SECTION 334.49. Corrosion Protection

(a) General requirements.

(1) Owners and operators of underground storage tank (UST) systems (or underground metal UST system components) which are required to be protected from corrosion shall comply with the requirements in this section to ensure that releases due to corrosion are prevented.

(2) All corrosion protection systems shall be designed, installed, operated, and maintained in a manner that will ensure that corrosion protection will be continuously provided to all underground metal components of the UST system.

(3) Any alternative methods for corrosion protection or variances from the requirements of this section are prohibited, except when reviewed and approved by the agency pursuant to procedures for variances found in §334.43 of this title (relating to Variances and Alternative Procedures).

(4) Corrosion protection in accordance with the provisions of this section shall be provided to all underground and/or totally or partially submerged metal components of any existing or new UST system which are designed or used to convey, contain, or store regulated substances, including, but not limited to, the tanks, piping (including valves, fittings, flexible connectors, swing joints, and impact/shear valves), and also to other underground metal components associated with a UST system, including but not limited to, secondary containment devices, manways, manholes, fill pipes, vent lines, submersible pump housings, spill containers, and riser pipes.

(5) For internal corrosion protection, the interior bottom surface of new metal tanks installed on or after September 29, 1989, shall be fitted with a striker plate under all fill, gauge, and monitoring openings.

(6) When provisions of this subsection require compliance with a specific code or standard of practice developed by a nationally recognized association or independent testing laboratory, the most recent version of the referenced code in effect at the time of the regulated UST activity shall be applicable.

(7) For a UST system to be placed temporarily out of service, the owner or operator must comply with the requirements of §334.54(c) of this title (relating to Temporary Removal from Service).

(b) Allowable corrosion protection methods. All components of a UST system which are designed to convey, contain, or store regulated substances shall be protected from corrosion by one or more of the following methods.

(1) The component may be constructed of a noncorrodible material which is compatible with the stored regulated substance(s).

(2) The component may be electrically isolated from the corrosive elements of the surrounding soil, backfill, groundwater or any other water, and from other metallic components by installing the component in an open area (e.g., manway, sump, vault, pit, etc.) where periodic visual inspection of all parts of the component for the presence of corrosion or released substances is practicable.

(3) The component may be electrically isolated from the corrosive elements of the surrounding soil, backfill, groundwater or any other water, and from other metallic components by completely enclosing the component in a secondary containment device (e.g., wall, jacket, or liner), provided that:

(A) the secondary containment device is designed and installed in accordance with the applicable technical and installation standards in §334.45(d) of this title (relating to Technical Standards for New Underground Storage Tank Systems) and §334.46(f) of this title (relating to Installation Standards for New Underground Storage Tank Systems), and in accordance with an applicable code or standard of practice developed by a nationally recognized association or independent testing laboratory, and is either:

(i) constructed of a noncorrodible material which is compatible with the stored regulated substance;

(ii) electrically isolated from the protected component and other metallic components; or

(iii) cathodically protected by either a factory-installed or field-installed cathodic protection system meeting the applicable requirements of subsection (c) of this section; and

(B) the interstitial space between the protected component and the secondary containment device shall be free of any soil, backfill material, groundwater or any other water, or other substances, and the protected component shall be regularly inspected and tested for electrical isolation in accordance with the provisions in subsection (d)(1) of this section.

(4) Tanks (only) may be factory-constructed either as a steel/fiberglass-reinforced plastic composite tank, or as a steel tank with a bonded fiberglass-reinforced plastic external cladding or laminate, or as a steel tank with a bonded fiberglass reinforced polyurethane coating, as a steel tank with a bonded polyurethane external coating, or as a steel tank completely contained within a nonmetallic external tank jacket in accordance with the requirements in §334.45(b)(1)(D), (E), or (F) of this title, as applicable.

(5) The component may be coated with a suitable dielectric material, equipped with appropriate dielectric fittings for electrical isolation, and equipped with either:

(A) a factory-installed cathodic protection system meeting the requirements of subsection (c)(1) of this section; or

(B) a field-installed cathodic protection system meeting the requirements of subsection (c)(2) of this section.

(6) Except for the tanks and the piping system components, other underground components of a UST system (including vent lines, fill risers, spill containment vessels, and tank fittings (e.g., bunghole plugs)) which do not routinely contain regulated substances may be protected from corrosion by thorough coating or wrapping with a suitable dielectric material which is compatible with the stored regulated substance without the need for the use of other corrosion protection methods.

(7) Corrosion protection in accordance with the requirements of this subchapter is not required if it is determined by a corrosion specialist that corrosion protection of an underground metal UST system or UST system component is unnecessary because the site is not corrosive enough to cause a release due to corrosion for the operational life of the UST system. The upgrade or repair of an existing corrosion protection system for an underground metal UST system or UST system component is not required if it is determined by a corrosion specialist that said upgrading or repair is unnecessary and that the protection provided by the existing corrosion protection system is sufficient to prevent a release due to corrosion for the operational life of the UST system. In either case, the determination of the corrosion specialist must be made in writing, must be signed by the corrosion specialist (corrosion specialist must also seal the written determination if he or she is a qualified duly licensed professional engineer in Texas), and must be maintained by the owner and operator as part of the records for the facility in keeping with the requirements of subsection (e) of this section and §334.10(b) of this title (relating to Reporting and Recordkeeping).

(c) Cathodic protection systems.

(1) Factory-installed cathodic protection systems.

(A) A factory-installed cathodic protection system on any UST component shall be designed, fabricated, installed, operated, and maintained in accordance with applicable codes or standards of practice developed for such cathodic protection method by a nationally recognized association or independent testing laboratory.

(B) At a minimum, the factory-installed cathodic protection system shall include the following components:

(i) a suitable dielectric external coating or laminate, which shall thoroughly cover all exterior surfaces exposed to the soil, backfill, or groundwater or any other water, and which shall consist of materials which are compatible with the stored regulated substances;

(ii) dielectric isolation bushings, connections, or fittings, which shall be installed at all locations where the protected component connects to other metallic system components, and which shall be constructed of materials which are compatible with the stored regulated substances; and

(iii) sacrificial anodes which are firmly attached and electrically connected to the protected components and which are positioned and sized to provide complete cathodic protection for all parts of the protected component.

(2) Field-installed cathodic protection systems.

(A) A field-installed cathodic protection system on any UST system component shall be designed by a qualified corrosion specialist, and shall be designed, installed, operated, and maintained in accordance with applicable codes or standards of practice developed for such cathodic protection systems by a nationally recognized association or independent testing laboratory.

(B) Impressed current cathodic protection systems shall be designed and equipped with appropriate equipment or devices capable of indicating the operational status of the system at all times.

(C) In addition to the standard inspection and testing requirements for all cathodic protection systems required in paragraph (4) of this subsection, all impressed current cathodic protection systems shall be regularly inspected by the owner or operator (or the owner's designated representative) to ensure that the rectifier and other system components are operating properly. Such inspections shall be performed at least once every 60 days.

(3) Test stations and connections. To allow for the periodic testing required in paragraph (4) of this subsection, any factory-installed or field-installed cathodic protection system shall include appropriate connections, insulated lead wires, and accessible test stations. All lead wires connected to the tanks, anodes, reference electrodes, and other components associated with the cathodic protection system shall terminate at one or more test stations. The termination of each lead wire at a test station shall be clearly labeled or coded to properly identify the specific component to which it is connected.

(4) Inspection and testing requirements for all cathodic protection systems.

(A) Except as provided in subsection (d)(2) of this section, all cathodic protection systems which are used to provide corrosion protection for any component of a UST system shall be inspected and tested to determine the adequacy of the cathodic protection by a qualified corrosion specialist or corrosion technician in accordance with the requirements in this paragraph.

(B) The inspection and testing criteria used to determine the adequacy of the cathodic protection shall be in accordance with a code or standard of practice developed by a nationally recognized corrosion association or independent testing laboratory, such as:

(i) NACE International Test Method TM0101, "Measurement Techniques Related to Criteria for Cathodic Protection of Underground Storage Tank Systems or Submerged Metallic Tank Systems;"

(ii) NACE International Test Method TM0497, "Measurement Techniques Related to Criteria for Cathodic Protection on Underground or Submerged Metallic Piping Systems;"

(iii) Steel Tank Institute Recommended Practice R051, "Cathodic Protection Testing Procedures for sti-P3 USTs;"

(iv) NACE International Standard Practice SP0285, "Corrosion Control of Underground Storage Tank Systems by Cathodic Protection;" or

(v) NACE International Standard Practice SP0169, "Control of External Corrosion on Underground or Submerged Metallic Piping Systems."

(C) All cathodic protection systems shall be inspected and tested for operability and adequacy of protection within three to six months after installation and at a subsequent frequency of at least once every three years.

(d) Requirements for other corrosion protection methods.

(1) Electrically isolated components.

(A) Except for jacketed tanks meeting the requirements of §334.45(b)(1)(F) of this title, any metal component of a UST system which is protected from corrosion by one of the electrical isolation methods described in subsection (b)(2) and (3) of this section, and which is not equipped with a cathodic protection system, shall be periodically inspected and tested to ensure that the metal component remains electrically isolated from the surrounding soil, backfill, groundwater or any other water, and from other metal components in accordance with one or more of the following procedures.

(i) When visual inspection is possible, the entire exterior surface of such component may be thoroughly inspected visually by qualified personnel for the presence of corrosion or released regulated substances.

(ii) If visual inspection is not possible, the component may be inspected and tested by a qualified corrosion technician or by a qualified corrosion specialist by taking structure to soil voltage readings in accordance with procedures established by a code or standard of practice developed by a nationally recognized association or independent testing laboratory.

(iii) The component may be inspected and/or tested by an alternative method which has been reviewed and determined by the agency to ascertain electrical isolation and to prevent the release or threatened release of any stored regulated substance in a manner that is no less protective of human health and safety and the environment than the methods described in clauses (i) and (ii) of this subparagraph, in accordance with the procedures in §334.43 of this title.

(B) The inspections and tests required in subparagraph (A) of this paragraph shall be conducted within three to six months after installation of the metal component, and then once every three years thereafter for the remaining operational life of the UST system.

(C) If the tests required in subparagraph (A) of this paragraph indicate that the metal component is no longer electrically isolated from the surrounding soil, backfill, groundwater or any other water, or from other metal components, a qualified corrosion specialist shall review the test results and thoroughly inspect the area of the metal component to ascertain the extent of electrical isolation and corrosion protection for the component.

(D) If the qualified corrosion specialist determines that the metal component is no longer adequately protected from corrosion, the owner or operator shall assure that one or more of the following procedures are completed within 60 days of the date of such determination:

(i) appropriate repairs or modifications shall be made to restore the electrical isolation of the protected component; or

(ii) a field-installed cathodic protection system meeting the requirements of subsection (c)(2) of this section shall be installed.

(2) Dual-protected tanks. If a steel/fiberglass-reinforced plastic composite tank, a steel tank with a bonded fiberglass-reinforced plastic external cladding or laminate, a steel tank with a bonded fiberglass reinforced polyurethane coating, or a steel tank with a bonded polyurethane coating is also equipped with a factory-installed cathodic protection system, then the normal inspection and testing requirements for cathodic protection systems in subsection (c)(4) of this section may be waived. This paragraph shall be applicable only to tanks meeting the design and construction requirements in §334.45(b)(1)(D) or (E) of this title, as applicable, and when such tanks are fitted with factory-installed cathodic protection systems meeting the requirements of subsection (c)(1) of this section.

(e) Corrosion protection records.

(1) Owners and operators shall maintain all corrosion protection records required in this subsection in accordance with the requirements in §334.10(b) of this title.

(2) Owners and operators shall maintain records adequate to demonstrate compliance with the corrosion protection requirements in this section, and in accordance with the following minimum requirements.

(A) All appropriate installation records related to the corrosion protection system, as listed in §334.46(i) of this title, shall be maintained for as long as the corrosion protection system is used, including:

(i) the name, address, telephone number, and corrosion protection credentials of either the company which designed the factory-installed cathodic protection system or the corrosion specialist who designed the field-installed cathodic protection system, as applicable;

(ii) drawings or plans depicting the locations of all cathodic protection system components, including the locations of all test stations; and

(iii) operating instructions and warranty information, maintenance schedules, and testing procedures for all operational components of the cathodic protection systems.

(B) The following corrosion protection records shall be maintained for at least five years after the applicable test or inspection is conducted:

(i) results of all tests and inspections of any impressed current cathodic protection system conducted in accordance with subsection (c)(2)(C) of this section; and

(ii) results of all tests and inspections of the adequacy of any cathodic protection system conducted in accordance with subsection (c)(4) of this section; and

(iii) results of all tests and inspections to assure corrosion protection for electrically isolated components in accordance with subsection (d)(1) of this section.

Source Note: The provisions of this §334.49 adopted to be effective September 29, 1989, 14 TexReg 4714; amended to be effective January 2, 1995, 19 TexReg 10104; amended to be effective November 23, 2000, 25 TexReg 11442; amended to be effective October 30, 2008, 33 TexReg 8790; amended to be effective March 17, 2011, 36 TexReg 1675; amended to be effective May 31, 2018, 43 TexReg 3390