Section 175.415  UST Compatibility with Product Stored

a)         Owners and operators shall use a UST made of or lined with materials that are compatible with the substance stored in the UST.

b)         Owners and operators must notify OSFM at least 30 days prior to switching to a regulated substance containing greater than 10% ethanol, greater than 20% biodiesel, or any other regulated substance identified by OSFM, using an electronic Notification for Underground Storage Tanks form (available athttps://sfm.illinois.gov/about/divisions/petroleum-chemical-safety/applications-and-forms.html).  In addition, owners and operators with UST systems storing these regulated substances must meet one of the following:

1)         Demonstrate compatibility of the UST system by completing an on-line Blended Fuel Compatibility form at the website listed in subsection (b) (to include the tank and any internal lining materials, piping, containment sumps, pumping equipment (including submersible, suction and dispenser pumps, as well as attached hoses and nozzles), release detection equipment, spill equipment, and overfill equipment and, for USTs installed after October 13, 2018, any associated seals, gaskets and adhesives). Owners and operators may demonstrate compatibility of the UST system by using one of the following options:

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

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

2)         Use another option determined by OSFM to be no less protective of human health and the environment than the options listed in subsection (b)(1). Demonstration of any such method shall be in writing submitted to OSFM. If the option is approved, the owner or operator shall comply with any conditions imposed by OSFM to ensure the protection of human health or the environment. Before the utilization of the option, OSFM shall issue written approval.

c)         Owners and operators must maintain records in accordance with 41 Ill. Adm. Code 176.430 documenting compliance with subsection (b) for as long as the UST system is used to store the regulated substance. Documentation shall include a completed Blended Fuel Compatibility form, available at the website cited in subsection (b).

d)         Existing USTs Previously Converted to a Blended Fuel (as defined in 41 Ill. Adm. Code 174.100). In those instances in which a blended fuel is being stored in an existing tank lined at any time, the lining material must be approved by OSFM based on information supplied by the manufacturer or a nationally recognized, independent testing laboratory, in accordance with the criteria identified in Section 175.500, as compatible with the blended fuel, or the owner/operator must remove the blended fuel from the tank.  Existing field installed linings shall be allowed to remain if both the lining and all UST components are compatible with the product stored, but shall comply with the requirements of Section 175.500, including requirements for 5-year inspections by a licensed contractor.  On or after May 1, 2023, new field-installed linings for compatibility purposes are only allowed for double-walled tanks equipped with interstitial monitoring.  These provisions, allowing new linings for compatibility purposes on double-walled tanks equipped with interstitial monitoring only, shall not be used to circumvent prohibitions against lining tanks for purposes of corrosion protection or repair.

e)         Blended Fuels and Compatibility. Materials and leak detection equipment that are listed as compatible with gasoline and/or petroleum diesel will be permitted to be used with gasoline/ethanol blends equal to or less than 10% ethanol or diesel/biodiesel blends equal to or less than 20% biodiesel.

(Source:  Amended at 47 Ill. Reg. 6837, effective May 2, 2023)