15A NCAC 02N .0903. TANKS

(a)  Tanks must be protected from external corrosion in accordance with 40 CFR 280.20(a)(1), (3) or (5).

(b)  The exterior surface of a tank shall bear a permanent marking, code stamp or label showing the following information:

(1)           The engineering standard used;

(2)           The diameter in feet;

(3)           The capacity in gallons;

(4)           The materials of construction of the inner and outer walls of the tank including any external or internal coatings;

(5)           Serial number or other unique identification number designated by the tank manufacturer;

(6)           Date manufactured; and

(7)           Identity of manufacturer.

(c)  Whenever an existing tank is removed prior to installation of a new tank, piping that does not meet the standards of this Section shall also be removed.  The replacement tank shall not be connected to piping that does not meet the standards of this Section.

(d)  Tanks that will be reused must be certified by the tank manufacturer prior to re-installation and must meet all of the requirements of this Section.  Tank owners and operators must submit proof of certification to the Division along with a notice of intent (Rule .0902).

(e)  Tanks shall be tested before and after installation in accordance with the following requirements:

(1)           Pre- Installation Test - Before installation, the primary containment and the interstitial space shall be tested in accordance with the manufacturers written guidelines and PEI/RP100, "Recommended Practice for Installation of Underground Liquid Storage Systems."  PEI/RP100, "Recommended Practice for Installation of Underground Liquid Storage Systems" is hereby incorporated by reference including subsequent amendments and editions.  A copy can be obtained from Petroleum Equipment Institute, P.O. Box 2380, Tulsa, Oklahoma 74101-2380 at a cost of ninety-five dollars ($95.00).  The presence of soap bubbles or water droplets during a pressure test, any change in vacuum beyond the limits specified by the tank manufacturer during a vacuum test, or any change in liquid level in an interstitial space liquid reservoir beyond the limits specified by the tank manufacturer, shall be considered a failure of the integrity of the tank.

(2)           Post-installation Test – The interstitial space shall be checked for a loss of pressure or vacuum, or a change in liquid level in an interstitial space liquid reservoir.  Any loss of pressure or vacuum beyond the limits specified by the tank manufacturer, or a change in liquid level beyond the limits specified by the tank manufacturer, shall be considered a failure of the integrity of the tank.

(3)           If a tank fails a pre-installation or post-installation test, tank installation shall be suspended until the tank is replaced or repaired in accordance with the manufacturer's specifications.  Following any repair, the tank shall be re-tested in accordance with Subparagraph (e)(1) of this Rule if it failed the pre-installation test and in accordance with Subparagraph (e)(2) of this Rule if it failed the post-installation test.

(f) The interstitial spaces of tanks that are not monitored using vacuum, pressure or hydrostatic methods must be tested for tightness before UST system start-up, between six months and the first anniversary of start-up and every three years thereafter.  The interstitial space shall be tested using an interstitial tank tightness test method that is capable of detecting a 0.10 gallon per hour leak rate with a probability of detection (Pd) of at least 95 percent and a probability of false alarm (Pfa) of no more than five percent.  The test method must be evaluated by an independent testing laboratory, consulting firm, not-for-profit research organization or educational institution using the most recent version of the United States Environmental Protection Agency's (EPA's) "Standard Test Procedures for Evaluating Leak Detection Methods." EPA's "Standard Test Procedures for Evaluating Leak Detection Methods" is hereby incorporated by reference including subsequent amendments and additions.  A copy may be obtained by visiting EPA's Office of Underground Storage Tank web site:  www.epa.gov/OUST/pubs/protocol.htm at a cost of zero dollars ($0.00).  The independent testing laboratory, consulting firm, not-for-profit research organization or educational institution must certify that the test method can detect a 0.10 gallon per hour leak rate with a Pd of at least 95 percent and a Pfa of no more than five percent for the specific tank model being tested.  If a tank fails an interstitial tank tightness test, it must be replaced or repaired by the manufacturer or the manufacturer's authorized representative in accordance with manufacturer's specifications.  Tank owners and operators shall report all failed interstitial tank tightness tests to the Division within 24 hours.  Following any repair, the tank interstitial space shall be re-tested for tightness.  The most recent interstitial tightness test record must be maintained at the UST site or the tank owner's place of business and must be available for inspection.

 

History Note:        Authority G.S. 143-215.3(a)(15); 143B-282(a)(2)(h);

Eff. November 1, 2007;

Amended Eff. February 1, 2010.