DRAFT

Near-road Guidance Document – Outline

1. Introduction – This includes objectives of docum ent, summary of content, and references the preamble/rulemaking. As part of the objectives, we will include language on the interest in balancing required monitoring with multi-pollutant monitoring objectives. We will also note: 1) CASAC AAMM feedb ack and, 2) information on and from nearroad pilot efforts.

2. Background – This includes some literature revi ew and specifies what is required in the regulation text to site nea r-road stations. Given the abundance of literature on this subject, the literature revi ew should focus on identifying the locations and parameters

associated with where the maximum con centration occurs (from a multi-pollutant perspective – i.e., for NOx, CO, PM, etc – how they’re the same or different).

3. Identifying Candidate Near-road Site Areas

a. Information Collection – Identifying what resources are needed, where they can be found, and what those data can be used for.

b. Ranking Roads by AADT – Using AADT to focus the site selection process

c. Other Candidate Near-road Site Considerations

1. Fleet Mix (notably numbers of heavy-duty trucks/buses)

2. Roadway Design

3. Congestion Patterns/Level of Service (LOS)

4. Terrain

5. Meteorology

6. Population Density/Characteristics (e.g. SES)

4. Modeling – How modeling can be used to supplement the near-road siting process

5. Monitoring - How saturation and/or mobile monitoring can be used to supplement the near-road siting process

6. Near-road Site Selection

a. Safety

b. Logistical Considerations

c. Collaborating with othe r government agencies

d. Physical Site Characteristics (e.g. dist ance, terrain, roadway configuration)

7. Recommended Near-road Site Documentation – This includes recommendations on what to include in annual monitoring network plans and the creation of an “NCore-type” site characterization document for each permanent near-road monitoring station.DRAFT – 8/24/10 Near-road Monitoring Pilot Study Objectives & Approach

In January of 2010, the EPA promulgated mon itoring requirements (s ee attached pdf of the Federal Register for the Primary Nationa l Ambient Air Quality Standards for Nitrogen Dioxide; Final Rule, with revised monitoring la nguage beginning on page 6435 of the notice) in support of the revision to the primary NO X National Ambient Air Qual ity Standards (NAAQS). As part of the rulemaking, certain state and local air agencies are require d to operate near-road

NO 2 monitors, which are defined in 40 CFR Part 58, Appendices D and E. As part of this rulemaking, in response to public comment, EP A committed to creating near-road monitoring guidance materials which would be supplemented by a near-road monitoring p ilot study to assist state and local air monitoring agencies in the implementation of required near-road monitoring stations. This document is intended to presen t and elaborate upon the pr imary objectives for the near-road monitoring pilot study. EPA intends for this pilot study to provide real-world experience in near-road monitoring implementati on and also inform the forthcoming near-road monitoring guidance documentation.

Pilot Objectives The primary objective of the near-road monitoring pilot is to allow EPA, state, and local air monitoring stakeholders to evaluate, improve , and document the near-road monitor siting

process . This objective encompasses the main process that state and local air agencies will have to execute when selecting and installing every re quired near-road monitor. As a result, pilot participants are gathering experi ence that can then be translated and communicated to all state and locals who will be going through this process in the near future. The pilot study process may provide clarity or answer the following:

1. State and local agencies must consider fleet mix, roadway design, congestion patterns, terrain, and meteorology in the s ite selection process. Is th ere a relative priority amongst these factors? Should (could) the near-road monitoring pilot inform whether there are mechanisms by which to prioritize or ‘weight’ th ese factors in the site selection process?

a. For example, how may a state or local agen cy utilize fleet mix information (which quantifies passenger car and heavy-dut y truck volumes on individual road segments that will likely affect pollutant emissions differently) in their site selection process?

b. What other different types of data mi ght be available to states (e.g., Annual Average Weekday Traffic, Level of Service, etc.), how current is such data, and what do they mean, or, how are they useful?

2. What approach should be used to bala nce between strictly satisfying minimum monitoring requirements (such as those for near-road NO 2 monitors) and serving multipollutant monitoring objectives? A prime example includes evaluating how near-road monitors might be sited in a way to acco mmodate monitoring in a location of greatest

interest/need for NO 2 , CO, and PM2.5.3. Can the pilot be supportive or informative to modeling need s, and/or can the pilot be supplemented by existing modeling capabilities?

4. How effectively do the factors and ava ilable data described above support the

identification of the maximum concentrati on location(s) available within a CBSA?

a. What is the likely variation between ma ximum concentrations expected at the candidate locations identified using the a bove factors? How ca n a state or local agency utilize modeling and/or saturation monitoring techniques to further

characterize candidate near-road locations?

5. How will states mitigate issues on worker/tra ffic safety in near-road site selection, installation, and on-going operations?

a. E.g., will air agencies need to ensure th at monitoring stations are placed behind guardrails, or that they will need to work to have guardrails installed as appropriate near their near-road monitoring stations?

b. E.g., what are any given state’s existing se t-back rules? Are there issues with driver sight lines because of a monitoring station?

6. What other government agencies will state a nd local air agencies n eed to communicate or

collaborate with to achieve success in th e selection and installation of near-road monitoring stations?

7. Can the pilot suggest an approach by which st ate and local agencies, and EPA, can verify that the most logical and appropriate sites ar e being selected for the permanent near-road monitoring stations where AADT, fleet mix, ro adway design, congestion patterns, terrain, and meteorology have been considered?

Pilot Study Approach The pilot study objectives can likely be met with a two-pronged approach. The first prong could be considered as a quasi-saturation monito r based evaluation, specifically to look at how a city could evaluate the effects of fleet mix, roadway design, congestion patterns, terrain, and meteorology on pollutant concentrations within their particular CBSA. The second prong could focus on the selection and installation of permanent near-road monitoring stations in at least two urban areas, using information gained as part of the first prong. Betw een these two prongs, EPA believes that all of the questions above, as part of the pilot obj ectives, and questions relating to guidance document preparation will be addressed to some degree. The data collected in the permanent pilot sites and the satu ration monitoring studies should be analyzed to meet the pilot study objectives.

The first prong, which may inform the second prong, could focus on deploying 4 or more saturation type monitoring “packages” (where a “package” would be mountable, mobile, or otherwise easy to deploy multi-pollutant measur ement devices) along different road segments in an area to more directly ascer tain how one or more of fleet mix, roadway design, congestion patterns, terrain, and meteorology may affect pol lutant concentrations . Subsequently, theinformation extracted from this pilot may have more useful information 1) where permanent stations part of the prong 2 of the pilot study may be placed, and 2) to provide more information to states on exactly how they can account for all of the above mentioned c onsiderations in their site selection process. This prong of th e pilot may be accomplished with non-FRM/FEM methods that are pole-mountable or allow for m obile monitoring. There are passive devices and semi-continuous analyzers available that may be a ppropriate to use in this prong of the pilot.

The near continuous methods would be most desirable since the revised NAAQS is a 1-hour standard and intended to protec t against 1-hour peak exposures. However, on a cost basis, passive methods could allow for the number of se gments that could be evaluated at one time to be significantly increased. Unde r the guise of using four or more near continuous monitoring method packages, one specific way to place the i ndividual monitoring pack ages to address pilot objectives could be to purposefully place monitor packages at roads with specific characteristics including:

 At the highest AADT segment in an area.

 At the road segment with the highest nu mber of heavy-duty truck/bus counts.

 At a road segment with more unique road way design, congestion pattern, or terrain.

 If feasible, at a lower AADT segment with a similar fleet mix, roadway design, congestion, terrain, and meteorology as the top AADT road segment. This package, compared to the first road segment, coul d potentially isolate the impact of AADT on concentrations between two road segments.

The second prong of the pilot would focus on establishing long-term near-road monitoring stations that satisfy minimum monitoring requirements resulting from the recent NO X NAAQS revision. This would include the overall proce ss of identifying a pool of candidate near-road sites and subsequently selecting a site and installing the monitori ng station. There are options on

what the selection criteria s hould be for the cities installing a permanent near-road monitoring station. Therefore, this prong may want to tr y to use information gained from prong 1 of the pilot study, or, if possible, focus on urban ar eas that have no road s with outstanding heterogeneity with respect to fleet mix, ro adway design, congestion patterns, terrain, and meteorology in selecting where permanent type site s may go. Of such urban areas, other metrics

for consideration include:

 Large versus small urban areas – Smaller urban areas (< 2.5 million) are only required to have one near-road site. Do they have tougher decisions to make than a larger urban area with regard to how to treat variances in fleet mix or any of the other ‘considerations’ that must be made? Should the pilot include a city that is relatively small, but represents the only urban area in a state that will have a n ear-road monitor? Should this proposed first prong include one large and one smaller urban area?

 Terrain and meteorology – Urban areas with more varied and complex terrain or meteorology may provide an informative experi ence to share with other states versus

urban areas with rather flat or unremarkable terrain or meteorology.

 Urban areas where the state or local air agency may or may not have local/state support, such as a DOT amenable to coopera te in aiding site installations.

 An urban area with an operational NO X analyzer that is considered representative of the broader urban background. This would provi de information on how much higher nearroad concentrations are when compared to re lative background concentrations in order to identify the road’s contribution. An urban area with a DOT or Metropolitan Planning Organization (MPO) with detailed traffic information and pr oject modeling results.

Near-Road Site Implementation and Documentation The pilot study will also provide information a nd documentation that will assist states in the implementation of their near-road monitoring sites. These include:

 Data Collection – Where can traffic and other pertinent data be f ound, which data sources were and were not useful, and wh at obstacles were encountered?

 Candidate Site Selection and Data Analysis – How was the data evaluated and interpreted in order to select the candidate sites, and how could this process be refined and improved?

 Near-Road Site(s) Selection – When evaluating candidate sites, what unforeseen obstacles were encountered, how accurate were the data collected, and what difficulties were encountered in establishing the site?

 Approvals and Installation – Af ter selecting the site location(s), what approvals were needed and how cooperative were state and lo cal agencies and organizations? Were any obstacles encountered when installing the si te, such as safety or electricity access?

 Operation and Maintenance – During the time of operation, were any is sues or difficulties encountered such as safety, inconsis tent operation, access limitations, etc.?