UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION 10

Mr. Anthony Barnack Air Monitoring Program 1200 Sixth Avenue, Suite 900 Seattle, WA 98101-3140



## OCT 

## 262012

Oregon Depmtment ofEnvironmental Quality 811 SW Sixth Avenue Portland, OR 97204-1390

DearMr. Barnack:

We have evaluated the 2012 Oregon Ambient Air Monitoring Network Plan, which describes changes to the OR monitoring network for 2012-13. The proposed changes, and EPA's responses, are listed below:

1. ODEQ submitted an N02 Roadway monitoring site plan which proposed an N02

near roadway site in Portland, to be installed and operated in 2013, pending identification ofa specific monitoring location and funding to operate this site. EPA cannot approve the monitoring site until a specific location has been selected and ODEQ commits to operating it. When these conditions have been met, ODEQ should modify its N02 near roadwayplan, <md resubmit the plan to EPA for review and approval. 2. ODEQ desires to discontinue the NOy monitor at the Portland NCore site, and use data from the collocatedN02 as a substitute for the NOy data. IfODEQ can demonstrate that NOy and NOx concentrations are nearly identical at this site, then EPA can approve discontinuing the NOy monitor as long as the N02 monitoring continues operation. EPA can approve this request upon the demonstration by ODEQ that there is a negligible difference between the NOy and NOx levels at this site, as explained in Part 58, Appendix D, section 3(b)( 1): 

### 'Although the measurement ofNOy is required in support of a numberof monitoring objectives, available commercial instruments may indicate little difference in theirmeasurementofNOycompared to the conventional
measurement ofNOx,particularly in areas with relativelyfresh sources of nitrogen emissions. Therefore, in areas vvith negligible expected**d~flerence** 

### between NO.v andNOx measuredconcentrations, theAdministratorma.v allowfor waivers thatpermitNOx monitoring to be sithstitutedforthe requiredNO_v monitoring atapplicableNCore sites. 3. ODEQ intends to discontinue the PbTSP monitoring at the fence line ofCascade Rolling Mills in McMinnville, Oregon in 2013. Funding savedby this discontinuation will be transferred to support the operation ofa CO monitor at the N02 roadway site. To date, the results ofthe McMinnville Pb monitor are below 1 4 ofthe NAAQS. Shut down ofthe Pb monitor is allowed underCFR Pt 58, App D, sec 4.5(a)(ii), with the condition that the state demonstrates that the design value is less than 50% ofthe NAAQS. ODEQ will have to submit the data, and calculation ofthe design value, to EPA for review before we can approve shutting down this site.4. ODEQ proposes discontinuing the P01tland Transcon PM 10 FRM (41-051-0009) in NW Portland because it is no longer a maximumconcentration site (its original purpose). P01tland is required to have twomonitors based on population. It cmTently has three PM10 monitoring sites (Transcon'in 

### NW Portland, SE Lafeyette in SE Portland, and N. Roselawn inN P01tland). All current have design values less than 113 ofthe NAAQS. The duplicate monitor will move from Transcon to the Portland, SE Lafayette site. ODEQ proposes using the operating funds saved by shutting down the Transcon PM 10 monitor to operate a PM25 monitor at the N02 near roadway site in 2013. EPA approves this change. 5. LRAPA proposes moving the PM 10 and PM2

.5monitors at the Eugene Key Bank site (41-039-0058) 170 meters to the northwest to a new site called the Hwy 99 site (41- 039-0059) because the owners ofthe Key Bank site asked LRAPA to vacate. Hwy 99 is the nearest acceptable location and it is at ground level in the breathing zone. It is also safer and more convenient then the old Key Bank site. LRAPA simultaneously

ran PM 10 samplers at both sites for comparison and found no significant difference between them. The linearregressions

### R2was 0.974 and the t-test had a P =0.82. EPA approves the relocation ofthe PM10 and PM2

.5 monitors to the new site. 6. The one remaining state-funded airtoxics site is CUITently operating in**Medfo~d.** Ifits funding continues, the site will finish a year ofmonitoring in December, 2012. After this, it will be relocated to the Portland Metro area in support ofthe Portland AirToxics Solutionsprogram. EPA approves this change. 7. LRAPA also proposes moving the PM2

.5 speciation samplerfrom Oakridge (41-039-2013) to Eugene Hwy 99 site (41-039-0059) f01· two reasons: 1) LRAPAhas several years ofdata at Oakridge, which is dominated by wood burning impacts. More data from this site would not add any value, and 2) EPA is proposing a PM2

.5 secondary standard which uses speciation data to dete1mine visibility in urban areas. Eugene/Springfield is the second largest metropolitan area in Oregon, and ODEQwould like to compare visibility in that urban area to the secondmy PM2.5 standard. EPA approves the relocation ofthis speciation monitorto Eugene.

The following monitors are designated "core'' monitors because they are either: 1) required by40 CFR Part 58, Appendix D, 2) have a design value near or above the new PM2.5 24- hour standard of35ug/m3, or 3) they are essential monitoring parameters at NCore sites:

1. PM2.5 FRMs (or Approved Regional Method): a) P01tland/SE Lafayette b) Portland/N Roselawn c) Medford (primary and co-located) d) Eugene (primary and co-located) e) La Grande NATTS site f) Klamath Falls g) Oakridge h) Lakeview i) Pendleton 2. PM2.5 speciation monitors: a) P01tland/SE Lafayette b) Eugene/Amazon Park

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()PrintedonRecycledPaperc) Medford/Grant & Belmont d) Klamath Fall 3. Pre-cursor gas monitors at the Portland/SE Lafayette NCore site

With this letter, EPA is approving the Oregon Annual Monitoring Network Plan, including the area-wide N02 monitor at the Portland NCore site, but is not approving the plan for N02

near roadway monitoring. As explained above, ODEQ should modify its N02 near roadway monitoring plan to identify a specific monitoring location and resubmit the plan to EPA for approval. Ifyou have any questions about our approval ofthe Oregon monitoring network, please contact Keith Rose at (206) 553-1949.

cc: Paul Kaprowski, 000 Keith Rose, OAWT Chris Hall, OEA JeffSmith, ODEQ ClaudiaVaupel, OA WT Sincerely,

# ~~··/() Debra M. Suzuki,

# Manager~ State and Tribal Program Unit

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