| (a) Inspection requirements. The following inspection requirements apply during the degassing of any storage tank, transport vessel, or marine vessel subject to this division. (1) Inspection for visible liquid leaks, visible fumes, or significant odors resulting from volatile organic compounds (VOC) transfer operations must be conducted during each degassing operation. (2) Degassing through the affected transfer lines must be discontinued when a leak is observed and the leak cannot be repaired within a reasonable length of time. (b) Monitoring requirements. The following monitoring requirements apply during the degassing of any storage tank, transport vessel, or marine vessel subject to this division. Monitoring at least once every 15 minutes is sufficient to demonstrate compliance with the continuous monitoring requirements in this subsection. (1) Any monitoring device used to comply with this subsection must be installed, calibrated, maintained, and operated according to the manufacturer's instructions. (2) The owner or operator shall monitor any operational parameters necessary to demonstrate the proper functioning of a control device used to comply with this division at all times when VOC vapors are routed to the device. (A) For a carbon adsorption system, the owner or operator shall continuously monitor the exhaust gas VOC concentration of any carbon adsorption system that regenerates the carbon bed directly to determine breakthrough. Alternatively, the owner or operator shall periodically monitor the exhaust gas VOC determine breakthrough and switch the exhaust gas flow to fresh carbon for any carbon adsorption system that does not regenerate the carbon bed directly, as specified by 40 Code of Federal Regulations (CFR) §61.354(d) (as amended through October 17, 2000 (65 FR 62160)), except that any monitoring must be conducted at intervals no greater than 20% of the design carbon replacement interval. For the purpose of this division, breakthrough is defined as a measured VOC concentration exceeding 100 parts per million by volume (ppmv) above background expressed as methane. (B) For a catalytic incinerator, the owner or operator shall continuously monitor the inlet and outlet gas temperature. (C) For a condensation system, the owner or operator shall continuously monitor the outlet gas temperature to ensure the temperature is below the manufacturer's recommended operating temperature for controlling the VOC vapors routed to the device. (D) For a direct-flame incinerator, the owner or operator shall continuously monitor the exhaust gas temperature immediately downstream of the device. (E) For a flare, the owner or operator shall use one of the following methods to demonstrate compliance with the requirements in 40 CFR §60.18 (as amended through December 22, 2008 (73 FR 78209)). (i) The owner or operator shall continuously monitor the net heating value of the gas stream routed to the flare. (ii) The owner or operator shall continuously monitor the total volume of supplemental fuel added to the gas stream routed to the flare and continuously maintain sufficient supplemental fuel to meet the minimum net heating value requirements in 40 CFR §60.18 assuming that the net heating value contribution from the degassed VOC vapor is equivalent to a level corresponding to 50% of the lower explosive limit (LEL). The owner or operator may estimate the volumetric flow rate from the tank or vessel for the purpose of this calculation if the flow rate of the degassed VOC vapor is not directly monitored. (iii) The owner or operator shall use calculations to demonstrate that for the material stored in the tank or vessel the net heating value of the gas stream routed to the flare cannot drop below the minimum net heating value requirements in 40 CFR §60.18 until the concentration of VOC in the vapors being routed to the flare is less than the concentration limits in §115.542(b) of this title (relating to Control Requirements). (iv) If the flare is a non-assisted flare that qualifies for the provisions in 40 CFR §60.18(c)(3)(i), the owner or operator may elect to continuously monitor the hydrogen content of the gas stream routed to the flare and continuously meet the minimum 8.0% by volume hydrogen content requirement in lieu of the requirements in clauses (i) - (iii) of this subparagraph. (F) For any control device used to comply with the optional exhaust gas concentration limit in §115.542(a)(4) of this title, the owner or operator shall monitor the exhaust gas VOC concentration within one hour after beginning the degassing operation. The VOC concentration measurement must be a one-hour test run using one of the following methods: (i) the integrated bag sampling procedure in Method 18 (40 CFR Part 60, Appendix A), §§8.2.1.1 - 8.2.1.4, and a total hydrocarbon analyzer that meets instrument and calibration specifications in Method 21; or (ii) Method 25A (40 CFR Part 60, Appendix A) to monitor the exhaust gas VOC concentration. (G) For a thermal oxidizer or vapor combustor, the owner or operator shall continuously monitor the combustion chamber temperature. If necessary to demonstrate compliance with subsection (c)(3) of this section, the owner or operator shall also continuously monitor the gas flow rate into the thermal oxidizer or vapor combustor to determine the combustion chamber residence time. (H) For a recirculation system, the owner or operator shall: (i) continuously monitor the pressure inside the tank or vessel or continuously monitor the gas flow rate at the inlet and outlet of the control device; and (ii) monitor all components of the recirculation system, including all valves and connectors, for VOC leaks using the procedure in Method 21 (40 CFR Part 60, Appendix A-7) and begin this monitoring within one hour after beginning any degassing operation. A leak is defined as a screening concentration greater than 500 ppmv above background as methane for all components. (I) For an internal combustion engine, the owner or operator shall continuously monitor the engine exhaust gas oxygen content throughout the degassing operation. (J) For a control device not listed in this paragraph, the owner or operator shall continuously monitor one or more operational parameters sufficient to demonstrate proper functioning of the control device to design specifications. (3) The owner or operator shall monitor the VOC concentration to demonstrate compliance with the VOC concentration or percent LEL thresholds in §115.542(b) of this title and determine if the storage tank, transport vessel, or marine vessel can be vented to the atmosphere without control for the remainder of the degassing operation, except as specified in paragraph (4) of this subsection. The VOC concentration must be monitored: (A) once per minute for at least five minutes and all measurements must be less than the VOC concentration limits in §115.542(b) of this title; or (B) over a five-minute period using the integrated bag sampling procedure in Method 18 (40 CFR Part 60, Appendix A) §§8.2.1.1 - 8.2.1.4 and the integrated measurement must be less than the VOC concentration limits in §115.542(b) of this title. (4) After demonstrating compliance with the applicable VOC concentration or percent LEL thresholds in §115.542(b) of this title in accordance with paragraph (3) of this subsection, the owner or operator of any storage tank, transport vessel, or marine vessel shall comply with one of the following conditions. (A) The VOC concentration inside the tank or vessel must be monitored once every 12 hours while venting to the atmosphere without control until five consecutive measurements collected at 12 hour intervals are measured to be less than 34,000 ppmv expressed as methane or less than 50% of the LEL. The VOC concentration measurement required by paragraph (3) of this subsection may be considered the first of these five consecutive measurements. (i) If venting to the atmosphere without control has been suspended for more than four hours, the VOC concentration inside the tank or vessel must be measured upon restart of the degassing operation. (ii) If any of the VOC concentration measurements equal or exceed 34,000 ppmv expressed as methane or 50% of the LEL, the tank or vessel must be routed to the control device until the VOC concentration is below 34,000 ppmv expressed as methane or less than 50% of the LEL as determined by subsection (b)(3) of this section. (iii) If the measured VOC concentration is less than 6,800 ppmv expressed as methane or 10% of the LEL then no further VOC concentration measurements are required. Cont'd... |
