BMP Design to Achieve Compliance With NONA Provisions of the New IGP
Compliance with the monitoring and reporting requirements of the recently authorized Industrial General Permit (IGP) will be time consuming and expensive for most industrial facilities. However, certain facilities may be able to opt out of permit coverage by making a claim that the site does not discharge storm water and filing a Notice of Non-Applicability (NONA). NONA filing includes submittal of a No Discharge Technical Report demonstrating that the facility is engineered and constructed to retain all runoff even under historic rainfall conditions or, alternately, that the facility is not hydrologically connected to waters of the United States. This paper concerns BMP design to meet the first criterion, on-site retention of all industrial storm water.
BMPs designed for NONA compliance will generally utilize infiltration, on-site consumption of collected storm water, discharge of storm water to a POTW, or a combination of these strategies. The NONA Technical Report will include results of continuous simulation modeling demonstrating that the BMPs can manage runoff from the highest periods of historical rainfall (as determined from the nearest NOAA rain gauge) without storm water discharging from the site.
Several conceptual designs, including approximate costs, will be presented. Where feasible, infiltration is often the most effective BMP. Infiltration basins are relatively inexpensive, but many sites require relatively expensive subsurface galleries. On-site consumption of collected runoff can be feasible at facilities that consume water in the manufacturing or cooling process. Some sanitary sewer utilities will accept storm water discharged during dry days, although the cost is typically quite high. Both the on-site consumption and POTW discharge options typically require installation of significant storage capacity. These are typically expensive BMP options, but can be economically feasible, especially if combined with infiltration BMPs that manage the majority of facility runoff.
Although BMPs sufficient to meet the NONA provisions of the IGP will tend to be relatively expensive, at many facilities implementing these BMPs will be less costly than IGP compliance. In addition, installing BMPs that make your facility a “No Discharge” facility may also decrease the risk of lawsuit by 3rd party NGOs that sue many industrial facilities alleging violations of the Clean Water Act.