Phase I Municipal Stormwater Permit

On August 1, 2012 Ecology reissued, with limited changes, the Phase I municipal stormwater permit, effective September 1, 2012 – July 31, 2013. Ecology also reissued the updated 2013-2018 Phase I permit on August 1, 2012, to become effective on August 1, 2013.

The National Pollutant Discharge Elimination System (NPDES) and State Waste Discharge General Permits cover discharges from municipal separate storm sewer systems (MS4s). The Phase I Municipal Stormwater Permit regulates the discharges from MS4s owned or operated by Clark, King, Pierce and Snohomish Counties; and the cities of Seattle and Tacoma (incorporated cities with a population over 100,000 and unincorporated counties with populations of more than 250,000 according to the 1990 census). The permit also applies to MS4s owned by public entities located in a Phase I city or county; including the Ports of Seattle and Tacoma.

Ecology issued the original Phase I permits in July 1995, reissued the Phase I general permit in 2007, and modified it in 2009 and 2010. Visit the Phase I History Webpage.

2012-2013 Phase I Municipal Stormwater Permit	Redline 2012-2013 Phase I Municipal Stormwater Permit Redlined changes are compared to the 2010 Modification of the 2007-2012 permit.
Appendix 1. Minimum Technical Requirements for New Development and Redevelopment	Appendix 1. Minimum Technical Requirements Not changed compared to the 2010 permit modification
Appendix 2. Total Maximum Daily Load Requirements	Appendix 2. Total Maximum Daily Load Requirements
Appendix 3. Annual Report Form for the Port of Seattle and the Port of Tacoma	Appendix 3. Annual Report Form for the Port of Seattle and the Port of Tacoma
Appendix 4. Annual Report Form for Secondary Permittees	Appendix 4. Annual Report Form for Secondary Permittees
Appendix 5. Notice of Intent	Appendix 5. Notice of Intent Not changed compared to the 2010 permit modification
Appendix 6. Street Waste Disposal	Appendix 6. Street Waste Disposal Not changed compared to the 2010 permit modification
Appendix 7. Determining Construction Site Sediment Damage Potential	Appendix 7. Determining Construction Site Sediment Damage Potential Not changed compared to the 2010 permit modification
Appendix 8. Urban Land Uses and Pollutant Generating Sources	Appendix 8. Urban Land Uses and Pollutant Generating Sources Not changed compared to the 2010 permit modification
Appendix 9. Laboratory Methods	Appendix 9. Laboratory Methods Not changed compared to the 2010 permit modification
Appendix 10. Equivalent Programs for Runoff Controls for New and Redevelopment and Construction Sites	Appendix 10. Equivalent Programs for Runoff Controls for New and Redevelopment and Construction Sites

Fact Sheet for October 2011 Draft Permit (November 2011)
Appendix A: Response to Comments (August 1, 2012)
State Register Public Notice (August 1, 2012)

2013-2018 Phase I Municipal Stormwater Permit Errata for the 2013 – 2018 Phase I Permit Fact Sheet for October 2011 Draft Permit (November 2011)	Redline 2013-2018 Phase I Municipal Stormwater Permit Redlined changes are compared to the 2010 Modification of the 2007-2012 permit
Appendix 1. Minimum Technical Requirements or New Development and Redevelopment	Appendix 1. Minimum Technical Requirements or New Development and Redevelopment
Appendix 2. Total Maximum Daily Load Requirements	Appendix 2. Total Maximum Daily Load Requirements
Appendix 3. Annual Report Questions for the Port of Seattle and the Port of Tacoma	Appendix 3. Annual Report Questions for the Port of Seattle and the Port of Tacoma
Appendix 4. Annual Report Questions for Secondary Permittees	Appendix 4. Annual Report Questions for Secondary Permittees
Appendix 5. Notice of Intent	Appendix 5. Notice of Intent Entirely replaced by 2013-2018 version
Appendix 6. Street Waste Disposal	Appendix 6. Street Waste Disposal
Appendix 7. Determining Construction Site Sediment Damage Potential	Appendix 7. Determining Construction Site Sediment Damage Potential Not changed compared to the 2010 permit modification
Appendix 8. Businesses and Activities that are Potential Sources of Pollutants	Appendix 8. Businesses and Activities that are Potential Sources of Pollutants
Appendix 9. Stormwater Discharge Monitoring	Appendix 9. Stormwater Discharge Monitoring Entirely replaced by 2013-2018 version
Appendix 10. Equivalent Programs for Runoff Controls for New and Redevelopment and Construction Sites	Appendix 10. Equivalent Programs for Runoff Controls for New and Redevelopment and Construction Sites
Appendix 11. Structural Stormwater Controls Project List	Appendix 11. Structural Stormwater Controls Project List New Appendix
Appendix 12. Annual Report Questions for Cities and Counties	Appendix 12. Annual Report Questions for Cities and Counties New Appendix