(1) Performance standard for all UST systems. Owners and operators must ensure that all UST system components are made of or lined with materials that are compatible with the regulated substances stored in the UST system.

(2) Demonstrations for selected UST systems. Owners and operators of UST systems storing hazardous substances, regulated substances containing greater than ten percent ethanol or twenty percent biodiesel, or any other regulated substances identified by the department must also comply with the requirements of this subsection.

(a) Options. Owners and operators must either:

(i) Demonstrate compatibility of the UST system (including tanks, piping, containment sumps, pumping equipment, release detection equipment, spill prevention equipment, and overfill prevention equipment) by using one of the following options:

(A) Certification or listing of equipment or components by a nationally recognized, independent testing laboratory for use with the regulated substance stored; or

(B) Approval by the equipment or component manufacturer. The manufacturer's approval must be in writing, indicate an affirmative statement of compatibility, and specify the hazardous substances or range of biofuel blends with which the equipment or component is compatible; or

(ii) Use another option determined by the department to be no less protective of human health and the environment than the options specified in (a)(i) of this subsection.

(b) Reporting. When changing the regulated substance stored in an UST system, owners and operators must notify the department and report compliance with (a) of this subsection in accordance with WAC 173-360A-0410(1).

(c) Recordkeeping. Owners and operators must maintain all records documenting compliance with (a) of this subsection until the UST system is permanently closed or undergoes a change-in-service.

(3) Guidance. The following code of practice may be used as guidance for complying with this section: American Petroleum Institute, Recommended Practice 1626, "Storing and Handling Ethanol and Gasoline-Ethanol Blends at Distribution Terminals and Filling Stations."