§58.11. Network technical requirements. — Inbound Citations

(b) Any SPM data collected by an air monitoring agency using a Federal reference method (FRM) or Federal equivalent method (FEM) must meet the requirements of §§ 58.11 and 58.12 and appendix A to this part or an approved alternative to appendix A. Compliance with appendix E to this part is optional but encouraged except when the monitoring agency's data objectives are inconsistent with the requirements in appendix E. Data collected at an SPM using a FRM or FEM meeting the requirements of appendix A must be submitted to AQS according to the requirements of § 58.16. Data collected by other SPMs may be submitted. The monitoring agency must also submit to AQS an indication of whether each SPM reporting data to AQS monitor meets the requirements of appendices A and E.

(a) PM 2.5 data. The primary and secondary annual and 24-hour PM 2.5 NAAQS are described in part 50 of this chapter. Monitors that follow the network technical requirements specified in § 58.11 are eligible for comparison to the NAAQS subject to the additional requirements of this section. PM 2.5 measurement data from all eligible monitors are comparable to the 24-hour PM 2.5 NAAQS. PM 2.5 measurement data from all eligible monitors that are representative of area-wide air quality are comparable to the annual PM 2.5 NAAQS. Consistent with appendix D to this part, section 4.7.1, when micro- or middle-scale PM 2.5 monitoring sites collectively identify a larger region of localized high ambient PM 2.5 concentrations, such sites would be considered representative of an area-wide location and, therefore, eligible for comparison to the annual PM 2.5 NAAQS. PM 2.5 measurement data from monitors that are not representative of area-wide air quality but rather of relatively unique micro-scale, or localized hot spot, or unique middle-scale impact sites are not eligible for comparison to the annual PM 2.5 NAAQS. PM 2.5 measurement data from these monitors are eligible for comparison to the 24-hour PM 2.5 NAAQS. For example, if a micro- or middle-scale PM 2.5 monitoring site is adjacent to a unique dominating local PM 2.5 source, then the PM 2.5 measurement data from such a site would only be eligible for comparison to the 24-hour PM 2.5 NAAQS. Approval of sites that are suitable and sites that are not suitable for comparison with the annual PM 2.5 NAAQS is provided for as part of the annual monitoring network plan described in § 58.10.

(a) An SPM is defined as any monitor included in an agency's monitoring network that the agency has designated as a special purpose monitor in its annual monitoring network plan and in AQS, and which the agency does not count when showing compliance with the minimum requirements of this subpart for the number and siting of monitors of various types. Any SPM operated by an air monitoring agency must be included in the periodic assessments and annual monitoring network plan required by § 58.10. The plan shall include a statement of purposes for each SPM monitor and evidence that operation of each monitor meets the requirements of appendix A or an approved alternative as provided by § 58.11(a)(2) where applicable. The monitoring agency may designate a monitor as an SPM after January 1, 2007 only if it is a new monitor, i.e., a SLAMS monitor that is not included in the currently applicable monitoring plan or, for a monitor included in the monitoring plan prior to January 1, 2007, if the Regional Administrator has approved the discontinuation of the monitor as a SLAMS site.

(c) All data from an SPM using an FRM or FEM which has operated for more than 24 months are eligible for comparison to the relevant NAAQS, subject to the conditions of §§ 58.11(e) and 58.30, unless the air monitoring agency demonstrates that the data came from a particular period during which the requirements of appendix A, appendix C, or appendix E to this part were not met, subject to review and EPA Regional Office approval as part of the annual monitoring network plan described in § 58.10.