The Ohio Environmental Protection Agency (Ohio EPA) has issued its final National Pollutant Discharge Elimination System Industrial Storm Water General Renewal Permit. This permit is significantly different than Ohio EPA’s previous industrial storm water general permit, which included broad, non-facility specific, permit requirements. This final renewal permit now mirrors U.S. EPA’s Multi-Sector Industrial Storm Water General Permit and establishes industry-specific requirements for managing and monitoring storm water discharges.
The Ohio EPA permit becomes effective January 1, 2012. Facilities do not have to do anything yet. Ohio EPA will send written instructions to existing covered facilities on how to continue their general permit coverage with the submittal of a “re-notification” of intent to be covered. The existing facility will have 90 days to submit the re-notification.
The new permit provides coverage for the typical five years under an NPDES permit, but now includes benchmark monitoring concentration values for specific industrial sectors, that if exceeded after four years of monitoring, will require a review of control measures and certain evaluations. The permit states that the benchmark concentration values are not effluent limits, as they are to be considered a value that the permittee may compare with monitoring results to gauge effectiveness of their Best Management Practices and Control Measures.
During the first three years of the permit, monitoring and reporting is only required for four out of the 12 quarters (with at least one sampling required from each quarter period). In the fourth year, the data is averaged and compared to the applicable benchmark concentration value. If there is an exeedance of the benchmark value, then a thorough review of existing BMPs and control measures is triggered to determine why they were not effective in meeting the benchmark value and if any adjustments are needed.
The permit allows the benchmark value concentrations to be modified for an individual facility after three years of monitoring if reasonable justification is provided to Ohio EPA. In addition, in the review of monitoring data, the facility may take into consideration exceedances of benchmark values caused by natural background pollutants. Also, there is a procedure under the permit that allows a facility to make a determination that “no further pollutant reductions are technologically available and economically practicable and achievable in light of best industry practice to meet the control measures/best management practices (BMPs) in Part 2 of this Permit.” The rationale for this determination must be documented and retained with the Storm Water Pollution Prevention Plan (SWPPP), and provide notification of this determination to Ohio EPA at the due date for the next benchmark monitoring report. It appears that the actual documentation does not need to be submitted to Ohio EPA unless Ohio EPA requests it.