The US Environmental Protection Agency, which does not regulate methane emissions from natural gas local distribution companies (LDC), should start working with the US Pipeline & Hazardous Materials Safety Administration to address the problem, EPA’s inspector general’s office said in a July 25 report.
Such pipeline leaks led to the loss of more than $192 million of gas during 2011, a cost that was passed on to consumers, in addition to their potential environmental impacts, according to Erica Hauck, a program manager in the EPA IG office’s Program Evaluation Office.
“Additionally, EPA has not partnered with [PHMSA], which regulates pipeline safety, to control methane leaks; nor has EPA developed a strategy to address barriers that inhibit the mitigation of methane leaks in the natural gas distribution sector,” she said.
EPA already has a voluntary program to address methane leaks across the gas industry, Natural Gas STAR, but its efforts have produced limited results from LDCs, Hauck said. “This is due largely to financial and policy barriers, including disincentives for [LDCs] to repair nonhazardous leaks,” she indicated.
Hauk said investigators also found that uncertainties in EPA’s emissions factors for the gas LDCs raise questions about the accuracy of reported methane emissions. “In our view, effective methane reduction strategies may be difficult to develop without better estimates of methane emissions for this sector,” she said.
In addition to recommending that EPA work with PHMSA to start addressing LDCs’ methane emission from both an environmental and a safety standpoint, the report said EPA should:
• Develop and implement a strategy to address the financial and policy barriers to repairing methane leaks from LDCs’ pipelines.
• Establish annual performance goals for reducing methane emissions from gas distribution pipelines through its voluntary programs, and report annually on the agency’s progress in meeting these goals.
• Annually assess whether performance goals are being met and, if not, determine whether changes are needed, including whether regulating LDC pipelines’ methane emissions would appropriate under the Clean Air Act.
• Review data from existing and ongoing studies to determine whether it can be used to verify and update existing emission factors. “If not, EPA should proactively identify opportunities to work with the research community to obtain the needed data,” Hauck said.
The American Gas Association, which represents LDCs in Washington, said in response to the report that a concerted effort by gas utilities to upgrade and modernize the nation’s local distribution pipeline network to enhance safety has also contributed significantly to a declining trend in emissions from the system.
AGA’s board also approved a set of voluntary measures on June 11—including pipe replacement, installation of low or no-bleed valves in place of high bleed pneumatic devices; enhancement of damage prevention programs; measures for reducing emissions during repair or replacement projects; directed inspection and maintenance programs; and pipeline repair and lining techniques—to help modernize distribution systems and reduce emissions, AGA said.
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