EPA Sets Final Rule for GHG Measurement of Compressors and other Equipment, Mandates PCB Removal

December 2010 Vol. 237 No. 12

The EPA made several concessions to the natural gas industry in its final greenhouse gas (GHG) monitoring and reporting rule which the agency published at the end of October. The so-called “Subpart W” rule – 288 pages of complex technical language and charts – lays out the equipment in various natural gas and petroleum sectors which must be monitored for a group of GHGs, and prescribes the methods for that monitoring.

The requirement kicks in Jan. 1, except that for calendar 2011, pipelines and other gas sectors can use what is called best available monitoring methods (BAMM) when “it is not reasonably feasible to acquire, install, or operate a required piece of monitoring equipment in a facility, or to procure measurement services from necessary providers.” Best available monitoring methods are any of the following methods: monitoring methods used by the facility that do not meet the specifications of a relevant subpart; supplier data; engineering calculations; other company records.

The EPA issued a proposed rule last April which made improvements on an earlier version. The final rule, which was scheduled to appear in the Federal Register last month, goes even further than the July proposal to meet improvements requested by INGAA, which had submitted a detailed, laundry list of changes it wanted made to the April proposed rule.

Whether it goes far enough is not clear. INGAA officials were unable to comment. Among INGAA’s biggest concerns has been measurement of GHG emissions from reciprocating compressor rod packing vents. The EPA had been pressing for annual “three-mode” testing (i.e., measurements during each operational mode that occurs during a reporting period): operating; standby pressurized; and not operating, depressurized.

In the final rule the EPA backed off that position and clarified that companies can conduct an annual measurement of each compressor in the mode as it exists at the time the annual measurement is taken. But each compressor must be measured at least once during every three-year period in the “not operating and depressurized” mode without blind flanges in place. Blind flanges are flat plates inserted between flanges on a valve or piping connection to ensure absolute isolation of the equipment from process fluids, and hence, compromise through valve leakage measurement. Isolation valve leakage through the compressor blow down vent, when the compressor is in the not operating and depressurized mode, must be measured before blind flanges are installed.

Besides reciprocating compressor rod packing vents, transmission pipelines will be required to measure emissions from pneumatic device venting, blow down vent stacks, storage tanks, centrifugal compressor venting, and other emissions from equipment. The rule applies to those that emit GHGs greater than or equal to 25,000 metric tons of CO-2 equivalent per year. The rule requires annual reporting of GHGs including carbon dioxide (CO-2), methane (CH-4), nitrous oxide (N2O), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), sulfur hexafluoride (SF6), and other fluorinated compounds (e.g., hydrofluoroethers (HFEs).

The final rule appears to make many concessions. It clarifies that emissions from centrifugal and reciprocating compressors do not require the installation of a permanent flow meter; use of a portable meter and port are acceptable. In addition, through-valve leakage to open-ended vents, such as unit isolation valves on non-operating depressurized compressors and blow down valves on pressurized compressors, may be measured using acoustic leak detection devices. In addition, compressor throughput flow meters are not required; estimates of compressor flow will be sufficient for EPA’s requirements.

INGAA had voiced concerns about potential unsafe conditions to employees created by some of the GHG measurement requirements. In that vein, the EPA allowed for alternatives to an optical gas imaging instrument for detecting GHG emissions from equipment leaks. Those could include organic vapor analyzers (OVA), toxic vapor analyzers (TVA) and infrared laser beam illuminated instruments as alternative technologies to the optical gas imaging instruments proposed for emissions detection.

EPA-Mandated PCB Removal Could Cost Billions
The EPA may require pipelines to severely reduce the presence of polychlorinated biphenyls (PCBs) throughout their systems, a move which would cost the industry tens, and potentially hundreds, of billions of dollars, according to the American Gas Association. Pamela F. Faggert, vice president and chief environmental officer, Dominion Resources Services, Inc., says the new regulatory measures the EPA is considering could cost her company alone a minimum of $300 million.

Patricia Kablach Casano, government affairs counsel for corporate environmental programs at General Electric, filed 80-pages of technical comments on Oct. 18 disputing the EPA’s concerns about human health concerns arising from PCB exposure, concerns highlighted in the EPA advance notice of proposed rulemaking (ANPRM) issued last April. The INGAA and AGA signed the GE comments. Casano argues that PCBs are not the cancer threat they once were thought to be, that pipelines have been reducing the amount of PCBs in their systems and that there is no indication that PCB exposure associated with leaking pipeline fluids poses an unreasonable threat to human health.

Minute amounts of PCBs were introduced into pipelines 40-50 years ago as fire retardants in the liquid hydraulic fluid or lubricating oil in pipeline compressors, as valve grease, or as a fogging agents in local distribution mains. PCB use was banned by the Toxic Substances Control Act in the mid 1970s out of concern that the chemical caused cancer in humans. PCBs already in pipelines were allowed to remain, subject to restrictions, which changed over the years. In 1984 and later in 1998, when it finalized what is called its Mega Rule, the EPA acknowledged that PCBs in pipelines posed a reasonable risk since pipelines are closed systems, and opportunities for leaks of PCBs are minimal. The Mega Rule, which included provisions applicable to all industries, allowed pipelines and compressors to have PCB concentrations below 50 parts per million (ppm) under the terms of a “use exemption.” Concentrations above that threshold were also allowed provided the operator follows applicable management practices and approved characterization and disposal practices.

The EPA’s ability, in a legal sense, to change the 1998 Mega Rule depends on its ability to reverse its 1998 “no unreasonable risk” assessment. John Smith, a chemist in the EPA’s fibers and organics branch, who is leading the PCB rulemaking, argues the agency can do that simply by determining its action is “less than arbitrary.”

James Rower, executive director of the Utility Solid Waste Activities Group, says the EPA must have “substantial evidence” to reverse its 1998 use exemption. Natural gas transportation associations, which are part of Rower’s group, agree with that position.

“INGAA strongly opposes narrowing or eliminating this use authorization, and believes it is not necessary to do so to protect the public health,” says Lisa Beal, director, environment and construction policy, INGAA. “Despite the substantial measures taken by the natural gas pipeline industry to manage residual PCBs in certain natural gas pipelines, it is impossible to remove all PCBs from the entire transmission system to the standards proposed by the EPA in the ANPRM.”

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