3.6
The thresholds triggering specific minimum requirements for runoff treatment are based on the total amount of the project’s new plus replaced PGHS and PGPS, as these areas are considered a significant source of pollutants in stormwater runoff. PGHS examples include areas subject to vehicular use (including permeable pavement); certain industrial activities; and outdoor storage of erodible or leachable materials, wastes, or chemicals. Metal roofs are also considered to be PGHS unless they are coated with an inert, non-leachable material (e.g., baked-on enamel coating). Examples of PGPS include lawns and landscaping areas subject to the use of fertilizers and pesticides. Refer to Appendix A for detailed definitions of these key terms.
New plus replaced PGHS and PGPS shall be quantified separately for work within and outside the right of way.