**PRESSURE RELIEF DEVICE LANGUAGE IN AMF_PC_P&R III RULE**

8. Pressure Relief Devices For the AMF, PC and APR MACT standards, we are proposing, as part of our revisions to address
p eriods of SSM in response to the 2008 Sierra Club ruling, to specify that PRD in organic HAP service may not release to the atmosphere. To ensure compliance with this requirement, we are further proposing to require facility owners or operators in these three source categories to employ monitoring capable of (1) immediately alertin g an operato r when there is an

atmospheric release from a PRD in organic HAP service and (2) recording the time and duration of each pressure release. Owners or operators would be required to report any pressure

release and an estimate of the amount of organic HAP released to the atmosphere with the
next periodic report.

We believe that PRD releases that are vented directly to the atmosphere are caused by

m alfunctions. Emissions vented to the atmosphere by PRDs may contain HAP that are

otherwise regulated under the MACT standards. In Sierra Club v. EPA, 551 F.3d 1019 (D.C. Cir. 2008), the court determined that standards under CAA section 112(d) must provide for

compliance at all times. Therefore, the proposed rule revisions provide that a pre ssure release from a PRD in organic HAP service, unless routed to a control device or process, is a violation of the emission standard. As with any malfunction event, an owner or operator may assert an affirmative defense against civil penalties for a malfunction causing a pressure release from a PRD in organic HAP service to the atmosphere.

Pressure release events from PRDs in organic HAP service to the atmosphere have the potential to emit large quantities of HAP. Where a release occurs, it is i mportant to identify and mitigate it as quickly as possible. Therefore, we are proposing to require that sources monitor PRDs in

o rganic HAP service using a device or system that is capable of identifying and recording the time and duration of each pressure release and of notifying operators that a release has occurred. For purposes of estimating the costs of this requirement, we assumed that operators would install electronic indicators on each PRD in organic HAP service that vents to the atmosphere to identify and record the time and duration of each pressure release. However, owners or operators could use a range of methods to satisfy these requirements, including the use of a parameter monitoring system that may already have been in place on the p rocess operating pressure that is sufficient to notify operators immediately that a pressure release is occurring, as well as recording the time and duration of that release.

Based on our cost assumptions that the most expensive approach would be used, th e

n ationwide capital cost of installing these monitors is $37,000, $400,000 and $51,000 for the AMF, APR and PC source categories, respectively. The total annualized cost of installing and operating these monitors is $5,300, $56,000 and $7,200 per year for the AMF, APR and PC source categories, respectively.3. Section 63.1101 is amended by adding in alphabetical order the terms “Affirmative defense,”

“Pressure release,” and “Pressure relief device or valve” to read as follows: **§ 63.1101 Definitions.** Pressure release means the emission of materials resulting from the system pressure being
g reater than the set pressure of the pressure relief device. This release can be one release or a series of releases over a short time period due to a malfunction in the process. Pressure relief device or valve means a safety device used to prevent operating pressures from

exceeding the maximum allowable working pressure of the process equipment. A common pressure relief device is a spring

- loaded pressure relief valve

. Devices that are actuated either by a pressure of less than or equal to 2.5 pounds per square inch gauge or by a vacuum are not pressure relief devices.

**§ 63.1102 Compliance schedule**

**.** (b) All acrylic and modacrylic fiber production affected sources and polycarbonate production

a ffected sources that commenced construction or reconstruction on or before **[INSERT DATE**  **OF PUBLICATION IN THE FEDERAL REGISTER]** , shall be in compliance with the pressure relief d evice monitoring requirements of § 63.11 07(e)(3) upon initial startup or 3 years after the effective date of the final amendments, whichever is later, and the equipment leaks

requirements of 40 CFR part 63, subpart UU upon initial startup or 1 year after the effective date of the final amendments, whichever is later. New acrylic and modacrylic fiber production affected sources and polycarbonate production affected sources that commence construction or reconstruction after **[INSERT DATE OF PUBLICATION IN FEDERAL REGISTER]** , shall be in

compliance with the pressure relief device monitoring requirements of § 63.1107(e)(3) upon initial startup or by the effective date of the final amendments, whichever is later. * * * * *

**§ 63.1107 Equipment leaks.** * * * * * (e) Requirements for pressure relief devices. For acrylicand modacrylic fiber production

a ffected sources and polycarbonate production affected sources, except as specified in paragraph (e)(4) of this section, the owner or operator must comply with the requirements specified in paragraphs (e)(1) and (2) of this section for pressure relief devices in organic HAP gas or vapor service. Except as specified in paragraph (e)(4) of this section, the owner or operator of an acrylic and modacrylic fiber productio n affected source or polycarbonate production affected source must also comply with the requirements specified in paragraph (e)(3) of this section for all pressure relief devices in organic HAP service. (1) Operating requirements. Except during a pressure release event, operate each pressure relief device in organic HAP gas or vapor service with an instrument reading of less than 500 ppm above background as detected by Method 21 of 40 CFR part 60, appendix A. (2) Pressure release requirements. For pressure relief devices in organic HAP gas or vapor service, comply with paragraph (e)(2)(i) or (ii) of this section, as applicable.(i) If the pressure relief device does not consist of or include a rupture disk, conduct instrument monitoring, as detected by Met hod 21 of 40 CFR part 60, appendix A, no later than 5 calendar days after the pressure relief device returns
to organic HAP service following a pressure release to verify that the pressure relief device is operating with an instrument reading of less than 500 ppm above background. After 5 calendar days, an instrument reading of 500 ppm above background or greater is a violation. (ii) If the pressure relief device consists of or includes a rupture disk, install a replacement disk as soon as practicable after a pressure release, but no later than 5 calendar days after the pressure release. The owner or operator must also conduct instrument monitoring, as detected by Method 21 of 40 CFR part 60, appendix A, no later than 5 calendar days a fter the pressure re lief device returns to organic HAP service following a pressure release to ve rify that the pressure relief device is operating with an instrument reading of less than 500 ppm above background. After 5 calendar days, an instrument reading of 500 ppm above background or greater is a violation. (3) Pressure release management. Except as specified in paragraph (e)(4) of this section, the owner or operator must comply with the requirements specified in paragraphs (e)(3)(i) and (ii) of this section for all pre ssure relief devices in organic HAP service. Any pressure release from such a pressure relief device is a violation. (i) The owner or operator must equip each pressure relief device in organic HAP service with a device(s) or parameter monitoring system that is capable of identifying and recording the time and duration of each pressure release and of notifying operators immediately that a pressure release is occurring. Examples of these types of devices and systems include, but are not limited to, a ru pture disk indicator, magnetic sensor, motion detector on the pressure relief valve stem, flow monitor, or pressure monitor. Regardless of the methodology chosen, when the device or monitoring system indicates that a pressure release has occurred, it shall be directly enforceable as a release from the pressure relief device. If this instrument is capable of measuring the concentration of leaks through the pressure relief device, then the owner or operator may use this i nstrument to meet the requirements of paragraph (e)(2) of this section. (ii) If any pressure relief device in organic HAP service releases to atmosphere as a result of a pressure release event, t he owner or operator must calculate the quantity of organic HAP released during each pressure release event and report this quantity as required in paragraph (g) of this section. Calculations may be based on data from the pressure relief device monitoring alone or in combination with process parameter monitoring data and process knowledge. (4) Pressure relief devices routed to a control device or process. If a pressure relief d evice in organic HAP service is designed and operated to route all pressure releases through a closed vent system to a control device or process, the owner or operator is not required to comply with paragraphs (e)(1), (2), or (3) (if applicable) of this section. Both the c l osed vent system and control device (if applicable) must meet the requirements of § 63.1034 of this part.(f) Recordkeeping requirements. For acrylic and modacrylic fiber production affected sources

a nd polycarbonate production affected sources, for pressure relief devices in organic HAP service, keep records of the information specified in paragraphs (f)(1) through (5) of this section, as applicable. (1) A list of identification numbers for pressure relief devices that the owner or operator elects to equip with a closed

-vent system and control device, under the provisions in paragraph (e)(4) of this section. (2) A list of identification numbers for pre ssure relief devices subject to the provisions in paragraph (e)(1) of this section. (3) A list of identification numbers for pressure relief devices equipped with rupture d isks, under the provisions in paragraph (e)(2)(ii) of this section. (4) The dates a nd results of the monitoring following a pressure release for each
p ressure relief device subject to the provisions in paragraph (e)(1) and (2) of this section. The results shall include: (i) The background level measured during each compliance test

. ( ii) The maximum instrument reading measured at each piece of equipment during each compliance test. (5) For pressure relief devices in organic HAP service subject to paragraph (e)(3) of this section, keep records of each pressure release to the atmosphere, including the following information: (i) The source, nature, and cause of the pressure release. (ii) The date, time, and duration of the pressure release. (iii) An estimate of the quantity of total HAP emitted during the pressure release and the calculati ons used for determining this quantity. (iv) The actions taken to prevent this pressure release. (v) The measures adopted to prevent future such pressure releases.

(g) Periodic reports. For owners or operators of an acrylic and modacrylic fiber production

a ffected source or polycarbonate production affected source subject to paragraph (e) of this section, Periodic Reports must include the information specified in paragraphs (g)(1) through (3) of this section for pressure relief devices in organic HAP service. (1) For pressure relief devices in organic HAP service subject to paragraph (e) of this section, report confirmation that all monitoring to show compliance was conducted within the reporting period. (2) For pressure relief devices in organic HAP gas or vapor service subject to paragraph (e)(2) of this section, report any instrument reading of 500 ppm above background or greater, more than 5 days after the relief device returns to organic HAP gas or vapor service after a pressure release. (3) For press ure relief devices in organic HAP service subject to paragraph (e)(3) of this section, report each pressure release to the atmosphere, including the following information: (i) The source, nature, and cause of the pressure release. (ii) The date, time, and duration of the pressure release.(iii) An estimate of the quantity of total HAP emitted during the pressure release and the method used for determining this quantity. (iv) The actions taken to prevent this pressure release. (v) The measures adopted to prevent future such pressure releases.