Existing steel tanks must be upgraded (by December 23, 1998) to meet one of the following requirements in accordance with a code of practice developed by a nationally recognized association or an independent testing laboratory:

1. (1) Interior lining. A tank may be upgraded by interior lining if:

   1. (A) The tank is repaired in accordance with 165:25-2-111 of this Chapter and the liner is installed in accordance with a recognized association or an independent testing laboratory.
   2. (B) Within 10 years after lining and every 5 years thereafter, the lined tank is internally inspected and found to be structurally sound with the lining still performing in accordance with original design specifications.

2. (2) Cathodic protection. A tank may be upgraded by cathodic protection if the cathodic protection system meets PSTD requirements and the integrity of the tank is ensured using one of the following methods:

   1. (A) The tank is internally inspected and assessed to ensure that the tank is structurally sound and free of corrosion.
   2. (B) The tank has been installed for less than 10 years and is monitored monthly for releases in accordance with PSTD requirements.
   3. (C) The tank has been installed for less than 10 years and is assessed for corrosion holes by conducting 2 tightness tests that meet PSTD requirements. The first tightness test must be conducted prior to installing the cathodic protection system. The second tightness test must be conducted between 3 and 6 months following the first operation of the cathodic protection system.
   4. (D) The tank is assessed for corrosion holes by a method that is determined by PSTD to prevent releases in a manner that is no less protective of human health and the environment that (A), (B), or (C) of this paragraph.

3. (3) Internal lining combined with cathodic protection. A tank may be upgraded by both internal lining and cathodic protection if:

   1. (A) The lining is installed in accordance with the requirements of Subchapter 2, Part 5 of this Chapter.
   2. (B) The cathodic protection system meets PSTD requirements.
   3. (C) The following codes and standards may be used to comply with 165:25-5-2: API 1631, API 1632, NLPA 631, and NACE RP-0285.

Amended at 9 Ok Reg 2305, eff 6-25-92

Amended at 11 Ok Reg 3705, eff 7-11-94

Amended at 12 Ok Reg 2047, eff 7-1-95

Amended at 15 Ok Reg 3003, eff 7-15-98

Revoked at 18 Ok Reg 2378, eff 7-1-01

Added at 22 Ok Reg 1730, eff 7-1-05

Amended at 23 Ok Reg 2261, eff 7-1-06

Amended at 25 Ok Reg 1867, eff 7-1-08