ASTM G158-98(2010)
(Guide)Standard Guide for Three Methods of Assessing Buried Steel Tanks
Standard Guide for Three Methods of Assessing Buried Steel Tanks
SIGNIFICANCE AND USE
This guide provides three methods for determining the suitability of a buried steel tank to be upgraded with cathodic protection.
This guide may be used to assess any UST, including non-regulated USTs.
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.
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 and health practices and determine the applicability of regulatory limitations prior to use.
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Designation: G158 − 98(Reapproved 2010)
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 1.6 The values stated in inch-pound units are to be regarded
as standard. The values given in parentheses are mathematical
1.1 Thisguidecoversprocedurestobeimplementedpriorto
conversions to SI units that are provided for information only
the application of cathodic protection for evaluating the suit-
and are not considered standard.
ability of a tank for upgrading by cathodic protection alone.
1.7 This standard does not purport to address all of the
1.2 Three procedures are described and identified as Meth-
safety concerns, if any, associated with its use. It is the
ods A, B, and C.
responsibility of the user of this standard to establish appro-
1.2.1 Method A—Noninvasive with primary emphasis on
priate safety and health practices and determine the applica-
statistical and electrochemical analysis of external site envi-
bility of regulatory limitations prior to use.
ronment corrosion data.
1.2.2 Method B—Invasive ultrasonic thickness testing with
2. Referenced Documents
external corrosion evaluation.
2.1 The most recent version of the following documents
1.2.3 Method C—Invasive permanently recorded visual in-
should be consulted as references by those using this guide:
spection and evaluation including external corrosion assess-
2.2 ASTM Standards:
ment.
D2216 Test Methods for Laboratory Determination of Water
1.3 This guide presents the methodology and the procedures
(Moisture) Content of Soil and Rock by Mass
utilizing site and tank specific data for determining a tank’s
E114 Practice for Ultrasonic Pulse-Echo Straight-Beam
condition and the suitability for such tanks to be upgraded with
Contact Testing
cathodic protection.
E797 Practice for Measuring Thickness by Manual Ultra-
1.4 The tank’s condition shall be assessed using MethodA,
sonic Pulse-Echo Contact Method
B, or C. Prior to assessing the tank, a preliminary site survey
E1323 Guide for Evaluating Laboratory Measurement Prac-
shall be performed pursuant to Section 8 and the tank shall be
tices and the Statistical Analysis of the Resulting Data
tightness tested pursuant to 5.2 to establish that the tank is not
E1526 Practice for Evaluating the Performance of Release
leaking.
Detection Systems for Underground Storage Tank Sys-
tems (Withdrawn 2002)
1.5 While this guide provides minimum procedures for
G51 Test Method for Measuring pH of Soil for Use in
assessing a tank’s condition, this guide does not provide
Corrosion Testing
minimum installation procedures or requirements for upgrades
G57 Test Method for Field Measurement of Soil Resistivity
of the tank by cathodic protection.
Using the Wenner Four-Electrode Method
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 Feb. 1, 2010. Published February 2010. Originally the ASTM website.
approved in 1998. Last previous edition approved in 2004 as G158–98(2004). DOI:
The last approved version of this historical standard is referenced on
10.1520/G0158-98R10.
www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
G158 − 98 (2010)
2.3 ASNT Standard: 3.1.5 invasive procedure—a method of determining the
ASNT SNT-TC-1A Personnel Qualification and Certifica- corrosion status of a tank by assessing the tank from the inside
tion in Nondestructive Testing as part of the upgrade procedure. Further, for the purposes of
this guide, it does not require manned entry into the tank. (See
2.4 NACE International Standards:
non-invasive.)
RP-0169 Standard Recommended Practice-Control on Ex-
ternal Corrosion on Underground or Submerged Metallic
3.1.6 limitations—The user of this guide is encouraged to
Piping Systems
review any available third party verification information pro-
RP-0187 Standard Recommended Practice-Design Consid-
vided as part of the vendor selection process.
erations for Corrosion Control of Reinforcing Steel in
3.1.7 noninvasive procedure—a method of determining the
Concrete
corrosion status of a tank from the characteristics of its
RP-0285 Standard Recommended Practice-Corrosion Con-
surroundings with minimal entry into the tank. Further, for the
trol of Underground Storage Tank Systems by Cathodic
purposes of this guide, it does not require manned entry into
Protection
the tank. (See invasive.)
2.5 Environmental Protection Agency Methods:
3.1.8 pH—the numerical value of the negative logarithm of
EPA SW 846 Test Methods for Evaluating Solid Waste
the hydrogen ion concentration in moles per litre in an
EPA 371.1 Measurement of Sulfate Reducing Bacteria
electrolyte.
2.6 National Fire Protection Association (NFPA)
3.1.9 redox potential—potential of platinized platinum elec-
NFPA 329 Recommended Practice for Handling Under-
trode in a redox environment (reversible system). The value of
ground Releases of Flammable and Combustible Liquids
redox potential depends on whether the system is in the
2.7 Underwriters Laboratories Inc.
oxidized, partially oxidized, partially reduced, or reduced state.
UL 58 Steel Underground Tanks for Flammable and Com-
3.1.10 tank tightness test—a method capable of detecting a
bustible Liquids
0.1 gal/h leak rate, while accounting for any applicable effects
of thermal expansion or contraction of the product, of vapor
3. Terminology
pockets, of tank deformation, of evaporation or condensation,
3.1 Definitions of Terms Specific to This Standard:
and of the location of the water table. The method must be
3.1.1 buried—to be placed in the ground and covered with
capable of detecting a 0.1 gal/h leak rate with a probability of
earth.
detection of at least 0.95 and a probability of false alarm of at
3.1.2 cathodic protection—an applied technique to prevent
most 0.05 or in accordance with NFPA 329.
further corrosion of a metal surface by making that surface the
3.1.11 unconditional probability of corrosion failure—the
cathode of an electrochemical cell. For example, a tank system
probability of corrosion failure which includes a determination
can be cathodically protected through the application of either
of whether localized, pitting, or general corrosion is occurring.
galvanic anodes or impressed current.
3.1.12 underground storage tank (UST)—any one or com-
3.1.3 corrosion specialist/cathodic protection specialist—a
bination of tanks (including connected underground piping),
competent person who by reason of knowledge of the physical
thevolumeofwhichis10 %ormorebeneaththesurfaceofthe
sciences and the principles of engineering and mathematics,
ground.
acquired by education and related practical experience, is
3.1.13 upgrade—the addition to or retrofit of UST systems
qualified to engage in the practice of corrosion control on
using approaches including, but not limited to, cathodic pro-
buried or submerged metallic piping systems and metallic
tection to improve the ability of a UST system to prevent a
tanks. Such persons shall be registered professional engineers
release.
or persons recognized as corrosion specialists or cathodic
3.1.14 UST—see underground storage tank (see 3.1.12).
protection specialists by NACE, if their professional activities
include suitable experiences in external corrosion control on
3.1.15 vendor provided information—The user is referred to
buried or submerged metallic piping and tanks.
AnnexA1 for a specific form and format of information which
must be provided by a vendor. This information consists of
3.1.4 corrosion technician—a person possessing basic
historic performance data on a method and is mandated as part
knowledge of corrosion and corrosion control, who is capable
of the guide.
of performing routine, well defined work under the supervision
of the corrosion specialist/cathodic protection specialist.
4. Significance and Use
4.1 This guide provides three methods for determining the
Available fromTheAmerican Society for NondestructiveTesting (ASNT), P.O.
suitability of a buried steel tank to be upgraded with cathodic
Box 28518, 1711 Arlingate Ln., Columbus, OH 43228-0518.
protection.
Available from National Association of Corrosion Engineers (NACE), 1440
South Creek Dr., Houston, TX 77084-4906.
4.2 This guide may be used to assess any UST, including
Available from US Environmental Protection Agency, Office of Underground
non-regulated USTs.
Storage Tanks, 401 “M” St. SW, Washington, DC 20460.
Available from Underwriters Laboratories (UL), Corporate Progress, 333
4.3 This guide provides three alternative methods but does
Pfingsten Rd., Northbrook, IL 60062.
not recommend any specific method or application. The
Available from National Fire Protection Association (NFPA), 1 Batterymarch
Park, Quincy, MA 02269-9101. responsibility for selection of a method rests with the user.
G158 − 98 (2010)
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
5.2 Tank Leak Testing:
8.1.2.15 As-built drawings.
5.2.1 To establish that tanks are not leaking prior to
8.1.3 Information Not in the Immediate Vicinity of the
assessment, they shall be assessed by a leak detection system.
Tanks—The presence of the following items, that are external
This leak detection assessment alone is not sufficient to
to the tank area, shall be investigated and included as appro-
determine that a tank is suitable for upgrading with cathodic
priatetothemethodofassessmentofthesuitabilityoftanksfor
protection under this guide.
upgrading with cathodic protection:
5.2.2 Atightness test or another release detection system in
8.1.3.1 Stray dc current sources,
accordancewithNFPA329shallbeused.Anyreleasedetection
8.1.3.2 Existing cathodic protection systems,
must be capable of detecting a leak from any portion of the
8.1.3.3 Steel product and vent piping and fittings, and
tank that routinely contains product, and be independently
8.1.3.4 Adjacent subsurface metallic/steel-reinforced con-
evaluated and certified in accordance with Practice E1526 or
crete structures.
the equivalent. Leak detection results shall be provided to the
corrosion specialist/cathodic protection specialist.
8.2 Preliminary Evaluation—Prior to assessing the tank, a
5.2.3 This testing shall be accomplished within six months
preliminary site survey must be performed pursuant to Section
prior to performing any of the assessment procedures.
8 and a tightness test must be performed pursuant to 5.2 to
establish that the tank is not leaking.
6. Required Approvals and Certifications
6.1 The corrosion assessment work carried out under this
9. Method A—Noninvasive with Primary Emphasis on
guide shall be performed under the responsible direction of a
Statistical and Electrochemical Analysis of External
corrosion specialist/cathodic protection specialist as defined in
Site Environment Corrosion Data (1, 2)
3.1.3.
9.1 Field and Laboratory Testing—Noninvasive with Pri-
6.2 The corrosion specialist/cathodic protection specialist
mary Emphasis on Statistical and Electrochemical Analysis of
shall certify to the tank owner or operator that the personnel
External Site Environment Corrosion Data.
performingtheassessmentworkonthetankareknowledgeable
9.1.1 Tests shall be conducted by, or as directed by a
of all the applicable procedures in this guide.
corrosion specialist/cathodic protection specialist.
6.3 The corrosion specialist/cathodic protection specialist
9.1.2 Field Testing Procedures—Tests to be performed shall
shall certify to the tank owner or operator that all work was
include, but are not limited to, the following:
performed in strict accordance with this guide.
9.1.2.1 Stray Currents—Perform tests to detect the presence
of stray currents at each tank site. This test shall consist of
7. General Safety Requirements
measuring structure-to-soil potentials at right angles at a
7.1 All personnel shall comply with applicable federal,
minimum of two locations within the tank facilities and
state, and local health and safety codes and regulations.
observing the measurements for not less than2hata time
when such influences are most likely to occur. The monitor
8. Preliminary Site Survey
shall consist of a field data acquisition unit, with a minimum of
10-MΩ input impedance, used in conjunction with a stable
8.1 A corrosion technician, under the responsible direction
reference cell(s) placed in contact with the soil in the vicinity
of the corrosion specialist/cathodic protection specialist, shall
of the tank. The instrument shall measure and store structure-
obtain tank site specific information as appropriate to the
to-electrolytepotential(voltage)dataatleastevery5sthrough-
method of assessment to be used.
out the entire duration of field investigation at the site or for 2
8.1.1 Facility Information:
h, whichever is greater. If variations of 650 mV or greater are
8.1.1.1 Address or location, and
measuredduringthetestperiod,make24-hrecordingmeasure-
8.1.1.2 Name and telephone number of owner and operator
ments to confirm stray current effects.
contact personnel.
8.1.2 Tank and Piping Details: 9.1.2.2 Tank Information:
8.1.2.1 Number and capacity, (a) Locate all tanks and confirm materials of construction,
8.1.2.2 Location and dimensions, age, capacity, and dimensions. Produce detailed site sketches
8.1.2.3 Age, describing the layout of the UST
...
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