Small Municipal Separate Storm Sewer Systems (MS4s) - General Permit

Final Small Municipal Separate Storm Sewer Systems (MS4s) Permit Renewal


On September 11, 2014, Ohio EPA finalized the renewal of the small MS4 general permit, see below for more information.

Issue Date: September 11, 2014
Effective Date: September 11, 2014
Expiration Date: September 10, 2019

The NPDES Small MS4 general permit renewal will afford coverage to regulated Small MS4s, be applicable statewide, and have a duration of 5 years.  This is the third generation of this general permit. The renewal requires a regulated Small MS4 operator’s construction and post-construction requirements, at a minimum, be equivalent with the technical requirements set forth in the current, at time of issuance of this permit, Ohio EPA NPDES General Storm Water Permit for Construction Activities (CGP) applicable for the MS4 operator’s area. This includes the following Ohio EPA NPDES General Storm Water Permits for Construction Activities:

This approach will deter conflicting requirements and allow for a lessened presence of Ohio EPA in regards to the CGP requirements within MS4 jurisdictions. Under this approach, regulated MS4s located within the Big Darby Creek Watershed and portions of the Olentangy River Watershed will need to have their local regulations be, at a minimum, equivalent with the technical requirements set forth in these two Ohio EPA alternative NPDES CGPs. All other regulated MS4s would be required to have their local regulations be, at a minimum, equivalent with the technical requirements set forth in the Ohio EPA statewide NPDES CGP. 

For additional information and permit compliance materials, please see our MS4 Program tab.


Draft Small Municipal Separate Storm Sewer Systems (MS4s) - General Permit

On November 27, 2013, Ohio EPA released a draft small MS4 general permit renewal for review and comment.  Please see the following public notice for more information.  The deadline for comments is January 29, 2014.


Expired Small Municipal Separate Storm Sewer Systems (MS4) Permit 

Issue Date: January 30, 2009
Effective Date: January 30, 2009
Expiration Date: January 29, 2014


For additional information contact:

Anthony Robinson
DSW Storm Water Section
(614) 728-3392