The requirements of this chapter apply to all owners and operators of an UST system, except as otherwise provided in this section.

(1) Exempt UST systems. The following UST systems are exempt from all of the requirements of this chapter:

(a) Any UST system holding hazardous wastes subject to Subtitle C of the Solid Waste Disposal Act (42 U.S.C. Sec. 6921 through 6939e), or a mixture of such hazardous waste and other regulated substances;

(b) Any wastewater treatment tank system that is part of a wastewater treatment facility regulated under Section 307(b) or 402 of the Clean Water Act (33 U.S.C. Sec. 1317(b) or 1342);

(c) Any storage tank situated in an underground area (such as a basement, cellar, vault, mineworking, drift, shaft, or tunnel) upon or above the surface of the floor so that routine physical inspection of the exterior of the tank is possible;

(d) Any UST system used solely for heating structures on the property where the system is located;

(e) Any farm or residential UST system with a capacity of one thousand one hundred gallons or less used for storing motor fuel for noncommercial purposes;

(f) Any UST system with a capacity of one hundred ten gallons or less;

(g) Any UST system that contains a de minimis concentration of regulated substances;

(h) Any emergency spill or overflow containment UST system that is expeditiously emptied after use;

(i) Any equipment or machinery that contains regulated substances for operational purposes such as hydraulic lift tanks and electrical equipment tanks;

(j) Any flow-through process tank;

(k) Any septic tank;

(l) Any stormwater or wastewater collection system;

(m) Any surface impoundment, pit, pond, or lagoon;

(n) Any liquid traps or associated gathering lines directly related to oil or gas production and gathering operations; and

(o) Any pipeline facility (including gathering lines):

(i) Which is regulated under 49 U.S.C. chapter 601; or

(ii) Which is an intrastate pipeline facility regulated under state laws as provided in 49 U.S.C. chapter 601, and which is determined by the Secretary of Transportation to be connected to a pipeline, or to be operated or intended to be capable of operating at pipeline pressure or as an integral part of a pipeline.

(2) Partially exempt UST systems.

(a) The following UST systems are partially exempt and subject only to the requirements of this chapter specified in (b) of this subsection:

(i) Any wastewater treatment tank system not regulated under Section 307(b) or 402 of the Clean Water Act (33 U.S.C. Sec. 1317(b) or 1342);

(ii) Any UST system containing radioactive material that is regulated under the Atomic Energy Act of 1954 (42 U.S.C. Sec. 2011 et seq.);

(iii) Any UST system that is part of an emergency power generator system at a nuclear power generation facility licensed by the Nuclear Regulatory Commission and subject to Nuclear Regulatory Commission requirements regarding design and quality criteria, including 10 C.F.R. Part 50; and

(iv) Any aboveground storage tanks associated with previously deferred UST systems, as defined in WAC 173-360A-0150(53).

(b) The partially exempt UST systems identified in (a) of this subsection are subject only to the following requirements of this chapter:

(i) WAC 173-360A-0200 (Licensing of UST systems);

(ii) WAC 173-360A-0210 (Fees for UST systems);

(iii) WAC 173-360A-0220 (Facility compliance tags);

(iv) WAC 173-360A-0240(3) (Availability of records);

(v) WAC 173-360A-0250 (Compliance monitoring, investigation, and access);

(vi) WAC 173-360A-0270 (Enforcement);

(vii) WAC 173-360A-0280 (Delivery prohibition);

(viii) WAC 173-360A-0290 (Civil penalties);

(ix) WAC 173-360A-0300 (Installation of UST systems and components);

(x) WAC 173-360A-0340 (Performance standards for partially exempt UST systems), except for:

(A) Aboveground storage tanks associated with previously deferred UST systems; and

(B) UST systems for which installation commenced on or before December 22, 1988;

(xi) WAC 173-360A-0400(1) and 173-360A-0405(1) (Authority to deliver or deposit regulated substances);

(xii) WAC 173-360A-0750 (Reporting and cleanup of confirmed releases);

(xiii) WAC 173-360A-0810(5) (Partially exempt UST systems – Notice of permanent closure);

(xiv) WAC 173-360A-0820(5) (Partially exempt UST systems – Notice of change-in-service); and

(xv) Part 10 of this chapter (Financial responsibility).

(3) Previously deferred UST system compliance dates.

(a) Owners and operators of previously deferred UST systems, as defined in WAC 173-360A-0150(53), installed on or before October 1, 2018, must comply with the requirements of this chapter in accordance with the schedule in Table 0110-1.

(b) Owners and operators of previously deferred UST systems installed after October 1, 2018, must comply with the requirements of this chapter upon installation.