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National Emission Standards for Hazardous Air Pollutants (NESHAPS)
Part 1. Miscellaneous process vents On June 12, 1996 (61 FR 29876-29882), EPA published correcting amendments to the NESHAPS for petroleum refineries. These amendments correct errors and clarify text of the petroleum refinery NESHAPS that was promulgated as 40 CFR Subpart CC on August 18, 1995 (60 FR 43243-43297). The petroleum refinery NESHAPS require petroleum refineries that are major sources of HAPs to meet emission standards by employing MACT. Any refinery with more than 10 tons/yr of any single HAP or more than 25 tons/yr of total HAPs is a major source. This rule was effective August 18, 1995. Affected by this rule are new and existing sources in the following source categories:
Marine tank vessel loading operations and gasoline loading operations are affected by this rule only if they are located within the boundaries of the petroleum refinery. Each source category is discussed in more detail below.
Miscellaneous process vents are defined as individual vents from petroleum refining process units that emit organic HAPs. The miscellaneous process vents are divided into Group 1 and Group 2 streams. The rule requires that organic HAP emissions from Group 1 vents be reduced by 98% or to less than 20 ppmv. Group 2 vents do not need to be controlled. New sources must be in compliance upon initial start-up. Existing sources must be in compliance no later than August 18, 1998. The following table highlights the definitions of Group 1 and Group 2 vents.
The storage vessel requirements of this rule are that Group 1 vessels be equipped with either an internal floating-roof (IFR) with a liquid mounted seal, a mechanical shoe seal, or a vapor mounted primary seal with a secondary seal, an external floating-roof (EFR) with double seals, an EFR converted to an IFR, or a closed vent system routed to a control device which reduces HAP emissions by 95% or to 20 ppmv. Group 2 vessels do not need any controls. Applicability requirements for existing and new Group 1 sources are shown below. Group 2 storage vessels are all storage vessels that are not Group 1 vessels.
Compliance with the storage vessel provisions depends on the type of tank. Modifying existing internal or external floating-roof tanks to add secondary seals should be done during the next degassing and cleaning activity occurring after August 18, 1998 or within 10 years, whichever comes first. Existing fixed-roof tanks need to be in compliance within 3 years of the date of promulgation. Any new tank must be in compliance at the time operation begins.
The wastewater provisions define Group 1 wastewater streams as those subject to control requirements under NESHAPS 40 CFR 61 Subpart FF (54 FR 3072-3105) January 7, 1993. The wastewater provisions specified in the refinery MACT do not impose any additional control requirements for these streams. Control requirements for refinery wastewater sources are those required by Subpart FF. Group 2 streams are wastewater streams that are not Group 1 streams.
If the HAP content of products from a process unit is 5% by weight, then an equipment leak program is required. Existing sources are allowed to choose between complying with equipment leak provisions in 40 CFR 60 Subpart VV or with a modified negotiated regulation for equipment leaks as found in 40 CFR 63 Subpart H. For refineries, the leak definition levels are less stringent than those found in 40 CFR 63 Subpart H. New sources must comply with the modified negotiated regulation at the time of start-up. Under either of the two options, within 3 years after promulgation of this rule (August 18, 1998), existing refineries will be required to implement a Leak Detection and Repair (LDAR) program. The refinery has the option to use the leak definition and frequencies as specified in 40 CFR 60 Subpart VV or in Phase I of the modified negotiated regulations as specified in 40 CFR 63 Subpart H. If a refinery chooses to implement the modified negotiated regulations, it must begin using the Phase II leak definitions and frequencies at the end of the fourth year (not later than August 18, 1999), and comply with Phase III requirements within 5 1/2 years (by February 18, 2001). Compared to 40 CFR 60 Subpart VV, the Phase II and III programs have lower leak definition levels for valves and pumps but allow less frequent monitoring if no leaks are detected.
Marine tank vessel loading operations at refineries are required to comply with the marine tank vessel loading NESHAPS 40 CFR 63 Subpart Y unless they are included in an emission average. Gasoline loading racks at refineries are required to comply with 40 CFR 63 Subpart R unless they are included in an emission average.
Compliance for some existing Group 1 sources can also be shown with emissions averaging among existing miscellaneous process vents, storage tanks, wastewater streams, marine tank vessel loading operations, and gasoline loading racks. The emission averaging requirements are the same as those in the hazardous organic NESHAPS (HON) rule in 40 CFR 63 Subpart G. Under the emission averaging rule, so-called credits and debits are established from existing Group 1 and Group 2 sources. Credits are given to Group 1 sources that are controlled to a greater extent than the required reference control technology or to controlled Group 2 sources. Debits are given to Group 1 sources that are controlled less than the standard requires. Only Group 1 sources that are controlled by a technology that has a higher nominal efficiency than the reference control technology are allowed to be used as credits for the emissions average. However, all controlled Group 2 sources are allowed. The final rule allows that up to 20 emission points at a site (or 25 points if pollution prevention measures are used to control some points) can be used in the emissions averaging. All other emission points not included in the emission averaging must be controlled as specified in this rule. To show compliance, the sum of the annual credits must be greater than or equal to the annual debits. Credits and debits are calculated each quarter. Debits in a quarter can be 1.30 times the credits for the same period, as long as the credits are greater than or equal to debits on an annual basis.
Reports of anticipated and actual start-up, shutdown, and malfunction periods are required. Notification of process changes that affect the compliance status of process vents, requests for extensions of repairs, and notification of inspections for storage vessels and wastewater streams may be required as well. A "notification of compliance status" report is due within 150 days after the compliance date. This report should demonstrate that compliance has been achieved for all Group 1 emission points and all emission points included in emission averaging. In addition, periodic reports are required semiannually. Examples of items that need to be included in the periodic reports include any performance tests conducted during the reporting period. Quarterly reports are required for all emission points included in emission averaging. These reports are to include credit and debit calculation results for each month and the quarter. If an emission average is used to show compliance, an Implementation Plan must be submitted no later than 18 months prior to the compliance date. The final rule requires petroleum refineries to maintain records for a period of at least 5 years. These records include all monitoring, inspection, and reporting data and performance test results. Records of all information required to calculate emission credits and debits if emissions averaging is used to show compliance and the information used to make the determination of Group 1 and 2 sources need to be kept as well.
If you would like help in determining the applicability of the refinery MACT to sources at your plant site or if you have any other questions, please call Doug Price, P.E. at 512-255-9999 or email Doug Price. We can also help with the Marine Tank Loading Vessel MACT, Gasoline Loading Operations MACT, and HON (for SOCMI process units located at a refinery). (Prepared September 8, 1995)
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