Maryland Department of the Environment

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General Discharge Permit

​General Permit For Discharges from Stormwater Associated with Industrial Activities
Maryland General Permit No. 20-SW

NOTICE - Permit Modification Issued (effective February 7, 2025)​​​​

The Department's original Final Determination for the 20-SW (effective February 1, 2023) was challenged in the Circuit Court for Baltimore County.  As a result, the Department agreed to a limited remand of the permit to receive comments. Those comments have been reviewed and we are addressing them via a new final determination and modified permit. The modified permit, now the 20-SW-A, has been issued effective Friday, February 7, 2025.​​​

​Permit Training​​​​
The Department offers free training opportunities for several of its general permits.  Visit the WPPRP Training Website to sign up for an upcoming training event or to download information from past training events.  

20-SW Permit Information​

​Permit​

Forms

Guidance Documents

Supplemental Information​

The following documents include comments received on the 20SW and the 20SW remand, and the Department’s decision.​

Contact Info

If you have additional questions or would like more information, please contact the Industrial Stormwater Permits Division at (410) 537-3323.


Previous Permits​


Additional Information and Related L​inks


Maryland Department of the Environment
1800 Washington Blvd
Baltimore, MD 21230