4. Regional Administrator Authority The following paragraphs provide background, rationale, and details for the final changes to Regional Administrator’s authority to use their discretion in requiring NO 2 monitors in addition to those required in the minimum monitoring requirements of the two-tier network design. As discussed above in section III.B.2, the proposed rule requi red approximately 167

near-road monitors distributed within CBSAs havi ng populations of 350,000 or more persons. In response to vario us public comments, particularly from states, EPA is changing the population threshold by which one near-road NO 2 monitor is minimally required in a CBSA to 500,000. EPA estimates that this change in the populatio n threshold will result in a reduction in the number of minimally required near-road NO 2 monitors by approximately forty monitors. EPA has also recognized (section II.F.4.d) that ethnic or racial minorities and individuals of low socioeconomic status are at particular risk of NO 2 -related health effects. The Administrator has therefore determined that it is appropriate and necessary to require the Regional Administrators to use their discretion, working in collaboration with states, and site these forty monitors in locations of low income or minority populations . In addition, the Regional Administrators, working with states, may take into account other considerations described below to site

additional monitors. a. Proposed Regional Administrator Authority EPA proposed that Regional Administrators ha ve the authority to require monitoring at their discretion in particular instances. First, EPA proposed that the Regional Administrator will have discretion to require monitoring above the minimum requirements as necessary to address situations where the required near-road monitors do not represent a location or locations where the expected maximum hourly NO 2 concentrations exist in a CBSA. Second, EPA proposed toallow Regional Administrators the discretion to re quire additional near-road monitoring sites to address circumstances where minimum monitoring requirements are not sufficient to meet monitoring objectives, such as a situation where there is a variety of exposure scenarios to NO 2 concentrations in an area because of the variety in the amount or types of fleet mix, congestion patterns, terrain, or geographic areas within a CBSA. And third, EPA proposed that Regional

Administrators shall have the discretion to require additional area-wide NO 2 monitoring sites above the minimum requirements for area-wide mo nitors where the minimum requirements are not sufficient to meet monitoring objectives. have the discretion to require additional area

- wide

NO 2 monitoring sites above the minimum m onitoring requirements where the minimum monitoring requirements f or area

- wide monitors are not sufficient to meet monitoring objectives

. b. Comments EPA received comments from the Center on Race, Poverty and Environment expressing concern that the proposed monitoring provisions fail to consider "disproportionately impacted communities" which include people of color and of lower socioeconomic status that make up the "environmental justice communities. " The commenter argues that this is "a gaping hole" in the proposed monitoring system and disproportionately impacts minority and low income populations in rural communities. In addition, the National Tribal Air Association stated that “Indian tribes and Alaska Natives are highly susceptible to health impacts as a result of NO 2 exposure” and “the prevalence and severity of as thma is higher among certain ethnic or racial groups such as Indian tribes and Alaska Natives,” which is also discussed in section II.B.4 and the ISA (ISA, section 4.4). The proposed rule provided the Regional Admi nistrators with the authority to use their discretion and consider certain factors to require monitors above the minimum number in aCBSA. The proposal described that one example where a Regional Administrator might require

an additional near-road monitor could be where "a particular community or neighborhood is significantly or uniquely affected by road emi ssions." EPA recognizes, as noted in section II.F.4.d, that ethnic or racial minorities and individuals of low socioeconomic status are at particular risk of NO 2 -related health effects, both because of increased exposure and because these groups have a higher prevalence of asthma and higher hospitalization rates for asthma. As noted above, in conjunction with raising the threshold for requiring one near-road NO 2 monitor in a CBSA to those with 500,000 persons or more, EPA is requiring the Regional Administrators , under their discretionary authority, to work with states in devel opment of their monitoring plans to place an additional forty monitors , under their discretionary authority focusing primarily on areas where low income or minority populations (at-risk populations) are located. To address the risks of increased exposure to these at-risk groups , the Administrator has determined that it is appropriate and necessary to ensure that in s iting these additional forty monitors under this provision the Regional Administra tors site them primarily in locations where at-risk populations are exposed to NO 2 concentrations that have the potential to exceed the NAAQS (due to emissions from motor vehicles, point sources, or area sources). As a result of this action, the total number of monitors required through this ru lemaking is not substantially different than the total number of minimally required monitors presented in the proposal , however a subset of the total will target on at-risk popu

. lations.

The EPA also received comments from some state groups (e.g. the New York Department of Environmental Conservation (NYSDEC), New York Department of Transportation (NYSDOT), and the New York City Law Department) and an industry group (the Council of Industrial Boiler Operators) who requested greater clarification on how Regional Formatted: SubscriptAdministrators may use their authority to require additional monitors above the minimum requirements. For example, the Council of Industr ial Boiler Operators stat ed that “this [Regional Administrator authority] unreasonably vests an unbounded amount of discretion in EPA to determine when "minimum monitoring re quirements are not sufficient" and which neighborhoods are "uniquely affected," and impose additional monitoring requirements where all applicable monitoring requirements are already met by the State and local agency.” The Regional Administrator authority to require additional monitoring above the minimum required is not unique to NO 2 . For example, Regional Administrators have or are proposed to have the authority to use their disc retion to require additional Pb monitors (40 CFR Part 58 Appendix D section 4.5), and have the discretion to work with state or locals in designing and/or maintaining an appropriate oz one network, per 40 CFR Part 58 Appendix D section 4.1 EPA believes that while the monitoring network is sufficiently sized and focused, we recognized that a nationally applicable network de sign may not always account for all locations where potentially high concentrations approaching or exceeding the NAAQS may exist in every area of the country . Therefore, EPA believes it is important to have the ability to address issues where gaps may exist in the minimally required monitoring network, which is best accomplished through the Regional Administrator authority to require monitoring above the minimum requirements. One example where the Regional Administrator may exercise their discretion in requiring a monitor might be a location or community impacted by a stationary source where the required

near-road NO 2 monitor site is not the location of maximu m hourly concentration in an area, or in a situation where that same stationary source exists in an area that has no minimum monitoring requirements.. In this example, that un-monitored location could be the location of expectedmaximum concentration in that area. For any given area, there is the possibility that the

maximum NO 2 concentrations could be attributed to impacts from one, or a combination of, multiple sources that could include point, area, and non-road source emissions in addition to onroad mobile source emissions. As a result, the Regional Administrator may choose to require monitoring in such a location. A lternatively, in this same exampl e, if the sources responsible for this situation are producing more widespread impacts on a community or relatively larger area, the Regional Administrator may require an area-wide monitor to assess wider population exposures, or to support other monitor objectives served by area-wide monitors such as photochemical pollutant assessment or pollutant forecasting. Another example where the Regional Administ rator may require additional monitoring could be in situations where a state or local agency is fulfilling its minimum monitoring requirements with an appropriate number of nea r-road monitors, but an additional and somewhat unique location is identified where near-road population exposure exists at concentrations near or above the NAAQS. For this example, the location might be unique due differences in fleet mix, congestion patterns, terrain, or geographic area, relative to any minimall y required monitoring site(s) in that area. We note that such areas might exist in CBSAs with populations less than 500,000 persons, and as a result, the Regional Ad ministrator would be in a position to exercise this discretion for any area of the country where these situations may exist. EPA recognizes that high concentrations of NO 2 that approach or exceed the NAAQS could potentially occur in a variety of scenarios in an area, and we believe that Regional Administrators should have the discretion to require additional monitoring when a location is identified based on the factors discussed in the pa ragraph above. In such situations, state or EPA Regional staff are likely to have identified these locations through data analysis, such as theevaluation of existing ambient data and/or emissions data, or through air quality modeling. Such information may indicate that an area might have ground-level NO 2 concentrations that may approach or exceed the NAAQS, and that there is potential for population exposure to those high

concentrations. The process by which a Regional Administrator would use this authority is part of a collaborative process with state agencies. Typica lly, Regional Administrators work with state and local agencies to design and/or maintain the most appropriate NO 2 network to meet service

the needs for of a given area. For all the situations where a Regional Administrator may require additional monitoring, including the forty 40 additional monitors the R egional Administrators As are required to locate, EPA expects that Regiona l Administrators would work on a case-by-case basis with states in that decision making process. Further, for the forty ad ditional monitors that will primarily on at-risk communities, EPA intends to work with states to develop criteria to aid in the site selection process.

c. Conclusions on Regional Administrator Authority Recognizing that a nationally applicable mo nitoring network design may not always include sites with potentially high concentrations due to case-by-case differences in various locations, and in response to public comments that highlight some of these differences and further consideration of the monitoring network, the Administrator deems it necessary to provide the Regional Administrator the discretion to re quire additional monitoring above the minimum requirements. In response to public comments and furth er consideration of the monitoring network, the Administrator deems it necessary to provide the RAs the discretion to require additional monitoring above the minimum requirements. EPA is requiring that RegionalAdministrators shall use their discretion to work with states to site forty additional NO 2 monitors in locations where low income or minority populations are exposed to NO 2 concentrations that have the potential to appro ach or exceed the NAAQS (e.g., due to emissions from mobile sources, point sources, or area sources). In addition, Regional Administrators shall have the discretion to require monitoring above the minimum requirements as necessary to address situations (1) where the required near-ro ad monitors do not represent a location or locations where the expected maximum hourly NO 2 concentrations exist in an area, or in situations where such a location exists in an area that has no minimum monitoring requirements; (2) where minimum monitoring requirements are no t sufficient to meet monitoring objectives, such as a location that is unique, relative to the minimally required near-road monitors in the area, due to factors that might include fleet mix, congestion patterns, terrain, or geographic location in an area, or in an areas that do not have minimally required near-road monitors where

there are indications that NO 2 concentrations may be approaching or exceeding the NAAQS; and (3) where the minimum monitoring requirements for area-wide monitors are not sufficient to meet monitoring objectives. In these situations where a Regional Administrator may consider the need for additional monitoring, EPA expects that the state and the Regional Administrator w ould ill work together to evaluate quantitative evidence that suggests an area may warrant additional monitoring. EPA also notes that if additional monitoring should be required, as negotiated between the Regional Administrator and the state, the state will modi fy information in its Annual Monitoring Network Plan to include any potential new si tes prior to any approval by the EPA Regional Administrator.