DEQ Water Division
VA Pollutant Discharge Elimination System Permit Program
PO Box 1105
Richmond, VA 23218
2014 VPDES Industrial Stormwater General Permit Regulation [9 VAC 25-151] (VAR 05), effective 7-1-2014 through 6-30-2019
Grab samples are to be collected from the discharge resulting from a storm event that results in an actual discharge from the site (defined as a "measurable" storm event), providing the interval from the preceding measurable storm event is at least 72 hours. The 72-hour storm interval is waived if the permittee can document that less than a 72-hour interval is representative for local storm events during the season when sampling is being conducted.
Magnitude: results in actual discharge
Interval Between Storms: at least 72 hours