PURPOSE: This rule contains the requirements for permanent closure of underground storage tanks as well as for converting underground storage tanks to an unregulated use.

Editor’s Note: The secretary of state has determined that the publication of this rule in its entirety would be unduly cumbersome or expensive. The entire text of the material referenced has been filed with the secretary of state. This material may be found at the Office of the Secretary of State or at the headquarters of the agency and is available to any interested person at a cost established by state law.

1. (1) Owners and operators must notify the department in writing, on forms provided by the department, at least thirty (30) days before beginning either permanent closure or a change in service of an underground storage tank (UST) in sections (2) and (3) of this rule or within another reasonable time period determined by the department, unless this action is in response to corrective action. The required assessment of the excavation zone under 10 CSR 20-10.072 must be performed after notifying the department but before completion of the permanent closure or a change in service.
2. (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 also be either removed from the ground or filled with an inert solid material.
3. (3) Continued use of a UST system to store a nonregulated substance is 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 10 CSR 20- 10.072.

4. (4) Owners and operators shall follow a written procedure. To comply with this rule, the department’s UST Closure Guidance Document may be used as a written procedure. It may be supplemented with the following cleaning and closure procedures:

   1. (A) American Petroleum Institute Recommended Practice 1604, Removal and Disposal of Used Underground Petroleum Storage Tanks;
   2. (B) American Petroleum Institute Publication 2015, Cleaning Petroleum Storage Tanks;
   3. (C) American Petroleum Institute Recommended Practice 1631, Interior Lining of Underground Storage Tanks; and
   4. (D) Owners and operators may use other written procedures with prior written approval of the department.

AUTHORITY: sections 319.111, RSMo (Cum. Supp. 1989) and 644.026, RSMo (Cum. Supp. 1993).* Original rule filed April 2, 1990, effective Sept. 28, 1990. Amended: Filed Aug. 3, 1993, effective April 9, 1994. *Original authority: 319.111, RSMo (1989) and 644.026, RSMo (1972), amended 1973, 1987, 1993.