In a litmus test on the costs to utility consumers for natural gas lost through leaky distribution pipeline systems and other sources, Massachusetts consumers paid as much as $1.5 billion more in the last decade just for the leaks, a congressional study has found.

Completed by the House Natural Resources Committee at the request of Massachusetts’ Edward Markey, former House member and now Democratic senator, the study loosely extrapolated the Massachusetts data to estimate that at least $20 billion in gas was lost nationally between 2000 and 2011.

The study said the problem is most acute in states like Massachusetts, where gas pipeline systems are older. Industry and other sources have been looking at and criticizing various attempts to get a handle on the amounts of pipeline natural gas and naturally occurring methane that are vented into the atmosphere regularly. The quest is trying to estimate the impact on greenhouse gas (GHG) emissions and on the pocketbooks of utility consumers.

Lost gas through pipeline leaks is one part of a larger gas utility accounting called “lost and unaccounted for” (LAUF) gas, broadly defined as the difference between total supplies injected into a given distribution system and the collective measured gas use of all the customers on the system, Ken Costello, principal researcher at the National Regulatory Research Institute (NRRI), said in a report in June. Besides pipeline leaks, LAUF includes measurement/accounting errors and stolen gas. “State [regulatory] commissions can expect a margin of error in any calculation,” Costello said. “They should therefore view a utility’s measure of LAUF gas as an estimate rather than an absolute number.”

In June, researchers at Colorado State University (CSU) began to collect data from possible fugitive methane emissions sources in natural gas transmission systems in an effort to quantify the amount of GHG that is escaping. Pipelines, compressor stations and underground storage facilities are to be examined nationwide by researchers led by CSU’s Engines and Energy Conversion Lab. Earlier this year, the Environmental Defense Fund (EDF) and West Virginia University formed a partnership with eight companies and organizations to study fugitive emissions of methane associated with the routine operation of natural gas fleet vehicles fueled by compressed or liquefied natural gas.

Previous to the congressional study of Massachusetts was one by the City of Boston by Duke and Boston universities, which concluded that the city’s aging pipeline system is widely pockmarked with leaks (see NGI, Nov. 26, 2012).

Economic impacts from leaks have drawn more attention as an offshoot of the heightened interest in pipeline safety following a series of fatal accidents, including a Pacific Gas and Electric Co. transmission pipeline rupture and explosion in September 2010 (see NGI, Sept. 13, 2010).

American Gas Association CEO Dave McCurdy in reaction to the congressional study said “now is the time to accelerate [pipeline] replacement programs.” In response to an inquiry from NGI, McCurdy also commented on the reported extensiveness of the problem as looked at by the federal Energy Information Administration (EIA) and others.

“According to EIA data, less than 1.5 % of natural gas is emitted as it travels from where it is produced to your home. Natural gas utilities are committed to lowering this number even further by continually upgrading and modernizing the natural gas pipeline network. The top priority for natural gas utilities is safety and according to the U.S. Pipeline and Hazardous Materials Safety Administration, our domestic abundance of clean natural gas is delivered via the safest energy delivery system in the nation.”

Markey has said that leaky pipelines put “a hole in consumers’ pockets,” and he is sponsoring legislation that would make it easier for gas utilities to obtain rate coverage for more aggressive investment in repairing or replacing old pipelines. Several bills addressing the issue are moving through the Massachusetts state legislature, with at least one said to allow utilities to more quickly recover the repair or replacement costs.