### EPA	Response	to Interagency	Working	Comments	on	Draft	Language	under E.O.	13563	and	12866	Interagency	Review. **EPA Response to 2/26/2014 Comments on U.S. Environm**  **ental Protection Agency Draft Final**  **Rule, “Control of Air Pollution from Motor Vehicles: Tier 3 Motor Vehicle Emission and Fuel Standards,” RIN 2060** 

**- AQ86**  **February 27, 2014** This document refers to the comments received 2/26/2014 on the 2/25/2014 compiled preamble. We accept the edits suggested in comments A1, A2, A5, A7

- 10, and A13

- 16.
**Comment A3: EO12866: Is there a final document that the agency can reference instead**  **of the Second External Review Draft? Suggest not referencing draft documents that are**  **going through review.** EPA Response: We suggest language that would read as follows: Ozone can produce both acute and chronic injury in sensitive species depending on the concentration level and t he duration of the exposure. 1 Inthose sensitive species 2 , effects from repeated exposure to ozone throughout the growing season of the plant tend to accumulate, so that even low concentrations experienced for a longer duration have the potential to create chronic stress on vegetation. 3 Ozone damage to sensitive species includes impaired photosy nthesis and visible injury to leaves. The impairment of photosy nthesis, the process by which the plant makes carbohy drates (its source of energy and food), c an lead to reduced crop yi elds, timber production, and plant productivity and growth. I mpaired photosy nthesis can also lead to a reduction in root growth and carbohy drate storage below ground, resulting in other, more subtle plant and ecosy stems impacts. 4 These latter impacts include increased susceptibility of plants to insect attack, disease, harsh weather, interspecies competition and overall decreased plant vigor. The adverse effects of ozone on areas with sensitive species could potentially lead to species shifts and loss from the affected ecos ys tems, 5 resulting in a loss or reduction in associated ecos ys tem goods and services. Additionally , visible ozone injury to leaves can result in a loss of aesthetic value in areas of special scenic significanc e like national parks and wilderness areas and reduced use of sensitive ornamentals in landscaping. 6

1 73 FR 16486 (March 27, 2008). 2 73 FR 16491 (March 27, 2008). Only a small percentage of all the plant species growing within the U.S. (over 43,000 species have been catalogued in the USDA PLANTS database) have been studied with respect to ozone sensitiv ity

. 3 The concentration at which ozone levels overwhelm a plant’s ability to detoxify or compensate for oxidant exposure varies. Thus, whether a plant is classified as sensitive or tolerant depends in part on the exposure levels being considered. Chapter 9, section 9.3.4 of U.S. EPA, 2013 Integrated Science Assessment for Ozone and Related Photochemical Oxidants. Office of Research and Development/National Center for Environmental Assessment. U.S. Environmental Protection Agency. EPA 600/R

- 10/0 76F. 4 73 FR 16492 (March 27, 2008). 5 73 FR 16493/1649 4 (March 27, 2008) , Per footnote 2 above, ozone impacts could be occurring in areas where plant species sensitive to ozone have not yet been studied or identified. 6 73 FR 16490/ 16497 (March 27, 2008).

### EPA	Response	to Interagency	Working	Comments	on	Draft	Language	under E.O.	13563	and	12866	Interagency	Review. **Comment A4: EO12866: When the agency references air quality, the standard by which air quality improvements is measured is the NAAQS. As the rule is**  **not projected to bring any counties into attainment with the PM NAAQS and only a handful of counties into**  **attainment with the Ozone NAAQS, suggest reverting back to “decreases in air pollution” or using “lead to improvements in air quality.”**  EPA Response : EPA strongl y disagrees with this comment. Air quality is measured by

the concentrations of air pollutants. Any area, whether or not it is attaining a particular NAAQS, can have its air qualit y improved by decreasing ambient concentrations of pollutant s such as ozone, PM, and air toxics. For example, some cities, such as L os Angeles, have had dramatic air quality improvements but are still not attaining. Furthermore, attainment of a NAAQS is not even relevant in reviewing benefits from reductions in n on - NAAQS air pollutants such as air toxics. There are air quality

and health benefits when an area that is exceeding a particular NAAQS comes closer to the NAAQS (even if it doesn’t attain), and there are also health benefits from lowering ozone, PM, and toxics concentrations in areas that are alread y attaining NAAQS levels. Although the NAAQS are set at levels requisite to protect public health, they are not set at levels to eliminate the risk of air pollution. The I ntegrated Science Assessments for PM and Ozone, which were both peer

- reviewed multiple times by EPA’s Clean Air Scientific Advisory Committee, concluded that there does not appear to be a level of exposure to PM2.5 and ozone below which health effects do not occur. Finally , the magnitude of air quality improvement is not measured by the number of counties which move from nonattainment to attainment. I t is also worth noting that Attainment strategies alway s reflect combinations of approaches, and, within that combination, mobile source rules are among the most effective in providing widespread improvement in ambient concentrations. **Comment A6: EO12866: Was this done to make it consistent with the regulatory text?** EPA Response: This edit was made to be consistent with the final report on the sulfur testing. **Comment A11: EO12866: Suggest not making a definitive statement about a future regulatory action by substituting “may” for “will”.**  EPA Response: We have been asked b y the Office of Enforcement and Compliance Assurance and others to have very

strong language on this, and we have already balanced it by

say ing “consider” and “may

be needed.” It is appropriate to say we “will” consider it. **Comment A12: EO12866 suggested: “Consequently, we pledge to work with the refining**  **industry on ways to make information on the sulfur credit market more transparent over the period leading up to 2020, balancing their need for information with the resource**  **constraints of the Agency. In**  **doing so, to protect confidentiality, we will not be able to identify individual company credit balances or deficits, but will provide some aggregated**  **level of information following the agency’s annual compliance determinations that would**

### EPA	Response	to Interagency	Working	Comments	on	Draft	Language	under E.O.	13563	and	12866	Interagency	Review. **help inform the i ndustry of the credit balances for each vintage and deficits carried over**  **from the previous year .”**  EPA Response: **We suggest that it read as follows:** “ Consequently , we pledge to work with the refining industry

on way s to make information on the sulfur cr edit market more transparent over the period leading up to 2020, balancing their need for information with the resource constraints of the Agency

. In doing so, to protect confidentiality , we will not be able to identify individual company

credit balances or deficits, but would intend to provide an aggregated level of information , such as total credit balances for each vintage ye ar
. ” following the agency ’s annual compliance determinations that would help inform the industry of the credit balances for each vintage and deficits carried over from the previous y ear
.