W E S T E R N S T A T E S A I R R E S O U R C E S C O U N C I L

July 18, 2011

Mr. Steve Page, Director

Office of Air Quality Planning and Standards

Office of Air and Radiation

U.S. Environmental Protection Agency

Mail Code: C404-04

Research Triangle Park, NC 27711

Dear Mr. Page,

WESTAR supports an update to the Residential Wood Heater New Source Performance 

Standard (NSPS) and is encouraged that EPA is proceeding with the regulatory process to do so. 

Residential wood combustion is a leading cause of unhealthy levels of fine particulate and air 

toxics and the primary source of non-attainment with the 24 hour PM2.5 NAAQS in airsheds 

throughout the West. Other areas impacted by residential wood smoke are monitoring PM2.5

levels close to the current standard. In addition, the health science has led EPA to lower the 

PM2.5 NAAQS over time and, as you know, EPA is currently considering a more stringent 

standard. 

It has been more than 20 years since EPA revisited the wood heater NSPS and EPA must now 

use this opportunity to make the standards more protective of public health. An essential part of 

EPA’s NSPS evaluation is to make sure that any proposed changes do not result in backsliding of 

public health protection and undermine the credibility of EPA’s wood heater certification 

program. We are writing at this time to urge EPA to put in place a more stringent standard for 

residential wood heaters (wood stoves and fireplace inserts). We understand that almost 90 

percent of the currently certified wood stoves and fireplace inserts would meet a standard 

currently contemplated by EPA. 

The NSPS requires that EPA establish standards on the basis of the “best system of emission 

reduction.” However, the level under consideration by EPA appears to be based primarily on an 

economic analysis which assumes high development costs which are not passed on to consumers 

and not primarily on an assessment of the best technology. Absent a more stringent standard, 

based on the best performing units, there is no incentive for manufacturers to develop heaters 

that will be cleaner burning than today’s appliances. In addition, changes to the certification test 
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method that have the effect of reducing its stringency are inappropriate and undermine the 

integrity of the certification process.

The label “EPA certified” carries great weight with the public and with state and local regulators 

and the fundamental credibility of that label must be rigorously protected by EPA. This means 

that the wood heater NSPS, including the level and form of the standard and underlying test 

methods, should be designed to balance the need for appliances that both perform well in the 

home and produce reproducible results in the laboratory. 

State and local governments have and will invest millions of dollars in communities across the 

nation to replace old dirty wood burning devices with EPA certified stoves. They must be able to 

trust that EPA certification means those devices are the cleanest wood burning devices possible.

WESTAR member states are also very concerned about the prospect of eliminating the 

requirement that a wood heater be tested at a low burn rate (less than one kilogram/hr) since a 

low heat output test is essential to demonstrating the full range of a wood heater device emission 

performance in the real world. 

WESTAR member states are also concerned about the new NSPS being developed for residential 

Outdoor Woodfired Boilers (i.e. Hydronic heaters). We are developing comments to submit to 

EPA in a separate letter.

In conclusion, the recognition that residential wood heating is and will continue to be a major 

source of air pollution requires that EPA establish more stringent wood heater emission limits 

and associated certification test protocols to ensure that we can make progress in cleaning the air.

We look forward to continuing our discussions on revisions to the NSPS. If you have any 

questions about the concerns expressed in this letter, please contact Dan Johnson at 206-254-

9145.

Sincerely, 

David Collier, President

Western States Air Resources Council

cc: Arthur Marin, NESCAUM

Gil Wood, EPA

Greg Green, EPA