Permanent closure and changes in service

1. At least thirty days before beginning either permanent closure or a change in service under subsections 2 and 3, or within another reasonable time period determined by the department, owners and operators must notify the department of their intent to permanently close or make the change in service, unless such action is in response to corrective action. The required assessment of the excavation zone under section 33.1-24-08-62 must be performed after notifying the department, but before completion of the permanent closure or a change in service. 2. To permanently close a tank, owners and operators must empty and clean it by removing all liquids and accumulated sludges. All tanks taken out of service permanently must be removed from the ground, filled with an inert solid material, or closed in place in a manner approved by the department. 3. Continued use of an underground storage tank system to store a nonregulated substance is considered a change in service. Before a change in service, owners and operators must empty and clean the tank by removing all liquid and accumulated sludge and conduct a site assessment in accordance with section 33.1-24-08-62. NOTE: The following cleaning and closure procedures may be used to comply with this section: American Petroleum Institute Recommended Practice RP 1604, "Closure of Underground Petroleum Storage Tanks"; American Petroleum Institute Standard 2015, "Safe Entry and Cleaning of Petroleum Storage Tanks, Planning and Managing Tank Entry From Decommission Through Recommissioning"; American Petroleum Institute Recommended Practice 2016, "Guidelines and Procedures for Entering and Cleaning Petroleum Storage Tanks", American Petroleum Institute Recommended Practice RP 1631, "Interior Lining and Periodic Inspection of Underground Storage Tanks", may be used as guidance for compliance with this section; National Fire Protection Association Standard 326, "Standard for the Safeguarding of Tanks and Containers for Entry, Cleaning, or Repair"; and The National Institute for Occupational Safety and Health Publication 80-106 "Criteria for a Recommended Standard: Working in Confined Spaces" may be used as guidance for conducting safe closure procedures at some hazardous substance tanks.