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 shipyards 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 known, a survey was conducted to determine how state regulatory agencies and EPA regional offices establish NPDES numerical limits and monitoring requirements for this industry. States and EPA regions bordering major water bodies were contacted, and 23 federal and state regulatory agencies responded. The survey asked how NPDES permit conditions are established for industry in general, and specifically for the shipbuilding and repair industry. The survey also asked how an ecological risk assessment could be applied to the development of a shipyard NPDES permit, and evaluated future regulatory trends. Survey results revealed that the regulatory methods used to develop NPDES permit conditions for shipyards or industry in general do not vary greatly. However, the use of biological monitoring (e.g., biosurveys, tissue analyses, and whole effluent toxicity (WET) tests) is applied less frequently to shipyards, while the use of mixing zones for determining chemical-specific numerical limits is applied considerably more often to industry in general.