Ariz. Admin. Code § R18-12-952 - Additions, Exceptions, and Alternatives for UST Systems with Field-Constructed Tanks and Airport Hydrant Systems

A. Exception to piping secondary containment requirements. Owners and operators may use single walled piping when installing or replacing piping associated with UST systems with field-constructed tanks greater than 50,000 gallons and piping associated with airport hydrant systems.

B. Piping associated with UST systems with field-constructed tanks less than or equal to 50,000 gallons not part of an airport hydrant system shall meet the secondary containment requirement when installed or replaced. Where the piping to be replaced exceeds the percentage in A.R.S. § 49-1009(C), the entire piping run shall be secondarily contained.

C. Upgrade requirements. Airport hydrant systems and UST systems with field-constructed tanks shall meet the following requirements or be permanently closed pursuant to R18-12-270 through R18-12-274 .

1. Corrosion protection. UST system components in contact with the ground that routinely contain regulated substances shall meet one of the following:

a. Except as provided in subsection (A) of this Section, the new UST system performance standards for tanks at R18-12-220(A) and for piping at R18-12-220(B); or

b. Be constructed of metal and cathodically protected according to a code of practice developed by a nationally recognized association or independent testing laboratory and meets the following:

i. Cathodic protection shall meet the requirements of R18-12-220(A)(2)(ii), (iii) and (iv) for tanks, and R18-12-220(B)(2)(ii), (iii), and (iv) for piping.

ii. Tanks greater than 10 years old without cathodic protection shall be assessed to ensure the tank is structurally sound and free of corrosion holes prior to adding cathodic protection. The assessment shall be by internal inspection or another method determined by the Department to adequately assess the tank for structural soundness and corrosion holes.

Note to subsection (C)(1): The following codes of practice may be used to comply with this subsection:

(A) NACE International Standard Practice SP0285-2011, "Corrosion Control of Underground Storage Tank Systems by Cathodic Protection";

(B) NACE International Standard Practice SP0169-2013, "Control of External Corrosion on Underground or Submerged Metallic Piping Systems";

(C) National Leak Prevention Association Standard 631, Chapter C, "Internal Inspection of Steel Tanks for Retrofit of Cathodic Protection", 2009 revision; or

(D) American Society for Testing and Materials Standard G158-98, "Standard Guide for Three Methods of Assessing Buried Steel Tanks".

2. Spill and overfill prevention equipment. To prevent spilling and overfilling associated with product transfer to the UST system, all UST systems with field-constructed tanks and airport hydrant systems shall comply with new UST system spill and overfill prevention equipment requirements specified in R18-12-220(C).

D. Walkthrough inspections. In addition to the walkthrough inspection requirements in R18-12-236, owners and operators shall inspect the following additional areas for airport hydrant systems at least once every 30 days if confined space entry according to the Occupational Safety and Health Administration (see 29 CFR part 1910) is not required or at least annually if confined space entry is required and keep documentation of the inspection according to R18-12-236(B) .

1. Hydrant pits - visually check for any damage; remove any liquid or debris; and check for any leaks, and

2. Hydrant piping vaults - check for any hydrant piping leaks.

E. Release detection. Owners and operators of UST systems with field-constructed tanks and airport hydrant systems shall meet the release detection requirements described in this Article as follows:

1. Methods of release detection for field-constructed tanks. Owners and operators of field-constructed tanks with a capacity less than or equal to 50,000 gallons shall meet the release detection requirements in R18-12-240 through R18-12-245 . Owners and operators of field-constructed tanks with a capacity greater than 50,000 gallons shall meet either the requirements in R18-12-240 through R18-12-245 (except R18-12-243(E) and (F) shall be combined with inventory control as stated below) or use one or a combination of the following alternative methods of release detection:

a. Conduct an annual tank tightness test that can detect a 0.5 gallon per hour leak rate;

b. Use an automatic tank gauging system to perform release detection at least every 30 days that can detect a leak rate less than or equal to one gallon per hour. This method shall be combined with a tank tightness test that can detect a 0.2 gallon per hour leak rate performed at least every three years;

c. Use an automatic tank gauging system to perform release detection at least every 30 days that can detect a leak rate less than or equal to two gallons per hour. This method shall be combined with a tank tightness test that can detect a 0.2 gallon per hour leak rate performed at least every two years;

d. Perform vapor monitoring (conducted in accordance with R18-12-243(E) for a tracer compound placed in the tank system) capable of detecting a 0.1 gallon per hour leak rate at least every two years;

e. Perform inventory control (conducted in accordance with Department of Defense Directive 4140.25-M, volume 9; ATA Airport Fuel Facility Operations and Maintenance Guidance Manual, revision 2004.1; or equivalent procedures) at least every 30 days that can detect a leak equal to or less than 0.5 percent of flow-through; and

i. Perform a tank tightness test that can detect a 0.5 gallon per hour leak rate at least every two years; or

ii. Perform vapor monitoring or groundwater monitoring (conducted in accordance with R18-12-243(E) or (F), respectively, for the stored regulated substance) at least every 30 days; or

f. Another method approved by the Department if the owner and operator can demonstrate that the method can detect a release as effectively as any of the methods allowed in subsections (E)(1)(a) through (e) of this Section. In comparing methods, the Department shall consider the size of release that the method can detect and the frequency and reliability of detection.

2. Methods of release detection for piping. Owners and operators of underground piping associated with field-constructed tanks less than or equal to 50,000 gallons shall meet the release detection requirements in R18-12-240 through R18-12-245 . Owners and operators of underground piping associated with airport hydrant systems and field-constructed tanks greater than 50,000 gallons shall follow either the requirements in R18-12-240 through R18-12-245 (except R18-12-243(E) and (F) shall be combined with inventory control as stated below) or use one or a combination of the following alternative methods of release detection:

i. Perform a semiannual or annual line tightness test at or above the piping operating pressure in accordance with the table below.

Maximum Leak Detection Rate Per Test Section Volume
Test Section Volume (Gallons)	Semiannual Test -Leak Detection Rate Not To Exceed (Gallons Per Hour)	Annual Test - Leak Detection Rate Not To Exceed (Gallons Per Hour)
< 50,000	1.0	0.5
>= 50,000 to < 75,000	1.5	0.75
>= 75,000 to < 100,000	2.0	1.0
>= 100,000	3.0	1.5

ii. Piping segment volumes >=100,000 gallons not capable of meeting the maximum 3.0 gallon per hour leak rate for the semiannual test may be tested at a leak rate up to 6.0 gallons per hour according to the following schedule:

Phase In For Piping Segments >= 100,000 Gallons In Volume
First test	Not later than March 1, 2020 (may use up to 6.0 gph leak rate)
Second test	Between March 1, 2020 and March 1, 2023 (may use up to 6.0 gph leak rate)
Third test	Between March 1, 2023 and March 1, 2024 (may use up to 3.0 gph leak rate)
Subsequent tests	After March 1, 2024, begin using semiannual or annual line testing according to the Maximum Leak Detection Rate Per Test Section Volume table above

b. Perform vapor monitoring (conducted in accordance with R18-12-243(E) for a tracer compound placed in the tank system) capable of detecting a 0.1 gallon per hour leak rate at least every two years;

c. Perform inventory control (conducted in accordance with Department of Defense Directive 4140.25m, volume 9; ATA Airport Fuel Facility Operations and Maintenance Guidance Manual, revision 2004.1; or equivalent procedures) at least every 30 days that can detect a leak equal to or less than 0.5 percent of flow-through; and

i. Perform a line tightness test (conducted in accordance with subsection (D)(2)(a) of this Section using the leak rates for the semiannual test) at least every two years; or

ii. Perform vapor monitoring or groundwater monitoring (conducted in accordance with R18-12-243(E) or (F), respectively, for the stored regulated substance) at least every 30 days; or

d. Another method approved by the Department if the owner and operator can demonstrate that the method can detect a release as effectively as any of the methods allowed in subsections (E)(2)(a) through (c) of this Section. In comparing methods, the Department shall consider the size of release that the method can detect and the frequency and reliability of detection.

3. Recordkeeping for release detection. Owners and operators shall maintain release detection records according to the recordkeeping requirements in R18-12-245.

F. Applicability of closure requirements to previously closed UST systems. When directed by the Department, the owner and operator of an UST system with field-constructed tanks or airport hydrant system permanently closed before January 1, 2020 shall assess the excavation zone and close the UST system in accordance with R18-12-270 through R18-12-274 if releases from the UST may, in the judgment of the Department, pose a current or potential threat to human health and the environment.

Notes

Ariz. Admin. Code § R18-12-952

Adopted by final rulemaking at 25 A.A.R. 3123, effective 10/1/2020.