Current through Register Vol. XLI, No. 37, September 13, 2024
Section 47-63-9 - Corrosion and Deterioration Prevention9.1 General corrosion requirements. - The owner or operator shall ensure that all regulated ASTs are maintained with those corrosion prevention measures that are necessary to prevent releases. 9.1.a. The owner or operator shall ensure that regulated AST systems are maintained with corrosion and deterioration prevention measures until the AST system has undergone permanent closure.9.1.b. Acceptable corrosion and deterioration protection methods may include any one or a combination of various methods, such as cathodic protection systems (galvanic or impressed current), external and internal coatings, internal tank liners, storage in a manner that prevents metal contact with an electrolyte, construction out of noncorrodible material or metal construction with a noncorrodible material coating.9.2 Cathodic Protection Systems.-To the extent that a cathodic protection system is used as corrosion prevention, the owner or operator shall ensure that cathodic protection systems are designed by a National Association of Corrosion Engineers (NACE) certified (or equivalent) corrosion expert and maintained to provide protection against external corrosion for the operational life of the regulated tank system (tank, tank bottoms, piping) or have provisions to allow for the periodic rehabilitation of the cathodic protection system as needed to affect repairs of failing or defective systems.9.2.a. For new, reconstructed or relocated regulated tanks, the owner or operator shall ensure that special consideration for monitoring the cathodic protection status of the underside of the AST bottom shall be provided for in the cathodic protection system designed by the corrosion expert.9.2.b. Regulated metallic AST systems with tank bottoms in direct contact with soil or other electrolytes shall be protected from corrosion, unless the tank is installed at a site that is determined by a NACE certified or equivalent corrosion expert not to be corrosive enough to cause it to have a release due to corrosion during its operating life.9.2.c. The cathodic protection system for the external bottom of a new or existing regulated metallic AST must be designed, installed, inspected, and maintained to meet or exceed the requirements for cathodic protection required by NACE Standards RP01-93, RP0169 or API 651.9.2.d. Each cathodic protection system shall have an access point that enables the owner or operator to check on the adequacy of cathodic protection. The cathodic protection systems shall be monitored in accordance with subsection 9.3 of this Rule.9.2.e. After installation of a sacrificial anode system, measurements of AST-to-soil potential must be made no sooner than 60 days and no later than 180 days after installation of the cathodic protection system by a person who, at a minimum, is NACE certified as a cathodic protection tester. If inadequate cathodic protection is indicated, the cause shall be determined, and the owner or operator shall ensure that necessary repairs are made within 90 days or another time period approved by the Secretary upon request of the owner or operator and for good cause shown.9.2.f. AST and piping connections of two dissimilar metals which create a galvanic cell are prohibited.9.2.g. For existing regulated AST systems certified as Fit for Service but having cathodic protection deficiencies, the cathodic protection system shall be upgraded to meet the minimum requirements of this Rule and industry standards on the schedule provided by the certifying person, but in no case later than the following:9.2.g.1. For Level 1 ASTs, the AST system component not meeting cathodic protection standards must be upgraded or repaired and tested by June 30, 2017.9.2.g.2. For Level 2 ASTs, the AST system component not meeting cathodic protection standards must be upgraded or repaired and tested by December 31, 2017.9.2.g.3. An existing regulated tank system that is taken out of service for internal inspection or major modification of the tank or that has been temporarily out of service and being returned to service shall have the cathodic protection upgraded or repaired and tested prior to placing the AST back into service.9.3 Operation and Maintenance of Cathodic Protection Systems. - The owner or operator of a regulated AST system with cathodic protection shall ensure compliance with the following requirements to ensure that releases due to corrosion are prevented for as long as the AST system is used to store fluids.9.3.a. All cathodic protection systems must be operated and maintained to continuously provide corrosion protection to the metal components of that portion of the regulated tank and piping that routinely contain fluid substances and are in contact with soil or an electrolyte.9.3.b. All regulated AST systems equipped with galvanic or impressed current cathodic protection systems must be inspected for proper operation by a qualified cathodic protection tester in accordance with the following requirements: 9.3.b.1. Cathodic protection systems must be tested within six months of installation and every three years thereafter by a person who, at a minimum, is NACE certified as a cathodic protection tester. However cathodic protection systems on tank bottoms in direct contact with soil or other electrolytes shall be tested within six months of installation and annually thereafter; and9.3.b.2. The owner or operator must maintain the results of the last two (2) cathodic protection tests and provide those to the Secretary upon request.9.3.c. The owner or operator of a regulated AST system with impressed current cathodic protection systems must have the rectifier inspected every sixty (60) days to ensure the equipment is operating properly. The owner or operator must maintain the results of the last six (6) rectifier readings from the impressed current system and make those available to the Secretary for inspection upon request.9.3.d. All impressed current systems shall be checked by the owner or operator and tested by a NACE certified cathodic protection tester every twelve (12) months as part of a preventative maintenance program to minimize in-service failure. The check and tests shall include a check for electrical shorts, ground connections, meter accuracy, and circuit resistance. The effectiveness of isolating devices, continuity bonds, and insulators shall be evaluated during this inspection.9.3.e. The impressed current source shall not be de-energized at any time, including periods when the facility is closed (except during power failures or during service work on the regulated AST, underground piping or impressed current system). The impressed current source shall be equipped with a continuously operating meter or meters that display voltage, amperage, and run time to show that the system is working.9.3.f. If any inspection, monitoring or testing indicates that the cathodic protection system is not functioning properly, the owner or operator shall determine the cause and immediately initiate the necessary repairs.9.3.f.1. If a cathodic protection system on a Level 1 AST system is found to be defective and the cathodic protection system is not repairable within ninety (90) days, the owner or operator shall take immediate action to remove substances from the affected AST or underground piping, as applicable, in order to protect human health or the environment.9.3.f.2. Substances shall not be returned to any affected part of the regulated AST system until the defective cathodic protection system has been repaired and passed a cathodic protection test.9.3.g. The criteria for determining the effectiveness of cathodic protection shall be a negative (cathodic) potential of at least 850 millivolts (mV) with the cathodic protection current applied. Alternatively, a negative potential of at least 850 millivolts from instant off reading or a 100mV shift from the instant off position is acceptable for impressed current systems. This potential shall be measured with respect to a saturated copper/copper sulfate reference electrode contacting the electrolyte.9.3.h. Corrosion protection testing required by this section shall be performed by a person having, at a minimum, NACE certification (or equivalent) to perform corrosion testing.9.4 Exterior Coatings. - For regulated metallic ASTs and piping, corrosion protection may consist of an appropriate external coating as specified in a nationally recognized standard or practice of a nationally recognized association, such as the Society for Protective coatings, or an independent testing laboratory.9.4.a. When exterior coatings are used as a means of corrosion protection, the owner or operator shall ensure that the exterior surfaces of all regulated aboveground tanks and piping are protected by a suitable coating that prevents corrosion and deterioration in accordance with the requirements of this section. 9.4.a.1. The owner or operator shall ensure that the coating is able to permanently bond to the regulated AST or piping and be of sufficient thickness, density, and strength to resist corrosion, deterioration, and degradation of the exterior of the AST or piping.9.4.a.2. The owner or operator shall ensure that the exterior tank and piping surfaces are properly prepared prior to the application of a coating, so that visible rust, moisture or foreign matter is not present immediately prior to the application of the coating.9.4.a.3. The owner or operator shall ensure that the exterior coating system is maintained in good condition to prevent corrosion throughout the entire operational life of the tank or piping.9.4.b. In order to prevent AST system deterioration, the owner or operator shall ensure that the regulated AST system is repaired when the following types of painting or coating failures are detected. Repairs may be made at the next scheduled maintenance activity, but in no case shall the time for repairs exceed twelve (12) months from the date of discovery for Level 1 ASTs and twenty-four (24) months for Level 2 ASTs.9.4.b.5. Coating bond failure.9.4.c. For existing regulated AST systems certified as Fit for Service but having corrosion deficiencies of their coating, the corrosion protection shall be repaired or upgraded to meet minimum requirements of this Rule and industry standards on the schedule provided by the certifying person, but in no case later than the following: 9.4.c.1. For Level 1 ASTs, the AST system component not meeting corrosion protection standards for coatings must be repaired or upgraded by June 30, 2017.9.4.c.2. For Level 2 ASTs, the AST system component not meeting corrosion protection standards for coatings must be repaired or upgraded by December 31, 2017.9.4.c.3. An existing regulated tank system that is taken out of service for internal inspection or major modification to the tank or that has been temporarily out of service and is being returned to service shall have deficiencies in the coatings upgraded or repaired prior to placing the regulated AST back into service.9.5 Interior Linings and Coatings. - Coating or lining systems may be used, as applicable, to protect tank interiors from corrosion and to meet requirements of compatibility of the AST with substances stored within the regulated AST.9.5.a. The owner or operator shall ensure that coating or lining systems that are used in the regulated ASTs are designed in accordance with current codes of practices such as API 652 or associations such as NACE. Any appropriate coating that is bonded firmly to the interior surfaces may be used to protect a tank from corrosion. Specific requirements are as follows: 9.5.a.1. Coatings and linings shall be chemically compatible with the substance to be stored. No owner or operator shall allow storage of any liquid that is not compatible with the AST system.9.5.a.2. Coating material shall be applied and cured in strict accordance with the manufacturer's specifications.9.5.a.3. Surfaces shall be prepared and inspected in accordance with applicable nationally-recognized codes and standards.9.5.a.4. Coatings used to protect the bottom of a tank shall extend up the side of the tank a minimum of 18 inches, while some forms of lining may cover the entire tank interior.9.5.a.5. Coatings shall be examined for blisters and air pockets and tested for pinholes. The coating thickness shall be checked to assure compliance with the manufacturer's specifications and industry standards.9.5.a.6. Defects in coating or lining systems shall be repaired or corrected prior to putting the tank or system into service.9.5.b. The owner or operator shall ensure that interior linings or coatings are inspected by an API or STI certified aboveground storage tank inspector, NACE certified corrosion technician or other qualified individual:9.5.b.1. At installation;9.5.b.2. When the regulated AST undergoes a major modification;9.5.b.3. As warranted or recommended by the manufacturer or design engineer;9.5.b.4. At a minimum, at least every ten years after installation of the internal lining.9.5.c. For existing regulated systems certified as Fit for Service but having known corrosion deficiencies of their internal lining noted during inspections performed to meet requirements of subdivision 9.5.b of this Rule, the corrosion protection shall be repaired or upgraded, as applicable, to meet the minimum requirements of this Rule and industry standards on the schedule provided by the certifying person, but in no case later than the following:9.5.c.1. For Level 1 ASTs, the AST system component not meeting corrosion protection standards for internal lining must be repaired or upgraded by June 30, 2017.9.5.c.2. For Level 2 ASTs, the AST system component not meeting corrosion protection standards for internal lining must be repaired or upgraded by December 31, 2017.9.5.c.3. A regulated existing tank system that is taken out of service for internal inspection or major modification to the tank or that has been temporarily out of service and is being returned to service shall have deficiencies in the internal lining upgraded or repaired prior to placing the AST back into service.