Pima County Department of Environmental Quality monitors ambient (outdoor) air pollutants throughout eastern Pima County, including the Tucson metropolitan area and Green Valley. There are six principal pollutants, called “criteria” pollutants that are monitored in accordance with the National Ambient Air Quality Standards set by the Environmental Protection Agency to comply with the Federal Clean Air Act. These standards were established to protect public health and the environment from harmful levels of air pollution.

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.

Takes a comprehensive view of ironwood habitats in both the United States and Mexico, evaluating the ecological and cultural resources supported by the ancient ironwood tree. The study provides an overview of the history and ecology of desert ironwood, and a discussion of the binational research effort undertaken to produce the report.

In February of 1998, the Pima County Board of Supervisors launched what has evolved into the Sonoran Desert Conservation Plan (SDCP) -- a comprehensive effort to protect the Sonoran Desert, guide growth and rationalize land development in the metropolitan Tucson region. Proponents of this planning process maintained that the project would reconcile conflicts between human activities and conservation, providing benefits for both wildlife and economic development. Critics, however, have increasingly alleged that implementing such an initiative will adversely affect land and housing markets, increase taxes and create problems of housing affordability. Over time a pressing need has consequently grown for objective information about the possible fiscal and economic impacts of the conservation programs being assembled by Pima County. This report addresses that need. It is a tool in the form of an impartial framework for assessment that government officials, environmentalists, business people and the general public can use for debate and decision-making.