The current deluge of heavy rain along the Ohio River has yielded 24-hour rain totals equivalent to average monthly totals.  Industries with outdoor areas exposed to stormwater may want to review the Stormwater Pollution Prevention Plan (SWPPP) or Best Management Practices (BMP) Plan to see if the heavy rains have triggered specific action items under their KPDES requirements. There are specific requirements for inspections following significant rain events as described in the current Kentucky general discharge permit for stormwater associated with industrial activities (KYR000000). The 2-yr, 24-hour rain event is the trigger for conducting the compliance inspections to verify installed controls and best management practices are functional and sufficient for control and management of stormwater runoff. For most of Kentucky, the 2-yr/24-hour event is a rainfall between 3.0 and 3.5 inches in a 24-hour period. It is important to note that these inspections following 2-yr, 24-hr events are required in addition to regularly scheduled inspections to be conducted quarterly (at a minimum) and an annual inspection. A list of the required information for documenting inspections can be found on Page 13 of the KYR000000 general permit.

Also, the reasoning for inclusion of inspections can be found in the Fact Sheet for KYR000000:

“A necessary component of any SWPPP to ensure its effectiveness is the inspections conducted by the operator. Periodic routine inspections, inspections after significant precipitation events, and an annual site assessment as part of the SWPPP review are essential in achieving and maintaining compliance with the conditions of the permit. These inspections alert the operator to actual and potential deficiencies in the SWPPP, control measures and BMPs that have or may result in substandard discharges thus initiating appropriate actions by the operator. As a necessary component of the SWPPP the requirement to conduct such inspections are authorized by 401 KAR 5:065, Section 2(4) [40 CFR 122.44(k), July 1 2008].”