All storage tanks subject to the rules of this Chapter must be marked with a tag, lettering, or other permanent marking on the fill neck and color coded on the tank fill lids to identify the type, grade, or quality of regulated substance they contain in accordance with American Petroleum Institute (API) Recommended Practice 1637 color symbol system.

Amended at 13 Ok Reg 2405, eff 7-1-96

Amended at 18 Ok Reg 1052, eff 5-11-01

Amended at 31 Ok Reg 1003, eff 9-12-14

Amended at 33 Ok Reg 594, eff 8-25-16

Amended at 35 Ok Reg 974, eff 10-1-18

Amended at 36 Ok Reg 535, eff 8-1-19

Amended at 37 Ok Reg 1121, eff 10-1-20

Amended at 39 Ok Reg 954, eff 10-1-22