American Oil and Gas Reporter - January 2015 - 222

that this regulatory proposal will not
change the scope of the regulation."
Legal Analysis
Citing case law and policy, the associations also hold that the proposal ignores
both the CWA's legislative limit on jurisdiction as well as pertinent U.S. Supreme
Court interpretations.
The term "significant nexus" is a legal
term being applied broadly to existing
scientific analyses, and yields an unlawful
regulatory definition, the associations insist. Moreover, they continue, layering
definitions relative to adjacent waters,
including neighboring, riparian areas and
flood plains, demonstrates the need for
careful analyses that already have been
exhibited in best professional judgment
practices.
The term wetlands is unlawfully designed to expand CWA jurisdiction beyond
its scope, and the proposed WOTUS definition will not promote the administrative
efficiency that the agencies claim, the
associations assert. The expanded definition also fails to acknowledge states'
jurisdiction as exemplified in groundwater
regulation, and allocation of water quantity
will be limited significantly if it is implemented, the comments indicate. They
also suggest that the agencies' failure to
address grandfathering of pending and
existing CWA authorizations and interpretations is unlawful, and will prompt
citizen-based litigation.
The proposed WOTUS definition purports to follow the guidance of Supreme
Court Justice Anthony Kennedy's concurrence in Rapanos v. U.S. by creating
an "other waters" category that will be
analyzed on a case-specific basis, the associations note. Even so, they continue,
the dilemma the agencies identify does
not warrant a new definition. According
to the comments, the agencies' proposal
misconstrues many aspects of Kennedy's
"significant nexus" standard, ignores a
plurality opinion in the case, and asserts
broad jurisdiction over other waters that
have not been classified previously as jurisdictional under the CWA or under U.S.
Supreme Court case law.
Ultimately, the associations conclude,
the proposed rule making:
* Fails to acknowledge the significant
administrative burden it will impose on
the federal and state regulatory agencies
and the regulated community;
* Represents a significant departure
from the existing regulatory definition
and program; and
* Falls drastically short of adequately
presenting or assessing its economic and
energy production impacts.
Ì

Only A Small Fraction Of Wells
Leaking Methane, Study Says
AUSTIN, TX.-A small number of
natural gas wells are responsible for the
majority of methane emissions at natural
gas production sites. Researchers assert
the emissions come from two major
sources-liquid unloadings and pneumatic
controller equipment.
The studies say 19 percent of the
pneumatic devices account for 95 percent
of emissions from those devices, while
20 percent of the wells with unloading
emissions that vent to the atmosphere
account for 65-83 percent of those emissions. The reports, Methane Emissions
from Process Equipment at Natural Gas
Productions Sites in the United States:
Liquid Unloadings, and Methane Emissions from Process Equipment at Natural
Gas Productions Sites in the United
States: Pneumatic Controllers, were written by researchers from the Cockrell
School of Engineering at the University
of Texas at Austin and environmental
testing firm URS.
"To put that in perspective, over the
past several decades, 10 percent of the
cars on the road have been responsible
for the majority of automotive exhaust
pollution," says David Allen, chemical
engineering professor at the Cockrell
School and principal investigator for the
study. "Similarly, a small group of sources
within these two categories are responsible
for the vast majority of pneumatic and
unloading emissions at natural gas sites."
The studies, published Dec. 9 in Environmental Science & Technology, are
the second phase of the team's 2013
study that included some of the first
measurements for methane emissions
taken at hydraulically fractured wells.
Both phases of the studies involve a partnership between participating energy companies, the Environmental Defense Fund,
an independent scientific advisory panel
and the UT Austin research team.
Pneumatic Devices
According to the Environmental Protection Agency, pneumatic devices are
estimated to be among the larger sources
of methane emissions in the natural gas
supply chain. The agency says that 477,606
gas-actuated devices are in use at production sites across the United States.
The agency says it estimates the devices
emit 17.4 billion cubic feet a year of
methane. It adds that number is based on
relatively limited measurements, and
newer field measurements indicate those

222 THE AMERICAN OIL & GAS REPORTER

emissions could be understated, but points
out many of the surveys took place at
wells which had just been hydraulically
fractured. The EPA says those wells tend
to have higher liquid production rates,
and therefore may have more frequent
actuation of controllers than the average
U.S well.
The pneumatic devices study confirmed
regional differences in methane emissions
researchers first reported in 2013, with
the highest amounts of emissions in the
Gulf Coast and lowest in the Rocky
Mountains. It says some of the regional
differences could be attributed to differences in installed controller types (continuous versus intermittent vents).
"Our team's previous work established
that pneumatics are a major contributor
to emissions," Allen says. "Our goal here
was to measure a more diverse population
of wells to characterize the features of
high-emitting pneumatic controllers."
The research team measured emissions
from 377 gas-actuated controllers at gas
and oil production sites, sampling all
identifiable controller devices at each
well site. According to the study, the average methane emission from each controller studied was 17 percent higher than
the average emissions reported in a 2012
EPA greenhouse gas study.
The UT researchers point out the average from their study is dominated by a
small subpopulation of the controllers-
19 percent of the controllers with measured
emission rates in excess of six standard
cubic feet an hour accounted for 95
percent of emissions. More than half of
the controllers recorded emissions of
0.001 standard cubic feet an hour or less
during 15 minutes of measurement, the
study says, with 62 percent having an
emissions rate of less than 0.001 standard
cubic feet an hour.
The high-emitting pneumatics are a
combination of devices that are not operating as designed, are used in applications
that cause them to release gas frequently,
or are designed to emit continuously at
high rates, the study describes.
Liquid Unloadings
According to EPA, out of 470,913
natural gas wells in the United States,
60,810 undergo liquids unloading, which
clear wells of accumulated liquids to increase production. After observing variable
emission rates for the technique for a
limited group of well types in the 2013

American Oil and Gas Reporter - January 2015

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