Plume 10 : A visible or measurable discharge of a contaminant from a given point of origin that can be measured according to the Ringelmann scale. See: Ringelmann Chart
California Air Resources Board ARB (California Environmental Protection Agency), glossary of air pollution terms, Sacramento, CA, USA 2013. http://www.arb.ca.gov/html/gloss.htm, (Air Pollut - Amer) {594}