"Pollution-generating impervious surface" or "PGIS" means those impervious surfaces considered to be a significant source of pollutants in stormwater runoff. Such surfaces include: those which are regularly subject to: vehicular use, industrial activities (as defined in the glossary of the Drainage Manual), or storage of erodible or leachable materials, wastes, or chemicals, and which receive direct rainfall or the run-on or blow-in of rainfall; metal roofs unless they are coated with an inert, non-leachable material such as baked-on enamel coating; or roofs that are subject to venting significant amounts of dusts, mists, or fumes from manufacturing, commercial, or other indoor activities.

The following surfaces are considered regularly-used by motor vehicles: Roads, unvegetated road shoulders, bike lanes within the traveled lane of a roadway, driveways, parking lots, unfenced fire lanes, vehicular equipment storage yards, and airport runways. A surface, whether paved or not, shall be considered subject to vehicular use if it is regularly used by motor vehicles.

The following surfaces are not considered to be regularly-used surfaces by motor vehicles: Paved bicycle pathways separated from and not subject to drainage from roads for motor vehicles, fenced fire lanes, and infrequently used maintenance access roads. (Added by Amended Ord. 10-026, June 9, 2010, Eff date Sept. 30, 2010; Amended by Ord. 15-103, Jan. 11, 2016, Eff date Jan. 22, 2016).