U.S. Environmental Pro*ed;on
Region 5, Librar' "•/( -<'J)
77 West Jackson Su::^^, 12th Floor
Chicago, IL 60604-3590
-- Environment*! Protection
&EPA
0«ic» of
Solid W«sia and
fl«K>ont»
DIRECTIVE NUMBER:
9483.00-1
TITLE: Technical Resource Bocument for the Storage
and Treatment of Hazardous "SCaste in Tank Systems
APPROVAL DATE: December 1986
EFFECTIVE DATE: December 1986
ORIGINATING OFFICE: office of solid Waste
S3 FINAL
D DRAFT
STATUS:
REFERENCE (other documents):
[ ] A- Pending OMB approval
[ ] B- Pending AA-OSWER approval
[ ] C- For review. &/or comment
[ ] D- In development or circulating
headquarters
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» I
v EPA
. .
Washington iX. 20460
OSWER Directive Initiation Request
>r..
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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 2Q460
December 1986
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TABLE OF CONTENTS
Table of Contents i-vi i
List of Figures
List of Tables
List of Acronyms
EXECUTIVE SUMMARY
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
8) 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)
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
B) Soil Resistivity 5-31
C) Soil Sulfides Level 5-33
D) Soil pH 5-33
E) Structure-to-Soil 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)
0
D)
Qualified,
Engineers ,
Inspection
Regi stered
Procedures
6.2
6.3
6.8
Independent,
Professional
Installation
Repairs
Backfi11i 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 Points
7.0 SECONDARY CONTAINMENT SYSTEMS AND RELEASE DETECTION
Secondary Containment Implementation Schedule
Properties of a Secondary Containment System
Design Parameters
A)
B)
C)
0)
Types
Liner
Compatibility and Strength .................
Foundation Integrity .......................
Leak Detection Capability ..................
1) Tank Excavation Monitoring Systems .....
2) Leak Sensors ...........................
3) Interstitial Monitoring (Leak Detection)
Adequate Drainage ..........................
of Secondary Containment .................
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 .
5-53
5-55
6-1
6-2
6-3
6-3
6-7
6-13
6-13
6-14
6-18
6-18
6-19
6-19
6-20'
6-23
6-27
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
ii
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TABLE OF CONTENTS (Continued)
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 Haste 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)
Page
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
D) Procedures for Abandoning Onground, Inground,
Aboveground Tanks in Place 12-10
E) Procedures for Preparation for Removal and
Di sposal 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
8) 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 Points 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 Mechani sms 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 Page
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 Double-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 Diiplacer 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 Ignitability,
and 40 CFR 261.23 Characteristics of
Reactivity 13-3
13-2 40 CFR 264.17 General Requirements for
, Ignitable, Reactive or Incompatible Wastes ... 13-4
e
13-3 Compati bi 1 i ty Matri x 1 3-29, 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 Art 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 Wai 1 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
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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 Requirement's 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
1'3-10 List of Chemical Representatives by Class 13-25
13-11 Storage Tank Decontamination Methods 13-32
x1 i i
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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
k.Pa 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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Policy Directive No. 9483.00-!
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 Waste 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
3
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 6 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 No. 9483.00-1
5
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
the handling, storage or treatment of the
protective distances betwee-n the storage
streets and alleys.
Appendices include information on
documents, applicable technical document
Also provided is a checklist (Appendix A)
can verify compliance with the regulatory r
recautions that should be taken in
e wastes, such as establishment of
r treatment tank and public ways,
pertinent EPA technical resource
and tank-specific definitions.
against which the owner or operator
quirements.
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OSHER Policy Directive No. 9483.00-1
.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 (40CFR270). 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 specifically 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 J) 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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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 270.16, 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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(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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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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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 Containment 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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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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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. BNA,
Environment Reporter. Dec. 28, 1984, 71:3101.
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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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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 in 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 264 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 B application that
support the specific Information requirements of 270.16 and the general
information requirements in 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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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
270.16U)
270.16(b)
270.16(c)
270J6(d)
270.16(e)
270.16(f)
270.16(g)
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
264.191(a)(b)(c)(d)
264.192(a)
None
None
None
264.192(a)(3)
equipment for corrosion protection
New tank installation description 264. !92(bXc)(dXe)
Secondary containment system plans 264.193(a)(b)(c)(d)
8.0
9.0
10.0
11.0
12.0
13.0
270.16(h)
270.16(i)
270.14(5X5)
270.14(b)<7)
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
270.14(b)(13) Closure and post-closure plans
270.16(j)
264.193(g)
264.194(b)
264.195
264.196
264.197
Procedures for tank systems that 264.198 and
store or treat ignitable or incom- 264.199
patible wastes
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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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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TABLE 3-2
EPA REGIONAL HAZARDOUS HASTE PROGRAM OFFICES
Region I:
Region II:
Region III:
Region IV:
Region V:
Region VI:
OFFICE OF THE DIRECTOR
State Waste Programs Branch
Waste Management Division
John F. Kennedy Federal Building
Boston, MA 02203
(617) 223-6883
OFFICE OF THE DIRECTOR
Solid Waste Branch
Air and Waste Management Division
26 Federal Plaza
New York, NY 10278
(212) 264-0505
OFFICE OF THE DIRECTOR
Waste Management Branch/RCRA Permit Section
Air and Waste Management Division
841 Chestnut Street
Philadelphia, PA 19107
(215) 597-0980
OFFICE OF THE DIRECTOR
Residuals Management Branch/Waste
Air and Waste Management Division
345 Cortland Street, NE
Atlanta, GA 30365
(404) 347-3067
OFFICE OF THE DIRECTOR
Waste Management Branch
Waste Management Division
Federal Building
230 Dearborn
Chicago, IL 60604
(312) 886-7579
OFFICE OF THE DIRECTOR
Hazardous Materials Branch
Air and Waste Management Division
First International Building
1201 Elm Street
Dallas, TX 75270
(214) 767-2730
Engineering Section
Continued on next page.
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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 Fremont 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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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 3*0 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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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 in 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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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 Ei3A lacks the in-house resources for expedi tiously isolating the
c:"idential from the non-confidential information.
If it is 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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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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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 an-d 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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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 (RCRA) permit application, is defined in Sec.
270.16(a) as a written assessment reviewed and certified by an independent,
qualified, registered, professional engineer which describes for eacn tank
system its structural integrity and suitability for handling hazardous waste.
To assess the structural integrity and acceptability of an existing tank
system for storing and treating hazardous waste, the owner or operator must
supply the Information set forth in Sec. 264.191:
(a) For each existing tank system that does not have secondary
containment meeting the requirements of Sec. 264.193, the owner
or operator must determine that the tank system is not leaking
or is unfit for use. Except as provided in paragraph (c) of
this section, the owner or operator must obtain and keep on
file at the facility a written assessment reviewed and
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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 wi11 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
(11) 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. 270.11(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.
254.192(a):
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(1) Design standard(s) 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;
(8) 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.;
(B) 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:
(1) Tank foundations will maintain the load of a full
tank;
-------
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
(ili) 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 remedie-d 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 B31.3, "Petroleum Refinery Piping," and ANSI
Standard 831.4 "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
-------
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 (cl)
of this section, were performed. These written statements must
also include the certification statement as required in Sec.
270.11 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.H. 1220 L Street, N.W.
Washington, 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) 532-2500 (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.
-------
Directive no.
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 011 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
-------
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, NJ 07007
(201) 882-1167
American Hater 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
-------
OSWER Policy Directive No. 9433.00-1
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.
Tank 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 outbreathing 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. Nonspecification 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
-------
ui receive ,10.
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.
8) 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 igni tabi 1 i ty, 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
-------
OSWER Policy Directive No. 9483.00-1
4-13
TABLE 4-2
IMPACT OF SELECTED HASTE 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
1iquid 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. 9433.00-1
4-14
TABLE 4-3
COMPATIBILITY OF MATERIALS OF CONSTRUCTION WITH VARIOUS CHEMICALS
Material
Compatible With
Incompatible Hi th
Minerals
Sulfuric add(1
Nitric acid
Phosphoric acid
Organic Acids
Acetic acid
Bases
Sodium hydroxide
Ammonium hydroxide
FRP<2>
Mild Steel
Rubber-lined
Hydrochloric acid(3) FRP
FRP(4)
FRP
Concrete—slow disinte-
gration at 101 phosphoric
acid
FRP
FRP
Mild steel(5)
Concrete (101)
Mild steel(5)
FRp(6)
Concrete
Concrete (101)
Mild steel
concrete, including
steel at 101-371
hydrochloric acid
Mild steel concrete.
with 21 and 401
Nitric acid
Mild steel
Mild steel
Mild steel(5)
Mild steel(5)
Sources: "Permit Writer's Guidance Manual for Hazardous Waste Tanks", U.S.
Environmental Protection Agency, EPA Contract 68-01-6515 (undated draft), pp.
8-5 through B-3.
"Effects of Substances on Concrete and Guide to Protective Treatments,'
Portland Cement Association (1981), pp. 7-11.
Footnotes at end of table.
Continued on next page.
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OSWER Policy Directive No. 9483.00-1
4-15
TABLE 4-3—Continued
Material
Compatible Kith
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—disintegration
of concrete with inade-
quate sulfate resistance.
Concrete products cured
in high-pressure steam
are highly resistant to
sulfates.
FRP . .
Concrete—slow
disintegration
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
Mi Id steel
FRP
Mild steel
Footnotes at end of table.
Continued on next page.
-------
OS*c.« ruucy Directive No. 9483.00-
4-16
TABLE 4-3—Continued
Material
Compatible Hith
Incompatible Hith
Aqueous Salts (Continued)
Alum
Solvents
Perchloroethylene
Carbon tetrachloride
Ethyl alcohol (11)
Methyl ethyl ketone
Acetone
Miscellaneous
Benzene
Hexane
Aniline
FRP
Concrete—di si ntegration
of concrete with Inadequate
sulfate resistance. Con-
crete products cured in
high-pressure steam are
highly resistant to sul-
fates.
FRP(8)
Concrete^)
FRp(10)
Concrete(9)
Mild steel
Concrete
FRP(12)
Concrete
FRP(14)
Concrete; however,
acetone may contain
acetic acid as impuri ty.
FRP(16)
Concrete
M1ld steel(17)
Stainless steel(18)
Mild steel
Mild steel
Mild steel
Stainless steel
Mi Id steel ('3)
Mild stee1(]5>
Mild steel
FRP
FRP
Mild steel
Footnotes at end of table.
Continued on next page.
-------
OSHER Policy Directive No. 9483.00-1
4-17
Table 4-3—Continued
Material
Compatible Nith
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
98%.
(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.
-------
uireuCive no.
4-18
Table 4-3™Cont1nued
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 501 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 669C.
(12) FRP is good from 10° to 35°C.
(13) M.S. is incompatible for concentrations below 1007..
(14) FRP is good for 101 concentration and 21" to 79.5'C.
(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 2T 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.
-------
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 1s 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
-------
e DO.
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. 264.191(b) 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
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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. 68-03-3069,
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.
-------
Policy Directive No. 9433.00-1
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uueecive fto.
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 temperatu"e
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
will be observed with an overall 1*F temperature change. Thus, in a
10,000-gallon benzene waste tank, it 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
Volumetric
Coefficient
of Expansion
Liquid (per Degree F)
Acetone
Amyl acetate
Benzol (benzene)
Carbon disulfide
Diesel fuel
Ethyl alcohol
Ethyl ether
Ethyl acetate
Fuel Oil #1
Fuel Oil #2
Fuel Oil #3
GASOHOL
.10 Ethyl * .90 Gasoline
.10 Methyl + .90 Gasoline
Gasol ine
Hexane
Jet fuel (FP 4)
Kerosene
Methyl alcohol
Stove oi 1
Toluol (toluene)
Water at 68"F
0.00085
0.00068
0.00071
0.00070
0.00045
0.00062
0.00098
0.00079
0.00049
0.00046
0.0004
0.000674
0.000684
0.0006 - 0.00068
0.00072
0.00056 '
0.00049
0.00072
0.00049
0.00063
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.
-------
4-28
what material the tank contains, including the respective volumetric
percentages of a mixture of materials. Waste layering in a tank
(because of immisclbility) 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) NATER 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 Psi 2 Psi 3 Psi 4 Psi 5 Psi
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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ObHcri r^O.iC> UlfdCdVe No. 94a J . 00- I
4-30
4) EVAPORATION
During the test period, volume changes caused by evaporation must be
compensated for in 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 25-26, 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 is 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).
-------
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 20158, "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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OSHER 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 rnanway 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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oiiCy ji i'fv.1 i ve No. 94o-.00-i
4-34
Tank Cleaning Hith 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 in 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. 9483.00-1
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 Writer'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.
-------
roncy u) rect;ve
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, identations, 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, glass, coatings, or
concrete. The inspection procedures and locations noted for solid steel tanks
are equally applicable to lined tanks.
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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
Jbe 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 1s 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.
-------
ujni_.\ rw.iLj^ Li I I sJL'lTi Vtf rtvj .
4-38
Tank Shell. 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
extremel-y 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, ongr'ound
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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OStNER 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 264.191(a) of the regulations requires that the assessment must
be conducted by January 12, 1988 for existing tank systems or within
-------
roiicy Directive No. y4oj.uu-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 264.191(d) 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;
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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
will 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.
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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 8 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(b) so that any tank
described in the application can be accurately Identified and classified.
This requirement helps to ensure that tanks are properly designed and
constructed in accordance with recognized guidelines and standards. The
Information on dimensions and capacity should be provided in addition to the
storage and treatment volumes of the tanks given in Part A, Section III
("Processes—Codes and Design Capacities") of the application. Each
Individual hazardous waste tank should be described independently in the Part
B application, with its dimensions and capacity clearly Indicated.
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^Giicy Uireceive No. y4dJ.ou-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 MateriaKs) 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 Hall 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-offs); 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'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
Plgur* 5-1
Tank Dimensions
CLEANOUT
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PIGURES ARE FOR ILLUSTRATIVE PURPOSES ONLY. THEY ARE NOT INTENDED FOR USE AS
CONSTRUCTION DRAWINGS.
-------
Figure 5-2
Tank Dimensions (Cent)
PLAN
3' FRP FLANGED NOZZLE
CONICALLY GUSSETTED
ZINC PLATED TIE
DOWN LUGSCTYP:
3' FRP FLANGED NOZZLE
3' FRP FLANGED NOZZLE
CONICALLY GUSSETTED
(SIPHON)
24' TOP HINGED MANWAY W/COVER
HOLD DOWN CLAMP
24' SIDE FLANGED MANWAY W/COVER
24' NEOPRENE GASKET
7/8tx41 LG. ST. STL. BOLTS, NUTS,
WASHERS
24' TOP HINGED MANWAY W/COVER
2'412"
k
D'O"
~ r~
1
^— ^
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i i
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^ 11' r" ^i
,0. p*
.325"
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.JT
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«- »,n 4
PROFILE
0.2501 SHELL THICKNESS f C R
REMAINDER 1 N C L U C I N G C 1 S H
^ i
j ,
5'0"
J_
T
5'0"
4^ . .
~ 7/8-X4' LG. BOLTS, NUTS,
e'o"
3' FRP FLANGED NOZZLE
Ix7 CONIC ALLY GUSSETTED (SIPHON]
T 8" TYP.
t
24' SIDE FLANGED MANWAY W/ COVER
24* NEOPRENE GASKET
FIGURES ARE FOR ILLUSTRATIVE PURPOSES ONLY. THEY ARE NOT INTEND
FOR USE AS CONSTRUCTION DRAWINGS.
o^r
-------
5-5
Figure 5-3
Tank Dimensions (Cont.)
MANWAY
4' STEEL ATMOSPHERIC VENT
\ 14 GAUGE
11' 2'
2'OF HIGH DENSITY RUBBER
INSULATION TO BE.APPLIED
TO TANK TOP IN FIELD
PLAN
-8 GAUGE STEEL
3' FLANGED .MOZZLE
TANK CLEANOUT
16'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 MAN W AY
'HOLD DOWN
TANK WALLS (8-14 GAUGE A31 STEEL]
TANK TO BE PAINTED WHITE
TO REFLECT HEAT
-------
Oiii^ ;.•; receive MO.
5-6
A) Aboveqround/Onground/Inground Tanks
Aboveground/onground/inground steel tanks can be either preconstructed
(fabricated by the manufacturer in a variety of standard sizes and
purchased ready-to-lnstall) 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. Wherever 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 they 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.
-------
OSHER Policy Directive Ho. 9433.00-1
5-8
TABLE 5-1
VERTICAL, ABOVEGROUND STEEL TANK MINIMUM WALL THICKNESSES(]>
THICKNESS (INCHES)
Capacity
(Gallons)
1 ,100 or less
Over 1 ,100
Carbon Steel
(2)
Shell
0.093
0.167
Bottom
0.093
0.240
Toe
0.093
0.123
Stainless Steel
(2)
Shell
0.086
0.115
Bottom
0.086
0.158
Top
0.086
0.086
Source: Underwriters Laboratory, Inc., UL 142, "Steel Aboveground Tanks
for Flammable and Combustible Liquids" (1985).
HORIZONTAL, ABOVEGROUNO STEEL TANK MINIMUM WALL THICKNESSES
THICKNESS (INCHES)
Capacity U.S.
Gal lens
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.
-------
OSHER Policy Directive No. 9483.00-1
5-9
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-------
Policy Directive No. 9433.00-1
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:
t
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
-------
OSWER 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
-------
roncy ui receive .10.
5-12
To provide Darning 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 In 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 iof variations on liquid delivery/vapor recovery
systems are available, and a description of the type of system
employed in each tjank 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 design|s for check valves: swing, lift, and ti Iting-disk.
Check valves are iavailable 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 off 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-dejlivery/vapor-recovery system;
i
o Type and location of any check valves, including size
and materials of construction; and
-------
Ui/ic..-. rGiiCji U I ret Live «u.
5-14
o Type of coupling connections, including size and
materials of construction.
B) 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
-------
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.
-------
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 pi lot-operated re!ief 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.
-------
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 Hhere 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?
-------
OSWER Polity 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
1ine-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);
-------
OSHER 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 I
U. Z
u; 2
s >-
< o
£ I
3 2
2 O
u. U
-------
5-22
Figure 5-6
Aboveground Tank System Connections
FIGURES ARE FOR ILLUSTRATIVE PURPOSES ONLY. THEY ARE NOT INTENDED FOR USE AS
CONSTRUCTION DRAWINGS.
-------
Uirective MG.
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:
(i) 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:
-------
5-24
(A) Corrosion-resistant materials of construction such as
special alloys, fiberglass reinforced plastic, etc.;
(B) 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
i
education and related practical experience, is qualified to provide
corrosion-control services for metal tanks and/or piping in contact with
soi 1.
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 fulfill1; the
requi rements.
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OSHER 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
-------
5-26
TABLE 5-3
COMMON FORMS OF LOCALIZED CORROSION
Type
Description
Bacteria) 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
(microscopic) of a metal or alloy.
boundaries
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 anc 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
Austenltic 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; NaCl , Including sea atmospheres am
waters; air; water vapor.
Water and steam; H2S04; caustics.
Chlorides, Including FeC12, FeC^, NaCl; se
environments; H2S04; fluorides; condensing steai
from chloride waters; acids.
HC1 ; caustics; nitrates; HNOs; HCN; molten zinc an
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 fe1
ppm oxygen.
Lead acetate solutions.
NaCl, Including sea environments; water and steam
caustics; N204i rural and coastal atmospheres
distilled water.
Fused caustic soda; hydrochloric and hydrofluorii
adds.
Bromides; caustics; H2S04-
Sea environments; mercury; molten cadmium; silver anc
AgCl; methanols with halides; red 'fuming HN03;
~ \; chlorinated or fluorinated hydrocarbons.
Source: Adapted from V.R. Pludek, Design and Corrosion-Control (New York, NY:
John Wiley and Sons, 1977).
-------
Figure 5-7
Corrosion Mechanisms
Pavement
Old Soil
Old Soil
Ww\
Bare Steel Tank
Anodic Region
(Corrosion)
Excavation'1^,
Boundary n
Pavement
Homogeneous Backfill
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.
-------
5-29
Figure 5-8
Corrosion Mechanisms (Cont.)
Pavement
Old Soil jm:£&f\ Cathode '" >pg$|lp
m&tfM VN° Corrosion) \&$j£ti
Anode
(Corrosion)
/Old Steel Tank
'New Steel Tank
-i-.--- •••••••. -•-• v;-v.v/.vyv-:./ {•>;;:-^Vv^.--:;>:.Vvx-.s;:-.v.vv;.>.V;;.v;:-/;^ i^'.-:-.^ Excavation
f^£vv;.;K:v^;':::;:^
* -'ft^^a>w^T7*«gr.TLT:gr,-^T^VXT »ga-a^x^gr^r^j^'VvTrgagjr"sr^^^jyvtT^sag^ira.T*r^^t rKf*tastAg^.r^s. ^^
so"
Pavement
Old Soil
Excavation
Boundary
Homogeneous Backfill
Cathodlc Regkxi
(No Corrosion)
(-)
I
V ~
'Anodic Region (Corrosion) (+)
FIGURES ARE POR ILLUSTRATIVE PURPOSES ONLY. THEY ARE NOT INTENDED FOR USE AS
CONSTRUCTION DRAWINGS.
-------
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) Sol 1 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 sulflde, 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 in 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
-------
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 1s 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 desfred
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 adds 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
-------
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 is 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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OSHtR Policy Directive No. 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 .
t
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 (NAC-!)
Standards RP-02-85 and RP-01-69, "Recommended Practice—Control 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 1s 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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OSWER Policy Directive No. 9483.00-1
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., 1s 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 1n 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.;
(B) 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
Once a corrosion expert has assessed the environmental conditions
surrounding a tank system, he/she will have a good idea of the extent of the
corrosion protection measures needed. The more corrosion protection measures
employed, generally, the greater the degree of protection (e.g.,
corrosion-resistant coating in combination with cathodic protection can
provide close to 100 percent corrosion control). The NACE and API references,
NACE RP-02-85, RP-01-69, and API 1632, provide additional Information on tank
system corrosion protection needs.
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OSHER 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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I I v C 11
5-40
TABLE 5-5
COATING/LINING VS. CHEMICALS
Coating/Lining Material
Generally Incompatible Hlth
Alkyds
Chlorinated rubbers
Coal tar epoxy
Epoxy (amine cured, polyamide
cured, or esters)
Polyesters
SIlicones
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
Vinyls (polyvinyl chloride-PVC) 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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OSHER 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
hoiiday 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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uirecuve NO. y46J.uo-i
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 cathodic 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 lining manufacturers can provide information on the
corrosion-resistant characteristics 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 cathodic-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. 264.192(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 electrical 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 HOT INTENDED FOR USE AS
CONSTRUCTION DRAWINGS.
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5-45
Figure 5-10
Factory Installed Sacrificial Anode
Pr«-«ngm««r»d
Stcrilicitl Anode
Attached by
Manufacturer
FIGURES ARE FOR ILLUSTRATIVE PURPOSES ONLY. THEY ARE NOT INTENDED FOR USE AS
CONSTRUCTION DRAWINGS.
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i Cjr
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. Hhen 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 cathodi c-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
cathodi c-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 0 C.
0 C Current
to Anod« 8»d
Anode Bed
NOTE: Piping not shown ttx clsnty
ol 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 arid 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.J92(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 owper or operator must include in the written assessment the
following information:
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 aamage;....
Guidance
In order to avoid premature structural failure, a tank system should be
designed and installed so that 1t 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 asphaltk concrete are suggested. (An alternative is
not less than 18 Inches of compacted backfill, plus at least 6 inches of
reinforced concrete or 8 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:
(i) 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
• iiii 'CL;... •. •.•:,••• ••.•.•••.•'••••••-'.' •. • v • •-.".•.:•••;•.•.• ,•>• \- .. ••••*,•:• •• •
•>:.•.".'. '.'Vv ••••*•*•' ': •'••***' ^'' *J •".•"•"••. *;'"'•*' •"•••'•.'.;'•;'• :?vv.V ':*."V'f".*•"""«*•'
Hold-down pad
8 »n. reinforced concrete Mln. 37' backfB
In place
Nonconductive
V>:::.v.v.v.y >.•...;;••••:•.•
•'"fe'V/^VVi.'jff Straps and collectors t::/:::;:::;;
Deadmen anchors
Figure 5-12
Anchoring Techniques
Mid-anchoring
FIGURES ARE FOR ILLUSTRATIVE PURPOSES ONLY. THEY ARE NOT INTENDED FOR USE AS
CONSTRUCTION DRAWINGS.
OSWER Policy Directive 9433.00-1
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r w< : I >.J U i i Cw i. I »C 11O .
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 oji 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)(1i) 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. 946J.00-I
5-53
seismic design for storage tanks and piping, including details on anchoring
specifications and calculations. This 1s 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)<5><111>:
Tank systems will withstand the effects of frost heave.
Guidance
Tank_s_ystem$ 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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OSW£R Policy Directive Ho. 94«j.00-i
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 documg-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
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?
Has 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?
t
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 in 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. 948.1.00-1
5-57
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
Ci tation
•
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/
Instal1 at ion.
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OSWER Policy Directive No. 946J.00-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 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
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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.
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OSHER 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
1s 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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cy Directive No. 948J.OO-I
6-6
A spreader bar to separate the hoisting chains or cables at tne
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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OSHER 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(5) 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.
-------
I j a » i j
6-3
D«pth of Foundation j
Flgur* 0-2
Excavation Design: Recommended Distance from
the Nearest Foundation
FIGURES ARE FOR ILLUSTRATIVE PURPOSES ONLY THEY ARE NOT INTENDED FOR US€ AS
CONSTRUCTION DRAWINGS.
-------
6-9
Figur* 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 Dlr«ctlv« 9483.00-1
-------
roiicy Directive
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-
ances 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 table 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
i»d-uniform1y 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--CONTINUEO
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 iuuilding 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. [ J
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
V'-IO' 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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OSWER Policy Directive Mo. 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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KOI icy uireceive no.
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
—.——•-——————— t
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 oae foot of backfill and four inches of
reinforced concrete, must be placed above a tank in a non-traffic area
(for backfill cover specifications in an area with traffic, see document
Section 4.1). Eighteen, or preferably, 24 inches of backfill are needed
between adjacent tanks and between tank sides and the edges of an
excavation. Pressure imposed on a tank should not exceed five pounds per
square inch (psi). If the depth of backfill cover Is greater than a
tank's diameter, the tank manufacturer should be consulted to determine if
reinforcement of the tank Is desirable. FRP tanks should not have more
than seven feet of overburden. Special cover and spacing requirements may
exist for very large tanks; see manufacturers' installation instructions.
Deep pits in unstable soil conditions may require extra support or shoring
to prevent cave-ins during installation. In addition, because backfill
provides as much as 90 percent of the tank support for an FRP tank,
manufacturers of such tanks provide special Instructions for tank
installation in unstable soil environments '(muck, bog, peat, swamp, or
landfill areas). Typical excavation considerations include soil
stability, and space for anchors and observation wells. Double-walled
underground tanks installed in unstable soil conditions may require a
filter fabric to separate backfill from adjacent soil to prevent backfill
migration. Filter fabrics are geotextiles designed to stop movement of
backfill materials while allowing water to pass through. If sand and pea
gravel are used together in an Individual excavation, they should be
separated with the filter fabric to preclude the migration of sand fines
into voids between the pea gravel particles. A reference on worker safety
precautions In areas with unstable soil is "Construction Industry
Standards and Interpretations" (1985), OSHA Publication 2079.
Backfill should be placed carefully along the bottom quadrant and end caps
of a tank to ensure that the tank Is securely and evenly supported. The
compacted backfill beneath a tank permits the forces present to be
dissipated uniformly over a large area. The backfill base should extend
one foot beyond the perimeter of a tank. No voids (air spaces) should
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OSHER Policy Directive No. 94,83.00-1
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.
-------
6-17
Figur* 6-5
Backfill
Secondary
Containment
Liner
WRONG
Bedding
FIGURES ARE FOR ILLUSTRATIVE PURPOSES ONLY. THEY ARE NOT INTENDED FOR USE AS
CONSTRUCTION DRAWINGS.
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Cy Directive Ho. 943J.UU-I
6-18
6.3 PRE-SERVICE TANK AND ANCILLARY EQUIPMENT TESTING
Citation
Tightness testing of a tank and Us 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 anticipated 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 pip'ing 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 Mo. 9483.00-1
6-21
thread lubricant
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OSHER Pohcy 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
careful l_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 B31.4, "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
-------
6-24
Piping w/Secondary
Containment \
Stop* to
Drain to
Explosion Proof
Motor and Pump
B«rm
Secondary Containment
Liner
Leak Detection
Device
Reinforced Concrete
Foundation
Sump
Undisturbed. SoO
Figure 6-6
Partially Buried Vertical
Hazardous Waste Tank
with Secondary Containment
OSWER Policy Directive 9483.00-1
FIGURES ARE FOR ILLUSTRATIVE PURPOSES ONLY. THEY ARE NOT INTENDED FOR USE AS
CONSTRUCTION DRAWINGS.
-------
6-25
Flgur* 0-7
Underground Tank and Piping System
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FIGURES ARE FOR ILLUSTRATIVE PURPOSES ONLY THEY ARE NOT INTENDED FOR USE AS
CONSTRUCTION DRAWINGS.
-------
6-26
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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
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
§270.11(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 1n 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.IHd) 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.. preinstallatlon 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 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 systetn(s) will be Installed in compliance with Sec. 264.192(b),
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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 promctly
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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OSWER 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 B of the permit application, as
specified in Sec. 270.16
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OSWER Policy Directive No. 9483.00-1
7-3
Gui dance
The Sec. 264.193U) 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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1c.r> rO I i v._/ w n «JC £ I vfc rtU.
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
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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
potentia]_ 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)(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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OSH£R Policy Directive No. 9483.00-1
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
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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.
Abcvsground 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. 9483.00-!
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
1n 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 deb'-is 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
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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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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.j u M BW I I ve flu.
7-10
The leak-monitoring systems are discussed below, and include the
following:
o Hire grids
o Observation welIs
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 change 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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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.
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ui receive NO.
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
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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
soils engineering, 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.
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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(0).
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
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OSHER 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 thfs 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.)
0) 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«pttt of Foundation '
• i
Flgur* 6-2
Excavation Design: Recommended Distance from
the Nearest Foundation
FIGURES ARE FOR ILLUSTRATIVE PURPOSES ONLY THEY ARE MOT INTENDED FOR USE AS
CONSTRUCTION DRAWINGS.
-------
6-9
Figure 6-3
Excavation
Unstable
Soil
/ TANK A
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
-------
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.
1. Tank Delivery
1.1
When the tank' is delivered, inspect the
tank on the carrier vehicle for weld
breaks, punctures,
coatings, cracks,
structural damage.
such as tie downs,
supports, etc.
scrapes of protective
corrosion or other
Check stress points,
anchor blocks, cradle
1.2 Observe off-loading of tank for conform-
aaces 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.
Observe final lifting and placement in
excavation. Look for same items as in 1.1
and 1.2 above.
Completed Initials Date
C ]
C ]
C ]
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 table 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
a*wj-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--
ooserve 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. [ J
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 Mo. 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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OSHER Policy Directive No. 9483.00-1
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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OSWER 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
(for backfill cover specifications in an area with traffic, see document
Section 4.1). Eighteen, or preferably, 24 inches of backfill are needed
between adjacent tanks and between tank sides and the edges of an
excavation. Pressure imposed on a tank should not exceed five pounds per
square inch (psi). If the depth of backfill cover is greater than a
tank's diameter, the tank manufacturer should be consulted to determine if
reinforcement of the tank is desirable. FRP tanks should not have more
than seven feet of overburden. Special cover and spacing requirements may
exist for very large tanks; see manufacturers' installation instructions.
Deep pits in unstable soil conditions may require extra support or shoring
to prevent cave-ins during installation. In addition, because backfill
provides as much as 90 percent of the tank support for an FRP tank,
manufacturers of such tanks provide special instructions for tank
•
installation in unstable soil' environments (muck, bog, peat, swamp, or
landfill areas). Typical excavation considerations include soil
stability, and space for anchors and observation wells. Double-walled
underground tanks installed in unstable soil conditions may require a
filter fabric to separate backfill from adjacent soil to prevent backfrll
migration. Filter fabrics are geotextiles designed to stop movement of
backfill materials while allowing water to pass through. If sand and pea
gravel are used together in an individual excavation, they should be
separated with the filter fabric to preclude the migration of sand fines
into voids between the pea gravel particles. A reference on worker safety
precautions In areas with unstable soil is "Construction Industry
Standards and Interpretations" (1985), OSHA Publication 2079.
Backfill should be placed carefully along the bottom quadrant and end caps
of a tank to ensure that the tank is securely and evenly supported. The
compacted backfill beneath a tank permits the forces present to be
dissipated uniformly over a large area. The backfill base should extend
one foot beyond the perimeter of a tank. No voids (air spaces) should
-------
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 s,upport 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
Figur* 6-5
Backfill
B«ddmg
L
Secondary
Containment
Liner
WRONG
Void Space
FIGURES ARE FOR ILLUSTRATIVE PURPOSES ONLY. THEY ARE NOT INTENDED FOR USE AS
CONSTRUCTION DRAWINGS.
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u:swc.A t'oiiL.y uirecdve Ao.
6-18
6.3 PRE-SERVICE TAN< 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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OSHER 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 (aboveground and underground, prior to installation) may be tested
hydrostatical ly at 150 percent (but not less than 50 psi) or pneumatically
at 110 percent of the maximum anticipated 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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OSWER 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
i nformation.
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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OSHER 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
careful l_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 expli ci tly.
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 909 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 Mo. 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
Piping w/Secondary
Containment \
Slope to
Drain to
Explosion Proof
Motor and Pump
Reinforced Concrete
Foundation
Berm
'- Secondary Containment
Liner
Leak Detection
Device
Sump
Undleturoed.Sofl
Figure 6-6
Partially Buried Vertical
Hazardous Waste Tank
wfth Secondary Containment
OSWER Policy Directive 9483.00-1
FIGURES ARE FOR ILLUSTRATIVE PURPOSES ONLY. THEY ARE NOT INTENDED FOR USE AS
CONSTRUCTION DRAWINGS.
-------
6-25
Figure 6-7
Underground Tank and Piping System
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FIGURES ARE FOR ILLUSTRATIVE PURPOSES ONLY. THEY ARE NOT INTENDED FOR USE AS
CONSTRUCTION DRAWINGS.
-------
6-26
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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(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
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
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OSHER Policy Directive No. 9483.00-1
6-29
6.7 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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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. 9483.00-1
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 B of the permit application, as
specified in Sec. 270.16(g)--"Deta11ed 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. 254.193(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(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. V2.1987):*
(1) 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, F021.F022, F023, FQ25, 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. 264.193U) 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 (See. 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
-------
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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OSH£R Poiicy 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
potentia]_ 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)(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. 254.191(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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Cintn r-o.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)(1) 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
hydrologic, 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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OSHER 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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UbHtK Policy D!receive No. 9483.00-i
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 wel1-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(0(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 monitoring- systems most widely used for
underground and inground tank system-s 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
equi pment.
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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UifeCClve no.
7-10
The leak-monitoring systems are discussed below, and include the
fol lowi ng:
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.
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 1n 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
Survei1 lance 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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7-13
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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 aUrm 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-Re sistivity 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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OSWtR Policy Directive No. 9483.00-:
7-16
TABLE 7-2
COMPARISON OF VARIOUS LEAK-SENSING TECHNIQUES
Sensor
Applications
Advantages/D isadvantages
Thermal-
Conducti vi ty
Sensors
Can monitor 1iquids in
soils
Primary advantage is early
detection, which makes 1t
possible for leaks and spills
to be corrected before large
volumes of material are dis-
charged.
Electrical-
Resistivity
Sensors
Can monitor 1 iquids
soi Is
in
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 al1 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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OSHER 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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i^y ui receive NO. y4tfj.uu-i
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 1s 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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OSWER 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 2"65 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 each 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
Stindpipe
or
Electronic
Liquid
Detection
Inner Tank
Wall
DOUBLE-WALLED STEEL TANK
Exterior Protection:
• Coal-tar epoxy with
•acrificlal anodes; or
• FRP Coa'mg
Interstitial Space
. NOTE' May not be present for electronic monitoring
DOUBLE-WALLED FRP TANK
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 Spaca
(Monitored for
Vacuum, Prassura,
Vapor or Liquid)
Shall Spacer
Innar Wall
Shall Spacar
Coating to Provide
Corrosion Protection
for External Wall
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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 surround 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 tr; 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
-------
7-28
Figure 7-9
Typical Earthen Dike Construction
1' MM..
l«Y*r to pr*T«nl
under dlk*.
IMPCTVIOUS CORE
bickfiiUd
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ic-iicy Directive No. 5"iu^.OO-
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
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 In 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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^iicy ui receive rtu. y4oj.00-l
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 1s most
economical when mass produced. Post-tentioned concrete is often used for
large liners with relatively simple layouts.
Section 264.193(e)(l)(iii) 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 1n 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 seal's are more susceptible 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 1n 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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OSHER Policy Directive ,No. 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
in 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 Uner 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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OSWER Policy Directive No. 9483.00-1
7-35
Selection of the most appropriate • 1iner for a given waste/
environment situation, specifically one that will provide the
longest service • 1 Ifetime, 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 thi s 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.
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 chemi st.
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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OSHEK Policy Directive No. 9483.00-1
7-36
•
0) Bentonites
Bentonites 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
destabi1ization 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 rol1 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:
(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) Constructed with chemical-resistant water stops in place at
al1 joints (if any);
(iv) 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
(vi)~~ 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 slao
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 ignltable 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
Figure 7-11
Waterproofing at Comer of Vault Base
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
7-41
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
compatibi1ity 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 Barrier 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
Total Nominal
Thickness Range
Typical Protective
Barrier Systems
Typical Uses
Mild
Under 40 mil
(1 mm)
Intermedi ate
125 to 375 mil
(3 to 9 mm)
Severe
20 to 250 mil
(1/2 to 6 mm)
Polyvinyl butyra!,
polyurethane, epoxy,
acrylic, chlorinated
rubber, styrene-
acrylic copolymer.
Asphalt, coal tar,
chlorinated rubber,
epoxy, polyurethane,
vinyl, neoprene, coa'
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,
procured neoprene
sheet, plasticized
PVC sheet.
o Protection against
deidng salts.
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
concrete in
with chemi-
havi ng
4, de-
pending on the chemi-
cal.
Protect concrete
from abrasion and
i ntermi ttent exposure
to dilute 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,
Dampproofing, 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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OSHER 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
shel 1; and
(iii) Provided with a built-in continuous leak detection system
Guidance
A double-walled tank 1s 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
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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 prooes
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), with 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
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OSHER 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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7-48
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OSHER 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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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. 264.193(0(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. Hhen 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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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 B 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 Will 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 Waste from
Ancillary Equipment, March 1986.
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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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o Is the accumulated waste and precipitation, if defined as hazardous
under 40 CFR 261, managed as a hazardous waste under RCRA ?
o Oo 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
Admini strator?
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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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 shell ;
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
dai ly visual inspection;
Welded flanges, welded joints, and welded connections, that are
visually inspected for leaks on a daily basis;
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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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8.0 VARIANCES FROM SECONDARY CONTAINMENT
Section 264.193(g)(l)(2) 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)(4)(A) 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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mechanism by which an owner or operator may identify and describe factors such
as waste attenuation, degradation, and migration rates that assure either no
migration from the zone of engineering control or no substantial risk from
hazardous constituents (hazardous constituents are defined in Appendix VIII of
40 CFR 261). An applicant for a technology- or a risk-based variance is
required to submit a report including the Information described below with
conclusions that provide the permit writer with a basis for evaluating the
adequacy of the variance request.
8.1 TECHNOLOGY-BASED VARIANCE
Citation
Sec. 264.193(g>. The owner or operator may obtain a variance from
the requirements of this section if the Regional Administrator finds,
as _a result of a demonstration by the owner or operator that
alteTnative design and operating practices, together with location
characteristics, will prevent the migration of any hazardous waste or
hazardous constituents into the ground water; or surface water at
least as effectively as secondary containment during the active life
of the tank system or that in the event of a release that does
migrate to ground water or surface water, no substantial present or
potential hazard will be posed to human health or the environment.
New underground tank systems may not, per a demonstration in
accordance with paragraph (g)(2) of this section, be exempted from
the secondary containment requirements of this section.
(1) In deciding whether to grant a variance based on a demonstration
of equivalent protection of ground water and surface water, the
Regional Administrator will consider:
(i) The nature and quantity of the wastes;
(11) The proposed alternate design and operation;
(ill) The hydrogeologic setting of the facility, including the
thickness of soils present between the tank system and
ground water, and
(1v) All other factors that would Influence the quality and
mobility of the hazardous constituents and the potential
for them to migrate to ground water or surface water
(3) 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 but has not migrated beyond the zone of engineering
control (as established in the variance), must:
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(4)
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 It 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)(ii) of this section,
comply with the requirement of §264.197(b).
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)
(ID-
Comply with the requirements of §264.196(a), (b), (c>,
and (d); and
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
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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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 wi-th 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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does reach ground water or sur-face-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 '^nances. 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(g)(3), the response to a release from a tank system
with a technology-based variance that has not migrated beyond the zone of
engineering control (as defined in the permit variance) must comply with
the measures of Sec. 264.196, (see Section 11.0 of this document) except
for paragraph (d) notifications and reports. All contaminated soil within
the zone of engineering control must be either removed or decontaminated
to prevent the migration of hazardous waste and hazardous constituents to
ground water or surface water and to enable the tank system's release-
detection mechanism to be at least as effective as that in place prior to
the release and upon which the variance was granted. When all soil
contamination problems are remedied, an owner or operator must repair the
leaking component and provide it with secondary containment that satisfies
the requirements of Sec. 264.193, before returning the tank system to use.
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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(b) 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 zore 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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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.
CB] The hydrogeological characteristics of the facility
and surrounding land,
[C] 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
_ ~ C£] 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,
[C] The current and future uses of ground water in the
area, and
CD] 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,
CB3 The patterns of rainfall in the region,
CC] The proximity of the tank system to surface waters,
CD] 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
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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).
Hhen 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 toxldty 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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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) of jt release can be identified. The type and amount of information
needed "for 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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The allowable hazardous constituent concentration lirnit(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 limit(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.
B) 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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o Estimation of adsorption potential (for given" constituents)
within the unsaturated zone.
Other information required for a risk-based variance demonstration
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 17 described.
The applicant shoul'd 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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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 Haste.
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 Hydroqeoloqy. 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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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 final hydrogeolog"y 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 pre.sent 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
biodegradation 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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wjni_A r w i i ujr u I I Si. i. i Vi->
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) 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) For existing tank systems, at least 24 months prior to
the date that secondary containment must be provided in
accordance with paragraph (a) of this section.
(11) 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).
(2) As part of the notification, the owner or operator must also
submit to the Regional Administrator a description of the steps
necessary to conduct the demonstration and a timetable for
•completing each of the steps. The demonstration must address
each of the factors listed In paragraph (g)(l) or paragraph
(g)(2) of this section;
(3) The demonstration for a variance must be completed within 180
days after notifying the Regional Administrator of an intent to
conduct the demonstration; and
(4) 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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OSHER 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
characteristics;
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;
-------
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?
o 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?
o "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?
o 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
autoaatic 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
-------
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
spil1/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
perrni t 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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OSHER 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,
generally 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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ui receive MO.
9-4
TA3LE 9-1
CHAR ACTS IS TICS OF FNiWATrC VTO EL-CT70SIC CONTROLS
Feature
Transmission distance
Standard transaissloo signal
CompatibllitT betveen instruments
supplied by different manufacturers
Concrol valve coapatibllitv
Co>spatabilitv with digital cotputer
or daca logger
Reliability
Reaction to very low (freezing)
temperatures
Reaction to electrical Interference
(pickup) _
Operation in hazardous locations
(explosive atmosphere)
Reaction to sudden failure of energy
supply
Pneuaiatic
lad cost of installation
System eomoatibility
Ease and cost of maintenance
Dynamic response
Operation in corrosive ataosphere
Perforaance of overall control
systea*
Politics (the unaentioned factor)
Limited to fev hundred feet
3-15 psi practically universal
So difficulty
Controller output operates control
valve operator
Pneuaacic-to-electric converters
required for all Inputs
Superior If energized with clean dry
air
Inferior unless air supplv is
complete IT dry
Mo reaction possible
Complete IT safe
Superior - capacity of svstea pro-
vides safety xargia - backup
inexpensive
Inferior
Fair - requires considerable auxiliary
equipment
Lower If installation costs are not
considered
Slower but adequate for aost iltuations
Suoerior - air supply txcoaes a purge
for aost In a truants
Excellent, If transaisslon distances
are reaaooable
Cenerallv regarded as acceptable but
ioc the latest approach
Electronic
Practically unllaited
Varies with aanuficture:
Monstandard sijraals reouire soecial :
siderstion and aa» not be
Pneumatic operators with elecrro-
pneunatic converters or electronvdrau
or electric aotor ope-racor reouirsd
Easily arringed wish ainiaus jd>J.e-i
equipaent
Excellent under usual eovironae-ical
conditions
Superior
Ho reaction with the sys tea if
properly Installed
Intrinsically safe equimsen:
available mat be reaoved for
aost aaintenance
Inferior - electrical failure
disrupt plant - backuo
Superior
C-ood - conditioning ani auxilar
equinaent aore conoati': le zs
sys teas ipproacn
Higher - becomes coooecitive
Including Installation is co
Excellent - frequently vslve
Halting factor
Inferior - unless special
Is gives and suitable steps tanen
Excellent - ao restriction cm trans-
mission distance
Often regarded as Che lacest and 103 c
aodcrn approach
Source: Anderson, N. A. , Instruoentjclon for Process Measurement «id Control, Second Edition, CMl:on BOCK "
5601 Chescaut Street, Philadelphia, PA 19139, 1972.
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OSWER 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
-------
u i ; c w >. i » C
9-6
TABLE 9-2
LEVEL-DETECTION DEVICES FOR UNDERGROUND STORAGE TANKS
Type
Monitor
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-conductivity
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.
-------
Figure 9-1
Tape Float Gauge
for
Underground Storage Tank
Gu!d«_
Wires
Float
»
Sh*av««
Gag* Board
c
c
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a
^
o
c
a
tt
LU
»
CO
o
FIGURES ARE FOR ILLUSTRATIVE PURPOSES ONLY. THEY ARE NOT INTENDED FOR USE AS
CONSTRUCTION DRAWINGS.
-------
OSWER Policy Directly* 9483.00-1
9-8
Figure 9-2
Float Vent Valves
FIGURES ARE FOR ILLUSTRATIVE PURPOSES ONLY. THEY ARE NOT INTENDED FOR USE AS
CONSTRUCTION DRAWINGS.
-------
OSHER Policy Directive No. 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
-------
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.) When 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 in 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 usec 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 in 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
-------
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. .
t
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.
B) 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
-------
9-12
OSWER Policy Dlr«ctlv« ^9483.00-1
Flgur* 9-3
Optical Liquid Level Sensing System for Bulk Storage System
Control
Monitor
Conduit Run Typ*e«l
FIGURES ARE FOR ILLUSTRATIVE PURPOSES ONLY, THEY ARE HOT INTENDED FOR USE AS
CONSTRUCTION DRAWINGS.
-------
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 in 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. With 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 will 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 wnen
-------
receive d^. y4oj.uu-
9-14
TABLE 9-3
TRANSFER SPILL-PREVENTION SYSTEMS
System
Function
Spill Control
Applications
Ordinary quick-
disconnect coupl-
ing
Product None
transfer
Tank vehicles and
storage tanks
Quick-disconnect
coupling equl-p-
ped with_ball-
valve "~
Product Built-in valve re-
transfer duces spills from
disconnect hoses
Tank vehicles and
storage tanks
Dry-disconnect
coupling
Product No spills from
transfer disconnected hoses
Tank vehicles and
storage tanks
Emergency shutoff Flow
valves control
A fusible metal
1 ink melts and
closes the valve
in case of fire
or Impact
For use any place
where in the event
of fire it is
important to stop
flow
-------
9-15
Gat* Valve
Composed of a body containing
a gat* that Interrupts flow
Globe Valve
Valve disk moves axially to
rest against valve seat, blocking
flow
Plug Cock
Composed of a tapered plug wtth
center hold that ffis snugly into
correspondingly shaped valve seat
Ball Valve
Similar to plug cocks wtth the
exception that the plug is
cylindrical
Figure 9-4
Types of Valves
c
c
<•
a
«!
0
3
C.
"c
a
a
u.
3
FIGURES ARE FOR ILLUSTRATIVE PURPOSES ONLY. THEY ARE NOT INTENDED FOR USE AS
CONSTRUCTION DRAWINGS.
-------
9-16
Angle Valve
Similar to globe valve
i
o
o
«
03
*f
0>
Diaphragm Valve
Diaphragm functions as both
closure mechanism and seal
tr
ui
£
in
O
Butterfly Valve
A 9O-degree turn of valve stem changes
valve from completely closed to
completely open
Figure 9-5
Types of Valves (Cont)
FIGURES ARE FOR ILLUSTRATIVE PURPOSES ONLY THEY ARE NOT INTENDED FOR USE AS
CONSTRUCTION DRAWINGS.
-------
9-17
Lift Check Valve, Gk>b«
Lift Check Valve, 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.
-------
9-18
o
5
ea
U'
en
G
U
O
Iv
K
Z
O
Z
6
o
e
a.
O
a
a
JC
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3
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^~
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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 soaklng-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
-------
9-20
1. Ordinary Quick Disconnect
2. Quick Disconnect Plus Bail Valve
f
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
9-21
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 transferring
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.
(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. (38001) 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 is 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. 9433.00-1
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 ABOVEGROUNO/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.)
-------
9-23
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9-24"
4) Installation of redundant valves and instrumentation.
A) Elements of an Overfill Prevention System for Aboveground/Inqround/
Onqround 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
discussed 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
-------
OSHER Policy Directive No. 9483.00-1
9-25
TABLE 9-4
LEVEL-DETECTION DEVICES FOR OVERFILL PROTECTION SYSTEMS
FOR ABOVEGROUND/INGROUND/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
Magnetical ly-coupled
Yes
Yes
Yes
Gauge
Gauge
Gauge
Interfaces with electronic or
pneumatic controls
Interfaces with electronic or
pneumatic controls
Interfaces with electronic or
Displacer Devices
Flexure-tube displacer
Magnetically coupled
displacers
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 1n large atmospheric storage tanks. Drawbacks to
using these devices Include: (1) potential for getting out
of al1gnment;(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
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Lever and Shaft Float Gauges
FIGURES ARE FOR ILLUSTRATIVE PURPOSES ONLY. THEY ARE NOT INTENDED FOR USE AS
CONSTRUCTION DRAWINGS.
-------
9-29
FIGURES ARE FOR ILLUSTRATIVE PURPOSES ONLY. THEY ARE NOT INTENDED FOR USE AS
CONSTRUCTION DRAWINGS.
-------
9-30
systems can be used 1n cage mountings or side
mountings in vented (atmospheric), pressurized, or
evacuated (vacuum) tanks. Three commonly used
dlsplacer systems—-flexure-tube, magnetically-coupled
and torque-tube—are briefly described below.
Flexure-Tube Displacers. 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.)
Magnetically-Coupled Oisplacers 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 Displacers are among the most widely used
level-measuring devices. This type of device Is
suspended on a displacer rod attached to a torque
tube. (See Figure 9-15.)
Hydrostatic-Head or Pressure Devices. As with displacer
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
-------
9-31
Figure 9-13
Flexure-Tube Displacer
Mounthg Range
Umrt Stop
Bracket
Rattened
Section
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CONSTRUCTION DRAWINGS,
-------
9-32
Figure 9-14
Magnetically Coupled Displacers
Drive Magnet
_ Non-magnetic Tube
Magnet Follower
Dicplacer Cage
Oiepiacer
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-------
9-33
Figure 9-15
Torque-Tube Displacer
Dleplacer Rod
Torque Tube
Rotary Shan
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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iiA roncy u i ret. Live f+o.
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
1n 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
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Supply
Constant Row
Regulator
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Figure 9-16
Bubble Tube System
FIGURES ARE FOR ILLUSTRATIVE PURPOSES ONLY. THEY ARE NOT INTENDED FOR USE AS
CONSTRUCTION DRAWINGS.
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no.
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 is recommended
that both audible and visual alarms be used. In this case, one
Indicator light per tank 1s 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 No. 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, I 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 Is 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
-------
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,
pressure or temperature
• Can be operated electrically or pneumatically
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OSHER 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.
B) Transfer Spill Prevention Systems for Aboveground/
"Inground/Onground 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 valvlng 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. 9433.00-1
9-40
C) Proper Operating Practices During Loading and Unloading.
1) 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.KC) of this
manual for details on proper liquid transfer practices, which are
equally applicable to both underground and aboveground/inground
tanks. (Also refer to HFPA 385 for further information on loading
and unloading practices.)
2) RECOMMENDED AREAS FOR TRANSFER OPERATIONS
Transfer operations should be conducted only in specif '.cally
designated transfer areas that are equipped 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 catchbaslns
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(5X3) 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 TOO 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 1t 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.
Q - 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 min for alarm system only In operation area
t - 15 min 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.)
Information 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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Policy Directive to. 9463.ou-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 8 permit application. It also
can be helpful in planning, preparing, and verifying the adequacy of a
spi11/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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OSHtK Policy Uirective No. 9483.00-1
9-43
B) Do you have the proper elements of a Transfer Spil]-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 Aboveqround/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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U I I w W L i 1' •<£
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 No. 94dJ.OO-l
10-1
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
non-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(b) stipulates that the
leak test that is employed must be capable of taking Into 'account the effects
of temperature variations, tank end deflection, vapor pockets, and high water
table effects.1] For other than non-enterable tanks, a schedule and procedure
must be developed and approved by the EPA Regional Administrator for assessing
the overall condition of the tank system. For ancillary equipment, a leak
test or other assessment must be performed annually.
General
Informati-en on inspection schedules must be included in Part B of the
permit application, as specified 1n:
Sec. 270.14(b)(5) A copy of the general i-nspection schedule required
by Sec. 264.15(b); Include where applicable as part of the inspection
schedule, specific requirements in Sec. 264.195 for tanks.
For the purposes of this technical resource document, only specific
inspection requirements for hazardous waste tank systems will be addressed.
See the "Permit Applicant's Guidance Manual for the General Facility Standards
of 40 CFR 264," Section 5.5, for information on general inspection
requirements.
The following sub-sections address the inspection requirements of the
regulations and give details on the methods and frequency of equipment
Inspections. In general, most of this chapter addresses metal tank
conditions. Fiberglass-reinforced plastic (FRP) tanks often fail by different
mechanisms of deterioration than metal tanks. Sub-section 10.6 Includes
specific FRP tank inspection information, and sub-section 10.7 discusses
concrete tanks.
Any hazardous waste facility that uses tanks to treat or store hazardous
waste must, in addition to the general inspection requirements of Sec. 264.15,
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OSHER Policy Directive No. 9483.00-1
10-3
comply with the specific inspection requirements of Sees. 264.195 and
264.193(1) (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 B 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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OSHER Poiicy Directive No. 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. 264.191U)
or
- other method as approved or
required by the EPA Regional
Admini strator
Annually
264.193(1X2)
264.193(1X3)
264.193(1X4)
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 and 1 lary 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
Administrator
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 Requirement
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
Dai ly
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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A rw I i S.J U , I tfy. \. l 1 £ ilu . 3-rC.j . U*-<-
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 da'ly 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 ABOVEGROUND 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 Policy 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
Daily 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 wifi usually allow detection of potential defects, which then will
require further detailed examination. Visual inspections ar£ 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 be 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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* i i * w . J ' r o .
10-8
A) Valves, Pipes. Fittings, and Hoses.
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 e1 bows
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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roncy Directive NO. y4oj.uo-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. Hhen 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 the 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.
B) Pum^s 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
followi ng:
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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rui ILJ LMreceive fio.
0
0
10-10
missing safety equipment such as a pump-coupling guard
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) Heat Exchangers.
Deterioration may be expected on all surfaces of exchangers and condensers
thafcontact chemicals, water (both salt and fresh), and steam. The form
of attack may be electrochemical, chemical, mechanical, or a combination
of the three typs-. 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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ruiiLjr u i i ev. L i »e no . 3 HO J . uv—
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 dally inspection is intended primarily to detect releases or
the potential for imminent releases and should include the following items:
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OSMER 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 wall 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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OSHEK Policy 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 containmnet 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) destabi1ization 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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OSWEk Policy Directive No. 9483.00-1
10-15
10.4 INSPECTION OF CATHODIC-PROTECTION SYSTEMS
Citation
Sec. 264.195(c) The owner or operator must inspect cathodic
protection systems, if present, according to, at a minimum, the
following schedule to ensure that they are functioning properly:
(1) The proper operation of the cathodic protection system must be
confirmed within six months after initial installation and
annually thereafter; and
(2) All sources of impressed current must be inspected and/or
tested, as appropriate, at least bimonthly (i.e., every other
month).
Guidance
Storage systems equipped with cathodic-protection systems require periodic
inspection if they are to ensure long-term protection that they were designed
to provide. .Conditions that affect protection are subject to change with
time, and corresponding modifications/adjustments may be required in the
cathodic-protection system. For instance, changes in soil resistivity,
moisture content, seasonal changes etc ... all impact the effectiveness of
cathodic protection output. An impressed current cathodic protection system
is designed to operate at a set voltage and amperage output based on observed
soil condition at time of installation. If soil conditions change
substantially, cathodic protection output should be altered as well to provide
adequate protection. (Short term changes In- soil are not significant, but,
any long term, substantial change should be conpensated for in
voltage/amperage output.) Conditions may exist where operating experience has
Indicated that testing and inspections should be conducted more frequently
than required herein. [The practices described in the National Association of
Corrosion Engineers' (NACE) standard, "Recommendation Practice
(RP-02-85)--Control of External Corrosion on Metallic Buried, Partially
Burled, or Submerged Liquid Storage System," and the American Petroleum
Institute's (API) Publication 1632, "Cathodic Protection of Underground
Petroleum Storage Tanks and Piping Systems," may be used, where applicable, as
guidelines in maintaining and inspecting cathodic protection systems.]
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10-16
A) Cathodic-Protectlon Systems.
Section 264.195(c)(l) 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 (.soil) 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 test: 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.
-------
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. 264.19U) 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 (i)(l) or (ii) 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 1n accordance with
paragraphs (1)(1) through (1X3) 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 (1X3) of this section, the owner or operator must comply
with the requirements of Sec. 264.196.
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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(1) 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 fail 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.
254.195 ("Ins-pections"). 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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K roiicy 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 thfi 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 bisulphate, sulfuric acid, and
sodium hydroxide; (most prevalent condition);
o Concrete may be permeable to some liquids.
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U;>«LK roiicy ui receive no.
10-22
The American Concrete Institute's (ACT) 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 magnet 1c_ 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 thermowells. The radiographic technique uses
either X-rays or gamma radiation. The X-ray Is produced In a tube within an
X-ray machine; the gamma ray is produced from a radioactive material contained
In 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.
Acoultic emissions testing employs piezoelectric transducers to monitor
the acoustic emissions given off by a . material during corrosion or
disbonding. Essentially, this technique involves "listening" to detect the
pressure of corrosion or other stressful situations 1n 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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OSHER Policy Directive No. 9483.00-1
10-25
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, it 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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._/ u i i €v. i i ve
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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OSHER 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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OSHER Policy Directive No. 9483.00-1
11-1
.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 Is 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 procedure's 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 is 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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vjn- . j i ! -jr u i .',.•* c i"-. S-»Gw . vU- i
n-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
(d) Notifications, reports
(e) Provision of secondary containment, repair, or closure.
(f) Certification of major repairs.
Guidance
Section 5.7 of :he "Permit Applicant's Guidance Manual for the General
Facility Standards" contains procedural requirements for implementing remedial
actions in the event of spills, leaks, or other unintended releases of waste
from a tank storage system. Tank system owners or operators must initiate
prompt, effective action to contain, recover, mitigate, and remedy any release
that poses a threat to human health or the environment.
The contingency plan required under Subpart D of Part 264 describes
procedures for responding to spills or leaks. It must include the schedule
and procedures for removal of leaked or spilled waste; removal of waste from
secondary containment systems, where applicable; and measures for minimizing
further releases.
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OSWER Policy Directive No. 9483.00-1
11-3
The intent of Sec. 264.196 ts 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, sr to provide secondary containment for the tank system,
repair the tank system, replace the tank system, or close the tank
system according to Sec. 264.197 (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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11-4
11.1 RESPONSE ACTIONS FOR LEAKS OR SPILLS
11.1.1 Haste 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 ironed lately 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
(1) 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 2_4 hours after detection of the release, or at the earliest possible
time if the owner or operator demonstrates to the permitting authority that 24
hours is too 1ittle 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
1s 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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11-6
bottoms" must be properly disposed of in accordance with applicable RCRA
regulations.
Logistics problems in some situations could prevent waste removal within
24 hours. In these cases, however, waste removal must commence within 24
hours; and be completed as soon as possible thereafter. In order to protect
human health and/or prevent further releases, it may require more than 24
hours to remove hazardous waste from the portion of a tank, system 1n which a
release Is occurring or is anticipated. Additionally, if compatible
alternative storage is not readily available, the owner or operator might
require more than 24 hours to complete waste removal activities.
In a similar manner, all waste released to a secondary containment system
must be removed within 24 hours or in as short a time as possible, so tank
system repairs can begin in a timely manner. All waste in a secondary
containment system must be removed to enable the leak-detection monitoring
system to function effectively.
11.1.3 Visible Release Containment.
Citation
Sec. 264.196 (c) Containment of visible releases to the environment.
The owner/operator must immediately conduct a visual inspection of
the release and, based upon that inspection:
(1) Prevent further migration of the leak or spill to soils or
surface water; and
(2) Remove, and properly dispose of, any visible contamination of
the soil or surface water.
Guidance
Section 264.196(c) requires the tank system owner or operator to conduct
an immediate visual inspection of a release and to prevent further migration
of the release to soil or surface water. Visible releases, primarily from
onground/inground aboveground tank systems without secondary containment,
require immediate attention to minimize their potential health and
environmental impacts. The response measures required by Sec. 264.196(c)
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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 Subparts C and D, all TSD treatment, storage
and disposal facilities must have emergency prevention and response equipment
on-s1te 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 11'ned
temporary storage areas. Any pools of liquid wastes in the soil should be
removed promptly using pumps.
For visib'e 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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OSHER 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 Naste 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. 264.196(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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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(e),
close the tank 1n accordance with Sec. 264.197, repair or replace the tank and
Install secondary containment, or, In special cases, only repair the damage.
Sec. 264.15(c) requires that any tank system equipment or structure showing
deterioration or malfunction during an Inspection be remedied, as per the
specific requirements of Sec. 264.196(e).
Removing a damaged tank is often the best solution, depending on specific
environmental conditions, tank age, and the nature of the tank system
failure. For example, It may be difficult to determine the location of a leak
in a non-entarable underground tank; in such cases, the tank may not be
adequately repaired and H should be removed instead. When existing tank
systems are relatively new,, however, there Is no Immediate need to replace
them. Repairing tank systems in-place may be reliable and is less costly than
replacement. Nevertheless, if a repair will be made in an underground or
inaccessible location, secondary containment for the repaired component must
be provided, as per Sec. 264.196(e)(4) . Closure of a tank system applies most
often to sites where the tank storage or treatment activity is to be
discontinued or moved to another location on the property.
If a tank system is to remain In use, Sec. 264.196(e) requires specific
remedial actions by the owner or operator. These actions are listed In Ta&le
11-1. The release scenarios addressed in Table 11-1 are described below.
Note that replacement tank system components are considered new
components, which means they must comply with all the design, installation,
containment, and detection of release requirements of Sees. 264.192 and
264.193. Also, all replaced tank system components must be decontaminated or
properly disposed of in RCRA-permi tted hazardous waste handling facilities.
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11-12
TABLE 11-1
SECTION 264.196 REQUIRED RESPONSES TO TANK SYSTEM RELEAS E S *
TYPE OF RELEASE
REQUIRED ACTIONS
CITATION
Spill 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, 1f 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.
264.196(e)<2)
264.196
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Spi 11s. 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 (e.g., repair of an automatic fill device) prior to
the tank system being placed in use again.
Leaks Into Secondary Containment. All leaks contained by a secure
secondary containment system must be cleaned up prior to placing a tank system
back In service. All tank system repairs must also be completed prior to tank
system usage.
Aboveqround Leaks with No Secondary Containment. A leaking or
unfit-for-use component may be repaired or replaced without installing
secondary containment if the component is to be visually inspected on a daily
basis (I.e., the component is aboveground and accessible). Ancillary
equipment Items where this situation might exist include aboveground flanges,
pipe fittings, pumps, and valves. When the repaired tank system is again
placed in use, visual inspection of the repaired or replaced component(s) must
become a part of the Sec. 264.195(b) daily 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 unf1t-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. 264,196(e) apply for this type of
release scenario, in addition to the certification requirement of Sec.
264.196(f). This requirement is described further in document Section 11.1.5.
Repair Considerations. Guidelines to Identify tanks that can be repaired
by applying or installing an interior lining are contained in API Publication
1631, "Recommended Practice for the Interior Lining of Existing Steel
Underground Storage Tanks." Tanks that are considered reparable by API have:
1. No open seams or splits longer than three inches;
2. No perforation larger than 1 1/2 inches in diameter, except under a
gauging opening where the perforation may be no longer than 2 1/2
inches in diameter;
3. Less than five perforations (none larger than 1/2 inch in diameter)
in any one square-foot area; and
4. Less than 20 perforations (none larger than 1/2 Inch 1n diameter) in
a 500 square-foot area.
The interior lining procedure involves entering a tank, to apply a
polyester resin or epoxy material on the Internal surface, leaving a
non-porous, non-corrosive coating. The technique Is highly specialized and
requires many safety precautions; only contractors trained and experienced in
the procedure should be used. Many localities require prior approval of the
application method and proof of contractor competence before authorizing use.
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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 failur? 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). Hhenever feasible, al 1 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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,J
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,
1f a fiberglass tank Is not properly supported by shoring or some form of
retaining surface, any future excavations near the tank could cause a
"roll Ing" 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, qualified,registered, . professional
engineer in, accordance with Sec. 270.ll(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
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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 is 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) Host 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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KOI icy Directive Ho. 94oJ.uG-i
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(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 must
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 B permit application,
and must be performed in a timely manner upon detection of an actual or
Imminent release:
o Has 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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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.)
Notification/reports
Is It most appropriate to repair, replace, or close the tank, system,
based on the extent of damage and the type of releases.
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?
Has -a certification of adequacy of major repairs been received from
an independent, qualified, regi-stered professional engineer:1
In addition, see Appendix A, "Completeness Checklist," to verify compliance
with the requirements of this section.
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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.U(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
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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 Is 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 8
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
(§264.14S)
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 Landfi11
(§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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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_c1osure 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 Esttmate (§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 1t 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
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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 tiie 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 waste. 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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y u i receive fto.
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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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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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 1s 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
r
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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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.
Disconnect and cap extraction (suction) lines.
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.
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.
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.
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 De published Fall of '87.
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12-10
D) 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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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. inground 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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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-dos-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 [§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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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-slte over the active life of the facility; (264.112(b)(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<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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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 clos-ed. Closure procedures may be based on either temporary or
permanent withdrawal from service, each requiring specific steps applicable to
the type of closure.
Within 60 days a~ter 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 B)
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 landfills (§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 tne
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 closed landfill;
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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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12-19
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 vnto
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 addressed 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 closure/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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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 tabular 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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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 plan 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(b) if contaminated soil,
system components, equipment, residues and structures cannot be
successfully removed under the closure care activities?
In addition, see Appendix A, "Completeness Checklist," to verify compliance
with the requirements of this section.
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13-1
13.0 PROCEDURES FOR TANK SYSTEMS THAT STORE OR TREAT
IGNITABLE, REACTIVE, OR INCOMPATIBLE WASTES
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 include fire, gas and/or heat generation, explosion, etc.
13.1 IGNITABLE OR REACTIVE HASTES, 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 1n 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 1s 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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OSKLK Poncy Directive No. 948J.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 ignitabi 1 ity;
§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, N£) that can cause
pressurlzation and subsequent rupture of a closed tank.
4. Toxic gas generation (e.g., ^S, HCN).
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13-3
FIGURE 13-1
40 CFR 261.21
CHARACTERISTIC OF IGNITABILITY
(a) A solid waste exhibits the charac-
teristic of tgnitablllty 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 80'C U40'F). 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 { 260.11). or a Seta.flash
Closed Cup Tester, using the test
method specified in ASTM Standard
D-3278-78 (incorporated by reference,
see f 280.11), or as determined by an
equivalent test method approved by
the Administrator under procedures
set forth in 55 260.20 and 260.21.
(2) It la 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 if 260.20 and 260.21.
(4) It is an oxidlzer as defined In 49
CFR 173.151.
(b) A solid waste that exhibits the
characteristic of ignitabillty, but is not-
listed as a hazardous waste In Subpart
D, has the EPA Hazardous Waste
Number of D001.
(45 PR 33119. May 19. 1980, u amended 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.
C8) It is a forbidden explosive as de-
fined in 49 CFR 173.51. or a Class A
"xplosive as defined (n 49 CFR 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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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, (national heat.
sparlcs (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)
CM FR 2848. Jin. 12. 1981. (4 amended it 50
PR 4514. J&n. 31, 19851
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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. Solubi1ization 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 or 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 if and only 1f 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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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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13-7
A tank system may be used temporarily to hold ignitable or reactive waste
in 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 WASTES
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 ignitable or reactive waste, the owner or operator of a
facility must comply with protective distance 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 hrave
to be compared to the 40 CFR 261.21 and 261.23 (Figure 13-1) definitions of
ignitables and reactlves. For example, a liquid waste with a flash point of
95*F :35'C) 1s 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 boll-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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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 terra liquid shall mean both flammable 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 200CF (93°C) shall be determined in
accordance with ASTM 0-56-82, Standard Method of Test for Flash Point by the
Tag dosed 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 200eF (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 (110'C), 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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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.
Boil-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 100aF
(37.8°C).
Combustible Liquids shall be subdivided as follows:
Class II liquids shall include those having flash points at or above
100°F (37.88C) and below 130'F (60°C).
Class IIIA liquids shall include those having flash points at or
above 130'F (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 (22.8eC)
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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13-11
TABLE 13-2 Continued
Class 1C shall include those having flash points at or above 73°F
(22.8°C) and below 100°F (37.8°C).
Unstable (Reactive) Liquid. A liquid which in its pure state or as
commercially produced or transported will vigorously polymerize, decompose,
condense, or will become self-reactive under conditions of shock, pressure, or
temperature.
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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
Building on the Same
Property and Shall Not Be
Less Than 5 Feet
Floating Protection 1/2 times diameter of
Roof1 for Exposure2 tank
None
Diameter of tank but
need not exceed 175 ft.
1/2 times diameter of
tank
1/2 times diameter of
tank
Vertical Approved foam 1/2 times diameter of
with Weak or inerting tank
Roof to system4 on
Shell Se_am3 -tanks not
exceeding
150 ft. in
di
Diameter of tank
2 times diameter of
tank but need not
exceed 350 ft.
1/2 times diameter of
tank
Protection
for
None
1/2 times diameter of
tank
1II times diameter of
tank
Horizontal
and Vertical
with Emer-
gency Relief
Venting to
Limit Pres-
sures to
2.5 psig
1/2 times Table 13-7
Approved
i nerting
system4 on
the tank or
approved
foam system
on vertical
tanks
Protection Table 13-7
for Exposures2
1/2 times Table 13-7
None
2 times Table 13-7
Table 13-7
Table 13-7
Footnotes and source on following page.
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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 2-1, "(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 Way
Minimum Distance in Feet
from Nearest Side of Any
Public Way or from
Nearest Important
BuiIding on the Same
Property
ANY TYPE
Protection
for
Exposures1
None
1-1/2 times Table 13-7
but shall not be less
than 25 feet
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 shall 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
brigldes 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 Di stance 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 Exposure^ tank
None
Approved Foam
Or Inerting
'System^
Diameter of tank
Diameter of tank
Protection 1/2 times diameter of
for Exposure^ 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 Nay
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
followi ng:
approved water
spray; approv-
ed inerting;!
approved insu-
lation and
refrigeration;
and approved
barricade
Protection for
Exposures2
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 1934."
SI Units: 1 ft. = 0.30 m.
Continued on next page.
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OSHER 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 Publ 1c 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;^
approved insu-
lation and
refrigeration;
and approved
barricade
•Protection for
Exposures^
None
2 times Table 13-7 but
not less than 50 feet
Not less than 50 feet
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 Built Upon,
Including the Opposite
Minimum Distance in Feet
from Nearest Side of Any
Public Way 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 Way or from
Is or Can Be Built Upon, Nearest Important
Tank Capacity Including the Opposite Building on the Same
(Gal Ions) Side of a Public Wa_y 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.e of the 1977 and 1981 editions.
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OSWER Policy Directive No. 9483.00-1
• 13-20
13.3 INCOMPATIBLE HASTES
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
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 in 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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OSHER 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
-------
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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OSWER 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.
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OSHER Policy Directive No. 9483.00-1
13-24
TABLE 13-9
LIST OF CHEMICAL CLASSES
Chemical
Class Number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16 -
"17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
Source: "A Method
(Hatayama
Class Name
Acids, mineral, non-oxidizing
Acids, mineral, oxidizing
Acids, organic
Alcohols and glycols
Aldehydes
Amides
Amines, aliphatic and aromatic
Azo compounds, diazo compounds and hydrazines
Carbamates
Caustics
Cyanides
Oithiocarbamates
Esters
Ethers
Fluorides, inorganic
Hydrocarbons, aromatic
Halogenated organics
Isocyanates
Ketones
Mercaptans and other organic sulfides
Mt,al compounds, inorganic
fr trides
Nitrites
Nitro compounds
Hydrocarbons, aliphatic, unsaturated
Hydrocarbons, aliphatic, saturated
Peroxides and hydroperoxides, organic
Phenols and cresols
Organophosphates , phosohothioates , and phosphodi thioates
Sulfides, inorganic
Epoxides
Combustible and flammable materials
Explosives
Polymerizable compounds
Oxidizing agents, strong
Reducing agents, strong
Water and mixtures containing water
Water reactive substances
for Determining the Compatibility of Hazardous Wastes"
et al., 1980).
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OSWER Policy Directive No. 9483.00-1
13-25
TABLE 13-10
LIST OF CHEMICAL REPRESENTATIVES 8Y CLASS
Class 1 Acids, mineral, non-oxidizing Class 5 Aldehydes (All Isomers)
Boric Acid
Chlorosulfonic Acid
Hydriodic Acid
Hydrobrorric Acid
Hydrochloric Acid
Hydrocyanic Acid
Hydrofluoric Acid
Hydroidic Acid
Phosphoric Acid
Class 2 Acids, mineral, oxidizing
Chloric Acid
Chromic Acid
Nitrie Acid
Oleum
PercTiloric Acid
Sulfuric Acid •
Sulfur Trioxide
Class 3 Acids, organic (All Isomers)
Acetic Acid
Benzole Acid
Formic Acid
Lactic Acid
Maleic Acid
Oleic Acid
Salycilic Acid
Phthalic Acid
Class 4 Alcohols and glycols (All
Isomers)
Allyl 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
Diethylamide
Dimethylformamide
Class 7 Amines, aliphatic and
aromatic (All Isomers)
Aminoethanol
Aniline
Diethylami ne
Diamine
Ethylenendiamine
Methyl ami ne
Monoethy1anolami ne
Pyridi ne
Class 8 Azo compounds, diazo
compounds and hydrazines
Dimethyl Hydrazine
Hydrazine
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 Dithiocarbamates '•
Class 13 Esters (All Isomers)
Butyl Acetate
Ethyl Acetate
Methyl Acrylate
Methyl Formate
Dimethyl Phthalate
Propiolaetone
Class 14 Ethers (All Isomers)
Dichloroethyl Ether
Dioxane
Ethylene Glycol Monomethyl Ether
Furan
Tetrahydrofuran
Class 15 Fluorides, inorganic
Aluminum Fluoride
Ammonium Fluoride
Fluorosi1icic Acid
Fluosi1ic Acid
Hydrofluorosi1icic Acid
Class 16 Hydrocarbons, aromatic (All
Isomers)
Benzene
Cumene
Ethyl Benzene
Naphthalene
Styrene
Toluene
Xylene
Class 17 Halogenated orqanics (All
Isomers)
Aldrin
Benzyl Chloride
Carbon Tetrachloride
Chloroacetone
Chlorobenzene
Class 17 Halogenated organics
-------
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)
Ni trobenzene
Ni trophenol
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,
organic
Benzoyl Peroxide
Hydrogen Peroxide
Chlorocresol
Coal Tar
Cresol
Creosote
Class 28 Phenols and cresols
Hydroquinone
Nitrophenol
Phenol
Picric Acid
Resorcinol
Class 29 Organophosphates, phospho-
thioates, and phosphodi-
thioates
Malathion
Parathion
Class 30 Sulfides, inorganic
Class 31 Epoxides
Epi chlorohydri n
Class 32 Combustible and flammable
materials
Diesel Oil
Gasoline
Kerosene
Naphtha
Turpenti ne
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 Hater and mixtures containing
water
Aqueous solutions and mixtures
Water
Class 38 Hater reactive substances
Acetic Anhydride
Hydrobromk 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 best 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?
t
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.
-------
OSHER 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 B
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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 inch 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
f i 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
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 paint fi Her.
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 cj/linder then the material is deemed to
contain free liquids, for purposes of 40 CFR 2E4.314 or 265.314.
Continue with Steps 7.5 through 7.7 to determine the percent free liquid
or to prepare the liquid pha-se 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 1. change between the two 15 minute readings. If the
difference is less than 101, the test is complete. If the change is greater
than 101, repeat steps 7.5 through 7.7 until the change between successive
readings is less than 107..
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OSHER Policy Directive No. 9483.00-1
B-4
Calculations:
Current Reading (ml) - Preceding Reading (m.) x 100 = 7. Change
Preceding Reading (ml)
Total Liquid Phase (ml) x 100 = T. 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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OSHER Policy Directive No. 9483.00-1
C-1
APPENDIX C
Synopsis of Pertinent EPA Guidance Manuals
"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.
"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.
"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
performi ng mi x tests.
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OSHER 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
"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.
"Recommended Prartices 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.
"Lining of Haste 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 No. 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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OSHER Policy Directive No. 9483.00-1
E-1
APPENDIX E
Tank-Specific Definitions
When used in 40 Part 264, Subpart J (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 LD 50
toxicity (rat) of less than 50 milligrams per kilogram, an inhalation 1C
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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OSHER 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 rnetal
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
affective 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 its
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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OSHER 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 Undergrounc
Storage Faci1ity
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. 948^.00-1
F-2
Appendix F (Continued)
FIGURE SOURCES
FIGURE TITLE
PAGE SOURCE
5-9
5-10
f
5-11
5-12
Sacrificial-Anode Cathodic
Protection
Factory-Installed Sacrificial-
Anode
Impressed-Current Cathodic-
Protection
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 Proper Tank Lifting and 6-5
Placement
6-2 Excavation Design: 6-8
Recommended Distance from
the Nearest Foundation
6-3 Excavation 6-9
Fred C. Hart Associates, Inc.
Petroleum Equipment Institute
"Recommended Practices for
Installation of Underground
Liquid Storage Systems,"
1986, p. 5.
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
Append"' x 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 Undergrourd
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.
-------
OSWER Policy Directive No. 9483.00-1
F-4
Appendix F (Continued)
FIGURE SOURCES
TITLE
PAGE SOURCE
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
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 Level 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
Backflow
Used to Prevent
9-7 Dover Corp., Bulletin DLLS
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 Uni versi ty ,
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,
f
5th ed. (New
Hill, 1973).
York, NY: McGraw
-------
OSWER Policy Directive No. 9483.00-1
F-6
Appendix F (Continued)
FIGURE SOURCES
FIGURE TITLE
PAGE SOURCE
9-7
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 9-18
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
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. Chilton,
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).
-------
OSHER 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
Tank Foundation
a Typical 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
Reactivi ty
13-2 40 CFR 264.17 General Require-
ments for Ignitable, Reactive
or Incompatible Wastes
13-3 Compatibi1ity Matrix
13-3 Code of Federal Regulations
13-4 Code of Federal Regulations
13-29,
30
Hatayama, et
Determining the
of Hazardous Waste
1980
aj_. , A Method for
Compati bi1i ty
U.S. EPA,
-------
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 a iven liner material is accept-
able for the intended application.
2.0 Summary of Method
2.1 In order to estimate waste/liner compatibility, tne
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 measured 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
-------
rot stirring the liquid in Che tar.k. The tanks should be compat-
ible with the waste fluia and impermeable to any of tne constitu-
ents they are intended to contain. The tank snail be equioped
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./ cover ecuipped wi.cn a reclux 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 sane as
that outside the tank. It the liner has a side that (1) is not
exposed to the waste in actual use and (2) is not designed co
withstand exposure to the chemical environment, then such a
liner may be treated with only the barrier surface exposed.
Def in i tions:
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
spec imens.
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
co be resistant to the specific wastes.
4. 5 Over, at 105 + 2°C.
4.6 Dial micrometer.
4.7 Analytical balance.
4.8 Apparatus for determining extractable content of liner
materials.
Note: A minimum quantity of representative waste fluid necessary
to con.auct this test nas not been specified in this netnoc
because tne amount will vary depending upon the waste co^-
position and the type ot liner material. For example,
certain organic waste constituents, if present in the rep-
resentative waste fluid, can be absorbed by the liner
material, thereby char.gi.iq the concentration of the chem-
icals 1.1 the waste. This change in waste composition nay
require the wasre 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 Lane
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
-------
t
cases where the waste tluid is expected to stcatity and the phases
cannot be separatee, the number of immersed samples per exposure
period car. oe increased (e.g., if the waste fluid has two phases
then 2 samples pet exposure period ate needed) so that test samples
exposed at each level of the waste can be tested. If the waste
to be contained in tie land disposal unit is in solid form,
generate a synthetic leachate.^
7.2 Perform the followina tests on unexposed samples of
the polymeric membrane line: material at 23 _+ 2°C and 50 _* 2°C.2'3
Tests for teat resistance and tensile properties are to be 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 semicr ysta 11 me liners.
1. Tear resistance, machine and transverse directions,
three specimens each direction for nonre inforced liner
materials only. See Table 1 for appropriate test metnod,
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'
V
Puncture test
Tear test specimens
Volatile* test specimen
Tensile test specimens
. Not to tcule
Figure 1 . Suggested pattern for cutting test specimens from
. nonrelnforced crossllnked or thermoplastic Immersed
Hner samples.
-------
31 Volatlles test specimen
"~
Puncture test specimens
^c -<^&?3*"«jx7?> S^^JC^S^-^.-^^ilal^i:;^.- rC? w,^>»r rT~ST-
1*^*^ v.**-'-vl^»^Sw»--«-'•' r-.'^ -^y-J.*^•>".*» '^.. - ^^ »^—
Not co scale
Figure 2 . Suggested pattern for cutting test specimens from
fabric reinforced Inmersed liner samples. Note: To
•void edge effects, cut specimens 1/8 - 1/4 inch in
from edge of Immersed sample.
-------
Tensile test specimens
Volatile* test specimen
Puncture test specimens
test specimens
Not to scale
Figure 3 . Suggested pattern for cutting test specimens from
semi crystalline immersed liner samples. Note: To
avoid edge effects, cut specimens 1/8 - 1/4 inch
in from edge of immersed sample.
-------
w
G
L
0 •
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
D - Distance between grips 2.00 inches
Figure 4 . Die for tensile dumbbell (nonreinforced
liners) having the following dimensions.
-------
reading is greater than 80), ASTM D2240. The hardness
specimen thickness for Duro A is 1/4 in. ana foe Ouro 0
is 1/3 in. The specimen dimensions ace 1 in. oy 1 in.
5. Elonaation at break. This test is only to be performed
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 sem icr ys tal 1 ine liner
materials only, ASTM 0882 modified Method A (see Table 1),
7. Volatiles content, SU 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 - 130
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 reguire 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 cynically contain 5-15% solids dissolved ir. a solvent. The
solids cor tent can be the liner formula or the base polyner.
Measure trie following:
1. Gauge thickness, in. - average of the four corners.
2. ;iass, Ib. - to one-hundretn of a Ib.
3. Length, in. - average ot the lengths of tne two sices plus
the length measured through the liner center.
4. WIG en, in. - average of the widths of the two ends pijs
the width measured through the liner center.
Do not cut tnese liner samples into the test specimen shapes
shown in Figures 1, 2, or 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 by a
wire hanger or a weignt. Different liner materials should be
immersed in separate tanks to avoid 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 and 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
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and rinse briefly with water. Place wet sample in a labelec
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 tluia at room temperature, out
in no case Later than 24 hours atter removal.
7.6 To test tae immersed sarple, wipe off any remaining
waste and rinse with :eionizea water. Blot sample dry anc
measure the following as in 7.3.
1. Gauge tnickness, in.
2. Mass, Ib.
3. Length, in.
4. Uidth, in.
7.7 Perform the following tests on the exposed samples. 2/3
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 nonre in.f orced liners,
Figure 2 for cutting patterns for reinforced liners, and Figure 3
for sen icr ys ta 11 me liners.
1. Tear 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 speec 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,
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three specimens each direction. See Table 1 for appro-
priate test method, the recommended test specimen and
speed of test, and the values to be reported. See Figure
4 for for tensile dumbbell cutting pattern dimensions tor
nonre in forced liner samples.
4. Hardness, three specimens, Duro A (Duro D if Duro A reaciny
is greater than 80), ASTM D2240. The hardness specimen
thickness for Duro A is 1/4 in. ar.a tor Duro D is 1/8 in.
The specimen dimensions are 1 in. by 1 in.
5. Elongation at .break. This test is only to be performed
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 sem icr ys tal 1 me liner
materials only, ASTM 0832 modified Method A (see Table 1).
7. Voiatiles content, SW 870 Appendix III-D.
8. Ex trac tables" content , SW 870 Appendix III-E.
9. Ply achession, machine and transverse airections, two
specimens each direction for fabric reinforced liner
materials only, ASTM D413 Machine Method, Type A - 180
degree peel.
10. Hydrostatic resistance test, ASTM D751 Method A, Procedure 1
7.3 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, and related agency
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guidance manuals.
7.8.3 Summarize the taw test results as follows:
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
appearance of water through the flexible membrane
liner for the hydrostatic resistance test.
8.0 Quality Control
8.1 Determine the mechanical properties of identical
r.onimmersed 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 Characteristic Leaching Proce-
dure (TCLP) tnat was proposed in the Federal Register or. Jur.e
13, 1936, Vol. 51, No.114, pg . 21685.
2) For semicr ys tal 1 me membrane liners, the Agency suggests the
determination of the potential for environmental stress
cracking. The test that can be used to make this deterninacio:
is either ASTM 01693 or the National Bureau of Standards
Constant Tensile Load. The evaluation of the results should
be provided by an expect 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" D3083 can be used and for reinforced FMLs,
the test ASTM D751, Grab Methoa, 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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TABLE: 2. POLYMERS USED IN FLEXIBLE .MEMBRANE LINERS
Thermoplastic Materials (IP.)
CPE (Chlorinated polyethylene)3
Family ot polymers produced by chemical reaction of chlorine
on polyethylene. The resulting thermoplastic elastomers
contain 25 to 45s chlorine by weight and 0 to 25% crystal-
Unity.
CSPE (Chlocosulfonatea polyethylene)3
Family of polymers that are produced by polyethylene reacting
with chlorine and -sulfur dioxide and usually containing
25 to 43%' chlorine and l.Q to 1.4% sulfur, Chlorosulfonatea
polyethylene is also known as hypalon.
EIA (Ethylene ir. tec polymer alloy)3
A blend of EVA and polyvinyl cnioride resulting in a thermo-
plastic elastomer.
?VC (Polyvinyl chlorice)3
A synthetic thermoplastic polymer made by polymerizing vinyl
chloride monomer, or vinyl chloride/vinyl acetate monomers.
Normally rigid and containing 50% of plast ic i zer s .
PVC-CPE (Polyvinyl chloride - chlorinated polyethylene alloy)3
A blend of polyvinyl chloride and chlorinated polyethylene.
TN-PVC (Thermoplastic nitrile-polyv inyl choloride)3
An alloy of thermoplastic unvulcanized nitrile rubber and
polyvinyl chloride.
-------
12
TABLE 2. (Continued)
Vulcan zed Materials (XL)
Butyl rubce:a
A synthetic rubber based on isobutylene and a small ar.ount
of isoprene to prcvice sites for vulcanization.
EPDM (Etnylene propylene diene mononer)a,°
A synthetic elastomer basea on ethylene, ptopylene, and a
snail amount of nonconjugated diene to provide sites no;
v j 1 c a n i za 11 o n .
CM (Crosslinkec cnlorir.ated polyethylene)
No definition available by EPA.
CO, ECO ( Ep ichlorohyd r in 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 ep ic.nlorohycr in
and ethylene oxide (ECO).
CR (Polychloropiene)a
Generic name for a synthetic rubber based primarily on
ch lorobutadiene. Polychlocoprene is also known as neoprene.
aAlso supplied reinforced with fabric.
^Also supplied as a thermoplastic.
Semicrystalline Materials (CX)
HOPE (High density polyethylene)
A polymer prepared by the low-pressure polyneri zaton of
ethylene as the principal monomer.
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13
TABLE 2. (Continued)
HOPE - A (Hiqh density polyethylene/rubber alloy)
A blend of high-density polyethylene and rubber,
LLDPE (Linear: low-density polyethylene)
A low-density polyethylene produced by the copolymeri-
zation of ethylene with various alpha olefins in the pres-
ence ot suitable catalysts.
PEL (Polyester elastomer)
A segmented thermoplastic copolyester elastomer containing
recurring long chain ester units derived from d icarboxyl. ic
acids and long chain glycols and short chain ester units
derived from dicarboxylic acids and low molecular weight
d iols.
PE-EP-A (Polyethylene ethylen.e/pr opylene alloy)
A blend of polyethylene and ethylene and propylene polyner
resulting in a thermoplastic elastomer.
T-EPDM (Ther.-noplastic EPDM)
An ethylene-propylene diene monomer blend resulting in a
thermoplastic elastomer.
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OSHER Policy Directive No. 9483.00-1
Bibliography Page 1.
BIBLIOGRAPHT
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).
t
9. American Concrete- 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 B31.4 (1980).
15. American National Standards Institute, "Standard for Welded Aluminum-Alloy
Storage Tanks," ANSI 896.1 (1981).
16. American Petroleum Institute, "Specification for Field Welded Tanks for
Storage of Production Liquids," 8th Ed., API 12D (1982).
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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, Welded, 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
Associated With Tank Entry and Cleaning," API 2015A (1985).
30. American Petroleum Institute, "Cleaning Open-Top and Covered Floating-Roof
Tanks," API 2015B (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).
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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
PldStic Underground' Storage Tanks for Petroleum Products," UL 1316
(1983).
70. U.S. Environmental Protection Agency, Office of Emergency and Remedial
Response, "Standard Operating Safety Guidelines," (1984).
71. U.S. Environmental Protection Agency, Office of Research and Development,
Release Control Branch, "Underground Tank Leak Detection Methods: A State
of the Art Review," Contract No. 68-03-3069 (1985).
72. U.S. Environmental Protection Agency, Office of Solid Waste and Emergency
Response, "RCRA Ground Water Monitoring Technical Enforcement Guidance
Document," (1985) (Draft).
73. U.S. Environmental Protection Agency, Office of Solid Waste and Emergency
Response, "A Compatibility Guide for Regulated/Hazardous Chemical
Substances and Underground Storage Tanks-Draft Technical Report," Contract
No. 68-01-7053 (1985).
74. U.S. Environmental Protection Agency, Office of Water Regulations and
Standards, "Expected Life of Synthetic Liners and Caps," Contract No.
68-10-6160 (1983).
75. U.S. Environmental Protection Agency, Defies of Solid Was.te and Emergency Re- '
sponse, "Technical Resource Document for Obtaining Variances from the Second-
ary Containment Requirement for Tank Systems for Hazardous Waste Tanks Vol-
ume 1: Technology-Based Variances," OS :R Policy Directive No. 9483.00-2
(1986).
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r
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 D-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
of the Behavior of Underground Tanks," (1982).
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
Procedures Manual," MD489/D335 (1983).
43. Merck, "The Merck Index," 10th Ed., (1983).
44. National Association of Corrosion Engineers, "Recommended Practice-Control
of External Corrosion on Underground or Submerged Metallic Piping
Systems," NACE RP-01-69 (1983).
45. National Association of Corrosion Engineers, "Recommended
Practice - Mitigation of Alternating Current and Lightning Effects on
Metallic Structures and Corrosion Control Systems," NACE RP-01-77.
46. National Association of Corrosion Engineers, "Recommended Practice-Control
of External Corrosion on Metallic Buried, Partially Buried or Submerged
Liquid Storage Systems," NACE RP-02-85 (1985).
47. National Institute of Occupational Safety and Health, "Working in Confined
Spaces," NIOSH 80-106 (1979).
48. National Fire Protection Association, "Flammable and Combustible Liquids "
NFPA Standard 30, (1984).
49. National Fire Protection Association, "National Electrical Code," NFPA 70
(1984).
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OSWER Policy Directive No. 9483.00-1
Bib!iography Page 4.
50. National Fire Protection Association, "Static Electricity," NFPA 77
(1983).
51. National Fire Protection Association, "Lightning Protection Code," NFPA 78
(1983).
52. National Fire Protection Association, "Standard Procedures for Cleaning or
Safeguarding Small Tanks and Containers," NFPA 327 (1982).
53. National Fire Protection Association, "Loading and Unloading of Tank
Vehicles," NFPA 385 (1985).
54. National Fire Protection Association, "Fire Protection Guide on Hazardous
Materials," NFPA SPP-1E (1984).
55. National Sanitation Foundation, "Flexible Membrane Liners," NSF Standard
54 (1983).
56. Owens-Corning, "Fiberglas Underground Tank Installation Techniques
Manual," (1984).
57. Perry, R.H., C.H. Chllton, "Chemical Engineers' Handbook," (1973).
58. Petroleum Equipment Institute, "Recommended Practices for Installation of
Underground Liquid Storage Systems," PEI/RP100-85 (1985) (Draft).
59. Pludek, V.R., "Design and Corrosion Control," (1977).
60. Portland Cement Association, "Effects of Substances on Concrete and Guide
to Protective Treatment," (1981).
61. Post-tensioning Institute, "Design and Construction of Post-tensioned
Slabs-on-Ground," (1986).
62. Powers, J.P., "Construction Dewatering, A Guide to Theory and Practice,"
(1981).
63. Prestressed Concrete Institute, "Guide Specification for Prestress Precast
Concrete for Buildings," SPC-118-85 (1985).
64. Sax, N.I., "Dangerous Properties of Industrial Materials," 6th Ed.,
(1984).
65. Steel Tank Institute, "Standard for Dual Wall Underground Steel Storage
Tanks" (1985).
66. Underwriters Laboratories, Inc., "Standard for Steel Underground Tanks for
Flammable and Combustible Liquids," UL 58 (1976).
67. Underwriters Laboratories, Inc., "Standard for Steel Inside Tanks for Oil
Burner Fuel," UL 80 (1980).
U.S. Erv/'rcnrnentai .^rotecl'on Agenc
Region 5,Li!:r«3ry (PM2J)
77 West Jdc/.son Boulevard 12ih
Chicago, IL 60604-5590
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