This inventory includes emissions of coarse particulate matter <10 µm in diameter (PM10), fine particulate matter < 2.5 µm (PM2.5), nitrogen oxides, sulfur oxides, and ammonia. Emissions are calculated for both Maricopa County and the PM10 nonattaiment area. Annual totals as well as typical daily emissions are provided for all source categories.

The Pima County Department of Environmental Quality has prepared this document to be submitted to the U.S. Environmental Protection Agency, Region IX. The purpose of the Ambient Air Monitoring Network Plan is to determine if the network is achieving the air monitoring objectives specified in 40 CFR Part 58 Appendix D, which mandate adherence to certain number, type and location requirements of monitoring sites and specific site criteria such as monitoring inlet height. The review should also determine if modifications should be made to the network (e.g. through the termination or relocation of unnecessary stations or addition of new stations). In addition, the review is necessary in order to ensure that the residents of Pima County are provided adequate, representative and useful air quality data, and to provide adequate protection to public health.

The Committee selected the following environmental goal: A goal with the purpose of showing continued progress through 2018 by; 1) improving visibility to move days now in the poor/very poor categories up to the fair category, and 2) moving days classified as fair to the good/excellent categories. A progress
assessment will be conducted every 5 years through 2018. The members concluded that this option provides a clear, long term method to track visibility trends in the Phoenix metropolitan area. Additionally, the Committee reached general agreement that the index should not be used to affect short term actions because other programs, such as the High Pollution Advisory Program, are currently in place.