(a) For each storage vessel to which this subpart applies, the owner or operator shall comply with the requirements of paragraph (b) or (c) of this section.

(b) For each storage vessel storing a liquid for which the maximum true vapor pressure of the total regulated material in the liquid is less than 76.6 kilopascals (10.9 pounds per square inch), the owner or operator shall reduce regulated material emissions to the atmosphere as provided in any one of the paragraphs (b)(1) through (7) of this section.

(1) Internal floating roof (IFR). Operate and maintain a fixed roof and internal floating roof meeting the requirements of §65.43.

(2) External floating roof (EFR). Operate and maintain an external floating roof meeting the requirements of §65.44.

(3) EFR converted to IFR. Operate and maintain an external floating roof converted to an internal floating roof meeting the requirements of §65.45.

(4) Closed vent system and flare. Operate and maintain a closed vent system and flare as specified in §65.142(a)(1). Periods of planned routine maintenance of the flare during which the flare does not meet the specifications of §65.147 shall not exceed 240 hours per year. The specifications and requirements in §65.147 for flares do not apply during periods of planned routine maintenance or during a control system malfunction. The owner or operator shall report the periods of planned routine maintenance as specified in §65.166(d).

(5) Closed vent system and control device. Operate and maintain a closed vent system and control device as specified in the following and §65.142(a)(2):

(i) Except as provided in paragraph (b)(5)(ii) of this section, the control device shall be designed and operated to reduce inlet emissions of regulated material by 95 percent or greater.

(ii) For owners or operators referenced to this part from 40 CFR part 63, subpart G, and if the owner or operator of a storage vessel can demonstrate that a control device installed on the storage vessel on or before December 31, 1992 is designed to reduce inlet emissions of total organic HAP by greater than or equal to 90 percent but less than 95 percent, then the control device is required to be operated to reduce inlet emissions of total organic HAP by 90 percent or greater.

(iii) Periods of planned routine maintenance of the control device, during which the control device does not meet the specifications of paragraph (b)(5)(i) or (ii) of this section, shall not exceed 240 hours per year. The owner or operator shall report the periods of planned routine maintenance as specified in §65.166(d).

(iv) The requirements in paragraph (b)(5)(i) of this section for control devices do not apply during periods of planned routine maintenance or during a control system malfunction.

(6) Route to process or fuel gas system. Route the emissions to a process or a fuel gas system as specified in §65.142(a)(3). Whenever the owner or operator bypasses the fuel gas system or process, the owner or operator shall comply with the recordkeeping requirement in §65.163(b)(3). Bypassing is permitted if the owner or operator complies with one or more of the following conditions:

(i) The liquid level in the storage vessel is not increased;

(ii) The emissions are routed through a closed vent system to a control device complying with paragraph (b)(4) or (5) of this section; or

(iii) The total aggregate amount of time during which the emissions bypass the fuel gas system or process during the calendar year without being routed to a control device, for all reasons (except startups/shutdowns/malfunctions or product changeovers of flexible operation units and periods when the storage vessel has been emptied and degassed), does not exceed 240 hours.

(7) Equivalent requirements. Comply with an equivalent to the requirements in any one of the paragraphs (b)(1) through (6) of this section, as provided in §65.46.

(c) For each storage vessel storing a liquid for which the maximum true vapor pressure of the total regulated material in the liquid is greater than or equal to 76.6 kilopascals (10.9 pounds per square inch), the owner or operator shall meet the requirements in paragraph (b)(4), (5), or (6) of this section, or equivalent as provided in §65.46.