To protect Ohio's water resources, Ohio EPA issues National Pollutant Discharge Elimination System (NPDES) permits. These permits authorize the discharge of substances at levels that meet water quality standards and establish other conditions related to issues such as combined sewer overflows, pretreatment and sludge disposal. This is an overview of the process for issuing individual NPDES permits. The series of steps for a particular permit may vary somewhat depending on the size, nature, and complexity of the discharge.
The first step in developing an NPDES permit is acquisition of chemical, physical, and biological data from the field and laboratory. Instream chemical data are collected to determine the effect of the discharge on receiving water and sediment quality. Biological data are collected to determine if the discharge is having an impact on the fish and macroinvertebrate organisms that live in the receiving water. Effluent chemical data are also obtained to establish an accurate portrayal of current discharge conditions. Instream chemical data and stream physical data, such as cross section measurements and flow, are necessary for conducting water quality modeling.
As part of developing effluent limits and monitoring requirements, the water quality standards that apply to the receiving water are determined, and federal effluent guidelines are consulted for applicability. Permit conditions are developed based on the applicable regulatory requirements to address issues such as new or expanded discharges, combined sewer overflows, sludge disposal, and industrial pretreatment programs.
Ohio EPA develops Water Quality Permit Support Documents (WQPSD), which incorporate a stream assessment, the wasteload allocation, and the antidegradation review. The WQPSD takes a holistic look at a discharger's impact on a stream, evaluating the total impact of the facility rather than just a pipe-by-pipe analysis.
Information considered in developing the WQPSD may include:
- Information and data from the permit renewal application
- Effluent chemical data
- Instream chemical data
- Instream sediment data
- The SARA toxic release inventory
- Whole effluent toxicity test results
- Intensive biological and chemical water quality survey results
- Ohio EPA Division of Environmental Response and Revitalization chemical spills database
- Ohio Department of Natural Resources fish kill records
- Fish tissue analysis
- Wasteload allocation report
One component of the WQPSD is the wasteload allocation. Using stream modeling techniques, water quality under various design conditions can be projected. These techniques, ranging from a simple mass balance method to a complex water quality model, are used to determine what quality effluent a facility must discharge to maintain instream water quality standards.
Effluent limits and monitoring requirements are determined using the WQPSD, a consideration of federal regulations, state regulations, Division of Surface Water policies and guidance, and application of risk management decisions. A fact sheet is prepared that outlines the decision making process and provides the technical justification for the permit limits, monitoring requirements, and other permit conditions. The fact sheet also serves to inform the public of the procedure for providing information for the Agency to consider prior to issuing a final permit.
A public notice announcing the draft permit is issued to inform the public of the actions being taken by Ohio EPA. During the 30-day review period following issuance of the public notice, the general public, regulated entity, and interested parties may become involved in the permitting process by submitting written comments or requesting a public meeting or hearing.
Once the public notice period has ended, all comments are addressed before issuance of the final NPDES permit. Once a final permit is issued, it may be appealed within 30 days to the Environmental Review Appeals Commission.
Additional details of the individual permit process are presented schematically in the following flow charts: