1. Passive Ammonia Monitoring in the Four Corners Presented at WESTAR Technical Conference on Oil and Gas Development, Pinedale, Wyoming, September 12- 13, 2007

2. Ammonia Baseline Monitoring in Four Corners Area In September, 2005, the Interim Emissions Workgroup of the Four Corners Air Quality Task Force recommended that an ambient monitoring program for gaseous ammonia be initiated in the Four Corners area. Purpose: To set a current baseline of ambient gaseous ammonia concentrations in the Four Corners area that can be compared to future monitored values in approximately 3-5 years after the implementation of NO x controls (e.g. NSCR) on oil and gas equipment. The use of NSCR may increase ammonia emissions in the area, but these emissions have not been quantified and may or may not significantly increase, or significantly affect visibility. 5 sites in Four Corners area plus one rural reference site in Oklahoma (the Cherokee Nation’s Stilwell site) are sampling for ambient ammonia throughout the calendar year 2007; An additional source reference site in NE OK added in July, 2007.

3. Site Locations Many thanks To NMED, Southern Ute Tribe, NPS, Cherokee Nation, and Quapaw Tribe for site operations and sample change-outs.

4. Oklahoma Site Locations

5. Ammonia Baseline Monitoring using Passive Samplers To keep costs low for this initial screening study of ambient gaseous ammonia in the Four Corners area, Ogawa passive sampling devices (PSDs) are being used. NMED purchasing filters. EPA Region 6 Houston Lab is in charge of preparing Ogawa PSDs for ammonia sampling, shipping PSDs to sites via Fed-Ex or UPS, and conducting IC analyses of filters. 3-week integrated sampling at all sites. EPA Region 6 Dallas is conducting initial analysis and interpretation of the draft passive ammonia data and distributing to NMED, NPS, Southern Ute Tribe, Cherokee Nation, Quapaw Tribe, Four Corners Task Force, EPA R6, Environment Canada, OAQPS and any other interested parties.

6. Ammonia Passive Samplers - Pictures