Information you requested on NO 2: Regional Administrator (RA) Authority on monitoring Lydia Wegman to: hking 12/18/2009 03:04 PM Cc: weinstock.lewis, crabtree.tricia, Watkins.Nealson, j enkins.scott
Heidi, Here is the information you requested on the authority of Regional Administrators to require additional monitors. Please let us know if you have any more questions about this. Lydia ----- Forwarded by Lydia Wegman/RTP/USEPA/US on 12/18/2009 03:01 PM -----

From: Lewis Weinstock/RTP/USEPA/US To: Lydia Wegman/RTP/USEPA/US@EPA Cc: Bridgid Curry/DC/USEPA/US@EPA, Charlotte Bertrand/DC/USEPA/US@EPA, David Orlin/DC/USEPA/US@EPA, John Hannon/DC/USEPA/US@EPA, Karen Martin/RTP/USEPA/US@EPA, Nealson Watkins/RTP/USEPA/US@EPA, Richard Wayland/RTP/USEPA/US@EPA, Scott Jenkins/RTP/USEPA/US@EPA, Wayland.Richard@epamail.epa.gov, Padmini Singh/DC/USEPA/US@EPA Date: 12/18/2009 01:12 PM Subject: OMB requested information of NO2: Regional Administrator (RA) Authority on monitoring
Lydia: Please forward to Heidi, as was requested during the morning call.

--------------------------------------------------------------------------------- The relevant language from the monitoring section (III) of the preamble is included in the attachment. This authority would be "bounded" by the need for state and/or regional office data analyses such as the evaluation of existing ambient data and/or emissions data, or through quantitative measures such air quality modeling, that indicate that an area might have ground-level NO2 concentrations that may exceed the NAAQS (in locations not already covered by minimum monitoring requirements). Quantitative information would form the basis of the RA decision. Several examples of why this type of RA authority might be employed are included in the preamble. We note factors that might be considered by the RA in the evaluation of additional monitoring requirements including: (1) the variety in the amount or types of fleet mix in an area, (2) congestion patterns, (3) terrain, or (4) geographic areas within a CBSA. We also note that the decision would be documented in annual monitoring network plans that are updated annually by states and posted for the public. Where else in current monitoring regulations can this type of authority be found? Several examples are documented in this message. Key passages are highlighted in yellow (hope it shows in your email system) 40 CFR Part 58, Appendix D - Network Design Criteria for Ambient Air Quality Monitoring http://ecfr.gpoaccess.gov/cgi/t/text/text-idx?c=ecfr& sid=16139e5d8e6819a456d374 e25024f390&rgn=div9 &view=text&node=40:5.0.1.1.6.7.1.3.32&idno=40 4.1 Ozone (O 3 ) Design Criteria. (a) State, and where appropriate, local agencies must operate O 3 sites for various locations depending upon area size (in terms of population and geographiccharacteristics) and typical peak concentrations (expressed in percentages below, or near the O 3 N AAQS). Specific SLAMS O 3 site minimum requirements are included in Table D–2 of this appendix. The NCore sites are expected to complement the O 3 data collection that takes place at single- p ollutant SLAMS sites, and both types of sites can be used to meet the network minimum requirements. The total number of O 3 sites needed to support the basic monitoring objectives of p ublic data reporting , air quality mapping , compliance , and understanding O 3 - related atmospheric processes will include more sites than these minimum numbers required in Table D– 2 of this appendix

. The EPA Regional Administrator and the responsible State or local air monitoring agency must work together to design and / or maintain the most appropriate O 3 network to service the variety of data needs in an area

. (b) Within an O 3 network, at least one O 3 site for each MSA, or CSA if multiple MSAs are involved, must be designed to record the maximum concentration for that particular metropolitan area. More than one maximum concentration site may be necessary in some areas. Table D– 2 of this appendix does not account for the full breadth of additional factors that would be considered in designing a complete O 3 monitoring program for an area . Some of these additional factors include geographic size, p opulation density, complexity of terrain and meteorology, adjacent O 3 monitoring programs, air pollution transport from neighboring areas, and measured air quality in comparison to all forms of the O 3 N AAQS (i.e., 8-hour and 1-hour forms). N etworks must be designed to account for all of these area characteristics. N etwork designs must be re-examined in p eriodic network assessments. Deviations from the above O 3 requirements are allowed if approved by the EPA Regional Administrator

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--------------------------------------------------------------------------------------------------------- 4.5 L ead ( P b ) D esign Criteria. (a) State and, where appropriate, local agencies are required to conduct ambient air Pb monitoring taking into account Pb sources which are expected to or have been shown to contribute to a maximum Pb concentration in ambient air in excess of the N AAQS, the potential for population exposure, and logistics. At a minimum, there must be one source-oriented SLAMS site located to measure the maximum Pb concentration in ambient air resulting from each Pb source which emits 1.0 or more tons per year based on either the most recent National Emission Inventory ( http://www.epa. g ov /

ttn /

chief /

eiinformation.html ) or other scientifically justifiable methods and data (such as improved emissions factors or site-specific data) taking into account logistics and the potential for population exposure.
(i) One monitor may be used to meet the requirement in paragraph 4.5(a) for all sources involved when the location of the maximum Pb concentration due to one Pb source is expected to also be impacted by Pb emissions from a nearby source (or multiple sources). This monitor must be sited, taking into account logistics and the potential for population exposure, where the Pb concentration from all sources combined is expected to be at its maximum.
( ii ) The Regional Administrator may waive the requirement in paragraph 4

. 5 ( a ) for monitoring near Pb sources if the State or , where appropriate , local agency can demonstrate the Pb source will not contribute to a maximum Pb concentration in ambient air in excess of 50 % of theN AAQS ( based on historical monitoring data , modeling , or other means ). The waiver must be renewed once every 5 years as part of the network assessment required under 58

. 10 ( d ).
(b) State and, where appropriate, local agencies are required to conduct Pb monitoring in each CBSA with a population equal to or greater than 500,000 p eople as determined by the latest available census figures. At a minimum, there must be one non-source-oriented SLAMS site located to measure neighborhood scale Pb concentrations in urban areas impacted by re-entrained dust from roadways, closed industrial sources which previously were significant sources of Pb, hazardous waste sites, construction and demolition projects, or other fugitive dust sources of Pb.
( c ) The EPA Regional Administrator may require additional monitoring beyond the minimum monitoring requirements contained in 4

. 5 ( a ) and 4

. 5 ( b ) where the likelihood of Pb air quality violations is significant or where the emissions density , topography , or population locations are complex and varied

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Lewis Weinstock Group Leader, Ambient Air Monitoring Group U.S. EPA Office of Air Quality Planning and Standards MD C304-06 Research Triangle Park, NC 27711 919-541-3661 919-541-1903 (Fax)