N ational Park Service Oral Comments on EPA Proposal for Secondary National Ambient Air Quality Standard for Oxides of Nitrogen and Sulfur August 25, 2011

1) The National Park Service ( NPS ) commend s EPA’s innovative approach to define ecologically

- relevant secondary standard s for oxides of nitrogen and sulfur . The Aquatic

Acidification Index eloquently link s ambient atmospheric concentrations to deposition to ecological impacts. We agree with the Clean Air Science Advisory Committee that t he scientific basis of the Aquatic Acidification Index is sound and well supported.

2) NPS disagrees with EPA ’s decision not to set separate secondary standards for NO

x and

SO

x at this time. We believe that the risks of not acting far outweigh the risk s of proceeding w hile some uncertainties remain

.

3) EPA has clearly demonstrated that the current secondary standards are inadequate to protect sensitive resources. EPA has also clearly demonstrated that resources are being adversely impacted at current leve ls of deposition and that additional reductions in levels of deposition are needed.

4) Our national parks encompass some of the most acid

- sensitive ecosystems in the country

. The Aquatic Acidification Index is appropriate to address impacts for th e se sensit ive ecosystems, such as those in Shenandoah and Great Smoky Mountains National Parks. We encourage EPA to set secondary standards now to protect these sensitive ecosystems.

5) We disagree with EPA’s assertion that uncertainties prevent EPA from understanding the level of protection afforded by a specific level and form of the standard. For example, EPA cites the lack of monitoring data in the western states as an uncertainty, yet EPA has set primary standards for ozone, PM, NO 2 , and SO 2 , despite a lack of monitoring data to adequately describe the spatial variability in the West for these pollutants.

6) EPA cites the need for additional atmospheric and water quality monitoring and proposes a pilot program to address data gaps. Yet EPA has not identified funding for the proposed pilot program

, and it will be 2012 before a plan for such a pilot program is even designed. We strongly encourage EPA t o demonstrate their commitment t o follow through by clearly

identif y i ng the needed f unding for this effort.

7) The pilot program described in the Federal Register focuses on monitoring to improve the

characterization of SO 2 , particle SO 4 , and NO y . NPS agrees with the need to evaluate

methods and would like to participate with EPA in this effort. We encourage EPA to include ecologists in the selection of areas for the pilot program.

8) Funding and program planning are also needed to implement further water quality monitoring to define the sp atial extent of acidified lakes and streams. This has been a need since the original NAPAP assessment was completed in 1990. Without a regulatory requirement, this monitoring has not been a funding priority. Setting separate, deposition

-based secondary st andards now increases the imperative to commit the required funding to better characterize ecosystem sensitivity

.

9) Implementation challenges are real

, but it is not appropriate to delay setting new secondary standards until these challenges are resolved. Because EPA can provide states greater flexibility in attaining the secondary standard, we believe that EPA can set new secondary

standard s concurrent to resolving uncertainties without imposing undue burden to the States and the regulated community. Establishing the secondary standard now will demonstrate EPA’s commitment to protecting ecosystems that are known to be adversely affected by deposition o f NO

x and SO

x and will allow states to begin planning for attainment in the context of other ongoing regulatory efforts.

10) T he one

- hour primary standards for NO 2 and SO 2 are not ecologically relevant to protect sensitive ecosystems. EPA has not provided ev idence that the reductions necessary to

attain the one

- hour standard would provide reduction s in deposition at sensitive receptors. It would be preferable to set deposition

- based standards and refine them as better

information becomes available than to adopt secondary standards that are not relevant for
ecosystems.

11) NPS will be submit ting detailed written comments prior to the close of the public comment period.