How do NPDES permits protect water?
An NPDES permit will generally specify an acceptable level of a pollutant or pollutant parameter in a discharge (for example, a certain level of bacteria). The permittee may choose which technologies to use to achieve that level. Some permits, however, do contain certain generic ‘best management practices’ (such as installing a screen over the pipe to keep debris out of the waterway). NPDES permits make sure that a state’s mandatory standards for clean water and the federal minimums are being met.