Storage Tank Closure
If an underground tank is to be taken out of service for less than 180 days the liquid level must be measured at least monthly and tank openings and nozzles must be locked. If the closure is more than 180 days any gasoline stored must be removed and the tank inerted using dry ice. If a combustible liquid is to remain in the tank it must be measured at least monthly. Fill pipes and nozzles must be locked. If a tank system has been out of service for a period of longer than one year tanks and piping must be precision tested before being put back into service.
If an underground tank system has no further use or has been out of service for two years, the Authority Having Jurisdiction must be notified in writing at least 30 days prior to removal, liquids removed, vapors purged and the system be removed from the ground after receiving a removal permit. Piping can remain if purged of vapors and the ends permanently plugged. If the soil is contaminated, the Fire Authority and Alberta Environment must be notified by calling 1-800-222-6514 and the contaminated soil removed, treated or replaced in a manner that is satisfactory to the Authorities Having Jurisdiction.
Abandonment in Place
Where it is not practical to remove an underground tank, it may be left in place if permission is granted by the Authority Having Jurisdiction. The circumstances and conditions that may allow abandonment in place are listed in Article 220.127.116.11 of the Alberta Fire Code, but generally, if it's physically possible to remove the tank, it must be removed.
Underground tanks shall not be removed and reused unless refurbished to an appropriate ULC standard.
Storage Tank Closures (Aboveground Tanks)
If a tank will be out of service for less than 180 days the piping must be capped or valves closed and locked. Liquid levels must be recorded at least monthly. If the tank will be out of service for more than 180 days the liquid and vapors must be removed and the tank clearly marked to indicate it is empty. The PTMAA should be notified of any changes in the tank's registration.
Where possible, aboveground tank shall be internally inspected. The Authority Having Jurisdiction must be advised of the inspection results and intention to reuse the tank.