Response to OMB

– CO NFR

Issue #1

– Population threshold by which CO monitors are to be required The EPA proposed the population threshold by which CO monitors would be required (collocated with near - road NO 2 monitors) to be CBSAs with populations of 1 million or more persons . The Agency

received public comment from public health and environmental groups to lower the threshold to 500,000 (matching NO 2 requirements), effectivel y adding to the total number of required monitors, while a number of states su ggest ed the threshold be raised to a threshold of 2.5 million, effectivel y reducing the total number of required monitors. The Agency also received comment from one industry commenter (API) who stated that the 1 million threshold “...appears appropriate, but EPA should not require that both [near - road NO 2 ] sites in the largest CBSAs host CO monitors.” As noted in the preamble text, the EPA believes that the population threshold of 1 million is an appropriate threshold by which to require CO monitors, as it w ill re sult in a sufficientl y sized national network to meet monitoring objectives. In their public comment s, ALA, ATS, an d EDF described the proposed threshold to be more akin to a ‘pilot project’ due to its lack of size. While EPA does not believe the network needs to be so large to include CBSAs with 500,000 people or more, the Agency does view a network required onl y in C BSAs of 2.5 million or more persons to provide an insufficient level of geographic coverage to be considered a national network , as it would only cover 21 urban areas (based on recently released 2010 Census Bureau data) . The use of the 1 million populati on threshold is an efficient design requiring what the Agency believes is a sufficient number of monitor s over a broad geographic area , representing approximately

52 different urban areas which contain approximately 55% of the total US population (based on recently published 2010 Census Bureau data). Additionally , this threshold provides for monitoring of a wide range of diverse situations with regard to traffic volume, traffic patterns, roadway

designs, terrain/topography , meteorology , climate, as well as surrounding land use and population characteristics. This more robust network will better support the evaluation of compliance with the NAAQS and support future NAAQS reviews. Additionally , the EPA notes that state and local air agencies will be in a po sition to move existing monitors or pull anal yz ers out of storage for insertion in the near - road NO 2 monitoring infrastructure to satisfy

the near - road CO monitoring requirements. Accordingl y, the Agency believes that the costs and burden associated with the implementation of the 1 million person threshold are minimal, only $815 per required monitor , based on ICR calculations (~$0.06 million, network wide, for the relocation of approximately 77 CO monitors) . Further, the EPA believes that state and local air agencies will likely be able to shut - down some existing single pollutant CO monitoring sites as they relocate their monitors. The se shut - down s of single pollutant sites will reduce overall resource burden to any air agency b y reducing the total number of monitoring sites they

operate (across all NAAQS pollutants). Inthe final rule EPA has postponed the deadline for installation of CO monitors from the proposed deadline of January 1,2013 to January 1, 2015 in order to provide time for states to prepare the near road infrastructure for NO 2 monitors and to allow time for EPA to approve the shutdown and transfer of monitors, as appropriate. In summary , the EPA believes that the 1 million person threshold support s the establishment of a m inimally sufficient national CO network near roads , as part of a mul ti pollutant monitoring paradigm, at a near negligible cost.

Issue #2

– Safety in the near - road environment The EPA recognizes safety as a top priority

in the implementation of any near - road monitoring requirements. This is evident in the preamble to the final rule promulgating the requirements for near - road NO 2 monitors. By requiring CO monitors to be collocated with near road NO 2 monitors, network implementation issues such as sa fety will effectively

be handled as the near - road NO 2 network is installed. In an effort to support state and local air agencies in the implementation of near - road NO 2 sites, the EPA is collaborating with US DOT

– Federal Highway s, several state DOTs (Flo rida & Texas), along with partner state and local air agencies, to provide technical assistance on near- road site implementation to the air monitoring community . Safety is a key subject in that assistance, with topics covering issues of right - of - way acces s, the use of safety features such as guardrails or recognition of ‘clear zones’, and how to engage DOTs to ensure safety of the travelling public, air monitoring staff, and air monitoring infrastructure at near - road monitoring sites. Further, monitoring by roads for CO is not a new concept to states and local air agencies. They have been monitoring near roads, mainly in downtown areas and in urban street canyons, since the late 1970s. The EPA believes that state and local air agencies are very aware of safety

issues, in part based on existing experience, and the Agency

is confident that they

will be able to successfull y implement near - road monitoring sites safel y through the use of the technical assistance to be provided and by working with their respect ive DOTs as necessary .