Within 30 days after the last date the tank was used, the owner/operator must submit a written request for temporary closure status to the OSFM. A UST may remain in temporary closure status for 5 years from the date of last use if it meets the following requirements.
- The tank and product lines must be emptied so that no more than one inch of residue remains. If more than one inch of product remains, release detection equipment must continue to be maintained.
- Cathodic protection equipment must be maintained. The cathodic protection system must be tested as required and records kept of those test results.
- Within 30 days after the last date the tank was used, the owner/operator must submit a written request for temporary closure status to the OSFM.
- Vent lines must be left open and functioning.
- Within 7 days after the last date the tank was used, the owner/operator must cap and secure all product lines, and secure all pumps, manways, and ancillary equipment.
- The owner/operator must inspect the UST every 6 months for compliance with temporary closure requirements and submit a form to the OSFM attesting to compliance status.
Return to Service
A UST that has been out of service for over one year but less than five years may be returned to service if the following requirements are met.
- Both tanks and lines must pass a precision test.
- Tank and line release detection equipment must be tested and operational.
- Cathodic protection systems must be tested and must meet performance requirements.
- A site assessment must be conducted.
The precision test, release detection test, and cathodic protection test must be performed at least 30 days and not more than 90 days prior to returning the UST to service. The reports on these tests must be submitted to the OSFM at least 10 days prior to returning the UST to service. Single-walled USTs over 30 years old in temporary closure for over one year may not be returned to service and must be removed.
A change-in-service is any change in the substance stored within a storage tank.
- To change a UST from a regulated substance to a non-regulated substance, the UST must be emptied and cleaned and a site assessment must be conducted. This kind of change-in-service may only occur within two years of the date of installation.
- To change a UST from a regulated substance to a different regulated substance, the UST must be emptied and cleaned, and its compatibility with the new regulated substance verified.
- Changing from a non-regulated substance to a regulated substance is not allowed unless the tank has been re-certified as a UST and it complies with all applicable upgrade requirements (including release detection, spill and overfill protection, and corrosion protection) for newly installed USTs.
Before any change-in-service, the owner/operator must notify the OSFM at least 30 days prior to the change-in-service and the tank must be certified as compatible with the new substance stored.
- If a UST is not returned to service within 5 years from the date of last use, the UST must be removed from the ground within 60 days of the end of the 5-year period. The owner/operator must ensure that a removal permit is obtained and a removal date scheduled with the OSFM. The owner/operator must also ensure that a site assessment is performed, usually within 24 hours after the UST removal. The removal must be conducted by an OSFM-licensed contractor. The owner/operator must also file a Certification of Removal form with the OSFM.
- The removal requirement does not apply while the tank manufacturer’s warranty is in place if corrosion protection has been and continues to be maintained, a site assessment has been performed, defective UST components have been replaced 45 days prior to return to service, and all of the return-to-service requirements previously listed have been met.
- Abandonment-in-place is when a UST is left in the ground instead of removed. No tank or piping may be abandoned-in-place unless the permit applicant can demonstrate that removal of the UST:
- Would weaken support for adjacent structures;
- Is not feasible due to the UST’s inaccessibility; or
- Is not feasible for any other reason, as determined by the OSFM.
- If abandonment-in-place is allowed, an on-site evaluation must be conducted and a Certification of Site Conditionprepared. The tank and all associated piping must be emptied and rendered free of explosive vapors, and the tank filled with an inert solid material. The owner/operator must file a Certification of Abandonment-in-Place form with the OSFM. The owner/operator must keep a permanent record of the UST location, the date of abandonment-in-place, and the procedure used for abandonment-in-place.