Who is regulated under the Storm Water Phase II Final Rule?
The rule automatically regulates two classes of storm water dischargers on a nationwide basis: Operators of small MS4s located in “urbanized areas” as defined by the Bureau of Census and operators of construction activities that disturb equal to or greater than 1 and less than 5 acres of land. Additional small MS4s (outside urbanized areas) and construction sites (disturbing less than one acre of land), along with other sources which are a significant contributor of pollutants to waters of the U.S., may be brought into the NPDES Storm Water Program by the NPDES permitting authority. The rule also exclude from the NPDES program storm water discharges from industrial facilities that have “no exposure” of industrial activities or materials to storm water. This exclusion does require facilities to complete, sign, and submit a no exposure certification to the permitting authority once every five years. When will I need to get a permit under the Storm Water Phase II regulations? Operators of
