Options Suggested at GHG NSPS Listening Sessions for EGU NSPS (The Agency is pleased at the wide 

range of constructive suggestions made by stakeholders and is evaluating the full range of options it 

heard from Stakeholders)

EPA held five listening sessions on the GHG NSPS between February 4, 2011 and March 4, 2011. The 

purpose of these listening sessions was for EPA to obtain stakeholder views on the design of section 

111 performance standards to reduce greenhouse gas (GHG) emissions from power plants and 

refineries. EPA is considering the information provided at these listening sessions as it develops the 

proposed EGU NSPS rules.

In the listening sessions, we received comment on a wide range of ideas. Participants offered multiple 

suggestions on how standards could be set for new and existing units, and for existing standards 

suggested a number of mechanisms to use. Note that there was broad support for the format of the 

standards being output based (e.g. pounds of GHG per KW produced). We have provided additional 

information on options heard at the listening sessions to provide context on how ideas like those 

suggested have been incorporated in previous NSPS actions. 

As we continue to evaluate options for controlling GHGs, we are open to suggestions of additional 

options. We believe that the suggestions made during the listening sessions provide a wide range of 

options for inclusion in the SBREFA panel discussion.

New Source Standards:

Under 111(b), these standards reflect the degree of emission limitation achievable through application 

of the best system of emission reduction which, taking into consideration the cost of achieving such 

reduction, any non-air quality health and environmental impact, and energy requirements, the 

Administrator determines has been adequately demonstrated. In general, options that may be

possible under 111(b) include, but are not limited to, the following major alternatives. EPA is interested 

in discussion of the advantages and disadvantages of each of these alternatives, including discussion of 

whether any of these could be combined in a useful way.

Potential Options:

1. Fuel and technology specific efficiency standards based on existing technologies – such a 

standard would likely look at coal based technologies currently being built such as ultrasupercritical plants and IGCCs. While EPA has issued NSPS regulations that are technology and 

fuel specific, in recent power sector NSPS actions, the agency has been moving more towards 

fuel neutral standards.

2. Standards more aggressive than those based on highly efficient coal powered units – such 

standards could consider technologies such as CCS and/or co-firing of lower CO2 fuels. Such 

standards could potentially include emission rate averaging with certain other categories of 

sources. For instance, offsets could be obtained from:

a. Existing units that perform better than the existing source standard, or
b. Units that generate electricity but are not subject to the EGU NSPS (for instance 

industrial units with on-site generation and co-generation). 

Previous NSPS rulemakings have been based on technologies demonstrated in the field (e.g. in 

the past when both scrubbers and SCRs were not nearly as prevalent on the coal-fired fleet, 

NSPS limits were based on the performance of such technologies). 

3. Fuel neutral standards – rather than setting limits based purely on technology, set standards 

based on use of lower GHG fuels – for instance, gas-fired boilers. Recent power sector NSPS 

actions have moved more towards fuel neutral approaches.

4. Phased approach – set a standard based on option #1 that applies immediately and also requires

a tighter standard based on option #2 or #3 after several years. 

Existing Source Standards

For existing sources under CAA 111(d), EPA establishes emission guidelines for sources that emit 

pollutants not regulated under certain provisions of the CAA, and to which an NSPS would apply if such 

existing source were a new source. This is the authority that would be used to establish standards for 

existing sources. These guidelines go through notice and comment. States then promulgate plans that 

establish standards of performance that are consistent with these emission guidelines. Historically, key 

elements of emission guidelines include a description of a system of emission reductions that EPA 

deems adequately demonstrated, the degree of emission limitation achievable, costs, and 

environmental impacts of application, the time required to implement, and other information EPA 

determines is necessary to facilitate formation of State Plans. Different guidelines or compliance times 

(or both) may be specified for different sizes, types, and classes of designated facilities when costs, 

physical limitations, geographical location, or other factors make subcategorization appropriate. (See 40 

CFR 60, Subpart B, “Adoption and Submittal of State Plans for Designated Facilities.”) In developing 

standards for existing sources, we are considering both the structure of possible emissions limits, as well 

as implementation mechanisms.

Potential Options:

1. Base guidelines on efficiency improvements of the existing fleet –such an approach would likely 

involve reductions on the order of 5%, based on the performance of best units within subclasses of boiler types (see: Available and Emerging Technologies for Reducing Greenhouse Gas 

Emissions from Coal-Fired Electric Generating Units, USEPA, October 2010 

(http://www.epa.gov/nsr/ghgdocs/electricgeneration.pdf) and Improving the Efficiency of Coalfired Power Plants for Near Term Greenhouse Gas Emission Reductions, NETL, April 16, 2010 

(http://www.circleofblue.org/waternews/wp-content/uploads/2011/03/DOE-NETL-Coal-firedenergy-efficiency.pdf) The approach of basing standards on best performing technology is 

consistent with the way many NSPS have been set.

2. Set more aggressive guidelines that would include not only efficiency improvements, but also 

replacement of some older generation.

a. Could be based on remaining useful life considerations (e.g., when a unit reached a 

certain age such as 50 years, it would be required to meet tighter standards such as the 

new source standards). 
b. Could be based on some form of a system-wide generation performance standard that 

would gradually decrease as there was fleet turnover. Both the municipal waste 

combustor NSPS and the Clean Air Mercury Rule (CAMR) incorporated flexibility 

mechanisms that allowed averaging across facilities for compliance. While CAMR was 

overturned by the DC Circuit, the court never ruled on this specific issue.

3. Phased approach – establish guidelines based on option #1 at the beginning of the program and 

then require a tighter standard based on option #2 after several years. A phased approach was 

used in CAMR and the court never ruled on this issue.

Implementation Mechanisms – In order to achieve the above limits, different implementation 

mechanisms may be used. In the listening sessions, many participants suggested that States should 

have flexibility to use a wide range of mechanisms to achieve reductions. In addition to the approaches 

discussed above, EPA is considering both the legal and policy implications of allowing States to use 

mechanisms to meet the 111(d) standards that differ from the mechanism (or mechanisms) considered 

in the guidelines. Such an approach would require EPA to set forth criteria (such as an emission rate 

target or a comparison of projected emissions under an approach laid out in the emission guidelines and 

the emissions under an alternative approach being considered by the State). Options that participants 

proposed included:

1. Averaging with tradable credits – Units would be given emission rate targets, if they emitted 

below those targets, they would generate credits for each MWh they generated. If they emitted 

above those targets, they would still be able to comply if they obtained credits to offset 

emissions above the target. Such an approach would only include units covered by the EGU 

NSPS. (As was noted above, averaging type approaches have been used in both the municipal 

waste combustor NSPS and CAMR.)

2. Generation performance standard – similar to approach #1, but would include all generating 

sources (e.g. renewables, nuclear, etc.).

3. Recognition of regional programs such as RGGI in 111(d) implementation. CAMR allowed the 

use of regional programs.

4. Intrastate programs with GHG limitations.

5. Other programs that impact a State’s generation mix and could lead to reductions in emissions 

from covered sources such as renewable portfolio standards or clean energy standards.