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National Pollutant Discharge Elimination System (NPDES)

Water pollution contaminates surface waters making them unsafe for drinking, fishing, swimming, and other activities. Anybody discharging "pollutants" through a "point source" into a "waters of the United States" must have an NPDES permit.

The NPDES permit contains limits on what you can discharge, monitoring and reporting requirements, and other provisions to ensure that the discharge does not harm water quality or public health. See EPA website for additional information

Two Phases of NPDES Program

Phase I:

Developed in 1990 by the EPA, this phase addresses sources of storm water runoff that have the greatest potential to negatively impact water quality. The EPA requires NPDES permit coverage for storm water discharges from:

Medium and Large Municipal Separate Storm Sewers (MS4) serving populations of 100,000 or more
Eleven categories of industrial activity including construction activities disturbing five or more acres of land

Phase II:

Published in December 1999, this phase revised the "No Exposure Exclusion" for certain industrial facilities under Phase I of the NPDES Storm Water Program and established three potential waivers for small construction activities. Phase II also requires NPDES permit coverage for storm water discharges from:

Regulated Small MS4s which are any MS4s not covered by Phase I and located in "urbanized areas" of a certain population
Construction activity disturbing one to five acres of land

Please review the Overview of the NPDES Storm Water Program for more information

Twin House Road Turnbays - Cottonwood, ID

Page Last Modified: 4/3/2008 9:59:37 AM