Description: The federal PM10 designations layer is a polygon coverage showing area designations and their classifications as per 40CFR81.305. There are three designation categories: nonattainment, unclassifiable and attainment areas. Nonattainment areas have various classifications. Each designation and classification area has an associated date field that represents the "effective" date of the action as published in 40CFR81.305. Projection: Teale Albers, NAD83 Udated: 01/11/06
Description: Sacramento Ozone Boundary, based on description in Federal Register. includes all of Sacramento and Yolo counties, the portions of Placer and El Dorado counties outside of the Tahoe Basin, the northeast portion of Solano County, and the portion of Suter County south of a line extending from the norther Yolo County line to the Feather River & along the Feather River to the Placer County line.
Description: 500-foot buffer of of major roadways, defined as freeways or urban roads with traffic volumes pf 100,000 or more vehicles per day or rural roads with 50,000 or more vehicles per day.