UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

REGION 10 

Mr. Anthony Barnack 

Air Monitoring Program 

1200 Sixth Avenue, Suite 900 

Seattle, WA 98101-3140 

OCT 2 6 2012 

Oregon Depmtment of Environmental Quality 

811 SW Sixth A venue 

Portland, OR 97204-1390 

Dear Mr. 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 of a 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 roadway plan, <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 collocated N02 as a substitute for the NOy data. If ODEQ 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 number of 

monitoring objectives, available commercial instruments may indicate little 

difference in their measurement ofNOy compared to the conventional 

measurement ofNOx, particularly in areas with relatively fresh sources of 

nitrogen emissions. Therefore, in areas vvith negligible expected d~flerence 

between NO.v and NOx measured concentrations, the Administrator ma.v allowfor 

waivers that permit NOx monitoring to be sithstitutedfor the required NO_v 

monitoring at applicable NCore sites. 

3. ODEQ intends to discontinue the Pb TSP monitoring at the fence line of Cascade 

Rolling Mills in McMinnville, Oregon in 2013. Funding saved by this discontinuation 

will be transferred to support the operation of a CO monitor at the N02 roadway site. To 

date, the results of the McMinnville Pb monitor are below 1

4 of the NAAQS. Shut down 

of the Pb monitor is allowed under CFR Pt 58, App D, sec 4.5(a)(ii), with the condition 

that the state demonstrates that the design value is less than 50% of the NAAQS. ODEQ 

will have to submit the data, and calculation of the design value, to EPA for review 

before we can approve shutting down this site. 
4. ODEQ proposes discontinuing the P01tland Transcon PM10 FRM (41-051-0009) in NW 

Portland because it is no longer a maximum concentration site (its original purpose). 

P01tland is required to have two monitors based on population. It cmTently has three PM 10 

monitoring sites (Transcon'in NW Portland, SE Lafeyette in SE Portland, and N. Roselawn 

inN P01tland). All current have design values less than 113 of the 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 PM10 monitor to operate a 

PM25 monitor at the N02 near roadway site in 2013. EPA approves this change. 

5. LRAPA proposes moving the PM10 and PM2.5 monitors at the Eugene Key Bank site 

( 41-039-0058) 170 meters to the northwest to a new site called the H wy 99 site (41-

039-0059) because the owners of the 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 PM10 samplers at both sites for comparison and found no significant difference 

between them. The linear regressions R2 

was 0.974 and the t-test had a P =0.82. EPA 

approves the relocation of the PM 10 and PM2.5 monitors to the new site. 

6. The one remaining state-funded air toxics site is CUITently operating in Medfo~d. If its 

funding continues, the site will finish a year of monitoring in December, 2012. After 

this, it will be relocated to the Portland Metro area in support of the Portland Air Toxics 

Solutions program. EPA approves this change. 

7. LRAP A also proposes moving the PM2.

5 speciation sampler from Oakridge (41-039-2013) 

to Eugene Hwy 99 site (41-039-0059) f01· two reasons: 1) LRAPA has several years of data 

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 ODEQ would like to compare visibility in that 

urban area to the secondmy PM2.5 standard. EPA approves the relocation of this speciation 

monitor to Eugene. 

The following monitors are designated "core'' monitors because they are either: 1) required 

by 40 CFR Part 58, Appendix D, 2) have a design value near or above the new PM2.5 24-

hour standard of 35ug/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 N A TTS 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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c) 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. If you have any questions about our approval of the Oregon monitoring network, 

please contact Keith Rose at (206) 553-1949. 

cc: Paul Kaprowski, 000 

Keith Rose, OA WT 

Chris Hall, OEA 

Jeff Smith, ODEQ 

Claudia Vaupel, OA WT 

Sincerely, 

~~··/() 

Debra M. Suzuki, Manager~ State and Tribal Program Unit 

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