Virginia Administrative Code
Title 9 - ENVIRONMENT
Agency 5 - STATE AIR POLLUTION CONTROL BOARD
Chapter 40 - EXISTING STATIONARY SOURCES
Part II - Emission Standards
Article 1 - Visible Emissions and Fugitive Dust/Emissions (Rule 4-1)
Section 9VAC5-40-70 - Definitions

A. For the purpose of these regulations and subsequent amendments or any orders issued by the board, the words and terms shall have the meanings given them in subsection C of this section.

B. As used in this article, all terms not defined here shall have the meanings given them in 9VAC5 Chapter 10 (9VAC5-10-10 et seq.), unless otherwise required by context.

C. Terms defined.

"Fugitive dust" means particulate matter composed of soil or other materials, or both, of natural origin. Fugitive dust may include emissions from haul roads, wind erosion of exposed surfaces and storage piles and other activities in which the material is either removed, stored, transported or redistributed.

"Fugitive emissions" means emissions which are generated by industrial or other activities and which do not pass through a stack, chimney, vent or other functionally equivalent opening, but which may escape from openings (such as windows, doors, ill-fitting closures or poorly maintained equipment) or material handling equipment.

"Opacity" means the degree to which emissions reduce the transmission of light and obscure the view of an object in the background, expressed as a percentage.

"Six-minute period" means any one of the 10 equal parts of one hour or a one-hour period, as may be applicable.