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/R Incorporated Providing Environmental Technical Support Since 1989

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MEMORANDUM 

DATE: October 20, 2010

SUBJECT: Summary of the October 19, 2010 Teleconference with the Sean Mooney to 

Discuss Leak Detection and Repair (LDAR) Programs at Natural Gas Processing 

Plants

FROM: Bradley Nelson, EC/R, Inc.

TO: Bruce Moore, EPA/OAQPS/SPPD/CCG

1.0 INTRODUCTION

EPA is in the process of reviewing air regulations affecting the oil and natural gas 

industry. This review includes the leak detection and repair (LDAR) requirements for oil and

natural gas production, natural gas processing, natural gas transmission, and natural gas 

distribution. These air regulations include the requirements in the following NSPS and 

NESHAP: The NSPS for Equipment Leaks of VOC from Onshore Natural Gas Processing Plants

(40 CFR part 60, subpart KKK) and the NESHAP From Oil and Natural Gas Production 

Facilities (40 CFR part 63, subpart HH). Sean Mooney, Regional Operations Manager at EMS,

(a contractor LDAR monitoring company) was contacted to discuss the current LDAR practices 

that are currently being performed at gas processing plants.

2.0 SUMMARY OF MEETING

A meeting via teleconference was set up between Sean Mooney of EMS, and Phil 

Norwood and Bradley Nelson of EC/R Inc. The purpose of the meeting was to discuss the 

LDAR programs that are currently being used in the natural gas processing industry. The 

primary topics that were discussed in the teleconference were:

 Compressor requirements for subpart KKK and subpart HH (which refers to §60.482-3, 

§61.242-3);

 Detection of leaks from high methane/low VOC streams;

 Possible use of Method 21 to detect leaks from seals on “bleeding” pneumatic devices.

Mr. Mooney stated that the 90 percent of the facilities that he works with are MACT 

facilities and report using the requirements in 40 CFR part 60, subpart KKK. He stated that that 

the requirements in subpart KKK are more stringent than 40 CFR part 60, subpart VV and 
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requires repairing of leaks greater than 10,000 parts per million (ppmv). He also stated that the 

facilities use EPA Method 21 to determine equipment leaks. EC/R asked if additional equipment 

would need to be monitored if the leak definition was reduced to 500 ppm. Mr. Mooney 

responded that existing gas processing facilities do not have the technology to meet the 500 ppm 

standard. He stated that most of the existing gas processing facilities are old and replacing the 

older equipment with new technology would be very expensive. As an example, Mr. Mooney 

stated that many facilities use positive displacement (PD) pumps in gas processing, which leak a 

stream of the natural gas to allow the pump to cool. The cost of replacing these existing PD 

pumps with new vane pumps, which can meet the 500 ppm standard, would be approximately 

$70,000 per pump. This would primarily be an issue for existing gas processing plants.

The next topic of discussion was the compressor leak requirements. Mr. Mooney stated 

that 90 percent of the compressors used in gas processing plants were installed before January 

20, 1984 and are “grandfathered,” and did not have to meet any requirements in 40 CFR part 63, 

subpart HH. The citation for this clause was found in §63.769(b) which states:

“(b) This section does not apply to ancillary equipment and compressors for which the 

owner or operator is meeting the requirements specified in subpart H of this part; or is 

meeting the requirements specified in 40 CFR part 60, subpart KKK.”

The subpart KKK regulation only applies to facilities that commence construction, 

reconstruction, or modification after January 20, 1984. Mr. Mooney stated that most of the 

compressors that are not “grandfathered” either route the captured emissions from the stuffing 

box to a flare or capture the emissions using a vapor recovery device. He also stated that some 

of the processing plants are replacing their older engine compressor with turbine compressors, 

which do not leak. 

The next topic that was discussed was pneumatic devices. Mr. Mooney stated that field 

gas is used to operate the pneumatic devices in the field, which are used to alleviate natural gas 

processing pressure. He stated that it would be difficult to distinguish the difference between 

leaking of the processed gas and the field gas used to operate the pneumatic device. He also 

stated that these devices are not currently regulated.