Selenium Discharge Permit

I recently have been involved in several projects that deal with the difficulties associated with meeting Selenium Discharge Permits.  Selenium is expensive to remove and difficult to test for accurately at the ppb level seen on some permits.  Protecting the environment from pollution is a noble cause.  Requiring end users to reduce selenium to levels lower then the incoming water content is absurd.  It is this type of requirement that forces manufacturing to choose between losing profit or  relocating manufacturing overseas.