Temporary closure.
An UST or tank system is considered temporarily closed if owners and operators do not deposit regulated substance into the UST or tank system or dispense regulated substance from the UST or tank system during a time period of three hundred sixty-five days or less except.
When an UST or tank system is temporarily closed, owners and operators must continue operation and maintenance of any corrosion protection system in accordance with section 11-281-42, and any release detection method in accordance with subchapter 5. However, release detection is not required as long as the UST or tank system is empty. The UST or tank system is empty when all materials have been removed using practices commonly recognized by the industry so that no more than 2.5 centimeters (one inch) of residue, or residue that is no more than 0.3 percent by weight of the total capacity of the UST or tank system, remains in the UST or tank system.
When an UST or tank system is temporarily closed for ninety days or more, owners and operators must also comply with the following requirements:
- Leave vent lines open and functioning; and
- Cap and secure all other lines, pumps, manways ,and ancillary equipment.
When an UST or tank system is temporarily closed for more than three hundred sixty-five days, owners and operators must permanently close the UST or tank system if it does not meet the performance standards in sections 11-281-11 through 11-281-19. An UST or tank system filled by transfers of more than twenty-five gallons at one time, must meet spill and overfill prevention equipment requirements and owners and operators who fail to meet such requirements must permanently close the UST or tank system. Permanent closure must be conducted in accordance with sections 11-281-82 through 11-281-85, unless the department grants an extension of the three hundred sixty-five days temporary closure period. Owners and operators must complete a site assessment before such an extension can be requested.
Permanent closure and change-in-service.
In permanently closing or changing the service of an UST or tank system, owners and operators must comply with the requirements of this section. At least thirty days before beginning either permanent closure or a change-in-service of an UST or tank system, owners and operators must notify the department in writing of their intent to permanently close or make the change-in-service, unless such action is in response to a confirmed release. At least seven days before a permanent closure or change-in-service action, owners or operators must notify the department of the exact date (s) that the activity will occur.
To permanently close an UST or tank system, owners and operators must:
- Empty the UST and tank system by removing all liquid contents and accumulated sludges from the UST and tank system;
- Remove the UST or tank system from the ground, or leave the UST or tank system in-place and fill the UST or tank system with an inert solid material in accordance with local agency requirements; and
- Conduct a site assessment of the area beneath and around the UST or tank system.
Continued use of an UST or tank system to store a non-regulated substance is considered a change-in-service. Before a change-in-service, owners and operators must:
- Empty the UST and tank system by removing all liquid contents and accumulated sludges from the UST and tank system; and
- Conduct a site assessment of the area beneath and around the UST or tank system.