organic liquids distribution (non-gasoline) mact summary

5. What are the HAP emission limits, operating limits and other applicable standards under this rule?

The requirements of this rule were promulgated in the form of HAP emission limits (i.e., percent reduction or exhaust concentration), operating limits, and work practice standards. The work practice standards are a combination of design, equipment, and operational standards.

This NESHAP contains emission standards for storage tanks, transfer racks, transport vehicles, and equipment components at existing and new OLD operations.

The standards for storage tanks apply to tanks storing organic liquids and meeting the tank capacity and liquid HAP vapor pressure applicability criteria given in Table 2 to Subpart EEEE of Part 63. Facilities with affected sources have three options for control:

• First, they may install a closed vent system and control device with at least 95 percent control efficiency for the organic HAP listed in Table 1 to Subpart EEEE of Part 63. They may also choose to demonstrate that the measurement of total organic compounds (TOC) is an appropriate surrogate for organic HAP. As an alternative option to the 95 percent standard, combustion devices may meet an exhaust concentration limit of 20 parts per million by volume (ppmv) of organic HAP or TOC.

• Second, a facility may capture and route emissions to a fuel gas system or back into a process.

• Third, a facility may choose to meet a work practice standard by using a compliant internal or external floating roof in the affected storage tank. The tank size and liquid vapor pressure applicability criteria defining tanks subject to emission reduction requirements are different for tanks at existing or new affected sources. The owner or operator will have to install a continuous monitoring system (CMS) and establish operating limits for each control device used to control storage tanks. The CMS may be of a type to measure either organic concentration in the gas stream or an operating parameter (such as fire box temperature) of the control device. A site-specific monitoring plan must be developed and submitted by the owner or operator for each emission source.

The emission limit for transfer racks is a closed vent system and control device achieving a control efficiency of at least 98 percent for the organic HAP listed in Table 1 to Subpart EEEE of Part 63. A facility with an affected source may also utilize a vapor balancing system to achieve the required control efficiency. They may also choose to demonstrate that the measurement of TOC is an appropriate surrogate for organic HAP. As an alternative option to the 98 percent standard, combustion devices may meet an exhaust concentration limit of 20 ppmv of organic HAP or TOC. Only transfer racks meeting the specified applicability criteria in this rule are required to implement emission reduction measures. The same emission limit applies to affected transfer racks at both existing and new affected sources. The same requirements for installing a CMS and establishing operating limits for the control device applicable to storage tanks also apply to the control systems installed on transfer racks.

A work practice standard applies to pumps, valves, and sampling connection systems. These equipment leak components in organic liquids service must be included in a leak detection and repair (LDAR) program which requires the use of a detection instrument. The term "in organic liquid service'' is defined in this rule to mean an equipment leak component that contains or contacts organic liquids having 5 percent by weight or greater of the organic HAP listed in Table 1 to Subpart EEEE of Part 63. Owners/operators have the option of applying the provisions from 40 CFR Part 63, subpart TT, Subpart UU, or Subpart H for their LDAR program. The LDAR standard applies to equipment leak components at both existing and new affected sources.

A work practice standard applies to transport vehicles (cargo tanks and tank cars) loading at affected transfer racks. Each of these vehicles must have current vapor tightness certification indicating that it has been properly tested for vapor tightness. If the vehicle is equipped with vapor collection equipment, the vehicle must be tested using EPA Method 27 on an annual basis. For vehicles not so equipped, the Department of Transportation (DOT) leak tightness standards apply, and current certification indicating that these standards have been met must be retained by the owner or operator for each vehicle that loads at affected transfer racks whether the source owns the vehicle or not. The owner/operator is not required to test transport vehicles they do not own, but they must take adequate steps to ensure that uncertified vehicles are not loaded at affected racks. These work practice standards are the same for both existing and new affected sources.