1
Composite systems:

a)  Sand-fi1 led epoxy
    system topcoated
    with a pigminted
    but unfilled epoxy;
    and
                                b)   Asphalt membrane*
                                    covered with acid-
                                    proof brick using
                                    a chemical  resist-
                                    ant mortar.
o Protect concrete
  tanks during continu-
  ous or Intermittent
  immersion, exposure
  to water, dilute
  acids, strong
  alkalies,   and   salt
  solutions.

o Protect concrete from
  concentrated acids or
  acid/solvent combina-
  tions.
   Other~membranes may be used depending on chemical  environment.

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                                             OSWER Policy Directive No.  9483.00-1

                                        7-44

                      7.7  DOUBLE-WALLED TANK REQUIREMENTS

Citation

    According to Sec.  264.193(e>(3),  double-walled tanks must be:

    (i)    Designed  as  an  integral   structure  (I.e.,   an   inner  tank
           completely  enveloped  within  an  outer   shell)  so  that  any
           release from the inner tank Is contained  by the outer shell;
    (ii)   Protected,  if  constructed  of  metal,  from both corrosion of the
           primary tank interior and  of the external  surface of  the outer
           shel1;  and
    (iii)  Provided with a built-in continuous leak  detection system	

    Guidance

    A double-walled tank  is essentially  a  tank  within a  tank  (jacket),  with a
vacuum, pressurized, or liquid-filled space between  the inner and outer walls.

    Guidelines  for  the  aspects  of design of  underground,  steel,  double-walled
tanks may be found in the Steel  Tank   Institute  (STI)  publication  "Standard for
                                             •
Dual   Wall  Underground   Steel   Storage   Tanks."   Additionally,   Underwriters
Laboratories,  Inc.  (Northbrook,  ID   will,  for   a fee,  analyze the  structural
adequacy  of  a  double-walled  tank design,  taking into  consideration  loading,
unusual stresses,  etc.

    Double-walled  tanks generally  are made  of one of  the  following materials:
1) metal,  2)  epoxy (with or without  a stone aggregate between the  walls),  or
3)  metal   with  a  synthetic   "wrap"  around   the   external   surface   (see
Figure 7-12).    A   double-walled  metal  tank  must be  protected   from  external
corrosion  just  as a single-walled  metal tank  Is protected,  with a  coating,
cathodic  protection, etc.   Epoxies and vinyl esters are commonly  sprayed on  or
applied to a metal tank surface.   Double-walled,  fiberglass  tanks  are  becoming
Increasingly  common because  of  their  corrosion-resistant  properties.   (See
NFPA 30 for details on  protection  of  the exterior of  double-walled  tanks  from
external  corrosion.)    Internal  corrosion  can  be  prevented  in  double-walled
tanks by ensuring  compatibility with  the hazardous waste stored or treated.

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7-45
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                                             OSHER Policy Directive  No.  9483.00-1

                                        7-46

    Leak-detection within.the  interstitial  space  of a -double-walled  tank  is
generally based on  inspection  of  an observation well but  may  also  be  based on
loss of vacuum, pressure,  or  liquid,  depending on  the  design.   Liquid  probes
may also  be used  to  detect waste  releases or ingress of ground water.   (See
Section  7.3(C)   in   this   document  for  more  information   on   interstitial
leak-detection devices.)

    Double-walled   tanks greatly  reduce  the  likelihood  of   releases  to  the
surrounding  environment.    In  addition  to  the  Installation   requirement  of
Sec. 264.192,  manufacturers'   Installation  Instructions  should   be  followed
explicitly to ensure tank integrity.

               7.8 ANCILLARY EQUIPMENT  WITH SECONDARY CONTAINMENT

    Citation

    Ancillary  equipment must  be  provided  with  secondary  containment  (e.g.,
trench, jacketing,  double-walled  piping),   wi.th  the following exceptions,  as
specified in Sec.  264.193(f):

    o    Aboveground  piping  (exclusive  of  flanges,  joints,  valves  and
         other  connections)  that are  visually inspected  for  leaks on  a
         daily basis;
    o    Welded flanges, welded  joints, and welded  connections,  that  are
         visually  inspected for leaks  on a daily basis;
    o    Sealless  or magnetic  coupling  pumps,  that are  visually inspected
         for leaks on  a daily basis; and
    o    Pressurized  aboveground  piping  systems  with  automatic  shutoff
         devices  (e.g., excess flow-check  valves,  flow  metering  shutdown
         devices,   loss  of  pressure-actuated  shut-off  devices)  that  are
         visually  inspected for leaks  on a daily basis.

    Guidance

    Section 264.193(f)  states  that  all  ancillary equipment,  except  that  noted
above, associated  with a  tank must meet  the  secondary  containment provisions
of  Sees.  264.193(b and c).   Thus,  as  per  Sec.   264.193,  the  ancillary
equipment  associated  with  a   specific  tank must  be  provided with  secondary
containment that:

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                                             OSWER Policy  Directive  No.  9483.00-1

                                        7-47

    o    prevents releases  to soil,  ground  water,  and  surface  water;

    o    detects  and  collects   releases   and  accumulated  liquids   until   the
         collected material  is removed.

    Section 264.193(c)  requires  a  secondary containment  system to  have  the
following characteristics:

    o    compatibility and  strength;
    o    foundation integrity;
    o    leak-detection capability;
    o    adequate drainage;
    o    adequate capacity;  and
    o    excess capacity to accommodate  run-on  and infiltration.

    The potential for leakage from straight runs of aboveground  welded  piping,
sealless pumps  and valves,  and  pressurized  aboveground  piping  (equipped  with
automatic shut-off)  is  substantially  lower than  for  certain other' components
of  ancillary  equipment.    Therefore,   as   cited,  the   secondary  containment
requirement is waived for  aboveground piping  (exclusive of flanges,  joints and
valves  unless  they  are  sealless  and  welded  to the   piping),  sealless  or
magnetic  pumps  and  pressurized  aboveground  piping   systems  with  automatic
shut-off devices  that can  be visually inspected  for leaks  on  a daily basis.
For   all   other   ancillary   equipment,   full   secondary  containment   or   a
demonstration of  no migration or no hazard is  required  in accordance with Sec.
264.193(g).

    Containment for pumps  and valves often  can  be  provided most  efficiently if
it  is  Integrated  with a  tank's  secondary  containment  system.  This  is not
always  feasible,   however,   so  a   separate   secondary  containment   system
specifically  designed for  ancillary equipment  may have  to  be  provided.   For
equipment  like  pumps and  valves  (see  Figure  7-13),  a  liner   and  a  sump  or
similar devices  may be  used to collect leaks.   A sump and its attached troughs
if  constructed  of  concrete,  must  have an  Interior coating   or  liner  that  is
compatible with the stored waste.

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                                             OSWER Policy  Directive  No.  9483.00-1

                                        7-49

    Leak-detection for an ancillary equipment secondary containment  system  may
be provided either  by integrating  the  mechanism used for a  tank  with  that  for
the  ancillary  equipment  or  by  installing  separate  sensors.    Leak-detection
sensors (see document  Section  7.3(C)(2»  along  the lengths of  piping enable an
owner or operator to detect even relatively  small  leaks  or  the entry of  water
anywhere within a piping system.

    To  remove  the  released  waste  or  ingressed water  from  the  secondary
containment system  of the ancillary  equipment,  waste transfer  must first  be
stopped.  The  containment  system then  can be emptied,  if  necessary, to prevent
exposure to workers,  the public, or  to the environment.   The  point  of  leakage
must  then  be  repaired  before waste  transfer   starts  again,   as   required  in
Sec. 264.196(e)<3).

    In  the  following  subsections,  four types of  secondary containment  systems
for  piping'  are described, and their  respective  abilities  to  comply  with  the
requirements are  discussed.    The  four types of  systems are   lined  trenches,
concrete  trenches,   double-walled  piping  and   jacketing.    Lined  trenches
constructed of synthetic  materials are usually  the most cost-effective  means
of secondary containment.

    A)   Lined Trenches

    Piping  trenches  can  be  either covered  or  open-topped.    Covered  trenches
    are required  for  underground piping.   Covered trenches  have  the advantage
    of  avoiding   the  accumulation   of  precipitation  and  thereby  facilitating
    precipitation management.  For a  pressure-piping  system,  a trench  that is
    not  covered   may  not  be  able   to  provide  containment  In  case of  a pipe
    rupture.  At a minimum, a spray shield should be mounted over  the  top half
    of  a  pipeline  to  prevent pressurized  waste from  spraying  out  onto  the
    ground.  The regulations  require that  the secondary containment must cover
    all surrounding earth  likely to come in contact with  any  released waste.

    Liners  for a pipe  trench  should  be  constructed  of  a material  similar to
    that used  to  line a tank excavation.  Clays  and synthetic  membranes  can be

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                                         OSWER Policy Directive No.  9483.00-1

                                    7-50

used to  line  a piping trench.  The seams of  the  liner material  should  be
sealed  to  prevent   releases,  the  material   must  be  compatible with  the
stored  substance,  and  it must  be sufficiently  strong  to withstand  the
stresses  described  in Sec.  264.I93(c)(1) and any additional  stresses  from
pressurized flow if  the  pipeline  should rupture.   No  significant stresses
from  vehicular traffic  should  be  permitted  on  piping.   Static head  and
hydrologic forces on the piping  trench liner  are apt to be  less  than those
on  a  tank  excavation liner  because  of  the  trench's  generally shallower
depth.

As  specified   in  Sec. 264.193(c)(2),  trench  backfill  must  be  carefully
compacted  to   provide the  necessary  support  for   the   liner   to  prevent
failure from settlement,  compression,  or uplift.  The  piping  trench should
be  sloped appropriately  so   that  liquid accumulates  in  a location  from
which  it can be withdrawn.

B)   Concrete  Trenches

Concrete  trenches are  similar to  lined  trenches  in  design principle,  but
they are  much stronger  structurally.   A greater amount  of stress  may  be
placed on  the  exterior  of a   concrete  trench  than on  a  lined  trench,  and
larger loads  may be  placed  on top of  a concrete trench.  When  clad  outside
with  an   impermeable  coating, a  concrete trench  is  able  to   resist  the
infiltration  of  ground  moisture.   The  concrete  piping  trench, must  be
compatible with stored waste.

Concrete,  however,   is  subject  to  cracking   from  frost.    Because   of  the
relatively  shallow  depth of  most tank  ancillary  equipment,   cracking  may
occur  during  heavy  frost.  Thus,  concrete trenches  may allow  releases  to
enter   the  environment  and   would  be  inappropriate  in  these  climatic
environments.

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                                               Honey  Directive  No.  94dJ.OO-i

                                    7-51

C)   Double-Hailed  Piping

Double-walled piping refers to  both  piping  that is factory built  with  two
walls    and    pipe-within-a-pipe     applications     assembled     on-site.
Factory-built piping  may   allow pressurization of  the Interstitial  space
between  the  two walls,  permitting  monitoring for  leaks  using  pressure
readings (see document  Section  7.3(O).

Double-walled piping is equally  applicable  aboveground or belowground,  but
additional   corrosion   protection  measures  may  be   required   belowground.
This type  of piping,   although  available,  has  not  been  extensively  used,
primarily  due  to its   high  cost and  it  Is  considered  most effective  for
stralgnt   runs  of  pipe   with   no  elbows   and  tees.    No  precipitation
management 1s required  for  double-walled piping.  Backfill  for  underground
double-walled piping must  be placed  and  compacted as  specified  in  Sees.
264.192(c)  and (e).  Manufacturers'  instructions for  proper support should
also be  adhered to.   A  cross-section  of  double-walled  piping with  two
contained pipelines  is  shown in  Figure 7-14.

D)   Jacketing

Although  aboveground   straight   piping   is   exempted   from  the  secondary
containment  requirements,   aboveground ancillary equipment  components  such
as  flanges,  valves  and other  connections,  are  not.   Local jacketing  can
provide  cost-effective   secondary   containment   for  these   aboveground
ancillary  equipment components  (flanges,  valves and  fittings)  and can  be
provided with  leak-detection  equipment.  This  system can  only be applied
to aboveground piping  systems,  however.

Local  jacketing  collects  or  contains  leakage  from  local  components  and
directs  the  leaked  material  to  containment  sumps where  it  can  be disposed
of or pumped back into primary  containment areas.

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                   7-52
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                                        7-53

    As  the jacket  is not  pressurized,  leaks  in  the  local jacketing  will  induce
    pressurization.  Therefore,  with  the  use  and  application  of  a  pressure
    indicator  with jacketing  will  enable  even  small  leak  detection  during
    routine inspections.   If  the  leak is  large  enough,  the  level  in the  sumps
    will  trigger the  pump  and  can  then  be  attended  to.

    If  properly  engineered,  the  system  is known  to be extremely reliable  and
    relatively minimal  in  cost compared  to other reliable  systems.   The  system
    works  for  both  liquids  and   slurries and  warrants little maintenance.*
    (See  ASME Codes for Pressure  Piping,  ASME/AWSI, B31,  (1984)  and NFPA  30,
    (1984), for additional  Information.)

                          7.9  SUMMARY  OF  MAJOR  POINTS

    This  subsection summarizes the  information  covered  in this  section  and  may
be used in assuring the completeness of  a Part  8 permit application.   It  also
can  be "helpful  in  planning,  preparing,  and  verifying  the adequacy  of  the
secondary containment system.

    o    Has a  secondary containment  system  for existing  tanks and  ancillary
         equipment been placed into  operation within  the  time  frames specified
         in Sec. 264.193(a)?

    o    W111  a secondary  containment  system   for new  tanks  and  ancillary
         equipment be installed?

    o    Does the secondary containment system accomplish  the following:
    Information  excerpted  from  a  study  conducted  for  the  EPA  by  Jacobs
    Engineering, "Feasibility of Requiring Secondary Containment  and/or,  Other
    Methods Available,  to Contain Potential  Releases  of Hazardous  Haste from
    Ancillary Equipment, March 1986.

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                                         OSWER Policy Directive No.  9483.00-1

                                    7-54

          Prevention of migration  of  waste  or precipitation from the  tank
          system to  the soil,  ground  water,  or surface water  at  any  time
          during the use of the tank system;

          Collection and detection of release  of waste or precipitation;

          Permit removal  of  spilled  or  leaked waste  and/or  accumulated
          precipitation  in  a  timely  manner  in  order to prevent  releases
          from the  containment system?

o    Does  the  secondary  containment  system  meet  the  following  design
     criteria, as a minimum:

          Constructed or lined  with  materials that are compatible with the
          wastes;

    ~--   Have sufficient thickness and strength to  prevent  failure  due to
          pressure    gradients   (static   head   and   hydrological   forces),
          physical   contact  with  the  waste,   climatic   conditions,   and
          stresses  from daily operations (e.g., vehicular traffic);

          Placed on  a foundation  which  provides support to the  secondary
          containment  system,  provides  resistance   to  pressure  gradients
          above  and  below,   and   prevents  failure  due   to  settlement,
          compression, or uplift;

          Have  a leak-detection  system  which  will  promptly  detect  the
          release of the waste  or accumulation  liquids  in the  secondary
          containment system; and

          Is  sloped  or  otherwise designed  and  operated to  remove  liquids
          resulting from leaks, spills,  or precipitation?

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                                         OSHER  Policy  Directive  No.  9483.00-1

                                    7-55

o    Is the accumulated waste  and  precipitation,  if  defined as  hazardous
     under 40 CFR 261,  managed  as a  hazardous waste under  RCRA  ?

o    Do all  concrete sumps  have interior  linings  or coatings?

o    Does the  secondary containment  system  include  one  or more  of  the
     following:

          A  liner (external  to  the  tank);

          A  vault;

          A  double-walled  tank;

          An  equivalent   device   as   approved   by   the   EPA   Regional
          Administrator?

o    For an  external liner  system,  will  the liner:

          Contain 100  percent  of the  design capacity of  the  largest tank
          within its boundary;

          Prevent run-on or  infiltration  or have  the capacity  to  contain
          precipitation from a  25-year,  24-hour storm;

          Be free of cracks or  gaps;

          Prevent lateral  and vertical  migration of the waste?

o    For a concrete vault system,  will  it:

          Contain 100  percent  of the  design capacity of  the  largest tank
          within its boundary;

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                                               poucy uirecuve  NO.  y4aj.uu-i

                                    7-56

          Prevent  run-on  or  infiltration  or  have  the  excess  capacity
          described above for liners;

          Be constructed with chemical-resistant water stops  at  all  joints;

          Prevent migration of  the  waste  through the concrete  by  means  of
          a compatible interior liner or coating;

          Prevent migration of moisture into the vault;

          Protect  against  the  formation  of  and   ignition  of  explosive
          vapors through the use of appropriate equipment?

o    For a double-walled tank:

          Is it designed  as  an  Integral  structure so that the  outer  shell
          will  contain any release from the inner shell;

          If a metal  tank,  is it protected from  corrosion of  the  interior
          surface of the inner shell and corrosion of the  external  surface
          of the outer shel1;

          Does  it have a built-in continuous leak-detection system?

o    Does any of  the  tank or ancillary equipment qualify  for  an exemption
     from the secondary requirement based  on the following:

          Aboveground  piping,  (straight  runs)  that will  be  subject  to
          daily visual inspection;

          Helded  flanges,  welded joints,  and  welded  connections,  that  are
          visually inspected for leaks on  a daily basis;

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                                        7-57

              Sealless  or magnetic  coupling  pumps  that are visually  Inspected
              for leaks  on a  dally  basis;  and

              Pressurized,  aboveground piping systems  with  automatic-  shutoff
              devices  that are  visually  Inspected for  leaks on  a daily basis?
In  addition,  see Appendix  A,  "Completeness  Checklist,"  to verify  compliance
with the requirements of this  section.

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                                             OSWER Policy Directive  No.  9483.00-1

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                   8.0  VARIANCES FROM SECONDARY CONTAINMENT
    Section  264.193(g)(lX2)  regulations  provide  details  on  the  information
the  Regional  Administrator   needs   to  grant  a   variance   from  the   Sec.
264.193(a-f)  secondary  containment  requirements.    As   with   all   variances,
however, the burden of demonstrating compliance with requirements is placed  on
the applicant, i.e.,  the  tank system owner or operator.   Sec.  264.193(h)  lists
the procedures that must be  followed  to request and implement a  variance  from
the secondary  containment  requirements.   The  EPA  intends  to  issue  additional
guidance on  the  variance  provisions  in the  near  future  and   to update  that
guidance as necessary.

    As  indicated in  the  regulations,  there are two  different  courses  by  which
an owner  or operator  can  obtain  a  variance  from  the  secondary  containment
requirements._  First,  the  owner or  operator may demonstrate  to the  Regional
Administrator  that a  particular alternative  design and  operating  practice,
together   with   location   characteristics, .will   prevent  migration   of   any
hazardous  waste  or hazardous  constituents  into the  ground water and  surface
water  as  effectively as secondary  containment with  leak  detection  throughout
the active  life  of  a  tank  system   ("technology-based  variance").   A  second
means  of receiving  an variance from  secondary containment  is  by  demonstrating
that the hazardous waste released from  a tank system will  pose  no  substantial
present or potential  hazard  to  human  health  or  the environment  ("risk-based
variance").   New  underground  tank  systems  are  precluded from  obtaining  a
risk-based  variance  because of  a  mandate  in  HSWA  Section 3004(o)(4XA)  that
new underground tanks be required to utilize a leak  detection  system.

    Rather  than  stating general requirements,  the   EPA  requires an  owner  or
operator  to demonstrate compliance with the tank regulations  using  location,
design, and  waste  characteristic data particular  to the  tank  system  in  order
to obtain  a technical  base  variance.   The  variance provision recognizes  the
fact that  certain site-specific  and waste-specific characteristics may prevent
the movement of  hazardous  constituents into ground  water and surface water.
Consistent  with  other  performance   standards,  this  provision  serves  as   a

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                                             OSWER Policy Directive No.  9483.00-1
                                         8-3
                Comply   with   the   requirements   of   §264.196,   except
                paragraph (d), and
         (ii)   Decontaminate or  remove contaminated  soil  to the  extent
                necessary to:
                [A]  Enable  the  tank system for  which  the  variance  was
                     granted  to  resume  operation with  the capability  for
                     the detection of releases  at least  equivalent  to  the
                     capability 1t had prior to the  release;  and
                CB]  Prevent   the   migration   of  hazardous   waste   or
                     hazardous  constituents to  ground  water  or  surface
                     water; and
         (iii)  If contaminated  soil  cannot be removed  or  decontaminated
                in accordance with  paragraph (g)(3)(11)  of  this  section,
                comply with the requirement of  §264.197(b).
    (4)  The  owner  or operator  of  a tank  system,  for  which  a  variance
         from secondary  containment had been  granted in  accordance  with
         the requirements of paragraph (g)(l) of this  section, at  which a
         release  of  hazardous waste  has occurred  from  the  primary  tank
         system and has  migrated beyond the zone of  engineering  control
         (as established in the variance),  must:
         (i)    Comply with  the   requirements  of §264.196(a),   ,  .
                and (d); and
         (ii>   Prevent  the  migration  of   hazardous   waste  or  hazardous
             -  constituents  to   ground  water  or   surface  water,   if
       ""       possible, and decontaminate or remove contaminated  soil.
                If contaminated  soil  cannot be decontaminated or  removed
                or if  ground water  has  been   contaminated,  the  owner  or
                operator   must   comply    with   the   requirements    of
                §264.197(b); and
         (iii)  If repairing, replacing, or reinstalling the tank  system,
                provide  secondary  containment  in   accordance  with   the
                requirements  of  paragraphs   (a)   through   (f)   of  this
                section  or   reapply  for  a   variance  from   secondary
                containment  and  meet   the  requirements   for  new  tank
                systems  in §264.192  if  the  tank system  is replaced.   The
                owner  or  operator  must  comply  with these  requirements
                even  if  contaminated  soil   can   be   decontaminated   or
                removed  and  ground  water  or   surface  water  has  not  been
                contaminated.
    Guidance
    The  EPA  Regional  Administrator  will  use  the   criteria  listed  in  Sec.
264.193(g)(l) to  evaluate the  validity  of a technology-based variance  to  the
secondary containment  requirements.    Essentially,  a  variance  applicant  must
demonstrate that a  tank  system's  design and operating practices,  together  with
location characteristics, will prevent the migration  of  hazardous  constituents
to  ground  water  and  surface  water  at  least  as   effectively  as  secondary
containment with leak detection.

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                                        8-4

    When  granting  a   technology-based  variance based  on  a  demonstration  of
equivalent  protection  of  ground  water   and  surface   water,   the   Regional
Administrator will  take into  consideration:   (1)  the  nature  and quantity  of
waste in a tank system; (2) the proposed alternative design and operation;  (3)
the  hydrogeologic  setting  of  the  facility;   and  (4)  any  other factors  that
would  influence  the quality  and  mobility of  the  hazardous  constituents  and
their potential  to migrate into ground water  and surface water.

    At   their   present   stages  of   technical   development,   the   following
leak-detection mechanisms  may  not  be  able to  qualify  for a  technology-based
variance:   inventory  monitoring,  tank testing,  and ground-water  monitoring.
For  other  methods  of  leak  detection, e.g.   unsaturated  zone  (vadose  zone)
monitoring,  the uncertainty  regarding  their  reliability, accuracy,  etc	  is
sufficient to cause EPA to have concerns  regarding  their acceptability  as  an
equivalent  protection.   Additional  EPA  research  and  1n-the-field  experience
with these methods  should  clarify these concerns  in  the future.  Because  new
leak-defection  technology  is  currently being developed,  at  some future  time
alternative technology may provide as effective leak  detection  and  containment
as  secondary  containment  with  leak  monitoring,  and  the  new  or  improved
technology may be approved for  a technology-based variance.

    A  tank  system owner or operator must  demonstrate  that  an  innovative  tank
system  design  or  leak-detection method,  will be as  effective  as  secondary
containment  with  leak-detection monitoring for  a  particular  hazardous  waste
system.  The variance  applicant must consider in  the demonstration  the nature
and  quantity of  the  hazardous waste,  the proposed alternative  design  and/or
operating  conditions,  the  hydrogeologic  setting,  and  any  other  relevant
factors  (e.g.,  constituent viscosity,  depth  and  permeability  of soil).   The
applicant  must   also   demonstrate   the   reliability  and  capability  of  the
release-detection system used.

    If a technology-based variance Is granted,  the Regional Administrator will
develop  a  set  of  requirements  which will  ensure  that  the  tank   system  is
designed, maintained,  and  operated  In a manner that  prevents  the migration  of
hazardous  constituents  to  ground water and surface water.  If  hazardous waste

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                                             OSHER Policy Directive No.  9483.00-1

                                         8-5

does reach  ground water.or  surface water, the  technology-based  variance  will
be  revoked.    The submission  of  an  unpersuasive  technology-based  variance
application,  such as  earthen berms substituting for  secondary  containment,  is
discouraged  by  the  .EPA.    The  -Agency  also  discourages  the   submission  of
technology-based  variance applications   in  those  situations  where  secondary
containment  is obviously  provided.    For  example,  for   tank  systems  located
inside  buildings, the  building  floor,  if  appropriate berms are  constructed,
would serve as part of  the  secondary containment system.  The Agency  also may
deny the variance if the application is Incomplete.

    A)    Releases to the Zone of Engineering Control.

    The zone  of  engineering control  is  defined  as the area under  the  control
    of  a  tank system owner  or  operator  that,  upon  detection  of a  hazardous
    waste   release,  can  be  readily  cleaned  up  prior   to  the  migration  of
    hazardous, constituents   to  ground water  or   surface  water.   The  zone  of
    engineering control  is   an area  defined in  a  permit variance,  based  upon
    the site-specific hydrogeologic conditions  around  the tank  system(s).   The
    site-specific  definition of  the  zone of  engineering control will  affect
    the granting of variances.   For example,  if a tank system is  located  in  or
    in   close   proximity  to   ground  water or  surface water   a  technology-based
    variance will  most likely not be granted.

    As  per Sec. 264.193
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                                    8-6
If  contaminated  soil  remains  within  the zone of engineering  control,  the
owner  or  operator  must close  the tank  system  in  accordance  with  Sec.
264.197(5) and  provide  post-closure  care  under Sec. 264.197  (see  Section
12.0 of this  document).   If the owner  or operator  decides  to replace  or
reinstall  the existing  tank system,  the tank system must  be  provided with
secondary  containment,   in   compliance  with  Sees.   264.192   and   264.193;
otherwise, the owner  or operator must reapply for a variance  (technology-
or  risk-based)  before  placing  the  tank  system  into  service again.   As
required  by Sec.  264.196(f),  upon  completion of any extensive  repairs to a
tank,   a   certification    by   an   independent,    qualified,    registered
professional   engineer  must  be  obtained  assuring  the tank's  capability of
handling  hazardous  waste.    This  certification must  be  forwarded   to  the
Regional  Administrator  within  seven  days  after returning the tank system
to use.   (See Section 11.0 of this document.)

B)   Releases Outside the Zone of Engineering Control.

As  per  Sec.  264.193(g)(4),  the  response  to  a  release  from  a  tank system
with  a technology-based  variance that  has  migrated  beyond  the  z.one  of
engineering control must  comply with  the measures of Sec. 264.196  (a-d).
(see  Section  11.0 of  this  document).   When  contamination migrates beyond
the zone of engineering control, the EPA considers the  technology on which
the variance  was  granted  to have failed.  If  all  contaminated soil cannot
be  removed  or decontaminated,  or  if ground  water  has  been  contaminated,
the owner or operator  must close  the tank system in accordance  with Sec.
264.197(b) and provide  post-closure  care  under  Sec.  264.197  (see  Section
12.0  of this document).   If all  soil  contamination problems  are remedied
and  there has been  no  ground  water  or surface  water   contamination,  the
tank  system must  be repaired,  replaced, or reinstalled with  full  secondary
containment and  release detection, as per Sec. 264.193(a-f),  or  the owner
or  operator  must reapply for  a variance.  Additionally, replacement tanks
must meet the Installation  requirements of Sec.  264.192 (see  Section  6.0
of  this document).

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                                         OSWER Policy Directive No.  9483.00-1


                                     8-7


                        8.2  RISK-BASED VARIANCE


Citation


264.193(g).

(2)  In deciding whether to grant a variance  based on  a demonstration
     of  no  substantial  present  or  potential   hazard, the  Regional
     Administrator will consider:
     (i)    The  potential  adverse  effects  on  ground  water,  surface
            water, and land quality taking into account:
            [A]  The  physical   and  chemical  characteristics  of  the
                 waste  in  the   tank  system,  Including Its  potential
                 for migration.
            [B]  The  hydrogeological  characteristics of the  facility
                 and surrounding land,
            CC1  The  potential   for  health  risks  caused  by  human •
                 exposure to waste constituents,
            CD]  The   potential   for  damage   to   wildlife,   crops,
                 vegetation,  and   physical   structures   caused   by
                 exposure to waste constituents, and
   _    -  CE]  The_  persistence  and   permanence  of  the  potential
   ~"            adverse effects;
     (ii)   The   potential   adverse   effects    of    a  release   on
 -           ground-water quality, taking into account:
            [A]  The  quantity   and  quality of  ground  water   and  the
                 direction  of ground-water flow,
            [B]  The  proximity  and  withdrawal  rates  of  ground-water
                 users,
            EC]  The  current and future  uses of ground water in  the
                 area, and
            [D]  The  existing   quality  of  ground  water,  including
                 other sources   of  contamination and  their  cumulative
                 impact on  the  ground-water quality;
     (iii)  The  potential  adverse  effects  of  a  release  on  surface
            water quality,  taking into  account:
            [A]  The  quantity   and  quality of  ground  water   and  the
                 direction  of ground-water flow,
            [B]  The patterns of rainfall 1n the region,
            CC]  The proximity  of the tank system to  surface  waters,
            [D]  The current and future uses of surface waters In  the
                 area and  any water  quality standards established  for
                 those surface  waters,  and
            CE]  The  existing   quality  of  surface  water,  including
                 other  sources  of  contamination  and   the  cumulative
                 Impact on  surface-water quality;  and
     (iv)   The  potential  adverse effects  of a  release on  the  land
            surrounding the tank system, taking into  account:
            [A]  The patterns of rainfall in the region, and
            [B]  The  current  and  future  uses  of   the   surrounding
                 land.

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                                                                    l W .  ,/ -r J w •
                                         8-8

    Guidance

    The  EPA  Regional  Administrator  will  use  the   criteria  listed  in  Sec.
264.193(g)(2) to  evaluate  the  validity  of  a risk-based variance  application.
A tank  system owner or operator must demonstrate  to  the  EPA that in the event
of a  release  from a hazardous  waste  tank system,  the  level of  contamination
that  would  result  will  not  pose  a substantial present or potential  hazard  to
human health  or  the environment.   Again, new underground tank systems  are not
eligible for  a risk-based variance under Sec. 264.193(g)(2) .

    When  granting  a  risk-based  variance  based  on  a  demonstration  of  no
substantial  present or  potential  hazard to human  health  or the  environment,
the  Regional Administrator  will  take  into  consideration  potential  adverse
effects on  ground  water,  surface  water and  land  quality.  Specific  factors  to
be   examined   Include:    waste   toxicity  and   migration   potential,   site
hydrogeology _and  land uses,  soil  characteristics,  permanence  of  potentially
adverse  effects,   ground-water  and surface-water  quality  and usages,  current
and future  land use, and local  climate.

    A  risk-based   variance  applicant  can  take  one  of  two  approaches  to
demonstrate   that  no  present   or  potential  hazard  to human  health  or  the
environment will occur:

    1.   There  is  no  pathway  for  exposure  to  humans   for  the  hazardous
         constituents  (no exposure pathway), or

    2.   Exposure  to  ground-water  or  surface-water contamination does not pose
         a  substantial present  or  potential  hazard to  human  health or  to the
         environment (no substantial hazard).

    Essentially,   the  EPA   is  requiring  the  applicant  to  perform  a  risk
assessment  for  current and future  hazards to  human health or  the environment.
To  perform  such  an   assessment,  the  applicant  must  evaluate  the  exposure
pathway,  which  is  composed of   three  inclusive  components:    a  source  of
contamination,  a   contaminant  transport  medium,  and  a   set  of   current  or

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                                             OSHER Policy Directive  No.  9483.00-1

                                         8-9

potential  future  receptors.   Since  "future  use"  of   ground  water  must  be
protected, lack of current receptors does not necessarily mean  that  a  variance
will  be  granted.   All  of  these  three  components  must be  present  to  have  a
complete exposure  pathway (number  1,  above).   Obviously,  if one or  more  of
three  components  are  not  present  then  developing a  case  for  a  ri-sk-based
variance  under  number  1  may  be  feasible.   Assessing  the  seriousness  of
exposure,  [i.e.,   the  concentrations  of  a  constituent,  and the hazards  such
exposure  represents  for  individual   chemicals  and  their  combinations]  is
critical   for  a  successful  risk-based variance  demonstration under number  2,
above.

    Using the  Sec.  264.193(g)(2)  listed  criteria,  the  Regional  Administrator
will  evaluate  each  application  for a   risk-based  variance.   Site-specific
information   on   sources   of   release,   transport   media,   and   receptor
characteristics  must  be  supplied  to  the Regional  Administrator so  that the
impact(s) ofj release can  be  identified.   The type and  amount  of  information
needed Tor  a  risk-based  variance  demonstration  depends  on  site-specific
characteristics  and  which demonstration  approach  (no  exposure  pathway or  no
substantial  hazard,  numbers  1  and  2,   respectively)  is undertaken.   As  much
quantitative and qualitative  information  as  possible should  be  supplied  for  a
risk-based variance demonstration.

    A)   Source.

    A  reasonable estimate  of a  likely  worst-case  release  incident  must  be
    supplied  for  both  types  of  demonstrations.   For   example,  a  likely
    worst-case  release  Incident  from an  aboveground  tank  system  might  be  a
    catastrophic rupture, releasing the  entire contents of  the tank.    For  an
    underground  or inground  tank system, the  most likely  worst-case  release
    event might be a continuous release  over a long period of time.

    Data on  the hazardous  constituent  concentration(s) and  physical/chemical
    characteristics  must   be  supplied   for   both  demonstrations.    For   a
    no-substantial-hazard   demonstration,    the   variance   application   must
    demonstrate  that   as  long  as   the   concentration   for   the   hazardous
    constituents of  concern remains  at  or  below  the  requested  concentration
    limit,  and  that  such  concentration  limits  do not   present  substantial
    current or ootential  hazards to human health or the environment.

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                                     8-10
 The  allowable   hazardous   constituent   concentration   llmlt(s)   for   a
 risk-based  variance will be based  on  levels  that do  not  pose substantial
 hazards   at   the   current   or   potential  future  point  of  exposure.   The
 allowable  constituent  concentration   Hmit(s)   must  be   derived  from
 acceptable  exposure  levels.   EPA-published  acceptable exposure levels for
 human health  and  the environment  (Federal  Register,  July  29,  1985)  can
 generally be  used as  allowable constituent  concentration  limits  without
 performing  elaborate  exposure  pathway  analyses or   fate  and   transport
 modeling.  For example,  a  health-based, acceptable  ground  water exposure
 concentration for  a constituent that might migrate  to ground water can  be
 used as  the  concentration  limit.  However,  the  applicant  may  have  to
 address  the  cumulative effects of  exposure  to a constituent  over time  by
 modifying the detectable concentration  limit  in  the  waste.

 8)    Transport Media.

 In  order to  determine how  quickly  hazardous  constituents  will  migrate,  the
 site's   hydrogeologic  and  ground-water  flow   characteristics   must   be
'supplied  for  both  demonstrations.   The  unsaturated  zone  is  the  transport
 medium  of  primary concern  in  the demonstration  of  no  migration  for   a
 variance  application.   Migration  of waste is most  likely to occur  in  the
 unsaturated   soil   beneath  or adjacent  to a   tank  system.    Results  from  a
 risk-based   variance   demonstration  should   indicate   the  ability  of   the
 unsaturated  zone  to attenuate  waste.

 A risk-based variance application  should contain a detailed evaluation  of
 site hydrogeology  and  estimated contaminant  fate  and transport.   Such  an
 evaluation might  include information  such as  the  following:

      o     Soil  characteristics  (e.g.,  porosity,  density)

      o     Aquifer  characteristics  (e.g.,  depth,  thickness, yield,  use)

      o     Estimation   of degradation  potential   (for  given  constituents)
           within  the  unsaturated  zone;  and

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                                             OSHER Polio Directive  No.  9483.00-1

                                        8-11

         o    Estimation  of  adsorption  potential   (for  given  constituents)
              within the unsaturated zone.

    Other   information   required   -for  a  risk-based   variance  demon's trat ion
includes  current  ground water  quality  (including other  sources  of  potential
contamination), surface  water proximity and quality  information, and  rainfall
patterns.

    C)   Receptors.

    Any modeling  procedures and  results  used   to  evaluate  the potential  for
    migration  should  be  included  in  the variance  application.   Information
    needed   includes   documentation   of  the   model's   approach   and  -its
    applicability,  all  parameter  values  used  (with  relevant  sampling  data),
    all  assumptions associated  with  the model,  and associated  error with  the
    model.  The conceptual  model  developed  for  the unsaturated zone  should be
    ful r? described.

    The applicant  should  demonstrate no  contaminant  migration  to  a  level  of
    certainty which will ensure  that results and conclusions are accurate  and
    reliable.   This level of  certainty  should  account for conditions  that  may
    occur as  a consequence of  future  natural  events  or uncontrolled  human
    intrusion.   To attain an adequate level  of certainty,  the applicant should
    provide  an estimate of  error  that is based on  a  sensitivity analysis that
    accounts for all parameters  included  in  the analysis.  All  data  should be
    demonstrated  to be  accurate.   Field  data  (such  as  hydraulic  conductivity
    developed using Test Method  9100)  should be used  to calibrate  and  verify
    modeling calculations.

    Population and  land-use receptor details  must be supplied for  both  types
    of demonstrations.  The risk  must  be  estimated for  an individual   but  the
    potential   population   to   be  exposed   must  also   be   identified.    The
    population drinking  and  using affected  ground water  (including  current  and
    future  rates  of usage)  and,  if the ground  water flows  to surface water,
    the  population  drinking   and   using   affected  surface   water  must   be

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                                                    w/iicy Directive  N^.

                                        8-12

identified.  Wildlife,  crops,  and  vegetation  that may  come  in  contact  with
contaminated  soils  or  water  must  also  be  Identified.    Potential   future
receptors and land uses should also be described.

    D)   Risk-Based Variance Examples.

    Certain  situations  where it  may  be feasible  for  owners  or  operators  to
apply  for  risk-based  variances  are described below.  As  previously  discussed,
there are  two approaches  to demonstrating  that no present or  potential  hazard
to  human  health or  the environment will  occur:   (1) no  exposure pathway;  and
<2) no substantial hazard.   A  detailed example showing how  to determine which
approach  to use  and  how  to  then use  It  will   be  part of  the  EPA   (to  be
published) Guidance Manual  for  Risk-Based  Variance from  Secondary  Containment
of Hazardous Naste.

    A  demonstration  of no  exposure pathway may  be  achieved  for a  variety of
situations.  For  example,  hydrogeologic   settings exist which  preclude  the
possibility of  waste  constituent  migration to ground water.   Many of these are
described in the EPA document (to be published) entitled  Guidance Criteria for
Identifying  Areas  of  Vulnerable   Hydrogeologv.   Considering  the   cost of  a
thorough  hydrogeologic  analysis,   however,  it  may be  more  cost-effective  in
some  situations  to install  secondary containment than  to  attempt  to  develop
the information necessary  to support  a demonstration of  no  migration.   On the
other  hand,  for  those  parties  having hydrogeological   site  characterization
Information  readily   available  (e.g.,  land  disposal  facilities),   it  may  be
cost-effective  to apply for  such a variance.

    One  example of  a  hydrogeology that  could support  a demonstration  of no
exposure  pathway  is  a  very  thick.  Impermeable  zone  that  separates  the
uppermost aquifer  from  the lower  part of  the  tank.   However,  if this zone has
an appreciable  amount of porosity caused   by  fracturing or  solutloning  (often
seen  in  areas   of  karst geology  or folded, and/or  fractured bedrock),  or if
surface  infiltration  or  runoff  allows  recharge   to  ground  or surface  water
(exceptions  being   in  areas of  very  arid  climate  where  evapotranspiration
greatly exceeds precipitation), then it is not conducive  to  a  demonstration of
no exposure pathway.

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                                             OSWER Policy Directive No.  9483.00-1

                                        8-13

    Another example of a hydrogeology that could support a  demonstration  of no
exposure  pathway   is  an aquifer  containing  inaccessible  ground  water.   Such
aquifers,  however,  must not  be  hydraulically  connected  to  surface  water  or
other ground  water.   One  fioal  hydrogeology example -is an  aquifer containing
ground water  which  is unacceptable  for  all uses  because  of  its  undersirable
chemical  or  low yield  characteristics.   This aquifer, however, also must not
be hydraulically connected to surface water or other ground water.

    A demonstration of no substantial hazard must show that,  although there is
a present  or  potential  exposure  pathway, the level  of contamination that would
result  would   not   pose   a  substantial  hazard   to   human  health   or   the
environment.   Such  a demonstration  would  be based on physical, chemical, and
biological characteristics  of the  waste.   An  example  is  attenuation  in -the
soil  supported  by site-specific  data  on fate related characteristics  such as
stability of waste constituents affected by  chemical,  biological,  and  physical
processes.  Such  attenuation must  be  adequate to  deter the contaminants  from
reaching  the  ground  water.   Another example allows  for  adequate  attenuation
such  that if  the ground  water   is  contaminated,  the level  of  contamination
would  not   pose   a   substantial   present  or   potential   hazard.    Such   a
demonstration would  require  modeling of the flow through  the  unsaturated  zone
to  predict   the   concentration   of  contaminants   in  the   aquifer.    These
concentrations would  then  be  compared  to established  standards and/or  be  used
to  estimate  human  intake.    The  intakes  would  be  used  along  with chemical
toxicities to  characterize risk,  and  the  resulting risk would be  reviewed  to
determine whether  it is substantial.

    Important chemically mediated  processes  may involve oxidation,  reduction,
and   hydrolysis.      Important    biologically    mediated    processes    Include
blodegradatlon and biotransformation reactions.   Physically  mediated  processes
can  involve  Ion exchange,  precipitation, and complexation  reactions.   Most  of
the degradation processes depend  on  the  properties  of contaminants as  well  as
environmental   factors  such  as   microbial   populations,  solid  surfaces,   and
dissolved  constituents  present.    Because  environmental  factors  are unevenly
distributed  in  nature,  however,  degradation  and  reaction  rates  are   not
constant and must  be assessed on  a site-specific basis.  Therefore, the use  of
general  information gathered from the literature will  be  of limited value.

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                                                    wiiwjr
                                                                    no.
                                        8-14
                     8.3  VARIANCE IMPLEMENTATION PROCEDURES
    Citation
    264.193(h).  The following procedures must be followed in order  to  request
a variance from secondary containment:
    (1)
    (3)
  The  Regional  Administrator  must be  notified  in writing  by the
  owner  or  operator  that  he   intends  to  conduct  and   submit  a
  demonstration   for   a   variance  from  secondary  containment  as
  allowed  in  paragraph (g)  according  to  the following schedule:
         (i)
                                                                 to
                                                                 in
         (ii)
    (2)
       For  existing  tank  systems,  at  least  24  months prior
       the date  that  secondary containment  must  be provided
       accordance with paragraph (a) of this section.
       For new  tank,  systems,  at least  30 days prior  to  entering
       into  a  contract  for  installation   (New  tanks  are  not
       eligible for a risk-based variance).
As  part  of  the  notification,  the owner or operator must  also
submit to  the  Regional  Administrator  a description of the  steps
                        the  demonstration   and  a  timetable  for
                         steps.   The  demonstration  must  address
                        isted  in  paragraph  (g)(l)  or  paragraph
  necessary   to  conduct
-completing  each of  the
  each  of  the  factors
  (g)(2)  of  this  section;
  The  demonstration  for
                                   must  be completed  within  180
                                   Administrator of an  intent  to
    (4)
                          variance
days after  notifying  the  Regional
conduct the demonstration; and
If  a  variance  is granted  under  this  paragraph,  the  Regional
Administrator  will   require   the   permittee   to  construct  and
operate the  tank  system  in  the manner  that  was  demonstrated  to
meet the requirements for the variance.
    Guidance


    As stipulated  in  the  above citation, the following schedule and procedures
should be adhered to in requesting a variance from secondary containment:
Notice of Intent to
Regional Administrator
(R.A.)
Notice of Intent
Requirements
                 Existing  Tank  Systems

                 24  months  (minimum)  prior
                 to  when  secondary  contain-
                 ment  is  required  [See  docu-
                 ment  Section 7.1 for
                 schedule]

                 1)  Description of  steps
                    necessary to conduct
                    demonstrations
                                             New Tank Systems

                                             (ONLY   FOR   TECHNOLOGY-
                                             BASED VARIANCE).  30 days
                                             (minimum prior to
                                             entering into a contract
                                                for installation

                                             1) Description of steps
                                                necessary to conduct
                                                demonstrations

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                                             OSWER Policy Directive  No.  9483.00-1

                                        8-15

                        2) Timetable for complet-   "  2)  Timetable for complet-
                           ing demonstration             ing demonstration
Completion date for     Within 180 days after         Within 180 days after
Demonstration for a     R.A.  notification             R.A. notification
Variance
If a variance is granted, the owner or operator must construct  and  operate the
tank  system   in   accordance  with  the  proposed  demonstration.   Additional
guidance will be issued by EPA in January, 1987.

                          8.4  SUMMARY OF MAJOR POINTS

    The following  points  summarize the  information  contained  in this  section
which  should  enable  a  tank  system  owner  or operator  to compile  a complete
application for a variance from secondary containment.

    o    What type  of variance application  ~ technology-based  or  risk-based
         vari-ance — is most appropriate for a particular tank  system?

    o    If  it  is  a  technology-based variance application, are  the following
         details included:

              the  proposed   innovative   tank  system  design    and   operating
              character!sties;

              the nature and quantity of waste in the system;

              the hydrogeologic setting of the facility;  and

              any other relevant factors?

    o    If  It  is  a  risk-based  variance  application,   have  the  following
         elements   been   considered   as   part   of   the   "risk   assessment"
         demonstration:

              waste toxicity and migration potential;

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                                        8-16

              site  hydrogeology  and  land uses;

              soil  characteristics;

              permanence   of   potentially  adverse  health  and  environmental
              effects;

              ground-water and  surface-water  quality and  usages;  and

              local  climate,  e.g.,  precipitation  and evapotranspiration?

         Does  the  technology-based  variance application  demonstrate that  the
         technology used will prevent  the  migration of hazardous  constituents
         into ground waters  and/or surface  waters  at least as  effectively  as
         secondary  containment  with  leak detection?

        'Does the risk-based variance  application  demonstrate  that  there  will
         be no complete  pathway  for human  exposure  from  potential  ground water
         or  surface water  contamination  or,  that  there  is   no   substantial
         present  or future hazard to human  health or the  environment?

         Does the variance application  address  the  clean-up of releases  to the
         "zone of  engineering  control"  under  a  technology-based  variance  and
         tank system repairs?
In  addition,  see  Appendix  A,  "Completeness  Checklist," to  verify compliance
with the requirements of this section.

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                                            OSHER Policy Directive No.  9483.00-1

                                         9-1

           9.0   CONTROLS  AND  PRACTICES  TO PREVENT  SPILLS  AND OVERFILLS

    Citation

    The information requirements for tank systems, to be submitted in  a  Part B
permit  application,  are  stipulated  in  Sec.  270.16(1).   They  require  the
applicant to provide:

    Description of controls and practices to prevent  spills and  overflows
    as required under 264.194(b).

These 264.194(b) standards stipulate that

    owners  or   operators  must  use appropriate  controls  and  practices
    [during  transfer operations]  to  prevent  spills  and  overflows  from
    tank  systems  or  secondary containment systems.   These  Include at  a
    minimum:  (1)  spill  prevention  controls,  such as  check valves  or  dry
    disconnect   couplings,  (2)  overfill  prevention  controls,   such  as
    automatic  feed   cutoff   or   bypass   to  a   standby   tank,   and  (3)
    maintenance  of  sufficient  freeboard  in  uncovered  tanks  to  prevent
    overtopping by wave or wind action  or by precipitation.

    This  provision   requires  appropriate  controls   and  practices   to  prevent
spills  during   transfer   operations,   loading  or  unloading  of  a   tank.   The
Agency's  major  concern  is with  releases that  occur during these  operations,
especially at facilities that do not yet have secondary containment systems.

    Most  important  to note  about  the new regulations is that  they apply to the
tank and  all ancillary equipment  including such  devices  as  piping, hoses  and
pumps that  are  used In the handling of  the  waste from its point of generation
to the  hazardous  waste  storage treatment tanks  and,  If applicable,  from  the
hazardous waste  storage  treatment  tank(s) to a point of disposal on-site or  to
a point of shipment for  disposal off-site.   Therefore, when  a hose  is  used  to
empty a tank's  contents into a truck, it is subject to these  requirements.

    Guidance

    Spills can occur at  any  storage tank facility  because of  tank overfilling
and  drainage from  waste transfer  hoses.  Most  of  the  methods  devised  for

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                                         9-2

prevention of  transfer  spills  and  overfills  are  far  more  applicable  with
aboveground  tank,  systems,  where  the  spill  is highly  visible,  than  with  the
less visible  underground systems.

    Guidance  for  complying  with  the  Sec.  264.194(b)  requirements   to  provide
spill/overfill  prevention measures Is provided.

    It  should   be  noted  that  there  is  no  single  best  device  or  operating
procedure  that  will  suit every  situation;  however,  there  are  some  standard
procedures  for  preventing   transfer  spills  and  overfills  with  which  the
applicant  should  be  familiar.    The  next  sections  outline  these  generally
accepted devices and procedures.

    A  description   of  the  transfer   spill/overfill   prevention  procedures
employed at  a  given  facility must  be Included by  the  applicant  in a  Part  B
permit application.

                             9.1   UNDERGROUND TANKS

    A)   Elements  of  an  Overfill  Prevention System  for  Underground  Storage
         Tanks.

    The following are  recommended elements for a complete overfill  prevention
    system:

    1)   Automatic shutoff devices which prevent overfilling.

    2)   Sensors for detecting the level of liquid in the tank.

    3)   High-level   alarms  which  are activated when an  overfill  is about
         to occur.

    4)   Tying  in  the  unloading  process   with   the  overfill  prevention
         system is  recommended  to prevent  any unloading from taking place
         when the overfill prevention system  Is non-operative.

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                                        OSWER Policy Directive  No.  9483.00-1

                                    9-3

5)   A bypass  prevention  system might  also be  included  so that  the
     overfill  prevention system cannot  be  overridden by the  operator.

These elements are discussed below.

     1)   AUTOMATIC SHUTOFF  CONTROLS

     These  controls,  acting  in  conjunction  with  level-sensing  devices,
     perform  three  major functions:  (1)   to prevent  tank,  overfilling  by
     shutting  off the tank-loading  pump at a preset maximum liquid  level;
     (2)   to prevent damage   to  the  tank-unloading pump by  shutting  it  off
     at a  low  level;  and  (3)  to  regulate various  flow valves  to  control
     product flow.  A signal  from the  level-sensing device  is  transmi-tted
     electrically  or  pneumatically to  the  control   system.    Pneumatic
     devices  require  a  regulated  supply of  clean,  dry   instrument  air,
     genexally at 20 pounds  per square  inch (psi).   Electronic  or  electric
     devices  generally  require  115V  line voltage.   (See   Table  9-1  for
     characteristics of  pneumatic  and electronic  controls.)

     2)   LEVEL-SENSING  DEVICES AND  INDICATORS

     A variety  of  devices   is  available   for  detecting  liquid levels  in
     bulk-storage   tanks.     Generally,    these    devices    sense    liquid
     characteristics,  such   as  capacitance  or  thermal  conductivity,   or
     operate on  such  common principles as  buoyancy, differential  pressure
     and   hydrostatic  head.   Devices  which  operate  on   these   common
     principles  act  Independently of  waste-flow   rate,  pressure   and
     temperature.

     Specific  types of  level-sensing devices  and sensors for  bulk-storage
     tanks can be categorized into the  following:

     1)   Float-activated
     2)   Capacitance
     3)   Ultrasonic
     4)   Optical

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                                                                                  uireccive  no.  y4oj.uo-i
                                                            9-4
                                                        TAB L£  9-1

                                  CHARACTERISTICS OF rN-VJCIC Vrt EliCTOSl
               Feature
Transmission distance

Standard transmission signal

Compatibility between irtstruaents
supplied by different aanuficturers

Control valvt compatibility
Co'ipatabtlitv with digital eo-sputer
or data logger

Reliability
Reaction to very low (freezing)
temperatures

Reaction ta electrical interference
(pickup)                _

Operation la hazardous locations
(explosive atmosphere)
Reaction to sudden failure of energy
supply
Sase and cost of Installation

System compatibility



£a*e and cost of maintenance


Dyoaaie response


Operation in corrosive atmosphere


Performance of overall control
systems

Politics (the unoencloned facto;)
                                                       Pneumatic
United to fev hundred feet

3-1.5 psl practically universal

So difficulty
Controller output operates control
valve operator
Pneuaatic-to-electric converters
required for all inputs

Superior if energized v*ith clean dry
air

Inferior unless air supplv is
completely dry

Ho reaction possible
Completely safe
Superior - capacity of system pro-
vides safety aargia - backup
Inexpensive

Inferior

Fair - requires considerable auiiliary
equlpnent
Lower If installation coses are  not
considered

Slower but adequate for  most situations
Suoerior - air supply becomes  a  surje
for isost ins truants

Excellent, If transmission distances
are reasonable

Generally regarded as acceptable but
not the latest approach
Practically unlimited

Varies vith unuficturer

Honstandard signals require soec'
lidention and aa? not be co-scat

Pneumatic operators with electro1
pneumatic converters or electron-
or electric aotor operator recui:

Easily arranged with ainiaua *dd<
equlpoent

Excellent under usual eavironaenc
conditions

Superior
Ho reaction with the system if
properly installed

Intrinsically safe equiyaeat
available Bust be removed for
most maintenance

Inferior - electrical failure as*
disrupt plant - backup
Superior

Goo/i - conditioning and aurilarv
equipaeat aore conoatible cs
systems approach
Higher - becones comoeticlve
Including i&scallatisn is  consider

Excellent - frequently valve becon
Halting factor

Inferior - unless special  consider
is given, and suitable steps  ca
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                                   OSHER Policy Directive No.  9483.00-1
                                9-5
5)   Thermal-conductivity
6)   Oisplacer
7)   Hydrostatic-head

Float-activated,   ultrasonic,   optical   devices,   capacitance,   and
thermal-conductivity  sensors  all   can  be  utilized   in  underground
tanks.  (See Table  9-2  for  an overview  of their applications.)   The
displaced  devices   and  hydrostatic-head  sensors  are   more  often
utilized  in  aboveground  storage  systems  and will  be  discussed  in
greater detail  in the aboveground/inground section.

o    Float-Activated  Devices—Float-activated  devices  are  character-
     ized  by  a  buoyant element  that  simply  floats   on top  of- the
     surface of a  liquid.   Tape-float  gauges  and float-vent valves
     are commonly used types of  float- activated  devices.

     A  simple  tape-float  gauge   designed  for   use   in  underground
     gasoline   tanks  provides  an   above-the-tank   readout  of  both
     gasoline  and  water levels  while  still  prohibiting vapor  loss.
     These can  be  used  for  hazardous  liquids as  well.   (See Figure
     9-1 for illustration.)

     Float-vent valves,  simple and  inexpensive,  are typically  used  in
     underground tanks  as  well.   These valves  are  installed  in  the
     tank's vent line.  The  float  closes the vent line  at  high liquid
     levels and blocks  the  escape  of  air,  causing   the  pressures
     inside the tank  to  equalize with the discharge head  in  the  tank
     truck and  thereby  interrupting  the flow of liquid.   (See Figure
     9-2 for illustration.)
     The float device  also  Includes  a pressure  build-up  relief-bleed
     hole.   Once flow  from  the  tank  truck has  ceased  due  to pressure
     equalization,  the storage  tank  fill  line can be  disconnected  as
     vapor  escapes  through  the  bleed  hole.   The  liquid  remaining  in
     the fill  line  can then  drain into the tank.  If dry-disconnect

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                                                   ^ . I i,J U I ; C » I
                                        9-6
                                    TABLE 9-2

              LEVEL-DETECTION DEVICES FOR UNDERGROUND STORAGE TANKS
           Type
Mon i tor
Liquid     Level
Level    Indication
Alarm and Shutoff Response
  Float Actuated Devices
    Tape-float gauges
 Yes       Gauge     Interfaces with electronic
                     or pneumatic controls
Float-vent valves
Capacitance devices
Thermal -corxJuctl vi ty
devices -
Optical devices
NO
Yes
Yes
Yes
None
Gauge
Gauge
Gauge
Automatic shutoff
Audible alarm and automatic
shutoff electronic controls
Audible alarm and automatic
shutoff electronic controls
Audible alarm and automatic
shutoff electronic controls
Source:   New York  State  Department of  Environmental  Conservation,  "Technology
         for the  Storage  of  Hazardous  Liquids ~  A  State-of-the-Art  Review"
         (January, 1983),  p.  176.

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                          Figure 9-1


                     Tape Float Gauge

                            for

                 Underground Storage Tank
                                          T«p«
Gulda_

Wire*
                             /
                        Float
                                                 Sh«av«a
                                                                      i
                                                                     o
                                                                     o
                                                                      •
                                                                     n
                                                                     to
                                                                     *
                                                                     >
                       Gag*  Board
                                                o
                                                o.

                                                ff
                                                u
                                                *
                                                CO
                                                o
FIGURES ARE FOR ILLUSTRATIVE PURPOSES ONLY. THEY ARE NOT INTENDED FOR USE AS


CONSTRUCTION DRAWINGS.

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                                      OSWER Policy  Olr«ctlv«  9483.OC
                                 9-8
                             Figure 9-2
                         Float Vent Valves
FIGURES ARE FOR ILLUSTRATIVE PURPOSES ONLY. THEY ARE NOT INTENDED FOR USE AS
CONSTRUCTION DRAWINGS.

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                               OSHER Policy Directive Mo. 9483.00-1

                            9-9

 couplings are used, the liquid" will be held  in  the transfer line
 until  draining  can  occur,  thus  preventing  any  spillage  of
 product.

 Developed  as part  of  the  Vapor  Recovery  Stage  I  System  for
 gasoline  distribution  systems,  the purpose of  this  device is to
 prevent product spillage into the  vapor  manifold  to prevent lead
 contamination   of   an  unleaded   gasoline  grade.    It  is  not
 generally  used  for overfill  prevention  purposes,  but  there  is
 some merit in its use for this purpose.

 The  float-vent  valve must  be installed  in  an  "extractable tee"
 connection,  which  permits  removal  of the float  valve  for tank.
 testing.   Important  to  note  is  that  the  Kent-Moore   (Heath
 Petro-Tite Tank Tightness)  test  cannot be run  with  the valve in
_place.

 Float-actuated  devices  are  made  of  a  variety of  materials,
 including aluminum, stainless steel,  and  coated steel,  depending
 upon  the  application.   These devices may  be  used in conjunction
 with  pneumatic  or  electronic devices  to operate  valves,   pumps,
 remote alarms, or automatic shutoff systems.

 Capacitance  Sensors—These   liquid-level  monitoring devices  are
 based  on  the  electrical   conductivity  of fluids.   A  standard
 capacitance  sensor  consists  of  a  rod  electrode  positioned
 vertically  In  a vessel with the  other  electrode  usually being
 the  metallic tank  wall.  The electrical  capacitance  between the
 electrodes Is a measure of the height of the  Interface  along the
 rod  electrode.   The rod  Is usually  electrically Insulated from
 the  liquid In the tank by a coating of plastic.

 Capacitance  devices  are suitable  for use with  a wide  range  of
 liquids,  Including:    petroleum   products,   such  as   gasoline,
 diesel  fuel, jet   fuel  and  no.  6  fuel  oil;   acids;  alkalis;
 solvents;   and  other  hazardous   liquids.   These  may  be used  in

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                                                _ w i vc
                           9-10

 conjunction  with electronic  controls  to operate  pumps,  valves,
 alarms, and other external control  systems.

 Thermal-Conductivity   Sensors — These   devices   operate   on   the
 principle of  thermal-conductivity of  fluids.   A typical thermal-
 conductivity sensor consists  of  two  temperature-sensitive probes
 connected  in  a  Wheatstone  bridge  (a  type  of  electrical  circuit
 configuration.)  Hhen  the  probes  are  situated   In  air or  gas,  a
 maximum  temperature differential exists  between  the  active  and
 reference  sensors,  which  results  In  a  great  Imbalance   In  the
 bridge  circuit  and a  correspondingly  high-bridge  voltage.  When
 the  probes  are  submerged  1n  a  liquid,  the temperature  between
 the  sensors  Is  equalized,  and the bridge is brought more nearly
 Into balance.  The probes may be Installed  through the side wall
 of  a tank or  pipe, or  assembled  together  on  a  self-supporting
.mounting and suspended through a top connection on the tank.

 Thermal-conductivity devices may be used to control  level with a
 good  degree  of  accuracy.  They  may -be used  with  any   liquid,
 regardless of  viscosity  or density.   They may  also  be used with
 immiscible   liquids   and   slurries   and   in   conjunction  with
 electronic controls  to operate  pumps,  valves,  alarms, or other
 external control systems.

 Ultrasonic  Sensors - These devices operate  on  the  principle of
 sonic-wave propagation in  fluids.   A piezoelectric  transmitter
 and  receiver  separated by a  short gap are characteristic of this
 device.  When the short gap fills with  liquid, ultrasonic energy
 Is  transmitted  across  to a receiving element,   thereby  indicating
 the  liquid level.  These devices can be  used  1n conjunction with
 electronic  devices  to operate  pumps,  valves,  alarms,  or other
 external control systems.

 A   sonar  device  Is   another  sonic  technique  used   for  level
 measurement.   A pulsed  sound wave,  generated  by  a  transmitting
 element,  is  reflected  from the Interface between  the liquid  and

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                                        OSWER Policy Directive No. 9483.00-1

                                    9-11

          the vapor-gas mixture and returned to the  receiver  element.   The
          level  is  then  measured in  terms  of the  time required  for  the
          sound pulse  to  travel  from  the  transmitter to  the  vapor/liquid
          Interface and return.

     o    Optical  Sensors—Optical   sensors  operate  on  the  principle  of
          light refraction  in  fluids.   An  optical-level  monitoring system
          consists  of  a   sensor  and  electronic  control   devices.    An
          electronic  signal  is  generated  and  aimed at the  tank-mounted
          sensors,  which  then  convert the  electronic   signal  to  a  light
          pulse.  This  light pulse  is  transmitted  into  the  tank  by  fiber
          optics, through  a prism,  and  out again  via  fiber optics.   The
          light pulse is then converted to a specific electronic  signal  to
          indicate  the  liquid  level.   A  major advance  of this  system  is
          that  it  is   self-checking.   Any  interruption  will   set  off  the
         -alarm,  thereby   automatically   alerting   the   operator   to   an
          equipment malfunction.

          A   common  application   of   an   optical-sensing   system   for
          bulk-storage  tank  is   shown  in   Figure  9-3.   Essentially  the
          sensor detects the level of liquid in the tank  and  transmits  the
          signal to the controller  device  (i.e., control monitor),  which
          in turn activates either the  shutoff  valve or  the level  alarm.

     3)   HIGH LEVEL ALARMS

     High-level  alarms   are  essential   to   a   comprehensive   overfill
     prevention system.  Overfill  alarms  can be  either  audible or  visual.
     When monitoring   several  tanks  at once,  warning   lights  should   be
     assigned  to  each  tank to  alert   the  operator  as   to  which  tank  is
     overfilling.

6)   Transfer Spill-Prevention  Systems  for  Underground Tanks.

Spills  during  transfer operations  can  be   minimized  by  using  couplings
equipped with spring-loaded valves that automatically block flow when  the

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                                 9-12
                                      OSWER Policy Dlr«ctlv« *9483.00
                             Flgur* 9-3
Optical Liquid Level Sensing System for Bulk Storage System
                          Control
                          Monitor
                                                       Conduit Run Typical
   FIGURES ARE FOR ILLUSTRATIVE PURPOSES ONLY. THEY ARE NOT INTENDED FOR USE AS
   CONSTRUCTION DRAWINGS.

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                                        OSHER Policy Directive  No.  9483.00-1

                                    9-13

hoses  are   disconnected.   Quick-disconnect  couplings  equipped  with
ball  valves  and  dry-disconnect couplings  are commonly  used  coupling
types.    Emergency  shutoff  valves  might  also  be  installed  in  the
product  transfer  line  to stop  flow of hazardous  products  in  case  of
fire.  Applications of  these  devices are discussed  below,   (See  Table
9-3 for summary.)

     1)   CHECK VALVES

     Check,  valves  can  be used  1n the  discharge  piping of a  pump  or
     the fill  line of  a  tank to automatically prevent  backflow of  a
     liquid.   Three common types  of check  valves  are:   (1) piston  or
     ball-check valves  which are  typically referred to  as  lift-check-
     valves,   (2)   tilting  disk-check  valves;  and  (3)  swing-check
     valves.   Check valves are  available  in a wide variety of  sizes
     and _ materials  of   construction  to   suit  most   applications.
   "Cross-sectional  views of these  types of check  valves  portray .the
     various  methods of  preventing  backflow and  are  shown  in  Figures
     9-4, 5,  6  and  7.

     2)  COUPLINGS

     When transferring  hazardous materials  from tank  to tank,  spills
     can be  prevented  by using  tight couplings.   Several types  of
     couplings  are  available.   Selection of couplings should be  based
     on  temperature,  pressure, and  the  chemical   properties  of  the
     materials   being  transferred.    H1th   high   temperatures   and
     pressures, couplings must be attached  more securely.   The amount
     of  pressure   a  coupling   generally  can withstand  is   usually
     determined by the  strength of  the base-coupling connection.   If
     applied  properly and at average  working  temperatures:   1)  bolt
     clamps   will   handle  low  pressure, 2) bands  win  take  low  to
     medium   pressures,   and  3)  interlocking  clamps   and   swaged   or
     crimped  ferrules will handle high  pressure.  Chemical  properties
     of materials  being  transferred  might also be  considered when

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                                                          ireceive iiu. y4
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                               9-15
            J-
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            Gate Vatve
 Composed of a body containing
 a gal* that interrupts flow
                              Glob* Valve
                      Valve disk moves axially to
                      rest against valve seat, blocking
                      flow
            Plug Cock
 Composed of a tapered plug with
 center hold that fits snugly Into
 correspondingly shaped valve seat
                                Ball Valve
                        Similar to plug cocks with the
                        exception that the plug is
                        cylindrical
                                                 Figure 9-4
                                              Types of Valves
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                                   9-16
                                   Angle Valve
                                   Similar to globe valve
                                   Diaphragm Valve
                                   Diaphragm functions as both
                                   cloeure mechanism and seal
                                   Butterfly Valve
                                   A 9O-degree turn of valve stem changes
                                   valve from completely closed to
                                   completely open
                                                     Figure 9-5
                                               Types of Valves (Corrt.)
FIGURES ARE FOR ILLUSTRATIVE PURPOSES ONLY. THEY ARE HOT INTENDED FOR USE AS

CONSTRUCTION DRAWINGS.

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                                 9-17
                                       Lift Ch«ck Valve, Gtob«
                                       Uft Ch«ck Vaiv«, Angle
                                       Tilting Disk Check Valve
                                       Swing Check Valve
                                               Figure 9-6
                                           Check Valves Used
                                          to Prevent Backflow
FIGURES ARE FOR  ILLUSTRATIVE PURPOSES ONLY. THEY ARE NOT INTENDED FOR USE AS
CONSTRUCTION DRAWINGS.

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                   9-18
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                                        OSWER Policy Directive No.  9483.00-1

                                    9-19

     selecting couplings, as  certain  compounds  might in some  cases  damage
     the couplings.

     As  previously  mentioned In  this section,   quick-disconnect  couplings
     are popular because they are lighter and, therefore, easier  to  handle
     than other  types of couplings.   However,  when  using  these  types  of
     couplings, additional  measures   must  be taken  to  prevent spills  or
     loss  of  waste   remaining  in  the  transfer lines.  Quick-disconnect
     couplings equipped  with ball valves  can be used  to minimize  spills
     when the  hoses  are  disconnected.   Dry-disconnect couplings  are best
     suited  for  product spill  control  because   they are equipped with  a
     spring-loaded  valve.   This  spring-loaded   valve  is  usually  closed
     until  the coupling  is  attached  and the valve is manually opened 'with
     a  lever.  See Figure 9-8 for a demonstration of the differences among
     available types  of couplings.

   "imbiber  beads  in  the   fill  box  may  be useful in  soaking-up  small
     spills.   These  beads will   absorb  hydrocarbons and expand many times
     their  size.   The owner/operator must be aware that these  beads  do not
     absorb watt-, however,  and  should be  evaluated for compatibility with
     the spi1 led waste.

(C)  Proper Operating Practices  During Loading and Unloading,

In  addition  to   appropriate  spill/overflow  prevention  control   devices,
certain  sound operating practices  also  should be followed to  prevent
spills/overfills during loading  and unloading.   Recommended practices that
are applicable to the  safe  transfer of any  hazardous  liquid  waste include
the following:

(1)  The driver,  operator, or attendant of  any tank  vehicle should neither
     remain  in the  vehicle  nor  leave the  vehicle  unattended during  the
     loading or unloading process.   The delivery hose  is considered  to  be
     part of the  tank  vehicle  during the   loading/  unloading  process,  and
     the person  overseeing   the  process  should  be  aware  of  this  and  any
     potential problems.  In addition, the  responsible person  must be

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                                  9-20
                                          1. Ordinary Quick Disconnect
                                          2. Quick Disconnect Plus Bail Valve
                                          3. Dry Disconnect
                                                       Figure 9-8
                                                  Types of Couplings
FIGURES ARE FOR ILLUSTRATIVE PURPOSES ONLY. THEY ARE NOT INTENDED FOR USE AS
CONSTRUCTION DRAWINGS.

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                                        OSHER Policy Directive No.  9483.00-1

                                    9-2!

     aware  of  all  other  potential  problems  and  dangers  (overfilling,
     leaks,  spills,  vapor  or  liquid  explosions,   fire,  etc.) and  should
     remain  alert  at  all  times.   Human  error   is  the  major  cause  of
     transfer  spill  Incidents,  and In  most cases  spills  can be  avoided
     through  proper  personnel  training  and  alert  observation   of  all
     operations.    To  minimize   the  potential  for  human   error,   some
     companies  prefer  to  have their  own  trained  personnel  oversee  the
     loading/unloading operations.

(2)  Loading  and  unloading  of tank  vehicles should  be  done  in  approved
     locations.

(3)  To minimize  the  possibility of  fire or explosion  when  transferfing
     ignitable  liquids,  motors of  tank  vehicles  or auxiliary  or  portable
     pumps  should  be   shut   down   during   making  or   breaking   hose
     connections.    In  addition,  if  the  motor of  the  tank vehicle  is not
     required for the  loading/unloading  process,  the motor should  be  kept
     off throughout  the transfer  of-the liquid.
        i
(4)  Cargo  tanks   containing  volatile,   flammable  or  combustible  liquid
     should not be  fully  loaded.   Sufficient  space,  or outage,  must  be
     provided   to   prevent   leakage  due  to  thermal   expansion   of  the
     transferred  liquid.    One  percent  is  the  minimum  recommended  outage
     requirement.

(5)  Delivery of Class I  liquids  to underground tanks  of more  than 10,000
     gal.   (3800L)  capacity  must  be  made  by  means of  tight  connections
     between the hose  and fill  pipe.

(6)  No flammable or  combustible liquid  shall  be  transferred  to or  from
     any tank  vehicle  unless  the  parking brake  1s  set  securely  and  all
     other precautions  have been  taken  to prevent  motion  of  the  vehicle.

(7)  To  prevent  the   accidental  mixing  of  Incompatible  materials,  use
     labels, markings,  or  color  codes  on hoses  and  special couplings  that
     can be used only  for transferring  certain wastes.

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                                            OSHER Policy  Directive  No.  9483.00-!

                                        9-22

    (8)  Conduct periodic inspection  of hoses  for leaks.

    Refer  to  National   Fire  Protection   Association   (NFPA)   385  (Section  -
    Loading and  Unloading  of Tank Vehicles)  for more  Information on  loading
    and unloading practices.

                    9.2   ABOVEGROUND/INGROUND/ONGROUND  TANKS

    Transfer spills and  overfills for  aboveground/inground/onground tanks  can
be prevented  by using the  equipment and  practices  outlined in this  section.
Much  of  the  recommended   equipment  and   many  of   the  practices  are   also
applicable to underground tanks,  as cited  in the foregoing  section, Including:

    1)   Installation  of  a  complete overfill  prevention system,  which includes:

         o   -Level  sensors  and  gauges  to  indicate the  liquid  level in  the
              tank;

         o    High-level  alarms;

         o    Automatic  shutdown controls or  automatic flow-diversion  controls
              to prevent  overfilling;

         o    Provisions   for   collecting   overflow   materials   in   case  of
              emergency  overflow to adjacent tanks; and

         o    Daily monitoring of the system by a reliable  Individual.

    2)   Transferring  hazardous  wastes  at  established  stations equipped  with
         curbing, paving, and catchment facilities.

    3)   Use of  dry-connect  couplings on  transfer pipes and hoses  as  used  in
         underground tank systems.

(See Figure 9-9 for an illustration of an  overfill  prevention system.)

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                              9-23
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                                    9-24"

4)   Installation of redundant valves and  instrumentation.
A)   Elements  of an Overfill  Prevention  System for  Aboveqround/Inqround/
     Onground Storage Tanks.
     1)   LEVEL-SENSORS AND GAUGES

     Level-sensing   devices   and   sensors   that   may   be    used    in
     aboveground/lnground/onground tanks include:

     (1)  float-activated
     (2)  displacer
     (3)  hydrostatic-head  -
     (4)  capacitance
     (5)  thermal-conductivity
     (6)  ultrasonic devices
     (7) _optical
    *
     Capacitance  and  thermal-conductivity  sensors,   and  ultrasonic   and
     optical devices  and their  applications  were discussed  in   detail  in
     the underground  tanks  section.   Certain  float-activated  and displacer
     devices  and   hydrostatic-head  sensors  (or  pressure   devices)   are
     primarily  applicable  to aboveground/inground/ onground  tanks  and are
     di scussed below.

     Level-sensing  devices  may be  top-mounted  or side-mounted,  depending
     on the type  of device  and the location of the probe connection on the
     tank.   The material  the probe Is made of  must  be  carefully selected
     to ensure compatibility with the liquid in the tank.

     (See Table 9-4 for a comparison of different  level-detecting  devices
     and the  types of  gauges,  alarms,  and  automatic  controls  with  which
     they can  Interface.)

     o    Float Systems—Float-activated   devices  are  characterized   by  a
          bouyant   member  that  floats   on  the  surface  of  the   stored
          hazardous liquid.   Float devices  are classified on  the basis  of

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                                            OSWER  Policy  Directive  No.  9483.00-1
                                        9-25
                                   TABLE 9-4

             LEVEL-DETECTION  DEVICES FOR OVERFILL PROTECTION SYSTEMS
                 FOR A80VEGROUND/INGROUNO/ONGROUND STORAGE TANKS
Type of Device
Monitor  Level
Liquid   Indi-
Level    cation
Alarm and Shutoff Response
Float-Actuated Devices
Tape or chain float
gauges
Lever and shaft
mechanisms
Magnetically-coupled
Yes
Yes
Yes
Gauge
Gauge
Gauge
Interfaces with electronic or
pneumatic controls
Interfaces with electronic or
pneumatic controls
Interfaces with electronic or
Dlsplacer Devices
Flexure-tube displacer
Magnetically coupled
displa"cers
Torque-tube displacers
Pressure Devices
Head systems on
pressurized tanks
Bubble-tube systems
Pressure gauge-
open vessel
Capacitance Devices
Thermal -Conductivi ty
Devices
Ultrasonic Devices
Optical Devices
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Gauge
Gauge
Gauge
Gauge
Gauge
Gauge
Gauge
Gauge
Gauge
Gauge
                                               pneumatic  controls
                                               Interfaces   with   electronic   or
                                               pneumatic  controls

                                               Mechanical
                                               Mechanical
                                               Interfaces  with  electronic  or
                                               pneumatic  controls

                                               Interfaces   with  electronic   or
                                               pneumatic  controls

                                               Interfaces  with  electronic  or
                                               pneumatic  controls

                                               Audible   alarm   and   automatic
                                               shutoff; electronic  controls
                                               Audible   alarm   and   automatic
                                               electronic  controls

                                               Audible   alarm   and   automatic
                                               shutoff;  electronic  controls

                                               Audible   alarm   and   automatic
                                               shutoff;  electronic  controls

-------
                          9-26
the  method  used  to couple  the float motion  to the  indicating
mechanism  (gauge).    Chain  or  tape-float  gauges,   lever   and
shaft-float   gauges,   and   magnetically   coupled   floats   are
described below.

     Chain or Tape-Float Gauges  consist  of a float connected  by
     a tape or a  chain  to  a board  or Indicator  dial.   Because of
     their low cost  and  reliability,  these gauges  are  commonly
     used  In  large  atmospheric  storage   tanks.   Drawbacks  to
     using these  devices  Include:  (1) potential for getting out
     of  a!1gnment;(2)  corrosion  of  the   float material   when
     improperly  selected;   and   (3)  potential   for   jamming  and
     freezing of the float  linkage.  (See Figure 9-10.)

     Lever &  Shaft-Float  Gauges  are  characterized by  a  hollow
     metal sphere,  sometimes filled  with polyurethane foam,  and
     a lever attached to a rotary  shaft  that transmits the float
     motion to  the  exterior of'the   vessel  via  a  rotary  seal.
     These float  systems  are  applicable to atmospheric  as  well
     as  pressurized  tanks.  Selection  of  an  appropriate  float
     material   is  necessary  to ensure  compatibility  with  the
     hazardous liquid.  (See Figure 9-11.)

     Magnetically Coupled  Floats  consist  of a   permanent  magnet
     attached to  a  privoted mercury  switch.  The float and guide
     tube  that  come  In  contact  with the  measured  liquid  are
     available  in  a  variety  of  materials for  resistance  to
     corrosion and chemical attack.  These  gauges may  be used in
     conjunction  with -pneumatic  and   electronic   controls  to
     operate pumps,  valves, alarms  and  other external  systems.
     (See Figure 9-12.)

Displacer  Systems.   These   devices  use  the buoyant  force  of  a
partially submerged displacer to measure liquid  level.  Accurate
measurement  of  liquid  level  with displacement  devices depends
upon precise knowledge of liquid and  vapor  densities.   These

-------
9-27
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                               9-28
       Float
                                    Packed Bearing
                                                 Float
                                                    Packed Shaft
                                           Figure 9-11
                               Lever and Shaft Float Gauges
FIGURES ARE FOR ILLUSTRATIVE PURPOSES ONLY. THEY ARE NOT INTENDED FOR USE AS
CONSTRUCTION DRAWINGS.

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                                  9-29
                                                              •S
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FIGURES ARE FOR ILLUSTRATIVE PURPOSES ONLY. THEY ARE NOT INTENDED FOR USE AS


CONSTRUCTION DRAWINGS.

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                               9-30
          systems  can  be   used   In  cage  mountings  or   side
          mountings  in  vented  (atmospheric),  pressurized,   or
          evacuated   (vacuum)   tanks.     Three   commonly   used
          dlsplacer  systems~f lexure-tube,  magnetically-coupled
          and torque-tube—are briefly described below.

          Flexure-Tube   Dlsplacers.   as   compared   with   other
          devices,  are  relatively   simple,   consisting   of  an
          elliptical  or cylindrical float mounted on a  short  arm
          connected  to  the  free   end  of  a  flexible tube.   The
          fixed end of  the  same  tube is  attached  to a  mounting
          flange.  These  devices   are  side-mounted  and are  most
          typically   used   to  directly  activate   either   an
          electrical   level  switch  or a  pneumatic   pilot.   (See
          Figure 9-13.)

          Maqnetlcally-Coupled D1splacers are displacer-activated
          units characterized  by  magnetic  coupling.   These types
          of   devices   are   most   often   mounted   in   external
          displacer cages  and  require two tank connections,  one
          above  and   one  below  the  liquid  level.   They  are
          compatible    with   both   pneumatic   and   electronic
          controls.  (See Figure 9-14.)

          Torque-Tube Dlsplacers  are  among the most widely  used
          level-measuring  devices.   This   type  of  device  1s
          suspended on  a  dlsplacer  rod  attached   to  a  torque
          tube.  (See Figure 9-15.)

o    Hydrostatic-Head  or Pressure Devices.    As  with  dlsplacer
     devices,  an  accurate  measurement   of   liquid   level   by
     hydrostatic-head or pressure  devices  depends  upon a precise
     knowledge of  liquid and  vapor  densities  Inside  the  tank.
     Most of these  types  of  systems use standard pressure  or
     differential measuring devices and  are compatible with

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                                    9-31
                               Figura  9-13

                        Flexure-Tube Displacer
                          Mounting Rang*
                                 Flattened
                                  Section
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                                  9-32
                            Figure 9-14
                Magnetically Coupled Displacers
                   Drive Magnet
Non-magnetic Tube
      Magnet Follower
                                                   Dieplacer Cage
                                                     Displacer
FIGURES ARE FOR ILLUSTRATIVE PURPOSES ONLY. THEY ARE NOT INTENDED FOR USE AS
CONSTRUCTION DRAWINGS.

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                                9-33
                            Figure 9-15
                       Torque-Tube Displacer
                                           Torque Tube
        Displacer Rod
                             OSWER Policy Directive  9433.00-1
FIGURES ARE FOR ILLUSTRATIVE PURPOSES ONLY. THEY ARE NOT INTENDED FOR USE AS
CONSTRUCTION DRAWINGS.

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                          9-34
either pneumatic or electronic controls.   Pressure-gauge  systems
on  open  vessels,   bubble-tube  systems,   and   head  systems  on
pressurized tanks are  commonly recommended varieties  of  pressure
devices and are briefly described below.

     Pressure-Gauge Systems   in  open  vessels   are  the  simplest
     application of head-level  measurement,  with  the  pressure-
     measuring element located at  or  below the  minimum operating
     level  in  the  tank.   The  owner or operator  must note  that
     the  pressure  piping  between   the   open   vessel   and  the
     measuring element must  be  sloped  upward  toward the  vessel
     in order  to prevent errors  due  to  entrapped  air or  other
     gases.  A drain  valve  should be  provided  at  the  measuring
     element  to  allow sediment  to be  flushed  from  the  piping.
     This type of  level-sensing device  is compatible with  both
     pneumatic   and   electronic   controls,   although   electro-
     pneumatic  converters  may   be  required   when   electronic
     controls are used.

     A   Bubble-Tube   System  maintains   an   airstream   by   the
     insertion of  a  tube into  the  tank through  which  an  air
     stream  is  maintained.    The  pressure required to keep  the
     liquid out of  the tube  is proportional  to the  liquid  level
     in   the   tank.    Bubble-tube   systems   are   particularly
     appropriate  to  use  with  liquids  that  are  corrosive  and
     viscous,  contain  entraned   solids,  and   are  subject  to
     freezing.   These   systems   are  most  commonly  used   in
     conjunction with  pneumatic  controls,  but  in  most cases they
     may  also  be  used  with  electronic  controls   if  electro-
     pneumatic converters are  provided.   Bubble-tube  systems are
     In most  Instances more  expensive  than  float  or  displacer-
     type  systems   because  they  require  a  constant supply  of
     clean, dry instrument air.  (See  Figure  9-16.)

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                                   9-35
                                  Pressure Measuring

                                      Element

	
-












o

—
0
0
0
o
0
0
c<

Rii





                                                          Air or Gas
                                                           Supply
                                             Constant Row
                                               Regulator
o
o


CO

-------
                               9-36
          With  Head  -Systems  On  Pressurized  tanks,   a   differential
          pressure measurement  is  taken  the  read  the liquid  level.
          When   using    this   system,   any   of   the   conventional
          differential  pressure-measuring  devices may  be used.

     Selection of the  appropriate  hydrostatic/pressure device  is  very
     Important  because  several   factors  can  have an  impact  on   its
     accuracy.   The   density  and  vapor  pressure  of  the  hazardous
     liquid must  be known.   Hydrostatic-heads that are  not used  for
     level  measurement  must  be  eliminated  or compensated for.   The
     level  above the  lower  tank  connection  (I.e.,   the  discharge
     connection  in  the  case  of  an aboveground  tank and  the  fill
     connection  in  the case  of  an  underground  tank)  is   measured  by
     the  differential  pressure  across  the  measuring element.   This
     particular measurement Is accurate  only  if:  (1)  compensation  is
    -made  for any deviation of  the density of  the  liquid;  (2)  the
     connection  of  the  low-pressure side  of  the  measuring  element
     contains  no  liquid  that has  accumulated because of  overflow  or
     condensation; (3)  the density of the air-vapor mixture  above  the
     liquid  is  either   negligible  or compensated  for;   and   (4)   the
     measuring  element  is   located  at  the  same  elevation  as   the
     minimum  level  to  be  measured  or suitable  compensation  is made.
     Finally,  either  pneumatic  or  electronic  controls  may  be  used
     with these devices.

2)  HIGH-LEVEL ALARMS

A high-level  alarm system  Is essential  to performance of  an overfill
prevention  system.   Audible  alarms. Indicator  lights,  or  both   are
acceptable.   When monitoring  several  tanks  at once,  it 1s recommended
that  both  audible  and  visual  alarms be  used.   In   this  case,   one
Indicator  light  per  tank  Is  usually necessary  to alert  the operator
as to  which tank Is overfilling.   In any  event, an  indicator  light
should  be  placed where  it  can  be  readily seen  by the  individual
responsible for the  filling operation.

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                                   OSHER Policy Directive Mo. 9483.00-1

                               9-37

3)  AUTOMATIC SHUTDOWN OR FLOW DIVERSION

Another  Important element  in  the overfill  prevention  system  is  the
automatic  shutdown  or control "device.   In  the  case of  an  impending
overfill,  such  a device  automatically  shuts  down  to stop  or  divert
flow.  This  device  acts  in conjunction with the  level-sensing  device
to perform one or more of the following functions:

     Prevent tank overfilling by shutting off the tank-loading pump.

     Prevent damage  to  the tank-unloading pump by shutting  it  off at
     a low level.

     Operate various  flow-control  valves  and pumps to divert flow to
     another storage tank if an overfill situation occurs.

Control  devices  can  be  provided for  loading a predetermined quantity
of liquids -as  well.  For example, a*  loading   area  at  a tank  truck
loading  station  could  be equipped  with  a  level-sensing device  and
automatic control system  which shuts off the   flow  of  liquid  when a
predetermined level  is  reached  in the tank  truck.   As  mentioned in
the  underground  tanks  section,   automatic  control   devices  can  be
electrical,  pneumatic,   or  mechanical   in  nature.    Electrical  and
pneumatic  controls  tend  to  be  more widely  used  because  they  have
fewer moving parts  and  are more adaptable to  remote  operation.   (See
Figure 9-17.)

4)  EMERGENCY OVERFLOW TO ADJACENT TANKS

An  emergency overflow  system  1s  another  Important  element   in  a
complete  overfill  prevention  system,   since  it  can  be  activated  by
automatic  control   in the  event  that  tank  overfilling  cannot  be
avoided  through  other means  (I.e., pump shutdown).  Such a system can
also be  manually operated in  the event  that  the automatic  control
system malfunctions.   In addition, provisions must be made for a

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                                9-38
                            Figure 9-17
          Loading Arm Equipped with Automatic Shutoff
                                   Automatic Shutoff Valve
             Level Sensing Device
        • Level tensing circuit independent of product flow rate,
          preeeure or temperature
        • Can be operated electrically or pneumatically
FIGURES ARE- FOR ILLUSTRATIVE PURPOSES ONLY. THEY ARE HOT INTENDED FOR USE AS
CONSTRUCTION DRAWINGS.

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                                        OSk£* Policy Directive  No.  9483.00-1

                                    9-39

     final  overflow to the external  environment in case the  entire system,
     tank,   and  emergency  overflow  tank  are  filled  to  capacity.   It  is
     advised that this particular overflow point be made visible.

     5)  MONITORING SYSTEMS

     Sometimes the most minor  details  can seriously interfere with  system
     performance,  but system  failure  can  be minimized  if  the system  is
     monitored on a daily  basis  for such things as expired  batteries,  low
     electrical  connections,  unplugged  inlet cords, etc.

     In addition  to  installing a complete overfill prevention  system  with
     the  appropriate  equipment,  some  other, best  management  practi-ces
     should be followed.   These are  discussed below.
8)   Transfer Spill  Prevention Systems for Aboveqround/
   ""Inground/Onqround Tanks.
     1)   DRY-DISCONNECT COUPLINGS

     As  addressed   in  the   underground   tank  section,   dry-disconnect
     couplings  should  be  used on  transfer  pipes  and  hoses  in  place  of
     quick-disconnect couplings or other  less  reliable  means  of  pipe  and
     hose connections.

     2)  REDUNDANT VALVING AND INSTRUMENTATION

     Because  valving  and  instrumentation  can  malfunction  and  lead  to
     disastrous conditions,  use  of  redundant valving and  instrumentation
     is   recommended.    Redundant   valves   and  instrumentation  are   an
     inexpensive way to  avoid  spills.   The  primary valve  controls  should
     be  visible  to  the  overseer, and  communication  should be  maintained
     with  the  remote   secondary  valve  control   operator during   waste
     loading/unloading.

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                                        OSHER Policy Directive  No:  9483.00-1

                                    9-40

C)   Proper Operating Practices  During  Loading and  Unloading.

     ])   PROPER TRANSFER PRACTICES

     To  ensure  that  proper  transfer  practices   are   followed,   written
     Instructions   should   be  clearly  posted   at  transfer   locations.
     Periodic personnel  training programs are also  recommended.

     Refer to  discussions of  underground tanks In  Section  9.HO  of  this
     manual  for  details  on  proper  liquid   transfer  practices, which  are
     equally  applicable  to  both  underground  and   aboveground/inground
     tanks.   (Also  refer to  NFPA  385  for  further Information on  loading
     and unloading practices.)

     2)  RECOMMENDED AREAS FOR TRANSFER OPERATIONS

     Transfer  operations   should   be   conducted   only  in   specifically
     designated transfer areas  that  are  fquipped  with impervious  surfaces,
     curbing, and spill-catchment facilities, should any spills occur.

     3)  INSPECTION AND MAINTENANCE

     Regular  inspection  and  maintenance  are  critical  to  an  efficient
     transfer  spill-prevention  system.  All  of the elements of the  system
     should  be Inspected on  a  regular basis and   repaired  or  replaced
     promptly  when  damage  is  detected.  Elements   that  should  be  inspected
     include:

          Hoses, piping, fitting, etc.
          Couplings
          Curbs, containment surfaces and  catchbasins
          Loading area assemblies
          Pumps and valves
          All control instrumentation
          All tanks and tank vehicles

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                                        9-41

                         9.3  UNCOVERED TANKS—FREEBOARD

    As  Sec.  264.194(b)(3)  stipulates,  owners  and  operators  of  uncovered
hazardous  waste  tanks must  allow for  maintenance  of sufficient  freeboard to
prevent overlapping  by  wave or wind action or  by  precipitation.   In a tank of
less than  100 meters  in diameter, the maximum height of a  wind-Induced  wave is
four  to  five inches.  Allowing  for  another four to five  Inches  for splashing
on  the sides  and up  to six  inches  for any precipitation,   14  to 16  Inches of
freeboard  Is  considered adequate  for  most tanks,  and 18  Inches  1s  considered
to provide  an even  greater safety margin.  Although these  measurements  are in
most  cases  sufficient,  In  some  situations,  more  or  less  freeboard  may be
required.

    The above 14-18  inch range for freeboard  is usually sufficient  but,  to be
absolutely  sure   it  is  recommended  that  the   following  formula  be used to
establish the_amount of freeboard required for a given tank system.
       "™                                     •              •
                    VR  -   Qt + V
                    VR  »   Required Tank Size
                     V  «   Volume of Waste to be stored;  Gal.
                     0  -   Capacity of System  Supplying  Waste  to  the  tank;
                            Gal./Min.
                     t  *   Required Attendant response  time; min.

                     t  «   5 min. for redundant trip system
                     t  »   5 min for diverse  trip  system
                     t  *   10 m1n for alarm system only  In operation a-rea
                     t  «   15 m1n for alarm system only  in remote area

    For open-top  tank systems  subject  to wind action, the  amount of freeboard
should  be  determined by   the  above  formula  plus  the  capacity  to  contain
precipitation from  a  24-hour,  25-year  storm but in  no case less than 1101 of
the quantity of  hazardous  waste  to be  stored.*  (Indoor open-topped tanks are
not subject to these freeboard requirements.)

3Information  excerpted  from study  conducted  for EPA by  Jacobs  Engineering,
    "Practicality  of  the   2-Foot  Freeboard  Requirement  for  Small  Diameter
    Tanks," March 1986.

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                                            OSHtH Policy Directive No.  9483.uu-1

                                        9-42

                          9.4  SUMMARY OF MAJOR POINTS

    This subsection summarizes  the Information covered in this  section  and  may
be used  In  assuring  the  completeness of a  Part  B  permit application.   It also
can  be  helpful   in  planning,   preparing,   and  verifying  the  adequacy  of  a
spi 11/overfi11  prevention system.

    Does the spill/overfill  prevention system Include the following elements?

    For Underground Tanks

    A)   Do you have the  proper elements for an Overfill  Prevention System?

         1)   Do you have proper  sensors for detecting  the  level  of liquid in
              the tank:

              a)   Float-activated*
              b)   Capacitance*
              c)   Thermal-conductivity*
              d)   Ultrasonic*
              e)   Optical*
              f)   Displacer
              g)   Hydrostatic-head sensors

         2)   Are high-level alarms activated when  a tank overfill is imminent?

         3)   Do automatic shutoff devices prevent  overfilling from occurring?

         4)   Is  the  unloading process  tied  in with  the  overfill  prevention
              system to prevent any unloading when  the system is non-operative?

         5)   Does  the  bypass  prevention  system  ensure   that   the  overfill
              prevention  system cannot be overridden by the operator?

NOTE:   *Most applicable to Underground Tanks.

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                                            OSWhK Policy Uirective  No.  94S3.00-I

                                        9-43

    8)    Do you have the proper elements of - a Transfer  Spill-Prevention System?

         1)   Are   couplings    equipped   with   spring-loaded   valves   which
              automatically block flow when hoses are  disconnected:

                   Quick-disconnect couplings
                   Dry-disconnect couplings

         2)   Are emergency shutoff valves  installed?.

    C)    Are appropriate transfer practices followed?

    For Aboveground/Inqround/Onground  Tanks:

    A)    Do you have the proper elements of an Overfill  Prevention  System?

         1)   Do you  have  proper  level  sensors and  gauges  to  indicate  the
              1iquid level  in  the tank:

              a)   Float-activated**
              b)   Displacer**
              c)   Hydrostatic-head**
              d)   Capacitance
              e)   Thermal-conductivity
              f)   Ultrasonic
              g)   Optical

         2)   Are high-level alarms installed?

         3)   Do  automatic shutdown   controls   or  automatic  flow  diversion
              controls  prevent  overfilling?

         4)   Are there provisions for  emergency overflow to adjacent  tanks  to
              collect overflowing materials?

NOTE:   **Most applicable in Aboveground/Inground/Onground Tanks.

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                                                           C w t I * C
                                       9-44

         5)    Is  the  system monitored daily by a reliable  Individual?

    B)    Do  you  have  the  proper  elements of a Transfer  Spill-Prevention  System?

         1)    Are  hazardous   wastes   transferred   at   established  stations
              equipped  with curbing, paving, and catchment facilities?

         2)    As  with  underground  systems,  are dry-disconnect couplings  used
              on  transfer pipes  and  hoses?

         3)    Are redundant valves and  instrumentation  installed?

    C)    Are appropriate  transfer  practices being followed?
In  addition,  see Appendix  A,  "Completeness  Checklist,"  to verify  compliance
with the requirements of this section.

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                                                   Policy Uireccive fio.  94dJ.OO-l

                                        10-!

                                10.0   INSPECTIONS
    Tank systems must  be  properly inspected on a routine basis to minimize the
probability of  accidental  releases  of  hazardous  wastes  to  the  environment.
Inspections also aid  in  reducing the risks of fire and exposure resulting from
hazardous  releases  and in maintaining  safe working  conditions in and  around
the  storage  area.    Regular   inspections  using  appropriate  and  effective
procedures  are  the  most reliable  mechanisms  available  for  forecasting  the
potential  for tank  system  failure and  secondary containment  system  failure.
Most  effective  inspection   programs  will  identify  excessive  corrosion  or
erosion,  deterioration of   liners  and  appurtenances,  cracking  of welds  and
joints,  cracking  of  concrete   tanks   and  secondary   containment   systems,
structural   fatigue  evidenced by  cracking  of metals,  and leakage  from  pumps,
valves,  or  piping.   Particular  attention  should be  given   to  bottom-to-shell
connections, -flanges,  rivet  holes,  welded  seams,  valves,  nozzles,  pumps,
pump-sets,  bypass piping and  welded brackets.

    The  frequency  of  inspections depends  on  the  likelihood  of  tank  system
failure and on  the  severity  of the threat  to  human  health and the environment
presented by  a  potential  leak  caused by that  failure.   An  inspection  program
must,  at the  very  least,  according to Sec. 264.195 ("Inspections"), consist of
daily visual  inspections of  critical  components and  leak detection data.   The
secondary  containment  system must also  be Inspected at  least  daily,  since it
is  the  last  barrier  between  a  leak  and the  soil,  ground  water,  or  surface
water.    Cathodic-protection  systems  must  also  be  inspected  regularly,  since
they provide  protection against  corrosion  when working  properly  and  may  also
hasten  corrosion  if  not  functioning  according  to  specifications.    Early
detection  and  replacement,  adjustment,  or  repair   of  faulty  equipment  can
prevent  catastrophic   leakage.    Tank  systems may  be  inspected externally  and
internally  but,  since  the  tank  systems  are  usually  in continuous  service,
external inspections can  be  carried out more readily and frequently.

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                                        10-2

    Until  such  time as  secondary  containment which  meets  the regulations  is
installed,  all   tank   systems   must   be  inspected  in  accordance  with  the
requirements   of   Sec.   264.193(1).     For  underground   tanks   which   are
npn-enterable.  a  leak test  that meets  the requirements of Sec.  264.191(a)  or
other  tank Integrity method  as  approved  or required  by  the (EPA)  Regional
Administrator  must  be  conducted annually.   [§264.191
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                                             OSWER Policy Directive No.  9483.00-1

                                        10-3

comply  with   the   specific   inspection   requirements  of  Sees.   264.195  and
264.193(i) (see Tables  10-1  and  10-2).   These inspection requirements  will  be
discussed  individually  in  the following  sub-sections.   Sections  10.1  through
10.4  pertain   to   the   regulations  for   inspection  after  full   secondary
containment is  provided, and  section  10.5 pertains to  the  period  of time from
the  effective   date  of   the  regulations   until  the time  when  full  secondary
containment is provided.


      10.1 SCHEDULE AND  PROCEDURES FOR OVERFILL CONTROL  SYSTEM INSPECTIONS

    Part 8 of the permit application must include a schedule  and procedure  for
inspecting overfill control  systems and monitoring equipment in all tanks:'

    Citation

    Sec. 264.195(a) The  owner  or  operator of a tank system  must  develop a
    schedule  and  procedure  for   inspecting  overfill   controls,  where
    present  (e.g.,  level-sensing  devices,  high-level  alarms,  waste-feed
    cutoff and bypass systems).

Guidance for complying with  this  regulatory requirement  is discussed below.

    Guidance

    Important overfill controls and instruments include:

    o    Flow-rate controls
    o    Level  controls
    o    Temperature gauges
    o    Pressure gauges
    o    Control valves
    o    Alarms and emergency shutoff devices
    o    Analyzers

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                                                          Directive Ho.  9483.00-1
                                        10-4


                                   TABLE 10-1


                             INSPECTION  REQUIREMENTS

                  BEFORE  FULL SECONDARY  CONTAINMENT IS PROVIDED
Regulation Section
Inspection Requirement
Time Frame
264.193(1X1)
For underground,  non-enterable tanks,
one of the following:

-  a leak test that meets the
   requirements of Sec.  264.191(a)
   or
-  other method as approved or
   required by the EPA Regional
   Adminlstrator
Annually
264.193(1X2)
264.193(1X3)
264.193(i)(4)
For other than non-enterable,
underground tanks, a procedure to:

-  conduct a leak test that meets
   requirements In Sec.  264.191(a)
-  assess the overall condition
   of the tank system as approved
   by an independent, qualified,
   registered professional engineer

For ancillary equipment
-  A leak test or other integrity
   assessment as approved by the
   Regional Administrator

A record of the results of all the
above assessments must be maintained
on file at the facility.
A schedule to
be approved by
the EPA Regional
Adminlstrator
Annually
264.193(1X5)
Tank systems found to be leaking
or unfit for use as a result of
the leak test or assessments in
this section must comply with the
Sec. 264.196 requirements -
"Response to leaks or spills and
disposition of leaking or unfit
for use tank systems."

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                                        10-5


                                     TABLE 10-2


                               INSPECTION  REQUIREMENTS

                    AFTER FULL SECONDARY CONTAINMENT IS PROVIDED
Regulation Section
Inspection Requlrement
Time Frame
264.195(a)
264.195(5X1) & (2)
264.195(b)(3)
264.195(c)(l)
Overfill controls
Visual inspection of aboveground
portions of the tank

-  corrosion or releases from fix-
   tures, joints, flanges,  pumps,
   valves, and seams

-  monitoring and leak-detection
   data (pressure or temperature
   gauges, monitoring wells,
   and leak-detection devices)

Externally accessible portion of
the tank and secondary containment
system

-  construction materials
-  surrounding area to detect
   erosion or signs of releases
   (e.g., wet spots, dead
   vegetation)

Proper operation of cathodic
protection system
Develop schedule
and procedures

Dally
Daily
Within six
months of
initial in-
stallation
and annually
thereafter
264.195(c)(2)
Sources of Impressed current
Bi-monthly

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                                                   r\,j  u i I e>. i. i » e .lo.  JTOJ. WO- i

                                        10-6

    A brief checklist of what should be inspected includes:

    o    Transmission systems
    o    Power supplies
    o    Seals
    o    Purges
    o    Panels and enclosures
    o    Electrical equipment
    o    Insulation
    o    Enclosures
    o    Operating Mechanisms
    o    Insulating and lubricating oils
    o    Protective overlays
    o    Bearings
    o    Batteries
    o    Rectifiers

    In most  cases,  instruments  and controls are  visually inspected daily by
the operator,  since  they  are an integral  part  of the  daily  operation  of  the
facility.  Any unexpected  discontinuities  or abnormal  peaks in  data  charts or
data  logs  may   indicate   that  there  is  some   cause   for   concern.    All
instrumentation and  control  equipment  should be thoroughly inspected according
to the manufacturers' recommended frequency and methodology.

    Environmental  conditions,   such  as  heat,  moisture,  chemical  attack,  and
dirt, are  responsible for  deterioration of  electrical  systems.   The  inspector
should specifically  look for these deteriorating effects.
         10.2 DAILY INSPECTIONS OF ABOVEGROUNO PORTIONS OF TANK SYSTEMS
                     AND MONITORING AND LEAK DETECTION DATA
    Citation
    Sec. 264.195(b) the owner or operator must inspect  at  least once each
    operating day:   (1) the  aboveground portions of  the  tank  system,  if

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                                             OSHER Poiicy Directive  No.  9483.00-1

                                        10-7

    any, to detect  corrosion  or  releases of waste; and  (2)  data gathered
    from  continuous  monitoring  and  leak  detection   equipment,  if  any
    (e.g.,   pressure or  temperature  gauges, monitoring  wells)   to  ensure
    that the tank system is being operated according to its  design.

    Guidance

    Dally  inspection   of   the  aboveground  portions  of   the  tank  system  for
corrosion  or  leaks  from  tank  fixtures, joints,  flanges,  pumps,  valves,  and
seams  and   daily  inspection  of  data  from  leak-detection  systems  must  be
standard operating procedure for  tank system owners and operators.

    Gross  leakage  or  corrosion  from  fixtures  and seams  will  be  readily
evident.  This  is the  primary purpose of a  daily  visual  Inspection, which  is
required to detect deteriorating  areas  before  they  create  serious  problems.
Stress  corrosion  around weld  seams,  joints,  and  fixtures  may  occur  on  the
surface  of  the  tank.   Careful  daily  Inspection  of  aboveground portions  for
corrosioa will  usually  allow  detection  of potential  defects,  which  then will
require  further   detailed   examination.    Visual    inspections  are   usually
sufficient   to   locate  major  corroded  areas on   aboveground  portions  of  the
tank.

    In addition to  daily  inspection  for corrosion, the aboveground  portions  of
the tank  shell  should  be  inspected  for  leaks,  cracks,   buckles, and  bulges.
Discoloration  of paint may be an  Indication  of  leakage.

    Cracks  can  be found at nozzle connections,  in welded seams,  and underneath
rivets.  Cracks,  buckles,  and  bulges  can  initially  be  spotted  by  visual
Inspection, and  their extent  can  t»e more  thoroughly  determined  by techniques
like the magnetic-particle,  penetrant-dye or vacuum  box methods (see  Section
10.8,   "Inspection  Tools  and  Electromechanical   Equipment,"  for  details  on
Inspection  devices).

    All valves in the  tank  system  should be visually  inspected  to  ensure that
the  seating  surfaces   are  in  good   condition.    Specific  guidance  is  given
below.

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                                    10-8

A)   Valves, Pipes, Fittings,  and Hosej.

Inspection  of  valves,  pipes,  fittings,  and hoses  is  critical  to  detect
losses in metal  thickness  owing  to external or  internal  deterioration.   In
many cases high liquid turbulence or velocity causes  these  equipment  parts
to  erode  or  wear.  Leaks  are   most  likely to  occur  around pipe  bends,
elbows,   tees,   and  other  restrictions,   such   as  orifice  plates   and
throttling  valves.   Loading   and/or  unloading   hoses   used  as  flexible
connections between vehicles  and storage  tanks  are vulnerable to  wear  and
tear as well.   Traffic  passing  over hoses during loading and unloading  can
also contribute considerably to hose deterioration.

Visual inspection  while  the tank Is in operation  should  include  checking
the following:

     o   -leaks
     o    misalignment of pump shafts
     o    unsound piping supports
     o    vibration or swaying
     o    indications  of pipe  fouling (causing  flow restrictions)
     o    external corrosion
     o    accumulations of liquids

Specific areas that should be  checked for  the above conditions include:

     o    pipe bends
     o    elbows
     o    tees
     o    orifice plates
     o    throttling valves
     o    loading/unloading hoses
     o    pumps

Ultrasonic  or  radioactive  testing  techniques   can  be  employed  as   an
additional  aid   to  measure  metal  thickness   while   the   tanks   are   in

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                                         u:»«t./< PGIIC.X Directive No.  y4aj.uu~i

                                    10-9

operation.   (See Section  10.8,   "Inspection  Tools  and  Electromechanical
Equipment," for details on these testing techniques.)

Pipe connections  in  tank  systems must be  inspected  for  external  corrosion
by  visual  examination, scraping,  and picking.   Piping  should be  scraped
and cleaned during  visual  inspection.  When the tank has shown evidence of
excessive  settling,   piping   connections  that  might  have  been  loosened
should be carefully checked.

Film  lifting  of  the  tank's  protective  coating  is  prevalent below  seam
leaks  and  is  best  detected,  as are  rust  spots  and  blisters,  by  visual
inspection,   aided   by  scraping   th«   film   in   suspected   areas   where
necessary.  Special  attention  should  be paid to paint blisters,  which .are
usually prevalent on the roof and the sunny side of the tank.

8)   Pump* and Compressors.

Although mechanical  wear  is  the  primary cause of deterioration for pumping
and compression  equipment, erosion  and  corrosion can also  be  contributing
factors.   Improper  operating conditions, piping  stresses,  cavitation, and
foundation  deterioration   causing   misalignment   have   been  known   to
contribute to deterioration.

Routine visual  inspections of pumps  and compressors  should   look for the
following:

     o    foundation cracks and uneven settling
     o    leaky pump seals
     o    missing anchor bolts
     o    leaky piping connections
     o    excessive corrosion
     o    excessive vibrations and noise
     o    deterioration of insulation
     o    excessive dirt
     o    a burning odor or smoke

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                                               1-ouc.y
                                    10-10
     o    missing safety equipment such as  a  pump-coupling  guard
     o    depleted lubrication oil reservoir

Vibration  has  been  known  to  deteriorate  a  pump or  compressor  rapidly;
therefore, periodic  inspection of the  vibration  level  should be  conducted
by  using  an  electronic-vibration  meter.    All   assembly  bolts,  gaskets,
cover plates,  and flanges should  be  inspected  as  well  to detect  leaks  and
cracks.

When  a  pump or  compressor is  taken  out of use,  the mechanical  components
should  be  checked for  clearance,  corrosion,  erosion,  deformation,  wear,
and any other changes detrimental  to safe operation.

C)   jteat Exchangers.

Deterioration may be  expected  on  all surfaces  of  exchangers  and  condensers
that contact chemicals, water  (both  salt and fresh), and  steam.   The  form
of  attack  may  be  electrochemical,  chemical, mechanical, or  a  combination
of the three type'.   The attack may be  further accelerated by factors  like
temperature,  stress,   fatigue,   vibration,    impingement,   and   high-flow
velocity.

The exchanger or condenser itself can be visually inspected  for  rust  spots
and blisters.   If  a  unit  is  out  of  use, inspection  procedures  can be  more
detailed.  A  scraper and a  ball-peen  hammer  can be  used   in  conjunction
with a  visual  Inspection  to  detect areas subject to excessive  erosion and
corrosion.  A pressure test  using a  test fluid can  also be  used  to detect
leaks or  excessive erosion or pitting, if  a  more  detailed  investigation is
thought necessary to confirm the results of the visual  Inspection.

D)   Vapor-Control Systems.

Vapor control systems  are most  commonly used  In tanks  that hold  liquids
with a high coefficient of expansion.

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                                                   rwiiv-jr  UIICLLI»C  no .  a to j . uu— i

                                        10-11

    Areas of inspection should include:

    o    The pressure-release valve,  which should  be examined  for  clear  lines.

    o    The  bladder-height  gauge,   which  should  be  Inspected  for   proper
         working condition.

    o    The  area  between  the  bladder  and shell  should  be  checked  with  an
         explosimeter for detection of vapor leaks.

    o    The cycling schedule should  be monitored  to  determine  if the  system
         is in proper operating  condition.

    The  bladder-height  gauge  and  the  pressure-release  valve   are   usually
    located on the  roof of the holding tank.

       "10.3  DAILY INSPECTION  OF CONSTRUCTION MATERIALS, LOCAL AREAS,
            AND SECONDARY CONTAINMENT SYSTEM FOR EROSION AND LEAKAGE
    Citation

    Sec.  264.195(b)<3)  The owner  or  operator must inspect on  at  least a
    daily basis the  construction  materials of,  and  the area  immediately
    surrounding,   the  externally  accessible  portion  of the tank  system,
    including  the  secondary  containment  system  (e.g.,  dikes)  to  detect
    erosion or signs  of  release  of hazardous  waste (e.g.,  wet  spots,  dead
    vegetation).

    Guidance

    Section  264.195(b)(3)   requires  daily  Inspection  of  the   construction
materials  and  the  area  immediately  surrounding  the  external  portion of  the
tank  system and  the secondary  containment   system  for signs  of  erosion  or
releases.   This  daily Inspection  is  Intended primarily to detect  releases  or
the potential for imminent  releases and should include the  following items:

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                                            OSWER  Policy  Directive  No.  9483.00-1

                                       10-12

    o    Releases  or  corrosion  around nozzles  and ancillary equipment of  the
         tank system;

    o    Signs of  corrosion on tank, tops  or  roofs;

    o    Defective manhead  gaskets

    o    Corrosion or  releases,  cracks,  and  buckles on  seams and plates of  the
         tank wal1 and bottom;

    o    Possible   erosion   around   the   foundation,    pads,   and   secondary
         containment,  if any;  and

    o    Deterioration  of   protective  coatings  as  indicated   by  corrosion,
         blisters, discoloration, or film lifting.

    Visual    inspection,   picking,   scraping,    and  hammering  are   efficient
procedures  for  locating major  corroded  areas on  aboveground  portions of  the
tank.  Leak-testing devices,  such  as  ultrasonic or vacuum devices,  may be used
as aids to visual  inspection, if  necessary.   (See Section  10.8  of  this  text
for details on these  inspection devices.)

    Concrete   curbing   around   the   base  of   the   foundation   and  foundation
ringwalls  should  be  inspected  for  signs of  deterioration.  Cracks or  decay
should be  repaired promptly  to  maintain structural  integrity  and  to  prevent
liquids from  collecting under  the  tank.  Concrete  pads,  base rings,  piers,
column  legs,   stands,   and  any  other  general   support   structures   should  be
visually examined  for  cracks  and  spalling.   Such deterioration  can  also  be
uncovered by  scraping  the  suspected areas.   The joint between  the tank bottom
and the concrete pad  or base  ring  may have  a  seal  for stopping water seepage.
If so, this  should also be Inspected for corrosion.  Wooden supports for tanks
should be checked  for  rotting  by hammering.   Anchor bolts  can  also be checked
for  structural  integrity  and  tightness  by  hammering.   Excessive  foundation
settlement    is   typically   Indicated   by   distortion    of   anchor   bolts,

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                                             OSWEK Honey Directive No.  9483.00-1

                                        10-13

buckling of columns,  and  excessive concrete cracking.   Welds  along  the  angle
iron at  the  intersection  of the shell and  tank  bottom should  be inspected for
deterioration as well.  (See Figure 10-1.)

    Secondary  contain/nnet  structures,  including  liners,  vaults  and  double-
walled  tanks  or other  approved  structures should  be  regularly  inspected  for
signs  of  structural  integrity,  and  erosion  or  corrosion.    Many  of  the
guidelines followed  in  inspecting  concrete foundations as mentioned  above  can
be  applied  to  inspecting  concrete  vaults.    Be  particularly  careful   when
looking for cracks  as concrete vaults are  subject  to  cracking  when exposed to
freeze/thaw cycles.

    There are  particular  properties  associated with clay and polymeric  liners
that  the  inspector  should  be  aware  of when  conducting  an Inspection.   Clay
liners are subject to the following:

    (1)  drying and  cracking;

    (2)  leaching of components when  exposed to groundwater or  other solutions;

    (3)  ion   exchange when  exposed  to  water  containind  acids,  alkalis  or
         dissolved salts;  and

    (4)  destabi1iration when  exposed to some  organic solvants.

Polymeric liners are subject to:

    (1)  risk of puncture;

    (2)  damage from vehicular traffic;

    (3)  attack by sunlight  and ozone;

    (4)  attack  by  hydrocarbon solvents particularly  those with  high  aromatic
         content.

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10-14
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                                             OSWER Policy Directive  No.  9483.00-1

                                        10-15

                 10.4   INSPECTION OF CATHOOIC-PROTECTION  SYSTEMS

    Citation

    Sec.  264.195
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                                   10-16

A)   Cathodic-Protectlon  Systems.

Section  264.195(c)(1)   requires,   at   minimum,   that  an   inspection   be
conducted of the proper operation  of the cathodic-protection  system  within
six  months  of  initial  Installation  and annually  thereafter.  To  confirm
proper operation, the  system  and  component  checks  discussed below  should
be helpful.  Cathodic  systems  should  be checked for  electrical  continuity
and  for  failure which may  be  caused  by  broken wires,  broken  or  shorted
Insulators, or loss  of coatings.

Tank structure-to-soil potential measurements  should  be  conducted at least
annually by a  corrosion  expert  to ensure a  minimum  level  of -0.85  volts.
Tank  structure-to-soil   potential  measurements  are  usually performed  by
measuring the  voltage  between  the  tank or  piping  surface  and a  saturated
copper-copper  sulfate  reference   electrode   located  on  the  electrolytic
surface (joil)  as close as  possible to  the  storage  system.

A zinc reference  electrode,  or  a  test  station,  should  be   installed to a
depth  halfway  between  the top and  bottom  of the tank, and  midway  between
tanks,  if in a multiple-tank field.  This  installation  provides  convenient
test positions  to measure tank structure-to-soil  potentials.

If   the   structure-to-soil    potential    measurements   are   not   within
specifications, the  corrosion  expert   should  define  the corrective  action
to be taken.

B)   Inspection of Impressed-Current Systems.

As  a  particular  type  of  cathodic-protection  system,  Impressed-current
anodes are  usually  composed of  such  materials  as  graphite,  high-silicon
cast  iron,  platinum,  magnetite,  or   steel.   These  anodes   are  installed
either bare  or in  special  backfill  material.   They are  connected by  an
Insulated conductor, either  singly or  in groups, to  the  positive terminal
of  a  direct  current  source.   They are  dynamic  systems  requiring  close
supervision and maintenance oversight.

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                                         OSWER Policy Directive No.  9483.00-1

                                    10-17

Impressed-current electrode systems require  inspection  to  detect  potential
malfunction  from  power   interruption,  Improper  operation of  rectifiers,
damage to  insulation,  deterioration of  anodes,  bonding discontinuity,  or
broken wires.   One  simple,  necessary  inspection that may  be  conducted  by
operating personnel  is to check  monthly,  or more often, the  timing device
that  controls  the rectifier  to  make sure  that  there  has  been  continuous
output  from  the  impressed-current  system.   Rectifier  output   must  be
monitored bimonthly  with a  voltage or  amperage  indicator  and  adjusted  as
needed.  The readings may be taken by trained operating  personnel,  but any
adjustments  should  be made  by  a manufacturer's  representative.   Internal
connections  should  be  checked for  mechanical  security, and  structure-to-
soil  potential  measurements  should  be  made   annually  to  determine  if
rectifier   adjustments    are   needed   to    maintain   adequate   corrosion
protection.   These  tests  should  be made by a manufacturer's representative
and not by operating personnel.

All   sources   of  impressed-current  systems   should  be   inspected   for
malfunction.   The  National  Association ' of  Corrosion  Engineers  (NACE)
stipulates  that  proper functioning  may  be  indicated  by current  output,  a
signal indicating  a  normal  operating,  satisfactory electrical  state of the
protected  structure,  or  normal   power  consumption.    NACE  recommends  the
inspection  include:   checking  for  electrical  shorts,  ground  connection,
circuit resistance, and meter accuracy and  efficiency.   Isolating devices,
continuity  bonds,  and   insulators  should  also  be   evaluated  by  on-site
inspection or by evaluating corrosion test data.  NACE  also recommends the
following:

— When  the structure being  protected  is  not  covered,  it  should  be
   examined  for   corrosion,  and,  If coated,  the  condition  of  the
   coating  should be assessed.
— The condition of  test  equipment for  obtaining electrical  values
   should be maintained and checked annually for accuracy.

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                                    10-18


 For  further   information  on  remedial   action  procedures  when  test   and

 inspection criteria  indicate that protection  is  no  longer  adequate,  see

 NACE Publications  RP-02-85,   "Control  of  External  Corrosion  of  Metallic

 Buried,   Partially  Buried,  or  Submerged   Liquid  Storage  Systems"   and

 RP-01-69  "Control   of   External  Corrosion   on  Underground  or  Submerged

 Metallic Piping Systems."


10.5 INSPECTION REQUIREMENTS BEFORE  FULL  SECONDARY CONTAINMENT IS PROVIDED


 Citation
 Sec.   264.193(1)   All  tank  systems,   until  such  time  as  secondary
 containment that meets the  requirements of  this  section is  provided,
 must  comply with the  following:

 (1)   For  non-enterable  underground  tanks,   a  leak  test  that  meets  the
      requirements of  Sec.  264.19(a) or  other tank  Integrity  method,  as
      approved  or required by  the  Regional Administrator, must be  conducted
    ~at least  annually.
 (2)   For other than non-enterable underground  tanks, the owner  or operator
      must either (1)  conduct a leak  test as  in  paragraph (iXD  or  U1)  of
      this  section  develop  a  schedule  and  procedure  for  an  assessment  of
      the overall  condition  of the  tank  system by  an independent,  qualified
      registered professional engineer.   The  schedule and procedure must  be
      adequate   to detect  obvious cracks,  leaks,  and  corrosion  or  erosion
      that may  lead to cracks  and  leaks.   The owner or  operator  must remove
      the stored waste  from  the tank,  if neccessary,  to  allow the  condition
      of all internal   tank  surfaces  to  be  assessed.  The frequency of these
      assessments must  be  based on  the material  of construction  of  the  tank
      and  its   ancillary  equipment,  the  age of  the  system, the  type  of
      corrosion  or  erosion  protection   used,  the  rate  of  corrosion  or
      erosion   observed   during   the   previous   Inspection,    and   the
      characteristics  of  the  waste  being stored  or treated.
 (3)   For ancillary equipment, a leak test or other integrity assessment  as
      approved   by the  Regional  Administrator must be   conducted  at  least
      annually.
 (4)   The owner or operator  must maintain on  file  at  the facility  a record
      of  the  results  of  the  assessments   conducted  in  accordance  with
      paragraphs (1)(1) through (i)(3) of this section.
 (5)   If a  tank  system or component  Is  found  to be  leaking  or unfit for use
      as  a  result  of  the  leak test or assessment  in  paragraphs  (i)(l)
      through  
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                                             OSHER Policy Directive No.  9433.00-1

                                        10-19

    Guidance

    The EPA  believes  that  it is important to assess the integrity of hazardous
waste tank systems during the phase-in of  secondary containment.   Accordingly,
temporary  Inspection  procedures have  been  defined in Sec.  264.193(i)  for all
tank,  systems  until  secondary  containment  can  be  provided.   The  regulations
require  that  periodic   integrity   assessments   be  conducted  for  all  such
hazardous  waste   tank  systems  .    For  non-enterable  underground  tanks,  the
regulations require a  leak  test that meets the  requirements of Sec. 264.191(a)
or  other   tank  integrity method,  as  approved   or  required   by  the  Regional
Administrator, which must be conducted at least annually.  Ancillary equipment
must likewise have an  annual leak test or integrity assessment.

    A schedule and  procedure must  be  developed  during the  permitting  process
for   assessing    the   overall   condition  for   permitted  tanks   other  than
non-enterable- underground  tanks.    An  internal   inspection  or  other  tank
integrity  examination  that  addresses  cracks,  leaks,  corrosion,  and  erosion
must  be performed  at   least  annually  for  tanks  other  than   non-enterable
underground  tanks.   CSee Section 4.0 for further  details on assessment  of a
tank systems integrity.]

    The EPA  is currently investigating  tank  tightness testing  techniques and
may provide  additional   guidance on  the testing of non-enterable  tanks  in the
future.   For  other than non-enterable  underground  tanks,  the  guidance  for
inspection  is covered  in  this section.

    For  additional  guidance  in assessing  the  overall  condition of the  tank
system,   the  American  Petroleum  Institute's  (API)   Publication   Guide   for
Inspection  of  Refinery Equipment,  Chapter XIII,  "Atmospheric  and Low-Pressure
Storage  Tanks,"   4th   Edition,   1981,  may  be  used,   where  applicable,  as
guidelines  for assessing the overall  condition  of  the  tank system.  (Refer to
Table 10-1  for inspection requirements that are required  before  full  secondary
containment is provided.)

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                                             OSHER Policy Directive  No.  9483.00-1

                                       10-20

                 10.6  FIBERGLASS-REINFORCED PLASTIC (FRP) TANKS

    Corrosion  is  the major  cause  of  failure   in  metal  tanks.   FRP  tanks,
however,  are  more  likely  to  fall  due  to 'reaction, "softening, swelling,  or
cracking than from corrosion.

    Aboveground reinforced plastic tanks  should  be  Inspected for cracking  due
to  bending,  curving,  or flexing  after  delivery  and throughout  the  service  of
the  tank.   Excess  pressure  can  result   in  structural  failure,  evidenced  by
interior longitudinal cracking  in horizontal  tanks  and  by  vertical  cracking  in
vertical tanks.  The dye-penetrant testing  method can  be  used  to  investigate
suspected cracks.

    As  for  all  tanks,   the  metal  appurtenances  of  a fiberglass or  epoxy  tank
should  be  inspected according  to  the  same  schedule  as  discussed  in  Sec.
264.195  ("Inspections").   These metal parts  may corrode  or break  and  must  be
inspected.

                              10.7  CONCRETE TANKS

    Leakage  control  is  of major  importance  in  such  tanks.   The  following
factors may cause concrete tanks to  leak:

    o    Concrete permeability which  allows the  passage  of  water;
    o    Concrete cracks;
    o    Construction joint cracks and defects;
    o    Chemical attack.

    Cracks in  concrete  do  not typically  lead to structural  failure.  However,
cracks  In  addition  to  voids  In  concrete structures can  induce leakage  in a
concrete tank.

    Cracks  in aboveground, onground  and  inground  tanks  can  be   detected  by
visual  Inspection.

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                                                   roncy  Directive  NO.

                                        10-21

    Extent of  cracking can  be  made more  obvious  by  spraying  the  tank  with
water.  When the overall surface has dried the cracks  will  be  more prominent.

    Temperature  changes   can   also  expand   and  contract  concrete  creating
stresses In the concrete,  possibly leading to cracking.

    Factors that affect the durability of concrete  Include:

    o    Freezing and thawing;
    o    Chemical attack;
    o    Abrasion;
    o    Corrosion  of reinforcement;
    o    Chemical reaction of concrete aggregate.

    For the purposes of inspection of hazardous waste concrete  tanks,  chemical
attack  is  th£  most prominent  of  the  mentioned effects.  All  others  can  be
prevented for the most part.

    In  summary:   when  conducting  inspections  and   determining   inspection
frequencies  for  concrete  tanks,  several  characteristics  of  concrete must  be
considered:

    o    Concrete is susceptible  to freeze-thaw  cracking  and  deterioration  if
         not properly air  entrained;

    o    If  not  made  with  sulfate-resistant  cement,   concrete  is  subject  to
         attack by  nearly  all sulfate salts;

    o    Concrete is susceptible  to attack  by many  chemicals  including  alum,
         chlorine,   ferric  chloride,  sodium   bisulpnate,  sulfuric  acid,  and
         sodium hydroxide; (most prevalent condition);

    o    Concrete may be permeable to some liquids.

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                                                   roiicy  uireceive  MO.  y4oj.uu-i

                                        10-22

    The  American   Concrete  Institute's  (ACI)   Manual  of  Concrete  Inspection
Includes  information  on   inspection   fundamentals,   testing   of   materials,
sampling, and Inspection  before,  during, and  after  construction.

             10.8  INSPECTION  TOOLS AND ELECTROMECHANICAL  EQUIPMENT

    When   visual    inspection   suggests   the   need   for  a   more   detailed
investigation, simple  hand  tools  may  be used  as  an  Initial  aid.   Scrapers,
diggers, or  flange  spreaders  are  often adequate for these  purposes.   Hammers,
mirrors, magnifiers,  magnets,  and  plumbing  tools  may also  be helpful.   When
the inspection indicates  that  more sophisticated equipment  is  needed to assess
a suspected  problem,  mechanical  measuring  tools or  electrical  devices may  be
used.     Mechanical   measuring   tools  include   measuring   tapes,   scal.es,
micrometers, calipers, and wire gauges.  Useful  devices include ultrasonic and
electromagnetic instruments, which  provide nondestructive  means of determining
wall thicknes-s.

    Chemical  examination  and  destructive  test  methods  may  be  employed,  as
well,   to evaluate  pe'formance  of  storage system components.   Destructive test
usually refers to cutting coupons  (small plate  sections)  out of  the  tank base
to  test  for  corrosion on  the  underside of the  tank  bottom.  Destructive tests
are most often used with  empty, aboveground tanks.   They are not  commonly used
with underground  tanks.

    The  selection  of a particular  test  method  depends on the type  of  tank  to
be  Inspected,  the  extent  of  the  inspection,  and  the  equipment  available.
Several of the most common,  advanced inspection  methods are described below.

    Penetrant dyes  are often  used to detect  surface cracks on the outside of a
tank  that  would  not  be  revealed  by  a  visual  inspection.   The  penetrant  is
applied  to  a cleaned and  dried surface  by either  brushing  or spraying.  After
a  few minutes of  contact,  a  chemical  developer  is  then sprayed  onto  the
surface  to  give  a  white  appearance when  dyed.  The  dye  stains  the developer
and reveals  the extent and  size of any defects.

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                                             OSHER Policy Directive No. 9483.00-1

                                        10-23

    The magnetic  particle method  is  also used  to define surface  cracks  on a
tank.   This  method  may  be  used  only  on  tanks  constructed  of  magnetic
materials.   The  tank surface  must be  carefully  cleaned.   Iron  particles  are
then  sprinkled  on  the  surface.   A  magnetic  field  is  imposed  near  the
particles, either  by  a  permanent magnet (especially if flammable materials are
stored nearby) or  an  electromagnetic  device.  The  iron  particles  then arrange
themselves along  surface cracks,  particularly  near the  ends  of  cracks.   The
magnetic field should be Imposed in two directions to ensure that  there  are no
cracks or  to identify two or more  cracks  running  In different directions.  No
Indication Is given about the depth of cracks using this method.

    The vacuum box  detects  air leaks  using an  open  box in  which the  lips of
the open  side are  covered  with  a sponge-rubber gasket, and the  opposite 'side
Is glass.  A vacuum gauge and air  siphon  connection  are installed  Inside  the
box.  The  seam of  a tank shell  is  first  wetted with a soap solution, then the
vacuum box is_ pressed tightly over the seam'.   The  foam-rubber gasket  forms a
seal, and  a  vacuum is achieved inside  the box  by the air siphon.  If any  leak
exists, bubbles will form inside the box and  can be seen through  the glass.

    Ultrasonic Instruments  can  be used  to   measure  a  tank's  thickness  and
determine  the  location,  size,  and nature of  defects.  These instruments can be
used while the tank is in operation,  as only  the  outside of the  tank needs to
be  connected  to  the  device.   Two   types   of  ultrasonic  instruments,  the
resonance  and  the  pulse  type,  are most  commonly used  for  tanks.   The  pulse
type utilizes  electric  pulses and transforms  them  into pulses  of  ultrasonic
waves.   The  waves  travel  through  metal  until  they  reach a  reflecting surface.
The waves  then are reflected back and converted to electrical  pulses that  show
up on a time-base line of an oscilloscope.  The instrument  is  calibrated using
a  material  of known  thickness;  therefore,   the  time  interval  between  pulses
corresponds  to a  certain thickness.

    Radiography is used to detect  flaws,  such as  cracks, and  voids,  in opaque
(solid)  materials.   Radiography   may  also  be  employed  in  determining  wall
thickness, product build-up, blockage, and the  condition of  Internal  equipment

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                                        10-24

like  trays,  valve parts,  and  thermowelIs.   The  radiographic  technique  uses
either X-rays  or gamma radiation.  The  X-ray  Is  produced  1n a tube  within  an
X-ray machine; the gamma ray is produced from a radioactive  material  contained
1n a smal1  capsule.

    Radiography  testing  can  only  be  conducted  by  qualified  radiographers.
Specific precautions must  be  taken  when there is  the  possibility of  exposure
to  X-rays  or gamma  rays.   Training and  experience  are required  to  correctly
Interpret the Images produced on radiographic film.

    Other radiation-type  Instruments,  such  as  portable gamma ray  instruments,
may  also  be used  to  study  materials  for  defects.    These  instruments  are
particularly adaptable  for  the  evaluation of piping and,  to a  lesser  extent,
vessel-wall  thicknesses.  As  mentioned,  considerable  experience  is required to
operate radiation-type Instruments proficiently and safely.

    Acoultlc  emissions  testing  employs piezoelectric  transducers to  monitor
the   acoustic   emissions   given  off   by  a . material  during   corrosion  or
dlsbonding.   Essentially,  this technique  involves "listening"  to detect  the
pressure of corrosion or other stressful situations In  a structure.

    Acoustic  emission  testing may  be  applied before  a structure  is  put into
use,  while  it is  in  use, or  after it  is  removed from service.   It  may  be
applied  to  the  entirety  of  a  structure or  to  an  individual   section   of  a
structure.    Testing   may   be  conducted  continuously  for  the   purpose  of
monitoring  the  structure  over  a  specified  time  period  to  determine  its
structural  or material.Integrity then.

    Acoustic emissions testing can be used for the following purposes:

    o    detection and location of flaws In structures
    o    leak detection and location
    o    corrosion detection and location
    o    real-time detection and location of flaws during welding operations

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                                             OSWER Policy Directive No.  9483.00-1

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    Acoustic  emissions   testing  .has   several   advantages,   and   as   already
mentioned,  it  has  numerous applications.  The test method  is  non-destructive,
lessening the  inconvenience/disruption  of  testing.   It  is  a  highly  sensitive
test  and  detects very  small  discontinuities.   Also,  H  is a  volumetric test,
so both surface and sub-surface discontinuities can  be  detected.

    This  testing method  has   several  disadvantages as   well.   Although  only
limited  access  to  the  item being  tested  is required,  access is  required  no
less.   This makes  testing of existing  underground   tanks  and  piping  quite
difficult.   Testing  requires  an  operator  with  a   high   degree  of  skill.
Acoustic  emissions  equipment   is  more  sophisticated  and more expensive  than
other  non-destructive  testing   equipment.    Testing   equipment  and  skilled
operators are not always readily available.*

                           10.9 REPORTING REQUIREMENTS

    Citation

    Sec.  264.195(d)   The owner or operator must document  in  the  operating
    record of the facility an inspection of those items in  paragraphs (a)
    through (c)  of this section.

    Guidance

    The EPA believes  it  is Important for owners  and operators of  tank  system
facilities  subject  to these  requirements  to  keep a permanent record of their
Inspections.  This  provides  documentation  of owner/operator  compliance  with
the required inspections of the rule.

                         10.10  SUMMARY OF MAJOR  POINTS

    The following questions highlight the Information  covered in  this  section
and should be used to assure the completeness  of  a Part B permit  application:
    Information excerpted  from  study conducted for EPA by  Jacobs  Engineering,
    "Acoustic Emission Testing," March 20,  1986.

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                                                      LM i Ci. c i Ve no .  i»**o J •
                                    10-26
o    Have schedules and  procedures  been  developed for  inspecting  overfill
     controls?

o    Have the following  items  been  inspected at  least  once  each operating
     day:

          the  aboveground  portions  of  the  tank  system  to  detect
          corrosion or leaking of waste?

          data   from   continuous   monitoring   and   leak-detection
          equipment?

          the  construction  materials  of  the  externally  accessible
          portion of the tank system?

         _the  construction  materials  of  the  externally  accessible
    ""     portion of the secondary containment system?

          the  area surrounding  the  tank   system and  its  secondary
          containment to detect erosion or  signs of leakage?

o    Has  the  owner or  operator  inspected  all  cathodic-protection systems
     at least as often as the following:

          within  six  months  of  Initial  Installation  and  annually
          thereafter, the  proper  operation  of all cathodic-protection
          systems?

          bimonthly,  (i.e., once  every  two months)  all  sources  of
          Impressed current?

o    For  non-enterable   underground  tanks,   If  secondary  containment that
     meets the  requirements of the  regulations has  not been provided, has

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                                             OSWER  Policy  Directive  No.  9483.00-1

                                       10-27

         a leak, test that  meets  the  requirements  of  Sec.  264.191(a) or  other
         tank   integrity   method  approved   or   required   by  the   Regional
         Administrator  been conducted  annually?

    o    For  other  than   non-enterable  underground  tanks,   has   an  approved
         procedure,  adequate  to  detect  obvious cracks,  leaks, and  corrosion
         and erosion,  been implemented on  an  approved  schedule?

    o    For ancillary  equipment,  has a  leak test  or other  assessment  been
         conducted annually?
In  addition,  see Appendix  A, "Completeness  Checklist,"  to verify  compliance
with the requirements of this section.

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                                            OSWER Policy Directive No.  9483.00-1

                                        11-1
                11.0   RESPONSE  TO  LEAKS OR SPILLS AND DISPOSITION
                     OF LEAKING OR UNFIT-FOR-USE TANK SYSTEMS
    If a leak or  spill  from a tank system  1s  detected  or if a  portion  or  all
of a  tank,  system  Is  found to be unfit-for-use, the response procedures In Sec.
264.196 must  be  implemented.   These  procedures apply  even  if  a  release  has
been  contained  by  a  tank  system's   secondary containment,  except  for  the
notification  and   report  requirements  of  Sec.  264.196(d).   The   response
procedures of  Sec.  264.196  differ  somewhat from  the  procedures for  releases
from tank systems  that have been granted technology-based variances by  the  EPA
Regional   Administrator   from   the    Sec.    264.193   secondary   containment
requirements.   The necessary response  procedures for leaking tank  systems that
have been granted technology-based  variances  are cited  in Sec.  264.193(g)(3-4)
and are elaborated upon In Section 8.1  of this  document.

    The specific  requirements  of  Sec.  264.196   are  intended  to  supplement  the
contingency plan  emergency response procedures required by 40  CFR Part 264,
                                             •
Subpart D.   The  contingency plan must  be submitted  by the owner  or operator of
a tank system as part  of a Part B permit application.

    Section  264.196   does   not  contain,  however,   explicit  corrective  action
requirements pertaining  to any environmental  contamination  that has  occurred
from  tank  system  leaks or  spills.  Once notified  that  there is or has  been  a
release  of hazardous  waste   into  the  environment, as  required  under  Sec.
264.196(d),  the  Regional   Administrator  may   require   particular   corrective
actions  under  RCRA Section 3004(u),  3008(h),  or  7003(a)  to  protect  human
health  or  the  environment.   The  EPA  1s  currently  developing a  number  of
general  technical  resource documents  on  corrective action  technologies  that
will  address  remediation  of environmental  contamination.   The  EPA Office  of
Underground  Storage   Tanks   is   developing  a  technical   resource   document
specifically on  underground  storage   tank  corrective  action technology  under
U.S. EPA Contract  No.  68-02-3995.

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                                        11-2

    A tank  system owner or  operator  Is also  required to notify  the  National
Response Center for  certain  "reportable  quantity"  releases  under  40 CFR  Part
302, which will  also satisfy  the  notification  requirement  of  Sec.  264.196(d).

    Citations

    Sec.  264.196   A  tank  system  or  secondary  containment  system from  which
    there has been a leak or  spill,  or  which  is unfit-for-use, must  be  removed
    from  service   immediately,  and  the owner or  operator   must  satisfy  the
    following requirements:
         (a) Cessation of Use;  prevent  flow or  addition of wastes
         (b) Removal of waste from tank system  or secondary containment systems
         (c) Containment of visible releases  to the  environment
         
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                                            OSWER Policy Directive Ho.  9483.00-1

                                        11-3

    The intent of Sec.  264.196  is  to supplement a facility's  contingency  plan
by minimizing the  immediate  effects  of a detected release or potential  release
from a tank system and preventing and containing any potential  future  releases
from  such  a system.   To  accomplish  these~goals,  the following  steps  must  be
undertaken  in a  timely manner  by a tank  system  owner  or operator when a  leak
or spill  is detected or anticipated:

    o    Immediately  cease  flow of waste  into the  tank system.  Isolate  any
         leaking tank  system component  from  the non-leaking  portions  of  the
         system.  At  this  time,  the  cause of the release  may  be apparent  from
         inspection of the system (Sec.  11.1.).

    o    Remove  any waste  that  may  leak from the tank  system  (from the  whole
         system   if  the  cause  or  location of  a release  is unknown)   and  any
         waste that has accumulated  in  the secondary  containment (Sec.  11.1.2).

    o    Contain any visible releases (Sec. 11.1.3).

    o    Decide  whet, er to  provide secondary  containment for the  tank  system,
         repair  the  tank  system, replace  the tank  system,  or  close  the  tank
         system  according to Sec. 254.197 (Sec.  11.1.4).

    o    Prior  to   placing   such  a  tank  system  into  use   again,   secondary
         containment  and/or  tank   system repairs   or  replacement  must   be
         implemented  (Sec.  11.1.4).   Major  repairs  must  be  certified by  an
         independent,    qualified,   registered   professional   engineer   (Sec.
         11.1.5).

    Required notifications and reports  to  the EPA of tank system releases,  as
per Sec.  264.196(d), are described  in Section  11.2 of this document.

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                                            OSWER  Policy  Directive  No.  9483.00-1

                                        11-4

                   11.1   RESPONSE  ACTIONS  FOR  LEAKS OR  SPILLS

                          11.1.1   Waste  Flow Stoppage.

    Citation

    Sec.   264.196   (a)  Cessation  of  Use;   prevent  flow  or  addition   of
    wastes.   The  owner  or  operator  must   immediately  stop  the  flow  of
    hazardous  waste  Into  the  tank system  or secondary containment  system
    and inspect  the system to  determine  the  cause  of  release.

    Guidance

    When  a release occurs or  is  anticipated,  the transfer  of hazardous  waste
to a  tank system  must  be immediately  stopped  as per Sec. 264.196(a).   Also,
the portion of  a   tank  system that is  leaking,  if known,  should  be  isolated
from  the  non-leaking parts "of  the system.   Such actions  will  limit, to  the
extent possible, the amount of  waste  that might  potentially  be released  from
the  tank  system.    Disconnect and  cap  all  open  pipe  ends,   except  for  vent
piping, when waste  flow is stopped.

    The  waste   stoppage  requirement  applies   to  leaks  or  spills   to  the
environment or  into a   secondary  containment  system.   Following  stoppage  of
waste flow, the tank system  and  its  secondary containment  must be  inspected
for  the  location  of leakage  or   spillage.  The  owner or operator  should also
seek to determine  the potential  cause  of a  release.   Persons  familiar  with  the
circumstances  of   the  release  should review  and assess  the details of  the
Incident  to determine why a  leak or spill  has  occurred.

                              11.1.2   Haste  Removal

    Citation

    Sec.   264.196   (b)  Removal of  waste from  tank  system  or  secondary
    containment  system.

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                                            OSHER Policy Directive No. 9483.00-1

                                        11-5
         If  the  release  was  from  the  tank  system,  the  owner/operator
         must,  within  24  hours  after  detection of  the  leak  or,   if  the
         owner/operator  demonstrates  that   it  is  not  possible,   at  the
         earliest  practicable  time,  remove  as  much of  the  waste as  is
         necessary  to  prevent further  release  of hazardous  waste to the
         environment  and  to  allow  inspection  and  repair   of  the  tank
         system to be performed.
    (2)  If the material  released  was  to a  secondary  containment  system,
         all  released  materials  must be  removed within  24 hours  or in as
         timely a  manner  as  is  possible to  prevent  harm to  human health
         and  the environment.

    Guidance
    In order  to  minimize  endangerment of human health  and  the environment and
to inspect and remedy any  damaged  tank system equipment that  might  be causing
or could  cause  a leak or spill, Sec. 264.196(b)  requires that as much waste as
is necessary  to  prevent further releases  to  the  environment be  removed  from
the  tank  system.  This  waste  must  be removed at  the  earliest  possible  time
within 24 hours  after detection of  tfve  release,  or  at the  earliest possible
time if the  owner  or operator  demonstrates to the permitting authority that 24
hours is too little a time.

    All  of  the  waste must be   removed  from the  portion  of  a  tank   system  in
which a   leak or  spill  has occurred  or  is   occurring.   Thus,   if   a  tank  is
leaking, all waste above that level  in the tank where the  leakage  has occurred
or might  occur  must  be  removed.  Similarly, leaking ancillary equipment (e.g.,
a valve)  must be  evacuated and isolated  so that  it  can  be  repaired.   Piping
may be flushed into a non-leaking tank.

    It may  be necessary  to remove  all  hazardous waste from  a  tank  system to
ensure the safety of personnel  inspecting and repairing  the  system.   If  a  tank
is to be  emptied  entirely, it  may  be necessary to use a special  pump to remove
the bottom few Inches of waste.  Vent  piping  should be  left open  to  allow the
tank  to  "breathe."   Explosion-proof  or  air-driven  pumps  should  be  used for
hazardous waste  removal  in  the presence  of  explosive  vapors.   When  pumping
waste,  pump  motors  and  suction  hoses  must   be  bonded to  a  tank   system  to
prevent electrostatic ignition  hazards.  All electrical  power  to a tank  system
must  be  shut off  following  waste  removal.   All   removed  sludge   and  "tank

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                                        11-7

are  immediate  actions,  not detailed  analytical-investigations,  whose  purpose-
is to minimize the need for more extensive corrective actions in the future.

     The  extent  of aboveground/onground/inground  spills  and  leaks  is  often
readily evident  and remedial  action plans  can  be  simple  and  straightforward.
When  surface  releases occur,  the  flow  must be stopped  promptly  and  the  waste
contained in an area where it can be recovered.  Safety  and  health precautions
must be used during all waste cleanup operations.

     The  sooner waste  recovery  starts,  in general,  the greater  the  quantity
that  will   be  recovered.   Efforts  should  be concentrated on  blocking  the
release flow path,  by closing off channels into open  catchbasins,  gutters, or
sloping  surfaces   leading  down  and  away  from the  release  site.   A  release
should  be  contained  as  quickly  as  possible  with  whatever  flow  barriers  are
available,  such as containment booms, clay mounds,  etc.

    After any  aboveground released  wastes  are contained,  it  must be  decided
whether to  collect them for  proper  disposal  by pumping or  by  absorbing  them.
Pollution control  contractors  and  suppliers 'can  provide  the  required  tanks
and/or absorbent  materials.

     In anticipation of possible aboveground spills,  an  owner or  operator  of a
tank system without secondary containment should stockpile an emergency supply
of absorbent pads,  containment boom sections, and  other response  material  that
may  prove useful  if  a  surface  spill or  leak occurs.   As required for  their
Part B  permits under  40 CFR  264 Sufaparts  C and D, all  TSO  treatment,  storage
and  disposal facilities  must  have emergency prevention  and  response  equipment
on-site for hazardous  waste releases.

    A  surface  release may  permeate  the soil  and necessitate both  surface  and
subsurface remedial efforts.   Surface  releases may  also migrate  to  manholes,
drain  lines,   basements,   wetlands,  or  other  low areas.   When  remedying  a
visible release,  the  owner  or  operator  should inspect  surrounding  streams,
waterways,   drainage   channels,  and  wetlands.   If  possible,  a  competent  spill
contractor  should be  hired  to prevent  waste  Incursion  into  these  areas.

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                                        11-8

Collection  ditches,   interception  trenches,  barrier  curtains,   or   plastic
sheeting  should  be  used  for  waste flow  containment.   (API publication  1628
describes  the  migration  of petroleum  products in  soil  and  ground water  and
suggests a number of  techniques for trapping and  recovering  moving liquids.)

    When  surface  soil  has  become  saturated  with  Ignitable liquids,  digging
must be  done  with  extreme  care to  avoid  any  sparks  that  can  Ignite  released
waste.   Equipment  should  operate slowly,  with  due regard  for the danger  of
explosion  in  areas with  explosive vapor  concentrations.   Special  rubber  tips
for  backhoe  shovel   teeth  and  other  types  of  non-sparking  equipment  are
available for protection against sparks.   In certain circumstances,  the  act of
moving   the   soil   may  ventilate   an  area  sufficiently   to  reduce   vapor
concentrations  below  explosive   limits,  allowing  movement  and  activity  to
proceed  safely.    Removed   soils   should  be  placed  in  box  trucks  or  1 i'ned
temporary  storage  areas.   Any  pools  of  liquid  wastes  in  the  soil should  be
removed promptly using pumps.

    For   visible   wastes   floating  on   surfa.ce  water,   specialized   pumping
equipment is available.  The  equipment required  depends  upon the  depth  of the
water,  the  amount  of  waste,  the  waste's  flow rate into the area,  and  safety
concerns.  Specially  designed  "skimmer"  pump systems are available  from spill
control contractors.

    A  holding tank  for collected  wastes  may be  useful   at  a  waste  cleanup
site.  When filled,  the tank  can be  trucked  off-site  for  final  disposition.
When small  volumes or slow recovery rates are involved,  a skid  tank or a small
heating-oil  tank  (approximately  275  gallons)  may  suffice.    For  high-volume
waste  cleanups,  tanks  of   up  to  4,000  gallons  may  be  needed.   The  pump-out
frequency of a holding tank influences how much on-site waste storage  capacity
Is  necessary.   Existing  non-leaking  tanks,  If they  are   compatible  with  the
released wastes, may be used  to  hold any recovered wastes.   A  tank truck also
may be moved on-site so that wastes canbe pumped  directly into  it.

    At  waste  cleanup  sites,  electrical  service  may be required  for pumps and
lighting.   If  ignitable  wastes  are  involved,  power  equipment  should  be

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                                            OSWER Policy Directive No. 9483.00-1

                                        11-9

explosion-proof.   Particular  care  must  be  taken  when  placing  electrical
machines  at  ground  level  because  explosive  vapors   heavier   than  air  may
accumulate  there.   Such  vapors  sink  to  the  ground  and travel  downhill  to
collect against any  barrier.   If gasoline-powered pumping units  are used, they
must be  located away  from any area  where explosive  vapors  may  be  generated.
Because  volatile  liquids  and vapor  concentrations may  pose  fire  hazards  if
they are  near  a source  of ignition, all  ignition sources  must be  kept away
from a cleanup site.

    To  protect  further  against  fire,   inhalation,  and other  hazards,  all
observation  wells,   sumps,  and   wells   should  be  covered   and  vent  piping
installed.  A  sump  or well diameter  should  only be large enough  to allow for
any necessary cleanup work.   When  pumps  are operating  in  wells,  the agita-tion
created will cause  vapors  to rise, and  lighter vapors may escape.  Large, open
holes exposing  a wide  area of volatile   liquids  should  be avoided  to minimize
vapor loss.  -

    Depending on  the  chemical nature of a visible, released  material,  it may
be appropriate to  identify and locate vapors and to determine vapor
concentrations with  a sampling device or  a vapor-monitoring device.*

    Several  references  are  available,  that address  protection  of  workers  at
hazardous waste facilities.  Two  examples are:

    1.    Levine and  Martin,  Protecting   Personnel  at  Hazardous  Haste  Sites
         (Boston,  Mass.:  Butterworth Publishers, 1985).
    2.    US  EPA,   Office  of  Emergency  and   Remedial   Response,   "Standard
         Operating Safety Guidelines" (1984).
    A  device  measuring  the  potential   for  explosion  is  essential  whenever
    potentially  flammable  or explosive  chemicals  have been  released.   Such a
    device identifies concentrations of  vapors  posing an explosive  potential,
    but  it  does not  indicate  toxic vapors  which  may occur  at  concentrations
    below the  lower explosive  limit.   For  toxic  organic  vapors, devices  are
    available to identify  concentrations  down  to below 1  ppm.  Using the EPA's
    Standard Operating Safety Guidelines,  organic  vapor  readings can  indicate
    appropriate levels of protection for response and cleanup personnel.

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                                       11-10


    In general,  work,  on tanks  should  never  take  place  if the wind may  carry

vapors into areas where they  could  be breathed by  unprotected  workers.


    Following  identification,  collection,   and  containment of  contamination,

Sec.  264.l96(c)   requires   proper  removal   and   disposal    of   contaminated

materials.   Thus,  all  recovered  wastes,   wastewaters,  and  any  contaminated

soils must be sent to a RCRA-permitted  hazardous waste  handling facility.


                    11.1.4   Repair, Replacement, or Closure.


    Citation


    Sec.   264.196(e)   Provision  of  secondary  containment,  repair,  or  closure.
    (1)   Unless  the  owner/operator satisfies  the  requirements  of  paragraphs
         (e)(2) through (4) of  this section,  the  tank  system  must be closed in
         accordance with Sec.  264.197.
    (2)   If  the  cause  of  the  release  was a  spill  that  has  not  damaged  the
       -integrity of  the system,  the  owner/operator  may return  the  system to
         service  as  soon as  the  released waste  is   removed  and  repairs,  if
         necessary, are made.
    (3)   If  the  cause of the release was  a leak  from the primary  tank  system
         into  the  secondary  containment system,  the   system  must  be  repaired
         prior to returning  the  tank system to service.
    (4)   If the  source of  the  release  was a  leak to  the  environment from  a
         component  of  a  tank   system   without   secondary   containment,  the
         owner/operator must  provide  the  component of the system from  which
         the  leak  occurred   with  secondary   containment  that  satisfies  the
         requirements  of Sec.  264.193  before  it   can  be  returned  to  service,
         unless  the  source  of  the leak is an aboveground portion of a  tank
         system  that  can   be  inspected  visually.    -If  the   source   is   an
         aboveground  component  that can be inspected  visually,  the component
         must  be  repaired  and may be  returned  to service  without  secondary
         containment  as  long as  the  requirements of paragraph  (f)  of  this
         section are satisfied.   If a  component is  replaced to  comply  with  the
         requirements  of  this  subparagraph,  that  component  must  satisfy  the
         requirements  for new tank systems or components in  Sees.  264.192  and
         264.193.  Additionally,  if a  leak has  occurred  in  any  portion of  a
         tank  system   component  that  Is  not readily accessible  for  visual
         Inspection (e.g.,  the  bottom of  an  inground  or  onground  tank),  the
         entire  component  must  be  provided  with  secondary  containment   in
         accordance with Sec.  264.193  prior to being returned  to use.

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                                            OSHER Policy Directive No.  9483.00-1

                                        11-11

    Guidance

    Following the  stoppage  of waste  flow,  the  removal  of waste  from a  tank
system,  and  initial  remedial  measures  for  visible  releases,  the  owner  or
operator will be  able  to assess  the  extent of the  tank system's damage.   At
this point,  the owner  or operator must either,  as required by Sec.  264.196
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                                        11-12


                                   TABLE 11-1


           SECTION  264.196 REQUIRED RESPONSES TO TANK SYSTEM RELEASES*
TYPE OF RELEASE
      REQUIRED ACTIONS
  CITATION
Spl11 with no damage
to tank system

Leak from tank system
to secondary containment

Aboveground leak from
tank system with no
secondary containment
Underground or Inacces-
sible leak from tank
system with no secondary
containment  -
Leak from secondary
containment
Leak from tank system
or secondary containment
requiring major repair
Remove released waste and
repair, If necessary.

Repair tank system.
Repair tank system and
implement visual inspection.
New components must meet
Sees. 264.192 and 264.193
requirements.

Repair tank system and install
secondary containment for the
entire component, as per Sec.
264.193 requirements.  New com-
ponents must meet Sees. 264.192
and 264.193 requirements.

Repair secondary containment.
New components must meet Sees.
264.192 and 264.193 requirements.

Repair tank system or secondary
containment as appropriate and
obtain certification of adequacy
from an independent, qualified,
registered professional engineer.
264.l96(e><2>


264.196(6X3)


264.196(6X4)
264.196(6X4)
264.196
264.196(e)(2-4)
     and
264.196(f)
        Closure of  a tank  system  under the  requirements  of  Sec.
        always an option if there has been  a release.
                                         264.197  is
NOTE:   If It  is  determined  that  a  tank system  release  could  threaten  human
        health or  the  environment  outside the facility either the EPA Regional
        Administrator  or  the  Na-tional  Response  Center  must  be  notified
        immediately.   (24-hour  toll  free number 800/424-8802)   CSec.  264.56 -
        Emergency  Procedures]   See  section  11.2  Required  Notifications  and
        Reports for Specifics.

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                                            OSHER Policy Directive No.  9483.00-1

                                        11-13

    Spi1 Is.  As long as a spill does  not  damage  a tank  system's  integrity via
chemical  corrosion or  other  means,  an owner or operator  may  return the system
to service after  the  released  waste  is cleaned  up.   Any necessary  equipment
repair must be  undertaken   daHy  inspection  protocol.

    Underground or  Inaccessible  Leaks  with  No  _Secondary  Containment.   Upon
finding a  leak  in  an  underground  or inacessible  (to visual  inspection)  portion
of a tank system,  the  owner or operator  must repair or replace  the  tank system
and  install   secondary containment  for the  entire  leaking  or  unfit-for-use
component.   For example, if a  leak  is detected  in the underground  piping  of  a
tank system,  all  the  underground piping of that tank system  must  be  equipped
with  secondary containment.   This  requirement  ensures  that  hazardous  waste
tank system components  presenting a substantial  risk  of release (i.e.,  because
they  are   Inaccessible  to regular  inspections)   are   provided  with  secondary
containment.    It Is not  considered  prudent to allow an Inaccessible portion of
a tank system  that  is  leaking  or  unfit-for-use to continue to operate  without
secondary containment  because other  similar leaks may  be imminent.

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                                        11-14

    Leak  from  Secondary  Containment.   It  is  especially  important  that  any
defect(s) in a  secondary  containment  system be repaired in  a  timely manner so
that any  potential  future  releases  from a tank system  does  not escape  to  the
environment.   Notification of  such  a release  from a secondary  containment
system must be  made to the  EPA Regional Administrator under  Sec.  264.196(d)
(see document  Section  11.2).    Under  40 CFR part  302.   A  release equal  to or
exceeding the reportable quantity  determined by the same part within  a  24-hour
period   must   be   Immediately  reported   to  the  National  Response   Center
(800-424-8802).

    Leak  from  Tank System  or  Secondary  Containment Requiring Major  Repair.
All of  the  applicable requirements of  Sec.  264.l96(e)  apply for this  type of
release  scenario,  in   addition  to  the  certification requirement  of  Sec.
264.196
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                                            OSWER Policy Directive No.  9483.00-1

                                        11-15

    Normally-, the  interior lining/coating procedure should be  considered only
for  newer  tanks  displaying  internal  corrosion  but  still  having  sufficient
plate  thickness  remaining  for  long  life.    Interior  lining/coating  does  not
prevent external'corrosion, nor-does it 'compensate for  the'loss of  tank system
strength caused  by thinning  of metal  walls.  Applicators generally  furnish a
warranty  against  tank,  failure  following   coating  for  up   to  12  years.
Applicators  reserve  the right,  however,  to examine a  tank's  internal surface
before  coating  and  to  refuse  service  to  any  tank   failing  to  meet  their
standards  of  tank-wall  integrity.   Further,   applicator  warranty  coverage
extends only to repairing  any damaged  coating and  does  not  include Incidental
damage, such as  that caused by spillage.

    Replacement   Considerations.    When  one   tank  system   in  a   group'  of
underground tanks is to be replaced, the condition  of other  nearby  underground
tank  systems  must  be   considered  because of  the  potential  for corrosion  of
other  tanks  eaused by  tank system replacement  (e.g.,  some  type  of  metal  or
composite,  to minimize  corrosion).   Whenever  feasible,  all tank systems in the
group (e.g.,  some type  of metal or composite,  to  minimize  corrosion)  should  be
replaced,  in  the  c-oup  if  the  tank  systems  are   of a  similar  age  and
construction and if they are  located  in a comparable environment.   There  is a
high  probability  that   the  other nearby  tank  systems  will  also  fail  if  they
have  a  similar  environment.   Replacement  underground  tanks   should  be  of
similar  design  and material  to one another, although  not necessarily  of the
same capacity.

    If  part  of  an  underground  tank  system   is  to  be  replaced,   several
considerations  are  important.   First,  new steel  In the  presence of  older steel
corrodes faster.   In the  electrochemical  activity of corrosion,  a  new surface
is  generally more active  (anodic)  than an  older  surface, which is  generally
coated with  a thin  rust or scale from  having been in  soil for a long period.
It  Is  not  uncommon  for new steel to corrode  and leak within  a  very  short time,
while older nearby steel tank systems remain  tight.

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                                        11-16
    Occasionally,   a  tank  system  Is replaced  by  one of  different design  and
material  (e.g.,  fiberglass  replacing   steel).   Unless  careful  attention  is
given to  the  method  of  installation,  serious  problems  can  arise.   For example,
if  a  fiberglass  tank is  not properly  supported  by shoring  or  some form  of
retaining  surface,  any  future   excavations   near   the   tank  could   cause  a
"rolling" effect,  with subsequent  major  damage to  the tank.  A  slight movement
could cause piping cracks,  from  which waste  could escape.   See  Section 6.0 for
more information on installation  procedures.


                     11-1-5  Certification of  Major  Repairs


    Citation
    Sec.  264.196(f)   Certification  of  major   repairs.    If  the  owner/
    operator has repaired a  tank  system in accordance with  paragraph  (e)
    of  this   section,   and. the   repair  has   been   extensive   (e.g.,
    installation of   an  internal  liner;  repair of  a  ruptured  primary
    containment or  secondary containment  vessel),  the  tank system  must
    not be  returned  to  service  unless the owner/operator has  obtained  a
    certification  by  an  Independent,  qual ified, registered,  professional
    engineer in  accordance  with Sec.  270.11(d) that the  repaired  system
    is  capable  of  handling  hazardous  wastes   without  release  for  the
    intended life of  the  system.   This certification  must  be submitted to
    the Regional Administrator within seven days after returning  the  tank
    system to use.
    [Note. -The   Regional  Administrator   may,    on   the    basis   of   any
    information received that there  is or has  been  a  release of hazardous
    waste or hazardous  constituents  into the  environment,  issue  an  order
    under RCRA  sections  3004(u), 3008(h),  or  7003(a)  requiring  corrective
    action or  such other response  as  deemed  necessary  to  protect  human
    health or the environment.]
    Guidance.
    Major repairs  of a tank  system  or  of a secondary containment  system must
be certified by  an  independent,  qualified,  registered, professional  engineer,
as required  by Sec.  264.196(f).   The  engineer must certify that  the  repaired
tank system  Is  capable  of handling  hazardous  waste without  releases for  the
Intended  remaining   life  of   the  tank   system.   Such  a  certification must  be
submitted to the  EPA Regional Administrator within seven days  after  returning
the tank system to use.

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                                            OSHER Policy Directive No. 9483.00-1
                                        11-17
    Examples  of -such  extensive repairs  include  installation  of  an  internal
liner because of internal corrosion, repairing a ruptured tank  and  fixing  torn
secondary  containment  liners  or cracked  concrete vaults.    Extensive  repairs
are generally  needed following  a  rupture or 'other  major  loss of  structural
integrity.  Major  losses  of  structural  Integrity may occur  under the following
conditions:  an accidential  puncture of a tank system component  by  a forklift;
a  catastrophic  event,  such  as  fire,  explosion, flood,  or  seismic  activity;  a
process malfunction,  such as overheating  or  over-pressurization;  or  improper
design  or  installation   including  seam-weld  breaks,  foundation   failure,  or
extensive  corrosion.  Certification  1s  not needed for routine  maintenance  and
repairs of  worn  tank system  components (e.g., valves, seals, pumps, instrument
adjustments, etc.).  A description  of qualified engineering  personnel  and  the
required  Sec.  270.11(d)   certification  is  contained in  Section  5.0  of  this
document.
                    11.2  REQUIRED NOTIFICATIONS AND REPORTS
Notification and Report

    There are no  required  notification or reporting procedures  when  a release
of  hazardous   waste   is   (1)   less  than  or   equal   to  one  pound  and  is
(2) immediately contained and cleaned up (264.194(d).   If the  release  does not
meet the above  criterion  and the quantity is less than its  reportable quantity
(as specified  in  40  CFR  302)   then  it must  be  reported to  the  EPA  Regional
Administrator within 24 hours of Its detection.
    Within 30 days  of  the detection of the  release  a  report must be submitted
to the Regional  Administration including the following:

         (1)   Most probable route of migration of the release.

         (2)   Characteristics of  the  soil  surrounding  the  release  including
              geology,  hydrogeology, soil  composition and climate.

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                                                  roiicy Directive  No.  94oJ.uG-i

                                       11-18

         (3)  If available, results of any  monitoring  or sampling,conducted  in
              connection  with  the  release.   If  this  sort  of  data  is  not
              available within the  30-day  report period, it must be  submitted
              to the Regional  Administrator  as  soon as  it is  available.

         (4)  Proximity of  release to  down-gradient  surface  water,  drinking
              water and population  areas.

         (5)  Description  of response actions  that have already been  taken  or
              are to take  place.

    If the  quantity  of a  release is equal  to  or  greater  than  its  reportable
quantity (as  indicated in 40 CFR  302)  then the National Response Center m.ust
be notified immediately (800/424-8802).
                          11.3  SUMMARY OF MAJOR POINTS
    This subsection summarizes the  immediate  response actions required  by  the
Sec. 264.196 regulations whenever  a  release is detected or  anticipated  from a
tank  system  that  has  not  been   granted  a  variance  from   the   secondary
containment  requirements.   These  response measures  supplement  those  described
in a facility's contingency plan,  required for the Part 8  permit  application,
and  must  be  performed  in  a  timely manner  upon detection  of an  actual  or
Imminent release:

    o    Was waste flow into the  tank system immediately stopped?

    o    Has  an  inspection  been   performed   for  immediately  after  release
         detection?

    o    Was waste  removal  from  the  leaking portion(s) of  the  tank  system and
         from  its  secondary containment  (if  applicable)  completed  within  24
         hours, while ensuring the  safety of personnel?

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                                            OSHER Policy Directive  No.  9483.00-1

                                        11-19
    o    Have immediate actions been  taken  to minimize the effects  of  visible
         releases?  (Such  actions  include containment, collection,  and  proper
         disposal,  while   employing  appropriate  worker   safety   precautions
         during cleanup activities.)

    o    Notification/reports

    o    Is It most appropriate to  repair,  replace,  or close  the  tank  system,
         based on the  extent of damage and the type of releases.

    o    Have the  indirect  effects  of tank  or  component  replacement  (e.g.,
         potentially  accelerated  corrosion  of  nearby underground tanks)  been
         considered in the decision  to replace?

    o    Has -a certification of adequacy  of major repairs  been received  from
         an Independent,  qualified,  registered professional  engineer?
In addition,  see Appendix A,  "Completeness Checklist,"  to verify  compliance
with the requirements of this section.

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                                             OSHER Policy Directive No. 9483.00-1

                                        12-1

                   12.0  CLOSURE AND POST-CLOSURE  REQUIREMENTS

    Citation

    Information on the  closure  and post-closure plan must  be  included In Part
B of the permit application as  stated in:

    Sec. 270.14(b)(13),  (15),  and (16)  copy of closure  and post-closure plans
    and cost estimates.

    Guidance

    The Intent  of  closure and  post-closure plan  requirements  for storage .tank.
systems,  as  delineated  in  Sec.  270.14(b)(13),  for  Part  B of  the  permit
application   is   to   supply   information   which   accurately   identifies   the
appropriate procedures  to close a storage/treatment tank system.   This section
provides^  guidance  on   decontamination  and   disposal   procedures,    technical
guidance on closure  and post-closure procedures,  and  information on  what must
be provided in the closure/post-closure plan and cost estimates for  the  Part B
permit  application.    Table  12-1  outlines  particular  responsibilities  for
owners and operators  under the closure/post-closure care regulations  for  tank
systems  falling  into  one  of  four  categories:   (A)  tank  systems  having
secondary  containment where  decontamination   or  removal J_s_  practicable;  (3)
tank,  systems  having  secondary  containment where  decontamination  or  removal  j_s
not  practicable;  (C)   tank   systems  without   secondary   containment   where
decontamination  or  removal  |_s  practicable;  and  (D)   tank  systems  without
secondary containment where decontamination or removal j_s not  practicable.   In
cases  where   tank  systems  are  not   provided   with   secondary  containment
(categories C and D), regardless of ability to decontaminate practicably,  they
must  fulfill  the  closure  care requirements   as  well  as  contingent  closure/
post-closure requirements.  (See the EPA's "RCRA Guidance Manual  for  Subpart G
Closure  and  Post-Closure Care   Standards  and  Subpart  H  Cost  Estimating
Requirements,"  available  In early '87,   for more  detailed  procedural  guidance
on  these  topics.)    This  document  provides   specific  procedural guidance  on
closure/ post-closure care  and  sample closure  and  post-closure plans.   Closure
and post-closure cost-estimate  worksheets are   in a separate  manual:  "Guidance

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                                             OSHER Policy Directive  No.  9483.00-1
                                        12-2



                                   Table 12-1

                       Closure/Post-Closure Requirements

                             (40 CFR  Subparts G & H)
                       Tank Systems Having
                       Secondary Containment
                             Tank System Hlthout
                             Secondary Containment
Decontamination or
Removal Is Practic-
able (owner/operator
plans to close as to
a tank)
Decontamination or
Removal Tj; not
Practicable (Tank
System must close
as a landfill)
    CATEGORY A

Closure Plan (§264.112)
Closure Activities
  (§264.111-115)
Cost Estimates for Closure
  (§264.142)
Financial Assurance for
  Closure (§264.143)

    CATEGORY B

Closure Care (§264.310)
  (Landfills)
Closure Activities as a.
  Landfill (§264.111-116)
Post-Closure Care
  (§264.310) (Landfills)
Closure Plan (§264.112)
  (Landfill)
Post-Closure Plan
  (§264.117)
  (§264.118)
  (§264.119)
  (§264.120)

Closure Cost Estimate
  (§264.142)
Post-Closure Cost Estimate
  (§264.144)
Financial Assurance for
  Closure (§264.143)
Financial Assurance for
  Post-Closure Care
  (§264.145)
        CATEGORY C

Closure Plan (§264.112)
Closure Activities
  (§264.111-115)
Contingent Plans
  (§264.197(c)
        CATEGORY D

Closure Care (§264.310)
  (Landfills)
Closure Care as a Landfill
  (§264.112-116)
Post-Closure Care
  (§264.310) (Landfills)

Cost Estimates for
  Closure (§264.142)
Financial Assurance for
  Closure (§264.143)
                                                     Post-Closure Plan
                                                       (§264.117)
                                                       (§264.118)
                                                       (§264.119)
                                                       (§264.120)

                                                     Post-Closure Cost Estimate
                                                       (§264.144)
                                                     Financial Assurance for
                                                       Post-Closure Care
                                                       (§264.145)
                                                     Contingent Plans
                                                       (§264.197(c))

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                                             OSWER Policy Directive  No.  9483.00-1


                                        12-3


Manual:  Cost  Estimates  for  Closure and Post-Closure Plans  (Subparts G & H),"

Volumes I through IV.


              12.1   DECONTAMINATION/REMOVAL  PROCEDURES FOR CLOSURE:
           WHERE DECONTAMINATION AND REMOVAL OF WASTES IS PRACTICABLE
                   AND  WHERE  SECONDARY CONTAINMENT  IS  PROVIDED

                                  (CATEGORY A)


    Citation


    Sec.  264.197(a)  states  that an  owner  or operator may  fulfill  closure

requirements for tank systems by demonstrating  that there has been:


    complete  removal  or  decontamination of all  waste  residues,  contaminated
    containment  system  components  (liners,  etc.),  contaminated  soils,  and
    structures and  equipment  contaminated  with waste and that these wastes are
    managed as hazardous  waste,  unless  Sec. 261.3(d) of this  chapter applies.
    The_closure   plan,   closure  activities,  cost  estimates  for   closure  and
    financial   responsibility   for   tank,   systems   must  meet   all    of   the
    requirements specified in 40 CFR Subparts G and H of this Part.


    Sec. 264.112(b)(4) of Subpart  G requires that  a  description  of procedures

for  removal   or  decontamination  of   all   hazardous   waste  residues   and

contaminated  containment  system  components  and  soils be  provided  in  the

closure plan.


    Those owners  and operators  who  have secondary  containment must remove all

residues  at closure and fulfill the  following additional   requirements  under
Subparts G and H:


    Closure Plan/Closure  Activities (§264.111).   [See Subsection 12.2  of this

document]


    Closure Activities (§264.111-115).   [See Subsection  12.2 of this document]


    Closure Cost Estimate (§264.142).   [See Subsection 12.5  of this  document]

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                                        12-4

    Financial Assurance for Closure  (§264.143).   [See  Subsection 12.6 of  this
document]

    If   it   is   not   possible  to   demonstrate   'clean  closure'   (complete
decontamination or removal of all residues) then  the unit  must be closed  as  a
landfill.

    Guidance

    Section  264.197(a) requires  the  owner  or  operator  to close the  entire  tank
system,  including  ancillary equipment  and  any  secondary  containment  systems
associated  with  the   system.   All   hazardous  waste,  contaminated  soil,  and
contaminated equipment components  must be  decontaminated or  removed  to  an
interim   status  or   permitted   hazardous   waste   disposal   facility.    Any
contaminated soil  or  contaminated  equipment  must  be  managed  as  hazardous
waste.   This -regulation  does  not define  the  level  of decontamination  that is
required.   The  EPA  is currently  developing  policy  on  the  broad  issue  of
defining acceptable levels of contamination outside  the scope  of this document.

    When  a  decision  is  made  to   discontinue  the  use  of  a  tank  system
permanently, closure may  be accomplished  by either abandoning  the  tank, system
in place or  by removing the entire tank system.

    The  closure  of a  tank,  system requires the  current owners or operators to
remove  or  decontaminate  all   residue  in   the  tank  system.   The  surrounding
soils,  structural  support  systems,  ancillary  equipment,  and containment system
components  must be  tested  to  indicate  the extent,  If any, of  contamination.
Any materials found  to be contaminated with hazardous  waste must be physically
removed from the tank  system area or decontaminated  following  approved methods.

    Information on procedures for cleaning  equipment and removing contaminated
soils,  methods  for sampling  and testing   surrounding  soils,  and criteria for
determining  the extent of decontamination  must be provided  in  the  closure  plan
and during  closure operations.

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                                             OSHER Policy Directive Mo.  9483.00-1

                                        12-5

    If a tank is removed from service due to leakage or  suspected  leakage,  the
owner/operator must meet  to  the requirements of Sec.  264.196(e)(2)<3)  and  (4)
("Response  to  and Disposition  of  Leaking or  Unfit-for-Use  Tank  Systems")  or
perform closure procedures  in  accordance -with Sec. 264.197.   If  the  following
requirements  are  satisfied  the system  may  be  returned  to   service  and  the
closure  requirements  will  not apply  until  final  closure of  the  facility  or
closure of the tank unit:

    (1)  If  the  cause  of the  release  (i.e.,  a  spill)  has  not   damaged  the
         Integrity of the  system  and the released waste is removed and  repairs
         are made; and

    (2)  If  the  release  was  a leak  from  a  primary  tank   system  into  the
         secondary containment system and the system was repaired;  and

    (3)  If the source  of release  was a leak from a component  of a tank system
         without  secondary  containment  and  that  component  is  provided  with
         secondary  containment before  being  returned to  use.    (See  Section
         11.0 for  further details  on this subject.)

    An unfit-for-use  tank system  must be  closed,  replaced,  or   repaired,  as
allowed,   and  any  leak  or  spill  must  be  promptly   remedied.   After  being
repaired and before reuse, an unfit-for-use tank system must be certified  by a
qualified,  registered,  independent professional  engineer  as  being  capable  of
handling  hazardous   wa-ste.    The   tank   system   must  also   have  secondary
containment installed under  any part of the tank system that has leaked and  is
either  underground  or  Inground because  the  leaking  portion  is   not  readily
accessible to visible inspection.

    A)   Recommended Decontamination Criteria.

    Decontamination is  a  highly critical task when permanently closing  a tank
    system.  Recommended decontamination criteria include:

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                                    12-6
     o    Cleaning operations  should be performed  under  the  supervision  of
          persons  who  understand  the  hazardous  potential  of  the   stored
          waste.

     o    Personnel  must be  sufficiently  trained  and  equipped to  perform
          the decontamination  operation  safely.

     o    Testing  to check  for complete  decontamination.

     o    Sludges  and  residues  should  be  removed from  the  area  near  the
          tank using "explosion  proof"  equipment,  such as  vacuum  pumps  and
          any other respiratory and safety equipment deemed appropriate.

     o    All contaminated  materials  removed from  the tank system  should
          be disposed  of  in  a  secure  hazardous  waste  treatment,  storage,
         .or  disposal  facility  that  has  interim  status  or  a  permit  to
          operate.

     o    Stubborn  residues   should  be  removed  by  pressure  hosing  with
          water,  steam cleaning, or solvent washes.

     o    Residues  from  cleanup  chemicals  (e.g.,  mineral  spirits  and
          kerosene) should  be  treated  or disposed of properly.

For further information on  tank decontamination procedures  see:

     o  "  (API)   Publication  2015,   "Cleaning   Petroleum   Storage  Tanks"
          (September 1985);

     o    NFPA No.  327,  "Standard  Procedures for Cleaning  or  Safeguarding
          Small Tanks and Containers"  (1982); and

     o    API  Publication  2015A, "A Guide for  Controlling  the Lead Hazard
          Associated with  Tank  Entry  and Cleaning  (Supplement  to  API  RP
          2015).

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                                         OSHER Policy Directive Ho.  9483.00-1

                                    12-7

The determination of  whether  to abandon a tank  in  place  or remove  it  for
reuse  or  disposal  depends  upon  several  factors,   such  as  the  age  and
condition  of  the tank,  its  salvage value,  and  its  potential  for  reuse.
Local laws  and -ordinances  may require  tank  system  removal.   Other  factors
that are important include:

Tank Location.  The depth at which the  tank is buried, the  type of  soil  in
which it  is  buried,  and overhead structures  nearby will  affect the ease or
ability  to remove  the  tank.   The  potential  for  damage   to  concrete  or
asphalt traffic surfaces and nearby utilities should also be considered.

Projected  Use  of  the  Site  After  Closure.   If  site  plans  call   for
development  that involves  excavation  or  regrading  to  the  level  of • the
tank, it is likely that the tank system will  have to be removed.

The  Cost-and  Availability of  Labor  and  Equipment.   Tank  system  removal
will require  the use  of heavy  equipment  and experienced  labor.    If  the
cost or  use  of this  labor  and  equipment  is prohibitive,  abandonment in
place may be the preferred option.

The Proximity of  Disposal  Sites.  The  proximity of  the  disposal  site  can
also greatly  affect  the cost of tank system removal.  Transportation costs
could be prohibitive, making abandonment in place the preferred option.

Regulatory Requirements.   Local  laws or ordinances may require  removal  of
the tank system as part of any permanent closure procedures.

Procedures  for  abandoning and/or  disposing  of  tank  systems  are addressed
in the following sections.

B)   Procedures for Abandoning Underground Tanks in Place (General).

Permanently  closed  tank  storage  or  treatment  systems  may  be  either
abandoned  in  place  or  removed  from  the   ground.   When  abandoning  an
underground tank in place:

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                                         OSHER Policy Directive No.  9483.00-1

                                    12-8

     o    Drain and flush the piping into the tank.

     o    Remove all  hazardous waste that can be pumped out.

     o    Dig down to the top of the tank.

     o    Remove  fill  drop  tube and  disconnect all fill, Inlet  and  gauge
          lines.  (Leave vent line  open until the tank is filled.)

     o    Cap all open ends  of lines that are not to be used  further.

     o    Fill the tank with water  until almost  overflowing,  remove excess
          waste  floating  on top and  empty  into  container for appropriate
          disposal.

     o   -After water has purged the tank,  several holes  should be  made in
          the  tank  top, and  the  water  should  be pumped out and properly
          disposed.
                                                  »
     o    Completely fill the tank  and any remaining  stubs completely with
          an  approved,  non-shrinking,   inert  solid  material  (e.g.  sand,
          gravel).

     o    Test for complete  decontamination.

     o    Disconnect and cap the vent line.

C)   Procedures  for  Abandoning Underground  Tanks  in  Place  (Sand-Pumping
     Method).

     o    Remove  all  hazardous  waste  from the tank and from all connecting
          1 Ines.

     o    Test for complete  decontamination.

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                                         OSWER Policy Directive No.  9483.00-1

                                    12-9

     o    Cut off  vent  lines  approximately three feet above  grade.   (This
          establishes an  increased  head on  sand being  pumped  into  the
          tank,  promoting complete  filling  of tank).  Do not  use a  cutting
          torch  if ignitable wastes are involved.

     o    Disconnect and cap extraction (suction)  lines.

     o    Make liquid-tight the threaded connections between  fill lines  of
          the tank  and  the discharge  line from  the sand pump.  On  tanks
          equipped with  fill  pipes  extending  below the  tank top,   remove
          the extension  piping within the tank.

     o    Attach a drain  hose  to the end of the vent line using a tight or
          threaded connection and  direct  it into a  reservoir to hold  any
          residual hazardous waste which might be left in the  tank.
    •
     o    Pump  sand  into  the  tank  until   a  dense  suspension of  sand  in
          water  discharges  from  the  vent lines.  (At this point, caps  may
          be  removed  from extraction lines for observation.)   Sand  should
          be prs;ent here before  the pumping is  stopped.

     o    Observe  caution  in  the  vent  line  area  due  to  the possible
          emission  of  flammable   or toxic  vapors.   If  necessary,  conduct
          vapors  to  a  remote  area  where  there will  be  no  hazard   to
          workers, the public,  or the environment.*
EPA  is   currently  in  the  process of  developing  regulations  under  RCRA
addressing  air  emissions  from  hazardous  waste  storage  and   treatment
tanks.  A proposed rule is expected to be published Fall  of '87.

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                                         OSHER Policy Directive No.  9483.00-1

                                    12-10

0)   Procedures for  Abandoning. .Qnqround,  Inground,  Aboveground  Tanks  in
     Place.

For  safety  reasons,  removal of  onground,  inground,  aboveground  tanks  may
or may not  be  a better option than abandonment  In  place.   It  should  also
be noted  that   local regulations  may  prohibit the abandonment  of  tanks  In
place.

     o    Remove  as  much   waste  as  possible from  the  tank  and  piping
          system.

     o    Disconnect and cap all  fill, gauge  and  vent lines.

     o    Free  the tank of all  flammable or toxic vapors.

     o    Remove all  sludge or other tank residues.

     o    Thoroughly  clean  the   inside  of  the   tank  (see  references  to
          standards for tank cleaning In (E)  of this Sub-section).

     o    Test  for complete decontamination.

     o    Secure entranceways  to  prevent  casual  or accidental entry  into
          tank.

     o    Anchor  tank  to  prevent  flotation  if  located in a  floodplain  by
          filling with Inert material  (i.e.,  sand, gravel).

E)   Procedures for Preparation for Removal and Disposal of Tanks.

Tanks  to  be disposed  of must be  rendered  free of  hazardous waste.   No
cutting torch  or other  flame  or  spark-producing  equipment  shall  be  used
until the tank  has been completely purged of  ignitable  vapors  or  otherwise
rendered   safe.    To   obtain  Information   on  safe  procedures  for  such
operations, refer to:

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                                         OSWER Policy Directive No.  9483.00-1

                                    12-11

     1)   (API)  Publication  2015,   "Cleaning   Petroleum   Storage   Tanks"
          (September 1985);

     2)   API 2015A, "A  Guide  for Controlling  the  Lead Hazard  Associated
          with Tank Entry and Cleaning" (1982);
     3)   API 20158,  "Cleaning  Open-Top  and  Covered Floating-Roof  Tanks"
          (1981);

     4)   National   Institute  of  Occupational  Safety  and   Health  (NIOSH),
          No. 80-106, "Working in Confined Spaces" (December 1979);  and

     5)   NFPA No.  327,  "Standard  Procedures  for Cleaning  or  Safeguarding
          Small Tanks and Containers" (1982).

Removed fiberglass-reinforced plastic  (FRP)  tanks may sometimes be  reused,
provided .that a  thorough  inspection  of  the  tank  has   been made  by  a
factory-approved agent  of the manufacturer  and  that the  manufacturer has
certified the tank as acceptable  for reuse.

The removal  of underground tank  systems must include procedures for:

     o    Removing all  liquid waste;

     o    Disconnecting and capping all plumbing and controls;

     o    Temporarily plugging all  tank  openings,  except  for a  1/8-inch
          hole for venting;

     o    Removing the tank from  the ground;

     o    Freeing the tank of all flammable or toxic vapors; and

     o    Transporting the tank  from the site.

If  the  tank  is to be disposed of,  a sufficient number of  holes  should be
made in it to  render  it  unfit for further  use.   This  discourages  possible

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                                    12-12

future use of it as a container for products  that would be  contaminated  by
residual   deposits  of  a  material  that  was   previously  stored   in   it.
(Sources   of  additional  information  on  the   disposal  of  storage   tanks
Include NFPA  30,  "Flammable  and  Combustible  Liquids Code"  (1984), and  API
Publication 1604, "Recommended Practice for Abandonment or  Removal of  Used
Underground Service Station Tanks" (1981)).

The  removal  of  aboveground,  j_nground  and  onground  tank  systems  must
include procedures for:

     o    Removing all liquid from the tank and piping  system;

     o    Disconnecting  and capping all fill,  gauge  and vent lines;

     o    Freeing the tank of all flammable or  toxic vapors;

   "o    Removing all sludge or other tank residues;

     o    Thoroughly cleaning the outside of the tank;

     o    Render it unfit-for-further use by puncturing holes  in  the walls
          of the tank; and

     o    Dismantling  the  tank  if  necessary  (tank dismantling  from  the
          outside  is  recommended to  limit  worker exposure  hazards).   For
          further  details  on  dismantling and  disposal  precautions in steel
          tanks, refer to API PSD-2202.
               12.2  CLOSURE PLAN AND CLOSURE ACTIVITIES:
                         THE PART 8 APPLICATION
Citation
Sec. 264.197(a).   The  closure  plan, closure activities, and cost estimates
for closure and financial responsibility for tank systems must  meet  all  of
the requirements specified in Subparts G and H of this part.

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                                             OSWER Policy Directive No.  9483.00-1

                                        12-13

    Applicable sections  in  Subparts  G and H  include Sec.  264.110-115 (closure
plan and  closure activities),  Sec.  264.142 (cost estimates for  closure),  and
Sec. 264.143 (financial assurance for closure).

    The closure  plan and  activities  will be  covered  in  this  section  of  the
document.

    Guidance

    Owners or operators  with  secondary  containment must submit,  as part of the
Part B permit application, a closure plan meeting  the  requirements  of subparts
G  and  H of Part 264.  If  however  the owners or operators  can demonstrate,  in
accordance  with  Sec.   264.197(b),   that  they  are  unable  to   remove   all
contaminated  soils  practicably they  must follow  landfill  closure/post-closure
procedures.  If  the  owners  or operators  have  not  prepared contingent  closure
and  post-clos-ure plans,   they must  revise  their  existing plan   in  accordance
with Subpart  G.   This scenario  is discussed  in   Sections  12.3   and  12.4  for
tanks  with and  without   secondary  containment.   Owners  or operators  without
secondary   containment  must  submit contigent  closure   and  post-closure  plans
with their Part B application.

    The closure  plan must  ensure that the general  closure performance standard
is  met C§264.111(a)]  such  that:   (1)   the  need  for  further  maintenance  is
minimized; and (2)  that  the stated procedures  control, minimize  or  eliminate,
to  the  extent  necessary  to  protect   human  health  and  the   environment,
post-closure  escape  of   hazardous waste,  hazardous  constituents,  leachate,
contaminated run-off, or  hazardous  waste decomposition products  to the  ground
or surface waters or to the atmosphere.

    The written  closure  plan  must  identify  steps necessary to perform  partial
and/or final closure of the facility and must include,  at  least:

    o    A  description of how  and when  the facility  will be  partially  and
         completely closed, including but not limited  to  methods  for  removing,
         transporting,  treating, storing  or  disposing  of  all  hazardous  wastes

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                                             OS*£8  Policy  Directive  No.  9483.00-1

                                       12-14

         and for  Identification  of  the   types  of  off-site  hazardous waste
         management  units to be  used;

    o    An  estimation   of  the  maximum  inventory  of hazardous  waste  stored
         on-site over the active life  of  the  facility;  <264.112<3»

    o    A detailed  description  of the steps  needed to remove or  decontaminate
         all  hazardous   waste  residues  and  contaminated  containment  system
         components, equipment,  structures and  soils  during  partial and final
         closure,   including  but   not   limited   to  procedures   for   cleaning
         equipment  and  removing  contaminated soils,  methods  for  sampling  and
         testing surrounding  soils, and  criteria  for  determining  the  extent of
         decontamination; <264.112(b><4»

    o    A  detailed  description  of  other  activities  necessary  to  prevent
         post-closure escape  of hazardous  wastes,  Including  but not limited to
         ground-water monitoring, leachate collection, and  run-on  and  run-off
         control; (264.112(b)(5))
                                     *        •

    o    A  schedule for closure  of each  hazardous waste management  unit  and
         for final  closure  of  the  facility, including at  a minimum,  (1)  the
         total  time  required  to  close each hazardous  waste  management unit  and
         (2) the time required  for intervening closure  activities  which will
         allow   tracking of   the  progress   of  partial  and  final   closure
         <264.112(b><6».

    o    An  estimate of the  expected year  of  final   closure  [for  facilities
         that  use   trust  funds   to  establish    financial   assurance only]
         <264.112(b)<7».

    Some of  the  important  areas to cover  In  the  closure  plan,  In  addition  to
those  mentioned  above,  are  the  following  circumstances,  which  may  lead  to
environmental hazards.  The closure plan  should  provide for  protection from:

    o    Leakage from deteriorated  tank systems;

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                                             OSHER Policy Directive  No.  9483.00-1

                                        12-15

    o    Accidental  intrusion  or tank  collapse during  subsequent  construction
         or excavation activities;

    o    Reuse of  abandoned  tank systems  without  meeting regulations or  using
         proper safeguards;

    o    Subsidence  of  the abandoned tank structure caused by  additional  tank
         deterioration,   which   may   create  hazards  to  nearby   personnel   and
         buildings; and

    o    Fire  or  explosion  hazards  caused  by  incomplete  waste  removal  or
         inadequate protective  measures.

    To  ensure  that  the potentially  damaging  situations  cited  above  do  not
develop,  all   tanks,  ancillary  equipment,  and  secondary  equipment  must  be
properly  closed.   Closure  procedures  may  be  based   on  either  temporary  or
permanent withdrawal  from  service,  each requiring specific  steps applicable to
the type1 of closure.

    Within 60  days  after final  closure, the owner  or  operator  must  submit  to
the Regional  Administrator by  registered  mail  a  certification that the  tank
system has been  closed  in  accordance with the  specifications   in the  approved
closure  plan.    If,   however,  the  tank  system  is  the  only   hazardous  waste
management  unit  being  closed  at  a  hazardous   waste  management  facility,
certification  is  not  required  until   final   facility  closure.    However  a
professional  engineer  may  not  be  able  to  certify proper  tank  closure  at  a
later date without  adequate  documentation.   Therefore, It might be  prudent to
have a  professional  engineer  certify tank closure  at  the  time  of  the  partial
closure even though it is not necessarily required.

                          12.3  CLOSURE OF TANK SYSTEM:
          WHEN  DECONTAMINATION  AND  REMOVAL OF WASTES IS  NOT PRACTICABLE
                   AND WHERE  SECONDARY CONTAINMENT  IS PROVIDED
                                  (CATEGORY 8)
    Citation

    Sec.  264.197(b).    If  the  owner  or  operator  demonstrates that  not  all
    contaminated   soils  can   be  practicably   removed  or  decontaminated  as

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                                        12-16

    required In  paragraph  (a)  of this section, then the owner or operator
    must  close   the   tank,  system  and  perform   post-closure   care   in
    accordance with  the closure  and  post-closure  care  requirements  that
    apply  to la'ndfills  (§264.310).    In  addition,  for  the  purposes  of
    closure,  post-closure  and  financial  responsibility,   such  a  tank
    system- is then considered to be a landfill, and  the  owner  or operator
    must meet all  of  the requirements for landfills specified in Subparts
    G and H of this Part.

    Guidance

    Upon closure,  the owner operator is required  to clean-up  all  equipment,
wastes and  soil  in accordance  with the approved closure plan.  If, however the
owner or operator can demonstrate that decontamination or removal  of  all  soils
is  not  practicable,  the owner/operator  must  then  close  as  a  landfill.   The
closure plan must  be  amended  and a  post-closure  plan,  and  post-closure  cost
estimate  must   be  prepared.    Financial  assurance  must   be   obtained  for
post-closure as  well.   (See  the EPA's  "Guidance  Manual:   Cost  Estimates  for
Closure and Post-Closure Plans (Subparts G & H)," Volumes I through IV.

    An impermeable  cap  over  the contaminated  area  will  reduce  the possibility
of  the  waste  in  the soil  migrating into  the  ground  water-.    In  addition,
Implementation   of  a  ground-water  monitoring   program   will   maximize  the
probability  that any  migrating  contamination  will be  detected  and  remedial
action  initiated  before  human  health  and  the  environment  are  adversely
affected during  the  post-closure  care period.   For  guidance on  ground-water
monitoring,   refer  to  "RCRA  Ground  Water  Monitoring  Technical  Enforcement
Guidance Document," U.S. Environmental Protection Agency (August 1985, Draft).

    In  summary,  the  landfill   closure  requirements  applicable  to  hazardous
waste storage tank systems are:

    o    A secure  final  cover  must be designed and constructed  to minimize the
         migration of wastes through  the dosed landfill;

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                                             OSWER Policy Directive  No.  9483.00-1

                                        12-17

    o    Cover  must  be  vegetated  to promote  drainage,  minimize erosion,  and
         accommodate settling and subsidence;

    o    Cover should be less permeable  than natural  subsoils  on the site;  and

    o    Cover should function with minimum maintenance.

    The secure landfill  must also follow post-closure regulations,  such  as:

    o    Survey plat submittal (§264.116);

    o    Maintain final  cover and cap integrity;

    o    Leak-detection  system;

    o    Maintain and monitor ground-water  monitoring system;
                                             •
    o    Maintain run-on and runoff control systems (to  prevent  erosion  of the
         cap); and

    o    Protect surveyed land benchmarks.

    As  indicated   in   Table   12-1   the  following  provisions   applicable  to
landfills must be complied with as well:

    Closure and Post-Closure Cost Estimates (Sees. 264.142  and  264.144).   (See
Sub-Section 12.5 of this section.)

    Financial   Assurance  for  Closure  and  Post-Closure  (Sees.  264.143   and
264.145).  (See Sub-Section 12.6 of this Section.)

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                                       12-18

                  12.4  CLOSURE AND-POST-CLOSURE  REQUIREMENTS:
             FOR  TANK  SYSTEMS THAT  00 NOT HAVE SECONDARY CONTAINMENT
                                (CATEGORY  C & D)

    Citation

    Sec. 264.197(c)   If  an  owner  or  operator has a  tank  system that  does  not
have secondary containment that  meets  the  requirements  under Sec.  264.193(5)
through  (f)  and  Is not  exempt from the  secondary containment requirements  in
accordance with Sec. 264.193(g),  then:

    (1)  The closure  plan  for  the  tank  system must  include  both a  plan
         for  complying   with   the  closure  plan  in  paragraph(a)  of  this
         section  and  a  contingent  plan  for  complying  with  post-closure
         care  in  accordance  with  the   closure  and  post-closure   care  '
         requirements  that apply to landfills.
    (2)  A  contingent  post-closure plan   for  requirements  that  apply  to
        _ landfills  must  be prepared and  submitted as part of the  permit
        "appl ication.

    Guidance

    As  indicated  in Table 12-1,  an owner  or operator of  a  tank system  that
does not  have  secondary  containment on the effective date  of the regulations,
regardless  of  the  practicability  of  removing  or  decontaminating  hazardous
residues,  must  prepare  two  closure plans and a post-closure plan.   The  first
plan must  comply with the total  removal/decontamination  requirements of  Sec.
264.197(a).   The  second  plan  must  comply  with  the  Sec.  264.197(b)  closure
contingency  requirements  for  landfills.    In  addition,  the owner or  operator
must prepare a contingent post-closure plan.  These  contingent  plans  would  be
used only If all  contaminated  residues  and  soils  could  not   be  practicably
removed  at closure.  The  objective of this  requirement  is to minimize  future
threats  to public  health and  the  environment caused  by undetected  leaks  from
facilities without  the protection of secondary containment.

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                                             OSWER Policy Directive Mo.  9483.00-1

                                        12-19

    Concerning closure activities  for  this  category the owner/operator  should
first  initiate  closure activities  for  "clean closure"  (§264.197(a))  tanks  if
feasible.  If the  owner  or operator  can demonstrate  that  "clean  closure"  is
not  feasible the  owner/operator   is  then   required  to  1)  decontaminate  and
remove the tank  and as much of the surrounding contaminated area  as  possible,
2)   perform   closure   activities   as  a  landfill,  3)   perform  post-closure
activities as a  landfill, and  4) continue financial  assurance  for post-closure.

    A  tank  system  that  receives  a variance  from secondary containment  under
Sec.  264.193(g)  of  the  regulations  is  not  required  to prepare  a contingent
closure  and  post-closure plan.   In granting  such  a  variance,  the EPA  would
have  previously  examined  the  tank  system's  design,  operation,  and  location
characteristics  and  determined that  hazardous waste  would not migrate  into
ground or surface water.

    A  tank  system  with  an  approved secondary  containment  system  will  not  be
required to  prepare  a  contingent  closure and  post-closure  plan.   However,  if
that  tank  system  has  evidenced  releases  of hazardous  waste,  and the  waste
cannot be removed  or  decontaminated at  closure,  then  that  tank  system  would
also  have   to  amend  its  closure  plan   and   prepare  a  post-closure  plan  in
accordance with  Sec. 264.197(b).   Similarily, if  there  is evidence of  leakage
from a  tank  system before  the  installation of  secondary containment,  the leak
would have  to  be  addre-ssed pursuant to  the  response  to  leaks  or spills  and
disposition  of  leaking or  unfit-for-use  tank systems  requirements in 40  CFR
264.196  (see Section  11.0  of  this  document for  further  details  on   this
subject.)   In  addition,  if  a  variance  has  been  granted  but  then  migration
occurs ciosure/post-closure requirements must be adhered to.
                    12.5   CLOSURE/POST-CLOSURE COST  ESTIMATES

    Citation
    Section  264.142(a).   The owner  or  operator must  have  a detailed  written
    estimate,  in  current  dollars,   of  the  cost  of  closing  the  facility  in

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                                             QSfctK Hoi icy Directive iio.  94eu.uO-l

                                        12-20

    accordance  with  the  requirements  in  §§264.111-  264.115  and  applicable
    closure requirements  in  §264.178,  §264.197,  §264.228,  §264.258,  §264.280,
    §264.310,  and §264.351. ...*
    Section  264.144(a).   The  owner   or   operator  of  a  disposal   surface
    Impoundment, land treatment, or  landfill  unit,  or  of a  surface impoundment
    or waste pile required under §§264.228  and 264.258 to prepare  a  contingent
    closure and  post-closure  plan must have a  detailed  written  estimate,  in
    current  dollars,  of  the  annual  cost   of  post-closure   monitoring  and
    maintenance of the  facility In accordance with  the applicable  post-closure
    regulations in §§264.117-120,  §264.228, §264.258,  §264.280  and  §264.310.**

    Guidance

    Cost  estimates  for  closure  and  post-closure  must  be   calculated   in
accordance  with   the   general  closure   and   post-closure   cost  estimating
requirements  in  Sees.   264.142  and 264.144,   as  Illustrated in  Table  12-1- of
this section.   All facilities  that store,  treat, or dispose of hazardous  waste
are required to prepare a closure cost estimate (Sec.  264.142).

    For owners  and  operators  of  tank  systems  having secondary  containment,
upon discovery  that  complete  removal  or decontamination of hazardous  waste .is
not practicable,  a  post-closure  cost  estimate  (§264.144) must  be  prepared.
For tank  systems  without secondary containment,  regardless of  whether removal
or decontamination is practicable,  contingent post-closure  costs  estimates  are
required.    The  owner   or   operator  must  also  revise  their  closure   cost
estimates.  These cost estimate requirements are summarized below.

    A)   Closure Cost Estimates.

    The owner  or operator  must prepare  a  closure cost  estimate  In  current
    dollars,  reflecting  the  cost  of  closure at the  point In  the  facility's
    operating  life when closure would be most  expensive,  as  Indicated by  the
    closure plan.  The  "worst-case" closure cost estimate should reflect
    For  our purposes  §264.197  (closure  of  tanks)  and  §264.310  (closure  of
    landfills) are of most concern.
    For our  purposes  §264.117-120 (general  post-closure care requirements) and
    §264.310 (closure and post-closure care of landfills) are of most concern.

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                                         OSHER Policy Directive No.  9483.00-1

                                    12-21

maximum anticipated  costs  for  each planned activity  in  the  closure  plan,
including:
o    Manpower;

o    Hiring a  third  party  to close the tank  system,  i.e.,  subcontractor's
     cost for  tank  system  removal, soil  excavation, and  decontamination of
     equipment and/or tanks;

o    Analytical work to determine the extent of soil contamination,  if any;

o    Transportation   and   disposal   of   contaminated    tanks,    piping,
     appurtenances, and soil;

o    Independent,  qualified,  registered  professional  engineer to  certify
     the closure activities; and

o    Any other closure activities.

The closure  cost estimate  should not include  salvage  value  that  may  be
realized  with  the  sale  of  hazardous   wastes,  facility  structures  or
equipment, land, or  other  assets  associated with the facility  at  the time
of  closure.   The owner  or operator  may  not  incorporate  a zero cost  for
hazardous  wastes   that  might  have  economic   value.   Cost  estimates,  in
addition,  must  be   updated  yearly  to  account  for  Inflation  (See  Sec.
264.142(b) for further details on  inflation adjustment requirements.   Also
see the  EPA's  "RCRA  Guidance Manual for  Subpart G Closure and Post-Closure
Care Standards and Subpart H Cost Estimating Requirements.")

During  the  active   life   of   the  facility   If   a  closure   plan  needs
modification,  a  request to  modify the closure plan must  be  submitted  to
the Regional Administrator.   If  a change in  a  plan increases the  cost  of
closure  then  the closure  cost  estimate  must  be updated no  later  than  30
days after Regional Administrator approval  of the modified closure plan.

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                                        12-22

    Closure  cost  estimates  should  be  prepared  In  tabufar   form,   clearly
    reflecting  the  closure  activities  and  their  costs.   [An  example  of  a
    closure cost  estimate  for  a  tank  system  can be found in  EPA's  "Guidance
    Manual Cost  Estimates  for  Closure and Post-Closure  Plans  (Subparts G  and
    H)" Volumes I through IV, available in early 1987.]

    B)   Post-Closure Estimate.

    In preparing  a  post-closure cost estimate, the owner or operator  must,  as
    with  the   closure  cost  estimate,  have  a detailed  written  estimate  In
    current  dollars  of   the   annual  cost  of  post-closure   monitoring  and
    maintenance   of  the   facility,   In   accordance   with   the   applicable
    post-closure regulations (Sees. 264.117-120 and 264.310).

    The post-closure cost  estimate must be based on  the  costs  to the  owner or
    operator of  hiring a  third party to  conduct  post-closure  activities.   It
    should be  calculated  by multiplying by the number of years  of post-closure
    care required times third-party hiring annual  costs.

    The post-closure  cost estimate  must  be adjusted  for Inflation (see  Sec.
    264.144(b)  of  40 CFR  for  details).  As  with the  closure  cost estimates,
    during  the active  life of the  facility  If  a  post-closure  plan  needs
    modification  a  request  to  modify the post-closure  plan must  be  submitted
    to the Regional  Administrator.   If a change in the  plan increases  the  cost
    of  post-closure  then,   the post-closure  cost  estimate  must  be  updated
    within  30  days  after  Regional  Administrator  approval  of  the  modified
    post-closure plan.

    For tank  systems without  secondary containment,  cost estimates calculated
    for  post-closure  care  must   reflect  the  costs  of  complying  with  the
    contingent post-closure plan.

Sample  worksheets  for   landfill   closure  and  post-closure  can  be  found  in
"Guidance Manual:  Cost Estimates for Closure  and Post-Closure  Plans  (Subparts
G and H)" Volumes I through IV.

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                                             OSWER  Policy  Directive  No.  9483.00-1

                                        12-23

                    12.6   FINANCIAL ASSURANCE FOR CLOSURE AND
                               POST-CLOSURE CARE

    A)   Financial  Assurance for  Closure Care.

    Under the 40 CFR  Subpart  H Closure/Post-Closure  requirements,  the  owner or
    operator  of  a   tank  system   subject  to  the   closure  cost   estimate
    requirements (Sec. 264.142)  must  establish  financial  assurance  for closure
    care in accordance with the approved closure plan  for  the facility  60  days
    prior  to  the  initial receipt of  hazardous waste.   (See  Sec.  264.143 of
    Subpart H  for further details.)

    B)   Financial  Assurance for  Post-Closure, Care.

    Section 264.145 requires the  owner or operator  of  a tank  system  subject to
    the  post-closure  cost  estimate  requirements  (Sec.  264.144)  to  establish
    financial  'assurance for post-closure  care  in accordance with the  approved
    post-closure p.lan for the  facility.  Owners or operators having  secondary
    containment  are not  required  to  have a  contingent  post-closure plan,  but
    if  they have demonstrated  the need  to  close  as  a landfill    they   must
    demonstrate  financial  assurance  for post-closure  care.

                          12.7  SUMMARY  OF MAJOR POINTS

    The  following   summarizes  the  information   covered   in  this  section  and
should be used to assure the completeness of a  Part B  permit application.

    For  a  tank  system  with  approved  secondary containment  on the  effective
date of the regulations:

    o    Have  the  removal  and/or decontamination  procedures  for  closure  been
         clearly described in  the closure plan?

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                                        12-24

    o    Has  the  fate  of  the  removed  or  decontaminated  tank  system  been
         described?

    o    Does the  closure  plan  address  complete removal  of the  tank system and
         contaminated soils In a logical manner?

    o    Has  an  appropriate  cost  estimate been  prepared  which  reflects  al1
         closure costs?

    o    If the  tank  system Is  to be abandoned in place, has  further use of or
         access to the tank been adequately prevented?

    o    If  removal   or  decontamination  of  all   contaminated   soils  is  not
         practicable following  final  closure  activities, have the requirements
         for  closure  and  post-closure  care   for  landfills  and  post-closure
         plans and cost estimates been fulfilled?

    For a  tank  system without approved secondary containment on  the effective
date of the regulations:

    o    Has a closure plan been developed which  satisfies  the  Sec.  264.197(a)
         requirements?

    o    Have  contingent  closure  and  post-closure  plans  and  cost  estimates
         been  developed  which  satisfy  Sec.  264.197
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                                            OSHER Policy Directive No.  9483.00-1


                                        13-1
              13.0   PROCEDURES  FOR  TANK  SYSTEMS  THAT  STORE OR  TREAT
                   IGNITABLE, REACTIVE,  OR  INCOMPATIBLE  HASTES
    Information  on  tank  system design  and  operating  procedures  for a  tank

system that  stores  or  treats Ignitable, reactive, or  Incompatible  wastes  must

be  Included  In  Part  B of  the  Resource Conservation  and  Recovery  Act  (RCRA)

permit application,  as specified in Sec. 270.16(j):


         For tank systems  in which  ignitable,  reactive, or  incompatible
         wastes  are  to  be  stored  or  treated,  a  description  of  how
         operating  procedures  and  tank  system  and  facility  design  will
         achieve  compliance   with  the   requirements   of   §264.198  and '
         §264.199.

    The requirements of  Sees.  264.198  and  264.199 were developed  to  minimize

the risks  from  storage  or  treatment of  these  special  types of  wastes.   Such

risks  irrclude fire,  gas and/or heat generation,  explosion,  etc.


             13.1  IGNITABLE  OR  REACTIVE WASTES, GENERAL PRECAUTIONS


    Citation


    Section  264.198 states  the  special  requirements  for ignitable or  reactive

wastes, which cannot be placed in a tank or its  ancillary equipment unless:


    (1)  The  waste   is   treated,  rendered  [inert],   or mixed  before  or
         Immediately  after   placement   in  the  tank   system  so  that  the
         resulting  waste,  mixture, or dissolved material no  longer meets
         the definition  of  Ignitable  or reactive  waste under  §261.21  or
         261.23 of this Chapter, and §264.17(b)  is complied  with;  or

    (2)  The waste  is stored or  treated  in  such  a  way that  It  Is pro-
         tected  from  any material  or conditions that may cause  the  waste
         to  Ignite or react; or

    (3)  The tank system is used solely for emergencies.

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                                            OSWtx Poncy Directive No. 943J.OO-1

                                        13-2

    Guidance

    A major factor  In the proper handling of hazardous waste  is  the  ability to
 classify  it  by  unique   physical  properties  or  general   characteristics,  as
 described In:

         §261.21, characteristic of ignitability;
         §261.23, characteristic of reactivity; and
         §264.17,  general  requirements for  ignitable,  reactive,  or
         incompatible wastes.
    Sections  261.21  and  261.23   should  be  used  to determine  if  the  waste
 exhibits  the   characteristics  of   ignitability   and  reactivity  under  this
 regulation  (see  Figure  13-1).    It   should  be  noted  that  this  regulation's
 definition  of  reactive  or Ignitable  substances differs  slightly  from the U.S.
 Department  of  Transportation  (DOT)  and  National  Fire  Protection Association
•(NFPA)  classifications.

    Section  264.17  details  some specific requirements for  handling  ignitable,
 reactive,  and   Incompatible wastes  (see Figure  13-2).  Section 264.17(a) deals
 with  control  of  ignition  sources.   Section  264.17(b)  requires   control  of
 chemical  reactions.  Section  264.17(c)  requires  documentation  of  compliance
 with the design and operating  precautions needed  for  the  entire  tank system to
 store and treat ignitable and  reactive wastes.

    When  a  facility  stores,   treats,  or  disposes  of  Ignitable  or reactive
 wastes, precautions must  be taken  1n  order to avoid one  or  more  of the follow-
 ing undesirable and dangerous  reaction consequences:

    1.   Heat  (or pressure) generation via chemical reaction.
    2.   Fire  produced  from extremely exothermic reactions or Ignition of
         reactive mixtures/products.
     3.    Innocuous   gas  generation  (e.g.,  C02,   ^)   that   can  cause
          pressurization and  subsequent  rupture of a  closed tank.
     4.    Toxic  gas  generation  (e.g.,  ^S,  HCN).

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                                            13-3

                                    FIGURE 13-1
                                                 OSWER Policy Directive  No. 9483.00-1
                                   40  CFR  261.21
                        CHARACTERISTIC  OF  IGNITABILITY
   (a) A solid wast* exhibits the charac-
  teristic of  IgnitabUlty If a representa-
  tive sample of the waste  has  any of
  the following properties:
   (1) It Is a liquid, other than an aque-
  ous  solution containing less than 24
  percent  alcohol  by volume  and  has
  flash point less than 60'C (HOT), as
  determined  by   a  Pensky-Martens
  Closed  Cup Tester,  using  the   test
  method  specified  In ASTM Standard
  D-93-79 or D-93-80 (incorporated  by
  reference, see 5 260.11).  or a Setaflash
  Closed  Cup  Tester,  using  the   test
  method  specified  In ASTM Standard
  D-3278-78  (incorporated by reference.
  see 1260.11), or as determined by an
  equivalent  test method approved  by
  the  Administrator under  procedures
  set forth In \\ 260.20 and 260.21.
   (2) It Is not a liquid and Is capable.
 under standard temperature and pres-
 sure, of causing fire  through friction.
 absorption of moisture or spontaneous
 chemical changes and, when Ignited.
 burns so vigorously  and persistently
 that it creates a hazard.
  (3) It is an  ignitable compressed gas
 as  defined In 49 CFR 173.300 and as
 determined by  the  test methods de-
 scribed in that regulation  or equiva-
 lent test methods approved  by the Ad-
 ministrator under 35 260.20 and 260.21.
  (4) It is an  oxidizer as defined in 49
 CFR 173.151.
  (b) A  solid  waste  that  exhibits the
 characteristic of Ignitability, but is nor
 listed  as a hazardous waste  In Subpart
 D,   has  the  EPA  Hazardous  Waste
 Number of D001.

 C45 FR 33119. May 19. 1980. w unended at
 4« FR 35247, July 7. 1981]
                                   40  CFR  261.23
                          CHARACTERISTIC OF  REACTIVITY
  (a) A solid waste exhibits the charac-
teristic of reactivity if a representative
sample of the waste has any of the fol-
lowing properties:
  (1) It is normally unstable and read-
ily undergoes  violent change without
detonating.
  (2) It reacts violently with water.
  (3)  It  forms  potentially  explosive
mixtures with  water.
  (4) When mixed with water, it gener-
ates toxic gases, vapors  or fumes in a
quantity sufficient to present a danger
to human health or the environment.
  (5) It is a cyanide or sulfide bearing
waste which, when exposed to pH con-
ditions between  2 and 12.5. can gener-
ate toxic gases,  vapors or fumes in a
quantity sufficient to present a danger
to human health or the environment.
  (6) It is capable of detonation or ex-
plosive reaction  if it  is subjected  to a
strong initiating  source or  if heated
under confinement.
  (7) It is readily capable of  detona-
tion  or explosive decomposition or re-
action  at standard temperature  and
pressure.
  (8) It is a forbidden explosive as de-
fined in  49 CFR 173.51, or a  Class A
explosive as defined in 49 CFH 173 53
or a  Class B explosive as defined in 49
CFR 173.88.
  (b) A  solid waste that exhibits the
characteristic of reactivity, but is not
listed as a hazardous •vaste in Subpart
D. has   the  EPA Hazardous  Waste
Number of D003.

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                                                OSWER  Policy  Directive No.  9483.00-1
                                           13-4

                                    FIGURE 13-2

                                  40 CFR  264.17
GENERAL  REQUIREMENTS  FOR  IGNITABLE, REACTIVE,  OR  INCOMPATIBLE WASTES
  (a) The owner or operator must take
precautions to prevent accidental igni-
tion or reaction of ignitable or reactive
waste. This waste must be separated
and protected from sources of ignition
or reaction including but not limited
to:  open flames, smoking, cutting and
welding, hot surfaces, frictional heat.
sparks (static, electrical, or mechani-
cal), spontaneous ignition  (e.g., from
heat-producing   chemical  reactions),
and radiant  heat. While ignitable or
reactive  waste  is being handled, the
owner or operator must confine smok-
Ing and open flame to specially desig-
nated locations. "No Smoking" signs
must  be conspicuously placed wherev-
er there is a hazard from ignitable or
reactive waste.
  (b)  Where specifically required by
other sections of this pan, the owner
or operator of  a facility  that  treats.
stores or disposes ignitable or reactive
wasTe. or mixes incompatible  waste or
incompatible wastes and other materi-
als, must take precautions to prevent
reactons which:
  (1) Generate  extreme heat or pres-
sure, fire or explosions, or violent reac- •
tions;
  (2) Produce uncontrolled toxic mists.
fumes,  dusts, or gases  in sufficient
Quantities to threaten human health
or the environment;
  (3) Produce uncontrolled  flammable
fumes or gases In sufficient quantities
to pose a risk of fire or explosions:
  (4) Damage the structural integrity
of the device or facility;
  (5)  Through   other  like  means
threaten human  health  or  the  envi-
ronment.
  (c) When  required  to  comply with
paragraph (a) or (b)  of  this section.
the owner or operator must document
that compliance.  This documentation
may be based on references to pub-
lished scientific or engineering litera-
ture, data from trial tests (e.g.. bench
scale or pilot scale tests), waste analy-
ses (as specified In { 264.13). or the re-
sults  of  the  treatment of  similar
wastes by similar treatment processes
and under  similar operating  condi-
tions.
(Approved  by the Office of Management
and Budget under  control  number 2050-
0012)
t« PR 2848, Jan. 12. 1981. as amended at 50
PR 4514. Jan.  31. 1985]

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                                            OSHER Policy Directive No.  9483.00-1

                                        13-5

    5.   Flammable gas generation (e.g., €2^,  H2>.
    6.   Explosion  resulting  from  a  vigorous   reaction  or  a  reaction
         producing sufficient  heat to  detonate  an  unstable  reactant  or
         reaction product.
    7.   Uncontrolled polymerization  producing extreme  heat  and  possibly
         flammable and toxic gases.
    8.   Solubilization of toxic substances (including metals).
    Dissipation of hazard  can be  achieved by ensuring  that  any  ignitable  or
reactive  waste  will   not  be  placed  In a  storage   tank,  unless  the waste  is
treated, mixed, or rendered  inert  prior to or  immediately after  placement  in
the  tank  system.   The   process  selected  to  alter  the ignitable or  reactive
characteristic(s) of  a  waste  must  be waste-specific.   Dilution,  ion-exchange,
and  precipitation  are examples  of acceptable practices for  rendering  a  waste
non-reactive.  The  specific process  used  to  alter  the ignitable or  reactive
characteristic(s)  of a  waste  must  be tested  and  validated  at bench  scale
before  i_t  is-applied at an  industrial  tank  facility.  Most  important,  if  a
waste Is mixed with  another material  (waste qr otherwise), the  mixed materials
must  be compatible.    The resulting  waste material,   following  treatment  or
mixing,  should no  longer fit the definition of ignitable or reactive waste,  as
specified  in  Sees.   261.21  and  261.23  or Sec.  264.17  (see   Figure   13-2).
Sections  264.17(a)  and  264.17(b)  are  equivalent,  in   essence,  to  Section
264.198(a)(2),  which  requires that  protective  measures  be  instituted  to ensure
that  any  storage and treatment  methods do  not  cause  the waste  to  ignite  or
react.  For  example,  a  tank system should  be  Isolated from  potential  sources
of  sparks, flames, lightning,  smoking,  etc.  This regulatory  section enables a
RCRA  incineration  facility  to  store   ignitable  wastes  1f  and  only  If  the
facility  is  designed and  operated  In a manner that assures  the  stored wastes
will have no possibility for Ignition.  Static sparks,  from liquid movement  in
a  tank  causing  an   accumulation   of  static  charge,  can  be  prevented  by:
avoiding  "splash-filling"  of  a tank;  limiting  the velocity  of an  incoming
waste stream into a  tank to  a  maximum 1 m/sec; eliminating extraneous  metal
objects  in   a  tank;  and  grounding  tank-fill  nozzles  to  the   tank   during
filling.  (Table  13-1  lists  references  with additional Information on  ignition
safeguards and fire prevention related  to tank storage).

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                                            OSrtfcR fo'n^y Directive  No.  9483.00-1


                                        13-6


                                   TABLE 13-1


                         IGNITION PREVENTION REFERENCES




Document Number	Title	Date	

API RP 20031            Protection Against Ignitions  Arising         1982
                        Out of Static,  Lightning and  Stray
                        Currents, Fourth Edition


NFPA 302                Flammable and Combustible Liquids Code       1984,
                                                                     1981,  1977


NFPA 70                 National  Electrical  Code                     1984   '


NFPA 77                 Recommended Practice on Static Electricity    1983


NFPA 78                 Lightning Protection Code        •            1983


NFPA SPP-1E             Fire Protection Guide on Hazardous           1984
                        Materials


1   American Petroleum Institute (API).

2   National Fire Protection Association (NFPA).

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                                            OSWER Policy Directive Ho. 9483.00-1

                                        13-7

    A tank,  system  may  be used temporarily  to  hold  ignitable or reactive waste
1n  an  emergency  situation,  in  accordance  with  Sec.  264.198(a)(3).   For
instance, if  there  is  a fire in one portion of a facility, ignitable waste may
have  to be  moved   temporarily  to  other  tanks  at  the  facility  during  this
emergency.   The temporary  storage  tanks  may  not  be  as  well  protected  from
lightning,  for  example,   as   the  tanks  near  the   fire,  but   under   the
circumstances,  the  temporary storage  tanks are still  more  protective  of the
waste  than   having  the   waste   remain  near  the  fire.    Similarly,   if  a
malfunctioning  pump  cannot  be  shut off, Ignitable  waste may be placed in other
tanks temporarily,  until the pumping  problem  is resolved and  the  waste  can be
removed to  the  proper  tanks.  An owner or  operator  must take care not to make
an  emergency  situation  worse  by  temporarily  placing   ignitable  or  reactive
waste in tank systems with a high probability of ignition or reaction.

          13.2  DISTANCE REQUIREMENTS FOR IGNITABLE OR REACTIVE HASTES

    Citation

    Protective  distance  requirements  for  the  storage of ignitable or reactive
wastes are specified in Sec. 264.198(b), which states:

         The  owner  or  operator  of a facility  where  ignitable  or reactive
         waste  is   stored   or  treated  in  a   tank  must  comply with  the
         requirements for the maintenance of  protective  distances  between
         the  waste  management  area and any public ways, streets,  alleys,
         or an adjoining property line that can be built upon  as required
         in  Tables  2-1  through  2-6  of  the National  Fire  Protection
         Association's  "Flammable and Combustible Liquids  Code,"  (1977 or
         1981)	

    Concerning  the  requirements  for the maintenance  of protective distances it
should be noted that the distance measurement should  be  taken  from the  area in
which the major quantity of hazardous waste  resides and this  is generally the
tank.   Therefore   in    fulfilling  the   protective  distance   requirements,
measurements  should be  based  on  the  distance from  the  actual  tank  to the
public way.

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                                            OSHER Policy Directive No.  9483.00-1

                                        13-8

    Guidance

    To store or  treat  1gn1table or reactive waste,  the  owner  or operator of a
facility  must  comply  with  protective  d-fstance  requirements  for  tanks,  as
specified  in  the  National  Fire  Protection  Association's   "Flammable  and
Combustible Liquids Code"  (NFPA 30).   The  principal  tank  siting  criteria  are
based on  tank,  contents,  the distance between tanks,  and  the spacing between a.
tank  and  a property  line  and/or  nearby  structures.   Restrictions  on  spacing
are generally based upon a fraction of a tank's  diameter.

    The NFPA's  classifications  for  tank  contents are  defined  in  Table  13-2.
These definitions  must be  applied when  using   NFPA  30  tank  siting  criteria
tables (Tables 13-3  through 13-8 in this document).   The NFPA definitions frave
to be compared to the 40 CFR 261.21  and 261.23  (Figure 13-1)  definitions  of
ignitables and  reactives.   For  example,  a  liquid waste with a  flash  point  of
95*F  .'35'C> 1* classified  as  an "ignitable" under the RCRA  regulations,  it  is
classified as a "flammable," not combustible, liquid by the NFPA.

    Concerning the  requirements for  the  maintenance of  protective distances,
it should be noted that the distance measurement should be taken  from  the area
in which  the  major  quantity of hazardous waste  resides,  and this is generally
the   tank  itself.    Therefore,   in   fulfilling   the   protective   distance
requirements,  measurements  should  be  based  on  the  distance  from  the  actual
tank to the public way.

    Types of tanks, protective measures, and minimum  distance  requirements  for
stable liquids  with operating  pressures  of 2.5 psig (17.24 kPa)  or less and
greater than  2.5 psig  are specified  in  Tables  13-3  and  13-4,  respectively.
The  NFPA  protective distance  requirements  for   boil-over  liquids  and  unstable
liquids are  listed in  Tables  13-5  and 13-6,  respectively.    Tables  13-7  and
13-8  determine  spacing  by tank  capacity.    Table 13-7  refers  to  Class IIIB
liquids,  which  are combustible  liquids with flash  points at  or  above  200°F
(93.4'C).   Table  13-8  is  a reference  table  for  use with Tables  13-3 through
13-6.

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                                            OSWER Policy Directive No. 9483.00-1


                                        13-9


                                   TABLE 13-2

             DEFINITION  AND CLASSIFICATION  FOR  TANK  CONTENTS  BY  NFPA
Definition of General Terms
    Liquid.  For  the  purpose  of this code, any material  which  has  a  fluidity
greater  than  that of  300 penetration  asphalt  when  tested  In  accordance with
ASTM  D-5-78,  Test  for  Penetration   for  Bituminous  Materials.    Hhen  not
otherwise   identified,   the  term   liquid  shall  mean   both   flawnable  and
combustible liquids.

    Flash  Point.   The  minimum  temperature  at  which  a  liquid  gives off  vapor
in  sufficient  concentration  to form  an  ignitable mixture  with air  near  the
surface  of the  liquid within  the  vessel  as  specified   by  appropriate  test
procedure  and apparatus as follows:

    The  flash  point  of a liquid having a  viscosity  less  than 45  SUS  at  100°F
(37.8'C)   and  a  flash  point  below  200"F  (93'C)   shall  be   determined  in
accordance  with  ASTM D-56-82,  Standard Method  of Test for  Flash  Point  by the
Tag Closed Tester.

    The flash-point of a liquid having  a viscosity of  45  SUS or  more  at  100°F
(37.8'Cf or  a  flash  point  of  200'F  (93°C) or higher  shall be  determined  in
accordance with ASTM  D-93-80,  Standard Method of  Test  for  Flash Point by  the
Pensky Martens  Closed Tester.

    As an  alternate,  ASTM D-3828-81,  Standard Methods  of  Tests  for Flash  Point
of Petroleum and  Petroleum Products  by Setaflash Closed  Tester,  may be  used
for testing aviation turbine fuels  within  the  scope of  this procedure.

    As an  alternate,  ASTM D-3278-82,  Standard Method of  Tests  for Flash  Point
of  Liquids by  Setaflash  Closed  Tester,   may  be used  for  paints,  enamels,
lacquers,  varnishes  and  related   products  and their  components  having  flash
points between  32°F (0"C)  and  230"F (1109C), and having a  viscosity  lower  than
150 stokes at 77'F (25'C).

    As an  alternate,  ASTM D-3828-79,  Standard Test Methods  for  Flash  Point  of
Liquids by Setaflash Closed Tester, may be  used for materials other  than  those
for which  specific Setaflash Methods  exist (cf., ASTM D-3243-77  for  aviation
turbine  fuels  and ASTM  D-3278-78   for  paints, enamels,   lacquers,  varnishes,
related products and their components.)
Source:  "NFPA 30:  Flammable and Combustible Liquids Code 1984."

Continued on next page.

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                                            OSHtR Policy Directive  No.  9483.00-1
                                       13-10
                              TABLE 13-2 Continued
Definition and Classification of Tank Contents
    Boll-Over.  An-event in  the  burning of  certain  oils  in an open top  tank
when, after a long period of  quiescent  burning,  there is a  sudden  Increase  in
fire  intensity  associated  with  expulsion   of  burning  oil  from  the  tank.
Boll-over occurs when the residues from surface  burning become more  dense  than
the  unburned  oil  and  sink  below  the surface  to  form  a  hot  layer  which
progresses downward much faster than the regression  of the  liquid  surface.

    When this  hot  layer,  called  a "heat wave,"  reaches  water or  water-in-oil
emulsion  In  the  bottom  of  the tank,  the   water  is first superheated,  and
subsequently boils almost  explosively,  overflowing  the tank.  Oils  subject  to
boil-over  must  have  components  having  a   wide  range  of  boiling  points,
including  both  light ends  and  a viscous  residue.   These characteristics  are
present in most crude oils and can be produced in synthetic mixtures.

    NOTE:  A  boil-over  is  an entirely different phenomenon from a slop-over or
froth-over.   Slop-over  Involves  a  minor frothing which occurs  when water  is
sprayed onto  the  hot surface  of a burning oil.  Froth-over  is  not  associated
with a fire but results  when-water  is  present or enters a tank  containing  hot
viscous oil. -Upon  mixing,  the  sudden  conversion  of water  to  steam causes  a
portion "of the tank contents to overflow.

    Combustible  Liquid.   A  liquid  having  a flash  point  at or  above  100°F
(37.8°C).

    Combustible Liquids  snail be subdivided as follows:

         Class II liquids  shall  Include those having  flash  points  at or above
         100°F (37.89C)  and below 130°F (60'C).

         Class  IIIA   liquids  shall   include  those  having  flash  points at  or
         above 130eF  (60'C) and below 200'F (93'C).

         Class  IIIB   liquids  shall   include  those  having  flash  points at  or
         above 200*F  (93'C).

    Flammable  Liquid.  A  liquid  having  a  flash point  below 100°F  (37.8'C)
and  having a vapor  pressure  not  exeeding  40 Ibs per  sq  in.  (absolute) (2,068
mm Hg) at  100'F (37.8*C) shall be known as a Class I liquid.

         Class I liquids shall be subdivided as follows:

         Class IA shall  Include  those having flash points  below  73"F (22.8'C)
         and having a boiling point below 100'F (37.8'C).

         Class IB shall  include  those having flash points  below  73°F (22.8'C)
         and having a boiling point at or above 100*F  (37.8*C).
Continued on next page.

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                                            OSWEk Policy Directive  No.  9483.00-1
                                       13-11
                              TABLE 13-2  Continued
         Class  1C  shall  include  those having
         (22.8'C) and below  100'F (37.8'C).
                                   flash points  at  or above  73"F
    Unstable  (Reactive)  Liquid.   A
commercially
condense,  or
temperature.
 produced  or
will become self-reactive
           liquid
transported will
            under
which  in  its  pure  state  or  as
vigorously polymerize,  decompose,
conditions of  shock, pressure,  or

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                                            OSWER Policy Directive No.  9483.00-1
                                       13-12


                                   TABLE  13-3

               STABLE  LIQUIDS—OPERATING PRESSURE 2.5 PSIG or LESS
Type of Tank   Protection
               Minimum Distance  in  Feet
               from Property  Line Which
               Is  or Can  Be Built Upon,
               Including  the  Opposite
                Side of a Public Way,
                and Shall Not Be Less
                     Than 5 Feet
                        Minimum  Distance  in  Feet
                        from  Nearest  Side of Any
                            Public  Way or  from
                            Nearest  Important
                           BuiIding  on the Same
                        Property and  Shall Not  Be
                            Less Than 5 Feet
Floating      Protection     1/2 times diameter of
Roofl          for Exposure^  tank
              None
               Diameter of tank  but
               need not exceed  175 ft.
                                        1/2  times  diameter  of
                                        tank
                         1/2  times
                         tank
          diameter  of
Vertical      Approved foam  1/2 times diameter of
with Weak     or inerting    tank
Roof to       system4 on
Shell Seam^  -tanks not
        ~      exceeding
              150 ft. in
              diameter^

              Protection     Diameter of tank
              for Exposures^
              None
               2 times diameter of
               tank but need not
               exceed 350 ft.
                                        1/2  times  diameter of
                                        tank
                         1/2  times  diameter  of
                         tank

                         1/2  times  diameter  of
                         tank
Horizontal
and Vertical
with Emer-
gency Relief
Venting to
Limit Pres-
sures to
2.5 psig
Approved
i nerti ng
system4 on
the tank or
approved
foam system
on vertical
tanks

Protection
for Exposures^

None
1/2 times Table 13-7
1/2 times Table 13-7
                             Table 13-7
                             2 times Table 13-7
                         Table 13-7


                         Table 13-7
Footnotes and source on following page.

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                                            OSHER Policy Directive No. 9483.00-1


                                        13-13


                              TABLE 13-3 Continued
1    Aboveground tank which  incorporates  either:   (1)  a pontoon or  double deck
    metal  floating  roof in  an  open top  tank in accordance with  API  Standard
    650; or (2) a fixed metal roof  with  ventilation  at the top and  roof eaves
    in  accordance  with API  Standard  650 and containing a metal  floating roof
    or  cover  meeting   the  requirements  of  (1)  or  a  metal   floating  cover
    supported  by  liguid-tight  metal  pontoons or floats  capable  of  providing
    sufficient  buoyancy to  prevent sinking  of  the  cover when  half  of  the
    pontoons or floats  are punctured.

2   Fire protection for  structure  on  property adjacent to liquid  storage shall
    be  acceptable  when located:   (1)  within  the  jurisdiction of any  public
    fire department; or (2)  adjacent  to plants  having private  fire  brigades
    capable  of providing  cooling  water  streams  on   structures  on  property
    adjacent to liquid  storage.

3   Aboveground  storage tank  with some  form of construction or device that
    will relieve  excessive internal pressure  caused  by  fires.   Construction
    shalj  talce  the  form of  a weak roof-to-shelf seam  to fail  preferential  to
    any other seam.

4   See NFPA 69, Explosion Prevention  Systems.

5   For tanks  over  150  feet  in diameter,  use  "Protection for Exposures"  or
    "None"  as applicable.

SOURCE:  Table 2-i,  "(NFPA) 30:   Flammable and Combustible Liquids Code 1984."

SI Units:   1 foot = 0.30 meters.

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                                            OSHER Policy Directive No.  9483.00-1


                                        13-14


                                   TABLE 13-4

            STABLE LIQUIDS—OPERATING PRESSURE  GREATER THAN 2.5 PSIG
Type of Tank   Protection
               Minimum Distance  in Feet
               from Property Line  Which
               Is or Can Be  Built  Upon,
               Including the Opposite
                Side of a Public Hay
 Minimum  Distance  in  Feet
 from  Nearest  Side of Any
    Public  Hay or  from
    Nearest Important
   Building on the Same
	Property	
ANY TYPE
Protection     1-1/2 times  Table  13-7
for            but shall  not be  less
Exposures1     than 25 feet

None           3 times Table 13-7 but
               shal1 not  be less  than
               50 feet
 1-1/2  times  Table  13-7
 but  shall  not  be  less
 than 25  feet

 1-1/2  times  Table  13-7
 but  shal1  not  be  less
 than 25  feet
1    Fire  protection  for  structures  on  property  adjacent  to  liquid  storage
    shall  be  acceptable  when  located:   <1)  within  the  jurisdiction  of  any
    publjc  fire  department; or   (2)  adjacent  to  plants  having  private  fire
    brigades  capable  of  providing  cooling  water  streams  on  structures  on
    property adjacent to liquid storage.

SOURCE:  Table 2-2, "(NFPA)  30:  Flammable and Combustible Liquids  Code  1984."

SI Units:  1 ft.  = 0.30 m.

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                                            OSWER Policy Directive No.  9483.00-1
                                        13-15


                                   TABLE 13-5

                                BOIL-OVER  LIQUIDS
Type of Tank   Protection
                   Minimum Distance in
                 Feet from Property Line

                   Which is or Can Be
                 Built Upon, Including

                 the Opposite Side of a
                   Public Way and  Shall
                Not be Less than  5 Feet
                            Minimum Distance  in
                           Feet from Nearest Side

                            of Any Public Way or
                           from Nearest Important

                            Building on the Same
                          Same Property and Shall
                          Not  be Less  than 5 Feet
Floating
Roof1
Fixed Roof
 Protection      1/2 times  diameter of
 for Exposure2  tank
              None
 Approved Foam
 Or Inerting
"System^
                 Diameter of tank
Diameter of tank
              Protection      1/2 times diameter of
              for Exposure2  tank
              None
                 Diameter  of tank
1/6 times diameter of
tank

1/6 times diameter of
tank

1/3 times diameter
of tank
                          2/3 times  diameter of
                          tank

                          2/3 times  diameter of
                          tank
1    See definition, footnote 1, Table 13-3.

2    Fire  protection  for  structures  on  property  adjacent  to  liquid  storage
    shall  be  acceptable  when   located:   (1) within  the  jurisdiction  of  any
    public  fire  department; or (2)  adjacent  to  plants  having  private  fire
    brigades  capable  of  providing  cooling  water  streams  on  structures  on
    property adjacent  to liquid storage.

3    See NFPA 69,  "Explosion Prevention Systems."

Source:  Table 2-3, "(NFPA)  30:  Flammable and Combustible Liquids  Code  1984."
SI Units:  1  ft. = 0.30 m.

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                                            OSWER Policy Directive No.  9483.00-1
                                        13-16


                                   TABLE 13-6

                                UNSTABLE LIQUIDS
Type of Tank
Protection
 Minimum Distance in
  Feet from Property
 Line Which Is or Can
Be Built Upon, Includ-
  ing the Opposite
 Side of a Public Way
 Minimum Distance  in
   Feet  from  Nearest
  Side of Any Public
 Way  or From Nearest
  Important Building
 on the Same Property
Horizontal
and Vertical
Tanks with
Emergency
Relief Vent-
ing to Permit
Pressure Not
in Excess of
2.5 psig
Tank protect-
ed with any
one of the
following:
approved water
spray; approv-
ed inerting;!
approved insu-
lation and
refrigeration;
and approved
barricade

Protection for
Exposures^
                 None
Table 13-7 but not
less than 25 feet
Not less than 25 feet
                                   2-1/2 times Table
                                   but not less than
                                   50 feet
                  13-7   Not less than 50 feet
5 times table
not less than
                                13-7 but
                                100 feet
Not less than 100 feet
1   See "NFPA 69, Explosion Prevention Systems."

2   Fire protection  for  structures  on property adjacent to liquid storage shall
    be acceptable when located:  (1) within the jurisdiction of  any  public  fire
    department; or  (2)  adjacent  to plants having private  fire  brigades  capable
    of  providing  cooling water  streams  on structures  on  property  adjacent  to
    liquid storage.

SOURCE:  Table 2-4, "(NFPA) 30:  Flammable and Combustible  Liquids Code 1984."

SI Units:  1  ft. = 0.30 m.
Continued on next page.

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                                            OSWER Policy Directive No.  9483.00-1
                                        13-17
                              TABLE 13-6 Continued
Type of Tank   Protection
                                        Minimum Distance in Feet
               Minimum Distance in Feet from Nearest Side of Any
               from Property Line Which    Public Way or from
               Is or Can Be Built Upon,    Nearest Important
               Including the Opposite     Building on the Same
                Side of a Public Way	Property	
Horizontal
and Vertical
Tanks with
Emergency
Relief Vent-
ing to Permit
Pressure Over
2.5 psig
Tank protect-
ed with any
one of the
following:
approved water
spray; approv-
ed inerting;1
approved insu-
lation and
refrigeration;
and approved
barricade
2 times Table
not less than
             -Protection
              Exposures2
              None
13-7 but
50 feet
Not less than 50 feet
           for
4 times Table 13-7
but not less than
100 feet
               8 times table
               not less than
              13-7 but
              150 feet
           Not less than 100 feet
           Not less than 150 feet

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                                            OSHER Policy Directive No.  9483.00-1
                                        13-18


                                   TABLE 13-7

                               CLASS IIIB LIQUIDS
                         Minimum Distance in Feet
                         from Property Line Which
                         Is or Can Be Bui It Upon,
                          Including the Opposite
Minimum Distance in Feet
from Nearest Side of Any
   Public Nay or from
   Nearest Important
  BuiIding on the Same
Capacity (Gallons)
12,000 or Less
12,001 to 30,000
30,001 to 50,000
50,001 to 100,000
100,001 or More
Side of a Public Way
5
10
10
15
15
Property
5
5
10
10
15
SI Units'  1  ft.  = 0.3048 m;  1  gal.  - 3.785 L.

Source:   Table  2-5,   "(NFPA)   30:    Flammable   and  Combustible  Liquids  Code
         1984."  Update of the  1977  and 1981  editions.

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                                            OSWER Policy Directive No.  9483.00-1


                                        13-19


                                   TABLE 13-8

             REFERENCE TABLE FOR USE IN TABLES 13-1,  13-3,  AND 13-4
                                                    Minimum Distance  in  Feet
                         Minimum Distance in Feet   from Nearest  Side  of Any
                         from Property Line Which      Public  Nay or  from
                         Is or Can Be Built Upon,      Nearest Important
     Tank Capacity        Including the Opposite      Building on the  Same
       (Gallons)	Side of a Public Nay	     Property
275 or Less
276 to 750
751 to 12,000
12,001 to 30,000
30,001 to 50,000
50,001 to 100,000
100,001 to 500,000
500,001 to 1 ,000,000
1,000,001 to 2,000,000
2,000,001 to 3,000,000
3,000,001 or More
5
10
15
20
30
50
80
100
135
165
175
5
5
5
5
10
15
25
35
45
55
60
Source:   Table  2-5,  "(NFPA)  30:    Flammable  and  Combustible   Liquids   Code
         1984."  Upda.s of the 1977 and 1981  editions.

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                                            OSHER Policy Directive No.  9483.00-1

                                        13-20

                            13.3   INCOMPATIBLE WASTES

    Citation

    Section 264.199 contains the  special requirements for  handling  potentially
Incompatible wastes.   As  stated   in  this section, these requirements  apply  to
all precautionary measures for the entire tank system:

    (a)  Incompatible wastes, or  incompatible wastes  and  materials,  must
         not be  placed  in  the  same  tank,  system,  unless §264.17(b)  is
         complied with.
    (b)  Hazardous waste must not be  placed  in a tank, system that  has  not
         been  decontaminated  and  that  previously  held   an  incompatible
         waste  or material,  unless §264.17(b)  is complied with.

    The  requirements  of  Sec.  264.17(b)  (detailed  in  Figure  13-2)  are  that
precautionary  measures   be.  Instituted  to  ensure  that  all   incompatible,
reactive., or tgnitable wastes treated, stored, or disposed of at  a  facility  do
not react  to produce, a hazardous reaction  consequence  (e.g.,  explosion,  toxic
gas   generation,   violent   polymerization,    etc.).     Waste   compatibility
                                                           i
characteristics  must  be determined  for these  reactions  to  be avoided.   If a
waste is to be  stored in an unwashed  tank that  contained a chemical  with  which
the  waste  is  considered  incompatible, appropriate  decontamination  procedures
must be performed to avoid a hazardous reaction  consequence.

    Guidance

    Specific precautionary  measures  must be  followed   in  the  handling  and/or
storage  of potentially incompatible  hazardous  wastes   1n  order  to  prevent  or
reduce   the  chances   of   an  adverse   reaction.    Combining   or   mixing   of
Incompatible hazardous  wastes  can produce  reactions or  reaction  products that
have the potential  to  harm  human health, or  the  environment.   These hazardous
reaction   consequences  have  been  compiled  into  eight  classes,  listed  in
document Section 13.1.

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                                            OSWER Policy Directive No.  9483.00-1

                                        13-21

    Wastes are  not  necessarily  incompatible  when they react with  each  other.
Reactions involving  neutralization or dissolution of one  substance  by  another,
such  as  metals  dissolved  by  acid,   are  generally  not  considered  to  be
incompatible.    If,  however,  such  reactions  result in  fires  or  explosions  or
generate  toxic  substances  in  amounts  sufficient to  endanger public  health,
safety,  and the environment,  they are regarded as incompatible.

    If  conclusive  information  is  not  available  on  the  compatibility  of  two
wastes,   a  controlled  trial mixing of  the  wastes in  small amounts  can  be  used
to determine potential  consequences.   In general, the  following  steps  should
be used  at a facility  to determine waste compatibility:

    1.   Request from the  generator  as much information as possible about
         a waste, since  the  information required on  a  waste manifest  is
         very general  and of little use in determining compatibility.

    2.   If  a   waste  has  not  been  handled   previously   at  a facility,
         analyze a representative  sample  of it. The   information  obtained
         through  waste  analysis   should   substantiate  the  generator's
         information and determine if additional information  is  needed.

    3.   Use the information  on waste composition gathered in Steps  1  and
         2  in   conjunction  with  other  available information on  chemical
         constituents    to    determine   waste   compatibility.    If   the
         information  is  not  conclusive, potential consequences of  mixing
         the wastes  should  be determined through trial  tests.

    The  quantity of  a  sample  to be used for trial mixing  depends  on individual
circumstances.    Samples  should   be  of  sufficient  .size  to  produce  clearly
discernible effects  upon mixing.   The  samples  must,  however, be  sufficiently
small  to assure that any reaction can be controlled.

    One   can determine  the  extent of  upper  and  lower  explosive  limits  for
flammable  gases by carefully  observing  upward  flame  propagation  through  a
cylindrical  tube.   The  amounts  of  toxic  gases  produced as  a  result  of  a

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                                            OSHER Policy Directive No.  9483.00-1

                                        13-22

reaction may be  discovered  by  gas  chromatography for organics  and  by  specific
ion electrodes  for many inorganic  gases  in solution.

    One method  for quickly detecting the evolution of toxic gases  involves  the
use  of detector  tubes,  a  variety of  which  are commercially available.   To
determine if toxic gases  are produced  by the reaction being tested, the  gas  is
aspirated through a  detector  tube  for the  specific  gas.   A  change of  color in
the tube indicates the presence of a particular gas.   The  gas  concentration  is
proportional to  the  length of the changed  color in the  tube.  A  single  tube
can detect the  presence of more than 20  gases.

    The mixing  of two  wastes  for  which  only limited  information  is  available,
however,  can  result  in  highly' violent  and  dangerous   reactions.    Safety
precautions  must therefore  be taken  to  protect laboratory  personnel.   The
precautions  include   wearing   fire/explosion  protective clothing  with  safety
glasses and working in fire/explosion resistant  surroundings.   Safety  showers,
eye-wash  stations,   and  first-aid  kits  should   be  available.   All  personnel
should be familiar with fire and emergency procedures.

    The reactions between two  wastes  in a  small-scale  test may not  accurately
reflect  the   results  of   large-scale   mixing.    In  large-scale  operations,
reactions that appeared  insignificant or  were  undetectable  in  the  laboratory
can  have  significant  consequences  (such as generation of large amounts of heat
or  toxic  fumes).  Thus,  extreme  care  and  adequate   safety precautions  should
always be used  when mixing or treating large quantities of  hazardous  waste.

    In  addition  to  laboratory  testing  of  compatibility,  an  analytical  method
has  been  developed  to  determine  waste  compatibility.   This  method  uses  a
binary  combination   of   chemical   classes, to  predict  the   likely  reaction
consequence  of  combining  chemicals  from  two different   classes  at  standard
temperature  and  pressure.    The   EPA's  Municipal   Environmental   Research
Laboratory   publication,   "Design  and  Development  of  a   Hazardous   Waste
Reactivity   Testing  . Protocol"  (NTIS   number   PB8-4158807,    1984),   details
laboratory procedures to classify an unknown waste into a reactivity class.

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                                            OSHER Policy Directive No.  9483.00-1


                                        13-23


    Classes of  chemical  compounds  are  listed  in  Table  13-9.   Compounds  are
classified according to similar molecular structure (classes  1-31)  and  similar

reactivity characteristics  (classes  32-38).  In Table  13-10,  a  representative

list of chemicals for  each  class is provided.   If further chemical  identifi-

cation is  necessary, it may be obtained from the following sources:


    o    "Dangerous   Properties  of  Industrial  Materials,"  6th  ed.  (Sax,
         1984);

    o    "The  Merck  Index,"  10th ed.  (Merck, 1983);

    o    "A Method for Determining the Compatibility of  Hazardous Wastes"
         (Hatayama  et  al.,   1980);  EPA-600/2-80-076,  April  1980,  US  EPA
         Office  of  Research  and  Development (soon to be  released by  ASTM
         as a  standard);

    o    "A Compatibility  Guide  for  Regulated  Chemical  Substances  and
         Underground  Storage  Tanks,"  Draft  Technical  Report  for  USEPA
         Office    of   Solid   Waste,   Contract   No.   68-0-7053;   Jacobs
         Engineering Group;  December 20,  1985;

    o    "Proposed  Guide-  for Estimating  the  Incompatibility  of  Selected
         Hazardous  Wastes  Based on  Binary  Chemical Reactions";  ASTM  D-34
         Proposal  P-168, 1986;

    o    "Guide   and  Procedures  Manual"  (MD489/D335),   Toxic  Substance
         Storage  Tank  Containment Assurance and Safety Program,  State  of
         Maryland,  Department of  Health and  Mental   Hygiene,  Office  of
         Environmental Programs, Baltimore,  MD, September  1983;

    o    Online   chemical  databases  such as  OHMTADS,   CHEMTREC,  CIS  and
         TOXLINE;

    o    Chemical  manufacturer;

    o    Waste generator; and

    o    Manifests that accompany a waste.

    Using  the hazardous  waste compatibility matrix illustrated  in  Figure
13-3, one  can determine,  in advance,  the potential for an incompatibility
reaction.   In  this  manner,  the  user  can avoid  mixing  two  incompatible
wastes and/or  can develop  a  method of  tank  decontamination  that lessens
the  likelihood  of  such  a reaction.    It  is important  to note,  however,
that the matrix assumes  the chemicals  to be  of  100 percent concentration
at  standard  temperature  (25*C)  and  pressure  (760  mm  Hg).   Changes  in
these  conditions  are  likely to  affect  the degree  and  type of  chemical
reaction(s).   Another  drawback  of  this  method  is  that  incompatibility
reactions   involving  more than  two  chemicals  are  not  ascertainable using
the Figure 13-3 matrix.

-------
                                            OSHER Policy Directive No. 9483.00-1


                                        13-24
                                   TABLE 13-9

                            LIST OF CHEMICAL CLASSES
      Chemical
    Class Number                          Class Name
          1         Acids, mineral, non-oxidizing
          2         Acids, mineral, oxidizing
          3         Acids, organic
          4         Alcohols and glycols
          5         Aldehydes
          6         Amides
          7         Amines, aliphatic and aromatic
          8         Azo compounds, diazo compounds and hydrazines
          9         Carbamates
         10         Caustics
         11         Cyanides
         12         Oithiocarbamates
         13         Esters
         14         Ethers
         15         Fluorides-, Inorganic
         16   -     Hydrocarbons, aromatic
         17         Halogenated organics
         18         Isocyanates
         19         Ketones
         20         Mercaptans and other organic sulfides
         21         Mfe'^al  compounds, inorganic
         22         Strides
         23         Nitrites
         24         Nitro compounds
         25         Hydrocarbons, aliphatic, unsaturated
         26         Hydrocarbons, aliphatic, saturated
         27         Peroxides and hydroperoxides, organic
         28         Phenols and cresols
         29         Organophosphates, phosphothioates, and phosphodithioates
         30         Sulfides, inorganic
         31         Epoxides
         32         Combustible and flammable materials
         33         Explosives
         34         Polymerizable compounds
         35         Oxidizing agents, strong
         36         Reducing agents, strong
         37         Water and mixtures containing water
         38         Water reactive substances
Source:  "A  Method  for   Determining  the  Compatibility  of  Hazardous  Wastes"
         (Hatayama et al., 1980).

-------
                                            OSWER Policy Directive No. 9483.00-1
                                        13-25


                                   TABLE  13-10

                    LIST  OF  CHEMICAL  REPRESENTATIVES  BY  CLASS
Class 1   Acids, mineral, non-oxidizing    Class 5  Aldehydes (All  Isomers)
    Boric Acid
    Chlorosulfonic Acid
    Hydriodic Acid
    Hydrobroiric Acid
    Hydrochloric Acid
    Hydrocyanic Acid
    Hydrofluoric Acid
    Hydroidic Acid
    Phosphoric Acid

Class 2  Acids, mineral, oxidizing

    Chloric Acid
    Chromic Acid
    Nitric Acid
    Oleum
    PercTiloric Acid .
    Sulfuric Acid
    Sulfur Trioxide

Class 3  Acids, organic (All Isomers)

    Acetic Acid
    Benzoic Acid
    Formic Acid
    Lactic Acid
    Maleic Acid
    Oieic Acid
    Salycilie Acid
    Phthalic Acid

Class 4  Alcohols and glycols (All
         Isomers)

    Ally! Alcohol
    Chlorethanol
    Cyclohexanol
    Ethanol
    Ethylene Chlorohydrin
    Ethylene Glycol
    Ethylene Glycol Monomethyl Ether
    Glycerin
    Methanol
    Monoethanol Amine
    Acetaldehyde
    Formaldehyde
    Furfural

Class 6  Amides (All Isomers)

    Acetamide
    Diethyl amide
    Dimethylformamide

Class 7  Amines, aliphatic and
         aromatic (All  Isomers)

    Aminoethanol
    Aniline
    Diethylamine
    Diamine
    Ethylenendiamine
    Methyl ami ne
    Monoethylanolamine
    Pyridine

Class 8  Azo  compounds, diazo
         compounds and  hydrazines

    Dimethyl  Hydrazine
    Hydrazi ne

Class 9  Carbamates

Class 10  Caustics

    Ammonia
    Ammonium  Hydroxide
    Calcium  Hydroxide
    Sodium Carbonate
    Sodium Hydroxide
    Sodium Hypochlorite

Class 11  Cyanides

    Hydrocyanic Acid
    Potassium Cyanide
    Sodium Cyanide
Continued on next page.

-------
                                            OSHER Policy Directive No. 9483.00-1
                                        13-26
                              TABLE  13-10  Continued
Class 12  Pithiocarbamates

Class 13  Esters (All Isomers)

    Butyl Acetate
    Ethyl Acetate
    Methyl Acrylate
    Methyl Formate
    Dimethyl Phthalate
    Propiolaetone

Class 14  Ethers (All Isomers)

    Dichloroethyl Ether
    Oioxane
    Ethylene Glycol Monomethyl Ether
    Furan
    Tetrahydrofuran

Class 15  Fluorides, Inorganic

    Aluminum Fluoride
    Ammonium Fluoride
    Fluorosi1 icic Acid
    Fluosilie Acid
    Hydrof1uorosi1icic Acid

Class 16  Hydrocarbons, aromati-c (All
          Isomers)

    Benzene
    Cumene
    Ethyl Benzene
    Naphthalene
    Styrene
    Toluene
    Xylene

Class 17  Haloqenated organics (All
          Isomers)

    Aldrin
    Benzyl Chloride
    Carbon Tetrachloride
    Chloroacetone
    Chlorobenzene
Class  17  Halogehated organics  (All
          Isomers)  (Continued)

    Chlorocresol
    Chloroethanol
    Chloroform
    Dichloroacetone
    Dichloroethylether
   - Dichloromethane  (Methylene
       Bichloride)
    Epichlorohydrin
    Ethylene Chlorohydrin
    Ethylene Dichloride
    Freons
    Methylchloride
    Pentachlorophenol
    Tetrachloroethane
    Trlchloroethylene

Class  18  Isocyanates  (All  Isomers)

Class  19  Ketones  (All  Isomers)
i    *       I.

    Acetone
    Acetophenone
    Cyclohexanone
    Dimethyl Ketone
    Methyl Ethyl Ketone
    Methyl Isobutyl  
-------
                                            OSWER Policy Directive No. 9483.00-1
                                        13-27
                              TABLE  13-10  Continued
Class 22  Nitrides

Class 23  Nitrites

    Acrylonitrile

Class 24  Nitro compounds (All Isomers)

    Nitrobenzene
    Nitrophenol
    Nitropropane
    Nitrotoluene
    Picric Acid

Class 25  Hydrocarbons, aliphatic,
          unsaturated (All Isomers)

    Butadiene
    Styrene
Class'26  Hydrocarbons, aliphatic,
          saturated
    Butane
    Cyclohexane

Class 27  Peroxides and hydroperoxldes,
          or gam' c

    Benzoyl Peroxide
    Hydrogen Peroxide
    Chlorocresol
    Coal Tar
    Cresol
    Creosote

Class 28  Phenols and cresols

    Hydroquinone
    Nitrophenol
    Phenol
    Picric Acid
    Resorcinol
Class 29  Qrganophosphates, phospho-
          thioates, and phosphodi-
          thioates

    Malathion
    Parathion

Class 30  Sulfides, inorganic

Class 31  Epoxides

    Epichlorohydrin

Class 32  Combustible and flammable
          materials
    Diesel Oil
    Gasoline
    Kerosene
    Naphtha
    Turpentine

Class 33  Explosives

Benzoyl  Peroxide
    Picric Acid

Class 34  Polymerizable compounds

    Acryloni trile
    Butadiene
    Methyl Acrylate
    Styrene

Class 35  Oxidizing agents, strong
    Chloric Acid
    Chromic Acid
    Silver Nitrate
    Sodium Hypochlorite
    Sulfur Trioxide

Class 36  Reducing agents, strong

Diamine
Hydrazine
Continued on next page.

-------
                                            OSWER Policy Directive No. 9483.00-1


                                        13-28


                              TABLE  13-10 Continued
Class 37  Mater and mixtures containing
          water

    Aqueous solutions and mixtures
    Water

Class 38  Hater reactive substances

    Acetic Anhydride
    Hydrobromic Acid
    Sulfuric Acid
    Sulfur Trioxide
SOURCE:  "A  Method  for  Determining  the  Compatibility  of  Hazardous  Wastes"
         (Hatayama et al.,  1980).

-------
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-------
                                            OSWER Policy Directive No. 9483.00-1

                                        13-31

    If several  classes of chemicals compose a waste  stream,  all  non-negligible
pairs  of  classes  in  the   two  hazardous  wastes  must  be  tested  using  the
compatibility matrix  process.   In  cases where the user  is  unsure of  how  much
of  a particular  chemical  class  is  present  and  how significantly  this  class
will  affect  compatibility,   it  is  b.est to  assume incompatibility  and  proceed
with non-mixture and/or tank washing methods.

    If  chemical   incompatibility   is   found   for  an  unwashed  tank  system,
decontamination methods  should  be  based on the type  of compound found  in  the
unwashed system.   Specific  methods  of  decontamination for storage tank systems
are outlined in Table 13-11.  Decontamination steps begin when a  tank has  been
emptied.  A  tank   system that  contained wastes  must be  rinsed  with  a solution
compatible with the waste residues.

    The  following hypothetical  cases  present  examples of the  method  that
should  be   applied  to  determine  chemical  compatibility,  using the  compati-
bility matrix of Figure 13-3.

Example 1

    The  receiving  tank  system  previously contained  chromic  acid.    It  is  now
proposed that  potassium cyanide  be  stored in  this  unwashed tank.   Using  the
information in Table 13-10,   it can be determined that chromic acid  is in class
35  (strong oxidizing  agents) and potassium cyanide  is  in class  11  (cyanides).
The letter abbreviation  at  the  point of  intersection in  Figure  13-3 indicates
the  likely reactions:   heat generation, as a primary reaction consequence,  and
explosion and  toxic  gas generation as   a  secondary  consequence,  resulting  from
the heat generation.   It can be concluded  that  these  two wastes are extremely
incompatible.  In  order to  be able  to store potassium  cyanide  in  this  tank,
all   chromic   acid   residues  must  be  removed  and  the  tank  system  fully
decontaminated.  The  method  of  decontamination  will  involve draining  the  tank
system,  removing   any  solids,  applying  a  caustic  wash, and  rinsing with  a
high-pressure stream of water (see Table 13-11).

-------
                                            OSWER Policy Directive No.  9483.00-1

                                        l~3-33

Example 2

    A  no-hazard  situation  may  involve  the  addition   of  acetone  (class  19,
ketones)  to  a   tank   system  that  once  contained  acetaldehyde  (class  5,
aldehydes).   According  to  the matrix  in  Figure  13-3,  no reaction  consequence
is indicated, and the two compounds are considered generally compatible.

                          13.4   SUMMARY  OF MAJOR  POINTS

    The  following  summarizes   the  information  covered  in   this  section  and
should be used to assure the completeness of a Part B permit application.

    o    Do  precautionary  measures   apply  to  tanks  and  all   ancillary
         equipment?

    o    Has compliance wi'th dissipation of hazard been documented?

    o    Exempt  in emergency  situations,  have  all  wastes  been  treated,
         mixed, or rendered inert prior to  or  immediately  after  placement
         in the storage tank?

    o    Do  facility  design  and  operating  characteristics  protect  waste
         from  any materials  or  conditions  that  may   cause  ignition  or
         reaction?

    o    Are treatment and mixture processes waste-specific?

    o    Does  the  tank   system   comply  with  essential   National   Fire
         Protection Association protective distance requirements?

    o    Mixing of incompatible  wastes  or  placement of  waste  in a  tank
         system  that  previously  held   an  incompatible  waste   are  not
         allowed,   unless   a   hazardous   reaction  consequence    can   be
         prevented.

-------
        OSWER Policy Directive No. 9483.00-1
APPENDIX A

-------
                                   APPENDIX  A
                             COMPLETENESS  CHECKLIST
    Appendix A  contains  a checklist of items that  may  be  included in an  RCRA
Part  B  permit  application.   Use  of  this   checklist   is   not   a regulatory
requirement.  However,  its  use,  or  use  of  a   similar  document, is  strongly
recommended.  Use  of  the  checklist  will   assist   the  permit   applicant  in
confirming that  he/she  is submitting a complete  application.

    Each  required  information  item is summarized.   Regulatory   citations  are
provided  that enable  quick  location  of the  full  text  of  the  regulation  for
each required item.  If  no citation is indicated next to a  specific  item, the
last citation indicated above the  item contains  the  regulatory requirement.

-------





























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        OSWER Policy Directive No. 9483.00-1
APPENDIX 8

-------
                                             OSWER Policy Directive No.  9483.00-1

                                         B-l

                                   APPENDIX B

                            PAINT  FILTER  LIQUIDS  TEST

                                   METHOD 9095

1.0  Scope and ApplIcation

     1.1  This method is  used  to  determine  the  presence  and/or  concentration
of free  liquids  in  a representative sample of waste,  or to separate the liquid
and solid portions of a  sample.

     1.2  The  method is  used  to  determine  compliance  with  40  CFR  261.21,
261.22, 264.314,  and 265.314.

2.0  Summary of Method

     2.1  A  predetermined  amount  of material  is placed  in a  paint  filter and
the free  liquid  portion  of the material   is  that portion which  passes  through
and drops from the filter.

3.0  Interferences

     3.1  Filter  media   was observed  to  separate from  the  filter  cone  on
exposure  to  alkaline materials.   This  development causes  no  problem   if the
sample is not disturbed.

4.0  Apparatus and Materials

     4.1  Conical  paint  filter  -  mesh  number  60.   Available at  local  paint
stores  such  as Sherwin-Williams  and Glidden for an approximate  cost of $0.07
each.

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                                             OSWER Policy Directive No.  9483.00-1

                                        B-2

     4.2  Glass Funnel  [If  the  paint  filter,  with  the  waste, cannot  sustain
its weight on  the  ring  stand,  then a  fluted glass  funnel  or glass funnel  with
a mouth large enough to allow at "least" one 1 nth of the filter  mesh  to protrude
should  be  used to  support  the filter.   The funnel  is  to be  fluted  or  have  a
large open mouth  in  order  to support  the  paint  filter  yet not interfere  with
the movement,  to  the  graduated cylinder,  of the liquid  that passes through the
fi Her mesh. ]

     4.3  Metal Ring or Tripod

     4.4  Ring Stand

     4.5  Graduated Cylinder, 100 ml.

     4.6  Glass Rod, 6"

     4.7  Watch Glass  (for  use  if percent free  liquid  or free liquid  portion
                      f
is desired)

5.0  Reagents

     5.1  None.

6.0  Sample Collection, Preservation,  and Handling

     6.1  All  samples must  be  collected according to the directions  in Section
One of this manual.

     6.2  A  100  ml  or  lOOg representative  sample  is required for  the  test.
[If  it  is   not  possible  to  obtain   a  sample  of  100  ml   or   lOOg that  is
sufficiently  representative of  the waste,  the  analyst may  use  larger  size
samples in multiples  of 100 ml or lOOg,  i.e.,  200, 300, 400 ml or g.  However,
when larger samples are used,  analysts  shall  divide the sample into 100 ml  or
lOOg portions  and  test each portion separately.   If  any portion  contains free
liquids the entire  sample  is considered to have free liquids.  If the percent

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                                             OSHER Policy Directive No.  9483.00-1

                                         B-3

of free liquid  in  the sample needs to  be  determined,  it shall be  the  average
of the sub-samples tested.]

7.0  Procedure

     [In  order  to  determine compliance with  40 CFR  264.314 or  265.314  only
Steps 7.1  through 7.4 should be used.]

     7.1  Assemble test apparatus as shown  in Figure 1.

     7.2  Place sample in the filter.   A funnel  may be used  to provide  support
for the pai nt fi1ter.

     7.3  Allow sample to drain for 5 minutes into the graduated cylinder.

     7.4  Note  any  free  liquid  generated  after  this  five  minute  period.   If
any liquids  collect  in-the graduated cylinder  then  the  material   is  deemed  to
contain free liquids,  for purposes of 40 CFR 2B4.314 or 265.314.

     Continue with Steps 7.5 through  7.7 to determine  the  percent free liquid
or to prepare the liquid  phase for further  testing, if appropriate.

     7.5  Read and record  volume of liquid phase  in  graduated cylinder.   Stir
sample with glass rod, let  stand undisturbed for an additional 15 minutes.

     7.6  Read and record volume of liquid  phase.

     7.7  Calculate  t change   between   the  two  15  minute  readings.  If  the
difference is  less  than  10%, the test  is  complete.   If the  change  is  greater
than  10%,  repeat  steps  7.5  through  7.7 until  the  change  between successive
readings is less than 107..

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                                             OSWER Policy Directive No. 9483.00-1

                                         B-4

Calculations:

     Current Reading (ml) - Preceding Reading (m.) x 100 = % Change
          Preceding Reading (ml)

     Total Liquid Phase (ml) x 100 = 1 Free Liquid
          Sample Size (ml)

8.0  Quality Control

     8.1  Duplicate samples should be analyzed on a routine basis.

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                     OSWER Policy Directive No. 9483.00-1





                 B-5
FIGURE 1.   FREE LIQUID APPARATUS

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        OSHER Policy Directive No. 9483.00-1
APPENDIX C

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                                             OSWER  Policy  Directive  No.  9483.00-1

                                        C-l

                                   APPENDIX C
                   Synopsis  of  Pertinent  EPA  Guidance  Manuals
1.  "Model   Permit   for   Hazardous  Waste   Treatment,   Storage   &   Disposal
    Facilities,"   USEPA   (undated   draft).    Companion  to  "Permit   Writer's
    Guidance Manual  for Hazardous  Waste  Land Treatment,  Storage  and  Disposal
    Facilities,"   the  model   permit   provides  a  standard  permit  format  for
    facilities that  store,  treat, or  dispose  of  hazardous waste.  The  model  is
    divided into  modules  for  various  types of permit  conditions.

2.  "Compatibility  of  Wastes   in   Hazardous Waste   Management  Facilities—A
    Technical  Resource Document  for Permit  Writers," USEPA  (November  1982).
    This  manual  provides  guidance  on  how  to determine  the  compatibility  of
    hazardous   wastes  with  other   wastes  and   with  the  various   types   of
    structures -  tanks,  piles,  and  containers  - in  which they are  stored or
    treated.

3.  "Design & Development  of  a  Hazardous Waste  Reactivity Testing  Protocol,"
    USEPA  (October  1984).    The  test  scheme developed  for determining  waste
    compatibility includes  a  field-test kit,  a  series of flow diagrams,  and  a
    manual  for using  the  flow diagrams  and test  procedures.   It also employs  a
    compatibility chart,  which   classifies   wastes  by  chemical  class  and/or
    general reactive  properties, and  establishes  a  series of qualitative  test
    procedures to classify hazardous waste materials  according  to their  gross
    chemical   composition  when   little   or   no  prior  knowledge  is   available
    regarding  their  components.   The  scheme is organized  in a manner  such  that
    materials  with  high  reactivity or  unusual  hazard are identified  early in
    the  testing  sequence.   Chemical  composition  information  is then  used  to
    predict  which  waste  materials  can  safely be mixed  before   actually
    performing mix tests.

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                                             OSWER Policy Directive No.  9483.00-1

                                        C-2

4.   "Permit Applicant's  Guidance  Manual  for  the  General  Facility Standards,"
    USEPA,  SW968  (October   1983).    Guidance  for   permit  applicants   that
    addresses general Information requirements of  40  CFR Sec.  270.14(b)  (1-12,
    19) and the Sec.  264 standards referenced by  those requirements for  Part  B
    applications.

5.   "RCRA  Permit  Writer's  Manual  for  Ground Water Protection (40 CFR  264F),"
    USEPA  (October  1983).   Provides  a  comprehensive   examination  of  items
    covering  ground   water  protection  requirements  for  permit   writers  to
    examine when reviewing  Part B  applications.

6.   "Permit Applicant's Guidance  Manual  for  Exposure  Information  Requirements
    Under  RCRA  Section  3019," USEPA  (1985).  This document was developed for
    owners and operators of hazardous  waste  landfills  and  surface  impoundments
    which  are  subject  to  permitting  under  the  Resource  Conservation  and
    Recovery Act  (RCRA).   It  provides  guidance for  submitting  information  on
    the  potential  for  public exposure  to  hazardous  wastes,.as  required  by
    Section  3019  of  RCRA,   which  was  established by  the  1984  Hazardous  and
    Solid Waste Amendments  to RCRA.

7.   "Alternate   Concentration   Limit   Guidance  Based   on   Section   264.94(b)
    Criteria, Part I,  Information  on  ACL  Demonstrations,"  USEPA  (June  1985).
    This  document provides  guidance   to  RCRA facility  permit  applicants  and
    writers  concerning  the  establishment  of  alternate  concentration  limits
    (ACLs).

8.   "Draft Guidance  for  Subpart G Closure  and Post Closure  Care Standards and
    Subpart H Cost Estimating Requirements,"  USEPA (to be published in  Fall  of
    '86)   outlines   procedures  for  TSDF's   for  complying   with  regulatory
    requirements for  closure and post  closure care.

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        OSHER Policy Directive No. 9483.00-1
APPENDIX D

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                                             OSWER  Policy  Directive  No.  9483.00-1

                                        D-l   .

                                   APPENDIX D

                          Technical  Guidance Documents
1.  "Technology  for  the  Storage  of   Hazardous   Liquids—A   State-of-the-Art
    Review," by Fred C.  Hart,  Associates,  for  the  New York State  Department  of
    Environmental  Conservation  (January  1983).   This  manual  is  a  compilation
    of much of  the  latest  information  on  underground  and  aboveground  storage
    systems  and  on  state-of-the-art   equipment   available   for   storing  and
    handling  hazardous  liquids  in  tanks.   Included  is  a discussion  on  the
    technology  and   practices  for  storage of  petroleum  and  other  hazardous
    liquids which could  be  accidentally  released  into the environment.   Among
    the   topics   covered   are:    design   features;   piping    systems;   spill
    containment systems;  spills  and  overfill  prevention  systems;  leak  and
    spill   monitoring;   and  testing  and   inspection  for both  underground  and
    aboveground tanks.                                    . •

2.  "Recommended Practices for Underground  Storage of  Petroleum,"  by  Fred  C.
    Hart  Associates  for  the  New  York  State  Department   of  Environmental
    Conservation (May 1984).   This  manual   provides  specific  guidance  for  the
    underground storage of  petroleum  and  petroleum-derivative  liquids.   The
    manual'is intended  for engineers,  inspectors,  and owners  who  are  designing
    or upgrading  their  underground facilities  for  leak and  spill  prevention.
    Specific  guidance   includes:   (1)   design  of  tanks  and  piping  systems;
    (2) installation of underground  storage  tanks;  (3)  secondary containment;
    (4) leak detection;  (5) overfill  protection and  transfer  spill  prevention;
    (6) tightness testing;  (7)  storage  tank rehabilitation;  and (8) closure  of
    underground storage  facilities.

3.  "Lining  of  Waste   Impoundment  and  Disposal   Facilities,"  by  Matrecom,
    Incorporated,   for   the  USEPA  (September   1980).   Based   upon  the  current
    state  of  the art. of liner technology,   this report  provides  information  on
    performance,  selection,   and  installation  of  specific   liners and  cover
    materials for various disposal situations.  It characterizes  wastes,  waste
    fluids, lining  materials,  and lining technology.  It further  describes  the

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                                         OSWER Policy Directive Mo.  9483.00-1

                                    D-2

effects  various  wastes  have  on  liners;  liner  service  life  and  failure
mechanisms; installation  problems;  cost  information;  and  tests  that  are
essential for  preinstallation  and  monitoring surveys.

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        OSHER Policy  Directive  No.  9483.00-1
APPENDIX E

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                                             OSWER Policy Directive No.  9483.00-1

                                        E-l

                                   APPENDIX E

                            Tank-Specific Definitions

    When used in  40  Part  264,  Subpart 0 (as  revised  July 14,  1986),  the terms
in this manual  have the following meanings:

    "Aboveground Tank" (ACT) means  a  device meeting  the definition of  "tank"
as  set  forth in  Sec.  260.10 that  is  situated  in  such a way that  the  entire
surface  area of  the  tank   is  completely  above  the   plane  of  the  adjacent
surrounding  surface  and  the entire surface  area of  the tank  (including  the
tank bottom) can be visually inspected.

    "Acutely Hazardous Waste" meets the  following criteria, as  defined  in  40
CFR 261.10:

    It has  been found  to  be fatal  to  humans in low doses or,  in  the absence of
    data on human  toxicity,  it  has  been  shown -in studies to have  an oral  ID 50
    toxicity (rat) of less  than 50 milligrams per kilogram, an  inhalation LC
    50 toxicity (rat)  of  less  than 2  milligrams  per  liter,  or  a dermal  LD  50
    toxicity (rabbit) of  less  than  200  milligrams per  kilogram or  is  otherwise
    capable of  causing or  significantly  contributing  to  an  increase  in  serious
    irreversible,  or  incapacitating reversible, illness.

    "Ancillary   equipment"  means  any device  including,  but not  limited  to,
such devices as piping, fittings,  flanges, valves and  pumps, that  is used  to
distribute,  meter, or control  the  flow of  hazardous  waste from  its point of
generation  to  storage or  treatment tank(s),   between  hazardous  waste  storage
and treatment tanks  to  a  point of disposal on-site, or to a point of shipment
for disposal off-site.

    "Aquifer" means  a  geologic  formation,   group  of  formations,  or  part of  a
formation capable of  yielding  a  significant amount of  ground water to wells or
springs.

    "Certification"  means  a statement  of  professional  opinion   based  upon
knowledge and belief.

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                                             OSWER Policy Directive No.  9483.00-1

                                        E-2

    "Component"  means  either  the  tank  or   ancillary   equipment   of  a   tank
system.

    "Corrosion expert" means  a person who,  by  reason  of his knowledge of  the
physical  sciences and the  principles  of engineering and mathematics,  acquired
by a professional education and  related practical experience, is  qualified  to
engage  in  the  practice  of  corrosion  control  on  buried  or  submerged  metal
piping  systems  and  metal  tanks.   Such  a  person must  be  certified as  being
qualified by  the  National  Association of  Corrosion Engineers (NACE)  or be  a
registered  professional   engineer  who has   certification  or  licensing  that
includes education and experience  in  corrosion  control  on buried  or  submerged
metal piping systems  and  metal  tanks.

    "Existing  tank,  system" or "existing  component"  means  a tank system  or
component that is used for the storage  or treatment of hazardous  waste  and  is
in  operation,  or  the  installation  of which  has  begun,  on or  prior to  the
effective  date  of  the  regulations  (July  14,   1986).   Installation  will   be
considered  to  have   commenced  if  the  owner  or  operator  has  obtained  all
federal,  state,  and  local approvals  or  permits  necessary  to  begin  physical
construction  of  the  site  or  installation of the tank system, and  if  either:
(1)  a  continuous on-site  physical   construction  or  installation  program  has
begun;   or   (2)   the   owner   or  operator  has  entered   into   contractual
obligations—which  cannot  be  cancelled  or  modified  without   substantial
loss—for  physical construction on  the site  or  installation  of  the tank system
scheduled to be completed within  a reasonable time.

    "Facility"  means  all  contiguous  land,  structures,   appurtenances,  and
improvements  on  the  land  used  for treating,  storing,  or disposing  of hazardous
waste.   A facility  may   consist  of  several  treatment,  storage,  or  disposal
operational  units  (e.g.,  one  or  more  landfills, surface  impoundments,  or
combinations of them).

    "Freeboard"  means  the vertical  distance between  the top  of  a  tank,  or
surface impoundment dike, and the surface  of the waste contained  therein.

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                                             OSWER Policy Directive No.  9483.00-1

                                         E-3

    "Groundwater" means water below the land surface in a zone of saturation.

    "Incompatible  waste"  means  a hazardous  waste which  is  unsuitable  for:
(1)  placement  in  a  particular  device  or  facility  because   it  may  cause
corrosion or  decay of  containment materials (e.g., container inner  liners  or
tank  walls);  or  (2)   co-mingling   with  another  waste  or  material   under
uncontrolled  conditions  because  the   co-mingling  might  produce  heat   or
pressure, fire  or explosion,  violent  reaction,  toxic  dusts,  mists, fumes  or
gases, or flammable fumes or gases.

    "Inground  tank"  (IGT)  means  a  device  meeting the  definition of  "tank"
set forth in  Sec.  260.10 that has a portion of  the tank wall  situated  to  any
degree  on  or  within   the   ground,   thereby  preventing   expeditious   visual
inspection of the surface area of the tank that is  on  or in the ground.

    "Installation  inspector"  means a  person  who,   by  reason  of  his  knowledge
of  the  physical  sciences and the  principles  of  engineering,  acquired by  a
professional  education  and  related  practical  experience,   is  qualified  to
supervise the installation of tank systems.

    "Leak-detection  system"  means a  system capable  of  detecting  either  the
failure  of  the primary  or  secondary containment structure or  the  presence  of
hazardous waste or accumulated  liquid  in the secondary  containment  structure.
Such a  system must employ operational  controls (e.g.,  daily visual  inspections
for releases  into the  secondary containment system of aboveground  tanks)  or
consist  of  an interstitial   monitoring  device  designed  to  detect continuously
and  automatically  the  failure  of   the  primary  or   secondary  containment
structure or  the presence of  a  release  of hazardous  waste into  the  secondary
containment structure.

    "New  tank  system"  or   "new  tank  component" means  a   tank   system   or
component that  will  be  used for  the  storage  or  treatment of  hazardous waste
and for which installation has commenced  after  January  12, 1987.  However,  for
the purposes  of Sees.   264.193(g)(2)  and 265.193(g)(2),  a  new tank  system  is
one  for  which  construction  commences   after  January  12,1987.   (See  also
"existing tank system.")

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                                             OSHER Policy Directive  No.  9483.00-1

                                        E-4

    "Onground  tank"  means  a  device  meeting   the  definition   of   "tank"  in
Sec. 260.10  that  is  situated  in  such a way  that  the bottom of  the  tank is on
the same level as  the  adjacent surrounding surface  so  that  its external  tank.
bottom cannot be  visually inspected.

    "Sump"  means  any pit or reservoir  that  meets the definition of  tank, and
those troughs/trenches connected to  it  that  serve  to collect  hazardous waste
for transport to  hazardous waste  storage,  treatment, or  disposal facilities.

    "Tank"  means  a stationary device,  designed to contain an  accumulation of
hazardous  waste,   which   is  constructed  primarily  of   non-earthen  materials
(e.g., wood,  concrete,  steel,  plastic)  which  provide structural  support.

    "Tank  system"  means  a hazardous  waste storage  or  treatment tank  and Us
associated  ancillary equipment  and  containment  system.

    "Underground   tank"  (UGT)   means  a  device  meeting  the   definition  of
"tank"  set  forth 'in  Sec.   260.10,  whose  entire  surface   area   is   wholly
submerged within  the ground (i.e.,  totally below the surface of  and  covered by
the ground).

    "Unfit-for-use tank  system"  means  a  tank  system that has  been  determined
through an  integrity assessment or  other inspection to be no  longer  capable of
storing or treating  hazardous  waste  without  posing a threat  of  hazardous waste
release to  the environment.

    "Zone  of engineering  control"  means  an area  under  the   control   of  the
owner or operator that,  upon  detection of  a  hazardous waste  release,  can be
readily  cleaned  up  prior to  the  release  of  hazardous  waste  or  hazardous
constituents  to ground water  or surface water.

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    OSWER Policy Directive No. 9483.00-1
APPENDIX F

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                                             OSWER  Policy Directive  No.  9483.00-1
                                        F-l
                                   Appendix  F

                                 FIGURE  SOURCES
FIGURE   TITLE
                                 PAGE    SOURCE
                            SECTION 5.0 TANK DESIGN
5-1
5-2

5-3

5-4
5-5


5-6
5-7
5-8
Tank. Dimensions
Tank Dimensions (cont.)

Tank Dimensions (cont.)

Piping Details for Suction or
  Submerged Pumps
Elements of an Underground
  Storage Facility

Aboveground Tank System
  Connections
Corrosion Mechanisms
Corrosion Mechanisms (cont.)
5-3    American  Petroleum Institute,
       Specification  12D, "Field
       Welded Tanks for Storage of
       Production Liquids" 9th ed.
       (January  1982),.p.8.

5-4    Fred C.  Hart Associates, Inc.

5-5    Fred C.  Hart Associates, Inc.

5-20   American  Petroleum Institute,
       Publication No.  1615,
       "Installation  of Underground
       Petroleum Storage Systems"
       (November 1979), p. 11.

5-21   Fred C.  Hart Associates, Inc.
5-22   American Petroleum Institute,
       Publication  No.  RP 12Ra,
       "Recommended Practices for
       Setting, Connecting,  Mainten-
       ance,  and Operation of Lease
       Tanks" (1981).

5-27   New York State  Department of
       Environmental  Conservation,
       "Technology  for the Storage
       of Hazardous Liquids  - A
       State-of-the-Art Review"
       (January 1983),  p. 15.

5-28   New York State  Department of
       Environmental  Conservtion,
       "Technology  for the Storage
       of Hazardous Liquids  - A
       State-of-the-Art Review"
       January, (1983), p. 16.

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                                             OSWER Policy Directive No.  948j.00-l
                                        F-2
                             Appendix  F  (Continued)

                                 FIGURE  SOURCES
FIGURE   TITLE
                                 PAGE   SOURCE
5-9
5-10
5-11


5-12
Sacrificial-Anode Cathodic
  Protection
Factory-Installed Sacrificial-
  Anode
Impressed-Current Cathodic-
  Prqtection

Anchoring Techniques
             5-43   "Suggested Ways to Meet
                    Corrosion Protection Codes
                    for Underground Tanks and
                    Piping" Detroit, Michigan:
                    (The Hinchman Company).

             5_44   U.S. Environmental Protection
                    Agency, Office of Solid Waste,
                    "Interim Prohibition:  Guid-
                    ance for Design and Installa-
                    tion of New Underground Stor-
                    age Tanks" (August 1985
                    Draft)  p. 1-11.

             5-46   Fred C  Hart Associates, Inc.
             5-50.   Petroleum Equipment
                    Institute,  Publication No.
                    PEI/RP100-85, "Recommended
                    Practices for Installation  of
                    Underground Liquid Storage
                    Systems (undated draft)  p.  11.
                            SECTION 6.0 INSTALLATION
6-1


6-2
6-3
Proper Tank Lifting
  Placement
and
Excavation Design:
  Recommended Di stance from
  the Nearest Foundation
Excavation
6-5    Fred C.  Hart Associates,  Inc.
             6-8    Petroleum Equipment Institute,
                    "Recommended Practices for
                    Installation of Underground
                    Liquid Storage Systems,"
                    1986,  p.  5.

             6-9    U.S.  Environmental  Protection
                    Agency,  Office of Solid Waste,
                    "The  Interim Prohibition:
                    Guidance For Design and
                    Installation of Underground
                    Storage  Tanks," (August 1985
                    Draft),  pp.  2-3.

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                                            OSWER  Policy  Directive  No.  9483.00-1
                                        F-3
                             Appendix  F  (Continued)

                                 FIGURE  SOURCES
FIGURE   TITLE
                                 PAGE    SOURCE
6-4

6-5
6-6
6-7
Tank Installation Checklist

Backfill
Partially Buried Vertical
  Hazardous Waste Tank with
  Secondary Containment

Underground Tank and Piping
  System
6-8
Aboveground Tank
6-10   Fred C.  Hart Associates,  Inc.

6-16   U.S. Environmental  Protection
       Agency,  Office of Solid Waste,
       "The Interim Prohibition:
       Guidance for Design and
       Installation of Underground
       Storage  Tanks," (August 1985
       Draft),   p.  2-3.

6-24   Fred C.  Hart Associates,  Inc.
6-25   U.S.  Environmental  Protection
       Agency, Office of Solid Waste,
       "The  Interim Prohibition:
       Guidance for Design and
       Installation of Underground
       Storage Tanks," (August 1985
       Draft), pp. 1-10.

6-26   Fred  C. Hart Associates, Inc.
7-1
7-2
7-3
                       SECTION 7.0 SECONDARY CONTAINMENT
Typical Observation Well
Installation
Typical U-Tube Placement
Detail:  Secondary Containment
  for Aboveground Tank
7-13   Adapted from New York State
       Department of Environmental
       Conservation, "Technology for
       the Storage of Hazardous
       Liquids - A State-of-the-Art
       Review"(January, 1983).

7-14   Adapted from New York State
       Department of Environmental
       Conservation, "Technology for
       the Storage of Hazardous
       Liquids - A State-of-the-Art
       Review" (January, 1983).

7-20   Fred C. Hart Associates, Inc.

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                                             OSWER Policy Directive No. 9483.00-1
                                         F-4
                             Appendix F (Continued)

                                 FIGURE SOURCES
         TITLE
7-7
7-8


7-9
7-10



7-11


7-12


7-13
         Tank With External Liner

         New Aboveground Tank

         Multiple Tanks in a Vault
                                 PAGE   SOURCE
Double-Wai led Tank
  Configurations
Cross Sectional View of a
  Double-Walled Tank

Typical Earthen Dike
  Construction
Intersection of Flexible
  Membrane Trench Liner and
  Tank Excavation Liner

Waterproofing at Corner of
  Vault Base

Tank Wrapped in Flexible
  Membrane

Example Containment Structure
  for Pump and Valve Installa-
  tion
7-22   Fred C.  Hart Associates,  Inc.

7-23   Fred C.  Hart Associates,  Inc.

7-24   U.S. Environmental  Protection
       Agency,  Office of Solid Waste,
       "Interim Prohibition: Guidance
       for Design and Installation of
       New Underground Storage Tanks"
       (August  1985 Draft),  p. 1-24

7-25   U.S. Environmental  Protection
       Agency,  Office of Solid Waste,
       "Interim Prohibition: Guidance
       for Design and Installation of
       New Underground Storage Tanks"
       (August  1985 Draft),  P. 1-19.

7-26   Fred C.  Hart Associates,  Inc.
7-28   Petroleum Association for
       Conservation of the Canadian
       Environment, (Handling Com-
       mittee,  PACE Report No. 80-3,
       PACE Product Storage and
       Handling Committee, Ottawa,
       Canada,  1980) "Bulk Plant
       Design Guidelines for Oil
       Spill  Prevention and Control."

7-30   Fred C.  Hart Associates, Inc.
7-40   Fred C.  Hart Associates,  Inc.
7-46   Fred C.  Hart Associates,  Inc.
7-49   Fred C.  Hart Associates,  Inc.
7-14     Double-Walled Pipe System
                                 7-52   Fred C.  Hart Associates,  Inc.

-------
                                            OSWER Policy Directive No.  9483.00-1
                                        F-5
                            Appendix  F  (Continued)

                                 FIGURE  SOURCES
FIGURE   TITLE
                                 PAGE    SOURCE
       SECTION  9.0 CONTROLS AND PRACTICES TO PREVENT SPILLS AND OVERFILLS
9-1
9-2
Tape Float Gauge for  Under-
  ground Storage Tanks
Float Vent Valves
9-3
9-4
Optical  Liquid LeveT  Sensing
  System for Bulk Storage
  System
Types of Valves - Example One    9-15
9-5
Types of Valves - Example Two    9-16
9-6
Check Valves Used to Prevent
  Backflow
9-7    Dover Corp.,  Bulletin OLLS
       6-80, "Optic  Liquid Level
       Sensing System for Petroleum
       Transportation and Storage
       Applications" (June 1980).

9-8    Dover Corp.,  Bulletin OLLS
       6-80, "Optic  Liquid Level
       Sensing System for Petroleum
       Transportation and Storage
       Applications" (June 1980).

9-12   Dover Corp.,  Bulletin OLLS
       6-80, "Optic  Liquid Level
       Sensing System for Petroleum
       Transportation and Storage
       Applications" (June 1980).

       Training manual  prepared by
       Pace Company  Consultants nd
       Engineers,  Inc.,  for the
       Environmental Protection
       Agency under  Grant No.
       T-900-175-02-2 (Houston,
       Texas:  Rice  University,
       1975).

       Training Manual  prepared by
       Pace Company  Consultants and
       Engineers,  Inc.,  for the
       Environmental Protection
       Agency under  Grant No.
       T-900-175-02-2 (Houston,
       Texas:  Rice  University,
       1975).

9-17   R.H. Perry and C.H. Chi 1 ton,
       Chemical Engineers Handbook,
                                                 5th ed.  (New
                                                 Hill,  1973)
                                                     York,  NY:   McGraw

-------
                                             OSWER Policy Directive No.  9483.00-1
                                        F-6
                             Appendix  F  (Continued)

                                 FIGURE  SOURCES
9-8
9-9
9-10




9-11

9-12




9-13

9-14

9-15

9-16

9-17
         Cross Sections  of Check. Valves
Types of Couplings
Elements of an Overfill
  Prevention System
Chain and Tape Float Gauges
  Used for Level  Control
Level and Shaft Float Gauges

Magnetically Coupled Floats




Flexure Tube Displacer

Magnetically Coupled Displacer

Torque Tube Displacer

Bubble Tube System

Loading Arm Equipped With
  Automatic Shutoff
                                 PAGE

                                 9-18
                                                 SOURCE
9-20
9-23
9-27




9-28

9-29




9-31

9-32

9-33

9-35

9-38
American Petroleum Institute,
Guide for Inspection of
Refinery Equipment, or
"Chapter XI - Pipe, Valves,
and Fittings," 2nd Ed. (1974)

Dover Corp., Bulletin OLLS
6-80. "Optic Liquid Level
Sensing System for Petroleum
Transportation and Storage
Applications" (June 1980).

Dover Corp., Bulletin OLLS
6-80. "Optic Liquid Level
Sensing System for Petroleum
Transportation and Storage
Applications" (June 1980).

R.H. Perry and C.H. Chi 1 ton,
Chemical Engineers Handbook,
5th ed. (New York, NY:  McGraw
Hill, 1973).

Chemical Engineers Handbook

Magnetrol International,
Inc., Bulletin 44-117, "Mag-
netrol Liquid Level Controls,"
p. 84.

Chemical Engineers Handbook

Chemical Engineers Handbook

Chemical Engineers Handbook

Chemical Engineers Handbook
Emco Wheaton, Inc., "Fluid
Handling Systems," Catalog
7- 8/73 (revised April, 1977).

-------
                                            OSWER Policy Directive No. 9483.00-1
                                        F-7
                            Appendix F (Continued)

                                FIGURE SOURCES
FIGURE   TITLE
                                         PAGE   SOURCE
                           SECTION  10.0 INSPECTIONS
10-1      Areas  of  Concern  in a Typical
           Tank Foundation
                                          10-14  Maryland Department Of  Health
                                                and Mental Hygiene,"Toxic
                                                Substance Storage  Tank  Con-
                                                tainment Assurance nd Safety
                                                Program Guide and  Procedures
                                                Manual," (September 1983),  p.
                                                5-28.
          Section  13.0  PROCEDURES  FOR TANK SYSTEMS THAT STORE OR TREAT
                  IGNITABLE, REACTIVE,-OR INCOMPATIBLE WASTES
13-1      40 CFR 261.21  Characteristics
           of Ignitability,  and  40 CFR
           261.23 Characteristics of
           Reactivity

13-2      40 CFR 264.17  General Require-
           ments for Ignitable,  Reactive
           or Incompatible Wastes

13-3      Compatibility  Matrix
                                         13-3   Code of Federal Regulations
                                          13-4   Code of Federal Regulations
                                          13-29, Hatayama, et al., A Method for
                                          30     Determining the Compatibility
                                                of Hazardous Waste, U.S. EPA,
                                                1980

-------
        OSWER Policy Directive No. 9483.00-1
APPENDIX G

-------
     DRAFT
                          METHOD 9090              '        ^  -






        COMPATIBILITY  TEST FOR WASTES AND MEMBRANE LINERS






1.0  Scope and  Application



     1.1  Method  9090  is  intended tor use in determining the



effects of chemicals  in a surface impoundment, waste pile,  or



landfill on the physical  properties of flexiole membrane liner



(FML)  materials intended  to contain them.  Data from these  tests



will assist in  deciding whether a aiven liner material is accept-



able for the intended  application.



2 . 0  Summary of Method



     2.1  IT. order  to  estimate waste/liner compatibility, the



liner  material  is  immersed in the chemical environment for  mini-



mum periods of  120  days- at room temperature (23 +_ 2°C) and  at



50  _+ 2°C.    In  cases where the FML will be used in a chemical



environment at  elevated temperatures, the immersion testing



shall  be run at tne elevated  temperature if it is expected  to  be



hiqher than 50°C.   Whenever possible, the use of longer exposure



times  is recommended.  A  comparison of the membrane's physical



properties -neasuted periodically before and after contact with



the waste  fluid is  used to estimate the compatibility of the



liner  when exposed  to  the waste over time.



3.0  Interferences   (Not  applicable)



4.0  Apparatus  and  Materials



     4.1  Exposure  tanks  of a size sufficient to contain the



samples with provisions for supporting the samples so that  they



do  not touch the  bottom or sides of the tank, or each other,  and

-------
toe stirring the liquid in the tank.  The tanks should be compat-



ible with the waste fljia and impermeable to any of tne constitu-



ents they are intended to contain.  The tank snail be equipped



with a means of maintaining the solution at temperatures of c oorn



temperature  (23 +_ 2°C) and 5U _+ 2°C ana for preventing evapora-



tion of the solution  (e.g./ covei equipped with a retlux conaenser



or seal the tank with a teflon gasket and use an airtight cover)



with both sides of the liner material exposed to the chemical



environment.  The pressure inside the tank must be the same as



that outside the tank.  It the liner has a side that (1) is not



exoosed to the waste  in actual use and (2) is not designed to



withstan.a exposure to the chemical environment, then such a



liner  may be treated with only the barrier surface exposed.



Def init ions :



     1.  Sample - a representative piece of the liner material




                  proposed for use that is of sufficient size



                  to allow for the removal of all necessary



                  specimens.



     2.  Specimen - a piece of material, cut from a sample, appro-



                    priately shaped and prepared so that it is



                    ready to use for a test.



     4.2  Stress-strain machine suitable for measuring elongation,



tensile strength, tear resistance, puncture resistance, modulus




of elasticity, and ply adhesion.



     4.3  Jig for testing puncture resistance for use with FTMS



101C,  Method 2065.

-------
     4.4  Liner sample labels and holders made of materials known

to be resistant to the specific wastes.

     4.5  Oven at 105 +_ 28C.

     4.6  Dial micrometer.

     4.7  Analytical balance.

     4.8  Apparatus for determining extractable content of liner

          ma tecials.

Note:  A minimum quantity of representative waste fluid necessary
       to conduct this test nas not been specified in this netr.oc
       because the amount will vary depending upon the waste co~i-
       Dosition and the type ot lir.ec material.   For example,
       certain organic waste constituents/ if present in the rep-
       resentative waste fluid, can be absorbed by the liner
       material, thereby changinq the concentration of the chem-
       icals in the waste.   This change in waste composition may
       require the wastre fluid to be replaced at least monthly in
       order to maintain representative conditions in the waste
       fluid.  The amount ot waste .fluid necessary to maintain
       representative waste conditions will depend on factors
       such as the volume of constituents absorbed by the spe-
       cific liner material and the concentration of the chem-
       ical constituents in the waste.

5.0  Reagents  (Not applicable)

6.0  Sample Collection, Preservation, and Handling

     6.1  For information on what constitutes a representative

sample of the waste fluid, the following guidance document should

be referred to:

   Permit Applicants' Guidance Manual for Hazardous Waste Land
   Treatment, Storage, and Disposal Facilities; Final Draft;
   Chp.5, pgs.15-17, Chp.6, pgs.18-21, and Chp.8, pgs. 13-16,
   May 1934.

7.0  Procedure

     7.1  Obtain a representative sample of the waste fluid.  If

a waste sample is received in more than one container, blend

thoroughly.  Note any signs of stratification.  If stratification

exists, liner samples must be placed in each of the phases.  In

-------
cases where the waste tluid is expected to stratity and the phases



cannot oe separated, the number: of immersed samples pe: exposure



period can be increased (e.g., if the waste fluid has two phases



then 2 samples per exposure period ace needed) so that test samole



exposed at each level of the waste can be tested.  If the waste



to be contained in t.ie land disposal unit is  in solid form,



generate a synthetic leachate.^



     7.2  Perform the followina tests on unexposed samples of



the polymeric membrane liner material at 23 _+ 2°C and 50 ^ 2°C.2'3



Tests for tear resistance and tensile properties are to oe per-



formed according to the protocols referenced  in Table 1.  See



Figure 1 for cutting patterns for nonreinforced liners, Figure 2



for cutting patterns for reinforced liners, and Figure 3 for



cutting patterns for semicrystalline liners.



     1.  Tear  resistance,  machine and transverse directions,



         three specimens each direction for nonreinforced liner



         materials only.  See Table 1 for appropriate test method,



         the recommended test speed,  and the values to be reported



     2.  Puncture resistance, two specimens, FTMS 101C, Method



         2065.  See Figure 1, 2,  or 3, as applicable, for sample



         cutting patterns.



     3.  Tensile oroperties, machine and transverse directions,



         three tensile specimens  in each direction.  See Table 1



         for appropriate test method,  the recommended test speed,



         and the values to be reported.  See  Figure 4 for tensile



         dumbbell cutting pattern dimensions  for nonreinforced



         liner samples.



     4.  Hardness, three specimens, Duro A (Duro D if Duro A

-------
























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-------
 A
10'
                                                Transverse direction
            Puncture test
                                 Tear test specimens
                                                    Volatiles test specimen
     Tensile test specimens
                                                               .  Not to cole
       Figure 1 .  Suggested pattern for cutting test  specimens from
                  , nonrelnforced crossllnked or thermoplastic  Immersed
                   liner samples.

-------
                                       Volatile* test specimen
Puncture test specimens

                                 adhesion test specimens
       l^l ^^^®^si7r^
gJ"^_-S'V*ft' j*yr*^J>*?._?        	  1_. - .. I. - - —  -'• - -   ^> r ~ ^
/"-O^»£^:3;£K.-ir. -"-;.v-.^ "rW-,:-T-i:-^" --"i.li

                                                    Not co scale
 Figure 2 .  Suggested pattern for cutting test specimens from
           fabric reinforced Immersed liner  samples.  Note: To
           avoid edge effects, cut specimens 1/8 -  1/4 Inch in
           from edge of Immersed sample.

-------
                  Modulus  of elasticity
                     test  specimens
      Tensile test specimens
                                    VolatHts test specimen
                                                   ..•*;• ^-psz..} ;^r^ -J
                                                   *—-^?i r,S?V^.-.l
                                                   •^3-&&&*&£
                       test specimens
                                                            Not to scale
Figure 3 .   Suggested pattern for cutting  test  specimens  from
            semicrystal! 1ne Immersed Hner samples.   Note: To
            avoid edge effects, cut specimens 1/8  -  1/4  Inch
            1n from edge of Immersed sample.

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                               G

                               L •

                               O •

                              LO-
       W  -  Width  of  narrow  section       0.25  Inches
       L  -  Length of narrow section      1.25  inches
      WO  -  Width  overall                0.625  inches
      LO  -  Length overall                3.50  inches
       G  -  Gage  length                   1.00  inches
       0  -  Distance  between grips        2.00  inches
Figure 4 .   Die for tensile dumbbell  (nonreinforced
            liners) having  the  following  dimensions.

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         reading is greater than 80), ASTM D2240.  The hardness



         specimen thickness for Duro A is 1/4 in. and tot Duto D



         is 1/3 in.  The specimen dimensions ace 1 in. oy 1 in.



     5.  Elongation at break.   This test is only to be performed



         on membrane materials that do not have a fabr ic or



         other nonelas tomer ic support as part of the liner..



     6.  Modulus of elasticity, machine and transverse directions,



         two specimens each direction for semicrystalline liner



         materials only, ASTM D882 modified Method A (see Table 1),



     7.  Volatiles content, SW 870 Appendix III-D.



     8.  Extractables content, SW 870 Appendix III-E.



     9.  Specific gravity, three specimens, ASTM D792 Method A.



    10.  Ply adhesion,, machine and transverse Directions, two



         specimens each direction for fabric reinforced liner



         materials only, ASTM D413 Machine Method, Type A - 180



         degree peel.




    11.  Hydrostatic resistance test, ASTM D751 Method A, Pro-



         cedure 1.



     7.3  Cut five pieces of the lining material for each test



condition of a size to fit the sample holder, or at least 8 in. by



10 in.  The fifth sample is an extra sample.  Inspect all samples



for flaws and discard unsatisfactory ones.  Liner materials with



fabric reinforcement require close inspection to ensure that



threads of the samples are evenly spaced and straight at 90°.



Samples containing a fiber scrim support may be floodcoated



along the exposed edges with a solution recommended by the liner



manufacturer or another procedure should be used to prevent the



scrim from being directly exposed.  The flood coating solution

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will tyoically contain 5-151 solids dissolved  in a solvent.  The



solids content can be the liner formula or the base polymer.



Measure tne -fol lowing :



    1.  Gauge thickness, in. - average of the  four corners.



    2.  Mass, Ib. - f.o one-hundretn of a Ib.



    3.  Lengtn, in. - average of the lengths of the two sides plus



        the length measures through the liner  center.



    4.  Width, in. - average of the widths of  the  two ends  plus



        the width measured through the liner center.



Do not cut tnese liner samples into the test specimen shapes



shown in. Figures 1, 2, oc 3 at this time.  Test specimens will  be



cut as specified in 7.7, after exposure to the waste fluid.



     7.4  Label the liner samples (e.g., notch or  use metal sta-



ples to identify the sample) and hang in the waste fluid oy a



wire hanger or a weight.   Different liner materials should be



immersed in separate tanks to avoic exchange of plasticizers and



soluble constituents when plasticized membranes are being tested.



Expose the liner samples to the stirred waste  fluid held at room



temperature and 50 _+ 2°C.



     7.5  At the end of 30, 60, 90, and 120 days of exposure,



remove one liner sample from each test condition to determine



the membrane's physical properties (see 7.6 ar.d 7.7).  Allow the



liner sample to cool in the waste fluid until  the waste fluid has



a stable room temperature.  Wipe off as much waste as possible

-------
and rinse briefly with water.  Place wet sample in a labeled



polyethylene bag or aluminum foil to prevent tne sample from



drying out.  The liner sample should be tested as soon as possi-



ble after removal trom the waste tluid at room temperature, but



in no case later than 24 hours after removal.



     7.6  To test tne immersed sample, wipe off any remaining



waste and rinse with  :e ionized water.  Blot sample dry ana



measure the following as in 7.3.



   1.  Gauge thickness, in.




   2.  Mass, lb.



   3.  Length,  in.



   4.  Uidth, in.



     7.7  Perform the following- tests on the exposed samples. ^r3



Die cut test specimens following suggested cutting patterns.    ,



Tests for tear  resistance and tensile properties are to be



performed according to the protocols referenced in Table  1.



See Figure 1 for cutting patterns for nonreinforced liners,



Figure 2 for cutting patterns for reinforced liners, and  Figure  3



for sem ic r ys ta 11 me liners.



   1.  Teat resistance, machine and  transverse directions,  three



       specimens each direction for materials without  fabric



       reinforcement.  See Table 1 for appropriate test method,




       the recommended test specimen and speed of test, and the



       values to be reported.



   2.  Puncture  resistance, two specimens, FTMS 101C,  Method 2065



       See Figure 1,  2, or 3, as applicable, for sample cutting



       patterns .




   3.  Tensile  properties, machine and transverse directions,

-------
       three specimens each direction.  See Table 1 for appro-



       priate test method, the r ecommended test specimen and



       speed of test, and the values to be reported.  See Figure



       4 to: foe tensile dumbbell cutting pattern dimensions tor



       nonce in forced liner samples .



   4.  Hardness, three specimens, Duro A (Duro D if Duro A reaciny



       is greater  than 30), ASTM D2240.  The hardness specimen



       thickness for Duro A is 1/4 in. ana tor Ouro 0 is 1/8 in.



       The specimen dimensions are 1 in. by 1 in.



   5.  Elongation  at break.   This test is only to be per£o:~ed



       on membrane materials that do not have a fabric or other



       nonelastomeric support as part of the liner.



   6.  Modulus of  elasticity, machine and transverse directions,



       two specimens each direction for sen iceystal1ine Liner



       materials only,  ASTM D832 modified Method A (see Table 1).



   7.  Volatiles content, SW 870 Appendix III-D.



   8.  Extractables content, SW 870  Appendix III-E.



   9.  Ply adhession, machine and transverse directions, two



       specimens each direction for  faoric reinforced liner



       materials only,  ASTM 0413 Machine Method, Type A - 180



       degree peel.



  10.  Hydrostatic resistance test,  ASTM D751 Method A, Procedure 1



     7.8  Results  and reporting



     7.8.1  Plot the curve for each property over the time period



0 to 120 days and  display the spread in data points.



     7.8.2  Report all raw, tabulated, and plotted data.  Recom-



mended methods for collecting and presenting information is




described in the documents listed under 6.1, ana related agency

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guidance manuals.



     7.3.3  Summarize the caw test results as tollows:



   1.  Percent chance in thickness.



   2.  Percent change in mass.



   3.  Percent change in area (provide length and width dimensions)



   4.  Percent retention of physical properties.



   5.  Change, in points, of hardness reading.



   6.  Calculate the modulus of elasticity (pounds-force per



       square inch) .



   7.  Percent volatiles of unexposed and exposed liner material.



   8.  Percent extractables of unexposed and exposed liner material




   9.  Determine the adhesion value  in accordance with ASTM D413



       section 12.2.



  10.  Report the pressure and time  elapsed at the first



       apoearance of water through the flexible membrane



       liner for the hydrostatic resistance test.



8 . 0  Quality Control



     8.1  Determine  the mechanical properties of identical



nonimmersed and immersed liner samples in accordance with the



standard methods for the specific physical property test.



Conduct mechanical property tests on nonimmersed and immersed



liner samples prepared from the same sample or lot of material



in  the same manner and run under identical conditions.  Test



liner samples immediately after they are removed from the room



temperature test solution.
1)  For the generation of a synthetic leachate, the Agency suy-

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                                10
    gests the use of the Toxicity Chat ac tec 1st ic Leaching Proce-



    dure (TCLP)  that was proposed in the Federal Register on Jur.e



    13,  1936, Vol.  51,  N'o.114, pg .  21685.



2)   Foe  semicrystal1ine membrane liners, the Agency suggests the



    determination of the potential  for environmental stress



    cracking.  The  test that can be used to make this determinatio:



    is either ASTM  D1693 or the National Bureau of Standards



    Constant Tensile Load.    The evaluation of the results should



    be provided  by an expert in this tield.



3)    For field seams, the Agency suggests  the determination of



     seam strength  in shear and peel modes.  To determine seam



     strength in peel mode  the test ASTM D413 can be used.  To



     determine seam strength in shear mode for nonreinforced FMLs,



     the test AST'l  D3083 can be used and for reinforced FMLs,



     the test ASTM  0751, Grab Method, can  be used at a speed of



     12  inches per  minute.    The evaluation of the results should



     be  provided by an  expert in this tield.

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                                11
        TABLE 2. POLYMERS USED IN FLEXIBLE MEMBRANE LINERS










Thermoplastic Materials (T?)



CPE (Chlorinated polyethylene)8



     Family ot polymers produced by chemical reaction of chlorine



     or. polyethylene.  The resulting thermoplastic elastomers



     contain 25 to 451 chlorine by weight and 0 to 25% crystal-




     11 n i t y .



CSPE (Chlorosu1fonatea polyethylene)3



     Family of polymers that are produced by polyethylene reacting



     with chlorine and -sulfur dioxide and usually containing



     25 to 43% chlorine and 1.0 to 1.4% sulfur.  Chlorosulfonatec



     polyethylene is also known as hypalon.




EIA (Ethyler.e inter polymer alloy)3



     A blend of EVA and polyvinyl cnloride resulting  in a thermo-



     plastic elastomer.



?VC (Polyvinyl chloride)3



     A synthetic thermoplastic polymer made by polymerizing vinyl



     chloride monomer, or vinyl chloride/vinyl acetate monomers.



     Normally rigid and containing 50% of plasticizers.




PVC-CPE (Polyvinyl chloride - chlorinated polyethylene alloy)3




     A blend of polyvinyl chloride and chlorinated polyethylene.



TN-PVC (Thermoplastic nitrile-polyvinyl choloride)3




     An alloy of thermoplastic unvulcanized nitrile rubber and



     polyvinyl chloride.

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                                 12
TABLE 2. (Continued!
Vulcanized .".aterials  (XL)

Butyl ruboe: a

     A synthetic rubber based or.  isobutylene and a small anour.t

     of isoprene to provice sites foe vulcanization..

EPDM (Ethylene propylene dien.e monomer }3/^

     A synthetic elastomer oasea on ethylene, ptopylen.e, and  a

     snail amount of none or. jugated dien.e  to provide sites  for

     v u 1 c a.-. i za 11 o n .

CM   (Crossl inkea chlorinated polyethylene)

     N'o definition available by EPA.

CO, ECO (Epichlorohydrin polymers)3

     Synthetic rubber including two epichlorohydrin-based  elasto-

     mers which are saturated, high molecular weight aliphatic

     polyethers with chloromethyl side chains.  The two types

     include homopolymer (CO and a copolymer of epichlorchydrin

     and ethylene oxide (ECO).

CR (Polychloroprene)a

     Generic name for a synthetic rubber  based primarily on

     chlocobutadiene.  Polychloroprene is also known as neoprene.
     aAlso supplied reinforced with fabric.
     bAlso supplied as a thermoplastic.

Semicrystal1ine Materials (CX)

HOPE (High density polyethylene)

     A polymer prepared by the low-pressure polymer i zaton of

     ethylene as the principal monomer.

-------
                                13
TABLE 2. (Continued,
HOPE - A  (High density polyethylene/rubber alloy)



       A blend of high-density polyethylene and rubber.



LLDPE (Linear low-density polyethylene)



      A low-density polyethylene produced by the copolymer i-



      zation of ethylene with various alpha olefins in the pres-



      ence of suitable catalysts.



PEL (Polyester elastomer)



     A segmented thermoplastic copolyester elastomer containing



     recurring long chain ester units derived from dicarboxylic



     acids and long chain glycols and short chain ester units



     derived from dicarboxylic acids and low molecular weight



     d iols.



PE-EP-A (Polyethylene echyiene/propylene alloy)



     A blend of polyethylene and ethylene and propylene polymer



     resulting in a thermoplastic elastomer.



T-EPDM (Thermoplastic EPDM)



     An ethylene-propylene diene monomer blend resulting in a



     thermoplastic elastomer.

-------
                                             OSWER Policy Directive No.  9483.00-1
                                             Bibliography Page  1.
                                  BIBLIOGRAPHY
 1.  Aluminum Association,.  ,"Aluminum  Standards -and Data,  1970-71,"  AA-ASD-1
    (1984).

 2.  Aluminum Association, "Engineering  Data for Aluminum Structures,"  AA-ED-33
    (1981).

 3.  Aluminum Association,  "Specifications  for Aluminum Structures,"  AA-SAS-30
    (1982).

 4.  American Concrete Institute,  "Specifications  for  Structural  Concrete  for
    Building,"  ACI-301-84 (1984).

 5.  American Concrete  Institute,   "Building  Code  Requirements  for  Reinforced
    Concrete,"  ACI-318R  (1983).

 6.  American  Concrete   Institute,   "Design  and   Construction   of   Circular
    Prestressed Concrete  Structures," ACI-344R-70  (1970).

 7.  American Concrete  Institute,   "Concrete  Sanitary Engineering  Structures,"
    ACI-350R-77 (1983).

 8.  American Concrete Institute,  "Concrete Sanitary  Engineering  Structures,"
    ACI-350R-83 (1983).

 9.  American Concr?^   Institute,   "A   Guide   to   the  Use   of   Waterproofing,
    Dampproofing,  Protective  and   Decorative  Barrier  Systems  for  Concrete,"
    ACI-515.1R-79  (1984).

10.  American Concrete  Institute,   "Manual  of  Concrete Inspection,"  4th  Ed.,
    (1981).

11.  American Iron  and  Steel   Institute,   "Steel  Tanks  for  Liquid  Storage,"
    AISI-TS-291-582-10M-NB  (1982).

12.  American Iron and  Steel  Institute,  "Useful  Information on  the Design  of
    Plate  Structures," AISI-PS-268-685-5M  (1985).

13.  American  National   Standards    Institute,   "Petroleum   Refinery   Piping,"
    ANSI/ASME Standard B31.3  (1984).

14.  American National  Standards  Institute,  "Liquid  Petroleum  Transportation
    Piping Systems,"  ANSI Standard  831.4 (1980).

15.  American National  Standards  Institute,  "Standard for Welded  Aluminum-Alloy
    Storage Tanks,"  ANSI  B96.1  (1981).

16.  American Petroleum  Institute,   "Specification  for Field  Welded Tanks  for
    Storage of  Production Liquids," 8th  Ed., API  12D (1982).

-------
                                             OSHER Policy Directive No.  9483.00-1
                                             Bibliography Page  2.


17.  American Petroleum Institute, "Specification  for  Bolted  Tanks for  Storage
    of Production Liquids,"  12th  Ed.,  API  12B (1977).

18.  American  Petroleum  Institute,  "Specification for  Shop  Welded  Tanks  for
    Storage of Production  Liquids,"  7th  Ed.,  API  12F  (1982).

19.  American   Petroleum   Institute,  "Recommended    Rules   for   Design   and
    Construction of  Large,  Helded,  Low-Pressure  Storage Tanks,"  API  Standard
    620 (1982).

20.  American Petroleum Institute, "Welded  Steel  Tanks  for Oil,"  API  Standard
    650 (Revised 1984).

21.  American  Petroleum   Institute,  "Recommended  Practices  for  the  Pressure
    Testing of Liquid Petroleum Pipelines," 2nd Ed.,  API RP 1110 (1981).

22.  American Petroleum  Institute,  "Recommended  Practices for  Abandonment  or
    Removal of Used Underground Service  Station Tanks,"  API 1604 (1981).

23.  American  Petroleum  Institute,   "Installation   of   Underground  Petroleum
    Storage Systems," API  1615 (1979).

24.  American Petroleum Institute, "Underground Spill   Cleanup Manual,"  API  1628
    (1980).

25.  American Petroleum  Institute, "Cathodic Protection  of Underground  Storage
    Tanks and Piping Systems," API 1632  (1983).

26.  American  Petroleum  Institute,   "Venting   Atmospheric   and   Low-Pressure
    Storage Tanks," API  Standard 2000  (1982).

27.  American Petroleum Institute, "Protection  Against Ignitions Arising Out of
    Static, Lightning, and Stray Currents," 4th Ed.,  API RP 2003 (1982).

28.  American Petroleum Institute, "Cleaning Petroleum Storage Tanks,"  API  2015
    (1985).

29.  American  Petroleum  Institute,  "A Guide  for  Controlling  the  Lead Hazard
    As-sociated With Tank Entry and Cleaning," API  2015A  (1985).

30.  American Petroleum Institute, "Cleaning Open-Top  and Covered  Floating-Roof
    Tanks," API 201 SB (1981).

31.  American   Petroleum  Institute,   "Guide   for   Inspection  of   Refinery
    Equipment," (1981).

32.  American Society of  Mechanical Engineers,  "ASME Boiler and  Pressure Vessel
    Code," ASME BPV-VIII-1  (1980).

33.  American  Society for Testing  and  Materials,  "Standard  Specification  for
    Filament-Wound Glass-Fiber  Reinforced  Thermoset  Resin  Chemical  Resistant
    Tanks," ASTM D 3299  (1981).

-------
                                             OSWER Policy Directive No. 9483.00-1
                                             Bibliography Page 3.


34. American  Society  for  Testing  and  Materials,  "Standard  Specification  for
    Glass-Fiber  Reinforced  Polyester  Underground  Petroleum  Storage  Tanks,"
    ASTM D 4021 (1981).

35. American Society for Testing and  Materials,  -"Proposed Guide-for- Estimating
    the Incompatibility of  Selected Hazardous  Wastes Based on  Binary Chemical
    Reactions," Proposal  P-168 ASTM 0-34,(1986).

36. American  Water  Works  Association,  "Standard  for  Welded  Steel  Tanks  for
    Water Storage,"  AWWA-D100 (1984).

37. Anderson,  N.A.,  "Instrumentation  for Process Measurement  and Control,"  2nd
    Ed., (1972).

38. Grundmann, Werner,  "PALD-2  Underground Tank Leak Detector  and Observation
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39. Hatayama et al.,  "A  Method  for Determining the  Compatibility  of Hazardous
    Wastes," EPA 600/2-80-76 (1980).

40. Hinchman Company,  "Suggested  Ways  to  Meet Corrosion  Protection  Codes  for
    Underground Tanks  and Piping,"  (1981).

41. Levine   and   Martin,    "Protecting    Personnel    at    Hazardous   Waste
    Sites,"(1985).

42. Maryland  Department  of  Health   and   Mental  'Hygiene,  "Toxic  Substances
    Storage  Tank   Containment   Assurance   and   Safety  Program,   Guide   and
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43. Merck, "The Merck  Index," 10th  Ed.,  (1983).

44. National Association of  Corrosion  Engineers,  "Recommended Practice-Control
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    Systems,"  NACE RP-01-69 (1983).

45. National    Association     of     Corrosion     Engineers,     "Recommended
    Practice - Mitigation  of Alternating  Current  and  Lightning  Effects   on
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46. National Association of  Corrosion  Engineers,  "Recommended Practice-Control
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47. National Institute of  Occupational  Safety  and Health, "Working in Confined
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48. National Fire Protection Association,   "Flammable  and  Combustible Liquids,"
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49. National  Fire Protection Association,  "National   Electrical  Code," NFPA 70
    (1984).

-------
                                             OSHER Policy Directive No.  9483.00-1
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50.  National   Fire  Protection  Association,   "Static   Electricity,"   NFPA  77
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51.  National  Fire Protection Association,  "Lightning Protection Code,"  NFPA  78
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52.  National  Fire Protection Association,  "Standard Procedures for Cleaning  or
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53.  National   Fire  Protection  Association,  "Loading  and  Unloading   of  Tank
    Vehicles," NFPA 385 (1985).

54.  National   Fire  Protection Association,  "Fire  Protection  Guide  on  Hazardous
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56.  Owens-Corning,   "Fiberglas    Underground    Tank   Installation   Techniques
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57.  Perry, R.H., C.H.  Chilton,  "Chemical Engineers'  Handbook," (1973).

58.  Petroleum Equipment Institute,  "Recommended Practices for  Installation  of
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59.  Pludek, V.R., "Design and Corrosion Control," (1977).

60.  Portland   Cement Association,  "Effects  of Substances  on  Concrete  and Guide
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63.  Prestressed Concrete Institute,  "Guide Specification  for Prestress  Precas
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64.  Sax,  N.I.,  "Dangerous  Properties  of  Industrial   Materials,"  6th  Ed.
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67.  Underwriters Laboratories,   Inc.,  "Standard  for  Steel Inside Tanks  for C
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-------
                                             OSWER Policy Directive No. 9483.00-1
                                             Bibliography Page 5.


 68. Underwriters Laboratories, Inc., "Standard for  Steel  Aboveground  Tanks for
    Flammable and Combustible Liquids," UL 142 (1984).

 69. Underwriters  Laboratories,   Inc.,   "Standard   for  Glass-Fiber-Reinforced
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