The Environmental Protection Agency's (EPA) proposed rule out last week to regulate greenhouse gas (GHG) emissions under the New Source Review provisions of the Clean Air Act targets large emitters -- including power plants -- but spares smaller facilities.

Large industrial facilities -- including power plants, refineries and factories -- that emit at least 25,000 tons of GHG per year would be required to obtain construction and operating permits covering these emissions, under the proposed rule. (Provisions are highlighted in a fact sheet.) The permits must demonstrate the use of best-available control technologies and energy efficiency measures to minimize GHG emissions when facilities are constructed or significantly modified.

"By using the power and authority of the Clean Air Act, we can begin reducing emissions from the nation's largest greenhouse gas emitting facilities without placing an undue burden on the businesses that make up the vast majority of our economy," said EPA Administrator Lisa P. Jackson. "This is a common sense rule that is carefully tailored to apply to only the largest sources -- those from sectors responsible for nearly 70% of U.S. greenhouse gas emissions sources. This rule allows us to do what the Clean Air Act does best -- reduce emissions for better health, drive technology innovation for a better economy and protect the environment for a better future -- all without placing an undue burden on the businesses that make up the better part of our economy."Farms, restaurants and many other types of small facilities would not be included in the regulation, EPA said.

The move by EPA comes just as a bill to limit GHGs has emerged in the U.S. Senate (see related story). The legislation is said to be more favorable to business interests than earlier legislation that passed in the House. The general opinion among energy and other interests is that action by lawmakers is preferable to having GHGs regulated by EPA under the Clean Air Act.

An earlier draft plan to limit GHG emissions was seen by analysts as potentially affecting 13,000 large industrial sources (see NGI, Sept. 7).

Under the Clean Air Act, EPA is required to regulate sources that produce more than a specific threshold of certain pollutants, which include nitrogen oxide, ozone, carbon monoxide, particulates and lead. The U.S. Supreme Court in 2007 unanimously ruled that the EPA erred when it rejected a request to initiate a rulemaking to regulate GHG emissions (see NGI, April 9, 2007). In response EPA this year published a proposed endangerment finding declaring six gases -- carbon dioxide (CO2), methane, nitrous oxide, hydroflurocarbons, perflurocarbons and sulfur hexafluoride -- as GHG contributors (see NGI, April 20).

According to EPA, if a proposed fuel-economy rule to regulate GHGs from cars and trucks is finalized and takes effect in spring 2010, Clean Air Act permits would automatically be required for stationary sources emitting GHGs. This proposed rule focuses these permitting programs on the largest facilities, responsible for nearly 70% of U.S. stationary source GHG emissions.

With the proposed emissions thresholds, EPA estimates that 400 new sources and modifications to existing sources would be subject to review each year for GHG emissions. In total, approximately 14,000 large sources would need to obtain operating permits that include GHG emissions. Most of these sources are already subject to clean air permitting requirements because they emit other pollutants.

The proposed tailoring rule addresses a group of six greenhouse gases: CO2, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons and sulfur hexafluoride.

EPA is proposing carbon dioxide equivalent (CO2e) as the preferred metric for determining GHG emissions for any combination of the six GHGs. "Emissions of greenhouse gases are typically expressed in a common metric so that their impacts can be directly compared as some gases are more potent (have a higher global warming potential or GWP) than others," EPA said. "The international standard practice is to express GHGs in CO2e. Emissions of gases other than CO2 are translated into CO2 equivalents by using the gases' global warming potentials."

In addition, EPA is requesting public comment on its previous interpretation of when certain pollutants, including CO2 and other GHGs, would be covered under the permitting provisions of the Clean Air Act. A different interpretation could mean that large facilities would need to obtain permits prior to the finalization of a rule regulating GHG emissions.

EPA will accept comment on the proposals for 60 days after publication in the Federal Register.

©Copyright 2009 Intelligence Press Inc. All rights reserved. The preceding news report may not be republished or redistributed, in whole or in part, in any form, without prior written consent of Intelligence Press, Inc.