Trinity Consultants

Enhanced LDAR in the chemical industry

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Courtesy of Courtesy of Trinity Consultants

As a result of recent leak detection and repair (LDAR) audits and the associated issues (as described in the Winter 2009 issue of Environmental Quarterly), EPA is initiating enhanced LDAR programs as part of the most recent consent decrees.1 The enhanced LDAR programs for chemical facilities are more stringent than the enhanced LDAR previously required for the petroleum refining industry. Starting in 2000, refineries were Blue Valves_EQWebrequired by consent decrees to implement enhanced LDAR programs. Although enhanced LDAR programs include many elements, three main elements of the refinery enhanced LDAR are as follows:

  • Leak definitions were lowered from NSPS VV levels (e.g., 10,000 ppm) to HON levels (e.g., 500 ppm)
  • Initial attempts at repair were required at concentrations as low as 200 ppm (not a “leak” but a lowered action level)
  • Periodic internal/third party audits were required 2

Recent consent decrees in the chemical industry are also requiring enhanced LDAR standards, similar to refinery enhanced LDAR with variations as well as additional requirements. The chemical industry enhanced LDAR programs also lowered the leak definitions, required annual audits, and required replacement or repacking at lower concentrations during maintenance turnarounds. Other elements of the chemical industry enhanced LDAR requirements include the following:

  • Certain technologies are required for repair of leaking valves and connectors
  • Closure devices associated with open-ended lines must be monitored via Method 21 on a periodic basis
  • More stringent delay of repair provisions were included
  • Frequent periodic monitoring of certain valves, connectors, pumps, and agitators is required

Enhanced LDAR: Lower Leak Definitions
Similar to the enhanced LDAR programs for refineries, the leak definitions were lowered as follows:

  • Pumps - lowered from HON (e.g., 1,000 ppm) and Pharma MACT (e.g., 2,000 ppm) levels to 500 ppm
  • Agitators - lowered from HON/Pharma MACT levels (e.g., 10,000 ppm) to 2,000 ppm - 500 ppm
  • All other components - lowered from 500 ppm to 250 ppm, even lower than the refinery enhanced LDAR leak definitions

Enhanced LDAR: Open-Ended Lines
As discussed above, LDAR regulations do not include leak definitions for open-ended lines. However, a new enhanced LDAR provision (not included in the refinery enhanced LDAR programs) is the requirement to conduct periodic monitoring (e.g. quarterly) via Method 21 monitoring on closure devices (i.e., plug, blind flange, cap, or second valve). Under some enhanced LDAR requirements, open-ended lines have a leak definition of 250 ppm.

Enhanced LDAR: Periodic Monitoring
Under the enhanced LDAR programs, EPA is requiring that Method 21 monitoring be conducted on specific periodic frequencies, excluding less frequent monitoring options under the MACT standards. Valves in gas/vapor service and in light liquid service must be monitored quarterly for the first two years, with no regard for good performance, as allowed under MACT standards. Depending on the MACT standard and the number of leaking components, good performance may allow valves to be monitored semiannually, annually, or biannually.

For connectors in gas/vapor service and in light liquid service, monitoring may be required semiannually with no regard for good performance for the first two years. This enhanced LDAR requirement is more stringent than the MACT standards. Depending on the MACT standard and the number of leaking components, connector monitoring may range from annually to once every eight years.

For Pharma MACT facilities, pumps in light liquid service and agitators in gas/vapor service and in light liquid service may be required to be monitored monthly by enhanced LDAR, which is more stringent than MACT-related quarterly monitoring.

Enhanced LDAR: Valves in Gas/Vapor Service and in Light Liquid Service
As another example of the increased stringency of enhanced LDAR in the chemical industry as compared to the initial refining enhanced LDAR requirements, the enhanced LDAR requirements for the chemical industry require more technology and capital improvements. For example, new valves in gas/vapor service and in light liquid service added to process units must be “certified low-leaking valves” or fitted with “certified low-leaking valve packing technology.”

Additionally, some enhanced LDAR programs require that leaking valves must be either replaced or repacked with certified low-leaking valves or valve packing within 30 days of discovery, unless the replacement requires a process unit shutdown. If the valves also meet the leak definitions under the MACT standards, then the repairs must be completed within 15 days.

Valves with an instrument reading between 100 ppm and 250 ppm must be maintained in a list for potential repair during the next process unit shutdown. Those found to be leaking more often should have a higher priority for repacking/replacement with leakless technology. The determination may be based on a calculation to determine how many valves would need to replaced, which considers the number of total valves, valves on delay of repair, and valves that have already been repacked or replaced with low-leaking valve or technology.

Some enhanced LDAR programs also allow facilities to take credit for replacing regular valves with leak-less valves. However, the elimination of regular valves must be for the purpose of reducing hazardous air pollutant (HAP) emissions. If the regular valves would be removed from service due to operational/process changes, facilities are not allowed to utilize the credit.

Enhanced LDAR: Connectors in Gas/Vapor Service and in Light Liquid Service
Enhanced LDAR requirements also include connector replacement and improvement provisions as follows:

  • Flanged – replacement or improvement of the gasket
  • Threaded – replacement of the connector
  • Compression – replacement of the connector
  • CamLock – replacement of the gasket
  • Quick Connect – replacement of the gasket or replace connector, as applicable
  • Any type – eliminate by either pipe replacement or welding, etc.

Additionally, enhanced LDAR programs are to include provisions so that new connectors added to a facility should be those that will least likely leak based on best engineering judgment.

Enhanced LDAR: Delay of Repair
Similar to refinery consent decrees, a valve cannot be put on delay of repair until “drill and tap” is utilized at least twice. Under the enhanced LDAR, delay of repair requires sign-off from the relevant process unit supervisor, as is required under NSPS VV but not under the MACT standards. In some cases, sign-off may be required by the plant manager or a corporate official responsible for environmental compliance or plant engineering management.

EPA will continue to conduct LDAR audits and require enhanced LDAR in the chemical industry, as applicable. As emphasized in our previous article on this topic, EPA, especially Region V, will focus on Miscellaneous Organic NESHAP (MON) facilities in 2010; therefore, chemical sectors that have not been affected thus far should consider the lessons learned from the refining and chemical sectors that have already been affected.

1 Please note that not all chemical facilities that received LDAR-related consent decrees have been required to initiate an enhanced LDAR program.

2 The frequency of third party audit requrements varies; it could be annual, biennial, every 5 years, etc.

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