Water Quality Division
PO Box 1677
Oklahoma City, OK 73101-1677
Oklahoma Department of Environmental Quality Water Quality Division General Permit )KR05 for Storm Water Discharges from Industrial Facilities Under the Multi-Sector Industrial General Permit Within the State of Oklahoma
1. When and How to Sample. All required monitoring must be performed on a storm event that results in an actual discharge from your site (at least 0.1 inch of storm water event defined as a “measurable storm event”) that follows the preceding measurable storm event by at least 72 hours (3 days). The 72 hours (3 days) storm interval does not apply if you are able to document that less than a 72-hour (3 days) interval is representative for local storm events during the sampling period. In the case of snowmelt, the monitoring must be performed at a time when a measurable discharge occurs at your facility.
Magnitude: at least 0.1 inch
Interval Between Storms: at least 72 hours