Regulatory methods used in writing NPDES permits for the shipbuilding and repair industry

The Shipbuilding and Repair Industry lacks national effluent standards, and National Pollutant Discharge Elimination System (NPDES) permits for shipya rds are developed differently in each state depending upon federal or state legal requirements and site-specific environmental conditions. Because the extent of variation in regulatory and NPDES permit requirements was not kn own, a survey was conducted to determine how state regulatory agencies and EPA regional offices establish NPDES numerical limits and monitoring requir ements for this industry. States and EPA regions bordering major water bodi es were contacted, and 23 federal and state regulatory agencies responded. The survey asked how NPDES permit conditions are established for industry i n general, and specifically for the shipbuilding and repair industry. The s urvey also asked how an ecological risk assessment could be applied to the development of a shipyard NPDES permit, and evaluated future regulatory tre nds. Survey results revealed that the regulatory methods used to develop NP DES permit conditions for shipyards or industry in general do not vary grea tly. However, the use of biological monitoring (e.g., biosurveys, tissue an alyses, and whole effluent toxicity (WET) tests) is applied less frequently to shipyards, while the use of mixing zones for determining chemical-speci fic numerical limits is applied considerably more often to industry in gene ral.