1. (a) When an underground storage tank system is taken temporarily out of service for three (3) months or less, the owner or operator must meet the following requirements:

   1. (1) Continue the operation, testing, and maintenance of corrosion protection as required by this Chapter. Electricity must be maintained for an impressed current CP system to be operational.
   2. (2) Continue to monitor for leaks by performing release detection and release detection testing as required by this Chapter.
   3. (3) Perform annual inspections and testing of release detection equipment.
   4. (4) Perform thirty (30) day walkthrough inspections.
   5. (5) Perform three (3) year containment sump testing on containment sumps used for interstitial monitoring of piping.
   6. (6) Comply with the requirements of this Chapter concerning release reporting and corrective action.
   7. (7) Notify PSTD of a change in service within thirty (30) days on the prescribed TOU form.
2. (b) Tank systems that are temporarily closed for three (3) months or less are not required to meet spill prevention equipment testing and overfill prevention equipment inspections.

3. (c) When an underground storage tank system is taken out of service for three (3) months or more, the owner/operator must meet the following requirements:

   1. (1) All tanks must be drained to less than one inch (1") of residue remaining in the tank.
   2. (2) Release detection, annual release detection equipment testing and inspections, spill prevention equipment testing, overfill prevention equipment inspections, thirty (30) day walkthrough inspections, and three (3) year containment sump testing on containment sumps used for interstitial monitoring of piping, is not required as long as the underground storage tank is emptied to less than one inch (1") of residue remaining in tank.
   3. (3) All vent lines must be left open and functioning.
   4. (4) All other lines, pumps, manways, and ancillary equipment must be capped and secured.
   5. (5) Lock all fill caps.
   6. (6) Continue the operation, testing, and maintenance of corrosion protection as required by this Chapter. Electricity must be maintained for an impressed current CP system to be operational.
   7. (7) Comply with the requirements of this Chapter concerning release reporting and corrective action.
   8. (8) Notify PSTD of a change in service within thirty (30) days on the prescribed TOU form.
4. (d) Any facility with an underground storage tank registered as currently in use where the business is no longer open for regular business and has an underground storage tank system that is not in active use for greater than 180 days or two (2) consecutive semiannual inspections shall have the tank system deemed temporarily out of use and will be subject to OAC 165:25-2-133. PSTD will notify the current registered owner in writing of the change in tank status within ten (10) days of the date of change. The facility shall have sixty (60) days to comply with all requirements in this section.
5. (e) Tanks must be permanently closed if they do not meet PSTD requirements in OAC 165:25-2-133 as set forth above.

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

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

Amended at 33 Ok Reg 604, eff 8-25-16

Amended at 34 Ok Reg 935, eff 9-11-17

Amended at 36 Ok Reg 551, eff 8-1-19