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 purpose of the ambient air monitoring network is to sample air pollution in a variety of settings, assess the health and welfare effects, and assist in determining sources of air pollution. In general, six basic monitoring objectives and five measuring scales are used to determine the network design. Since it is physically and fiscally impossible to monitor the air in every location, representative samples must be obtained. These samples are determined by using the monitoring objectives and the spatial measurement scales. The network must be dynamic enough to maintain a current representative sample of the air quality. Air quality issues such as eight-hour ozone non-attainment boundaries and permits for new sources are diverse and controversial subjects for the citizens of Maricopa County. With its robust air monitoring network and mobile monitoring tools, the department strives to provide the most reliable and relevant air monitoring data to the public.

This document is designed to improve compliance with Maricopa County air pollution rules and regulations, with particular emphasis on Rule 310, which deals with fugitive dust sources, a major source of PM-10. It also describes control measures and work strategies that will assist in ensuring compliance with Rule 310. Also included in this report is a glossary of terms, a brief summary of applicable County air pollution regulations, and detailed information on the requirements for implementation of dust control practices.

Letter from Carl Hayden to W. W. Bass informing him that his contribution for maintaining the roads at the Grand Canyon has been reduced to $50 per year. Hayden also notes that no further action on national park status will be taken until December 1917 during the regular session of congress.