UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION 10

Ms. BarbaraTrost Air and Water Quality Division 1200 Sixth Avenue, Suite 900 Seattle, WA 98101-3140



## OCT 25

## 2012

Alaska Department ofEnvironmental Conservation 555 Cordova Street Anchorage, Alaska 99501-2617

Dear Ms. Trost: OFFICE OF AIR, WASTE AND TOXICS

We have evaluated the 2012 Alaska Ambient Air Monitoring Network Plan, which describes the Alaska monitoring network for 20I2-I3. EPA has the following comments on the proposed changes in the network plan:

I. Discontinued operation ofthe FRM PMI0 monitor at the Parkgate site (02-020-1004) in Eagle River. MOA continues to operate a FEM PMI0 monitor at this site. EPA approves this change. 2. The particulate monitoring system at the Butte site in the Mat-Su Valley was modified in late 201 I by installing a new Coarse-BAM pairofMetOne BAM I020X monitors to measure PMI0 and PM2.5. As ofJanuary I, 20I2, the new BAM PM2.5 monitornow serves as the primary monitors for EPA's Air Quality System (AQS) database for this SLAMS site. EPA approves this change. 3. The Fairbanks North Star Borough will discontinue PM2.5 monitoring activities at the TAC (Peger Road) site for the winter of20I2-20I3. Moving the monitoring equipment to another location is under consideration. This is not a required monitoring site. EPA approves this change. 4. The city ofSeward conducted PMJ0 monitoring at three sites to determine the PMI0 concentrationsbeing emitted from the Seward Coal Loading facility. None ofthe sites in this study showed PMJ0 concentrations close to the NAAQS. The city ofSeward terminated this monitoring program in May 20I2. EPA approves the termination ofthis monitoring program. 5. The Municipality ofAnchorage anticipates concluding the year ofmonitoring for TSP-Lead at the Merrill Field Airport in October20I2. The data will be finalized and a report issued by April 2013. EPA funded this project for one year ofoperation. Depending on the Pb concentrations found at this site, it will be either shut down, orcontinue operation ifPb levels are> 50% ofthe Ph NAAQS. EPA concurs with this process. 6. MOA is considering discontinuing ozone monitoring at the Garden Site after the 2012 ozone sampling season and will prepare a waiver request document in cooperation with the DEC. The 20I0-20II 4 1h highest average for this site is 0.045 ppm, which is substantiallybelow the ozone standard of0.075 ppm. EPA will take action on the waiver request after we receive it.

()PrintedonRecycledPaperThe following monitors arc designated "core" monitors because they arc either: (I) required hy 40 CFR Part 58, Appendix D, (2) have a design value ncar or above the new PM2.5 24-hour standard of 35ug/m3, 

### or (3) they arc essential monitoring parameters at NCorc sites:
I. PM2.5 FRMs (or Approved Regional Method): a) Fairbanks (primary and secondary) b) Juneau c) Butte

2. PM2.5 speciation and precursor gas monitoring at the Fairbanks NCorc site.

Core" monitors arc those monitors in the network that must be operated with available PM2.5 monitoring funds. The "nun-core'' PM2.5 monitors in the State's network can he operated at ADEC's discretion with any remaining federal funds or State funds.

On September 13, 2012, ADEC submitted a request for waiver ofthe lead SLAMS air monitoring requirement for the Red Dog Mine. In an email response sent from EPA to ADEC on September 20, 2012, we identified several outstanding technical issues related to the lead emission factors from the Red Dog Mine that need to be resolved before we can evaluate the modeling results that support your request for a waiver. As soon we receive the additional information requested in this response, we will proceed with our review ofyour waiver request.

Ifyou have any questions about our approval ofthe Alaska monitoring network, please contact Keith Rose at (206) 553-1949.

cc: Chris Hall, OEA Keith Rose, OAWT Claudia Vaupel, OAWT Sincerely,

# ~b{Jc**ill~k;** Debra M. Suzuki, Manager 

# J
State and Tribal Program Unit



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