General Discharge Permit

General Permit For Discharges of Stormwater Associated With Industrial Activity
Maryland General Permit No. 12-SW 

Important Announcement

The Department is proposing to modify the restoration requirements of the General Permit for Discharges of Stormwater Associated with Industrial Activities (Maryland General Permit No. 12-SW).  The Department held a public hearing concerning the tentative determination on Tuesday, July 24, 2018 at 1 p.m. in the Terra Conference Room at the Maryland Department of the Environment, 1800 Washington Blvd., Baltimore, MD 21230.  

Persons who wish to present infor​mation regarding the tentative determination may still submit written comments to the Department no later than 5:00 p.m. on Wednesday, September 19, 2018 (Note: This comment period has been extended after a request that was made pursuant to Section 1-606(d) of the Environment Article of the Maryland Annotated Code.)  All comments will be considered in making a final determination.

The documents from the hearing and copies of the public notice, draft modification, and fact sheet are available for view by clicking the links below:
Any questions or comments regarding this modification should be directed to Michael Richardson using the following contact information:
  • ​Mail:  Maryland Department of the Environment                                                                                                 Water and Science Administration                                                                                                             1800 Washington Blvd., Suite 455                                                                                                             Baltimore, MD 21230-1708
  • ​E-mail:
  • Phone:  (410) 537-3323 (between 8 a.m. and 5 p.m., Monday through Friday) 

Existing Permit (before pending modification)


Guidance Documents

Supplemental Information

Contact Info

For more information on this permit, contact the Industrial and General Permits Division at (410) 537-3323.

Additional Information and Related Links