# Commonwealth of Puerto Rico

**URL:** https://aqualisco.com/compliance_item/commonwealth-of-puerto-rico/
**Author:** Carlie Utesch
**Published:** May 2, 2023

> Last Updated 08/07/2026 Puerto Rico NPDES Permit EPA’s 1999 stormwater Phase II regulations established small municipal separate storm sewer systems (MS4s) in urbanized areas, as well as small MS4s outside the urbanized areas that are designated by the permitting authority,...

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Last Updated 08/07/2026

								
				
				
				
					
## Puerto Rico NPDES Permit
				
				
				
		
		
				
				
									EPA’s 1999 stormwater Phase II regulations established small municipal separate storm sewer systems (MS4s) in urbanized areas, as well as small MS4s outside the urbanized areas that are designated by the permitting authority, to obtain NPDES permit coverage for their stormwater discharges.

Region 2 issued the first Small MS4 General Permit (Small MS4 GP) for those public entities in 2006 for the Commonwealth of Puerto Rico. The current Small MS4 GP and Small MS4 GP Fact Sheet went into effect on July 1, 2016.

The issued general permit requires MS4s to continue implementing and updating their existing Stormwater Management Program. EPA developed a Storm Water Management Program template that is designed to assist MS4s in selecting and incorporating section(s) that provide guidance with the six minimum control measures of the Small MS4 GP. There is a Stormwater Management Program (English Version) and a Stormwater Management Program (Spanish Version).

								
				
				
				
				
									
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### Resources
				
				
				
				
							
			
						
		
						
				
				
		
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### NPDES Small MS4 General Permit and Fact Sheet

				
				
		
				
				
									View Ordinances

								
				
				
				
							
			
						
		
						
				
				
				](https://www.epa.gov/npdes-permits/npdes-permits-phase-2-stormwater-program-puerto-rico)
				
					
				
		
					
				
				
									The information on this page is provided for general informational purposes only and is not legal advice. Regulations change frequently — AQUALIS makes no warranty as to the accuracy or completeness of this content, and any reliance on it is at your own risk. Consult a qualified professional or your local regulatory authority to confirm requirements applicable to your specific property.