ASTM G158-98(2021)
(Guide)Standard Guide for Three Methods of Assessing Buried Steel Tanks
Standard Guide for Three Methods of Assessing Buried Steel Tanks
SIGNIFICANCE AND USE
4.1 This guide provides three methods for determining the suitability of a buried steel tank to be upgraded with cathodic protection.
4.2 This guide may be used to assess any UST, including non-regulated USTs.
4.3 This guide provides three alternative methods but does not recommend any specific method or application. The responsibility for selection of a method rests with the user.
4.4 This guide has specific requirements for vendor provided information which should be requested and reviewed by the user.
SCOPE
1.1 This guide covers procedures to be implemented prior to the application of cathodic protection for evaluating the suitability of a tank for upgrading by cathodic protection alone.
1.2 Three procedures are described and identified as Methods A, B, and C.
1.2.1 Method A—Noninvasive with primary emphasis on statistical and electrochemical analysis of external site environment corrosion data.
1.2.2 Method B—Invasive ultrasonic thickness testing with external corrosion evaluation.
1.2.3 Method C—Invasive permanently recorded visual inspection and evaluation including external corrosion assessment.
1.3 This guide presents the methodology and the procedures utilizing site and tank specific data for determining a tank’s condition and the suitability for such tanks to be upgraded with cathodic protection.
1.4 The tank's condition shall be assessed using Method A, B, or C. Prior to assessing the tank, a preliminary site survey shall be performed pursuant to Section 8 and the tank shall be tightness tested pursuant to 5.2 to establish that the tank is not leaking.
1.5 While this guide provides minimum procedures for assessing a tank's condition, this guide does not provide minimum installation procedures or requirements for upgrades of the tank by cathodic protection.
1.6 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.
1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.8 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
General Information
Relations
Buy Standard
Standards Content (Sample)
This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: G158 − 98 (Reapproved 2021)
Standard Guide for
Three Methods of Assessing Buried Steel Tanks
This standard is issued under the fixed designation G158; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
INTRODUCTION
The purpose of this guide is to provide three methods of inspecting and assessing buried steel
tank(s) for corrosion damage and determining the suitability of these tanks prior to application of
cathodic protection.
1. Scope conversions to SI units that are provided for information only
and are not considered standard.
1.1 Thisguidecoversprocedurestobeimplementedpriorto
1.7 This standard does not purport to address all of the
the application of cathodic protection for evaluating the suit-
safety concerns, if any, associated with its use. It is the
ability of a tank for upgrading by cathodic protection alone.
responsibility of the user of this standard to establish appro-
1.2 Three procedures are described and identified as Meth-
priate safety, health, and environmental practices and deter-
ods A, B, and C.
mine the applicability of regulatory limitations prior to use.
1.2.1 Method A—Noninvasive with primary emphasis on
1.8 This international standard was developed in accor-
statistical and electrochemical analysis of external site envi-
dance with internationally recognized principles on standard-
ronment corrosion data.
ization established in the Decision on Principles for the
1.2.2 Method B—Invasive ultrasonic thickness testing with
Development of International Standards, Guides and Recom-
external corrosion evaluation.
mendations issued by the World Trade Organization Technical
1.2.3 Method C—Invasive permanently recorded visual in-
Barriers to Trade (TBT) Committee.
spection and evaluation including external corrosion assess-
ment.
2. Referenced Documents
1.3 This guide presents the methodology and the procedures
2.1 The most recent version of the following documents
utilizing site and tank specific data for determining a tank’s
should be consulted as references by those using this guide:
condition and the suitability for such tanks to be upgraded with
2.2 ASTM Standards:
cathodic protection.
D2216 Test Methods for Laboratory Determination of Water
1.4 The tank’s condition shall be assessed using MethodA,
(Moisture) Content of Soil and Rock by Mass
B, or C. Prior to assessing the tank, a preliminary site survey
E114 Practice for Ultrasonic Pulse-Echo Straight-Beam
shall be performed pursuant to Section 8 and the tank shall be
Contact Testing
tightness tested pursuant to 5.2 to establish that the tank is not
E797/E797M Practice for Measuring Thickness by Manual
leaking.
Ultrasonic Pulse-Echo Contact Method
1.5 While this guide provides minimum procedures for E1323 Guide for Evaluating Laboratory Measurement Prac-
assessing a tank’s condition, this guide does not provide
tices and the Statistical Analysis of the Resulting Data
minimum installation procedures or requirements for upgrades E1526 Practice for Evaluating the Performance of Release
of the tank by cathodic protection.
Detection Systems for Underground Storage Tank Sys-
tems (Withdrawn 2002)
1.6 The values stated in inch-pound units are to be regarded
G51 Test Method for Measuring pH of Soil for Use in
as standard. The values given in parentheses are mathematical
Corrosion Testing
1 2
This guide is under the jurisdiction ofASTM Committee G01 on Corrosion of For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Metals and is the direct responsibility of Subcommittee G01.10 on Corrosion in contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Soils. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved Aug. 1, 2021. Published August 2021. Originally the ASTM website.
approved in 1998. Last previous edition approved in 2016 as G158 – 98 (2016). The last approved version of this historical standard is referenced on
DOI: 10.1520/G0158-98R21. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
G158 − 98 (2021)
G57 Test Method for Measurement of Soil Resistivity Using 3.1.4 corrosion technician—a person possessing basic
the Wenner Four-Electrode Method knowledge of corrosion and corrosion control, who is capable
4 of performing routine, well defined work under the supervision
2.3 ASNT Standard:
of the corrosion specialist/cathodic protection specialist.
ASNT SNT-TC-1A Personnel Qualification and Certifica-
tion in Nondestructive Testing
3.1.5 invasive procedure—a method of determining the
corrosion status of a tank by assessing the tank from the inside
2.4 NACE International Standards:
as part of the upgrade procedure. Further, for the purposes of
RP-0169 Standard Recommended Practice-Control on Ex-
this guide, it does not require manned entry into the tank. (See
ternal Corrosion on Underground or Submerged Metallic
non-invasive.)
Piping Systems
RP-0187 Standard Recommended Practice-Design Consid-
3.1.6 limitations—The user of this guide is encouraged to
erations for Corrosion Control of Reinforcing Steel in
review any available third party verification information pro-
Concrete
vided as part of the vendor selection process.
RP-0285 Standard Recommended Practice-Corrosion Con-
3.1.7 noninvasive procedure—a method of determining the
trol of Underground Storage Tank Systems by Cathodic
corrosion status of a tank from the characteristics of its
Protection
surroundings with minimal entry into the tank. Further, for the
2.5 Environmental Protection Agency Methods:
purposes of this guide, it does not require manned entry into
EPA SW 846 Test Methods for Evaluating Solid Waste
the tank. (See invasive.)
EPA 371.1 Measurement of Sulfate Reducing Bacteria
3.1.8 pH—the numerical value of the negative logarithm of
2.6 National Fire Protection Association (NFPA) Practice:
the hydrogen ion concentration in moles per litre in an
NFPA 329 Recommended Practice for Handling Under-
electrolyte.
ground Releases of Flammable and Combustible Liquids
3.1.9 redox potential—potential of platinized platinum elec-
2.7 Underwriters Laboratories Standard:
trode in a redox environment (reversible system). The value of
UL 58 Steel Underground Tanks for Flammable and Com-
redox potential depends on whether the system is in the
bustible Liquids
oxidized, partially oxidized, partially reduced, or reduced state.
3.1.10 tank tightness test—a method capable of detecting a
3. Terminology
0.1 gal/h leak rate, while accounting for any applicable effects
3.1 Definitions of Terms Specific to This Standard:
of thermal expansion or contraction of the product, of vapor
3.1.1 buried—to be placed in the ground and covered with
pockets, of tank deformation, of evaporation or condensation,
earth.
and of the location of the water table. The method must be
3.1.2 cathodic protection—an applied technique to prevent capable of detecting a 0.1 gal/h leak rate with a probability of
detection of at least 0.95 and a probability of false alarm of at
further corrosion of a metal surface by making that surface the
cathode of an electrochemical cell. For example, a tank system most 0.05 or in accordance with NFPA 329.
can be cathodically protected through the application of either
3.1.11 unconditional probability of corrosion failure—the
galvanic anodes or impressed current.
probability of corrosion failure which includes a determination
3.1.3 corrosion specialist/cathodic protection specialist—a
of whether localized, pitting, or general corrosion is occurring.
competent person who by reason of knowledge of the physical
3.1.12 underground storage tank (UST)—any one or com-
sciences and the principles of engineering and mathematics,
bination of tanks (including connected underground piping),
acquired by education and related practical experience, is
thevolumeofwhichis10 %ormorebeneaththesurfaceofthe
qualified to engage in the practice of corrosion control on
ground.
buried or submerged metallic piping systems and metallic
3.1.13 upgrade—the addition to or retrofit of UST systems
tanks. Such persons shall be registered professional engineers
using approaches including, but not limited to, cathodic pro-
or persons recognized as corrosion specialists or cathodic
tection to improve the ability of a UST system to prevent a
protection specialists by NACE, if their professional activities
release.
include suitable experiences in external corrosion control on
buried or submerged metallic piping and tanks.
3.1.14 UST—see underground storage tank (see 3.1.12).
3.1.15 vendor provided information—The user is referred to
AnnexA1 for a specific form and format of information which
AvailablefromAmericanSocietyforNondestructiveTesting(ASNT),P.O.Box
must be provided by a vendor. This information consists of
28518, 1711 Arlingate Ln., Columbus, OH 43228-0518, http://www.asnt.org.
historic performance data on a method and is mandated as part
Available from NACE International (NACE), 15835 ParkTen Pl., Houston,TX
77084, http://www.nace.org. of the guide.
Available from United States Environmental Protection Agency (EPA), Office
of Underground StorageTanks,William Jefferson Clinton Bldg., 1200 Pennsylvania
4. Significance and Use
Ave., NW, Washington, DC 20460, http://www.epa.gov.
Available from National Fire Protection Association (NFPA), 1 Batterymarch
4.1 This guide provides three methods for determining the
Park, Quincy, MA 02269-9101.
suitability of a buried steel tank to be upgraded with cathodic
Available from Underwriters Laboratories (UL), UL Headquarters, 333 Pfing-
sten Road, Northbrook, IL, 60062, http://www.ul.com. protection.
G158 − 98 (2021)
4.2 This guide may be used to assess any UST, including 8.1.2.1 Number and capacity,
non-regulated USTs. 8.1.2.2 Location and dimensions,
8.1.2.3 Age,
4.3 This guide provides three alternative methods but does
8.1.2.4 Material of construction,
not recommend any specific method or application. The
8.1.2.5 Electrical isolation,
responsibility for selection of a method rests with the user.
8.1.2.6 Type of product stored,
4.4 This guide has specific requirements for vendor pro-
8.1.2.7 Names of site contact personnel,
vided information which should be requested and reviewed by
8.1.2.8 Backfill material,
the user.
8.1.2.9 Coatings and linings,
8.1.2.10 Leak history,
5. Permits, Plans and Tank Leak Testing
8.1.2.11 Repair history,
5.1 Prior to engaging in any activities relating to the
8.1.2.12 Site plans,
alteration, repair, or upgrade of any UST system, consult all 8.1.2.13 Installation specifications,
necessary authorities to obtain any required permits.
8.1.2.14 Tank excavation liners, and
8.1.2.15 As-built drawings.
5.2 Tank Leak Testing:
8.1.3 Information Not in the Immediate Vicinity of the
5.2.1 To establish that tanks are not leaking prior to
Tanks—The presence of the following items, that are external
assessment, they shall be assessed by a leak detection system.
to the tank area, shall be investigated and included as appro-
This leak detection assessment alone is not sufficient to
priatetothemethodofassessmentofthesuitabilityoftanksfor
determine that a tank is suitable for upgrading with cathodic
upgrading with cathodic protection:
protection under this guide.
8.1.3.1 Stray dc current sources,
5.2.2 Atightness test or another release detection system in
8.1.3.2 Existing cathodic protection systems,
accordancewithNFPA329shallbeused.Anyreleasedetection
8.1.3.3 Steel product and vent piping and fittings, and
must be capable of detecting a leak from any portion of the
8.1.3.4 Adjacent subsurface metallic/steel-reinforced con-
tank that routinely contains product, and be independently
crete structures.
evaluated and certified in accordance with Practice E1526 or
the equivalent. Leak detection results shall be provided to the
8.2 Preliminary Evaluation—Prior to assessing the tank, a
corrosion specialist/cathodic protection specialist.
preliminary site survey must be performed pursuant to Section
5.2.3 This testing shall be accomplished within six months
8 and a tightness test must be performed pursuant to 5.2 to
prior to performing any of the assessment procedures.
establish that the tank is not leaking.
6. Required Approvals and Certifications
9. Method A—Noninvasive with Primary Emphasis on
Statistical and Electrochemical Analysis of External
6.1 The corrosion assessment work carried out under this
Site Environment Corrosion Data (1, 2)
guide shall be performed under the responsible direction of a
corrosion specialist/cathodic protection specialist as defined in
9.1 Field and Laboratory Testing—Noninvasive with Pri-
3.1.3.
mary Emphasis on Statistical and Electrochemical Analysis of
External Site Environment Corrosion Data.
6.2 The corrosion specialist/cathodic protection specialist
9.1.1 Tests shall be conducted by, or as directed by a
shall certify to the tank owner or operator that the personnel
corrosion specialist/cathodic protection specialist.
performingtheassessmentworkonthetankareknowledgeable
9.1.2 Field Testing Procedures—Tests to be performed shall
of all the applicable procedures in this guide.
include, but are not limited to, the following:
6.3 The corrosion specialist/cathodic protection specialist
9.1.2.1 Stray Currents—Perform tests to detect the presence
shall certify to the tank owner or operator that all work was
of stray currents at each tank site. This test shall consist of
performed in strict accordance with this guide.
measuring structure-to-soil potentials at right angles at a
minimum of two locations within the tank facilities and
7. General Safety Requirements
observing the measurements for not less than2hata time
7.1 All personnel shall comply with applicable federal,
when such influences are most likely to occur. The monitor
state, and local health and safety codes and regulations.
shall consist of a field data acquisition unit, with a minimum of
10 MΩ input impedance, used in conjunction with a stable
8. Preliminary Site Survey
reference cell(s) placed in contact with the soil in the vicinity
8.1 A corrosion technician, under the responsible direction of the tank. The instrument shall measure and store structure-
of the corrosion specialist/cathodic protection specialist, shall to-electrol
...
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: G158 − 98 (Reapproved 2021)
Standard Guide for
Three Methods of Assessing Buried Steel Tanks
This standard is issued under the fixed designation G158; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
INTRODUCTION
The purpose of this guide is to provide three methods of inspecting and assessing buried steel
tank(s) for corrosion damage and determining the suitability of these tanks prior to application of
cathodic protection.
1. Scope conversions to SI units that are provided for information only
and are not considered standard.
1.1 This guide covers procedures to be implemented prior to
1.7 This standard does not purport to address all of the
the application of cathodic protection for evaluating the suit-
safety concerns, if any, associated with its use. It is the
ability of a tank for upgrading by cathodic protection alone.
responsibility of the user of this standard to establish appro-
1.2 Three procedures are described and identified as Meth-
priate safety, health, and environmental practices and deter-
ods A, B, and C.
mine the applicability of regulatory limitations prior to use.
1.2.1 Method A—Noninvasive with primary emphasis on
1.8 This international standard was developed in accor-
statistical and electrochemical analysis of external site envi-
dance with internationally recognized principles on standard-
ronment corrosion data.
ization established in the Decision on Principles for the
1.2.2 Method B—Invasive ultrasonic thickness testing with
Development of International Standards, Guides and Recom-
external corrosion evaluation.
mendations issued by the World Trade Organization Technical
1.2.3 Method C—Invasive permanently recorded visual in-
Barriers to Trade (TBT) Committee.
spection and evaluation including external corrosion assess-
ment.
2. Referenced Documents
1.3 This guide presents the methodology and the procedures
2.1 The most recent version of the following documents
utilizing site and tank specific data for determining a tank’s
should be consulted as references by those using this guide:
condition and the suitability for such tanks to be upgraded with
2.2 ASTM Standards:
cathodic protection.
D2216 Test Methods for Laboratory Determination of Water
1.4 The tank’s condition shall be assessed using Method A,
(Moisture) Content of Soil and Rock by Mass
B, or C. Prior to assessing the tank, a preliminary site survey
E114 Practice for Ultrasonic Pulse-Echo Straight-Beam
shall be performed pursuant to Section 8 and the tank shall be
Contact Testing
tightness tested pursuant to 5.2 to establish that the tank is not
E797/E797M Practice for Measuring Thickness by Manual
leaking.
Ultrasonic Pulse-Echo Contact Method
1.5 While this guide provides minimum procedures for E1323 Guide for Evaluating Laboratory Measurement Prac-
assessing a tank’s condition, this guide does not provide tices and the Statistical Analysis of the Resulting Data
minimum installation procedures or requirements for upgrades
E1526 Practice for Evaluating the Performance of Release
of the tank by cathodic protection. Detection Systems for Underground Storage Tank Sys-
tems (Withdrawn 2002)
1.6 The values stated in inch-pound units are to be regarded
G51 Test Method for Measuring pH of Soil for Use in
as standard. The values given in parentheses are mathematical
Corrosion Testing
1 2
This guide is under the jurisdiction of ASTM Committee G01 on Corrosion of For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Metals and is the direct responsibility of Subcommittee G01.10 on Corrosion in contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Soils. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved Aug. 1, 2021. Published August 2021. Originally the ASTM website.
approved in 1998. Last previous edition approved in 2016 as G158 – 98 (2016). The last approved version of this historical standard is referenced on
DOI: 10.1520/G0158-98R21. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
G158 − 98 (2021)
G57 Test Method for Measurement of Soil Resistivity Using 3.1.4 corrosion technician—a person possessing basic
the Wenner Four-Electrode Method knowledge of corrosion and corrosion control, who is capable
of performing routine, well defined work under the supervision
2.3 ASNT Standard:
of the corrosion specialist/cathodic protection specialist.
ASNT SNT-TC-1A Personnel Qualification and Certifica-
tion in Nondestructive Testing 3.1.5 invasive procedure—a method of determining the
corrosion status of a tank by assessing the tank from the inside
2.4 NACE International Standards:
as part of the upgrade procedure. Further, for the purposes of
RP-0169 Standard Recommended Practice-Control on Ex-
this guide, it does not require manned entry into the tank. (See
ternal Corrosion on Underground or Submerged Metallic
non-invasive.)
Piping Systems
RP-0187 Standard Recommended Practice-Design Consid-
3.1.6 limitations—The user of this guide is encouraged to
erations for Corrosion Control of Reinforcing Steel in
review any available third party verification information pro-
Concrete
vided as part of the vendor selection process.
RP-0285 Standard Recommended Practice-Corrosion Con-
3.1.7 noninvasive procedure—a method of determining the
trol of Underground Storage Tank Systems by Cathodic
corrosion status of a tank from the characteristics of its
Protection
surroundings with minimal entry into the tank. Further, for the
2.5 Environmental Protection Agency Methods:
purposes of this guide, it does not require manned entry into
EPA SW 846 Test Methods for Evaluating Solid Waste
the tank. (See invasive.)
EPA 371.1 Measurement of Sulfate Reducing Bacteria
3.1.8 pH—the numerical value of the negative logarithm of
2.6 National Fire Protection Association (NFPA) Practice:
the hydrogen ion concentration in moles per litre in an
NFPA 329 Recommended Practice for Handling Under-
electrolyte.
ground Releases of Flammable and Combustible Liquids
3.1.9 redox potential—potential of platinized platinum elec-
2.7 Underwriters Laboratories Standard:
trode in a redox environment (reversible system). The value of
UL 58 Steel Underground Tanks for Flammable and Com-
redox potential depends on whether the system is in the
bustible Liquids
oxidized, partially oxidized, partially reduced, or reduced state.
3.1.10 tank tightness test—a method capable of detecting a
3. Terminology
0.1 gal/h leak rate, while accounting for any applicable effects
3.1 Definitions of Terms Specific to This Standard:
of thermal expansion or contraction of the product, of vapor
3.1.1 buried—to be placed in the ground and covered with
pockets, of tank deformation, of evaporation or condensation,
earth.
and of the location of the water table. The method must be
capable of detecting a 0.1 gal/h leak rate with a probability of
3.1.2 cathodic protection—an applied technique to prevent
further corrosion of a metal surface by making that surface the detection of at least 0.95 and a probability of false alarm of at
most 0.05 or in accordance with NFPA 329.
cathode of an electrochemical cell. For example, a tank system
can be cathodically protected through the application of either
3.1.11 unconditional probability of corrosion failure—the
galvanic anodes or impressed current.
probability of corrosion failure which includes a determination
3.1.3 corrosion specialist/cathodic protection specialist—a
of whether localized, pitting, or general corrosion is occurring.
competent person who by reason of knowledge of the physical
3.1.12 underground storage tank (UST)—any one or com-
sciences and the principles of engineering and mathematics,
bination of tanks (including connected underground piping),
acquired by education and related practical experience, is
the volume of which is 10 % or more beneath the surface of the
qualified to engage in the practice of corrosion control on
ground.
buried or submerged metallic piping systems and metallic
3.1.13 upgrade—the addition to or retrofit of UST systems
tanks. Such persons shall be registered professional engineers
using approaches including, but not limited to, cathodic pro-
or persons recognized as corrosion specialists or cathodic
tection to improve the ability of a UST system to prevent a
protection specialists by NACE, if their professional activities
release.
include suitable experiences in external corrosion control on
buried or submerged metallic piping and tanks.
3.1.14 UST—see underground storage tank (see 3.1.12).
3.1.15 vendor provided information—The user is referred to
Annex A1 for a specific form and format of information which
Available from American Society for Nondestructive Testing (ASNT), P.O. Box
must be provided by a vendor. This information consists of
28518, 1711 Arlingate Ln., Columbus, OH 43228-0518, http://www.asnt.org.
5 historic performance data on a method and is mandated as part
Available from NACE International (NACE), 15835 Park Ten Pl., Houston, TX
of the guide.
77084, http://www.nace.org.
Available from United States Environmental Protection Agency (EPA), Office
of Underground Storage Tanks, William Jefferson Clinton Bldg., 1200 Pennsylvania
4. Significance and Use
Ave., NW, Washington, DC 20460, http://www.epa.gov.
Available from National Fire Protection Association (NFPA), 1 Batterymarch
4.1 This guide provides three methods for determining the
Park, Quincy, MA 02269-9101.
8 suitability of a buried steel tank to be upgraded with cathodic
Available from Underwriters Laboratories (UL), UL Headquarters, 333 Pfing-
sten Road, Northbrook, IL, 60062, http://www.ul.com. protection.
G158 − 98 (2021)
4.2 This guide may be used to assess any UST, including 8.1.2.1 Number and capacity,
non-regulated USTs. 8.1.2.2 Location and dimensions,
8.1.2.3 Age,
4.3 This guide provides three alternative methods but does
8.1.2.4 Material of construction,
not recommend any specific method or application. The
8.1.2.5 Electrical isolation,
responsibility for selection of a method rests with the user.
8.1.2.6 Type of product stored,
4.4 This guide has specific requirements for vendor pro-
8.1.2.7 Names of site contact personnel,
vided information which should be requested and reviewed by
8.1.2.8 Backfill material,
the user.
8.1.2.9 Coatings and linings,
8.1.2.10 Leak history,
5. Permits, Plans and Tank Leak Testing
8.1.2.11 Repair history,
5.1 Prior to engaging in any activities relating to the 8.1.2.12 Site plans,
alteration, repair, or upgrade of any UST system, consult all
8.1.2.13 Installation specifications,
necessary authorities to obtain any required permits. 8.1.2.14 Tank excavation liners, and
8.1.2.15 As-built drawings.
5.2 Tank Leak Testing:
8.1.3 Information Not in the Immediate Vicinity of the
5.2.1 To establish that tanks are not leaking prior to
Tanks—The presence of the following items, that are external
assessment, they shall be assessed by a leak detection system.
to the tank area, shall be investigated and included as appro-
This leak detection assessment alone is not sufficient to
priate to the method of assessment of the suitability of tanks for
determine that a tank is suitable for upgrading with cathodic
upgrading with cathodic protection:
protection under this guide.
8.1.3.1 Stray dc current sources,
5.2.2 A tightness test or another release detection system in
8.1.3.2 Existing cathodic protection systems,
accordance with NFPA 329 shall be used. Any release detection
8.1.3.3 Steel product and vent piping and fittings, and
must be capable of detecting a leak from any portion of the
8.1.3.4 Adjacent subsurface metallic/steel-reinforced con-
tank that routinely contains product, and be independently
crete structures.
evaluated and certified in accordance with Practice E1526 or
the equivalent. Leak detection results shall be provided to the
8.2 Preliminary Evaluation—Prior to assessing the tank, a
corrosion specialist/cathodic protection specialist.
preliminary site survey must be performed pursuant to Section
5.2.3 This testing shall be accomplished within six months
8 and a tightness test must be performed pursuant to 5.2 to
prior to performing any of the assessment procedures.
establish that the tank is not leaking.
6. Required Approvals and Certifications
9. Method A—Noninvasive with Primary Emphasis on
Statistical and Electrochemical Analysis of External
6.1 The corrosion assessment work carried out under this
Site Environment Corrosion Data (1, 2)
guide shall be performed under the responsible direction of a
corrosion specialist/cathodic protection specialist as defined in
9.1 Field and Laboratory Testing—Noninvasive with Pri-
3.1.3.
mary Emphasis on Statistical and Electrochemical Analysis of
External Site Environment Corrosion Data.
6.2 The corrosion specialist/cathodic protection specialist
9.1.1 Tests shall be conducted by, or as directed by a
shall certify to the tank owner or operator that the personnel
corrosion specialist/cathodic protection specialist.
performing the assessment work on the tank are knowledgeable
9.1.2 Field Testing Procedures—Tests to be performed shall
of all the applicable procedures in this guide.
include, but are not limited to, the following:
6.3 The corrosion specialist/cathodic protection specialist
9.1.2.1 Stray Currents—Perform tests to detect the presence
shall certify to the tank owner or operator that all work was
of stray currents at each tank site. This test shall consist of
performed in strict accordance with this guide.
measuring structure-to-soil potentials at right angles at a
minimum of two locations within the tank facilities and
7. General Safety Requirements
observing the measurements for not less than 2 h at a time
7.1 All personnel shall comply with applicable federal,
when such influences are most likely to occur. The monitor
state, and local health and safety codes and regulations.
shall consist of a field data acquisition unit, with a minimum of
10 MΩ input impedance, used in conjunction with a stable
8. Preliminary Site Survey
reference cell(s) placed in contact with the soil in the vicinity
8.1 A corrosion technician, under the responsible direction of the tank. The instrument shall measure and store structure-
of the corrosion specialist/cathodic protection specialist, shall to-electrolyte potential (voltage) data at least every 5 s through-
obtain
...
This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: G158 − 98 (Reapproved 2016) G158 − 98 (Reapproved 2021)
Standard Guide for
Three Methods of Assessing Buried Steel Tanks
This standard is issued under the fixed designation G158; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
INTRODUCTION
The purpose of this guide is to provide three methods of inspecting and assessing buried steel
tank(s) for corrosion damage and determining the suitability of these tanks prior to application of
cathodic protection.
1. Scope
1.1 This guide covers procedures to be implemented prior to the application of cathodic protection for evaluating the suitability
of a tank for upgrading by cathodic protection alone.
1.2 Three procedures are described and identified as Methods A, B, and C.
1.2.1 Method A—Noninvasive with primary emphasis on statistical and electrochemical analysis of external site environment
corrosion data.
1.2.2 Method B—Invasive ultrasonic thickness testing with external corrosion evaluation.
1.2.3 Method C—Invasive permanently recorded visual inspection and evaluation including external corrosion assessment.
1.3 This guide presents the methodology and the procedures utilizing site and tank specific data for determining a tank’stank’s
condition and the suitability for such tanks to be upgraded with cathodic protection.
1.4 The tank’s condition shall be assessed using Method A, B, or C. Prior to assessing the tank, a preliminary site survey shall
be performed pursuant to Section 8 and the tank shall be tightness tested pursuant to 5.2 to establish that the tank is not leaking.
1.5 While this guide provides minimum procedures for assessing a tank’s condition, this guide does not provide minimum
installation procedures or requirements for upgrades of the tank by cathodic protection.
1.6 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical
conversions to SI units that are provided for information only and are not considered standard.
1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
This guide is under the jurisdiction of ASTM Committee G01 on Corrosion of Metals and is the direct responsibility of Subcommittee G01.10 on Corrosion in Soils.
Current edition approved May 1, 2016Aug. 1, 2021. Published May 2016August 2021. Originally approved in 1998. Last previous edition approved in 20102016 as
G158 – 98 (2010).(2016). DOI: 10.1520/G0158-98R16.10.1520/G0158-98R21.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
G158 − 98 (2021)
1.8 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 The most recent version of the following documents should be consulted as references by those using this guide:
2.2 ASTM Standards:
D2216 Test Methods for Laboratory Determination of Water (Moisture) Content of Soil and Rock by Mass
E114 Practice for Ultrasonic Pulse-Echo Straight-Beam Contact Testing
E797E797/E797M Practice for Measuring Thickness by Manual Ultrasonic Pulse-Echo Contact Method
E1323 Guide for Evaluating Laboratory Measurement Practices and the Statistical Analysis of the Resulting Data
E1526 Practice for Evaluating the Performance of Release Detection Systems for Underground Storage Tank Systems
(Withdrawn 2002)
G51 Test Method for Measuring pH of Soil for Use in Corrosion Testing
G57 Test Method for Measurement of Soil Resistivity Using the Wenner Four-Electrode Method
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’sstandard’s Document Summary page on the ASTM website.
The last approved version of this historical standard is referenced on www.astm.org.
G158 − 98 (2021)
2.3 ASNT Standard:
ASNT SNT-TC-1A Personnel Qualification and Certification in Nondestructive Testing
2.4 NACE International Standards:
RP-0169 Standard Recommended Practice-Control on External Corrosion on Underground or Submerged Metallic Piping
Systems
RP-0187 Standard Recommended Practice-Design Considerations for Corrosion Control of Reinforcing Steel in Concrete
RP-0285 Standard Recommended Practice-Corrosion Control of Underground Storage Tank Systems by Cathodic Protection
2.5 Environmental Protection Agency Methods:
EPA SW 846 Test Methods for Evaluating Solid Waste
EPA 371.1 Measurement of Sulfate Reducing Bacteria
2.6 National Fire Protection Association (NFPA) Practice:
NFPA 329 Recommended Practice for Handling Underground Releases of Flammable and Combustible Liquids
2.7 Underwriters Laboratories Inc.Standard:
UL 58 Steel Underground Tanks for Flammable and Combustible Liquids
3. Terminology
3.1 Definitions of Terms Specific to This Standard:
3.1.1 buried—to be placed in the ground and covered with earth.
3.1.2 cathodic protection—an applied technique to prevent further corrosion of a metal surface by making that surface the cathode
of an electrochemical cell. For example, a tank system can be cathodically protected through the application of either galvanic
anodes or impressed current.
3.1.3 corrosion specialist/cathodic protection specialist—a competent person who by reason of knowledge of the physical
sciences and the principles of engineering and mathematics, acquired by education and related practical experience, is qualified
to engage in the practice of corrosion control on buried or submerged metallic piping systems and metallic tanks. Such persons
shall be registered professional engineers or persons recognized as corrosion specialists or cathodic protection specialists by
NACE, if their professional activities include suitable experiences in external corrosion control on buried or submerged metallic
piping and tanks.
3.1.4 corrosion technician—a person possessing basic knowledge of corrosion and corrosion control, who is capable of
performing routine, well defined work under the supervision of the corrosion specialist/cathodic protection specialist.
3.1.5 invasive procedure—a method of determining the corrosion status of a tank by assessing the tank from the inside as part of
the upgrade procedure. Further, for the purposes of this guide, it does not require manned entry into the tank. (See non-invasive.)
3.1.6 limitations—The user of this guide is encouraged to review any available third party verification information provided as part
of the vendor selection process.
3.1.7 noninvasive procedure—a method of determining the corrosion status of a tank from the characteristics of its surroundings
with minimal entry into the tank. Further, for the purposes of this guide, it does not require manned entry into the tank. (See
invasive.)
3.1.8 pH—the numerical value of the negative logarithm of the hydrogen ion concentration in moles per litre in an electrolyte.
3.1.9 redox potential—potential of platinized platinum electrode in a redox environment (reversible system). The value of redox
potential depends on whether the system is in the oxidized, partially oxidized, partially reduced, or reduced state.
Available from The American Society for Nondestructive Testing (ASNT), P.O. Box 28518, 1711 Arlingate Ln., Columbus, OH 43228-0518.43228-0518,
http://www.asnt.org.
Available from National Association of Corrosion Engineers (NACE), 1440 South Creek Dr., Houston, TX 77084-4906.NACE International (NACE), 15835 Park Ten
Pl., Houston, TX 77084, http://www.nace.org.
Available from US United States Environmental Protection Agency, Agency (EPA), Office of Underground Storage Tanks, 401 “M” St. SW, Washington, DC
20460.William Jefferson Clinton Bldg., 1200 Pennsylvania Ave., NW, Washington, DC 20460, http://www.epa.gov.
Available from Underwriters Laboratories (UL), Corporate Progress, 333 Pfingsten Rd., Northbrook, IL 60062.
Available from National Fire Protection Association (NFPA), 1 Batterymarch Park, Quincy, MA 02269-9101.
Available from Underwriters Laboratories (UL), UL Headquarters, 333 Pfingsten Road, Northbrook, IL, 60062, http://www.ul.com.
G158 − 98 (2021)
3.1.10 tank tightness test—a method capable of detecting a 0.1 gal/h leak rate, while accounting for any applicable effects of
thermal expansion or contraction of the product, of vapor pockets, of tank deformation, of evaporation or condensation, and of the
location of the water table. The method must be capable of detecting a 0.1 gal/h leak rate with a probability of detection of at least
0.95 and a probability of false alarm of at most 0.05 or in accordance with NFPA 329.
3.1.11 unconditional probability of corrosion failure—the probability of corrosion failure which includes a determination of
whether localized, pitting, or general corrosion is occurring.
3.1.12 underground storage tank (UST)—any one or combination of tanks (including connected underground piping), the volume
of which is 10 % or more beneath the surface of the ground.
3.1.13 upgrade—the addition to or retrofit of UST systems using approaches including, but not limited to, cathodic protection to
improve the ability of a UST system to prevent a release.
3.1.14 UST—see underground storage tank (see 3.1.12).
3.1.15 vendor provided information—The user is referred to Annex A1 for a specific form and format of information which must
be provided by a vendor. This information consists of historic performance data on a method and is mandated as part of the guide.
4. Significance and Use
4.1 This guide provides three methods for determining the suitability of a buried steel tank to be upgraded with cathodic
protection.
4.2 This guide may be used to assess any UST, including non-regulated USTs.
4.3 This guide provides three alternative methods but does not recommend any specific method or application. The responsibility
for selection of a method rests with the user.
4.4 This guide has specific requirements for vendor provided information which should be requested and reviewed by the user.
5. Permits, Plans and Tank Leak Testing
5.1 Prior to engaging in any activities relating to the alteration, repair, or upgrade of any UST system, consult all necessary
authorities to obtain any required permits.
5.2 Tank Leak Testing:
5.2.1 To establish that tanks are not leaking prior to assessment, they shall be assessed by a leak detection system. This leak
detection assessment alone is not sufficient to determine that a tank is suitable for upgrading with cathodic protection under this
guide.
5.2.2 A tightness test or another release detection system in accordance with NFPA 329 shall be used. Any release detection must
be capable of detecting a leak from any portion of the tank that routinely contains product, and be independently evaluated and
certified in accordance with Practice E1526 or the equivalent. Leak detection results shall be provided to the corrosion
specialist/cathodic protection specialist.
5.2.3 This testing shall be accomplished within six months prior to performing any of the assessment procedures.
6. Required Approvals and Certifications
6.1 The corrosion assessment work carried out under this guide shall be performed under the responsible direction of a corrosion
specialist/cathodic protection specialist as defined in 3.1.3.
G158 − 98 (2021)
6.2 The corrosion specialist/cathodic protection specialist shall certify to the tank owner or operator that the personnel performing
the assessment work on the tank are knowledgeable of all the applicable procedures in this guide.
6.3 The corrosion specialist/cathodic protection specialist shall certify to the tank owner or operator that all work was performed
in strict accordance with this guide.
7. General Safety Requirements
7.1 All personnel shall comply with applicable federal, state, and local health and safety codes and regulations.
8. Preliminary Site Survey
8.1 A corrosion technician, under the responsible direction of the corrosion specialist/cathodic protection specialist, shall obtain
tank site specific information as appropriate to the method of assessment to be used.
8.1.1 Facility Information:
8.1.1.1 Address or location, and
8.1.1.2 Name and telephone number of owner and operator contact personnel.
8.1.2 Tank and Piping Details:
8.1.2.1 Number and capacity,
8.1.2.2 Location and dimensions,
8.1.2.3 Age,
8.1.2.4 Material of construction,
8.1.2.5 Electrical isolation,
8.1.2.6 Type of product stored,
8.1.2.7 Names of site contact personnel,
8.1.2.8 Backfill material,
8.1.2.9 Coatings and linings,
8.1.2.10 Leak history,
8.1.2.11 Repair history,
8.1.2.12 Site plans,
8.1.2.13 Installation specifications,
8.1.2.14 Tank excavation liners, and
8.1.2.15 As-built drawings.
8.1.3 Information Not in the Immediate Vicinity of the Tanks—The presence of the following items, that are external to the tank
area, shall be investigated and included as appropriate to the method of assessment of the suitability of tanks for upgrading with
cathodic protection:
G158 − 98 (2021)
8.1.3.1 Stray dc current sources,
8.1.3.2 Existing cathodic protection systems,
8.1.3.3 Steel product and vent piping and fittings, and
8.1.3.4 Adjacent subsurface metallic/steel-reinforced concrete structures.
8.2 Preliminary Evaluation—Prior to assessing the tank, a preliminary site survey must be performed pursuant to Section 8 and
a tightness test must be performed pursuant to 5.2 to establish that the tank is not leaking.
9. Method A—Noninvasive with Primary Emphasis on Statistical and Electrochemical Analysis of External Site
Environment C
...
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