Installation of Underground Petroleum Storage Systems

API RECOMMENDED PRACTICE 1615 SIXTH EDITION, APRIL 2011

REAFFIRMED, MAY 2020

Installation of Underground Petroleum Storage Systems

Marketing Segment

API RECOMMENDED PRACTICE 1615 SIXTH EDITION, APRIL 2011

REAFFIRMED, MAY 2020

Special Notes

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API publications are published to facilitate the broad availability of proven, sound engineering and operating practices. These publications are not intended to obviate the need for applying sound engineering judgment regarding when and where these publications should be utilized. The formulation and publication of API publications is not intended in any way to inhibit anyone from using any other practices.

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Copyright © 2011 American Petroleum Institute

Foreword

Nothing contained in any API publication is to be construed as granting any right, by implication or otherwise, for the manufacture, sale, or use of any method, apparatus, or product covered by letters patent. Neither should anything contained in the publication be construed as insuring anyone against liability for infringement of letters patent.

This document was produced under API standardization procedures that ensure appropriate notification and participation in the developmental process and is designated as an API standard. Questions concerning the interpretation of the content of this publication or comments and questions concerning the procedures under which this publication was developed should be directed in writing to the Director of Standards, American Petroleum Institute, 1220 L Street, NW, Washington, DC 20005. Requests for permission to reproduce or translate all or any part of the material published herein should also be addressed to the director.

Generally, API standards are reviewed and revised, reaffirmed, or withdrawn at least every five years. A one-time extension of up to two years may be added to this review cycle. Status of the publication can be ascertained from the API Standards Department, telephone (202) 682-8000. A catalog of API publications and materials is published annually by API, 1220 L Street, NW, Washington, DC 20005.

Suggested revisions are invited and should be submitted to the Standards Department, API, 1220 L Street, NW, Washington, DC 20005, standards@api.org.

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Contents

Page

1. Scope 1

2. Definitions and Acronyms 1

3. Referenced Publications 13

   1. Informative References 13

   2. Other Laws and Regulations 17

4. Safety and Health 17

   1. General 17

   2. Contractor Work Safety 17

   3. Emergency Response 19

5. Materials and Equipment 19

   1. General 19

   2. Federal Requirements 19

   3. Material Specifications 20

   4. Total Cost of Ownership (TCO) 20

6. Preconstruction and Preinstallation Site Analysis 21

   1. General 21

   2. Secondary Containment 21

7. Removal and Disposal of Used Storage Systems 21

   1. Safety Considerations. 21

   2. Considerations for Partial System Removal 22

   3. Contaminated Backfill 23

   4. Disposal of Used Equipment 23

8. Excavation 23

   1. General 23

   2. Safety Considerations. 23

   3. Location of Tanks 23

   4. Excavation Dimensions 25

9. Handling, Inspection and Testing 27

   1. Material Handling 27

   2. Pre-installation Inspection and Testing 28

   3. Testing—General 30

   4. Safety Precautions 30

   5. Pressure Testing of Single-wall Tanks 30

   6. Pressure Testing of Double-Wall Tanks 32

   7. Testing of Piping and Sumps 33

10. Equipment Placement, Anchorage, Secondary Containment, and Ballasting 33

    1. Placement 33

    2. Tank Buoyancy 34

    3. Anchorage 35

    4. Ballasting 37

11. Backfilling 38

    1. General 38

    2. Pipe Tightness Test 38

    3. Placement of Materials and Compaction of Backfill 38

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       Contents

       Page

    4. Covering 39

    5. Grading and Paving 40

    6. Post-backfill Inspection of FRP Tanks 40

12. Pumping Systems Design 40

    1. General 40

    2. Pressure Pumping Systems 41

    3. Suction Pumping Systems 41

    4. Other Factors 41

    5. Tank Fittings 42

    6. Identification of Driveway Manways 42

13. Piping 43

    1. General 43

    2. Layout and Design 43

    3. Vent Piping 45

    4. Fiberglass-Reinforced Plastic (FRP) Piping 48

    5. Steel Piping 48

    6. Flexible and Semi-flexible Plastic Piping 49

    7. Pipe Connections 49

    8. Pipe Tightness Testing 50

14. Overfill Protection and Spill Containment 50

15. Corrosion Protection 55

    1. General 55

    2. Sacrificial Anode System 56

    3. Testing 57

16. Electrical 57

    1. General 57

    2. Equipment Selection 57

    3. Emergency Disconnects 57

    4. Intrinsically Safe 58

    5. Connections 58

17. Vapor Recovery 58

    1. General 58

    2. Stage I Vapor Recovery 59

    3. Stage II Vapor Recovery 60

    4. Equipment 60

    5. System Design 61

18. Detection of Releases 61

    1. General 61

    2. Federal Requirements—General 61

    3. Leak Detection Methods—Requirements 61

    4. Leak Detection Certification 67

    5. Technical Considerations 67

19. Final Testing 67

Contents

Page

Annex A (informative) UST System Installation Documents Checklist 69

Annex B (informative) Sample Buoyancy Calculation 70

Annex C (informative) Optional UST System Checklist 72

Figures

1. Sample UST System—Secondary Containment 22

2. Tank Excavation Clearance from Existing Structures 24

3A Example of Shoring System for Unstable Soil Conditions 24

3B Example of Pre-engineered Shoring System for Unstable Soil Conditions 25

1. Typical Plot Plan Showing Typical Tank Placements 26

2. Proper Rigging for Lifting and Lowering Tanks 27

3. Typical “Holiday” Test for Steel USTs 29

4. Typical Pressure/Soap Test for FRP USTs 29

5. Pressure Test Gauge Setup for Single-wall Tanks 31

6. Pressure Test Gauge Setup for Double-wall Tanks 32

7. Backhoe Boom Swing Radius Exclusion Zone 34

8. Proper Tank Alignment 35

9. Typical Anchorage for Underground Storage Tanks 36

10. Typical Anchorage for Underground Storage Tanks 37

11. Piping Backfill and Burial Details 39

12. Depth of Covering Over Tanks and Excavation 40

13. Typical Piping Configurations 44

14. Piping Slope Details 45

15. Piping Manifold Configurations 46

16. Typical Vent Piping Details 47

17. Typical Piping Tightness Test Gauge Setup 51

21A Typical Spill Containment Device 52

21B Typical Overfill Spill Containment Detail with Secondary Containment 53

1. Typical Flapper Valve 54

2. Stray Current Corrosion 56

3. Sacrificial Anode Cathodic Protection 56

4. Typical Vapor Recovery System 58

5. Typical Leak Detector or Pressure Transducer 63

6. Example of a Functional Test Apparatus for Mechanical Line Leak Detectors 64

7. Typical Interstitial Monitoring Systems (Tanks, Piping, and Sumps) 65

8. Typical Observation Well Used Within the Tank Excavation 66

B.1 Buoyancy Calculation—15,000 Gallon Tank 71

Introduction

The proper installation of an UST system can contribute toward ensuring that the maximum utilization of the various components and equipment comprising an UST system are achieved at the lowest total cost of ownership. This will help prevent, as well as reduce, the frequency and magnitude of releases that may result from equipment failure or malfunction.

The benefits from proper installation include, but are not limited to, improved protection of the environment and reduced environmental liabilities for the UST system owner and operator.

Construction plans and written documents are often required for obtaining permits, soliciting bids, and providing precise guidance for installers. Obtaining and providing the following documentation is the responsibility of various stakeholders (e.g. general contractors, electrical contractors, equipment manufacturers, environmental assessment contractors, regulatory agencies, etc.). Those responsibilities can be designated during initial construction planning meetings with the UST owner and operator. (See also Annex A—”UST System Installation Documents Checklist”)

The choice of proper equipment and materials is necessary to help provide long-term system operation and integrity. Installation checklists tailored to the intended installation site provide a convenient method for planning and documenting work. Any municipal, county, or state codes and regulations, as well as nationally-recognized industry standards or recommended practices that address the installation of the UST system should also be referenced and/ or included in the document package. Any other requirements specific to local conditions that may provide information regarding safety and/or environmental considerations during construction should also be included. (See also Annex A—”UST System Installation Checklist” of items discussed in this Introduction)

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Installation of Underground Petroleum Storage Systems

1. Scope

   1. This Recommended Practice (RP) is a guide to procedures and equipment that should be used for the proper installation of underground storage systems for bulk petroleum products or used oil at retail and commercial facilities. The stored products include gasoline, diesel fuel, kerosene, lubricating oils, used oil, and certain bio-fuel blends. (For information on alcohol/gasoline blends, see API 1626. The product manufacturer and the authority having jurisdiction (AHJ) should be consulted with regard to the proper storage of all products.)

      
      

      NOTE All drawings provided in this document are for reference and illustration purposes only. Drawings are not to scale and may not reflect exact details of UST system configurations, components and equipment provided by manufacturers. For exact specifications and details of components and equipment consult the manufacturer(s).

      
      

   2. This RP is intended for use by architects, engineers, tank owners, tank operators, and contractors. Contractors, engineers, and owners or operators who are preparing to design or install an UST system should investigate the federal, state, and local requirements and current methods of compliance for vapor recovery in that region. Vapor recovery is covered in detail in Section 17 of this document. For more information on the design and installation of vapor recovery systems, see NFPA 30A, and PEI RP 300

      
      

      NOTE An AHJ may reference different codes.

      
      

   3. This RP is not intended to cover specialized installations, such as fuel storage systems at marinas or airports, heating oil storage systems (either residential or bulk), or systems installed inside buildings. However, it does outline recognized and generally accepted good engineering practices which may be of use for these specialized installations. This RP does not apply to the installation of below ground or above ground bulk storage systems greater than 60,000 gal. The reader is referred to the following standards for information on specialized storage systems:

      
      

      1. marinas: NFPA 30A and PEI RP 1000;

         
         

      2. residential storage of heating oil: NFPA 31;

         
         

      3. storage inside buildings: NFPA 30;

         
         

      4. bulk storage—general: PEI RP 800;

         
         

      5. aboveground storage: NFPA 30, NFPA 30A, API 650, API 651, API 652, API 653, API 2601, and PEI RP 200.

      
      

      NOTE An AHJ may reference different codes.

      
      

   4. This RP shall not preempt any federal, state, or local laws and regulations; specifically, those referenced in 3.2.

      
      

2. Definitions and Acronyms

For the purposes of this document, the following definitions and acronyms apply:

2.1

ACGIH

American Conference of Governmental Industrial Hygienists

2.2

anode

The positive electrode from which electrons leave a device and corrosion occurs.

1