Maryland’s NPDES Municipal Separate Storm Sewer System (MS4) Permits

    The Environmental Protection Agency’s (EPA) National Pollutant Discharge Elimination System (NPDES) stormwater regulations were published in 1990. Phase I of these regulations require large urban jurisdictions to control pollution in stormwater to the maximum extent practicable (MEP). For permitting purposes,municipalities with populations of greater than 250,000 are considered “large” and those with populations of between 100,000 and 250,000 as “medium.” Municipalities with less than 100,000 are handled separately under Phase II NPDES stormwater rules discussed here ( click here to learn more about Phase II ). After receiving applications from Phase I municipalities in 1991 and 1992, MDE began issuing NPDES municipal stormwater permits in 1993. These permits are updated every five years. The following provides information on the most current activities on the Phase I permits.

Notice of Tentative Determination
to Modify a Stormwater Permit to Baltimore County
(August 31, 2018)

The Maryland Department of the Environment (MDE) has reached a tentative determination to modify the National Pollutant Discharge Elimination System (NPDES) Municipal Separate Storm Sewer (MS4) permit issued to Baltimore County to control storm drain system pollutant discharges. MDE has drafted permit modifications designed to comply with the United States Environmental Protection Agency’s (EPA) regulations, control stormwater pollutant discharges from the County’s storm drain system, and allow Baltimore County to use Maryland’s newly authorized nutrient trading program as an option to meet its 20 percent impervious surface restoration requirement.

The EPA regulations (40 CFR Part122.62) and current permit conditions (see PartVII.E.1, Permit Revocation and Modification) allow for NPDES permits to be modified for an appropriate cause. Baltimore County officially requested a modification of its current permit (Discharge Permit Number 11-DP-3317 MD0068314) on July 18, 2018 to allow the use of nutrient trading to meet the 20 percent impervious surface restoration requirement by the end of the current permit term (i.e., December 23, 2018). MDE has determined the use of nutrient credits by the County for meeting the 20 percent impervious surface restoration requirement is acceptable. Therefore, MDE hereby proposes to add a new paragraph that allows for nutrient trading to meet this requirement in PART IV.E.3; and to rename the original permit’s PART IV.E.3 and PART IV.E.4 as PART IV.E.4 and PART IV.E.5, respectively. The proposed permit modifications and fact sheet are located here:
Copies of these documents may be procured at a cost of $0.36 per page. MDE will hold a public hearing concerning the tentative determination to modify Baltimore County’s MS4 permit on Thursday, October 11, 2018 at 5 PM, MDE first floor, 1800 Washington Boulevard, Baltimore, Maryland, 21230. Comments on this tentative determination to modify Baltimore County’s MS4 permit will be accepted by Raymond Bahr, Maryland Department of the Environment, Water and Science Administration, 1800 Washington Boulevard, Baltimore, Maryland, 21230, or raymond.bahr@maryland.gov, if received within 90 days of publication of this notice. The 60-day extension of the comment period allowed for by section 1-606 (d) (1) (ii) of the Maryland Environmental Article is being invoked to extend the usual 30-day comment period to 90 days.

 

Notice of Tentative Determination
to Modify a Stormwater Permit to Anne Arundel County
(August 31, 2018)

The Maryland Department of the Environment (MDE) has reached a tentative determination to modify the National Pollutant Discharge Elimination System (NPDES) Municipal Separate Storm Sewer (MS4) permit issued to Anne Arundel County to control storm drain system pollutant discharges.  MDE has drafted permit modifications designed to comply with the United States Environmental Protection Agency’s (EPA) regulations, control stormwater pollutant discharges from the County’s storm drain system, and allow Anne Arundel County to use Maryland’s newly authorized nutrient trading program as an option to meet its 20 percent impervious surface restoration requirement.
The EPA regulations (40 CFR Part122.62) and current permit conditions (see PartVII.E.1, Permit Revocation and Modification) allow for NPDES permits to be modified for an appropriate cause.  Anne Arundel County officially requested a modification of its current permit (Discharge Permit Number 11-DP-3316 MD0068306) on August 10, 2018 to allow the use of nutrient trading to meet the 20 percent impervious surface restoration requirement by the end of the current permit term (i.e., February 11, 2019).  MDE has determined the use of nutrient credits by the County for meeting the 20 percent impervious surface restoration requirement is acceptable.  Therefore, MDE hereby proposes to add a new paragraph that allows for nutrient trading to meet this requirement in PART IV.E.3; and to rename the original permit’s PART IV.E.3 and PART IV.E.4 as PART IV.E.4 and PART IV.E.5, respectively.  The proposed permit modifications and fact sheet are located here:

Copies of these documents may be procured at a cost of $0.36 per page.  MDE will hold a public hearing concerning the tentative determination to modify Anne Arundel County’s MS4 permit on Thursday, October 18, 2018 at 5 PM, MDE first floor, 1800 Washington Boulevard, Baltimore, Maryland, 21230. Comments on this tentative determination to modify Anne Arundel County’s MS4 permit will be accepted by Raymond Bahr, Maryland Department of the Environment, Water and Science Administration, 1800 Washington Boulevard, Baltimore, Maryland, 21230, or raymond.bahr@maryland.gov, if received within 90 days of publication of this notice. The 60-day extension of the comment period allowed for by section 1-606 (d) (1) (ii) of the Maryland Environmental Article is being invoked to extend the usual 30-day comment period to 90 days. 

 

Notice of Tentative Determination
to Modify a Stormwater Permit to Prince George's County
(September 14, 2018)

The Maryland Department of the Environment (MDE) has reached a tentative determination to modify the National Pollutant Discharge Elimination System (NPDES) Municipal Separate Storm Sewer (MS4) permit issued to Prince George's County to control storm drain system pollutant discharges.  MDE has drafted permit modifications designed to comply with the United States Environmental Protection Agency’s (EPA) regulations, control stormwater pollutant discharges from the County’s storm drain system, and allow Prince George's County to use Maryland’s newly authorized nutrient trading program as an option to meet its 20 percent impervious surface restoration requirement.
The EPA regulations (40 CFR Part122.62) and current permit conditions (see PartVII.E.1, Permit Revocation and Modification) allow for NPDES permits to be modified for an appropriate cause.  Prince George's County officially requested a modification of its current permit (Discharge Permit Number 11-DP-3314 MD0068284) on August 31, 2018 to allow the use of nutrient trading to meet the 20 percent impervious surface restoration requirement by the end of the current permit term (i.e., January 1, 2019).  MDE has determined the use of nutrient credits by the County for meeting the 20 percent impervious surface restoration requirement is acceptable.  Therefore, MDE hereby proposes to add a new paragraph that allows for nutrient trading to meet this requirement in PART IV.E.3; and to rename the original permit’s PART IV.E.3 and PART IV.E.4 as PART IV.E.4 and PART IV.E.5, respectively.  The proposed permit modifications and fact sheet are located here:
Copies of these documents may be procured at a cost of $0.36 per page.  MDE will hold a public hearing concerning the tentative determination to modify Prince George's County’s MS4 permit on Thursday, October 25, 2018 at 5 PM, MDE first floor, 1800 Washington Boulevard, Baltimore, Maryland, 21230. Comments on this tentative determination to modify Prince George's MS4 permit will be accepted by Raymond Bahr, Maryland Department of the Environment, Water and Science Administration, 1800 Washington Boulevard, Baltimore, Maryland, 21230, or raymond.bahr@maryland.gov, if received within 90 days of publication of this notice. The 60-day extension of the comment period allowed for by section 1-606 (d) (1) (ii) of the Maryland Environmental Article is being invoked to extend the usual 30-day comment period to 90 days. 

 

Consent Decree


The Maryland Department of the Environment and the Montgomery County Department of Environmental Protection have reached tentative agreement on a consent decree to be filed in Montgomery County Circuit Court resolving issues with the county’s performance pursuant to the National Pollutant Discharge Elimination System (NPDES) Municipal Separate Storm Sewer System (MS4) permit issued February 15, 2010. The five-year permit expired in 2015.

  


Contact Info

Questions about NPDES municipal permits may be directed to the Sediment, Stormwater, and Dam Safety Program at 410-537-3543 or emailed to Mr. Raymond Bahr at Raymond.Bahr@maryland.gov. ​​​